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101.
Benach J Swaminathan SS Tamayo R Handelman SK Folta-Stogniew E Ramos JE Forouhar F Neely H Seetharaman J Camilli A Hunt JF 《The EMBO journal》2007,26(24):5153-5166
The second messenger cyclic diguanylate (c-di-GMP) controls the transition between motile and sessile growth in eubacteria, but little is known about the proteins that sense its concentration. Bioinformatics analyses suggested that PilZ domains bind c-di-GMP and allosterically modulate effector pathways. We have determined a 1.9 A crystal structure of c-di-GMP bound to VCA0042/PlzD, a PilZ domain-containing protein from Vibrio cholerae. Either this protein or another specific PilZ domain-containing protein is required for V. cholerae to efficiently infect mice. VCA0042/PlzD comprises a C-terminal PilZ domain plus an N-terminal domain with a similar beta-barrel fold. C-di-GMP contacts seven of the nine strongly conserved residues in the PilZ domain, including three in a seven-residue long N-terminal loop that undergoes a conformational switch as it wraps around c-di-GMP. This switch brings the PilZ domain into close apposition with the N-terminal domain, forming a new allosteric interaction surface that spans these domains and the c-di-GMP at their interface. The very small size of the N-terminal conformational switch is likely to explain the facile evolutionary diversification of the PilZ domain. 相似文献
102.
In many cell types translation can be regulated by an expression of the translation initiation factor. Eukaryotic translation
initiation factor eIF4E, which binds to the 5′ cap structure of mRNA, plays an important role in translation regulation and
it has been suggested that it is implicated in increased protein synthesis promoted by growth factors. In this study the effects
of nerve growth factor (NGF) infusion into the cerebrospinal fluid (CSF) on eIF4E expression and phosphorylation in mouse
brain tissue have been investigated. We investigated NGF as it is one of the most important growth factors and it is an important
factor in cerebral cortical development, stimulating neuronal precursor proliferation. eIF4E level is also increased in response
to infusion of NGF into the CSF. The present study shows that eIF4E is phosphorylated in the brain tissues treated with NGF.
It is concluded that NGF regulates protein synthesis in the nervous tissue by enhancing expression and phosphorylation of
eIF4E. 相似文献
103.
Andreas Fottner Farhad Mazoochian Wolfgang Plitz Christoph von Schulze Pellengahr Christoph Birkenmaier Volkmar Jansson 《Biomedizinische Technik》2007,52(5):346-350
The aim of our study was to develop a femoral component for total hip arthroplasty that would exclusively anchor in the metaphysis of the femoral neck. To forego trochanteric fixation, the load needs to be transferred to the metaphysis at as many points as possible. A computer simulation model suggested that an implant with a central cylinder and 16 rods aligned along a thread would be the preferable solution. To evaluate primary implantation stability, 14 fresh frozen cadaver femora were used. A special instrument set was developed to allow for centered implantation of the prosthesis without the need to dissect the greater trochanter. For our tests, we used two prototype implants: one made from titanium and the other from a CoCrMo alloy. For the measurement of micromotions at the medial proximal femur, sinusoid dynamic loading with a force between 300 N and 1700 N and a frequency of 1 Hz was employed. In a neutral position of 16 degrees adduction and 9 degrees antetorsion, the average micromotions measured were 119 microm. Despite these convincing in vitro results with regards to primary stability, circular cut-out of the implant, followed by aseptic osteonecrosis, loosening might still occur in a clinical situation. Animal experiments are therefore required to further evaluate this new implant design. 相似文献
104.
105.
106.
Mohammadian Mehdi Salami Maryam Alavi Farhad Momen Shima Emam-Djomeh Zahra Moosavi-Movahedi Ali Akbar 《Food biophysics》2019,14(4):425-436
Food Biophysics - In this research, gum Arabic (GA) and whey protein nanofibrils (WPN) were employed for the encapsulation of curcumin as a bioactive compound with low water solubility through the... 相似文献
107.
108.
Hisham Ali Waggiallah Faris Q. Alenzi Abdulkarim S. Bin Shaya Ahmed Hattan Hattan Yousif Mohammed Elmosaad Maher M. Alenazi 《Saudi Journal of Biological Sciences》2021,28(8):4699-4703
Unexpected antibodies, also called irregular antibodies, are not known to exist in a person's serum before testing. This research aims to assess the prevalence of unexpected antibodies and their correlation with several clinical conditions. This cross-sectional prospective study, undertaken from June 2019 to June 2020, included ABO, Rh grouping, cross-matching, and antibody screening. Antibody identification was performed only on patients who tested positive in the screening test. From a total of 9764 participants who were screened for unexpected antibodies, 107 (1.1%) tested positive. The Rh blood group system antibodies were the most frequent, particularly anti-D. There was also a significant correlation between the unexpected antibodies and history of transfusion, pregnancy, and autoimmune diseases as P ≤ 0.05. The most prominent unexpected antibodies in the study belong to the Rh system (Anti-D). Moreover, as a result of the strong correlation between the unexpected antibodies as well as the history of transfusion, pregnancy, and autoimmune diseases, the highest safety criteria must be followed during the transfusion of blood to patients with these clinical conditions. 相似文献
109.
Nasim Babaknejad Fatemeh Sayehmiri Kourosh Sayehmiri Parya Rahimifar Somaye Bahrami Ali Delpesheh Farhad Hemati Sajjad Alizadeh 《Biological trace element research》2014,159(1-3):1-7
Breast cancer is the most common cancer type. In several studies, hints have been provided that there is a correlation between selenium deficiency and the incidence of breast cancer. Findings of these published reports are, however, inconsistent. This study serves as a pioneering study aiming at combining the results of studies using a meta-analytic method. A total of 16 articles published between 1980 and 2012 worldwide were selected through searching PubMed, Scopus, and Google scholar databases, and the information were analyzed using a meta-analytic method [random effects model]. I 2 statistics were used to examine heterogeneity. The information was then analyzed by STATA version 12. In this study, due to the non-uniform methods used to measure selenium concentrations, selenium levels were measured in the various subgroups in both case and control groups. There were significant correlations between selenium concentration and breast cancer [P?<?0.05]. Hence, the mean risk differentiating criteria were estimated to be 0.63 [95 % confidence interval [95% CI] 0.93 to 0.32] in serum and toenails. Subgroup analysis showed that the value in toenails was ?0.07 [95% CI ?0.16 to 0.03] and in serum ?1.04 [95% CI 1.71 to ?0.38]. In studies in which selenium concentrations were measured in serum, a significant correlation was observed between selenium concentration and breast cancer. In contrast, in studies in which selenium concentration was measured in toenails, the correlation was not significant. Therefore, the selenium concentration can be used as one predictor for breast cancer. 相似文献
110.
Farhad Farhoudi Hossein Allahyari Seyed Mohammad Tabadkani Majid Gholizadeh 《Journal of Insect Behavior》2014,27(6):776-785
Color polymorphism in insects as well as factors contributing to its occurrence and maintenance have been of a great interest. Pea aphid (A. pisum) exhibits a noteworthy color polymorphism which occurs as red and green. The preference of the predatory gall midge Aphidoletes aphidimyza (Rondani) for the two color morphs of pea aphid at two life stages (adult and second instar) was investigated. Red adults, red nymphs, green adults, and green nymphs were offered to the larvae of the predator in different sets. The larvae attacked red aphids more than green ones of a same size. But whenever adults were offered along with nymphs, the nymphs experienced significantly more attacks. Although visual cues could result in more predation on red aphids, our findings showed that the size of aphids was the more important factor. The results showed that previous findings, suggesting more predation on the red morph, are valid when the same size of aphids is used. The ovipositing females exhibited no differences in oviposition choice between stalks infested with either of two colors. 相似文献