Small Cavity Research Articles

OGC SO14 - Management of Anastomotic Leaks after oesophagectomy for oesophageal cancer in the era of Endoscopic Vacuum Therapy

Abstract Background Anastomotic leak (AL) is a serious complication following oesophagectomy that occurs in 10-15% of patients. Endoscopic vacuum therapy (EVT) is a novel non-operative approach to managing AL that has become increasingly popular recently. However, little is known about EVT’s effectiveness in managing ALs compared to more established approaches. Method This was a retrospective review of consecutive AL management in a regional oesophageal cancer centre during two distinct time periods: prior to (group 1, 2014-2018) and following (group 2, 2018-2023) the introduction of EVT. 66 patients met the inclusion criteria. Patients were further classified according to size and type of leak, degree of mediastinal soiling and degree of sepsis. Primary endpoints were treatment success, 90-day mortality, and long-term preservation of gastrointestinal continuity. Secondary endpoints were the length of hospital stay (LOS) and re-interventions during the first postoperative year. Results 80.3% of patients (14 in group 1, 40 in group 2) had less than 1cm AL defect with present sepsis and a small mediastinal cavity. In group 1, 12 were treated successfully conservatively, and 2 (14.2%) had T-tube insertion. In group 2, 20 (50%) had conservative management and 19 (47.5%) had Esosponge insertion. The success rate was 95% and 94.7%, respectively. In bigger ALs (>1cm defect with severe sepsis), all patients in group I were treated with thoracotomy with a success rate of 75%, whereas in group 2, 60% were treated with Esosponge insertion with a success rate of 83.3%. Conclusion EVT is a safe and feasible therapy option. It appears to improve outcomes in septic patients with small ALs and potentially reduces the need for high-risk revisional operations.

Laser ablation ignition modes in a cavity-based supersonic combustor

A numerical and experimental study was conducted to investigate the Laser Ablation (LA) ignition mode in an ethylene-fueled supersonic combustor with a cavity flameholder. The experiments were operated under a Mach number 2.92 supersonic inflow, with stagnation pressure of 2.4 MPa and stagnation temperature of 1600 K. Reynolds-averaged Navier-Stokes simulations were conducted to characterize the mixing process and flow field structure. This study identified four distinct LA ignition modes. Under the specified condition, laser ablation in zero and negative defocusing states manifested two distinct ignition modes termed Laser Ablation Direct Ignition (LADI) mode and Laser Ablation Re-Ignition (LARI) mode, correspondingly. LA ignition in a local small cavity, created by depressing the flow field regulator, could facilitate the ignition mode transforming from LARI mode to Laser Ablation Transition Ignition (LATI) mode. On the other hand, the elevation of the flow field regulator effectively inhibited the forward propagation of the initial flame kernel and reduced the dissipation of LA plasma, further enhancing the LADI mode. Based on these characteristics, the LADI mode was subdivided into strong (LADI-S) and weak (LADI-W) modes. Facilitating the transition of ignition modes through alterations in the local flow field could contribute to attaining a more effective and stable LA ignition.

The organization of subglacial drainage during the demise of the Finnish Lake District Ice Lobe

Abstract. Unknown basal characteristics limit our ability to simulate the subglacial hydrology of rapidly melting contemporary ice sheets. Sediment-based landforms generated beneath Late Pleistocene ice sheets, together with detailed digital elevation models, offer a valuable means of testing basal hydrology models, which describe the flow and dynamics of water in the subglacial system. However, to date no work has evaluated how well process-based subglacial hydrology models represent the hypothesized conditions associated with glaciofluvial landform formation in the palaeo setting. Previous work comparing model output to geomorphological evidence has typically done so using models that do not resolve subglacial processes and instead express likely subglacial water pathways. Here, we explore the ability of the Glacier Drainage System model (GlaDS), a process-based subglacial hydrology model, to represent the genesis conditions associated with a specific glaciofluvial landform termed “murtoos”. Distinctive triangular landforms found throughout Finland and Sweden, murtoos are hypothesized to form 40–60 km from the former Fennoscandian Ice Sheet margin within a “semi-distributed” system at the onset of channelized drainage in small cavities where water pressure is equal to or exceeds ice overburden pressure. Concentrating within a specific ice lobe of the former Fennoscandian Ice Sheet and using digital elevation models with a simulated former ice surface geometry, we forced GlaDS with transient surface melt and explored the sensitivity of our model outcomes to parameter decisions such as the system conductivity and bed topography. Our model outputs closely match the general spacing, direction, and complexity of eskers and mapped assemblages of features related to subglacial drainage in “meltwater routes”. Many of the predictions for murtoo formation are produced by the model, including the location of water pressure equal to ice overburden, the onset of channelized drainage, the transition in drainage modes, and importantly the seasonal sequence of drainage conditions inferred from murtoo sedimentology. These conclusions are largely robust to a range of parameter decisions, and we explore seasonal and inter-annual drainage behaviour associated with murtoo zones and meltwater pathways. Our results demonstrate that examining palaeo basal topography alongside subglacial hydrology model outputs holds promise for the mutually beneficial analyses of palaeo and contemporary ice sheets to assess the controls of hydrology on ice dynamics and subglacial landform evolution.

An artificial intelligence-based landmark model for early detection of aortic stenosis in Cardiac MRI

Abstract Background The utilisation of ratiometric intensity measures from cardiac magnetic resonance imaging (CMR) offers a promising biomarker for the diagnosis of aortic stenosis (AS)[1]. The Ao:LV ratio, an approximation of AS severity, is determined by comparing the relative blood signal intensity in the aorta and left ventricle (LV) within three-chamber (3Ch) cine sequences[1]. In patients with AS, the blood signal intensity of aortic blood above the valve is diminished compared to that within the LV in steady-state free precession (SSFP) 3Ch CMR cine. Although the Ao:LV ratio serves as a reliable indicator of AS severity, manual computation of this ratio may encounter difficulties due to visual obstructions caused by small LV cavities or prominent papillary muscles. Purpose This study aims to leverage artificial intelligence (AI) to automate the Ao:LV ratio analysis from 3Ch SSFP cine images and introduce the Ao:LA (aorta to left atrium) ratio, thus enhancing the diagnostic accuracy for AS severity. Methods Our methodology extends the ratiometric analysis to include both Ao:LV and Ao:LA ratios in three main steps: first, developing an AI-based algorithm for automated detection and tracking of cardiac landmarks; second, using these landmarks to automatically compute regions of interest (ROIs) in the cardiac chambers; and third, training and validating classification models with 5-fold cross-validation to select the most effective for AS severity classification. The final model's performance is assessed on a holdout test set. Data for model training and evaluation were sourced from CMR scans across three hospitals and two scanner types. Results We analysed 220 patients of which 78 patients had no AS and 122 had AS (mild AS, n = 29; moderate AS; n = 35, severe AS; n = 78). Our model yielded high efficacy in classifying AS, particularly in differentiating any grade of AS from a normal classification, which is clinically relevant. The Ao:LA ratio demonstrated a stronger correlation with AS severity class than Ao:LV, suggesting a more reliable biomarker. The proposed model demonstrated robust performance in AS classification, achieving an Area Under the Curve (AUC) of 0.845 in the automated binary classification of AS at any grade. The model exhibited a precision of 0.889, recall of 0.865, and an F1 score of 0.877 on a holdout set. Conclusion By the integration of AI in automating the analysis of CMR images through a novel ratiometric approach that includes Ao:LV and Ao:LA ratios, our model significantly improves the accuracy of early AS detection. This advancement enhances imaging strategies for AS evaluation, promoting more efficient and effective use of cardiac MRI sequences as a diagnostic tool for aortic stenosis. It has the potential to be implemented in real-time scanning protocols as a clinical decision support system.AI-inferred cardiac landmarks.ROC curve delineating AS prediction.

Loose particle Detection: The optimal detection condition and weak loose particle impulse extraction

To achieve effective detection of loose particles within small cavities in microelectronic devices, this paper proposes the optimal detection conditions of loose particles in ceramic packaging for microelectronic devices based on simulation, and presents a method for weak signal reconstruction using weighted sparse representation. To address the challenge of ineffective detection of loose particles under recommended vibration conditions, a particle-cavity collision dynamics model is established. Subsequently, the detection laws of loose particles under different accelerations, frequencies, and cavity heights are studied through simulation, leading to the establishment of optimal detection conditions for microelectronic devices with varying cavity heights. To address the issue of weak impulses being submerged in background noise under optimal detection conditions, sparse representation is utilized for signal reconstruction. First, a Laplace wavelet dictionary is constructed according to the impulse characteristics. Second, the generalized minimax-concave (GMC) penalty function is applied as a sparse regularization term to preserve signal amplitude. Meanwhile, a weight matrix based on kurtosis and singular value is designed to threshold sparse coefficients. The results demonstrate that the proposed optimal detection conditions and signal reconstruction method effectively detect loose particles. Compared with other algorithms, the proposed method reduces background noise in the particle impact noise detection (PIND) signals while maintaining impulse amplitude; it also improves signal reconstruction accuracy and offers valuable insights into effective loose particle detection in microelectronic packaging devices.

Lobar graft evaluation in cadaveric lobar lung redo transplantation after living-donor lobar lung transplantation: a case report

BackgroundLung transplantation is a vital option for patients with end-stage lung disease. However, it faces a significant challenge due to the shortage of compatible donors, which particularly affects individuals with small chest cavities and pediatric patients. The novel approach of cadaveric lobar lung transplantation is a promising solution to alleviate the donor shortage crisis. Both the mid-term and long-term outcomes of lobar lung transplantation are comparable to those of standard lung transplantation. However, patients undergoing lobar lung transplantation reported a significantly higher rate of primary graft dysfunction compared to patients undergoing standard lung transplantation. Therefore, careful donor selection is critical to improve outcomes after lobar transplantation. However, no established method exists to evaluate each lung lobar graft of deceased donors. This case report describes a case of cadaveric lobar lung transplantation to overcome size mismatch and donor shortage, with particular emphasis on lobar graft evaluation.Case presentationA 39-year-old woman with scleroderma-related respiratory failure was listed for deceased donor lung transplantation due to a rapidly progressing disease. Faced with a long waiting list and impending mortality, she underwent bilateral living-donor lobar lung transplantation donated by her relatives. Post-transplant complications included progressive pulmonary vein obstruction and pleural effusion, which ultimately required retransplantation. An oversized donor with pneumonia in the bilateral lower lobes was allocated. Lung ultrasound was used to evaluate each lung lobar graft during procurement. The right upper and middle lobes and left upper lobe were confirmed to be transplantable, and lobar lung redo transplantation was performed. The patient’s post-transplant course was uneventful, and she was discharged home and returned to her daily activities.ConclusionsThis case highlights the clinical impact of cadaveric lobar lung transplantation as a feasible and effective strategy to overcome the shortage of donor lungs, especially in patients with small thoracic cavities. By establishing donor lung evaluation techniques and overcoming anatomical and logistical challenges, cadaveric lobar lung transplantation can significantly expand the donor pool and offer hope to those previously considered ineligible for transplantation.

Dosimetry in MRgPT: Impact of magnetic fields on TLD dose response during proton irradiation.

Proton beam therapy, when integrated with MRI guidance, presents complex dosimetric challenges due to interactions with magnetic fields. Prior research has emphasized the nuanced impact of magnetic fields on dosimetry. For thermoluminescent dosimeters (TLDs) the electron-return effect, alongside small air cavities surrounding the pellets, can lead to nonuniform dose distributions. Future MR-guided proton therapy will require reliable methods for end-to-end tests and dosimetric audits, which so far are often performed using TLDs equipped with phantoms. This implicates the necessity of accounting for theseinteractions. This study investigates the influence of magnetic fields on TLDs at two proton energies, using magnetic field strengths of 0, 0.25, and , aiming to clarify their impact on dose measurementaccuracy. The study was conducted at a synchrotron-based ion beam therapy beam line, enhanced by a resistive dipole magnet for creating magnetic fields up to to simulate MR-guided proton therapy. Individual correction factors were applied for TLD measurements. The impact of air gaps on the TLD signal was evaluated using three dedicated TLD holders with air gaps of 0.1, 0.25, and 0.5 mm surrounding the TLD pellets using the highest available proton energy of . Additionally, the influence of the magnetic field strength on the TLD response was evaluated for two proton energies of and . The study found no statistically significant variation in TLD dose response attributable to changes in the air gap or the presence of magnetic fields. A power analysis indicated an upper limit on a potential change in dose-response as small as 1.5%. The findings suggested that the impact of air gap variations and magnetic field strengths on the TLD response was below the detection threshold of TLD sensitivity. This emphasizes the suitability of TLDs for dose measurement in MR-guided proton therapy, indicating that additional correction factors may not be necessary despite the influence of magneticfields.

Management of gastroschisis in an extremely low birth weight infant: report of a case

BackgroundGastroschisis is a rare congenital anomaly in which abdominal organs herniate through a defect in the abdominal wall. Managing gastroschisis in extremely low birth weight (ELBW) infants presents significant challenges because of their immature physiologies and increased risk of complications.Case presentation: This report discusses the case of a female ELBW infant born via an emergency cesarean section at 29 weeks of gestation, weighing 768 g, who had a prenatal diagnosis of gastroschisis. Postnatal management included immediate surgical intervention using a hand-made silo manufactured from expanded polytetrafluoroethylene (ePTFE) sheets that were sutured to the patient’s abdominal wall to accommodate her small abdominal cavity and preserve mesenteric blood flow. Necrotizing enterocolitis with bowel perforation emerged as a complication, which led to the excision of a 10 cm segment of the ileum and the creation of an ileostomy. The infant experienced insufficient weight gain and liver dysfunction. However, she was eventually discharged on day 142 of life, weighing 2774 g, on oral feeding, without significant complications.ConclusionsThis case emphasizes how prematurity significantly affected the patient’s clinical outcomes, and highlights the importance of individualized management strategies. Our experience demonstrates that custom silo placement allows for the size to be adapted to the abdominal defect, and highlights the critical need to prioritize postnatal bowel perfusion in ELBW infants with gastroschisis.

Perineal fistulation secondary to retained appendicolith: A rare complication of the unaccounted calculus

An approximately 30-year-old male patient presented with perianal fistula disease. Examination under anesthetic revealed a complex extrasphinteric tract with internal opening in the region of the anterior inferior rectum, although an internal opening was not clearly identified. This failed to heal despite defunctioning procedure and packing of the perineal tract. Specialist center review of computed tomography and magnetic resonance imaging revealed a small cavity anterior to the rectum containing a small calcific density with a long tract extending down into the perineum. Seven years earlier, the patient had presented with clinical features of appendicitis. On retrospective review, an appendicolith can be seen on ultrasound and abdominal X ray (AXR). At surgery, the appendix had disintegrated leaving an abscess cavity. The appendicolith was not appreciated or removed and subsequently migrated into the pelvis acting as a source of infection which fistulated to the perineum. Subsequent removal of the calculus resulted in complete healing.

Acute middle cerebral artery occlusion due to a small internal carotid aneurysm cavity with blood stagnation: illustrative case.

In cerebral large vessel occlusion, even when an aneurysm is close to the target vessel, if the aneurysm is relatively small and angiography shows no thrombus within the aneurysm, it is difficult to identify the aneurysm as the embolic source. A 67-year-old man with a history of two left-sided cerebral infarctions developed a small left-sided cerebral infarction. On hospital day 3, he developed a left M2 occlusion and underwent thrombectomy with retraction of a stent retriever into an aspiration catheter at the proximal end of the thrombus. A red thrombus was retrieved, and M2 recanalization was successfully achieved. Angiography revealed a large partially thrombotic aneurysm with a small cavity with blood stagnation in the left cervical internal carotid artery, which was considered the embolic source. Stent-assisted coil embolization was performed on the aneurysm, and no recurrent cerebral infarction was observed after embolization. In cerebral large vessel occlusion, an aneurysm cavity with blood stagnation may be the embolic source. Using an aspiration catheter alone or retracting a stent retriever into an aspiration catheter could be a useful technique and help to avoid interference between the aneurysm and the stent retriever. https://thejns.org/doi/10.3171/CASE24406.

Quercetin regulates pulmonary vascular remodeling in pulmonary hypertension by downregulating TGF-β1-Smad2/3 pathway

BackgroundPulmonary arterial hypertension (PAH) is a worldwide challenging disease characterized by progressive elevation of pulmonary artery pressure. The proliferation, migration and phenotypic transformation of pulmonary smooth muscle cells are the key steps of pulmonary vascular remodeling. Quercetin (3,3', 4', 5, 6-pentahydroxyflavone, Que) is a natural flavonol compound that has antioxidant, anti-inflammatory, anti-tumor and other biological activities. Studies have shown that Que has therapeutic effects on PAH. However, the effect of quercetin on pulmonary vascular remodeling in PAH and its mechanism remain unclear.Methods and resultsIn vivo, PAH rats were constructed by intraperitoneal injection of monocrotaline (MCT) at 60 mg/kg. Human pulmonary artery smooth muscle cells (HPASMCs) were treated with platelet-derived growth factor BB (PDGF-BB) 20 ng/mL to construct PAH cell model in vitro. The results showed that in vivo studies, MCT could induce right ventricular wall hyperplasia, narrow the small and medium pulmonary artery cavity, up-regulate the expression of proliferating and migration-related proteins proliferating cell nuclear antigen (PCNA) and osteopontin (OPN), and down-regulate the expression of alpha-smooth muscle actin (α-SMA). Que reversed the MCT-induced results. This process works by down-regulating the transforming growth factor-β1 (TGF-β1)/ Smad2/3 signaling pathway. In vitro studies, Que had the same effect on PDGF-BB-induced proliferation and migration cell models.ConclusionsQue inhibits the proliferation, migration and phenotypic transformation of HPASMCs by down-regulating TGF-β1/Smad2/Smad3 pathway, thereby reducing right ventricular hyperplasia (RVH) and pulmonary vascular remodeling, providing potential pharmacological and molecular explanations for the treatment of PAH.

Autoinjector optimization through cavitation response and severity minimization

Abrupt acceleration of the syringe of an autoinjector (AI) upon rod-plunger impact may induce undesired severe cavitation events and impose extraneous stresses upon the device, leading to device failure. Cavitation results from a rapid and significant pressure drop in a liquid, leading to the formation and growth of small vapor-filled cavities. Upon collapse, these cavities generate an intense shock wave that may lead to protein aggregation and device container damage and shatter. Since the maximum acceleration of the syringe depends upon the operating conditions of the AI, the severity of cavitation will likewise depend on the operating conditions of the AI. Likewise, injection time and ensuring proper needle displacement before drug release also depend on operating conditions, making optimization of the autoinjector a multiobjective optimization problem.Therefore, in this study, optimization of an autoinjector to limit cavitation severity is pursued via an experimentally validated computational model for cavitation in spring-driven autoinjectors. Our goal is to locate AI design configurations that balance maximizing device performance and patient comfort and minimizing the risks of device damage and severe cavitation upon actuation.Relevant parameters of interest are the drive spring force, air gap height, solution viscosity, friction between the rod and spring, frictional force on the plunger, rates of change of frictional force on the plunger, elasticity of plunger, viscosity of the plunger, and initial displacement between the plunger and the driving rod. The kinematics of the syringe barrel, needle displacement (travel distance) at the start of drug delivery, and injection time are gathered using an experimentally validated autoinjector kinematics model. At the same time, cavitation bubble dynamics are resolved using an experimentally validated cavitation model that takes the temporal displacement of the syringe and temporal air gap pressure as inputs.We use our experimentally validated models to explore the parameter space and understand the driving factors of our desired outcomes. Subsequently, we pose the design problem as a multi-objective optimization problem and develop a deep neural network surrogate model supplemented with iterative learning to speed up optimization. A variance-based sensitivity analysis was performed to determine the sensitivity and influence of design parameters on the outcomes, and the main contributors to the outcomes of interest were isolated. Using a multi-objective optimization framework, we located 300 + successful candidates and evaluated them through uncertainty analysis to identify three promising candidates that meet all criteria for drug viscosities of interest. Finally, we show that this methodology can be used to conduct hypothesis testing, leading to novel design configurations.

Improved graft survival by using three-dimensional printing of intra-abdominal cavity to prevent large-for-size syndrome in liver transplantation.

While large-for-size syndrome is uncommon in liver transplantation (LT), it can result in fatal outcome. To prevent such fatality, we manufactured 3D-printed intra-abdominal cavity replicas to provide intuitive understanding of the sizes of the graft and the patient's abdomen in patients with small body size between July 2020 and February 2022. Clinical outcomes were compared between patients using our 3D model during LT, and patients who underwent LT without 3D model by using 1 : 5 ratio propensity score-matched analysis. After matching, a total of 20 patients using 3D-printed abdominal cavity model and 100 patients of the control group were included in this study. There were no significant differences in 30-day postoperative complication (50.0% vs. 64.0%, p = 0.356) and the incidence of large-for-size syndrome (0% vs. 7%, p = 0.599). Overall survival of the 3D-printed group was similar to that of the control group (p = 0.665), but graft survival was significantly superior in the 3D-printed group, compared to the control group (p = 0.034). Since it showed better graft survival, as well as low cost and short production time, our 3D-printing protocol can be a feasible option for patients with small abdominal cavity to prevent large-for-size syndrome after LT.

Quantifying attributes of boring bivalve populations in corals using micro-computed tomography

Bioerosion plays a crucial factor in shaping the structure and function of coral reef ecosystems, with bioeroders actively altering both the physical and ecological dynamics of coral substrates. Despite their importance, studying internal bioeroders in corals presents significant challenges owing to their cryptic nature within the skeletal structures. Additionally, invasive methods are often required to reveal the subtle and microscopic bioerosive alterations they induce in calcium carbonate substrates. Here, we demonstrate the effectiveness of high-resolution micro-computed tomography (μCT) in quantifying the abundance, size, distribution, and growth directions of coral bioeroders such as cryptic calcareous bivalves in the northern Red Sea. We scanned three coral species inhabited by bioeroders, followed by the utilization of three-dimensional image analysis software to identify, count, and measure each bivalve within the coral skeleton, along with quantifying boring cavity volumes. We revealed that μCT captures small boring cavities (< 1mm), providing more accurate abundance estimates of live and dead boring bivalves than the skeleton decalcification technique, with the added benefits of being rapid and non-destructive in contrast to traditional methods. Furthermore, measurements of empty cavity volumes enabled the estimations of the contribution of bioeroders to the overall coral skeletal porosity. Overall, our study highlights μCT as a practical and effective tool for studying cryptic coral bioeroders, providing novel ecological insights into bioeroder population ecology and coral-bioeroder interactions.

Design of a tunable center frequency and small size cavity bandpass filter by separating capacitor-loaded resonators

This paper presents a tunable center frequency and small size cavity bandpass filter design method. In this method, a capacitor-loaded open terminal coaxial resonator is employed to reduce the size of cavity filters. The resonator is designed and fabricated separately into two parts to achieve the flexible operating frequency purpose. The first part is called the base of the resonator which is simply a pillar and directly fabricated integrally with the cavity housing. The second part called the hat of the resonator is the main part causing the load capacitance in cavity filters. By using different heights of the base part or/and different shapes and sizes of the hat, the operating frequency of cavity filters can be changed flexibly. This method not only reduces the difficulty and cost of cavity filter processing but also makes cavity filters reconfigurable. To demonstrate the effectiveness of the method, a cavity filter sample with a center frequency of 3.45 GHz and a bandwidth of 80 MHz was designed, fabricated, and measured. The measured results show that the insertion loss was smaller than 1.33 dB in the whole bandwidth, one zero-point at 3.350 GHz reaching -68 dB, the rejection at 3.550 GHz was -41 dB, unloaded Q was 5,898, and the dimension of the filter was 128 mm×86 mm×23 mm.

MINDS

Context. The majority of young stars form in multiple systems, the properties of which can significantly impact the evolution of any circumstellar disks. Aims. We investigate the physical and chemical properties of the equal-mass, small-separation (~66 milliarcsecond, ~9 au) binary system DF Tau. Previous spatially resolved observations indicate that only DF Tau A has a circumstellar disk, while DF Tau B does not, as concluded by a lack of accretion signatures and a near-infrared excess. Methods. We present JWST-MIRI MRS observations of DF Tau. The MIRI spectrum shows emission from a forest of H2O lines and emission from CO, C2H2, HCN, CO2, and OH. Local thermodynamic equilibrium slab models were used to determine the properties of the gas. The binary system is not spatially or spectrally resolved in the MIRI observations; therefore, we analyzed high spatial and spectral resolution observations from ALMA, VLTI-GRAVITY, and IRTF-iSHELL to aid in the interpretation of the molecular emission observed with JWST. Results. The 1.3 mm ALMA observations show two equal-brightness sources of compact (R ≲ 3 au) continuum emission that are detected at high significance, with separations consistent with astrometry from VLTI-GRAVITY and movement consistent with the known orbital parameters of the system. We interpret this as a robust detection of the disk around DF Tau B, which we suggest may host a small (~1 au) cavity; such a cavity would reconcile all of the observations of this source. In contrast, the disk around DF Tau A is expected to be a full disk, and spatially and spectrally resolved dust and gas emission traced by ground-based infrared observations point to hot, close-in (≲0.2 au) material around this star. High-temperature emission (~500–1000 K) from H2O, HCN, and potentially C2H2 in the MIRI data likely originates in the disk around DF Tau A, while a cold H2O component (≲200 K) with an extended emitting area is consistent with an origin from both disks. Conclusions. Given the unique characteristics of this binary pair, complementary observations are critical for constraining the properties of these disks. Despite the very compact outer disk properties, the inner disk composition and the conditions of the DF Tau disks are remarkably similar to those of isolated systems, suggesting that neither the outer disk evolution nor the close binary nature are driving factors in setting the inner disk chemistry in this system. However, constraining the geometry of the disk around DF Tau B, via higher angular resolution ALMA observations for instance, would provide additional insight into the properties of the mid-infrared gas emission observed with MIRI. JWST observations of spatially resolved binaries, at a range of separations, will be important for understanding the impact of binarity on inner disk chemistry more generally.

409. TWO-STAGE OPERATIVE PROCEDURE FOR A BENIGN, COMPLICATED TRACHEOESOPHAGEAL FISTULA CAUSED BY FOREIGN BODY IMPACTION

Abstract Background Benign Tracheoesophageal fistula (TOF) caused by foreign body impaction is a rare condition requiring technical expertise. There are choices available based on the individual patient's situation, including endoscopic management, local resection and defect closure, and, in rare cases, esophagectomy. Methods A 58-year-old male had a history of artificial tooth dislodgement that got impacted in the esophagus, resulting in dysphagia. Endoscopy showed an impacted denture with an underlying transmural esophageal perforation, closed with clips and an endoloop. Two weeks later, partially covered SEMS was placed. Failure to retrieve the SEMS after repeated attempts due to tissue ingrowths, he was referred for management. CECT showed a stent in situ with a small air-filled cavity left lateral to the tracheal bifurcation. Bronchoscopy revealed the compression of the posterior tracheal wall and the presence of an endoclip in the posterior wall of the left main bronchus (LMB). Results The patient was planned for a two-stage operation. In the first stage, esophagus was mobilized along with the stent and the fistulous tract was excised. The esophagus was divided at both ends in the thorax. Up to this part, the procedure was done with single-port VATS without CO2 and in the left semi-prone position with a bronchial blocker in the right main bronchus. The fistula with the LMB was closed with an intercostal muscle flap and a bovine pericardial patch with transient apnoea. During this part, we extended the incision in the fourth space to raise the flap. Cervical esophagostomy was matured, and a feeding jejunostomy was created. The postoperative phase was uneventful, and he was discharged on the 5th postoperative day. After 4 weeks, we did the second phase of surgery, where we made a 4 cm retrosternal gastric conduit and performed the hand-sewn anastomosis with the cervical esophagus, which was taken down from the skin. The patient had an uneventful postoperative course and was allowed to be taken orally on day five and discharged subsequently two days later. Conclusions TOF demands a multidisciplinary treatment strategy. Successful outcomes are determined by patient triage, delineation of the location and size of the defect, mediastinal contamination, and the availability of expertise.

Novel mixed matrix membranes containing calixarene for enhanced CO2/N2 separation

Calixarene possessing advantages of small intrinsic cavity size, small particle dimension, and facile dispersion or dissolution in common solvents, is promising filler candidates in mixed matrix membranes (MMMs) for gas separation. Herein, the supramolecular C-propylpyrogallol[4]arene (PgC3) was successfully synthesized via a phenolic resin condensation reaction. It was then incorporated into a polyether-polyamide block copolymer (Pebax-1657) to prepare mixed matrix membranes (MMMs) with varying PgC3 loadings for CO2/N2 separation. The formation of hydrogen bonds between PgC3 and Pebax facilitated the uniform dispersion of PgC3 within the polymer matrix, enhancing interfacial compatibility. The incorporation of PgC3 significantly enhanced the CO2/N2 selectivity of the Pebax while preserving its permeability. The 1 wt% PgC3/Pebax MMMs performs the best CO2/N2 selectivity of 58.6, substantially higher than that of pristine Pebax membrane (32.4). This improvement can be attributed to the strong affinity between the abundant –OH groups in PgC3 and CO2 molecules. Moreover, the PgC3/Pebax MMMs exhibited exceptional stability under operating pressures of up to 5 bar, maintaining its performance consistently throughout a demanding100-hour test. The good separation performance together with the excellent stability enables PgC3 a promising filler in MMMs for CO2/N2 or other gas separations.

The surface tension of Martini 3 water mixtures.

The Martini model, a coarse-grained forcefield for biomolecular simulations, has experienced a vast increase in popularity in the past decade. Its building-block approach balances computational efficiency with high chemical specificity, enabling the simulation of organic and inorganic molecules. The modeling of coarse-grained beads as Lennard-Jones particles poses challenges for the accurate reproduction of liquid-vapor interfacial properties, which are crucial in various applications, especially in the case of water. The latest version of the forcefield introduces refined interaction parameters for water beads, tackling the well-known artifact of Martini water freezing at room temperature. In addition, multiple sizes of water beads are available for simulating the solvation of small cavities, including the smallest pockets of proteins. This work focuses on studying the interfacial properties of Martini water, including surface tension and surface thickness. Employing the test-area method, we systematically compute the liquid-vapor surface tension across various combinations of water bead sizes and for temperatures from 300 to 350K. These findings are of interest to the Martini community as they allow users to account for the low interfacial tension of Martini water by properly adjusting observables computed via coarse-grained simulations to allow for accurate matching against all-atom or experimental results. Surface tension data are also interpreted in terms of local enrichment of the various mixture components at the liquid-vapor interface by means of Gibbs' adsorption formalism. Finally, the critical scaling of the Martini surface tension with temperature is reported to be consistent with the critical exponent of the 3D Ising universality class.

Slit in a Nest Site Influences the Nest Site Selection in Cavity Nesting Ant Colonies.

For ants, nests provide a refuge against predators and protection from environmental factors. Thus, choosing a good nest site is important for an ant colony, but nest sites are limited resources. Ants of the genus Temnothorax inhabit small cavities in, e.g., acorns, twigs and under rocks. Earlier, it was shown that the ants are able to choose a superior site. In this study, using binary choice tests, we studied the nest site selection by Temnothorax crassispinus ant colonies that typically inhabit empty acorns. For this purpose, we used artificial nest sites without and with an additional slit in the nest wall, mimicking the cracks in potential nest sites under natural conditions. We found that the ant colonies preferred artificial nest sites without these slits. However, no difference in the number of colonies inhabited nest sites with a slit vs. those without a slit was found when the slits were closed using transparent food foil, which prevented the air flow while keeping an inflow of light. What is more, additional light through the hole in the red filter covering the artificial nest sites had no influence on the nest site selection. The results of this study suggest that the air flow through a slit in the nest site wall, rather than additional light, influences the nest site selection. The absence of cracks, e.g., in acorns, could be an indication of the durability of potential nest sites. Thus, choosing a cavity without such damage could be beneficial for the ant colonies.