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排序方式: 共有376条查询结果,搜索用时 78 毫秒
81.
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Alison E. Mahan Madeleine F. Jennewein Todd Suscovich Kendall Dionne Jacquelynne Tedesco Amy W. Chung Hendrik Streeck Maria Pau Hanneke Schuitemaker Don Francis Patricia Fast Dagna Laufer Bruce D. Walker Lindsey Baden Dan H. Barouch Galit Alter 《PLoS pathogens》2016,12(3)
Antibody effector functions, such as antibody-dependent cellular cytotoxicity, complement deposition, and antibody-dependent phagocytosis, play a critical role in immunity against multiple pathogens, particularly in the absence of neutralizing activity. Two modifications to the IgG constant domain (Fc domain) regulate antibody functionality: changes in antibody subclass and changes in a single N-linked glycan located in the CH2 domain of the IgG Fc. Together, these modifications provide a specific set of instructions to the innate immune system to direct the elimination of antibody-bound antigens. While it is clear that subclass selection is actively regulated during the course of natural infection, it is unclear whether antibody glycosylation can be tuned, in a signal-specific or pathogen-specific manner. Here, we show that antibody glycosylation is determined in an antigen- and pathogen-specific manner during HIV infection. Moreover, while dramatic differences exist in bulk IgG glycosylation among individuals in distinct geographical locations, immunization is able to overcome these differences and elicit antigen-specific antibodies with similar antibody glycosylation patterns. Additionally, distinct vaccine regimens induced different antigen-specific IgG glycosylation profiles, suggesting that antibody glycosylation is not only programmable but can be manipulated via the delivery of distinct inflammatory signals during B cell priming. These data strongly suggest that the immune system naturally drives antibody glycosylation in an antigen-specific manner and highlights a promising means by which next-generation therapeutics and vaccines can harness the antiviral activity of the innate immune system via directed alterations in antibody glycosylation in vivo. 相似文献
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P P Bini B Floris P Nuvole S Pau M T Zedda 《Bollettino della Società italiana di biologia sperimentale》1989,65(9):831-837
Some hematological and hematochemical parameters in eight herring gulls (Larus argentatus) and in six buzzards (Buteo buteo) were checked. The buzzards were fed with ovine meat exclusively, while the herring gulls were fed with fish and ovine meat. Considerable differences between the two species were noted, particularly as far as the hematological and lipidic parameters are concerned. These differences are probably related to the aquatic life of the herring gull. 相似文献
85.
Feedback effects of ovarian steroids on the hypothalamic-hypophyseal axis in the rabbit 总被引:1,自引:0,他引:1
The feedback effects of two ovarian steroids, estradiol-17 beta (E2) and 20 alpha-hydroxypregn-4-en-3-one (20 alpha OH), were examined in both intact (INT) and ovariectomized (OVEX) does. We measured steroid-induced alterations in endogenous gonadotropin-releasing hormone (GnRH) from sequential 10-min samples of hypothalamic perfusates, simultaneous changes in peripheral plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the modification of pituitary responsiveness, i.e., increments in plasma LH (delta LH) and plasma FSH (delta FSH), after 50 ng, 250 ng, and 1 microgram of exogenous GnRH in individual does of 6 treatment groups. The groups were: INT does, OVEX does, OVEX does receiving either one (1 E2) or two (2 E2) E2-filled Silastic capsules, OVEX does receiving a 20 alpha OH-filled capsule (20 alpha OH), and OVEX does receiving both capsules of E2 and 20 alpha OH (1 E2 + 20 alpha OH). Ovariectomy enhanced the pulsatile release of hypothalamic GnRH and pituitary LH and FSH, and increased the LH response (delta LH) to exogenous GnRH (OVEX vs. INT, p less than 0.05). Replacement of E2 at the time of ovariectomy prevented the increased GnRH and gonadotropin secretion as well as the enhanced delta LH that were observed in untreated OVEX does. The release of hypothalamic GnRH in the 20 alpha OH group was lower (p less than 0.05) than that in the OVEX group and not different from that in the INT group. The release of pituitary LH and FSH and the delta LH in the 20 alpha OH group was not different from that in the OVEX group, but these parameters were greater (p less than 0.05) than those in the INT group. The hypothalamic GnRH pulse frequency in the 1 E2 + 20 alpha OH group was lower (p less than 0.05) than that in either the 1 E2 or the 20 alpha OH group, but the delta LH in the 1 E2 + 20 alpha OH group was not different from that in either the 1 E2 or the 20 alpha OH group. The highest dose (1 microgram) of exogenous GnRH stimulated a modest increase in FSH in the OVEX, 20 alpha OH, 1 E2 + 20 alpha OH, and 1 E2 groups; but a steroid effect on delta FSH among these 4 groups was not apparent.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Significance of the recognition of certain antigenic regions on the human thyroglobulin molecule by natural autoantibodies from healthy subjects 总被引:3,自引:0,他引:3
M Bouanani M Piechaczyk B Pau M Bastide 《Journal of immunology (Baltimore, Md. : 1950)》1989,143(4):1129-1132
We have evaluated the epitope specificity of natural antihuman thyroglobulin (hTg) autoantibodies (aAb) in the plasma of healthy individuals. By an indirect ELISA technique, we selected 56 plasma samples with high anti-hTg antibody activity and used the IgG fraction isolated from these plasma to study the antigenic domains on the hTg molecule recognized by the natural anti-hTg aAb. A panel of 15 mAb, coupled to alkaline phosphatase and recognizing six regions (I to VI) on the hTg molecule, served to identify the domains recognized by the natural anti-hTg aAb using a competitive ELISA procedure. A total of 26 of the IgG fractions was found to interact with at least one of the regions defined by our battery of mAb. Region V was recognized by the majority of the IgG fractions. Interestingly, region II was rarely recognized by the same IgG fraction that reacted with region V. Inasmuch as we have previously shown that region II is mainly recognized by aAb in the serum of subjects with various thyroid disorders, we propose that recognition of region V reflects the normal physiologic state of the immune system with respect to the hTg molecule. 相似文献
89.
Norma Fàbregas Pau Formosa-Jordan Ana Confraria Riccardo Siligato Jose M. Alonso Ranjan Swarup Malcolm J. Bennett Ari Pekka M?h?nen Ana I. Ca?o-Delgado Marta Iba?es 《PLoS genetics》2015,11(4)
Auxin is an essential hormone for plant growth and development. Auxin influx carriers AUX1/LAX transport auxin into the cell, while auxin efflux carriers PIN pump it out of the cell. It is well established that efflux carriers play an important role in the shoot vascular patterning, yet the contribution of influx carriers to the shoot vasculature remains unknown. Here, we combined theoretical and experimental approaches to decipher the role of auxin influx carriers in the patterning and differentiation of vascular tissues in the Arabidopsis inflorescence stem. Our theoretical analysis predicts that influx carriers facilitate periodic patterning and modulate the periodicity of auxin maxima. In agreement, we observed fewer and more spaced vascular bundles in quadruple mutants plants of the auxin influx carriers aux1lax1lax2lax3. Furthermore, we show AUX1/LAX carriers promote xylem differentiation in both the shoot and the root tissues. Influx carriers increase cytoplasmic auxin signaling, and thereby differentiation. In addition to this cytoplasmic role of auxin, our computational simulations propose a role for extracellular auxin as an inhibitor of xylem differentiation. Altogether, our study shows that auxin influx carriers AUX1/LAX regulate vascular patterning and differentiation in plants. 相似文献