Role of microsurgical techniques combined with Ilizarov techniques in limb salvage and functional reconstruction of thermal­crush injuries of the hand: A case report.

The Ilizarov technology was proposed by Former Soviet orthopedic physician Ilizarov. It is a medical method to reconstruct missing tissues. Ilizarov technology combined with soft tissue stretching technology is of great significance in the treatment of common orthopedic problems like bone defects, finger absence, joint contracture and joint stiffness following thermal-crush injuries of the hand. In the present study a 25-year-old male patient sought for limb salvage treatment 1 month after sustaining thermal-crush injuries of the right hand and forearm. The patient had been treated by another hospital with multiple procedures of debridement, and recommended for forearm amputation. The patient was diagnosed with: i) Postoperative infection of thermal-crush injuries of the right hand and right forearm; ii) comminuted open fractures of the proximal and distal phalanges of the right thumb; iii) osteomyelitis; iv) palm skin defects with exposed tendons; and v) skin defects of the opisthenar and the forearm. After a series of treatments including debridement, removal of necrotic tissue, tissue transplantation, skin pedicle, bone lengthening, external shaping, tissue release, joint fusion, traction and rehabilitation exercises, the patient recovered some hand function. Overall, thermal-crush injuries of the hand are severe, complicated combined injuries composed of both heat burn and compression injury and their treatment is challenging. Overall, microsurgery combined with Ilizarov technology can effectively reconstruct the function of complex thermal-crush injuries of the hand.

Rational design of bimetallic MBene for efficient electrocatalytic nitrogen reduction.

Electrocatalytic nitrogen reduction reaction (NRR) is one of the most promising approaches to achieving green and efficient NH3 production. However, the designs of efficient NRR catalysts with high activity and selectivity still are severely hampered by inherent linear scaling relations among the adsorption energies of NRR intermediates. Herein, the properties of ten M3B4 type MBenes have been initially investigated for efficient N2 activation and reduction to NH3via first-principles calculations. We highlight that Cr3B4 MBene possesses remarkable NRR activity with a record-low limiting potential (-0.13 V). Then, this work proposes descriptor-based design principles that can effectively evaluate the catalytic activity of MBenes, which have been further employed to design bimetallic M2M'B4 MBenes. As a result, 5 promising candidates including Ti2YB4, V2YB4, V2MoB4, Nb2YB4, and Nb2CrB4 with excellent NRR performance have been extracted from 20 bimetallic MBenes. Further analysis illuminates that constructing bimetallic MBenes can selectively tune the adsorption strength of NHNH2** and NH2NH2**, and break the linear scaling relations between their adsorption energies, rendering them ideal for NRR. This work not only pioneers the application of MBenes as efficient NRR catalysts but also proposes rational design principles for boosting their catalytic performance.

Replantation of multiple fingertip amputations using super microsurgery: A case report and literature review.

Background: The fingertip amputation is an amputation type of the finger beyond the proximal nail fold. There is no vein available for anastomoses on the dorsal side of the finger, and the palmar vein of the finger is small and tightly attached to the skin. Therefore, it is relatively difficult to implement surgical anastomoses, which poses challenges to the clinical treatment of fingertip amputations. Case report: A 29-year-old male was admitted to the hospital due to "the amputation of the fingertips of the right index, middle, and ring fingers caused by a heavy object compression 3 h ago". The admission examination revealed that the right index, middle, and ring fingers were completely severed at the 1/2 plane of the nail bed, with irregular sections, severe contusion, and pollution. The X-ray examination showed comminuted fractures of the distal phalanges of the right index, middle, and ring fingers. Based on these findings, the patient was diagnosed with multiple severed fingertips of the right hand (Tamai Zone 1). The patient underwent debridement, vascular exploration, and replantation of the right index, middle, and ring fingertips under emergency general anesthesia. After surgery, anti-inflammatory, spasmolytic, and anticoagulant treatment and regular dressing changes were conducted. The patient did not receive a blood transfusion, and all three fingers survived. The appearance of these fingers was favorable 3 months after surgery, and the flexion and extension of these fingers were normal. Eventually, the patient achieved excellent Chen's hand function scores. Conclusions: To the best of our knowledge, this may be the first successful case regarding the replantation of three fingertips after amputations in Tamai Zone 1 with favorable outcomes. It can be maintained that super microsurgery can be used for the replantation of multiple fingertip amputations.

Ectopic multiple digit replantation salvage of hand torsion injury following anterolateral thigh perforator flap coverage.

Retrieval of four finger injury at proximal stump amputation with segmental injury along with soft tissue defect and impending compartment syndrome continues to be challenge for the surgeon. Immediate transplant considering temporary ectopic foster as a practical option in special case. We describe temporary ectopic finger implant for crush injury at Metacarpophalangeal (MCP level) with hand torsion along with forearm compartment was fostered to Dorsum of the foot. The torsion fingers was temporary fixed with mini external fixator for stabilization as salvage, ALT free flap was used to cover soft tissue defect of the hand. Replantation of survived figure was performed using the long pedicle to anatomical site without crushing the MCP joint to allow for later tendon transfer for finger. Satisfactory function regained with no foster site (foot) complication like pain or disability. The author validated ectopic foster for amputee as and procedure of choice for salvage of extremity under special circumstances.

Rationally Tailoring Chiral Molecules to Minimize Interfacial Energy Loss Enables Efficient and Stable Perovskite Solar Cells Using Vacuum Flash Technology.

Facing the defects and energy barrier at the interface of perovskite solar cells, we propose a chiral molecule engineering strategy to simultaneously heal interfacial defects and regulate interfacial energy band alignment. S-ibuprofen (S-IBU), R-ibuprofen (R-IBU), and racemic ibuprofen (rac-IBU) are used to post-treat perovskite films. rac-IBU molecules possess the strongest anchoring on the surface of perovskites among all chiral molecules, translating into the best defect passivation effect. The hydrophobic isobutyl group and benzene ring could increase the film moisture resistance ability. Due to reduced interfacial defects and interfacial energy barrier, rac-IBU enables efficient devices with a maximum efficiency exceeding 24% based on vacuum flash technology without antisolvents. The encapsulated rac-IBU-modified device could maintain 90% of its initial performance after 1040 h of continuous maximum power point tracking. This work provides a feasible route to minimize interfacial nonradiative recombination losses by controlling spatial conformation via rational chiral molecule engineering.

Flexible and excellent electromagnetic interference shielding film with porous alternating PVA-derived carbon and graphene layers.

Recently, the design of graphene-based films with elaborately controlled microstructures and optimized electromagnetic interference shielding (EMI) properties can effectively improve EM energy attenuation and conversion. Herein, inspired by the structure of multi-layer steamed bread, an alternating multilayered structure with polyvinyl alcohol (PVA)-derived carbon layers and graphene/electrospun carbon nanofibers layers was designed through alternating vacuum-assisted filtration method. The composite film exhibited favorable impedance matching, abundant loss mechanism, and excellent EMI shielding ability, resulting in absorption dominated shielding characteristic. Thus, the resultant 7-layer alternating composite films with a thickness of 160 µm achieved an EMI shielding effectiveness (EMI SE) of up to 80 dB in the X-band. Specially, finite element analysis was applied to demonstrate the importance of seven-layer film alternations and detailed analysis of electromagnetic shielding mechanisms. Taken together, this effort opens a creative avenue for designing and constructing flexible composite films with excellent EMI shielding performance.

The Limb Salvage Approach for the Surgical Management of Necrotizing Soft Tissue Infection.

Necrotizing soft tissue infection (NSTI) is a complex infection known for its rapid progression of necrosis within the subcutaneous tissue and fascia. Time is of essence for the management of NSTI. In this report, we present a case of NSTI after infection of poorly managed diabetic foot ulcer in the ankle. The limb salvage approach involves sequential staged procedures. Multiple surgical debridements and "washout" were performed for source control. At the same time, the patient also received a systemic antibiotic regimen. In the second stage, a perforator free flap taken from the anterolateral thigh was used to repair the extensive soft tissue defect and reconstruct a functional foot to achieve maximal limb salvage. The kickstand technique of external fixation was used to reduce soft tissue compression and enhance the surgical offloading of the skin flap. At the 2-year follow-up, the skin integrity of the flap was well-preserved, and the patient returned to his premorbid quality of life.

Grain boundary defects passivation by bridging diammonium toward stable and efficient perovskite solar cells.

The grain boundary defects of polycrystalline perovskite could induce severe carrier recombination loss to restrict the photovoltaic and stability advancement of perovskite-based solar cells (PSCs). Inserting fixed molar ratio organic cations spacers into halide perovskite slabs to reduce the dimension of the crystal structure is still limited in finding a compromise of efficiency and stability for the widened bandgap and increasing barriers for carrier transport. Here, we select a direct additive bridging engineering to introduce a rationally designed organic amine salt 1,4-Benzene diammonium iodide (BDAI2) with ammonium group on both terminals of the benzene ring to passivate the grain boundary and interface defects of perovskite. Bridging diammonium could ameliorate the interface contact and achieve electrostatic interactions with negatively charged traps (such as uncoordinated I-, PbI3-, and methylammonium vacancies) to inhibit cation migration, reduce halogen ion vacancy, and then suppress trap-induced recombination in perovskite. As a result, the bridging diammonium could improve the power conversion efficiency (PCE) from 19.86% to 21.91%. This study highlights the importance of rational bridging diammonium for perovskite surface modification and passivation to boost photovoltaic performance and stability.

Enhanced Catalytic Ozonation by Mn-Ce Oxide-Loaded Al2O3 Catalyst for Ciprofloxacin Degradation.

Catalytic ozonation is an effective and promising advanced oxidation technology for organic pollutant removal. Herein, CexMn1-xO2 metal oxides loaded on Al2O3 catalysts (Mn-Ce/Al2O3) were synthesized for catalytic ozonation of the wastewater containing ciprofloxacin. The morphology, crystal structure, and specific surface area of the prepared catalyst were characterized. The characteristics of the Mn-Ce/Al2O3 catalyst revealed that the loaded MnO2 could interfere with the formed CeO2 crystals and then produced complex CexMn1-xO2 oxides. Compared with an ozone-alone system (47.4%), the ciprofloxacin degradation efficiency in the Mn-Ce/Al2O3 catalytic ozonation system elevated to 85.1% within 60 min. The ciprofloxacin degradation kinetic rate over the Mn-Ce/Al2O3 catalyst is 3.0 times that of the ozone-alone system. The synergetic corporation of redox pairs between Mn(III)/Mn(IV) and Ce(III)/Ce(IV) in the Mn-Ce/Al2O3 catalyst could accelerate ozone decomposition to generate active oxygen species and further significantly improve the mineralization efficiency of ciprofloxacin. The work demonstrates the great potential of developing dual-site ozone catalysts for advanced treatment of wastewater.

Electromagnetic Response of Multistage-Helical Nano-Micro Conducting Polymer Structures and their Enhanced Attenuation Mechanism of Multiscale-Chiral Synergistic Effect.

Nowadays, the rapidly development of advanced antidetection technology raises stringent requirements for microwave absorption materials (MAMs) to focus more attention on wider bandwidth, thinner thickness, and lower density. Adding magnetic medium to realize broadband absorption may usually result in the decline of service performance and accelerating corrosion of MAMs. Chiral MAMs can produce extra magnetic loss without adding magnetic medium due to the unique electromagnetic cross polarization effect. However, more efforts should be taken to furtherly promote efficient bandwidth of chiral MAMs and reveal attenuation mode and modulation method of chiral structure. Herein, a novel superhelical nano-microstructure based on chiral polyaniline and helical polypyrrole is successfully achieved via in situ polymerization strategy. The enhanced multiscale-chiral synergistic effect contributes to broaden effective absorption bandwidth, covering 8.6 GHz at the thickness of 3.6 mm, and the minimum reflection loss can reach -51.3 dB simultaneously. Besides, to further explain response modes and loss mechanism of superhelical nano-microstructures, the electromagnetic simulation and test analysis are applied together to reveal their synergistic enhancement attenuation mechanism. Taken together, this strategy gives a new thought of how to design, prepare, and optimize the hierarchical structure materials to achieving broadband and high-performance microwave absorption.

Bionic structures for optimizing the design of stealth materials.

Traditional microwave absorbing materials (MAMs) have exposed more and more problems in multi-spectrum detection and a harsh service environment, which hinder their further application. Bionic materials and structures have attracted more and more attention from researchers in the field of stealth materials due to their excellent properties, such as high strength and high conductivity, along with easy access to scale adjustability and structural design. By introducing the concept of bionics into their structural design and material design, we can obtain highly efficient stealth materials with multiple properties. In addition, the concept of multispectral stealth is furthered by comparing the difference in the principle and methods of achievement between radar stealth and infrared stealth. This paper fundamentally summarizes the research status of bionic structure design ideas in stealth materials, analyzing the structure-activity relationship between the structural size effect and electromagnetic characteristics from low order to high order. Then, the design ideas and universal strategies of typical bionic structures are summarised and an idea for the integrated design of radar absorption compatible with infrared stealth is put forward. This will provide profound insights for the application of biomimetic stealth materials and the future development of intelligent-response and dynamically adjustable materials.

Zwitterionic ionic liquid synergistically induces interfacial dipole formation and traps state passivation for high-performance perovskite solar cells.

Defects at the interface and grain boundaries of perovskite solar cells (PSCs) will result in severe non-radiative recombination and open-circuit voltage (Voc) loss. Herein, we reported a zwitterionic ionic liquid imidazolium tetrafluoroborate (IMBF4) to passivate the defects at tin dioxide (SnO2)/perovskite interface. The results showed that the electron-rich nitrogen atom contained IM+ could diffuse into the buried perovskite to exhibit a strong chemical passivation effect on the organic vacancy defect by interacting with uncoordinated Pb2+. The F- in BF4- has a strong coordination effect with Pb2+in perovskite and Sn2+ in SnO2 synchronously to fill the anion vacancy defect. Also, the BF4- anions could help to form an interface dipole layer to increase the charge transfer rate and reduce the work function. The IMBF4 modified device could achieve an efficiency enhancement from 20.18% to 23.05% by vacuum flash-assisted solution-processed, with the increased Voc from 1.09 V to 1.15 V. The unencapsulated IMBF4 modified device could maintain 93% of the initial efficiency after ageing for 2000 h under ambient conditions by the ISOS-D-1 stability-testing protocols. This work emphasizes the importance of multifunctional additives in passivating defects and improving interface contact for achieving efficient and stable perovskite solar cells.

Insights into the mechanism underlying remediation of Cr(VI) contaminated aquifer using nanoscale zero-valent iron@reduced graphene oxide.

Currently, there is an urgent need to develop functional nanomaterials for highly effective environmental remediation. However, the long-term effect of remedial materials upon their injection into contaminated aquifer has frequently been overlooked. Here, the remediation of Cr(VI) contaminated aquifer by reduced graphene oxide (rGO) supported nanoscale zero-valent iron (nZVI@rGO) was investigated from a long-term perspective. The performances of nZVI@rGO samples with different rGO loadings in the removal of aqueous Cr(VI) were evaluated in batch experiments. The electron transfer properties different nZVI@rGO samples were investigated by measuring their corrosive potentials using the steady-state Tafel polarization curves. The results show that the electron transfer efficiency between Cr(VI) and nZVI@rGO is enhanced owing to the large reactive conjugated structure of rGO. Besides, the surface passivation of nZVI is effectively retarded due to the uniform accommodation of Cr(III) precipitates on rGO. The structure and composition of nZVI@rGO before and after Cr(VI) removal were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization results revealed that most Cr(VI) ions (∼90%) will be reduced to Cr(III) precipitates on nZVI@rGO as the passivation product. Accordingly, Cr(VI) ions tend to react more readily at less blocked regions on the surface of rGO, and a layer-by-layer passivation model on nZVI@rGO surface is proposed. Our results provide new insights into the mechanism underlying the long-term remediation of Cr(VI) contaminated aquifer using nZVI@rGO, which helps design new materials and approaches for practical in-situ remediation engineering.

Effects of different low temperature pretreatments on properties of corn stover biochar for precursors of sulfonated solid acid catalysts.

In this study, the effects of different pretreatment methods including phosphoric acid (PA), freeze drying (FD) and phosphoric acid-freeze drying combined (PA-FD) pretreatment on corn stover characteristics and pyrolysis of corn stover samples was investigated. The results demonstrated that the physiochemical properties of biochars varied significantly. In comparison, PA pretreatment could effectively remove a large portion of inorganics and improve the fuel characteristics. PA-CSB-600 had a greater HHV, lower O/C and H/C ratios, and a lower biochar energy yield (Ye), indicating the possibility for an attractive fuel source. PA-FD pretreatment would significantly affected cell volume and caused mechanical damage to corn stover structure. As a sulfonated solid acid catalyst precursor, the results of cellulose catalytic hydrolysis indicated that the density of -SO3H in FD-CSA was much higher than PA-FD-CSA, but lower surface special area. Specifically, PA-FD-CSB prepared at 600 °C resulted in the maximum increase of cellulose conversion by 34.7-81.3%.

Predicting atomic-level reaction mechanisms for SN2 reactions via machine learning.

Identifying atomic-level reaction mechanisms is an essential step in chemistry. In this study, we develop a joint-voting model based on three parallel machine-learning algorithms to predict atomic-level and dynamical mechanisms trained with 1700 trajectories. Three predictive experiments are carried out with the training trajectories divided into ten, seven, and five classes. The results indicate that, as the number of trajectories in each class increases from the ten- to five-class model, the five-class model converges the fastest and the prediction success rate increases. The number of trajectories in each experiment to get the predictive models converged is 100, 100, and 70, respectively. The prediction accuracy increases from 88.3% for the ten-class experiment, to 91.0% for the seven-class, and to 92.0% for the five-class. Our study demonstrates that machine learning can also be used to predict elementary dynamical processes of structural evolution along time, that is, atomic-level reaction mechanisms.

Functionalizing phenethylammonium by methoxy to achieve low-dimensional interface defects passivation for efficient and stable perovskite solar cells.

Low dimensional interface passivation has been proved to be an efficient method to lessen the nonradiative recombination loss in perovskite solar cells. To overcome the limitation of Phenethylammonium (PEA+) for carrier transport and water molecule intrusion, we developed a modification strategy by functioning the typical PEA+with the 4-methoxy to optimize the interface defects and carrier transport performance, thus maximizing the synchronous improvement of device efficiency and stability. Our results indicate that the 2 mg ml-14-methoxy-phenethylammonium (MeO-PEA+) modified device could achieve a best power conversion efficiency of 19.64% with improved shelf-life stability in ambient conditions. The new passivation molecule of MeO-PEA+could possess the capability of defect passivation, carrier transfer, and moisture blocking, demonstrating that rationally designed organic components for interface passivation could help to achieve efficient and stable PSCs.

Circ_0081001 down-regulates miR-494-3p to enhance BACH1 expression and promotes osteosarcoma progression.

The study was aimed at deciphering the function and mechanism of circ_0081001 in osteosarcoma (OS). In this study, quantitative real-time polymerase chain reaction (qRT-PCR) was utilized for quantifying circ_0081001, miR-494-3p, and BTB domain and CNC homolog 1 (BACH1) mRNA expressions in OS tissues and cells. Cell counting kit-8 (CCK-8) assay, together with 5-Ethynyl-2'-deoxyuridine (EdU) assay, was performed for evaluating cell proliferation; the alterations in apoptosis were analyzed utilizing flow cytometry; Transwell assay was conducted for examining cell migration and invasion; moreover, Western blot was utilized for the quantification of BACH1 protein expression; bioinformatics, dual-luciferase reporter gene, and RNA-binding protein immunoprecipitation assays were executed for validating the binding relationships between circ_0081001 and miR-494-3p, and between miR-494-3p and BACH1. As shown, circ_0081001, whose expression was elevated in OS tissues, had a negative association with miR-494-3p expression and a positive correlation with BACH1 expression. After circ_0081001 was overexpressed, the proliferation, migration, and invasion of OS cells were boosted but the apoptosis was reduced, whereas miR-494-3p exhibited opposite effects. The binding sites between circ_0081001 and miR-494-3p, and between miR-494-3p and the 3'UTR of BACH1 were experimentally verified. In conclusion, circ_0081001/miR-494-3p/BACH1 axis promoted the malignant biological behaviors of OS cells.

Spatial variation of dissolved organic nitrogen in Wuhan surface waters: Correlation with the occurrence of disinfection byproducts during the COVID-19 pandemic.

Intensified sanitization practices during the recent coronavirus disease-2019 (COVID-19) led to the release of chlorine-based disinfectants in surface water, potentially triggering the formation of disinfection byproducts (DBPs) in the presence of dissolved organic nitrogen (DON). Thus, a comprehensive investigation of DON's spatial distribution and its association with DBP occurrence in the surface water is urgently needed. In this study, a total of 51 water samples were collected from two rivers and four lakes in May 2020 in Wuhan to explore the regional variation of nitrogen (N) species, DON's compositional characteristics, and the three classes of DBP occurrence. In lakes, 53.0% to 86.3% of N existed as DON, with its concentration varying between 0.3-4.0 mg N/L. In contrast, NO3--N was the dominant N species in rivers. Spectral analysis revealed that DON in the lakes contained higher humic and fulvic materials with higher A254, A253/A203, SUVA254, and PIII+IV/PI+II+V ratios, while rivers had higher levels of hydrophilic compounds. Trihalomethanes (THMs) were the most prevalent DBPs in the surface waters, followed by N-nitrosamines and haloacetonitriles (HANs). The levels of N-nitrosamines (23.1-97.4 ng/L) increased significantly after the outbreak of the COVID-19 pandemic. Excessive DON in the surface waters was responsible for the formation of N-nitrosamines. This study confirmed that the presence of DON in surface water could result in DBP formation, especially N-nitrosamines, when disinfectants were discharged into surface water during the COVID-19 pandemic.

Growth of NiAl-Layered Double Hydroxide on Graphene toward Excellent Anticorrosive Microwave Absorption Application.

High-performance microwave absorbers with special features are desired to meet the requirements of more complex modern service environments, especially corrosive environments. Therefore, high-efficiency microwave absorbers with corrosion resistance should be developed urgently. Herein, a 3D NiAl-layered double hydroxide/graphene (NiAl-LDH/G) composite synthesized by atomic-layer-deposition-assisted in situ growth is presented as an anticorrosive microwave absorber. The content of NiAl-LDH in the composite is optimized to achieve impedance matching. Furthermore, under the cooperative effects of the interface polarization loss, conduction loss, and 3D porous sandwich-like structure, the optimal NiAl-LDH/G shows excellent microwave absorption performance with a minimum reflection loss of -41.5 dB and a maximum effective absorption bandwidth of 4.4 GHz at a loading of only 7 wt% in epoxy. Remarkably, the encapsulation effect of NiAl-LDH can restrain the galvanic corrosion owing to graphene. The epoxy coating with the NiAl-LDH/G microwave absorber on carbon steel exhibits long-term corrosion resistance, owing to the synergetic effect of the superior impermeability of graphene and the chloridion-capture capacity of the NiAl-LDH. The NiAl-LDH/G composite is a promising anticorrosive microwave absorber, and the findings of this study may motivate the development of functional microwave absorbers that meet the demands of anticorrosive performance of coatings.

Preparation of TiO2 Nanotube Array on the Pure Titanium Surface by Anodization Method and Its Hydrophilicity.

In this work, a highly ordered TiO2 nanotube array on pure titanium (Ti) was prepared by anodization. The effects of the applied voltage and anodization time on the microstructure of the TiO2 nanotube arrays were investigated, and their hydrophilicity was evaluated by the water contact angle measurement. It was found that a highly ordered array of TiO2 nanotubes can be formed on the surface of pure Ti by anodized under the applied voltage of 20 V and the anodization time in the range of 6-12 h, and the nanotube diameter and length can be regulated by anodization time. The as-prepared TiO2 nanotubes were in an amorphous structure. After annealing at 550°C for 3 h, the amorphous TiO2 can be transformed to the anatase TiO2 through crystallization. The anatase TiO2 array exhibited a greatly improved hydrophilicity, depending on the order degree of the array and the diameter of the nanotubes. The sample anodized at 20 V for 12 h and then annealed at 550°C for 3 h exhibited a superhydrophilicity due to its highly ordered anatase TiO2 nanotube array with a tube diameter of 103.5 nm.