479 research outputs found
Mineralogical Marvels: Deciphering the Geological Alchemy from Stones to Wealth
This research endeavors to dissect the mineralogical intricacies governing the alchemical metamorphosis of geological substrates into economic wealth. Employing a multifaceted approach, this study scrutinizes the crystallographic and chemical underpinnings of economically consequential minerals. Crystallographically, an exploration of intricate structures elucidates the nexus between crystal lattice configurations and resultant mineral properties, instrumental in ascertaining economic worth. Concurrently, an in-depth chemical analysis discerns the elemental intricacies dictating mineral value, establishing a nexus between compositional intricacies and economic significance. The investigation extends to the geological crucible where ore formation processes and diverse geological settings are analyzed. This includes an examination of the dynamic interplay of factors engendering the concentration of economically salient minerals. Consequently, this study accentuates the geological environments fostering mineral richness and includes pertinent case studies. Furthermore, an economic trajectory is traced, covering extraction, processing methodologies, and market dynamics. This encompasses an appraisal of contemporary mining and processing technologies, along with a discerning scrutiny of the geopolitical intricacies steering global mineral markets. In conclusion, this research amalgamates its findings into a cohesive narrative, presenting a nuanced understanding of the geological genesis of mineral wealth and its implications for scientific and economic paradigms
Effect of the renal natriuretic peptide, ularitide, alone or combined with Vasopeptidase inhibitor, Omapatrilat, on experimental volume overloadinduced congestive heart failure in rats (Ularitide/ Omapatrilat in Congestive Heart Failure)
Introduction: Ularitide is a synthetic form of renally derived natriuretic peptide (NP), urodilatin. Omapatrilat (OMA) is a Vasopeptidase inhibitor (VPI), acting by dual inhibition of both angiotensin-converting enzyme (ACE) and neutral endopeptidase 24.11 (NEP), which degrades the NPs. Ularitide and OMA underwent evaluation for the management of hypertension and heart failure (HF).Aim: This study aimed to address the effect of ularitide and OMA in aortocaval fistula (ACF) – induced congestive heart failure (CHF) in rats under various conditions of compensation (of clinical severity).Experimental protocol: Volume-overload CHF was induced in male albino rats by creating an infrarenal ACF. One week after fistula induction, ACF rats were randomized to compensated (Com) and decompensated (Decom) ACF groups and each further subdivided into ACF, ularitide and OMA/ularitide treated ACF groups. Sham was used as control. All treatment protocols were started one week after infrarenal ACF induction and continued for further two weeks. Three weeks after shunt induction, all animals were underwent assessment of cardiorenal and humoral functions. Renal outcome was measured by glomerular filtration rate (GFR), fractional excretion of sodium (FNa), absolute urinary sodium excretion (UNaV), urine volume, plasma cystin C level and urinary cyclic 30, 50-guanosine monophosphate (cGMP). The humoral function was assessed by plasma renin activity (PRA), angiotensin II (Ang II), Aldosterone, and cGMP. Cardiac outcome was assessed by plasma atrial natriuretic peptide (ANP), N-terminal pro–brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) while total and relative heart, lung and liver weights were recorded.Results: Induction of AC shunt was associated with deteriorated renal and excretory functions, activation of renin angiotensin aldosterone system (RAAS), elevated ANP with renal resistance to ANP, (NT-proBNP) and (cTnT), pulmonary and systemic congestion and marked cardiac hypertrophy. These changes were exacerbated in Decom-ACF. Ularitide treatment of ACF rats was associated with natriuresis, diuresis, enhanced GFR with RAAS inhibition. This effect was evident in Com-ACF, maximized by OMA but attenuated in Decom-ACF, restored by OMA treatment. Ularitide/OMA treatment had antihypertrophic, decongestant effect with preserved renal function, resulted in a marked improvement of animals’ survival.Conclusion: OMA potentiates the cardiorenal actions of ularitide in ACF-induced Com CHF and restoring its effect in Decom ACF, by simultaneously inhibiting ACE and NEP. OMA and ularitide could provide an effective therapeutic strategy for CHF.Keywords: Congestive heart failure; Aorto-caval fistula; Ularitide; Omapatrilat; Renin-angiotensin system; Vasopeptidase inhibitio
Mucosal and Cutaneous Human Papillomavirus Infections and Cancer Biology
Papillomaviridae is a family of small non-enveloped icosahedral viruses with double-stranded circular DNA. More than 200 different human papillomaviruses (HPVs) have been listed so far. Based on epidemiological data, a subgroup of alphapapillomaviruses (alpha HPVs) was referred to as high-risk (HR) HPV types. HR HPVs are the etiological agents of anogenital cancer and a subset of head and neck cancers. The cutaneous HPV types, mainly from beta and gamma genera, are widely present on the surface of the skin in the general population. However, there is growing evidence of an etiological role of betapapillomaviruses (beta HPVs) in non-melanoma skin cancer (NMSC), together with ultraviolet (UV) radiation. Studies performed on mucosal HR HPV types, such as 16 and 18, showed that both oncoproteins E6 and E7 play a key role in cervical cancer by altering pathways involved in the host immune response to establish a persistent infection and by promoting cellular transformation. Continuous expression of E6 and E7 of mucosal HR HPV types is essential to initiate and to maintain the cellular transformation process, whereas expression of E6 and E7 of cutaneous HPV types is not required for the maintenance of the skin cancer phenotype. Beta HPV types appear to play a role in the initiation of skin carcinogenesis, by exacerbating the accumulation of UV radiation-induced DNA breaks and somatic mutations (the hit-and-run mechanism), and they would therefore act as facilitators rather than direct actors in NMSC. In this review, the natural history of HPV infection and the transforming properties of various HPV genera will be described, with a particular focus on describing the state of knowledge about the role of cutaneous HPV types in NMSC
Synthesis of Mesoporous TiO2 Template-Free and Photocatalytic Activity for Azo Dye Degradation
Nanoporous titanium dioxide was prepared by sol-gel technique. To control the surface area, pore size and pore volume of the prepared TiO2, a catalyzed hydrolysis was carried out using different concentrations of silicotungstic acid (SWA) as a template. A fixed molar ratio of H2O/Ti was used. The prepared TiO2 was calcined at 400 or 600oC. Samples were characterized by nitrogen physic-sorption, X-ray powder diffraction (XRD), selected scattered electron diffraction, Raman spectroscopic analysis, Fourier Transform spectroscopy (FTIR), Thermo gravimetric analysis (TGA), Differential scanning calorimetry (DSC), scanning and transmission electron microscopy (SEM and TEM). The photocatalytic activity of the prepared samples was evaluated by the degradation of alizarin yellow under UV light. The results showed that the crystallinity increases as the concentration of SWA decreases. The presence of SWA during the precipitation of TiO2 prevents the formation of rutile phase and suppresses the crystal growth. The results showed also that the surface area increases as the concentration of SWA decreases. The samples prepared using 0.05M SWA and calcined at 600 oC showed a higher activity. Keywords: mesoporous TiO2, photocatalytic degradation, alizarin yellow, azodye
The role of human capital in the private manufacturing sector productivity in the developing and transition economies.
This thesis principally seeks to provide empirical examination of the contribution of human capital, particularly in the form of education, to productivity at the micor level, through the lens of human capital and production theories, for a pooled sample of countries from the Middle East and North Africa (MENA), in comparison with both the Eastern Europe and Central Asia countries (ECA). This research mainly aims to establish substantive empirical evidence on the varying effects of human capital on growth, across regions. It also aims to investigate the role of human capital investment in the productivity gains, mainly through efficiency and labour productivity, in the formal private manufacturing sector, in the aforementioned regions. The thesis takes into account the variations in per capita income levels, based on the World Bank classifications of countries by income group. In addition, this research recognises and takes into account the heterogeneity which exists throughout the selected sample of countries. The main objective of evaluating the impact of human capital is to untangle the existing differences in the firms’ performance, partly on account of employing different workers with varying levels of education, with distinctive regional socio-economic changes, and different political conditions. The stochastic frontier analysis (SFA), as a fully parameterised model is used, in order to address and examine the determinants affecting production efficiencies, especially from a human capital point of view, and in the light of Vandenbussche, Aghion, and Meghir’s 2006 assumptions, on growth, distance to frontier, and composition of human capital, which remains untested in MENA and ECA at the firm-level. The SFA was applied following the approach of Caudill, Ford, and Gropper (1995) (CFG) by estimating and testing stochastic frontier production functions, assuming the presence of heteroscedasticity in the one-sided error term (inefficiency), and by following the approaches of Hadri (1999) for cross sectional data assuming the existence of heteroscedasticity in both error terms (the one-sided inefficiency term and the two-sided symmetric random noise), in order to obtain more accurate measures of technical efficiency. However, the rationale for this choice of the two different regions, is the heterogenous organisational structures, and the dissimilarities between production functions across economies in different developmental phases, which can be used as a suitable platform for analysing the distinctive effects of human capital composition on efficiency, and growth in each region in comparison with the other. In addition, the applied methodology also involves the incorporation of two matching methods consisting of a completely randomised experimental design, propensity score matching (PSM), and a fully blocked experimental design, Mahalanobis distance matching (MDM), using a cross-sectional firm level dataset, in order to examine the causal effects of formal training on productivity in MENA, and in ECA. The main conclusion of the empirical analysis suggests that highly-educated labour proxied by workers with tertiary education and those with university degree, appear to have a positive and statistically significant impact on efficiency in the two regions. Noting that the closer is the country to the frontier, the more important this level of human capital tends to be. As a country becomes closer to the frontier, it depends more on innovation and knowledge creation, which leads to the reallocation of labour from unskilled-complementary technology production activities, to skilled-prejudiced and technology-intensive activities. This result appears to confirm the association between high levels of human capital and growth, and chimes with the relevant literature about the link between human capital and growth in the developing and developed countries. It was also found that low-skilled labour component, denoted by workers who attended secondary school, seemed to have positive and statistically significant contribution to efficiency only in the less developed countries, such as MENA. This is due to the fact that the further the country is from the technological frontier, the more reliant the country becomes on imitation activities, and this seemed to corroborate the ideas posited in the literature about the sources of growth and the proximity to the world’s technological frontier. The low-skilled labour in the private manufacturing firms, in MENA, is positively associated with high levels of efficiency, and its impact appears to be significant, especially in high- technology firms. Although in the more affluent countries, such as the high-income economies in Eastern Europe, and the middle-income economies in ECA at large, the impact of secondary school workers gives the impression of being insignificant on efficiency. With respect to the intermediate-skilled labour, which is represented by the proportion of workers who have been trained in technical schools, or received on-the-job training, the maximum likelihood estimates point that their effects on efficiency have a propensity to be statistically insignificant, in MENA and ECA, in reducing the effects of inefficiency in firms’ performance. In fact, intermediate-skilled labour is found to have a positive and significant relationship with higher levels of inefficiency, especially in MENA. Put simply, it impedes efficiency improvements in the manufacturing firms, particularly, in the low and medium-technology plants in MENA. Furthermore, the effects of highly-skilled workers on efficiency were found to be positive and of a high level of significance in the low and medium-technology firms, and this is quite clear, especially, in the high-technology manufacturing firms in this region. All in all, the results of this study are in line, and compare well with the hypotheses of endogenous growth models of Lucas (1988) and Romer (1990), and with the assumptions of Benhabib and Spiegel (1994), that the economic growth is conditional on the human capital accumulation to improve efficiency and increase productivity in order to catch up with the technological frontier and shift it upward
Sol–Gel and Thermally Evaporated Nanostructured Thin ZnO Films for Photocatalytic Degradation of Trichlorophenol
In the present work, thermal evaporation and sol–gel coating techniques were applied to fabricate nanostructured thin ZnO films. The phase structure and surface morphology of the obtained films were investigated by X-ray diffractometer (XRD) and scanning electron microscope (SEM), respectively. The topography and 2D profile of the thin ZnO films prepared by both techniques were studied by optical profiler. The results revealed that the thermally evaporated thin film has a comparatively smoother surface of hexagonal wurtzite structure with grain size 12 nm and 51 m2/g. On the other hand, sol–gel films exhibited rough surface with a strong preferred orientation of 25 nm grain size and 27 m2/g surface area. Following deposition process, the obtained films were applied for the photodegradation of 2,4,6-trichlorophenol (TCP) in water in presence of UV irradiation. The concentrations of TCP and its intermediates produced in the solution during the photodegradation were determined by high performance liquid chromatography (HPLC) at defined irradiation times. Complete decay of TCP and its intermediates was observed after 60 min when the thermal evaporated photocatalyst was applied. However, by operating sol–gel catalyst, the concentration of intermediates initially increased and then remained constant with irradiation time. Although the degradation of TCP followed first-order kinetic for both catalysts, higher photocatalytic activity was exhibited by the thermally evaporated ZnO thin film in comparison with sol–gel one
Targeting heme oxygenase-1 in early diabetic nephropathy in streptozotocin-induced diabetic rats
Diabetic nephropathy (DN) is one of the most common microvascular diabetic complications. This study was designed to evaluate the possible protective effect and underlying mechanisms of HO-1 induction in streptozotocin (STZ)-induced early DN in rats. The diabetic rats were divided into three groups: STZ-diabetic, cobalt protoporphyrin (CoPP)-treated diabetic, and zinc protoporphyrin IX (ZnPP)-treated diabetic groups. Compared to the STZ-diabetic group, CoPP-induced HO-1 upregulation improved the diabetic state and renal functional parameters, suppressed the renal proinflammatory marker, NF-ÎşB, abrogated the elevated renal hydroxyprolin, and decreased the enhanced renal nicotinamide adenine dinucleotide phosphate oxidase activity with parallel reduction of urinary oxidative stress markers. On the contrary, treatment with ZnPP abrogated HO-1 levels, aggravated the diabetic condition with further increases in renal oxidative stress, fibrotic and inflammatory markers, and exacerbated renal dysfunction in diabetic animals. These findings suggest that the reduced diabetic renal injury upon HO-1 induction implicates the role of HO-1 induction as a potential treatment for DN
Beta-HPV types in patients with head and neck pathology and in healthy subjects
Background Human papillomaviruses (HPV) are a heterogeneous group of viruses classified into five genera. The beta-HPV type (beta-PV) infection is very common but mostly asymptomatic in immunocompetent individuals. However, beta-PVs play a role in Epidermodysplasia verruciformis and possibly in non-melanoma skin cancer. Head and neck cancer (HNC) is a common cancer type worldwide and high-risk alpha-PV involvement in HNC has been extensively studied but beta-PV types have rarely been the focus of such studies. Objectives To evaluate the prevalence of beta-PV types in HNC, subjects with non-malignant or potentially pre-malignant oral lesions, and healthy controls. Study design The frequency of different beta-PVs in samples from oral (n = 35) and oropharyngeal (n = 35) cancer patients, gender- and age-matched healthy controls (n = 70), and subjects with various non-malignant or potentially pre-malignant oral lesions (n = 102) was assessed by a highly sensitive, bead-based, multiplex genotyping assay. Results Overall, 54.8% of all tested samples contained at least one beta-PV type. Even though the correlation between types found in lavage and tissue specimens from cancer patients was low, there was a large statistically significant difference between oropharyngeal cancer patients and matched controls for HPV5 (P = 0.003 ; OR = 15.58) and between both oral (P = 0.026 ; OR = 5.7) and oropharyngeal cancer patients (P = 0.002 ; OR = 25.5) and controls for HPV122. In addition, there was no correlation between the prevalence of alpha and beta-PVs in the study patients. Conclusion The study provides new data on the prevalence of beta-PVs in HNC. HPV5 was found significantly associated with HNC as already observed by other studies. Additionally, the significant association of HPV122 with HNC might warrant further study as this type has not been extensively studied so fa
Complete genome sequence of a novel human gammapapillomavirus isolated from a cervical swab in Luxembourg
A novel human papillomavirus genotype was detected in a cervical swab specimen by next-generation sequencing after rolling circular amplification. It was fully cloned and characterized. The L1 open reading frame showed 77% nucleotide similarity with the closest genotype, HPV101, belonging to the gamma-6 species
- …