Enhancement of the Binding Energy of Charged Excitons in Disordered Quantum Wires

Negatively and positively charged excitons are identified in the spatially-resolved photoluminescence spectra of quantum wires. We demonstrate that charged excitons are weakly localized in disordered quantum wires. As a consequence, the enhancement of the "binding energy" of a charged exciton is caused, for a significant part, by the recoil energy transferred to the remaining charged carrier during its radiative recombination. We discover that the Coulomb correlation energy is not the sole origin of the "binding energy", in contrast to charged excitons confined in quantum dots.Comment: 4 Fig

Folate intake and risk of oral and pharyngeal cancer

Background: Diet has been recognised as having a role in the aetiology of oral and pharyngeal cancer, and dietary factors may account for 10-15% of cases in Europe. Folate deficiency has been linked to risk of several cancers, but has not been studied adequately with respect to oral cancer. Patients and methods: This case-control study, conducted in Italy and French-speaking Switzerland, included 749 patients with incident cancer of the oral cavity and pharynx, and 1772 hospital controls with acute, non-neoplastic conditions. The interviews used a validated food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using multiple logistic regression. Results: The ORs were 0.68 (95% CI 0.52-0.88) for the intermediate tertile and 0.53 (95% CI 0.40-0.69) for the highest tertile of dietary folate intake, compared with the lowest tertile. No heterogeneity was found in strata of gender, age, methionine intake or alcohol consumption. The combined OR for low-folate and high-alcohol intake versus high-folate and low-alcohol intake was 22.3 (95% CI 13.1-38). Conclusions: Our study supports a protective role of folate against oral and pharyngeal carcinogenesis. Compared with low folate intake, a consistent reduction in risk was already observed from intermediate levels of intake, suggesting that cancer risk may be related to relative folate deficienc

ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI PRODUKSI IKAN BANDENG DI KOTA BANDA ACEH

ABSTRAKPenelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi produksi ikan bandeng di Kota Banda Aceh. Penelitian ini dilakukan menggunakan metode survey dan pengambilan sampelnya dengan teknik sampel acak sederhana Simple Random Sampling.Lokasi penelitian dilakukan di Kota Banda Aceh, yaitu Kecamatan Syiah Kuala, Meuraxa, Kuta Alam, dan Kuta Raja. Waktu Penelitian dilaksanakan pada bulan Oktober 2013 sampai dengan Juli 2014. Model yang digunakan dalam penelitian ini adalah menggunakan model analisis kuantitatif untuk mengetahui Faktor-faktor yang mempengaruhi produksi ikan bandeng di Kota Banda Aceh yaitu tenaga kerja, luas tambak, jumlah nener, dan penggunaan pupuk..Untuk menguji hubungan antara variabel faktor-faktor yang mempengaruhi produksi ikan bandeng di Kota Banda Aceh, digunakan uji statistik dengan menggunakan uji T, F, dan R2.Hasil penelitian ini dapat disimpulkan bahwa secara serempak faktor , tenaga kerja, luas tambak, jumlah nener, dan jumlah pupuk berpengaruh nyata terhadap produksi ikan bandeng di Kota Banda Aceh. Secara parsial faktor jumlah nener berpengaruh nyata terhadap produksi ikan bandeng di Kota Banda Aceh. Sedangkan faktor tenaga kerja, luas tambak dan jumlah pupuk tidak berpengaruh nyata terhadap produksi ikan bandeng di Kota Banda Aceh.Kata Kunci: Ikan bandeng, analisis produksiABSTRACTThis research aims to determine the factors that affect fish production in the city of Banda Aceh. This research was conducted using a survey method and sampling with simple random sampling techniques.Location of the research conducted in the city of Banda Aceh , the District Syiah KuaLa, Meuraxa, Kuta Alam, and Kuta Raja. Time research conducted in October 2013 to July 2014 model used in this research was to use quantitative analysis model to determine the factors that affect milkfish production in Banda Aceh, namely labor, large farms, the amount of milkfish, and use of fertilizers.For Examine the relationship between the variable factors that affect milkfish production in Banda Aceh, used statistical tests using T test, F, and R2.The results of this research it can be concluded that the factors simultaneously, labor, large ponds, milkfish amount, and the amount of fertilizer significantly affect milkfish production in the city of Banda Aceh. Partially factors significantly affect the amount of milkfish fry production of milkfish in Banda Aceh. While the labor factor, vast farms and the amount of fertilizer had no significant effect on the production of milkfish in Banda Aceh .Keywords: Milkfish, production analysisBanda Ace

Folate intake and squamous-cell carcinoma of the oesophagus in Italian and Swiss men

Background: Dietary folate has been inversely related to the risk of several cancers. However, studies on the role of dietary folate in oesophageal cancer are scanty. Patients and methods: Using data from a multicentric case-control study conducted in Italy and Switzerland between 1992 and 1999, we investigated the association between dietary folate intake and oesophageal squamous-cell carcinoma (OSCC) among 351 men with incident, histologically confirmed OSCC and 875 hospital controls admitted for acute, non-neoplastic conditions, unrelated to alcohol and smoking consumption. Intake of folate and other nutrients was computed from a validated food frequency questionnaire. Results: The multivariate odds ratios (ORs) of OSCC were 0.68 (95% confidence intervals, CI: 0.46-1.00) for the highest versus the lowest tertile of folate intake, and 0.84 (95% CI: 0.72-0.99) for an increment of folate intake equal to a standard deviation (98 μg/day). The inverse relation was somewhat stronger in strata of high methionine, vitamin B6 and alcohol intake, and did not vary substantially according to age and smoking habits. Conclusion: Dietary folate was inversely related to OSCC risk in this population with high alcohol consumption and infrequent use of supplements and multivitamin

Fried foods, olive oil and colorectal cancer

Background: The epidemiologic evidence for an etiologic role of fried foods and heterocyclic amines in colorectal carcinogenesis is inconsistent. Patients and methods: We have investigated the relation between fried foods and colorectal cancer risk using data from a large, multicentric case-control study conducted in Italy and Switzerland between 1992 and 2000, with 1394 cases of colon cancer, 886 cases of rectal cancer and 4765 controls. Results: After allowing for major relevant covariates, the multivariate odds ratios (ORs) for an increment of one portion per week of fried foods were 0.97 [95% confidence interval (CI) = 0.93-1.01] for colon cancer and 1.04 (95% CI = 1.00-1.09) for rectal cancer. When we analyzed the type of fats mainly used for frying, we found that olive oil, but not other types of oils, appeared to protect from colon cancer risk (OR = 0.89, 95% CI = 0.82-0.98). Conclusions: Our results do not indicate a relevant role of fried foods on colorectal cancer risk. We found a possible favorable effect of (fried) olive oil on colon cancer risk but not on rectal cancer ris

Fibre intake and laryngeal cancer risk

Background: Consumption of vegetables, fruit and whole grain cereals has been inversely related to laryngeal cancer risk. Among the potential protective agents found in these foods, information on dietary fibres and laryngeal cancer risk are scanty. Patients and methods: A multi-centric, hospital-based case-control study was conducted on 527 patients with squamous-cell carcinoma of the larynx and 1297 non-neoplastic controls. Cases and controls, frequency matched by age, sex and study centre, were interviewed using a validated food frequency questionnaire. Results: Compared with the lowest quintile of fibre intake, the odds ratios (ORs) for the highest quintile were 0.3 [95% confidence interval (CI) 0.2-0.4] for total fibre, 0.3 (95% CI 0.2-0.5) for soluble non-cellulose polysaccharides (NCP) and for total insoluble fibre, including cellulose (OR = 0.3, 95% CI 0.2-0.4) and insoluble NCP (OR = 0.4, 95% CI 0.3-0.7). The ORs were 0.2 (95% CI 0.1-0.4) for fibre from vegetables, 0.5 (95% CI 0.3-0.7) from fruit and 1.1 (95% CI 0.6-1.9) from grains. The inverse association observed was similar among different subsites of laryngeal cancer, and consistent across strata of various covariates. Conclusions: This study found a strong inverse association between fibre intake and laryngeal cancer risk, which points to fibre as one of the beneficial components of vegetables and frui

Dietary folates and cancer risk in a network of case-control studies

Background Folate deficiency leads to DNA damage and inadequate repair, caused by a decreased synthesis of thymidylate and purines. We analyzed the relationship between dietary folate intake and the risk of several cancers. Patients and methods The study is based on a network of case-control studies conducted in Italy and Switzerland in 1991-2009. The odds ratios (ORs) for dietary folate intake were estimated by multiple logistic regression models, adjusted for major identified confounding factors. Results For a few cancer sites, we found a significant inverse relation, with ORs for an increment of 100μg/day of dietary folate of 0.65 for oropharyngeal (1467 cases), 0.58 for esophageal (505 cases), 0.83 for colorectal (2390 cases), 0.72 for pancreatic (326 cases), 0.67 for laryngeal (851 cases) and 0.87 for breast (3034 cases) cancers. The risk estimates were below unity, although not significantly, for cancers of the endometrium (OR=0.87, 454 cases), ovary (OR=0.86, 1031 cases), prostate (OR=0.91, 1468 cases) and kidney (OR=0.88, 767 cases), and was 1.00 for stomach cancer (230 cases). No material heterogeneity was found in strata of sex, age, smoking and alcohol drinking. Conclusions Our data support a real inverse association of dietary folate intake with the risk of several common cancer

Integrating the Benefits of Turquoise Hydrogen to Decarbonise High-Emission Industry

Total indirect greenhouse gas (GHG) emissions from oil and gas operations today are around 5,200 Mt of carbon dioxide equivalent (CO2-eq) yearly, 15% of total energy sector GHG emissions. Most of these emissions occur due to natural gas leaks. Methane, a much more potent GHG than CO2, is the most significant single component of natural gas and, therefore, of these emissions. Part of these emissions results from routine operations such as flaring and venting, representing both an economic and an environmental issue. Many solutions have been developed to recover and use this natural gas instead of venting and flaring it. Three possibilities were simulated with AVEVA PRO/II, and a preliminary economic assessment was carried out with Guthrie's method. 30 kmol/hr of natural gas fed was assumed, according to average site data, therefore, small-scale plants are suitable. A first solution based on compression, though requiring high OPEX (> 280 k$/y), produces very low emissions yearly (1,140 t CO2-eq/y). Another possibility is to couple flaring to a microturbine for energy generation, but this solution is both uneconomical and has a high environmental impact (> 10,000 t CO2-eq/y). The last technology analysed is thermal methane pyrolysis. This possibility, often disregarded in environmental studies, involves the production of turquoise hydrogen and carbon black. Although characterised by high capital costs (almost 3 M$), it can reduce gaseous emissions since it stores the carbon part of hydrocarbons in the solid matrix that is formed

Combining Metadynamics and Mean Force Integration for studying chemical reactions in solution: an application to backbiting of poly-Butyl Acrylate.

Free radical polymerization (FRP) and pyrolysis processes are fundamental technologies with wide-ranging applications in fields such as material synthesis and recycling. Understanding the underlying reaction mechanisms and considering the effect of solvents is crucial for the design and scale-up of such processes. However, since pyrolysis lacks selectivity and radical intermediates are hard to measure due to their extremely short lifetimes, rate coefficients from experimental campaigns on this subject are scarce. Nevertheless, experiments on free radical polymerization have been a flourishing field of study in past two decades. Knowledge of rate parameters of elementary reactions in solution or in bulk is key for formulating a valid kinetic mechanism. To this day, individual kinetic rate parameters of radical chain propagations, depropagations as well as isomerizations (backbiting) can be accessed experimentally through Pulsed Laser Polymerization technique (PLP) coupled with Size Exclusion Cromatography (SEC) [1] as well as semibatch solution polymerization coupled with Nuclear Magnetic Resonance (NMR) [2]. The resulting rate coefficients are gathered in the IUPAC Database for standard monomers which represents the gold standard for the validation of theoretical calculations. In particular, the experimental studies taken as reference [1-2] report the propagation, backbiting and beta-scission rate coefficients for poly-Butyl Acrylate in bulk and in solvent (mainly a mixture of ortho/meta/para-xylene). In this work, accelerated molecular dynamics in conjunction with Mean Force Integration (MFI) have been employed for exploring the free energy landscape of the backbiting of poly-Butyl Acrylate (PBA) in gas phase as well as in solution with non-polar (o-/m-/p-xylene) and polar (water) solvent