全文获取类型
收费全文 | 1170篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 6篇 |
轻工业 | 4篇 |
石油天然气 | 1篇 |
一般工业技术 | 1篇 |
冶金工业 | 1155篇 |
自动化技术 | 1篇 |
出版年
2020年 | 2篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2007年 | 1篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
1999年 | 38篇 |
1998年 | 315篇 |
1997年 | 181篇 |
1996年 | 128篇 |
1995年 | 90篇 |
1994年 | 64篇 |
1993年 | 72篇 |
1992年 | 7篇 |
1991年 | 13篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 20篇 |
1987年 | 22篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1978年 | 4篇 |
1977年 | 40篇 |
1976年 | 74篇 |
1975年 | 3篇 |
1955年 | 1篇 |
排序方式: 共有1170条查询结果,搜索用时 15 毫秒
171.
172.
GC Toner JD Shapiro CR Laidlaw D Rischin MJ Millward M Wolf H Januszewicz SV Mitchell AC Curran JP Matthews JF Bishop 《Canadian Metallurgical Quarterly》1998,16(12):3874-3879
PURPOSE: Granulocyte colony-stimulating factor (G-CSF) administered prophylactically after chemotherapy reduces the duration and severity of neutropenia. This randomized crossover study was designed to assess whether a lower dose of G-CSF is as effective as a standard dose of 5 microg/kg daily. PATIENTS AND METHODS: Patients who received standard-dose chemotherapy regimens expected to cause neutropenia received G-CSF (lenograstim) that started the day after chemotherapy for 14 days or until the absolute neutrophil count (ANC) recovered to greater than 10 x 10(9)/L. The lenograstim dose was randomly allocated to be 2 or 5 microg/kg daily in the first cycle of chemotherapy and crossed over to the alternate dose for the second cycle. The study was designed to accrue 40 assessable patients to provide a power of 80% to detect a difference in duration of neutropenia of 1 day. Fifty-two patients were randomized to treatment and 43 patients completed two cycles of identical chemotherapy. RESULTS: There was little neutropenia irrespective of the dose used. Twenty-three patients (53%) had no grade III or IV neutropenia and 30 patients (70%) had no grade IV neutropenia. Crossover trial methodology was used to assess the difference in outcome caused by the lower dose compared with the standard dose (estimated treatment effect). There was no significant difference in the measures of neutropenia, hospitalization, or other clinical outcomes. The 95% confidence interval (one-sided) for the additional duration of neutropenia caused by the lower dose of lenograstim was 0.43 days or less for grade III or IV neutropenia and 0.34 days or less for grade IV neutropenia. CONCLUSION: Lenograstim 2 microg/kg provides similar protection to 5 microg/kg against neutropenia that complicates standard-dose chemotherapy. The use of a lower dose has important implications for the cost-effectiveness of prophylactic G-CSF therapy. 相似文献
173.
174.
Healthy hair samples from golden hamsters were examined for the presence of dermatophytes and non-dermatophytes using baiting technique and direct inoculation. Thirty-four species and 2 varieties attributed to 17 genera were recovered. Paecilomyces variotii (isolated from 84.4% of the examined hair) and Aspergillus niger (81.3%) were the more frequent isolates on Sabouraud's dextrose agar (SDA) without cycloheximide. Our results have clearly demonstrated that the hair of hamster was free from true dermatophytes. Using the dilution plate method many fungal species were isolated from cage material (7 genera and 10 species + 1 variety); from faeces (10 genera and 17 species); from standard chow (3 genera and 6 species) of hamster. P. variotii which was the most frequent fungus in the preceding 3 substrates was completely absent in the presence of cycloheximide in SDA. The present study has demonstrated for the first time the isolation of Trichophyton rubrum from hamster faeces. Also, several saprophytic and cycloheximide resistant fungi were isolated. In the air of hamster cage Cladosporium cladosporioides, Penicillium chrysogenum, Alternaria alternata and Scopulariopsis brevicaulis were the most dominant species on SDA with or without cycloheximide. Using the agar diffusion method, Aloe sap, onion oil, garlic bulb extract and aqueous leaf extracts of Andropogon citratus, Euphorbia sp. and Ruta graveolens were tested for their antifungal activity on 10 fungal species. It was observed that onion oil exhibited a high inhibitory effect against most of the tested fungi. 相似文献
175.
Tissue plasminogen activator activity in the developing cerebellum, as quantified by zymography of cerebellar homogenates from embryonic day (E) 17 to adult mice, shows a peak of activity at postnatal day (P) 7, followed by a steady 75% decrease into adulthood. Northern blot analysis reveals a similar pattern for tissue plasminogen activator mRNA levels, which are low at E17 but increase dramatically, reaching their highest levels of specific mRNA/micrograms RNA in P1-P7 mice and declining about threefold in the adult mouse. In situ hybridization of whole mouse brain sections with a tissue plasminogen activator antisense cRNA probe shows pronounce reactivity in the cerebellum. Although some binding is associated with the cerebellar meninges, the external granule layer is devoid of tissue plasminogen activator mRNA at all ages. However, highly labeled elongated cells, which also bind antibody to neuronal nuclear antigen and are adjacent to Bergmann glial fibers (i.e., migrating granule neurons), are readily visible throughout the molecular and Purkinje layers at P7 and P14. In the adult mouse cerebellum, tissue plasminogen activator mRNA labeling is restricted to cells in the Purkinje/internal granule layers. Thus, tissue plasminogen activator gene expression is induced as granule neurons leave the external granule layer and begin their inward migration. 相似文献
176.
Mucin gene expression in ovarian cancers 总被引:1,自引:0,他引:1
RL Giuntoli GC Rodriguez RS Whitaker R Dodge JA Voynow 《Canadian Metallurgical Quarterly》1998,58(23):5546-5550
Ovarian cancer is a highly lethal disease with metastases present in the majority of patients at the time of diagnosis. The molecular mechanisms underlying the metastatic process of this cancer are not well understood. One family of cell-associated and secreted glycoproteins, the mucin glycoproteins, has been implicated in events leading to metastasis of several epithelial cancers including gastrointestinal and lung cancers. The purpose of this study was to characterize mucin gene expression in ovarian cancers and relate expression to tumor histology, stage, and patient survival. RNA was isolated from 29 epithelial ovarian cancers, 1 neuroendocrine carcinoma, 3 mixed mesodermal tumors, and two transformed, yet nonmalignant, ovarian epithelial cell lines. The expression of mucin genes, MUC1, 2, 3, 4, 5AC and 5B, was determined by northern analyses. Epithelial ovarian cancers expressed several mucins including MUC1, 2, 4, and 5AC; MUC3 and 5B were rarely expressed. In contrast, the transformed nonmalignant ovarian epithelial cell lines expressed only MUC1 and 5AC. Although there was no correlation of mucin expression with tumor histology, there was a significant decrease in expression of MUC3 and MUC4 with increasing cancer stage (P < 0.05). In addition, a trend toward improved patient survival occurred with increased expression of MUC4. These observations suggest a relationship between mucin gene expression and the metastatic process in epithelial ovarian cancers. Additional investigation of MUC3 and MUC4 in ovarian cancers may lead to new approaches for early detection and therapy. 相似文献
177.
JJ Berwaerts JA Verhelst GC Verhaert AA Verhaegen RE Abs 《Canadian Metallurgical Quarterly》1998,46(7):880-884
BACKGROUND: Cushing's syndrome is a rare disorder. The corticotropin (ACTH)-dependent form of this syndrome generally results either from excessive ACTH secretion by a pituitary adenoma or ectopic secretion by a malignant tumor. Theoretically, the latter type can be assumed to occur more frequently in old age as the incidence of malignancy increases. METHODS: Diagnostic procedures for these five cases of Cushing's syndrome consisted of 24-hour urinary cortisol excretion, plasma ACTH and serum cortisol levels, oCRH stimulatory test, low-dose and high-dose dexamethasone suppression tests, CT scan or MR imaging of the pituitary region, and bilateral inferior petrosal sinus sampling. Patients were treated with ketoconazole, if possible, and evaluated according to clinical response and 24-hour urinary cortisol excretion. PATIENTS: The five cases presented were selected on the basis of age--75 years or older--from a total of about 100 patients presenting with Cushing's syndrome. In only three cases were signs of hypercorticism found on clinical examination. The other two patients were evaluated for adrenocortical excess because of severe hypokalemia and the fortuitous finding of enlarged adrenal glands on CT scan, respectively. RESULTS: As a result of endocrine testing, pituitary-dependent Cushing's disease was suspected in three patients and ectopic Cushing's syndrome in two patients. Imaging techniques demonstrated only one pituitary adenoma in the first three patients and a lung tumor in one of the latter two patients. Inferior petrosal sinus sampling confirmed the suspected origin of the Cushing's syndrome in the three patients in which this procedure was performed. All three patients with pituitary-dependent Cushing's disease underwent successful clinical and biochemical treatment with ketoconazole. CONCLUSION: Pituitary-dependent Cushing's disease may occur more frequently in patients older than 75 years of age than has previously been assumed. Because surgical treatment is not always easily tolerated by older patients, the steroidogenesis inhibitor, ketoconazole, can be a valuable alternative for the control of hypercorticism. 相似文献
178.
By preserving specimens of the monogenean (platyhelminth) parasite Entobdella soleae at intervals during locomotion and processing these parasites for transmission and scanning electron microscopy, evidence was found to suggest that adhesion of the anterior pads to the skin of the host, the sole Solea solea, is brought about by interaction between the two kinds of glandular secretion supplied to the pads. It is suggested that the specialised pad tegument through which the gland cell ducts pass may be instrumental in severing the adhesive bond by dissolving the cement immediately adjacent to this tegumental surface. 相似文献
179.
JJ LaBella MJ Daood AP Koretsky BB Roman GC Sieck B Wieringa JF Watchko 《Canadian Metallurgical Quarterly》1998,84(4):1166-1173
Creatine kinase (CK) provides ATP buffering in skeletal muscle and is expressed as 1) cytosolic myofibrillar CK (M-CK) and 2) sarcomeric mitochondrial CK (ScCKmit) isoforms that differ in their subcellular localization. We compared the isometric contractile and fatigue properties of 1) control CK-sufficient (Ctl), 2) M-CK-deficient (M-CK[-/-]), and 3) combined M-CK/ScCKmit-deficient null mutant (CK[-/-]) diaphragm (Dia) to determine the effect of the absence of M-CK activity on Dia performance in vitro. Baseline contractile properties were comparable across groups except for specific force, which was approximately 16% lower in CK[-/-] Dia compared with M-CK[-/-] and Ctl Dia. During repetitive activation (40 Hz, (1)/(3) duty cycle), force declined in all three groups. This decline was significantly greater in CK[-/-] Dia compared with Ctl and M-CK[-/-] Dia. The pattern of force decline did not differ between M-CK[-/-] and Ctl Dia. We conclude that Dia isometric muscle function is not absolutely dependent on the presence of M-CK, whereas the complete absence of CK acutely impairs isometric force generation during repetitive activation. 相似文献
180.
GC du Moulin Z Pitkin YJ Shen E Conti JK Stewart C Charles D Hamilton 《Canadian Metallurgical Quarterly》1994,15(1-3):365-372
Somatic cell and gene therapy involve the application of biological technologies to an individual patient through the use of living cells which provide a therapeutic benefit (Aliski, 1991). Various forms of cellular and gene therapies are being developed and evaluated in an increasing number of clinical trials for congenital and acquired disorders. The potential and progress of these therapeutic applications have resulted in an increasing effort by the Food and Drug Administration (FDA) to develop the regulatory framework under which these therapeutic approaches would insure safety and efficacy, the primary mandate of the FDA. Over five years ago Cellcor began to define the parameters, specifications, and conditions relevant to a Quality Assurance/Quality Control (QA/QC) program that has evolved to insure safety and maximize the efficacy of applications of the company's ex vivo technology, autolymphocyte therapy. Autolymphocyte therapy is an outpatient form of somatic cell immunotherapy based upon the infusion of T cells that have been activated ex vivo using a combination of previously generated autologous cytokines and an anti-CD3 monoclonal antibody. We have been able to demonstrate the feasibility for the safe, controlled, and consistent preparation and delivery of a cellular therapy by application of relevant GMP regulations. This presentation reviews aspects of this program and chronicles our experience which at present amounts to over 4400 in fusions for over 700 patients. This program provides a high degree of assurance that a cellular therapy program can be carried out in a multisite mode involving hundreds of patients through the strict adherence to cGMP as set forth in existing regulations.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献