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Search Results: 1 - 10 of 50942 matches for " Zengquan Wei "
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Molecule modification and mass deposition induced by the implantation of low energy Fe+ ion beams into amino acids
Shibin Yuan,Zengquan Wei,Qingxiang Gao
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9153
Abstract: Fe+ ion beams with the energy of 110 keV were implanted into films of L(+)-cysteine (HSCH2CH(NH2)COOH). One of the single crystals grown in hydrochloric acid solution with the implanted samples through slow evaporation was structurally characterized by the X-ray crystallography. The crystal is monoclinic, space group C2, with a = 1.8534(4) nm, b = 0.5234(1) nm, c = 0.7212(1) nm, β= 103.72°, V = 0.67965(3) nm3, Z = 4, F(000) = 144.0, D{clac} = 1.763 g · cm 3, μ(MoK a = 1.06 mm 1, T = 293(2) K. R = 0.0379, wR = 0.0835 for 660 observed reflections (I > 2σ(I)). The structural formula of the crystal compound is (CH2CH(NH2)NO2)ClFe (M r = 180.38 u). Products of heavy ion beam irradiation were purified and it was directly confirmed that the implanted Fe+ ions had been deposited in the novel molecules. The same doses of Fe+ ion beams of the same energy were implanted into films of L(+)-cysteine hydrochloride monohydrate. FTIR spectroscopy of the implanted samples proved that some of the original molecules were seriously damaged and significant modifications were induced.
Calculation of depth-dose distribution of intermediate energy heavy-ion beams
Qiang Li,Zengquan Wei,Wenjian Li
Chinese Science Bulletin , 2002, DOI: 10.1007/BF03183312
Abstract: Based on the characteristics of the interactions between intermediate energy heavy-ion beam and target matter, a method to calculate the depth-dose distribution of heavy-ion beams with intermediate energy (10 –100 MeV/u) is presented. By comparing high energy beams where projectile fragmentation is overwhelming with low energies where energy straggling is the sole factor instead, a crescent energy spread with increasing depth and a simple fragmentation assumption were included for the depth-dose calculation of the intermediate energy beam. Relative depth-dose curves of carbon and oxygen ion beams with intermediate energies were computed according to the method here. Comparisons between the calculated relative doses and measurements are shown. The calculated Bragg curves, especially the upstream and downstream Bragg peaks, agree with the measured data. Differences between the two results appear only around the peak regions because of the limitations of the calculation and experimental conditions, but the calculated curves generally reproduce the measured data within the experimental errors. The reasons for the divergences were analyzed carefully and the magnitudes of the deviations are given.
Molecule modification and mass deposition induced by the implantation of low energy Fe+ ion beams into amino acids

YUAN Shibin,WEI Zengquan,GAO Qingxiang,

科学通报(英文版) , 2002,
Abstract: Fe+ ion beams with the energy of 110 keV were implanted into films of L(+)-cysteine (HSCH2CH(NH2)COOH). One of the single crystals grown in hydrochloric acid solution with the implanted samples through slow evaporation was structurally characterized by the X-ray crystallography. The crystal is monoclinic, space group C2, with a = 1.8534(4) nm, b = 0.5234(1) nm, c = 0.7212(1) nm, β= 103.72°, V = 0.67965(3) nm3, Z = 4, F(000) = 144.0, D{clac} = 1.763 g · cm 3, μ(MoK a = 1.06 mm 1, T = 293(2) K. R = 0.0379, wR = 0.0835 for 660 observed reflections (I > 2σ(I)). The structural formula of the crystal compound is (CH2CH(NH2)NO2)ClFe (M r = 180.38 u). Products of heavy ion beam irradiation were purified and it was directly confirmed that the implanted Fe+ ions had been deposited in the novel molecules. The same doses of Fe+ ion beams of the same energy were implanted into films of L(+)-cysteine hydrochloride monohydrate. FTIR spectroscopy of the implanted samples proved that some of the original molecules were seriously damaged and significant modifications were induced.
INACTIVATION AND MUTATION OF YEAST CELLS INDUCED BY HEAVY ION BEAM
重离子束对酵母细胞的失活与突变

Wei Zengquan,
卫增泉
,H.-D. Pross,U. Weidmann,J. Kiefer

生物物理学报 , 1995,
Abstract: 双倍体酵母细胞D7经单核能为11.4MeV/u的An和U离子辐照后,测定了细胞随剂量的存活率和突变率。获得细胞对Au和U离子的失活截面分别为2.54μm2和1.92μm2。在存活率为37%的条件下,Au、U离子的RBE分别为0.28和0.19。在突变实验中,研究了DNA断链后的重组与倒位,它们对Au和U离子的截面为:8.3×10-2μm2[σm-rec(Au)],9.5×10-5μm2[σm-rec(U)]和6.1×10-4μm2[σm-rev(Au)]和3.8×10-5μm2[σm-rev(U)].最后,对所获结果进行了讨论。
Synthesis, in Vitro Antimycobacterial and Antibacterial Evaluation of IMB-070593 Derivatives Containing a Substituted Benzyloxime Moiety
Zengquan Wei,Jian Wang,Mingliang Liu,Sujie Li,Lanying Sun,Huiyuan Guo,Bin Wang,Yu Lu
Molecules , 2013, DOI: 10.3390/molecules18043872
Abstract: A series of novel IMB-070593 derivatives containing a substituted benzyloxime moiety and displaying a remarkable improvement in lipophilicity were synthesized and evaluated for their in vitro antimycobacterial and antibacterial activity. Our results reveal that the target compounds 19a– m have considerable Gram-positive activity (MIC: <0.008–32 μg/mL), although they are generally less active than the reference drugs against the Gram-negative strains. In particular, compounds 19h, 19j, 19k and 19m show good activity (MICs: <0.008–4 μg/mL) against all of the tested Gram-positive strains, including ciprofloxacin (CPFX)- and/or levofloxacin (LVFX)-resistant MSSA, MRSA and MSSE. Moreover, compound 19l (MIC: 0.125 μg/mL) is found to be 2–4 fold more active than the parent IMB070593, CPFX and LVFX against M. tuberculosis H37Rv ATCC 27294.
Biological effects of radioactive 9C-ion beams on cells
Zengquan Wei,Qiang Li,A. Kitagawa,T. Kanai,M. Kanazawa,Y. Furusawa,E. Urakabe,Hongmei Xie,Guangming Zhou
Chinese Science Bulletin , 2005, DOI: 10.1360/982004-774
Abstract: The distinguishing feature and current technique progress of tumor treatment with heavy-ion beams is introduced in the paper. Additional superiority to tumor treatment from a radioactive ion beam (RIB) is emphatically discussed. The experimental research of the radioactive 9C-ion beams aimed at tumor treatment at Heavy Ion Medical Accelerator in Chiba (HIMAC), National Institute of Radiological Sciences (NIRS), Japan is described in detail, including production of the beams, optimization of parameters, distribution of depth dose, survival effect of cell and comparison of RBE between 9C- and 12C-beams. Results show that under 40 mm thick Beryllium target and 10 mm thick aluminum degrader at full (5%) momentum acceptance, the production rate and purity of the produced 9C-beams are 9.07×l06 and 82.88% respectively with the primary 12Cbeams of 430 MeV/u and 1.8×l09 pps. A uniform irradiation field with homogeneity up to 89.6% inside central area 10 mm in diameter is obtained by using spot scanning. In this case, the dose rate at the entrance is 0.5 Gy/h. In survival experiment of cells, the average relative biological effectiveness (RBE) of 9C-beams is 5.28 and 2.93 for 12C-beams in the region around Bragg peak. The RBE of 9C-beams is 1.8 times higher than that of 12C-beams. It indicates that cell-killing efficiency of 9C-beams is stronger than that of {u12}C-beams. 9C-beams are more efficacious for tumor treatment than 12C-beams.
AN IMPORTANT MECHANISM OF CROP BREEDING WITH ULTRALOW ENERGY ION INJECTION
超低能离子注入作物育种的一种重要机制

Wei Zengquan,Han Guangwu,Zhou Guangming,Li Qiang,Xie Hongmei,
卫增泉
,韩光武,周光明,李强,颉红梅,高清祥

生物物理学报 , 1996,
Abstract: 本文通过超低能(110keV)离子注入和同步辐射碳光辐照两种手段处理了小麦种子,经萌发在其根尖细胞中均观察到了多种类型的染色体时变,而且同对照相比,均有明显的微核率与染色体总畸变率。根据理论分析和一些有关的实验证据,超低能离子注入小麦种子,因离子本身射程非常短(<1μm),不可能直接损伤麦皮下面的胚细胞,而由注入离子在作物种子内产生的各种特征X-射线,只要剂量足够,却能达到较深的部位,通过它们的间接作用就会损伤胚细胞造成生物学效应。因此,赵低能离子注入作物种子激发产生的特征X-射线是其诱变育种的一种重要机制.
Analysis of Products of Thymine Irradiated by Heavy Ion Beam with Capillary Gas Chromatography
重离子辐照胸腺嘧啶产物的毛细管气相色谱分析

Cai Xichen,Wei Zengquan,Li Wenjian,Liang Jianping,Li Qiang,
蔡喜臣
,卫增泉,李文建,梁剑平,李强

色谱 , 1999,
Abstract: In this study some chromatographic methods with capillary column, such as GC, GC-MS, GC-FTIR, were used to analyze the products of thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution. Because of the complexity and small amounts of the products after irradiation by heavy ion beams, it is very difficult to separate them, while with the methods of capillary gas chromatography this problem can be overcome. From the results of GC-MS analysis we can determine the molecular weight of the product, and from the results of GC-FTIR analysis we can get structure information of the product. By this way the products such as 5,6-dihydrothymine, 5-hydroxyl-5-methylhydantoin, 5-hydroxyl-6-hydrothymine, 5-hydro-6-hydroxylthymine, 5-hydroxymethyluracil, trans-thymine glycol, cis-thymine glycol and dimers were determined. Though these products are the same as those from thymine irradiated by gamma ray in N2O saturated aqueous solution, the mechanism of heavy ion beam interact ion with thymine aqueous solution is different from that of gamma ray. The main products from thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution are formed by hydroxyl additions between 5-6 band of thymine, while those by gamma ray are dimers of thymine.
Recording of calcium transient and analysis of calcium removal mechanisms in cardiac myocytes from rats and ground squirrels
Shiqiang Wang,Zengquan Zhou,Hong Qian
Science China Life Sciences , 2000, DOI: 10.1007/BF02879128
Abstract: With confocal microscopy, we recorded calcium transients and analyzed calcium removal rate at different temperatures in cardiac myocytes from the rat, a non-hibernator, and the ground squirrel, a hibernator. The results showed a remarkable increase of the diastolic level of calcium transients in the rat but no detectable change in the ground squirrel. Calcium transient of the ground squirrel, compared with that of the rat at the same temperature, had a shorter duration and showed a faster calcium removal. As indicated by the pharmacological effect of cyclopiazonic acid, calcium uptake by sarcoplasmic reticulum (SR) was the major mechanism of calcium removal, and was faster in the ground squirrel than in the rat. Our results confirmed the essential role of SR in hypothermia-tolerant adaptation, and negated the importance of Na-Ca exchange. We postulated the possibility to improve hypothermia-tolerance of the cardiac tissue of non-hibernating mammals.
Temperature dependence of intracellular free calcium in cardiac myocytes from rat and ground squirrel measured by confocal microscopy
Shiqiang Wang,Zengquan Zhou,Hong Qian
Science China Life Sciences , 1999, DOI: 10.1007/BF03183606
Abstract: The temperature-dependence of intracellular free calcium ([Ca2+]i) was investigated in indo-1 loaded ventricular myocytes from the rat, a non-hibernator, and from the ground squirrel, a hibernator. The dissociation constant of indo-1 at different temperatures was calibrated both at pH-stat and at α-stat, and the result demonstrated that the α-stat calibration should be preferred. Analysis of the fluorescent image showed a striking increase of [Ca2+]i as well as spontaneous calcium waves in rat cells, indicating an overloaded calcium. In contrast, cardiac myocytes of the ground squirrel were found to keep a constant [Ca2+]i without calcium overload regardless of temperature variation. It is believed that understanding of the mechanisms underlying the intercellular calcium homeostasis of hibemators may lead to solutions of some medical questions.
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