Nonlinear modelling and transient dynamics analysis of a hoist equipped with a two-stage planetary gear transmission system

A system-level nonlinear dynamic model for a two-stage planetary gear transmission system of a hoist is established with the consideration of time-varying meshing stiffness, backlash, damping, and bearing stiffness. Vibrational test results are also presented in accordance with simulation results computed from the dynamic model, and engagement-impacting dynamic simulations are achieved by adapting a dynamic explicit algorithm based on this model. Accordingly, variation in the contact state in relation to the engaging position is obtained together with vibration characteristics of the transmission system. This study provides a theoretical basis for the reduction of vibration and noise for the transmission system

Case Report: A Clinical and Genetic Analysis of Childhood Growth Hormone Deficiency With Familial Hypercholesterolemia

BackgroundGrowth hormone deficiency (GHD) is a developmental disorder in children characterized by low growth hormone (GH), short stature and unfavorable lipid profiles. Familial hypercholesteremia (FH) is an inborn disorder of low-density lipoprotein cholesterol (LDL-C) metabolism which results in premature cardiovascular events. The co-occurrence of GHD and FH, which may aggravate the hypercholesteremic condition in the affected individuals, had rarely been discussed in previous publication.MethodsThis work reports two cases of GHD with FH, and explores the lipid profiles of GHD children and their therapeutic response to recombinant human growth hormone (rhGH). The diagnosis of GHD is based on low peak GH level (<7 ng/mL) in GH provocation test. FH is diagnosed by high LDL-C level (≥ 4 mmol/L) and confirmed genetic mutations in the LDL-C metabolic pathway. We also searched all previously published metabolic studies on GHD children as of December 31, 2020. Information on their LDL-C, duration and dose of rhGH treatment were retrieved and summarized.ResultsThe first case was a 5.3 year-old boy. His height was 103.6 cm (SDS = -2.29) and his peak GH in provocative test was 6.37 ng/mL. Additionally, his LDL-C was 4.80 mmol/L and he harbored a heterozygous mutation for the apolipoprotein B (APOB) gene (c.10579 C > T). The second case was a 9-year-old girl at the height of 117.3 cm (SDS = -2.91). Her GH peaked at 4.99 ng/mL in insulin-induced hypoglycemic test and 2.80 ng/mL in L-dopa test. Her LDL-C was 6.16 mmol/L, and she carried a mutated copy of the low-density lipoprotein receptor (LDLR) gene (c.809 G > A). Literature review indicated that GHD children suffered from higher baseline LDL-C, but it was significantly reduced after rhGH treatment.ConclusionsFH should be considered if a GHD child has remarkably elevated LDL-C that cannot be attributed to low GH level alone. Genetic mutations in the LDL-C metabolic pathway prevent the body from effectively metabolizing lipids, thereby resulting in early-onset hypercholesteremia and probably playing a negative role in children’s growth

In situ Chromatin Interaction Analysis Using Paired-End Tag Sequencing.

Chromatin Interaction Analysis Using Paired-End Tag Sequencing (ChIA-PET) is an established method to map protein-mediated chromatin interactions. A limitation, however, is that it requires a hundred million cells per experiment, which hampers its broad application in biomedical research, particularly in studies in which it is impractical to obtain a large number of cells from rare samples. To reduce the required input cell number while retaining high data quality, we developed an in situ ChIA-PET protocol, which requires as few as 1 million cells. Here, we describe detailed step-by-step procedures for performing in situ ChIA-PET from cultured cells, including both an experimental protocol for sample preparation and data generation and a computational protocol for data processing and visualization using the ChIA-PIPE pipeline. As the protocol significantly simplifies the experimental procedure, reduces ligation noise, and decreases the required input of cells compared to previous versions of ChIA-PET protocols, it can be applied to generate high-resolution chromatin contact maps mediated by various protein factors for a wide range of human and mouse primary cells. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Sample preparation and data generation Support Protocol: Bridge linker preparation Basic Protocol 2: Data processing and visualization

Genomes shed light on the evolution of Begonia, a mega‐diverse genus

Clarifying the evolutionary processes underlying species diversification and adaptation is a key focus of evolutionary biology. Begonia (Begoniaceae) is one of the most species-rich angiosperm genera with ~2,000 species, most of which are shade-adapted. Here, we present chromosome-scale genome assemblies for four species of Begonia (B. loranthoides, B. masoniana, B. darthvaderiana, and B. peltatifolia), and whole genome shot-gun data for an additional 74 Begonia representatives to investigate lineage evolution and shade adaptation of the genus. The four genome assemblies range in size from 331.75 Mb (B. peltatifolia) to 799.83 Mb (B. masoniana), and harbor 22,059 - 23,444 protein-coding genes. Synteny analysis revealed a lineage specific whole-genome duplication (WGD) that occurred just before the diversification of the Begonia. Functional enrichment of gene families retained after WGD highlight the significance of modified carbohydrate metabolism and photosynthesis possibly linked to shade-adaptation in the genus, which is further supported by expansions of gene families involved in light perception and harvesting. Phylogenomic reconstructions and genomics studies indicate that genomic introgression has also played a role in the evolution of Begonia. Overall, this study provides valuable genomic resources for Begonia and suggests potential drivers underlying the diversity and adaptive evolution of this mega-diverse clade