393 research outputs found
Integrated waveguide and nanostructured sensor platform for surface-enhanced Raman spectroscopy
Limitations of current sensors include large dimensions, sometimes limited sensitivity and inherent single-parameter measurement capability. Surface-enhanced Raman spectroscopy can be utilized for environment and pharmaceutical applications with the intensity of the Raman scattering enhanced by a factor of 106. By fabricating and characterizing an integrated optical waveguide beneath a nanostructured precious metal coated surface a new surface-enhanced Raman spectroscopy sensing arrangement can be achieved. Nanostructured sensors can provide both multiparameter and high-resolution sensing. Using the slab waveguide core to interrogate the nanostructures at the base allows for the emission to reach discrete sensing areas effectively and should provide ideal parameters for maximum Raman interactions. Thin slab waveguide films of silicon oxynitride were etched and gold coated to create localized nanostructured sensing areas of various pitch, diameter, and shape. These were interrogated using a Ti:Sapphire laser tuned to 785-nm end coupled into the slab waveguide. The nanostructured sensors vertically projected a Raman signal, which was used to actively detect a thin layer of benzyl mercaptan attached to the sensors
Diversification: A Sharia Effect? Some Evidence from Malaysia
AbstractThis study compares the effect of diversification between the Sharia and non-Sharia stocks listed on Bursa Malaysia during the period January 2002 to April 2014. The standard deviations of stock portfolios were calculated for the entire and two market phase defined bull and bear periods. Independent samples T-test indicated that there is significant difference in standard deviation between Sharia and non-Sharia portfolios for the bear and first bull period with no significant difference in the entire and second bull period. It can be concluded that portfolio diversification applies in both Sharia and non-Sharia compliant stocks of the Malaysian stock market. In addition, Sharia compliant stocks required a smaller number of stocks in a portfolio to reduce specific amount of risk
Vision improvement in a Taiwanese (Han Chinese) family with Leber's hereditary optic neuropathy
AbstractIn this report, we describe a Taiwanese (Han Chinese) family with Leber's hereditary optic neuropathy. The family carried a mitochondrial DNA mutation (mtDNA m.14484T>C) associated with spontaneous visual improvement. A 15-year-old boy from this family was diagnosed with Leber's hereditary optic neuropathy 6 months after losing his vision. His vision recovered after 8 months of supportive treatment. His mother, older brother, and two sisters also had the same mutation and had previously experienced vision loss. In this family, there was no male predominance
Disparities in Prostate Cancer Survival in Appalachian Kentucky: A Population-Based Study
Introduction: Prostate cancer (PC) is the most common male cancer in the USA. When comparing the incidence and mortality rates of PC, the Surveillance Epidemiology and End Results data of 2005–2014 show that Appalachian Kentucky had a lower incidence (113/100 000 v 137/100 000) but a higher mortality rate (23.8% v 21.8%) when compared to non-Appalachian Kentucky. The aim of this study was to further characterize the survival disparities of PC between Appalachian and non-Appalachian Kentucky.
Methods: All stages of PC patients diagnosed between 2007 and 2011 were collected through the Kentucky Cancer Registry. Baseline characteristics and survival outcomes were compared between Appalachian Kentucky and non-Appalachian Kentucky, using Pearson χ2 and Cox regression analyses in this population-based analysis.
Results: Of 12 871 patients studied, 3482 (26.8%) were from Appalachian Kentucky whereas 8489 (73.2%) were from non-Appalachian Kentucky. Caucasians predominated in both groups. Most Appalachian Kentucky patients were aged 65–74 years. Appalachian Kentucky patients had a higher Gleason score, higher prostate specific antigen (PSA), more aggressive histologic grade, more distant disease, higher comorbidity score, lower education, and higher poverty compared to patients from non-Appalachian Kentucky. There was a 5-year survival difference between Appalachian Kentucky and non-Appalachian Kentucky in unadjusted analysis (p \u3c 0.001) that disappeared after adjusting with Cox regression analysis (p = 0.4). However, worsened survival was still seen with higher Gleason score, higher PSA, distant stage disease, higher Charlson comorbidity index, and very low high school education (p \u3c 0.001).
Conclusion: In this population-based analysis, this study shows a significant difference in PC survival between Appalachian and non-Appalachian Kentucky. The difference was not related to geographic location, but rather to high comorbidity score, high poverty rate, and low education. Additional research is needed to understand the healthcare restraints for Appalachian Kentucky
Accidents preventive practice for high-rise construction
The demand of high-rise projects continues to grow due to the reducing of usable land area in Klang Valley, Malaysia.The rapidly development of high-rise projects has leaded to the rise of fatalities and accidents.An accident that happened in a construction site can cause serious physical injury.The accidents such as people falling from height and struck by falling object were the most frequent accidents happened in Malaysian construction industry.The continuous growth of high-rise buildings indicates that there is a need of an effective safety and health management. Hence, this research aims to identify the causes of accidents and the ways to prevent accidents that occur at high-rise building construction site.Qualitative method was employed in this research. Interview surveying with safety officers who are involved in highrise building project in Kuala Lumpur were conducted in this research. Accidents were caused by man-made factors, environment factors or machinery factors.The accidents prevention methods were provide sufficient Personal Protective Equipment (PPE), have a good housekeeping, execute safety inspection, provide safety training and execute accidents investigation.In the meanwhile, interviewees have suggested the new prevention methods that were develop a proper site layout planning and de-merit and merit system among subcontractors, suppliers and even employees regarding safety at workplace matters.This research helps in explaining the causes of accidents and identifying area where prevention action should be implemented, so that workers and top management will increase awareness in preventing site accidents
Phase separation behaviour in blends of isotactic polypropylene and ethylene— propylene diene terpolymer
Miscibility and phase separation behaviour in blends of isotactic polypropylene (iPP) and ethylene-propylene diene terpolymer (EPDM, ethylene content 70%) have been examined by means of depolarized light scattering, polarizing optical microscopy, differential scanning calorimetry and dynamic mechanical methods. A cloud point phase diagram was established by means of light scattering after eliminating the influence of iPP crystal melting on liquid-liquid phase separation of iPP/EPDM blends. A lower critical solution temperature (LCST) was observed above the crystallization temperature, but below the melting temperature of iPP. This LCST is thermally reversible, so long as crystallization does not occur in its vicinity. The coupling between the crystal melting and liquid-liquid phase separation has been examined. Crystallization-induced phase separation and morphology development during crystallization of iPP have been investigated
Investigation of Ni/SiO2 catalysts prepared at different conditions for hydrogen production from ethanol steam reforming
Ni/SiO2 catalysts prepared by a sol–gel method have been investigated for hydrogen production via steam reforming of ethanol using a continuous flow, fixed bed reactor system. Chemical equilibrium calculations were also performed to determine the effects of temperature and molar steam to carbon ratio on hydrogen production. The acidity of the preparation solution (modified by nitric acid and ammonia) and calcination atmosphere (air and N2) were investigated in the preparation of the catalysts. BET surface area and porosity, temperature-programmed oxidation (TPO), X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to characterise the prepared catalysts. The BET surface area was reduced when the solution acidity was lowered during the sol–gel preparation process. A pH value less than 2.0 was necessary to achieve high metal dispersion in the catalyst. Smaller NiO particles were obtained when the catalyst was calcined in N2. Material balances on ethanol steam reforming at 600 °C using the prepared Ni/SiO2 catalysts were determined, and higher hydrogen production with lower coke deposition on the reacted catalysts were also obtained from the catalysts calcined in N2 atmosphere
Who is publishing in ecology and evolution? the underrepresentation of women and the Global South
Introduction: Most global biodiversity is in developing economies. Decades of capacity building should have built sufficient in-country capacity to develop biodiversity baselines; yet has effort provided the expertise to build these baselines?Methods: Grants and access to research opportunities are often linked to success in publishing, with the H-index providing the main metric of academic success. Recent compilations of “Top Researchers in Ecology and Evolution” included 5,419 researchers, but where these researchers are and how representative they are has not been well studied. We explored the global distribution of “Top Researchers in Ecology and Evolution” and explored the representation of Women, non-Caucasians, and non-Caucasian women, as well as the representation of “local” top researchers in different regions.Results: Over half Top Researchers in Ecology and Evolution are from just three countries (United States, United Kingdom, and Australia), and 83% come from 12 higher-income countries. Even in lower-income economies the majority of the few “high impact” researchers are originally from higher-income economies. Only China had a high proportion of their high-impact non-Caucasian researchers, with the majority of researchers coming from that region. Women were also underrepresented across the globe, only three countries had more than 20% of top-performing ecologists being female.Discussion: Ultimately, despite decades of capacity building, we are still failing to build in-country capacity for research or to provide sufficient support for female ecologists to publish and lead the field. Here we discuss why these issues persist, and how we might improve representation and access to opportunity and support for all groups, and provide the analysis needed to provide solutions to global challenges in biodiversity conservation, which require diverse representation to develop effective, and nuanced solutions
Enhancement of Mechanical and Thermal Properties of Polycaprolactone/Chitosan Blend by Calcium Carbonate Nanoparticles
This study investigates the effects of calcium carbonate (CaCO3) nanoparticles on the mechanical and thermal properties and surface morphology of polycaprolactone (PCL)/chitosan nanocomposites. The nanocomposites of PCL/chitosan/CaCO3 were prepared using a melt blending technique. Transmission electron microscopy (TEM) results indicate the average size of nanoparticles to be approximately 62 nm. Tensile measurement results show an increase in the tensile modulus with CaCO3 nanoparticle loading. Tensile strength and elongation at break show gradual improvement with the addition of up to 1 wt% of nano-sized CaCO3. Decreasing performance of these properties is observed for loading of more than 1 wt% of nano-sized CaCO3. The thermal stability was best enhanced at 1 wt% of CaCO3 nanoparticle loading. The fractured surface morphology of the PCL/chitosan blend becomes more stretched and homogeneous in PCL/chitosan/CaCO3 nanocomposite. TEM micrograph displays good dispersion of CaCO3 at lower nanoparticle loading within the matrix
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