全文获取类型
收费全文 | 9494篇 |
免费 | 337篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 195篇 |
儿科学 | 297篇 |
妇产科学 | 293篇 |
基础医学 | 1904篇 |
口腔科学 | 116篇 |
临床医学 | 663篇 |
内科学 | 1295篇 |
皮肤病学 | 280篇 |
神经病学 | 1078篇 |
特种医学 | 429篇 |
外国民族医学 | 9篇 |
外科学 | 1539篇 |
综合类 | 21篇 |
一般理论 | 1篇 |
预防医学 | 350篇 |
眼科学 | 216篇 |
药学 | 641篇 |
中国医学 | 8篇 |
肿瘤学 | 505篇 |
出版年
2021年 | 75篇 |
2019年 | 87篇 |
2018年 | 94篇 |
2017年 | 91篇 |
2016年 | 139篇 |
2015年 | 112篇 |
2014年 | 148篇 |
2013年 | 226篇 |
2012年 | 371篇 |
2011年 | 355篇 |
2010年 | 243篇 |
2009年 | 194篇 |
2008年 | 382篇 |
2007年 | 390篇 |
2006年 | 389篇 |
2005年 | 400篇 |
2004年 | 423篇 |
2003年 | 420篇 |
2002年 | 373篇 |
2001年 | 258篇 |
2000年 | 280篇 |
1999年 | 236篇 |
1998年 | 75篇 |
1997年 | 63篇 |
1996年 | 69篇 |
1993年 | 59篇 |
1992年 | 136篇 |
1991年 | 141篇 |
1990年 | 145篇 |
1989年 | 123篇 |
1988年 | 110篇 |
1987年 | 84篇 |
1986年 | 91篇 |
1985年 | 108篇 |
1984年 | 97篇 |
1983年 | 71篇 |
1980年 | 58篇 |
1979年 | 67篇 |
1977年 | 60篇 |
1933年 | 73篇 |
1931年 | 74篇 |
1930年 | 95篇 |
1929年 | 85篇 |
1928年 | 67篇 |
1927年 | 72篇 |
1926年 | 77篇 |
1925年 | 73篇 |
1924年 | 75篇 |
1923年 | 63篇 |
1922年 | 58篇 |
排序方式: 共有9840条查询结果,搜索用时 437 毫秒
1.
2.
3.
Background Context
Long-term follow-up of patient-reported outcome measures (PROM) is essential in both modern spinal care and research. Lack of time and staff are commonly reported barriers to implementing long-term follow-up of PROM. Automated and digital follow-up systems for PROM collection are seeing widespread use, yet their validity and comparative effectiveness have never been evaluated.Purpose
The present study aimed to assess the validity of digital follow-up systems in comparison with the conventional paper-based follow-up (PB-FU).Study Design
This is a retrospective analysis of prospectively collected double follow-up data.Patient Sample
Patients who underwent lumbar spinal fusion for spondylolisthesis or degenerative disc disease between 2013 and 2016 were included in the study.Outcome Measures
The study determined the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain severity at baseline, 6 weeks, 12 months, and 24 months.Materials and Methods
After lumbar spinal fusion surgery, a double follow-up of PROM was carried out by conventional PB-FU during clinical visits, while simultaneously completing an automatically dispatched digital follow-up questionnaire. As the primary end point, we assessed the intraindividual discrepancy in PROM between PB-FU and automated digital follow-up (AD-FU).Results
Forty patients completed all parts of the dual follow-up trajectory and were analyzed. We detected no discrepancy in ODI or NRS for back and leg pain severity at any of the baseline, 6-week, 12-month, or 24 month follow-ups (all p>.05). This was confirmed in a sensitivity analysis.Conclusions
In an analysis of dual paper-based and digital follow-up after lumbar fusion surgery, patients report highly similar values using either method of follow-up. It appears that AD-FU without incentives produces lower response rates. To reassess the validity of these systems for data collection in spinal patient care, a prospective validation with higher statistical power is warranted. 相似文献4.
U. Ravens Michael O. Flüß Q. Li Herbert M. Himmel Erich Wettwer Michael Klockow Inge Lues 《Naunyn-Schmiedeberg's archives of pharmacology》1997,355(6):733-742
The thiadiazinone derivative [+]-EMD 60263 ((+)-5-(1-(α-ethylimino-3,4-dimethoxybenzyl)-1,2,3,4- tetrahydroquinoline-6-yl)-6-methyl-3,6-dihydro-2H-1,3,4
-thiadiazine-2-on) is a Ca2+-sensitizing agent with only minor phosphodiesterase inhibitory activity. Our aim was to characterize the inotropic and electrophysiological
effects of [+]-EMD 60263 and its enantiomer [-]-EMD 60264 in several cardiac muscle preparations. The Ca2+-sensitizing activity resided in the [+]-enantiomer only. [+]-EMD 60263 (3 μM) shifted the EC50 of Ca2+ for contractile activation of skinned fibers of pig heart from 2.41 μM to 0.73 μM, whereas [-]-EMD 60264 (30 μM) was ineffective.
In Langendorff-perfused guinea pig hearts, [+]-EMD 60263 and [-]-EMD 60264 induced concentration-dependent positive and negative
inotropic effects, respectively; both enantiomers reduced spontaneous heart rate but did not influence perfusion pressure.
The maximum increase in force of human atrial trabeculae was 35 % of pre-drug control with [+]-EMD 60263 in comparison to
113 % with forskolin. In guinea-pig papillary muscles, [+]-EMD 60263 and [-]-EMD 60264 had opposite inotropic responses, however,
both agents similarly prolonged action potential duration. Both enantiomers concentration-dependently blocked the rapidly
activating component IKr of the delayed rectifier in guinea-pig myocytes. The block saturated at potentials positive to +30 mV, closely resembling
the effects of the antiarrhythmic agent E-4031 which had been originally used to define IKr. It is concluded, that the positive inotropic action of [+]-EMD 60263 can be explained by prevalence of the Ca2+-sensitizing effect. The accompanying prolongation in action potential duration is caused by block of the IKr component of the delayed rectifier. While the inotropic effects are stereoselective, most of the electrophysiological actions
are clearly independent of sterical configuration. The combination of Ca2+-sensitizing with class-III antiarrhythmic action may provide an interesting pharmacological profile of potential therapeutic
use.
Received: 7 January 1997 / Accepted: 25 February 1997 相似文献
5.
Reported in this paper are postoperative results recorded from 120 patients, 3 years after selective proximal vagotomy for uncomplicated duodenal ulcer. There was no intraoperative lethality and no recurrence in 96.7 per cent of all cases, while Visick grades I on II were recorded from 98.2 per cent. Radiologically and gastroscopically detected pathological processes receded soon. Average postoperative reduction in acid secretion was 66.2 per cent in BAO and 46.8 per cent in MAO. Acid values re-increased thereafter, and three years later reduction rates still amounted to 43.7 per cent in BAO and 28.6 per cent in MAO. Indications for proximal gastric vagotomy are discussed in some detail. 相似文献
6.
We found that thirteen per cent of all head and neck malignomas are malignant lymphomas. In 75% of these cases the Non-Hodgkin type could be found. The major salivary glands were involved by the lymphoma in 55% out of 104 patients. Paraglandular lymph nodes of the parotid gland were affected as well as intraglandular lymph nodes and the lymphoid tissue within the gland proper. The submandibular gland normally shows an involvement only with its paraglandular lymph nodes. Two thirds of the Non-Hodgkin lymphomas located in the salivary glands were low-grade. In case of clinical suspicion of a malignant lymphoma, fine needle biopsy is required for cytological diagnosis. However, surgery is mandatory for histological diagnosis, not as a therapeutic measure. 相似文献
7.
U. Bolm-Audorff S. Brandenburg T. Brüning H. Dupuis R. Ellegast G. Elsner K. Franz H. Grasshoff V. Grosser L. Hanisch B. Hartmann E. Hartung K. G. Hering G. Heuchert M. Jäger J. Krämer Dr. A. Kranig E. Ludolph A. Luttmann A. Nienhaus W. Pieper K.-D. Pöhl T. Remé D. Riede G. Rompe K. Schäfer S. Schilling E. Schmitt F. Schröter A. Seidler M. Spallek M. Weber 《Trauma und Berufskrankheit》2005,7(3):211-252
Occupational diseases Nos. 2108 and 2110 correspond to intervertebral disc-related diseases of the lumbar spine from many years of carrying or lifting heavy loads, occupations in extreme postures of full flexion or oscillation of the whole body when seated, and which compel the cessation of all activities which are or could be the cause for the origin, exacerbation or recurrence of the disease. These occupational diseases came into force at the start of 1993, but there have been considerable problems in their implementation. The present Part I of the contribution is the result of the work of an interdisciplinary study group and contains medical criteria for the assessment of possibly strain-related clinical characteristics and the evaluation of other possible causes. Part II is to be published in Volume 4/2005 and will deal with questions related to forced cessation and to the assessment of the loss of earning ability. Agreement was reached in many areas related to the assessment of occupational claims. This should allow for evidence-based decision making in the future for the occupational diseases Nos. 2108 and 2110. 相似文献
8.
Dr. Erich Traub 《European journal of pediatrics》1937,58(6):769-789
Zusammenfassung Die Auffassung des akuten Gelenksrheumatismus als allergische Krankheit bedingt auch die Deutung der diese Erkrankung begleitenden Hauterscheinungen als allergische Phänomene. Das Erythema annulare und die Urticaria rheumatica werden im Sinne toxisch-allergischer Effloreszenzen erklärt, und der Rheumatismus nodosus diesen beiden Hautveränderungen als periphere hyperergische Entzündung bei einer bestimmten Reaktionslage des sensibilisierten Organismus symptomatologisch und prognostisch nahegestellt. An Hand mehrerer Fälle werden Beobachtungen gebracht, daß die erwähnten peripheren Erscheinungen klinisch ähnliches Geschehen begleiten und somit ihre engere innere Verwandtschaft als wahrscheinlich angenommen. Erythema annulare, Urticaria rheumatica und Rheumatismus nodosus begleiten eine Generalisation der rheumatischen Infektion und treten meist dann auf, wenn die Herzklappen, das Nervensystem oder die serösen Häute ergriffen werden. Alle drei Phänomene haben auch gemeinsame Beziehungen zu Allergieschwankungen im Organismus. In diesem Sinne werden die erwähnten Erscheinungen als Symptome eines allergischen Sekundärstadiums der akuten Polyarthritis aufgefaßt (ähnlich den sekundären Hauteffloreszenzen bei der Tuberkulose) und ihnen als Indikatoren der Generalisation der rheumatischen Noxe, besondere prognostische Bedeutung zugemessen. 相似文献
9.
10.
Priv.-Doz. Dr. Rüdiger Dissmann Joachim Schröder MD PhD Prof. Dr. med. Heinz Völler Prof. Dr. med. Steffen Behrens 《Clinical research in cardiology》2006,95(4):241-243
Summary During pacemaker implantation in a patient with permanent atrial fibrillation, it remained impossible to advance a passive
fixation lead with fins through the right atrium. However, a lead with a retractable screw easily passed the right atrium
and was positioned in the right ventricle. Transesophageal echocardiography revealed an extensive net–like perforated Eustachian
valve within the right atrium that had caused entrapment of the anchor fins during lead implantation. Remnants of embryonal
structures within the right atrium should be considered a rare possible barrier during pacemaker implantation. 相似文献