Floquet Engineering the Exceptional Points in Parity-Time-Symmetric Magnonics.

Magnons serve as a testing ground for fundamental aspects of Hermitian and non-Hermitian wave mechanics and are of high relevance for information technology. This study presents setups for realizing spatiotemporally driven parity-time- (PT) symmetric magnonics based on coupled magnetic waveguides and magnonic crystals. A charge current in a metal layer with strong spin-orbit coupling sandwiched between two insulating magnetic waveguides leads to gain or loss in the magnon amplitude depending on the directions of the magnetization and the charge currents. When gain in one waveguide is balanced by loss in the other waveguide, a PT-symmetric system hosting non-Hermitian degeneracies [or exceptional points (EPs)] is realized. For ac current, multiple EPs appear for a certain gain-loss strength and mark the boundaries between the preserved PT-symmetry and the broken PT-symmetry phases. The number of islands of broken PT-symmetry phases and their extensions is tunable by the frequency and the strength of the spacer current. At EP and beyond, the induced and amplified magnetization oscillations are strong and self-sustained. In particular, these magnetization auto-oscillations in a broken PT-symmetry phase occur at low current densities and do not require further adjustments such as tilt angle between electric polarization and equilibrium magnetization direction in spin-torque oscillators, pointing to a new design of these oscillators and their utilization in computing and sensorics. It is also shown how the periodic gain-loss mechanism allows for the generation of high-frequency spin waves with low-frequency currents. For spatially periodic gain and loss acting on a magnonic crystal, magnon modes approaching each other at the Brillouin-zone boundaries are highly susceptible to PT symmetry, allowing for a wave-vector-resolved experimental realization at very low currents.

Skyrmion Echo in a System of Interacting Skyrmions.

We consider helical rotation of skyrmions confined in the potentials formed by nanodisks. Based on numerical and analytical calculations we propose the skyrmion echo phenomenon. The physical mechanism of the skyrmion echo formation is also proposed. Because of the distortion of the lattice, impurities, or pinning effect, confined skyrmions experience slightly different local fields, which leads to dephasing of the initial signal. The interaction between skyrmions also can contribute to the dephasing process. However, switching the magnetization direction in the nanodiscs (e.g., by spin transfer torque) also switches the helical rotation of the skyrmions from clockwise to anticlockwise (or vice versa), and this restores the initial signal (which is the essence of skyrmion echo).

The expression profile of lung long non-coding RNAs and mRNAs in a mouse model of smoke inhalation injury.

To study the potential expression of lung long non-coding RNAs (lncRNAs) and mRNAs during smoke inhalation injury (SII), using a SII mouse model that we created in our previous work. Microarray was used to investigate the lncRNAs and mRNAs profiles. A bioinformatics analysis was performed. Changes in the top 10 down-regulated and 10 up-regulated lncRNAs were validated using Quantitative Reverse Transcription-PCR (RT-qPCR). The acute lung injury (ALI) mouse model was successfully induced by smoke inhalation, as confirmed by the aberrantly modified cell numbers of red blood cells and neutrophils counts, increased levels of TNF-α, IL-1ß, Bax, caspase-7, caspase-3, and decreased Bcl-2 content in lung tissues. When compared to the control mice, 577 lncRNAs and 517 mRNAs were found to be aberrantly expressed in the SII mice. According to the Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, the altered mRNAs were enriched in acute-phase response, oxidoreductase activity, oxidation-reduction process, glutathione metabolism, the wnt signaling pathway, and ferroptosis. A lncRNA-related competitive endogenous RNA (ceRNA) network, including 383 lncRNAs, 318 MicroRNAs (miRNAs), and 421 mRNAs specific to SII, was established. The changes in NONMMUT026843.2, NONMMUT065071.2, ENSMUST00000235858.1, NONMMUT131395.1, NONMMUT122516.1, NONMMUT057916.2, and NONMMUT013388.2 in the lung matched the microarray results. Our findings help to provide a more comprehensive understanding of the pathogenesis of SII as well as new insights into potential therapeutic targets.

Tandem mass tag-based serum proteomic profiling revealed diabetic foot ulcer pathogenesis and potential therapeutic targets.

Diabetic foot ulcer (DFU), one of the most serious complications of diabetes mellitus, is associated with a high amputation rate and decreased life quality. The impact of blood serum proteins on the occurrence and development of DFU has attracted a lot of interest. In this study, we aimed to define and compare the serum proteome of patients with DFU and healthy control (HC) to provide new insights into DFU pathogenesis. DFU patients and age- and sex-matched HCs were enrolled in this study (n = 54). We screened alterations in blood serum proteins from DFU patients and HC using a tandem mass tag (TMT) method based on liquid chromatography-mass spectrometry (LC-MS/MS) quantitative proteomics, and the differentially expressed proteins (DEPs) were further validated by parallel reaction monitoring (PRM) and enzyme-linked immunosorbent assay (ELISA). A total of 173 DEPs (100 up-regulated and 73 down-regulated) were identified between the DFU and HC groups (P < 0.05). Proteomic and bioinformatics analyses indicated that the proteins in the DFU group were mainly related to extracellular matrix (ECM)-receptor interaction and complement and coagulation cascades. The up-regulated DEPs were further verified by PRM and ELISA. LRG1, CD5L, CRP, IGHA1, and LBP were proved upregulated in DFU and these proteins are mainly related to immune response and complement activation. Our findings help to provide a more comprehensive understanding of the pathogenesis of DFU and new insight into potential therapeutic targets.

Magnonic Unidirectional Spin Hall Magnetoresistance in a Heavy-Metal-Ferromagnetic-Insulator Bilayer.

We report the observation of the unidirectional spin Hall magnetoresistance (USMR), which depends on the current or magnetization direction, in heavy-metal-ferromagnetic-insulator bilayer, Pt-Y_{3}Fe_{5}O_{12} (YIG). This USMR is apparently not caused by the mechanisms established in metallic bilayer, in which the ferromagnetic layer is required to be electrically conductive. From the magnetic field, current, temperature, and YIG thickness dependent measurements, the USMR is attributed to the asymmetric magnon creation and annihilation induced by the spin-orbit torque. This asymmetry and the resultant USMR are further revealed by the micromagnetic simulations combined with the spin-orbit torque and the spin drift-diffusion model. Our finding exhibits a nonlinear manipulation of magnons with the charge current.

Negative-pressure wound therapy in skin grafts: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Although skin grafts are widely used in reconstruction of large skin defect and complex wounds, many factors lead to suboptimal graft take. Negative-pressure wound therapy (NPWT) reportedly increases the graft take rates when added to skin grafting, but a summary analysis of the data of randomized controlled trials has yet to be performed. We conducted this systematic review and meta-analysis of randomized controlled trials to compare the effectiveness and safety of NPWT and non-NPWT for patients with skin grafts. METHODS: We searched PubMed, Embase, Cochrane Library, and CNKI for relevant trials based on predetermined eligibility criteria from database establishment to February 2020. Two reviewers screened citations and extracted data independently. The quality of the included studies was evaluated according to the Cochrane Handbook, whereas statistical heterogeneity was assessed using chi-square tests and I2 statistics. Review Manager 5.3 was used for statistical analysis. RESULTS: Ten randomized controlled trials with 488 patients who underwent NPWT or non-NPWT were included. Compared with non-NPWT, NPWT yielded an improved the percentage of graft take, a reduction in days from grafting to discharge, with lower relative risk of re-operation, and no increased relative risk of adverse event. Further, the subgroup analysis showed an improved the percentage of graft take in negative pressure of 80 mmHg, and no improved the percentage of graft take in negative pressure of 125 mmHg. CONCLUSION: NPWT is more effective than non-NPWT for the integration of skin grafts, and the negative pressure of 80 mmHg can be recommended. Data on adverse events and negative pressure are, however, limited. A better understanding of complications after NPWT and the ideal negative pressure for the integration of skin grafts is imperative.

Steering magnonic dynamics and permeability at exceptional points in a parity-time symmetric waveguide.

Tuning the magneto optical response and magnetic dynamics are key elements in designing magnetic metamaterials and devices. This theoretical study uncovers a highly effective way of controlling the magnetic permeability via shaping the magnonic properties of coupled magnetic waveguides separated by a nonmagnetic spacer with strong spin-orbit interaction (SOI). We demonstrate how a spacer charge current leads to enhancement of magnetic damping in one waveguide and a decrease in the other, constituting a bias-controlled magnetic parity-time (PT) symmetric system at the verge of the exceptional point where magnetic gains/losses are balanced. We find phenomena inherent to PT-symmetric systems and SOI-driven interfacial structures, including field-controlled magnon power oscillations, nonreciprocal propagation, magnon trapping and enhancement as well as an increased sensitivity to perturbations and abrupt spin reversal. The results point to a new route for designing magnonic waveguides and microstructures with enhanced magnetic response.

Na-Based monolayer photocatalysts with an extremely high intrinsic electric-field for water splitting.

A strong built-in electric field, high carrier mobility and a wide range of optical absorption values are the key parameters for photocatalysts used in water splitting. The design and preparation of photocatalysts possessing simultaneously these characteristics have always been the main tasks in the water splitting field. Here, we report a new family of 2D Na-based photocatalysts, NaAB2 (A = Al, Ga, In; B = S, Se, Te) monolayers, which may achieve this goal. First-principles calculations show that most of the NaAB2 monolayers are semiconductors with a suitable direct band gap ranging from visible to near-infrared light, exhibiting good optical absorption. The electron mobilities of the NaAB2 monolayers are up to 103 cm2 V-1 s-1, meaning the rapid migration of electrons can promote photocatalytic overall water splitting. Importantly, the electrostatic potential differences between the top surface and the bottom surface are larger than 1.23 eV for all the studied NaAB2 monolayers, meaning a high intrinsic built-in electric field that is present in these Na-based photocatalysts can promote the overall water splitting irrespective of their band gaps and band edges. Our studies show that the NaAB2 monolayers may be ideal photocatalysts for use in water splitting and may initiate a new round of experimental studies.

BMSC-derived exosomes alleviate smoke inhalation lung injury through blockade of the HMGB1/NF-κB pathway.

AIMS: To investigate the role of bone marrow mesenchymal stem cell (BMSC)-derived exosomes in smoke inhalation lung injury. MAIN METHODS: In this study, we initially isolated exosomes from BMSCs and identified them by western blot and transmission electron microscopy. BMSC-derived exosomes were then used to treat in vitro and in vivo models of smoke inhalation lung injury. Pathologic alterations in lung tissue, the levels of inflammatory factors and apoptosis-related factors, and the expression of HMGB1 and NF-κB were determined to evaluate the therapeutic effect of BMSC-derived exosomes. KEY FINDINGS: We found that BMSC-derived exosomes could alleviate the injury caused by smoke inhalation. Smoke inhalation increased the levels of inflammatory factors and apoptosis-related factors and the expression of HMGB1 and NF-κB, and these increases were reversed by BMSC-derived exosomes. HMGB1 overexpression abrogated the exosome-induced decreases in inflammatory factors, apoptosis-related factors and NF-κB. SIGNIFICANCE: Collectively, these results indicate that BMSC-derived exosomes can effectively alleviate smoke inhalation lung injury by inhibiting the HMGB1/NF-κB pathway, suggesting that exosome, a noncellular therapy, is a potential therapeutic strategy for inhalation lung injury.

Stem cell derived exosomes-based therapy for acute lung injury and acute respiratory distress syndrome: A novel therapeutic strategy.

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common critical disease which can be caused by multiple pathological factors in clinic. However, feasible and effective treatment strategies of ALI/ARDS are limited. At present, the beneficial effect of stem cells (SCs)-based therapeutic strategies for ALI/ARDS can be attributed to paracrine. Exosomes, as a paracrine product, are regarded as a critical regulatory mediator. Furthermore, substantial evidence has indicated that exosomes from SCs can transmit bioactive components including genetic material and protein to the recipient cells and provide a protective effect. The protective role is played through a series of process including inflammation modulation, the reconstruction of alveolar epithelium and endothelium, and pulmonary fibrosis prevention. Therefore, SCs derived exosomes have the potential to be used for therapeutic strategies for ALI/ARDS. In this review, we discuss the present understanding of SCs derived exosomes related to ALI/ARDS and provide insights for developing a cell-free strategy for treating ALI/ARDS.

Efficacy and Safety of Intralesional Triamcinolone Versus Combination of Triamcinolone with 5-Fluorouracil in the Treatment of Keloids and Hypertrophic Scars: A Systematic Review and Meta-analysis.

BACKGROUND: Although keloids and hypertrophic scars are common benign hyperproliferative growths of dermal fibroblasts, the clinical problems including physical and psychological problems are significant and impairing, with few proven treatments. Intralesional triamcinolone acetonide (TAC) and combination of TAC with 5-fluorouracil (5-FU) are widely used to treat keloids and hypertrophic scars, but their efficacy and safety remain controversial. METHODS: We systematically searched MEDLINE, EMBASE, Cochrane Library, and CNKI for relevant trials. RESULTS: The mean scar height and the erythema score in the TAC + 5-FU group were lower than those in the TAC group after treatment (P < 0.05). The effectiveness based on observer assessment after treatment in the TAC + 5-FU group was superior than that in the TAC group (P < 0.05); further, the subgroup analysis showed the TAC + 5-FU group was also superior than the TAC group in the treatment of hypertrophic scars (P = 0.01), and there were no significant differences in the treatment of keloid (P = 0.12). The effectiveness based on patient self-assessment after treatment in the TAC + 5-FU group was also superior than the TAC group (P < 0.05). The overall complication rate in the TAC + 5-FU group was lower than the TAC group (P < 0.05). CONCLUSIONS: Combination of TAC with 5-FU is more effective and safer than TAC alone therapy in the treatment of keloids and hypertrophic scars. Data on keloids alone or hypertrophic scars alone are, however, limited. A better understanding of effective after intralesional combination of TAC with 5-FU in the treatment of keloids alone or hypertrophic scars alone is imperative. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A case report of a woman after childbirth with a dehisced abdominal wound as well as fat liquefaction and large skin necrosis.

Recently high-frequency electric knife and abdominal binder are widely used in the abdominal operation in China. Nevertheless, with the high occurrence of the abdominal wound, we think that whether both these operations could be used or not. Here, we report the case of a 40-year-old female patient where negative pressure wound therapy (NPWT) was applied to her dehisced abdominal wound as well as fat liquefaction and large skin necrosis with pleasing results. The patient with high fever was referred to our department from her earlier hospital for 6 days after cesarean delivery. During the surgery, her earlier doctor used a high-frequency electric knife for convenient-using, and after the operation, the patient immediately used an abdominal binder for good shape. However, the abdominal surgical incision was opened at postoperative day 3, with fat liquefaction releasing large fatty acids along both abdominal sides with penetration under the abdominal binder. After admitted at postoperative day 6 with aggravating wound, surgery was considered because of no reduction in the size of the wound. A series of vacuum sealing drainage (VSD) or vacuum-assisted closure (VAC) as well as others, were operated. In the admitted 25th day, the wound was completely closed. NPWT is a practical and effective therapy for the treatment of numerous refractory and intractable wounds. Therefore, we suggest that the high-frequency electric knife and an abdominal binder should be avoided using an abdominal operation. This case is the first report of the use of NPWT over a dehisced abdominal wound with fat liquefaction and large skin necrosis on a postpartum patient in China.

The Safety and Efficacy of Intralesional Verapamil Versus Intralesional Triamcinolone Acetonide for Keloids and Hypertrophic Scars: A Systematic Review and Meta-analysis.

BACKGROUND: Keloids and hypertrophic scars often result after skin trauma. Currently, intralesional triamcinolone acetonide (TAC) is the criterion standard in nonsurgical management of keloids and hypertrophic scars. Intralesional verapamil may be an effective alternative modality, but it has been insufficiently studied. Accordingly, the study authors conducted a systematic review and meta-analysis of randomized controlled trials to compare the efficacy and safety of the two drugs. METHODS: The study authors systematically searched the MEDLINE, EMBASE, Cochrane Library, and China National Knowledge Infrastructure databases for relevant trials published in any language through September 2018. RESULTS: According to the four studies included in this review, TAC improved scar pliability and vascularity more than verapamil after 3 weeks (P < .05). For scar height and scar pigmentation, no statistical difference was observed between the treatments (P > .05). The difference in effects on symptoms was not statistically significant (P = .89). For pain and telangiectasia, no statistical difference was observed (P > .05). Verapamil resulted in fewer cases of skin atrophy (P < .05). CONCLUSIONS: It appears that TAC is more effective than verapamil for improving scar pliability and vascularity in keloids and hypertrophic scars after 3 weeks of treatment. However, verapamil has fewer adverse drug reactions than TAC, which allows for a longer treatment period and the possibility that it might be effective for patients who cannot receive TAC.

Sinus Wounds Management.

With aging populations and the increased incidence of cerebrovascular disease, diabetes, and other diseases, more and more patients suffer from pressure injuries. Pressure injuries are often difficult to heal because of the presence of sinus tracts, which make it difficult to clean and change dressings. Sinus wounds are common in patients with pressure injuries, but also occur after abdominal wall incision and in patients who have experienced a physical trauma that created a wound. It is difficult for clinicians to observe, evaluate, and repair sinus wounds because of the small surface defect and large and deep basement of each wound. This article reviews existing assessment methods and treatments for sinus wounds and proposes a new evaluation method and treatment (three-dimensional reconstruction and endoscopic techniques) to further improve treatment and provide better quality of care for patients with this type of wound.

Early anticoagulation therapy for severe burns complicated by inhalation injury in a rabbit model.

The aim of the present study was to determine the effects of early anticoagulation treatment on severe burns complicated by inhalation injury in a rabbit model. Under anesthetization, an electrical burns instrument (100˚C) was used to scald the backs of rabbits for 15 sec, which established a 30% III severe burns model. Treatment of the rabbits with early anticoagulation effectively improved the severe burns complicated by inhalation injury­induced lung injury, reduced PaO2, PaCO2 and SPO2 levels, suppressed the expression of tumor necrosis factor­α, interleukin (IL)­1ß and IL­6, and increased the activity of IL­10. In addition, it was found that early anticoagulation treatment effectively suppressed the activities of caspase­3 and caspase­9, upregulated the protein expression of vascular endothelial growth factor (VEGF) and decreased the protein expression of protease­activated receptor 1 (PAR1) in the severe burns model. It was concluded that early anticoagulation treatment affected the severe burns complicated by inhalation injury in a rabbit model through the upregulation of VEGF and downregulation of PAR1 signaling pathways. Thus, early anticoagulation is a potential therapeutic option for severe burns complicated by inhalation injury.

Spin-dependent transport properties of zigzag phosphorene nanoribbons with oxygen-saturated edges.

We investigate the electronic structures and electronic transport properties of zigzag phosphorene nanoribbons with oxygen-saturated edges (O-zPNRs) by using the spin-polarized density functional theory and the nonequilibrium Green's function method. The results show that the O-zPNR is an antiferromagnetic (AFM) or ferromagnetic (FM) semiconductor with spins localized at two ribbon edges anti-parallel or parallel with each other. The electronic transmission for the single AFM or FM O-zPNR is zero when a bias voltage is applied to the two electrodes made of the same type O-zPNR. Nonzero transmission arises for the AFM-AFM and FM-FM O-zPNR heterojunctions. The transmission spectrum and the electrical current are fully spin polarized for the FM-FM O-zPNR heterojunction. An in-plane transverse electrical field can effectively manipulate the electronic structure and spin-dependent electronic transport. It induces splitting of the spins of the two edges and makes the AFM O-zPNR become a half metal. Moreover, the transverse electrical field gives rise to the transmission spectrum and the spin polarized electrical current for the AFM-AFM O-zPNR heterojunction. The degree of spin polarization can be tuned by the strength of the transverse field.

Domain wall motion driven by adiabatic spin transfer torque through excitation of nonlinear dynamics.

Domain wall dynamics under the joint action of a linearly polarized microwave magnetic field and spin transfer torque was analysed in terms of the domain wall collective coordinates. It was found that a microwave-assisted steady domain wall motion driven by adiabatic spin transfer torque can be adequately described by three domain wall collective coordinates. Analytical expression for the domain wall velocity showed that there are two contributions to the steady domain wall motion. One is derived from the nonlinear oscillation of domain wall width excited by the microwave field, and the other is from the heterodyne process between the width oscillation and the microwave field. The former always propels a domain wall to move in the positive direction, which is defined as the direction of the applied current. The latter contribution to the domain wall velocity can be positive or negative, depending on the polarization of the microwave field. The final domain wall velocity is determined by the competition between those two contributions, which indicates that by simply changing the polarization of the microwave field, the direction of the domain wall motion can be reversed. Our analysis demonstrated that the characteristics of domain wall motion can be tuned by selective excitation of nonlinear domain wall dynamics.

Expression levels of matrix metalloproteinase-9 in human gastric carcinoma.

The present report investigated the correlation between the expression levels of matrix metalloproteinase (MMP)-9 in gastric carcinoma patients and the clinicopathological characteristics. Forty-five samples of gastric carcinoma and distal gastric mucosa tissue, and 10 samples of healthy gastric mucosa tissue were analyzed using semi-quantitative polymerase chain reaction, as well as immunohistochemical and hematoxylin and eosin staining. MMP-9 protein levels in serum samples from the same patients were quantified by enzyme-linked immunosorbent assay. The present report identified that MMP-9 expression was markedly higher in the gastric carcinoma tissue (86.67%) than in the adjacent healthy tissue (10.00%). A positive association was identified between the level of MMP-9 protein expression and the depth of cancer invasion (P<0.05). Furthermore, the preoperative serum levels of the MMP-9 protein in the gastric carcinoma tissue were correlated with the tumor-node-metastasis stage and occurrence of lymph node metastasis (P<0.01). Data from the present report indicates that MMP-9 may be key in gastric carcinoma malignancy, and implies that MMP-9 may serve as a novel biomarker in the diagnosis and prognosis of gastric carcinoma.