Effect of Gamma Irradiation on Volatile Compounds from Cooked Potato

The volatile compounds from cooked potato irradiated with the doses of about 10,000 and 100,000 rad were determined quantitatively immediately after irradiation and after the storage for fifty days following irradiation. In both cases, no significant differences were observed between the volatile compounds from 10,000 rad irradiated and non-irradiated potato. Irradiation of 100,000 rad resulted in increase of volatile compounds, especially that of carbonyl compounds.

The effects of gamma irradiation and storage on ascorbic acid content of potato were also studied. Ascorbic acid content of raw potato decreased approximately 10 % and 30 % than that of control by irradiation of 10,000 and 100,000 rad, respectively.     

重组人r干扰素的纯化及其N端氨基酸序列分析

本文对两个重组人γ干扰素高效表达株pIFN-γ及PBVIFN-γ的表达产物进行了纯化并对纯化的γ干扰素进行了活性鉴定及N端氨基酸序列分析。采用连续沉淀的方法对高表达菌株pBVIFN-γ及低表达菌株pIFN-γ,裂解液进行初步纯化,然后应用单克隆抗体亲和层析方法进行纯化,分别可纯化14倍与933倍,均达电泳纯,回收率分别为25％和30％,比活性达7.56×10~7U/mg蛋白。SDS-PAGE电泳上γ干扰素分子量约17.5kD。测定了纯化的γ干扰素N末端19个氨基酸序列,与由其DNA序列推导的氨基酸序列完全一致,确认了本研究所表达、纯化的γ干扰素达到了较高纯度。本方法为γ干扰素的批量生产奠定了基础。     

Effect of Penicillin on Amino Acid Fermentation

The effect of penicillin G(k) was first investigated on l-homoserine production by Micrococcus glutamicus 534-Co 147 (a threonine requiring mutant). The addition of 4 u/ml of penicillin, 7 to 9 hours after inoculation, brought about the conversion of l-homoserine to l-glutamic acid production. Similar phenomena were observed in l-lysine and l-valine fermentations. In these cases, a homoserine requiring and a leucine requiring mutant of M. glutamicus were used respectively. A marked conversion from lysine and valine to glutamate accumulation occured by penicillin addition. However, in l-isoleucine fermentation with Brevibacterium ammoniagenes ATCC 6871, no glutamate accumulation took place and isoleucine yields were remarkably decreased.     

Effects of Gamma Irradiation on Wheat Gluten

The effects of γ-irradiation on wheat gluten were studied by means of gel filtration on Sephadex G-100, starch gel electrophoresis and analysis of amino acid composition. Analyses of gluten at a moisture content of 2% revealed no significant change in amino acid composition except for cystine which was decreased by about 8% with irradiation at 10 Mrad. Changes in the chromatogram from gel filtration were interpreted in terms of random depolymerization resulting from irradiation. The results of starch gel electrophoresis suggested that irradiation levels greater than 3 Mrad resulted in characteristic changes in the molecular configuration of gliadin components.     

Effect of Gamma Irradiation on Embryogenic Avocado Cultures and Somatic Embryo Development

Embryogenic avocado cultures were exposed to ionizing irradiation in order to determine its effect on proliferation and subsequent somatic embryo development. The approximate PD₅₀ as determined by linear regression is 35 Gy 2 weeks after irradiation for Fuerte 2.11.1 and 4 weeks after irradiation for T362 2.11.1. Irradiation of embryogenic cultures did not significantly affect the number of early stage Fuerte 2.11.1 somatic embryos that developed directly from irradiated cultures; however, 10–50 Gy inhibited somatic embryo development. Irradiation of T362 2.11.1 embryogenic cultures at 25–50 Gy inhibited the number of intermediate and mature stages of somatic embryos that developed directly from irradiated cultures, and 50 Gy inhibited somatic embryo maturation. Inhibition of somatic embryo development could be partially offset by proliferation of irradiated embryogenic cultures as suspensions. Irradiation up to 10 Gy significantly increased the number of mature Fuerte 2.11.1 somatic embryos that developed from suspension cultures. Irradiation with doses up to 25 Gy stimulated development of heart stage T362 2.11.1 somatic embryos; however, mature somatic embryo development was suppressed at dosages of 10 Gy and greater.     

新型氨基酸制剂对创伤大鼠血游离氨基酸的影响

观察了富含牛磺酸 (Tau)、谷氨酰胺 (Gln)以及高支链氨基酸 (HBCAA)的新型氨基酸制剂对创伤大鼠血中游离氨基酸浓度的影响。结果表明 ,创伤后三天起 ,血浆游离氨基酸总和均显著降低 ,对照组基本无改变 ;创伤后Tau、BCAA、精氨酸以及天冬氨酸等具有抗氧化和免疫调节作用的氨基酸含量明显降低 ,新处方使用一周后其浓度有效回升 ,且效果好于 17种氨基酸 ,从而有利于机体伤口的愈合。这些结果为进一步阐明复合氨基酸制剂促进创伤愈合的作用及其开发应用提供了理论依据     

平衡型氨基酸透析液对维持性血液透析患者血浆游离氨基酸含量的影响

目的:研究一种平衡型氨基酸透析液,探讨其对维持性血透患者血游离氨基酸含量的影响。方法:实验采用自身对照设计,应用蛋白水解法测定、分析应用氨基酸透析液血透前后患者血浆氨基酸含量,并同时测定应用碳酸盐透析液患者及健康人血浆游离氨基酸作为比较。结果:经碳酸盐透析后,患者血浆大多数游离氨基酸和总氨基酸含量显著降低。给予平衡氨基酸透析液能不同程度改善患者血浆游离氨基酸的含量。结论:平衡型氨基酸透析液能减少血中部分氨基酸的丢失。     

Gamma Irradiation of Stentor polymorphus

SYNOPSIS. Stentor polymorphus was irradiated with ⁶⁰Co gamma rays at 525 rads/minute to examine the effect on survival, cell division, oral membranellar frequency and oxygen uptake. Both survival and cell division were studied on single cells. The LD₅₀ is 285 kilorads but cell division is inhibited below this dose; 110 kilorads doubles the 1st post-irradiation division interval, and a delay of 240 hours occurs at the maximum tolerated dose of 310 kilorads. Conjugating cells are more sensitive, with an LD₅₀ of approximately 40 kilorads.
The frequency of cilia in the membranellar band, measured stroboscopically, is reduced by 30% after 14.5 kilorads, and stopped by higher doses. Recovery has a similar time scale to recovery of fission. A Clarke electrode was used to measure changes in oxygen uptake after irradiation. Depressions of up to 50% were found. Recovery followed a similar pattern to that of ciliary activity and cell division.     

Amino Acid Formation in Gas Mixtures by High Energy Particle Irradiation

Amino acids were formed from carbon monoxide, nitrogen and water, which are possible constituents of the primitive earth's atmosphere, by irradiation with high energy particles (components of cosmic rays). Glycine yield was proportional to the total energy deposited to the gas mixture, and its G-value was as high as 0.02 when the carbon monoxide/nitrogen ratio was 1. Based on an estimate of the effective energies of various types of energy sources available in the primitive earth's atmosphere for amino acid synthesis, it is suggested that cosmic rays were one of the most important energy sources for the synthesis of amino acids on the primitive earth.     

Effect of Steam Sterilization and Gamma Irradiation of Peat on Quality of Rhizobium Inoculants

Data obtained by independent tests on each of 483 batches of Rhizobium inoculants for Glycine max, Medicago sativa, and Arachis hypogaea, manufactured commercially in South Africa, are reported and discussed. Whereas the average cell count per gram per batch was well in excess of 10⁹, inoculants for G. max and M. sativa manufactured with peat treated with gamma irradiation at a dose of 50 kGr contained significantly higher numbers of Rhizobium cells than inoculants from peat which received 25 kGr. Inoculants for M. sativa manufactured with steam-sterilized peat were similar in quality to those prepared with peat irradiated at a dose of 50 kGr. Contrary to the inoculants for G. max and M. sativa, the Rhizobium strain used in inoculants for A. hypogaea was apparently insensitive to the effect on peat of the higher gamma irradiation dosage.     

Solid Phase and Solution Phase Synthesis of Gamma Amino Acid Homo-Oligomers and Mixed Oligomers

Abstract  

An efficient stepwise synthesis of homo-oligomers and mixed oligomers of gabapentin and pregabalin on solid support using Fmoc-protected derivatives and HBTU/HOBt/DIEA as coupling agent is described. The synthesis was also carried out using solution phase methodology. The Gpn/Pgn homo oligomers and mixed oligomers forms C₉ helix in solution as determined by NMR study. Chiral as well as achiral gamma amino acids were used for the synthesis of oligomers in order to investigate the secondary structural preferences.     

Control of Continuous Irradiation Injury on Potatoes with Daily Temperature Cycling

Two controlled-environment experiments were conducted to determine the effects of temperature fluctuations under continuous irradiation on growth and tuberization of two potato (Solanum tuberosum L.) cultivars, Kennebec and Superior. These cultivars had exhibited chlorotic and stunted growth under continuous irradiation and constant temperatures. The plants were grown for 4 weeks in the first experiment and for 6 weeks in the second experiment. Each experiment was conducted under continuous irradiation of 400 micromoles per square meter per second of photosynthetic photon flux and included two temperature treatments: constant 18°C and fluctuating 22°C/14°C on a 12-hour cycle. A common vapor pressure deficit of 0.62 kilopascal was maintained at all temperatures. Plants under constant 18°C were stunted and had chlorotic and abscised leaves and essentially no tuber formation. Plants grown under the fluctuating temperature treatment developed normally, were developing tubers, and had a fivefold or greater total dry weight as compared with those under the constant temperature. These results suggest that a thermoperiod can allow normal plant growth and tuberization in potato cultivars that are unable to develop effectively under continuous irradiation.     

基于氨基酸分类的基本氨基酸秩序的研究

在分析了基本氛基酸分类的基础上,提出基本氛基酸存在着一种参考排列秩序,以此固定的氛基酸排列秩序为参考标准,分析蛋白质一级结构相对此参考秩序的变化规律,能够找到构成蛋白质的二级结构的某些信息．