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Jaafar Mouhyi Lars Sennerby Jeanjacques Pireaux Nicolas Dourov Samir Nammour Jack Van Reck 《Clinical oral implants research》1998,9(3):185-194
The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed. 相似文献
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Efficacy of an air-cleaning device equipped with a high efficiency particulate air filter in house dust mite respiratory allergy 总被引:3,自引:2,他引:1
The efficacy of an air-cleaning device equipped with a high efficiency particulate air (HEPA) filter (without further avoidance measures) was studied in patients allergic to house dust mite. The effects of the air-cleaner on indoor Dermatophagoides sp. levels, symptom score and bronchial hyperresponsiveness in nine mite-allergic patients were assessed using a cross-over controlled study. No significant effect was demonstrated on indoor Dermatophagoides sp. levels when comparing the period of air-cleaner activity (2 months) with the control period (2 months). The Dermatophagoides sp. levels in the houses studied were lower than the risk level for asthmatic attacks, making it difficult to assess any effect on asthma; however, neither bronchial hyperresponsiveness nor rhinitis symptom score were changed by air-cleaner activity. During the trial period, however the mean level of Dermatophagoides sp. allergen in the houses changed spontaneously from 4.4 micrograms/g (mean level in the first 2 trial months) to 1.75 micrograms/g of dust (second 2 months) (P less than 0.05). Owing to this change, the mean rhinitis symptom score also decreased (P less than 0.05), even if no significant correlation was demonstrated (r = 0.4 P = 0.089). HEPA filter air-cleaners appear insufficient as substitutes for standard avoidance measures in mite allergic patients. 相似文献
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目的 评价体位、性别、手术、膀胱充盈状态对直肠癌放疗后肠受照射的影响。方法36例直肠癌患者被研究,盆腔放疗采用1后2侧野三维适形放射治疗(3DCRT)的方法,处方剂量为50Gy。利用每个计划的剂量.体积直方图(DVH)对盆腔内肠的受照剂量和体积进行分析。结果膀胱充盈差和好时肠受照射的平均剂量分别是23.8和18.3Gy(P=0.004),V45高剂量受照体积分别是15.7%和7.8%(P=O.004);体位仅对肠V15,低剂量受照体积有显著影响;性别对肠受照射的最大剂量和V15,有显著影响;手术对肠受照射的平均剂量有显著影响,分别是术前19.0Gy和术后22.5Gy(P=0.015);在仰卧或俯卧、术前或术后膀胱充盈好时均比差时肠受照射剂量要低或体积要小。膀胱充盈好和差时肠受到高剂量照射的体积V4,在俯卧位分别是15.3%和7.4%(P=0.023),术后分别是14.1%和7.2%(P=0.014),差异有统计学意义。结论 患者治疗体位、性别、手术对盆腔内肠受照射剂量和体积有一定的影响,膀胱充盈状态有显著影响。 相似文献
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The purpose of this study is to describe the characteristic computed tomographic (CT) signs of small bowel perforation after
blunt abdominal trauma and to evaluate their sensitivity. Nineteen preoperative CT scans were obtained from 16 patients with
surgically proven small bowel rupture secondary to blunt abdominal trauma. Only the CT findings described in the original
CT reports were used. Eleven of 19 CT scans (58 %) had findings that were unequivocal for bowel rupture (i.e., extraluminal
air and/or extravasation of oral contrast medium). Seven CT scans (37 %) had findings that were suggestive of severe small
bowel injury (i.e., focal small bowel wall thickening and/or free peritoneal fluid without other accompanying organ injuries).
In all, 95 % of cases of small bowel rupture had either pathognomonic or suggestive CT findings. One CT scan did not demonstrate
small bowel wall thickening, although a hemoperitoneum was present. CT is a sensitive method for suggesting severe small bowel
injury and rupture secondary to blunt abdominal trauma. 相似文献
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This study is aimed at detecting gastrointestinal sounds (GIS) and correlating their characteristics with gastrointestinal
(GI) conditions. The central hypotheses are that GIS generation depends on the motility patterns and the mechanical properties
of the gut, and that changes in those result in measurable differences in GIS. An animal model which included both healthy
rats and those with small bowel obstruction (SBO) was developed. The acoustic bursts, of GIS were detected by amplitude thresholding
the signal envelope. Three methods of envelope estimation were proposed and evaluated. Envelope estimation using a Hilbert
transform was found to produce the best results in the current application. The duration and dominant frequency of each detected
GIS event was estimated and clear differences between healthy and diseased rats were discovered. In the control state, GIS
events were found to consistently be of relatively short duration (3–65ms). Although the majority of events in the SBO state
had similar short duration, infrequent longer events were also detected and appeared to be pathognomonic. Long duration events
(>100 ms) occurred in each of seven obstructed, but in none of 14 non-obstructed, cases (p<0.001). It is concluded that GIS
analysis may prove useful in the non-invasive, rapid, and accurate diagnosis of SBO. 相似文献