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991.
Incipient forebrain boundaries traced by differential gene expression and fate mapping in the chick neural plate 总被引:1,自引:0,他引:1
We correlated available fate maps for the avian neural plate at stages HH4 and HH8 with the progress of local molecular specification, aiming to determine when the molecular specification maps of the primary longitudinal and transversal domains of the anterior forebrain agree with the fate mapped data. To this end, we examined selected gene expression patterns as they normally evolved in whole mounts and sections between HH4 and HH8 (or HH10/11 in some cases), performed novel fate-mapping experiments within the anterior forebrain at HH4 and examined the results at HH8, and correlated grafts with expression of selected gene markers. The data provided new details to the HH4 fate map, and disclosed some genes (e.g., Six3 and Ganf) whose expression domains initially are very extensive and subsequently retract rostralwards. Apart from anteroposterior dynamics, some genes soon became downregulated at the prospective forebrain floor plate, or allowed to identify an early roof plate domain (dorsoventral pattern). Peculiarities of the telencephalon (initial specification and differentiation of pallium versus subpallium) are contemplated. The basic anterior forebrain subdivisions seem to acquire correlated specification and fate mapping patterns around stage HH8. 相似文献
992.
Ing-Marie Viklund Pontus Aspenström Vannary Meas-Yedid Jolanta Kopec Daniel Ågren Gunter Schneider Mauro D'Amato Jean-Christophe Olivo-Marin Guy Tran Van Nhieu Sven Pettersson 《Experimental cell research》2009,315(6):1040-220
We have previously identified a new gene with sequence homology to the WASP-family of actin regulators denoted WAFL (WASP and FKBP-like). Here we report a possible biological function for WAFL, by demonstrating an association to early endosomes via its central coiled-coil domain. Further we show by functional and structural studies that WAFL is associated with both microtubules and the actin filament system, the two means of transport of early endosomes. In addition, WAFL interacts with WASP-interacting protein (WIP) and actin, thus linking WAFL to actin dynamics. The use of RNAi depletion of WAFL shows that WAFL-deficient cells display delayed transport of endosomal cargo. Our findings are compatible with a model whereby WAFL is involved in the transport of early endosomes at the level of transition between microfilament-based and microtubule-based movement. 相似文献
993.
Menkes syndrome is an X-linked, fatal neurodegenerative disorder of copper metabolism, caused by mutations in the ATP7A gene, encoding a copper-transporting P1B-type ATPase. To date, a total of approximately 160 different mutations have been reported worldwide. The clinical phenotypes observed in these patients include progressive neuro-degeneration, connective-tissue abnormalities and peculiar hair. There is phenotypic variability. While the majority of the patients do not survive early childhood, milder cases leading to longer survival have been reported. In this review we focus on mutations, identified in patients with milder forms of Menkes disease, and discuss the possibility of establishing a genotype–phenotype correlation. The presence of small amounts of normal protein, or the presence of partly functional protein variants containing a less essential amino acid substitution or a truncation of the N- or C-terminus, might all result in a milder, atypical phenotype. A clear phenotype–genotype correlation is however difficult to establish, clearly illustrated by the presence of inter- and even intra-familial variability. 相似文献
994.
Background
Visceral fat (VF) accretion is a hallmark of aging in humans. Epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes, cardiovascular disease, metabolic syndrome and death.Methods
Studies utilizing novel rodent models of visceral obesity and surgical strategies in humans have been undertaken to determine if subcutaneous (SC) abdominal or VF are causally linked to age-related diseases.Results
Specific depletion or expansion of the VF depot using genetic or surgical tools in rodents has been shown to have direct effects on disease risk. In contrast, surgically removing large quantities of SC fat does not consistently improve metabolic parameters in humans or rodents, while benefits were observed with SC fat expansion in mice, suggesting that SC fat accrual is not an important contributor to metabolic decline. There is also compelling evidence in humans that abdominal obesity is a stronger risk factor for mortality risk than general obesity. Likewise, we have shown that surgical removal of VF improves mean and maximum lifespan in rats, providing the first causal evidence that VF depletion may be an important underlying cause of improved lifespan with caloric restriction.General significance
This review provides both corollary and causal evidence for the importance of accounting for body fat distribution, and specifically VF, when assessing disease and mortality risk. Given the hazards of VF accumulation on health, treatment strategies aimed at selectively depleting VF should be considered as a viable tool to effectively reduce disease risk in humans. 相似文献995.
Nakatani Y Hotta S Utsunomiya I Tanaka K Hoshi K Ariga T Yu RK Miyatake T Taguchi K 《Neurochemical research》2009,34(1):149-157
To investigate the pathophysiological mechanisms of immune-mediated peripheral neuropathies, we studied the effects of sera
from patients with Guillain-Barré syndrome (GBS) on the Cav2.1 voltage-dependent calcium channel (VDCC) current in Purkinje
cells. Using the whole-cell recording technique, Cav2.1 VDCC current was measured in cerebellar Purkinje cells in the presence
of serum from GBS patients with acute motor axonal neuropathy (AMAN) or acute inflammatory demyelinating polyneuropathy (AIDP).
The AMAN patient sera significantly inhibited the Cav2.1 VDCC current compared with healthy volunteer sera, and this inhibition
was fully reversible by washing out the AMAN serum. Similarly, IgG purified from AMAN sera also inhibited the Cav2.1 VDCC
current. However, the activation and inactivation kinetics of the Cav2.1 VDCC currents were not affected by serum from an
AMAN patient. Moreover, the VDCC current of Purkinje cells was also inhibited by IgG anti-GM1 monoclonal antibody (anti-GM1
mAb). In an immunocytochemical study using double fluorescence staining, Purkinje cells were stained by monoclonal IgG anti-GM1
mAb. In contrast, AIDP patient and healthy volunteer sera did not affect the Cav2.1 VDCC current. These results suggest that
in some case of GBS, particularly of AMAN patients with IgG anti-GM1 mAb, muscle weakness may be induced by dysfunction of
Cav2.1 VDCC functioning at the motor nerve terminals.
Special issue article in honor of Dr. George DeVries. 相似文献
996.
Jaya G Yodh Benjamin C Stevens Radhakrishnan Kanagaraj Pavel Janscak Taekjip Ha 《The EMBO journal》2009,28(4):405-416
Bloom syndrome (BS) is a rare genetic disorder characterized by genomic instability and a high predisposition to cancer. The gene defective in BS, BLM, encodes a member of the RecQ family of 3′–5′ DNA helicases, and is proposed to function in recombinational repair during DNA replication. Here, we have utilized single‐molecule fluorescence resonance energy transfer microscopy to examine the behaviour of BLM on forked DNA substrates. Strikingly, BLM unwound individual DNA molecules in a repetitive manner, unwinding a short length of duplex DNA followed by rapid reannealing and reinitiation of unwinding in several successions. Our results show that a monomeric BLM can ‘measure’ how many base pairs it has unwound, and once it has unwound a critical length, it reverses the unwinding reaction through strand switching and translocating on the opposing strand. Repetitive unwinding persisted even in the presence of hRPA, and interaction between wild‐type BLM and hRPA was necessary for unwinding reinitiation on hRPA‐coated DNA. The reported activities may facilitate BLM processing of stalled replication forks and illegitimately formed recombination intermediates. 相似文献
997.
Hair Tissue Mineral Analysis and Metabolic Syndrome 总被引:1,自引:0,他引:1
Deficiency of minerals causes functional abnormality of enzymes, frequently resulting in metabolic disturbance. We investigated
possible relationship between minerals and metabolic syndrome by analysis of hair tissue minerals. We selected 848 subjects
older than 20 years of age at Ajou University Hospital from May 2004 to February 2007. We excluded the subjects who had cancers,
steroid and thyroid medication, and incomplete record from the study. Finally, 343 subjects were eligible. We performed cross-sectional
analysis for the relationship between minerals and metabolic syndrome. The contents of calcium, magnesium, and copper in the
metabolic syndrome group were significantly lower than those of the normal group, whereas the amounts of sodium, potassium,
and mercury in the metabolic syndrome group were significantly higher than those of the normal group. By dividing the subjects
into quartile with the level of calcium, magnesium, and mercury concentrations, we carried out logistic regression analysis
to study the subjects and found that the subjects in the third quartile of calcium and magnesium concentrations had significantly
lower odds ratio (OR) of the metabolic syndrome compared with that of the lowest quartile group [OR = 0.30, confidence interval
(CI) = 0.10–0.89; OR = 0.189, CI = 0.063–0.566] and that the subjects in the highest mercury quartile had significantly higher
OR of the metabolic syndrome compared with that of the lowest mercury quartile group (OR = 7.35, CI = 1.73–31.1). As part
of the metabolic syndrome, the optimal calcium and magnesium concentrations in hair tissue may reflect decreased risk of metabolic
syndrome, whereas high mercury concentration in hair tissue may indicate increased risk of metabolic syndrome. 相似文献
998.
Ana Whyte Luis V. Monteagudo Angel Díaz-Otero M. Eugenia Lebrero M. Teresa Tejedor M. Victoria Falceto Jaime Whyte Margarita Gallego 《Animal reproduction science》2009,115(1-4):328-333
Persistence of the Müllerian duct syndrome (PMDS) is a rare form of pseudohermaphroditism characterized by the presence of uterus and oviducts in otherwise normally differentiated SRY-positive 78 XY canine males. Undescended testicles are also common. We report a case of a male PMDS dog with a uterus and bilateral cryptorchidism. The dog had an incomplete regression of the mesonephric tubules. As a consequence of this an abnormally enlarged head of the epididymis was observed. In addition, an extreme reduction in size of both the body and the tail was found. Microscopic examination of both testicles revealed bilateral hyperplasia of Leydig cells. The progesterone blood level was measured by ELISA and was found to be abnormally high (3.18 ng/ml) compared to that of normal male dogs (lower than 1 ng/ml). Three months after surgical removal of the internal genitalia, the serum progesterone, testosterone and oestradiol levels were normal for a castrated male dog. 相似文献
999.
Koji Ishii Hideki Hasegawa Noriyo Nagata Yasushi Ami Shuetsu Fukushi Fumihiro Taguchi Yasuko Tsunetsugu-Yokota 《Microbiology and immunology》2009,53(2):75-82
We evaluated the efficacy of three SARS vaccine candidates in a murine SARS model utilizing low-virulence Pp and SARS-CoV coinfection. Vaccinated mice were protected from severe respiratory disease in parallel with a low virus titer in the lungs and a high neutralizing antibody titer in the plasma. Importantly, the administration of spike protein-specific neutralizing monoclonal antibody protected mice from the disease, indicating that the neutralization is sufficient for protection. Moreover, a high level of IL-6 and MCP-1 production, but not other 18 cytokines tested, on days 2 and 3 after SARS-CoV infection was closely linked to the virus replication and disease severity, suggesting the importance of these cytokines in the lung pathogenicity of SARS-CoV infection. 相似文献
1000.
O. Hoegh-Guldberg 《Coral reefs (Online)》2009,28(3):569-575
Maynard et al. (Coral Reefs 27:745–749, 2008a) claim that much of the concern about the impacts of climate change on coral reefs has been “based on essentially untested
assumptions regarding reefs and their capacity to cope with future climate change”. If correct, this claim has important implications
for whether or not climate change represents the largest long-term threat to the sustainability of coral reefs, especially
given their ad hominem argument that many coral reef scientists are guilty of “popularising worst-case scenarios” at the expense
of truth. This article looks critically at the claims made by Maynard et al. (Coral Reefs 27:745–749, 2008a) and comes to a very different conclusion, with the thrust and veracity of their argument being called into question. Contrary
to the fears of Grigg (Coral Reefs 11:183–186, 1992), who originally made reference to the Cassandra syndrome due to his concern about the sensationalisation of science, the
proposition that coral reefs face enormous challenges from climate change and ocean acidification has and is being established
through “careful experimentation, long-term monitoring and objective interpretation”. While this is reassuring, coral reef
ecosystems continue to face major challenges from ocean warming and acidification. Given this, it is an imperative that scientists
continue to maintain the rigour of their research and to communicate their conclusions as widely and clearly as possible.
Given the shortage of time and the magnitude of the problem, there is little time to spare. 相似文献