全文获取类型
收费全文 | 1602篇 |
免费 | 110篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 87篇 |
妇产科学 | 19篇 |
基础医学 | 190篇 |
口腔科学 | 38篇 |
临床医学 | 164篇 |
内科学 | 359篇 |
皮肤病学 | 26篇 |
神经病学 | 55篇 |
特种医学 | 260篇 |
外科学 | 92篇 |
综合类 | 64篇 |
预防医学 | 197篇 |
眼科学 | 20篇 |
药学 | 54篇 |
中国医学 | 11篇 |
肿瘤学 | 66篇 |
出版年
2022年 | 6篇 |
2021年 | 10篇 |
2020年 | 7篇 |
2019年 | 17篇 |
2018年 | 14篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 26篇 |
2014年 | 47篇 |
2013年 | 87篇 |
2012年 | 51篇 |
2011年 | 51篇 |
2010年 | 46篇 |
2009年 | 76篇 |
2008年 | 57篇 |
2007年 | 92篇 |
2006年 | 54篇 |
2005年 | 51篇 |
2004年 | 48篇 |
2003年 | 33篇 |
2002年 | 39篇 |
2001年 | 26篇 |
2000年 | 34篇 |
1999年 | 31篇 |
1998年 | 83篇 |
1997年 | 60篇 |
1996年 | 69篇 |
1995年 | 50篇 |
1994年 | 53篇 |
1993年 | 50篇 |
1992年 | 18篇 |
1991年 | 20篇 |
1990年 | 24篇 |
1989年 | 53篇 |
1988年 | 32篇 |
1987年 | 35篇 |
1986年 | 28篇 |
1985年 | 23篇 |
1984年 | 24篇 |
1983年 | 18篇 |
1982年 | 15篇 |
1981年 | 23篇 |
1980年 | 15篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 19篇 |
1976年 | 8篇 |
1975年 | 14篇 |
1974年 | 4篇 |
1970年 | 5篇 |
排序方式: 共有1721条查询结果,搜索用时 15 毫秒
61.
During the period from January 1970 until December 1973, therapy was started in 41 previously untreated adolescents and adults with acute lymphoblastic leukemia. Induction therapy was started with vincristine and prednisone in all patients, resulting in complete remission in 19 and death due to infection during the first month in one case. After 3 wk on these two drugs, the addition of daunorubicin was required in the remaining 21 patients. Fifteen of these obtained remission, one died during induction therapy, and five patients were unresponsive to this therapy, as well as to all subsequent induction schemes. The overall remission rate was 83%. Significantly higher initial leukocyte counts were found in the group treated with vincristine, prednisone, and daunorubicin. Meningeal leukemia prophylaxis, by either periodic methotrexate injections given intrathecally or a combination of cranial irradiation and intrathecally administrated methotrexate, was administered in 29 therapy responders. The median duration of complete remission obtained with various maintenance therapy schemes was 13 mo. No differences were seen in the results obtained in patients between 14 and 20 yr of age and older patients. Twenty-two patients relapsed within 2-37 mo. Relapses were confined to the central nervous system in two cases, to the bone marrow in 18, and to the bone marrow and CNS simultaneously in two. A second remission was obtained in 17 cases (77%). The median survival time of the whole group was 27 mo, as compared with 32 mo for therapy responders and 7 mo for the nonresponders. The percentage and duration of remission and the survival time in our group of adolescents and adults were comparable to those currently being achieved in other centers, but not as good as those reported for children treated with the same protocols. 相似文献
62.
Fetal persistent middle cerebral artery reversed end diastolic flow is a rare and ominous finding. Previous cases have been associated with intracranial hemorrhage, growth restriction, anaemia, and hepatic anomaly. Intrauterine demise or early neonatal death is a common outcome. We report the case of persistent middle cerebral artery reversed end diastolic flow in a well-grown fetus at 32 weeks’ gestation resulting from acute, severe anaemia due to a large feto-maternal hemorrhage. An emergency cesarean section was performed and the neonate required advanced resuscitation and immediate blood transfusion. Postnatal magnetic resonance imaging confirmed a hemorrhagic parietal infarct and bilateral ischaemic changes in the basal ganglia. This provides further evidence that persistent middle cerebral artery reversed end diastolic flow in any fetus is an ominous finding warranting urgent diagnostic evaluation and/or delivery. 相似文献
63.
Autologous bone marrow transplantation for acute myeloid leukemia using busulfan plus etoposide as a preparative regimen 总被引:1,自引:0,他引:1
We have studied the use of a new preparative regimen for the treatment of patients in remission of acute myeloid leukemia (AML) with autologous bone marrow transplantation. Chemotherapy consisted of busulfan 1 mg/kg every 6 hours for 4 days (total dose, 16 mg/kg) on days -7 through -4 followed by an intravenous infusion over 6 to 10 hours of etoposide 60 mg/kg on day -3. Autologous bone marrow, treated in vitro with 100 micrograms/mL of 4-hydroperoxycyclophosphamide, was infused on day 0. We have treated 58 patients up to the age of 60 years, 32 in first remission, 21 in second or third remission, and 5 with primary refractory AML unresponsive to high-dose Ara-C, but achieving remission with aggressive salvage regimens. Of the first remission patients, there has been 1 treatment related death and 5 relapses. With median follow-up of 22 months, the actuarial relapse rate is 22% +/- 9% and disease-free survival is 76% +/- 9% at 3 years. Patients with favorable French-American-British (FAB) subtypes (M3 or M4 EO) did especially well, with no relapses seen in 15 patients observed for a median of 30 months. Actuarial relapse rate at 3 years was 48% for first remission patients with less favorable FAB subtypes. Of patients in second or third remission, there were 5 treatment related deaths and 4 relapses. With median follow-up of 22 months, the actuarial relapse rate is 25% +/- 11% and disease-free survival is 56% +/- 11% at 3 years. Four of five primary refractory patients died during treatment and 1 remains in remission with short follow-up. These preliminary data are very encouraging and, if confirmed, support the use of autologous purged bone marrow transplantation using aggressive preparative regimens as one approach to improve the outcome of adults with AML. 相似文献
64.
Contrast Ultrasound Imaging of the Aorta Does Not Affect Progression of Atherosclerosis or Cardiovascular Biomarkers in ApoE−/− Mice 下载免费PDF全文
65.
Tong S Lingappa JR Chen Q Shu B LaMonte AC Cook BT Birge C Chern SW Liu X Galloway R Mai le Q Ng WF Yang JY Butany J Comer JA Monroe SS Beard SR Ksiazek TG Erdman D Rota PA Pallansch MA Anderson LJ 《The Journal of infectious diseases》2004,190(6):1127-1131
Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) emerged, in November 2002, as a novel agent causing severe respiratory illness. To study sequence variation in the SARS-CoV genome, we determined the nucleic acid sequence of the S and N genes directly from clinical specimens from 10 patients--1 specimen with no matched SARS-CoV isolate, from 2 patients; multiple specimens from 3 patients; and matched clinical-specimen/cell-culture-isolate pairs from 6 patients. We identified 3 nucleotide substitutions that were most likely due to natural variation and 2 substitutions that arose after cell-culture passage of the virus. These data demonstrate the overall stability of the S and N genes of SARS-CoV over 3 months during which a minimum of 4 generations for transmission events occurred. These findings are a part of the expanding investigation of the evolution of how this virus adapts to a new host. 相似文献
66.
BACKGROUND & AIMS: The functional significance of intestinal hyperplasia stimulated by insulin-like growth factor (IGF)-I is unclear and has not been studied in a model of mucosal atrophy induced by total parenteral nutrition (TPN). The aim of this study was to determine how IGF-I affects intestinal structure and epithelial function in the absence of luminal nutrition caused by TPN. METHODS: Rats were maintained with TPN with or without IGF-I (800 micrograms/day), and jejunal histology and epithelial ion transport were measured after 5 days. In a third TPN group without IGF-I, a short-term dose of IGF-I was added during in vitro flux chamber experiments. RESULTS: Rats given TPN with IGF-I had greater jejunal mucosal weight, greater protein and DNA content, and increased villus height and crypt depth compared with rats given TPN only. TPN increased ionic permeability and ion transport responses to secretory and absorptive agents. IGF-I in vivo reversed most of these changes; IGF-I in vitro enhanced sodium-dependent glucose absorption but had no other effects. CONCLUSIONS: Coinfusion of recombinant human IGF-I with TPN solution stimulates intestinal hyperplasia and attenuates transport changes induced by TPN. The latter effect seems to be primarily associated with the growth state of the epithelium. (Gastroenterology 1996 Dec;111(6):1501-8) 相似文献
67.
Corzo D; Yunis JJ; Salazar M; Lieberman JA; Howard A; Awdeh Z; Alper CA; Yunis EJ 《Blood》1995,86(10):3835-3840
Genes of the major histocompatibility complex (MHC) have been associated with susceptibility to drug-induced adverse reactions. We previously found that clozapine-induced agranulocytosis (CA) is associated with the HLA-DRB1*0402, DRB4*0101, DQB1*0302, DQA1*0301 haplotype in Ashkenazi Jewish patients and with the HLA-DRB1*1601, DRB5*02, DQB1*0502, DQA1*0102 haplotype in non-Jewish patients. In the present study, we tested the hypothesis that the variants of the heat- shock protein 70 (HSP-70) encoded by the HSP-70 loci located within the MHC region and known to be involved in apoptosis and regulation of cell proliferation could play an important role in molecular mechanisms of CA. First, we analyzed HSP70-2 polymorphism in risk-associated haplotypes from HLA homozygous cells and normal individuals and confirmed that the HSP70-2 9-kb variant was associated invariably with DR4 (HLA-DRB1*0402, DQB1*0302) and DR2 (HLA-DRB1*01601, DQB1*0502, DQA1*0102 and HLA-DRB1*1501, DQB1*0602) haplotypes, which were the haplotypes found increased in Jewish and non-Jewish patients with CA, respectively. The 9.0-kb variant was also found to be associated with HLA-B44, DRB1*0401 and HLA-B44, DRB1*07 haplotypes. Second, in patients with CA (12 Ashkenazi Jewish and 20 non-Jewish patients), HSP70-1 A and HSP70-2 9.0-kb variants were associated with the MHC haplotypes found by us to be markers of susceptibility to CA. The clozapine-treated control group had an excess number of HSP70-1 C and HSP70-2 8.5-kb variants, consistent with genetic resistance to CA associated with those variants. This finding supports our hypothesis that a dominant gene within the MHC region (marked by HSP70-1 and HSP70-2), but not necessarily HLA, is associated with CA in two different ethnic groups. 相似文献
68.
69.
70.
CA Tan D. del Gaudio M.A. Dempsey K. Arndt S. Botes A. Reeder S. Das 《Clinical genetics》2014,85(4):353-358
Primary Autosomal Recessive Microcephaly (MCPH) is characterized by congenital microcephaly usually without additional clinical findings. The most common gene implicated in MCPH is ASPM and a large percentage of mutations described have been homozygous and in consanguineous families primarily of East Asian and Middle Eastern origin. ASPM sequencing was performed on 400 patients between the years 2009 and 2012. Seventy of the patient samples were also analyzed for copy number changes in the ASPM gene. Forty protein truncating mutations, including 29 novel mutations, were identified in 39 patients with MCPH. Approximately one third of patients were compound heterozygotes, indicative of non‐consanguinity in these patients. In addition, 46 non‐synonymous variants were identified and interpreted as variants of uncertain significance. No deletion/duplication in ASPM was identified in the patients analyzed. A wide ethnic distribution was observed, including the first reported patients with ASPM‐related MCPH of Hispanic descent. Clinical information was collected for 26 of the ASPM‐positive patients and 41 of the ASPM‐negative patients. As more individuals are identified with MCPH, we anticipate that we will continue to identify ASPM mutation‐positive patients from all ethnic origins supporting the occurrence of this genetic condition beyond that of consanguineous families of certain ethnic populations. 相似文献