Zinc Oxide

氧化锌
  • 文章类型: Journal Article
    随着工业化速度的加快,传统能源正处于枯竭的困境中。人类迫切需要清洁能源来维护和平与发展。摩擦电纳米发电机(TENG)是一种收集和转换可再生能源的微型设备,如风,振动和潮汐/蓝色能量,转化为电能。作为TENG最重要的工作原理,接触电气化(CE)已被广泛研究,因为它被记录在几千年前。报道了大量相关研究。然而,他们中的大多数都集中在聚合物材料上,器件结构和潜在应用。关于CE机制的文献很少,尤其是在半导体-半导体的情况下。半导体-半导体CE是一种有前途的发电方法,已经在许多领域使用,如光电探测器和位移传感器。因此,有必要建立一个严肃而详细的理论,以深入解释半导体-半导体CE的潜在机制。在这项工作中,提出了一种基于能带理论的费米能级模型来说明半导体-半导体CE机制。通过组装ZnO/Si垂直接触分离(CS)模式TENG,系统地测量CE引入的电荷转移。根据能带理论和TENG控制方程,对实验数据进行了定性和定量分析。此外,研究了不同浓度的生长溶液对ZnO纳米线形貌的影响以及ZnO与Si的费米能级差。结果表明,费米能级差主导了半导体-半导体CE机制的短路转移电荷量和方向。我们的工作可以应用于理解半导体-半导体情况下的CE机理,并拓宽基于半导体的TENG的应用前景。
    With the speed of industrialization accelerating, the traditional energy is in the predicament of being exhausted. Humans urgently need a clean energy to maintain the peace and development. Triboelectric nanogenerator (TENG) is a tiny device that collects and converts the renewable energy, such as wind, vibration and tidal/blue energy, into electrical energy. As the most significant working principle of TENG, contact electrification (CE) has been broadly studied since it was documented thousands of years ago. A large number of related researches are reported. However, most of them are focused on the polymer materials, device structures and potential applications. There are few literatures about the mechanism of CE, especially in the semiconductor-semiconductor case. Semiconductor-semiconductor CE is a promising method to generate electricity, which has been used in many fields, such as the photodetector and displacement sensor. Therefore, it is necessary to establish a serious and detailed theory in order to deeply explain the underlying mechanisms of semiconductor-semiconductor CE. In this work, a novel Fermi level model based on energy band theory is proposed to illustrate the semiconductor-semiconductor CE mechanism. By assembling a ZnO/Si vertical contact-separation (CS) mode TENG, the charge transfer introduced by CE is systematically measured. According to the energy band theory and TENG governing equation, the experimental data is qualitatively and quantitatively analyzed. Moreover, the effects of different concentrations of growth solutions on the morphology of ZnO nanowires and the Fermi level difference between ZnO and Si are explored as well. Results show that it is the Fermi level difference that dominates the short circuit transfer charge amount and direction of semiconductor-semiconductor CE mechanism. Our work can be applied to understand the CE mechanism in semiconductor-semiconductor case and broaden the application prospects of semiconductor-based TENG.
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  • 文章类型: Journal Article
    太阳能非均相光催化用于去除饮用水中的三卤甲烷(THM)。THMs,主要是三氯甲烷(TCM),三溴甲烷(TBM),溴二氯甲烷(BDCM)和二溴氯甲烷(DBCM)是一类主要的消毒副产物(DBPs)。通过HSGC-MS测定THM,TCM和BDCM的检出限(LODs)为0.5μgL-1至0.9μgL-1,分别。结果表明,存在于水中的大部分THM最终由于其高挥发性而以TCM>BDCM>DBCM>TBM的顺序转移到空气中。与光解测试相比,使用带隙半导体材料(TiO2和主要是ZnO)作为光催化剂,结合使用Na2S2O8作为电子受体和硫酸根阴离子(SO4•-)发生器增强了所有THM的光氧化。最有效治疗(ZnO/Na2S2O8)计算的50%的THM从水中消失(DT50)所需的时间为TCM的12、42、57和61分钟,TBM,BDCM,和DBCM,分别。因此,太阳能非均相光催化可以被认为是一种有趣的THMs去除策略,尤其是在地中海盆地等阳光充足的地区。
    Solar heterogeneous photocatalysis was used to remove trihalomethanes (THMs) from drinking water. THMs, mainly trichloromethane (TCM), tribromomethane (TBM), bromodichloromethane (BDCM) and dibromochloromethane (DBCM) are one of the main class of disinfection by-products (DBPs). THMs were determined by HSGC-MS with detection limits (LODs) ranging from 0.5 μg L-1 to 0.9 μg L-1 for TCM and BDCM, respectively. Results show that a great proportion of THMs present in water are finally transferred to air as a result of their high volatility in the order TCM > BDCM > DBCM > TBM. The use of band-gap semiconductor materials (TiO2 and mainly ZnO) used as photocatalysts in combination with Na2S2O8 as electron acceptor and sulfate radical anion (SO4•-) generator enhanced the photooxidation of all THMs as compared to photolytic test. The time required for 50% of THMs to disappear (DT50) from water calculated for the most effective treatment (ZnO/Na2S2O8) were 12, 42, 57 and 61 min for TCM, TBM, BDCM, and DBCM, respectively. Therefore, solar heterogeneous photocatalysis can be considered as an interesting strategy for THMs removal, especially in sunny areas like Mediterranean basin.
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  • 文章类型: Journal Article
    PRKCSH,也称为葡萄糖苷酶IIβ,通过在严重的环境压力下以p53依赖性方式调节细胞周期,从而发挥肺肿瘤发生的作用。然而,目前尚不清楚PRKCSH在癌细胞中显著升高的预后价值和分子机制.这里,我们首先通过分析来自癌症数据库的生物信息学数据,生成了癌症中PRKCSH表达变化的生物学图谱.我们发现,在肺癌患者中,较高的PRKCSH表达与较差的预后和大多数免疫细胞类型的浸润有关。特别是,肺癌组织中PRKCSH的表达与STAT6水平呈显著负相关(r=-0.31,p<0.001)。我们进一步发现,PRKCSH缺乏促进了A549细胞对氧化锌纳米颗粒(NanoZnO)处理的G2/M阻滞。关于机制,PRKCSH缺乏可诱导STAT6易位到细胞核,通过与p53启动子区结合从-365bp到+126bp来激活p53表达。最终,激活的p53有助于纳米ZnO诱导的肺癌细胞G2/M阻滞。一起来看,我们的数据为PRKCSH的免疫治疗靶点选择和预后价值提供了新的见解.由于G2/M细胞周期检查点对肺癌预后至关重要,靶向PRKCSH表达以抑制STAT6/p53通路的激活是治疗肺癌的潜在治疗策略.
    PRKCSH, also known as glucosidase II beta, functions as a contributor to lung tumorigenesis by regulating the cell cycle in a p53-dependent manner under severe environmental stress. However, the prognostic value and molecular mechanisms by which the level of PRKCSH is significantly increased in cancer cells are not clearly understood. Here, we first generated a biological profile of PRKCSH expression changes in cancers by analysing bioinformatic data from cancer databases. We found that higher PRKCSH expression was correlated with a poorer prognosis and greater infiltration of most immune cell types in patients with lung cancer. In particular, PRKCSH expression showed significant negative correlations with the level of STAT6 (r = -0.31, p < 0.001) in lung cancer tissues. We further found that PRKCSH deficiency promoted G2/M arrest in response to zinc oxide nanoparticle (Nano ZnO) treatment in A549 cells. With regard to the mechanism, PRKCSH deficiency may induce STAT6 translocation to the nucleus to activate p53 expression through binding to the p53 promoter region from -365 bp to +126 bp. Eventually, activated p53 contributed to Nano-ZnO-induced G2/M arrest in lung cancer cells. Taken together, our data provide new insights into immunotherapy target choices and the prognostic value of PRKCSH. Since the G2/M cell cycle checkpoint is crucial for lung cancer prognosis, targeting PRKCSH expression to suppress the activation of the STAT6/p53 pathway is a potential therapeutic strategy for managing lung cancer.
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  • 文章类型: Journal Article
    通过光催化氧化工艺从废水中去除药物被认为是一种有吸引力的方法和环境友好的解决方案。本报告旨在评估Ag/g-C3N4/ZnO纳米棒在制药行业废水处理中的实际应用潜力。催化剂是通过直接和环境友好的策略合成的。具体来说,通过简单的自组装方法构建了g-C3N4/ZnO纳米棒异质结构,然后通过光还原途径将Ag纳米颗粒修饰在g-C3N4/ZnO纳米棒上。结果表明,三种商业药物(扑热息痛,阿莫西林,在小剂量Ag/g-C3N4/ZnO纳米棒(0.08gL-1)的存在下,高浓度(40mgL-1)的头孢氨苄)被显着降解。Ag/g-C3N4/ZnO纳米棒光催化剂对扑热息痛的降解性能比原始g-C3N4、ZnO纳米棒高3.8、1.8、1.3倍,和g-C3N4/ZnO纳米棒。此外,Ag/g-C3N4/ZnO纳米棒具有出色的可重用性和化学稳定性,可实现78%的对乙酰氨基酚降解效率,并在五个循环后保持光催化剂的化学结构。此外,本研究还讨论了光催化机理的解释和光催化药物降解能力的比较。
    Pharmaceutical drugs\' removal from wastewater by photocatalytic oxidation process is considered as an attractive approach and environmentally friendly solution. This report aims to appraise the practical application potential of Ag/g-C3N4/ZnO nanorods toward the wastewater treatment of the pharmaceutical industry. The catalysts are synthesized by straightforward and environmentally-friendly strategies. Specifically, g-C3N4/ZnO nanorods heterostructure is constructed by a simple self-assembly method, and then Ag nanoparticles are decorated on g-C3N4/ZnO nanorods by a photoreduction route. The results show that three commercial drugs (paracetamol, amoxicillin, and cefalexin) with high concentration (40 mg L-1) are significantly degraded in the existence of a small dosage of Ag/g-C3N4/ZnO nanorods (0.08 g L-1). The Ag/g-C3N4/ZnO nanorods photocatalyst exhibits degradation performance of paracetamol higher 3.8, 1.8, 1.3 times than pristine g-C3N4, ZnO nanorods, and g-C3N4/ZnO nanorods. Furthermore, Ag/g-C3N4/ZnO nanorods have an excellent reusability and a chemical stability that achieved paracetamol degradation efficiency of 78% and remained chemical structure of the photocatalyst after five cycles. In addition, the photocatalytic mechanism explanation and comparison of photocatalytic drugs\' degradation ability have also been discussed in this study.
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  • 文章类型: Case Reports
    BACKGROUND: Varicella zoster virus (VZV) causes varicella primarily in childhood, and some rare adults also report varicella. Herpes zoster mainly occurs in adults by endogenous reactivation of latent VZV. Until now, varicella and herpes zoster have seldom been reported simultaneously in one patient. Here, we report a rare case co-presenting with varicella and herpes zoster in a Chinese adult.
    METHODS: A 44-year-old Chinese man suffered papules and vesicles with pain on the left ear. Five days after onset, he was admitted to the Department of Dermatology of The Third Hospital of Xiamen. Physical examination revealed that small vesicles surrounded by erythema had developed on his trunk, back and neck, and unilateral papules and vesicles in ribbons had also developed on the left ear. This patient was excluded from human immunodeficiency virus and Treponema pallidum infections by ELISA antibody tests. Laboratory tests revealed that the ratio of eosinophils (0.1%) and eosinophil count (0.0 × 109/L) were significantly downregulated. Treatment with valacyclovir, ebastine, mecobalamine, pregabalin and calamine lotion for 5 days was effective therapy for varicella and herpes zoster. Polymerase chain reaction for vesicular fluids from varicella and herpes zoster was positive for VZV, and further phylogenetic analysis and single nucleotide polymorphism variations confirmed that the VZV genotype was type J (clade 2).
    CONCLUSIONS: This rare case highlights awareness of varicella and herpes zoster caused by VZV infection in adults. Our report provides novel insight into the rare clinical presentation of VZV genotype J.
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  • 文章类型: Journal Article
    Understanding nanomaterial (NM)-protein interactions is a key issue in defining the bioreactivity of NMs with great impact for nanosafety. In the present work, the complex phenomena occurring at the bio/nano interface were evaluated in a simple case study focusing on NM-protein binding thermodynamics and protein stability for three representative metal oxide NMs, namely, zinc oxide (ZnO; NM-110), titanium dioxide (TiO2; NM-101), and silica (SiO2; NM-203). The thermodynamic signature associated with the NM interaction with an abundant protein occurring in most cell culture media, bovine serum albumin (BSA), has been investigated by isothermal titration and differential scanning calorimetry. Circular dichroism spectroscopy offers additional information concerning adsorption-induced protein conformational changes. The BSA adsorption onto NMs is enthalpy-controlled, with the enthalpic character (favorable interaction) decreasing as follows: ZnO (NM-110) > SiO2 (NM-203) > TiO2 (NM-101). The binding of BSA is spontaneous, as revealed by the negative free energy, ΔG, for all systems. The structural stability of the protein decreased as follows: TiO2 (NM-101) > SiO2 (NM-203) > ZnO (NM-110). As protein binding may alter NM reactivity and thus the toxicity, we furthermore assessed its putative influence on DNA damage, as well as on the expression of target genes for cell death (RIPK1, FAS) and oxidative stress (SOD1, SOD2, CAT, GSTK1) in the A549 human alveolar basal epithelial cell line. The enthalpic component of the BSA-NM interaction, corroborated with BSA structural stability, matched the ranking for the biological alterations, i.e., DNA strand breaks, oxidized DNA lesions, cell-death, and antioxidant gene expression in A549 cells. The relative and total content of BSA in the protein corona was determined using mass-spectrometry-based proteomics. For the present case study, the thermodynamic parameters at bio/nano interface emerge as key descriptors for the dominant contributions determining the adsorption processes and NMs toxicological effect.
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  • 文章类型: Journal Article
    OBJECTIVE: Children are at high risk of injuries and wounds. The application of medical grade honey is a promising approach to improving the healing of wounds of various origin and severity. However, the use of medical grade honey in young paediatric patients remains limited. The aim of this study is to show the safety, efficacy and usefulness of medical grade honey in abdominal wounds, of different causes, in paediatric patients.
    METHODS: This was a prospective, observational case series evaluating five young infants with abdominal wounds at the General Hospital in Thessaloniki. All wounds were treated in the same manner with daily medical grade honey applied to the wound area and closely monitored.
    RESULTS: All treated wounds rapidly presented granulation tissue formation and underwent re-epithelialisation. Peripheral oedema and inflammation decreased upon initial application. Necrotic tissue was effectively debrided when present. Slough was removed and no signs of infection were detected, irrespective of initial wound presentations. Scar formation was minimal and the full range of motion was preserved in all cases.
    CONCLUSIONS: Based on this case study, medical grade honey is safe and effective in treating different abdominal wounds, including infected or dehisced wounds as well as burns. The easy application and broad applicability make medical grade honey recommendable as a first-line treatment in paediatric patients.
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  • 文章类型: Comparative Study
    在欧洲,REACH框架指令规定在化学品商业化之前采集有关水生物种毒性的数据,以评估环境风险。根据官方方法,暴露测试在体外和标准化条件下进行:OECD的指南规则外部变量,如水类型,喂养条件,和曝光时间。因此,这样获得的结果可能与自然环境中观察到的效果不同。本研究收集了暴露于纳米金属氧化物(ZnO,TiO2)在标准OECD条件下通过暴露获得的D.magna上,将它们与在更相似的条件下暴露于自然环境(即混合物,feeding).高剂量暴露决定了气泡疾病。暴露于LC10的动物在禁食和进食条件下都会主动摄取纳米颗粒。此外,记录了在混合物中比在单一分散体中更厚的纳米颗粒涂层的身体埋葬。此外,结果表明:(i)效果随时间增加;(ii)在两种单一分散中,n-ZnO的效果均低于n-TiO2,和混合物;(iii)表面活性剂的存在增加了纳米颗粒的毒性;(iv)固定化是比死亡率更敏感的终点;(v)喂食增加了测试敏感性,改善了治疗和对照之间的差异,直到96小时,并且允许比标准OECD测试更长的暴露时间。作为一般性评论,本研究提供的证据表明,在标准化OECD条件下获得的体外生态毒理学结果可能与动物在自然(摄食和混合)暴露条件下的反应显著不同.
    In Europe REACH framework directive imposes data acquisition concerning toxicity on acquatic species before the commercialization of chemicals to assess environmental risks. According to official methods, exposure tests are performed under in vitro and standardized conditions: OECD\'s guideline rules external variables such as water type, feeding conditions, and exposure time. As consequence, such obtained results could be different from effects observed in natural environments. This study collects effects within 24-96 h of exposure to nano metal-oxides (ZnO, TiO2) on D. magna obtained by the exposure under standard OECD conditions comparing them with results obtained by the exposure under more similar conditions to natural environment (i.e. mixture, feeding). High doses exposure determines gas-bubble disease. Animals exposed to LC10 actively ingest nanoparticles under both fasting and feeding conditions. Furthermore, body burial by a coat of nanoparticles thicker in mixtures than in single dispersions was recorded. Furthermore, results show that: (i) effects increase over time; (ii) n-ZnO results less effective than n-TiO2 in both single dispersion, and mixture; (iii) the presence of surfactant increases toxicity of nanoparticles; (iv) immobilization is a more sensitive endpoint than mortality; (v) feeding increases test sensitiveness improving differences among treated and controls till 96 h and allowing longer exposure times than standard OECD test. As general remark, this study provides evidence that in vitro ecotoxicological results obtained under standardized OECD conditions could be significant different to animals\' responses under natural (feeding and mixtures) exposure conditions.
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  • 文章类型: Journal Article
    尽管使用组合方法合成多组分金属氧化物系统的库很普遍,组合方法在研究简单的金属氧化物时很少实现,特别适用于原子层沉积(ALD)技术。在这些文献中,在ALD生长的简单金属氧化物中使用了一种新颖的组合方法技术来合成“空间可寻址组合库”。在ALD过程中定义了梯度中的两个关键因素:(1)过程温度和(2)交叉流反应器内脉冲气体的不均匀流动。为了验证我们新颖的组合方法的可行性,以氧化锌(ZnO)为例,一种简单的金属氧化物,其性质众所周知,执行。由于诱导梯度,发现ZnO(002)微晶尺寸在100mm晶片(〜10-20nm)上逐渐变化,归一化拉曼E2/A1峰强度比相应增加。研究结果与扫描电子显微镜观察到的可见晶粒尺寸非常吻合。新颖的组合方法提供了一种对两种梯度的组合效果进行系统解释的方法,特别是在分析ZnO晶体的微观结构方面。此外,组合库揭示了过程温度,而不是晶体大小,在测定ZnO的电导率中起着最重要的作用。
    Though the synthesis of libraries of multicomponent metal oxide systems is prevalent using the combinatorial approach, the combinatorial approach has been rarely realized in studying simple metal oxides, especially applied to the atomic layer deposition (ALD) technique. In this literature, a novel combinatorial approach technique is utilized within an ALD grown simple metal oxide to synthesize a \"spatially addressable combinatorial library\". The two key factors in gradients were defined during the ALD process: (1) the process temperature and (2) a nonuniform flow of pulsed gases inside a cross-flow reactor. To validate the feasibility of our novel combinatorial approach, a case study of zinc oxide (ZnO), a simple metal oxide whose properties are well-known, is performed. Because of the induced gradient, the ZnO (002) crystallite size was found to gradually vary across a 100 mm wafer (∼10-20 nm) with a corresponding increase in the normalized Raman E2/A1 peak intensity ratio. The findings agree well with the visible grain size observed from scanning electron microscope. The novel combinatorial approach provides a means of systematical interpretation of the combined effect of the two gradients, especially in the analysis of the microstructure of ZnO crystals. Moreover, the combinatorial library reveals that the process temperature, rather than the crystal size, plays the most significant role in determining the electrical conductivity of ZnO.
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  • 文章类型: Journal Article
    The unique anticancer, biochemical, and immunologic properties of nanomaterials are becoming a new tool in biomedical research. Their translation into the clinic promises a new wave of targeted therapies. One nanomaterial of particular interest are zinc oxide (ZnO) nanoparticles (NPs), which has distinct mechanisms of anticancer activity including unique surface, induction of reactive oxygen species, lipid oxidation, pH, and also ionic gradients within cancer cells and the tumor microenvironment. It is recognized that ZnO NPs can serve as a direct enzyme inhibitor. Significantly, ZnO NPs inhibit extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) associated with melanoma progression, drug resistance, and metastasis. Indeed, direct intratumoral injection of ZnO NPs or a complex of ZnO with RNA significantly suppresses ERK and AKT phosphorylation. These data suggest ZnO NPs and their complexes or conjugates with nucleic acid therapeutic or anticancer protein may represent a potential new strategy for the treatment of metastatic melanoma, and potentially other cancers. This review focuses on the anticancer mechanisms of ZnO NPs and what is currently known about its biochemical effects on melanoma, biologic activity, and pharmacokinetics in rodents and its potential for translation into large animal, spontaneously developing models of melanoma and other cancers, which represent models of comparative oncology.
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