全文获取类型
收费全文 | 54149篇 |
免费 | 3588篇 |
国内免费 | 262篇 |
专业分类
耳鼻咽喉 | 522篇 |
儿科学 | 1925篇 |
妇产科学 | 1371篇 |
基础医学 | 8070篇 |
口腔科学 | 791篇 |
临床医学 | 5205篇 |
内科学 | 12293篇 |
皮肤病学 | 1177篇 |
神经病学 | 5906篇 |
特种医学 | 1126篇 |
外科学 | 4435篇 |
综合类 | 297篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 5057篇 |
眼科学 | 948篇 |
药学 | 4078篇 |
中国医学 | 136篇 |
肿瘤学 | 4618篇 |
出版年
2024年 | 91篇 |
2023年 | 684篇 |
2022年 | 1442篇 |
2021年 | 2434篇 |
2020年 | 1406篇 |
2019年 | 1800篇 |
2018年 | 1969篇 |
2017年 | 1595篇 |
2016年 | 1752篇 |
2015年 | 1910篇 |
2014年 | 2479篇 |
2013年 | 3108篇 |
2012年 | 4586篇 |
2011年 | 4592篇 |
2010年 | 2435篇 |
2009年 | 2075篇 |
2008年 | 3479篇 |
2007年 | 3464篇 |
2006年 | 3131篇 |
2005年 | 2854篇 |
2004年 | 2646篇 |
2003年 | 2365篇 |
2002年 | 2130篇 |
2001年 | 258篇 |
2000年 | 203篇 |
1999年 | 269篇 |
1998年 | 336篇 |
1997年 | 289篇 |
1996年 | 198篇 |
1995年 | 185篇 |
1994年 | 187篇 |
1993年 | 143篇 |
1992年 | 110篇 |
1991年 | 96篇 |
1990年 | 75篇 |
1989年 | 86篇 |
1988年 | 78篇 |
1987年 | 73篇 |
1986年 | 61篇 |
1985年 | 63篇 |
1984年 | 83篇 |
1983年 | 69篇 |
1982年 | 79篇 |
1981年 | 67篇 |
1980年 | 61篇 |
1979年 | 30篇 |
1978年 | 34篇 |
1977年 | 35篇 |
1976年 | 25篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Janina Rafalowska Anna Fidzianska Dorota Dziewulska Aleksandra Podlecka Grazyna Maria Szpak Hubert Kwiecinski 《Neuropathology》2004,24(1):16-20
In the present study, morphological examination of patients from two unrelated Polish families with CADASIL was performed. Using light microscopy, there were evident changes characteristic to the disease. On electron microscopy, deposits of granular osmiophillic material (GOM) were found not only in cerebral arteries and veins but also in cerebral capillaries and vessels of the internal organs. These findings indicate that pathological process in CADASIL is generalized and involves also small vessels devoid of smooth muscle cells. Therefore, we propose to consider a replacement for the name CADASIL that better reflects the morphological picture of the disease like, for example, cerebral autosomal dominant vasculopathy with subcortical infarcts and leukoencephalopathy (CADVaSIL) or, to preserve the commonly known acronym, cerebral autosomal dominant angiopathy with subcortical infarcts and leukoencephalopathy. 相似文献
102.
PURPOSE: Although the angle of deviation in patients with congenital esotropia has been shown to increase during the early preoperative period, few data exist regarding this change in other forms of childhood esotropia. The primary objective of this study was to investigate whether the angle of deviation increases with time in patients with acquired nonaccommodative esotropia (ANAET). METHODS: The medical records of all children whose ANAET was diagnosed at East Tennessee State University College of Medicine from August 1, 1995, through October 1, 2001, were retrospectively reviewed. All patients were assessed for any change in the amount of their strabismic angle and associated risk factors. RESULTS: Eighty-two patients with ANAET were identified, and all except 3 underwent more than one examination. Of the 79 children who underwent more than one examination, 26 (32.9%) displayed an angle increase of > or =10 prism diopters (PD) during a median follow-up period of 2.9 months. The ANAET of those patients whose angle increased by > or =10 PD was diagnosed (28.4 months of age vs 45.5 months of age, P =.003), and they underwent surgery (35.9 months of age vs 53.3 months of age, P =.003) at a significantly younger median age than those whose angle increased <10 PD. CONCLUSIONS: The angle of deviation of approximately one third of patients with ANAET in this study increased at least 10 PD in the early preoperative period. This increase occurs more often in younger patients and underscores the importance of performing serial measurements of the deviating angle before surgical intervention is undertaken. 相似文献
103.
104.
Anna Szymańska Elżbieta Korobowicz Wiesław Gołąbek 《European archives of oto-rhino-laryngology》2006,263(7):657-660
Nasopharyngeal angiofibromas occur predominantly in males in their puberty and adolescence; the incidence in other age groups and in women is exceptional. This report describes a case of a 57-year-old woman with nasopharyngeal angiofibroma presenting typical radiological findings in computed tomography, MR imaging and angiography. The tumour was successfully removed and histopathological examination confirmed the diagnosis. In 6 years follow-up the patient is free of symptoms. 相似文献
105.
Felice Cardillo Piccolino Giovanni Calabria Anna Polizzi Mauro Fioretto 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1989,227(4):335-339
Two young brothers were bilaterally affected by pigmentary glaucoma and extensive symmetrical changes of the retinal pigment epithelium (RPE). Fundus changes consisted in widespread salt-and-pepper RPE mottling and pigment clumping, sparing only the peripapillary and foveal areas. During the course of 4 years, one of the two patients suffered multiple, recurrent, exudative and hemorrhagic detachments of the RPE that involved the midperiphery and posterior pole. No exudative lesions appeared in the brother. The medical history and systemic laboratory tests were noncontributory in both patients. The ERG was normal and the EOG subnormal. Dark adaptation was delayed and showed an elevation of the scotopic threshold. These cases seem to support the hypothesis that the RPE is also involved in the pigmentary dispersion syndrome. An inherited defect could affect the pigment epithelium in both the anterior and posterior segments of the eye. The multifocal subretinal exudative pattern that occurred in one of our patients has not been previously observed in hereditary disorders of the RPE.Presented at the XVIth Meeting of the Club Jules Gonin, Bruges, 4–8 September 1988 相似文献
106.
Josep Oriola Cristina Hernandez Rafael Simo Anna Barceló Roser Casamitjana Enric Vilardell & Francisca Rivera-Fillat 《Clinical endocrinology》1996,44(2):207-212
OBJECTIVE Genetic analysis is now essential for the accurate screening of families with multiple endocrine neoplasia type 2 (MEN2). We present the genetic analyses by both haplotype and direct RET proto-oncogene mutation analysis in seven Mediterranean MEN 2A families and have compared these results with biochemical screening tests and pathological examinations.
DESIGN Total DNA was extracted from leucocytes. Linkage analysis was performed using five RFLP systems from three loci that flank the MEN2A locus (FNRB, RBP3, D10S15). RET proto-oncogene analysis was carried out by automatic DNA sequencing and adequate digestion of PCR amplified products for exons 10 and 11. Screening for medullary thyroid carcinoma or C-cell hyperplasia was performed by the pentagastrin provocation test. Adrenal medullary function was assessed by measurements of 24-hour urinary excretion of catecholamines and their metabolites. Serum calcium and phosphate measurements were the initial screen for hyperparathyroidism. Serum PTH was determined only if hyperparathyroidism was suggested by the former determinations.
PATIENT Genetic study was performed in 59 individuals (39 at risk) from seven kindreds of Mediterranean origin with MEN 2A.
RESULTS Diagnosis by linkage analysis was not possible in 30% of individuals at risk, but RET proto-oncogene analysis identified all these individuals. Mutations of the RET proto-oncogene were detected in exon 10 (codon 618) in one MEN 2A kindred and in exon 11 (codon 634) in the others. The results of direct analysis were concordant with linkage studies in each case. Three individuals from different MEN 2A kindreds, who were subsequently shown not to be gene carriers, had false positive pentagastrin stimulation tests.
CONCLUSION Biochemical tests can be replaced by direct DNA mutation analysis as the first line screening test in order to identify gene carriers of MEN 2A. 相似文献
DESIGN Total DNA was extracted from leucocytes. Linkage analysis was performed using five RFLP systems from three loci that flank the MEN2A locus (FNRB, RBP3, D10S15). RET proto-oncogene analysis was carried out by automatic DNA sequencing and adequate digestion of PCR amplified products for exons 10 and 11. Screening for medullary thyroid carcinoma or C-cell hyperplasia was performed by the pentagastrin provocation test. Adrenal medullary function was assessed by measurements of 24-hour urinary excretion of catecholamines and their metabolites. Serum calcium and phosphate measurements were the initial screen for hyperparathyroidism. Serum PTH was determined only if hyperparathyroidism was suggested by the former determinations.
PATIENT Genetic study was performed in 59 individuals (39 at risk) from seven kindreds of Mediterranean origin with MEN 2A.
RESULTS Diagnosis by linkage analysis was not possible in 30% of individuals at risk, but RET proto-oncogene analysis identified all these individuals. Mutations of the RET proto-oncogene were detected in exon 10 (codon 618) in one MEN 2A kindred and in exon 11 (codon 634) in the others. The results of direct analysis were concordant with linkage studies in each case. Three individuals from different MEN 2A kindreds, who were subsequently shown not to be gene carriers, had false positive pentagastrin stimulation tests.
CONCLUSION Biochemical tests can be replaced by direct DNA mutation analysis as the first line screening test in order to identify gene carriers of MEN 2A. 相似文献
107.
Anna Pizzirusso Patrizia Oliva Sabatino Maione Michele D’Amico Francesco Rossi L. Berrino 《Naunyn-Schmiedeberg's archives of pharmacology》1998,357(5):514-518
In order to evaluate the role played by vasopressin on pressor responses elicited by stimulation of the periaqueductal gray
(PAG) area by excitatory amino acids we carried out in vivo studies in genetically vasopressin deficient rats (Brattleboro).
Microinjections of l-glutamic acid (glutamate, 0.6 to 60 nmol/rat) or N-methyl-d-aspartic acid (NMDA, 0.07 to 7 nmol/rat)
into the PAG area of freely moving Brattleboro rats induced increases of arterial blood pressure values significantly lower
than those obtained in Long Evans rats (control) (glutamate in Brattleboro rats: from +2±1 mmHg to 16±3 mmHg; glutamate in
Long Evans rats: from +16±2 mmHg to +36±4 mmHg; NMDA in Brattleboro rats: from +5±2 mmHg to +34 ±8 mmHg; NMDA in Long Evans
rats: from +18±7 mmHg to 80±9 mmHg; n=5). Similarly, in anaesthetized Brattleboro rats (urethane 1.2 g/kg i.p.) pressor responses to NMDA microinjections (0.7
nmol/rat) into the PAG area were significantly lower than in Long Evans rats (controls) (+15±3 mmHg vs +24±4 mmHg). In Long
Evans rats NMDA injection also reversed blood pressure decrease induced by ganglionic blocker, hexamethonium and/or losartan
(3 mg/kg i.v.), an AT1 receptor antagonist. In Brattleboro rats, NMDA injection did not reverse blood pressure decreases induced
by hexamethonium (5 mg/kg i.v.). Moreover, hexamethonium induced blood pressure decrease was not reversed by acetylcholine
injection (137 nmol/rat) into the PAG area of anaesthetized Long Evans rats, but if injected before hexamethonium, acetylcholine
was able to increase blood pressure (+25±3 mmHg). Our results document: i) the importance of the PAG area in the control
of cardiovascular system; ii) the involvement of excitatory amino acids in the neural control of vasopressin release; iii)
the close relationship between glutamate and vasopressin in the central blood pressure regulation.
Received: 1 April 1997 / Accepted: 2 February 1998 相似文献
108.
Franco Di Filippo M.D. Anna Maria Calabrò M.D. Andrea Cavallari M.D. Sandro Carlini M.D. Giovanni Luca Buttini M.D. Francesco Moscarelli M.D. Francesco Cavaliere M.D. Loredana Piarulli M.D. Renato Cavaliere M.D. 《World journal of surgery》1988,12(3):332-339
Eighty-six patients with locally advanced, high-grade soft tissue sarcomas of the extremities were studied prospectively in order to determine the efficacy of hyperthermic perfusion (HP) or hyperthermic antiblastic perfusion (HAP) as the first step of a combined multimodality therapy.
The immediate response was evaluated in terms of tumor regression, and results confirmed the in vivo sensitivity of human sarcomas to the selective antineoplastic action of heat alone or combined with drugs (melphalan, actinomycin D, and cis-platinum). HAP has been shown to be simpler and safer than HP, and it is now currently routinely employed.
As far as the long-term cure is concerned, all the patients have been evaluated for functional results, locoregional control, and survival, according to the different treatment schedules.
The first clinical trials employed HP or HAP followed by delayed surgery alone. In 11 of 17 evaluable patients treated with HP, and in 17 of 29 treated with HAP, conservative surgery could be performed. A high incidence of locoregional relapse (24%) occurred, with low overall survival rates: 50.1% and 31.7% at 5 and 10 years after HP plus surgery, and 47.9% after HAP plus surgery at both 5 and 10 years.
The protocol was, therefore, modified to include continuous intraarterial infusion of Adriamycin® (ADR) (17 patients) or radiotherapy (9 patients) before surgery.
The results obtained thus far may be summarized as follows: (a) conservative surgery with functional limb-salvage was possible in all patients; (b) the percentage of locoregional failure decreased to approximately 12% after HAP + ADR infusion + excision, the 5- and 10-year overall survival rates both being 77.6 %, and the 5- and 10-year disease-free rates both being 57.8%; (c) no local recurrences occurred in the group treated with HAP + radiotherapy + excision with a 5-year overall survival rate of 71.5% and a 5-year disease-free rate of 50.4%.
In conclusion, the combined multimodality approaches employed appear to have improved both functional results and long-term cure, even though these must be further confirmed on a larger series of patients.
Supported by Special Project Hyperthermia from the Italian Ministry of Health. 相似文献
Resumen Ochenta y seis pacientes con sarcomas de los tejidos blandos de las extremidades, de alto grado histológico, e invasión local avanzada fueron estudiados en forma prospectiva con el objeto de determinar la eficacia de la perfusión hipertérmica (PH) o la perfusión hipertérmica antiblástica (PHA) como primer paso dentro de una terapia combinada multimodal.La respuesta inmediata fue valorada en términos de la regresión tumoral, y los resultados confirmaron la sensibilidad in vivo de los sarcomas humanos a la acción antineoplásica selectiva del calor sólo o combinado con drogas (melfalán, actinomicina D, y cis-platino). La PHA ha demostrado ser más sencilla y más segura que la PH y actualmente es utilizada en forma rutinaria.En lo referente a curación a largo plazo, todos los pacientes han sido evaluados en cuanto a resultados funcionales, control locorregional, y supervivencia, de acuerdo a los diferentes programas terapéuticos.En los primeros ensayos clínicos se utilizó PH o PHA seguida de cirugía solamente. En 11 de 17 pacientes valorables tratados con PH y 17 con PHA, fue posible realizar cirugía conservadora. Se presentó una incidencia alta de relapso locorregional (24%), con tasas bajas de supervivencia global: 50.1% y 31.7% a 5 y 10 años con PH y cirugía, y 47.9% con PHA y cirugía tanto a 5 como a 10 años.El protocolo fue consecuentemente modificado para incluir una infusión intraarterial continua de Adriamicina® (ADR) (17 pacientes) o radioterapia (9 pacientes) antes de la cirugía.Los resultados logrados hasta el momento pueden ser resumidos así: (a) la cirugía conservadora con salvamento del miembro fue posible en la totalidad de los pacientes; (b) el porcentaje de falla locorregional disminuyó aproximadamente 12% después de PHA + infusión de ADR + resección, con supervivencias globales a 5 y 10 años de 77.6%, y tasas de estado libre de enfermedad a 5 y 10 años de 57.8%; (c) no se presentaron recurrencias locales en el grupo tratado con PHA + radioterapia + resección, con una tasa de supervivencia global a 5 años de 71.5% y una tasa de estado libre de enfermedad a 5 años de 50.4%.En conclusión, los aproches con terapia combinada multimodal empleados parecen haber mejorado tanto los resultados funcionales como las tasas de curación a largo plazo, aunque estos resultados aún deben ser reconfirmados en una serie mayor de pacientes.
Résumé Une étude prospective concernant 86 malades qui présentaient un sarcome des parties molles des membres de stade évolutif avancé a été entreprise pour déterminer l'efficacité de la perfusion hyperthermique ou de la perfusion hyperthermique antiblastique en tant que première étape d'un traitement à modalités multiples.La réponse immédiate a été appréciée en fonction de la régression tumorale. Les résultats ont confirmé la sensibilité in vivo des sarcomes humains à l'action antinéoplasique sélective de la chaleur employée isolemment ou combinée avec des drogues (melphalan, actinomycine D, et cis-platinum). La perfusion hyperthermique antiblastique s'est montrée plus simple et plus sûre que la perfusion hyperthermique, et de ce fait est devenue une méthode thérapeutique normalement employée.Pour apprécier l'action thérapeutique à long terme tous les malades ont été étudiés en tenant compte des résultats fonctionnels, du contrôle loco-régional, et de la survie obtenus selon les différentes thérapeutiques appliquées.Les premiers essais ont eu recours à l'hyperthermie thermique ou à l'hyperthermie thermique antiblastique suivie d'une intervention chirurgicale. Chez 11 des 17 malades traités par l'hyperthermie thermique, et chez 17 des 29 malades soumis à l'hyperthermie antiblastique le traitement chirurgical conservateur a pu être réalisé. Les résultats furent les suivants: fréquence importante des récidives loco-régionales (24%); taux global de survie bas: 50.1% et 31.7% à 5 ans et 10 ans après perfusion hyperthermique suivie de chirurgie, ce taux étant de 47.9% après perfusion hyperthermique antiblastique suivie de chirurgie à 5 ans et 10 ans.En fonction de ces résultats le protocole thérapeutique fut modifié en y ajoutant une transfusion intra-artérielle continue d'Adriamycine® (17 malades) ou de la radiothérapie (9 malades) avant l'intervention.Les résultats obtenus à ce jour peuvent se résumer ainsi: (a) la chirurgie conservatrice permettant de sauver un membre fonctionnel est toujours possible; (b) la poucentage d'échec régional décroit environ jusqu' à 12% après perfusion hyperthermique antiblastique associée à la perfusion d'Adriamycine® et l'excision, le taux global de survie à 5 ans et 10 ans étant de 77.6%, le taux d'absence de la maladie à 5 ans et 10 ans étant de 57.8%; (c) aucune récidive locale n'est survenue dans le groupe traité par perfusion hyperthermique antiblastique associé à la radiothérapie et à l'exérèse, le taux global de survie à 5 ans étant de 71.5% et le taux d'absence de la maladie à 5 ans étant de 50.4%.En conclusion le traitement qui a été employé associant plusieurs modalités thérapeutiques a entrainé une amélioration des résultats fonctionnels et de la cure à long terme encore que ce fait demande a été confirmé par une étude étendue à un plus grand mombre de malades.
Supported by Special Project Hyperthermia from the Italian Ministry of Health. 相似文献
109.
Prevalence of hereditary ataxias and spastic paraplegias in Molise,a region of Italy 总被引:8,自引:0,他引:8
Alessandro Filla Giuseppe De Michele Roberto Marconi Luigi Bucci Carmine Carillo Anna Elisa Castellano Lucio Iorio Claudio Kniahynicki Francesco Rossi Giuseppe Campanella 《Journal of neurology》1992,239(6):351-353
Summary An epidemiological survey of hereditary ataxias and paraplegias was conducted in Molise, a region of Italy (335, 211 inhabitants on 1 January 1989). Total prevalence was 7.5 x 10–5 inhabitants (95% confidence limits 4.8–11.1). There were 7 patients with Friedreich's disease, 5 with early onset cerebellar ataxia with retained tendon reflexes, 4 with ataxia-telangiectasia, 9 with hereditary spastic paraplegias (2 autosomal dominant and 7 autosomal recessive cases). There was no patient with autosomal dominant cerebellar ataxia. 相似文献
110.
F Laffitte J P Chavoin P Guedj D Rouge M Costagliola 《Annales de chirurgie plastique et esthétique》1989,34(5):433-437
The authors present their experience of the use of carbon dioxide laser for the treatment of angiodysplasias (so-called "cavernous" angiomas). The reduction of operative haemorrhage and the simpler postoperative course resulting from the intraoperative and postoperative use of this technique have ensured very satisfactory results in a series of 76 patients. The limitations of the technique are defined. The authors also discuss the complex classification of "cavernous angiomas" and propose a synthetic clinical approach by combining the embryological, histological, evolutive and radiographic features of these lesions. 相似文献