Integrated SOAs enable energy-efficient intra-data center coherent links.

Coherent optical links are becoming increasingly attractive for intra-data center applications as data rates scale. Realizing the era of high-volume short-reach coherent links will require substantial improvements in transceiver cost and power efficiency, necessitating a reassessment of conventional architectures best-suited for longer-reach links and a review of assumptions for shorter-reach implementations. In this work, we analyze the impact of integrated semiconductor optical amplifiers (SOAs) on link performance and power consumption, and describe the optimal design spaces for low-cost and energy-efficient coherent links. Placing SOAs after the modulator provide the most energy-efficient link budget improvement, up to 6 pJ/bit for large link budgets, despite any penalties from nonlinear impairments. Increased robustness to SOA nonlinearities makes QPSK-based coherent links especially attractive, and larger supported link budgets enable the inclusion of optical switches, which could revolutionize data center networks and improve overall energy efficiency.

Patient Outcomes in Laparoscopic Appendectomy With Acute Surgical Care Model Compared to Traditional Call.

INTRODUCTION: Shift-based models for acute surgical care (ACS), where surgical emergencies are treated by a dedicated team of surgeons working shifts, without a concurrent elective practice, are becoming more common nationwide. We compared the outcomes for appendectomy, one of the most common emergency surgical procedures, between the traditional (TRAD) call and ACS model at the same institution during the same time frame. METHODS: A retrospective review of patients who underwent laparoscopic appendectomy for acute appendicitis during 2017-2018. ACS and TRAD-patient demographics, clinical presentation, operative details, and outcomes were compared using independent sample t-tests, Wilcoxon rank-sum tests and Fisher's exact or χ2 tests. Multiple exploratory regression models were constructed to examine the effects of confounding variables. RESULTS: Demographics, clinical presentation, and complication rates were similar between groups except for a longer duration of symptoms prior to arrival in the TRAD group (Δ = 0.5 d, P = 0.006). Time from admission to operating room (Δ = -1.85 h, P = 0.003), length of hospital stay (Δ = -2.0 d, P < 0.001), and total cost (Δ = $ -2477.02, P < 0.001) were significantly lower in the ACS group compared to the TRAD group. Furthermore, perforation rates were lower in ACS (8.3% versus 28.6%, P = 0.003). Differences for the outcomes remained significant even after controlling for duration of symptoms prior to arrival (P < 0.05). CONCLUSIONS: Acute appendicitis managed using the ACS shift-based model seems to be associated with reduced time to operation, hospital stay, and overall cost, with equivalent success rates, compared to TRAD.

Scalable multicast hybrid broadband-crossbar wavelength selective switch: proposal and analysis.

In this Letter, we present a new hybrid broadband-crossbar switching network that can switch multiple wavelengths on demand and can also multicast. This switch fabric is an improvement over our previous design in both switch footprint and power consumption, as it reduces the number of switching elements by approximately 50%. We compare the switch loss and crosstalk with that of a multiwavelength selective crossbar switch. We also comment on fabrication tolerance of second-order ring resonators based on experimental results of 64 second-order ring resonators, and more than 250 heaters.

2 λ switch.

We demonstrate an elastic multi-wavelength selective switch with up to two wavelength switching capability per crosspoint. We fabricated the switch in a silicon photonics foundry and demonstrated a 17 nm tuning range for ring resonators, with a mean path loss of 2.43 dB. This is a 70% reduction in path loss as compared to previous generations, and we demonstrate a high-speed pulse-amplitude-modulation-4 transmission at 111 Gbps through different paths of the switch.

Bariatric efficiency at an academic tertiary care center.

BACKGROUND: Operating room (OR) efficiency requires coordinated teamwork between the staff surgeon, anesthesia team, circulating nurse, surgical technician, and surgical trainee or assistant. Bariatric cases present unique challenges including difficult airways, challenging intravenous access, use of specialized surgical equipment, and synchronized exchange of orogastric tubes. The high contribution margin of these complex bariatric procedures rests on OR efficiency. OBJECTIVE: To compare the efficiency of bariatric surgeries performed by a single surgeon at a tertiary academic medical center with its inherent variability of OR staff to that of a private hospital with a standardized surgical team. METHODS: All laparoscopic Roux-en-Y gastric bypasses (LRYGB) performed by a single surgeon at University Hospitals Cleveland Medical Center (UHCMC) and a Community Affiliate (CA) from 2013 to 2015 were retrospectively reviewed. Patient demographics and preoperative comorbidities were compared. The variability of OR staff at each site was described. Four primary endpoints of the different OR phases were measured at the 2 locations and analyzed using standard statistical methods. RESULTS: The OR data of 74 cases of LRYGB at UHCMC and 106 cases at the CA were analyzed. Patient cohorts were comparable by age (45 ± 12 vs. 45 ± 10; p = 0.88), sex (82% vs. 79% female; p = 0.62), BMI (47.16 ± 7.33 vs. 45.91 ± 6.85; p = 0.25), and comorbidities. At CA, the teams who participated in LRYGB cases were fairly constant (8 circulating and scrub nurses, 4 anesthetists, 3 anesthesiologists), whereas at UHCMC there was great variability in the number of staff with 108 staff (39 circulating nurses, 57 scrub nurses/technicians, 59 anesthetists or anesthesia residents, 24 anesthesiologists) participated in LRYGB cases. There was no statistical difference between the total mean OR time and surgical time of the cases performed at the 2 sites (203 ± 59 min vs. 188 ± 39 min; p = 0.06; 152 ± 56 min; 145 ± 37 min; p = 0.36). However, the pre- and post-case times were longer at UHCMC compared to the CA (38 ± 9 min vs. 33 ± 6 min; p < 0.0001; 13 ± 6 min vs. 10 ± 3 min; p = 0.01). CONCLUSION: The academic center has much greater variability in staff for these complex bariatric procedures. There was a trend toward longer OR times at the tertiary center as demonstrated by the difference in pre- and post-case times, but the consistent surgeon and assistant allowed for consistent surgical case time regardless of the setting. The implication of variability in OR staff can be overcome by the surgeon directing the procedure itself. The opportunity for improving the efficiency of bariatric surgery should focus on the perioperative care of the patient in OR that requires everyone to be familiar with the procedure.

Correction to: Bariatric efficiency at an academic tertiary care center.

This article was updated to correct Adel Alhaj Saleh's name, incorrectly displayed as Adel A. Saleh. It is correct as displayed here: Adel (first name) Alhaj Saleh (last name).

Safety of Revision Sleeve Gastrectomy Compared to Roux-Y Gastric Bypass After Failed Gastric Banding: Analysis of the MBSAQIP.

OBJECTIVE: The aim of this study was to assess the safety of revisional surgery to laparoscopic sleeve gastrectomy (LSG) compared to laparoscopic Roux-Y gastric bypass (LRYGB) after failed laparoscopic adjustable gastric banding (LAGB). BACKGROUND: The number of reoperations after failed gastric banding rapidly increased in the United States during the last several years. A common approach is band removal with conversion to another weight loss procedure such as gastric bypass or sleeve gastrectomy in a single procedure. The safety profile of those procedures remains controversial. METHODS: Preoperative characteristics and 30-day outcomes from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Participant Use Files 2015 were selected for all patients who underwent a 1-stage conversion of LAGB to LSG (conv-LSG) or LRYGB (conv-LRYGB). Conv-LSG cases were matched (1:1) with conv-LRYGB patients by age (±1 year), body mass index (±1 kg/m(2)), sex, and comorbidities including diabetes, hypertension, hyperlipidemia, venous stasis, and sleep apnea. RESULTS: A total of 2708 patients (1354 matched pairs) were included in the study. The groups were closely matched as intended. The mean operative time in conv-LRYGB was significantly longer in comparison to conv-LSG patients (151 ±â€Š58 vs 113 ±â€Š45 minutes, P < 0.001). No mortality was observed in either group. Patients after conv-LRYGB had a clinically increased anastomotic leakage rate (2.07% vs 1.18%, P = 0.070) and significantly increased bleed rate (2.66% vs 0.44%, P < 0.001). Thirty-day readmission rate was significantly higher in conv-LRYGB patients (7.46% vs 3.69%, P < 0.001), as was 30-day reoperation rate (3.25% vs 1.26%, P < 0.001). The length of hospital stay was longer in conv-LRYGB. CONCLUSIONS: A single-stage conversion of failed LAGB leads to greater morbidity and higher complication rates when converted to LRYGB versus LSG in the first 30 days postoperatively. These differences are particularly notable with regards to bleed events, 30-day reoperation, 30-day readmission, operative time, and hospital stay.

Multi-wavelength selective crossbar switch.

Here we demonstrate an 8x4 multi-wavelength selective ring resonator based crossbar switch matrix implemented in a 220-nm silicon photonics foundry for interconnecting electronic packet switches in scalable data centers. This switch design can dynamically assign up to two wavelength channels for any port-port connection, providing almost full connectivity with significant reduction in latency, cost and complexity. The switch unit cell insertion loss was measured at 0.8 dB, with an out-of-band rejection of 32 dB at 400 GHz channel separation. All the ring resonator heaters were thermally tuned, with heaters controlled by a custom 64-channel DAC driver. Detailed measurements on the whole switch showed standard deviation of 2 dB in losses across different paths, standard deviation of 0.33 nm in resonant wavelength and standard deviation of 0.01 nm/mW in ring heater tuning efficiency. Data transmission experiments at 40 Gbps showed negligible penalty due to crosstalk paths through the switch.

On-chip wavelength locking for photonic switches.

We present an on-chip wavelength reference with a partial drop ring resonator and germanium photodetector. This approach can be used in ring-resonator-based wavelength-selective switches where absolute wavelength alignment is required. We use the temperature dependence of heater resistance as a temperature sensor. Additionally, we discuss locking speed, statistical variation of heater resistances, and tuning speed of the switches.

Diabetic foot ulcer mobile detection system using smart phone thermal camera: a feasibility study.

BACKGROUND: Nowadays, the whole world is being concerned with a major health problem, which is diabetes. A very common symptom of diabetes is the diabetic foot ulcer (DFU). The early detection of such foot complications can protect diabetic patients from any dangerous stages that develop later and may require foot amputation. This work aims at building a mobile thermal imaging system that can be used as an indicator for possible developing ulcers. METHODS: The proposed system consists of a thermal camera connected to a Samsung smart phone, which is used to acquire thermal images. This thermal imaging system has a simulated temperature gradient of more than 2.2 °C, which represents the temperature difference (in the literature) than can indicate a possible development of ulcers. The acquired images are processed and segmented using basic image processing techniques. The analysis and interpretation is conducted using two techniques: Otsu thresholding technique and Point-to-Point mean difference technique. RESULTS: The proposed system was implemented under MATLAB Mobile platform and thermal images were analyzed and interpreted. Four testing images (feet images) were used to test this procedure; one image with any temperature variation to the feet, and three images with skin temperature increased to more than 2.2 °C introduced at different locations. With the two techniques applied during the analysis and interpretation stage, the system was successful in identifying the location of the temperature increase. CONCLUSION: This work successfully implemented a mobile thermal imaging system that includes an automated method to identify possible ulcers in diabetic patients. This may give diabetic patients the ability for a frequent self-check of possible ulcers. Although this work was implemented in simulated conditions, it provides the necessary feasibility to be further developed and tested in a clinical environment.

Improved Outcomes in Treating Acute Biliary Disorders With a Shift-Based Acute Care Surgery Model.

BACKGROUND: As Acute Care Surgery and shift-based models increase in popularity, there is evidence of better outcomes for many types of emergency general surgery patients. We explored the difference in outcomes for patients with acute biliary disorders, treated by either Acute Care Surgery (ACS) model or traditional call model (TRAD) during the same period. METHODS: Retrospective review of patients undergoing laparoscopic cholecystectomy for acute biliary disease 2017-2018. Demographics, clinical presentation, operative details, and outcomes were compared. RESULTS: Demographics, clinical presentation, and complication rates were similar between groups. Time from surgical consult to operating room (Δ = -15.34 hours [-24.57, -6.12], P = .001), length of stay (Δ = -1.4 days [-2.45, -.35], P = .009), and total charges were significantly decreased in ACS group compared to TRAD (Δ$2797.76 [-4883.12, -712.41], P = .009). CONCLUSIONS: Acute biliary disease can be managed successfully in an ACS shift-based model with reduced overall hospital charges and equivalent outcomes.

Community-Based Interventions for the Treatment and Management of Conflict-Related Trauma in Low-Middle Income, Conflict-Affected Countries: a Realist Review.

Where low- and middle-income countries have limited economic resources to provide individualized mental health services to people exposed to conflict, community-based interventions may be more appropriate. We aimed to evaluate community level interventions for improving mental health outcomes in Low- and Middle-income countries (LMIC). A realist review of community-based interventions (CBIs) to improve mental health for people in LMIC following conflict. Five databases (Cochrane, PubMed, PsychINFO, Medline, and CINAHL) and a manual search of individual papers. We found 1318 articles, of which 29 were selected. Out of the 29 primary articles, 19 showed successful results, 4 showed mixed results, 1 showed inconclusive results, and 1 showed unsuccessful results. After analyzing the results, we found 3 mechanisms that may influence the effectiveness of these CBIs: the use of lay community members as intervention deliverers, the application of transdiagnostic approaches, and customized outcome assessment tools. Community-based approaches to improve mental health in LMICs are rare and evidence for their effectiveness is limited. Interventions that have a wide scope, train lay mental health workers, and use contextually adapted outcome assessment tools show promise.

Variations in insulin requirements can be an early indicator of sepsis in burn patients.

INTRODUCTION: A >25% increase in daily insulin dosing is suggestive of possible sepsis in burn patients, however, no conclusive evidence is available regarding the time point at which insulin dosing begins to increase. The purpose of this study is to determine the exact time point at which the insulin requirement increases among non-diabetic burn patients with sepsis. METHODS: A retrospective chart review in non-diabetic burn patients with ≥20% total body surface area burned (TBSA) during 2010-2018 who received a blood culture for suspected sepsis. Absolute insulin dosing at intervals (0, 24, 48, 72, and 96 h prior to blood culture) were Box-Cox transformed and compared vs.-96 h reference using mixed-effects models accounting for within-patient dependencies. RESULTS: Fifty-eight patients (84% males, age 44 ± 17 years, TBSA% 49 ± 17.5) were included. When cube root of daily insulin dosing was regressed on each time point in a mixed-effects model, statistically significant increase in insulin dosing compared to baseline was observed for -48 (p = 0.018), -24 (p = 0.011), and 0 h (p = 0.008). CONCLUSION: Daily insulin dosing increases 48 h prior to development of other clinical signs of sepsis and can be used as a sensitive early marker.

Comparing outcomes between patients transferred from a critical access hospital versus directly from scene to a level 1 trauma center.

OBJECTIVES: The aim of this retrospective study was to compare the outcomes of trauma patients directly transported to a level I trauma center (SCENE) versus those who were stabilized at a critical access hospital (CAH) and subsequently transferred. METHODS: Patients were grouped based on their transfer status, interventions performed at CAH and outcomes. Google Maps was used to calculate the distances from the location of injury (LOI). Each transfer group data was analyzed separately to examine associations of different factors on the outcomes. Outcomes were compared using univariate and multivariate analyses and propensity score matching analysis. RESULTS: There were 262 patients in SCENE and 684 in CAH. Compared to SCENE, CAH had higher rates of blunt injury and a greater distance from LOI, whereas lower ISS score and length of stay (LOS) (p < 0.05). The majority of CAH group survived compared to SCENE (p = 0.007). For both groups, baseline factors (e.g., age) were associated with outcomes (p < 0.05). Interestingly, longer LOS in the CAH was associated with an increase in survival (p = 0.009), whereas an increased number of CT/MRI performed was associated with increased LOS (p < 0.05)., and an increased number of procedures was associated with longer LOS and ICU stay (p < 0.05). After matching, the two groups had no significant differences in survival, LOS, or ICU stay (p > 0.05). CONCLUSION: Equivalent overall clinical outcomes were seen in both groups, suggesting that existing trauma system protocols in the West Texas region are functioning well to select appropriate patients for each transfer modality. LEVEL OF EVIDENCE III: Retrospective Analysis.

Empiric antifungals do not decrease the risk for organ space infection in patients with perforated peptic ulcer.

INTRODUCTION: Infection control in patients with perforated peptic ulcers (PPU) commonly includes empiric antifungals (AF). We investigated the variation in the use of empiric AF and explored the association between their use and the subsequent development of organ space infection (OSI). METHODS: This was a secondary analysis of a multicenter, case-control study of patients treated for PPU at nine institutions between 2011 and 2018. Microbiology and utilization of empiric AF, defined as AF administered within 24 hours from the index surgery, were recorded. Patients who received empiric AF were compared with those who did not. The primary outcome was OSI and secondary outcome was OSI with growth of Candida spp. A logistic regression was used to adjust for differences between the two cohorts. RESULTS: A total of 554 patients underwent a surgical procedure for PPU and had available timing of AF administration. The median age was 57 years and 61% were male. Laparoscopy was used in 24% and omental patch was the most common procedure performed (78%). Overall, 239 (43%) received empiric AF. There was a large variation in the use of empiric AF among participating centers, ranging from 25% to 68%. The overall incidence of OSI was 14% (77/554) and was similar for patients who did or did not receive empiric AF. The adjusted OR for development of OSI for patients who received empiric AF was 1.04 (95% CI 0.64 to 1.70), adjusted p=0.86. The overall incidence of OSI with growth of Candida spp was 5% and was similar for both groups (adjusted OR 1.29, 95% CI 0.59 to 2.84, adjusted p=0.53). CONCLUSION: For patients undergoing surgery for PPU, the use of empiric AF did not yield any significant clinical advantage in preventing OSI, even those due to Candida spp. Use of empiric AF in this setting is unnecessary. STUDY TYPE: Original article, case series. LEVEL OF EVIDENCE: III.

Association between radiotherapy and obstructive sleep apnea in head and neck cancer patients: A systematic review and meta-analysis.

OBJECTIVE: Our aim was to investigate association between OSA and radiotherapy in head and neck cancer patients. METHODS: On 9th of September 2018, we have searched 12 electronic databases to retrieve relevant studies. All eligible studies that assessed association between OSA and radiotherapy in head and neck cancer patients were included in our meta-analysis. Quality assessment of included studies was done using the NIH tools for cohort, cross-sectional and case series studies. RESULTS: Fourteen studies met our study selection criteria, and six studies were eligible for our meta-analysis. There was no significant association between occurrence of OSA and radiotherapy in head and neck cancer patients (Odds ratio 1.54, 95% CI [0.66-3.60]; P  =  0.322). CONCLUSION: These findings point to no significant association between OSA risk and radiotherapy in head and neck cancer patients. We suggest more studies to be conducted to investigate any confounders that may influence the effect of radiotherapy on development of OSA in head and neck cancer patients.

In-hospital perforation risk in acute appendicitis: Age matters.

BACKGROUND: Controversy exists regarding how quickly an adult with appendicitis requires surgery to prevent perforation, and recent literature on antibiotic use as definitive treatment has complicated this question further. Since perforation is associated with worse outcomes, particularly in the elderly, efforts to prevent this complication are warranted. We studied risk factors for in-hospital perforation in patients diagnosed by admission CT with non-perforated acute appendicitis. METHODS: We evaluated baseline demographics, symptom duration, and time from admission to antibiotics and surgery. Outcome measure was perforation diagnosed intra-operatively by attending surgeon. RESULTS: Of 700 patients, 84 (12%) sustained in-hospital perforation; time from admission to operation or antibiotics were not associated. Duration of symptoms >24 h (aOR = 2.23, 95% CI = 1.33-3.72, p < 0.001) increased perforation risk. Patient age over 46 years (aOR = 4.54, 95% CI = 2.04-10.06, p < 0.001) was also associated with higher risk that increased with increasing age. CONCLUSION: Time to operation and antibiotic timing were not associated with in-hospital perforation in a general adult population. However, these findings suggest a possible benefit to expedient surgery in older patients.

Surgical management of advanced hidradenitis suppurativa via a one-stage procedure: A single-center experience.

BACKGROUND: Hidradenitis suppurativa (HS) is a debilitating skin condition; in severe forms it requires excision and skin grafting for cure. This is commonly performed as a multi-stage procedure; we explored single-stage operation as a more efficient alternative. METHODS: Retrospective review 2007-2018 evaluating outcomes of patients undergoing single-stage surgery. RESULTS: 139 one-stage procedures were performed: 35 excision and primary closure, 104 split-thickness skin grafting (STSG). Success rate was higher for STSG at 75% versus 60% with primary closure. Of failed primary closures, 57% required revision by grafting due to recurrence. Axilla procedures were most successful at 91% compared to 70%, 54%, and 50% for inguinal, gluteal, and perineal areas, respectively. Infection was the most common complication (17%), with 38% requiring readmission. CONCLUSION: Compared to prior literature on multi-stage HS treatment, one-stage operations are a feasible, cost-effective alternative. STSG should remain the procedure of choice, even when primary closure appears feasible.

Actions of annatto-extracted tocotrienol supplementation on obese postmenopausal women: study protocol for a double-blinded, placebo-controlled, randomised trial.

INTRODUCTION: Obesity is a major health concern in postmenopausal women, and chronic low-grade inflammation contributes to the development of obesity. Cellular studies and high-fat-diet-induced obese mouse model mimicking obesity show the antiobesity effect of annatto-extracted tocotrienols (TT) with antioxidant capability. We aim to assess the safety and efficacy of TT consumption for lipid-related parameters in obese postmenopausal women. METHODS AND ANALYSIS: Eligible obese postmenopausal women will be randomly assigned to placebo group (430 mg olive oil) and TT group (DeltaGold Tocotrienol 70%) for 24 weeks. In the present study, the primary outcome is total/regional fat mass and visceral adipose tissue. The secondary outcomes include lipid profile in serum, mRNA expression of fatty acid synthase and carnitine palmitoyltransferase 1A in fat tissue, oxylipins and endocannabinoids in plasma and adipose tissue, abundance and composition of intestinal microbiome in faeces, high-sensitivity C-reactive protein (hs-CRP) in serum and leptin in serum. Every participant will be evaluated at 0 (prior to starting intervention) and 24 weeks of intervention, except for serum lipid profile and hs-CRP at 0, 12 and 24 weeks. 'Intent-to-treat' principle is employed for data analysis. Hierarchical linear modelling is used to estimate the effects of dietary TT supplementation while properly accounting for dependency of data and identified covariates. To our knowledge, this is the first randomised, placebo-controlled, double-blinded study to determine dietary TT supplementation on an obese population. If successful, this study will guide the future efficacy TT interventions and TT can be implemented as an alternative for obese population in antiobesity management. ETHICS AND DISSEMINATION: This study has been approved by the Bioethics Committee of the Texas Tech University Health Sciences Center, Lubbock. An informed consent form will be signed by a participant before enrolling in the study. The results from this trial will be actively disseminated through academic conference presentation and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03705845.

Setting realistic expectations for weight loss after laparoscopic sleeve gastrectomy.

INTRODUCTION: Despite the clinical benefits of bariatric surgery, some patients have experienced disappointment with their weight loss. Setting realistic expectations is the key to success. AIM: To develop a specific prediction calculator to estimate the expected body mass index (BMI) at 1 year after laparoscopic sleeve gastrectomy (LSG). MATERIAL AND METHODS: A retrospective analysis was performed to study 211 patients after primary LSG. Nine baseline variables were analyzed. Least angle regression (LARS) was employed for variable selection and to build the predictive model. External validation was performed on a dataset of 184 patients. To test the accuracy of the model, a Wilcoxon signed-rank test was performed between BMI estimates and the observed BMI. A linear logistic equation was used to construct the online predictive calculator. RESULTS: The model included three variables - preoperative BMI (ß = 0.023, p < 0.001), age (ß = 0.005, p < 0.001), and female gender (ß = 0.116, p = 0.001) - and demonstrated good discrimination (R2 = 0.672; adjusted R2 = 0.664) and good accuracy (root mean squared error of estimate, RMSE = 0.124). The difference between the observed BMI and the estimated BMI was not statistically significant (median = 0.737 (-2.676, 3.254); p = 0.223). External validation confirmed good performance of the model. CONCLUSIONS: The study revealed a useful predictive model for estimating BMI at 1 year after LSG. The model was used for development of the PREDICT BMI calculator. This tool allows one to set realistic expectations of weight loss at one year after LSG.