What can we learn from ancient sales ledgers?

Victorian era customer purchase records from a London tailor reveal a close fit between actual and predicted buying using the stochastic NBD model. Within this conceptual framework, novel data generates useful results, in this case showing that the buying patterns of high-end customers in the 19th century are familiar and comparable to 21st century counterparts. This is useful in categories that lack longitudinal data, such as many luxury goods. The first contribution of this research is to show that luxury goods consumer culture is steady over time. Second, the NBD model can be used to predict market penetration growth. Third, the results indicate that marketers should seek to increase the total number of customers rather than just focus on heavy ones and finally the NBD model can serve as a benchmark tool to evaluate any real change in buying behavior (as opposed to stochastic change), caused by marketing activities

The use of beta-carotene as environmentally safe inhibitor for Cu-Al-Ni alloyscorrosion in sulfide polluted chloride solutions

The stability of Cu-Al-Ni alloys used in the manufacture of NaCl in Egypt was investigated in sulfide polluted chloride solutions. Three different alloys, namely, Cu-10Al-5Ni, Cu-10Al-10Ni and Cu-10Al-45Niwereinvestigatedinchloride containingsulfide-ions using different electrochemical techniques including polarization and electrochemical impedance spectroscopy. The presence of sulfide ions in the chloride solution accelerates thecorrosion of Cu-Al-Ni alloys,whereas the increase of the nickel content in the alloy improves its corrosion resistance.?-carotene as eco-friendly corrosion inhibitor was used to protect the Cu-10Al-Ni alloys from corrosion in presence of sulfide ions. The corrosion inhibition efficiency reached >95% at 50 ppm of ?-carotene. The alloy surface was investigated by the scanning electron microscope and the surface constituents were analyzed by EDAX. Keywords: Corrosion; chloride, Cu-Ni alloys; EIS; sulfide pollution

Stability of Some Copper Ternary Alloys in Chloride Solutions Polluted by Sulfide Ions

The electrochemical performance of three copper alloys was investigated in simulated marine solution polluted by sulfide ions. Polarization techniques and electrochemical impedance spectroscopy, EIS, were used. Surface examination and morphological studies were employed. The results showed that the Cu-10Ni-10Zn alloy is more stable than the other two alloys. The alloy surface was covered by a barrier layer protecting it from corrosion. The thickness and resistance of the barrier layer formed on the Cu-10Ni-10Zn alloy increases with the increase of the immersion time. The mechanism of the corrosion process and the barrier film formation was discussed.  A comparison was made between the electrochemical stability of the three alloys in sulfide polluted chloride solution. The incorporation of Ni in the Cu2O barrier film leads to its stabilization and the stability is enhanced by the presence of Zn. The results leads to the recommendation of the Cu-10Ni-10Zn alloy for applications in sulfide polluted marine environments. Keywords:  Copper alloys, EIS, Polarization, SEM, Passive Films

Antioxidative effects of tempol on mitochondrial dysfunction in diabetic nephropathy

Introduction. Oxidative stress has a well-known role in diabetic nephropathy, and mitochondria are the major source of reactive oxygen species production. This study aimed to assess the effect of tempol, a superoxide dismutase mimetic agent, on mitochondrial antioxidant enzymes and cell viability in diabetic nephropathy. Materials and Methods. Adult male Wistar rats were divided into 4 groups of 7 animals. Diabetes mellitus was induced by injection of streptozotocin in 2 groups, the rat in one of which were also treated with tempol for 4 weeks. Another group without diabetes mellitus received tempol, and the last group was the control. At the end of the treatment period, the kidney mitochondria were isolated and their antioxidant enzymes, including superoxide dismutase, glutathione peroxidase, and catalase were assessed. Malondialdehyde, total antioxidant capacity, and kidney cells viability were studied, as well. Results. The diabetic group was significantly different compared with the control group in malondialdehyde, catalase, and glutathione peroxidase activities. Superoxide dismutase and total antioxidative capacity did not show any significant differences among the four groups. Moreover, the diabetic group treated with tempol had significantly different glutathione peroxidase level and kidney cells viability, compared to the other diabetic group (P <.05) Conclusions. Diabetic nephropathy induces changes in mitochondrial antioxidative biomarkers and cells viability, some of which can be modified by tempol administration in rats. © 2018, Iranian Society of Nephrology. All rights reserved

Electro-optically tunable microring resonators in lithium niobate

Optical microresonators have recently attracted a growing attention in the photonics community. Their applications range from quantum electro-dynamics to sensors and filtering devices for optical telecommunication systems, where they are likely to become an essential building block. The integration of nonlinear and electro-optical properties in the resonators represents a very stimulating challenge, as it would incorporate new and more advanced functionality. Lithium niobate is an excellent candidate material, being an established choice for electro-optic and nonlinear optical applications. Here we report on the first realization of optical microring resonators in submicrometric thin films of lithium niobate. The high index contrast films are produced by an improved crystal ion slicing and bonding technique using benzocyclobutene. The rings have radius R=100 um and their transmission spectrum has been tuned using the electro-optic effect. These results open new perspectives for the use of lithium niobate in chip-scale integrated optical devices and nonlinear optical microcavities.Comment: 15 pages, 8 figure

Comparison of health-related quality of life after percutaneous coronary intervention and coronary artery bypass surgery

BACKGROUND: Health-related quality of life (HRQOL) evaluation is an important measure of the impact of the disease. As more people with coronary heart disease (CHD) live longer, doctors and researchers want to know how they manage in day to day life. It looked like adults with CHD had a decrease QOL. The aim of this study was to comparison of HRQOL of patients who underwent percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) and to assess its main determinants in the whole sample of coronary artery disease (CAD) patients. METHODS: The study was carried out to estimate HRQOL of 109 patients who underwent invasive coronary revascularization PCI (n = 75) and CABG (n = 34). We applied HRQOL after 6 months and 2 years in both groups and scores were compared. The HRQOL data were obtained using MacNew Heart Disease questionnaire with dimensions emotional, physical and social that estimated. Data entry and analysis were performed by SPSS 16.0. RESULTS: A total MacNew scale in CABG and PCI group in 6 months after treatment were 45.32 ± 13.75 and 53.52 ± 15.63, respectively (P = 0.0100). After 2 years HRQOL mean changed to 51.176 ± 14.80 and 49.55 ± 16.22, respectively, in CABG and PCI group (P = 0.4280). Our results in within-group analysis showed total MacNew scale and its subscales were changed significantly after 2 years in CABG and PCI group�s scores were detected. We found in the whole sample of CAD patients those who had a higher level of income and education and were not either overweight or obese experienced better HRQOL. CONCLUSION: Our results showed that patients who underwent PCI experienced significantly higher HRQOL in 6 months after revascularization but over 24 months follow-up no difference was observed between the two groups. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved

Aphthous ulcer and the effective factors on it's incidence among the students of Golestan Medical Sciences University in the north of Iran

The aim of this study was to determine the prevalence and probable predisposing factors of Aphthous ulcer among the medical students. This project was a cross-sectional and descriptive study, which was carried out on 485 students of Golestan University of medical sciences in the north of Iran. Data was collected by filling the questionnaire. The gathered informations entered into SPSS software and were analyzed by Chi square method. The mean age of the students was 21.8 years. 36.9% (179 persons) of subjects had positive history and 8.9% (43 persons) of them had present Aphthous ulcer at the time of interview. 70.6% of students with positive personal history of Aphthous ulcer had positive family history of Aphthous ulcer too. Internal labial mucosa was the commonest site of the lesion among the subjects with present Aphthous ulcer. We found that gender, positive family history, the field of study, the form of diet and stress had a major correlation with the incidence of Aphthous ulcer. © 2007 Asian Network for Scientific Information

Effect of gallic acid on chronic restraint stress-induced anxiety and memory loss in male BALB/c mice

Objective(s): Long-term exposure to stress leads to memory deficits and certain mood disorders such as depression and anxiety. We aimed to study the effect of gallic acid (GA) on chronic restraint stress (CRS) induced anxiety and memory deficits in male BALB/c mice. Materials and Methods: Ninety male BALB/c mice were assigned to nine groups including caged control (CC): food-water deprived (FWD), under chronic restraint stress (CRS), CRS+ gallic acid (5, 10, and 20 mg/ kg), and gallic acid (5, 10, and 20 mg/kg). Behavioral assays were performed after 21 days of daily treatment with CRS and GA. Serum and brain levels of malondialdehyde (MDA) and total antioxidant capacity (TCA) and serum corticosterone level were also measured. Results: Treatment of CRS mice with GA significantly improved passive avoidance memory in the shuttle box and ameliorated anxiety-like behaviors in the elevated plus maze (EPM) and open filed test (OFT). GA treatment significantly reduced elevated levels of serum and brain MDA and increased brain TCA. CRS and GA did not affect serum corticosterone levels. Treatment of healthy mice with GA had some adverse effects and induced some anxiety and oxidative stress. Conclusion: GA exerted protective effects against stress-induced mood and memory deficit disorders

A nano-particle based approach to improve filtration control of water based muds under high pressure high temperature conditions

There have been many attempts to improve the filtration control of water based muds under High Pressure High Temperature (HPHT) condition using a cost effective approach. Nano particles are perhaps the best option considering their successful applications reported in many studies. However, they are often expensive and pose unfavourably changes on the rheology of the muds. In this paper, an attempt was made to show the application of Nano Glass Flakes (NGFs) as a cheap but effective nano particle to control the filtration of water based muds under HPHT conditions. Performing a series of rheology, filtration and conductivity tests on the mud samples with unmodified NGFs revealed that this nano particle increases the mud rheology, yield point and gel strength of the mud with a slight impact on the filtration loss. However, by modifying the surface charges of NGFs with a cationic surfactant, filtration loss was significantly reduced without any severe impacts on the mud rheology. Considering the conductivity of the mud which increases by adding the modified NGF, this nano particle might be a good choice to improve the overall performance of water based muds under HPHT conditions