Soft Mesh Research Articles

Three-dimensional quantification of soft tissue changes and its relationship to skeletal changes after Le Fort III, monobloc, and facial bipartition in syndromic craniosynostosis

To determine the effect of midface surgery on soft tissue changes and their relationship to hard tissue changes in patients with syndromic craniosynostosis. A retrospective analysis of patients who had undergone Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB) was conducted. A 3D soft tissue mesh was generated from the preoperative scan and registered to the postoperative scan, after which the advancement was visualised. A total of 68 patients were included: 28 had undergone LFIII, 27 MB, and 13 FB. The included diagnoses were Apert (n = 23), Crouzon (n = 34), and craniofrontonasal syndrome (n = 11). After LFIII, most soft tissue advancement was seen around subnasale and pronasale (mean 15.1 ± 5.9 mm and 14.7 ± 5.7 mm, at age 7–12 years). After MB, a greater hard tissue than soft tissue advancement was seen for most landmarks, showing a high positive correlation. In patients undergoing FB without distraction (n = 10), mean preoperative inter-canthal distance was 48.9 mm, this reduced by 6.9 mm postoperatively. This study provides a comprehensive overview of the outcomes after midface surgery using 3D quantification for a better understanding of the soft tissue changes and their relationship to hard tissue changes.

Simulation of soft tissue deformation under physiological motion based on complementary dynamic method

Background and ObjectivePhysiological motions have a significant impact on soft tissue deformation and accuracy of surgical procedures, which is essential for realistic surgical simulation. While existing studies offer accurate simulation of soft tissue deformation, integrating physiological motions into deformation models of soft tissue remains a challenging task. MethodsThis paper introduces a novel deformation model, based on complementary dynamics, to animate soft tissue deformation under physiological motion. The finite element method is incorporated to accurately characterize the elastic behavior of the soft tissue. Mathematical models of physiological motion are utilized and the physiological effects are converted into displacements of a predefined set of handles within the soft tissue mesh. Complementary displacements derived from the inherent dynamics of the soft tissue are calculated, enabling the simulation of physiological motions and elastic behaviors in soft tissue deformation. ResultsExperiments were conducted to evaluate the performance and effectiveness of the proposed method in simulating soft tissue deformation under physiological motion. The simulation results show that the soft tissues exhibit physiological motion that corresponds to the rhythm of arterial pressure fluctuations, heartbeat or respiratory. Furthermore, the presented method exhibits stable performance compared with existing force-based methods. ConclusionsBoth elastic behaviors and physiological motions of soft tissue deformation can be governed by the proposed method. A high degree of realistic visualization is achieved for virtual surgery simulation.

Hydrophobic modification of mesh spunlace nonwoven for medical dressing contact layer

The contact layer of traditional medical dressing is easy to adhere to the new wound granulation tissue, which brings the deficiency of secondary wound injury. This work assumed that low-cost and soft mesh spunlace nonwoven was used as medical dressing contact layer. After micro-nano SiO2 modification, polydimethylsiloxane (PDMS)/n-heptane were uniformly sprayed on the surface of materials. PDMS modification was studied by using the three-factor three-level orthogonal experiment. The results showed that when the PDMS concentration was 1%, the heat treatment temperature and time were 120°C and 12 h respectively, material possessed the optimal hydrophobicity and its water contact angle (CA) was 151.0 ± 1.1°. Meanwhile, the hydrophobicity, microstructure, thermogravimetry, composition, tensile mechanics, adhesion resistance and durability of materials with/without treatment were compared. It was proved that PDMS was indeed grafted onto the material and could effectively improve the hydrophobicity in coordination with micro-nano SiO2 without affecting the mesh structure of material. The machine direction (MD) and cross-machine direction (CD) strength of material decreased but the elongation increased slightly. The MD and CD peeling energy was 129.7 ± 33.9 J/m2 and 98.1 ± 38.3 J/m2, respectively. Moreover, the water CA of material modified by micro-nano SiO2/PDMS was still 139.4 ± 1.4° after 10 friction stroke tests, indicating that the modified material possessed the great durability. Overall, this study can provide the research basis for the development of anti-adhesion medical dressing contact layer.

Is a soft tissue reinforcing mesh necessary in immediate prosthetic breast reconstruction for early breast cancer in patients with low-volume breast? A single-center, retrospective Chinese clinical study.

It is controversial as to whether soft tissue reinforcement mesh should be used for immediate prosthetic breast reconstruction after nipple-sparing mastectomy for low-volume breast early breast cancer (LVBEBC) in Chinese adult women. We collected data on 89 patients with LVBEBC who underwent such a surgery and divided them into two groups: 39 patients in the totally subpectoral prosthesis-only breast reconstruction group (simple group) and 50 patients in the prosthesis-combined titanium-coated polypropylene mesh (TCPM) group (or the so-called "dual plane" or "mesh-assisted partially subpectoral breast reconstruction group") (combined group). The results demonstrated no difference in operative time, intraoperative bleeding, and postoperative complications between the two groups; however, total drainage volume and extubation time were less and shorter, respectively, in the combined group. The median follow-up time was 18.6months without local recurrence or distant metastasis in both groups. At 24months after surgery, the excellent and good rates of breast reconstruction were higher in the combined group. However, patients' BMI, breast morphology, and breast volume of 300mL or more had an effect on the shape of the reconstructed breast; in addition, in patients with higher BMI, conical breast morphology, and breast volume over 300mL, the shape of the breast was more perfect with the prosthesis combined with TCPM reconstruction.Trial registration: This retrospective study was "retrospectively registered" in the Sixth Affiliated Hospital of South China University of Technology of China on March 15, 2022 (No. 2022018) and in the National Medical Research Registry filing system of China ( https://www.medicalresearch.org.cn ) (No. MR-44-22-003618).

An Electric Self‐Sensing and Variable‐Stiffness Artificial Muscle

Soft robots have better flexibility than their rigid counterparts thus offering greater adaptability to changing environments. These robots made from flexible materials are generally with low stiffness and have limited capability to perform tasks that require the application of large forces. Soft artificial muscles (AMs) with variable stiffness are promising solutions for soft robots to handle larger payloads. However, the existing actuators need to overcome their small range of stiffness variation and slow response. Further, it is difficult to integrate self‐sensing into existing actuators. Herein, a novel electric AM with variable stiffness and self‐sensing referencing smooth muscle contraction in nature is proposed. The AM consists of two pieces of soft anode mesh, a flexible cathode and a polyvinyl chloride (PVC) gel dielectric layer, where the cathode is also a resistive sensor. The stiffness variation is induced by the friction change caused by electrostatic adsorption. Compared with the existing PVC gel actuation technology, the new design integrated the dielectric and the cathode layers and combined the sensing function. Also, the rigid anode and cathode are replaced by the soft ones, respectively, which makes the AM suitable for soft robotics or wearable devices.

PIPER adult comfort: an open-source full body human body model for seating comfort assessment and its validation under static loading conditions.

Introduction: In this paper we introduce an adult-sized FE full-body HBM for seating comfort assessments and present its validation in different static seating conditions in terms of pressure distribution and contact forces. Methods: We morphed the PIPER Child model into a male adult-sized model with the help of different target sources including his body surface scans, and spinal and pelvic bone surfaces and an open sourced full body skeleton. We also introduced soft tissue sliding under the ischial tuberosities (ITs). The initial model was adapted for seating applications with low modulus soft tissue material property and mesh refinements for buttock regions, etc. We compared the contact forces and pressure-related parameters simulated using the adult HBM with those obtained experimentally from the person whose data was used for the model development. Four seat configurations, with the seat pan angle varying from 0° to 15° and seat-to-back angle fixed at 100°, were tested. Results: The adult HBM could correctly simulate the contact forces on the backrest, seat pan, and foot support with an average error of less than 22.3N and 15.5N in the horizontal and vertical directions, which is small considering the body weight (785N). In terms of contact area, peak, and mean pressure, the simulation matched well with the experiment for the seat pan. With soft tissue sliding, higher soft tissue compression was obtained in agreement with the observations from recent MRI studies. Discussion: The present adult model could be used as a reference using a morphing tool as proposed in PIPER. The model will be published openly online as part of the PIPER open-source project (www.PIPER-project.org) to facilitate its reuse and improvement as well as its specific adaptation for different applications.

V06-12 PROPHYLACTIC MESH STRIPS: AN EFFECTIVE WAY TO REDUCE HERNIA DURING RADICAL CYSTECTOMY

You have accessJournal of UrologyCME1 Apr 2023V06-12 PROPHYLACTIC MESH STRIPS: AN EFFECTIVE WAY TO REDUCE HERNIA DURING RADICAL CYSTECTOMY Noah Frydenlund, Eric Li, Clayton Neill, Gergory Dumanian, and Joshua J. Meeks Noah FrydenlundNoah Frydenlund More articles by this author , Eric LiEric Li More articles by this author , Clayton NeillClayton Neill More articles by this author , Gergory DumanianGergory Dumanian More articles by this author , and Joshua J. MeeksJoshua J. Meeks More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003274.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Postoperative hernia development, especially parastomal hernia (PSH), remains a challenging problem after radical cystectomy (RC). The incidence of incisional hernia (IH) has been reported to range from 5-15%, while PSHs occur between 15-65%. The use of prophylactic mesh sheets during RC has been shown to reduce the incidence of PSH in a recent randomized trial. We present our technique for the prophylactic use of soft polypropylene mesh strips as sutures at the time of RC as a potential alternative to mesh sheets and review our early experience. METHODS: A retrospective review of a single surgeon's experience with RC from January 2017 to July 2022 was performed. The inclusion criteria were the use of prophylactic parastomal and/or ventral mesh strips. Patients that required intra-operative assistance from plastic surgery for complex abdominal closure were excluded. Radiographic hernias were identified by radiology reports. Hernias that were noticeable on physical exam, symptomatic, or required operative repair were classified as clinical hernias. RESULTS: A total of 72 patients with prophylactic mesh strip placement during radical cystectomy were included. The average age was 73.5 years (Range 41-88 years), with an average follow of 10.8 months (range 1.1 – 63 months) and an average BMI of 27.9 (range 16.0 – 39.13). Sixty-one patients underwent RC with ileal conduit (IC), while 11 underwent RC with neobladder (NB) creation. 93% of the cases were performed robotically with extracorporeal diversion, and the remainder were open. In the RC with IC cohort, 54 patients had ventral and stomal mesh strips placed while 4 had ventral only and 3 had stomal only strips. Radiographic IH was reported in 6/69 (8.7%) patients with ventral mesh strips. Clinical IH was reported in 2/69 (2.9%) patients. For the RC/IC cohort, radiographic PSH was identified in 11/57 (19.3%) patients, and clinical PSH occurred in 6/57 (10.5%) patients. 2/57 (3.5%) patients underwent parastomal hernia repair, 2/57 (3.5%) developed stomal stenosis, and one patient underwent incisional hernia repair. No mesh-related complications were identified. CONCLUSIONS: The prophylactic use of mesh strips as sutures during RC may provide a safe and effective method to reduce postoperative hernia. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e512 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Noah Frydenlund More articles by this author Eric Li More articles by this author Clayton Neill More articles by this author Gergory Dumanian More articles by this author Joshua J. Meeks More articles by this author Expand All Advertisement PDF downloadLoading ...

Stretchable mesh microelectronics for the biointegration and stimulation of human neural organoids

Advances in tridimensional (3D) culture approaches have led to the generation of organoids that recapitulate cellular and physiological features of domains of the human nervous system. Although microelectrodes have been developed for long-term electrophysiological interfaces with neural tissue, studies of long-term interfaces between microelectrodes and free-floating organoids remain limited. In this study, we report a stretchable, soft mesh electrode system that establishes an intimate in vitro electrical interface with human neurons in 3D organoids. Our mesh is constructed with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based electrically conductive hydrogel electrode arrays and elastomeric poly(styrene-ethylene-butylene-styrene) (SEBS) as the substrate and encapsulation materials. This mesh electrode can maintain a stable electrochemical impedance in buffer solution under 50% compressive and 50% tensile strain. We have successfully cultured pluripotent stem cell-derived human cortical organoids (hCO) on this polymeric mesh for more than 3 months and demonstrated that organoids readily integrate with the mesh. Using simultaneous stimulation and calcium imaging, we show that electrical stimulation through the mesh can elicit intensity-dependent calcium signals comparable to stimulation from a bipolar stereotrode. This platform may serve as a tool for monitoring and modulating the electrical activity of in vitro models of neuropsychiatric diseases.

Surgical site infection after colorectal surgery in China from 2018 to 2020

Objective: This study aims to survey the incidence of surgical site infection (SSI) in China and to analyze its risk factors, so as to prevent and control SSI after colorectal surgery. Methods: An observative study was conducted. Based on a program of Chinese SSI Surveillance from 2018 to 2020, the clinical data of all adult patients undergoing colorectal surgery during this time period were extracted. These included demographic characteristics and perioperative clinical parameters. Minors, pregnant women, obstetric or gynecological surgery, urological system surgery, retroperitoneal surgery, resection of superficial soft tissue masses, and mesh or other implants were excluded. A total of 2122 patients undergoing colorectal surgery from 50 hospitals were included, including 1252 males and 870 females. The median age was 63 (16) years and the median BMI was 23 (4.58) kg/m2. The primary outcome was the incidence of SSI within 30 days after colorectal surgery. The secondary outcomes were mortality within 30 days postoperatively, length of ICU stays and postoperative hospital stays, and cost of hospitalization. Patients were divided into the SSI group and non-SSI group based on the occurrence of SSI. Multivariable logistic regression was performed to analyze risk factors of SSI after colorectal surgery, and subgroup analysis was conducted for open and laparoscopic surgery. Results: The incidence of SSI after colorectal surgery was 5.6% (119/2122), including 47 cases (47/119, 39.5%) with superficial incisional infections, 24 cases (24/119, 20.2%) with deep incisional infections, and 48 cases (48/119, 40.3%) with organ/space infections. The occurrence of SSI significantly increased mortality [2.5% (3/119) vs. 0.1%(3/2003), χ2=22.400, P=0.003], the length of ICU stay [0 (1) day vs. 0(0) day, U=131 339, P<0.001], postoperative hospital stay [18.5 (12.8) days vs. 9.0 (6.0) days, U=167 902, P<0.001], and medical expenses [75 000 (49 000) yuan vs. 60 000 (31 000) yuan, U=126 189, P<0.001] (P<0.05). Multivariate analysis revealed that hypertension (OR=1.782, 95%CI: 1.173-2.709, P=0.007), preoperative albumin level (OR=1.680, 95%CI: 1.089-2.592, P=0.019), a contaminated or infected incision (OR= 1.993, 95%CI: 1.076-3.689, P=0.028), emergency surgery (OR=2.067, 95%CI: 1.076-3.972, P=0.029), open surgery (OR=2.132, 95%CI: 1.396-3.255, P<0.001), and surgical duration (OR=1.804, 95%CI: 1.188-2.740, P=0.006) were risk factors for SSI, while preoperative skin preparation (OR=0.478, 95%CI: 0.310-0.737, P=0.001) was a protective factor for SSI. Subgroup analysis was performed on patients undergoing open or laparoscopic surgery. The incidence of SSI in the open surgery group was 10.2%, which was significantly higher than that in the laparoscopic or robotic group (3.5%, χ2=39.816, P<0.001). Subgroup analysis identified that a contaminated or infected incision (OR=2.168, 95%CI: 1.042-4.510, P=0.038) and surgical duration (OR=2.072, 95%CI: 1.171-3.664, P=0.012) were risk factors for SSI after open surgery, while mechanical bowel preparation (OR=0.428, 95%CI: 0.227-0.807, P=0.009) and preoperative skin preparation (OR=0.356, 95%CI: 0.199-0.634, P<0.001) were protective factors for SSI after open surgery. In laparoscopic surgery, diabetes mellitus (OR= 2.292, 95%CI: 1.138-4.617, P=0.020) and hypertension (OR=2.265, 95%CI: 1.234-4.159, P=0.008) were risk factors for SSI. Conclusions: The incidence of SSI after colorectal surgery is 5.6%. Minimally invasive surgery should be selected to reduce the occurrence of postoperative SSI. To prevent the occurrence of SSI after open surgery, skin preparation and mechanical bowel preparation should be performed before the operation, and the duration of the operation should be shortened as much as possible. In the perioperative period, care of patients with hypertension, diabetes, and contaminated or infected incisions should be given particular attention.

Prevention and management of post-deep inferior epigastric perforator flap abdominal bulge: A 5-year single-surgeon series

Abdominal bulge in the absence of a hernia is a known complication following free abdominal flap breast reconstruction and can be associated with significant aesthetic and functional morbidity. This study aims to review the impact of permanent subrectus mesh placement on the incidence of post-DIEP bulge. All patients over a 5-year period who underwent unilateral or bilateral DIEP breast reconstruction were included in the study. The cohort was divided into a "permanent mesh" (PM) and "no permanent mesh" (NPM) groups. Those in the PM group underwent placement of a permanent Bard™ Soft Polypropylene Mesh, and the NPM group comprised of patients who had a semi-permanent subrectus VyproⓇ mesh or no mesh. The primary outcome of the study was the development of post-DIEP abdominal bulge or hernia. The secondary outcome was the incidence of other donor site complications such as infection. Post-operative follow-up was conducted for a minimum of 6 months. The study included 276 patients, 134 of whom were in the NPM group and 142 in the PM group. Demographics including mean age, median BMI, incidence of pre-operative chemotherapy, radiotherapy, and prior abdominal surgery were comparable between the two groups. The incidence of post-operative abdominal bulge or hernia was lower in the PM group (PM= 0.7% vs. NPM=5.2%, p<0.05). There was no significant difference in the incidence of donor site infection between the two groups (PM=3.5 vs. NPM=2.2%, p=0.53). Our study demonstrates that a low rate of abdominal morbidity can be achieved with the placement of a permanent subrectus mesh.

ОПТИМИЗАЦИЯ УХОДА ЗА ХИРУРГИЧЕСКОЙ РАНОЙ ПОСЛЕ УРЕТРОПЛАСТИКИ У ДЕТЕЙ С ГИПОСПАДИЕЙ

Objectives. To develop optimal postoperative wound care tactics for boys with hypospadias. Methods. The patients (128) with hypospadias aged from 11 months to 7 years were examined. The main group A consisted of 83 (64.8%) patients in whom we used a special bandage. It includes layer by layer of soft polyamide net two-sided onlay coated with soft silicone and adhesive properties, abundantly treated with an antimicrobial ointment containing an osmotic agent, sterile absorbent wipes with non-woven material, a circularly applied elastic bandage and an adhesive plaster with porous non-woven material. The dressing usually held up to 5 days. Group B included 45 (35.2%) patients with hypospadias, in whom we used a conventional sterile circular gauze bandage with antimicrobial ointment. The gauze bandage changed daily. For all clinical symptoms the groups were comparable in age. Postoperative wound healing had been monitored for 10 days after urethroplasty. The emphasis was made on such criteria as bleeding with hematoma formation, copious exudate excretion, penis skin hyperemia, «soft» and «dense» edema, drying crust (scab), skin sutures dehiscence, hypergranulation and necrosis. Results. In group A, problems with the skin flap and postoperative wound were detected only in 17 (20.5%) boys on the second or third day after removal of the special bandage. In the postoperative period, 41 (91.1%) patients in group B had «painful» skin changes in the area of the postoperative wound, which appeared almost the next day after surgery. Conclusion. The use of special bandage delays in time the contact of microbiota penis tissues compromised by surgery and the external environment, which, no doubt, improves the healing of skin grafts in the early postoperative period, and therefore reduces the number of urethroplasty complications. What this paper adds For the first time in patients with hypospadias, the process of postoperative wound healing was analyzed depending on the type of dressing. It was established that the use of a long-term bandage with a soft polyamide mesh doublesided pad with a silicone contact layer and adhesive properties compared to a traditional gauze bandage, which was changed daily, optimized the tactics of postoperative wound care in boys with hypospadias and minimized the number of urethroplasty complications.

Comparison of Hybrid Versus Synthetic Mesh in Robotic Rives-Stoppa Ventral Hernia Repair.

To estimate the average treatment effect on the treated (ATT) and to assess the clinical outcomes in two different types of mesh in robotic Rives-Stoppa (rRS) ventral hernia repair (VHR). A retrospective analysis of a robotic VHR database between February 1, 2013 and May 31, 2022. Patients who underwent a rRS VHR were included in this study and separated into two groups depending on the mesh used: SynecorTM Preperitoneal Biomaterial (SynecorTM Pre) and Bard™ Soft. Through propensity score and inverse-probability-treatment-weighting, the ATT was estimated for two scenarios; the first with the treated target having used the SynecorTM Pre, the second having used the Bard™ Soft mesh. Adjusted linear regression models, including lingering imbalanced variables, were used for both the primary outcome of the Comprehensive Complication Index (CCI®), and the secondary outcome of the hospital cost. A total of 186 patients who underwent rRS were separated into the two groups (SynecorTM Pre mesh, n = 85; Bard™ Soft mesh, n = 101). Adjusted linear regression models for the CCI showed no statistical difference between both groups (p > 0.05), whereas ATT on hospital cost was significantly higher (p < 0.001) in the SynecorTM Pre group in both scenarios [(95% confidence interval) = 3882 (2352, 5413) and -5185 (-8213, -2157), respectively]. Both mesh materials provided excellent outcomes with no difference in complications or recurrence rates. However, hospital cost was found to be higher in the hybrid mesh group. Long-term follow-up is needed to fully assess the performance of both mesh types in rRS.

V01-06 ROBOTIC ASSISTED REPAIR OF A PERINEAL BLADDER HERNIA

You have accessJournal of UrologyIncontinence & Female Pelvic Medicine/Reconstructive Surgery (V01)1 Sep 2021V01-06 ROBOTIC ASSISTED REPAIR OF A PERINEAL BLADDER HERNIA Dmitry Volkin, and Christopher Tarnay Dmitry VolkinDmitry Volkin More articles by this author , and Christopher TarnayChristopher Tarnay More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001970.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Perineal hernias are relatively uncommon but certainly may be encountered by the urologist or pelvic reconstructive surgeon. Diagnosis and management of these unusual hernias is limited to case reports in the literature. Our aim was to provide a video guide demonstrating our technique of how to successfully repair such a hernia. METHODS: This is a video presentation of a 70 year old female patient who developed lower urinary tract symptoms and a palpable mass in her right buttocks. Imaging confirmed a bladder hernia in the right ischiorectal fossa. She underwent repair of her hernia via a robotic assisted abdominal approach, which confirmed a large defect in the levator muscle bordered medially by the vagina and bladder. We also perform a brief review of the literature on perineal hernias and review possible sites of herniation of the bladder. RESULTS: The patient underwent a patch repair of the hernia with soft polypropylene mesh cut to approximately the size of the defect but she recurred 6 weeks later. Repeat operation revealed a medial detachment of her mesh patch. A second repair was performed utilizing a larger piece of mesh, anchoring it more broadly to the levator musculature laterally and pubic bone anteriorly. The patient’s immediate post-operative course was complicated by a retroperitoneal hematoma that was managed conservatively. She was free of hernia recurrence 1 year after her second operation. CONCLUSIONS: Perineal hernias are within the scope of practice of the urologist and pelvic reconstructive surgeon. They can successfully be repaired with reduction of the hernia and application of a broad mesh patch. Source of Funding: Not applicable © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e63-e63 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Dmitry Volkin More articles by this author Christopher Tarnay More articles by this author Expand All Advertisement Loading ...

Computational Modelling of Ceria-Based Solid Oxide Fuel Cell Electrolyte Materials

The significant advances in materials development for solid oxide fuel cells (SOFCs) and modelling techniques have challenged researchers to develop streamlined methodologies aiming at faster and more reliable fabrication of highly efficient cells. Instead of adopting a trial-and-error technique to discover the optimal composition of fuel cell component materials, alternative tools and techniques should be developed for predicting the likely best compositions in a cost-effective and timely manner. Many formulations have been studied for application as SOFC electrolytes over the years and doubly-doped ceria materials have been of considerable recent interest.Here, a simulation methodology to calculate the lattice parameter and the oxygen ion migration energy of ceria-based electrolyte formulations was developed, and the results were analysed and benchmarked against corresponding results obtained experimentally in order to verify the efficacy of the simulation methodology. To this end, a supercell consisting of 2 x 2 x 2 ceria unit cells doubly-doped with samarium and gadolinium was modelled and simulated using molecular mechanics force field methods using the CP2K computational chemistry suite. Two compositional series were modelled with the general formula Ce32-(x+y)SmxGdyO64-(x+y)/2 where x and y are the number of samarium and gadolinium dopant atoms per supercell respectively. The first compositional series, Series One, had equal amounts of dopants but different total dopant concentration with values of x = y = 1, 2, 8, or 16. Series Two had a fixed total dopant concentration (x + y = 8) but different amounts of each dopant in each structure such that x had integer values from 0 to 8 (x = 0 ... 8) and y = 8 - x. Moreover, two doping strategies were simulated for each compositional series depending on how the dopant atoms and resulting vacancies were distributed throughout the crystal. The first doping strategy places one dopant atom in two or more of the eight minicubes comprising the 2 x 2 x 2 supercell for Series One structures and, for Series Two structures, one dopant atom is placed in each minicube starting with one gadolinium atom in each minicube and then progressively replacing one gadolinium atom with one samarium atom in each of the subsequent structures of this series until there is one samarium atom in each minicube. The second doping strategy places the dopants exclusively in the four minicubes that let the dopants be as far as possible from each other. In all cases, the oxygen vacancies are chosen to be the nearest neighbours, i.e., in the nearest lattice positions, to the dopant atoms.For each structure, the lattice parameter was calculated using a cell optimisation technique utilizing the conjugate gradient method where the soft particle mesh Ewald (SPME) sums method and the DIPole Polarizable Ion Model (DIPPIM) for the long- and short-range potentials respectively. To estimate the activation energies associated with hopping of an oxygen ion from a specific site to a neighbouring site in the structures studied, the following steps were applied: The positions of the dopant atoms in the pure crystal were assigned.The at a distance within 3.0 Å was generated.The climbing image nudged elastic band (CI-NEB) method was applied to determine all the activation barriers of the doped crystal.The average energy barrier was calculated. The results obtained for the lattice parameter were comparable to those observed experimentally and exhibited the same linear trends satisfying Vegard's law, albeit the trend for the fixed dopant concentration series had a slight negative slope. Simulation-derived values of the activation energy showed the same trends as those observed experimentally. The simulations also produced transition state curves showing the saddle point and energy minima for each structure; information that could not be obtained experimentally and that can shed some light on the mechanism of ionic conduction. It was found that the position of oxygen vacancies within the crystal structure play a key role in determining the activation energy of ion hopping, and that the different patterns of doping do not affect the overall trends in lattice parameter and activation energy. They do however produce different patterns in the energy profiles contributing to the energy barriers to ion hopping within the crystal structure.This work demonstrates that computational simulations of SOFC electrolyte materials provide results comparable with those obtained experimentally and could also provide insights into the mechanisms of ionic conduction. The incongruence of the computational and experimental results was attributed to the limitations of the molecular mechanics force field methodology utilised, with the expectation that an ab initio density functional theory (DFT) calculation would yield closer conformance. Figure 1

Preliminary evaluation of the short-term outcomes of polytetrafluoroethylene mesh for pelvic organ prolapse.

Tension-free vaginal mesh (TVM) surgery using synthetic polypropylene (PP) soft mesh had spread rapidly. However, the frequency of mesh-related postoperative complications had increased, and PP was banned in April 2019. In Japan, however, transvaginal surgery using polytetrafluoroethylene (PTFE) mesh had been approved. In this study, we evaluated the clinical outcome and quality of life (QOL) of the postoperative course using PP mesh and PTFE mesh (named "ORIHIME™" ) in a combination surgery for utero-sacral ligament suspension and anterior vaginal support using anterior TVM. The vaginal hysterectomy and utero-sacral ligament colpopexy augmented by anterior vaginal mesh implants using PP mesh and PTFE mesh were performed on patients with stage III to IV cystocele and uterine prolapse. The clinical outcome and QOL changes in their postoperative course were evaluated by comparing 15 cases of PP mesh and 13 cases of PTFE mesh. There was no difference between the PP group and PTFE group in characteristics. No mesh-related complications occurred during the follow-up period. With regard to the pelvic organ prolapse quantification (POP-Q) score, no significant difference was found between the two groups. Comparing the postoperative QOL of both groups, the PTFE group had significantly higher values in two domains than PP group (SF-12v2 questionnaire). We used the world's first PTFE mesh to compare PP mesh with postoperative POP-Q and QOL after the same surgery, with the same operator, and at the same institution. The results showed no significant difference between both mesh materials in the short-term.

A soft elastomer alternative to polypropylene for pelvic organ prolapse repair: a preliminary study.

We compared the impact of a mesh manufactured from the soft elastomer polydimethylsiloxane (PDMS) to that of a widely used lightweight polypropylene (PP) mesh. To achieve a similar overall device stiffness between meshes, the PDMS mesh was made with more material and therefore was heavier and less porous. We hypothesized that the soft polymer PDMS mesh, despite having more material, would have a similar impact on the vagina as the PP mesh. PDMS and PP meshes were implanted onto the vaginas of 20 rabbits via colpopexy. Ten rabbits served as sham. At 12weeks, mesh-vagina complexes were explanted and assessed for contractile function, histomorphology, total collagen, and glycosaminoglycan content. Outcome measures were compared using one-way ANOVA and Kruskal-Wallis testing with appropriate post-hoc testing. Relative to sham, vaginal contractility was reduced following the implantation of PP (p = 0.035) but not the softer PDMS (p = 0.495). PP had an overall greater negative impact on total collagen and glycosaminoglycan content, decreasing by 53% (p < 0.001) and 54% (p < 0.001) compared to reductions of 35% (p = 0.004 and p < 0.001) with PDMS. However, there were no significant differences in the contractility, collagen fiber thickness, total collagen, and glycosaminoglycan content between the two meshes. Despite having a substantially higher weight, PDMS had a similar impact on the vagina compared to a low-weight PP mesh, implicating soft polymers as potential alternatives to PP. The notion that heavyweight meshes are associated with a worse host response is not applicable when comparing across materials.

Hexagonal cluster Mn-MOF nanoflowers with super-hydrophilic properties for efficient and continuous solar-driven clean water production

Superhydrophilic, robust, hexagonal prism cluster Mn-MOF nanoflowers with superior solar thermal conversion performance are grown on surface of soft copper mesh as a conformal and uniform coating for a stable, portable and efficient solar evaporator.

Comparison between the composite heavy weight prolene mesh versus the prolene soft mesh for the reduction in post-operative pain in patients undergoing lichensteins mesh repair for inguinal hernias

Background: Globally, inguinal hernia is the most common type of hernia, comprising of approximately 75% of all abdominal wall hernias.Aim of the study was to compare the heavyweight composite polypropylene mesh versus the prolene soft mesh for the reduction of post-operative pain in patients undergoing lichensteins mesh repair for inguinal hernia.Methods: This study was conducted in the Department of General Surgery, KLES Dr. Prabhakar Kore Hospital and Medical Research Centre, Belgaum attached to KLE University’s J.N.M.C Belgaum.Results: Male preponderance was seen with 96.67% of patients in group SP and all (100%) patients in group RP were males. The mean age in group SP was 51.93±18.73 years compared to 49.50±14.03 years in group RP (p=0.571). The mean duration of the disease was 12.67±9.85 months in group SP whereas in group RP it was 15.10±8.98 months (p=0.321). The mean pulse rate in group SP and RP (79.60±5.64 vs 82.37±5.46 /min; p=0.059), systolic blood pressure (120.33±9.99 vs 124.33±11.94 mmHg; p=0.165) and diastolic blood pressure (73.73±6.76 vs 75.80±8.59 mmHg; p=0.305) were comparable. Right position was noted in 56.67% of patients in group SP compared to 50% of patients in group RP (p=0.673).Conclusions: Prolene soft mesh (lightweight macro-porous polypropylene mesh) significantly reduced the post-operative pain in patients undergoing lichensteins mesh repair for inguinal hernia as compared to heavyweight composite polypropylene mesh.

Reconstruction of the chest wall in locally advanced breast cancer with multi-disciplinary cooperation: a case report of mesh repair plus TRAM combined with DIEP chest wall reconstruction

Locally advanced breast cancer, which is defined as a malignant breast tumor that invades or adheres to the surrounding tissue, is characterized by the invasion of the chest wall and the skin surface by the tumor. Multiple lymph nodes are invaded and fuse into a mass, causing extensive axillary lymph node metastasis. However, locally advanced breast cancer does not exhibit distant metastasis. At present, in most hospitals in China and the rest of the world, this type of breast cancer is primarily managed through systematic and local treatments. However, a consensus concerning the optimal surgical method for chest wall reconstruction, which for many surgeons is a difficult and confusing procedure, has not been reached. In the past, many breast centers had used skin flap combined with hard mesh titanium alloy plate to repair the large chest wall defects. Although titanium alloy plate can maintain the stability of the chest wall, it may have a negative effect on the follow-up radiotherapy of breast cancer patients, which is a controversial method. In addition, titanium alloy mesh also has the risk of deformation and fracture. These factors will cause some hidden dangers to patient safety. According to the research, the soft mesh not only has the characteristics of satisfactory compatibility and robustness for maintaining the stability of chest wall, but also does not affect the postoperative radiotherapy of patients. Combined with the advantages of soft mesh, Our department treated a case of locally advanced breast cancer with chest wall invasion. Through cooperation between the breast surgery and thoracic surgery departments, a mesh repair plus transverse rectus abdominis myocutaneous (TRAM) combined with deep inferior epigastric perforator (DIEP) procedure was performed to remove the breast tumor and repair the large area of skin defect after surgery, and a relatively satisfactory therapeutic effect was achieved. In this case, we took two novel approaches: first, a 4-layer high-density polyethylene mesh was used to repair the defect; secondly, the inferior epigastric artery perforation was anastomosed with the thoracoacromial artery (end-to-end anastomosis) and the inferior epigastric vein perforation was anastomosed with the axillary vein (end-to-side anastomosis).

Analysis of resorbable mesh implants in short-term human muscular fascia cultures: a pilot study

PurposeAlteration in fascial tissue collagen composition represents a key factor in hernia etiology and recurrence. Both resorbable and non-resorbable meshes for hernia repair are currently used in the surgical setting. However, no study has investigated so far the role of different implant materials on collagen deposition and tissue remodeling in human fascia. The aim of the present study was to develop a novel ex vivo model of human soft tissue repair mesh implant, and to test its suitability to investigate the effects of different materials on tissue remodeling and collagen composition.MethodsResorbable poly-4-hydroxybutyrate and non-resorbable polypropylene mesh implants were embedded in human abdominal fascia samples, mimicking common surgical procedures. Calcein-AM/Propidium Iodide vital staining was used to assess tissue vitality. Tissue morphology was evaluated using Mallory trichrome and hematoxylin and eosin staining. Collagen type I and III expression was determined through immunostaining semi-quantification by color deconvolution. All analyses were performed after 54 days of culture.ResultsThe established ex vivo model showed good viability at 54 days of culture, confirming both culture method feasibility and implants biocompatibility. Both mesh implants induced a disorganization of collagen fibers pattern. A statistically significantly higher collagen I/III ratio was detected in fascial tissue samples cultured with resorbable implants compared to either non-resorbable implants or meshes-free controls.ConclusionWe developed a novel ex vivo model and provided evidence that resorbable polyhydroxybutyrate meshes display better biomechanical properties suitable for proper restoration in surgical hernia repair.