Ferromagnetism in Li doped ZnO nanoparticles: The role of interstitial Li

ZnO nanoparticles doped with Li (Zn1−yLiyO, y ≤ 0.1) have been investigated with emphasis on the correlation between their magnetic, electronic, and structural properties. In particular, defects such as interstitial Li and Zn atoms, substitutional Li atoms, and oxygen vacancies have been identified by X-ray photoelectron spectroscopy(XPS) and their respective roles in stabilization of the magnetic moment are discussed. X-ray diffraction(XRD) and XPS give clear evidence of Li presence at both substitutional and interstitial sites. XPS studies further show that the amount of substitutional Li defects (Lizn) and interstitial Li defects (Lii) vary non-monotonically with the Li concentration, with the Lii defects being noticeably high for the y = 0.02, 0.08, and 0.10 concentrations, in agreement with the XRD results. Magnetization studies show room temperature ferromagnetism in these nanoparticles with the moment being largest for the particles with high concentration of interstitial lithium and vice versa. Both interstitialZn(Zni) defects and Zn-O bonds were determined from the Zn LMM Auger peaks; however, the variation of these with Li concentrations was not large. Oxygen vacancies (Vo) concentrations are estimated to be relatively constant over the entire Li concentration range. We relate the Lii and Zni defects to the formation and stabilization of Znvacancies and thus stabilizing the p-type ferromagnetism predicted for cation (zinc)vacancy in the ZnO type oxides

Formulation pre-screening of inhalation powders using computational atom-atom systematic search method

This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.The synthonic modeling approach provides a molecule-centered understanding of the surface properties of crystals. It has been applied extensively to understand crystallization processes. This study aimed to investigate the functional relevance of synthonic modeling to the formulation of inhalation powders by assessing cohesivity of three active pharmaceutical ingredients (APIs, fluticasone propionate (FP), budesonide (Bud), and salbutamol base (SB)) and the commonly used excipient, α-lactose monohydrate (LMH). It is found that FP (-11.5 kcal/mol) has a higher cohesive strength than Bud (-9.9 kcal/mol) or SB (-7.8 kcal/mol). The prediction correlated directly to cohesive strength measurements using laser diffraction, where the airflow pressure required for complete dispersion (CPP) was 3.5, 2.0, and 1.0 bar for FP, Bud, and SB, respectively. The highest cohesive strength was predicted for LMH (-15.9 kcal/mol), which did not correlate with the CPP value of 2.0 bar (i.e., ranking lower than FP). High FP-LMH adhesive forces (-11.7 kcal/mol) were predicted. However, aerosolization studies revealed that the FP-LMH blends consisted of agglomerated FP particles with a large median diameter (∼4-5 μm) that were not disrupted by LMH. Modeling of the crystal and surface chemistry of LMH identified high electrostatic and H-bond components of its cohesive energy due to the presence of water and hydroxyl groups in lactose, unlike the APIs. A direct comparison of the predicted and measured cohesive balance of LMH with APIs will require a more in-depth understanding of highly hydrogen-bonded systems with respect to the synthonic engineering modeling tool, as well as the influence of agglomerate structure on surface-surface contact geometry. Overall, this research has demonstrated the possible application and relevance of synthonic engineering tools for rapid pre-screening in drug formulation and design.Peer reviewe

Relationship among plasma adipokines, insulin and androgens level as well as biochemical glycemic and lipidemic markers with incidence of PCOS in women with normal BMI

Polycystic ovary syndrome (PCOS) is an endocrine disorder in women. Omentin-1 and vaspin are secretary adipokines that are produced by the visceral adipose tissue. These levels change in obese women with PCOS. The aim of this study is to investigate whether omentin and vaspin levels change in nonobese PCOS subjects. This study is a cross-sectional case control study in which 39 women with PCOS were picked out for this study. The inclusion criteria were based on the Rotterdam 2003 diagnostic criteria. The control group consisted of 39 women with normal pelvic sonographic reports having regular menstruation and showing no signs of infertility. The fasting plasma glucose (FPG), triglyceride (TG), Chol, and high-density lipoprotein cholesterol (HDL-C), insulin, testosterone, omentin and vaspin were measured by the enzymatic methods. The differences within these groups were calculated by the un-paired t-test and the Mann–Whitney test. The results from this study show a significant increase in the amount of insulin, testosterone, homeostasis model assessments for insulin resistance, TG and lower HDL in the patient group. No significant differences were seen in omentin, vaspin, FPG, Cho, low-density lipoprotein, very low-density lipoprotein cholesterol, blood urea nitrogen, Cr and homeostasis model assessments for B cell function levels between groups. Results show that PCOS is not a determinant of decreased omentin and vaspin plasma levels and those high androgen level and insulin resistances are warning signs of PCOS

Predicting Corporate Bankruptcy in Pakistan A Comparative Study of Multiple Discriminant Analysis (MDA) and Logistic Regression

Purpose:- The aim of the study was to predict corporate bankruptcy in an emerging market like Pakistan by employing two statistical methods which are Discriminant Analysis (MDA) and Logistic Regression (Logit). It was also aimed at identifying the predicting accuracies of these statistical methods. Methodology:- This study had examined 35 bankrupt and 35 non-bankrupt companies which belongs to sector (non-financial) of Pakistan listed at KSE (Karachi Stock Exchange) over the period of seventeen years i.e. 1996 to 2012. Here, we had compared the accuracy and predictive ability of two statistical methods which are Discriminant Analysis (MDA) and Logistic Regression (Logit) and was expecting that Logistic Regression (Logit) accuracy and predictive ability will supercede Multiple Discriminant Analysis (MDA) accuracy and predictive ability. Findings:- The results have proved that Logistic Regression accuracy and predictive ability (80%) is better than the accuracy and predictive ability (78.6%) of Multiple Discriminant Analysis (MDA). It is proved that both the models identified the same amount of predictors for bankruptcy prediction. The variables identified by Logistic Regression are Shareholder’s Equity / Debt (Book Value), EBIT / Current Liabilities, Retained Earnings / Total Assets and variables identified by Multiple Discriminant Analysis (MDA) are EBIT / Current Liabilities, Sales / Total Assets and Sales / Quick Assets which have shown significant contribution towards bankruptcy prediction. Originality/Value:-This paper had revealed the accuracy and predictive ability of two statistical methods which are Discriminant Analysis (MDA) and Logistic Regression (Logit) employed in this study and has shown us the better model i.e. Logistic Regression which needs to be used in future for prediction of corporate bankruptcy in Pakistan. Limitations:- This study had used the small sample size and the focus was at Non-Financial Sector only. So it may be extended to other sectors and to other developing countries of the world. Practical Implications:- This study will be beneficial for managers and investors

RECONCILING ENERGY COST WITH A COMFORTABLE INDOOR CLIMATE: A PRACTICE-ORIENTED DESIGN PERSPECTIVE

This paper argues that comfort is a social practice, rather than a stable condition caused by controllable indoor climate parameters. It is based on ethnographic field research in different types of Danish dwelling, which brought to light six comfort practices formulated to inspire the design and engineering of indoor climates and environments. The concept of comfort practices is of major importance when the goal is to change private energy consumption patterns towards a sustainable future. This investigation extends the existing body of research about the relation between comfortable indoor climate conditions and human health, productivity and energy costs with a practice-oriented approach to understanding what indoor climate and comfort means to people in their everyday lives