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101.
Koizumi K Tanimoto T Okada Y Takeyama S Hamayasu K Hashimoto H Kitahata S 《Carbohydrate research》1998,314(1-2):115-125
Di- and tri-mannosyl-cyclomaltoheptaoses (beta-cyclodextrins, beta CDs), which were synthesized together with monomannosyl-beta CD in a large-scale production by reverse action of alpha-mannosidase from jack bean, were isolated and purified by HPLC. The structures of seven isomers of di-mannosyl-beta CD and six isomers of tri-mannosyl-beta CD were elucidated by FABMS and NMR spectroscopy, and by enzymatic methods. 相似文献
102.
A Marked Increase in Free Copper Levels in the Plasma and Liver of LEC Rats: An Animal Model for Wilson Disease and Liver Cancer 总被引:3,自引:0,他引:3
Masahiko Koizumi Junichi Fujii Keiichiro Suzuki Takehiro Inoue Toshihiko Inoue John M. C. Gutteridge Naoyuki Taniguchi 《Free radical research》1998,28(5):441-450
Most of copper present in rat plasma and liver binds to caeruloplasmin and metallothionein, respectively, and is not redox active. However, free forms of copper including loosely bound forms to other molecules are redox active. We assessed the free copper in Long-Evans rats with a cinnamon-like coat color (LEC rats), an animal model of Wilson disease and liver cancer. Compared to those of control rats, the liver and plasma of LEC rats showed a marked elevation of free copper, especially at the stage of acute hepatitis, in parallel with an increase of total copper levels in the livers and a decrease of plasma caeruloplasmin (ferroxidase I) activity. At the onset of jaundice, the total copper levels, however, decreased in liver, but increased in plasma, while free copper levels in both liver and plasma remained higher. Free iron levels in both liver and plasma were also determined and did not change significantly, except for the case of plasma in jaundiced rats. The data are consistent with a proposal in which increased levels of redox active free copper in the liver of LEC rats catalyze Fenton-type reactions, producing a large flux of hydroxyl radicals that would play an important role in the observed liver dysfunction, leading to acute hepatitis, and, finally, hepatocarcinoma. This is the first demonstration that the free copper may participate in the pathophysiology of the LEC rats and Wilson disease. 相似文献
103.
Shoki Inui Yoshihiro Ueda Shunsuke Ono Shingo Ohira Masaru Isono Yuya Nitta Hikari Ueda Masayoshi Miyazaki Masahiko Koizumi Teruki Teshima 《Reports of Practical Oncology and Radiotherapy》2021,26(2):281
BackgroundThe aim of the study was to evaluate analysis criteria for the identification of the presence of rectal gas during volumetric modulated arc therapy (VMAT) for prostate cancer patients by using electronic portal imaging device (EPID)-based in vivo dosimetry (IVD).Materials and methodsAll measurements were performed by determining the cumulative EPID images in an integrated acquisition mode and analyzed using PerFRACTION commercial software. Systematic setup errors were simulated by moving the anthropomorphic phantom in each translational and rotational direction. The inhomogeneity regions were also simulated by the I’mRT phantom attached to the Quasar phantom. The presence of small and large air cavities (12 and 48 cm3) was controlled by moving the Quasar phantom in several timings during VMAT. Sixteen prostate cancer patients received EPID-based IVD during VMAT.ResultsIn the phantom study, no systematic setup error was detected in the range that can happen in clinical (< 5-mm and < 3 degree). The pass rate of 2% dose difference (DD2%) in small and large air cavities was 98.74% and 79.05%, respectively, in the appearance of the air cavity after irradiation three quarter times. In the clinical study, some fractions caused a sharp decline in the DD2% pass rate. The proportion for DD2% < 90% was 13.4% of all fractions. Rectal gas was confirmed in 11.0% of fractions by acquiring kilo-voltage X-ray images after the treatment.ConclusionsOur results suggest that analysis criteria of 2% dose difference in EPID-based IVD was a suitable method for identification of rectal gas during VMAT for prostate cancer patients. 相似文献
104.
Ryutaro Kakinuma Noriyuki Moriyama Yukio Muramatsu Shiho Gomi Masahiro Suzuki Hirobumi Nagasawa Masahiko Kusumoto Tomohiko Aso Yoshihisa Muramatsu Takaaki Tsuchida Koji Tsuta Akiko Miyagi Maeshima Naobumi Tochigi Shun-ichi Watanabe Naoki Sugihara Shinsuke Tsukagoshi Yasuo Saito Masahiro Kazama Kazuto Ashizawa Kazuo Awai Osamu Honda Hiroyuki Ishikawa Naoya Koizumi Daisuke Komoto Hiroshi Moriya Seitaro Oda Yasuji Oshiro Masahiro Yanagawa Noriyuki Tomiyama Hisao Asamura 《PloS one》2015,10(12)
105.
Emiko Anegawa Nozomu Kotorii Yuji Ishimaru Masashi Okuro Noriaki Sakai Seiji Nishino 《PloS one》2015,10(12)
The purpose of this study is to clarify the effects of chronic powder diet feeding on sleep patterns and other physiological/anatomical changes in mice. C57BL/6 male mice were divided into two groups from weaning: a group fed with solid food (SD) and a group fed with powder food (PD), and sleep and physiological and anatomical changes were compared between the groups. PD exhibited less cranial bone structure development and a significant weight gain. Furthermore, these PD mice showed reduced number of neurogenesis in the hippocampus. Sleep analysis showed that PD induced attenuated diurnal sleep/wake rhythm, characterized by increased sleep during active period and decreased sleep during rest period. With food deprivation (FD), PD showed less enhancement of wake/locomotor activity compared to SD, indicating reduced food-seeking behavior during FD. These results suggest that powder feeding in mice results in a cluster of detrimental symptoms caused by abnormal energy metabolism and anatomical/neurological changes. 相似文献
106.
A novel factor FLOURY ENDOSPERM2 is involved in regulation of rice grain size and starch quality 总被引:6,自引:0,他引:6
She KC Kusano H Koizumi K Yamakawa H Hakata M Imamura T Fukuda M Naito N Tsurumaki Y Yaeshima M Tsuge T Matsumoto K Kudoh M Itoh E Kikuchi S Kishimoto N Yazaki J Ando T Yano M Aoyama T Sasaki T Satoh H Shimada H 《The Plant cell》2010,22(10):3280-3294
Rice (Oryza sativa) endosperm accumulates a massive amount of storage starch and storage proteins during seed development. However, little is known about the regulatory system involved in the production of storage substances. The rice flo2 mutation resulted in reduced grain size and starch quality. Map-based cloning identified FLOURY ENDOSPERM2 (FLO2), a member of a novel gene family conserved in plants, as the gene responsible for the rice flo2 mutation. FLO2 harbors a tetratricopeptide repeat motif, considered to mediate a protein-protein interactions. FLO2 was abundantly expressed in developing seeds coincident with production of storage starch and protein, as well as in leaves, while abundant expression of its homologs was observed only in leaves. The flo2 mutation decreased expression of genes involved in production of storage starch and storage proteins in the endosperm. Differences between cultivars in their responsiveness of FLO2 expression during high-temperature stress indicated that FLO2 may be involved in heat tolerance during seed development. Overexpression of FLO2 enlarged the size of grains significantly. These results suggest that FLO2 plays a pivotal regulatory role in rice grain size and starch quality by affecting storage substance accumulation in the endosperm. 相似文献
107.
Masaki Uchida Ayaka Kishimoto Hiroyuki Muraoka Takayuki Nakatsubo Hiroshi Kanda Hiroshi Koizumi 《Journal of plant research》2010,123(1):79-85
We examined factors controlling temporal changes in net ecosystem production (NEP) in a high Arctic polar semi-desert ecosystem
in the snow-free season. We examined the relationships between NEP and biotic and abiotic factors in a dominant plant community
(Salix polaris–moss) in the Norwegian high Arctic. Just after snowmelt in early July, the ecosystem released CO2 into the atmosphere. A few days after snowmelt, however, the ecosystem became a CO2 sink as the leaves of S. polaris developed. Diurnal changes in NEP mirrored changes in light incidence (photosynthetic photon flux density, PPFD) in summer.
NEP was significantly correlated with PPFD when S. polaris had fully developed leaves, i.e., high photosynthetic activity. In autumn, NEP values decreased as S. polaris underwent senescence. During this time, CO2 was sometimes released into the atmosphere. In wet conditions, moss made a larger contribution to NEP. In fact, the water
content of the moss regulated NEP during autumn. Our results indicate that the main factors controlling NEP in summer are
coverage and growth of S. polaris, PPFD, and precipitation. In autumn, the main factor controlling NEP is moss water content. 相似文献
108.
Hydrographic variability in the Mixed Water Region of the Northwest Pacific Ocean at latitudes 35°–40°N, between the Kuroshio Extension and Oyashio Front, causes complex upwelling, leading to large primary productivity and thus great fishery resources. We reconstructed the periodicity of the variability in North Pacific Intermediate Water upwelling and surface ocean hydrography based on the high-resolution analysis of diatom assemblages in seven cores, representing the last 150,000 years. We derived annual sea surface temperatures (SSTs) through a diatom-based proxy (Td′). The Td′-derived annual SSTs (°C) are controlled by orbital forcing, and show a reversed saw-tooth in southern cores, in contrast to a normal saw-tooth pattern in the northern cores. Oceanic diatom abundances along the northern margin of the Mixed Water Region are twice times as high as beneath the axis of the Kuroshio Extension, and fluctuated in a revised saw-tooth pattern with higher overall abundances interglacials. After the last deglaciation, annual SSTs declined markedly during Heinrich and Bond events in the northern North Atlantic, when ice-rafted detritus transported by icebergs was abundant. Wavelet analyses of the record of oceanic diatom abundances show significant variability at 2.0-kyr, 2 to 5.6-kyr and 3.2 to 9.6-kyr periods. Wavelet analyses of the annual SST records show significant periodicity at 1.4 to 2.6-kyr, 3.3 to 4.0-kyr, 7.2 to 12.8-kyr cycles. 相似文献
109.
110.
Koizumi J Kojima T Kamekura R Kurose M Harimaya A Murata M Osanai M Chiba H Himi T Sawada N 《The Journal of membrane biology》2007,218(1-3):1-7
The epithelium of upper respiratory tissues such as nasal mucosa forms a continuous barrier to a wide variety of exogenous
antigens. The epithelial barrier function is regulated in large part by the intercellular junctions, referred to as gap and
tight junctions. However, changes of gap and tight junctions during differentiation of human nasal epithelial (HNE) cells
are still unclear. In the present study, to investigate changes of gap and tight junctions during differentiation of HNE cells
in vitro, we used primary human HNE cells cocultured with primary human nasal fibroblast (HNF) cells in a noncontact system. In HNE
cells cocultured with HNF cells for 2 weeks, numerous elongated cilia-like structures were observed compared to those without
HNF cells. In the coculture, downregulation of Cx26 and upregulation of Cx30.3 and Cx31 were observed together with extensive
gap junctional intercellular communication. Furthermore, expression of the tight junction proteins claudin-1, claudin-4, occludin
and ZO-2 was increased. These results suggest that switching in expression of connexins and induction of tight junction proteins
may be closely associated with differentiation of HNE cells in
vitro and that differentiation of HNE cells requires unknown soluble factors secreted from HNF cells. 相似文献