-蒎烯合成2-羟基-3-蒎酮的研究

研究了高锰酸钾氧化α-蒎烯合成2-羟基-3-蒎酮的工艺条件,对助溶剂等影响因素进行了探讨,较优工艺条件为:以叔丁醇为助溶剂,不改变pH值,温度0-5℃,KMnO4与α-蒎烯的物质的量比为1.7:1～1.8:1,先加α-蒎烯后加KMnO4.所得2-羟基-3-蒎酮采用IR、MS、1H NMR、3C NMR进行了表征,产率达60%,与文献相同,助溶剂改用叔丁醇后回收率＞90%,高于原用助溶剂丙酮(回收率70%).     

Expression of natural killer cell stimulatory receptor NKG2D and its ligand MICA in Tibetan patients with gastric cancer at Qinghai plateau

AIM: To investigate the expression of natural killer cell stimulation receptor D(NKG2D) in peripheral blood and the expression of major histocompatibility complex class I chain-related protein A(MICA) on the gastric carcinoma tissue and the neighboring non-cancerous tissue in Tibetan patients with gastric cancer at Qinghai plateau. METHODS: Samples of 33 patients and 20 healthy persons were collected to detect NKG2D in peripheral blood by Flow cytometry analysis. The expressions of MICA in part of the correspondent tissues were examined by RT-PCR and immunohistochemistry.RESULTS: The expression of NKG2D in the plateau of Tibetan patients with gastric cancer group (13.47 ±5.26)% was significantly lower than that in healthy groups (32.62±10.08)%. The mRNA level of MICA in gastric cancer was significantly higher than that in neighboring non-cancerous tissue (P<0.05). The expressions of MICA proteins showed a significant difference between the neighboring non-cancerous tissue (21.21%, 7/33) and the gastric carcinoma tissue (78.79%, 26/33), between the high differentiation (60.00%, 3/5) and the moderate (72.73%, 8/11), low differentiation (88.24%, 15/17). The expressions of MICA were not correlated with tumor size, sex, age, lymph node metastasis of the patients (P>0.05). Spearman rank correlation displayed that the expressions of MICA mRNA were positively correlated with the MICA protein level (r=0.903, P<0.01).CONCLUSION: The immune escape in Tibetan patients with gastric cancer at Qinghai plateau probably relates to the down-regulation of NKG2D and the up-regulation of its ligand MICA. The activity of NK cells and the anti-cancer cellular immunity level are descending in the plateau of Tibetan patients with gastric cancer. The decrease in the receptor NKG2D is a reason for the activity of NK cell descending.     

槟榔江水牛OXCT1基因的分子特征及组织表达谱分析

本研究对槟榔江水牛3-酮酸辅酶A转移酶1（3-oxoacid CoA-transferase 1,OXCT1）基因的完整CDS区进行了PCR扩增,并对其功能生物信息学和多组织差异表达进行了分析。以普通牛OXCT1基因序列（GenBank登录号：XM_006076397）为参考序列,采用Primer Premier 5.0软件设计引物序列,以提取的槟榔江水牛基因组DNA为模板,PCR扩增获得槟榔江水牛OXCT1基因mRNA序列,扩增产物经测序后利用ORF Finder软件进行开放阅读框识别,获得水牛OXCT1基因CDS区全序列,并对其进行生物信息学分析。结果显示,槟榔江水牛OXCT1基因CDS序列全长1 563 bp,编码520个氨基酸,蛋白分子式为C₂₅₀₉H₄₀₄₁N₆₈₇O₇₄₆S₂₃,分子质量为56.50 ku,理论等电点（pI）为8.69,不稳定系数为27.49,平均疏水性（GRAVY）为-0.097,该蛋白属弱亲水性蛋白。OXCT1蛋白无信号肽和跨膜结构,属于线粒体膜蛋白;包含pcaJ_scoB_fam和AtoD 2个保守结构域,且具有5个功能活性位点。槟榔江水牛与普通牛、藏羚羊等5个物种的OXCT1氨基酸序列同源性≥ 97%。对槟榔江水牛13个组织进行表达谱分析表明,在泌乳期,OXCT1基因在乳腺中表达量最高,在肾脏、垂体、脂肪、大脑、皮肤和肌肉中不表达;在非泌乳期,OXCT1基因在除脂肪以外的其他12个组织中都有表达。OXCT1基因在槟榔江水牛泌乳期乳腺组织中表达量最高,推测其可能参与了水牛的乳脂合成调控事件。本研究结果可为深入了解乳脂合成代谢及其调控机制提供依据。     

鸡公山自然保护区芳香植物资源调查研究

鸡公山自然保护区内芳香植物资源丰富,经初步调查,共计26科106种,其中裸子植物4科11种,被子植物22科95种。论述了鸡公山自然保护区芳香植物的种类、分布及精油提取部位,对其开发利用提出了建议。     

大兴区特色农业产区土壤养分评价及空间特征

基于北京大兴区耕地质量等级调查评价成果,按《土地质量地球化学评价规范》(DZ/T 0295—2016)补充采样调查测试,开展研究区特色农业产区土地质量地球化学评价.结果表明,研究区特色农业产区土壤养分综合等级主要以二等为主,面积为10266.18hm2,占特色农业产区总面积的53.67％;土壤环境质量总体优良,土地质量状况整体良好.特色农业产区土地质量地球化学评价结果可揭示特色农业产地土地质量等级以及重要土地问题,为区域特色农产品与生态农业开发等提供依据.     

玉米多胞质雄性不育杂交种冀玉988的选育及利用

不育化制种主要在于保证杂交种子的质量及降低其生产成本。多胞质杂交种的利用主要拓宽胞质异质性，增强杂交种对环境的适应能力与防范小斑病菌新的专化小种的严重为害。本研究以优良玉米新品种冀玉988（6048×黄选921．6）为背景，以s组的s，M，R与21A及C组的Rb，Bb与Es雄性不育细胞质（CMS）为试材，将母本6048转育成同核异质体，不育性稳定。父本921．6对21A，s与R三种CMS具有强恢复性。本研究论证了多胞质杂交种在生产上利用的可行性。冀玉988已配制成具有恢复性能的多胞质雄性不育杂交种，可用于生产。     

Gluten Structural Evolution During Pasta Processing of Refined and Whole Wheat Pasta from Hard White Winter Wheat: The Influence of Mixing,Drying, and Cooking

An attempt was made to evaluate gluten structural changes in refined and whole wheat pasta from hard white winter wheat to elucidate the impact of whole wheat components on the formation and structure of the gluten network in pasta. Attenuated total reflectance–FTIR spectroscopy was used to track gluten secondary structure through most of the major steps in pasta processing: raw material, mixing, drying, and cooking. Protein solubility, accessible thiols, and SDS‐PAGE data were also collected to provide additional information on the nature of protein interactions and network composition. Few secondary structural differences were observed between refined and whole wheat flours from hard white wheat. However, mixing induced a significant shift to β‐sheet structures in refined dough that was not equally matched by whole wheat dough. Drying under both high temperature, short time (HT) and low temperature, long time (LT) conditions resulted in a reversion to structural distributions similar to those for flour in both pastas. However, greater protein denaturation in HT samples was indicated by lower protein solubility also in the presence of denaturants and disulfide reducing agents. Cooking generated a substantial increase in β‐sheet structures for both pasta systems. This structure was greatest in refined and LT samples. Thiol accessibility data indicate the presence of a highly aggregated, compact gluten network in refined pasta, mostly driven by hydrophobic association. Conversely, the network in whole wheat pasta was more loosely associated and dependent on disulfide bonding, both of which fit well with the secondary structural data.     

Long-term consequences of topsoil mining on select biological and physical characteristics of two New Zealand loessial soils under grazed pasture

Soil chemical, biochemical, biological and structural properties were measured in two New Zealand loessial soils that were topsoil-mined 10 and 25 years ago respectively. Measurements at the 10-year site were compared to some earlier measurements made at this site and the data combined in a chronological sequence for analysis. Topsoil mining had a large, detrimental impact on the soil microbial biomass, the earthworm populations, easily mineralizable N and soil enzyme activities. However, most of these properties substantially recovered, to 80-90 per cent of the levels in unmined soils, within 10-25 years of restoration under pasture. In contrast, while total soil C and N were less affected by topsoil mining, their recovery was much slower. Stabilities of macro-aggregates of soil had fully recovered within 10-25 years after topsoil mining. The apparent changes in all the measured properties between 10 and 25 years of restoration were small in comparison with changes between 0-10 years of restoration after topsoil mining. The total C content of both soils under pasture appeared unlikely to attain the levels present in unmined soils. In soils undergoing restoration, the ratio of microbial C/total soil C may be a useful index of soil ‘biological stability’. Sulphatase activity may reflect the recovery of pasture production.