1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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2. |
- Dong, Yi, et al.
(author)
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Anosmia, mild cognitive impairment, and biomarkers of brain aging in older adults
- 2023
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In: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 19:2, s. 589-601
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Journal article (peer-reviewed)abstract
- Olfactory impairment is a potential marker for prodromal dementia, but the underlying mechanisms are poorly understood. This population-based study included 4214 dementia-free participants (age ≥65 years). Olfaction was assessed using the 16-item Sniffin’ Sticks identification test. In the subsamples, we measured plasma amyloid beta (Aβ)40, Aβ42, total tau, and neurofilament light chain (NfL; n = 1054); and quantified hippocampal, entorhinal cortex, and white matter hyperintensity (WMH) volumes, and Alzheimer's disease (AD)-signature cortical thickness (n = 917). Data were analyzed with logistic and linear regression models. In the total sample, mild cognitive impairment (MCI) was diagnosed in 1102 persons (26.2%; amnestic MCI, n = 931; non-amnestic MCI, n = 171). Olfactory impairment was significantly associated with increased likelihoods of MCI, amnestic MCI, and non-amnestic MCI. In the subsamples, anosmia was significantly associated with higher plasma total tau and NfL concentrations, smaller hippocampal and entorhinal cortex volumes, and greater WMH volume, and marginally with lower AD-signature cortical thickness. These results suggest that cerebral neurodegenerative and microvascular lesions are common neuropathologies linking anosmia with MCI in older adults.
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3. |
- Han, Xiaolei, et al.
(author)
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Accelerometer-measured sedentary behavior patterns, brain structure, and cognitive function in dementia-free older adults : a population-based study
- 2023
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In: Journal of Alzheimer's Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 96:2, s. 657-668
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Journal article (peer-reviewed)abstract
- Background: Sedentary behavior is associated with cognitive impairment, but the neuropathological mechanisms underlying their associations are poorly understood.Objective: To investigate the associations of accelerometer-measured sedentary behavior patterns with brain structure and cognition, and further to explore the potential mechanisms.Methods: This community-based study included 2,019 older adults (age≥60 years, 59% women) without dementia derived from participants in the baseline examination of MIND-China (2018-2020). We assessed sedentary parameters using an accelerometer and cognitive function using a neuropsychological test battery. Structural brain markers were assessed on the structural brain MRI scans in a subsample (n = 1,009). Data were analyzed using the general linear, isotemporal substitution, and mediation models.Results: In the total sample (n = 2,019), adjusting for multiple covariates and moderate-to-vigorous-intensity physical activity, longer mean sedentary bout duration was linearly related with lower z-scores of global cognition, verbal fluency, and memory (ptrend < 0.05), whereas greater total sedentary time was linearly associated with lower z-scores of global cognition, verbal fluency, and memory only among individuals with long sedentary time (>10 h/day) (ptrend < 0.05); Breaking up sedentary time with same amount of light-intensity physical activity was significantly associated with higher verbal fluency and memory z-scores (p < 0.05). In the MRI subsample (n = 1,009), separately entering structural brain MRI markers into the mediation models substantially attenuated the associations of mean sedentary bout duration with global cognition, verbal fluency, and memory z-scores.Conclusion: Prolonged uninterrupted sedentary time is associated with poor global cognition, memory, and verbal fluency among rural older adults, and structural brain markers could partially mediate the association.
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4. |
- Jin, Ying-Hui, et al.
(author)
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Chemoprophylaxis, diagnosis, treatments, and discharge management of COVID-19 : An evidence-based clinical practice guideline (updated version)
- 2020
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In: Military Medical Research. - : Springer Science and Business Media LLC. - 2054-9369. ; 7:1
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Journal article (peer-reviewed)abstract
- The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, coronavirus disease 2019 (COVID-19), affecting more than seventeen million people around the world. Diagnosis and treatment guidelines for clinicians caring for patients are needed. In the early stage, we have issued "A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)"; now there are many direct evidences emerged and may change some of previous recommendations and it is ripe for develop an evidence-based guideline. We formed a working group of clinical experts and methodologists. The steering group members proposed 29 questions that are relevant to the management of COVID-19 covering the following areas: chemoprophylaxis, diagnosis, treatments, and discharge management. We searched the literature for direct evidence on the management of COVID-19, and assessed its certainty generated recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Recommendations were either strong or weak, or in the form of ungraded consensus-based statement. Finally, we issued 34 statements. Among them, 6 were strong recommendations for, 14 were weak recommendations for, 3 were weak recommendations against and 11 were ungraded consensus-based statement. They covered topics of chemoprophylaxis (including agents and Traditional Chinese Medicine (TCM) agents), diagnosis (including clinical manifestations, reverse transcription-polymerase chain reaction (RT-PCR), respiratory tract specimens, IgM and IgG antibody tests, chest computed tomography, chest x-ray, and CT features of asymptomatic infections), treatments (including lopinavir-ritonavir, umifenovir, favipiravir, interferon, remdesivir, combination of antiviral drugs, hydroxychloroquine/chloroquine, interleukin-6 inhibitors, interleukin-1 inhibitors, glucocorticoid, qingfei paidu decoction, lianhua qingwen granules/capsules, convalescent plasma, lung transplantation, invasive or noninvasive ventilation, and extracorporeal membrane oxygenation (ECMO)), and discharge management (including discharge criteria and management plan in patients whose RT-PCR retesting shows SARS-CoV-2 positive after discharge). We also created two figures of these recommendations for the implementation purpose. We hope these recommendations can help support healthcare workers caring for COVID-19 patients.
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5. |
- Li, Yuanjing, et al.
(author)
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Lifelong Cognitive Reserve, Imaging Markers of Brain Aging, and Cognitive Function in Dementia-Free Rural Older Adults : A Population-Based Study
- 2023
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In: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 92:1, s. 261-272
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Journal article (peer-reviewed)abstract
- Background: Cognitive reserve (CR) partly explains cognitive variability in the presence of pathological brain aging.Objective: We investigated the interplay of lifelong CR with age, sex, and brain aging markers in cognitive phenotypes among older adults with very limited education.Methods: This population-based cross-sectional study included 179 dementia-free participants (age ≥65 years; 39.7% women; 67.0% had no or elementary education) examined in 2014–2016. We assessed lacunes and volumes of hippocampus, ventricles, grey matter, white matter (WM), and white matter hyperintensities. Lifelong CR score was generated from six lifespan intellectual factors (e.g., education and social support). We used Mini-Mental State Examination (MMSE) score to assess cognition and Petersen’s criteria to define mild cognitive impairment (MCI). Data were analyzed using general linear and logistic models.Results: The association of higher lifelong CR score (range: –4.0–5.0) with higher MMSE score was stronger in women (multivariable-adjusted β-coefficient and 95% CI: 1.75;0.99–2.51) than in men (0.68;0.33–1.03) (pinteraction = 0.006). The association of higher CR with MCI (multivariable-adjusted odds ratio and 95% CI: 0.77;0.60–0.99) did not vary by age or sex. Among participants with low CR (<1.4[median]), greater hippocampal and WM volumes were related to higher MMSE scores with multivariable-adjusted β-coefficients being 1.77(0.41–3.13) and 0.44(0.15–0.74); the corresponding figures in those with high CR were 0.15(–0.76–1.07) and –0.17(–0.41–0.07) (pinteraction <0.01). There was no statistical interaction of CR with MRI markers on MCI.Conclusion: Greater lifelong CR capacity is associated with better late-life cognition among people with limited education, possibly by compensating for impact of neurodegeneration.
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6. |
- Campbell, PJ, et al.
(author)
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Pan-cancer analysis of whole genomes
- 2020
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In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
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Journal article (peer-reviewed)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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7. |
- Fa, Wenxin, et al.
(author)
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Associations of Blood Absolute Neutrophil Count and Cytokines With Cognitive Function in Dementia-Free Participants : A Population-Based Cohort Study
- 2023
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In: The journals of gerontology. Series A, Biological sciences and medical sciences. - 1079-5006 .- 1758-535X.
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Journal article (peer-reviewed)abstract
- Background: The relationships of neutrophils and cytokines with cognitive dysfunction are poorly defined. We aimed to investigate the association of peripheral blood absolute neutrophil count (ANC) with cognitive function in older adults and to further explore the mediating role of serum cytokines in this association.Methods: This population-based cohort study included 1 666 dementia-free participants (age ≥60 years) derived from baseline examinations (March–September 2018) of the Multimodal Intervention to Delay Dementia and Disability in Rural China (MIND-China); of these, 1 087 participants completed follow-up examinations in October–December 2019. We used a neuropsychological test battery to assess episodic memory, verbal fluency, attention, and executive function at the baseline and follow-up examinations. We used Mindray BC-6800 automated hematology analyzer to measure ANC and Meso Scale Discovery to measure serum interleukin-6 (IL-6) and eotaxin-3.Results: The linear regression analysis of cross-sectional data at baseline (n = 1 666) suggested that increased ANC was significantly associated with a lower episodic memory z score (β coefficient: −0.149, 95% CI: −0.274 to −0.023) and lower long-delayed free recall z score (−0.216, −0.361 to −0.070). Serum IL-6 and eotaxin-3 could mediate 16.16% to 20.21% and 7.55% to 9.35%, respectively, of these associations. The analysis of longitudinal data (n = 1 087) showed a J-shaped relationship of ANC with decline in episodic memory z score (p for nonlinear = .049), and a U-shaped relationship between ANC and decline in long-delayed free recall z score (p for nonlinear = .043).Conclusions: Increased neutrophils are associated with poor cognitive performance and accelerated decline in episodic memory, and the cross-sectional association is partly mediated by serum cytokines.
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8. |
- Hsieh, HC, et al.
(author)
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Can a Bayesian belief network for survival prediction in patients with extremity metastases (PATHFx) be externally validated in an Asian cohort of 356 surgically treated patients?
- 2022
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In: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 93, s. 721-731
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Journal article (peer-reviewed)abstract
- Background and purpose: Predicted survival may influence the treatment decision for patients with skeletal extremity metastasis, and PATHFx was designed to predict the likelihood of a patient dying in the next 24 months. However, the performance of prediction models could have ethnogeographical variations. We asked if PATHFx generalized well to our Taiwanese cohort consisting of 356 surgically treated patients with extremity metastasis.Patients and methods: We included 356 patients who underwent surgery for skeletal extremity metastasis in a tertiary center in Taiwan between 2014 and 2019 to validate PATHFx’s survival predictions at 6 different time points. Model performance was assessed by concordance index (c-index), calibration analysis, decision curve analysis (DCA), Brier score, and model consistency (MC).Results: The c-indexes for the 1-, 3-, 6-, 12-, 18-, and 24-month survival estimations were 0.71, 0.66, 0.65, 0.69, 0.68, and 0.67, respectively. The calibration analysis demonstrated positive calibration intercepts for survival predictions at all 6 timepoints, indicating PATHFx tended to underestimate the actual survival. The Brier scores for the 6 models were all less than their respective null model’s. DCA demonstrated that only the 6-, 12-, 18-, and 24-month predictions appeared useful for clinical decision-making across a wide range of threshold probabilities. The MC was < 0.9 when the 6- and 12-month models were compared with the 12-month and 18-month models, respectively.Interpretation: In this Asian cohort, PATHFx’s performance was not as encouraging as those of prior validation studies. Clinicians should be cognizant of the potential decline in validity of any tools designed using data outside their particular patient population. Developers of survival prediction tools such as PATHFx might refine their algorithms using data from diverse, contemporary patients that is more reflective of the world’s population.
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9. |
- Lensink, Marc F., et al.
(author)
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Impact of AlphaFold on structure prediction of protein complexes: The CASP15-CAPRI experiment
- 2023
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In: Proteins. - : WILEY. - 0887-3585 .- 1097-0134.
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Journal article (peer-reviewed)abstract
- We present the results for CAPRI Round 54, the 5th joint CASP-CAPRI protein assembly prediction challenge. The Round offered 37 targets, including 14 homodimers, 3 homo-trimers, 13 heterodimers including 3 antibody-antigen complexes, and 7 large assemblies. On average similar to 70 CASP and CAPRI predictor groups, including more than 20 automatics servers, submitted models for each target. A total of 21 941 models submitted by these groups and by 15 CAPRI scorer groups were evaluated using the CAPRI model quality measures and the DockQ score consolidating these measures. The prediction performance was quantified by a weighted score based on the number of models of acceptable quality or higher submitted by each group among their five best models. Results show substantial progress achieved across a significant fraction of the 60+ participating groups. High-quality models were produced for about 40% of the targets compared to 8% two years earlier. This remarkable improvement is due to the wide use of the AlphaFold2 and AlphaFold2-Multimer software and the confidence metrics they provide. Notably, expanded sampling of candidate solutions by manipulating these deep learning inference engines, enriching multiple sequence alignments, or integration of advanced modeling tools, enabled top performing groups to exceed the performance of a standard AlphaFold2-Multimer version used as a yard stick. This notwithstanding, performance remained poor for complexes with antibodies and nanobodies, where evolutionary relationships between the binding partners are lacking, and for complexes featuring conformational flexibility, clearly indicating that the prediction of protein complexes remains a challenging problem.
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10. |
- Li, Yuanjing, et al.
(author)
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Association of Lifelong Cognitive Reserve with Dementia and Mild Cognitive Impairment among Older Adults with Limited Formal Education : A Population-Based Cohort Study
- 2023
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In: Dementia and Geriatric Cognitive Disorders. - 1420-8008 .- 1421-9824. ; 52:4, s. 258-266
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Journal article (peer-reviewed)abstract
- Introduction: Early-life educational attainment contributes to cognitive reserve (CR). We investigated the associations of lifelong CR with dementia and mild cognitive impairment (MCI) among older people with limited formal education. Methods: This population-based cohort study included 2,127 dementia-free participants (≥60 years; 59.4% women; 81.5% with no or elementary school) who were examined at baseline (August-December 2014) and follow-up (March-September 2018). Lifelong CR score at baseline was generated from six lifespan intellectual factors. Dementia, MCI, and their subtypes were defined according to the international criteria. Data were analyzed using Cox proportional-hazards models. Results: During the total of 8,330.6 person-years of follow-up, 101 persons were diagnosed with dementia, including 74 with Alzheimer's disease (AD) and 26 with vascular dementia (VaD). The high (vs. low) tertile of lifelong CR score was associated with multivariable-adjusted hazards ratios (95% confidence interval) of 0.28 (0.14–0.55) for dementia and 0.18 (0.07–0.48) for AD. The association between higher CR and reduced AD risk was significant in people aged 60–74 but not in those aged ≥75 years (p for interaction = 0.011). Similarly, among MCI-free people at baseline (n = 1,635), the high (vs. low) tertile of lifelong CR score was associated with multivariable-adjusted hazard ratios of 0.51 (0.38–0.69) for MCI and 0.46 (0.33–0.64) for amnestic MCI. Lifelong CR was not related to VaD or non-amnestic MCI. Discussion: High lifelong CR is associated with reduced risks of dementia and MCI, especially AD and amnestic MCI. It highlights the importance of lifelong CR in maintaining late-life cognitive health even among people with no or limited education.
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