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Here, we present a heuristic mechanism for efficient intersystem crossing (ISC) between singlet and triplet states with low spin-orbit coupling (SOC) in molecules having donor-acceptor (D-A) moieties separated by a sigma bond. We show that SOC between the first singlet and the higher-lying triplet states, together with nuclear motion-driven coupling of this triplet state with lower-lying triplet state during the free rotation about a sigma bond is the only plausible way to achieve the experimentally observed ISC rate for a class of D-A type photoredox catalysts. We found this mechanism to be the dominant contributor to the ISC process with the corresponding rate reaching maximum at an optimal dihedral angle between D-A moieties. An extension to this is provided by finding the same mechanism to be operative in a specific spirobis[anthracene]diones molecule where the D and A moieties are interlocked near to the optimal dihedral angle, indicating the universality of the proposed mechanism. The present findings pave the routes for the synthesis of a new generation of triplet-harvesting organic molecules.

We report on a computational study of resonant inelastic X-ray scattering (RIXS), at different fluorine K-edge resonances of the SF6 molecule, and corresponding non-resonant X-ray emission. Previously measured polarization dependence in RIXS is reproduced and traced back to the local σ and π symmetry of the orbitals and corresponding states involved in the RIXS process. Also electron-hole coupling energies are calculated and related to experimentally observed spectator shifts. The role of dissociative S-F bond dynamics is explored to model detuning of RIXS spectra at the | F1s(−1)6a1g(1) 〉 resonance, which shows challenges to accurately reproduce the required steepness for core-excited potential energy surface. We show that the RIXS spectra can only be properly described by considering breaking of the global inversion symmetry of the electronic wave function and core-hole localization, induced by vibronic coupling. Due to the localization of the core-hole we have symmetry forbidden transitions, which lead to additional resonances and the width of the RIXS profile.

Bariatric surgery is the most effective treatment for obesity; however, its utilization in older patients remains low. There is a dearth of literature on long-term effectiveness and safety of bariatric surgery in septuagenarian patients. The aim of this study was to compare the short- and long-term outcomes of bariatric surgery in this population. Patients who underwent primary laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) at our institution between 2011 and 2015 were included. Patients were divided into two age groups

The chemistry of the brown-ring test has been investigated for nearly a century. Though recent studies have focused on solid state structure determination and measurement of spectra, mechanistic details and kinetics, the aspects of solution structure and dynamics remain unknown. We have studied structural fluctuations of the brown-ring complex in aqueous solution with ab-initio molecular dynamics simulations, from which we identified that the classically established pseudo-octahedral [Fe(H

Chylous ascites is often reported in cases with lymphatic obstruction or after lymphatic injuries such as intraabdominal malignancies or lymphadenectomies. However, chylous ascites is also frequently encountered in operations for internal hernias. We sought to characterize the frequency and conditions when chylous ascites is encountered in general surgery patients. Data from patients who underwent operations for CPT codes related to open and laparoscopic abdominal and gastrointestinal surgery in our tertiary hospital from 2010 to 2019 were reviewed. Patients with the postoperative diagnosis of internal hernia were identified and categorized into three groups: Internal Hernia with chylous ascites, non-chylous ascites, and no ascites. Demographics, prior surgical history, CT findings, source of internal hernia, open or laparoscopic surgery, and preoperative labs were recorded and compared. Fifty-six patients were found to have internal hernias and were included in our study. 80.3% were female and 86% had a previous Roux-en-Y gastric bypass procedure (RYGBP). Laparoscopy was the main approach for all groups. Ascites was present in 46% of the cases. Specifically, chylous ascites was observed in 27% of the total operations and was exclusively (100%) found in patients with gastric-bypass history. Furthermore, it was more commonly associated with Petersen’s defect (p

Postoperative dysphagia after anti-reflux surgery typically resolves in a few weeks. However, even after the initial swelling has resolved at 6 weeks, dysphagia can persist in 30% of patients necessitating esophageal dilation. The purpose of this study was to investigate the effect of esophageal dilation on postoperative dysphagia, the recurrence of reflux symptoms, and the efficacy of pneumatic dilations on postoperative dysphagia. A prospectively collected database was reviewed for patients who underwent partial/complete fundoplication with/without paraesophageal hernia repair between 2006 and 2014. Patient age, sex, BMI, DeMeester score, procedure type, procedure duration, length of stay, postoperative dysphagia, time to first pneumatic dilation, number of dilations, and the need for reoperations were collected. The study included 902 consecutive patients, 71.3% females, with a mean age of 57.8 ± 14.7 years. Postoperative dysphagia was noted in 26.3% of patients, of whom 89% had complete fundoplication (p < 0.01). Endoscopic dilation was performed in 93 patients (10.3%) with 59 (63.4%) demonstrating persistent dysphagia. Recurrent reflux symptoms occurred in 35 (37.6%) patients who underwent endoscopic dilation. Patients who underwent a dilation for symptoms of dysphagia were less likely to require a revisional surgery later than patients who had dysphagia but did not undergo a dilation before revisional surgery (17.2% vs 41.7%, respectively, p < 0.001) in the 4-year follow-up period. The duration of initial dilation from surgery was inversely related to the need for revisional surgery (p = 0.047), while more than one dilation was not associated with additive benefit. One attempt at endoscopic dilation of the esophagogastric fundoplication may provide relief in patients with postoperative dysphagia and can be used as a predictive factor for the need of revision. However, there is an increased risk for recurrent reflux symptoms and revisional surgery may ultimately be indicated for control of symptoms.

Background: Exercise following bariatric surgery is associated with better outcomes. We aimed to assess the level of interest in fitness programs, self-reported exercise duration, and perceived obs...

Social support after bariatric surgery is considered essential. Unfortunately, patient participation in such groups tends to be limited threatening their effectiveness. Facebook groups may provide a social support option that attracts more participation. The aim of this study was to describe our experience with the administration of a Facebook social support group and evaluate its perceived value by our bariatric patients. After IRB approval, all Facebook group posts since its establishment in 2015 were reviewed and a thematic analysis was undertaken. Group members also completed a survey related to their Facebook group experience and its perceived value. Responses were collected using 5-point Likert scales. In addition, 30 members were phone interviewed using open-ended questions and their responses were analyzed. Over 4 years, the group accumulated 12,507 posts, 104,053 comments, and 197,594 reactions. On average, members check the group page more than once per day. Ten common themes were identified in the submitted posts: questions, motivation related, education related, diet related, physical activity related, current status updates, sharing failures, social, random/humorous and other. Members reported that the group helped them do well with their procedure (3.3/5) particularly due to the motivation of others’ successful stories (3.5/5) and made them feel understood (3.9/5) even though it offered limited help controlling their eating habits (2.7/5). The phone interviews suggested that the Facebook group offered constant support, was simple to use, and provided the sole social support for many patients. They most appreciated the motivational posts that kept them on track and the assistance/comments of clinical staff. In contrast, they disliked repeated questions/spam and negative stories shared by some members. Facebook groups can provide effective social support to patients after bariatric surgery. Peers educate, answer questions, and motivate patients by sharing their positive experiences. Whether this online connectedness also positively impacts patient outcomes requires further study.

Obesity and its associated comorbidities represent a pervasive problem in the United States across all age groups. There are conflicting data regarding the effectiveness and postoperative recovery of bariatric surgery in elderly patients. The aim of this study was to compare outcomes of bariatric surgery across age groups. After obtaining institutional review board approval, patients with morbid obesity who underwent non-revisional laparoscopic Roux-en-Y gastric bypass (LRYGB) and sleeve gastrectomy (LSG) at our institution between 2011 and 2015 were included in this retrospective study. Patients were subdivided into five age groups

Improving operating room (OR) inefficiencies benefits the OR team, hospital, and patients alike but the available literature is limited. Our goal was, using a novel surgical application, to identify any OR incidents that cause delays from the time the patient enters the OR till procedure start (preparatory phase). We conducted an IRB approved, prospective, observational study between July 2018 and January 2019. Using a novel surgical application (ExplORer Surgical) three observers recorded disrupting incidents and their duration during the preparatory phase of a variety of general surgery cases. Specifically, the number and duration of anesthesia delays, unnecessary/distracting conversations, missing items, and other delays were recorded from the moment they started until they stopped affecting the normal workflow. Ninety-six OR cases were assessed. 20 incidents occurred in 18 (19%) of those cases. The average preparatory duration for all the cases was 20.7 ± 8.6 min. Cases without incidents lasted 19.5 ± 7.4 min while cases with incidents lasted 25.9 ± 11.2 min, p = 0.03. The average incident lasted 3.7 min, approximately 18% of the preparatory phase duration. The use of the ExplORer Surgical app allowed us to accurately record the incidents happening during the preparatory phase of various general surgery operations. Such incidents significantly prolonged the preparatory duration. The identification of those inefficiencies is the first step to targeted interventions that may eventually optimize the efficiency of preoperative preparation.

Localized orbital coupled cluster theory has recently emerged as an nonempirical alternative to DFT for large systems. Intuitively, one might expect such methods to perform less well for highly delocalized systems. In the present work, we apply both canonical CCSD(T) and a variety of localized approximations thereto to a set of expanded porphyrins -- systems that can switch between H\"uckel, figure-eight, and M\"obius topologies under external stimuli. Both minima and isomerization transition states are considered. We find that M\"obius(-like) structures have much stronger static correlation character than the remaining structures, and that this causes significant errors in DLPNO-CCSD(T) and even DLPNO-CCSD(T1) approaches, unless TightPNO cutoffs are employed. If sub-kcal/mol reproduction of canonical relative energies is required even for M\"obius-type systems (or other systems plagued by strong static correlation), then Nagy and Kallay's LNO-CCSD(T) method with "tight" settings can provide that, at much greater computational expense than either the PNO-LCCSD(T) or DLPNO-LCCSD(T) approaches but with still a much gentler CPU time scaling than canonical approaches. We would propose the present POLYPYR21 dataset as a benchmark for localized orbital methods, or more broadly, for the ability of lower-level methods to handle energetics with strongly varying degrees of static correlation., Comment: 27 pages; revised version. J. Chem. Theory. Comput., ASAP (2020)

Up to 50% of patients with vertical banded gastroplasty (VBG) experience failure or complications in the mid- and long-term and present for revisional bariatric surgery. This study aimed to review our experience for patient outcomes after VBG revisions and compare their benefits to those of primary laparoscopic Roux-en-Y gastric bypass (LRYGB) operations. Data from patients who underwent VBG revision between 2009 and 2015 at a center of excellence were reviewed. Patient demographics, symptoms, comorbidities, weight loss, reinterventions, reoperations, and hospital stay were analyzed and compared with those of primary LRYGB patients (control group). Fifty-two patients (88.5% female, 55 ± 9.6 years old) underwent revisional surgery during the study period (86.5% LRYGB, 11.5% VBG reversal, and 2% sleeve gastrectomy). Patients presented 17.3 ± 7.2 years after their VBG for weight regain (55.8%), dysphagia (19.2%), or both (25%). Patients who underwent conversion to LRYGB for weight regain and for mix-symptoms had similar weight loss to the control group (38.2 ± 11.8 vs 35.6 ± 7.7, p = 0.108), along with similar comorbidity resolution. However, even though the early (

Photoacids show a strong increase in acidity in the first electronic excited state, enabling real time studies of proton transfer in acid base reactions, proton transport in energy storage devices and biomolecular sensor protein systems. Several explanations have been proposed for what determines photoacidity, ranging from variations in solvation free energy to changes in electronic structure occurring along the four stages of the Förster cycle. Here we use picosecond nitrogen K edge spectroscopy to monitor the electronic structure changes of the proton donating group in a protonated aromatic amine photoacid in solution upon photoexcitation and subsequent proton transfer dynamics. Probing core to valence transitions locally at the amine functional group and with orbital specificity, we clearly reveal pronounced electronic structure, dipole moment and energetic changes on the conjugate photobase side. This result paves the way for a detailed electronic structural characterization of the photoacidity phenomenon

Using ultrafast X-ray absorption spectroscopy, we observe how a rhodium carbonyl catalyst is formed on femtosecond timescales and reveal the decisive orbital interactions which facilitate the efficient cleavage of an alkane C-H bond from solution.

Early excited state dynamics in the photodissociation of transition metal carbonyls determines the chemical nature of short-lived catalytically active reaction intermediates. However, time-resolved experiments have not yet revealed mechanistic details in the sub-picosecond regime. Hence, in this study the photoexcitation of ironpentacarbonyl Fe(CO)(5) is simulated with semi-classical excited state molecular dynamics. We find that the bright metal-to-ligand charge-transfer (MLCT) transition induces synchronous Fe-C oscillations in the trigonal bipyramidal complex leading to periodically reoccurring release of predominantly axial CO. Metaphorically the photoactivated Fe(CO)(5) acts as a CO geyser, as a result of dynamics in the potential energy landscape of the axial Fe-C distances and non-adiabatic transitions between manifolds of bound MLCT and dissociative metal-centered (MC) excited states. The predominant release of axial CO ligands and delayed release of equatorial CO ligands are explained in a unified mechanism based on the sigma*(Fe-C) anti-bonding character of the receiving orbital in the dissociative MC states. The photodissociation of transition metal carbonyls is involved in catalysis and synthetic processes. Here the authors, using semi-classical excited state molecular dynamics, observe details of the early stage dynamics in the photodissociation of Fe(CO)(5), including synchronous bursts of CO at periodic intervals of 90 femtoseconds.

C≡N bond scission can be a potential avenue for the functionalization of chemical bonds. We have conducted a computational study, using density functional theory (DFT) and ab initio multireference CASSCF methods, to unravel the intricate mechanistic pathways traversed in the copper-promoted, dioxygen-assisted reaction for the formation of aryl isocyanate species from aryl aldehyde. This aryl isocyanate species acts as an active species for C≡N bond cleavage of coordinated cyanide anion enabling nitrogen transfer to various aldehydes. Electronic structure analysis revealed that under all the reaction conditions radical-based pathways are operative, which is in agreement with the experimental findings. The major driving force is a Cu

The early excited state dynamics in the photodissociation of transition metal carbonyls determines the chemical nature of short-lived catalytically active reaction intermediates. However, time-resolved experiments have not yet revealed the mechanistic details in the sub-picosecond regime. Hence in this study, the photoexcitation of ironpentacarbonyl Fe(CO)5 has been simulated by semi-classical surface-hopping excited state molecular dynamics based on time-dependent density functional theory. We �find that the bright metal-to-ligand charge-transfer (MLCT) transition induces Fe-C oscillations in the trigonal bipyramidal complex leading to periodically reoccurring release of predominantly axial CO. Metaphorically the photoactivated Fe(CO)5 acts as a CO geyser, which we explain in terms of dynamics in the potential energy landscape of the axial Fe-C distances and non-adiabatic transitions between manifolds of bound MLCT and dissociative metal-centered(MC) excited states. The predominant release of axial CO ligands and a delayed release of equatorial CO ligands are explained in an unified mechanism based on the (sigma*)(Fe-C) anti-bonding character of the receiving orbital in the dissociative MC states both in the Franck-Condon region and at distorted geometries.

The early excited state dynamics in the photodissociation of transition metal carbonyls determines the chemical nature of short-lived catalytically active reaction intermediates. However, time-resolved experiments have not yet revealed the mechanistic details in the sub-picosecond regime. Hence in this study, the photoexcitation of ironpentacarbonyl Fe(CO)5 has been simulated by semi-classical surface-hopping excited state molecular dynamics based on time-dependent density functional theory. We �find that the bright metal-to-ligand charge-transfer (MLCT) transition induces Fe-C oscillations in the trigonal bipyramidal complex leading to periodically reoccurring release of predominantly axial CO. Metaphorically the photoactivated Fe(CO)5 acts as a CO geyser, which we explain in terms of dynamics in the potential energy landscape of the axial Fe-C distances and non-adiabatic transitions between manifolds of bound MLCT and dissociative metal-centered(MC) excited states. The predominant release of axial CO ligands and a delayed release of equatorial CO ligands are explained in an unified mechanism based on the (sigma*)(Fe-C) anti-bonding character of the receiving orbital in the dissociative MC states both in the Franck-Condon region and at distorted geometries.

Background Studies of patients who have undergone surgery while infected with COVID-19 have shown increased risks for adverse outcomes in both pulmonary complications and mortality. It has become clear that the risk of complications from perioperative COVID-19 infection must be weighed against the risk from delayed surgical treatment. Studies have also shown that prior bariatric surgery conveys protection against mortality from COVID-19 and that obesity is the biggest risk factor for mortality from COVID-19 infection in adults under 45 years of age. Studies in patients who have fully recovered from COVID-19 and underwent elective surgery have not become widely available yet. Objectives This multi-institutional case series is presented to highlight patients who developed COVID-19, fully recovered, and subsequently underwent elective bariatric surgery with 30-day outcomes available. Setting Nine bariatric surgery centers located across the United States. Methods This multicenter case series is a retrospective chart review of patients who developed COVID-19, recovered, and subsequently underwent bariatric surgery. Fifty-three patients are included, and 30-day morbidity and mortality were analyzed. Results Thirty-day complications included esophageal spasm, dehydration, and ileus. There were no cardiovascular, venous thromboembolism (VTE) or respiratory events reported. There were no 30- day mortalities. Conclusions Bariatric surgery has been safely performed in patients who made a full recovery from COVID-19 without increased complications due to cardiovascular, pulmonary, venous thromboembolism, or increased mortality rates.

The aerial oxidation of PdII to PdIV has emerged as an integral component of sustainable catalytic C-H functionalization processes. However, a proper understanding of the factors that control the viability of this oxidative process remains elusive. An investigation of the intricate mechanism of the transmetalation reaction of the aerial oxidative transformation of [(Me3 tacn)PdII Me2 ] (Me3 tacn=N,N',N''-trimethyl-1,4,7-triazacyclononane) to [(Me3 tacn)PdIV Me3 ]+ has been conducted by using DFT, along with multireference methods, such as second-order n-electron valence-state perturbation theory (NEVPT2) with complete active space self-consistent field theory (CASSCF). The present endeavor predicts that the thermodynamics and kinetics of the oxygen activation step are primarily dictated by the polarity of the solvents, which determine the amount of charge transfer to the oxygen molecule from the PdII center. Additionally, it is observed that the presence of a protic solvent has a significant effect on the spin-orbit coupling term at the minimum energy crossing point of the triplet and singlet surfaces. Moreover, it is shown that the intermetal ligand-transfer phenomenon is an important instance of an oxygen-assisted SN 2 reaction.

Realization of practical hydrogen storage in adsorbent materials is still elusive due to several insurmountable issues. In the case of chemical hydrogen storage, the roadblock arises from the failu...

C≡N bond scission accomplished by protonation, reductive cleavage and metathesis techniques are well-known to execute nitrogen transfer reactions. Herein, we have conducted an extensive computational study, using DFT and molecular dynamics simulations, to unravel the mechanistic pathways traversed in CuCN and CuBr2 promoted splitting of coordinated cyanide anion under a dioxygen atmosphere, which enables nitrogen transfer to various aldehydes. Our detailed electronic structure analysis using ab initio multi-reference CASSCF calculations reveal that both the promoters facilitate radical pathways, in agreement with the experimental findings. This is a unique instance of oxygen activation initiated by single electron transfer from the nitrile carbon, while the major driving force is the operation of the CuII/I redox cycle. Our study reveals that the copper salts act as the “electron pool” in this unique nitrogen transfer reaction forming aryl nitrile from aryl aldehydes.

C≡N bond scission accomplished by protonation, reductive cleavage and metathesis techniques are well-known to execute nitrogen transfer reactions. Herein, we have conducted an extensive computational study, using DFT and molecular dynamics simulations, to unravel the mechanistic pathways traversed in CuCN and CuBr2 promoted splitting of coordinated cyanide anion under a dioxygen atmosphere, which enables nitrogen transfer to various aldehydes. Our detailed electronic structure analysis using ab initio multi-reference CASSCF calculations reveal that both the promoters facilitate radical pathways, in agreement with the experimental findings. This is a unique instance of oxygen activation initiated by single electron transfer from the nitrile carbon, while the major driving force is the operation of the CuII/I redox cycle. Our study reveals that the copper salts act as the “electron pool” in this unique nitrogen transfer reaction forming aryl nitrile from aryl aldehydes.

Bariatric surgery is the most effective treatment for obesity; however, its utilization in older patients remains low. There is a dearth of literature on long-term effectiveness and safety of bariatric surgery in septuagenarian patients. The aim of this study was to compare the short- and long-term outcomes of bariatric surgery in this population.Patients who underwent primary laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) at our institution between 2011 and 2015 were included. Patients were divided into two age groups: 70 and ≥ 70 years. Outcomes included postoperative hospital length of stay (LOS), 30-day complications, up to 4-year complications, 90-day mortality, comorbidity resolution, and 4-year weight loss (BMI change-ΔΒΜΙ). The groups were also compared using multivariable analyses adjusting for potential confounders (gender, preoperative BMI, and type of procedure).Twenty-nine septuagenarians who underwent 21 LRYGB (72.4%) and 8 LSG (27.6%) were compared to 1016 patients aged 70 years operated on during the same time period. Additionally, following the multivariable analyses, the septuagenarians had higher LOS (3 vs 2.3 days, p = 0.01), 4-year complications (38% vs 23%, p = 0.012), and less comorbidities' resolution but similar 4-year ΔBMI (- 8.6 vs - 10, p = 0.421), and 30-day complications (10% vs 6%, p = 0.316).Bariatric surgery in carefully selected septuagenarians can be accomplished with acceptable safety and comparable postoperative weight loss at 4 years. Surgeons may consider broadening their selection criteria to include this patient subgroup but may allow the patients to reap its benefits if offered earlier in life.

Chylous ascites is often reported in cases with lymphatic obstruction or after lymphatic injuries such as intraabdominal malignancies or lymphadenectomies. However, chylous ascites is also frequently encountered in operations for internal hernias. We sought to characterize the frequency and conditions when chylous ascites is encountered in general surgery patients.Data from patients who underwent operations for CPT codes related to open and laparoscopic abdominal and gastrointestinal surgery in our tertiary hospital from 2010 to 2019 were reviewed. Patients with the postoperative diagnosis of internal hernia were identified and categorized into three groups: Internal Hernia with chylous ascites, non-chylous ascites, and no ascites. Demographics, prior surgical history, CT findings, source of internal hernia, open or laparoscopic surgery, and preoperative labs were recorded and compared.Fifty-six patients were found to have internal hernias and were included in our study. 80.3% were female and 86% had a previous Roux-en-Y gastric bypass procedure (RYGBP). Laparoscopy was the main approach for all groups. Ascites was present in 46% of the cases. Specifically, chylous ascites was observed in 27% of the total operations and was exclusively (100%) found in patients with gastric-bypass history. Furthermore, it was more commonly associated with Petersen's defect (p 0.001), while the non-chylous fluid group was associated with herniation through the mesenteric defect (p 0.001).Chylous ascites is a common finding during internal hernia operations. Unlike other more morbid conditions, identification of chylous ascites during an internal hernia operation appears innocuous. However, in the context of a patient with a history of RYGBP, the presence of chylous fluid signifies the associated small bowel obstruction is likely related to an internal hernia through a patent Petersen's defect.

INTRODUCTION: With increasing burden of obesity and liver disease in the United States, a better understanding of bariatric surgery in context of cirrhosis is needed. We described trends of hospital-based outcomes of bariatric surgery among cirrhotics and determined effect of volume status and type of surgery on these outcomes. METHODS: In this population-based study, admissions for bariatric surgery were extracted from the National Inpatient Sample using International Classification of Diseases, 9th and 10th Revision, Clinical Modification codes from 2004 to 2016 and grouped by cirrhosis status, type of bariatric surgery, and center volume. In-hospital mortality, complications, and their trends were compared between these groups using weighted counts, odds ratios [ORs], and logistic regression. RESULTS: Among 1,679,828 admissions for bariatric surgery, 9,802 (0.58%) had cirrhosis. Cirrhosis admissions were more likely to be in white men, had higher Elixhauser Index, and higher in-hospital complications rates including death (1.81% vs 0.17%), acute kidney injury (4.5% vs 1.2%), bleeding (2.9% vs 1.1%), and operative complications (2% vs 0.6%) (P < 0.001 for all) compared to those without cirrhosis. Overtime, restrictive surgeries have grown in number (12%–71%) and complications rates have trended down in both groups. Cirrhotics undergoing bariatric surgery at low-volume centers (

Postoperative dysphagia after anti-reflux surgery typically resolves in a few weeks. However, even after the initial swelling has resolved at 6 weeks, dysphagia can persist in 30% of patients necessitating esophageal dilation. The purpose of this study was to investigate the effect of esophageal dilation on postoperative dysphagia, the recurrence of reflux symptoms, and the efficacy of pneumatic dilations on postoperative dysphagia.A prospectively collected database was reviewed for patients who underwent partial/complete fundoplication with/without paraesophageal hernia repair between 2006 and 2014. Patient age, sex, BMI, DeMeester score, procedure type, procedure duration, length of stay, postoperative dysphagia, time to first pneumatic dilation, number of dilations, and the need for reoperations were collected.The study included 902 consecutive patients, 71.3% females, with a mean age of 57.8 ± 14.7 years. Postoperative dysphagia was noted in 26.3% of patients, of whom 89% had complete fundoplication (p0.01). Endoscopic dilation was performed in 93 patients (10.3%) with 59 (63.4%) demonstrating persistent dysphagia. Recurrent reflux symptoms occurred in 35 (37.6%) patients who underwent endoscopic dilation. Patients who underwent a dilation for symptoms of dysphagia were less likely to require a revisional surgery later than patients who had dysphagia but did not undergo a dilation before revisional surgery (17.2% vs 41.7%, respectively, p0.001) in the 4-year follow-up period. The duration of initial dilation from surgery was inversely related to the need for revisional surgery (p = 0.047), while more than one dilation was not associated with additive benefit.One attempt at endoscopic dilation of the esophagogastric fundoplication may provide relief in patients with postoperative dysphagia and can be used as a predictive factor for the need of revision. However, there is an increased risk for recurrent reflux symptoms and revisional surgery may ultimately be indicated for control of symptoms.

Purpose Over the past decade, an increasing number of bariatric surgeons are trained in fellowships annually despite only a modest increase in nationwide bariatric surgery volume. The study surveys the bariatric surgery job market trend in order to inform better career-choice decisions for trainees interested in this field. Materials and Methods A national retrospective cohort survey over an 11-year period was conducted. Bariatric surgery fellowship graduates from 2008 to 2019 and program directors (PDs) were surveyed electronically. Univariate analysis was performed comparing responses between earlier (2008–2016) and recent graduates (2017–2019). Results We identified a total of 996 graduates and 143 PDs. Response rates were 9% and 20% respectively (n = 88, 29). Sixty-eight percent of graduates felt there are not enough bariatric jobs for new graduates. Seventy-nine percent of PDs felt that it is more difficult to find a bariatric job for their fellows now than 5–10 years ago. Forty-eight percent of PDs felt that we are training too many bariatric fellows. Seventy-seven percent of all graduates want the majority of their practice to be comprised bariatric cases; however, only 42% of them reported achieving this. In the univariate analysis, recent graduates were less likely to be currently employed as a bariatric surgeon (64% vs. 86%, p = 0.02) and were less satisfied with their current case volume (42% vs. 66%, p = 0.01). Conclusions The temporal increase in bariatric fellowship graduates over the past decade has resulted in a significant decline in the likelihood of employment in a full-time bariatric surgical practice and a decline in surgeons’ bariatric case volumes.

Social support is important to optimize bariatric surgery outcomes, but limited tools exist for brief and effective assessment preoperatively. The aims of the study were to determine the extent to which two ratings of social support can predict bariatric surgery outcomes, and to examine any associations between these two methods.In this retrospective study, patients were included for whom the Cleveland clinic behavioral rating system (CCBRS) and Flanagan quality of life scale (FQoLS) scores were obtained as part of their preoperative psychosocial evaluation. They were followed up for 6 to 24 months after bariatric surgery. Linear and logistic regressions were performed with patients' CCBRS and FQoLS scores as independent variables, and percent excess weight loss (%EWL), length of stay (LOS), complications, readmissions and loss to follow-up as dependent variables. The prediction of CCBRS ratings from FQoLS social support items was also evaluated. A total of 415 patients were included in the analysis. There were significant associations between the CCBRS and three of the four relevant FQoLS self-ratings. As CCBRS and FQoLS scores increased, complications decreased significantly. The CCBRS alone additionally predicted decreased length of hospital stay and approached significance for predicting decreased readmission rates. There were no associations between %EWL and behavior ratings. The degree of patients' social support is associated with important bariatric surgery outcomes. It is possible to obtain this valuable information via the administration of brief assessments prior to bariatric surgery.

Social support after bariatric surgery is considered essential. Unfortunately, patient participation in such groups tends to be limited threatening their effectiveness. Facebook groups may provide a social support option that attracts more participation. The aim of this study was to describe our experience with the administration of a Facebook social support group and evaluate its perceived value by our bariatric patients.After IRB approval, all Facebook group posts since its establishment in 2015 were reviewed and a thematic analysis was undertaken. Group members also completed a survey related to their Facebook group experience and its perceived value. Responses were collected using 5-point Likert scales. In addition, 30 members were phone interviewed using open-ended questions and their responses were analyzed.Over 4 years, the group accumulated 12,507 posts, 104,053 comments, and 197,594 reactions. On average, members check the group page more than once per day. Ten common themes were identified in the submitted posts: questions, motivation related, education related, diet related, physical activity related, current status updates, sharing failures, social, random/humorous and other. Members reported that the group helped them do well with their procedure (3.3/5) particularly due to the motivation of others' successful stories (3.5/5) and made them feel understood (3.9/5) even though it offered limited help controlling their eating habits (2.7/5). The phone interviews suggested that the Facebook group offered constant support, was simple to use, and provided the sole social support for many patients. They most appreciated the motivational posts that kept them on track and the assistance/comments of clinical staff. In contrast, they disliked repeated questions/spam and negative stories shared by some members.Facebook groups can provide effective social support to patients after bariatric surgery. Peers educate, answer questions, and motivate patients by sharing their positive experiences. Whether this online connectedness also positively impacts patient outcomes requires further study.

Obesity and its associated comorbidities represent a pervasive problem in the United States across all age groups. There are conflicting data regarding the effectiveness and postoperative recovery of bariatric surgery in elderly patients. The aim of this study was to compare outcomes of bariatric surgery across age groups.After obtaining institutional review board approval, patients with morbid obesity who underwent non-revisional laparoscopic Roux-en-Y gastric bypass (LRYGB) and sleeve gastrectomy (LSG) at our institution between 2011 and 2015 were included in this retrospective study. Patients were subdivided into five age groups: 30, 30-39, 40-49, 50-59, and ≥ 60 years. Patient baseline demographics and comorbidities were collected. Postoperative outcomes including reinterventions/reoperations, 30-day-readmissions, 90-day-mortality, comorbidities' resolution, and change in BMI (ΔBMI) up to 4 years were recorded and compared. The groups were compared with ANOVA and chi-square tests and multivariable analyses.LRYGB was performed in 74.7% of the 1026 study patients. Patients ≥ 60 years old demonstrated lower preoperative BMI than patients 50 years (p 0.001). Patients 50-59 years old had increased length of stay compared to 30-39 (p = 0.003) and a higher prevalence of all comorbidities was found in older patients (p 0.001). There was no significant difference in 30-day-readmissions; 90-day-mortality; reoperations; and reinterventions among the study groups. The ΔBMI was higher in younger patients and comorbidity resolution was more likely in younger patients with the exception of obstructive sleep apnea.Bariatric surgery can be accomplished safely across all age groups with satisfiable postoperative weight loss. However, older age had higher hospital stay and convalescence and lower comorbidity resolution compared to younger patients. Thus, bariatric surgery should be offered earlier in life to allow the patients to reap its benefits.

We locally probe with picosecond N K-edge spectroscopy electronic structure changes along all stages of the Förster photocycle of a prototypical photoacid, and determine how photoacid behaviour is driven by the conjugate photobase side.

Comprehensive preparative patient education is a key element in bariatric patient success. The primary objective of this study was to compare attrition rates, demographics, and surgery outcomes between patients who participated in the online vs in-house preparative seminars. A retrospective chart review was performed involving patients who chose to participate in online vs in-house educational seminar between July of 2014 and December of 2016. The patients were divided into two groups based on their choice of educational seminar and tracked to see how many made it to an initial visit and to surgery. In those who had bariatric surgery, data was collected on age, type of insurance, length of stay (LOS), longest follow-up, and change in body mass index. Total of 1230 patients were included in this study. There was no difference in attrition rate to initial consultation visit (29.1% vs 29.9%), but there was a statistically higher attrition to surgery in the in-house seminar attendees (72.9%) compared to online participants (66.6%, p

Though dinitrosyl-iron complexes (DNICs) are largely believed to act as NO carriers, several experiments on model DNICs have suggested that they can also act as nitrating agents in presence of dioxygen. Oxygen activation by DNICs has been implicated as a possible route for protein tyrosine nitration (PTN), which leads to neurodegenerative disorders. Herein using static and dynamic theoretical techniques we unravel a previously unknown dual state mechanistic paradigm for dioxygen activation of a biomimetic nitrating DNIC complex leading to phenolic nitration. Our computations reveal that the model DNIC, the ground electronic state of which is singlet, has a low-lying triplet state and an inherent singlet–triplet spin-crossover of DNICs can be triggered by fluxional changes in the bite angle of the two NO ligands. The presence of a low-lying triplet state in the DNIC affords an avenue for O2 activation other than a direct O2 activation by O2-induced spin-crossover of the singlet ground state. These two low-lying channels facilitate the formation of a peroxynitrite species. Nitration of phenolic substrates is facilitated by the release of NO2. The corresponding minimum energy crossing points (MECP) have been located. Along the reaction path, the changes in the electronic structure scenarios have been studied and interpreted. Our report also sheds light on the plausible mechanistic pathway of PTN by reactive species formed once O2 activation by DNICs have been achieved.

A novel benzimidazole appended arylimide (pyromellitic, naphthalene and perylene) based covalent organic framework (COF) has been synthesized through the condensation polymerization pathway, by taking consideration of the special noncovalent interaction with carbon dioxide. Formation and chemical connectivities of these polymers were thoroughly investigated by 13 C NMR and FTIR studies. Presences of pores in these polymers have been primarily checked with FESEM and HRTEM observations, prior to adsorption studies. The pyromellitic diimide containing benzimidazole COF (BIBDZ) exhibit highest BET surface area, 177.095 m 2 g −1 with pore diameter of 30–32 angstorm among the COFs reported here which is also consistent with our computational study. Naphthalene diimide and the diaminobenzidine containing COF (NIBDZ) has the highest binding affinity with CO 2 i.e. 127.87 cc g −1 (14.56 wt%) at 195 K, than the other two COFs. On the other side BIBDZ has showed specific capacitance value of 88.4 F g −1 at 0.5 A g −1 current density in the 1M H 3 PO 4 electrolytic solution as well as remarkable retention of specific capacitance (93.61%) after 5000 galvanostatic charge discharge cycles.

Expanded porphyrins provide a versatile route to molecular switching devices due to their ability to shift between several π-conjugation topologies encoding distinct properties. Taking into account its size and huge conformational flexibility, DFT remains the workhorse for modeling such extended macrocycles. Nevertheless, the stability of Hückel and Möbius conformers depends on a complex interplay of different factors, such as hydrogen bonding, p···p stacking, steric effects, ring strain and electron delocalization. As a consequence, the selection of an exchange-correlation functional for describing the energy profile of topological switches is very difficult. For these reasons, we have examined the performance of a variety of wavefunction methods and density functionals for describing the thermochemistry and kinetics of topology interconversions across a wide range of macrocycles. Especially for hexa- and heptaphyrins, the Möbius structures have a pronouncedly stronger degree of static correlation than the Hückel and figure-eight structures, and as a result the relative energies of singly-twisted structures are a challenging test for electronic structure methods. Comparison of limited orbital space full CI calculations with CCSD(T) calculations within the same active spaces shows that post-CCSD(T) correlation contributions to relative energies are very minor. At the same time, relative energies are weakly sensitive to further basis set expansion, as proven by the minor energy differences between MP2/cc-pVDZ and explicitly correlated MP2-F12/cc-pVDZ-F12 calculations. Hence, our CCSD(T) reference values are reasonably well-converged in both 1-particle and n-particle spaces. While conventional MP2 and MP3 yield very poor results, SCS-MP2 and particularly SOS-MP2 and SCS-MP3 agree to better than 1 kcal mol-1 with the CCSD(T) relative energies. Regarding DFT methods, only M06-2X provides relative errors close to chemical accuracy with a RMSD of 1.2 kcal mol-1. While the original DSD-PBEP86 double hybrid performs fairly poorly for these extended p-systems, the errors drop down to 2 kcal mol-1 for the revised revDSD-PBEP86-NL, again showing that same-spin MP2-like correlation has a detrimental impact on performance like the SOS-MP2 results.

Expanded porphyrins provide a versatile route to molecular switching devices due to their ability to shift between several π-conjugation topologies encoding distinct properties. DFT remains the workhorse for modeling such extended macrocycles, when taking into account their size and huge conformational flexibility. Nevertheless, the stability of Hückel and Möbius conformers depends on a complex interplay of different factors, such as hydrogen bonding, π···π stacking, steric effects, ring strain, and electron delocalization. As a consequence, the selection of an exchange–correlation functional for describing the energy profile of topological switches is very difficult. For these reasons, we have examined the performance of a variety of wave function methods and density functionals for describing the thermochemistry and kinetics of topology interconversions across a wide range of macrocycles. Especially for hexa- and heptaphyrins, the Möbius structures have a stronger degree of static correlation than the Hückel and twisted-Hückel structures, and as a result the relative energies of singly twisted structures are a challenging test for electronic structure methods. Comparison of limited orbital space full CI calculations with CCSD(T) calculations within the same active spaces shows that post-CCSD(T) correlation contributions to relative energies are very minor. At the same time, relative energies are weakly sensitive to further basis set expansion, as proven by the minor energy differences between the extrapolated MP2/CBS energies estimated from cc-pV{T,Q}Z, diffuse-augmented heavy-aug-cc-pV{T,Q}Z and explicitly correlated MP2-F12/cc-pVDZ-F12 calculations. Hence, our CCSD(T) reference values are reasonably well-converged in both 1-particle and n-particle spaces. While conventional MP2 and MP3 yield very poor results, SCS-MP2 and particularly SOS-MP2 and SCS-MP3 agree to better than 1 kcal mol–1 with the CCSD(T) relative energies. Regarding DFT methods, the range-separated double hybrids, such as ωB97M(2) and B2GP-PLYP, outperform other functionals with RMSDs of 0.6 and 0.8 kcal mol–1, respectively. While the original DSD-PBEP86 double hybrid performs fairly poorly for these extended π-systems, the errors drop down to 1.9 kcal mol–1 for the revised revDOD-PBEP86-NL, which eliminates the same-spin correlation energy. Minnesota meta-GGA functionals with high fractions of exact exchange (M06-2X and M08-HX) also perform reasonably well, outperforming more robust and significantly less empirically parametrized functionals like SCAN0-D3.

Most patients pursuing bariatric surgery undergo mandated preoperative weight management programs. The purpose of this study was to assess whether preoperative mandated weight loss goals lead to improved perioperative morbidity, postoperative weight loss, and resolution of comorbidities. Data from patients who underwent primary laparoscopic Roux-en-Y gastric bypass (LRYGB), and laparoscopic sleeve gastrectomy (LSG) between October 2012 and October of 2015 was reviewed. Patients were divided in two groups: those with BMI of 35–45 were not required to achieve a weight loss goal prior to surgery (no-WLG group) while those with BMI > 45 were given a weight loss goal proportionate to their weight (WLG group). Body mass index (BMI), history of diabetes mellitus type-II (DM-II), hypertension (HTN), hyperlipidemia (HLD), and obstructive sleep apnea (OSA) were recorded at baseline and 4 years postoperatively. Length of hospital stay (LOS) and reinterventions were considered proxies for postoperative morbidity. A total of 776 patients, 81.4% LRYGB, were included in the study (age 45.1 ± 11.9). There was no difference in %ΔBMI, DM-II, HDL, HTN, LOS, or reinterventions among the two groups at 4 years postoperatively in both LRNY and LSG patients. This lack of difference persisted even when patients with similar BMI (43–45 vs 45.01–47) were compared. WLG group did not have decreased perioperative morbidity, nor improved weight loss and comorbidity resolution 4 years after surgery. While these findings should also be confirmed by multicenter trials, they question the value of mandated WLG prior to bariatric surgery as they seem ineffective and may limit patient access to surgery.

Background Improving operating room (OR) inefficiencies has financial and operational ramifications. However, their incidence has not been systematically studied, especially in bariatric surgery. Objectives The study aimed to identify the operational inefficiencies of the laparoscopic Roux-en-Y gastric bypass (LRYGB) procedure, specify the steps of the procedure, and investigate whether the inefficiencies are related to case-by-case variability, using a surgical application. Setting University Hospital, United States Methods From July 2018 to January 2019, we observed consecutive nonrevisional LRYGB cases. We used a surgical application to capture in real-time all the inefficiencies/incidents that occurred inside the operating room. The duration and time variability, along with the number of incidents of each step, were recorded. Additionally, a multivariable analysis was conducted to investigate whether patient factors (age, race, body mass index, and American Society of Anesthesiologists physical status classification), surgeon and surgical-technician experience, resident-assist, and case difficulty affect the number of incidents. Results Forty LRYGB procedures were observed. The duration of the procedural steps was linearly correlated with the number of incidents but case-to-case step duration variability was not. The steps that were linked with more inefficiencies included jejunojejunostomy creation that included more unrelated to the case conversations, and gastric pouch creation that had more anesthesia-related delays. Inefficiencies such as equipment malfunctions and missing supplies were equally distributed among all the steps. Multivariable analysis did not indicate that any of the tested factors were associated with the number of incidents. Conclusion The use of the surgical app allowed us to accurately record the duration, variability, and the undesired incidents of each LRYGB procedural step. Future studies should target interventions to minimize the inefficient procedural steps we have identified to optimize operating room efficiency.

The aerial oxidation of Pd

Background Bariatric surgery represents the most effective intervention for severe obesity available today; however, significant variability in postoperative outcomes exists. Effective tools that predict postoperative outcomes are needed for decision-making and patient counseling. Objectives We hypothesized that a validated behavioral assessment tool, the Cleveland Clinic Behavioral Rating Scale (CCBRS), would predict excess weight loss, health-related quality of life, depression, anxiety, and alcohol use after bariatric surgery. Setting Hospital in the United States. Methods A prospective observational study with 2-year planned follow-up was conducted with patients who completed a psychological clinical interview, the Short Form 36 (SF-36) v.2 Health Survey and brief self-report questionnaires measuring depression (PHQ-9), anxiety (GAD-7), and alcohol use (AUDIT) preoperatively. At the conclusion of the preoperative psychological evaluation, the psychologist completed the CCBRS. All questionnaires were readministered at 6, 12, 18, and 24 months after surgery. Generalized estimating equations were used to assess whether any CCBRS ratings predicted surgery outcomes. Results One hundred seventy-nine patients (113 Roux-en-Y gastric bypass and 66 sleeve gastrectomy) were included in the analyses. SF-36 scores, PHQ-9 scores, and the AUDIT total scores improved significantly after surgery, while GAD-7 scores did not change appreciably. Higher preoperative CCBRS ratings predicted higher SF-36 scores, and lower PHQ-9, GAD-7 and AUDIT scores. The CCBRS social support rating predicted higher postoperative percent excess weight loss. Conclusion A behavioral rating scale (CCBRS) completed before bariatric surgery predicted postoperative weight loss, quality of life, depression, and anxiety. Therefore, this tool may prove useful in patient counseling and expectation management before surgery.

Accepted manuscript version. Published version available at https://doi.org/10.1021/acs.jpclett.8b02191. We present a heuristic mechanism for the origin of the unusual triplet lasing from (E)-3-(((4-nitrophenyl)imino)methyl)-2H-thiochroman-4-olate·BF2. We demonstrate that whereas the moderate lifetime (1.03 μs) of the first triplet state (T1) prohibits triplet–triplet annihilation, the relatively faster S1 → T1 intersystem crossing and the 104 times smaller reverse intersystem crossing effectively help achieve population inversion in the T1 state. Furthermore, the triplet lasing wavelength (675 nm) for the tetramer does not overlap with the triplet–triplet absorptions wavelength, indicating that the spin-forbidden emission cross section is very large. Additionally, the almost complete absence of a vibrational progression in the vibronic phosphorescence spectrum of the monomer plays an important role in ensuring efficient triplet-state lasing from this organic material. Our results show that controlling the triplet-state lifetimes combined with lowering of the triplet–triplet absorption in the emission region and small vibronic coupling will be the key steps when designing novel organic triplet-lasing materials.