SpyGlass治疗难治性胆管结石有效性和安全性的Meta分析

目的评价SpyGlass治疗难治性胆管结石(DBDS)的有效性和安全性,并比较第一代与第二代SpyGlass、液电碎石与激光碎石治疗DBDS的疗效差异。方法检索多个中英文数据库建库至2021年2月的研究。通过纽卡斯尔-渥太华量表(NOS)和JADAD量表评估不同类型研究的方法学质量,并使用随机效应模型合并效应量。重要结局包括结石完全清除率、结石单次清除率、取石次数和不良事件发生率。结果最终37项研究符合纳入标准,包含3728例患者。结石完全清除率为0.947(95%CI:0.920~0.970),结石单次清除率为0.747(95%CI:0.682~0.807),取石次数为1.10次(95%CI:1.080~1.120),不良事件发生率为0.065(95%CI:0.046~0.087);二代SpyGlass在结石完全清除率、结石单次清除率、取石次数上优于一代SpyGlass(97.3%和92.2%、80.3%和67.8%、1.03和1.27次);激光碎石在结石完全清除率、结石单次清除率、取石次数、不良事件发生率上优于液电碎石(97.8%和91.0%、80.4%和70.1%、1.06和1.19次、6.5%和7.8%)。结论常规取石方法失败时,SpyGlass是治疗DBDS的一种安全有效的方法,二代SpyGlass结合激光碎石可能会得到更好的疗效。

血清抗凝血酶Ⅲ、纤维蛋白原对高危NSTE-ACS患者的评估价值

目的探讨非ST段抬高型急性冠状动脉综合征(NSTE-ACS)患者血清抗凝血酶Ⅲ(AT-Ⅲ)、纤维蛋白原(FIB)水平对高危患者的评估价值。方法选取2015年1月-2016年12月该院根据临床特征和冠状动脉造影(CAG)确诊为NSTE-ACS患者280例为实验组,依据全球急性冠状动脉事件注册(GRACE)评分将实验组分为低危组47例(≤108分)、中危组106例(109~140分)、高危组127例(>140分);根据临床特征和CAG排除NSTE-ACS患者40例作为对照组。分析AT-Ⅲ、FIB水平在不同组间的差异和与GRACE评分的相关性以及GRACE评分的独立影响因素;受试者工作曲线(ROC)分析AT-Ⅲ、FIB对高危NSTE-ACS的预测价值,Logistic多因素回归分析高危NSTE-ACS的预测指标。结果实验组AT-Ⅲ水平低于对照组,而FIB水平高于对照组(P<0.05);AT-Ⅲ水平与GRACE评分负相关(P<0.05),FIB水平与GRACE评分正相关(P<0.05);AT-Ⅲ、FIB是GRACE评分和高危风险的预测因素(P<0.05)。ROC分析显示:AT-Ⅲ、FIB ROC曲线面积为0.797、0.756(P<0.05);最佳界值分别为85.50和4.03;敏感性分别为69%和66%;特异性分别为91%和93%。结论 NSTE-ACS患者血清AT-Ⅲ、FIB水平与其危险分层密切相关,是评估危险分层和高危风险的预测因子。

Supercapacitor electrode based on few-layer h-BNNSs/rGO composite for wide-temperature-range operation with robust stable cycling performance

Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs)with a thickness of 2−4 atomic layers were fabricated via vacuum freeze-drying and nitridation.Then,the h-BNNSs/reduced graphene oxide(rGO)composite were further prepared using a hydrothermal method.Due to the combination of two two-dimensional(2D)van der Waals-bonded materials,the as-prepared h-BNNSs/rGO electrode exhibited robustness to wide-temperature-range operations from−10 to 50℃.When the electrodes worked in a neutral aqueous electrolyte(1 M Na2SO4),they showed a great stable cycling performance with almost 107%reservation of the initial capacitance at 0℃ and 111% at 50℃ for 5000 charge−discharge cycles.

Reaction mechanism for in-situ β-SiAlON formation in Fe3Si–Si3N4–Al2O3 composites

In this work,Fe_3Si–Si_3N_4–Al_2O_3 composites were prepared at 1300°C in an N_2 atmosphere using fused corundum and tabular alumina particles,Al_2O_3 fine powder,and ferrosilicon nitride(Fe_3Si–Si_3N_4) as raw materials and thermosetting phenolic resin as a binder.The effect of ferrosilicon nitride with different concentrations(0wt%,5wt%,10wt%,15wt%,20wt%,and 25wt%) on the properties of Fe_3Si–Si_3N_4–Al_2O_3 composites was investigated.The results show that the apparent porosity varies between 10.3% and 17.3%,the bulk density varies from 2.94 g/cm^3 and 3.30 g/cm^3,and the cold crushing strength ranges from 67 MPa to 93 MPa.Under the experimental conditions,ferrosilicon nitride,whose content decreases substantially,is unstable;part of the ferrosilicon nitride is converted into Fe_2C,whereas the remainder is retained,eventually forming the ferrosilicon alloy.Thermodynamic assessment of the Si_5AlON_7 indicated that the ferrosilicon alloy accelerated the reactions between Si_3N_4 and α-Al_2O_3 fine powder and that Si in the ferrosilicon alloy was nitrided directly,forming β-Si Al ON simultaneously.In addition,fused corundum did not react directly with Si_3N_4 because of its low reactivity.

Morphology characterization of periclase–hercynite refractories by reaction sintering

A periclase？hercynite brick was prepared via reaction sintering at 1600℃for 6 h in air using magnesia and reaction-sintered hercynite as raw materials. The microstructure development of the periclase-hercynite brick during sintering was investigated using X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy. The results show that during sintering, Fe^2＋, Fe^3＋ and Al^3＋ ions in hercynite crystals migrate and react with periclase to form（Mg1-xFex）（Fe2-yAly）O4 spinel with a high Fe/Al ratio. Meanwhile, Mg^2＋ in periclase crystals migrates into hercynite crystals and occupies the oxygen tetrahedron vacancies. This Mg^2＋ migration leads to the formation of（Mg1-uFeu）（Fe2-vAlv）O4 spinel with a lower Fe/Al ratio and results in Al3＋ remaining in hercynite crystals. Cation diffusion between periclase and hercynite crystals promotes the sintering process and results in the formation of a microporous structure.

Formation mechanism of calcium hexaluminate

To investigate the formation mechanism of calcium hexaluminate（CaAl_（12）O_（19）, CA_6）, the analytically pure alumina and calcia used as raw materials were mixed in CaO/Al_2O_3 ratio of 12.57：137.43 by mass. The raw materials were ball-milled and shaped into green specimens, and fired at 1300-1600°C. Then, the phase composition and microstructure evolution of the fired specimen were studied, and a first principle calculation was performed. The results show that in the reaction system of CaO and Al_2O_3, a small amount of CA_6 forms at 1300°C, and greater amounts are formed at 1400°C and higher temperatures. The reaction is as follows： CaO ·2Al_2O_3（CA_2） ＋ 4Al_2O_3 → CA_6. The diffusions of Ca^（2＋） in CA_2 towards Al_2O_3 and Al^（3＋） in Al_2O_3 towards CA_2 change the structures in different degrees of difficulty. Compared with the difficulty of structural change and the corresponding lattice energy change, it is deduced that the main formation mechanism is the diffusion of Ca^（2＋） in CA_2 towards Al_2O_3.

Microwave absorption properties of SiC@SiO2@Fe3O4 hybrids in the 2–18 GHz range

To enhance the microwave absorption performance of silicon carbide nanowires（SiCNWs）, SiO_2 nanoshells with a thickness of approximately 2 nm and Fe_3O_4 nanoparticles were grown on the surface of SiCNWs to form SiC@SiO_2@Fe_3O_4 hybrids. The microwave absorption performance of the SiC@SiO_2@Fe_3O_4 hybrids with different thicknesses was investigated in the frequency range from 2 to 18 GHz using a free-space antenna-based system. The results indicate that SiC@SiO_2@Fe_3O_4 hybrids exhibit improved microwave absorption. In particular, in the case of an SiC@SiO_2 to iron（III） acetylacetonate mass ratio of 1：3, the microwave absorption with an absorber of 2-mm thickness exhibited a minimum reflection loss of-39.58 d B at 12.24 GHz. With respect to the enhanced microwave absorption mechanism, the Fe_3O_4 nanoparticles coated on SiC@SiO_2 nanowires are proposed to balance the permeability and permittivity of the materials, contributing to the microwave attenuation.

Utility of multiple endoscopic techniques in differential diagnosis of gallbladder adenomyomatosis from gallbladder malignancy with bile duct invasion: A case report

BACKGROUND Gallbladder adenomyomatosis(GAM) is a benign lesion, characterized by thickening of the gallbladder wall and a focal mass, which overlap with the features of gallbladder malignancy. Consequently, differential diagnosis of GAM from gallbladder cancer is difficult and approximately 20% of suspected malignant biliary strictures are postoperatively confirmed as benign lesions.Herein, we report a case in which a preoperative diagnosis of GAM was made by a combination of endoscopic and imaging techniques.CASE SUMMARY A 40-year-old man was referred to our hospital chiefly for a fever and right upper abdominal pain with dark urine. Enhanced computed tomography showed thickening of the gallbladder wall and a mass in the gallbladder neck with involvement of the hepatic bile ducts, which was suspected to be malignant.Gallbladder malignancy with bile duct invasion was ruled out by subsequent endoscopic examinations, including endoscopic retrograde cholangiopancreatography, intraductal ultrasound, and Spy Glass. Endoscopic examinations showed a homogeneous hyperechoic lesion with smooth margins of benign bile duct stricture suggestive of inflammatory stenosis of the bile duct.The patient underwent laparoscopic cholecystectomy. GAM was postoperatively diagnosed and confirmed based on the histopathology results, which are consistent with the preoperative diagnosis. Notably, no malignant event occurred in the patient during a 12-mo follow-up period.CONCLUSION A combination of endoscopic techniques may help in the differential diagnosis of GAM from gallbladder cancer.

Reaction behavior of trace oxygen during combustion of falling FeSi75 powder in a nitrogen flow

To explore the reaction behavior of trace oxygen during the flash combustion process of falling FeSi75 powder in a nitrogen flow, a flash-combustion-synthesized Fe-Si;N;sample was heat-treated to remove SiO;. The samples before and after the treatment were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and the formation mechanism of SiO;was investigated. The results show that SiO;in the Fe-Si;N;is mainly located on the surface or around the Si;N;particles in dense areas, existing in both crystalline and amorphous states; when the FeSi75 particles, which are less than 0.074 mm in size, fell in up-flowing hot N;stream, trace oxygen in the N;stream did not significantly hinder the nitridation of FeSi75 particles as it was consumed by the surface oxidation of the generated Si;N;particles to form SiO;. At the reaction zone, the oxidation of Si;N;particles decreased the oxygen partial pressure in the N;stream and greatly reduced the opportunity for FeSi75 particles to be oxidized into SiO;; by virtue of the SiO;film developed on the surface, the Si;N;particles adhered to each other and formed dense areas in the material.

Morphology of α-Si_3N_4 in Fe–Si_3N_4 prepared via flash combustion

The state and formation mechanism of α-Si3N4 in Fe-Si3N4 prepared by flash combustion were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results indicate that α-SiaN4 crystals exist only in the Fe-Si3N4 dense areas. When FeSi75 particles react with N2, which generates substantial heat, a large number of Si solid particles evaporate. The product between Si gas and N2 is a mixture of α-Si3N4 and β-Si3N4. At the later stage of the flash combustion process, α-Si3N4 crystals dissolve and reprecipitate as α-Si3N4 and the β-Si3N4 crystals grow outward from the dense areas in the product pool. As the temperature decreases, the α-SiaN4 crystals cool before transforming into β-SiaN4 crystals in the dense areas of Fe-Si3N4. The phase composition of flash-combustion-synthesized Fe-SiaN4 is controllable through manipulation of the gas-phase reaction in the early stage and the α→β transformation in the later stage.

High-performance chromite by structure stabilization treatment

Chromite is an important raw material applied in refractories.Efforts have been made to obtain high-performance chromite by adding MgO and Al203 from the viewpoint of structure optimization.In order to explore the effect of Al203 and MgO on the structure,two formulas,i.e.,Mg-rich and Al-rich ones,were selected.The phase and microstructure development of samples heated in the temperature range of 1200-1600℃ were studied by X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry.MgO and Al203 added have diffused into chromite successfully by heat treatment.MgO diffuses into chromite,occupying the tetrahedral vacancies caused by the diffusion and oxidation of Fe2+ions to stabilize the structure.Al203 diffuses into the surface layer of chromite,forming spinel-sesquioxide structure.Al-rich sample which has spinel-sesquioxide structure shows better corrosion resistance toward fayalite slag than Mg-rich sample which has single spinel structure by blocking the interdiffusion between Fe^2+ions in fayalite slag and Mg^2+ions in chromite.