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排序方式: 共有611条查询结果,搜索用时 15 毫秒
51.
Ragab M. Shafik Farid S. G. Soliman Mona M. El-Semary Manal N. S. Saudi Rasha Y. El-Bayaa 《Medicinal chemistry research》2009,18(3):187-205
On the basis of the most stable stereorotameric (R) forms of πNH-histamine (2), the trans (1-TR) and gauche (1-GR) forms have both been reported to be involved in potentiation of H1-receptors. Apart from the known classic models of H1-antagonists that mostly belong to 1-TR, a new topographic receptor map for 1-GR has been postulated. Twenty-seven new compounds
pertaining to novel nonclassic molecular models related to 1-GR have been postulated as potential nonsedating, less toxic
H1-antagonists. Representative members of the new agents were investigated for H1-blocking activity by using isolated segments from guinea pig ileum. Many of the tested new compounds exhibited activities
comparable to that of acrivastine as a reference nonsedating drug. The C log P values of the new agents were lower than that of acrivastine (4.34), which might indicate decreased tendency to cross the
blood–brain barrier. The most pronounced activity was displayed by the 5-substituted aminomethylenepyrimidine-2,4,6-triones
(21, 23) since they displayed nearly equal 50% inhibition concentrations (IC50) (6.12 × 10−6 M) and lower C log P values. 相似文献
52.
53.
A critical link exists between an individual's ability to repair cellular DNA damage and cancer development, progression, and response to therapy. Knowledge gained about the proteins involved and types of damage repaired by the individual DNA repair pathways has led to the development of a variety of assays aimed at determining an individual's DNA repair capacity. These assays and their use in the analysis of clinical samples have yielded useful though somewhat conflicting data. In this review article, we discuss the major DNA repair pathways, the proteins and genes required for each, assays used to analyze activity, and the relevant clinical studies to date. With the recent results from clinical trials targeting specific DNA repair proteins for the treatment of cancer, accurate, reproducible, and relevant analysis of DNA repair takes on an even greater significance. We highlight the strengths and limitations of these DNA repair studies and assays, with respect to the clinical assessment of DNA repair capacity to determine cancer development and response to therapy. 相似文献
54.
Mostafa M. Ghorab Fatma A. Ragab Mostafa M. Hamed 《European journal of medicinal chemistry》2009,44(10):4211-4217
Sulfonamides posses many types of biological activities and have recently been reported to show substantial antitumor activity in vitro and/or in vivo. There are a variety of mechanisms for the anticancer activity and the most prominent of these is through the inhibition of carbonic anhydrase isozymes. The present work reports the synthesis of some novel quinoline and pyrimido[4,5-b]quinoline derivatives bearing a substituted or unsubstituted sulfonamide moiety. The design of the structures of these compounds complies with the general pharmacophore of the sulfonamide compounds that act as carbonic anhydrase (CA) inhibitors as this may play a role in their anticancer activity. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against breast cancer cell line (MCF7). Most of the screened compounds showed interesting cytotoxic activities compared to a reference drug. 相似文献
55.
Some novel 4-(quinolin-1-yl)-benzenesulfonamide and 4-(pyrimido[4,5-b]quinolin-10-yl)-benzenesulfonamide derivatives have been synthesized. All the newly synthesized target compounds were subjected to in vitro cytotoxic screening to be evaluated for their anticancer activity against Ehrlich ascites carcinoma cells. Among these new compounds, compounds 9a, 11, 12b, 18 and, in particular, 19 showed promising in vitro cytotoxic activity compared with doxorubicin (CAS 23214-92-8) as a reference drug. Moreover, compound 8 exhibited in vivo radioprotective activity against gamma-irradiation in mice. 相似文献
56.
Yousry A. Ammar Jehan A. Micky Dina S. Aboul-Magd Sondos M. A. Abd El-Hafez Sadia A. Hessein Abeer M. Ali Ahmed Ragab 《Chemical biology & drug design》2023,101(2):245-270
This study aimed to synthesize new potent quinoline derivatives based on hydrazone moieties and evaluate their antimicrobial activity. The newly synthesized hydrazono-quinoline derivatives 2 , 5a , 9 , and 10b showed the highest antimicrobial activity with MIC values ≤1.0 μg/ml against bacteria and ≤8.0 μg/ml against the fungi. Further, these derivatives exhibited bactericidal and fungicidal effects with MBC/MIC and MFC/MIC ratio ≤4. Surprisingly, the most active compounds displayed good inhibition to biofilm formation with MBEC values ranging between (40.0 ± 10.0 – 230.0 ± 31.0) and (67.0 ± 24.0 – 347.0 ± 15.0) μg/ml against Staphylococcus aureus and Pseudomonas aeruginosa, respectively. The hemolytic assays confirmed that the hydrazono-quinoline derivatives are non-toxic with low % lysis values ranging from 4.62% to 14.4% at a 1.0 mg/ml concentration. Besides, compound 5a exhibited the lowest hemolytic activity value of ~4.62%. Furthermore, the study suggests that the hydrazono-quinoline analogs exert their antibacterial activity as dual inhibitors for DNA gyrase and DNA topoisomerase IV enzymes with IC50 values ranging between (4.56 ± 0.3 – 21.67 ± 0.45) and (6.77 ± 0.4 – 20.41 ± 0.32) μM, respectively. Additionally, the recent work advocated that compound 5a showed the reference SAL at the ɣ-radiation dose of 10.0 kGy in the sterilization process without affecting its chemical structure. Finally, the in silico drug-likeness, toxicity properties, and molecular docking simulation were performed. Besides, the result exhibited good oral-bioavailability, lower toxicity prediction, and lower binding energy with good binding mode rather than the positive control. 相似文献
57.
Bassem M. Salama Wafaa A. Helmy Tamer I. M. Ragab Mamdouh M. Ali Hanan A. A. Taie Mona A. Esawy 《Journal of basic microbiology》2019,59(10):1004-1015
Screening of 18 bacterial honey isolates revealed that all the isolates were levansucrase producers. The most potent isolate that achieved the highest activity (45.66 U/ml) was identified as Bacillus subtilis NRC based on morphological examination and 16S rRNA. The results recorded the necessity of starch (5 g/L), baker's yeast (12.5 g/L), and AlCl3 (5 mM) in improvement of the enzyme productivity. The Bacillus subtilis levansucrase was eluted as a single protein in one purification step. The enzyme molecular weight was (14 kDa). It showed its optimum activity at 45°C and could retain 60% of its activity after incubation at 50°C for 2 h. Its optimum activity was obtained at pH 8.2 and the enzyme showed great pH stability in both acidic and alkaline ranges. Unlike, most levansucrases all tested metals had an adverse effect in enzyme activity. The enzyme had antioxidant activities and were characterized as spherical micro‐ and nanoparticles by transmission electron microscopy. The effect of growth conditions and medium composition in levan structure and its fibrinolytic activity was evaluated. 相似文献
58.
59.
El-Khalik Sarah Ragab Abd Ibrahim Rowida Raafat Ghafar Muhammad Tarek Abdel Shatat Doaa El-Deeb Omnia Safwat 《Journal of assisted reproduction and genetics》2022,39(5):1115-1124
Journal of Assisted Reproduction and Genetics - Ferroptosis is associated with oxidative stress (OS) and is caused by iron-dependent lipid-peroxidative damage, but its role in PE is unclear. The... 相似文献
60.
Doaa M. Al-Eraky Omneya M. Helmy Yasser M. Ragab Zeinab Abdul-Khalek Eman A. El-Seidi Mohammed A. Ramadan 《Infectious agents and cancer》2018,13(1):24