32 research outputs found

    Laparoscopic anterior gastropexy for chronic recurrent gastric volvulus: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Gastric volvulus is an uncommon clinical entity, first described by Berti in 1866. It is a rotation of all or part of the stomach through more than 180°. This rotation can occur on the longitudinal (organo-axial) or transverse (mesentero-axial) axis. This condition can lead to a closed-loop obstruction or strangulation. Traditional surgical therapy for gastric volvulus is based on an open approach. Here we report the case of a patient with chronic intermittent gastric volvulus who underwent a successful laparoscopic treatment.</p> <p>Case presentation</p> <p>A 34-year-old woman presented with multiple episodes of recurrent upper abdominal pain associated with retching and vomiting, treated unsuccessfully with intramuscular metoclopramide. Endoscopic examination of the upper digestive tract showed a suspected rotation of the stomach, and a chronic recurrent gastric volvulus was revealed by barium meal. The patient was operated on successfully, with an anterior laparoscopic gastropexy performed as the first surgical approach.</p> <p>Conclusion</p> <p>Experience with laparoscopic anterior gastropexy is limited only to a few described cases. Our patient was clinically and radiologically followed-up for 2 years with no evidence of recurrence, either radiological or symptomatic. Based on this result, laparoscopic gastropexy can be seen and considered as an initial 'gold standard' for the treatment of gastric volvulus.</p

    Omental whirl associated with bilateral inguinal hernia: a case report

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    INTRODUCTION: Torsion of the omentum is a rare cause of abdominal pain. It is clinically similar to common causes of acute surgical abdomen and is often diagnosed during surgery. Inguinal hernia is a common condition but not frequently related with torsion of the omentum. CASE PRESENTATION: A 40-year-old Caucasian man came to our emergency department with abdominal pain of the left quadrant and abdominal distension for 2 days. His medical history included an untreated left inguinal hernia in the last year. Computed tomography revealed densification of mesocolon with left omentum "whirl" component and other signs of omental torsion. During an exploratory laparoscopy, a wide twist of his omentum with necrotic alterations that extended to the bilateral inguinal hernial content was observed. Omentectomy and surgical repair of bilateral inguinal hernia were performed. CONCLUSIONS: Torsion of the omentum is a rare entity and usually presents a diagnostic challenge. The use of abdominal computed tomography can help diagnosing torsion of the omentum preoperatively and, thus, prevents a surgical approach. Nonetheless, some cases of torsion of the omentum require surgical repair. Accordingly, a laparoscopic approach is minimally invasive and efficient in performing omentectomy.(undefined

    Unsaturated phosphatidylcholines lining on the surface of cartilage and its possible physiological roles

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    Background Evidence has strongly indicated that surface-active phospholipid (SAPL), or surfactant, lines the surface of cartilage and serves as a lubricating agent. Previous clinical study showed that a saturated phosphatidylcholine (SPC), dipalmitoyl-phosphatidylcholine (DPPC), was effective in the treatment of osteoarthritis, however recent studies suggested that the dominant SAPL species at some sites outside the lung are not SPC, rather, are unsaturated phosphatidylcholine (USPC). Some of these USPC have been proven to be good boundary lubricants by our previous study, implicating their possible important physiological roles in joint if their existence can be confirmed. So far, no study has been conducted to identify the whole molecule species of different phosphatidylcholine (PC) classes on the surface of cartilage. In this study we identified the dominant PC molecule species on the surface of cartilage. We also confirmed that some of these PC species possess a property of semipermeability. Methods HPLC was used to analyse the PC profile of bovine cartilage samples and comparisons of DPPC and USPC were carried out through semipermeability tests. Results It was confirmed that USPC are the dominant SAPL species on the surface of cartilage. In particular, they are Dilinoleoyl-phosphatidylcholine (DLPC), Palmitoyl-linoleoyl-phosphatidylcholine, (PLPC), Palmitoyl-oleoyl-phosphatidylcholine (POPC) and Stearoyl-linoleoyl-phosphatidylcholine (SLPC). The relative content of DPPC (a SPC) was only 8%. Two USPC, PLPC and POPC, were capable of generating osmotic pressure that is equivalent to that by DPPC. Conclusion The results from the current study confirm vigorously that USPC is the endogenous species inside the joint as against DPPC thereby confirming once again that USPC, and not SPC, characterizes the PC species distribution at non-lung sites of the body. USPC not only has better anti-friction and lubrication properties than DPPC, they also possess a level of semipermeability that is equivalent to DPPC. We therefore hypothesize that USPC can constitute a possible addition or alternative to the current commercially available viscosupplementation products for the prevention and treatment of osteoarthritis in the future

    Lawson criterion for ignition exceeded in an inertial fusion experiment

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    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    Effects of wall conduction and rarefaction on shock propagation in a micro-channel

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    A Direct Simulation Monte Carlo code is coupled with a continuum unsteady conduction finite volume code to study the effects of wall conduction on shock propagation in a micro-channel. In addition, the effects of rarefaction and wall accommodation are also investigated. Wall accommodation is seen to influence the shock attenuation more significantly than wall conduction. The results indicate that both the shock front Mach number and shock strength are comparatively higher in case of adiabatic wall condition as there is no loss of energy from the shocked region. At higher rarefaction, the effect of wall accommodation as well as that of wall conduction are seen to become more noticeable. The simulation results show that it is not necessary to exactly model the wall conduction heat transfer for studying shock attenuation, and the two limiting situations of isothermal and adiabatic approximations are satisfactory as the thermal wall boundary conditions

    A hybrid MD-DSMC coupling method to investigate flow characteristics of micro-devices

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    A new methodology is proposed to couple Molecular Dynamics (MD) and Direct Simulation Monte Carlo (DSMC) methods to simulate high Knudsen number (Kn) flows. For this purpose a two-dimensional hybrid MD-DSMC code is developed. In this method gas-surface interactions are modeled using MD, and gas-gas interactions are modeled using DSMC method. Two-way coupling between MD and DSMC is implemented by employing buffer zones for both MD and DSMC regions. Bootstrap sampling and energy minimization algorithms are employed for dynamic coupling of these two methods since MD utilizes real number of molecules during simulation whereas DSMC utilizes a lesser number of simulated molecules. The hybrid methodology combines the advantages of both methods; it has the capability of modeling the gas-surface interaction accurately considering the effect of the presence of neighboring real number of gas molecules, while in the bulk it utilizes DSMC with only the simulated number of molecules thus increasing the computational efficiency significantly compared to pure MD codes. As a result comparatively large domain sizes can be simulated with realistic behavior at the walls. The utility of the hybrid method is demonstrated by simulating high Kn flows through a micro-channel, micro-nozzle and micro-scale shock tube. The effect of partial accommodation of gas molecules with the wall is seen to be captured dynamically with this approach. (C) 2015 Elsevier Inc. All rights reserved

    Modeling wall effects in a micro-scale shock tube using hybrid MD-DSMC algorithm

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    Wall effects in a micro-scale shock tube are investigated using the Direct Simulation Monte Carlo method as well as a hybrid Molecular Dynamics-Direct Simulation Monte Carlo algorithm. In the Direct Simulation Monte Carlo simulations, the Cercignani-Lampis-Lord model of gas-surface interactions is employed to incorporate the wall effects, and it is shown that the shock attenuation is significantly affected by the choice of the values of tangential momentum accommodation coefficient. A loosely coupled Molecular Dynamics-Direct Simulation Monte Carlo approach is then employed to demonstrate incomplete accommodation in micro-scale shock tube flows. This approach uses fixed values of the accommodation coefficients in the gas-surface interaction model, with their values determined from a separate dynamically similar Molecular Dynamics simulation. Finally, a completely coupled Molecular Dynamics-Direct Simulation Monte Carlo algorithm is used, wherein the bulk of the flow is modeled using Direct Simulation Monte Carlo, while the interaction of gas molecules with the shock tube walls is modeled using Molecular Dynamics. The two regions are separate and coupled both ways using buffer zones and a bootstrap coupling algorithm that accounts for the mismatch of the number of molecules in both regions. It is shown that the hybrid method captures the effect of local properties that cannot be captured using a single value of accommodation coefficient for the entire domain

    Investigation of Wall Effects on Flow Characteristics of a High Knudsen Number Nozzle

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    Two-dimensional direct simulation Monte Carlo (DSMC) was used to investigate the effect of wall accommodation on different modes of operation of a nozzle under high Knudsen number conditions. Substantial performance enhancement was seen at higher values of convergingdiverging angles, because a reduction in the surface area-to-volume ratio decreased the wall effects. Though the normal energy accommodation had a negligible influence on the nozzle performance, it was seen to be a critical factor for accurate prediction of gas temperature along the wall. At higher Knudsen numbers, the flow tended to become one-dimensional even for the case of complete accommodation
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