Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.     

制动防抱死系统在汽车上的应用

在文中通过研究汽车制动时的受力情况、路面附着特性、制动防抱死系统的控制方式、组成和工作情况，得出了使车轮滑动率保持在20％的最佳状态可提高汽车的制动效能，缩短制动距离。并使汽车具有较好的转向和抵抗侧向力的作用，提高汽车制动时的方向稳定性的结论。     

NM－1号抗旱剂的研究

试验结果表明谷子在—１３．９Ｐａ的负压下发芽率只有２４．０％，在—１６．７３Ｐａ时发芽率为１６．３％。用０．５％的ＮＭ—１号抗旱剂包衣后，在—１６．７３Ｐａ的负压下发芽率可达６５．６％，比对照提高４９．３％。同０．５％的ＮＭ—１抗旱剂在大豆现蕾期喷施叶面１次，相对收获株率为１１５．３８％，相对千粒量为１０７．７％，增产率为４０，２７％。玉米在６叶期喷施０．５％的抗旱剂后，饱和亏减少４．０９ｇ，是对照的４３．８１％；干物质积累比对照快６７．１９％，蒸腾系数减少８．３６ｇ。     

手动比例复合阀在中高压液压绞纲机中的应用

中高压液压技术在海洋捕捞机械—绞纲机中的使用推动了我国渔业机械的发展,手动比例复合阀在中高压液压技术上的应用则大大加快了液压绞纲机在国内渔业生产中的普及。目前,我国浙江、江苏、福建、广东和山东等省沿海渔民使用的绞纲机普遍采用带手动比例复合阀的液压系统。为此,对手动比例复合阀换向、溢流、调速集成等功能进行了分析。     

Osmolarity,cell volume and proliferation in nasopharyngeal carcinoma cells

AIM: To investigate the relationship between osmolarity, cell volume and cell proliferation in nasopharyngeal carcinoma cells. METHODS: MTT method was applied to detect the proliferation ability of the poorly-differentiated nasopharyngeal carcinoma cell (CNE-2Z) under various osmolarity conditions. The flow cytometry was used to analyse cell cycle distribution. Cell volume was obtained by the image analysis of living cells and cell viability was determined by the trypan blue assay. RESULTS: Cultivation of cells under the hypertonic conditions of 370 and 440 mOsmol/L increased cell volume by 8.7% and 27.8% and facilitated cell proliferation by 22.2% and 33.9%, respectively. However, hypotonic incubation of cells with osmolarity of 160 and 230 mOsmol/L decreased cell volume by 12.8% and 4.1% and inhibited cell proliferation by 34.0% and 15.6%, respectively. Cell volume was positively correlated with cell proliferation rate. Long-term cultivation of cells under anisotonic conditions did not significantly alter cell cycle distribution, but hypotonic cultivation decreased cell viability. CONCLUSION: Proliferation of nasopharyngeal carcinoma cells was closely correlated with the osmolarity of culture medium and cell volume. Hypotonic cultivation may inhibit cell proliferation by decreasing cell volume to facilitate cell death mechanisms.     

Efficacy of a mephentermine‐based product as a vasopressor and a cardiac performance enhancer when given intramuscularly to cattle

The goal of this study was to confirm the vasopressor and cardiac effects of POTENAY^® INJETÁVEL (POT), a mephentermine‐based product, given to cattle with induced vascular/cardiac depression. Ten healthy Holstein cattle (206 ± 13 kg) followed a randomized‐complete‐block design (RCBD) utilizing crossover study design. Each animal randomly received (1 ml/25 kg, IM) of either POT (n = 10) or volume‐matched placebo control (0.9%NaCl, CP, n = 10). A subset of animals (n = 5) received POT first (day 0) while the remaining (n = 5) received CP; after a six‐day washout period, cattle received the opposite compound. Animals were anesthetized and catheterized for systemic/left ventricular hemodynamic monitoring. Myocardial dysfunction/hypotension was induced by increasing the end‐tidal isoflurane concentration until arterial blood pressure was 20% lower than at baseline and remained stable. Once the animal was determined to be hypotensive and hemodynamically stable, steady‐state hypotensive baseline data (BL2) were acquired, and treatment with either POT or CP was given. Data were acquired post‐treatment at every 15 min for 90 min. POT improved cardiac output (+68 L/min, ±14%, p < 0.05), MAP (+14 mmHg, ±4%, p < 0.05), HR (+22 bpm, ±8%, p < 0.05), and peak rates of ventricular pressure change during both systole (dP/dt_max: +37 mmHg/s ±13%, p < 0.05) and diastole (dP/dt_min: +31 mmHg/s, ±7%, p < 0.05). No improvements were noted following placebo‐control administration. Results indicate that POT improves cardiac performance and systemic hemodynamics in cattle with induced cardiovascular depression when given as single intramuscular injection.     

南海不同海域鸢乌贼生长与死亡参数比较

根据2011-2015年南海海域灯光罩网渔船捕获的鸢乌贼样品,利用Fisat II软件对南海鸢乌贼群体的生长死亡系数进行估算。结果显示：南海没有大型群鸢乌贼个体,且雌性个体（12.05cm）比雄性个体（10.91cm）大;南海北部和南部的鸢乌贼均呈正异速生长,胴长和体质量关系b值分别为3.470~3.605和3.379~3.773;生长参数K反映了南海北部更适合于雄性鸢乌贼生长;南海南部海域鸢乌贼雌性（1.84）和雄性（1.76）总死亡系数相差不大,开发较为均衡;南海北部海域鸢乌贼雌性（0.60）总死亡系数远小于雄性（4.83）,显示该海域鸢乌贼未能充分开发。从渔业资源开发的角度,渔业政策偏向于开发南海南部鸢乌贼资源,使得北部鸢乌贼资源未能充分开发,不利于南海鸢乌贼资源的可持续利用。     

Chemerin fragments show different effects on systemic blood pressure dependent on carboxyl-terminal cleavage site

Chemerin is an adipocytokine whose concentration in blood correlates positively with blood pressure (BP). We have recently revealed that acute intracerebroventricular (i.c.v.) injection of chemerin-9, an active fragment of human chemerin, increased systemic BP in normal Wistar rats, suggesting that chemerin is involved in the central nervous control of peripheral BP. After secreted as an inactive form as prochemerin, a mature form of active chemerin is produced through the cleavage of its carboxyl (C)-terminus by proteases. Although the activity of cleaved products of chemerin has been examined in vitro, in vivo effects remained to be elusive. In order to explore them, we performed acute i.c.v. injection of mouse chemerin-9 (mChemerin-9; 148F-156S), mouse chemerin-8 (mChemerin-8; 148F-155F), and mouse chemerin-7 (mChemerin-7; 148F-154A) into Wistar rats, and examined the effects on systemic BP. After chemerin fragment (1–30 nmol/head, i.c.v.) was cumulatively administered, systemic BP was measured by a cannulation method under an isoflurane anesthesia. mChemerin-9 but not mChemerin-8 and -7 induced a pressor response, which was concentration-dependent. In conclusion, we for the first time demonstrated that mChemerin-9 that corresponds to the C-terminal nine amino acids of active mouse chemerin156S increased systemic BP in rats, and also that chemerin fragments showed different effects on systemic BP dependent on how their C-terminus was cleaved.     

旋流泵的流动规律

对80X-13.5型旋流泵进行了数值模拟计算,泵内部流动区域选用Pro/E造型,用Gambit软件采用分块非结构六面体网格划分方法对模型进行网格划分及部分边界条件的设定,运用雷诺平均N-S方程和标准k-ε双方程湍流模型结合SIMPLEC算法,来数值模拟旋流泵内部三维不可压湍流场.数值模拟计算选取工作介质为清水,并认为是牛顿流体且局部各向同性;认为旋流泵的内部流场是以定常角速度绕固定轴的旋转流场,属于复杂的三维不可压湍流流动.数值模拟得出了旋流泵内的速度和全压分布图,并试分析出了旋流泵的内部流动区域分布.分析认为,周向流动是旋流泵内部的主体流动趋势,旋流泵内部流动状态可归结为贯通流和循环流.数值模拟的结果验证了已有流动模型的正确性,并且在数值模拟基础上重新划分的流动区域可以反映清水条件下80X-13.5型旋流泵的内部流动情况,可为此种泵型旋流泵的设计提供参考.