Sepsis-associated liver injury:Mechanisms and potential therapeutic targets

In this editorial,we examined a recent article in the World Journal of Gastroenterology that focused on sepsis-associated liver injury(SLI)and its treatment.SLI is a serious complication of sepsis,primarily caused by microcirculatory disturbances,the gut-liver axis,and inflammatory responses.Specific treatment recommendations for SLI are lacking.The gut-liver axis represents a potential therapeutic target,with metformin showing promise in modulating the gut microbiome and enhancing intestinal barrier function.Although immunomodulatory therapies are being explored,anti-tumor necrosis factor agents and interleukin-1 receptor antagonists have not demonstrated significant clinical benefits.Statins may reduce liver inflammation and prevent injury in sepsis,but their clinical application is limited.Reduced D-related human leucocyte antigen expression on monocytes and lymphocytes suggests immune suppression in patients,indicating that corticosteroids could reverse clinical deterioration in severe infections and address adrenal cortical insufficiency.Current large-scale studies on glucocorticoid therapy for sepsis have yielded mixed results,likely due to inadequate assessment of the immune status of the host.Future research should prioritize the development of personalized immunotherapy tailored to patients’immune profiles,focusing on identifying novel indicators of immune status and advancing immunomodulatory targets and therapeutics for septic patients.

Integrated causal inference modeling uncovers novel causal factors and potential therapeutic targets of Qingjin Yiqi granules for chronic fatigue syndrome

Objective:Chronic fatigue syndrome(CFS)is a prevalent symptom of post-coronavirus disease 2019(COVID-19)and is associated with unclear disease mechanisms.The herbal medicine Qingjin Yiqi granules(QJYQ)constitute a clinically approved formula for treating post-COVID-19;however,its potential as a drug target for treating CFS remains largely unknown.This study aimed to identify novel causal factors for CFS and elucidate the potential targets and pharmacological mechanisms of action of QJYQ in treating CFS.Methods:This prospective cohort analysis included 4,212 adults aged≥65 years who were followed up for 7 years with 435 incident CFS cases.Causal modeling and multivariate logistic regression analysis were performed to identify the potential causal determinants of CFS.A proteome-wide,two-sample Mendelian randomization(MR)analysis was employed to explore the proteins associated with the identified causal factors of CFS,which may serve as potential drug targets.Furthermore,we performed a virtual screening analysis to assess the binding affinity between the bioactive compounds in QJYQ and CFS-associated proteins.Results:Among 4,212 participants(47.5%men)with a median age of 69 years(interquartile range:69–70 years)enrolled in 2004,435 developed CFS by 2011.Causal graph analysis with multivariate logistic regression identified frequent cough(odds ratio:1.74,95%confidence interval[CI]:1.15–2.63)and insomnia(odds ratio:2.59,95%CI:1.77–3.79)as novel causal factors of CFS.Proteome-wide MR analysis revealed that the upregulation of endothelial cell-selective adhesion molecule(ESAM)was causally linked to both chronic cough(odds ratio:1.019,95%CI:1.012–1.026,P=2.75 e^(−05))and insomnia(odds ratio:1.015,95%CI:1.008–1.022,P=4.40 e^(−08))in CFS.The major bioactive compounds of QJYQ,ginsenoside Rb2(docking score:−6.03)and RG4(docking score:−6.15),bound to ESAM with high affinity based on virtual screening.Conclusions:Our integrated analytical framework combining epidemiological,genetic,and in silico data provides a novel strategy for elucidating complex disease mechanisms,such as CFS,and informing models of action of traditional Chinese medicines,such as QJYQ.Further validation in animal models is warranted to confirm the potential pharmacological effects of QJYQ on ESAM and as a treatment for CFS.

Key elements and checklist of shared decisionmaking conversation on life-sustaining treatment in emergency:a multispecialty study from China

BACKGROUND:Shared decision-making(SDM)has broad application in emergencies.Most published studies have focused on SDM for a certain disease or expert opinions on future research gaps without revealing the full picture or detailed guidance for clinical practice.This study is to investigate the optimal application of SDM to guide life-sustaining treatment(LST)in emergencies.METHODS:This study was a prospective two-round Delphi consensus-seeking survey among multiple stakeholders at the China Consortium of Elite Teaching Hospitals for Residency Education.Participants were identified based on their expertise in medicine,law,administration,medical education,or patient advocacy.All individual items and questions in the questionnaire were scored using a 5-point Likert scale,with responses ranging from"very unimportant"(a score of 1)to"extremely important"(a score of 5).The percentages of the responses that had scores of 4-5on the 5-point Likert scale were calculated.A Kendall’s W coefficient was calculated to evaluate the consensus of experts.RESULTS:A two-level framework consisting of 4 domains and 22 items as well as a ready-touse checklist for the informed consent process for LST was established.An acceptable Kendall’s W coefficient was achieved.CONCLUSION:A consensus-based framework supporting SDM during LST in an emergency department can inform the implementation of guidelines for clinical interventions,research studies,medical education,and policy initiatives.

Magneto-hydrodynamic simulation study of direct current multi-contact circuit breaker for equalizing breaking arc

This work is based on a direct current(DC)natural current commutation topology,which uses load-carrying branch contacts carrying rated current and multiple sets of series arcing branch contacts in parallel to achieve circuit breaking.The proposed topology can meet the new requirements of higher voltage DC switches in aviation,aerospace,energy and other fields.First,a magneto-hydrodynamic arc model is built using COMSOL Multiphysics,and the different arc breaking characteristics of the arcing branch contacts in different gas environments are simulated.Then,a voltage uniformity coefficient is used to measure the voltage sharing effect in the process of dynamic interruption.In order to solve the dispersion of arcing contact action,a structural control method is adopted to improve the voltage uniformity coefficient.The uniform voltage distribution can improve the breaking capacity and electrical life of the series connection structure.

以学生为中心、成果为目标导向对化学工程与工艺生产实习进行教学改革

生产实习是化学工程与工艺专业最重要的生产实践课程,其目的是将所学的理论知识与生产实践相结合,使学生对工厂企业的环境现状有一个感性认识,并且对化学工程现状有进一步了解,对未来的就业有个初步认识。结合江苏理工学院化学工程与工艺专业的定位和人才培养目标,以学生为中心,以成果为目标导向对化学工程与工艺生产实习进行教学改革,达到提高学生解决复杂工程问题的能力,能够承担社会责任,具有环境保护和可持续发展的意识,遵守工程职业道德和规范,具有团队精神等。

肩关节镜下喙突单隧道固定与无隧道悬吊固定治疗急性Ⅲ-Ⅴ型肩锁关节脱位

背景:目前国内外对关节镜下喙突无隧道悬吊固定与喙突单隧道固定治疗肩锁关节脱位的术后疗效研究报道较少,两种术式的具体临床疗效及是否存在其他风险有待探索。目的:比较关节镜下使用TightRope带袢带钢板喙突单隧道固定与喙突无隧道悬吊固定治疗急性Ⅲ-Ⅴ型肩锁关节脱位的短期临床疗效。方法:回顾性分析2019年6月至2022年9月新疆医科大学第六附属医院收治符合纳入标准的45例肩锁关节脱位患者,根据手术治疗方案分为2组,喙突单隧道组20例行肩关节镜下喙突单隧道固定,喙突无隧道组25例行肩关节镜下喙突无隧道悬吊固定。比较两组手术时间、切口长度及围术期失血量;对比两组术前、术后3个月及末次随访时肩关节Constant-Murley评分、目测类比评分、美国肘肩关节外科医师协会评分及术中、术后并发症等评价指标。结果与结论:①所有患者均顺利完成手术,术中无重要神经、血管损伤,喙突无隧道组手术时间较喙突单隧道组更短,差异有显著性意义(P<0.05),两组术中出血量、切口长度无显著差异(P>0.05);②所有患者随访12-24个月,平均随访(15.29±2.73)个月;③喙突单隧道组内比较:在术后3个月及末次随访时,目测类比评分较术前显著降低(P<0.05);Constant-Murley评分、美国肘肩关节外科医师协会评分较术前显著增加(P<0.05);喙突无隧道组内比较:在术后3个月及末次随访时,目测类比评分较术前显著降低(P<0.05);Constant-Murley评分、美国肘肩关节外科医师协会评分较术前显著增加(P<0.05);两组比较:在术后3个月随访时,喙突无隧道组Constant-Murley评分高于喙突单隧道组(P<0.05);两组间目测类比评分、美国肘肩关节外科医师协会评分相比差异无显著性意义(P>0.05);在术前及末次随访时,两组各评分在对应时间点之间比较差异均无显著性意义(P>0.05);④术中、术后并发症:喙突单隧道组在术中钻取隧道时发生1例喙突皮质破裂骨折,1例在术后3个月出现复位丢失,予以钩钢板+喙肩韧带转位重新复位固定;所有患者在末次随访中肩锁关节功能恢复良好且未发生再脱位;⑤提示关节镜下两种手术方法治疗急性Ⅲ-Ⅴ型肩锁关节脱位均具有创伤小、复位和固定可靠及术后肩关节功能恢复良好等优点,但是与喙突单隧道技术相比,喙突无隧道悬吊固定需要的手术时间更短、短期肩关节功能恢复快且避免了在喙突上建立骨隧道,减少了术中喙突发生医源性骨折的概率,安全性更高。

OSMR is a potential driver of inflammation in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a neurodegenerative disease,and the molecular mechanism underlying its pathology remains poorly understood.However,inflammation is known to play an important role in the development of this condition.To identify driver genes that affect the inflammatory response in amyotrophic lateral sclerosis,as well as potential treatment targets,it is crucial to analyze brain tissue samples from patients with both sporadic amyotrophic lateral sclerosis and C9orf72-related amyotrophic lateral sclerosis.Therefore,in this study we used a network-driven gene analysis tool,NetBID2.0,which is based on SJARACNe,a scalable algorithm for the reconstruction of accurate cellular networks,to experimentally analyze sequencing data from patients with sporadic amyotrophic lateral sclerosis.The results showed that the OSMR gene is pathogenic in amyotrophic lateral sclerosis and participates in the progression of amyotrophic lateral sclerosis by mediating the neuroinflammatory response.Furthermore,there were differences in OSMR activity and expression between patients with sporadic amyotrophic lateral sclerosis and those with C9orf72-related amyotrophic lateral sclerosis.These findings suggest that OSMR may be a diagnostic and prognostic marker for amyotrophic lateral sclerosis.

Pathological mechanisms of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis refers to a neurodegenerative disease involving the motor system,the cause of which remains unexplained despite several years of research.Thus,the journey to understanding or treating amyotrophic lateral sclerosis is still a long one.According to current research,amyotrophic lateral sclerosis is likely not due to a single factor but rather to a combination of mechanisms mediated by complex interactions between molecular and genetic pathways.The progression of the disease involves multiple cellular processes and the interaction between different complex mechanisms makes it difficult to identify the causative factors of amyotrophic lateral sclerosis.Here,we review the most common amyotrophic lateral sclerosis-associated pathogenic genes and the pathways involved in amyotrophic lateral sclerosis,as well as summarize currently proposed potential mechanisms responsible for amyotrophic lateral sclerosis disease and their evidence for involvement in amyotrophic lateral sclerosis.In addition,we discuss current emerging strategies for the treatment of amyotrophic lateral sclerosis.Studying the emergence of these new therapies may help to further our understanding of the pathogenic mechanisms of the disease.

Design of hadronic calorimeter for DarkSHINE experiment

The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used and the design of the detector geometry.This paper presents the optimized design of the hadronic calorimeter(HCAL)used in the DarkSHINE experiment,which is studied using a GEANT4-based simulation framework.The geometry is optimized by comparing a traditional design with uniform absorbers to one that uses different thicknesses at different locations on the detector,which enhances the efficiency of vetoing low-energy neutrons at the sub-GeV level.The overall size and total amount of material used in the HCAL are optimized to be lower,owing to the load and budget requirements,whereas the overall performance is studied to satisfy the physical objectives.

The potential mechanism of Isodon suzhouensis against COVID-19 via EGFR/TLR4 pathways

Corona Virus Disease 2019(COVID-19)has brought the new challenges to scientific research.Isodon suzhouensis has good anti-inflammatory and antioxidant stress effects,which is considered as a potential treatment for COVID-19.The possibility for the treatment of COVID-19 with I.suzhouensis and its potential mechanism of action were explored by employing molecular docking and network pharmacology.Network pharmacology and molecular docking were used to screen drug targets,and lipopolysaccharide(LPS)induced RAW264.7 and NR8383 cells inflammation model was used for experimental verification.Collectively a total of 209 possible linkages against 18 chemical components from I.suzhouensis and 1194 COVID-19 related targets were selected.Among these,164 common targets were obtained from the intersection of I.suzhouensis and COVID-19.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enriched 582 function targets and 87 target proteins pathways,respectively.The results from molecular docking studies revealed that rutin,vitexin,isoquercitrin and quercetin had significant binding ability with 3 chymotrypsin like protease(3CLpro)and angiotensin converting enzyme 2(ACE2).In vitro studies showed that I.suzhouensis extract(ISE)may inhibit the activation of PI3K/Akt pathway and the expression level of downstream proinflammatory factors by inhibiting the activation of epidermal growth factor receptor(EGFR)in RAW264.7 cells induced by LPS.In addition,ISE was able to inhibit the activation of TLR4/NF-κB signaling pathway in NR8383 cells exposed to LPS.Overall,the network pharmacology and in vitro studies conclude that active components from I.suzhouensis have strong therapeutic potential against COVID-19 through multi-target,multi-pathway dimensions and can be a promising candidate against COVID-19.

健康中国2030战略背景下食品卫生与营养学专业培养方案之营养课程体系现况调查

目的:了解健康中国2030战略背景下各医学高校食品卫生与营养学专业培养方案中营养课程设置现状。方法:查找全国不同区域共32份营养专业培养方案进行整理分析,内容包括培养目标、课程设置、营养相关课程开设情况等。结果:全国开设食品卫生与营养学专业的本科高校共计32所,其中985高校2所(上海交通大学、四川大学),普通本科高校30所。毕业学分要求从152~280(193.4±34.6)学分不等,985高校和普通高校的理论课时总数和实验课时总数之比分别为(1.6±0.6)与(1.7±0.4),差异无统计学意义(P>0.05)。营养专业核心课程(营养与食品卫生学、临床营养学、人群营养学、公共营养学等)的总学时数254~716(456.3±52.7)不等。各高校间食品卫生与营养学专业的课程设置差异较大。选取的3所高校专业课程能涵盖注册营养师课程设置要求,但部分模块学时数较低,未达到注册营养师要求的最低标准。结论:高校设置食品卫生与营养学专业课程时应结合《健康中国行动(2019-2030年)》和《国民营养计划(2017-2030年)》,明确人才培养目标,加强新时代本科生营养理念的培养,建议从强化营养为先的观念、完善注册营养师课程体系、注重营养与临床融合发展和提升营养实践技能4个方面不断完善食品卫生与营养学专业人才培养方案。

丹桂止氛汤加味治疗妊娠期糖尿病临床疗效及对妊娠结局的影响

目的:观察丹桂止氛汤加味治疗妊娠期糖尿病(GDM)的临床疗效及对妊娠结局的影响。方法:选取GDM患者62例,按随机数字表法分为对照组和联合组各31例。对照组参考GDM指南行常规治疗方案,联合组在对照组基础上予丹桂止氛汤加味治疗。2组均治疗8周。评价2组临床疗效,比较2组血糖指标、胰岛素抵抗指标及妊娠结局。结果:治疗后,联合组总有效率为96.77%,高于对照组74.19%(P<0.05)。治疗后,2组空腹血糖(FBG)、餐后2h血糖(P2hBG)、糖化血红蛋白(HbA1c)较治疗前降低(P<0.05),且联合组FBG、P2hBG、HbA1c低于对照组(P<0.05)。治疗后,2组空腹胰岛素(FINS)、胰岛素抵抗指数(HOMA-IR)较治疗前降低(P<0.05),且联合组FINS、HOMA-IR低于对照组(P<0.05)。联合组剖宫产率、胎儿呼吸窘迫综合征发生率低于对照组(P<0.05)。结论:丹桂止氛汤加味治疗GDM疗效明显,可改善患者的血糖水平与胰岛素抵抗,减少不良妊娠结局。

四川涉藏州县农业生态环境保护与农业协调发展研究

四川涉藏州县农业生态环境保护与农业协调发展对促进区域生态环境保护、产业发展具有重要现实意义,二者在价值取向、实现路径、目标导向方面具有一致性。文章运用综合评价模型、耦合度模型、耦合协调度模型及相对发展模型,计算2010—2019年四川涉藏州县农业生态环境保护与农业发展水平以及耦合协调状况。结果显示,2010—2019年四川涉藏州县农业生态环境保护水平、农业发展水平总体呈波动增长趋势,2015年后开始呈现稳定增长趋势。耦合协调度经历了中度失调、勉强协调、初级协调和中级协调四个阶段,总体呈快速增长趋势。文章提出贯彻落实新发展理念,优化产业结构,走绿色农业发展之路,建立健全绿色生态的农业政策支持体系,促进四川涉藏州县农业生态环境与农业的协调发展等建议。

食品卫生与营养学专业课程线上线下混合式教学的探索——以《营养学基础》为例

为实现食品卫生与营养学专业课堂教学中线上线下混合模式的改革,本文在做好学情分析、夯实课程内容的基础上,利用超星学习通线上教学平台建立SPOC课程,实施线上线下混合式教学。结合线上线下混合式教学做好课程设计,从内容切换、施教环节的设置上保障线上教学质量,及时进行知识归纳和学情反馈。通过教学实践,期末考试测验优良率为92%,学生对课程的满意度达到95%,完成了既定教学任务,达到了应有的教学效果。

阿托西班对反复种植失败患者冻融胚胎移植临床结局的影响

目的:探讨不同病因反复种植失败患者冻融胚胎移植术前使用阿托西班对临床结局的影响。方法:选取2019年1月—2021年1月在南京医科大学第一附属医院生殖医学科冻融胚胎移植周期中诊断为反复种植失败的患者,利用倾向性评分匹配法共纳入230例患者的临床资料。根据胚胎移植日是否使用阿托西班分为阿托西班组和对照组各115例,阿托西班组于移植前30 min静脉推注小剂量阿托西班6.75 mg(0.9 mL),对照组未使用阿托西班。比较2组患者的胚胎种植率、临床妊娠率、异位妊娠率、流产率、早产率和活产率,并对反复种植失败的不同病因(子宫内膜异位症、免疫/凝血异常、不明原因、复合因素和其他因素)进行亚组分析,比较不同亚组人群中阿托西班组与对照组的临床结局。结果:阿托西班组和对照组胚胎种植率、临床妊娠率、异位妊娠率、流产率、早产率和活产率差异均无统计学意义(均P>0.05)。二分类Logistic回归分析结果显示,移植胚胎类型对活产率的影响差异有统计学意义(P=0.001)。对不同病因所致反复种植失败的患者进行亚组分析发现,子宫内膜异位症合并反复种植失败的亚组人群中,使用阿托西班可以显著降低流产率(P=0.036),但不增加活产率(P=0.757)。结论:使用阿托西班不能改善反复种植失败患者冻融胚胎移植周期的临床结局,不提高活产率。不建议无临床指征地使用阿托西班。

Postoperative Complications and Survival Analysis of Surgical Resection for Hilar Cholangiocarcinoma:A Retrospective Study of Fifty-Nine Consecutive Patients

Objective Hilar cholangiocarcinoma(HC)is invariably fatal without surgical resection.The primary aim of the current study was to determine the safety of variable surgical resections for patient with HC and their survival after surgical resection.In addition,prognostic factor for the overall survival was also evaluated.Methods The study included 59 consecutive patients who were newly diagnosed with HC and underwent surgical resections with curative intend between February 2009 and February 2017.Patients were followed up at 3-6 months intervals after hospital discharge.Postoperative complications and overall survival were determined.Associations of clinicopathologic and surgeon-related factors with overall survival were evaluated through univariate analysis and Cox regression analysis.Results Of patients with Bismuth and Corlette(B&C)type HI(n=19)and IV(n=25)HC lesions,33(55.9%)were treated with hilar resection combined with major liver resection(MLR),while the other 11 patients with type HI and IV,and those with type I(n=8)and II(n=7)HC lesions were treated with hilar resection.The overall surgical mortality was 5.1%and surgical morbidity was 35.6%.There was no statistical difference in the mortality between MLR group and hilar resection group(6.1%vs.3.8%;X2=0.703,P=0.145).The median follow-up period was 18 months(range,1-94 months).The 1-,3-,5-year survival rate was 59.3%,36.5%,and 17.7%,respectively.The overall survival after resections was 18 months.In HC patients with B&C type III and IV lesions,the median survival was 23 months for hilar resection with MLR and 8 months for hilar resection alone;the 1-,3-,5-year cumulative survival rate was 63.9%,23.3%,and 15.5%,respectively for hilar resection with MLR,and 11.1%,0,and 0,respectively for hilar resection alone,with significant diflerene observed(HR,9.902;95%CI,2.636-19.571,P=0.001).Four factors were independently associated with overall survival:preoperative serum Cal9-9(HR,7.039;95%CI,2.803-17.678,P<0.001),histopathologic grade(HR,4.964;95%CI,1.046-23.552,?=0.044),surgical margins(P=0.031),andAJCC staging(P=0.015).Conclusions R0 resection is efficacious in surgical treatment of HC.MLR in combination with caudate lobe resection may increase the chance of R0 resection and improve survival of HC patients with B&C type IK and IV lesions.Preoperatively prepared for biliary drainage may ensure the safety of MLR in most HC patients.Novel adjuvant therapies are needed to improve the survival of HC patients with poor prognostic factors.

企业数字化转型与内部收入不平等

企业数字化转型在赋能实现高质量发展的同时,是否有助于改善内部收入分配格局?本文利用中国A股上市公司2009-2020年的数据,从微观层面上研究企业数字化转型与内部收入不平等的关系。研究发现:(1)企业数字化转型与高管薪酬间存在显著的倒U型关系,与普通员工薪酬存在显著的线性关系。使得数字化转型对企业内部收入不平等存在显著的倒U型影响,随着数字化转型的深入推进有利于抑制公司内部收入不平等。该结论在通过工具变量检验、Heckman两步法、PSM倾向匹配以及多种稳健性分析后保持高度稳健;(2)异质性分析结果显示,在民营企业和技术密集型企业中,数字化转型与企业内部收入不平等的倒U型关系更为显著;(3)职工监事对数字化转型与内部收入不平等的倒U型关系具有显著的调节作用。本文研究结论为正确处理数字化转型的技术效率和分配效应提供了新的思路,为促进社会公平和实现共同富裕提供了新的启发。

Influence of chloride salts on hydrogen generation via hydrolysis of MgH_2 prepared by hydriding combustion synthesis and mechanical milling

The effects of chloride salts(NaCl,MgCl2and NH4Cl)on the hydrolysis kinetics of MgH2prepared by hydridingcombustion synthesis and mechanical milling(HCS+MM)were discussed.X-ray diffraction(XRD)analyses show that high-purityMgH2was successfully prepared by HCS.Hydrolysis performance test results indicate that the chloride salt added during the millingprocess is favorable to the initial reaction rate and hydrogen generation yield within60min.A MgH2?10%NH4Cl composite exhibitsthe best performance with the hydrogen generation yield of1311mL/g and a conversion rate of85.69%in60min at roomtemperature.It is suggested that the chloride salts not only play as grinding aids in the milling process,but also create fresh surface ofreactive materials,favoring the hydrolysis reaction.

Interface kinetics modeling of binary alloy solidification by considering correlation between thermodynamics and kinetics

By considering collision-limited growth mode and short-range diffusion-limited growth mode simultaneously,an extended kinetic model for solid−liquid interface with varied kinetic prefactor was developed for binary alloys.Four potential correlations arising from effective kinetics coupling the two growth modes were proposed and studied by application to planar interface migration and dendritic solidification,where the linear correlation between the effective thermodynamic driving force and the effective kinetic energy barrier seems physically realistic.A better agreement between the results of free dendritic growth model and the available experiment data for Ni−0.7at.%B alloy was obtained based on correlation between the thermodynamics and kinetics.As compared to previous models assuming constant kinetic prefactor,a common phenomenon occurring at relatively low undercoolings,i.e.the interface migration slowdown,can be ascribed to both the thermodynamic and the kinetic factors.By considering universality of the correlation between the thermodynamics and kinetics,it is concluded that the correlation should be considered to model the interface kinetics in alloy solidification.

Free dendritic growth model based on nonisothermal interface and microscopic solvability theory

Considering both the effect of nonisothermal nature of the solid/liquid interface and the microscopic solvability theory (MicST), a further improved version of free dendritic growth model for pure materials was proposed. Model comparison indicates that there is a higher temperature at the tip of dendrite predicted by the present model compared with the corresponding model with the isothermal solid/liquid interface assumption. This is attributed to the sidewise thermal diffusion, i.e. the gradient of temperature along the nonisothermal interface. Furthermore, it is indicated that the distinction between the stability criteria from MicST and marginal stability theory (MarST) is more significant with the increase of bath undercoolings. Model test also indicates that the present model can give an agreement with the available experimental data. It is finally concluded that the nonisothermal nature of the solid/liquid interface and the stability criterion from MicST should be taken into account in modeling free dendritic growth.