不同模具角度下反复弯曲-压平变形工艺对AZ31镁合金板材显微组织演变和变形行为的影响

采用不同角度模具的反复弯曲-压平变形工艺制备AZ31镁合金板材。通过FEM、OM、EBSD和硬度计研究AZ31镁合金在反复弯曲-压平变形过程中的显微组织演变和变形行为。结果表明,150°/150°模具在所有三组实验中都表现出最佳性能。随着道次的增加,合金的等效应变由于剪切和弯曲作用而显著提高。经过4道次后,合金的平均晶粒尺寸显著细化至1.7μm,基面织构被弱化,这是非基面滑移、动态再结晶和孪生引起的;尤其是锥面滑移有利于引发动态再结晶和孪生。合金的硬度值达到HV 77,这是滑移、孪生和动态再结晶竞争产生的显微组织和织构综合作用的结果。

Transjugular intrahepatic portosystemic shunt for esophagogastric variceal bleeding in patients with hepatocellular carcinoma and portal vein tumor thrombus

BACKGROUND Whether hepatocellular carcinoma(HCC)with portal vein tumor thrombus(PVTT)and acute esophagogastric variceal bleeding(EGVB)can improve the success rate of endoscopic hemostasis and overall survival(OS)from transjugular intrahepatic portosystemic shunt(TIPS)remains controversial.AIM To compare the clinical outcomes between TIPS and standard treatment for such HCC patients.METHODS This monocenter,retrospective cohort study included patients diagnosed as HCC with PVTT and upper gastrointestinal bleeding.Patients were grouped by the treatment(TIPS or standard conservative treatment).The success rate of en-doscopic hemostasis,OS,rebleeding rates,and main causes of death were ana-lyzed.RESULTS Between July 2015 and September 2021,a total of 77 patients(29 with TIPS and 48 with standard treatment)were included.The success rate of endoscopic hemostasis was 96.6%in the TIPS group and 95.8%in the standard treatment group.All the 29 patients in TIPS group successful underwent TIPS procedure and had a better OS compared with standard treatment within the first 160 days after treatment(68 days vs 43 days,P=0.022),but shorter OS after 160 days(298 days vs 472 days, P = 0.022). Cheng’s Classification of PVTT, total bilirubin and Child-Pugh class wereindependently negative associated with OS (all P < 0.05). The main causes of death were liver failure or hepaticencephalopathy (75.9%) in the TIPS group and rebleeding (68.8%) in the standard treatment.CONCLUSIONTIPS could reduce the risk of early death due to rebleeding and prolong short-term survival in HCC patients withPVTT and acute EGVB, which deserves further investigation.

Partial splenectomy using a laparoscopic bipolar radiofrequency device:A case report

We report a 51-year-old female patient with a solitary lymphangioma located in the upper splenic pole which was managed successfully with laparoscopic partial splenectomy.Surgery lasted 170 min and did not require blood transfusions.The patient recovered well post-operatively and was asymptomatic at the 3-mo follow-up.She had a normal platelet count and no recurrence on ultrasonography or computed tomography.Laparoscopic partial splenectomy is a safe,minimally invasive technique for the treatment of solitary splenic lymphangiomas in the splenic pole.We performed the procedure using the HabibTM 4X device.This laparoscopic bipolar radiofrequency device ensured a "bloodless" splenic parenchymal resection.

Force-displacement characteristics of simply supported beam laminated with shape memory alloys

As a preliminary step in the nonlinear design of shape memory alloy（SMA） composite structures,the force-displacement characteristics of the SMA layer are studied.The bilinear hysteretic model is adopted to describe the constitutive relationship of SMA material.Under the assumption that there is no point of SMA layer finishing martensitic phase transformation during the loading and unloading process,the generalized restoring force generated by SMA layer is deduced for the case that the simply supported beam vibrates in its first mode.The generalized force is expressed as piecewise-nonlinear hysteretic function of the beam transverse displacement.Furthermore the energy dissipated by SMA layer during one period is obtained by integration,then its dependencies are discussed on the vibration amplitude and the SMA＇s strain（Ms-Strain） value at the beginning of martensitic phase transformation.It is shown that SMA＇s energy dissipating capacity is proportional to the stiffness difference of bilinear model and nonlinearly dependent on Ms-Strain.The increasing rate of the dissipating capacity gradually reduces with the amplitude increasing.The condition corresponding to the maximum dissipating capacity is deduced for given value of the vibration amplitude.The obtained results are helpful for designing beams laminated with shape memory alloys.

Preoperative MRI Classification May Not Predict Symptom Relief after Uterine Artery Embolization in Patients with Adenomyosis

Objective:To investigate the association between magnetic resonance imaging(MRI)classification and symptom relief after uterine artery embolization(UAE)in patients with adenomyosis.Methods:Totally,73 patients with symptomatic adenomyosis who underwent UAE were retrospectively analyzed.Preoperative MRI classification was defined as:type Ⅰ,high signal on both T2-weighted images(T2WI)and T1-weighted images(T1WI);type Ⅱ,high signal only on T2WI,and type Ⅲ,high signal on neither T1WI nor T2WI.Dysmenorrhea was measured with the visual-analog scales and the degree of menorrhagia was measured according to the number of sanitary pads used in one menstrual cycle.Dysmenorrhea and menorrhagia were measured before UAE and 12 months after UAE.Results:The number of the type Ⅰ,Ⅱ,Ⅲ cases was 23,37,and 13,respectively.The baseline characteristics of the three groups exhibited no significant difference.The alleviation rates of dysmenorrhea among type Ⅰ,Ⅱ,Ⅲ cases were 73.9%,89.2%,and 84.6%,respectively(P=0.455).The alleviation rates of menorrhagia for type Ⅰ,Ⅱ,Ⅲ were 69.6%,78.4%,and 92.3%,respectively(P=0.714).Conclusion:Pre-procedure MRI classification and symptom relief after UAE exhibited no significant association.UAE has a favorable mid-term control on dysmenorrhea and menorrhagia among patients with adenomyosis.Preoperative MRI classification might not indicate symptom relief.More research is needed before changing clinical practice.

“An integrated system,three separated responsibilities”,a new fever clinic management model,in prevention and control of novel coronavirus pneumonia

BACKGROUND Since December 2019,there have been many new cases of coronavirus pneumonia in Wuhan,Hubei Province,which has gradually spread throughout the country.AIM To explore our hospital’s innovative management system to ensure the efficient operation of fever clinics during the epidemic,since controlling the spread of disease is an important way to prevent and control the epidemic.METHODS In total,200 outpatients with fever at our hospital between November 2019 and July 2020 were selected and allocated into two groups.RESULTS The fever clinic in our hospital operated smoothly,and infection with the novel coronavirus disease(COVID-19)has not been reported in our hospital.Additionally,we did not have any cases of missed diagnosis.The awareness regarding COVID-19 infection sources,transmission routes,early symptoms,and preventive measures was significantly higher in our fever clinic than in those of the pre-management group.CONCLUSION"An integrated system,three separate responsibilities"ensured the efficient functioning of our fever outpatient clinic and early screening of COVID-19 cases,which effectively curbed the transmission of COVID-19 and hence prevented COVID-19 pneumonia epidemic in our hospital,ultimately achieving the maximum effect of epidemic prevention and control.

FHL2 Antagonizes Id1-Promoted Proliferation and Invasive Capacity of Human MCF-7 Breast Cancer Cells

Objective：FHL2 was previously identified to be a novel interacting factor of Id family proteins.The aim of this study was to investigate,the effects of FHL2 on Id1-mediated transcriptional regulation activity and its oncogenic activity in human breast cancer cells.Methods：Cell transfection was performed by Superfect reagent.Id1 stably overexpressed MCF-7 cells was cloned by G418 screening.The protein level of Id1 was detected by western blot analysis.Dual relative luciferase assays were used to measure the effect of E47-mediated transcriptional activity in MCF-7 human breast cancer cells.MTT assay was used to measure cell proliferation.Transwell assay was used to measure the invasive capacity of MCF-7 cancer cells.Results：The basic helix-loop-helix（bHLH） factor E47-mediated transcription activity was markedly repressed by Id1 in MCF-7 cells.This Id1-mediated repression was effectively antagonized by FHL2 transduction.Overexpression of Id1 markedly promoted the proliferation rate and invasive capacity of MCF-7 cells;however,these effects induced by Id1 were significantly suppressed by overexpression of FHL2 in cells.Conclusion：FHL2 can inhibit the proliferation and invasiveness of human breast cancer cells by repressing the functional activity of Id1.These findings provide the basis for further investigating the functional roles of FHL2-Id1 signaling in the carcinogenesis and development of human breast cancer.

Exosomal miRNA in early-stage hepatocellular carcinoma

The incidence and mortality of hepatic carcinoma(HCC)remain high,and early diagnosis of HCC is seen as a key approach in improving clinical outcomes.However,the sensitivity and specificity of current early screening methods for HCC are not satisfactory.In recent years,research around exosomal miRNA has gradually increased,and these molecules have emerged as attractive candidates for early diagnosis and treatment of HCC.This review summarizes the feasibility of using miRNAs in peripheral blood exosomes as early diagnostic tools for HCC.

Genomic data and ecological niche modeling reveal an unusually slow rate of molecular evolution in the Cretaceous Eupteleaceae

Living fossils are evidence of long-term sustained ecological success.However,whether living fossils have little molecular changes remains poorly known,particularly in plants.Here,we have introduced a novel method that integrates phylogenomic,comparative genomic,and ecological niche modeling analyses to investigate the rate of molecular evolution of Eupteleaceae,a Cretaceous relict angiosperm family endemic to East Asia.We assembled a high-quality chromosome-level nuclear genome,and the chloroplast and mitochondrial genomes of a member of Eupteleaceae(Euptelea pleiosperma).Our results show that Eupteleaceae is most basal in Ranunculales,the earliest-diverging order in eudicots,and shares an ancient whole-genome duplication event with the other Ranunculales.We document that Eupteleaceae has the slowest rate of molecular changes in the observed angiosperms.The unusually low rate of molecular evolution of Eupteleaceae across all three independent inherited genomes and genes within each of the three genomes is in association with its conserved genome architecture,ancestral woody habit,and conserved niche requirements.Our findings reveal the evolution and adaptation of living fossil plants through large-scale environmental change and also provide new insights into early eudicot diversification.

Identification of a novel coronavirus causing severe pneumonia in human:a descriptive study

Background:Human infections with zoonotic coronaviruses(CoVs),including severe acute respiratory syndrome(SARS)-CoV and Middle East respiratory syndrome(MERS)-CoV,have raised great public health concern globally.Here,we report a novel batorigin CoV causing severe and fatal pneumonia in humans.Methods:We collected clinical data and bronchoalveolar lavage(BAL)specimens from five patients with severe pneumonia from Wuhan Jinyintan Hospital,Hubei province,China.Nucleic acids of the BAL were extracted and subjected to next-generation sequencing.Virus isolation was carried out,and maximum-likelihood phylogenetic trees were constructed.Results:Five patients hospitalized from December 18 to December 29,2019 presented with fever,cough,and dyspnea accompanied by complications of acute respiratory distress syndrome.Chest radiography revealed diffuse opacities and consolidation.One of these patients died.Sequence results revealed the presence of a previously unknownβ-CoV strain in all five patients,with 99.8%to 99.9%nucleotide identities among the isolates.These isolates showed 79.0%nucleotide identity with the sequence of SARS-CoV(GenBank NC_004718)and 51.8%identity with the sequence of MERS-CoV(GenBank NC_019843).The virus is phylogenetically closest to a bat SARS-like CoV(SL-ZC45,GenBank MG772933)with 87.6%to 87.7%nucleotide identity,but is in a separate clade.Moreover,these viruses have a single intact open reading frame gene 8,as a further indicator of bat-origin CoVs.However,the amino acid sequence of the tentative receptor-binding domain resembles that of SARS-CoV,indicating that these viruses might use the same receptor.Conclusion:A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.

Toughening of Polycarbonate through Reactive Melt Blending: Effect of Hydroxyl Content and Viscosity of Hydroxyl-terminated Polydimethysiloxane

In this study, four hydroxyl-terminated polydimethylsiloxanes （PDMSOH） with different viscosities and hydroxyl contents were used to improve the toughness of polycarbonate （PC） through reactive melt blending. A largely improved toughness of PC has been achieved, and the low temperature toughness of PC/PDMSOH blends could overtake that of PC homopolymer in much higher temperatures （e.g. -10 ~C versus 23 ~C）. Moreover, it was found that the more the hydroxyl content, the less the PDMSOH was needed to reach the highest toughness, suggesting that equivalent molar ratio between the carbonyl group content of PC and the hydroxyl group content of PDMSOH was required for the toughening of PC. Ultraviolet spectrophotometry was used to analyze the possible reaction between PC and PDMSOH. Contact angle was measured to assess the change of interfacial interaction between PC and PDMSOH as change of viscosity and hydroxyl content. The formation of PC-co-PDMSOH copolymer was believed to be the key for the toughening effect. This work gives a profound recommendation of the optimum kind and dosage of PDMSOH which should be used to improve the toughness of PC and will find immediate industrial applications.