Shanghai Santana cars had produced a total of 270,000 cars by the end of 1993, and undergone SKD, CKD and localization stages. The car industry will soon become a pillar industry in Shanghai. During its development, t...Shanghai Santana cars had produced a total of 270,000 cars by the end of 1993, and undergone SKD, CKD and localization stages. The car industry will soon become a pillar industry in Shanghai. During its development, the Shanghai car industry has always given special attention to localization, thus the localization rate of car parts and components has increased year by year. In 1988, Shanghai Santanacars produced 15,000 units, with 13,08 percent of展开更多
[Objectives] To analyze and compare the difference in volatile components of different cultivars and different parts of Artemisia argyi by using headspace solid phase microextraction( HS-SPME) and provide scientific b...[Objectives] To analyze and compare the difference in volatile components of different cultivars and different parts of Artemisia argyi by using headspace solid phase microextraction( HS-SPME) and provide scientific basis for comprehensive development and rational utilization of Artemisia argyi. [Methods]Firstly,HS-SPME was used to extract the volatile components from the leaves,seeds,and stems of seven-tip Artemisia argyi,five-tip Artemisia argyi,and golden Artemisia argyi. Their chemical composition was analyzed by gas chromatographymass spectrometry( GC-MS),and the relative mass fraction of each component was determined by area normalization method. [Results] For the same variety of Artemisia argyi,the content of volatile components in leaves was higher than in seeds and stems except camphor,and the content of volatile components in seven-tip Artemisia argyi leaves was higher than in five-tip Artemisia argyi and golden Artemisia argyi leaves.HS-SPME-GC-MS analysis showed that eucalyptol,camphor,thujone,α-pinene,1-caryophyllene and caryophyllene oxide with higher content were detected in different parts of the different cultivars of Artemisia argyi. [Conclusions]Seven-tip Artemisia argyi leaves were the best medicinal parts of the three cultivars,followed by seven-tip Artemisia argyi seeds.展开更多
This paper presents a mathematical model for components/parts unification (CPU) policy. This model considers two components/parts that are functionally interchangeable but purchased from suppliers with different price...This paper presents a mathematical model for components/parts unification (CPU) policy. This model considers two components/parts that are functionally interchangeable but purchased from suppliers with different prices and quality characteristics. Because of the buyer's quality preference and suppliers' discount rates for bulky purchases, the model assists the procurement manager to determine how best to purchase the components/parts to meet its demand while minimizing the total acquisition costs.展开更多
[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japon...[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japonica Houtt. were analyzed by the headspace solid-phase microextraction( HS-SPME) combined with GC-MS,and the relative percentage of each component was determined by peak area normalization. [Results] Thirty kinds of volatile components were identified from the leaves and rhizomes of P. japonica Houtt.,mainly including olefins,aromatic hydrocarbons,alkanes and esters. [Conclusions] The volatile components in different parts of P. japonica Houtt. were different,and there may be difference in the medicinal value of volatile components in different parts,thus it is required to take an overall consideration of these differences in the development and utilization of P. japonica Houtt.展开更多
Pulp capping is one of the solving for keeping vital pulp in the case of dentin caries,reversible pulpitis or traumatic pulp exposure.The presence of bacteria on the cavity walls or in the pulp was the major factor th...Pulp capping is one of the solving for keeping vital pulp in the case of dentin caries,reversible pulpitis or traumatic pulp exposure.The presence of bacteria on the cavity walls or in the pulp was the major factor that leads to the failure of pulp capping.Traditional pulp capping agent,calcium hydroxide,may not prevent microleakage.Selfetching system is a newly developed adhesive system,which could provide less microleakage and would not break down or dissolve,preventing the oral fluids and bacteria from the pulp along the cavity wall.This may reduce such clinical problems as postoperative sensitivity,secondary caries and marginal discoloration.Researches showed that some kinds of self-etching adhesives induced the mild to moderate inflammatory pulp response,with negative bacterial staining.Inclusion of antibacterial components into self-etching system,such as 12-methacryloyloxydodecylpyridinium bromide(MDPB)may inhibit bacteria and provide better clinical effects.It is speculated that using the self-etching adhesive system containing the antibacterial agent,such as MDPB,to the dental pulp directly or indirectly,may inhibit bacteria after the placement of restoration as well as residual bacteria in the cavity.展开更多
文摘Shanghai Santana cars had produced a total of 270,000 cars by the end of 1993, and undergone SKD, CKD and localization stages. The car industry will soon become a pillar industry in Shanghai. During its development, the Shanghai car industry has always given special attention to localization, thus the localization rate of car parts and components has increased year by year. In 1988, Shanghai Santanacars produced 15,000 units, with 13,08 percent of
基金Supported by Natural Science Foundation of Hubei Province(2004AB242)
文摘[Objectives] To analyze and compare the difference in volatile components of different cultivars and different parts of Artemisia argyi by using headspace solid phase microextraction( HS-SPME) and provide scientific basis for comprehensive development and rational utilization of Artemisia argyi. [Methods]Firstly,HS-SPME was used to extract the volatile components from the leaves,seeds,and stems of seven-tip Artemisia argyi,five-tip Artemisia argyi,and golden Artemisia argyi. Their chemical composition was analyzed by gas chromatographymass spectrometry( GC-MS),and the relative mass fraction of each component was determined by area normalization method. [Results] For the same variety of Artemisia argyi,the content of volatile components in leaves was higher than in seeds and stems except camphor,and the content of volatile components in seven-tip Artemisia argyi leaves was higher than in five-tip Artemisia argyi and golden Artemisia argyi leaves.HS-SPME-GC-MS analysis showed that eucalyptol,camphor,thujone,α-pinene,1-caryophyllene and caryophyllene oxide with higher content were detected in different parts of the different cultivars of Artemisia argyi. [Conclusions]Seven-tip Artemisia argyi leaves were the best medicinal parts of the three cultivars,followed by seven-tip Artemisia argyi seeds.
文摘This paper presents a mathematical model for components/parts unification (CPU) policy. This model considers two components/parts that are functionally interchangeable but purchased from suppliers with different prices and quality characteristics. Because of the buyer's quality preference and suppliers' discount rates for bulky purchases, the model assists the procurement manager to determine how best to purchase the components/parts to meet its demand while minimizing the total acquisition costs.
文摘[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japonica Houtt. were analyzed by the headspace solid-phase microextraction( HS-SPME) combined with GC-MS,and the relative percentage of each component was determined by peak area normalization. [Results] Thirty kinds of volatile components were identified from the leaves and rhizomes of P. japonica Houtt.,mainly including olefins,aromatic hydrocarbons,alkanes and esters. [Conclusions] The volatile components in different parts of P. japonica Houtt. were different,and there may be difference in the medicinal value of volatile components in different parts,thus it is required to take an overall consideration of these differences in the development and utilization of P. japonica Houtt.
文摘Pulp capping is one of the solving for keeping vital pulp in the case of dentin caries,reversible pulpitis or traumatic pulp exposure.The presence of bacteria on the cavity walls or in the pulp was the major factor that leads to the failure of pulp capping.Traditional pulp capping agent,calcium hydroxide,may not prevent microleakage.Selfetching system is a newly developed adhesive system,which could provide less microleakage and would not break down or dissolve,preventing the oral fluids and bacteria from the pulp along the cavity wall.This may reduce such clinical problems as postoperative sensitivity,secondary caries and marginal discoloration.Researches showed that some kinds of self-etching adhesives induced the mild to moderate inflammatory pulp response,with negative bacterial staining.Inclusion of antibacterial components into self-etching system,such as 12-methacryloyloxydodecylpyridinium bromide(MDPB)may inhibit bacteria and provide better clinical effects.It is speculated that using the self-etching adhesive system containing the antibacterial agent,such as MDPB,to the dental pulp directly or indirectly,may inhibit bacteria after the placement of restoration as well as residual bacteria in the cavity.
文摘粪肠球菌是难治性根尖周炎(refractory apical periodontitis,RAP)的主要致病菌,该细菌可耐受严苛环境,引发根尖周免疫炎症反应,造成根管内外持续性感染。粪肠球菌黏附于根管牙本质壁形成生物膜,其耐药和抗冲刷能力显著增强,是介导其致病的关键因素。粪肠球菌与牙本质的黏附包括非特异性和特异性黏附,后者由黏附相关毒力因子介导,主要包括肠球菌胶原结合蛋白(adhesin of collagen from enterococci,Ace)、表面蛋白(extracellular surface protein,Esp)、明胶酶(gelatinase,GelE)和丝氨酸蛋白酶(serine prtease,SprE)、菌毛以及聚集物质,且受到多个双组份系统调控。Fsr双组份系统在群体密度增加时可以促进gelE及sprE的表达,GelE进一步减少表面肠球菌胶原结合蛋白Ace,而GrvRS双组份系统则在响应血清环境时直接下调ace的表达。CroRS双组份系统及WalRK双组份系统也可能分别促进和抑制包括ace及gelE在内的多种毒力因子的表达,进而影响粪肠球菌的黏附性。此外,根管机械/化学预备、根管内环境因素等均可对粪肠球菌牙本质黏附产生影响。根管治疗中避免粪肠球菌的引入和使用干扰黏附的药物可以有效预防粪肠球菌的黏附,而多种活化荡洗方法也可以有效增加根管内粪肠球菌的清除率。针对粪肠球菌牙本质黏附关键因子与调控因素为靶点设计合理药物,有望为根管感染控制提供新的思路与手段。本文就粪肠球菌与牙本质的黏附性及其影响因素进行综述。
