Status Quo on Graphene Electrode Catalysts for Improved Oxygen Reduction and Evolution Reactions in Li-Air Batteries.

Reduced global warming is the goal of carbon neutrality. Therefore, batteries are considered to be the best alternatives to current fossil fuels and an icon of the emerging energy industry. Voltaic cells are one of the power sources more frequently employed than photovoltaic cells in vehicles, consumer electronics, energy storage systems, and medical equipment. The most adaptable voltaic cells are lithium-ion batteries, which have the potential to meet the eagerly anticipated demands of the power sector. Working to increase their power generating and storage capability is therefore a challenging area of scientific focus. Apart from typical Li-ion batteries, Li-Air (Li-O2) batteries are expected to produce high theoretical power densities (3505 W h kg-1), which are ten times greater than that of Li-ion batteries (387 W h kg-1). On the other hand, there are many challenges to reaching their maximum power capacity. Due to the oxygen reduction reaction (ORR) and oxygen evolution reaction (OES), the cathode usually faces many problems. Designing robust structured catalytic electrode materials and optimizing the electrolytes to improve their ability is highly challenging. Graphene is a 2D material with a stable hexagonal carbon network with high surface area, electrical, thermal conductivity, and flexibility with excellent chemical stability that could be a robust electrode material for Li-O2 batteries. In this review, we covered graphene-based Li-O2 batteries along with their existing problems and updated advantages, with conclusions and future perspectives.

Fabrication and Characterization of Flexible Cotton Fabric/Carbon Nanotubes/MnO2 Nanocomposite-Based Electrodes for Energy Storage Application.

Flexible cotton fabric based electrodes were fabricated using multi-walled carbon nanotubes (MWCNTs) and manganese dioxide (MnO2) nanocomposite which was prepared using wet chemical synthesis. Characterization of CNT/MnO2 nanocomposite was done by Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photon spectroscopy (XPS), Raman spectroscopy and BET analysis. Their electrochemical properties were investigated using three electrode systems. The high specific capacitance of 634.35 F/g was obtained for the nanocomposite coated cotton fabric prepared via dipping method. The high capacitance was attributed to its high specific surface area 678.9 m2/g. The electrode exhibited high cyclic performance showing retention of 84% of its initial capacity in 0.5 M sodium sulphate (Na2SO4) solution. The demonstrated high specific capacitance of CNT/MnO2 nanocomposite makes it a promising electrode material for energy storage applications due to its low cost and flexibility.

Proximalization of the Vascularized Toe Joint in Finger Proximal Interphalangeal Joint Reconstruction: A Technique to Derive Optimal Flexion From a Joint With Expected Limited Motion.

When used to reconstruct a finger proximal interphalangeal joint, a free toe interphalangeal joint, without modification, cannot meet the motion demands of the finger to allow palm touchdown. This limitation is the direct result of the toe interphalangeal joint having an intrinsic arc of motion that delivers less flexion than that of a normal functioning finger proximal interphalangeal joint. By modifying the inset of the transferred joint to an extra-anatomical more proximal position, this limitation can be overcome. With a mathematical justification highlighted by a clinical illustration, we demonstrate the feasibility and utility of this "proximalization" technique.

Facial transplantation: the first 9 years.

Since the first facial transplantation in 2005, 28 have been done worldwide with encouraging immunological, functional, psychological, and aesthetic outcomes. Unlike solid organ transplantation, which is potentially life-saving, facial transplantation is life-changing. This difference has generated ethical concerns about the exposure of otherwise young and healthy individuals to the sequelae of lifelong, high-dose, multidrug immunosuppression. Nevertheless, advances in immunomodulatory and immunosuppressive protocols, microsurgical techniques, and computer-aided surgical planning have enabled broader clinical application of this procedure to patients. Although episodes of acute skin rejection continue to pose a serious threat to face transplant recipients, all cases have been controlled with conventional immunosuppressive regimens, and no cases of chronic rejection have been reported.

Found in space: computer-assisted orthognathic alignment of a total face allograft in six degrees of freedom.

PURPOSE: Full facial osteomyocutaneous transplantation requires correct 3-dimensional (3D) alignment of donor osseous structures to a new cranial base with minimal reference points and 6 degrees of potential movement. We investigated whether computer-assisted design and manufacturing (CAD/CAM) could enable accurate placement of the facial skeleton. MATERIALS AND METHODS: A prospective single-cohort study of Le Fort III-based maxillary-mandibular segment allotransplantation was performed in 5 cadaver pairs and 1 clinical pair. The osteotomies were modeled using computed tomography (CT) data and 3D modeling software and then translated to the donor-recipient pairs using surgical navigation and osteotomy cutting guides. The predicted values were calculated about all rotational axes (pitch, yaw, and roll) and along all translational axes (vertical, horizontal, and anteroposterior) and used as the independent variable. The primary outcome variable of the actual postoperative CT values was compared for fidelity to the prediction using the intraclass correlation coefficient (ICC). The similarity to the donor versus recipient values was calculated as a secondary independent variable, and both predicted and actual measurements were compared with it as a percentage. RESULTS: The postoperative fidelity to the plan was adequate to excellent (ICC 0.520 to 0.975) with the exception of lateral translation (2.94 ± 1.31 mm predicted left vs 3.92 ± 2.17 mm right actual displacement; ICC 0.243). The predicted and actual values were not consistently skewed toward the donor or recipient values. CONCLUSIONS: We have demonstrated a novel application of CAD/CAM that enables orthognathic alignment of a maxillary-mandibular segment to a new cranial base. Quantification of the alignment in all 6 degrees of freedom delivers precise control compared with the planned changes and allows postoperative quality control.

Chest wall, thymus, and heart vascularized composite allograft proof of concept cadaveric model for heart transplantation.

The use of vascularized composite allografts allows for the reconstruction of complex scenarios that previously have required multistaged operations. Heart transplantation often follows a series of previous operations leading to chest wall deformities and significant mediastinal adhesions that can limit the use of larger hearts, making it difficult to find a suitable donor. Further, research has shown that the use of vascularized bone marrow and vascularized thymus in transplantation potentially prolongs graft survival with decreased immunosuppression requirements. The authors propose using a vascularized composite allograft of the chest wall consisting of sternum and thymus in conjunction with the heart for cardiac transplantation to allow for more flexibility from the donor pool, maintain chest wall integrity and physiology, and potentially immunoregulate the concomitant solid organ transplant.

Revisiting the anatomic relationship of the marginal mandibular nerve and the posterior facial vein: a cadaveric study.

In preparation for the donor and recipient facial vascularized composite allotransplant (VCA), the marginal mandibular nerve branch should be identified and co-apted to the recipient's nerve to allow for re-innervation. We describe a method to identify the marginal mandibular branch of the facial nerve in facial VCA donors and recipients. Through cadaver dissections, the posterior facial vein was traced posteriorly to identify the marginal mandibular branch of the facial nerve. In cases where we were unable to use this relationship, we found the posterior facial venous system to be diminutive. This technique is useful for finding the marginal mandibular branch when dissecting anterograde to the parotid gland.

Comparison of free fibular flaps with reamer-irrigator-aspirator bone grafts for the reconstruction of critical-sized mandibular defects.

OBJECTIVE: Vascularized bone flaps are currently indicated for reconstructing mandibular defects 6 cm or larger. This technique can result in donor-site morbidity and requires microsurgery. To explore alternative methods of mandibular reconstruction, we sought to compare bone graft obtained with the reamer-irrigator-aspirator (RIA) device with the free fibula (FF) flap for the reconstruction of a critical-sized mandibular defect. METHODS: Sixteen 3-month-old Yorkshire pigs underwent 6-cm full-thickness resection of the left mandible. For the FF group (n = 8), an osseous FF flap was raised from the left leg and placed into the defect. For the RIA group (n = 8), a RIA Instrument Set was used on the ipsilateral femur to ream the femoral canal and harvest RIA putty. This putty containing medullary bone marrow contents and cortical bone was packed into the defect. At the study end point, volumetric, biomechanical, and histologic analyses were performed. RESULTS: Operative times were significantly shorter in the RIA group (RIA,126 [30] min; FF, 346 [50] min; P < 0.05). Biomechanical testing of reconstructed sites showed no significant difference in maximum fracture loads between both groups (RIA, 468 [97] N; FF, 689 [262] N; P = 0.11). Mean (SD) volume ratio of bone growth at the reconstructed sites was comparable between both groups (RIA, 71% [4.5%]; FF, 72% [3.3%]; P = 0.60). Equal bone quality was confirmed histologically. CONCLUSIONS: The RIA technique significantly reduces operative time and provides bone of equal strength and histologic quality to FF flap reconstruction in a large animal model. The RIA method may represent an efficient technique for the reconstruction of craniomaxillofacial defects.

Reconstruction of porcine critical-sized mandibular defects with free fibular flaps: the development of a craniomaxillofacial surgery model.

Vascularized bone flaps are the well-known standards of care for reconstruction of segmental mandibular defects ≥ 6 cm. We developed a large animal critical-sized mandibular defect model in which osseous free fibula flaps were used for reconstruction.In this study a total of eight 3-month-old Yorkshire pigs underwent 6 cm full-thickness resection of the left hemimandible. An osseous free fibula flap from the left leg was harvested and contoured to the mandibular defect. Bone placement and plate position was confirmed with fluoroscopy. Animals were followed with serial radiographs and clinical evaluations.Free fibulas were transferred successfully in all eight animals. The average operative time was 346 minutes, and the average flap ischemia time was 86 minutes. The average volume ratio of reconstructed hemimandibles to nonoperated control hemimandibles was 0.72 ± 0.33. The average maximum fracture load was 689 ± 262 N, and the average ratio of biomechanical fracture load for these samples compared with contralateral control hemimandibles was 0.88 ± 0.25.It is concluded that the porcine osseous free fibula flaps can be reliably harvested and viably transferred to critical-sized posterior mandibular defects with acceptable long-term results. The described microsurgical large animal model is acceptable for use in craniomaxillofacial experimentation.

Need of community-based palliative care in rural India and factors that influence its sustainability: a comprehensive exploration using qualitative methodology in rural Puducherry, India.

Background: The existing palliative care services in India are concentrated in urban areas, attached to tertiary care hospitals. This poses issues relating to access and equity for people in rural locations and with low socioeconomic status. A Community-Based Palliative Care (CBPC) service named Sanjeevan has been initiated in Puducherry, a union territory of India to provide physical, social, psychological, and emotional support to incurably ill people, including older adults living in rural areas. Objectives: To understand the social mechanisms that underpin the implementation of CBPC in rural parts of India and the challenges to its sustainability. Design: Qualitative research using focus group discussions (FGDs) and key informant interviews (KIIs). Methods: Community-based participatory research (CBPR) approach was used in this study, and descriptive analysis was done. Through CBPR it was possible to document and interpret local knowledge on the community concerns and assets along with the experiences of the community members. Purposive sampling was used to identify vocal participants involved in patient care and areas of the Sanjeevan program such as financial management, administration, and community mobilization. Seven KIIs and four FGDs were conducted, with 7-8 participants in each. Results: The analysis indicated the need for a CBPC and the factors enabling its establishment. The findings revealed capacity building, resources for palliative care services, and the existing social structure of the community being the main challenges that need to be overcome for better penetration of CBPC services into society. Demand generation through sensitization and administration of services based on the need and regular follow-up remains the key strategies for the sustainability of the program. Conclusion: The CBPC program like 'Sanjeevan' adopted in the rural area of Puducherry can be cited as an example and can be replicated in other rural settings with similar sociocultural characteristics to support people living with end-stage diseases.

Two modes of fusion pore opening revealed by cell-attached recordings at a synapse.

Fusion of a vesicle with the cell membrane opens a pore that releases transmitter to the extracellular space. The pore can either dilate fully so that the vesicle collapses completely, or close rapidly to generate 'kiss-and-run' fusion. The size of the pore determines the release rate. At synapses, the size of the fusion pore is unclear, 'kiss-and-run' remains controversial, and the ability of 'kiss-and-run' fusion to generate rapid synaptic currents is questionable. Here, by recording fusion pore kinetics during single vesicle fusion, we found both full collapse and 'kiss-and-run' fusion at calyx-type synapses. For full collapse, the initial fusion pore conductance (G(p)) was usually >375 pS and increased rapidly at > or =299 pS ms(-1). 'Kiss-and-run' fusion was seen as a brief capacitance flicker (<2 s) with G(p) >288 pS for most flickers, but within 15-288 pS for the remaining flickers. Large G(p) (>288 pS) might discharge transmitter rapidly and thereby cause rapid synaptic currents, whereas small G(p) might generate slow and small synaptic currents. These results show that 'kiss-and-run' fusion occurs at synapses and that it can generate rapid postsynaptic currents, and suggest that various fusion pore sizes help to control the kinetics and amplitude of synaptic currents.

Physiochemical Analysis of Drinking Water and Treatment with a Homemade Filter: A Case Study of Illu Abba Bor Zone, Ethiopia.

The drinking water quality was evaluated in order to provide a continuous supply of clean and safe drinking water for the preservation of public health. The study area consists of three villages: Tulube, Seddo, and Serdo, all of which are located near Mettu town, which is about 550 kilometers south-west of Ethiopia's capital, Addis Ababa. The physical and chemical parameters of the collected drinking water samples were assessed, including pH, turbidity, conductivity, total suspended solids (TSS), total dissolved solids (TDS), and the presence of heavy metals. The samples were examined in the laboratory, and the findings were compared to the World Health Organization (WHO) standards. Almost all of the physiochemical indicators were safe and within the permissible limit for drinking water quality. However, lead ion concentrations were found to be above the WHO standards. An adsorbent produced from banana pseudostems was used to remove lead ions from drinking water. The equilibrium parameters were determined using the Langmuir adsorption isotherm. The drinking water was treated for 4 h in a homemade adsorption column composed of filter medium (sand, charcoal, and powder of treated banana pseudostem). The data revealed that lead ions removal was nearly 70%, but still above the WHO standards.

Fresh Frozen Rib Cartilage Grafts in Revision Rhinoplasty: A 9-Year Experience.

BACKGROUND: Revision rhinoplasty is undoubtedly one of the most challenging procedures in facial plastic surgery. The complexity is compounded when there is a paucity of native septal cartilage to perform the required framework reconstruction. Harvest of autologous costal cartilage can result in increased operative times and possible secondary-site complications such as contour irregularity, poor scarring, and even pneumothorax. METHODS: A retrospective review was conducted of the senior author's (R.J.R.) patients from 2011 to 2020 who underwent primary or revision rhinoplasty. Inclusion criteria consisted of patients with fresh frozen off-the-shelf cartilage used in revision rhinoplasty only with a minimum of 6 months' follow-up. Outcomes for evaluation were warping, resorption, displacement, and infection. RESULTS: The authors identified 226 patients who underwent open rhinoplasty with the use of fresh frozen rib cartilage grafts and met inclusion criteria. The mean follow-up period was 12.18 months (range, 6 months to 8 years). The majority of patients had undergone one prior rhinoplasty procedure (54 percent); however, 4 percent of patients had undergone four or more prior procedures on their nose. The overall infection rate was 2.7 percent ( n = 6), with the majority successfully managed with antibiotics alone (2.3 percent). CONCLUSIONS: The results in revision rhinoplasty are significantly enhanced with the creation of a stable nasal framework using off-the-shelf, easily accessible, specifically tailored fresh frozen cadaveric rib grafts. The long-term outcomes and complication rate in this 9-year retrospective study demonstrates the safety of fresh frozen rib graft in comparison to autologous or irradiated rib graft. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Chest wall reconstruction in a pediatric patient with ectopia cordis.

Ectopia cordis is defined as a congenital malposition of the heart outside of the thoracic cavity. It is a rare condition, and complete ectopia cordis can be a fatal condition. Successful surgical reconstruction of this defect has been reported but is uncommon. The general approach to reconstructing the chest wall involves repositioning the heart and providing adequate coverage of the chest wall defect. We describe our experience with a patient who had complete thoracic ectopia cordis treated with staged chest wall reconstruction. The first stage involved temporary closure with synthetic material, and the second stage involved definitive reconstruction with autologous bone and cartilage grafts supported with plates. The patient has been active and without complaints since the second stage and is awaiting tracheal decannulation. There have been a few descriptions of how to approach chest wall reconstruction in patients with ectopia cordis. The 2 stage method described can be considered to repair the chest wall defect in complete thoracic ectopia cordis.

Routine pathological evaluation of neuroma specimens: is there a rationale?

The routine pathological analysis of therapeutically resected traumatic or postoperative neuroma specimens to confirm diagnosis and rule out occult malignancy remains a controversial issue. Some experts advocate histological analysis of all specimens, and others rely on institutional policy. A retrospective chart review of all patients who underwent excision of clinically diagnosed neuroma over a 6-year period at one institution by a single surgeon was initiated. The correlation of preoperative diagnoses with histological analysis and cost of analyzing specimens individually and over the 6-year period was calculated. Of 515 neuromas resected, 100 were sent for pathological review. Every submitted specimen was histologically confirmed to be a traumatic neuroma, and none of the specimens harbored occult malignancy. Ultimately, no treatment plan was altered after final histology was confirmed. The cost to analyze each specimen (Current Procedural Terminology code 88305) was $495, expressed in U.S. dollars. If every specimen was analyzed, a total cost of $254,925 would have be incurred over the 6-year period. Routine pathological analysis of clinically and intraoperatively confirmed neuromas must be questioned in terms of standard of care requirements given its failure to aid in treatment plans as well as its significant cost to health care systems.

Male Rhinoplasty: Update.

Male rhinoplasty is unique in that it requires precise preoperative planning to achieve a successful result. Better communication and clarity are paramount with male rhinoplasty patients because the patients may be less attentive. It is important for the surgeon to screen the patients for any psychosocial disorders. Through a series of cases, male rhinoplasty techniques are highlighted. Masculine features should be preserved, and the nose should not be feminized or oversculpted. Another key component in any rhinoplasty case is proper skin care, especially during the postoperative period. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, V.

Preventing Lateral Canthal Malposition in Modern Blepharoplasty.

Current goals in lower eyelid blepharoplasty include blending the lower eyelid-cheek junction, which is highlighted in the authors' six-step lower lid blepharoplasty technique. One major question in lower lid blepharoplasty is how to prevent lower lid malposition and ectropion, because these are untoward outcomes after an aesthetic procedure. In the authors' technique, they perform a superficial lateral retinacular canthopexy that is effective and safe and also prevents lower lid malposition or ectropion. A retrospective review of 104 patients who underwent six-step lower lid blepharoplasty was performed. In the authors' series, there was no significant difference between preoperative and postoperative intercanthal angles (p < 0.05), and the lateral canthal position did not change significantly from its preoperative position. The authors' six-step blepharoplasty technique addresses signs of midfacial aging, and the lateral canthopexy technique has been shown to have a minimal complication rate and maintains canthal position. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.