首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   489篇
  免费   22篇
  国内免费   9篇
儿科学   33篇
妇产科学   6篇
基础医学   31篇
口腔科学   10篇
临床医学   36篇
内科学   74篇
皮肤病学   8篇
神经病学   5篇
特种医学   75篇
外科学   170篇
综合类   8篇
预防医学   10篇
眼科学   3篇
药学   16篇
肿瘤学   35篇
  2022年   3篇
  2021年   4篇
  2020年   7篇
  2019年   15篇
  2018年   8篇
  2017年   17篇
  2016年   9篇
  2015年   17篇
  2014年   18篇
  2013年   18篇
  2012年   31篇
  2011年   42篇
  2010年   34篇
  2009年   27篇
  2008年   18篇
  2007年   14篇
  2006年   21篇
  2005年   18篇
  2004年   11篇
  2003年   8篇
  2002年   2篇
  2001年   6篇
  2000年   2篇
  1999年   4篇
  1998年   21篇
  1997年   18篇
  1996年   20篇
  1995年   14篇
  1994年   9篇
  1993年   6篇
  1991年   1篇
  1990年   3篇
  1989年   6篇
  1988年   11篇
  1987年   6篇
  1986年   6篇
  1985年   3篇
  1984年   4篇
  1982年   4篇
  1981年   5篇
  1980年   4篇
  1979年   4篇
  1978年   1篇
  1977年   5篇
  1976年   6篇
  1975年   1篇
  1948年   2篇
  1932年   1篇
  1925年   1篇
  1924年   1篇
排序方式: 共有520条查询结果,搜索用时 15 毫秒
51.
AimTo present foot salvage for osteosarcoma of the navicular bone with en bloc resection and reconstruction using bone allograft and talus-cuneiform arthrodesis.Patient and surgical techniqueA 20 year-old male with a history of osteosarcoma of the distal femur presented to our department 5 years later with a metastatic lesion of the navicular bone of the contralateral foot. The patient received 4 cycles of neo-adjuvant chemotherapy with satisfactory response. Tumor shrinkage allowed en bloc excision of the navicular bone with clear margins. Reconstruction was done using a tricortical allograft and talus-allograft-cuneiform arthrodesis, secured with a mini-fracture plate (Synthes). Weight bearing protection was advised for 2 months and partial weight bearing for another 4 months. Patient received 4 cycles of adjuvant chemotherapy.ResultsThree years postoperatively, the patient was free of local recurrence or distant metastasis. There were no signs of allograft resorption, fracture or non union. The patient was asymptomatic and full weight bearing. Ankle and subtalar joint motion was within normal limits.ConclusionFoot salvage after excision of osteosarcoma of the navicular bone could be possible if en bloc resection of the lesion could be performed. Talus-cuneiform fusion with allograft interposition is a viable reconstructive option.  相似文献   
52.
Koller  CA; LoBuglio  AF 《Blood》1981,58(2):293-299
Human monocytes respond to opsonized microorganisms with a "metabolic burst" composed of an increase in oxygen consumption, an increase in hexose monophosphate shunt (HMPS) activity, and the generation of reactive oxygen species (ROS). We investigated the role of the metabolic burst in antibody-dependent cell-mediated cytotoxicity (ADCC) by human monocytes toward anti-D coated erythrocyte target cells because recent studies suggested a role for oxygen-dependent bactericidal mechanisms in ADCC. In normal monocytes, we found that ADCC was nearly halved under hypoxic conditions. Several agents known to impair activation of the burst, such as vincristine, cation chelators, and a sulfhydryl reagent, all decreased cytotoxicity if added before initiation of contact between target and effector cells. Cytotoxicity was inhibited by 2-deoxyglucose but not fluoride, suggesting a nonglycolytic role for glucose in ADCC, perhaps in the HMPS pathway. Although these data suggested a role for the metabolic burst in ADCC, scavengers of ROS did not impair cytotoxicity, and monocytes from chronic granulomatous disease (CGD) patients who had a defective metabolic burst had normal levels of ADCC. We conclude that ADCC toward anti-D coated erythrocyte target cells was the result of at least two independent but closely related cytotoxic pathways. Although one of these pathways appeared to involve the metabolic burst, the potentially cytotoxic reactive oxygen species did not appear to play a role in this system.  相似文献   
53.
54.
Recombinant human (rh) interleukin-3 (IL-3) stimulated the proliferation and differentiation of erythroid, granulocyte, macrophage, eosinophil (Eo), and mixed colonies as well as megakaryocytes from human bone marrow cells. rh IL-3 was a weaker stimulus than rh granulocyte-macrophage colony-stimulating factor (GM- CSF) for day 14 myeloid cell colonies. At day 7 of incubation, rh IL-3 stimulated a few G, M, and Eo clusters but no colonies. This loss of responsiveness of myeloid cells to rh IL-3 was accentuated with further differentiation of the cells. rh IL-3 stimulated very few or no clones after five-day incubation with enriched promyelocytes and myelocytes, whereas rh GM-CSF was an efficient stimulus. Responsiveness to rh IL-3 was completely lost in postmitotic mature neutrophils. Incubation of these cells with rh IL-3 did not result in enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells or superoxide anion production after stimulation with formyl-methyl-leucyl-phenylalanine (FMLP), although they could be stimulated by rh GM-CSF. In addition, preincubation of neutrophils with different concentrations of rh IL-3 failed to increase or decrease their response to rh GM-CSF. In contrast to neutrophils, mature Eos could be stimulated by rh IL-3 to kill antibody-coated tumor cells. These results show that cells of the neutrophilic myeloid series lose their responsiveness to h IL-3 as they differentiate and suggest that although h IL-3 may be an important therapeutic agent to use for hematopoietic regeneration in vivo, the lack of stimulation of mature neutrophil function makes it an unlikely sole candidate as adjunct therapy for treatment of infectious diseases.  相似文献   
55.

Background

In 2001, two hexavalent vaccines were licensed in Italy (Hexavac®, Infanrix Hexa®), and since 2002 were extensively used for primary immunization in the first year of life (at 3, 5, 11/12 months of age). In 2005, the market authorization of Hexavac® was precautionary suspended by EMEA, because of doubts on long-term protection against hepatitis B virus. The objectives of this study were to evaluate the persistence of antibodies to anti-HBs, in children in the third year of life, and to investigate the response to a booster dose of hepatitis B vaccine.

Methods

Participant children were enrolled concomitantly with the offering of anti-polio booster dose, in the third year of life. Anti-HBs titers were determined on capillary blood samples. A booster dose of hepatitis B vaccine was administered to children with anti-HBs titers < 10 mIU/ml, with the monovalent precursor product of the previously received hexavalent vaccine. HBsAb titers were tested again one month after the booster.

Results

Sera from 113 children previously vaccinated with Hexavac®, and from 124 vaccinated with Infanrix Hexa® were tested for anti-HBs. Titers were ≥ 10 mIU/ml in 69% and 96% (p < 0,0001) respectively. The proportion of children with titers ≥ 100 mIU/ml did also significantly differ among groups (27% and 78%; p < 0,0001). Post-booster, 93% of children achieved titers ≥ 10 mIU/ml, with no significant difference by vaccine group.

Discussion

Fifteen months after third dose administration, a significant difference in anti-HBs titers was noted in the two vaccine groups considered. Monovalent hepatitis B vaccine administration in 3-year old children induced a proper booster response, confirming that immunologic memory persists in children with anti-HBs titers < 10 mIU/ml. However, long-term persistence of HBV protection after hexavalent vaccines administration should be further evaluated over time.  相似文献   
56.
Gombart  AF; Morosetti  R; Miller  CW; Said  JW; Koeffler  HP 《Blood》1995,86(4):1534-1539
The tumor suppressor genes p16INK4A and p15INK4B map to the 9p21 chromosomal locus and are either homozygously deleted or mutated in a wide range of human cancer cell lines and tumors. Although chromosome 9 abnormalities have been described in non-Hodgkin's lymphomas (NHLs), to date, the mutational status of these genes has not been determined for these malignancies. A total of five cell lines and 75 NHLs were examined for homozygous deletions or point mutations in the coding regions of both the p15 and p16 genes using Southern blot and/or polymerase chain reaction-single-strand conformation polymorphism analyses. Homozygous deletions of either the p16 gene or both the p15 and p16 genes were observed in one diffuse large B-cell lymphoma cell line and two uncultured lymphomas consisting of one large B-cell and one mixed T-cell lymphoma. In contrast, point mutations were not detected in either the cell lines or lymphomas. These results indicate that the rate of alterations in the p15 and p16 genes is low for lymphomas, but loss of p16 and/or p15 may be involved in the development of some lymphomas.  相似文献   
57.

Purposes

Our aim was to evaluate the anal sphincter function following cystectomy with urinary diversion of Mainz pouch II.

Methods

Seventy-six patients were involved in our survey, and the cohort was for two groups divided. The first group was a retrospective review of 40 patients with examination of the state of continence. Comparative examinations on anal sphincter function and the quality of life survey were carried out. The second group consisting of 15 patients underwent a prospective investigation including rectal manometry in both the pre- and postoperative periods. Measurements of resting anal sphincter pressure (RASP), maximal anal closing pressure (MACP) and the function of the recto anal inhibitions reflex were taken.

Results

In the first part of our investigation, 80% of the patients were considered as continent. There were no significant differences observed between RASP values in the cases of continent as well as of incontinent patients (79.2?±?2 vs. 73.6?±?68.4?mmHg, p?=?0?C53); however, the MACP values of the continent patients were significantly higher (204.3?±?22.8 vs. 117.3?±?14?mmHg, p?=?0.001). In the course of the second experiment, both the RASP (86.3?±?18.7 vs. 76.1?±?13.9?mmHg p?=?0.0049) and the MACP (232.2?±?53.8 vs. 194.1?±?74.5?mmHg, p?=?0.0054) were detected as decreasing in the case of the incontinent group.

Conclusions

A decrease in rectal sphincter function is responsible for incontinence following Mainz pouch type II diversion, and this dysfunction can be correlated with the surgery. Ureterosigmoideostomy is therefore considered as a useful method of urinary diversion only in selected cases with proven good sphincter function.  相似文献   
58.
This study is a randomized prospective study comparing two fracture fixation implants, the extramedullary sliding hip screw (SHS) and the dual lag screw cephalomedullary nail, in the treatment of intertrochanteric femoral fractures in the elderly. One hundred and sixty-five patients with low-energy intertrochanteric fractures, classified as AO/OTA 31A, were prospectively included during a 2-year period (2005–2006). Patients were randomized into two groups: group A included 79 hip fractures managed with sliding hip screws and group B included 86 fractures treated with cephalomedullary nails. Delay to surgery, duration of surgery, time of fluoroscopy, total hospital stay, implant-related complications, transfusion requirements, re-operation details, functional recovery, and mortality were recorded. The mean follow-up was 36 months (24–56 months). The mean surgical time was statistically significantly shorter and fluoroscopy time longer for the group B. No intraoperative femoral shaft fractures occurred. There was no statistically significant difference in the functional recovery score, reoperation, and mortality rates between the 2 groups. A new type of complication, the so-called Z-effect phenomenon, was noticed in the cephalomedullary nail group. There are no statistically significant differences between the two techniques in terms of type and rate of complications, functional outcome, reoperation and mortality rates when comparing the SHS and the cephalomedullary nail for low-energy AO/OTA 31A intertrochanteric fractures. Our data do not support recommendations for the use of one implant over the other.  相似文献   
59.
60.
Reactions to contrast media: testing the CNS hypothesis   总被引:1,自引:0,他引:1  
Lalli  AF; Greenstreet  R 《Radiology》1981,138(1):47
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号