Toxicants inhibiting anaerobic digestion: A review

Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion.     

无左室肥厚的非杓型高血压患者血清GDF-15、YKL-40水平表达及其临床意义

摘要 目的：探讨无左室肥厚（NLVH）的非杓型高血压患者血清生长分化因子15（GDF-15）、人软骨糖蛋白39（YKL-40）水平的表达及其临床意义。方法：选取2019年6月至2020年6月张家口学院附属人民医院收治的NLVH原发性高血压患者104例为研究对象,根据夜间收缩压下降率（SBPF）将其分为非杓型组（SBPF＜10%,n=60）和杓型组（10%≤SBPF≤20%,n=44）。另选取同期于张家口学院附属人民医院进行体检的健康志愿者49例记为对照组。比较三组受试者的血清GDF-15、YKL-40水平,比较非杓型和杓型NLVH患者的舒张压、收缩压、颈动脉内膜中层厚度（IMT）值、僵硬度、紧张度和扩张性、超声心动图参数、血压昼夜节律指标,分析NLVH的非杓型高血压患者血清GDF-15、YKL-40水平与超声心动图参数、血压昼夜节律、颈动脉粥样硬化指标的相关性。采用多元线性逐步回归分析非杓型高血压发病的影响因素。结果：非杓型NLVH组和杓型NLVH组患者的血清GDF-15、YKL-40水平均高于对照组患者,且非杓型NLVH组高于杓型NLVH组（P<0.05）;与杓型NLVH组患者比较,非杓型NLVH组患者的IMT、僵硬度、夜间平均收缩压（nSBP）、平均舒张压（nDBP）、左室舒张末期内径（LVEDD）、左房内径（LAD）、室间隔厚度（LVSD）、左室后壁厚度（PWD）均升高,LVEF、紧张度、扩张性则降低（P<0.05）,但两组患者的白天平均收缩压（dSBP）、白天平均舒张压（dDBP）比较差异无统计学意义（P>0.05）。经Pearson相关性分析显示,NLVH的非杓型高血压患者的血清GDF-15、YKL-40水平与IMT、僵硬度、LAD、LVEDD、LVSD、PWD、nSBP、nDBP呈正相关,与LVEF、紧张度、扩张性呈负相关（P<0.05）,而与dSBP、dDBP无明显相关性（P>0.05）;GDF-15与YKL-40水平呈正相关（P<0.05）。多元线性逐步回归分析显示：颈动脉IMT、僵硬度、LAD、LVEDD、nSBP、nDBP、LVEF、颈动脉紧张度、GDF-15是非杓型高血压发病的独立影响因素（P<0.05）。结论：NLVH的非杓型高血压患者血清GDF-15、YKL-40水平异常升高,且与超声心动图参数、血压昼夜节律、颈动脉粥样硬化具有一定关联,患者发病受多种因素影响,临床工作中应结合相关因素对患者进行适当干预。     

7号淀粉酶链霉菌M1033木糖异构酶基因序列分析

测定了来自海南的7号淀粉酶M1033木糖异构酶(Ⅺ)基困的DNA序列。：该酶的结构基因由l161bp组成,相当于387个氨基酸残基。其GC含量为72．1克分子％,密码子第三位的Gc利用率达98克分子％。在氨基酸序列上,M1033的木糖异构酶与其它放线菌菌株的相比具有较高的同源性;特别是与3种链霉菌菌株的同源性高达90%左右。     

Predicting Treatment Response of Breast Cancer to Neoadjuvant Chemotherapy Using Ultrasound-Guided Diffuse Optical Tomography

PURPOSE: To prospectively investigate ultrasound-guided diffuse optical tomography (US-guided DOT) in predicting breast cancer response to neoadjuvant chemotherapy (NAC). MATERIALS AND METHODS: Eighty-eight breast cancer patients, with a total of 93 lesions, were included in our study. Pre– and post–last chemotherapy, size and total hemoglobin concentration (THC) of each lesion were measured by conventional US and US-guided DOT 1 day before biopsy (time point t0, THC THC0, SIZE S0) and 1 to 2 days before surgery (time point tL, THCL, SL). The relative changes in THC and SIZE of lesions after the first and last NAC cycles were considered as the variables ΔTHC and ΔSIZE. Receiver operating characteristic curve was performed to calculate ΔTHC and ΔSIZE cutoff values to evaluate pathologic response of 93 breast cancers to NAC, which were then prospectively used to predicate response of 61 breast cancers to NAC. RESULTS: The cutoff values of ΔTHC and ΔSIZE for evaluation of breast cancers NAC treatment response were 23.9% and 42.6%. At ΔTHC 23.9%, the predicted treatment response in 61 breast lesions for the time points t1 to t3 was calculated by area under the curve (AUC), which were AUC₁ 0.534 (P = .6668), AUC₂ 0.604 (P = .1893), and AUC₃ 0.674(P =. 0.027), respectively; for ΔSIZE 42.6%, at time points t1 to t3, AUC₁ 0.505 (P = .9121), AUC₂ 0.645 (P = .0115), and AUC₃ 0.719 (P = .0018). CONCLUSION: US-guided DOT ΔTHC 23.9% and US ΔSIZE 42.6% can be used for the response evaluation and earlier prediction of the pathological response after three rounds of chemotherapy.     

24节气内乌鲁木齐10号泉水体细菌群落结构变化

为了解乌鲁木齐10号泉水体细菌群落结构及多样性在24节气内的变化,选取24节气当天采集泉水样品(计24份),利用末端限制性片段长度多态性(T-RFLP)技术对其进行群落结构及多样性分析,并结合该泉地球水文化学指标进行典型相关性分析。结果表明:泉水细菌群落的香农指数(H)变化幅度较大(1.088—3.003),春季(立春至谷雨)样品呈现出明显的波动趋势,并在惊蛰时达到最低值(1.088),夏季(立夏至大暑)和秋季(立秋至霜降)样品在节气内出现类似的递增趋势,冬季(立冬至大寒)样品则保持在较低水平(≈1.761);辛普森指数(D)和均匀度指数(E)在24节气内变化的差异不显著。24节气的泉水细菌群落组成主要有厚壁菌门、拟杆菌门、放线菌门、变形菌门及梭杆菌门,此外,还有少量隶属于蓝藻门、螺旋体门、异常球菌-栖热菌门、绿菌门、柔膜菌门和硝化螺菌门等的类群存在于某些特定的节气中;春夏季节革兰氏阴性菌为优势类群,秋冬季节,革兰氏阳性菌为优势类群;硫氧化菌类群(Acidithiobacillus、Thiothrix)和硫还原菌群落(Desulfobacter、Desulfoluna)的存在,与10号泉的含硫特性相关。通过对各项地球水文化学指标的分析显示,电导率、水汞、甲烷、硫化物在各节气的波动最为剧烈;乌鲁木齐10号泉水体细菌群落组成随24节气更替存在一定变化并与地球水文化学指标相关。     

免耕法对棉田生态系统能流功能的影响

比较了常规与免耕法对棉田生态系统中土壤微生物、害虫、天敌、棉株及其整个棉田生态系统能流功能的影响 .结果表明 ,免耕棉田土壤微生物量与年呼吸耗氧量均明显高于常规棉田 ,分别为常规棉田的 1 .32倍和 1 .63倍 ;免耕棉田的苗蚜与秋蚜、2代与 4代棉铃虫种群生产力下降 ,而伏蚜与 3代棉铃虫种群生产力增加 ;免耕棉田内天敌种群生产力及其捕食利用效率下降 ;免耕可提高棉田系统的光能利用率和总生产力 ,减少辅助能的投入 ,具有低耗、高效的特点 .     

一种植物生长激素-N'-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼的合成、晶体结构和抗菌活性

目的:合成并表征一种属于植物生长激素的席夫碱类化合物.方法:由5-硝基水杨醛和3,5-二羟基苯甲酰肼在甲醇溶液中反应得到N′-(5-硝基-2-羟基苯亚甲基)-3,5-二羟基苯甲酰肼.结果:用单晶X-射线衍射法测得其结构并表征,同时通过抗菌实验证明其在一定浓度下具有明显的抗菌活性.结论:这种席夫碱类化合物在某种程度上具有明显的抗菌活性.     

Developmental profiles of glial enzymes in the chick embryo: In vivo and in culture

The activities of two glial cell enzymes, glutamine synthetase (a marker for astrocytes) and 2′,3′-cyclic nucleotide 3′-phosphohydrolase (a marker for oligodendrocytes and myelination) were studied in the developing chick embryo brain in vivo and in cultures derived from chick embryos. The in vivo findings showed that the activities of both enzymes parallel the patterns of gliogenesis and myelination. Glutamine synthetase follows similar patterns in culture and in vivo, whereas the developmental profile of 2′,3′-cyclic nucleotide 3′-phosphohydrolase appears to be affected by the culture conditions.     

Establishment of a novel method for the identification of fertilization defective mutants in Arabidopsis thaliana

Plant reproduction is an extremely important phenomenon, as it is strongly associated with plant genetics and early development. Additionally, foundations of the reproductive system have direct implications on plant breeding and agriculture. Investigation of the functions of male and female gametophytes is critical since their fusion is required for seed formation. Although a large number of mutants have been generated to understand the functions of male and female gametophytes, only a small number of genes required for plant fertilization have been identified to date. This is because the screening method used previously required the dissection of siliques, and fertilization-specific mutants exhibiting semi-fertility (or ∼50% fertility) were difficult to identify. Here, we report a new efficient screening method for the identification of fertilization defective mutants in Arabidopsis thaliana using vanillin staining. This method is based on the pollen tube-dependent ovule enlargement morphology (POEM) phenomenon, which generates a partial seed coat within the ovule without fertilization. Using this method, we successfully identified 23 putative fertilization defective mutants in Arabidopsis.