全文获取类型
收费全文 | 5440篇 |
免费 | 392篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 214篇 |
妇产科学 | 170篇 |
基础医学 | 676篇 |
口腔科学 | 74篇 |
临床医学 | 824篇 |
内科学 | 958篇 |
皮肤病学 | 138篇 |
神经病学 | 463篇 |
特种医学 | 123篇 |
外科学 | 594篇 |
综合类 | 37篇 |
一般理论 | 5篇 |
预防医学 | 522篇 |
眼科学 | 156篇 |
药学 | 398篇 |
1篇 | |
中国医学 | 23篇 |
肿瘤学 | 405篇 |
出版年
2024年 | 15篇 |
2023年 | 74篇 |
2022年 | 100篇 |
2021年 | 213篇 |
2020年 | 126篇 |
2019年 | 186篇 |
2018年 | 225篇 |
2017年 | 156篇 |
2016年 | 173篇 |
2015年 | 167篇 |
2014年 | 200篇 |
2013年 | 297篇 |
2012年 | 422篇 |
2011年 | 476篇 |
2010年 | 217篇 |
2009年 | 251篇 |
2008年 | 365篇 |
2007年 | 422篇 |
2006年 | 331篇 |
2005年 | 336篇 |
2004年 | 264篇 |
2003年 | 272篇 |
2002年 | 223篇 |
2001年 | 36篇 |
2000年 | 21篇 |
1999年 | 32篇 |
1998年 | 35篇 |
1997年 | 22篇 |
1996年 | 23篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 23篇 |
1988年 | 6篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有5841条查询结果,搜索用时 15 毫秒
11.
12.
Monica J. Carson Tina V. Bilousova Shweta S. Puntambekar Benoit Melchior Jonathan M. Doose Iryna M. Ethell 《Neurotherapeutics》2007,4(4):571-579
Microglial activation and macrophage infiltration into the CNS are common features of CNS autoimmune disease and of chronic
neurodegenerative diseases. Because these cells largely express an overlapping set of common macrophage markers, it has been
difficult to separate their respective contributions to disease onset and progression. This problem is further confounded
by the many types of macrophages that have been termed microglia. Several approaches, ranging from molecular profiling of
isolated cells to the generation of irradiation chimeric rodent models, are now beginning to generate rudimentary definitions
distinguishing the various types of microglia and macrophages found within the CNS and the potential roles that these cells
may play in health and disease. 相似文献
13.
Ocular manifestations of Donohue's syndrome. 总被引:2,自引:0,他引:2
INTRODUCTION: Donohue's syndrome, also known as Leprechaunism, is a rare autosomal recessive disease that manifests at birth with symptoms of endocrine dysfunction. Metabolic characteristics of the disease include postprandial hyperglycemia, fasting hypoglycemia, insulin resistance, hyperinsulinemia, and failure to thrive. The physical features most often associated with this condition include hypertrichosis, pachyderma, acanthosis nigricans, prominent genitalia, and elfin-like facial characteristics of prominent eyes, wide nostrils, thick lips, and large, low-set ears. Not only is this syndrome rare, but it often results in infant and early childhood mortality. The literature regarding ocular manifestations is limited. CASE REPORT: We present a case of a 29-year-old male with Donohue's syndrome and significant ocular findings including a subluxated mature cataract, retinal detachment, high myopia, and optic atrophy. DISCUSSION: These ocular sequelae are discussed with regard to the noted endocrine dysfunction and its effects on tissue development and growth. 相似文献
14.
Emilio Benfenati Pierluigi Farina Tina Colombo Gianluca De Bellis Mauro Valerio Capodiferro Maurizio D'Incalci 《Cancer chemotherapy and pharmacology》1989,24(6):354-358
Summary The pharmacokinetics of the anticancer agent p-(3,3-dimethyl-1-triazeno) benzoic acid (pCOOH-DMT), a drug now in phase I clinical trial in Europe, was investigated in C57 Bl female mice with M5076 reticulum-cell sarcoma that were treated i.v. with 200 mg/kg pCOOH-DMT. The drug disappeared from plasma with a terminal half-life of about 2.5 h. Plasma clearance was approximately 6 ml/min per kg. Distribution studies showed some differences in drug levels in different tissues. The highest levels were found in the tumor, liver, kidney and lung; lower levels were found in the spleen and gut, and the lowest, in the brain. The N-desmethyl derivative of pCOOH-DMT was not detectable in plasma or tissues of mice treated with the drug. Therefore, the previous evidence of low N-demethylation of pCOOH-DMT was confirmed. pCOOH-DMT glucuronide was identified by mass spectrometry and quantified by high-performance liquid chromatography (HPLC) in plasma, tissues and urine samples. pCOOH-DMT glucuronide appears to be the major urinary metabolite of pCOOH-DMT in mice. Another metabolite identified by mass spectrometry and quantified by HPLC in some tissues and urine was pCOOH-DMT glycinate.Abbreviations DTIlC
5-(3,3-dimethyl-l-triazeno)imidazole-4-carboxamide
- pCOOH-DMT
p-(3,3-dimethyl-l-triazeno)benzoic acid
- pCOOH-MMT
p-(3-methyl-l-triazeno)benzoic acid
- pCONH2-DMT
p-(3,3-dimethyl-l-triazeno)carboxamide
- BSTFA
N,O-bis(trimethylsilyl)trifluoroacetamide
- TMCS
trimethylchlorosilane
- TLC
thin-layer chromatography
- FAB
fast atom bombardment
- EI
electron impact
- M5
M5076 reticulum-cell sarcoma
- t1/2
beta-half-life
- C0
concentration time 0
- AUC
area under the concentration vs time curve
- Cl
total clearance
- V
volume of distribution 相似文献
15.
Greg Ogrinc Mark E Splaine Tina Foster Martha Regan-Smith Paul Batalden 《Academic medicine》2003,78(3):280-285
The recent pressures on clinical medicine such as the attention to medical error and the challenges of interdisciplinary care have also exerted pressure on health professions education. Educators must now gauge how to redesign education systems to adapt quickly to these disruptions. Sometimes disruptions can be self-inflicted, such as the VA National Quality Scholars Fellowship's decision to use interactive video (IV) as its primary medium for delivering the curriculum to its six sites around the nation. The authors describe how this disruption to their education system helped to fashion a learning environment that is adaptable. Along the journey from a classroom-based curriculum to an IV-based curriculum, the authors and others involved in the program learned the basic tenets of IV sessions, redefined the roles of the teachers and learners, and discovered an IV environment that functions as a complex adaptive learning system. This distance-learning curriculum can be a model for other health professions education, since it starts with simple rules, changes from within, has a tolerance for unpredictability, and continually moves forward and transforms itself despite tension. 相似文献
16.
17.
18.
Reiners J van Wijk E Märker T Zimmermann U Jürgens K te Brinke H Overlack N Roepman R Knipper M Kremer H Wolfrum U 《Human molecular genetics》2005,14(24):3933-3943
Usher syndrome (USH) is the most frequent cause of combined deaf-blindness in man. USH is clinically and genetically heterogeneous with at least 11 chromosomal loci assigned to the three USH types (USH1A-G, USH2A-C, USH3A). Although the different USH types exhibit almost the same phenotype in human, the identified USH genes encode for proteins which belong to very different protein classes and families. We and others recently reported that the scaffold protein harmonin (USH1C-gene product) integrates all identified USH1 molecules in a USH1-protein network. Here, we investigated the relationship between the USH2 molecules and this USH1-protein network. We show a molecular interaction between the scaffold protein harmonin (USH1C) and the USH2A protein, VLGR1 (USH2C) and the candidate for USH2B, NBC3. We pinpoint these interactions to interactions between the PDZ1 domain of harmonin and the PDZ-binding motifs at the C-termini of the USH2 proteins and NBC3. We demonstrate that USH2A, VLGR1 and NBC3 are co-expressed with the USH1-protein harmonin in the synaptic terminals of both retinal photoreceptors and inner ear hair cells. In hair cells, these USH proteins are also localized in the signal uptaking stereocilia. Our data indicate that the USH2 proteins and NBC3 are further partners in the supramolecular USH-protein network in the retina and inner ear which shed new light on the function of USH2 proteins and the entire USH-protein network. These findings provide first evidence for a molecular linkage between the pathophysiology in USH1 and USH2. The organization of USH molecules in a mutual 'interactome' related to the disease can explain the common phenotype in USH. 相似文献
19.
Frequent polymorphism of the mitochondrial DNA polymerase gamma gene (POLG) in patients with normal spermiograms and unexplained subfertility 总被引:4,自引:0,他引:4
Jensen M Leffers H Petersen JH Nyboe Andersen A Jørgensen N Carlsen E Jensen TK Skakkebaek NE Rajpert-De Meyts E 《Human reproduction (Oxford, England)》2004,19(1):65-70
BACKGROUND: Male fertility largely depends on the quality of sperm production, which may be affected by environmental and genetic factors. In this study, we explored a possible role of the polymerase gamma (POLG) gene polymorphism, recently reported to be associated with male infertility in some populations. METHODS: The polymorphic CAG repeat (usually 10 codons long) in the POLG gene was studied in 1298 male subjects: 429 patients with infertility/subfertility, and 869 controls (495 men from the general population with unknown fertility and 374 recent fathers). In all subjects, the POLG polymorphism was assessed in relation to their semen quality, and--in the fertile controls--with biological fecundity measured as waiting time-to-pregnancy (TTP) for the couples. In the patients lacking the common POLG allele, the outcome of the assisted reproductive techniques (ART) for the couples was evaluated. RESULTS: The absence of one (10/ not equal to 10) or both common POLG alleles (not equal to 10/not equal to 10) was more frequent among the subfertile patients than among fertile controls (P=0.021 and P=0.04 respectively). The estimated predictive value for infertility in a man homozygous for the POLG polymorphism was 15.5% (95% CI: 4.8-51%). There was a positive association with sperm concentration: 14.3% of the normospermic subfertile patients were homozygous for the absence of the common POLG allele (not equal to 10/not equal to 10), in comparison with 2.3% of unselected controls (P=0.001) and 0.9% of the fertile men (P=0.0001). No association with sperm motility, morphology and TTP was found. Spermatozoa of the three not equal to 10/not equal to 10 patients treated with IVF retained the ability to penetrate the egg, but the fertilization rate was low. Nine homozygous not equal to 10/ not equal to 10 patients were treated with ICSI, resulting in pregnancy in seven couples. CONCLUSIONS: The POLG gene polymorphism should be considered as a possible contributing factor in patients with unexplained subfertility and normal spermiograms. The oocyte penetration ability of sperm may be partially impaired in the not equal to 10/not equal to 10 patients but most of them can be successfully treated with ICSI. 相似文献
20.
Mason TC 《Journal of the National Medical Association》2002,94(2):124-126
BACKGROUND: The incidence of leiomyomas in pregnancy is approximately 1%. Their presence has been linked to spontaneous abortion, premature labor, soft tissue dystocia, uterine inertia, fetopelvic disproportion, malposition of the fetus, retention of the placenta, and postpartum hemorrhage. CASE: This case report documents a seldom-described event of a submucous leiomyoma masquerading as retained products of conception. The patient presented 4 weeks postpartum with complaints of urinary retention and heavy bleeding with cramping. Examination revealed a large mass resembling placental tissue filling the vaginal vault. The necrotic mass was removed with blunt and sharp dissection. The final pathology report revealed a degenerating leiomyoma. CONCLUSION: Complicating factors associated with this fibroid included a history of spontaneous abortion and preterm labor, as well as fetal malpresentation and carneous degeneration of the leiomyoma. Gestational myomas, although rare, can have an unusual appearance that may be misinterpreted. 相似文献