bluuebunny/crossref_metadata_2025 huggingface dataset:
Palladium‐Catalyzed Regioselective C−H Arylation of Quinoline‐N‐Oxides at C‐8 Position using Diaryliodonium Salts
Authors: Sharma Shivani , Kumar Sehdev , Sharma Anuj
Published: January 2020

A simple and efficient Pd(II)‐catalyzed site‐selective direct arylation strategy was demonstrated for the synthesis of 8‐arylquinoline‐N‐oxide derivatives using quinoline‐N‐oxides and (aryl)(mesityl)iodonium triflates. A series of control experiments were carried out to elucidate the reaction mechanism. The synthetic potential was extended with the C‐2 post‐modification of the final derivative.
Engineering Iron–Nickel Nanoparticles for Magnetically Induced CO2Methanation in Continuous Flow
Authors: De Masi Déborah , Asensio Juan M. , Fazzini Pier‐Francesco , Lacroix Lise‐Marie , Chaudret Bruno
Published: January 2020

Induction heating of magnetic nanoparticles (NPs) is a method to activate heterogeneous catalytic reactions. It requires nano‐objects displaying high heating power and excellent catalytic activity. Here, using a surface engineering approach, bimetallic NPs are used for magnetically induced CO2methanation, acting both as heating agent and catalyst. The organometallic synthesis of Fe30Ni70NPs displaying high heating powers at low magnetic field amplitudes is described. The NPs are active but only slightly selective for CH4after deposition on SiRAlOx owing to an iron‐rich shell (25 mL min−1, 25 mT, 300 kHz, conversion 71 %, methane selectivity 65 %). Proper surface engineering consisting of depositing a thin Ni layer leads to Fe30Ni70@Ni NPs displaying a very high activity for CO2hydrogenation and a full selectivity. A quantitative yield in methane is obtained at low magnetic field and mild conditions (25 mL min−1, 19 mT, 300 kHz, conversion 100 %, methane selectivity 100 %).
Gold(I)‐katalysierte Cycloisomerisierung von 3‐Alkoxy‐1,6‐diinen: ein einfacher Zugang zu Bicyclo[2.2.1]hept‐5‐en‐2‐onen
Authors: Hu Chao , Wang Tao , Rudolph Matthias , Oeser Thomas , Asiri Abdullah M. , Hashmi A. Stephen K.
Published: January 2020

Eine neue Gold‐katalysierte Cycloisomerisierung von 1,6‐diinen wurde entwickelt, die einen atomökonomischen Zugang zu einem Satz verschiedenster Bicyclo[2.2.1]hept‐5‐en‐2‐onen in moderaten bis guten Ausbeuten darstellt. Für unsymmetrische Edukte mit zwei verschiedenen internen Alkinyl‐Substituenten konnte in einem gewissen Ausmaß die Regioselektivität sowohl durch elektronische als auch durch sterische Faktoren kontrolliert werden. Dieses neue Reaktivitätsmuster kann als Grundlage für neue und unkonventionelle Strategien für die Synthese überbrückter Ringsysteme dienen.
Radially Inwardly Aligned Hierarchical Porous Carbon for Ultra‐Long‐Life Lithium–Sulfur Batteries
Authors: Yu Zhisheng , Liu Menglan , Guo Daying , Wang Jiahui , Chen Xing , Li Jun , Jin Huile , Yang Zhi , Chen Xi'an , Wang Shun
Published: January 2020

Rational design of hollow micro‐ and/or nano‐structured cathodes as sulfur hosts has potential for high‐performance lithium‐sulfur batteries. However, their further commercial application is hindered because infusing sulfur into hollow hosts is hard to control and the interactions between high loading sulfur and electrolyte are poor. Herein, we designed hierarchical porous hollow carbon nanospheres with radially inwardly aligned supporting ribs to mitigate these problems. Such a structure could aid the sulfur infusion and maximize sulfur utilization owing to the well‐ordered pore channels. This highly organized internal carbon skeleton can also enhance the electronic conductivity. The hollow carbon nanospheres with further nitrogen‐doping as the sulfur host material exhibit good capacity and excellent cycling performance (0.044 % capacity degradation per each cycle for 1000 cycles).
Bestimmung komplexer kleiner Molekülstrukturen mittels molekularer Ausrichtungssimulation
Authors: Ibáñez de Opakua Alain , Klama Frederik , Ndukwe Ikenna E. , Martin Gary E. , Williamson R. Thomas , Zweckstetter Markus
Published: January 2020

Die korrekte strukturelle Zuordnung von kleinen Molekülen und Naturstoffen ist für die Wirkstoffentdeckung und die organische Chemie von entscheidender Bedeutung. Die Anisotropie‐basierte NMR‐Spektroskopie ist ein leistungsfähiges Instrument zur strukturellen Zuordnung organischer Moleküle, beruht jedoch auf der Verwendung eines Mediums, das die isotrope Bewegung von Molekülen in organischen Lösungsmitteln stört. Hier stellen wir eine quantitative Korrelation zwischen der Atomstruktur des Ausrichtungsmediums, der Molekülstruktur des kleinen Moleküls und den molekülspezifischen, anisotropen NMR‐Parametern her. Die quantitative Korrelation verwendet ein dreidimensionales molekulares Ausrichtungsmodell, das dipolare Restkopplungen kleiner Moleküle vorhersagt, die durch Poly(γ‐benzyl‐l‐glutamat) ausgerichtet sind. Die Methode erleichtert die zuverlässige Bestimmung des richtigen Stereoisomers und ermöglicht die eindeutige und schnelle Bestimmung komplexer Molekülstrukturen aus sehr spärlichen NMR‐Daten.
Phosphorus Vacancies that Boost Electrocatalytic Hydrogen Evolution by Two Orders of Magnitude
Authors: Duan Jingjing , Chen Sheng , Ortíz‐Ledón César A. , Jaroniec Mietek , Qiao Shi‐Zhang
Published: January 2020

Vacancy engineering is an effective strategy to manipulate the electronic structure of electrocatalysts to improve their performance, but few reports focus on phosphorus vacancies (Pv). Herein, the creation of Pv in metal phosphides and investigation of their role in alkaline electrocatalytic hydrogen evolution reaction (HER) is presented. The Pv‐modified catalyst requires a minimum onset potential of 0 mV vs. RHE, a small overpotential of 27.7 mV to achieve 10 mA cm−2 geometric current density and a Tafel slope of 30.88 mV dec−1, even outperforms the Pt/C benchmark (32.7 mV@10 mA cm−2 and 30.90 mV dec−1). This catalyst also displays superior stability up to 504 hours without any decay. Experimental analysis and density functional theory calculations suggest Pv can weaken the hybridization of Ni 3d and P 2p orbitals, enrich the electron density of Ni and P atoms nearby Pv, and facilitate H* desorption process, contributing to outstanding HER activity and facile kinetics.
Redox Mediated Synthesis of Ag‐CuO Hybrid Nanoparticles – DNA/BSA Binding Studies and in vitro Evaluation of Anti‐cancer Activity on MCF‐7 Cancer Cell Line
Authors: C. Joel , D.S. Ivan Jebakumar , Bennie R. Biju , Stuart J. Gershom , Raj A. Nirmal Paul , David S. Theodore
Published: January 2020

We herein report a nanoparticle‐directed therapeutic approach to breast cancer using Ag‐CuO hybrid nanoparticles. The nanoparticles were synthesized through redox‐mediated process involving reduction of silver ion on the surface of Cu2O nanostructures. Structural, microstructural and optical characterization were carried out and the hybrid nanoparticles were found to be phase pure with crystallite size between 100–200 nm and the absorption due to surface plasmon resonance from silver was observed around 460 nm. The binding affinities of the hybrid nanoparticles with the plasma protein BSA and calf thymus DNA were studied and the respective binding constants were found to be 5.1 × 104 and 1.12 × 105 M−1 showing appreciable binding affinity of the substrate. The cytotoxicity of the as‐synthesized hybrid nanoparticles induced in breast cancer cells was evaluated in vitro and the obtained results demonstrates the potential anti‐cancer activity of the Ag‐CuO hybrid nanoparticles against the MCF‐7 breast cancer cell line.
Synthesis of an amphoteric polymer as a high‐temperature‐resistant shale stabilizer in water‐based drilling fluids
Authors: Jiang Guancheng , Wang Kai , He Yinbo , Yang Lili , Li Xinliang , Deng Yu
Published: January 2020

To meet the increasing requirement of stabilizing shale under high‐temperature situation with the use of water‐based drilling fluids (WBDFs), the high‐performance shale stabilizer is an urgent need. In this study, an amphoteric copolymer of AM/DMDAAC/NVP (APC) was synthesized by acrylamide (AM), dimethyl diallyl ammonium chloride (DMDAAC), and N‐vinylpyrrolidone (NVP) and used as a high temperature‐resistant shale stabilizer. The Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy confirmed the successful synthesis of APC. The inhibitive performance of APC was systematically evaluated and compared with three other commonly used shale stabilizers, including the anionic potassium polyacrylamide (KPAM), cationic poly dimethyl diallyl ammonium chloride (PD), and amphoteric polymer FA367. The results demonstrated that APC displayed excellent performance on the linear swelling test, hot‐rolling recovery experiment, and shale immersion test. Furthermore, APC combined the advantages of high shale recovery percentages of PD and maintaining shale pellet integrity of KPAM, avoiding the drawbacks of enormous filtration volume of PD and low shale recovery percentages of KPAM. These great properties indicated that APC would be suitable as a shale stabilizer in WBDF to drill high‐temperature shale formation.
Development of 18 microsatellite markers for Salvia pratensis
Authors: Krak Karol , Vít Petr , Douda Jan , Mandák Bohumil
Published: January 2020

Premise

Microsatellite markers were developed for the perennial herb Salvia pratensis (Lamiaceae), a species representative of European dry grasslands. The development of microsatellite markers is needed for genetic and phylogeographical studies of species from the genus Salvia.

Methods and Results

We used low‐coverage Illumina sequencing to identify microsatellite loci. Based on these data, we have developed 18 polymorphic microsatellite markers with the number of alleles per locus ranging from two to 15. The levels of observed and expected heterozygosity ranged from 0.05 to 0.95 and from 0.05 to 0.89, respectively. The majority of the markers successfully cross‐amplified in other Salvia species.

Conclusions

The markers were shown to be suitable for population genetic and phylogeographic studies in S. pratensis as well as in related species (S. aethiopis, S. austriaca, S. glutinosa, S. nemorosa, S. nutans, and S. verticillata) and will be used in the broader context to trace the origins of European dry grasslands.
Pushing the limits of General Relativity beyond the Big Bang singularity
Authors: Zen Vasconcellos César A. , Hadjimichef Dimiter , Razeira Moisés , Volkmer Guilherme , Bodmann Benno
Published: January 2020

The predictions of General Relativity suggest a universe in which, as we follow time backward, the hotter and the more dense it was, and the more rapidly it was expanding and that, around 13.7 billion years ago, at the extreme gravitational regime of its evolutionary process, the density, temperature, and expansion rate of the universe would start off as infinite. The General Relativity prediction of a singularity in the early universe would impose a limitation to our understanding of the cosmos and gravity, implying loss of logic and of formal consistency and predictability, making it impossible to impose initial conditions. These extreme conditions of the initial state of the universe are very far from our experimental possibilities, and presently, theoretical models allow only speculations about the avoidance of physical singularities or about the physical conditions that allow circumvent this drastic consequence of General Relativity. Speculations aside, in this study, we follow an analytical line in which we apply the tools of singular semi‐Riemannian geometry to push the limits of General Relativity beyond the Big Bang singularity.
Modified staging system for gastric neuroendocrine carcinoma based on American Joint Committee on Cancer and European Neuroendocrine Tumor Society systems
Authors: Lu J , Zhao Y J , Zhou Y , He Q , Tian Y , Hao H , Qiu X , Jiang L , Zhao G , Huang C-M
Published: January 2020

Background

The prognostic values of the AJCC staging system for gastric cancer (GC-AJCC), the AJCC staging system for gastric neuroendocrine tumours (NET-AJCC) and the European Neuroendocrine Tumor Society (ENETS) system for gastric neuroendocrine carcinoma and mixed adenoneuroendocrine carcinoma (MA)NEC remain controversial.

Methods

Data on patients with (MA)NEC from 21 centres in China were analysed. Different staging systems were evaluated by performing Kaplan–Meier survival analysis and calculating the concordance index (C-index) and Akaike information criterion (AIC). Based on three existing systems, a modified staging system (mTNM) was developed.

Results

A total of 871 patients were included. In the GC-AJCC system, an overlap was noticed for pT2 and pT3 categories. Patients with stage IIIC disease had a similar prognosis to those with stage IV disease. The pT categories of the NET-AJCC system had a lower C-index and higher AIC than those of the other systems. In the ENETS system, there was a low proportion (0·2 per cent) of patients with stage IIIA and a high proportion (67·6 per cent) of stage IIIB disease. The mTNM system adopted the NET-AJCC pT and GC-AJCC pN and pM definitions, and was developed based on the ENETS stage definitions. The proportion of patients in each stage was better distributed and the mTNM system showed improved prognostic performance in predicting overall and disease-free survival.

Conclusion

The mTNM system offers more accurate prognostic value for gastric (MA)NEC than the AJCC or ENETS staging systems.
Exploring the social cognition network in young adults with autism spectrum disorder using graph analysis
Authors: Vagnetti Roberto , Pino Maria Chiara , Masedu Francesco , Peretti Sara , Le Donne Ilenia , Rossi Rodolfo , Valenti Marco , Mazza Monica
Published: January 2020

Background

Autism spectrum disorder (ASD) is characterized by an impairment in social cognition (SC). SC is a cognitive construct that refers to the capacity to process information about social situations. It is a complex network that includes distinct components. Exploring how SC components work together leads to a better understanding of how their interactions promote adequate social functioning. Our main goal was to use a novel statistical method, graph theory, to analyze SC relationships in ASD and Typically Developing (TD) individuals.

Methods

We applied graph theory to SC measures to verify how the SC components interact and to establish which of them are important within the interacting SC network for TD and ASD groups.

Results

The results showed that, in the TD group, the SC nodes are connected; their network showed increased betweenness among nodes, especially for the Theory of Mind. By contrast, in the SC network in the ASD group the nodes are highly disconnected, and the efficient connection among the components is absent.

Conclusion

ASD adults do not show SC competencies and functional communication among these skills. Under this regard, specific components are crucial, suggesting they could represent critical domains for ASD SC.
Carbon risk management and corporate competitive advantages: “Differential promotion” or “cost hindrance”?
Authors: Zhou Zhifang , Zhang Lingyan , Lin Li , Zeng Huixiang , Chen Xiaohong
Published: January 2020

Given the strengthening of carbon regulations and the launch of emission trading scheme in China, companies are facing tremendous pressure to reduce carbon emissions, suggesting the necessity of understanding whether carbon risk management may affect corporate financial benefits. Therefore, this paper empirically demonstrates the influence of carbon risk management on corporate competitive advantages. We find that the relationship between carbon risk management and corporate competitive advantages is a “kuznets curve” that exists only among firms with weak product competition. And this relationship tends to be weakened in firms with a distant administrative hierarchy. We conclude that the influence of low carbon management on corporate competitive advantages is complicated and subject to the firm's political relevance.
miR‐215‐5p decreases migration and invasion of trophoblast cells through regulating CDC6 in preeclampsia
Authors: Yang Xiuhua , Meng Tao
Published: January 2020

Preeclampsia (PE) is a serious disease that occurs after 20 weeks during pregnancy. There are some aberrant microRNAs (miRNAs) that are associated with the etiology of PE. As discovered by scholars, there was an increased level of miR‐215‐5p in plasma of PE patients compared with the control group; nonetheless, there is still no knowledge of the mechanism of miR‐215‐5p in PE. We carried out the comparison of the expression levels of miR‐215‐5p, and the supposed target gene cell division cycle 6 (CDC6) in 30 placentas from PE patients as well as 30 placentas from normal pregnant women. The verification of the impacts of miR‐215‐5p and CDC6 was carried out by functional assays in HTR‐8/SVneo cells transfected with the miR‐215‐5p mimic or siR‐CDC6. As indicated by findings, miR‐215‐5p showed an apparent increase; conversely, CDC6 was inhibited in the experiment group. The upregulation of miR‐215‐5p inhibited both the migration and invasive potential of trophoblasts, besides decreasing the G1‐S transition and downregulating CDC6 in HTR‐8/SVneo cells; nonetheless, it did not significantly impact the cell proliferation. Furthermore, siR‐CDC6 replicated the functions of the miR‐215‐5p mimic. Also, the miR‐215‐5p mimic and siR‐CDC6 both decreased the epithelial‐mesenchymal transition (EMT) with additional E‐cadherin level and decreased the expressions of N‐cadherin as well as vimentin in trophoblast cells. To conclude, miR‐215‐5p decreased not only the migration but also the invasion of trophoblasts through regulating CDC6, which indicated that miR‐215‐5p might be associated with the etiology of PE.

Significance of the study

More and more attention has been paid on the roles of miRNAs in the pathogenesis of PE. However, there is no study of miR‐215‐5p in the etiology of PE. We first investigated the mechanism of miR‐215‐5p in placental tissues and HTR‐8/SVneo cells. It was suggested that miR‐215‐5p decreased the abilities of migration and invasion of trophoblasts through regulating CDC6 in PE. miR‐215‐5p might be used as an target for the early diagnosis and treatment of PE in the future.
The Machado–Joseph disease‐associated form of ataxin‐3 impacts dynamics of clathrin‐coated pits
Authors: Rosselli‐Murai Luciana K. , Joseph Jophin G. , Lopes‐Cendes Iscia , Liu Allen P. , Murai Marcelo J.
Published: January 2020

Expansion above a certain threshold in the polyglutamine (polyQ) tract of ataxin‐3 is the main cause of neurodegeneration in Machado–Joseph disease. Ataxin‐3 contains an N‐terminal catalytic domain, called Josephin domain, and a highly aggregation‐prone C‐terminal domain containing the polyQ tract. Recent work has shown that protein aggregation inhibits clathrin‐mediated endocytosis (CME). However, the effects of polyQ expansion in ataxin‐3 on CME have not been investigated. We hypothesize that the expansion of the polyQ tract in ataxin‐3 could impact CME. Here, we report that both the wild‐type and the expanded ataxin‐3 reduce transferrin internalization and expanded ataxin‐3 impacts dynamics of clathrin‐coated pits (CCPs) by reducing CCP nucleation and increasing short‐lived abortive CCPs. Since endocytosis plays a central role in regulating receptor uptake and cargo release, our work highlights a potential mechanism linking protein aggregation to cellular dysregulation.
Simplifying transfemoral ACURATE neo implantation using the TrueFlow nonocclusive balloon catheter
Authors: Toggweiler Stefan , Loretz Lucca , Brinkert Miriam , Bossard Matthias , Wolfrum Mathias , Moccetti Federico , Berte Benjamin , Cuculi Florim , Kobza Richard
Published: January 2020

Objectives

This study aimed to investigate the safety and efficacy of ACURATE neo transcatheter aortic valve replacement (TAVR) facilitated by predilatation with the nonocclusive TrueFlow balloon catheter.

Background

Now that TAVR is moving forward, physicians have attempted to simplify and streamline the procedure and the so‐called minimalist approach has become more popular.

Methods

We enrolled 142 patients (mean age: 82 ± 5 years, 61% female) in a prospective registry. Patients at low risk for intraprocedural third‐degree atrioventricular block (AVB) underwent TAVR with the TrueFlow balloon without rapid pacing and without insertion of a provisional pacemaker (n = 121). The remaining 21 patients were predilated with rapid pacing using a provisional pacemaker and a standard balloon.

Results

Predilatation with the TrueFlow balloon was successful in all 121 patients. Postdilatation was less frequently required after predilatation with the TrueFlow (25% vs. 57%, p = .003). Moreover, median procedural duration with the TrueFlow was significantly shorter (42 [interquartile range, IQR: 34–53] vs. 55 [IQR: 46–61] min, p = .004). In‐hospital outcomes were similar. At 30 days, there was no mortality, two (1%) patients had suffered a stroke and only four (3%) had required implantation of a new pacemaker.

Conclusion

Among patients with a low risk for intraprocedural third‐degree AVB, the TrueFlow nonocclusive balloon catheter facilitates implantation of the ACURATE neo without the necessity of rapid pacing and a provisional pacemaker.
Unusual Photoactive Water Oxidation Activity of Pt/PtOx Cocatalyst Decorated Crystalline α‐Fe2O3 Nanostructures: Exposed Facets Dependent Reactivity
Authors: Patra Astam K. , Amoli Vipin , Sinha Anil K. , Kim Dukjoon
Published: January 2020

A key challenge remains the preparation of an active and robust water oxidation photocatalyst with abundant earth materials. As a useful to improve photocatalytic efficiency, the development of α‐Fe2O3 nanocrystals with different exposed facets and interfaces has attracted enormous attention. But literature survey shows that α‐Fe2O3 nanomaterials were mainly used in photoelectrochemical cell for water splitting as anode materials. In this work, highly efficient Pt/PtOx cocatalyst decorated α‐Fe2O3 shaped‐photocatalysts were derived as photocatalyst for white light‐induced O2 generation from water without any electric potential. The maximum apparent quantum efficiency of photooxidation reaction was reached 55.33 % by Pt/PtOx decorated bitruncated‐dodecahedron shaped α‐Fe2O3 and around 30.5, 2.3, 1.28 times better than the Pt/PtOx decorated nanocuboid, nanorod and bitruncated‐octahedron shape respectively. The Pt/PtOx decorated bitruncated‐dodecahedron shaped α‐Fe2O3 display an unusual photooxidation activity with a high TOF (1.96×10−2 s−1) due to presence of destabilized and unsaturated Fe centre containing high energy {104} and {100} facets. The present findings clearly demonstrate that the selective O2 evolution from water can possible without any sacrificial agent.
Defect‐Engineered Ruthenium MOFs as Versatile Heterogeneous Hydrogenation Catalysts
Authors: Epp Konstantin , Luz Ignacio , Heinz Werner R. , Rapeyko Anastasia , Llabrés i Xamena Francesc X. , Fischer Roland A.
Published: January 2020

Ruthenium MOF [Ru3(BTC)2Yy] ⋅ Gg (BTC=benzene‐1,3,5‐tricarboxylate; Y=counter ions=Cl−, OH−, OAc−; G=guest molecules=HOAc, H2O) is modified via a mixed‐linker approach, using mixtures of BTC and pyridine‐3,5‐dicarboxylate (PYDC) linkers, triggering structural defects at the distinct Ru2 paddlewheel (PW) nodes. This defect‐engineering leads to enhanced catalytic properties due to the formation of partially reduced Ru2‐nodes. Application of a hydrogen pre‐treatment protocol to the Ru−MOFs, leads to a further boost in catalytic activity. We study the benefits of (1) defect engineering and (2) hydrogen pre‐treatment on the catalytic activity of Ru−MOFs in the Meerwein‐Ponndorf‐Verley reaction and the isomerization of allylic alcohols to saturated ketones. Simple solvent washing could not avoid catalyst deactivation during recycling for the latter reaction, while hydrogen treatment prior to each catalytic run proved to facilitate materials recyclability with constant activity over five runs.
A Newly Synthesized Tris(crown ether) Ionophore for Assisted Ion Transfer at NanoITIES Electrodes
Authors: Chen Ran , Yang Anna , Chang Albert , Oweimrin Philip F. , Romero Julian , Vichitcharoenpaisarn Pitchaya , Tapia Stephanie , Ha Kevin , Villaflor Christopher , Shen Mei
Published: January 2020

Assisted ion transfer at a pipet‐supported interface between two immiscible electrolyte solutions (ITIES) have become a prominent method for the detection of various ionic species and for studying ionic complexation. A typical ionophore contains one binding center to ions such as dibenzo‐18‐crown‐6 (DB18C6). It is unknown how the detection of ions changes when assisted by an ionophore with multiple crown ether moieties. Here, we synthesized a new tris(crown ether) ionophore, TriBCE, which is composed of three 18‐crown‐6 moieties connected to a common o‐phenylene ethynylene cyclic trimer center, and employed TriBCE for the assisted ion transfer of various environmentally relevant heavy‐metal ions (i. e. Mg2+, Cu2+, Cd2+ and Li+) and a neurotransmitter (dopamine) at nanoITIES pipet electrodes. The half‐wave transfer potentials for those ions were less positive by 123±28 mV when assisted by tris (crown ether), TriBCE, compared to mono(crown ether), DB18C6. The binding constants, Gibbs free energy, and the stoichiometric coefficients of ionic complexation with TriBCE were measured and compared to that of DB18C6 to reveal that ionophore with multiple binding moieties enables easier transfer of these ions.
CCR5 is a novel target for the treatment of experimental alopecia areata
Authors: Ito Taisuke , Suzuki Takahiro , Funakoshi Atsuko , Fujiyama Toshiharu , Tokura Yoshiki
Published: January 2020

Background

Alopecia areata (AA) is an organ‐specific and cell‐mediated autoimmune disease. Hair follicle autoantigens are disclosed to these autoreactive NKG2D+CD8+ T cells. A Th1 chemokine, CXCL10, is highly expressed on hair follicle keratinocytes and leads to the infiltration of CXCR3+ and CCR5+ Th1 or Tc1 cells around anagen hair follicles in AA lesions.

Aim

To evaluate CCR5 as a new candidate target for the treatment of experimental AA.

Methods

We initiated 7‐month‐old female C3H/HeJ mice with intracutaneous injections of lymph node (LN) cells, which were activated by IL‐2, IL‐7, IL‐15, and CD3/CD25 Dynabeads, from C3H/HeJ mice with spontaneous AA. Then, 330 μg/d of maraviroc, a negative allosteric modulator of the CCR5 receptor that is already used for treating patients with human immunodeficiency virus, was orally administrated for 28 days.

Results

We successfully treated the experimental AA lesions of C3H/HeJ mice with maraviroc. In addition, CCR5 blockade prevented the development of AA in activated T cell‐transferred C3H/HeJ mice. Interestingly, maraviroc‐treated C3H/HeJ mice with experimental AA showed improvement of hair loss lesions after 2 weeks. Immunohistological assessments and FACS analysis revealed a decreased number of CD4+CCR5+ and CD8+CCR5+ T cells in the lesions after maraviroc treatment. A real‐time horizontal chemotaxis assay showed that maraviroc significantly inhibited the chemotactic activity of CD8+ LN cells toward RANTES. Furthermore, CCR5 blockade prevented experimental AA development when compared to phosphate‐buffered saline.

Conclusion

CCR5 appears to be a promising new candidate target for the treatment of AA. CCR5 blockade may prevent the development of AA as well as improve AA lesions.
Palm Oil – “all‐round talent“ and green horror: an interdisciplinary concept for a multidimensional view on palm oil
Authors: Müller Sarah Christin , Heimann Rebekka
Published: January 2020

Im Rahmen dieses Beitrags wird ein fächerübergreifendes Konzept zum Thema Palmöl beschrieben. Dieses wurde ursprünglich als Schülerlabortag konzipiert, kann aber ebenfalls im Chemieunterricht und in fächerübergreifenden Projekttagen eingesetzt werden. Das Konzept zielt auf die Förderung von Naturverbundenheit und besonders auch von Umweltwissen ab, welche beide nachweislich die Umwelthandlungskompetenz beeinflussen. Die Schülerinnen und Schüler erfahren dabei die Vielschichtigkeit der Thematik und reflektieren letztendlich ihr eigenes Konsumverhalten vor dem Hintergrund des Nachhaltigkeitsgedankens.
Prediagnosis social support, social integration, living status, and colorectal cancer mortality in postmenopausal women from the women's health initiative
Authors: Kroenke Candyce H. , Paskett Electra D. , Cené Crystal W. , Caan Bette J. , Luo Juhua , Shadyab Aladdin H. , Robinson Jamaica R. M. , Nassir Rami , Lane Dorothy S. , Anderson Garnet L.
Published: January 2020

Background

We evaluated associations between perceived social support, social integration, living alone, and colorectal cancer (CRC) outcomes in postmenopausal women.

Methods

The study included 1431 women from the Women's Health Initiative who were diagnosed from 1993 through 2017 with stage I through IV CRC and who responded to the Medical Outcomes Study Social Support survey before their CRC diagnosis. We used proportional hazards regression to evaluate associations of social support (tertiles) and types of support, assessed up to 6 years before diagnosis, with overall and CRC‐specific mortality. We also assessed associations of social integration and living alone with outcomes also in a subset of 1141 women who had information available on social ties (marital/partner status, community and religious participation) and living situation.

Results

In multivariable analyses, women with low (hazard ratio [HR], 1.52; 95% CI, 1.23‐1.88) and moderate (HR, 1.21; 95% CI, 0.98‐1.50) perceived social support had significantly higher overall mortality than those with high support (P[continuous] < .001). Similarly, women with low (HR, 1.42; 95% CI, 1.07‐1.88) and moderate (HR, 1.28; 95% CI, 0.96‐1.70) perceived social support had higher CRC mortality than those with high social support (P[continuous] = .007). Emotional, informational, and tangible support and positive interaction were all significantly associated with outcomes, whereas affection was not. In main‐effects analyses, the level of social integration was related to overall mortality (Pfor trend = .02), but not CRC mortality (Pfor trend = .25), and living alone was not associated with mortality outcomes. However, both the level of social integration and living alone were related to outcomes in patients with rectal cancer.

Conclusions

Women with low perceived social support before diagnosis have higher overall and CRC‐specific mortality.
VANET: A novel service for predicting and disseminating vehicle traffic information
Authors: Abdelatif Sahraoui , Derdour Makhlouf , Ghoualmi‐Zine Nacira , Marzak Bouchra
Published: January 2020

The arrival of cloud computing technology promises innovative solutions to the problems inherent in existing vehicular ad hoc network (VANET) networks. Because of the highly dynamic nature of these networks in crowded conditions, some network performance improvements are needed to anticipate and disseminate reliable traffic information. Although several approaches have been proposed for the dissemination of data in the vehicular clouds, these approaches rely on the dissemination of data from conventional clouds to vehicles, or vice versa. However, anticipating and delivering data, in a proactive way, based on query message or an event driven has not been defined so far by these approaches. Therefore, in this paper, a VANET‐Cloud layer is proposed for traffic management and network performance improvements during congested conditions. For the traffic management, the proposed layer integrates the benefits of the connected sensor network (CSN) to collect traffic data and the cloud infrastructure to provide on‐demand and automatic cloud services. In this work, traffic services use a data exchange mechanism to propagate the predicted data using a fuzzy aggregation technique. In the evaluation phase, simulation results demonstrate the effectiveness of the proposed VANET‐Cloud layer to dramatically improve traffic safety and network performance as compared with recent works.
Middleman covert channel establishment based on MORE routing protocol using network coding in ad hoc networks
Authors: Akhtari Sara , Moghim Neda , Mahdavi Mojtaba
Published: January 2020

Covert channels have been recently the subject of the study in both creation and countermeasure aspects. There are many different ways to embed the covert data in network standards and protocols, especially in wireless networks. MORE (MAC‐independent opportunistic routing) is an opportunistic routing protocol which uses networks coding to enhance routing performance by reducing the repetitions. This protocol can be a suitable medium for covert channel establishment. A middleman covert channel establishment method is proposed in this paper over MORE routing protocol and with the use of network coding. Hidden data are transferred through packet's payload bytes. Covert sender manipulates coding mechanism by calculating packets' coefficients instead of random selection. The proposed covert channel provides the average throughput of 218 and 231 bps, using two different data length approaches which is relatively a good comparing to the previous network layer covert channels. The proposed covert channel is also a covert storage channel and cannot be removed or restricted. Effect of different network characteristics on the proposed method's capacity and security is investigated by a simulation study, and the results are discussed.
Bee communities and pollination services in adjacent crop fields following flower removal in an invasive forest shrub
Authors: Cunningham‐Minnick Michael J. , Peters Valerie E. , Crist Thomas O.
Published: January 2020

The habitat boundaries between crops and seminatural areas influence bee movements and pollination services to crops. Edges also provide favorable conditions for invasive plants, which may usurp pollinators and reduce visitation to native or crop plants. Alternatively, floral displays of alien plants may facilitate, or increase, the pollination success of adjacent plants by attracting more pollinators to the area. Therefore, pollination services of bees from seminatural habitats to crop areas should vary with the presence of invasive floral resources and distance from habitat edges. To test the hypothesis that floral resources of invasive forest shrubs affect the bee community and pollination services in adjacent crop fields, we conducted a 2‐yr field experiment along forest–crop edges at five isolated forest remnants. We removed flower buds from a dominant invasive shrub, Lonicera maackii (Amur honeysuckle), along forest–crop edges and paired removals with controls of intact flowers. The bee community, their pollination services, and flower visitation rates were quantified along a 200‐m gradient into an adjacent crop field using pan traps and sentinel cucumber plants. Impacts to the bee community were dependent of bee functional traits. Larger bees visited fewer sentinel cucumber flowers in flower removal plots, which corresponded with decreased cucumber pollination compared to plots with honeysuckle flowers at distances >100 m from forest edges. Small‐bodied and weaker flying bees visited sentinel plants more frequently closer to the forest edge and increased pollination services to cucumber at distances <100 m from L. maackii shrubs in flower removal plots. After 2 yr, bee abundance and species richness increased within flower removal plots across all distances. High functional diversity of the bee community increased pollination services to sentinel plants and increased cucumber production within 200 m from forest remnants. Our findings suggest that dense floral resources of invasive shrubs suppressed forest‐edge bee communities and their pollination services, but also attracted large‐bodied generalist bees, which were effective pollinators. This study helps explain how life histories and functional attributes of bees can predict either facilitation or suppression of pollination services to crop or native plants in response to invasive floral resources.
Regional mapping of species‐level continuous foliar cover: beyond categorical vegetation mapping
Authors: Nawrocki Timm W. , Carlson Matthew L. , Osnas Jeanne L. D. , Trammell E. Jamie , Witmer Frank D. W.
Published: January 2020

The ability to quantify spatial patterns and detect change in terrestrial vegetation across large landscapes depends on linking ground‐based measurements of vegetation to remotely sensed data. Unlike non‐overlapping categorical vegetation types (i.e., typical vegetation and land cover maps), species‐level gradients of foliar cover are consistent with the ecological theories of individualistic response of species and niche space. We collected foliar cover data for vascular plant, bryophyte, and lichen species and 17 environmental variables in the Arctic Coastal Plain and Brooks Foothills of Alaska from 2012 to 2017. We integrated these data into a standardized database with 13 additional vegetation survey and monitoring data sets in northern Alaska collected from 1998 to 2017. To map the patterns of foliar cover for six dominant and widespread vascular plant species in arctic Alaska, we statistically associated ground‐based measurements of species distribution and abundance to environmental and multi‐season spectral covariates using a Bayesian statistical learning approach. For five of the six modeled species, our models predicted 36% to 65% of the observed species‐level variation in foliar cover. Overall, our continuous foliar cover maps predicted more of the observed spatial heterogeneity in species distribution and abundance than an existing categorical vegetation map. Mapping continuous foliar cover at the species level also revealed ecological patterns obscured by aggregation in existing plant functional type approaches. Species‐level analysis of vegetation patterns enables quantifying and monitoring landscape‐level changes in species, vegetation communities, and wildlife habitat independently of subjective categorical vegetation types and facilitates integrating spatial patterns across multiple ecological scales. The novel species‐level foliar cover mapping approach described here provides spatial information about the functional role of plant species in vegetation communities and wildlife habitat that are not available in categorical vegetation maps or quantitative maps of broadly defined vegetation aggregates.
Ice‐age persistence and genetic isolation of the disjunct distribution of larch in Alaska
Authors: Napier Joseph D. , Fernandez Matias C. , de Lafontaine Guillaume , Hu Feng Sheng
Published: January 2020

Larix laricina (eastern larch, tamarack) is a transcontinental North American conifer with a prominent disjunction in the Yukon isolating the Alaskan distribution from the rest of its range. We investigate whether in situ persistence during the last glacial maximum (LGM) or long‐distance postglacial migration from south of the ice sheets resulted in the modern‐day Alaskan distribution. We analyzed variation in three chloroplast DNA regions of 840 trees from a total of 69 populations (24 new sampling sites situated on both sides of the Yukon range disjunction pooled with 45 populations from a published source) and conducted ensemble species distribution modeling (SDM) throughout Canada and United States to hindcast the potential range of L. laricina during the LGM. We uncovered the genetic signature of a long‐term isolation of larch populations in Alaska, identifying three endemic chlorotypes and low levels of genetic diversity. Range‐wide analysis across North America revealed the presence of a distinct Alaskan lineage. Postglacial gene flow across the Yukon divide was unidirectional, from Alaska toward previously glaciated Canadian regions, and with no evidence of immigration into Alaska. Hindcast SDM indicates one of the broadest areas of past climate suitability for L. laricina existed in central Alaska, suggesting possible in situ persistence of larch in Alaska during the LGM. Our results provide the first unambiguous evidence for the long‐term isolation of L. laricina in Alaska that extends beyond the last glacial period and into the present interglacial period. The lack of gene flow into Alaska along with the overall probability of larch occurrence in Alaska being currently lower than during the LGM suggests that modern‐day Alaskan larch populations are isolated climate relicts of broader glacial distributions, and so are particularly vulnerable to current warming trends.
Using Existing Data to Inform Development of New Item Types
Authors: Guo Hongwen , Ling Guangming , Frankel Lois
Published: January 2020

With advances in technology, researchers and test developers are developing new item types to measure complex skills like problem solving and critical thinking. Analyzing such items is often challenging because of their complicated response patterns, and thus it is important to develop psychometric methods for practitioners and researchers to analyze these new item types. In this study, we describe a generic approach that involves data‐driven analyses and expert feedback from different research areas so that the analysis results can provide valuable information to test developers and researchers on how complex item types contribute to score reliability and validity and on how to make the test more efficient and reliable in measuring complex skills. A real data example was used to illustrate how to identify nonfunctioning options that might be removed from the test and whether partial credit for certain response selections can be considered.
Design and Development of Open Cathode PEM Fuel Cell – Flow Analysis Optimization by CFD
Authors: Gopi K. H. , Nambi A. , Rajalakshmi N.
Published: January 2020

Air‐cooled polymer electrolyte membrane fuel cells (PEMFCs) have emerged as a potential power generation source, due to its simple construction and operation. Flow‐field designing for the efficient distribution of reactants is of paramount importance in air‐cooled PEM fuel cells. The requirement of flow fields with uniform distribution amounting to minimal pressure drop across the flow area is necessary for high gas utilization and easy removal of water. Thus, the present work deals with the design of land and pillar flow field type for cathode, and further optimization of its flow pattern. A 3‐D computational fluid dynamics analysis tool for modeling fluid flow was used for simulating the reactant distribution profile and finalizing the flow field design. The effect of flow field design, inlet velocity and inlet ports dimension were studied in order to obtain flow pattern with uniform distribution. The optimized configuration showed higher percentage of flow area (76%) with outlet velocities ranging from 3.0–5.5 m s−1 in relation to inlet velocity of 4.4 m s−1. From the results it was inferred that, with the increase of air inlet velocity and modified flow design, the non‐uniform areas occurring in flow field are reduced leading to uniform air distribution throughout the flow volume.
Prognosis and chemosensitivity of deficient MMR phenotype in patients with metastatic colorectal cancer: An AGEO retrospective multicenter study
Authors: Tougeron David , Sueur Benjamin , Zaanan Aziz , de la Fouchardiére Christelle , Sefrioui David , Lecomte Thierry , Aparicio Thomas , Des Guetz Gaetan , Artru Pascal , Hautefeuille Vincent , Coriat Romain , Moulin Valerie , Locher Christophe , Touchefeu Yann , Lecaille Cedric , Goujon Gael , Ferru Aurélie , Evrard Camille , Chautard Romain , Gentilhomme Lucie , Vernerey Dewi , Taieb Julien , André Thierry , Henriques Julie , Cohen Romain ,   for the Association des Gastro‐entérologues Oncologues (AGEO)
Published: January 2020

Mismatch repair‐deficient (dMMR) and/or microsatellite instability‐high (MSI) colorectal cancers (CRC) represent about 5% of metastatic CRC (mCRC). Prognosis and chemosensitivity of dMMR/MSI mCRC remain unclear. This multicenter study included consecutive patients with dMMR/MSI mCRC from 2007 to 2017. The primary endpoint was the progression‐free survival (PFS) in a population receiving first‐line chemotherapy. Associations between chemotherapy regimen and survival were evaluated using a Cox regression model and inverse of probability of treatment weighting (IPTW) methodology in order to limit potential biases. Overall, 342 patients with dMMR/MSI mCRC were included. Median PFS and overall survival (OS) on first‐line chemotherapy were 6.0 and 26.3 months, respectively. For second‐line chemotherapy, median PFS and OS were 4.4 and 21.6 months. Longer PFS (8.1 vs. 5.4 months, p = 0.0405) and OS (35.1 vs. 24.4 months, p = 0.0747) were observed for irinotecan‐based chemotherapy compared to oxaliplatin‐based chemotherapy. The association was no longer statistically significant using IPTW methodology. In multivariable analysis, anti‐VEGF as compared to anti‐EGFR was associated with a trend to longer OS (HR = 1.78, 95% CI 1.00–3.19, p = 0.0518), whatever the backbone chemotherapy used. Our study shows that dMMR/MSI mCRC patients experienced short PFS with first‐line chemotherapy with or without targeted therapy. OS was not different according to the chemotherapy regimen used, but a trend to better OS was observed with anti‐VEGF. Our study provides some historical results concerning chemotherapy in dMMR/MSI mCRC in light of the recent nonrandomized trials with immune checkpoint inhibitors.
Immobilization of nanocarriers within a porous chitosan scaffold for the sustained delivery of growth factors in bone tissue engineering applications
Authors: De Witte Tinke‐Marie , Wagner Angela M. , Fratila‐Apachitei Lidy E. , Zadpoor Amir A. , Peppas Nicholas A.
Published: January 2020

To guide the natural bone regeneration process, bone tissue engineering strategies rely on the development of a scaffold architecture that mimics the extracellular matrix and incorporates important extracellular signaling molecules, which promote fracture healing and bone formation pathways. Incorporation of growth factors into particles embedded within the scaffold can offer both protection of protein bioactivity and a sustained release profile. In this work, a novel method to immobilize carrier nanoparticles within scaffold pores is proposed. A biodegradable, osteoconductive, porous chitosan scaffold was fabricated via the “freeze‐drying method,” leading to scaffolds with a storage modulus of 8.5 kPa and 300 μm pores, in line with existing bone scaffold properties. Next, poly(methyl methacrylate‐co‐methacrylic acid) nanoparticles were synthesized and immobilized to the scaffold via carbodiimide‐crosslinker chemistry. A fluorescent imaging study confirmed that the conventional methods of protein and nanocarrier incorporation into scaffolds can lead to over 60% diffusion out of the scaffold within the first 5 min of implantation, and total disappearance within 4 weeks. The novel method of nanocarrier immobilization to the scaffold backbone via carbodiimide‐crosslinker chemistry allows full retention of particles for up to 4 weeks within the scaffold bulk, with no negative effects on the viability and proliferation of human umbilical vein endothelial cells.