全文获取类型
收费全文 | 513993篇 |
免费 | 33349篇 |
国内免费 | 614篇 |
专业分类
耳鼻咽喉 | 6893篇 |
儿科学 | 16843篇 |
妇产科学 | 13521篇 |
基础医学 | 85014篇 |
口腔科学 | 14477篇 |
临床医学 | 44339篇 |
内科学 | 93605篇 |
皮肤病学 | 12155篇 |
神经病学 | 36181篇 |
特种医学 | 18453篇 |
外国民族医学 | 63篇 |
外科学 | 77064篇 |
综合类 | 8471篇 |
一般理论 | 118篇 |
预防医学 | 38966篇 |
眼科学 | 12134篇 |
药学 | 40537篇 |
中国医学 | 1006篇 |
肿瘤学 | 28116篇 |
出版年
2018年 | 4930篇 |
2015年 | 4509篇 |
2014年 | 6060篇 |
2013年 | 9544篇 |
2012年 | 12871篇 |
2011年 | 14275篇 |
2010年 | 8300篇 |
2009年 | 7770篇 |
2008年 | 13698篇 |
2007年 | 14699篇 |
2006年 | 14943篇 |
2005年 | 14354篇 |
2004年 | 14048篇 |
2003年 | 13389篇 |
2002年 | 13268篇 |
2001年 | 24068篇 |
2000年 | 25078篇 |
1999年 | 20555篇 |
1998年 | 5426篇 |
1997年 | 4705篇 |
1996年 | 5042篇 |
1995年 | 4625篇 |
1994年 | 4318篇 |
1993年 | 4137篇 |
1992年 | 15727篇 |
1991年 | 16310篇 |
1990年 | 16422篇 |
1989年 | 15796篇 |
1988年 | 14575篇 |
1987年 | 14419篇 |
1986年 | 13597篇 |
1985年 | 12975篇 |
1984年 | 9627篇 |
1983年 | 8247篇 |
1982年 | 4559篇 |
1981年 | 4229篇 |
1979年 | 9418篇 |
1978年 | 6855篇 |
1977年 | 5772篇 |
1976年 | 5602篇 |
1975年 | 6396篇 |
1974年 | 7634篇 |
1973年 | 7130篇 |
1972年 | 6960篇 |
1971年 | 6685篇 |
1970年 | 6172篇 |
1969年 | 5888篇 |
1968年 | 5559篇 |
1967年 | 5012篇 |
1966年 | 4450篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
942.
J Pedraz E Daudén Y Delgado-Jiménez I García-Río A García-Díez 《Journal of the European Academy of Dermatology and Venereology》2006,20(6):702-706
BACKGROUND: There are numerous studies that individually evaluate the efficacy/effectiveness and toxicity of drugs in the systemic treatment of psoriasis. On the contrary, we can hardly find studies that compare each other. OBJECTIVE: To evaluate and compare the effectiveness and toxicity of mycophenolate mofetil and cyclosporin in chronic plaque psoriasis through a prospective, sequential, cross-over, non-randomized, two-phase, open-label study. PATIENTS/METHODS: Eight patients (five women and three men; mean age 57, range 35-78) with moderate-to-severe chronic plaque psoriasis were included in the study. They were treated with oral mycophenolate mofetil (30 mg/kg/day) over a period of 16 weeks. Following a variable washout period and after a new outbreak of the disease, oral cyclosporin was introduced at a dose of 4 mg/kg/day. During both treatment regimens, follow-up visits were performed at 3, 8 and 16 weeks. RESULTS: In both groups, the PASI started to decrease once treatment was begun. Cyclosporin was faster and statistically a lot more effective than mycophenolate mofetil, reaching a higher number of complete remissions and better percentages of PASI improvement from baseline (45.7%, 60.2% and 60.5% at 3, 8 and 16 weeks respectively for mycophenolate mofetil, and 89.7%, 95.3% and 95.3% respectively at the same intervals for cyclosporin). Cyclosporin was also more predictable in its action as the percentage of improvement along the follow-up visits had a much wider range for mycophenolate mofetil. Overall, the tolerability of both drugs was good. None of the patients had to discontinue treatment because of an adverse event. Two patients treated with cyclosporin showed increased plasma levels of creatinine. CONCLUSIONS: Cyclosporin is more effective, fast, and predictable in its effect than mycophenolate mofetil to control moderate-to-severe chronic plaque psoriasis. Both drugs are well tolerated in short courses of treatment. 相似文献
943.
AIM: The authors report an alternative procedure to carotid endarterectomy with internal carotid artery (ICA) segmental resection and end-to-end anastomosis associated with temporary shunt and venous patch angioplasty. Design: prospective cohort study. METHODS: Between May 1995 and December 2004, 192 patients underwent 200 primary CEAs for significant ICA stenosis. There were 131 men and 61 women with a mean age of 72.4+/-8.4 years. The indications for CEA were asymptomatic lesions in 51.5%, transient ischemic attack in 27.5% and stroke in 21%. RESULTS: The combined early morbidity and mortality rate was 2%. Two patients died, one due to fatal intracerebral hemorrhage and the second patient died of acute mesenteric ischemia. Neurological complications occurred in 2 patients, including 1 TIA and 1 nondisabling cerebrovascular accident. Non-neurological complications occurred in 26 patients (13.5%). Seventeen patients (8.8%) developed hypertension, 3 neck hematomas (1.5%) required surgical evacuation, 1 patient had reversible supraventricular arrhythmia (0.5%) and 1 patient had pneumonia (0.5%). Furthermore, 1 asymptomatic carotid occlusion was identified (0.5%) and 3 patients suffered permanent cranial nerve injury (1.5%). Mean follow-up was 45.7 months and there were 41 late deaths (21.8%). Survival rates at 1 and 5 years were 96.7+/-1.2% and 73.58+/-4.2%, respectively. CONCLUSIONS: CEA with ICA shortening and reanastomosis is a safe and reliable procedure without any increase in morbidity or mortality. 相似文献
944.
A R Krotovskaia M I Koloteva V Iu Luk'ianiuk I F Vil'-Vil'iams T M Bazhanova 《Aviakosmicheskaia i ekologicheskaia meditsina》2006,40(2):9-13
The subject of analysis was the data on +3 and +5 Gz tolerance of 130 civilian non-pilot applicants for cosmonauts (men and women, aged 23 to 55) gathered over the past 30 years. Length of the centrifuge arm was 7.25 meters and the total number of primary centrifuge runs was 309. For nearly every second of the applicants (46.7%) acceleration at +5 Gz was an ordeal causing distinct vascular or coronary decompensation. Thus, 29.7% exhibited various combinations of brief visual disturbances, tachycardia, tachypnea, and systolic arterial pressure in the shoulders; in 17%, visual disturbances and/or their precursors were combined with exaggerated cardio-vascular functional parameters, arrhythmia, and serious vegetative disorders. Most of those who had failed to endure the first centrifugation were unable to improve G tolerance during next runs; indeed, they showed negative G-tolerance dynamics. G intolerance grew in significance or was exacerbated by new disorders and their combinations. These results testify against exposure of non-pilot applicants for cosmonauts to +5 G, during the primary medical screening. 相似文献
945.
946.
T Gloudemans I Pospiech L T Van Der Ven C J Lips H Schneid W Den Otter J S Sussenbach 《Cancer research》1992,52(23):6516-6521
Previously we have shown that expression of the insulin-like growth factor II (IGF-II) gene in 36 normal smooth muscle tissues (myometria) and 26 benign smooth muscle tumors (leiomyomas) was detectable by Northern blot analysis but that the RNA levels were low. In 9 of 20 malignant smooth muscle tumors (leiomyosarcomas) IGF-II gene expression was also low or absent, while in 11 of 20 the IGF-II gene was abundantly expressed. In 32 of these tissues we have now studied the DNA methylation state of the IGF-II gene. For the analysis of overall methylation of the gene the restriction endonucleases HpaII and MspI were used. In normal smooth muscle and in leiomyomas the IGF-II gene appeared to be methylated. In leiomyosarcomas with low IGF-II gene expression the DNA was partly demethylated. In leiomyosarcomas with abundant IGF-II gene expression overall methylation of the DNA tended to be low. In addition, we have studied the methylation state of one particular CpG site in the IGF-II gene with the restriction endonuclease AvaII. The results of the latter analysis confirm the analysis with HpaII and MspI. In conclusion, in malignant smooth muscle tumors the data indicate an inverse correlation between CpG methylation and expression of the IGF-II gene. 相似文献
947.
A A Kushch Sh M Tugizov V I Simonov I V Timofeev N P Perminova E P Shuma? 《Voprosy virusologii》1991,36(4):275-277
Immunization of BALB/c mice with natural purified HIV antigen, fusion of spleen cells with myeloma cells and subsequent selection of hybrid clones using recombinant gag antigen of HIV gave hybridomas producing monoclonal antibodies (MCA) to HIV. The immune blotting method demonstrated that 3 clones interacted with protein p24 and 4 clones with protein p17 of HIV. Competitive EIA led to a conclusion that the resulting MCA detected at least 3 antigenic determinants in proteins, products of gag gene of HIV. The potentials of using these MCA for the detection of viral antigen in HIV-infected continuous cell lines were demonstrated. 相似文献
948.
F. Njaa T. Baekken D. Bjaamer J. I. Holme F. Korsrud O. Woxen A. K. Olsen 《Pediatric allergy and immunology》1992,3(1):39-42
Fifty–five children 6–16 years old with allergic rhinoconjunctivitis due to both birch and grass pollinosis were randomized into 2 parallel groups, treated in double–blind fashion with either levocabastinc (LEV) eye–drops twice daily plus placebo eyedrops twice daily or sodium cromoglycate (SCG) eyedrops 4 times daily for 3 months. Spersallerg® (antazolini chloride + tetryzolini chloride) eyedrops were allowed as rescue medicine. All children received basic treatment with an antihistamine (terfenadine) during the complete trial period, and a local nasal corticosteroid if needed. Eye symptoms were recorded daily by the patients and at 4 visits by the investigator, at start and after 4, 10 and 13 weeks. Pollen counts were performed and a blood sample was collected at start and end of the treatment. The global evaluation of treatment was similar for the 2 groups, and there was no significant difference in any effect parameter except for the symptom, itchy eyes, which had lower score in the SCG group as evaluated by the investigator after 4 weeks. On days with low pollen counts the patients in the SCG group had fewer days with moderate or severe eye symptoms. It is concluded that even though LEV and SCG eyedrops were given in addition to systemic treatment with an antihistamine, no consistently significant differences in clinical effect were found between the 2 treatment groups, but the SCG group experienced slightly less eye symptoms throughout the trial. LEV eye–drops appear safe in long–term treatment in children, and no signs of tachyphylaxis were recorded. 相似文献
949.
The purposes of the present study of chronic pain patients were to (a) assess whether cognitive and behavioral coping style is related to personality factors, (b) assess how coping styles differ across personality types, and (c) assess how outpatient interdisciplinary intervention affects the coping styles of various personality types. Four MMPI clusters (Depression/Pathological, V-type, Marginal Depression, and Marginal V-type) were derived using a hierarchical clustering procedure. Seventy subjects also completed the Coping Strategies Questionnaire before and after a 3-week outpatient pain management program. Pretreatment analyses indicated the Depression/Pathological and Marginal Depression groups used diverting attention less than either V-type group. The V-type group reported using praying/hoping significantly more than either of the marginal groups. At posttreatment the Depression/Pathological group used catastrophizing significantly more than either of the marginal groups. Results of pre-post analyses indicated that the Depression/Pathological group increased their use of diverting attention, reinterpreting pain sensations, and ignoring pain sensations, while decreasing catastrophizing. The V-type group increased their use of reinterpreting pain sensations, while decreasing praying/hoping and catastrophizing. Neither of the Marginal subtypes showed significant pre-post changes in coping strategies. These results suggest that different personality types use different pain coping strategies prior to multidisciplinary treatment. Groups showing more severe psychological distress, perhaps related to an underlying personality disorder, displayed greater changes in coping strategies with treatment, but remained more dysfunctional after treatment. These findings suggest that the alteration of coping strategies may be an important treatment effect needing more individualization to maximize treatment response.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
950.
Histological studies describe in detail the changes of the small arteries wall with controversial results concerning lumen narrowing during the aging process. In this study, the anatomic and the angiographic parameters of the medial and lateral lenticulostriate arteries were analysed in 64 carotid angiograms. Only 20% of the total number of lenticulostriate arteries were shown on angiograms. Collateral branches were rarely visible, especially those of medial group. The course of the lenticulostriate arteries was mostly straight or moderately tortuous. No significant differences were noted in any of the measured parameters when compared with the age (p greater than 0.05). It appears that age-related changes spread over external layers of small arteries, with no lumen narrowing or filling defect. 相似文献