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991.
The aim of this study was to determine size, shape and position of the image layer by evaluation of the radiographic image formation in different anatomic positions. A customized phantom was made of a rectangular acrylic plate measuring 14 cm2 and 0.3 cm thick, with holes spaced 0.5 cm away and arranged in rows and columns. Each column was separately filled with 0.315 cm diameter metal spheres to acquire panoramic radiographs using the Orthopantomograph OP 100 unit. The customized phantom was placed on the mental support of the device, with its top surface kept parallel to the horizontal plane, and was radiographed at three different heights from the horizontal plane, i.e., the orbital, occlusal and mandibular symphysis levels. The images of the spheres were measured using a digital caliper to locate the image layer. The recorded data were analyzed statistically by the Student'-t test, ANOVA and Tukey' test (?=0.05). When the image size of spheres in horizontal and vertical axes were compared, statistically significant differences (p<0.05) were observed in all areas, portions of the image layer and heights of horizontal plane evaluated. In the middle portion of the image layer, differences in the image size of spheres were observed only along the horizontal axis (p<0.05), whereas no differences were observed along the vertical axis (p>0.05). The methodology used in this determined the precise size, shape and position of the image layer and differences in magnification were observed in both the horizontal and vertical axes.  相似文献   
992.
This article reports the case of a large calcifying epithelial odontogenic tumor in a patient with tuberous sclerosis complex. The calcifying epithelial odontogenic tumor, one of the rarest odontogenic tumors, is reviewed in detail, as is the unusual disorder of tuberous sclerosis complex.  相似文献   
993.
In the last decade chemotherapy has gained widespread acceptance in the treatment of oral and pharyngeal cancer. Current standard treatment for advanced lesions consists of concomitant radiation and chemotherapy. This approach has provided marginal improvement of prognosis for Stage III-IV disease. Recent studies have explored the idea that locally delivered cytotoxic drugs could further improve prognosis in this patient population. We review this literature with the objective of popularizing these data and suggesting future directions for treatment and clinical research for head and neck cancer.  相似文献   
994.
Patel HB  Fleming GJ  Burke FJ 《British dental journal》2004,196(11):695-700; discussion 685; quiz 707
OBJECTIVE: The aim of the current study was to assess the puncture resistance and stiffness of nitrile and latex dental examination gloves. METHODS: Puncture resistance was measured by employing an adapted version of ASTM F1342-91 using both a 316 stainless steel puncture probe (0.8 mm diameter) and a dental injection needle (0.45 mm diameter) interfaced to a tensile testing apparatus. Glove specimens (12 cm length, 1.5 cm breadth) were removed for modulus (M100) evaluation by assessing the force required to elongate the specimen to 100% of the original length. Glove samples were also aged to investigate whether puncture resistance and M100 values varied with aging at 70 degrees C for 7 days in an air-circulating oven. RESULTS: The nitrile glove types were assessed to have significantly higher puncture resistance compared with the latex glove type when the steel puncture probe was the pentrometer when using the one way analysis of variance (ANOVA) at the 95% significance level. Interestingly the puncture resistance for the latex glove type was significantly higher (P < 0.001) when a dental injection needle was used as the pentrometer compared with the nitrile glove types. The M100 values were significantly higher for the nitrile glove types for which the stiffness increased when the gloves were aged (P < 0.001). CONCLUSIONS: The higher stiffness values resulted in increased puncture resistance when the nitrile glove specimens were aged irrespective of the pentrometer type. However, the ability of latex to re-seal itself on puncture may be beneficial when considering the protection potential of each glove type against breaches in cross infection. For clinicians that have experienced an adverse reaction to natural latex gloves, the results of the current study indicate that nitrile gloves are available at reasonable cost and offer the clinician comparable resistance to puncture with latex gloves.  相似文献   
995.
OBJECTIVES: Transient sensitivity during bleaching is generally reported to affect 67% of patients. While most people tolerate this sensitivity, some find it impossible to continue treatment. The purpose of this study was to determine the safety and efficacy of an experimental, low-sensitivity bleaching agent. METHOD AND MATERIALS: Twenty-two participants bleached for a minimum of 6 hours per night over a 2-week period. The bleaching agent used, Experimental Product E, is a 10% carbamide peroxide gel containing potassium nitrate and sodium fluoride. Evaluations were performed at baseline and 1,2,13, and 26 weeks. Color change was measured using a value-ordered Vita classic shade guide and a colorimeter. Sensitivity of the teeth, gingiva, tongue, and/or throat was measured daily using a patient log. RESULTS: The median color change after 2 weeks was eight tabs. Approximately 36% reported sensitivity during the active whitening phase of the study. As a group, participants reported sensitivity during 13.7% of the total days spent whitening. CONCLUSION: Experimental Product E was shown to be safe. Participants experienced minor sensitivity during the active bleaching phase only. Experimental Product E was shown to be an effective bleaching agent for the subjects tested in this study.  相似文献   
996.
Academic dental institutions are the fundamental underpinning of the nation's oral health. Education, research, and patient care are the cornerstones of academic dentistry that form the foundation upon which the dental profession rises to provide care to the public. The oral health status of Americans has improved dramatically over the past twenty-five to thirty years. In his 2000 report on oral health, the Surgeon General acknowledges the success of the dental profession in improving the oral health status of Americans over the past twenty-five years, but he also juxtaposes this success to profound and consequential disparities in the oral health of Americans. In 2002, the American Dental Education Association brought together an ADEA President's Commission of national experts to explore the roles and responsibilities of academic dental institutions in improving the oral health status of all Americans. They have issued this report and made a variety of policy recommendations, including a Statement of Position, to the 2003 ADEA House of Delegates. The commission's work will help guide ADEA in such areas as: identifying barriers to oral health care, providing guiding principles for academic dental institutions, anticipating workforce needs, and improving access through a diverse workforce and the types of oral health providers, including full utilization of allied dental professionals and collaborations with colleagues from medicine.  相似文献   
997.
The power of children over adults when obtaining sweet snacks   总被引:2,自引:0,他引:2  
Summary. Background. There is evidence to suggest that the family is becoming a more democratic unit and that children are spending more on sweet snack items than ever before. A study was thus undertaken to investigate the influence of children on parental decision‐making in relation to the use of sugary snacks. Methods. A cross sectional interview study; children aged 7–8 years from 20 inner‐city Manchester primary schools were asked about their sweet eating, their pocket money and their perceived levels of influence or autonomy within the household. The parents of these children were also asked to fill in a questionnaire that mirrored the children's questions. Results. There was a moderate but significant correlation between the opinion of the parents and that of the children on the extent of influence (Pearson coefficient r = 0·25, P = 0·001). When the adults (n = 181) were split into age groups, ≤ 29 years (n = 33), 30–35 years (n = 61) and ≥ 36 years (n = 87), the study showed that the older the adult, the less the child seemed to get his or her own way. Spearman's rho = 0·16, P = 0·03 (children's view) and rho = 0·17, P = 0·02 (adult's view). The dominant factors were related to money in the children's opinion, although the adults’ data suggested that older mothers (≥ 36 years) may be trying to limit their children's access to sweet snacks. Conclusions. Adults’ efforts to limit their children's intake of sweet snacks and drinks are being undermined by earlier and earlier influences in the child's life and by access to money, which allows the child to out‐manoeuvre his or her parents. This is compounded by the provision of additional income, mostly from grandparents.  相似文献   
998.
A study was undertaken to determine the prevalence and distribution of attached cementicles on different root surfaces of 415 extracted human incisors, canines, premolars and molars. The teeth were boiled in water and soaked in a 5.25% solution of sodium hypochlorite to clean the root surfaces of any soft tissue and debris. Examination with a dissecting microscope showed cementicles on 144 (34%) of the teeth. Cementicles were seen on approximately 50% of the canines and molars and on fewer than 50% of the other teeth. On canines, cementicles were found most frequently in the middle and apical thirds of the roots. On molars, cementicles were found most frequently in furcations. A relationship was noted between the presence of enamel pearls in molar furcations and enamel projections from the cementoenamel junction. The findings suggest that cementicles occur in certain locations frequently enough to be of clinical importance.  相似文献   
999.
The purpose of this study was to describe the distribution of advanced periodontal destruction (pocket depth equal to or deeper than six mm) in continuous residents, aged 27 to 74 years, of Lordsburg and Deming, New Mexico. The distance from the free gingival margin to the base of the gingival crevice or pocket was measured on the facial and mesiofacial sides of six index teeth. The presence of supragingival calculus, subgingival calculus, and plaque, as well as gingival bleeding around the index teeth, also were evaluated. Of the 372 examinees, only 46 individuals (12.4 percent) had at least one deep pocket equal to or deeper than six mm on at least one site on the six index teeth. Age was significantly associated with prevalence of deep pockets, although about 80 percent of those aged 47 to 74 years did not have deep pockets. Of those with deep pockets, 89.1 percent had fewer than four tooth sites (out of 12) affected. The only significant risk factor of the presence of deep pockets, other than age, was the number of teeth with plaque accumulations. Age and the number of teeth with plaque explained only 10.5 percent of the variability in the prevalence of deep pocketing, suggesting that risk factors other than those included in this study may be important. The results of this study indicate that destructive periodontal disease occurs at selected sites within the mouth, and that about 87 percent of the adults over age 27, in this population, do not have deep pockets in the six index teeth examined.  相似文献   
1000.
Eighty-two patients with audible clicking were evaluated and treated with splints made by using arthrographic assistance. In the course of this study, it became apparent that the later the opening click, the earlier the closing click. It was not always possible to auscultate or palpate either an opening or a closing click in many patients with arthrographic findings of disk displacement with reduction. Since the opening click was the only audible sound in some patients, clinical judgment alone cannot be used to replace the displaced disk at an optimal mandibular position. The elimination of the opening click does not always signify recapture of the disk. Maxillomandibular and incisal relationships limit the amount of protrusion possible to recapture the displaced disk.  相似文献   
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