纯钛表面状态对电解铜箔形核机制的影响

针对钛阴极辊表面电沉积铜箔的高质量要求,主要开展纯钛片晶粒度和表面状态对电解铜箔初始沉积层形核和生长影响规律的研究。形貌和成分分析结果表明,较高的晶粒度更有利于铜核快速形成,铜核优先在缺陷处形成,并逐渐长大连接成片;较大的粗糙度可使铜核快速长大,而随着粗糙度的减小,铜核会在更多的位置形成,但长大后的尺寸减小。电化学分析结果表明,适当粗糙度的钛片具有更高的耐蚀性和电荷转移能力。此外,COMSOL建模结果证明钛片表面的尖端位置具有较高的电流密度与较大的铜箔沉积厚度,电流密度和沉积厚度随着距离钛片表面的尖端位置越远而变得更小。通过研究铜箔初始沉积层的形核和生长机制,可以为钛阴极辊的制备提供理论指导,即增大钛阴极辊的晶粒度、适当减小表面粗糙度和避免尖端区域的形成对于制备厚度均匀、表面平整的电解铜箔至关重要。

PdNiCrBSi合金钎料粉末的制备及钎焊应用研究

针对航空航天钎焊用钎料合金粉末的需求,采用真空感应熔炼气雾化法制备PdNiCrBSi合金钎料粉末,研究了该粉末的物理性质、微观形貌与结构以及在高温合金基材上的钎焊性能。结果表明:PdNiCrBSi粉末主要为球形,由多种物相组成,且在GH3536母材上具有良好的润湿铺展性和可钎焊性。该钎料焊后的焊缝最大拉力38.2~38.9 kN,钎焊接头剪切强度为382~389 MPa,基本与母材强度相近,其断裂方式为脆性断裂。

Transcriptional regulation in the development and dysfunction of neocortical projection neurons

Glutamatergic projection neurons generate sophisticated excitatory circuits to integrate and transmit information among different cortical areas,and between the neocortex and other regions of the brain and spinal cord.Appropriate development of cortical projection neurons is regulated by certain essential events such as neural fate determination,proliferation,specification,differentiation,migration,survival,axonogenesis,and synaptogenesis.These processes are precisely regulated in a tempo-spatial manner by intrinsic factors,extrinsic signals,and neural activities.The generation of correct subtypes and precise connections of projection neurons is imperative not only to support the basic cortical functions(such as sensory information integration,motor coordination,and cognition)but also to prevent the onset and progression of neurodevelopmental disorders(such as intellectual disability,autism spectrum disorders,anxiety,and depression).This review mainly focuses on the recent progress of transcriptional regulations on the development and diversity of neocortical projection neurons and the clinical relevance of the failure of transcriptional modulations.

铜-锌合金电沉积及脱合金化法制备多孔铜箔

[目的]纳米多孔铜由于其开放的多孔结构、较高的比表面积、较低的密度等独特的理化性能,在储能、催化剂、传感器等领域有巨大的应用潜力。为了解决金属锂作为锂离子电池负极材料时存在的锂枝晶及安全问题,采用脱合金化法制备多孔铜箔成为近年来的研究热点。[方法]先以钛板为基体电沉积铜箔基底,接着电沉积Cu-Zn合金,再脱合金化处理得到多孔铜箔。重点研究了工艺参数对Cu-Zn合金镀层形貌、结构和性能的影响。[结果]Cu-Zn合金电沉积的较优工艺条件为:电流密度1.0 A/dm^(2),温度40℃,时间20 min。该条件下所得Cu-Zn合金镀层表面平整、结构均匀、形成单一合金相,经脱合金化处理后Zn元素的去除率为70.6%。[结论]采用电沉积+脱合金化的方法有望制得孔径均匀的多孔铜箔,但会产生裂纹,有待进一步研究和改善。

水溶液体系中制备纳米银线的研究

在水溶液体系中,以蔗糖为还原剂、NaCl为前驱体络合剂、PVP为表面活性剂,通过水热反应制备得到了直径大约为40 nm,线径分布均匀、分散性良好的纳米银线。有效解决了目前多元醇有机体系下制备纳米银线洗涤困难,反应条件苛刻,后处理繁琐等问题。系统研究了还原剂用量、还原剂种类、Cl-/Ag+摩尔比、卤化物种类和表面活性剂种类对于产物形貌的影响。结果表明,当还原剂蔗糖的用量为0.18 g,PVP的相对分子质量为58000,选择NaCl作为络合剂,且Cl-/Ag+摩尔比控制在1.26时,制备的纳米银线形貌均一,纯度较高,纳米线长径比大于1000。

钨铼合金废料电化学溶解研究

为实现钨铼合金废料的快速、高效溶解,采用NaOH碱性体系下电化学溶解W-25Re合金边角料。结果表明:当槽电压2.5 V、NaOH浓度100 g/L、电解温度30~40℃、电溶10 h时,电解溶液含W和Re浓度分别达到46.4和15.4 g/L,此时W和Re的溶出率分别为99.78%和99.35%,阳极电流效率达到98.80%,电溶能耗为2.29 kWh/kg。电溶后阳极经SEM表征,其表面呈现丘陵形貌,EDS分析表明,电溶前后阳极的W/Re质量百分比基本不变,W溶出速率约为Re的3倍。

氩气雾化制备BCo51CrNiSiW合金钎料细粉的研究

采用真空感应熔炼气雾化法制备BCo51CrNiSiW合金钎料粉末,研究了喷嘴结构、雾化压力和导流管直径对细粉收得率的影响,并表征了细粉的成分、微观形貌、组织和熔化温度范围。结果表明,在使用自由落体式喷嘴、雾化压力为3.5 MPa和导流管直径为4 mm的工艺条件下,所制备的合金粉末具有最高的细粉收得率;细粉的粒径大小在(13~75)μm之间,并且成分合格,主要为Co相,球形度和分散性好,内部组织以树枝晶为主;熔化温度在(1073.39~1112.58)℃之间,可作为钴基高温合金钎料。

高温钎料焊膏研究进展

针对高温钎料使用便利性的需求,综述了高温钎料焊膏的相关研究现状。介绍了焊膏各组分在焊膏制备和钎焊中的作用,阐述了镍基、铜基、银基、钛基和金基五种常用高温钎料及其焊膏的应用与发展趋势,为高性能高温钎料焊膏的开发提供了参考。

银铂合金的制备及性能研究

采用真空感应熔炼法制备得到了4种不同铂含量的银铂合金材料。测定了合金的密度并分析其物相,研究了铂含量对铸态银铂合金致密性、组织形貌、晶粒取向和硬度的影响。结果表明,在快速升温和冷却的熔铸条件下,所制备的银铂合金铸锭致密、有光泽;铂含量对银铂合金的组织形貌和性能有着显著的影响,随着铂含量的增大,银铂合金的组织由枝晶变为等轴晶,晶粒更小,且硬度逐渐增大。

换热器用Cu-3Ag-0.5Zr合金板的研制

采用真空感应熔炼+热处理+冷轧的工艺,制备了Cu-3Ag-0.5Zr合金板材。分析了该合金的成分、物相、熔化温度范围和微观组织,并研究了温度对其力学性能和导热性的影响。结果表明,Cu-3Ag-0.5Zr合金板材的成分合格、组织均匀,以置换型固溶体相为主,有少量CuZr相,熔化温度在1042.23℃~1078.86℃之间;随着温度的升高,Cu-3Ag-0.5Zr合金板材的屈服强度和抗拉强度逐渐降低,导热性有小幅度增强。

高强度银铂合金细丝的微观组织与性能

采用孔型轧制和冷拉丝的方式制备了不同铂含量(1%、2%、3%和4%)、不同形变量(70%、79%、87%和93%)的高强度银铂合金细丝。利用光学显微镜、扫描电子显微镜(SEM)、电导率测试仪、显微硬度计、电子万能拉伸试验机等表征了银铂合金细丝的微观组织、力学性能、电学性能,并系统分析了铂含量和形变量对银铂合金细丝微观组织、力学性能、电学性能的影响。结果表明:随着铂含量的增加,银铂合金细丝的纤维化更加明显,晶粒变得窄小,电导率明显降低,抗拉强度在铂含量达到2%后显著提高;随着形变量的增大,纤维更加密集窄小,晶粒变得窄小,电导率基本不变,抗拉强度不断提高。

MicroRNA-155 promotes the pathogenesis of experimental colitis by repressing SHIP-1 expression

AIM To explore the mechanism by which microRNA-155 (miR-155) regulates the pathogenesis of experimental colitis. METHODS A luciferase assay was performed to confirm the binding of miR-155 to the SHIP-1 3'-UTR. MiR-155 mimics, negative controls and SHIP-1 expression/knockdown vectors were established and then utilized in gain-and loss-of-function studies performed in raw264.7 cells and primary bone marrow-derived macrophages (BMDMs). Thereafter, dextran sulfate sodium (DSS)-induced colitis mouse model with or without antagomiR-155 treatment was established, and the levels of miR-155 and SHIP-1, as well as the pro-inflammatory capabilities, were measured by western blot, quantitative polymerase chain reaction, and immunohistochemistry. RESULTS MiR-155 directly bound to the 3'-UTR of SHIP-1 mRNA and induced a significant decrease in SHIP-1 expression in both raw264.7 cells and primary BMDMs. MiR-155 markedly promoted cell proliferation and proinflammatory secretions including IL-6, TNF-alpha, IL-1 beta, and IFN-gamma, whereas these effects could be reversed by the restoration of SHIP-1 expression. In vivo studies showed that antagomiR-155 administration could alleviate DSS-induced intestinal inflammation in Balb/c mice. Moreover, significantly increased SHIP-1 expression, as well as decreased Akt activation and in-flammatory response, were observed in the antagomiR-155-treated mice. CONCLUSION MiR-155 promotes experimental colitis by repressing SHIP-1 expression. Thus, the inhibition of miR-155 might be a promising strategy for therapy.

Effect of Lianshu preparation on lipopolysaccharide-induced diarrhea in rats

AIM： To investigate the effect of Lianshu preparation on lipopolysaccharide （LPS）-induced diarrhea in rats. METHODS： A diarrhea model was established in Sprague Dawley rats via injection of 1 mL of 30 mg/kg LPS. A total of 40 rats were randomly divided into normal group, LPS group, LPS ＋ Lianshu group, LPS ＋ berberine group （n = 10 in each group）. Their intestinal mucosal barrier and frequency of diarrhea were observed. Levels of glucose, serum Na^＋, K^＋, Cl and hematocrit, plasma nitrogen monoxide （NO）, diamine oxidase （DAO）, and D （-）-lactate were measured. The number of IgA＋ plasma cells in small intestine was detected and SIgA levels in the intestinal fluid were measured. The antipyretic activity of Lianshu preparation in rats was evaluated using Brewer＇s yeast-induced pyrexia （10 mL/kg of 20% aqueous suspension）. Acetaminophen （250 mg/kg, intragastric administration, bid） was comparison. Temperature used as a standard drug for was recorded 1 h before and 6 h after Brewer＇s yeast injection. Finally, small intestina transmission in mice treated with Lianshu was detected after intraperitoneal injection of methyl prostigmin （2 mg/kg）. Atropine （10 g/kg） was used as a control. The ink content in intestine was determined and the total length of intestine was measured. RESULTS： The frequency of diarrhea was higher in LPS group than in LPS ＋ Lianshu group and LPS ＋ berberine group （36.70± 5.23 vs 28.50 ±4.06 and 32.70±9.30 respectively, P 〈 0.01）, and lower in LP5 ＋ Lianshu group than in LPS ＋ berberine group （P = 0.03）. The levels of Na＋, glucose, Cl, K^＋ were significantly lower in LPS ＋ Lianshu group than in LPS ＋ berberine group （140.35±3.19 mmol/L vs 131.99±4.86 mmol/L, 8.49 ±1.84 mmol/L vs 6.54±2.30 mmol/L, 106.29± 4.41 mmol/L vs 102.5±1.39 mmol/L, 5.08±0.66 mmol/L vs 4.32 ± 0.62 mmol/L respectively, P 〈 0.05）. The level of hematocrit was lower in LPS ＋ Lianshu group than in LPS ＋ berberine group （0.50% ±0.07% vs 0.59%± 0.10% respectively, P 〈 0.05）. The plasma levels of NO, DAO and D （-）-lactate were higher in LPS group than in normal group （79.74 ± 7.39μmol/L vs 24.94 ± 3.38μmol/L, 2.48 ±0.42μ/mL vs 0.82 ±0.33 p/mL, 5.63± 0.85μg/mL vs 2.01 ±0.32 μg/mL respectively, P 〈 0.01）, and lower in LPS ＋ Lianshu group than in LP5 ＋ berberine group （48.59±4.70μmol/L vs 51.56 ±8.38 μmol/L, 1.43± 0.53μmol/mL vs 1.81 ±0.42 μmol/mL, 4.00± 0.54 μg/mL vs 4.88 ± 0.77 pg/mL respectively, P 〈 0.05）. The morphology of the intestinal mucosa showed destroyed villi in LPS group and atrophied intestinal mucosa in other groups. The pathological intestinal mucosal changes were less in LPS ＋ Lianshu group than in LPS group. The number of IgA＋ plasma cells and amount of SIgA were higher in LPS ＋ Lianshu group than in LPS group （1.16±0.19/μm^2 vs 1.09±0.28/μm^2, P = 0.026; 0.59 ±0.12 mg/L vs 0.15± 0.19 mg/L respectively, P = 0.000）. Lianshu had counteractive effects on yeast-induced pyrexia and enterokinesia in rats. CONCLUSION： Lianshu preparation has therapeutic effects on LPS-induced diarrhea and enterokinesia in rats.

高长径比铜纳米线的简易合成

采用水热法合成了高长径比的铜纳米线,研究了CTAC添加量、NaOH添加量及VC添加量对铜纳米线微观形貌的影响,分析了铜纳米线的纯度。结果表明,在一定范围内增加CTAC的添加量有助于获得一维的铜纳米线,合适的NaOH和VC添加量有助于获得线性较好、分散性优异的铜纳米线。XRD结果证实了所得铜纳米线具有较高的纯度。

Effect of L-cysteine on remote organ injury in rats with severe acute pancreatitis induced by bile-pancreatic duct obstruction

BACKGROUND: Remote organ failure occurs in cases of acute pancreatitis (AP); however, the reports on AP induced by pancreatic duct obstruction are rare. In this study we determined the effect of L-cysteine on pancreaticobiliary inflammation and remote organ damage in rats after pancreaticobiliary duct ligation (PBDL). METHODS: AP was induced by PBDL in rats with 5/0 silk Sixty rats were randomly divided into 4 groups. Groups A and B were sham-operated groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). Groups C and D were PBDL groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). The tissue samples of the pancreas and remote organs such as the lung, liver, intestine and kidney were subsequently examined for pathological changes under a light microscope. The samples were also stored for the determination of malondialdehyde and glutathione levels. Blood urea nitrogen (BUN), plasma amylase, ALT and AST levels were determined spectrophotometrically using an automated analyzer. Also, we evaluated the effect of L-cysteine on remote organ injury in rats with AP induced by retrograde infusion of 3.5% sodium taurocholate (NaTc) into the bile-pancreatic duct. RESULTS: Varying degrees of injury in the pancreas, lung, liver intestine and kidney were observed in the rats 24 hours after PBDL. The severity of injury to the lung, liver and intestine was attenuated, while injury status was not changed significantly in the pancreas and kidney after L-cysteine treatment. Oxidativestress was also affected by L-cysteine in PBDL-treated rats. The concentration of tissue malondialdehyde decreased in the pancreas and remote organs of PBDL and L-cysteine administrated rats, and the concentration of glutathione increased more significantly than that of the model control group. However, L-cysteine administration reduced the severity of injury in remote organs but not in the pancreas in rats with NaTc-induced AP. CONCLUSION: L-cysteine treatment attenuated multiple organ damage at an early stage of AP in rats and modulated the oxidant/antioxidant imbalance.

KMT2D deficiency enhances the anti-cancer activity of L48H37 in pancreatic ductal adenocarcinoma

BACKGROUND Novel therapeutic strategies are urgently needed for patients with a delayed diagnosis of pancreatic ductal adenocarcinoma(PDAC)in order to improve their chances of survival.Recent studies have shown potent anti-neoplastic effects of curcumin and its analogues.In addition,the role of histone methyltransferases on cancer therapeutics has also been elucidated.However,the relationship between these two factors in the treatment of pancreatic cancer remains unknown.Our working hypothesis was that L48H37,a novel curcumin analog,has better efficacy in pancreatic cancer cell growth inhibition in the absence of histonelysine N-methyltransferase 2D(KMT2D).AIM To determine the anti-cancer effects of L48H37 in PDAC,and the role of KMT2D on its therapeutic efficacy.METHODS The viability and proliferation of primary(PANC-1 and MIA PaCa-2)and metastatic(SW1990 and ASPC-1)PDAC cell lines treated with L48H37 was determined by CCK8 and colony formation assay.Apoptosis,mitochondrial membrane potential(MMP),reactive oxygen species(ROS)levels,and cell cycle profile were determined by staining the cells with Annexin-V/7-AAD,JC-1,DCFH-DA,and PI respectively,as well as flow cytometric acquisition.In vitro migration was assessed by the wound healing assay.The protein and mRNA levels of relevant factors were analyzed using Western blotting,immunofluorescence and real time-quantitative PCR.The in situ expression of KMT2D in both human PDAC and paired adjacent normal tissues was determined by immunohistochemistry.In vivo tumor xenografts were established by injecting nude mice with PDAC cells.Bioinformatics analyses were also conducted using gene expression databases and TCGA.RESULTS L48H37 inhibited the proliferation and induced apoptosis in SW1990 and ASPC-1 cells in a dose-and time-dependent manner,while also reducing MMP,increasing ROS levels,arresting cell cycle at the G2/M stages and activating the endoplasmic reticulum(ER)stress-associated protein kinase RNA-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/activating transcription factor 4(ATF4)/CHOP signaling pathway.Knocking down ATF4 significantly upregulated KMT2D in PDAC cells,and also decreased L48H37-induced apoptosis.Furthermore,silencing KMT2D in L48H37-treated cells significantly augmented apoptosis and the ER stress pathway,indicating that KMT2D depletion is essential for the anti-neoplastic effects of L48H37.Administering L48H37 to mice bearing tumors derived from control or KMT2Dknockdown PDAC cells significantly decreased the tumor burden.We also identified several differentially expressed genes in PDAC cell lines expressing very low levels of KMT2D that were functionally categorized into the extrinsic apoptotic signaling pathway.The KMT2D high-and low-expressing PDAC patients from the TCGA database showed similar survival rates,but higher KMT2D expression was associated with poor tumor grade in clinical and pathological analyses.CONCLUSION L48H37 exerts a potent anti-cancer effect in PDAC,which is augmented by KMT2D deficiency.

Comparison of nominal and standardized catch per unit effort data in quantifying habitat suitability of skipjack tuna in the equatorial Pacific Ocean

In the western and central Pacific Ocean,upper strata waters exhibit highly dynamic oceanographic features under ENSO variability.This has been proved to be responsible for the dynamic change of both abundance and zonal distribution of skipjack tuna(Katsuwonus pelamis).Although causality has been suggested by researchers using physical-biological interaction models,cumulative evidence needs to be obtained and the tenability of assertion needs to be tested from an ecological habitat perspective,based on fisheries data.For purse seine fishery,the use of catch per unit effort(CPUE)as an indication of the abundance is confusing because of technical improvements over the whole exploitation history and unbalanced individual fishing characteristic of vessels.It is particularly interesting to discriminate between habitat characteristics in comparative scenarios of CPUE application.This study identified habitat traits based on a series of oceanographic factors from a global ocean reanalysis model.A comparison was conducted between two habitat models based on unprocessed purse seine CPUE and standardized CPUE considering fishing characteristics.The results suggest that standardized CPUE could model the regular zonal shift of habitat compatible with the observed fishing efforts transfer,and achieved better prediction capacity than unprocessed CPUE.Furthermore,the habitat of skipjack tuna was also characterized and linked with surface and subsurface thermal environment,ocean current,dissolved oxygen,biotic environment,and ENSO variability.The monthly-averaged habitat suitable index,derived from the optimal habitat model prediction,showed a significant linear relationship with the southern oscillation index,which suggested that El Ni?o episodes eventually provide more preferable habitat for skipjack tuna under ENSO variability.

氩气雾化制备Ti60CuNiCr合金钎料粉末及其性能研究

采用氩气雾化法制备了Ti60CuNiCr合金钎料粉末,表征了细粉的收得率、微观形貌、组织和成分,研究了该钎料粉末在纯Ti和Ti2AlNb两种基体上的流动性。结果表明,正200目Ti60Cu Ni Cr合金钎料细粉的收得率大于50%,细粉具有较高的球形度、均匀的成分,以纯Ti相为主,在纯Ti和Ti1AlNb两种基材上均有优异的流动性。

钯含量对银铜钯合金箔带钎料性能的影响

钎焊是一种常用的金属连接方法,然而钎焊过程中产生的一些不良现象,如氧化膜、气孔等,影响了合金钎焊料的质量和可靠性。本论文旨在探讨钯对银铜钯箔带合金钎焊清洁性的影响,并寻找提高其清洁性的方法。通过实验研究和分析,发现添加钯银铜钯合金钎料能够有效减少氧化膜的生成,并提高钎焊接头的力学性能和界面的稳定性。钯银铜合金箔带的钎焊接头在气孔方面也呈现出明显的改善。此外,钯的添加还能够改善钎焊接头的焊接质量,为箔带材合金钎料的广泛应用提供了有力支持。

BNi52MnCoNbSiFeB合金钎料粉末的制备与性能研究

采用真空感应熔炼结合气雾化的方式制备BNi52MnCoNbSiFeB合金钎料粉末,分析了不同粒径粉末的微观形貌与组织,表征了该合金钎料粉末的成分和熔化温度。结果表明,通过精确控制熔炼和雾化工艺,可以得到分散性较好、球形度高、成分可控和熔化温度范围小的BNi52MnCoNbSiFeB合金钎料粉末。