Early introductions and transmission of SARS-CoV-2 variant B.1.1.7 in the United States.

The emergence and spread of SARS-CoV-2 lineage B.1.1.7, first detected in the United Kingdom, has become a global public health concern because of its increased transmissibility. Over 2,500 COVID-19 cases associated with this variant have been detected in the United States (US) since December 2020, but the extent of establishment is relatively unknown. Using travel, genomic, and diagnostic data, we highlight that the primary ports of entry for B.1.1.7 in the US were in New York, California, and Florida. Furthermore, we found evidence for many independent B.1.1.7 establishments starting in early December 2020, followed by interstate spread by the end of the month. Finally, we project that B.1.1.7 will be the dominant lineage in many states by mid- to late March. Thus, genomic surveillance for B.1.1.7 and other variants urgently needs to be enhanced to better inform the public health response.

Rynchopeterine inhibits the formation of hypertrophic scars by regulating the miR-21/HIF1AN axis.

Hypertrophic scar (HS) is a fibroproliferative skin disease characterized by abnormal wound healing and pathological excessive fibrosis of the skin. Currently, the molecular mechanism of the disease is still largely unknown, and there is no effective drug treatment. In this study, we explored the effect of Rynchopeterine on the formation of HS. HS fibroblasts (HSFs) were isolated from the HS tissues of patients recovering from severe burns. After treating HSFs with different concentrations of Rynchopeterine, CCK-8, EdU, and Annexin V-FITC/PI assays were used to detect the proliferation, apoptosis, and contractile ability of HSFs. RT-qPCR and Western blotting were performed to evaluate the effect of Rynchopeterine on the expression of miR-21 and hypoxia-inducible factor 1-alpha subunit suppressor (HIF1AN). The dual-luciferase reporter gene was used to verify the targeting relationship between miR-21 and HIF1AN. Rynchopeterine reduced the expression of Col1a2, Col3a1, and α-SMA, inhibited proliferation and contraction of HSFs, and increased apoptosis in a dose-dependent manner. miR-21 was highly expressed in HS tissues and HSFs, and Rynchopeterine could inhibit miR-21 expression. Overexpression of miR-21 and knockdown of HIF1AN increased proliferation, activation, contraction, and collagen synthesis of HSFs, and inhibited their apoptosis. In vivo, Rynchopeterine could reduce the collagen content of the dermis and the positive ratio of PCNA and α-SMA. Rynchopeterine is a good therapeutic agent for HS, which up-regulates the expression of HIF1AN by inhibiting miR-21, thereby inhibiting the formation of HS.

Strategic Lacunes Associated With Mild Cognitive Impairment in Rural Chinese Older Adults: A Population-Based Study.

BACKGROUND: Lacunes are associated with cognitive impairment. We sought to identify strategic lacune locations associated with mild cognitive impairment (MCI) and subtypes of MCI among older adults, and further to examine the role of white matter hyperintensities and perivascular spaces in the association. METHODS: This population-based cross-sectional study included 1230 dementia-free participants in the brain magnetic resonance imaging substudy (2018-2020) in MIND-China (Multimodal Interventions to Delay Dementia and Disability in Rural China). Lacunes were visually identified in frontal lobe, parieto-occipital lobe, temporal lobe, insula, basal ganglia, thalamus, cerebellum, and brainstem. MCI, amnestic MCI (aMCI), and nonamnestic MCI (naMCI) were defined following the Petersen's criteria. Data were analyzed using logistic regression models. RESULTS: Of the 1230 participants (age, ≥60 years; mean age, 69.40; SD, 4.30 years; 58.5% women), lacunes were detected in 357 people and MCI was defined in 286 individuals, including 243 with aMCI and 43 with naMCI. Lacunes in the supratentorial area, internal capsula, putamen/pallidum, and insula was significantly associated with increased odds ratio of MCI (multivariable-adjusted odds ratio ranged 1.40-3.21; P<0.05) and aMCI (multivariable-adjusted odds ratio ranged 1.46-3.36; P<0.05), whereas lacunes in the infratentorial area and brainstem were significantly associated with naMCI (multivariable-adjusted odds ratio ranged 2.68-3.46; P<0.01). Furthermore, the associations of lacunes in insula and internal capsula with MCI and aMCI, as well as the associations of lacunes in infratentorial area and brainstem with naMCI were present independent of white matter hyperintensities volume and perivascular spaces number. CONCLUSIONS: Lacunes in the internal capsula, putamen/pallidum, insula, and brainstem may represent the strategic lacunes that are independently associated with MCI, aMCI, or naMCI in Chinese older adults. REGISTRATION: URL: https://www.chictr.org.cn; Unique identifier: ChiCTR1800017758.

Evolving ω-amine transaminase AtATA guided by substrate-enzyme binding free energy for enhancing activity and stability against non-natural substrates.

In the field of chiral amine synthesis, ω-amine transaminase (ω-ATA) is one of the most established enzymes capable of asymmetric amination under optimal conditions. However, the applicability of ω-ATA toward more non-natural complex molecules remains limited due to its low transamination activity, thermostability, and narrow substrate scope. Here, by employing a combined approach of computational virtual screening strategy and combinatorial active-site saturation test/iterative saturation mutagenesis strategy, we have constructed the best variant M14C3-V5 (M14C3-V62A-V116S-E117I-L118I-V147F) with improved ω-ATA from Aspergillus terreus (AtATA) activity and thermostability toward non-natural substrate 1-acetylnaphthalene, which is the ketone precursor for producing the intermediate (R)-(+)-1-(1-naphthyl)ethylamine [(R)-NEA] of cinacalcet hydrochloride, showing activity enhancement of up to 3.4-fold compared to parent enzyme M14C3 (AtATA-F115L-M150C-H210N-M280C-V149A-L182F-L187F). The computational tools YASARA, Discovery Studio, Amber, and FoldX were applied for predicting mutation hotspots based on substrate-enzyme binding free energies and to show the possible mechanism with features related to AtATA structure, catalytic activity, and stability in silico analyses. M14C3-V5 achieved 71.8% conversion toward 50 mM 1-acetylnaphthalene in a 50 mL preparative-scale reaction for preparing (R)-NEA. Moreover, M14C3-V5 expanded the substrate scope toward aromatic ketone compounds. The generated virtual screening strategy based on the changes in binding free energies has successfully predicted the AtATA activity toward 1-acetylnaphthalene and related substrates. Together with experimental data, these approaches can serve as a gateway to explore desirable performances, expand enzyme-substrate scope, and accelerate biocatalysis.IMPORTANCEChiral amine is a crucial compound with many valuable applications. Their asymmetric synthesis employing ω-amine transaminases (ω-ATAs) is considered an attractive method. However, most ω-ATAs exhibit low activity and stability toward various non-natural substrates, which limits their industrial application. In this work, protein engineering strategy and computer-aided design are performed to evolve the activity and stability of ω-ATA from Aspergillus terreus toward non-natural substrates. After five rounds of mutations, the best variant, M14C3-V5, is obtained, showing better catalytic efficiency toward 1-acetylnaphthalene and higher thermostability than the original enzyme, M14C3. The robust combinational variant acquired displayed significant application value for pushing the asymmetric synthesis of aromatic chiral amines to a higher level.

The paravertebral lymphatic system is involved in the resorption of the herniated nucleus pulposus and the regression of inflammation associated with disc herniation.

OBJECTIVE: To investigate the role of the paravertebral lymphatic system in the nucleus pulposus herniation (NPH) resorption and the inflammation regression. DESIGN: Clinical specimens (n = 10) from patients with lumbar disc herniation (LDH) were collected, C57BL/6 (n = 84) and conditional Vegfr3 knockout mice (n = 14) were used. Immunofluorescence staining detected lymphatic vessels (LVs) and NP cells. Near-infrared imaging assessed lymphatic drainage function, and Alcian Blue/Orange determined inflammation. RESULTS: Lymphangiogenesis was observed in the herniated NP of patients with LDH, and the proportion of capillary LVs was higher than that of collecting LVs (mean 68.2% [95% confidence interval: 59.4, 77.1]). In NPH mice, NP cells were detected in paravertebral tissue (38.6 [32.0, 45.2]) and draining lymph nodes (dLN) at 4 h (76.9 [54.9, 98.8]). A significant increase of NP cells in dLNs was observed at 24 h (157.1 [113.7, 200.6]). Most of the herniated NP cells were cleared in paravertebral tissue after 1 week (7.5 [4.4, 10.6]), but disc inflammation peaked at 1 week (19.9% [14.7, 25.1]), along with persistent lymphangiogenesis (9.5 [7.2, 11.8]). However, conditional Vegfr3 knockout mice exhibited impaired lymphangiogenesis (5.7 [4.4, 7.0]) and herniated NP cell clearance (6.1 [1.8, 10.5]) during NPH, leading to exacerbated disc inflammation (23.7% [19.3, 28.2]). CONCLUSION: The paravertebral lymphatic system is involved in the NPH resorption and inflammation regression. Promoting lymphangiogenesis may be a novel strategy for facilitating NPH resorption and inflammation regression in patients with LDH.

Association of Triglyceride-Glucose Index With Cognitive Function and Brain Atrophy: A Population-Based Study.

OBJECTIVE: To investigate the associations of triglyceride-glucose (TyG) index, a reliable surrogate marker for insulin resistance, with the function of various cognitive domains and brain structures among older adults. DESIGN: A population-based cross-sectional study. SETTING: Older adults living in the rural communities in China. PARTICIPANTS: About 4,541 rural-dwelling dementia-free participants (age ≥65 years; 56.37% women) undertook examinations in March-September 2018 for MIND-China. MEASUREMENTS: TyG index was calculated as ln[fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. A neuropsychological test battery was used to assess memory, attention, verbal fluency, and executive function. Volumetric brain measures were assessed on magnetic resonance imaging (MRI) in a subsample (n = 1,019). Data were analyzed with restricted cubic spline and multivariable general linear models. RESULTS: An inverted J-shaped association was observed between TyG index and z-scores of multiple cognitive domains, such that among individuals with TyG index ≥8.57 (median), a higher TyG index was significantly associated with lower z-scores of memory, attention, verbal fluency, executive function, and global cognition (all p < 0.05); among people with TyG index <8.57, a higher TyG index was significantly associated with a higher executive function z-score (p < 0.05), but not with any of the other examined cognitive domains. In the MRI subsample, a higher TyG index was significantly associated with lower volumes of total brain tissue, gray matter, and white matter as well as greater cerebrospinal fluid volume (p < 0.05), but not with white matter hyperintensity volume. CONCLUSIONS: Insulin resistance, as indicated by a high TyG index, was associated with poor function in multiple cognitive domains and global brain atrophy.

Association of dementia with impaired kidney function and plasma biomarkers: A population-based study.

BACKGROUND AND PURPOSE: Emerging evidence has linked impaired kidney function with dementia in older adults, but the neuropathological pathways underlying their association remain poorly understood. We sought to examine the relationships of kidney function with dementia and plasma biomarkers in a Chinese rural population. METHODS: This population-based study used data from the baseline examination of the Multimodal Interventions to Delay Dementia and Disability in rural China (MIND-China) cohort (March-September 2018; n = 5715). Kidney function was assessed using estimated glomerular filtration rate (eGFR) based on serum creatinine level. Dementia, Alzheimer's disease (AD) and vascular dementia (VaD) were diagnosed according to the international criteria. Plasma biomarkers were measured using the SIMOA platform in a subsample (n = 1446). Data were analyzed using logistic, general linear, and mediation models. RESULTS: Of the 5715 participants, 306 were diagnosed with dementia, including 195 with AD and 100 with VaD. Impaired kidney function (eGFR <60 vs. ≥90 mL/min/1.73 m2) was associated with multivariable-adjusted odds ratios of 2.24 (95% confidence interval [CI] 1.44-3.46) for all-cause dementia, 1.85 (1.07-3.18) for AD, and 2.49 (1.16-5.22) for VaD. In the biomarker subsample, impaired kidney function was significantly associated with higher plasma amyloid-ß (Aß)40 (ß-coefficient = 54.36, 95% CI 43.34-65.39), Aß42 (ß-coefficient = 3.14, 95% CI 2.42-3.86), neurofilament light chain (ß-coefficient = 10.62, 95% CI 5.62-15.62), and total tau (ß-coefficient = 0.68, 95% CI 0.44-0.91), and a lower Aß42/Aß40 ratio (ß-coefficient = -4.11, 95% CI -8.08 to -0.14). The mediation analysis showed that plasma total tau significantly mediated 21.76% of the association between impaired kidney function and AD (p < 0.05). CONCLUSION: Impaired kidney function is associated with dementia and plasma biomarkers among rural-dwelling older Chinese adults, and the association with AD is partly mediated by plasma biomarkers for neurodegeneration.

Integrated proteomic and metabolomic profiling of lymph after trauma-induced hypercoagulopathy and antithrombotic therapy.

BACKGROUND: Routine coagulation tests are not widely accepted diagnostic criteria of trauma-induced hypercoagulopathy (TIH) due to insensitivity. Lymphatic vessels drain approximately 10% of the interstitial fluid into the lymphatic system and form lymph. SUBJECTIVE: The purpose of this study was to identify the potential lymph biomarkers for TIH. METHODS: Eighteen male Sprague-Dawley rats were randomly assigned to the sham (non-fractured rats with sham surgery and vehicle treatment), the VEH (fractured rats with vehicle treatment) and the CLO (fractured rats with clopidogrel treatment) group. Thoracic duct lymph was obtained to perform proteomics and untargeted metabolomics. RESULTS: A total of 1207 proteins and 16,695 metabolites were identified. The top 5 GO terms of lymph proteomics indicated that oxidative stress and innate immunity were closely associated with TIH and antithrombotic therapy. The top 5 GO terms of lymph metabolomics showed that homocystine and lysophosphatidylcholine were the differential expressed metabolites (DEMs) between the sham and VEH groups, while cholic acid, docosahexaenoic acid, N1-Methyl-2-pyridone-5-carboxamide, isoleucine and testosterone are the DEMs between the VEH and CLO group. CONCLUSIONS: This study presents the first proteomic and metabolomic profiling of lymph after TIH and antithrombotic therapy, and predicts the possible lymph biomarkers for TIH.

Thalamic gray matter volume mediates the association between KIBRA polymorphism and olfactory function among older adults: a population-based study.

The kidney and brain expressed protein (KIBRA) rs17070145 polymorphism is associated with both structure and activation of the olfactory cortex. However, no studies have thus far examined whether KIBRA can be linked with olfactory function and whether brain structure plays any role in the association. We addressed these questions in a population-based cross-sectional study among rural-dwelling older adults. This study included 1087 participants derived from the Multidomain Interventions to Delay Dementia and Disability in Rural China, who underwent the brain MRI scans in August 2018 to October 2020; of these, 1016 took the 16-item Sniffin' Sticks identification test and 634 (62.40%) were defined with olfactory impairment (OI). Data were analyzed using the voxel-based morphometry analysis and general linear, logistic, and structural equation models. The KIBRA rs17070145 C-allele (CC or CT vs. TT genotype) was significantly associated with greater gray matter volume (GMV) mainly in the bilateral orbitofrontal cortex and left thalamus (P < 0.05) and with the multi-adjusted odds ratio of 0.73 (95% confidence interval 0.56-0.95) for OI. The left thalamic GMV could mediate 8.08% of the KIBRA-olfaction association (P < 0.05). These data suggest that the KIBRA rs17070145 C-allele is associated with a reduced likelihood of OI among older adults, partly mediated through left thalamic GMV.

Prevalence and associated factors of excessive daytime sleepiness in rural older adults: a population-based study.

OBJECTIVE: To investigate the prevalence and associated factors of excessive daytime sleepiness (EDS) among rural-dwelling Chinese older adults. METHODS: We collected data on demographic, epidemiological, and clinical factors via in-person interviews and clinical examinations following a structured questionnaire. The 15-item Geriatric Depression Scale (GDS-15) was used to assess depressive symptoms, the Berlin questionnaire (BQ) to assess obstructive sleep apnea (OSA) risk; and the Epworth Sleepiness Scale (ESS) to assess sleep characteristics. EDS was defined as the total ESS score > 10. RESULTS: This population-based study engaged 4845 participants (age ≥ 65 years, 57.3% female) in the 2018 examination of the Multimodal Interventions to Delay Dementia and Disability in Rural China. The prevalence of EDS was 9.3% in the total sample, 8.3% in females, and 10.6% in males, and the prevalence decreased with advanced age. Logistic regression analysis revealed that EDS was significantly associated with age (multivariable-adjusted odds ratio [OR] = 0.97; 95% confidence interval [CI] 0.95-0.99), female sex (0.53; 0.36-0.77), hypertension (0.68; 0.54-0.85), depressive symptoms (2.68; 2.07-3.46), high OSA risk (2.11; 1.69-2.63), and poor sleep quality (2.12; 1.60-2.82). CONCLUSION: EDS affects nearly one-tenth of rural older adults in China. Older age, female sex, and hypertension were associated with a decreased likelihood of EDS, while depressive symptoms, high OSA risk, and poor sleep quality were correlated with an elevated likelihood of EDS.

Associations of 24-hour movement behaviors with depressive symptoms in rural-dwelling older adults: a compositional data analysis.

BACKGROUND: We aimed to explore the association of sleep duration with depressive symptoms among rural-dwelling older adults in China, and to estimate the impact of substituting sleep with sedentary behavior (SB) and physical activity (PA) on the association with depressive symptoms. METHODS: This population-based cross-sectional study included 2001 rural-dwelling older adults (age ≥ 60 years, 59.2% female). Sleep duration was assessed using the Pittsburgh Sleep Quality Index. We used accelerometers to assess SB and PA, and the 15-item Geriatric Depression Scale to assess depressive symptoms. Data were analyzed using restricted cubic splines, compositional logistic regression, and isotemporal substitution models. RESULTS: Restricted cubic spline curves showed a U-shaped association between daily sleep duration and the likelihood of depressive symptoms (P-nonlinear < 0.001). Among older adults with sleep duration < 7 h/day, reallocating 60 min/day spent on SB and PA to sleep were associated with multivariable-adjusted odds ratio (OR) of 0.81 (95% confidence interval [CI] = 0.78-0.84) and 0.79 (0.76-0.82), respectively, for depressive symptoms. Among older adults with sleep duration ≥ 7 h/day, reallocating 60 min/day spent in sleep to SB and PA, and reallocating 60 min/day spent on SB to PA were associated with multivariable-adjusted OR of 0.78 (0.74-0.84), 0.73 (0.69-0.78), and 0.94 (0.92-0.96), respectively, for depressive symptoms. CONCLUSIONS: Our study reveals a U-shaped association of sleep duration with depressive symptoms in rural older adults and further shows that replacing SB and PA with sleep or vice versa is associated with reduced likelihoods of depressive symptoms depending on sleep duration.

Overexpression of a nuclear receptor HR96 contributes to spirodiclofen susceptibility in Panonychus citri (McGregor).

The citrus red mite, Panonychus citri, is one of the most notorious and devastating citrus pests around the world that has developed resistance to multiple chemical acaricides. In previous research, we found that spirodiclofen-resistant is related to overexpression of P450, CCE, and ABC transporter genes in P. citri. However, the regulatory mechanisms of these detoxification genes are still elusive. This study identified all hormone receptor 96 genes of P. citri. 8 PcHR96 genes contained highly conserved domains. The expression profiles showed that PcHR96h was significantly upregulated in spirodiclofen resistant strain and after exposure to spirodiclofen. RNA interference of PcHR96h decreased expression of detoxification genes and increased spirodiclofen susceptibility in P. citri. Furthermore, molecular docking, heterologous expression, and drug affinity responsive target stability demonstrated that PcHR96h can interact with spirodiclofen in vitro. Our research results indicate that PcHR96h plays an important role in regulating spirodiclofen susceptibility and provides theoretical support for the resistance management of P. citri.

Cationic proteins from eosinophils bind bone morphogenetic protein receptors promoting vascular calcification and atherogenesis.

AIMS: Blood eosinophil count and eosinophil cationic protein (ECP) concentration are risk factors of cardiovascular diseases. This study tested whether and how eosinophils and ECP contribute to vascular calcification and atherogenesis. METHODS AND RESULTS: Immunostaining revealed eosinophil accumulation in human and mouse atherosclerotic lesions. Eosinophil deficiency in ΔdblGATA mice slowed atherogenesis with increased lesion smooth muscle cell (SMC) content and reduced calcification. This protection in ΔdblGATA mice was muted when mice received donor eosinophils from wild-type (WT), Il4-/-, and Il13-/- mice or mouse eosinophil-associated-ribonuclease-1 (mEar1), a murine homologue of ECP. Eosinophils or mEar1 but not interleukin (IL) 4 or IL13 increased the calcification of SMC from WT mice but not those from Runt-related transcription factor-2 (Runx2) knockout mice. Immunoblot analyses showed that eosinophils and mEar1 activated Smad-1/5/8 but did not affect Smad-2/3 activation or expression of bone morphogenetic protein receptors (BMPR-1A/1B/2) or transforming growth factor (TGF)-ß receptors (TGFBR1/2) in SMC from WT and Runx2 knockout mice. Immunoprecipitation showed that mEar1 formed immune complexes with BMPR-1A/1B but not TGFBR1/2. Immunofluorescence double-staining, ligand binding, and Scatchard plot analysis demonstrated that mEar1 bound to BMPR-1A and BMPR-1B with similar affinity. Likewise, human ECP and eosinophil-derived neurotoxin (EDN) also bound to BMPR-1A/1B on human vascular SMC and promoted SMC osteogenic differentiation. In a cohort of 5864 men from the Danish Cardiovascular Screening trial and its subpopulation of 394 participants, blood eosinophil counts and ECP levels correlated with the calcification scores of different arterial segments from coronary arteries to iliac arteries. CONCLUSION: Eosinophils release cationic proteins that can promote SMC calcification and atherogenesis using the BMPR-1A/1B-Smad-1/5/8-Runx2 signalling pathway.

Channel Features and API Frequency-Based Transformer Model for Malware Identification.

Malicious software (malware), in various forms and variants, continues to pose significant threats to user information security. Researchers have identified the effectiveness of utilizing API call sequences to identify malware. However, the evasion techniques employed by malware, such as obfuscation and complex API call sequences, challenge existing detection methods. This research addresses this issue by introducing CAFTrans, a novel transformer-based model for malware detection. We enhance the traditional transformer encoder with a one-dimensional channel attention module (1D-CAM) to improve the correlation between API call vector features, thereby enhancing feature embedding. A word frequency reinforcement module is also implemented to refine API features by preserving low-frequency API features. To capture subtle relationships between APIs and achieve more accurate identification of features for different types of malware, we leverage convolutional neural networks (CNNs) and long short-term memory (LSTM) networks. Experimental results demonstrate the effectiveness of CAFTrans, achieving state-of-the-art performance on the mal-api-2019 dataset with an F1 score of 0.65252 and an AUC of 0.8913. The findings suggest that CAFTrans improves accuracy in distinguishing between various types of malware and exhibits enhanced recognition capabilities for unknown samples and adversarial attacks.

Association of polygenic risk scores with Alzheimer's disease and plasma biomarkers among Chinese older adults: A community-based study.

INTRODUCTION: We examined the associations of polygenic risk score (PRS) with Alzheimer's disease (AD) and plasma biomarkers in the Chinese population. METHODS: This population-based study used baseline data from MIND-China (2018; n = 4873) and follow-up data from dementia-free individuals (2014-2018; n = 2117). We measured AD-related plasma biomarkers in a subsample (n = 1256). Data were analyzed using logistic and Cox regression models. RESULTS: We developed PRS with (PRSAPOE) and without (PRSnon- APOE) apolipoprotein E (APOE) gene. In the longitudinal analysis, PRSAPOE was associated with a multivariable-adjusted hazards ratio of 1.91 (95% CI = 1.13-3.23) for AD. PRSAPOE in combination with demographics yielded discriminative (area under the curve [AUC]) and predictive(C-statistic) accuracy of 0.80 (95% confidence interval [CI] = 0.77-0.84) and 0.80 (0.77-0.82), respectively. PRSnon- APOE showed an association with AD risk similar to PRSAPOE. PRSAPOE, but not PRSnon- APOE, was associated with reduced plasma Aß42/Aß40 ratio and increased Neurofilament light chain (NfL) (p < 0.05). DISCUSSION: The PRS with and without APOE gene, in combination with demographics, shows good discriminative and predictive ability for AD. The AD-related pathologies underlie AD risk associated with PRSAPOE. HIGHLIGHTS: The PRSAPOE and PRSnon- APOE were associated with AD risk in the Chinese population. The PRSAPOE and PRSnon- APOE, in combination with demographics, showed good discriminative and predictive ability for AD. The AD-related pathologies underlie the AD risk associated with PRSAPOE but not PRSnon- APOE.

Multimorbidity, cognitive phenotypes, and Alzheimer's disease plasma biomarkers in older adults: A population-based study.

INTRODUCTION: To examine the burden and clusters of multimorbidity in association with mild cognitive impairment (MCI), dementia, and Alzheimer's disease (AD)-related plasma biomarkers among older adults. METHODS: This population-based study included 5432 participants (age ≥60 years); of these, plasma amyloid beta (Aß), total tau, and neurofilament light chain (NfL) were measured in a subsample (n = 1412). We used hierarchical clustering to generate five multimorbidity clusters from 23 chronic diseases. We diagnosed dementia and MCI following international criteria. Data were analyzed using logistic and linear regression models. RESULTS: The number of chronic diseases was associated with dementia (multivariable-adjusted odds ratio = 1.22; 95% confidence interval [CI] = 1.11 to 1.33), AD (1.13; 1.01 to 1.26), vascular dementia (VaD) (1.44; 1.25 to 1.64), and non-amnestic MCI (1.25; 1.13 to 1.37). Metabolic cluster was associated with VaD and non-amnestic MCI, whereas degenerative ocular cluster was associated with AD (p < 0.05). The number of chronic diseases was associated with increased plasma Aß and NfL (p < 0.05). DISCUSSION: Multimorbidity burden and clusters are differentially associated with subtypes of dementia and MCI and AD-related plasma biomarkers in older adults. HIGHLIGHTS: We used hierarchical clustering to generate five clusters of multimorbidity. The presence and load of multimorbidity were associated with dementia and mild cognitive impairment. Multimorbidity clusters were differentially associated with subtypes of dementia and Alzheimer's disease plasma biomarkers.

Cardiometabolic multimorbidity, peripheral biomarkers, and dementia in rural older adults: The MIND-China study.

INTRODUCTION: Evidence has emerged that cardiometabolic multimorbidity (CMM) is associated with dementia, but the underlying mechanisms are poorly understood. METHODS: This population-based study included 5704 older adults. Of these, data were available in 1439 persons for plasma amyloid-ß (Aß), total tau, and neurofilament light chain (NfL) and in 1809 persons for serum cytokines. We defined CMM following two common definitions used in previous studies. Data were analyzed using general linear, logistic, and mediation models. RESULTS: The presence of CMM was significantly associated with an increased likelihood of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) (p < 0.05). CMM was significantly associated with increased plasma Aß40, Aß42, and NfL, whereas CMM that included visceral obesity was associated with increased serum cytokines. The mediation analysis suggested that plasma NfL significantly mediated the association of CMM with AD. DISCUSSION: CMM is associated with dementia, AD, and VaD in older adults. The neurodegenerative pathway is involved in the association of CMM with AD. HIGHLIGHTS: The presence of CMM was associated with increased likelihoods of dementia, AD, and VaD in older adults. CMM was associated with increased AD-related plasma biomarkers and serum inflammatory cytokines. Neurodegenerative pathway was partly involved in the association of CMM with AD.

Synergistic associations of CD33 variants and hypertension with brain and cognitive aging among dementia-free older adults: A population-based study.

INTRODUCTION: CD33 rs3865444 and hypertension (HTN) are related to cognitive impairment, individually. However, little is known about their combined effects on cognitive function in older adults. METHODS: This population-based study included 4368 dementia-free participants (age ≥65 years) in the Multimodal Interventions to Delay Dementia and Disability in Rural China (MIND-China), with data available in 1044 persons for gray matter volume and 85 persons for cerebral blood flow (CBF). We used general linear regression and mediation models to examine the associations of rs3865444 and HTN with cognition, brain atrophy, and CBF. RESULTS: Among rs3865444 CC carriers, HTN and late-life HTN were significantly associated with impaired cognition. Midlife and late-life HTN were correlated with brain atrophy. CD33 rs3865444 CC moderated the mediation effect of gray matter volume on the association between HTN and global cognition. HTN was correlated with low CBF in rs3865444 CC carriers. DISCUSSION: There are synergistic associations of CD33 rs3865444 and HTN with brain and cognitive aging in dementia-free older adults.

Development and validation of an assessment index for quantifying cognitive task load in pilots under simulated flight conditions using heart rate variability and principal component analysis.

To investigate whether high cognitive task load (CTL) for aircraft pilots can be identified by analysing heart-rate variability, electrocardiograms were recorded while cadet pilots (n = 68) performed the plane tracking, anti-gravity pedalling, and reaction tasks during simulated flight missions. Data for standard electrocardiogram parameters were extracted from the R-R-interval series. In the research phase, low frequency power (LF), high frequency power (HF), normalised HF, and LF/HF differed significantly between high and low CTL conditions (p < .05 for all). A principal component analysis identified three components contributing 90.62% of cumulative heart-rate variance. These principal components were incorporated into a composite index. Validation in a separate group of cadet pilots (n = 139) under similar conditions showed that the index value significantly increased with increasing CTL (p < .05). The heart-rate variability index can be used to objectively identify high CTL flight conditions.Practitioner summary: We used principal component analysis of electrocardiogram data to construct a composite index for identifying high cognitive task load in pilots during simulated flight. We validated the index in a separate group of pilots under similar conditions. The index can be used to improve cadet training and flight safety.Abbreviations: ANOVA: a one-way analysis of variance; AP: anti-gravity pedaling task; CTL: cognitive task load; ECG: electrocardiograms; HR: heart rate; HRV: heart-rate variability; HRVI: heart-rate variability index; PT: plane-tracking task; RMSSD: root-mean square of differences between consecutive R-R intervals; RT: reaction task; SDNN: standard deviation of R-R intervals; HF: high frequency power; HFnu: normalized HF; LF: low frequency power; LFnu: normalized LF; PCA: principal component analysis.

Association of Accelerometer-Measured Sedentary Behavior Patterns With Nonalcoholic Fatty Liver Disease Among Older Adults: The MIND-China Study.

INTRODUCTION: The relationships between sedentary behavior patterns and nonalcoholic fatty liver disease (NAFLD) in older adults are not well investigated. METHODS: This population-based study included 1,899 rural-dwelling adults (aged 60 years or older). We assessed sedentary parameters with ActiGraph and defined NAFLD using ultrasonography. RESULTS: Long total and prolonged sedentary time were associated with increased likelihoods of NAFLD, whereas engaging more breaks per sedentary hour and reallocating sedentary time to light-intensity physical activity were associated with reduced likelihoods of NAFLD (P linear <0.05). DISCUSSION: Shorter sedentary time, engaging more frequent breaks in sedentary behavior, and replacing sedentary time with physical activity are associated with reduced likelihoods of NAFLD in older adults.