全文获取类型
收费全文 | 3116081篇 |
免费 | 218995篇 |
国内免费 | 4457篇 |
专业分类
耳鼻咽喉 | 43686篇 |
儿科学 | 100911篇 |
妇产科学 | 83886篇 |
基础医学 | 454012篇 |
口腔科学 | 86529篇 |
临床医学 | 282311篇 |
内科学 | 596004篇 |
皮肤病学 | 68995篇 |
神经病学 | 243144篇 |
特种医学 | 118400篇 |
外国民族医学 | 677篇 |
外科学 | 467813篇 |
综合类 | 63638篇 |
现状与发展 | 13篇 |
一般理论 | 1063篇 |
预防医学 | 238868篇 |
眼科学 | 72820篇 |
药学 | 237439篇 |
68篇 | |
中国医学 | 6565篇 |
肿瘤学 | 172691篇 |
出版年
2021年 | 24822篇 |
2019年 | 24823篇 |
2018年 | 34473篇 |
2017年 | 26269篇 |
2016年 | 29551篇 |
2015年 | 33178篇 |
2014年 | 46498篇 |
2013年 | 69709篇 |
2012年 | 95789篇 |
2011年 | 101892篇 |
2010年 | 60495篇 |
2009年 | 56862篇 |
2008年 | 95320篇 |
2007年 | 101830篇 |
2006年 | 102782篇 |
2005年 | 99421篇 |
2004年 | 95187篇 |
2003年 | 91696篇 |
2002年 | 88843篇 |
2001年 | 146554篇 |
2000年 | 150817篇 |
1999年 | 126537篇 |
1998年 | 35793篇 |
1997年 | 31423篇 |
1996年 | 31730篇 |
1995年 | 29859篇 |
1994年 | 27440篇 |
1993年 | 25884篇 |
1992年 | 97553篇 |
1991年 | 94833篇 |
1990年 | 92981篇 |
1989年 | 89478篇 |
1988年 | 82003篇 |
1987年 | 80381篇 |
1986年 | 75474篇 |
1985年 | 71964篇 |
1984年 | 53298篇 |
1983年 | 45311篇 |
1982年 | 26493篇 |
1979年 | 48774篇 |
1978年 | 34377篇 |
1977年 | 29189篇 |
1976年 | 27212篇 |
1975年 | 29746篇 |
1974年 | 35307篇 |
1973年 | 33784篇 |
1972年 | 31966篇 |
1971年 | 30209篇 |
1970年 | 27810篇 |
1969年 | 26584篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
In this study, we recorded the type of restoration and the materials used in 24,429 restorations in permanent teeth by 243 Norwegian clinicians in general practice. Demographic information included patient's gender and age, and clinician's gender, years since graduation, and practice setting (private or salaried). The overall recorded use of restorative materials in permanent teeth shows that 32% are amalgams, just over 40% composites, and about 25% glass ionomer type materials. Three percent are "other" materials. A marked shift away from amalgam restorations is noted both in the clinician's estimated use during the last 2 decades and by comparing the present use of materials with that in failed restorations. Tooth-colored materials are more commonly used in adolescents, especially glass ionomer materials, and in female patients. In patients < or = 18 years, amalgam is used in 25% of all restorations. The use of amalgam is similar in private practice and in public health service practice, but private practitioners use more composites and salaried dentists more glass ionomers. The clinician's gender does not have any effect on the selection of restorative materials. The change from amalgam to tooth-colored material is particularly noticeable for Class I and Class V restorations. Amalgam is the predominant material in 2- and 3-surface Class II restorations. 相似文献
962.
963.
964.
A R Vernino T A Ringeisen H L Wang M Derhalli J Rapley S J Nechamkin J Brekke 《The International journal of periodontics & restorative dentistry》1998,18(6):572-585
This study evaluated two bioresorbable polylactic acid barriers (Epi-Guide and Guidor) to determine if design differences were of therapeutic significance in the treatment of Grade II furcation defects in humans. Forty patients with bilaterally matched, Grade II furcation defects in maxillary or mandibular first or second molars were treated in a multicenter study. Comprehensive initial periodontal therapy, followed by defect debridement and root preparation, preceded randomized membrane placement. Data collected from all three investigative centers were pooled and analyzed using an analysis of variance appropriate for a counterbalancing design. Both barrier types produced measurable improvements of clinical probing values. Barrier exposure scores taken through the eighth week postoperative revealed that Epi-Guide was less likely to become exposed than Guidor. The findings of this study, which was conducted over a 12-month period, demonstrated that Epi-Guide and Guidor were comparable as measured by clinical probing determinations. 相似文献
965.
Sklavounou-Andrikopoulou A Iakovou M Paikos S Papanikolaou V Loukeris D Voulgarelis M 《Oral diseases》2004,10(2):118-122
Papular-purpuric 'gloves and socks' syndrome (PPGSS) is a novel, rare, self-limited dermatosis initially described in 1990. It is characterized by painful, pruritic edema and erythema, rapidly evolving to papular-purpuric lesions on the distal extremities, in a gloves-and-socks distribution, accompanied by fever and oral lesions such as petechiae, vesiculopustules and small erosions. Parvovirus B19 has been implicated in most cases as the etiological factor. Herein we present the first case of PPGSS in a 42-year-old Greek man with von Willebrand disease. On admission the patient was febrile, and presented acral edema and erythema rapidly followed by purpuric lesions on the same sites, and palatal petechiae. Complete remission of the exanthem occurred 7 days after hospitalization. Clinical and laboratory evaluation including serologic tests and PCR, confirmed the presence of parvovirus B19. Review of the existing literature on this novel syndrome and its association with parvovirus B19 is also presented. 相似文献
966.
Dean JA Bullard G Long RW Moore BK McDonald SM 《Journal (Indiana Dental Association)》2004,83(1):7-12
PURPOSE: The purpose of this study was twofold: 1. To compare two different research models for simulating a traumatic anterior tooth fracture: the blunt trauma method (standard method) and an AL2O3 sectioning method (experimental method). 2. To compare the bond strength of tooth fragments bonded with resin modified glass ionomer vs. a light cured composite resin. METHODS: Two hundred bovine incisors were used in the study and kept in plain tap water throughout. The study consisted of five basic steps: 1. Fracture of the teeth by either blunt trauma (chisel and hammer) or AL2O3 sectioning disc. 2. Luting of the fractured fragments back to the teeth using either a composite resin or resin modified glass ionomer. 3. Thermocycling of the repaired teeth. 4. Dislodging the teeth to determine the strength of repair. 5. Determination of fracture type. RESULTS: One-way ANOVA revealed a statistically significant difference in the forces required to fracture the resin modified glass ionomer and composite resin regardless of whether the teeth were originally fractured with the blunt force method (p=0.030) or the disc sectioning method (p=.001). One-way ANOVA also revealed a statistically significant difference between the forces required for fracture by blunt trauma and the disc fracture techniques with the resin modified glass ionomer group (p=0.000345). However, there was no significant difference when the two techniques were compared for the composite resin (p= 0.2941). CONCLUSIONS: 1. The resin modified glass ionomer was significantly stronger than the composite resin when both the blunt trauma and the disc fracture techniques were employed. 2. The study's results do not support substituting the ease of the AL2O3 disc for the more time-consuming blunt trauma method. 相似文献
967.
Shoulder complaints after nerve sparing neck dissections 总被引:1,自引:0,他引:1
van Wilgen CP Dijkstra PU van der Laan BF Plukker JT Roodenburg JL 《International journal of oral and maxillofacial surgery》2004,33(3):253-257
The purpose of the study was to analyse the prevalence of shoulder complaints after nerve sparing neck dissection at least 1 year after surgery, and to analyse the influence of radiation therapy on shoulder complaints. Patients were interviewed for shoulder complaints, and patients filled out the shoulder disability questionnaire to evaluate shoulder disability in daily activities. In total 137 patients; 51 after modified radical neck dissection (MRND), 21 after postero-lateral neck dissection (PLND), and 65 after supraomohyoid neck dissection (SOHND) were analysed. After MRND 33.3% of the patients experienced shoulder complaints, after PLND 66.7%, and after SOHND 20% of the patients experienced shoulder complaints. Type of neck dissection was significantly (P < 0.001) related to shoulder complaints. Outcome on the shoulder disability questionnaire also showed a significant (P < 0.01) difference in outcome for type of neck dissection. The prevalence of shoulder complaints after SOHND are low, and reduce disability in daily activities. Radiation therapy does not have a significant effect on shoulder complaints and disability. 相似文献
968.
Becker DB Grames LM Pilgram T Kane AA Marsh JL 《The Journal of craniofacial surgery》2004,15(5):804-809
The timing of surgery for velopharyngeal dysfunction has been based on assumptions about the relation between age, speech development, and velopharyngeal dysfunction. Cleft palate teams often counsel parents to have an intervention for velopharyngeal dysfunction performed earlier rather than later, believing that earlier interventions result in more rapid or better normalization of speech. The objective of this retrospective chart review study is to determine whether the age at surgical intervention for velopharyngeal dysfunction has an effect on the subsequent length of speech therapy. Of 174 patients included in the study database, 36 had velopharyngeal dysfunction for which further velopharyngeal management was required. Of the 36 patients who received surgical velopharyngeal dysfunction management, 27 had verifiable speech therapy records. These 27 patients represent the study population. The outcome measure was the total length of subsequent speech therapy until speech normalization. The data suggest that there is no relation between the age at velopharyngeal dysfunction surgical management and the amount of speech therapy needed to achieve normalization of the speech impairments secondary to velopharyngeal dysfunction after that management. In conclusion, 1) the age at surgical velopharyngeal dysfunction management (pharyngeal flap or sphincter pharyngoplasty) does not have an effect on subsequent normalization of speech as measured by the duration of speech therapy necessary to achieve normalization of the speech impairments secondary to velopharyngeal dysfunction after that management, and 2) the age at surgical velopharyngeal dysfunction management does not affect the likelihood of subsequent surgical velopharyngeal dysfunction management procedures. 相似文献
969.
Morita E Narikiyo M Nishimura E Yano A Tanabe C Sasaki H Hanada N 《Oral microbiology and immunology》2004,19(6):386-389
The purpose of this study was to survey the prevalence of streptococcal species, especially Streptococcus anginosus (which has been reported to be associated with cancer in the upper digestive tract), Streptococcus constellatus, and Streptococcus intermedius in the saliva of different age groups. A sequence analysis of 16S rDNA was performed and DNA quantified using real-time polymerase chain reaction. The S. anginosus level increased with age, whereas the levels of S. constellatus and S. intermedius did not change. Streptococcus mitis was the predominant species in the saliva of all the age groups but, unlike the S. anginosus, the proportion of S. mitis in the salivary bacteria decreased with age. The increase in S. anginosus with age should be carefully monitored because of its association with diseases, including cancer. 相似文献
970.
D'Agostino A Fior A Toffanetti G Pacino GA Scala R Trevisiol L 《Minerva stomatologica》2004,53(6):315-323
Loss of maxillary substance following trauma varies significantly in relation to the dimensions, site and type of tissue involved. Anatomical maxillary interruptions, loss of dental elements and consequent bone re-absorption give rise to altered chewing, swallowing and speech functions. Treatment of pathological conditions over the years has seen the development of surgical protocols designed to achieve simultaneous aesthetic and functional restoration of the stomatognatic apparatus. The advent of osteointegrated implantology and continual progress in pre-prosthesis surgical techniques have undoubtedly revolutionised established approaches to prosthetic rehabilitation by introducing the concept of supported implant prostheses. The implantation protocols used are a safe and reproducible treatment method suitable for adequate anchorage of such prosthetic implants; the application of such protocols in any case is subordinated to the presence of adequate morpho-volumetric bone at the skeletal bases. Depending on the entity of maxillary loss of substance, the reconstruction methods we propose, in agreement with numerous other authors, are based on the use of free and free-revascularised autologous bone grafts or, even more recently, the application of osteogenetic distraction techniques. The purpose of this article is to evaluate treatment of loss of maxillary substance following trauma by means of non-revascularised free flaps. The use of free grafts of autologous bone is elective in patients presenting bone deficits less than 6 cm with and/or without upkeep of maxillary and mandibular cortical bone continuity but without compromise to the integrity and trophism of the soft tissues. 相似文献