Comparison of embolic agents for varices during transjugular intrahepatic portosystemic shunt for variceal bleeding: Tissue gel or coil?

Purpose:We aimed to compare treatment efficacy,safety and material cost between tissue gel and coil regarding variceal embolization during transjugular intrahepatic portosystemic shunt(TIPS).Materials&Methods:This retrospective study including cirrhotic patients with variceal bleeding treated with TIPS combined with variceal embolization between January 2016 and August 2017.Patients were divided into three groups according to embolic agents used in variceal embolization:tissue gel group(Group A),combination group(Group B),and coil group(Group C).The primary endpoint was 1-year rebleeding rate after TIPS creation.The secondary endpoints included shunt dysfunction,overt hepatic encephalopathy,liver function,and embolic agents-related expense.Results:A total of 60 patients(30,10,and 20 in Group A,B,and C)were included.Variceal rebleeding occurred in3(10%),0(0%),and 4(20%)patients within one year after TIPS creation in Group A,B,and C,respectively.Stent dysfunction occurred in 2(3.3%)patients and 9(15.0%)patients experienced overt hepatic encephalopathy.No significant differences were observed between three groups regarding primary and secondary endpoints except embolic agents-related expense,with a significantly lower cost in Group A when compared to the other two groups.Stent dysfunction occurred in two patients,with one patient in Group A developed acute occlusion caused by thrombus and another patient in Group C underwent stent stenosis during follow-up.Conclusions:Compares to coil alone or combines with coil,tissue gel has similar treatment efficacy and safety,but with significantly lower cost for variceal bleeding during TIPS.

Percutaneous transhepatic intrahepatic portosystemic shunt for variceal bleeding: A series of six cases and literature review

Objectives:To present a case series of modified transjugular intrahepatic portosystemic shunts(TIPS) and percutaneous transhepatic intrahepatic portosystemic shunts(PTIPS) in cirrhotic patients with variceal bleeding(VB).In addition,the scientific literature pertaining to PTIPS was reviewed.Methods:This retrospective clinical case series included six cirrhotic patients with VB who were treated with PTIPS after the failure of endoscopic band ligation or endoscopic injection sclerotherapy combined with vasoactive drugs.The treatment was conducted between January 2017 and June 2019 at a single institution.Three patients suffered from severe atrophy of the right or left lobar of the liver as well as the main right or left branch of the portal vein.The remaining three patients showed severe atrophy of the whole liver and portal vein,resulting in widening of the liver fissure.A paired t-test was used to compare the changes in portal pressure gradient between before and after the PTIPS operation.The rebleeding rate,treatment efficacy,complications,and technical success rate were all assessed during follow-up.Results:All six PTIPS procedures were performed successfully,with no severe procedural-related complications observed.None of the patients experienced VB during a mean follow-up of 22.8(range,18.0-28.0) months.The mean portosystemic pressure gradient decreased from 28.3 ± 4.3 mmHg pre-procedure to 12.3 ± 2.6 mmHg immediately post-procedure(P <0.001).At follow-up,one patient was found to have developed grade 2 hepatic encephalopathy thrice during the first year,according to the West Haven criteria.However,this was resolved following medical treatment.Conclusions:When the patient’s portal venous anatomy is unconducive to the performance of TIPS using the transjugular approach,PTIPS can be considered as a safe,effective complementary surgical approach for patients with VB.

Experimental investigation on hard rock fragmentation of inserted tooth cutter using a newly designed indentation testing apparatus

This investigation aims to explore the effects of stress conditions and rock cutting rates on hard rock fragmentation through indentation tests on a newly designed triaxial testing apparatus.This apparatus was designed to realize a triaxial loading and indentation test of cylindrical specimens using inserted tooth cutter.The boreability and crushing efficiency of granite rock was investigated by analyzing the change rules of the thrusting force,penetration depth,characteristics of chippings and failure patterns.Several quantitative indexes were used to evaluate rock boreability in this investigation.The granite rock samples all had a chiselled pit and a crushed rock core.Under initial stress conditions,only flat-shape chippings were stripped from the rock surface when the thrusting force reached 20 kN.The rock cutting special energy had a close correlation with the initial stress conditions and inserted tooth shape.Moreover,a thrusting force prediction model was proposed in this paper.The contribution of this study is that for the first time the influence mechanism of the initial triaxial stress conditions on rock fragmentation is investigated using an inserted tooth and the newly designed testing apparatus.This study has a crucial importance for practical underground hard rock crushing in geoengineering.

On the bramble way to Mg metal anodes in secondary Mg ion batteries

As a prospective alternative to lithium-ion batteries,rechargeable magnesium metal batteries(RMBs)have many unparalleled advantages,including direct use of Mg metal as the electrode;large nature abundance;intrinsically safe merits;high theoretical volumetric capacity.Nonetheless,there exist a large number of challenges on electrodes for their applications.Among them,surface passivation,uneven deposition/dissolution,and corrosion are critical issues that severely hinder the development of Mg anodes in RMBs.This review gives a specific comprehensive,and in-depth summary of mechanisms relative to these problems.Subsequently,it displays the protection progresses of the Mg metal anode via three-dimensional host nanostructure fabrication,Mg alloys anode design,current collector modification,artificial solid-electrolyte interphase construction,and electrolyte optimization.Finally,future perspectives and outlooks in developing the other blossom of these strategies for rechargeable Mg batteries are also discussed.This overview provides significant guidance for designing and fabricating high-performance Mg metal anodes in secondary Mg batteries and boosting their commercial applications.

多边共管的多模态网络标识域名生成管理解析原型系统

面对新形势下互联网蓬勃发展给现有网络体系带来的挑战,现有单边主义下的域名管理系统(DNS)在专业化服务质量和安全管控方面已力不从心.本文从分析现有网络体系问题出发,结合世界网络发展趋势,明确新型网络基本技术特征,以高安全、高鲁棒、高效能和高可用性为导向,提出新型多模态域名管理技术框架,实现融合多边共管的投票管理和多模态网络下标识域名互访和互隧道功能的原型系统.原型系统通过现网测试验证了理论的正确性和可行性.该系统可以方便地应用于自主多模态标识空间下的主权网及高安全专网,为全世界对网络共管共治的诉求提供了中国方案.

Mid-infrared active metasurface based on Si/VO_(2) hybrid meta-atoms

Active metasurfaces whose optical properties can be tuned by an external stimulus have attracted great research interest recently. Introduction of VO_(2)phase change material in all-dielectric metasurfaces has been demonstrated to modulate the resonance wavelength and amplitude in the visible to near-infrared wavelength range. In this study, we report a mid-infrared active metasurface based on Si∕VO_(2)hybrid meta-atoms. By incorporating VO_(2)thin films in different locations of Si∕VO_(2)all-dielectric nanodisks, we demonstrate different modulation amplitude of the electric or magnetic resonance scattering cross sections, leading to drastically different transmission spectrum upon VO_(2)insulator to metal phase transition. The physical mechanism is originated from the field profiles of the resonance modes, which interact with VO_(2)differently depending on its locations. Based on this mechanism, we experimentally demonstrated a large modulation of the transmittance from 82% to 28% at the 4.6 μm wavelength. Our work demonstrates a promising potential of VO_(2)-based active all-dielectric metasurface for mid-infrared photonic applications such as infrared camouflage, chemical/biomedical sensing, optical neuromorphic computing, and multispectral imaging.