首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   94篇
  免费   14篇
  国内免费   4篇
综合类   8篇
化学工业   47篇
金属工艺   1篇
机械仪表   2篇
建筑科学   5篇
能源动力   1篇
轻工业   22篇
石油天然气   4篇
一般工业技术   17篇
冶金工业   2篇
原子能技术   3篇
  2023年   5篇
  2022年   1篇
  2021年   8篇
  2020年   6篇
  2019年   5篇
  2018年   7篇
  2017年   5篇
  2016年   4篇
  2015年   4篇
  2014年   3篇
  2013年   9篇
  2012年   6篇
  2011年   7篇
  2010年   7篇
  2009年   3篇
  2008年   4篇
  2007年   6篇
  2006年   6篇
  2005年   4篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1998年   3篇
  1993年   1篇
排序方式: 共有112条查询结果,搜索用时 31 毫秒
1.
《Ceramics International》2021,47(22):31073-31083
Pluronic 31R1 surfactant and MCM-41 silica were used to fabricate mesoporous Ag2O/g-C3N4 heterostructures with improved surface areas. The fabricated mesoporous nanocomposite was used to photo oxidize ciprofloxacin. The TEM images of Ag2O/g-C3N4 indicated a uniform dispersion of spherical approximately 4-nm Ag2O nanoparticles on g-C3N4. The mesoporous 0.9% Ag2O@g-C3N4 heterostructure exhibited 100% efficiency in ciprofloxacin oxidation within 60 min when compared with the 25% efficiency in 120 min of pure mesoporous Ag2O and 10% efficiency in 120 min of pure g-C3N4. The highest ciprofloxacin oxidation efficiency achieved was 100%, which was four and ten times better than those of Ag2O and g-C3N4, respectively. This superior performance of the mesoporous Ag2O/g-C3N4 was attributed to the high dispersion of nano-sized mesoporous Ag2O particles on the g-C3N4 surface, narrow bandgap, and significantly high surface areas. The powerful interaction between Ag2O and g-C3N4 ensured robust durability of Ag2O/g-C3N4 heterostructures, which is evident in the fact that five recycling trials of the photocatalyst rendered a minimal loss of efficiency.  相似文献   
2.
Objective: The aim was to study the stability of dry powder inhaler (DPI) formulations containing antibiotic with different preparation ways – carrier-based, carrier-free, and novel combined formulation – and thereby to compare their physicochemical and in vitro–in silico aerodynamical properties before and after storage. Presenting a novel combined technology in the field of DPI formulation including the carrier-based and carrier-free methods, it is the most important reason to introduce this stable formulation for the further development of DPIs.

Methods: The structure, the residual solvent content, the interparticle interactions, the particle size distribution and the morphology of the samples were studied. The aerodynamic values were determined based on the cascade impactor in vitro lung model. We tested the in silico behavior of the novel combined formulated samples before and during storage.

Results: The physical measurements showed that the novel combined formulated sample was the most favorable. It was found that thanks to the formulation technique and the use of magnesium stearate (MgSt) has a beneficial effect on the stability compared with the carrier-based formulation without MgSt and carrier-free formulations. The results of in vitro and in silico lung models were consistent with the physical results, so the highest deposition was found for the novel combined formulated sample during the storage.

Conclusions: It can be established that after the storage a novel combined formulated DPI contained amorphous drug to have around 2.5?μm mass median aerodynamic diameter and nearly 50% fine particle fraction predicted high lung deposition in silico also.  相似文献   
3.
本文研究了环丙沙星(CPLX)羧基衍生物及其抗体的制备,并对该衍生物抗体的特异性进行了测定。将环丙沙星与3-溴丙酸反应,生成环丙沙星的羧基衍生物(CPLX-COOH),通过制备液相进行纯化,用红外光谱(IR)、电喷雾电离质谱(ESI-MS)与核磁共振法(NMR)进行鉴定;将环丙沙星衍生物分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)进行偶联,分别制备免疫抗原(CPLX-COOH-BSA)和包被抗原(CPLX-COOH-OVA),并用紫外光谱法进行鉴定。用免疫抗原免疫BALB/c小鼠,制备环丙沙星衍生物多克隆抗体。通过ELISA方阵滴定法,确定包被抗原的最佳包被浓度和抗体最佳稀释度,建立了CPLX-COOH间接竞争ELISA检测方法,其半抑制浓度IC50为228.56 ng/mL,最低检出限(LOD)为25.527 ng/mL,该抗体具有广谱特异性,可与多种氟喹诺酮类药物发生交叉反应,可进行氟喹诺酮类药物残留的多元检测。  相似文献   
4.
The present study analyzed the prevalence and antimicrobial resistance of Salmonella along an integrated broiler chicken supply chain. A total of 172 Salmonella isolates were recovered from 1148 samples collected from four sample sources (breeder farms, broiler farms, abattoir, and retail markets), representing nine production stages. These Salmonella isolates were examined for antimicrobial susceptibility to 12 different antimicrobial agents using a disk diffusion assay. Among them, 168 were identified as six different serotypes of Salmonella enterica. The predominant serotype was S. Enteritidis (n = 116), followed by S. Infantis (n = 18), S. Gueuletapee (n = 16), S. Derby (n = 12), S. Meleagridis (n = 4), and S. London (n = 2). The remaining four isolates were serogroup-untypeable. A majority of the 172 isolates (96.51%) was resistant to one or more antibiotics and 61.05% of the Salmonella isolates showed a multidrug resistance phenotype. Statistical analysis indicated the one risk product stage for Salmonella contamination occurred in the sample source at the abattoir, specifically the stage of Carcasses after chilling. The majority of S. Enteritidis isolates shared the same pulsed-field gel electrophoresis (PFGE) cluster, suggesting that the S. Enteritidis strain might spread along the broiler chicken supply chain. The prevalence and antimicrobial resistance of Salmonella in different production stages suggest the importance of controlling Salmonella in the broiler chicken supply chain for public health, underlying the need for improved measures of reducing carcass contamination in abattoirs and the appropriate use of antimicrobials in broiler flocks.  相似文献   
5.
Nanotechnology is currently employed as a tool to fight more efficiently against human pathogens. Nanoparticles can be prepared from a variety of materials such as protein, biodegradable polymers and synthetic polymers. Tamarindus indica Linn. or tamarind is one of the most important biodegradable polymer. In the present study, chemically modified polymer of tamarind ‘carboxymethyl tamarind kernel polysaccharide’ (CMTKP) is used for the synthesis of nanoparticulate formulation. Antibacterial activity of CMTKP was analysed which was then enhanced by incorporating a flouroquinolone antibiotic, ciprofloxacin to it. Ciprofloxacin-loaded CMTKP nanoparticles were synthesised via ionotropic gelation technique. Nanosuspension so formed was lyophilised by addition of a cryoprotectant. Nanoparticles obtained were characterised for its particle size, morphology and stability. Interaction studies were confirmed by Fourier transform infrared spectroscopy (FT-IR). Antibacterial activities of ciprofloxacin, CMTKP and ciprofloxacin-loaded CMTKP nanoparticles were tested against two Gram negative and positive bacteria. The antibacterial assay results revealed greatest zone of inhibition by ciprofloxacin-loaded CMTKP nanoparticles in Micrococcus luteus. Toxicity analysis of the prepared formulation was carried out on vero cell lines via resazurin assay which revealed its minimum toxicity.  相似文献   
6.
7.
The present study describes the encapsulation of vegetable fats (cocoa butter and mango butter) within chitosan microparticles by double emulsion technique to prevent leaching of the internal apolar phase. Leaching studies suggested negligible leaching of the internal phase (~12–14%) when the fats were encapsulated as compared to the control (~40%). Fourier transform infrared spectroscopy and differential scanning calorimeter studies confirmed the successful encapsulation of fats. The release of drug (ciprofloxacin) from the microparticles was diffusion and erosion mediated and were capable to elicit antimicrobial activity against Escherichia coli. The study suggests that the developed microparticles have the potential for controlled delivery of antimicrobials.  相似文献   
8.
Purpose: The efficacy of aerosolization of ciprofloxacin (CPFX) incorporated into PEGylated liposomes (PEGylated CPFX-liposomes) for the treatment of respiratory infections was evaluated. Method: PEGylated CPFX-liposomes with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-n-[methoxy(polyethylene glycol)-2000] (particle size: 100 nm) were prepared, and the drug distribution characteristics in lung epithelial lining fluid (ELF) following aerosolization of PEGylated CPFX-liposomes were examined in rats. Furthermore, the antibacterial effects of PEGylated CPFX-liposomes in ELF were evaluated by pharmacokinetic/pharmacodynamic analysis. Results: The elimination rate of CPFX from ELF following aerosolization of PEGylated CPFX-liposomes was significantly slower than that of CPFX incorporated into unmodified liposomes (unmodified CPFX-liposomes; particle size: 100 nm). According to pharmacokinetic/pharmacodynamic analysis, the PEGylated CPFX-liposomes exhibited potent antibacterial effects against pathogenic microorganisms in ELF. Conclusion: This study shows that PEGylated CPFX-liposomes are a useful aerosol-based pulmonary drug delivery system for the treatment of respiratory infections.  相似文献   
9.
A facile, safe, and environmentally friendly approach to the preparation of poly(β‐cyclodextrin‐co‐guanidinocitrate) (ZWβCDP) via polymerization of β‐cyclodextrin (β‐CD) in the presence of guanidinocitrate as a novel cross‐linker is reported. Novel zwitterionic guanidinocitrate cross‐linker is synthesized by in situ reaction of melted guanidine and citric acid during polymerization. The structure of achieved hydrogels is characterized by attenuated total reflection‐Fourier‐transform infrared (ATR‐FTIR), X‐ray photoelectron spectroscopy, thermogravimetric analysis, differential thermogravimetric, differential scanning calorimetry (DSC), differential of DSC, and X‐ray diffraction analyses and also by Kjeldahl and colorimetric methods for elemental analyses. The swelling ratio of the anionic β‐CD polymer (ANβCDP) and ZWβCDPs is determined in water and simulated physiological media. Subsequently, the hydrogels/ciprofloxacin (CFX, as a model antibiotic drug) complexes are prepared to improve the thermal stability of CFX and define potential pharmaceutical applications of hydrogels. Solid‐state characterization of hydrogels/CFX complexes is investigated by ATR‐FTIR and DSC. The in vitro release behavior of CFX from hydrogels is investigated at simulated physiological media, which exhibit initial burst and then slow drug release. The CFX release from ZWβCDP is slower than ANβCDP.

  相似文献   

10.
在前期合成并表征了可控降解抗感染材料环丙沙星聚氨酯(CFPU)的基础上,建立高效液相色谱法(HPLC)测定其体外降解释放抗菌药物环丙沙星的含量;通过制作累积药物释放曲线,考察不同降解介质及其浓度对药物释放的影响;并对累积药物释放曲线进行拟合,研究其体外可控降解的药物释放机制。结果表明建立的HPLC法简单准确可靠。该材料的降解具有生物响应性,且符合一级动力学;药物释放是以Ritger-Pappas方程(0.45  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号