Biogenic synthesis of gold nanoparticles using Satureja rechingeri Jamzad: a potential anticancer agent against cisplatin-resistant A2780CP ovarian cancer cells

Environmental Science and Pollution Research - Drug resistance of cancer cells is a major issue in cancer treatment. Plant-mediated nanoparticle synthesis has been applied in recent years to...     

Association of serum lead and mercury level with cardiometabolic risk factors and liver enzymes in a nationally representative sample of adolescents: the CASPIAN-III study

This study aims to determine the difference of serum Pb and Hg levels in adolescents with or without metabolic syndrome (MetS) and the association of serum levels of these heavy metals with cardiometabolic risk factors and liver enzymes in Iranian adolescents. The study population consisted of 320 adolescents (160 with MetS and 160 healthy controls). The relationship between serum heavy metals and cardiometabolic risk factors was assessed by linear regression. The odds ratios (OR) of having metabolic syndrome across Pb and Hg quartiles were determined by multiple logistic regression analysis. The mean (SD) of Pb and Hg concentrations were higher in adolescents with MetS than in those without it (0.83 (0.27) and 0.17 (0.01) vs. 0.65 (0.15) and 0.10 (0.08)?μg/L, P?=?0.01 and 0.0001, respectively). Increase in serum Pb and Hg was associated with increase in some cardiometabolic risk factors. Among boys and girls, diastolic blood pressure (DBP), fasting blood glucose, total cholesterol (TC), triglycerides (TG), and alanine aminotransaminase increased significantly across quartiles of serum Pb. Among girls, SBP, DBP, TC, and TG had a significant increase across Hg quartiles. The corresponding figure among boys was significant for SBP, DBP, and TG. Higher quartiles of Pb increased the risk of having MetS (OR 95 % CI 3.10, 2.25–4.27), the corresponding figure was 2.03, 1.75–3.16, across Hg quartiles. Our study showed significant associations between serum Pb and Hg levels with cardiometabolic risk factors in adolescents. In future surveys, the role of potential confounders should be considered more extensively. The clinical significance of these findings needs to be confirmed in longitudinal studies. By considering the origins of chronic diseases from early life, controlling environmental pollutants should be considered as a health priority for primordial or primary prevention of noncommunicable diseases.     

Comparison of Polylactic Acid/Kenaf and Polylactic Acid/Rise Husk Composites: The Influence of the Natural Fibers on the Mechanical, Thermal and Biodegradability Properties

This paper investigates and compares the performances of polylactic acid (PLA)/kenaf (PLA-K) and PLA/rice husk (PLA-RH) composites in terms of biodegradability, mechanical and thermal properties. Composites with natural fiber weight content of 20% with fiber sizes of less than 100 μm were produced for testing and characterization. A twin-screw extrusion was used to compound PLA and natural fibers, and extruded composites were injection molded to test samples. Flexural and Izod impact test, TGA, soil burial test and SEM were used to investigate properties. All results were compared to a pure PLA matrix sample. The flexural modulus of the PLA increased with the addition of natural fibers, while the flexural strength decreased. The highest impact strength (34 J m⁻¹), flexural modulus (4.5 GPa) and flexural strength (90 MPa) were obtained for the composite made of PLA/kenaf (PLA-K), which means kenaf natural fibers are potential to be used as an alternative filler to enhance mechanical properties. On the other hand PLA-RH composite exhibits lower mechanical properties. The impact strength of PLA has decreased when filled with natural fibers; this decrease is more pronounced in the PLA-RH composite. In terms of thermal stability it has been found that the addition of natural fibers decreased the thermal stability of virgin PLA and the decrement was more prominent in the PLA-RH composite. Biodegradability of the composites slightly increased and reached 1.2 and 0.8% for PLA-K and PLA-RH respectively for a period of 90 days. SEM micrographs showed poor interfacial between the polymer matrix and natural fibers.     

An Objective Multiattribute Analysis Approach for Allocation of Scarce Irrigation Water Resources1

Zardari, Noor ul Hassan, Ian Cordery, and Ashish Sharma, 2010. An Objective Multiattribute Analysis Approach for Allocation of Scarce Irrigation Water Resources. Journal of the American Water Resources Association (JAWRA) 46(2):412-428. DOI: 10.1111/j.1752-1688.2009.00410.x Abstract: In this study, end user (farmer) and decision maker (water allocator) opinions were surveyed and a conjoint analysis (CA) based method was applied to the quantitative and qualitative data to assess the utility associated with each attribute that plays a role in forming the final thinking of the water users. The application of CA for estimating the utility for each attribute level is a novel approach, which helps provide a formal, objective basis for assigning relative scales for each attribute interval within a multiattribute decision-making model. The utilities (part-worths) obtained from the CA have a cardinal scale and were found to be comparable within and across the attributes. A farmers’ survey on five water allocation attributes was completed from 62 farmers and their opinions on the relative importance of attributes were elicited for a subarea of the Indus River Basin. The CA method was then applied to the survey data and the utilities for each attribute level were determined. This allowed, for instance, decisions to be made, which take account of the perceived value of the water and of the availability of local labor to work on the farm. Finally, these interval scales were used within the specification of the ELECTRE multiattribute decision-making method to provide a complete and objective ranking of nine irrigation districts so that the best decisions on water allocation could be made.     

Extraction of ultra traces of polychlorinated biphenyls in aqueous samples using suspended liquid-phase microextraction and gas chromatography-electron capture detection

This study reports the feasibility of applying directly suspended liquid-phase microextraction (DSLPME)-gas chromatography detection for the pre-concentration and determination of low levels of eight polychlorinated biphenyls (PCBs) in aqueous samples. The technique requires minimal sample preparation, analysis time and solvent consumption and represents significant advantages over conventional analytical methods. The experimental parameters such as salt content, sample temperature, stirring rate, extraction time, micro-drop volume and breakthrough volume were investigated and found to have significant influences on DSLPME. Under the optimal experimental conditions, the enrichment factor ranged from 578 to 729, and the recovery was above 93 %. Calibration curves possessed good linearity (R ²?>?0.99) over a wide concentration range of 0.1–10.0 μg L^?1 with limits of detection ranging from 0.01 to 0.07 μg L^?1. The relative standard deviations for 1.0 μg L^?1 of PCBs in water by using internal standard were in the range 2–14 % (n?=?3). The proposed simple, accurate and sensitive analytical method was applied successfully to the determination of trace amounts of PCBs in water samples.     

Preparation and Properties of Starch/Nanosilicate Layer/Polycaprolactone Composites

Starch nanocomposites have been prepared using mineral clay. Montmorillonite, kaolin and a surface-modified montmorillonite by dimethyl (hydrogenated tallow alkyl) ammonium cation were used. Starch-g-PCL nanocomposites have been prepared with graft polymerization through in situ ring-opening polymerization of ε-caprolactone in the presence of starch, Sn(Oct)₂ (Tin(II) 2-ethyl hexanoate) as an initiator/catalyst and silicate layers. In fact, the related composites were prepared in solution method, bulk polymerization and in situ polymerization methods with introducing the mineral clay. The effect of kind of clay on d-spacing of silicate layers was investigated and the obtained nanocomposites were analyzed using X-ray diffraction. The obtained compounds were characterized by Fourier transform infrared (FT-IR). Morphology of the prepared nanocomposites was investigated using scanning electron microscopy and DSC enhanced the study of thermal behaviour of the prepared composite compounds.     

Investigation the effect of adding graphene oxide into diesel/higher alcohols blends on a diesel engine performance

ABSTRACT

This article aims to study the influence of the addition of graphene oxide nanoparticles (GO) to diesel/higher alcohols blends on the combustion, emission, and exergy parameters of a CI engine under various engine loads. The higher alcohols mainly n-butanol, n-heptanol, and n-octanol are blended with diesel at a volume fraction of 50%. Then, the 25 and 50 mg/L concentrations of GO are dispersed into diesel/higher alcohols blends using an ultrasonicator. The GO structures are examined using TEM, TGA, XRD and FTIR. The findings show that there is a reduction in p_max. and HRR when adding higher alcohols with diesel fuel. Regarding engine emission, there is a significant improvement in emissions formation with adding higher alcohols. The addition of GO into diesel/higher alcohols blends improves the brake thermal efficiency by 15%. Moreover, the p_max. and HRR are both enhanced by 4%. The CO, UHC and smoke formation are reduced considerably by 40%, 50 and 20%, respectively, while NO_x level is increased by 30% with adding GO. Finally, adding high percentages of n-butanol, n-heptanol, and n-octanol with diesel fuel with the presence of GO has the potential to achieve ultra-low CO, UHC, and smoke formation meanwhile keeping high thermal efficiency level.     

Review of ozone and temperature lidar validations performed within the framework of the Network for the Detection of Stratospheric Change

The use of assimilation tools for satellite validation requires true estimates of the accuracy of the reference data. Since its inception, the Network for Detection of Stratospheric Change (NDSC) has provided systematic lidar measurements of ozone and temperature at several places around the world that are well adapted for satellite validations. Regular exercises have been organised to ensure the data quality at each individual site. These exercises can be separated into three categories: large scale intercomparisons using multiple instruments, including a mobile lidar; using satellite observations as a geographic transfer standards to compare measurements at different sites; and comparative investigations of the analysis software. NDSC is a research network, so each system has its own history, design, and analysis, and has participated differently in validation campaigns. There are still some technological differences that may explain different accuracies. However, the comparison campaigns performed over the last decade have always proved to be very helpful in improving the measurements. To date, more efforts have been devoted to characterising ozone measurements than to temperature observations. The synthesis of the published works shows that the network can potentially be considered as homogeneous within +/-2% between 20-35 km for ozone and +/-1 K between 35-60 km for temperature. Outside this altitude range, larger biases are reported and more efforts are required. In the lower stratosphere, Raman channels seem to improve comparisons but such capabilities were not systematically compared. At the top of the profiles, more investigations on analysis methodologies are still probably needed. SAGE II and GOMOS appear to be excellent tools for future ozone lidar validations but need to be better coordinated and take more advantage of assimilation tools. Also, temperature validations face major difficulties caused by atmospheric tides and therefore require intercomparisons with the mobile systems, at all sites.     

Assessment of municipal solid waste generation and recyclable materials potential in Kuala Lumpur,Malaysia

This paper presents a forecasting study of municipal solid waste generation (MSWG) rate and potential of its recyclable components in Kuala Lumpur (KL), the capital city of Malaysia. The generation rates and composition of solid wastes of various classes such as street cleansing, landscape and garden, industrial and constructional, institutional, residential and commercial are analyzed. The past and present trends are studied and extrapolated for the coming years using Microsoft office 2003 Excel spreadsheet assuming a linear behavior. The study shows that increased solid waste generation of KL is alarming. For instance, the amount of daily residential SWG is found to be about 1.62 kg/capita; with the national average at 0.8–0.9 kg/capita and is expected to be increasing linearly, reaching to 2.23 kg/capita by 2024. This figure seems reasonable for an urban developing area like KL city. It is also found that, food (organic) waste is the major recyclable component followed by mix paper and mix plastics. Along with estimated population growth and their business activities, it has been observed that the city is still lacking in terms of efficient waste treatment technology, sufficient fund, public awareness, maintaining the established norms of industrial waste treatment etc. Hence it is recommended that the concerned authority (DBKL) shall view this issue seriously.