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61.
GATA-3 and the regulation of the mammary luminal cell fate 总被引:3,自引:0,他引:3
62.
Green fluorescent protein (GFP)-tagged actin was used to investigate the distribution and function of actin in Tetrahymena. A strain that expresses both GFP-actin and endogenous actin was developed by transformation of Tetrahymena thermophila with a ribosomal DNA-based replicative vector. Confocal microscopy of living cells and immunogold electron microscopy confirmed localization of GFP-actin to basal bodies and the contractile ring. Incorporation of the fusion protein into these and other actin-related structures correlated with severe impairment of macronuclear elongation and cytokinesis. At 30 degrees C macronuclear elongation failed to occur in 25% of the transformants despite completion of micronuclear division. At 20 degrees C macronuclear elongation failed to occur in 2% of the population. Arrest of cytokinesis coincided with failure of macronuclear elongation. Arrested cells developed into homopolar doublets with two sets of oral structures. This study indicates a requirement for actin in nuclear elongation and cytokinesis. Although GFP-actin can interfere with the functioning of actin-containing structures, the GFP-actin transformant strain can be used to monitor actin distribution and dynamics and is therefore an important new tool for further studies of Tetrahymena actin. 相似文献
63.
Dual camera stereo photogrammetry (DCSP) was applied to investigate the leaflet motion of bioprosthetic heart valves (BHVs) in a physiologic pulse flow loop (PFL). A 25-mm bovine pericardial valve was installed in the aortic valve position of the PFL, which was operated at a pulse rate of 70 beats/min and a cardiac output of 5 l/min. The systolic/diastolic aortic pressure was maintained at 120/80 mmHg to mimic the physiologic load experienced by the aortic valve. The leaflet of the test valve was marked with 80 India ink dots to form a fan-shaped matrix. From the acquired image sequences, 3-D coordinates of the marker matrix were derived and hence the surface contour, local mean and Gaussian curvatures at each opening and closing phase during one cardiac cycle were reconstructed. It is generally believed that the long-term failure rate of BHV is related to the uneven distribution of mechanical stresses occurring in the leaflet material during opening and closing. Unfortunately, a quantitative analysis of the leaflet motion under physiological conditions has not been reported. The newly developed technique permits frame-by-frame mapping of the leaflet surface, which is essential for dynamic analysis of stress-strain behavior in BHV. 相似文献
64.
Kobra Ahmadi Chashmi Omran Vali Ollah Ghasemi Ebrahimi Raheleh Moradi Hosein Abdosi Vahid 《Biology Bulletin》2022,49(5):476-484
Biology Bulletin - Light-emitting diodes (LEDs) can be used as a useful alternative to the in vitro culture of various plant species, which not only accelerates plantlet growth and development but... 相似文献
65.
Yaser Mansoori Zahra Zendehbad Alireza Askari Amin Kouhpayeh Javad Tavakkoly-Bazzaz Ziba Nariman-Saleh-Fam Milad Bastami Zahra Saadatian Behnam Mansoori Amin Yousefvand Hosein Mansoori Abdolreza Daraei 《Journal of cellular biochemistry》2019,120(6):9869-9876
Recently, it has been revealed that estrogen-related reproductive factors are linked with some early gene expression lesions associated with malignancy in clinically healthy breasts. Accordingly, the aim of the current study was to evaluate the association of expression levels of estrogen-related long noncoding RNAs (lncRNAs) upstream Eleanor (u-Eleanor) and HOX antisense intergenic RNA (HOTAIR) with the different patterns of reproductive factors in breast tissue of healthy women. The subjects of this study were 98 cancer-free women who had undergone cosmetic mammoplasty. The expression levels of u-Eleanor and HOTAIR were measured using quantitative real-time polymerase chain reaction. The results of the current study showed that the women without a history of breastfeeding had a high-level expression of u-Eleanor compared with the women with a breastfeeding duration greater than 6 to 24 months (P = 0.03) as well as the women with a breastfeeding duration of more than 24 months (P = 0.005). Furthermore, a higher expression of u-Eleanor was found in the women with a short breastfeeding duration for 1 to 6 months than that in the women with a breastfeeding duration of greater than 24 months (P = 0.02). In the same way, the results of correlation test (r = −0.258; P = 0.036) and multivariate regression model (β = −0.321; P = 0.023) are indicative of a significant relationship of elevated expression of u-Eleanor with decreasing breastfeeding duration in the women. These findings could be important to identify the molecular mechanisms behind the relationship between a lack or short duration of the breastfeeding and the risk of breast cancer, which has previously been reported by epidemiological studies. 相似文献
66.
Amir Ghasemi-Jangjoo Hosein Ghiasi 《Reports of Practical Oncology and Radiotherapy》2019,24(4):363-368
AimThe aim of this study was to design a safe bunker for an 18 MV linac in to configuration; primary barriers made from nanoparticle-containing concrete and pure concrete.BackgroundApplication of some nanoparticles in the shielding materials has been studied and it was shown that the presence of some nanoparticles improved radiation shielding properties.Materials and methodsSome percentage of different nanoparticles were modeled by the MCNP5 code of MC in the megavoltage radiotherapy treatment room's primary barriers. Other parts of the designed room, such as secondary barriers and maze door, were modeled as ordinary pure concrete. A safe bunker was designed according to the MC derived spectra at primary and secondary barriers location using a modeled and benchmarked 18 MV linac in free air. Then, the thickness of the required shielding materials for the door and also concrete for the walls and primary barriers were calculated separately.ResultsAccording to the results, required concrete thickness in primary and secondary barriers was reduced by around 0.8% compared to pure concrete application. Additionally, required lead and BPE decreased by 25% and 15%, respectively, due to primary barriers nanoparticles.ConclusionsIt was concluded that application of some nanoparticles in the shielding materials structures in megavoltage radiotherapy can make the shielding effective. 相似文献
67.
68.
Genomic characterization of the human heterotrimeric G protein alpha, beta, and gamma subunit genes.
Heterotrimeric guanine nucleotide binding proteins (G proteins) transduce extracellular signals received by transmembrane receptors to effector proteins. Each subunit of the G protein complex is encoded by a member of one of three corresponding gene families. Currently, 16 different members of the alpha subunit family, 5 different members of the beta subunit family, and 11 different members of the gamma subunit family have been described in mammals. Here we have identified and characterized Bacterial Artificial Chromosomes (BACs) containing the human homologs of each of the alpha, beta, and gamma subunit genes as well as a G alpha11 pseudogene and a previously undiscovered G gamma5-like gene. The gene structure and chromosome location of each gene was determined, as were the orientations of paired genes. These results provide greater insight into the evolution and functional diversity of the mammalian G protein subunit genes. 相似文献
69.
Purpose
Beta thalassemia is one of the most important hematic diseases all around the world and solving the problems caused by this abnormality is strongly dependent on precise detection and reliable screening of high-risk couples. The aim of our study was the investigation of sensitivity, specificity and accuracy of Tetra primer ARMS PCR method comparing with conventional ARMS PCR, based on sequencing technique outcomes for genotyping of IVS-II-I mutation in beta thalassemia patients.Methods
Fifty seven samples including two homozygote, 49 heterozygote and 6 normal specimens were analyzed by Tetra primer ARMS PCR and conventional ARMS PCR methods. DNA was extracted by the standard method of salting out for leukocyte genomic DNA extraction of blood specimens and a high pure PCR template preparation kit was used for DNA purification of CVS samples. The results obtained by Tetra primer ARMS PCR and conventional ARMS PCR methods were compared with gold standard technique, i.e. sequencing.Results
All three parameters including specificity, sensitivity and accuracy were 100% for Tetra primer ARMS PCR method, while they were 100%, 92.45% and 92.7% for conventional ARMS PCR technique respectively. Comparing with Tetra primer ARMS PCR which represented 100% agreement with sequencing method, conventional ARMS PCR technique only showed 47.1% agreement, because of 4 discordant results.Conclusion
Tetra primer ARMS PCR method is an almost reliable, sensitive and accurate technique and it is suggested that it can be used as a complementary method for diagnostic cases instead of conventional ARMS PCR method. This suggestion originated with perfect rate of agreement between outcomes of sequencing method, as a gold standard method of detecting the mutations, and Tetra primer ARMS PCR technique comparing with conventional ARMS PCR method. 相似文献70.