334 research outputs found
System insights from ‘WellAhead’
System Insights from ‘WellAhead’: A Social Innovation Lab Approach to Advance the Prioritization and Sustained Integration of Student Social and Emotional Wellbeing in K-12 Schools
ENV-641: NEW METHODS FOR DESIGN AND PERFORMANCE MONITORING OF SUB-SLAB VENTING SYSTEMS FOR VOCS AND RADON
This paper summarizes recent research funded by the U.S. Department of Defense Environmental Security Technology Certification Program (ESTCP) intended to improve the cost-effectiveness of systems to protect building occupants from subsurface radon gas and volatile organic compound (VOC) vapors. Standard practice for sub-slab depressurization (SSD) uses a fan or blower to create a measurable vacuum below the building and has not changed in a few decades. ASTM E-2121-13 specifies a minimum target vacuum of 6 to 9 Pascals (Pa) everywhere below the building floor slab, but this can be difficult to measure compared to baseline fluctuations (a signal-to-noise challenge). A key variable that is not usually measured is the permeability of the material below the floor. If granular fill is below the floor (as specified in most building codes), high flow velocities can be generated with small pressure gradients, which can protect occupants via sub-slab ventilation (SSV). Alternatively, if the floor is well sealed, the venting system may be able to capture all of the available mass of VOCs or radon at a modest flow rate, in which case mass flux might be the most important metric. Using vacuum as the only performance metric will often result in an over-designed system that is not energy efficient because it draws an excessive amount of conditioned indoor air across the floor slab for discharge above the roofline and requires excessive electricity to power fans or blowers. Research was conducted at a 64,000 ft2 (5,950 m2) commercial building with an existing SSD system comprised of 27 suction points connected to 9 fans to demonstrate and validate new methods and criteria for system optimization and monitoring, including transient and steady-state pneumatic testing and mathematical modeling using the Hantush-Jacob model, sub-slab tracer testing, building depressurization testing, trichloroethene (TCE) mass flux monitoring, and confirmatory indoor air sampling and analysis. The results of this study demonstrate that the number of SSD extraction points can be reduced substantially and still maintain health-protective indoor air quality
State of malaria diagnostic testing at clinical laboratories in the United States, 2010: a nationwide survey
<p>Abstract</p> <p>Background</p> <p>The diagnosis of malaria can be difficult in non-endemic areas, such as the United States, and delays in diagnosis and errors in treatment occur too often.</p> <p>Methods</p> <p>A nationwide survey of laboratories in the United States and its nine dependent territories was conducted in 2010 to determine factors that may contribute to shortcomings in the diagnosis of malaria. This survey explored the availability of malaria diagnostic tests, techniques used, and reporting practices.</p> <p>Results</p> <p>The survey was completed by 201 participants. Ninety percent reported that their laboratories had at least one type of malaria diagnostic test available on-site. Nearly all of the respondents' laboratories performed thick and thin smears on-site; approximately 50% had access to molecular testing; and only 17% had access to rapid diagnostic tests on-site. Seventy-three percent reported fewer than five confirmed cases of malaria in their laboratory during the 12-month period preceding the survey. Twenty-eight percent stated that results of species identification took more than 24 hours to report. Only five of 149 respondents that performed testing 24 hours a day, 7 days a week complied with all of the Clinical and Laboratory Standards Institute (CLSI) guidelines for analysis and reporting of results.</p> <p>Conclusion</p> <p>Although malaria diagnostic testing services were available to a majority of U.S. laboratories surveyed, very few were in complete compliance with all of the CLSI guidelines for analysis and reporting of results, and most respondents reported very few cases of malaria annually. Laboratories' difficulty in adhering to the rigorous CLSI guidelines and their personnel's lack of practice and proficiency may account for delays and errors in diagnosis. It is recommended that laboratories that infrequently process samples for malaria seek opportunities for practice and proficiency training annually and take advantage of available resources to assist in species identification.</p
Explicit Expression of Weighting Factor for Improved Estimation of Numerical Flux in Local-inertial Models
2-Chloro-3-[(E)-(hydrazin-1-ylidene)methyl]-6-methoxyquinoline
In the title compound, C11H10ClN3O, the quinoline ring system is essentially planar, the r.m.s. deviation for the non-H atoms being 0.014 (2) Å with a maximum deviation from the mean plane of 0.0206 (14) Å for the C atom bonded to the –CH—N=NH2 group. In the crystal, molecules are linked via N—H⋯O and N—H⋯N hydrogen bonds, forming zigzag layers parallel to (010)
The internal structure of gadolinium and perfluorocarbon-loaded polymer nanoparticles affects <sup>19</sup>F MRI relaxation times
19F magnetic resonance imaging (19F MRI) is an emerging technique for quantitative imaging in novel therapies, such as cellular therapies and theranostic nanocarriers. Nanocarriers loaded with liquid perfluorocarbon (PFC) typically have a (single) core-shell structure with PFC in the core due to the poor miscibility of PFC with organic and inorganic solvents. Paramagnetic relaxation enhancement acts only at a distance of a few angstroms. Thus, efficient modulation of the 19F signal is possible only with fluorophilic PFC-soluble chelates. However, these chelates cannot interact with the surrounding environment and they might result in image artifacts. Conversely, chelates bound to the nanoparticle shell typically have a minimal effect on the 19F signal and a strong impact on the aqueous environment. We show that the confinement of PFC in biodegradable polymeric nanoparticles (NPs) with a multicore structure enables the modulation of longitudinal (T1) and transverse (T2) 19F relaxation, as well as proton (1H) signals, using non-fluorophilic paramagnetic chelates. We compared multicore NPs versus a conventional single core structure, where the PFC is encapsulated in the core(s) and the chelate in the surrounding polymeric matrix. This modulated relaxation also makes multicore NPs sensitive to various acidic pH environments, while preserving their stability. This effect was not observed with single core nanocapsules (NCs). Importantly, paramagnetic chelates affected both T1 and T219F relaxation in multicore NPs, but not in single core NCs. Both relaxation times of the 19F nucleus were enhanced with an increasing concentration of the paramagnetic chelate. Moreover, as the polymeric matrix remained water permeable, proton enhancement additionally was observed in MRI.</p
Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.
We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies
Postprocedural CT for perivertebral cement leakage in percutaneous vertebroplasty is not necessary—results from VERTOS II
Metal-organic framework crystal-glass composites.
The majority of research into metal-organic frameworks (MOFs) focuses on their crystalline nature. Recent research has revealed solid-liquid transitions within the family, which we use here to create a class of functional, stable and porous composite materials. Described herein is the design, synthesis, and characterisation of MOF crystal-glass composites, formed by dispersing crystalline MOFs within a MOF-glass matrix. The coordinative bonding and chemical structure of a MIL-53 crystalline phase are preserved within the ZIF-62 glass matrix. Whilst separated phases, the interfacial interactions between the closely contacted microdomains improve the mechanical properties of the composite glass. More significantly, the high temperature open pore phase of MIL-53, which spontaneously transforms to a narrow pore upon cooling in the presence of water, is stabilised at room temperature in the crystal-glass composite. This leads to a significant improvement of CO2 adsorption capacity
Long-term outcomes after stenting versus endarterectomy for treatment of symptomatic carotid stenosis: the International Carotid Stenting Study (ICSS) randomised trial.
BACKGROUND: Stenting is an alternative to endarterectomy for treatment of carotid artery stenosis, but long-term efficacy is uncertain. We report long-term data from the randomised International Carotid Stenting Study comparison of these treatments. METHODS: Patients with symptomatic carotid stenosis were randomly assigned 1:1 to open treatment with stenting or endarterectomy at 50 centres worldwide. Randomisation was computer generated centrally and allocated by telephone call or fax. Major outcomes were assessed by an independent endpoint committee unaware of treatment assignment. The primary endpoint was fatal or disabling stroke in any territory after randomisation to the end of follow-up. Analysis was by intention to treat ([ITT] all patients) and per protocol from 31 days after treatment (all patients in whom assigned treatment was completed). Functional ability was rated with the modified Rankin scale. This study is registered, number ISRCTN25337470. FINDINGS: 1713 patients were assigned to stenting (n=855) or endarterectomy (n=858) and followed up for a median of 4·2 years (IQR 3·0-5·2, maximum 10·0). Three patients withdrew immediately and, therefore, the ITT population comprised 1710 patients. The number of fatal or disabling strokes (52 vs 49) and cumulative 5-year risk did not differ significantly between the stenting and endarterectomy groups (6·4% vs 6·5%; hazard ratio [HR] 1·06, 95% CI 0·72-1·57, p=0·77). Any stroke was more frequent in the stenting group than in the endarterectomy group (119 vs 72 events; ITT population, 5-year cumulative risk 15·2% vs 9·4%, HR 1·71, 95% CI 1·28-2·30, p<0·001; per-protocol population, 5-year cumulative risk 8·9% vs 5·8%, 1·53, 1·02-2·31, p=0·04), but were mainly non-disabling strokes. The distribution of modified Rankin scale scores at 1 year, 5 years, or final follow-up did not differ significantly between treatment groups. INTERPRETATION: Long-term functional outcome and risk of fatal or disabling stroke are similar for stenting and endarterectomy for symptomatic carotid stenosis. FUNDING: Medical Research Council, Stroke Association, Sanofi-Synthélabo, European Union
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