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OBJECTIVE: To explore the safety, feasibility, and technical points of the improved circumcision procedure assisted by a precise marking method circumcision device. METHOD: A retrospective analysis was conducted on 41 cases of modified foreskin circumcision using precise marking method in the urology department of our hospital from February 2021 to January 2023 as the observation group, and 60 cases of traditional foreskin circumcision assisted by traditional foreskin circumcision during the same period as the control group. Compare and analyze indicators such as the distance from the anastomotic margin to the coronal sulcus, postoperative erectile tension, edema, hematoma, postoperative infection, and the presence of sexual intercourse pain between two groups of patients. The number of patients in the observation group who experienced erectile tension at 3 months after surgery was lower than that in the control group (P<0.05), and the number of patients with sexual pain was lower than that in the control group (P<0.05). The distance from the incision edge to the coronal sulcus was closer to 0.5 cm in the observation group (P<0.05). CONCLUSION: Compared with traditional circumcision, the precise marking method assisted by a modified circumcision device can more accurately control the position of the cutting edge, reduce the incidence of postoperative erectile tension and sexual pain, and is a feasible and safe surgical method.
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Circuncisão Masculina , Fimose , Masculino , Humanos , Prepúcio do Pênis/cirurgia , Estudos Retrospectivos , Fimose/cirurgia , DorRESUMO
Mesocarbon microbeads (MCMB) are highly desirable as anode materials for rechargeable potassium ion batteries (PIBs) due to their commercially availability, high stability and low-cost. However, their charge storage and interfacial mechanisms are still unclear. In this work, the intercalation mechanisms and the solid-electrolyte-interphase (SEI) formation of the MCMB in four different electrolytes is comprehensively studied. The MCMB anodes exhibit superior rate and cycle performances via a naked K-ions sequentially staging intercalation mechanism, realizing the complete transformation from graphite to KC8 . Whereas a solvated K-ions co-intercalation mechanism of the MCMB occurs in ether-based electrolytes, which might induce graphite exfoliation and result in unsatisfied specific capacity and capacity decay. Nevertheless, this co-intercalation behavior could be effectively suppressed by a highly concentrated electrolytes. Interfacial analyses unveil the distinct SEI components, which vary with the electrolyte chemistries. These SEI components also varies from surface to bulk and especially attention should be paid to the accurate control of the concentration of the fluoroethylene carbonate additives. This work provides a panoramic understanding of the intercalation and interfacial mechanisms on the MCMB anodes for PIBs.
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It is essentially important to improve the performance of Zn-air batteries by studying bifunctional catalysts for oxygen evolution reactions (OER) and oxygen reduction reactions (ORR) with low-cost, high-efficiency and high-stability properties. Here, CoNi nanoparticles embedded in the bamboo-like N-doped carbon tubes (Co x Ni y @NC) were synthesized, where the optimized catalyst of Co2Ni1@NC exhibits superior bifunctional electrocatalytic activity, showing a low overpotential of 300 mV under the current density of 10 mA cm-2 for OER and a large limiting current density of 3.76 mA cm-2 under 0.40 V for ORR in an alkaline solution. In addition, the Co2Ni1@NC also shows excellent electrocatalytic activity in acidic and neutral solutions. Importantly, primary Zn-air batteries based on Co2Ni1@NC affords an excellent specific capacity of 834 mAh/gZn with a discharge potential of 1.25 V at 5 mA cm-2. A rechargeable Zn-air battery assembled with Co2Ni1@NC shows excellent cycling stability, where the first discharge and charge voltages reach 1.21 and 2.00 V under 1 mA cm-2, respectively. This finding provides a simple synthesis approach, which allows one to construct bifunctional catalysts based on metal@NC for future energy conversion and storage devices.
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Monodisperse SiO2/TiO2 yolk-shell nanospheres (YSNSs) with different SiO2 core sizes were fabricated and adopted as dispersing materials for electrorheological (ER) fluids to investigate the influence of the gradual structural change of disperse particles on ER properties. The results showed that the ER performance of the YSNS-based ER fluid prominently enhanced with the decrease of SiO2 core size, which was attributed to the enhancement of electric field force between YSNSs. Combined with the analysis of dielectric spectroscopy, it was found that the increase of permittivity at low frequency (10(-2)-10(0) Hz) was due to the increase of polarized charges caused by secondary polarization (Psp). Moreover, the number of Psp closely related to the distributing change of polarized particles in ER fluid was a critical factor to assess the ER performance. Additionally, a parameter K (the absolute value of the slope of permittivity curves at 0.01 Hz) could be utilized to characterize the efficiency of structural evolution of polarized particles in ER fluid. Compared with the ER performance, it could be concluded that the value of Δε(100Hz-100kHz)' just demonstrated the initial intensity of the interface polarization in the ER fluid as the electric field was applied, which ignored the distributing evolution of polarized disperse particles in ER fluid. The polarizability Δε(0.01Hz-100kHz)' obtained in the frequency range of 10(-2)-10(5) Hz should be more suitable for analyzing the system of ER fluid. The relationships between polarizability of disperse particles, parameter K and ER properties were discussed in detail.
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Espectroscopia Dielétrica , Eletricidade , Nanosferas/química , Reologia , Dióxido de Silício/química , Titânio/químicaRESUMO
Preceding vehicle detection and tracking at nighttime are challenging problems due to the disturbance of other extraneous illuminant sources coexisting with the vehicle lights. To improve the detection accuracy and robustness of vehicle detection, a novel method for vehicle detection and tracking at nighttime is proposed in this paper. The characteristics of taillights in the gray level are applied to determine the lower boundary of the threshold for taillights segmentation, and the optimal threshold for taillight segmentation is calculated using the OTSU algorithm between the lower boundary and the highest grayscale of the region of interest. The candidate taillight pairs are extracted based on the similarity between left and right taillights, and the non-vehicle taillight pairs are removed based on the relevance analysis of vehicle location between frames. To reduce the false negative rate of vehicle detection, a vehicle tracking method based on taillights estimation is applied. The taillight spot candidate is sought in the region predicted by Kalman filtering, and the disturbed taillight is estimated based on the symmetry and location of the other taillight of the same vehicle. Vehicle tracking is completed after estimating its location according to the two taillight spots. The results of experiments on a vehicle platform indicate that the proposed method could detect vehicles quickly, correctly and robustly in the actual traffic environments with illumination variation.
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Automóveis , Reconhecimento Automatizado de Padrão , Algoritmos , Humanos , LuzRESUMO
Rechargeable magnesium batteries are particularly advantageous for renewable energy storage systems. However, the inhomogeneous Mg electrodeposits greatly shorten their cycle life under practical conditions. Herein, the epitaxial electrocrystallization of Mg on a three-dimensional magnesiophilic host is implemented via the synergy of a magnesiophilic interface, lattice matching, and electrostatic confinement effects. The vertically aligned nickel hydroxide nanosheet arrays grown on carbon cloth (abbreviated as "Ni(OH)2@CC") have been delicately designed, which satisfy the essential prerequisite of a low lattice geometrical misfit with Mg (about 2.8%) to realize epitaxial electrocrystallization. Simultaneously, the ionic crystal nature of Ni(OH)2 displays a periodic and hillock-like electrostatic potential field over its exposed facets, which can precisely capture and confine the reduced Mg0 species onto the local electron-enriched sites at the atomic level. The Ni(OH)2@CC substrate undergoes sequential Mg-ion intercalation, underpotential deposition, and electrocrystallization processes, during which the uniform, lamellar Mg electrodeposits with a locked crystallographic orientation are formed. Under practical conditions (10 mA cm-2 and 10 mAh cm-2), the Ni(OH)2@CC substrate exhibits stable Mg stripping/plating cycle performances over 600 h, 2 orders of magnitude longer than those of the pristine copper foil and carbon cloth substrates.
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Metal sulfides have attracted tremendous research interest for developing high-performance electrodes for potassium-ion batteries (PIBs) for their high theoretical capacities. Nevertheless, the practical application of metal sulfides in PIBs is still unaddressed due to their intrinsic shortcomings of low conductivity and severe volume changes during the potassiation/depotassiation process. Herein, robust Fe7S8/C hybrid nanocages reinforced by defect-rich MoS2 nanosheets (Fe7S8/C@d-MoS2) were designed, which possess abundant multichannel and active sites for potassium-ion transportation and storage. Kinetic analysis and theoretical calculation verify that the introduction of defect-rich MoS2 nanosheets dramatically promotes the potassium-ion diffusion coefficient. The ex-situ measurements revealed the potassium-ion storage mechanism in the Fe7S8/C@d-MoS2 composite. Benefitting from the tailored structural design, the Fe7S8/C@d-MoS2 hybrid nanocages show high reversible capacity, exceptional rate property, and superior cyclability.
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Titanium dioxide and Nb-doped titanium dioxide microspheres with the same size were fabricated by a simple sol-gel method, and the formation mechanism of Nb-doped titanium dioxide microspheres was proposed. Titanium dioxide and Nb-doped titanium dioxide microspheres were adopted as dispersed materials for electrorheological (ER) fluids to investigate the influence of the charge increase introduced by Nb doping on the ER activity. The results showed that Nb doping could effectively enhance the ER performance. Combining with the analysis of dielectric spectroscopy, it was found that the interface polarization of Nb-doped TiO2 ER fluid was larger than that of TiO2 ER fluid, which might be caused by more surface charges in Nb-TiO2 microspheres due to Nb(5+) doping and resulting in enhancement of electric field force and strengthening of fibrous structure. In addition, by comparing and analyzing the permittivity curves of Nb-TiO2/LDPE solid composite and Nb-TiO2/silicone-oil fluid composite, it could be concluded that the enhancement of permittivity at low frequency resulted from the increase of the order degree of dispersed particles in ER fluid rather than from the quasi-dc (QDC) behavior. Moreover, the absolute value of slope of permittivity curves (K) at 0.01 Hz could be utilized as the standard for judging the ability to maintain the chainlike structure. The relationships between polarizability of dispersed particles, dielectric spectrum, parameter K, and ER properties were discussed in detail.
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Carbon nanotubes and carbon nanobelts were obtained via single-needle electrospinning on a basis of water-in-oil (W/O) emulsion technique, respectively. The morphology of electrospun products can be controlled by controlling the temperature of the collector during the electrospinning process. The mechanism of fabricating PAN nanotubes and nanobelts by emulsion electrospinning is discussed in detail. Transmission electron microscopy and scanning electron microscope results show that the carbon nanotubes (the inner diameter of 25-50 nm and the outer diameter of 50-100 nm) have a wall thickness of 10-50 nm, and the width and thickness of the nanobelts range from 100 to 300 nm, and 1 to 5 nm, respectively. A slight difference of bonding configuration of the carbon nanofibers, carbon nanotubes and carbon nanobelts is attributed partly to their different topological structures. The novel method is versatile and could be extended to the fabrication of various types of nanotubes and nanobelts.
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Cristalização/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Polímeros/química , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
ZnO/HfO(2):Eu nanocables were prepared by radio frequency sputtering with electrospun ZnO nanofibers as cores. The well-crystallized ZnO/HfO(2):Eu nanocables showed a uniform intact core-shell structure, which consisted of a hexagonal ZnO core and a monoclinic HfO(2) shell. The photoluminescence properties of the samples were characterized. A white-light band emission consisted of blue, green, and red emissions was observed in the nanocables. The blue and green emissions can be attributed to the zinc vacancy and oxygen vacancy defects in ZnO/HfO(2):Eu nanocables, and the yellow-red emissions are derived from the inner 4f-shell transitions of corresponding Eu(3+) ions in HfO(2):Eu shells. Enhanced white-light emission was observed in the nanocables. The enhancement of the emission is ascribed to the structural changes after coaxial synthesis.