Effects of Temperature and Pore Structure on High Surface Area-Activated Carbon Obtained from Peanut Shells

Activated carbon was synthesized from peanut shells by treating with H3PO4 with an intention to enhance the surface area and to find its electrochemical performance in EDLC as electrode material. The powdered peanut shells were pyrolyzed at three different temperatures namely 300 degrees C, 600 degrees C and 800 degrees C respectively. The structural and surface properties of the pyrolyzed carbon materials were studied using N2 adsorption/desorption, Raman, TEM and SEM analysis. There has been remarkable increase in the surface area of the carbon pyrolyzed at 600 degrees C due to the effect of pore generations. The surface area of the 600 degrees C pyrolyzed sample was found to be 1629 m2/g. The electrochemical properties of all the samples were evaluated by cyclic voltammetry, impedance spectroscopy, and galvanostatic charge-discharge tests. The system showed excellent cycleability and a maximum specific capacitance of 291 Fg(-1) was obtained in a 0.1 M H2SO4 electrolyte solution. The effects of the various properties of the activated carbon on the EDLC performance are discussed.

Changes in lung function according to disease extent before and after pulmonary tuberculosis

OBJECTIVE

To evaluate changes in lung function in individuals before and after treatment for pulmonary tuberculosis (PTB) in relation to extent of disease.

DESIGN

Using a retrospective cohort design, changes in and predictors of lung function were evaluated.

RESULTS

A total of 41 patients were included in the final analysis. The median decline in annualised forced expiratory volume in 1 sec (FEV1) was 180.0 ml/year (95%CI 118.9-356.1) in advanced PTB and 94.7 ml/year (95%CI 33.4-147.3) in localised PTB (ΔFEV1% predicted/year 9.4%, 95%CI 4.4-14.0 vs. 3.8%, 95%CI 1.8-6.2). The median decline in annualised forced vital capacity (FVC) was 309.6 ml/year (95%CI 137.0-359.0) in advanced PTB and 101.1 ml/year (95%CI 30.3-219.6) in localised PTB (ΔFVC % predicted/year 7.3%, 95%CI 5.3-12.3 vs. 2.9%, 95%CI 0.9-6.5).

CONCLUSIONS

As the sample size of our study was small, the conclusions could be biased. Nevertheless, our findings show that PTB causes a significant decline in lung function even in localised PTB, whereas advanced PTB was associated with excessive or even higher decline. This study suggests that early diagnosis and treatment of PTB is needed to preserve lung function.

Pt decorated Artocarpus heterophyllus seed derived carbon as an anode catalyst for DMFC application

A carbohydrate rich biomass is hydrothermally carbonized and thermally degraded to sequester high surfaced carbon. Subsequently, the prepared carbon is decorated with Pt NPs and is executed as an anode catalyst for methanol oxidation reaction (MOR).

An overview of AB2O4- and A2BO4-structured negative electrodes for advanced Li-ion batteries

Energy-storage devices are state-of-the-art devices with many potential technical and domestic applications.

New method: Are tumor markers in vaginal-washing fluid significant in the diagnosis of primary ovarian carcinoma?

OBJECTIVE

Ovarian cancer is the seventh most common cancer in women worldwide, with nearly a quarter of a million women diagnosed every year. The serum tumor markers cancer antigens CA 125, CA 19-9, and carcinoembryonic antigen (CEA) are potentially of clinical value for the diagnosis of ovarian cancer. A diagnostic tool that is noninvasive, simple to perform, and specific is needed to predict primary ovarian cancer. The purpose of this study was to evaluate the diagnostic sensivitity and specificity of vaginal-washing tumor markers CA 125, CA 19-9, and CEA for diagnosis of primary ovarian cancer.

MATERIALS AND METHODS

In the current prospective study, 30 patients with advanced primary ovarian cancer and 30 patients with benign ovarian cysts were enrolled. The vaginal-washing fluid samples were obtained the day before surgery and were immediately centrifuged and stored at -80 degrees C until analysis. Measurements of CA 125, CA 19-9, and CEA were determined using fully-automated chemiluminescent microparticle immunoassays.

RESULTS

The vaginal fluid concentrations of CA 125, CA 19-9, and CEA in patients with primary ovarian carcinoma were significantly higher (p < 0.001) compared to those in patients with benign adnexal masses (p < 0.001). In the ROC curve analysis, the optimal cut-off values for the detection of primary ovarian cancer were >295 for CA 125 (p < 0.001), > 101 for CA 19-9 (p < 0.001), and >135 for CEA (p < 0.001).

CONCLUSION

Vaginal-washing tumor markers CA 125, CA 19-9, and CEA are simple, noninvasive, and reliable diagnostic tests for the detection of primary ovarian cancer.

Smaller size of high metabolic rate organs explains lower resting energy expenditure in Asian-Indian Than Chinese men

BACKGROUND

In Singapore, the obesity prevalence is disproportionately higher in the Asian-Indians and Malays than the Chinese. Lower resting energy expenditure (REE) may be a contributory factor.

OBJECTIVE

We explored the association between ethnicity and REE in Chinese, Asian-Indian and Malay men living in Singapore and determined the influence of body composition, mass/volume of high metabolic rate organs, represented by brain volume and trunk fat-free mass (FFM), and physical activity on ethnic differences.

DESIGN

Two hundred and forty-four men from Singapore (n=100 Chinese, 70 Asian-Indians and 74 Malays), aged 21-40 years and body mass index of 18.5-30.0 kg m(-2), were recruited in this cross-sectional study. REE was assessed by indirect calorimetry and body composition by dual-energy X-ray absorptiometry. Brain volume was measured by magnetic resonance imaging. Physical activity was assessed by the Singapore Prospective Study Program Physical Activity Questionnaire.

RESULTS

REE was significantly lower in Asian-Indians compared with that in Chinese after adjusting for body weight. FFM (total, trunk and limb) and total fat mass were important predictors of REE across all ethnic groups. Brain volume was positively associated with REE only in Malays. Moderate and vigorous physical activity was positively associated with REE only in Asian-Indians and Malays. The difference in REE between Asian-Indians and Chinese was attenuated but remained statistically significant after adjustment for total FFM (59±20 kcal per day), fat mass (67±20 kcal per day) and brain volume (54±22 kcal per day). The association between REE and ethnicity was no longer statistically significant after total FFM was replaced by trunk FFM (which includes heart, liver, kidney and spleen) but not when it was replaced by limb FFM (skeletal muscle).

CONCLUSIONS

We have demonstrated a lower REE in Asian-Indians compared with Chinese who may contribute to the higher rates of obesity in the former. This difference could be accounted for by differences in metabolically active organs.

Application of sequential expanded granular sludge bed reactors for biodegradation of acetate, benzoate, terephtalate and p-toluate in purified terephtalic acid production wastewater

The anaerobic degradation of four major constituents from purified terephtalic acid production wastewater in sequential two expanded granular sludge bed (EGSB) reactors was studied. The performance of the system was evaluated in terms of chemical oxygen demand (COD) removal efficiencies, methane production, stability, granular sludge adaptability as well as reversion of bacterial inhibition. With volumetric loading rates of 1.9-25 kg-COD m(-3) d(-1) and terephtalate and p-toluate of 584-821 mg L(-1), average removal efficiencies of 97.6% and 75.2% were achieved in the EGSB reactors, respectively. In these conditions, gas production reached a total methane production rate of 0.33 L g-COD(-1) in the two-stage EGSB reactor system. The disturbance of the EGSB reactors was observed at a feed concentration above around 6.9 g-COD L(-1) because of higher influent COD concentration compared to other experiments.

Topological Magnon Bands in a Kagome Lattice Ferromagnet

There is great interest in finding materials possessing quasiparticles with topological properties. Such materials may have novel excitations that exist on their boundaries which are protected against disorder. We report experimental evidence that magnons in an insulating kagome ferromagnet can have a topological band structure. Our neutron scattering measurements further reveal that one of the bands is flat due to the unique geometry of the kagome lattice. Spin wave calculations show that the measured band structure follows from a simple Heisenberg Hamiltonian with a Dzyaloshinkii-Moriya interaction. This serves as the first realization of an effectively two-dimensional topological magnon insulator--a new class of magnetic material that should display both a magnon Hall effect and protected chiral edge modes.

Optical Characterization on Perovskite Zirconate Nanocrystals

We performed an optical study on the electronic properties of perovskite zirconate AZrO3 (A = Ca and Ba) nanocrystals (NCs), which depend strongly on the size of A ion as well as the post-annealing process. The zirconate NCs were synthesized in the combustion method, which was found to be quite effective for synthesizing highly orthorhombic CaZrO3 NCs in the sense that their grain sizes are relatively larger and as-synthesized NCs do not include any raw material phase in the XRD pattern, compared with the cubic BaZrO3 NCs. The room-temperature visible emission is commonly quite strong in both NCs. Interestingly, the dominance of the green-yellow emission over the violet-blue emission with increasing the post-annealing temperature (Tanneal) appears to be in agreement with the formation of the mid-gap state identified in the absorption spectra. While the optical bandgaps of NCs increased with increasing Tanneal, a systematic trend that the optical bandgap in the AZrO3 NCs decreased with the increasingly larger size of the A ion occurred. We discuss our findings in relation to the oxygen vacancy formation, lattice distortion, and size effect.

Ethnic differences in insulin sensitivity and beta-cell function among Asian men

BACKGROUND AND OBJECTIVES

Lean Asian Indians are less insulin sensitive compared with Chinese and Malays, but the pancreatic beta-cell function among these ethnic groups has yet to be studied in depth. We aimed to study beta-cell function in relation to insulin sensitivity among individuals of Chinese, Malay and Asian-Indian ethnicity living in Singapore.

SUBJECTS AND METHODS

This is a sub-group analysis of 59 normoglycemic lean (body mass index (BMI) <23 kg m(-)(2)) adult males (14 Chinese, 21 Malays and 24 Asian Indians) from the Singapore Adults Metabolism Study. Insulin sensitivity was determined using fasting state indices (homeostatic model assessment-insulin resistance), the euglycemic-hyperinsulinemic clamp (ISI-clamp) and a liquid mixed-meal tolerance test (LMMTT) (Matsuda insulin sensitivity index (ISI-Mat)). Beta-cell function was assessed using fasting state indices (homeostatic model assessment-beta-cell function) and from the LMMTT (insulinogenic index and insulin secretion index). The oral disposition index (DI), a measure of beta-cell function relative to insulin sensitivity during the LMMTT, was calculated as a product of ISI-Mat and insulin secretion index.

RESULTS

Asian Indians had higher waist circumference and percent body fat than Chinese and Malays despite similar BMI. Overall, Asian Indians were the least insulin sensitive whereas the Chinese were most insulin sensitive. Asian Indians had higher beta-cell function compared with Chinese or Malays but these were not statistically different. Malays had the highest incremental area under the curve for glucose during LMMTT compared with Asian Indians and Chinese. However, there were no significant ethnic differences in the incremental insulin area under the curve. The oral DI was the lowest in Malays, followed by Asian Indians and Chinese.

CONCLUSION

Among lean Asians, Chinese are the most insulin sensitive whereas Asian Indians are the least insulin sensitive. However, Malays demonstrate higher postprandial glucose excursion with lower beta-cell response compare with Chinese or Asian Indians. The paths leading to type 2 diabetes mellitus might differ between these Asian ethnic groups.

PCDHB14- and GABRB1-like nervous system developmental genes are altered during early neuronal differentiation of NCCIT cells treated with ethanol

Ethanol (EtOH) exposure during embryonic development causes dysfunction of the central nervous system (CNS). Here, we examined the effects of chronic EtOH on gene expression during early stages of neuronal differentiation. Human embryonic carcinoma (NCCIT) cells were differentiated into neuronal precursors/lineages in the presence or absence of EtOH and folic acid. Gene expression profiling and pathway analysis demonstrated that EtOH deregulates many genes and pathways that are involved in early brain development. EtOH exposure downregulated several important genes, such as PCDHB14, GABRB1, CTNND2, NAV3, RALDH1, and OPN5, which are involved in CNS development, synapse assembly, synaptic transmission, and neurotransmitter receptor activity. GeneGo pathway analysis revealed that the deregulated genes mapped to disease pathways that were relevant to fetal alcohol spectrum disorders (FASD, such as neurotic disorders, epilepsy, and alcohol-related disorders). In conclusion, these findings suggest that the impairment of the neurological system or suboptimal synapse formation resulting from EtOH exposure could underlie the neurodevelopmental disorders in individuals with FASD.

Electrochemical Performance of Electrophoretically Deposited Nanostructured LiMnPO4-Sucrose Derived Carbon Composite Electrodes for Lithium Ion Batteries

The present study reports an approach by which thin films of sucrose added olivine type LiMnPO4-Ccomposite and pristine LiMnPO4 is made by a technique of electrophoretic co-deposition in which pristine and composite samples were synthesized by a sol-gel route. These thin films with enhanced surface area is used to fabricate cathodes for rechargeable Li ion batteries. XRD confirms phase pure single crystalline orthorhombic structure. Transmission Electron Microscopy (TEM) images shows the carbon coating over LiMnPO4 and the particle size restricted in the nano regime. The presence of sp2 hybridized carbon on LiMnPO4 particles is confirmed by X-ray Photon spectroscopy (XPS). To explore the electrochemical behavior, cyclic voltammetry (CV) and cycling studies were performed. The specific capacity for LiMnPO4-C is found to be increased by 43% in comparison to the pristine LiMnPO4. It also exhibited 86% retention in capacity compared to the pristine LiMnPO4 (52%). The result indicates that a proper carbon coating can significantly improve the electronic conductivity and hence the specific capacity.

Electrochemical Performance of PbO2 and PbO2-CNT Composite Electrodes for Energy Storage Devices

In this work we report the electrochemical performance comparison of two new hybrid supercapacitors one based on graphene as negative electrode and lead dioxide thin film as positive electrode and the other with graphene as negative electrode and lead dioxide-carbon nanotube composite as positive electrode in 0.1 M KOH electrolyte. In the present work, PbO2 was synthesized using sol-gel method which is one of the promising materials for hybrid supercapacitors. The XRD confirmed the single phase of the PbO2 and the grain size is 39 nm which has been determined using Scherrer's formula. Thin films of PbO2, PbO2-CNT composite and graphene were coated on the titanium substrate by electrophoretic deposition. Further material characterisation has been carried out using SEM, TEM, XPS and electrochemical characterisation using CV, charge/discharge and electrochemical impedance spectroscopy (EIS) for obtaining energy density and power density, cyclic stability and internal resistance respectively. The present results revealed that PbO2-CNT composite/graphene asymmetric hybrid supercapacitor exhibits large specific capacitance and energy density over PbO2/graphene based system. The PbO2-CNT composite/graphene asymmetric hybrid supercapacitor exhibited maximum power density and energy density of 1200 W/Kg and 65 Wh/Kg respectively at a current density of 2 A/g. The PbO2-CNT composite/graphene asymmetric hybrid system exhibited excellent cycling stability with the capacitance retained 85% of its maximum value up to 3000 cycles.

A polymorphism in the porcine miR-208b is associated with microRNA biogenesis and expressions of SOX-6 and MYH7 with effects on muscle fibre characteristics and meat quality

MicroRNAs (miRNAs) encoded by the myosin heavy chain (MHC) genes are muscle-specific miRNAs (myomiRs) and regulate the expression of MHC isoforms in skeletal muscle. These miRNAs have been implicated in muscle fibre types and their characteristics by affecting the heterogeneity of myosin. In pigs, miR-208b and miR-499 are embedded in introns of MYH7 and MYH7b respectively. Here, we identified a novel single nucleotide polymorphism (SNP) in intron 30 of MYH7 by which porcine miR-208b is encoded. Based on the association study using a total of 487 pigs including Berkshire (n = 164), Landrace (n = 121) and Yorkshire (n = 202), the miR-208b SNP (g.17104G>A) had significant effects on the proportions of types I and IIb fibre numbers (P < 0.010) among muscle fibre characteristics and on drip loss (P = 0.012) in meat quality traits. Moreover, the SNP affected the processing of primary miR-208b into precursor miR-208b with a marginal trend towards significance (P = 0.053), thereby leading to significant changes in the levels of mature miR-208b (P = 0.009). These SNP-dependent changes in mature miR-208b levels were negatively correlated with the expression levels of its target gene, SOX-6 (P = 0.038), and positively associated with the expression levels of its host gene, MYH7 (P = 0.046). Taken together, our data suggest that the porcine miR-208b SNP differentially represses the expression of SOX-6 by regulating miRNA biogenesis, thereby affecting the expression of MYH7 and the traits of muscle fibre characteristics and meat quality.

Outcome of excision of oral erythroplakia

Oral erythroplakia is a precancerous lesion with high malignant potential, and resection is the recommended treatment. We designed a retrospective study to analyse the outcome of treatment in patients who had operations for oral erythroplakia. A total of 84 patients (74 men and 10 women, mean (SD) age 54 (12) years, range 29-83) were enrolled. Histopathologically the diagnoses were invasive carcinoma (n=3), dysplasia/carcinoma in situ (n=61), and squamous hyperplasia (n=20), and all patients were treated by carbon dioxide laser excision. There was no postoperative malignant transformation, but invasive carcinoma found after initial excision (n=3) was treated by further radical excision. The mean (SD) follow-up period was 46 (29) months (range 1-124), The postoperative recurrent rate was 14/84 (16.7%). The area of oral erythroplakia was the only factor associated with postoperative recurrence on univariate analysis, and was also the only independent factor that predicted postoperative recurrence in multivariate logistic regression analysis. An area exceeding 80 mm2 had the best predictive value (sensitivity=0.71, specificity=0.67) with a 5.1 times increased risk (odds ratio=5.1, CI 95% 1.45 to 18.05, p=0.01) of recurrence. Laser excision is effective for oral erythroplakia that is still confined to dysplasia of any degree, with low morbidity. The area of oral erythroplakia is a predictive factor for postoperative recurrence.

Metal oxide coated lithium cobalt fluorophosphate cathode materials for lithium secondary batteries--effect of aging and temperature

Lithium cobalt fluorophosphate (Li2CoPO4F) is a promising 5 V class cathode material for lithium secondary batteries. In this study, surface coating with ZrO2 improved the electrochemical activity of Li2CoPO4F with a maximum discharge capacity of 144 mA h g(-1). The effectiveness of ZrO2 coating was evaluated using aging analysis with a commercial electrolyte, i.e., 1 M LiPF6 in EC:DMC (1:1, v/v). The metal ion dissolution was reduced to 1/8th of that observed in the non-coated Li2CoPO4F. It was found that the thin coating layer had less or no contribution to the additional resistance for the cell, both at an open circuit potential and at a fully charged state; hence, the capacity of the cell was retained over cycling. Elevated temperature aging did not affect the intrinsic property of the coated Li2CoPO4F, as observed from the complete anodic and cathodic peaks from cyclic voltammetry studies after 30 days of storage at 50 degrees C. An increase in impedance was observed for aged cells, which could be due to the thick SEI layer formed during storage. The ZrO2 coating over Li2CoPO4F was crucial for the improved performance of electrode active material at higher operating potentials of up to 5.2 V.

Preparation and characterization of chlorine doped Li3V2(PO4)3 as high rate cathode active material for lithium secondary batteries

Monoclinic Li3V2(PO4)2.99Cl0.01 was synthesized using the conventional solid state method and the X-ray diffraction pattern was indexed based on P2(1)/n space group. The sharp cyclic voltammetric curves clearly revealed three lithium extraction/insertion processes at approximately 3.64, 3.72, 4.13, and 4.58 V during the anodic scan and 3.96, 3.58, and 3.48 V during the cathodic scan. Charge/discharge studies showed reduced electrolyte decomposition contribution in the case of the chlorine doped Li3V2(PO4)2.99Cl0.01 sample with an initial capacity of 176 mA h g(-1) at a 0.1 C current rate. The chlorine doped Li3V2(PO4)3 sample showed an increased capacity retention with an increase in current rate, even at a very high C-rate (20 C), than the pristine and carbon coated samples. The pristine and carbon coated Li3V2(PO4)3 samples showed a lower capacity retention of 71% and 84%, respectively, at a current rate of 0.1 C. In contrast, the chlorine doped Li3V,(PO4)3 sample retained 87% of the initial capacity (176 mA h g(-1)) at the same current rate but with a higher coulombic efficiency of 91%. The enhanced capacity retention for the chlorine doped Li3V2(PO4)3 was attributed to the reduction in polarization and decreased charge transfer resistance of the electrode.

The Reaction Mechanism and Capacity Degradation Model in Lithium Insertion Organic Cathodes, Li2C6O6, Using Combined Experimental and First Principle Studies

Herein, we explore the capacity degradation of dilithium rhodizonate salt (Li2C6O6) in lithium rechargeable batteries based on detailed investigations of the lithium de/insertion mechanism in Li2C6O6 using both electrochemical and structural ex situ analyses combined with first-principles calculations. The experimental observations indicate that the LixC6O6 electrode undergoes multiple two-phase reactions in the composition range of 2 ≤ x ≤ 6; however, the transformations in the range 2 ≤ x ≤ 4 involve a major morphological change that eventually leads to particle exfoliation and the isolation of active material. Through first-principles analysis of LixC6O6 during de/lithiation, it was revealed that particle exfoliation is closely related to the crystal structural changes with lithium deinsertion from C6O6 interlayers of the LixC6O6. Among the lithium ions found at various sites, the extraction of lithium from C6O6 interlayers at 2 ≤ x ≤ 4 decreases the binding force between the C6O6 layers, promoting the exfoliation of C6O6 layers and pulverization at the electrode, which degrades capacity retention.