川连抗癌的实验研究

目的通过对动物体内抗癌实验的观察研究,验证中药川连具有抑制和治疗肿瘤的生物学特性。方法选取80只昆明小鼠,于前肢皮下接种小鼠肉瘤细胞。将动物随机分为对照组和川连治疗组。治疗组每日给予川连汤剂稀释液（0．5mg,瘤内注射,1次／d）,连续10d;对照组注射同体积生理盐水。结果连续观察70d,治疗组小鼠存活率100％,对照组小鼠存活率为0％。结论中药川连具有抑制和治疗肿瘤作用,其抗肿瘤作用机制有待于进一步研究。     

In search of the Chinese self: An fMRI study

Cultural influences on the concept of self is a very important topic for social cognitive neuroscientific exploration, as yet, little if anything is known about this topic at the neural level. The present study investigates this problem by looking at the Chinese culture's influence on the concept of self, in which the self includes mother. In Western cultures, self-referential processing leads to a memory performance advantage over other forms of semantic processing including mother-referential, other-referential and general semantic processing, and an advantage that is potentially localizable to the medial prefrontal cortex (MPFC). In Chinese culture, however, the behavioral study showed that mother-referential processing was comparable with self-referential processing in both memory performance and autonoetic awareness. The present study attempts to address whether similar neural correlates (e.g. MPFC) are acting to facilitate both types of referencing. Participants judged trait adjectives under three reference conditions of self, other and semantic processing in Experiment I, and a mother-reference condition replaced the other-reference condition in Experiment II. The results showed that when compared to other, self-referential processing yielded activations of MPFC and cingulate areas. However, when compared to mother, the activation of MPFC disappeared in self-referential processing, which suggests that mother and self may have a common brain region in the MPFC and that the Chinese idea of self includes mother.     

“酒精对水蚤心率的影响”实验的探究

对不同浓度的酒精在不同时间对水蚤心率的影响进行了探究,提出了实验建议。     

An experimental study on the effect of rigid fixation on the developing craniofacial skeleton

Rigid fixation of the craniofacial skeleton has proven of great value in adult orthognathic and traumatic reconstructive surgical procedures. This technique has gained increased acceptance in the surgical treatment of infants and young children with congenital malformations, despite the fact that its effects on subsequent craniofacial growth are unknown. To examine this question, an experimental model using 25 young kittens was developed to compare rigid fixation with conventional wire fixation, with and without osteotomy. Our findings demonstrate a regional restriction of growth in the developing craniofacial skeleton when both wire and plate and screw fixation are utilized in concert with osteotomy. Further, a compensatory growth was observed in individual animals when plate fixation was utilized that was not seen in the wire-treated group. This suggests that there is a dynamic growth interaction between restriction and compensation in this setting.     

An experimental study on the effect of humidity on thermal sensations of people in summer

1. 1. The authors propose humidity reduction instead of lowering room temperature in order to reduce cooling syndrome.

2. 2. They conducted experiments with subjects in the rooms, one with controlling humidity to about 40% r.h. and another without humidity control. Air-conditioning system with humidity control has a greater promise in making a comfortable environment, even at the temperature as high as 30°C, in comparison with conventional means using temperature control alone.

3. 3. Relationship of actual mean votes on temperature sensation and comfort sensation with PMV and SET, respectively, suggests that Japanese people might be more sensitive to humidity than Westerners and so different methods from those used in the western countries should be required for human thermal environmental studies with respect to the hot humid summer in Japan.

The effect of maternal Naja nigricollis envenomation on the placenta. An experimental study

The effect of maternal envenomation with N. nigricollis venom on the placental tissues was studied in mice. The venom seemed to exert a direct toxic effect on the constituent parts of the placenta. Glycogen appeared to advantage in the cells of the trophospongeal part of the placenta. Giant cells and basophilic cells were encountered around such glycogen cells. However, some giant cells showed vacuolation of the cytoplasm and pyknosis of the nuclei. The labyrinthine part of the placenta showed large and multiple small thrombi and congestion of the blood spaces. Again glycogen appeared to advantage in the syncytial cells. Non cellular exudate was also met with in such cases. The possible mechanisms of these changes were discussed.     

An experimental study on the function of fibrocytes

By means of different types of fibrocytes (amnion connecting cells, fibrocytes of the substantia propria of the cornea, fibrocytes of the tendon, fibrocytes of the loose connecting tissues and fibrocytes of the ovary a varying disposition could be demonstrated for the accumulation of vital dies. The tests indicate that the transformation of fibrocytes into histiocytes (macrophagia) can be shown with certainty only in the less differentiated connected tissue cells of the amnion.     

镉对黑斑蛙精巢组织结构的毒性效应

为了研究镉对两栖动物精巢组织结构的影响,用不同浓度Cd2 溶液对黑斑蛙(Rana nigromaculata)成体隔日皮下注射染毒,光镜下观察精巢组织的显微结构变化。结果表明,镉具有毒性效应,可以导致处理后的黑斑蛙精巢组织中的各级生精细胞、支持细胞和间质细胞受到损伤。对处理组和对照组的精巢组织分别用金属硫蛋白(MT)进行免疫组化定位观察,MT阳性颗粒在处理组和对照组均有表达,表达随处理组镉浓度的增大而减弱。     

双歧啤酒预防性减肥作用的实验研究

目的探讨双歧啤酒预防大鼠肥胖的作用及其对大鼠血脂、瘦素和胰岛素的影响。方法48只SD大鼠被随机分成双歧啤酒低剂量组[12．5ml／（kg·BW）]、中剂量组[25ml／（kg·BW）]、高剂量组[50ml／（kg·BW）]和市售啤酒组[25ml／（kg·BW）]、肥胖模型组以及基础组,进行预防性减肥实验,观察双歧啤酒在大鼠致肥过程中对大鼠的影响,测定指标包括大鼠体重、体脂、脂肪细胞直径、血脂水平和血瘦素、血胰岛素。结果实验结果显示,双歧啤酒各组除TCHO外的所有测定指标值都较肥胖组有明显好转,特别是腹膜下脂肪重量、TG和HDL水平都与正常组差异无显著性,低、中剂量组脂肪细胞直径也与正常组差异无显著性。市售啤酒组所有指标均与肥胖模型组差异无显著性。结论双歧啤酒能有效预防血TG的升高,有效预防啤酒肚的形成。对于预防体脂和体重的增加也有一定作用。     

An experimental study of baseline reproducibility and its effect on high-speed sedimentation equilibrium data

Baseline variability is an important source of error in molecular weight determination with the high-speed sedimentation equilibrium method when Rayleigh interference optics are employed. Using Yphantis-style six-channel cell assemblies (1), we have measured this variability under several conditions at 32,000 rpm and below. These measurements have led to the conclusion that the baseline for speeds up to at least 32,000 rpm should be measured from a picture taken at low speed at the end of the high-speed experiment.     

An experimental study of the dielectric dispersion of solutions of cytochrome c at medium ionic strengths

In this paper, the results are presented of measurements of the dielectric dispersions of horse heart cytochrome c molecules in various buffers. The data are fitted to the Cole-Cole relaxation model. The influence of the concentration and the ionic strength on the parameters that result from the Cole-Cole model is determined. The measured data are compared with calculations based on the model presented previously. Good agreement is found between the model and the observed data.     

Loss of cytosolic Mg2+ binding sites in the Thermotoga maritima CorA Mg2+ channel is not sufficient for channel opening

The CorA Mg²⁺ channel is a homopentamer with five-fold symmetry. Each monomer consists of a large cytoplasmic domain and two transmembrane helices connected via a short periplasmic loop. In the Thermotoga maritima CorA crystal structure, a Mg²⁺ is bound between D89 of one monomer and D253 of the adjacent monomer (M1 binding site). Release of Mg²⁺ from these sites has been hypothesized to cause opening of the channel. We generated mutants to disrupt Mg²⁺ interaction with the M1 site. Crystal structures of the D89K/D253K and D89R/D253R mutants, determined to 3.05 and 3.3?Å, respectively, showed no significant structural differences with the wild type structure despite absence of Mg²⁺ at the M1 sites. Both mutants still appear to be in the closed state. All three mutant CorA proteins exhibited transport of ⁶³Ni²⁺, indicating functionality. Thus, absence of Mg²⁺ from the M1 sites neither causes channel opening nor prevents function. We also provide evidence that the T. maritima CorA is a Mg²⁺ channel and not a Co²⁺ channel.     

An experimental study of mitosis

A comparison of colchicine-treated and normal root tips of onion provides information on the role of the spindle in mitosis, and clearly indicates the value of colchicine in the analysis of karyotypes. An improved Feulgen-squash technique is recommended, with which high quality preparations of chromosomes can be obtained as a matter of routine. This cytological exercise requires little equipment and is suitable for undergraduate courses and advanced classes in schools.     

Potassium and magnesium relationship in cowpea (Vigna unguiculata (L.) Walp.)

Summary The effects of K and Mg application on dry matter yield and uptake of K, Mg and Ca in cowpea were studied in greenhouse at Haryana Agricultural University, Hissar (india). Dry matter yields of leaves, stems and roots increased by 17, 30 and 27 per cent over control due to application of 150 ppm K and 17, 16 and 26 per cent by 40 ppm Mg respectively. Potassium application has antagonistic effect on Ca concentration of leaves, stems and roots and synergistic on root Mg concentrations upto 25 ppm K. However, Mg had a synergistic effect on concentration of K upto 20 ppm Mg and antagonistic at 40 ppm Mg in all plant parts. Uptake of K, Mg and Ca increased by Mg application, but K increased only K uptake.     

An experimental study of the effects of spider venom on animals

The effects of venom of spiders from the families Pisauridae, Argyronetidae, and Araneidae on different animals (worms, mollusks, arthropods, fishes, and mammals) were studied. The animals of different classes varied in their sensitivity to spider venom. The animals that can be a potential prey were the most sensitive. The venom of spider females was more efficient than that of males. The spiders were found to be able to kill five victims in sequence; the most effective action of venom was on the first two ones. The venom regenerates in 1.5–2.0 hours.