Study on Wear Mechanism of Helical Gear by Three-Body Abrasive Based on Impact Load

This study aimed to explore the wear characteristics and evolution mechanisms of large-scale wind power gears under the impact load of particles of the three-body abrasive Al₂O₃ (0.2 mg/mL) from four aspects: oil analysis, vibration analysis, amount of gear wear, and tooth-surface-wear profile analysis. A magnetic powder brake was used to simulate the actual working conditions. Combined with the abrasive particle monitoring and the morphology analysis of the tooth-surface-wear scar, by setting quantitative hard particles in the lubricating oil, the gears are mainly operated in the abrasive wear state, and wear monitoring and wear degree analysis are carried out for the whole life cycle of the gears. Oil samples were observed and qualitatively analyzed using a particle counter, a single ferrograph, a metallographic microscope, and a scanning electron microscope. The experiments demonstrate that the initial hard particles have a greater impact in the early wear stage of the gears (<20 h), and abrasive particle concentration increases by 30%. This means that Al₂O₃ particles accelerate the gear wear during the running-in period. The loading method of the impact load on the oblique gear exacerbates the abrasion particle wear and expands the stress concentration, which reduces the surface of large milling particles on the surface, and reduces the width of the tooth (the part above the pitch line is severely worn), which causes the gear to break into failure. The research provides help for analyzing the mechanism of abrasive wear of gears and predicting wear life.     

小城镇及农村残疾人抑郁水平及相关因素的调查

目的:了解小城镇及农村残疾人的抑郁水平及其相关因素,为其居家照顾者减轻残疾人抑郁提供理论依据。方法:采用抑郁自评量表(SDS)、Barthel氏ADL指数量表、Procidana与Heller家庭支持量表及自行设计的一般资料问卷,对居住在小城镇及农村的63例残疾人进行问卷调查。结果:残疾人有抑郁症状的比例高达69.8%,残疾人抑郁水平与日常生活活动能力(ADL)及残疾人对其家庭照顾者照顾满意度呈负相关,有非常显著的统计学意义(P=0.000)。结论小城镇及农村残疾人的抑郁症状普遍较严重,社会应给予更多的关注,应大力发展社区护理,为有需要的残疾人上门服务,并加强对残疾人家庭照顾者的培训指导,以提高残疾人生活质量与心理健康水平。     

Dedifferentiated liposarcoma (DDLPS) in the rectum: A case report

Dedifferentiated liposarcoma (DDLPS) is a rare subtype of liposarcoma with a poor prognosis. This current case report describes a rectal DDLPS in a 68-year-old Chinese male that presented with lower abdominal pain and weight loss. Computed tomography and magnetic resonance imaging were undertaken to evaluate the tumour. The patient underwent radical resection of the rectal tumour, sigmoid colostomy and partial ureterectomy. The tumour was positive for mouse double minute 2 by immunohistochemistry. The patient healed well but refused chemotherapy postoperatively for economic reasons. The tumour recurred and metastasized 4 weeks after the operation. After relevant treatment, the patient''s condition deteriorated and he died of shock, metabolic acidosis, hyperlactataemia and acute renal failure. The case report also reviews the literature in terms of the clinical diagnosis, treatment and pathological characteristics of rectal DDLPS with the aim of improving the level of diagnosis and treatment.     

Preparation and characterization of pure phase CdMnTe nanopowders by a hydrothermal route

In this paper, CdMnTe nanopowders with uniform shapes were prepared through a facile hydrothermal route using 3-mercaptopropionic acid (MPA) as the stabilizer and modifier. The effects of different experimental conditions including Cd-to-MPA ratio, pH value and reaction temperature on the phase composition and formation mechanism of as-prepared nanopowders were studied. XRD results indicated as-prepared CdMnTe nanopowders were pure phase and had cubic sphalerite structure with high crystallinity. SEM and Rietveld refinement clearly showed that the powders were about 10–100 nm in size. In PL measurement, there was a strong luminescence peak in the infrared region 1.717–1.826 eV. Compared with the CdMnTe single crystal, a blue shift of about 0.109 eV indicated a wider band gap. In UV-vis spectra, the absorption peak of the sample blue shifted with the decrease of crystal size, which indicated an obvious quantum confinement effect (QCE) in nanopowders. The optimal conditions for the preparation of CdMnTe nanopowders are 180 °C for 24 h with the molar ratio 1 : 1 of Cd : MPA at pH 13. In particular, the growth kinetics and possible formation mechanism of the nanopowders were proposed.

CdMnTe high-quality and pure phase nanopowders, with diameters of 20 nm to 100 nm, were synthesized by a hydrothermal route using mercapto propionic acid as the stabilizer. A CdMnTe single crystal was produced by melting method and flash sintering using CdMnTe nanopowder.     

服务营销理念在无偿献血中应用的效果评价

目的探讨服务营销理念在无偿献血中的应用方法及效果。方法将服务营销的理念引入无偿献血护理工作中,包括无偿献血的宣传招募、献血全过程护理、献血后回访等方面,创新和优化献血服务。观察应用此理念后2006年1-10月无偿献血者献血反应发生情况、固定献血者人数以及一次性献血400m1人数,并与2005年同期进行比较,观察服务营销理念应用的效果。结果在无偿献血护理中引入服务营销理念后献血反应发生率由开展前的1．798％下降至0．499％;一次性献血400ml人数占献血者比例由14．878％增加至57．055％;固定献血者比例由3．448％增加到10．758％：两组比较差异均有统计学意义（P〈0．05或P〈0．01）。结论将服务营销的基本原理和方法运用于无偿献血护理工作中,可减少献血反应的发生率和降低献血反应的严重程度,并提高一次性献血400ml的人数,稳定和扩大固定无偿献血者队伍。     

The acquisition of cold sensitivity during TRPM8 ion channel evolution

To cope with temperature fluctuations, molecular thermosensors in animals play a pivotal role in accurately sensing ambient temperature. Transient receptor potential melastatin 8 (TRPM8) is the most established cold sensor. In order to understand how the evolutionary forces bestowed TRPM8 with cold sensitivity, insights into both emergence of cold sensing during evolution and the thermodynamic basis of cold activation are needed. Here, we show that the trpm8 gene evolved by forming and regulating two domains (MHR1-3 and pore domains), thus determining distinct cold-sensitive properties among vertebrate TRPM8 orthologs. The young trpm8 gene without function can be observed in the closest living relatives of tetrapods (lobe-finned fishes), while the mature MHR1-3 domain with independent cold sensitivity has formed in TRPM8s of amphibians and reptiles to enable channel activation by cold. Furthermore, positive selection in the TRPM8 pore domain that tuned the efficacy of cold activation appeared late among more advanced terrestrial tetrapods. Interestingly, the mature MHR1-3 domain is necessary for the regulatory mechanism of the pore domain in TRPM8 cold activation. Our results reveal the domain-based evolution for TRPM8 functions and suggest that the acquisition of cold sensitivity in TRPM8 facilitated terrestrial adaptation during the water-to-land transition.

Given that temperature influences all biological operations, the evolution of thermosensory adaptation is crucial in shaping the specialized temperature-dependent inhabitation of an organism. At the cellular level, thermosensory neurons in the dorsal root ganglia or trigeminal ganglia innervate the skin and transmit temperature information to the spinal cord and the brain. To bestow such neurons with thermal sensitivity, animals have a toolkit of temperature-sensitive ion channels located on the cell membrane at the molecular level. Accordingly, several members of the transient receptor potential (TRP) superfamily with steep thermosensitivity (referred to as thermoTRP) have attracted the general interest in the field of thermal biology, as they sufficiently cause steep changes in depolarizing currents upon either heating or cooling and thus are considered as the primary molecular sensors of temperature (1–4). Therefore, the evolutionary strategy for directly tuning the thermal activation in thermoTRPs can be employed by animals for their specialized thermosensory adaptation, as seen in vampire bats, pit-bearing snakes, platypus, penguins, squirrels, and camels (5–9).As heat sensation (warmth and extreme heat) provides the precondition of a fundamental and conserved biological survival process, the genes that encode heat sensors are considered ancient in many metazoan organisms. The annotation of trpv1 is consistently available in the genomes of fishes, insects, amphibians, reptiles, birds, and mammals. Despite the species-specific temperature-sensitive ranges, a growing number of studies have reported the functional convergence of these heat-sensitive thermoTRP orthologs at the protein level (10), suggesting the essential role of these channels in heat perception across species. Compared to heat sensors, the cold-sensitive thermoTRP likely evolved late. As the most established cold sensor responsive to low temperatures and cooling compounds, transient receptor potential melastatin 8 (TRPM8) was found in somatosensory neurons, and genetic ablation of trpm8 either in the neurons or mice led to a largely decreased cold sensitivity (4, 11–13). Interestingly, cold activation of amphibian TRPM8 has been tested (14), while sequencing efforts indicated the absence of the trpm8 gene in 12 fish species from 10 different orders (15). Several specific domains that may alter TRPM8 cold activation have been reported, including the pore domain, voltage sensing apparatus, and C terminus (8, 16–19). Notably, although the efficacy of cold activation is largely altered by residue substitutions in the pore domain, the channel mutants are still cold sensitive (8). Therefore, these findings based on domain/residue swapping among cold-sensitive TRPM8 orthologs may not draw an overall picture in functionally important domains responsible for cold sensitivity. How did the trpm8 gene originate? How did TRPM8 integrate and modulate cold sensitivity throughout evolution? The answers to such questions probably lead us to understand the evolution of temperature perception and identify the essential structural elements that shape TRPM8 cold activation.In this study, we show the presence of the young trpm8 gene in lobe-finned fishes, believed to be the ancestors that gave rise to all land vertebrates (20). Such a young type of trpm8 derived from the trpm2 exon shuffling was originated and formed during the expansion of lobe-finned fish genomes. By detecting the positive selection-rich domains, we described the formation of the thermosensitive MHR1-3 domain in amphibian and reptile species that enables TRPM8 to undergo conformational changes at low temperatures. Furthermore, we found that the TRPM8 pore domain of terrestrial vertebrates evolved to tune the efficacy of cold activation, in which a cold-sensitive MHR1-3 domain is indispensable to achieve such a modulatory mechanism. Together, our findings suggest that the trpm8 gene origination and formation of the TRPM8 MHR1-3 domain contributed to the transition of vertebrate life from water to land and that the efficacy of cold activation tuned by the TRPM8 pore domain diversified the setting of temperature-adaptive phenotypes in terrestrial vertebrates.     

Cell division control 42 elevates during infliximab therapy,and its increment relates to treatment response in ulcerative colitis patients

BackgroundCell division control 42 (CDC42) regulates multiple processes of inflammation and/or immunity in autoimmune diseases and also relates to the treatment efficacy of biologic regimens clinically. This study aimed to explore the longitudinal change in CDC42 during infliximab (IFX) treatment and its correlation with IFX response in ulcerative colitis (UC) patients.MethodsActive UC patients (N = 48) who received IFX were recruited, and their CDC42 expressions in peripheral blood mononuclear cells (PBMCs) were detected before treatment (W0) and at 12 weeks after treatment (W12) using RT‐qPCR. Also, CDC42 in PBMCs from UC patients with remission (N = 20) and health controls (HCs) (N = 20) were detected.ResultsCDC42 was reduced in active UC patients compared with UC patients with remission (p = 0.014) and HCs (p < 0.001). Besides, CDC42 was negatively correlated with CRP (p = 0.025), TNF‐α (p = 0.024), IL‐1β (p = 0.045), IL‐17A (p = 0.039), and Mayo score (p = 0.015) in active UC patients, but did not relate to ESR, disease duration, or IL‐6 (all p > 0.05), while CDC42 was only negatively related to CRP in UC patients with remission (p = 0.046). Interestingly, CDC42 was increased at W12 after IFX treatment in active UC patients (p < 0.001). Specifically, CDC42 was elevated during treatment in active UC patients with IFX response (p < 0.001), but did not obviously change in those without IFX response (p = 0.061). Furthermore, CDC42 at W12 was higher in active UC patients with IFX response compared with those without IFX response (p = 0.049).ConclusionCell division control 42 serves as a potential biomarker for monitoring disease progression and IFX response in UC patients.     

SLC2A3 variants in familial and sporadic congenital heart diseases in a Chinese Yunnan population

BackgroundSolute carrier family 2 member 3 (SLC2A3), is a member of a superfamily of transport protein genes. SLC2A3 played an important role in embryonic development. Previous research reported SLC2A3 duplication was reportedly associated with congenital syndromic heart defects. However, it is not clear whether the gene is associated with non‐syndromic congenital heart disease. Our study aimed to elucidate the relationship between its variation and congenital heart disease.MethodsGenomic DNA extracted from the peripheral blood leukocytes of two families with CHD were sequenced with whole‐exome sequencing to identify variations, used Sanger sequencing to investigate SLC2A3 variants in 494 Chinese patients with CHD and 576 healthy unrelated individuals.ResultsIn members from the two families, three with CHD had the SLC2A3 (rs3931701) C > T variant. Of the 494 patients with CHD, 394 had gene variants (86 had the TT type and 308 had the CT type). Of the 576 healthy controls, 272 participants had gene variants (36 had the TT type and 236 had the CT type). The TT type [p < 0.0001, odds ratio (OR) =7.262, 95% confidence interval (CI) =4.631–11.388] and CT type (p < 0.0001, OR =3.967, 95% CI =2.991–5.263) of SLC2A3 (rs3931701) significantly increased the risk of sporadic ASD in a Chinese Yunnan population.ConclusionsSingle nucleotide variations of SLC2A3, particularly, the SLC2A3 (rs3931701) C > T variant increased the risk of CHD among the studied population.     

Clinical Characteristics and Risk Factors for Mortality in Critical Coronavirus Disease 2019 Patients 50 Years of Age or Younger During the Delta Wave: Comparison With Patients > 50 Years in Korea

BackgroundNumerous patients around the globe are dying from coronavirus disease 2019 (COVID-19). While age is a known risk factor, risk analysis in the young generation is lacking. The present study aimed to evaluate the clinical features and mortality risk factors in younger patients (≤ 50 years) with a critical case of COVID-19 in comparison with those among older patients (> 50 years) in Korea.MethodsWe analyzed the data of adult patients only in critical condition (requiring high flow nasal cannula oxygen therapy or higher respiratory support) hospitalized with PCR-confirmed COVID-19 at 11 hospitals in Korea from July 1, 2021 to November 30, 2021 when the delta variant was a dominant strain. Patients’ electronic medical records were reviewed to identify clinical characteristics.ResultsDuring the study period, 448 patients were enrolled. One hundred and forty-two were aged 50 years or younger (the younger group), while 306 were above 50 years of age (the older group). The most common pre-existing conditions in the younger group were diabetes mellitus and hypertension, and 69.7% of the patients had a body mass index (BMI) > 25 kg/m². Of 142 younger patients, 31 of 142 patients (21.8%, 19 women) did not have these pre-existing conditions. The overall case fatality rate among severity cases was 21.0%, and it differed according to age: 5.6% (n = 8/142) in the younger group, 28.1% in the older group, and 38% in the ≥ 65 years group. Age (odds ratio [OR], 7.902; 95% confidence interval [CI], 2.754–18.181), mechanical ventilation therapy (OR, 17.233; 95% CI, 8.439–35.192), highest creatinine > 1.5 mg/dL (OR, 17.631; 95% CI, 8.321–37.357), and combined blood stream infection (OR, 7.092; 95% CI, 1.061–18.181) were identified as independent predictors of mortality in total patients. Similar patterns were observed in age-specific analyses, but most results were statistically insignificant in multivariate analysis due to the low number of deaths in the younger group. The full vaccination rate was very low among study population (13.6%), and only three patients were fully vaccinated, with none of the patients who died having been fully vaccinated in the younger group. Seven of eight patients who died had a pre-existing condition or were obese (BMI > 25 kg/m²), and the one remaining patient died from a secondary infection.ConclusionAbout 22% of the patients in the young critical group did not have an underlying disease or obesity, but the rate of obesity (BMI > 25 kg/m²) was high, with a fatality rate of 5.6%. The full vaccination rate was extremely low compared to the general population of the same age group, showing that non-vaccination has a grave impact on the progression of COVID-19 to a critical condition. The findings of this study highlight the need for measures to prevent critical progression of COVID-19, such as vaccinations and targeting young adults especially having risk factors.