How to do laparoscopic repair of perforated anterior duodenal ulcers: a 'three arches' falciform patch technique simplifies the approach.

Laparoscopic repair of perforated duodenal ulcers has proven superior results to open procedures though uptake has been poor. We describe the 'three arches' technique as a means of reducing technical difficulty and improving operative efficiency. Our case series of patients undergoing this technique for perforated peptic ulcer disease demonstrates comparable results to other methods of repair.

Impacts of Groundwater Pumping for Hydraulic Fracturing on Aquifers Overlying the Eagle Ford Shale.

Hydraulic fracturing (HF) events consume high volumes of water over a short time. When groundwater is the source, the additional pumping by rig/frack supply wells (RFSWs) may impose costs on owners of other sector wells (OSWs) by lowering the hydraulic head. The Carrizo-Wilcox aquifer in south Texas is the main source of water for HF of the Eagle Ford Shale (EFS) Play. The objectives are to assess the impacts of groundwater pumping for HF supply on: (1) hydraulic heads in OSWs located nearby an RFSW and (2) volumetric fluxes between layers of the regional aquifer system compared to a baseline model without the effect of RFSW pumping. The study area spans the footprint of the EFS Play in Texas and extends from 2011 to 2020. The pumping schedules of 2500 RFSWs were estimated from reported pumped water volumes to supply 22,500 HF events. Median annual drawdowns in OSWs ranged from 0.2 to 6.6 m, whereas 95th percentile annual drawdowns exceeded 20 m. The magnitudes of drawdown increased from 2011 to 2020. Of the four layers that comprise the Carrizo-Wilcox aquifer, the upper Wilcox was the most intensively pumped for HF supply. During the peak HF year of 2014, the net flux to the upper Wilcox was 292 Mm3 compared to the baseline net flux for the same year of 278 Mm3 -a relative gain of 14 Mm3 . Pumping for HF supply has the potential to negatively impact nearby OSWs by capturing water from adjacent aquifer layers.

Impacts of hydraulic fracturing wastewater from oil and gas industries on drinking water: Quantification of 69 disinfection by-products and calculated toxicity.

Oil and gas production generates large amounts of brine wastewater called "produced water" with various geogenic and synthetic contaminants. These brines are generally used in hydraulic fracturing operations to stimulate production. They are characterized by elevated halide levels, particularly geogenic bromide and iodide. Such salt concentrations in produced water may be as high as thousands of mg/L of bromide and tens of mg/L of iodide. Large volumes of produced water are stored, transported, reused in production operations, and ultimately disposed of by deep well injection into saline aquifers. Improper disposal may potentially contaminate shallow freshwater aquifers and impact drinking water sources. Because conventional produced water treatment typically does not remove halides, produced water contamination of groundwater aquifers may cause the formation of brominated and iodinated disinfection by-products (I-DBPs) at municipal water treatment plants. These compounds are of interest because of their higher toxicity relative to their chlorinated counterparts. This study reports a comprehensive analysis of 69 regulated and priority unregulated DBPs in simulated drinking waters fortified with 1 % (v/v) oil and gas wastewater. Impacted waters produced 1.3×-5× higher levels of total DBPs compared to river water after chlorination and chloramination. Individual DBP levels ranged from (<0.1-122 µg/L). Overall, chlorinated waters formed highest levels, including trihalomethanes that would exceed the U.S. EPA regulatory limit of 80 µg/L. Chloraminated waters had more I-DBP formation and highest levels of haloacetamides (23 µg/L) in impacted water. Calculated cytotoxicity and genotoxicity were higher for impacted waters treated with chlorine and chloramine than corresponding treated river waters. Chloraminated impacted waters had the highest calculated cytotoxicity, likely due to higher levels of more toxic I-DBPs and haloacetamides. These findings demonstrate that oil and gas wastewater if discharged to surface waters could adversely impact downstream drinking water supplies and potentially affect public health.

Full and Partial Mid-substance ACL Rupture Using Mechanical Tibial Displacement in Male and Female Mice.

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament. Surgical reconstruction is the gold standard treatment for ACL ruptures, but 20-50% of patients develop post-traumatic osteoarthritis (PTOA). ACL rupture is thus a well-recognized etiology of PTOA; however, little is known about the initial relationship between ligamentous injury and subsequent PTOA. The goals of this project were to: (1) develop both partial and full models of mid-substance ACL rupture in male and female mice using non-invasive mechanical methods by means of tibial displacement; and (2) to characterize early PTOA changes in the full ACL rupture model. A custom material testing system was utilized to induce either partial or full ACL rupture by means of tibial displacement at 1.6 or 2.0 mm, respectively. Mice were euthanized either (i) immediately post-injury to determine rupture success rates or (ii) 14 days post-injury to evaluate early PTOA progression following full ACL rupture. Our models demonstrated high efficacy in inciting either full or partial ACL rupture in male and female mice within the mid-substance of the ACL. These tools can be utilized for preclinical testing of potential therapeutics and to further our understanding of PTOA following ACL rupture.

Prospective multicentre randomised controlled trial of the effect of Braun Enteroenterostomy in the Reconstruction after Pancreaticoduodenectomy on delayed gastric emptying (DGE): protocol for the BERP study.

INTRODUCTION: Despite advances in achieving low mortality rates with pancreaticoduodenectomy (PD), morbidity remains high. A key contributor to this morbidity is delayed gastric emptying (DGE) occurring with an incidence of up to 30%. The utility of a Braun enteroenterostomy (BE) appears promising to reducing the incidence of DGE, but current research is not definitive. METHODS AND ANALYSIS: This project will be designed as a prospective multicentre randomised controlled blinded study to assess how BE effects the rate of DGE after PD in the setting of malignancy, within Australia-with blinding of patients, outcome assessors and data analysts. Patients will be randomly assigned to PD with Billroth II reconstruction with BE versus PD with Billroth II reconstruction without BE. The primary outcome is the incidence of DGE as defined by the International Study Group of Pancreatic Surgery. Secondary outcomes will include length of hospital stay, postoperative pancreatic fistula incidence, development of major complications (Clavien-Dindo≥3 a), quality of life and 90-day mortality.The study will be powered at 80% to detect a reduction in DGE rate from 30% to 15%, requiring a total of 264 study participants. An interim analysis will be performed once a total of 104 study participants have been recruited at which point the study will be able to detect reduction in DGE from 30% to 10% with 80% power. Statistical analysis will be done with intention-to-treat principles. The proportion of patients suffering DGE will be compared between treatment arms using a χ2 test, with p values used to represent statistical significance. ETHICS AND DISSEMINATION: The study has been ethically approved by the Hunter New England Human Research Ethics Committee (2021/ETH11939), with results disseminated through presentation and publication. TRIAL REGISTRATION NUMBER: CTRN12622000048785.

Reclaimed and Up-Cycled Cathodes for Lithium-Ion Batteries.

As electric vehicles become more widely used, there is a higher demand for lithium-ion batteries (LIBs) and hence a greater incentive to find better ways to recycle these at their end-of-life (EOL). This work focuses on the process of reclamation and re-use of cathode material from LIBs. Black mass containing mixed LiMn2O4 and Ni0.8Co0.15Al0.05O2 from a Nissan Leaf pouch cell are recovered via two different recycling routes, shredding or disassembly. The waste material stream purity is compared for both processes, less aluminium and copper impurities are present in the disassembled waste stream. The reclaimed black mass is further treated to reclaim the transition metals in a salt solution, Ni, Mn, Co ratios are adjusted in order to synthesize an upcycled cathode, LiNi0.6Mn0.2Co0.2O2 via a co-precipitation method. The two reclamation processes (disassembly and shredding) are evaluated based on the purity of the reclaimed material, the performance of the remanufactured cell, and the energy required for the complete process. The electrochemical performance of recycled material is comparable to that of as-manufactured cathode material, indicating no detrimental effect of purified recycled transition metal content. This research represents an important step toward scalable approaches to the recycling of EOL cathode material in LIBs.

Gallbladder volvulus: An unexpected "twist".

Gallbladder volvulus is a rare entity. It has been attributed to an elongated gallbladder mesentery, predisposing the gallbladder to twisting, obstructing the cystic duct and vessels, thus leading to ischemia and gangrene. Preoperative diagnosis can be elusive, but radiological features across multiple modalities have been described in the literature. We report a case of gallbladder volvulus in which the gallbladder appeared to be left-sided based on imaging, and present the radiological findings in keeping with a volvulus. Unlike cholecystitis, the treatment for volvulus is prompt detorsion and cholecystectomy; thus, accurate and timely diagnosis is paramount.

Pharmacological prevention of post-operative pancreatitis: systematic review and meta-analysis of randomized controlled trials on animal studies.

BACKGROUND: Postoperative pancreatic fistula (POPF) remains a significant complication of pancreatic resection with recent evidence showing a strong association between post-operative pancreatitis and subsequent development of POPF. Incidence and severity of pancreatitis following endoscopic therapy has been effectively reduced with indomethacin prophylaxis, however further agents require evaluation. We present a systematic literature review and meta-analysis of the prophylactic treatment with corticosteroids or n-acetyl cysteine (NAC) of induced pancreatitis in rodent models. METHODS: A systematic literature search was conducted using Pubmed, Medline, Embase and Cochrane library to identify eligible randomized control trials (RCT) involving animal models that examined NAC or corticosteroids. The primary outcome was the subsequent effect on serum amylase and IL-6 and the histopathological markers of severity such as pancreatic oedema and necrosis. RESULTS: Four RCTs (n = 178) met inclusion criteria examining NAC and eight RCTs (n = 546) examining corticosteroid agents (dexamethasone, hydrocortisone, methylprednisolone). Prophylactic administration of all corticosteroid agents showed a net effect in favour of reducing markers of severity of pancreatitis. NAC showed a significant reduction in severity of amylase and necrosis. CONCLUSION: The RCTs examined suggest that prophylactic administration of corticosteroid agents and NAC can reduce the severity of pancreatitis as indicated by histopathologic markers, serum amylase and IL-6 levels.

Prior Exposure to Coxsackievirus A21 Does Not Mitigate Oncolytic Therapeutic Efficacy.

Oncolytic viruses (OVs) are being developed as a type of immunotherapy and have demonstrated durable tumor responses and clinical efficacy. One such OV, Coxsackievirus A21 (CVA21), exhibited therapeutic efficacy in early phase clinical trials, demonstrating the ability to infect and kill cancer cells and stimulate anti-tumor immune responses. However, one of the major concerns in using this common cold virus as a therapeutic is the potential for innate and adaptive immune responses to mitigate the benefits of viral infection, particularly in individuals that have been exposed to coxsackievirus prior to treatment. In this study, we assess melanoma responses to CVA21 in the absence or presence of prior exposure to the virus. Melanomas were transplanted into naïve or CVA21-immunized C57BL6 mice and the mice were treated with intratumoral (IT) CVA21. We find that prior exposure to CVA21 does not dramatically affect tumor responses, nor does it alter overall survival. Our results suggest that prior exposure to coxsackievirus is not a critical determinant of patient selection for IT CVA21 interventions.

Hydrothermal Synthesis of Iridium-Substituted NaTaO3 Perovskites.

Iridium-containing NaTaO3 is produced using a one-step hydrothermal crystallisation from Ta2O5 and IrCl3 in an aqueous solution of 10 M NaOH in 40 vol% H2O2 heated at 240 °C. Although a nominal replacement of 50% of Ta by Ir was attempted, the amount of Ir included in the perovskite oxide was only up to 15 mol%. The materials are formed as crystalline powders comprising cube-shaped crystallites around 100 nm in edge length, as seen by scanning transmission electron microscopy. Energy dispersive X-ray mapping shows an even dispersion of Ir through the crystallites. Profile fitting of powder X-ray diffraction (XRD) shows expanded unit cell volumes (orthorhombic space group Pbnm) compared to the parent NaTaO3, while XANES spectroscopy at the Ir LIII-edge reveals that the highest Ir-content materials contain Ir4+. The inclusion of Ir4+ into the perovskite by replacement of Ta5+ implies the presence of charge-balancing defects and upon heat treatment the iridium is extruded from the perovskite at around 600 °C in air, with the presence of metallic iridium seen by in situ powder XRD. The highest Ir-content material was loaded with Pt and examined for photocatalytic evolution of H2 from aqueous methanol. Compared to the parent NaTaO3, the Ir-substituted material shows a more than ten-fold enhancement of hydrogen yield with a significant proportion ascribed to visible light absorption.

Spontaneous fistulisation of the common bile duct after transection by gunshot.

A 35-year-old man presented with a gunshot wound to his abdomen via his lower chest. Initial laparotomy did not identify any perforation or contamination. On day 3, a laparotomy under the hepatobiliary service discovered a gastric perforation, two lateral duodenal perforations and a complete transection of the common bile duct, presumably delayed perforation from the shockwave injury produced by the bullet. Contamination and haemodynamic instability precluded immediate reconstruction, and abdominal drains and external biliary drainage were established. High-volume duodenal fistula was managed with slow withdrawal of drains, and inadvertent dislodgement of the biliary drain in an outpatient setting resulted in spontaneous fistulisation of the bile duct to the lateral duodenal wall, with creation of a neo-bile duct. The patient remains well more than 1 year later, without external drainage despite no surgical reconstruction.

Incidence of Pediatric Eosinophilic Esophagitis and Characterization of the Stricturing Phenotype in Alberta, Canada.

Limited work has been done to characterize the stricturing pediatric eosinophilic esophagitis (EoE) phenotype. We aimed to determine, in pediatric EoE: the local incidence, the frequency of esophageal stricturing, and the safety of mechanical dilations. Methods: We retrospectively identified all new cases of EoE at our center from 2015 to 2018 using esophageal biopsy reports, EoE clinic lists, and a local OR database of esophageal dilatations. Electronic medical records (EMRs) were reviewed to confirm EoE diagnosis. Clinical data were captured from the outpatient EMR and gastroscopy/pathology reports. Scope adverse event data were captured from multiple sources. The 2016 census data were used to calculate incidence rates. Results: One hundred eighty-five new cases of EoE were diagnosed during the study period. For patients <15 years old living in Edmonton, the incidence over the 4 years was 11.1 cases per 100,000 person years. Eight of 185 (4%) patients had endoscopically confirmed esophageal strictures, 4 of which required mechanical dilation. Eleven of 185 (5.9%) patients had more subtle signs of esophageal narrowing, but no focal strictures. No perforations or episodes of significant bleeding were reported. Pain was reported after 15% of all scopes, including 50% of the 28 scopes with focal strictures. No unexpected admissions or emergency department visits occurred within 72 hours of a gastroscope with esophageal narrowing. Conclusions: Edmonton zone has one of the highest incidences of pediatric EoE reported. In this cohort, 4% had focal esophageal strictures, and 6% had more subtle narrowing. Mechanical dilation of esophageal strictures was associated with no significant adverse events.

AMY1 Gene Copy Number Correlates With Glucose Absorption and Visceral Fat Volume, but Not with Insulin Resistance.

BACKGROUND: The human amylase gene (AMY1) has a broad copy number (CN) variation that may associate with body mass index. METHODS: Deoxyribonucleic acid was extracted from urine (n = 74) and serum (n = 6) samples (Protein, Fiber and Metabolic Syndrome [ProFiMet] cohort), and buccal (n = 17) samples (Oral Starch Challenge [OSC] cohort), and assessed for AMY1 CN by droplet digital polymerase chain reaction. The association of AMY1 CN with comprehensive markers of metabolic status (ProFiMet cohort) were analyzed with Pearson's correlation coefficient (CC). For the healthy, euglycemic OSC cohort, glycemic response to OSC was analyzed with independent sample t-tests (subgroups: high AMY1 CN 9-12, n = 10; low AMY1 CN 4-6, n = 7). RESULTS: There were significant inverse correlations of AMY1 CN with total visceral fat volume (CC -0.33; P = 0.004) and positive correlations of AMY1 CN with oral glucose insulin sensitivity score (derived from an oral glucose tolerance test, CC 0.26; P = 0.02), serum HDL-cholesterol (CC 0.325; P = 0.003), and serum adiponectin (CC 0.249; P = 0.026). Linear regression multivariate analysis (adiponectin as dependent variable), showed independent association of adiponectin with AMY1 CN (Beta = 0.29; P = 0.03). There were no significant associations between AMY1 CN and clamp-derived M-value, homeostasis model assessment of insulin resistance (IR), hepatic endogenous glucose production, fecal floral signature, or macronutrient dietary preference. Delta (mean) change in blood glucose concentration (fasting to 30-minutes post-OSC) was significantly greater in the high versus low AMY1 CN subgroups (mean 1.7 mmol/l [SEM 0.6] vs 0.9 mmol/l [SEM 0.9], respectively; P = 0.016). CONCLUSIONS: High AMY1 CN associates with a favorable metabolic profile (lower visceral fat volume, higher serum adiponectin, enhanced glucose absorption following oral glucose, and OSC), but not with whole-body or hepatic IR.

RNA Imaging with RNase-Inactivated Csy4 in Plants and Filamentous Fungi.

Subcellular localizations of RNAs can be imaged in vivo with genetically encoded reporters consisting of a sequence-specific RNA-binding protein (RBP) fused to a fluorescent protein. Several such reporter systems have been described based on RBPs that recognize RNA stem-loops. Here we describe RNA tagging for imaging with an inactive mutant of the bacterial endonuclease Csy4, which has a significantly higher affinity for its cognate stem-loop than alternative systems. This property allows for sensitive imaging with only few tandem copies of the target stem-loop inserted into the RNA of interest.

High-Resolution Mass Spectrometry Identification of Novel Surfactant-Derived Sulfur-Containing Disinfection Byproducts from Gas Extraction Wastewater.

Introduction of oil and gas extraction wastewaters (OGWs) to surface water leads to elevated halide levels from geogenic bromide and iodide, as well as enhanced formation of brominated and iodinated disinfection byproducts (DBPs) when treated. OGWs contain high levels of chemical additives used to optimize extraction activities, such as surfactants, which have the potential to serve as organic DBP precursors in OGW-impacted water sources. We report the first identification of olefin sulfonate surfactant-derived DBPs from laboratory-disinfected gas extraction wastewater. Over 300 sulfur-containing DBPs, with 43 unique molecular formulas, were found by high-resolution mass spectrometry, following bench-scale chlor(am)ination. DBPs consisted of mostly brominated species, including bromohydrin sulfonates, dihalo-bromosulfonates, and bromosultone sulfonates, with chlorinated/iodinated analogues formed to a lesser extent. Disinfection of a commercial C12-olefin sulfonate surfactant mixture revealed dodecene sulfonate as a likely precursor for most detected DBPs; disulfur-containing DBPs, like bromosultone sulfonate and bromohydrin disulfonate, originated from olefin disulfonate species, present as side-products of olefin sulfonate production. Disinfection of wastewaters increased mammalian cytotoxicity several orders of magnitude, with chloraminated water being more toxic. This finding is important to OGW-impacted source waters because drinking water plants with high-bromide source waters may switch to chloramination to meet DBP regulations.

In situ XAFS of acid-resilient iridate pyrochlore oxygen evolution electrocatalysts under operating conditions.

Pyrochlore iridates (Na,Ca)2-xIr2O6·H2O are acid-stable electrocatalysts that are candidates for use in electrolysers and fuel cells. Ir LIII-edge X-ray absorption fine structure spectroscopy in 1 M H2SO4 at oxygen evolution conditions suggests the involvement of the electrons from the conduction band of the metallic particles, rather than just surface iridium reacting.

The Association Between Caesarean Section and Inflammatory Bowel Disease in Childhood and Young Adulthood: Findings From 2 Retrospective Cohort Studies.

OBJECTIVE: The aim of the study was to examine the association of Caesarean section (CS) with inflammatory bowel disease (IBD) in Nova Scotian children. METHODS: The study consisted of 2 retrospective cohorts in the Canadian province of Nova Scotia: all births between 1988 and 2014 (n = 262,729) linked with a clinical registry of all children diagnosed with IBD at the IWK Health Centre, Halifax (Clinical Cohort) and all births from 1989 to 1993 (n = 42,999) linked with provincial administrative health data (Administrative Cohort). The primary outcome was a diagnosis of IBD; the outcome in the Administrative Cohort was ascertained using a previously validated algorithm. Information on the exposures and confounding variables was obtained from the Nova Scotia Atlee Perinatal Database. The association between CS and time to diagnosis of IBD was examined using survival analysis. RESULTS: The population incidence of IBD in the Clinical and Administrative Cohort were 13.0 and 20.6, respectively, per 100,000 person-years; 23% and 19% of children were born by CS in the 2 cohorts. There was no association of CS with IBD in the 2 cohorts. CONCLUSIONS: Findings from 2 population-based cohorts in Atlantic Canada did not provide any evidence for an association between CS and IBD in childhood and young adulthood.

6TiSCH on SCµM: Running a Synchronized Protocol Stack without Crystals.

We report the first time-synchronized protocol stack running on a crystal-free device. We use an early prototype of the Single-Chip micro Mote, SCµM, a single-chip 2×3 mm 2 mote-on-a-chip, which features an ARM Cortex-M0 micro-controller and an IEEE802.15.4 radio. This prototype consists of an FPGA version of the micro-controller, connected to the SCµM chip which implements the radio front-end. We port OpenWSN, a reference implementation of a synchronized protocol stack, onto SCµM. The challenge is that SCµM has only on-chip oscillators, with no absolute time reference such as a crystal. We use two calibration steps - receiving packets via the on-chip optical receiver and RF transceiver - to initially calibrate the oscillators on SCµM so that it can send frames to an off-the-shelf IEEE802.15.4 radio. We then use a digital trimming compensation algorithm based on tick skipping to turn a 567 ppm apparent drift into a 10 ppm drift. This allows us to run a full-featured standards-compliant 6TiSCH network between one SCµM and one OpenMote. This is a step towards realizing the smart dust vision of ultra-small and cheap ubiquitous wireless devices.