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   22篇
  免费   1篇
  国内免费   1篇
化学   22篇
物理学   2篇
  2022年   1篇
  2021年   5篇
  2020年   1篇
  2016年   1篇
  2015年   1篇
  2013年   1篇
  2012年   1篇
  2011年   3篇
  2008年   1篇
  2007年   2篇
  2006年   1篇
  2005年   2篇
  2002年   2篇
  2001年   1篇
  1999年   1篇
排序方式: 共有24条查询结果,搜索用时 15 毫秒
11.
The third generation of aminobiphenyl palladacycle pre‐catalyst “G3‐Xantphos” enables functionalization of peptides containing cysteine in high yields. The conjugation (bioconjugation) occurs chemoselectively at room temperature under biocompatible conditions. Extension of the method to protein functionalization allows selective bioconjugation of the trastuzumab antibody.  相似文献   
12.
Background: Myrtus communis (M. communis) is a wild aromatic plant used for traditional herbal medicine that can be demonstrated in insecticidal, antioxidant, anti-inflammatory, and antimicrobial activity of its essential oils (MCEO). Aim: The present study aimed to evaluate the prophylactic effects of M. communis essential oil (MCEO) against chronic toxoplasmosis induced by the Tehran strain of Toxoplasma gondii in mice. Methods: Gas chromatography/mass spectrometry (GC/MS) analysis was performed to determine the chemical composition of MCEO. Mice were then orally administrated with MCEO at the doses of 100, 200, and 300 mg/kg/day and also atovaquone 100 mg/kg for 21 days. On the 15th day, the mice were infected with the intraperitoneal inoculation of 20–25 tissue cysts from the Tehran strain of T. gondii. The mean numbers of brain tissue cysts and the mRNA levels of IL-12 and IFN-γ in mice of each tested group were measured. Results: By GC/MS, the major constituents were α-pinene (24.7%), 1,8-cineole (19.6%), and linalool (12.6%), respectively. The results demonstrated that the mean number of T. gondii tissue cysts in experimental groups Ex1 (p < 0.05), Ex2 (p < 0.001) and Ex3 (p < 0.001) was meaningfully reduced in a dose-dependent manner compared with the control group (C2). The mean diameter of tissue cyst was significantly reduced in mice of the experimental groups Ex2 (p < 0.01) and Ex3 (p < 0.001). The results demonstrated that although the mRNA levels of IFN-γ and IL-12 were elevated in all mice of experimental groups, a significant increase (p < 0.001) was observed in tested groups of Ex2 and Ex3 when compared with control groups. Conclusion: The findings of the present study demonstrated the potent prophylactic effects of MCEO especially in the doses 200 and 300 mg/kg in mice infected with T. gondii. Although the exceptional anti-Toxoplasma effects of MCEO and other possessions, such as improved innate immunity and low toxicity are positive topics, there is, however, a need for more proof from investigations in this field.  相似文献   
13.
Multi-Inputs-Multi-Outputs (MIMO) systems are recognized mainly in industrial applications with both input and state couplings, and uncertainties. The essential principle to deal with such difficulties is to eliminate the input couplings, then estimate the remaining issues in real-time, followed by an elimination process from the input channels. These difficulties are resolved in this research paper, where a decentralized control scheme is suggested using an Improved Active Disturbance Rejection Control (IADRC) configuration. A theoretical analysis using a state-space eigenvalue test followed by numerical simulations on a general uncertain nonlinear highly coupled MIMO system validated the effectiveness of the proposed control scheme in controlling such MIMO systems. Time-domain comparisons with the Conventional Active Disturbance Rejection Control (CADRC)-based decentralizing control scheme are also included.  相似文献   
14.
The reaction between 3‐amino‐2,3‐dihydro‐7,9‐dimethyl‐2‐thioxo‐pyrido[3′,2′:4,5]thieno[3,2‐d]‐pyrimidin‐4(1H)‐one 4 or its 2‐methylthio derivative 5 with hydrazonoyl halides 6 in dioxane in the presence of triethylamine under reflux has followed heterocyclization reaction to yield pyrido[3″,2″:4′,5′]‐thieno[3′,2′:4,5]pyrimido[2,1‐c][1,2,4,5]tetrazin‐6(4H)‐ones 9 . On the other hand, reaction of compound 4 with hydrazonoyl halides 6 in sodium ethoxide at room temperature led to formation of hydrazonothioate compounds 10 . The latter on treatment with glacial acetic acid produced tetracyclic compounds, namely 2‐arylhydrazonopyrido[3″,2″:4′,5′]thieno [3′,2′:4,5]pyrimido[2,1‐b][1,3,4]thiadiazinones 11 . An alternative method was carried out to prove the structure of product 11 . The mechanism of the reaction under study was proposed and the products were screened for their biological activity.  相似文献   
15.
The Ni catalysts supported on γ-Al2O3 were synthesized by an impregnation method.Their catalytic performance in methane dry reforming was investigated.The reforming reactions were carried out in a microreactor using a CO2:CH4 feed ratio of 1:1,a F/W = 2640 ml/(h·g),reaction temperatures between 500-850 ?C,and at atmospheric pressure.The influence of Ca,Ce,and Zr promoters on catalyst stability,coke deposition,and the H2/CO ratio were also studied.Effluents were analyzed using an online gas chromatograph equ...  相似文献   
16.
17.
Microwave-assisted synthesis of some novel compounds, namely, 3-(2-methyl-1H-indol-3-yl)-6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a,b was accomplished via bromination of 2-methyl-3-[4-(arylideneamino)-5-mercapto-4H-[1,2,4]triazol-3-yl]-1H-indoles 3a,b. Also, new [1,3,4]thiadiazoles 12a,b, [1,2,4]triazoles 15a,b and [1,3,4]oxadiazoles 19a,b, with indole moieties, were prepared by cyclization of 1-[(2-methyl-1H-indole)-3-carbonyl]thiosemicarbazides 8a,b under microwave irradiation using different reaction conditions. Moreover, reaction of acid hydrazide 7 with ethyl 2-(N-phenylhydrazono)-3-oxobutanoate (20) gave the respective phenylhydrazonopyrazole derivative 21 under the reaction conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data (IR, (1)H-NMR, (13)C-NMR, MS). The antifungal and antibacterial activities of the new products were also evaluated.  相似文献   
18.
Background: Today, the present protoscolicidals used to minimize the serious risks during hydatid cyst surgery are not completely safe and have various adverse side effects. The present study aimed to evaluate the chemical composition and apoptotic activity of Ferula macrecolea essential oil (FMEO) as well as its in vitro and ex vivo protoscolicidal effects against hydatid cyst protoscoleces. Methods: Gas chromatography/mass spectrometry (GC/MS) analysis was performed to determine the chemical composition of FMEO. Protoscoleces of hydatid cysts were collected from liver fertile hydatid cysts of infected sheep and were then treated with various concentrations of the essential oil (75, 150, and 300 µL/mL) for 5–60 min in vitro and ex vivo. Then, by using the eosin exclusion test, the viability of the protoscoleces was studied. The caspase-3-like activity of the FMEO-treated protoscoleces was also evaluated through the colorimetric protease assay Sigma Kit based on the manufacturer’s instructions. Results: According to GC/MS, the main constituents of the essential oil were terpinolene (77.72%), n-nonanal (4.47%), and linalool (4.35%), respectively. In vitro, the maximum protoscolicidal activity of FMEO was observed at the concentrations of 150 and 300 µL/mL, such that 100% of the protoscoleces were killed after 30 and 20 min of exposure, respectively. Based on the obtained findings, the results demonstrate that FMEO required a longer time to kill protoscoleces ex vivo; after 12 min of exposure to FMEO, only 13.4% of the protoscoleces remained alive. After 48 h of the treatment of protoscoleces, FMEO, in a dose-dependent manner and at doses of 75, 150, and 300 µL/mL, induced the activation of the caspase enzyme by 24.3, 35.3, and 48.3%, respectively. Conclusions: Our findings demonstrate the potent protoscolicidal effects of FMEO in vitro and ex vivo; however, further studies are required to assess the safety and the efficiency of FMEO as a promising scolicidal agent in a preclinical model and clinical setting.  相似文献   
19.
20.
A novel series of 1-aryl-N-[4-phenyl-5-(arylazo)thiazol-2-yl)methanimines has been synthesized via the condensation of 2-amino-4-phenyl-5-arylazothiazole with various aromatic aldehydes. The synthesized imines were characterized by spectroscopic techniques, namely 1H and 13C-NMR, FTIR, MS, and Elemental Analysis. A molecular comparative docking study for 3a–f was calculated, with reference to two approved drugs, Molnupiravir and Remdesivir, using 7BQY (Mpro; PDB code 7BQY; resolution: 1.7 A°) under identical conditions. The binding scores against 7BQY were in the range of −7.7 to −8.7 kcal/mol for 3a–f. The high scores of the compounds indicated an enhanced binding affinity of the molecules to the receptor. This is due to the hydrophobic interactions and multi-hydrogen bonds between 3a–f ligands and the receptor’s active amino acid residues. The main aim of using in silco molecular docking was to rank 3a–f with respect to the approved drugs, Molnupiravir and Remdesivir, using free energy methods as greener pastures. A further interesting comparison presented the laydown of the ligands before and after molecular docking. These results and other supporting statistical analyses suggested that ligands 3a–f deserve further investigation in the context of potential therapeutic agents for COVID-19. Free-cost, PASS, SwissADME, and Way2drug were used in this research paper to determine the possible biological activities and cytotoxicity of 3a–f.  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