Involvement of PD-1+CD4+ T cells in the development of traumatic tracheal stenosis by regulating the IL-17/STAT3 pathway

Studies have highlighted an upregulation of PD-1 expression in CD4+ T cells, which accelerates lung fibrosis by activating the IL-17/STAT3 pathway, leading to IL-17A and TGF-β1 secretion. However, the relation with traumatic tracheal stenosis (TS) remains unexplored. Our analysis found significant increases in PD-1+CD4+ T cells, IL-17A, and TGF-β1 in the TS patients (n = 10). The cellular model used CD4+ T cells co-cultured with bronchial fibroblasts while the animal model used a nylon brush to scrape the damaged tracheal mucosa. Interventions with PD-1 and STAT3 inhibitors both in vivo (n = 5) and in vitro (n = 6) showed decreased expression of TGF-β1 and IL-17A in CD4+ T cells, decreased collagen I synthesis in vivo, and reduced tractal fibrosis in vitro. Furthermore, PD-1's modulation of the STAT3 was evident. This research unveils PD-1+CD4+ T cells' role in TS, thus suggesting a novel immunotherapeutic strategy to counteract tracheal fibrosis.

Self-healing hydrogel based on poly (vinyl alcohol)-poly (lysine)-gum arabic accelerates diabetic wound healing under photothermal sterilization

Diabetic wounds are a significant clinical challenge. Developing effective antibacterial dressings is crucial for preventing wound ulcers caused by bacterial infections. In this study, a self-healing antibacterial hydrogel (polyvinyl alcohol (PVA)-polylysine-gum arabic, PLG hydrogels) with near-infrared photothermal response was prepared by linking PVA and a novel polysaccharide-amino acid compound (PG) through borate bonding combined with freeze-thaw cycling. Subsequently, the hydrogel was modified by incorporating inorganic nanoparticles (modified graphene oxide (GM)). The experimental results showed that the PLGM3 hydrogels (PLG@GM hydrogels, 3.0 wt%) could effectively kill bacteria and promote diabetic wound tissue healing under 808-nm near-infrared laser irradiation. Therefore, this hydrogel system provides a new idea for developing novel dressings for treating diabetic wounds.

An NIR light-driven AgBiS2@ZIF-8 hybrid photocatalyst for rapid bacteria-killing

Bacterial infection is the most common risk factor that causes the failure of implantation surgery. Therefore, the development of biocompatible implants with excellent antibacterial properties is of utmost importance. In this study, NIR light-driven AgBiS2@ZIF-8 hybrid photocatalysts for rapid bacteria-killing were prepared. AgBiS2@ZIF-8 exhibited excellent photocatalytic activity due to the rapid transfer of photoelectrons from AgBiS2 to ZIF-8, resulting in abundant reactive oxygen species (ROS) to kill bacteria. Meanwhile, AgBiS2@ZIF-8 exhibited a noteworthy photothermal effect, which could effectively convert NIR light into heat. Subsequently, the NIR light-driven antibacterial activity of AgBiS2@ZIF-8/Ti against S. aureus and E. coli was studied. The experimental results showed that AgBiS2@ZIF-8 displayed enhanced photodynamic therapy (PDT) and photothermal therapy (PTT) performance. Under irradiation with 808 nm NIR light for 10 min, AgBiS2@ZIF-8/Ti could effectively eliminate 98.55% of S. aureus in vitro, 99.34% of E. coli in vitro and 95% S. aureus in vivo. At the same time, AgBiS2@ZIF-8/Ti had good biocompatibility. Therefore, AgBiS2@ZIF-8/Ti showed potential as an antibacterial material, which provided a strategy to fight polymicrobial infections.

AgBiS2@CQDs/Ti nanocomposite coatings for combating implant-associated infections by photodynamic /photothermal therapy

Biofilm-mediated implant-associated infections are one of the most serious complications of implantation surgery, posing a grave threat to patient well-being. Effectively addressing bacterial infections is crucial for the success of implantation procedures. In this study, we prepared a bismuth sulfide silver@carbon quantum dot composite coating (AgBiS2@CQDs/Ti) on a medical titanium surface by surface engineering design to treat implant-associated infections. The photocatalytic/photothermal activity test results confirmed the excellent photogenerated ROS and photothermal properties of AgBiS2@CQDs/Ti under near-infrared laser irradiation. In vitro antibacterial and in vivo anti-infection experiments showed that the coating combined with photodynamic and photothermal therapies to eradicate bacteria and disrupt mature biofilms under 1064 nm laser irradiation. Consequently, AgBiS2@CQDs/Ti shows promise as an implant coating for treating implant-associated infections post-surgery, thereby enhancing the success rate of implantation procedures. This study also provides a new idea for combating implant-associated infections.

Surgical resection of primary intracardiac sarcomas and outcomes: A review of case reports over 20 years

Objective

A quarter of all cardiac tumors are malignant, and most (~ 95%) are sarcomas. It is the most aggressive malignant cardiac tumor carrying the worst prognosis. Tumor involvement with the vital intracardiac structures makes it difficult for complete surgical resection. We aimed to study the role of complete surgical resection and its importance in long-term outcomes.

Methods

We analyzed published literature from 2002 to 2022 using PubMed. Cases reported adult, intracardiac sarcomas, and received surgical resections were included. We reviewed 132 published case reports, including and analyzed the following variables: demographics, clinical presentations, diagnostic imaging modality, the extent of surgical resection, pathological diagnosis, tumor location, postoperative chemo-radiation therapy, and follow-up (including re-operation, local and distant recurrence).

Results

A total of 135 patients are included from 132 articles. The mean age was 46.69 (18-86) and 76 patients were females. The main complaints were dyspnea (70%) and chest pain (32%). Performed investigations were transthoracic echocardiography (TTE) in 114/135 (84%), computer tomography (CT) scan 89/135 (66%), trans-esophageal echocardiography (TOE) 22%, and cardiac magnetic resonance imaging (MRI) 29%. The most common location was the atrium (left 46%, right 30%). Complete surgical resection was performed in 91 cases (67%), and frozen section was performed in 62 patients (43 positives). Incomplete resections were in 42 cases. Patients who underwent complete surgical resection had mean survival of 14.58 months and median of 10.5 months, compared to incomplete resection patients with 9.12 months and 6.5 months respectively.

Conclusion

Our review shows complete surgical resection results in better short- and long-term outcomes in intracardiac sarcoma patients. Furthermore, combining chemo-radiotherapy has additional benefits towards long-term survival.

Intraocular pressure measurements in paediatric glaucoma: A narrative review on accuracy, tolerability, and ease of use

INTRODUCTION

Numerous tonometers are available to measure intraocular pressure (IOP) in children with glaucoma. This review aims to discuss IOP measurement techniques and principles and compare the accuracy, tolerability and ease of use of available tonometers in measuring IOP in paediatric glaucoma patients.

MATERIALS AND METHODS

A review of observational studies was conducted to discuss the accuracy, tolerability and ease of use of tonometers in measuring IOP in children with glaucoma.

RESULTS

Goldmann applanation tonometry (GAT) and its portable handheld versions remain the gold standard in measuring IOP. Tono-Pen (Reichert Ophthalmic Instruments, Depew, New York, USA) and rebound tonometer (RBT) both correlate well with GAT. Although both tonometers tend to overestimate IOP, Tono-Pen overestimates more than RBT. Overestimation is more remarkable in higher IOP and corneal pathologies (such as but not limited to scarred cornea and denser corneal opacity). RBT was better tolerated than other tonometers in children and was easier to use in children of all ages.

CONCLUSIONS

RBT is the preferred tonometer for measuring IOP in children with glaucoma, as it is less traumatic, time efficient and does not require fluorescein dye or anaesthesia. However, examiners should use a second tonometer to confirm elevated IOP readings from the RBT.

Inhibition of the membrane repair protein annexin-A2 prevents tumor invasion and metastasis

Cancer cells are exposed to major compressive and shearing forces during invasion and metastasis, leading to extensive plasma membrane damage. To survive this mechanical stress, they need to repair membrane injury efficiently. Targeting the membrane repair machinery is thus potentially a new way to prevent invasion and metastasis. We show here that annexin-A2 (ANXA2) is required for membrane repair in invasive breast and pancreatic cancer cells. Mechanistically, we show by fluorescence and electron microscopy that cells fail to reseal shear-stress damaged membrane when ANXA2 is silenced or the protein is inhibited with neutralizing antibody. Silencing of ANXA2 has no effect on proliferation in vitro, and may even accelerate migration in wound healing assays, but reduces tumor cell dissemination in both mice and zebrafish. We expect that inhibiting membrane repair will be particularly effective in aggressive, poor prognosis tumors because they rely on the membrane repair machinery to survive membrane damage during tumor invasion and metastasis. This could be achieved either with anti-ANXA2 antibodies, which have been shown to inhibit metastasis of breast and pancreatic cancer cells, or with small molecule drugs.

Fish and Food-Fatale: Food-borne Trematode Opisthorchis viverrini and Cholangiocarcinoma

Neglected Tropical Diseases (NTDs) are a group of communicable diseases with a long history with human beings. NTDs are the proxy of poverty since they affect those in low-income and extreme-poverty populations, as those populations lack access to proper health care, clean water, sanitary conditions, and hygiene. NTDs create losses for a nation that come from the health and the economic sectors as well since the costs of diagnosis, prevention, and treatment strain the national purse strings. One of the 20 different forms of NTDs on the list is food-borne trematodes, comprises of Fasciola, Paragonimus, Clonorchis, and Opisthorchis. Currently, it is estimated that food-borne trematodes can cause a devastating effect on mortality and morbidity. All of them are zoonotic, as humans become infected by ingestion of a second intermediate host, such as freshwater snails, fish, or water vegetables. Opisthorchis viverrini, one of the food-borne trematodes that can be found mostly in South East Asia regions, especially in the Mekong basin, is regarded as a group 1 carcinogen leading to cholangiocarcinoma (CCA). This study aims to present the updated review of Opisthorchis viverrini and CCA.

Silk fibroin-based coating with pH-dependent controlled release of Cu2+ for removal of implant bacterial infections

The implantation of medical devices is frequently accompanied by the invasion of bacteria, which may lead to implant failure. Therefore, an intelligent and responsive coating seems particularly essential in hindering implant-associated infections. Herein, a self-defensive antimicrobial coating, accompanied by silk fibroin as a valve, was successfully prepared on the titanium (Ti-Cu@SF) for pH-controlled release of Cu2+. The results showed that the layer could set free massive Cu2+ to strive against E. coli and S. aureus for self-defense when exposed to a slightly acidic condition. By contrary, a little Cu2+ was released in the physiological situation, which could avoid damage to the normal cells and showed excellent in vitro pH-dependent antibiosis. Besides, in vivo experiment confirmed that Ti-Cu@SF could work as an antibacterial material to kill S. aureus keenly and display negligible toxicity in vivo. Consequently, the design provided support for endowing the layer with outstanding biocompatibility and addressing the issue of bacterial infection during the implantation of Ti substrates.

The diagnostic role of preoperative blood tests in complicated appendicitis: A feasible approach to surgical decision

Background

An accurate diagnosis and timely surgical intervention have significant importance in noncomplicated appendicitis (NCA) and complicated appendicitis (CA). Therefore, any factor that helps in the prediction of CA also contributes to suitable treatment options.

Aim

This retrospective study aimed to identify any relationship between acute appendicitis (AA) and preoperative blood test levels and whether these parameters can differentiate between NCA and CA patients.

Patients and Methods

A database of 201 appendectomies and 100 control healthy patients was analyzed between 2019 and 2022. Patients were divided into three groups: NCA without peritonitis or phlegmonous appendicitis as group 1; CA with perforated, necrotizing appendicitis with peritonitis as group 2; and the healthy control group (CG) as group 3. White blood cell (WBC), platelet distribution width (PDW), mean platelet volume (MPV), red cell distribution width (RDW), creatine kinase (CK), and bilirubin levels were collected from the patients and compared statistically between the groups.

Results

Age, WBC, and PDW levels were set as predictive in the differential diagnosis of CA as a result of receiver operating characteristic (ROC) analysis. The multivariate analysis demonstrated that age (OR: 1.023; 95% CI: 1.000-1.045; P = 0.04), male sex (OR: 3.718; 95% CI: 1.501-9.213; P = 0.005), WBC levels (OR: 1.000; 95% CI: 1.000-1.000; P = 0.002), and PDW levels (OR: 2.129; 95% CI: 1.301-3.484; P = 0.003) were independently associated with CA.

Conclusion

Age, higher WBC count, and PDW levels are valuable in differentiating the diagnosis of CA from NCA, and this could be a feasible approach for surgical decisions.

Fabrication of graphene oxide/copper synergistic antibacterial coating for medical titanium substrate

Titanium (Ti) was an excellent medical metal material, but the lack of good antibacterial activity confined its further practical application. To solve this dilemma, a coating containing graphene oxide (GO) and copper (Cu) was prepared on the surface of Ti sheet (Ti/APS/GO/Cu). First, physical sterilization could be carried out through the sharp-edged sheet structure of GO. Second, the oxygen-containing functional group on the surface of GO and the released Cu²⁺ would generate reactive oxygen species for chemical sterilization. The synergistic effect of GO and Cu substantially enhanced the in vitro and in vivo antibacterial property of Ti sheet, thereby reducing bacterial-related inflammation. Quantitatively, the antibacterial rate of Ti/APS/GO/Cu against E. coli or S. aureus reached over 99%. Besides, Ti/APS/GO/Cu showed excellent biocompatibility and no toxicity to cell. Such work developed multiple sterilization avenues to design non-antibiotic, safe and efficient antibacterial implant material for the biomedical domain.

Same-day discharge (SDD) vs standard enhanced recovery after surgery (ERAS) protocols for major colorectal surgery: a systematic review

BACKGROUND

Enhanced recovery after surgery (ERAS) programs are well-established, resulting in improved outcomes and shorter length of hospital stay (LOS). Same-day discharge (SDD), or "hyper-ERAS", is a natural progression of ERAS. This systematic review aims to compare the safety and efficacy of SDD against conventional ERAS in colorectal surgery.

METHODS

The protocol was prospectively registered in PROSPERO (394793). A systematic search was performed in major databases to identify relevant articles, and a narrative systematic review was performed. Primary outcomes were readmission rates and length of hospital stay (LOS). Secondary outcomes were operative time and blood loss, postoperative pain, morbidity, nausea or vomiting, and patient satisfaction. Risks of bias was assessed using the ROBINS-I tool.

RESULTS

Thirteen studies were included, with five single-arm and eight comparative studies, of which one was a randomised controlled trial. This comprised a total of 38,854 patients (SDD: 1622; ERAS: 37,232). Of the 1622 patients on the SDD pathway, 1590 patients (98%) were successfully discharged within 24 h of surgery. While most studies had an overall low risk of bias, there was considerable variability in inclusion criteria, types of surgery or anaesthesia, and discharge criteria. SDD resulted in a significantly reduced postoperative LOS, without increasing risk of 30-day readmission. Intraoperative blood loss and postoperative morbidity rates were comparable between both groups. Operative duration was shorter in the SDD group. Patient-reported satisfaction was high in the SDD cohort.

CONCLUSION

SDD protocols appear to be safe and feasible in selected patients undergoing major colorectal operations. Randomised controlled trials are necessary to further substantiate these findings.

Amplification of a terahertz wave via stimulated Raman scattering

Extremely strong terahertz (THz) waves are desperately demanded for investigating nonlinear physics, spectroscopy, and imaging in the THz range. However, traditional crystal-/semiconductor-based THz sources have limitations of reaching extremely high amplitude due to the damage threshold of devices. Here, by introducing Raman amplification to the THz range, we propose a novel, to the best of our knowledge, scheme to amplify THz waves in plasma. A long-pulse CO₂ pump laser transfers its energy to a multicycle, 10-THz seed in a two-step plasma. By one-dimensional simulations, a 0.87-GV/m, 1.2-ps-duration THz seed is amplified to 10 GV/m in a 5.7-mm-long plasma with an amplification efficiency approaching 1%. The method provides a new technology to manipulate the intensity of THz waves.

Pt-Quantum-Dot-Modified Sulfur-Doped NiFe Layered Double Hydroxide for High-Current-Density Alkaline Water Splitting at Industrial Temperature

Suitable electrocatalysts for industrial water splitting can veritably promote practical hydrogen applications. Rational surface design is exceptionally significant for electrocatalysts to bridge the gap between fundamental science and industrial expectation in water splitting. Here, Pt-quantum-dot-modified sulfur-doped NiFe layered double hydroxides (Pt@S-NiFe LDHs) are designed with eximious catalytic activity toward hydrogen evolution reaction (HER) under industrial condition. Benefiting from enhanced binding energy, mass transfer, and hydrogen release, Pt@S-NiFe LDHs exhibit outstanding activity in HER at high current densities. Notably, it obtains an impressively low overpotential of 71 mV and long-term stability of 200 h at 100 mA cm^-2 , exceeding commercial 40% Pt/C and most reported Pt-based electrocatalysts. Its mass activity is 2.7 times higher than that of 40% Pt/C with an overpotential of 100 mV. Furthermore, at industrial temperature (65 °C), the electrolyzer based on Pt@S-NiFe LDH needs just 1.62 V to reach the current density of 100 mA cm^-2 , superior to that of the commercial one of 40% Pt/C//IrO₂ . This work provides rational ideas to develop electrocatalysts with exceptional performance for industrial high-temperature water splitting at high current densities.

Diagnostic Performance of High-Resolution Vessel Wall MR Imaging Combined with TOF-MRA in the Follow-up of Intracranial Vertebrobasilar Dissecting Aneurysms after Reconstructive Endovascular Treatment

BACKGROUND AND PURPOSE

Few studies have reported the utility of high-resolution vessel wall MR imaging in the follow-up of endovascularly treated vertebrobasilar dissecting aneurysms. This study aimed to evaluate the diagnostic performance of high-resolution vessel wall MR imaging combined with TOF-MRA in the follow-up of intracranial vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment.

MATERIALS AND METHODS

Patients with intracranial vertebrobasilar dissecting aneurysms with reconstructive endovascular treatment and followed up with TOF-MRA, high-resolution vessel wall MR imaging, and DSA were included. With DSA as the criterion standard, the diagnostic performance of TOF-MRA, high-resolution vessel wall MR imaging, and high-resolution vessel wall MR imaging combined with TOF-MRA in the evaluation of aneurysm occlusion status and parent artery patency was assessed. Visualization of the stented artery on TOF-MRA and high-resolution vessel wall MR imaging was rated on a 5-point scale.

RESULTS

Twenty-seven patients with 29 aneurysms were included. The sensitivity, specificity, positive predictive value, and negative predictive value of TOF-MRA, high-resolution vessel wall MR imaging, and high-resolution vessel wall MR imaging combined with TOF-MRA for diagnosing aneurysm remnants were 80.0%, 100.0%, 100.0%, and 82.4%; 53.3%, 100.0%, 100.0%, and 66.7%; and 93.3%, 100.0%, 100.0%, and 93.3%, respectively. For the visualization of the stented artery, the mean score of high-resolution vessel wall MR imaging was significantly higher than that of TOF-MRA (4.88 [SD, 0.32] versus 2.53 [SD, 1.25], P < .001). In the evaluation of parent artery patency (normal or pathologic), whereas TOF-MRA had a sensitivity, specificity, positive predictive value, and negative predictive value of 100.0%, 8.0%, 14.8%, and 100.0%, respectively, high-resolution vessel wall MR imaging was completely consistent with the DSA.

CONCLUSIONS

High-resolution vessel wall MR imaging combined with TOF-MRA at 3T showed good diagnostic performance in the follow-up of intracranial vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment.

Quality Improvement at the Laboratory’s Specimen Reception Station

Introduction/Objective

In our 1000-bed acute care tertiary hospital, physicians order laboratory tests via the computerized-provider-order-entry (CPOE) system and print barcode labels (patient demographics/tests ordered) at the computer-on-wheel printer. When tubes with unsuitable barcodes (misaligned, poor quality) are received at the laboratory specimen reception area a fresh barcode is re-printed by our laboratory staff. An incident involving a re- printed barcode label pasted on the wrong blood tube prompted an investigation into the quality of barcodes.

Methods/Case Report

We initiated ‘an opportunity for improvement (OFI) project’ at the laboratory specimen reception station. The OFI team involved Nursing, Information Technology (IT) and Pathology departments aimed to eliminate re-printing of barcode labels by 75% within 6 months. We collated and analyzed reasons for re-printing of barcodes on 3 separate 48-hour periods (27-28 April 2020, 24-25 June 2020, and 13-14 June 2022). A series of interventions and initiatives were implemented.

Results (if a Case Study enter NA)

Re-printed barcodes were from the Emergency Department (56%), Out-patient clinics (7%) and Wards (57%). Root cause analysis(RCA) using the “5 whys” technique categorized re-print causes into staff-related (misaligned barcodes) and printer-related (faint barcodes lines/truncated un-verifiable patient demographics). The team mass-emailed clinicians an educational “Do-You-Know” guide on proper pasting of barcodes on blood tubes and instructions on how to obtain help for printer rectification. These guide documents were placed in the hospital-wide document-sharing portal - Docupedia. Immediate close follow-up with sites that had poor barcodes was done in real-time. Barcode reprints decreased 83% within 2 months - from 174 (27-28 Apr 2020) to 30 (24-25 Jun 2020). A recent audit showed sustained elimination of barcode re-printing: 25 cases (13-14 Jun 2022).

Conclusion

The OFI project has successfully raised the quality of CPOE labels on specimen tubes contributing to process efficiency and safer patient care. Close communication with all care sites and their representatives on the OFI team are critical success factors.

Construction of a Well-Defined S-Scheme Heterojunction Based on Bi-ZnFe2O4/S-g-C3N4 Nanocomposite Photocatalyst to Support Photocatalytic Pollutant Degradation Driven by Sunlight

Currently, organic dyes and other environmental contaminants are focal areas of research, with considerable interest in the production of stable, high-efficiency, and eco-friendly photocatalysts to eliminate these contaminants. In the present work, bismuth-doped zinc ferrite (Bi-ZnFe2O4) nanoparticles (NPs) and bismuth-doped zinc ferrites supported on sulfur-doped graphitic carbon nitride (Bi-ZnFe2O4/S-g-C3N4) (BZFG) photocatalysts were synthesized via a hydrothermal process. SEM, XRD, and FTIR techniques were used to examine the morphological, structural, and bonding characteristics of the synthesized photocatalysts. The photocatalytic competence of the functional BZFG nanocomposites (NCs) was studied against MB under sunlight. The influence of Bi (0.5, 1, 3, 5, 7, 9, and 11 wt.%) doping on the photocatalytic performance of ZnFe2O4 was verified, and the 9%Bi-ZnFe2O4 nanoparticles exhibited the maximum MB degradation. Then, 9%Bi-ZnFe2O4 NPs were homogenized with varying amounts of S-g-C3N4 (10, 30, 50, 60, and 70 wt.%) to further enhance the photocatalytic performance of BZFG NCs. The fabricated Bi-ZnFe2O4/30%S-g-C3N4 (BZFG-30) composite outperformed ZnFe2O4, S-g-C3N4 and other BZFG NCs in terms of photocatalytic performance. The enriched photocatalytic performance of the BZFG NCs might be ascribed to a more efficient transfer and separation of photo-induced charges due to synergic effects at the Bi-ZnFe2O4/S-g-C3N4 interconnection. The proposed modification of ZnFe2O4 using Bi and S-g-C3N4 is effective, inexpensive, and environmentally safe.

Fabrication of a TiO2@Cu Core-Shell Nanorod Array as Coating for Titanium Substrate with Mechanical and Chemical Dual Antibacterial Property

Titanium (Ti) is an excellent medical metal material, but the absence of good antibacterial property restricts its widespread application. To overcome this, we thus conducted a series of modifications for Ti. First, a titanium dioxide (TiO₂) nanorod array was generated on the Ti surface by hydrothermal treatment (TiO₂/Ti). With the polymer-mediated self-assembly method, a continuous copper (Cu) shell structure on the surface of the nanorod was then generated to form a TiO₂@Cu core-shell nanorod array as coating for Ti (TiO₂@Cu/Ti). Using pure Ti as the control group, the antibacterial properties of TiO₂/Ti and TiO₂@Cu/Ti were appraised. The results manifested that the mechanical and chemical dual function of the released Cu²⁺ and TiO₂ nanorod array could effectively kill bacteria on the surface of Ti. Besides, the obtained coating exhibited no cytotoxicity and favorable biocompatibility. In this work, we found an antibacterial strategy based on multiple sterilization pathways, which made Ti have good antibacterial property and further improved its biocompatibility.

Assessment of optimal thresholds for ventricular scar substrate characterization using the high density grid multipolar mapping catheter

Funding Acknowledgements

Type of funding sources: None.

Background

Voltage thresholds for ventricular scar definition are based on historic data collected using catheters with widely spaced bipoles in the absence of contact force. Modern multipolar mapping catheters employ smaller electrodes and interelectrode spacing that theoretically allows for mapping with increased resolution and reduced far-field electrogram (EGM) component. Despite the advancement in technology, historic cut-offs of &lt;0.5mV for dense scar and 0.5-1.5mV for scar borderzone continue to be used in contemporary electrophysiology.

Purpose

We aimed to assess the optimal voltage cut-offs for ventricular scar substrate characterization using the HD Grid multipolar mapping catheter. Voltage cut-offs were assessed against cardiac MRI derived scar. We compared optimal voltage cut-offs using conventional bipolar sampling, the Best Duplicate Algorithm and with the HD wave solution plus best duplicate algorithm on.

Methods

A multicentre study of twenty patients undergoing VT ablation was conducted. Substrate mapping was performed using the high-density HD-grid multipolar mapping catheter. Bipolar voltage maps were co-registered with cardiac MRI obtained prior to the procedure to assess the voltage characteristics of scar defined by cardiac MRI (CMR) (Figure 1). Pre-procedure contrast enhanced CMR data were analysed using ADAS software (Galgo medical). Data points were collected in regions of scar during (1) HD wave mapping with best duplicate algorithm on(Waveon), (2) Mapping with HD wave off and best duplicate on (Waveoff) and (3) with conventional bipolar mapping (Alloff).

Results

The median bipolar voltage for regions of dense CMR scar using (Waveon) HD wave solution and best duplicate algorithm was 0.27mV (IQR 0.14 – 0.46). The median voltage with (Waveoff) HD wave off was 0.29mV (0.15 – 0.45). The median voltage with (Alloff) HD wave off and best duplicate off was 0.32mV (0.19 – 0.5). ROC analysis using AUC suggested the optimal cut-off for endocardial dense scar using (Waveon) HD wave mapping and best duplicate algorithm was 0.30mV (sensitivity: 69.6%, specificity: 60.74%), (Waveoff) cut-off with the best duplicate and without the HD wave mapping was 0.34mV (sensitivity: 69.78%, specificity: 64.46%) and (Alloff) without wave mapping or best duplication was 0.36mV (sensitivity: 84%, specificity: 52%) Figure 2.

Conclusion

Ventricular substrate characterization with newer mapping technology using narrow electrode spacing and smaller electrode size suggests that traditional voltage cut-offs may need revision for delineation of scar characteristics. Additionally, the ability to repeat sample in a region to obtain the best signal (Best Duplicate), and the ability to obviate the effect of wavefront direction using the HD wave solution omnipolar technology, may further increase the fidelity of scar characterization. This has important implications for mapping VT and characterizing channels in order to identify VT circuits.

Integration of structural and functional data in VT ablation -- SENSE2 protocol mapping

Funding Acknowledgements

Type of funding sources: None.

Background

We have previously developed the sense protocol functional substrate mapping technique for VT ablation(1). However, functional substrate characterizaiton can involve protracted mapping time.

Purpose

We incorporated the integration of MRI data using ADAS-3D software into the mapping workflow, to integrate structural mapping information into the functional mapping substrate characterization, in order to improve procedural efficiency.

Methods

CMRs were performed in 20 patients with ischemic related VT and VT therapy in the previous 6 months. These were processed with the ADAS-3D software to characterize the extent of ventricular scars and also ADAS corridors which may correlate with VT channels. Focused substrate maps were then performed in patients, guided by the extent of ADAS scar and corridors, looking at the scar substrate in intrinsic rhythm and then functional channels using single extra pacing from the RV at 20ms above ERP (SENSE2 Protocol). Specifically healthy areas 2cm beyond the scar borderzone based on ADAS were not mapped, in order to reduce substrate mapping time and complete geometries were not created. Following delineation of functional channels pacemapping and entrainment mapping were used to confirm targets for ablation.

The ADAS 3D MRI was integrated into the into the VT substrate map on Ensite-Precision with alignment to the aorta, RV and PA (Figure 1). We compared our data with previous functional mapping data without the integration of MRI.

Results

20 patients (age 70 years; 19 male subjects) underwent ablation. Mean EF 28%. Median procedure time was 161 minutes compared with 246 minutes (in our previous study)(p=&lt;0.001) Mean substrate mapping time was 32 mins vs 63 mins (p=&lt;0.001). Mean ablation time was 22 mins vs 32 mins (p=0.11). 85% (17 of 20) patients were free from symptomatic VT/ anti-tachycardia pacing or implantable cardioverter defibrillator shocks at a median follow-up of 171 days. The mean VT burden was reduced from 22 events per patient in the 6 months’ pre-ablation to 1 event per patient in the median follow up period of 171 days post ablation (p=0.02). Mean shocks per-patient burden decreased from 3.5 to 0.08 in the same time period(p=0.03).

Conclusion

The SENSE2 protocol involves the integration of structural and functional data into the VT workflow for substrate characterization. It enables focused substrate maps to be performed without the need for complete geometry to be created in large ventricles. Outcomes compare favourably with our previous data but with significantly shorter procedure times. This streamlined workflow has the potential to improve care in VT ablation by shortening procedure times with similar outcomes which may reduce risks for the patient.

Figure 1: Comparison of Voltage Map with MRI scar & corridors using ADAS

Implanting a Copper Ion into a TiO2 Nanorod Array for the Investigation on the Synergistic Antibacterial Mechanism between Mechanical Cracking and Chemical Damage

Titanium (Ti) and its alloys are extensively applied in dental and orthopedic implants due to their characteristics of good mechanical property and corrosion resistance. However, Ti and its alloys suffer from the absence of certain biological activity and antibacterial ability. Herein, we synthesized a titanium dioxide (TiO₂) nanorod array on the surface of a Ti plate, and the obtained TiO₂ nanorod array was further modified by Cu ions through ion implantation technology in an attempt to endow medical Ti with an antibacterial ability and maintain a normal biological function synchronously. The antibacterial ability of the TiO₂ nanorod array with the incorporation of Cu ions was vastly improved compared with those of the unmodified TiO₂ nanorod array and pure Ti. In particular, owing to the synergy between the chemical damage of the released Cu²⁺ to the cell and the mechanical cracking of the TiO₂ nanorod array, the antibacterial rate of the TiO₂ nanorod array modified by Cu ions against Escherichia coli or Staphylococcus aureus could reach 99%. In addition, no cytotoxicity was detected in such prepared coating during the CCK-8 assay. Moreover, the corrosion resistance of the sample was significantly better than that of pure Ti. Overall, we demonstrated that the application of ion implantation technology could open up a promising pathway to design and develop further antibacterial material for the biomedical domain.

Fabrication of Laponite-Reinforced Dextran-Based Hydrogels for NIR-Responsive Controlled Drug Release

Natural polymer gels with sensitivity to near-infrared (NIR) light have attracted the attention of scientists working on intelligent drug delivery systems. Compared to ultraviolet or visible light, NIR light has the advantages of strong trigger levels, deep penetration through affected tissues, and fewer side effects. Herein, we present a topical photothermal hydrogel for NIR-controlled drug delivery. The proposed DexIEM-GM-Laponite hydrogel was prepared through free radical polymerization of vinyl-functionalized dextran (DexIEM), vinyl-modified graphene oxide (GM), and Laponite; thereafter, the hydrogel was loaded with ciprofloxacin (CIP, an antibacterial drug) as a model drug. With the Laponite content increased, the density of crosslinking in the hydrogel increased, and its mechanical properties improved noticeably. Under NIR irradiation, the DexIEM-GM-Laponite hydrogel exhibited a photothermal property, where the surface temperature increased from 26.8 to 55.5 °C. The simulation of subcutaneous drug delivery experiments ex vivo showed that under the specified pork tissue thickness (2, 4, and 6 mm), the CIP release remained NIR-controllable. Additionally, the results of the antibacterial performance tests indicated the excellent antibacterial effect of the hydrogel, and the blood hemolysis ratio of the hydrogel was less than 5%, signifying good blood compatibility. This work will provide an avenue for the application of NIR light-responsive materials in antimicrobial therapy.

Bio-Based Aerogel Based on Bamboo, Waste Paper, and Reduced Graphene Oxide for Oil/Water Separation

In recent years, the discharge of industrial waste oil has increased and offshore oil leakage has occurred frequently, and thus water pollution has become a worldwide problem that attracts much attention. In this regard, a kind of oil-absorbing material with high oil-absorbing property and good mechanical property is urgently needed. Here, we reported a new type of aerogels with three-dimensional layered voids using natural bamboo powder, waste paper (WP), and graphene oxide (GO) as raw materials. The obtained aerogel had high adsorption capacity (87-121 g/g), compressibility, and high elasticity, which can separate oil from water and selectively absorb oil. This study provides not only a new treatment in agricultural waste treatment but also a facile, green, and low-cost approach to synthesize high-performance graphene-based oil absorbers, which might give us an effective solution for oil pollution of water resources worldwide.

A novel Janus sponge fabricated by a green strategy for simultaneous separation of oil/water emulsions and dye contaminants

A novel Janus sponge with the ability to remove complex contaminants from water is reported. Firstly, a superhydrophilic sponge (PA@PEI-sponge) is prepared via synthesizing negatively charged phytic acid@polyethyleneimine (PA@PEI) nanoparticles and assembling them on the surface of polydopamine (PDA) and PEI-modified polyurethane (PU) sponge through electrostatic adsorption. The Janus sponge is generated by modifying one side of the PA@PEI-sponge with PDMS, which exhibits superior separation efficiency and high filtration flux toward both water-in-oil and oil-in-water emulsions due to its multiplex selective wettability and the interconnected and tortuous 3D porous channels. The numerous negatively charged active sites of PA@PEI nanoparticles and PDA layer impart the superhydrophilic PA@PEI-sponge with the removal efficiency of 39.95 ± 0.27% for malachite green (MG) via simple flow-through filtration, which can be improved to 99.92 ± 0.07% by Janus modification. More importantly, the Janus sponge exhibits an excellent treatment capacity for complex mixtures containing emulsified oil and dye, with the separation efficiency above 99.59%. The Janus sponge also demonstrates the effective separation of real industrial wastewater collected from an acrylic dyeing plant. Together with a facile and green preparation strategy, this Janus sponge shows excellent application potential for simultaneous dye removal and oil/water emulsion separation.

Preparation of silane-dispersed graphene crosslinked vinyl carboxymethyl chitosan temperature-responsive hydrogel with antibacterial properties

We synthesized a temperature-sensitive antibacterial hydrogel, defined as NIPAM-CG/GM hydrogel. First, vinyl carboxymethyl chitosan (CG) was synthesized as a crosslinking carrier and silane dispersed graphene (GM) was synthesized as a reinforcer. Then, the N-isopropylacrylamide (NIPAM) monomer was free-radical polymerized with the vinyl groups of CG and GM to form a NIPAM-CG/GM hydrogel without any crosslinking agent. The influences of different hydrogel compositions on the microstructure, compressive properties, swelling, drug loading, and drug release properties of the hydrogels were discussed, and its temperature sensitivity was also demonstrated. The results showed that the lower critical solution temperature (LCST) and mechanical properties of the hydrogel could be adjusted by controlling the amount of CG and GM. Next, its biocompatibility was characterized, and its antibacterial performance was tested against Escherichia coli and Staphylococcus aureus. The antibacterial mechanism was explained by measuring the difference in the ion concentration outside the membrane and changes in the morphology of live/dead bacteria. NIPAM-CG/GM had a high drug loading and nearly complete drug release at a physiological temperature of 37 °C. Its moderate mechanical properties, excellent biocompatibility, and antibacterial effects give NIPAM-CG/GM great potential applications as a wound dressing.

Pigment concentrations in eggshell and their related gene expressions in uterus of Changshun blue eggshell chickens

1. The goal of this study was to investigate the colour diversity of egg shells and expression of related genes in the uterus of chickens that produce eggs of different colours.2. Four colour types of Changshun blue-shell chickens, producing dark or light blue, greenish-brown and brown shelled eggs, were selected. The eggshell pigment concentration and colour values in each group were examined. The relative gene expression of solute carrier organic anion transporter family member 1C1 (SLCO1C1), ferrochelatase (FECH), haem oxygenase 1 (HO-1), ovotransferrin (OF) and biliverdin reductase A (BLVRA) in eggshell gland were measured.3. The Δb, ΔE and protoporphyrin in brown and greenish-brown groups were significantly higher in the blue egg group (P < 0.01), whereas ΔL was significantly lower than that in the blue eggs (P < 0.01). There was no significant difference in biliverdin concentration between the brown and blue groups.4. The Δa values, in descending order, were 8.27 ± 2.76 in the brown, -3.79 ± 2.39 in the greenish-brown and -7.29 ± 2.27 in the blue groups, respectively. The relative expression of HO-1 in the greenish-brown and light blue groups was significantly higher than in the dark blue and brown groups. The relative expression of FECH in the light blue group was significantly lower than that in the dark blue, greenish-brown or brown group (P < 0.01). The relative expression of HO-1 and BLVRA genes in the dark blue group was significantly higher than that in the light blue, greenish-brown and the brown group (P < 0.01).5. The Δa might provide a better index than protoporphyrin and biliverdin contents for eggshell colour breeding. Overall, HO-1 as well as BLVRA were important candidate genes for the selection of dark blue eggs.

Long term prognostic utility of exercise capacity in renal transplant candidates

Background

Pharmacological stress testing is commonly performed for cardiovascular risk stratification in potential renal transplant candidates due to a perceived inability for these patients to exercise. We have previously reported that exercise stress testing is feasible in renal transplant candidates but the prognostic utility of exercise capacity in this patient group is not known.

Purpose

This study prospectively evaluated the effect of exercise capacity on the risk of major adverse cardiovascular events (MACE), defined as a composite of cardiac death, non-fatal myocardial infarction, and stroke, in renal transplant candidates undergoing exercise stress echocardiography (ESE) for pre-transplant cardiovascular assessment.

Methods

We evaluated 898 consecutive patients with chronic kidney disease stage 4/5 who underwent symptom-limited treadmill ESE over 5-year mean follow-up. Exercise capacity was measured by age and sex predicted metabolic equivalents (METs). The primary outcome was achievement of predicted METs with first MACE. Cox proportional hazard multivariable modelling was used to determine MACE predictors with transplantation treated as a time-varying covariate. We also performed secondary analysis using a 7 MET threshold.

Results

There were 106 MACE with an annual cumulative risk of 2.4%. During follow-up, 525 (58%) received transplantation. Achievement of predicted METs (48%) (hazard ratio (HR) 0.49, 95% confidence interval (CI) 0.29–0.82, p=0.007) and transplantation (HR 0.52, 95% CI 0.30–0.91, p=0.02) were independently associated with reduced MACE. Similar results were observed using a 7 MET threshold achieved by 734 (82%) patients. Patients achieving predicted METs had no difference in MACE regardless of subsequent transplantation (HR 0.78, 95% CI 0.32–1.92, p=0.59). Patients who achieved predicted METs and did not receive transplantation had similar outcomes to those that did not achieve predicted METs and received transplantation (HR 0.97, 95% CI 0.42–2.25, p=0.95).

Conclusions

Exercise capacity is associated with reduced long-term MACE in renal transplant candidates undergoing ESE for pre-transplant cardiovascular assessment. Achievement of age and sex predicted METs confers excellent prognosis independent of subsequent transplantation.

Funding Acknowledgement

Type of funding sources: None.

Assessing learner engagement with virtual educational events: Development of the Virtual In-Class Engagement Measure (VIEM)

BACKGROUND

The COVID-19 pandemic has necessitated virtual education, but effects on learner engagement are unknown. We developed a virtual in-class engagement measure (VIEM) to assess learner engagement in online surgical education events.

METHODS

Using the STROBE, an observer collected tool to document student engagement, as a template an ASE committee workgroup developed the VIEM. The VIEM had two parts: observer assessment and learner self-assessment of engagement. Trained observers collected engagement data from two institutions using the VIEM. Surgical attendings, fellows and residents were observed during virtual learning events. Educator attitudes towards online teaching were also assessed via survey.

RESULTS

22 events with 839 learners were observed. VIEM distinguished between sessions with low and high engagement. 20% of learners pretended to participate. Half of instructors were comfortable with virtual teaching, but only 1/3 believed was as effective as in-person. 2/3 of teachers believed video learners were more engaged than audio learners.

CONCLUSIONS

Virtual platforms do not automatically translate into increased engagement. Standard tools such as VIEM may help with assessment of engagement during virtual education.

Fabrication of a Cu Nanoparticles/Poly(ε-caprolactone)/Gelatin Fiber Membrane with Good Antibacterial Activity and Mechanical Property via Green Electrospinning

To improve the antibacterial effect of a poly(ε-caprolactone)/gelatin (PCL/Gt) composite, Cu nanoparticles (Cu NPs) were synthesized as an antibacterial agent, and a Cu NPs/PCL/Gt fiber membrane was thus fabricated via green electrospinning. The results showed that the Cu NPs/PCL/Gt fiber membrane with a uniform and complete structure exhibited high porosity and water absorption, favorable hydrophilicity, good mechanical and thermal properties, and satisfactory antibacterial activity. The easy preparation and good comprehensive property implied the great potential application of the Cu NPs/PCL/Gt fiber membrane in various fields (e.g., wound dressing and antibacterial clothing). In addition, the synthesis in this work would offer a promising approach for the preparation of a metal nanoparticle/polymer fiber material with good antibacterial property.

P–709 Dual stimulation in-vitro-maturation (Duostim IVM) for overcoming oocyte maturation arrest, resulting in embryo transfer and livebirth

Study question

Does luteal phase followed by follicular phase letrozole priming and dual oocyte retrieval for in-vitro maturation (IVM) overcome oocyte maturation arrest (OMA)?

Summary answer

Oocyte maturation, fertilization,embryo cryopreservation and livebirth can be achieved with letrozole priming IVM in rare cases of OMA.

What is known already

OMA is an intractable problem resulting in only immature oocytes being collected and to date no succesful treatment exists. Attempts to mature oocytes collected in stimulated IVF cycles with OMA have so far failed. Cases with OMA can be due to intrinsic oocyte defects, intrafollicular factors or resistance to stimulation.

Study design, size, duration

Six women with OMA in ≥ 2 prior stimulated IVF cycles were treated between March 2019 and December 2020.

Participants/materials, setting, methods

Participants had total of 18 (range 2 - 6) prior IVF cycles yielding only 166 immature oocytes. Letrozole 5mg was given days 15–18 of ovulatory cycle; SC decapeptyl 0.1mg trigger given at follicles 12 mm, 38 hours&lt;OPU. After menstruation, letrozole 5mg days 3–7; SChCG 250ug when follicles=12 mm 38 hours&lt;OPU. After in-vitro-maturation oocytes reaching MII were fertilized. Embryos from luteal collection were frozen and fresh embryo transfer was attempted after follicular phase collection.

Main results and the role of chance

Six women underwent DuoStim IVM, median (quartiles) 3.5 (0 - 9) GV and 0.5 (0 - 2) MI oocytes were collected from luteal phase OC and 0 (0 - 0) GV and 2(0 – 4.5) MI oocytes were collected from follicular phase OC. They had a total of 166 immature oocytes collected in prior IVF cycles. There were no MII oocytes at the time of collection in any cycles.0 (0 – 3.5) oocytes matured from luteal phase OC and 1 (0 – 4) from follicular phase OC. 0 (0 – 1.5) embryos were available from luteal phase and 0 (0 - 2) from follicular phase OC.Two subjects (29 and 33 years old) underwent fresh DET and the 29 year old with 2 previous failed IVF cycles achieved a livebirth (50% per ET and 16.7% per started cycle). None of the women who did not have an embryo for fresh transfer from the follicular phase collection had an embryo from the luteal phase collection. The same 29 year old has 2 luteal phase and 2 more follicular phase embryos vitrified.

Limitations, reasons for caution

OMA is a rare condition with a variety of etiologies. Different etiologies can require different managements.

Wider implications of the findings: It may be possible to overcome OMA with letrozole IVM in rare cases. This case is the first recorded live birth. The value of dual stimulation overcoming OMA remains uncertain.

Trial registration number

This study is approved by the local ethical commitee of Medicana Samsun International Hospital by a Grant number of 02/05.02.2020: registration is not required due to retrospective status

Mechanism Insight into Rapid Photodriven Sterilization Based on Silver Bismuth Sulfide Quantum Dots

Microbial contamination and the prevalence of resistant bacteria is considered a worldwide public health problem. Therefore, recently, great efforts have been made to develop photoresponsive platforms for the simultaneous photodynamic antibacterial (PDA) and photothermal antibacterial (PTA) therapy processes as mediated by specific light. However, owing to the absorption mismatches of the photothermal agents and photodynamic photosensitizers, it has been discovered that many synergistic photoresponsive antibacterial platforms cannot be excited by a single-wavelength light. In this study, silver bismuth sulfide quantum dots (AgBiS₂ QDs) identified from the literature as a near-infrared light (NIR) that triggers bifunctional materials with simultaneous photodynamic and photothermal effects for photoresponsive bacterial killing were used. Specifically, AgBiS₂ QDs were successfully synthesized via a bottom-up approach, using polyethylenimine (PEI) as an assistant molecule. With PEI wrapping, the attachment between the negatively charged membrane surfaces of the bacterial cells and AgBiS₂ QDs was enhanced via the electrostatic interactions. The photodriven antibacterial activity of AgBiS₂ QDs was then investigated against both S. aureus and E. coli. The results revealed a significant reduction in bacterial survival. The killing effect was found to be independent of the AgBiS₂ QDs, and redox potentials controlled the photogenerated electrons that thermodynamically favored the formation of multiple reactive oxygen species (ROS). A possible phototriggered antibacterial mechanism was then proposed in which the AgBiS₂ QDs are anchored first to the bacterial surface and then induce breaking on its outer membrane by high local heat and ROS under single 808 nm NIR laser illumination to finally induce bacterial death.

173 Early Results of a Variable-Angle Volar Locking Plate for Distal Radius Fractures: A Bi-Centre Study

Introduction

This study examines the clinical, functional and radiological outcomes of distal radius fracture fixation with the Aptus® (Medartis, Pennsylvania) locking plate in order to determine its efficacy and to identify notable findings related to treatment variations.

Method

This is a retrospective bi-centre study collecting patient details from a District General Hospital and a Regional Hand Unit. We assessed 61 consecutive patients with distal radius fractures (AO grade A = 19, B = 9, C = 33) fixed using Aptus® plate with a minimum of six months follow-up. Outcome measures included the DASH score, wrist range of movement and grip strength, and complications. Radiographs were reviewed to assess restoration of anatomy and union.

Results

All but two fractures united within six weeks. Mean ranges of movement were only mildly restricted compared to the normal wrist (flexion/extension = 102°; radial/ulna deviation = 53°; pronation/supination = 169°). Mean postoperative grip strength was 23.8kg which was comparable to the contralateral side at 31.5kg. The mean DASH score was 18.2. Seven patients had screws misplaced outside the distal radius although three of these remained asymptomatic.

Conclusions

Variable-angle locking systems benefit from flexibility of implant positioning and may allow enhanced inter-fragmentary reduction for accurate fixation of intra-articular fractures.

P22: CONSERVATIVE MANAGEMENT OF NECK OF FEMUR FRACTURES

Introduction

According to NICE CG124, the gold standard of treatment for neck of femur (NOF) fractures is operative management on the day or day after admission. In practice, this is not always achievable depending on various factors, e.g. patient preference, clinical condition and theatre availability, with a further subset of patients undergoing conservative management.

Method

A retrospective analysis was performed on all NOF fractures managed non-operatively at a single centre from January 2017 to August 2019 by case notes analysis and review of radiographical images. Demographics, fracture type, pre-fracture mobility status, co-morbidities, mortality and Nottingham Hip Fracture Score (NHFS) are reported. Where applicable, our dataset is correlated with the National Hip Fracture Database for comparison.

Result

24 patients were included in the study period, with a mean age of 79.9 years (range 54-99 years) and male:female ratio of 0.85:1. The mean NHFS (n=18) was 5.7 (range 3-8) and at least 62.5% (n=15) were deemed unfit for surgery or arrested pre-operatively. Conservatively managed NOF fractures are associated with a 30-day mortality of 41.7% compared to the centre average of 8.2% and national average of 6.9% for all NOF fractures. Overall mortality within 1 year is 95.5% (n=22).

Conclusion

Our study confirms that the conservative management of NOF fractures is associated with high mortality, however it may be the only treatment option acceptable in patients who are limited by unfavourable clinical conditions. Therefore, the decision for conservative management in NOF fractures requires careful consideration with the need for an established decision-making pathway.

Take-home message

The conservative management of neck of femur fractures is associated with high mortality, therefore requires careful consideration with the need for an established decision-making pathway.

High-Performance Three-Dimensional Aerogel Based on Hydrothermal Pomelo Peel and Reduced Graphene Oxide as an Efficient Adsorbent for Water/Oil Separation

In this study, HPP-RGO aerogels, which were based on a hydrothermal pomelo peel (HPP) and reduced graphene oxide (RGO), were fabricated by using a green and eco-friendly two-step hydrothermal method. The characterization results showed that the HPP-RGO aerogel was endowed with extremely low density, high specific area, robust thermal stability, good mechanical property, stable acid-alkali resistance, superior recyclability, and excellent hydrophobicity and lipophilicity. Remarkably, the typical 40%-HPP-RGO aerogel presented a preferable adsorption capacity (45-80 g·g^-1). Moreover, continuous water/oil separation was achieved via the water ring vacuum pump. The successful preparation of the HPP-RGO aerogel endows the pomelo peel with high value-added properties and improves the comprehensive utilization of agricultural wastes. Furthermore, it would open up bright prospects for the field of oil adsorption and water/oil separation.