Effects of Surface Roughness on the Electrochemical Reduction of CO₂ over Cu

We have investigated the role of surface roughening on the CO₂ reduction reaction (CO₂RR) over Cu. The activity and product selectivity of Cu surfaces roughened by plasma pretreatment in Ar, O₂, or N₂ were compared with that of electrochemically polished Cu samples. Differences in total and product current densities, the ratio of current densities for HER (the hydrogen evolution reaction) to CO₂RR, and the ratio of current densities for C₂₊ to C₁ products depend on the electrochemically active surface and are nearly independent of plasma composition. Theoretical analysis of an electropolished and roughened Cu surface reveals a higher fraction of undercoordinated Cu sites on the roughened surface, sites that bind CO preferentially. Roughened surfaces also contain square sites similar to those on a Cu(100) surface but with neighboring step sites, which adsorb OC–COH, a precursor to C₂₊ products. These findings explain the increases in the formation of oxygenates and hydrocarbons relative to CO and the ratio of oxygenates to hydrocarbons observed with increasing surface roughness

Does body contouring after bariatric weight loss enhance quality of life? A systematic review of QOL studies

Massive weight loss following bariatric surgery can result in excess tissue, manifesting as large areas of redundant skin that can be managed by body contouring surgery. This study aims to quantify the effects of body contouring surgery on indicators of quality of life in post-bariatric patients. A systematic review and meta-analysis of the literature revealed on indices of quality of life in post-bariatric patients, before and after body contouring surgery. Body contouring surgery resulted in statistically significant improvements in physical functioning, psychological wellbeing and social functioning, as well as a reduction in BMI. Body contouring surgery offers a strategy to improve quality of life in patients suffering from the functional and psychosocial consequences of excess skin after bariatric surgery

The OmegaWhite Survey for Short-Period Variable Stars IV: Discovery of the warm DQ white dwarf OW J175358.85-310728.9

We present the discovery and follow-up observations of the second known variable warm DQ white dwarf OW J175358.85-310728.9 (OW J1753-3107). OW J1753-3107 is the brightest of any of the currently known warm or hot DQ and was discovered in the OmegaWhite Survey as exhibiting optical variations on a period of 35.5452 (2) mins, with no evidence for other periods in its light curves. This period has remained constant over the last two years and a single-period sinusoidal model provides a good fit for all follow-up light curves. The spectrum consists of a very blue continuum with strong absorption lines of neutral and ionised carbon, a broad He I 4471 A line, and possibly weaker hydrogen lines. The C I lines are Zeeman split, and indicate the presence of a strong magnetic field. Using spectral Paschen-Back model descriptions, we determine that OW J1753-3107 exhibits the following physical parameters: T_eff = 15430 K, log(g) = 9.0, log(N(C)/N(He)) = -1.2, and the mean magnetic field strength is B_z =2.1 MG. This relatively low temperature and carbon abundance (compared to the expected properties of hot DQs) is similar to that seen in the other warm DQ SDSS J1036+6522. Although OW J1753-3107 appears to be a twin of SDSS J1036+6522, it exhibits a modulation on a period slightly longer than the dominant period in SDSS J1036+6522 and has a higher carbon abundance. The source of variations is uncertain, but they are believed to originate from the rotation of the magnetic white dwarf.Comment: 11 pages, 8 figures, 7 tables. Accepted for publication by MNRA

Effects of Surface Roughness on the Electrochemical Reduction of CO₂ over Cu

We have investigated the role of surface roughening on the CO₂ reduction reaction (CO₂RR) over Cu. The activity and product selectivity of Cu surfaces roughened by plasma pretreatment in Ar, O₂, or N₂ were compared with that of electrochemically polished Cu samples. Differences in total and product current densities, the ratio of current densities for HER (the hydrogen evolution reaction) to CO₂RR, and the ratio of current densities for C₂₊ to C₁ products depend on the electrochemically active surface and are nearly independent of plasma composition. Theoretical analysis of an electropolished and roughened Cu surface reveals a higher fraction of undercoordinated Cu sites on the roughened surface, sites that bind CO preferentially. Roughened surfaces also contain square sites similar to those on a Cu(100) surface but with neighboring step sites, which adsorb OC–COH, a precursor to C₂₊ products. These findings explain the increases in the formation of oxygenates and hydrocarbons relative to CO and the ratio of oxygenates to hydrocarbons observed with increasing surface roughness

Esophageal surgery – the experience of the department of surgery of CME faculty of SUMPh “Nicolae Testemitanu”

Catedra chirurgie FECMF, USMF „Nicolae Testemiţanu”, Chişinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Esofagul, pentru chirurgi, rămâne un segment deosebit al tractului digestiv atât din cauza particularităţilor anatomo-topografice a organului, a căilor de acces către acesta, cât şi a tehnicilor operatorii asupra respectivului. Scopul lucrării: De a ne împărtăşi cu experienţa Clinicii de 30 ani în domeniul chirurgiei esofagiene. Material şi metode: Clinica de Chirurgie FECMF a USMF „Nicolae Testemiţanu” – secţia de chirurgie toracică şi chirurgie generală a Spitalului Clinic Republican îşi are direcţia cercetărilor, studiilor practico-ştiinţifice ale intervenţiilor pe esofag din 1974. Fişierul clinicii deţine mai mult de 1000 operaţii pe esofag. Rezultate: Punct de pornire au servit traumele esofagului adunând 70 cazuri. Alți 83 pacienţi – operaţi pentru diverticul, 192 cu hernii a hiatusului esofagian, 226 suferinzi de diferite forme de stenoze postcaustice, 118 pacienţi s -au operat pentru boala de reflux gastroesofagian, 115 cu achalazii, cu neoplasm esofagian s-au operat 92 pacienţi, esofag Barrett au avut 34 bolnavi, neoplasm al joncţiunii esofago-gastrice – 37 pacienţi. Avem 32 cazuri cu ruptură spontană de esofag (sindromul Boerhaave). Concluzii: Aceasta este experienţa Clinicii, în baza căreia s-a susţinut o teză de doctor habilitat şi două teze de doctor în medicină.Introduction: Esophageal surgery represents very special kind of digestive surgery, because of multiple factors – anatomical-topographic features, specific surgical access and surgical technique. Aim: To evaluate our clinical experience of 30 years of esophageal surgery. Material and methods: Since 1974, in the Department of Surgery of CME Faculty of SUMPh „Nicolae Testemitanu”, thoracic and general surgery departments of Republican Clinical Hospital, were performed about 1000 clinical cases of esophageal surgery. Results: Our first experience in esophageal surgery, as a start point was esophageal injuries – 70 patients, followed by esophageal diverticula – 83 patients, esophageal hiatus hernia – 192 treatment cases, esophageal stricture of various origin – 226 cases, 118 patients have been treated for gastro-esophageal reflux disease, 115 cases with achalasia of esophagus, 92 patients have been treated for esophageal cancer, 34 cases – with Barrett’s esophagus, gastroesophageal junction cancer – 37 cases. In addition, we have experience of 32 cases of spontaneous esophagus rupture (Boerhaave syndrome). Conclusions: The experience of the Clinic mentioned above was reflected in a thesis of doctor habilitatus of medical since and two thesis of doctor of medical since

On the construction of model Hamiltonians for adiabatic quantum computation and its application to finding low energy conformations of lattice protein models

In this report, we explore the use of a quantum optimization algorithm for obtaining low energy conformations of protein models. We discuss mappings between protein models and optimization variables, which are in turn mapped to a system of coupled quantum bits. General strategies are given for constructing Hamiltonians to be used to solve optimization problems of physical/chemical/biological interest via quantum computation by adiabatic evolution. As an example, we implement the Hamiltonian corresponding to the Hydrophobic-Polar (HP) model for protein folding. Furthermore, we present an approach to reduce the resulting Hamiltonian to two-body terms gearing towards an experimental realization.Comment: 35 pages, 8 figure

Effect of cuscuta reflexa stem and calotropis procera leaf extracts on glucose tolerance in glucose-induced hyperglycemic rats and mice

Cuscuta reflexa (whole plant) and Calotropis procera (leaves) are used in folk medicine of Bangladesh to control blood sugar in patients suffering from diabetes mellitus. The hypoglycemic effects of methanol and chloroform extracts of whole plants of Cuscuta reflexa, and methanol extract of leaves of Calotropis procera were investigated in oral glucose tolerance tests in Long Evans rats and Swiss albino mice, respectively. Both methanol and chloroform extracts of Cuscuta reflexa whole plant demonstrated significant oral hypoglycemic activity in glucose-loaded rats at doses of 50, 100 and 200 mg/kg body weight. The methanol extract of leaves of Calotropis procera, when tested at doses of 100 and 250 mg/kg body weight did not demonstrate any oral hypoglycemic effect when tested in glucose-loaded mice.Key words: Cuscuta reflexa, Calotropis procera, hypoglycemic activity, oral glucose tolerance test

Novel Plasmonic Nanocavities for Optical Trapping-Assisted Biosensing Applications

Plasmonic nanocavities have proved to confine electromagnetic fields into deep subwavelength volumes, implying their potentials for enhanced optical trapping and sensing of nanoparticles. In this review, the fundamentals and performances of various plasmonic nanocavity geometries are explored with specific emphasis on trapping and detection of small molecules and single nanoparticles. These applications capitalize on the local field intensity, which in turn depends on the size of plasmonic nanocavities. Indeed, properly designed structures provide significant local field intensity and deep trapping potential, leading to manipulation of nano-objects with low laser power. The relationship between optical trapping-induced resonance shift and potential energy of plasmonic nanocavity can be analytically expressed in terms of the intercavity field intensity. Within this framework, recent experimental works on trapping and sensing of single nanoparticles and small molecules with plasmonic nanotweezers are discussed. Furthermore, significant consideration is given to conjugation of optical tweezers with Raman spectroscopy, with the aim of developing innovative biosensors. These devices, which take the advantages of plasmonic nanocavities, will be capable of trapping and detecting nanoparticles at the single molecule level

A Photometric Redshift of z ~ 9.4 for GRB 090429B

Gamma-ray bursts (GRBs) serve as powerful probes of the early universe, with their luminous afterglows revealing the locations and physical properties of star-forming galaxies at the highest redshifts, and potentially locating first-generation (Population III) stars. Since GRB afterglows have intrinsically very simple spectra, they allow robust redshifts from low signal-to-noise spectroscopy, or photometry. Here we present a photometric redshift of z ~ 9.4 for the Swift detected GRB 090429B based on deep observations with Gemini-North, the Very Large Telescope, and the GRB Optical and Near-infrared Detector. Assuming a Small Magellanic Cloud dust law (which has been found in a majority of GRB sight lines), the 90% likelihood range for the redshift is 9.06 7. The non-detection of the host galaxy to deep limits (Y(AB) ~ 28, which would correspond roughly to 0.001L* at z = 1) in our late-time optical and infrared observations with the Hubble Space Telescope strongly supports the extreme-redshift origin of GRB 090429B, since we would expect to have detected any low-z galaxy, even if it were highly dusty. Finally, the energetics of GRB 090429B are comparable to those of other GRBs and suggest that its progenitor is not greatly different from those of lower redshift bursts

A model for magnetically coupled sympathetic eruptions

Sympathetic eruptions on the Sun have been observed for several decades, but the mechanisms by which one eruption can trigger another one remain poorly understood. We present a 3D MHD simulation that suggests two possible magnetic trigger mechanisms for sympathetic eruptions. We consider a configuration that contains two coronal flux ropes located within a pseudo-streamer and one rope located next to it. A sequence of eruptions is initiated by triggering the eruption of the flux rope next to the streamer. The expansion of the rope leads to two consecutive reconnection events, each of which triggers the eruption of a flux rope by removing a sufficient amount of overlying flux. The simulation qualitatively reproduces important aspects of the global sympathetic event on 2010 August 1 and provides a scenario for so-called twin filament eruptions. The suggested mechanisms are applicable also for sympathetic eruptions occurring in other magnetic configurations.Comment: 6 pages, 4 figures, accepted in ApJ Letter