Role of Interlayer Coupling on the Evolution of Band Edges in Few-Layer Phosphorene

Using first-principles calculations, we have investigated the evolution of band edges in few-layer phosphorene as a function of the number of P layers. Our results predict that monolayer phosphorene is an indirect band gap semiconductor and its valence band edge is extremely sensitive to strain. Its band gap could undergo an indirect-to-direct transition under a lattice expansion as small as 1% along the zigzag direction. A semiempirical interlayer coupling model is proposed, which can reproduce the evolution of valence band edges obtained by first-principles calculations well. We conclude that the interlayer coupling plays a dominant role in the evolution of the band edges via decreasing both band gap and carrier effective masses with the increase of phosphorene thickness. Scrutiny of the orbital-decomposed band structure provides a better understanding of the upward shift of the valence band maximum, surpassing that of the conduction band minimum.

Additional chromosomal abnormalities in core-binding factor acute myeloid leukemia

Despite sharing a similar genetic abnormality, patients with core binding factor acute myeloid leukemia (CBF-AML), which is characterized by the presence of t(8;21) or inv(16)/t(16;16), show heterogeneous survival. Other molecular or cytogenetic factors are supposed to have an impact on the prognosis. We enrolled 24 CBF-AML patients to determine the impact of cytogenetic abnormality, and c-KIT, FLT3, NPM1, and CEBPA mutations on the prognosis. Only three patients had the c-KIT mutation (3/24, 12.5%) and one had the FLT3 mutation. However, over half of the patients (14/24) harbored additional cytogenetic changes, including ten with loss of sexual chromosomes (LOS) [all in the t(8;21) group], and six had additional abnormalities (two cases had both LOS and additional abnormalities). From this small-number study, no association was found between c-KIT mutation and survival and relapse rate. However, additional chromosome abnormalities had a significant association with relapse of the disease (P = 0.027). Stem cell transplant had a trend of benefitting patients after relapse (P = 0.065). This implies that chromosome abnormalities occur in CBF-AML and might take part in the heterogeneous nature of CBF-AML.

Effective Energy Transfer via Plasmon-Activated High-Energy Water Promotes Its Fundamental Activities of Solubility, Ionic Conductivity, and Extraction at Room Temperature

Water is a ubiquitous solvent in biological, physical, and chemical processes. Unique properties of water result from water's tetrahedral hydrogen-bonded (HB) network (THBN). The original THBN is destroyed when water is confined in a nanosized environment or localized at interfaces, resulting in corresponding changes in HB-dependent properties. In this work, we present an innovative idea to validate the reserve energy of high-energy water and applications of high-energy water to promote water's fundamental activities of solubility, ionic conductivity, and extraction at room temperature. High-energy water with reduced HBs was created by utilizing hot electrons with energies from the decay of surface plasmon excited at gold (Au) nanoparticles (NPs). Compared to conventional deionized (DI) water, solubilities of alkali metal-chloride salts in high-energy water were significantly increased, especially for salts that release heat when dissolved. The ionic conductivity of NaCl in high-energy water was also markedly higher, especially when the electrolyte's concentration was extremely low. In addition, antioxidative components, such as polyphenols and 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG) from teas, and Polygonum multiflorum (PM), could more effectively be extracted using high-energy water. These results demonstrate that high-energy water has emerged as a promising innovative solvent for promoting water's fundamental activities via effective energy transfer.

Comparison of intra-ocular pressure changes with liquid or flat applanation interfaces in a femtosecond laser platform

Cataract surgery is the most common surgical procedure and femtosecond laser assisted cataract surgery (FLACS) has gained increased popularity. FLACS requires the application of a suction device to stabilize the laser head and focus the laser beam accurately. This may cause a significant escalation in intra-ocular pressure (IOP), which poses potential risks for patients undergoing cataract surgery. In this study we aimed to assess the effect of the Ziemer LDV Z8 femtosecond cataract machine on IOP. We demonstrated through a porcine model that IOP was significantly higher with a flat interface but could be abrogated by reducing surgical compression and vacuum. Pressure was lower with a liquid interface, and further altering angulation of the laser arm could reduce the IOP to 36 mmHg. A pilot series in patients showed comparable pressure rises with the porcine model (30 mmHg). These strategies may improve the safety profile in patients vulnerable to high pressure when employing FLACS with the Ziemer LDV Z8.

Innovative fabrication of a Au nanoparticle-decorated SiO2 mask and its activity on surface-enhanced Raman scattering

Surface-enhanced Raman scattering (SERS) utilizing the well-defined localized surface plasmon resonance (LSPR) of Ag and Au nanoparticles (NPs) under resonant irradiation has emerged as a promising spectroscopy technique for providing vibrational information on trace molecules. The Raman scattering intensity from molecules close to the surface of these finely divided metals can be significantly enhanced by a factor of more than 10(6). In addition to the high sensitivity, the reproducibility of the SERS signal is also an important parameter for its reliable application. In this work, we report on the innovative and facile fabrication of a Au NP-decorated SiO2 mask coated on indium tin oxide (ITO) glass as a SERS array substrate. First, a highly ordered porous SiO2 mask with pore sizes of 350 nm in diameter and wall thickness of 60 nm was deposited on ITO glass by using spin coating. Then, Au NPs were controllably decorated into the pores of the conductive ITO glass-bottomed SiO2 mask by using sonoelectrochemical deposition-dissolution cycling (SEDDC). Experimental results indicate that the SERS effect of Rhodamine 6G (R6G) observed on this developed substrate increases with an increase in the deposition time of Au NPs in SEDDC. The corresponding optimal enhancement factor (EF) that is obtained is ca. 6.5 × 10(7). Significantly, this system achieves an optimal reproducibility under a medium-length deposition time of Au NPs in SEDDC with a relative standard deviation (RSD) of 12% for measurements of five spots on different areas. The low RSD of the SERS signal and the large EF suggest that the developed array system can serve as an excellent spectroscopy platform for practical applications in analytical chemistry.

Fabrication and photoelectric properties of La-doped p-type ZnO nanofibers and crossed p-n homojunctions by electrospinning

La-doped p-type ZnO nanofibers were successfully synthesized by electrospinning, followed by calcination. The microstructure and morphology of the La-doped ZnO nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The field effect curve of individual nanofibers confirms that the resulting La-doped ZnO fibers are p-type semiconductors. The doping mechanism is discussed. Furthermore, crossed p-n homojunction nanofibers were also prepared based on electrospun La-doped p-type ZnO and n-type pure ZnO fibers. The current-voltage curve shows the typical rectifying characteristic of a p-n homojunction device. The turn-on voltage appears at about 2.5 V under the forward bias and the reverse current is impassable.

Enhanced ultraviolet emission from Au/Ag-nanoparticles@MgO/ZnO heterostructure light-emitting diodes: A combined effect of exciton- and photon- localized surface plasmon couplings

Localized surface plasmon (LSP)-enhanced ultraviolet light-emitting diodes (LEDs) based on a Au/MgO/ZnO metal/insulator/semi- conductor heterostructure were fabricated by embedding Ag nanoparticles (Ag-NPs) into MgO dielectric layer. A ~6-fold electroluminescence (EL) enhancement was achieved from the Ag-NPs decorated device. Time-resolved spectroscopy studies, as well as analogue simulation and theoretical estimation based on experimental data, reveal that the internal quantum efficiency and light extraction efficiency of the heterojunction LED are increased ~3-fold and ~2-fold, respectively, as a result of the introduction of Ag LSPs. This result indicates that the observed EL enhancement originates from a combined effect of both exciton-LSP coupling and photon-LSP coupling.

Balsalazide Potentiates Parthenolide-Mediated Inhibition of Nuclear Factor-κB Signaling in HCT116 Human Colorectal Cancer Cells

BACKGROUND/AIMS

Balsalazide is an anti-inflammatory drug used in the treatment of inflammatory bowel disease. Balsalazide can reduce inflammatory responses via several mechanisms, including inhibition of nuclear factor-κB (NF-κB) activity. Parthenolide (PT) inhibits NF-κB and exerts promising anticancer effects by promoting apoptosis. The present investigated the antitumor effects of balsalazide, combined with PT, on NF-κB in a representative human colorectal carcinoma cell line, HCT116.

METHODS

We counted cells and conducted annexin-V assays and cell cycle analysis to measure apoptotic cell death. Western blotting was used investigate the levels of proteins involved in apoptosis.

RESULTS

PT and balsalazide produced synergistic anti-proliferative effects and induced apoptotic cell death. The combination of balsalazide and PT markedly suppressed nuclear translocation of the NF-κB p65 subunit and the phosphorylation of inhibitor of NF-κB. Moreover, PT and balsalazide dramatically enhanced NF-κB p65 phosphorylation. Apoptosis, through the mitochondrial pathway, was confirmed by detecting effects on Bcl-2 family members, cytochrome c release, and activation of caspase-3 and -8.

CONCLUSIONS

Combination treatment with PT and balsalazide may offer an effective strategy for the induction of apoptosis in HCT116 cells.

TGF-β1 polymorphism 509 C>T is associated with an increased risk for hepatocellular carcinoma in HCV-infected patients

Transforming growth factor-beta 1 (TGF-β1), a member of the transforming growth factor beta family, functions as a multi-functional cytokine and plays a key role in cellular growth, proliferation, and differentiation. The 509 C/T polymorphism in the TGF-β1 gene has been implicated in the outcome of hepatitis C virus (HCV) infection; however, little is known regarding the relationship between TGF-β1 gene mutations and the development of hepatocellular carcinoma (HCC) in HCV-infected patients. The aim of the study was to evaluate the effect of the TGF-β1 polymorphisms 509 C>T on the occurrence of HCC in patients chronically infected with HCV in a Chinese Han population. The results showed that HCC patients had a higher frequency of the TGF-β1 -509 TT genotype distribution of the TGF-β1 -509 polymorphism and a lower frequency of the CC genotype. Serum TGF-β1 levels were significantly higher in patients with the TT genotype than in those with the CC genotype. In this study, we confirmed that the TGF-β1 polymorphism 509 C>T is associated with the risk of HCC in HCV-infected patients.

Effect of a pre-microRNA-149 (miR-149) genetic variation on the risk of ischemic stroke in a Chinese Han population

Clinical and experimental data have demonstrated that genetic factors play an important role in determining the susceptibility to ischemic stroke (IS). The present study was performed to clarify the association between the pre-microRNA-149 (miR-149) single nucleotide polymorphism rs71428439 and the risk of IS in the Jiangsu Han population. Polymerase chain reaction and restriction fragment length polymorphism were performed to identify the genotypes of the miR-149 single-nucleotide polymorphism rs71428439 in 730 unrelated subjects (IS, 348; healthy controls, 382). Plasma levels of homocysteine were determined using a radioassay kit. Compared to healthy controls, IS patients had a lower frequency of GG genotype distribution of the hsa-mir-149 polymorphism (11.5 vs 16.0%) and a higher frequency of TT (46.6 vs 39.0%). The risk of IS was significantly lower among subjects carrying the GG genotype than subjects carrying the AA genotype (odds ratio (95% confidence interval): 0.603 (0.382- 0.952), P = 0.030) or at least carrying the G allele than patients carrying the A allele (odds ratio (95% confidence interval): 0.769 (0.620-0.954), P = 0.019). Levels of folate were statistically higher in patients with the TT genotype (8.59 ± 7.75 ng/mL) than in those with the CC genotype (6.32 ± 5.97 ng/mL) in IS patients. Our results suggest that the miR- 149 single nucleotide polymorphism rs71428439 influences plasma levels of homocysteine and is associated with IS risk in the Jiangsu Han population.

CCL5/RANTES is important for inducing osteogenesis of human mesenchymal stem cells and is regulated by dexamethasone

In this study, we examine the effect of chemokine (C-C motif) ligand 5 (CCL5)/Regulated on Activation Normal T cell Expressed and Secreted (RANTES), a pro-inflammatory cytokine on osteogenic differentiation of human mesenchymal stem cells (hMSCs). We found CCL5 expression was increased during osteogenic differentiation of hMSCs and CCL5 expression is dependent on the presence of dexamethasone. Knocking down endogenous CCL5 expression blocked osteogenesis, as revealed by decreasing alkaline phosphatase (ALP) activity and a reduction in the expression levels of ALP, bone sialoprotein (BSP), and osteopontin (OPN). Of note, the overexpression of CCL5 was sufficient to increase ALP expression and activity. Moreover, the down-regulation of chemokine (C-C motif) receptor 1 (CCR1), one of the CCL5 receptors, significantly decreased the osteogenesis of hMSCs. Interestingly, the down-regulation of CCR1, but not CCL5, was sufficient to affect the cell numbers during the process of osteogenesis. Our findings reveal that both CCL5 and CCR1 are required for osteogenesis of human MSCs, CCL5 is sufficient for the osteogenesis, and provide a novel link between dexamethasone and CCL5 in human osteogenesis.

Correction: Surface-enhanced Raman scattering on a silver film-modified Au nanoparticle-decorated SiO2 mask array

Correction for ‘Surface-enhanced Raman scattering on a silver film-modified Au nanoparticle-decorated SiO₂ mask array’ by Chi-Ching Chang et al., RSC Adv., 2015, 5, 66096–66103.

Surface-enhanced Raman scattering on a silver film-modified Au nanoparticle-decorated SiO2 mask array

SERS of R6G absorbed on this developed array exhibits a higher intensity by ca. 30-fold, as compared with that of R6G absorbed on the Au NP-based array without the modification of Ag films.

Quantitative evaluation on activated property-tunable bulk liquid water with reduced hydrogen bonds using deconvoluted Raman spectroscopy

Interesting properties of water with distinguishable hydrogen-bonding structure on interfacial phase or in confined environment have drawn wide attentions. However, these unique properties of water are only found within the interfacial phase and confined environment, thus, their applications are limited. In addition, quantitative evaluation on these unique properties associating with the enhancement of water's physical and chemical activities represents a notable challenge. Here we report a practicable production of free-standing liquid water at room temperature with weak hydrogen-bonded structure naming Au nanoparticles (NPs)-treated (AuNT) water via treating by plasmon-induced hot electron transfer occurred on resonantly illuminated gold NPs (AuNPs). Compared to well-known untreated bulk water (deionized water), the prepared AuNT water exhibits many distinct activities in generally physical and chemical reactions, such as high solubilities to NaCl and O2. Also, reducing interaction energy within water molecules provides lower overpotential and higher efficiency in electrolytic hydrogen production. In addition, these enhanced catalytic activities of AuNT water are tunable by mixing with deionized water. Also, most of these tunable activities are linearly proportional to its degree of nonhydrogen-bonded structure (DNHBS), which is derived from the O-H stretching in deconvoluted Raman spectrum.

Room-temperature sensor based on surface-enhanced Raman spectroscopy

As reported in the literature, several factors, such as scattering cross sections, polarisability and wavelength suitability, contribute to increased SERS enhancement. In general, the advantage of surface-enhanced Raman scattering (SERS)-active Ag nanoparticles (NPs) is their higher SERS enhancement over Au NPs because the molar extinction coefficient of the Ag NPs is the highest of its kind among metals. Nevertheless, the corresponding SERS-active hot spots on Au are of inherently greater stability than on Ag. In this work, innovative temperature sensors based on SERS-active Au and Ag substrates prepared by sonoelectrochemical deposition-dissolution cycles (SEDDCs) are first reported. The SERS intensity of the model probe molecules of Rhodamine 6G (R6G) adsorbed on a SERS-active Ag substrate is monotonically increased from 25 to 50 °C. Moreover, this temperature-dependent intensity is linear with a slope of ca. 430 cps per °C between 25 to 45 °C. In addition, the reversibility and reusability of the developed temperature sensors are evaluated after the R6G-adsorbed sensors are alternately exposed to the temperatures of 25 and 45 °C in a sealed chamber. After every five cycles, the SERS spectra of treated substrates were recorded and compared with those of the as-prepared substrates. Experimental results indicate that SERS enhancement capability is mostly reversible based on 90% intensity of the Raman signal being maintained for the SERS-active Au substrate after 25 cycles (only 15 cycles for the Ag substrate).

ZnO ultraviolet random laser diode on metal copper substrate

Direct fabrication of light emitting devices on metal substrates is highly desirable due to their advantages of high thermal conductivity and light reflection. In this work, we demonstrated a feasibility of directly fabricating ZnO-based ultraviolet laser diodes on metal substrates. By introducing an anti-oxidation buffer layer, Au/MgO/ZnO metal-insulator-semiconductor heterojunction devices are successfully fabricated on the copper substrate. Electrically pumped ultraviolet random lasing was achieved from ZnO active layer. The use of copper substrate offers some merits, including lower thermal effect and higher stability of emission wavelength.

Cardiolipin-incorporated liposomes with surface CRM197 for enhancing neuronal survival against neurotoxicity

CRM197-grafted liposomes containing cardiolipin (CL) (CRM197/CL-liposomes) were used to enhance the permeability of neuron growth factor (NGF) across the blood-brain barrier (BBB) for promoting the neuroprotective effect of NGF. CRM197/CL-liposoms were incubated with a monolayer of human astrocyte (HA)-regulated human brain-microvascular endothelial cells (HBMECs) and employed to rescue SK-N-MC cells with insult of fibrillar β-amyloid peptide (1-42) (Aβ1-42). An increase in the CL mole percentage enhanced the particle size, absolute value of zeta potential, NGF entrapment efficiency, CRM197 grafting efficiency, viability of HBMECs, HAs, and SK-N-MC cells, and BBB permeability of propidium iodide (PI) and NGF, and reduced the transendothelial electrical resistance (TEER). In addition, an increase in the CRM197 weight percentage increased the particle size, absolute value of zeta potential, viability of HBMECs and HAs, and BBB permeability of PI and NGF, and decreased the CRM197 grafting efficiency and TEER. CRM197/CL-liposomes have the ability to target the BBB and to reduce neurotoxicity of Aβ142 and can be promising formulations for treating Alzheimer's disease in future medicinal application.

Active and stable liquid water innovatively prepared using resonantly illuminated gold nanoparticles

The properties of confined liquid water, or liquid water in contact with hydrophobic surfaces, are significantly different from those of bulk liquid water. However, all of water's commonly described properties are related to inert "bulk liquid water" which comprises a tetrahedral hydrogen-bonded network. In this work, we report an innovative and facile method for preparing small water clusters (SWCs) with reduced affinity hydrogen bonds by letting bulk water flow through supported Au nanoparticles (NPs) under resonant illumination to give NP-treated (AuNT) water at constant temperature. Utilizing localized surface plasmon resonance on illuminated Au NPs, the strong hydrogen bonds of bulk water can be disordered when water is located at the illuminated Au/water interface. The prepared SWCs are free of Au NPs. The energy efficiency for creating SWCs is ∼17%. The resulting stable AuNT water exhibits distinct properties at room temperature, which are significantly different from the properties of untreated bulk water, examples being their ability to scavenge free hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radicals and to effectively reduce NO release from lipopolysaccharide-induced inflammatory cells.