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Medical Research Archives

Knowledge Enterprise Journals

Preprints posted in the last 7 days, ranked by how well they match Medical Research Archives's content profile, based on 11 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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Validity and Reliability of the Novel Indonesian Instrument for Aphasia Diagnosis (IDEA)

Prawiroharjo, P.; Fakhri, A.; Gabrielle, A.; Martalia, V.; Rahmayani, S. A.; Wijaya, V. G.

2026-07-19 neurology 10.64898/2026.07.17.26358303 medRxiv
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Aphasia diagnosis in Indonesia remains challenging due to limited culturally and linguistically appropriate instruments. Widely used tools such as the Boston Diagnostic Aphasia Examination (BDAE) and Western Aphasia Battery (WAB) are not adapted to the Indonesian context, while Tes Afasia untuk Diagnosis, Informasi, dan Rehabilitasi (TADIR) provides screening but lacks diagnostic accuracy. To address this gap, we developed the Instrumen Diagnosis dan Evaluasi Afasia (IDEA) for native Indonesian speakers and evaluated its validity, reliability, and normative cutoff values in cognitively healthy Indonesian adults. Eighty-three cognitively normal adults (screened using MoCA-Ina) with no history of neurological disease were assessed using IDEA, which evaluates six language domains. Items were adapted from existing tools and reviewed by experts. Content validity, internal consistency (Cronbachs alpha), and construct validity (Exploratory Factor Analysis) were analyzed using SPSS v25. A total of 83 participants were included (median age = 55.81 years, 54% secondary education). IDEA demonstrated good feasibility, with an average completion time of 45-60 minutes depending on participant engagement. Content validity was established by unanimous expert consensus. Construct validity showed meritorious sampling adequacy (KMO = .872) and significant sphericity (Bartletts test {chi}^2 (15) = 278.523, p<.001), supporting factor analysis. Internal consistency showed good reliability across six domains (Cronbachs = 0.896). IDEA is a valid and reliable tool for assessing aphasia in Indonesian natives. It is a culturally appropriate assessment tool which offers structured, domain-based evaluation and supports differential diagnosis of both classical and progressive aphasia syndromes. Keywords: Aphasia, Language Assessment, Indonesian, IDEA, Validity

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Modified Ghost System combining action, observation, and vibration stimulation for recovery after distal radius fracture surgery: A single-arm clinical feasibility study protocol

Kano, A.; Akiyama, Y.; Kamijo, Y.-I.; Hamaguchi, T.

2026-07-18 rehabilitation medicine and physical therapy 10.64898/2026.07.16.26358289 medRxiv
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Distal radius fractures (DRFs) can delay return to activities of daily living and social participation because of postoperative pain, temporary joint immobilization, and limited wrist and forearm range of motion. The Ghost System developed at Saitama Prefectural University, Japan, combines visual action observation with tendon vibration stimulation and has shown potential as an adjunct to conventional rehabilitation. This Study Protocol describes a modified Ghost system intended to improve clinical implementation by replacing the head-mounted virtual reality display with iPad-based action observation and by using a wristband-type vibrator. This single-center, single-arm, open-label feasibility trial will enroll 10 adults after palmar locking plate fixation for DRF. The intervention will be delivered twice weekly during outpatient rehabilitation follow-up sessions from the early postoperative period (postoperative days 2-10 after enrollment) through the approved early postoperative rehabilitation period (generally up to postoperative week 8), in parallel with standard rehabilitation practices. Primary feasibility and preliminary clinical outcomes include device fit and acceptability, pain assessed using a 100-mm Visual Analog Scale, and wrist/forearm range of motion. Secondary implementation and safety outcomes include Disabilities of the Arm, Shoulder and Hand (DASH), Patient-Rated Wrist Evaluation (PRWE), Hand20 Questionnaire (HANDS-20), EuroQol 5 Dimensions 5 Levels (EQ-5D-5L), body ownership and hand-illusion questionnaires, setup time, setup errors, adherence, adverse events, and device incidents. We hypothesize that the modified Ghost system will be feasible and acceptable for early postoperative outpatient rehabilitation and will be delivered without serious device-related adverse events. Clinical outcomes will be summarized descriptively to inform a future controlled study rather than to establish efficacy.

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Safety Transparency in Animal Cell-Cultured Ingredients for Pet Food: A Case Study Establishing the Standard for Public Disclosure

Tewari, R.; Soukup, R.; Hadjistylianou, L.; Manicone, M.; Serra, M.; Felbermair, M.; Falconer, S.

2026-07-15 cell biology 10.64898/2026.07.14.738473 medRxiv
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Animal cell-cultured ingredients are entering the EU and UK pet food markets under frameworks that do not require pre-market, ingredient-level safety assessments, creating an ethical need for transparent safety disclosure. We present the first public safety dossier for this sector, describing the proprietary mouse embryonic stem cell line PE25 and its derived, non-viable cellular and conditioned media ingredient produced in food and feed-grade media. PE25 characterization confirmed Mus musculus identity, sterility, absence of mycoplasma and replication-competent retroviruses, and stable growth. Doxorubicin-induced p53 stress testing, CD44/BMI1 profiling, and soft agar assays showed no cancer-like traits and a non-tumorigenic profile; the final ingredient contains no viable cells. Independent OECD TG 471 and 487 assays confirmed non-genotoxicity. Heavy metals, biogenic amines, solvents, and chemical residues were below regulatory limits. Given process variability, we recommend case-by-case safety evaluation and propose this dossier as a model for responsible commercialization.

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Malaria Pre-screening Technology Using Artificial Intelligence (AI)

Ibeto, O. O.; Nwoye, E. O.

2026-07-17 infectious diseases 10.64898/2026.07.15.26357432 medRxiv
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Malaria remains a severe health problem in endemic regions because people lack adequate diagnostic tools, leading to delayed medical care and elevated death rates. This research introduces a dual-mode artificial intelligence system that uses two complementary models to enhance malaria pre-screening and diagnosis. The patient-centered model uses multivariate logistic regression to analyze biosignals, including heart rate, body temperature, and oxygen saturation, collected through a wearable sensor prototype and a mobile interface for symptom analysis. The system enables patients to begin self-assessment to determine their level of need before scheduling a doctor's appointment. The clinician-centered model represents a customized convolutional neural network that uses annotated microscopy images of red blood cells to achieve 94.84% accuracy, 95.71% precision, 93.87% recall, 94.78% F1 score, and 0.84 Area Under Curve (AUC). The patient model achieved 94.6% accuracy and an AUC of 0.985 using a 70/30 train-test split. These systems work together to create a layered diagnostic system that can operate independently or together to detect malaria at an early stage, especially in areas with limited resources. The findings demonstrate that wearable biosignal data integration with image-based deep learning can produce dependable, scalable, and user-friendly systems for malaria pre-screening. Keywords - malaria diagnosis, artificial intelligence (AI), convolutional neural networks (CNN), wearable biosensors, multivariate logistic regression

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Povidone-iodine ear wash and oral cotrimoxazole for chronic suppurative otitis media in Australian Aboriginal children: a randomised controlled 2x2 factorial design trial

Beissbarth, J.; Wigger, C.; Oguoma, V. M.; Leach, A. J.; Lennox, R.; Nelson, S.; Patel, H.; Chatfield, M. D.; Currie, K.; Coates, H.; Edwards, K.; Smith-Vaughan, H. C.; Hare, K. M.; Torzillo, P. J.; Tong, S. Y. C.; Morris, P. S.

2026-07-21 infectious diseases 10.64898/2026.07.20.26358454 medRxiv
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Objectives: To compare the effectiveness of povidone-iodine ear wash compared to no ear wash and oral cotrimoxazole compared to placebo given in addition to standard topical antibiotic treatment (ciprofloxacin drops) for chronic suppurative otitis media (CSOM) in Australian Aboriginal children. Methods: A randomised, parallel, 2 x 2 factorial design, assessor-blinded clinical trial in the remote Northern Territory of Australia. Aboriginal children with confirmed CSOM were eligible to be randomised into four treatment groups, allowing two primary treatment comparisons in a 2-in-1 trial approach. Participants received standard treatment (twice daily cleaning and topical ciprofloxacin drops) plus: i) either 16 weeks of pre-treatment povidone-iodine ear wash or no povidone-iodine ear wash; and ii) either 16 weeks of oral cotrimoxazole or placebo. Central randomisation with allocation concealment and triple-blinding of the oral antibiotic treatment arms was used. The relative risk (RR) and risk difference (RD) were estimated after adjustment for age, community, and the other intervention. The primary outcome was the proportion of children with any otorrhoea (clinical failure) after 16 weeks of treatment. Secondary outcomes included size of tympanic membrane (TM) perforation and amount of discharge, time to cessation of discharge, proportion of children with respiratory and other pathogens in ear discharge (at baseline and 16 weeks) and hearing levels (at 12 months). Findings: 280 children with CSOM were randomised and 270 had their primary outcome assessed. Clinical failure (presence of any ear discharge) after 16 weeks of treatment was 66/134 (49%) in the povidone-iodine group versus 69/136 (51%) in the no povidone-iodine group (RD= -1% (-12,11), p= 0.93) and 56/134 (42%) in the cotrimoxazole group versus 79/136 (58%) in the placebo group (RD=-16% (-28,-4), p=0.007). The amount of discharge, TM perforation size, the level of hearing impairment, and serious adverse events were not significantly different in both treatment comparisons. Anaerobic growth (24%), Pseudomonas aeruginosa (21%) and Haemophilus influenzae (17%) were the most common pathogens found in the ear discharge before treatment. Fungi or yeast (24%), Staphylococcus aureus (15%), and anaerobic growth (10%) were the common pathogens after 16 weeks of treatment, with no significant differences between groups. At 12 months post-randomisation, 55-60% of children had at least one discharging ear and there was no difference between treatment groups. Interpretation: Povidone-iodine ear washes did not contribute to better ear outcomes in this study. Cotrimoxazole for 16 weeks resulted in more children with clinical improvement to dry ears. Oral cotrimoxazole may play a role in reducing the burden of CSOM in populations with high rates of persistent disease.

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Molecular dynamics simulations demonstrate reduced antibiotic affinity to mirror bacterial targets

Fady, P.-E.; Ciccone, J.

2026-07-15 molecular biology 10.64898/2026.07.14.738450 medRxiv
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"Mirror life", self-replicating organisms composed of non-natural-chirality biomacromolecules, presents a future threat with potentially global consequences. Consequently, there is strong agreement among experts that it should not be created. However, there is some disagreement over how effective existing medical countermeasures might prove against mirror bacteria in the event that they were created. Here, we leverage computational chemistry methods including docking and molecular dynamics to determine the likely binding efficacy of existing antibiotics against natural and mirror bacterial protein targets. We find that most existing antibiotics fail to bind to mirror bacterial protein targets, unlike their natural-chirality targets. This suggests altered binding of current medical countermeasures, which may impact the antimicrobial activity against mirror bacteria were the latter were created.

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Evaluation of polygenic risk scores and ambient air pollutants for lung cancer risk stratification in a lung cancer screening cohort

Trap, L.; Buyukcelik, R.; Antonissen, N.; Sidorenkov, G. A.; Ruiter, R.; Van Heemst, J.; Sedaghati-Khayat, B.; Stikker, B. S.; Dumoulin, D. W.; Gietema, H. A.; Heuvelmans, M. A.; Mohamed Hoesein, F. A. A.; De Jong, P. A.; Uitterlinden, A. G.; Brusselle, G.; Jacobs, C.; Aerts, J. G. J. V.; Vermeulen, R. C. H.; De Bock, G. H.; Groen, H. J. M.; Vliegenthart, R.; Downward, G. S.; Stadhouders, R.; Van Rooij, J.; NELSON-POP consortium,

2026-07-16 respiratory medicine 10.64898/2026.07.14.26358054 medRxiv
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Background: Randomized controlled trials have shown that computed tomographic (CT) screening reduces lung cancer mortality. Improved identification of at-risk groups, by leveraging non-smoking risk factors, could help refine screening selection. Aim: To evaluate polygenic risk scores (PRSs) and ambient air pollution (AAP) exposure for risk stratification in the NELSON lung cancer screening cohort. Methods: Two PRSs (PRS-McKay/PRS-Byun) and several AAPs (including nitrogen dioxide, ozone, and particulate matter [PM]) were assessed in the NELSON lung cancer screening trial (N=7,364). PRSs were validated in the Rotterdam Study (N=11,493). Associations with lung cancer, mortality, screening results, and discriminative ability to distinguish lung cancer were evaluated. Results: PRS-McKay and PRS-Byun were associated with lung cancer (odds ratio [OR] per SD [95%CI]: 1.22 [1.08-1.37] and 1.28 [1.13-1.44], respectively) and lung cancer-specific mortality (OR [95%CI]: 1.24 [1.05-1.47], for both), but not with non-lung cancer mortality (OR [95%CI]: 1.01 [0.94-1.10] and 1.03 [0.95-1.12], respectively). Exposure to PM2.5 was associated with lung cancer (OR [95%CI]: 1.11 [1.01-1.22]). PM constituents were associated with adenocarcinoma, particularly PM10 (OR [95%CI]: 1.16 [1.01-1.32]) and ultra-fine particles (OR [95%CI]: 1.16 [1.04-1.30]). PRS and AAP added modestly to the discriminative ability for lung cancer on top of pack-years, age, and sex (area under the curve [95%CI]: 0.659 [0.624-0.695] vs. 0.643 [0.608-0.679]). Conclusions: PRSs and exposure to PM were associated with lung cancer in a high-risk screening population. The primary potential of PRSs may reside in refining lung cancer screening selection toward individuals at higher risk of dying from lung cancer specifically.

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A study of PROGRESS: the Therapeutic Potential of 17 OHPC on the Pathophysiology of Severe Preeclampsia

Brewerton, C. H.; Chambers, C. L.; Belk, S.; Wallace, K.; Roseburg, M.; Campbell, N.; Neeley, Y.; Dodd, C.; Morris, r.; Novotny, S.; Tucker, J. M.; LaMarca, B. B.; Amaral, L. M.

2026-07-17 obstetrics and gynecology 10.64898/2026.07.15.26358196 medRxiv
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Preeclampsia (PE), new onset hypertension after 20 weeks of gestation, affects 10% of all pregnancies in the U.S. and it is associated with progesterone deficiency, chronic inflammation, elevated angiotensin II type 1 receptor agonistic autoantibody (AT1-AA) and endothelial dysfunction. Progesterone, through its receptors, stimulates an anti- inflammatory protein called Progesterone Induced Blocking Factor (PIBF) which decreases during various pregnancy disorders. Therefore, this study was designed to test the hypothesis that a progestogen, in the form of 17-hydroxyprogesterone caproate, stimulates PIBF, lowers vasoactive mechanisms which reduces maternal blood pressure in women with early-onset preeclampsia (EOPE). PE women received 17-OHPC (250 mg, I.M.) and blood draws were collected before and after 17-OHPC supplementation. Placentas were collected at the delivery. 17-OHPC prolonged time of delivery beyond 72h on average and maternal blood pressure was significantly decreased in PE+17- OHPC. Progesterone and PIBF levels were reduced in PE group vs. NP group. Importantly, 17-OHPC increased PIBF and decreased vasoactive mechanisms and markers of inflammation. In conclusion, 17-OHPC or progesterone supplementation improves maternal outcomes in response to EOPE without causing further harm to the fetus.

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A Study Of Factors Influencing Fetal Monitor Failure

Tsanligrenchin, D.; Enkhjargal, E.-U.; Boldbaatar, O.; Shagdar, I.; Tumurtogoo, A.; Tuya, A.; Batbold, S.

2026-07-15 obstetrics and gynecology 10.64898/2026.07.12.26357884 medRxiv
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In Mongolia, an average of 65,000 women become pregnant each year, and about 59,500 babies are born. Although the number of pregnancies is decreasing by 8-12 percent each year, the level of fetal monitor usage remains high. The capital's maternity hospital currently has 27 fetal monitors in use, and an average of 30-35 calls are recorded per month. However, there is a lack of research on the use of fetal monitors, the causes and influencing factors of damage, and the organization of technical services. Therefore, this topic was chosen to determine the usage status of fetal monitors, the causes of malfunctions, and ways to improve them. Purpose To study the causes and factors affecting possible damage and injury during the use of fetal monitors, and to identify ways to reduce them. Materials and methods A one-time study was conducted on 10 MT-610 fetal monitors that were put into operation in 2019 at the Urgo Maternity Hospital in the capital. Data were collected and processed using document analysis methods from the technical passports and call logs of these devices. The factors contributing to common failures were identified using focus group interviews with the engineers and technicians responsible for the equipment. Results This study found that fetal monitor failures are caused by improper use, lack of regular calibration, electrical fluctuations, ambient temperature and humidity, and insufficient medical staff skills, training, and knowledge of how to use the device, all of which contribute to failures and measurement errors. It is also observed that when a replacement part is needed for a monitor that frequently breaks, the monitor is more likely to break again if it is used as a replacement from a previously broken monitor. Therefore, training doctors and nurses who replace spare parts on their use has been observed to significantly reduce future breakdowns. Conclusion According to the study results, the breakdowns and failures of fetal monitoring devices are mainly related to internal system failures, unstable power supply, and wear and tear of accessories and mechanical parts. The highest percentage of device failures indicates the need for special attention to the reliability of the device's basic functions. Additionally, the high percentage of accessory and printer failures indicates the need for proper use and monitoring of the entire device. In addition to technical factors, human misuse, lack of maintenance, and environmental influences also play a significant role in damage. Therefore, it is concluded that to ensure the reliable operation of fetal monitors, it is necessary to perform regular maintenance, stabilize the power supply, improve the quality of accessories, and increase the knowledge and skills of medical staff. Keywords: Fetal Monitoring, Equipment Failure, Risk Factors

10
Multiparameter optimization extends the lifetime of cell-free protein synthesis in a high-throughput format

Bozkurt, E. U.; Zanchet, B.; Nikel, P. I.; Volke, D. C.

2026-07-15 molecular biology 10.64898/2026.07.15.738603 medRxiv
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Cell-free protein synthesis (CFPS) is a powerful platform for synthetic biology, yet the factors governing reaction longevity remain poorly understood despite their importance for high-throughput applications. Here, the three principal determinants of CFPS performance--DNA template design, reaction composition, and lysate genotype--were systematically optimized to extend reaction lifetime in a 384-well plate format. Different energy regeneration systems were evaluated through real-time pH monitoring and metabolomic analyses to identify the metabolic constraints limiting prolonged protein synthesis. Lysates prepared from engineered Escherichia coli BL21(DE3) strains were further examined to assess the contributions of DNA, RNA, and amino acid stabilization. Systematic optimization of amino acid, nucleoside triphosphate, polyethylene glycol, and lysate concentrations identified DNA template stability and amino acid preservation as the primary factors sustaining CFPS activity. Combining these improvements yielded reactions that remained productive for >14 h and produced 567 {+/-} 64 g mL-1 active deGFP. These findings establish practical strategies for extending CFPS lifetime and improving high-throughput cell-free platforms.

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Knowledge and Associated Factors Influencing Oral Care Provision Among ICU Nurses Caring for Mechanically Ventilated Patients at Tenwek Hospital, Kenya

Mukthar, V. K.; Tuei, S.; Towett, P.

2026-07-16 nursing 10.64898/2026.07.13.26357953 medRxiv
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Background: Oral care is a critical nursing intervention for mechanically ventilated patients in intensive care units because it reduces oral microbial colonization and contributes to the prevention of ventilator-associated pneumonia, a major cause of morbidity, prolonged hospitalization, and increased healthcare costs among critically ill patients. Despite the availability of evidence-based guidelines, gaps in nurses knowledge and inconsistent implementation of oral care practices remain challenges, particularly in low- and middle-income settings. Objective: This study aimed to assess the level of knowledge among intensive care unit nurses regarding oral care for mechanically ventilated patients at Tenwek Hospital, Kenya, determine factors influencing knowledge, and examine the relationship between nurses knowledge and selected demographic and professional characteristics. Methods: An analytical cross-sectional study design was employed. The study was conducted among intensive care unit nurses at Tenwek Hospital. A sample of 38 nurses was selected from a target population of 60 intensive care unit nurses using simple random sampling. Data were collected using a structured self-administered questionnaire assessing socio-demographic characteristics, knowledge of evidence-based oral care practices, awareness of guidelines, and factors influencing knowledge. Data were analyzed using descriptive statistics, chi-square tests, Pearson correlation, and logistic regression, with statistical significance set at probability value less than 0.05. Results: Thirty-five nurses participated, yielding a response rate of 92.1 percent. The findings demonstrated generally high knowledge levels regarding oral care practices for mechanically ventilated patients. Most nurses correctly identified recommended oral care frequency (88.6 percent), oral assessment before care (91.4 percent), suctioning before and after oral care (94.3 percent), and the role of oral care in preventing ventilator-associated pneumonia (97.1 percent). However, knowledge gaps were identified in areas such as toothbrushing practices and documentation of oral care procedures. Training, continuing professional education, availability of guidelines, workload, resources, supervision, and teamwork were identified as important factors influencing knowledge. The findings revealed that professional qualification (probability value equal to 0.02), intensive care unit experience (probability value equal to 0.030) and formal oral care training (probability value equal to 0.021) were significantly associated with nurses knowledge of oral care practices. Conclusion: Intensive care unit nurses at Tenwek Hospital demonstrated adequate knowledge of evidence-based oral care practices for mechanically ventilated patients. However, targeted educational interventions are required to address identified gaps and strengthen standardized oral care delivery. Continuous professional development, consistent use of guidelines, supportive supervision, and adequate resource provision are recommended to enhance patient safety and reduce preventable intensive care unit complications such as ventilator-associated pneumonia. Keywords: Intensive care unit nurses; Oral care; Mechanically ventilated patients; Ventilator-associated pneumonia; Nursing knowledge; Evidence-based practice

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PARIS (Pneumonia: Acute Respiratory Infection +/- Sepsis): a prospective single-centre observational cohort study of hospitalised patients with pneumonia

Nasser, S. T.; Piercy, C. R.; Falinska, A.; O'Sullivan, D. M.; Devonshire, A.; Martinez-Estrada, F.; Huggett, J.; Creagh-Brown, B. C.

2026-07-17 respiratory medicine 10.64898/2026.07.15.26357955 medRxiv
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Introduction Hospitalised community-acquired pneumonia (CAP) is heterogeneous in aetiology, severity, and outcome. Phenotyping and endotyping approaches offer potential to stratify patients biologically and guide targeted therapy, but require well-characterised cohorts with linked biosamples. We describe the PARIS (Pneumonia: Acute Respiratory Infection +/- Sepsis) study: a prospective observational cohort of hospitalised patients with pneumonia, designed to characterise functional outcomes and to provide a biobank for translational immunological research. Methods Adults admitted with CAP to a single NHS district general hospital were enrolled within 24 hours of admission between December 2020 and March 2022. Clinical, functional, and physiological data were collected at enrolment, hospital discharge, and 6-8 week follow-up. Serial blood samples were collected for flow cytometry, transcriptomics, pathogen DNA detection, and plasma biobanking. Results Forty-seven patients were enrolled (15 without and 32 with sepsis [SOFA >=2] at enrolment); 87% met sepsis criteria by 24 hours post enrolment. Most patients (30/47, 64%) were managed as COVID-19, microbiologically confirmed in 27. Mean age was 57 years (SD 16), 70% were male, and baseline comorbidity burden was low. Severity was moderate (median NEWS2 4 at enrolment, rising to 6 by 24 hours post enrolment; p<0.001). Mortality was 4/47 (8.5%), with 44/47 (94%) alive at hospital discharge. Median length of stay was 8 days (IQR 5.5-11). Translational samples were collected from the majority: fresh flow cytometry (44/47, 94%), transcriptomics from the sepsis subgroup (31/32, 97%), pathogen DNA sampling (35 samples received across study timepoints; see Table 5), and stored plasma (29/47, 62%). The primary outcome of functional decline (Barthel score decrease >=1.85) occurred in only 1/29 patients with paired assessments (3.4%). Persistent CRP elevation (>3 mg/L) at 6-8 week follow-up was present in 16/31 (52%) survivors with available data. Conclusions The PARIS cohort provides a well-characterised clinical platform and linked biobank to support translational studies of pneumonia and sepsis. The low rate of functional decline reflects the younger, lower-comorbidity, COVID-predominant population recruited. Primary protocol endpoints were not achieved owing to pandemic-related disruption. Data and samples underpin a programme of linked translational studies.

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Rest-Activity Rhythm Variability Across Clinical Episodes of Bipolar Disorder: Standalone Biomarker or Statistical Artifact?

Konicarova, C.-A.; Schneider, J.; Spaniel, F.; Kolenic, M.; Alda, M.; Bakstein, E.

2026-07-17 psychiatry and clinical psychology 10.64898/2026.07.15.26358139 medRxiv
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Background: Actigraphy-derived rest-activity rhythm (RAR) features are widely used to characterize clinical states in bipolar disorder (BD). Both mean levels and temporal variability of these features have been associated with mood episodes; however, variability measures are often statistically coupled with the mean, particularly in skewed distributions. This raises a question as to whether variability reflects a separate characteristic of the data or whether the observed association arises from statistical properties of the data. Objective: In this study, we aim to determine whether temporal variability of actigraphy-derived RAR features provides standalone information on mood episodes in BD beyond mean activity levels after accounting for mean-variance dependence. Methods: We analyzed actigraphy data from a subset of 72 participants with BD drawn from a larger longitudinal study, extracting 22 daily RAR features aggregated weekly as sample mean (MEAN) and within-week temporal variability computed as sample standard deviation (VAR). Variance-stabilizing transformations (Box-Cox or Yeo-Johnson) were applied to the entire study cohort to reduce mean-variance dependence. Associations with mood episodes and remission (mania: n=34; depression: n=58 annotated participants) were evaluated using generalized linear mixed-effects models with a logistic link function, including univariate (MEAN or VAR) and multivariate (MEAN+VAR) specifications, assessed by likelihood-based metrics and the area under the receiver operating characteristic curve (AUC). Results: Transformations reduced mean-absolute correlations from 0.43 to below 0.06. Temporal variability remained significantly associated with clinical state for 11/22 RAR features in mania and 16/22 features in depression, with all significant associations remaining after false discovery rate correction (p<0.05). Joint models showed modest incremental gains (AUC 3%-4% overall; up to 12% in mania, 7% in depression), with absolute performance remaining limited (AUC 0.50-0.66). In both mania and depression, nearly all significant variability-based regressors contributed incremental information beyond mean-based models. Only sleep duration and activity changes around wake time (+-1 hour), did not improve discrimination between mania and remission. Conclusions: Temporal variability in RAR features can be considered a standalone state marker of mood episodes not captured by mean activity. We found it to be more consistently associated with depression than mania. Its incremental discriminative contribution is modest, suggesting greater utility within multivariate or multimodal frameworks.

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Photobiomodulation promotes wound healing and functional improvement following lumbar decompression surgery: a double-blinded, placebo-controlled study

Rivera, J.; Zhou, Y.; Sak, L.; Pudewa, F.; Lee, J.; Yamamoto, M. T.; Yoo, H.; Lum, M.; Zhang, M.; Patel, A.; Vandenberghe, L. E.; Fenn, S. K.; Wang, Y.; Bailey, B.; Holley, S. M.; Vivas, A. C.; Holly, L. T.; Lu, D. C.

2026-07-17 surgery 10.64898/2026.07.15.26357882 medRxiv
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Objective: Photobiomodulation therapy has emerged as a promising modality to facilitate scar healing and pain management in dermatology and plastic surgery. However, its role in postoperative care following spine surgeries remains understudied. This double-blinded, placebo-controlled study aimed to investigate the effects of photobiomodulation in patients with chronic lower back pain undergoing lumbar decompression, with postoperative wound healing as the primary outcome and pain reduction and functional recovery as secondary outcomes. Methods: Patients were randomized to receive either active photobiomodulation braces (N=13) or placebo braces (N=12). Follow-up assessments were performed at 2, 4, 6, 8, and 12 weeks postoperatively. Outcomes included wound healing (Stony Brook Scar Evaluation Scale), back and leg pain (Visual Analog Scale), quality of life (EuroQol 5D), and functional status (Oswestry Disability Index). Results: Compared to the placebo group, the photobiomodulation treatment group had a 4.12-fold cumulative improvement in final scar scores, with significant between-group differences at postoperative weeks 6, 8, and 12 (p = 0.0062, 0.010, 0.042). Among patients with severe preoperative disability, treatment resulted in a 1.89-fold faster improvement in back pain (p=0.025) and a 1.80-fold faster improvement in ODI scores (p=0.025); and superior treatment effect on wound healing were again observed at weeks 6, 8, and 12. Among patients with poor initial scars, treatment led to a significantly better scar outcome than placebo at week 6 and a 1.94-fold faster EQ5D improvement (p=0.052), with significant gains observed as early as two weeks after surgery. There were no adverse events associated with photobiomodulation treatment. Conclusions: Photobiomodulation significantly promoted postoperative wound healing following lumbar decompression surgery, with therapeutic benefits preserved even in patients with poor baseline scar scores and functional impairment. This indicates that the efficacy of photobiomodulation is not limited by the initial scar condition or disability, supporting its broad clinical applicability. Additionally, patients with severe preoperative disability experienced greater benefits from photobiomodulation than placebo, including faster reduction in back pain and more rapid improvement in functional capacity, highlighting its role in postoperative pain management and rehabilitation. These therapeutic effects are likely mediated by photobiomodulation-induced reduction of inflammation and enhancement of tissue repair. Together, this study suggests that photobiomodulation can be a promising adjunct therapy to facilitate postoperative recovery in patients undergoing spine surgery.

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Reconsidering the case against risk prediction in self-harm: routinely collected health data distinguishes groups at higher and lower risk of adverse outcomes following paracetamol overdose

Oxley, J.; Schölin, L.; Brennan, G.; Anand, A.; Brett, J.; Eddleston, M.; Humphries, C.

2026-07-17 psychiatry and clinical psychology 10.64898/2026.07.15.26358127 medRxiv
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Background. UK clinical guidance recommends that structured risk prediction tools and risk stratification should not be used in self-harm, to predict suicide or determine who is offered treatment. Underpinning this position is the premise that routinely collected health data contain no useful predictive signal, which has received little direct scrutiny. Objective. To test whether routinely collected electronic health record data can distinguish groups at higher and lower risk of severe outcomes following paracetamol overdose. Methods. We analysed 4,095 adults presenting to NHS Lothian emergency departments with paracetamol overdose (2017-2023). Elastic-net logistic regression was fitted to 37 routinely collected electronic health record features to predict a composite of death or mental health inpatient admission at 0-7, 8-30 and 31-365 days following attendance, evaluated on a held-out 20% test set with bootstrapping. Findings. Events occurred in 5.5% of patients at 0-7 days, 2.0% at 8-30 days and 7.9% at 31-365 days, dominated by mental health admission. Bootstrap AUROC 95% confidence intervals lay above 0.5 in every window (0.65-0.82, 0.63-0.90, 0.71-0.85): models ranked patients better than chance. Calibration slopes (1.04, 1.14, 1.07) were close to one. Ranking drew primarily on mental health-related features. Conclusions. Routinely collected health data carried predictive signal for severe outcomes after paracetamol overdose, although discrimination fell short of what is needed for individual-level clinical use. Clinical implications. These models are not proposed for clinical deployment; however, treating risk prediction as a settled question will redirect research efforts, potentially excluding this patient population from machine learning advances driving improvements in care in other medical specialties.

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Microvascular Thrombosis and Acute Kidney Injury in COVID-19: A Systematic Review and Quantitative Analysis

Duarte, C. A.; Uscocovich, V. S. M.; Misael, I.; Duarte, P. D. A. C.; Sestito, E. B.; Da SIlva, P. N.

2026-07-17 nephrology 10.64898/2026.07.14.26357748 medRxiv
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Abstract Objective: To synthesize the available evidence on the association between SARS-CoV-2-related microvascular thrombosis and acute kidney injury (AKI), with emphasis on renal outcomes, mortality, and renal replacement therapy requirements. Methods: This systematic review followed the PRISMA 2020 statement and was prospectively registered in PROSPERO (CRD420251132701). PubMed/MEDLINE, Scopus, and Embase were searched for systematic reviews, including meta-analyses, and umbrella reviews investigating the association between SARS-CoV-2-related microvascular thrombosis and acute kidney injury. Two reviewers independently performed study selection, data extraction, and methodological quality assessment using AMSTAR-2 and ROBIS. Evidence was synthesized through a structured narrative synthesis supported by quantitative data extracted from the included reviews. Results: Six evidence syntheses evaluating kidney involvement, thrombotic events, and microvascular mechanisms in COVID-19 were included. AKI incidence was 9.2% (95%CI 4.6-13.9) among hospitalized patients and 32.6% (95%CI 8.5-56.6) among critically ill patients. In children with multisystem inflammatory syndrome associated with SARS-CoV-2, AKI incidence was 20% (95%CI 14-28). Microvascular or thrombotic events were associated with adverse renal outcomes (OR 2.14; 95%CI 1.32-3.48). AKI was associated with increased mortality (OR 4.68; 95%CI 1.06-20.70) and greater likelihood of renal replacement therapy requirement (OR 2.87; 95%CI 1.45-5.68). The certainty of evidence ranged from moderate to high for the principal outcomes. Conclusion: Current evidence supports an important association between microvascular thrombotic injury and COVID-19-associated AKI. These findings reinforce the relevance of endothelial dysfunction and thromboinflammatory pathways in kidney involvement during COVID-19 and highlight the need for early renal monitoring, risk stratification, and kidney-protective strategies in high-risk patients. Keywords: COVID-19; Acute Kidney Injury; Microvascular Thrombosis; SARS-CoV-2; Renal Replacement Therapy; Systematic Review

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Portable Ultra-Low Field MRI Deep-Learning Algorithms for White Matter Lesion Segmentation Improve Accuracy and Reflect Clinical Disability in Multiple Sclerosis

Thommana, A. A.; Donnay, C. A.; Norato, G.; Gaitan, M. I.; Griffanti, L.; Nair, G.; Reich, D. S.; Okar, S. V.

2026-07-17 neurology 10.64898/2026.07.15.26357954 medRxiv
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White matter lesion (WML) identification, assessment, and characterization using magnetic resonance imaging (MRI) are fundamental for diagnosis and monitoring of multiple sclerosis (MS). Portable ultra-low field (pULF) MRI at 64 millitesla (mT) has been shown to visualize WML with at least one dimension greater than 4 mm. An automated WML segmentation tool catered to pULF-MRI can provide standardized and accurate quantitative measurements of WML volume. In this study, we sought to investigate and compare the accuracy of machine-learning (ML) and deep-learning (DL) pULF MRI segmentation tools. Same-day paired pULF (64mT) and high-field (HF, 3T) MRI scans from 84 adults with MS or suspected-MS (mean age {+/-} SD: 48 {+/-} 13, 62 females) included T2-FLAIR and T1w images. Reference WML segmentations were manually annotated on pULF T2-FLAIR for all scans, with WML confirmed with registered HF T2-FLAIR. HF reference WML segmentations were created. Four automated segmentation methods were applied to pULF scans: Method for Inter-Modal Segmentation Analysis (MIMoSA), an ML algorithm trained on HF WML masks; WMH-SynthSeg, a convolutional neural network model with flexible segmentation capabilities across field strengths and resolution; nnU-Net, a DL algorithm trained on pULF reference WML masks; and Pseudo-Label Assisted nnU-Net (PLAn), a DL algorithm pre-trained on HF reference WML masks and refined with 64mT reference WML masks. Two models were trained with nnU-Net, one using T2-FLAIR images only (nnU-Net-FL) and one using T1w and T2-FLAIR images (nnU-Net-FL/T1). The same was done with PLAn, creating PLAn-FL and PLAn-FL/T1. The six automated WML segmentation outputs were compared to the manual segmentations to determine Dice Similarity Coefficient (DSC) scores. Associations of WML volume estimates with clinical measures were investigated. DSC scores with pULF reference WML masks from PLAn-FL (DSC mean {+/-} SD: 0.50 {+/-} 0.24) outperformed MIMoSA (0.24 {+/-} 0.20, p < 0.0001), WMH-SynthSeg (0.30 {+/-} 0.18, p < 0.0001), nnU-Net-FL (0.41 {+/-} 0.24, p < 0.0001), and nnU-Net-FL/T1 (0.41 {+/-} 0.26, p = 0.0004). Worse Expanded Disability Status Scale (EDSS) and Scripps Neurologic Rating Scale (SNRS) scores were correlated with higher WML volumes in the pULF and HF reference masks. They were also correlated with WML volumes derived from WHM-SynthSeg, nnU-Net-FL, nnU-Net-FL/T1, PLAn-FL, and PLAn-FL/T1, but not MIMoSA. After adjusting for age, WHM-SynthSeg, nnU-Net FL, nnU-Net-FL/T1, PLAn-FL, and PLAn-FL/T1 had significant associations with EDSS and SNRS scores. nnU-Net and PLAn performed best in segmenting WML on pULF-MRI at 64 mT, providing accurate quantitative estimates of WML burden. Moreover, WML volumes estimated by these algorithms were associated with clinical measures of disability, underscoring their utility for reflecting clinical and radiological disease severity. Given pULF-MRI's mobility and lower cost, these findings highlight its relevance in clinical trials, particularly in involving more participants who face logistical constraints and barriers.

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Comparing different neuroimaging modalities for quantification of the cholinergic system in Parkinson's disease

d'Angremont, E.; Marschall, T. M.; Renken, R. J.; Sommer, I. E.

2026-07-17 neurology 10.64898/2026.07.15.26357522 medRxiv
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Introduction Parkinson's disease (PD) is a multifactorial disorder, affecting multiple neurotransmitter systems, including the cholinergic system. Cholinergic denervation is heterogeneous across patients and difficult to predict based on clinical presentation. In this study, we assessed the sensitivity of structural MRI (sMRI) and functional MRI (fMRI) to cholinergic degeneration related to PD and to cognitive functioning in PD. We compared our results to results from previously reported [18F]Fluoroethoxybenzovesamicol ([18F]FEOBV) PET imaging, which is considered the gold standard for cholinergic imaging. Methods 34 PD patients and 10 healthy controls underwent structural T1-weighted MRI. A subset of 14 patients and 9 controls also underwent resting-state fMRI. We extracted the bilateral volumes of the nucleus basalis of Meynert (NBM) from the sMRI images. Functional connectivity (FC) from the NBM to the cortex (NBM-FC) was determined using fMRI data. Principal component analysis (PCA) was applied to reduce the dimensionality of the NBM-FC images. We assessed performances for NBM-FC in distinguishing patients from controls using stepwise logistic regression. Similarly, NBM volume was used using logistic regression. Furthermore, the relation between these measures and cognitive function in several domains was investigated with (stepwise) linear regression. Leave-one-out cross validation (LOOCV) and bootstrapping was performed to assess robustness of the results. Results NBM-FC was well able to discriminate patients from controls with an AUC of 0.84 (95% CI: 0.62-1). NBM volume showed lower performance, but was still better than chance: AUC: 0.75 (95% CI: 0.57-0.93). Significant correlations were found between 1) cognition in the attentional domain and NBM-FC (r=0.63; p=.015) and 2) global cognition and NBM volume (r=0.55, p=.001). These results were inferior to those previously reported using [18F]FEOBV tracer uptake (see Chapter 6). Bootstrapping revealed that NBM volume of only the left hemisphere was stably related to PD diagnosis and global cognition in PD patients. We found that a lower NBM-FC in specific brain areas, including the fusiform gyrus, supramarginal gyrus and dorsolateral prefrontal cortex, was related to PD diagnosis. Bootstrapping revealed no stable NBM-FC pattern related to attention. Conclusion Although MRI results were slightly inferior to [18F]FEOBV PET data, MRI may provide a cheaper and more widely available alternative for cholinergic imaging. We recommend testing the utility of MRI as predictor and monitor of cholinergic treatment effect in a longitudinal study.

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Machine learning and data-driven models for predicting post-stroke dysphagia: a systematic review and meta-analysis

Mohammadi Yazdi, S.; Motevaselian, M.; Khatami, S.; Radfar, N.; jourahmad, z.; Perez, H. A.

2026-07-17 neurology 10.64898/2026.07.15.26358113 medRxiv
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Background: Post-stroke dysphagia (PSD) contributes to aspiration, pneumonia, malnutrition, prolonged hospitalization and mortality. We evaluated the discrimination, validity and readiness of machine learning and data-driven prediction models for PSD-related outcomes. Methods: Following a prospectively registered protocol (PROSPERO CRD420261419259), we searched PubMed/MEDLINE, Embase, Web of Science Core Collection, CINAHL and CENTRAL from inception through June 7, 2026. Eligible studies developed or validated multivariable prediction models for PSD-related outcomes in adults with stroke. We used PROBAST and PROBAST+AI to assess risk of bias and applicability and TRIPOD+AI to evaluate reporting. Area under the curve (AUC) estimates were pooled on the logit scale with random-effects models. Results: Twenty-four studies were included and ten contributed to meta-analysis. Four studies predicting early or incident PSD yielded a pooled AUC of 0.94 (95% CI 0.60-0.99; I2 = 95.6%). Pooled AUCs were 0.84 (95% CI 0.71-0.92) for aspiration or penetration-aspiration and 0.89 (95% CI 0.24-1.00) for severe dysphagia. The exploratory analysis of all ten risk-prediction models produced an AUC of 0.90 (95% CI 0.80-0.95), but heterogeneity was substantial (I2 = 90.3%) and the prediction interval was 0.51-0.99. Every study had high risk of bias because of analysis-domain concerns; calibration and external validation were uncommon. Conclusions: Reported discrimination was often high, but the evidence does not establish reliable performance in care. Independent validation, calibration, complete model reporting and clinical-impact studies are needed before these models guide post-stroke swallowing care. Keywords: Post-stroke dysphagia; Stroke; Deglutition disorders; Machine learning; Clinical prediction model; Area under the curve; Meta-analysis

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How Do Nurses Make Clinical Decisions Via Remote Reviews: A Convergent Mixed-Methods Study

Zhang, Y.; Sutherland, S.; GREENWAY, K.; Stayt, L.

2026-07-17 nursing 10.64898/2026.07.15.26357946 medRxiv
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Abstract Background: Remote clinical reviews have become an integral component of contemporary nursing practice across community and acute care settings. Nurses increasingly make autonomous clinical decisions using telephone, video, and online/digital systems, often with limited sensory information and under conditions of uncertainty. However, empirical understanding of how nurses make clinical decisions via remote reviews remains limited. Aim: To explore and understand how registered nurses (RNs) make clinical decisions about patient care via remote reviews. Methods: A convergent mixed-methods design was employed. Quantitative data (analytic quantitative sample N=53) were collected using validated questionnaires that measured decision-making processes, physician-nurse collaboration, decision-making stress, and perceived decision-making ability. Qualitative data (N=23) were generated through semi-structured interviews. Data collection took place between October 2024 and April 2025. Quantitative data were analysed using descriptive statistics, correlation, and multiple regression. Qualitative data were analysed using framework analysis. Integration was achieved through pillar-building and theory-driven synthesis and illustrated by joint display tables. Results: Most nurses demonstrated a flexible decision-making style, integrating analytical and intuitive reasoning. Both analytical and intuitive processes were positively associated with perceived decision-making ability. Physician-nurse collaboration emerged as a strong predictor of decision-making confidence, while decision-related stress was not a significant predictor. Qualitative findings identified three themes: characteristics of remote review; making adaptive decisions shaped by both internal and external constraints and enablers; and external influencing factors. The integrated findings informed a theory-informed ICE framework to illustrate how nurses make clinical decisions via remote reviews. Conclusion: Remote clinical decision-making is a dynamic cognitive-environmental process rather than a purely individual cognitive act. The ICE framework conceptualises this interaction, extending existing decision-making theories to digitally mediated care. Impact: Understanding remote decision-making supports training design, clinical governance, and the development of Artificial Intelligence-enhanced decision-support tools grounded in ecological bounded rationality. Patient or Public Contribution: Patient and public representatives contributed to stakeholder discussions that informed the development of the interview topic guide and the theoretical model. Patients or members of the public were not involved in recruitment, data collection, analysis, interpretation of findings, or preparation of the manuscript. Keywords: clinical decision-making, remote reviews, telehealth, nursing, mixed methods, ecological bounded rationality