Supercritical fluid injection of nonvolatiles with resonant two photon ionization detection in supersonic beam mass spectrometry

Supercritical fluids of N2O and CO2 are used to solubilize nonvolatile compounds for supersonic jet expansions. R2PI is then used to ionize these compounds in a time of flight mass spectrometer. By tuning the dye laser wavelength a cold wavelength ionization spectrum can be obtained that is characteristic of that species.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87289/2/612_1.pd

Preliminary design and estimate of capital and operating costs for a production scale application of laser decontamination technology

The application of laser ablation technology to the decontamination of radioactive metals, particularly the surfaces of equipment, is discussed. Included is information related to the design, capital and operating costs, and effectiveness of laser ablation technology, based on commercial excimer and Nd:YAG lasers, for the decontamination of production scale equipment

A laser-based solution to industrial decontamination problems

The ability of lasers to deposit significant amounts of energy on surfaces located at large distances from the laser can be exploited to solve very difficult industrial problems. The Ames Laboratory has been working in partnership with Lockheed Martin Idaho Technologies (LMIT) to apply laser technologies to the decontamination of radioactively contaminated surfaces located in hostile environments. Many such applications exist within former USDOE and nuclear industry facilities. As opposed to laser coating removal systems, which are designed to ``strip`` relatively soft coatings from a substrate without damage to the substrate, the system being developed by Ames - LMIT is designed to remove contaminants that are embedded within the metal surface itself. The system generates irradiance levels sufficient to remove microns of metal from a surface and an off-gas system that prevents the redeposition of materials removed from the surface. Process control is assisted by monitoring the laser-generated plasma produced during laser surface ablation. Results achieved using this apparatus for various metal types will be presented along with a discussion of other potential industrial applications

Supercritical fluid jet expansions of polar aromatic carboxylic acids using simple derivatization with detection by resonant two-photon ionization

In this work simple derivatization is used as a means of enhancing the solubility of polar aromatic carboxylic acids in supercritical CO2 and N2O. The supercritical fluid is then expanded from 200 atm and 40[deg]C through a pulsed injection orifice into vacuum as a supersonic jet for analysis by laser resonant two-photon ionization spectroscopy in a time-of-flight mass spectrometer. The use of derivatization reduces the polarity of these carboxylic acids and thus greatly enhances their solubility in these fluids. The result is that strong ionization signals from the jet are detected in the mass spectrometer at relatively low temperatures where these molecules, many of which are thermally labile, will not decompose. The laser ionization method allows soft ionization of these compounds where the molecular ion is generally the base peak and a characteristic fragment due to simple C[alpha]-C[beta] cleavage is often observed. By monitoring the molecular ion as a function of wavelength a cold laser ionization spectrum with sharp spectral features can be obtained in these supersonic expansions from high pressure supercritical fluids thus demonstrating that optical selectivity is still retained even after derivatization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27585/1/0000629.pd

QoS routing with link stability in mobile ad hoc networks

Abstract. In this paper, in accordance with requirements of different users and supplying effective usage of limited network resources, we propose a stable QoS routing mechanism to determine a guaranteed route suited for mobile ad hoc wireless networks. The manner exploits the received signal strength (RSS) techniques to estimate the distance and the signal change of the velocity to evaluate the breakaway. To ensure the QoS it chooses a steady path from the source to the destination and tries to reserve the bandwidth. Ultimately, it is clear to find that the performance never decrease even the growth of the overhead and the movement of users via the simulated by ns-2. Introduction Mobile Ad Hoc Wireless Networks (MANET), also called the Ad hoc network, is lots of moving nodes (mobile hosts) communicating with their adjacent mobile node by radio wave. Every node can contact each other without existence infrastructural network. In the Ad hoc network, it differs from cellular wireless networks that need base stations to deliver and receive the packets. Each node plays the role as a router. When one of them wants to deliver packets to destination out of its coverage, intermediate nodes will forward this packet to the next node till the destination node receive it. In traditional cellular wireless networks, generally we need to establish base stations in advance. Fixed nodes far and near connect to the backbone and become a wireless network environment. In this network the customer who wants to communicate with another must locate in the base station coverage. If user moved out of base station's service scope, he can't take the communication. Consequently, we need to establish enough base stations to achieve the objective. Ad hoc networks do not demand fixed network infrastructures and centralized management mechanisms, as well as can be built anytime, anywhere rapidly. Ad hoc networks also have the feature of self-creating, self-organization and elf-management as well as deploy and remove network easily. Ad hoc network has above advantages. However, the Ad hoc network environment has the following restricts [1], including of Network topology instable, Limited energy constrained and Limited network bandwidth-constrained QoS Routing with Link Stability in Mobile A

Sociocultural influences on asthma self-management in a multicultural society:a qualitative study amongst Malaysian adults

Abstract Background Supported self‐management improves asthma outcomes, but implementation requires adaptation to the local context. Barriers reported in Western cultures may not resonate in other cultural contexts. We explored the views, experiences and beliefs that influenced self‐management among adults with asthma in multicultural Malaysia. Methods Adults with asthma were purposively recruited from an urban primary healthcare clinic for in‐depth interviews. Audio‐recordings were transcribed verbatim and analysed thematically. Results We interviewed 24 adults. Four themes emerged: (1) Participants believed in the ‘hot and cold’ concept of illness either as an inherent hot/cold body constitution or the ambient temperature. Hence, participants tried to ‘neutralize’ body constitution or to ‘warm up’ the cold temperature that was believed to trigger acute attacks. (2) Participants managed asthma based on past experiences and personal health beliefs as they lacked formal information about asthma and its treatment. (3) Poor communication and variable advice from healthcare practitioners on how to manage their asthma contributed to poor self‐management skills. (4) Embarrassment about using inhalers in public and advice from family and friends resulted in a focus on nonpharmacological approaches to asthma self‐management practice. Conclusions Asthma self‐management practices were learnt experientially and were strongly influenced by sociocultural beliefs and advice from family and friends. Effective self‐management needs to be tailored to cultural norms, personalized to the individuals' preferences and clinical needs, adapted to their level of health literacy and underpinned by patient–practitioner partnerships. Patient and Public Contributions Patients contributed to data. Members of the public were involved in the discussion of the results

Population genomic analyses of protected incense trees Aquilaria sinensis reveal the existence of genetically distinct subpopulations

The incense tree Aquilaria sinensis (Thymelaeaceae) can produce agarwood with commercial values and is now under threat from illegal exploitation in Hong Kong, impairing the local population and biodiversity. Together with other species of Aquilaria, it is listed in the CITES Appendix II, which strictly regulates its international trade. To understand the population structure of A. sinensis and to make relevant conservation measures, we have sequenced 346 individuals collected in Hong Kong and southern mainland China. Population genomic analyses including principal component analysis, neighbor-joining tree construction, ADMIXTURE, and hierarchical pairwise-FST analyses suggested that genetically distinct populations are contained in certain areas. Genomic scan analyses further detected single-nucleotide polymorphism (SNP) outliers related to plant defense, including the CYP71BE gene cluster. In addition to the population analyses, we have developed a modified hexadecyltrimethyl-ammonium bromide (CTAB) DNA extraction protocol for obtaining DNA from agarwood samples in this study, and resequencing of DNA extracted from two agarwood samples using this method allows us to successfully map to the sample corresponding localities in the phylogenetic tree. To sum up, this study suggested that there is a genetically distinct subpopulation of incense tree in Hong Kong that would require special conservation measures and established a foundation for future conservation measures

Comparison of depressive symptoms among healthcare workers in high-risk versus low-risk areas during the first month of the COVID-19 pandemic in China

IntroductionThe psychological health of healthcare workers (HCWs) has become a significant concern, particularly during the initial stage of a pandemic. This study compared the depressive symptoms among HCWs in high-risk areas (HRAs) and low-risk areas (LRAs) with matching demographics.MethodsA cross-sectional study was employed to compare the depressive symptoms (Patient Health Questionnaire score ≥ 10), workplace environment characteristics, the Health Belief Model (HBM) and socio-demographics of the HCWs working in HRAs and LRAs in several accessible regions (mainly Hubei Province and Guangdong–Hong Kong–Macao Greater–Bay–Area) in China. Eight hundred eighty-five HCWs were recruited for unmatched analysis between March 6 and April 2, 2020. After matching with occupation and years of service using a 1:2 ratio, 146 HCWs in HRAs and 290 HCWs in LRAs were selected for matched analysis. Subgroup analyzes were performed using two individual logistic regressions to delineate the associated factors in LRAs and HRAs, respectively.ResultsHCWs in LRAs (Prevalence = 23.7%) had 1.96 times higher odds of depressive symptoms than those in HRAs (Prevalence = 15.1%) after adjusting for occupation and years of service (p < 0.001). Significant differences in workplace environment characteristics (p < 0.001) and the 5-dimension of the HBM of HCWs (p < 0.001 to p = 0.025) were found between HRAs and LRAs.Logistic regression showed that workers with years of service between 10 and 20  years (OR:6.27), ever had contact with COVID-19 patients (OR:14.33) and had higher scores of “perceived barrier” of HBM (OR:4.48) predicted depressive symptoms in HRAs while working in pneumology departments and infectious disease units (OR:0.06), and high “self-efficacy” in the HBM (OR:0.13) was a protective factor against depressive symptoms.Contrarily, in LRAs, those HCWs who worked in ICUs (OR:2.59), had higher scores of “perceived susceptibility toward the COVID-19 outbreak” (OR:1.41), “perceived severity of the pandemic” (OR:1.25), and “perceived barriers of wearing masks” (OR:1.43) in the HBM predicted depressive symptoms. High “cues to action” (OR:0.79), and better “knowledge” (OR:0.79) in the HBM were protective factors against depressive symptoms.ConclusionThe risk of depressive symptoms of HCWS was double in LRAs than in HRAs in the first month of the COVID-19 pandemic. Furthermore, salient predictors for depressive symptoms among HCWs in HRAs and LRAs were very different

Feasibility of supported self-management with a pictorial action plan to improve asthma control

Supported self-management reduces asthma-related morbidity and mortality. This paper is on a feasibility study, and observing the change in clinical and cost outcomes of pictorial action plan use is part of assessing feasibility as it will help us decide on outcome measures for a fully powered RCT. We conducted a pre–post feasibility study among adults with physician-diagnosed asthma on inhaled corticosteroids at a public primary-care clinic in Malaysia. We adapted an existing pictorial asthma action plan. The primary outcome was asthma control, assessed at 1, 3 and 6 months. Secondary outcomes included reliever use, controller medication adherence, asthma exacerbations, emergency visits, hospitalisations, days lost from work/daily activities and action plan use. We estimated potential cost savings on asthma-related care following plan use. About 84% (n = 59/70) completed the 6-months follow-up. The proportion achieving good asthma control increased from 18 (30.4%) at baseline to 38 (64.4%) at 6-month follow-up. The proportion of at least one acute exacerbation (3 months: % difference −19.7; 95% CI −34.7 to −3.1; 6 months: % difference −20.3; 95% CI −5.8 to −3.2), one or more emergency visit (1 month: % difference −28.6; 95% CI −41.2 to −15.5; 3 months: % difference −18.0; 95% CI −32.2 to −3.0; 6 months: % difference −20.3; 95% CI −34.9 to −4.6), and one or more asthma admission (1 month: % difference −14.3; 95% CI −25.2 to −5.3; 6 months: % difference −11.9; 95% CI −23.2 to −1.8) improved over time. Estimated savings for the 59 patients at 6-months follow-up and for each patient over the 6 months were RM 15,866.22 (USD3755.36) and RM268.92 (USD63.65), respectively. Supported self-management with a pictorial asthma action plan was associated with an improvement in asthma control and potential cost savings in Malaysian primary-care patients. Trial registration number: ISRCTN87128530; prospectively registered: September 5, 2019, http://www.isrctn.com/ISRCTN87128530