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21.
Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations 总被引:9,自引:1,他引:9
Meyer J; Sudbeck P; Held M; Wagner T; Schmitz ML; Bricarelli FD; Eggermont E; Friedrich U; Haas OA; Kobelt A; Leroy JG; Van Maldergem L; Michel E; Mitulla B; Pfeiffer RA; Schinzel A; Schmidt H; Scherer G 《Human molecular genetics》1997,6(1):91-98
It has previously been shown that, in the heterozygous state, mutations in
the SOX9 gene cause campomelic dysplasia (CD) and the often associated
autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one
recurrent mutation were characterized in one SOX9 allele each, and in one
case, no mutation was found. Four missense mutations are all located within
the high mobility group (HMG) domain. They either reduce or abolish the
DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense
and three frameshift mutations identified, two leave the C-terminal
transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or
almost completely intact. When tested in cell transfection experiments, the
recurrent nonsense mutation Y440X, found in two patients who survived for
four and more than 9 years, respectively, exhibits some residual
transactivation ability. In contrast, a frameshift mutation extending the
protein by 70 residues at codon 507, found in a patient who died shortly
after birth, showed no transactivation. This is apparently due to
instability of the mutant SOX9 protein as demonstrated by Western blotting.
Amino acid substitutions and nonsense mutations are found in patients with
and without XY sex reversal, indicating that sex reversal in CD is subject
to variable penetrance. Finally, none of 18 female patients with XY gonadal
dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP
assays, providing evidence that SOX9 mutations do not usually result in XY
sex reversal without skeletal malformations.
相似文献
22.
23.
Objective To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). Methods Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation was performed in five patients. Results All patients and family members had normal morphologic characteristics and normal function of the left ventricular by 2-DE. Fourteen persons had abnormal findings indicating ARVC. Five had enlargement of the right ventricular with diffused hypocontractility, eight had thin and systolic bulging in the focal anterior wall with hypokinesia and one had bulging of the inferior wall. Twenty-five persons (seven patients and 18 family members) had abnormal findings in ECG. Positive ventricular late potential was recorded in 13 persons (six patients). Two to three monomorphic ventricular tachycardia (VT) with left bundle branch block (LBBB) configurations were induced in five patients. Ventricular fibrillation was induced in two patients during the electrophysiologic study (EPS). Five patients had very high pacing threshold and/or ineffective pacing in one or many regions of the right ventricle. Two members of one family died suddenly. One member was a dwarf with ARVC. Spontaneous VT with a left bundle branch block (LBBB) configuration was recorded in five patients, polymorphic VT with extremely short coupling interval in one, and premature ventricular complexes with LBBB configuration in 12 (six patients). Conclusion Our familial study strongly suggests that ARVC may be a hereditary disease and it is helpful in the diagnosis and detection of ARVC. The most common manifestations were abnormal structure and function of the right ventricle and abnormal ECG of repolarization and ventricular arrhythmia which originates from the right ventricle. 相似文献
24.
25.
It has been demonstrated in experiments on three dogs that test electrostimulation of the lateral hypothalamus reproduces the motoric reaction which is the signal stimulus during the development of classical alimentary CR (83%) and does not reproduce it during the development of classical defensive CR (93%). The test electrostimulation of the medial divisions of the hypothalamus, like the electrostimulation of the LH, reproduces the signal motoric reaction, but in a smaller percent of cases (62%), during the development of classical alimentary CR, and does not reproduce it during the development of classical defensive CR. The reproduction of the signal motoric reaction during the electrostimulation of the LH is associated with the activation of a backward conditioned connection from the motivational structures of the hypothalamus to the representation of the signal stimulus in the motor cortex.Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 41, No. 1, pp. 41–50, January–February, 1991. 相似文献
26.
The optic nerve and mesencephalic optic centre (tectum opticum, TO) of the tortoise, Testudo horsfieldi, Gray, in the norm and after the enucleation have been studies using Golgi's method, electron microscopy and the electrophysiological technique. The optic nerve comprises about 400,000 fibres represented by two classes of axons: myelinated (10%) and unmyelinated (90%). The diameters of the former vary within 0.3-3 mum, of the latter within 0.3-1.1 mum. The neurogramms of the optic nerve contain two components corresponding to the two rates of conduction through different groups of fibres (1.3 musec and 0.5 musec). The stratified synaptic organization of the TO has been investigated. The optic terminals are shown to join in complex synaptic formations at certain levels of the upper layers of the TO (Strata I, II and III). The process of degeneration in the optic system of Testudo is drastically stretched in time. It was demonstrated by the electrophysiological control that the TO potentials induced in response to the nerve stimulation were not registered any longer only 6-6.5 months after the enucleation. Certain groups of retinal fibres of the optic nerve and their terminals in the TO are shown to degenerate differently and asynchronously. Earlier unknown types of destructive changes of the terminals (vesicular, neurofilamentous, glycogen and others) are described. It is suggested that the different types of degeneration of the optic fibres and their terminals are the result of possible biochemical heterogeneity of the retinal ganglious cells. The comparison of the terms and types of degeneration of different groups of nervous fibres in the optic nerve and their terminals in the TO has revealed some correlations suggesting that the myelinated optic fibres produce nervous terminals degenerating by the "dark" type, whereas the unmyelinated optic axons may be subdivided into several groups, each producing nervous terminals subjected to a definite type of destruction ("clear", "vesicular", "neurofilamentous" etc.). The localization of certain groups of therminals at certain levels of the cortical plate of the TO confirms the electrophysiological data on the stratified organization of the retino-tectal projections in the TO of lower vertebrates. It has been shown by the comparison of the results obtained with those reported for Emys orbicularis, L. that the two species have marked differences in the morpho-functional characteristics of the retino-tectal system, neuronic composition of the TO, the character of destructive changes of the terminals after the enucleation and the component composition of polysynaptic complexes and glomerules. Probably these differences may come from the peculiarities of the perception and transformation of visual information in the species. 相似文献
27.
28.
Gonzales AJ; Christensen JG; Preston RJ; Goldsworthy TL; Tlsty TD; Fox TR 《Carcinogenesis》1998,19(7):1173-1183
29.
Identification of differentially expressed genes in aflatoxin B1- treated cultured primary rat hepatocytes and Fischer 344 rats 总被引:4,自引:1,他引:4
Harris AJ; Shaddock JG; Manjanatha MG; Lisenbey JA; Casciano DA 《Carcinogenesis》1998,19(8):1451-1458
Aflatoxin B1 (AFB1), a mutagen and hepatocarcinogen in rats and humans, is
a contaminant of the human food supply, particularly in parts of Africa and
Asia. AFB1-induced changes in gene expression may play a part in the
development of the toxic, immunosuppressive and carcinogenic properties of
this fungal metabolite. An understanding of the-role of AFB1 in modulating
gene regulation should provide insight regarding mechanisms of AFB1-induced
carcinogenesis. We used three PCR- based subtractive techniques to identify
AFB1-responsive genes in cultured primary rat hepatocyte RNA: differential
display PCR (DD-PCR), representational difference analysis (RDA) and
suppression subtractive hybridization (SSH). Each of the three techniques
identified AFB1- responsive genes, although no individual cDNA was isolated
by more than one technique. Nine cDNAs isolated using DD-PCR, RDA or SSH
were found to represent eight genes that are differentially expressed as a
result of AFB1 exposure. Genes whose mRNA levels were increased in cultured
primary rat hepatocytes after AFB1 treatment were corticosteroid binding
globulin (CBG), cytochrome P450 4F1 (CYP4F1), alpha-2 microglobulin,
C4b-binding protein (C4BP), serum amyloid A-2 and glutathione S-transferase
Yb2 (GST). Transferrin and a small CYP3A-like cDNA had reduced mRNA levels
after AFB1 exposure. Full-length CYP3A mRNA levels were increased. When
liver RNA from AFB1-treated male F344 rats was evaluated for transferrin,
CBG, GST, CYP3A and CYP4F1 expression, a decrease in transferrin mRNA and
an increase in CBG, GST, CYP3A and CYP4F1 mRNA levels was also seen.
Analysis of the potential function of these genes in maintaining cellular
homeostasis suggests that their differential expression could contribute to
the toxicity associated with AFB1 exposure.
相似文献
30.
Characterization of the insulin-like growth factor axis in a human hepatoma cell line (PLC) 总被引:4,自引:0,他引:4
Scharf JG; Schmidt-Sandte W; Pahernik SA; Ramadori G; Braulke T; Hartmann H 《Carcinogenesis》1998,19(12):2121-2128