全文获取类型
收费全文 | 175篇 |
免费 | 0篇 |
学科分类
工业技术 | 175篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 30篇 |
1997年 | 14篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有175条查询结果,搜索用时 15 毫秒
61.
62.
Rich D.A. Carroll M.S. Frei M.R. Ivanov T.G. Mastrapasqua M. Moinian S. Chen A.S. King C.A. Harris E. De Blauwe J. Hong-Ha Vuong Archer V. Ng K. 《Microwave Magazine, IEEE》2002,3(2):44-55
As process technology advances, we will see SoC systems with millions of digital gates combined with RF circuits operating in the tens of GHz 相似文献
63.
Cervical lymphadenitis and lymphadenopathy are common in children and may be caused by local or systemic infection. There are a large number of possible etiologies. We report the case of a five-year-old boy with unilateral cervical lymphadenitis who was in good health and showed neither clinical nor laboratory signs of systemic infection. Despite repetitive empirical antimicrobial treatment, the lymph nodes increased in size. After surgical excision Mycobacterium malmoense grew from the lymph node culture. Based on a literature search (Embase and Medline 1980-1992), the most frequent infectious etiologies of pediatric cervical lymphadenitis and lymphadenopathies are summarized. Nontuberculous mycobacterial lymphadenitis is most frequent in children between one and five years of age, and is more common in girls than boys. The treatment of choice is surgical excision. In immunocompetent children treatment with antimycobacterial drugs is not needed even if relapse occurs. 相似文献
64.
65.
A J?rres TO Bender A Finn J Witowski S Fr?hlich GM Gahl U Frei H Keck J Passlick-Deetjen 《Canadian Metallurgical Quarterly》1998,54(6):2184-2193
BACKGROUND: Conventional peritoneal dialysis fluids (PDF) have been shown to compromise the function of both leukocytes and human peritoneal mesothelial cells (HPMC). Various in vitro studies have identified the low initial pH in combination with high lactate content, as well as the hyperosmolality and high glucose concentration present in currently used solutions as the primary determinants of their bioincompatibility. Bicarbonate buffered PDF (at neutral pH) display improved in vitro biocompatibility as compared to conventional, lactate buffered PDF. However, little information is currently available regarding the potential impact of PDF on the function of human peritoneal fibroblasts (HPFB), the major cell population present in peritoneal interstitium. METHODS: The current study compares the effect of bicarbonate and lactate buffered PDF in a model system of resting peritoneal mesothelial cells and fibroblasts cultured from human omentum. Interleukin-1 beta-stimulated IL-6 release from HPMC and HPFB was used as the cell functional parameter. RESULTS: While short (30 min) pre-exposure to lactate buffered PDF significantly reduced the IL-1 beta-stimulated IL-6 release from HPMC during a subsequent recovery period (24 hr), a significant decrease in HPMC IL-6 secretion with bicarbonate buffered PDF was only observed after prolonged (> or = 60 min) exposure. In contrast, no significant IL-6 inhibition was detected with HPFB pre-exposed to PDF for up to 90 minutes. A significant suppression of HPFB IL-6 secretion was only observed in coincubation experiments (24 hr) with dilutions of both types of PDF. CONCLUSIONS: These results indicate that (i) bicarbonate buffered PDF are less inhibitory to peritoneal cell function as compared to conventional, lactate buffered PDF; and (ii) HPFB may be more resistant than HPMC to bioincompatible PDF. 相似文献
66.
U Malipiero K Frei KS Spanaus C Agresti H Lassmann M Hahne J Tschopp HP Eugster A Fontana 《Canadian Metallurgical Quarterly》1997,27(12):3151-3160
The expression and action of Fas/Fas ligand (FasL) in multiple sclerosis has been postulated as a major pathway leading to inflammatory demyelination. To formally test this hypothesis, C57BL/6-lpr and -gld mice, which due to gene mutation express Fas and FasL in an inactive form, were immunized with myelin oligodendrocyte glycoprotein peptide(35-55). Whereas in wild-type C57BL/6 mice, experimental autoimmune encephalomyelitis (EAE), was chronic/relapsing, EAE in lpr and gld mice was characterized by a lower incidence of disease and a monophasic course. This contrasts with C57BL/6 perforin knockout mice, which showed the most severe form of EAE of all mouse strains tested, the course being chronic relapsing. The difference noted cannot be attributed to an involvement of FasL in oligodendrocyte damage since oligodendrocytes are insensitive to FasL-mediated cytotoxicity in vitro, and since in the acute phase of EAE gld mice also show CD4+ T cell infiltrates with associated demyelination in brain and spinal cord. Unlike oligodendrocytes, astrocytes were killed by FasL in vitro. It remains to be established whether this latter finding explains the different disease course of lpr and gld mice compared to wild-type and perforin knockout mice. 相似文献
67.
In 1992, the Swiss helicopter rescue service (REGA) transported 515 injured and 141 sick children (total n = 656). More than 60% of the children were boys; the age group from 10 to 16 years dominated. Primary care was provided in 415 of the flights, whereas the remaining cases were interhospital transfers to institutions with pediatric intensive care units. The main reason for primary interventions was sports accidents, followed by medical disease and traffic accidents. The majority of the sick children (70%) were severely ill with life-threatening diseases according to National Advisory Committee for Aeronautics (NACA) indices IV to VII. On the other hand, only 47% of the injured children had NACA indices of IV to VII. Most of these children had minor injuries suffered during sports activities; they were rescued mainly because of the site of the accident and not the severity of the injury. The remaining trauma victims had had traffic or home accidents and were usually severely injured. Head injuries were the most common reason for intervention due to accidents, and central nervous disorders and respiratory problems were the main reason for interventions in children suffering from serious illnesses. For primary REGA rescue interventions, the mean time from accident to arrival at the hospital was 64 minutes: 18 minutes from injury to alarm, 17 minutes from alarm to arrival at the scene, and 29 minutes for scene time and flight to the hospital. Costs for helicopter rescue are twice as high as for ground-based rescue (ambulance). However, considering the relatively high percentage of severely injured or life-threatened sick children involved, air rescue and its higher costs appear to be justified. 相似文献
68.
The effects of peritonsillar injections of epinephrine and local anesthetics before tonsillectomy on blood loss and postoperative pain were evaluated in a prospective, randomized double-blind trial on 103 children. Patients were randomly assigned into one of three groups: controls given injections of 0.9% NaCl (n = 34), patients injected with 0.4 ml/kg (1:200,000) epinephrine combined with 0.25% bupivacaine (n = 33) and patients given only 1:200,000 epinephrine (n = 36). All injections and operations were performed by the same surgeon (KS). Blood loss was calculated by weighing all blood aspirated perioperatively and swabs used during surgery. Postoperative pain was assessed at regular intervals by using three methods: (1) use of a visual analogue scale by parents and nurses to estimate pain; (2) postoperative need for nalbuphine as analgesic; (3) the Hannallah-Broadman semi-objective pain score (including crying, anxiety, restlessness, and changes in blood pressure). The mean blood loss in the control group (given NaCl) was 132 g, which was significantly increased when compared with the epinephrine/bupivacaine group (85 g) and the group treated with only epinephrine (90 g). However, analysis of the postoperative pain scores did not reveal any significant differences among groups. These findings indicate that the peritonsillar injection of bupivacaine does not decrease postoperative pain, but peritonsillar injections of epinephrine will significantly reduce blood loss during tonsillectomy. 相似文献
69.
To elucidate the role of bradykinin in the complex pathophysiology of bacterial meningitis we investigated the effect of the bradykinin B2 receptor antagonist Hoe140, icatibant (D-Arg[Hyp3-Thi5-D-Tic7-Oic8]-bradykinin), on pathophysiological alterations in experimental pneumococcal meningitis. Untreated rats injected intracisternally (i.c.) with heat-killed pneumococci developed an increase of regional cerebral blood flow (185.4 +/- 27.4%, baseline 100%, mean +/- S.D.), brain water content (79.16 +/- 0.23%), intracranial pressure (21.4 +/- 6.0 mm Hg), and white blood cell count in the cerebrospinal fluid (CSF) (4621 +/- 1894 cells/microliter) within 6 h after i.c. challenge. Treatment with Hoe140 (0.1 mg/kg i.v. at baseline and 0.05 mg/kg s.c. at 2 h after i.c. challenge) attenuated the increase of brain water content (78.53 +/- 0.28%; P < 0.05), intracranial pressure (7.5 +/- 2.2 mm Hg; P < 0.05), and regional cerebral blood flow (128.6 +/- 23.1%; P < 0.05), and reduced CSF pleocytosis (2690 +/- 1898 cells/microliter. N.S.). When treatment was started 4 h after i.c. challenge Hoe140 reduced intracranial pressure (P < 0.05), but was no more capable to significantly influence the other pathophysiological parameters. Treatment with lower (0.01 mg/kg i.v. at baseline, followed by 0.005 mg/kg s.c. at 2 h) and higher (2 mg/kg i.v., followed by 1 mg/kg s.c. at 2 h) concentrations of Hoe140 was ineffective. Likewise, i.c. injection of Hoe140, at different dosages (4 nmol, 40 nmol, 400 nmol) did not significantly alter the pathophysiological parameters in pneumococci-induced meningitis, but caused changes in mean arterial blood pressure at dosages greater than 4 nmol. We conclude that bradykinin is involved as an inflammatory mediator of microvascular changes, brain edema, and increased intracranial pressure during the early phase of experimental pneumococcal meningitis. 相似文献
70.
B Kreft S Ilic W Ziebuhr A Kahl U Frei K Sack M Trautmann 《Canadian Metallurgical Quarterly》1998,13(12):3160-3164
BACKGROUND: Peritoneal catheter exit-site infections cause a relevant morbidity in peritoneal dialysis patients and are frequently caused by Staphylococcus aureus. We tested the hypothesis that adherence of exit-site-derived S. aureus to epithelial cells and peritoneal catheter silicone tubes discriminates virulent and less virulent strains. METHODS: The binding of isolated S. aureus to an epithelial cell line (HEp-2) and to silicone tubes was analyzed using light-microscopy or radioactive labeling of bacteria. RESULTS: Of 378 exit-site swabs, 99 (26%) were positive for microbial growth. S. aureus was cultured in 25 of 99 positive swabs; three of 13 swabs taken in exit-site infections grade 3 and 4 that had tested positive for S. aureus. Adherence of S. aureus from exit-site infections grade 2, 3 and 4 to Hep-2 cells did not differ from adherence of bacteria isolated from asymptomatic or moderately inflamed catheter exit sites (grade 0-2). However, binding of S. aureus to silicone tubes was enhanced in grade 0/1 compared with grade 2-4 exit-site isolates. CONCLUSIONS: Staphylococcus aureus is an important pathogen in CAPD-related exit-site infection being isolated in about 6.6% of all exit-site swabs (and in 25% of all positive swabs). Silicone-adhesive strains may be of more clinical significance in peritoneal dialysis patients since adhesion to silicone was increased in S. aureus strains isolated in more severe exit-site infections. 相似文献