pH-Dependent Photophysical Properties of Metallic Phase MoSe2 Quantum Dots

Fluorescence properties of quantum dots (QDs) are critically affected by their redox states, which is important for practical applications. In this study, we investigated the optical properties of MoSe₂-metallic phase quantum-dots (MoSe₂-mQDs) depending on the pH variation, in which the MoSe₂-mQDs were dispersed in water with two sizes (Φ~3 nm and 12 nm). The larger MoSe₂-mQDs exhibited a large red-shift and broadening of photoluminescence (PL) peak with a constant UV absorption spectra as varying the pH, while the smaller ones showed a small red-shift and peak broadening, but discrete absorption bands in the acidic solution. The excitation wavelength-dependent photoluminescence shows that the PL properties of smaller MoSe₂-mQDs are more sensitive to the pH change compared to those of larger ones. From the time-resolved PL spectroscopy, the excitons dominantly decaying with an energy of ~3 eV in pH 2 clearly show the shift of PL peak to the lower energy (~2.6 eV) as the pH increases to 7 and 11 in the smaller MoSe₂-mQDs. On the other hand, in the larger MoSe₂-mQDs, the exciton decay is less sensitive to the redox states compared to those of the smaller ones. This result shows that the pH variation is more critical to the change of photophysical properties than the size effect in MoSe₂-mQDs.     

Effects of Initial Morphology on Growth Kinetics of Cu6Sn5 at SAC305/Cu Interface during Isothermal Aging

Solder/Cu joints are important components responsible for interconnection in microelectronics. Construction of the solder/Cu joints through liquid/solid (L/S) reactions accompanies the formation of the Cu–Sn intermetallic compounds (IMCs) at the joint interface. The Cu₆Sn₅ IMC exhibits remarkable distinctions in thickness and morphology upon increasing the L/S reaction time. Effects of the initial characteristics of thickness and morphology on the growth kinetics of Cu₆Sn₅ during subsequent isothermal aging were investigated. SAC305 solder was reflowed on a Cu electroplated layer at 265 °C for 1 to 60 min to produce the Cu₆Sn₅ IMC with different thickness and morphology at the SAC305/Cu interface. The as-fabricated SAC305/Cu joint samples were aged at 200 °C for 72 to 360 h to investigate the growth kinetics of Cu₆Sn₅. The results show that the initial characteristics of thickness and morphology significantly influenced the growth kinetics of Cu₆Sn₅ during the subsequent solid/solid (S/S) reaction. A prolonged L/S reaction time of 60 min (L/S-60) produced a scallop-type Cu₆Sn₅ IMC with a larger grain size and a thicker thickness, which reduced the quantity of fast diffusion path (grain boundary) and the magnitude of concentration gradient, thus slowing down the growth rate of Cu₆Sn₅. According to the growth kinetics analysis, the growth rate constant of Cu₆Sn₅ could be remarkably reduced to 0.151 µm/h^0.5 for the L/S-60 sample, representing a significant reduction of 70 % compared to that of the L/S-1 sample (0.508 µm/h^0.5 for L/S reaction time of 1 min).     

Effects of In-Process Ultrasonic Vibration on Weld Formation and Grain Size of Wire and Arc Additive Manufactured Parts

Wire and arc additive manufacturing (WAAM) is a competitive technique, which enables the fabrication of medium and large metallic components. However, due to the presence of coarse columnar grains in the additively manufactured parts, the resultant mechanical properties will be reduced, which limits the application of WAAM processes in the engineering fields. Grain refinement and improved mechanical properties can be achieved by introducing ultrasonic vibration. Herein, we applied ultrasonic vibration to the WAAM process and investigated the effects of wire feed speed, welding speed, and ultrasonic amplitude on the weld formation and grain size during ultrasonic vibration. Finally, a regression model between the average grain size and wire feed speed, welding speed, and ultrasonic amplitude was established. The results showed that due to the difference in heat input and cladding amount, wire feed speed, welding speed, and ultrasonic amplitude have a significant influence on the weld width and reinforcement. Excessive ultrasonic amplitude could cause the weld to crack during spreading. The average grain size increased with increasing wire feed speed and decreasing welding speed. With increasing ultrasonic amplitude, the average grain size exhibited a trend of decreasing first and then increasing. This would be helpful to manufacture parts of the required grain size in ultrasonic vibration-assisted WAAM fields.     

烧伤药油治疗中小面积Ⅱ度烧伤43例临床观察

目的：观察烧伤药油治疗中小面积Ⅱ度烧伤的临床疗效。方法：将Ⅱ度烧伤患者103例随机分为对照组57例、治疗组46例。2组均洗必泰喷洒消毒后,去除已破溃的腐皮,对照组涂抹磺胺嘧啶银乳膏,包扎换药,1次/d,治疗组涂抹院内自制药烧伤药油1 mm厚,保持创面润泽,每日涂药4～6次。2组均连续治疗30天后观察创面愈合时间及临床疗效。结果：治愈率治疗组为58.70%,对照组为36.84%,2组比较差异显著（P＜0.05）。总有效率治疗组为95.65%,对照组为80.70%,2组比较差异显著（P＜0.05）;浅Ⅱ度伤创面平均愈合时间治疗组为（9.6±1.97）天,对照组为（12.3±1.49）天,2组比较差异有统计学意义（P＜0.05）;深Ⅱ度伤创面平均愈合时间治疗组为（18.7±1.89）天,对照组为（22.7±1.53）天,2组比较差异有统计学意义（P＜0.05）。结论：烧伤药油治疗中小面积Ⅱ度烧伤临床疗效显著,可加快创面愈合。     

麦角甾苷固体脂质纳米粒处方筛选和理化性质研究

目的 研究不同种类药用辅料成分对麦角甾苷固体脂质纳米粒（SLN）理化性质的影响,为研究SLN的处方筛选提供依据。方法 采用乳化-固化法制备麦角甾苷-SLN,单一变量法考察山嵛酸甘油酯（Compritol ATO 888）、单硬脂酸甘油酯、大豆卵磷脂、Myrj52等辅料对麦角甾苷-SLN粒径、包封率、表征分散度（PDI）等理化性质的影响,采用透射电镜法观察麦角甾苷-SLN的形态,X-射线衍射（XRD）分析其药物晶体结构。结果 随Compritol ATO 888用量增加,麦角甾苷-SLN粒径不断减小,包封率逐渐减小,PDI逐渐增加;随单硬脂酸甘油酯的用量增加,粒径明显增大,包封率略有降低,PDI减小;随卵磷脂用量增加,粒径明显增大,包封率降低,PDI减小;随Myrj52用量明显增加,粒径减小,包封率增加,PDI增大;麦角甾苷-SLN外观圆整,呈球形;麦角甾苷以分子分散状态被包裹在SLN中。结论 不同辅料对麦角甾苷-SLN的理化性质均产生一定影响趋势,为制备SLN的处方筛选研究提供启示与思路。     

Intraoperative blood transfusion in pediatric patients undergoing renal transplant—Effect of renal graft size

In pediatric RT, donor allograft size often exceeds the expected recipient norms, especially in younger recipients. An “oversize” graft might not only present a technical‐ and space‐related challenge, but may possibly lead to increased demands in perioperative volume requirements due to the disparity between donor and recipient in renal blood flow. We evaluated transfusion practices at a single tertiary institution with special consideration of kidney graft size, hypothesizing that oversize graft kidneys might lead to a quantifiable increased need of blood transfusion in smaller recipients. Retrospective analysis of all patients who underwent pediatric RT from January 2004 to June 2014 at a tertiary pediatric centre was performed. Variables analyzed included patient age, weight, pre‐ and postoperative Hb concentration, graft size, EBL, amount of intraoperative blood transfusion, and preoperative use of erythropoietin. Based on graft size in relation to patient's age, a SMR and an OvR were identified. A subcohort of age‐matched pairs was used to allow for comparison between groups. We calculated the expected procedure‐ and transfusion‐induced changes in Hb and compared these changes to the observed difference in pre‐ vs postoperative Hb to assess the influence of graft size on transfusion requirements. RT was performed in 188 pediatric recipients during the study period. In the matched cohort, percentage of transfused patients during transplantation in the OvR group was more than double compared with SMR (89% vs 39%, P < .001); similarly, the median number of transfused PRBC units in OvR was 1, while the median of SMR did not receive transfusion (P < .001). The difference between expected (calculated) and observed change in Hb was significantly higher in OvR with a median of 1.9 g/dL compared with SMR with a median of 1.0 g/dL (P = .026). Correspondingly, the calculated median volume taken up by a regular size kidney was significantly higher with 213 mL compared with 313 mL (P = .031) taken up by an oversize graft kidney. Median estimated intraoperative blood loss was significantly higher in OvR than in SMR (6.9 mL/kg, vs 5.3 mL/kg, respectively; P = .04). Median postoperative Hb was similar among groups (10.4 g/dL vs 10.6 g/dL for SMR vs OvR, respectively). Transplantation of an oversized kidney in pediatric RT recipients is associated with a quantifiable higher need for blood transfusion. This may be caused by a higher intraoperative EBL and/or greater blood volume sequestered by the larger renal allograft and requires further evaluation.     

芪参益气浸膏动员内皮祖细胞促进大鼠梗死心肌血管新生

目的:观察芪参益气浸膏对急性心肌梗死大鼠内皮祖细胞(EPCs)动员,促进梗死心肌新生血管形成,减小梗死面积的效果。方法:①成年Wistar大鼠左前降支结扎造模,随机分为空白组(A)、假手术组(B)、AMI组(C);芪参益气浸膏治疗AMI组(D)。②流式细胞技术检测不同时段大鼠外周静脉血EPC动态变化。③4周末处死大鼠,心肌切片Masson染色,左室心肌正中线孤长方法计算梗死面积。④CD_(31)单克隆抗体免疫组化法标记心肌新生血管内皮细胞并计算各组梗死、梗死周边及非梗死区新生血管数。结果:①造模后第7天,D组外周血EPCs数明显高于A、B、C组(P0.05),C组高于A、B组(P0.05),A、B组间EPCs变化无统计学意义(P0.05);14天D组外周血EPCs数明显高于A、B、C组(P0.05),A、B、C组间依次增高,有统计学意义(P0.05);组内比较,仅D组14天时EPCs仍维持较高水平。②D组梗死及梗死周边区新生血管计数明显多于C组(分别P0.05)。③D组梗死面积小于C组(P0.05)。结论:①芪参益气浸膏能动员急性心肌梗死大鼠内皮祖细胞进入外周血循环,使其数量增加并促进梗死周边区血管新生。②梗死后大鼠应用芪参益气浸膏可以限制梗死面积。     

超临界CO2抗溶剂法制备黄芩素微粒的工艺研究

目的 以微粒的体积平均粒径为评价指标,优化黄芩素微粒的制备工艺.方法 采用超临界CO2抗溶剂法制备黄芩素微粒,在单因素试验的基础上设计正交试验优选黄芩素微粒的制备工艺,并对优选的工艺组合进行了粒度分布、扫描电镜(SEM)分析、红外吸收光谱法(IR)及差示扫描量热法(DSC)的表征.结果 正交试验得到的优选工艺条件:溶液体积流量0.75 mL/min,结晶压力8 MPa,结晶温度48℃,黄芩素质量浓度4 mg/mL;在此工艺条件下制备得到的黄芩素微粒的大小明显小于黄芩素原料,扫描电镜显示制备出的黄芩素微粒为不规则形状;IR和DSC显示黄芩素微粒的化学结构没有发生变化,热力学性质发生了变化,并且经处理过的黄芩素的纯度变高.结论 超临界CO2抗溶剂法制备黄芩素微粒可行,为制备超细微粒提供参考依据.     

散结消瘿汤对Graves病患者甲状腺大小及促甲状腺素受体抗体的影响

目的 :评价Graves病(GD)患者应用散结消瘿汤对临床疗效、甲状腺大小及促甲状腺素受体抗体(TRAb)的影响。方法:选取90例GD患者作为研究对象,按照随机平行分组法随机分为治疗组与对照组各45例,两组患者均给予常规西医治疗方案,治疗组在此基础上联用散结消瘿汤治疗,疗程均为12周,比较两组患者临床疗效、甲状腺大小及TRAb变化。结果:治疗组与对照组临床愈显率分别为86.7%、64.5%,两组差异有统计学意义(χ2=13.206,P=0.027);治疗后两组患者FT3、FT4及甲状腺大小均较治疗前差异有统计学意义(P0.05),且同期组间比较差异有统计学意义(P0.05);治疗组TRAb与治疗前相比差异有统计学意义(P0.05),而对照组TRAb治疗前后相比差异无统计学意义(P0.05)。结论:对GD患者加用散结消瘿汤有利于改善临床症状、体征,缩小甲状腺肿,其可能与降低TRAb水平有关。     

基于肿瘤浸润深度及大小的TTS 评分系统对可切除胃癌患者预后判断的价值

目的:探讨基于肿瘤浸润深度及大小的TTS评分系统对可切除胃癌患者预后判断的价值。方法:选择行根治性切除的234例胃癌患者为研究对象。根据肿瘤浸润深度（T分期）和肿瘤大小构建TTS评分系统,分为TTS 0级、1级、2级,代表肿瘤侵袭性逐渐升高。通过Cox多因素模型分析TTS评分系统作为预后判断工具的可行性。结果:T1-T4期患者肿瘤的平均大小分别为(3.3±2.7)cm、(4.1±3.1)cm、(6.6±3.1)cm、(9.4±4.9)cm。单因素分析显示,肿瘤浸润深度与肿瘤大小、淋巴结转移、TNM分期、淋巴浸润和血管浸润显著相关(P＜0.01)。ROC曲线显示,45 mm为肿瘤大小的最佳界值,可有效区分患者是否存在淋巴结转移,曲线下面积(area under curve,AUC)为0.762。综合肿瘤大小的临界值和肿瘤浸润深度,构建TTS评分系统,TTS 0级、TTS 1级和TTS 2级的患者5年生存率分别为95.6%、83.3%和70.2%,两两比较后发现,不同TTS状态患者的生存率之间均存在显著差异(P＜0.01)。Cox多因素分析发现,TTS评分是影响患者预后的独立性危险因素（P＜0.05）。结论:本研究根据肿瘤浸润深度和大小构建了TTS评分系统,并证明了TTS评分与胃癌患者的预后密切相关。