多波长萤光分光光度法(二)——萤光黄、罗丹明6G和罗丹明B三组分混合物的测定

本文叙述了应用多波长萤光分光光度法测定人工样品中的萤光黄、罗丹明6G和罗丹明B_。于波长502nm直接测量萤光黄的萤光强度,罗丹明6G和罗丹明B均不干扰;罗丹明6G的测定波长λ_1为555nm,参比波长λ_2和λ_3为502nm和660nm,罗丹明B的测定波长λ_1选用585nm,参比波长λ_2、λ_4和λ_3相应为538nm、508nm和494nm,方法的相对误差一般小于6%。作者于前文叙述了多波长萤光分光光度法的原理,为了验证该原理的可靠性,特对萤光黄、罗丹明6G和罗丹明B人工混合样品进行实测。结果表明,方法原理可靠,实验操作和数据处理简便快速,三次测定平均偏差<3%

AFM微探针在FIB制备透射电镜样品中的应用

制备目标材料的高质量透射电镜样品对透射电镜测试表征和结果分析具有决定性作用。聚焦离子束技术由于其微观定位选区制样的优势在透射电镜样品制备上已有一定应用。但对于一些特殊的样品,由于窗帘效应的影响,普通传统的聚焦离子束制样减薄方法存在远端薄区极易弯曲断裂和薄区厚度不均匀的问题。本文介绍了一种以原子力显微镜的微探针作为载体,在FIB制备透射电镜样品的过程中,将样品进行旋转的操作方法。该方法操作简单,实用性强,通过该方法可改变离子束在样品上的入射方向,从而消除窗帘效应的影响,获得厚度均匀的样品薄区

基于对称双阴极结构固体氧化物燃料电池的快速热稳定性

研究了基于对称双阴极结构电池堆单元和电池短堆从室温到运行温度的多次快速升降温的热稳定性性能。结果显示:由于新结构电池可进行阴极侧电子收集的2次施压操作,且快速升降温后电池堆单元和电池短堆性能维持稳定并还略有上升。因此,无论是电池堆单元还是电池短堆,该结构的电池具有良好的热稳定性与可拆卸的电子收集功能。这种可承受快速升降温和可拆卸电子收集与2次施压的特性为对称双阴极结构电池的快速启动、重复再利用打下了基础,是大面积固体氧化物燃料电池的新型特性,在某些特殊领域具有较强的应用潜质

溶剂萃取-气相色谱／质谱法分析烟草中的主要甾醇

烟草中的甾醇类物质主要有胆甾醇、菜油甾醇、豆甾醇和β-谷甾醇等，这些甾醇的结构中都含有羟基（结构式见图1），热解时其母体的多环结构可形成稠环芳烃，因此烟草中的甾醇是一种潜在的影响人体健康的物质，故对甾醇种类和含量进行分析对卷烟的配方研究具有参考价值

Aripiprazole versus other atypical antipsychotics for schizophrenia

BACKGROUND: In most western industrialised countries, second generation (atypical) antipsychotics are recommended as first line drug treatments for people with schizophrenia. In this review we specifically examine how the efficacy and tolerability of one such agent - aripiprazole - differs from that of other comparable second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (November 2011), inspected references of all identified studies for further trials, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised clinical trials (RCTs) comparing aripiprazole (oral) with oral and parenteral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine for people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. Where possible, we calculated illustrative comparative risks for primary outcomes. For continuous data, we calculated mean differences (MD), again based on a random-effects model. We assessed risk of bias for each included study. MAIN RESULTS: We included 12 trials involving 6389 patients. Aripiprazole was compared to olanzapine, risperidone and ziprasidone. All trials were sponsored by an interested drug manufacturer. The overall number of participants leaving studies early was 30% to 40%, limiting validity (no differences between groups).When compared with olanzapine no differences were apparent for global state (no clinically important change: n = 703, 1 RCT, RR short-term 1.00 95% CI 0.81 to 1.22; n = 317, 1 RCT, RR medium-term 1.08 95% CI 0.95 to 1.22) but mental state tended to favour olanzapine (n = 1360, 3 RCTs, MD total Positive and Negative Syndrome Scale (PANSS) 4.68 95% CI 2.21 to 7.16). There was no significant difference in extrapyramidal symptoms (n = 529, 2 RCTs, RR 0.99 95% CI 0.62 to 1.59) but fewer in the aripiprazole group had increased cholesterol levels (n = 223, 1 RCT, RR 0.32 95% CI 0.19 to 0.54) or weight gain of 7% or more of total body weight (n = 1095, 3 RCTs, RR 0.39 95% CI 0.28 to 0.54).When compared with risperidone, aripiprazole showed no advantage in terms of global state (n = 384, 2 RCTs, RR no important improvement 1.14 95% CI 0.81 to 1.60) or mental state (n = 372, 2 RCTs, MD total PANSS 1.50 95% CI -2.96 to 5.96).One study compared aripiprazole with ziprasidone (n = 247) and both the groups reported similar change in the global state (n = 247, 1 RCT, MD average change in Clinical Global Impression-Severity (CGI-S) score -0.03 95% CI -0.28 to 0.22) and mental state (n = 247, 1 RCT, MD change PANSS -3.00 95% CI -7.29 to 1.29).When compared with any one of several new generation antipsychotic drugs the aripiprazole group showed improvement in global state in energy (n = 523, 1 RCT, RR 0.69 95% CI 0.56 to 0.84), mood (n = 523, 1 RCT, RR 0.77 95% CI 0.65 to 0.92), negative symptoms (n = 523, 1 RCT, RR 0.82 95% CI 0.68 to 0.99), somnolence (n = 523, 1 RCT, RR 0.80 95% CI 0.69 to 0.93) and weight gain (n = 523, 1 RCT, RR 0.84 95% CI 0.76 to 0.94). Significantly more people given aripiprazole reported symptoms of nausea (n = 2881, 3 RCTs, RR 3.13 95% CI 2.12 to 4.61) but weight gain (7% or more of total body weight) was less common in people allocated aripiprazole (n = 330, 1 RCT, RR 0.35 95% CI 0.19 to 0.64). Aripiprazole may have value in aggression but data are limited. This will be the focus of another review. AUTHORS' CONCLUSIONS: Information on all comparisons are of limited quality, are incomplete and problematic to apply clinically. Aripiprazole is an antipsychotic drug with a variant but not absent adverse effect profile. Long-term data are sparse and there is considerable scope for another update of this review as new data emerges from the many Chinese studies as well as from ongoing larger, independent pragmatic trials

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies