An experimentally supported, mathematical explanation of the gas chromatographic elution behaviour of the long-chain carbon members of the homologous series

By substituting the saturated vapour phase tension of the pure normal hydrocarbons described by the Clausius-Clapeyron law into the accepted expression of the specific retention volume (V_g,T), a theoretically coherent and relatively simple mathematical evidence of the elution behaviour of the homologous members has been deduced. It gives exponential retention time dependence on carbon number for isothermal, and nearly equidistant (i.e., approximately linear retention-time dependence on carbon number) elution for linear temperature programmed gas chromatographic runs. The final equations are in close correlation with the experimental results. Special emphasis is placed on the fact that a good approximation—not strict physical laws—have been found.     

存样食物在追查食物中毒源头中的作用

[目的]针对食物中毒事件追查源头的困难局面,探索1种新的食物中毒追查方法。[方法]通过分析各种常见类型食物中毒的潜伏期,结合各种实际情况,探讨存样食物保存的时间和方法。[结果]存样食物至少要保存24h。[结论]这种存样待检方法有其先进性,但仍存在不少问题,需进一步改进。     

Content of HSP70 in rats with hereditary stress-induced arterial hypertension

Sensitivity of normotensive Wistar rats and NISAG rats (with hereditary arterial hypertension) to heat stress is compared at the organism and cell levels. High temperature sensitivity of NISAG rats correlates with a low content of the main heat shock protein HSP70. This relationship can serve as a biochemical marker of predisposition to arterial hypertension. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 8, pp. 171–173, August, 1997     

Agilent 2100 Bioanalyzer在基因差异表达研究中的应用

目的观察Agilent 2100 Bioanalyzer 芯片分析系统(以下简称Bioanalyzer)在基因差异表达研究中的应用。方法应用限制性显示技术分别从正常和热休克处理后的酿酒酵母细胞中分离出cDNA片段,然后再用Bioanalyzer和传统的琼脂糖凝胶电泳技术对RD-PCR产物进行检测分析。结果Bioanalyzer能更快速、敏感地分离和显示差异表达的基因片段,并且通过对差异片段进行定量比较,发现了数个表达有明显差异的基因片段。结论Bioanalyzer在基因差异表达研究中具有重要的应用价值。     

一种简单、稳定、可靠的屏氧酶1基因多态性分析法

目的：建立一种简单、稳定、可靠的PON1基因多态性分析法。方法：取外周静脉血100μl，用ROSE法提取基因组DNA，用两对引物：P192F 5′-TAT TGT TGC TGT GGG ACC TGA G-3′,P192R 5′-CAC GCT AAA CCC AAA TAC ATC TC-3′；P55F 5′-GAA GAG TGA TGT ATA GCC CCA G-3′,P55R 5′-TTT AAT CCA GAG CTA ATG AAA GCC-3分别进行PCR扩增，用限制性内切酶AlwI,NlaⅢ对两种PCR产物分别进行酶切，3％琼脂糖凝胶电泳。结果：扩增的两个PCR产物在192、55多态性位点大小分别为99bp、170bp。Alw I酶切后，凝胶电脉得到完全酶切（66bp,33bp)，部分酶切（99bp、66bp、33bp)，未被酶切（99bp)三种类型DNA片段（RR，QR，QQ基因型）；NlaⅢ酶切后，凝胶电脉得到部分酶切（170bp,126bp,44bp)，未被酶切（170bp)两种类型DNA片段（LM，LL基因型）。经双盲重复检测，结果一致。应用此方法对胃癌患者血样标本检测，发现其PON1基因多态性在192位点频率较高。结论：采用一步PCR－RFLP技术可以建立简单、稳定、可靠的PON1基因多态性分析法。     

妇女叶酸增补中需要关注的问题

妇女围孕期增补叶酸能够有效预防神经管缺陷等疾病的发生。随着对叶酸研究的不断深入，叶酸补充中出现了诸多问题。本文简要综述了叶酸在服用方式以及基础和临床研究中出现的值得讨论、已经引起关注和需要进一步研究探讨的问题，并提出了深入研究叶酸可能的发展趋势。     

食品添加剂KAl（SO4）2中Al的吸收,排泄,蓄积实验研究

目的：探讨我国主要含铝食品添加剂——硫酸铝钾中铝的吸收、排泄和贮留的基本情况。方法：１．采用６月龄日本雄性大耳兔８只进行３天的代谢平衡实验。２．选用２～３月龄２１只雄性兔进行３２周的蓄积实验。结果：代谢实验表明铝的表观吸收率平均在１０％左右，约９０％的口服铝在粪中排出。尿铝随摄入铝的增加而增加，但肾排铝能力不足吸收的１０％。兔的蓄积实验证明在３２周实验后实验兔随铝摄入的增加其主要脏器均有不同程度的铝蓄积。其蓄积量的顺序为：骨＞肝＞肾＞脑＞心（３．８９～１０５．４６ｍｇ／ｋｇ干重）；蓄积增长倍数为：肝＞脑＞肾＞骨＞心（１．５１～４．５８倍）。结论：１．食品添加剂硫酸铝钾中铝的表观吸收率平均在１０％左右。尿铝随摄入铝的增加而增加，但肾排铝量不足吸收的１０％。２．长期大量摄入含铝食品添加剂可导致机体铝蓄积，其中脑、骨、肝、肾蓄积较明显。     

An estimate of phylogenetic relationships among culicine mosquitoes using a restriction map of the rDNA cistron

Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa.     

RENIN GENE POLYMORPHISM ASSOCIATED WITH ALDOSTERONE RESPONSIVENESS TO THE RENINANGIOTENSIN SYSTEM IN PATIENTS WITH ALDOSTERONE-PRODUCING ADENOMAS

1. Aldosterone levels in patients with unilateral aldosterone-producing adenomas may be responsive or unresponsive to the renin-angiotensin system, with the former often previously misdiagnosed as bilateral adrenal hyperplasia. 2. In tumours from patients in the responsive subgroup, renin mRNA is expressed in greater amounts than in tumours from patients in the unresponsive subgroup, or in normal adrenals. 3. We compared the frequency of four renin gene polymorphisms in peripheral blood DNA from the two subgroups and found significant associations between BglI, TaqI and HinfI restriction fragment length polymorphisms (RFLP) and aldosterone responsiveness. 4. Allelic variation in the constitutive renin gene was associated with a specific cause of hypertension.     

中国汉族群体D4S111位点的遗传多态性研究

目的：研究中国汉族群体中α艾杜糖苷酶基因Ｄ４Ｓ１１１位点的遗传多态性。方法：采用扩增片段长度多态性（ＡｍｐＦＬＰ）分析技术，检测了广州地区汉族无血缘关系健康个体９７名。结果：Ｄ４Ｓ１１１位点，在９７名无关个体中发现５个等位基因和９种基因型，等位基因片段长度为８３０～５１０ｂｐ，基因频率为０００５２～０３６０８，ＰＩＣ为０５９６６，杂合性为０７８。结论：中国汉族群体中Ｄ４Ｓ１１１位点具有高度多态性，并与其它种族间存在差异性。