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。     

Effects of exposure to air pollution on blood coagulation

BACKGROUND: Consistent evidence has indicated that air pollution increases the risk of cardiovascular diseases. The underlying mechanisms linking air pollutants to increased cardiovascular risk are unclear. OBJECTIVES: We investigated the association between the pollution levels and changes in such global coagulation tests as the prothrombin time (PT) and the activated partial thromboplastin time (APTT) in 1218 normal subjects from the Lombardia Region, Italy. Plasma fibrinogen and naturally occurring anticoagulant proteins were also evaluated. METHODS: Hourly concentrations of particulate (PM10) and gaseous pollutants (CO, NO2, SO2, and O3) were obtained from 53 monitoring sites covering the study area. Generalized additive models were applied to compute standardized regression coefficients controlled for age, gender, body mass index, smoking, alcohol, hormone use, temperature, day of the year, and long-term trends. RESULTS: The PT became shorter with higher ambient air concentrations at the time of the study of PM10 (coefficient = -0.06; P < 0.05), CO (coefficient = -0.11; P < 0.001) and NO2 (coefficient =-0.06; P < 0.05). In the 30 days before blood sampling, the PT was also negatively associated with the average PM(10) (coefficient = -0.08; P < 0.05) and NO2 (coefficient = -0.08; P < 0.05). No association was found between the APTT and air pollutant levels. In addition, no consistent relations with air pollution were found for fibrinogen, antithrombin, protein C and protein S. CONCLUSIONS: This investigation shows that air pollution is associated with changes in the global coagulation function, suggesting a tendency towards hypercoagulability after short-term exposure to air pollution. Whether these changes contribute to trigger cardiovascular events remains to be established.     

Sampling‐based estimation for massive survival data with additive hazards model

For massive survival data, we propose a subsampling algorithm to efficiently approximate the estimates of regression parameters in the additive hazards model. We establish consistency and asymptotic normality of the subsample‐based estimator given the full data. The optimal subsampling probabilities are obtained via minimizing asymptotic variance of the resulting estimator. The subsample‐based procedure can largely reduce the computational cost compared with the full data method. In numerical simulations, our method has low bias and satisfactory coverage probabilities. We provide an illustrative example on the survival analysis of patients with lymphoma cancer from the Surveillance, Epidemiology, and End Results Program.     

“气功反馈”及其机理初探

我们在分别观察气功疗法和生物反馈疗法的基础上,提出了气功反馈的概念,研制了系列气功反馈磁带,已应用于临床获得了较为满意的效果,其机制正在探讨,初步认为与大脑皮层主宰下的植物性神经整合作用有关。 1 气功反馈概念的提出近20年来西方兴起的生物反馈(biofeed-back) 是从1969年美国布朗德理和加拿大格门士治疗瘫痪肢体的生物回授法开始的,它是借助灵敏的电子仪器和微机系统,把一般不能感知的生理信息(肌电、血压及皮温等)转变成能感知的物理信息(声、光、磁     

降低隧道施工机械尾气污染的几项措施

目的　研究降低无轨运输方式施工隧道中空气污染的措施。方法　采用燃油添加剂 ,定期对施工机械进行维修和保养 ,减少发动机空档排气 ,将压入式通风口设置于距掌子面 8～ 10m处 ,保持通风管道密闭通畅致使有效送风。结果　隧道中有害气体CO、NOx及黑烟浓度至少降低 4 6 % ,55%和 4 2 %。结论　采取以上措施能明显改善施工环境的污染状况并减轻对施工人员身体健康的危害     

高原鼠兔人工饲育初探

目的 为在东北地区开发饲育高原鼠兔提供基础资料。方法 在室内人工饲育条件下,对高原鼠兔的外观、习性及食性等方面进行观察与研究。结果 高原鼠兔具有体型小、性情温顺、繁殖力强及饲料简单等特点,对低质饲料的利用率和对植物纤维的需求较高,超过家兔,更易饲养,结论 高原鼠兔在东北地区室内饲养是可以适应的。将高原鼠兔作为实验动物,有利于节省饲养空间和经费。     

The effect on the bones of condensed phosphate when used as food additives: Its Importance in Relation to Preventive Medicine

Based on the fact that chemical products such as binding agents are produced by mixing three kinds of phosphates with different ratios, we mixed metaphosphate, polyphosphate and pyrophosphate. Each was made to Na-phosphate, K-phosphate, and Ca-phosphate and each was mixed with commercial feeds so that the content of P would be approximately 0.1, 0.15, 0.3, 0.4, 0.6 and 1.0%. The prepared pellets were given to ICR, CF # 1 and AKR strains of mice at 29 days of age for 680 days and observations were made through this experimental period at different stages. The observations were also carried out on the mice administered with the experimental feeds for 1.5 months from 9 to 10.5 months of age. The observations were compared with those of the control group at all times. As a result, plasma 1 α, 25 (OH)₂ D₃ and P levels were always significantly higher in the phosphate administered groups relative to the control. Urine P and Fe increased while urine Ca decreased in the phosphate-treated groups. The effect of phosphates on the bones was studied taking soft X-ray pictures of hind legs and applying microdensitometry to them. Through these observations we recognized thinning of the cortex of bones, reduction of marrow trabecules and development of osteophyte. Histological observations disclosed that changes in knee joint tissues were apparent; that is, a decrease in or an irregular loss of the number of cells in superficial, intermediate, and radial strata of the joint cartilage, proliferation of subchondral bone, and the development of osteophytes were noted. As for muscles, diameters of musclar fibers became smaller; in particular, type II fibers showed greater shrinkage. Regarding kidneys, swelling and atrophy of glomerular capillaries, proliferation of mesangial cells, nephroselerosis, swelling, thinning, and loss of tubular epithelium, interstitial tissue inflammation, development of cylindruria, and deposition of calcium were observed. All these changes seem to be a particularly advanced aspect of the changes which are more pronounced with increasing dose and age. These changes were found even in the group administered with the feed containing 0.1% phosphorus, and, these changes were dependent on the concentration level of P. It was observed that administration to older subjects for a short term (1.5 months) produced effects stronger than those to younger subjects administered for a long term (10.5 months). The effects of condensed Ca-phosphate on bones were similar to those of condensed Na- and K-phosphates, and, hence, it was supposed that these effects were caused by phosphate radicals. An erratum to this article is available at .     

锐钛型TiO_2性能研究 I.影响化纤钛白原料性能的因素

研究了硫酸法ＴｉＯ２生产中常见杂质离子及煅烧添加剂对化纤钛白白度、光色互变性及分散性等的影响,考察了工业生产中关键单元操作对提高化钎钛白应用性能的作用。同时给出了能提高化纤钛白应用性能的煅烧添加剂配比。     

高效液相色谱法同时测定饲料中8种抗氧化剂

目的研究饲料中没食子酸丙酯(PG)、特丁基对苯二酚(TBHQ)、乙氧基喹(EQ)、丁基羟基茴香醚(BHA)、没食子酸辛酯(OG)、二丁基羟基甲苯(BHT)、没食子酸十二酯(DG)和正二氢愈创酸(NDGA)共8种抗氧化剂同时检测系统技术。方法样品提取后采用自动固相萃取方式；定量分析采用高效液相色谱-梯度淋洗-二极管阵列检测器方法进行检测。结果最低检测限为10 mg/kg；饲料中8种抗氧化荆含量在10 mg/kg时实验精密度为1．60％-10．46％；添加抗氧化剂的回收率在84％～106％；。结论该方法具有高效率,高灵敏度,准确度好,可靠性高等技术特点。