Possibilities of direct introgression from Brassica napus to B. juncea and indirect introgression from B. napus to related Brassicaceae through B. juncea

The impact of genetically modified canola (Brassica napus) on biodiversity has been examined since its initial stage of commercialization. Various research groups have extensively investigated crossability and introgression among species of Brassicaceae. B. rapa and B. juncea are ranked first and second as the recipients of cross-pollination and introgression from B. napus, respectively. Crossability between B. napus and B. rapa has been examined, specifically in terms of introgression from B. napus to B. rapa, which is mainly considered a weed in America and European countries. On the other hand, knowledge on introgression from B. napus to B. juncea is insufficient, although B. juncea is recognized as the main Brassicaceae weed species in Asia. It is therefore essential to gather information regarding the direct introgression of B. napus into B. juncea and indirect introgression of B. napus into other species of Brassicaceae through B. juncea to evaluate the influence of genetically modified canola on biodiversity. We review information on crossability and introgression between B. juncea and other related Brassicaseae in this report.     

高效液相色谱法测定黄皮果实中的有机酸

为深入了解黄皮果实中有机酸,采用水浴超声提取果实中的有机酸、高效液相色谱法测定的方法,对12份黄皮种质果实中有机酸的组分及含量进行研究。结果表明:在色谱柱Venusil XBP C18(T)(4.6 mm×250 mm,5μm)、流动相为0.01 mol/L(NH4)2HPO4(H3PO4调p H至2.7)、流速1 m L/min、柱温27℃、检测波长210 nm的条件下,黄皮果实中柠檬酸、草酸、乳酸、苹果酸、抗坏血酸、酒石酸得到良好分离,且测定精确灵敏、回收率高、重复性好,标准曲线相关系数为0.9975~0.9996,相对标准偏差为1.02%~1.84%,回收率为95.60%~101.78%。黄皮果实中有机酸以柠檬酸、草酸和苹果酸为主,乳酸在少部分种质中有测出,不同种质果实中柠檬酸、草酸、苹果酸含量分别为0.780~8.090、0.773~4.205、0.478~3.212 mg/(g·FW),分别占总酸的22%~65%、16%~40%、11%~20%。     

Immune Responses and Resistance against Vibrio parahaemolyticus Induced by Probiotic Bacterium Arthrobacter XE-7 in Pacific White Shrimp, Litopenaeus vannamei

A 63-d feeding experiment was conducted to determine the effects of dietary supplementation of probiotic bacterium Arthrobacter XE-7 on immune responses and resistance against Vibrio parahaemolyticus in the Pacific white shrimp, Litopenaeus vannamei . The probiotic bacteria were administered orally at four different doses of 0, 10⁶, 10⁸, and 10¹⁰ colony-forming unit (CFU)/g feed for shrimp. On Day 50, the shrimp were challenged with Vibrio parahaemolyticus by bath. On Days 7, 21, 49, and 63, six shrimp per tank were sampled to take intestine and hemolymph. With increasing dietary supplementation of probiotic bacteria, shrimp mortality decreased from 63.16% (the control) to 55.9% (10⁶ CFU/g feed), 51.75% (10⁸ CFU/g feed), and 51.78% (10¹⁰ CFU/g feed), respectively. Vibrio counts in intestine of shrimp fed probiotic bacterium Arthrobacter XE-7 was generally lower than that in the control shrimp ( P  < 0.05). The probiotic bacteria generally increased the immune parameters in shrimp, that is, total hemocyte counts, percentage phagocytosis, respiratory burst activity, and serum phenoloxidase activity. The results showed that probiotic bacterium Arthrobacter XE-7 can be used as probiotic in shrimp feed.     

滴灌条件下西北干旱区农田生物排盐研究进展与展望

20世纪末以来,膜下滴灌技术在我国西北干旱区得到了大规模的推广和应用,极大推动了绿洲农业的发展。然而,滴灌带入盐分无法排出导致的农田土壤积盐问题,使得干旱区绿洲农业的可持续发展面临巨大挑战。如何在水资源短缺的情况下防治农田次生盐渍化和利用西北干旱区广泛分布的盐碱地资源,是我国干旱区农业可持续发展中迫切需要解决的问题。本文结合西北干旱区膜下滴灌农田水盐运移的特点,主要从盐生植物耐盐机制及其生长发育对盐分的响应、盐生植物排盐与盐碱土改良的互馈效应以及种植盐生植物对土壤水盐动态的影响等方面对生物排盐的研究进展进行了比较系统的梳理,同时指出了目前西北干旱区在农田生物排盐研究方面存在的不足,并对今后需要开展的研究工作进行了展望,以期为旱区农业制定合理高效的综合排盐制度提供决策依据,对于实现农田盐分平衡、缓解土壤次生盐渍化危机和土壤可持续利用具有重要意义。     

ASSOCIATIONS BETWEEN ULTRASOUND AND CLINICAL FINDINGS IN 87 CATS WITH URETHRAL OBSTRUCTION

Urethral obstruction is a life‐threatening form of feline lower urinary tract disease. Ultrasonographic risk factors for reobstruction have not been previously reported. Purposes of this retrospective cross‐sectional study were to describe urinary tract ultrasound findings in cats following acute urethral obstruction and determine whether ultrasound findings were associated with reobstruction. Inclusion criteria were a physical examination and history consistent with urethral obstruction, an abdominal ultrasound including a full evaluation of the urinary system within 24 h of hospitalization, and no cystocentesis prior to ultrasound examination. Medical records for included cats were reviewed and presence of azotemia, hyperkalemia, positive urine culture, and duration of hospitalization were recorded. For medically treated cats with available outcome data, presence of reobstruction was also recorded. Ultrasound images were reviewed and urinary tract characteristics were recorded. A total of 87 cats met inclusion criteria. Common ultrasound findings for the bladder included echogenic urine sediment, bladder wall thickening, pericystic effusion, hyperechoic pericystic fat, and increased urinary echoes; and for the kidneys/ureters included pyelectasia, renomegaly, perirenal effusion, hyperechoic perirenal fat, and ureteral dilation. Six‐month postdischarge outcomes were available for 61 medically treated cats and 21 of these cats had reobstruction. No findings were associated with an increased risk of reobstruction. Ultrasonographic perirenal effusion was associated with severe hyperkalemia (P = 0.009, relative risk 5.75, 95% confidence interval [1.54–21.51]). Findings supported the use of ultrasound as an adjunct for treatment planning in cats presented with urethral obstruction but not as a method for predicting risk of reobstruction.     

散体物料孔隙率测定装置设计与试验

为了提高散体物料孔隙率检测精度及可靠性,基于理想气体状态方程,按照气体置换法,研制了一种定容型散体物料孔隙率的快速测定装置,开发了自动检测控制系统。在设定的0.1~0.4 MPa测量范围内,采用可精确测得其体积且形态各异的标准不锈钢球体、塑料四棱柱体、鹅卵石以及细石子的试验结果发现,系统的充气压力越高,测量误差相对越小且重复性越好。采用标准不锈钢球体与圆柱体,在孔隙率分别为16.02%、25.14%、35.57%、49.05%、58.42%、67.79%、76.57%、85.36%、94.14%的标准条件下,给出了补偿系数的计算式。在样品填充率分别为25%、50%、75%、100%,充气上限压力为0.4 MPa的试验条件下,检测湿基含水率为13.5%的稻谷的试验结果显示,测量误差极差为0.3%,证实了测量结果的可靠性。     

Optimal dietary protein requirement of grouper Epinephelus coioides juveniles fed isoenergetic diets in floating net cages

An experiment to determine the optimal protein requirement of grouper Epinephelus coioides juveniles was conducted in floating net cages (1.5 m × 1 m × 1.5 m). Six isoenergetic fishmeal–casein‐based experimental diets containing 350–600 g kg^?1 crude protein (CP) were fed to triplicate groups of 20 fish (10.7 ± 0.2 g) for 56 days. Weight gain (WG) and specific growth rate (SGR) increased with increasing dietary protein level from 350 to 450 g kg^?1 and then plateaued above these levels. Feed intake (FI) showed no significant difference among fish fed more than 350 g kg^?1 CP. Lowest feed conversion ratio (FCR) was found for fish fed 500 g kg^?1 CP but this was not significantly different from that of fish fed the 450 and 600 g kg^?1 CP. Lowest protein efficiency ratio (PER) was found for fish fed 550 and 600 g kg^?1 CP. Fish fed the 600 g kg^?1 CP had the highest body protein and moisture contents but the lowest body lipid content. Body ash content was unaffected by protein level for fish fed >400 g kg^?1 CP. Dietary protein level had no significant effect on hepatosomatic index (HSI). Fish fed the 350 g kg^?1 CP had significantly lower condition factor (CF) and viscerosomatic index (VSI). Based on broken‐line regression analysis of SGR the optimal dietary protein requirement for E. coioides juveniles was determined to be close to 480 g kg^?1.     

椿皮中一种抗癌成分的提取与结构鉴定

研究了臭椿皮中抗癌活性物的快速提取分离方法。对所提取物用TLC检测,表明得到的化合物为纯净物。通过用MS、1HNMR、13CNMR、1H—1HCOSY、1H—13CCOSY、DEPT等光谱法分析鉴定,确定该提取物为苦味素A。     

Lhx2 selector activity specifies cortical identity and suppresses hippocampal organizer fate

The earliest step in creating the cerebral cortex is the specification of neuroepithelium to a cortical fate. Using mouse genetic mosaics and timed inactivations, we demonstrated that Lhx2 acts as a classic selector gene and essential intrinsic determinant of cortical identity. Lhx2 selector activity is restricted to an early critical period when stem cells comprise the cortical neuroepithelium, where it acts cell-autonomously to specify cortical identity and suppress alternative fates in a spatially dependent manner. Laterally, Lhx2 null cells adopt antihem identity, whereas medially they become cortical hem cells, which can induce and organize ectopic hippocampal fields. In addition to providing functional evidence for Lhx2 selector activity, these findings show that the cortical hem is a hippocampal organizer.     

母婴间铁锌铜代谢关系的研究

同步检测了１２６例对正常产妇及其产生儿，采用原子吸收分光光度法测定血清和红细胞铁、锌、铜含量并用放射免疫法测定血清和红细胞铁。结果：（１）血清铁蛋白≥１４μｇ／Ｌ的产妇，其婴儿脐血清铁蛋白高于母亲血清蛋白〈１４μｇ／Ｌ的婴儿，但两组婴儿的血红蛋白，血清铁，红细胞的及红细胞铁蛋白含量相近。（２）婴儿脐血清锌高于母血，而红细胞锌则低于母血；（３）婴儿脐血清铜显著低于母血，而红细胞铅则高于母血。