Endoscopic vacuum assisted closure therapy for esophagopericardial fistula in a 16-year-old male:A case report

BACKGROUND Esophagopericardial fistula(EPF)is a rare,life-threatening condition with limited scientific literature and no established management guidelines.This case report highlights a successful multidisciplinary approach and the innovative use of endoscopic vacuum assisted closure(endoVAC)therapy in treating this complex condition.CASE SUMMARY A 16-year-old male with a history of esophageal atresia and colon interposition presented with progressive chest pain,fever,and dyspnea.Imaging revealed an EPF with associated pleural and pericardial effusions.Initial management with an esophageal stent failed,prompting the use of an endoVAC system.The patient underwent multiple endoVAC device changes and received broad-spectrum antibiotics and nutritional support.The fistula successfully closed,and the patient recovered,demonstrating no new symptoms at a 6-month follow-up.CONCLUSION EndoVAC therapy can effectively manage EPF,providing a minimally invasive treatment option.

Characterization of A390 aluminum alloy produced at different slow shot speeds using vacuum assisted high pressure die casting

The effects of vacuum assistance on the microstructure and mechanical properties of high pressure die cast A390alloy at different slow shot speeds were evaluated.Plate-shaped specimens of hypereutectic A390aluminum alloy were produced on a TOYO BD?350V5cold chamber die casting machine incorporated with a self-improved TOYO vacuum system.According to the results,the vacuum pressure inside the die cavity increased linearly with the increasing slow shot speed at the beginning of mold filling.Meanwhile,tensile properties of vacuum die castings were deteriorated by the porosity content.In addition,the average primary silicon size decreased from23to14μm when the slow shot speed increased from0.05to0.2m/s,which has a binary functional relationship with the slow shot speed.After heat treatment,microstructural morphologies revealed that needle-shaped and thin-flaked eutectic silicon particles became rounded while Al2Cu dissolved intoα(Al)matrix.Furthermore,the fractography revealed that the fracture mechanism has evolved from brittle transgranular fracture to a fracture mode with many dimples after heat treatment.

Endoscopic vacuum assisted closure of esophagogastric anastomosis dehiscence:A case report

BACKGROUND Esophagogastric leakage is one of the most severe postoperative complications.Partial disruption of the anastomosis,can be successfully treated with an endoscopic vacuum assisted closure(E-VAC).The advantage of that method of treatment is the ability to adjust a vacuum dressing individually to the size of the dehiscence and thus to reduce the risk of a secondary fistula or abscess.The authors present two patients with postoperative gastroesophageal leakage treated successfully with E-VAC.CASE SUMMARY Two male patients developed a potentially life threatening esophagogastric leakage.Patient A underwent resection of the distal half of the esophagus and upper part of the stomach due to Siewert type II adenocarcinoma of the gastroesophageal junction.Proximal resection of the stomach was performed in the patient B after massive bleeding from Mallory-Weiss tears.Both patients were treated successfully with an individually adapted E-VAC with concomitant correction of fluid and electrolyte disturbances,and treatment of sepsis with appropriate antibiotics.CONCLUSION Endoscopic vacuum closure is an effective alternative to endoscopic stenting or relaparotomy.Through individual approach it allows a more accurate assessment of healing.

Formulating Novel Halogen-Free Synergistic Flame Retardant Epoxy Resins for Vacuum Assisted Resin Infusion Composites

The most common process to manufacture advanced composites is the costly autoclave.One of the out-of-autoclave alternatives is the low-cost vacuum assisted resin infusion(VARI)which produces quality parts with less pollution.Epoxy resin is a widely used composite matrix resin,but its high flammability limits its use as interior composite parts for vehicles.The usual flame retardant for epoxy involves halogen,which is effective but has high smoke toxicity.As a result,halogen-free flame retardant epoxy resin systems become dominant.In this paper,phosphorus flame retardant was combined with benzoxazine(BOZ)to produce synergistic effect and achieve satisfactory flame retardance,as well as mechanical improvement for the epoxy resin.Differential scanning calorimetry(DSC),dynamic mechanical analysis(DMA),thermal gravitational analysis(TGA),the cone calorimeter(CC),and limiting oxygen index(LOI)were used to characterize the resins.The results showed significant improvement on the flame retardance of the synergistically modified resins.Specifically,the carbon residue increased by 113.6%,and the char thickness increased by 6 to 7 times,compared to those of the flammable benchmark resin.The LOI reached 33 and passed the UL94 V-0 vertical burn rating.The modified resins also exhibited adequate stability and viscosity suitable for VARI processes.

Investigation of carbon fiber composite stiffened skin with vacuum assisted resin infusion/prepreg co-curing process

Co-cured vacuum assisted resin infusion process(co-VARI process),which combined vacuum assisted resin infusion(VARI)with prepreg vacuum bag only process(VBO),was adopted to fabricate T-shaped stiffened skin with non-crimp fabric(NCF)stiffener and prepreg skin.During compaction stage of co-VARI process,prepreg resin impregnated fiber fabric under elevated temperature and vacuum pressure.This phenomenon was characterized by fluorescent micrographs with different holding temperature and time.Its influences on processing quality and mechanical performance for co-VARI stiffened skin with different filler materials at triangular region were further analyzed by optical micrographs and pull-off test,respectively.The results show that increasing holding temperature and prolonging holding time can promote prepreg resin impregnation in fiber fabric.Moderate prepreg resin impregnation is favorable to reduce resin rich region and increase fiber volume fraction at prepreg-fabric interface.Moreover,prepreg resin impregnation effect plays significant roles on pull-off performance for co-VARI stiffened skin with fabric filler but has negligible influences on specimens with prepreg filler.In addition,compared with stiffened skin with fabric filler,superior processing quality and pull-off performances are achieved for co-VARI stiffened skin with prepreg core filler.These results are helpful to optimize processing procedures and fabricate composite structure by coVARI process.

Utility of an upright-type 11-gauge stereotactic vacuum-assisted biopsy device (Mammotome) for the diagnosis of breast microcalcifications

Objective: The aim of this study was to evaluate the utility of an upright-type 11-gauge stereotactic vacuumassisted biopsy device (Mammotome) for the diagnosis of breast microcalcifications Methods: Between May 2001 and October 2005, 154 biopsies in 152 patients with microcalcifications were performed using the upright-type 11-gauge stereotactic vacuum-assisted biopsy device. Patients in whom this biopsy was diagnosed as carcinoma or a borderline lesion, had a subsequent surgical excision of the lesion. Histopathological and radiological features of the two specimens were then compared with each other. Results: Microcalcification was identified on specimen mammograms and microscopic slides in 97.4% of cases. Of 154 Mammotome biopsies 98 (63.6%) were benign, 51 (33.1%) were malignant, 3 (1.9%) showed atypical hyperplasia, and 2 (1.3%) were indeterminate, respectively. Of the 48 cases that received surgical excision, 6 of 36 ductal carcinomas in situ (16.7%) upstaged to invasive ductal carcinoma and 1 of 2 atypical ductal hyperplasias was upstaged to ductal carcinoma in situ. The positive predictive value of the 11-gauge Mammotome for the diagnosis of invasion in breast cancer was 100%. Linear calcification and pleomorphic calcification linear/segmental distribution was reliable indications of malignancy. The mean follow-up time of the benign lesions was 22 months, and without evidence of lesion growth. Complications included vasovagal reactions (6.3%), bleeding (0.6%) and hematoma (2.6%). Conclusion: The upright stereotactic 11-gauge Mammotome procedure is an effective and reliable method for the diagnosis of breast microcalcifications. It has minimal side effects. For lesions diagnosed as ADH or DCIS with the 11-gauge Mammotome, subsequent surgical excision should be performed.

Successful resolution of gastric perforation caused by a severe complication of pancreatic walled-off necrosis:A case report

BACKGROUND Pancreatic walled-off necrosis(WON)rarely causes critical gastric necrosis and perforation,which may develop when pancreatic WON squashes against the stomach.The Atlanta 2012 guidelines were introduced for acute pancreatitis and its related clinical entities.However,there are few reported cases describing the clinical course and resolution of pancreatic WON.CASE SUMMARY We report the case of a 45-year-old man who presented to the urgent emergency department with gastric perforation caused by a severe complication of pancreatic WON on computed tomography.The patient underwent an emergency distal pancreatectomy,splenectomy,and gastric wedge resection.Postoperative findings showed re-perforation of the gastric wall at a previously resected margin.Furthermore,endoscopic examination revealed an ulcerative area with a defect in the fundus.After diagnostic endoscopy,endoscopic vacuum-assisted closure was performed,and continuous suction was transferred over all tissues in contact with the sponge surface.The patient recovered without any further complications and was discharged in good condition at postoperative week 8.No recurrence occurred during the 6-mo follow-up period.CONCLUSION When managing a patient with serious gastric perforation complicated by pancreatic WON,a multidisciplinary treatment approach should be considered.

Prediction of the Enhanced Out-of-Plane Thermal Conductivity of Carbon Fiber Composites Produced by VARTM

The thermal conductivity of epoxy resin can be increased by a factor of eight to ten by loading with highly conductive particles. However, higher loadings increase the viscosity of the resin and hamper its use for liquid composite molding processes. Thus, the enhancement of the out-of-plane thermal conductivity of carbon composites manufactured by VARTM and accomplished by matrix filling is limited to about 250%. In order to derive higher increases in out-of-plane thermal conductivity, additional measures have to be taken. These consist of introducing thermally conductive fibers in out-of-plane direction of the preform using a 3D-weaving process. Measured out-of-plane thermal conductivities of 3D-woven fabric composites are significantly increased compared to a typical laminated composite. It has been shown that if introducing highly conductive z-fibers, the use of a particle filled resin is not necessary and furthermore should be avoided due to the manufacturing problems mentioned above. An existing analytical model was altered to predict the effective thermal conductivity as a function of the composite material properties such as the thermal conductivities and volume contents of fibers in in-plane and out-of-plane directions, the thermal conductivity of the loaded resin, the grid-density of the out- of-plane fibers, and material properties of the contacting material. The predicted results are compared with measured data of manufactured samples.

Clinical evidences, personal experiences, recent applications

Management of difficult wounds can be a complex,challenging and expensive task,especially for wounds showing a slow healing process.Topical negative pressure(TNP)therapy has greatly improved difficult wounds treatment.It allows to treat patient on an outpatient management,to reduce the complication rate with shorter hospital stay,to avoid frequent dressings with expensive advanced materials and allow a lower commitment of health professionals.Vacuum Assisted Closure(VAC)system is a therapeutic device based on the administration of a controlled TNP introduced by Morykwas and Argenta in 1997.It is indicated in different kinds of wound,but clinical evidences are present only for few of them.In this work we summarize indications and recommendations for VAC therapy and we analyze the actual better choice of treatment based on evidences and personal experience in order to stimulate further studies.Finally we introduce recent applications of VAC system such as Prevena,VAC Instill and VAC Via Prevena is a system based on TNP indicated in the management of closed wounds that present risk factors for dehiscence.VAC Instill is a system that allows to associate TNP and topical administration of solutions,such as antibiotics or disinfectants,to treat specific type of wounds.VAC Via is a device based on TNP,characterized by little dimen-sion and a preset system that allow the treatment of little wounds for 7 d,with no impairment for the patient.The aim of our paper is to describe a report of VAC therapy use in order to stimulate further studies and to define the level of evidence of VAC therapy.

Copper nanowires decorated with TiO_(2−x) from MXene for enhanced electrocatalytic nitrogen oxidation into nitrate under vacuum assistance

The green synthesis of nitrate(NO_(3)^(−))via electrocatalytic nitrogen oxidation reaction(NOR)is a promising strategy for artificial nitrogen fixation,which shows great advantages than traditional nitrate synthesis based on Haber–Bosch and Ostwald processes.But the poor N_(2)absorption,high bond energy of N≡N(941 kJ·mol^(−1)),and competing multi-electron-transfer oxygen evolution reaction(OER)limit the activity and selectivity.Herein,we fabricated MXene-derived irregular TiO_(2)−x nanoparticles anchored Cu nanowires(Cu-NWs)electrode for efficient electrocatalytic nitrogen oxidation,which exhibits a NO_(3)−yield of 62.50μg·h^(−1)·mgcat^(−1)and a Faradaic efficiency(FE)of 22.04%,and a significantly enhanced NO_(3)−yield of 92.63μg·h^(−1)·mgcat^(−1),and a FE of 40.58%under vacuum assistance.The TiO_(2)−x/Cu-NWs electrode also shows excellent reproducibility and stability under optimal experimental conditions.Moreover,a Zn-N_(2)reaction device was assembled with TiO_(2−x)/Cu-NWs as an anode and Zn plate as a cathode,obtaining an extremely high NO_(3)−yield of 156.25μg·h^(−1)·mgcat^(−1).The Zn-nitrate battery shows an open circuit voltage(OCV)of 1.35 V.This work provides novel strategies for enhancing the performance of ambient N_(2)oxidation to obtain higher NO_(3)^(−)yield.

Effect of Bio-filler on Hybrid Sisal-Banana-Kenaf-Flax Based Epoxy Composites:A Statistical Correlation on Flexural Strength

This work deals with the investigation of the synergistic effect of bagasse ash with sisal-banana-kenaf-flax fibers reinforced epoxy composite for their flexural behavior.The composites with three combinations of hybrid fibers viz.sisal/kenaf(HSK),banana/kenaf(HBK),and banana/flax(HBF)with bagasse ash(BGA)as filler material are fabricated using vacuum bag assisted resin transfer molding.Experiments were conducted based on L27 orthogonal array to understand the influence of control factor viz.fiber volume,alkali concentration&BGA over output response.A'-ray micro computed tomography analysis was conducted over the developed sample to infer the uniform dispersion of fiber and filler material.The experimental results reveal that the addition of fiber up to 30 vol%depicts better strength and further addition results in a negative impact.Increasing in order of BGA decreases the flexural strength of the developed composites.