767 research outputs found

    The electrokinetic impact on heavy metals remediation of Tasik Chini iron ore mine tailings, at Pahang state, Peninsular Malaysia

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    The improper disposal of mining tailings is a severe threat to the surrounding environment because it comprises high concentrations of heavy metals contamination. Any precious metal extraction (mining) produces millions of tons of waste; iron ore extraction is common globally, unlike other metals extraction. The iron ore tailings contain heavy metals such as Arsenic (As), Cobalt (Co), Manganese (Mn), Lead (Pb), Copper (Cu), and Zinc (Zn). This study focuses on extracting hazardous metals such as As, V, and Zn from the disposed waste and improving its geotechnical properties. Nine samples were collected from Tasik Chini Iron ore mine, Pekan district, Pahang State, Malaysia. The initial data were prepared for elemental analysis by following ICP-OES analysis. The results showed that As, Co, Mn, Pb, Cu, and Zn concentrations exceeded the standard guidelines. In recent years, sustainable remediations techniques (EKR) have attracted extensive attention, including the electrokinetic remediation technique. The (EKR) method was applied to extract these metals from iron ore tailings specimens. A comprehensive approach of EKR shows an outstanding result where the highest removal efficiency of As was 68.4 %, Co 64.5%, Mn 67.8%, Pb 67.1%, and Cu was 64.1% and Zn 64.9% with the voltage gradient of 100 and 150 V for 4 and 8 hours constantly. Increasing the voltage gradient could be a cost-effective long-term solution for the remediation of iron ore tailings. The existing method was experienced as an effective and green technique for extracting heavy metals and recycling the mining waste materials

    High Performance Antenna System in MIMO Configuration for 5G Wireless Communications Over Sub-6 GHz Spectrum

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    This paper presents a high-performance multiple input and multiple output (MIMO) antenna comprising 2 × 2 configuration of radiating elements that is designed for sub-6 GHz applications. The proposed MIMO antenna employs four identical radiating elements. High isolation between the radiating elements and therefore reduced mutual coupling is achieved by spatially arranging the radiating elements in an orthogonal configuration. Also, a novel frequency selective surface (FSS) was employed to increase the gain of the MIMO antenna over a wide bandwidth from 3 to 6 GHz. This was achieved by locating the FSS above the antenna at a certain height. The FSS essentially enhanced the antenna's directivity, reduced back lobe radiation and mutual coupling. The antenna was fabricated on a standard Rogers RT Duroid 5880 dielectric substrate with a 0.8 mm thickness. The overall dimension of the MIMO antenna is 50 × 50 × 12.5 mm3 and it operates from 3.8 to 6 GHz, which corresponds to a fractional bandwidth of 41%. The proposed MIMO antenna has a measured peak gain of 4.8 dBi and inter radiation element isolation >20 dB. Its envelope correlation coefficient is <0.1 and diversity gain >9.9 (dB). These characteristics make the proposed MIMO antenna system suitable for 5G communication systems

    Spotted fever group rickettsiae in ticks collected from wild animals in Israel

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    We report molecular evidence for the presence of spotted fever group rickettsiae (SFGR) in ticks collected from roe deer, addax, red foxes, and wild boars in Israel. Rickettsia aeschlimannii was detected in Hyalomma marginatum and Hyalomma detritum while Rickettsia massiliae was present in Rhipicephalus turanicus ticks. Furthermore, a novel uncultured SFGR was detected in Haemaphysalis adleri and Haemaphysalis parva ticks from golden jackals. The pathogenicity of the novel SFGR for humans is unknown; however, the presence of multiple SFGR agents should be considered when serological surveillance data from Israel are interpreted because of significant antigenic cross-reactivity among Rickettsia. The epidemiology and ecology of SFGR in Israel appear to be more complicated than was previously believed. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene

    Brown fat triglyceride content is associated with cardiovascular risk markers in adults from a tropical region

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    Brown adipose tissue (BAT) is regarded as an interesting potential target for the treatment of obesity, diabetes, and cardiovascular diseases, and the detailed characterization of its structural and functional phenotype could enable an advance in these fields. Most studies evaluating BAT structure and function were performed in temperate climate regions, and we are yet to know how these findings apply to the 40% of the world’s population living in tropical areas. Here, we used 18F-fluorodeoxyglucose positron emission tomography – magnetic resonance imaging to evaluate BAT in 45 lean, overweight, and obese volunteers living in a tropical area in Southeast Brazil. We aimed at investigating the associations between BAT activity, volume, metabolic activity, and BAT content of triglycerides with adiposity and cardiovascular risk markers in a sample of adults living in a tropical area and we showed that BAT glucose uptake is not correlated with leanness; instead, BAT triglyceride content is correlated with visceral adiposity and markers of cardiovascular risk. This study expands knowledge regarding the structure and function of BAT in people living in tropical areas. In addition, we provide evidence that BAT triglyceride content could be an interesting marker of cardiovascular risk

    Unmodified Titanium Dioxide Nanoparticles as a potential contrast agent in photon emission computed tomography

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    Highly crystalline titanium dioxide nanoparticles (TiO2 -NPs) are synthesized via a simple hydrothermal technique. After structural and compositional analysis, the as-synthesized unmodified TiO2 -NPs are tested for improvement in two modes of kilovoltage radiation therapy and singlephoton emission computed tomography (SPECT)/computed tomography (CT). Our results show that the unmodified TiO2 -NPs provide an observable enhancement in CT scan image contrast ranging from 0 ± 3 HU (without NPs) to 283.7 ± 3 HU (0.23 g/mL). TiO2 -NPs has excellent biocompatibility, selective uptake at target sites, and reduced toxicity. The unmodified TiO2 -NPs as a contrast agent can significantly improve the existing methods of diagnosing and treating cancer

    Use of alcoholic beverages in VA medical centers

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    BACKGROUND: Benzodiazepines are the first-line choice for the treatment of alcohol withdrawal syndrome. However, several hospitals continue to provide alcoholic beverages through their formulary for the treatment of alcohol withdrawal. While there are data on the prevalence of this practice in academic medical centers, there are no data on the availability of alcoholic beverages at the formularies of the hospitals operated by the department of Veteran's Affairs. METHODS: In this study, we surveyed the Pharmacy managers at 112 Veterans' Affairs Medical Centers (VAMCs) to ascertain the availability of alcohol on the VAMC formularies, and presence or lack of a policy on the use of alcoholic beverages in their VA Medical Center. RESULTS: Of the pharmacy directors contacted, 81 responded. 8 did not allow their use, while 20 allowed their use. There was a lack of a consistent policy across the VA medical centers on availability and use of alcoholic beverages for the treatment of alcohol withdrawal syndrome. CONCLUSION: There is lack of uniform policy on the availability of alcoholic beverages across the VAMCs, which may create potential problems with difference in the standards of care

    Bone Marrow Metabolism Is Impaired in Insulin Resistance and Improves After Exercise Training

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    Context: Exercise training improves bone mineral density, but little is known about the effects of training on bone marrow (BM) metabolism. BM insulin sensitivity has been suggested to play an important role in bone health and whole-body insulin sensitivity.Objective: To study the effects of exercise training on BM metabolism.Design: Randomized controlled trial.Setting: Clinical research center.Participants: Sedentary healthy (n = 28, 40-55 years, all males) and insulin resistant (IR) subjects (n = 26, 43-55 years, males/females 16/10).Intervention: Two weeks of sprint interval training or moderate-intensity continuous training.Main outcome measures: We measured femoral, lumbar, and thoracic BM insulin-stimulated glucose uptake (GU) and fasting free fatty acid uptake (FFAU) using positron-emission tomography and bone turnover markers from plasma.Results: At baseline, GU was highest in lumbar, followed by thoracic, and lowest in femoral BM (all Ps Conclusions: BM metabolism differs regarding anatomical location. Short-term training improves BM GU and FFAU in healthy and IR subjects. Bone turnover rate is decreased in insulin resistance and associates positively with BM metabolism and glycemic control.</p

    Structural, optical, and antibacterial efficacy of pure and zinc-doped copper oxide against Pathogenic bacteria

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    Copper oxide and Zinc (Zn)-doped Copper oxide nanostructures (CuO-NSs) are successfully synthesized by using a hydrothermal technique. The as-obtained pure and Zn-doped CuONSs were tested to study the effect of doping in CuO on structural, optical, and antibacterial properties. The band gap of the nanostructures is calculated by using the Tauc plot. Our results have shown that the band gap of CuO reduces with the addition of Zinc. Optimization of processing conditions and concentration of precursors leads to the formation of pine needles and sea urchinlike nanostructures. The antibacterial properties of obtained Zn-doped CuO-NSs are observed against Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria via the agar well diffusion method. Zn doped s are found to have more effective bacterial resistance than pure CuO. The improved antibacterial activity is attributed to the reactive oxygen species (ROS) generation
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