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The present study is the first assessment of inorganic arsenic exposure from various fishery products to the Indonesian population based on a national total diet study (TDS). Based on the TDS report on food chemical contaminants, fish and processed fishery products are among the foodstuffs significantly contributing to total arsenic (t-As) exposure in Indonesia. However, there is no assessment yet for the Indonesian population to inorganic arsenic (i-As), which is known as the most harmful of arsenic compounds as it potentially promotes acute and chronic poisoning. The present assessment is aimed to estimate the exposure to i-As from fish and processed fishery products as well as the level of health risks in different age groups in Indonesia, based on the available t-As concentration data. The results showed that the mean exposure to t-As and i-As from fish and processed fishery products in various age groups were 1.19–2.67 μg/kg bw/day and 0.04–0.08 μg/kg bw/day, respectively. Exposure in various age groups revealed that the highest arsenic exposure was in toddlers (0–4 years) and the lowest in the age group of 19–55 years. Wet seasonings and marine fish consumption led to the most contributors to i-As exposure. The carcinogenic risk of i-As exposure based on the margin of exposure (MOE) demonstrated a low to moderate risk. However, a particular concern to the toddler group is required as the cancer risk (CR) value is higher than the acceptable threshold (>10−4). Additionally, the hazard quotient (HQ) of i-As exposure was determined as a low possibility of chronic risk.

The incidence of type 2 diabetes mellitus is increasing in developing countries, including Indonesia. Insulin resistance is a significant contributor to elevated blood glucose levels in type-2 diabetes patients. Low levels of serum sirtuin-1, irisin, and vitamin D have been linked to insulin resistance. This study aimed to identify risk factors that could predict uncontrolled glycemia and insulin resistance in Indonesian type-2 diabetes patients. We conducted a cross-sectional study with 73 adults from South Jakarta, Indonesia, in which we examined type-2 diabetes risk factors and biomarkers, including sex, age, body mass index, waist circumference, waist–to–hip ratio, fasting blood glucose (FBG) levels, fasting insulin, sirtuin-1, irisin, and vitamin D levels. The subjects were categorized into two groups based on their glycated hemoglobin (HbA1c) level and homeostatic model assessment for insulin resistance (HOMA-IR) index to assess glycemic control and insulin resistance, respectively. We compared risk factor profiles between groups and analyzed multivariate relationships with logistic regression. Our findings revealed that 54 % of the subjects had uncontrolled glycemia, whereas only 11 % had insulin resistance. There was a significant association between uncontrolled glycemia and reduced sirtuin-1 levels (odds ratio = 4.07; p = 0.03), which was confirmed in the multivariate analysis (beta = 5.41, p = 0.014) along with FBG (beta = 36.88, p = 0.001). Irisin showed a marginal association with insulin resistance in both univariate (odds ratio = 0.12; p = 0.027) and multivariate analyses (beta = 0.09; p = 0.049). In conclusion, sirtuin-1, in addition to FBG, is a potential marker for assessing glycemic control in type-2 diabetes patients.

Abstract: This study investigated the effects of temperature, pH, and stirring speed of multistage precipitation processes. The purification process consists of uranium and thorium precipitation, oxalate precipitation, calcination, HNO3leaching, and oxidation; finally, multistage precipitation is performed using Na2CO3and NH4OH. The precipitation efficiencies of light rare earth elements (LREEs) and heavy rare earth elements (HREEs) reached 88% and 74%, respectively, during precipitation with 15% Na2CO3at a temperature of 50 °C, pH of 4.5, and 200 rpm. The precipitation process was continued by adding 10% NH4OH to the first precipitation raffinate. A total of 45% of the LREEs were recovered at a temperature of 30 °C, pH of 8, and 300 rpm. Meanwhile, 72% of the HREEs were recovered at a temperature of 30 °C, pH of 7, and 200 rpm. It was observed that Na2CO3was effective in precipitating rare earth elements (REEs) at higher temperatures, whereas NH4OH was better at precipitating the HREEs from an REE-nitrate solution under the same processing conditions. Graphical Abstract:

Similarity of chemical and physical properties between rare-earth elements (REEs) and Dy is the main concern in order to get Dy with high purity, which it is necessary to do separation by extraction process. The purpose of this research is to obtain the optimum condition of operation (stirring time and rate, concentration of nitric acid, feed, and solvent) and determine the distribution constant, separation factor, and extraction efficiency of Dy using Aliquat 336. This research was conducted by varying stirring time (10, 15, 20, 30, 40 minutes), stirring rate (100, 150, 200, 250, 300 rpm), nitric acid concentration (2, 3, 4, 5, 6 N), feed concentration (25,000; 50,000; 100,000; 150,000; 200,000 ppm) and solvent concentration (10, 20, 30, 40, 50 % v/v). The optimum result is achieved when operation is carried out at stirring 100 rpm about 15 minutes in nitric acid 3 N with 100,000 ppm of feed concentration using 30% solvent concentration (v/v) which extract more Dy element than Yttrium (Y) and Godolinium (Gd). The highest distribution constant of Dy is 0.427, separation factor of Dy-Y is 6.831, separation factor of Dy-Gd is 1.799, and extraction efficiency of Dy is 31.604%.

The nanocrystalline HA powders were produced through sol-gel method which employed calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] and diammonium hydrogen phosphate [(NH4)2HPO4] as calcium and phosphorous precursors. Sodium ion (Na+) is one of the trace elements found in biological apatite and believed to have important effect in its performance. The concentrations of sodium dopant were varied from 0 mol% until 15 mol% by using sodium nitrate (NaNO3) as the source of dopant. Characterization of nanopowders was investigated by using X-ray diffraction (XRD), Fourier transform infra red (FTIR) and Transmission Electron Microscope (TEM). XRD analysis revealed that there are no other phases exist in the synthesized powder, evinced single phase of HA and a trend shows an increase of cristallinity with increase of sodium dopant concentration. While the TEM images showed evidence that the particle sizes were bigger with the increasing sodium concentration, showing the effect of sodium dopant on the densification of the powder.

The El Nino Southern Oscillation (ENSO) is a global phenomenon that affects the variability of rainfall in North Sumatra. The influence of ENSO will be different for each region. This review will analyse the influence of ENSO activity on seasonal and annual rainfall variability. In this research, North Sumatra Province will be divided into 4 (four) regions based on topographical conditions, such as: East Coast (EC), East Slope (ES), Mountains (MT), and West Coast (WC). The method used was statistical and descriptive analysis. Data used in this research were rainfall data from 15 stations / climate observation posts which spread in North Sumatera region and also anomaly data of Nino 3.4 region from period 1981-2016. The results showed that the active El Nino had an effect on the decreasing the rainfall during the period of DJF, JJA and SON in East Coast, East Slope, and Mountains with the decreasing of average percentage of annual rainfall up to 7%. On the contrary, the active La Nina had an effect on the addition of rainfall during the period DJF and JJA in the East Coast and Mountains with the increasing of average percentage of annual rainfall up to 6%.

This paper reports our study on the synthesis of high electrical conductivity and surface area polyaniline using oxidative polymerization under UV light irradiation. The formation of emeraldine structures of polyaniline was revealed by major absorption bands of FTIR (Fourier transform infrared spectroscopy) spectra attributed to C-N stretching, C=C stretching in the benzenoid ring, C=C stretching in the quinoid ring and QNH+B stretching. XRD (X-ray diffractometer) measurements confirmed typical diffraction patterns with a crystallinity of 13% and 16% for polyaniline prepared under non-stirred and stirred reaction, respectively. SEM (Scanning electron microscope) studies showed more uniform morphology of polyaniline was obtained with stirring reaction process compare to those prepared without stirring. Surface analysis using SAA (surface area analyzer) showed that pure polyaniline with the relatively high surface area of ca.28 m2/g was successfully prepared in this work. Based on four point probe measurement, the prepared polyaniline possesses high conductivity which is important in electrode application.