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   13678篇
  免费   679篇
  国内免费   122篇
耳鼻咽喉   352篇
儿科学   677篇
妇产科学   599篇
基础医学   1022篇
口腔科学   440篇
临床医学   1103篇
内科学   3444篇
皮肤病学   211篇
神经病学   828篇
特种医学   590篇
外科学   3215篇
综合类   191篇
一般理论   1篇
预防医学   325篇
眼科学   464篇
药学   492篇
中国医学   26篇
肿瘤学   499篇
  2024年   11篇
  2023年   109篇
  2022年   205篇
  2021年   402篇
  2020年   261篇
  2019年   321篇
  2018年   403篇
  2017年   329篇
  2016年   565篇
  2015年   635篇
  2014年   695篇
  2013年   846篇
  2012年   1087篇
  2011年   1000篇
  2010年   624篇
  2009年   529篇
  2008年   916篇
  2007年   1073篇
  2006年   981篇
  2005年   970篇
  2004年   848篇
  2003年   633篇
  2002年   561篇
  2001年   98篇
  2000年   58篇
  1999年   65篇
  1998年   66篇
  1997年   45篇
  1996年   33篇
  1995年   27篇
  1994年   18篇
  1993年   10篇
  1992年   11篇
  1991年   10篇
  1990年   12篇
  1989年   4篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1975年   1篇
  1973年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Kara IH  Yilmaz ME  Suner A  Kadiroglu AK  Isikoglu B 《Vaccine》2004,22(29-30):3963-3967
The hepatitis B virus (HBV) vaccination never lose its importance; however, we did not get immune response with vaccination in some cases at the hemodialysis (HD) units. In this research, our aim was to evaluate antibody responses that constitute with natural ways and vaccination against HBV infection in chronic HD patients. In this retrospective cohort study (between 1999 February and 2001 December), 34 patients, 19 males and 15 females that were at the HD program, were enrolled. Patients were divided into two groups: group A, vaccination group (n = 15); and group B, anti-HBc IgG (+) cases (n = 19). We injected 40 microg of recombinant HBV vaccine into the deltoid muscle at 0, 1, 2, and 6 months. The anti-HBs levels, over 10 mIU/mL, were accepted for enough immunization. In group A, after vaccination 12 of 15 (80%) patients had seroconversion but later, in five of 12 (33.3%) patients, HBs-antibody became negative and in seven of 12 (46.7%) patients the positivity of HBs-antibody continued. However, in group B, 16 of 19 (66.7%) immune patients who faced HBV infection, it was established that antibody response continued (P > 0.05). The patients in group A who had anti-HCV negativity and serum albumin levels >/=3.5g/dL (7/0; P < 0.05) had too much antibody response against the vaccine. The difference of our research was that patients under 49 years old, patients who did not respond to HBV vaccine, were proportionally higher as compared to those from other researches. In conclusion, it was realized that the immune response of the HBV vaccine was low in the HD patients and it was affected by several factors such as gender, anti-HCV positivity and nutritional status. But, in spite of getting all universal precautions, still to face with new cases emphasizes the importance of the vaccination.  相似文献   
992.
Leukemic infiltration of the gingiva is most commonly reported to be associated with monocytic subtypes of acute myeloblastic leukemia (AML) but rarely with myelodysplastic syndromes (MDS). Here we report a case of CD56+ chronic myelomonocytic leukemia (CMML) who developed gingival involvement simultaneously when the leukocyte count elevated. At that time no increase in peripheral or bone marrow blasts were observed. Gingival hypertrophy regressed with the treatment of hydroxyurea. Three months later, bone marrow blast count elevated and the patient was treated with two courses of AML-like regimen and then one course of consolidation therapy. The patient is in complete hematological remission for one and a half years. Similar to other extramedullary involvements, gingival hypertrophy in CMML can be a harbinger of the disease entering a more aggressive phase requiring systemic chemotherapy.  相似文献   
993.
BACKGROUND: An increased susceptibility to infections has been observed in some patients with phenylketonuria (PKU), which is not well known whether it is due to alterations of plasma essential amino acid concentrations or to some other factors. OBJECTIVE: This study is designed to establish B cell and T cell functions in 44 children with classical PKU and tetrahydrobiopterin (BH4) deficiencies and the effects of too high plasma phenylalanine (PA) concentrations (16.53 to 30.54 mg/dL) on the same parameters. DESIGN: B and T cell functions of 33 children with classical PKU (divided into two groups based on fasting mean plasma PA concentrations: Group-I = 20.9 +/- 3.7 mg/dL, Group-II = 3.8 +/- 1.02 mg/dL), and 11 children with BH4 deficiencies (Group III) were studied. The results were compared between the groups and referenced with previously reported values from healthy controls. RESULT: Delayed type skin hypersensitivity responses to purified protein derivative (PPD) in Group I and phytohaemagglutinin (PHA) in Group I, III were lower than the other groups and healthy controls. Plasma IgG and IgM concentrations of Group I was lower than the reference values. Although mean serum zinc and iron levels of all patients were lower than published values of healthy children, zinc and iron deficiencies in Group I, III were much more prominent as compared to Group II. CONCLUSION: The somewhat low plasma IgG concentrations in Group I may be related to the very high plasma PA levels, however the role of zinc deficiency as a causal factor can not be ruled out. BH4 metabolism defects do not appear to affect the same parameters. Impaired delayed skin hypersensitivity responses in Group I and III can be explained by severe serum zinc deficiency. In the light of this study, we conclude that in order to establish a causal relationship between PKU and immune functions, further studies need to be conducted after the correction of micro-nutrient status of such children.  相似文献   
994.
995.
Hospital records of 1160 children 相似文献   
996.
We aimed to determine the value of maternal erythrocyte malondialdehyde levels in the prediction of preeclampsia. 110 healthy women were included in this prospective study. Maternal erythrocyte malondialdehyde levels were measured at each trimester of pregnancy (10-14, 20-25 and 30-35 gestational weeks). On follow-up, patients were assigned to two groups as normotensive women and preeclamptic patients. Preeclampsia had developed in eight (8.9%) of the 90 pregnant women who completed the study. Preeclamptic patients were diagnosed between 36 and 39 gestational weeks (36.8 +/- 1.0 weeks). Malondialdehyde levels of preeclamptic patients increased significantly in the third trimester (p < 0.05), while there was no difference between values of malondialdehyde in the first and second trimester. Malondialdehyde levels were significantly higher in the patients who developed preeclampsia than in those who did not in the third trimester (p < 0.05). With the use of the receiver operating characteristics (ROC) 35.98 nmol malondialdehyde/gm hemoglobin was found to be a cut-off value predictive for the development of preeclampsia in the third trimester. However, cut-off values in the first and second trimesters could not be found. The sensitivity, specificity, positive and negative predictive values were 89, 75, 29 and 98%, respectively. Preeclampsia risk was found to increase nearly 24 times in values above 35.98 nmol malondialdehyde/ gm hemoglobin. Our results showed that maternal erythrocyte malondialdehyde could predict patients within a few weeks prior to onset of clinical symptoms of preeclampsia in the third trimester. There is no evidence of enhanced early lipid peroxidation in pregnancies with late onset preeclampsia.  相似文献   
997.
PURPOSE: To compare the survival and prognostic factors of patients with synchronous primary ovarian and endometrial cancers, and endometrial cancers metastatic to the ovaries. PATIENTS AND METHODS: Fifty-three patients with synchronous primary ovarian and endometrial cancer and 64 patients with endometrial cancer metastatic to the ovaries were evaluated. RESULTS: Mean follow-up time was 47.2 months (18-170 months). There was no statistical difference in age, gravidity and parity between the two groups. Abnormal vaginal bleeding was the most common symptom in both groups. All patients were subjected to a surgical staging procedure. Overall survival of the synchronous group was significantly higher than that of the metastatic group (98 +/- 12 vs 59 +/- 6 months; p = 0.048). The significant prognostic factors for synchronous cancers after multivariate analysis were age, stage of ovarian cancer, grade of endometrial cancer, and adjuvant therapy status. CONCLUSION: Patients with synchronous ovarian and endometrial cancers appear to have a good prognosis and should undergo primary surgical staging since the stage of tumors is a significant prognostic factor.  相似文献   
998.
OBJECTIVE: To report the birth of a healthy female infant from a father with nonmosaic Klinefelter syndrome (KS) and document the experience of men with KS undergoing assisted conception. DESIGN: Retrospective. SETTING: Private IVF center. PATIENT(S): Twelve couples with male factor infertility due to Klinefelter syndrome undergoing assisted reproduction treatment. INTERVENTION(S): Controlled ovarian hyperstimulation, testicular sperm extraction, intracytoplasmic sperm injection (ICSI), round spermatid injection (ROSI), and preimplantation genetic diagnosis. MAIN OUTCOME MEASURE(S): Testicular sperm retrieval rate, fertilization rate, and pregnancy outcome. RESULT(S): There was a sufficient amount of motile sperm for injection into mature oocytes in 6 of the 11 testicular biopsies (54.5%). Fertilization rates for ICSI and ROSI cases were 54.2% and 41.6%, respectively. The pregnancy rate per ET was 27.2%. None of the ROSI cases resulted in pregnancy. Two patients had spontaneous abortions at 8 and 18 weeks of gestation, respectively. Only one patient delivered a healthy female baby after 36 weeks of an uneventful pregnancy. CONCLUSION(S): Men with KS can benefit from assisted reproductive technologies, and the testicular sperm retrieval rate among them is promising. Although sex chromosome aberrations among the embryos from men with KS are not common, couples can be offered preimplantation genetic diagnosis before ET.  相似文献   
999.
Leptin receptor variant in women with polycystic ovary syndrome   总被引:3,自引:0,他引:3  
  相似文献   
1000.
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