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1.
Cleavage of the HIV replication primer tRNALys,3 in human cells expressing bacterial anticodon nuclease. 下载免费PDF全文
Anticodon nuclease is a bacterial restriction enzyme directed against tRNA(Lys). We report that anticodon nuclease also cleaves mammalian tRNA(Lys) molecules, with preference and site specificity shown towards the natural substrate. Expression of the anticodon nuclease core polypeptide PrrC in HeLa cells from a recombinant vaccinia virus elicited cleavage of intracellular tRNA(Lys),3. The data justify an inquiry into the possible application of anticodon nuclease as an inhibitor of tRNA(Lys),3-primed HIV replication. They also indicate that the anticodon region of tRNA(Lys) is a substrate recognition site and suggest that PrrC harbors the enzymatic activity. 相似文献
2.
Physiological implications of K accumulation in heart muscle 总被引:1,自引:0,他引:1
M Morad 《Federation proceedings》1980,39(5):1533-1539
K+-selective microelectrodes in conjugation with the voltage clamp technique were used to examine the voltage and time dependence of K+ efflux and accumulation in cardiac muscle. K+ efflux per action potential is about 10 to 30 pmoles/cm2 per sec. Accumulation of K+ in the paracellular space plays an important role in regulation of action potential duration, so that the [K+]o prior to generation of an action potential determines the duration of following action potential. This regulation is brought about by the shift of inward rectifying K+ current along the voltage axis, so at higher [K+]o there is more outward current at plateau potentials. Monitoring [K+]o after a period of rapid beating provides quantitative data regarding Na-pump activity. The data suggest the Na-pump is electrogenic, making it difficult to assess the extent of K+ accumulation from the measurements of resting potential alone. These studies indicate that changes in [K+]o not only reflect outward membrane currents and Na-pump activity, but also play an important physiological regulatory role in determining the duration of the action potential. 相似文献
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Amjad Ullah Ivana Tlak Gajger Arnold Majoros Showket Ahmad Dar Sanaullah Khan Ayesha Haleem Shah Muhammad Nasir Khabir Riaz Hussain Hikmat Ullah Khan Mehwish Hameed Syed Ishtiaq Anjum 《Saudi Journal of Biological Sciences》2021,28(1):523-530
Honey bee is vital for pollination and ecological services, boosting crops productivity in terms of quality and quantity and production of colony products: wax, royal jelly, bee venom, honey, pollen and propolis. Honey bees are most important plant pollinators and almost one third of diet depends on bee’s pollination, worth billions of dollars. Hence the role that honey bees have in environment and their economic importance in food production, their health is of dominant significance. Honey bees can be infected by various pathogens like: viruses, bacteria, fungi, or infested by parasitic mites. At least more than 20 viruses have been identified to infect honey bees worldwide, generally from Dicistroviridae as well as Iflaviridae families, like ABPV (Acute Bee Paralysis Virus), BQCV (Black Queen Cell Virus), KBV (Kashmir Bee Virus), SBV (Sacbrood Virus), CBPV (Chronic bee paralysis virus), SBPV (Slow Bee Paralysis Virus) along with IAPV (Israeli acute paralysis virus), and DWV (Deformed Wing Virus) are prominent and cause infections harmful for honey bee colonies health. This issue about honey bee viruses demonstrates remarkably how diverse this field is, and considerable work has to be done to get a comprehensive interpretation of the bee virology. 相似文献
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N. Madan N. Sundar Raj M.A. Farook S. Vimal C. Venkatesan S. Abdul Majeed K.S.N. Nambi A.S. Sahul Hameed 《Process Biochemistry》2013,48(12):1893-1898
Hepatopancreatic Parvovirus (HPV) causes infection in the early stages of shrimp leading to retarded growth, ultimaltely resulting in monetary loss to the shrimp farmers. To over come this situation screening of post-larvae (PL) by immunology-based diagnostics is required. Hence, the specific gene of capsid protein for HPV was cloned into pRSET B expression vector and rHCP overexpressed with 6-histidine tagged fusion protein in Escherichia coli BL21(DE3). Immunology-based methods like Western blot, dot blot and ELISA techniques were employed to detect HPV in infected samples using the antiserum raised in rabbits against recombinant HCP of HPV. The dot blot assay using anti-rHCP was found to be capable of detecting HPV in HPV infected post-larvae as early as at 24 h post infection. The antiserum could detect the HPV in the infected samples at 1 ng of total protein. HPV infection estimated by ELISA using anti-HCP and pure r-HCP as a standard was found to increase gradually during the course of infection from 24 h post infection. The sensitivity of antibody-based diagnostics employed in the present study was compared with that of PCR diagnostic method to screen the post-larvae for the detection of HPV. 相似文献
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Samy A.F. Morad Jonathan C. Levin Su-Fern Tan Todd E. Fox David J. Feith Myles C. Cabot 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2013,1831(12):1657-1664
Acid ceramidase (AC), EC 3.5.1.23, a lysosomal enzyme, catalyzes the hydrolysis of ceramide to constituent sphingoid base, sphingosine, and fatty acid. Because AC regulates the levels of pro-apoptotic ceramide and mitogenic sphingosine-1-phosphate, it is considered an apt target in cancer therapy. The present study reveals, for the first time, that the prominent antiestrogen, tamoxifen, is a pan-effective AC inhibitor in the low, single digit micromolar range, as demonstrated in a wide spectrum of cancer cell types, prostate, pancreatic, colorectal, and breast. Prostate cancer cells were chosen for the detailed investigations. Treatment of intact PC-3 cells with tamoxifen produced time- and dose-dependent inhibition of AC activity. Tamoxifen did not impact cell viability nor did it inhibit AC activity in cell-free assays. In pursuit of mechanism of action, we demonstrate that tamoxifen induced time-, as early as 5 min, and dose-dependent, as low as 5 μM, increases in lysosomal membrane permeability (LMP), and time- and dose-dependent downregulation of AC protein expression. Assessing various protease inhibitors revealed that a cathepsin B inhibitor blocked tamoxifen-elicited downregulation of AC protein; however, this action failed to restore AC activity unless assayed in a cell-free system at pH 4.5. In addition, pretreatment with tamoxifen inhibited PC-3 cell migration. Toremifene, an antiestrogen structurally similar to tamoxifen, was also a potent inhibitor of AC activity. This study reveals a new, off-target action of tamoxifen that may be of benefit to enhance anticancer therapies that either incorporate ceramide or target ceramide metabolism. 相似文献
9.
Shahabzadeh Zeinab Darvishzadeh Reza Mohammadi Reza Jafari Morad 《Plant Molecular Biology Reporter》2020,38(2):187-188
Plant Molecular Biology Reporter - The original version of this article unfortunately contained some mistakes in article Title and Table 1. 相似文献
10.
Fouad A. Almomani Bilal Alfukaha Khalid Hameed 《Archives Of Phytopathology And Plant Protection》2013,46(17):2070-2079
Forty-two Pectobacterium isolates were recovered from contaminated soil and rotted vegetables in Jordan. Twenty of them were belonged to; Pectobacterium carotovorum subsp. Carotovorum (Pbc) (= Erwinia carotovora subsp. carotovora), 11 isolates were belonged to Pectobacterium atrospeticum (= Erwinia carotovora subsp. atroseptica) (Pba) and 11 isolates were not classifiable (Pbs). Maceration activity of the 42 proved their ability to macerate potato, carrot and radish slices. Maceration activity of the isolates either of the same subspecies or in between the isolates of different subspecies isolated from the same host or from different hosts was varied. The measured concentration in μM?ml?1 of both cellulase and pectinase enzymes was variable too. The Rapid amplified polymorphic DNA-PCR finger printing of total genomic DNA using a pair of 10-mer oligonucleotide primers amplification showed similar DNA bands with some polymorphic variations amongst the isolates. 相似文献