Rab13 is upregulated during osteoclast differentiation and associates with small vesicles revealing polarized distribution in resorbing cells

Osteoclasts are bone-resorbing multinucleated cells that undergo drastic changes in their polarization due to heavy vesicular trafficking during the resorption cycle. These events require the precise orchestration of membrane traffic in order to maintain the unique characteristics of the different membrane domains in osteoclasts. Rab proteins are small GTPases involved in regulation of most, if not all, steps of vesicle trafficking. The investigators studied RAB genes in human osteoclasts and found that at least 26 RABs were expressed in osteoclasts. Out of these, RAB13 gene expression was highly upregulated during differentiation of human peripheral blood monocytic cells into osteoclasts. To study its possible function in osteoclasts, the investigators performed immunolocalization studies for Rab13 and various known markers of osteoclast vesicular trafficking. Rab13 localized to small vesicular structures at the superior parts of the osteoclast between the trans-Golgi network and basolateral membrane domain. Rab13 localization suggests that it is not involved in endocytosis or transcytosis of bone degradation products. In addition, Rab13 did not associate with early endosomes or recycling endosomes labeled with EEA1 or TRITC-conjugated transferrin, respectively. Its involvement in glucose transporter traffic was excluded as well. It is suggested that Rab13 is associated with a putative secretory function in osteoclasts.     

Passive Detection of Biological Aerosols in the Atmosphere with a Fourier Transform Instrument (FTIR)—the Results of the Measurements in the Laboratory and in the Field

Fourier Transform Infrared Radiation (FTIR) spectroscopy is one of the most powerful methods for the detection of gaseous constituents, aerosols, and dust in planetary atmospheres. Infrared spectroscopy plays an important role in searching for biomarkers, organics and biological substances in the Universe. The possibility of detection and identifications with FTIR spectrometer of bio-aerosol spores (Bacillus atrophaeus var. globigii=BG) in the atmosphere is discussed in this paper. We describe the results of initial spectral measurements performed in the laboratory and in the field. The purpose of these experiments was to detect and to identify bio-aerosol spores in two conditions: 1) In a closed chamber where the thermal contrast between the background and aerosols was large, and 2) In open air where the thermal contrast between the background and aerosols was small. The extinction spectrum of BG spores was deduced by comparing our measurements with models, and other measurements known from the literature. Our theoretical and experimental studies indicate that, during passive remote sensing measurements, it is difficult-but possible to detect and to identify bio-aerosol clouds by their spectral signatures. The simple spectral analysis described in the paper can be useful for the detection of various kinds of trace aerosols-not only in the Earth's atmosphere, but also during planetary missions in the environments of other astronomical objects such as planets, comets etc. We expect that the interpretation of data from spectrometric sounding of Venus and Mars during the current missions Mars and Venus Express, and later during the Rosetta mission will benefit from our experimental work and numerical modelling.     

体外化学修饰红细胞--通用型血?

目前国内外对通用型血的研究主要是改造修饰红细胞表面抗原。研制的方法有两种：体外酶解修饰人A、B抗原制备O型血和使用化学材料甲氧基聚乙二醇(mPEG)共价结合到红细胞表面,遮蔽血型抗原。两种修饰的结果均表明对红细胞的结构、功能无影响。这两种修饰方法为制备通用型血供临床输血开拓了崭新的途径,具有重要意义。     

锂盐的作用机制及临床应用研究进展

锂是人体内的一种微量元素且以化合物的形式广泛存在于自然界。作为一种古老的治疗精神疾病方面的药物,锂盐被用来治疗双相情感障碍已超过60年,而现在锂盐在临床上表现出来的新应用已经越来越引起医学界的广泛重视。现代研究表明,锂盐是一种强大的糖原合成酶激酶-3(GSK-3β)抑制剂,锂盐除对脑细胞过度活动起抑制作用外,还具有营养神经和保护神经、抗炎、抗氧化、抗癌、免疫调节以及对甲状腺功能亢进的治疗作用。锂盐化学结构相对简单,而且目前人们对锂盐的使用经验及对锂离子的血药浓度监测手段已日趋成熟,所以锂盐具有相当好的临床应用前景,未来更进一步加大对锂盐的临床应用及作用机制的研究力度。现就锂盐新发现的作用机制及临床应用作一综述。     

持续农业的理论基础──农业生态系统原理

持续农业的理论基础农业生态系统原理陈欣章熙谷李萍萍（南京农业大学农学系,２１００９５）ＡＢａｓｉｓｆｏｒＳｕｓｔａｉｎａｂｌｅＡｇｒｉｃｕｌｔｕｒｅＴｈｅＰｒｉｎｃｉｐｌｅｏｆＡｇｒｏｅｃｏｓｙｓｔｅｍ．ＣｈｅｎＸｉｎ,ＺｈａｎｇＸｉｇｕ,ＬｉＰｉｎ...     

珠江口水体的光学特征及分析

通过2003年1月份对珠江口水体中的光谱分布,衰减系数,光反射率以及浮游植物对光吸收的研究结果显示:红光、蓝光衰减较快,绿光衰减较小,越向水体下层,绿光的相对含量越大,这主要是由于浮游植物在蓝光和红光波段处有吸收峰以及非藻颗粒对蓝紫光吸收较多的缘故;从总体来讲,绿光的辐亮度漫反射率(Lu/Ed)较蓝光和红光大:在上层水体中有一个反射强度较大的区域,可能是由于浮游植物在这一层的分布较多。     

锶-89在模拟水稻田中的动力学行为

采用模拟污染物的同位素示踪技术探索了89Sr在水稻－田水－土壤系统中的消长与分配,并建立了其行为规律的数学模型,结果表明,田表水中89Sr-Sr含量迅速地降低,1d后由原始量的8．5ug/g降为4．0ug/g,以后逐渐降低,至试验结束（28d)时为0．7ug/g,表土中89Sr-Sr含量声速地增大,1d后即由0达12．4ug/g,试验结束时为20．9ug/g,水稻地上部,1d后由0[达8．8ug/g,以后也呈增加趋势,结束时达21．7ug/g,水稻根由1d的9．5ug/g达试试验结束时的39．6ug/g,田表水,表土及不稻植株中89Sr-Sr含量随时间变化的规律相应为：CW＝0.965e^-0.028t 7.635e^-0.470t,C=35.142(e^-0.028t-e^-0.470t),Cz=35.182-23.481e^-0.028t-11.701e^-0.470t。其次,在收获期,糙米中89Sr-Sr含量为1．6ug/g,稻壳为9．4ug/g,稻草为39．7ug/g,稻根为41．8ug/g,还测定了89Sr-Sr在收获期土壤中的铅垂 分布,表明,58．2％的89Sr-Sr滞留于表层2cm,并且其滞留量随土壤深度按指数规律衰减：C＝20.356e^-0.467x(r=-0.9433)。     

论莺歌海盐场是大量培养螺旋藻的理想基地

根据螺旋藻自然生长的原产地的气候特点;通过对海南省莺歌海盐场的生态环境的测试,论证了莺歌海场是大量培养螺旋藻的理想基地。     

微藻生物柴油的现状与进展

微藻生物柴油能够解决目前使用植物原料发展生物柴油面临的耕地不足、气候变化对产量影响大和引起农作物价格上涨等突出问题。通过转基因技术培育“工程微藻”,繁衍能力高,生长周期短,比陆生植物产油高出几十倍,并且能用海水作为其天然培养基进行工业化生产。介绍了微藻生物柴油的优势,高脂质微藻选育,以及工程微藻研究与下游生产工艺的研究现状和进展。     

高频超声探查甲状腺结节内钙化的临床价值

目的：探讨甲状腺钙化在诊断和鉴别诊断甲状腺姑节中的临床意义。方法：回顾性分析经超声检查和手术病理证实的77例甲状腺结节患者的临床资料。结果：超声检查与病理对照分析显示：良性20例,结节性甲状腺肿18例,恶性56例,其中乳头状癌50例,乳头状增生1例。良性结节中超声声像图钙化多表现为均匀强回声光斑,光团或弧形光团,后方伴声影。恶性结节中钙化表现为“针尖样”、“砂粒样”、“点状”的微钙化,后方声影可有可无。结论：依据甲状腺结节内钙化的形态大小,可以鉴别甲状腺结节的良恶性。