氧化石墨烯和氧化石墨烯/银纳米粒子SERS基底制备及初步评价

目的 利用表面增强拉曼光谱散射(surface-enhanced Raman scattering,SERS)能提供独特的分子振动信息的特点制备具有SERS性能的纳米材料,并以对巯基苯胺(PATP)为标记分子对其SERS性能进行评价.方法 通过微波法制备粒径均匀、性能稳定的银纳米粒子(AgNP),利用自组装方式使氧化石墨烯(GO)与AgNP经3-巯基丙基三甲氧基硅烷(MPTMS)耦合形成复合材料,以毛细管作为载体,结合PATP标记分子评价基底的性能.结果GO/AgNP复合基底的拉曼强度高于GO,检测PATP分子的灵敏度可达10-9mol/L.结论 制备的GO/AgNP复合材料作为SERS基底可增强SERS效应,是一种有效的SERS活性基底.     

硫醇修饰的磁性银花纳米粒子SERS基底在氯霉素检测中的应用

目的：制备一种新型的硫醇修饰的磁性银花纳米粒子SERS基底对氯霉素（ CAP）进行拉曼检测,确定SERS基底的增强效果。方法选择烷基硫醇作为基底的表面修饰剂,自组装到磁性银花纳米粒子的银壳表面,通过疏水作用,将CAP分子富集到基底表面,从而实现检测CAP分子拉曼信号的增强。结果3种不同硫醇修饰的基底对CAP的增强顺序是正己硫醇＞十二硫醇＞十八硫醇。利用Fe3 O4＠SiO2-Ag-C6 SERS基底对浓度范围10－3～10－10 mol／L的CAP溶液和10－3～10－9 mol／L的牛奶中CAP进行拉曼检测,检测限分别为0．1 nmol／L（32 ppt）和1 nmol／L（323 ppt）。结论硫醇修饰的磁性银花纳米粒子是一种高活性的SERS基底,可用于低浓度物质的检测分析。     

一种新型的表面增强拉曼散射基底的制备及其在大肠杆菌BL21检测中的应用

目的：研制一种新型的拉曼增强液态基底,采用免标记表面增强拉曼散射（ surface-enhanced Raman scat-tering,SERS ）技术快速检测大肠杆菌。方法采用改进后的Stober方法制备360 nm二氧化硅纳米球（ SiO2）,在其表面结合不同粒径Au＠Ag,制备纳米复合物（ SiO2-Au＠Ag）。通过透射电镜（ TEM）、紫外可见（ UV-Vis）分光光度仪对所制备的纳米结构进行分析表征。以对巯基苯胺（ PATP）为待检分子,筛选出SERS效果最佳的SiO2-Au＠Ag。以此纳米复合物检测不同浓度PATP,并通过简单混合培养的方法检测大肠杆菌。结果透射电镜拍摄图片显示,随着Au＠Ag 粒径增大,结合到SiO2表面的Au＠Ag 聚集度也增加。紫外光谱显示,随着Au＠Ag 粒径增大, Au＠Ag和SiO2-Au＠Ag最大吸收峰红移。通过实验,SiO2-100 nm Au＠Ag检测PATP的灵敏度为10-10 mol／L,最低可检测的大肠杆菌的浓度为105 CFU／ml。结论在该实验范围内,SiO2-Au＠Ag的SERS效应随着SiO2表面结合的Au＠Ag粒径增大而增大。 SiO2-100 nm Au＠Ag具有最强的SERS效应。     

基于表面增强拉曼散射的血清指纹谱检测方法研究

目的：对基于表面增强拉曼光谱检测血清指纹谱的试验条件进行优化。方法以正常人血清为例,银胶溶液为活性基底,分别检测不同血清用量（2．5～500μl）、不同孵育时间（10～30 min）、不同孵育温度（4℃、室温、37℃）及不同血清处理方法（萃取、去蛋白）的增强拉曼信号。结果及结论血清用量不宜超过50μl,与增强基底材料的比例1∶1到5∶1均适宜;孵育时间在10～30 min均可;孵育温度为4℃、室温、37℃均可;血清直接与增强基底混合信号效果极强,进行萃取和去蛋白处理后,拉曼信号会减弱。     

基于表面增强拉曼光谱的肝病血清检测技术研究

目的：通过比较正常人与慢性乙肝、肝硬变和肝癌患者血清之间的拉曼光谱差异,探索基于表面增强拉曼散射（ SERS）的血清诊断新方法。方法首先制备纳米银溶胶作为活性基底,分别测量30例正常人和48例慢性乙肝、48例肝硬变、46例肝癌患者血清的增强拉曼信号,并进行正交偏最小二乘法判别分析（ OPLS－DA ）。结果正常人与3组肝病患者血清在位移625、725、806、947、1018、1219、1131、1329、1440、1580、1660 cm－1处均有拉曼峰,且峰强弱存在差异;正常人血清在位移1096和1395 cm－1处有强峰,肝病患者血清在位移887 cm－1有强峰。 ROC曲线下面积（AUC）分别为0．981、0．966、0．984。结论初步研究表明血清SERS图谱可作为肝病早期诊断的一种辅助手段。     

表面增强拉曼光谱在人类血清中的应用

表面增强拉曼光谱（ surface－enhanced Raman spectroscopy, SERS）近几年来在物理、化学乃至生物医学方面应用广泛。由于其具有较高的灵敏度、特异性,可用来检测人体血清成分的改变。血清中的各种生物分子包括蛋白质、脂类、核酸等都有各自的特征拉曼光谱,因此不同的拉曼位移、谱带强度及宽度,在分子水平上反映了人体血清中不同的细胞代谢异常。该文对SERS的研究概况以及在多种疾病血清检测中的最新研究进展进行了总结和进一步展望。     

聚乳酸羟基乙酸载全氟溴辛烷-四氧化三铁包金纳米粒子双模态成像与光热治疗的体外研究

目的制备具有表面金壳以聚乳酸羟基乙酸(PLGA)为载体包载全氟溴辛烷(PFOB)和四氧化三铁(SPIOs)的纳米粒子,用于探究其体外超声显像和磁共振成像能力和光热杀伤肿瘤细胞效果。方法采用单乳化水包油(O/W)溶剂挥发法制备PFOB-SPIOs@PLGA纳米粒子,金种子生长法形成纳米粒子表面金壳制备;对其进行表征;通过CCK-8法评估纳米粒子的细胞毒性情况;采用超声和磁共振成像仪器观察纳米粒子的体外成像效果;近红外激光照射纳米粒子溶液观测升温效果;AM单染在激光共聚焦下观察光热杀伤肿瘤细胞效果。结果成功制备了PFOB-SPIOs@PLGA@Au纳米粒子,纳米粒子平均粒径(347±65.8)nm,粒径均一,分散性好;磁共振测得r2值为(465.23±30.39)mM-1s-1,具有体外磁共振T2成像效果;具有体外超声成像效果;近红外激光照射纳米粒子溶液10min最高温度可达45.2℃;CCK-8法检测纳米粒子对各组细胞存活率无明显影响。结论成功制备了粒径均一的PFOB-SPIOs@PLGA@Au纳米粒子,该纳米粒子具有较好的超声和磁共振T2体外成像效果和体外升温效果,且无明显细胞毒性。     

二维化学位移成像检测帕金森病基底神经节代谢物浓度的应用

目的利用二维化学位移成像（2D CSI）检测帕金森病（PD）的基底神经节代谢物浓度。探讨PD的基底神经节代谢物浓度是否变化。评估2D CSI技术检测PD的价值。资料与方法符合临床诊断标准的PD患者26例。从健康志愿者中抽取与PD组年龄、性别相匹配的26名健康者作为正常对照组。采用2D CSI技术检测所有人组对象的双侧豆状核、尾状核的代谢物浓度，包括氮-乙酰天门冬氨酸／肌酸复合物（NAA／Cr），氮-乙酰天门冬氨酸／N碱复合物（NAA／Cho）以及Cho／Cr比值。比较PD组和正常对照组的基底神经节相对应核团的代谢物浓度之间的差异。结果PD组双侧豆状核的NAA／Cho和右尾状核的NAA／Cr、左侧尾状核的Cho／Cr比值明显低于正常对照组（P＜0．05）。左侧豆状核Cho／Cr比值明显高于正常对照组（P＜0．05）。结论PD患者的基底神经节代谢物浓度与正常人有差异。2D CSI作为一种可用于检测基底神经节代谢物浓度的无创伤性的方法，将成为检测正常脑的生理性和病变脑的病理性代谢物浓度的变化，尤其是神经元变性性疾病的一种重要手段。     

模拟失重引起的大鼠基底动脉收缩反应性增强

目的为了阐明模拟失重是否引起头部的动脉血管,如基底动脉的收缩反应性增强。方法 中悬吊大鼠模型模拟失重影响。利用离体基底动脉血管环制备测定其对几种血管收缩剂反应性的变化。结果 悬吊４ｗｋ组大鼠的基底动脉血管环对ＫＣｌ「（１０－１００）ｍｍｏｌｌ」、精氨酸加压素「（１０＾－１５－－１０＾－７）ｍｏｌ／Ｌ或５－羟色胺「（１０＾－１２－－１０＾－４）ｍｏｌ／Ｌ」的等长收缩反应较同步对照组均显著升高。两组大     

基于SERS标记免疫检测的研究进展

随着表面增强拉曼光谱（SERS）技术的发展,SERS 与标记免疫技术的结合已成为一种新的医学研究技术。该文从 SERS 标记免疫检测技术的原理、研究进展、存在问题等方面叙述了 SERS 标记免疫检测及其最新发展。归纳了目前提高 SERS 标记免疫检测灵敏度的研究技术及消除 SERS 免疫标记研究中非特异性吸附的方法。对 SERS 标记免疫技术未来的研究方向与发展前景进行了展望。     

甲型流感病毒两种快速检测方法的诊断效能评价

目的评价甲型流感病毒两种快速检测方法的临床诊断效能。方法分别采用化学显色法和荧光法检测流感样病例咽拭子标本377例,同时采用实时荧光定量PCR进行验证,以评价两种方法的临床诊断效能。结果化学显色法与荧光法检测的灵敏度分别为79.08%和90.2%,特异性分别为91.96%和95.09%,两种方法对甲型流感病毒的检出率相仿,其差异没有统计学意义（χ2=1.25,P〉0.05）,总符合率为78.78%。结论与PCR方法比较,两种方法均具有较好的临床应用价值,其中荧光法灵敏度更高,更适于临床快速诊断;化学显色法操作简便,不需特殊仪器,适用于较大样本量的筛查和现场检测。     

Effects of fasted vs fed‐state exercise on performance and post‐exercise metabolism: A systematic review and meta‐analysis

The effects of nutrition on exercise metabolism and performance remain an important topic among sports scientists, clinical, and athletic populations. Recently, fasted exercise has garnered interest as a beneficial stimulus which induces superior metabolic adaptations to fed exercise in key peripheral tissues. Conversely, pre‐exercise feeding augments exercise performance compared with fasting conditions. Given these seemingly divergent effects on performance and metabolism, an appraisal of the literature is warranted. This review determined the effects of fasting vs pre‐exercise feeding on continuous aerobic and anaerobic or intermittent exercise performance, and post‐exercise metabolic adaptations. A search was performed using the MEDLINE and PubMed search engines. The literature search identified 46 studies meeting the relevant inclusion criteria. The Delphi list was used to assess study quality. A meta‐analysis and meta‐regression were performed where appropriate. Findings indicated that pre‐exercise feeding enhanced prolonged (P  = .012), but not shorter duration aerobic exercise performance (P  = .687). Fasted exercise increased post‐exercise circulating FFAs (P  = .023) compared to fed exercise. It is evidenced that pre‐exercise feeding blunted signaling in skeletal muscle and adipose tissue implicated in regulating components of metabolism, including mitochondrial adaptation and substrate utilization. This review's findings support the hypothesis that the fasted and fed conditions can divergently influence exercise metabolism and performance. Pre‐exercise feeding bolsters prolonged aerobic performance, while seminal evidence highlights potential beneficial metabolic adaptations that fasted exercise may induce in peripheral tissues. However, further research is required to fully elucidate the acute and chronic physiological adaptations to fasted vs fed exercise.     

In vivo determination of intra-myocellular lipids in human muscle by means of localized 1H-MR-spectroscopy

Intra-myocellular lipids (IMCL) are stored in droplets in the cytoplasm of muscle cells and are an energy storage form readily accessed during long-term exercise. ¹H-MR spectroscopy methods are presented for noninvasive determination of IMCL in human muscle. This is based on (a) the separation of two resonances in the lipid-CH₂-region, with the one assigned to IMCL being independent of muscle orientation relative to the magnetic field and (b) the fact that IMCL resonances scale along with signal amplitudes of metabolites in the muscle cell (e.g., creatine) when voxel size is increased, while lipid signals of bulk fat show a disproportionate growth. Inter-individual and intra-individual reproducibility studies indicate that the error of the method is about 6% and that IMCL levels differ significantly between identical muscles in different subjects, as well as intra-individually when measured at 1 week intervals. IMCL determinations in a single subject before and after strenuous exercise indicate that lipid stores recover with a t_1/2 of about 1 day.     

普通大学生骑车运动中机体能量消耗和底物代谢的性别差异研究

目的:研究骑车运动过程中机体能量消耗和底物代谢特征的性别差异。方法:8名普通男大学生和10名普通女大学生分别以45、55、65、75%VO2max强度进行骑车运动,采用气体代谢法测定机体的能量代谢状况。结果:(1)在45、55、65、75%VO2max 4个强度,男生总能量消耗水平均高于女生。在65%VO2max强度,女生脂肪参与供能的比例为26.49%,高于男生的18.75%(P<0.05);在75%VO2max强度,女生脂肪参与供能的比例为16.46%,高于男生的10.24%(P<0.05)。在相同运动强度(45、55、65、75%VO2max),男生和女生每公斤体重脂肪的氧化量和供能量无显著差异。(2)男、女生以55%VO2max强度骑车脂肪的氧化量和供能量均高于45、65、75%VO2max三个强度。在55%VO2max强度,男生骑车时机体脂肪的氧化量和供能量分别为4.64mg/min/kg和41.75cal/min/kg,女生分别为4.26mg/min/kg和38.38cal/min/kg。结论:(1)在相同运动强度(%VO2max)下,女生脂肪供能比例高于男生;总能量消耗、糖供能比例和糖氧化量均低于男生;每公斤体重脂肪氧化量和供能量无性别差异。(2)促使单位时间内脂肪最大氧化量的骑车强度(%VO2max)无性别差异。     

辣根过氧化物酶(HRP)底物的研究进展

辣根过氧化物酶(HRP)在酶免疫分析中得到广泛应用.本文综述了三类主要的HRP底物:色原底物、荧光底物和化学发光底物的研究进展,介绍了相应的各种检测方法的优缺点和实际应用,对其他HRP底物的研究前沿也进行了探讨,指出一种包含巯基和酚基的纳米金作为新型的HRP底物,具有灵敏度高、检测成本低、信号值恒定等一系列突出优点,在免疫组化、基因芯片等领域展现出广阔的应用前景.     

Dynamic 13C NMR analysis of pyruvate and lactate oxidation in the in vivo canine myocardium: Evidence of reduced utilization with increased work

In this work, substrate selection was monitored in the left ventricle of the canine myocardium by following pyruvate and lactate oxidation under in vivo conditions at basal and elevated workloads. These studies were conducted in the open chest model using dynamic ¹³C NMR techniques in the presence and absence of dichloroacetic acid (DCA), a well-known activator of pyruvate dehydrogenase (PDH). Following the infusion of (3-¹³C) pyruvate or (3-¹³C) lactate into the left anterior descending artery, highly variable ¹³C enrichments of glutamate, alanine, aspartate, and citrate were noted under low (RPP <14,500 mmHg/min), intermediate (RPP = 15,000–25,000 mmHg/min), and high (RPP > 25,500 mmHg/min) rate pressure products (RPP). At low workloads, the myocardium typically oxidized the infused (3-¹³C) pyruvate or (3-¹³C) lactate and incorporated the labeled carbon into the glutamate pool as expected. However, in a few notable instances (n = 3), ¹³C-enriched pyruvate and lactate were unable to label the glutamate pool under in vivo conditions even at the lowest RPPs, indicating a lack of selection for these substrates by the tricarboxylic acid (TCA) cycle. Nonetheless, the levels of glutamate C4 enrichment observed at low workloads could usually be enhanced by infusion of DCA. Importantly, ¹³C NMR extract analysis revealed that (3-¹³C) pyruvate or (3-¹³C) lactate labeling of the glutamate pool was reduced (<20%) at high workloads in spite of increased DCA concentrations.     

能量底物环境对~(18)F-FDG显像的影响

18 F-氟代脱氧葡萄糖 (1 8F- FDG)显像时的体内能量底物环境 (血浆葡萄糖、游离脂肪酸等的水平 )显著影响肿瘤、心肌及脑等组织对 1 8F- FDG的摄取 ,从而影响影像质量及临床对影像的分析判断。因此 ,根据不同的检查目的 ,合理控制 1 8F- FDG显像时的能量底物环境 ,是提高影像质量及实现正确影像分析的基础。     

棉籽壳菌糠饲喂卡拉库尔羊效果研究

分析了棉籽壳菌糠饲喂卡拉库尔羊的效果。结果表明 ,用菌糠取代 6 0 %的棉籽壳与取代 4 5 %的棉籽壳和全部用棉籽壳 ,卡拉库尔羊平均日增重差异不显著 (P >0 .0 5 ) ,而饲料成本比对照组降低 0 .11元 /kg ,经济效益显著     

13C呼气试验的方法学及在胃肠病临床的应用

13C呼气试验因其具有安全和非侵害性等特点已被广泛应用于营养学、药物代谢和胃肠疾病诊断等研究。应用不同的标记物,除进行幽门螺杆菌感染检测外,还可在胃排空、胰腺外分泌功能、小肠细菌衍生、肝脏功能等检测中发挥重要作用。     

Changes in peak fat oxidation in response to different doses of endurance training

The effect of different doses of endurance training on the capacity to oxidize fat during exercise in sedentary, overweight men and assessment of variables associated with changes in peak fat oxidation (PFO) were evaluated. Young, sedentary, overweight men were randomized to either the high‐dose (HIGH, 600 kcal/day, n = 17) or moderate‐dose (MOD, 300 kcal/day, n = 18) endurance training groups or controls (CON, n = 15). PFO and peak oxygen uptake (VO₂ peak) were measured using indirect calorimetry, body composition using dual‐energy x‐ray absorptiometry, and protein levels of mitochondrial enzymes determined by Western blotting. PFO increased in both MOD [1.2 mg/kg fat‐free mass (FFM)/min, 95% confidence interval (CI): 0.08:2.3, P = 0.03] and HIGH (1.8 mg/kg FFM/min, CI: 0.6:2.9, P < 0.001) compared with CON. Skeletal muscle expression of citrate synthase, β‐hydroxyacyl‐CoA dehydrogenase, and mitochondrial oxphos complexes II‐V increased similarly in MOD and HIGH. Stepwise multiple linear regression analysis with backward elimination of individual variables correlated with changes in PFO revealed increases in cycling efficiency, FFM, and VO₂ peak as the remaining associated variables. In conclusion, PFO during exercise increased with both moderate‐ and high‐dose endurance training. Increases in PFO were mainly predicted by changes in VO₂ peak, FFM, and cycling efficiency, and less with skeletal muscle mitochondrial enzymes.