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881.
David J. Lakatua Erhard Haus Franz Halberg Erna Halberg Hans W. Wendt Linda L. Sackett-Lundeen Harriet G. Berg Terukazu Kawasaki Michio Ueno Keiko Uezono Midori Matsuoka Teruo Omae 《Chronobiology international》1986,3(3):189-195
Clinically healthy diurnally active young adult women were studied during the same season (March) at the Universities of Kyushu (Fukuoka City, Japan) and of Minnesota (Minneapolis, USA), under comparable conditions, except that the habitual diets were not changed. The subjects (20 Japanese and 16 Americans of mixed Caucasian background) were studied over a single 24-hr span. Urine was collected at 4-hr intervals. A circadian rhythm in total urinary norepinephrine excretion showed similar characteristics in Japanese and Americans. In epinephrine excretion, the Japanese women showed a statistically significantly higher amplitude with higher peak values, but no statistically significant difference in the rhythm-adjusted mean. This intergroup difference is strictly time dependent; it does not come to the fore in urine samples covering the nocturnal rest span of the subjects. 相似文献
882.
883.
Kikuyama Munehiro; Oda Kenji; Shimmen Teruo; Hayama Tomio; Tazawa Masashi 《Plant & cell physiology》1984,25(6):965-974
Action potentials of intact and tonoplast-free Characeae cellswere studied in relation to the effluxes of K$ and Cl-. K$ effluxwas monitored by atomic absorption spectroscopy or direct measurementof 42K efflux. Cl- efflux was monitored by the Ag-AgCl electrodemethod. A large K$ efflux was always observed during excitations irrespectiveof whether the cell was intact or tonoplast-free. In tonoplast-freecells, the permeability of the plasma membrane for K$ at theplateau of the prolonged action potential was almost the sameas that in the resting state. In many cases, Cl- efflux wasalso observed during excitations of intact cells although somecells showed action potentials without a detectable increasein Cl- efflux. Almost all tonoplast-free cells generated actionpotentials with no associated increase in Cl- efflux. Theseresults indicate that some ion other than Cl- carries inwardcurrent which balances the outward current carried by K$. Calciumion is discussed as the most probable candidate. (Received November 18, 1983; Accepted June 12, 1984) 相似文献
884.
Summary Evolutionary constraints operating on animal mitochondrial tRNA were estimated to be reduced to about 1/30 of those that apply to cytoplasmic tRNA. In the nuclear-cytoplasmic system, an effect of a mutation tRNA is likely to be amplified through positive feedback loops consisting of DNA polymerases, RNA polymerases, ribosomal proteins, aminoacyl-tRNA synthetases, tRNA processing enzymes, and others. This amplification phenomenon is called an error cascade and the loops that cause it are called error loops. The freedom of evolutionary change of cytoplasmic tRNA is expected to be severely restricted to avoid the error cascade. In fact, cytoplasmic tRNA is highly conserved during evolution. On the other hand, in the animal mitochondrial system, all of the proteins involved in error loops are coded for in the nuclear genome and imported from the cytoplasm, and accordingly the system is free from the error cascade. The difference in constraints operating on animal tRNA between cytoplasm and mitochondria is attributed to the presence or absence of error loops. It is shown that the constraints on mitochondrial tRNA in fungi are not as relaxed as those in animals. This observation is attributed to the presence of an error loop in fungal mitochondria, since at least one protein of the mitochondrial ribosome is coded for in the mitochondrial genome of fungi. The evolutionary rates of proteins involved in the processing of genetic information are discussed in relation to the error cascade.A preliminary version of this paper was presented at the International tRNA Workshop (Hakone, Japan, March 1983) and at the Second International Colloquium on Endocytobiology (Tübingen, FRG, April 1983) 相似文献
885.
Antigen-specific augmentation factor involved in murine delayed-type footpad reaction. I. Nature of augmentation factor 总被引:1,自引:0,他引:1
A humoral factor capable of augmenting antigen-specific DTH has been found in the culture supernatant of immune spleen cells and erythrocyte antigen. In this study, a similar factor was identified in the sera of mice sensitized and elicited with heterologous erythrocytes, and the nature of this factor was investigated. Elicitation with antigen was essentially required for the production of the augmentation factor in sensitized mice. The factor showed antigen specificity and antigen-binding capacity. The activity was not assigned to immunoglobulins, as demonstrated by an absorption test with rabbit anti-mouse immunoglobulin-conjugated Sepharose. The activity was stable to heating at 56 degrees C for 30 min, to changes of pH from 3 to 10, and to treatment with trypsin or neuraminidase. The molecular weight of this factor was about 200,000 to 450,000. 相似文献
886.
887.
888.
Tadashi Noto Takeshi Hasegawa Junji Nakao Hiroshi Kamimura Hiroyuki Harada Teruo Nakajima 《Journal of neurochemistry》1988,51(2):548-551
gamma-Amino-beta-[3H]hydroxybutyric acid ([3H]-GABOB) was formed in rat brain from 2-[3H]-hydroxyputrescine that had been chemically synthesized from 2-oxoputrescine and [3H]sodium borohydride. After the injection of 2-[3H]hydroxyputrescine into the lateral ventricle of a rat brain, the rat was killed and then the brain was removed. [3H]GABOB in the brain was identified by a combination of ion-exchange chromatography, high-voltage paper electrophoresis, and recrystallization of the radioactive compound with authentic GABOB. 相似文献
889.
Sayuri Gyobu Haruhiko Miyata Masahito Ikawa Daiju Yamazaki Hiroshi Takeshima Jun Suzuki Shigekazu Nagata 《Molecular and cellular biology》2016,36(4):645-659
Transmembrane protein 16E (TMEM16E) belongs to the TMEM16 family of proteins that have 10 transmembrane regions and appears to localize intracellularly. Although TMEM16E mutations cause bone fragility and muscular dystrophy in humans, its biochemical function is unknown. In the TMEM16 family, TMEM16A and -16B serve as Ca2+-dependent Cl− channels, while TMEM16C, -16D, -16F, -16G, and -16J support Ca2+-dependent phospholipid scrambling. Here, we show that TMEM16E carries a segment composed of 35 amino acids homologous to the scrambling domain in TMEM16F. When the corresponding segment of TMEM16A was replaced by this 35-amino-acid segment of TMEM16E, the chimeric molecule localized to the plasma membrane and supported Ca2+-dependent scrambling. We next established TMEM16E-deficient mice, which appeared to have normal skeletal muscle. However, fertility was decreased in the males. We found that TMEM16E was expressed in germ cells in early spermatogenesis and thereafter and localized to sperm tail. TMEM16E−/− sperm showed no apparent defect in morphology, beating, mitochondrial function, capacitation, or binding to zona pellucida. However, they showed reduced motility and inefficient fertilization of cumulus-free but zona-intact eggs in vitro. Our results suggest that TMEM16E may function as a phospholipid scramblase at inner membranes and that its defect affects sperm motility. 相似文献
890.
Fujita K Yamaguchi Y Mori T Muramatsu N Miyamoto T Yano M Miyata H Ootsuyama A Sawada M Matsuda H Kaji R Sakaguchi S 《Cellular and molecular neurobiology》2011,31(7):999-1008
We first verified that a single chain Fv fragment against prion protein (anti-PrP scFv) was secreted by HEK293T cells and prevented prion replication in infected cells. We then stably expressed anti-PrP scFv in brain-engraftable murine microglial cells and intracerebrally injected these cells into mice before or after infection with prions. Interestingly, the injection before or at an early time point after infection attenuated the infection marginally but significantly prolonged survival times of the mice. These suggest that the ex vivo gene transfer of anti-PrP scFvs using brain-engraftable cells could be a possible immunotherapeutic approach against prion diseases. 相似文献