bluuebunny/crossref_metadata_2025 huggingface dataset:
STAT4 Deficiency Reduces Obesity-Induced Insulin Resistance and Adipose Tissue Inflammation
Authors: Dobrian Anca D. , Galkina Elena V. , Ma Qian , Hatcher Margaret , Aye Sabai Myo , Butcher Mathew J. , Ma Kaiwen , Haynes Bronson A. , Kaplan Mark H. , Nadler Jerry L.
Published: August 2013

Signal transducer and activator of transcription (STAT) 4 is one of the seven members of the STAT family. STAT4 has a prominent role in mediating interleukin-12–induced T-helper cell type 1 lineage differentiation. T cells are key players in the maintenance of adipose tissue (AT) inflammation. The role of STAT4 in obesity and AT inflammation is unknown. We sought to determine the role of STAT4 in AT inflammation in obesity-induced insulin resistance. We studied STAT4-null mice on the C57Bl6/J background. We have found that STAT4−/−C57Bl6/J mice develop high-fat diet–induced obesity (DIO) similar to wild-type controls, but that they have significantly improved insulin sensitivity and better glucose tolerance. Using flow cytometry and real-time PCR, we show that STAT4−/− mice with DIO produce significantly reduced numbers of inflammatory cytokines and chemokines in adipocytes, have reduced numbers of CD8+ cells, and display increased alternative (M2) macrophage polarization. CD8+ cells, but not CD4+ cells, from STAT4−/− mice displayed reduced in vitro migration. Also, we found that adipocyte inflammation is reduced and insulin signaling is improved in STAT4−/− mice with DIO. We have identified STAT4 as a key contributor to insulin resistance and AT inflammation in DIO. Targeting STAT4 activation could be a novel approach to reducing AT inflammation and insulin resistance in obesity.
Lactate-Induced Release of GABA in the Ventromedial Hypothalamus Contributes to Counterregulatory Failure in Recurrent Hypoglycemia and Diabetes
Authors: Chan Owen , Paranjape Sachin A. , Horblitt Adam , Zhu Wanling , Sherwin Robert S.
Published: August 2013

Suppression of GABAergic neurotransmission in the ventromedial hypothalamus (VMH) is crucial for full activation of counterregulatory responses to hypoglycemia, and increased γ-aminobutyric acid (GABA) output contributes to counterregulatory failure in recurrently hypoglycemic (RH) and diabetic rats. The goal of this study was to establish whether lactate contributes to raising VMH GABA levels in these two conditions. We used microdialysis to deliver artificial extracellular fluid or l-lactate into the VMH and sample for GABA. We then microinjected a GABAA receptor antagonist, an inhibitor of lactate transport (4CIN), or an inhibitor of lactate dehydrogenase, oxamate (OX), into the VMH prior to inducing hypoglycemia. To assess whether lactate contributes to raising GABA in RH and diabetes, we injected 4CIN or OX into the VMH of RH and diabetic rats before inducing hypoglycemia. l-lactate raised VMH GABA levels and suppressed counterregulatory responses to hypoglycemia. While blocking GABAA receptors did not prevent the lactate-induced rise in GABA, inhibition of lactate transport or utilization did, despite the presence of lactate. All three treatments restored the counterregulatory responses, suggesting that lactate suppresses these responses by enhancing GABA release. Both RH and diabetic rats had higher baseline GABA levels and were unable to reduce GABA levels sufficiently to fully activate counterregulatory responses during hypoglycemia. 4CIN or OX lowered VMH GABA levels in both RH and diabetic rats and restored the counterregulatory responses. Lactate likely contributes to counterregulatory failure in RH and diabetes by increasing VMH GABA levels.
Acute Metabolic Effects of Exenatide in Patients With Type 1 Diabetes With and Without Residual Insulin to Oral and Intravenous Glucose Challenges
Authors: Ghazi Tara , Rink Linda , Sherr Jennifer L. , Herold Kevan C.
Published: August 2013

OBJECTIVE

Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the gastrointestinal tract. Treatment with GLP-1 analogs has proven to be of clinical use for patients with type 2 diabetes. Patients with type 1 diabetes, particularly those with residual β-cell function, may also respond to treatment, but the acute metabolic effects of GLP-1 analogs on these patients in reaction to both oral and intravenous glucose challenges are not well understood.

RESEARCH DESIGN AND METHODS

Seventeen patients with type 1 diabetes, half of whom had residual insulin production, underwent two mixed-meal tolerance tests (MMTTs) and two intravenous glucose tolerance tests (IVGTTs), with and without pretreatment with exenatide. No exogenous bolus insulin was administered for the studies. Glucose excursions, insulin secretion rates (ISRs), and levels of glucagon, endogenous GLP-1, and gastric inhibitory polypeptide were measured after the meal or glucose loads.

RESULTS

During the MMTT, glucose levels were suppressed with exenatide in patients with or without residual insulin production (P = 0.0003). Exenatide treatment did not change the absolute ISR, but the ISR to glucose levels were increased (P = 0.0078). Gastric emptying was delayed (P = 0.0017), and glucagon was suppressed (P = 0.0015). None of these hormonal or glucose changes were detected during the IVGTT with exenatide administration.

CONCLUSIONS

Exenatide showed a significant antidiabetogenic effect prior to an oral meal in patients with type 1 diabetes involving glucagon suppression and gastric emptying, while preserving increased insulin secretion. GLP-1 analogs may be useful as an adjunctive treatment in type 1 diabetes.
Dietary Energy Intake Is Associated With Type 2 Diabetes Risk Markers in Children
Authors: Donin Angela S. , Nightingale Claire M. , Owen Christopher G. , Rudnicka Alicja R. , Jebb Susan A. , Ambrosini Gina L. , Stephen Alison M. , Cook Derek G. , Whincup Peter H.
Published: August 2013

OBJECTIVE

Energy intake, energy density, and nutrient intakes are implicated in type 2 diabetes risk in adults, but little is known about their influence on emerging type 2 diabetes risk in childhood. We examined these associations in a multiethnic population of children.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study of 2,017 children predominantly of white European, South Asian, and black African-Caribbean origin aged 9–10 years who had a detailed 24-h dietary recall and measurements of body composition and provided a fasting blood sample for measurements of plasma glucose, HbA1c, and serum insulin; homeostasis model assessment of insulin resistance was also derived.

RESULTS

Energy intake was positively associated with insulin resistance. After the removal of 176 participants with implausible energy intakes (unlikely to be representative of habitual intake), energy intake was more strongly associated with insulin resistance and was also associated with glucose and fat mass index. Energy density was also positively associated with insulin resistance and fat mass index. However, in mutually adjusted analyses, the associations for energy intake remained while those for energy density became nonsignificant. Individual nutrient intakes showed no associations with type 2 diabetes risk markers.

CONCLUSIONS

Higher total energy intake was strongly associated with high levels of insulin resistance and may help to explain emerging type 2 diabetes risk in childhood. Studies are needed to establish whether reducing energy intake produces sustained favorable changes in insulin resistance and circulating glucose levels.
Drug Interactions with Complementary and Alternative Medicine and Dietary Supplements
Authors: Basnet S , Adhikary P , Aryal B
Published: August 2013

Complementary and Alternative Medicine (CAM) is a group of diverse medical and health care systems, practices and products that are not presently considered to be a part of conventional medicine. Primary reasons for the use are to relieve symptoms associated with chronic, even terminal illnesses or the side effects of conventional treatments or having a holistic health philosophy or cultural belief. In Nepal, the Ayurvedic system is most widespread and reasons for this had no or less side effect as well as more effective for chronic patients. Drug interactions can occur at the pharmaceutical, pharmacody­namic, or pharmacokinetic level. Herbals and dietary supplements containing St John’s Wort (Hypericum perforatum), ginkgo (Ginkgo biloba), kava (Piper methysticum), digitalis (Digitalis purpurea), willow (Salix alba), magnesium, calcium and iron were documented to have the most interactions with individual medications. Warfarin, insulin, aspirin, digoxin, and ticlopidine had the greatest number of reported interactions with those preparations. Since, half of the Nepalese populations use CAM therapy, the healthcare professionals should pay attention towards such interactions. DOI: http://dx.doi.org/10.3126/jcmc.v3i2.8433 Journal of Chitwan Medical College Vol.3(2) 2013 1-3
Antenatal Care Practices in Hilly Area of Eastern Region of Nepal
Authors: Sah RB , Gauray K , Baral DD , Jha N , Pokharel PK
Published: August 2013

Antenatal care is provided during pregnancy to save lives of mother and foetus. The World Health Organization recommends four focused visits as sufficient for normal pregnancy. The objective of this study was to find out the antenatal care practices and its impact on birth outcome.The cross-sectional study was conducted from 28th March to 10th April, 2013 among the residents of Dhankuta municipality where 246 households were taken as subjects. Convenient purposive sampling technique was applied. Semi-structured questionnaire was used and face to face interview was conducted. Chi-square test was applied to find out the significant difference between sociodemographic characteristics and outcome variable i.e. birth outcome & antenatal care visits. Almost eighty eight percent of respondents attended ANC visits.The findings revealed that even though the fourth ANC visit was (82.4%), almost 82.5% of the pregnant women took the tetanus toxoid (TT) injections, about 81.7% received iron tablets and nearly 57.7% received albendazole. Women with School Leaving Certificate and higher ed­ucation level are more likely to ANC visits (95.4%) than women with below SLC (87.9%) and no education (66.7%). Hindu women are more likely to have ANC visits (91.2%) compared to women of other religion (47.4%) (P<0.001). Furthermore, economic variable shows stronger association with ANC visits (P<0.001). We conclude that the women of the surveyed communities have placed antenatal care as priority. Lack of money and education led some of the respondents not to attend the recommended antenatal care visits. Antenatal care checkup is important for favourable birth outcome. DOI: http://dx.doi.org/10.3126/jcmc.v3i2.8435 Journal of Chitwan Medical College Vol.3(2) 2013 12-15
Causative Agents and Susceptibility of Antimicrobials among Suspected Females with Urinary Tract Infection in Tertiary Care Hospitals of Western Nepal
Authors: Thapa P , Parajuli K , Poudel A , Thapa A , Manandhar B , Laudari D , Malla HB , Katiwada R
Published: August 2013

Urinary Tract Infection (UTI) is a common and serious health problem affecting many people each year around the World especially females. Therapy of UTI relies on the predictability of the agents causing UTI and knowledge of their antimicro­bial susceptibility patterns. A retrospective cross-sectional study was conducted in two major hospitals of Western Nepal. Tools for data collection were a data collection form. Total 400 patient’s file with suspected UTI were reviewed, out of which 173 (43.3 %) of the suspected samples showed presence of potential pathogens causing UTI. UTI was mostly prevalent in females of age group 21-30. Escherichia coli (E. coli) was the predominant (65.1%) bacterial pathogen. Amikacin was found to be most sensitive antimicrobial followed by Nitrofurantoin and Gentamcin. Ampicillin showed the higher percentage of resistant, compared to other antimicrobials. As drug resistance among bacterial pathogens is an evolving process, regular surveillance and monitoring is necessary to provide effective treatment of UTIs. DOI: http://dx.doi.org/10.3126/jcmc.v3i2.8436 Journal of Chitwan Medical College Vol.3(2) 2013 16-19
Antioxidant Activity of Selected Natural Medicines used in Nepal
Authors: Baral KP , Basnet P
Published: August 2013

Diminished antioxidant defence or increased production of reactive oxygen and nitrogen species in the biological system can result into oxidative stress which can cause damage to deoxyribonucleic acid (DNA), proteins, lipids and as a result different disease states arise like cancer, neurodegenerative diseases, rheumatoid arthritis. Antioxidants from different plant resources can significantly delay or prevent oxidation of the substrate and hence prevents from various diseases. Therefore, present research was focused in search of potent natural antioxidants. For the study, methanolic extracts of twenty-five common natural medicines, mostly spices were screened using 1,1–diphenyl–2–picrylhydrazyl (DPPH) radical for their antioxidative activities. Among them, extracts of Chebulae Fructus, Terminalia Billericae Fructus, Phyllanthi Fructus, Cinnamomi Cortex, Arecae Semen, Pericarpium Punicae Granati, Syzygiae Fructus, Rhei Rhizoma, Pterocarpi Lignum and Santali Lignum Albi showed potent antioxidative activity with EC50 values being 1.5, 2.1, 1.4, 2, 1.5, 1.45, 2.7, 2.9, 3, 3.8 μg/mL, respectively. Ascorbic acid (EC50: 2.6 μg/mL) was used as positive control. Therefore, consumers can increase their intake of foods rich in antioxidant compounds that can lower the risk of chronic health problems DOI: http://dx.doi.org/10.3126/jcmc.v3i2.8439 Journal of Chitwan Medical College Vol.3(2) 2013 27-31
A Case Report on Sheehan's Syndrome
Authors: Pokharel S , Jha SC , Maskey D , Shrestha B , Poudel P , Shrestha B , Dhital BM
Published: August 2013

Sheehan’s syndrome is a well-known cause of panhypopituitarism secondary to pituitary apoplexy, that generally occurs after an intra- or postpartum bleeding episode characterized by massive hemorrhage and hypovolemic shock. The diagnosis can be difficult and is often formulated after some years from the syndrome occurrence. We report the case of a woman with a relatively early diagnosed Sheehan’s syndrome associated with amenorrhoea and secondary hypothyriodism complicated by postpartum hemorrhage. DOI: http://dx.doi.org/10.3126/jcmc.v3i2.8444 Journal of Chitwan Medical College Vol.3(2) 2013 49-50
Swooping in the Suburbs; Parental Defence of an Abundant Aggressive Urban Bird against Humans
Authors: Lees Daniel , Sherman Craig , Maguire Grainne , Dann Peter , Cardilini Adam , Weston Michael
Published: August 2013

Masked Lapwings, Vanellus miles, often come into ‘conflict’ with humans, because they often breed in close proximity to humans and actively defend their ground nests through aggressive behaviour, which typically involves swooping. This study examined whether defensive responses differed when nesting birds were confronted with different human stimuli (‘pedestrian alone’ vs. ‘person pushing a lawn mower’ approaches to nests) and tested the effectiveness of a commonly used deterrent (mock eyes positioned on the top or back of a person’s head) on the defensive response. Masked Lapwings did not swoop closer to a person with a lawn mower compared with a pedestrian, but flushed closer and remained closer to the nest in the presence of a lawn mower. The presence of eye stickers decreased (pedestrians) and increased (lawn mowers) swooping behaviour. Masked Lapwings can discriminate between different human activities and adjust their defensive behaviour accordingly. We also conclude that the use of eye stickers is an effective method to mitigate the human-lapwing ‘conflict’ in some, but not all, circumstances.
An Evolutionary Theory of Suicide
Authors: Szentes Balázs , Thomas Caroline
Published: August 2013

We analyze a model in which individuals have hereditary reproductive types. The reproductive value of an individual is determined by her reproductive type and the amount of resources she can access. We introduce the possibility of suicide and assume it is also a genetic trait that interacts with the reproductive type of an individual. The main result of the paper is that populations where suicide is possible grow faster than other populations.
Effects of Compulsory Schooling on Mortality: Evidence from Sweden
Authors: Fischer Martin , Karlsson Martin , Nilsson Therese
Published: August 2013

Theoretically, there are several reasons to expect education to have a positive effect on health. Empirical research suggests that education can be an important health determinant. However, it has not yet been established whether education and health are indeed causally related, and the effects found in previous studies may be partially attributable to methodological weaknesses. Moreover, existing evidence on the education-health relationship generally uses information of fairly recent schooling reforms, implying that health outcomes are observed only over a limited time period. This paper examines the effect of education on mortality using information on a national roll-out of a reform leading to one extra year of compulsory schooling in Sweden. In 1936, the national government made a seventh school year compulsory; however, the implementation was decided at the school district level, and the reform was implemented over 12 years. Taking advantage of the variation in the timing of the implementation across school districts, by using county-level proportions of reformed districts, census data and administrative mortality data, we find that the extra compulsory school year reduced mortality. In fact, the mortality reduction is discernible already before the age of 30 and then grows in magnitude until the age of 55–60.
How Does the Financial Crisis Affect Volatility Behavior and Transmission Among European Stock Markets?
Authors: Ben Slimane Faten , Mehanaoui Mohamed , Kazi Irfan
Published: August 2013

The spread of the global financial crisis of 2008/2009 was rapid, and impacted the functioning and the performance of financial markets. Due to the importance of this phenomenon, this study aims to explain the impact of the crisis on stock market behavior and interdependence through the study of the intraday volatility transmission. This paper investigates the patterns of linkage dynamics among three European stock markets—France, Germany, and the UK—during the global financial crisis, by analyzing the intraday dynamics of linkages among these markets during both calm and turmoil phases. We apply a VAR-EGARCH (Vector Autoregressive Exponential General Autoregressive Conditional Heteroscedasticity) framework to high frequency five-minute intraday returns on selected representative stock indices. We find evidence that interrelationship among European markets increased substantially during the period of crisis, pointing to an amplification of spillovers. In addition, during this period, French and UK markets herded around German market, possibly explained by behavior factors influencing the stock markets on or near dates of extreme events. Germany was identified as the hub of financial and economic activity in Europe during the period of study. These findings have important implications for both policymakers and investors by contributing to better understanding the transmission of financial shocks in Europe.
Cyclic Deformation of Ultra-Fine Grained Commercial Purity Aluminum Processed by Accumulative Roll-Bonding
Authors: Kwan Charles , Wang Zhirui
Published: August 2013

Accumulative Roll-Bonding (ARB) is one of the more recently developed techniques capable of producing bulk ultra-fine grained (ufg) metals. There are still many aspects of the behavior of ufg metals that lacks an in-depth understanding, such as a generalized view of the factors that govern the cyclic deformation mechanism(s). This study aims to advance the understanding of the cyclic deformation behavior of ufg metals through the systematic investigation of ARB processed aluminum upon cyclic loading. It was found that the cyclic softening response often reported for ufg metals is largely influenced by the microstructure stability as the cyclic softening response is facilitated by grain coarsening which becomes inhibited with highly stable microstructure. On one hand, shear bands resembling braids of dislocations trespassing multiple grains have been observed to operate for the accommodation of the imposed cyclic strain in cases where grain coarsening is largely restricted. On the other hand, it was found that the microstructure stability can be overcome at higher applied cyclic plastic strain levels, leading to grain coarsening and thus a cyclic softening response. The findings in this study have further confirmed that the cyclic softening behavior found in many ufg metals, which may be detrimental in practical applications, can be inhibited by improvements in the microstructure stability.
Study of Radio Frequency Plasma Treatment of PVDF Film Using Ar, O2 and (Ar + O2) Gases for Improved Polypyrrole Adhesion
Authors: Kaynak Akif , Mehmood Tariq , Dai Xiujuan , Magniez Kevin , Kouzani Abbas
Published: August 2013

Improvement of the binding of polypyrrole with PVDF (polyvinylidene fluoride) thin film using low pressure plasma was studied. The effects of various plasma gases i.e., Ar, O2 and Ar + O2 gases on surface roughness, surface chemistry and hydrophilicity were noted. The topographical change of the PVDF film was observed by means of scanning electron microscopy and chemical changes by X-ray photoelectron spectroscopy, with adhesion of polypyrrole (PPy) by abrasion tests and sheet resistance measurements. Results showed that the increase in roughness and surface functionalization by oxygen functional groups contributed to improved adhesion and Ar + O2 plasma gave better adhesion.
Insights into the Toxicological Properties of a Low Molecular Weight Fraction from Zoanthus sociatus (Cnidaria)
Authors: Domínguez-Pérez Dany , Diaz-Garcia Carlos , García-Delgado Neivys , Sierra-Gómez Yusvel , Castañeda Olga , Antunes Agostinho
Published: August 2013

The phylum Cnidaria is an ancient group of venomous animals, specialized in the production and delivery of toxins. Many species belonging to the class Anthozoa have been studied and their venoms often contain a group of peptides, less than 10 kDa, that act upon ion channels. These peptides and their targets interact with high affinity producing neurotoxic and cardiotoxic effects, and even death, depending on the dose and the administration pathway. Zoanthiniaria is an order of the Subclass Hexacorallia, class Anthozoa, and unlike sea anemone (order Actiniaria), neither its diversity of toxins nor the in vivo effects of the venoms has been exhaustively explored. In this study we assessed some toxicological tests on mice with a low molecular weight fraction obtained by gel filtration in Sephadex G-50 from Zoanthus sociatus crude extract. The gel filtration chromatogram at 280 nm revealed two major peaks, the highest absorbance corresponding to the low molecular weight fraction. The toxicological effects seem to be mostly autonomic and cardiotoxic, causing death in a dose dependent manner with a LD50 of 792 μg/kg. Moreover, at a dose of 600 μg/kg the active fraction accelerated the KCl-induced lethality in mice.
Development of Synechocystis sp. PCC 6803 as a Phototrophic Cell Factory
Authors: Yu Yi , You Le , Liu Dianyi , Hollinshead Whitney , Tang Yinjie , Zhang Fuzhong
Published: August 2013

Cyanobacteria (blue-green algae) play profound roles in ecology and biogeochemistry. One model cyanobacterial species is the unicellular cyanobacterium Synechocystis sp. PCC 6803. This species is highly amenable to genetic modification. Its genome has been sequenced and many systems biology and molecular biology tools are available to study this bacterium. Recently, researchers have put significant efforts into understanding and engineering this bacterium to produce chemicals and biofuels from sunlight and CO2. To demonstrate our perspective on the application of this cyanobacterium as a photosynthesis-based chassis, we summarize the recent research on Synechocystis 6803 by focusing on five topics: rate-limiting factors for cell cultivation; molecular tools for genetic modifications; high-throughput system biology for genome wide analysis; metabolic modeling for physiological prediction and rational metabolic engineering; and applications in producing diverse chemicals. We also discuss the particular challenges for systems analysis and engineering applications of this microorganism, including precise characterization of versatile cell metabolism, improvement of product rates and titers, bioprocess scale-up, and product recovery. Although much progress has been achieved in the development of Synechocystis 6803 as a phototrophic cell factory, the biotechnology for “Compounds from Synechocystis” is still significantly lagging behind those for heterotrophic microbes (e.g., Escherichia coli).
Anti-Inflammatory Components of the Starfish Astropecten polyacanthus
Authors: Thao Nguyen , Cuong Nguyen , Luyen Bui , Quang Tran , Hanh Tran , Kim Sohyun , Koh Young-Sang , Nam Nguyen , Van Kiem Phan , Van Minh Chau , Kim Young
Published: August 2013

Inflammation is important in biomedical research, because it plays a key role in inflammatory diseases including rheumatoid arthritis and other forms of arthritis, diabetes, heart disease, irritable bowel syndrome, Alzheimer’s disease, Parkinson’s disease, allergies, asthma, and even cancer. In the present study, we describe the inhibitory effect of crude extracts and steroids isolated from the starfish Astropecten polyacanthus on pro-inflammatory cytokine (Interleukin-12 (IL-12) p40, interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α)) production in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs). Among those tested, compounds 5 and 7 showed potent inhibitory effects on the production of all three pro-inflammatory cytokines with IC50 values ranging from 1.82 ± 0.11 to 7.00 ± 0.16 μM. Potent inhibitory activities were also observed for compound 1 on the production of IL-12 p40 and IL-6 with values of 3.96 ± 0.12 and 4.07 ± 0.13 μM, respectively, and for compounds 3 and 4 on the production of IL-12 p40 with values of 6.55 ± 0.18 and 5.06 ± 0.16 μM, respectively. Moreover, compounds 2 (IC50 = 34.86 ± 0.31 μM) and 6 (IC50 = 79.05 ± 2.05 μM) exhibited moderate inhibitory effects on the production of IL-12 p40, whereas compounds 3 (IC50 = 22.80 ± 0.21 μM) and 4 (IC50 = 16.73 ± 0.25 μM) moderately inhibited the production of TNF-α and IL-6, respectively.
The Synthesis and the Biological Evaluation of New Thiazolidin-4-one Derivatives Containing a Xanthine Moiety
Authors: Lupascu Florentina , Dragostin Oana , Foia Liliana , Lupascu Dan , Profire Lenuta
Published: August 2013

Starting from theophylline (1,3-dimethylxanthine) new thiazolidin-4-one derivatives 7a1–7, 7b1–7 have been synthesized as potential antidiabetic drugs. The structure of the new derivatives was confirmed using spectral methods (FT-IR, 1H-NMR, 13C-NMR). The in vitro antioxidant potential of the synthesized compounds was evaluated according to the ferric reducing power, the total antioxidant activity and the DPPH and ABTS radical scavenging assays. Reactive oxygen species (ROS) and free radicals are considered to be implicated in a variety of pathological events, such as diabetes mellitus and its micro- and macrovascular complications. The results of chemical modulation of the thiazolidin-4-one intermediaries 6a, 6b through condensation with several aromatic aldehydes is the improvement of the antioxidant effect. All benzylidenethiazolidin-4-one derivatives 7a1–7, 7b1–7 are more active than their parent thiazolidin-4-ones. The most active compounds are the ones obtained by reaction of condensation with 4-hydroxybenzaldehyde (compounds 7a5, 7a6), 4-dimethylaminobenzaldehyde (compounds 7a6, 7b6) and 2-nitrobenzaldehyde (compounds 7a7, 7b7).
Enzymatic Synthesis of Extremely Pure Triacylglycerols Enriched in Conjugated Linoleic Acids
Authors: Cao Yu , Wang Weifei , Xu Yang , Yang Bo , Wang Yonghua
Published: August 2013

This work was objectively targeted to synthesize extremely pure triacylglycerols (TAG) enriched in conjugated linoleic acids (CLAs) for medical and dietetic purposes. Extremely pure CLA-enriched TAG was successfully synthesized by using the multi-step process: TAG was primarily synthesized by lipase-catalyzed esterification of CLA and glycerol and then the lower glycerides [monoacylglycerol (MAG) and diacylglycerol (DAG)] in the esterification mixtures was hydrolyzed to free fatty acids (FFAs) by a mono- and di-acylglycerol lipase (lipase SMG1), finally, the FFAs were further separated from TAG by low temperature (150 °C) molecular distillation. The operation parameters for the lipase SMG1-catalyzed hydrolysis were optimized using response surface methodology based on the central composite rotatable design (CCRD). The operation parameters included water content, pH and reaction temperature and all of these three parameters showed significant effects on the hydrolysis of lower glycerides. The optimal conditions were obtained with a water content of 66.4% (w/w, with respect to oil mass), pH at 5.7 and 1 h of reaction time at 19.6 °C. Under these conditions, the content of lower glycerides in the reaction mixture decreased from 45.2% to 0.3% and the purity of CLA-enriched TAG reached 99.7%. Further purification of TAG was accomplished by molecular distillation and the final CLA-enriched TAG product yielded 99.8% of TAG. These extremely pure CLA-enriched TAG would be used for in vivo studies in animals and humans in order to get speciﬁc information concerning CLA metabolism.
New Compounds Induce Brassinosteroid Deficient-like Phenotypes in Rice
Authors: Matsumoto Tadashi , Yamada Kazuhiro , Iwasaki Ikuko , Yoshizawa Yuko , Oh Keimei
Published: August 2013

Brassinosteroids (BRs) are steroidal plant hormones with potent plant growth promoting activity. Because BR-deficient mutants of rice exhibit altered plant architecture and important agronomic traits, we conducted a systemic search for specific inhibitors of BR biosynthesis to manipulate the BR levels in plant tissues. Although previous studies have been conducted with BR biosynthesis inhibitors in dicots, little is known regarding the effects of BR biosynthesis inhibition in monocot plants. In this work, we used potent inhibitors of BR biosynthesis in Arabidopsis, and we performed a hydroponic culture of rice seedlings to evaluate the effects of BR biosynthesis inhibition. Among the test compounds, we found that 1-[[2-(4-Chlorophenyl)-4-(phenoxymethyl)-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole (1) is a potent inhibitor that could induce phenotypes in rice seedlings that were similar to those observed in brassinosteroid deficient plants. The IC50 value for the retardation of plant growth in rice seedlings was approximately 1.27 ± 0.43 μM. The IC50 value for reducing the bending angle of the lamina joint was approximately 0.55 ± 0.15 μM.
An Embedded Simplified Fuzzy ARTMAP Implemented on a Microcontroller for Food Classification
Authors: Garcia-Breijo Eduardo , Garrigues Jose , Sanchez Luis , Laguarda-Miro Nicolas
Published: August 2013

In the present study, a portable system based on a microcontroller has been developed to classify different kinds of honeys. In order to do this classification, a Simplified Fuzzy ARTMAP network (SFA) implemented in a microcontroller has been used. Due to memory limits when working with microcontrollers, it is necessary to optimize the use of both program and data memory. Thus, a Graphical User Interface (GUI) for MATLAB® has been developed in order to optimize the necessary parameters to programme the SFA in a microcontroller. The measures have been carried out by potentiometric techniques using a multielectrode made of seven different metals. Next, the neural network has been trained on a PC by means of the GUI in Matlab using the data obtained in the experimental phase. The microcontroller has been programmed with the obtained parameters and then, new samples have been analysed using the portable system in order to test the model. Results are very promising, as an 87.5% recognition rate has been achieved in the training phase, which suggests that this kind of procedures can be successfully used not only for honey classification, but also for many other kinds of food.
A Comprehensive Review of Semiconductor Ultraviolet Photodetectors: From Thin Film to One-Dimensional Nanostructures
Authors: Sang Liwen , Liao Meiyong , Sumiya Masatomo
Published: August 2013

Ultraviolet (UV) photodetectors have drawn extensive attention owing to their applications in industrial, environmental and even biological fields. Compared to UV-enhanced Si photodetectors, a new generation of wide bandgap semiconductors, such as (Al, In) GaN, diamond, and SiC, have the advantages of high responsivity, high thermal stability, robust radiation hardness and high response speed. On the other hand, one-dimensional (1D) nanostructure semiconductors with a wide bandgap, such as β-Ga2O3, GaN, ZnO, or other metal-oxide nanostructures, also show their potential for high-efficiency UV photodetection. In some cases such as flame detection, high-temperature thermally stable detectors with high performance are required. This article provides a comprehensive review on the state-of-the-art research activities in the UV photodetection field, including not only semiconductor thin films, but also 1D nanostructured materials, which are attracting more and more attention in the detection field. A special focus is given on the thermal stability of the developed devices, which is one of the key characteristics for the real applications.
Social Capital and Walkability as Social Aspects of Sustainability
Authors: Rogers Shannon , Gardner Kevin , Carlson Cynthia
Published: August 2013

The concepts of sustainability and sustainable development are frequently described as having three main components, sometimes referred to as the three pillars or the triple bottom line: environmental, economic, and social. Because of an historical focus in the sustainability field on correcting environmental problems, much consideration has been given to environmental issues, especially how they interface with economic ones. Frequently mentioned but rarely examined, the social aspects of sustainability have been considered the weakest and least described pillar. After a brief review of existing concepts and theories, this paper uses a case study approach to examine the third pillar more comprehensively and offers social capital as one measure of social sustainability. Specifically, social capital was used to measure the social-environmental interface of communities. The positive correlation between aspects of the built environment, specifically walkability, and social capital suggests that measuring a social aspect of sustainability may be feasible, especially in the context of community development.
Public Understanding of Climate Change as a Social Dilemma
Authors: Capstick Stuart
Published: August 2013

Climate change is often referred to as one of the most complicated challenges facing humanity, characterised in various literatures as a social dilemma operating at multiple scales (individual, national, international). The present study considers the ways in which members of the public interpret climate change in these terms, drawing on data from multiple datasets, both qualitative and quantitative, from 1997 to 2011. As well as drawing out the nuances in participants’ perspectives on the social and societal dilemmas inherent to climate change, the present study also highlights the rejoinders and resolutions proposed by people to these dilemmas. It is suggested that recognition of the ways people find to navigate these difficult issues offers some cause for optimism regarding the public’s conceptualisation of, and response to, climate change.
New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei
Authors: Sinisi Annamaria , Calcinai Barbara , Cerrano Carlo , Dien Henny A , Zampella Angela , D’Amore Claudio , Renga Barbara , Fiorucci Stefano , Taglialatela-Scafati Orazio
Published: August 2013

Chemical analysis of the organic extract of Theonella swinhoei yielded two new tridecadepsipeptides of the theonellapeptolide family, namely sulfinyltheonellapeptolide, characterized by a methylsulfinylacetyl group at the N-terminus, and theonellapeptolide If, the first member of this class of compounds to show four valine residues. The structures of the compounds, isolated along with the known theonellapeptolide Id, were determined by extensive 2D NMR and MS/MS analyses followed by application of Marfey’s method. The isolated peptides exhibited moderate antiproliferative activity against HepG2 cells, a hepatic carcinoma cell line.
Spark Plasma Sintering of MAX Phases and Their Related Composites
Authors: Jiang Wan , Zhang Jianfeng , Wang Lianjun
Published: August 2013

With the combined merits of both metals and ceramics, including good electrical and thermal conductivity, ready machinability, exceptional damage tolerance, light weight, high rigidity, etc., the ternary layered MAX compounds have attracted much attention in the world. For the synthesis and consolidation of MAX phases, the relatively novel spark plasma sintering (or SPS in short) represents a very competitive technique for its high efficiency and energy saving. Since 2000’s, SPS has been extensively used for this propose, especially in Ti3SiC2 and Ti3SiC2-based composites. The present general results indicate that Ti/Si/TiC is the most appropriate powder mixture and Al is a good aid for the synthesis of high purity Ti3SiC2 by SPS. Various Ti3SiC2-based composites have also been consolidated by SPS and the related properties were improved, such as hardness, strength, fracture toughness and conductivity. It is very important to notice that, Ti3SiC2 phase can also be in situ synthesized in its composites as the commercial Ti3SiC2 powder is hardly available. A few other MAX phases have also been synthesized and consolidated by SPS in one step using various powder mixtures. However, much work should be done to clarify the synthesis mechanism and various processing windows for MAX phases by SPS technique. Lowering the fabrication cost and finding appropriate applications of MAX phases are also eagerly expected.
Effect of Transition Metal Silicides on Microstructure and Mechanical Properties of Ultra-High Temperature Ceramics
Authors: Silvestroni Laura , Sciti Diletta
Published: August 2013

The IV and V group transition metals borides, carbides, and nitrides are widely known as ultra-high temperature ceramics (UHTCs), owing to their high melting point above 2500°C. These ceramics possess outstanding physical and engineering properties, such as high hardness and strength, low electrical resistivity and good chemical inertness which make them suitable structural materials for applications under high heat fluxes. Potential applications include aerospace manufacturing; for example sharp leading edge parts on hypersonic atmospheric re-entry vehicles, rocket nozzles, and scramjet components, where operating temperatures can exceed 3000°C. The extremely high melting point and the low self-diffusion coefficient make these ceramics very difficult to sinter to full density: temperatures above 2000°C and the application of pressure are necessary conditions. However these processing parameters lead to coarse microstructures, with mean grain size of the order of 20 µm and trapped porosity, all features which prevent the achievement of the full potential of the thermo-mechanical properties of UHTCs. Several activities have been performed in order to decrease the severity of the processing conditions of UHTCs introducing sintering additives, such as metals, nitrides, carbides or silicides. In general the addition of such secondary phases does decrease the sintering temperature, but some additives have some drawbacks, especially during use at high temperature, owing to their softening and the following loss of integrity of the material. In this chapter, composites based on borides and carbides of Zr, Hf and Ta were produced with addition of MoSi2 or TaSi2. These silicides were selected as sintering aids owing to their high melting point (>2100°C), their ductility above 1000°C and their capability to increase the oxidation resistance. The microstructure of fully dense hot pressed UHTCs containing 15 vol% of MoSi2 or TaSi2, was characterized by x-ray diffraction, scanning, and transmission electron microscopy. Based on microstructural features detected by TEM, thermodynamical calculations, and the available phase diagrams, a densification mechanism for these composites is proposed. The mechanical properties, namely hardness, fracture toughness, Young’s modulus and flexural strength at room and high temperature, were measured and compared to the properties of other ultra-high temperature ceramics produced with other sintering additives. Further, the microstructural findings were used to furnish possible explanations for the excellent high temperature performances of these composites.
Polymer-Derived Ceramics (PDCs)
Authors: Ionescu Emanuel , Mera Gabriela , Riedel Ralf
Published: August 2013

Polymer-derived ceramics (PDCs) represent a rather novel class of ceramics which can be synthesized via cross-linking and pyrolysis of suitable polymeric precursors. In the last decades, PDCs have been attaining increased attention due to their outstanding ultrahigh-temperature properties, such as stability with respect to decomposition and crystallization processes as well as resistance in oxidative and corrosive environments. Moreover, their creep resistance is excellent at temperatures far beyond 1000 °C. The properties of PDCs were shown to be strongly related to their microstructure (network topology) and phase composition, which are determined by the chemistry and molecular structure of the polymeric precursor used and by the conditions of the polymer-to-ceramic transformation. Within this chapter, synthesis approaches, the nano/microstructure, as well as the behavior of PDCs at ultrahigh temperatures and in harsh environments will be presented. The emphasis of the highlighted and discussed results will focus on the intimate relationship between the precursors (molecular structure/architecture) and the resulting PDCs (phase composition, nano/microstructure, and UHT properties).
Carbon Vacancy Ordered Non-Stoichiometric ZrC0.6
Authors: Hu Wentao , Tian Yongjun , Liu Zhongyuan
Published: August 2013

The starting nanopowders of non-stoichiometric zirconium carbide (ZrCx) were fabricated via milling Zr powders in toluene for different dwell times. The carbon content was determined to depend on the milling time and the used amount of toluene. The bulk non-stoichiometric ZrCx with different x were prepared by spark plasma sintering of the obtained ZrCx nanopowders. The microstructural features of a sintered ZrC0.6 sample were investigated via the measurements of XRD, TEM, and HRTEM. It was found that the carbon vacancies have an ordering arrangement in C sublattice, forming a Zr2C-type cubic superstructural phase with space group of Moreover, it was observed that the superstructural phase exists in nano-domains with an average size of ~30 nm owing to the ordering length in nanoscale. During the heating treatment in air, it was recognized that the diffusion of oxygen atoms is significantly facilitated through the ordered carbon vacancies. For the heating treatment at low temperature (<300°C), the oxygen atoms diffuse easily into and occupy the ordered carbon vacancies, forming the oxy-carbide of ZrC0.6O0.4 with ordered oxygen atoms. At the heating temperature higher than 350 °C an amorphous layer of ZrC0.6Oy>0.4 was identified to be formed due to the diffusion of superfluous oxygen atoms into Zr-tetrahedral centers. Inside the amorphous layer, the metastable tetragonal zirconia nanocrystals are recognized to be gradually developed.
Carbide Particle-Reinforced Tungsten Composites in Extreme Hazard Environments
Authors: Song Guiming , Wang Yujin , Zhou Yu
Published: August 2013

The ablation as well as the associated thermal shock resistance of tungsten composites reinforced by TiC and ZrC particles is investigated with an oxyacetylene equipment. 30TiC/W (30TiC stands for 30 vol. % TiC particle content in tungsten, the same below) and 40TiC/W fail to withstand the thermal shock of 2000ºC/s during heating. In contrast, 30ZrC/W and 40ZrC/W withstand the thermal shock. Additionally, ZrC/W composites exhibit better ablation resistance than TiC/W composites. The thermal stress fields of the composite at both macro-/micro-scales induced by thermal shock at the early stage of the ablation are analyzed using finite element method. The calculated results of the damage mode of the composites show that crack initiates at the disk sample peripheral zone and then propagates to the sample center, which is consistent with the experimental observation.
PSO-CGO
Authors: Lourenço Nuno , Pereira Francisco Baptista
Published: August 2013

In this paper the authors present PSO-CGO, a novel particle swarm algorithm for cluster geometry optimization. The proposed approach combines a steady-state strategy to update solutions with a structural distance measure that helps to maintain population diversity. Also, it adopts a novel rule to update particles, which applies velocity only to a subset of the variables and is therefore able to promote limited modifications in the structure of atomic clusters. Results are promising, as PSO-CGO is able to discover all putative global optima for short-ranged Morse clusters between 30 and 50 atoms. A comprehensive analysis is presented and reveals that the proposed components are essential to enhance the search effectiveness of the PSO.
Head Motion Stabilization During Quadruped Robot Locomotion
Authors: Oliveira Miguel , Santos Cristina P. , Costa Lino , Rocha Ana Maria A. C. , Ferreira Manuel
Published: August 2013

In this work, the authors propose a combined approach based on a controller architecture that is able to generate locomotion for a quadruped robot and a global optimization algorithm to generate head movement stabilization. The movement controllers are biologically inspired in the concept of Central Pattern Generators (CPGs) that are modelled based on nonlinear dynamical systems, coupled Hopf oscillators. This approach allows for explicitly specified parameters such as amplitude, offset and frequency of movement and to smoothly modulate the generated oscillations according to changes in these parameters. The overall idea is to generate head movement opposed to the one induced by locomotion, such that the head remains stabilized. Thus, in order to achieve this desired head movement, it is necessary to appropriately tune the CPG parameters. Three different global optimization algorithms search for this best set of parameters. In order to evaluate the resulting head movement, a fitness function based on the Euclidean norm is investigated. Moreover, a constraint-handling technique based on tournament selection was implemented.