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Improvement of impact properties of Al-Si-Mg alloy via solution treatment and joint modification with Sr and La

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Rare Metals 2024年第7期43卷 3301-3313页

作者： Xiong-Ling Zheng Shao-Xiang Li Jia-Le Ma Qing-yan Xu Hai-Dong Zhao zhi-Qiang Han Key Laboratory for Advanced Materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua University National Engineering Research Center of Near-Net Shape Forming for Metallic Materials South China University of Technology

An effort to obtain superior impact properties for Al-7Si-0.35 Mg alloy is presented,where modification with 0.02 wt% Sr and 0.1 wt% La as well as solution treatment was jointly *** samples were solution treated at 535℃ for 15 min to 12 *** microstructure,fracture mechanism,and their correlation with the impact properties of the alloy were studied in detail mainly through optical microscopy（OM）,scanning electron microscopy（SEM） and oscillography impact *** results show that the addition of Sr and La refined the eutectic Si particles significantly from～ 2.05 μm（modified with Sr alone） to～ 0.75 μm in as-cast microstructure,leading to a very homogeneous distribution of spheroidized Si particles in the alloy solution treated at 535℃ for 8 *** alloy exhibits excellent impact toughness up to 75 J·cm-2,which is much higher than the maximum impact toughness of the alloys modified by Sr alone(～ 46 J·cm-2).The major reason for this remarkable increase in the impact property is the dramatic increase in crack initiation *** dispersoid-free zones（DFZs）near the eutectic regions mainly consist of the ductile Al-matrix,which exhibits excellent *** ductile Al-matrix of the DFZs hinders the crack propagation,resulting in a significant increase in crack propagation energy.

关键词： Aluminum alloys Modification Solution treatment Microstructure Impact properties Fracture mechanism

Minimalistic approach to left atrial appendage occlusion guided by cardiac computed tomography angiography

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Journal of Geriatric Cardiology 2024年第4期21卷 431-442页

作者： Xian-Sai MENG Qing-Song WANG Xin-yan WANG Xu LU yang MU Jing WANG ting-ting SONG Yun-Dai CHEN Tao CHEN Jun GUO Graduate School of Chinese PLA Medical College BeijingChina Senior Department of Cardiology the Sixth Med-ical CenterChinese PLA General HospitalBeijingChina

OBJECTIVE To assess the feasibility and safety of the minimalistic approach to left atrial appendage occlusion(LAAO) guided by cardiac computed tomography angiography(CCTA).METHODS Ninety consecutive patients who underwent LAAO, with or without CCTA-guided, were matched(1:2). Each step of the LAAO procedure in the computed tomography(CT) guidance group(CT group) was directed by preprocedural CT planning. In the control group, LAAO was performed using the standard method. All patients were followed up for 12 months, and device surveillance was conducted using *** A total of 90 patients were included in the analysis, with 30 patients in the CT group and 60 matched patients in the control group. All patients were successfully implanted with Watchman devices. The mean ages for the CT group and the control group were 70.0 ± 9.4 years and 68.4 ± 11.9 years(P = 0.52), respectively. The procedure duration(45.6 ± 10.7 min vs. 58.8 ± 13.0 min,P < 0.001) and hospital stay(7.5 ± 2.4 day vs. 9.6 ± 2.8 day, P = 0.001) in the CT group was significantly shorter compared to the control group. However, the total radiation dose was higher in the CT group compared to the control group(904.9 ± 348.0 m Gy vs.711.9 ± 211.2 m Gy, P = 0.002). There were no significant differences in periprocedural pericardial effusion(3.3% vs. 6.3%, P = 0.8) between the two groups. The rate of postprocedural adverse events(13.3% vs. 18.3%, P = 0.55) were comparable between both groups at 12 months *** CCTA is capable of detailed LAAO procedure planning. Minimalistic LAAO with preprocedural CCTA planning was feasible and safe, with shortened procedure time and acceptable increased radiation and contras consumption. For patients with contraindications to general anesthesia and/or transesophageal echocardiography, this promising method may be an alternative to conventional LAAO.

关键词： anesthesia matched approach

Climate warming is likely to weaken the performance of two-phase closed thermosyphon on the Qinghai-Tibet Plateau

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Advances in Climate Change Research 2024年第1期15卷 90-100页

作者： Guan-Li JIANG Zi-Teng FU Xin-Yu MEN Hong-ting ZHAO Si-Ru GAO Yong-zhi LI Qing-Bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Beiluhe Observation and Research Station on Frozen Soil Engineering and Environment in the Qinghai-Tibet Plateau Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Muli Field Scientific Observation and Research Station for Gas Hydrate China Geological SurveyBeijing 100083China University of Chinese Academy of Sciences Beijing 100049China School of Civil Engineering and Architecture Jiaxing Nanhu UniversityJiaxing 314001China

Over the years,numerous geotechnical approaches have been implemented to mitigate the adverse effects of climate warming on various infrastructures in the permafrost region of the Qinghai-Tibet Plateau(QTP),such as the Qinghai-Tibet Highway and Railway,and achieved the expected engineering ***,little attention has been given to whether the performance of these geotechnical approaches has changed during the ongoing process of climate *** investigate the performance variation of one of these geotechnical approaches,which is two-phase closed thermosyphon(TPCT),during sustained climate warming,we conducted a statistical analysis of soil temperature monitoring data in 2003-2020 from eight regular embankments and six TPCT embankments in our permafrost monitoring *** results indicate that TPCT undeniably has a cooling effect on the permafrost beneath embankments,even rapidly eliminated previously formed taliks beneath ***,further analysis reveals that the performance of TPCT has been weakening during sustained climate warming,which has confirmed by the re-forming of the taliks beneath embankment where they had been previously *** on the current understanding,we attributed the weakening of thermosyphon performance to a significant reduction in the air temperature freezing index caused by ongoing climate *** this study,we aimed to draw attention to the evolving performance of geotechnical approaches in permafrost regions amid climate warming,prompting necessary engineering innovations to address this situation and ensure the sustainable development of the permafrost region on the QTP.

关键词： Two-phase closed thermosyphon Climate warming Supra-permafrost talik Permafrost degradation Qinghai-Tibet Highway

Quasi-in-situ Observation and SKPFM Studies on Phosphate Protective Film and Surface Micro-Galvanic Corrosion in Biological Mg-3Zn-xNd Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 648-664页

作者： Zhaochen Yu Kaixuan Feng Shuyun Deng yang Chen Hong yan Honggun Song Chao Luo zhi Hu School of Advanced Manufacturing Nanchang UniversityNanchang330031China Institute for Advanced Study Nanchang UniversityNanchang330031China

The phosphate protective film and micro-galvanic corrosion of biological Mg-3Zn-xNd (x = 0, 0.6, 1.2) alloys were investigated by scanning and transmission electron microscopy, quasi-in-situ observation, scanning Kelvin probe force microscopy (SKPFM) and electrochemical tests. The results revealed the Mg-Zn-Nd phases formed in Mg-3Zn alloy contained with Nd. Adding Nd resulted in a significant decline in the cracks of the phosphate protective film and micro-galvanic corrosion of alloys, which were recorded by quasi-in-situ observation. In addition, the Volta potential difference of Mg-Zn-Nd/α-Mg (~ 188 mV) was lower than MgZn/α-Mg (~ 419 mV) and Zn-rich/α-Mg (~ 260 mV), and the corrosion rates of alloys markedly decreased after the addition of 0.6 wt% Nd. The improvement in corrosion resistance of Nd-containing alloys was mainly attributed to the following: (i) the addition of Nd reduced the Volta potential difference (second phases/α-Mg);(ii) the phosphate protective film containing Nd_(2)O_(3) deposited on the surface of the alloys, effectively preventing the penetration of harmful anions.

关键词： Magnesium alloys Quasi-in-situ observation Phosphate protective film Scanning Kelvin probe force microscopy(SKPFM) Micro-galvanic corrosion

Computerized tomography-guided therapeutic percutaneous puncture catheter drainage-combined with somatostatin for severe acute pancreatitis: An analysis of efficacy and safety

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 59-66页

作者： Xue-Lan Zheng Wan-Ling Li yan-Ping Lin ting-Long Huang Department of Critical Care Medicine The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina CT Room The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina

BACKGROUND Severe acute pancreatitis(SAP),a condition with rapid onset,critical condition and unsatisfactory prognosis,poses a certain threat to human health,warranting optimization of relevant treatment plans to improve treatment *** To evaluate the efficacy and safety of computerized tomography-guided the-rapeutic percutaneous puncture catheter drainage(CT-TPPCD)combined with somatostatin(SS)in the treatment of *** Forty-two SAP patients admitted to The Second Affiliated Hospital of Fujian Medical University from June 2020 to June 2023 were *** the basis of routine treatment,20 patients received SS therapy(control group)and 22 patients were given CT-TPPCD plus SS intervention(research group).The efficacy,safety(pancreatic fistula,intra-abdominal hemorrhage,sepsis,and organ dysfunction syndrome),abdominal bloating and pain relief time,bowel recovery time,hospital stay,inflammatory indicators(C-reactive protein,interleukin-6,and pro-calcitonin),and Acute Physiology and Chronic Health Evaluation(APACHE)II score of both groups were evaluated for *** Compared with the control group,the research group had a markedly higher total effective rate,faster abdominal bloating and pain relief and bowel recovery,INTRODUCTION Pancreatitis,an inflammatory disease occurring in the pancreatic tissue,is classified as either acute or chronic and is associated with high morbidity and mortality,imposing a socioeconomic burden[1,2].The pathogenesis of this disease involves early protease activation,activation of nuclear factor kappa-B-related inflammatory reactions,and infiltration of immune cells[3].Severe acute pancreatitis(SAP)is a serious condition involving systemic injury and subsequent possible organ failure,accounting for 20%of all acute pancreatitis cases[4].SAP is also characterized by rapid onset,critical illness and unsatisfactory prognosis and is correlated with serious adverse events such as systemic inflammatory response syn-drome an

关键词： Computerized tomography guidance Therapeutic percutaneous puncture catheter drainage Somatostatin Severe acute pancreatitis Efficacy and safety

Loss of heterozygosity for chromosomes 16q in Wilms tumors predicts outcomes:A meta-analysis

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 2159-2167页

作者： Yuan-Hua Song Wen-Ling Li Zhen yang yan Gao zhi-Ping Feng Department of Oncology Kunming Children's HospitalKunming 650103Yunnan ProvinceChina Department of Nuclear Medicine The Third Affiliated Hospital of Kunming Medical University(Yunnan Cancer Hospital)Kunming 650118Yunnan ProvinceChina

BACKGROUND The research findings suggest that the prognosis of children with Wilms tumor(WT)is affected by various *** scholars have indicated that loss of heterozygosity(LOH)on chromosome 16q is associated with a poor prognosis in patients with *** To further elucidate this relationship,we conducted a *** This meta-analysis was registered in INPLASY(INPLASY2023100060).We systematically searched databases including Embase,PubMed,Web of Science,Cochrane,and Google Scholar up to May 31,2020,for randomized trials reporting any intrapartum fetal surveillance *** meta-analysis was performed within a frequentist framework,and the quality and network inconsistency of trials were *** ratios and 95%CIs were calculated to report the relationship between event-free survival and 16q LOH in patients with *** Eleven cohort studies were included in this meta-analysis to estimate the relationship between event-free survival and 16q LOH in patients with WT(I^(2)=25%,P<0.001).As expected,16q LOH can serve as an effective predictor of eventfree survival in patients with WT(risk ratio=1.95,95%CI:1.52–2.49,P<0.001).CONCLUSION In pediatric patients with WT,there exists a partial correlation between 16q LOH and an unfavorable treatment *** detection of 16q chromosome LOH warrants increased attention to the patient’s prognosis.

关键词： Loss of heterozygosity Wilms tumor Survival time Chromosomes 16q

The effects of deformation parameters and cooling rates on the aging behavior of AZ80+0.4%Ce

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Journal of Magnesium and Alloys 2024年第2期12卷 639-658页

作者： Yongbiao yang Jinxuan Guo Cuiying Wang ting yan Zhang Wenxuan Jiang zhimin Zhang Qiang Wang Guojun Li Jun Wang College of Materials Science and Engineering North University of ChinaLane 3Xueyuan RoadTaiyuanShanxiChina030051 State Key Laboratory of Advanced Stainless Steel Materials Taiyuan Iron Steel(Group)Co.Ltd.Taiyuan 030003China Technology Center Shanxi Taigang Stainless Steel Co.Ltd.Taiyuan 030003China

The extruded AZ80+0.4%Ce magnesium alloy was twisted in the temperature range of 300-380℃by using a Gleeble 3500 thermal simulation test machine with a torsion *** deformed cylindrical specimens were cooled at a cooling rate of 10℃/s or 0.1℃/s,respectively,and aged at 170℃.The microstructure analysis results showed that the grain size decreased with increasing specimen radial position from center(SRPC),and that the strong initial basal texture of the extruded magnesium alloy was *** continuous and discontinuous dynamic recrystallization mechanisms were involved in contributing to the grain refinement for all specimens *** a novel extension twinning induced dynamic recrystallization mechanism was proposed for specimen deformed at 300℃.For the specimens deformed at 300℃and 340℃followed by a slow cooling rate(0.1℃/s),precipitates of various shapes(β-Mg_(17)Al_(12)),with the dominant precipitates being on the grains boundaries,appeared on the surface *** specimen deformed at 380℃,lamellar precipitates(LPS)in the interiors of the grains were *** aging,the LPS still dominated for specimens twisted at 380℃;however,the LPS gradually decreased with decreasing deformation temperatures from 380℃to 300℃.Dynamically precipitatedβ,especially those decorating the grain boundaries,changed the competition pictures for the LPS and precipitates of other shapes after ***,LPS dominated the areas for the center section of the specimens after aging regardless of deformation *** temperature deformation with high SRPC followed by rapid cooling rate increased the micro hardness of the alloy after aging due to refined grain,reduced precipitates size,decreased lamellar spacing as well as strain hardening.

关键词： AZ80+0.4%Ce magnesium alloy Hot torsion Deformation parameters Cooling rate Aging Micro hardness

Removal of a guide-wire sliding into abdominal cavity via transgastric natural orifice transluminal endoscopic surgery: A case report

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World Journal of Clinical Cases 2024年第3期12卷 596-600页

作者： Shi-Ju Chen Da-Ya Zhang yan-ting Lv Fei-Hu Bai Graduate School Hainan Medical UniversityHaikou 571199Hainan ProvinceChina Department of Gastroenterology The Second Affiliated Hospital of Hainan Medical University570216 HaikouHainan ProvinceChina Department of Gastroenterology Clinical Medical Center of Hainan ProvinceHaikou 570216Hainan ProvinceChina

BACKGROUND Guidewire slippage into the peritoneal cavity during clinical operations is extremely ***,this paper aims to report a successful case of guidewire removal using transgastric natural orifice transluminal endoscopic surgery(NOTES).The goal is to enhance physicians'understanding of the management plan for this unique scenario and provide a valuable reference for clinical *** SUMMARY A 64-year-old man presented with abdominal distension and was diagnosed with cirrhosis combined with massive *** proceed with treatment,the patient underwent ultrasound-guided peritoneal puncture and underwent catheterization and ***,a 0.035-inch guidewire slipped into the abdominal cavity during the *** a comprehensive evaluation and consultation by a multidisciplinary team,the guidewire was successfully removed using *** This case highlights the potential consideration of transgastric NOTES removal when encountering a foreign body,such as a guidewire,within the abdominal cavity.

关键词： Guidewire Abdominal cavity Natural orifice transluminal endoscopic surgery Cirrhosis Massive ascites Case report

Gate-field control of valley polarization in valleytronics

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Chinese Physics B 2024年第6期33卷 2-12页

作者：张婷婷韩依琳张闰午余智明 Institute of Physics Chinese Academy of SciencesBeijing 100190China Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic Systemsand School of PhysicsBeijing Institute of TechnologyBeijing 100081China

Valleytronics materials are a kind of special semiconductors which can host multiple symmetry-connected and wellseparated electron or hole pockets in the Brillouin zone when the system is slightly n or p doped. Since the low-energy particles residing in these pockets generally are not easily scattered to each other by small perturbations, they are endowed with an additional valley degree of freedom. Analogous to spin, the valley freedom can be used to process information,leading to the concept of valleytronics. The prerequisite for valleytronics is the generation of valley polarization. Thus,a focus in this field is achieving the electric generation of valley polarization, especially the static generation by the gate electric field alone. In this work, we briefly review the latest progress in this research direction, focusing on the concepts of the couplings between valley and layer, i.e., the valley–layer coupling which permits the gate-field control of the valley polarization, the couplings between valley, layer, and spin in magnetic systems, the physical properties, the novel designing schemes for electronic devices, and the material realizations of the gate-controlled valleytronics materials.

关键词： band structure electronic transport optical properties spintronics