世居及移居高原青少年最大有氧能力的特征

本文报道海拔３４１７ｍ和４２８０ｍ地区世居藏族和移居汉族青少年运动状态下心肺功能的对比研究。结果显示：３４１７ｍ和４２８０ｍ世居藏族的最大氧耗量、无氧阈值及最大心输出量都明显大于汉族,血氧饱和度（Ｓａｏ２）随运动负荷的增加而降低。海拔３４１７ｍ藏、汉族的△Ｓａｏ２分别为７．４６％和１０．０３％,４２８０ｍ处为８．５７％和１３．７５％,最大心率随海拔升高而下降。研究提示,藏族青少年有较高的最大有氧能力,反映了他们对低氧环境的适应优势。     

Evaluation of the weed flora of Egypt from Predynastic to Graeco-Roman times

Macrofossils of weeds retrieved from archaeological sediments in Egypt are discussed in terms of their presence, preservation and representation significance. The study reveals 112 field weeds from 61 archaeological sites dating from Predynastic times (4500 B.C.) up to the Graeco-Roman period (A.D. 395). Most of the remains were preserved by desiccation. The 112 listed species include 24 taxa from Predynastic Hierakonpolis (3800–3500 B.C.) identified for the first time. This study is based on a selection of 97 species from the entire list. Interpretation of field weed finds from the archaeological contexts is discussed. The highest number of species, 63, is recorded from the Pharaonic period. The Predynastic era is represented by 46 species and the Graeco-Roman period by 34. The intensive archaeological excavation of Pharaonic settlements may explain the rich flora of that period compared with the two others. Floristic analysis shows that 57 species were introduced in association with crops from the Middle East and 40 may belong to the native vegetation of the Nile valley.     

The phylogeny of the ant tribe Formicini (Hymenoptera: Formicidae) with the description of a new genus

Abstract. The holarctic ant tribe Formicini is revised, the new genus Bajcaridris described, and possible phylogenetic relationships are discussed. The subgenus Iberoformica is synonymized with Formica. A synopsis, diagnosis and keys to the genera are provided.     

Treatment of raw and ozonated oil sands process-affected water under decoupled denitrifying anoxic and nitrifying aerobic conditions: a comparative study

Batch experiments were performed to evaluate biodegradation of raw and ozonated oil sands process-affected water (OSPW) under denitrifying anoxic and nitrifying aerobic conditions for 33 days. The results showed both the anoxic and aerobic conditions are effective in degrading OSPW classical and oxidized naphthenic acids (NAs) with the aerobic conditions demonstrating higher removal efficiency. The reactors under nitrifying aerobic condition reduced the total classical NAs of raw OSPW by 69.1 %, with better efficiency for species of higher hydrophobicity. Compared with conventional aerobic reactor, nitrifying aerobic condition substantially shortened the NA degradation half-life to 16 days. The mild-dose ozonation remarkably accelerated the subsequent aerobic biodegradation of classical NAs within the first 14 days, especially for those with long carbon chains. Moreover, the ozone pretreatment enhanced the biological removal of OSPW classical NAs by leaving a considerably lower final residual concentration of 10.4 mg/L under anoxic conditions, and 5.7 mg/L under aerobic conditions. The combination of ozonation and nitrifying aerobic biodegradation removed total classical NAs by 76.5 % and total oxy-NAs (O3–O6) by 23.6 %. 454 Pyrosequencing revealed that microbial species capable of degrading recalcitrant hydrocarbons were dominant in all reactors. The most abundant genus in the raw and ozonated anoxic reactors was Thauera (~56 % in the raw OSPW anoxic reactor, and ~65 % in the ozonated OSPW anoxic reactor); whereas Rhodanobacter (~40 %) and Pseudomonas (~40 %) dominated the raw and ozonated aerobic reactors, respectively. Therefore, the combination of mild-dose ozone pretreatment and subsequent biological process could be a competent choice for OSPW treatment.     

Potential therapeutic effects of induced pluripotent stem cells on induced salivary gland cancer in experimental rats

Salivary gland neoplasms exhibit complex histopathology in a variety of tumor types and treatment options depend largely on the stage of the cancer. Induced pluripotent stem cells (iPS) have been investigated for treating induced salivary gland cancer and for restoring salivary gland function. We investigated iPS treatment for salivary gland cancer both in vitro and in vivo. For our study in vitro, we re-programmed human skin fibroblasts to form iPS cells using a plasmid containing Oct4, Sox2, L-MYC and LIN28. For our study in vivo, we used 30 white male albino rats divided into the following groups of 10: group 1 (control): rats were injected with phosphate-buffered saline (PBS), group 2 induced squamous cell carcinoma (SCC): rat submandibular glands were injected with squamous carcinoma cells (SCC), group 3 (induced SCC/iPS): SCC treated rats treated with 5 × 106 iPS cells. Submandibular glands from rats of all groups were examined histologically and real time PCR was performed for amylase, and COX I and COX II gene expression. We confirmed that submandibular gland specimens included tumor tissue before starting treatment with iPS. iPS treated cases exhibited regeneration of salivary glands, although minor degenerative and vascularization changes remained. The acinar cells regained their proper organization, but continued to exhibit abnormal activity including hyperchromatism. iPS cells may be useful for treating salivary gland carcinomas.     

Regulation of dendritic branching and filopodia formation in hippocampal neurons by specific acylated protein motifs

Although neuronal axons and dendrites with their associated filopodia and spines exhibit a profound cell polarity, the mechanism by which they develop is largely unknown. Here, we demonstrate that specific palmitoylated protein motifs, characterized by two adjacent cysteines and nearby basic residues, are sufficient to induce filopodial extensions in heterologous cells and to increase the number of filopodia and the branching of dendrites and axons in neurons. Such motifs are present at the N-terminus of GAP-43 and the C-terminus of paralemmin, two neuronal proteins implicated in cytoskeletal organization and filopodial outgrowth. Filopodia induction is blocked by mutations of the palmitoylated sites or by treatment with 2-bromopalmitate, an agent that inhibits protein palmitoylation. Moreover, overexpression of a constitutively active form of ARF6, a GTPase that regulates membrane cycling and dendritic branching reversed the effects of the acylated protein motifs. Filopodia induction by the specific palmitoylated motifs was also reduced upon overexpression of a dominant negative form of the GTPase cdc42. These results demonstrate that select dually lipidated protein motifs trigger changes in the development and growth of neuronal processes.     

Nomega-nitro-L-arginine methylester ameliorates myocardial toxicity induced by doxorubicin

The effects of Nomega-nitro-L-arginine methylester (L-NAME) and L-arginine on cardiotoxicity that is induced by doxorubicin (Dox) were investigated. A single dose of Dox 15 mg/kg i.p. induced cardiotoxicity, manifested biochemically by a significant elevation of serum creatine phosphokinase (CPK) activity [EC 2.7.3.2]. Moreover, cardiotoxicity was further confirmed by a significant increase in lipid peroxides, measured as malon-di-aldehyde (MDA) in cardiac tissue homogenates. The administration of L-NAME 4 mg/kg/d p.o. in drinking water 5 days before and 3 days after the Dox injection significantly ameliorated the cardiotoxic effects of Dox, judged by the improvement in both serum CPK activity and lipid peroxides in the cardiac tissue homogenates. On the other hand, the administration of L-arginine 70 mg/kg/d p.o. did not protect the cardiac tissues against the toxicity that was induced by the Dox treatment. The findings of this study suggest that L-NAME can attenuate the cardiac dysfunction that is produced by the Dox treatment via the mechanism(s), which may involve the inhibition of the nitric oxide (NO) formation. L-NAME may, therefore, be a beneficial remedy for cardiotoxicity that is induced by Dox and can then be used to improve the therapeutic index of Dox.     

Improvement of biological nitrogen fixation in Egyptian winter legumes through better management of Rhizobium

The diversity of rhizobia nodulating common bean ( Phaseolus vulgaris), berseem clover (Trifolium alexanderinum) and lentil (Lens culinaris) was assessed using several characterization techniques, including nitrogen fixation efficiency, intrinsic antibiotic-resistance patterns (IAR), plasmid profiles, serological markers and rep-PCR fingerprinting. Wide diversity among indigenous rhizobial populations of the isolates from lentil, bean and clover was found. Strikingly, a large percentage of the indigenous rhizobial population was extremely poor at fixing nitrogen. This emphasizes the need to increase the balance of highly efficient strains within the rhizobial population. Use of high-quality inocula strains that survive and compete with other less-desired and less-efficient N2-fixing rhizobia represents the best approach to increase biological nitrogen fixation of the target legume. In field-grown lentils, the inoculant strains were not able to outcompete the indigenous rhizobia and the native lentil rhizobia occupied 76–88% of the total nodules formed on inoculated plants. Nitrogen fixation by lentils, estimated using the ¹⁵N isotope dilution technique, ranged between 127 to 139 kg ha-1 in both inoculated and un-inoculated plants. With berseem clover, the inoculant strains were highly competitive against indigenous rhizobia and occupied 52–79% of all nodules. Inoculation with selected inocula improved N2 fixation by clover from 162 to 205 kg ha-1 in the three cuts as compared with 118 kg ha-1 in the un-inoculated treatment. The results also indicated the potential for improvement of N2 fixation by beans through the application of efficient N2-fixing rhizobia.