全文获取类型
收费全文 | 1884篇 |
免费 | 106篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 61篇 |
妇产科学 | 11篇 |
基础医学 | 254篇 |
口腔科学 | 28篇 |
临床医学 | 183篇 |
内科学 | 506篇 |
皮肤病学 | 47篇 |
神经病学 | 172篇 |
特种医学 | 256篇 |
外科学 | 278篇 |
综合类 | 28篇 |
预防医学 | 33篇 |
眼科学 | 27篇 |
药学 | 69篇 |
中国医学 | 7篇 |
肿瘤学 | 93篇 |
出版年
2022年 | 8篇 |
2021年 | 21篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 29篇 |
2017年 | 16篇 |
2016年 | 20篇 |
2015年 | 43篇 |
2014年 | 44篇 |
2013年 | 69篇 |
2012年 | 64篇 |
2011年 | 65篇 |
2010年 | 58篇 |
2009年 | 48篇 |
2008年 | 58篇 |
2007年 | 98篇 |
2006年 | 40篇 |
2005年 | 55篇 |
2004年 | 70篇 |
2003年 | 47篇 |
2002年 | 35篇 |
2001年 | 37篇 |
2000年 | 36篇 |
1999年 | 32篇 |
1998年 | 66篇 |
1997年 | 46篇 |
1996年 | 62篇 |
1995年 | 49篇 |
1994年 | 49篇 |
1993年 | 55篇 |
1992年 | 18篇 |
1991年 | 34篇 |
1990年 | 40篇 |
1989年 | 48篇 |
1988年 | 53篇 |
1987年 | 56篇 |
1986年 | 48篇 |
1985年 | 44篇 |
1984年 | 33篇 |
1983年 | 23篇 |
1982年 | 21篇 |
1981年 | 35篇 |
1980年 | 25篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1977年 | 23篇 |
1976年 | 8篇 |
1975年 | 15篇 |
1939年 | 7篇 |
1906年 | 6篇 |
排序方式: 共有2058条查询结果,搜索用时 15 毫秒
31.
FJ Cowan JT Warner FD Dunstan WD Evans JW Gregory HR Jenkins 《Archives of disease in childhood》1997,76(4):325-329
The prevalence of osteopenia in children with inflammatory bowel disease (IBD) is unknown. The effect of nutritional state, disease activity, and steroid therapy on bone mineral content (BMC) of whole body, lumbar spine, and left femoral neck measured by dual energy x ray absorptiometry in 32 children with IBD was assessed by comparison with 58 healthy local school children. Using the control data, a predicted BMC was calculated taking into account bone area, age, height, weight, and pubertal stage. The measured BMC in children with IBD was expressed as a percentage of this predicted value (% BMC). Mean (SD) % BMC was significantly reduced for the whole body and left femoral neck in the children with IBD (97.0 (4.5)% and 93.1 (12.0)% respectively, p < 0.05). Of the children with IBD, 41% had a % BMC less than 1 SD below the mean for the whole body and 47% at the femoral neck. Reduction in % BMC was associated with steroid usage but not with the magnitude of steroid dose, disease activity, or biochemical markers of bone metabolism. In conclusion, osteopenia is relatively common in childhood IBD and may be partly related to the previous use of steroids. 相似文献
32.
BA Evans IA Hughes CL Bevan MN Patterson JW Gregory 《Archives of disease in childhood》1997,76(6):529-531
The androgen insensitivity syndrome is a heterogeneous disorder with a wide spectrum of phenotypic abnormalities, ranging from complete female to ambiguous forms that more closely resemble males. The primary abnormality is a defective androgen receptor protein due to a mutation of the androgen receptor gene. This prevents normal androgen action and thus leads to impaired virilisation. A point mutation of the androgen receptor gene affecting two siblings with partial androgen insensitivity syndrome is described. One had cliteromegaly and labial fusion and was raised as a girl, whereas the other sibling had micropenis and penoscrotal hypospadias and was raised as a boy. Both were shown to have the arginine 840 to cysteine mutation. The phenotypic variation in this family is thus dependent on factors other than abnormalities of the androgen receptor gene alone. 相似文献
33.
Immunobiology of T helper cells and antigen-presenting cells in autoimmune thrombocytopenic purpura (ITP) 总被引:1,自引:0,他引:1
JW Semple 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(S424):41-45
Autoimmune thrombocytopenic purpura (AITP) is a bleeding disease in which autoantibodies are directed against the individual's own platelets, resulting in enhanced Fc-mediated platelet destruction by macrophages in the reticuloendothelial system. Most research in AITP has focused on characterization of the autoantibodies, while little has been devoted to the cellular immune mechanisms leading to autoantibody production. This report summarizes the current state of the literature and argues that enhanced T helper cell/antigen-presenting cell interactions in patients with AITP are the primary stimulus for the development of antiplatelet autoantibody production. Understanding these events is important for eventually identifying disease-initiating platelet autoantigens and ultimately developing specific immunotherapies for AITP. 相似文献
34.
35.
Kenichi Satoh Mami Chikuda Ayako Ohashi Miho Kumagai Akiyoshi Kuji Shigeharu Joh 《Journal of clinical monitoring and computing》2016,30(4):423-428
Measurement of end-tidal carbon dioxide (PETCO2) is useful because of its noninvasiveness, continuity, and response time when sudden changes in ventilation occur during inhalation sedation. We compared the accuracy of PETCO2 using a nasal mask and nasal cannula with the accuracy of transcutaneous carbon dioxide (TC-CO2) and determined which method is more useful during inhalation sedation in volunteers. We used a modified nasal mask (MNM) and modified nasal cannula (MNC) for measurement of PETCO2. The capnometer measured PETCO2 in the gas expired from the nasal cavity by means of two devices. The volunteers received supplemental O2 by means of each device at a flow rate of 6 L/min. After the volunteers lay quietly for 5 min with a supply of 100 % O2, they received supplemental N2O by means of each device at concentrations of 10, 20, and 25 % for 5 min and 30 % for 25 min. The correlation coefficient was poorer in the MNM than in the MNC, and the mean difference between TC-CO2 and PETCO2 in the MNM was greater than that in the MNC. The difference between the TC-CO2 and PETCO2 ranged from 3 to 6 mmHg in the MNM and from 2 to 5 mmHg in the MNC. The difference between two variables against the TC-CO2 and the CO2 waveforms obtained by means of the two devices were within the clinically acceptable range. Our two devices can provide continuous monitoring of PETCO2 with a supply of N2O/O2 in patients undergoing inhalation sedation. 相似文献
36.
Suman Kundu Lennart C Karssen A Cecile JW Janssens 《European journal of human genetics : EJHG》2012,20(12):1270-1274
Various modeling methods have been proposed to estimate the potential predictive ability of polygenic risk variants that predispose to various common diseases. However, it is unknown whether differences between them affect their conclusions on predictive ability. We reviewed input parameters, assumptions and output of the five most common methods and compared their estimates of the area under the receiver operating characteristic (ROC) curve (AUC) using hypothetical data representing effect sizes and frequencies of genetic variants, population disease risk and number of variants. To assess the accuracy of the estimated AUCs, we aimed to reproduce the AUCs of published empirical studies. All methods assumed that the combined effect of genetic variants on disease risk followed a multiplicative risk model of independent genetic effects, but they either assumed per allele, per genotype or dominant/recessive effects for the genetic variants. Modeling strategy and input parameters differed. Methods used simulation analysis or analytical formulas with effect sizes quantified by odds ratios (ORs) or relative risks. Estimated AUC values were similar for lower ORs (<1.2). When AUCs were larger (>0.7) due to variants with strong effects, differences in estimated AUCs between methods increased. The simulation methods accurately reproduced the AUC values of empirical studies, but the analytical methods did not. We conclude that despite differences in input parameters, the modeling methods estimate similar AUC for realistic values of the ORs. When one or more variants have stronger effects and AUC values are higher, the simulation methods tend to be more accurate. 相似文献
37.
June-Bum Kim Ji-Hyun Choi Ji-Hye Kim Hyang-Joon Park Jae-Seung Lee Ok-Ja Joh Kye Yong Song 《ANNALS OF DERMATOLOGY》2010,22(4):472-477
Primary cutaneous mucinous carcinoma is a rare malignant tumor that originates from the deepest portion of the eccrine sweat duct. Common sites of involvement are the face and scalp. Biopsy shows dermal epithelial cell islands embedded in mucin pools separated by fibrous septae. It is difficult to differentiate this tumor histologically from metastatic adenocarcinoma. Recurrence after excision is common but metastases are rare. We report a primary cutaneous mucinous carcinoma with neuroendocrine differentiation on the right cheek of a 63-year-old man. 相似文献
38.
Masahide?EbiEmail author Shoko?Nakagawa Yoshiharu?Yamaguchi Yasuhiro?Tamura Shinya?Izawa Yasutaka?Hijikata Takaya?Shimura Yasushi?Funaki Naotaka?Ogasawara Makoto?Sasaki Takashi?Joh Kunio?Kasugai 《International journal of colorectal disease》2018,33(12):1703-1708
Background
Endoscopic resection is recommended for rectal neuroendocrine tumors <?1 cm in diameter; the three techniques (mucosal resection, submucosal dissection, and mucosal resection with variceal ligation device) of endoscopic resection of neuroendocrine tumor were reported; however, the optimal endoscopic technique remains unclear.Purpose
We compared the efficacy and safety of three endoscopic rectal neuroendocrine tumor resection methods.Methods
We retrospectively enrolled 52 patients with rectal neuroendocrine tumors treated by endoscopy at Aichi Medical University Hospital and Nagoya City University Hospital between May 2003 and June 2017. We compared clinical outcomes in three groups based on the endoscopic treatment method.Results
Fifty-two patients underwent endoscopic rectal neuroendocrine tumor treatment (mucosal resection, 14; submucosal dissection, 19; mucosal resection with an endoscopic variceal ligation device, 19). In the endoscopic mucosal resection, submucosal dissection, and mucosal resection with variceal ligation device groups, R0 resection occurred in 50.0, 94.7, and 89.5%, respectively (mucosal resection vs. mucosal resection with variceal ligation device, p <?0.05; mucosal resection vs. submucosal dissection, p <?0.01), while the median procedure times were 6.5, 43, and 6.0 min, respectively (submucosal dissection vs. mucosal resection with variceal ligation device procedure times, p?<?0.01; mucosal resection vs. submucosal resection procedure times, p <?0.01). Postoperative bleeding occurred after endoscopic mucosal resection (1/14) and endoscopic submucosal dissection (4/19), but not after endoscopic mucosal resection with a ligation device.Conclusion
Endoscopic mucosal resection with an endoscopic variceal ligation device was a safe, effective treatment for rectal neuroendocrine tumors.39.
Ran-hui Cha Joon-Sung Joh Ina Jeong Ji Yeon Lee Hyoung-Shik Shin Gayeon Kim Yeonjae Kim Critical Care Team of National Medical Center 《Journal of Korean medical science》2015,30(12):1807-1814
Some cases of Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) infection presented renal function impairment after the first MERS-CoV patient died of progressive respiratory and renal failure. Thus, MERS-CoV may include kidney tropism. However, reports about the natural courses of MERS-CoV infection in terms of renal complications are scarce. We examined 30 MERS-CoV patients admitted to National Medical Center, Korea. We conducted a retrospective analysis of the serum creatinine (SCr), estimated glomerular filtration rate (eGFR), urine dipstick tests, urinary protein quantitation (ACR or PCR), and other clinical parameters in all patients. Two consecutive results of more than trace (or 1+) of albumin and blood on dipstick test occurred in 18 (60%) (12 [40%]) and 22 (73.3%) (19 [63.3%]) patients, respectively. Fifteen (50.0%) patients showed a random urine ACR or PCR more than 100 mg/g Cr. Eight (26.7%) patients showed acute kidney injury (AKI), and the mean and median durations to the occurrence of AKI from symptom onset were 18 and 16 days, respectively. Old age was associated with a higher occurrence of AKI in the univariate analysis (HR [95% CI]: 1.069 [1.013-1.128], P = 0.016) and remained a significant predictor of the occurrence of AKI after adjustment for comorbidities and the application of a mechanical ventilator. Diabetes, AKI, and the application of a continuous renal replacement therapy (CRRT) were risk factors for mortality in the univariate analysis (HR [95% CI]: diabetes; 10.133 [1.692-60.697], AKI; 12.744 [1.418-114.565], CRRT; 10.254 [1.626-64.666], respectively). Here, we report renal complications and their prognosis in 30 Korean patients with MERS-CoV. 相似文献
40.
We have identified and molecularly characterized a novel deletion in the beta-globin gene cluster that increases fetal hemoglobin (HbF) synthesis in a 24-year-old Laotian man who is heterozygous for this mutation. The patient is asymptomatic with a mild anemia, hypochromia, and microcytosis (Ht = 39%, MCH = 22.8 pg, MCV = 71 fl), normal levels of HbA2 (3.0%) and 11.5% HbF (G gamma A gamma ratio 60 to 40), with heterocellular distribution (52% F cells). Extensive restriction endonuclease mapping defined the 5' breakpoint within the IVS II of the delta-globin gene, between positions 775 to 781 very similar to the 5' breakpoint of the Sicilian delta beta-thalassemia. However, the 3' breakpoint was localized between two Pst I sites 4.7 kb 3' of the beta- globin gene, thus ending about 0.7 kb upstream from the 3' breakpoint of the Sicilian delta beta-thalassemia. This results in a 12.5 kb deletion of DNA. It is of interest that the 5' breakpoint of the deletion residues within an AT-rich region which has been proposed as a specific recognition signal for recombination events, while the 3' breakpoint lies within a cluster of L1 repetitive sequences (formerly known as Kpn I family repeats). The presence of the 3' breakpoints of several other deletions within this region of L1 repeats also suggests that such sequences might serve as hot spots for recombination and eventually lead to thalassemia deletions. The similarity of the 5' and 3' breakpoints of these delta beta-thalassemias underscores the putative regulatory role of the deleted and juxtaposed sequences on the expression of the gamma-globin genes in adult life. 相似文献