复方次氯酸钠消毒剂对室内空气消毒效果观察

目的观察复方次氯酸钠消毒剂对室内空气消毒效果。方法采用气溶胶喷雾法和空气采样器方法进行了现场消毒效果评价并与紫外线照射消毒法作平行比较。结果用含有效氯500mg/L复方次氯酸钠消毒液按照20ml/m3用量进行气溶胶喷雾消毒,密闭作用10min,对室内空气中自然菌杀灭率为99.34%。在相同条件下用30W功率的紫外线灯照射30min,对室内空气中自然菌杀灭率为85.58%。结论复方次氯酸钠消毒剂用气溶胶喷雾法,在较低浓度下对室内空气中自然菌杀灭效果可达到消毒合格要求,比紫外线灯消毒效果好。     

Dynamical evidence for causality between galactic cosmic rays and interannual variation in global temperature

As early as 1959, it was hypothesized that an indirect link between solar activity and climate could be mediated by mechanisms controlling the flux of galactic cosmic rays (CR) [Ney ER (1959) Nature 183:451–452]. Although the connection between CR and climate remains controversial, a significant body of laboratory evidence has emerged at the European Organization for Nuclear Research [Duplissy J, et al. (2010) Atmos Chem Phys 10:1635–1647; Kirkby J, et al. (2011) Nature 476(7361):429–433] and elsewhere [Svensmark H, Pedersen JOP, Marsh ND, Enghoff MB, Uggerhøj UI (2007) Proc R Soc A 463:385–396; Enghoff MB, Pedersen JOP, Uggerhoj UI, Paling SM, Svensmark H (2011) Geophys Res Lett 38:{"type":"entrez-nucleotide","attrs":{"text":"L09805","term_id":"177519"}}L09805], demonstrating the theoretical mechanism of this link. In this article, we present an analysis based on convergent cross mapping, which uses observational time series data to directly examine the causal link between CR and year-to-year changes in global temperature. Despite a gross correlation, we find no measurable evidence of a causal effect linking CR to the overall 20th-century warming trend. However, on short interannual timescales, we find a significant, although modest, causal effect between CR and short-term, year-to-year variability in global temperature that is consistent with the presence of nonlinearities internal to the system. Thus, although CR do not contribute measurably to the 20th-century global warming trend, they do appear as a nontraditional forcing in the climate system on short interannual timescales.The basic principles behind a possible connection between galactic cosmic rays (CR) and global temperature (GT) are as follows: It has been known since the invention of the cloud chamber in 1911 by Charles Thomson Rees Wilson that ionizing radiation leads to atmospheric cloud nucleation. Although the prime source of ionizing radiation in the global troposphere is CR, the flux of CR reaching the troposphere depends on the solar wind. The solar wind is a stream of ionized gases that blows outward from the Sun, and its intensity varies strongly with the level of surface activity on the Sun. The Earth''s magnetic field shields the planet from much of the solar wind, deflecting that wind like water around the bow of a ship. When solar activity is great, the solar wind is strong, swiping away CR arriving at the top of the atmosphere. These CR are hypothesized to affect cloud formation and cloudiness, and therefore GT. The net radiative effect of cloudiness depends on the difference between incoming solar radiation and outgoing long-wave radiation. Increased cloudiness in the upper troposphere reduces outgoing long-wave radiation, thereby resulting in warming of the planet. Increased cloudiness in the lower troposphere causes less incoming radiation, and therefore cooling of the planet. Data suggest (6) that the amount of CR is positively correlated with the amount of low-level clouds but has no effect on middle- or high-level clouds. Although this is still an open question (7, 8), the reduction in flux in CR in times of high solar activity is hypothesized to result in less cloud nucleation and fewer cloud condensation nuclei, and consequently, reduced low-level cloud amounts. This, in turn, leads to a higher solar radiation flux at the Earth’s surface, and warmer temperatures. Conversely, a weaker solar wind results in cooler temperatures. The actual chemical processes and reactions involved in this problem are complex, but a growing body of experimental and theoretical work has uncovered a chemical pathway by which CR ionization may increase nucleation rates to levels appropriate for cloud condensation nuclei (2–5, 9–11 and references therein). This suggests a superficially simple network linking the Sun, CR, and global climate, with the interaction between the Sun and CR having a potential influence on the climate system. However reasonable this may be, as described in a 2006 review (12), “The suggested mechanisms are, however, too complex to evaluate meaningfully at present.”     

跨角膜上皮核黄素-紫外线胶原交联的研究进展

角膜胶原交联(CXL)是一种用于治疗圆锥角膜的新技术,其主要特点是利用370nm波长的紫外线A照射核黄素产生的光敏反应来诱导角膜胶原纤维间的交联,以此提高角膜硬度,增强角膜生物力学稳定性。该方法目前已被应用于多种角膜疾病的治疗,并取得了较理想的临床疗效。但最近也有文献报道经典交联方法术前去角膜上皮所引起的一些术后不良反应和并发症。针对去角膜上皮引起的术后不良反应和并发症有学者提出了跨角膜上皮核黄素-紫外线胶原交联法。本文主要对角膜胶原交联的基本原理、操作方法、去角膜上皮的影响及近年来跨上皮交联方法的研究与应用情况进行综述。     

喜疗妥软膏联合远红外线照护对血液透析患者自体动静脉内瘘功能影响的研究

目的探讨喜疗妥软膏联合远红外线照护对血液透析的患者自体动静脉内瘘功能的影响。方法将180例采用自体动静脉内瘘进行长期血液透析患者随机分为对照组和观察组,每组90例,对照组采用局部喜疗妥软膏外涂,观察组采用局部喜疗妥外涂联合远红外线照护。比较两组患者治疗3个月后血管情况。结果观察组患者治疗3个月后,在改善内瘘血管弹性、提高血液透析患者自体动静脉内瘘透析时的血流量等方面均优于对照组,两组比较差异有显著意义（P〈0．05）。结论血液透析患者自体动静脉内瘘护理,局部用喜疗妥外涂联合远红外线照护,效果优于局部单纯用喜疗妥外涂。     

血管内皮生长因子评价伽玛刀治疗胰腺癌的疗效

目的 分析血管内皮生长因子(VEGF)水平与伽玛刀治疗胰腺癌疗效的关系,探讨其临床意义.方法 检测30例胰腺癌患者伽玛刀治疗前和治疗1个月后VEGF水平,分析其与疗效、患者生存期、生活质量的关系.结果 胰腺癌患者伽玛刀治疗前血清VEGF为(624.1±144.3)pg/ml,治疗1个月后为(279.3±83.4)pg/ml(P＜0.01).VEGF含量下降≥50%的19例中,CR+PR 18例,生活质量改善7例;VEGF下降＜50%的11例中,CR+PR 7例,生活质量改善1例,两组相差显著(P=0.012,P=0.028).随访满2年的24例患者中,VEGF下降≥50%的15例,1年生存率73.3%(11/15),显著高于VEGF下降＜50%者的22.2%(2/9,P＜0.033).结论 伽玛刀治疗后胰腺癌患者血清VEGF水平下降,其下降幅度可作为评价疗效的指标.     

氮氧化物对中波紫外线照射下包皮成纤维细胞的保护作用

目的研究中波紫外线(UVB)照射引起人包皮成纤维细胞氧化性损伤和对细胞增殖率、基质金属蛋白酶(MMP)表达的影响以及氮氧化物tempol的保护作用。方法体外原代培养的人包皮成纤维细胞接受UVB照射,同时加入或不加tempol,以生化方法检测细胞超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,以半定量RTPCR测定MMP1、MMP3mRNA表达水平。结果与未照射组比较,UVB使细胞增殖率下降至(84±8)%(P<0.05),使SOD活性降至(209.70±3.38)U/mg细胞蛋白(P<0.05),MDA堆积至(0.217±0.043)μmol/mg细胞蛋白(P<0.01),并上调了MMP1、MMP3mRNA的表达(P<0.01)。0.030～8.000mmol/Ltempol可部分甚至完全逆转上述效应,0.500mmol/Ltempol作用最强,细胞增殖率恢复至(107±15)%,SOD活性可达(287.04±8.45)U/mg细胞蛋白,MDA下降至(0.129±0.008)μmol/mg细胞蛋白,同时抑制了MMP1、MMP3mRNA的表达。结论tempol在体外对UVB引起的氧化性损伤以及成纤维细胞外基质成分过度降解有保护作用,因而有可能成为防治光老化的一种成分。     

不同剂量60 Co γ射线照射对大鼠颌下腺凋亡的影响

目的 探讨不同剂量60Coγ射线照射对大鼠颌下腺凋亡及相关因子表达的影响.方法 将Wistar大鼠随机分4组：（1）正常对照组;（2）放疗7.5Gy组;（3）放疗15 Gy组;（4）放疗22.5 Gy组.放疗组大鼠给予一次性γ射线辐射,每只辐射量按分组设定的剂量（7.5、15、22.5 Cy）给予.对照组未予照射.采用免疫组织化学法检测P53、Caspase-3表达情况以及原位切口末端标记（TUNEL）法检测细胞凋亡.结果 与对照组比较,放疗组P53与Caspase-3的表达增强.Tunel染色显示的细胞凋亡主要见于导管细胞,随着放疗剂量增加,凋亡愈明显.结论 60Co γ射线照射可引起大鼠颌下腺早期细胞凋亡.60Co γ射线（7.5、15、22.5 Gy）照射诱导的颌下腺细胞凋亡有剂量-效应关系.     

铯137辐照对库存红细胞表面分子CD35、CD47的影响

目的：探讨铯137（137 Cs）辐照对库存红细胞表面分子红细胞1型补体受体（complement receptor type 1,CR1 or CD35）及 CD47分子的影响。方法采集60例健康献血者静脉血,制备去白细胞的悬浮红细胞,并将其分为2组各30例,未辐照组常规4℃保存,辐照组采用25Gy 137 Cs辐照后4℃保存。分别于第0、7、14、28、35天收集2mL 样本。采用直标法流式细胞术检测红细胞表面分子 CD35、CD47。结果辐照组和未辐照组红细胞 CD35、CD47的表达均随着4℃保存时间的延长而减少,2组的时点间以及组间·时点间交互作用比较差异均有统计学意义（P ＜0．01）,但组间差异无统计学意义（P ＞0．05）。结论25Gy 137 Csγ射线辐照对保存期内红细胞 CD35、CD47表面分子表达无明显影响。     

《β射线所致皮肤剂量估算规范》释疑

国家职业卫生标准——《β射线所致皮肤剂量估算规范》已经卫生部批准并发布.此标准是在广泛调研国内外文献、系统学习相关法律法规和进行一些方法验证的基础上制定的.此标准主要用于β射线皮肤污染所致的皮肤剂量估算,对皮肤辐射损伤的诊断和β射线皮肤污染的去污处理都有指导意义.该文对标准的主要内容及关键性技术进行了释疑.     

Changes in aqueous humour following single or repeated UVB irradiation of rabbit cornea

Background Aqueous humour is the main nutritive source for corneal and lenticular tissues, and knowledge of a possible cumulative effect of ultraviolet radiation (UVR) on its metabolic profile might be of great help in the assessment of cataract risks. By using high-resolution ¹H nuclear magnetic resonance (NMR) spectroscopy, it was possible to evaluate the effect of a single and repeated UVB radiation of the rabbit eye with the same overall dose on the aqueous humour. Methods Samples of aqueous humour from twenty-four albino white rabbit eyes were examined for the effects of UVB exposure (312 nm). In the first group (UVB1), four animals were irradiated with a single dose 3.12 J/cm² (21 minutes) of UVB radiation. The animals in the second group (UVB2, n = 4) were irradiated three times for 7 minutes every 2nd day (dose of 1.04 J/cm²; days 1, 3, 5) to give the same overall dose (3.12 J/cm²). The third group (n = 4) served as an untreated control group. ¹H NMR spectra of aqueous humour from all eyes were obtained. Special grouping patterns among the tissue samples and relative percentage changes in particular metabolite concentrations were evaluated using appropriate statistical methods (multivariate analysis, Independent sample t-test). Results Significant alterations in the metabolic profile of aqueous humour from UVR-B exposed rabbit eyes and an apparent cumulative effect of repeated UVB irradiation were observed. Conclusions Application of a Carr-Purcell-Meiboom-Gill spin echo pulse sequence was found to have a great advantage for correct analysis of the results obtained with NMR spectroscopy of aqueous humour from eyes where increase of protein level due to an inflammatory process could not be excluded. Grants were received from: The Norwegian Quota Program The Faculty of Medicine, Norwegian University of Science and Technology The Norwegian Research Council The Grant Agency of the Czech Republic No. 304/06/1379 The Academy of Sciences of the Czech Republic AVOZ50390512.