bluuebunny/crossref_metadata_2025 huggingface dataset:
Switching of dominant positions between two sand‐fixing shrub species during the dune revegetation process is underlain by their contrasting xylem hydraulics and water‐use strategies
Authors: Guo Jing‐Jing , Gong Xue‐Wei , Fang Li‐Dong , Jiang De‐Ming , Ala Musa , Bucci Sandra J. , Scholz Fabian G. , Goldstein Guillermo , Hao Guang‐You
Published: November 2019

Differences in key physiological characteristics between plant species can result in their contrasting performances in vegetation restoration projects, but ecophysiological comparative studies in close relation to ecological restoration projects are scarce. Hedysarum fruticosum Pall. and Caragana microphylla Lam. are two leguminous shrub species widely used in combination for fixation of active sand dunes in semiarid regions of northern China, but they clearly differ in fitness at different stages of dune vegetation development; that is, H. fruticosum quickly gains a community dominance at the initial stage but yields to C. microphylla in a few years after the fixation of dunes. To reveal the underlying mechanism of such a pattern, key physiological characteristics related to xylem water transport, leaf water use, and drought tolerance were compared between these two species at a typical site of sand dune fixation project in Inner Mongolia. Compared with C. microphylla, H. fruticosum shows an acquisitive and risky water management strategy with substantially higher hydraulic efficiency and photosynthetic capability but reduced resistance to drought‐induced xylem embolism, which endows it an advantage under conditions of relatively high soil water availability at the early stage of dune fixation. In contrast, C. microphylla exhibits more conservative water use and characteristics of greater drought tolerance, which results in greater dominance under the more drought‐stressed conditions of the later stage of dune fixation. Our study for the first time provides a potential mechanistic explanation for the clear switching of dominant positions between the two important sand‐fixing shrub species during the sand dune revegetation process.
The ecological role of bacterial seed endophytes associated with wild cabbage in the United Kingdom
Authors: Tyc Olaf , Putra Rocky , Gols Rieta , Harvey Jeffrey A. , Garbeva Paolina
Published: November 2019

Endophytic bacteria are known for their ability in promoting plant growth and defense against biotic and abiotic stress. However, very little is known about the microbial endophytes living in the spermosphere. Here, we isolated bacteria from the seeds of five different populations of wild cabbage (Brassica oleracea L) that grow within 15 km of each other along the Dorset coast in the UK. The seeds of each plant population contained a unique microbiome. Sequencing of the 16S rRNA genes revealed that these bacteria belong to three different phyla (Actinobacteria, Firmicutes, and Proteobacteria). Isolated endophytic bacteria were grown in monocultures or mixtures and the effects of bacterial volatile organic compounds (VOCs) on the growth and development on B. oleracea and on resistance against a insect herbivore was evaluated. Our results reveal that the VOCs emitted by the endophytic bacteria had a profound effect on plant development but only a minor effect on resistance against an herbivore of B. oleracea. Plants exposed to bacterial VOCs showed faster seed germination and seedling development. Furthermore, seed endophytic bacteria exhibited activity via volatiles against the plant pathogen F. culmorum. Hence, our results illustrate the ecological importance of the bacterial seed microbiome for host plant health and development.
A mechanically pattern reconfigurable array
Authors: Lee Yi‐Lung , Wang Po‐Kai , Chen Tsair‐Rong , Row Jeen‐Sheen
Published: November 2019

A design of pattern reconfigurable arrays realized with mechanical mechanism is presented. The radiating element of the array is a printed dipole backed with a metallic box, and it has a broad impedance bandwidth as well as a high front‐to‐back ratio. Four of the elements are connected together by using a mounting fixture with rotatable joints. When the joints are rotated manually, the array configuration is changed, and each array configuration can generate a specific radiation pattern. For the proposed array, a prototype designed at the frequency band from 4.8 to 5.9 GHz is constructed. Measured results for the prototype operating in three typical radiation modes are exhibited, including high‐directivity radiation mode, two‐beam radiation mode, and omnidirectional radiation mode. Simulated results also validate the experiments.
On the use of the absorbed depth‐dose measurements in the beam calibration of a surface electronic high‐dose‐rate brachytherapy unit, a Monte Carlo‐based study
Authors: Valdes‐Cortez Christian , Niatsetski Yury , Ballester Facundo , Vijande Javier , Candela‐Juan Cristian , Perez‐Calatayud Jose
Published: November 2019

Purpose

To evaluate the use of the absorbed depth‐dose as a surrogate of the half‐value layer in the calibration of a high‐dose‐rate electronic brachytherapy (eBT) equipment. The effect of the manufacturing tolerances and the absorbed depth‐dose measurement uncertainties in the calibration process are also addressed.

Methods

The eBT system Esteya® (Elekta Brachytherapy, Veenendaal, The Netherlands) has been chosen as a proof‐of‐concept to illustrate the feasibility of the proposed method, using its 10 mm diameter applicator. Two calibration protocols recommended by the AAPM (TG‐61) and the IAEA (TRS‐398) for low‐energy photon beams were evaluated. The required Monte Carlo (MC) simulations were carried out using PENELOPE2014. Several MC simulations were performed modifying the flattening filter thickness and the x‐ray tube potential, generating one absorbed depth‐dose curve and a complete set of parameters required in the beam calibration (i.e., HVL, backscatter factor (Bw), and mass energy‐absorption coefficient ratios (µen/ρ)water,air), for each configuration. Fits between each parameter and some absorbed dose‐ratios calculated from the absorbed depth‐dose curves were established. The effect of the manufacturing tolerances and the absorbed dose‐ratio uncertainties over the calibration process were evaluated by propagating their values over the fitting function, comparing the overall calibration uncertainties against reference values. We proposed four scenarios of uncertainty (from 0% to 10%) in the dose‐ratio determination to evaluate its effect in the calibration process.

Results

The manufacturing tolerance of the flattening filter (±0.035 mm) produces a change of 1.4% in the calculated HVL and a negligible effect over the Bw, (µen/ρ)water,air, and the overall calibration uncertainty. A potential variation of 14% of the electron energies due to manufacturing tolerances in the x‐ray tube (69.5 ± ~10 keV) generates a variation of 10% in the HVL. However, this change has a negligible effect over the Bw and (µen/ρ)water,air, adding 0.1% to the overall calibration uncertainty. The fitting functions reproduce the data with an uncertainty (k = 2) below 1%, 0.5%, and 0.4% for the HVL, Bw, and (µen/ρ)water,air, respectively. The four studied absorbed dose‐ratio uncertainty scenarios add, in the worst‐case scenario, 0.2% to the overall uncertainty of the calibration process.

Conclusions

This work shows the feasibility of using the absorbed depth‐dose curve in the calibration of an eBT system with minimal loss of precision.
Designing parallel transmit head coil arrays based on radiofrequency pulse performance
Authors: Cao Zhipeng , Yan Xinqiang , Gore John C. , Grissom William A.
Published: November 2019

Purpose

A new approach to design parallel transmit (pTx) head arrays is proposed that integrates transmit radiofrequency pulse designs with electromagnetic modeling of array coil elements.

Theory and Methods

An approach to design pTx head arrays is proposed that finds optimal groupings of a large number of coils into a small number of channels. An algorithm is proposed to extend array‐compressed parallel transmit pulse design by adding the ability to optimally select and prune coil elements, in addition to optimizing compression weights. The performance of the method is demonstrated in simulations of dynamic multislice shimming of the human brain in axial, coronal, and sagittal directions, and of reduced field‐of‐view excitation targeting the human occipital lobe, with simulated electromagnetic field maps from a group of 5 human head models at 7T.

Results

For both dynamic multislice shimming and reduced field‐of‐view excitation, the method successfully designed pTx arrays that simultaneously achieved in general 15% lower mean excitation errors with 20% lower SDs, along with 20% lower mean global averaged specific absorption rate and 50% lower SD than previously reported pTx head array designs.

Conclusion

With the proposed optimal coil element selection algorithm, the array‐compressed parallel transmit pulse design can be extended to design pTx transmit head arrays with joint consideration of the fields within the sample and the radiofrequency pulse. The pTx arrays from such an approach achieved higher transmit excitation accuracy, lower radiofrequency heating in subjects, and more robust performance across subjects compared with previously reported pTx head arrays with the same number of channels.
Safe guidewire visualization using the modes of a PTx transmit array MR system
Authors: Godinez Felipe , Scott Greig , Padormo Francesco , Hajnal Joseph V. , Malik Shaihan J.
Published: November 2019

Purpose

MRI‐guided cardiovascular intervention using standard metal guidewires can produce focal tissue heating caused by induced radiofrequency guidewire currents. It has been shown that safe operation is made possible by using parallel transmit radiofrequency coils driven in the null current mode, which does not induce radiofrequency currents and hence allows safe tissue visualization. We propose that the maximum current modes, usually considered unsafe, be used at very low power levels to visualize conductive wires, and we investigate pulse sequences best suited for this application.

Methods

Spoiled gradient echo, balanced steady‐state free precession, and turbo spin echo sequences were evaluated for their ability to visualize a conductive guidewire embedded in a gel phantom when run in maximum current modes at very low power level. Temperature at the guidewire tip was monitored for safety assessment.

Results

Excellent guidewire visualization could be achieved using maximum current modes excitation, with the turbo spin echo sequence giving the best image quality. Although turbo spin echo is usually considered to be a high‐power sequence, our method reduced all pulses to 1% amplitude (0.01% power), and heating was not detected. In addition, visualization of background tissue can be achieved using null current mode, also with no recorded heating at the guidewire tip even when running at 100% (reported) specific absorption rate.

Conclusion

Parallel transmit is a promising approach for both guidewire and tissue visualization using maximum and null current modes, respectively, for interventional cardiac MRI. Such systems can switch excitation mode instantaneously, allowing for flexible integration into interactive sequences.
Core‐sheath structured TiO2@PVDF/PAN electrospun membranes for photocatalysis and oil‐water separation
Authors: Sun Fei , Huang Shih‐Yu , Ren Hai‐Tao , Li Ting‐Ting , Zhang Yue , Lou Ching‐Wen , Lin Jia‐Horng
Published: November 2019

This study uses PVDF, PAN, and coaxial electrospinning technique to build a core‐sheath structure for TiO2@PVDF/PAN electrospun membranes. The resulting electrospun membranes are compared with traditional electrospun membranes in terms of photocatalysis and oil‐water separation, which examines the influences of electrospinning fibrous structure. The test results show that the core‐sheath structure provides TiO2@PVDF/PAN electrospun membranes with a large diameter, high strength, a rough surface, a high photocatalysis, and good oil‐water separation. With PVDF as the sheath and PAN as the core, TiO2@PVDF/PAN electrospun membranes have a maximum strength of 8.96 MPa and exhibit 97% of rhodamine B pollutant after the exposure to the UV light. Moreover, the oil‐water separation rate is 99% and an oil flux is 40 163.79 L·m2·h−1, and the membrane maintains a high flux after 10 cycles, which makes TiO2@PVDF/PAN electrospun membranes an important candidate for treating wastewater produced in industry and daily life.
Stability of memory SuperAgers over 3 years
Authors: Červenková Markéta , Heissler Radek , Kopeček Miloslav
Published: November 2019

Some people aged 80 years and older are “memory SuperAgers” (SAs), that is, they have the episodic memory of a sexagenarian. In a sample of 208 non‐demented adults, we found that 12% were SAs. A total of 101 participants completed the 4‐year study; of this subsample, 10.9% were stable SAs and 61.3% stable non‐SAs across all assessments. The SA phenotype is conducive to further research.
Exome sequencing for perinatal phenotypes: The significance of deep phenotyping
Authors: Aggarwal Shagun , Vineeth Venugopal Satidevi , Das Bhowmik Aneek , Tandon Ashwani , Kulkarni Aditya , Narayanan Dhanya Lakshmi , Bhattacherjee Amrita , Dalal Ashwin
Published: November 2019

Objective

To ascertain the performance of exome sequencing (ES) technology for determining the etiological basis of abnormal perinatal phenotypes and to study the impact of comprehensive phenotyping on variant prioritization.

Methods

A carefully selected cohort of 32/204 fetuses with abnormal perinatal phenotypes following postmortem/postnatal deep phenotyping underwent ES to identify a causative variant for the fetal phenotype. A retrospective comparative analysis of the prenatal versus postmortem/postnatal phenotype–based variant prioritization was performed with aid of Phenolyzer software. A review of selected literature reports was done to examine the completeness of phenotypic information for cases in those reports and how it impacted the performance of fetal ES.

Results

In 18/32 (56%) fetuses, a pathogenic/likely pathogenic variant was identified. This included novel genotype‐phenotype associations, expanded prenatal phenotypes of known Mendelian disorders and dual Mendelian diagnoses. The retrospective analysis revealed that the putative diagnostic variant could not be identified on basis of prenatal findings alone in 15/22 (68%) cases, indicating the importance of comprehensive postmortem/postnatal phenotype information. Literature review was supportive of these findings but could not be conclusive due to marked heterogeneity of involved studies.

Conclusion

Comprehensive phenotyping is essential for improving diagnostic performance and facilitating identification of novel genotype‐phenotype associations in perinatal cohorts undergoing ES.
Utility of a Reverse Phase Protein Array to Evaluate Multiple Biomarkers in Diffuse Large B‐Cell Lymphoma
Authors: Suzuki Masaki , Muroi Atsushi , Nojima Masanori , Numata Ayumi , Takasaki Hirotaka , Sakai Rika , Yokose Tomoyuki , Miyagi Yohei , Koshikawa Naohiko
Published: November 2019

Purpose

Diffuse large B‐cell lymphoma (DLBCL), the most common non‐Hodgkin lymphoma, is a heterogeneous lymphoma with different clinical manifestations and molecular alterations, and several markers are currently being measured routinely for its diagnosis, subtyping, or prognostication by immunohistochemistry (IHC). Here, the utility of a reverse‐phase‐protein‐array (RPPA) as a novel supportive tool to measure multiple biomarkers for DLBCL diagnosis is validated.

Experimental design

The expression of seven markers (CD5, CD10, BCL2, BCL6, MUM1, Ki‐67, and C‐MYC) is analyzed by RPPA and IHC using 37 DLBCL tissues, and the correlation between the two methods is determined. To normalize tumor content ratio in the tissues, the raw RPPA values of each marker are adjusted by that of CD20 or PAX‐5.

Results

The CD20‐adjusted data for CD5, MUM1, BCL2, Ki‐67, and C‐MYC has better correlation with IHC results than PAX‐5‐adjusted data. Receiver operating characteristic (ROC) analysis reveals that CD5, MUM1, BCL2, and C‐MYC exhibit a better sensitivity and specificity >0.750. Furthermore, the CD20‐adjusted C‐MYC value strongly correlates with that of IHC, and has a particularly high specificity (0.882).

Conclusions and clinical relevance

Although further investigation using a large number of DLBCL specimens needs to be conducted, these results suggest that RPPA could be applicable as a supportive tool for determining lymphoma prognosis.
Complete synthesis of the bicyclic ring of a mutacin analog with orthogonally protected lanthionine via solid‐phase intracyclization
Authors: Kirichenko Kostyantyn , Hillman Jeffrey D. , Handfield Martin , Park Jae H.
Published: November 2019

Mutacin 1140 (MU1140) is a naturally occurring lantibiotic derived from posttranslational modifications of a ribosomally synthesized peptide during the fermentation of a bacterium called Streptococcus mutans, the etiological agent of dental cavities. A practical approach for chemically synthesizing lantibiotics would be a valuable tool to expand the MU1140 library with additional semisynthetic analogs. In turn, an expanded library may prove useful to explore additional therapeutic indications for this pipeline of novel compounds. In this work, orthogonally protected lanthionine analogs were synthesized via an aziridine ring opening strategy. This lanthionine was utilized to synthesize a cysteamine (Cya) instead of the (S)‐aminovinyl‐D‐cysteine (AviCys) that is naturally found in MU1140. The Cya containing bicyclic C/D ring of MU1140 was synthesized by Fmoc solid‐phase peptide synthesis (SPPS). The linear peptides were synthesized using OPfp ester derivatives and using various common coupling reagents such as COMU and TCTU. The linear peptide was intracyclized with DEPBT to construct the so‐called bicyclic ring C/D. This is the first report on the complete chemical synthesis of the bicyclic C/D ring of a MU1140 analog using orthogonally protected lanthionines using SPPS.
The impact of student financial aid reforms on leaving home: Evidence from the Netherlands
Authors: van den Berg Lonneke
Published: November 2019

To save costs, young adults may delay leaving the parental home in times of welfare cuts. However, although the impact of student financial aid reforms on educational decisions has received considerable attention in previous research, the impact on leaving home has not previously been studied. Using register data, this study investigates how recent student aid reforms in the Netherlands have impacted students' home‐leaving decisions. Event history models suggest that students who started studying after the reforms are substantially less likely to leave the parental home than students who began studying before the reforms. These findings underline the importance of the family for support: The family tends to take over when state support declines. The findings for income patterns are mixed. The decrease is greater for low‐income students relative to middle‐income students, whereas there is no difference in the effect of the reforms between low‐income and high‐income students.
Airmass analysis of the processes driving the progression of the Indian summer monsoon
Authors: Volonté A. , Turner A.G. , Menon A.
Published: November 2019

The Indian summer monsoon is a vital source of water and a cause of severe impacts for more than a billion people in the Indian subcontinent. The INCOMPASS project investigates the mechanisms driving its onset and progression through an observational field campaign supplemented by high‐resolution numerical simulations for the 2016 season using UK Met Office models. A 4.4 km resolution convection‐permitting limited‐area model simulation (driven at its boundaries by a daily‐initialised global model) is used in this study, and verified against observations, along with short‐lead‐time operational global forecasts. These data show that the monsoon progression towards northwest India in June 2016 is a non‐steady process, modulated by the interaction between moist low‐level southwesterly flow from the Arabian Sea and a northwesterly incursion of descending dry air from western and central Asia. The location and extent of these two flows are closely linked to midlatitude dynamics, through the southward propagation of potential vorticity streamers and the associated formation of cyclonic circulations in the region where the two airmasses interact. Particular focus is devoted to the use of Lagrangian trajectories to characterise the evolution of the airstreams and complement the Eulerian monsoon progression analysis. The trajectories confirm that the interaction of the two airstreams is a primary driver of the general moistening of the troposphere associated with monsoon progression. They also indicate the occurrence of local diabatic processes along the airstreams, such as turbulent mixing and local evaporation from the Arabian Sea, in addition to moisture transport from remote sources. In summary, this combined Eulerian–Lagrangian analysis reveals the non‐steady nature of monsoon progression towards northwest India. This process is driven by the interaction of different airmasses and influenced by a synergy of factors on a variety of scales, such as midlatitude dynamics, transient weather systems and local diabatic processes.
Metabolomics of soybean green stem and foliar retention (GSFR) disease using mass spectrometry and molecular networking
Authors: Zanzarin Daniele Maria , Hernandes Carolina Parcero , Leme Luiza Mariano , Silva Evandro , Porto Carla , Martin do Prado Rodolpho , Meyer Mauricio C. , Favoreto Luciany , Nunes Estela de Oliveira , Pilau Eduardo Jorge
Published: November 2019

Rationale

The nematode Aphelenchoides besseyi is the causal agent of green stem and foliar retention, a soybean disease recently described in Brazil. This condition can reduce soybean yield by up to 100%. However, little is known about chemical interactions between the plant and pathogen. Therefore, this work aimed to investigate metabolites from healthy soybean roots and from soybean roots that were inoculated with A. besseyi.

Methods

A. besseyi were multiplied in vitro with Fusarium sp. colonies in Petri dishes for 25 days, and were axenically inoculated into hydroponics healthy soybean plants. The metabolites were extracted from the roots of healthy and A. besseyi‐infected plants 16 days post‐inoculation. These extracts were analyzed using an untargeted metabolomic method with an ultra‐high‐performance liquid chromatography/electrospray ionization /tandem mass spectrometry (UHPLC/ESI‐MS/MS) and molecular networking approach.

Results

Roots from infected plants showed morphological alterations such as shrinkage, darkening, and arching. Similarly, they also showed an increased presence of flavonoids, compared with healthy roots. Compounds such as neobavaisoflavone, glycitin, genistin, and genistein were putatively identified and had greater intensity in inoculated roots. These compounds are linked to the defensive mechanisms in plants against nematodes. Moreover, coumaric acid, also exclusively putatively identified in inoculated roots, shows activity related to inhibition of root growth.

Conclusions

Liquid chromatography, mass spectrometry, and molecular networking approaches proved to be a powerful tool for the metabolomic study of GSFR. This study showed metabolomics differences of protective substances in the roots, evidencing a quick response of the plant to the attack of A. besseyi.
Automated Scoring of Students’ Use of Text Evidence in Writing
Authors: Correnti Richard , Matsumura Lindsay Clare , Wang Elaine , Litman Diane , Rahimi Zahra , Kisa Zahid
Published: November 2019

Despite the importance of analytic text‐based writing, relatively little is known about how to teach to this important skill. A persistent barrier to conducting research that would provide insight on best practices for teaching this form of writing is a lack of outcome measures that assess students’ analytic text‐based writing development and that are feasible to implement at scale. Automated essay‐scoring (AES) technologies offer one potential approach to increasing the feasibility of research in this area, provided that the scores yield information about substantive dimensions of writing aligned to new standards and are sensitive to variation in literacy instruction. The authors describe an approach to using AES technologies to provide information about students’ skills at marshaling text evidence in the upper elementary grades. Specifically, the authors examined 1,529 responses to a response‐to‐text assessment (RTA) from 65 fifth‐ and sixth‐grade language arts classrooms, from which the authors also collected data on instruction via logs, text‐based writing assignments, and surveys. Through correlational, univariate, and multilevel multivariate analyses, the authors found validity evidence supporting automated scoring of the RTA: The authors found close correspondence of human and AES scores, alignment of AES scores with components of instruction that the authors expected would predict variation in students’ writing quality, and association between AES scores and other expected measures of student achievement. These findings provide encouraging evidence that AES technologies as applied to the RTA can generate valid inferences about students’ ability to marshal text evidence in writing and, thus, could be a useful tool for advancing large‐scale writing research.
Functionalized Truxene Scaffold: A Promising Advanced Organic Material for Digital Era
Authors: Wagay Shafieq Ahmad , Rather Ishfaq Ahmad , Ali Rashid
Published: November 2019

Truxene and its congeners due to its structural, thermal, and optoelectronic properties, has recently became important not only in biological systems but also in the field of material and environmental sciences. The remarkable scope and its applicability ranging from sensory materials to photocatalysts and fluorescent probes, forces the scientific community to think about the design and construction of architecturally simple yet much powerful novel functional materials possessing the truxene scaffold(s) in their structures. Herein, we have focused to assemble a series of ground‐breaking achievements in recent years of truxene‐based functional materials with special emphasis on their applicability in material sciences and technology. We hope that the present review will boost the current scenario of truxene and its various domains.
Conversion of the Nitro Group to the Nitroso in Aromatic Compounds: Case of p‐Nitrophenol Using the Catalytic Effect of Palladium
Authors: Lahrich Sara , Hrioua Asmaa , Laghrib Fathellah , Hafdi Houyem , Bouzidi Abdelhamid , Bakasse Mina , Abderrahim El Mhammedi Moulay
Published: November 2019

In this study, a simple approach such as the electrodeposition of palladium on carbon paste electrode (CPE) can be used with success to catalyze the reduction of p‐Nitrophenol (p‐NP). The electrodeposition procedure was carried out using cyclic voltammetry in acidic media. All parameters that influence the shift and the current intensity of the cathodic peak of p‐NP were optimized. Interestingly, Pd/CPE can catalyze the reduction of p‐NP to intermediate nitroso derivative. Electrocatalytic behavior at Pd/CPE toward p‐NP reduction was evaluated using the cyclic voltammetry, linear voltammetry, and differential pulse voltammetry, always following the concentration‐dependent current variance to confirm that the peak under study corresponds to the p‐NP reduction. Moreover, the catalytic activity of the Pd/CPE toward p‐NP reduction was also investigated during the electrolysis process. All results showing that palladium modified carbon paste electrode is considered a high catalyst for p‐NP reduction, with a satisfactory ability to detect it in aqueous media.
Approach to Artificial Nucleosides from Glycoside Isothiocyanates: Synthesis of Original N‐Glycosylated Heterostructures by Cyclocondensation Reactions
Authors: Grosjean Sylvain , Julienne Karine , Gouin Sébastien G. , Deniaud David
Published: November 2019

Unusual purine nucleoside analogues were synthesized, using the well‐tried methodology in heterocyclic chemistry. This result expands the scope of accessible N‐glycosylated heterocyclic structures. Pyrimidine, and bicyclic pyrimido[1,2‐a]pyrimidine nucleoside analogues were prepared from common glycoside isothiocyanate precursors. Key cyclization steps were all based on a cyclocondensation reaction involving an activated heterodienic chain. Finally, thirteen pyrimido[1.2‐a]pyrimidine nucleoside analogues 13 a‐m were synthesized with a 30% yield on average, over 8 or 9 steps from one of the isothiocyanates 4 a‐c. These elaborated targets were fully characterized.
A Unique Single‐Ion Mediation Approach for Crossover‐Free Nonaqueous Redox Flow Batteries with a Na+‐Ion Solid Electrolyte
Authors: Yu Xingwen , Yu Wiley A. , Manthiram Arumugam
Published: November 2019

Nonaqueous redox flow batteries (RFBs) provide significant advantages over aqueous RFBs because the use of nonaqueous electrolytes offers the possibilities of operating RFBs at higher voltages (above the water break‐down voltage) and low temperatures (below 0 °C, the freezing point of H2O). However, the advancement of RFBs has long been plagued by the chemical‐crossover problem due to a lack of reliable separators. Herein, a single‐ion mediation strategy is presented for the advancement of nonaqueous RFBs by employing a Na+‐ion solid electrolyte. The catholyte and anolyte in a single cell are physically and electrically separated, but the redox reactions at the cathode and anode are ionically linked by sodium ions, which shuttle between the catholyte and anolyte through the solid electrolyte. To accommodate the mediating Na+‐ions, both the catholyte and anolyte are well managed through the addition of appropriate supporting electrolytes. The proposed unique RFB concept is validated with a chromium (III) acetylacetonate symmetric redox chemistry and the nitrobenzene–bromine redox couple.
Modelling and simulation of the behavior of a shape memory membrane for programmable matter 4D prototyping
Authors: Ennaji Mohamed , Tayane Souad , Gaber Jaafar
Published: November 2019

In almost all areas of the industry and more generally in the sector of development of manufacturing products, the realization of the product passes through several successive stages going from the design to the realization of the product. The most critical phase is prototyping because it is at this point that usually the most important decisions are made.

In several sectors this step is very expensive, and in any case, the prototype undergoes several modifications and requires several validations before it is definitive for the transition to production. The prototype must generally constitute a model of the product that has all or part of the technical qualities and operating characteristics that must appear in the final product, to demonstrate or affirm the validity of the concept and thus its final validation, which increases the overall cost of the prototyping phase. In the vast majority of prototyping devices available for the moment, be it by additive or subtractive process, the realization of the prototype requires a lot of time, and once the prototype is made, it can only be modified by destructive techniques because the materials used are frozen and do not allow easy reuse.

This study proposes a device for the prototyping of product, allowing a modification of the geometry of the prototype by means of a deformable composite membrane with shape memory, reusable and programmable. The device in question consists of a flexible composite membrane whose matrix is a flexible polymer, and the reinforcement is a shape‐memory alloy fibre and rubber effect, having a given electrical resistance. These shape memory fibres are woven in such a way as to ensure deformations in the direction normal to the plane of the membrane by injecting the current into each fibre. This is ensured by a cross weave allowing the control of the direction of the overall deformation through the deformation specific to each fibre. In this research work, we present the results of the modelling and simulation of the behaviour of a composite membrane with shape memory.
Tissue repair brakes: A common paradigm in the biology of regeneration
Authors: Cigliola Valentina , Ghila Luiza , Chera Simona , Herrera Pedro L.
Published: November 2019

To date, most attention on tissue regeneration has focused on the exploration of positive cues promoting or allowing the engagement of natural cellular restoration upon injury. In contrast, the signals fostering cell identity maintenance in the vertebrate body have been poorly investigated; yet they are crucial, for their counteraction could become a powerful method to induce and modulate regeneration. Here we review the mechanisms inhibiting pro-regenerative spontaneous adaptive cell responses in different model organisms and organs. The pharmacological or genetic/epigenetic modulation of such regenerative brakes could release a dormant but innate adaptive competence of certain cell types and therefore boost tissue regeneration in different situations.
Climate risk assessments and science‐based targets: A review of emerging private sector climate action tools
Authors: Walenta Jayme
Published: November 2019

With the retreat of the United States from the Paris Climate Agreement, the campaign to enroll corporations and other private sector actors into the climate governing arena has accelerated. The tools used by such actors in addressing climate change are similarly expanding. While carbon footprints and carbon offsets have been previously underscored as the chief climate action tools to date, climate risk assessments and science‐based targets have been proposed as new quantitative tools to mobilize corporate action against climate change. This article presents a review of these two tools, arguing for more comprehensive and sustained scholarly investigation into each. Following overviews on the early developments of each tool, related academic research is considered in an effort to point toward future research priorities. These priorities emphasize generating empirical data around each tool's origins, diffusion, and impacts (social, economic, and environmental) so that more robust academic debates might occur on the role of science‐based targets and climate risk assessments in advancing effective polycentric climate governance.

This article is categorized under:

Social Status of Climate Change Knowledge > Knowledge and Practice

Policy and Governance > Private Governance of Climate Change
Wind shear estimation model using load measurement of wind turbine tower and surrogate model
Authors: Namura Nobuo
Published: November 2019

A wind shear estimation method based on fore‐aft moment is proposed to estimate wind shear strength without a Doppler lidar. We construct wind shear estimation models (WSEMs) using surrogate models whose input is the time‐averaged fore‐aft moment and various supervisory control and data acquisition (SCADA) system data. Learning data for the WSEMs are generated by numerical simulation or field measurement of a real turbine using SCADA, strain gauges, and Doppler lidar. By using simulation data, we construct 20 WSEMs with various input combinations and surrogate methods to select a model with the highest accuracy. The best WSEM is constructed with the universal Kriging surrogate model and uses the fore‐aft moment and wind speed as its input. Subsequently, the best WSEM is applied to a real turbine to validate its accuracy in real wind conditions, and we confirm that the WSEM has reasonable accuracy. However, the estimation error in the real wind condition is about twice as high as that in the simulation due to the real wind shear not completely corresponding to the assumed wind profile and a large yaw error. Further improvement in wind shear estimation accuracy will be achieved by adding yaw error and turbulence intensity to the input variables and applying the WSEM to wind farms on simple terrain or offshore wind farms where wind profile error decreases.
Increase in the annual energy production due to a retrofit of vortex generators on blades
Authors: Skrzypiński Witold , Gaunaa Mac , Bak Christian , Junker Birgit , Brønnum Niels Bruhn , Kruse Emil Krog
Published: November 2019

The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch‐regulated, megawatt‐sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs. The work included a full‐scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3%, being satisfactorily close to the average 2.8% predicted by the present engineering tool.
Low‐E extension of a hand‐held Compton spectrometer
Authors: Derrien Jonathan , Tondeur François , Berrendorf Christopher , Gerardy Isabelle
Published: November 2019

The MICOS Compton spectrometer is a tool for the routine spectrometric control of X‐ray generators, mainly in the medical field (<150 kV). The use of a pen‐type NaI (Tl) detector with thin Be window allows to extend its range down to 6 keV, for a better evaluation of the low‐E side of the spectrum, which is determined by filtration. A specific problem is encountered in the deconvolution of the spectrum at very low energies, dominated by the K escape of iodine. The proposed solution combines an approximate step‐by‐step application of the GRAVEL algorithm, whereas the MAXED unfolding software is used for reaching the final solution. A new computer code was developed that combines spectrum acquisition and deconvolution and calculates the main characteristics of the source spectrum: end point energy, mean energy, energy at 50% of the left slope, and air kerma at 1 m from the source.
Single Crystals of CaNa[ReO4]3: Serendipitous Formation and Systematic Characterization
Authors: Conrad Maurice , Schleid Thomas
Published: November 2019

In an attempt to crystallize Ce[ReO4]4·xH2O from aqueous solutions of equimolar amounts of Ce[SO4]2 and Ba[ReO4]2 via salt‐metathesis the serendipitous formation of colorless, transparent, rod‐shaped single crystals of CaNa[ReO4]3 was observed as a result of calcium and sodium impurities within the improperly deionized water used. Structure analysis by X‐ray diffraction lead to the conclusion that the title compound crystallizes in the ThCd[MoO4]3 structure type with the hexagonal space group P63/m and the lattice parameters a = 991.74(6) pm, c = 636.53(4) pm, c/a = 0.642 for Z = 2. The crystal structure contains purely oxygen surrounded and crystallographically unique cations, namely Ca2+ in tricapped trigonal prismatic (d(Ca–O) = 6 × 249 pm + 3 × 254 pm), Na+ in octahedral (d(Na–O) = 6 × 241 pm), and Re7+ in tetrahedral coordination (d(Re–O) = 171–173 pm). Furthermore, it was possible to yield an almost phase‐pure microcrystalline powder of the title compound from a melt of equimolar amounts of Na[ReO4] and Ca[ReO4]2 stemming from aquatically obtained precursors.
Knockout of the non-essential gene SUGCT creates diet-linked, age-related microbiome disbalance with a diabetes-like metabolic syndrome phenotype
Authors: Niska-Blakie Joanna , Gopinathan Lakshmi , Low Kia Ngee , Kien Yang Lay , Goh Christine M. F. , Caldez Matias J. , Pfeiffenberger Elisabeth , Jones Oliver S. , Ong Chee Bing , Kurochkin Igor V. , Coppola Vincenzo , Tessarollo Lino , Choi Hyungwon , Kanagasundaram Yoganathan , Eisenhaber Frank , Maurer-Stroh Sebastian , Kaldis Philipp
Published: November 2019

SUGCT (C7orf10) is a mitochondrial enzyme that synthesizes glutaryl-CoA from glutarate in tryptophan and lysine catabolism, but it has not been studied in vivo. Although mutations in Sugct lead to Glutaric Aciduria Type 3 disease in humans, patients remain largely asymptomatic despite high levels of glutarate in the urine. To study the disease mechanism, we generated SugctKO mice and uncovered imbalanced lipid and acylcarnitine metabolism in kidney in addition to changes in the gut microbiome. After SugctKO mice were treated with antibiotics, metabolites were comparable to WT, indicating that the microbiome affects metabolism in SugctKO mice. SUGCT loss of function contributes to gut microbiota dysbiosis, leading to age-dependent pathological changes in kidney, liver, and adipose tissue. This is associated with an obesity-related phenotype that is accompanied by lipid accumulation in kidney and liver, as well as “crown-like” structures in adipocytes. Furthermore, we show that the SugctKO kidney pathology is accelerated and exacerbated by a high-lysine diet. Our study highlights the importance of non-essential genes with no readily detectable early phenotype, but with substantial contributions to the development of age-related pathologies, which result from an interplay between genetic background, microbiome, and diet in the health of mammals.
Quantitative evaluation of the progressive wear of powered interproximal reduction systems after repeated use
Authors: Livas C. , Baumann T. , Flury S. , Pandis N.
Published: November 2019

Purpose

To evaluate the residual surface roughness of 5 common diamond-coated interproximal reduction (IPR) systems after consecutive in vitro applications in relation to system, diamond grain size, and instrument thickness.

Methods

IPR was performed on 80 extracted human incisors using motor-driven strips and discs under predefined conditions. The IPR auxiliaries were applied at 5 consecutive sessions of 20 s on intact interproximal surfaces, and the surface profile (Ra, Rz, Rmax) was analyzed at baseline and after each session with an optical profilometer.

Results

No overall significant difference in the roughness values was found between systems (P = 0.07 for Ra, P = 0.33 for Rz, and P = 0.48 for Rmax). There was a significant average decrease of Ra, Rz, and Rmax for all systems for every unit increase in time by −0.171 μm (P < 0.001), −3.297 (P ≤ 0.001), and −2.788 μm (P = 0.001), respectively. Ra, Rz, and Rmax values increased significantly, i.e., by 0.194 μm (P = 0.003), 5.890 μm (P = 0.001), and 5.319 μm (P = 0.010) as instrument thickness increased by one unit. No significant reductions in Ra, Rz, and Rmax were observed across grain sizes (−0.008 μm [P > 0.05], −0.244 μm [P > 0.05], and −0.179 μm [P > 0.05], respectively). There was no evidence of interaction between system and time as the P values for Ra, Rz, and Rmax were 0.88, 0.51, and 0.70, respectively.

Conclusions

All IPR materials presented significant gradual decrease of surface roughness after repeated applications. There were no significant roughness changes among auxiliaries of different grain sizes. Thinner auxiliaries showed significantly more roughness reduction, possibly requiring more frequent replacement than thick auxiliaries in clinical practice.
Functional fungal extracts from the Quorn fermentation co-product as novel partial egg white replacers
Authors: Lonchamp J. , Akintoye M. , Clegg P. S. , Euston S. R.
Published: November 2019

The production of mycoprotein biomass by Marlow Foods for use in their meat alternative brand Quorn is a potential source of sustainable alternatives to functional ingredients of animal origin for the food industry. The conversion of this viscoelastic biomass into the Quorn meat-like texture relies on functional synergy with egg white (EW), effectively forming a fibre gel composite. In a previous study, we reported that an extract (retentate 100 or R100) obtained from the Quorn fermentation co-product (centrate) via ultrafiltration displayed good foaming, emulsifying, and rheological properties. This current study investigated if a possible similar synergy between EW and R100 could be exploited to partially replace EW as foaming and/or gelling ingredient. The large hyphal structures characteristic of R100 solutions were observed in EW–R100 mixtures, while EW–R100 gels showed dense networks of entangled hyphal aggregates and filaments. R100 foams prepared by frothing proved less stable than EW ones; however, a 75/25 w/w EW–R100 mixture displayed a similar foam stability to EW. Simlarly, R100 hydrogels proved less viscoelastic than EW ones; however, the viscoelasticity of gels prepared with 50/50 w/w and 75/25 w/w EW–R100 proved similar to those of EW gels, while 75/25 w/w EW–R100 gels displayed similar hardness to EW ones. Both results highlighted a functional synergy between the R100 material and EW proteins. In parallel tensiometry measurements highlighted the presence of surface-active material in EW–R100 mixtures contributing to their high foaming properties. These results highlighted the potential of functional extracts from the Quorn fermentation process for partial EW replacement as foaming and gelling agent, and the complex nature of the functional profile of EW–R100 mixtures, with contributions reported for both hyphal structures and surface-active material.

Graphic abstract
Present day bias and future change signal of temperature over China in a series of multi-GCM driven RCM simulations
Authors: Wu Jia , Gao Xuejie
Published: November 2019

Simulation of surface air temperature over China from a set of regional climate model (RCM) climate change experiments are analyzed with the focus on bias and change signal of the RCM and driving general circulation models (GCMs). The set consists of 4 simulations by the RCM of RegCM4 driven by 4 different GCMs for the period of 1979–2099 under the mid-range RCP4.5 (representative concentration pathway) scenario. Results show that for present day conditions, the RCM provides with more spatial details of the distribution and in general reduces the biases of GCM, in particular in DJF (December–January–February) and over areas with complex topography. Bias patterns show some correlation between the RCM and driving GCM in DJF but not in JJA (June–July–August). In JJA, the biases in RCM simulations show similar pattern and low sensitivity to the driving GCM, which can be attributed to the large effect of internal model physics in the season. For change signals, dominant forcings from the driving GCM are evident in the RCM simulations as shown by the magnitude, large scale spatial distribution, as well as interannual variation of the changes. The added value of RCM projection is characterized by the finer spatial detail in sub-regional (river basins) and local scale. In DJF, profound warming over the Tibetan Plateau is simulated by RCM but not GCMs. In general no clear relationships are found between the model bias and change signal, either for the driving GCMs or nested RCM.