全文获取类型
收费全文 | 30613篇 |
免费 | 1968篇 |
国内免费 | 239篇 |
专业分类
耳鼻咽喉 | 230篇 |
儿科学 | 800篇 |
妇产科学 | 811篇 |
基础医学 | 4525篇 |
口腔科学 | 747篇 |
临床医学 | 2624篇 |
内科学 | 7405篇 |
皮肤病学 | 511篇 |
神经病学 | 2853篇 |
特种医学 | 932篇 |
外国民族医学 | 3篇 |
外科学 | 3370篇 |
综合类 | 296篇 |
一般理论 | 9篇 |
预防医学 | 2042篇 |
眼科学 | 330篇 |
药学 | 1999篇 |
1篇 | |
中国医学 | 109篇 |
肿瘤学 | 3223篇 |
出版年
2024年 | 32篇 |
2023年 | 267篇 |
2022年 | 514篇 |
2021年 | 1019篇 |
2020年 | 589篇 |
2019年 | 806篇 |
2018年 | 919篇 |
2017年 | 725篇 |
2016年 | 821篇 |
2015年 | 914篇 |
2014年 | 1181篇 |
2013年 | 1523篇 |
2012年 | 2488篇 |
2011年 | 2479篇 |
2010年 | 1377篇 |
2009年 | 1212篇 |
2008年 | 2011篇 |
2007年 | 1969篇 |
2006年 | 1807篇 |
2005年 | 1681篇 |
2004年 | 1575篇 |
2003年 | 1322篇 |
2002年 | 1217篇 |
2001年 | 473篇 |
2000年 | 448篇 |
1999年 | 476篇 |
1998年 | 243篇 |
1997年 | 220篇 |
1996年 | 184篇 |
1995年 | 129篇 |
1994年 | 127篇 |
1993年 | 117篇 |
1992年 | 231篇 |
1991年 | 205篇 |
1990年 | 171篇 |
1989年 | 180篇 |
1988年 | 114篇 |
1987年 | 161篇 |
1986年 | 109篇 |
1985年 | 78篇 |
1984年 | 96篇 |
1983年 | 57篇 |
1982年 | 44篇 |
1981年 | 45篇 |
1980年 | 42篇 |
1979年 | 65篇 |
1976年 | 37篇 |
1975年 | 33篇 |
1974年 | 38篇 |
1973年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
Michele D. Mignogna Stefano Fedele Lucio Lo Russo Lorenzo Lo Muzio 《Journal of oral pathology & medicine》2003,32(4):200-205
BACKGROUND: The recurrent chronic orofacial swelling caused by orofacial granulomatosis (OFG) can cause significant cosmetic and functional problems but can be prevented if the disease is diagnosed early and promptly treated. Although the enlargement of the lips is described to be the most common presenting complaint, the clinical onset of OFG may be characterized by minor associated mucosal and neurological manifestations, making early diagnosis very difficult or, sometimes, merely presumable. PATIENTS AND METHODS: We retrospectively analyzed the clinical manifestations of 19 patients with OFG, who were examined at our institution between 1998 and 2002, in order to determine their initial manifestations and presenting symptoms. RESULTS: A total of 10 patients showed classical recurrent enlargement of the lips (six lower; four upper) as presenting symptom. In the other nine patients, OFG onset was characterized by transient unilateral facial nerve palsy (two cases), intraoral manifestations (two cases), recurrent swelling of the periorbital area (two cases), of the chin (one case), of the zygomatic area (one case), and of the cheeks (one case). CONCLUSION: Our data underlined that OFG onset could be frequently characterized by widely variable, multiform, and temporary clinical findings. Involvement of atypical sites of the orofacial region and presence of single minor manifestations may occur as presenting symptoms, often preceding the development of traditional clinical findings. 相似文献
4.
5.
C W Scott D P Blowers P T Barth M M Lo A I Salama C B Caputo 《Journal of neuroscience research》1991,30(1):154-162
Three isoforms of human tau protein were compared for their abilities to induce microtubule assembly. The three isoforms, tau 3 (tau containing three microtubule-binding domains), tau 4 (tau containing four microtubule-binding domains) and tau 4L (tau containing four microtubule binding domains plus a 58-amino-acid insert near the N-terminus) were expressed in E. coli and purified using ammonium sulfate precipitation, ion exchange, and size exclusion chromatography. All three isoforms induced microtubule assembly at micromolar concentrations and showed similar critical concentrations for assembly of 0.4-0.45 microM. However, tau 4 induced microtubule formation at a rate five- to tenfold faster than either tau 3 or tau 4L. The rate of microtubule elongation seen with tau 4 was twofold greater than with tau 3 or tau 4L, suggesting that the faster rate of microtubule assembly seen with tau 4 was due, at least in part, to faster elongation. Tau 4 induced a greater number of microtubules to form at steady state than did tau 3 or tau 4L. The microtubules generated with each tau isoform had similar steady-state length distributions and were equally susceptible to cold-induced disassembly. These results indicate that the additional microtubule-binding domain in tau 4 enhances microtubule assembly, while the 58-amino-acid insert negates the stimulatory effect of the fourth microtubule-binding domain. 相似文献
6.
Cerebrovascular and metabolic perturbations in delayed heavy charged particle radiation injury 总被引:5,自引:0,他引:5
E H Lo K A Frankel R L Delapaz A Poljak K H Woodruff K M Brennan M H Phillips P E Valk G K Steinberg J I Fabrikant 《Brain research》1989,504(1):168-172
Focal heavy charged particle irradiation of the rabbit brain created defined lesions which were observable by nuclear magnetic resonance (NMR) and positron emission tomography (PET) imaging techniques. The lesions appeared approximately 9-11 months after left partial hemibrain irradiation with 30 Gy (230 MeV/u helium ions), and were restricted to the white matter tracts and deep perithalamic and thalamic regions. 82Rubidium PET and Gadolinium DTPA enhanced NMR imaging were used to detect blood-brain barrier perturbations. 18Fluordeoxyglucose PET studies demonstrated widespread decreases in cerebral glucose uptake in the cortex and thalamus of the irradiated hemisphere. NMR and PET imaging results correlated well with histological findings. Rabbits irradiated with 15 Gy did not demonstrate any abnormalities in the brain with sequential NMR scans through 14 months post-irradiation. 相似文献
7.
Cristina Benatti Silvia Alboni Giacomo Capone Daniela Corsini Federica Caggia Nicoletta Brunello Fabio Tascedda Joan M.C. Blom 《International journal of developmental neuroscience》2009,27(7):661-668
Protracted or recurrent pain and inflammation in the early neonatal period may cause long-lasting changes in central neural function. However, more research is necessary to better characterize the long-term behavioral sequelae of such exposure in the neonatal period. Objectives: (1) to study whether timing of postnatal exposure to persistent inflammation alters responsiveness to thermal pain in the adult animal; (2) to assess whether animals experiencing early postnatal chronic inflammation display altered anxiety related behavior; (3) to study the importance of genetic background. Newborn mice (outbred strain, CD1 and F1 hybrid strain, B6C3F1) received an injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1 or 14 (PND1; PND14) into the left hind paw. Pain to radiant heat and anxiety were examined in 12-week-old adult animals. Adult baseline PWL was significantly decreased in CD1 mice exposed to CFA on PND 1 and 14 as compared to their saline treated counterparts. B6C3F1 mice exposed to CFA on PND14 showed markedly reduced baseline PWL compared to the PND14 saline group. Persistent inflammation experienced by B6C3F1 mice on PND1 failed to affect baseline adult thermal responsiveness. Adult mice, CD1 and B6C3F1, displayed low anxiety traits only if they had been exposed to persistent inflammation on PND1 and not on PND14. Our research suggests a role for genetic background in modulating long-term behavioral consequences of neonatal persistent inflammation: the data support the hypothesis that pain experienced very early in life differentially affects adult behavioral and emotional responsiveness in outbred (CD1) and hybrid mice (B6C3F1). 相似文献
8.
9.
10.
Estrella Fernández Fabrellas Luis Almenar Bonet Silvia Ponce Pérez José Antonio Moro López Rafael Blanquer Olivas Antonio Salvador Sanz 《Archivos de bronconeumologia》2009,45(4):173-180
Introduction and objectiveWhen sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.Patients and methodsNT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.ResultsData for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular enddiastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.ConclusionsNT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist. 相似文献