Higher Leak Rate Research Articles

Gas leakage from abandoned wells: A case study for the Groningen field in the Netherlands

The Groningen gas field in the Netherlands has been a major source of natural gas in Europe for the past few decades. There are approximately 350 wells drilled in the field that either already are or will be plugged and abandoned in the near future. In this work, we developed a two-phase, two-component numerical model based on the stratigraphy and the petrophysical data from a well in the Groningen field. The focus was to estimate the magnitude of methane leakage from the abandoned reservoir and the shallow gas-bearing formations. Methane is a potent greenhouse gas and fugitive methane emission from abandoned wells is of concern. The results indicate that highly depleted reservoirs are not a likely source of leakage, as long as they are not re-pressurized. However, shallow gas-bearing formations capable of bulk gas flow can pose a significant leakage risk. Permeable intermediate formations between the gas source and freshwater aquifers can act as a buffer zone, reducing the maximum rate of leakage into the atmosphere/aquifer system. For a mildly damaged cement sheath (1 mD) with a viable gas source, the leakage rate is relatively small (less than 30 kg/year of methane). The high leakage rate scenario results in a leakage rate as high as 4500 kg/year, with a methane plume in the freshwater aquifer that extends up to 450 m away from the well after 100 years. The results of this study can be used to identify wells that are at a higher risk of gas leakage, and the relative consequence of such phenomena on greenhouse gas emissions and local freshwater quality.

Outcomes among trauma patients with duodenal leak following primary versus complex repair of duodenal injuries: An Eastern Association for the Surgery of Trauma multicenter trial.

Duodenal leak is a feared complication of repair, and innovative complex repairs with adjunctive measures (CRAM) were developed to decrease both leak occurrence and severity when leaks occur. Data on the association of CRAM and duodenal leak are sparse, and its impact on duodenal leak outcomes is nonexistent. We hypothesized that primary repair alone (PRA) would be associated with decreased duodenal leak rates; however, CRAM would be associated with improved recovery and outcomes when leaks do occur. A retrospective, multicenter analysis from 35 Level 1 trauma centers included patients older than 14 years with operative, traumatic duodenal injuries (January 2010 to December 2020). The study sample compared duodenal operative repair strategy: PRA versus CRAM (any repair plus pyloric exclusion, gastrojejunostomy, triple tube drainage, duodenectomy). The sample (N = 861) was primarily young (33 years) men (84%) with penetrating injuries (77%); 523 underwent PRA and 338 underwent CRAM. Complex repairs with adjunctive measures were more critically injured than PRA and had higher leak rates (CRAM 21% vs. PRA 8%, p < 0.001). Adverse outcomes were more common after CRAM with more interventional radiology drains, prolonged nothing by mouth and length of stay, greater mortality, and more readmissions than PRA (all p < 0.05). Importantly, CRAM had no positive impact on leak recovery; there was no difference in number of operations, drain duration, nothing by mouth duration, need for interventional radiology drainage, hospital length of stay, or mortality between PRA leak versus CRAM leak patients (all p > 0.05). Furthermore, CRAM leaks had longer antibiotic duration, more gastrointestinal complications, and longer duration until leak resolution (all p < 0.05). Primary repair alone was associated with 60% lower odds of leak, whereas injury grades II to IV, damage control, and body mass index had higher odds of leak (all p < 0.05). There were no leaks among patients with grades IV and V injuries repaired by PRA. Complex repairs with adjunctive measures did not prevent duodenal leaks and, moreover, did not reduce adverse sequelae when leaks did occur. Our results suggest that CRAM is not a protective operative duodenal repair strategy, and PRA should be pursued for all injury grades when feasible. Therapeutic/Care Management; Level IV.

Transformer DGA Fault Diagnosis Method Based on Stacked Sparse Auto-Encoders

In the field of transformer fault diagnosis, the imbalance of fault samples seriously affects the fault identification performance of the diagnosis model. Focusing on the problems of low accuracy and high leakage rate of diagnosis model caused by unbalanced fault samples of transformer, a transformer fault diagnosis method is proposed. First of all, the Borderline SMOTE algorithm is used to balance the fault data set from a few samples on the boundary, so as to achieve the effect of power transformer fault sample equalization. Secondly, a diagnosis model of the stacked sparse auto-Encoders with the gas in oil as input characteristic parameter is built. Finally, an evaluation system consisting of accuracy rate, recall rate and F1 score is selected to compare the diagnosis effect of the model before and after category equalization, the experiment proves the effectiveness of this method.

ჰიბრიდული სისტემა სუპერმარკეტებისთვის გლობალური დათბობის დაბალი პოტენციალის მქონე მაცივარი აგენტების გამოყენებით

Global pressure has intensified to reduce the use of R404a with high global warming potential and relatively high leak rates in supermarket systems. In Europe, several design modifications such as cascade systems and new refrigerant choices are being investigated. One of the new leading options is to utilize a hybrid cascade system using CO2 in low temperature refrigeration circuit and R134a in medium temperature. R134a has higher efficiency than R404a and about one third the direct global warming potential (GWP). To make even greater gains in GWP reduction, a new lower GWP refrigerant has been developed that is retrofittable in the medium temp R134a circuit with minimal system changes. This refrigerant has less than half the GWP of R134a and is also non-flammable. This paper will show results of experimental calorimeter and supermarket system performance. A TEWI analysis will also be presented to demonstrate the significant reduction in environmental impact if XP10 is used in a hybrid cascade system with CO2.

Emergent Subtotal Colectomies Have Higher Leak Rates in Subsequent J-Pouch Stages

PurposeThe most common surgery for ulcerative colitis (UC) is the staged restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). On occasion, an emergent first-stage subtotal colectomy must be performed. The purpose of this study was to compare rates of postoperative complications in three-stage IPAA patients who underwent emergent vs non-emergent first-stage subtotal colectomies in the subsequent staged procedures. MethodsThis was a retrospective chart review conducted at a single tertiary care inflammatory bowel disease (IBD) center. All UC or IBD-Unspecified patients who underwent a three-stage IPAA between 2008 and 2017 were identified. Emergent surgery was defined as that performed on an inpatient who had perforation, toxic megacolon, uncontrolled hemorrhage, or septic shock. The primary outcomes were the presence of anastomotic leak, obstruction, bleeding, and the need for reoperation for each within a 6-month postoperative period of the second (RPC with IPAA and DLI) and third surgical stages (ileostomy reversal). ResultsA total of 342 patients underwent a three-stage IPAA, of which 30 (9.4%) had emergent first-stage operations. Patients who underwent an emergent STC were more likely to have a post-operative anastomotic leak and need an additional procedure following the subsequent second and third-staged operations on both univariate and multivariate analysis (p < 0.05). No difference was found for obstruction, wound infection, intra-abdominal abscess, or bleeding (p > 0.05). ConclusionThree-stage IPAA patients with emergent first-stage subtotal colectomies were more likely to have a post-operative anastomotic leak and need an additional procedure for a leak following the subsequent second- and third-stage operations.

Modeling the infection risk and emergency evacuation from bioaerosol leakage around an urban vaccine factory

Mounting interest in modeling outdoor diffusion and transmission of bioaerosols due to the prevalence of COVID-19 in the urban environment has led to better knowledge of the issues concerning exposure risk and evacuation planning. In this study, the dispersion and deposition dynamics of bioaerosols around a vaccine factory were numerically investigated under various thermal conditions and leakage rates. To assess infection risk at the pedestrian level, the improved Wells-Riley equation was used. To predict the evacuation path, Dijkstra’s algorithm, a derived greedy algorithm based on the improved Wells-Riley equation, was applied. The results show that, driven by buoyancy force, the deposition of bioaerosols can reach 80 m on the windward sidewall of high-rise buildings. Compared with stable thermal stratification, the infection risk of unstable thermal stratification in the upstream portion of the study area can increase by 5.53% and 9.92% under a low and high leakage rate, respectively. A greater leakage rate leads to higher infection risk but a similar distribution of high-risk regions. The present work provides a promising approach for infection risk assessment and evacuation planning for the emergency response to urban bioaerosol leakage.

Characterizing the obesogenic and fatty liver-inducing effects of Acetyl tributyl citrate (ATBC) plasticizer using both in vivo and in vitro models

The global incidence of obesity and non-alcoholic fatty liver disease (NAFLD) is rising rapidly in recent years. Environmental factors including usage of plastics and exposure to chemicals have been proposed as important contributors to the obesity pandemic. Acetyl tributyl citrate (ATBC) is a non-phthalate plasticizer widely used in food packaging, personal care products, medical devices and children’s toys etc. Due to its high leakage rate from plastics, exposure risk of ATBC keeps increasing. Although there are some studies investigating the safety of ATBC on human health, these studies mainly focused on high dosages and information regarding ATBC safety at environmental-relevant low levels is still limited.In this study, we aimed to evaluate the safety of subchronic exposure to environmentally-relevant concentrations of ATBC. C57BL/6J mice were orally exposed to ATBC for 6 or 14 weeks. Results indicated that ATBC exposure increased the body weight gain, the body fat content and the size of adipocytes, induced liver steatosis in mice. Consistent with in vivo effects, ATBC treatment increased the intracellular lipid accumulation in vitro hepatocytes. Transcriptome sequencing, qRT-PCR analysis and western blotting revealed that ATBC exposure affected the expression of genes involved in de novo lipogenesis and lipid uptake.Therefore, based on our subchronic and in vitro results, it suggested that ATBC might be a potential environmental obesogen with metabolism-disturbing and fatty liver-inducing risk, and its application in many consumer products should be carefully re-evaluated.

HPB P18 The introduction of antimicrobial-coated sutures to reduce the rate of surgical site infections in the hepatopancreaticobiliary (HPB) department: a quality improvement project

Abstract Background Surgical site infections (SSIs) are the most common postoperative complication in developed countries. In the United Kingdom (UK), the most recent data from Public Health England showed that ten-year trends in SSI risk varied by surgical group, with the highest risk observed in hepatopancreaticobiliary (HPB) surgery. Several methods for SSI prevention have been researched and implemented in surgical practice such as appropriate antibiotic prophylaxis, hair removal and careful sterilisation of equipment. Due to their chemical composition, sutures utilised in abdominal surgery can promote bacterial colonisation. Antimicrobial-coated sutures have been manufactured to investigate if the addition of a synthetic, non-ionizing, broad-spectrum antimicrobial can prevents colonisation, reduce the rate of bacterial adherence and therefore decrease the rate of SSIs. In 2021, NICE released a statement advising the use of antimicrobial-coated sutures as part of a bundle of care in wound closure to prevent site infection after surgical procedures. Little research is available on the use of antimicrobial-coated sutures for anastomosis closure. We carried out a quality improvement project, assessing the rate of SSI with standard sutures, followed by the use of antimicrobial-coated sutures to investigate reduction on SSI rates for both anastomosis and skin closure. Methods A quality improvement project, following the PDSA cycle, was carried out investigating rates of SSIs on all HPB patients undergoing an open procedure at Churchill Hospital, Oxford between November 2020 and June 2021. Data on SSI rates was collected electronically based on ward round entries, radiology and microbiology results. SSI were classified as ‘superficial’, ‘deep’ and ‘organ’ site infections based on the UK Health Security Agency (UKHSA) classification criteria. Antimicrobial-coated sutures were introduced in June 2021 and data was collected until November 2021. Chi-squared tests (X2) were carried to compare SSI results between the two groups. Secondary analysis was carried out examining culture results for organ SSIs. Results 167 patients had open operations between November 2020 and November 2021. 88 patients had standard sutures, 28/88 (32%) developed SSIs, of which 20/28 (71%) were organ SSIs. 79 patients had antimicrobial-coated sutures. 17/79 (22%) developed SSIs, of which 12/17 (72%) were organ SSIs. There was an overall 10% reduction in SSI rates [X2 (1, N= 212) = 0.04, p-value &amp;gt; 0.05)]. Crucially, there was a reduction in positive cultures with antimicrobial-coated sutures, where 42% of samples sent for microbiology analysis, compared to 25% in standard sutures, were negative cultures [X2 (1, N= 34) = 1.29, p-value &amp;gt; 0.05)]. Conclusions There is reduction in superficial and organ SSIs when antimicrobial-coated sutures are utilised. Crucially, there is a marked reduction in positive cultures when these are used for anastomosis closure. As hepatopancreaticobiliary surgery has a high leak rate of 10–30% after resection, a proportion of patients will develop abdominal collections due to leaks and not due to infection. Further multi-centre studies with larger sample sizes need to be carried out within the HPB population to further investigate reduction in SSI caused by antimicrobial-coated sutures and the impact it has on microbiology cultures. Almost half of culture samples sent for microbiology analysis from radiologically confirmed organ SSIs grew negative cultures. Further research is needed to determine if the definition of what is considered an organ SSI in the HPB population needs changing and if the UKHSA criteria needs re-classification in this surgical group in light of both the percentage of negative cultures reported and the standard leak rate in these operations.

Akiyama Procedure as a Surgical Option for Esophageal Cancer

Background The purpose of this study is to introduce our experience with the Akiyama procedure as a surgical option for treatment of esophageal cancer in the Mother Theresa Hospital Center of Tirana, Albania. Selection of the suitable site for anastomosis after esophagectomy, whether cervical or thoracic is the key for optimal oncological results. The goal is to minimize recurrence in oncological patients and to avoid complications related to surgery. Controversy still exists among surgeons as the optimal site for anastomosis as well as whether the anastomosis is done manually or with a stapler. Material and methods From October 2018 to June 2021, 27 surgical interventions of esophageal cancer were performed in our surgical unit. In 15 patients, subtotal esophagectomy Ivor-Lewis with a mediastinal esophago-gastric anastomosis was performed. In 8 patients, distal esophagectomy and proximal gastrectomy with an abdominal esophago-gastric anastomosis was performed. In 4 patients, subtotal esophagectomy with a cervical esophago-gastric anastomosis, Akiyama procedure was performed. In this study we are evaluating the Akiyama procedure with description of the technique, patient criteria of inclusion, oncological protocol and postoperative care. Discussion In our practice we used chemotherapy and radiotherapy as part of a multimodality treatment plan. All of our patients with carcinoma had radiation and chemotherapy prior to surgery. The use of stapler devices in cervical anastomoses in some studies is linked with higher rate of leakage but we consider it a preferential choice of the surgeon. We opted for a one-layer esophagogastric anastomosis in the neck as shown in some studies instead of the two-layer technique because of lower rates of stricture formation. The level of exposure in the cervical route is advantageous in making an accurate anastomosis. In our patients we used the retrosternal space for esophageal replacement to avoid local tumor recurrence in the posterior mediastinum. Conclusion As in other cancers there is a mandatory evaluation in congruence to the guidelines in order to each patient have a surgical or adjuvant therapy according to its stage. As per guidelines patients in a T1-2, N0 stage are treated with surgery alone and a close follow up for recurrence and patients in a T3 or N1/M1 stage should be considered for adjuvant therapy prior to surgery. In patients that have extensive disease and are not surgical candidates are considered for chemotherapy and radiation alone. It is advised that the type of surgery performed is the one in which the surgeon is more experienced and has the best outcome in terms of surgical strategy in terms of morbidity and mortality. Keywords: General surgery, Esophageal cancer, Akiyama procedure, Cervical esophago-gastric anastomosis. DOI: 10.7176/ALST/96-02 Publication date: December 31 st 2022

Use of a 3D-printed body surface percutaneous puncture guide plate in vertebroplasty for osteoporotic vertebral compression fractures.

Percutaneous vertebroplasty (PVP) has been used widely to treat osteoporotic vertebral compression fractures (OVCFs). However, it has many disadvantages, such as excessive radiation exposure, long operation times, and high cement leakage rates. This study was conducted to explore the clinical effects and safety of the use of a three-dimensional (3D)-printed body-surface guide plate to aid PVP for the treatment of OVCFs. This prospective cohort study was conducted with patients with OVCFs presenting between October 2020 and June 2021. Fifty patients underwent traditional PVP (group T) and 47 patients underwent PVP aided by 3D-printed body-surface guide plates (3D group). The following clinical and adverse events were compared between groups: the puncture positioning, puncture, fluoroscopy exposure and total operation times; changes in vertebral height and the Cobb angle after surgery relative to baseline; preoperative and postoperative visual analog scale and Oswestry disability index scores; and perioperative complications (bone cement leakage, neurological impairment, vertebral infection, and cardiopulmonary complications. The puncture, adjustment, fluoroscopy, and total operation times were shorter in the 3D group than in group T. Visual analog scale and Oswestry disability index scores improved significantly after surgery, with significant differences between groups (both p < 0.05). At the last follow-up examination, the vertebral midline height and Cobb angle did not differ between groups. The incidence of complications was significantly lower in the 3D group than in group T (p < 0.05). The use of 3D-printed body-surface guide plates can simplify and optimize PVP, shortening the operative time, improving the success rate, reducing surgical complications, and overall improving the safety of PVP.

Accurate segmentation of small targets for LCD defects using deep convolutional neural networks

AbstractFor the purpose of effectively solving the problems of manual inspection of thin‐film transistor–liquid crystal display (TFT‐LCD) with spot Mura high leakage rate and time consuming, this article proposes a visual detection method for LCD defects based on Mask R‐CNN convolutional neural network. In this article, a new feature extraction network is built by fusing ResNet with efficient channel attention (ECA) channel attention mechanism, and a new feature fusion network is constructed by adding ECA channel attention mechanism to Feature Pyramid Network (FPN). In the dataset of self‐made display defect images collected at the production site, the current more advanced segmentation network was compared qualitatively and quantitatively with our method, and the results showed that the proposed method was more accurate in detecting spot Mura, with a detection accuracy of 91%.

Climate benefit of a future hydrogen economy

Hydrogen is recognised as an important future energy vector for applications in many sectors. Hydrogen is an indirect climate gas which induces perturbations of methane, ozone, and stratospheric water vapour, three potent greenhouse gases. Using data from a state-of-the-art global numerical model, here we calculate the hydrogen climate metrics as a function of the considered time-horizon and derive a 100-year Global Warming Potential of 12.8 ± 5.2 and a 20-year Global Warming Potential of 40.1 ± 24.1. The considered scenarios for a future hydrogen transition show that a green hydrogen economy is beneficial in terms of mitigated carbon dioxide emissions for all policy-relevant time-horizons and leakage rates. In contrast, the carbon dioxide and methane emissions associated with blue hydrogen reduce the benefit of a hydrogen economy and lead to a climate penalty at high leakage rate or blue hydrogen share. The leakage rate and the hydrogen production pathways are key leverages to reach a clear climate benefit from a large-scale transition to a hydrogen economy.

Acute Mesenteric Ischemia: Preexisting Comorbidity Determines Short-Term Outcome and Quality of Life in Long-Term Survivors

Introduction: Acute mesenteric ischemia (AMI), either arterial or venous, is still a devastating disease with poor prognosis. It is unknown, whether AMI is associated with impaired quality of life (QoL) in long-term survivors. Material and Methods: This retrospective analysis includes 64 patients with occlusive arterial or venous mesenteric ischemia treated operatively between 2008 and 2016 at the University Medical Center Rostock. Short-term outcome with focus on comorbidities was measured by the Charlson comorbidity index (CCI) an instrument that operationally measures comorbidity based on 17 clinical parameters including age. Operative outcome in view of enterostomy placement and long-term outcome measured as QoL by the EQ-5D in the long-term survivors were evaluated. The EQ-5D is a standardized, self-reported five-dimension QoL questionnaire built to provide a simple and generic measure of health. Results: Thirty-day mortality was 60.9%, and in-hospital mortality was 70.3% (n = 45). No patient was discharged with a stoma. Patients with a primary anastomosis after the initial operation for AMI had a high leak rate of 27% (4/15 patients) compared to no dehiscence in the group of patients who had secondary anastomosis during second or third laparotomy. The long-term survivors had significantly lower CCI compared to the 45 nonsurvivors (median 4 [3, 4, 5, 6] vs. 6 [4, 5, 6, 7]). All long-term survivors had QoL assessment. QoL score was significantly impaired compared to an age- and sex-matched reference population. This impairment was not due to disease-specific sequelae such as presence of stool deviation or intestinal failure but due to preexisting risk factors as shown by an inverse relation between the CCI and QoL score. Conclusion: Herein, we show for the first time that long-term QoL in patients with AMI is impaired but this impairment is not due to disease-specific aspects but rather general risk factors underlying the presence of a higher level of comorbidities at the time of AMI.

Formal Closure of Endoscopic Endonasal Skull Base Defects With a "Bow Tie" Tri-Layer Graft.

Risk factors for a postoperative cerebrospinal fluid leak (CSF) after surgery include an intraoperative high flow of CSF, elevated body mass index, defect size, and defect site. In our prior series, a high postoperative CSF leak rate for tumors of the central skull base (planum, sella, and clivus) appeared to be due to graft migration. We changed our closure technique from a single layer of collagen +/- fat graft to a novel graft, termed a "Bow tie" (a tri-layer fat graft with two pieces of collagen matrix), and report our results in this study. Retrospective temporal epoch study of a single otolaryngologist's experience of closing skull base defects in our skull base center from 2005 to 2017. One hundred and forty-nine patients met inclusion criteria in two time periods, pre- and post-introduction of the Bow tie technique. In epoch I, from 2005 to 2013, 79 patients had reconstruction with a single layer of dural graft (25 had additional free fat graft). In epoch II, from 2014 to 2017, 70 patients had reconstruction with the Bow tie. CSF leak rates were 8.7% overall: 15.2% in epoch I and 1.4% in epoch II (p= 0.01). After controlling the procedure, defects with a size greater than 2 cm had a 5.7 greater likelihood of failure. Epoch II had a lower incidence of major complications. Using a single surgeon's experience, the multilayer Bow tie has a significant reduction in postoperative CSF leak and associated major complications for defects of the central skull base. 3 Laryngoscope, 133:1568-1575, 2023.

486. ENDOSCOPIC VACUUM THERAPY FOR ANASTOMOTIC LEAKAGE AFTER ESOPHAGEAL RESECTION—A RETROSPECTIVE SINGLE-CENTER ANALYSIS

Abstract Esophagectomy still comes with a high rate of anastomotic leakage resulting in a persisting high postoperative mortality. Endoscopic vacuum therapy (EVT) is an upcoming technique for the treatment of anastomotic leakages. We aimed to evaluate our experience with the efficacy of EVT for anastomotic leakages after esophagectomy for cancer. We retrospectively analyzed all 96 patients who had undergone Ivor-Lewis resection for esophageal malignancy from January 2015 until December 2021 for the need of EVT within the same hospital stay. Patients demographics, perioperative parameters, treatment efficacy and success were analyzed. Patient data were expressed as mean ± standard deviation. We included fourteen patients treated with EVT following Ivor-Lewis resection for esophageal malignancy within the same hospital stay. 12 EVTs were due to anastomotic leakage whereas two procedures were performed prophylactically. We started the EVT 10.71 ± 8.04 days after surgery with a mean duration of 13.86 ± 7.39 days and a mean number of 4.36 ± 2.37 endoscopies per patient. Successful treatment was achieved in 10 patients (71.4%), one patient needed an esophageal stenting and an additional surgery for re-anastomosis was needed in 3 patients (21.4%). EVT can prevent re-operation in a high proportion of patients with anastomotic leakage and therefore provides a good non-surgical option for these patients. The periinterventional risk and possible complications of repetitive endoscopies should be analyzed in larger studies.

Analysis of an Elasto-Hydrodynamic Seal by Using the Reynolds Equation

This paper reports numerical studies of an Elasto-Hydrodynamic (EHD) seal, which is being developed for supercritical CO2 (sCO2) turbomachinery applications. Current sCO2 turbomachinery suffers from high leakage rates, which is creating a major roadblock to the full realization of sCO2 power technology. The high leakage rates not only penalize the efficiencies but also create environmental concerns due to greenhouse effects caused by the increased CO2 discharge to the atmosphere. The proposed EHD seal needs to work at elevated pressures (10–35 MPa) and temperatures (350–700 °C) with low leakage and minimal wear. The unique mechanism of the EHD seal provides a self-regulated constriction effect to restrict the flow without substantial material contact, thereby minimizing leakage and wear. This work utilizes a physics-based modeling approach. The flow through the gradually narrowing seal clearance is modeled by the well-known Reynolds equation in EHD lubrication theory, while the deformation of the seal is modeled by using the governing equations of three-dimensional solid mechanics. As for the solution methodology, COMSOL’s Thin-Film Flow and Solid Mechanics modules were employed with their powerful capabilities. The numerical results were presented and discussed. It was observed that the Reynolds equation fully coupled with the surface deformation was able to successfully capture the constriction effect. The maximum and minimum leakages were calculated to be 2.25 g/s and 0.1 g/s at P = 5.5 MPa and P = 11 MPa for the design seal, respectively. It was interesting to observe that the seal leakage followed a quadratic trend with increasing pressure differential, which can become advantageous for high-pressure applications such as sCO2 power generation technology.

Blood-brain barrier leakage years after pre-eclampsia: dynamic contrast-enhanced 7-Tesla MRI study.

Pre-eclampsia is a hypertensive complication of pregnancy that is associated with an increased risk of long-term cardiovascular and cerebrovascular disorders. Although the underlying mechanism of persistent susceptibility to cerebral complications after pre-eclampsia remains largely unclear, impaired blood-brain barrier (BBB) integrity has been suggested to precede several cerebrovascular diseases. In this study, we aimed to investigate the integrity of the BBB years after pre-eclampsia. This was an observational study of premenopausal formerly pre-eclamptic women and controls with a history of normotensive pregnancy who underwent cerebral magnetic resonance imaging (MRI) at ultra-high field (7Tesla) to assess the integrity of the BBB. Permeability of the BBB was determined by assessing leakage rate and fractional leakage volume of the contrast agent gadobutrol using dynamic contrast-enhanced MRI. BBB leakage measures were determined for the whole brain and lobar white and gray matter. Multivariable analyses were performed, and odds ratios were calculated to compare women with and those without a history of pre-eclampsia, adjusting for potential confounding effects of age, hypertension status at MRI and Fazekas score. Twenty-two formerly pre-eclamptic women (mean age, 37.8 ± 5.4 years) and 13 control women with a history of normotensive pregnancy (mean age, 40.8 ± 5.5 years) were included in the study. The time since the index pregnancy was 6.6 ± 3.2 years in the pre-eclamptic group and 9.0 ± 3.7 years in controls. The leakage rate and fractional leakage volume were significantly higher in formerly pre-eclamptic women than in controls in the global white (P = 0.001) and gray (P = 0.02) matter. Regionally, the frontal (P = 0.04) and parietal (P = 0.009) cortical gray matter, and the frontal (P = 0.001), temporal (P &lt; 0.05) and occipital (P = 0.007) white matter showed higher leakage rates in formerly pre-eclamptic women. The odds of a high leakage rate after pre-eclampsia were generally higher in white-matter regions than in gray-matter regions. This observational study demonstrates global impairment of the BBB years after a pre-eclamptic pregnancy, which could be an early marker of long-term cerebrovascular disorders. © 2022 The Authors. Ultrasound in Obstetrics &amp; Gynecology published by John Wiley &amp; Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Experiments and Analysis of a Peanut Semi-Feeding Picking Mechanism Based on the JKR Model

When peanuts are harvested, the high rate of pod crush and pods leakage are the main problems in the current peanut fruit picking process. Optimized peanut picking rollers help to improve peanut harvesting efficiency. This paper investigates the fruit picking system of a three-monopoly, six-row semi-feeding peanut combine harvester, in order to reduce the rate of crush and leakage of peanut pods during the picking process. Firstly, this article specifies the structure and basic parameters of peanut picking pairs of rollers. Secondly, this paper combines JKR (Johnson-Kendall-Roberts) model theory, crash model simulation analysis, a field test, and other methods. Motion and force analysis are presented in detail for the peanut picking mechanism and associated harvesting components. The optimum clamping chain speed, the angle of installation of the picking rollers to the clamping chain, and the picking rollers’ speed are determined. A three-factor, three-level regression orthogonal combination test was designed to obtain regression models for pod crushed and pods leakage rate. The regression model’s response surface analysis concluded that when the clamping chain speed is 0.84–1.2 m/s, the fruit picking roller angle is 10°–11.2° and the fruit picking roller speed is 442 r/min–500 r/min. It is the optimal working parameter for the three-monopoly six-row peanut combine harvester. At this point, the peanut harvesting requirements are met, and the overall performance is significantly improved. This paper lays the foundation for the development of the semi-feeding peanut picking system.

A Comparison of Different Types of Esophageal Reconstructions: A Systematic Review and Network Meta-Analysis.

Background: A total esophagectomy with gastric tube reconstruction is the mainstream procedure for esophageal cancer. Colon interposition and free jejunal flap for esophageal reconstruction are the alternative choices when the gastric tube is not available. However, to date, a solution for the high anastomosis leakage rates among these three types of conduits has not been reported. The aim of this network meta-analysis was to investigate the rate of anastomotic leakage (AL) among the three procedures to determine the best esophageal substitute or the future direction for improving the conventional gastric pull-up (GPU). Methods: We searched PubMed, Cochrane, and Embase databases. We included esophageal cancer patients receiving esophagectomy and excluded patients with other cancer. The random effect model was used in this network meta-analysis. The Newcastle–Ottawa Scale (NOS) was used for the quality assessment of studies in the network meta-analysis, and funnel plots were used to evaluate publication bias. The primary outcome is anastomosis leakage; the secondary outcomes are stricture formation, length of hospital stays, and mortality rate. Results: Nine studies involving 1613 patients were included in this network meta-analysis. The trend results indicated the following. Regarding anastomosis leakage, free jejunal flap was the better procedure; regarding stricture formation, colon interposition was the better procedure; regarding mortality rate, free jejunal flap was the better procedure; regarding length of hospital stay, gastric pull-up was the better treatment. Discussion: Overall, if technically accessible, free jejunal flap is a better choice than colon interposition when gastric conduit cannot be used, but further study should be conducted to compare groups with equal supercharged patients. In addition, jejunal flap (JF) cannot replace traditional gastric pull-up (GPU) due to technical complexities, more anastomotic sites, and longer operation times. However, the GPU method with the supercharged procedure would be a possible solution to lower postoperative AL. The limitation of this meta-analysis is that the number of articles included was low; we aim to update the result when new data are available. Funding: None. Registration: N/A.

Phase change composites based on double-shell microcapsules with high latent heat and low leakage rate for thermal energy storage and temperature regulation

A series of novel paraffin (Pn)@polymethyl methacrylate (PMMA)@silicon dioxide (SiO2) double-shell phase change microcapsules (Pn@PMMA@SiO2) were designed by interfacial polycondensation and radical polymerization, and then Pn@PMMA@SiO2 were embedded in high density polyethylene (HDPE) to fabricate HDPE/Pn@PMMA@SiO2 phase change composites (PCCs) by melt blending. The effect of PMMA contents on Pn@PMMA@SiO2 and Pn@PMMA@SiO2 contents on PCCs were investigated, respectively. Thermal and anti-permeable properties of Pn@PMMA@SiO2 and PCCs were characterized by differential scanning calorimetry (DSC) and leakage rate tests. The results showed that the enthalpy and leakage rate of Pn@PMMA@SiO2 with 10 wt% PMMA were 156.6 J/g and 1.85 %, which displayed outstanding latent heat storage/release capability and good anti-permeable property. And the PCCs with 40 wt% Pn@PMMA@SiO2 displayed dependable thermal energy storage capability as well, which could reach to 52.7 J/g. In addition, the tensile strength of PCCs-40 could be up to 19.9 MPa, and the density of PCCs was decreased with introduction of Pn@PMMA@SiO2. Hence, the new kind of PCCs can be used for thermal management and temperature regulation for lightweight building materials.