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261.
262.
Bioleaching is an economic, novel practice for extraction of metals from their sources by microorganisms. The current study aimed to extract uranium from Egyptian ores using native strains of actinomycetes. Two types of rocks and one ore sample were collected from west-central Sinai, Egypt. Major oxides of the samples and fourteen heavy metals, including uranium, were determined. X-ray diffraction analysis proved that uranium was present in the samples in various structures. Uranium was present in different concentrations, 220, 770, and 550 mg/kg in sandstone, granite, and manganese ore, respectively. Thirty-four actinomycete isolates were recovered from the studied samples using four different isolation media. Acid production capabilities were employed to select isolates for further leaching experiments. Bioleaching experiments were carried out using sterile and non-sterile ore samples. Using sterile ore samples, the highest solubilization percentages of U3O8 were 44.5, 38.55, and 16.76% from sandstone, manganese ore, and granite sample, achieved by isolates UA12, UA5, and U7, respectively. Lower solubilization percentages of U3O8 were recorded by using non-sterile ore samples. Investigating the factors affecting the bioleaching abilities of the tested organisms revealed that 10 days of incubation with 4% pulp density were the best conditions for U3O8 solubilization. The most efficient isolates were identified using 16S rRNA gene sequence analysis. UA12 identified to be Streptomyces bacillaris, while UA5 could not be identified, and U7 was assigned as uncultured bacterium clone. Scanning electron microscope examination of the bioleaching experiment showed different growth intensity within the active isolates. For larger-scale extraction purposes, a kilogram of sandstone, containing 220 mg of U3O8, was used in the form of a truncated cone in a heap leaching experiment. After 20 cycles, 14.72 mg/l (6.7%) of U3O8 was leached by S. bacillaris, while 19.36 mg/l (8.8%) of U3O8 was leached by chemical leaching using sulfuric acid. The results of this study prove that the extraction of uranium using actinomycetes could be exploited as less polluting, more economical, and more effective than traditional chemical extraction especially from low-grade ores or mining wastes. 相似文献
263.
Usama Abdulla David Talbert Mary Lucas Mary Mullarkey 《BMJ (Clinical research ed.)》1972,3(5830):797-799
In-vitro experiments have been undertaken to assess the effect of ultrasound at diagnostic and therapeutic levels on chromosomes of human lymphocyte cultures. The frequency used was about 2 MHz. The intensity was that of diagnostic level, 23 mW/cm2, which was increased stepwise to 3·5 W/cm2. The time of exposure varied from two to eight hours. No difference could be detected between the numbers of cells with aberrations in the insonated and control cultures, but aggregation of red cells was observed at high intensities. 相似文献
264.
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Varshasnata Mohanty Yashwanth Subbannayya Shankargouda Patil Vinuth N. Puttamallesh Mohd. Altaf Najar Keshava K. Datta Sneha M. Pinto Sameera Begum Neeta Mohanty Samapika Routray Riaz Abdulla Jay Gopal Ray David Sidransky Harsha Gowda T. S. Keshava Prasad Aditi Chatterjee 《Journal of cell communication and signaling》2021,15(3):447
266.
Wagdy M. Eldehna Mahmoud F. Abo-Ashour Tarfah Al-Warhi Sara T. Al-Rashood Amal Alharbi Rezk R. Ayyad Khayal Al-Khayal Maha Abdulla Hatem A. Abdel-Aziz Rehan Ahmad Radwan El-Haggar 《Journal of enzyme inhibition and medicinal chemistry》2021,36(1):319
Mitochondrial anti-apoptotic Bcl2 and BclxL proteins, are overexpressed in multiple tumour types, and has been involved in the progression and survival of malignant cells. Therefore, inhibition of such proteins has become a validated and attractive target for anticancer drug discovery. In this manner, the present studies developed a series of novel isatin–indole conjugates (7a-j and 9a-e) as potential anticancer Bcl2 and BclxL inhibitors. The progression of the two examined colorectal cancer cell lines was significantly inhibited by all of the prepared compounds with IC50 ranges132–611 nM compared to IC50 = 4.6 µM for 5FU, against HT-29 and IC50 ranges 37–468 nM compared to IC50 = 1.5 µM for 5FU, against SW-620. Thereafter, compounds 7c and 7g were selected for further investigations. Interestingly, both compounds exhibited selective cytotoxicity against both cell lines with high safety to normal fibroblast (HFF-1). In addition, both compounds 7c and 7g induced apoptosis and inhibited Bcl2 and BclxL expression in a dose-dependent manner. Collectively, the high potency and selective cytotoxicity suggested that conjugates 7c and 7g could be a starting point for further optimisation to develop novel pro-apoptotic and antitumor agents towards colon cancer. 相似文献