吊兰染色体核型分析

对吊兰体细胞染色体计数,并进行核型分析。结果表明,吊兰染色体数目为2n=28;核型公式为2n=2x=28=4m+14sm+10st;染色体相对长度组成为2n=28=4L+14M2+10M1,属于3B型;全组染色体总长73.84μm,长臂总长为53.59μm;核型不对称系数为72.58%;染色体总体积为101.94μm³。     

Cerebrocellular Swelling in the Presence of Uraemic Guanidino Compounds: Ameliorative Effects of Taurine

Cell volumes (equilibrium non-inulin spaces) have been measured in slices of rat cerebral cortex incubated in the presence of uraemic guanidino compounds. Of 5 guanidino compounds tested, all but one caused significant cell swelling. This was most pronounced for guanidinosuccinic acid (GSA, 40 μmol/l)(+22%) and guanidine hydrochloride (G, 3 μmol/l)(+13%). Swelling was reduced by taurine in a dose-dependent manner, being completely abolished at 20 mmol/l. Swelling was also abolished by the antioxidants ascorbic acid (0.4 mmol/l) and butylated hydroxytoluene (0.5 mmol/l), the free radical scavenger N-acetyl-l-cysteine (10 mmol/l) and the lipid peroxidase inhibitor desmethyl tirilazad (100 μmol/l). The remission of swelling by 20 mmol/l taurine was reduced by 50% by the taurine transport inhibitor guanidinoethylsulphonate (GES, 1 mmol/l). This figure was not significantly altered when the concentration of GES was increased to 10 mmol/l. It was also reduced by 45% by the GABA_a receptor antagonist bicuculline (100 μmol/l). It was completely abolished when both GES and bicuculline were present. It is suggested that guanidino compounds result in cells undergoing oxidative-nitrosative stress, and that taurine protects against the resultant cell swelling by 2 mechanisms One (intracellular) requires taurine transport and depends on its role as an antioxidant, with lipid peroxidation being probably a significant factor. The other (extracellular) is associated with activation of GABA_a receptors. Special issue dedicated to Simo S. Oja     

Effect of proteolytic enzyme on dyeing of wool with madder

In recent years, the use of low-environmental impact biotechnology giving rises to new types of treatment in the textile industry. The use of protease enzymes to improve some physical and mechanical properties such as smoothness, drapeability, dyeing affinity and water absorbency is particularly interesting. In this research, wool yarns were first treated with different concentrations of protease enzymes in water solution including 1, 2, 4 and 6% o.w.f. for 60 min. The dyeing process was then carried out on the treated yarns with madder (50% o.w.f.). Tensile strength of treated yarns was decreased due to enzyme treatment and it continued to decrease with an increase in enzyme concentration in solution. The L^* values decreased for the samples treated with enzyme. The wash and light fastness properties of samples were measured according to ISO 105-CO5 and Daylight ISO 105-BO1. The washing fastness properties of treated samples were not changed. In the case of light fastness properties, it was increased a little for 4% and 6% enzyme treated samples.     

Morphological Measurement and Analysis of Gymnarchus Niloticus

Gymnarchus niloticus swims by undulations of a long-based dorsal fin, while its body axis is in many cases held straight during swimming. This paper provides a brief relevant introduction to Gymnarchus niloticus , which belongs to the African freshwater electric eels but can inspire our bionic interests in propulsion besides its abilities in electric sensing. A special larva of Gymnarchus niloticus was morphologically measured by photographing it with a piece of scale-calibrated paper as the background. Then we analyzed the data by a CFD-aided approach. Detailed flow patterns around the larva and a NACA0012 hydrofoil were respectively calculated and visualized at the Reynolds number of 7350 or so. The results show that the profile of Gymnarchus niloticus is well streamlined.     

Numerical analysis for determination of the presence of a tumor and estimation of its size and location in a tissue

This article deals with the numerical analysis to ascertain the presence of a tumor and to estimate its size and location in a tissue. Heat transfer in the tissue is modeled using the Pennes bioheat transfer equation, and is solved using the finite volume method. Consideration is given to 1-D brain and breast tissues. Temperature distributions in the tissues are specific to the tumor grades, its locations and sizes, and these are different than that of a normal tissue. With temperature distribution known a priori, estimations of the position and the size of a tumor are done using the inverse analysis. The proposed approach gives a correct estimation of the presence of a tumor and its location and size.     

试论林网在景观中布局的宏观度量与评价

为通过对林网在景观中布局进行度量与评价而探讨在宏观上确定经营林网主要方向的依据,根据景观生态学原理,研究了适合于度量林网在景观中布局的数量、分布以及成型状况等景观指标─—林网带斑比、优势度、连接度和环度。提出了用由林网建设方案得到的林网结构参数计算林网合理景观指标值和用由调查得到的现有林网结构参数计算现有林网实际景观指标值的方法;讨论了用这两套林网景观指标值对现有林网布局进行评价,在宏观上确定经营林网主要方向的方法。最后,以对吉林省农安县前岗乡林网现状进行度量与评价为例,示范了本文研究结果的应用。     

Osmotic regulation ofmyo-inositol uptake in primary astrocyte cultures

Uptake ofmyo-inositol by astrocytes in hypertonic medium (440 mosm/kg H₂O) was increased near 3-fold after incubation for 24 hours, which continued for 72 hours, as compared with the uptake by cells cultured in isotonic medium (38 nmoles/mg protein).myo-Inositol uptake by astrocytes cultured in hypotonic medium (180 mosm/kg H₂O) for periods up to 72 hours was reduced by 74% to 8 to 10 nmoles/mg protein. Astrocytes incubated in either hypotonic or hypertonic medium for 24 hours and then placed in isotonic medium reversed the initial down- or up-regulation of uptake. Activation of chronic RVD and RVI correlates with regulation ofmyo-inositol uptake. A 30 to 40 mosm/kg H₂O deviation from physiological osmolality can influencemyo-inositol homeostasis. The intracellular content ofmyo-inositol in astrocytes in isotonic medium was 25.6 ± 1.3 g/mg protein (28 mM). This level ofmyo-inositol is sufficient for this compound to function as an osmoregulator in primary astrocytes and it is likely to contribute to the maintenance of brain volume.     

森林积雪蒸发测算方法及研究进展

森林积雪蒸发(升华)动态的准确测算是正确理解森林积雪区地表能量和水量平衡的关键问题之一,也是区域水文模型和气候模式的重要环节.本文综述了现有的森林积雪蒸发测算方法,分析了质量平衡法(包括雪水当量法、降雪和穿透降雪对比测量法、雪面蒸发器法、蒸渗仪法、单株称量法、树冠截雪称量法和γ射线减弱技术)和微气象法(包括波文比能量平衡法、彭曼联合法、空气动力学法、表面温度技术和涡度相关法)的适用性.同时对不同森林类型积雪蒸发及其影响因素的研究进展进行了详细回顾,并结合现有研究的不足对今后的森林积雪蒸发研究进行展望,以期为未来的森林积雪蒸发相关研究提供指导.     

Validation of an ambient system for the measurement of gait parameters

Fall risk in elderly people is usually assessed using clinical tests. These tests consist in a subjective evaluation of gait performed by healthcare professionals, most of the time shortly after the first fall occurrence. We propose to complement this one-time, subjective evaluation, by a more quantitative analysis of the gait pattern using a Microsoft Kinect. To evaluate the potential of the Kinect sensor for such a quantitative gait analysis, we benchmarked its performance against that of a gold-standard motion capture system, namely the OptiTrack. The “Kinect” analysis relied on a home-made algorithm specifically developed for this sensor, whereas the OptiTrack analysis relied on the “built-in” OptiTrack algorithm. We measured different gait parameters as step length, step duration, cadence, and gait speed in twenty-five subjects, and compared the results respectively provided by the Kinect and OptiTrack systems. These comparisons were performed using Bland-Altman plot (95% bias and limits of agreement), percentage error, Spearman’s correlation coefficient, concordance correlation coefficient and intra-class correlation. The agreement between the measurements made with the two motion capture systems was very high, demonstrating that associated with the right algorithm, the Kinect is a very reliable and valuable tool to analyze gait. Importantly, the measured spatio-temporal parameters varied significantly between age groups, step length and gait speed proving the most effective discriminating parameters. Kinect-monitoring and quantitative gait pattern analysis could therefore be routinely used to complete subjective clinical evaluation in order to improve fall risk assessment during rehabilitation.     

Mechanical transduction by membrane ion channels: a mini review

There are ion channels in the cell membrane that are sensitive to stress in the membrane cytoskeleton. Some channels turn on with stress, others turn off. In specialized receptors such as those involved in hearing, touch, etc. the role of the channels is clear. However, virtually all cells have these channels, and we don't yet know the physiological role of the channels although it is reasonable to suppose that they are involved in the control of cell size, either acutely as in volume regulation, or trophically as in the control of cell division.