bluuebunny/crossref_metadata_2025 huggingface dataset:
Using expert elicitation to quantify catchment water balances and their uncertainties
Authors: Sebok E. , Refsgaard J. C. , Warmink J. J. , Stisen S. , Jensen K. H.
Published: June 2016

Expert elicitation with the participation of 35 experts was used to estimate a water balance for the nested Ahlergaarde and Holtum catchments in Western Denmark. Average annual values of precipitation, evapotranspiration, and surface runoff as well as subsurface outflow and recharge and their uncertainty were estimated in a multistep elicitation, where experts first gave their opinion on the probability distribution of their water balance component of interest, then the average annual values and uncertainty of water balance components and catchment‐scale water balances were obtained by reaching consensus during group discussions. The obtained water balance errors for the 1055 km2 Ahlergaarde catchment and 120 km2 Holtum catchment were −5 and −62 mm/yr, respectively, with an uncertainty of 66 and 86 mm/yr, respectively. As an advantage of the expert elicitation, drawing on the intuitive experience and capabilities of experts to assess complex, site‐specific problems, the contribution of independent sources of uncertainties to the total uncertainty was also evaluated similarly to the subsurface outflow component, which traditionally is estimated as the residual of the water balance.
A hybrid statistical‐dynamical framework for meteorological drought prediction: Application to the southwestern United States
Authors: Madadgar Shahrbanou , AghaKouchak Amir , Shukla Shraddhanand , Wood Andrew W. , Cheng Linyin , Hsu Kou‐Lin , Svoboda Mark
Published: June 2016

Improving water management in water stressed‐regions requires reliable seasonal precipitation predication, which remains a grand challenge. Numerous statistical and dynamical model simulations have been developed for predicting precipitation. However, both types of models offer limited seasonal predictability. This study outlines a hybrid statistical‐dynamical modeling framework for predicting seasonal precipitation. The dynamical component relies on the physically based North American Multi‐Model Ensemble (NMME) model simulations (99 ensemble members). The statistical component relies on a multivariate Bayesian‐based model that relates precipitation to atmosphere‐ocean teleconnections (also known as an analog‐year statistical model). Here the Pacific Decadal Oscillation (PDO), Multivariate ENSO Index (MEI), and Atlantic Multidecadal Oscillation (AMO) are used in the statistical component. The dynamical and statistical predictions are linked using the so‐called Expert Advice algorithm, which offers an ensemble response (as an alternative to the ensemble mean). The latter part leads to the best precipitation prediction based on contributing statistical and dynamical ensembles. It combines the strength of physically based dynamical simulations and the capability of an analog‐year model. An application of the framework in the southwestern United States, which has suffered from major droughts over the past decade, improves seasonal precipitation predictions (3–5 month lead time) by 5–60% relative to the NMME simulations. Overall, the hybrid framework performs better in predicting negative precipitation anomalies (10–60% improvement over NMME) than positive precipitation anomalies (5–25% improvement over NMME). The results indicate that the framework would likely improve our ability to predict droughts such as the 2012–2014 event in the western United States that resulted in significant socioeconomic impacts.
The role of Equatorial Undercurrent in sustaining the Eastern Indian Ocean upwelling
Authors: Chen Gengxin , Han Weiqing , Shu Yeqiang , Li Yuanlong , Wang Dongxiao , Xie Qiang
Published: June 2016

By combining volume transport and salinity analysis from 1958 to 2014, this paper investigates how the transient Equatorial Undercurrent (EUC) sustains the summer‐fall equatorial eastern Indian Ocean (EIO) upwelling. On seasonal time scales, the EIO upwelling is mainly supplied by the salty water from the western basin through a buffering process: The winter‐spring EUC carries the salty water from the western basin eastward, induces downwelling in the EIO, and pushes portion of the salty water below the central thermocline, which subsequently upwells to the central thermocline during summer‐fall and sustains the EIO upwelling. On interannual time scales, enhanced upwelling occurs during positive Indian Ocean Dipole (+IOD) years. The strong summer‐fall EUC associated with the +IOD supplies water for the intensified upwelling. This research provides new knowledge for basin‐scale mass and property exchanges associated with the EIO upwelling, contributing to our understanding of three‐dimensional ocean circulation and climate variability.
Effect of cyclone Nilofar on mesospheric wave dynamics as inferred from optical nightglow observations from Mount Abu, India
Authors: Singh Ravindra P. , Pallamraju Duggirala
Published: June 2016

Mesospheric nightglow intensities at three emissions (O2(0–1), OH(6–2) bands, and Na(589.3 nm)) from a low‐latitude location, Gurushikhar, Mount Abu (24.6°N, 72.8°E), in India, showed similar wave features on 26 October 2014 with a common periodicity of around 4 h. A convective activity due to the cyclone Nilofar, which had developed in the Arabian Sea during 25–31 October 2014, was found to be the source as this too showed a gravity wave period coherent with that of the mesospheric emissions on the 26th. The periodicities at the source region were obtained using outgoing longwave radiation fluxes (derived from Kalpana‐1 satellite) which were used as a tracer of tropospheric activity. Cyclone Nilofar had two centers located at a distance of 1103 and 1665 km from the observational station. From the phase offset in time between residuals of O2 and OH emission intensities and the observed common periodicity the vertical phase speed and wavelength have been found to be 1.13 ms−1 and 16.47 km. From the wavelet analyses it is seen that the travel time of the wave from the convection region to O2 emission height was around 8.1 h. From these observations the horizontal phase speed and wavelength of the wave in the mesosphere were calculated to be 37.8 ms−1 and 553 km. These results thus provide not only unambiguous evidence on the vertical coupling of atmospheres engendered by the tropical cyclone Nilofar but also the characteristics of waves that exist during such cyclonic events.
Potential new production in two upwelling regions of the western Arabian Sea: Estimation and comparison
Authors: Liao Xiaomei , Zhan Haigang , Du Yan
Published: June 2016

Using satellite‐derived and in situ data, the wind‐driven potential new production (nitrate supply) for the 300 km wide coastal band in two upwelling regions of the western Arabian Sea (AS) during the southwest monsoon is estimated. The upward nitrate flux to the euphotic zone is generally based on the physical processes of coastal transport (Ekman transport and geostrophic transport) and offshore Ekman pumping. The coastal geostrophic current in the western AS influences the upwelling intensity and latitudinal distributions of nitrate supply. The Oman and Somalia upwelling regions have similar level of potential new production (nitrate supply) during the summer monsoon, while the satellite estimates of primary production off Oman are 2 times greater than those off Somalia. The much higher potential f‐ratio in the Somalia upwelling region indicates that the primary production could be limited by availability of other macronutrients (e.g., silicate). The correlation analysis of the primary production and the aerosol optical thickness shows that the Oman upwelling region displays a stronger coupling between the atmospheric deposition and the phytoplankton abundance. The high summertime dust levels in the atmosphere are suggested to contribute to the high primary production in the Oman upwelling region.
Climatology and linear trends of seasonal water temperature and heat budget in a semienclosed sea connected to the Kuroshio region
Authors: Tsutsumi Eisuke , Guo Xinyu
Published: June 2016

The climatology and linear trend of seasonal water temperature and heat budget in a semienclosed sea connected to the Kuroshio region (Seto Inland Sea: SIS) are investigated by constructing and analyzing a gridded data set of water temperature, salinity, and air‐sea heat fluxes. In the SIS, winter‐time water temperature and ocean heat content (OHC) showed a significant increasing trend while those in summer‐time exhibited no significant change. By analyzing the heat budget between the tendency of ocean heat content ∂OHC/∂t and air‐sea net heat flux Qnet, the driving factor of the winter‐time warming trend in the SIS was identified as autumn Qnet, while the unchanged summer‐time OHC is mainly due to decreased spring‐time oceanic heat transport to the SIS from the Kuroshio region. In addition, we showed that the decreased spring‐time heat transport could have been induced by upwelling due to wind curl and wind speed in the shelf‐slope region, heat transport by the Kuroshio south of Shikoku Island, and freshwater input to the SIS from rivers. The importance of both oceanic and atmospheric forcing mechanisms for explaining variation in the water temperature in coastal areas is demonstrated.
Identification and Characterization of D‐Succinylase, and a Proposed Enzymatic Method for D‐Amino Acid Synthesis
Authors: Sumida Yosuke , Iwai Sachio , Nishiya Yoshiaki , Kumagai Shinya , Yamada Toshihide , Azuma Masayuki
Published: June 2016

Chiral amino acids are important intermediates for the pharmaceutical industry. We have developed a novel one‐pot enzymatic method for D‐amino acid synthesis by the dynamic kinetic resolution of N‐succinyl‐dl‐amino acids using D‐succinylase (DSA) and N‐succinylamino acid racemase (NSAR, EC 4.2.1.113). The DSA from Cupriavidus sp. P4‐10‐C, which hydrolyzes N‐succinyl‐D‐amino acids enantioselectively to their corresponding D‐amino acids, was identified for the first time by screening soil microorganisms. Subsequently, the DSA gene was cloned and overexpressed in Escherichia coli. DSA was shown to comprise two subunits with molecular masses of 26 kDa and 60 kDa. Additionally, the NSAR gene from Geobacillus stearothermphilus NCA1503, which racemizes N‐succinylamino acids, was also cloned and overexpressed in E. coli. The highly purified DSA and NSAR prepared from each recombinant E. coli were characterized and used for D‐amino acid synthesis. A one‐pot enzymatic method converted 100 mM N‐succinyl‐dl‐phenylalanine to D‐phenylalanine in 91.1% conversion with 86.7% ee. This novel enzymatic method may be useful for the industrial production of many D‐amino acids.

magnified image
Silver‐Catalyzed Intramolecular C‐2 Selective Acylation of Indoles with Aldehydes: An Atom‐Economical Entry to Indole‐Indolone Scaffolds
Authors: Wang Xiaoxia , Li Zhongfeng , Cao Shengli , Rao Honghua
Published: June 2016

A direct annulation reaction of N‐(2‐formylaryl)indoles has been developed, which can provide a new entry to biologically and medicinally important indole‐indolone scaffolds via a silver‐catalyzed direct oxidative coupling between aldehyde CH and sp2 CH bonds for the first time. Remarkably, this strategy displayed excellent functional group compatibilities, thereby suggesting its wide potential for applications in developing and synthesizing new drug‐like compounds containing indole‐indolone frameworks.

magnified image
Copper‐Mediated 1,2‐Difunctionalization of Styrenes with Sodium Arylsulfinates and tert‐Butyl Nitrite: Facile Access to α‐Sulfonylethanone Oximes
Authors: Yang Ji , Liu Yan‐Yun , Song Ren‐Jie , Peng Zhi‐Hong , Li Jin‐Heng
Published: June 2016

A new copper‐mediated synthesis of α‐sulfonylethanone oximes from styrenes, sodium arylsulfinates and tert‐butyl nitrite (t‐BuONO; TBN) is presented. This intermolecular three‐component method enables the one‐step formation of CN and CS bonds under mild conditions, and represents a new, straightforward approach to α‐sulfonylethanone oximes.

magnified image
Nickel(II)‐Mediated Regioselective CH Monoiodination of Arenes and Heteroarenes by using Molecular Iodine
Authors: Khan Bhuttu , Kant Ruchir , Koley Dipankar
Published: June 2016

The 8‐aminoquinoline‐directed, nickel(II)‐mediated ortho‐iodination of benzamides using molecular iodine has been developed. The process is highly regioselective and furnishes only monoiodinated products. A broad range of arenes and heteroarenes with diverse functional groups provided monoiodinated products in good to excellent yields.

magnified image
Gene frequency and haplotype distribution of hemoglobin E among seven minority groups of Yunnan, China
Authors: Liu Hongxian , Huang Kai , Liu Shuyuan , Sun Hao , Lin Keqin , Huang Xiaoqin , Chu Jiayou , Yang Zhaoqing
Published: June 2016

Objective

The aim of this study was to determine the distribution and origin of hemoglobin E (HbE) in seven minority groups from various geographical regions of the malaria‐endemic Yunnan province, southwestern China, which have similar ethnic origins and geographic relationships with HbE‐prevalent populations of Southeast Asian countries.

Methods

By using Polymerase Chain Reaction‐Restriction Fragment Length Polymorphism (PCR‐RFLP) methods, the prevalence of HbE was examined in 1488 individuals from seven native minority groups of Yunnan, and β‐globin gene cluster haplotypes were determined on 1420 chromosomes.

Results

The prevalence of HbE in the study populations ranged from 1.5 to 39.1%. Higher HbE prevalence was correlated with the minority groups of Tibeto‐Burman origin and groups from the Dehong district. The βE–globin genes in Yunnan were mostly associated with three haplotypes [−+++++−], [+−−−−+−], and [−+−+++−] on chromosomes with gene framework 2. Interestingly, the predominant βE associated haplotype in Yunnan minorities was remarkably different from that in other previously reported populations. This study, for the first time, reports population‐based data on the heterogeneity of HbE gene frequencies and haplotype distribution in native minorities from southwestern China.

Conclusions

Natural selection based on the presence of malaria, ethnic origin, and epistatic interactions may be factors of varying importance for the remarkable variation in HbE frequency among these minority groups. In addition, there appears to be a common origin of the βE ‐globin gene in populations from Yunnan and Southeast Asia. Am. J. Hum. Biol. 28:927–931, 2016. © 2016Wiley Periodicals, Inc.
Synthesis of α‐MoC1−x Nanoparticles with a Surface‐Modified SBA‐15 Hard Template: Determination of Structure–Function Relationships in Acetic Acid Deoxygenation
Authors: Baddour Frederick G. , Nash Connor P. , Schaidle Joshua A. , Ruddy Daniel A.
Published: June 2016

Surface modification of mesoporous SBA‐15 silica generated a hydrophobic environment for a molybdenum diamine (Mo‐diamine) precursor solution, enabling direct growth of isolated 1.9±0.4 nm α‐MoC1−x nanoparticles (NPs) inside the pores of the support. The resulting NP catalysts are bifunctional, and compared to bulk α‐MoC1−x and β‐Mo2C, the NPs exhibit a greater acid‐site:H‐site ratio and a fraction of stronger acid sites. The greater acid‐site:H‐site ratio results in higher decarbonylation (DCO) selectivity during acetic acid hydrodeoxygenation (HDO) reactions, and the stronger acid sites lead to higher activity and ketonization (KET) selectivity at high temperatures. The hard‐templating synthetic method could be a versatile route toward carbide NPs of varying size, composition, and phase, on a range of mesoporous oxide supports.
19F NMR Spectroscopy as a Highly Sensitive Method for the Direct Monitoring of Confined Crystallization within Nanoporous Materials
Authors: Nartowski Karol P. , Malhotra Diksha , Hawarden Lucy E. , Sibik Juraj , Iuga Dinu , Zeitler J. Axel , Fábián László , Khimyak Yaroslav Z.
Published: June 2016

The introduction of fluorine into the structure of pharmaceuticals has been an effective strategy for tuning their pharmacodynamic properties, with more than 40 new drugs entering the market in the last 15 years. In this context, 19F NMR spectroscopy can be viewed as a useful method for investigating the host–guest chemistry of pharmaceuticals in nanosized drug‐delivery systems. Although the interest in confined crystallization, nanosized devices, and porous catalysts is gradually increasing, understanding of the complex phase behavior of organic molecules confined within nanochambers or nanoreactors is still lacking. Using 19F magic‐angle‐spinning NMR spectroscopy, we obtained detailed mechanistic insight into the crystallization of flufenamic acid (FFA) in a confined environment of mesoporous silica materials with different pore diameters (3.2–29 nm), providing direct experimental evidence for the formation of a molecular‐liquid‐like layer besides crystalline confined FFA form I.
Enantioselective Palladium‐Catalyzed Oxidative β,β‐Fluoroarylation of α,β‐Unsaturated Carbonyl Derivatives
Authors: Miró Javier , del Pozo Carlos , Toste F. Dean , Fustero Santos
Published: June 2016

The site‐selective palladium‐catalyzed three‐component coupling of deactivated alkenes, arylboronic acids, and N‐fluorobenzenesulfonimide is disclosed herein. The developed methodology establishes a general, modular, and step‐economical approach to the stereoselective β‐fluorination of α,β‐unsaturated systems.
5‐Fluorouracil encapsulated magnetic nanohydrogels for drug‐delivery applications
Authors: Jayaramudu Tippabattini , Raghavendra Gownolla Malegowd , Varaprasad Kokkarachedu , Raju Konduru Mohana , Sadiku Emmanuel Rotimi , Kim Jaehwan
Published: June 2016

For the first time, green‐tea (GT)‐based magnetic nanohydrogels were developed for drug‐delivery purposes. The hydrogel matrices were fabricated via the in situ polymerization of acrylamide with GT molecules. Magnetic nanoparticles were synthesized by the reduction of the 1:2 molar ratio mixture of ferrous sulfate heptahydrate and ferric chloride hexahydrate with an ammonia solution. A chemotherapeutic drug, 5‐fluorouracil, was chosen as a model drug, and its releasing profiles in the presence and absence of the external magnetic field were evaluated at a pH of 7.4. We observed that in the presence of the applied magnetic field, these magnetic nanohydrogels released 2.86% more drug than in the absence of a magnetic field. The magnetic nanohydrogels were characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometry, and transmission electron microscopy. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43921.
Preparation of waterborne polyurethane nanocomposite reinforced with halloysite nanotubes for coating applications
Authors: Wu Yan , Du Zongliang , Wang Haibo , Cheng Xu
Published: June 2016

To construct waterborne polyurethane with excellent water resistance and mechanical properties, an organic‐inorganic hybrid nanocomposite based on modified halloysite nanotubes (mHNTs) and polyurethane was prepared. The HNTs were modified with an amino‐silane coupling agent (KH550) and then reacted with polypropylene glycol, 2,2‐Dimethylol propionic acid, and Toluene diisocyanate to form mHNTs/PU aqueous dispersions. The structure of the siloxane functionalized mHNTs was confirmed by a Fourier transform infrared study. The PU/mHNTs composites were characterized by using differential scanning calorimetry, scanning electronic microscopy, thermal gravimetric analysis, a tensile test, particle size analysis, and a water swelling experiment. The tensile strength, Young's modulus, and elongation at the break of the composite polymer with 0.5 wt % mHNTs was shown to be significantly improved, by approximately 200%, 200%, and 30%, respectively. An excess amount of mHNTs could weaken the reinforcing effect and stability of the composite emulsion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43949.
Glutaraldehyde‐crosslinking for improved copper absorption selectivity and chemical stability of polyethyleneimine coatings
Authors: Lindén Johan B. , Larsson Mikael , Kaur Simarpreet , Nosrati Ataollah , Nydén Magnus
Published: June 2016

Nano‐thin coatings of glutaraldehyde (GA)‐crosslinked polyethyleneimine (PEI) are extremely selective and effective in binding copper from seawater. Here it was demonstrated that GA‐PEI performs significantly different from PEI. The copper‐selectivity of self‐assembled PEI coatings on silicon substrates was greatly improved by GA‐crosslinking. After submersion in artificial seawater containing 200 ppb copper and equimolar amounts of 11 competing ions only copper and trace amounts of Zn were detected in the GA‐crosslinked coatings, while for non‐crosslinked PEI there was about 30% Zn present relative to copper. The coatings were demonstrated to be highly stable under acidic conditions and retained their copper‐binding selectivity after repeated cycles of binding and acid‐mediated elution. After self‐assembly of the GA‐crosslinked coating on mesoporous diatomaceous earth particles, significant amounts of copper could be extracted from 200 ppb in artificial seawater and eluted under acidic pH. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43954.
Synergistic toughening effect of chlorinated polyethylene and acrylic resin on SAN/ASA blends at low temperature
Authors: Mao Zepeng , Zhang Jun
Published: June 2016

Styrene–acrylonitrile copolymer (SAN)/acrylonitrile–styrene–acrylate terpolymer (ASA) blends (75/25, w/w) were toughened by blending with chlorinated polyethylene (CPE) and acrylic resin (ACR) at three different temperatures (−30, 0, and 25 °C). When the testing temperature was 0 and 25 °C, CPE played a key role in improving the impact strength of blends instead of ACR. However, an obvious synergistic toughening effect of CPE and ACR was observed at −30 °C: when both 10 phr CPE and 15 phr ACR were added, the impact strength of the blends reached a peak at 7.50 kJ/m2, which was about two to three times higher than when 25 phr CPE or 25 phr ACR was introduced into the blends individually. Scanning electron microscopy, dynamic mechanical analysis, and surface energy measurements were used to investigate the toughening mechanism. Furthermore, other mechanical properties and the heat distortion temperatures were evaluated. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43958.
Excitation Energy Transfer in meta‐Substituted Phenylacetylene Multibranched Chromophores
Authors: He Guiying , Yu Chenmin , Li Yang , Hu Jiangpu , Liu Zitong , Zhang Deqing , Guo Qianjin , Xia Andong
Published: June 2016

A comprehensive investigation into the spectral properties and excitation energy transfer in di‐ or tribranched dithienyldiketopyrrolopyrrole (DPP) molecules with meta‐substituted benzene as a central core (TADPP2‐TT and TADPP3), by means of steady‐state and transient measurements and quantum chemical calculations, is reported. Excitation in the meta‐substituted chromophores is localized on one of the DPP units in the branching molecules owing to the disruption of conjugation by meta substitution for both TADPP2‐TT and TADPP3. Weak electronic couplings result from the long distance between the DPP chromophores and the steric effects from the attached side chains on DPP. The attachment of the acetylene linker in each branch, which has a very low twisting barrier, could also play an important role in reducing the interaction between DPP chromophores. The dynamics of the excited states show that excitation energy transfer occurs on the picosecond scale, which is attributed to the incoherent hopping mechanism.
Trend and pattern classification of surface air temperature change in the Arctic region
Authors: Wanishsakpong Wandee , McNeil Nittaya , Notodiputro Khairil A.
Published: June 2016

Monthly seasonally adjusted temperatures above latitude 45°N were investigated from January 1973 to November 2013. The study area was divided into 69 sub‐regions of similar size each in the shape of an igloo brick. The data were filtered with a second‐order autoregressive process to remove autocorrelation. Two sub‐regions did not have sufficient data due to substantial numbers of missing values. Factor analysis was then applied to the remaining 67 sub‐regions and was used to classify regions with similar temperature changes. As a result, 63 sub‐regions could be classified based on 12 factors but 4 sub‐regions could not be grouped due to uniqueness. The temperatures for each group of sub‐regions were found to increase during 1973–2013. The largest temperature increases of 0.19 °C/decade were found in northern and southern Siberia and part of the Arctic Ocean. In northern Canada, Alaska, the northern Pacific Ocean and eastern Siberia the temperatures increased by at least 0.16 °C/decade. In Iceland, Norway, Sweden and part of the Pacific and Arctic Oceans the temperature increased by around 0.15 °C/decade. In northeastern Canada, Greenland and its surrounding Atlantic Ocean and the Arctic Ocean the temperature increased by about 0.15 °C/decade.
Comparisons of pharmacokinetics and NO‐releasing of nitrofibriate and fenofibrate after oral administration in rats
Authors: Yang Yujie , Cheng Qiang , Liu Xiumei , Liu Zejuan , Li Tingting , Jiang Xuehua , Wang Ling
Published: June 2016

Nitrofibriate, a new compound of hypolipidemic, is modified based on fenofibrate. Both of them are used for prevention and treatment of cardiovascular diseases. In this study, an accurate and sensitive analytical method of reversed‐phase high‐performance liquid chromatography was developed to determine fenofibric acid, which is an active metabolite of both nitrofibriate and fenofibrate in rat plasma. This method was validated and successfully applied to pharmacokinetic study of nitrofibriate and fenofibrate after oral administration. The results suggested that the pharmacokinetic behavior of nitrofibriate followed a nonlinear process, while fenofibrate was linear, demonstrating that the two drugs were different in pharmacokinetic behaviors. Moreover, the effect of fenofibrate and nitrofibriate on releasing NO in rat serum was explored. This study showed that nitrofibriate, as a nitric oxide donor, could slowly release nitric oxide in vivo. This study provided a biopharmaceutical basis for further study of nitrofibriate.
Physicochemical Profiling of α‐Lipoic Acid and Related Compounds
Authors: Mirzahosseini Arash , Szilvay András , Noszál Béla
Published: June 2016

Lipoic acid, the biomolecule of vital importance following glycolysis, shows diversity in its thiol/disulfide equilibria and also in its eight different protonation forms of the reduced molecule. In this paper, lipoic acid, lipoamide, and their dihydro derivatives were studied to quantify their solubility, acid–base, and lipophilicity properties at a submolecular level. The acid–base properties are characterized in terms of six macroscopic, 12 microscopic protonation constants, and three interactivity parameters. The species‐specific basicities, the pH‐dependent distribution of the microspecies, and lipophilicity parameters are interpreted by various intramolecular effects, and contribute to understanding the antioxidant, chelate‐forming, and enzyme cofactor behavior of the molecules observed.
Cytotoxic Constituents and Mechanism from Peganum harmala
Authors: Wang Chunhua , Zhang Zhenxue , Wang Yihai , He Xiangjiu
Published: June 2016

Peganum harmala L. is a traditional Chinese and Uygur medicine used to treat cancer. Bioactivity‐guided fractionation was applied to determine the cytotoxic constituents from P. harmala. A novel triterpenoid and a phenolic glycoside were isolated and identified, as well as seven known compounds. The novel metabolites were elucidated to be 3α‐acetoxy‐27‐hydroxyolean‐12‐en‐28‐oic acid methyl ester (1, OA) and N‐acetyl‐9‐syringinoside (9). Some compounds exhibited potent cytotoxicity against human tumor cells. Among them, OA showed the highest cytotoxicity against human lung cancer cells A549 with an IC50 value of 8.03 ± 0.81 μm. OA had a potent anti‐NSCLC cell activity by interfering with the epidermal growth factor receptor (EGFR) activation and its downstream signaling, and could exert an antiproliferative effect by inactivation of EGFR‐driven antiapoptotic pathway followed by the release of mitochondrial cytochrome c, which might prove to be a promising leading compound for the development of an anti‐lung cancer drug.
High Spatial Resolution Imaging of Endogenous Hydrogen Peroxide in Living Cells by Solid‐State Fluorescence
Authors: Lindberg Eric , Winssinger Nicolas
Published: June 2016

Herein, we describe selective imaging of hydrogen peroxide using a precipitating dye conjugated to a boronic acid‐based immolative linker. We achieved visualization of endogenous hydrogen peroxide in phagosomes by solid‐state two‐photon fluorescence imaging in living cells with exceptionally high spatial resolution.
Transfer Hydrogenation and Hydrogenation of Commercial‐Grade Aldehydes to Primary Alcohols Catalyzed by 2‐(Aminomethyl)pyridine and Pincer Benzo[h]quinoline Ruthenium Complexes
Authors: Baldino Salvatore , Facchetti Sarah , Zanotti‐Gerosa Antonio , Nedden Hans Günter , Baratta Walter
Published: June 2016

The chemoselective reduction of commercial‐grade aldehydes (97–99 %) to primary alcohols is achieved with cis‐[RuCl2(ampy)(PP)] [ampy=2‐(aminomethyl)pyridine; PP=1,4‐bis(diphenylphosphino)butane, 1,1′‐ferrocenediyl‐bis(diphenylphosphine)] and pincer [RuCl(CNNR)(PP)] [PP=1,3‐bis(diphenylphosphino)propane, 1,4‐bis(diphenylphosphino)butane, 1,1′‐ferrocenediyl‐bis(diphenylphosphine); HCNNR=4‐substituted‐2‐aminomethyl‐benzo[h]quinoline; R=Me, Ph] complexes by transfer hydrogenation and hydrogenation reactions. Aromatic, conjugated, and aliphatic aldehydes are converted quantitatively to the corresponding alcohols using 2‐propanol with potassium carbonate at substrate/catalyst ratios up to 100 000 by transfer hydrogenation, whereas aldehyde hydrogenation (5–20 atm of H2) is achieved efficiently in MeOH in the presence of KOtBu at substrate/catalyst ratios up to 40 000.
Platinum(II) Metallomesogens: New External‐Stimuli‐Responsive Photoluminescence Materials
Authors: Cuerva Cristián , Campo José A. , Cano Mercedes , Lodeiro Carlos
Published: June 2016

New dicatenar isoquinoline‐functionalized pyrazoles, [HpzR(n,n)iq] (R(n,n)=C6H3(OCnH2n+1)2; n=4, 6, 8, 10, 12, 14, 16, 18), have been strategically designed and synthesized to induce mesomorphic and luminescence properties into the corresponding bis(isoquinolinylpyrazolate)platinum(II) complexes [Pt(pzR(n,n)iq)2]. Thermal studies reveal that all platinum(II) compounds exhibit columnar mesophases over an exceptionally wide temperature range, above 300 °C in most cases. The photophysical behavior was also investigated in solution and in the solid state. As a consequence of the formation of Pt⋅⋅⋅Pt interactions, the weak greenish emission of the platinum derivatives turns bright orange in the mesophase. Additionally, the complexes are sensitive to a great variety of external inputs, such as temperature, mechanical grinding, pressure, solvents, and vapors. On this basis, they are used as dopant agents of a polyvinylpyrrolidone or poly(methyl methacrylate) polymer matrix to achieve stimuli‐responsive thin films.
Introduction of d‐Glutamate at a Critical Residue of Aβ42 Stabilizes a Prefibrillary Aggregate with Enhanced Toxicity
Authors: Warner Christopher J. A. , Dutta Subrata , Foley Alejandro R. , Raskatov Jevgenij A.
Published: June 2016

The amyloid beta peptide 42 (Aβ42) is an aggregation‐prone peptide that plays a pivotal role in Alzheimer′s disease. We report that a subtle perturbation to the peptide through a single chirality change at glutamate 22 leads to a pronounced delay in the β‐sheet adoption of the peptide. This was accompanied by an attenuated propensity of the peptide to form fibrils, which was correlated with changes at the level of the fibrillary architecture. Strikingly, the incorporation of d‐glutamate was found to stabilize a soluble, ordered macromolecular assembly with enhanced cytotoxicity to PC12 cells, highlighting the importance of advanced prefibrillary Aβ aggregates in neurotoxicity.
Methylene Homologues of Artemisone: An Unexpected Structure–Activity Relationship and a Possible Implication for the Design of C10‐Substituted Artemisinins
Authors: Wu Yuet , Wu Ronald Wai Kung , Cheu Kwan Wing , Williams Ian D. , Krishna Sanjeev , Slavic Ksenija , Gravett Andrew M. , Liu Wai M. , Wong Ho Ning , Haynes Richard K.
Published: June 2016

We sought to establish if methylene homologues of artemisone are biologically more active and more stable than artemisone. The analogy is drawn with the conversion of natural O‐ and N‐glycosides into more stable C‐glycosides that may possess enhanced biological activities and stabilities. Dihydroartemisinin was converted into 10β‐cyano‐10‐deoxyartemisinin that was hydrolyzed to the α‐primary amide. Reduction of the β‐cyanide and the α‐amide provided the respective methylamine epimers that upon treatment with divinyl sulfone gave the β‐ and α‐methylene homologues, respectively, of artemisone. Surprisingly, the compounds were less active in vitro than artemisone against P. falciparum and displayed no appreciable activity against A549, HCT116, and MCF7 tumor cell lines. This loss in activity may be rationalized in terms of one model for the mechanism of action of artemisinins, namely the cofactor model, wherein the presence of a leaving group at C10 assists in driving hydride transfer from reduced flavin cofactors to the peroxide during perturbation of intracellular redox homeostasis by artemisinins. It is noted that the carba analogue of artemether is less active in vitro than the O‐glycoside parent toward P. falciparum, although extrapolation of such activity differences to other artemisinins at this stage is not possible. However, literature data coupled with the leaving group rationale suggest that artemisinins bearing an amino group attached directly to C10 are optimal compounds.
Distributed mirror descent method for saddle point problems over directed graphs
Authors: Li Jueyou , Chen Guo , Dong Zhaoyang , Wu Zhiyou , Yao Minghai
Published: June 2016

In this article, we consider a mini‐max multi‐agent optimization problem where multiple agents cooperatively optimize a sum of local convex–concave functions, each of which is available to one specific agent in a network. To solve the problem, we propose a distributed optimization method by extending classical mirror descent algorithms to the distributed setting. We obtain the convergence of the algorithm under wild conditions that the agent communication follows a directed graph and the related weighted matrices are row stochastic. In particular, when the weighted matrices are restricted to be doubly stochastic, we provide the explicit convergence rate of the algorithm by choosing the stepsize in a suitable way. The proposed algorithm can be viewed as a generalization of the subgradient projection methods since it utilizes a customized Bregman divergence instead of the usual Euclidean squared distance. Finally, some simulation results on a matrix game are presented to illustrate the performance of the algorithm. © 2016 Wiley Periodicals, Inc. Complexity 21: 178–190, 2016
Thrombin generation assay in untreated whole human blood
Authors: Modestino Augusta , Tyndall Matthew , Yu Johnson , Lefkowitz Roy B. , Schmid‐Schönbein Geert W. , Heller Michael J.
Published: June 2016

Present coagulation assays fail to detect mild coagulation disorders, while thrombin‐generation (TG) assays solve this problem. However, most of them only work with threated blood samples, which makes them labor intensive, time consuming, unreliable, and expensive. We have developed a TG electrophoretic assay that uses a thrombin specific charge‐changing fluorescent peptide substrate, electrophoretic separation, and requires a drop of blood. The limit of detection of the assay was 1.97 nM in phosphate buffer saline and 6.82 nM in citrated whole blood. The assay was used to determine the TG in whole blood from healthy volunteers (n = 6, one aspirin user), over 30 min, after the blood was drawn; the TG increased from a baseline level of 2 × 106 RFU to 1.2 × 1013 RFU. The lag time between the blood draw and initial burst of TG was 6 min for the volunteers (n = 5) and 15 min for the aspirin user. Specificity of the assay was evaluated by reacting our substrate with the heparinized blood samples and other proteases. The TG electrophoretic assay was designed and tested in the whole human blood, requiring no sample preparation, 5 μL of blood, 45 min, and it detected differences in coagulation patterns between a volunteer taking aspirin and non‐aspirin users.
Determination of the inhibitor dissociation constant of an individual unmodified enzyme molecule in free solution
Authors: Crawford Jeremie J , Hollett Joshua W , Craig Douglas B
Published: June 2016

Single enzyme molecule assays on E. coli β‐galactosidase were performed using a capillary electrophoresis‐based method. Three types of assays were performed. The catalytic rate of 20 individual molecules was assayed in duplicate in the presence of 50 μM substrate. The ratio of rates for the second incubation relative to the first was 0.96 ± 0.03, showing the reproducibility of the method. In the second assay, the rates were determined in the absence and presence of 210 μM L‐ribose, a competitive inhibitor. The ratio of the rate in the presence of inhibitor to that in its absence for 19 individual molecules was 0.44 ± 0.23. This large relative standard deviation suggests that each individual enzyme molecule was affected to a different extent by the presence of the inhibitor, which is consistent with KI being heterogeneous. To estimate KI for individual molecules, a third assay was performed. Each molecule was incubated in the presence of 30 and 50 μM substrate and then in the presence of 50 μM substrate plus 210 μM inhibitor. Comparison of the rates in the two substrate concentrations allowed for the determination of the individual Km of each molecule. From this value and the difference in rates in the presence and absence of inhibitor, the individual molecule KI values were determined. This value was found to differ between individual molecules and was found to increase with an increase in Km. Modeling showed that a heterogeneity in KI results in an alteration in the Michaelis–Menten curve for a population of enzymes in the presence of a competitive inhibitor.
Photoinitiated miniemulsion polymerization in microfluidic chips on automated liquid handling stations: Proof of concept
Authors: Radtke Carsten Philipp , Delbé Michèle , Wörner Michael , Hubbuch Jürgen
Published: June 2016

Photoinitiated polymerization is usually applied in the area of specialty chemicals and UV curing but can also be employed in the production of biofunctional polymers and nanocapsules. A promising approach for the preparation of those polymers is the photoinitiated polymerization of miniemulsions. Here, the mild reaction conditions are beneficial for the integration of sensitive biomaterials into the process. The optimal combination of different varied cause variables like irradiance, irradiation time, and height of the irradiated volume is crucial for an appropriate polymerization result. For the presented proof of concept study, a microfluidic tool was established to screen these cause variables in an automated high throughput manner on a liquid handling station (LHS). The experiments are planned and executed by means of a design of experiments (DoE) approach to investigate the effect of the variables on the residual monomer content (RMC) within the stated design space. As the RMC is considered as crucial for bioapplications, the optimal parameter combinations for the complete monomer conversion have been determined. The model‐based evaluation of the executed experiments resulted a channel height respectively optical path of 200–400 μm, an irradiance of 65% (equals 44.2 mW/cm²) and an irradiation time of 30 s for complete styrene conversion.
Vertical farming increases lettuce yield per unit area compared to conventional horizontal hydroponics
Authors: Touliatos Dionysios , Dodd Ian C. , McAinsh Martin
Published: June 2016

Vertical farming systems (VFS) have been proposed as an engineering solution to increase productivity per unit area of cultivated land by extending crop production into the vertical dimension. To test whether this approach presents a viable alternative to horizontal crop production systems, a VFS (where plants were grown in upright cylindrical columns) was compared against a conventional horizontal hydroponic system (HHS) using lettuce (Lactuca sativa L. cv. “Little Gem”) as a model crop. Both systems had similar root zone volume and planting density. Half‐strength Hoagland's solution was applied to plants grown in perlite in an indoor controlled environment room, with metal halide lamps providing artificial lighting. Light distribution (photosynthetic photon flux density, PPFD) and yield (shoot fresh weight) within each system were assessed. Although PPFD and shoot fresh weight decreased significantly in the VFS from top to base, the VFS produced more crop per unit of growing floor area when compared with the HHS. Our results clearly demonstrate that VFS presents an attractive alternative to horizontal hydroponic growth systems and suggest that further increases in yield could be achieved by incorporating artificial lighting in the VFS.
Significant reductions in human visual gamma frequency by the gaba reuptake inhibitor tiagabine revealed by robust peak frequency estimation
Authors: Magazzini Lorenzo , Muthukumaraswamy Suresh D. , Campbell Anne E. , Hamandi Khalid , Lingford‐Hughes Anne , Myers Jim F. M. , Nutt David J. , Sumner Petroc , Wilson Sue J. , Singh Krish D.
Published: June 2016

The frequency of visual gamma oscillations is determined by both the neuronal excitation–inhibition balance and the time constants of GABAergic processes. The gamma peak frequency has been linked to sensory processing, cognitive function, cortical structure, and may have a genetic contribution. To disentangle the intricate relationship among these factors, accurate and reliable estimates of peak frequency are required. Here, a bootstrapping approach that provides estimates of peak frequency reliability, thereby increasing the robustness of the inferences made on this parameter was developed. The method using both simulated data and real data from two previous pharmacological MEG studies of visual gamma with alcohol and tiagabine was validated. In particular, the study by Muthukumaraswamy et al. [] (Neuropsychopharmacology 38(6):1105–1112), in which GABAergic enhancement by tiagabine had previously demonstrated a null effect on visual gamma oscillations, contrasting with strong evidence from both animal models and very recent human studies was re‐evaluated. After improved peak frequency estimation and additional exclusion of unreliably measured data, it was found that the GABA reuptake inhibitor tiagabine did produce, as predicted, a marked decrease in visual gamma oscillation frequency. This result demonstrates the potential impact of objective approaches to data quality control, and provides additional translational evidence for the mechanisms of GABAergic transmission generating gamma oscillations in humans. Hum Brain Mapp 37:3882–3896, 2016. © 2016 Wiley Periodicals, Inc.
Climate Change Impacts on Agricultural Drought with Consideration of Uncertainty in CMIP5 Scenarios
Authors: Cho Jaepil , Ko Gwangdon , Kim Kwangyoung , Oh Chansung
Published: June 2016

This study was conducted to evaluate the impact of climate change on agricultural drought on 104 agricultural reservoirs in Korea. The bias corrected data appropriately reproduced the temporal trends of inflow from upstream river basins, irrigation water demand from paddy areas and reservoir storage level. When eleven climate model data were applied to a representative reservoir, inflow by individual models had a range of ‐11.5 to 11.1%, compared to the multi‐model ensembles mean value. Water demand also showed a similar trend to the inflow, had a range of ‐11.0 to 10.0%, while storage level had a narrow range of ‐3.9 to 2.1%. When 104 reservoirs were considered, inflow in the future period (2011 ~ 2040) increased by 7.8 and 9.3% for the Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios, respectively, mainly due to the increase in precipitation. Similarly, irrigation water demand increased by 2.3 and 1.6% for RCP4.5 and 8.5, respectively, due to the increase in temperature. As a result, the water storage level increased by 0.7 and 0.5% for RCP4.5 and 8.5, respectively. However, despite the increase in average reservoir storage level, the frequency of the number of droughts more severe than 10 year frequency drought increased. Copyright © 2016 John Wiley & Sons, Ltd.
Comparative Effect of Quercetin and Quercetin‐3‐O‐β‐d‐Glucoside on Fibrin Polymers, Blood Clots, and in Rodent Models
Authors: Choi Jun‐Hui , Kim Kyung‐Je , Kim Seung
Published: June 2016

The present study evaluates the in vitro, in vivo, and ex vivo antithrombotic and anticoagulant effect of two flavonoids: quercetin and quercetin‐3‐O‐β‐d‐glucoside (isoquercetin). The present results have shown that quercetin and isoquercetin inhibit the enzymatic activity of thrombin and FXa and suppress fibrin clot formation and blood clotting. The prolongation effect of quercetin and isoquercetin against epinephrine and collagen‐induced platelet activation may have been caused by intervention in intracellular signaling pathways including coagulation cascade and aggregation response on platelets and blood. The in vivo and ex vivo anticoagulant efficacy of quercetin and isoquercetin was evaluated in thrombin‐induced acute thromboembolism model and in ICR mice. Our findings showed that in vitro and in vivo inhibitory effects of quercetin were slightly higher than that of quercetin glucoside, whereas in vitro and ex vivo anticoagulant effects of quercetin were weaker than that of quercetin glucoside because of their structural characteristics.
Neuro‐Modulation of Immuno‐Endocrine Response Induced by Kaliotoxin of Androctonus Scorpion Venom
Authors: Ladjel‐Mendil Amina , Martin‐Eauclaire Marie‐France , Laraba‐Djebari Fatima
Published: June 2016

Kaliotoxin (KTX), a specific blocker of potassium channels, exerts various toxic effects due to its action on the central nervous system. Its use in experimental model could help the understanding of the cellular and molecular mechanisms involved in the neuropathological processes related to potassium channel dysfunctions. In this study, the ability of KTX to stimulate neuro‐immuno‐endocrine axis was investigated. As results, the intracerebroventricular injection of KTX leads to severe structural–functional alterations of both hypothalamus and thyroid. These alterations were characterized by a massive release of hormones’ markers of thyroid function associated with damaged tissue which was infiltrated by inflammatory cell and an imbalanced redox status. Taken together, these data highlight that KTX is able to modulate the neuro‐endocrine response after binding to its targets leading to the hypothalamus and the thyroid stimulation, probably by inflammatory response activation and the installation of oxidative stress in these organs.