32 research outputs found
A STUDY OF THE RELATIONSHIP BETWEEN CORPORATE VENTURING AND HUMAN CAPITAL WITH ABSORPTIVE CAPACITY, INNOVATION AND FINANCIAL PERFORMANCE
ABSTRACT How companies can acquire the knowledge required for creation and implication of innovation; what is the most important factor of acquiring this knowledge? And from where the required financial resources -to convert innovations into profit and tangible revenuecan be obtained? This study addresses these questions. Thus the purpose of this study is to investigate the relationship between corporate venturing (CV) and human capital to absorptive capacity (ACAP), innovation and financial performance (FP). This study is among the field research. The population includes large manufacturing firms across Khuzestan Province having been active throughout 2013. The data collection tool was a structured questionnaire and Sampling is convenience method. The research questionnaire was distributed to a sample of 331 R&D and Human resources Experts selected using simple random sampling. The collected data were analyzed using SPSS and LISREL 8.5 statistical programs. The results indicate that there is a significant relationship between corporate venturing with Absorptive capacity and innovation, but there is no significant relationship between corporate venturing with innovation. Also there is a significant relationship between human capital with Absorptive capacity, innovation and financial performance and there is a significant relationship between Absorptive capacity with innovation. Finally, the results indicate that there is a significant relationship between financial performance and innovation
A simple strategy to increase inhibitory activity of chitosan towards iron corrosion in acidic media
227-234The chitosan as a natural and inexpensive polymer is considered as an appropriate choice towards the corrosion inhibitory. Here, the corrosion and inhibition efficacy of iron sheets is examined in the H2SO4 solution and the presence of chitosan and potassium iodide as an inhibitor through gravimetry, potentiodynamic polarization, and impedance analyses. The inhibition performance is found to be enhanced by adding chitosan concentration. The experimental data demonstrate that the doping iodide ion to chitosan is efficient on the surface coverage and the inhibition performance. The introduced inhibitors are of the interface inhibitors → liquid phase → mixed type with the physical adsorption. The adsorption of iodized chitosan on the iron surface is followed Langmuir isotherm. These inhibitors, by changing the electrical double layer, increase the resistance of charge transfer. The existence of iodide in the chitosan structure improves the electron density of polymer and strengthens the interaction between inhibitor and metal
A simple strategy to increase inhibitory activity of chitosan towards iron corrosion in acidic media
The chitosan as a natural and inexpensive polymer is considered as an appropriate choice towards the corrosion inhibitory. Here, the corrosion and inhibition efficacy of iron sheets is examined in the H2SO4 solution and the presence of chitosan and potassium iodide as an inhibitor through gravimetry, potentiodynamic polarization, and impedance analyses. The inhibition performance is found to be enhanced by adding chitosan concentration. The experimental data demonstrate that the doping iodide ion to chitosan is efficient on the surface coverage and the inhibition performance. The introduced inhibitors are of the interface inhibitors → liquid phase → mixed type with the physical adsorption. The adsorption of iodized chitosan on the iron surface is followed Langmuir isotherm. These inhibitors, by changing the electrical double layer, increase the resistance of charge transfer. The existence of iodide in the chitosan structure improves the electron density of polymer and strengthens the interaction between inhibitor and metal
Radiographic Evaluation of Root Canal Fillings Accomplished by Undergraduate Dental Students
Introduction: The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. Methods and Materials: A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson’s chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen’s kappa (k) values. The level of significance was set at 0.05. Results: Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. Conclusion: The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases
Cholesterol Ester Transfer Protein Taq1B Polymorphism and Its Association with Cardiovascular Risk Factors in Patients Undergoing Angiography in Yazd, Eastern Iran: A Cross-Sectional Study
Background: Several studies assessed the relationship between the cholesterol ester transfer protein (CETP) Taq1B gene polymorphism (rs708272) with risk factors of cardiovascular diseases (CVDs). However, their findings were inconsistent. The present study investigated the relationship between CVD risk factors and the Taq1B variant in patients undergoing coronary angiography. Methods: This cross-sectional study was conducted on 476 patients aged 30-76 years old of both sexes from 2020-2021, in Yazd (Iran). The Taq1B polymorphism genotypes were evaluated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on DNA extracted from whole blood. Standard protocols were used to measure cardio-metabolic markers. To determine the association between CVDs risk factors and the rs708272 variant, binary logistic regression was used in crude and adjusted models.Results: Taq1B polymorphism genotype frequencies were 10.7% for B1B1, 72.3% for B1B2, and 17% for B2B2. There was no significant association between abnormal levels of CVDs risk factors and different genotypes of the Taq1B variant, Gensini score (P=0.64), Syntax score (P=0.79), systolic blood pressure (P=0.55), diastolic blood pressure (P=0.58), and waist circumference (P=0.79). There was no significant association between genotypes of the rs708272 variant and any abnormal serum lipid levels. After adjusting for confounders, the results remained non-significant.Conclusion: There was no significant association between CVDs risk factors and CETP rs708272 polymorphism. The relationship between CETP gene variants and CVD occurrences varied across groups, implying that more research in different regions is required. A preprint version of this manuscript is available at https://www.researchsquare.com/article/rs-2575215/v1 with doi: 10.21203/rs.3.rs-2575215/v1
Sex differences in cerebral venous sinus thrombosis after adenoviral vaccination against COVID-19
Introduction: Cerebral venous sinus thrombosis associated with vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is a severe disease with high mortality. There are few data on sex differences in CVST-VITT. The aim of our study was to investigate the differences in presentation, treatment, clinical course, complications, and outcome of CVST-VITT between women and men. Patients and methods: We used data from an ongoing international registry on CVST-VITT. VITT was diagnosed according to the Pavord criteria. We compared the characteristics of CVST-VITT in women and men. Results: Of 133 patients with possible, probable, or definite CVST-VITT, 102 (77%) were women. Women were slightly younger [median age 42 (IQR 28–54) vs 45 (28–56)], presented more often with coma (26% vs 10%) and had a lower platelet count at presentation [median (IQR) 50x109/L (28–79) vs 68 (30–125)] than men. The nadir platelet count was lower in women [median (IQR) 34 (19–62) vs 53 (20–92)]. More women received endovascular treatment than men (15% vs 6%). Rates of treatment with intravenous immunoglobulins were similar (63% vs 66%), as were new venous thromboembolic events (14% vs 14%) and major bleeding complications (30% vs 20%). Rates of good functional outcome (modified Rankin Scale 0-2, 42% vs 45%) and in-hospital death (39% vs 41%) did not differ. Discussion and conclusions: Three quarters of CVST-VITT patients in this study were women. Women were more severely affected at presentation, but clinical course and outcome did not differ between women and men. VITT-specific treatments were overall similar, but more women received endovascular treatment.</p
Sex differences in cerebral venous sinus thrombosis after adenoviral vaccination against COVID-19
Introduction: Cerebral venous sinus thrombosis associated with vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is a severe disease with high mortality. There are few data on sex differences in CVST-VITT. The aim of our study was to investigate the differences in presentation, treatment, clinical course, complications, and outcome of CVST-VITT between women and men. Patients and methods: We used data from an ongoing international registry on CVST-VITT. VITT was diagnosed according to the Pavord criteria. We compared the characteristics of CVST-VITT in women and men. Results: Of 133 patients with possible, probable, or definite CVST-VITT, 102 (77%) were women. Women were slightly younger [median age 42 (IQR 28–54) vs 45 (28–56)], presented more often with coma (26% vs 10%) and had a lower platelet count at presentation [median (IQR) 50x109/L (28–79) vs 68 (30–125)] than men. The nadir platelet count was lower in women [median (IQR) 34 (19–62) vs 53 (20–92)]. More women received endovascular treatment than men (15% vs 6%). Rates of treatment with intravenous immunoglobulins were similar (63% vs 66%), as were new venous thromboembolic events (14% vs 14%) and major bleeding complications (30% vs 20%). Rates of good functional outcome (modified Rankin Scale 0-2, 42% vs 45%) and in-hospital death (39% vs 41%) did not differ. Discussion and conclusions: Three quarters of CVST-VITT patients in this study were women. Women were more severely affected at presentation, but clinical course and outcome did not differ between women and men. VITT-specific treatments were overall similar, but more women received endovascular treatment.</p
Catalyst Behavior Analyzed via General Regression Model with the Parameters Depending on a Covariate
Presentation of anodic electrocatalyst for polymeric fuel cell: Pt nanoparticles immobilized on NdFeO3 nanocrystals and carbon nanotubes
9-22Current catalysts for the methanol oxidation in fuel cells (typically noble metals-based) are susceptible to poisoning with intermediates like CO. Hence superseded catalysts have been desirable for methanol oxidation based on incorporation of mixed oxides. The different types of nanocomposites have been prepared with Pt nanoparticles (PtNPs), functionalized CNTs, perovskite NdFeO3 nanoparticles (NdFeO3NPs) and chitosan (CH) polymer and their catalytic activity toward methanol oxidation have been investigated by the electrochemical studies. The equations of current density versus time are obtained via the fitting and simulation of experimental data. In the following, the amount of transferred charge during methanol oxidation versus time has been calculated through the lower Riemann sum of curve correspond to experimental data and the integration of mentioned equations both. A direct methanol fuel cell (DMFC) is designed, assembled and tested with the suggested PtNPs-CNTs-NdFeO3NPs-CH nanocomposites as an anodic catalyst at variety conditions. The effect of experimental factors on DMFC performances has been investigated and optimized
Presentation of anodic electrocatalyst for polymeric fuel cell: Pt nanoparticles immobilized on NdFeO3 nanocrystals and carbon nanotubes
Current catalysts for the methanol oxidation in fuel cells (typically noble metals-based) are susceptible to poisoning with intermediates like CO. Hence superseded catalysts have been desirable for methanol oxidation based on incorporation of mixed oxides. The different types of nanocomposites have been prepared with Pt nanoparticles (PtNPs), functionalized CNTs, perovskite NdFeO3 nanoparticles (NdFeO3NPs) and chitosan (CH) polymer and their catalytic activity toward methanol oxidation have been investigated by the electrochemical studies. The equations of current density versus time are obtained via the fitting and simulation of experimental data. In the following, the amount of transferred charge during methanol oxidation versus time has been calculated through the lower Riemann sum of curve correspond to experimental data and the integration of mentioned equations both. A direct methanol fuel cell (DMFC) is designed, assembled and tested with the suggested PtNPs-CNTs-NdFeO3NPs-CH nanocomposites as an anodic catalyst at variety conditions. The effect of experimental factors on DMFC performances has been investigated and optimized