添加剂及纳米WC粉含量对电镀WC-Cu复合材料性能的影响

研究添加剂(聚乙二醇(PEG)、十二烷基硫酸钠(SDS))和纳米WC粉对WC-Cu复合材料显微结构、相对密度、硬度和导电性的影响,并对电镀制备机理进行研究。采用XRD、SEM、EDS、TEM、HRTEM等测试方法分析样品的显微结构。PEG与SDS的协同作用使WC-Cu复合材料在电镀过程中更加致密。WC-Cu复合材料的硬度随着WC含量的增加而增加,导电性随WC含量的增加而降低。随着添加剂含量的增加,样品的密度呈现先增大后减小的趋势。当电镀液中含有10 g/L WC纳米粉、0.2 g/L PEG和0.1 g/L SDS时,WC-Cu复合材料硬度为HV 221、电导率为53.7 MS/m。结果表明,通过优化添加剂和纳米WC颗粒的含量,可以得到性能优良的WC-Cu复合材料。

Study on Hydrogen Environment Fatigue Test System and Correlative Fatigue Test of Hydrogen Storage Vessel

A 70 MPa hydrogen environment fatigue test system has been designed and applied in the manufacture of a hydrogen storage vessel. The key equipment is a 80 MPa flat steel ribbon wound high pressure hydrogen storage vessel. A reasonable stress distribution has been realized, which is low stress on the liner of the pressure vessel and even stress on the flat ribbon layers. This optimal stress distribution is achieved through the adjustment of the prestress in flat steel ribbons. A control system for the fatigue test system has also been designed. It consists of a double control model, manual control and automatic control, to satisfy different experiment requirements. The system is the only one which can be used in the real hydrogen environmental fatigue test system in China. An experiment for a 70 MPa onboard composite material hydrogen vessel has been carried out on the system. The experimental results from this test are in close agreement with the practical operating conditions.

Fc effector of anti-Aβ antibody induces synapse loss and cognitive deficits in Alzheimer’s disease-like mouse model

Passive immunotherapy is one of the most promising interventions for Alzheimer’s disease(AD).However,almost all immune-modulating strategies fail in clinical trials with unclear causes although they attenuate neuropathology and cognitive deficits in AD animal models.Here,we showed that Aβ-targeting antibodies including their lgG1 and lgG4 subtypes induced microglial engulfment of neuronal synapses by activating CR3 or FcγRIIb via the complex of Aβ,antibody,and complement.Notably,anti-Aβantibodies without Fc fragment,or with blockage of CR3 or FcγRIIb,did not exert these adverse effects.Consistently,Aβ-targeting antibodies,but not their Fab fragments,significantly induced acute microglial synapse removal and rapidly exacerbated cognitive deficits and neuroinflammation in APP/PS1 mice post-treatment,whereas the memory impairments in mice were gradually rescued thereafter.Since the recovery rate of synapses in humans is much lower than that in mice,our findings may clarify the variances in the preclinical and clinical studies assessing AD immunotherapies.Therefore,Aβ-targeting antibodies lack of Fc fragment,or with reduced Fc effector function,may not induce microglial synaptic pruning,providing a safer and more efficient therapeutic alternative for passive immunotherapy for AD.

Fatigue test of carbon epoxy composite high pressure hydrogen storage vessel under hydrogen environment

A significant temperature raise within hydrogen vehicle cylinder during the fast filling process will be observed, while the strength and fatigue life of the cylinder will dramatically decrease at high temperature. In order to evaluate the strength and fatigue of composite hydrogen storage vessel, a 70-MPa fatigue test system using hydrogen medium was set up. Experimental study on the fatigue of composite hydrogen storage vessels under real hydrogen environment was performed. The experimental results show that the ultimate strength and fatigue life both decreased obviously compared with the values under hydraulic fatigue test. Furthermore, fatigue property, failure behavior, and safe hydrogen charging/discharging working mode of onboard hydrogen storage vessels were obtained through the fatigue tests.

Diagnosis of Malignancy of Adult Mediastinal Tumors by Conventional and Transesophageal Echocardiography

Background： Transesophageal echocardiography （TEE） is a well-established method for detecting and diagnosing heart tumors. In contrast, its role in assessing the presence, growth and evidence of malignant tumors originating from mediastinal sites remains unclear. The aim of this study was to compare the diagnostic impact of TEE and transthoracic echocardiography （TTE） for determining the localization, growth and malignancy of adult mediastinal tumors （MTs）. Methods： In a prospective and investigator-blinded study, we evaluated 144 consecutive patients with MT lesions to assess the diagnostic impact of TEE and TTE for detecting the presence of tumors spreading both inside and outside of the heart and for determining infiltration and invasion using pathological examination results as a reference. Results： All tumor lesions were diagnosed and carefully evaluated by biopsy. Biopsy revealed malignant tumors in 79 patients and benign tumors in 65 patients. When compared to histological findings, TEE predicted malignancy from the presence of tumors spreading both inside and outside of the heart and from infiltration and invasion in 49/79 patients （62.0%）. TTE predicted malignancy in only 8/79 patients （10.1%, P 〈 0.005）. TEE visualized tumor lesions in 130 patients （90.3%） while the TTE visualized tumor lesions in 110 patients （76.4%） and was less effective at detecting MT lesions （P 〈 0.001 ）. TTE and TEE could detect anterior MTs and adequately verified MTs （P 〉 0.05）： TEE detected medium MTs better than TTE （P 〈 0.001 ）. Conclusions： TEE is effective and superior to TTE for predicting the localization and growth of MTs as well as for accessing evidence of tumor malignancy. TTE and TEE were able to detect anterior MTs; TEE was able to detect medium MT better than TTE.

Genetic variation and cryptic lineage diversity of the Nigerian red-headed rock agama Agama agama associate with eco-geographic zones

Nigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism.Among its vertebrate fauna,reptiles have broad distributions,thus,they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification.The red-headed rock agama,Agama agama,lives in a wide range of habitats and,thus,it may show genetic structuring and diversification.Herein,we tested the hypothesis that ecology affects its genetic structure and population divergence.Bayesian inference phylogenetic analysis of a mitochondrial DNA(mtDNA)gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions.Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecologicalniche model for the matrilines had a good fit and robust performance. Population divergence alongthe environmental axes was associated with climatic conditions, and temperature ranked highestamong all environmental variables for forest specialists, while precipitation ranked highest for theforest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that nicheconservatism promotes geographic isolation of the western populations of Nigerian A. agama.Thus, ecological gradients and geographic isolation impact the genetic structure and population divergenceof the lizards. This species might be facing threats due to recent habitat fragmentation,especially in western Nigeria. Conservation actions appear necessary.

Paraneoplastic Eosinophilia in Clear Cell Renal Cell Carcinoma

To the Editor：Eosinophilia commonly occurs secondary to parasitic infections,allergy,collagen-vascular disease,hypersensitivity conditions,or underlying hematologic or solid malignancies.However,eosinophilia associated with clear cell renal cell carcinoma （CCRCC） is rare.Herein,we report a case of paraneoplastic eosinophilia associated with CCRCC.

An Increase of Heart Rate and Electrocardiographic Changes after Subcutaneous Liraglutide

To the Editor： Liraglutide Effect andAction in Diabetes： Evaluation of cardiovascular outcome results （LEADER） trial illustrated that among patients with type 2 diabetes mellitus, those in the liraglutide group had lower rates of cardiovascular events and death from any cause than did those in the placebo group.[1] Herein, we reported a case of an increase of heart rate （HR） and electrocardiographic changes after subcutaneous liraglutide.