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91.
Effect of exercise on physiological age-related change at mouse neuromuscular junctions 总被引:1,自引:0,他引:1
To determine the effect of endurance exercise on physiological age-related change at the mouse neuromuscular junction (NMJ), synaptic function was studied for extensor digitorum longus (EDL) and soleus muscles of three C57BL/6J mouse groups, 1) young adult control (YC: 10 months), 2) old control (OC: 20 months), and 3) old mice which exercised (OE: 20 months) since young-adulthood. Electrophysiological properties were studied with intracellular recording techniques. Safety margin was studied by measuring indirect isometric twitch tension in different calcium concentrations. With sedentary aging, EDL and soleus quantal contents increased. Following aging combined with 10 months of exercise, the EDL quantal contents in OE and YC animals were similar. In contrast, soleus quantal content was greater in OE than in YC animals. Determined safety margins were OC greater than YC = OE for EDL, and OC = YC = OE for soleus. This is the first study to indicate that physiological age-related changes at NMJs of EDL and soleus muscles are affected differently by endurance exercise. Exercise prevented all physiological age-related changes in EDL NMJs but not in soleus NMJs, this suggests that EDL changes are associated with inactivity during aging, while soleus changes are "fundamental" age changes. 相似文献
92.
Hemodynamic responses to hypoxia and hypercapnia during acute normovolemic hemodilution in anesthetized cats 总被引:1,自引:0,他引:1
The present study was undertaken to evaluate the effects of hypoxia and hypercapnia on circulatory parameters during acute normovolemic hemodilution. Cats anesthetized with a mixture of alpha-chloralose and urethane were maintained by positive pressure ventilation. Muscles were paralysed by intramuscular vecuronium (0.1 mg/kg) to eliminate reflex respiratory movements. Cats were exposed to hypoxia (12% O(2) and 7% O(2)) and hypercapnia (4% CO(2) and 7% CO(2)) at normal hematocrit (Ht 40.1 +/- 2.8%) and then at graded levels of normovolemic hemodilution (Ht 24.0 +/- 2.0% and Ht 13.0 +/- 1.5%, respectively). Left ventricular pressure (LVP), LV dP/dt(max), arterial blood pressure (ABP), heart rate (HR), and right atrial pressure (RAP) were recorded on a polygraph. Cardiac output (CO) was measured using a cardiac output computer. Hemodilution per se did not produce any significant change in ABP, RAP or LV dP/dt(max), however, it produced a significant rise in HR and a significant fall in total peripheral resistance (TPR). Exposure to hypoxic gas mixtures caused significant increases in HR and CO at control Ht; but after hemodilution it caused the reverse effects. Hypercapnia did not produce any significant effect on ABP, LV dP/dt(max) or RAP either at control Ht or after hemodilution. Hypercapnia produced a fall in HR, CO and stroke volume (SV) at normal Ht and percent fall in HR response was enhanced following hemodilution. The reversal of chronotropic response to hypoxia and enhanced bradycardia response to hypercapnia, under conditions of acute normovolemic hemodilution would be deleterious as the tissues would become more hypoxic. Such a response may be attributed to altered control mechanisms under such conditions of severe stress. 相似文献
93.
Mohammad A. Karim Koji Suzuki Kazuyoshi Fukai Jangsuk Oh Deborah L. Nagle Karen J. Moore Ernest Barbosa Tzipora Falik‐Borenstein Alexandra Filipovich Yasushi Ishida Sirpa Kivrikko Christoph Klein Friedmar Kreuz Alex Levin Hiroaki Miyajima Jose R. Regueiro Carolyn Russo Eiichiro Uyama Outi Vierimaa Richard A. Spritz 《American journal of medical genetics. Part A》2002,108(1):16-22
Chediak‐Higashi syndrome (CHS) is a rare autosomal recessive disorder characterized by severe immunologic defects, reduced pigmentation, bleeding tendency, and progressive neurological dysfunction. Most patients present in early childhood and die unless treated by bone marrow transplantation. About 10–15% of patients exhibit a much milder clinical phenotype and survive to adulthood, but develop progressive and often fatal neurological dysfunction. Very rare patients exhibit an intermediate adolescent CHS phenotype, presenting with severe infections in early childhood, but a milder course by adolescence, with no accelerated phase. Here, we describe the organization and genomic DNA sequence of the CHS1 gene and mutation analysis of 21 unrelated patients with the childhood, adolescent, and adult forms of CHS. In patients with severe childhood CHS, we found only functionally null mutant CHS1 alleles, whereas in patients with the adolescent and adult forms of CHS we also found missense mutant alleles that likely encode CHS1 polypeptides with partial function. Together, these results suggest an allelic genotype–phenotype relationship among the various clinical forms of CHS. © 2002 Wiley‐Liss, Inc. 相似文献
94.
Amini-Bavil-Olyaee S Sarrami-Forooshani R Mahboudi F Sabahi F Adeli A Noorinayer B Azizi M Reza Zali M 《Journal of medical virology》2005,75(2):227-234
Hepatitis B virus (HBV) is one of the major causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually. Eight genotypes of HBV, A to H, have been described on the basis of similarity of the complete genomes sequence. Although, it is reported that the predominant HBV genotype in the Mediterranean area and the middle east is genotype D, there are no reports on HBV genotypes prevalent in Iran. In this study, the C and S regions of HBV from 26 chronic hepatitis B Iranian patients were amplified and sequenced. Phylogenetic analysis revealed that all Iranian HBV isolates sequences were classified into genotype D with bootstrap values of 100%, 73%, and 100% (1,000 replicates each) for S, C, and preS2 regions, respectively. The mean percent intra-distance of S and C regions were 0.8% and 2.3%, respectively. The mean percent inter-distance of S and C regions between Iranians and genotype D isolates were 1.7% and 3.0%, respectively, and the range of mean percent nucleotide distance of S and C regions between Iranians and the other reference isolates were 7.9%-17.5% and 4.8%-14.7%, respectively. Thirteen out of 23 HBV C region sequences showed nucleotide "A" at position 1896 (precore mutant) in C region. Nucleotide 1858 showed presence of "T" in all isolates. No insertion or deletion was found in both regions. SimPlot and BootScanning analyses did not show any recombination between Iranian isolates and other genotypes in both regions. 相似文献
95.
Santos RL Wajid M Khan MN McArthur N Pham TL Bhatti A Lee K Irshad S Mir A Yan K Chahrour MH Ansar M Ahmad W Leal SM 《Human mutation》2005,26(4):396
Though many hearing impairment genes have been identified, only a few of these genes have been screened in population studies. For this study, 168 Pakistani families with autosomal recessive hearing impairment not due to mutations in the GJB2 (Cx26) gene underwent a genome scan. Two-point and multipoint parametric linkage analyses were carried out. Twelve families had two-point or multipoint LOD scores of 1.4 or greater within the transmembrane cochlear expressed gene 1 (TMC1) region and were subjected to further screening with direct DNA sequencing. Five novel putatively functional non-synonymous sequence variants, c.830A>G (p.Y277C), c.1114G>A (p.V372M), c.1334G>A (p.R445H), c.2004T>G (p.S668R), and c.2035G>A (p.E679K), were found to segregate within seven families, but were not observed in 234 Pakistani control chromosomes. The variants c.830A>G (p.Y277C), c.1114G>A (p.V372M), and c.1334G>A (p.R445H) occurred at highly conserved regions and were predicted to lie within hydrophobic transmembrane domains, while non-synonymous variants c.2004T>G (p.S668R) and c.2035G>A (p.E679K) occurred in extracellular regions that were not highly conserved. There is evidence that the c.2004T>G (p.S668R) variant may have occurred at a phosphorylation site. One family has the known splice site mutation c.536 -8T>A. The prevalence of non-syndromic hearing impairment due to TMC1 in this Pakistani population is 4.4% (95%CI: 1.9, 8.6%). The TMC1 protein might have an important function in K(+) channels of inner hair cells, which would be consistent with the hypothetical structure of protein domains in which sequence variants were identified. 相似文献
96.
Haseeb Khan Ahmad Saleh Al Deeb Khalaf Al Moutaery Mohammad Tariq 《Experimental and toxicologic pathology》2003,55(2-3):181-186
A direct association between aging and drug-induced dyskinesia has been reported by several investigators. Iminiodipropionitrile (IDPN), a prototype nitrile compound produces a motor syndrome in rodents, which resembles neuroleptic drug induced dyskinesia. In this investigation attempt has been made to study the effect of age on IDPN induced vestibular hair cell degeneration and resulting dyskinetic syndrome. Male Wistar rats aged 3, 6 and 12 weeks received IDPN in the doses of 0, 200 and 400 mg/kg, intraperitoneally for 3 consecutive days. IDPN-induced dyskinesia was assessed using a behavioral testing battery on days 3, 4, 5, 6, 7, 14, 21 and 28. The rats were sacrificed on day 28; temporal bones were excised for vestibular histopathology and sera were collected for measuring the indices of oxidative stress (glutathione and conjugated dienes). IDPN in the dose of 200 mg/kg produced dyskinesia in 12 weeks old rats, but failed to do so in 3 and 6 weeks old rats. The high dose of IDPN (400 mg/kg) caused dyskinesia in all age groups, however, its onset and severity were age-dependent. Older rats showed an early onset and significantly high incidence of dyskinesia as compared to younger rats. The susceptibility of rats to IDPN-induced behavioral deficits was proportional to oxidative stress and degeneration of sensory hair cells in the crista ampullaris. 相似文献
97.
Mohammad Aftabuddin Ichiro Yamadori Tadashi Yoshino Eisaku Kondo Tadaatsu Akagi 《Pathology international》1995,45(6):422-429
The relationship between the number of apoptotic cells and the expression of apoptosis-related antigens was examined In 56 cases of non-Hodgkin's lymphomas and in 10 cases of reactive hyperplastic lymph nodes (RHL). Apoptosis was visually quantified by the in situ end-labeling (ISEL) method, and the expression of Fas, Ley antigens and bcl-2 protein was examined by Immunohistochemistry. The expression of Ley antigen was observed in germinal centers of RHL and 45% of non-Hodgkin's lymphomas. The apoptotic cell count (AC) in follicular lymphomas was significantly less than that in diffuse lymphomas. The distribution pattern of apoptotic cells In follicular lymphomas was inverse to that in RHL. In follicular lymphomas, AC was lower in follicles than in inter-follicular areas. In contrast, AC was higher in follicles than in Interfollicular areas in RHL. Ley antigen-positive lymphomas showed a significantly higher AC than the negative cases. The Fas antigen-positive lymphomas showed a higher AC than the negative cases. However, AC in bcl-2 protein-positive and negative cases was not significantly different. These results suggest that Ley and Fas antigens appear to be involved in the apoptotic tendency of tumor cells in non-Hodgkin's lymphomas, whereas bcl-2 does not necessarily. 相似文献
98.
A novel frame shift mutation in the HMG box of the SRY gene in a patient with complete 46,XY pure gonadal dysgenesis. 总被引:1,自引:0,他引:1
Richard Kellermayer László Halvax Márta Czakó Mohammad Shahid Varinderpal S Dhillon Syed Akhtar Husain Norbert Süle Eva G?m?ri Mariann Mammel Gy?rgy Kosztolányi 《Diagnostic molecular pathology》2005,14(3):159-163
Pure gonadal dysgenesis or Swyer syndrome is a sex-reversal disorder resulting from embryonic testicular regression sequences especially during the first few weeks of fetal life and is induced by mutations in the SRY gene. In the present report, we describe a nonmosaic XY sex-reversed female with pure gonadal dysgenesis. Molecular analysis using sequential PCR to detect Y chromosomal microdeletions showed the presence of SRY, ZFY and AZFa, b and c regions. Automated sequencing of the SRY region revealed a new mutation (deletion of A (adenine) in codon 82 at position +244), leading to a frame shift mutation within the helix I of the HMG-box domain. This mutation generates a truncated protein and is very likely to produce an impairment of SRY DNA binding activity. The present findings further support the functional importance of the putative DNA binding activity of the SRY HMG-box domain. 相似文献
99.
Shahid M Dhillion VS Jain N Hedau S Diwakar S Sachdeva P Batra S Das BC Husain SA 《Molecular human reproduction》2004,10(7):521-526
100.