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991.
Rachel J. Dotson Seham M. Rabadi Elizabeth L. Westcott Stephen Bradley Sally V. Catlett Sukalyani Banik Jonathan A. Harton Chandra Shekhar Bakshi Meenakshi Malik 《The Journal of biological chemistry》2013,288(33):23844-23857
Francisella tularensis is an important human pathogen responsible for causing tularemia. F. tularensis has long been developed as a biological weapon and is now classified as a category A agent by the Centers for Disease Control because of its possible use as a bioterror agent. F. tularensis represses inflammasome; a cytosolic multi-protein complex that activates caspase-1 to produce proinflammatory cytokines IL-1β and IL-18. However, the Francisella factors and the mechanisms through which F. tularensis mediates these suppressive effects remain relatively unknown. Utilizing a mutant of F. tularensis in FTL_0325 gene, this study investigated the mechanisms of inflammasome repression by F. tularensis. We demonstrate that muted IL-1β and IL-18 responses generated in macrophages infected with F. tularensis live vaccine strain (LVS) or the virulent SchuS4 strain are due to a predominant suppressive effect on TLR2-dependent signal 1. Our results also demonstrate that FTL_0325 of F. tularensis impacts proIL-1β expression as early as 2 h post-infection and delays activation of AIM2 and NLRP3-inflammasomes in a TLR2-dependent fashion. An enhanced activation of caspase-1 and IL-1β observed in FTL_0325 mutant-infected macrophages at 24 h post-infection was independent of both AIM2 and NLRP3. Furthermore, F. tularensis LVS delayed pyroptotic cell death of the infected macrophages in an FTL_0325-dependent manner during the early stages of infection. In vivo studies in mice revealed that suppression of IL-1β by FTL_0325 early during infection facilitates the establishment of a fulminate infection by F. tularensis. Collectively, this study provides evidence that F. tularensis LVS represses inflammasome activation and that F. tularensis-encoded FTL_0325 mediates this effect. 相似文献
992.
Thomas E. Ichim Robert J. Harman Boris Minev Fabio Solano Doru T. Alexandrescu Xiang Hu Neil H. Riordan 《Cellular immunology》2010,264(1):7-17
Since the days of Medawar, the goal of therapeutic tolerogenesis has been a “Holy Grail” for immunologists. While knowledge of cellular and molecular mechanisms of this process has been increasing at an exponential rate, clinical progress has been minimal. To provide a mechanistic background of tolerogenesis, we overview common processes in the naturally occurring examples of: pregnancy, cancer, oral tolerance and anterior chamber associated immune deviation. The case is made that an easily accessible byproduct of plastic surgery, the adipose stromal vascular fraction, contains elements directly capable of promoting tolerogenesis such as T regulatory cells and inhibitory macrophages. The high content of mesenchymal and hematopoietic stem cells from this source provides the possibility of trophic/regenerative potential, which would augment tolerogenic processes by decreasing ongoing inflammation. We discuss the application of this autologous cell source in the context of rheumatoid arthritis, concluding with some practical examples of its applications. 相似文献
993.
本文采用电极阵列检测技术,在大鼠海马脑切片上诱导出稳定的癫痫样放电,分析、研究130 Hz的高频电刺激(high-frequency stimulation,HFS) CA3区时,海马切片在癫痫发作间期放电(inter-ictal discharges,IID)和发作期放电(ictal discharges,ID)的各项参数、癫痫样放电地起始位点、传播方向和传输速率以及各频段的功率谱密度.结果显示:高频电刺激可以有效地降低癫痫发作期的幅值、减少持续时间、增长潜伏时间、抑制癫痫样放电由IID向ID的转变等.提示高频电刺激抑制癫痫的作用机制是通过促进神经元之间的抑制性传输系统,并且抑制海马神经元之间的兴奋性连接,从而达到抑制效果. 相似文献
994.
摘要 目的:观察金复康口服液联合培美曲塞对非小细胞肺癌(NSCLC)患者免疫功能、肿瘤标志物及血清血管内皮生长因子(VEGF)、基质金属蛋白酶-9(MMP-9)水平的影响。方法:研究所涉及的60例NSCLC患者均为2017年8月至2020年8月期间我院收治的患者。根据随机数字表法将患者分为对照组和观察组,分别为30例。其中对照组给予培美曲塞联合顺铂化疗,观察组在对照组的基础上联合金复康口服液治疗,均以21 d为1个疗程,治疗4个疗程。对比两组治疗4个疗程后的疗效,对比两组治疗前、治疗4个疗程后的免疫功能、肿瘤标志物[细胞角质素片段抗原21-1 (CYFRA21-1)、糖类抗原125(CA125)、癌胚抗原(CEA)]及血清VEGF、MMP-9水平,对比两组毒副反应。结果:观察组的疾病控制率高于对照组(P<0.05)。治疗4个疗程后,两组CD3+、CD4+、CD4+/CD8+下降,但观察组高于对照组(P<0.05)。治疗4个疗程后,两组CA125、CYFRA21-1、CEA水平下降,且观察组低于对照组(P<0.05)。治疗4个疗程后,两组血清MMP-9、VEGF水平下降,且观察组低于对照组(P<0.05)。两组的毒副反应总发生率对比无差异(P>0.05)。结论:金复康口服液联合培美曲塞治疗NSCLC患者,可控制病灶,降低血清MMP-9、VEGF水平,减轻免疫抑制,安全有效。 相似文献
995.
G. B. Livshyts S. A. Kravchenko P. F. Tatarskyy I. A. Sudoma L. A. Livshits 《Cytology and Genetics》2008,42(4):272-277
The influence of FMR1, INHα1, NAT2, GSTT1 and GSTM1 genes mutations on ovarian function and their association with POF and “poor response” to exogenous GT after ovulation stimulation
were investigated. The carriers of Ala257Thr transition predominated in the studied “poor responders” group. In 1.6% POF patients
and 2.5% persons from “poor responders” group, but nobody from control group this transition combined with intermediate alleles
of FMR1 gene was observed. The frequency of deletion in GSTM1 gene in “poor responders” group was significantly higher (p = 0.01)
than in normal ovulatory control group. The frequency of Ser680Ser-Ala307Ala polymorphic genotype (22.2%) in “poor responders”
group was significantly higher (p = 0.028) than in normal-ovulatory control group (7.7%). The daily dosage of GT in intermediate
alleles of FMR1 gene carriers as well in patients with “slow acetylation” NAT2 genotype was significantly higher in comparison to patients without intermediate alleles and patients with “quick acetylation”
NAT2 genotype. Quantity of oocytes after stimulation ovulation in women with INHα1 gene Ala257Thr transition were significantly decreased in comparison to patients without such mutation. Further investigations
of these genes can play a major role in POF studying and modulation of ovarian response to exogenous GT.
Published in Ukrainian in Tsitologiya i Genetika, 2008, Vol. 42, No. 2, pp. 63–69.
The text was translated by the authors. 相似文献
996.
997.
Galactosephilic and mannosephilic lectins from Pseudomonas aeruginosa interact with Tetrahymena pyriformis GL. Specific adsorption of these lectins onto the Tetrahymena can be shown by inhibition of hemagglutination and by peroxidase binding to the cells mediated by the mannosephilic lectins. Interaction with the lectins does not agglutinate the protozoa even after immobilization by Na fluoride, formaldehyde, and glutaraldehyde or after papain treatment. However, inclusion of the lectins in the growth medium increases the growth rate of Tetrahymena and their presence in the medium supplied to starved ciliates increases phagocytosis of Chinese ink and vacuolization. 相似文献
998.
Magali Waelbroeck Patrick Robberecht Philippe De Neef Pierre Chatelain Jean Christophie 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,678(1):83-90
1. Vasoactive intestinal peptide (VIP) receptors were identified in crude rat hepatic membranes by 125I-labelled VIP binding and by the ability of VIP to stimulate adenylate cyclase activity. The specificity of these receptors was evaluated by the capacity of secretin, synthetic secretin analogues, and secretin fragments to inhibit 125I-labelled VIP binding and to stimulate adenylate cyclase. 2. The results were compatible with the existence of two classes of VIP binding sites that could be distinguised according to their affinity for VIP and their specificity. High-affinity sites were more specific for VIP as secretin was 175 times less potent than VIP for recognition of these sites while being only 33 times less potent than VIP for recognition of low-affinity sites. 3. Secretin analogues, monosubstituted in position 2, 3, 4, or 6 were less potent than secretin for adenylate cyclase stimulation as well as for the recognition of the two classes of receptors. [Val5]Secretin was more potent than secretin and appeared definitely more VIP-like than secretin; [Ala4, Val5]secretin were equipotent to secretin. 4. The fragment secretin (7–27) was unable to recognize VIP receptors and to stimulate adenylate cyclase. The substituted fragment [Gln[9,Asn15]secretin (5–27) recognized these receptors with weak potency but could not activate the enzyme. 相似文献
999.
Shoichi Fujita Jack Peisach 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,719(2):178-189
The reduction of the azo dye, amaranth, by rat liver microsomes is inhibited about 90% by carbon monoxide, suggesting that the reaction largely depends on cytochrome P-450. Reducing equivalents for this reaction are supplied by NADPH. This reaction is stimulated by riboflavin, FMN and FAD, as well as by methylviologen. A large fraction of the stimulated reaction is not blocked by CO, indicating that there is a pathway of electron transfer which is dependent of cytochrome P-450. Rat liver microsomes can reduce FAD, with reducing equivalents supplied by NADPH. The FADH2 thus produced is quickly oxidized by amaranth so that two FADH2 are oxidized for every amaranth reduced. The same stoichiometry is observed with photochemically prepared FADH2, formed in the absence of microsomes. 相似文献
1000.
《遗传学报》2020,47(9):547-561
Suppressive regulatory T cells (Treg cells) play a vital role in preventing autoimmunity and restraining excessive immune response to both self- and non-self-antigens. Studies on humans and mice show that the Forkhead box p3 (Foxp3) is a key regulatory gene for the development and function of Treg cells. In zebrafish, Treg cells have been identified by using foxp3a as a reliable marker. However, little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation. Here, we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development. We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis, while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis. More than 80% of foxp3a–/– mutants developed as subfertile males, and the rest of the mutants developed as fertile females with decreased ovulation. Further study revealed that foxp3a–/– mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females, which led to a dominance of later male development. Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a–/– mutants, abundant T cells and macrophages expand to disrupt an immunosuppressive milieu, resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males. Therefore, our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish. 相似文献