The crystal facet-dependent electrochemical performance of TiO2 nanocrystals for heavy metal detection: Theoretical prediction and experimental proof

Tailored design/fabrication of electroanalytical materials with highly-active exposed crystal planes is of great importance for the development of electrochemical sensing. In this work, combining experimental and theoretical efforts, we reported a facile strategy to fabricate TiO2 nanocrystals with tunable electrochemical performance for heavy metal detection. Density functional theory (DFT) calculations indicated that TiO2 (001) facet showed relative larger adsorption energy and lower diffusion energy barrier toward heavy metal ions, which is favorable for obtaining better electrochemical stripping behaviors. Based on this prediction, a series of TiO2 nanocrystals with different ratios of exposed (001) and (101) facets were synthesized. Electrochemical stripping experiments further demonstrated that with the increase of the percentage of exposed (001) facet, the sensitivity toward Pb(II) and Cd(II) was increased accordingly. When the percentage of exposed (001) facet was increased from 7% to 80%, the sensitivity increased by 190% and 93% for Pb(II) and Cd(II), respectively. Our work provides an effective route to construct advanced electroanalytical materials for sensing

Effects of Surface Modification of Nanotube Arrays on the Performance of CdS Quantum-Dot-Sensitized Solar Cells

CdS-sensitized TiO2 nanotube arrays have been fabricated using the method of successive ionic layer adsorption and reaction and used as a photoanode for quantum-dot-sensitized solar cells. Before being coated with CdS, the surface of TiO2 nanotube arrays was treated with TiCl4, nitric acid (HNO3), potassium hydroxide (KOH), and methyltrimethoxysilane (MTMS), respectively, for the purpose of reducing the interface transfer resistance of quantum-dot-sensitized solar cells. The surfaces of the modified samples represented the characteristics of superhydrophilic and hydrophobic which directly affect the power conversion efficiency of the solar cells. The results showed that surface modification resulted in the reduction of the surface tension, which played a significant role in the connectivity of CdS and TiO2 nanotube arrays. In addition, the solar cells based on CdS/TiO2 electrode treated by HNO3 achieved a maximum power conversion efficiency of 0.17%, which was 42% higher than the reference sample without any modification

Synthesis and Characterization of Hierarchical Structured TiO 2

Hierarchical structured TiO2 nanotubes were prepared by mechanical ball milling of highly ordered TiO2 nanotube arrays grown by electrochemical anodization of titanium foil. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, specific surface area analysis, UV-visible absorption spectroscopy, photocurrent measurement, photoluminescence spectra, electrochemical impedance spectra, and photocatalytic degradation test were applied to characterize the nanocomposites. Surface area increased as the milling time extended. After 5 h ball milling, TiO2 hierarchical nanotubes exhibited a corn-like shape and exhibited enhanced photoelectrochemical activity in comparison to commercial P25. The superior photocatalytic activity is suggested to be due to the combined advantages of high surface area of nanoparticles and rapid electron transfer as well as collection of the nanotubes in the hierarchical structure. The hierarchical structured TiO2 nanotubes could be applied into flexible applications on solar cells, sensors, and other photoelectrochemical devices

Preparation and optimization of poly (lactic-co-glycolic acid) rod-shaped particles in nano size range for paclitaxel delivery

Nanoparticle shape has been acknowledged as an important design parameter due to its influence on nanoparticle interaction with biological systems. However, there is lacking of simple and scalable preparation technique for drug loaded non-spherical polymeric nanoparticles for a long time, thus hindering the potential applications. Although our previous research has modified the traditional emulsion solvent evaporation technique by adding guest molecules to prepare non-spherical poly (lactic-co-glycolic acid) (PLGA) particles, it is difficult to obtain nano-sized rods with minor axis less than 200 nm, which may have great potential in cancer therapy. Herein, in present research, the two-step ESE method was used and optimized to prepare poly (lactic-co-glycolic acid) nanorods for paclitaxel delivery. Firstly, the single-factor experiment was used to screen the influence of multi-factors including type of guest molecules, concentration of guest molecules, emulsification method, surfactant concentration, oil volume, poly (lactic-co-glycolic acid) concentration on the size and shape to determine the range of variables; based on the above range, a multi-factor and multi-level orthogonal experiment was designed. The formula is evaluated by the rod fabrication yield and the aspect ratio of major axis to minor axis. The results showed that the yield of nanorods in the optimal formula was 99% and the aspect ratio was 5.35 ± 2.05 with the minor axis of 135.49 ± 72.66 nm, and major axis of 657.77 ± 307.63 nm. In addition, the anti-cancer drug paclitaxel was successfully encapsulated in PLGA nanorods by the same technique. Our results not only enrich the ESE technique for preparing small sized poly (lactic-co-glycolic acid) nanorods, but also envision the potential application of nanorods for targeted cancer therapy with the delivery of paclitaxel

Inferring the diagnostic potential of 18F-FDG-PET/CT in post-renal transplantation from a unique case harboring multiple rare complications

Renal transplantation is undoubtedly an effective treatment for patients with end-stage renal disease, but it is certainly not a cure. Patients require lifelong immunosuppression to maintain optimal allograft function, and post-operative risk complications such as cancer in the transplant recipient cannot be ignored. Besides, infection is a silent complication that follows transplantation. Relatedly, herein, we present a report of a 40-year-old patient who underwent renal transplantation and promptly developed a diffuse large B-cell tumor in the liver and Aspergillus infection in the trachea. In addition, an inflammatory necrotizing granuloma was also observed in the muscles. Of importance, we also described the potential of 18F-FDG-PET/CT, which was instrumental in monitoring and evaluating these relevant post-operative complications in this rare case

Identification of LncRNA Linc00513 Containing Lupus-Associated Genetic Variants as a Novel Regulator of Interferon Signaling Pathway

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by augmented type I interferon signaling. High-throughput technologies have identified plenty of SLE susceptibility single-nucleotide polymorphisms (SNPs) yet the exact roles of most of them are still unknown. Functional studies are principally focused on SNPs in the coding regions, with limited attention paid to the SNPs in non-coding regions. Long non-coding RNAs (lncRNAs) are important players in shaping the immune response and show relationship to autoimmune diseases. In order to reveal the role of SNPs located near SLE related lncRNAs, we performed a transcriptome profiling of SLE patients and identified linc00513 as a significantly over expressed lncRNA containing functional SLE susceptibility loci in the promoter region. The risk-associated G allele of rs205764 and A allele of rs547311 enhanced linc00513 promoter activity and related to increased expression of linc00513 in SLE. We also identified linc00513 to be a novel positive regulator of type I interferon pathway by promoting the phosphorylation of STAT1 and STAT2. Elevated linc00513 expression positively correlated with IFN score in SLE patients. Linc00513 expression was higher in active disease patients than those inactive ones. In conclusion, our data identify two functional promoter variants of linc00513 that contribute to increased level of linc00513 and confer susceptibility on SLE. The study provides new insights into the genetics of SLE and extends the role of lncRNAs in the pathogenesis of SLE

Differential roles of nitric oxide synthase isozymes in cardiotoxicity and mortality following chronic doxorubicin treatment in mice

The roles of individual nitric oxide synthases (NOS) in anthracycline-related cardiotoxicity are not completely understood. We investigated the effects of a chronic treatment with doxorubicin (DOX) on knockouts of the individual NOS isozymes and on transgenic mice with myocardial overexpression of eNOS. Fractional shortening (FS) was reduced in untreated homozygous nNOS and iNOS knockouts as well as in eNOS transgenics. DOX-induced FS decrease in wild-type mice was attenuated only in eNOS knockouts, which were found to overexpress nNOS. No worsening of contractility was observed in DOX-treated eNOS transgenics and iNOS knockouts. Although the surviving DOX-treated nNOS knockouts exhibited no further impairment in contractility, most (70%) animals died within 7 weeks after treatment onset. In comparison to untreated wild-type hearts, the nitric oxide (NO) level was lower in hearts from DOX-treated wild-type mice and in all three untreated knockouts. DOX treatment had no effect on NO in the knockouts. These data indicate differential roles of the individual NOS in DOX-induced cardiotoxicity. Protection against DOX effects conferred by eNOS deletion may be mediated by a compensatory overexpression of nNOS. NOS inhibition-based prevention of anthracycline-induced cardiotoxicity should be eNOS-selective, simultaneously avoiding inhibiting nNOS

Reversed-engineered human alveolar lung-on-a-chip model

Here, we present a physiologically relevant model of the human pulmonary alveoli. This alveolar lung-on-a-chip platform is composed of a three-dimensional porous hydrogel made of gelatin methacryloyl with an inverse opal structure, bonded to a compartmentalized polydimethylsiloxane chip. The inverse opal hydrogel structure features well-defined, interconnected pores with high similarity to human alveolar sacs. By populating the sacs with primary human alveolar epithelial cells, functional epithelial monolayers are readily formed. Cyclic strain is integrated into the device to allow biomimetic breathing events of the alveolar lung, which, in addition, makes it possible to investigate pathological effects such as those incurred by cigarette smoking and severe acute respiratory syndrome coronavirus 2 pseudoviral infection. Our study demonstrates a unique method for reconstitution of the functional human pulmonary alveoli in vitro, which is anticipated to pave the way for investigating relevant physiological and pathological events in the human distal lung