bluuebunny/crossref_metadata_2025 huggingface dataset:
Erkenntnisse aus den „Tunnel Seismic While Drilling” Messungen während des Vortriebs am Koralmtunnel Baulos KAT2
Authors: Chwatal Werner , Domenig Angela , Kostial Dieter , Rudel Thomas , Schlögel Günter , Katzianer Erhard , Wagner Hanns
Published: October 2021

The 32.9 km long Koralm tunnel (Austria) is the core piece of the Koralm railway and will be one of the longest railway tunnels worldwide after completion. At the longest construction section ”KAT2“ two approx. 17 km long parallel single‐track tunnels were driven by two double‐shield tunnel boring machines with a diameter of about 10 m. Accompanying the tunnelling of the two tubes, the continuous Tunnel Seismic While Drilling (TSWD) method was used shortly after the start of mechanical excavation in January 2013 until the final position was reached in February 2018. The aim was to consistently explore the rock mass up to 100 m in front of the tunnel face to detect faults and water‐bearing zones which were relevant for tunnel construction. Another purpose of the measurements was to reduce the number of exploration drillings ahead of the tunnel face. After an initial test phase of about 5000 m, where exploration drillings were continuously carried out parallel with TSWD, an advanced and optimized exploration concept was evaluated and performed for permanent operation. This paper summarizes the findings gained from the TSWD measurements at this tunnel site.
S1 Tunnel Donau‐Lobau – Der komplexe Weg zur Baugrunderkundung im Nationalpark Donau‐Auen
Authors: Schröfelbauer Thomas , Permanschlager Katrin , Montag Oliver , Avender Thomas
Published: October 2021

The S1 Donau‐Lobau tunnel closes the gap in the road network around Vienna. Its two tunnel tubes run under the Danube and the Donau‐Auen National Park, with the provision that no work is allowed to take place on the surface of the site. The (hydro‐)geological subsurface conditions in the project area can be described as ”difficult“. The tunnel project must also meet all safety‐related requirements that arise during construction and operation, while at the same time minimizing the environmental impact.

This article describes the essential special civil engineering and tunnelling measures in connection with the local subsoil conditions. It outlines the geotechnical exploration goals required for the structural tendering and detailed planning as well as for limiting the subsoil risk. Just obtaining the necessary permits for the exploration work required extensive preparatory work. As a result, both the exploration programme and the tunnel itself have been further adapted. The approved explorations were completed in the shortest possible time in compliance with extensive environmental requirements during a single winter season.
Highly specialized geophysical methods for undergroud construction works – Semmering Base Tunnel, a practice report
Authors: Radinger Alexander , Hofmann Thomas , Holzer Robert , Fasching Florian , Kusnirak David
Published: October 2021

The use of geophysical methods for the planning of complex underground structures such as deep tunnels has made significant progress in the last two decades. The realization of large underground construction projects in complex geological environments has led to an increase of geophysical exploration during excavation activities, drilling, and geological documentation. The aim is to continuously update and improve the geological model in order to identify and mitigate potential risks. Flexible planning of geophysical measurements and their fast and efficient implementation are required to minimize the impact on ongoing construction works.

During construction of the Semmering Base Tunnel geophysical measurements were and are used to supplement exploratory drillings and tunnel documentation. This paper presents results from the construction lots SBT1.1 (Gloggnitz) and SBT3.1 (Grautschenhof) with an emphasis on carbonate prediction, and from the Göstritz cavern where sudden water ingress required an update of the geologic model. For each assignment a tailored‐made geophysical methodology was designed and applied.
Towards the integration of smart techniques for tunnel seismic applications
Authors: Dickmann Thomas , Hecht‐Méndez Jozsef , Krüger Dirk , Sapronova Alla , Unterlaß Paul Johannes , Marcher Thomas
Published: October 2021

Applications of seismic measurements for the prediction of hazard zones are applied practice in many tunnel drives in rock mass today. Next to a large exploration range and accurate localisation of discontinuities, seismic data provide attributes for a comprehensive characterisation of the ground conditions. A good synchronisation of all technical components is required to obtain optimum data quality and quantity while the tunnel excavation is not obstructed thereby. Firstly, the signal source must feed as much energy as possible into the rock in a very short time. Secondly, continuity of the signal generation with constant quality and its precise timing by means of wireless data transmission also ensure a reliable measurement process. Artificial intelligence is used to determine the quality of the recorded data already in the tunnel and feedback is given to the user keeping the data quality high. From the tunnel site, recorded raw data can be transferred to a cloud, from where an authorised processor collects them, wherever in the world. An immediately started data processing delivers a result within an hour that includes a geological forecast of up to 150 m of heading, depending on the rock mass condition. In addition to data quality, the quality of the results is crucial. Therefore, techniques are currently under development using machine learning to correlate and analyse seismic attributes with geological properties. This should lead to a more objective evaluation of the geological forecast in the future.
Anwendungsmöglichkeiten eines digitalen Baugrundmodells im Infrastrukturbau
Authors: Gächter Werner , Exenberger Hans , Fasching Alfred , Hillisch Stefan , Mulitzer Günther , Seywald Martin , Rettenbacher Martin , Fleischmann Gregor , Fröch Georg , Flora Matthias
Published: October 2021

The BIM pilot project ”New Köstendorf‐Salzburg Line“ for ÖBB‐Infrastruktur AG covers a new twin‐track section about 21 km long involving a wide variety of different engineering structures and a corresponding need for close interdisciplinary collaboration within a sensitive project space. The pilot project successfully achieved its objective of generating a largely software‐independent overall model and transferring the knowledge gained to the Employer's Information Requirements and subsequently to a BIM execution plan. In addition to internal coordination meetings, a preliminary external meeting took place to discuss the model elements required for a government agency as part of an approval process and the availability of such elements by means of direct access to the model.

By adopting an integrated, collaborative approach to project management, it was possible to define extensive procedures and workflows adapted to the needs of the respective project partners for the single‐discipline models (specialist models) and to coordinate an overall federated model. The results of the co‐ordinated overall model show the ample opportunities afforded by a parameterised ground model for transparent risk and project assessment, paving the way for a holistic, phase‐based infrastructure information model. In this regard, the authors felt that it was important to adapt the project partners' established internal procedures only minimally and to translate them into BIM‐compatible, cooperative workflows.
Organic geochemistry and petrology of the coals in the Laisong Formation, Naga Schuppen Belt, NE India: Inferences on hydrocarbon potential and depositional environment
Authors: Gogoi Mousumi , Walling Temsulemba , Thadoju Satish Kumar , Mathur Neeraj , Longkumer Limasanen , Phukan Sarat
Published: October 2021

The Oligocene Laisong Formation in the Naga Schuppen Belt is coal bearing along the Dimapur‐Kohima Road section, Nagaland. The coals are sulphurous and classified as lignite to sub‐bituminous ‘C’ based on various rank parameters. The coals are dominantly composed of vitrinite followed by inertinite and liptinite in order of abundance. The coals have high‐quality Type III kerogens derived mainly from angiosperm plants. The richness and quality of organic matter in the coal is excellent to act as a petroleum source rock. Most of the maturity parameters indicate that maturity ranges from immature to early mature. The biomarker parameters and facies critical maceral associations point to deposition of the coal‐bearing strata in non‐marine/terrestrial depositional environment under moist hydrodynamic conditions, possibly in an upper delta plain environment. However, the high sulphur content of the coal points to deposition in a lower delta plain environment. Comparison with other Palaeogene coal deposits of the same sedimentary basin shows that the Laisong coals contain lesser amount of liptinite macerals and much higher amount of sulphur than these deposits. All these deposits are of similar rank, however, the Laisong coals show marginally low thermal maturity from the viewpoint of hydrocarbon generation.
The trajectory of the medial longitudinal fasciculus in the human brain: A diffusion imaging‐based tractography study
Authors: Li Mengjun , Yeh Fang‐Cheng , Zeng Qingrun , Wu Xiaolong , Wang Xu , Zhu Zixin , Liu Xiaohai , Liang Jiantao , Chen Ge , Zhang Hongqi , Feng Yuanjing , Li Mingchu
Published: October 2021

The aim of this study is to investigate the trajectory of medial longitudinal fasciculus (MLF) and explore its anatomical relationship with the oculomotor nerve using tractography technique. The MLF and oculomotor nerve were reconstructed at the same time with preset three region of interests (ROIs): one set at the area of rostral midbrain, one placed on the MLF area at the upper pons, and one placed at the cisternal part of the oculomotor nerve. This mapping protocol was tested in an HCP‐1065 template, 35 health subjects from Massachusetts General Hospital (MGH), 20 healthy adults and 6 brainstem cavernous malformation (BCM) patients with generalized q‐sampling imaging (GQI)‐based tractography. Finally, the 200 μm brainstem template from Center for In Vivo Microscopy, Duke University (Duke CIVM), was used to validate the trajectory of reconstructed MLF. The MLF and oculomotor nerve were reconstructed in the HCP‐1065 template, 35 MGH health subjects, 20 healthy adults and 6 BCM patients. The MLF was in conjunction with the ipsilateral mesencephalic part of the oculomotor nerve. The displacement of MLF was identified in all BCM patients. Decreased QA, RDI and FA were found in the MLF of lesion side, indicating axonal loss and/or edema of displaced MLF. The reconstructed MLF in Duke CIVM brainstem 200 μm template corresponded well with histological anatomy. The MLF and oculomotor nerve were visualized accurately with our protocol using GQI‐based fiber tracking. This GQI‐based tractography is an important tool in the reconstruction and evaluation of MLF.
Low‐dose ketamine infusion in treatment‐resistant double depression: Revisiting the adjunctive ketamine study of Taiwanese patients with treatment‐resistant depression
Authors: Chen Mu‐Hong , Wu Hui‐Ju , Li Cheng‐Ta , Lin Wei‐Chen , Tsai Shih‐Jen , Hong Chen‐Jee , Tu Pei‐Chi , Bai Ya‐Mei , Mao Wei‐Chung , Su Tung‐Ping
Published: October 2021

Background

Whether a single low‐dose ketamine infusion may have rapid antidepressant and antisuicidal effects in patients with treatment‐resistant double depression remains unclear.

Methods

This study enrolled 35 patients with treatment‐resistant double depression, 12 of whom received 0.5 mg/kg ketamine, 11 received 0.2 mg/kg ketamine, and 12 received normal saline as a placebo. The patients were assessed using the 17‐item Hamilton Rating Scale for Depression (HDRS) prior to the initiation of infusions, at 40 and 240 min post‐infusion, and sequentially on Days 2–7 and on Day 14 after ketamine or placebo infusions.

Results

A single 0.5 mg/kg ketamine infusion had rapid antidepressant (p = 0.031, measured by the HDRS) and antisuicidal (p = 0.033, measured by the HDRS item 3 scores) effects in patients with treatment‐resistant double depression. However, 0.2 mg/kg ketamine was insufficient to exert rapid antidepressant and antisuicidal effects in this patient population with severe and chronic illness.

Discussion

In this patient population, the commonly used dose of 0.5 mg/kg was sufficient. Additional studies are required to investigate whether repeated infusions of low‐dose ketamine may also maintain antidepressant and antisuicidal effects in patients with treatment‐resistant double depression.
Transparent, Conducting Self‐Assembled CuS Nanostructures at and beyond Liquid‐Liquid Interface and their Electrocatalytic Properties
Authors: Tomar Yeshvi , Swaroop Pathak Sushil , Jain Siddarth , Panchakarla Leela S
Published: October 2021

The liquid‐liquid interface (LLI) technique has been used to form thin films of various materials parallel to the interface. In this report, by taking CuS as an example, we show that CuS not only adopts thin film structures at the liquid‐liquid interface parallel to the interface but can also utilize beyond the interface to form self‐supported vertically aligned CuS thin films by controlling the precursor concentration. We also report the formation of a self‐assembled monolayer of CuS nanoparticles in the dichlorobenzene‐water interface at a lower concentration of copper. Thin films generated at LLI show p‐type conductivity with a sheet resistance of ∼350 Ω/□ and transparency up to 72 % at 550 nm. CuS also show electrocatalytic activity towards glucose sensing with a sensitivity of 3958 μA mM−1 cm−2, which is among the best in copper‐based materials.
Improved hemocompatibility by modifying acellular blood vessels with bivalirudin and its biocompatibility evaluation
Authors: Du Pengchong , Li Xiafei , Sun Lulu , Pan Yuxue , Zhu Hengchao , Li Yangyang , Yang Yingjie , Wei Xieze , Jing Changqin , Chen Hongli , Shi Qizhong , Li Wenbin , Zhao Liang
Published: October 2021

The incidence rate of cardiovascular diseases is increasing year by year. The demand for coronary artery bypass grafting has been very large. Acellular blood vessels have potential clinical application because of their natural vascular basis, but their biocompatibility and anticoagulant energy need to be improved. We decellularized the abdominal aorta of SD rats, and then modified with bivalirudin via polydopamine. The mechanical properties, blood compatibility, cytocompatibility, immune response, and anticoagulant properties were evaluated, and then the bivalirudin‐modified acellular blood vessels were implanted into rats for remodeling evaluation in vivo. The results we got show that the bivalirudin‐modified acellular blood vessels showed good cytocompatibility and blood compatibility, and its anti‐inflammatory trend was dominant in the immune response. After 3 months of transplantation, the bivalirudin‐modified acellular blood vessels did not easily form thrombus. It was not easy to form calcification and could make the host cells grow better. Through vascular stimulation and immunofluorescence test, we found that vascular smooth muscle cells and endothelial cells proliferated well in the bivalirudin group. Bivalirudin‐modified acellular blood vessels provided new idea for small diameter tissue engineering blood vessels, and may become a potential clinical substitute for small‐diameter vascular grafts.
Ultrasound assessment of the inferior vena cava in children: A comparison of sub‐xiphoid and right lateral coronal views
Authors: Yamaguchi Yoshikazu , Moharir Alok , Kim Stephani S. , Wakimoto Mayuko , Burrier Candice , Shafy Shabana Z. , Hakim Mohammed , Tobias Joseph D.
Published: October 2021

Objectives

The inferior vena cava collapsibility index (IVCCI) has been used to assess the respiratory variation of the inferior vena cava (IVC) diameter and hence intravascular volume. The sub‐xiphoid view (SXV) is the standard view to evaluate the IVC. The right lateral transabdominal view (RLV) has been shown in adults to be an alternative view to evaluate the IVC when the SXV is not feasible. The aim of the study was to compare IVC dimensions from these two views and thus determine whether the RLV view can be used instead of the SXV in pediatric patients.

Methods

We conducted a single‐center prospective observational crossover study. Study subjects were ASA physical status 1–2 children, 1–12 years of age scheduled for elective surgery under general anesthesia. Anesthesia was maintained by mask with spontaneous ventilation with end‐tidal sevoflurane at 2%–5% after the induction of anesthesia. IVCCI was measured using M‐mode in both the SXV and RLV.

Results

The study cohort included 50 children with a mean age of 5.1 years. The median value for the IVCCI‐sx was 0.45 (IQR: 0.28–0.70) while the IVCCI‐rl was 0.30 (0.19–0.5). The mean difference between the two groups was 0.12 (95% CI: 0.177–0.066, p < .001, two‐tailed paired t‐test). Spearman's rank correlation coefficient was 0.66. The univariate linear regression model was IVCCIsx = 0.21 + 0.77 × IVCCIrl.

Conclusions

IVCCIrl was lower than IVCCIsx. IVCCI measured from the right lateral view tended to overestimate the patient's fluid‐responsiveness and therefore these two values are not interchangeable.
Energy in the Anthropocene: How the concept of energy shaped both our current crisis and its professed solution
Authors: Simon‐Stickley Anna
Published: October 2021

This essay traces how the concept of energy—defined as the ability to do work in physics—informed two similar fields of knowledge with very dissimilar results. One, the resource economy in the late 19th century, laid some important epistemic and ideological foundations for the destruction of the environment in the present. The other, ecology, introduced a new holistic view of nature, which laid the groundwork for the recent reconceptualization of ethics, epistemology, and humankind's role on Earth culminating in the Anthropocene hypothesis—formulated in direct opposition to the capitalist, anthropocentric notions inherited from the 19th century. In both cases, it was the concept of energy that enabled thinking about the multifarious visualities, materialities, and temporalities of natural phenomena as united in a single causal substructure of energy exchanges. In resource economics, the energetic worldview imposed an anthropocentric useful/useless divide on the environment—modeled, I argue, on the energy/entropy distinction—and made it “logical” to think of minerals, plants, and human labor as analogous resources, justifiably equated and linked in the economic system. The same ability to equate and connect was fundamental to the discipline of ecology and its application to sociology in the 20th century, and, in more recent years, to philosophy and historiography. In stripping nature of all surface illusions, energy proved enormously efficient for exposing the entanglement of large‐scale systems composed of animate and inanimate actors equally imbued with agency.
Authority commits to integrating services for military veterans
Authors: Enos Gary
Published: October 2021

The executive director of the Northeast Delta Human Services Authority (NDHSA) in northeast Louisiana says too many military veterans have experienced inadequate behavioral health care in traditional systems. The authority last month formally announced a veterans initiative that is grounded in its integrated service delivery model.
Temperature and velocity profiles along a singular interface between two immiscible fluids
Authors: Vanhaelen Quentin
Published: October 2021

Bedeaux, Albano, and Mazur (BAM) have developed a convenient method to derive the boundary conditions for non‐equilibrium thermodynamic systems made of two bulk phases separated by a free interface. In their description, the interface is considered as a thermodynamic system characterized by its intensive and extensive variables. The boundary conditions describing the free interface are expressed in terms of fluxes, thermodynamic forces, and interface transport coefficients. Previous works have focused on the derivation of the generalized boundary conditions for different systems using the BAM method, but the corresponding solutions and dynamics have not been widely studied. We consider a theoretical two dimensional system made of two incompressible fluids separated by a deformable interface for which the boundary conditions are obtained using the BAM method. Ignoring the effects of external forces, the dynamics of the system is investigated using the method of multiple scales. The hierarchy of equations is solved up to the second order and we obtain conditions that must be fulfilled by the transport coefficients modeling the cross‐effects of the velocity slips and temperature jumps so that non‐trivial asymptotic solutions for the temperature and velocity profiles can be constructed.
Elucidating the Binding Mode between Heparin and Inflammatory Cytokines by Molecular Modeling
Authors: Yu Mingjia , Zhang Tianji , Li Jin‐ping , Tan Yingxia
Published: October 2021

Heparan sulfate (HS) interacts with a broad spectrum of inflammatory cytokines, thereby modulating their biological activities. It is believed that there is a structural‐functional correlation between each protein and sugar sequences in the HS polysaccharides, however, the information in this regard is limited. In this study, we compared the binding of four inflammatory cytokines (CCL8, IL‐1beta, IL‐2 and IL‐6) to immobilized heparin by an SPR analysis. To define the molecular base of the binding, we used a heparin pentasaccharide as representative structure to dock into the 3D‐molecular structure of the cytokines. The results show a discrepancy in KD values obtained by SPR analysis and theoretical calculation, pointing to the importance to apply more than one method when describing affinity between proteins and HS. By cluster analysis of the complex formed between the pentasaccharide and cytokines, we have identified several groups in heparin forming strong hydrogen bonds with all four cytokines, which is a significant finding. This molecular and conformational information should be valuable for rational design of HS/heparin‐mimetics to interfere cytokine‐HS interactions.
Outcomes of intensification of induction chemotherapy for children with high‐risk acute myeloid leukemia: A report from the Children's Oncology Group
Authors: Elgarten Caitlin W. , Wood Andrew C. , Li Yimei , Alonzo Todd A. , Brodersen Lisa Eidenschink , Gerbing Robert B. , Getz Kelly D. , Huang Y‐S Vera , Loken Michael , Meshinchi Soheil , Pollard Jessica A. , Sung Lillian , Woods William G. , Kolb E. Anders , Gamis Alan S. , Aplenc Richard
Published: October 2021

Background

High‐risk pediatric acute myeloid leukemia confers a poor prognosis, and alternative strategies are needed to improve outcomes. We hypothesized that intensifying induction on the AAML1031 clinical trial would improve outcomes compared to the predecessor trial AAML0531.

Methods

Patients on AAML0531 received cytarabine (1600 mg/m2)/daunorubicin (150 mg/m2)/etoposide (ADE) for induction II and patients on AAML1031 received mitoxantrone (48 mg/m2)/cytarabine (8000 mg/m2) (MA). Stem cell transplant (SCT) conditioning included busulfan/cyclophosphamide on AAML0531, whereas AAML1031 used busulfan/fludarabine and liberalized donor eligibility. Patients were included in this analysis if they met high‐risk criteria common to the two trials by cytogenics or poor disease response after induction I ADE.

Results

MA provided no benefit over ADE at: induction II response (complete response [CR]: 64% vs. 62%, p = .87; measurable residual disease [MRD]+: 57% vs. 46%, p = .34); or intensification I response (CR: 79% vs. 94%, p = .27; MRD+: 27% vs. 20%, p = 1.0). When considered with altered SCT approach, MA did not improve 5‐year disease‐free survival (24% ± 9% vs. 18% ± 15%, p = .63) or 5‐year overall survival (35% ± 10% vs. 38% ± 18%, p = .66). MA was associated with slower neutrophil recovery (median 34 vs. 27 days, p = .007) and platelet recovery (median 29 vs. 24.5 days, p = .04) and longer hospital stay (32 vs. 28 days, p = .01) during induction II.

Conclusion

Intensification of induction II did not improve treatment response or survival, but did increase toxicity and resource utilization. Alternative strategies are urgently needed to improve outcomes for pediatric patients with high‐risk acute myeloid leukemia (trials registered at clinicaltrials.gov NCT01371981, NCT00372593).
Clonal dynamics in pediatric B‐cell precursor acute lymphoblastic leukemia with very early relapse
Authors: Antić Željko , Yu Jiangyan , Bornhauser Beat C. , Lelieveld Stefan H. , van der Ham Cedric G. , van Reijmersdal Simon V. , Morgado Lionel , Elitzur Sarah , Bourquin Jean‐Pierre , Cazzaniga Giovanni , Eckert Cornelia , Camós Mireia , Sutton Rosemary , Cavé Hélène , Moorman Anthony V. , Sonneveld Edwin , Geurts van Kessel Ad , van Leeuwen Frank N. , Hoogerbrugge Peter M. , Waanders Esmé , Kuiper Roland P.
Published: October 2021

Introduction

One‐quarter of the relapses in children with B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL) occur very early (within 18 months, before completion of treatment), and prognosis in these patients is worse compared to cases that relapse after treatment has ended.

Methods

In this study, we performed a genomic analysis of diagnosis–relapse pairs of 12 children who relapsed very early, followed by a deep‐sequencing validation of all identified mutations. In addition, we included one case with a good initial treatment response and on‐treatment relapse at the end of upfront therapy.

Results

We observed a dynamic clonal evolution in all cases, with relapse almost exclusively originating from a subclone at diagnosis. We identified several driver mutations that may have influenced the outgrowth of a minor clone at diagnosis to become the major clone at relapse. For example, a minimal residual disease (MRD)‐based standard‐risk patient with ETV6‐RUNX1‐positive leukemia developed a relapse from a TP53‐mutated subclone after loss of the wildtype allele. Furthermore, two patients with TCF3‐PBX1‐positive leukemia that developed a very early relapse carried E1099K WHSC1 mutations at diagnosis, a hotspot mutation that was recurrently encountered in other very early TCF3‐PBX1‐positive leukemia relapses as well. In addition to alterations in known relapse drivers, we found two cases with truncating mutations in the cohesin gene RAD21.

Conclusion

Comprehensive genomic characterization of diagnosis–relapse pairs shows that very early relapses in BCP‐ALL frequently arise from minor subclones at diagnosis. A detailed understanding of the therapeutic pressure driving these events may aid the development of improved therapies.
Tetramethyl guanidine‐assisted synthesis and thermal crosslinking of multifunctional benzoxazine monomers based on natural phloretic acid
Authors: Forchetti Casarino Agustin , Moreno Adrián , Galià Marina , Estenoz Diana A. , Lligadas Gerard , Spontón Marisa E.
Published: October 2021

An efficient strategy to synthesize novel biobased multifunctional benzoxazine compounds was developed using the 1,1,3,3‐tetramethyl guanidine (TMG)‐triggered esterification of natural phloretic acid with organic halides as a key synthetic step. First, phloretic acid was combined with either aniline or furfurylamine to prepare the corresponding carboxylic acid‐functional monobenzoxazine monomer. Next, the use of TMG enabled an efficient esterification of these compounds with di‐, tri‐, and tetra‐functional benzyl bromide compounds at room temperature to afford a series of new multi‐benzoxazine monomers tethered to an aromatic core. The effect of the functionality of the monomers on the curing process was analyzed, indicating that the reactivity during the thermally induced ring‐opening increases with the number of furan and oxazine rings in the monomers. The resulting thermosets revealed good correlation between the number of oxazine rings in the structure of the monomer and the properties of the crosslinked materials. Furfurylamine‐based polybenzoxazines showed improved thermal behavior compared to the aniline‐based systems, due to the role of furan rings. All materials showed high Tg, good thermal stability, and promising flame retardancy properties.
Compositional gradients at the nanoscale in substoichiometric thin films deposited by magnetron sputtering at oblique angles: A case study on SiOx thin films
Authors: Garcia‐Valenzuela Aurelio , Alcaide Antonio M. , Rico Victor , Ferrer Francisco J. , Alcala German , Rojas Teresa C. , Alvarez Rafael , Gonzalez‐Elipe Agustin R. , Palmero Alberto
Published: October 2021

We demonstrate the existence of stoichiometric variations at the nanoscale when growing nanocolumnar SiOx thin films by reactive magnetron sputtering deposition at oblique angles. Results show stoichiometric variations in the range 0.3 < x < 1.3 when growing a SiO0.5 thin film. This agrees with results from a numerical growth model that obtains a shift of the stoichiometry in all nanocolumns from lower values at the side facing the Si target to higher values at the opposite side. The different momentum distribution of the gaseous reactive and sputtered species results in preferential incorporation of the latter at a particular side of the nanocolumns. The general occurrence of this mechanism during the reactive magnetron sputtering deposition of substoichiometric thin films at oblique angles is discussed.
Dual Copper (II) Complex Supported on Diatomite as a Novel and Green Catalyst for the Synthesis of Dihydropyrano[3;2‐b]Chromenediones and Aminopyranopyrans
Authors: Davoodi Elham , Tahanpesar Elham , Massah Ahmad Reza
Published: October 2021

Immobilized copper (II) complex, namely, 2,2′‐((1E,1′E)‐((6‐(l2‐azaneyl)‐1,3,5‐triazine‐2,4‐diyl)bis(azaneylylidene))bis(methaneylylidene))diphenol, supported on diatomite (Diatomite‐Si‐Pr‐TAT‐Bis‐(AZY‐MY)(Cu)Phenol) was introduced as a robust and heterogeneous catalyst for the synthesis of dihydropyrano[3;2‐b]chromenediones and aminopyranopyrans. The Diatomite‐Si‐Pr‐TAT‐Bis‐(AZY‐MY)(Cu)Phenol catalyst was synthesized by complexation of copper (II) acetate with TAT‐Bis‐(AZY‐MY)Phenol as a ligand with oxygen and nitrogen ligation sites that were anchored on diatomite through 3‐chloropropyltrimethoxysilane. The prepared catalyst was characterized using different microscopic and spectroscopic techniques including SEM, TEM, EDX, XRD, FT‐IR, TGA and ICP. The diatomite is available and cheap support with a high specific surface area and a large amount of hydroxyl group on the surface. A large amount of dual copper (II) complexes were supported on diatomite through covalent bonds. The Diatomite‐Si‐Pr‐TAT‐Bis‐(AZY‐MY)(Cu)Phenol showed good catalytic activity for the synthesis of dihydropyrano[3;2‐b]chromenediones and aminopyranopyrans using aromatic aldehyde, kojic acid, dimedone, or malononitrile. In addition, this catalyst system was reusable for five consecutive catalytic cycles without loss of their catalytic activity.
Headspace Gas Chromatographic Method for Carbonate Content Determination in Layered Double Hydroxides
Authors: Li Hailong , Du Chao , Liu Mengru , Zeng Jingshan
Published: October 2021

The determination of carbonate content is the basic procedure for studies related to layer double hydroxides (LDHs). This paper reports a rapid and accurate headspace gas chromatographic (HS‐GC) technique for the determination of carbonate content in LDHs. The content of carbonate was expressed by the amount of CO2 generated by the reaction of sulfuric acid and carbonate, which can be measured by HS‐GC technique using a thermal conductivity detector. It was found that a complete conversion of carbonate to CO2 can be achieved at 45 °C for about 4 min and a sulfuric acid dosage of 200 μL in the headspace vial. Under optimized conditions, the limit of detection and relative standard deviation of HS‐GC method is 0.79 μmol and 1 %, respectively.
Dendritic Silica Nanospheres Loaded with Red‐Emissive Enhanced Carbon Dots for Zika Virus Immunoassay
Authors: Xu Lai‐Di , Wang Si‐Wen , Zhu Jin , Zhou Tingting , Ding Shou‐Nian
Published: October 2021

Enhanced red emissive carbon dots (CDs) and their enrichment in spheres are ideal for sensing applications. Here, we propose a novel strategy for enhancing the red emission of CDs and enriching it in dendritic SiO2 nanospheres. The surface carboxylated and red emissive CDs obtained by alkali/acid treatment of blue emissive CDs are dissolved in N‐β‐(aminoethyl)‐γ‐aminopropyltrimethoxysilane for silanization. Electron injection and long chain passivation greatly enhance the red emission of CDs. Through the reaction of silane with the hydroxyl groups of dendritic SiO2 spheres, the silanized CDs can be enriched in dendritic SiO2 spheres. Encapsulation of composite spheres with (3‐Aminopropyl)‐trimethoxysilane protects CDs and facilitates bioconjugation. These fluorescence SiO2 spheres exhibit high quantum yields in red emission (48.5 % for aqueous solution and 35.7 % for solid state) and maintain good monodispersity. It is further used as a signal of lateral flow test strips to target Zika virus, and demonstrates an ultra‐sensitive, specific and effective immunoassay. And considerable results have been achieved in the analysis of actual samples.
Hemilabile Properties of Sulfur‐Containing Cymantrene Derivatives
Authors: Kelbysheva Elena S. , Ezernitskaya Mariam G. , Strelkova Tatyana V. , Borisov Yurii A. , Telegina Lyudmila N.
Published: October 2021

Sulfur‐containing cymantrene derivatives having one or two organometallic moieties were studied by NMR, IR, UV/Vis spectroscopic methods and CVA under irradiation conditions. Photolysis of compounds 1–3 leads to the formation of rare 4‐membered chelates 4, 5 and 8. In the presence of external ligand (L), dissociation of the Mn−S bond occurred to form new dicarbonyl complexes with the Mn−L bond, which demonstrates the hemilabile character of the chelates obtained. The results were confirmed by DFT calculations. CVA method showed manganese oxidation potential value increased in the case of dicarbonyls (1313 mV for 4) as compared to that of tricarbonyls (1067 mV for 1).
Colloidal Crystal Thin Films with Square Lattice Nanoprotrusions Formed by Self‐Assembly via Spin‐Coating and Heating
Authors: Kuno Goshi , Sakaguchi Kota , Matsumoto Akikazu
Published: October 2021

Colloidal crystals with non‐close‐packed structures, such as body‐centered cubic (bcc) structures, are of high interest. Nanosized protrusions, prepared from colloidal crystals, are interesting for biomimetic applications. Herein, self‐assembly approaches for synthesizing colloidal crystals with square lattice nanoprotrusions are presented. In the first approach, spin‐coating and subsequent heating of colloidal silica and acrylic monomer results in a bcc‐like arrangement; the number of stacked colloid layers and the colloid density of these compounds are important in the formation of this structure. Moreover, prolonged heating exposes colloids from acrylic monomer, with square lattice nanoprotrusions formed. In the second approach, the protrusions are fabricated in a shorter time by replacing some of the acrylic monomer with volatile media. Only certain volatile media, such as a solvent with a structure similar to diethylene glycol, exhibit the formation of square lattice protrusions. These bottom‐up approaches contribute toward high‐throughput techniques for fabricating metastable square lattice colloidal arrangements.
Photocatalytic Properties and Electronic Effects of Incorporation Bis(acetylacetonato) Ruthenium(II/III) Complexes with Bidentate Nitrogen and Sulfur Ancillaries
Authors: Chen Chong , Tang Li H. , Zhou Wen Y. , Jia Ai Q. , Zhang Qian F.
Published: October 2021

Treatment of cis‐[Ru(acac)2(CH3CN)2] (acac−=acetylacetonate) with 1.5 equiv. of corresponding bidentate nitrogen and sulfur ligands in ethanol gave a series of bis(acetylacetonato) ruthenium(II/III) complexes [(acac)2Ru(dimbpy)](PF6) (dimbpy=4,4′‐dimethyl‐2,2′‐bipyridine) (1), [(acac)2Ru(phen)] (phen=o‐phenanthroline) (2), [(acac)2Ru(opd)] (opd=o‐phenylenediamine) (3), [(acac)2Ru(4‐Bropd)] (4‐Bropd=4‐bromo‐o‐phenylenediamine) (4) and [(acac)2Ru(S2CNMe2)] (5), respectively. Complexes 1–5 were characterized by FT‐IR, NMR and UV‐Vis spectroscopies along with their electrochemical properties. The structures of complexes 1–5 have been unambiguously established by single crystal X‐ray crystallography. The photocatalytic properties for hydrogen production by water splitting of complexes 1–5 under visible light (λ>420 nm) were also investigated in the paper.
Regio‐ and Chemoselectivity of Oxidative Conversion of Diarylamines to N,N’‐Diaryldihydrophenazines and N,N’‐Diarylbenzidines: DFT and Experimental Study
Authors: Dulov Dmitry , Rumyantseva Anna , Levitskiy Oleg , Nefedov Sergey , Magdesieva Tatiana
Published: October 2021

Detailed quantum‐chemical investigation of competing routes of substituted diphenylamines oxidation was performed. Chemoselectivity as well regioselectivity of the phenazine and benzidine skeletons formation were elucidated and confirmed by experimental testing on the model diphenylamines containing CF3, But, α‐methylcyclopropyl substituents. It was shown that the oxidation of 4,4’‐disubstituted donor‐acceptor amines leads to dihydrophenazines chemo‐ and regioselectively. For 2,4’‐disubstituted donor‐acceptor diphenylamines, the reaction rates for the competing reactions differ ca. 25 times in favor of the benzidine formation. Oxidation of 2,4’‐disubstituted diphenylamines with electron‐rich phenyl rings is much less selective; both benzidines and dihydrophenazines are formed. It was shown that the activation energy for the benzidines formation is strongly dependent on the electronic properties of the substituents in the starting amine, in contrast to the competing formation of the phenazines, which is more sensitive to sterical bulkiness of substituents.
Theoretical Studies on the Mechanism of the Formation of Cyclopentadienes and Dihydropyridazines
Authors: Hallooman Dhanashree , Rhyman Lydia , Dalkılıç Erdin , Daştan Arif , Elzagheid Mohamed I. , Domingo Luis R. , Ramasami Ponnadurai
Published: October 2021

The synthesis of cyclopentadiene derivatives via the domino reaction of norbornadienes with dimethyl 1,2,4,5‐tetrazine‐3,6‐dicarboxylate, followed a retro‐Diels‐Alder reaction, was reported by Dalkılıç few years ago (Tetrahedron 2015;71 : 1966). In some cases, the formation of an unexpected dihydropyridazine (DHP) was observed, and explained by a 1,3‐hydrogen shift. A density functional theory study is herein reported giving insights into the proposed mechanisms with different substituents on norbornadiene. Based on the kinetic and thermodynamic data, the retro‐Diels‐Alder reaction is confirmed to explain the formation of cyclopentadienes plus pyridazines. The intramolecular 1,3‐hydrogen shift mechanism was not sufficient to explain the exclusive formation of two DHPs. Thus, an alternative mechanism involving a stepwise tautomerisation is being reported for formation of DHPs.
Photoluminescent Carbon Nanodots Integrated Polymeric Materials in One Step from Molecular Precursors
Authors: Jalilov Almaz S.
Published: October 2021

The photoluminescence (PL) origin conundrum of the carbon nanodots (CNDs) is often restrained by the disconnect between the structural complexity of the CNDs in solid‐state versus the PL properties in the dispersed solution phase. Herein, the solid‐state photoluminescent polymeric materials synthesized by direct polyesterification of citric acid (CA) and glycols at 180 °C and 40 h. Characteristics of these polymeric materials were compared with the carbon nanodots (CNDs) prepared from direct pyrolysis of CA at similar conditions. The polymeric materials prepared with an excess of CA possess a higher yield of CA decomposition products such as molecular acids that are trapped in the polymer matrix, therefore, observe district structural and photophysical properties from the CNDs dispersed in solution. By comparing the structural and photophysical properties of the dispersed CNDs in dioxane, with those polymeric materials prepared by a single pot from CA and glycols, it is proposed that the intermediate molecular fluorophores can be trapped along with CNDs in the polymer matrix.
The Synthesis of Tetrasubstituted Cycloalkenes Bearing π‐Conjugated Substituents and Their Optical Properties
Authors: Čubiňák Marek , Bigeon John , Galář Pavel , Ondič Lukáš , Tobrman Tomáš
Published: October 2021

We report the development of a new methodology for the preparation of cyclic tetrasubstituted alkenes with π‐conjugated substituents. The synthesis of the target compounds was accomplished through the regioselective cross‐coupling reaction of diphenyl bromocyclohexenyl phosphate with organozinc reagents. The procedure succeeded in the preparation of alkenes with two pyrene moieties. The absorption and photoluminescence spectra of the prepared compounds were measured.
A Series of Primary Alkylamine Borane Adducts CxH2x+1NH2BH3: Synthesis and Properties
Authors: Turani‐I‐Belloto Kevin , Valero‐Pedraza María‐José , Chiriac Rodica , Toche François , Granier Dominique , Cot Didier , Petit Eddy , Yot Pascal G. , Alauzun Johan G. , Demirci Umit B.
Published: October 2021

Primary alkylamine borane adducts CxH2x+1NH2BH3 (CxAB) are unconventional molecules that may offer great opportunities in chemistry owing to their dihydrogen Hδ+⋅⋅⋅Hδ− bonds. Herein, we focus on six CxAB (x=4, 6, 8, 10, 12, 14), synthesized by Lewis acid‐base reaction between the complex (CH3)2S⋅BH3 and the primary alkylamines. At ambient temperature, C4AB and C6AB are oily liquid, and the other adducts are crystalline solids. The melting temperatures of the CxAB linearly increase as a function of ln(x) due to stronger intermolecular Van der Waals forces between the alkyl chains, and they are higher by 20–40 °C than those of the amines due to dihydrogen Hδ+⋅⋅⋅Hδ− bonds between the NH2BH3 heads. The occurrence of dihydrogen Hδ+⋅⋅⋅Hδ− bonds is further confirmed by molecular and structural analyses. This is discussed hereafter.
Understanding the Role of CdTe in Polycrystalline CdSexTe1–x/CdTe‐Graded Bilayer Photovoltaic Devices
Authors: Shah Akash , Pandey Ramesh , Nicholson Anthony , Lustig Zach , Abbas Ali , Danielson Adam , Walls John , Munshi Amit , Sampath Walajabad
Published: October 2021

Grading of bandgap by alloying CdTe with selenium to form a CdSexTe1–x/CdTe‐graded bilayer device has led to a device efficiency over 19%. A CdSexTe1–xabsorber would increase the short‐circuit current due to its lower bandgap but at the expense of open‐circuit voltage. It has been demonstrated that adding a CdTe layer at the back of such a CdSexTe1–xfilm reduces the voltage deficit caused by the lower bandgap of absorber from selenium alloying while maintaining the higher short‐circuit current. This leads to a photovoltaic device that draws advantage from both materials with an efficiency greater than either of them. Herein, a detailed account using device data, ultraviolet photoelectron spectroscopy, electron microscopy, and first‐principles density functional theory modeling is provided, which shows that CdTe acts as an electron reflector for CdSexTe1–x.
Magnetic quivers from brane webs with O7+-planes
Authors: Akhond Mohammad , Carta Federico
Published: October 2021

Abstract

We consider the Higgs branch of 5d fixed points engineered using brane webs with an O7+-plane. We use the brane construction to propose a set of rules to extract the corresponding magnetic quivers. Such magnetic quivers are generically framed non-simply-laced quivers containing unitary as well as special unitary gauge nodes. We compute the Coulomb branch Hilbert series of the proposed magnetic quivers. In some specific cases, an alternative magnetic quiver can be obtained either using an ordinary brane web or a brane web with an O5-plane. In these cases, we find a match at the level of the Hilbert series.
A non-relativistic limit of M-theory and 11-dimensional membrane Newton-Cartan geometry
Authors: Blair Chris D. A. , Gallegos Domingo , Zinnato Natale
Published: October 2021

Abstract

We consider a non-relativistic limit of the bosonic sector of eleven-dimensional supergravity, leading to a theory based on a covariant ‘membrane Newton-Cartan’ (MNC) geometry. The local tangent space is split into three ‘longitudinal’ and eight ‘transverse’ directions, related only by Galilean rather than Lorentzian symmetries. This generalises the ten-dimensional stringy Newton-Cartan (SNC) theory. In order to obtain a finite limit, the field strength of the eleven-dimensional four-form is required to obey a transverse self-duality constraint, ultimately due to the presence of the Chern-Simons term in eleven dimensions. The finite action then gives a set of equations that is invariant under longitudinal and transverse rotations, Galilean boosts and local dilatations. We supplement these equations with an extra Poisson equation, coming from the subleading action. Reduction along a longitudinal direction gives the known SNC theory with the addition of RR gauge fields, while reducing along a transverse direction yields a new non-relativistic theory associated to D2 branes. We further show that the MNC theory can be embedded in the U-duality symmetric formulation of exceptional field theory, demonstrating that it shares the same exceptional Lie algebraic symmetries as the relativistic supergravity, and providing an alternative derivation of the extra Poisson equation.
Effectiveness of phosphorus control under extreme heatwaves: implications for sediment nutrient releases and greenhouse gas emissions
Authors: Zhan Qing , Stratmann Cleo N. , van der Geest Harm G. , Veraart Annelies J. , Brenzinger Kristof , Lürling Miquel , de Senerpont Domis Lisette N.
Published: October 2021

Eutrophication has been identified as the primary cause of water quality deterioration in inland waters worldwide, often associated with algal blooms or fish kills. Eutrophication can be controlled through watershed management and in-lake measures. An extreme heatwave event, through its impact on mineralization rates and internal nutrient loading (phosphorus—P, and nitrogen—N), could counteract eutrophication control measures. We investigated how the effectiveness of a nutrient abatement technique is impacted by an extreme heatwave, and to what extent biogeochemical processes are modulated by exposure to heatwaves. To this end, we carried out a sediment-incubation experiment, testing the effectiveness of lanthanum-modified bentonite (LMB) in reducing nutrients and greenhouse gas emissions from eutrophic sediments, with and without exposure to an extreme heatwave. Our results indicate that the effectiveness of LMB may be compromised upon exposure to an extreme heatwave event. This was evidenced by an increase in concentration of 0.08 ± 0.03 mg P/L with an overlying water volume of 863 ± 21 mL, equalling an 11% increase, with effects lasting to the end of the experiment. LMB application generally showed no effect on nitrogen species, while the heatwave stimulated nitrification, resulting in ammonium loss and accumulation of dissolved oxidized nitrogen species as well as increased dissolved nitrous oxide concentrations. In addition, carbon dioxide (CO2)-equivalent was more than doubled during the heatwave relative to the reference temperature, and LMB application had no effect on mitigating them. Our sediment incubation experiment indicates that the rates of biogeochemical processes can be significantly accelerated upon heatwave exposure, resulting in a change in fluxes of nutrient and greenhouse gas between sediment and water. The current efforts in eutrophication control will face more challenges under future climate scenarios with more frequent and intense extreme events as predicted by the IPCC.