全文获取类型
收费全文 | 17000篇 |
免费 | 1100篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 145篇 |
儿科学 | 468篇 |
妇产科学 | 350篇 |
基础医学 | 2551篇 |
口腔科学 | 423篇 |
临床医学 | 1678篇 |
内科学 | 3498篇 |
皮肤病学 | 419篇 |
神经病学 | 1917篇 |
特种医学 | 714篇 |
外科学 | 2051篇 |
综合类 | 63篇 |
一般理论 | 5篇 |
预防医学 | 1143篇 |
眼科学 | 275篇 |
药学 | 1162篇 |
中国医学 | 44篇 |
肿瘤学 | 1268篇 |
出版年
2023年 | 114篇 |
2022年 | 192篇 |
2021年 | 394篇 |
2020年 | 247篇 |
2019年 | 371篇 |
2018年 | 442篇 |
2017年 | 352篇 |
2016年 | 459篇 |
2015年 | 503篇 |
2014年 | 631篇 |
2013年 | 788篇 |
2012年 | 1243篇 |
2011年 | 1261篇 |
2010年 | 726篇 |
2009年 | 721篇 |
2008年 | 1052篇 |
2007年 | 1096篇 |
2006年 | 1112篇 |
2005年 | 1111篇 |
2004年 | 1010篇 |
2003年 | 958篇 |
2002年 | 867篇 |
2001年 | 205篇 |
2000年 | 170篇 |
1999年 | 182篇 |
1998年 | 192篇 |
1997年 | 133篇 |
1996年 | 104篇 |
1995年 | 92篇 |
1994年 | 97篇 |
1993年 | 70篇 |
1992年 | 84篇 |
1991年 | 81篇 |
1990年 | 72篇 |
1989年 | 55篇 |
1988年 | 58篇 |
1987年 | 61篇 |
1986年 | 43篇 |
1985年 | 43篇 |
1984年 | 59篇 |
1983年 | 49篇 |
1982年 | 35篇 |
1981年 | 28篇 |
1980年 | 35篇 |
1979年 | 29篇 |
1978年 | 35篇 |
1977年 | 20篇 |
1976年 | 28篇 |
1973年 | 17篇 |
1954年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
It is suggested that the numerous variants of diverticula occurring in the region of the major duodenal papilla should be grouped into four types. Type I--the major duodenal papilla (MDP) is on the floor of the diverticulum; type II--the MDP is in the region of the lower ++semi-circumference of the diverticular orifice while the longitudinal fold runs radially on the wall of the diverticulum; type III--the MDP is in the region of the orifice of the diverticulum while the longitudinal fold does not pass on its wall; type IV--two diverticula located above the MDP to both sides of the longitudinal fold. Endoscopic papillosphincterotomy is considered contraindicated in patients with type I diverticulum. When indicated, the intervention was carried out in patients with types III and IV diverticula. Endoscopic papillosphincterotomy can be conducted in patients with type II diverticulum measuring more than 2 cm. 相似文献
22.
Brenda M Sandmaier Storb Rainer Yanfang Liu Erlinda B Santos Eileen Bryant Friedrich G Schuening H Joachim Deeg Kristy Seidel Theodore Graham 《Transplant immunology》1996,4(4):271-274
920 cGy total body irradiation (TBI) is adequate for consistently successful engraftment of marrow from dog leukocyte antigen (DLA)-identical littermates; however, the dose is inadequate to ensure a marrow graft from DLA-nonidentical unrelated donors. Such mismatched grafts are successful only after 1800 cGy, given in three fractions. While anti-T-cell reagents enhance engraftment of DLA-identical littermate marrow after 920 cGy, they fail to be effective in the DLA-nonidentical setting. However, a monoclonal antibody (mAb) to CD44, S5, was found to be very effective in enhancing engraftment of DLA-nonidentical marrow. The current study asked whether mAb S5 was also effective in the setting of DLA-identical littermate transplants. To this purpose, the TBI dose was lowered to 450 cGy, a dose after which 70% of such grafts failed. Four dogs were treated with antibody S5, 0.2 mg/kg on days −7 though −2 (per previously published protocol), given 450 cGy TBI followed by marrow grafts from their DLA-identical littermates. All four dogs rejected their grafts; two of these died from marrow aplasia, and two survived with endogenous marrow recovery. This result was not statistically significantly different from that in 17, historical (n = 5) and concurrent (n = 12), control dogs where 11 of 17 animals rejected. Even if ten experimental animals were transplanted and all six remaining dogs engrafted, the results still would not have been significantly different from control. This result is in contrast to the successful engraftment promoted by pretreatment with antibody S5 of DLA-nonidentical unrelated dogs, consistent with the notion that different host cells are involved in graft rejection in the two disparate histocompatibility settings. 相似文献
23.
Peter Schnider MD Joachim Maly PhD Josef Grünberger PhD Susanne Aull MD Karl Zeiler MD Peter Wessely MD 《Headache》1995,35(5):269-272
A considerable proportion of headache patients fulfill the criteria of "drug abuse" (definition according to the International Headache Society [IHS] criteria). These patients exhibit markedly reduced vigilance and continuous performance, as shown by the results of critical flicker frequency (CFF) analysis.
The present study deals with the question whether this impairment of vigilance and continuous performance is reversible. Forty-eight headache patients with drug abuse were investigated three times by means of CFF analysis: immediately before (A), immediately after (B), and 3 weeks after having finished (C) inpatient drug withdrawal.
Immediately after withdrawal, a significant decrease of headache intensity was observed. The CFF values, however, remained unchanged at a depressed level, probably due to withdrawal medication and the initial sedative side effects of thymoleptic agents (given as prophylaxis).
Three weeks after withdrawal, however, the CFF values were significantly improved, and were now within a range not far from the normal values known from a healthy general population. Thus, even after many years of drug abuse, headache patients have a good chance to improve their vigilance and continuous performance and to reach normal or close to normal levels. 相似文献
The present study deals with the question whether this impairment of vigilance and continuous performance is reversible. Forty-eight headache patients with drug abuse were investigated three times by means of CFF analysis: immediately before (A), immediately after (B), and 3 weeks after having finished (C) inpatient drug withdrawal.
Immediately after withdrawal, a significant decrease of headache intensity was observed. The CFF values, however, remained unchanged at a depressed level, probably due to withdrawal medication and the initial sedative side effects of thymoleptic agents (given as prophylaxis).
Three weeks after withdrawal, however, the CFF values were significantly improved, and were now within a range not far from the normal values known from a healthy general population. Thus, even after many years of drug abuse, headache patients have a good chance to improve their vigilance and continuous performance and to reach normal or close to normal levels. 相似文献
24.
Yukako Sato Masahiko Aoyama Tomoko Soeda Akihiko Hoshi Mari Honma Teiji Yamamoto 《Clinical neurology》2004,44(8):527-530
A 65-year-old woman with diabetes mellitus and chronic otitis media developed headache, fever, and hoarseness, all of which did not responded to the oral antibiotics. As stiff neck and lower cranial nerve palsies appeared, bacterial meningitis was suspected. Neurological examination revealed the right hearing disturbance, right recurrent laryngeal nerve palsy, left sternocleidomastoid muscle atrophy and bilateral tongue atrophy. The CSF examination revealed mild pleocytosis and elevated protein, but no bacterial organism was cultured from the CSF. CT scans showed bilateral mastoiditis, and the right mastoid process and a posterior part of the petrous bone were eroded, indicating the exposed bony structures to the posterior fossa. MRI scans demonstrated the thickening of the dura mater of the posterior fossa and the right cerebellar tentorium. This is a rare example of bacterial pachymeningitis of the posterior fossa, the clinical symptoms and MRI findings of which resolved solely by antimicrobial agents without corticosteroid. 相似文献
25.
Bone marrow punctures and pain 总被引:1,自引:0,他引:1
We prospectively analysed pain in 263 patients induced by a frequent diagnostic procedure for oncologists, specifically the bone marrow puncture. Substantial pain (5 and more out of 10 on a numerical rating scale) was reported by 30.4% of patients, but physicians did not realize this procedure-related pain of patients in more than 50% of such punctures. The necessity for improved analgesia is emphasized by the fact, that at least 50% of patients experiencing substantial pain wished to receive concomitant medication in future punctures. Duration of the procedure was identified as sole independent predictive factor for patients’ pain intensity, while patients’ characteristics like gender, age and body-mass index (BMI) played only a minor role. As premedication with analgesics or anxiolytics may be associated with significant side-effects and an early identification of patients prone to experience severe pain is therefore difficult, further studies are warranted to establish an adequate approach in terms of pain control and feasibility in an ambulatory setting. In the meantime, daily physicians’ practice should be changed, as a pain-focused patient interview and presented indicators can be used in order to increase physicians’ awareness to procedure-related pain and augment their application of analgesics. 相似文献
26.
Case report: Fatal hepatic failure after aortic valve replacement and sevoflurane exposure 总被引:1,自引:0,他引:1
Andreas Lehmann Michael Neher Arndt-Holger Kiessling Frank Isgro Anette Koloska Joachim Boldt 《Journal canadien d'anesthésie》2007,54(11):917-921
PURPOSE: To report a case of lethal hepatotoxicity possibly caused by sevoflurane. CLINICAL FEATURES: A 76-yr-old woman with a history of four previous minor surgical procedures developed acute liver failure after general anesthesia with sevoflurane, sufentanil and propofol for aortic valve replacement. After an uneventful procedure the patient was extubated 4.5 hr after surgery. On the second postoperative day, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased. On the third postoperative day liver failure occurred, ALT peaked at 10504 UxL(-1) and AST at 15516 UxL(-1), and coagulopathy with an international normalized ratio of 4.6 developed. Liver transplantation was considered but rejected as a therapeutic option. The patient died three days after the operation in multiple organ failure triggered by hepatic failure. Other possible causes for liver failure were excluded. CONCLUSIONS: Sevoflurane hepatitis as a cause for liver failure may be implicated in this patient undergoing valve surgery. Unlike other halogenated anesthetic drugs, sevoflurane is not metabolized to hepatotoxic trifluoroacetyl proteins. However, compound A may react with proteins and may be transformed into antigenic material. We suggest that all halogenated anesthetics may be implicated with acute liver injury. 相似文献
27.
Using pupillometry and sympathetic skin responses we compared the changes in local and systemic autonomic function within
one week of a migraine attack. We investigated whether the measurement of the pupillary light reflex provides further information
on the pathophysiology of migraine.
Forty-two migraine patients and forty-two healthy age-matched controls were included. The parameters that were measured were
the amplitude of the pupillary light reflex, the pupil size at the beginning of the measurement, the latency, the velocity
of constriction and the velocity at the end of the dilatation.
The average pupil size was 6.43 mm in the migraine group and 6.7 mm in the control group (p < 0.01). Reduced velocity of
constriction and smaller amplitude of constriction in migraine patients within two days of an attack were signs of a parasympathetic
dysfunction (p < 0.05). The sympathetic skin response did not differ significantly between migraine sufferers and controls.
These findings indicate that both parasympathetic and sympathetic nerves supplying the eye are involved in migraine headache
presumably due to effects on the pericarotid sympathetic fibers and involvement of trigeminal-parasympathetic reflexes.
Received: 24 July 2001, Accepted: 16 July 2002
Correspondence to K. Schepelmann, M. D. 相似文献
28.
29.
Monocyte adhesion molecule expression in interstitial inflammation in patients with renal failure. 总被引:2,自引:0,他引:2
Elham Dadfar Joachim Lundahl Stefan H Jacobson 《Nephrology, dialysis, transplantation》2004,19(3):614-622
BACKGROUND: Patients with renal failure have an increased susceptibility to infections. We therefore studied the recruitment of monocytes and their expression of adhesion molecules CD11b and CD62L at the site of interstitial inflammation in patients with renal failure. Furthermore, we studied if the capacity of monocytes to up-regulate CD11b in interstitial inflammation was determined by the interstitial concentration of chemotactic factors. METHODS: Three intensities of interstitial inflammation (0, intermediate and intense) were established in skin blister chambers. Leukocyte count, CD11b/CD62L expression, monocyte chemotactic protein-1 (MCP-1) and blister activity in terms of CD11b mobilization were determined. RESULTS: The CD62L expression on monocytes was lower in the peripheral circulation in patients with renal failure compared with healthy subjects (P<0.005 and P<0.001). At the site of interstitial inflammation patients had a higher expression of CD62L (intermediate, P<0.05; intense, P<0.005). Furthermore, monocytes from patients had an impaired capacity to mobilize CD11b both in the peripheral circulation (P<0.005) and at the intermediate and intense sites of interstitial inflammation (P<0.005 and P<0.001, respectively) compared with cells collected from healthy subjects. We incubated monocytes in blister exudates, in order to explore whether this phenomenon is caused by cellular factors and/or to the interstitial concentration of chemotactic mediators. The expression of CD11b on monocytes from healthy blood donors incubated in blister exudates from either patients or healthy subjects in vitro was similar. The interstitial concentration of MCP-1 at the site of intermediate inflammation was significantly lower in patients with renal failure compared with the corresponding blister exudate collected from healthy subjects (P<0.05), but no differences were observed at the site of intense inflammation. Furthermore, neutralizing the action of MCP-1 in blister exudates with monoclonal antibodies did not have any impact on monocyte CD11b expression following incubation in blister exudates. CONCLUSION: These studies indicate that the impaired capacity of monocytes to mobilize CD11b at the site of inflammation in patients with renal failure is more dependent on constitutive cellular factors than the concentration of CD11b mobilizing factors in the interstitium. 相似文献
30.
Normative values of bone parameters of children and adolescents using digital computer-assisted radiogrammetry (DXR). 总被引:2,自引:0,他引:2
Ansgar Malich Martin G Freesmeyer Hans-Joachim Mentzel Dieter Sauner Joachim Boettcher Alexander Petrovitch Werner Behrendt Werner A Kaiser 《Journal of clinical densitometry》2003,6(2):103-111
PURPOSE: To verify whether estimation of bone mineral density (BMD) using digital X-ray radiogrammetry (DXR) is possible on children and to determine normative values of both such a DXR-BMD estimate and a corresponding metacarpal index (DXR-MCI) on. PATIENTS AND METHODS: In retrospect, X-rays were selected of the hands of 200 healthy Caucasian children (120 boys and 80 girls, aged 4-18 yr). The involved children were selected among a larger group of children submitted to the surgical department of our institute for evaluation of a suspected fracture after an occurred trauma. All children with a verified fracture or a chronic bone-related disease, including bone age retardation or acceleration, were excluded from the study. Furthermore, only conventional X-rays with the same film and capture parameters were included. The images were scanned and analyzed using the Pronosco X-posure system V.2 (Sectra Pronosco, Denmark). DXR-BMD, DXR-MCI, and a porosity index (DXR-PI) were automatically calculated using the midshafts of the metacarpals II-IV. Mean values of DXR-BMD and DXR-MCI were calculated separately for girls and boys in 2-yr intervals. RESULTS: In the present study the system has been demonstrated to be capable of calculating DXR-BMD from conventional X-rays of the hand from children down to approx 6 yr of age. This ability depended somewhat on the diameter and the length of the involved metacarpals. The success rate was higher for large bones than for small bones. The system succeeded in analyzing the images of 110 boys and 68 girls. Values of DXR-BMD were observed to increase with age from 0.40 g/cm2 to 0.62 g/cm2 in the male group and from 0.39 g/cm2 to 0.54 g/cm2 in the female group. Girls aged 11-12 yr had a higher DXR-BMD than did boys, corresponding to the earlier entry to puberty of girls. Standard deviations (SDs) reached values of up to 0.05 g/cm2. DXR-MCI increased with age from 0.36 to 0.47 for boys and from 0.34 to 0.49 for girls with a maximum SD of 0.06. The correlation between DXR-BMD and age was r=0.83 and r=0.84 for boys and girls, respectively. The corresponding correlations for DXR-MCI was lower, with observed correlations of r=0.63 (boys) and r=0.68 (girls), respectively, with p<0.01 in all cases. The DXR-PI did not reveal a significant correlation to age (r=-0.31 and r=0.04. respectively) and showed SDs marginally higher than the calculated mean values. CONCLUSION: The newly available DXR-methodology seems to offer the ability to determine DXR-BMD and DXR-MCI in children starting with a bone age of 6. This possibility may be of special relevance for children suffering from chronic bone diseases that require repeated X-rays of the hand (e.g. to determine bone age). The acquired normative data suggest that the measurements are of clinical value owing to low age-dependent variability (SDs) relative to an observed high increase with age. The clinical value of the porosity index (DXR-PI) remains uncertain and is limited owing to a high inter-individual variability. 相似文献