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Oxygen reduction reaction (ORR) catalyst supported by hybrid composite materials is prepared by well-mixing carbon black (CB) with Pt-loaded reduced graphene oxide (RGO). With the insertion of CB particles between RGO sheets, stacking of RGO can be effectively prevented, promoting diffusion of oxygen molecules through the RGO sheets and enhancing the ORR electrocatalytic activity. The accelerated durability test (ADT) demonstrates that the hybrid supporting material can dramatically enhance the durability of the catalyst and retain the electrochemical surface area (ECSA) of Pt: the final ECSA of the Pt nanocrystal on the hybrid support after 20 000 ADT cycles is retained at95%, much higher than the commercially available catalyst. We suggest that the unique 2D profile of the RGO functions as a barrier, preventing leaching of Pt into the electrolyte, and the CB in the vicinity acts as active sites to recapture/renucleate the dissolved Pt species. We furthermore demonstrate that the working mechanism can be applied to the commercial Pt/C product to greatly enhance its durability.

Simple and efficient method for N-Boc protection of amines using PEG-400 as an ecofriendly reaction medium at room temperature is described. Various aromatic, heteroaromatic, and aliphatic amines were converted to the corresponding N-tert-butyl-carbamates in good to excellent yields in short times.

N-Cbz-protected amino acids reacted with various arylamines in the presence of methanesulfonyl chloride and N-methylimidazole in dichloromethane to give the corresponding arylamides in high yields. No obvious racemization was observed under the mild conditions.

Obesity-induced inflammation plays a pivotal role in the pathogenesis of insulin resistance and type 2 diabetes. Xanthoangelol (XA) and 4-hydroxyderrcin (4-HD), phytochemicals extracted from Angelica keiskei, have been reported to possess various biological properties. Whether XA and 4-HD alleviate obesity-induced inflammation and inflammation-induced adipocyte dysfunction was investigated.For the in vitro study, a co-culture system composed of macrophages and adipocytes and macrophages stimulated with conditioned medium derived from fully differentiated adipocytes was conducted. For the in vivo study, mice were fed a high-fat diet supplemented with XA for 14 weeks.XA and 4-HD suppressed inflammatory factors in co-culture system. Moreover, treatment of RAW macrophages with XA and 4-HD moderated the suppression of uncoupling protein 1 promoter activity and gene expression in C3H10T1/2 adipocytes, which was induced by conditioned medium derived from LPS-stimulated RAW macrophages. Also, XA and 4-HD inhibited c-Jun N-terminal kinase phosphorylation, nuclear factor-κB, and activator protein 1, the last two being transcription activators in activated macrophages. Furthermore, in mice fed the high-fat diet, XA reduced inflammatory factors within the white adipose tissue.These results suggest that XA and 4-HD might be promising phytochemicals to suppress obesity-induced inflammation and inflammation-induced adipocyte dysfunction.

We propose a new approach to hedge fund performance evaluation by using ETF returns as proxies for tradeable risk factors in the return attribution factor model framework. The model dynamically identifies specific risk factor exposures out of the entire universe of available ETFs, comprehensively spanning the space of potential risk factors. This approach results in more informative estimates of both alpha and beta coefficients for out-of-sample performance compared with other widely used hedge fund factor models. The portfolios of top alpha hedge funds selected by our model generate statistically significant out-of-sample performance that is substantially better compared to portfolios selected by other models. In addition, the hedge fund mimicking portfolios constructed as beta-weighted factor portfolios exhibit substantially higher out-of-sample correlations with underlying hedge funds than portfolios formed using alternative models.

Piceatannol (PIC), a natural analog of resveratrol (RES), is a phytochemical found in passion fruit seeds. To clarify the effects of PIC on obesity‐induced inflammation in adipose tissue, we investigated the anti‐inflammatory activity of PIC‐related compounds (PIC, RES, and metabolites from PIC) in culture models of obese adipose tissue. Lipopolysaccharide (LPS) and conditioned medium from 3T3‐L1 adipocytes (3T3‐L1‐CM) enhanced proinflammatory gene expression and synthesis of nitric oxide (NO), tumor necrosis factor‐α (TNF‐α), and interleukin‐6 (IL‐6) in RAW264.7 macrophages. Although each compound inhibited the mRNA expression of iNOS (inducible NO synthase), TNF‐α, and IL‐6, PIC potently inhibited them, and 30 μmol/L PIC suppressed the LPS‐ and 3T3‐L1‐CM‐induced mRNA expression of iNOS (70.4% and 69.2% suppression, respectively), TNF‐α (42.6% and 47.0% suppression), and IL‐6 (27.3% and 42.1% suppression). PIC also significantly suppressed production of NO (80.3% suppression) and inflammatory cytokines (TNF‐α; 33.7% suppression, IL‐6; 66.5% suppression). Furthermore, PIC was found to rescue the uncoupling protein 1 mRNA expression induced by isoproterenol in 10T1/2 adipocytes, which was suppressed by LPS‐activated macrophages. These results suggest that PIC may attenuate the pathologic inflammation triggered by adipose tissues.

Adipocyte differentiation plays a pivotal role in maintaining the production of small-size adipocytes with insulin sensitivity, and impaired adipogenesis is implicated in insulin resistance. 4-Hydroxyderricin (4-HD), a phytochemical component of Angelica keiskei, possesses diverse biological properties such as anti-inflammatory, antidiabetic, and antitumor. In the present study, we investigated the effects of 4-HD on adipocyte differentiation. 4-HD promoted lipid accumulation in 3T3-L1 cells, upregulated both peroxisome proliferator-activated receptor (PPAR)-γ mRNA and protein expression, and acted as a ligand for PPARγ in the luciferase assay. Moreover, 4-HD increased the mRNA and protein expression levels of adiponectin. Additionally, it promoted insulin-dependent glucose uptake into 3T3-L1 adipocytes and increased Akt phosphorylation and glucose transporter (GLUT) 4 mRNA expression. In summary, these findings suggest that 4-HD, which promoted adipogenesis and insulin sensitivity in 3T3-L1 cells, might be a phytochemical with potent insulin-sensitizing effects.

A Cu2O nanoparticle catalyzed borylation of activated and unactivated alkyl bromides is developed, using bis(pinacolato)diboron as a boron source. To the best of our knowledge this is the first report of a heterogeneous Cu2O nanocatalyst applied in the direct synthesis of primary and secondary alkylboronic esters. Our catalytic system features mild reaction conditions, high yield (nearly 100%) and the absence of ligands which otherwise are essential in homogenous catalysis.

We report a highly efficient photocatalyst comprised of Cu7S4@Pd heteronanostructures with plasmonic absorption in the near-infrared (NIR)-range. Our results indicated that the strong NIR plasmonic absorption of Cu7S4@Pd facilitated hot carrier transfer from Cu7S4 to Pd, which subsequently promoted the catalytic reactions on Pd metallic surface. We confirmed such enhancement mechanism could effectively boost the sunlight utilization in a wide range of photocatalytic reactions, including the Suzuki coupling reaction, hydrogenation of nitrobenzene, and oxidation of benzyl alcohol. Even under irradiation at 1500 nm with low power density (0.45 W/cm(2)), these heteronanostructures demonstrated excellent catalytic activities. Under solar illumination with power density as low as 40 mW/cm(2), nearly 80-100% of conversion was achieved within 2 h for all three types of organic reactions. Furthermore, recycling experiments showed the Cu7S4@Pd were stable and could retain their structures and high activity after five cycles. The reported synthetic protocol can be easily extended to other Cu7S4@M (M = Pt, Ag, Au) catalysts, offering a new solution to design and fabricate highly effective photocatalysts with broad material choices for efficient conversion of solar energy to chemical energy in an environmentally friendly manner.

Titanium oxide (TiO2) represents one of most widely studied materials for photoelectrochemical (PEC) water splitting but is severely limited by its poor efficiency in the visible light range. Here, we report a significant enhancement of visible light photoactivity in nitrogen-implanted TiO2 (N-TiO2) nanowire arrays. Our systematic studies show that a post-implantation thermal annealing treatment can selectively enrich the substitutional nitrogen dopants, which is essential for activating the nitrogen implanted TiO2 to achieve greatly enhanced visible light photoactivity. An incident photon to electron conversion efficiency (IPCE) of ∼10% is achieved at 450 nm in N-TiO2 without any other cocatalyst, far exceeding that in pristine TiO2 nanowires (∼0.2%). The integration of oxygen evolution reaction (OER) cocatalyst with N-TiO2 can further increase the IPCE at 450 nm to ∼17% and deliver an unprecedented overall photocurrent density of 1.9 mA/cm(2), by integrating the IPCE spectrum with standard AM 1.5G solar spectrum. Systematic photoelectrochemical and electrochemical studies demonstrated that the enhanced PEC performance can be attributed to the significantly improved visible light absorption and more efficient charge separation. Our studies demonstrate the implantation approach can be used to reliably dope TiO2 to achieve the best performed N-TiO2 photoelectrodes to date and may be extended to fundamentally modify other semiconductor materials for PEC water splitting.

Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism.

The reductive elimination of [Cp*Ir(CO)(C≡CPh)2] to [Cp*Ir(CO)(PhC≡C-C≡CPh)] has been investigated. This reaction proceeds at an accelerated rates in protic solvents, and the reaction pathway has been examined computationally and experimentally. The effects of substitution at the phenyl ring and of the ancillary ligand have also been examined. The reactivity of both bis(alkynyl) complexes [Cp*Ir(CO)(C≡CAr)2] and diyne complexes [Cp*Ir(CO)(ArC≡C-C≡CAr)] have also been investigated. The diyne complex reacted with two electron-donors L to form the 4-membered metallacycles [Cp*Ir(L){C(C≡CAr)=C(Ar)C=O}] by an intramolecular cycloaddition reaction. The kinetics of the reaction has been measured and the reaction pathway studied computationally. The photochemical reaction of the diyne complex with 3-hexyne afforded an allyl complex, its reaction with phenylacetylene afforded the unstable iridapentadiene species [Cp*Ir(CO){CH=C(Ph)C(Ph)=C(CCPh)}], and acid-catalysed hydrolysis yielded the iridacyclopentenone [Cp*Ir(CO){C(Ph)=CHC(=O)CHPh}]. The bisalkynyl complexes [Cp*Ir(L)(C≡CAr)2] were found to undergo acid-catalysed aerobic oxidation to form the iridaindenes [Cp*Ir(L){C6H4-1,2-CH=CC(=O)C(=O)Ar}]. They also undergo an Arbuzov-type reaction with P(OMe)3 in the presence of CH3COOH to give the iridacyclic phosphates [Cp*Ir(L){C(Ar)=C[P(=O)(OMe)2]C=CHAr}]. Reaction pathways for both reactions have been proposed. DOCTOR OF PHILOSOPHY (SPMS)

cope Recent reports indicate that gut microbiota and their metabolite may regulate inflammatory conditions, including the chronic inflammation of obese adipose tissues, in the host. In this study, we investigated whether specific synthesized fatty acids, identical to the metabolites generated by gut microbiota, act as anti-inflammatory factors in inflammation-induced obesity. Methods and results We first used lipopolysaccharide-stimulated RAW 264.7 macrophages to examine the anti-inflammatory effect of fatty acids synthesized to resemble representative polyunsaturated fatty acid metabolites from gut microbiota. Fatty acids containing an enone structure showed the most potent anti-inflammatory activity. Enone fatty acids also displayed anti-inflammatory effects on macrophages co-cultured with hypertrophied 3T3-L1 or immortalized primary adipocytes; and macrophages stimulated with 3T3-L1 adipocyte conditioned medium. Consistently, the beneficial outcome was revealed in the case of LPS- and obesity-induced inflammatory cytokine stimulation in ex vivo adipose tissues. Furthermore, these fatty acids recovered the suppression of β-adrenergic receptor-stimulated uncoupling protein 1 expression and secretion of adiponectin in C3H10T1/2 and 3T3-L1 adipocytes respectively, under inflammatory conditions, suggesting that enone fatty acids can ameliorate dysfunctions of adipocytes induced by inflammation. Conclusion These findings indicate that synthesized enone fatty acids show potent anti-inflammatory effects, leading to the improvement of inflammation-induced dysfunctions in adipocytes. This article is protected by copyright. All rights reserved

An ECG recording front-end with a continuous- time asynchronous level-crossing analog-to-digital converter (LC-ADC) is proposed. The system is a voltage and current mixed-mode system, which comprises a low noise amplifier (LNA), a programmable voltage-to-current converter (PVCC) as a programmable gain amplifier (PGA) and an LC-ADC with calibration DACs and an RC oscillator. The LNA shows an input referred noise of 3.77 μVrms over 0.06 Hz-950 Hz bandwidth. The total harmonic distortion (THD) of the LNA is 0.15% for a 10 mVPP input. The ECG front-end consumes 8.49 μW from a 1 V supply and achieves an ENOB up to 8 bits. The core area of the proposed front-end is 690 ×710 μm2, fabricated in a 0.18 μm CMOS technology.

We argue that only hedge funds whose returns are driven by beta management of exposures to latent risk factors could be successfully replicated. We develop a methodology for creating a portfolio of ETFs that replicates risk factor exposures taken by successful beta active cloneable hedge funds. The methodology allows any investor to access active factor strategies employed by hedge funds. It could be interpreted as cloning beta exposures of the best beta active hedge funds, delivering outstanding long-term risk-adjusted performance. The active factor ETF portfolio only requires annual rebalancing, and is constructed with a transparent algorithmic approach, which conforms to a definition of a smart beta strategy.

Fully spanning the space of potential risk factors with tradable liquid portfolios is paramount in the context of a risk-based factor model. We develop a factor selection methodology of spanning the space of hedge fund risk factors with all available exchange traded funds (ETFs). We demonstrate the efficacy of the methodology with out-of-sample hedge fund return replication, and find that the replication accuracy increases with the number of ETFs available. This is consistent with our interpretation of ETF returns as proxies to alternative risk factors driving hedge fund returns. We further consider portfolios of “cloneable” and “non-cloneable” hedge funds, defined as top and bottom in-sample R2 matches. We find superior risk-adjusted performance for “non-cloneable” funds, while “cloneable” funds fail to deliver significantly positive risk-adjusted performance. Our methodology provides value in both identifying skilled managers of “non-cloneable” hedge funds, as well as successfully replicating out-of-sample returns that are due to alternative risk exposures of “cloneable” hedge funds, thus providing a transparent and liquid alternative to investors who may find these return patterns attractive.

We propose a low-power asynchronous level-crossing analog-to-digital converter (LC-ADC) for use in a biomedical readout system. A comparator with programmable offset and a low-power single-bit digital-to-analog converter (DAC) are proposed to separate the comparison windows and fix the common-mode voltage of the comparator. Implemented in a 0.18 μm CMOS technology, the proposed LC-ADC uses a chip area of 220×230 μm2. Operating from a supply voltage of 0.8 V, the ADC input range can exceed the power supply voltage. It consumes 0.32 - 0.84 μW from 5 Hz to 5.1 kHz with an ENOB of 7.8.

We report a facile synthetic strategy to single-crystalline PtPd nanocrystals with controllable shapes and tunable compositions. In the developed synthesis, the molar ratio of the starting precursors determines the composition in the final PtPd nanocrystals, while the halides function as the shape-directing agent to induce the formation of PtPd nanocrystals with cubic or octahedral/tetrahedral morphology. These obtained PtPd nanocrystals exhibit high activity in the hydrogenation of nitrobenzene, and their performance is highly shape- and composition-dependent with Pt in ∼50% showing the optimum activity and the {100}-facet-enclosed PtPd nanocrystals demonstrating a higher activity than the {111}-facet-bounded PtPd nanocrystals.

Simple and efficient method for N-Boc protection of amines using PEG-400 as an ecofriendly reaction medium at room temperature is described. Various aromatic, heteroaromatic, and aliphatic amines were converted to the corresponding N-tert-butyl-carbamates in good to excellent yields in short times.

This paper presents a novel continuous-time level- crossing analog-to-digital converter (LC-ADC) targeted at biomedical signal sensing applications. The conventional digital- to-analog converter (DAC) is replaced by a charge sharing block, leading to lower power consumption, less design complexity and more flexibility for various resolution applications. Designed to be implemented in 90 nm CMOS technology, the proposed ADC achieves a maximum SNDR of 51.4dB and consumes a minimum power of 538nW from a dual supply of 0.5V and 0.7V. I. INTRODUCTION Analog-to-digital converters are indispensable building blocks of wearable and implantable biomedical data acquisition systems. Conventional ADCs utilize uniform sampling, which is based on periodically sampling the magnitude of the signal. Among those ADC structures, the successive approximation register (SAR) ADC is the most popular one in low power applications, because the only analog circuitry within it is a comparator, while the rest of the circuits are digital and thus easily scale down with technology. Basically, SAR-ADCs periodically sample the input and use binary search algorithms to successively approximate the sampled input signal from the most-significant bit (MSB) to the least-significant bit (LSB). However, SAR-ADCs are not that power-efficient for biomedical signal recording, as most of the signal components have small signal magnitudes, while the SAR-ADC repeats the same searching procedure from MSB to LSB for each input sample even when the input signal varies slowly.

An ultra low-voltage and low-power CMOS voltage reference was proposed in this paper. Subthreshold and body effect techniques are used to achieve temperature compensation. No resistor and BJT are used in this structure. The proposed circuit has been simulated with Charted 0.18-µm standard CMOS process. The simulated results show that the voltage reference can operate with sub−0.6V supply and total supply current is 60nA at 0.58V supply at room temperature. The temperature coefficient of the output voltage is 4.6ppm/°C, in a range from −40°C to 85°C.

This paper presents a new simple curvature-compensated CMOS voltage reference, which utilizes different temperature-dependent resistors, peaking current mirror circuit and subthreshold technology. Designed in a standard 0.5-µm CMOS technology, the proposed circuit achieves the reference voltage variation of 2.97mV for supply voltage ranging from 1.6 to 5V and 0.6mV for temperature varying from −20 to 80°C. It generates a reference voltage of 416mV and consumes a supply current of 0.86µA at 27°C and less than 1µA at 80°C. The occupied area is 0.037 mm2.

A low voltage MOSFET-only voltage reference using body effect and subthreshold operation is proposed in this paper1. A temperature coefficient of 5 ppm/°C from −55°C to 90 °C is achieved as the combined effects of: 1) a suppression of the temperature dependence of mobility; 2) a piecewise compensation of the temperature dependence of subthreshold slope parameter during the second half of temperature range. The voltage reference is designed in SMIC 0.13µm CMOS process. It is able to operate at power supply voltage down to 760mV and consumes a supply current of less than 1µA at 90°C.