全文获取类型
收费全文 | 612篇 |
免费 | 32篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 38篇 |
妇产科学 | 1篇 |
基础医学 | 76篇 |
口腔科学 | 17篇 |
临床医学 | 71篇 |
内科学 | 110篇 |
皮肤病学 | 20篇 |
神经病学 | 59篇 |
特种医学 | 121篇 |
外科学 | 36篇 |
综合类 | 12篇 |
预防医学 | 33篇 |
眼科学 | 1篇 |
药学 | 34篇 |
肿瘤学 | 33篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 14篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 20篇 |
2012年 | 9篇 |
2011年 | 16篇 |
2010年 | 34篇 |
2009年 | 37篇 |
2008年 | 14篇 |
2007年 | 27篇 |
2006年 | 19篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 10篇 |
2002年 | 15篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 35篇 |
1997年 | 37篇 |
1996年 | 30篇 |
1995年 | 29篇 |
1994年 | 11篇 |
1993年 | 19篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 19篇 |
1987年 | 15篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1957年 | 1篇 |
1953年 | 1篇 |
排序方式: 共有665条查询结果,搜索用时 15 毫秒
61.
Familial hemiplegic migraine: a clinical comparison of families linked and unlinked to chromosome 19 总被引:5,自引:0,他引:5
GM Terwindt RA Ophoff J Haan RR Frants MD Ferrari for the DMGRG 《Cephalalgia : an international journal of headache》1996,16(3):153-155
We compared the clinical characteristics of 50 patients from three unrelated families with familial hemiplegic migraine (FHM) linked to chromosome 19, with those of 20 patients from two families with FHM not linked to chromosome 19. We found no significant differences for age at onset, frequency and duration of attacks, duration of the paresis, and occurrence of basilar migraine symptoms. In the linked families, significantly more patients reported unconsciousness during attacks (39%, vs 15%; p<0.05) and provocation of attacks by mild head trauma (70% vs 40%; p< 0.05). In one linked family patients also displayed chronic progressive cerebellar ataxia, whereas in one unlinked family benign infantile convulsions occurred in addition to FHM. Interestingly, so far an association with cerebellar ataxia was only described in chromosome 19-linked families. FHM linked to chromosome 19 and FHM unlinked to chromosome 19 do not differ with respect to clinical features. 相似文献
62.
Saletu B Prause W Löffler-Stastka H Anderer P Brandstätter N Zoghlami A Saletu-Zyhlarz G Katschnig H 《Wiener klinische Wochenschrift》2003,115(7-8):246-254
Subjective health-related quality of life (HRQoL) was investigated in 100 patients with disturbed sleep (39 women aged 52 +/- 13 years and 61 men aged 53 +/- 10 years) referred to the sleep laboratory and compared with HRQoL in 100 normal healthy adults. Measurements included the Quality of Life Index (QLI) (Mezzich and Cohen), and objective (polysomnographic) and subjective (psychometric) quality of sleep and awakening. Statistical analysis (Mann-Whitney U-test) showed HRQoL to be significantly reduced in sleep disorders (SDs), with a more pronounced reduction in nonorganic than in organic SDs. Patients with nonorganic hypersomnia were more disturbed than those with nonorganic insomnia. Within organic SDs, patients with apnea were more disturbed than those with obstructive snoring. Out of ten elementary HRQoL components, seven were disturbed in SDs: physical well-being, psychological well-being, self-care and independent functioning, occupational functioning, interpersonal functioning, personal fulfillment, and overall quality of life. No differences between patients and normal healthy subjects where found in the components social support, community and services support or spiritual fulfillment. Patients suffering from nonorganic SDs had significantly worse scores in physical and psychological well-being and overall quality of life than those with organic SDs. Patients with both SDs and additional diagnoses of affective disorders had more profoundly reduced HRQoL than those with anxiety disorders. Follow-up of 51 patients (31 with nonorganic SDs and 20 with organic SDs) one year after sleep laboratory investigation and subsequent treatment found significantly improved HRQoL compared with pre-treatment. Moreover, patients diagnosed and treated in the sleep laboratory showed lower re-hospitalization rats. 相似文献
63.
Specificity of cytotoxic effector cells directed against trinitrobenzene sulfonate-modified syngeneic cells. Failure to recognize cell surface- bound trinitrophenyl dextran 下载免费PDF全文
PA Henkart A Schmitt-Verhulst GM Shearer 《The Journal of experimental medicine》1977,146(4):1068-1078
Mouse splenic lymphocytes and lymphoid tumor cells were modified with the trinitrophenyl (TNP) group either by treatment with trinitrobenzene sulfonate (TNBS) (which covalently modifies cell surface proteins) or with TNP stearoyl dextran (TSD) (which binds to the cell by noncovalent forces). These cell preparations were compared for their ability to: (a) sensitive syngeneic splenic lymphocytes leading to the generation of cytotoxic effector cells; (b) serve as lysable targets in a 4-h(51)Cr- release assay for effector cells generated in (a); and (c) act as blocking cells in the lysis of TNBS-medified targets lysed by TNP self effector cells generated in (a). In none of these three experimental systems did TSD-medified syngeneic spleen or H-2-matched tumor cells act either as a sensitizing immunogen or as a target antigen, despite the demonstration that quantitatively equivalent mounts of TNP were exposed on the cell surface in the TNBS- and TSD-modified cells. In contrast, TNBS-modified spleen cells sensitized syngeneic lymphocytes to generate effectors against TNBS-modified syageneic targets. Furthermore, TNBS- modified, H-2-matched cells served as specific lysable targets and as inhibiting cells for such effectors. These results indicate that the manner in which TNP is associated with the cell surface is important in the immunogenicity and antigenicity of hapten-modified syngeneic stimulating cells in generating H-2-associated cell-mediated lympholysis (CML) reactions. These findings raise the possibility that a covalent or at least a stable linkage with cell surface proteins (possibly H-2- controlled products) is important for immunological function. Furthermore, these observations do not favor the dual receptor model for H-2-restricted syngeneic CML if it is assumed in such a model that one receptor is specific for the TNP moiety and the second for unmodified self major histocompatibility products. 相似文献
64.
The present criteria for confirmation of human T-lymphotrophic virus types I and II (HTLV-I/II) infection in blood donors are based on seroreactivity to p24 (gag) and gp46 and/or gp61 (env) on Western blot (WB) and radioimmunoprecipitation assays (WB/RIPA). Any single band and other combinations are classified as indeterminate. This case report documents infection in a donor with a repeatedly indeterminate pattern. The blood donor was anti-HTLV-I/II positive on enzyme-linked immunoassay, and two sera taken 5 years apart were WB/RIPA-indeterminate (p19 and gp68 only). His donations in the interval were associated with transmission of HTLV-I to four of the six recipients available for study. Other recipients of blood from donors whose WB/RIPA results were indeterminate by present criteria should be examined to determine if additional patterns are at least occasionally associated with transmission. The likelihood that such donors are infected is important to those who are counseling them and making decisions concerning recipients of their bloody. 相似文献
65.
GM Repetto ML Guzmán A Puga JF Calderón CP Astete M Aracena M Arriaza T Aravena P Sanz 《Clinical genetics》2009,76(5):465-470
Patients with chromosome 22q11 deletion syndrome exhibit significant phenotypic variability. Epidemiologic data suggest a higher incidence in Hispanics, but limited clinical information is available from Latin-American patients. We describe the clinical features of Chilean patients with 22q11 deletion syndrome and compare their findings with those reported in large European, Japanese and US series. Data were obtained from 208 patients from five medical centers. Mean age at diagnosis was 5.2 years, with a median of 2.3 years. Congenital heart defects were present in 59.6%, lower than other large series that averaged 75.8%. Palate abnormalities were present in 79%, higher than previous reports averaging 56%. Patients with congenital heart disease were diagnosed earlier (median 0.3 years of age) than those without heart defects (median 5.6 years) and had greater mortality attributable to the syndrome (9.8% vs 2.4%, respectively). The differences in frequencies of major anomalies may be due to growing awareness of more subtle manifestations of the syndrome, differences in clinical ascertainment or the presence of modifier factors. These observations provide additional data useful for patient counseling and for the proposal of health care guidelines. 相似文献
66.
S Pierno GM Camerino V Cippone J-F Rolland J-F Desaphy A De Luca A Liantonio G Bianco JD Kunic AL George Jr D Conte Camerino 《British journal of pharmacology》2009,156(8):1206-1215
Background and purpose:
Statins and fibrates can produce mild to life-threatening skeletal muscle damage. Resting chloride channel conductance (gCl), carried by the ClC-1 channel, is reduced in muscles of rats chronically treated with fluvastatin, atorvastatin or fenofibrate, along with increased resting cytosolic calcium in statin-treated rats. A high gCl, controlled by the Ca2+-dependent protein kinase C (PKC), maintains sarcolemma electrical stability and its reduction alters muscle function. Here, we investigated how statins and fenofibrate impaired gCl.Experimental approach:
In rats treated with fluvastatin, atorvastatin or fenofibrate, we examined the involvement of PKC in gCl reduction by the two intracellular microelectrodes technique and ClC-1 mRNA level by quantitative real time-polymerase chain reaction. Direct drug effects were tested by patch clamp analysis on human ClC-1 channels expressed in human embryonic kidney (HEK) 293 cells.Key results:
Chelerythrine, a PKC inhibitor, applied in vitro on muscle dissected from atorvastatin-treated rats fully restored gCl, suggesting the involvement of this enzyme in statin action. Chelerythrine partially restored gCl in muscles from fluvastatin-treated rats but not in those from fenofibrate-treated rats, implying additional mechanisms for gCl impairment. Accordingly, a decrease of ClC-1 channel mRNA was found in both fluvastatin-and fenofibrate-treated rat muscles. Fenofibric acid, the in vivo metabolite of fenofibrate, but not fluvastatin, rapidly reduced chloride currents in HEK 293 cells.Conclusions and implications:
Our data suggest multiple mechanisms underlie the effect of statins and fenofibrate on ClC-1 channel conductance. While statins promote Ca2+-mediated PKC activation, fenofibrate directly inhibits ClC-1 channels and both fluvastatin and fenofibrate impair expression of mRNA for ClC-1. 相似文献67.
Clinical correlates of low-risk variants in FGFR2, TNRC9, MAP3K1, LSP1 and 8q24 in a Dutch cohort of incident breast cancer cases 总被引:1,自引:1,他引:0 下载免费PDF全文
Huijts PE Vreeswijk MP Kroeze-Jansema KH Jacobi CE Seynaeve C Krol-Warmerdam EM Wijers-Koster PM Blom JC Pooley KA Klijn JG Tollenaar RA Devilee P van Asperen CJ 《Breast cancer research : BCR》2007,9(6):R78-9
Introduction
Seven SNPs in five genomic loci were recently found to confer a mildly increased risk of breast cancer.Methods
We have investigated the correlations between disease characteristics and the patient genotypes of these SNPs in an unselected prospective cohort of 1,267 consecutive patients with primary breast cancer.Results
Heterozygote carriers and minor allele homozygote carriers for SNP rs889312 in the MAP3K1 gene were less likely to be lymph node positive at breast cancer diagnosis (P = 0.044) relative to major allele homozygote carriers. Heterozygote carriers and minor allele homozygote carriers for SNP rs3803662 near the TNCR9 gene were more likely to be diagnosed before the age of 60 years (P = 0.025) relative to major allele homozygote carriers. We also noted a correlation between the number of minor alleles of rs2981582 in FGFR2 and the average number of first-degree and second-degree relatives with breast cancer and/or ovarian cancer (P = 0.05). All other disease characteristics, including tumour size and grade, and oestrogen or progesterone receptor status, were not significantly associated with any of these variants.Conclusion
Some recently discovered genomic variants associated with a mildly increased risk of breast cancer are also associated with breast cancer characteristics or family history of breast cancer and ovarian cancer. These findings provide interesting new clues for further research on these low-risk susceptibility alleles. 相似文献68.
Identification of women with an increased risk of developing radiation-induced breast cancer: a case only study 下载免费PDF全文
Annegien Broeks Linde M Braaf Angelina Huseinovic Anke Nooijen Jos Urbanus Frans BL Hogervorst Marjanka K Schmidt Jan GM Klijn Nicola S Russell Flora E Van Leeuwen Laura J Van 't Veer 《Breast cancer research : BCR》2007,9(2):1-9
Introduction
Medroxyprogesterone acetate (MPA) induces estrogen receptor (ER)-positive and progesterone receptor (PR)-positive ductal invasive mammary carcinomas in BALB/c mice. We sought to reproduce this MPA cancer model in C57BL/6 mice because of their widespread use in genetic engineering. Within this experimental setting, we studied the carcinogenic effects of MPA, the morphologic changes in mammary glands that are induced by MPA and progesterone, and the levels of ER and PR expression in MPA-treated and progesterone-treated mammary glands. Finally, we evaluated whether the differences found between BALB/c and C57BL/6 mouse strains were due to intrinsic differences in epithelial cells.Methods
The carcinogenic effect of MPA was evaluated in C57BL/6 mice using protocols proven to be carcinogenic in BALB/c mice. In addition, BALB/c and C57BL/6 females were treated with progesterone or MPA for 1 or 2 months, and mammary glands were excised for histologic studies and for immunohistochemical and Western blot evaluation of ER and PR. Hormone levels were determined by radioimmunoassay. Isolated mammary epithelial cells were transplanted into cleared fat pads of 21-day-old female Swiss nu/nu mice or control congenic animals.Results
MPA failed to induce mammary carcinomas or significant morphologic changes in the mammary glands of C57BL/6 mice. The expression of ER-α and PR isoform A in virgin mice was surprisingly much higher in BALB/c than in C57BL/6 mammary glands, and both receptors were downregulated in progestin-treated BALB/c mice (P < 0.05). PR isoform B levels were low in virgin control mice and increased after progestin treatment in both strains. ER-β expression followed a similar trend. No differences in hormone levels were found between strains. Surprisingly, the transplantation of the epithelial mammary gland cells of both strains into the cleared fat pads of Swiss (nu/nu) mice abolished the mammary gland morphologic differences and the ER and PR differences between strains.Conclusion
C57BL/6 mammary glands are resistant to MPA-induced carcinogenesis and to hormone action. MPA and progesterone have different effects on mammary glands. Low ER-α and PR-A levels in untreated mammary glands may be associated with a low-risk breast cancer profile. Although we cannot at this time rule out the participation of other, untested factors, our findings implicate the stroma as playing a crucial role in the strain-specific differential hormone receptor expression and hormone responsiveness. 相似文献69.
Insomnia in depression: differences in objective and subjective sleep and awakening quality to normal controls and acute effects of trazodone 总被引:9,自引:0,他引:9
Saletu-Zyhlarz GM Abu-Bakr MH Anderer P Gruber G Mandl M Strobl R Gollner D Prause W Saletu B 《Progress in neuro-psychopharmacology & biological psychiatry》2002,26(2):249-260
Utilizing polysomnography (PSG) and psychometry, objective and subjective sleep and awakening quality was investigated in 11 drug-free patients (five females, six males) aged 35-75 years (mean age 54.1 +/- 11.4) suffering from nonorganic insomnia (F 51.0) related to a depressive episode (F 32) or recurrent depressive disorder (F 33). as compared with 11 age- and sex-matched normal controls (five females, six males) aged 36-75 years (mean age 53.0 +/- 13.5). PSG demonstrated decreased sleep efficiency, total sleep time (TST), total sleep period (TSP) and sleep stage S2, as well as increased wakefulness during TSP, early morning awakening, sleep latency to S1, S2, S3 and sleep stage S1 in depressed patients. Subjective sleep quality and the total score of the Self-Assessment of Sleep and Awakening Quality Scale (SSA) were deteriorated as were morning and evening well being, drive, mood and fine motor activity right. Evening and morning blood pressure, the O2 desaturation index and periodic leg movement (PLM) index were increased. In a subsequent acute, placebo-controlled cross-over design study, the acute effects of 100 mg of trazodone, a serotonin reuptake inhibitor with a sedative action due to 5-HT2 and alpha1 receptor blockade, were investigated in the patients. As compared with placebo, trazodone induced an increase in sleep efficiency (primary target variable), TST, TSP and SWS (S3 + S4), as well as a decrease in wakefulness during the TSP, early morning awakening and S2. There was no change in rapid eye movement (REM) sleep with the exception of an increase in the REM duration in minutes. Trazodone also caused an improvement in subjective sleep quality, affectivity, numerical memory and somatic complaints. All respiratory variables remained within normal limits. Critical flicker frequency and moming diastolic blood pressure were decreased. The present study demonstrated that depression induced significant changes in objective and subjective sleep and awakening quality, which were counteracted by 100 mg of trazodone, thus suggesting a key-lock principle in the treatment of depression. 相似文献
70.
Richter GM; Noeldge G; Palmaz JC; Roessle M; Slegerstetter V; Franke M; Gerok W; Wenz W; Farthman E 《Radiology》1990,174(3):1027