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31.
Lesions of the articular surfaces of the knee have been managed by various techniques over the last 50 years. Surgical management has involved: excising the damaged area, refashioning the underlying bone to produce a fibrous response, and introducing allograft, autograft and synthetic materials to encourage a repair matrix. The techniques and their pitfalls are reviewed and discussed, and suggestions made as to the direction of future studies for the repair of osteochondral lesions in the painful knee. 相似文献
32.
33.
Owen L Woodman Patchareewan Pannangpetch 《Clinical and experimental pharmacology & physiology》1996,23(1):50-56
- 1 The aim of this study was to investigate whether endothelin-l (ET-1)-induced constriction of large and small coronary arteries in the anaesthetized greyhound is modulated by the endogenous release of nitric oxide or prostanoids.
- 2 ET-1 (1–100 ng/kg) and the α1-adrenoceptor agonist phenylephrine (0.5-2 pg/kg), when injected directly into the circumflex coronary artery, caused dose-dependent decreases in epicardial coronary artery diameter and coronary vascular conductance without affecting systemic arterial pressure or the rate and force of cardiac contraction.
- 3 Inhibition of NO synthesis with N-nitro-L-arginine (NOLA, 5 mg/kg, i.c.) decreased coronary artery diameter, coronary conductance and heart rate and increased arterial pressure. The coronary vasoconstrictor response to ET-1 was unaffected by NOLA. By contrast, NOLA significantly increased the phenylephrine-induced constriction of the epicardial coronary artery but not the resistance vessels.
- 4 Indomethacin (5 mg/kg, i.v.), an inhibitor of cyclo-oxygenase, significantly decreased epicardial coronary artery diameter but did not affect coronary conductance. Indomethacin had no effect on the coronary vascular responses to ET-1 or phenylephrine. Combined treatment with NOLA plus indomethacin also failed to affect the coronary vasoconstrictor effects of ET-1.
- 5 Basal release of NO and vasodilator prostanoids modulated resting coronary vascular tone but did not Influence the vasoconstrictor responses to endothelin in either large or small coronary arteries.
34.
Frequency of the ATM IVS10-6T→G variant in Australian multiple-case breast cancer families
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35.
Hypospadias trends in two US surveillance systems 总被引:6,自引:0,他引:6
OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted. 相似文献
36.
P. I. Blomfield Fellow R. J. Lancashire Computer Operator † C. B. J. Woodman Professor ‡ 《BJOG : an international journal of obstetrics and gynaecology》1998,105(5):486-492
Objective To determine if use of a detailed risk factor profile accurately predicts the presence of cytological abnormality of the cervix or improves the appropriateness of referral for colposcopic assessment when women are found to have these abnormalities.
Design Cross-sectional survey.
Setting Family planning clinic.
Population 1219 consecutive women, aged between 15 and 19 years, attending for contraceptive advice. Variables included age, social class, educational status, hormonal and obstetric history, smoking and alcohol habits, history of sexually transmitted diseases, the age of first intercourse, number of sexual partners, duration of each relationship, frequency of intercourse, contraception used and the age of each partner.
Main outcome measures Presence or absence of cytological abnormality and the presence or absence of histological abnormality in those with cytological abnormality referred for colposcopic assessment.
Results Univariate analysis confirmed many of the known associations of cervical abnormality. Discriminant analysis identified five independent significant predictors of cytological abnormality and four independent predictors of dyskaryotic cytology. At best models, derived from identified variables correctly predicted 10.1 % of individuals with cytological abnormality and 13.5% of those with dyskaryotic cytology. Of those referred for colposcopic assessment because of abnormal cytology, models were able to predict 23.5% of those with histological evidence of cervical intraepithelial neoplasia.
Conclusions Despite the availability of detailed information regarding the known correlates of cervical neoplasia in this age group, it was not possible to identify the majority of women with cervical abnormality. It is concluded that the strength of these associations is not sufficient to allow useful prediction of membership of a high risk group. 相似文献
Design Cross-sectional survey.
Setting Family planning clinic.
Population 1219 consecutive women, aged between 15 and 19 years, attending for contraceptive advice. Variables included age, social class, educational status, hormonal and obstetric history, smoking and alcohol habits, history of sexually transmitted diseases, the age of first intercourse, number of sexual partners, duration of each relationship, frequency of intercourse, contraception used and the age of each partner.
Main outcome measures Presence or absence of cytological abnormality and the presence or absence of histological abnormality in those with cytological abnormality referred for colposcopic assessment.
Results Univariate analysis confirmed many of the known associations of cervical abnormality. Discriminant analysis identified five independent significant predictors of cytological abnormality and four independent predictors of dyskaryotic cytology. At best models, derived from identified variables correctly predicted 10.1 % of individuals with cytological abnormality and 13.5% of those with dyskaryotic cytology. Of those referred for colposcopic assessment because of abnormal cytology, models were able to predict 23.5% of those with histological evidence of cervical intraepithelial neoplasia.
Conclusions Despite the availability of detailed information regarding the known correlates of cervical neoplasia in this age group, it was not possible to identify the majority of women with cervical abnormality. It is concluded that the strength of these associations is not sufficient to allow useful prediction of membership of a high risk group. 相似文献
37.
Gonzales AJ; Christensen JG; Preston RJ; Goldsworthy TL; Tlsty TD; Fox TR 《Carcinogenesis》1998,19(7):1173-1183
38.
Guo RJ; Wang Y; Kaneko E; Wang DY; Arai H; Hanai H; Takenoshita S; Hagiwara K; Harris CC; Sugimura H 《Carcinogenesis》1998,19(9):1539-1544
Mutations in the transforming growth factor beta type II receptor
(TGFbetaRII) gene have been detected in several human cancer types
exhibiting microsatellite instability. Using intron primers previously
reported for examination of the entire coding region of the TGFbetaRII
gene, 29 sporadic gastric cancers were screened with non-radioactive single
strand conformation polymorphism and subsequent DNA sequencing analysis.
Mutations of the TGFbetaRII gene were detected in three out of 29 tumors
(10%). Two cases showed deletions in a polyadenine tract in both alleles
and was positively associated with replication error. One case had an
insertion of GA dinucleotide sequence in one allele. Mutations of the
TGFbetaRII gene were restricted to exon 3 and other coding regions were not
affected. Loss of heterozygosity was detected by analyzing a polymorphic
site in intron 2. Three out of nine (33%) informative cases, which were all
of intestinal type and advanced cases, showed loss of heterozygosity but
neither TGFbetaRII mutation nor replication error was found in these cases.
Immunoreactivity of TGFbetaRII in tumor tissues was reduced to a different
extent in the gastric cancer with genetically abnormal transforming growth
factor. Although the numbers studied are small, homozygous (A)10 deletion
or loss of heterozygosity of TGFbetaRII is involved in tumorigenesis and
progression of at least some part of sporadic gastric cancer.
相似文献
39.
40.
Tumour cell growth may be accelerated by protein kinase C (PKC) agonists
such as phorbol esters and receptor tyrosine kinases, but receptor tyrosine
kinases are in turn desensitized to growth factors by PKC agonists. To
clarify this apparent PKC bifunctionality, we have used phosphoantibodies
to determine the relationship between PKC- dependent phosphorylation events
affecting the ErbB2 oncoprotein in G8/DHFR 3T3 cells. Neither the kinetics
nor the extent of phorbol- induced juxtamembrane domain (Thr686)
phosphorylation vary directly with C-terminal (Tyr1222) dephosphorylation,
with Tyr1222 continuing to be dephosphorylated long after Thr686
phosphorylation has also declined. Platelet-derived growth factor (PDGF)
mimics the short-term effects of phorbol on Thr686 and Tyr1222
phosphorylation, and confocal microscopy reveals that both of these PKC
agonists induce rapid internalization of PKC-modified ErbB2. Phorbol causes
sustained cytoplasmic accumulation of PKC-phosphorylated receptors,
however, whereas PDGF triggers the appearance of this ErbB2 subset only
briefly. Metabolic labelling and co-precipitation studies fail to implicate
heterologous molecules in either the tyrosine dephosphorylation or
internalization of PKC-modified ErbB2. Taken in the context of earlier
juxtamembrane domain mutagenesis studies, these findings indicate that
phorbol-activated PKC may desensitize growth factor receptors to
extracellular ligands solely by triggering sustained receptor
internalization. We submit that PKC-dependent juxtamembrane domain
phosphorylation represents a physiological mechanism for shortening the
duration and enhancing the specificity of growth factor signalling by
promoting internalization of liganded and unliganded receptors,
respectively.
相似文献