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991.
Studies using mounts have an inherently nested error structure; calibration and standardization should use the appropriate procedures and statistics. One example is that individual mount differences are nested within morphological factors related to species, age, or gender; without replication, mount differences may be confused with differences due to morphology. Also, the sensitivity of mounts to orientation to wind or sun is nested within mount; without replication, inadvertent variation in mount positioning may be confused with differences among mounts. Data on heat loss from a of 1-day-old mallard duckling mount are used to illustrate orientation sensitivity. 相似文献
992.
Younes SA Trautmann L Yassine-Diab B Kalfayan LH Kernaleguen AE Cameron TO Boulassel R Stern LJ Routy JP Grossman Z Dumont AR Sekaly RP 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(2):788-797
The impact of exposure to Ag on the development and maintenance of human CD4(+) memory T cells in general and HIV infection in particular is partially understood. In this study, we measured HIV-specific CD4(+) T cell proliferative responses against HIV proteins and derived peptides one year after highly active antiretroviral therapy initiation in 39 HIV-infected patients who initiated therapy at different times following infection. We show that a brief exposure to HIV of <1 month does not allow the generation of significant detectable frequencies of HIV-specific CD4(+) memory T cells. Patients having prolonged cumulative exposure to high viral load due to therapy failures also demonstrated limited HIV-specific CD4(+) T cell responses. In contrast, patients exposed to significant levels of virus for periods ranging from 3 to 18 mo showed brisk and broad HIV-specific CD4(+) T cell responses 1 year following the onset of therapy intervention. We also demonstrate that the nadir CD4(+) T cell count before therapy initiation correlated positively with the breadth and magnitude of these responses. Our findings indicate that the loss of proliferative HIV-specific CD4(+) T cell responses is associated with the systemic progression of the disease and that a brief exposure to HIV does not allow the establishment of detectable frequencies of HIV-specific memory CD4(+) T cells. 相似文献
993.
Patel SN Lu Z Ayi K Serghides L Gowda DC Kain KC 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(6):3954-3961
CD36 is a scavenger receptor that has been implicated in malaria pathogenesis as well as innate defense against blood-stage infection. Inflammatory responses to Plasmodium falciparum GPI (pfGPI) anchors are believed to play an important role in innate immune response to malaria. We investigated the role of CD36 in pfGPI-induced MAPK activation and proinflammatory cytokine secretion. Furthermore, we explored the role of this receptor in an experimental model of acute malaria in vivo. We demonstrate that ERK1/2, JNK, p38, and c-Jun became phosphorylated in pfGPI-stimulated macrophages. In contrast, pfGPI-induced phosphorylation of JNK, ERK1/2, and c-Jun was reduced in Cd36(-/-) macrophages and Cd36(-/-) macrophages secreted significantly less TNF-alpha in response to pfGPI than their wild-type counterparts. In addition, we demonstrate a role for CD36 in innate immune response to malaria in vivo. Compared with wild-type mice, Cd36(-/-) mice experienced more severe and fatal malaria when challenged with Plasmodium chabaudi chabaudi AS. Cd36(-/-) mice displayed a combined defect in cytokine induction and parasite clearance with a dysregulated cytokine response to infection, earlier peak parasitemias, higher parasite densities, and higher mortality rates than wild-type mice. These results provide direct evidence that pfGPI induces TNF-alpha secretion in a CD36-dependent manner and support a role for CD36 in modulating host cytokine response and innate control of acute blood-stage malaria infection in vivo. 相似文献
994.
Hermaphroditism is rare and phylogenically in decline among animal species. The evolutionary basis for this development is not well understood. This paper focusses on self-incompatible simultaneous hermaphroditism in animals. It proposes that such hermaphroditism is not stable in sufficiently heterogeneous populations, suggesting a possible reason for why hermaphroditism is rare among evolved animal species. The argument turns on the Bateman principle, namely that male reproductive success (RS) is limited by partner availability, while female RS is not. We show that: low-quality individuals do better if female; secondary sexual differentiation may be important for understanding the existence of males; and that hermaphroditic mating is reciprocal. Reciprocity may be key to understanding promiscuity and attendant phenomena such as cryptic female choice, sperm competition and love darts-common features of hermaphroditic mating. We also argue that hermaphrodites are especially vulnerable to male violence, suggesting a reason for the rarity of trioecy. Finally, we propose that external fertilization, and the scope for streaking, may be one reason fish are the only simultaneously hermaphroditic vertebrates. 相似文献
995.
996.
Only recently, the fundamental role of regulatory RNAs in prokaryotes and eukaryotes has been appreciated. We developed a
pipeline from bioinformatic prediction to experimental validation of new RNA thermometers. Known RNA thermometers are located
in the 5′-untranslated region of certain heat shock or virulence genes and control translation by temperature-dependent base
pairing of the ribosome binding site. We established the searchable database RNA-SURIBA (Structures of Untranslated Regions
In BActeria). A structure-based search pattern reliably recognizes known RNA thermometers and predicts related structures
upstream of annotated genes in complete genome sequences. The known ROSE1 (Repression Of heat Shock gene Expression) thermometer and several other functional ROSE-like elements were correctly predicted.
For further investigation, we chose a new candidate upstream of the phage shock gene D (pspD) in the pspABCDE operon of E. coli. We established a new reporter gene system that measures translational control at heat shock temperatures and we demonstrated
that the upstream region of pspD does not confer temperature control to the phage shock gene. However, translational efficiency was modulated by a point mutation
stabilizing the predicted hairpin. Testing other candidates by this structure prediction and validation process will lead
to new insights into the requirements for biologically active RNA thermometers. The database is available on .
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
997.
Lynn Boschloo Ella Bekhuis Erica S. Weitz Mirjam Reijnders Robert J. DeRubeis Sona Dimidjian David L. Dunner Boadie W. Dunlop Ulrich Hegerl Steven D. Hollon Robin B. Jarrett Sidney H. Kennedy Jeanne Miranda David C. Mohr Anne D. Simons Gordon Parker Frank Petrak Stephan Herpertz Lena C. Quilty A. John Rush Zindel V. Segal Jeffrey R. Vittengl Robert A. Schoevers Pim Cuijpers 《World psychiatry》2019,18(2):183-191
A recent individual patient data meta‐analysis showed that antidepressant medication is slightly more efficacious than cognitive behavioral therapy (CBT) in reducing overall depression severity in patients with a DSM‐defined depressive disorder. We used an update of that dataset, based on seventeen randomized clinical trials, to examine the comparative efficacy of antidepressant medication vs. CBT in more detail by focusing on individual depressive symptoms as assessed with the 17‐item Hamilton Rating Scale for Depression. Five symptoms (i.e., “depressed mood” , “feelings of guilt” , “suicidal thoughts” , “psychic anxiety” and “general somatic symptoms”) showed larger improvements in the medication compared to the CBT condition (effect sizes ranging from .13 to .16), whereas no differences were found for the twelve other symptoms. In addition, network estimation techniques revealed that all effects, except that on “depressed mood” , were direct and could not be explained by any of the other direct or indirect treatment effects. Exploratory analyses showed that information about the symptom‐specific efficacy could help in identifying those patients who, based on their pre‐treatment symptomatology, are likely to benefit more from antidepressant medication than from CBT (effect size of .30) versus those for whom both treatments are likely to be equally efficacious. Overall, our symptom‐oriented approach results in a more thorough evaluation of the efficacy of antidepressant medication over CBT and shows potential in “precision psychiatry” . 相似文献
998.
Henrik Persson Wojciech Potrzebowski Katarzyna Potrzebowska Lena M. Svensson 《Journal of biophotonics》2019,12(3)
Localization microscopy methods like Stochastic Optical Reconstruction Microscopy (STORM) are very well suited for exploring clustering of proteins, as the data inherently provide a list of molecular coordinates. Here we use state‐of‐art cluster analysis algorithms (DBSCAN) to explore the clustering behaviour of different affinity forms of the integrin LFA‐1. It has been suggested that LFA‐1 may form clusters, in order to increase the avidity to ICAM‐1. However, this hypothesis still seems to be controversial. In this study, we found, variations in clustering behaviour among the different affinity forms of LFA‐1 in migrating T‐cells. We found that panLFA‐1 is located in clusters throughout the polarised cell on ICAM‐1, with an increased density of molecules and clusters in the mid area and rear of the cell, whereas the intermediate and high affinity form of LFA‐1 showed an increased number in the mid area of a migrating cell and the high affinity form of LFA‐1 in the front and rear. Together, these data suggest that, in addition to LFA‐1 conformation, protein clustering might play a role in controlling cell‐substrate adhesion on ICAM‐1.By applying the cluster analysis algorithm DBSCAN to localization microscopy data, integrin clusters could be identified and different cluster parameters could be quantified. 相似文献
999.
Ailisa Blum Aurélie H. Benfield Jens L. Sørensen Mikkel R. Nielsen Simone Bachleitner Lena Studt Giovanni Beccari Lorenzo Covarelli Jacqueline Batley Donald M. Gardiner 《Fungal biology》2019,123(3):255-266
Fusarium pseudograminearum is an agronomically important fungus, which infects many crop plants, including wheat, where it causes Fusarium crown rot. Like many other fungi, the Fusarium genus produces a wide range of secondary metabolites of which only few have been characterized. Recently a novel gene cluster was discovered in F. pseudograminearum, which encodes production of cytokinin-like metabolites collectively named Fusarium cytokinins. They are structurally similar to plant cytokinins and can activate cytokinin signalling in vitro and in planta. Here, the regulation of Fusarium cytokinin production was analysed in vitro. This revealed that, similar to deoxynivalenol (DON) production in Fusarium graminearum, cytokinin production can be induced in vitro by specific nitrogen sources in a pH-dependent manner. DON production was also induced in both F. graminearum and F. pseudograminearum in cytokinin-inducing conditions. In addition, microscopic analyses of wheat seedlings infected with a F. pseudograminearum cytokinin reporter strain showed that the fungus specifically induces its cytokinin production in hyphae, which are in close association with the plant, suggestive of a function of Fusarium cytokinins during infection. 相似文献
1000.
Riem Gawish Tanja Bulat Mario Biaggio Caroline Lassnig Zsuzsanna Bago-Horvath Sabine Macho-Maschler Andrea Poelzl Natalija Simonović Michaela Prchal-Murphy Rita Rom Lena Amenitsch Luca Ferrarese Juliana Kornhoff Therese Lederer Jasmin Svinka Robert Eferl Markus Bosmann Ulrich Kalinke Birgit Strobl 《Cell reports》2019,26(9):2394-2406.e5