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Vicinal Co atoms modulate the electronic structure of the Fe site and adsorption behaviour of the intermediates, boosting ORR performance.

The low-grade heat source thermoelectric system generates electricity using a working fluid at temperature lower than 100°C or gas at temperature lower than 250°C. The system is usually composed of binary (1 + 0.5 × 2) cycles. Positive net output power or high efficiency of the system can only be feasible after optimization. Most works focused on the cycle of working fluid and treated the power consumptions of the other cycles as constants. However, both cycles should be comprehensively considered in optimization, especially when power consumptions vary with working conditions. This research selected an organic Rankine cycle thermoelectric system for demonstration. A thermodynamic model conforming to the target system was built. The temperature of the heat source and the pressure at expander inlet were tailored using the genetic algorithm. The best efficiency is 1.89%, and the largest net output power is 5.80 kW. Both results are better than those (efficiency = 1.59% and net output power = 5.34 kW) from benchmarks under the highest temperature of heat source and inlet pressure among possible working conditions. Experimental results are provided for both validation of the model and confirmation of the superiority of optimization results.

Multiple hydropower reservoirs operation is an effective measure to rationally allocate the limited water resources under uncertainty. With the rapid expansion of water resources system, it becomes much more difficult for traditional methods to quickly yield the reasonable operational policy. Grey wolf optimizer, inspired by the wolves’ hunting behaviors, is a famous metaheuristic method to resolve engineering optimization problems, but still suffers from the local convergence and search stagnation defects. To alleviate this problem, this study proposes a hybrid grey wolf optimizer (HGWO) where the hyperbolic accelerating strategy is introduced to improve the local search ability; the adaptive mutation strategy is used to diversify the swarm; the elitism selection strategy is used to enhance the convergence speed. The experimental results show that the HGWO method can produce better solutions than its original version in several test functions. Then, the HGWO method is applied to resolve the optimal operation of a real-world hydropower system with the goal of maximizing the total generation benefit. The simulations indicate that the HGWO method produces satisfying scheduling schemes than several control methods in terms of all the statistical indicators. Hence, with the merits of superior search ability, rapid convergence rate and gradient information avoidance, HGWO proves to be a promising alternative optimization tool for the complex multireservoir system operation problem.

Background Evidence suggests that glucocorticoids are important in the treatment of sudden hearing loss (SHL) and Meniere’s disease (MD). However, different glucocorticoid administration methods may have a significant impact on treatment outcomes. Objective This study aimed to investigate effects of different glucocorticoid administration methods on sudden hearing loss and Meniere’s disease. Methods In this study, glucocorticoids were administered orally in 18 patients, by retroauricular injection in 15 patients and by intratympanic injection in 15 patients. White blood cell (WBC) count, serum K+, fasting plasma glucose (FPG), body temperature, heart rate and blood pressure were used to evaluate effects of glucocorticoids on patients with hearing loss. Visual analog scale (VAS) of pain and sleep disorders were also surveyed, and pure tone audiometry (PTA) results were compared among groups to evaluate efficacy of different glucocorticoids administration methods. Result WBC count, heart rate and blood pressure were higher in patients taking oral glucocorticoids, while body temperature, serum K+ and FPG levels did not change in all three groups. However, patients who received intratympanic injection of glucocorticoids experienced more pain, while those taking oral glucocorticoids reported more sleep impairment. Treatment efficacy on hearing loss was not significantly different among the three groups. Conclusion These findings suggest that systemic glucocorticoid administration can result in greater whole body responses than local administration, but with similar hearing treatment efficacy.

The Fe reduction, microstructure evolution and corrosion susceptibility of Mg−Mn alloys made from magnesium scrap refining with Mn addition were investigated. The results show that significant Fe content change occurs during near-solid-melt treatment (NSMT) process even in the absence of Mn, because of the high saturation of Fe in the melt. Furthermore, in the NSMT process, even a small amount of Mn addition can lead to a sharp deposition of Mn atoms. The NSMT process can increase the growth rate of the Fe-rich particles, and then accelerate their sinking movement. Nevertheless, the addition of Mn hinders the coarsening process of Fe-rich particles. Besides, the corrosion susceptibility of the alloys is mainly affected by the solubility of Fe, which can be significantly reduced by Mn addition. Moreover, the presence of more Fe-rich particles does not necessarily increase the corrosion susceptibility of the alloy. Consequently, in the refining process of Mg−Mn alloys made from magnesium scrap, on the basis of NSMT process and adding an appropriate Mn content (about 0.5 wt.%), the purity of the melt can be improved, thereby obtaining an alloy with excellent corrosion resistance.

Photodynamic therapy (PDT) is a promising non-invasive therapy approach for various diseases including malignant tumor. The process of PDT involves three interrelated aspects, namely photosensitizer (PS), light source, and oxygen, among which PS is the decisive factor that determines its anticancer efficiency. There exist some defects in currently applied PDT, such as inadequate production of reactive oxygen species (ROS), poor penetration of exciting light, insufficient oxygen supply, and nonselective distribution of PS. With unique physicochemical and optical properties, two-dimensional nanomaterials (2DNMs) have aroused great interest in biomedical fields. 2DNMs-based PDT is promising to significantly improve antitumor efficacy compared to conventional PDT. In this review, we will firstly introduce the underlying mechanism of PDT and how 2DNMs are absorbed and distribute inside tumor cells. After that, we will not only illustrate how 2DNMs-based PDT can enhance tumor-killing efficacy and minimize side-effects through conquering the above-mentioned defects of conventional PDT and the preparation process of 2DNMs, but also elaborate recent advances about 2DNMs-based PDT. Lastly, we will summarize the challenges and future prospects of 2DNMs-based PDT.

This work aims to propose a promising locally resonating system consisting of a tensioned elastic membrane and two-arch masses attached on the membrane surface. Traditional membrane-type resonators, which usually create one obvious attenuation zone at low frequencies, might not be efficient in multi-frequency vibration suppression. The proposed structure can produce an extra clear flexural attenuation region and shift bandgap frequencies below 300 Hz. By adjusting geometric parameters (thickness, width, and location) of the arch mass, the bandgap region can be tuned. Introducing a feasible analytical model for accurately predicting the first and second initial frequencies of the bandgaps for a beam structure containing membrane-arch-mass resonators is another focus of this study. The proposed theoretical framework can be used to tune the bandgap to different target frequency ranges without knowing the actual width of the bandgap. Finite-element analysis and experiments are conducted to verify the theoretical predictions. A good agreement is seen among the theoretical, finite-element analysis, and experimental results. In addition, adjacent cells with different arch-mass distributions can generate two pairs of flexural bandgaps, increasing the practicality in engineering applications. The proposed structure might be used in low-frequency vibration isolation and filters.

Selenoprotein K (SELENOK), an endoplasmic reticulum (ER) resident protein, is regulated by dietary selenium and expressed at a relatively high level in neurons. SELENOK has been shown to participate in oxidation resistance, calcium (Ca2+) flux regulation, and the ER-associated degradation (ERAD) pathway in immune cells. However, its role in neurons has not been elucidated. Here, we demonstrated that SELENOK gene knockout markedly enhanced ER stress (ERS) and increased apoptosis in neurons. SELENOK gene knockout elicited intracellular Ca2+ flux and activated the m-calpain/caspase-12 cascade, thus inducing neuronal apoptosis both in vivo and in vitro. In addition, SELENOK knockout significantly reduced cognitive ability and increased anxiety in 7-month-old mice. Our findings reveal an unexpected role of SELENOK in regulating ERS-induced neuronal apoptosis.

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Fluid-coupled Lamb waves (LWs) were proposed to facilitate the self-assembling of three-dimensional (3D) photonic crystals (PCs) in this work. Numerical models were constructed for proof-of-concept, and a fabrication set-up was developed for experimental demonstration. LWs were initially generated by a piezoelectric substrate. A couplant altered the propagating direction of these LWs to form the fluid-coupled LWs at a superstrate. The coffee-ring effect (CRE) of a suspension droplet on the superstrate was thus suppressed. The suspended nanospheres formed 3D PCs after the droplet dried out. Diversified PCs were fabricated using the developed set-up. Their transmittance spectra demonstrated the corresponding bandgap clearly. Advantages of utilizing fluid-coupled LWs for self-assembling 3D PCs include flexibility in excitation frequency, fabrication cost-effectiveness, acceptance for a passively oscillating substrate, and enlargement of sample area.

This study aims to explore the feasibility of endoscopic transcanal push-trough myringoplasty (ETPM) for all types of tympanic membrane perforations (TMPs), and compare the outcomes with those of endoscopic type 1 tympanoplasty (ETT) with meatal flap elevation.A prospective, controlled study.In the present study, inpatients with TMPs were divided into two groups according to the manner of tympanic membrane repair: one group received ETPM without raising the meatal flap, and the other received ETT. The operation duration, postoperative healing rate, visual analogue scale (VAS) of pain, and complication rates were compared between these two groups.Regardless of the size and location of the perforation, and its relationship with the malleus manubrium, myringoplasty can be completed using the ETPM method. The operation duration for different types of TMPs was shorter in the ETPM group than in the ETT group, and the difference was statistically significant (p0.05). However, there was no statistical difference in the short-term healing rate (p0.05) and pain VAS score (p0.05) between these two groups. Furthermore, no intraoperative or postoperative complications occurred in both groups.ETPM without raising the meatal flap can be applied for all types of TMPs, regardless of how large the perforation is, or where it is located. This can shorten the operation duration, and has a high healing rate comparable to ETT and mild postoperative pain. Mastering some essential surgical skills under the endoscope would be helpful to ensure the success of the surgery.

Energy consumption for cooling and heating buildings should be reduced in the future to maintain suitable indoor thermal comfort at a lower cost. Numerical simulation of heat transfer within building systems can help to design the energy-efficient buildings. This article presents a fundamental theoretical research done to understand the effect of automation of the underfloor heating system in a room under the influence of ambient conditions on heat transfer. The considered physical process has been described mathematically taking into account the turbulent natural convection and thermal surface radiation within an air filled enclosure having a panoramic window. Sinusoidal boundary condition has been applied to the external surface of panoramic window to model the possible diurnal ambient temperature oscillation. An automation of the underfloor heating system is determined by the heater volumetric heat flux that magnitude depends on the ambient conditions. The governing equations with boundary conditions have been solved numerically by the finite-difference method. The influence of the relevant parameters, viz., surface emissivity, length of underfloor heating system and ambient boundary conditions has been investigated in detail. Distributions of integral and local characteristics illustrating flow and thermal structures in the large-scale enclosure have been studied. The contribution of the thermal radiative mechanism to the overall heat transfer is close in magnitude to the convective heat transfer even under normal room conditions.

This work set up a Lamb wave excitation device for assembling polystyrene nanospheres into 3D photonic crystals (PCs) of face-centered cubic structures. The optical property of fabricated PCs was verified by transmittance spectra measurements.

Introduction: Enhanced recovery after surgery (ERAS) protocols are a series of perioperative care to optimize preoperative preparation, prevent postoperative complications, minimize stress, and speedup recovery. Tympanoplasty and mastoidectomy are common surgical procedures for chronic suppurative otitis media. Objective: To compare the efficacy and safety between ERAS and conventional recovery after surgery in the perioperative period of chronic suppurative otitis media. Methods: From April 2018 to February 2019, a total of 84 patients scheduled for tympanoplasty and/or mastoidectomy due to chronic suppurative otitis media were involved and randomly divided into the ERAS group and the control group. The patients’ preoperative anxiety, postoperative pain, and comfort level were determined by comparing the results of Self-Rating Anxiety Scale (SAS), Visual Analog Scale (VAS) and General Comfort Questionnaire (GCQ). The postoperative complications, postoperative hospital stay, and hospitalization cost were calculated. Results: The ERAS group showed a lower SAS score (30 [28-31.5] vs 35 [30-43], P < .05], a higher GCQ score (88 [84-100] vs 83 [78.25-92.25], P < .05), and a lower VAS score (0 [0-0] vs 1 [0-2], P < .05] after surgery. No significant difference ( P > .05) was observed between the ERAS group and the control group in postoperative complications, postoperative hospitalization time, and hospitalization cost, respectively. Conclusion: Enhanced recovery after surgery can reduce pain and improve comfort in the perioperative period of chronic suppurative otitis media.

Recently metamaterials made of periodic nanowire arrays, multilayers, and grating structures have been studied for near-field thermal radiation with enhanced coupling of evanescent waves due to surface plasmon/phonon polariton, hyperbolic mode, epsilon-near-zero and epsilon-near-pole (ENP) modes, guided mode, and wave interference. In this work, both effective uniaxial electric permittivity and magnetic permeability of a nanowire-based metamaterial are retrieved theoretically through the far-field radiative properties obtained by finite difference time-domain (FDTD) simulations. The artificial magnetic response of metamaterials, which cannot be obtained by traditional effective medium theory (EMT) based on electric permittivity of constitutes only, is successfully captured by the nonunity magnetic permeability, whose resonant frequency is verified by an inductor-capacitor model. By incorporating the retrieved electric permittivity and magnetic permeability into fluctuational electrodynamics with multilayer uniaxial wave optics, the near-field radiative heat transfer between the metallic nanowire arrays is theoretically studied and spectral near-field heat enhancements are found for both transverse electric and magnetic waves due to artificial magnetic resonances. The understanding and insights obtained here will facilitate the application of metamaterials in near-field radiative transfer.

A highly active and stable Fe3C-containing Fe/N/C catalyst, derived from a cationic Cd(ii)-based metal-organic framework involving accurate control over Fe-doping via anion-exchange with potassium ferricyanide, shows superior oxygen reduction performance over the benchmark Pt/C catalyst in an alkaline electrolyte.

Background As an important means of communication, exosomes play an important role in the development of hepatocellular carcinoma (HCC). Methods Bioinformatics analysis, dual-luciferase reporter assays, methylation-specific quantitative PCR, and ChIP-PCR analysis were used to gain insight into the underlying mechanism of miR-21 in HCC. Results The detection of miRNAs in exosomes of HCC showed that miR-21 expression in exosomes was positively correlated with the expression level of miR-21 in cells and negatively correlated with the expression of its target genes PTEN, PTENp1 and TETs. HCC cell-derived exosomes could increase miR-21 and p-Akt expression in HCC cells and downregulate the expression of PTEN, PTENp1 and TETs. MiR-21 inhibitors or PTENp1 overexpression vectors could weaken the effect of the abovementioned exosomes and simultaneously weaken their role in promoting cell proliferation and migration and inhibiting apoptosis. Further studies showed that miR-21 not only directly regulated the expression of PTEN, PTENp1 and TETs but also increased the methylation level of the PTENp1 promoter by regulating the expression of TETs, thereby inhibiting the expression of PTENp1 and further downregulating the expression of PTEN. Conclusions Exosomal miR-21 can regulate the expression of the tumor suppressor genes PTEN and PTENp1 in various ways and affect the growth of HCC cells.

Objectives/hypothesis To investigate the simultaneous application of cartilage tympanoplasty combined with eustachian tube (ET) balloon dilatation in the treatment of adhesive otitis media (AdOM). Study design Multicenter, prospective, double-blind, randomized, controlled clinical trial. Methods Patients with AdOM were randomly divided into four groups: control group (conservative treatment), ET balloon dilatation (ETBD) group, cartilage tympanoplasty (CT) group, and cartilage tympanoplasty combined with ET balloon dilatation (ETBD+CT) group. Patients were followed up at 3 months, 6 months, 1 year, and 2 years after treatment, receiving otoendoscopy and pure-tone audiometry, and were evaluated using the Tinnitus Handicap Inventory (THI), visual analogue scale (VAS) for the symptom of ear stuffiness, Chronic Otitis Media Outcome Test (COMOT-15), and eustachian tube scores (ETS). Results There was no improvement in tympanic membrane (TM) morphology and mean pure-tone air-bone gap (ABG) after treatment in the control and ETBD groups. The postoperative TM morphology was improved in the CT group and ETBD+CT group, although retraction pockets reoccurred in two cases of CT group. Reduced ABG and improvements in ETS, THI, VAS, and COMOT-15 were all achieved in these two groups, but the difference was not statistically significant. Conclusions Cartilage tympanoplasty combined with ET balloon dilatation could be used as an appropriate surgical technique for AdOM, which could relieve the symptoms of tinnitus and ear stuffiness, and improve postoperative TM morphology, hearing level, ET functions, and quality of life, with low incidence of complications. Level of evidence 2 Laryngoscope, 129:1462-1467, 2019.

Purpose Adult chronic otitis media with effusion (COME) is characterized by Eustachian tube dysfunction and mucosal inflammation, which management has long been a challenge because of high recurrence. This study was to investigate the pathological changes of Eustachian tube mucosa and optimized treatment. Materials and methods Retrospective study of four groups: I: tympanic paracentesis, II: balloon Eustachian tuboplasty (BET), III: BET plus tympanic paracentesis, IV: BET and tympanic paracentesis with methylprednisolone irrigation. Biopsy of Eustachian tube mucosa was obtained preoperative and 1 month post. Recurrence ratio and Eustachian tube scores (ETS) were used to evaluate the effect of treatments. Results All patients showed narrowed with edematous and thickened Eustachian tube mucosa. At 1 month post-treatment, BET with methylprednisolone irrigation significantly decreased intraepithelial inflammation and restored the quality of epithelium and cilia. For group II to IV, The recurrence rate was significantly lower in group IV compared with the other two, but only significantly lower in group IV VS group II at 3 months and 6 months, no significant difference at 12 months. The recurrence rate was significantly higher in group I during follow-up. The ETS were improved in group II, III and IV after treatment. At 1 month and 3 months posttreatment, group IV had significant higher ETS compared with other groups (P Conclusion Methylprednisolone irrigation could help to recover mucosal function. BET and tympanic paracentesis with methylprednisolone irrigation could be regarded as a good choice for COME in adults, which has less recurrence rate and prompt recovery of ET function.

Synchronous scattering and diffraction were demonstrated using reflectance from gold nanotextured surfaces at oblique (θi = 15° and 60°) incidence of wavelength λ = 405 nm. Two samples of unique auto-correlation functions were cost-effectively fabricated. Multiple structure factors of their profiles were confirmed with Fourier expansions. Bi-directional reflectance function (BRDF) from these samples provided experimental proofs. On the other hand, standard deviation of height and unique auto-correlation function of each sample were used to generate surfaces numerically. Comparing their BRDF with those of totally random rough surfaces further suggested that structure factors in profile could reduce specular reflection more than totally random roughness.

The refractive index and the extinction coefficient (optical constants) are essential in photonic design and thermal radiation utilization. These constants vary with the material phase, temperature, wavelength, and subject dimension. However, precisely retrieving these constants from a thin film is challenging at elevated temperatures and therefore temperature dependency is usually neglected. To tackle this challenge, a methodology for retrieval using emittance at different emission angles, θ, is developed here. The method contains four steps and takes advantage of emissometry. The method is firstly validated using simulation and then its feasibility is demonstrated by retrieving optical constants of a phase-change germanium-antimony-tellurium (Ge2Sb2Te5, GST) film. Emittance from samples at 100 °C, 200 °C, 300 °C, and 400 °C is measured at θ = 0°, 15°, and 30°. The spectral range of retrieval covers from 4 μm to 18 μm where thermal radiation dominates. The investigated film considers amorphous, face-centered cubic, and hexagonal close packed phases. The retrieved constants exhibit temperature and substrate independence, but they show a significant phase reliance.

This work investigated the phenomena and cause of photonic band gap (PBG) shift under an open environment at −10 °C ∼ 20 °C for the three-dimensional (3D) photonic crystals (PCs). The 3D PCs were composed of polystyrene spheres using the self-assembly method. The reflective gloss of 3D PC sample underwent non-monotonous color change within the temperature region. PBG of PCs first red-shifted during the cooling from room temperature. Later, the PBG blue-shifted when the temperature decreased from about 0 °C. The average transmittance through the PC sample within the visible range also increased first and then decreased with ambient temperature reduction. Influences from structure dimension, optical constants of involved materials, condensation and its phase change on PBG were all quantitatively investigated.

A photonic hook (PH) is a high-intensity, curved focusing beam with a subwavelength waist based on the photonic nanojet effect. It is generally created by illuminating mesoscale transparent particles using optical plane waves. In this work, we numerically explore the generation of the PH supported by the Janus microcylinder under point-source illumination. To simulate the photonic intensity distributions near the shadow surface of the Janus microcylinder, a finite-difference time-domain technique is used. The power flow distributions near the Janus microcylinder are examined for working in the visible spectrum. Due to the asymmetric vortices of Poynting vectors, the PH with a large bending angle can be produced. By changing the location of the point-source illumination, the shape and curvature of the PH can be adjusted efficiently. Moreover, when the point-source illumination is located close to the Janus microcylinder, a long focal length PH can be present. Based on the numerical results, we propose a practical modeling scheme for optical imaging using a microscope where the light source is close to the target.

Chitosan, β-glycerophosphate, and glycerol are all biocompatible materials for biomedical application. This work successfully developed a thermosensitive hydrogel composed of CS, β-GP and glycerol. The CS/β-GP/glycerol hydrogel can be made as a transparent solution at room temperature and becomes an opaque and turbid hydrogel after heating. The transmission of visible light at different temperature can be measured by a visible micro spectrophotometer combined with a precise temperature control of the demountable liquid cell. A tunable transmission of visible light hydrogel was developed. Moreover, the composition of such hydrogel is safely used and it is potential for biomedical applications.

Summary This work experimentally studies a silicon-cored tungsten nanowire selective metamaterial absorber to enhance solar-thermal energy harvesting. After conformally coating a thin tungsten layer about 40 nm thick, the metamaterial absorber exhibits almost the same total solar absorptance of 0.85 as the bare silicon nanowire stamp but with greatly reduced total emittance down to 0.18 for suppressing the infrared emission heat loss. The silicon-cored tungsten nanowire absorber achieves an experimental solar-thermal efficiency of 41% at 203°C during the laboratory-scale test with a stagnation temperature of 273°C under 6.3 suns. Without parasitic radiative losses from side and bottom surfaces, it is projected to reach 74% efficiency at the same temperature of 203°C with a stagnation temperature of 430°C for practical application, greatly outperforming the silicon nanowire and black absorbers. The results would facilitate the development of metamaterial selective absorbers at low cost for highly efficient solar-thermal energy systems., Graphical Abstract, Highlights • Si-cored tungsten nanowires are fabricated by conformal coating of 40-nm tungsten • Total solar absorptance of 0.85 with greatly reduced total emittance is achieved • Solar-thermal efficiency of 41% at 203°C under 6.3 suns is measured • 74% efficiency at 203°C with a stagnation temperature of 430°C is projected, Thermal Engineering; Thermal Property; Nanomaterials; Energy Materials