Tissue apposition system: new technology to minimize surgery for endoscopically unresectable colonic polyps.

Objective: This is the first clinical series using the Tissue Apposition System (TAS) device in a feasibility study of polypectomy as an alternative to laparoscopic colectomy (LC) for endoscopically unresectable polyps. TAS is a novel T-tag system for endoscopic placement of sutures, facilitating closure of larger defects from advanced endoluminal or transluminal endoscopic procedures. Such novel instrumentation may reduce risk and accelerate recovery.

Endoscopic mucosal resection with full-thickness closure for difficult polyps: a prospective clinical trial.

Background: Large flat polyps may be more amenable to endoscopic resection if an endoluminal method for full-thickness closure were available.

Objective: Assessment of feasibility of endoluminal full-thickness closure.

Design: Prospective, open-label, interventional study.

A novel approach for the simultaneous repair of large midline incisional and parastomal hernias with biological mesh and retrorectus reconstruction.

Introduction: Patients with concomitant large midline incisional and parastomal hernias present many unique challenges to the reconstructive surgeon.

Methods: We describe a novel approach of simultaneously repairing the midline incisional and parastomal defect, while prophylactically reinforcing the relocated stoma site with a retrorectus biological graft.

Results: During the study period, 9 men and 3 women with a mean age of 65 years, body mass index (BMI) 34 kg/m2, and American Society of Anesthesiologists score (ASA) 3.

Long-range corrected density functional theory study on static second hyperpolarizabilities of singlet diradical systems.

Within the spin-unrestricted density functional theory (DFT) the long-range correction (LC) scheme combined with the Becke-Lee-Yang-Parr exchange-correlation functional, referred to as LC-UBLYP method, has been applied to the calculation of the second hyperpolarizability (gamma) of open-shell singlet diradical systems of increasing complexity and has demonstrated good performance: (i) for the simplest H(2) dissociation model, the gamma values calculated by the LC-UBLYP method significantly overshoot the full configuration interaction result but reproduce qualitatively the evolution of gamma as a function of the diradical character, (ii) for small singlet diradical 1,3-dipole systems, the diradical character dependence of gamma determined by the UCCSD and UCCSD(T) reference methods is reproduced semiquantitatively by the LC-UBLYP method except in the small diradical character region, where the spin-unrestricted solutions coincide with spin-restricted solutions, (iii) the LC-UBLYP method also closely reproduces the UCCSD(T) results on the diradical character dependence of gamma of the p-quinodimethane model system, particularly in the intermediate and large diradical character regions, whereas it shows an abrupt change for a diradical character (y) close to 0.2 originating from the triplet instability, (iv) the reliability of LC-UBLYP to reproduce reference coupled cluster results on open-shell singlet systems with intermediate and large diradical characters has also been substantiated in the case of gamma of 1,4-bis-(imidazol-2-ylidene)-cyclohexa-2,5-diene (BI2Y), then (v), for real systems built from a pair of phenalenyl radicals separated by a conjugated linker, the LC-UBLYP results have been found to closely match the UBHandHLYP values-which, for small systems are in good agreement with those obtained using correlated molecular orbital methods-whereas the UB3LYP results can be much different. These results are not only important from the viewpoint of an efficient determination of the nonlinear optical properties of open-shell singlet systems, but also from the viewpoint of defining new challenges for elaborating improved exchange-correlation functionals.

Rectovaginal fistula.

Despite the prevalence and severe implications of rectovaginal fistula, there is no universally accepted evidence-based approach to surgical management. This article offers a disease-based review of traditional management strategies and highlights the variety of technical approaches that are currently effective for the eradication of this socially disabling condition.

Orientational analysis of dodecanethiol and p-nitrothiophenol SAMs on metals with polarisation-dependent SFG spectroscopy.

Polarisation-dependent sum frequency generation (SFG) spectroscopy is used to investigate the orientation of molecules on metallic surfaces. In particular, self-assembled monolayers (SAMs) of dodecanethiol (DDT) and of p-nitrothiophenol (p-NTP), grown on Pt and on Au, have been chosen as models to highlight the ability of combining ppp and ssp polarisations sets (representing the polarisation of the involved beams in the conventional order of SFG, Vis and IR beam) to infer orientational information at metallic interfaces. Indeed, using only the ppp set of data, as it is usually done for metallic surfaces, is not sufficient to determine the full molecular orientation.

Dyslipidemia in seven Latin American cities: CARMELA study.

Objective: The objective of this study was to describe the prevalence of dyslipidemia in the CARMELA study population.

Methods: CARMELA was a cross-sectional study of cardiovascular risk conducted between September 2003 and August 2005 in adults (aged 25 to 64 years) living in Barquisimeto (n=1,824), Bogotá (n=1,511), Buenos Aires (n=1,412), Lima (n=1,628), Mexico City (n=1,677), Quito (n=1,620), and Santiago (n=1,605). Dyslipidemia was defined as the presence of one or more of the following conditions: triglycerides>/=200 mg/dL, or total cholesterol (TC)>/=240 mg/dL, or HDL cholesterol<40 mg/dL, or LDL cholesterol=not optimal, or currently taking antilipemic agents.

Investigation of the resonance Raman spectra and excitation profiles of a monometallic ruthenium(II) [Ru(bpy)2(HAT)]2+ complex by time-dependent density functional theory.

The resonance Raman (RR) properties of the [Ru(bpy)(2)(HAT)](2+) (where bpy = 2,2'-bipyridine and HAT = 1,4,5,8,9,12-hexaazatriphenylene) complex have been investigated by means of time-dependent density functional theory calculations employing the hybrid B3LYP-35 XC functional and by including the effects of the solvent within the polarizable continuum model approach. Analysis of the electronic excited-state energies has demonstrated that mainly four different metal-to-ligand charge-transfer excitations contribute to the first absorption band in vacuo and water. The simulation of the absorption spectra by including the vibronic structure of the states has shown a general agreement with the experimental spectrum recorded in water.

Hypertension in seven Latin American cities: the Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) study.

Background: Little information is available regarding hypertension, treatment, and control in urban population of Latin America.

Objective: We aimed to compare blood pressure (BP) distribution, hypertension prevalence, treatment, and control in seven Latin American cities following standard methodology.

Methods: The Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) study was a cross-sectional, epidemiologic study assessing cardiovascular risk factors using stratified multistage sampling of adult populations (aged 25-64 years) in seven cities: Barquisimeto (Venezuela; n = 1848); Bogotá (n = 1553); Buenos Aires (n = 1482); Lima (n = 1652); Mexico City (n = 1720); Quito (n = 1638); and Santiago (n = 1655).

Prevalence of the metabolic syndrome in Latin America and its association with sub-clinical carotid atherosclerosis: the CARMELA cross sectional study.

Background: Metabolic syndrome increases cardiovascular risk. Limited information on its prevalence in Latin America is available. The Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) study included assessment of metabolic syndrome in 7 urban Latin American populations.

Remarkable two-photon absorption in open-shell singlet systems.

Remarkable enhancement of two-photon absorption (TPA) peak is theoretically predicted in symmetric open-shell singlet diradical systems with intermediate diradical character as compared to closed-shell and pure diradical systems. It is revealed that the largest TPA peak intensities occur for open-shell singlet diradicals having a ferromagnetically coupled ground state and strongly depend on the ratio between damping factors of the excited states. This result confirms that open-shell singlet conjugated molecules with intermediate diradical characters have precedence over conventional closed-shell conjugated systems in resonant third-order nonlinear optical properties.

Acute management of stoma-related colocutaneous fistula by temporary placement of a self-expanding plastic stent.

Colocutaneous fistulas are frequently the result of complications related to previous operative procedures and are a major cause of morbidity. Most are initially treated conservatively, with a large percentage eventually requiring further surgery for definitive treatment. The use of a temporary colonic stent for the management of colostomy-related colocutaneous fistula has not been previously described.

High prevalence of diabetes and impaired fasting glucose in urban Latin America: the CARMELA Study.

Aims: Cardiovascular risk is increased with glucose metabolism abnormalities. Prevalence data can support public health initiatives required to address this risk. The Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) study was designed to estimate the prevalence of Type 2 diabetes, impaired fasting glucose and related risk factors in seven urban Latin American populations.

Conformation-controlled networking of H-bonded assemblies on surfaces.

A temperature-induced phase transition of a 2D H-bonded assembly, enabling quadruple H-bonding interactions, from a hexagonal porous network into a close-packed rhombic arrangement has been observed on Ag(111) by STM imaging.

Theoretical simulation of vibrational sum-frequency generation spectra from density functional theory: application to p-nitrothiophenol and 2,4-dinitroaniline.

The molecular orientation of adsorbed molecules forming self-assembled monolayers can be determined by combining vibrational sum-frequency generation (SFG) measurements with quantum chemical calculations. Herein, we present a theoretical methodology used to simulate the SFG spectra for different combinations of polarizations. These simulations are based on calculations of the IR vectors and Raman tensors, which are obtained from density functional theory computations.

Effect of the dynamical disorder on the second-order nonlinear optical responses of helicity-encoded polymer strands.

By combining classical samplings with quantum chemistry semiempirical time-dependent Hartree-Fock calculations, the high impact of dynamic fluctuations on the NLO properties of helical strands has been evidenced. In particular, these fluctuations are responsible for relative variations of approximately 20% in the hyper-Rayleigh responses in both pyridine-pyrimidine (py-pym) and hydrazone-pyrimidine (hy-pym) strands. Then, dynamical disorder has an even more important impact on the electric-field-induced second harmonic generation responses, whose variations can reach 2 (py-pym) or 5 (hy-pym) times their mean value.

Electrostatic interaction schemes for evaluating the polarizability of silicon clusters.

Electrostatic interaction schemes have been applied to predict the evolution of the polarizability in Si(n) clusters of increasing size (n=3-19). Both on-site polarization and charge transfer effects have been included in the interaction scheme, of which the values have been compared to B3LYP/6-311G(*) and other first principles results. To reproduce the pattern of the variation of the B3LYP average polarizability per Si atom as a function of the cluster size, the atomic polarizability employed in the interaction scheme should amount to roughly 80% of the bulk atomic polarizability.

Laparoscopic rectal resections and fast-track surgery: what can be expected?

Background: We present the results of combining protocols of standardized laparoscopic rectal resection (LRR) and perioperative fast track care.

Methods: Patients undergoing LRRs were identified from a prospectively maintained, institutional review board-approved database. Perioperative fast track care and laparoscopic operations were performed according to a standardized system.

Validation of a novel postoperative quality-of-life scoring system.

Background: No specific scoring system exists for the assessment of postoperative quality of life (QOL) after major abdominal surgery. This study prospectively validates PQL, a novel prospective scoring system in patients having laparoscopic or open major abdominal colorectal surgery.

Methods: Six experienced surgeons developed the questionnaire.

Emergency laparoscopic colectomy: does it measure up to open?

Background: Laparoscopic colectomy has become the standard of care for elective resections; however, there are few data regarding laparoscopy in the emergency setting.

Methods: By using a database with prospectively collected data, we identified 94 patients who underwent an emergency colectomy between August 2005 and July 2008. Laparoscopic surgeries were performed in 42 patients and were compared with 25 patients who were suitable for laparoscopy but received open colectomy.

Two-way molecular switches with large nonlinear optical contrast.

Molecular switches: Highly efficient acido- and photoswitchable frequency doublers (see scheme) based on the indolinooxazolidine core are studied by means of hyper-Rayleigh experiments and quantum-chemical calculations.To optimize the nonlinear optical (NLO) contrast, a series of indolinooxazolidine derivatives with electron-withdrawing substituents in the para position on the indolinic residue have been synthesized. Their linear and nonlinear optical properties have been characterized by UV-visible absorption and hyper-Rayleigh scattering measurements, as well as by ab initio calculations.

The feasibility of laparoscopic colectomy in urgent and emergent settings.

Background: Laparoscopic colectomy (LC) is slowly becoming the standard of care for elective resections. However, the use of LC in the emergency setting is relatively unstudied. The authors describe their experience with a series of emergent and urgent LC cases for a variety of colorectal pathologies.

Prediction of Vibronic Coupling and Absorption Spectra of Dimers from Time-Dependent Density Functional Theory: The Case of a Stacked Streptocyanine.

Methods based on density functional theory calculations have been used to simulate the absorption spectra of a streptocyanine and of its covalently bonded dimer. Two approaches, based on multimode Franck-Condon overlap integrals, have been employed. In the first approach the monomer and the dimer are treated as single molecules, and the Franck-Condon factors are determined for both systems.

Vibrational Raman optical activity of pi-conjugated helical systems: hexahelicene and heterohelicenes.

Helicenes constitute a special class of molecules combining helical conformation with pi-electron delocalization. These confer to helicenes specific chirooptical properties. In this article, we investigate the vibrational signatures thanks to the simulation of vibrational Raman optical activity (VROA) spectra.