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101.
Anti-cancer effect and mechanism of cell death were investigated in a battery of five thalidomide analogs containing one sulfur atom 2 or two sulfur atoms 36 and were compared with thalidomide 1 activity. The cytotoxic effect of thalidomide analogs 26 against Hep-G2, 1301, and HCT-116 cells was estimated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptosis and necrosis cell percentage was stained by ethidium bromide and acridine orange, DNA fragmentation, inhibition of histone deacetylase (HDAC), and total caspases were assayed by universal procedures and kits. We report here for the anti-cancer activity of thalidomide dithiocarbamate analog 3 and thalidomide dithioate analog 5 against Hep-G2 and HCT-116 cells, which was more cytotoxic than thalidomide itself, and that the cytotoxicity was associated with DNA fragmentation and was due to apoptosis and not necrosis. Moreover, we suggest that the cell death pathway is evoked by thalidomide dithiocarbamate analog 3 and thalidomide dithioate analog 5 in human hepatocellular carcinoma cells through multiple consequences that trigger apoptotic cell death; involving the enhancement of DNA fragmentation, the activation of caspases, and the induction of histone acetylation. In conclusion, thalidomide dithiocarbamate analog 3 and thalidomide dithioate analog 5 are promising anti-cancer agents more than thalidomide.  相似文献   
102.
Most studies measuring the agonist and antagonist activities of CCK analogs and derivatives on the exocrine pancreas have been done with in vitro models. However, extrapolation to the in vivo situation may be sometimes hazardous, due to the catabolism of the peptides by circulating and tissue peptidases, and to their eventual interaction with various endogenous factors. The present experiments were organized to measure the efficacy and potency on pancreatic secretion of the rat in vivo of a series of CCK 8 analogs whose binding and activity had been previously measured on guinea-pig and rat isolated acini. The molecules tested were derivatives of Boc-(Nle 28-Nle 31)-CCK 26–33 (1), and comprised 2-phenylethylester derivatives, des-Phe derivatives, and a series of pseudo-peptides with a “reduced” bond CH2-NH replacing the peptide bond in position 28–29 to 32–33. They were perfused in anaesthetized rats, and the outputs of sodium, bicarbonate and total protein were measured. All of the derivatives studied had in vivo the same efficacy as (1) on the output of protein, and were 10 to 500 times less potent. For most compounds, the relative order of potencies measured in vivo was similar to that measured in vitro on amylase secretion by rat acini. However, the derivatives with reduced bonds in positions 28–29 and 29–30 were respectively 3 and 2 times less potent in vivo, relative to (1), while derivatives with reduced bonds in positions 30–31, 31–32 and 32–33 were 1.5 to 2.5 times more potent in vivo. The 2-phenylethylester derivatives were 7 and 9 times as potent in vitro as in vivo. The des-Phe derivative, which had in vitro antagonist properties on guinea-pig acini, and acted like a partial agonist on rat acini, was in vivo a complete agonist and was relatively 300 times as potent in vivo as in vitro. These results indicate that the metabolism of the peptides and/or their interaction with endogenous factors may change appreciably the effect of CCK derivatives on pancreatic secretion of the rat in vivo.  相似文献   
103.
Social and economical development is closely associated with technological innovation and a well-developed biotechnological industry. In the last few years, Brazil’s scientific production has been steadily increasing; however, the number of patents is lagging behind, with technological and translational research requiring governmental incentive and reinforcement. The Cell and Molecular Therapy Center (NUCEL) was created to develop activities in the translational research field, addressing concrete problems found in biomedical and veterinary areas and actively searching for solutions by employing a genetic engineering approach to generate cell lines over-expressing recombinant proteins to be transferred to local biotech companies, aiming at furthering the development of a national competence for local production of biopharmaceuticals of widespread use and of life-saving importance. To this end, mammalian cell engineering technologies were used to generate cell lines over-expressing several different recombinant proteins of biomedical and biotechnological interest, namely, recombinant human Amylin/IAPP for diabetes treatment, human FVIII and FIX clotting factors for hemophilia, human and bovine FSH for fertility and reproduction, and human bone repair proteins (BMPs). Expression of some of these proteins is also being sought with the baculovirus/insect cell system (BEVS) which, in many cases, is able to deliver high-yield production of recombinant proteins with biological activity comparable to that of mammalian systems, but in a much more cost-effective manner. Transfer of some of these recombinant products to local Biotech companies has been pursued by taking advantage of the São Paulo State Foundation (FAPESP) and Federal Government (FINEP, CNPq) incentives for joint Research Development and Innovation partnership projects.  相似文献   
104.
为研究云南野生蔷薇属中的NBS类抗病基因,根据已知抗病基因NBSLRR序列中的保守区域设计简并引物,利用RTPCR技术从云南悬钩子蔷薇中进行体外扩增,获得了对应区域的cDNA片段,回收、克隆这些特异片段,测序分析,共得到4个含有NBSLRR保守结构域的抗病基因同源序列(RGAs),分别命名为AC9、AC39、AC50和AC68。它们与已报道的11个NBS类抗病基因相应区段的氨基酸序列相似性为5.4%~79.2%,其中这4个RGAs片段与Mi、RPS2、Pib和RPM1基因聚为一类。表明这4条RGAs序列可进一步用作悬钩子蔷薇抗病候选基因的分子筛选及遗传图谱的构建。  相似文献   
105.
黑色素合成是桦褐孔菌Phaeoporus obliquus次生代谢过程中的一个重要事件。黑色素的过多合成势必影响其他酚类的积累。本文以茉莉酸和双氧水为调控因子,开展了该突变体深层发酵过程酚类化合物积累研究。正常培养条件下,每升发酵液积累酚类化合物最高可达317.45mg/L,其中包括苯甲酸衍生物(45.3mg/L),黄酮苷元(74.4mg/L),黄酮苷(160mg/L)以及硬毛素类化合物(18.5mg/L)。加入茉莉酸后,总酚最大值增加到620.45mg/L,其中苯甲酸衍生物增加到230.26mg/L,黄酮苷元增加到166.86mg/L,而黄酮苷和硬毛素类化合物却分别降低到98.5mg/L和7.1mg,双氧水的加入没有提高总酚的最大积累(315.69mg/L)。因此,与野生型相比,黑色素缺失使总酚的积累有所增加,随茉莉L酸的加入总酚积累最大值增加近一倍。虽然双氧水的加入提高了苯丙氨酸裂解酶活性,但总酚的积累却没有增加,这可能是由于一部分酚类化合物在抗双氧水氧化胁迫过程中被消耗。  相似文献   
106.
Several unnatural derivatives of narciclasine were prepared in which the C-7 carbon was replaced with nitrogen. The 7-aza derivative and its N-oxide were prepared by the coupling of iodopicolinic acid with a conduramine unit derived chemoenzymatically from bromobenzene. Intramolecular Heck reaction was used to construct the isocarbostyryl ring system. The compounds were submitted to biological screening against cancer cell lines. Full experimental and spectra data are provided for all new compounds.  相似文献   
107.
A series of 4, 4-disubstituted proline analogs were designed, synthesized, and tested for selective inhibition of blood coagulation factor XIa in search of new non-vitamin K antagonists based oral anticoagulants for potential prevention and treatment of thrombotic diseases. Starting from a potent thrombin (FIIa) inhibitor chemotype with FIIa IC50 = 1 nM and FXIa IC50 = 160 nM, medicinal chemistry iterations guided by molecular modeling and structure-based drug design led to steady improvement of FXIa potency while dialing down thrombin activity and improving selectivity. Through this exercise, a thousand-fold enhancement of selectivity over thrombin was achieved with some analogs carrying factor XIa inhibition potencies in the 10 nM range. In this communication, we discuss the design principles and structure activity relationship (SAR) of these novel FXIa selective inhibitors.  相似文献   
108.
Abstract

We have reported previously that purine methylenecyclopropane analogs are potent agents against cytomegaloviruses. In an attempt to extend the activity of these compounds, the 2-amino-6-cyclopropylaminopurine analog, QYL-1064, was selected for further study by modifying the purine 6 substituent. A total of 22 analogs were tested against herpes simplex virus types 1 and 2 (HSV-1, HSV-2), varicella zoster virus (VZV), human cytomegalovirus (HCMV), murine cytomegalovirus (MCMV), Epstein-Barr virus (EBV), human herpesvirus type 6 (HHV-6) and human herpesvirus type 8 (HHV-8). Ten of the analogs had activity against at least one of the viruses tested. One compound had moderate activity against HSV-1 and six had activity against VZV. All but one compound was active against HCMV with a mean EC50 of 2.1 ± 0.6 µM, compared with a mean EC50 of 3.9 ± 0.8 µM for ganciclovir. Of special interest was the fact that eight of the ten compounds were active against both HHV-6A and HHV-6B with mean EC50 values of 6.0 ± 5.2 µM and <2.4 ± 1.5 µM, respectively. Only two compounds had activity against EBV, whereas all but one compound was active against HHV-8 with a mean EC50 of 3.1 ± 1.7 µM. These results indicate that members of this series of methylenecyclopropane analogs are highly active against HCMV, HHV-6, and HHV-8 but are less active against HSV, VZV, and EBV.  相似文献   
109.
Tetrahydroneotanshinlactone (TNT) and tetrahydronaphthalene-1-ol (TNO) derivatives were designed, synthesized, and evaluated for cytotoxic activity. The TNO derivatives were found to be a promising novel class of in vitro antitumor agents. The cyclohexene ring-A could dramatically affect the antitumor activity and selectivity. Compound 20 showed the highest potency with ED50 values of 0.7 and 1.7 μM against SK-BR-3 and ZR-75-1 breast cancer cell lines, respectively.  相似文献   
110.
Abstract

The novel N-bridgehead formycin analog 3- β-D-ribofuranosyl-8-amino-s-triazolo [4, 3-a] pyridine (8a-aza-4, 6-dideaza formycin) has been prepared from 5- [2, 3, 5-tri-O-benzoyl- β-D-ribofuranosyl] - (2H)-tetrazole and 2-chloro-3-nitropyridine. The synthetic route used an initial condensation followed by deprotection and subsequent hydrogenation to afford 2a. 2-Hydroxyethoxymethyl group, an acyclic group, that mimics the ribofuranose unit was also introduced. These compounds were tested against type 1 herpes and poliovirus in tissue culture and their effect on cellular RNA and DNA synthesis was determined. All derivatives possess considerable cytotoxic effect which is expressed more with ribofuranosyl derivatives.  相似文献   
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