Cost-effectiveness analysis of confocal scan laser ophthalmoscope (HRT II) versus GDX for diagnosing glaucoma

Purpose: The aim of this study was to assess the cost-effectiveness of confocal scan laser ophthalmoscopy (HRT II) and compare it with scanning laser polarimetry (GDx) for diagnosing glaucoma. Methods: A cost-effectiveness analysis was performed at two eye hospitals in Iran. The outcome was measured as the proportion of correctly diagnosed patients based on systematic review and Meta analysis. Costs were estimated at two hospitals that used the HRT II (Noor Hospital) and current diagnostic testing technology GDx (Farabi Hospital) from the perspective of the healthcare provider. The incremental cost-effectiveness ratio (ICER) was estimated on the base scenario. Results: Annual average costs were estimated as 12.70 USD and 13.59 USD per HRT II and GDx test in 2012, respectively. It was assumed that 80 of the maximum feasible annual tests in a work shift would be performed using HRT II and GDx and that the glaucoma-positive (Gl+) proportion would be 56 in the referred eyes; the estimated diagnostic accuracies were 0.753 and 0.737 for GDx and HRT II, respectively. The incremental cost-effectiveness ratio (ICER) was estimated at USD44.18 per additional test accuracy. In a base sensitivity sampling analysis, we considered different proportions of Gl+ patients (30-85), one or two work shifts, and efficiency rate (60-100), and found that the ICER ranged from USD29.45to USD480.26, the lower and upper values in all scenarios. Conclusion: Based on ICER, HRT II as newer diagnostic technology is cost-effective according to the World Health Organization threshold of <1 Gross Domestic Product (GDP) per capita in Iran in 2012 (USD7228). Although GDx is more accurate and costly, the average cost-effectiveness ratio shows that HRT II provided diagnostic accuracy at a lower cost than GDx. © 2015 Iranian Society of Ophthalmology

Cost-effectiveness of rotavirus vaccination for under-five children in Iran

Background: Rotavirus diarrhea is one of the most important causes of death among under-five children. Anti-rotavirus vaccination of these children may have a reducing effect on the disease. Objectives: this study is intended to contribute to health policy-makers of the country about the optimal decision and policy development in this area, by performing cost-effectiveness and cost-utility analysis on anti-rotavirus vaccination for under-5 children. Patients and Methods: A cost-effectiveness analysis was performed using a decision tree model to analyze rotavirus vaccination, which was compared with no vaccination with Iran�s ministry of health perspective in a 5-year time horizon. Epidemiological data were collected from published and unpublished sources. Four different assumptions were considered to the extent of the disease episode. To analyze costs, the costs of implementing the vaccination program were calculated with 98 coverage and the cost of USD 7 per dose. Medical and social costs of the disease were evaluated by sampling patients with rotavirus diarrhea, and sensitivity analysis was also performed for different episode rates and vaccine price per dose. Results: For the most optimistic assumption for the episode of illness (10.2 per year), the cost per DALY averted is 12,760 and 7,404 for RotaTeq and Rotarix vaccines, respectively, while assuming the episode of illness is 300, they will be equal to 2,395 and 354, respectively, which will be highly cost-effective. Number of life-years gained is equal to 3,533 years. Conclusions: Assuming that the illness episodes are 100 and 300 for Rotarix and 300 for Rota Teq, the ratio of cost per DALY averted is highly cost-effective, based on the threshold of the world health organization (< 1 GDP per capita = 4526 USD). The implementation of a national rotavirus vaccination program is suggested. © 2015, Growth & Development Research Center

Thermal Stress Analysis of Absorber Tube for a Parabolic Collector under Quasi-Steady State Condition

AbstractThe design of parabolic trough collectors is based on the concentration of solar heat flux on its absorber tube. This may be subjected to high thermal stresses which could cause deflection of the absorber tube and failure of its cover glass tube. Investigation of earlier studies on thermal gradient and thermal stresses demonstrates that so far, the issue is considered for steady state condition based on the assumption of constant solar heat flux distribution during the day hours. However, in practice, solar heat flux distribution on the receiver tube has continues changes with respect to time and deformation is basically transient. Due the low speed of sun during a day and for specific time intervals, the average solar radiation could be considered constant for thermal stress and deflection analysis. Hence, in this study, thermal gradients as well as thermal stresses in the absorber tube are numerically investigated in quasi steady condition. Due to the wide changes of solar radiation during a year, computations are performed for four specific days of Spring Equinox, Summer Solstice, Autumnal Equinox and Winter Solstice. To compute solar heat flux distribution, SolTrace software is used and three dimensional heat flux distribution is applied as an external boundary condition to calculate temperature distribution in the absorber tube. By using Von-Misses theory, maximum equivalent of total stress is computed. Maximum deflection is evaluated for various different inlet temperatures and hot oil mass flow rates in the common range of solar thermal power plants for atypical parabolic trough collector which is under construction in Shiraz, Iran

Isolation of Bacteria with Potential Plant-Promoting Traits and Optimization of Their Growth Conditions

This research aimed at investigating the isolation and identification of bacterial strains with biological nitrogen-fixing capability and phosphate, potassium, and zinc solubilization activities from a durum wheat field under two different tillage practices including 10 years of conventional tillage (CT) and no-tillage (NT) practices. Attempts were also extended to estimate their relative abundances in the soil as well as to develop accurate mathematical models in determining the effect of different temperatures, NaCl concentrations and pH on the growth, and activity of selected isolates. Twelve effective bacterial strains, including Pseudomonas, Acinetobacter, and Comamonas genera, were identified with a great potential to solubilize the insoluble forms of phosphate (from 11.1 to 115.5 mg l−1 at pH 8), potassium (from 32.2 to 35.6 mg l−1 at pH 7), and zinc (from 1.11 to 389.90 mg l−1 at pH 9) as well as to fix N2 gas (from 19.9 to 25.2 mg l−1). To our knowledge, this is the first report of the ability of Comamonas testosteroni and Acinetobacter pittii to fix nitrogen and to solubilize insoluble potassium compound, respectively. Three families, Moraxellaceae, Pseudomonadaceae, and Comamonadaceae, showed a higher percentage of abundance in the NT samples as compared to the CT, but only significant difference was observed in the relative abundance of Pseudomonadaceae (P < 0.01). These strains could be definitively recommended as inoculants to promote plant growth in the wide ranges of pH, salinity levels (with maximum growth and complete inhibition of growth from 0.67–0.92% to 3.5–9.3% NaCl, respectively), and temperatures (2.1–45.1 °C)

The effect of host structure on the selectivity and mechanism of supramolecular catalysis of Prins cyclizations.

The effect of host structure on the selectivity and mechanism of intramolecular Prins reactions is evaluated using K12Ga4L6 tetrahedral catalysts. The host structure was varied by modifying the structure of the chelating moieties and the size of the aromatic spacers. While variation in chelator substituents was generally observed to affect changes in rate but not selectivity, changing the host spacer afforded differences in efficiency and product diastereoselectivity. An extremely high number of turnovers (up to 840) was observed. Maximum rate accelerations were measured to be on the order of 105, which numbers among the largest magnitudes of transition state stabilization measured with a synthetic host-catalyst. Host/guest size effects were observed to play an important role in host-mediated enantioselectivity

Nutrient use efficiency and nutrient uptake promoting of rice by potassium solubilizing bacteria (KSB)

The current study was carried out in both pot and field conditions to investigate the effects of three KSB strains of Pantoea agglomerans, Rahnella aquatilis and Pseudomonas orientalis on nitrogen (N), phosphorous (P) and potassium (K) uptake, nutrient use efficiency parameters and nutrients remobilization in rice (Oryza sativa L. cv. Pajohesh). The experiments included 15 treatments of KSB inoculations, commercial K biofertilizer and K chemical fertilizer. The results showed that the inoculums of all three KSB strains increased the K, N and P uptake by grain and straw, especially when applied in combination with ½ K chemical fertilizer (47.5 Kg/ha) as compared to the control treatment. The highest value of available K in the soil obtained from NPK chemical fertilizer equal to 140.1 and 134.6 mg K per kg of soil in the pot and field experiments, respectively, which were significantly higher than KSB inoculations treatments. Bacterial inoculums coupled with ½ K chemical fertilizer also enhanced the nutrient use efficiency (including agronomic efficiency (AE), apparent recovery efficiency (ARE), physiological efficiency (PE), agro-physiological efficiency (APE), internal utilization efficiency (UE), partial factor productivity (PFP), partial nutrient balance (PNB)) and nutrient remobilization. The results indicated that the bioinoculation with these KSB strains isolated from soil paddy could be considered as an effective way to increase potassium, nitrogen and phosphorus uptake by rice plant and enhance their use efficiency and remobilization to grains in the flooding irrigation conditions

High prevalence of extended-spectrum β-lactamase (blaCTX-M-15) and New Delhi metallo-β-lactamase-1 (NDM-1) genes among high-level carbapenem resistance Klebsiella pneumonia: an alarm for our health system

Background: The extended-spectrum β-lactamase (ESBL) carbapenems-resistant Klebsiella isolates are considered one of the most significant challenging in the treatment of patients in hospitals. The aim of this study was to determine the prevalence of important carbapenem resistance genes ESBL subtypes and between K. pneumoniae from patients at hospital in Tehran, Iran.Methods: Fifty-four isolates of K. pneumoniae were isolated from Shariatee Hospital in Tehran from February 2013 to July 2016. Antibiotic testing was done by using the standard disk diffusion method and E-test MIC. The confirmation of carbapenemase activity was performed using an MHT and a new method called the carbapenem inactivation method test (CIM). Finally, a polymerase chain reaction (PCR) and sequencing of related genes was performed.Results: Our PCR data demonstrate that blaCTX-M group’s 40 (81.4%) genes were the most prevalent in our hospital followed by group genes blaCTX-M-3 (18.51%) and blaCTX-M-2 (20.38%). The distribution of the CTX-M group revealed that blaCTX-M-15 23 (42.6%) was the dominant subtype. The coexistence of multiple genes included blaTEM, CTX-M and blaSHV, and CTX-M The presence of blaNDM1, blaOXA-48, and blaKPC were identified in the carbapenem-resistant isolates, 22 (40.7%), 10 (18.5%), and 7 (12.9%) respectively.Conclusion: Our research showed that a CIM test for the first time in Iran is possible and has a high facility for the fast identification of carbapenem-resistant Klebsiella (CRK). We are encountered with the emergence of CTX-M, OXA-48, KPC, and NDM1 harboring CRK strains in our hospitals. Therefore, the treatment of patients infected with these isolates will be an important future concern in our clinical settings.Running Head: Resistance genes among carbapenem-resistant Klebsiella pneumoniaKeywords: New Delhi metallo-beta-lactamase-1, Klebsiella pneumoniae, Carbapenem, Extended-spectrum ß-lactamas

The financing of uncertain future investments

Purpose - This study investigates the effects of two important financing sources, debt and cash, on a firm’s investment decisions and explores the intertemporal impact of this financing on future investment volatility. Design/methodology/approach - We first report our results using ordinary least squares (OLS) estimation and then employ an instrumental variable (IV) strategy which addresses potential endogeneity that arises from future investment volatility on current capital structure and cash levels. Findings - We find i) firms with low levels of debt or high levels of cash experience higher future investment volatility, and ii) the probability of large future investment increases with high cash levels. Our findings are economically important; for example, a one-standard-deviation increase from the mean of debt ratio implies an approximate 7.8% decrease in future investment volatility; and a one-standard-deviation increase from the mean of a firm’s cash level leads to a 47% increase in the probability of a large investment in the next year. Originality/value - The findings of this study help firms understand the impact of their present financing decisions on the plausibility of their future investments. This paper contributes to the literature by making both novel and confirmatory findings. We structure our paper to include confirmatory findings for two reasons. First, we use different methods to construct investment volatility and the related investment spike. Second, and more importantly, the hypotheses are interrelated and communicate how firms plan for and execute against uncertain future investments. Growth options are ephemeral, and the hypotheses structure provides a guideline for how a firm finances future growth options