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To simulate a 200 nm photoexcitation in cyclobutanone to the n-3s Rydberg state, classical trajectories were excited from a Wigner distribution to the singlet state manifold based on excitation energies and oscillator strengths. Twelve singlet and 12 triplet states are treated using TD-B3LYP-D3/6-31+G** for the electronic structure, and the nuclei are propagated with the Tully surface hopping method. Using time-dependent density functional theory, we are able to predict the bond cleavage that takes place on the S1 surface as well as the ultrafast deactivation from the Rydberg n-3s state to the nπ*. After showing that triplet states and higher-lying singlet states do not play any crucial role during the early dynamics (i.e., the first 300 fs), the SA(6)-CASSCF(8,11)/aug-cc-pVDZ method is used as an electronic structure and the outcome of the non-adiabatic dynamic simulations is recomputed. Gas-phase ultrafast electron diffraction spectra are computed for both electronic structure methods, showing significantly different results. [ABSTRACT FROM AUTHOR]

This perspective offers an overview of the applications of the exact factorization of the electron–nuclear wavefunction to the domain of theoretical photochemistry, where the aim is to gain insights into the ultrafast dynamics of molecular systems via simulations of their excited-state dynamics beyond the Born–Oppenheimer approximation. The exact factorization offers an alternative viewpoint to the Born–Huang representation for the interpretation of dynamical processes involving the electronic ground and excited states as well as their coupling through the nuclear motion. Therefore, the formalism has been used to derive algorithms for quantum molecular-dynamics simulations where the nuclear motion is treated using trajectories and the electrons are treated quantum mechanically. These algorithms have the characteristic features of being based on coupled and on auxiliary trajectories, and have shown excellent performance in describing a variety of excited-state processes, as this perspective illustrates. We conclude with a discussion on the authors' point of view on the future of the exact factorization. [ABSTRACT FROM AUTHOR]

Background: Obesity is associated with multiple pregnancy-related complications. Bariatric surgery is frequently performed in women of childbearing age. While the impact of bariatric surgery on fertility and nutritional complications has been characterized, few studies on effects of bariatric surgery on obesity-related pregnancy complications exist. The purpose of this study is to examine the impact of bariatric surgery on pregnancy complications in a US insured population. Methods: Pregnancy-related claims from 2011–2019 were obtained from MarketScan commercial claims database for bariatric surgical patients and non-surgical patients with no history of obesity. Claims were grouped into 3 time periods: pre-surgery (time of first claim to date of surgery), peri-surgery (date of surgery to 24 month postoperatively), and post-surgery (> 24 month postoperatively). Peri-surgery period was defined based on the recommendation to avoid pregnancy for the first 12–24 months following surgery. Codes for both maternal and fetal pregnancy-related complications were extracted from the database. Standardized incidence rates in person-months (pms) were calculated and generalized estimating equations with Poisson distribution tested for differences in each category at the three time intervals. Results: The final cohort included 163612 female bariatric surgery patients. The rate of successful births was 3/1000 pms in the pre-surgery and peri-surgery period and increased to 4/1000 pms in the post-surgery period, compared to a rate of 7/1000 in the control group. The rate of pregnancy complications in the pre-surgery group was 4/1000 pms and dropped to 2/1000 pms in the peri- and post-surgery periods. The complication rate in the control group was 4/1000 pms. Conclusion: After bariatric surgery, the rate of pregnancy complications is lower than non-obese, non-bariatric surgery patients. Compared to before surgery, pregnancy complications decrease by 63% in the peri-surgery period and 57% in the post-surgery period. In the US, bariatric surgery is an important intervention for decreasing pregnancy complications in patients with obesity. [ABSTRACT FROM AUTHOR]

Full multiple spawning (FMS) offers an exciting framework for the development of strategies to simulate the excited-state dynamics of molecular systems. FMS proposes to depict the dynamics of nuclear wavepackets by using a growing set of traveling multidimensional Gaussian functions called trajectory basis functions (TBFs). Perhaps the most recognized method emanating from FMS is the so-called ab initio multiple spawning (AIMS). In AIMS, the couplings between TBFs—in principle exact in FMS—are approximated to allow for the on-the-fly evaluation of required electronic-structure quantities. In addition, AIMS proposes to neglect the so-called second-order nonadiabatic couplings and the diagonal Born–Oppenheimer corrections. While AIMS has been applied successfully to simulate the nonadiabatic dynamics of numerous complex molecules, the direct influence of these missing or approximated terms on the nonadiabatic dynamics when approaching and crossing a conical intersection remains unknown to date. It is also unclear how AIMS could incorporate geometric-phase effects in the vicinity of a conical intersection. In this work, we assess the performance of AIMS in describing the nonadiabatic dynamics through a conical intersection for three two-dimensional, two-state systems that mimic the excited-state dynamics of bis(methylene)adamantyl, butatriene cation, and pyrazine. The population traces and nuclear density dynamics are compared with numerically exact quantum dynamics and trajectory surface hopping results. We find that AIMS offers a qualitatively correct description of the dynamics through a conical intersection for the three model systems. However, any attempt at improving the AIMS results by accounting for the originally neglected second-order nonadiabatic contributions appears to be stymied by the hermiticity requirement of the AIMS Hamiltonian and the independent first-generation approximation. [ABSTRACT FROM AUTHOR]

Introduction: Obesity is an increasingly prevalent public health problem often associated with poorly controlled gastroesophageal reflux disease. Fundoplication has been shown to have limited long-term efficacy in patients with morbid obesity and does not address additional weight-related co-morbidities. Roux-en-Y gastric bypass (RYGB) is the gold standard operation for durable resolution of GERD in patients with obesity, and is also used as a salvage operation for GERD after prior foregut surgery. Surgeons report access to RYGB as surgical treatment for GERD is often limited by RYGB-specific benefit exclusions embedded within insurance policies, but the magnitude and scope of this problem is unknown. Methods: A 9-item survey evaluating surgeon practice and experience with insurance coverage for RYGB for GERD was developed and piloted by a SAGES Foregut Taskforce working group. This survey was then administered to surgeon members of the SAGES Foregut Taskforce and to surgeons participating in the SAGES Bariatrics and/or Foregut Facebook groups. Results: 187 surgeons completed the survey. 89% reported using the RYGB as an anti-reflux procedure. 44% and 26% used a BMI of 35 kg/m2 and 30 kg/m2 respectively as cutoff for the RYGB. 89% viewed RYGB as the procedure of choice for GERD after bariatric surgery. 69% reported using RYGB to address recurrent reflux secondary to failed fundoplication. 74% of responders experienced trouble with insurance coverage at least half the time RYGB was offered for GERD, and 8% reported they were never able to get approval for RYGB for GERD indications in their patient populations. Conclusion: For many patients, GERD and obesity are related diseases that are best addressed with RYGB. However, insurance coverage for RYGB for GERD is often limited by policies which run contrary to evidence-based medicine. Advocacy is critical to improve access to appropriate surgical care for GERD in patients with obesity. [ABSTRACT FROM AUTHOR]

Objective: Obesity is associated with increased cancer risk. Because of the substantial and sustained weight loss following bariatric surgery, postsurgical patients are ideal to study the association of weight loss and cancer. Methods: Retrospectively (1982–2019), 21,837 bariatric surgery patients (surgery, 1982–2018) were matched 1:1 by age, sex, and BMI with a nonsurgical comparison group. Procedures included gastric bypass, gastric banding, sleeve gastrectomy, and duodenal switch. Primary outcomes included cancer incidence and mortality, stratified by obesity‐ and non‐obesity‐related cancers, sex, cancer stage, and procedure. Results: Bariatric surgery patients had a 25% lower risk of developing any cancers compared with a nonsurgical comparison group (hazard ratio [HR] 0.75; 95% CI 0.69–0.81; p < 0.001). Cancer incidence was lower among female (HR 0.67; 95% CI 0.62–0.74; p < 0.001) but not male surgery patients, with the HR lower for females than for males (p < 0.001). Female surgery patients had a 41% lower risk for obesity‐related cancers (i.e., breast, ovarian, uterine, and colon) compared with nonsurgical females (HR 0.59; 95% CI 0.52–0.66; p < 0.001). Cancer mortality was significantly lower after surgery in females (HR 0.53; 95% CI 0.44–0.64; p < 0.001). Conclusions: Bariatric surgery was associated with lower all‐cancer and obesity‐related cancer incidence among female patients. Cancer mortality was significantly lower among females in the surgical group versus the nonsurgical group. [ABSTRACT FROM AUTHOR]

Ab Initio Multiple Spawning (AIMS) simulates the excited-state dynamics of molecular systems by representing nuclear wavepackets in a basis of coupled traveling Gaussian functions, called trajectory basis functions (TBFs). New TBFs are spawned when nuclear wavepackets enter regions of strong nonadiabaticity, permitting the description of non-Born–Oppenheimer processes. The spawning algorithm is simultaneously the blessing and the curse of the AIMS method: it allows for an accurate description of the transfer of nuclear amplitude between different electronic states, but it also dramatically increases the computational cost of the AIMS dynamics as all TBFs are coupled. Recently, a strategy coined stochastic-selection AIMS (SSAIMS) was devised to limit the ever-growing number of TBFs and tested on simple molecules. In this work, we use the photodynamics of three different molecules—cyclopropanone, fulvene, and 1,2-dithiane—to investigate (i) the potential of SSAIMS to reproduce reference AIMS results for challenging nonadiabatic dynamics, (ii) the compromise achieved by SSAIMS in obtaining accurate results while using the smallest average number of TBFs as possible, and (iii) the performance of SSAIMS in comparison to the mixed quantum/classical method trajectory surface hopping (TSH)—both in terms of its accuracy and computational cost. We show that SSAIMS can accurately reproduce the AIMS results for the three molecules considered at a much cheaper computational cost, often close to that of TSH. We deduce from these tests that an overlap-based criterion for the stochastic-selection process leads to the best agreement with the reference AIMS dynamics for the smallest average number of TBFs. [ABSTRACT FROM AUTHOR]

Autocrine and paracrine signaling regulating adipogenesis in white adipose tissue remains largely unclear. Here we used single-cell RNA-sequencing (RNA-seq) and single nuclei RNA-sequencing (snRNA-seq) to identify markers of adipose progenitor cells (APCs) and adipogenic modulators in visceral adipose tissue (VAT) of humans and mice. Our study confirmed the presence of major cellular clusters in humans and mice and established important sex and diet-specific dissimilarities in cell proportions. Here we show that bone morphogenetic protein (BMP)-binding endothelial regulator (BMPER) is a conserved marker for APCs and adipocytes in VAT in humans and mice. Further, BMPER is highly enriched in lineage negative stromal vascular cells and its expression is significantly higher in visceral compared to subcutaneous APCs in mice. BMPER expression and release peaked by day four post-differentiation in 3T3-L1 preadipocytes. We reveal that BMPER is required for adipogenesis both in 3T3-L1 preadipocytes and in mouse APCs. Together, this study identified BMPER as a positive modulator of adipogenesis.scRNA-seq and snRNA-seq data identified BMPER, as a potential marker of adipogenic adipose progenitor cells in both human and mouse visceral adipose tissue and in vitro studies showed that BMPER is a critical regulator of adipogenesis. [ABSTRACT FROM AUTHOR]

Introduction: Roux-en-Y gastric bypass (RYGB) is the gold standard operation for gastroesophageal reflux disease (GERD) in patients with severe obesity, but there is variability in surgeon opinion regarding whether small type I hiatal hernias (HH) require routine repair concurrently with RYGB. We sought to examine whether leaving small type I HHs unrepaired during RYGB affected GERD outcomes. Methods: Pre-operatively our patients all receive endoscopy, and select patients with reflux symptoms receive esophagram based on attending surgeon practice and preference. We routinely repair paraesophageal hernias (PEH) concurrently with RYGB, but refrain from repairing small type I HH if, intra-operatively, the gastric fat pad and cardia are below the diaphragm with no evidence of retraction into the mediastinum. Records from 268 consecutive patients undergoing primary RYGB between January 2016 and February 2021 who completed pre-operative GERD–HRQL assessments were reviewed for presence of type I HH or PEH. Mann–Whitney U tests examined the pre-operative to post-operative change in GERD–HRQL in patients with type I HH left unrepaired at the time of RYGB (HH group) and patients with no hernia (NH group). Results: Pre-operatively, GERD–HRQL scores were not statistically different between HH group (median = 7, mean = 8.5, n = 100) and NH group (median = 6.5, mean = 7.2, n = 141) (p > 0.05). Post-operatively, there was no increase in GERD–HRQL scores patients whose hernias were left unrepaired. Neither group had clinically pathologic post-operative GERD–HRQL scores, with median 6 months scores of 1 for HH group (n = 68) versus 1.5 for NH group (n = 90) (p > 0.05), and median 12 months scores of 1.5 for HH group (n = 40) versus 1 for NH group (n = 56) (p > 0.05). Conclusion: Repair of small type I HH is not necessary to achieve effective, durable resolution of reflux symptoms with RYGB. Omitting repair reduces operative time, cost, and potential risk without adverse impact on post-operative reflux symptoms. [ABSTRACT FROM AUTHOR]

Introduction: Our aim was to evaluate the diagnostic yield of routine preoperative esophagogastroduodenoscopy (p-EGD) in patients undergoing bariatric surgery. Many medical problems that are common in patients with obesity, including gastroesophageal reflux disease (GERD) and hiatal hernias, have important implications for patients undergoing bariatric surgery. While p-EGD is considered standard of care prior to antireflux surgery, the role of p-EGD in bariatric surgery patients remains controversial. Methods and procedures: We performed a retrospective chart review of 885 patients who underwent primary bariatric surgery at a university hospital-based bariatric surgery program between March 2011 and February 2022. Clinical history, demographics, and preoperative EGD reports were reviewed for abnormal findings. Results: Of the 885 patients evaluated in this study, one or more abnormal EGD findings were observed in 83.2% of patients. More than half of our patients (54.7%) presented with history of heartburn, reflux, or GERD. EGD findings demonstrated a hernia in 43.1% of patients [(Type I: 40.6%; Type II: 0.5%; Type III: 2.1%)]. 68.0% of patients were biopsied. Among patients who were biopsied, other findings included gastritis (32.4%), esophagitis (8.0%), eosinophilic esophagitis (4.7%), or duodenitis (2.7%). We found ulcers in 6.7% of patients. Pathology was consistent with H. pylori in 9.8% of biopsies taken and consistent with BE in 2.7%. Following routine p-EGD, 11.2% of patients were placed on PPI and 8.3% were recommended to stop NSAIDs. Conclusion: Gastroesophageal reflux disease and associated pathology are common in the bariatric population. Preoperative EGD in patients undergoing bariatric surgery frequently identifies clinically significant UGI pathology. This may have important implications for medical and surgical management. Given the rate of abnormal preoperative endoscopic findings in obese patients, the work-up for bariatric surgery should align with the current recommendations for foregut surgery. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to compare the relationship of intramural sports and Division III athletic participation to retention and academic success in first-year college students. A first-year student cohort (n = 568) was grouped into four categories: no participation, student-athlete, intramural participant, and participant in both. There was no statistically significant difference in academic success among the participant groups, F(6, 1084) =.626, p =.710. Both the student-athlete and intramural participant groups were retained at a higher rate than the no participation group, 4.65% and 10.48%, respectively. Of the 46 student-athletes who discontinued playing varsity sports, only 17 remained at the institution. This investigation supports that intramural sports and Division III varsity athletic participation does not negatively affect grade point average and credit hours earned in first-year students, while demonstrating a positive relationship with retention. The results also highlight the need for intentional intervention and research related to the disengaged student-athlete. [ABSTRACT FROM AUTHOR]

Objective: This retrospective study incorporated long‐term mortality results after different bariatric surgery procedures and for multiple age at surgery groups. Methods: Participants with bariatric surgery (surgery) and without (non‐surgery) were matched (1:1) for age, sex, BMI, and surgery date with a driver license application/renewal date. Mortality rates were compared by Cox regression, stratified by sex, surgery type, and age at surgery. Results: Participants included 21,837 matched surgery and non‐surgery pairs. Follow‐up was up to 40 years (mean [SD], 13.2 [9.5] years). All‐cause mortality was 16% lower in surgery compared with non‐surgery groups (hazard ratio, 0.84; 95% CI: 0.79‐0.90; p < 0.001). Significantly lower mortality after bariatric surgery was observed for both females and males. Mortality after surgery versus non‐surgery decreased significantly by 29%, 43%, and 72% for cardiovascular disease, cancer, and diabetes, respectively. The hazard ratio for suicide was 2.4 times higher in surgery compared with non‐surgery participants (95% CI: 1.57‐3.68; p < 0.001), primarily in participants with ages at surgery between 18 and 34 years. Conclusions: Reduced all‐cause mortality was durable for multiple decades, for multiple bariatric surgical procedures, for females and males, and for greater than age 34 years at surgery. Rate of death from suicide was significantly higher in surgery versus non‐surgery participants only in the youngest age at surgery participants. [ABSTRACT FROM AUTHOR]

This document is an abstract from the Journal of Clinical & Translational Science. It includes summaries of several research studies. The first study examines the impact of a community-engaged project on telehealth acceptability among Latino farmworkers. The second study explores the use of dissemination grants to share research findings with community impact. The third study investigates the effects of racial discrimination on stress biomarkers among African Americans. The fourth study examines the association between weight stigma and mental health symptoms following bariatric surgery. The fifth study focuses on the development of recovery community organizations in rural areas. The final study explores factors underlying personal medical preparedness during disasters. [Extracted from the article]

Purpose: Overvaluation of shape and weight (OSW) involves defining self-worth by body shape/weight. Among persons seeking bariatric surgery, cross-sectional studies have found associations between OSW, depressive symptoms, and disordered eating. Materials and Methods: Relationships among OSW, depressive symptoms, binge eating symptoms, and BMI were analyzed both cross-sectionally and over time among 145 adults who had bariatric surgery. Participants completed the following measures pre-surgery and 1.5 to 3 years post-surgery: Eating Disorder Examination Questionnaire (EDE-Q), Binge Eating Scale, Patient Health Questionnaire, and body weight and height. OSW was measured by averaging two items on the EDE-Q which ask participants to rate how much their weight/shape influences how they judge themselves as a person. Analyses included Wilcoxon signed-ranks, bootstrapped Pearson correlations, and bootstrapped hierarchical linear regressions. Results: OSW was significantly associated with depressive symptoms and binge eating symptoms both pre- and post-surgery, but was not associated with BMI at either timepoint. Improvements in OSW were associated with concurrent changes in depression and binge eating; reductions in BMI were not significantly associated with changes in any of these variables. Conclusions: Findings suggest that self-evaluation is more important in regard to changes in depressive and binge eating symptoms than is BMI (and vice versa), and support the importance of assessing and treating psychological considerations among persons seeking bariatric surgery. [ABSTRACT FROM AUTHOR]

Objective: Many individuals who undergo bariatric surgery have experienced repeated unsuccessful diet attempts and negative messages from healthcare providers, family, and others about their weight. Research pre- and post-operatively has taken a pathological or risk-based approach, investigating psychiatric problems and disordered eating. In contrast, the current study explores resilience in this population. Methods: Participants were 148 bariatric surgery patients. Participants completed measures pre-operatively and 1.5–3 years post-operatively, including the Binge Eating Scale, Eating Disorder Examination Questionnaire, Patient Health Questionnaire, Generalized Anxiety Questionnaire, Impact of Weight on Quality of Life, Coping Responses Inventory, and Duke Social Support and Stress Scales. The Connor-Davidson Resilience Scale was measured post-operatively. Results: Correlations demonstrated a significant association between post-operative resilience and lower symptoms of binge eating, disordered eating, depression, anxiety, and impact of weight on quality of life. Resilience was also associated with greater social support and less social stress, and greater use of approach coping strategies. Resilience was significantly associated with improvements in symptoms of binge eating, disordered eating, depression, anxiety, and impact of weight on quality of life from pre- to post-operative assessments. In regression models, associations remained significant after controlling for psychosocial variables at baseline (e.g., binge eating symptoms pre-operatively) and demographic covariates. Conclusions: Psychological resilience has been under-studied in the literature on obesity and bariatric surgery, with a primary focus on risk factors for poor outcomes. This study was among the first to investigate associations between resilience and post-operative psychological outcomes. Results suggest the field would benefit from consideration of patient resilience in psychological assessments and interventions. [ABSTRACT FROM AUTHOR]

Background: High rates of attrition to post-bariatric surgical care continue to be common, despite recommendations for lifelong follow-up. There is little available work focusing on the etiology of attrition to post-bariatric surgical follow-up. Patient-reported outcomes (PROs) are metrics of patients' perceptions of their own health and have been used for their predictive value in other specialties. The relationships between PROs and loss to follow-up have not been explored. Methods: PRO data from patients who met the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) definition of loss to follow-up at 1-year postoperatively were reviewed and compared to patients who were compliant with 1-year follow-up. Patient-reported outcomes measurement information system (PROMIS) measures are routinely collected pre- and postoperatively at our institution using a series of validated computer-adaptive tests that assess depression, satisfaction with social roles, pain interference, and physical function. A series of univariate logistic regressions tested whether baseline PROs or change in PROs from baseline to 6-month postoperatively predicted loss to follow-up at 1 year. Results: Neither baseline PROs nor change in depression, satisfaction with social roles, pain interference, or physical function were significant predictors of loss to follow-up. Similarly, patient state of residence, Charlson Comorbidity Index, BMI, and percent excess weight loss were not significant predictors of follow-up attrition. Conclusion: The PROs in this study were not significant predictors of loss to follow-up at 1-year postoperatively. The rate of bariatric procedures continues to increase nationally, so does the potential for late post-surgical complications. Given the potential impact of loss to follow-up on adverse late post-surgical outcomes, there is a need to facilitate long-term post-surgical follow-up and more investigation is needed to identify and intervene on underlying causes of bariatric patient follow-up attrition. [ABSTRACT FROM AUTHOR]

Background: Currently, there is a relative paucity of literature regarding the management of symptomatic congenital diaphragmatic hernia of the foramen of Morgagni in the adult. This study aims to describe our unique surgical technique and outcomes in adult patients undergoing laparoscopic repair of symptomatic Morgagni hernia. Methods: This is a retrospective review of adult patients from 2003 to 2020 who underwent a laparoscopic Morgagni hernia repair at our institution. All patients underwent a similar laparoscopic approach, utilizing the surgical principles of reduction of intra-abdominal contents, complete resection of the hernia sac, followed by primary repair of the hernia defect and mesh reinforcement with permanent mesh if the primary repair was subjectively under tension. Results: The study population consisted of 12 consecutive patients with a Morgagni hernia. Patients presented with a variety of symptoms attributed to the hernia, including pain 83% (n = 10), respiratory symptoms and shortness of breath 58% (7), and gastrointestinal obstruction 25% (3). Other complaints included: nausea 33% (4), reflux 50% (6), early satiety 8% (1), palpitations 16% (2), a gurgling sensation in the chest 8% (1), and weight loss 8% (1). Primary repair was possible in all patients following complete reduction of hernia contents including the hernia sac. Mesh reinforcement was used in 5 of 12 patients. Average surgical operative time was 93 (± 37) min. Median length of stay was 1.3 days (range 0.5–5.5 days). At a median follow-up of 10.9 months (IQR 8.0–41.5 months), all symptoms attributed to the hernia had resolved. No recurrences were identified. Conclusions: Adults with symptomatic Morgagni hernia should undergo surgical repair. A laparoscopic approach utilizing the surgical principles of reduction of intra-abdominal contents, complete resection of the hernia sac, followed by primary repair of the hernia defect (when possible), with or without mesh reinforcement can be performed safely and effectively. [ABSTRACT FROM AUTHOR]

Purpose: In spite of widespread recommendations for lifelong patient follow-up with a bariatric provider after bariatric surgery, attrition to follow-up is common. Over the past two decades, many programs have sought to expand access to care for patients lacking insurance coverage for bariatric surgery by offering "self-pay" packages; however, the impact of this financing on long-term follow-up is unclear. We sought to determine whether payer status impacts loss to follow-up within 1 year after bariatric surgery. Materials and Methods: Records of 554 consecutive patients undergoing bariatric surgery who were eligible for 1-year post-surgical follow-up between 2014 and 2019 were retrospectively reviewed. Multiple logistic regression examined the relationship between demographics, psychological variables, payer status, and loss to follow-up. Results: Self-pay status more than tripled the odds of loss to follow-up (OR = 3.44, p < 0.01) at 1 year following surgery. Males had more than double the odds of attrition (OR = 2.43, p < 0.01), and members of racial and ethnic minority groups (OR = 2.51, p < 0.05) were more likely to experience loss. Conclusions: Self-pay patients, males and members of racial and ethnic minority groups, may face additional barriers to long-term access to postoperative bariatric care. Further investigation is greatly needed to develop strategies to overcome barriers to and disparities in long-term post-surgical care for more frequently lost groups. [ABSTRACT FROM AUTHOR]

Over the past decades, an important number of methods have been developed to simulate the nonadiabatic dynamics of molecules, that is, the dynamics of molecules beyond the Born–Oppenheimer approximation. These nonadiabatic methods differ in the way they approximate the dynamics emanating from the time-dependent molecular Schrödinger equation. In 1990, Tully devised a series of three one-dimensional model systems to test the approximations of the method called trajectory surface hopping. The Tully models were designed to probe different scenarios of nonadiabatic processes, such as single and multiple nonadiabatic (re)crossings. These one-dimensional models rapidly became the testbed for any new nonadiabatic dynamics strategy. In this work, we present a molecular perspective to the Tully models by highlighting a correspondence between these simple one-dimensional models and processes happening during the excited-state dynamics of molecules. More importantly, each of these nonadiabatic processes can be connected to a given exemplary molecular system, and we propose here three molecules that could serve as molecular Tully models, reproducing some of the key features of the original models but this time in a high-dimensional space. We compare trajectory surface hopping with the ab initio multiple spawning for the three molecular Tully models and highlight particular features and differences between these methods resulting from their distinct approximations. We also provide all the necessary information – initial conditions and all required parameters for the dynamics as well as the electronic structure – employed in our simulations such that the molecular Tully models can become in the future a unified and standardized test for ab initio nonadiabatic molecular dynamics methods. The molecular Tully models also offer an exciting link between the world of low-dimensional model systems for nonadiabatic dynamics and the excited-state dynamics of molecular systems in their full dimensionality. [ABSTRACT FROM AUTHOR]

Over the last 30 years, computational biologists have developed increasingly realistic mathematical models of the regulatory networks controlling the division of eukaryotic cells. These models capture data resulting from two complementary experimental approaches: low-throughput experiments aimed at extensively characterizing the functions of small numbers of genes, and large-scale genetic interaction screens that provide a systems-level perspective on the cell division process. The former is insufficient to capture the interconnectivity of the genetic control network, while the latter is fraught with irreproducibility issues. Here, we describe a hybrid approach in which the 630 genetic interactions between 36 cell-cycle genes are quantitatively estimated by high-throughput phenotyping with an unprecedented number of biological replicates. Using this approach, we identify a subset of high-confidence genetic interactions, which we use to refine a previously published mathematical model of the cell cycle. We also present a quantitative dataset of the growth rate of these mutants under six different media conditions in order to inform future cell cycle models. [ABSTRACT FROM AUTHOR]

Background: We evaluated quality of life among bariatric surgery patients using patient-reported outcomes (PROs). We hypothesized that physical function would improve after bariatric surgery. Methods: We prospectively collected PROs beginning in December 2015. We used the validated Patient-Reported Outcomes Measurement Information System (PROMIS) instruments because of their broad applicability and ability to use computer-adapted technology to survey. Measures are repeated at clinic visits, both pre- and postoperatively. Data were reviewed through February 2018. Data were analyzed comparing pre- and postop physical function PRO (PF PRO) by procedure: laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (LSG). Additional variables were included in an adjusted linear mixed-effects regression model in order to isolate the effect of surgery on PF PRO over time. Results: This cohort included 279 bariatric surgery patients. The mean follow-up time was 1.5 years after surgery. The procedure groups were similar in terms of age and race but differed by gender and preoperative BMI. The PF-PRO measure showed significant improvement following surgery for both procedures. Conclusion: Patient-reported physical function improved significantly after bariatric surgery. There was no significant difference between procedures. [ABSTRACT FROM AUTHOR]

Simulating the dynamics of a molecule initiated in an excited electronic state constitutes a rather challenging task for theoretical and computational chemistry, as such dynamics leads to a strong coupling between nuclear motion and electronic states, that is, a breakdown of the Born–Oppenheimer approximation. This New Views article proposes a brief overview on recent theoretical developments aiming at simulating the excited-state dynamics of molecules – nonadiabatic molecular dynamics – focusing in particular on strategies employing travelling basis functions to portray the dynamics of nuclear wavefunctions. We start by discussing the central equations for nonadiabatic molecular dynamics in a Born–Huang representation. We then propose a comparison between two commonly employed strategies to simulate the excited-state dynamics of molecular systems in their full configuration space, Ab Initio Multiple Spawning (AIMS) and Trajectory Surface Hopping (TSH). The equations of motion for the two techniques are compared and used to contrast their respective description of phenomena involving the decoherence of nuclear wavepackets. Some recent works and developments of the AIMS method are then summarised. This New Views article ends with a highlight on the Exact Factorisation of the molecular wavefunction and how this approach contrasts with the more conventional Born–Huang picture when it comes to the description of photophysical and photochemical processes. [ABSTRACT FROM AUTHOR]

Background: Gastroesophageal reflux disease (GERD) affects two thirds of the American population. Obesity is also a disease that affects two thirds of the population. The pathophysiology of reflux disease is reasonably understood, however, the degree to which obesity affects this disease remains poorly defined. Therefore the approach to GERD in the obese patient requires special attention and its own algorithm.Methods: A literature search was conducted to consolidate the current available literature on GERD and its management in the obese. In addition, the authors reviewed the literature and present expert opinion on controversial topics.Results: It is well established that GERD is increased in obesity and the pathophysiology is reviewed. Management options for GERD are discussed, with a focus on the obese population. Management strategies including fundoplication and gastric bypass are discussed. In addition, bariatric surgery in the setting of GERD is also reviewed.Conclusions: Currently this is an extremely controversial topic and this white paper presents a strong review of the literature to help guide the management of this challenging disease in this population. Expert recommendations are given throughout the paper based upon the current available data. [ABSTRACT FROM AUTHOR]

Background: Individuals seeking bariatric surgery evidence risk for binge and disordered eating behaviors, which can lead to poorer post-surgical weight loss outcomes. Use of avoidant coping strategies to manage stress, along with symptoms of depression, are associated with disordered eating in the general population. However, the role of coping has not been examined among candidates for bariatric surgery, and coping and depression have rarely been considered in combination. Given the emerging standard that psychologists are involved in evaluations and treatment before and after surgery, consideration of these variables is clinically relevant. Methods: Participants were 399 patients undergoing pre-surgical bariatric psychological assessment. Hierarchical linear regression analyses tested whether gender, age, and BMI; approach and avoidance coping; and depression and anxiety were associated with disordered eating (binge eating, restraint, eating concerns, shape concerns, weight concerns) in a cross-sectional study design. Results: In initial steps of the model controlling demographic variables, approach coping predicted less and avoidance coping predicted more disordered eating across most outcomes examined. In models including depression and anxiety, avoidance (but not approach) coping remained a relevant predictor. The effects of depression were also quite robust, such that participants who were more depressed reported more disordered eating. More anxious participants reported more restrained eating. Conclusions: Avoidance coping and depressive symptoms emerged as key variables in understanding recent disordered eating among patients considering bariatric surgery. Pre-surgical psychological evaluations and treatment approaches could be enhanced with consideration of patient coping strategies, particularly avoidant coping responses to stress, independent of psychological distress. [ABSTRACT FROM AUTHOR]

The deactivation dynamics of 1,1-difluoroethylene after light excitation is studied within the surface hopping formalism in the presence of 3s and 3p Rydberg states using multi-state second order perturbation theory (MS-CASPT2). Due to the proximity of the Rydberg π-3s state with the ππ* state, the states are mixed favoring ultrafast exchange of population via a conical intersection that closely resembles the equilibrium structure. After excitation, it is found that the π-3s state acts as a doorway state, trapping the population and delaying internal conversion to the ππ* state, from which deactivation to the closed-shell ground state takes place. Besides the conical intersection between the π-3s and ππ* states, five additional conical intersections between the ππ* state and the ground state are found, indicating that after the system is excited, it stretches the C=C bond before it twists and pyramidalizes at any of the carbon atoms, in the spirit of a hula-twist mechanism. [ABSTRACT FROM AUTHOR]

Background: While there are various techniques to create the gastrojejunostomy during a laparoscopic Roux-en-Y gastric bypass (LRYGB), many surgeons prefer using a circular stapler. One drawback of this method, however, is the higher incidence of surgical site infections (SSIs). To investigate the effect of a dual ring wound protector on SSIs during LRYGB.Methods: In April 2016, our bariatric surgical group implemented an intervention whereby a dual ring wound protector in conjunction with a conical EEA stapler introducer was used when creating the gastrojejunostomy. SSIs from pre- and post-intervention were compared using Fisher’s exact test. Only LRYGBs performed with a circular stapler were included in our analysis. Student’s t test and χ2 were used to compare pre- and post-intervention groups with respect to demographics and co-morbidities.Results: Between April 2015 and January 31st, 2017, our surgeons performed 158 LRYGBs using a circular stapler for the gastrojejunostomy. There were 84 patients (53%) in the pre-intervention group and 74 (47%) in the post-intervention group. The pre- and post-intervention groups were not statistically different. The SSI rate for the pre-intervention group was 9.5% while the SSI rate was 1.35% in the post-intervention group (p = 0.0371). The use of a dual ring wound protector for LRYGBs with circular stapled gastrojejunostomy was associated with an 86% relative risk reduction in SSIs.Conclusion: Using a dual ring wound protector in conjunction with a conical EEA introducer for LRYGBs with circular stapled gastrojejunostomy significantly decreased SSIs. [ABSTRACT FROM AUTHOR]

This paper draws on institutional and experimental economics to investigate the role of exogenous and endogenous rules in irrigation systems. The hypotheses we examine argue that despite the differences between socio-economic and political settings, (1) endogenous rule-crafting can help water users to overcome appropriation and provision dilemmas in water-scarce environments like in the East Mediterranean countries and that (2) in market-like water governance systems, institutions other than the market itself, are less influential for overcoming appropriation and provision dilemmas than in hybrid governance systems. These hypotheses are being tested comparing the results of field experiments conducted in Jordan, the Republic of Cyprus and North Cyprus with 70 farmers. Field experiments simulate asymmetric access to resources and are based on variations of the irrigation game by Cardenas et al. to model and test asymmetric distribution of investment, harvest and revenue that favours upstream users. Empirical evidence shows that externally imposed allocation rules are able to bring in more equal distribution of revenue among upstream–downstream users but is likely to reduce the volume of investment and revenue, without resolving issues of free-riding. The authors argue that given the opportunity, water users (small farmers in our experiments) are able to craft their own rules improving the overall performance of the group in terms of investment and revenue, with a parallel improvement of equity in distribution. The implications and policy relevance of such findings are briefly discussed as they contradict typical practices of top-down policy delivery in the selected cases. [ABSTRACT FROM AUTHOR]

Structural inheritance of preexisting crustal discontinuities is widely accepted to have played a crucial role during the Cenozoic tectonic evolution of the northern Alpine foreland. It is recognised as a process that can strongly influence local fault kinematics and strain patterns. The case study presented herein is dedicated to the tectonic analysis of the Freiburg-Bonndorf-Bodensee Fault Zone (FBBFZ) located at the external margin of the northern Alpine Molasse Basin and extending into the crystalline Black Forest Massif. The structure and kinematics of this crustal-scale fault zone are investigated by means of a regional analysis of locally mapped faults, kinematic analysis of outcrop-scale fractures and slip vector modelling. The exceptional possibility of analysing the fault zone exposed from basement to cover allowed for an evaluation of interaction between precursory structures and subsequent deformation features. The results of this study show that the crystalline basement structures exposed along the FBBFZ had a strong imprint on the map-scale fault pattern observable in the Mesozoic and Tertiary sequences. Kinematic analysis of outcrop-scale fracture systems in the latter units yields evidence for local multi-directional extension and strike-slip faulting during Miocene to recent times. While these observations may evoke the interpretation of a multistage palaeostress history along the FBBFZ, slip vector modelling of a very well exposed FBBFZ segment suggests that the various strain records can alternatively be explained by one single regional stress tensor and be related to superordinate deep-seated strike-slip deformation. [ABSTRACT FROM AUTHOR]

Background: Unnecessary emergency department (ED) visits following bariatric surgery represent a significant source of inefficient resource utilization. This study aimed to identify potential strategies aimed at preventing unnecessary returns to the ED following bariatric surgery. The study was conducted in University Hospital, USA. Methods: The electronic medical records of all patients who underwent bariatric surgery at our institution between January 2011 and October 2015 were retrospectively reviewed. Information regarding procedure, gender, age, preoperative BMI, obesity-related comorbid conditions, postoperative length of stay (LOS), and reasons for ED visits within 90 days of surgery were obtained. Six practitioners (four attending surgeons, one resident physician, and one physician assistant) independently reviewed patient chief complaint and clinical findings at the time of ED returns. Reasons for ED return were scored as either preventable or non-preventable. 'Preventable' denoted that an ED return could potentially be avoided by means of a system change in our bariatric practice. Results: Our institution performed 361 bariatric procedures during the study period. Of these, 65 patients had 91 ED visits, 23 of which resulted in readmissions, and two of which required operative interventions. The ≤90-day all-cause postoperative ED visit rate was 18% ( n = 65). Of the 91 ED visits, 47% were deemed preventable ( n = 43). The most common preventable reasons for ED returns were nausea, vomiting, dehydration (NVD) (27.9%), postoperative pain (25.6%), wound evaluations (20.9%), and compliance issues (14%). Conclusions: Postoperative ED visits following bariatric surgery are prevalent and costly. Many of these visits are potentially preventable. Implementing outpatient strategies to address these causes will likely attenuate inefficient resource utilization. [ABSTRACT FROM AUTHOR]

Background: Non-anesthesia administered propofol (NAAP) has been shown to be a safe and effective method of sedation for patients undergoing gastrointestinal endoscopy. Bariatric surgery patients are potentially at a higher risk for sedation-related complications due to co-morbidities including obstructive sleep apnea. The outcomes of NAAP in bariatric patients have not been previously reported. Methods: In this retrospective cohort study, severely obese patients undergoing pre-surgical outpatient esophagogastroduodenoscopy (EGD) were compared to non-obese control patients (BMI ≤ 25 kg/m) undergoing diagnostic EGD at our institution from March 2011-September 2015 using our endoscopy database. Patients' demographics and procedural and recovery data, including any airway interventions, were statistically analyzed. Results: We included 130 consecutive pre-operative bariatric surgical patients with average BMI 45.8 kg/m (range 34-80) and 265 control patients with average BMI 21.9 kg/m (range 14-25). The severely obese group had a higher prevalence of sleep apnea (62 vs 8%; p < 0.001), experienced more oxygen desaturations (22 vs 7%; p < 0.001), and received more chin lift maneuvers (20 vs 6%; p < 0.001). Advanced airway interventions were rarely required in either group and were not more frequent in the bariatric group. Conclusions: With appropriate training of endoscopy personnel, NAAP is a safe method of sedation in severely obese patients undergoing outpatient upper endoscopy. [ABSTRACT FROM AUTHOR]

Background: Nonalcoholic fatty liver disease (NAFLD) is common in adults with extreme obesity and can impact long-term health and survival. Liver biopsy is the only accurate test for diagnosis and staging, but is invasive and costly. Non-invasive testing offers an attractive alternate, but the overall accuracy remains a significant issue. This study was conducted to determine the accuracy and clinical utility of pre-operative ultrasound and liver transaminase levels, as well as intra-operative hepatic visual inspection, for assessing presence of NAFLD as confirmed by hepatic histology. Methods: Data was collected prospectively from 580 morbidly obese adult patients who underwent Roux-en-Y gastric bypass surgery with intraoperative wedge biopsy between January 2004 and February 2009. Complete data for ultrasound, ALT and AST levels, and documented visual inspection was available for 513 patients. Results: The prevalence of NAFLD was 69 % and that of NASH was 32 %. The individual non-invasive clinical assessments demonstrated low sensitivity, specificity, and accuracy for detecting the presence of steatosis, steatohepatitis, or fibrosis. The combination of normal or abnormal results for all tests improved predictive utility. Abnormal tests with all three assessments had a sensitivity of 95-98 % and a specificity of 28-48 % for major histologic findings in NAFLD/NASH. Normal tests with all three assessments had a sensitivity of 12-22 % and a specificity of 89-97 % for major histologic findings in NAFLD/NASH. Conclusions: Although individual clinical tests for NAFLD have limited accuracy, the use of combined clinical tests may prove useful. [ABSTRACT FROM AUTHOR]

Challenges of specimen extraction during laparoscopic sleeve gastrectomy and other resectional laparoscopic procedures can often be proven to be time consuming and frustrating, and the risk of wound infection and port site tumor implantation increases. In this paper, we discuss our experience with an efficient approach to specimen extraction utilizing a novel technique for deployment of a very small self-expanding wound protector through a 12- or 15-mm port. We also report our observations with regard to the learning curve of this technique and the influence of BMI to retractor insertion times and specimen extraction times during laparoscopic sleeve gastrectomy. [ABSTRACT FROM AUTHOR]

Background: Anastomotic leak at the gastrojejunostomy is a life-threatening complication of laparoscopic Roux-en-Y gastric bypass (LRYGB). Fibrin sealants have been used as topical adjuncts to reduce leaks at the gastrojejunostomy. Our clinical observations suggest that an unintended consequence may be the promotion of anastomotic stricture. We hypothesized that the use of fibrin sealant at the gastrojejunostomy in patients undergoing LRYGB decreases the incidence of anastomotic leak but increases the incidence of clinically significant stricture. Methods: Following institutional review board approval, medical records of patients undergoing LRYGB by two surgeons at a single institution over a 5-year period were retrospectively reviewed. Preoperative demographics and postoperative complication rates including incidence of gastrojejunostomy leak and endoscopically diagnosed stricture requiring dilation within 1 year of surgery were recorded. Results: Four hundred twenty-five patients had fibrin sealant routinely applied to their gastrojejunostomy site and 104 did not. Four leaks occurred in the sealant group and two leaks occurred in the control group ( p = 0.2). Of patients who received sealant, 1.6 % needed postoperative blood transfusion compared to those 1.6 % of patient who did not receive sealant ( p = 0.05). There was a significantly increased rate of strictures requiring dilation in the sealant group (11.3 % compared to 4.8 % stricture rate in patients who did not receive sealant, p = 0.04). Conclusions: In our experience, the use of fibrin sealant at linear stapled gastrojejunostomy site during LRYGB increases the incidence of clinically significant postoperative stricture and does not reduce the incidence of anastomotic leak. [ABSTRACT FROM AUTHOR]

Objective:The goal of the present study was to identify differences in gene expression between SAT, VAT and EAT depots in Class III severely obese individuals.Design:Human subcutaneous (SAT) and visceral (VAT) adipose tissues exhibit differential gene expression profiles. There is little information, however, about the other proximal white adipose tissue, epigastric (EAT), in terms of its function and contribution to metabolism.Subjects and methods:Using RNA from adipose biospecimens obtained from Class III severely obese patients undergoing open Roux-en-Y gastric bypass surgery, we compared gene expression profiles between SAT, VAT and EAT, using microarrays validated by real-time quantitative PCR.Results:The three depots were found to share 1907 genes. VAT had the greatest number of genes (66) expressed exclusively in this depot, followed by SAT (23), and then EAT (14). Moreover, VAT shared more genes with EAT (65) than with SAT (38). Further analyses using ratios of SAT/EAT, VAT/EAT and SAT/VAT identified specific as well as overlapping networks and pathways of genes representing dermatological diseases, inflammation, cell cycle and growth, cancer and development. Targeted analysis of genes, having a role in adipose tissue development and function, revealed that Peroxisome proliferator-activated receptor Gamma Coactivator 1-alpha (PGC1-α) that regulates the precursor of the hormone Irisin (FNCD5) were abundantly expressed in all three fat depots, along with fibroblast growth factors (FGF) FGF1, FGF7 and FGF10, whereas, FGF19 and FGF21 were undetectable.Conclusions:These data indicate that EAT has more in common with VAT, suggesting similar metabolic potential. The human epigastric adipose depot could have a significant functional role in metabolic diseases and should be further investigated. [ABSTRACT FROM AUTHOR]

Objectives.The accumulation of lipids stored as excess triglycerides in the liver (steatosis) is highly prevalent in obesity and has been associated with several clinical characteristics, but most studies have been based on relatively small sample sizes using a limited set of variables.We sought to identify clinical factors associated with liver fat accumulation in a large cohort of patients with extreme obesity. Methods.We analyzed 2929 patients undergoing intraoperative liver biopsy during a primary bariatric surgery. Univariate and multivariate regression modeling was used to identify associations with over 200 clinical variables with the presence of any fat in the liver and with moderate to severe versus mild fat accumulation. Results. A total of 19 data elements were associated with the presence of liver fat and 11 with severity of liver fat including ALT and AST, plasma lipid, glucose, and iron metabolism variables, several medications and laboratory measures, and sleep apnea. The accuracy of a multiple logistic regression model for presence of liver fat was 81% and for severity of liver fat accumulation was 77%. Conclusions. A limited set of clinical factors can be used to model hepatic fat accumulation with moderate accuracy and may provide potential mechanistic insights in the setting of extreme obesity. [ABSTRACT FROM AUTHOR]

Background: Acute incarceration of paraesophageal hernias (PEHs) requiring urgent or emergent surgery is rare. Patients are often elderly with significant comorbidities and have historically been treated with open abdominal or thoracic incisions. Our study was designed to evaluate the feasibility, safety, and efficacy of laparoscopic paraesophageal hernia repair (LPEHR) in patients with PEH and acute gastric volvulus. Methods: We reviewed our prospectively maintained database and identified 269 patients who underwent an initial LPEHR between January 2003 and January 2012. Patients were divided into group A (acute), group B (age- and comorbidity-matched 1:3), and group C (all elective repairs). Group A included those admitted with acute symptoms related to PEH and underwent urgent repair. Patient age, Charlson score, operative time, length of stay (LOS), morbidity, mortality, and recurrence rates were compared. Results: Patients who underwent urgent LPEHR had a higher perioperative morbidity rate than the elective and matched groups. The overall mortality rate was low and no statistical difference was found between groups A, B, and C. LOS in group A was longer than groups B and C. The need for ICU admission was also higher in group A. There was no statistical difference in recurrence rates. Conclusions: Historically, patients presenting with acute symptoms related to PEH have required open repair, which is associated with significant morbidity and mortality. The acute group was older and sicker than our elective LPEHR patients and had more adverse events resulting in a longer LOS, even when compared with comorbidity-matched elective patients. However, the LOS remained shorter than that reported for open repair and there was no mortality. The recurrence rates in all groups were low and comparable to elective repairs. [ABSTRACT FROM AUTHOR]

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The use of swarms of nanobots to perform seemingly miraculous tasks is a common trope in the annals of science fiction.1 Although several of these remarkable feats are still very much in the realm of fiction, scientists have recently overcome many of the physical challenges associated with operating on the small scale and have generated the first generation of autonomous self-powered nanomotors and pumps. The motors can be directed by chemical and light gradients, pick up and deliver cargo, and exhibit collective behavior. [ABSTRACT FROM AUTHOR]

Powered by UV light, nano/micrometer-sized silver chloride particles exhibit autonomous movement and form 'schools' in aqueous solution, i.e. regions in which the number density of particles is significantly higher than the global average. In this paper, the silver chloride particles in such a system are classified by their proximity to other AgCl particles -be they isolated, coupled or schooled- and their motion paths are tracked and analyzed. By plotting time-averaged mean squared displacements of each particle over various time intervals from 0.1s to 15.0s, we discover different diffusive behaviors for the three classes of silver chloride particles. [ABSTRACT FROM AUTHOR]

The Triassic to Cretaceous sediment succession of the Lechtal Nappe in the western part of the Northern Calcareous Alps (NCA) has been deformed into large-scale folds and crosscut by thrust and extensional faults during Late Cretaceous (Eoalpine) and Tertiary orogenic processes. The following sequence of deformation is developed from overprinting relations in the field: (D1) NW-vergent folds related to thrusting; (D2) N-S shortening leading to east-west-trending folds and to the formation of a steep belt (Arlberg Steep Zone) along the southern border of the NCA; (D3) E-W to NE-SW extension and vertical shortening, leading to low-angle normal faulting and recumbent 'collapse folds' like the Wildberg Syncline. D1 and D2 are Cretaceous in age and predate the Eocene emplacement of the Austroalpine on the Penninic Nappes along the Austroalpine basal thrust; the same is probably true for D3. Finally, the basal thrust was deformed by folds related to out-of-sequence thrusting. These results suggest that the NCA were at least partly in a state of extension during the sedimentation of the Gosau Group in the Late Cretaceous. [ABSTRACT FROM AUTHOR]

Background: Gastroesophageal reflux disease (GERD) is a common comorbid condition in morbidly obese gastric bypass candidates. Unfortunately, some patients who ultimately present for bariatric surgery have previously undergone Nissen fundoplication for GERD. Many surgeons consider previous fundoplication to be a relative contraindication to subsequent laparoscopic Roux-en-Y gastric bypass (LRYGB) due to increased technical complexity and risk. We sought to compare the perioperative and long-term outcomes of a cohort of patients who had first undergone fundoplication and ultimately chose to later pursue LRYGB for morbid obesity (revision) to matched control patients. Methods: Data were obtained from our prospectively maintained bariatric surgery database. Patients who underwent laparoscopic takedown of a previous fundoplication and conversion to LRYGB were compared to control patients who underwent primary LRYGB. For every revision patient, two control subjects were randomly selected from the database after matching for preoperative body mass index and year of surgery. Results: From July 2002 to April 2011, 14 patients underwent laparoscopic takedown of a previous Nissen fundoplication and then underwent LRYGB. During the same interval, 673 patients underwent LRYGB as a primary procedure for obesity from which 28 were selected as controls. There were no conversions to open laparotomy in any patient. Subjects were similar demographically. Operating time and duration of hospital stay were significantly longer in revision patients. Complications were more frequent in revisions (36% revisions vs. 7% controls, P = 0.03). Excess weight loss 1-year after surgery was excellent in both groups and did not differ (69% revision vs. 69.6% controls, P = 0.93). Conclusions: Although associated with longer operating times, longer duration of hospital stay, and complications, LRYGB after fundoplication is feasible and safe. Long-term weight loss outcomes are similar to those seen following primary LRYGB. Previous fundoplication is not a contraindication to LRYGB. [ABSTRACT FROM AUTHOR]

A simple template-based synthesis of three-component nanorods with flexible central sections is discussed. These nanorods become flexible by dissolving their central silver sections in dilute hydrogen peroxide, to leave behind a flexible yet robust residue. It is also shown that the flexible region can be reinforced by adding a polymer additive to the plating mixture. [ABSTRACT FROM AUTHOR]

One of the more interesting recent discoveries has been the ability to design nano/microparticles which catalytically harness the chemical energy in their environments to move autonomously. These “nanomotors” can be directed by externally applied magnetic fields, or optical and chemical gradients. Our group has now developed two systems in which chemical secretions from the translating micro/nanomotors initiate long-range, collective interactions among the particles viaself-diffusiophoresis. Herein, we discuss two different approaches to model the complex emergent behavior of these particles, the first being a qualitative probability-based model with wide applicability, and the second being a more quantitative Brownian dynamics simulation specific to the self-diffusiophoretic phenomenon. [ABSTRACT FROM AUTHOR]