Formation and transformation of metastable LPSO building blocks clusters in Mg-Gd-Y-Zn-Zr alloys by spinodal decomposition and heterogeneous nucleation

To study the formation and transformation mechanism of long-period stacked ordered(LPSO)structures,a systematic atomic scale analysis was conducted for the structural evolution of long-period stacked ordered(LPSO)structures in the Mg-Gd-Y-Zn-Zr alloy annealed at 300℃~500℃.Various types of metastable LPSO building block clusters were found to exist in alloy structures at different temperatures,which precipitate during the solidification and homogenization process.The stability of Zn/Y clusters is explained by the first principles of density functional theory.The LPSO structure is distinguished by the arrangement of its different Zn/Y enriched LPSO structural units,which comprises local fcc stacking sequences upon a tightly packed plane.The presence of solute atoms causes local lattice distortion,thereby enabling the rearrangement of Mg atoms in the different configurations in the local lattice,and local HCP-FCC transitions occur between Mg and Zn atoms occupying the nearest neighbor positions.This finding indicates that LPSO structures can generate necessary Schockley partial dislocations on specific slip surfaces,providing direct evidence of the transition from 18R to 14H.Growth of the LPSO,devoid of any defects and non-coherent interfaces,was observed separately from other precipitated phases.As a result,the precipitation sequence of LPSO in the solidification stage was as follows:Zn/Ycluster+Mg layers→various metastable LPSO building block clusters→18R/24R LPSO;whereas the precipitation sequence of LPSO during homogenization treatment was observed to be as follows:18R LPSO→various metastable LPSO building block clusters→14H LPSO.Of these,14H LPSO was found to be the most thermodynamically stable structure.

Asymptotic analysis on bright solitons and breather solutions of a generalized higher-order nonlinear Schrödinger equation in an optical fiber or a planar waveguide

We study a generalized higher-order nonlinear Schr¨odinger equation in an optical fiber or a planar waveguide.We obtain the Lax pair and N-fold Darboux transformation(DT)with N being a positive integer.Based on Lax pair obtained by us,we derive the infinitely-many conservation laws.We give the bright one-,two-,and N-soliton solutions,and the first-,second-,and Nth-order breather solutions based on the N-fold DT.We conclude that the velocities of the bright solitons are influenced by the distributed gain function,g(z),and variable coefficients in equation,h1(z),p1(z),r1(z),and s1(z)via the asymptotic analysis,where z represents the propagation variable or spatial coordinate.We also graphically observe that:the velocities of the first-and second-order breathers will be affected by h1(z),p1(z),r1(z),and s1(z),and the background wave depends on g(z).

Licorice-saponin A3 is a broad-spectrum inhibitor for COVID-19 by targeting viral spike and anti-inflammation

Currently,human health due to corona virus disease 2019(COVID-19)pandemic has been seriously threatened.The coronavirus severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spike(S)protein plays a crucial role in virus transmission and several S-based therapeutic approaches have been approved for the treatment of COVID-19.However,the efficacy is compromised by the SARS-CoV-2 evolvement and mutation.Here we report the SARS-CoV-2 S protein receptor-binding domain(RBD)inhibitor licorice-saponin A3(A3)could widely inhibit RBD of SARS-CoV-2 variants,including Beta,Delta,and Omicron BA.1,XBB and BQ1.1.Furthermore,A3 could potently inhibit SARS-CoV-2 Omicron virus in Vero E6 cells,with EC50 of 1.016μM.The mechanism was related to binding with Y453 of RBD determined by hydrogen-deuterium exchange mass spectrometry(HDX-MS)analysis combined with quantum mechanics/molecular mechanics(QM/MM)simulations.Interestingly,phosphoproteomics analysis and multi fluorescent immunohistochemistry(mIHC)respectively indicated that A3 also inhibits host inflammation by directly modulating the JNK and p38 mitogen-activated protein kinase(MAPK)pathways and rebalancing the corresponding immune dysregulation.This work supports A3 as a promising broad-spectrum small molecule drug candidate for COVID-19.

A solution method for decomposing vector fields in Hamilton energy

Hamilton energy,which reflects the energy variation of systems,is one of the crucial instruments used to analyze the characteristics of dynamical systems.Here we propose a method to deduce Hamilton energy based on the existing systems.This derivation process consists of three steps:step 1,decomposing the vector field;step 2,solving the Hamilton energy function;and step 3,verifying uniqueness.In order to easily choose an appropriate decomposition method,we propose a classification criterion based on the form of system state variables,i.e.,type-I vector fields that can be directly decomposed and type-II vector fields decomposed via exterior differentiation.Moreover,exterior differentiation is used to represent the curl of low-high dimension vector fields in the process of decomposition.Finally,we exemplify the Hamilton energy function of six classical systems and analyze the relationship between Hamilton energy and dynamic behavior.This solution provides a new approach for deducing the Hamilton energy function,especially in high-dimensional systems.

A sub-grid scale model for Burgers turbulence based on the artificial neural network method

The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neuralnetwork and deep learning method.The filtered data of the direct numerical simulation is used to establish thetraining data set,the validation data set,and the test data set.The artificial neural network(ANN)methodand Back Propagation method are employed to train parameters in the ANN.The developed ANN is applied toconstruct the sub-grid scale model for the large eddy simulation of the Burgers turbulence in the one-dimensionalspace.The proposed model well predicts the time correlation and the space correlation of the Burgers turbulence.

High-strength antiswelling adhesive achieves both hemostasis and wound healing

Skin is one of the most vulnerable tissues,but there is a lack of injectable bioactive hydrogel dressings,which possess high strength,antiswelling capacity,and wet tissue adhesiveness,but also a rapid gelling process to enable rapid hemostasis,sutureless wound closure,and scarless healing of infected skin wounds[1e5].A new injectable,antibacterial,and multifunctional hydrogel dressings based on poly(citric acid-co-polyethylene glycol)-g-dopamine(PCPD)and amino-terminated Pluronic F127(APF)mi-celles loaded with astragaloside IV(AS)was developed for this pur-pose,as shown in Fig.1A[6].

Luspatercept enhances hemoglobin levels in a Chinese boy with congenital sideroblastic anemia:A case report

BACKGROUND Congenital sideroblastic anemia(CSA)is a rare and heterogeneous group of genetic disorders.Conventional treatment include pyridoxine(vitamin B6)and allogeneic hematopoietic stem cell transplantation(allo-HSCT),and can alleviate anemia in the majority of cases.Nevertheless,some CSA cases remain unresponsive to pyridoxine or are unable to undergo allo-HSCT.Novel management approaches is necessary to be developed.To explore the response of luspatercept in treating congenital sideroblastic anemia.CASE SUMMARY We share our experience in luspatercept in a 4-year-old male patient with CSA.Luspatercept was administered subcutaneously at doses of 1.0 mg/kg/dose to 1.25 mg/kg/dose every 3 wk,three consecutive doses,evaluating the hematological response.Luspatercept leading to a significant improvement in the patient's anemia.The median hemoglobin during the overall treatment with three doses of luspatercept was 90(75-101)g/L,the median absolute reticulocyte count was 0.0593(0.0277-0.1030)×10^(12)/L,the median serum ferritin was 304.3(234.4-399)ng/mL,and the median lifespan of mature red blood cells was 80(57-92)days.Notably,no adverse reactions,such as headaches,dizziness,vomiting,joint pain,or back pain,were observed during the treatment period.CONCLUSION We believe that luspatercept might emerge as a viable therapeutic option for the maintenance treatment of CSA or as a bridging treatment option before hematopoietic stem cell transplantation.

A case of primary angiitis of the central nervous system diagnosed and treated based on HR-MRI

Objective:To summarize the clinical features,imaging manifestations,therapeutic options,and prognosis of the primary angiitis of the central nervous system(PACNS)and to explore the role of high-resolution magnetic resonance imaging(HR-MRI)in the PACNS diagnosis and treatment.Methods:One patient with PACNS treated by HR-MRI was retrospectively analyzed and summarized by combining relevant literature.Results:The patient was a young female who was hospitalized with progressive cerebral infarction and multiple intracranial arterial stenosis.HR-MRI indicated vasculitic changes.After excluding other diseases,hormone shock combined with immunosuppression was given,followed by long-term rehabilitation treatment.The patient’s condition tended to stabilize,and the prognosis was satisfactory.Conclusion PACNS is challenging to diagnose and is characterized by poor prognosis and easy recurrence.HR-MRI plays an important role in the clinical diagnosis and treatment adjustment for PACNS.

复方血栓通胶囊对高海拔视网膜病变大鼠的保护作用

目的:探讨复方血栓通胶囊对高海拔视网膜病变大鼠的保护作用及其作用机制。方法:雄性SD大鼠24只随机分为6组,分别饲养于模拟高海拔5000m的高原舱内2、4、6、10、24、72h,观察各组大鼠视网膜组织形态,HIF-1α的表达和入舱前后大鼠视网膜电图中暗适应最大反应b波振幅的变化;雄性SD大鼠24只随机分为4组,分别予安慰剂,大花红景天口服液,肌苷片及复方血栓通胶囊灌胃喂药7d后,饲养于模拟海拔为5000m模拟舱内10h,观察各组大鼠视网膜组织形态,HIF-1α的表达和入舱前后大鼠视网膜电图中暗适应最大反应b波振幅的变化。结果:高海拔视网膜病变SD大鼠模型中,结果显示随着各实验时间的增加,神经节细胞层细胞肿胀明显,HIF-1α在神经节细胞及内核层细胞胞浆表达增高,均在10h时最为明显。各组SD大鼠进舱自身前后F-ERG暗适应最大反应b波振幅变化分析,4、6、10、72h组F-ERG暗适应最大反应b波振幅显著降低(P<0.05);2h组和4h组(P=0.007)、6h组(P=0.008)、10h(P=0.002)有差异,24h组和4h组(P=0.035)、6h(P=0.040)、10h组(P=0.012)有差异。复方血栓通对SD大鼠高海拔视网膜病变预防作用研究中,结果显示与安慰剂组相比较,复方血栓通组、红景天组及肌苷组的视网膜水肿均明显减轻,但复方血栓通组与红景天组视网膜水肿程度明显低于肌苷组;复方血栓通组及红景天组HIF-1α在神经节细胞层及内核层表达明显下降;各组SD大鼠进舱后F-ERG暗适应最大反应b波振幅比较显示,安慰剂组与复方血栓通组(P=0.032),红景天组(P=0.001)均有差异。结论:在模拟高海拔环境下,复方血栓通可能是通过抑制HIF-1α的表达对大鼠高海拔视网膜病变有保护作用,但是具体作用机制有待我们进一步研究。

High Temperature Rheological Performance of Graphene Modified Rubber Asphalt

To elucidate the high temperature rheological capability of graphene modified rubber asphalt,three contents of graphene and crumb rubber were prepared by a combination of mechanical agitation and high speed shearing machine,then used dynamic shear rheological test(DSR)and multiple stress creep recovery(MSCR)tests to evaluate.The hardness and softening point with rotational viscosity of samples raised with the addition of graphene,especially the addition of 0.04%.Dynamic shear rheological test revealedthat the dynamic shear modulus G*,rutting factor G*/Sin δ,and zero shear viscosity(ZSV)of graphene-modified rubber asphalt were greatly influenced along with graphene-increased,on the contrary,phase angle δ which characterize the viscoelastic ratio of asphalt decreased.Multiple stress creep recovery(MSCR)tests showed that the graphene-enhanced rubber asphalt had high-temperature stability through non-recoverable creep compliance(Jnr).Based on these findings,graphene-modified rubber asphalt binders with the addition of 0.04% graphene had good viscoelastic properties as well as high temperature rutting resistance performance.In the meantime,G*/Sin δ,ZSV,and Jnr100,Jnr3200 have good correlation,which can reveal the excellent high-temperature stability performance of asphalt.

酯交换法合成聚碳酸酯催化剂性能考察

以双酚A和碳酸二苯酯为原料,采用非光气熔融酯交换法合成聚碳酸酯。考察了氢氧化钾、氢氧化钠、四丁基氢氧化铵、碳酸钠、吡啶以及复合催化剂对聚碳酸酯合成反应速率及聚碳酸酯分子量和色差的影响。研究表明,氢氧化钾作为催化剂较适合于聚碳酸酯合成工艺,使用复合催化剂可以得到分子量较高、色差较低的聚碳酸酯。

脆性X智力低下蛋白参与非编码RNA通路的研究进展

脆性X综合征(Fragile X syndrome)是一种最常见的遗传性智力低下疾病,并且伴有语言和行为障碍等。该疾病是由脆性X智力低下基因(Fragile X mental retardation 1,FMR1)突变而导致脆性X智力低下蛋白(Fragile X mental retardation protein,FMRP)表达异常造成的。近年来,研究发现FMRP参与非编码RNA通路,并发挥多种重要生物学功能,这对理解脆性X综合征发病机理具有重要的推动作用。首先发现FMRP与siRNA和miRNA通路中Dicer酶、Ago1和Ago2蛋白相互作用,参与神经活动及生殖干细胞命运决定等重要过程。随后又发现FMRP与piRNA通路中Aub、Ago1和Piwi蛋白相互作用,维持了染色体正常结构和基因组稳定性。最新研究结果发现FMRP与lncRNA相互作用,其功能和价值正引起关注。本文从FMRP与非编码RNA通路的关系展开,着重介绍了FMRP与piRNA之间的相互作用,以期为深入理解非编码RNA通路在脆性X综合征的发病过程中作用提供参考,同时期望与临床医学领域尽快形成交叉研究,早日促进理论成果转化为临床应用。

脉冲式加热炉水梁结瘤的分析和预防

为了进一步降低加热炉的燃耗和烧损,加热炉的燃烧控制模式从蓄热式改进为脉冲式。此项改进后,步进梁上开始出现结瘤,板坯在炉内走斜,并导致板坯变形,使轧机无法进行轧制。为解决脉冲式加热炉水梁结瘤的问题,通过分析结瘤成分、探究结瘤产生机理,并采取了相应的预防措施,成功解决了结瘤问题。

Operating Room Nurses’ Role in Multidisciplinary Surgical Coordination for a Patient with a Large Abdominal Tumor and Multiple Pelvic Fractures

In this study,we have summarized the coordination of operating room nurses participating in the multidisciplinary team in diagnosing and treating a patient with a large abdominal tumor and multiple pelvic fractures.To perform surgical treatment on patients with various conditions,it is crucial to consider the patients from a holistic perspective.Thus,the existing medical model has shifted from a“disease-centered”approach focusing on single-disciplinary diagnosis and treatment,to a“patient-centered”approach that involves multiple disciplines in diagnosis and therapy.Operating room nurses,as crucial collaborators of surgeons,should make necessary adjustments to enhance their comprehension of patients,improving the overall quality of surgical coordination.

不同过渡金属原子掺杂硅团簇效应的研究

持续的微电子技术小型化的趋势引发了对纳米结构构建的追求,硅基团簇的性质因其在应用科学和基础科学中的重要性而备受关注。掺入金属原子或氢化可以使悬空键饱和并诱导笼状硅簇的形成。不同的过渡金属掺杂使硅团簇具有了不同的效应。为了寻找能够比较稳定地存在于半导体材料的过渡金属元素,本文详细介绍和比较了不同的过渡金属掺杂对主硅团簇的影响,包括磁效应、稳定结构效应、电子结构效应。

亚硝酸盐对鱼类生长的影响

亚硝酸盐是铵氧化成硝酸盐过程的一个中间产物,水体中亚硝酸盐的存在将会对淡水鱼类的生长产生严重的威胁。本文对水体中亚硝酸盐的来源、吸收机制、生理影响、毒性及解毒机制等方面进行了阐述,以便人们对亚硝酸盐对鱼类生长的影响有一个深刻的了解。

水体中亚硝酸盐的来源与去除

亚硝酸盐是自然界中氮循环的一个中间产物,广泛存在于水体中,其生物毒性越来越受到人们的关注。本文阐述了水体中亚硝酸盐的来源、影响因素以及去除技术,并指出了解决水体中亚硝酸盐的现实意义。

用于医疗器械快速灭菌的低温等离子体装置研究

现有低温等离子体技术存在放电范围小、放电电压高等局限性,不适用于大尺寸医疗器械的消毒灭菌。本文研制了一种灭菌装置,在较低击穿电压下(大气压氦气325 V,大气压空气585 V)产生了大面积等离子体,且创新性地在印刷电路板上实现了气体放电。通过COMSOL等离子体仿真以及实际放电实验,同时实现了低气压与大气压环境下的均匀辉光放电,放电实验结果表明:相对气压在-70~-50 kPa范围内,击穿电压值最低。通过灭菌实验,验证了此灭菌装置产生等离子体的灭菌效能,并对影响灭菌效果的因素进行了探究,灭菌实验结果表明:电源频率是影响灭菌效果的最关键因素,灭菌时间其次,氦气气压对灭菌效果影响最小。对于一定浓度的大肠杆菌,6 min即可达到完全灭菌。

抗VEGF联合激光治疗重度非增殖期糖尿病视网膜病变对黄斑区血流密度的影响

目的:探讨抗血管内皮生长因子(VEGF)联合全视网膜光凝术(PRP)治疗重度非增殖期糖尿病视网膜病变(sNPDR)合并黄斑水肿(DME)对黄斑区血流密度变化的影响。方法:回顾性选取2018-10/2019-04在我院确诊的sNPDR合并DME患者30例30眼,根据治疗方案进行分组,其中A组15例15眼采用“1+PRN”方案采用玻璃体腔内注射雷珠单抗7d后行PRP治疗,B组15例15眼采用单纯PRP治疗。对比两组治疗前后黄斑区6mm×6mm浅层毛细血管(SCP)和深层毛细血管(DCP)血流密度、黄斑中心凹厚度(CMT)、最佳矫正视力(BCVA)变化情况。结果:与术前相比,A组患者术后2wk,1mo DCP血流密度显著增加、CMT明显降低、BCVA明显改善(均P<0.05),B组患者术后1mo CMT降低、BCVA改善(均P<0.05)。术后2wk、1mo,A组患者DCP血流密度较B组明显增加(43.37%±2.72%vs 41.03%±2.60%,45.01%±2.28%vs 41.20%±2.43%,均P<0.05),CMT较B组明显降低(303.4±30.36μm vs 329.60±31.47μm,268.67±30.27μm vs 319.40±28.63μm,均P<0.05),BCVA(LogMAR)较B组明显改善(0.28±0.11 vs 0.40±0.13,0.23±0.14 vs 0.38±0.15,均P<0.05)。结论:抗VEGF联合PRP治疗sNPDR合并DME患者短期内可有效增加DCP血流密度,减轻黄斑水肿,改善视力。

石墨烯基二氧化碳电化学还原催化剂的研究进展

利用电催化技术将CO_(2)转化为小分子燃料或高值化学品是实现原子经济、构建人工碳循环的绿色能源技术之一。电催化还原CO_(2)(ECR)的反应条件温和、产物多样(C_(1)、C_(2)和C_(2+)),有极大的发展潜力。然而,ECR技术面临一些需要解决的挑战性问题,包括电极过电势高、C_(2)及C_(2+)产物选择性低、伴随析氢反应等。解决这些问题的关键在于创制低成本、高性能电催化剂。近年来,石墨烯基电催化剂的研究成为ECR领域的热点之一,原因包括:1)在电化学环境中稳定性好;2)表面原子、电子结构可调,进而实现材料催化活性的调控;3)维度可调,易暴露较大的比表面积和形成层次孔结构;4)耦合石墨烯的高导电性与特定材料的高活性,可协同提升ECR催化性能。本文评述了石墨烯基材料在ECR中的研究进展,详述了石墨烯基电催化剂的构筑方法,探讨并梳理了石墨烯的点/线缺陷、表面官能团、掺杂原子构型、金属单原子种类、材料表界面性质等与ECR性能之间的本征构效关系。最后展望了石墨烯基催化剂在ECR领域中的挑战和未来发展。