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https://www.readbyqxmd.com/read/28650036/towards-the-liquid-phase-exfoliation-of-bismuth-iodide
#1
N Heidary, A Beyer, K Volz, J Heine
Liquid phase exfoliation (LPE) of layered compounds towards few- or monolayers has been established as one of the prime methods in the growing field of 2D material research. Here, we present first steps towards an effective LPE of bismuth(iii) iodide, a semiconductor with potential as a photovoltaic absorber material. We highlight guidelines in the choice of exfoliating solvent, which differ significantly from those used with transition metal dichalcogenides or graphene. We also present first evidence of successful few-layer formation from spectroscopic, electron microscopy and electron diffraction investigations...
June 26, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28649865/dental-stem-cells-recent-progresses-in-tissue-engineering-and-regenerative-medicine
#2
João Botelho, Maria Alzira Cavacas, Vanessa Machado, José João Mendes
Since the disclosure of adult mesenchymal stem cells (MSCs) there have been an intense investigation on the characteristics of these cells and their potentialities. Dental Stem Cells (DSCs) are MSC-like populations with self-renewal capacity and multidifferentiation potential. Currently, there are five main DSCs, dental pulp stem cells (DPSCs), stem cells from exfoliated deciduous teeth (SHED), stem cells from apical papilla (SCAP), periodontal ligament stem cells (PDLSCs), and Dental Follicle Precursor Cells (DFPCs)...
June 24, 2017: Annals of Medicine
https://www.readbyqxmd.com/read/28649798/electrochemical-exfoliation-of-layered-black-phosphorous-to-phosphorene
#3
Martin Pumera
Among 2D materials that recently have attracted enormous interest, black phosphorous (BP) is gaining a rising popularity due to its tunable band gap structure strongly correlated to the thickness and which can enable its use in optoelectronic and electronic applications. It is therefore important to provide a facile and scalable methodology to prepare single or few-layer BP nanosheets. We propose here a simple and fast top-down method to exfoliate a BP crystal into nanosheets of reduced thickness using electrochemistry...
June 26, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28644607/electrochemical-exfoliation-of-graphite-in-aqueous-sodium-halide-electrolytes-towards-low-oxygen-content-graphene-for-energy-and-environmental-applications
#4
Jose Maria Munuera, Juan Ignacio Paredes, Marina Enterria, Ana Pagán, Silvia Villar-Rodil, Manuel Fernando R Pereira, J I Martins, José L Figueiredo, Jose Luis Cenis, Amelia Martinez-Alonso, Juan Manuel D Tascon
Graphene and graphene-based materials have shown great promise in many technological applications, but their large-scale production and processing by simple and cost-effective means still constitute significant issues in the path of their widespread implementation. Here, we investigate a straightforward method for the preparation of a ready-to-use and low oxygen content graphene material that is based on electrochemical (anodic) delamination of graphite in aqueous medium with sodium halides as the electrolyte...
June 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28643788/terahertz-saturable-absorbers-from-liquid-phase-exfoliation-of-graphite
#5
Vezio Bianchi, Tian Carey, Leonardo Viti, Lianhe Li, Edmund H Linfield, A Giles Davies, Alessandro Tredicucci, Duhee Yoon, Panagiotis G Karagiannidis, Lucia Lombardi, Flavia Tomarchio, Andrea C Ferrari, Felice Torrisi, Miriam S Vitiello
Saturable absorbers (SA) operating at terahertz (THz) frequencies can open new frontiers in the development of passively mode-locked THz micro-sources. Here we report the fabrication of THz SAs by transfer coating and inkjet printing single and few-layer graphene films prepared by liquid phase exfoliation of graphite. Open-aperture z-scan measurements with a 3.5 THz quantum cascade laser show a transparency modulation ∼80%, almost one order of magnitude larger than that reported to date at THz frequencies...
June 15, 2017: Nature Communications
https://www.readbyqxmd.com/read/28642943/aqueous-dispersions-of-nanostructures-formed-through-the-self-assembly-of-iminolipids-with-exchangeable-hydrophobic-termini
#6
Wen Li, Daryl McManus, Han Liu, Cinzia Casiraghi, Simon J Webb
The addition of amines to an aldehyde surfactant, which was designed to be analogous to didodecyldimethylammonium bromide, gave exchangeable "iminolipids" that self-assembled to give stable aqueous dispersions of nano-sized vesicles. For example, sonication of suspensions of the n-hexylamine-derived iminolipid gave vesicles 50 to 200 nm in diameter that could encapsulate a water-soluble dye. The iminolipids could undergo dynamic exchange with added amines, and the resulting equilibrium constants (Krel) were quantified by (1)H NMR spectroscopy...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28640986/antimonene-quantum-dots-synthesis-and-application-as-near-infrared-photothermal-agents-for-effective-cancer-therapy
#7
Wei Tao, Xiaoyuan Ji, Xiaoding Xu, Mohammad Ariful Islam, Zhongjun Li, Si Chen, Phei Er Saw, Han Zhang, Zameer Bharwani, Zilei Guo, Jinjun Shi, Omid Farokhzad
Photothermal therapy (PTT) has shown significant potential for cancer therapy. However, developing nanomaterials (NMs)-based photothermal agents (PTAs) with satisfactory photothermal conversion efficacy (PTCE) and biocompatibility remains a key challenge. Herein, a new generation of PTAs based on two-dimensional (2D) antimonene quantum dots (AMQDs) was developed by a novel liquid exfoliation method. Surface modification of AMQDs with polyethylene glycol (PEG) significantly enhanced both biocompatibility and stability in physiological medium...
June 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28640388/electrostatic-driven-exfoliation-and-hybridization-of-2d-nanomaterials
#8
Guijian Guan, Jing Xia, Shuhua Liu, Yuan Cheng, Shiqiang Bai, Si Yin Tee, Yong-Wei Zhang, Ming-Yong Han
Here, direct and effective electrostatic-driven exfoliation of tungsten trioxide (WO3 ) powder into atomically thin WO3 nanosheets is demonstrated for the first time. Experimental evidence together with theoretical simulations clearly reveal that the strong binding of bovine serum albumin (BSA) on the surface of WO3 via the protonation of NH2 groups in acidic conditions leads to the effective exfoliation of WO3 nanosheets under sonication. The exfoliated WO3 nanosheets have a greatly improved dispersity and stability due to surface-protective function of BSA, and exhibit a better performance and unique advantages in applications such as visible-light-driven photocatalysis, high-capacity adsorption, and fast electrochromics...
June 22, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28640134/association-between-pd-l1-and-hpv-status-and-the-prognostic-value-for-hpv-treatment-in-premalignant-cervical-lesion-patients
#9
Feng Yang-Chun, Cheng Zhen-Zhen, Huang Yan-Chun, Ma Xiu-Min
The difference of PD-L1 expression between only HPV-positive patients and premalignant cervical lesion patients did not be reported in present studies. And to test the PD-L1 expression in some cervical cell lesion studies using cervical exfoliated cells sample also was ignored. Meanwhile, the PD-L1 expression as a predictive biomarker still existed controversy. So in the study, first to compare the expression of PD-L1 between only HPV-positive patients and premalignant cervical lesion patients, then to research the association between PD-L1 and HPV status, lastly to explore the possible prognostic value for HPV treatment in premalignant cervical lesion patients...
June 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28639729/two-dimensional-metal-organic-framework-nanosheets-for-membrane-based-gas-separation
#10
Weishen Yang, Yuan Peng, Yanshuo Li, Yujie Ban
Metal-organic framework (MOF) nanosheets could serve as ideal building blocks of molecular sieve membranes due to their structural diversity and minimized-mass transfer barrier. Till now, discovery of appropriate MOF nanosheets and facile fabrication of high performance MOF nanosheet-based membranes remain as great challenges. Herein, we present a modified soft-physical exfoliation methodology to disintegrate lamellar amphiprotic MOF into nanosheets with high aspect-ratio. Consequently sub-10 nm-thick ultrathin membranes were successfully prepared and demonstrated a remarkable H2/CO2 separation performance with separation factor up to 166 and H2 permeance up to 8 ×10E-7 mol/m2∙s∙Pa at elevated testing temperature due to a well-defined size exclusion effect...
June 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28638906/controlled-defect-creation-and-removal-in-graphene-and-mos2-monolayers
#11
D W Li, Q M Zou, X Huang, H Rabiee Golgir, K Keramatnejad, J F Song, Z Y Xiao, L S Fan, X Hong, L Jiang, J F Silvain, S Sun, Y F Lu
It is known that defects strongly influence the properties of two-dimensional (2D) materials. The controlled creation and removal of defects can be utilized to tailor the optical and electronic responses of these 2D materials for optoelectronic and nanoelectronic applications. In this study, we developed an efficient approach to reversibly control the defect states in mechanically exfoliated graphene and molybdenum disulfide (MoS2) monolayers. The defects were created by aluminium oxide (Al2O3) plasmas and removed by moderate thermal annealing at up to 300 °C...
June 22, 2017: Nanoscale
https://www.readbyqxmd.com/read/28636235/stem-cell-based-tooth-and-periodontal-regeneration
#12
Lei Hu, Yi Liu, Songlin Wang
Currently regeneration of tooth and periodontal damage still remains great challenge. Stem cell-based tissue engineering raised novel therapeutic strategies for tooth and periodontal repair. Stem cells for tooth and periodontal regeneration include dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), stem cells from the dental apical papilla (SCAPs), and stem cells from human exfoliated deciduous teeth (SHEDs), dental follicle stem cells (DFSCs), dental epithelial stem cells (DESCs), bone marrow mesenchymal stem cells (BMMSCs), adipose-derived stem cells (ADSCs), embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)...
June 21, 2017: Oral Diseases
https://www.readbyqxmd.com/read/28635642/lack-of-association-between-serum-vitamin-b%C3%A2-vitamin-b12-and-vitamin-d-levels-with-different-types-of-glaucoma-a-systematic-review-and-meta-analysis
#13
Shengjie Li, Danhui Li, Mingxi Shao, Wenjun Cao, Xinghuai Sun
Although vitamins play a major role in health, and their deficiency may be linked to symptoms of optic-nerve dysfunction, the association between serum vitamin levels and glaucoma in humans remains controversial. In this study, articles in the PubMed, Web of Science, and EMBASE databases were searched up to 25March 2017. Nine studies on primary open-angle glaucoma (POAG), four studies on normal tension glaucoma (NTG), and six studies on exfoliative glaucoma (EXG) were retrieved. The combined results showed no differences in the levels of serum vitamin B₆ between POAG (p = 0...
June 21, 2017: Nutrients
https://www.readbyqxmd.com/read/28634339/effective-synthesis-of-highly-oxidized-graphene-oxide-that-enables-wafer-scale-nanopatterning-preformed-acidic-oxidizing-medium-approach
#14
Chun-Hu Chen, Shin Hu, Jyun-Fu Shih, Chang-Ying Yang, Yun-Wen Luo, Ren-Huai Jhang, Chao-Ming Chiang, Yung-Jr Hung
Demand for rapid and massive-scale exfoliation of bulky graphite remains high in graphene commercialization and property manipulation. We report a procedure utilizing "preformed acidic oxidizing medium (PAOM)" as a modified version of the Hummers' method for fast and reliable synthesis of graphene oxide. Pre-mixing of KMnO4 and concentrated H2SO4 prior to the addition of graphite flakes enables the formation of effectively and efficiently oxidized graphene oxide (EEGO) featured by its high yields and suspension homogeneity...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28629074/tunable-green-graphene-silk-biomaterials-mechanism-of-protein-based-nanocomposites
#15
Fang Wang, S S Jyothirmayee Aravind, Hao Wu, Joseph Forys, Venkat Venkataraman, Kandalam Ramanujachary, Xiao Hu
Green graphene materials prepared by photoreduction of graphite oxide were first time blended with aqueous-based silk fibroin proteins to improve the mechanical and thermal properties of silk biomaterials, and their nanocomposite interaction mechanism was illustrated. Powder X-ray diffraction (XRD) analysis confirmed the complete exfoliation of graphite oxide to graphene in presence of focused pulses of solar radiation. By varying the concentration of graphene (0.1wt% to 10wt%), a series of free standing graphene-silk films were prepared and were systematically characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and nanoindentation measurements...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629017/design-of-a-new-nanocomposite-between-bismuth-nanoparticles-and-graphene-oxide-for-development-of-electrochemical-sensors
#16
Eduardo H Bindewald, Arthur F Schibelbain, Maurício A P Papi, Eduardo G C Neiva, Aldo J G Zarbin, Márcio F Bergamini, Luiz H Marcolino-Júnior
This study describes a new route for preparation of a nanocomposite between graphene oxide (GO) and bismuth nanoparticles (BiNPs) and its evaluation as modifier electrode for development of electrochemical sensors. BiNPs were synthesized under ultrasound conditions using Bi(NO3)3 as metal precursor and ascorbic acid (AA) as reducing agent/passivating. Some experimental parameters of BiNPs synthesis such as Bi(3+):AA molar ratio and reaction time were conducted aiming the best voltammetric performance of the sensor...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28628293/one-step-device-fabrication-of-phosphorene-and-graphene-interdigital-micro-supercapacitors-with-high-energy-density
#17
Han Xiao, Zhong-Shuai Wu, Long Chen, Feng Zhou, Shuanghao Zheng, Wencai Ren, Hui-Ming Cheng, Xinhe Bao
Rational engineering and simplified fabrication of high-energy micro-supercapacitors (MSCs) using graphene and other 2D nanosheets are of great value for flexible and integrated electronics. Here we develop one-step mask-assisted simplified fabrication of high-energy MSCs (PG-MSCs) based on the interdigital hybrid electrode (PG) patterns of stacking high-quality phosphorene nanosheets and electrochemically exfoliated graphene in ionic liquid electrolyte. The hybrid PG films with interdigital patterns were directly manufactured by layer-by-layer deposition of phosphorene and graphene nanosheets with the assistance of a customized interdigital mask, and directly transferred onto a flexible substrate...
June 22, 2017: ACS Nano
https://www.readbyqxmd.com/read/28627893/green-and-facile-esterification-procedure-leading-to-crystalline-functionalized-graphite-oxide
#18
Maria Rosaria Acocella, Luciana D'Urso, Mario Maggio, Roberto Avolio, Maria Emanuela Errico, Gaetano Guerra
A simple and eco-friendly procedure of esterification of graphite oxide (GO), which uses acetic anhydride as model reagent and ethyl acetate as green solvent, is reported. The procedure leads to high functionalization degrees (at least up to 4.5 mol% of acetyl groups, referred to graphitic C atoms) and it is much more effective than the literature one based on pure acetic anhydride. Surprisingly, our acetylation procedure does not destroy or reduce GO crystallinity but, irrespective of a substantial increase of distance between GO layers (from 0...
June 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28627552/graphite-exfoliation-in-cellulose-solutions
#19
E S Ferreira, D S da Silva, T A L Burgo, B C Batista, F Galembeck
Shaking graphite powder dispersed in an aqueous alkaline cellulose solution produces stable dispersions of hydrophilic, thin graphite sheets with lateral dimensions reaching many micrometers. The X-ray diffractogram and Raman spectrum of the exfoliated graphite differ from the well-known graphite patterns. Analytical transmission electron micrographs show cellulose bound to the surface of thin lamellae and this is confirmed by scanning probe micrographs. The dispersant properties of dissolved cellulose are assigned to its adsorption on graphite by juxtaposition of the hydrophobic planes on both substances, forming hydrophilic particles...
June 19, 2017: Nanoscale
https://www.readbyqxmd.com/read/28624454/ameloblast-like-characteristics-of-human-hertwig-s-epithelial-rest-of-malassez-epithelial-rest-of-malassez-cells-via-interaction-with-stem-cells-from-human-exfoliated-deciduous-teeth
#20
Hyun Nam, Gee-Hye Kim, Jae-Won Kim, Jae Cheoun Lee, Kyunghoon Lee, Sun-Ho Lee
Tooth develops through reciprocal interactions between oral epithelium and oral mesenchyme. To regenerate tooth, both components are necessary to mimic epithelial-mesenchymal interactions. In adult teeth, Hertwig's epithelial root sheath/Epithelial rests of Malassez (HERS/ERM) cells are unique epithelial cells which are derived from oral epithelium. In this study, we investigated whether HERS/ERM cells could have ameloblast-like characteristics via interaction with stem cells from human exfoliated deciduous teeth (SHEDs) as an oral mesenchymal component...
June 14, 2017: Biochemical and Biophysical Research Communications
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