An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide （NBS） catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent iso...An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide （NBS） catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time （5-20 min）. Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents.展开更多
Systemic hypertension is an established risk factor for coronary artery disease and cerebrovascular accident and control of blood pressure reduces the risk of a major cardiovascular event.Both non-pharmacological and ...Systemic hypertension is an established risk factor for coronary artery disease and cerebrovascular accident and control of blood pressure reduces the risk of a major cardiovascular event.Both non-pharmacological and pharmacological treatment options are available to treat hypertension.Yoga,recently received more attention as a treatment modality for various lifestyle disorders,even though practiced in India since ancient times.In this review,we are analyzing the role of yoga in the treatment of systemic hypertension.展开更多
One unknown impurity （Imp-II） during the analysis of laboratory batches of isoproterenol hydrochloride was detected in the level ranging from 0.04% to 0.12% by high performance liquid chromatography with UV detectio...One unknown impurity （Imp-II） during the analysis of laboratory batches of isoproterenol hydrochloride was detected in the level ranging from 0.04% to 0.12% by high performance liquid chromatography with UV detection. The unknown impurity structure was proposed as 4-[2-（propan-2oylamino）ethyl]benzene-l,2-diol （Imp-II） using the liquid chromatography-mass spectrophotometry （LC-MS） analysis. Imp-II was isolated by semi-preparative liquid chromatography from the impurity-enriched reaction crude sample. Its proposed structure was confirmed by nuclear magnetic spectroscopy such as 1H, 13C, DEPT （1D NMR）, HSQC （2D NMR） and infrared spectroscopy （IR）, and retention time and purity with HPLC followed by the chemical synthesis. Due to less removable nature of Imp-II during the purification, the synthetic process was optimized proficiently to control the formation of Imp-II below to the limit 〈 0.12% in the course of reaction. The new chemical route was developed for the preparation of this impurity in required quantity with purity to use as reference standard. The most probable mechanism for the formation of Imp-II was discussed in details.展开更多
Pantoprazole sodium, a substituted benzimidazole derivative, is an irreversible proton pump inhibitor which is primarily used for the treatment of duodenal ulcers, gastric ulcers, and gastroesophageal reflux disease (...Pantoprazole sodium, a substituted benzimidazole derivative, is an irreversible proton pump inhibitor which is primarily used for the treatment of duodenal ulcers, gastric ulcers, and gastroesophageal reflux disease (GERD). The monographs of European Pharmacopoeia (Ph. Eur.) and United States Pharmacopoeia (USP) specify six impurities, viz.;impurities A, B, C, D, E and F, respectively for its active pharmaceutical ingredient (API). The identification and synthesis of all impurities except impurity E are well described in the literature;however, there is no report related to impurity E. The prospects to the formation and controlling of impurity E up to -0.03% in the synthesis of pantoprazole sodium sesquihydrate (PAN) were discussed in detail for the first time. The present work described the journey towards the successful development of an optimal preparation procedure of dimer impurity E. The most plausible mechanism involved in the formation of impurity E has been proposed.展开更多
为进一步缩小大型机床(尤其是5轴、6轴机床)工作时的公差范围,提升其加工精度,美国国家制造科学中心(NCMS,National Center of Manufacturing Science)组织了一次名为大型机床空间精度研究(VALMT,Volumetric Accuracyfor Large Machine ...为进一步缩小大型机床(尤其是5轴、6轴机床)工作时的公差范围,提升其加工精度,美国国家制造科学中心(NCMS,National Center of Manufacturing Science)组织了一次名为大型机床空间精度研究(VALMT,Volumetric Accuracyfor Large Machine Tools)的大规模联合行动。此次联合行动邀请了包括美国自动精密工程公司(API)、波音公司(Boeing)、西门子(Siemens)、辛辛那提(Mag Cincinnati)等众多行业精英企业参加。大型机床空间误差补偿技术(VEC,Volumetric Error Compensation)由此诞生。展开更多
Wetland means the surface of the earth that is permanently or seasonally or partially covered with water. Wetlands are most productive areas for biodiversity and local livelihood support. Nepal ratified Ramsar convent...Wetland means the surface of the earth that is permanently or seasonally or partially covered with water. Wetlands are most productive areas for biodiversity and local livelihood support. Nepal ratified Ramsar convention in 1987 and started to include the wetland in Ramsar site and till now nine wetland sites are included in Ramsar site. There are still lacking systematic research and conservation approach for these wetlands;therefore, our study attempted to assess the status of wetlands in the Dhorpatan Hunting Reserve, Nepal;and explored threats and conservation challenges. We prepared list of streams and lakes and collected detail information regarding area, district, block, elevation and cultural as well as ecological importance of lakes. We recorded total 11 lakes with total 304477 m2 areas. The Sundaha lake is largest lake of the reserve having significant religious importance. We also recorded 7 streams in the reserve. Wetlands of the reserve were facing problem of sedimentation, pollution, and change in climate has also effects on these wetland ecosystem and their importance.展开更多
A mode of process/thread communication between QNX and WINDOWS operating systems in isomerous computers is described. It is proved in practice to be an entirely feasible mode with high efficiency and reliability. A so...A mode of process/thread communication between QNX and WINDOWS operating systems in isomerous computers is described. It is proved in practice to be an entirely feasible mode with high efficiency and reliability. A socket created by Socket API is used to communicate between two operating systems.展开更多
基金Council of Scientific and Industrial Research(CSIR),New Delhi,Government of India for thefinancial support under major research project(No.01(2391)/10/EMR-II)
文摘An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide （NBS） catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time （5-20 min）. Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents.
文摘Systemic hypertension is an established risk factor for coronary artery disease and cerebrovascular accident and control of blood pressure reduces the risk of a major cardiovascular event.Both non-pharmacological and pharmacological treatment options are available to treat hypertension.Yoga,recently received more attention as a treatment modality for various lifestyle disorders,even though practiced in India since ancient times.In this review,we are analyzing the role of yoga in the treatment of systemic hypertension.
文摘One unknown impurity （Imp-II） during the analysis of laboratory batches of isoproterenol hydrochloride was detected in the level ranging from 0.04% to 0.12% by high performance liquid chromatography with UV detection. The unknown impurity structure was proposed as 4-[2-（propan-2oylamino）ethyl]benzene-l,2-diol （Imp-II） using the liquid chromatography-mass spectrophotometry （LC-MS） analysis. Imp-II was isolated by semi-preparative liquid chromatography from the impurity-enriched reaction crude sample. Its proposed structure was confirmed by nuclear magnetic spectroscopy such as 1H, 13C, DEPT （1D NMR）, HSQC （2D NMR） and infrared spectroscopy （IR）, and retention time and purity with HPLC followed by the chemical synthesis. Due to less removable nature of Imp-II during the purification, the synthetic process was optimized proficiently to control the formation of Imp-II below to the limit 〈 0.12% in the course of reaction. The new chemical route was developed for the preparation of this impurity in required quantity with purity to use as reference standard. The most probable mechanism for the formation of Imp-II was discussed in details.
文摘Pantoprazole sodium, a substituted benzimidazole derivative, is an irreversible proton pump inhibitor which is primarily used for the treatment of duodenal ulcers, gastric ulcers, and gastroesophageal reflux disease (GERD). The monographs of European Pharmacopoeia (Ph. Eur.) and United States Pharmacopoeia (USP) specify six impurities, viz.;impurities A, B, C, D, E and F, respectively for its active pharmaceutical ingredient (API). The identification and synthesis of all impurities except impurity E are well described in the literature;however, there is no report related to impurity E. The prospects to the formation and controlling of impurity E up to -0.03% in the synthesis of pantoprazole sodium sesquihydrate (PAN) were discussed in detail for the first time. The present work described the journey towards the successful development of an optimal preparation procedure of dimer impurity E. The most plausible mechanism involved in the formation of impurity E has been proposed.
文摘为进一步缩小大型机床(尤其是5轴、6轴机床)工作时的公差范围,提升其加工精度,美国国家制造科学中心(NCMS,National Center of Manufacturing Science)组织了一次名为大型机床空间精度研究(VALMT,Volumetric Accuracyfor Large Machine Tools)的大规模联合行动。此次联合行动邀请了包括美国自动精密工程公司(API)、波音公司(Boeing)、西门子(Siemens)、辛辛那提(Mag Cincinnati)等众多行业精英企业参加。大型机床空间误差补偿技术(VEC,Volumetric Error Compensation)由此诞生。
文摘Wetland means the surface of the earth that is permanently or seasonally or partially covered with water. Wetlands are most productive areas for biodiversity and local livelihood support. Nepal ratified Ramsar convention in 1987 and started to include the wetland in Ramsar site and till now nine wetland sites are included in Ramsar site. There are still lacking systematic research and conservation approach for these wetlands;therefore, our study attempted to assess the status of wetlands in the Dhorpatan Hunting Reserve, Nepal;and explored threats and conservation challenges. We prepared list of streams and lakes and collected detail information regarding area, district, block, elevation and cultural as well as ecological importance of lakes. We recorded total 11 lakes with total 304477 m2 areas. The Sundaha lake is largest lake of the reserve having significant religious importance. We also recorded 7 streams in the reserve. Wetlands of the reserve were facing problem of sedimentation, pollution, and change in climate has also effects on these wetland ecosystem and their importance.
基金The project supported by the National Meg-science Engineering project of the Chinese Government
文摘A mode of process/thread communication between QNX and WINDOWS operating systems in isomerous computers is described. It is proved in practice to be an entirely feasible mode with high efficiency and reliability. A socket created by Socket API is used to communicate between two operating systems.
