全文获取类型
收费全文 | 3683篇 |
免费 | 236篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 124篇 |
妇产科学 | 77篇 |
基础医学 | 600篇 |
口腔科学 | 40篇 |
临床医学 | 342篇 |
内科学 | 964篇 |
皮肤病学 | 75篇 |
神经病学 | 431篇 |
特种医学 | 73篇 |
外科学 | 267篇 |
综合类 | 5篇 |
预防医学 | 149篇 |
眼科学 | 37篇 |
药学 | 313篇 |
中国医学 | 2篇 |
肿瘤学 | 419篇 |
出版年
2023年 | 17篇 |
2022年 | 24篇 |
2021年 | 95篇 |
2020年 | 55篇 |
2019年 | 80篇 |
2018年 | 85篇 |
2017年 | 74篇 |
2016年 | 93篇 |
2015年 | 99篇 |
2014年 | 153篇 |
2013年 | 181篇 |
2012年 | 302篇 |
2011年 | 324篇 |
2010年 | 180篇 |
2009年 | 149篇 |
2008年 | 245篇 |
2007年 | 262篇 |
2006年 | 228篇 |
2005年 | 243篇 |
2004年 | 207篇 |
2003年 | 206篇 |
2002年 | 188篇 |
2001年 | 34篇 |
2000年 | 24篇 |
1999年 | 29篇 |
1998年 | 55篇 |
1997年 | 33篇 |
1996年 | 27篇 |
1995年 | 32篇 |
1994年 | 15篇 |
1993年 | 11篇 |
1992年 | 21篇 |
1991年 | 13篇 |
1990年 | 17篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 16篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1967年 | 2篇 |
1966年 | 3篇 |
排序方式: 共有3938条查询结果,搜索用时 265 毫秒
91.
Luca Masotti Grazia Panigada Giancarlo Landini Filippo Pieralli Francesco Corradi Salvatore Lenti Rino Migliacci Stefano Arrigucci Anna Frullini Maria Chiara Bertieri Stefano Tatini Alberto Fortini Irene Cascinelli Nicola Mumoli Stefano Giuntoli Alessandro De Palma Veronica De Crescenzo Michele Piacentini Giancarlo Tintori Alba Dainelli Giuseppa Levantino Plinio Fabiani Filippo Risaliti Roberta Mastriforti Michele Voglino Valentina Carli Simone Meini 《Journal of thrombosis and thrombolysis》2016,41(4):606-612
Prognostic stratification of acute pulmonary embolism (PE) remains a challenge in clinical practice. Simplified PESI (sPESI) score is a practical validated score aimed to stratify 30-day mortality risk in acute PE. Whether prognostic value of sPESI score differs according to sex has not been previously investigated. Therefore the aim of our study was to provide information about it. Data records of 452 patients, 180 males (39.8 %) and 272 females (60.2 %) discharged for acute PE from Internal Medicine wards of Tuscany (Italy) were analysed. sPESI was retrospectively calculated. Variables enclosed in sPESI score, all cause in-hospital mortality and overall bleedings were compared between sexes. Moreover, predictive ability of sPESI score as prognosticator of all cause in-hospital mortality was tested and compared between sexes. sPESI score 0 (low risk) was found in 17.7 % of males and 13.6 % of females (p = 0.2323). We didn’t find significant difference in sPESI scoring distribution. Age ≥80 years (51.4 vs. 33.8 %, p = 0.0003) and heart rate ≥110 bpm (23.5 vs. 14.4 %, p = 0.0219) were found significantly more prevalent in females, whereas active cancer (23.8 vs. 39.4 %, p = 0.0004) and cardio-respiratory diseases (19.8 vs. 27.7 %, p = 0.0416) were in males. All cause in-hospital mortality was 0 % in both genders for sPESI score 0, whereas it was 5.4 % in females and 13.6 % in males with sPESI score 1–2 (p = 0.0208) and 22 % in females and 19.3 % in males with sPESI score ≥3 (p = 0.7776). Overall bleedings were significantly more frequent in females compared with males (4.77 vs. 0.55 %, p = 0.0189). In females overall bleedings ranged from 2.7 % in sPESI score 0 to 6 % in sPESI score ≥3. Predictive ability of sPESI score as prognosticator of all cause in-hospital mortality was higher in females compared to males (AUC 0.72 vs. 0.67, respectively). In real life different co-morbidity burdens in females compared to males. Females seems to be at lower risk of all cause in-hospital mortality for sPESI score ≤2 but at higher risk of bleeding, irrespective from sPESI scoring. Predictive ability of sPESI score seems better in females. 相似文献
92.
Marc-Antoine de La Vega Grazia Caleo Jonathan Audet Xiangguo Qiu Robert A. Kozak James I. Brooks Steven Kern Anja Wolz Armand Sprecher Jane Greig Kamalini Lokuge David K. Kargbo Brima Kargbo Antonino Di Caro Allen Grolla Darwyn Kobasa James E. Strong Giuseppe Ippolito Michel Van Herp Gary P. Kobinger 《The Journal of clinical investigation》2015,125(12):4421-4428
BACKGROUND. Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historically, these outbreaks have been relatively small and geographically contained; however, the magnitude of the EBOV outbreak that began in 2014 in West Africa has been unprecedented. The aim of this study was to describe the viral kinetics of EBOV during this outbreak and identify factors that contribute to outbreak progression.METHODS. From July to December 2014, one laboratory in Sierra Leone processed over 2,700 patient samples for EBOV detection by quantitative PCR (qPCR). Viremia was measured following patient admission. Age, sex, and approximate time of symptom onset were also recorded for each patient. The data was analyzed using various mathematical models to find trends of potential interest.RESULTS. The analysis revealed a significant difference (P = 2.7 × 10–77) between the initial viremia of survivors (4.02 log10 genome equivalents [GEQ]/ml) and nonsurvivors (6.18 log10 GEQ/ml). At the population level, patient viral loads were higher on average in July than in November, even when accounting for outcome and time since onset of symptoms. This decrease in viral loads temporally correlated with an increase in circulating EBOV-specific IgG antibodies among individuals who were suspected of being infected but shown to be negative for the virus by PCR.CONCLUSIONS. Our results indicate that initial viremia is associated with outcome of the individual and outbreak duration; therefore, care must be taken in planning clinical trials and interventions. Additional research in virus adaptation and the impacts of host factors on EBOV transmission and pathogenesis is needed. 相似文献
93.
Association of RAMP1 rs7590387 With the Risk of Migraine Transformation Into Medication Overuse Headache 下载免费PDF全文
94.
Prevalence,severity and correlates of fatigue in newly diagnosed patients with myelodysplastic syndromes 下载免费PDF全文
Fabio Efficace Gianluca Gaidano Massimo Breccia Marianna Criscuolo Francesco Cottone Giovanni Caocci David Bowen Michael Lübbert Emanuele Angelucci Reinhard Stauder Dominik Selleslag Uwe Platzbecker Grazia Sanpaolo Anna Jonasova Francesco Buccisano Giorgina Specchia Giuseppe A. Palumbo Pasquale Niscola Chonghua Wan Huiyong Zhang Susanna Fenu Virginia Klimek Odile Beyne‐Rauzy Khanh Nguyen Franco Mandelli 《British journal of haematology》2015,168(3):361-370
The primary objective of this study was to investigate factors associated with fatigue severity in newly diagnosed patients with higher‐risk myelodysplastic syndromes (MDS). The secondary objectives were to assess symptom prevalence and to examine the relationships between fatigue, quality of life (QoL) and overall symptom burden in these patients. The analyses were conducted in 280 higher‐risk MDS patients. Pre‐treatment patient‐reported fatigue was evaluated with the Functional Assessment of Chronic Illness Therapy (FACIT)‐Fatigue scale and QoL was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire‐Core 30 (EORTC QLQ‐C30). Female gender (P = 0·018), poor performance status (i.e., ECOG of 2–4) (P < 0·001) and lower levels of haemoglobin (Hb) (P = 0·026) were independently associated with higher fatigue severity. The three most prevalent symptoms were as follows: fatigue (92%), dyspnoea (63%) and pain (55%). Patients with higher levels of fatigue also had greater overall symptom burdens. The mean global QoL scores of patients with the highest versus those with the lowest levels of fatigue were 29·2 [standard deviation (SD), 18·3] and 69·0 (SD, 18·8), respectively and this difference was four times the magnitude of a clinically meaningful difference. Patient‐reported fatigue severity revealed the effects of disease burden on overall QoL more accurately than did degree of anaemia. Special attention should be given to the female patients in the management of fatigue. 相似文献
95.
Rosa Paula Biscolla Clara Ugolini Mariangela Sculli Valeria Bottici Maria Grazia Castagna Cristina Romei Barbara Cosci Eleonora Molinaro Pinuccia Faviana Fulvio Basolo Paolo Miccoli Furio Pacini Aldo Pinchera Rossella Elisei 《Thyroid》2004,14(11):946-952
Papillary thyroid microcarcinoma (mPTC), is a very frequent incidental finding with a frequency varying from a few percent to 35% at postmortem histopathologic examinations. However, the presence of mPTC in patients undergoing thyroidectomy for multinodular goiter (MNG) and for Graves' disease (GD) has been found to be lower. Patients with medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) association have been published as anecdotal case reports, as well as kindred with familial MTC or multiple endocrine neoplasia (MEN) 2A with some members simultaneously affected by MTC and PTC. We studied the prevalence and the biological behavior of MTC associated with PTC, with particular attention to those cases in which a mPTC was incidentally found. Twenty-seven of 196 (13.8%) MTC cases showed an association with PTC and in particular 21 of 190 (11.05%) with an incidental mPTC. This percentage is higher than that reported in the literature on the association of mPTC with GD (2.8%-4.5%) and MNG (3%). Also the percentage of the more general association of MTC/PTC, not restricted to mPTC, found in our series (13.8%) is higher than that reported in studies that analyzed the prevalence of PTC (any size) in patients treated for MNG (7.5%). A similarly high percentage of MTC/PTC had not been reported before and in particular there are no reports on large series of MTC/PTC. We also analyzed the epidemiologic, clinical, and pathologic features of MTC associated and not associated with PTC without finding any difference. In particular the outcome of the MTC did not appear to be influenced by the presence of the PTC and the specific radioiodine treatments. Moreover, although we cannot completely exclude a shared pathogenic event as the cause of both MTC and PTC, the molecular analysis of RET gene alterations did not show any common mutation. 相似文献
96.
97.
98.
Jennifer VanderWeele Teresa Pollack Diana Johnson Oakes Colleen Smyrniotis Vidhya Illuri Priyathama Vellanki Kevin OLeary Jane Holl Grazia Aleppo Mark E. Molitch Amisha Wallia 《Journal of diabetes and its complications》2018,32(7):650-654
Aims
This study validated enterprise data warehouse (EDW) data for a cohort of hospitalized patients with a primary diagnosis of diabetic ketoacidosis (DKA).Methods
247 patients with 319 admissions for DKA (ICD-9 code 250.12, 250.13, or 250.xx with biochemical criteria for DKA) were admitted to Northwestern Memorial Hospital from 1/1/2010 to 9/1/2013. Validation was performed by electronic medical record (EMR) review of 10% of admissions (N?=?32). Classification of diabetes type (Type 1 vs. Type 2) and DKA clinical status were compared between the EMR review and EDW data.Results
Key findings included incorrect classification of diabetes type in 5 of 32 (16%) admissions and indeterminable classification in 5 admissions. DKA was not present, based on the review, in 11 of 32 (34%) admissions. DKA was not present, based on biochemical criteria, in 15 of 32 (47%) admissions.Conclusions
This study found that EDW data have substantial errors. Some discrepancies can be addressed by refining the EDW query code, while others, related to diabetes classification and DKA diagnosis, cannot be corrected without improving clinical coding accuracy, consistency of medical record documentation, or EMR design. These results support the need for comprehensive validation of data for complex clinical populations obtained through data repositories such as the EDW. 相似文献99.
Electrophysiological properties of mouse bone marrow c-kit+ cells co-cultured onto neonatal cardiac myocytes 总被引:2,自引:0,他引:2
Lagostena L Avitabile D De Falco E Orlandi A Grassi F Iachininoto MG Ragone G Fucile S Pompilio G Eusebi F Pesce M Capogrossi MC 《Cardiovascular research》2005,66(3):482-492
OBJECTIVE: Controversy about hematopoietic stem cells reprogramming into cardiac myocytes is currently supported by positive and negative findings. In fact, some reports have shown the ability of stem cells from the bone marrow (BM) to differentiate into cardiac myocytes and to contribute to myocardium repair, while others have reported the opposite. METHODS: C-kit(+) cells from mouse bone marrow were co-cultured onto neonatal cardiac myocytes. Hematopoietic stem cell-derived cells were analyzed by investigating the expression of cardiac markers and ion channels and by single-cell electrophysiological recordings. RESULTS: Groups of undifferentiated c-kit(+) cells displayed only outward currents. Co-cultured c-kit(+) stem cells on neonatal cardiac myocytes expressed cardiac markers and Na(+) and Ca(2+) voltage-gated ion channels. However, Na(+) and Ca(2+) currents were not detected by electrophysiological patch-clamp recordings even if caffeine and cyclopiazonic acid treatment showed the presence of intracellular calcium stores. This suggests that these channels, although expressed, were not functional and thus do not allow the coupling between excitation and contraction that is typical of cardiac myocytes. Nevertheless, co-cultured cells had a more hyperpolarized resting membrane potential and, at least in a subset of cells, displayed voltage-gated inward rectifier currents and outward currents. Co-cultured c-kit(+)-derived cells were not connected to surrounding cardiac myocytes through gap junctions. To induce a more pronounced differentiation, co-cultured cells were treated with BMP-4 and TGF-beta, two factors that were shown to trigger a cardiac myocyte differentiation pathway in embryonic stem (ES) cells. Even under these conditions, c-kit(+) cells did not differentiate into functionally active cardiac myocytes. However, TGF-beta/BMP-4-treated cells were hyperpolarized and showed and increased inward rectifier current density. CONCLUSIONS: Our study shows that mouse BM hematopoietic stem cells exhibit a limited plasticity to transdifferentiate into cardiac myocytes in culture. 相似文献