超导型磁共振冷头的工作原理及维护保养

冷却系统是超导型磁共振正常运行的重要保障,而冷头是磁共振冷却系统的重要组件.本文着重介绍冷头的工作原理、运行方式及其在使用中的日常维护和定期保养.     

生命探测仪电池容量检测电路的设计

介绍了基于bq2050电池容量检测电路的设计，实测结果表明此电池容量检测电路设计合理，实用有效，且精度高、体积小、功耗低，适合生命探测仪使用。     

408名社区吸毒人员操守保持的相关因素分析

目的:正确推断社区吸毒解教人员操守保持的相关因素,为制定有效的戒毒政策提供科学依据。方法:以408名长沙市芙蓉区登记在册的操守保持者为研究对象,96名复吸者为对照,比较两组吸毒解教人员的人口学、吸毒和社区帮教相关情况的差异,并进行Logistic逐步回归分析。结果:操守保持者与复吸组比较,平均年龄、首次吸毒年龄相对较大,吸毒时间相对较短,曾经使用过毒品的种类和方式相对较少,戒毒次数相对较少;而操守保持者的社会帮教率(95·6%)明显高于复吸者(53·1%),平均每年尿液毒品检测次数相对较多,低保申请率和就业安置率相对较高。多因素分析结果表明劳教戒毒次数、就业安置和年尿液检测次数是影响操守成败的主要因素。结论:社区帮教措施能够促进社区吸毒解教人员保持操守,是戒毒所戒毒工作的延续和宏观戒毒管理的一个重要方面。     

右旋柠烯对实验性乳腺增生症的影响

目的:观察右旋柠烯(d-limonene, DL)对大鼠乳腺增生及血雌激素和孕激素水平的影响.方法:苯甲酸雌二醇-黄体酮注射复制乳腺增生模型;HE染色观测乳腺组织学改变;放射免疫法检测血雌激素和孕激素水平.结果:右旋柠烯低、中、高剂量均能减少大鼠乳腺小叶数(9.20±2.32、6.90±1.20、6.10±1.37)、小叶腺泡数(8.20±1.75、6.10±2.23、5.10±1.52)和导管上皮层数(5.30±0.95、4.50±1.27、3.10±0.99),与模型组(分别为10.00±1.54、12.91±3.88和6.17±1.59)比较有显著性差异(P<0.01).右旋柠烯高、中剂量亦能降低血雌激素水平(28.35±2.16、25.17±1.25),提高孕激素水平(33.84±2.23、35.39±2.20),与模型组(分别为32.63±0.93, 31.77±1.48)比较差异显著(P<0.01),且对雌激素水平的影响有明显的量效关系.结论:右旋柠烯可抑制大鼠乳腺增生,降低血清雌激素水平、提高孕激素水平可能为其作用机制.     

中药药膜加微波照射对实验性大鼠乳腺增生的影响

目的 观察中药药膜、微波照射和药膜加微波照射对乳腺增生病的预防和治疗作用。方法 采用苯甲酸雌二醇配合应用少量黄体酮肌肉注射，建立乳腺增生病大鼠模型。于造模后2周外敷药膜和微波照射，并于给药和照射前后测量大鼠第2对乳头直径，放免法测定血清雌二醇(E2)、孕酮(P)和催乳素(PRL)浓度，镜下观察乳腺增生的病理改变，计算乳腺增生率。结果 中药药膜能显著降低实验性大鼠乳腺增生程度，抑制乳腺增生，乳腺增生率分别为23．4％和20．9％，并可调节E2和P浓度，降低PRL水平，病理组织学结果提示中药药膜组和药膜加照射组可明显减轻乳腺增生。结论 中药药膜外敷和药膜外敷加微波照射能降低乳腺增生程度，具有一定的防治乳腺增生病的作用。     

注射用对氨基水杨酸钠细菌内毒素检验探讨

用<中国药典>2000年版附录细菌内毒素检验法对PAS进行细菌内毒素检测并建立实验方法.实验结果表明用TAL试剂对PAS最大无干扰浓度为5mg/ml,无干扰作用,提示用细菌内毒素检查法检查PAS中的内毒素是可行的.     

西替利嗪凝胶的制备和质量评价

目的:制备西替利嗪凝胶剂,并建立质量控制方法.方法:以卡波姆940为基质制备凝胶,采用紫外分光光度法测定西替利嗪含量,并考察其稳定性.结果:西替利嗪线性范围为6～16 mg·L-1(r=0.996 7),平均回收率为98.23%,RSD为0.69%(n=5),凝胶稳定性良好.结论:该凝胶制备工艺可行,性质稳定.     

Ultrasound-Enhanced Protective Effect of Tetramethylpyrazine via the ROS/HIF-1A Signaling Pathway in an in Vitro Cerebral Ischemia/Reperfusion Injury Model

Reactive oxygen species-induced oxidative stress is an important pathophysiological process during cerebral ischemia/reperfusion (I/R) injury. It has been reported that the protective effect of tetramethylpyrazine (TMP) against cerebral I/R injury can be significantly improved by its combination with ultrasound exposure. However, the molecular mechanisms and signaling pathways underlying the synergistic protective effect remain unclear. In the present work, the damage induced by I/R injury was modeled by glutamate-induced toxicity to pheochromocytoma (PC12) cells. The ultrasound-enhanced protective effect of TMP was systemically investigated by measuring variations in cell viability, cell migration and levels of intracellular reactive oxygen species, the oxidative stress-related protein glutathione, apoptosis-related proteins (caspase-8, -9 and -3), as well as expression of related genes (hypoxia-inducible factor-1a, p53, murine double minute2). The results suggest that the ultrasound-enhanced protective effect of TMP against cerebral I/R injury might act via the reactive oxygen species/hypoxia-inducible factor-1a signaling pathway, and an appropriate ultrasound intensity should be selected to achieve an optimal synergistic neuroprotective effect.     

Diagnostic value of coronary CT angiography with prospective ECG-gating in the diagnosis of coronary artery disease: a systematic review and meta-analysis

To perform a systematic review and meta-analysis of the diagnostic value of prospective ECG-gating coronary CT angiography in the diagnosis of coronary artery disease. A search of biomedical databases for English literature was performed to identify studies investigating the diagnostic value of 64- or more slice CT angiography with use of prospective ECG-gating in the diagnosis of coronary artery disease. Sensitivity, specificity, positive and negative predictive value estimates pooled across studies were tested using a fixed effects model. Fourteen studies met selection criteria for inclusion in the analysis. Pooled estimates and 95% confidence interval (CI) of sensitivity, specificity, positive and negative predictive value of prospective ECG-gating coronary CT angiography for diagnosis of significant coronary stenosis were 99% (95% CI: 98, 100%), 91% (95% CI: 88, 94%), 94% (95% CI: 91, 96%) and 99% (95% CI: 97, 100%), according to the patient-based assessment. The mean values of sensitivity, specificity, positive and negative predictive value of prospective ECG-gating coronary CT angiography were 95% (95% CI: 93, 96%), 95% (95% CI: 93, 95%), 88% (95% CI: 86, 90%), and 98% (95% CI: 97, 98%), according to vessel-based assessment; 92% (95% CI: 90, 93%), 97% (95% CI: 97, 98%), 84% (95% CI: 82, 86%), 99% (95% CI: 99, 99%), according to segment-based assessment, respectively. The mean effective dose was 3.3 mSv (95% CI: 2.3, 4.1 mSv) for the prospective ECG-gating coronary CT angiography. This analysis shows that for a predominantly male population with a high disease prevalence the use of coronary CT angiography with prospective ECG gating allows for a reduced radiation exposure without a sacrifice in diagnostic efficacy.     

转化糖注射液对于神经外科危重症患者血糖的影响

目的比较神经外科危重症患者输注10%转化糖和10%葡萄糖溶液对于患者血糖水平的影响。方法选择该院40例神经外科危重症患者,在转入重症监护室(ICU)第1天分别给予10%转化糖(实验组)或10%葡萄糖溶液(对照组)1 000mL,间隔4h监测1次血糖值,同时纪录患者给药前后肝肾功能指标,比较两组血糖变化值的差异。结果实验组的血糖波动小于对照组,差异有统计学意义(P<0.05)。两组输液后肝肾功能无明显差异。两组均未出现过敏反应。结论 10%转化糖较10%葡萄糖更适合用于神经外科危重症患者血糖的控制。