全文获取类型
收费全文 | 3818篇 |
免费 | 218篇 |
国内免费 | 2篇 |
出版年
2022年 | 16篇 |
2021年 | 32篇 |
2020年 | 17篇 |
2019年 | 37篇 |
2018年 | 49篇 |
2017年 | 43篇 |
2016年 | 72篇 |
2015年 | 117篇 |
2014年 | 140篇 |
2013年 | 235篇 |
2012年 | 230篇 |
2011年 | 217篇 |
2010年 | 141篇 |
2009年 | 158篇 |
2008年 | 204篇 |
2007年 | 241篇 |
2006年 | 238篇 |
2005年 | 223篇 |
2004年 | 202篇 |
2003年 | 212篇 |
2002年 | 249篇 |
2001年 | 86篇 |
2000年 | 66篇 |
1999年 | 70篇 |
1998年 | 54篇 |
1997年 | 43篇 |
1996年 | 41篇 |
1995年 | 35篇 |
1994年 | 31篇 |
1993年 | 40篇 |
1992年 | 55篇 |
1991年 | 30篇 |
1990年 | 37篇 |
1989年 | 42篇 |
1988年 | 37篇 |
1987年 | 19篇 |
1986年 | 32篇 |
1985年 | 18篇 |
1984年 | 18篇 |
1983年 | 20篇 |
1982年 | 26篇 |
1981年 | 25篇 |
1980年 | 19篇 |
1979年 | 12篇 |
1977年 | 13篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 11篇 |
1969年 | 10篇 |
1968年 | 10篇 |
排序方式: 共有4038条查询结果,搜索用时 15 毫秒
91.
92.
Gordon H. Theilen Donald L. Dungworth Thomas G. Kawakami 《The Western journal of medicine》1968,108(1):14-19
General comparative aspects of leukemia were reviewed. Leukemia in adult cattle occurs frequently within certain multiple case herds. Cattle in these herds often have persistent lymphocytosis and increased numbers of atypical lymphocytes in blood. Attempts are being made to demonstrate the frequency in which this is a “pre-leukemic” or “perileukemic” condition.With the recognition of viral causative agent(s) in chickens, laboratory rodents and cats, there is increased interest in the leukemia of dogs, cattle and other animals, for the disease in these animals may serve as valuable models in the study and isolation of human leukemogenic agents.Epidemiologic and clinicopathologic aspects of animal leukemias share comparative similarities with themselves and with lymphoreticular neoplasms of man. Causative factor(s) probably act on the host, regardless of species, in a similar fashion. It is not likely, but neither improbable, that leukemia in domesticated animals and leukemia in man share common causal relationships. 相似文献
93.
The egg white was treated under various whipping conditions, and its foaminess measured. At the same time, the amounts of the coagulated proteins formed from each egg white and their constituent hexose were measured. From these results, discussions were made about the relation between the foaminess of the egg white and the amount of the coagulated proteins under various whipping conditions. 相似文献
94.
Limnology - Highly concentrated dissolved silicate was detected in pore water from anoxic-reducing sediment in Lake Nakaumi, a brackish lake. Silicate concentration also simultaneously increased... 相似文献
95.
Toshihiro Kimura Satoshi Fukushima Etsuko Okada Haruka Kuriyama Hisashi Kanemaru Mina Kadohisa‐Tsuruta Yosuke Kubo Satoshi Nakahara Aki Tokuzumi Ikko Kajihara Katsunari Makino Azusa Miyashita Jun Aoi Takamitsu Makino Hirotake Tsukamoto Yasuharu Nishimura Takashi Inozume Rong Zhang Yasushi Uemura Satoru Senju Hironobu Ihn 《Pigment cell & melanoma research》2020,33(5):744-755
Immune checkpoint inhibitors improved the survival rate of patients with unresectable melanoma. However, some patients do not respond, and variable immune‐related adverse events have been reported. Therefore, more effective and antigen‐specific immune therapies are urgently needed. We previously reported the efficacy of an immune cell therapy with immortalized myeloid cells derived from induced pluripotent stem cells (iPS‐ML). In this study, we generated OX40L‐overexpressing iPS‐ML (iPS‐ML‐Zsgreen‐OX40L) and investigated their characteristics and in vivo efficacy against mouse melanoma. We found that iPS‐ML‐Zsgreen‐OX40L suppressed the progression of B16‐BL6 melanoma, and prolonged survival of mice with ovalbumin (OVA)‐expressing B16 melanoma (MO4). The number of antigen‐specific CD8+ T cells was higher in spleen cells treated with OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L than in those without OX40L. The OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L significantly increased the number of tumor‐infiltrating T lymphocytes (TILs) in MO4 tumor. Flow cytometry showed decreased regulatory T cells but increased effector and effector memory T cells among the TILs. Although we plan to use allogeneic iPS‐ML in the clinical applications, iPS‐ML showed the tumorgenicity in the syngeneic mice model. Incorporating the suicide gene is necessary to ensure the safety in the future study. Collectively, these results indicate that iPS‐ML‐Zsgreen‐OX40L therapy might be a new method for antigen‐specific cancer immunotherapy. 相似文献
96.
97.
Huaxin Yu Tasuku Hamaguchi Yoshiki Nakajima Koji Kato Keisuke Kawakami Fusamichi Akita Koji Yonekura Jian-Ren Shen 《BBA》2021,1862(10):148471
Photosystem II (PSII) functions mainly as a dimer to catalyze the light energy conversion and water oxidation reactions. However, monomeric PSII also exists and functions in vivo in some cases. The crystal structure of monomeric PSII has been solved at 3.6 Å resolution, but it is still not clear which factors contribute to the formation of the dimer. Here, we solved the structure of PSII monomer at a resolution of 2.78 Å using cryo-electron microscopy (cryo-EM). From our cryo-EM density map, we observed apparent differences in pigments and lipids in the monomer-monomer interface between the PSII monomer and dimer. One β-carotene and two sulfoquinovosyl diacylglycerol (SQDG) molecules are found in the monomer-monomer interface of the dimer structure but not in the present monomer structure, although some SQDG and other lipid molecules are found in the analogous region of the low-resolution crystal structure of the monomer, or cryo-EM structure of an apo-PSII monomer lacking the extrinsic proteins from Synechocystis sp. PCC 6803. In the current monomer structure, a large part of the PsbO subunit was also found to be disordered. These results indicate the importance of the β-carotene, SQDG and PsbO in formation of the PSII dimer. 相似文献
98.
99.
Kie Itoh Yasushi Tamura Miho Iijima Hiromi Sesaki 《Molecular biology of the cell》2013,24(12):1842-1851
Mitochondrial DNA (mtDNA) is packaged into DNA–protein complexes called nucleoids, which are distributed as many small foci in mitochondria. Nucleoids are crucial for the biogenesis and function of mtDNA. Here, using a yeast genetic screen for components that control nucleoid distribution and size, we identify Fcj1 and Mos1, two evolutionarily conserved mitochondrial proteins that maintain the connection between the cristae and boundary membranes. These two proteins are also important for establishing tubular morphology of mitochondria, as mitochondria lacking Fcj1 and Mos1 form lamellar sheets. We find that nucleoids aggregate, increase in size, and decrease in number in fcj1∆ and mos1∆ cells. In addition, Fcj1 form punctate structures and localized adjacent to nucleoids. Moreover, connecting mitochondria by deleting the DNM1 gene required for organelle division enhances aggregation of mtDNA nucleoids in fcj1∆ and mos1∆ cells, whereas single deletion of DNM1 does not affect nucleoids. Conversely, deleting F1Fo-ATP synthase dimerization factors generates concentric ring-like cristae, restores tubular mitochondrial morphology, and suppresses nucleoid aggregation in these mutants. Our findings suggest an unexpected role of Fcj1-Mos1 and organelle division in maintaining the distribution and size of mtDNA nucleoids. 相似文献
100.
Yasushi Mitani Jaehyuk Choi 《Computer methods in biomechanics and biomedical engineering》2013,16(13):722-729
AbstractThis paper presents a boosting effect against gravity by analyzing the displacement and stress distribution of craniofacial structures due to the protraction of the extraoral device, the Right Angle Maxillary Protraction Appliance(RAMPA) system, including semi-rapid maxillary expansion (sRME) using the finite element method. In addition, a patient case was illustrated and compared with the results calculated from a simulation. The results from the finite element method were obtained for 0.5?mm activation using the screw of the intraoral device, gHu-1. This study reveals that RAMPA rotates the patient’s maxilla and mandible in the forward direction and forces them to move forward and upward. 相似文献