Hypertension in the recently weaned Dahl salt-sensitive rat despite a diet deficient in sodium chloride

The Dahl rat is used as a model of hypertension that is "sensitive" to dietary salt (sodium chloride, NaCl). When dietary salt is supplemented in the Dahl rat, the arterial blood pressure of the "salt-sensitive" strain (S) becomes much greater than that of the "salt-resistant" strain (R). It has been widely reported that arterial blood pressure of the young Dahl S rat is not greater than that of the young Dahl R rat before dietary salt is supplemented. In the present study, however, mean arterial pressure directly measured in unanesthetized, unrestrained S rats was greater than in R rats, both when they had been recently weaned and for at least 10 weeks thereafter, despite their having been fed a diet frankly deficient in salt. In weanling S rats, the ratio of heart weight to body weight was also significantly greater than that in weanling R rats, suggesting that the greater blood pressure in the S rat causes cardiac hypertrophy. Thus, biologic differences demonstrated between the S rat and the R rat after weaning, including the phenomenon of salt-sensitivity, could be a consequence of, or be dependent on, an already extant difference in arterial blood pressure between the two strains.     

Metallic colloids in molten salts

Gold, silver, and silver iodide sols were prepared in mixed nitrate melts. Electron micographs of the gold and silver sols show particles smaller than 1 micron. The gold sols exhibit conventional absorption and scattering spectra. Both gold amid silver sols show unusual stability.     

亚硒酸钠 / 海藻酸钠微胶囊的制备及表征

微胶囊化包埋可减缓亚硒酸钠(Na_2SeO_3)的氧化速度。以海藻酸钠(sodiumalginate,SA)为壁材、纳米碳酸钙(Nano-CaCO_3)为交联剂,采用内源乳化法制备亚硒酸钠/海藻酸钠微胶囊(SSSAM)。借助FTIR和XRD表征,对SSSAM的结构进行分析。同时,采用单因素法,以载药率(LC)和包封率(EE)为指标,优化SSSAM的制备工艺。结果表明,采用内源乳化法成功制备了亚硒酸钠/海藻酸钠微胶囊,Na_2SeO_3以非晶态形式包埋于SSSAM中。制备工艺优化条件为Nano-CaCO_3质量比为1/2、油水体积比为4:1、Span80质量分数为3%,乳化40min,交联15min。在此条件下,SSSAM的LC和EE分别为16.2%和52.7%。     

壳聚糖金属盐抑菌效果研究

采用抑菌圈法研究了壳聚糖金属盐防霉剂对木霉Trichoderma viride,青霉Penicillamcitrinum,黑曲霉Aspergillus niger,黄曲霉Aspergillus flavus以及酵母菌Microzymesp.的抑菌作用,并筛选出最佳抑菌质量分数。结果表明壳聚糖铜盐对于所选菌种的抑制效果高于其他几种试剂,且抑制持续性也较长;质量分数为20.0 g.kg-1时,壳聚糖对木霉和酵母菌的抑菌效果特别明显,且抑制持续性也最长;壳聚糖锌盐对木霉和酵母菌的抑菌效果高于硼酸;硼酸只对黑曲霉有较长的抑制持续性。图9参11     

Dimensionality-driven insulator-to-metal transition in the bechgaard salts

Optical experiments were conducted on a series of organic linear chain conductors with different values of the interchain single-electron transfer integral tb, which quantifies the degree of anisotropy. Electron-electron interactions together with Umklapp scattering resulted in a correlation gap and an insulating state for small tb. An insulator-to-metal transition was observed when tb exceeded a critical value, on the order of the correlation gap Egap. The absence of a plasma edge on the insulator side of the transition for polarization perpendicular to the chains suggests that the electrons are confined to the chains. The optical features of the metallic state, when contrasted with the magnetic properties, are suggestive of spin-charge separation.     

3种硒化合物对刺参的急性毒性比较

在水温18℃条件下,采用Korbor法按等对数间距使用硒代蛋氨酸、亚硒酸钠、硒酸钠对规格为10、20、50 g的刺参Apostichopus japonicus进行急性毒性试验。结果表明:硒代蛋氨酸对10、20、50 g组刺参的96 h半致死浓度(96 h LC50)分别为0.639、0.741、0.795 mg/L;亚硒酸钠对10、20、50 g组刺参的96 h LC50分别为0.275、0.299、0.324 mg/L;硒酸钠对10、20、50 g组刺参的96 h LC50分别为0.305、0.346、0.368 mg/L;3种硒化合物对3种规格刺参的急性毒性大小均为亚硒酸钠>硒酸钠>硒代蛋氨酸。研究表明,在富硒海参生产中,推荐使用硒代蛋氨酸作为硒源。     

3种硒化合物对刺参的急性毒性比较

在水温18℃条件下,采用Korbor法按等对数间距使用硒代蛋氨酸、亚硒酸钠、硒酸钠对规格为10、20、50 g的刺参Apostichopus japonicus进行急性毒性试验。结果表明：硒代蛋氨酸对10、20、50 g组刺参的96 h半致死浓度(96 h LC50)分别为0·639、0·741、0·795 mg/L;亚硒酸钠对10、20、50 g组刺参的96 h LC50分别为0·275、0·299、0·324 mg/L;硒酸钠对10、20、50 g 组刺参的96 h LC50分别为0·305、0·346、0·368 mg/L;3种硒化合物对3种规格刺参的急性毒性大小均为亚硒酸钠>硒酸钠>硒代蛋氨酸。研究表明,在富硒海参生产中,推荐使用硒代蛋氨酸作为硒源。     

NaCl和Na2SO4胁迫对蒲公英种子发芽及成苗的影响

以蒲公英种子为试材，在NaCl和Na2SO4盐溶液中发芽，幼苗在持续盐胁迫条件下成苗生长。结果表明，当浓度为3500mg／kg时，NaCl和Na2SO4分别严重抑制了蒲公英种子的发芽，达到极显著水平。NaCl对种子发芽率的抑制强于Na2SO4。蒲公英成苗胁迫试验中，NaCl，Na2SO4浓度分别为5000mg／kg时，严重影响蒲公英成苗率、幼苗根、茎的生长和鲜干重比值，对叶绿素含量影响不大。种子发芽期问适当浓度的NaCl和Na2SO4盐溶液胁迫有助于诱导蒲公英幼苗耐盐性的产生。     

Neurogenic Component of Chronic Renal Hypertension

Infusion of angiotensin or renin in small quantities affects the sympathetic nervous system so that responses are increased to either drugs or reflexes that cause release of norepinephrine at nerve endings. Response to injected norepinephrine is relatively unchanged. This action of angiotensin is dependent upon an intact sympathetic nervous system. The direct vasoconstrictor action of angiotensin is not an essential part of the enhanced response. The phenomenon was shown to have relevance to acute and chronic experimental renal hypertension in dogs by the fact that in both the pressor response to tyramine was enhanced. We believe that the ability of angiotensin to intensify the effect of normal neurogenic vasomotor activity, along with an upward reset of the carotid sinus buffer mechanism, might account importantly for the neurogenic component of renal hypertension.     

槲皮素单硫酸酯钠盐和柚皮素单硫酸酯钠盐对小鼠出血时间和凝血时间的影响

目的 了解槲皮素单硫酸酯钠盐(SQMS)和柚皮素单硫酸酯钠盐(SNMS)对小鼠出血时间(BT)和凝血时间(CT)的影响.方法80只昆明小鼠随机分成8组,即生理盐水组(阴性对照),低、中、高剂量SQMS和SNMS组,血栓通组(阳性对照),每组10只.BT及CT分别采用断尾法和玻片法观察.结果 SQMS和SNMS名-剂量组...     

川芎和黄芪对大鼠妊娠期高血压疾病的影响

为了进一步开发利用川芎和黄芪,以受孕大鼠为试材,观察川芎、黄芪对大肠杆菌内毒素致妊娠高血压综合征(妊高征)大鼠血压、尿蛋白及胎盘、胎仔发育情况的影响。结果表明:与正常妊娠组比较,妊高征模型对照组尿蛋白和血压水平明显升高,说明造模成功。川芎和黄芪组与模型对照组比较,尿蛋白和血压均降低,硫酸镁阳性对照组血压比模型对照组低,尿蛋白略有下降,但差异无统计学意义。川芎和黄芪组死胎率较模型对照组明显降低,畸胎率亦显著下降。川芎、黄芪能够有效降低妊高征大鼠血压和尿蛋白,促进妊高征大鼠胎盘供血和胚胎发育。     

Synthesis of organic salts with large second-order optical nonlinearities

A series of organic salts, in which the cation has been designed to have a large molecular hyperpolarizability, has been prepared. Variation of the counterion (anion) in many cases leads to materials with large powder second harmonic generation efficiencies, the highest of which is roughly 1000 times that of a urea reference.