一株耐As细杆菌对As3+的吸附特征与机理

【目的】评价细杆菌属去除水溶液中As^3+的可行性,为As污染的微生物修复提供必要的修复材料和理论依据。【方法】从湖南某矿区筛选分离等得到了一株高耐砷菌株,经过16S rRNA序列分析初步鉴定为细杆菌属Microbacterium,命名为A4,并采用单因素试验优化菌株生长条件,正交试验优化菌株菌粉吸附As^3+的条件。通过吸附动力学与等温吸附试验研究菌株菌粉对As^3+的吸附特征,并利用SEM-EDX与FTIR分析探讨了该菌株菌粉对As^3+的吸附机理。【结果】菌株A4对As^3+的耐受阈值为53 mmol/L;菌株A4的最适生长条件为温度30℃、pH值7.0~9.0、NaCl浓度0.25 m/v、转速180 r/min。正交优化试验结果表明:菌粉吸附As^3+的最佳条件为菌粉投加量为0.02 g/L、吸附时间为2 h、pH值为8.0和温度为20℃,此条件下菌粉对As^3+的吸附量为128 mg/g。Langmuir方程与准一阶动力学方程可被较好的用于描述菌粉对As^3+的等温吸附特性与动力学特性,拟合度均达0.99,菌粉对As^3+的最大吸附量达114.6 mg/g。SEM-EDX与FTIR分析表明:吸附过程中的主要功能团-COOH、-OH、-NH、-CHO和O-P-O等与As络合,以及As^3+在菌粉表面与Mg2+发生了离子交换作用,促进了菌粉对As^3+的吸附。【结论】可为未来水体As污染微生物修复提供菌株材料与技术应用思路。     

探析农村小学传统文化教育模式

《国家"十一五"时期文化发展规划纲要》指出:"重视中华优秀传统文化教育和传统经典、技艺的传承。在有条件的小学开设书法、绘画、传统工艺等课程,在中学语文课程中适当增加传统经典范文、诗词的比重,中小学各学科课程都要结合学科特点融入中华优秀传统文化内容。     

分子标记辅助选择育成抗稻瘟病粳稻新品种扬农粳3091

通过杂交及不完全回交,结合分子标记辅助选择,育成携带广谱抗稻瘟病基因Pigm的粳稻新品种扬农粳3091。选育过程中的稻瘟病抗性鉴定结果显示,携带Pigm基因品系的抗性水平显著好于对照。该品种于2021年通过江苏省农作物品种审定委员会审定,具有综合抗性好、品质优、丰产稳产性好等特点。本文介绍了该品种的选育过程、特征特性及主要栽培技术要点。     

滨海盐碱地转基因抗虫棉品种鉴选

为探明转基因抗虫棉的耐盐性，筛选出适合盐碱地种植的抗虫棉高产品种，不同盐分含量砂培试验与滨海盐碱地大田试验相结合。研究了不同基因型抗虫棉的耐盐性及其生育特点和产量表现。结果表明。供试抗虫棉品种间的耐盐性存在差异，但耐盐程度皆十分有限。从不同基因型抗虫棉的耐盐性、出苗成苗率、生长情况和产量等分析。以鲁棉研17、鲁棉研21、鲁536、中棉所45和鲁棉研18综合性状较好，适宜于盐碱地种植，可作为当前盐碱地植棉的适宜品种。     

桐花树毛颚小卷蛾生活史及食性初步研究

对泉州湾河口湿地红树林桐花树毛颚小卷蛾生活史及食性开展初步研究,结果表明：（1）桐花树毛颚小卷蛾在泉州湾地区1年发生8代,世代重叠,以幼虫在桐花树叶片上卷叶越冬,翌年3月上旬开始结茧化蛹,3月下旬开始羽化为成虫;1年内有2个明显的危害高峰期,分别出现在5月中旬和9月下旬。（2）桐花树毛颚小卷蛾是泉州湾红树林的主要害虫,该虫只取食桐花树,不取食秋茄和白骨壤。     

Role of endogenous vitamin E in renal ischemic preconditioning process: differences between male and female rats

Background: Antioxidants such as α-tocopherol (vitamin E) and β-carotene (vitamin A) play an important role in protective effect of repeated brief periods of ischemia, namely ischemic preconditioning (IPC). Values of these antioxidants were investigated and compared after induction of ischemia reperfusion (IR) and kidney IPC in both male and female rats. Methods: Forty eight Wistar rats were divided randomly into six groups of 8: groups A and B (male and female controls, respectively), group C (male IR or IR cases), group D (female IR cases) and groups E and F (male and female IPC cases, respectively). In groups C and D, ischemia was induced by clamping of left renal arteries for 45 min. In groups E and F, rats underwent four cycles of 4 min of arterial clamping and 11 min of de-clamping before final 45 min ischemia induction. Afterward, serum was collected to assess the blood urea nitrogen, creatinine and vitamins E and A values. Renal tissues were obtained for histological assessments. Results: α-tocopherol levels in male and female rats showed a significant increase in IPC compared with IR group (P<0.01) and also in female IPC compared with male IPC group. β-carotene levels had no significant variations. Histological evaluation showed that IR-induced renal injuries were less in female rats. Also, protective effects of IPC were more in female rats (P<0.01). Conclusions: Renal IPC reduced damages in both male and female rats, but tissue injuries in females were decreased much more along with the increase of endogenous vitamin E. Key Words: α-tocopherol, β-carotene, Antioxidant, Reperfusion, Ischemic preconditioning (IPC)     

Effect of oral administration of fenitrothion on biochemical and hematological parameters in rats

The aim of this study was to evaluate the effects of acute exposure to various doses of fenitrothion (FNT) on level of serum glucose, total protein, triglycerides (TG), total cholesterol (TC) and some hematological parameters. The study was conducted on 8-week-old male Wistar rats that divided into four groups (three experimental groups and one control group), were treated orally with different doses (25, 50 and 100 mg kg(-1)) of fenitrothion for 28 consecutive day. After treatment, blood samples were collected for biochemical and hematological studies. Present results demonstrated that exposed groups led to significant dose-dependent increase in serum glucose and cholesterol levels. Significant decrease was observed in some hematological parameters [Red Blood Cell (RBC) counts, Hemoglobin (Hb), Haematocrite (Ht) and Mean Corpuscular Hemoglobin (MCH) values]. Serum total protein and triglycerides were also decreased not significantly in exposed groups when compared with control. Generally, the degrees of observed variations were found to be dose dependent.     

森林生态蓄水功能的经济评价(个案研究:伊朗扎格罗斯森林)(英文)

森林生态服务直接或间接地造福人类。本文利用模拟模型和地理信息系统作为工具,分析生态因子对生态系统服务功能的作用,评估了伊朗西部扎格罗斯森林对Bazoft河流域水源保护的经济价值。应用HEC-HMS模型中的曲线数字法对降雨量-径流进行了模拟。该模型需要输入土地覆被、土壤、短期降雨和流出数据。用观测数据并分阶段校对对拟合模型的功效进行了修订。测定了森林在4种设定的土地覆盖方案中保水性和减少地表径流量的作用以及土地用途改变对该区降雨量-径流行为的影响。结果表明:方案一假定该流域全被森林覆盖,总的流出量将最小,降雨初期损失将增加。用重置成本法估算了森林水文功能之保水性经济价值。评估结果表明,每公顷Bazoft河流域的森林可以蓄存84.8立方米水,年产值0.5 US$/m3。因此,每公顷BazoR河流域的森林保水性经济评价值是43US$。说明覆被森林有利于该流域经济发展,该研究有助于决策者选择适当的、经济可行的发展策略。     

A comparison of root distribution of three hardwood species grown on a hillside in the Caspian forest,Iran

Slope is a complex environmental factor that can subject plants to a number of mechanical stresses. The anchorage of roots and improvement of slope stability mainly depend on specific properties of root systems, such as root distribution. In the present study, 24 trees (from three species) growing on gentle slopes (10–20°) were randomly chosen for root distribution analysis. The profile trenching method was used to obtain root characteristics. The findings indicated that root area ratio (RAR) decreased with depth and that maximum RAR values were observed in the upper layers; RAR values were between 0.0004% and 6.6444%. Average RAR values were not statistically different in upslope and downslope layers except in one case. The dot grid method (100 × 150 mm) usually overestimated the RAR values. The amount of roots decreased with depth following a power law. About 50% and 90% of roots were located in the first 30 and 60 cm depths, respectively. Results of analysis of covariance (ANCOVA) showed a significant effect of diameter at breast height (DBH) on total RAR but not on the total number of roots. About 70% of roots had diameter of less than 10 mm. Spearman’s correlation showed significant negative correlation between the total number of roots and the amount of N, P, and K elements, and a positive correlation between DBH and RAR. The results serve to develop understanding of the biotechnical characteristics of root systems of Caspian species.