全文获取类型
收费全文 | 4238篇 |
免费 | 166篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 129篇 |
儿科学 | 64篇 |
妇产科学 | 213篇 |
基础医学 | 519篇 |
口腔科学 | 38篇 |
临床医学 | 358篇 |
内科学 | 1301篇 |
皮肤病学 | 39篇 |
神经病学 | 345篇 |
特种医学 | 67篇 |
外科学 | 497篇 |
综合类 | 26篇 |
一般理论 | 1篇 |
预防医学 | 142篇 |
眼科学 | 59篇 |
药学 | 312篇 |
中国医学 | 3篇 |
肿瘤学 | 315篇 |
出版年
2024年 | 8篇 |
2023年 | 33篇 |
2022年 | 201篇 |
2021年 | 299篇 |
2020年 | 71篇 |
2019年 | 98篇 |
2018年 | 118篇 |
2017年 | 83篇 |
2016年 | 102篇 |
2015年 | 126篇 |
2014年 | 163篇 |
2013年 | 206篇 |
2012年 | 322篇 |
2011年 | 338篇 |
2010年 | 169篇 |
2009年 | 115篇 |
2008年 | 280篇 |
2007年 | 313篇 |
2006年 | 255篇 |
2005年 | 240篇 |
2004年 | 266篇 |
2003年 | 240篇 |
2002年 | 175篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 20篇 |
1998年 | 23篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 11篇 |
1985年 | 5篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1971年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有4428条查询结果,搜索用时 312 毫秒
991.
Pawel J. Wiechno Grazyna M. Poniatowska Wojciech Michalski Jakub Kucharz Malgorzata Sadowska Joanna Jonska-Gmyrek Karol Nietupski Joanna Rzymowska Tomasz Demkow 《Medical oncology (Northwood, London, England)》2017,34(7):123
Cancer and its treatment can lead in men to testosterone deficiency, accompanied by somatic and mental symptoms. Germ cell tumours and their treatment may disturb the pituitary–gonadal axis, hence leading to significant clinical abnormalities. In some prostate cancer patients, castration, temporary or permanent, is a desired therapeutic condition. Yet, it is burdened with various side effects of complex intensity and significance. Last but not least, patients in the terminal stage of a malignancy present with low testosterone concentrations as a part of anorexia–cachexia syndrome. Oncological management of such patients disturbs their homeostasis, androgen metabolism included, which results in numerous complications and worsens their quality of life. In the present paper, we analysed the frequency and sequelae of testosterone deficiency in some clinical scenarios, on the basis of original papers, meta-analyses and reviews available in PubMed. Androgen secretion disorders in male cancer patients depend on a cancer type, stage and methods of treatment. Number of testicular cancer survivors is increasing, and as a consequence, more patients cope with late complications, testosterone deficiency included. Hormone therapy in prostate cancer patients significantly prolongs survival, and then numerous men experience long-term adverse effects of androgen deficiency. Those, in turn, particularly the metabolic syndrome, may contribute to increased mortality. Androgen deficiency is a part of cancer anorexia–cachexia syndrome. The role of androgen deficiency in cancer patients is still under debate, and further studies are urgently needed to establish appropriate clinical guidelines. 相似文献
992.
Dawidowska M Derwich K Szczepański T Jółkowska J van der Velden VH Wachowiak J Witt M 《Leukemia research》2006,30(9):1119-1125
We studied 23 Polish children with precursor-B-ALL, using PCR-heteroduplex analysis and DNA sequencing, to determine the availability of Ig/TCR gene rearrangements as patient-specific MRD-RQ-PCR targets. We found IGH, IGK-Kde, incomplete TCRD, Vdelta2-Jalpha, TCRG and TCRB rearrangements in 83%, 39%, 61%, 35%, 61% and 13% of patients, respectively. Comparison of Ig/TCR gene rearrangements pattern (frequency and characteristics of rearrangements) in Polish patients with those reported for patients of other European nationalities did not show major differences. These results are the first promising step for further development of MRD study in Polish patients according to current diagnostic standards. 相似文献
993.
Wittczak T Dudek W Krakowiak A Walusiak J Pałczyński C 《International journal of occupational medicine and environmental health》2008,21(1):81-83
Manganese belongs to a group of agents called "transitional metals" that are known to induce occupational asthma. However, well-documented cases of manganese-induced asthma have been lacking thus far. We have discussed a case of a 42-year-old non-smoking welder with work-related dyspnea. A number of clinical procedures were performed including clinical examination, routine laboratory tests, total serum IgE, skin prick tests to common aeroallergens and manganese nitrate, resting spirometry test, histamine challenge, and a single-blind, placebo-controlled specific inhalation challenge with 0.1% manganese chloride solution. Clinical findings and laboratory test results remained normal but a significant bronchial hyperreactivity was found. During the specific inhalation challenge, dyspnea and a significant decrease in forced expiratory volume (FEV1) were observed. An increased proportion of eosinophils and basophils in induced sputum could also be noted at 4 and 24 h after the challenge. The argument for recognizing the condition as occupational asthma was a positive clinical response to the specific challenge test as well as the morphological changes found in induced sputum. To our knowledge, this is the first well-documented case of manganese-induced occupational asthma. 相似文献
994.
Amifostine differentially modulates DNA damage evoked by idarubicin in normal and leukemic cells 总被引:3,自引:0,他引:3
Human lymphocytes, p53 protein-deficient acute promyelocytic leukemia cell line HL-60, murine pro-B lymphoid cell line BaF3 and its TEL/ABL-transformed clone cells were exposed to idarubicin with and without pre-treatment with amifostine. Idarubicin at 0.5–5 μM evoked DNA damage measured by the Comet assay. Amifostine at 14 mM decreased DNA-damaging effect of idarubicin in human lymphocytes and BaF3 cells, but increased the effect in TEL/ABL-transformed cells. Amifostine had no influence on the action of idarubicin in HL-60 cells. Our results suggest that the reaction of the cell to DNA damage may contribute to its diverse response to amifostine combined with anticancer drugs and that p53 and fusion tyrosine kinases may be involved in this diversity. 相似文献
995.
Marek Droździk Joanna Stefankiewicz Rafał Kurzawa Wanda Górnik Tomasz Bączkowski Mateusz Kurzawski 《Pharmacological reports : PR》2009,61(4):690-696
Infertility is a common problem affecting one in six couples, and in 30% of infertile couples, the male factor is a major cause due to defective sperm quality. P-glycoprotein (P-gp), a product of the MDR1 (ABCB1) gene, may be a link between genetic and environmental factors contributing to the development of male infertility because pesticides (P-gp substrates) are well established factors of male infertility. The aim of the present study was to examine the effect of the MDR1 gene 3435C>T polymorphism on male infertility. In total, 162 male patients undergoing semen analysis due to initial infertility workup were included in the study. The control group consisted of 191 healthy males with proven fertility. MDR1 3435C>T genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Assessment of MDR1 genotypes among the infertile men showed that 17.9% of subjects were carriers of the CC genotype, 58.0% were CT and 24.1% were TT. Among fertile men, 30.4% of subjects were characterised by the CC genotype, 49.7% were CT and 19.9% were TT. In addition, the frequency of carriers of at least one T allele (i.e., CT and TT genotypes) among infertile and fertile subjects was 82.1% and 69.6%, respectively. The risk of infertility was significantly elevated by two-fold in individuals carrying at least one T allele (CT and TT genotypes: p = 0.009, OR = 2.00, 95% CI: 1.20–3.32). Furthermore, this elevated risk was still found when considering each of the CT and TT genotypes alone (TT genotype: p = 0.027, OR = 2.05, 95% CI: 1.09–3.86; CT genotype: p = 0.013, OR = 1.98, 95% CI: 1.16–3.36). This preliminary report suggests that P-gp may play some role in male infertility, mediating detrimental effects of environmental factors. 相似文献
996.
Mirosław Czuczwar Jacek Cięszczyk Katarzyna Czuczwar Jacek Kiś Tomasz Saran Waldemar A. Turski 《Pharmacological reports : PR》2009,61(4):732-736
Orphenadrine is an anticholinergic drug used in the treatment of Parkinson’s disease, and is also known to exert nonspecific antagonistic activity at the phencyclidine binding site of the N-methyl-D-aspartate (NMDA) receptor. The aim of this study was to assess the anticonvulsant properties of orphenadrine and to evaluate its effect on the anticonvulsant activity of antiepileptic drugs against maximal electroshock-induced seizures in mice. Orphenadrine given at a dose of 5.65 mg/kg elevated the electrical seizure threshold from 5.7 (5.4 – 6.1) to 6.8 (6.3–7.3) mA, while a dose of 2.8 mg/kg was ineffective. The ED50 values of orphenadrine administered 10,30 and 120 min before maximal electroshock-induced convulsions were 16.8 (11.3–25.1), 17.8 (15.7–20.0) and 25.6 (23.3–28.3) mg/kg, respectively. Orphenadrine at a sub-threshold dose of 2.8 mg/kg significantly enhanced the anticonvulsant activity of valproate by reducing its ED50 value from 315.8 (270.0–369.4) to 245.9 (207.1–292.0) mg/kg without affecting the free plasma levels of valproate. However, orphenadrine failed to enhance the protective activity of carbamazepine, phenytoin, phenobarbital, lamotrigine, topiramate, or oxcarbazepine against maximal electroshock-induced seizures. 相似文献
997.
Opoka W Baś B Reczyński W Płonka M Drozdowicz D Sliwowski Z Brzozowski T 《Acta poloniae pharmaceutica》2011,68(4):481-492
The aim of the work was to compare two analytical methods of trace analysis in respect to their applicability in heavy metals determination in biological samples. Atomic absorption spectrometry (AAS) may be considered as the method of choice in such analyses due to its accuracy, precision and low detection limit. On the other hand, voltammetric methods seem to be as useful, but rarely applied. Having in mind that there is no universal analytical method, we have compared two AAS and voltammetric methods as the tools for Zn and Cu determination in the samples collected from rat gastric juice and gastric mucosa. Construction of the renewable silver amalgam film electrode (Hg(Ag)FE) for stripping voltammetry was described. Detailed optimization of measurements procedure and sample preparation for differential pulse anodic stripping voltammetry (DP ASV) and AAS were also performed and presented. The obtained results of quantitative analysis of the chosen parameters by means of both methods are discussed. 相似文献
998.
Lack of Z-DNA conformation in mitomycin-modified polynucleotides having inverted circular dichroism. 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M Tomasz J K Barton C C Magliozzo D Tucker E M Lafer B D Stollar 《Proceedings of the National Academy of Sciences of the United States of America》1983,80(10):2874-2878
Poly(dG-dC) . poly(dG-dC) and Micrococcus lysodeikticus DNA were modified by exposure to reductively activated mitomycin C, an antitumor antibiotic. The resulting covalent drug-polynucleotide complexes displayed varying degrees of CD inversions, which are strikingly similar to the inverted spectrum observed with Z-DNA. The following criteria have been used to establish, however, that the inverted CD pattern seen in mitomycin C-polynucleotide complexes does not reflect a Z-DNA conformation. (i) The ethanol-induced transition of poly(dG-dC) . poly(dG-dC) from B to Z conformation is not facilitated but rather is inhibited by mitomycin C modification. This may be due to the presence of crosslinks, (ii) Radioimmunoassay indicated no competition for Z-DNA-specific antibody by any of the mitomycin C-modified polynucleotides, (iii) 31P NMR of the complexes yielded a single relatively narrow resonance, which is inconsistent with the dinucleotide repeat characteristic of Z-DNA. Alternative explanations for the inverted CD pattern include a drug-induced left-handed but non-Z conformational change or the superposition of an induced CD onto the CD of B-DNA due to drug-base electronic interactions. These results illustrate the need for caution in interpreting CD changes alone as an indication of Z-DNA conformation. 相似文献
999.
Tomasz Trojanowski Jerzy P ceszyński Krzysztof Turowski Stanisław Kamiński Igor Gościński Marian Reinfus Tadeusz Krzyszkowski Marek Pyrich Adam Bielawski Czesława Leszczyk Barbara Bendarzewska Andrzej Staszczak Halina Koźniewska 《Journal of neuro-oncology》1988,6(3):285-291
A prospective, randomized trial evaluates the effects of two postoperative treatment regimens on survival in 198 adult patients with supratentorial gliomas. All patients were irradiated with 6 000 rads after possibly radical removal of tumors. CCNU administration in the dosis of 100 mg/sq m of body surface every 6–8 weeks following surgery proved to have no significant effect on the survival of patients. The median survival time in patients receiving radiation therapy alone was 61±7 weeks, while in those receiving additional chemotherapy was 56±4 weeks. Tumor histological malignancy and patients age were found to be the only important prognostic factors, irrespective of the treatment modality.
Address for offprints: T Trojanowski, Department of Neurosurgery, Medical School, Jaczewskiego 8, 20-950 Lublin, Poland 相似文献
1000.
Marta Misiuk‐Hojło Ryszard Międzybrodzki Andrzej Grzybowski Czesław Ługowski Tomasz Niedziela Anna Turno‐Kręcicka Stanisław Szymaniec 《Acta ophthalmologica. Supplement》2011,89(3):e283-e288
Purpose: Endotoxins have been proved to be responsible for acute anterior uveitis (AAU) in animals in a well‐established experimental model of endotoxin‐induced uveitis (EIU). The purpose of our study was the detection of antibodies against endotoxins of selected enterobacteria in the serum of patients with idiopathic AAU and searching for correlations between the levels of these antibodies and the presence of HLA‐B27 antigen as well as characteristic signs of EIU such as bilaterality and the absence of spontaneous recurrences of the disease. Methods: Reactions of serum IgG antibodies with lipopolysaccharides (LPSs) of Escherichia coli O1, E. coli O10, E. coli O111, E. coli J5, and Klebsiella pneumoniae O3 were determined for 60 patients with idiopathic AAU and 40 healthy volunteers. The presence of HLA‐B27 antigen in patients was determined. Documentation of the frequency of recurrences of AAU during a follow‐up period of 8 years was collected. Results: We have observed that the sera of patients with a first attack of AAU reacted stronger with the LPS of K. pneumoniae O3 than the sera of patients with relapse of the disease. Patients with bilateral AAU had markedly higher levels of antibodies against four of the five used LPSs than patients with one eye involved. A multiply comparison showed higher levels of IgG reacting with LPS of E. coli O111 in patients with bilateral eye inflammation admitted with the first attack of AAU comparing to controls. The incidence of recurrent form of AAU was significantly increased in HLA‐B27‐positive patients compared to HLA‐B27‐negative patients. However, we found in HLA‐B27 carriers that those with the bilateral form of AAU had over three times smaller risk of recurrence and showed stronger immunization by endotoxins than patients with unilateral inflammation. Conclusion: Our results suggest a potential role of endotoxins in the aetiology of the nonrecurrent bilateral form of AAU. We suggest that not only HLA‐B27 status but also determination of number of involved eyes may be useful to assess the risk of recurrence of the idiopathic AAU. 相似文献