全文获取类型
收费全文 | 12117篇 |
免费 | 731篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 358篇 |
妇产科学 | 278篇 |
基础医学 | 1538篇 |
口腔科学 | 271篇 |
临床医学 | 874篇 |
内科学 | 2901篇 |
皮肤病学 | 292篇 |
神经病学 | 1077篇 |
特种医学 | 334篇 |
外科学 | 1772篇 |
综合类 | 70篇 |
一般理论 | 1篇 |
预防医学 | 984篇 |
眼科学 | 384篇 |
药学 | 611篇 |
中国医学 | 28篇 |
肿瘤学 | 1080篇 |
出版年
2023年 | 74篇 |
2022年 | 186篇 |
2021年 | 382篇 |
2020年 | 213篇 |
2019年 | 337篇 |
2018年 | 364篇 |
2017年 | 266篇 |
2016年 | 290篇 |
2015年 | 332篇 |
2014年 | 435篇 |
2013年 | 565篇 |
2012年 | 881篇 |
2011年 | 880篇 |
2010年 | 455篇 |
2009年 | 469篇 |
2008年 | 741篇 |
2007年 | 750篇 |
2006年 | 726篇 |
2005年 | 734篇 |
2004年 | 614篇 |
2003年 | 515篇 |
2002年 | 488篇 |
2001年 | 170篇 |
2000年 | 148篇 |
1999年 | 148篇 |
1998年 | 98篇 |
1997年 | 86篇 |
1996年 | 87篇 |
1995年 | 69篇 |
1994年 | 55篇 |
1993年 | 48篇 |
1992年 | 146篇 |
1991年 | 124篇 |
1990年 | 121篇 |
1989年 | 114篇 |
1988年 | 96篇 |
1987年 | 72篇 |
1986年 | 78篇 |
1985年 | 61篇 |
1984年 | 51篇 |
1983年 | 53篇 |
1982年 | 37篇 |
1981年 | 20篇 |
1979年 | 37篇 |
1978年 | 30篇 |
1977年 | 26篇 |
1974年 | 23篇 |
1972年 | 18篇 |
1971年 | 18篇 |
1969年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Adriano Chiò Elena Herrero Hernandez Gabriele Mora Consuelo Valentini Gianluigi Discalzi Enrico Pira 《Amyotrophic lateral sclerosis and other motor neuron disorders》2004,5(3):188-191
A 34-years-old floor-layer developed optic neuropathy and motor neuron disease after being accidentally exposed to a solvent mixture containing methanol and other substances. Optic neuropathy is a complication of methanol poisoning, but the onset of a motor neuron disorder resembling amyotrophic lateral sclerosis after the exposure to these substances has not been previously described. The temporal onset of the clinical symptoms, biological plausibility, young age of the patient and absence of neurological disorders in the family history raises suspicion of a possible causative relationship. 相似文献
12.
Alfredo Avellaneda Fernández álvaro Pérez Martín Maravillas Izquierdo Martínez Mar Arruti Bustillo Francisco Javier Barbado Hernández Javier de la Cruz Labrado Rafael Díaz-Delgado Pe?as Eduardo Gutiérrez Rivas Cecilia Palacín Delgado José Ramón Ramón Giménez Javier Rivera Redondo 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2009,41(10):e1-e5
13.
J L Encinas A Luis L F Avila F Hernandez J Sarria M Gamez J Murcia L Leal M Lopez-Santamaria J A Tovar 《Zeitschrift für Kinderchirurgie》2006,16(6):403-406
INTRODUCTION: The management of children receiving small bowel grafts involves potentially life-threatening complications that affect their nutritional status. The aim of this paper was to define these factors and their influence on nutritional outcome. PATIENTS AND METHODS: Patients with intestinal failure (IF) who received an isolated small bowel transplantation (SBT) or small bowel/liver transplantation (SBLT) at our hospital during the last 6 years were reviewed for weight Z-score, biochemical nutritional parameters, total parenteral nutrition (TPN) weaning, catheter-related sepsis, rejection and steroid treatment. RESULTS: Twenty patients, 11 females and 9 males, received a SBT or a SBLT and survived the postoperative period; in the present study we only included 11 children with follow-up periods longer than 1 year. Seven males and 4 females with a mean age of 4.5 years (range, 1 to 20 years) received 6 SBLT and 5 SBT. Nine (82%) were weaned from TPN to an amino-acid or peptide enteral formula during the first 6 months after surgery. During the first year there was a significant increase in total protein from 5.11 +/- 1.8 mg/dl to 6.1 +/- 1.5 mg/dl (p < 0.05) and an increase in albumin from 3.8 +/- 0.9 mg/dl to 4.5 +/- 1.1 mg/dl (p < 0.05). There was an increase in weight Z-score in 9 patients (82%) during the first year. Mean Z-score improved from - 2.6 +/- 1 at transplant to - 1.0 +/- 0.6 (p < 0.05) after 1 year. Three patients (27.2%) had at least one rejection period, which was treated with steroids alone or in combination. Mean weight Z-score 1 year after surgery was - 0.9 +/- 0.6 for patients without rejection and - 1.24 +/- 0.8 for those with at least one rejection episode treated with steroids (p > 0.1). Four patients (36%) had at least one catheter-related sepsis episode. Mean weight Z-score 1 year after surgery was - 1.01 +/- 0.6 for patients without catheter-related sepsis and - 1.24 +/- 0.8 for those with at least one catheter-related sepsis episode (p > 0.1). CONCLUSIONS: There was a significant improvement in weight Z-score and biochemical nutritional parameters 1 year after receiving a small bowel graft. No influence of steroids or catheter-related sepsis on children's nutritional status was noted 1 year after surgery, although this point will need further evaluation. 相似文献
14.
J. Román Corona-Rivera Alfredo Corona-Rivera Sylvia E. Totsuka-Sutto Enrique Corona-Rivera 《Clinical genetics》1997,51(4):257-259
Gluteal and lower extremity hypoplasia with ipsilateral toe brachysyndactyly were noted in a 23-year-old woman similarly affected to the only previously reported case of the lower extremity counterpart of Poland sequence. Since no neurological deficit was found, and electromyographic and nerve conduction studies in the affected limb were normal, we propose a vascular origin which would involve the external iliac artery supply analogous to the subclavian artery supply disruption in the upper extremity Poland sequence. 相似文献
15.
The role of glutamate in conditioned taste aversion was investigated. Both, in the amygdala (AMYG) and in the lateral hypothalamus (LH) extracellular levels of glutamate were assessed by microdialysis and capillary electrophoresis with laser induced fluorescence detection. Rats were conditioned by pairing a novel flavor (strawberry flavor) with an intraperitoneal injection of lithium chloride. When the conditioned stimulus (strawberry flavored solution) was injected into the mouth of conditioned rats, there was an increase of glutamate release in the AMYG, and a decrease in glutamate release in the LH. These results predicted that glutamate release in the AMYG and the LH was involved in CTA. This possibility was tested by MK-801 (glutamate antagonist) and glutamate microinjections. MK-801 injections in AMYG attenuated the rejection of the novel flavor, and in the LH did not cause any effect on CTA. Glutamate microinjections in the AMYG caused CTA. These results suggest that glutamatergic activity in the AMYG might be a relevant neurochemical correlate and cause of conditioned taste aversion. 相似文献
16.
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
17.
F Martínez Soriano T Hernandez Gil de Tejada C Cimas Garcia E Arma?anzas 《Journal für Hirnforschung》1992,33(3):271-275
A comparative statistical analysis of "synaptic ribbons" evolution over a 24 hour period during two different photoluminous seasons (September, and winter) is carried out. Seventy male rats were used. Statistical analysis involved the Kolmogorov-Smirnov test, variance analysis, the Student t-test and Pearson's correlation test. The results show that "synaptic ribbons" evolve during the circadian phase and through two different seasons, with a clear and marked influence of point-time (p < 0.0001) and season (p < 0.0001). 相似文献
18.
The goal of IMRT is to achieve an isodose distribution conformed to the tumor while avoiding the organs at risk. For these tasks several gantry angles are selected, each one containing a series of different leaf configurations for the multileaf collimator (MLC) (segments). Verifying the relative distributions as well as the absolute doses is an important step for quality assurance issues. We have observed that an accurate modeling of the transmission of the primary x-ray fluence through the jaws and MLC as well as the head scatter is crucial for a precise calculation of relative doses and monitor units. Also, an inaccurate calculation of the output factor for small size segments can lead to important differences in the absolute dose for points under these segments. Incorrect models could lead to systematic errors of around 5% to 10% in the calculated monitor units and a shift in the isodose curves. 相似文献
19.
Laska M Fendt M Wieser A Endres T Hernandez Salazar LT Apfelbach R 《Physiology & behavior》2005,84(2):211-215
2,4,5-trimethylthiazoline (TMT) is a volatile component of the anal gland secretion of the red fox and elicits behavioral and physiological fear responses in the rat. Using instrumental conditioning paradigms, we determined olfactory detection thresholds for TMT in three rats, a natural prey species of the red fox, and compared their performance to that of three squirrel monkeys, three spider monkeys and four pigtail macaques, all non-prey species of the red fox. We found that the rats were able to discriminate concentrations between 0.04 and 0.10 ppt (parts per trillion) of TMT from the odorless solvent which is by far the lowest olfactory detection threshold for an odorant reported in rats so far. In contrast, the spider monkeys needed 0.14-1.38 ppb (parts per billion), the pigtail macaques 0.41-4.07 ppb, and the squirrel monkeys 4.07-13.80 ppb to detect TMT which does not rank among the lowest olfactory thresholds reported for these three primate species. Thus, these results support the assumption that the behavioral relevance of an odorant may be an important determinant of a species' olfactory sensitivity. 相似文献
20.
Severe, late-onset graft-versus-host disease in a liver transplant recipient documented by chimerism analysis 总被引:4,自引:0,他引:4
Pollack MS Speeg KV Callander NS Freytes CO Espinoza AA Esterl RM Abrahamian GA Washburn WK Halff GA 《Human immunology》2005,66(1):28-31
A 52-year-old liver transplant recipient presented 8 months after transplantation with oral thrush, then 3 days later with oral ulcers and a diffuse rash, and 5 days later with an acutely reduced white blood cell count, rash, fever, and diarrhea. Bone marrow biopsy revealed severe aplasia. Although graft-versus-host disease (GVHD) was considered, the late onset of these symptoms was felt to render this etiology unlikely because GVHD usually occurs 2 to 6 weeks after transplantation. All potentially myelosuppressive medications were discontinued, and the patient was treated with high doses of hematopoietic growth factors. Because his symptoms continued, chimerism analysis was performed, which indicated that 96% of the peripheral blood mononuclear cells were of liver-donor origin. Ultimately, the patient underwent an allogeneic peripheral blood hematopoietic progenitor cell transplant from a human leukocyte antigen-identical brother, but he died 5 days after transplantation of overwhelming Candida kruseii infection. To our knowledge, this is the first chimerism-analysis-documented case of severe acute GVHD presenting so late after liver transplantation. It is of note that the patient had no known risks for GVHD in that he was relatively young and shared only one major human leukocyte antigen with his donor. Consideration should be given to GVHD as a cause of bone marrow aplasia at any time after organ transplantation. Storage of cell pellets from all transplant recipients and donors is highly recommended to facilitate the diagnostic evaluation. 相似文献