全文获取类型
收费全文 | 12197篇 |
免费 | 526篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 129篇 |
妇产科学 | 186篇 |
基础医学 | 1344篇 |
口腔科学 | 613篇 |
临床医学 | 852篇 |
内科学 | 2926篇 |
皮肤病学 | 393篇 |
神经病学 | 707篇 |
特种医学 | 442篇 |
外科学 | 2078篇 |
综合类 | 48篇 |
预防医学 | 407篇 |
眼科学 | 382篇 |
药学 | 687篇 |
中国医学 | 23篇 |
肿瘤学 | 1400篇 |
出版年
2022年 | 102篇 |
2021年 | 177篇 |
2020年 | 132篇 |
2019年 | 145篇 |
2018年 | 187篇 |
2017年 | 150篇 |
2016年 | 157篇 |
2015年 | 156篇 |
2014年 | 232篇 |
2013年 | 282篇 |
2012年 | 537篇 |
2011年 | 525篇 |
2010年 | 352篇 |
2009年 | 260篇 |
2008年 | 543篇 |
2007年 | 568篇 |
2006年 | 518篇 |
2005年 | 527篇 |
2004年 | 544篇 |
2003年 | 467篇 |
2002年 | 488篇 |
2001年 | 451篇 |
2000年 | 555篇 |
1999年 | 481篇 |
1998年 | 163篇 |
1997年 | 111篇 |
1996年 | 107篇 |
1995年 | 104篇 |
1994年 | 82篇 |
1993年 | 70篇 |
1992年 | 248篇 |
1991年 | 278篇 |
1990年 | 269篇 |
1989年 | 318篇 |
1988年 | 289篇 |
1987年 | 244篇 |
1986年 | 218篇 |
1985年 | 226篇 |
1984年 | 137篇 |
1983年 | 118篇 |
1982年 | 61篇 |
1979年 | 144篇 |
1978年 | 98篇 |
1977年 | 90篇 |
1976年 | 70篇 |
1974年 | 95篇 |
1973年 | 74篇 |
1972年 | 73篇 |
1970年 | 61篇 |
1969年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
The direct correlation analyses between the distribution of chlorpromazine (pharmacokinetics) and the biochemical effects of the drug on monoamine metabolisms (pharmacodynamics) are reported. Both samples for quantitative determination of CPZ and of monoamine transmitters and metabolites were obtained by organic extraction procedures from the same sample. The determinations were carried out by high performance liquid chromatography with electrochemical detection. CPZ affected the concentrations of metabolites of noradrenaline, dopamine and 5-hydroxytryptamine, but not those of the monoamine transmitters themselves. However, simultaneous assay demonstrated differences in effects of the drug on the transmitter systems. The concentrations of HVA and DOPAC were increased over a wide range of intracerebral concentrations of the drug, but those of MOPEG, in the range of higher concentrations. On the other hand, CPZ did not reveal any correlations between the intracerebral concentrations of the drug and 5-HIAA. These results suggest that CPZ affected primarily the dopaminergic system rather than the serotonergic one in the early stage of its biochemical actions. The proposed procedure is demonstrated to be simple and useful as a new approach in biochemical pharmacology. The same procedure can be applicable for other centrally acting drugs. 相似文献
992.
F Hayakawa K Kuno Y Nakao N Yamamoto H Ishikawa H Kimura H Takeuchi 《The Japanese journal of antibiotics》1989,42(2):324-338
Laboratory and clinical studies on clarithromycin (TE-031, A-56268), a new macrolide antibiotic, were carried out in the field of pediatrics. The results obtained are summarized as follows: 1. Serum concentrations, urinary concentrations and urinary recovery rates were determined upon oral administration on fasting of TE-031 at doses of 5 mg/kg granules in 1 case and tablets in 2 cases, and 10 mg/kg granules in 1 and 15 mg/kg granules in 1. Peak serum levels were obtained at 30 minutes in 2 cases, at 1 hour in 2 cases and at 2 hours in 1 case after administration of the drug with a range of 2.29-7.10 micrograms/ml with half-lives of 2.2-7.5 hours. Urinary recovery rates in 6 hours after administration ranged from 7.1-34.5%. 2. MICs of TE-031 against 49 clinical isolates (Streptococcus pyogenes 5 strains, Streptococcus pneumoniae 9, Staphylococcus aureus 3, Branhamella catarrhalis 4, Haemophilus influenzae 14, Haemophilus parainfluenzae 7, and Campylobacter jejuni 7) were compared with those of josamycin (JM), erythromycin (EM), and ampicillin (ABPC). The antibacterial activity of TE-031 was superior to those of JM and equal to those of EM. 3. Fifty-five pediatric patients with acute infectious diseases (scarlet fever 3 cases, pharyngitis and tonsillitis 15, pertussis 2, pneumonia 10, bronchitis 14, Campylobacter enteritis 11) were treated with TE-031 at daily doses of 10-35 mg/kg t.i.d. as a rule. The efficacy rates were 96% clinically and 72% bacteriologically. 4. Side effects or abnormal laboratory test values were not observed. 5. None of children refused TE-031. 相似文献
993.
T Takimoto H Sato H Ogura T Ogura S Ishikawa J Iwawaki 《ORL; journal for oto-rhino-laryngology and its related specialties》1987,49(4):169-174
New world monkey (cotton-top marmoset; CTM) lymphocytes were transformed by two different strains of Epstein-Barr virus (EBV) derived from human nasopharyngeal epithelial/hybrid cells (NPC-KT and A2L/AH). M-KT cells were a CTM lymphoblastoid cell line which was transformed by EBV derived from NPC-KT cells (NPC-KT EBV). M-BA2L cells were a CTM lymphoblastoid cell line which was transformed by EBV derived from A2L/AH cells (A2L/AH EBV). EBV obtained from M-KT cells, like parental NPC-KT EBV, could transform human cord blood lymphocytes (HCBLs) and superinfect Raji cells. EBV obtained from M-BA2L cells, like parental A2L/AH EBV, could transform HCBLs but could not superinfect Raji cells. We have compared the EBV-DNA associated with M-KT cells to NPC-KT EBV-DNA. The results obtained using a DNA restriction enzyme (Hind III) showed that virus DNA prepared from NPC-KT cells is different from EBV-DNA prepared from CTM lymphocytes transformed by EBV derived from infectious mononucleosis (B95-8), but that virus DNA prepared from M-KT cells is identical with parental NPC-KT EBV. These results indicate the possibility that a single NPC-KT EBV is associated with two biological activities. 相似文献
994.
OBJECTIVE: During the treatment of pre-term labor with magnesium sulfate, we noted an abnormal elevation of maternal serum creatine phosphokinase. This study was aimed at evaluating the relationship between tocolysis with MgSO4 and maternal serum CPK elevation, which represents the possible damage of muscles by magnesium sulfate. METHODS: Clinical records of 45 women treated with magnesium sulfate and beta-sympathomimetics for the treatment of pre-term labor were retrospectively examined. RESULTS: Serum CPK was abnormally elevated in 32 out of 45 cases (71.1%), but in only one out of 21 in the control group. In three cases, the decrease of serum creatine phosphokinase after cessation of magnesium sulfate was demonstrated, despite the continuous infusion of beta-sympathomimetics. CONCLUSION: Magnesium sulfate may cause muscular damage and abnormal elevation of maternal serum creatine phosphokinase. Special attention must be paid to patients when drugs acting on muscle cells, for example succinyl choline, are going to be used. 相似文献
995.
996.
K Kataoka T Umekawa Y Katayama Y Ishikawa M Kodama C Takamura M Takada Y Kato K Hohri M Iguchi 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1991,82(5):799-803
Because human urine contains various substances which can affect each other, it is quite difficult to clarify the mechanism of formation of calcium oxalate (CaOx) crystal in urine. The authors recently determined CaOx crystalline content and the concentrations of other substances in urine specimens from patients with urolithiasis and healthy volunteers, and subjected the data to multi-regressive analysis for the purpose of assessing the effect of these urinary substances on CaOx crystal formation. 1. In analysis of urine from patients with urolithiasis, the partial correlation coefficients of CaOx crystal formation with oxalic acid, sodium, calcium, uric acid magnesium were 0.67, 0.28, 0.18, and -0.10, respectively. The formula of regression was as follows: Amount of CaOx crystal (X 10(6) microns3/ml) = 3.59 X 10(-2) Ox (mM/L) + 4.72 X 10(-3) Ca (mM/L) + 4.52 X 10(-3) Na (mM/L) + 2.51 X 10(-4) UA (mM/L) -2.39 X 10(-2) Mg (mM/L) -1.65. The multiple correlation coefficient was 0.759. Thus, in patients with urolithiasis, urinary crystal formation was most dependent on the oxalic acid level, sodium, calcium, and uric acid were found to promote crystal formation, while magnesium to suppress it. 2. In analysis of urine from healthy volunteers, the partial correlation coefficients of CaOx crystal formation with oxalic acid and inorganic phosphorus were 0.51 and -0.24, respectively. The formula of regression was as follows: Amount of CaOx crystal (X 10(6) microns3/ml) = 1.91 X 10(-2) Ox (mM/L) -3.43 X 10(-4) P (mM/L) +0.29 The multiple correlation coefficient was 0.525.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
997.
We compared the pattern and reserve of coronary flow in 8 cases of hypertrophic non-obstructive cardiomyopathy (H) with those in 20 cases of chest pain not accompanied by organic heart disease (N). A catheter-tip Doppler velocimeter was positioned in the proximal portion of the left anterior descending (LAD), circumflex (LCX) and right coronary (RCA) arteries. Coronary flow velocity (Vs: systolic peak, Vd: diastolic peak, Vm: mean) was recorded and the area under the velocity curve was divided into systole (* s) and diastole (* d). The time interval between the dicrotic notch in aortic pressure and the peak of diastolic flow velocity was measured (Tpv). Vm was measured before and after intracoronary injection of 6 ml of contrast media, and peak to resting velocity ratio (PRVR) was calculated as an index of coronary flow reserve. Result: In LAD, N showed diastolic predominant coronary flow pattern without backward flow. In H, diastolic predominance was more prominent with systolic backward flow, resulting in decrease in * s/* d(H: 0.07 +/- 0.04, N: 0.25 +/- 0.02, p less than 0.01). In H, Vd (H: 20.1 +/- 2.8, N: 9.2 +/- 1.4 cm/sec, p less than 0.05) and Vm(H: 9.5 +/- 1.3, N: 4.9 +/- 0.7 cm/sec, p less than 0.05) were higher, while PRVR was lower (H: 1.7 +/- 0.1, N: 2.6 +/- 0.1, p less than 0.05). In both N and H, the flow pattern of LCX was diastolic predominant with two peaks (one in systole and the other in diastole).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
998.
Synergistic interactions between footshocks and non-osmotic hypovolemia on vasopressin secretion in rats 总被引:1,自引:0,他引:1
Katsuei Shibuki Tatsushi Onaka Mitsuko Hamamura Kinji Yagi San-e Ishikawa Toshikazu Saito Sho Yoshida 《Brain research》1987,410(1):140-142
The effects of i.p. injected hypertonic NaCl and polyethylene glycol on the magnitude of increase in plasma vasopressin after footshocks were studied in male rats, to determine whether hypovolemia and body fluid osmolality interact with noxious stimuli on vasopressin secretion. Present data have demonstrated that non-osmotic hypovolemia but not body fluid hyperosmolarity interact significantly and synergistically with footshocks to potentiate vasopressin secretion. 相似文献
999.
T Kohno I Sakoda M Suzuki A Izumi E Ishikawa 《Journal of clinical laboratory analysis》1991,5(5):307-316
An immune complex transfer enzyme immunoassay for (anti-human T-cell leukemia virus type I) IgG (anti-HTLV-I IgG) in serum using a synthetic peptide, cys-gag p19(100-130), is described. Anti-HTLV-I IgG in test serum, which had been incubated with excess of inactive beta-D-galactosidase to eliminate interference by anti-beta-D-galactosidase antibodies, was reacted simultaneously with 2,4-dinitrophenyl bovine serum albumin-cys-gag p19(100-130) conjugate and cys-gag p19(100-130)-beta-D-galactosidase conjugate. The complex formed of the three components was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG. After washing to eliminate nonspecific IgG in the test serum and excess of the beta-D-galactosidase conjugate, the complex was eluted from the polystyrene balls with epsilon N-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. Beta-D-Galactosidase activity bound to the (anti-human IgG gamma-chain) IgG-coated polystyrene balls was assayed by fluorometry. This assay was 100-fold more sensitive than the conventional enzyme immunoassay, in which a cys-gag p19(100-130)-bovine serum albumin-coated polystyrene ball was incubated with test serum and, after washing, with (anti-human IgG gamma-chain) Fab'-peroxidase conjugate. The degree of inhibition by preincubation of test sera with excess of cys-gag p19(100-130) in combination with an appropriate cut-off value for the fluorescence intensity of bound beta-D-galactosidase activity discriminated almost all seropositive samples from seronegative ones. 相似文献
1000.
S Umeki S Kyoizumi Y Kusunoki N Nakamura M Sasaki T Mori Y Ishikawa J B Cologne M Akiyama 《Japanese journal of cancer research》1991,82(12):1349-1353
Exposure to ionizing radiation has long been well-recognized as a risk factor for cancer development. Since ionizing radiation can induce mutations, an accurate way of measuring somatic mutation frequencies could be a useful tool for evaluating cancer risks. In the present study, we have examined in vivo somatic mutation frequencies at the erythrocyte glycophorin A (GPA) and T-cell receptor (TCR) loci in 18 Thorotrast patients who have been continuously irradiated with alpha-particles emitted from the internal deposition of thorium dioxide and who thus have increased risks of certain malignant tumors. When compared with controls, the results showed a significantly higher frequency of mutants at the lymphocyte TCR loci but not at the erythrocyte GPA loci in the Thorotrast patients. The discrepancy between the results of the two assays is discussed. 相似文献