全文获取类型
收费全文 | 860篇 |
免费 | 36篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 12篇 |
妇产科学 | 8篇 |
基础医学 | 95篇 |
口腔科学 | 13篇 |
临床医学 | 71篇 |
内科学 | 196篇 |
皮肤病学 | 39篇 |
神经病学 | 46篇 |
特种医学 | 28篇 |
外科学 | 221篇 |
综合类 | 5篇 |
预防医学 | 17篇 |
眼科学 | 1篇 |
药学 | 44篇 |
肿瘤学 | 99篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2019年 | 18篇 |
2018年 | 21篇 |
2017年 | 12篇 |
2016年 | 22篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 28篇 |
2012年 | 57篇 |
2011年 | 49篇 |
2010年 | 28篇 |
2009年 | 16篇 |
2008年 | 39篇 |
2007年 | 54篇 |
2006年 | 53篇 |
2005年 | 53篇 |
2004年 | 59篇 |
2003年 | 49篇 |
2002年 | 51篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 12篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1967年 | 2篇 |
1932年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有896条查询结果,搜索用时 15 毫秒
1.
Yoshitomo Kashiwagi Chikara Kikuchi Jun-ichi Anzai 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2002,518(1):51-55
Electrocatalytic dehalogenation of organohalides was studied using a nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode. The nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode was prepared by attaching nickel(II) (6-(2′-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane)perchlorate chemically to the carboxyl groups of a thin poly(acrylic acid) layer coated on the graphite felt. The modified electrode gave a reversible electron transfer for the nickel(II)/nickel(I) redox couple in cyclic voltammetry at ?0.95 V versus Ag/AgCl. A preparative electrocatalytic dehalogenation of organohalides was successfully achieved on the modified electrode with an adequate current efficiency (55.6–94.8%), conversion (34.2–100%) and turnover number of the Ni catalyst (667–3333). 相似文献
2.
Nishimura T Nishida N Itoh T Komeda T Fukuda Y Ikai I Yamaoka Y Nakao K 《Genes, chromosomes & cancer》2005,42(1):34-43
Recurrent chromosomal gain at 1q is one of the most common features of human hepatocellular carcinoma (HCC), but how the gain at 1q contributes to hepatocarcinogenesis is still unclear. To identify the target genes, precise determination of the shortest region of overlap (SRO) and of breakpoints is necessary. Similarly, the role of loss at 1p, which is also a major cytogenetic aberration in HCC, needs to be determined. Fifty HCCs were examined with the aid of 59 microsatellite markers distributed throughout both arms of chromosome 1. To detect allelic gain effectively, the cutoff value of the allelic imbalance index was set at 0.70. Alleles showing imbalance were subjected to multiplex PCR, using a retained allele as an internal control, to determine whether the imbalance was the result of chromosomal gain or loss. The SRO of the gains was defined as D1S2878-D1S2619 (1q23.-q25.3, 16.9 Mb), which involved 36 cases (72%). Gains in the number of copies of certain oncogenes within this region seemed to be critical for the pathogenesis of HCC. In contrast, the centromeric breakpoints of these gains varied, but they tended to occur mainly in the pericentromeric region (26 of 50 cases, 52%). Rearrangement of specific genes associated with the gains is unlikely. On the other hand, the SRO of deletion was defined as D1S2893-D1S450 (1p36.32-p36.22, 5.1 Mb). Four known putative tumor-suppressor genes (TP73, RIZ1, NBL1/DAN, and CDKN2C) were outside the SRO, suggesting the presence of other candidate genes with critical roles in hepatocarcinogenesis. 相似文献
3.
Koichiro Yuji Shigesaburo Miyakoshi Daisuke Kato Yuji Miura Tomohiro Myojo Naoko Murashige Yukiko Kishi Kazuhiro Kobayashi Eiji Kusumi Hiroto Narimatsu Tamae Hamaki Tomoko Matsumura Masahiro Kami Takahiro Fukuda Shigeru Masuo Kazuhiro Masuoka Atsushi Wake Junichi Ueyama Akiko Yoneyama Ko Miyamoto Haruhisa Nagoshi Michio Matsuzaki Shinichi Morinaga Yoshitomo Muto Yoichi Takeue Shuichi Taniguchi 《Biology of blood and marrow transplantation》2005,11(4):314-318
We report the results of reduced-intensity unrelated cord blood transplantation (RI-UCBT) in patients with advanced malignant lymphoma. Twenty patients (median age, 46.5 years; range, 27-66 years) underwent RI-UCBT with a preparative regimen consisting of fludarabine 125 mg/m2 , melphalan 80 mg/m 2 , and 4 Gy of total body irradiation. The median infused total cell dose was 2.75 x 10(7)/kg (range, 2.3-3.4 x 10(7)/kg). Graft-versus-host disease (GVHD) prophylaxis was composed of cyclosporine or tacrolimus alone. Fifteen patients achieved primary neutrophil engraftment after a median of 20 days. Eight patients developed grade II to IV acute GVHD, and 2 developed chronic GVHD. Of the 16 patients with evaluable disease, 10 achieved a complete response. Primary disease recurred in 1 patient, and transplant-related mortality within 100 days occurred in 8 of 20 patients. The estimated 1-year probability of progression-free survival was 50%. These data suggest that RI-UCBT is a feasible option for patients with refractory lymphoma who lack an HLA-matched donor. 相似文献
4.
5.
Nascent peptide-mediated translation elongation arrest coupled with mRNA degradation in the CGS1 gene of Arabidopsis 下载免费PDF全文
Onouchi H Nagami Y Haraguchi Y Nakamoto M Nishimura Y Sakurai R Nagao N Kawasaki D Kadokura Y Naito S 《Genes & development》2005,19(15):1799-1810
Expression of the Arabidopsis CGS1 gene that codes for cystathionine gamma-synthase is feedback regulated at the step of mRNA stability in response to S-adenosyl-L-methionine (AdoMet). A short stretch of amino acid sequence, called the MTO1 region, encoded by the first exon of CGS1 itself is involved in this regulation. Here, we demonstrate, using a cell-free system, that AdoMet induces temporal translation elongation arrest at the Ser-94 codon located immediately downstream of the MTO1 region, by analyzing a translation intermediate and performing primer extension inhibition (toeprint) analysis. This translation arrest precedes the formation of a degradation intermediate of CGS1 mRNA, which has its 5' end points near the 5' edge of the stalled ribosome. The position of ribosome stalling also suggests that the MTO1 region in nascent peptide resides in the ribosomal exit tunnel when translation elongation is temporarily arrested. In addition to the MTO1 region amino acid sequence, downstream Trp-93 is also important for the AdoMet-induced translation arrest. This is the first example of nascent peptide-mediated translation elongation arrest coupled with mRNA degradation in eukaryotes. Furthermore, our data suggest that the ribosome stalls at the step of translocation rather than at the step of peptidyl transfer. 相似文献
6.
The relationships between increases in body mass index (BMI) and increases in hypertension were compared between non-drinkers with elevated serum gamma-glutamyl transpeptidase (gamma-GTP) levels (> or = 50 U/l) and those with normal levels, who comprised 10,952 men and 22,107 women aged 40-59 years recruited from an occupational health clinic. Hypertension was found in 16.1% and 13.5% of the men and women, and elevated serum g-GTP was found in 10.8% and 2.8% of the men and women, respectively. The prevalences of hypertension and elevated serum gamma-GTP levels were both increased with increased BMI. Hypertension was, however, shown to be 1.5 times more prevalent in the persons with elevated serum gamma-GTP levels than in those with normal levels in both sexes, even after adjusting for BMI by a multiple logistic analysis. It can be concluded that elevations of serum gamma-GTP, which are probably a reflection of fatty liver in the non-drinkers, are closely related to the development of hypertension associated with increased obesity. 相似文献
7.
Daisuke Abe Toshiyuki Sakaki Tatsuya Kusudo Atsushi Kittaka Nozomi Saito Yoshitomo Suhara Toshie Fujishima Hiroaki Takayama Hiromi Hamamoto Masaki Kamakura Miho Ohta Kuniyo Inouye 《Drug metabolism and disposition》2005,33(6):778-784
Recently, we demonstrated that some A-ring-modified vitamin D3 analogs had unique biological activity. Of these analogs, 2alpha-propoxy-1alpha,25(OH)2D3 (C3O1) and 2alpha-(3-hydroxypropoxy)-1alpha,25(OH)2D3 (O2C3) were examined for metabolism by CYP27A1 and CYP24A1. Surprisingly, CYP27A1 catalyzed the conversion from C3O1 to O2C3, which has 3 times more affinity for vitamin D receptor than C3O1. Thus, the conversion from C3O1 to O2C3 by CYP27A1 is considered to be a metabolic activation process. Five metabolites were detected in the metabolism of C3O1 and O2C3 by human CYP24A1 including both C-23 and C-24 oxidation pathways. On the other hand, three metabolites of the C-24 oxidation pathway were detected in their metabolism by rat CYP24A1, indicating a species-based difference in the CYP24A1-dependent metabolism of C3O1 and O2C3 between humans and rats. Kinetic analysis revealed that the Km and kcat values of human CYP24A1 for O2C3 are, respectively, approximately 16 times more and 3 times less than those for 1alpha,25(OH)2D3. Thus, the catalytic efficiency, kcat/Km, of human CYP24A1 for O2C3 is only 2% of 1alpha,25(OH)2D3. These results and a high calcium effect of C3O1 and O2C3 in animal experiments using rats suggest that C3O1 and O2C3 are promising for clinical treatment of osteoporosis. 相似文献
8.
Urinary cadmium and serum levels of estrogens and androgens in postmenopausal Japanese women. 总被引:1,自引:0,他引:1
Chisato Nagata Yasuko Nagao Chiken Shibuya Yoshitomo Kashiki Hiroyuki Shimizu 《Cancer epidemiology, biomarkers & prevention》2005,14(3):705-708
BACKGROUND: Recent laboratory studies have suggested that cadmium is an estrogenic compound and may be a potential risk factor for breast cancer. METHODS: We investigated the relationship between urinary cadmium concentrations and serum concentrations of estrone, testosterone, and dehydroepiandrosterone sulfate in 164 postmenopausal Japanese women. RESULTS: There was a significant positive association between the urinary cadmium and serum testosterone levels after controlling for age and body mass index. The mean testosterone level was 28% higher in women with high urinary cadmium (> or = 3.00 microg/g creatinine) than in those with low urinary cadmium (< 2.00 microg/g creatinine). Urinary cadmium was not significantly associated with serum estrone and dehydroepiandrosterone sulfate levels. Additional adjustment for smoking, alcohol and reproductive factors including known risk factors for breast cancer did not substantially alter the results. CONCLUSION: Data suggested that cadmium exposure is associated with increased testosterone levels. As high testosterone levels have been associated with the risk of breast cancer, the involvement of cadmium exposure in breast cancer risk should be evaluated in future studies. 相似文献
9.
Makito Miyake Yosuke Morizawa Shunta Hori Yoshihiro Tatsumi Sayuri Onishi Takuya Owari Kota Iida Kenta Onishi Daisuke Gotoh Yasushi Nakai Satoshi Anai Yoshitomo Chihara Kazumasa Torimoto Katsuya Aoki Nobumichi Tanaka Keiji Shimada Noboru Konishi Kiyohide Fujimoto 《Cancer science》2017,108(11):2221-2228
Collagen type 4 alpha 1 (COL4A1) and collagen type 13 alpha 1 (COL13A1) produced by urothelial cancer cells support the vital oncogenic property of tumor invasion. We investigated the diagnostic and prognostic capability of COL4A1 and COL13A1 in voided urine and compared the observed values with those of fragments of cytokeratin‐19 (CYFRA21‐1), nuclear matrix protein 22 (NMP‐22), and voided urine cytology in bladder cancer (BCa). We collected voided urine samples from 154 patients newly diagnosed with BCa, before surgery and from 61 control subjects. Protein levels of COL4A1, COL13A1, CYFRA21‐1, and NMP‐22 in urine supernatants were measured using enzyme‐linked immunosorbent assays. Diagnostic performance and optimal cut‐off values were determined by receiver operating characteristic analysis. Urine levels of COL4A1, COL13A1, the combined values of COL4A1 and COL13A1 (COL4A1 + COL13A1), and CYFRA21‐1 were significantly elevated in urine from patients with BCa compared to the controls. Among these biomarkers, the optimal cut‐off value of COL4A1 + COL13A1 at 1.33 ng/mL resulted in 57.4%, 83.7%, 56.1%, 80.7%, and 91.7% sensitivity for low‐grade tumors, high‐grade tumors, Ta, T1, and muscle invasive disease, respectively. We evaluated the prognostic value of preoperative urine levels in 130 non‐muscle invasive BCa samples after the initial transurethral surgery. A high urinary COL4A1 + COL13A1 was found to be an independent risk factor for intravesical recurrence. Although these data need to be externally validated, urinary COL4A1 and COL13A1 could be a potential diagnostic and prognostic biomarker for BCa. This easy‐to‐use urinary signature identifies a subgroup of patients with a high probability of recurrence and progression in non‐muscle invasive and muscle invasive BCa. 相似文献
10.