一株石韦内生真菌S-34的鉴定及其代谢物检测与分析

以药用植物有柄石韦叶为材料,采用组织块法与微量稀释法分离并筛选出一株具有抑菌活性的内生真菌S-34。经形态学观察、ITS测序与序列比对鉴定内生真菌S-34为链格孢属(Alternaria sp.)。进一步利用GC-MS对其代谢物进行检测与分析,结果显示:内生真菌S-34发酵液乙酸乙酯提取物的抑菌成分主要为氟苯甲酸(20.86%)、苯乙醇(4.89%)、2,3-丁二醇(3.64%),菌体乙酸乙酯提取物的抑菌成分主要为苯甲醛(2.27%)、亚麻醇(2.53%)、亚油酸单甘油酯(1.69%)、亚麻酰氯(9.28%)、反式角鲨烯(7.26%)、麦角甾醇(2.78%)。研究表明,有柄石韦内生真菌S-34的代谢物中蕴藏着较为丰富的抑菌活性物质,是开发天然药物的潜在资源。     

AM-DMMC双水相共聚体系的制备及其影响因素

在聚乙二醇20000(PEG)水溶液中,以(2-甲基丙烯酰氧乙基)三甲基氯化铵(DMMC)和丙烯酰胺(AM)为单体原料、聚(2-甲基丙烯酰氧乙基)三甲基氯化铵(PDMC)为稳定剂,制备了稳定型阳离子聚丙烯酰胺(CPAM)双水相体系。重点探讨了阳离子单体DMMC浓度、分散介质PEG浓度和稳定剂PDMC用量对体系的黏度及共聚物相对分子质量的影响,并利用激光粒度仪测定了共聚物颗粒大小及其粒度分布。结果表明,CPAM双水相聚合体系能避免分散聚合黏度剧增的过程,反应始终平稳进行。制备稳定CPAM双水相体系的适宜条件是:w(DMMC)为8%～15%(单体)、w(PEG)为15%～25%、w(PDMC)为0.5%～1.0%。     

ICP-MS测定罗库溴铵原料药中11种元素杂质含量

建立电感耦合等离子体质谱（ICP-MS）法测定罗库溴铵原料药中汞(Hg)、镉(Cd)、钴(Co)、铅(Pb)、钒(V)、砷(As)、镍(Ni)、铜(Cu)、锂(Li)、锑(Sb)、硼(B) 11个元素杂质含量,并对所建立的方法进行方法学验证。验证结果表明,11个元素标准曲线的相关系数均大于0.999;加样回收率在92.6%～108.2%之间;重复性试验RSD为2.0%～6.4%(n=6);进样精密度试验RSD为1.9%～6.3%;5 h内测定结果的RSD为2.2%～7.7%,均满足《中华人民共和国药典》（2020年版）9101分析方法验证指导原则要求。样品中各元素杂质含量远小于其限度值。     

甲磺酸体系电沉积法制备电沉积铜用新型铅合金阳极材料性能研究

通过电化学方法研究甲基磺酸体系中电沉积得到的纯Pb、Pb-Sn(0.6%)和Pb-Sn(0.6%)-Sb(0.6%)(均为质量分数)合金阳极在CuSO4-H2SO4体系下的电化学性能,结果表明新型的Pb-Sn(0.6%)-Sb(0.6%)合金阳极电催化性能和耐蚀性能均比Pb-Sn(0.6%)和纯Pb阳极优异。采用扫描电子显微镜观察了3种合金材料极化24h后的表面形貌,图像显示纯Pb表面疏松多孔,大部分区域出现了裂纹,Pb-Sn(0.6%)和Pb-Sn(0.6%)-Sb(0.6%)合金阳极表面形貌比较均匀和致密。X射线衍射表明,Pb-Sn(0.6%)和Pb-Sn(0.6%)-Sb(0.6%)合金材料对应的PbO2和PbO的衍射峰比纯Pb强,且Pb-Sn(0.6%)-Sb(0.6%)阳极材料PbO2的衍射峰最强,说明Pb-Sn(0.6%)-Sb(0.6%)阳极的导电性最好。     

高CO2短时处理对茎瘤芥采后衰老的影响

目的以茎瘤芥为试材,研究不同浓度的高CO2短时处理对新鲜茎瘤芥采后衰老的影响。方法将预冷后的茎瘤芥分别充入CO2(30%)+N2(70%),CO2(40%)+N2(60%),CO2(50%)+N2(50%)等3种混合气体(均用体积分数表示),以相同条件下充入空气的处理作为对照,然后置于温度为(4±1)℃、相对湿度为90%~95%的气候箱中处理48 h。结束处理的茎瘤芥用厚度为0.03 mm的聚乙烯袋包装,置于温度为(4±1)℃、相对湿度为90%~95%的条件下贮藏,定期测定其呼吸强度、衰老相关酶活性、VC含量等指标。结果高CO2(30%,40%,50%)短时处理可有效降低茎瘤芥的呼吸强度,高CO2(30%,40%)处理使贮藏后期的茎瘤芥果皮保持了较高的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,同时抑制了果皮过氧化物酶(POD)、多酚氧化酶(PPO)活性上升和果皮VC含量的降低,高CO2(40%)短时处理效果最明显;高CO2处理对于茎瘤芥果肉衰老相关指标无显著影响。结论高CO2(40%)短时处理能有效延缓茎瘤芥采后衰老进程,保鲜效果最好。     

PBS-PPS生物降解聚酯的合成与降解性能EI北大核心CSCD

以癸二酸1,3-丙二醇酯(PPS)预聚物为软段,丁二酸丁二醇酯(PBS)预聚物为硬段,通过直接缩聚方式,合成了一系列聚(丁二酸丁二醇酯癸二酸1,3-丙二醇酯)嵌段共聚物(PBS-PPS)。通过红外光谱(IR)、核磁共振(1H-NMR)、差示扫描量热(DSC)、凝胶色谱(GPC)和扫描电镜(SEM)对产物进行了表征,研究了物料配比对共聚物的结晶性、热性能和降解性的影响。结果表明,合成产物为典型的聚酯结构,随着PPS链段的增加,共聚物的结晶度下降,PBS为68.00%,而PBS-PPS10∶3仅为35.50%;质量损失率增加,PBS在酶解液中10周内质量损失率为27%,而PBS-PPS10∶3为71%;相对分子质量降低程度增大,PBS下降了35%,而PBS-PPS10∶3为81%;共聚物表面形态的破坏程度和酯键的水解程度也有显著提高。     

铜铟硫纳米粒子对钙钛矿太阳能电池性能的影响

为克服钙钛矿太阳能电池滞后效应,本文通过热注射法制得CuInS_2纳米粒子,将其以0.01%(摩尔比例)掺入甲胺/甲脒(FAPbI_3)_x(MAPbCl_3)_(1-x)混合钙钛矿中制备吸光层,并组装正向平面异质结钙钛矿太阳能电池,掺杂CuInS_2器件的正向扫描光电转化效率达15.66%,反向扫描结果达15.36%,两者仅相差1.95%;而未经掺杂的器件正向扫描光电转化效率为15.14%,反向扫描结果为13.58%,两者相差11.49%。结果表明,在(FAPbI_3)_x(MAPbCl_3)_(1-x)混合钙钛矿吸光层中掺杂CuInS_2有利于相应器件磁滞效应等各项性能的提升。     

毛细管气相色谱法测定水产品中多种有机磷农药残留的研究

建立了固相萃取-气相色谱法同时测定水产品中16种有机磷农药的多残留检测分析方法。样品经乙腈水溶液均质提取,利用盐析作用分离出乙腈层,应用C18和PSA串联柱净化后用GC-FPD检测分析,采用外标法定量。方法的检出限(S/N=3)为(0.003～0.006)mg/kg,加标水平为0.01 mg/kg时,方法回收率为(52.8～117)%,相对标准偏差为(4.0～11.5)%;加标水平为0.02 mg/kg时,方法回收率为(54.1～112)%,相对标准偏差为(3.1～10.4)%。     

壳聚糖接枝共聚制备高吸水性树脂的研究

以壳聚糖(CTS),丙烯酸(AA),丙烯酰胺(AM)为原料,N,N-亚甲基双烯酰胺(MBAM)为交联剂,NaH-SO3/K2S2O8氧化还原体系为引发剂,通过接枝共聚合反应制备高吸水性树脂。较佳制备条件为:m(CTS)∶m(AA)∶m(AM)为1∶3∶1,丙烯酸的中和度为70%,引发剂用量4%,交联剂用量0.04%,反应温度45℃。研究表明,此条件下所得树脂吸水率为402g/g,吸盐水(浓度0.9%)率为102g/g,并最后采用红外光谱、扫描电镜表征分析了树脂的结构。     

浊点萃取-高效液相色谱法同时测定烟用接装纸中可萃取Cr(Ⅲ)和Cr(Ⅵ)

建立同时测定烟用接装纸中可萃取Cr(Ⅲ)和Cr(Ⅵ)的方法——浊点萃取-高效液相色谱法（cloudpoint extraction-high performance liquid chromatography,CPE-HPLC）。该方法用超纯水超声萃取接装纸样品30 min,pH为5.0,温度55℃条件下,以吡咯烷二硫代甲酸铵(ammonium pyrrolidine dithiocarbamate,APDC)为螯合剂,曲拉通(Triton)X-114非离子表面活性剂为萃取剂,同时富集溶液中的Cr(Ⅲ)和Cr(Ⅵ),用HPLC分离并测定。结果显示,Cr(Ⅲ)回收率为96.2%～103.6%,RSD为4.6%～7.1%,Cr(Ⅵ)回收率为94.7%～104.4%,RSD为4.3%～8.5%,Cr(Ⅲ)和Cr(Ⅵ)的富集因子分别为15.3和20.1,检出限分别为14μg/kg和10μg/kg。该方法检测灵敏度高,检出限低,稳定性好,具有良好的精密度、回收率和较高的富集倍数,适用于烟用接装纸中可萃取Cr(Ⅲ)和Cr(Ⅵ)的同时测定。     

Two-layered dissolving microneedles for percutaneous delivery of sumatriptan in rats

A novel transdermal delivery of sumatriptan (ST) was attempted by application of dissolving microneedle (DM) technology. Dextran DM (d-DM) and hyaluronate DM (h-DM) were prepared by adding ST solution to dextran solution or hyaluronic acid solution. One DM chip, 1.0?×?1.0?cm, contains 100 microneedle arrays in a 10?×?10 matrix. The mean lengths of DMs were 496.6?±?2.9 μm for h-DM and 494.5?±?1.3 μm for d-DM. The diameters of the array basement were 295.9?±?3.9 μm (d-DM) and 291.7?±?3.0 μm (h-DM), where ST contents were 31.6?±?4.5?μg and 24.1?±?0.9?μg. These results suggest that ST was stable in h-DM. Each DM was administered to rat abdominal skin. The maximum plasma ST concentrations, Cmax, and the areas under the plasma ST concentration versus time curves (AUC) were 44.6?±?4.9?ng/ml and 24.6?±?3.9?ng · h/ml for h-DM and 38.4?±?2.7?ng/ml and 14.1?±?1.5?ng · h/ml for d-DM. The bioavailabilities of ST from DMs were calculated as 100.7?±?18.8% for h-DM and 93.6?±?10.2% for d-DM. Good dose dependency was observed on Cmax and AUC. The stability study of ST in DM was performed for 3 months under four different conditions, ?80, 4, 23, and 50°C. At the end of incubation period, they were, respectively, 100.0?±?0.3%, 97.8?±?0.2%, 98.8?±?0.2%, and 100.7?±?0.1%. These suggest the usefulness of DM as a noninvaisive transdermal delivery system of ST to migraine therapy.     

A systematic study on solid-state synthesis of monticellite (CaMgSiO4) based ceramic powders obtained from boron derivative waste

Solid-state synthesis of monticellite based ceramic powders from boron derivative waste in an eco-friendly route and the investigation of phase transformation mechanisms were studied. The heat-treatment of boron derivative waste, mainly composed of dolomite, calcite and quartz, was systematically carried out at 650?°C and 800?°C for various dwell times between 1?min and 4?h. The heat-treatment temperatures were selected considering TG-DTA curves of waste and ΔG – T diagrams obtained using FactSage Thermochemical Software. XRF, XRD, FTIR, TG-DTA and SEM analysis, particle size measurement and crystallite size determination carried out extensively. The obtained results showed that monticellite based ceramic powder synthesized at 800?°C for 4?h was composed of monticellite, akermanite, diopside, calcium magnesium borate and zeolite. The calcination of dolomite was completed both at 650?°C for 1?h and up to 800?°C, and calcite was decomposed at 800?°C for 30?min. Both diopside and monticellite were firstly detected at 650?°C for 30?min and at 800?°C for 1?min. Also, akermanite was presented at 800?°C for 1?min. The presented method offers the lowest temperature (800?°C) in literature for synthesis of monticellite and akermanite which reduces the energy consumption during heat-treatment.     

Microstructure of In-Situ composites

In this paper, the results of several years of research work by the authors on the microstructure of In-Situ composites are reviewed. Alloy systems investigated are the fibrous Al? Ni and cobalt-base superalloy Co? Cr? C, and the lamellar Al? Cu and Co? W. The effect of solidification variables and off-eutectic compositions on the micro-structure of Al? Ni Co? W and Al? Cu systems was studied. The influence of heat flow direction on the microstructure of Al? Ni was examined. Post solidification isothermal annealing was performed for Al? Cu and Co? Cr? C alloy and thermal cycling regimes were imposed on the Co? Cr? C alloy and the microstructure variations were examined. Computer simulation of directional, solidification to study the heat flow pattern in the metal and mould was also performed. It was found that low growth rates, high temperature gradients, eutectic composition and pure materials favor a planar solidification front and an aligned structure. Increasing the growth rate resulted in finer structures. The thermal stability of In-Situ composites was found to be reasonably good due to the strong interfacial bond between matrix and reinforcement in this class of composites.     

Formulation and Comparative Characterization of Chitosan,Gelatin, and Chitosan–Gelatin-Coated Liposomes of CPT-11–HCl

Liposomes containing phosphatidylcholine and cholesterol (uncoated) and coated by chitosan, gelatin, and combination of chitosan and gelatin were prepared by the modified ethanol injection method. The aim of this work was to formulate and characterize liposomes of camptothecin (CPT)-11–HCl (Irinotecan HCl) containing chitosan, gelatin, and both polymers as coating materials; and also to increase its circulation longevity when compared with the free drug while maintaining the agent in its active lactone form. Size, shape, zeta potential, encapsulation efficiency, stability study, in vitro, and in vivo release study were used for characterization of liposomes. The size of liposomes was in the order of uncoated?<?chitosan coated?<?gelatin coated?<?combination of chitosan and gelatin coated. The zeta potential of liposomes was in the order of combination of chitosan and gelatin coated?>?chitosan coated?>?gelatin coated?>?uncoated. The formulations showed the long-term stability. The encapsulation efficiency of liposomes was in order of combination of chitosan and gelatin coated?>?gelatin coated?>?chitosan coated?>?uncoated. The in vitro and in vivo release of drug was observed in the order of combination chitosan and gelatin coated?>?gelatin coated?>?chitosan coated?>?uncoated.     

Improved dissolution rate and bioavailability of fenofibrate pellets prepared by wet-milled-drug layering

Objective: The objective of this study is to investigate the wet-milled-drug layering process which could significantly improve the dissolution rate and oral bioavailability of fenofibrate pellets. Methods: Fenofibrate was milled with HPMC-E5 to prepare a uniform suspension in the micrometer and nanometer range, and this suspension was then layered on to sugar spheres to form the pellets (F1, F2). Results: The particle size was significantly reduced (from 1000 μm to 1-10 μm and 400?nm) but the fenofibrate in suspension retained its crystallinity from the results of DSC and PXRD investigations. The dissolution rate of F1-F2 and Antara? capsules was 55.47 %, 61.27 % and 58.43 %, respectively, in 0.01?mol/L SDS solution over 60?min. In addition, F1, F2, and Antara? capsules were given orally to 6 beagle dogs to determine the bioavailability. The C(max) of F1, F2 (8.21?±?2.55 and 9.33?±?2.37 μg/mL)and the AUC((0-t)) of F1, F2 (152.46?±?78.89 and 172.17?±?67.58 μg/mL·h)were higher than those of Antara? (6.02?±?3.34 μg/mL and 89.82?±?46.46 μg/mL·h) and, F1, F2 reached their C(max) earlier than Antara? (F1: 2.0?±?1.1?h; F2: 1.8?±?1.2?h; Antara?: 6.0?±?8.9?h). Conclusion: These results show that the wet-milled-drug layering technique is a powerful method to improve the dissolution rate and the bioavailability of fenofibrate.     

Investigation of WC–Co alloy properties based on thermodynamic calculation and Weibull distribution

The influence of alloy composition and sintering temperature on the mechanical properties and reliability of WC–Co cemented carbides was studied theoretically and experimentally. For the first time, through a hybrid approach of thermodynamic calculations and Weibull distribution, the comprehensive performance of ultrafine WC–Co cemented carbides with different C contents and inhibitor type was investigated in detail. The carbon content of WC–10?wt-% Co–0.5?wt-% Cr cemented carbides was carefully controlled within the range of 5.38?5.52?wt-%. The contents of Cr and V are chosen to be in the range of 0–1?wt-%. It is found that WC–10?wt-% Co–0.5?wt-% Cr alloys with 5.46?wt-% C or 5.5?wt-% C show excellent mechanical properties and high reliability. WC–10?wt-% Co alloys with 0.5?wt-% Cr and 0.4?wt-% Cr–0.2?wt-% V demonstrate high mechanical property and reliability. The results of this study can be used to design process parameters during the manufacture of WC–Co cemented carbides.     

激发子诱导植物基因表达研究进展

介绍了基因诱导表达调控的研究方法，并概述了与ABA，乙烯，真菌激发子诱导表达相关的顺式作用元件（G-box,GT-1结合位点，GCC－blox,W-box)，以及与这些顺式作用元件相互作用的转录因子（GBFS，GT－1，EREBPS，WRKY）。同时对植物基因诱导表达调控的分子机制作了综述。     

Radiation synthesis of PVP/alginate hydrogel containing nanosilver as wound dressing

Hydrogels with polyvinyl pyrrolidone (PVP) and alginate were synthesized and silver nanoparticles were incorporated in hydrogel network using gamma radiation. PVP (10?and 15?%) in combination with 0.5?and 1?% alginate was gamma irradiated at different doses of 25?and 40?kGy. Maximum gel percent was obtained with 15?% PVP in combination with 0.5?% alginate. The fluid absorption capacity for the PVP/alginate hydrogels was about 1881–2361?% at 24?h. Moisture vapour transmission rate (MVTR) of hydrogels containing nanosilver at 24?h was 278.44?g/(m²h). The absorption capacity and moisture permeability of the PVP/alginate–nanosilver composite hydrogel dressings show the ability of the hydrogels to prevent fluid accumulation in exudating wound. The hydrogels containing nanosilver demonstrated strong antimicrobial effect and complete inhibition of microbial growth was observed with 70?ppm nanosilver dressings. PVP/alginate hydrogels containing nanosilver with efficient fluid handling capacity and antimicrobial activity was found suitable for use as wound dressing.     

Analysis of hardness of nanocrystalline coatings of aluminum-rich Ti1???x Al x N

Titanium aluminum nitride coatings were fabricated by a d.c. magnetron sputtering system from a Ti?CAl (60/40?wt%) target. Coatings were deposited on steel substrates, at a substrate temperature of 250?°C and a bias voltage of ?80?V. The nitrogen flow was varied from 1·5?C6?sccm and the Ar flow was kept constant at 20?sccm. The morphology and microstructure of the coatings were analysed by X-ray diffraction and scanning electron microscopy. The results of X-ray diffraction showed the presence of two cubic crystalline phases, TiN and AlN, which were confirmed by X-ray photoelectron spectroscopy. The Vicker hardness was obtained by the effective model of indentation. It was observed that the hardness of the coatings decreases from 22·8?C9·5?GPa with an increased nitrogen content from 1·5?C4·5?sccm. Subsequently, the hardness increased to 22·1?GPa by increasing nitrogen to 6?sccm. The behavior of hardness with grain size variation is consistent with the Hall-Peth relationship. The high value in the hardness of the coatings is mainly attributed to small grain sizes and the compressive stress present.     

Preparation method of low-oxygen Ti-6Al-4V alloy by solid state re-deoxidation using calcium

The oxygen concentration in commercial Ti-6Al-4?V alloys was reduced to less than 400?ppm in this study by the method of solid state re-deoxidation, using calcium as a reductant. The concentration of oxygen in the deoxidised Ti-6Al-4?V alloy was 630?ppm at the optimum deoxidation temperature of 1000°C. When the degree of vacuum was increased and re-deoxidation was carried out, the oxygen concentration decreased to 355?ppm. Therefore, it is possible to prepare a Ti-6Al-4?V alloy with an oxygen concentration of less than 400?ppm by using the solid state re-deoxidation method at a high degree of vacuum of 1.5?×?10-6 Torr.