Enhanced generation of reactive oxygen species and photocatalytic activity by Pt-based metallic nanostructures: the composition matters

The modification of semiconductor nanostructures with metallic nanocomponents can promote the separation of electron/hole from photoexited semiconductors by forming heterojunctions, thus exhibit enhanced photocatalytic activities and potential applications. In this study, Pt-based NPs, including Pt, PtCu, and PtCuCo are employed as model co-catalysts to comparatively study their capability to enhance the photocatalytic activity of TiO₂ nanosheets. It was found that each of Pt, PtCu, and PtCuCo can greatly enhance the photocatalytic activity of TiO₂ toward degradation of organic dyes. Using electron spin resonance spectroscopy, we demonstrated that deposition of Pt-based NPs resulted in more production of reactive oxygen species including hydroxyl radicals, superoxide, and singlet oxygen. The enhancing effects of Pt-based NPs on generation of ROS and photocatalytic activity showed same trend: PtCuCo?>?PtCu?>?Pt. The mechanism underlying the enhancement differences in Pt-based NPs may be mainly related to electronic structure change of Pt in alloying with Cu and Co. These results are valuable for designing hybrid nanomaterials with high photocatalytic efficiency for applications in water purification and antibacterial products.     

Intermittent Internal Fixation With a Locking Plate to Preserve Epiphyseal Growth Function During Limb-Salvage Surgery in a Child With Osteosarcoma of the Distal Femur: A Case Report

Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur.The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed.The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient''s height had increased 52 cm, shortening of the affected limb was only 1 cm, and the circumference of the affected limb was 2 cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers.In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and provides good functional recovery.     

基于“证治代谢组学”假说探讨中药（单体/复方）药效物质基础的研究思路与实践＊

中药(单体/复方)药效物质基础研究是中医药现代研究的关键问题之一。然而,目前运用的生化和分子生物学方法很难诠释其多靶点、整体性和动态性的整合调节作用。课题组提出的"证治代谢组学"假说理论指出,不同的证候存在"证相关代谢谱群"和"证相关生物标志物",这可能是中药药效物质基础所在,辨证论治后偏离的代谢网络功能呈现回归趋势。基于"证治代谢组学"假说开展中药(单体/复方)药效物质基础研究,这将为阐释中药(单体/复方)防病治病和养生保健的科学内涵及其对疾病个体的整合调节作用提供新的思路。本文以冠心病为研究载体、气阴虚血瘀证为切入点、活血保心丸为干预措施,就该研究思路的内涵与总体模式、提出的背景与依据、实践的方式与可行性、创新与特色及其研究意义等进行了简要介绍。     

土耳其斯坦东毕吸虫磷酸丙糖异构酶基因的克隆及其序列分析

目的 克隆土耳其斯坦东毕吸虫磷酸丙糖异构酶的全长基因。方法 根据日本血吸虫和曼氏血吸虫磷酸丙糖异构酶基因的保守区设计引物，利用RT—PCR扩增出土耳其斯坦东毕吸虫磷酸丙糖异构酶基闪的大片段，再结合RACE技术分别得到磷酸丙糖异构酶基因的3’端和5’端，将3部分序列拼接后获得磷酸丙糖异构酶基因全长cDNA序列，并提交GenBank。结果 成功克隆了土耳其斯坦东毕吸虫磷酸丙糖异构酶基因全长cDNA序列并提交GenBank，登录号为DQ092331。结论 土耳其斯坦东毕吸虫磷酸丙糖异构酶基因全长cDNA的克隆为进一步表达及其生物学性能的分析提供了理论基础。     

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现将2005年我国小儿血液系统疾病的临床进展简述如下。1白血病白血病仍然是威胁我国儿童生命的严重疾病之一。由于社会、文化、经济及治疗条件的限制,儿童白血病坚持正规治疗者仍属少数。汤静燕等[1]随访上海地区(包括外地到沪治疗者)急性淋巴细胞白血病(ALL)244例,66例在诊断后不同时段放弃治疗(依从失败),总依从失败为29·5%,在经济发达的上海地区尚且如此,对于经济欠发达地区由此可见一斑。因此,作者提出应当针对不同地区制定治疗强度减弱的化疗方案,倘若能获得50%~60%的5年无病生存率也是一个进步。该组患儿入院并治疗满15d者164例,治…     

外科学教学中的审美教育

医学审美教育是医学生全面素质教育不可分割的组成部分,笔者结合长期外科教学实践,阐述了在外科学教学中运用医学美学原理对外科学的美进行开发和挖掘,使医学生在熟练掌握外科学基本理论和基本技能的同时,潜移默化地接受美的教育,美的熏陶,更能激发他们对外科学的热爱和兴趣,达到全面提高医学生整体素质的目的。     

急性一氧化碳中毒后迟发性脑病的临床表现和影像学特点

目的探讨急性一氧化碳中毒后迟发性脑病的临床表现和影像学特点及其诊断价值。方法回顾性对23例急性一氧化碳中毒后迟发性脑病的临床表现和影像学特点进行归纳和分析。结果23例患者中智能障碍23例（100％），言语功能障碍17例（73.9％），另有共济失调精神障碍帕金森综合症及尿失禁等。头部CT和MRI主要表现为皮层下脑白质异常信号及基底节区或苍白球区异常信号，极少累及大脑皮质脑干和小脑。结论急性一氧化碳中毒后迟发性脑病的诊断主要依靠病史和临床症状，MRI比CT更有诊断价值。     

静脉用免疫球蛋白的治疗作用机制及其不良反应

静脉滴注免疫球蛋白用于多种自身免疫性疾病和炎症性疾病的治疗,其作用机制包括对自身抗体的作用,抑制补体结合,阻止膜攻击复合物形成,调节巨噬细胞Fc受体,抑制致病性细胞因子和其他免疫调节分子等。该药不反应反应较少,主要有皮肤过敏反应、无菌性脑膜炎、血浆黏度增加和血栓形成以及肾功能损害等。     

92例重型肝炎并发自发性细菌性腹膜炎的诊断与治疗

目的探讨重型肝炎并发自发性细菌性腹膜炎(SBP)的诊断和抗生素使用。方法回顾性分析2002年7月~2005年6月间收治的92例并发SBP的重型肝炎患者的临床资料。结果92例患者中,发热72例(78.26%),腹胀85例(92.39%),腹痛38例(41.30%),反跳痛35例(38.04%),83例(90.21%)外周血中性粒细胞(PMN)分类≥0.75,40例(45.98%)腹水PMN计数≥250个/mm3,79例(90.80%)腹水PMN比值≥0.50,11例(12.00%)腹水细菌培养阳性,共分离出细菌17株,G-杆菌占52.9%(9/17),其对头孢曲松、头孢哌酮、头孢他啶、左旋氧氟沙星及泰能敏感,对丁胺卡那、氧哌嗪青霉素敏感性较低。临床治疗显示,联合使用头孢他啶和甲硝唑效果较好,并较少出现继发真菌感染。结论重型肝炎并发SBP患者的临床表现不典型,腹水培养阳性率低,外周血和腹水PMN比值是诊断SBP比较可靠的参数。治疗SBP,可首选二联使用头孢他啶与甲硝唑,疗程约10~14日。