The mechanism and kinetics of electrocatalytic oxidation of formic acid at Pt electrodes is discussed in detail based on previous electrochemical in-situ ATR-FTIRS data [Langmuir 22, 10399 （2006）and Angewa. Chem. In...The mechanism and kinetics of electrocatalytic oxidation of formic acid at Pt electrodes is discussed in detail based on previous electrochemical in-situ ATR-FTIRS data [Langmuir 22, 10399 （2006）and Angewa. Chem. Int. Ed. 50, 1159 （2011）]. A kinetic model with formic acid adsorption （and probably the simultaneous C-H bond activation） as the rate determining step, which contributes to the majority of reaction current for formic acid oxi- dation, was proposed for the direct pathway. The model simulates well the IR spectroscopic results obtained under conditions where the poisoning effect of carbon monoxide （CO） is negligible and formic acid concentration is below 0.1 mol/L. The kinetic simulation predicts that in the direct pathway formic acid oxidation probably only needs one Pt atom as active site, formate is the site blocking species instead of being the active intermediate. We review in detail the conclusion that formate pathway （with either 1st or 2nd order reaction kinetics） is the direct pathway, possible origins for the discrepancies are pointed out.展开更多
AIM： To study the expression of Sonic hedgehog pathway-related molecules, Sonic hedgehog （Shh） and Glil in gastric carcinoma. METHODS： Expression of Shh in 56 gastric specimens including non-cancerous gastric tiss...AIM： To study the expression of Sonic hedgehog pathway-related molecules, Sonic hedgehog （Shh） and Glil in gastric carcinoma. METHODS： Expression of Shh in 56 gastric specimens including non-cancerous gastric tissues, gastric adenocarcinoma, gastric squamous cell carcinoma was detected by RT-PCR, in situ hybridization and immunohistochemistry. Expression of Glil was observed by in situ hybridization. RESULTS： The positive rate of Shh and Glil expression was 0.0%, 0.0% in non-cancerous gastric tissues while it was 66.7%, 57.8% respectively in gastric adenocarcinoma, and 100%, 100% respectively in gastric squamous cell carcinoma. There was a significant difference between the non-cancerous gastric tissues and gastric carcinoma （P 〈 0.05）. Elevated expression of Shh and Glil in gastric tubular adenocarcinoma was associated with poorly differentiated tumors while the expression was absent in gastric mucinous adenocarcinoma. CONCLUSION： The elevated expression of Shh and Glil in gastric adenocarcinoma and gastric squamous cell carcinoma shows the involvement of activated Shh signaling in the cellular proliferation of gastric carcinogenesis. It suggests Shh signaling gene may be a new and good target gene for gastric tumor diagnosis and therapy.展开更多
Nursing education in the United States began in the 1870s with hospital training schools modeled after the Nightingale plan. Presently there are three educational paths that students may take to become a registered nu...Nursing education in the United States began in the 1870s with hospital training schools modeled after the Nightingale plan. Presently there are three educational paths that students may take to become a registered nurse （RN）. These are the baccalaureate degree （BS）, the associate degree （AD） and the diploma. Accelerated nursing programs are also available for people who have a baccalaureate degree in another field. Nursing education and nursing practice in the United States is regulated by each of the 50 states. The focus of nursing education is the preparation of nurses who use critical thinking skills to provide comprehensive patient-centered care to a variety of clients. It is expected that nurses will function using evidence-based practice in a culturally competent, safe manner. Nursing schools must be approved by the state in which they exist. In addition to this, most nursing schools are also accredited, a voluntary process that is done by a non-governmental association. All graduates take the same licensing exam, a computer adaptive test that is from 75 to 265 items long educated graduates were first time test takers; 85.5% passed the exam. Trends in nursing education In 2008 almost 120,000 US include a focus on evidence based practice, an emphasis on safety and quality, patient education and management of chronic conditions, genetics and genomics and the use of simulation in nursing education展开更多
The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed...The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0.6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl)-2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-(hydroxylmethyl)propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.展开更多
The infection of the central nervous system （CNS） by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis （NS） is one of the most severe presentations of schistosome infe...The infection of the central nervous system （CNS） by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis （NS） is one of the most severe presentations of schistosome infection. Among the NS symptoms, cerebral invasion is mostly caused by Schistosoma japonicum （S. japonicum）, and the spinal cord symptoms are mainly caused by S. mansoni or S. haematobium. There are 2 main pathways by which schistosomes cause NS： egg embolism and worm migration, via either artery or vein system, especially the valveless perivertebral Batson＇s plexus. The adult worm migrates anomalously through the above pathways to the CNS where they lay eggs. Due to the differences in species of schistosomes and stages of infection, mechanisms vary greatly. The portal hypertension with hepatosplenic schistosomiasis also plays an important role in the pathogenesis. Here the pathways through which NS occurs in the CNS were reviewed.展开更多
基金This work was supported by one hundred Tal- ents＇ Program of the Chinese Academy of Science, the National Natural Science Foundation of China （No.21273215）, 973 program from the Ministry of Sci- ence and Technology of China （No.2010CB923302）.
文摘The mechanism and kinetics of electrocatalytic oxidation of formic acid at Pt electrodes is discussed in detail based on previous electrochemical in-situ ATR-FTIRS data [Langmuir 22, 10399 （2006）and Angewa. Chem. Int. Ed. 50, 1159 （2011）]. A kinetic model with formic acid adsorption （and probably the simultaneous C-H bond activation） as the rate determining step, which contributes to the majority of reaction current for formic acid oxi- dation, was proposed for the direct pathway. The model simulates well the IR spectroscopic results obtained under conditions where the poisoning effect of carbon monoxide （CO） is negligible and formic acid concentration is below 0.1 mol/L. The kinetic simulation predicts that in the direct pathway formic acid oxidation probably only needs one Pt atom as active site, formate is the site blocking species instead of being the active intermediate. We review in detail the conclusion that formate pathway （with either 1st or 2nd order reaction kinetics） is the direct pathway, possible origins for the discrepancies are pointed out.
基金Supported by the Foundation of Shandong Province Bureau of Health, No. 2005JZ001
文摘AIM： To study the expression of Sonic hedgehog pathway-related molecules, Sonic hedgehog （Shh） and Glil in gastric carcinoma. METHODS： Expression of Shh in 56 gastric specimens including non-cancerous gastric tissues, gastric adenocarcinoma, gastric squamous cell carcinoma was detected by RT-PCR, in situ hybridization and immunohistochemistry. Expression of Glil was observed by in situ hybridization. RESULTS： The positive rate of Shh and Glil expression was 0.0%, 0.0% in non-cancerous gastric tissues while it was 66.7%, 57.8% respectively in gastric adenocarcinoma, and 100%, 100% respectively in gastric squamous cell carcinoma. There was a significant difference between the non-cancerous gastric tissues and gastric carcinoma （P 〈 0.05）. Elevated expression of Shh and Glil in gastric tubular adenocarcinoma was associated with poorly differentiated tumors while the expression was absent in gastric mucinous adenocarcinoma. CONCLUSION： The elevated expression of Shh and Glil in gastric adenocarcinoma and gastric squamous cell carcinoma shows the involvement of activated Shh signaling in the cellular proliferation of gastric carcinogenesis. It suggests Shh signaling gene may be a new and good target gene for gastric tumor diagnosis and therapy.
文摘Nursing education in the United States began in the 1870s with hospital training schools modeled after the Nightingale plan. Presently there are three educational paths that students may take to become a registered nurse （RN）. These are the baccalaureate degree （BS）, the associate degree （AD） and the diploma. Accelerated nursing programs are also available for people who have a baccalaureate degree in another field. Nursing education and nursing practice in the United States is regulated by each of the 50 states. The focus of nursing education is the preparation of nurses who use critical thinking skills to provide comprehensive patient-centered care to a variety of clients. It is expected that nurses will function using evidence-based practice in a culturally competent, safe manner. Nursing schools must be approved by the state in which they exist. In addition to this, most nursing schools are also accredited, a voluntary process that is done by a non-governmental association. All graduates take the same licensing exam, a computer adaptive test that is from 75 to 265 items long educated graduates were first time test takers; 85.5% passed the exam. Trends in nursing education In 2008 almost 120,000 US include a focus on evidence based practice, an emphasis on safety and quality, patient education and management of chronic conditions, genetics and genomics and the use of simulation in nursing education
基金Sponsored by the National Natural Science Foundation of China(Grant No.50378028)
文摘The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0.6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl)-2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-(hydroxylmethyl)propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.
基金supported by the Science Foundation of the Department of Health, Hubei Province, China (No. XF06D43, XF2008-23)
文摘The infection of the central nervous system （CNS） by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis （NS） is one of the most severe presentations of schistosome infection. Among the NS symptoms, cerebral invasion is mostly caused by Schistosoma japonicum （S. japonicum）, and the spinal cord symptoms are mainly caused by S. mansoni or S. haematobium. There are 2 main pathways by which schistosomes cause NS： egg embolism and worm migration, via either artery or vein system, especially the valveless perivertebral Batson＇s plexus. The adult worm migrates anomalously through the above pathways to the CNS where they lay eggs. Due to the differences in species of schistosomes and stages of infection, mechanisms vary greatly. The portal hypertension with hepatosplenic schistosomiasis also plays an important role in the pathogenesis. Here the pathways through which NS occurs in the CNS were reviewed.
