一种简单的吸入一氧化氮的输送系统

目的　　解决国内在缺乏昂贵ＮＯ浓度监测仪的情况下应用一氧化氮吸入疗法技术的难题。方法　　１７只犬随机分为二组，吸入性损伤模型成功后，对照组单纯吸氧（ＦｉＯ２，０．４５），治疗组吸氧（ＦｉＯ２，０．４５）＋０．００４５％（４５ｐｐｍ）ＮＯ。ＮＯ输送系统由三个转子流量计分别控制 Ｏ２，Ｎ２和 ＮＯ三种气体管道出口，按需调节三股气体流量比例，在呼吸回路的吸入支置钠石灰罐。 ＦｉＯ２和二氧化氮（（ＮＯ２）数据行多个样本均间方差分析，ＮＯ行两样本均数间ｔ检验。结果ＦｉＯ２实测值比预计值高１０．８％（Ｐ＞０．０５），ＮＯ２在钻石灰处理后比钠石灰处理前降低８０．２％（Ｐ＜０．０１），ＮＯ实测值比预计值高１１％（Ｐ＞０．０５）。结论　　本系统既避免了产生过高ＮＯ２的危险，同时又克服了ＮＯ浓度不恒定的缺点，能较好地满足基础实验研究。     

Positive Nitrogen Balance in Hypercatabolic States: Results Obtained with Parenteral Feeding after Major Surgical Procedures

Conclusive evidence that positive nitrogen balance can regularly be achieved during hypercatabolic states has not yet been established. Nitrogen balance has been measured in 15 patients over the first ten days following major surgical procedures whilst they were receiving parenteral alimentation with constant high caloric intake. A linear correlation was found between daily nitrogen intake and balance. The slope of the regression lines (0.430 to 0.837) and the nitrogen needs (9 to 18 g/m2 /day) vary from one patient to another. All patients were in positive nitrogen balance when intake was high, regardless of the post-operative day considered. Positive or equilibrated cumulative nitrogen balance could be obtained when mean nitrogen intake was kept over 13 g/m2 /day. This positive nitrogen balance can be obtained during hypercatabolic states. From this study and from data found in the literature it can be concluded that parenteral hype ralimentation is beneficial in the immediate post operative period after major surgical procedures.     

病毒性心肌炎患者血清一氧化氮和肿瘤坏死因子含量变化及意义

目的:探讨病毒性心肌炎(VMC)患者血清一氧化氮(NO),肿瘤坏死因子(TNF)含量的变化及其意义。方法:检测70例病毒性心肌炎患者血清一氧化氮和肿瘤坏死因子含量,选择30例健康体检者作对照组。结果:VMC患者血清NO和TNF水平明显高于对照组(P<0.01),且二者含量呈显著正相关(P<0.05)。结论:血清NO和TNF含量增加是VMC病理生理特征之一,且二者在VMC发病中具有协同作用。     

柴胡桂枝汤挥发油对Fmr1基因敲除小鼠脑组织超氧化物歧化酶和丙二醛及一氧化氮的影响

目的利用超临界二氧化碳（CO2）萃取法获取柴胡桂枝汤挥发油,并在Fmrl基因敲除小鼠（脆性基因敲除小鼠）模型上观察柴胡桂枝汤挥发油的抗癫痫作用,及其与超氧化物歧化酶（SOD）、丙二醛（MDA）、一氧化氮（NO）的关系。方法将30只30日龄的Fmrl基因敲除小鼠（KO）和30只30日龄的野生型小鼠（WT）分别分成两组（KO空白组和KO用药组,WT空白组和WT用药组）,按1．7ml／kg的剂量腹腔注射柴胡桂枝汤挥发油,观察柴胡桂枝汤挥发油对小鼠旷场行为的影响,并取不同部位的小鼠脑组织制成1：10（重量体积比）的组织匀浆,测定SOD活性及MDA、NO的水平。结果与空白组比较,用药组小鼠在旷场实验中运动的平均速度、总路程、穿过各区的次数减少：脑组织中SOD活性增高,而MDA、NO水平均降低,差异有统计学意义（P〈0．05）。结论柴胡桂枝汤挥发油对Fmr1基因敲除小鼠的探索性、兴奋性、运动性均有抑制作用;其抗癫痫作用与清除自由基、阻止过氧化物生成,减少NO的神经毒性相关。     

大鼠脑出血蛋白激酶C与细胞凋亡关系的实验研究

目的：研究大鼠脑出血后血肿周围蛋白激酶C（Protein kinase C,PKC）及神经细胞凋亡的表达及其多黏菌素B（polymyxin B PMB）对上述表达的影响。方法：将100只SD大鼠随机分为四组：假手术组、脑出血组、小剂量多黏菌素B干预组（0.4mg/kg.d）、大剂量多黏菌素B干预组（0.8mg/kg.d）,立体定位仪定位注射自体不凝血制造大鼠脑出血模型,分别为术后6h、12h、24h、72h、120h处死,免疫组织化学法检测血肿周围区PKC、TUNEL阳性细胞（凋亡细胞）数的表达、TNF-α（肿瘤坏死因子-α）含量、NO（一氧化氮）含量以及大小剂量PMB对其干预后的影响。结果：假手术组PKC少量表达,偶见凋亡细胞;脑出血组自6h起PKC、凋亡细胞及TNF-α、NO含量大量增加,72h达高峰,PKC在120h基本降至假手术组,但凋亡细胞TNF-α、NO含量仍处于较高水平,与假手术组比较差异有统计学意义（P〈0.01）;大小剂量多黏菌素B干预组均有明显抑制PKC、凋亡细胞、TNF-α含量的表达,有统计学意义（P〈0.01）;但PMB剂量的大小无明显差异性（P〉0.05）。结论：脑出血后血肿周围存在大量PKC表达上调、神经细胞凋亡、TNF-α、NO含量增加,PMB能够明显抑制PKC激活,TNF-α、NO释放,减少血肿周围细胞凋亡,起到神经元保护作用。     

甘草次酸类化合物的制备和抗肿瘤活性研究

目的制备18α-和18β-甘草次酸类复合物,并对体外抗癌活性进行研究。方法以18β-甘草次酸(Ⅰ)为起点,进行构型转化得到其光学异构体18α-甘草次酸(Ⅱ),再经C30-位羧基的甲酯化分别得到18β-甘草次酸甲酯(Ⅲ)和18-α-甘草次酸甲酯(Ⅳ),并与环磷酰胺的抗癌活性体内代谢产物——二氯磷酰氮芥偶联而得2个抗癌复合物18β-甘甲磷氮芥(Ⅴ)和18α-甘甲磷氮芥(Ⅵ);用四大光谱法(NMR、MS、IR、UV)对各化合物的化学结构进行鉴定分析;利用人类肝癌细胞株BEL-7402为体外实验模型,用MTT法观察各化合物对人肝癌细胞增殖的抑制活性;抗肿瘤药物顺铂作为阳性对照物。结果对化合物的合成工艺进行优化;18α-甘草次酸的构象转化得率为45%;目标化合物18β-甘甲磷氮芥(Ⅴ)和18α-甘甲磷氮芥(Ⅵ)的产率分别为35%和25%。所制备的甘草次酸衍生物中,化合物Ⅱ和Ⅵ对BEL-7402肿瘤细胞的增殖显示明显强的抑制活性,浓度在5～500μg/mL范围内,对肿瘤细胞增殖的抑制率分别为2.6%～86%及1.3%～50.1%;在相同条件下,对照物顺铂的抑制率为20.0%～73.41%。结论目标化合物的制备中磷酰酯化反应的条件控制(无水、物料比1∶1.25,温度65℃和反应时间3～4h)是合成关键;化合物Ⅱ和Ⅵ在中高浓度时,与顺铂具有较类似的抑制肝癌细胞增殖活性。甘草次酸类化合物的构型转化及与抗癌基团偶联可能提高其抗癌潜力。     

Pulmonary effects of inhaled diesel exhaust in aged mice

Pulmonary morbidity and mortality resulting from exposure to fine particulate matter (PM) increases with age. The present studies analyzed potential mechanisms underlying increased susceptibility of the elderly to PM using diesel exhaust (DE) as a model. Mice (2 m and 18 m) were exposed to DE (0, 300, and 1000 μg/m³) for 3 h once (single) or 3 h/day for 3 days (repeated). Bronchoalveolar lavage fluid (BAL), serum and lung tissue were collected 0 and 24 h later. Exposure to DE resulted in structural alterations in the lungs of older but not younger mice, including patchy thickening of the alveolar septa and inflammatory cell localization in alveolar spaces. These effects were most pronounced 24 h after a single exposure to the higher dose of DE. Significant increases in BAL nitrogen oxides were also noted in older mice, as well as expression of lipocalin 24p3, an oxidative stress marker in the lung with no effects in younger mice. Following DE inhalation, expression of Tumor Necrosis Factor alpha (TNFα) was upregulated in lungs of both younger and older mice; however, this was attenuated in older animals. Whereas exposure to DE resulted in increases in lung Interleukin-6 (IL-6) expression in both older and younger mice, IL-8 increased only in older animals. In younger mice, constitutive expression of manganese superoxide dismutase (MnSOD) decreased after DE exposure, while in older mice, constitutive MnSOD was not detectable and DE had no effect on expression of this antioxidant. Taken together, these results suggest that altered generation of inflammatory mediators and MnSOD may contribute to increased susceptibility of older mice to inhaled DE.     

大黄酚对铅中毒小鼠学习记忆的改善作用及其机制研究

目的研究大黄酚对铅中毒小鼠学习记忆障碍的改善作用,探讨其可能的作用机制。方法采用连续8 d腹腔注射7 mg.kg-1醋酸铅造成铅中毒小鼠模型,应用避暗实验、水迷宫实验,观察腹腔注射大黄酚(10.0、1.0、0.1 mg.kg-1)14 d对铅中毒模型小鼠记忆障碍的改善作用,大黄酚治疗14 d后测定小鼠血铅、脑铅及脑组织中MDA含量SOD,GSH-Px活力,一氧化氮(NO)含量及一氧化氮合酶(NOS)、诱导型一氧化氮合酶(iNOS)的活性。结果连续8 d腹腔注射7 mg.kg-1醋酸铅造成铅中毒小鼠学习记忆障碍,使小鼠脑铅、血铅升高,导致小鼠脑组织内SOD和GSH-Px活性降低,使小鼠脑组织内MDA含量增加,小鼠脑组织内NO含量增加,NOS和iNOS活性升高;连续ip大黄酚14d治疗后,可不同程度改善小鼠铅中毒造成的学习记忆障碍,降低血铅及脑铅水平,大黄酚(0.1 mg.kg-1)可升高铅中毒小鼠脑内SOD和GSH-Px的活性(P<0.01),对MDA含量无影响;大黄酚(10.0、1.0 mg.kg-1)可升高铅中毒小鼠脑内SOD和GSH-Px的活性,降低小鼠脑内MDA含量(P<0.01);大黄酚(0.1 mg.kg-1)可降低小鼠脑内NOS、iNOS的活性(P<0.05),对NO含量无影响;大黄酚10.0,1.0 mg.kg-1治疗组可降低小鼠脑内NO含量和NOS、iNOS的活性(P<0.01)。结论大黄酚通过提高铅中毒小鼠脑组织抗氧化酶活性同时降低NOS、iNOS的活性,抑制脂质过氧化,明显拮抗铅诱导的小鼠学习记忆障碍。     

Low overpotential reduction of dinitrogen to ammonia in aqueous media

The molecular nitrogen fixation to ammonia is one of the most important processes in chemistry. In this connection, our aim was to realize an electrochemical reaction under extremely mild conditions in an aqueous media for the first time. The reduction of dinitrogen was achieved on a polypyrrole electrode in aqueous 0.1 M Li₂SO₄/0.03 M H⁺ solution at 60 bar N₂-pressure. The reaction product was only ammonia and the ammonia formation efficiency depends strongly on the applied pressure, temperature, electrode potential, supporting electrolyte, film thickness of polymer electrode, as well as on the amount of proton source added to the electrolyte medium. The maximum yield of NH₃ was 53 μM obtained at −0.165 V_NHE after 5 h of electrolysis.     

2002-2007年深圳市关内和关外大气污染物变化规律及相关性分析

目的研究深圳市2002—2007年关内、关外大气污染物SO2、NO2、PM10空间和时间的变化规律。方法收集深圳市2002—2007年9个国控环境监测点SO2、NO2和PM10的日平均浓度,对大气污染物时间空间变化情况及大气污染物之间的相关性进行分析。结果深圳市2002—2007年关内、关外大气SO2、NO2、PM10浓度的月变化均呈"V"字型分布,即1—6月逐渐下降,6—12月又逐渐上升;关内、关外大气污染物浓度均是秋季高,夏季低;深圳市2002—2007年关内大气污染物浓度变化趋势是2002—2004年逐渐上升,2005年有所下降,2006—2007年又再次上升,而关外2002—2006年变化趋势与关内相似,而2007年并没有继续上升,反而3个指标监测值均有所下降;关外地区SO2浓度连续6a高于关内,NO2与PM10浓度关外2002—2006年连续5a高于关内,而2007年关内首次超过关外;2002—2007年深圳市关内、关外大气SO2浓度符合国家二级标准,但关内接近一级标准,NO2浓度符合国家三级标准,PM10浓度符合国家二级标准。深圳市大气SO2、NO2和PM10浓度之间存在较强的相关性。结论深圳市空...