Graphene has shown great potential in microwave absorption(MA) owing to its high surface area, low density,tunable electrical conductivity and good chemical stability.To fully realize graphenes& MA ability, the mi...Graphene has shown great potential in microwave absorption(MA) owing to its high surface area, low density,tunable electrical conductivity and good chemical stability.To fully realize graphenes& MA ability, the microstructure of graphene should be carefully addressed. Here we prepared graphene microflowers(Gmfs) with highly porous structure for high-performance MA filler material. The efficient absorption bandwidth(reflection loss B-10 dB) reaches 5.59 GHz and the minimum reflection loss is up to -42.9 dB, showing significant increment compared with stacked graphene. Such performance is higher than most graphene-based materials in the literature. Besides, the low filling content(10 wt%) and low density(40–50 mg cm^(-3))are beneficial for the practical applications. Without compounding with magnetic materials or conductive polymers,Gmfs show outstanding MA performance with the aid of rational microstructure design. Furthermore, Gmfs exhibit advantages in facile processibility and large-scale production compared with other porous graphene materials including aerogels and foams.展开更多
Biomedical field has been seeking a feasible standard drug screening system consisting of 3D tumor model array for drug researching due to providing sufficient samples and simulating actual in vivo tumor growth situat...Biomedical field has been seeking a feasible standard drug screening system consisting of 3D tumor model array for drug researching due to providing sufficient samples and simulating actual in vivo tumor growth situation,which is still a challenge to rapidly and uniformly establish though.Here,we propose a novel drug screening system,namely 3D tumor array chip with“layer cake”structure,for drug screening.Accurate gelatin methacryloyl hydrogel droplets(~0.1μL)containing tumor cells can be automatically deposited on demand with electrohydrodynamic 3D printing.Transparent conductive membrane is introduced as a chip basement for preventing charges accumulation during fabricating and convenient observing during screening.Culturing chambers formed by stainless steel and silicon interlayer is convenient to be assembled and recycled.As this chip is compatible with the existing 96-well culturing plate,the drug screening protocols could keep the same as convention.Important properties of this chip,namely printing stability,customizability,accuracy,microenvironment,tumor functionalization,are detailly examined.As a demonstration,it is applied for screening of epirubicin and paclitaxel with breast tumor cells to confirm the compatibility of the proposed screening system with the traditional screening methods.We believe this chip will potentially play a significant role in drug evaluation in the future.展开更多
Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healt...Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healthy subjects were recruited in this study. We measured ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) in these subjects by air-conduction sound (ACS) stimulation. CHL was simulated later by blocking the right external auditory canal with a soundproof earplug to evaluate its impacts on VEMPs. Subjects' responses before simulated CHL served as the control, and were compared to their responses following simulated CHL. Results: oVEMPs following simulated CHL showed decreased response rate, elevated thresholds, attenuated amplitudes and prolonged N1 latencies compared with those before simulated CHL, and the differences were statistically significant. Similarly, cVEMPs following simulated CHL also showed decreased response rate, elevated thresholds and attenuated amplitudes, with prolonged P1 latencies compared with those before simulated CHL, although only differences in response rate, threshold and amplitude were significant. Conclusions:Conductive hearing loss affects the response rate and other response parameters in oVEMPs and cVEMPs.展开更多
Objective: To observe the otolithic function in sudden sensorineural hearing loss (SSHL) patients in different age groups by using vestibular evoked myogenic potentials (VEMPs). Methods: One hundred and seventy unilat...Objective: To observe the otolithic function in sudden sensorineural hearing loss (SSHL) patients in different age groups by using vestibular evoked myogenic potentials (VEMPs). Methods: One hundred and seventy unilateral SSHL patients were divided into 5 age groups. The 170 affected ears belonged to study group. The opposite healthy ears of 170 patients and 138 normal ears of 69 age and sex-matched normal people at different ages were set as control groups. Ocular VEMP (oVEMP) and cervical VEMP (cVEMP) both evoked by air-conducted sound (ACS) were employed for vestibular otolithic function assessment. Results: The response rates of cVEMP and oVEMP were lower and abnormal rates were higher in affected ears of SSHL patients compared to the opposite healthy ears and normal control ears in all age groups, except patients over 60 years. The response rates of VEMPs significantly declined with increasing age, not only in normal control ears, but also in affected and healthy ears of SSHL patients. But, the abnormal rates of VEMPs showed no significant difference in affected ears at different ages. Conclusions: Dysfunction of vestibular otolithic organs in SSHL patients presented respective features at different ages. It is necessary to consider the age when the clinicians determine the otolithic condition of patients based on the VEMPs.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21325417 and 51533008)National Key R&D Program of China (No. 2016YFA0200200)Fundamental Research Funds for the Central Universities (2017XZZX008-06)
文摘Graphene has shown great potential in microwave absorption(MA) owing to its high surface area, low density,tunable electrical conductivity and good chemical stability.To fully realize graphenes& MA ability, the microstructure of graphene should be carefully addressed. Here we prepared graphene microflowers(Gmfs) with highly porous structure for high-performance MA filler material. The efficient absorption bandwidth(reflection loss B-10 dB) reaches 5.59 GHz and the minimum reflection loss is up to -42.9 dB, showing significant increment compared with stacked graphene. Such performance is higher than most graphene-based materials in the literature. Besides, the low filling content(10 wt%) and low density(40–50 mg cm^(-3))are beneficial for the practical applications. Without compounding with magnetic materials or conductive polymers,Gmfs show outstanding MA performance with the aid of rational microstructure design. Furthermore, Gmfs exhibit advantages in facile processibility and large-scale production compared with other porous graphene materials including aerogels and foams.
基金This work was sponsored by the National Nature Science Foundation of China(No.U1609207)the National Key Research and Development Program of China(2018YFA0703000)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51521064).
文摘Biomedical field has been seeking a feasible standard drug screening system consisting of 3D tumor model array for drug researching due to providing sufficient samples and simulating actual in vivo tumor growth situation,which is still a challenge to rapidly and uniformly establish though.Here,we propose a novel drug screening system,namely 3D tumor array chip with“layer cake”structure,for drug screening.Accurate gelatin methacryloyl hydrogel droplets(~0.1μL)containing tumor cells can be automatically deposited on demand with electrohydrodynamic 3D printing.Transparent conductive membrane is introduced as a chip basement for preventing charges accumulation during fabricating and convenient observing during screening.Culturing chambers formed by stainless steel and silicon interlayer is convenient to be assembled and recycled.As this chip is compatible with the existing 96-well culturing plate,the drug screening protocols could keep the same as convention.Important properties of this chip,namely printing stability,customizability,accuracy,microenvironment,tumor functionalization,are detailly examined.As a demonstration,it is applied for screening of epirubicin and paclitaxel with breast tumor cells to confirm the compatibility of the proposed screening system with the traditional screening methods.We believe this chip will potentially play a significant role in drug evaluation in the future.
基金supported by grants from the National Natural Science Foundation of China, China (No. 81670945, 81541040)Fundamental Research Funds for the Central Universities, China (No. 2012jdhz13)+1 种基金Shaanxi Major International Cooperative Project, China (No. 2013KW-28)Key Science and Technology Program of Xi'an, China (No. SF1315(1))
文摘Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healthy subjects were recruited in this study. We measured ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) in these subjects by air-conduction sound (ACS) stimulation. CHL was simulated later by blocking the right external auditory canal with a soundproof earplug to evaluate its impacts on VEMPs. Subjects' responses before simulated CHL served as the control, and were compared to their responses following simulated CHL. Results: oVEMPs following simulated CHL showed decreased response rate, elevated thresholds, attenuated amplitudes and prolonged N1 latencies compared with those before simulated CHL, and the differences were statistically significant. Similarly, cVEMPs following simulated CHL also showed decreased response rate, elevated thresholds and attenuated amplitudes, with prolonged P1 latencies compared with those before simulated CHL, although only differences in response rate, threshold and amplitude were significant. Conclusions:Conductive hearing loss affects the response rate and other response parameters in oVEMPs and cVEMPs.
文摘Objective: To observe the otolithic function in sudden sensorineural hearing loss (SSHL) patients in different age groups by using vestibular evoked myogenic potentials (VEMPs). Methods: One hundred and seventy unilateral SSHL patients were divided into 5 age groups. The 170 affected ears belonged to study group. The opposite healthy ears of 170 patients and 138 normal ears of 69 age and sex-matched normal people at different ages were set as control groups. Ocular VEMP (oVEMP) and cervical VEMP (cVEMP) both evoked by air-conducted sound (ACS) were employed for vestibular otolithic function assessment. Results: The response rates of cVEMP and oVEMP were lower and abnormal rates were higher in affected ears of SSHL patients compared to the opposite healthy ears and normal control ears in all age groups, except patients over 60 years. The response rates of VEMPs significantly declined with increasing age, not only in normal control ears, but also in affected and healthy ears of SSHL patients. But, the abnormal rates of VEMPs showed no significant difference in affected ears at different ages. Conclusions: Dysfunction of vestibular otolithic organs in SSHL patients presented respective features at different ages. It is necessary to consider the age when the clinicians determine the otolithic condition of patients based on the VEMPs.
