活性炭在过氧化氢氧化脱除二苯并噻吩中的催化作用

研究了几种活性炭在过氧化氢氧化二苯并噻吩(DBT)中的催化性能、氧化脱除机理以及碳表面化学对催化性能的影响。考察了活性炭的吸附性能与催化性能以及两者之间的关系、DBT在活性炭上的动态反应活性以及水相pH对其吸附性能和催化性能的影响;并将一种木质活性炭经过3种表面处理,研究了活性炭的表面化学对其催化性能的影响。结果表明:活性炭在过氧化氢氧化DBT中具有较高的催化活性,正辛烷中的DBT转化率可达到81%以上;木质粉末活性炭对DBT的吸附性能优于果壳炭和煤质颗粒活性炭;吸附容量大的活性炭,其催化性能也好;DBT在催化性能高的活性炭作用下的动态反应活性也高;水相pH在低于2的条件下有利于DBT在活性炭上的吸附和催化氧化。DBT的氧化脱除强烈依赖于表面羰基量,是由于表面羰基能加速过氧化氢产生自由基。     

Effect of Surface Modification for Carbon Cathode Materials on Charge–Discharge Performance of Li-Air Batteries

Li-air batteries have attracted considerable attention as rechargeable secondary batteries with a high theoretical energy density of 11,400 kWh/g. However, the commercial application of Li-air batteries is hindered by issues such as low energy efficiency and a short lifetime (cycle numbers). To overcome these issues, it is important to select appropriate cathode materials that facilitate high battery performance. Carbon materials are expected to be ideal materials for cathodes due to their high electrical conductivity and porosity. The physicochemical properties of carbon materials are known to affect the performance of Li-air batteries because the redox reaction of oxygen, which is an important reaction for determining the performance of Li-air batteries, occurs on the carbon materials. In this study, we evaluated the effect of the surface modification of carbon cathode materials on the charge–discharge performance of Li-air batteries using commercial Ketjenblack (KB) and KB subjected to vacuum ultraviolet (VUV) irradiation as cathodes. The surface wettability of KB changed from hydrophobic to hydrophilic as a result of the VUV irradiation. The ratio of COOH and OH groups on the KB surface increased after VUV irradiation. Raman spectra demonstrated that no structural change in the KB before and after VUV irradiation was observed. The charge and discharge capacities of a Li-air battery using VUV-irradiated KB as the cathode decreased compared to original KB, whereas the cycling performance of the Li-air battery improved considerably. The sizes and shapes of the discharge products formed on the cathodes changed considerably due to the VUV irradiation. The difference in the cycling performance of the Li-air battery was discussed from the viewpoint of the chemical properties of KB and VUV-irradiated KB.     

化学气相淀积反应器中超细粒子的形态控制 Ⅲ.TiO_2超细粒子晶体组成

在超细粒子粒度及粒度分布控制模型的基础上,对快相变速率和慢相变速率两种晶型转变情形,建立了化学气相淀积合成超细粒子过程中,表征超细粒子晶体组成及含量的物理模型和数学模型。利用该模型探讨了物系参数和操作参数对超细粒子晶体组成的影响,理论预测和实验结果相一致。     

蝙蝠蛾拟青霉菌丝体的研究现状

  目的  探讨蝙蝠蛾拟青霉复合胶囊对四氯化碳与酒精所致小鼠急性肝损伤的保护作用。  方法  分别采用四氯化碳和酒精灌胃诱导小鼠急性肝损伤模型,测定四氯化碳急性肝损伤模型小鼠血清中丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）的含量及酒精急性肝损伤模型小鼠肝组织中丙二醛（MDA）、甘油三酯（TG）、还原型谷胱甘肽（GSH）的含量并观察2组肝组织切片病理形态学变化。  结果  蝙蝠蛾拟青霉复合胶囊675、2 025 mg/kg BW 剂量组四氯化碳急性肝损伤小鼠血清的ALT、AST含量均低于模型对照组,差异具有统计学意义（P < 0.05）。急性酒精性肝损伤模型中,675、2 025 mg/kg BW剂量组的MDA含量和3个剂量组的TG含量明显低于模型对照组,675、2 025 mg/kg BW剂量组的GSH含量明显高于模型对照组,差异均具有显著性（P < 0.05）。小鼠肝组织形态学结果表明,四氯化碳肝损伤模型肝组织中、高剂量组的肝脏细胞坏死程度与模型对照组比较积分显著下降,差异具有显著性（P < 0.05）,各剂量组气球样变积分和高剂量组水样变程度积分也较模型组有显著性降低（P < 0.01）;蝙蝠蛾拟青霉复合胶囊能显著改善急性酒精性肝损伤小鼠肝细胞脂肪变性程度,差异具有显著性（P < 0.05）。  结论  蝙蝠蛾拟青霉复合胶囊对小鼠急性肝损伤具有较好的辅助保护功能。     

A supercritical fluid-based coating technology. 2: Solubility considerations

Solubility measurements of candidate coating materials have been performed in supercritical (SC) CO₂ so as to select appropriate coating materials for implementation of a solvent-free coating process previously described. Solubility of lipidic compounds such as waxes (paraffin, beeswax, Carnauba wax), pure triglycerides (tricaprin, trimyristin, tripalmitin, tristearin) and mixture of glycerides and fatty acid esters (Gelucire®) in SC CO₂ were evaluated in a static mode under different temperature and pressure conditions, ranging from 13–52°C and from 50–220 bar, whether the CO₂ was in its liquid or SC state. It was shown that the compounds which are mixtures of various components give rise to a selective extraction of the lower melting point components, as evidenced from thermal analysis of soluble and insoluble fractions of the coating materials.     

Pathophysiology and Treatment of Carbon Monoxide Poisoning

Abstract

Carbon monoxide poisoning is the leading cause of poisoning deaths in the US, and published reports of carbon monoxide related morbidity and mortality can vary widely. Common morbidity involves myocardial and/or neurologic injury including delayed neurologic sequelae. The pathophysiology of this entity is complex, involving hypoxic stress on the basis of interference with oxygen transport to the cells and possibly impairing electron transport. Carbon monoxide can also affect leukocytes, platelets and the endothelium, inducing a cascade of effects resulting in oxidative injury. Carboxyhemoglobin levels are valuable for confirming carbon monoxide exposure but cannot be used to stratify severity of poisoning, predict prognosis, or indicate a specific treatment plan. Oxygen therapy is the key treatment of carbon monoxide intoxication, and hyperbaric oxygen has been shown to interdict and improve clinical outcome in some patients. Immediate treatment with a high fraction of inspired oxygen and careful clinical evaluation are mandatory. Timely referral for hyperbaric oxygen is indicated for patients with any history of unconsciousness, cardiovascular instability or ischemia, and persistent mental and/or neurologic deficits. Hyperbaric oxygen should also be considered in certain other patient subsets.     

Confirmation of correct tracheal tube placement in newborn infants

Tracheal intubation remains a common procedure during neonatal intensive care. Rapid confirmation of correct tube placement is important because tube malposition is associated with serious adverse outcomes. The current gold standard test to confirm tube position is a chest radiograph, however this is often delayed until after ventilation has commenced. Hence, point of care methods to confirm correct tube placement have been developed. The aim of this article is to review the available literature on tube placement in newborn infants. We reviewed books, resuscitation manuals and articles from 1830 to the present with the search terms “Infant, Newborn”, “Endotracheal intubation”, “Resuscitation”, “Clinical signs”, “Radiography”, “Respiratory Function Tests”, “Laryngoscopy”, “Ultrasonography”, and “Bronchoscopy”. Various techniques have been studied to help clinicians assess tube placement. However, despite 85 years of clinical practice, the search for higher success rates and quicker intubation continues. Currently, chest radiography remains the gold standard test to confirm tube position. However, rigorous evaluation of new techniques is required to ensure the safety of newborn infants.     

Cutaneous blisters and carbon monoxide poisoning

We present the cases of three patients with skin blisters following carbon monoxide (CO) poisoning. Their blisters appeared to be related to the severity of the poisoning (HbCO levels of more than 40%). Two of the three patients died despite aggressive initial 100% surface oxygen followed by hyperbaric oxygen therapy. The pathophysiology of this type of blister remains unresolved. It could result from pressure necrosis alone or from a combination of pressure necrosis and direct CO inhibition of tissue oxidative enzymes. Although skin involvement as a result of CO poisoning is less frequently reported today than in the past (perhaps because of misidentified burns or because of more aggressive resuscitation and treatment protocols), the physician should recognize that such blisters may signal severe CO poisoning.