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941.
Gianfranco Calogiuri Elisabetta Di Leo Lavjay Butani Stefano Pizzimenti Cristoforo Incorvaia Luigi Macchia Eustachio Nettis 《Clinical and molecular allergy : CMA》2017,15(1):8
Hypersensitivity to para-phenylenediamine (PPD) and related compounds induced by temporary black henna tattoos has become a serious health problem worldwide. Different patterns of sensitization with various clinical aspects are described in literature due to PPD associated to henna tattoo and these manifestations are likely correlated with the immunological and dermatological pathomechanisms involved. Henna is the Persian name of the plant Lawsonia inermis, Fam. Lythraceae. It is a woody shrub that grow in regions of North Africa, South Asia, India and Sri Lanka. Nowadays it is rather frequent to see temporary “tattoos” performed with henna. To make tattoos darker and long-lasting PPD has been associated to henna in tattoo drawings mixtures, so obtaining “black henna”. In these years there has been a rise of contact sensitization to PPD and in medical literature an increased number of cases have been reported on temporary henna tattoo application. Here we review the various clinical patterns related to PPD and henna tattoo, to investigate the possible link between clinic-morphological pictures and the immunological response to PPD and henna. The literature underlines that different clinical manifestations are related to black henna containing PPD, and its derivative products may cause delayed-type as well as immediate-type reactions. Further studies are needed to investigate the relationship between clinical and morphological aspects of PPD contact dermatitis and the T cell subsets predominance. 相似文献
942.
MAR‐Mediated transgene integration into permissive chromatin and increased expression by recombination pathway engineering 下载免费PDF全文
Kaja Kostyrko Samuel Neuenschwander Thomas Junier Alexandre Regamey Christian Iseli Emanuel Schmid‐Siegert Sandra Bosshard Stefano Majocchi Valérie Le Fourn Pierre‐Alain Girod Ioannis Xenarios Nicolas Mermod 《Biotechnology and bioengineering》2017,114(2):384-396
Untargeted plasmid integration into mammalian cell genomes remains a poorly understood and inefficient process. The formation of plasmid concatemers and their genomic integration has been ascribed either to non‐homologous end‐joining (NHEJ) or homologous recombination (HR) DNA repair pathways. However, a direct involvement of these pathways has remained unclear. Here, we show that the silencing of many HR factors enhanced plasmid concatemer formation and stable expression of the gene of interest in Chinese hamster ovary (CHO) cells, while the inhibition of NHEJ had no effect. However, genomic integration was decreased by the silencing of specific HR components, such as Rad51, and DNA synthesis‐dependent microhomology‐mediated end‐joining (SD‐MMEJ) activities. Genome‐wide analysis of the integration loci and junction sequences validated the prevalent use of the SD‐MMEJ pathway for transgene integration close to cellular genes, an effect shared with matrix attachment region (MAR) DNA elements that stimulate plasmid integration and expression. Overall, we conclude that SD‐MMEJ is the main mechanism driving the illegitimate genomic integration of foreign DNA in CHO cells, and we provide a recombination engineering approach that increases transgene integration and recombinant protein expression in these cells. Biotechnol. Bioeng. 2017;114: 384–396. © 2016 The Authors. Biotechnology and Bioengineering published by Wiley Periodicals, Inc. 相似文献
943.
Turco P Houssami N Bulgaresi P Troni GM Galanti L Cariaggi MP Cifarelli P Crocetti E Ciatto S 《Acta cytologica》2011,55(2):193-196
944.
Lambiase A Mantelli F Sacchetti M Rossi S Aloe L Bonini S 《Archives italiennes de biologie》2011,149(2):283-292
Nerve Growth Factor (NGF) and its receptors TrkA and p75 are expressed in physiological states in the anterior and posterior segments of the human eye, where they exert several tissue-specific functions. The roles played by NGF in the homeostasis of the eye and in vision are, therefore, crucial and have been widely investigated both in vitro and in vivo, with growing evidence of an NGF-pathway alteration in several ocular diseases. In this review we describe the functions of NGF in health and diseases states of the eye, and discuss the potential therapeutic effectiveness of NGF in preliminary clinical reports performed in severe ocular diseases unresponsive to any standard treatment. In fact, pharmacodynamic studies showing that NGF administered topically on the ocular surface affects not only the ocular surface but is also able to reach the retina, optic nerve and brain, recently opened new perspectives for the treatment of challenging ocular surface diseases, optic nerve diseases, and degenerative diseases of the retina currently lacking an effective therapy. 相似文献
945.
Lee DW El Khoury Y Francia F Zambelli B Ciurli S Venturoli G Hellwig P Daldal F 《Biochemistry》2011,50(20):4263-4272
The cytochrome (cyt) bc(1) complex (cyt bc(1)) plays a major role in the electrogenic extrusion of protons across the membrane responsible for the proton motive force to produce ATP. Proton-coupled electron transfer underlying the catalysis of cyt bc(1) is generally accepted, but the molecular basis of coupling and associated proton efflux pathway(s) remains unclear. Herein we studied Zn(2+)-induced inhibition of Rhodobacter capsulatus cyt bc(1) using enzyme kinetics, isothermal titration calorimetry (ITC), and electrochemically induced Fourier transform infrared (FTIR) difference spectroscopy with the purpose of understanding the Zn(2+) binding mechanism and its inhibitory effect on cyt bc(1) function. Analogous studies were conducted with a mutant of cyt b, E295, a residue previously proposed to bind Zn(2+) on the basis of extended X-ray absorption fine-structure spectroscopy. ITC analysis indicated that mutation of E295 to valine, a noncoordinating residue, results in a decrease in Zn(2+) binding affinity. The kinetic study showed that wild-type cyt bc(1) and its E295V mutant have similar levels of apparent K(m) values for decylbenzohydroquinone as a substrate (4.9 ± 0.2 and 3.1 ± 0.4 μM, respectively), whereas their K(I) values for Zn(2+) are 8.3 and 38.5 μM, respectively. The calorimetry-based K(D) values for the high-affinity site of cyt bc(1) are on the same order of magnitude as the K(I) values derived from the kinetic analysis. Furthermore, the FTIR signal of protonated acidic residues was perturbed in the presence of Zn(2+), whereas the E295V mutant exhibited no significant change in electrochemically induced FTIR difference spectra measured in the presence and absence of Zn(2+). Our overall results indicate that the proton-active E295 residue near the Q(o) site of cyt bc(1) can bind directly to Zn(2+), resulting in a decrease in the electron transferring activity without changing drastically the redox potentials of the cofactors of the enzyme. We conclude that E295 is involved in proton efflux coupled to electron transfer at the Q(o) site of cyt bc(1). 相似文献
946.
The protein Numb does not live up to its name. This passive-sounding protein is anything but spent. Originally identified as a cell-fate determinant in Drosophila development, Numb received a good deal of attention as an inhibitor of the Notch receptor signaling pathway. It turns out, however, that Numb does a lot more than simply regulate Notch. It has been implicated in a variety of biochemical pathways connected with signaling (it regulates Notch-, Hedgehog- and TP53-activated pathways), endocytosis (it is involved in cargo internalization and recycling), determination of polarity (it interacts with the PAR complex, and regulates adherens and tight junctions), and ubiquitination (it exploits this mechanism to regulate protein function and stability). This complex biochemical network lies at the heart of Numb's involvement in diverse cellular phenotypes, including cell fate developmental decisions, maintenance of stem cell compartments, regulation of cell polarity and adhesion, and migration. Considering its multifaceted role in cellular homeostasis, it is not surprising that Numb has been implicated in cancer as a tumor suppressor. Our major goal here is to explain the cancer-related role of Numb based on our understanding of its role in cell physiology. We will attempt to do this by reviewing the present knowledge of Numb at the biochemical and functional level, and by integrating its apparently heterogeneous functions into a unifying scenario, based on our recently proposed concept of the "endocytic matrix". Finally, we will discuss the role of Numb in the maintenance of the normal stem cell compartment, as a starting point to interpret the tumor suppressor function of Numb in the context of the cancer stem cell hypothesis. 相似文献
947.
Colombo M Ricagno S Barbiroli A Santambrogio C Giorgetti S Raimondi S Bonomi F Grandori R Bellotti V Bolognesi M 《Journal of biochemistry》2011,150(1):39-47
Beta-2 microglobulin (β2m) is the light chain of Class I major histocompatibility complex (MHC-I) complex. β2m is an intrinsically amyloidogenic protein capable of forming amyloid fibrils in vitro and in vivo. β2m displays the typical immunoglobulin-like fold with a disulphide bridge (Cys25-Cys80) cross-linking the two β-sheets. Engineering of the loop comprised between β-strands D and E has shown that mutations in this region affect protein structure, fold stability, folding kinetics and amyloid aggregation properties. Such overall effects have been related to the DE loop backbone structure, which presents a strained conformation in the wild-type (wt) protein, and a type I β-turn in the W60G mutant. Here, we report a biophysical and structural characterization of the K58P-W60G β2m mutant, where a Pro residue has been introduced in the type I β-turn i + 1 position. The K58P-W60G mutant shows improved chemical and temperature stability and faster folding relative to wt β2m. The crystal structure (1.25 ? resolution) shows that the Cys25-Cys80 disulphide bridge is unexpectedly severed, in agreement with electrospray ionization-mass spectrometry (ESI-MS) spectra that indicate that a fraction of the purified protein lacks the internal disulphide bond. These observations suggest a stabilizing role for Pro58, and stress a crucial role for the DE loop in determining β2m biophysical properties. 相似文献
948.
Mammalian CLC proteins comprise both Cl- channels and Cl-/H+ antiporters that carry out fundamental physiological tasks by transporting Cl- across plasma membrane and intracellular compartments. The NO3- over Cl- preference of a plant CLC transporter has been pinpointed to a conserved serine residue located at Scen and it is generally assumed that the other two binding sites of CLCs, Sext and Sin, do not substantially contribute to anion selectivity. Here we show for the Cl-/H+ antiporter CLC-5 that the conserved and extracellularly exposed Lys210 residue is critical to determine the anion specificity for transport activity. In particular, mutations that neutralize or invert the charge at this position reverse the NO3- over Cl- preference of WT CLC-5 at a concentration of 100 mm, but do not modify the coupling stoichiometry with H+. The importance of the electrical charge is shown by chemical modification of K210C with positively charged cysteine-reactive compounds that reintroduce the WT preference for Cl-. At saturating extracellular anion concentrations, neutralization of Lys210 is of little impact on the anion preference, suggesting an important role of Lys210 on the association rate of extracellular anions to Sext. 相似文献
949.
Desulfovibrio sp. A2 is an anaerobic gram-negative sulfate-reducing bacterium with remarkable tolerance to copper. It was isolated from wastewater effluents of a zinc smelter at the Urals. Here, we report the 4.2-Mb draft genome sequence of Desulfovibrio sp. A2 and identify potential copper resistance mechanisms. 相似文献
950.
1. Individuals of the same species often exhibit consistent differences in metabolic rate, but the effects of such differences on ecologically important behaviours remain largely unknown. In particular, it is unclear whether there is a cause-and-effect relationship between metabolic rate and the tendency to take risks while foraging. Individuals with higher metabolic rates may need to take greater risks while foraging to obtain the additional food required to satisfy their energy requirements. Such a relationship could be exacerbated by food deprivation if a higher metabolic demand also causes greater mass loss and hunger. 2. We investigated relationships among metabolic rate, risk-taking and tolerance of food deprivation in juvenile European sea bass. Individual fish were tested for risk-taking behaviours following a simulated predator attack, both before and after a 7-day period of food deprivation. The results were then related to their routine metabolic rate (RMR), which was measured throughout the period of food deprivation. 3. The amount of risk displayed by individual fish before food deprivation showed no relationship with RMR. After food deprivation, however, the amount of risk among individuals was positively correlated with RMR. In general, most fish showed an increase in risk-taking after food deprivation, and the magnitude of the increase in risk-taking was correlated with the rate of individual mass loss during food deprivation, which was itself strongly correlated with RMR. 4. The observation that RMR was related to risk-taking behaviour after food deprivation, but not before, suggests that although RMR can influence risk-taking, the strength of the relationship is flexible and context dependent. The effects of RMR on risk-taking may be subtle or non-existent in regularly feeding animals, but may lead to variability in risk-taking among individuals when food is scarce or supply is unpredictable. This synergistic relationship between RMR and food deprivation could lead to an increased likelihood of being predated for individuals with a relatively high intrinsic energy demand during times when food is scarce. 相似文献