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This letter proposes an effective scheme to improve the error performance of conventional bit-flipping BF algorithms for decoding low-density parity-check codes. The proposed scheme, which is referred to as the multiple-candidates MC scheme, constructs a set of candidates for the starting vector of the iterative decoding procedure. Each candidate vector in the set is generated by randomly flipping several high error probability bits of the original hard-decision vector. Simulation results show that two typical BF algorithms applying the MC scheme achieve noticeable gains over the original BF algorithms with moderate increase in computational cost. Copyright © 2012 John Wiley & Sons, Ltd.

Selective C–H bond activation and functionalization is an invaluable and eco-friendly tool for new chemical bond construction. Recently, great progress has been made in the highly selective ortho- and meta-C–H bond functionalization of arene derivatives. In contrast, the remote para-C–H bond functionalization still remains a challenge. Herein, an oxidation-induced strategy for para-selective C–H bond functionalization of iodobenzenes towards the synthesis of various useful asymmetric diaryl ethers was demonstrated. This strategy not only provides a novel method for para-C–H bond functionalization, but also proposes a general idea for the development of new, highly selective para-C–H functionalization reactions.

Transition metal-catalyzed isocyanide insertion has served as a fundamental and important chemical transformation. Classical isocyanide insertion usually occurs between organohalides and nucleophiles, which normally involves tedious and non-atom-economical prefunctionalization processes. However, oxidative C-H/N-H isocyanide insertion offers an efficient and green alternative. Herein, a nickel-catayzed oxidative C-H/N-H isocyanide insertion of aminoquinoline benzamides has been developed. Different kinds of iminoisoindolinone derivatives could be synthesized in good yields by utilizing Ni(acac)2 as the catalyst. In this transformation, isocyanide serves as an efficient C1 connector, which further inserted into two simple nucleophiles (C-H/N-H), representing an effective way to construct heterocycles.

A new method was demonstrated to overcome the selectivity issue of radical–radical cross-coupling toward the synthesis of asymmetric diaryl thioethers. The preliminary mechanism was revealed by radical-trapping experiments, DFT calculations, and kinetics, etc., indicating that the C–S bond formed through cross-coupling of a thiyl radical and an aryl radical cation. Moreover, the formation of an aryl radical cation instead of the C–H bond cleavage was determined as the rate-limiting step.

A copper-catalyzed and iodide-promoted aerobic C–C bond cleavage/C–N bond formation reaction between ketone and simple amine was developed toward the synthesis of amides, which are useful synthetic intermediates in organic synthesis and important skeletons of biologically active molecules. Notably, the reaction conditions are very mild, and preliminary mechanistic investigations indicate that molecular oxygen might be involved in the C–C bond cleavage process.

A new method was demonstrated to overcome the selectivity issue of radical–radical cross-coupling toward the synthesis of asymmetric diaryl thioethers. The preliminary mechanism was revealed by radical-trapping experiments, DFT calculations, and kinetics, etc., indicating that the C–S bond formed through cross-coupling of a thiyl radical and an aryl radical cation. Moreover, the formation of an aryl radical cation instead of the C–H bond cleavage was determined as the rate-limiting step.

Transition metal-catalyzed isocyanide insertion has served as a fundamental and important chemical transformation. Classical isocyanide insertion usually occurs between organohalides and nucleophiles, which normally involves tedious and non-atom-economical prefunctionalization processes. However, oxidative C-H/N-H isocyanide insertion offers an efficient and green alternative. Herein, a nickel-catayzed oxidative C-H/N-H isocyanide insertion of aminoquinoline benzamides has been developed. Different kinds of iminoisoindolinone derivatives could be synthesized in good yields by utilizing Ni(acac)2 as the catalyst. In this transformation, isocyanide serves as an efficient C1 connector, which further inserted into two simple nucleophiles (C-H/N-H), representing an effective way to construct heterocycles.

Ca10(PO4)6(OH)2 (HAP) and NH4Al(OH)2CO3·H2O (AACHH) whiskers were prepared by a homogeneous precipitation method based on urea hydrolysis reaction. To clarify the growth process of whiskers in the homogeneous system, XRD and SEM results of the products obtained at different reaction time were investigated in detail. A novel observation about budding growth in preparing both whiskers was described. It was indicated that the growth of whiskers went through three stages, which were oversaturation, nucleation, and budding growth. The growth units of whiskers budded from the surfaces of substrates, which were crystallized flakes for HAP preparation and amorphous spherical nuclei for AACHH preparation. Subsequently, the whiskers grew up accompanying with the disappearing substrates. One-dimensional whiskers with fine morphology and large slenderness ratio were finally obtained. Besides, according to the crystal growth and the interface diffusion theories, the effects of the templates and the budding growth mechanism were discussed.

Green-emitting Tb3+-doped Ca-deficient hydroxyapatite phosphor was successfully prepared from natural collophanite. The effects of (Tb+Ca)/P values on the crystal phases and luminescent properties of the prepared products were discussed. XRD results revealed that Ca-deficient hydroxyapatite was a biphase compound of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), and its crystal phase transformed to HA with the increasing values of (Tb+Ca)/P. Photoluminescence measurements showed that the products presented intensely green emission peaking at 545 nm under near-ultraviolet excitation and the luminescent intensity had great correlation with the content ratios of β-TCP to HA. When (Tb+Ca)/P=1.3, the luminescent intensity of Tb3+-doped Ca-deficient hydroxyapatite reached the maximum value, which was much stronger than that of Tb3+-doped HA. These results indicate that Tb3+-doped Ca-deficient hydroxyapatite phosphor is suitable for potential application in white light-emitting diode (LED).

The study is carried out combing with the production practice in Danjiangkou Hongyuan SiC limited. Si3N4 and SiC were prepared successfully from SiC and Silicon power in nitrogen atmosphere at 1425°C and 1375°C sintering temperature by the serial of techniques, such as ingredients, mixing, molding and drying, respectively. In the actual production, silicon powder content and sintering temperature will directly influence the products of the bending strength and thermal shock resistance. By measuring bending strength, porosities, bulk density, XRD and FESEM, the bending strength and thermal shock resistance of samples were studied mainly by changing sintering temperature and silicon powder content. The results show that bending strength and thermal shock resistance of sample which was added 16% Si powder is best. And bending strength and thermal shock resistance of sample of 1425°C sintering temperature is higher than that of 1375°C sintering temperature.

The cordierite porous ceramics were made from kaolinite, talc and α-alumina, formed by pressing and fired at 1200 °C for one hour. Starch was used as pore-forming agent. Physical/chemical properties and microstructure of products were characterized. The results show that samples exhibit relatively high strength, low coefficient of thermal expansion and well-distributed gradient pores. The pores of samples are homogeneous.

the National Natural Science Foundations of China (20772111;20876149;21025206;20832003;20972118;20772093);the “973” Project from the MOST of China (2011CB808600);“the Fundamental Research Funds for the Central Universities”;the Program for New Century Excellent Talents in University (NCET);the Academic Award for Excellent Ph.D. Candidates funded by Ministry of Education of China

Hydroxyapatite (HAP) whiskers were synthesized using urea as the precipitator by a phase transformation method, and their phase transformation process and growth mechanism were investigated. The results showed that with the decomposition of urea and the corresponding increase of pH value of the reaction system, dicalcium phosphate anhydrous (DCPA) and octacalcium phosphate (OCP) were precipitated at pH of 3.3–4.3; then Ca2+ and HPO 4 2 − ions began to be released from DCPA at pH values greater than 4.5. Finally HAP whiskers heterogeneously nucleated and grew up into short column crystals along the surface of the OCP flakes. In the absence of the ionic resources, DCPA gradually dissolved and the OCP flakes transformed into HAP continuously and the short columnar HAP whiskers grew up. The aspect ratio of the HAP whiskers with length of 20–100 μm and diameter of 1–2 μm was about 25. The HRTEM and AFM images showed that HAP whiskers grew along the c-axis direction, the (1 0 0) steps were clearly observed at their heads and the straight step lines instead of helical Frank ones were present on the side face of the (1 0 0) steps. The calculation on the basis of the surface energy of the HAP crystal showed that the growth rate of the (0 0 1) plane was the fastest, the growth rate at the homogeneous twist sites was the second and that at heterogeneous twist sites could be the slowest, which were the main factors finally leading to the preferential growth of HAP whiskers along the c-axis direction as well as the formation of the growth steps.

Consumption of berries has become popular among health-conscious consumers due to the high levels of valuable antioxidants, such as anthocyanins, and phenolic compounds in berries. Four Rabbiteye blueberry cultivars (i.e., Powderblue, Climax, Tifblue, and Woodward) grown organically and conventionally were compared regarding their chemical profiles and antioxidant capacity in terms of total phenolic content (TPC), total anthocyanin content (TAC) and ORAC activity. Regardless of the high TPC, TAC and ORAC in both organically and conventionally grown blueberries, not all the organic berries showed significantly higher TPC, TAC and ORAC than the conventional berries. The chemical profiles (i.e., the free phenolic compounds and anthocyanins) were determined with aid of HPLC-MS, by which 13 individual anthocyanins and seven free phenolics were identified. This study demonstrated the subtle differences of bioactive phytochemicals between the organically and conventionally grown berries.

Using Ca(NO3)2·4H2O, (NH4)2HPO4 and urea as the starting raw materials, hydroxyapatite (HAP) crystals were successfully prepared at low temperature (95 °C) by changing the starting pressure inside the autoclave. The HAP crystals were characterized by XRD, SEM, HRTEM, and FTIR technologies. The XRD patterns indicated that increasing the pressure is helpful to improve the purity of the product and the starting pressure change inside the autoclave has a great effect on the growth of HAP crystal planes. The effect of pressure on the growth of various crystal planes was certified by the analysis of HRTEM micrographs. The SEM images illustrated that HAP crystal morphology changed to long plate-like crystals, hexagonal prism-like crystals, and the crystal flakes from needle-like whiskers when increasing the starting pressure inside the autoclave to 0.5 MPa, 0.9 MPa, 1.1 MPa from 0.11 MPa. The formula (IV) about the growth rate of a-surface and c-surface was presented on the basis of the traditional formula about the growth rate of the polyhedral crystallization and the crystal and the growth unit model. According to the formula (IV), a reasonable interpretation was introduced for pressure effecting on morphologies of HAP crystal.

Apatite-type La9.33(SiO4)6O2 powders have been prepared by urea-nitrates combustion at low temperature. Process parameters of combustion and characteristics of electrolyte were studied and optimized. Gelation time of precursor has been shortened distinctly by introducing an appropriate solvent system. Molar ratio of nitric acid to lanthanum oxide dependence of the nature of the phases has first been characterized. Well-crystallized La9.33(SiO4)6O2 powders with an average size of 30.5 nm were obtained at a calcining temperature as low as 800°C for 12h. Dense ceramic with a relative density of 96% was prepared by sintering the green compact of these nanopowders at 1400°C for 3 h. The sintering body exhibited a high ionic conductivity of 4.38 × 10−3 S/cm at 700°C.

A homogeneous precipitation process based on urea hydrolysis reaction was exploited to synthesize BaMgAl 10 O 17 :Eu 2+ phosphor. The process parameters, such as the dosage of urea, the calcination temperatures and the concentration of Eu 2+ , were refined in light of the characterization of the products. The experimental results revealed that pure and well-crystallized BaMgAl 10 O 17 :Eu 2+ phosphor could be obtained at 1250 °C, a much lower temperature than that for traditional solid-state reaction. The as-prepared phosphor particles were small in grain size, regular in morphology, and uniform in size distribution. Because of the high homogeneity of the process, the as-prepared phosphor exhibited stronger emission intensity and higher thermal stability than the sample prepared by solid-state reaction at 1600 °C.

Silicon carbide (SiC) slurry with a low concentration was prepared, which was milled for 3 hours by mixing SiC powder with a certain amount of polyethylene glycol (PEG), tetramethyl ammonium hydroxide (TMAH), carboxymethyl cellulose sodium (CMC-Na), distilled water, and ethonal. The influence of the pH value on the Zeta potential and the additional components on the dispersion stability of the slurry were analyzed. The influence of various factors on slurry was studied by orthogonal experiment. The results showed that solid content had the greatest influence on viscosity and stability of slurry. After the slurry was coated on the surface of porous SiC ceramics and sintered at high temperature to form a SiC membrane, the micro-structure of SiC membrane and its pore size were characterized. The result showed that the pore size distribution of SiC membrane was narrow, and the average pore diameter was about 1µm. Meanwhile, the resultant grains tend to be round, uniform, single phase. Based on the above, we could know that the slurry has a good membrane-forming properties.

Here we demonstrated that Galectin-3 protein level was frequently up-regulated in colorectal cancer (CRC) cells and tissues. Galectin-3 up-regulation correlated with CRC progression and predicted a shorter overall survival of CRC patients. Galectin-3 overexpression attenuated the chemo-sensitivity of cancer cells, but enhanced the potential invasiveness. To explore the mechanism for Galectin-3 dysregulation, we found that miR-128 level was frequently down-regulated in CRC and negatively correlated with Galectin-3 level. Using bioinformatics analysis and experimental validation, we showed that miR-128 could directly target Galectin-3 to repress its protein level. MiR-128 decrease associated with CRC progression and predicted a worse overall survival of CRC patients. Ectopic miR-128 expression enhanced the chemo-sensitivity of CRC cells in vitro and in vivo, and inhibited the potential invasiveness. Galectin-3 expression impaired the cancer suppressive effects of miR-128. These data highlighted the role of miR-128/Galectin-3 axis in colorectal cancer.

Flame retardant epoxy resins were prepared by a simple mixed method using ammonium aluminum carbonate hydroxy hydrate (AACHH) as a halogen-free flame retardant. The prepared samples were characterized by X-ray diffraction, thermogravimetric and differential scanning calorimetry, scanning electron microscope and limiting oxygen index(LOI) experiments. Effects of AACHH content on LOI of epoxy resins/AACHH composite and flame retardant mechanism were investigated and discussed. Results show that AACHH exhibites excellent flame-retardant properties in epoxy resin(EP). When the content of AACHH was 47.4%, the LOI of EP reached 32.2%. Moreover, the initial and terminal decomposition temperature of EP increased by 48°C and 40 °C, respectively. The flame retarded mechanism of AACHH is due to the synergic flame retardant effects of diluting, cooling, decomposition resisting and obstructing.

Muscadine grapes are important fruits grown in the southeastern United States. They are a good source of anthocyanins, but confirmatory analyses of the structure of individual anthocyanins in muscadine grapes using more advanced instrument are lacking. In this study, the anthocyanins of muscadine grapes were analyzed using HPLC-MS with electrospray ionization. Approximately 90% of the total anthocyanins were 3,5-diglucoside of delphinidin, cyanidin and petunidin; the remaining 10% were 3,5-diglucoside of peonidin and malvidin. There was a significant difference of total anthocyanin content among different cultivars of muscadine grapes with purple-skinned muscadine grapes having significantly higher levels of anthocyanins than bronze-skinned muscadine grapes. The total anthocyanin content in purple-skinned Jumbo and Cowart muscadine was 4.1 and 2.6 mg/g dry weight, respectively, while the total anthocyanin content in bronze-skinned Higgin and Carlos was negligible. The anthocyanins were mainly concentrated in the skin of the grapes. The results of the present study confirmed some of the anthocyanins reported by previous studies and also found one anthocyanin that might be falsely identified by previous studies.

Flowerlike porous B-type carbonated hydroxyapatite (CHAp) microspheres have been synthesized by a novel bubble-template route. Their pore sizes can be well regulated in a wide range from microscale to nanoscale by smartly constructing a kind of CO2 bubble as a template and precisely adjusting the system pressure. We studied the formation of a porous structure of CHAp microspheres and the effect of the system pressure on their morphologies. Most of all, the control of the pressure over the pore sizes of bubble-template porous CHAp microspheres was investigated. The results suggested that the gathering and growth of the CO2 bubbles generated the formation of the porous structure of CHAp microspheres, and along with the increase of system pressure, the surface of the microsphere got denser and the flakes, which assembled the porous structure, became smaller. In addition, with the increased pressure, the average pore sizes of bubble-template CHAp microspheres gradually decreased from microscale to nanoscale. ...

Epidemiologic studies have demonstrated that trans fat intake increases the risk of some chronic diseases. We hypothesize that trans fat intake would increase the risk of cardiovascular disease and type 2 diabetes mellitus by changing the lipid profile in plasma, the secretion of adipokines in adipose tissue, and the insulin sensitivity. Accordingly, the major objective of present study was to investigate the effect of dietary intake of trans fat on lipid profile, insulin sensitivity, and adipokine levels in plasma. Two groups of Wistar rats were fed a diet containing 4.5% trans fat or a control diet containing no trans fat for 16 weeks. Fasting glucose level was monitored every 2 weeks. At the end of feeding experiment, blood, heart, kidney, liver, omental adipose tissue, and semitendinosus muscle were collected. The trans fat content in organs, lipid profile, adipokine, insulin, and glucose levels in plasma were analyzed. The trans fat content in adipose tissue, heart, kidney, liver, and muscle of rats fed trans fat were 169.9, 0.6, 1.2, 1.7, and 2.5 mg/g samples, respectively. The trans fat content in these organs contributed to 15.9%, 1.2%, 2.3%, 4.3%, and 6.1% of the total fat, respectively. The plasma glucose level, insulin level, and insulin sensitivity index were not significantly different between the trans fat and control groups. The results indicated that trans fat intake might not be related to insulin resistance. However, lipid profile and plasma adipokine levels were significantly changed after trans fat feeding. The trans fat fed group showed significantly lower total cholesterol and high-density lipoprotein cholesterol levels than the control group. The decreased high-density lipoprotein cholesterol level may indicate the detrimental effect of trans fat intake on lipid profile. Adiponectin and resistin levels were significantly higher in the trans fat group than the control group. Leptin levels were significantly lower in the trans fat group than the control group. The results indicated that dietary intake of trans fat can significantly change the adipokine levels, but the possible links between adipokine level change caused by trans fat intake and metabolic effects of this change need further investigations.

Collard greens, mustard greens, kale, okra, green onion, butter beans, butter peas, purple hull peas, rutabagas, and eggplant are frequently consumed by African Americans in the southeast United States. Sweet potato greens and purslane are two novel vegetables in this region. The objective of this study was to analyze total phenolics and antioxidant capacity in these indigenous vegetables. The total phenolic content was analyzed using the Folin-Ciocalteu method and ranged from 7.4 to 53.5 mg gallic acid equivalents per gram of dried sample. The antioxidant capacity was analyzed using the radical DPPH(•) scavenging capacity assay and oxygen radical absorbance capacity assay (ORAC). At a concentration of 10.0 mg dried vegetable equivalent/ml, the extract of these vegetables was able to quench 13.2-88.5% DPPH(•) radical in 30 min. The ORAC value ranged from 2.5 to 100.7 µmoles of trolox equivalents per gram of dried sample. The antioxidant capacity of the vegetable samples was highly related to their total phenolic content. The results suggest that these indigenous vegetables consumed by African Americans in the southeastern United States are good sources of the phenolic compounds, which might provide anti-oxidative protection against free radicals in the human body. Consumption of these vegetables might reduce the risk of chronic diseases.

Polyaniline–palladium (PANi-Pd) composite microflakes were synthesized through an immiscible organic/inorganic biphasic system in the presence of poly(ethylene glycol) with molecular weight 4,000 (PEG4000). Aniline was oxidized by PdCl2 in the interface polymerization system, yielding PANi microflakes and elemental Pd nanoparticles simultaneously. Palladium nanoparticles were uniformly dispersed in the microflakes of PANi. The results of FTIR spectra suggested that the oxidation degree of PANi was affected by the initial ratio of metal ions to monomer. The PANi-Pd composites were characterized using X-ray photoelectron spectroscopy and the conductivity of the composite was measured by conventional four-probe method. Scanning and transmission electron microscopy were used to show the morphology of the composites.

Dendritic porous microspheres (DPMs) consisted of octacalcium phosphate (OCP) nucleus and carbonated hydroxyapatite (CHAp) nanoflakes have been synthesized under good control by a template-induced method in a system of constant temperature and pressure. Batch experiments were carried out to investigate the effect of the template Na2EDTA and the organic conditioner glycerol on the dendritic porous morphology. Corresponding morphological evolution process was also researched. The results revealed that the template Na2EDTA altered the natural growth habit of CHAp and induced the first dendritic growth of CHAp nanoflakes on the surface of OCP, and organic conditioner glycerol controlled the second dendritic growth of CHAp nanoflakes on the bigger ones. Higher concentrations of glycerol resulted in higher surface fractal dimension, smaller pore diameter, and greater specific surface area.

A novel solid base catalyst was first prepared through calcining a porous hydroxyapatite loaded with Sr(NO 3 ) 2 at 873 K. The catalyst was characterized by thermal gravimetric analysis, XRD, FT-IR, SEM, BET surface area analysis and the Hammett indicator method. The results indicated that the solid phase reaction of ion-exchange (Ca 5 (PO 4 ) 3 (OH) + SrO → Ca 5− x Sr x (PO 4 ) 3 (OH) + Ca x Sr 1− x O) occurred at 873 K. Moreover, when new phase Ca x Sr 1− x O was dispersed spontaneously onto the surface of the porous hydroxyapatite as a monolayer or submonolayer, it inhibited the decomposition and recrystallization of the porous hydroxyapatite and remained porous morphology of HAP at 873 K. The novel solid base catalyst catalyzed the transesterification of soybean oil to gave the highest conversions of soybean oil with 85%. The catalytic activity of the transesterification could result from the new phase Ca x Sr 1− x O.

Porous A-type carbonated hydroxyapatite (CHAp) spheres were synthesized in the high-pressure hydrothermal system by the template-directed method. The thermal stability of porous A-type CHAp spheres was first studied via calcining in the wide temperature range from 393 K up to 1173 K, analyzed by FT-IR, XRD and SEM. The results showed that the decomposition of porous A-type CHAp spheres went through two stages, owing to the release of the carbonate from the OH − channel and the collapse of apatite-type structure above 973 K, consecutively. The nanoparticles in situ replaced the flakelets of porous CHAp spheres and packed closely into new regular porous Ca 3 (PO 4 ) 2 spheres.

Flowerlike porous carbonated hydroxyapatite (CHAp) spheres were synthesized by the template-directed homogeneous precipitation method. The carbonate content of synthetic CHAp determined by carbon elemental analysis was about 1.50 wt/wt. FT-IR and XRD were employed to analyze the chemical composition of porous CHAp and SEM was used to observe crystal morphology. We studied the effect of the concentration [Ca] and [P] on ingredient and structure, the effect of urea on hierarchical structure, and the effect of the template on morphology. The results suggested that the lower concentration of [Ca] and [P] was advantageous to purity and monodispersity, that the resultant would be prone to a fancy assembly of big flakes into disks at the lower concentration of urea, and that the aperture could be regulated from micrometer size to nanometer size via altering the concentration of the template. This porous material with the hierarchical structure exhibits especial surface characteristics and has a high surface area, showing potential applications. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Porous hydroxyapatite (HA) spheres with high purity of phase and well-controlled pore size were grown by a template-directed method. We studied for the initial concentration of Ca–P how to control the chemical component of the products, and for the concentration of template how to control the aperture and the morphology of porous HA spheres. The experimental results indicated that the lower concentration of Ca–P was prone to pure HA phase and the aperture decreased gradually with the increase of the concentration of template. Correspondingly, the crystallization thermodynamics and template-directed growth kinetics were discussed in details. The solubility isotherms of HA and dicalcium phosphate (DCPD) were calculated based on classical crystallization theories of thermodynamics. The results suggested that there was a critical concentration of P = 0.048 M in the case of Ca:P=5:3 and thus DCPD could be avoided only when P ⩽ 0.048 M in this given reaction system. Kinetic analysis of HA crystal growth revealed that the template depressed the interfacial potential energy E , then enhanced the roughness on the surface of crystal nucleus and directed HA crystal to selectively grow along the [0 0 0 1] direction, and consequently governed the aperture of porous HA spheres. The experimental results were in agreement with the theoretical analysis.

The phenolic composition of vegetables commonly consumed by African Americans in the southeast United States was analyzed with HPLC–MS. The vegetable samples included collard greens, mustard greens, kale, okra, sweet potato greens, green onion, butter beans, butter peas, purple hull peas, rutabagas, eggplant, and purslane. Five compounds out of total 29 peaks detected from the 12 samples – caffeic acid, ferulic acid, quercetin, kaempferol, and isorhamnetin – were identified. No gallic acid, p -coumaric acid, myricetin, luteolin, apigenin, hesperetin, naringenin, or flavanols was detected. The major flavonoids were isorhamnetin, quercetin and kaempferol. Isorhamnetin was found in kale, mustard greens, and purslane. The content ranged from 2.8 to 23.6 mg/100 g fresh edible part. Quercetin was found in collard greens, mustard greens, kale, okra, sweet potato greens, purple hull peas, and purslane. The content ranged from 1.3 to 31.8 mg/100 g with the highest content in kale and lowest content in purslane. Kaempferol was found in collard greens, mustard greens, kale, sweet potato greens, green onion, and purslane. The content ranged from 1.1 to 90.5 mg/100 g. Caffeic acid was only found in sweet potato greens. Ferulic acid was found in collard greens, mustard greens, kale, okra, purple hull peas, and purslane. Although some peaks were found in eggplant, butter beans, butter peas and rutabagas, these peaks were not identified due to lack of reference compound and no flavonoid or phenolic acid was quantified in these samples. The results suggest that these indigenous vegetables among African Americans are good sources of the phenolic compounds, which can be useful for the prevention of cardiovascular and other chronic diseases.

The title reaction does not require any transition-metal and applies molecular oxygen as the sole oxidant.

A new copper-catalyzed reaction toward the synthesis of pyrazine compounds is demonstrated., Copper-catalyzed aerobic oxidative C–H/N–H coupling between simple ketones and diamines was developed toward the synthesis of a variety of pyrazines. Various substituted ketones were compatible for this transformation. Preliminary mechanistic investigations indicated that radical species were involved. X-ray absorption fine structure experiments elucidated that the Cu(II) species 5 coordinated by two N atoms at a distance of 2.04 Å and two O atoms at a shorter distance of 1.98 Å was a reactive one for this aerobic oxidative coupling reaction. Density functional theory calculations suggested that the intramolecular coupling of cationic radicals was favorable in this transformation.

Hydroxyapatite crystal was prepared by homogeneous co-precipitation method using a mixture of Calcium nitrate and diammonium phosphate as raw materials and carbamide as the buffering agent. To analyzed the influence of temperature on hydroxyapatite crystal morphology, the phase composition, crystal morphology and growth orientation were characterized by X-ray diffraction, scanning electron microscope and infrared spectrum respectively. The results show that when the reaction temperature increase from 70 °C to 95 °C, the phases composition of crystal transform from the two phases of tricalcium phosphate and eight calcium phosphate to hydroxyapatite single crystal; the morphology of the hydroxyapatite crystals transforms from nodular whisker to perfectly and compactly acicular whisker.

In this paper, we summarize the progress in the aspect of increasing field of view in adaptive optics. We present the isoplanatic challenge and the limits of conventional adaptive optics. Moreover, we briefly list the development of tomography and researches on the error of tomography in theory and experiment with the goal of reducing the limits imposed by anisoplanatism on conventional adaptive optics.

Agricultural byproducts are a major source of biomass for biofuel/bioenergy conversion. The southeastern U.S. produces a great amount of nutshells from pecan, walnut, and peanut processing. In this study, walnut shells were selected as a representative agricultural byproduct, and a hydrothermal process catalyzed by both bases and acid was applied to convert the walnut shells into liquefied organic compounds. Conversion rate, major organic products, and their distribution were measured under different concentration of bases (0−1.0 M) and reaction temperature (200−300 °C, corresponding to a pressure range of 1.5−8.6 MPa). An increase in base concentration (KOH and Na2CO3 ) or reaction temperature generally resulted in higher conversation rates and was more favorable to the generation of organic compounds of lower molecular weights. HCl as a catalyst promoted the generation of levulinic acid, but the conversion rates were very low. Major compounds from hydrothermal process catalyzed by bases were phenol deri...

The study was aimed to evaluate a simplified gas chromatography method based on the AOAC method 996.06 to analyze the trans fat content in food samples. The gas chromatograph was equipped with mass spectrometer and Alltech AT ™ -Silar-90 capillary column. Ten kinds of the trans fatty acid standard were separated completely from the cis standard and the chemical composition of the peaks was verified by using the mass spectrum. Under the optimized conditions, the recovery rate for triheptadecanoin was 99.0%, the correlation coefficients of trans fatty acid calibration curve was 0.9998 or higher. It demonstrated that the methylation and hexane extraction procedures used in this method was effective and the result was consistent. The major fatty acids found in the shortening sample were 16:0, 18:0, trans -18:1, cis -18:1, cis -18:2, and cis -18:3. The total trans fat content in the sample was 283.6 ± 18.2 mg/g. The current method was more convenient. It is adequate for the routine analysis of trans fat content in food products with low free fatty acid content.

Summary Massive multi-input multi-output has the advantages of high energy efficiency and spectrum use, but it also brings some problems because of cheap hardware use, such as high-power amplifier (HPA) nonlinearity. When the HPA operates in the nonlinear regime, nonlinear distortions, including amplitude and phase distortions, are introduced into the transmitted symbols, which in turn can cause adjacent channel interference and power losses. In this paper, we first study the deficiency of the conventional precoding algorithm when the HPA is nonlinear. Then, this paper proposes the improved precoding algorithms according to the effect of HPA nonlinearity on the signal, in which the adaptive factor is achieved to largely control the amplitude and phase distortions of the nonlinear HPA. Finally, the simulation results are provided and show that the proposed algorithms in this paper based on the relative block of diagonalization precoding and the forced zero precoding can efficiently decrease the bit error rate and increase the throughput, especially in the case of high signal-to-noise ratio.