Developing Cheap but Useful Machine Learning-Based Models for Investigating High-Entropy Alloy Catalysts.

This work aims to address the challenge of developing interpretable ML-based models when access to large-scale computational resources is limited. Using CoMoFeNiCu high-entropy alloy catalysts as an example, we present a cost-effective workflow that synergistically combines descriptor-based approaches, machine learning-based force fields, and low-cost density functional theory (DFT) calculations to predict high-quality adsorption energies for H, N, and NHx (x = 1, 2, and 3) adsorbates. This is achieved using three specific modifications to typical DFT workflows including: (1) using a sequential optimization protocol, (2) developing a new geometry-based descriptor, and (3) repurposing the already-available low-cost DFT optimization trajectories to develop a ML-FF. Taken together, this study illustrates how cost-effective DFT calculations and appropriately designed descriptors can be used to develop cheap but useful models for predicting high-quality adsorption energies at significantly lower computational costs. We anticipate that this resource-efficient philosophy may be broadly relevant to the larger surface catalysis community.

Peristaltic transport of Sutterby nanofluid flow in an inclined tapered channel with an artificial neural network model and biomedical engineering application.

Modern energy systems are finding new applications for magnetohydrodynamic rheological bio-inspired pumping systems. The incorporation of the electrically conductive qualities of flowing liquids into the biological geometries, rheological behavior, and propulsion processes of these systems was a significant effort. Additional enhancements to transport properties are possible with the use of nanofluids. Due to their several applications in physiology and industry, including urine dynamics, chyme migration in the gastrointestinal system, and the hemodynamics of tiny blood arteries. Peristaltic processes also move spermatozoa in the human reproductive system and embryos in the uterus. The present research examines heat transport in a two-dimensional deformable channel containing magnetic viscoelastic nanofluids by considering all of these factors concurrently, which is vulnerable to peristaltic waves and hall current under ion slip and other situations. Nanofluid rheology makes use of the Sutterby fluid model, while nanoscale effects are modeled using the Buongiorno model. The current study introduces an innovative numerical computing solver utilizing a Multilayer Perceptron feed-forward back-propagation artificial neural network (ANN) with the Levenberg-Marquardt algorithm. Data were collected for testing, certifying, and training the ANN model. In order to make the dimensional PDEs dimensionless, the non-similar variables are employed and calculated by the Homotopy perturbation technique. The effects of developing parameters such as Sutterby fluid parameter, Froude number, thermophoresis, ion-slip parameter, Brownian motion, radiation, Eckert number, and Hall parameter on velocity, temperature, and concentration are demonstrated. The machine learning model chooses data, builds and trains a network, and subsequently assesses its performance using the mean square error metric. Current results declare that the improving Reynolds number tends to increase the pressure rise. Improving the Hall parameter is shown to result in a decrease in velocity. When raising a fluid's parameter, the temperature profile rises.

Pontine Infarct Presenting with Atypical Dental Pain: A Case Report.

Orofacial pain' most commonly occurs due to dental causes like caries, gingivitis or periodontitis. Other common causes of 'orofacial pain' are sinusitis, temporomandibular joint(TMJ) dysfunction, otitis externa, tension headache and migraine. In some patients, the etiology of 'orofacial pain' remains undetected despite optimal evaluation. A few patients in the practice of clinical dentistry presents with dental pain without any identifiable dental etiology. Such patients are classified under the category of 'atypical odontalgia'. 'Atypical odontalgia' is reported to be prevalent in 2.1% of the individuals. 'Atypical orofacial pain' and 'atypical odontalgia' can result from the neurological diseases like multiple sclerosis, trigeminal neuralgia and herpes infection. Trigeminal neuralgia has been frequently documented as a cause of 'atypical orofacial pain' and 'atypical odontalgia'. There are a few isolated case reports of acute pontine stroke resulting in 'atypical orofacial pain' and 'atypical odontalgia'. However, pontine stroke as a cause of atypical odontalgia is limited to only a few cases, hence prevalence is not established. This case is one, where a patient presented with acute onset atypical dental pain with no identifiable dental etiology, further diagnosed as an acute pontine infarct on neuroimaging. A 40 years old male presented with acute onset, diffuse teeth pain on right side. Dental examination was normal. Magnetic resonance imaging(MRI) of the brain had an acute infarct in right pons near the trigeminal root entry zone(REZ). Pontine infarct presenting with dental pain as a manifestation of trigeminal neuropathy, has rarely been reported previously. This stresses on the importance of neuroradiology in evaluation of atypical cases of dental pain.

Laparoscopic Roux-en-Y gastric bypass for nonobese type II diabetes mellitus in Asian patients.

BACKGROUND: The beneficial role of laparoscopic Roux-en-Y gastric bypass (LRYGB) for type 2 diabetes mellitus (T2 DM) in morbidly obese patients has been established; however, there is scant evidence supporting its effectiveness in nonobese T2 DM Asian patients. The objective of this study was to evaluate the effect of LRYGB in nonobese T2 DM patients and elucidate the predictors of DM remission after one year follow-up. METHODS: Between June 2009 and May 2011, twenty-nine nonobese (body mass index (BMI)<27 kg/m(2)) Asian patients with T2 DM who underwent LRYGB were enrolled. All patients were prospectively followed up for one year. Baseline demographic characteristics, diabetic status, and clinical and biochemical data were collected preoperatively and one year after LRYGB. DM remission was defined as those with hemoglobin A1 c (HbA1 c)<6.5% without oral hypoglycemic drugs (OHA)/insulin. Outcomes in the DM remission group were compared with the nonremission group and analyzed. RESULTS: All clinical and biochemical parameters, except uric acid, were significantly improved. DM remission was achieved in eleven patients (37.9%) of whom five (45.5%) were male. Blood glucose, HbA1 c, c-peptide, homeostatic model assessment (HOMA-%B), and low density lipoprotein (LDL)-cholesterol were the significant variables in patients with DM remission; however, multiple logistic regression showed that only preoperative HOMA-%B (odds ratio (OR) = 1.13, 95% CI = 1.03-1.24) was a predictor for DM remission. Though no mortality was seen, the complication rate was 20.7%, of which 17.3% was related to marginal ulcers. CONCLUSION: LRYGB resulted in significant clinical and biochemical improvements in nonobese Asian patients, with HOMA-%B indicating ß-cell function as the main predictor of T2 DM remission. Appropriate patient selection with better ß-cell function and evidence from long-term follow-up may justify this therapeutic approach.

Laparoscopic ventral hernia repair: defining the learning curve.

Between 2004 and June 2011, 181 patients underwent laparoscopic ventral hernia repair. Three main surgeons, all experienced in laparoscopic procedures, performed all the cases. After analyzing the operative time (OT) for 3 main surgeons, within the first 20 cases the overall performance plateaued. Data from 60 patients (50F, 10M), with a mean age of 42.3 years (range, 26 to 88 y) and a mean hernia defect size of 6.5 cm (range, 4 to 18 y), were evaluated. No significant differences were recorded among the 3 surgeons in OT and intraoperative or postoperative complications. But 3 (5%, P<0.03) patients had complications, and the recurrence rate was 6.6% with a mean follow-up of 54 months (range, 42 to 70 mo). One had prolonged postoperative ileus, the second had bowel serosal tear, and the last had port-site incarcerated hernia. Our results showed that the OT of 98.9 minutes (range, 48 to 205 min) stabilized in 12 cases.

Esthetic and functional rehabilitation of mutilated dentition and loss of vertical dimension due to amelogenesis imperfecta.

Cases of severe attrition are a common finding. Among the congenital anomalies, amelogenesis imperfecta and dentinogenesis imperfecta are important conditions that may cause accelerated wear of teeth. The following case report describes the complete oral rehabilitation of a patient diagnosed with amelogenesis imperfecta. A detailed treatment plan was chalked out which included proper oral hygiene measures, restoration of carious teeth and endodontic treatment followed by foundation restorations of teeth that were crucial for the final prostheses. Patient was given transitional restorations for about 6 weeks with the aim of regaining the lost vertical dimensions. Final rehabilitation was done by fixed dental prostheses.

Novel metabolic surgery for type II diabetes mellitus: loop duodenojejunal bypass with sleeve gastrectomy.

A total of 22 (14F/8M) patients with a mean age of 50.3 years (range, 33 to 64 y) and a mean body mass index of 28.4 kg/m (range, 21.8 to 38.3 kg/m) underwent loop duodenojejunal bypass with sleeve gastrectomy from October 2011 to March 2012. The mean duration of onset of type 2 diabetes mellitus was 8 years (range, 1 to 20 y). All patients were on oral hypoglycemic agents; 3 (14%) patients were also using insulin. The mean preoperative glycosylated hemoglobin (HbA1c), fasting plasma sugar, and C-peptide levels dropped from 8.6% (range, 7% to 13.2%), 147 mg/dL (range, 108 to 241 mg/dL), and 2.4 ng/mL (range, 0.7 to 4.1 ng/mL) to 6.2% (range, 5.1% to 9.1%), 110 mg/dL (range, 72 to 234 mg/dL), and 1.3 ng/mL (range, 0.6 to 2.8 ng/mL) at 6 months, respectively. At 6 months, 11 (50%) patients showed type 2 diabetes mellitus remission (HbA1c<6.0%), and 20 (91%) patients achieved HbA1c<7.0% without medicine. There were no intraoperative or early postoperative complications. Loop duodenojejunal bypass with sleeve gastrectomy is safe, feasible, and shows good efficacy in terms of glycemic control in this preliminary report with short follow-up.

Laparoscopic adjustable gastric banded plication: a case-matched comparative study with laparoscopic sleeve gastrectomy.

Laparoscopic sleeve gastrectomy (LSG) has been accepted as stand-alone restrictive bariatric procedure; laparoscopic adjustable gastric banded plication (LAGBP) is an innovative technique combining gastric banding and plication of the stomach. This study aims to compare LAGBP with LSG in terms of percent excess weight loss (%EWL), resolution of comorbidities, and complications. This study was conducted in a university hospital. We retrospectively analyzed data of 60 patients: 30 each receiving LSG and LAGBP between May 2009 to October 2010. Demographics, operative data, complications, % EWL, and resolution of comorbidities were analyzed and compared. All the patients were followed for at least 1 year. LSG and LAGBP were matched for age, sex, body mass index and comorbidity ratio. Mean operative time was significantly longer in LAGBP: 62.45 ± 30.1 vs. 86.01 ± 21.88 (p = 0.001). Both groups had similar complication rates (6.67 %) and most of the patients achieved significant resolution of comorbidities. The mean %EWL was statistically significant for LSG till 18 months follow-up as compared to LAGBP, but there was no difference at 2 years (p = 0.971). Mean frequency of band adjustment after LAGBP in 2 years was 1.50 ± 1.51. There was no significant difference in comorbidity resolution in both groups. LAGBP is a dual restrictive bariatric procedure offering similar results with LSG at 2 years in terms of complications, % EWL, and comorbidity resolution with potential of continual weight loss due to band.

Randomized controlled trial comparing three methods of liver retraction in laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: This study aimed to evaluate differences between three methods of liver retraction during laparoscopic Roux-en-Y Gastric bypass (LRYGB) and to compare novel liver retraction techniques with the traditional mechanical liver retractor in a randomized controlled trial. METHODS: In this study, 60 obese patients (26 males and 34 females) who underwent LRYGB between January and July 2010 were randomized to one of three groups (20 in each): group 1 (Nathanson liver retractor), group 2 (liver suspension tape), and group 3 (V-shaped liver suspension technique [V-LIST]). Data regarding demographics (age, sex, body mass index); liver function test (LFT) just before surgery; postoperative results immediately, then 18 h, 1 week, and 1 month after surgery; operative data, and visual analog scale (VAS) for pain on postoperative days (PODs) 1 and 2 were calculated and analyzed. RESULTS: The groups did not differ significantly in terms of preoperative LFT or operative data except that group 3 took significantly longer time for liver suspension than group 1 (p = 0.01) or group 2 (p = 0.03). The VAS score in group 2 was significantly lower on POD 1 than in group 1 (p = 0.04). Group 1 showed a significant rise in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) at 18 h compared with group 2 (p < 0.01 and p = 0.02, respectively) and group 3 (p < 0.01 and p = 0.01), at 1 week compared with group 2 (p = 0.04 and 0.04), and in AST levels alone during the immediate postoperative compared with group 3 (p = 0.04). CONCLUSION: The Nathanson liver retractor causes more liver dysfunction than V-LIST or the liver suspension technique and causes more postoperative pain than the liver suspension technique. Both V-LIST and liver suspension tape have a short learning curve and implications for single-port surgery.

Bariatric surgery in Singapore from 2005 to 2009.

INTRODUCTION: Obesity is a major public health concern worldwide, including Singapore. Bariatric surgery has grown in popularity to combat this situation, and innovations in this field have led to the emergence of new bariatric procedures. For the healthy growth of this specialized field of surgery, it is mandatory to audit the progress and state of bariatric surgery at regular intervals. METHODS: An e-mail questionnaire survey was conducted in all the leading hospitals of Singapore practicing bariatric surgery between 2005 and 2009. All four hospitals to which the questionnaire survey was mailed responded. The responses from these hospitals were tabulated and analyzed. RESULTS: Between 2005 and 2009, a total of 278 bariatric procedures were performed on 151 men and 127 women with a mean age of 40.34 years (range: 18-64 years) by 12 practicing surgeons. The mean body mass index was 42.25 kg/m(2) (range: 31.4-73 kg/m(2)). All the operations were performed laparoscopically. The most commonly performed procedure was adjustable gastric banding (81.65%), followed by sleeve gastrectomy (13.66%) and Roux en Y gastric bypass (3.95%). CONCLUSION: There is a flux of newer procedures in Singapore. Adjustable gastric banding, which was the only available procedure being performed in 2004, was gradually being replaced by other procedures such as sleeve gastrectomy and Roux-en-Y gastric bypass in 2009.

Controversies in single-port laparoscopic surgery.

Single-port laparoscopic surgery (SPLS) is a rapidly involving minimally invasive surgical technique. SPLS has been applied to a variety of surgical procedures, including appendectomy, cholecystectomy, colectomy, and bariatric surgery. The true advantage of SPLS over conventional laparoscopic surgery has been always a topic of debate. Here, we discuss few controversies related to SPLS, starting from nomenclature, access techniques, true technical challenges, port-site hernia, and ideal patient for SPLS.

Single-incision transumbilical (SITU) surgery after SITU laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Recently, single-incision transumbilical (SITU) laparoscopic bariatric surgery has been adopted as an alternative option for treating morbid obesity. Patients prefer SITU because it leaves minimal scarring. However, second surgery after SITU is a new challenge for surgeons. Here, we report on the safety and results for patients at a university hospital who underwent second surgery with the SITU procedure after SITU-laparoscopic Roux-en-Y gastric bypass (LRYGB). PATIENTS AND METHODS: From November 2008 to May 2011, in total, 78 morbidly obese patients underwent SITU-LRYGB. After follow-up, 7 cases required reoperation with the SITU procedure because of dilated gastrojejunostomy in 1 patient, intractable hiccups in 1 patient, gallstones in 2 patients, and internal hernia from Petersen's defect in the remaining 3 patients. SITU was repeated via the previous umbilical incision to avoid creating a new scar. Three trocars were inserted separately, and pneumoperitoneum was created. The surgical procedures were performed with straight instruments. All surgical results and complications were recorded. RESULTS: The procedure was successfully completed in all 7 patients without addition of trocars or conversion to conventional LRYGB or open procedure. Mean surgical time was 63±23 minutes. There were no intraoperative complications or postoperative wound complications noted in 3 months of follow-up. CONCLUSIONS: Second surgery can be successfully done via a single umbilical incision after SITU-LRYGB, with reasonable operative time and good recovery, without additional abdominal scarring.

Bariatric surgery in Asia in the last 5 years (2005-2009).

Obesity is a major public health concern around the world, including Asia. Bariatric surgery has grown in popularity to combat this rising trend. An e-mail questionnaire survey was sent to all the representative Asia-Pacific Metabolic and Bariatric Surgery Society (APMBSS) members of 12 leading Asian countries to provide bariatric surgery data for the last 5 years (2005-2009). The data provided by representative members were discussed at the 6th International APMBSS Congress held at Singapore between 21st and 23rd October 2010. Eleven nations except China responded. Between 2005 and 2009, a total of 6,598 bariatric procedures were performed on 2,445 men and 4,153 women with a mean age of 35.5 years (range, 18-69years) and mean BMI of 44.27 kg/m(2) (range, 31.4-73 kg/m(2)) by 155 practicing surgeons. Almost all of the operations were performed laparoscopically (99.8%). For combined years 2005-2009, the four most commonly performed procedures were laparoscopic adjustable gastric banding (LAGB, 35.9%), laparoscopic standard Roux-en-Y gastric bypass (LRYGB, 24.3%), laparoscopic sleeve gastrectomy (LSG, 19.5%), and laparoscopic mini gastric bypass (15.4%). Comparing the 5-year trend from 2004 to 2009, the absolute numbers of bariatric surgery procedures in Asia increased from 381 to 2,091, an increase of 5.5 times. LSG increased from 1% to 24.8% and LRYGB from 12% to 27.7%, a relative increase of 24.8 and 2.3 times, whereas LAGB and mini gastric bypass decreased from 44.6% to 35.6% and 41.7% to 6.7%, respectively. The absolute growth rate of bariatric surgery in Asia over the last 5 years was 449%.

Single-port access adrenalectomy: our initial experience.

BACKGROUND: After being introduced in 1992, laparoscopic adrenalectomy has been accepted as the gold standard today for benign diseases. The need is now being realized for newer innovations to further reduce the trauma of surgical access. We report our experience and outcome of the first case series of single-port access adrenalectomy by using SILS™ port. METHODS: Between June 2009 and November 2010, 6 patients with adrenal tumors underwent single-port access adrenalectomy via SILS port. The device was placed through a single 3 cm incision. The patients' demographics, adrenal mass characteristics, operative time, conversion rate, intraoperative and postoperative complications, and postoperative pain score were measured. Five patients underwent adrenalectomy by using the retroperitoneal approach and 1 by using the laparoscopic transperitoneal approach. RESULTS: Three men and 3 women with mean age 51 years (range, 37-67) underwent single-incision adrenalectomy. The mean tumor size was 3.3 cm (range, 1.5-6). Three of these cases were Conn's syndrome, and the remaining 3 were incidentaloma. No significant complications or conversions to the conventional procedure were recorded. The mean operative time was 121 minutes (range, 70-165). The mean hospital stay was 2.7 days (range, 2-4). No local recurrences or hormonal relapse have been recorded to the present with a median follow-up of 12 months (range, 3-20). CONCLUSIONS: In our short experience, single-port access adrenalectomy seems to be safe and feasible in improving the advantages of laparoscopic approach, especially in terms of cosmesis, but further randomized controlled trials are needed to evaluate the benefits of this novel approach.

Single-incision laparoscopic appendectomy: prospective case series at a single centre in Singapore.

PURPOSE: Laparoscopic appendectomy is widely accepted as a standard of care for acute appendicitis. Aim of our study is to assess the safety and feasibility of single-incision laparoscopic appendectomy (SILA) in our hospital setting. METHODS: From March to August 2010, 30 patients (21 male, 9 female) with mean age 30.4 years (range, 17 to 64 y) with clinical diagnosis of acute appendicitis underwent SILA. RESULTS: The procedure was successful in 28 of 30 patients. Mean operative time was 80.4 minutes (range, 31 to 136 min). There was no mortality or major postoperative complication. The median hospital stay was 1.9 days (range, 1 to 5 d). The mean visual analogue scale score at the time of discharge was 2.2 (range, 1 to 4). CONCLUSIONS: In our early experience, SILA is safe and feasible, with acceptable operative time, short learning curve, and good cosmetic result.

Laparoscopic transabdominal preperitoneal (TAPP) hernia repair via a single port.

INTRODUCTION: To report our initial experience and outcome of 7 cases of single port laparoscopic transabdominal preperitoneal (TAPP) hernia repair. METHODS: Between May 2009 and June 2010, 7 patients underwent single port TAPP hernia repair for inguinal hernia. The device was placed through a single 2 cm infraumbilical incision. Patients' demographics, hernia characteristics, operative time, conversion rate, intraoperative and postoperative complications, and recurrence were measured. Five patients had unilateral and 2 had bilateral hernias. RESULTS: The mean operative time was 67 minutes (range: 36 to 111 min). None of the patients required any conversion to conventional TAPP. No intraoperative and postoperative complications were recorded and no recurrences have been recorded to the present with a median follow-up of 6 months (range: 2 to 8 mo). CONCLUSIONS: Single port TAPP hernia repair is safe and feasible. Further study is needed to evaluate the benefits of this novel approach compared with the conventional laparoscopic approach.