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排序方式: 共有179条查询结果,搜索用时 15 毫秒
71.
72.
S Harthug N Langeland A Digranes GS Simonsen O Olsvik A Sundsfjord OB Nat?s E Haarr P Gaustad EA H?iby PL Svarva 《Canadian Metallurgical Quarterly》1998,118(26):4070-4073
During the last decade antimicrobial resistant pathogens have become a major medical problem. Internationally, multiresistant enterococci have increased nosocomial morbidity and mortality. Such strains are often resistant to ampicillin, aminoglycosides, and glycopeptides such as vancomycin. The spread of these strains has been shown to correlate to the use of antibiotics and the practice of suboptimal infection control within health care facilities. The current situation in Norwegian hospitals is presented, including the only six cases with infections and the three carriers of vancomycin resistant enterococci found to date. Surveillance in the hospitals shows that such strains are uncommon in non-infected patients. To maintain this favourable situation it is necessary to continue to practice effective methods of infection control and to employ sound antibiotic policies. 相似文献
73.
Silva Edson Fidalgo Robson Ferro Márcio Franco Natália 《Software and Systems Modeling》2023,22(4):1217-1249
Software and Systems Modeling - Structured query language (SQL) is a widely used language for accessing both relational and non-relational databases. SQL is the standard form of access in... 相似文献
74.
Pansonato N Afonso MV Salles CA Boncz MA Paulo PL 《Water science and technology》2011,64(5):1178-1185
SODIS (solar disinfection) is a low-cost alternative for water decontamination. The method is based on the exposure of water, contained in PET bottles, to direct sunlight, and mainly its UV-A and infrared components. The present research studied SODIS as a low cost alternative for the inactivation of Escherichia coli (E. coli) in treated greywater, aiming at its reuse for more noble applications. Experiments were performed in (i) batch mode (2 L PET-bottles), testing the effect of turbidity on system efficiency and, (ii) in a continuous pilot-scale reactor prototype (51 L, using interconnected 2 L-PET bottles), testing hydraulic retention times (HRT) of 18 and 24 h. Samples were exposed to an average solar radiation intensity of 518 W/m2. The results obtained indicate that the SODIS system has potential for total coliforms and E. coli inactivation in the pre-treated greywater, reaching 2.1 log units E. coli inactivation in batch experiments for low turbidity samples (21 NTU), and > 2 log units inactivation of total coliforms (and E. coli, when present) for the 24 h HRT-continuous prototype. The continuous flow prototype needs more testing and structural improvements to cope with the difficulties posed by algae growth, as they complicate maintaining conditions of constant flow and make frequent maintenance inevitable. 相似文献
75.
Recovery of valuable elements from spent Li-batteries 总被引:5,自引:0,他引:5
This work examines two recycling processes for spent Li/MnO2 and Li-ion batteries. The anode, cathode and electrolyte (LiPF6) were submitted to one of the following procedures: (a) calcination at 500 °C (5 h) followed by solvent extraction to recover lithium salts (fluoride, phosphate) in good yield (90 wt%). The residual solid was treated with H2SO4 containing H2O2 and on evaporation gave high purity grade cobalt or manganese sulfate; (b) fusion with KHSO4 (500 °C, 5 h). The resulting aqueous solution was added dropwise to a solution of NaOH, giving cobalt or manganese as impure precipitate. Addition of KF precipitated high purity grade LiF in moderate yield (50 wt%). The final aqueous solution on treatment with calcium sulfate precipitated the corresponding phosphate and fluoride salts. 相似文献
76.
Nat Vorayos Nakorn Tippayawong Bancha Thanapiyawanit 《Journal of Mechanical Science and Technology》2008,22(5):973-980
Enhancement of thermal performance in an incinerator and flue gas treatment with a randomly packed bed of uniform spheres
was investigated in a custom-made experimental facility and reported in the present paper. Pressure drop, temperature evolution
and heat transfer characteristics were evaluated for a range of superficial velocities, Reynolds numbers and bed geometries.
Results revealed that increases in both superficial velocity and bed thickness caused a rise in pressure drop across the packed
bed in similar fashion to the Ergun equation but with different coefficients at low Reynolds number between 60–300. The two
constants were empirically determined to be 68.5 and 4.95. It was also found that the packed bed affects axial temperature
distribution from the incinerator chamber to stack. For the same heating rate, higher temperature was achieved in the chamber
with the packed bed, and peak temperature was reached at a rate of 7–10% faster than that without the packed bed during the
startup period.
The downstream side of the thicker bed appeared to have lower temperature than the thinner bed for the same axial position,
demonstrating less flue loss during the transient state. The incinerator chamber proved to have higher temperature rising
rate and reached higher maximum temperature with the presence of the packed bed. 相似文献
77.
Mélanie Fonte Natália Tassi Dr. Diana Fontinha Inés Bouzón-Arnáiz Dr. Ricardo Ferraz Prof. Maria J. Araújo Dr. Xavier Fernàndez-Busquets Dr. Miguel Prudêncio Prof. Paula Gomes Dr. Cátia Teixeira 《ChemMedChem》2021,16(5):788-792
Multi-stage drugs have been prioritized in antimalarial drug discovery, as targeting more than one process in the Plasmodium life cycle is likely to increase efficiency, while decreasing the chances of emergence of resistance by the parasite. Herein, we disclose two novel acridine-based families of compounds that combine the structural features of primaquine and chloroquine. Compounds prepared and studied thus far retained the in vitro activity displayed by the parent drugs against the erythrocytic stages of chloroquine-sensitive and -resistant Plasmodium falciparum strains, and against the hepatic stages of Plasmodium berghei, hence acting as dual-stage antiplasmodial hits. 相似文献
78.
Ricardo Marques E Silva Anderson Thesing Vinicius Gonçalves Deon Alice Gonçalves Osório Bruno da Silveira Noremberg Natália Hadler Marins Marcelo Ornaghi Orlandi Fabiana Villela da Motta Rubens Maribondo do Nascimento Neftali Lenin Villarreal Carreño 《Bulletin of Materials Science》2017,40(3):499-504
The aim of this work was to prepare a flexible nanocomposite from ultra-fine titanium oxide (\(\hbox {TiO}_{2}\)) growth on carbon fibre via microwave-assisted hydrothermal synthesis (MHS) and to evaluate its photocatalytic properties. The \(\hbox {TiO}_{2}\) nanoparticles were directly grown on the carbon fibre (CF). Thus, a study comparing the conventional titania coating vs. the MHS were performed. The significant layer interaction as a function of the coating method on the visible and dark dye photodegradation performance was observed. Techniques such as X-ray diffraction, electron microscopy (field-emission scanning electron microscope (FESEM)), Raman spectroscopy, among others were used aiming to characterize the different route samples. This study reports a reproducible and single method to manufacture of nanocomposites through the growth of \(\hbox {TiO}_{2}\) nanoparticle on CF by MHS that allow controlling the thickness layer. Similar procedure of synthesized nanocomposite could be applied in different chemical compositions to advanced applications, based on the electrochemical nanostructure. 相似文献
79.
Understanding the Rate‐Limiting Step of Glycogenolysis by Using QM/MM Calculations on Human Glycogen Phosphorylase
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Dr. Natércia F. Brás Prof. Pedro A. Fernandes Prof. Maria J. Ramos 《ChemMedChem》2018,13(15):1608-1616
Liver glycogen phosphorylase (GP) is a key enzyme for human health, as its increased activity is associated with type 2 diabetes. The GP catalytic mechanism has been explored by quantum mechanics/molecular mechanics (QM/MM) methods. Herein, we propose a mechanism that proceeds by three steps: 1) it begins with transfer of a hydrogen atom from the phosphate group of the pyridoxal 5′‐phosphate (HPO42?‐PLP) cofactor to the phosphate substrate; 2) the glycosidic linkage is then cleaved through protonation of the glycosidic oxygen atom by a hydroxy group of the inorganic phosphate group; and 3) an oxygen atom of the phosphate performs a nucleophilic attack on the anomeric carbon atom of glucose, concomitant with the return of a proton from phosphate to PO43?‐PLP, which finally leads to formation of the glucose‐1‐phosphate product and recovers the initial state of the PLP cofactor. The glycosidic bond cleavage and nucleophilic attack from the phosphate group to the glycosyl molecule have the highest activation free energies. The structural properties of the hereby characterized transition states could be very useful in structure‐based drug design studies against liver GP. 相似文献
80.
Nat Alcock 《Vernacular Architecture》2018,49(1):44-57
The Manoir de la Haule at Aclou was described by Bans, Gaillard-Bans and Smith in 1995 as having a base-cruck hall.1 The roof has now been dated to 1360–1d, and study has shown that it is of short-principal rather than base-cruck form. The structure is described in detail and the historical evidence re-examined, suggesting a scenario for its construction. English and French parallels for the plan and structure of the house are considered; it is clear that the design of the house is English, but some details suggest the involvement of French carpenters in its construction. 相似文献