Performance of Amblypharyngodon mola with Barbodes gonionotus, Cyprinus carpio and Macrobrachium rosenbergii in rice-fish culture system

An experiment was conducted to assess the performance of mola (Amblyphmyngodon mola) in rice fish culture system with freshwater prawn Macrobrachium rosenbergii), Thai silver barb (Bm·bades ganianotus) and common carp (Cyprinus cmpia) for a period of 4 months at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, Bangladesh. Four treatments viz., treatment-I (T1) with A. mala and M. rosenbergii; treatmen t-II (T2) with A. mala, M. rosenbergii and B. gonianatus ; treatmentIII (T3) with A. mala, 1Vf. rosenbergii and C. cmpia, and treatment- IV (T4) as control (without fish) were used in triplicate. All treatments were equally fertilized with urea (200 kg/ha), TSP (150 kg/ha) and MP (75 kg/ha). The mean values of water quality parameters viz., temperature, dissolved oxygen, pH, nitrate-nitrogen showed a very small variations among different treatments, but phosphate-phosphorus and chlorophyll-a were relatively higher in T4 without fish (i.e., control). The fish production of 480.5 kg/ha in T3 was significantly higher than that of 355.6 kg/ha T2 and 223.8 kg/ha in T 1• The values of soil organic matter, total-nitrogen, phosphorus and potassium at harvest were significantly (P<0.05) higher in the treatments with fish than without fish, but pH did not show any significant differences. The yield of rice grain and straw was also obtained significantly (P<0.05) higher in the treatments with fish. The increase in grain was higher over the control by 11.81%, 9.41% and 14.76% and that in straw was by 9.83%, 4.77% and 13.29% in Tl> T2, and T3 respectively.

大蹼铃蟾抗肿瘤蛋白及其制备方法和其基因

本发明涉及大蹼铃蟾抗肿瘤蛋白及其制备方法和其基因，属于生物医学领域。抗肿瘤蛋白是从中国两栖类动物大蹼铃蟾皮肤分泌物中分离得到的一种单链多肽，分子量2697，等电点9.83，多肽氨基酸全序列一级结构为：NH2－GIGGKILSGLKTALKGAAKELASTYLH－NH2。制备方法是收集大蹼铃蟾皮肤分泌物，离心去除沉淀、冷冻干燥后，经离子交换、高压液相反相柱层析分离纯化后得到。由650、623、625个核苷酸组成的三个不同的基因可编码大蹼铃蟾抗肿瘤蛋白，编码成熟抗肿瘤蛋白分别为第177－257位、第166－246位、175－255位核苷酸。具有抑制肿瘤细胞生长、抗艾滋病病毒活性和抑制细菌和真菌生长的作用。

黄土丘陵区植被次生演替灌木初期的土壤养分特征

对黄土丘陵区植被次生演替灌木初期的土壤养分特征进行了研究。结果表明:灌木初期土壤养分含量总体上表现出0~20 cm土层明显高于20~60 cm土层,而20~40 cm和40~60 cm间无显著差异。0~60 cm土壤深度内,土壤养分因子含量平均值变化范围分别为:有机质4.66~9.83 g.kg-1,全氮0.33~0.61 g.kg-1,全磷0.49~0.52 g.kg-1,有效氮21.56~41.80 mg.kg-1,有效磷0.73~1.31 mg.kg-1,有效钾58.31~102.01 mg.kg-1。灌木初期的土壤养分条件略好于草本阶段,说明植被演替草本阶段对土壤的培肥作用为群落向灌丛演替阶段发展提供了一个较好的土壤养分环境。灌木初期不同,灌木树种间的土壤养分条件存在一定差异,表明不同灌木树种定居所需适宜的土壤养分条件也不同;灌木初期除土壤全磷外,其他各养分因子间均表现出极显著线性相关关系(P<0.01)。

尿素氮行为的生态环境效应及其土壤生物化学调控

运用示踪尿素，以壤质草甸棕壤和春小麦分别作供试土壤和作物进行盆栽试验。结果表明，在试验结果时，植株和土壤对尿素氮的回收率及其损失分别占所施氮量17.65～23.69%，43.72～56.32%和19.99～36.77%。氢醌（HQ）和双氰胺（DCD）组合可使土壤、植株尿素氮回收率最高、损失量最低；而单施HQ或DCD均对比无明显影响。在小麦整个生育期内，该组合可增加小麦植株对肥料氮吸收；同时促进茎秆中氮向籽实转移。配施抑制剂时，土壤有机氮占肥料氮回收率相当大的比例，小麦成熟期时可达34.31～51.80%，而单施尿素处理只有9.83%；DCD及其与HQ组合可有效地保持尿素水解后土吉氨态氮含量，并显著降低土中氧化态氮的富集。因此，配施抑制剂，尤其是HQ+DCD，有利于尿素施放后土壤持续有效地保持肥粒氮量。大氮素损失方面，N_2O只占较小的比例；主要部分为NH_3挥发损失。DCD，尤其与HQ组合，可延迟尿纱施入后土壤-小麦系统中N_2O排放高峰的出现，并降低小麦整个生育期内该系统中N_2O排放总量和NH_3挥发量，尤其是后者。配施抑制剂，尤其是DCD及其与HQ组合，可明显促进稻株地上部分生长，制约水稻拔节期前根际内土中尿素水解后无机氮行为；显著提高尿素施入后稻田系统中水-土和根-土界面CH_4氧化潜势，尤其大水稻分蘖-拔节期。表施有机物料可显著削弱上述抑制剂的促进作用。未施有机物料时，配施抑制剂，尤其是DCD及其与HQ组合可显著降低稻株地上部分NO_3~--N含量。其含量与土壤-水稻系统中N_2O排放量呈显著指数正相关；同时无明显稻株释放N_2O，而单施尿素处理却较高，占尿素氮量0.47 ± 0.08%。表施麦秸粉时，HQ+DCD可显著降低土壤和土壤-水稻系统中N_2O排放量；单施尿素处理水稻植株释放N_2O约占尿素氮量1.28 ± 0.18%，而配施DCD-HQ却显著降低，只为0.66 ± 0.08%。回归分析表明，土-水界面土壤中NO_3~--N的反硝化作用是稻田系统中N_2O排放的主要来源，尤其在表施有机物料时。我们研究显示：稻田系统中N_2O和CH_4排放量呈显著对数负相关关系；表施有机物料时，两者虽互为消长关系，但很难定量化。

两段组合式好氧生物处理方法（AS/UABF）设计与工艺研究

本项研究综合了活性污泥法、生物滤池法、AB法、上流好氧活性污泥床的处理特点，设计了两段式活性污泥-上流式活性生物滤池组合污水处理工艺（AS/UABF），并对工艺条件进行了系统研究。结果表明，通过合理的设计与组合，该工艺中显示出两段工艺的组合协同协应，系统的处理能力高于单元处理能力，AS段具有大幅度削减污染负荷的能力，UABF段保证了出水水质。污水经初淀池后进入活性污染池，HRT为1h，通过活性污泥去除、吸附大量悬浮物和有机污染物，污染物浓度大幅度降低。COD去除负荷为2.05kgCOD/m~3.d，BOD去除负荷达1.82kgBOD_5/m~3.d，COD、BOD、SS可降低48～65%；然后进入上向流生物滤池，水力停留时间为3小时，利用生物膜的净化能力对污水进一步处理，然后进入沉淀池，最后出水的COD < 25mg/L，BOD < 5mg/L，SS < 5mg/L，NH_3-N < 2mg/L，出水指标可达到回用水质量标准。AS/UABF的两段一体化设计保证了系统的稳定运行，有效地控制了污泥膨胀的了发生，在对进水负荷、毒物冲击方面也表现也很好的抵抗能力，并有脱氮、脱磷作用。该技术可用于生活污水、中等浓度有机废水的处理。为进一步优化AS/UABF的净化效率，本项研究对AS/UABF的布水方式进行了改进，在UABF底部增设了第二个布水点。试验结果表明，在有机负荷分别为0.86，1.20，1.40，1.54kgDOB_5/m~3.d的情况下，BOD_5的去除率为96.9%，92.7%，88.6%，85.8%，COD去除率为90.6%，89.1%，86.9%，83.9%，系统的处理能力进一步提高。

碱法草浆造纸蒸煮黑液厌氧生物降解性及其主要微生物类群研究

造纸行业是造成我国水环境有机污染物的重要污染源之一，其水污染的特点是小厂多、草浆多、工艺落后、污染扩散面广、造成废 水排放量大，每年排放的废水量约39亿立方米，占全国工业废水排放量的1/6，其中有机污染物（以BOD5计）160万吨左右，约占全 国工业废水中有机污染物总量的1/4。尤以占全国制浆造纸行业90%以上的碱法草浆造纸厂的蒸煮黑液量大面广，除含有机物外，还 含有木质素、残碱、硫化物、氯化物等污染物，属于PH值高、色度深、难于治理的高浓度有机废水，对水体污染特别严重，各地要 求治理呼声很高，急待研究并尽快找出各种有效的治理途径。对于碱法草浆蒸煮，黑液高浓度废水的治理，有各种方法，根据国内 的研究进展和我们已有试验工作表明，最经济有效，具有实用价值，在生产上可获得成功是厌氧处理法。近10多年来，国外关于高 效厌氧处理技术研究进展迅速，并出现了多种多样的工艺设备，如高效厌氧生物反应器，并在实用化方面取得了很大成绩，建立了 生产性装置，达到了高负荷运行，效果良好。本试验是根据我们已有研究基础，针对我国国情，对小型制浆造纸厂水污染防治除了 开发碱回收及各种综合利用技术外，要特别加强废水(废液)实用技术研究的指导思想，本试验采用改进型的上流式厌氧污泥床反应 器，设计了两种试验方案，通过试验结果如下。1. 试验方案I—碱法草浆黑液酸化和厌氧发酵I号UASB反应器动态模型试验结果表 明：(1). 采用中温35℃±1℃高效厌氧反应器USAB内装有填料(陶粒)和三相分离器，具有保持高浓度生物量和防止污泥流失的特点 ，污泥浓度Vs 可达30%以上，因而具有高效、节能、产能、滞留期短的优点，当进水CODcr在7500-10000mg/l，HRT由7天缩短到3天 ，有机容积负荷在1.22gCODcr/l·d-3.43gCODcr/l·d时，CODcr平均去除率可达55%-45.5%，最高CODcr去除率可达60.2-63.5%， BOD5去除率可达75.9-83.2%,沼气容积产气率可达0.29-0.67l/l·d，每克CODcr转化为沼气产率达0.39-0.48l/gCODcr·d，CH4含量 65.8-75.5%。厌氧发酵出水再用化学法进行后处理脱除难降解的木质素，CODcr总去除率达80%以上。(2). 动态试验结果表明：采 用酸化—厌氧发酵处理黑液工艺合理，技术路线可行。2. 试验方案II—黑液用化学法(Hcl)去除木质素进行厌氧发酵，II号UASB反 应器动态模型试验结果表明：(1). 采用中温35℃±1℃高效厌氧反应器UASB(内有软填料)，当进水CODcr7000-13000mg/l左右，HRT 由6天缩短到1天，有机负荷由0.98gCODcr/l·d增加到11gCODcr/l·d时，COD平均去除率均可稳定在70-77%，BOD5去除率为87.3- 93.1%，沼气容积产气率0.21-2.6l/l·d，每克CODcr转化为沼气产率为0.39-0.48l/gCODcr·d，高的可达0.53l/gCODcr·d，转化 率较高，CH4含量63-70%。(2). 试验证明碱法草浆黑液物化预处理—厌氧发酵处理的技术路线也是可行的，工艺合理、效果较好。 在有条件的工厂可采用。3.厌氧发酵阶段几大类群微生物计数表明：(1). 当发酵工艺和运行处于相对稳定状态时，微生物群体的 组成也达到相对的稳定，各类微生物之间保持动态平衡关系。当产乙酸菌的数量为107-108个/ml时，产甲烷菌的数量为105-106 个/ml，当产乙酸菌数量为106-107个/ml时，产甲烷菌的数量为103-105个/ml。(2).稳态运行条件下，黑液预处理为甲烷发酵创造 了有利的生态环境，获得了较好的处理效果和较高的COD转化为沼气的产率0.39-0.48l/g·CODcr·d，反应器中形成较为稳定而数 量较下水污泥中高1-2个数量级的厌氧发酵微生物区系组成。这一结果为黑液厌氧发酵提供了微生物理论依据。Paper industry is one of the important pollution source of water environment in our country. Its character of water pollution is many small factories, much grass pulp, disadvantageous technique, large preading area of pullution. Its effluent makes up 1/6 of whole country's industry wastwater. Its organic pollutant accounts 1/4 of whole country's. Alkaline grass paper pulp effluent with pollutants such as ligoin, remaining alkali sulfide, chloride besides organic material, is a kind of high concentrate organic wastewater which has high PH walug, dark colour and is difficult in treatment. There is urgent require to find ways to treat the wastewater. There are different ways to treat alkaline paper grass pulp effluent. According to the research advances and our experiment work, the most economical and useful way is anaerobic degradation which was advanced quick in last ten years. In the control of waste water of small pulp paper mill, the study of wastewater utilization technology should be emphasized, besides alkaline retrieving and different kinds of comprehensive utilization technology. Our experiment used modified UASB(Upflow Anaerobic Sludge Blanket Reactor). Two kinds of plan were disgned. The results are lined below. 1. The first experiment plant-aciding black pulp effluent and methanogenic digestion. The dynamic model experiment results of I-UASB reactor showed: (1)The mesophilic(35℃±1℃)high effect UASB reactor having haydite and threee state seperation in it had the character of keeping high bioimass concentration and preventing losss of sludge. It had advantages of high effect, energe saving, energe prodcing and short HRT(Hydroulic retention time). When the influent COD was 7500-10000mg, HRT was shortened from 7 days to 3days, organic loading rate was 1.22g-3.43COD/l· d, the average COD removal efficiency was 55%-45%. The highest COD efficiency was 60.2-63.5%, BOD removal of 75.9 -83.4% was achieved. Biogass production rate were up to 0.29-0.67l/l·d. Biogass converted efficiency from every gram of COD could reach 0.39-0.48l/gCOD·d. Methane content was 65.0-75.5%. Chemical method was used to deplate lignin in anaerobic digestion effluent. Total COD removal efficiency could be more than 80%. (2)Using aciding annaerobic digestion to treat the black effluent was reseanable in technique and technology. 2. The second experiment plan-anaerobic digestion was used after the chemical method was used to deplate lignin in the black effluent. The result of dynamic experiment of II-UASB reactor showed: (1)High effect mesophilic (35℃±1℃)UASB reactor having soft slaffing in was used. When influent COD was about 7000-13000mg/l, HRT was shortened from 6 days to 1 day and organic loading rate was increased from 0.90 to 11g COD /l·d, average COD removal efficiency remained stable on 70-77%. BOD, removal efficiency was between 87.3-93.1%. Biogass production rate was 0.2-2.6l/l ·d .Biogass converted efficiency from a gram of COD was 0.39-0.481/gCOD·d with the high value of 0.53l/gCOD·d. Methane content was 63-70%. (2)The way that using physical, chemical Pre-treatment-anaerobic digestion to treat alkaline black effluent is feasible and can be used in some factories when the condition exists. 3. Counting of several class of microoganisms in anaerobic digestion stage showed: (1)As the disgestion was in stable motion, the compositon of microorganic colony could get relative stable. Dynamic balance was remaining among different kinds of microorganism such as methanogenic bacteria, Acidogenic bacteria, sulfate reducing bacteria, and heterotrophic bacteria. (2)Under stable motion, the pre-treatment of black effluent produced favourable eco-enviroment for methanegenic digestion. Good treatment effect and high biogass convertent efficiency from COD(0.39-0.48l/g·COD· d)were gotten. Some stable and high quantity(10-100times more than sewage sludge)microorganism colony were formed in the reactor. This result provided theoretical basis for anaerobic digestion of black effluent.

HIRFL剥离器后切束线物理设计

HIRFL is a tandem cyclotron complex for heavy ion. On the beam line between SFC and SSC, there is a stripper. Behind it, the distribution of charge states of beam is a Gauss distribution. The equilibrium charge state Q_0 is selected by 1BO2(a 50° dipole behind the stripper) and delivered to SSC. One of two new small beam line (named SLAS) after 1B02 will be builded in or der to split and deliver the unused ions of charge states (Q_0 ± n) to aspecific experimental area. Q_0 ± n ions are septumed and separated from initial(Q_0) ion beam by two septum magnets SM1, SM2. The charge state selected by SM1 will be Q_0 ± 1(6 ≤ Q_0 < 17), Q_0 ± 2(17 ≤ Q_0 < 33) and Q_0 ± 3 (Q_0 ≥ 33) forming a beam in one of the two possine new beam line with the stripping energy of (0.2 to 9.83 Mev/A), an emittance of 10π mm.mrad in the two transverse planes and an intensity ranging from 10~(11) pps for z ≤ 10 to some 10~5 pps for the heaviest element. Behind SM2, a few transport elements (three dipoles and seven qudrupoles) tra nsport Q_0 ± n beam to target positions T1, T2 (see fig. 1) and generate small beam spots (φ ≤ 4mm, φ ≤ 6mm). The optics design of the beam line has been done based on SLAC-75 (a first and second - order matrix theory). beam optics calculation has been worked out with the TRANSPORT program. The design is a very economical thinking, because without building a new accelerator we can obtain a lower energy heavy ion beam to provide for a lot of atomic and solid state physical experiments

科尔沁草甸草地放牧和割草条件下土壤种子库研究

研究了科尔沁沙地草甸草地在放牧、割草两种利用方式下的土壤种子库的大小、组成及其与地上植被的关系 .结果表明 ,在自由放牧下 ,土壤种子库密度为 6 15 8± 16 4 7粒·m-2 ,在割草利用下 ,土壤种子库密度为 8312± 2 5 4 0粒·m-2 .放牧干扰下 ,种子库组成以矮小、短命的一年生植物为主 ,其中一二年生植物占 81 6 6 % ,占比例最大的前 4种植物分别为虎尾草 (38 5 5 % )、灰绿藜 (15 4 2 % )、毛马唐 (14 95 % )和狗尾草 (9 83% ) ,多年生植物种子密度仅为 112 9± 30 2粒·m-2 ;割草干扰下 ,一二年生植物占6 8 0 8% ,其中狗尾草占 5 2 7% ;而割草地多年生植物种子密度为 2 6 5 3± 811粒·m-2 放牧地土壤种子库密度与地上植物相关不显著 ;割草地土壤种子库密度与地上植物多度显著相关 (r=0 76 ,P <0 0 1) .放牧地种子库的Shannon Wiener指数、丰富度指数分别为 2 96和 2 98,明显小于割草地的 3 10和 5 0 9,表明自由放牧更易使物种多样性下降 .

辽东山区长白落叶松(Larixolgensis)种子雨和种子库

长白落叶松是东北地区主要的用材树种,其种子雨和种子库研究鲜见报道。在辽东山区用收集器收集的种子分析了长白落叶松种子雨组成、质量和扩散距离,每隔2个月调查1次种子库数量,并结合靛蓝染色法测定每次种子的活力来分析土壤种子库动态。结果表明,辽东山区的长白落叶松种子雨从8月中旬开始,9月末到10月初达到高峰期,11月初结束。在起始期,种子雨以干瘪的不完整种子为主,而从高峰期开始,种子雨以完整种子为主。整个长白落叶松种子雨中不完整种子约占种子雨总量的45%,这些不完整种子由被动物取食、空粒和病虫害危害种子组成。完整种子的平均生活力为56.4%,即有活力的种子仅占整个种子雨的30%。种子雨集中在母树周围,在林缘1次扩散距离一般不超过1.5倍树高。种子雨到达地面之后,主要分布在枯枝落叶层,土壤0~5cm层有少量分布,土壤5 cm以下没有种子分布;土壤种子库的种子主要在翌年雪融化后开始萌发、被取食、搬运以及腐烂,其中腐烂种子数占45.4%,动物取食为30.0%。种子库的种子数量和活力在冬季没有明显变化,而在翌年,种子数量和活力明显减少,4、6月和8月份种子数量分别为(506.3±35.56)粒m-2,(267.1±17.47)粒m-2和(143.6±9.83)粒m-2,对应的活力分别为47.8%±4.68%,19.4%±3.39%和0%,这表明长白落叶松种子不能在地面形成连续的种子库。

气候变化条件下东北森林主要建群种的空间分布

全球气候模型HADCM2SUL和CGCM1分别预测100a后全球年均温增加3.7℃和5.2℃,年降水增加30.7%和25.1%。为了研究东北森林对这两种预测方案的反应,使用logistic回归模型分析了东北森林8个建群种与11种环境因子之间的相关关系。结果表明,除了山杨和蒙古栎之外,年均温是决定其它树种存在与否的重要因子。采用模型结果预测现行气候条件下8个树种的分布并与其现实分布比较,发现针叶树种的总正确率、敏感度、指定度和错误肯定率均比阔叶树种的要高,而错误否定率比后者低,说明模型对针叶树种的拟合程度要优于对阔叶树种的拟合程度。在此基础上,预测了8个树种在两种气候变化方案下100a后的分布图。结果表明,在HADCM2SUL方案下,兴安落叶松、白桦、冷杉和云杉的覆盖率分别下降91.2%、67.4%、11.9%、10%;长白落叶松、红松和蒙古栎的覆盖率分别增长87.8%5、4.6%、31.3%;在CGCM1方案下,兴安落叶松、白桦、云杉、冷杉和红松的覆盖率分别下降99.2%8、9.9%、85.9%、83.2%、4.9%;长白落叶松、蒙古栎的覆盖率分别增长93.3%、27.5%;山杨在这两种方案下数量不变。

酸沉降环境化学与硫同位素示踪研究──以浙江中部地区为例

研究区域降水样品pH值的分布范围为3.64-7.20，pH年均值为4.45。SO4、NO3、NH4、Ca、H是降水中主要的阴、阳离子。降水中SO4对降水酸度的贡献逐渐降低，而NO3的贡献则显著增加。SO4、NH4、Ca、H、NO3的沉降通量相对较大，其它离子则相对较小，同时降水离子成分沉降通量的季节变化非常明显。SO4和NO3、Ca和Mg以及Na和Cl表现出较好的相关关系，另外Ca和SO4、Mg和SO4以及Mg和NO3等酸、碱性离子之间也存在较好的相关性，但H与其它离子间并没有表现出明显的相关关系。降水中SO4、NH4、NO3和F主要来自人为活动的影响，Ca、k和Mg主要来自土壤、沙尘等地壳来源，Na、Cl属于典型的海盐性成分。 浙江中部地区大气降水硫同位素δ34S值的变化范围为+0.53‰－+14.23‰，平均值+5.04‰，区域内各地大气降水硫同位素组成基本一致。大气SO2的δ34S值变化范围在+0.95‰－+7.50‰之间，年均值为+4.73‰，气溶胶δ34S值变化范围则在+6.39‰－+9.83‰之间，年均值为+8.09‰。降水和大气SO2的δ34S值存在冬季高夏季低的季节性变化特征，同位素平衡分馏引起的温度效应和夏季生物成因硫的大量释放是造成季节性变化的主要控制因素。降水中人为来源硫的相对贡献约为53%－91%，年平均为73%，生物成因硫的相对贡献约为8%－44%，年平均为26%。远距离传输硫是研究区域降水中另一个非常重要的硫源，其相对贡献约为27%－44%。大气SO2氧化反应中多相氧化处于相对重要的地位，均相氧化在氧化反应机制中也有其不可低估的作用。研究区域大气环境的相对湿度对大气SO2的氧化机制有着重要的影响。

Las familias "Baeomycetaceae" e I"Icmadophilaceae" en la Península Ibérica

Se aportan datos morfológicos, químicos y de distribución de seis especies de las familias Baeomycetaceae (Baeomyces) e Icmadophilaceae (Dibaeis, Icmadophila, Thamnolia) presentes en la Península Ibérica. Se publican numerosas nuevas citas de Baeomyces rufus y de Dibaeis baeomyces, que constituyen las especies más frecuentes y abundantes en la península.

Studies on the Development and Control of Desiccation cracks in compacted clay liner soils

The present study aimed at critically looking at the current practice of the installation of compacted clay liner using bentonite enhanced sand (BES). The application of bentonite is currently the most accepted practice for lining purposes. The ideal bentonite sand combination, which satisfies the liner requirements is 20% bentonite and 80% sand, was selected as one of the liner materials for the investigation of development of desiccation cracks. Locally available sundried marine clay and its combination with bentonite were also included in the study. The desiccation tests on liner materials were conducted for wet/dry cycles to simulate the seasonal variations. Digital image processing techniques were used to measure the crack intensity factor (CIF), a useful and effective parameter for quantification of desiccation cracking. The repeatability of the tests could be well established, as the variation in CIF values of identical samples had a very narrow range of 0 to 2%. The studies on the development of desiccation cracks showed that the CIF of bentonite enhanced sand mixture (BES) was 18.09%, 39.75% and 21.22% for the first, second and third cycles respectively, while it was only 9.83%, 7.52% and 4.58% respectively for sun dried marine clay (SMC). Thus the locally available, alternate liner material suggested, viz SMC, is far superior to BES, when subjected to alternate wet/dry cycles. Further, the improvement of these liner materials when amended with randomly distributed fibre reinforcements was also investigated. Three types of fibres ,namely nylon fibre, polypropylene monofilament and polypropylene fibre mesh were used for the study of fibre amended BES and SMC.The influence of these amendments on the properties of the above liner materials is also studied. The results showed that there is definite improvement in the properties of the liner materials when it is reinforced with discrete random fibres. The study also proved that the desiccation cracks could be controlled with the help of fibre reinforcement.

Els Certàmens literaris a Barcelona, segles XIV-XVIII

Repàs de la història dels certàmens literaris a Barcelona fins a l’entrada de l’època contemporània, des del s. XIV fins al XVIII

Valor predictivo del índice de severidad para gangrena de fournier en el Hospital Universitario de la Samaritana

La GF es una infección fulminante, afecta cualquier edad y género. Se ha descrito el índice de severidad de gangrena de Fournier (ISGF), el cual es útil para evaluar el pronóstico de estos pacientes. OBJETIVO. Reportar nuestra experiencia con esta patología en los últimos 12 años y evaluar el valor predictivo del ISGF de manera retrospectiva. METODOS Se analizaron las historias clínicas de los pacientes con GF de los últimos 12 años en el HUS. Se determinaron los factores asociados a mortalidad y se realizó un análisis de calibración y discriminación del ISGF. RESULTADOS Se recolectaron 40 pacientes todos del género masculino con una edad promedio de 60.3 años (+ /– 14.9). La comorbilidad y causa más frecuente fueron hipertensión arterial y causas urológicas. El patógeno más frecuente fue E. coli. El porcentaje mortalidad en nuestra población fue del 15%. El promedio de ISGF y ISGF ajustado fue: 4.9 y 9.83 ; 9.83 y 4.91 para los fallecidos y los no fallecidos respectivamente, existiendo una diferencia estadísticamente significativa para los dos. (p < 0,05). En el análisis de correlación, discriminación y concordancia, el ISGF sobreestima mortalidad y en ISGF ajustado subestima mortalidad, pero tiene una buena correlación con mortalidad DISCUSIÓN: En nuestro hospital, la GF es una patología poco frecuente; a pesar de esto, se cuenta con un diagnóstico rápido y a su vez un manejo inmediato. Hasta el momento la conducta quirúrgica inmediata y el pronto inicio de antibioticoterapia continúan siendo la mejor opción terapéutica. Existe una relación entre el índice de severidad y la sobrevida de los pacientes, lo cual puede convertirlo en un parámetro útil en la evaluación de estos pacientes. Sin embargo se necesitan estudios prospectivos para validar la escala en nuestra población