放射性气溶胶压制剂的制备与性能

针对核活动中可能产生的放射性气溶胶污染,以聚乙烯醇为基材,丙烯酰胺为改性功能单体,采用自由基溶液聚合方法,制备出高黏度的具有交联网络结构的水溶性放射性气溶胶压制剂。通过红外光谱和核磁表征表明,丙烯酰胺与基材发生了接枝反应;通过扫描电镜测试对放射性气溶胶压制剂的微观形貌观察可知,压制剂具有交联网状多孔洞结构;经过差示扫描量热分析、热重表征,由于具有交联结构,分子链运动受阻,与均聚丙烯酰胺比较,玻璃化转变温度提高了1.48℃,熔点降低了9.81℃,初始分解温度提高了18.12℃,无序性增大,结晶性减弱,热稳定性增强;模拟喷淋雾化试验测试其压制效果,黏度为1755 m Pa·s的压制剂效果可达到68.54%。

P(AM-co-AA)放射性气溶胶压制剂的制备及表征

以丙烯酸(AA)、丙烯酰胺(AM)为反应单体,在水溶液中采用自由基聚合法制备得到一种可用于放射性气溶胶粉尘快速去除的聚合物溶液。通过红外、核磁、热重、扫描电镜、表面张力、接触角测试方法对产物的结构及性能进行了测定,结果表明:丙烯酰胺与丙烯酸反应生成了共聚物P(AM-co-AA);聚合物在水相中呈现出多孔的交联结构,其结构形态与单体配比有相关性,其中,n(AA)∶n(AM)=1∶9的压制剂更容易与气溶胶粉尘结合;所制压制剂对气溶胶粉尘有较好的润湿性,且不同单体配比的压制剂对气溶胶粉尘的润湿性有影响,当n(AA)∶n(AM)=3∶7时,压制剂与气溶胶粉尘的接触角最小,为64.3°;模拟雾化喷淋实验测试其压制效果表明:与自然沉降法相比,n(AA)∶n(AM)=1∶9的压制剂将气溶胶粉尘浓度降为原始值一半所用的时间从9.4 min缩短到了2.0 min,大大加速了气溶胶粉尘的沉降,且具有明显的压制效果。

中药缓压乐复方制剂对应激性高血压大鼠心肌组织受磷蛋白磷酸化水平的调节作用

目的探讨中药缓压乐复方制剂对应激性高血压(stress induced hypertension,SIH)大鼠心肌组织受磷蛋白(Phospholamban,PLB)磷酸化水平的调节作用。方法用复合应激因素建立SIH大鼠模型的基础上,以中药缓压乐复方制剂进行干预。采用实时荧光定量PCR(RT-qPCR)和免疫组织化学方法分别检测SIH模型组、正常组、药物干预组和阴性对照组大鼠心肌组织内源性抑制剂1(endogenous inhibitor 1,I-1)基因mRNA表达以及PLB蛋白的磷酸化水平。结果与正常组相比,模型组大鼠心肌组织I-1基因mRNA表达水平明显下调(P<0.05),用药物干预后明显上调(P<0.05);与正常组相比,模型组大鼠心肌组织PLB蛋白磷酸化水平明显下调(P<0.05),而用药物干预后明显上调(P<0.05)。结论中药缓压乐复方制剂可能通过PLB磷酸化水平的上调,增强SERCA2a蛋白的活性,从而增加肌质网对Ca^2+的重吸收。

缓压乐复方制剂干预对应激性高血压大鼠血浆醛固酮的调节作用研究

目的探讨缓压乐复方制剂对应激性高血压(SIH)大鼠血浆醛固酮含量调节的作用。方法选取造模成功的SIH模型大鼠20只,采用完全随机分组的方法分为阴性对照组(n=10)和药物干预组(n=10),阴性对照组大鼠与药物干预组大鼠每天分别灌胃蒸馏水和缓压乐复方制剂(1 mL/100 g体质量),干预期间同时施予2组大鼠间断足底电声光持续应激刺激4周,并进行一次血压测量;采用放射免疫分析方法检测药物干预后大鼠血浆醛固酮含量,酶联免疫吸附(ELISA)方法检测药物干预后大鼠血清肾上腺素含量,RT-qPCR和免疫组织化学方法分别检测药物干预后大鼠肾上腺组织环磷酸腺苷反应元件结合蛋白(Creb)、醛固酮合酶(Cyp11b2)基因mRNA表达水平及CREB蛋白磷酸化与CYP11B2蛋白表达水平的变化。结果与阴性对照组比较,药物干预组大鼠收缩压与舒张压均明显降低(P<0.05);血浆醛固酮含量明显下降(P<0.05),血清肾上腺素含量无明显变化(P>0.05),肾上腺组织Creb基因、Cyp11b2基因mRNA表达水平明显下调(P<0.05),肾上腺CREB磷酸化及CYP11B2蛋白表达水平明显下调(P<0.05)。结论缓压乐复方制剂可能通过降低SIH模型组大鼠血浆醛固酮含量从而降低血压。

APPLICATION POSSIBILITY OF BINARY NONAZEOTROPIC REFRIGERANT IN JET REFRIGERATION *

This paper analyzes the possibility of applying binary nonazeotropic refrigerants in the jet refrigeration cycle. The thermodynamic cycle performance of two kinds of working pairs (R30/R142b, R30/R124) are calculated using the EOS of PR equation of state, and the results are discussed. The theoretical calculations indicate that refrigerating quality can be improved if the binary mixtures evaporate just in the low temperature region. The character of the rejecter to compress two phase medium supports the possibility of this kind of cycle.

A Clinical Study on Haunglian Fire-Purging Mixture In Treatment of 46 Cases of Primary Hypertension

In order to observe the therapeutic effects of Huanglian Fire-Purging Mixture (黄连清降合剂) on primary hypertension, 46 cases of primary hypertension in the treatment group were treated with Huanglian Fire-Purging Mixture to clear away heat from the liver, relieve mental stress, purge fire and remove toxin;and the other 26 cases of primary hypertension in the control group were treated with Niuhuang Bolus for Lowering Blood Pressure (牛黄降压丸). The effect in the treatment group was obviously superior to that in the control group (P＜0.05). The Huanglian Fire-Purging Mixture shows noticeable effects 3-6 hours after medication. The mixture can improve the clinical symptoms, the left ventricular diastolic function and myocardial ischemia, correct dyslipoproteinemia and dysglycemia, and reduce blood viscosity. And it is safe and with no obvious adverse reactions.

Optimization of angiotensin I-converting enzyme (ACE) inhibition by rice dregs hydrolysates using response surface methodology

Angiotensin I-converting enzyme (ACE) inhibitory peptides have been shown to have antihypertensive effects and have been utilized for physiologically functional foods and pharmaceuticals. The ACE inhibitory ability of a hydrolysate is de- termined by its peptide composition. However, the peptide composition of a hydrolysate depends on proteolytic enzyme and the hydrolysis conditions. In this study, the effect of process conditions on the ACE inhibitory activity of rice dregs hydrolyzed with a trypsin was investigated systematically using response surface methodology. It was shown that the ACE inhibitory activity of rice dregs hydrolysates could be controlled by regulation of five process conditions. Hydrolysis conditions for optimal ACE inhibition were defined using the response surface model of fractional factorial design (FFD), steepest ascent design, and central composite design (CCD).

Depressing effect of phenoxyl acetic acids on flotation of minerals containing Ca^(2+)/Mg^(2+) gangues

Phenoxyl acetic acids were applied to determine their depressing effect on minerals containing Ca2+/Mg2+ gangues. Calcite, mixture of calcite and fluorite, and nickel ore were used in the flotation. And the depression mechanism was studied by the determination of contact angle, zeta potential, adsorptive capacity of collector, and IR analysis as well. It is found that 0.1 mmol/L of phenoxyl acetic acid derived from pyrogallol or gallic acid exhibits strong depressing ability on calcite in almost zero yields at pH value of 9.8, and calcite can be depressed in the flotation of calcite/fluorite mixture for approximate 87% yield of fluorite. The flotation result of practical nickel ore containing serpentine indicates that these two depressants may also show better depression performance to serpentine than traditional depressants such as sodium fluosilicate and carboxylmethyl cellulose. Analysis for the depression mechanism reveals that there exists strong chemical interaction between the depressants and minerals.

Development of High Efficiency Swing Compressor for R32 Refrigerant

In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC （heating ventilation and air conditioning） units. We chose R32 refrigerant, with its lower LCCP （life cycle climate performance） as a more sustainable choice than R410A. However, R32 has its drawbacks. Due to its smaller molecular weight, internal leakage loss is higher for R32. Moreover, high discharge gas temperature decreases the reliability of the compressor, and makes a large overheating loss increase. In this study, we will describe the technologies （reducing the piston pressurizing force, heat-insulating structure, optimizing the port diameter） that were developed to overcome these drawbacks. We will also oresent the performance and reliability of the newly develoned high efficiency swing, comnressor series for R32 refrigerant.

Cooling of Superheated Refrigerants Flowing inside Tubes Filled with Porous Media： Study of Heat Transfer and Pressure Drop, Carbon Dioxide Case Study

In this work an experimental study combined with an analytical investigation for cooling superheated Carbon Dioxide （CO2） gas were carried out. This work is intended to be part of the super critical Gustav Lorentzen refrigeration cycle of CO2. Experimental and analytical works concentrated on heat transfer and pressure drop for single phase flow during gas cooling inside tubes filled with porous media. Analytical empirical correlations were formulated for the coefficient of convectional heat transfer and for the pressure drop. A comparison between experimental results and that obtained by developed correlations were carried out, and a comparison between these results and literature published ones were carried out too. The results of this research showed that for cooling process the proposed correlations were proved to be acceptably accurate for pressure drop with difference from experimental results of 2%, while for convective heat transfer the difference from experimental results reached about 3%. More than 90% agreement with literature results was obtained. This work can enhance the calculations of heat flux and pressure drop of gases flow inside porous media filled tubes, and can help in the design procedure of heat exchangers and cooling processes.

Statins role in cancer prevention and development-recent meta-analyses

The therapeutic indications of 3-hydroxy-3-methylgl-utaryl-coenzyme A （HMG-CoA） reductase inhibitors （statins） include hypercholesterolaemia and the pre-vention of cardiovascular events. Statins are well toler-ated and beyond their unambiguous positive cardio-vascular effects there are a steadily increasing number of pleiotropic actions emerging. In this regard, growth inhibition, apoptosis, anti-infammatory and immuno-modulatory actions have been attributed to statins. The anti-proliferative effects have been the basis for massive preclinical investigations to elucidate a func-tional role for statins in carcinogenesis and tumor cell growth. However, preclinical and clinical studies are conflicting, although there is accumulating evidence that statins are capable to suppress and decrease the incidence and recurrence of some human cancers. Giv-en the fact that statins are well tolerated they might also have some impact in combinations with conven-tional and targeted chemotherapy. While synergism has been shown for many combinations in vitro this does not hold true yet in the clinics. Here we review the rational behind usage of statins in oncological set-tings. Positive effects have been observed in patients with melanoma and cancers from the breast, colon, prostate, lung, liver and hematologic tissues. However, substantial evidence from clinical studies is still weak and confounded by several factors, which are inherent in the study design. The majority of the studies are ob-servational or of retrospective nature. Defnitely, there is substantial need for larger, prospective randomized, placebo-controlled trials. Finally, we conclude that statins at the current status of evidence should not be recommended in the prevention or during progression of any cancers, however, individual statins may have benefcial effects in specifc tumor subgroups.

A Meta-analysis of angitensin-converting enzyme inhibitors on normotensive early diabetic renal diseases

Objective: To make a systematic assessment on whether the progression of early diabetic renal disease with normotension may be slowed down by angiotensin-converting enzyme (ACE) inhibitors. Methods: Randomized clinical experiments published on MEDLINE from January 1990 to April 1999 and on China Biological Medicine were reviewed for studying the effects of ACE-inhibitors on normotensive patients with early diabetic renal diseases. Based on the inclusion criteria, 10 studies were selected. Their results were combined and analyzed with RevMan3. I software. Results: The pooled effect of urinary microalbumin excretion rate, systolic blood pressure, diastolic blood pressure and mean arterial blood pressure were -77.502 mg/24 h (-100.748 to-54.256), -5.002 mmHg [-9.630 to 0.685],-2.949 mmHg (-4.005 to 1.892). -4.284 mmHg (-5.444 to 3.123) respectively. Using clinical albuminuria as the end-point, the pooled odd ratio was 0.27 [95% CI 0.18 0.40]. The sub-group analysis showed that those results had no difference between type 1 and type 2 diabetes. There was no significant correlation between the pooled effects of urinary micro-albuminuria excretion rate and systolic blood pressure. diastolic blood pressure or mean arterial blood pressure. Conclusion: ACE inhibitors can decline urinary micro-albuminuria excretion rate in normotensive patients with early diabetic renal disease and delay the progression of early diabetic renal disease to clinical albuminuria. These effects may not be dependent on its blood pressure-reduction effect.

Proton pump inhibitor step-down therapy for GERD:A multi-center study in Japan

AIM:To investigate the predictors of success in stepdown of proton pump inhibitor and to assess the quality of life(QOL).METHODS:Patients who had heartburn twice a week or more were treated with 20 mg omeprazole(OPZ) once daily for 8 wk as an initial therapy(study 1).Patients whose heartburn decreased to once a week or less at the end of the initial therapy were enrolled in study 2 and treated with 10 mg OPZ as maintenance therapy for an additional 6 mo(study 2).QOL was in-vestigated using the gastrointestinal symptom rating scale(GSRS)before initial therapy,after both 4 and 8 wk of initial therapy,and at 1,2,3,and 6 mo after starting maintenance therapy.RESULTS:In study 1,108 patients were analyzed.Their characteristics were as follows;median age:63(range: 20-88)years,sex:46 women and 62 men.The success rate of the initial therapy was 76%.In the patients with successful initial therapy,abdominal pain,indigestion and reflux GSRS scores were improved.In study 2,83 patients were analyzed.Seventy of 83 patients completed the study 2 protocol.In the per-protocol analysis,80%of 70 patients were successful for stepdown.On multivariate analysis of baseline demographic data and clinical information,no previous treatment for gastroesophageal reflux disease(GERD)[odds ratio (OR)0.255,95%CI:0.06-0.98]and a lower indigestion score in GSRS at the beginning of step-down therapy(OR 0.214,95%CI:0.06-0.73)were found to be the predictors of successful step-down therapy.The improved GSRS scores by initial therapy were maintained through the step-down therapy.CONCLUSION:OPZ was effective for most GERD patients.However,those who have had previous treatment for GERD and experience dyspepsia before stepdown require particular monitoring for relapse.

HYPERTENSION IN RENAL ALLOGRAFT RECIPIENTS

Objective To further evaluate the effect of hypertension on renal graft function, and the relationship between hypertension, hyperlipoidemia and ischemic heart disease. Methods 102 renal transplant recipients with a functioning renal graft for more than 1 year were enrolled in this study. Renal function was followed for the further 24 months. Results The overall prevalence of hypertension was 89.2%(91/102) and 36.2%(33/91) hypertensive patients had uncontrolled blood pressure. After 24 months those with high blood pressure had significantly higher Scr levels than normotensive patients (P<0.05). The number of different antihypertensive classes required was related to Scr (P<0.05). Plasma cholesterol levels in hypertension patients especially in blood pressure uncontrolled group were significantly elevated (P<0.01). Ischemic heart disease was more common in hypertensive patients (P<0.05). Cyclosporine A was associated with hypertension more frequently than azathioprine and FK506, whereas low-dose prednisolone did not appear to influence blood pressure. Conclusion The data further confirmed that hypertension was associated with hyperlipidemia and ischemic heart disease, and emerged as a predictor of renal graft dysfunction. Whether cyclosporine A should be converted to new immunosuppressive agents and which class of antihypertensive medication is more effective in this population remain open questions.

NEW FLUOROSILOXANE AS A COATING MATERIAL FOR NERVE AGENT SENSORS

Polymer coated quartz crystal microbalance (QCM) sensor based on the frequency shifts due to the adsorption of compounds at the surface of modified quartz crystal electrode is an effective method for detection of sarin (GB) which is a highly toxic nerve warfare agent. A new fluorosiloxane polymer has been synthesized through 6 steps from trifluoromethyl benzene. The synthesis was achieved from trifluoromethyl benzene through nitration, hydrogenation. The obtained m-nitrotrifluoromethyl aniline was treated with NaNO2, and then hydrolyzed to m-nitrotrifluoromethyl phenol. m-nitrotrifluoromethyl phenol was reacted with allyl bromide to the ether product. The product was rearranged by Claisen rearrangement, and then reacted with polymethylhydrosiloxane under catalyst of Pt/DVTMS. The fluorosiloxane polymer can be obtained. The polymer has been successfully used as QCM coating material.

Nickel Catalyzed High-Pressure Hydrothermal Processing of Biomass for H2 Production

In this study, high-pressure hydrothermal processing of different biomass sources and products, which include cellulose, xylan, lignin, pine wood, paper waste, and waste lignin was performed at 200-275 ℃ in presence of NiSO4 catalyst. Biomass slurry was prepared in distilled water containing NiSO4, loaded in a high-temperature high-pressure reactor and heated to different temperatures. The reaction was continued for 120 min and during the reaction gas samples were withdrawn and analyzed using Chrompack capillary column on the gas chromatograph equipped with thermal conductivity detector. The analysis of gas samples revealed the presence of H2, CO2, CO, and CH4 gases. Increase in catalyst concentration from 3 wt% to 10 wt% has significantly increased the H2 generation. Absence of catalyst, however, generated almost negligible amount of H2. Among the biomass sources and products investigated here, xylan has yielded maximum amount of H2. The liquid samples were analyzed by high-performance liquid chromatography （HPLC） and Fourier transform infrared （FTIR） spectroscopy which revealed the presence of sugars along with the other intermediates.

Performance of a single-stage Linde-Hampson refrigerator operating with binary refrigerants at the temperature level of-60°C

The optimization of the performance of a single-stage Linde-Hampson refrigerator （LHR） operating with six different binary refrigerants （R23/R134a, R23/R227ea, R23/R236ea, R170/R290, R170/R600a and R170/R600） with ozone depletion potentials （ODPs） of zero was conducted using a new approach at the temperature level of-60℃. Among these binary refrig- erants, the 0.55 and the 0.6 mole fractions of R23 for R23/R236ea are the most prospective nonflammable ones for the medium and low suction pressure compressors, respectively. For these two kinds of compressors, the 0.6 and the 0.65 mole fractions of R170 for R 170/R600, respectively, are the most prospective binary refrigerants with low global warming potentials （GWPs）. The results of optimization of pressure levels indicate that the optimum low pressure value for coefficients of performance （COP） is achieved when the minimum temperature differences occur at both the hot and the cold ends of the recuperator at a specified composition and pressure ratio. Two useful new parameters, the entropy production per unit heat recuperated and the ratio of heat recuperating capacity to the power consumption of the compression, were introduced to analyze the exergy loss ratio in the recuperator. The new approach employed in this paper also suggests a promising application even to the optimization of the performance with multi-component refrigerants.

Study on the Mechanism of Compound Mistletoe Fluidextract in Relieving Hypertension

To observe the effect of Fufang Jisheng Liujin Gao （复方寄生流浸膏 Compound Mistletoe Fluidextract） on blood pressure in the spontaneous hypertensive rats （SHR） and the renal hypertensive dogs （RHD）. Methods： The blood pressure-decreasing effects of single administration and 14-day consecutive administration of Compound Mistletoe Fluidextract （CMF） in SHR and RHD were investigated and compared with that of Niuhuang Jiangya Wan （牛黄降压丸 Bezoar Hypertension-relieving Pills）. Results： Both single administration and 14-day consecutive administration of CMF had significant hypotensive effects in SHR and RHD. Conclusion： The hypotensive action of CMF is gradual, but lasts for a longer period, with a dose-effect relationship in a range of doses.