bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a relative quantification method for infrared matrix‐assisted laser desorption electrospray ionization mass spectrometry imaging of Arabidopsis seedlings
Authors: Bagley M. Caleb , Stepanova Anna N. , Ekelöf Måns , Alonso Jose M. , Muddiman David C. 
Published: October 2019

RationaleMass spectrometry imaging of young seedlings is an invaluable tool in understanding how mutations affect metabolite accumulation in plant development. However, due to numerous biological considerations, established methods for the relative quantification of analytes using infrared matrix‐assisted laser desorption electrospray ionization (IR‐MALDESI) mass spectrometry imaging are not viable options. In this study, we report a method for the quantification of auxin‐related compounds using stable‐isotope‐labelled (SIL) indole‐3‐acetic acid (IAA) doped into agarose substrate.MethodsWild‐type Arabidopsis thaliana seedlings, sur2 and wei8 tar2 loss‐of‐function mutants, and YUC1 gain‐of‐function line were grown for 3 days in the dark in standard growth medium. SIL‐IAA was doped into a 1% low‐melting‐point agarose gel and seedlings were gently laid on top for IR‐MALDESI imaging with Orbitrap mass spectrometry analysis. Relative quantification was performed post‐acquisition by normalization of auxin‐related compounds to SIL‐IAA in the agarose. Amounts of auxin‐related compounds were compared between genotypes to distinguish the effects of the mutations on the accumulation of indolic metabolites of interest.ResultsIAA added to agarose was found to remain stable, with repeatability and abundance features of IAA comparable with those of other compounds used in other methods for relative quantification in IR‐MALDESI analyses. Indole‐3‐acetaldoxime was increased in sur2 mutants compared with wild‐type and other mutants. Other auxin‐related metabolites were either below the limits of quantification or successfully quantified but showing little difference among mutants.ConclusionsAgarose was shown to be an appropriate sampling surface for IR‐MALDESI mass spectrometry imaging of Arabidopsis seedlings. SIL‐IAA doping of agarose was demonstrated as a viable technique for relative quantification of metabolites in live seedlings or tissues with similar biological considerations.
Practical optimization of liquid chromatography/mass spectrometry conditions and pretreatment methods toward the sensitive quantification of auxin in plants
Authors: Sugahara Kohtaro , Kitao Kazunori , Yamagaki Tohru , Koyama Tomotsugu 
Published: October 2019

RationaleThe plant hormone auxin, indole‐3‐acetic acid, regulates many aspects of plant growth and development. Auxin quantification should offer broad insights into its mechanistic action in plants. However, limited auxin content in plant tissues hampers the establishment of quantification methods without the highest graded instruments or deeply specialized experimental techniques.MethodsIn this study, we detailed optimized conditions for high‐performance liquid chromatography coupled with triple‐quadrupole mass spectrometry (LC/MS). We compared LC/MS conditions, such as columns, mobile phases, parameters of acquisition methods (selective or multiple ion monitoring), dwell times (DTs), and channel numbers, using differentially mixed authentic auxin and its related compounds. We further investigated pretreatment methods through the optimization of auxin recovery and irrelative compound removal from plant tissues prior to the LC/MS analysis.ResultsOur LC/MS analysis demonstrated the particular importance of the column, DTs, and channel numbers on detection sensitivity. Our comparative analysis developed optimal pretreatment methods, including the pulverization of plants, concentration of extract through centrifugal evaporation, and removal of irrelative metabolites using liquid–liquid extraction and a spin filter. We injected plant samples into our LC/MS system, quantified auxin and eight related compounds in a single measurement, and determined the auxin increase in an auxin over‐producing mutant.ConclusionsOur practical optimization of LC/MS conditions and pretreatment methods provides detailed experimental processes toward the sensitive quantification of auxin from 10 mg of plant tissue. These processes have not always been clearly documented; therefore, our protocol could broadly contribute to technical advances in plant growth and development research.
Methanogenic pathways and δ13C values from swine manure with a cavity ring‐down spectrometer: Ammonia cross‐interference and carbon isotope labeling
Authors: Dalby Frederik R. , Fuchs Andrea , Feilberg Anders 
Published: October 2019

RationaleCarbon isotope ratio analysis using cavity ring‐down spectroscopy (CRDS) offers insight into methanogenic activity. In livestock buildings, measuring 13CH4/12CH4 by CRDS is challenging and prone to errors, due to cross‐interference from NH3. Therefore, an interference‐corrected and improved approach to monitor methanogenic pathways with CRDS was developed and described in this study.MethodsCross‐interference from NH3 and other livestock gases on 13CH4/12CH4 was measured using CRDS. The removal efficiency of livestock gases was quantified using proton transfer reaction mass spectrometry. The linearity of the cavity ring‐down spectrometer was tested by dilution of a 13CH4 standard up to 15.6 atom % in CH4. 13C isotope‐labeled acetate was utilized to elucidate the methanogenic pathway contribution in swine manure using a stoichiometric model.ResultsSignificant NH3 cross‐interference on 13CH4/12CH4 was observed, and correction factors were calculated. Cross‐interfering gases were effectively removed using a copper scrubber and a Nafion tube. The instrument responded linearly with 13/12C ratios up to 7.6 atom % in CH4. Isotope‐labeled experiments suggested that hydrogenotrophic methanogenesis was dominant and acetate‐derived CH4 was limited in the studied swine manure. The observations were cross‐validated and consistent with measurements of the natural isotope signatures.ConclusionNH3 cross‐interference leads to major errors in isotope ratios and therefore in evaluating the relative methanogenic pathway activity. We present methodological approaches, which are crucial to apply in livestock‐related uses where NH3 is abundant. This methodology provides a considerable benefit to advance the understanding and reduction of methane emissions in the livestock sector.
Global decentralized sampled‐data output feedback stabilization for a class of large‐scale nonlinear systems with sensor and actuator failures
Authors: He Wenmin , Li Shi , Xiang Zhengrong 
Published: October 2019

SummaryIn this paper, we investigate global decentralized sampled‐data output feedback stabilization problem for a class of large‐scale nonlinear systems with time‐varying sensor and actuator failures. The considered systems include unknown time‐varying control coefficients and inherently nonlinear terms. Firstly, coordinate transformations are introduced with suitable scaling gains. Next, a reduced‐order observer is designed to estimate unmeasured states. Then, a decentralized sampled‐data fault‐tolerant control scheme is developed with an allowable sampling period. By constructing an appropriate Lyapunov function, it can be shown that all states of the resulting closed‐loop system are globally uniformly ultimately bounded. Finally, the validity of the proposed control approach is verified by using two examples.
An iterative approach for the discrete‐time dynamic control of Markov jump linear systems with partial information
Authors: Oliveira André Marcorin , Costa O. L. V. 
Published: October 2019

SummaryThe
,
and mixed
dynamic output feedback control of Markov jump linear systems in a partial observation context is studied through an iterative approach. By partial information, we mean that neither the state variable x(k) nor the Markov chain θ(k) are available to the controller. Instead, we assume that the controller relies only on an output y(k) and a measured variable
coming from a detector that provides the only information of the Markov chain θ(k). To solve the problem, we resort to an iterative method that starts with a state‐feedback controller and solves at each iteration a linear matrix inequality optimization problem. It is shown that this iterative algorithm yields to a nonincreasing sequence of upper bound costs so that it converges to a minimum value. The effectiveness of the iterative procedure is illustrated by means of two examples in which the conservatism between the upper bounds and actual costs is significantly reduced.
Interfacial Charge Transport in 1D TiO2 Based Photoelectrodes for Photoelectrochemical Water Splitting
Authors: Yu Zhongrui , Liu Haobo , Zhu Mingyuan , Li Ying , Li Wenxian 
Published: October 2019

Abstract1D nanostructured photoelectrodes are promising for application as photoelectrochemical (PEC) devices for solar energy conversion into hydrogen (H2) owing to the optical, structural, and electronic advantages. Titanium dioxide (TiO2) is the most investigated candidate as a photoelectrode due to its good photostability, low production cost, and eco‐friendliness. The obstacle for TiO2's practical application is the inherent wide bandgap (UV‐lights response), poor conductivity, and limited hole diffusion length. Here, a comprehensive review of the current research efforts toward the development of 1D TiO2 based photoelectrodes for heterogeneous PEC water splitting is provided along with a discussion of nanoarchitectures and energy band engineering influences on interfacial charge transfer and separation of 1D TiO2 composited with different dimensional photoactive materials. The key focus of this review is to understand the charge transfer processes at interfaces and the relationship between photogenerated charge separation and photoelectrochemical performance. It is anticipated that this review will afford enriched information on the rational designs of nanoarchitectures, doping, and heterojunction interfaces for 1D TiO2 based photoelectrodes to achieve highly efficient solar energy conversion.
When Silicon Materials Meet Natural Sources: Opportunities and Challenges for Low‐Cost Lithium Storage
Authors: Rehman Waheed Ur , Wang Haifeng , Manj Rana Zafar Abbas , Luo Wei , Yang Jianping 
Published: October 2019

AbstractThe manipulation of progressive lithium‐ion batteries (LIBs) with high energy density, low cost, and long‐term cycling stability is of high priority to meet the growing demands for next‐generation energy storage devices. Silicon (Si) has been receiving marvelous attention as a promising anode material for rechargeable LIBs, due to its high theoretical gravimetric capacity and low cost. Si is the second most abundant element in the earth crust in the form of silicates, so it is the most cost‐effective element as an anode material in next‐generation LIBs. In this review, different natural sources such as rice husk, sugar cane bagasse, bamboo, reed plant, sand, halloysite, and different waste sources such as waste of the solar power industry, fly ash, straw ash, and other industrial waste that can give rise to different nanostructured Si are systematically summarized. In addition, different synthesis methods of fabricating nanostructured Si are reviewed as well as including magnesiothermic reduction, etching methods, ball milling, and chemical vapor deposition. The advantages and disadvantages of these kind of synthesis methods are discussed as well. Furthermore, the opportunities and challenges of nano‐Si are also discussed.
Precursor‐Transformation Strategy Preparation of CuPx Nanodots–Decorated CoP3 Nanowires Hybrid Catalysts for Boosting pH‐Universal Electrocatalytic Hydrogen Evolution
Authors: Cheng Yu , Pei Yu , Zhuang Peiyuan , Chu Hang , Cao Yudong , Smith Will , Dong Pei , Shen Jianfeng , Ye Mingxin , Ajayan Pulickel M. 
Published: October 2019

AbstractThe development of earth‐abundant, low cost, and versatile electrocatalysts for producing hydrogen from water electrolysis is still challenging. Herein, based on high hydrogen evolution reaction (HER) activity of transition metal phosphides, a CoP3 nanowire decorated with copper phosphides (denoted as CuPx) nanodots structures synthesized through a simple and easily scalable precursor‐transformation strategy is reported as a highly efficient HER catalyst. By decorating with CuPx nanodots, the optimized CoP3 nanowires electrode exhibits excellent catalytic activity and long‐term durability for HER in alkaline conditions, achieving a low overpotential of 49.5 mV at a geometrical catalytic current density of 10 mA cm−2 with a small Tafel slope of 58.0 mV dec−1, while also performing quite well in neutral and acidic media. Moreover, its overall performance exceeds most of the reported state‐of‐the‐art catalysts, especially under high current density of 100 mA cm−2, demonstrating its potential as a promising versatile pH universal electrocatalyst for efficient water electrolysis. These results indicate that the incorporation of earth‐abundant stable element copper can significantly enhance catalytic activity, which widens the application range of copper and provides a new path for design and selection of HER catalysts.
Lornoxicam quantification in rabbit plasma by reverse phase HPLC: Optimization and application to pharmacokinetic study
Authors: Salunkhe Nitin , Jadhav Namdeo , Bhinge Somnath 
Published: October 2019

AbstractThe aim of present study was to develop a simple, rapid, selective, sensitive and robust reverse phase high‐performance liquid chromatography method for quantification of Lornoxicam and internal standard meloxicam in rabbit plasma at the wavelength of 370 nm. Protein was precipitated from rabbit plasma sample by addition of acetonitrile as a vehicle. An isocratic elution of samples was performed on capcell pak C8 column with the mobile phase consisting 5 mM phosphate buffer (pH 4.8): methanol (40:60 v/v) delivered at flow rate 1.0 mL min−1. The method was quantitatively evaluated in terms of System suitability, linearity, precision, recovery, selectivity, robustness and stability studies. The validated reverse phase high‐performance liquid chromatography method was successfully applied for the bioavailability studies of Lornoxicam. The pharmacokinetic parameters were calculated for all the investigated drugs in rabbit plasma after single‐dose administrations of pure drug and formulation of Lornoxicam. Thus, developed method is simple, convenient and suitable for the analysis of Lornoxicam in bulk drug and pharmaceutical formulations.
Prevalence and characterization of virulence genes in Escherichia coli isolated from piglets suffering post‐weaning diarrhoea in Shandong Province, China
Authors: Li Song , Wang Lei , Zhou Yufa , Miao Zengmin 
Published: October 2019

AbstractThe present study was performed to investigate the prevalence and characteristics of virulence genes in Escherichia coli (E. coli) isolated from piglets suffering post‐weaning diarrhoea (PWD) in Shandong Province, China. The standard bacteriological method was used to isolate and identify E. coli, and then multiplex polymerase chain reaction (mPCR) was performed to determine virulence genes in E. coli. Among the 300 isolates, 166 (55.3％) harboured at least one virulence gene. Among the 166 isolates, 155 (93.4％) contained toxin‐related genes. For enterotoxin genes, EAST1 (58/166, 34.9％) and LT‐I (45/166, 27.1％) were the most common, followed by STa (32/166, 19.3％) and STb (21/166, 12.7％); for pathogenicity island (PAI) genes, irp2 (49/166, 29.5％) was the most dominant, followed by eae (48/166, 28.9％); for Shiga toxigenic E. coli (STEC)‐associated toxin genes, Stx2e and hlyA genes were observed in 19 (19/166, 11.4％) and three strains (3/166, 1.8％) respectively. In addition, of the 166 isolates, 95 (95/166, 57.2％) contained adhesin genes, and AIDA‐I (33/166, 19.9％) was the most common, followed by paa (27/166, 16.3％), F5 (K99) (20/166, 12.0％), F18 (15/166, 9.0％) and F41 (12/166, 7.2％). In summary, these findings demonstrated the prevalence and characteristics of virulence factors in E. coli isolates from piglets with PWD in Shandong Province of China, and the data may be useful for establishing preventive measures for post‐weaning piglet diarrhoea.
3-Amidinophenylalanine-derived matriptase inhibitors can modulate hepcidin production in vitro
Authors: Pászti-Gere Erzsébet , Szombath Gergely , Gütschow Michael , Steinmetzer Torsten , Székács András 
Published: October 2019

AbstractMatriptase-2 (MT-2) is a type II transmembrane serine protease and predominantly attached to the surface of hepatocytes. MT-2 decreases the production of hepcidin, a key regulator of iron homeostasis. In this study, the effects of four 3-amidinophenylalanine-derived combined matriptase-1/matriptase-2 (MT-1/2) inhibitors (MI-432, MI-441, MI-460, and MI-461) on hepcidin production were investigated in hepatocyte mono- and hepatocyte-Kupffer cell co-cultures. In MI-461-treated cell cultures, the extracellular hydrogen peroxide contents and the interleukin-6 and -8 (IL-6 and IL-8) levels were determined and compared to controls. Hepcidin overproduction was observed in hepatocytes upon treatment with MI-432, MI-441 and MI-461 at 50 μM. In contrast, extracellular hydrogen peroxide levels were not elevated significantly after matriptase inhibition with MI-461. Furthermore, MI-461 did not induce increases in IL-6 and IL-8 levels in these hepatic models. A model of the binding mode of inhibitor MI-461 in complex with MT-2 revealed numerous polar contacts contributing to the nanomolar potency of this compound. Based on the in vitro data on hepcidin regulation, treatment with MI-461 might be valuable in pathological states of iron metabolism without causing excessive oxidative stress.
Dreijahresergebnisse der deutschlandweiten Umfrage zu Augenverletzungen durch Feuerwerkskörper
Authors:   Feuerwerks-Verletzungen-Studiengruppe, Gabel-Pfisterer A. , Böhringer D. , Agostini H. 
Published: October 2019

Zusammenfassung

Hintergrund
Weltweit entstehen an Feiertagen schwere Augenverletzungen durch Feuerwerkskörper. Die Datenlage für Deutschland ist bislang unklar.

Fragestellung
Wie häufig entstehen solche Verletzungen in Deutschland, wer ist gefährdet, wie schwer sind die Verletzungen, welche Therapien erfordern sie, und wie häufig treten Begleitverletzungen auf?

Methode
Deutschlandweite standardisierte Online-Umfrage an bettenführenden, notdienstleistenden Augenkliniken und Auswertung der Ergebnisse über 3 Jahre.

Ergebnisse
Die Beteiligung konnte von 2016 bis 2019 von 41 auf 51 Augenkliniken gesteigert werden. Von 1356 Patienten war mehr als ein Drittel (33–39 %) minderjährig, rund 60 % 25 Jahre oder jünger und rund 60 % Bystander. Ein Viertel der Verletzungen war schwer und erforderte eine stationäre Therapie. Begleitverletzungen am Partnerauge, an Händen und Gesicht waren bei Minderjährigen häufiger als bei Erwachsenen. Bulbusrupturen wurden bei 10 Kindern und 38 Erwachsenen dokumentiert.

Schlussfolgerungen
Vor allem Minderjährige und Zuschauer müssen besser geschützt werden.
Classification and examples of next generation machine elements
Authors: Vorwerk-Handing G. , Gwosch T. , Schork S. , Kirchner E. , Matthiesen S. 
Published: October 2019

AbstractIn order to fully exploit the potential of the rapidly progressing digitalisation of technical systems, it is necessary to provide reliable and significant process and condition related data. In this context, solutions are especially aspired to allow a simple integration into the surrounding system and to influence it as little as possible. The main challenges regarding the measurement of process and condition data in the operation and control of technical systems as well as in test environments are identified and presented at the beginning of this article. A promising approach to meet the resulting requirements is the integration of sensory functions into simple standardised machine elements. In order to facilitate the discussion and interdisciplinary development of machine elements with sensory functions, an extension of the existing classification of mechatronic machine elements is introduced and illustrated with examples. The introduced classification takes into account the classification according to Stücheli and Meboldt and is based on a comparison of conventional and mechatronic machine elements on a functional level with regard to the function structure. As a result, the three classessensor carrying machine elements,sensor integrating machine elementsandsensory utilizable machine elementsare introduced and subsequently discussed in more detail on the basis of examples. Finally, an outlook is given on the main research areas with regard to the development of mechatronic machine elements. Key aspects include working principles and effects for application in mechatronic machine elements, system analysis with regard to load conditions, power supply of sensor and data processor in the environment of the machine element as well as data processing and signal transmission under typical environmental conditions of mechanical engineering.
Assessment of in situ nest decay rate for chimpanzees (Pan troglodytes ellioti Matschie, 1914) in Mbam-Djerem National Park, Cameroon: implications for long-term monitoring
Authors: Kamgang Serge Alexis , Carme Tuneu Corral , Bobo Kadiri Serge , Abwe Ekwoge Enang , Gonder Mary Katherine , Sinsin Brice 
Published: October 2019

AbstractAccurate assessment of great ape populations is a prerequisite for conservation planning. Indirect survey methods using nest and dung, and a set of conversion parameters related to nest decay rates, are increasingly used. Most surveys use the standing crop nest count (SCNC) method, whereby nests are counted along transects and the estimated nest density is converted into chimpanzee density using an often non-local nest decay rate. The use of non-local decay rate is thought to introduce substantial bias to ape population estimates given that nest decay rates vary with location, season, rainfall, nest shape, and tree species used. SCNC method has previously been applied in Mbam-Djerem National Park (MDNP) in Cameroon, for chimpanzee surveys using a non-local nest decay rate. This current study aimed to measure a local nest decay rate for MDNP and implications for chimpanzee population estimates in the MDNP. The mean nest decay rate estimated using a logistic regression analysis was 127 [95% CI (100–160)] days. Moreover, the results suggested that rainfall strongly influenced the nest decay rate over the early stage of the lifetime of the nests. The study confirms that estimates of chimpanzee density and abundance using non-local decay rates should be treated with caution. Our research emphasized the importance of using local nest decay rates and other survey methods which do not depend on decay rates to obtain more accurate estimates of chimpanzee densities in order to inform conservation strategies of these great apes in MDNP.