952 resultados para Cleaning procedures


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OBJECTIVES: Laboratory detection of vancomycin-intermediate Staphylococcus aureus (VISA) and their heterogeneous VISA (hVISA) precursors is difficult. Thus, it is possible that vancomycin failures against supposedly vancomycin-susceptible S. aureus are due to undiagnosed VISA or hVISA. We tested this hypothesis in experimental endocarditis.¦METHODS: Rats with aortic valve infection due to the vancomycin-susceptible (MIC 2 mg/L), methicillin-resistant S. aureus M1V2 were treated for 2 days with doses of vancomycin that mimicked the pharmacokinetics seen in humans following intravenous administration of 1 g of the drug every 12 h. Half of the treated animals were killed 8 h after treatment arrest and half 3 days thereafter. Population analyses were done directly on vegetation homogenates or after one subculture in drug-free medium to mimic standard diagnostic procedures.¦RESULTS: Vancomycin cured 14 of 26 animals (54%; P<0.05 versus controls) after 2 days of treatment. When vegetation homogenates were plated directly on vancomycin-containing plates, 6 of 13 rats killed 8 h after treatment arrest had positive cultures, 1 of which harboured hVISA. Likewise, 6 of 13 rats killed 3 days thereafter had positive valve cultures, 5 of which harboured hVISA. However, one subculture of vegetations in drug-free broth was enough to revert all the hVISA phenotypes to the susceptible pattern of the parent. Thus, vancomycin selected for hVISA during therapy of experimental endocarditis due to vancomycin-susceptible S. aureus. These hVISA were associated with vancomycin failure. The hVISA phenotype persisted in vivo, even after vancomycin arrest, but was missed in vitro after a single passage of the vegetation homogenate on drug-free medium.¦CONCLUSIONS: hVISA might escape detection in clinical samples if they are subcultured before susceptibility tests.

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Percutaneous ablative procedures allow curative treatment of stage BCLC 0 or BCLC A hepatocellular carcinoma, as well as liver metastases of colorectal cancer. Several methods exist including radiofrequency ablation, the most commonly used. These techniques can be used in combination with surgical excision or alone if surgery is contraindicated. They are associated with significantly reduced mortality as compared to surgery.

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This review paper reports the consensus of a technical workshop hosted by the European network, NanoImpactNet (NIN). The workshop aimed to review the collective experience of working at the bench with manufactured nanomaterials (MNMs), and to recommend modifications to existing experimental methods and OECD protocols. Current procedures for cleaning glassware are appropriate for most MNMs, although interference with electrodes may occur. Maintaining exposure is more difficult with MNMs compared to conventional chemicals. A metal salt control is recommended for experiments with metallic MNMs that may release free metal ions. Dispersing agents should be avoided, but if they must be used, then natural or synthetic dispersing agents are possible, and dispersion controls essential. Time constraints and technology gaps indicate that full characterisation of test media during ecotoxicity tests is currently not practical. Details of electron microscopy, dark-field microscopy, a range of spectroscopic methods (EDX, XRD, XANES, EXAFS), light scattering techniques (DLS, SLS) and chromatography are discussed. The development of user-friendly software to predict particle behaviour in test media according to DLVO theory is in progress, and simple optical methods are available to estimate the settling behaviour of suspensions during experiments. However, for soil matrices such simple approaches may not be applicable. Alternatively, a Critical Body Residue approach may be taken in which body concentrations in organisms are related to effects, and toxicity thresholds derived. For microbial assays, the cell wall is a formidable barrier to MNMs and end points that rely on the test substance penetrating the cell may be insensitive. Instead assays based on the cell envelope should be developed for MNMs. In algal growth tests, the abiotic factors that promote particle aggregation in the media (e.g. ionic strength) are also important in providing nutrients, and manipulation of the media to control the dispersion may also inhibit growth. Controls to quantify shading effects, and precise details of lighting regimes, shaking or mixing should be reported in algal tests. Photosynthesis may be more sensitive than traditional growth end points for algae and plants. Tests with invertebrates should consider non-chemical toxicity from particle adherence to the organisms. The use of semi-static exposure methods with fish can reduce the logistical issues of waste water disposal and facilitate aspects of animal husbandry relevant to MMNs. There are concerns that the existing bioaccumulation tests are conceptually flawed for MNMs and that new test(s) are required. In vitro testing strategies, as exemplified by genotoxicity assays, can be modified for MNMs, but the risk of false negatives in some assays is highlighted. In conclusion, most protocols will require some modifications and recommendations are made to aid the researcher at the bench. [Authors]

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Proper storage practices are critical to protect materials from intermingling, contamination, or degradation, and to maintain consistent aggregate gradation throughout a project. Concrete Paving Workforce Reference no.3

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State Highway Departments and local street and road agencies are currently faced with aging highway systems and a need to extend the life of some of the pavements. The agency engineer should have the opportunity to explore the use of multiple surface types in the selection of a preferred rehabilitation strategy. This study was designed to look at the portland cement concrete overlay alternative and especially the design of overlays for existing composite (portland cement and asphaltic cement concrete) pavements. Existing design procedures for portland cement concrete overlays deal primarily with an existing asphaltic concrete pavement with an underlying granular base or stabilized base. This study reviewed those design methods and moved to the development of a design for overlays of composite pavements. It deals directly with existing portland cement concrete pavements that have been overlaid with successive asphaltic concrete overlays and are in need of another overlay due to poor performance of the existing surface. The results of this study provide the engineer with a way to use existing deflection technology coupled with materials testing and a combination of existing overlay design methods to determine the design thickness of the portland cement concrete overlay. The design methodology provides guidance for the engineer, from the evaluation of the existing pavement condition through the construction of the overlay. It also provides a structural analysis of various joint and widening patterns on the performance of such designs. This work provides the engineer with a portland cement concrete overlay solution to composite pavements or conventional asphaltic concrete pavements that are in need of surface rehabilitation.

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The purpose of this chapter is to implement Iowa Code chapter 316 and sections 6B.42, 6B.45, 6B.54 and 6B.55, as required by the Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970, Pub. L. 91-646, as amended by the Uniform Relocation Act Amendments of 1987, Title IV, Pub. L. No. 100-17 , Sec. 104, Pub. L. 105-117, and federal regulations adopted pursuant thereto.

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The aim of this work was to use the Urinary Distress Inventory (UDI-6) and Incontinence Impact Quality of Life (IIQ-7) questionnaires to compare 3 surgical techniques for stress urinary incontinence: the transvaginal tape (TVT) (105 women), the transobturator tape outside-in (TOT) (43 women), and the transvaginal tape-obturator inside-out (TVT-O) (54 women). There were no significant differences in frequent urination, urine leakage related to the feeling of urgency, urine leakage related to physical activity, or small amounts of urine leakage. TVT-operated women had a lower percentage of micturition difficulties compared with TOT women. TVT-O-operated women described slight discomfort in the genital area compared with the TVT technique, but this difference was not significant when compared with the TOT technique. When utilizing the UDI-6 and IIQ-7 scoring modifications before and after surgery, no difference among these 3 techniques is apparent.

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Severe environmental conditions, coupled with the routine use of deicing chemicals and increasing traffic volume, tend to place extreme demands on portland cement concrete (PCC) pavements. In most instances, engineers have been able to specify and build PCC pavements that met these challenges. However, there have also been reports of premature deterioration that could not be specifically attributed to a single cause. Modern concrete mixtures have evolved to become very complex chemical systems. The complexity can be attributed to both the number of ingredients used in any given mixture and the various types and sources of the ingredients supplied to any given project. Local environmental conditions can also influence the outcome of paving projects. This research project investigated important variables that impact the homogeneity and rheology of concrete mixtures. The project consisted of a field study and a laboratory study. The field study collected information from six different projects in Iowa. The information that was collected during the field study documented cementitious material properties, plastic concrete properties, and hardened concrete properties. The laboratory study was used to develop baseline mixture variability information for the field study. It also investigated plastic concrete properties using various new devices to evaluate rheology and mixing efficiency. In addition, the lab study evaluated a strategy for the optimization of mortar and concrete mixtures containing supplementary cementitious materials. The results of the field studies indicated that the quality management concrete (QMC) mixtures being placed in the state generally exhibited good uniformity and good to excellent workability. Hardened concrete properties (compressive strength and hardened air content) were also satisfactory. The uniformity of the raw cementitious materials that were used on the projects could not be monitored as closely as was desired by the investigators; however, the information that was gathered indicated that the bulk chemical composition of most materials streams was reasonably uniform. Specific minerals phases in the cementitious materials were less uniform than the bulk chemical composition. The results of the laboratory study indicated that ternary mixtures show significant promise for improving the performance of concrete mixtures. The lab study also verified the results from prior projects that have indicated that bassanite is typically the major sulfate phase that is present in Iowa cements. This causes the cements to exhibit premature stiffening problems (false set) in laboratory testing. Fly ash helps to reduce the impact of premature stiffening because it behaves like a low-range water reducer in most instances. The premature stiffening problem can also be alleviated by increasing the water–cement ratio of the mixture and providing a remix cycle for the mixture.

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To identify the direct cost of procedures related to an outpatient chemotherapy treatment for women with breast cancer. Method: This is a quantitative research, using the case study methodology, performed in an outpatient chemotherapy of a private hospital. The total cost was calculated by multiplying the time spent by professionals involved in therapeutic procedures, the unit cost of direct labor, adding to the cost of materials, drugs and solutions. For performing the calculations, we used the Brazilian currency (R$). Results: The average total cost per chemotherapy session corresponded to R$ 1,783.01 (100%), being R$ 1,671.66 (93,75%) spent with drugs, R$ 74,98 (4.21%) with materials, R$ 28.49 (1.60%) with labor and R$ 7.88 (0.44%) with solutions. Conclusion: The results may support discussions and decision making for the management of costs related to chemotherapy aimed at reducing expenses and eliminating waste without harm to the care provided.