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91.
Electronic grids for electrostatic imaging systems 总被引:1,自引:0,他引:1
92.
In the absence of data on current or likely patterns of use of magnetic resonance (MR) imaging, use of computed tomography (CT) at one institution in 1981 and 1984 was analyzed to provide data relevant to current federal deliberations regarding Medicare payment for inpatient MR imaging. Between 1981 and 1984 inpatient CT utilization increased 59%, primarily due to a 265% increase in body CT. In 1984 inpatients who underwent at least one CT procedure were as likely to undergo more than one procedure as to undergo only one. CT procedures were performed in a high proportion of diagnosis-related groups (DRGs), with more than one-half of head CT procedures performed in non-neurologic DRGs. Given the similarities between clinical applications of CT and MR imaging, these findings regarding CT utilization have the following implications: (a) a delay in recalibration of DRG payment rates may not take account of expected growth in utilization of MR imaging, (b) a DRG "add-on" for MR imaging should reflect the likelihood that more than one MR imaging procedure will be performed in many hospitalizations, and (c) adjustments in DRG payments for MR imaging should not be limited to the 35 neurologic DRGs. 相似文献
93.
94.
Numerous randomized controlled trials (RCTs) have been conducted to define the relative benefits of low-osmolality contrast media (LOM) and high-osmolality contrast media (HOM). Because of the clinical and economic significance of the conclusions drawn from these RCTs, the authors used a standardized instrument to evaluate the quality of study design and data analysis of 100 RCTs published between 1982 and 1987 that compared LOM and HOM. The mean quality score (+/- standard deviation) was 39 +/- 12 (maximum possible score, 100). The largest number of patients studied in any RCT was 435; the smallest was five. A majority of the RCTs received high scores on three attributes of quality, intermediate scores on seven, and low scores on nine. These results underscore the difficulty of designing, performing, analyzing, and reporting high-quality RCTs. Nevertheless, limitations in study design and data analysis need to be considered when interpreting results of these RCTs. Future RCTs comparing LOM and HOM should be performed with greater attention to basic elements of good study design and data analysis. 相似文献
95.
96.
Wojciech Waha Maksymilian Mielczarek Grzegorz Smolka Tomasz Roleder Miosz Jaguszewski Dariusz Ciewierz Brunon Tomasiewicz Piotr Kubler Jarosaw Gorol Micha Chmielecki Stanisaw Bartu Eliano Pio Navarese Micha Kasprzak Adam Sukiennik Jacek Kubica Andrzej Lekston Micha Hawranek Krzysztof Reczuch Marcin Gruchaa Andrzej Ochaa Wojciech Wojakowski 《Catheterization and cardiovascular interventions》2019,93(4):574-582
97.
Sáez-Cirión A Lacabaratz C Lambotte O Versmisse P Urrutia A Boufassa F Barré-Sinoussi F Delfraissy JF Sinet M Pancino G Venet A;Agence Nationale de Recherches sur le Sida EP HIV Controllers Study Group 《Proceedings of the National Academy of Sciences of the United States of America》2007,104(16):6776-6781
Some rare HIV-1-infected individuals, referred to as HIV controllers (HIC), have persistently undetectable plasma viral load in the absence of therapy. This control of HIV-1 replication has been associated with a strong, multifunctional specific CD8(+) T cell response. However, no direct link between this immune response and the control of viremia has so far been provided. We investigated parameters of specific CD8(+) T cell response and in vitro susceptibility to HIV-1 infection in 11 HIC. We found high frequencies of HIV-specific CD8(+) T cells. Interestingly, these cells expressed the activation marker HLA-DR but not CD38. This unique phenotype differentiates HIV-specific CD8(+) T cells from HIC and noncontroller subjects and likely reflects a high potential to expand upon exposure to antigen and a capacity to exert effector functions. Accordingly, although CD4(+) T cells from HIC were fully susceptible to HIV-1 superinfection, their CD8(+) T cells effectively suppressed HIV-1 infection. Remarkably, this potent anti-HIV activity was observed without prior stimulation of CD8(+) T cells. This activity was not mediated by secreted inhibitory factors but was due to the elimination of infected CD4(+) T cells and was observed only with autologous CD4(+) T cells, indicating an HLA-restricted cytotoxic mechanism. This constitutive antiviral capacity of CD8(+) T cells could account for the control of viral replication in HIC. 相似文献
98.
Autologous bone marrow (BM) cells were cultured in diffusion chambers (DC) implanted into whole-body irradiated, non-irradiated, or sham- irradiated goats. Proliferation was apparent in DC implanted in both irradiated and nonirradiated goats. However, cells in DC cultured in irradiated hosts increased in number beginning earlier, proceeded at a faster rate, and reached higher numbers than in DC in nonirradiated hosts. Growth enhancement could not have occurred as a result of radiation-induced immunosuppression in autologous hosts. The nonirradiated "target cells" in the DC therefore constituted an indicator system for stimulatory or inhibitory substances in the host. The simultaneous increase in the number of granulocytes in peripheral blood and in DC of irradiated hosts was paralleled by an initial rise in serum colony-stimulating factor (CSF). A second, prolonged period of severe granulocytopenia following irradiation of the host correlated with high levels of serum CSF. Increased numbers of megakaryocytes were seen in DC as thrombocytopenia developed in the irradiated host. DC erythropoiesis disappeared rapidly in nonirradiated goats; however, in DC of irradiated goats, the number of erythrocytic precursors increased exponentially during ablation of host erythroid marrow. Anemia did not develop in the host during the culture period. Proliferation of mononuclear cells in DC was markedly stimulated by irradiation of the host. Proliferation of macrophages appeared independent of host treatment. These observations provide strong evidence for diffusion of specific and/or nonspecific humoral hematopoietic stimulators from the host into the DC. This stimulation appears to be elicited and/or intensified by irradiation of the host. 相似文献
99.
EV Loftus Jr BA Olivares-Pakzad KP Batts MC Adkins DH Stephens MG Sarr EP DiMagno 《Gastroenterology》1996,110(6):1909-1918
BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18) 相似文献
100.
Eliano Pio Navarese Anna Szczesniak Michalina Kolodziejczak Bartosz Gorny Jacek Kubica Harry Suryapranata 《Am J Cardiovasc Drugs》2014,14(2):79-87
Statins (hydroxymethylglutaryl-coenzyme-A reductase inhibitors) are first-line agents for the management of hyperlipidemia in patients at high risk of cardiovascular (CV) events, and are the most commonly prescribed CV drugs worldwide. Although safe and generally well tolerated, there is growing evidence to suggest that statins are associated with an elevated occurrence of new-onset diabetes mellitus (DM). Recent experimental and clinical data have prompted the US Food and Drug Administration to add information to statin labels regarding the increased risk of development of type 2 DM. The main purpose of this review is to critically discuss the clinical evidence regarding the association of statin use with new-onset DM, the CV benefit/risk ratio with statins, and the rationale for individualized statin therapy. 相似文献