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INTRODUCTION: Helicopter cockpits are very noisy and this noise must be reduced for effective communication. The standard U.S. Army aviation helmet is equipped with a noise-canceling acoustic microphone, but some ambient noise still is transmitted. Throat microphones are not sensitive to air molecule vibrations and thus, transmittal of ambient noise is reduced. It is possible that throat microphones could enhance speech communication in helicopters, but speech intelligibility with the devices must first be assessed. In the current study, speech intelligibility of signals generated by an acoustic microphone, a throat microphone, and by the combined output of the two microphones was assessed using the Modified Rhyme Test (MRT). METHODS: Stimulus words were recorded in a reverberant chamber with ambient broadband noise intensity at 90 and 106 dBA. Listeners completed the MRT task in the same settings, thus simulating the typical environment of a rotary-wing aircraft. RESULTS: Results show that speech intelligibility is significantly worse for the throat microphone (average percent correct = 55.97) than for the acoustic microphone (average percent correct = 69.70), particularly for the higher noise level. In addition, no benefit is gained by simultaneously using both microphones. A follow-up experiment evaluated different consonants using the Diagnostic Rhyme Test and replicated the MRT results. DISCUSSION: The current results show that intelligibility using throat microphones is poorer than with the use of boom microphones in noisy and in quiet environments. Therefore, throat microphones are not recommended for use in any situation where fast and accurate speech intelligibility is essential. 相似文献
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Adrianus. M. van der Holst Antonius T. Otten Elise M. Meima-van Praag Alexander R. P. K. M. van Renterghem Arno R. Bourgonje Ellen S. van Loo Gerard Dijkstra Christianne J. Buskens Laurents P. S. Stassen 《Colorectal disease》2023,25(6):1176-1186
Aim
Creation of a diverting stoma in patients with Crohn's disease (CD) can counteract luminal inflammation. The clinical utility of a diverting stoma with the prospect of restoration of gastrointestinal continuity warrants further investigation. The aim of this work was to evaluate the long-term effects of creation of a diverting stoma on the disease course in patients with luminal colonic CD.Method
In this retrospective, multicentre cohort study we investigated the disease course of patients who received a diverting stoma in the biological era. Clinical characteristics, medication use and surgical course were assessed at the time of creation of the diverting stoma and during follow-up. The primary outcome was the rate of successful and lasting reestablishment of gastrointestinal continuity.Results
Thirty six patients with refractory luminal CD from four institutions underwent creation of a diverting stoma. Of the overall cohort, 20 (56%) patients had their gastrointestinal continuity reestablished after initial stoma creation and 14 (39%) who had their stoma reversed remained stoma-free during a median of 3.3 years follow-up (interquartile range 2.1–6.1 years). Absence of stoma reversal was associated with the presence of proctitis (p = 0.02). Colorectal resection after creation of a diverting stoma was performed in 28 (78%) patients, with 7 (19%) having a less extensive resection and 6 (17%) having a more extensive resection compared with the surgical plan before stoma creation.Conclusion
A diverting stoma could potentially be an alternative to immediate definitive stoma placement in specific populations consisting of patients with luminal colonic CD, especially in the absence of proctitis. 相似文献75.
Nipun Verma Ashok Choudhury Virendra Singh Ajay Duseja Manum Al-Mahtab Harshad Devarbhavi Chundamannil E. Eapen Ashish Goel Qin Ning Zhongping Duan Saeed Hamid Wasim Jafri Amna Shubhan Butt Akash Shukla Soek-Siam Tan Dong Joon Kim Jinhua Hu Ajit Sood Omesh Goel Vandana Midha Hashmik Ghaznian Manoj Kumar Sahu Guan Huei Lee Sombat Treeprasertsuk Samir Shah Laurentius A. Lesmana Rinaldi C. Lesmana V. G. Mohan Prasad Shiv K. Sarin APASL ACLF Research Consortium for APASL ACLF Working Party 《Liver international》2023,43(2):442-451
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Paulides MM Vossen SH Zwamborn AP van Rhoon GC 《International journal of radiation oncology, biology, physics》2005,63(2):634-642
PURPOSE: To investigate the ability to deposit radiofrequency energy centrally in the neck as a function of antenna positions, number of antennas, and operating frequency. METHODS AND MATERIALS: Power absorption (PA) distributions in a realistic model of the head-and-neck anatomy are calculated in which the head model is irradiated by an array of dipole antennas. The relative PA distributions corresponding to different setups are visualized and analyzed using the ratio of the average PA (aPA) in the target and neck region. RESULTS: Both the PA distributions and aPA ratios indicate an optimal focusing ability of the setups (i.e., the ability to direct energy efficiently into the target region), between 400 and 600 MHz. In this frequency band, the focusing ability depends only moderately on the size of the neck. Finally, it is found that the focusing ability at 433 MHz is increased significantly by increasing the number of antenna elements. CONCLUSIONS: The optimal frequency is found to be highly dependent on the size of the target volume; thus, a single optimum is hard to define. However, future clinical research will focus on 433 MHz based on the optimal range of frequencies, as found in this study. 相似文献