bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of visible‐light photocatalytic degradation performance over nitrogen‐deficient g‐C3N4/KNbO3 heterojunction photocatalyst
Authors: Shi Weilong , Shu Keke , Huang Xiliu , Ren Hongji , Li Mingyang , Chen Fangyan , Guo Feng 
Published: January 2020

AbstractBACKGROUNDThe formation of heterojunction is an effective mean for increasing the photocatalytic activity of single‐phase semiconductor photocatalyst.RESULTSIn this report, KNbO3/N‐defected g‐C3N4 (KNO/CNx) composites were prepared by an impregnation heat method. The optimized photocatalyst 3% KNO/CNx possesses excellent photocatalytic activity (100 mL, 10 mg/L; 84% degradation within 120 min) in the degradation of tetracycline (TC) under visible light (λ > 420 nm), and it can reach about 125, 10.71 and 3.75 times the degradation kinetic constants, compared with KNO, CN, and CNx, respectively. Furthermore, 3% KNO/CNx possesses relatively high stability during the entire photoreaction process.CONCLUSIONThis enhanced photocatalytic activity of KNO/CNx is mainly ascribed to the synergistic effect between the heterojunction and defect engineering, which expand the visible‐light adsorption and accelerate the separation efficiency of photo‐induced electron–hole pairs. The research is expected to be used to improve the structure and properties of KNO‐based composites, which provides a possibility for practical application of environmental restoration. © 2020 Society of Chemical Industry
Efficient synthesis and In Silico study of some novel pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidine derivatives
Authors: Abdelrazek Fathy M. , Gomha Sobhi M. , Abdel‐aziz Hassan M. , Farghaly Mohamed S. , Metz Peter , Abdel‐Shafy Ahmed 
Published: January 2020

AbstractA novel series of 1,5‐dihydropyrido‐triazolo‐pyrimidine derivatives were prepared by cyclocondensation of 2‐thioxo‐pyrido[2,3‐d]pyrimidines (prepared from reaction of chalcone with 6‐aminothiouracil) with a variety of hydrazonoyl chlorides. Based on spectroscopic evidence and their chemical syntheses, the structures of the newly prepared compounds were elucidated. Designated compounds are forced for molecular docking by using MOE 2014.010 Package software; one of in silico study tools. Synthesized compounds are targeting Human Cyclin‐defendant Kinase 2 (CK2) PDB ID (1PXO.Protein data bank) due to its important role in controlling the human cell cycle and also for meiosis.
Updating the MEDALUS‐ESA Framework for Worldwide Land Degradation and Desertification Assessment
Authors: Ferrara Agostino , Kosmas Constantinos , Salvati Luca , Padula Antonietta , Mancino Giuseppe , Nolè Angelo 
Published: January 2020

AbstractThe environmentally sensitive area (ESA) methodology (originally proposed in the framework of MEDALUS–Mediterranean Desertification and Land Use—a series of international cooperation research projects funded by the European Union) is used worldwide to identify 'sensitive areas' that are potentially threatened by land degradation and desertification (LDD). The distinctive outcome of this approach is a multidimensional index (the ESA index) composed of partial indicators of climate, soil, vegetation, and management quality that are derived from the elaboration of 15 elementary variables. In this study, we propose (a) a major update of the ESA methodology, as presented in the MEDALUS project, for global LDD assessment, (b) a global map of ESAs to LDD, and (c) a global environmentally critical factors map. The results of the updated ESA framework confirm the efficiency and applicability of the ESA methodology in different worldwide areas, allowing for the harmonization of regional/country level studies and applications, and the more efficient use of global level datasets. In this study, we provide examples for analysis of LDD patterns and processes at a global level, as well as for identification of the main risk factors over time and space. Global‐ESA and global‐environmentally critical factors maps also support regional‐scale knowledge on LDD processes and sustainable land management practices for LDD mitigation. High‐resolution illustrative maps and other information are available on a dedicated website (http://web.unibas.it/global-esa/).
Identification of six novel variants in Waardenburg syndrome type II by next‐generation sequencing
Authors: Ren Shumin , Chen Xiaojie , Kong Xiangdong , Chen Yibing , Wu Qinghua , Jiao Zhihui , Shi Huirong 
Published: January 2020

AbstractBackgroundWaardenburg syndrome (WS) is a dominantly inherited, genetically heterogeneous auditory‐pigmentary syndrome characterized by nonprogressive sensorineural hearing loss and iris discoloration. This study aimed to investigate the underlying molecular pathology in Chinese WS families.MethodsA total of 13 patients with Waardenburg syndrome type II (WS2) from six unrelated Chinese families were enrolled. We investigated the mutation profile of genes related to congenital deafness in these families through a targeted sequencing technology and validated the candidate variants by Sanger sequencing.ResultsWe identified six novel variants in microphthalmia‐associated transcription factor (MITF) and SRY‐box 10 (SOX10), which were predicted to be disease causing by in silico analysis. Our results showed that mutations in SOX10 and MITF are two major causes of deafness associated with WS, and de novo mutations were frequently found in probands with SOX10 mutations but not in those with MITF mutations.ConclusionResults showed that targeted next‐generation sequencing (NGS) enabled us to detect disease‐causing mutations with high accuracy, stability, speed and throughput. Our study extends the pathogenic mutation spectrum of MITF and SOX10.
The earliest double dog deposit in the Palaeolithic record: The case of the Azilian level of Grotte‐abri du Moulin (Troubat, France)
Authors: Boudadi‐Maligne Myriam , Mallye Jean‐Baptiste , Ferrié Jean‐Georges , Costamagno Sandrine , Barshay‐Szmidt Carolyn , Deguilloux Marie‐France , Pémonge Marie‐Hélène , Barbaza Michel 
Published: January 2020

AbstractIt is now largely accepted that the wolf was the first animal to be domesticated during Pleistocene time. Although the exact timing of this event is still the subject of considerable debate, it is generally agreed upon that dogs lived side‐by‐side with humans for at least the last 15,000 years. Recent discoveries from the “Grotte‐abri du Moulin” (Troubat, France) provide crucial new information as to our understanding of the relationships between humans and dogs during prehistory. The site produced a deep stratigraphic sequence demonstrating that the cave was occupied from the Middle Magdalenian (ca. 17.5 ky cal BP) to the Sauveterrian period (ca. 9.5 ky cal BP). Faunal remains from layer 6, attributed to the Azilian culture, included a small Canis. The biometric study of these remains is fully consistent with their attribution to the dog (Canis familiaris). A total of 147 dog remains were isolated and represent a minimum of two individuals. These remains were recovered from a restricted space, and several skeletal elements remained in anatomical connection or in loose connection. The most labile elements were only slightly dispersed, and there is no evidence of human or carnivore modification on these bones. Direct radiocarbon dates obtained from a complete tibia demonstrate the dog remains to be contemporaneous with the Azilian occupation of the cave. The Grotte‐abri du Moulin evidence represents, therefore, the earliest known occurrence of an intentional double dog deposit and evidence for a particularly close relationship between Azilian groups and their dogs.
A Theoretical Study on the Fluorescence Signal Sensing of a colorimetric ClO‐ chemosensor
Authors: Bai Tianxin , Chu Tianshu 
Published: January 2020

AbstractDetection of reactive oxygen species by optical signal sensing is of great interesting to the chemical and medical world. In this paper, the fluorescence signal sensing process of a colorimetric ClO‐ chemosensor (S‐BODIPY) has been investigated through DFT/TDDFT calculations. The relative free energy (ΔG = 23.46 kcal/mol) suggests that the oxidation process of the chemosensor by the analyte would have a favorable reaction rate, accounting for a rapid response speed, and the large binding energy of 35.3 kcal/mol supports a good selectivity of the chemosensor for ClO‐. The calculated vertical excitation energies of S‐BODIPY (1.93 eV) and its oxidation product SO‐BODIPY (2.01 eV) agree well with the experimental emission data (2.00 and 2.11 eV, respectively). The absorption spectra and 1H NMR spectra have also been computed and analyzed showing reasonably good agreement with experimental ones. The fluorescence signal sensing mechanism is verified to be associated with the intramolecular charge transfer (ICT), that is, the relatively weak ICT process in SO‐BODIPY than that in S‐BODIPY has caused the observable blueshift in both the absorption and emission spectra after the detection of ClO‐.
Surface modification of calcium sulfate whisker using thiol‐ene click reaction and its application in reinforced silicone rubber
Authors: Chen Ying , Ding Yu , Dong Yajie , Liu Yuetao , Ren Xiu , Wang Bo , Gao Chuanhui 
Published: January 2020

AbstractThe hemihydrate calcium sulfate whisker (HCSW) was modified by γ‐(methacryloxy)propyl trimethoxy silane (KH570) and trimethylolpropane tris(3‐mercaptopropionate) via wet modification and thiol‐ene click reaction, and then the unmodified and modified HCSW were added into α, ω‐dihydroxy polysiloxane (DPS) matrix to prepare silicon rubber composites. After the dual‐surface modification, the surface of HCSW was transformed to hydrophobic, the hydration of whisker was obviously improved, and the whisker dispersed more evenly in the polymer. The mechanical properties, dynamic mechanical properties, and the medium resistance of the silicone rubber composite were compared. The tensile test shows that the silicone rubber shows better mechanical properties after adding the modified whiskers, among which HCSW‐KH570‐SH has the most significant reinforcement effect. Moreover, DPS/HCSW‐KH570‐SH shows the best medium resistance in toluene, gasoline, and water. The addition of modified whiskers can improve the storage modulus of silicone rubber significantly, while DMA and DSC show that the addition of modified whiskers can reduce the glass transition temperature of silicone rubber. The bound rubber indicates that the interface interaction between HCSW‐KH570‐SH and silicone rubber is the best.
Quantification of glyphosate and aminomethylphosphonic acid from microbiome reactor fluids
Authors: Fritz‐Wallace Katarina , Engelmann Beatrice , Krause Jannike L. , Schäpe Stephanie S. , Pöppe Judith , Herberth Gunda , Rösler Uwe , Jehmlich Nico , von Bergen Martin , Rolle‐Kampczyk Ulrike 
Published: January 2020

RationaleGlyphosate is one of the most widely used herbicides and it is suspected to affect the intestinal microbiota through inhibition of aromatic amino acid synthesis via the shikimate pathway. In vitro microbiome bioreactors are increasingly used as model systems to investigate effects on intestinal microbiota and consequently methods for the quantitation of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) in microbiome model systems are required.MethodsAn optimized protocol enables the analysis of both glyphosate and AMPA by simple extraction with methanol:acetonitrile:water (2:3:1) without further enrichment steps. Glyphosate and AMPA are separated by liquid chromatography on an amide column and identified and quantified with a targeted tandem mass spectrometry method using a QTRAP 5500 system (AB Sciex).ResultsOur method has a limit of detection (LOD) in extracted water samples of <2 ng/mL for both glyphosate and AMPA. In complex intestinal medium, the LOD is 2 and 5 ng/mL for glyphosate and AMPA, respectively. These LODs allow for measurement at exposure‐relevant concentrations. Glyphosate levels in a bioreactor model of porcine colon were determined and consequently it was verified whether AMPA was produced by porcine gut microbiota.ConclusionsThe method presented here allows quantitation of glyphosate and AMPA in complex bioreactor fluids and thus enables studies of the impact of glyphosate and its metabolism on intestinal microbiota. In addition, the extraction protocol is compatible with an untargeted metabolomics analysis, thus allowing one to look for other perturbations caused by glyphosate in the same sample.
Rapid quantification of tenofovir in umbilical cord plasma and amniotic fluid in hepatitis B mono‐infected pregnant women during labor by ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: Ma Zhiyuan , Li Siying , He Daqiang , Wang Yuqing , Jiang Huidi , Zhou Hui , Jin Jie , Lin Nengming 
Published: January 2020

RationaleTenofovir (TFV) is a first‐line antiviral agent against hepatitis B virus (HBV) and is recommended for the prevention of mother‐to‐infant transmission of HBV. To study the distribution of TFV in umbilical cord plasma and amniotic fluid of HBV‐infected pregnant women, a rapid and sensitive method for TFV determination was developed and validated.MethodsThe quantification method was developed using liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS). The analytes were separated on an Acquity UPLC HSS T3 column under gradient elution with methanol and 0.01% ammonia solution in 10 mM ammonium acetate/water. This is the first reported method for the determination of TFV using alkaline rather than acidic mobile phases. Linearity, accuracy, precision, limit of quantification, specificity and stability were assessed.ResultsDetection of TFV was achieved within 4 min. The calibration curves for TFV quantification showed excellent linearity in the range of 1–500 ng/mL. The intra‐ and interbatch precision and accuracy ranged from −4.35% to 6.92%. This method was successfully applied to determination of samples from 50 HBV mono‐infected women undergoing tenofovir disoproxil fumarate therapy. The mean concentrations of TFV in the umbilical cord and amniotic fluid samples were 29.2 (4.6–86) and 470.9 (156–902) ng/mL, respectively, which showed a moderate positive correlation (r = 0.5299, P<0.001).ConclusionsA simple, rapid but sensitive bioanalytical method to determine TFV concentration in both umbilical cord plasma and amniotic fluid using LC/MS/MS was developed and applied to HBV‐infected women during labor who were undergoing TDF therapy, which will help us understand the efficacy and safety of tenofovir during pregnancy.
Simulation of unidirectional ion ejection in linear ion traps with asymmetric radiofrequency voltage
Authors: Zhang Yingjun , Wu Haiyan , Rujiao Yao , Qian Jie , Ge Saijin , Ma Qiang , Bai Hua , Xiao Yu , Li Xiaoxu 
Published: January 2020

RationaleLinear ion traps with simplified structure have been widely used in miniaturized mass spectrometers. However, linear ion traps usually have low ion detection efficiency when used in a miniaturized mass spectrometer, in which only one ion detector can be installed. To solve this problem, an asymmetric radiofrequency (RF) voltage was applied to introduce asymmetric electric fields in the trapping volume of linear ion traps, which would lead to unidirectional ion ejection.MethodsAn asymmetric RF voltage was applied on both half‐round‐rod electrode and triangular electrode linear ion traps, and their performances including unidirectional ion ejection efficiency and mass resolution were evaluated using computer simulation. The relationship between asymmetric RF voltage difference δ and internal electric field distribution was investigated, and the impact of δ and resonance excitation signal frequency on the unidirectional ion ejection efficiency and mass resolution was also explored.ResultsA unidirectional ion ejection efficiency of around 83% and a mass resolution of over 2700 were achieved with δ = 7% in both half‐round‐rod electrode and triangular electrode linear ion traps.ConclusionsBy applying an asymmetric RF voltage, the ion detection efficiency could be significantly improved without any change to the structures of existing linear ion traps. This method provides a simple and general solution for improving the ion detection efficiency and sensitivity of miniaturized linear ion trap mass spectrometers.
Mordenite‐Type Zeolite from Waste Coal Fly Ash: Synthesis, Characterization and Its Application as a Sorbent in Metal Ions Removal
Authors: Lankapati Henilkumar M. , Lathiya Dharmesh R. , Choudhary Lalita , Dalai Ajay K. , Maheria Kalpana C. 
Published: January 2020

AbstractCoal fly ash is a waste, obtained from the combustion of coal in thermal power plants. Fly ash is harmful and its disposal is the major issue from an environmental point of view. As fly ash contains silica and alumina, it is thought of interest to use it for the synthesis of porous material like zeolite. In this work, the focus is on the utilization of fly ash for the synthesis of Mordenite type zeolite and its application in the toxic metals removal from aqueous solution. Coal fly ash based Mordenite type zeolite (FZSH) was synthesized by seed assisted hydrothermal synthetic method using fly ash as a source of silica and alumina instead of using pure silica and alumina. The resultant material was characterized by various techniques, such as SEM‐EDX, XRD, TGA, FT‐IR, solid state NMR, BET surface area, etc. The XRD patterns confirm the presence of Mordenite phase in the FZSH zeolite. The sorption behavior of Pb2+ and Cd2+ towards commercial Mordenite and FZSH Mordenite type zeolite is investigated and compared. Percentage uptake obtained using FZSH and commercial Mordenite zeolite sorbent was found quite similar. The kinetic and thermodynamic studies reveal the favourable and spontaneous nature of the sorption.
Dynamic Passivation in Perovskite Quantum Dots for Specific Ammonia Detection at Room Temperature
Authors: Huang Hui , Hao Mingwei , Song Yilong , Dang Song , Liu Xiaoting , Dong Qingfeng 
Published: January 2020

AbstractPerovskite structured CsPbX3 (X = Cl, Br, or I) quantum dots (QDs) have attracted considerable interest in the past few years due to their excellent optoelectronic properties. Surface passivation is one of the main pathways to optimize the optoelectrical performance of perovskite QDs, in which the amino group plays an important role for the corresponding interaction between lead and halide. In this work, it is found that ammonia gas could dramatically increase photoluminescence of purified QDs and effectively passivate surface defects of perovskite QDs introduced during purification, which is a reversible process. This phenomenon makes perovskite QDs a kind of ideal candidate for detection of ammonia gas at room temperature. This QD film sensor displays specific recognition behavior toward ammonia gas due to its significant fluorescence enhancement, while depressed luminescence in case of other gases. The sensor, in turn‐on mode, shows a wide detection range from 25 to 350 ppm with a limit of detection as low as 8.85 ppm. Meanwhile, a fast response time of ≈10 s is achieved, and the recovery time is ≈30 s. The fully reversible, high sensitivity and selectivity characteristics make CsPbBr3 QDs ideal active materials for room‐temperature ammonia sensing.
Über den Einfluss der Torsionssteifigkeit von Längssteifen bei Beulfeldern unter biaxialen Druckspannungen
Authors: Pourostad Vahid , Heidt Matthias , Knödel Peter , Kuhlmann Ulrike , Ummenhofer Thomas 
Published: January 2020

AbstractBei der Montage von Stahl‐ und Stahlverbundbrücken im Taktschiebeverfahren sind die schlanken Stegbleche des Überbaus temporär einer biaxialen Druckbeanspruchung ausgesetzt. Neben den Längsspannungen infolge des Biegemoments tritt am Verschublager gleichzeitig eine einseitige Querdruckbelastung auf, sodass der Bauzustand oft bemessungsrelevant wird. Für längsversteifte Stegbleche ist in Deutschland für eine analytisch gestützte Bemessung die Methode der reduzierten Spannungen nach DIN EN 1993‐1‐5 zu verwenden. Jüngere Untersuchungen hatten für den Fall einachsiger Druckbeanspruchungen festgestellt, dass das Nachweisformat für längsausgesteifte Beulfelder unter Berücksichtigung der Torsionssteifigkeit geschlossener Steifen bei der Bestimmung der kritischen Beulspannung zu unsicheren Ergebnissen führt. Deswegen wurde im November 2018 in den Nationalen Anhang zu DIN EN 1993‐1‐5 aufgenommen, dass die Torsionssteifigkeit in diesen Fällen zu vernachlässigen ist. Im Oktober 2019 wurde auch die Hauptnorm DIN EN 1993‐1‐5 entsprechend ergänzt. Im Rahmen einer Masterarbeit wurde in einer numerischen Parameterstudie untersucht, inwiefern sich die hohe Torsionssteifigkeit geschlossener Steifen gegenüber offenen Querschnitten auf die Versagenslast und ‐form eines Stegblechs unter mehrachsiger Druckbeanspruchung auswirkt. Die Traglasten aus der Parameterstudie werden herangezogen, um sie den Ergebnissen nach dem Verfahren aus DIN EN 1993‐1‐5 gegenüberzustellen und Empfehlungen für die Bemessung zu entwickeln.
Can Fluid Interaction Influence the Critical Mass for Taxis-Driven Blow-up in Bounded Planar Domains?
Authors: Winkler Michael 
Published: January 2020

AbstractIn a bounded planar domain $\varOmega $
Ω
with smooth boundary, the initial-boundary value problem of homogeneous Neumann type for the Keller-Segel-fluid system
$$\begin{aligned} \left \{ \textstyle\begin{array}{l@{\quad }l} n_{t} + \nabla \cdot (nu) = \Delta n - \nabla \cdot (n\nabla c), & x\in \varOmega , \ t>0, \\ 0 = \Delta c -c+n, & x\in \varOmega , \ t>0, \end{array}\displaystyle \right . \end{aligned}$$

{

n
t

+
∇
⋅
(
n
u
)
=
Δ
n
−
∇
⋅
(
n
∇
c
)
,

x
∈
Ω
,

t
>
0
,

0
=
Δ
c
−
c
+
n
,

x
∈
Ω
,

t
>
0
,

is considered, where $u$
u
is a given sufficiently smooth velocity field on $\overline {\varOmega }\times [0,\infty )$

Ω
‾

×
[
0
,
∞
)
that is tangential on $\partial \varOmega $
∂
Ω
but not necessarily solenoidal.It is firstly shown that for any choice of $n_{0}\in C^{0}(\overline {\varOmega })$

n
0

∈

C
0

(

Ω
‾

)
with $\int _{\varOmega}n_{0}<4\pi $

∫
Ω

n
0

<
4
π
, this problem admits a global classical solution with $n(\cdot ,0)=n_{0}$
n
(
⋅
,
0
)
=

n
0

, and that this solution is even bounded whenever $u$
u
is bounded and $\int _{\varOmega}n_{0}<2\pi $

∫
Ω

n
0

<
2
π
. Secondly, it is seen that for each $m>4\pi $
m
>
4
π
one can find a classical solution with $\int _{\varOmega}n(\cdot ,0)=m$

∫
Ω

n
(
⋅
,
0
)
=
m
which blows up in finite time, provided that $\varOmega $
Ω
satisfies a technical assumption requiring $\partial \varOmega $
∂
Ω
to contain a line segment.In particular, this indicates that the value $4\pi $
4
π
of the critical mass for the corresponding fluid-free Keller-Segel system is left unchanged by any fluid interaction of the considered type, thus marking a considerable contrast to a recent result revealing some fluid-induced increase of critical blow-up masses in a related Cauchy problem in the entire plane.