Quantitative and morphological differences of nerve fibers between proliferative and mature scars in two-and three-dimensional spaces

BACKGROUND： Numerous studies use fluorescent microscopy to obtain two-dimensional optical images of the morphology of nerve fibers in hypertrophic scars. In addition, current confocal microscopy studies have focused on normal, not pathological, cutaneous nerves. However, laser scanning confocal microscopy results in a three-dimensional structure of the nerve fibers. OBJECTIVE： To observe quantitative and morphological differences in nerve fibers from the proliferative and mature stage in hypertrophic scars using fluorescent and confocal microscopy. DESIGN, TIME AND SETTING： Neuropathological, comparison study was conducted at the Provincial Hospital Affiliated to Shandong University, China from June 2006 to July 2007. PARTICIPANTS： Specimens were selected from 30 patients undergoing scar restoration at the Provincial Hospital Affiliated to Shandong University of China at 1 month to 23 years following wound healing. The study comprised 20 males and 10 females. The scars were fibrous lesions, erythematous, tough, confined to skin lesions, did not exhibit ulceration or infection, exhibited telangiectasia, with or without itching and pain, and were not locally treated. Samples were equally assigned to two groups according to course of disease： proliferative group （〈 6 months） and mature group （6-24 months）. Control samples were collected from full-thickness skin from donor sites （n = 10）. METHODS： Nerve fiber morphology was observed using fluorescent and confocal microscopy following immunofluorescence of the skin specimens. The microscopic images were semi-quantitatively analyzed to acquire a positive area ratio of neurofilament protein-positive nerve fibers. MAIN OUTCOME MEASURES： Morphology and positive area ratio of neurofilament protein/positive nerve fibers was measured. RESULTS： The positive area ratio of neurofilament protein-positive nerve fibers was significantly greater in the proliferative group compared to the normal control group （P 〈 0.05）. Nerve fibers were irregularly distributed and exhibited local swelling, twisting, and disconnection. However, the positive area ratio of neurofilament protein-positive nerve fibers was significantly less in the mature group compared with the normal control group （P 〈 0.05）. The nerve fibers were arranged in an orderly manner, with intact inner and stereoscopic structures similar to normal skin. CONCLUSION： Compared with mature scars, hypertrophic scars exhibited a greater number of nerve fibers, with more serious pathologies.

Remodeling of skin nerve fibers during burn wound healing

Burn wound healing involves a complex sequence of processes. Recent studies have revealed that skin reinnervation may have an impact on physiological wound repair. Few studies have addressed the process of reinnervation and morphological changes in regenerated nerve fibers. The regeneration of neurites during full-thickness burn wound healing was determined by immunofluorescent staining using an anti-neurofilament protein monoclonal antibody, and three-dimensional morphology was observed under a laser scanning confocal microscope. Morphology and the volume fraction of collagen and nerve fibers were measured. Skin reinnervation increased during wound healing, peaked during the proliferative scar stage, and then decreased to lower levels during the maturation period. The results from the skin nerve fibers correlated with those from collagen using semi-quantitative analysis. Disintegration and fragmentation were observed frequently in samples from the proliferative stage, and seldom occurred during the maturation stage. There was a remodeling process of regenerated nerve fibers during wound healing, which comprised changed innervation density and topical morphology. The mechanism of remodeling for nerve fibers requires further investigation.

Mechanical tension promotes skin nerve regeneration by upregulating nerve growth factor expression

This study aimed to explore the role of mechanical tension in hypertrophic scars and the change in nerve density using hematoxylin-eosin staining and S100 immunohistochemistry, and to observe the expression of nerve growth factor by western blot analysis. The results demonstrated that mechanical tension contributed to the formation of a hyperplastic scar in the back skin of rats, in conjunction with increases in both nerve density and nerve growth factor expression in the scar tissue. These experimental findings indicate that the cutaneous nervous system plays a role in hypertrophic scar formation caused by mechanical tension.

Skin nerve regeneration and burn wound healing following spinal nerve root incision

Burn wounds were produced on two sides on the backs of Wistar rats, in addition to denervation on one side. The skin neural regeneration at the injury site and burn wound healing were evaluated following spinal nerve root incision. No nerve regeneration was observed in the burn wound region post-denervation, and the degree of epithelization was significantly less than the control group. With increasing time, expression of type I collagen, which plays a supporting role, and collagen III, which exhibits elastJc propertJes, were sJgnificantly increased Jn the two groups, but the expression was less in the denervation group compared with the control group, and the wound healing was faster in the control group. The ratio of type I collagen to type III collagen was significantly lower in the denervation group compared with the control group. The ratio gradually decreased with prolonged time in the denervation group, but remained unchanged in the control group. However, the elasticity of the tissues in the denervation group was better than the control group. During burn wound healing, innervations can promote wound healing, but denervation can improve the quality of wound remodeling.

Facile synthesis of defect-rich Fe-N-C hybrid from fullerene/ferrotetraphenylporphyrin as efficient oxygen reduction electrocatalyst for Zn-air battery

Exploring remarkable oxygen reduction reaction(ORR)electrocatalysts for regenerative fuel cells and metal-air batteries is highly essential.Herein,a novel non-noble metal-based heterogeneous electrocatalyst with rich defects were successfully synthesized by liquid-liquid interfacial precipitation(LLIP)of fullerene(C_(60))and ferrotetraphenylporphyrin(FeTPP)followed by one step pyrolysis.The obtained product annealed at 700℃(C_(60)/FeTPP-700),when employed as ORR electrocatalyst,revealed a positive halfwave potential(E_(1/2))of 0.877 V vs.reversible hydrogen electrode(RHE),which was superior to that of the commercial 25%Pt/C.Delightfully,the assembled Zn-air battery(ZAB)using C_(60)/FeTPP-700 as an air-electrode catalyst exhibited a high power density of 153 m W/cm^(2),specific capacity of 668 mAh/g and long-term cycling stability for more than 250 h.Experimental results proved that the excellent electrocatalytic ORR activity of C_(60)/FeTPP-700 would attribute to the synergistic effect between FeN_xsites,Fe_(3)C/Fe nanoparticles and the structure defects.This work provides a feasible and simple method to prepare nonnoble metal-based ORR electrocatalysts for the application of energy storage and conversion.

Effect of Image Noise on the Classification of Skin Lesions Using Deep Convolutional Neural Networks

Skin lesions are in a category of disease that is both common in humans and a major cause of death.The classification accuracy of skin lesions is a crucial determinant of the success rate of curing lethal diseases.Deep Convolutional Neural Networks(CNNs)are now the most prevalent computer algorithms for the purpose of disease classification.As with all algorithms,CNNs are sensitive to noise from imaging devices,which often contaminates the quality of the images that are fed into them.In this paper,a deep CNN(Inception-v3)is used to study the effect of image noise on the classification of skin lesions.Gaussian noise,impulse noise,and noise made up of a compound of the two are added to an image dataset,namely the Dermofit Image Library from the University of Edinburgh.Evaluations,based on t-distributed Stochastic Neighbor Embedding(t-SNE)visualization,Receiver Operating Characteristic(ROC)analysis,and saliency maps,demonstrate the reliability of the Inception-v3 deep CNN in classifying noisy skin lesion images.

掺杂钴、氮、硫、磷的碳骨架作为电化学析氧反应的高效催化剂（英文）

本文提出了一种制备碱性介质中电化学析氧反应高效催化剂的新方法.该方法选用一种含钴的碳-氮聚合物网络作为结构模板,外面包裹一层原位制备的、含硫和磷的超支化交联聚合物.450℃煅烧2 h后,获得可用于电化学析氧反应的、内部交联、微观呈现层状结构的催化剂.该催化剂在1.0 molL^(-1)的氢氧化钾水溶液中表现出很好的电化学催化活性和高稳定性.电子衍射图谱(EDS)和X-射线光电子能谱(XPS)研究表明该催化剂含有痕量钴及其他杂原子,包括氮、硫、磷,且证实了能够大幅提高催化活性的Co–N和Co–O活性物质的存在.将钴替换为铜和镍之后,催化剂的催化活性大大降低,表明当前方法对钴基催化剂的制备最为有效.煅烧过程中所选用的温度对催化剂的催化活性亦有显著影响,450℃为最优温度.这些结果表明,含钴的、杂原子(硫、磷)掺杂的碳氮化物有望成为一类新的电解水催化剂,以取代贵金属氧化物,或作为其有益的补充.

Dual modulation of morphology and electronic structures of VN@C electrocatalyst by W doping for boosting hydrogen evolution reaction

Developing high-efficiency and robust durability electrocatalyst for hydrogen evolution reaction(HER)in water electrolysis functions as a crucial role for the construction of green hydrogen economy,herein,ultrafine W-doped vanadium nitride nanoparticles anchored on N-doped graphitic carbon framework(WVN@NGC)are synthesized through a one-step simple pyrolysis protocol.Owing to the enlarged catalytically active sites,enhanced electrical conductivity and optimized electronic structure,the resultant VN/WN@NGC delivered the prominent HER performance with overpotentials of 143 mV and 158 mV at10 mA/cm^(2) in acid and alkaline media,respectively,accompanied by the long-term stability for at least50 h.This work highlights a novel strategy for a metal-triggered modulation of nitride-based HER electrocatalyst for sustainable energy conversion device.

Phase-mediated cobalt phosphide with unique core-shell architecture serving as efficient and bifunctional electrocatalyst for hydrogen evolution and oxygen reduction reaction

Hydrogen evolution reaction(HER)and oxygen reduction reaction(ORR)have been considered as two critical processes in the field of electrocatalytic water-splitting for hydrogen production and fuel cells.However,the sluggish reaction kinetics of HER and ORR required efficient electrocatalyst such as Pt to promote such process.Transition metal phosphides(TMPs)exhibit great potential to replace noble metal electrocatalysts to accelerate HER and ORR due to their high activity and easy availability.Herein,a highly-efficient bifunctional CoP electrocatalyst for HER and ORR,featuring a unique core-shell structure decorated on nitrogen-doped carbon matrix was designed and constructed via etching a cobalt-based zeolitic imidazolate framework(ZIF-67)with phytic acid(PA)followed by pyrolysis treatment(PA-ZIF-67-900).Experimental results revealed that the pure-phase single-crystalline Co P exhibited outstanding electrocatalytic performance in HER and ORR,superior to Co(PO_(3))_(2) in PA-ZIF-67-700,hybrid phase of Co(PO_(3))_(2) and CoP in PA-ZIF-67-800 and Co_(2)P-doped CoP in PA-ZIF-67-1000.To reach the current density of 10 mA/cm^(2)the as-synthesized Co P required an overpotential of 120 m V for HER in 1 mol/L KOH and half-wave potential of 0.85 V in O_(2)-saturated 0.1 mol/L KOH.This work present new clue for construction of efficient and bifunctional electrocatalyst in the field of energy conversion and storage.