52 research outputs found
Non-contact magnetic driving bioinspired Venus flytrap robot based on bistable anti-symmetric CFRP structure
The Venus flytrap takes advantage of its bistability to generate rapid closure motion for capturing its prey. A bioinspired Venus flytrap robot with bistable artificial leaves is presented in this paper. Non-contact electromagnetic driving method is proposed to actuate the Venus flytrap robot's artificial leaves, which are made of anti-symmetric carbon fiber reinforced prepreg (CFRP) cylindrical shells. Magnetic force is generated by using the electromagnet and applied on the shell's curve edge to unbend the shell, and then the bending process transmits from one edge to the whole surface. The required magnetic force for the snap-through process of the bistable CFRP structure is determined from experimental test and compared with the result of finite element simulation. The test of the snap-through process of the Venus flytrap robot show that the Venus flytrap robot can generate a rapid snapping motion by the electromagnet actuation
Thermal effect and active control on bistable behaviour of anti-symmetric composite shells with temperature-dependent properties
Anti-symmetric cylindrical shells with two stable configurations have been proved to offer novel morphing structures in advanced engineering fields. The bistable behaviour of anti-symmetric composite shells under thermomechanical loading is analysed herein theoretically combined with a finite element modelling. The properties of the composite material in current study are considered to be functions of temperature. The shell is subjected to two different thermal load, i.e. the uniform temperature field and through-thickness thermal gradient. The influence of this two temperature field on the shell’s stable shapes was predicted analytically, which thereafter is determined by finite element results. This provides a feasible approach of controlling the deformation of the bistable shell through adjusting the applied temperature field. For this purpose, a superposition of uniform temperature field and through-thickness thermal gradient is imposed and its influence on the bistable shapes of bistable shells is therefore investigated, which is of great importance to the design and application of morphing structures manufactured from bistable composite shells
The genetic determinants of recurrent somatic mutations in 43,693 blood genomes
Nononcogenic somatic mutations are thought to be uncommon and inconsequential. To test this, we analyzed 43,693 National Heart, Lung and Blood Institute Trans-Omics for Precision Medicine blood whole genomes from 37 cohorts and identified 7131 non-missense somatic mutations that are recurrently mutated in at least 50 individuals. These recurrent non-missense somatic mutations (RNMSMs) are not clearly explained by other clonal phenomena such as clonal hematopoiesis. RNMSM prevalence increased with age, with an average 50-year-old having 27 RNMSMs. Inherited germline variation associated with RNMSM acquisition. These variants were found in genes involved in adaptive immune function, proinflammatory cytokine production, and lymphoid lineage commitment. In addition, the presence of eight specific RNMSMs associated with blood cell traits at effect sizes comparable to Mendelian genetic mutations. Overall, we found that somatic mutations in blood are an unexpectedly common phenomenon with ancestry-specific determinants and human health consequences
Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD
Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group
A multimodal cell census and atlas of the mammalian primary motor cortex
ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties
Relationship between the NF-κB1-94ins/del ATTG locus polymorphism and risk of hypertension in the Chinese Han population
Objective: The onset of essential hypertension is the result of a combination of genetic factors and the environment. The nuclear factor (NF)-κB1-94ins/del ATTG locus polymorphism is associated with the occurrence of various diseases. The purpose of this study was to find out the relationship between the NF-κB1-94ins/del ATTG locus polymorphism and the risk of hypertension in the Chinese Han population. Methods: A total of 585 Chinese Han patients with essential hypertension and 585 Chinese Han healthy volunteers were recruited. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to analyze the genotype of the NF-κB1-94ins/del ATTG locus in all the subjects. Results: For the NF-κB1-94ins/del ATTG locus, the dominant (adjusted odds ratio [OR] = 1.31, 95% confidence interval [CI] = 1.13–1.54, P < 0.001), recessive (adjusted OR = 1.17, 95% CI = 1.02–1.32, P = 0.03) and additive (adjusted OR = 1.19, 95% CI = 1.03–1.36, P = 0.01) models showed significant increase in the risk of hypertension. The NF-κB1-94ins/del ATTG locus II genotype was an independent risk factor for hypertension (OR = 1.15, 95% CI = 0.78–1.69, P = 0.02). The interaction between the NF-κB1-94ins/del ATTG locus polymorphism and BMI, alcohol consumption, and diabetes significantly increased the risk of hypertension (OR = 1.71, 95% CI = 1.26–1.86, P < 0.01). Conclusion: The NF-κB1-94ins/del ATTG polymorphism is an independent risk factor for essential hypertension. The NF-κB1-94ins/del ATTG locus, obesity, drinking, and diabetes also interact to yield a higher risk of hypertension
Use telehealth as needed: telehealth substitutes in-person primary care and associates with the changes in unplanned events and follow-up visits
Abstract Background Telehealth rapidly expanded since the outbreak of the COVID-19 pandemic. This study aims to understand how telehealth can substitute in-person services by 1) estimating the changes in non-COVID emergency department (ED) visits, hospitalizations, and care costs among US Medicare beneficiaries by visit modality (telehealth vs. in-person) during the COVID-19 pandemic relative to the previous year; 2) comparing the follow-up time and patterns between telehealth and in-person care. Methods A retrospective and longitudinal study design using US Medicare patients 65 years or older from an Accountable Care Organization (ACO). The study period was April-December 2020, and the baseline period was March 2019 – February 2020. The sample included 16,222 patients, 338,872 patient-month records and 134,375 outpatient encounters. Patients were categorized as non-users, telehealth only, in-person care only and users of both types. Outcomes included the number of unplanned events and costs per month at the patient level; number of days until the next visit and whether the next visit happened within 3-, 7-, 14- and 30-days at the encounter level. All analyses were adjusted for patient characteristics and seasonal trends. Results Beneficiaries who used only telehealth or in-person care had comparable baseline health conditions but were healthier than those who used both types of services. During the study period, the telehealth only group had significantly fewer ED visits/hospitalizations and lower Medicare payments than the baseline (ED 13.2, 95% CI [11.6, 14.7] vs. 24.6 per 1,000 patients per month and hospitalization 8.1 [6.7, 9.4] vs. 12.7); the in-person only group had significantly fewer ED visits (21.9 [20.3, 23.5] vs. 26.1) and lower Medicare payments, but not hospitalizations; the both-types group had significantly more hospitalizations (23.0 [21.4, 24.6] vs. 17.8). Telehealth was not significantly different from in-person encounters in number of days until the next visit (33.4 vs. 31.2 days) or the probabilities of 3- and 7-day follow-up visits (9.2 vs. 9.3% and 21.8 vs.23.5%). Conclusions Patients and providers treated telehealth and in-person visits as substitutes and used either depending on medical needs and availability. Telehealth did not lead to sooner or more follow-up visits than in-person services
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