全文获取类型
收费全文 | 530192篇 |
免费 | 27649篇 |
国内免费 | 496篇 |
专业分类
耳鼻咽喉 | 6685篇 |
儿科学 | 16925篇 |
妇产科学 | 12538篇 |
基础医学 | 92639篇 |
口腔科学 | 12357篇 |
临床医学 | 48506篇 |
内科学 | 95465篇 |
皮肤病学 | 11868篇 |
神经病学 | 34015篇 |
特种医学 | 19761篇 |
外国民族医学 | 53篇 |
外科学 | 78114篇 |
综合类 | 7611篇 |
现状与发展 | 2篇 |
一般理论 | 107篇 |
预防医学 | 38545篇 |
眼科学 | 11939篇 |
药学 | 41433篇 |
1篇 | |
中国医学 | 1126篇 |
肿瘤学 | 28647篇 |
出版年
2021年 | 3899篇 |
2018年 | 5734篇 |
2017年 | 4129篇 |
2016年 | 4875篇 |
2015年 | 5362篇 |
2014年 | 7123篇 |
2013年 | 10503篇 |
2012年 | 15587篇 |
2011年 | 17405篇 |
2010年 | 9966篇 |
2009年 | 8825篇 |
2008年 | 15723篇 |
2007年 | 17458篇 |
2006年 | 16955篇 |
2005年 | 16269篇 |
2004年 | 15884篇 |
2003年 | 15271篇 |
2002年 | 14788篇 |
2001年 | 22437篇 |
2000年 | 22974篇 |
1999年 | 18921篇 |
1998年 | 5232篇 |
1997年 | 4365篇 |
1996年 | 4398篇 |
1995年 | 4124篇 |
1992年 | 14416篇 |
1991年 | 15826篇 |
1990年 | 15952篇 |
1989年 | 15626篇 |
1988年 | 14309篇 |
1987年 | 14198篇 |
1986年 | 13168篇 |
1985年 | 12688篇 |
1984年 | 9395篇 |
1983年 | 8000篇 |
1982年 | 4178篇 |
1979年 | 8940篇 |
1978年 | 6382篇 |
1977年 | 5149篇 |
1976年 | 5505篇 |
1975年 | 6613篇 |
1974年 | 7422篇 |
1973年 | 7158篇 |
1972年 | 6597篇 |
1971年 | 6309篇 |
1970年 | 5887篇 |
1969年 | 5468篇 |
1968年 | 5161篇 |
1967年 | 4622篇 |
1966年 | 3963篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
J. S. Sarkissian A. A. Galoyan R. G. Kamalyan V. A. Chavushyan I. B. Meliksetyan M. V. Poghosyan O. V. Gevorkyan A. S. Hovsepyan Z. E. Avakyan S. A. Kazaryan M. K. Manucharyan 《Neurochemical Journal》2007,1(3):227-234
The changes in spike activity of single neurons of the compact part of the substantia nigra, evoked by nucleus caudatus stimulation under conditions of long-term registration of the single and multiple, isolated and combined actions of GABA, GABA-amide, glutamine, and ethanolamine-O-sulfate (EOS) were studied in albino rats. Inhibition of poststimulus activity under GABA action was recorded and the inhibitory effect of GABA-amide was revealed. Primary excitatory and subsequent inhibitory effects of glutamine in combination with EOS were shown. The subsequent administration of bacterial melanin, synthesized by a mutant culture of Bacillus thuringiensis (BT-M) evoked a clear-cut and prolonged excitatory reaction during all the combined actions of GABA, GABA-amide, glutamine, and EOS. Preliminary administration of BT-M abolished the inhibitory poststimulus effects of GABA, GABA-amide, and EOS, as well as glutamine-induced excitation. 相似文献
992.
V Brazzelli† F Prestinari† T Barbagallo† C Rona† E Orlandi‡ F Passamonti‡ F Locatelli§ M Zecca§ S Villani¶ G Borroni† 《Journal of the European Academy of Dermatology and Venereology》2007,21(3):384-387
BACKGROUND: Imatinib mesylate (IM), the first-line treatment of chronic myeloid leukaemia (CML), is a tyrosine kinase inhibitor that targets those proteins involved in BCR-ABL signal transduction in CML, c-kit (KIT) and platelet-derived growth-factor (PDGFR) receptor. The use of IM has been associated with cutaneous reactions. In the last 2 years numerous studies have focused the attention on hypopigmentations, depigmentations and photosensitivity developing after the initiation of IM therapy. OBJECTIVE: The aim of this study is to evaluate the effects of IM therapy on the skin pigmentation of five patients affected by CML. METHODS: Skin pigmentation measurements were performed with a Minolta CR-200 Chromameter. results: All the studied patients show the gradual lightening of the skin on unexposed areas over the treatment with IM. In particular, this explorative colorimetric study indicates the association between IM and skin depigmentation with a significant increase of luminance value (L*) (P = 0.001) and a significant decrease of the pigmentation value (b*) (P = 0.028). CONCLUSION: Even if we do not know the clinical significance of the skin depigmentation caused by IM, the regulatory role of KIT and its ligand stem cell factor in melanocyte development and survival seems to suggest an objective mechanism of action for IM in the pathogenesis of this cutaneous depigmentation. 相似文献
993.
Comparison of outcomes and donor-site morbidity in unilateral free TRAM versus DIEP flap breast reconstruction. 总被引:2,自引:0,他引:2
M V Schaverien A G B Perks S J McCulley 《Journal of plastic, reconstructive & aesthetic surgery》2007,60(11):1219-1224
BACKGROUND: At long-term follow up we cannot easily differentiate between patients who have undergone free transverse rectus abdominis musculocutaneous (TRAM) flap and deep inferior epigastric artery perforator (DIEP) flap breast reconstruction in terms of subjective functional limitations of daily activities. The aim of this study was to evaluate postoperative outcomes and long-term subjective functional deficit in patients following unilateral free TRAM compared with DIEP flap breast reconstruction. METHODS: Sixty consecutive patients who underwent unilateral autologous breast reconstruction were included in the study, 30 of whom had undergone a DIEP flap, and 30 a free TRAM flap. Surgical and postoperative outcome data were collected and a postal questionnaire was sent to each patient at least 6 months postoperatively consisting of a short functional assessment questionnaire and a Short Form 36 (SF-36) survey. RESULTS: We found no significant difference in postoperative outcomes or in the subjective ability to perform activities of daily living, including work, domestic activities, sports and hobbies, between patients who underwent TRAM flap breast reconstruction and those who underwent a DIEP flap, and no significant difference between the groups for scores on the physical functioning, role-physical, or bodily pain scales of the SF-36. CONCLUSION: We conclude that harvesting of the free TRAM flap results in no significant difference in postoperative outcomes or in the subjective ability to perform activities of daily living compared with the DIEP flap. 相似文献
994.
Pulmonary delivery of growth hormone using dry powders and visualization of its local fate in rats. 总被引:9,自引:0,他引:9
A dry powder aerosol formed of human growth hormone (hGH), lactose and dipalmitoylphosphatidylcholine was assessed for systemic delivery of the hormone in rats. The fate of the protein locally in the deep lung was examined post-delivery. The powder was prepared by spray-drying and presented a primary particle diameter of 4.4 microm and a tap density of 0.069 g/cm(3). The mass median aerodynamic diameter was 4.4 micron in the multi-stage liquid impinger at 60 l/min using a Spinhaler device. The emitted dose and fine particle fraction were 89% and 58%, respectively. Varying the airflow rate from 30 to 90 l/min had limited impact on aerosolization properties in vitro. No hGH dimers or glycation adducts were produced during formulation of the powder. hGH absorbed into the bloodstream with a time to peak of 23 and 52 min and with an absolute bioavailability of 23% and 8% following intratracheal insufflation of the dry powder and intratracheal spray-instillation of a solution of the hormone, respectively. Confocal imaging of rat lung revealed an intense uptake of fluorescein isothiocyanate (FITC)-hGH by alveolar macrophages as early as 1 h post-delivery. A dry powder aerosol made of selected GRAS excipients improved absorption of hGH from the lung over a simple solution. 相似文献
995.
AIMS: To investigate the association between estimated glomerular filtration rate (eGFR) and total and cardiovascular mortality in a population-based cohort of diabetic subjects. METHODS: A longitudinal study using a population-based district diabetes register comprising 3288 subjects in South Tees, UK. The eGFR was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Patients were stratified by baseline eGFR into five stages as per the National Kidney Foundation guidelines: Stage 1, eGFR > 90; Stage 2, eGFR 60-89; Stage 3, eGFR 30-59; Stage 4, eGFR 15-29; and Stage 5, eGFR < 15 ml/min per 1.73 m(2). Main outcome was all-cause and cardiovascular mortality between 1 January 1994 and 31 July 2004. RESULTS: At baseline, mean age (58.4 years) differed between groups. Persons with lower eGFR were older (P < 0.001). Thirty-six percent (n = 1193, males 56%) had died by 10 years (cardiovascular cause in 60%). Median follow-up was 10.5 years amounting to 28 342 person years. Stages 4 and 5 (eGFR 相似文献
996.
Dr. J.-T. Gräsner M. Fischer K. H. Altemeyer J. Bahr B. W. Böttiger V. Dörges R. Franz A. Gries H. Krieter M. Messelken T. Rosolski M. Ruppert T. Schlechtriemen J. Scholz J. Schüttler B. Wolke J. F. Zander 《Notfall & Rettungsmedizin》2005,8(2):112-115
Within the scope of the symposium “Rescue Medicine in Germany” (held at the Reisensburg near Ulm in 2002), the need for a standardized data acquisition set for prehospital cardiac arrest patients was identified. Therefore, the working group “Emergency Medicine” of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) created a nationwide data acquisition system for primary medical care in prehospital cardiac arrest patients treated with cardiopulmonary resuscitation procedures. The system is in full accordance with the “Utstein style.” Integration of this data acquisition system, for example into the “Dortmund protocol,” is providing a standardized data web base of all acquired prehospital data analyze and to compare processing and structural quality. As additional modules for this nationwide data web base system, an inhospital module “further clinical treatment” and a “long-term follow-up” module are currently in the developmental process. 相似文献
997.
G Titeca†§ F Poot†§ D Cassart‡ B Defays† D Pirard†§ M Comas† P Vereecken†¶†† V Verschaevec P Simon† M Heenen† 《Journal of the European Academy of Dermatology and Venereology》2007,21(6):771-776
BACKGROUND: Breast cancer is the most common cancer in women and therefore represents a major problem in public health. Data from patients' self-report questionnaires provide valuable information about the side-effects that patients may view as having a significantly detrimental impact on their quality of life (QOL) and yet are not always recognized as important by healthcare professionals. Cosmetology is a specific care for patients and there is actually no scientific evidence regarding effects on QOL for women with breast cancer. OBJECTIVE: The purpose of this study is to assess the impact of cosmetic care on QOL in breast cancer patients during chemotherapy and radiotherapy. METHODS: We developed a prospective, multicentre, randomized, controlled study including 27 patients. All the patients had to fill in a French-validated dermatologic specific quality-of-life questionnaire to compare the QOL of the two groups, the cosmetic group and the control group, at three different times of the adjuvant treatment. RESULTS: The results show a statistically significant difference between the cosmetic group and the control group in two areas of QOL: mood state and self-perception of the disease. CONCLUSION: This study emphasizes the interest of cosmetic care in breast cancer patients. However, further larger trials are needed to confirm this study. 相似文献
998.
A.M. Heugas A. Nummela M.A. Amorim V. Billat 《Journal of Science and Medicine in Sport》2007,10(5):280-287
It is difficult to interpret the training induced changes in middle-distance running, since numerous aerobic and anaerobic determinants of the performance are interdependent. Several aerobic and anaerobic tests are available but their results, particularly those from anaerobic tests, may be discordant, not providing univocal interpretation of training. The purpose of this study is to use a multidimensional approach to distinguish aerobic and anaerobic capacities assessed by two running tests on a track: the maximal anaerobic running test (MART) and V(O2max) tests. Eleven runners carried out two maximal tests on a synthetic track before and after a 4-week training period: (i) a maximal test to determine V(O2max), the velocity associated with V(O2max) (vV(O2max)) and the velocity at the lactate threshold (v(LT)), (ii) a maximal anaerobic running test to estimate anaerobic capacity. An all-out test run at v(LT)+50% of the difference between v(LT) and vV(O2max), known to be affected by both aerobic and anaerobic energy production, was used to test this approach. A principal components analysis (PCA) shows that two components (i.e., aerobic and anaerobic) explained 79% of the variation in the physiological variables. The PCA suggests that V(O2max) and MART tests assess the aerobic and the anaerobic capacities, respectively. In contrast, the performance in the all-out test is affected by both aerobic and anaerobic energy production. The PCA shows that v(LT) and DeltaP (difference between the maximal power of the MART and V(O2max)) are clear markers of the long-term endurance and the anaerobic capacity, respectively. This multidimensional approach can be a useful way to disentangle the aerobic and anaerobic components of track tests. 相似文献
999.
J-P Lefaucheur J-J Labat G Amarenco A-G Herbaut D Prat-Pradal J Benaim B Aranda M-C Arne-Bes V Bonniaud P-M Boohs K Charvier F Daemgen P Dumas J-P Galaup S Sheikh Ismael J Kerdraon P Lacroix D Lagauche E Lapeyre M Lefort A-M Leroi R-J Opsomer B Parratte J-G Prévinaire P Raibaut J-Y Salle M-C Scheiber-Nogueira J-M Soler M-F Testut C Thomas 《Clinical neurophysiology》2007,37(4):223-228
Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring. 相似文献
1000.
C V Patrick Onyeaka Christos Alexiou Gaetano Rocco David N Hopkinson S Kim Suvarna Peter C Braidley Tim J Locke 《The Journal of heart and lung transplantation》2005,24(8):1140-1142
Transplant pneumonectomy is a rarely performed procedure. It is occasionally carried out in the course of retransplantation. To our knowledge, resection of a transplanted lung without its replacement and with successful outcome in the adult has not been previously reported. We present a case of elective left transplant pneumonectomy in a 38-year-old man 6 years after left single-lung transplant. At 12 months after resection, the patient remains well, with good exercise tolerance. 相似文献