全文获取类型
收费全文 | 13882篇 |
免费 | 1186篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 338篇 |
儿科学 | 546篇 |
妇产科学 | 268篇 |
基础医学 | 2025篇 |
口腔科学 | 187篇 |
临床医学 | 1625篇 |
内科学 | 3006篇 |
皮肤病学 | 244篇 |
神经病学 | 1510篇 |
特种医学 | 477篇 |
外国民族医学 | 1篇 |
外科学 | 1641篇 |
综合类 | 239篇 |
现状与发展 | 1篇 |
一般理论 | 12篇 |
预防医学 | 965篇 |
眼科学 | 280篇 |
药学 | 800篇 |
中国医学 | 38篇 |
肿瘤学 | 883篇 |
出版年
2022年 | 88篇 |
2021年 | 192篇 |
2020年 | 135篇 |
2019年 | 192篇 |
2018年 | 203篇 |
2017年 | 152篇 |
2016年 | 212篇 |
2015年 | 221篇 |
2014年 | 325篇 |
2013年 | 529篇 |
2012年 | 674篇 |
2011年 | 746篇 |
2010年 | 459篇 |
2009年 | 364篇 |
2008年 | 680篇 |
2007年 | 699篇 |
2006年 | 687篇 |
2005年 | 794篇 |
2004年 | 652篇 |
2003年 | 626篇 |
2002年 | 574篇 |
2001年 | 327篇 |
2000年 | 318篇 |
1999年 | 274篇 |
1998年 | 195篇 |
1997年 | 157篇 |
1996年 | 140篇 |
1995年 | 125篇 |
1994年 | 128篇 |
1993年 | 122篇 |
1992年 | 183篇 |
1991年 | 190篇 |
1990年 | 195篇 |
1989年 | 175篇 |
1988年 | 159篇 |
1987年 | 162篇 |
1986年 | 157篇 |
1985年 | 127篇 |
1984年 | 124篇 |
1983年 | 135篇 |
1982年 | 136篇 |
1981年 | 153篇 |
1980年 | 138篇 |
1979年 | 142篇 |
1978年 | 114篇 |
1977年 | 126篇 |
1976年 | 111篇 |
1975年 | 85篇 |
1974年 | 131篇 |
1973年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Osteonecrosis of the jaws associated with use of risedronate: report of 2 new cases. 总被引:1,自引:0,他引:1
John K Brooks Allen J Gilson Arnold J Sindler Steven G Ashman Kevin G Schwartz Nikolaos G Nikitakis 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,103(6):780-786
Use of various bisphosphonates has been associated with the development of osteonecrosis of the jaws (ONJ). At least 865 cases of ONJ attributed to these agents have been reported in the English-language literature. Approximately 96% of these published cases were seen with administration of the intravenous agents pamidronate and zoledronate, whereas only 26 cases have been associated with oral bisphosphonates, 25 of them with alendronate. Only a single case of ONJ associated with the oral bisphosphonate risedronate has been previously cited. We report 2 cases of ONJ attributed to risedronate administration. The patients developed osteonecrosis 15 and 24 months after treatment for osteopenia. A regimen of antibiotics and chlorhexidine mouthrinse resolved the osseous defect in the mandible caused by complete exfoliation of a lingual torus in 1 patient. The other patient required sequestrectomy, repeated courses of antibiotics, surgical debridement, and steroids to promote closure of an oroantral fistula and management of sinusitis after bone grafting and implant placement in the posterior maxilla. A demographic profile of reported oral bisphosphonate users affected by ONJ is also provided. With the millions of patients receiving various oral bisphosphonates for osteopenia and osteoporosis, health care practitioners should be aware of the potential for the onset of osteonecrosis and familiar with its management. 相似文献
72.
73.
Background: Ultrasonography is becoming an important adjunct in paediatric neuraxial blockade. Ultrasound guidance helps in visualisation of relevant neuraxial structures, predicting depth of epidural space from skin, reduction in bony contact and faster epidural placement. The visibility of neuraxial structures declines in patients as age increases. To date, there are no studies looking at the extent of spread of local anaesthetic solution in the epidural space and its correlation to the volume used, under ultrasound guidance. We report the results of our audit on spread of local anaesthetic solution in the epidural space in single shot caudal blocks. This abstract is based on the first 17 patients, the presentation will be based on all 50 patients. Methods: This audit was approved by the local audit committee. We aimed to follow the extent of the spread of local anaesthetic within the epidural space with real time ultrasonography. Patients were selected when the planned anaesthetic included a single shot caudal block. The anaesthetists performing the anaesthetic and the caudal block consented to our ultrasound visualisation. All patients were below 5 years of age. No attempt was made to standardise the technique, the dose, or the speed of injection. After the placement of the caudal cannula by the primary anaesthetist involved in patient care, a separate anaesthetist, experienced in using ultrasound, visualised the neuraxial structures and subsequent spread of the local anaesthetic solution with real time ultrasound. The spread was followed during the injection and for 10 s after the completion of the injection. A 5 cm 7.5–12 MHz linear array was used longitudinally with either midline or paramedian approach. Results: We are reporting the preliminary results from 17 patients. Patients were aged between 1 day and 1 year 10 months. They weighed between 3.3 kg and 14.6 kg. Either 22 gauge Jelco or Abbocath were used to perform the procedure; 0.25% or 0.20% L‐bupivacaine was used on all occasions. The volume administered per kg ranged between 0.33 and 1.27 ml. The visibility of neuraxial structures was good on all occasions. On calculating the Spearmans correlation coefficient, the extent of spread of local anaesthetic in the epidural space was positively correlated with the volume used by a correlation coefficient of 0.64, with a P value of 0.008. The postoperative pain score in recovery was 0 in 16 out of the 17 cases. The one failure occurred when the observed spread would not have been expected to provide analgesia for the performed operation. Conclusions: Among children below 5 years of age, there seems to be a positive correlation between the volume of local anaesthetic injected into the epidural space and the extent of its spread. This needs to be further investigated by a prospective randomised control trial. The utility of real time ultrasound to allow a reliable achievement of a desired level of sensory block, should be investigated i.e, whether the volume used in achieving a desired level of local anaesthetic spread, as guided by ultrasound, provides superior analgesia and fewer adverse effects compared with the volume calculated using the Armitage regimen. References 1 Rapp HJ, Folger A, Grau T. Ultrasound guided epidural catheter insertion in children. Anesth Analg 2005; 101 : 333–339. 2 Willschke H, Marhofer P, Bosenberg A, et al. Epidural catheter placement in children: comparing a novel approach using ultrasound guidance and a standard loss of resistance technique. Br J Anaesth 2006; 97 : 200–207. 3 Marhofer P, Bosenberg A, Sitzwohl C et al. Pilot study of neuraxial imaging by ultrasound in infants and children. Pediatr Anesth 2005; 15 : 671–676. 相似文献
74.
75.
Eva-Maria Brick Heike Rudolph Jens Arnold Ralph G Luthardt 《Computerized medical imaging and graphics》2004,28(3):159-165
The three-dimensional (3D) evaluation and comparison of free-form-surfaces is a complex problem [Dent. Mater. 8 (1992) 49; J. Dent. Res. 76 (1997) 1799; Dent. Mater. 16 (2000) 145; J. Prosthet. Dent. 70 (1993) 457; Dent. Mater. 19 (2003) 19]. However, it is essential in order to analyze the sinter shrinkage of dental ceramic-restorations where isotropic and linear shrinkage is desired for accurate fit on the prepared teeth. In this article, we examine the 3D sinter shrinkage in general and for nine copings from alumina in particular. Using various scaled CAD-models in an iteration scheme, each model was compared to the filtered point cloud of the coping, determining the surface-cloud difference. The magnitude of deviations from linear sinter shrinkage was investigated. Furthermore, a new fabrication process for ceramic-restorations is introduced. 相似文献
76.
Cerebral Cortical Aquaporin-4 Expression in Brain Edema following Cardiac Arrest in Rats 总被引:14,自引:0,他引:14
Feng Xiao MD MS Thomas C. Arnold MD Shu Zhang MD Carlos Brown J. Steven Alexander PhD Donna L. Carden MD Steven A. Conrad MD PhD 《Academic emergency medicine》2004,11(10):1001-1007
OBJECTIVES: Brain edema occurs following clinical as well as experimental cardiac arrest (CA) and predicts a poor neurologic outcome. The objective of this study was to determine the expression of cerebral cortex aquaporin (AQP)-4, a member of a family of membrane water-channel proteins, in brain edema formation following normothermic or hypothermic CA. METHODS: Twenty-four rats were subjected to time-matched normothermic (N-Sham, 37.5 degrees C +/- 0.5 degrees C, n = 6) or hypothermic (H-Sham, 34 degrees C +/- 0.5 degrees C, n = 6) sham experiments and normothermic (N-CA, n = 6) or hypothermic (H-CA, n = 6) CA induced by asphyxiation for 8 minutes. Hypothermia was induced before CA. The animals were resuscitated with cardiopulmonary resuscitation, ventilation, and epinephrine administration. Brain edema was determined by brain wet-to-dry weight ratio at one hour of resuscitation. AQP4 immunoactivity in the cerebral cortex was determined using immunohistochemical staining and was semiquantified as an intensity of staining with an automated cell imaging system. RESULTS: Mild hypothermia in the sham experiments did not alter cerebral cortex AQP4 immunoactivity (mean +/- SD) (55.0 +/- 3.7 in H-Sham vs. 53.3 +/- 1.7 in N-Sham, p > 0.05). N-CA resulted in a significant increase in AQP4 immunoactivity (61.8 +/- 4.5) compared with N-Sham (p = 0.01) and H-Sham (p = 0.03). H-CA attenuated AQP4 compared with N-CA (53.4 +/- 1.3, p = 0.01). Brain wet-to-dry weight ratios were 4.41 +/- 0.07 in N-Sham, 4.40 +/- 0.08 in H-Sham (p > 0.05 vs. N-Sham), 4.55 +/- 0.04 in N-CA (p = 0.004 vs. N-Sham; p = 0.005 vs. H-Sham), and 4.43 +/- 0.09 in H-CA (p = 0.02 vs. N-CA; p > 0.05 vs. N-Sham and H-Sham). CONCLUSIONS: Cerebral cortical AQP4 expression is up-regulated after normothermic CA, which is attenuated by hypothermia induced before CA. 相似文献
77.
78.
George Karpati Djordje Ajdukovic Douglas Arnold Robert B. Gledhill Ronald Guttmann Paul Holland Penelope A. Koch Eric Shoubridge Desmond Spence Michel Vanasse Gordon V. Watters Michael Abrahamowicz Catherine Duff Ronald G. Worton 《Annals of neurology》1993,34(1):8-17
One biceps muscle of 8 patients with Duchenne muscular dystrophy was injected at 55 sites with a total of 55 million viable, purified, and contamination-free normal myoblasts (myoblast transfer). The other biceps of each patient was injected with a placebo to serve as a control. The procedure was blinded to the patients, parents, and investigators. Myoblasts derived from a biopsy specimen of the fathers were cultured and purified under strict conditions and carefully screened for microbial contamination. All patients received cyclophosphamide for immunosuppression for 6 or 12 months. No serious complications were observed after myoblast transfer, indicating that the procedure is safe. The overall therapeutic efficiency of myoblast transfer was poor as judged by the results in maximal voluntary force generation, dystrophin content of the muscle, magnetic resonance imaging of the muscle, and the lack of donor-derived DNA and dystrophin messenger RNA in the injected muscle. An improved efficiency of the take of myoblasts might be achieved by using younger cells and injecting the myoblasts with a myonecrotic agent (to increase the prevalence of regeneration) and a basal laminal fenestrating agent. 相似文献
79.
Insulin and IGF-1 binding in chick sclera 总被引:2,自引:0,他引:2
R J Waldbillig D R Arnold R T Fletcher G J Chader 《Investigative ophthalmology & visual science》1990,31(6):1015-1022
The sclera of embryonic (days 10 and 14) and young adult (2-week posthatching chicks) contains distinct binding sites for insulin and for insulin-like growth factor-1 (IGF-1). Since there is a nearly 50% decrease in insulin and IGF-1 binding between embryonic day 10 and the 2nd week posthatching, it is clear that these sites are developmentally regulated. The affinity of each binding site for its ligand is stable across development. This suggests that the developmental decrease in binding is the result of a decrease in the number of binding sites. The insulin binding site in the sclera is specific for insulin since it has a high affinity for insulin and a lower affinity for IGF-1 (IC50 for unlabeled insulin = 0.4 nM; unlabeled IGF-1 = 5.0 nM). The embryonic chick sclera also contains two high-affinity IGF-1 binding sites. One of these sites exhibits poor binding specificity since it has an equal affinity for insulin and IGF-1. However, the specificity of this site increases in the young adult. The second IGF-1 binding site exhibits a more conventional specificity in that it has a higher affinity for IGF-1 than for insulin. The specificity of this binding site also improves in the young adult. The presence of insulin and IGF-1 receptor binding site subtypes is not correlated with structurally different receptor binding subunits since only a single population of binding subunits is observed (apparent molecular weight of 125 +/- 2.7 kD) in embryonic and adult sclera.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
80.
J. C. Arnold J. G. O'Grady J. M. Tredger R. Williams 《European journal of clinical pharmacology》1990,39(3):257-260
The following study of cyclosporine pharmacokinetics was performed to investigate the effects of withdrawal of low-dose maintenance prednisolone (0.3-0.6 mg/kg body weight) from the routine immunosuppressive regimen given to 10 liver transplant recipients with stable liver function tests. After oral administration of cyclosporine (6.4-10.3 mg/kg) whole blood concentrations were measured by radioimmunoassay (RIA) with both a specific monoclonal antibody detecting parent drug and a non-specific antibody additionally detecting a cross-section of metabolites. Withdrawal of prednisolone produced no significant change in the mean time and concentration of maximum blood cyclosporine (3.3 h and 1160 micrograms/l, respectively), the initial and terminal elimination half-life (3.5 h and 18.4 h, respectively) and the area under the blood concentration versus time curve (AUC) measured with either the specific or non-specific monoclonal antibody. Measurements with these two antibodies indicated that the terminal elimination of cyclosporine metabolites was more rapid than for the parent drug (half-life: 14.5 vs 18.4, respectively). 相似文献