氮肥运筹对杂交苏丹草产量饲用品质及再生系数的影响

采用大田小区栽培试验,研究了氮肥对杂交苏丹草产量和饲用营养品质及再生系数的影响。结果表明,杂交苏丹草干物质总产量氮肥处理显著高于对照,N4处理最高,相同的施氮量分次施用比一次性施用增产效果好。氮肥处理粗蛋白(CP)含量均高于对照,头茬草CP含量最高,随收获次数增加,CP含量降低,分次施肥处理施氮量增加,CP含量降低。对照处理粗灰分(CA)含量最高,随收获次数增加CA和酸性洗涤纤维(ADF)含量降低,无氮浸出物(NFE)含量升高。杂交苏丹草5大营养成分产量均是N4处理最高,对照最低,CP产量顺序是N4>N1>N2>N3>N0,3次收获的粗脂肪(EE)、CA、ADF、NFE总产量,均是肥料分次施用比一次性施用的处理高。各氮肥处理总能量(GE)均高于对照,其中N4处理最高,其次是N2处理,分次施肥的处理有利于总能量的增加。再生系数表现为相同施氮量分次施用处理高于一次性施用的处理,N4处理可使杂交苏丹草再生系数达到最大。比较发现,生产上采用N4(600 kg/hm2,底肥∶追肥=1∶2)处理可获得高产优质的牧草。     

The relationship between serum IGF-1, IGFBP-3 levels,bone mineral density and bone metabolic markers in postmenopausal patients with osteoporosis

AIM:To study the relationship between serum insulin-like growth factor- 1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) levels, bone mineral density(BMD) and bone metabolic markers in postmenopausal women. METHODS:Serum IGF-1, IGFBP-3, osteocalcin(BGP), isomeric C-telopeptide of type I collagen (β-CTX), estradiol(E₂), calcitonin(CT), parathormone(PTH), calcium (Ca), and phosphorus(P) were measured in 90 postmenopausal osteoporosis patients and 70 healthy postmenopausal women. BMD of lumbar vertebra and left femoral neck were determined by dual energy X-ray absorptiometry.RESULTS:BMD of lumbar vertebra and left femoral neck decreased significantly (P<0.01), serum IGF-1, IGFBP-3, E₂, CT and BGP decreased significantly (P<0.01), serum β-CTX and PTH increased significantly in postmenopausal osteoporosis group (P<0.01). There were no significantly differences in serum Ca, P between two groups (P>0.05). BMD of lumbar vertebra and left femoral neck were positively correlated with serum IGF-1, IGFBP-3, E₂, CT and BGP, but negatively correlated with β CTX and PTH. There were no correlation with serum Ca, P and BMD.CONCLUSION:Serum IGF-1, IGFBP-3, E₂, CT, BGP, β-CTX and PTH level were correlated with BMD of lumbar vertebra and left femoral neck. These markers can be one of the valuable evidences for screening osteoporosis in postmenopausal women.     

Cardiomyocyte apoptosis and expression of Bcl-2, Bax protein after acute myocardial infarction and late reperfusion in dogs

AIM: To study the effect of late reperfusion on apoptotic cardiomyocytes in the risk area of acute myocardial infarctin in dogs. METHODS: The experiment was divided into three groups: sham operation group, acute myocardial infarction (AMI) group, and late reperfusion (LR) group. Apart from sham operation group, the other two groups were subjected to left anterior descending branch of coronary artery ligation. The acute myocardial infarction group was only subjected to ligation for 12 hours, late reperfusion group was subjected to ligation for 6 hours following by 6 hours of reperfusion. The cardiomyocyte apoptosis was measured by TUNEL assay. Immunohistochemistry and Western blotting analysis were used to detect the expression of Bcl-2 and Bax protein. RESULTS: The number of apoptotic cardiomyocytes in late reperfusion group was much less than acute myocardial infarction group (P<0.05), and increased significantily as compared with sham operation group (P<0.01). The expression of Bcl-2 protein was enhanced gently in late reperfusion group in contrast to acute myocardial infarction group, but no significant difference in the two groups (P>0.05) was observed, although it was much more in the two groups than that in sham operation group (P<0.01). The expression of Bax protein in late reperfusion group was much higher than that in sham operation group (P<0.01), and was lower than that in acute myocardial infarction group (P<0.05). CONCLUSION: Late reperfusion reduces cardiomyocyte apoptosis in the risk area of acute myocardial infarction. The mechanism may be that late reperfusion can decrease the expression of Bax protein.     

Alteration of efferent system functions in noise-induced hearing loss patients

AIM:To investigate the changes of efferent system functions in noise-induced hearing loss (NIHL) patients and find out a method of clinic diagnosis for NIHL.METHODS:The amplitudes of distortion product otoacoustic emission were measured with and without contralateral broad-band noise using Celesta-503 otoacoustic emission analyzer. The efferent system functions were evaluated by the amplitudes of contralateral suppression.RESULTS:The contralateral suppressions in NIHL patients were significant lower than those in control group in low frequency (0.75 kHz and 1 kHz) of DP-gram and low level primary tone in 2 kHz input/output function. There were no significant differences in contralateral suppressions of 4 kHz and 6 kHz input/output function between NIHL patients and control group.CONCLUSION:The contralateral suppressions in NIHL patients are lower than those in normal hearing subjects and the measurements of efferent system functions could be used in early detection and clinic diagnosis for NIHL.     

沙漠增温效应下绿洲棉花热量生产潜力分析

在新疆干旱区,由于暖季沙漠增温效应的影响,与沙漠相邻绿洲区的热量资源相对优越,为植棉提供了有利条件。但随着时空变化,绿洲棉花热量生产潜力也呈现出相应的分异规律。本文以新疆北疆玛河流域石河子平原绿洲区为例,将绿洲与沙漠联系起来考虑,分析了距沙漠不同距离梯度的绿洲区棉花热量生产潜力。结果表明:石河子平原绿洲区内,距离沙漠最近区与最远区之间棉花热量生产潜力相差389Kg/hm2,绿洲与沙漠的距离平均每增加10Km,热量生产潜力下降43Kg/hm2。暖季沙漠增温效应对绿洲棉花的热量生产潜力影响明显,沙漠对相邻绿洲区的农业生产有着正面影响,起到了除太阳外第二个热量源的作用。     

新疆旅游经济非均衡演变的时空特征分析

本文以区域经济学为基础,运用标准差和变异系数等方法,分析了新疆15个地州近10年旅游经济的区域非均衡发展的总体水平及时空特征,揭示了新疆旅游经济水平在国民经济中产业地位的分异规律,探讨了旅游区域差异的动因,提出了缩小地区差异、协调新疆旅游业发展的对策。     

和田河流域绿洲荒漠过渡带土地荒漠化过程研究

和田河流域绿洲荒漠过渡带属于典型的生态脆弱带,风动力是该区土地荒漠化的主要动力因素,植被是该区土地荒漠化的重要决定因子。本文根据风洞试验的结果,探讨了和田河流域绿洲荒漠过渡带土地荒漠化的正过程。指出该区的土地荒漠化是在南疆气候变异以及人类活动等原因造成的干旱地区土地退化的大环境下发生的;同时,该地区的土地荒漠化又有特定的内涵:以天然绿洲的土地退化为本质;人类活动加速了这一过程。该区域土地荒漠化的发生和发展与其物理学驱动机制有着良好的对应关系。根据土地荒漠化发展的不同阶段,可以将其划分为荒漠河岸林衰退期、灌丛沙堆稳定发展期、灌丛沙堆活化-荒漠化发展期。     

毛乌素沙地臭柏、油蒿细根生产动态及影响因子

在毛乌素沙地开发整治研究中心北试实验地选取了七块样地,并依据建群植被外貌特征划分为臭柏群落、臭柏灌丛、油蒿群落三类。用根钻对各样地一个生长季内的根系进行了五次取样,同时测量土壤水分、枝条生长长度、温湿度等一些气象因子。对活细根分级并称干重,发现臭柏、油蒿不同径级细根的季节动态不同,不同土层内相同径级的细根生产动态也不相同:①臭柏与油蒿D≤2 mm的细根生物量在4~5月份都有一个快速增长的阶段,随后增长格局各不相同。②臭柏灌丛中,1 mm相似文献   

农牧交错带不同封育时间对植物特征值及多样性的影响

为研究我国北方农牧交错带不同封育时间对干旱、半干旱草原植物特征值及多样性的影响,同时探索农牧交错带草原封育周期,本研究选取位于我国农牧交错带的宁夏盐池人工封育草原为研究对象,采用样方调查法,于每年7-8月份(植物生长季节)对封育区植被生长状况进行调查,调查内容包括:植物名称、植物种数、株数、盖度、高度、地上生物量(鲜重)等。运用生态学、地统计学原理,结合Biodiversity Pro、Microcal Origin等生态学统计软件对外业数据进行处理、分析,结果表明:封育2-3年后植物群落优势种优势地位得到巩固,而一些伴生种则在竞争中消失;封育区植物特征值在封育2-3年后达到最大,如地上生物量(鲜重)在封育3年达到最大值,为6907.75kg/hm2,此后呈下降趋势;封育区主要植物重要值及植物物种多样性均在封育2-3年后出现最大值,此后也不同程度地呈下降趋势。