Comparative study of the electro spun pan nanofiber reinforced with CNT and CNF: effect on morphology, thermal stability and electroconductivity properties

Reinforced electrospun PAN nanofibers with carbon nanotubes and carbon nanofibers were produced via electrospinning technique. The spinning was carried out in a ratio of 6 and 10 wt. % of CNT and CNF to PAN slurry, respectively. The applied voltage was 10.0 kV and the spuns had undergone three stages of thermal treatments namely, stabilization, carbonization, and graphitization. This study indicated that the nanofiber diameter, thermal stability and electric conductivity properties of the PAN electrospun were greatly affected by the ratio of the nanoparticles. The morphological study revealed that the fiber diameters of the PAN/CNT electrospun were between 0.62 and 0.70 µm, and the PAN/CNF fiber diameters were between 1.03 and 1.20 µm, respectively. For the thermal stability study, it was observed that the thermal degradation of the PAN polymer increased as the CNT and CNF ratios were increased. The electroconductivity study also revealed that addition of CNT had increased the conductivity of the PAN polymer until 5.4 × 10-4 Scm-1. CNF increased the electrical resistivity of PAN from 2.49 × 10-5 to 1690.2 Ω cm-1

Correlation of heavy metal content in water to the development of CKD in Ranau, Sabah

The negative health impact caused by chronic heavy metal poisoning in Malaysia has raised an awareness to institute to form early screening programs in high-risk populations. Recently, Ranau had been alarmed by a sudden spike in patients with kidney failure, reporting of 7 cases from Kg. Libang, 4 cases from Kg. Kinapulidan and Kg. Matan respectively, and many more villages affected. With the CKD cases concentrating in the district, 2 possible causes are: water sources contaminated with heavy metals via acid mine drainage from the ex Mamut copper mine and the bioaccumulation of heavy metals in the crops from agricultural chemicals and/or pre-existing heavy metals in the soil. Therefore, this entails the need to detect the damages in its early stages. Preventive measures can come in the form of environmental monitoring i.e., testing the water and soil for heavy metals that are known to be toxic and carcinogenic. This study aims to develop a method to determine heavy metals that are below the detection limit of the conventional instruments outside of a clean room setting, such as ICP-MS analysis, noting that concentration that fall below sub-ppt level cannot be detected by all types of instruments available in the market. The soil quality was previously reported as significantly contaminated. However, none have linked the contaminated soil to the water sources and the consequences on human health because of the undetectably low levels of heavy metals present in the water. Mine site rehabilitation procedures and educating the farmers are solutions to prevent further heavy metal damages towards the surrounding environment. Nonetheless, this post as a costly and challenging procedure to be carried out. Meanwhile, the district provides an excellent opportunity for future research to better understand the relationship between heavy metals and human health in the context of medical geology

Crystallisation of solvothermally synthesized ZIF-8 investigated at the bulk, single crystal and surface level

A gravimetric study of the solvothermal dimethylformamide-mediated crystallisation of the metal–organic framework ZIF-8 has enabled the rate constants and activation energies of the nucleation and crystal growth processes to be determined. The kinetics analyses reveal the crystallisation is nucleation controlled with activation energies for nucleation and crystal growth of 115.1 and 87.7 kJ mol−1, respectively. The results are compared to the crystallisation kinetics for other syntheses of ZIF-8 and other MOFs to reveal the importance that different solvents, different metal ion/organic linker ratios and the presence of deprotonating modulators have on these processes. Temporal ex situ monitoring of the crystal morphology and surface topography during crystallisation reveals the crystals evolve to the equilibrium rhombic dodecahedral morphology via edge-truncated cubic and corner-truncated rhombic dodecahedral habits while relatively smooth surfaces containing large truncated rhombic surface terraces and growth spirals develop through rough surfaces consisting of numerous ill-defined small growth islands and steps. The combination of techniques applied over different size scales provides important understanding for potential control over the crystal properties of MOFs for new application or enhanced performance in current applications

Spatial and temporal variation of zooplankton in Sepanggar bay, Sabah

Zooplankton spatio-temporal distribution and the community dynamics corresponding to environmental changes were studied in Sepanggar Bay, Sabah. Samples were taken in horizontal tows using a 140 µm net at nine stations during four study periods; June, October 2017 and March, June 2018, coinciding with the SW, NE and intermonsoon seasons. Zooplankton were enumerated and identified to the lowest taxonomic level possible. All in-situ parameters measured in this study were significantly different among monsoons (p < 0.05), but not spatially. In total, 110 zooplankton taxa were observed and copepods were dominant (70% of total composition) and were most abundant during intermonsoon (40610 ± 48437 inds. /m3). Similarly, maximal zooplankton abundance was during Intermonsoon with the mean of 47628 ± 55488 inds. /m3. Zooplankton abundance showed significant monsoonal variation among seasons (p=0.01). Chlorophyll-a concentration peak period coincided with zooplankton abundance peaks, which was during Intermonsoon. Temperature showed positive correlation with total zooplankton and copepod abundances. In summary, the zooplankton abundance and composition is more sensitive to the changes in monsoon than that in space

Association between Lower Extremity Skeletal Muscle Mass and Impaired Cognitive Function in Type 2 Diabetes

10.1038/s41598-020-59914-3Scientific Reports101295

A Multicenter Study: North American Islet Donor Score in Donor Pancreas Selection for Human Islet Isolation for Transplantation

Selection of an optimal donor pancreas is the first key task for successful islet isolation. We conducted a retrospective multicenter study in 11 centers in North America to develop an islet donor scoring system using donor variables. The data set consisting of 1,056 deceased donors was used for development of scoring system to predict islet isolation success (defined as post-purification islet yield >400,000 islet equivalents). With an aid of univariate logistic regression analyses, we developed North American Islet Donor Score (NAIDS) ranging 0 through 100 points. The c-index in the development cohort was 0.73 [95% confidence interval 0.70 - 0.76]. The success rate increased proportionally as NAIDS increased, from 6.8% success in NAIDS < 50 points to 53.7% success in NAIDS ≥ 80 points. We further validated NAIDS using a separate set of data consisting of 179 islet isolations. Comparable outcome of NAIDS was observed in the validation cohort. The NAIDS may be a useful tool for donor pancreas selection in the clinical practice. Apart from its utility in clinical decision-making, the NAIDS may also be used in research setting as a standardized measurement of pancreas quality