全文获取类型
收费全文 | 45294篇 |
免费 | 2116篇 |
国内免费 | 373篇 |
专业分类
耳鼻咽喉 | 469篇 |
儿科学 | 842篇 |
妇产科学 | 1317篇 |
基础医学 | 5370篇 |
口腔科学 | 1710篇 |
临床医学 | 3480篇 |
内科学 | 12694篇 |
皮肤病学 | 925篇 |
神经病学 | 3942篇 |
特种医学 | 1193篇 |
外科学 | 6864篇 |
综合类 | 170篇 |
一般理论 | 9篇 |
预防医学 | 2469篇 |
眼科学 | 716篇 |
药学 | 2444篇 |
中国医学 | 114篇 |
肿瘤学 | 3055篇 |
出版年
2024年 | 40篇 |
2023年 | 325篇 |
2022年 | 782篇 |
2021年 | 1471篇 |
2020年 | 789篇 |
2019年 | 1121篇 |
2018年 | 1551篇 |
2017年 | 1018篇 |
2016年 | 1111篇 |
2015年 | 1307篇 |
2014年 | 1798篇 |
2013年 | 2359篇 |
2012年 | 3625篇 |
2011年 | 3574篇 |
2010年 | 2017篇 |
2009年 | 1754篇 |
2008年 | 3055篇 |
2007年 | 3159篇 |
2006年 | 2953篇 |
2005年 | 2920篇 |
2004年 | 2637篇 |
2003年 | 2359篇 |
2002年 | 2085篇 |
2001年 | 291篇 |
2000年 | 199篇 |
1999年 | 303篇 |
1998年 | 371篇 |
1997年 | 323篇 |
1996年 | 284篇 |
1995年 | 280篇 |
1994年 | 223篇 |
1993年 | 168篇 |
1992年 | 149篇 |
1991年 | 114篇 |
1990年 | 116篇 |
1989年 | 93篇 |
1988年 | 68篇 |
1987年 | 69篇 |
1986年 | 78篇 |
1985年 | 75篇 |
1984年 | 75篇 |
1983年 | 66篇 |
1982年 | 95篇 |
1981年 | 66篇 |
1980年 | 71篇 |
1979年 | 40篇 |
1978年 | 51篇 |
1977年 | 38篇 |
1976年 | 36篇 |
1974年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Alfonso Fasano Antonio E Elia Arianna Guidubaldi Pietro A Tonali Anna Rita Bentivoglio 《Movement disorders》2007,22(4):564-566
We report a case of cervical dystonia occurring in a 33-year-old without personal history of movement disorder but with family history of essential tremor, primigravid, primiparous woman at 1 weeks' amenorrhea, resolved completely after delivery in the course of 3 months. Dystonia never recurred in the following 5 years. Several neurological disorders are known to occur or worsen during pregnancy. As far as we know, this is the second reported case of dystonia occurring during pregnancy, thus confirming that dystonia gravidarum represents a new entity and should be considered in women of reproductive age affected by dystonia, especially when presenting with rapid-onset cervical dystonia. 相似文献
22.
Paolo Mariotti Alfonso Fasano M Fiorella Contarino Giacomo Della Marca Marco Piastra Orazio Genovese Silvia Pulitanò Antonio Chiaretti Anna Rita Bentivoglio 《Movement disorders》2007,22(7):963-968
Status dystonicus (SD) is a life threatening disorder that develops in patients with both primary and secondary dystonia, characterized by acute worsening of symptoms with generalized and severe muscle contractions. To date, no information is available on the best way to treat this disorder. We review the previously described cases of SD and two new cases are reported, one of which occurring in a child with static encephalopathy, and the other one in a patient with pantothenate kinase-associated neurodegeneration. Both patients were admitted to an intensive care unit and treated with midazolam and propofol. This approach proved to be useful in the former while the progressive nature of the dystonia of the second patient required the combination of intrathecal baclofen infusion and bilateral pallidal deep brain stimulation. We believe that a rapid and aggressive approach is justified to avoid the great morbidity and mortality which characterize SD. Our experience, combined with the data available in the literature, might permit to establish the best strategies in managing this rare and severe condition. 相似文献
23.
24.
25.
Giuseppe Montalto Leonardo Ficano Antonio Carroccio Francesco D''arpa Luigi Greco Maurizio Soresi Pasquale Salvo 《Journal of Hepato-Biliary-Pancreatic Surgery》1994,1(5):573-577
The clinical and biochemical presentation of carcinoma of the pancreas (PC) and of the papilla of Vater (CPV) are very similar, and, consequently, detailed investigations are required to correctly distinguish between them. The aim of the present study was to select the clinical and biochemical variables that would most efficiently discriminate the precise site of tumor origin. The study group consisted of 72 patients with PC and 22 patients with CPV consecutively hospitalized in our department. The following clinical parameters were considered: age, asthenia, anorexia, vomiting, weight loss, pain, fever, pruritis, and constipation; the biochemical parameters considered were total, direct, and indirect bilirubin, glucose, alkaline phosphatase, gamma glutamy transferase, transaminase, total protein, amylase, and occult blood in stools. The results indicated that in the initial phase of PC the most frequent clinical parameters were weight loss (P<0.0001), anorexia (P<0.02), constipation (P<0.001), and pruritus (P<0.01). In contrast, in CPV, fever (P<0.003) was most frequent in the same phase. There was a statistically significant difference in occult blood in stools (P<0.0001), total (P<0.03) and direct bilirubin (P<0.02), alkaline phosphatase (P<0.05), and transaminase (P<0.002) values in the two groups. On discriminant analysis, weight loss, constipation, pruritus, nausea, anorexia, and fever were the variables which best discriminated between the two types of tumors. In fact, the presence of weight loss, anorexia, asthenia, constipation, and pruritus correctly classified 87.5% of the patients with PC, while the presence of fever and nausea correctly classified 72.7% of the patients with CPV. 相似文献
26.
María de Gracia García-Martín María Violante de Paz Juan Antonio Galbis 《Macromolecular chemistry and physics.》1997,198(1):219-227
A chiral poly(3-substituted isobutyl D -aspartate) 12 was synthesized by polymerization of the chiral β-lactam 11 derived from D -glyceraldehyde. The new polyamide was characterized by elemental analyses, and infrared, 1H- and 13C nuclear magnetic resonance spectroscopies. The molecular weight was estimated as 543 000 and 230 000 on the basis of viscosimetric measurements and gel-permeation chromatography, respectively. Polyamide 12 is soluble in a variety of organic solvents including chloroform. 相似文献
27.
Do weekly and fast-rotating shiftwork schedules differentially affect duration and quality of sleep?
F. M. Fischer Antonio Castro Bruni Adelaide Berwerth Claudia Roberta Castro Moreno Rosaneli Lima Fernandez Claudia Riviello 《International archives of occupational and environmental health》1997,69(5):354-360
Characteristics of shiftwork schedules can have distinct impacts on workers’ sleep. This report presents comparisons of the
effects of two different shiftwork schedules on duration and quality of the main sleep episodes in comparable worker populations
at two different petrochemical plants. No significant differences were found for sleep duration in comparing the two plants.
However, within each plant’s shift cycles, morning and night shifts showed shorter sleep durations than all other workdays
and days off. Quality of sleep was perceived as lowest for night shifts of both plant schedules, and of lesser quality for
weekly than for fast-rotating shifts. These results support recommendations for reducing the number of consecutive nights
of shiftwork. However, before recommending any optimal shift schedule, interactions of sleep duration and quality with shift
schedules need much further evaluation.
Received: 18 December 1995/Accepted: 18 July 1996 相似文献
28.
Luciano Baresi Fabrizio Consorti Manuele Di Paola Antonio Gargiulo Mauro Pezzè 《Journal of medical systems》1997,21(6):369-388
The quality of health care systems and processes is becoming a prominent problem and more and more efforts are devoted to define methodologies and tools to measure and assure quality of care. New methods are required to optimize health care processes to guarantee high quality standards within (limited) available resources. Resource optimizations able to preserve the quality of treatments require good models of medical processes. This paper presents LEMMA, a new notation to model medical processes. LEMMA provides physicians with intuitive graphical elements to design their models. At the same time a high level timed Petri net corresponding to the designed model is built automatically. In this way, LEMMA models are ascribed formal semantics and can be executed and analyzed automatically. The dual language approach followed in this paper allows physicians to gain all the benefits of formal methods without being proficient in them. Medical users manage simple graphical elements, while Petri nets ensure formality and validation capabilities. In this way LEMMA mixes formal and informal notations, overcoming the problems of both the approaches. The definition of the notation has been supported by the development of an environment to design LEMMA models. The environment, besides letting us experiment with the notation, has been employed to define and analyze real case studies. 相似文献
29.
Periodic lateralized epileptiform discharges: etiology, clinical aspects, seizures, and evolution in 130 patients. 总被引:4,自引:0,他引:4
Irene García-Morales M Teresa García Lucia Galán-Dávila Carlos Gómez-Escalonilla Rosana Saiz-Díaz Antonio Martínez-Salio Pilar de la Pe?a Julian A Tejerina 《Journal of clinical neurophysiology》2002,19(2):172-177
The purpose of this study was to analyze the clinical aspects in 130 patients presenting periodic lateralized epileptiform discharges (PLEDs) in their EEG and to compare these results with those found in the literature. Etiology, neurologic deficit, seizure occurrence, and evolution were studied in each patient by historical review. The recordings were obtained on 8- or 16-channel EEGs with electrode placement according to the International 10-20 System. Recordings containing PLEDs were selected. PLEDs were defined as repetitive periodic, focal, or hemispheric epileptiform discharges (spikes, spike and waves, polyspikes, sharp waves) usually recurring every 1 to 2 seconds. The statistical study was carried out via the chi(2) test using the computer program SPSS. The main etiology found in this group of patients was stroke (61 of 130 patients). Other processes found were brain infections, tumors, hematomas, and several other entities grouped together as miscellaneous (anoxic encephalopathy, subarachnoid hemorrhage, craniocerebral trauma, Creutzfeldt-Jacob disease, migraine, multiple sclerosis, and aminophylline intoxication). Half of these patients (65 of 130) developed seizures, mostly partial motor seizures. No significant relation between etiology and seizures was found (chi(2) = 2.81, P = 0.4222). Seizures recurred in 14 of 130 patients during a follow-up of 14.5 months. PLEDs were not recorded in any EEG at the time of seizure recurrence. PLEDs constitute a distinctive but uncommon EEG phenomenon of repetitive, periodic, and stereotyped lateralized complexes. In agreement with the literature, PLEDs were associated with an acute process and occurred early during the course of the illness in all patients studied and were usually associated with structural lesions, with stroke being the main etiology. Traditionally, seizures occur with PLEDs but it is also accepted that they can exist in patients who never develop epileptic activity, either clinically or electrically, as demonstrated in 50% of the patients studied. No significant association between seizures and any etiology could be found. It was not demonstrated that the occurrence of seizures may influence the outcome in any way. 相似文献
30.