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排序方式: 共有224条查询结果,搜索用时 137 毫秒
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LÊDA REGIS 《Invertebrate reproduction & development.》2013,57(3):187-195
The number of eggs produced by Triatoma infestans is determined by the amount of blood ingested; the formation of one egg requires 16 mg blood. An exogenous supply of juvenile hormone, provided by the implantation of extra corpora aliata, increases egg production per unit of blood ingested. The corpus allatum is therefore implicated in the relationship between nutrition and fecundity. The rhythm of egg production is regulated by the nutritional state of the adult female: when the females are fed at frequent intervals, egg production becomes regular and continuous. This calls into question previous interpretations of egg-laying rhythms in the Triatominae as cyclic. 相似文献
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In the Savio strain of Locusta migratoria an imaginai diapause is induced by long daylength. In diapausing females, the haemolymph level of juvenile hormone (JH) was undetectable during the first 3-wk of imaginai life and later rose only slightly to about 20 ng/JH3IR per ml. Only peripheral cells of the corpora aliata (CA) were active. In nondiapausing animals, or after the termination of diapause, the JH level was high (140–200 ng/ml) and the ultrastructure of the gland exhibited signs of activity. CA severance in 3-wk-old diapausing females terminated diapause as a result of activation of the CA. CA disconnection in the fifth larval instar or at the imaginai moult in long daylength animals did not break diapause and the CA stayed inactive. The lateral cells of the protocerebrum exert a jdual effect: at the end of larval life they bring about CA maturation and render them active, whereas during the imaginai diapause they inhibit CA activity. The median neurosecretory cells of the pars intercerebralis support CA activity during vitellogenesis. 相似文献
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Kaczmarek MM Kowalczyk AE Waclawik A Schams D Ziecik AJ 《Molecular reproduction and development》2007,74(6):730-739
The present study was undertaken to determine the expression of vascular endothelial growth factor (VEGF) and its receptors, fms-like tyrosine kinase (Flt-1) and fetal liver kinase-1/kinase insert domain-containing receptor (Flk-1/KDR), in the porcine corpus luteum (CL) during the estrous cycle and early pregnancy. Immunohistochemical studies localized proteins of VEGF ligand-receptor system in the cytoplasm of luteal cells and in some blood vessels. Western blot analysis revealed significantly higher levels of VEGF protein during early and mid-luteal phase (vs. late luteal phase; P<0.001 and P<0.01, respectively). Quantification of VEGF mRNA in the CL showed increased mRNA levels during entire luteal phase (vs. Days 16-17; P<0.05). Expression of Flt-1 protein remained high during luteal phase (P<0.001), but the mRNA levels tended to increase from the early to the late luteal phase. Elevated protein expression of Flk-1/KDR was found in the mid-luteal phase (vs. Days 16-17; P<0.05). However, induction of Flk-1/KDR mRNA expression occurred earlier, in early luteal phase. The lowest VEGF, Flt-1 and Flk-1/KDR mRNA and protein levels were observed in regressed CL (P<0.001). During pregnancy, VEGF, Flt-1 and Flk-1/KDR mRNA and protein expression was comparable to the mid-luteal phase. In conclusion, the present study has demonstrated dynamic expression of VEGF and its receptors in the porcine CL during the estrous cycle and early pregnancy. These data suggest that the VEGF ligand-receptor system may play an important role in the development and maintenance of the CL in pigs. 相似文献
66.
Dong Ouyang Ruyi Li Yaxian Li Xueqiong Zhu 《Journal of cellular biochemistry》2019,120(10):18465-18477
Current research indicate that long noncoding RNAs (lncRNAs) are associated with the progression of various cancers and can be used as prognostic biomarkers. This study aims to construct a prognostic lncRNA signature for the risk assessment of Uterine corpus endometrial carcinoma (UCEC). The RNA-Seq expression profile and corresponding clinical data of UCEC patients obtained from The Cancer Genome Atlas database. First, some prognosis-related lncRNAs were obtained by univariate Cox analysis. The minimum absolute contraction and selection operator (LASSO) regression and the Cox proportional hazard regression method were used to further identify the lncRNA prognostic model. Finally, seven lncRNAs (AC110491.1, AL451137.1, AC005381.1, AC103563.2, AC007422.2, AC108025.2, and MIR7-3HG) were identified as potential prognostic factors. According to the model constructed by the above analysis, the risk score of each UCEC patient was calculated, and the patients were classified into high and low-risk groups. The low-risk group had significant survival benefits. Moreover, we constructed a nomogram that incorporated independent prognostic factors (age, tumor stage, tumor grade, and risk score). The c-index value for evaluating the predictive nomogram model was 0.801. The area under the curve was 0.797 (3-year survival). The calibration curve also showed that there was a satisfactory agreement between the predicted and observed values in the probability of 1-, 3-, and 5-year overall survival. On the basis of the coexpression relationship, we established a coexpression network of lncRNA-messenger RNA (mRNA) of the 7-lncRNA. The Kyoto Encyclopedia of Genes and Genomes analysis of the coexpressing mRNAs showed that the main pathways related to the 7-lncRNA signature were neuroactive ligand-receptor interaction, serotonergic synapse, and gastric cancer pathway. Therefore, our study revealed that the 7-lncRNA could be used to predict the prognosis of UCEC and for postoperative treatment and follow-up. 相似文献
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Neuron-specific enolase (NSE) is the key molecular marker for diffuse neuroendocrine system (DNES) cells, its expression in the pregnant corpus luteum (CL) of dairy goats was studied by the immunofluorescence method and the ultra structural characteristics of luteal cells were detected by the electron microscopy to identify the existence of DNES cells in the pregnant CL of dairy goats. Besides, the coding sequence of dairy goats NSE gene was cloned and its biological information was analyzed. Results revealed that NSE immunopositive cells exhibited widespread cytoplasmic staining throughout the whole pregnant CL. In addition, these cells showed typical characteristics of DNES cells in the electron microscopy. These results suggested that many DNES cells exist in the pregnant CL of dairy goats. Meanwhile, we identified the coding sequence of dairy goats NSE (GenBank Accession No. JN887466). Its nucleotide sequence homology was found to be 97.9%, 89.3%, 90% and 92.6%, respectively, compared with that of Bos taurus, Rattus norvegicus, Mus musculus and Homo sapiens, while the amino acid sequence homology was 99.1%, 97%, 97.2% and 98.2% respectively. These results first showed that the functional amino acids coded by the NSE gene were highly conserved in Caprine, B. taurus, R. norvegicus, M. musculus and H. sapiens. It was implied that the gene NSE in dairy goats had close homology to that of NSE of other species. Our findings demonstrated the possible existence of DNES cells in pregnant CL, providing new clue for further understanding of interactions between the neuroendocrine and reproductive systems. Characterization of gene sequence of dairy goats NSE will enable us to synthesize interference RNA for further study on the role of NSE on the formation, function and apoptosis of pregnant CL in dairy goats. 相似文献
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van Diepen HA Pansier J Oude Wesselink P van Drie A van Duin M Mulders S 《Journal of medical primatology》2012,41(1):18-23
Background In women, different events of folliculogenesis can be measured and evaluated using ultrasound (US) technology. The availability of a non‐invasive translational non‐human primate model to study these processes would represent a major contribution to further advance R&D efforts toward novel therapies in assisted reproduction. Methods In our study, follicular growth and ovulation was measured in six cyclic Cynomolgus monkeys using abdominal Doppler US. Results The mean follicular diameter on cycle day ?6 (cycle day 0 = day of ovulation) was 3.7 mm that increased to 6.8 mm on cycle day ?1. After ovulation, the mean diameter decreased to 4.6 mm, confirming ovulation. The mean percentage of follicular size reduction after ovulation was 31%. Conclusion Ultrasonography in combination with color‐flow Doppler imaging was shown to be a useful, non‐invasive translational method to measure ovarian follicular growth and occurrence and timing of follicular rupture in Cynomolgus monkeys. 相似文献