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2D materials are considered as intriguing building blocks for next-generation optoelectronic devices. However, their photoresponse performance still needs to be improved for practical applications. Here, ultrasensitive 2D phototransistors are reported employing chemical vapor deposition (CVD)-grown 2D Bi

Graphene has been well studied to be an excellent thermoelectric (TE) material of choice for thermal detection. It is widely considered a key enabler for next-in-class infrared (IR) detectors given its superb carrier mobility, sensitivities and broadband absorption in far-IR range surpassing that of current thermopiles. Normally, TE studies are conducted using graphene exfoliated from graphite crystal. It is then transferred onto Si/SiO2 substrate and fabricated into Hall bar configuration with microheater at one end. A gate voltage (Vg) is passed through the substrate and the response is examined in vacuum condition. By tuning the Vg, one can possibly obtain different thermoelectric power (TEP) values. The challenge is to maintain optimum Vg for the TE device to function which requires higher power consumption. This translate to the need for additional power supply. In this report, we proposed CVDG as TE material. Typically, CVDG are synthesized on Cu film and eventually transferred onto Si/SiO2 substrate. The benefit of CVDG is that it is large area, relatively inexpensive and does not require a Vg with associated circuitry. For the first time, CVDG system was extended to nonvacuum condition to simulate open detector system where detector is exposed to sensing environment. Average TEP was measured to be 168μV/K at 298K. Moreover, CVDG is tested to be stable in air over several months with little or no decrease in performance. A comprehensive characterization between exfoliated and CVDG will be presented. In addition, measurement results for vacuum and non-vacuum detector mode will be compared as well.

A sensitive and specific liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantitative analysis of 1,2:5,6-dianhydrogalactitol (DAG) in mouse plasma and tissues. Sodium diethyldithiocarbamate (DDTC) was used as the derivatization reagent to improve its LC-MS/MS behavior. Analytes were separated on a Welch Ultimate XB-CN column with a mobile phase consisting of acetonitrile and 0.1% formic acid solution (65:35). The MS analysis was conducted by positive electrospray ionization in multiple-reaction monitoring (MRM) mode. Good linearity (r2 > 0.9958) was observed over the concentration range of 1–1000 ng/mL in plasma and tissue homogenates (brain, liver, heart, spleen, lung and kidney). The intra- and inter-batch precision and accuracy of DAG in plasma and brain samples were all within the acceptable limits. The extraction recovery was stable and no significant matrix effects were observed. The method was successfully applied to study the pharmacokinetic and tissue distribution of DAG in mice after intravenous administration. DAG could cross the blood-brain barrier and had limited liver distribution. Rat primary hepatocytes in vitro experiments demonstrated that DAG had a safe profile in liver.

Magnolia sinostellata is an endemic species of Magnoliaceae that is narrowly distributed in the south of Zhejiang Province, China. To explore the genetic diversity and population structure of this endangered species, this study developed sequence tag-simple sequence repeat (EST-SSR) markers based on transcriptome data of M. sinostellata. In total, 25472 SSRs were identified among 110644 unique assembled sequences with a total of 90.83 Mb and an average frequency of 23.02%. The mononucleotide (33.53%) and dinucleotide (42.08%) motifs appeared to be the most abundant. In total, 150 potential loci were randomly selected to validate the quality of the developed SSR markers; an effective PCR rate of 32.00% and a polymorphism rate of 15.33% were obtained for these loci. After performing sequencing and cloning for validation, 23 pairs of SSR primers were retained and used to characterize the genetic diversity and population structure of M. sinostellata. Overall, 204 alleles were amplified. The results of Shannon’s information index (I), heterozygosity (Ho), heterozygosity (He) and Nei’s expected heterozygosity (H) indicated rich genetic diversity in M. sinostellata. However, the high inbreeding coefficient and differential coefficient suggest that serious genetic drift occurred within populations, and genetic differentiation is apparent among the populations. Consequently, although M. sinostellata has high genetic diversity among populations, it is still in a serious and dangerous condition. Habitat destruction caused by human activities is the main threat to this species, and enhancing the species abundance by adopting some conservation measures should be favourable for saving the species.

FBG has been applied to fusion field and used to monitor surface strain and temperature of tokamak tungsten divertor component under baking and high heat flux tests, respectively. This is a summary of the works.

In this work, a three dimensional (3D) interconnected carbon network consisting of ultrathin graphite (UG) and carbon nanotubes (CNTs) on Ni foam is fabricated and employed as a novel type of substrate for mesoporous NiCo2O4 nano-needles. The successfully synthesized NiCo2O4 nano-needles/CNTs/UG on Ni foam has many advantages including facile electrolyte access and direct conducting pathways towards current collectors, which enable it to be a promising electrode material in battery-like electrochemical energy storage. Encouragingly, a high capacity of 135.1 mAh/g at the current density of 1 A/g, superior rate performance and also stable cycling for 1200 cycles at the current density of 5 A/g have been demonstrated in this novel material.

Recently, anisotropic 2D materials, such as black phosphorus and rhenium disulfides (ReS2 ), have attracted a lot attention because of their unique applications on electronics and optoelectronics. In this work, the direct growth of high-quality ReS2 atomic layers and nanoribbons has been demonstrated by using chemical vapor deposition (CVD) method. A possible growth mechanism is proposed according to the controlled experiments. The CVD ReS2-based filed-effect transistors (FETs) show n-type semiconducting behavior with a current on/off ratio of ≈10(6) and a charge carrier mobility of ≈9.3 cm(2) Vs(-1). These results suggested that the quality of CVD grown ReS2 is comparable to mechanically exfoliated ReS2, which is also further supported by atomic force microscopy imaging, high-resolution transmission electron microscopy imaging and thickness-dependent Raman spectra. The study here indicates that CVD grown ReS2 may pave the way for the large-scale fabrication of ReS2-based high-performance optoelectronic devices, such as anisotropic FETs and polarization detection.

Organic–inorganic heterostructures are an emerging topic that is very interesting for optoelectronics. Here, non-conventional p–n junctions are investigated using organic rubrene single crystal and 2D MoS2 as the p- and n-type semiconducting materials, respectively. The current-rectifying behavior is clearly observed in the junction device. The rectification ratio can be electrically tuned by the gate voltage due to the 2D nature of the heterostructure. The devices also show good photoresponse properties with a photoresponsivity of ≈500 mA W−1 and a fast response time. These findings suggest a new route to facilitate the design of nanoelectronic and optoelectronic devices based on layered inorganics and organics.

Microsupercapacitors (MSCs), as one type of significant power source or energy storage unit in microelectronic devices, have attracted more and more attention. However, how to reasonably design electrode structures and exploit the active materials to endow the MSCs with excellent performances in a limited surface area still remains a challenge. Here, a reduced graphene oxide (RGO)/manganese dioxide (MnO2)/silver nanowire (AgNW) ternary hybrid film (RGMA ternary hybrid film) is successfully fabricated by a facile vacuum filtration and subsequent thermal reduction, and is used directly as a binder-free electrode for MSCs. Additionally, a flexible, transparent, all-solid state RMGA-MSC is also built, and its electrochemical performance in an ionic liquid gel electrolyte are investigated in depth. Notably, the RGMA-MSCs display superior electrochemical properties, including exceptionally high rate capability (up to 50000 mV·s(-1)), high frequency response (very short corresponding time constant τ0 = 0.14 ms), and excellent cycle stability (90.3% of the initial capacitance after 6000 cycles in ionic liquid gel electrolyte). Importantly, the electrochemical performance of RGMA-MSCs shows a strong dependence on the geometric parameters including the interspace between adjacent fingers and the width of the finger of MSCs. These encouraging results may not only provide important references for the design and fabrication of high-performance MSCs, but also make the RGMA ternary hybrid film promising for the next generation film lithium ion batteries and other energy storage devices.

Metal oxides have attracted considerable attention as promising electrode materials for energy storage, but the use of metal oxides for electrodes still faces challenges such as attaining high capacity, good cycle stability, and high-rated performance. Therefore, rational design of electrode architectures and assembling metal oxides into desired structures to further enhance electrochemical performance is necessary. Here, novel 3D electrode architectures consisting of 3D ultra-thin graphite film (UGF)/carbon nanotubes (CNTs) uniformly covered by NiO nanosheets are successfully constructed by a chemical vapor deposition and subsequent electrodeposition, which are directly used as bind-free electrodes for supercapacitors and Li-ion batteries. In such composite structures, 3D UGF/CNTs serve as substrates for NiO nanosheet decoration, and act as spacers to stabilize the composite structure, making the active surfaces of NiO nanosheets accessible for electrolyte penetration and accommodating volume changes during charge/discharge processes. As expected, 3D UGF/CNTs/NiO as electrode material for supercapacitors showed high specific capacitance (750.8 F g−1 at current density of 1 A g−1), superior rate performance (capacitance of 575.6 F g−1 at 10 A g−1) and excellent cycle stability (no decay after 3000 cycles). Moreover, the 3D CNTs/UGF/NiO composite also exhibited enhanced lithium storage properties as anode materials for Li-ion batteries.

Background Serelaxin, a recombinant form of human relaxin-2, is in development for treating acute heart failure (AHF) and a Phase II study in Japanese AHF patients was conducted. Methods and results A randomized, double-blind, placebo-controlled study of serelaxin at 10 and 30 µg·kg(-1)·day(-1)continuous intravenous infusion for up to 48 h, added to standard care for Japanese AHF patients. Primary endpoints were adverse events (AEs) through Day 5, serious AEs (SAEs) through Day 14, and serelaxin pharmacokinetics. Secondary endpoints included changes in systolic blood pressure (SBP) and cardiorenal biomarkers. A total of 46 patients received the study drug and were followed for 60 days. The observed AE profile was comparable between the groups, with no AEs of concern. Dose-dependent increase in the serum concentration of serelaxin was observed across the 2 dose rates of serelaxin. A greater reduction in SBP was observed with serelaxin 30 µg·kg(-1)·day(-1)vs. placebo (-7.7 [-16.4, 1.0] mmHg). A greater reduction in NT-proBNP was noted with serelaxin (-50.8% and -54.9% for 10 and 30 µg·kg(-1)·day(-1), respectively at Day 2). Conclusions Serelaxin was well tolerated in this study with Japanese AHF patients, with no AEs of concern and favorable beneficial trends on efficacy. These findings support further evaluation of serelaxin 30 µg·kg(-1)·day(-1)in this patient population.

A key challenge of the carbon dioxide electroreduction (CO2RR) on Cu-based nanoparticles is its low faradic selectivity toward higher-value products such as ethylene. Here, we demonstrate a facile method for tuning the hydrocarbon selectivities on CuO

Infectious pancreatic necrosis virus (IPNV) is a member of the Aquabirnavirus genus, which caused mass mortality (nearly 100%) in farmed rainbow trout (Oncorhynchus mykiss) in aquaculture farms in 2016, China. Major clinical signs included decreased appetite, mucous-like stools, and darkened pigmentation. Pathological changes in moribund fish were observed, such as marked vacuolar degeneration of the pancreatic cells with pyknotic nucleus and decreased zymogen granules, severe hemorrhage in the liver, and tumidness of respiratory epithelium in gills. In addition, the tissue fluid of diseased fish could produce a cytopathic effect (CPE) in RTG-2 cells. The presence of specific 206bp fragments by the reverse transcription-polymerase chain reaction (RT-PCR) using tissue homogenate of diseased fish and supernatant of infected cells revealed that IPNV could be confirmed. The pathogenicity test of cell culture supernatant detected cumulative mortality of 80%, and the clinical symptoms observed in the moribund and dead fish were similar to the naturally infected fish. Furthermore, the sequence analysis of VP2 gene showed that the isolated virus strain belonged to genogroup 1, and 97% homology with the Mexican IPNV isolate was found. To our knowledge, this is the first report on IPNV natural infection in the southwest of China.

A monolayer WS 2 enhanced surface plasmon resonance biosensor is proposed. We theoretically and experimentally demonstrate that the sensitivity could reach to 3.5×104 deg/RIU, which was 300% higher than that of the conventional configuration.

Although it is well known that the performances of two-dimensional transition metal dichalcogenide (2D-TMD) based devices are strongly affected by humidity, the roles of water molecules in the electronic properties of 2D-TMDs are still unclear. In this work, the influence of water molecules on the electrical properties of monolayer molybdenum disulfide (MoS2) is studied systemically using the dielectric force microscopy (DFM) technique. Taking the advantage of the DFM technique and other nondestructive characterization techniques, the electronic properties (surface potential, dielectrics, and carrier mobility) of atomically thin MoS2 exposed to different levels of humidity are investigated. Furthermore, Raman spectroscopy manifested the correlation between the optical phonon and the mobility drop of MoS2 flakes when subjected to humidity variations. Our results provide an in-depth understanding of the mechanism of water molecules interacting with MoS2. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Published version

Secretory human interleukin 4 (hIL4) is an N-glycosylated pleiotropic cytokine. It is unknown if these N-linked glycans are required and essential for hIL4 protein stability, expression, secretion, and activity in vivo, and hIL4 expressed from Pichia pastoris yeast has not been tested to date. In this study, we successfully expressed human hIL4 in P. pastoris, the methylotrophic yeast, with a yield of 15.0mg/L. Using the site-directed mutagenesis technique, we made two mutant hIL4 cDNA clones (N38A and N105L) and subsequently expressed them in P. pastoris to analyze the relevant function of each N-glycosylation site on hIL4. Our results demonstrate that the glycosylation only occurs at position Asn38, but not Asn105. The glycosylated form of hIL4 unexpectedly has lower biological activity and lower stability when compared to its non-glycosylated form. The implications of this are discussed.

The number and activity of brown adipocytes are linked to the ability of mammals to resist body fat accumulation. In some conditions, certain white adipose tissue (WAT) depots are readily convertible to a ‘‘brown-like’’ state, which is associated with weight loss. Irisin, a newly identified hormone, is secreted by skeletal muscles into circulation and promotes WAT “browning” with unknown mechanisms. In the current study, we demonstrated in mice that recombinant irisin decreased the body weight and improved glucose homeostasis. We further showed that irisin upregulated uncoupling protein-1 (UCP-1; a regulator of thermogenic capability of brown fat) expression. This effect was possibly mediated by irisin-induced phosphorylation of the p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal–related kinase (ERK) signaling pathways. Inhibition of the p38 MAPK by SB203580 and ERK by U0126 abolished the upregulatory effect of irisin on UCP-1. In addition, irisin also promoted the expression of betatrophin, another newly identified hormone that promotes pancreatic β-cell proliferation and improves glucose tolerance. In summary, our data suggest that irisin can potentially prevent obesity and associated type 2 diabetes by stimulating expression of WAT browning-specific genes via the p38 MAPK and ERK pathways.

Thanks to its excellent heat removal capability, good performance under high heat flux (HHF) test and higher critical heat flux (CHF) value, the water cooled monoblock type plasma facing component (PFC) will be the optimal choice for divertor targets of CFETR and future fusion reactor. The conventional ITER-like W/Cu monoblock PFC employs a soft Cu interlayer to relax thermal stress that has deteriorative irradiation effects of swelling and embrittlement by transmutation and would undergo plastic fatigue under HHF loads. To solve these issues, W/Cu monoblock with functional graded material (FGM) interlayer is designed for CFETR and future fusion reactor. The two parameters that are the number and thickness of the FGM layers are optimized via thermal and stress simulation by finite element method. The simulation result shows that FGM interlayer plays an important role in alleviating stress. And it is deduced that the optimized number and thickness of the FGM layers are 3 layers and 0.3 mm of each layer, respectively.

Conventional Langmuir probes used in tokamak devices get damaged easily and even melt when exposed to divertor plasma with high thermal and particle loads. Recently, the Institute of Plasma Physics, Chinese Academy of Science, aimed to overcome this issue by designing and manufacturing an uncompensated tungsten/oxygen-free copper (OFC)/CuCrZr-alloy structure-based actively water-cooled Langmuir probe, which showed excellent heat removal capability in finite element analyses (FEA). The heat resistance and antiheat fatigue property of the proposed probe were verified by conducting electron beam high heat flux (HHF) tests. Results show that the maximum temperatures of the probe’s tungsten surface were approximately 445 °C and 875 °C under heat loads of 10 and 20 MW/m2, respectively. The probe successfully passed 600 cycles of 10 and 20 MW/m2 thermal fatigue HHF tests. Moreover, no obvious damages were found on the tungsten surface and W/OFC/CuCrZr joints. FEA and HHF test results proved the reliability of the newly designed uncompensated probe. In view of this progress, it is promising to apply this actively water-cooled probe in tokamak devices for plasma diagnostics.Conventional Langmuir probes used in tokamak devices get damaged easily and even melt when exposed to divertor plasma with high thermal and particle loads. Recently, the Institute of Plasma Physics, Chinese Academy of Science, aimed to overcome this issue by designing and manufacturing an uncompensated tungsten/oxygen-free copper (OFC)/CuCrZr-alloy structure-based actively water-cooled Langmuir probe, which showed excellent heat removal capability in finite element analyses (FEA). The heat resistance and antiheat fatigue property of the proposed probe were verified by conducting electron beam high heat flux (HHF) tests. Results show that the maximum temperatures of the probe’s tungsten surface were approximately 445 °C and 875 °C under heat loads of 10 and 20 MW/m2, respectively. The probe successfully passed 600 cycles of 10 and 20 MW/m2 thermal fatigue HHF tests. Moreover, no obvious damages were found on the tungsten surface and W/OFC/CuCrZr joints. FEA and HHF test results proved the reliability of th...

The need of a sustainable society to advance towards a circular economy, in which there is a balance between the emission and capture of anthropogenic gases like carbon dioxide (CO2), is of utmost scientific and technological importance to ensure the increase or rather preservation of the current prosperity for future generations. The growing global population and increase in worldwide prosperity is tightly connected to a rise in power consumption. Traditionally, this energy demand is supplied by the combustion of fossil fuels, resulting in growing emission of greenhouse gases. In this, CO2 is a key issue which climatic influences and general mitigation is rigorously disused not only in scientific field, but in politics as well. Here, the electrochemical CO2 reduction reaction (CO2RR) is posing as one potential technology, to address questions of power storage for renewable energies and sustainable usage of natural resources. The CO2RR shows a diverse spectrum of products ranging from liquid fuels, as ethanol and propanol, to gaseous building blocks for the chemical industry, as ethylene and CO. The selectivity of this reaction is highly dependent on the nature of the catalyst and is always competing with the hydrogen evolution reaction (HER), due to the aqueous conditions. Recently, very selective and active catalysts have been developed for the production of CO and formic acid. Both compounds are comparably easy to produce, as the reduction only involves the transfer of 2 electrons. Unfortunately, the production of valuable hydrocarbons is much more difficult and suffers from losses in selectivity due to the highly complex reaction mechanism. So far, only copper showed acceptable production rates for hydrocarbons, owing to the favorable binding energies of intermediates. Recent studies have been focused on fundamental parameters to control the selectivity of this complex reaction on copper for C2+ species, ranging from catalyst design to electrolyte selection. On the catalyst side, many effects as the presence of (100) facets1, grain boundaries2 and oxides3 have been suggested to be beneficial, whereas influences of buffer capacity and local electric field brought additional advantages by choice of the electrolyte. While promising results were shown, many studies only focused on low-current density, which are far from an industrial application. Here, at least 200 mA cm-2 are needed for a functional electrolyzer. This poses as a discrepancy between research and application and raises the question if the results from fundamental studies can be transferred to full size electrolyzers.4 For this, we are presenting a cubic Cu2O catalyst, which we investigate in a comprehensive study, moving from initial tests in an H-Cell towards high currents on a Gas Diffusion Electrode (GDE) in a Flow-Cell setup. To deconvolute the parameters dictating CO2RR selectivity, we used X-Ray-Diffraction (XRD), quasi in-situ X-Ray Photon Spectroscopy (XPS) and operando X-ray Absorption Spectroscopy (XAS) to trace phase changes during reaction, in addition to morphological investigations by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). This complementary analysis depicts a highly dynamic system, in which the reduction of oxidized Cu progresses from the surface towards deeper layers, resulting in a purely metallic, defect-rich material. We further focus on performance tests of our Cu2O catalyst at high current density of up to 700 mA cm-2 in a flow-electrolyzer. By varying system parameters as mass loading and nafion content we observe strong changes in selectivity and activity during CO2RR, which we correlate to accessibility of the active copper sites and issues of mass transport. We further discuss the role of surface pH at high current density by varying electrolyte concentration and therefore buffer capacity. Our study suggests distinct differences between CO2RR in electrochemical cells for fundamental studies at low currents compared to tests at high currents in a flow-electrolyzer. Furthermore, we show how recent results from literature translate to performance at high current density and comment on the importance of electrode preparation. Y. Hori, I. Takahashi, O. Koga and N. Hoshi, Journal of Molecular Catalysis A: Chemical, 2003, 199, 39-47. A. Verdaguer-Casadevall, C. W. Li, T. P. Johansson, S. B. Scott, J. T. McKeown, M. Kumar, I. E. L. Stephens, M. W. Kanan and I. Chorkendorff, Journal of the American Chemical Society, 2015, 137, 9808-9811. H. Mistry, A. S. Varela, C. S. Bonifacio, I. Zegkinoglou, I. Sinev, Y.-W. Choi, K. Kisslinger, E. A. Stach, J. C. Yang, P. Strasser and B. R. Cuenya, Nature Communications, 2016, 7, 12123. T. Burdyny and W. A. Smith, Energy & Environmental Science, 2019, DOI: 10.1039/c8ee03134g.

Strong interactions between surface plasmons in ultra-compact nanocavities and excitons in two dimensional materials have attracted wide interests for its prospective realization of polariton devices at room temperature. Here, we propose a continuous transition from weak coupling to strong coupling between excitons in MoS2 monolayer and highly localized plasmons in ultra-compact nanoantenna. The nanoantenna is assembled by a silver nanocube positioned over a gold film and separated by a dielectric spacer layer. We observed a 1570-fold enhancement in the photoluminescence at weak coupling regime in hybrid nanocavities with thick spacer layers. The interaction between excitons and plasmons is then directly prompted to strong coupling regime by shrinking down the thickness of spacer layer. Room temperature formation of polaritons with Rabi splitting up to 190 meV was observed, which is the largest plasmon-exciton Rabi splitting reported in two dimensional materials. Numerical calculations quantified the relation between coupling strength, local density of states and spacer thickness, and revealed the transition between weak coupling and strong coupling in nanocavities. The findings in this work offer a guideline for feasible designs of plasmon-exciton interaction systems with gap plasmonic cavities.

In the face of the global energy challenge and progressing global climate change, renewable energy systems and components, such as fuel cells and electrolyzers, which close the energetic oxygen and carbon cycles, have become a technology development priority. The electrochemical oxygen reduction reaction (ORR) and the direct electrochemical carbon dioxide reduction reaction (CO2 RR) are important electrocatalytic processes that proceed at gas diffusion electrodes of hydrogen fuel cells and CO2 electrolyzers, respectively. However, their low catalytic activity (voltage efficiency), limited long-term stability, and moderate product selectivity (related to their Faradaic efficiency) have remained challenges. To address these, suitable catalysts are required. This review addresses the current state of research on Pt-based and Cu-based nanoalloy electrocatalysts for ORR and CO2 RR, respectively, and critically compares and contrasts key performance parameters such as activity, selectivity, and durability. In particular, Pt nanoparticles alloyed with transition metals, post-transition metals and lanthanides, are discussed, as well as the material characterization and their performance for the ORR. Then, bimetallic Cu nanoalloy catalysts are reviewed and organized according to their main reaction product generated by the second metal. This review concludes with a perspective on nanoalloy catalysts for the ORR and the CO2 RR, and proposes future research directions.

Ni@Pd/C catalysts were synthesized, using Ni/C with different crystalline structures prepared with various ligands. A series of characterizations were performed by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy. The results indicated the electrocatalysts with amorphous/crystalline (denoted as Nia and Nic) Ni structures decorated with Pd. The formic acid electrocatalytic oxidation results showed that the peak current of Nia@Pd/C was about 1.2 times higher than that of Nic@Pd/C. The good electrochemical performance and stability of Pd-modified amorphous Ni substrate reveals that the core structure plays an important role in the electrocatalytic activity and the change of the structure can improve the activity and stability of electrocatalysts.

Designed assembly of hollow nanostructures with well-defined non-spherical shapes is of great scientific and practical value and remains a great challenge. This paper presents a facile and one-pot hydrothermal synthesis of ZnSnO3 nanocages with geometrical cube-shape. The time-dependent hollowing evolution of the ZnSnO3 samples reveals a self-templating organization process, in which solid nanocubes of ZnSnO3 are formed firstly. Then due to the rapid coprecipitation process, the metastable inner part of the solid cubes dissolves and redeposits to the outer surface via Ostwald ripening, and finally the resultant hollowing process is achieved and ZnSnO3 crystallites reorganize into hollow archetectures. Moreover, the gas-sensing performance of these ZnSnO3 nanocages to formaldehyde (HCHO) is investigated. Due to the hollow interiors and good-permeation surfaces, these ZnSnO3 nanocages exhibit higher response, faster response-recovery, and other better sensing characteristics to HCHO compared with the solid ZnSnO3 nanocubes.

Due to the intriguing optical and electronic properties, 2D materials have attracted a lot of interest for the electronic and optoelectronic applications. Identifying new promising 2D materials will be rewarding toward the development of next generation 2D electronics. Here, palladium diselenide (PdSe2), a noble-transition metal dichalcogenide (TMDC), is introduced as a promising high mobility 2D material into the fast growing 2D community. Field-effect transistors (FETs) based on ultrathin PdSe2 show intrinsic ambipolar characteristic. The polarity of the FET can be tuned. After vacuum annealing, the authors find PdSe2 to exhibit electron-dominated transport with high mobility (µe (max) = 216 cm2 V−1 s−1) and on/off ratio up to 103. Hole-dominated-transport PdSe2 can be obtained by molecular doping using F4-TCNQ. This pioneer work on PdSe2 will spark interests in the less explored regime of noble-TMDCs. NRF (Natl Research Foundation, S’pore) ASTAR (Agency for Sci., Tech. and Research, S’pore) MOE (Min. of Education, S’pore) Accepted version

Antimicrobial peptides (AMPs) are small peptides and play important roles in host innate immune response against microbial invasion. Aquatic animals secrete different kinds of antimicrobial peptides which have antimicrobial activity towards microorganisms. NK-lysins, mature peptides produced by cytotoxic T lymphocytes and natural killer cells, are comprised of 74–78 amino acid residues, demonstrating broad-spectrum antimicrobial activity against bacteria, fungi, protozoa, and parasites. In this study, three distinct NK-lysin mature peptide (mNKLs), transcripts (76 amino acid residues) cloned from the channel catfish (Ictalurus punctatus) head kidney were ligated into plasmid vector pET-32a(+) to express the mNKLs fusion protein. The fusion protein was successfully expressed in E. coli Rosetta (DE3) under optimized conditions. After purification by affinity column chromatography, the fusion protein was successfully cleaved by enterokinase and released the peptide mNKLs. Tricine-SDS-PAGE results showed that mNKLs (approximately 8.6 kDa) were successfully expressed. The purified peptide mNKLs exhibited antibacterial activity against Staphylococcus aureus and E. coli.

Vertical piezoelectricity in atomic thin materials could have applications in sensors and microelectromechanical devices., Driven by the development of high-performance piezoelectric materials, actuators become an important tool for positioning objects with high accuracy down to nanometer scale, and have been used for a wide variety of equipment, such as atomic force microscopy and scanning tunneling microscopy. However, positioning at the subatomic scale is still a great challenge. Ultrathin piezoelectric materials may pave the way to positioning an object with extreme precision. Using ultrathin CdS thin films, we demonstrate vertical piezoelectricity in atomic scale (three to five space lattices). With an in situ scanning Kelvin force microscopy and single and dual ac resonance tracking piezoelectric force microscopy, the vertical piezoelectric coefficient (d33) up to 33 pm·V−1 was determined for the CdS ultrathin films. These findings shed light on the design of next-generation sensors and microelectromechanical devices.

Due to the novel optical and optoelectronic properties, 2D materials have received increasing interests for optoelectronics applications. Discovering new properties and functionalities of 2D materials is challenging yet promising. Here broadband polarization sensitive photodetectors based on few layer ReS2 are demonstrated. The transistor based on few layer ReS2 shows an n-type behavior with the mobility of about 40 cm2 V−1 s−1 and on/off ratio of 105. The polarization dependence of photoresponse is ascribed to the unique anisotropic in-plane crystal structure, consistent with the optical absorption anisotropy. The linear dichroic photodetection with a high photoresponsivity reported here demonstrates a route to exploit the intrinsic anisotropy of 2D materials and the possibility to open up new ways for the applications of 2D materials for light polarization detection. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Accepted version

Irisin, a newly discovered myokine, is considered as a promising candidate for the treatment of metabolic disturbances and cardiovascular diseases. In the present study, we used two animal models, apolipoprotein E-deficient mice fed on a high-cholesterol diet and a mouse carotid partial ligation model to test the anti-atherosclerotic effect of irisin. Irisin treatment (0.5 μg/g body weight/day) significantly reduced the severity of aortic atherosclerosis in apolipoprotein E-deficient mice fed on a high-cholesterol diet and suppressed carotid neointima formation in a carotid partial ligation model. It was associated with decreased inflammation and cell apoptosis in aortic tissues. In addition, in a cell culture model, irisin restored ox-LDL-induced human umbilical vein endothelial cell dysfunction by reducing the levels of inflammatory genes via inhibiting the reactive oxygen species (ROS)/ p38 MAPK/ NF-κB signaling pathway activation and inhibiting cell apoptosis via up-regulating Bcl-2 and down-regulating Bax and caspase-3 expression. Our study demonstrated that irisin significantly reduced atherosclerosis in apolipoprotein E-deficient mice via suppressing ox-LDL-induced cell inflammation and apoptosis, which might have a direct therapeutic effect on atherosclerotic diseases.

A rapid LC-MS/MS method with good accuracy and sensitivity was developed and validated for the pharmacokinetics study of metoprolol (MP) in beagle dogs. The plasma samples were simply precipitated by methanol and then analyzed by LC-MS/MS. An Ultimate XB-C₁₈ column (150 × 2.1 mm ID, 5 μm) was used for separation, with methanol-water containing 0.2% formic acid (65:35, v/v) as the mobile phase at a flow rate of 0.2 mL/min. Monitoring ions of MP and internal standard (hydroxypioglitazone) were m/z 268.1/115.6 and m/z 373.1/150.2, respectively. The linear range was 3.03-416.35 ng/mL with an average correlation coefficient of 0.9996, and the limit of quantification was 3.03 ng/mL. The intra- and inter-day precision was less than 15%. At low, middle and high concentrations, the recovery, the matrix effect and the accuracy was in the range of 76.06%-95.25%, 93.67%-104.19% and 95.20%-99.96% respectively. The method was applied for the pharmacokinetics study of MP tartrate tablets (50 mg). The AUC(0-t), T(max) and C(max) were respectively 919.88 ± 195.67 μg/L·h, 0.96 ± 0.33 h, 349.12 ± 78.04 ng/mL.

The stimulated emission cross-section of Nd:GGG crystal in 938 nm transition was measured by the amplifier approach. It is 2.3 x 10(-20) cm(2). A quasi-continuous-wave diode pumped, actively Q-switched Nd:GGG laser operating at 938 nm was demonstrated. Pumped by laser diodes with 900 W peak power and 300 mu s pulse duration, it generated 168 mJ energy in long pulse mode. The slope efficiency was 36%. Q-switched by a KD*P Pockels cell, 41 mJ output pulse energy was obtained. The pulse duration and peak power were 120 ns and 340 kW, respectively. The optical to optical efficiency was 7%. (C) 2011 Elsevier Ltd. All rights reserved.

Cubic ZnSnO 3 nanocages, a geometrical cube-shape with a hierarchical structure composed of small nanoparticles as secondary units, are successfully synthesized via a facile hydrothermal process. These ZnSnO 3 nanocages have hollow interiors and good-permeation surfaces, and are used for detecting different gases such as ethanol (C 2 H 5 OH), formaldehyde (HCHO), and hydrogen sulfide (H 2 S). These ZnSnO 3 nanocages show good response, selectivity, response and recovery characteristics to H 2 S. It is found that ZnSnO 3 nanocages have a response of 17.6–50 ppm H 2 S at the optimal operating temperature of 310 °C and the response time is shorter than 20 s.

Carbon-supported platinum-decorated nickel nanoparticles (denoted as Pt-Ni/C) with intimate contact of Pt and Ni are prepared by a galvanic displacement reaction between Ni/C nanoparticles and PtCl 6 2− in aqueous solution. It demonstrates a higher mass activity and stability to methanol oxidation reaction than conventional Pt/C and PtRu/C catalysts by a rotating disk electrode in acid solution, which could be attributed to the modified electronic structure of the Pt-Ni/C nanoparticles.

2-[[(1,1-dimethylethyl)oxidoimino]methyl]-3,5,6-trimethylpyrazine (TBN), a novel nitrone derivative of tetramethylpyrazine (TMP), was found to be a potent candidate compound for ischemic stroke treatment. It is currently in preclinical development as a stroke therapeutic. To study its pharmacokinetic characteristics, a simple and rapid HPLC-UV method was developed and validated to quantitatively determine TBN concentration in rat plasma. A Purospher C(18) column (150 × 4.6 mm, 5 μm) was used for analysis with a mobile phase containing methanol-potassium dihydrogen phosphate buffer solution (50 mM, pH 3.0) (45:55, v/v) and UV detection at 295 nm. The pharmacokinetic study was conducted in Sprague-Dawley rats by intravenous (i.v. 40, 80, and 160 mg/kg) and intragastric (i.g. 80 mg/kg) administration. The concentration-time profiles of TBN in plasma fitted a two-compartment model for both administration routes. The elimination half-life (T (1/2) (β)) of i.v. administration ranged from 134 to 225 min for low, middle and high dosage, and the area under the concentration-time curve from zero to infinity (AUC((0-∞))) ranged from 7,954 to 49,804 μg min/mL. Compared with the parent compound TMP, TBN showed a longer T (1/2) (β) (TBN 134.52 min, TMP 91.85 min) and a higher AUC((0-∞)) (TBN 22,687.84 μg min/mL, TMP 7,287.98 μg min/mL) after the same dosage of intravenous administration (80 mg/kg). The intragastric administration of TBN had a peak time of 21.65 min, C (max) of 41.71 μg/mL, and k (a) of 0.19 min(-1). And the absolute bioavailability was 36.02%.

Macropore formation by photoelectrochemical (PEC) etching of N-type crystalline Si under front side illumination has been investigated. We report on two important parameters that influence the pore morphology: the applied anodic bias and the spectral distribution of the illumination source. On (100) c - Si, the pore morphology changes from a round shape at low bias (0 V/NHE) to a conical shape at high bias (2 V/NHE). In the latter case we show that, by adjusting the spectrum of the white light source with longpass filters of different cut-on wavelengths, we can control the cone angle of the pores from 50° with white light to 10° with infrared light. Optical measurements indicate that macropores formed with a narrow cone angle (20°) could be of interest for Si solar cell texturization since they result in a very low reflectivity (2.6% at 800 nm) and in an efficient light trapping.

By using the extended point-matching method, coupled mode theory, and electro-optic modulation theory, design and optimization are carried out for a polymer shielded push–pull directional coupler electro-optic switch. A novel technique and the relative formulas are presented for analyzing the influences of the skin-effect on the microwave characteristic parameters and the switching performances. Simulation results show that the voltages of the cross- and bar-states are 0 and ±2.93 V, respectively, and the coupling length is 4.139 mm. Considering the influences of the skin-effect, the cutoff switching frequency is 172 GHz, the insertion loss is in the range of 1.920–1.975 dB, the crosstalk is less than −20 dB, and the switching time is 31.18–31.40 ps within the range of the switching frequency from 0.72 to 172 GHz. The designed switch exhibits superior characteristics including good impedance match, low switching voltage, and high cutoff switching frequency.

By using the coupled mode theory, electro-optic modulation theory, conformal transforming method and image method, the structure is designed, the parameters are optimized, and the characteristics are analyzed for a polymer directional coupler electro-optic switch with two-section reversed electrodes. Simulation shows that the designed device exhibits excellent switching functions. Under the operation wavelength of 1550 nm, the electro-optic coupling region length is 4751 μm, the cross-state and bar-state voltages are about 1.22 and 2.65 V, and the insertion loss and crosstalk are less than 2.21 and −30 dB, respectively. By slightly adjusting the state voltages, the blight of the fabrication errors on the switching characteristics can be easily eliminated. The calculation results of the presented technique are in good agreement with those of the beam propagation method (BPM).

The Dongsheng sandstone-type uranium deposit is one of the large-sized sandstone-type uranium deposits discovered in the northern part of the Ordos Basin of China in recent years. Geochemical characteristics of the Dongsheng uranium deposit are significantly different from those of the typical interlayered oxidized sandstone-type uranium ore deposits in the region of Middle Asia. Fluid inclusion studies of the uranium deposit showed that the uranium ore-forming temperatures are within the range of 150–160°C. Their 3He/4He ratios are within the range of 0.02–1.00 R/Ra, about 5–40 times those of the crust. Their 40Ar/36Ar ratios vary from 584 to 1243, much higher than the values of atmospheric argon. The δ18OH2O and δD values of fluid inclusions from the uranium deposit are −3.0‰–−8.75‰ and −55.8‰–−71.3‰, respectively, reflecting the characteristics of of meteoric water and magmatic water. The δ18OH2O and δD values of kaolinite layer at the bottom of the uranium ore deposit are 6.1‰ and −77‰, respectively, showing the characteristics of magmatic water. The δ13CV-PDB and δ18OH2O values of calcite veins in uranium ores are −8.0‰ and 5.76‰, respectively, showing the characteristics of mantle source. Geochemical characteristics of fluid inclusions indicated that the ore-formation fluid for the Dongsheng uranium deposit was a mixed fluid of meteoric water and deep-source fluid from the crust. It was proposed that the Jurassic-Cretaceous U-rich metamorphic rocks and granites widespread in the northern uplift area of the Ordos Basin had been weathered and denudated and the ore-forming elements, mainly uranium, were transported by meteoric waters to the Dongsheng region, where uranium ores were formed. Tectonothermal events and magmatic activities in the Ordos Basin during the Mesozoic made fluids in the deep interior and oil/gas at shallow levels upwarp along the fault zone and activated fractures, filling into U-bearing clastic sandstones, thus providing necessary energy for the formation of uranium ores.

The stacking configuration in few-layer two-dimensional (2D) materials results in different structural symmetries and layer-to-layer interactions, and hence it provides a very useful parameter for tuning their electronic properties. For example, ABA-stacking trilayer graphene remains semimetallic similar to that of monolayer, while ABC-stacking is predicted to be a tunable band gap semiconductor under an external electric field. Such stacking dependence resulting from many-body interactions has recently been the focus of intense research activities. Here we demonstrate that few-layer MoS2 samples grown by chemical vapor deposition with different stacking configurations (AA, AB for bilayer; AAB, ABB, ABA, AAA for trilayer) exhibit distinct coupling phenomena in both photoluminescence and Raman spectra. By means of ultralow-frequency (ULF) Raman spectroscopy, we demonstrate that the evolution of interlayer interaction with various stacking configurations correlates strongly with layer-breathing mode (LBM) vibrations. Our ab initio calculations reveal that the layer-dependent properties arise from both the spin-orbit coupling (SOC) and interlayer coupling in different structural symmetries. Such detailed understanding provides useful guidance for future spintronics fabrication using various stacked few-layer MoS2 blocks.

Corrigendum: Optoelectronic crystal of artificial atoms in strain-textured molybdenum disulphide

The isolation of the two-dimensional semiconductor molybdenum disulphide introduced a new optically active material possessing a band gap that can be facilely tuned via elastic strain. As an atomically thin membrane with exceptional strength, monolayer molybdenum disulphide subjected to biaxial strain can embed wide band gap variations overlapping the visible light spectrum, with calculations showing the modified electronic potential emanating from point-induced tensile strain perturbations mimics the Coulomb potential in a mesoscopic atom. Here we realize and confirm this ‘artificial atom’ concept via capillary-pressure-induced nanoindentation of monolayer molybdenum disulphide from a tailored nanopattern, and demonstrate that a synthetic superlattice of these building blocks forms an optoelectronic crystal capable of broadband light absorption and efficient funnelling of photogenerated excitons to points of maximum strain at the artificial-atom nuclei. Such two-dimensional semiconductors with spatially textured band gaps represent a new class of materials, which may find applications in next-generation optoelectronics or photovoltaics., Samsung Advanced Institute of Technology (2013 Global Research Outreach Program Award IC2012-1318), National Science Foundation (U.S.) (CBET-1240696), National Science Foundation (U.S.) (DMR-1120901)

Recently, anisotropic 2D materials, such as black phosphorus and rhenium disulfides (ReS2 ), have attracted a lot attention because of their unique applications on electronics and optoelectronics. In this work, the direct growth of high-quality ReS2 atomic layers and nanoribbons has been demonstrated by using chemical vapor deposition (CVD) method. A possible growth mechanism is proposed according to the controlled experiments. The CVD ReS2-based filed-effect transistors (FETs) show n-type semiconducting behavior with a current on/off ratio of ≈10(6) and a charge carrier mobility of ≈9.3 cm(2) Vs(-1). These results suggested that the quality of CVD grown ReS2 is comparable to mechanically exfoliated ReS2, which is also further supported by atomic force microscopy imaging, high-resolution transmission electron microscopy imaging and thickness-dependent Raman spectra. The study here indicates that CVD grown ReS2 may pave the way for the large-scale fabrication of ReS2-based high-performance optoelectronic devices, such as anisotropic FETs and polarization detection.

Van der Waals (vdW) solids, as a new type of artificial materials that consist of alternating layers bonded by weak interactions, have shed light on fascinating optoelectronic device concepts. As a result, a large variety of vdW devices have been engineered via layer-by-layer stacking of two-dimensional materials, although shadowed by the difficulties of fabrication. Alternatively, direct growth of vdW solids has proven as a scalable and swift way, highlighted by the successful synthesis of graphene/h-BN and transition metal dichalcogenides (TMDs) vertical heterostructures from controlled vapor deposition. Here, we realize high-quality organic and inorganic vdW solids, using methylammonium lead halide (CH3NH3PbI3) as the organic part (organic perovskite) and 2D inorganic monolayers as counterparts. By stacking on various 2D monolayers, the vdW solids behave dramatically different in light emission. Our studies demonstrate that h-BN monolayer is a great complement to organic perovskite for preserving its original optical properties. As a result, organic/h-BN vdW solid arrays are patterned for red light emitting. This work paves the way for designing unprecedented vdW solids with great potential for a wide spectrum of applications in optoelectronics.

Novel formulas of the transfer functions and the amplitude coupling ratios are presented for characteristic analysis and parameter optimisation of a 1×16 microring resonant wavelength multi-/demultiplexer with triple vertically coupled rings in every filter element. This device can demultiplex 16 different wavelengths around the central wavelength of 1550 nm with the wavelength spacing of 0.8 nm. Simulation shows that by properly selecting the amplitude coupling ratios, the box-like flat spectral response can be formed and the crosstalk can be greatly reduced. The simulated results of the presented device are as follows: the 3 dB bandwidth is about 0.23 nm, the insertion loss is