bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a new 3D‐printed joint plug
Authors: Tayebi Lobat , Cui Zhanfeng , Ye Hua
Published: August 2019

This paper introduces a kit of parts as a novel three‐dimensional (3D)–printed joint plug, in which each of the parts function cooperatively to treat cartilage damage in joints of the human body (e.g., hips, wrists, elbow, knee, and ankle). Three required and one optional parts are involved in this plug. The first part is a 3D‐printed hard scaffold (bone portion) to accommodate bone cells, and the second is a 3D‐printed soft scaffold (cartilage portion) overlying the bone portion to accommodate chondrocytes. The third part of joint plug is a permeable membrane, termed film, to cover the entire plug to provide coordinated sliding of the joint during the regeneration of the cartilage. Film is also responsible for retention of the chondrocytes while allowing nutrients to diffuse through the membrane. The plug may further include a fourth part, called barrier, which is a membrane to assist the bone portion in avoiding the loss of chondrocytes from the cartilage portion beyond the barrier. Various engagement means among the parts of the plug are assumed, which are discussed in this paper. Moreover, the detailed design criteria and selection of suitable materials for different parts are elaborated. The 3D‐printing practice allows the plug to be personalized and fabricated to fit the shape/size of the target joint and the injured section. Also discussed are the configuration options of the plug to be surgically implanted in a joint. Although the focus of this paper is on the design, a brief overview of a prototype is presented.
The effect of porosity on elastic moduli of polymer foams
Authors: Drozdov A. D. , de Claville Christiansen J.
Published: August 2019

Constitutive equations are reported for the effect of porosity on the elastic moduli and longitudinal sound speed of polymer foams. These relations are grounded on the asymptotic homogenization method combined with the integration embedding scheme. Observations are analyzed on open‐cell and closed‐cell porous polymers manufactured by (1) foaming with chemical blowing agents, (2) foaming with inert gases, and (3) emulsion‐templating foaming. Numerical analysis of experimental data shows that changes in the elastic moduli with porosity are correctly predicted by the governing relations for foams with spherical voids. Porous polydimethylsiloxane (PDMS) elastomers prepared by the emulsion‐templating method provide an exception from this rule. The difference between these materials and the other cellular polymers is caused by production of hydrogen gas under curing, which induces severe deformation of pores. Simulation reveals that experimental data on cellular PDMS elastomers are described by the differential equations for foams with spheroidal voids whose aspect ratio depends on porosity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48449.
Vorgespannte Bauteile im konstruktiven Holzbau
Authors: Geßner Stephan , Spelter Arne , Walter Burkhard , Judt Peter , Hegger Josef
Published: August 2019

Das Prinzip der Vorspannung wird im Stahlbetonbau häufig eingesetzt, um schlanke Tragkonstruktionen oder große Spannweiten zu ermöglichen. Im Rahmen eines Forschungsvorhabens wurde das Prinzip der Vorspannung auf den konstruktiven Holzbau angewendet und deren Einfluss auf Tragfähigkeit, baudynamisches Verhalten und Bauteilverformungen untersucht. Die Verankerung der Spannkräfte wurde mittels Betonverankerungskörper realisiert, die das Prinzip der Vorspannung mit sofortigem Verbund verwenden. Der Beitrag beschreibt die theoretischen Untersuchungen zur Bemessung von vorgespannten Brettstapeldecken, die experimentellen Untersuchungen zur Entwicklung der Betonverankerungskörper, Großversuche zur Untersuchung der Tragfähigkeit und des Dauerstandverhaltens von vorgespannten Holzbauteilen sowie baudynamische Untersuchungen. Die Untersuchungen zeigen, dass durch eine Vorspannung das Verformungsverhalten von Brettstapelelementen verbessert werden kann, während das statische und dynamische Tragverhalten durch die Vorspannung kaum beeinflusst wird.
Latest Advances on Bacterial Cellulose‐Based Materials for Wound Healing, Delivery Systems, and Tissue Engineering
Authors: Carvalho Tiago , Guedes Gabriela , Sousa Filipa L. , Freire Carmen S. R. , Santos Hélder A.
Published: August 2019

Bacterial cellulose (BC) is a nanocellulose form produced by some nonpathogenic bacteria. BC presents unique physical, chemical, and biological properties that make it a very versatile material and has found application in several fields, namely in food industry, cosmetics, and biomedicine. This review overviews the latest state‐of‐the‐art usage of BC on three important areas of the biomedical field, namely delivery systems, wound dressing and healing materials, and tissue engineering for regenerative medicine. BC will be reviewed as a promising biopolymer for the design and development of innovative materials for the mentioned applications. Overall, BC is shown to be an effective and versatile carrier for delivery systems, a safe and multicustomizable patch or graft for wound dressing and healing applications, and a material that can be further tuned to better adjust for each tissue engineering application, by using different methods.
Development of a 3D Tissue‐Engineered Skeletal Muscle and Bone Co‐culture System
Authors: Wragg Nicholas M. , Mosqueira Diogo , Blokpeol‐Ferreras Lia , Capel Andrew , Player Darren J. , Martin Neil R. W. , Liu Yang , Lewis Mark P.
Published: August 2019

In vitro 3D tissue‐engineered (TE) structures have been shown to better represent in vivo tissue morphology and biochemical pathways than monolayer culture, and are less ethically questionable than animal models. However, to create systems with even greater relevance, multiple integrated tissue systems should be recreated in vitro. In the present study, the effects and conditions most suitable for the co‐culture of TE skeletal muscle and bone are investigated. High‐glucose Dulbecco's modified Eagle medium (HG‐DMEM) supplemented with 20% fetal bovine serum followed by HG‐DMEM with 2% horse serum is found to enable proliferation of both C2C12 muscle precursor cells and TE85 human osteosarcoma cells, fusion of C2C12s into myotubes, as well as an upregulation of RUNX2/CBFa1 in TE85s. Myotube formation is also evident within indirect contact monolayer cultures. Finally, in 3D co‐cultures, TE85 collagen/hydroxyapatite constructs have significantly greater expression of RUNX2/CBFa1 and osteocalcin/BGLAP in the presence of collagen‐based C2C12 skeletal muscle constructs; however, fusion within these constructs appears reduced. This work demonstrates the first report of the simultaneous co‐culture and differentiation of 3D TE skeletal muscle and bone, and represents a significant step toward a full in vitro 3D musculoskeletal junction model.
Comprehensive structural modeling and preparation of human 5‐HT2A G‐protein coupled receptor in functionally active form
Authors: Mozumder Sukanya , Bej Aritra , Srinivasan Krishnamoorthi , Mukherjee Sujoy , Sengupta Jayati
Published: August 2019

The serotonin 2A receptor (5‐HT2AR) is an important member of the G‐protein coupled receptor (GPCR) family involved in an array of neuromodulatory functions. Although the high‐resolution structures of truncated versions of GPCRs, captured in ligand‐bound conformational states, are available, the structures lack several functional regions, which have crucial roles in receptor response. Here, in order to understand the structure and dynamics of the ligand‐free form of the receptor, we have performed meticulous modeling of the 5‐HT2AR with the third intracellular loop (ICL3). Our analyses revealed that the ligand‐free ground state structure of 5‐HT2AR has marked distinction with ligand‐bound conformations of 5‐HT2 subfamily proteins and exhibits extensive backbone flexibility across the loop regions, suggesting the importance of purifying the receptor in its native form for further studies. Hence, we have standardized a strategy that efficiently increases the expression of 5‐HT2AR by infecting Sf9 cells with a very low multiplicity of infection of baculovirus in conjunction with production boost additive and subsequently, purify the full‐length receptor. Furthermore, we have optimized the selective over‐expression of glycosylated and nonglycosylated forms of the receptor merely by switching the postinfection growth time, a method that has not been reported earlier.
Why don't students recognize creative learning opportunities in a biomedical science program?
Authors: Kim Alice M. , Speed Caroline J. , Macaulay Janet O.
Published: August 2019

Creativity is a uniquely human trait and it is the force behind many modern advancements. Due to the rapid changes seen across the economy and society, creativity has become highly valued and is in increasing demand by employers. To prepare students to meet this demand, many education stakeholders (such as Monash University) have incorporated creativity into their ethos. However, preliminary analysis of the learning objectives of the Bachelor of Biomedical Science degree (program) at Monash University identified little reference to creativity, even though one of its Graduate Attributes is to become a “creative scholar.” The aims of this study were to ascertain the biomedical science students' perception of creativity in the program and to evaluate the program's core units (subjects) for creative learning opportunities. The data shows that students perceived a lack of creativity in the program. However, using Bloom's taxonomy's definition of create, an evaluation of the creative learning opportunities in the core Biomedical Science units identified the presence of a variety of creative opportunities. This discrepancy between student perceptions and learning opportunities lead to the question: Why do not students recognize creative learning opportunities? From the survey responses and mapping data, three reasons were identified: students' lack of awareness of a Graduate attribute, a lack of explicit reference to creativity at the program and unit level, and students' lack of understanding of creativity. © 2019 International Union of Biochemistry and Molecular Biology, 47(6):656–668, 2019.
A novel and nonderivatization method for the determination of valproic acid in human serum by two‐dimensional liquid chromatography
Authors: Liu Wei , Shang Xiang , Yao Shuyong , Wang Feng
Published: August 2019

A novel and robust two‐dimensional liquid chromatography with ultraviolet detection method (2D‐LC–UV) was developed and validated for high‐throughput determination of the concentrations of valproic acid (VPA) in human plasma. This 2D‐LC system was composed of a first‐dimensional LC column, a second‐dimensional LC column and an intermediate transfer column. The sample was directly injected into the 2D‐LC system after an easy protein precipitation treatment. After online preconcentration and primary separation by the first‐dimensional column, the target was captured by an intermediate column and then transferred to second‐dimensional column for analysis. The system transferred the target through “central cutting” mode whereby the drug peak was not subject to interference from the matrix. The analysis cycle time was completed within 7.0 min. Compared with other methods that have been developed, the analysis time was reduced and the operation was much easier without any derivatization. The calibration curve was linear over the 5.90–188.94 μg/ml range for the VPA concentrations. The intra‐day and inter‐day precisions were <5.6%. The recoveries were in the range from 95.2 to 98.0%. This method appears to be sensitive, precise, rapid and low‐cost for the quantification of VPA in serum sample.
Analysis of concordance with antiemetic guidelines in pediatric, adolescent, and young adult patients with cancer using a large‐scale administrative database
Authors: Bun Seiko , Kunisawa Susumu , Sasaki Noriko , Fushimi Kiyohide , Matsumoto Kimikazu , Yamatani Akimasa , Imanaka Yuichi
Published: August 2019

Object

The appropriate use of antiemetics is important for the prevention of chemotherapy‐induced nausea and vomiting (CINV); however, little is known about the rate of concordance with antiemetic guidelines for CINV in the field of pediatric, adolescent, and young adult.

Methods

Using the Diagnosis Procedure Combination system in Japan, we identified patients <30 years of age who were diagnosed with cancer between July 2010 and March 2016. We have assessed concordance with the ASCO antiemetic guidelines for each emetic risk category of chemotherapeutic drugs. Furthermore, we have assessed the risk factors of discordance with the antiemetic guidelines using a logistic regression.

Results

In total, 21 106 patients who underwent chemotherapy were included. The rates of concordance with the guidelines in each emetic risk category of chemotherapeutic drugs were 51.1% in high risk, ≥18 years of age; 21.5% in high risk, <18 years of age; 32.1% in moderate risk; 52.0% in low risk; and 51.6% in minimal risk. The main reason for the discordance was underuse of antiemetics, especially steroids. The factors for discordance were younger age, use of moderate and high emetic risk chemotherapeutic drugs, hematological malignancy, and brain tumor.

Conclusion

There is substantial scope to improve the antiemetic practice and reduce the risk of discordance with the antiemetic guidelines in pediatric, adolescent, and young adult patients. The risk factors are different from those in adults. Further investigations to evaluate the causes of discordance are warranted.
A feasible CT feature to differentiate focal‐type autoimmune pancreatitis from pancreatic ductal adenocarcinoma
Authors: He Chaobin , Rong Dailin , Hu Wanming , Cai Qian , Yang Qiuxia , Mao Yize , Zhang Rong , Li Shengping , Lv Yanchun
Published: August 2019

Background

To investigate whether the relative computed tomography (CT) value (rCT) of adjacent pancreatic parenchyma can distinguish focal‐type autoimmune pancreatitis (fAIP) from pancreatic ductal adenocarcinoma (PDAC).

Methods

A total of 13 patients with fAIP and 20 patients with PDAC were included in this study. The rCT was calculated as the ratio of the CT value of adjacent pancreatic parenchyma to that of muscle. The diagnostic performance of rCT for discriminating fAIP from PDAC was evaluated using receiver operating characteristic (ROC) analysis.

Results

Both fAIP and PDAC presented hyper‐fibrosis histologically and delayed enhancement on CT examination. Moreover, the pancreatic parenchyma of fAIP presented serious inflammation. The mean rCT of the parenchyma was significantly lower in fAIP than in PDAC in all phases. The best diagnostic performance of the rCT value was found in the pancreatic phase, with an area under the ROC curve of 0.912, while the areas under the ROC curve of the portal and delayed phases were 0.812 and 0.754, respectively. The optimal cut‐off value for distinguishing fAIP from PDAC was 1.62 in the pancreatic phase.

Conclusions

The rCT of the pancreatic parenchyma during the pancreatic phase may be a feasible CT feature for differentiating fAIP from PDAC.
Synthesis of Amido Sulfonamido Heteroaromatics Under Ultrasonication and Their Antimicrobial Activity
Authors: Gari Divya Kuppi Reddy , Lakshmi Teja Gaddam , Yamini Gudi , Padmaja Adivireddy , Padmavathi Venkatapuram
Published: August 2019

A convenient and facile methodology for N‐sulfonylation of heteroaryl amines with ethyl chlorosulfonylacetate in the presence of dispersed sodium in THF under ultrasonication is reported. The corresponding heteroaryl sulfonamido esters are directly condensed with heteroaryl amines to get amido sulfonamido heteroaromatics in the presence of a mild base in THF under ultrasonication. Utilization of easy reaction conditions, shorter reaction times, and isolation of products in high yields under ultrasonication make this process as economically viable. The compounds 12c, 12d, 12f and 13f are potential antibacterial agents against B. subtilis and the compounds 12f, 13c and 13f are potential antifungal agents against A. niger.
Lamprey Parapinopsin (“UVLamP”): a Bistable UV‐Sensitive Optogenetic Switch for Ultrafast Control of GPCR Pathways
Authors: Eickelbeck Dennis , Rudack Till , Tennigkeit Stefan Alexander , Surdin Tatjana , Karapinar Raziye , Schwitalla Jan‐Claudius , Mücher Brix , Shulman Maiia , Scherlo Marvin , Althoff Philipp , Mark Melanie D. , Gerwert Klaus , Herlitze Stefan
Published: August 2019

Optogenetics uses light‐sensitive proteins, so‐called optogenetic tools, for highly precise spatiotemporal control of cellular states and signals. The major limitations of such tools include the overlap of excitation spectra, phototoxicity, and lack of sensitivity. The protein characterized in this study, the Japanese lamprey parapinopsin, which we named UVLamP, is a promising optogenetic tool to overcome these limitations. Using a hybrid strategy combining molecular, cellular, electrophysiological, and computational methods we elucidated a structural model of the dark state and probed the optogenetic potential of UVLamP. Interestingly, it is the first described bistable vertebrate opsin that has a charged amino acid interacting with the Schiff base in the dark state, that has no relevance for its photoreaction. UVLamP is a bistable UV‐sensitive opsin that allows for precise and sustained optogenetic control of G protein‐coupled receptor (GPCR) pathways and can be switched on, but more importantly also off within milliseconds via lowintensity short light pulses. UVLamP exhibits an extremely narrow excitation spectrum in the UV range allowing for sustained activation of the Gi/o pathway with a millisecond UV light pulse. Its sustained pathway activation can be switched off, surprisingly also with a millisecond blue light pulse, minimizing phototoxicity. Thus, UVLamP serves as a minimally invasive, narrow‐bandwidth probe for controlling the Gi/o pathway, allowing for combinatorial use with multiple optogenetic tools or sensors. Because UVLamP activated Gi/o signals are generally inhibitory and decrease cellular activity, it has tremendous potential for health‐related applications such as relieving pain, blocking seizures, and delaying neurodegeneration.
Experimental models of maternal–fetal interface and their potential use for nanotechnology applications
Authors: de Araújo Thádia Evelyn , Milián Iliana Claudia Balga , de Souza Guilherme , da Silva Rafaela José , Rosini Alessandra Monteiro , Guirelli Pâmela Mendonça , Franco Priscila Silva , Barbosa Bellisa Freitas , Ferro Eloisa Amália Vieira , da Costa Idessania Nazareth
Published: August 2019

During pregnancy, the placenta regulates the transfer of oxygen, nutrients, and residual products between the maternal and fetal bloodstreams and is a key determinant of fetal exposure to xenobiotics from the mother. To study the disposition of substances through the placenta, various experimental models are used, especially the perfused placenta, placental villi explants, and cell lineage models. In this context, nanotechnology, an area of study that is on the rise, enables the creation of particles on nanometric scales capable of releasing drugs aimed at specific tissues. An important reason for furthering the studies on transplacental transfer is to explore the potential of nanoparticles (NPs), in new delivery strategies for drugs that are specifically aimed at the mother, the placenta, or the fetus and that involve less toxicity. Due to the fact that the placental barrier is essential for the interaction between the maternal and fetal organisms as well as the possibility of NPs being used in the treatment of various pathologies, the aim of this review is to present the main experimental models used in studying the maternal–fetal interaction and the action of NPs in the placental environment.
Multiple management strategies to prolong gestational period after radical trachelectomy
Authors: Ito Masami , Yoneda Satoshi , Shiozaki Arihiro , Fukuta Kaori , Yoneda Noriko , Saito Shigeru
Published: August 2019

Preterm premature rupture of membranes and massive genital bleeding in the second trimester are serious obstetrical problems in pregnancy after trachelectomy. We had managed a twin post‐trachelectomy pregnancy by multiple strategies, and two healthy infants were delivered at 32+5 weeks, although the optimum management for such patients is unknown.
Photocatalytic H2 Evolution: Dealloying as Efficient Tool for the Fabrication of Rh‐decorated TiO2 Nanotubes
Authors: Sheikhzadeh Mohsen , Hejazi Seyedsina , Mohajernia Shiva , Tomanec Ondrej , Mokhtar Mohamed , Alshehri Abdulmohsen , Sanjabi Sohrab , Zboril Radek , Schmuki Patrik
Published: August 2019

In this work, we report on a facile and novel method for decorating titanium dioxide (TiO2) nanotubes with Rh nanoparticle‐nanonetworks that act as co‐catalysts in photocatalytic H2 generation. In a first step, a Ti−Rh (0.2 at%) alloy is etched in Kroll's solution leading to a dealloyed surface decorated with a Rh nanoparticle‐network of adjustable geometry and loading. By subsequent anodization of the alloy samples, Rh:TiO2 nanotubes can be grown where the tube mouths are strongly decorated with the Rh nanoparticle network (RhNw). As evident from X‐ray photoelectron spectroscopy (XPS) analysis, these Rh oxide Nws are converted to metallic Rh under UV irradiation. As a result, with time a steady increase of the H2 evolution from the RhNw decorated TiO2 nanotubes is observed. Nanotubes carrying RhNw yield in photocatalytic experiments a 5‐times higher H2 evolution activity in comparison with nanotubes decorated by conventional Rh‐sputtering (the same loading), and show a 228 times higher activity than pristine TiO2 nanotubes.
Ultrafine Ag Nanoparticles as Active Catalyst for Electrocatalytic Hydrogen Production
Authors: Kang Wen‐Jing , Cheng Chuan‐Qi , Li Zhe , Feng Yi , Shen Gu‐Rong , Du Xi‐Wen
Published: August 2019

Ag nanoparticles with different sizes were produced by laser ablation in liquid (PLAL) through tuning laser energy. As the catalyst for hydrogen evolution reaction (HER) in acidic medium, Ag nanoparticles show strong size‐dependent activity, and the smallest Ag nanoparticles with average size of 3 nm display a low overpotential of 96 mV at 10 mA cm−2 and Tafel slope of 76.10 mV dec−1, being superior to Ag foil and commercial Ag powder. The excellent performance is attributed to the large exposed surface, low coordination number, moderate hydrogen adsorption energy, and low charge transfer resistance.
Chemical Mimics of Aspartate‐Directed Proteases: Predictive and Strictly Specific Hydrolysis of a Globular Protein at Asp−X Sequence Promoted by Polyoxometalate Complexes Rationalized by a Combined Experimental and Theoretical Approach
Authors: Ly Hong Giang T. , Mihaylov Tzvetan T. , Proost Paul , Pierloot Kristine , Harvey Jeremy N. , Parac‐Vogt Tatjana N.
Published: August 2019

Creating efficient and residue‐directed artificial proteases is a challenging task due to the extreme inertness of the peptide bond, combined with the difficulty of achieving specific interactions between the catalysts and the protein side chains. Herein we report strictly site‐selective hydrolysis of a multi‐subunit globular protein, hemoglobin (Hb) from bovine blood, by a range of ZrIV‐substituted polyoxometalates (Zr‐POMs) in mildly acidic and physiological pH solutions. Among 570 peptide bonds in Hb, selective cleavage was observed at only eleven sites, each occurring at Asp−X peptide bonds located in the positive patches on the protein surface. The molecular origins of the observed Asp−X selectivity were rationalized by means of molecular docking, DFT‐based binding, and mechanistic studies on model peptides. The proposed mechanism of hydrolysis involves coordination of the amide oxygen to ZrIV followed by a direct nucleophilic attack of the side chain carboxylate group on the C‐terminal amide carbon atom with formation of a cyclic anhydride, which is further hydrolyzed to give the reaction products. The activation energy for the cleavage of the structurally related Glu−X sequence compared to Asp−X was calculated to be higher by 1.4 kcal mol−1, which corresponds to a difference of about one order of magnitude in the rates of hydrolysis. The higher activation energy is attributed to the higher strain present in the six‐membered ring of glutaric anhydride (Glu−X), as compared to the five‐membered ring of the succinic anhydride (Asp−X) intermediate. Similarly, the cleavage at X−Asp and X−Glu bonds are predicted to be kinetically less likely as the corresponding activation energies were 6 kcal mol−1 higher, explaining the experimentally observed selectivity. The synergy between the negatively charged polyoxometalate cluster, which binds at positive patches on protein surfaces, and selective activation of Asp−X peptide bonds located in these regions by ZrIV ions, results in a novel class of artificial proteases with aspartate‐directed reactivity, which is very rare among naturally occurring proteases.
An Anionic Ring Locked into an Anionic Axle: A Metastable Rotaxane with Chemically Activated Electrostatic Stoppers
Authors: Luna‐Ixmatlahua Rubi A. , Carrasco‐Ruiz Anayeli , Cervantes Ruy , Vela Alberto , Tiburcio Jorge
Published: August 2019

The use of the electrostatic stoppers concept in the field of mechanically interlocked molecules is reported; these stoppers are chemically sensitive end groups on a linear guest molecule that allows for the conversion of a pseudo‐rotaxane species into a rotaxane complex by a change in the medium acidity. The chemical stimulus causes the appearance of negative charges on both ends of the linear component, passing from cationic to anionic, and causing a significant ring‐to‐axle electrostatic repulsion. This phenomenon has two different and simultaneous effects: 1) destabilizes the complex as a consequence of confining an anionic ring into an anionic axle, and 2) increases the dissociation energy barrier, thus impeding ring extrusion. This newly formed metastable rotaxane species is resistant to solvent and temperature effects and performs as a two‐state degenerated molecular shuttle in solution.
An Experimental Acidity Scale for Intramolecularly Stabilized Silyl Lewis Acids
Authors: Künzler Sandra , Rathjen Saskia , Merk Anastasia , Schmidtmann Marc , Müller Thomas
Published: August 2019

A new NMR‐based Lewis acidity scale is suggested and its application is demonstrated for a family of silyl Lewis acids. The reaction of p‐fluorobenzonitrile (FBN) with silyl cations that are internally stabilized by interaction with a remote chalcogenyl or halogen donor yields silylated nitrilium ions with the silicon atom in a trigonal bipyramidal coordination environment. The 19F NMR chemical shifts and the 1J(CF) coupling constants of these nitrilium ions vary in a predictable manner with the donor capability of the stabilizing group. The spectroscopic parameters are suitable probes for scaling the acidity of Lewis acids. These new probes allow for the discrimination between very similar Lewis acids, which is not possible with conventional NMR tests, such as the well‐established Gutmann–Beckett method.
Valence Photoionization of Thymine: Ionization Energies, Vibrational Structure, and Fragmentation Pathways from the Slow to the Ultrafast
Authors: Majer Katharina , Signorell Ruth , Heringa Maarten F. , Goldmann Maximilian , Hemberger Patrick , Bodi Andras
Published: August 2019

The photoionization of thymine has been studied by using vacuum ultraviolet radiation and imaging photoelectron photoion coincidence spectroscopy after aerosol flash vaporization and bulk evaporation. The two evaporation techniques have been evaluated by comparison of the photoelectron spectra and breakdown diagrams. The adiabatic ionization energies for the first four electronic states were determined to be 8.922±0.008, 9.851±0.008, 10.30±0.02, and 10.82±0.01 eV. Vibrational features have been assigned for the first three electronic states with the help of Franck–Condon factor calculations based on density functional theory and wave function theory vibrational analysis within the harmonic approximation. The breakdown diagram of thymine, as supported by composite method ab initio calculations, suggests that the main fragment ions are formed in sequential HNCO‐, CO‐, and H‐loss dissociation steps from the thymine parent ion, with the first step corresponding to a retro‐Diels–Alder reaction. The dissociation rate constants were extracted from the photoion time‐of‐flight distributions and used together with the breakdown curves to construct a statistical model to determine 0 K appearance energies of 11.15±0.16 and 11.95±0.09 eV for the m/z 83 and 55 fragment ions, respectively. These results have allowed us to revise previously proposed fragmentation mechanisms and to propose a model for the final, nonstatistical H‐loss step in the breakdown diagram, yielding the m/z 54 fragment ion at an appearance energy of 13.24 eV.
Adsorptive Separation of Acetylene from Ethylene in Isostructural Gallate‐Based Metal–Organic Frameworks
Authors: Wang Jiawei , Li Liangying , Guo Lidong , Zhao Yingcai , Xie Danyan , Zhang Zhiguo , Yang Qiwei , Yang Yiwen , Bao Zongbi , Ren Qilong
Published: August 2019

The separation of acetylene from ethylene is of paramount importance in the purification of chemical feedstocks for industrial manufacturing. Herein, an isostructural series of gallate‐based metal–organic frameworks (MOFs), M‐gallate (M=Ni, Mg, Co), featuring three‐dimensionally interconnected zigzag channels, the aperture size of which can be finely tuned within 0.3 Å by metal replacement. Controlling the aperture size of M‐gallate materials slightly from 3.69 down to 3.47 Å could result in a dramatic enhancement of C2H2/C2H4 separation performance. As the smallest radius among the studied metal ions, Ni‐gallate exhibits the best C2H2/C2H4 adsorption separation performance owing to the strongest confinement effect, ranking after the state‐of‐the‐art UTSA‐200a with a C2H4 productivity of 85.6 mol L−1 from 1:99 C2H2/C2H4 mixture. The isostructural gallate‐based MOFs, readily synthesized from inexpensive gallic acid, are demonstrated to be a new top‐performing porous material for highly efficient adsorption of C2H2 from C2H4.
Revefenacin, a Long‐Acting Muscarinic Antagonist, Does Not Prolong QT Interval in Healthy Subjects: Results of a Placebo‐ and Positive‐Controlled Thorough QT Study
Authors: Borin Marie T. , Barnes Chris N. , Darpo Borje , Pendyala Srikanth , Xue Hongqi , Bourdet David L.
Published: August 2019

Revefenacin is a novel once‐daily, lung‐selective, long‐acting muscarinic antagonist developed as a nebulized inhalation solution for the maintenance treatment of chronic obstructive pulmonary disease. In a randomized, 4‐way crossover study, healthy subjects received a single inhaled dose of revefenacin 175 µg (therapeutic dose), revefenacin 700 µg (supratherapeutic dose), and placebo via standard jet nebulizer, and a single oral dose of moxifloxacin 400 mg (open‐label) in separate treatment periods. Electrocardiograms were recorded, and pharmacokinetic samples were collected serially after dosing. The primary end point was the placebo‐corrected change from baseline QT interval corrected for heart rate using Fridericia's formula, analyzed at each postdose time. Concentration‐QTc modeling was also performed. Following administration of revefenacin 175  and 700 µg, placebo‐corrected change from baseline QTcF (ΔΔQTcF) values were close to 0 at all times, with the largest mean ΔΔQTcF of 1.0 millisecond (95% confidence interval [CI], −1.2 to 3.1 milliseconds) 8 hours postdose and 1.0 millisecond (95%CI, −1.1 to 3.1 milliseconds) 1 hour postdose after inhalation of revefenacin 175 and 700 µg, respectively. Revefenacin did not have a clinically meaningful effect on heart rate (within ±5 beats per minute of placebo), or PR and QRS intervals (within ±3 and ±1 milliseconds of placebo, respectively). Using concentration‐QTc modeling, an effect of revefenacin > 10 milliseconds can be excluded within the observed plasma concentration range of up to ≈3 ng/mL. Both doses of revefenacin were well tolerated. These results demonstrate that revefenacin does not prolong the QT interval.
Implications of Allee effects for fisheries management in a changing climate: evidence from Atlantic cod
Authors: Winter Anna‐Marie , Richter Andries , Eikeset Anne Maria
Published: August 2019

There are concerns that increasing anthropogenic stressors can cause catastrophic transitions in ecosystems. Such shifts have large social, economic, and ecological consequences and therefore have important management implications. A potential mechanism behind these regime shifts is the Allee effect, which describes the decline in realized per capita growth rate at small population density. With an age‐structured population model for Atlantic cod, Gadus morhua, we illustrate how interactions between human‐induced stressors, such as fishing and climate change, can worsen the impact of an Allee effect on populations by promoting hysteresis. Therefore, the risk of population collapse and recovery failure is exacerbated and the success of preventing and reverting collapse depends on the climate regime. We find that, in presence of the Allee effect, a fishing moratorium is only sufficient for recovery when sea surface temperature rise remains within 2°C and fishing is restricted within 10 yrs. If sea surface temperature rises beyond 2°C, even immediate banning of fishing is not sufficient to guarantee recovery. If fishing is not fully banned and a residual fishing pressure remains, the probability of recovery is further decreased, also in the absence of an Allee effect. The results underscore the decisive role of Allee effects for the management of depleted populations in an increasingly human‐dominated world. Once the population collapses and its growth rate is suppressed, rebuilding measures will be squandered and collapse will very likely be irreversible. We therefore emphasize the need for proactive management involving precautionary, adaptive measures and reference points. Our studies shows that climate change has the potential to strengthen Allee effects, which could increasingly challenge fisheries management.
Developing consensus on the definition of remission and recovery for research
Authors: Wade Tracey D. , Lock James
Published: August 2019

Objective

The current research investigated whether a consensus among professional eating disorder researchers existed for definitions of remission and recovery that could be used in research.

Method

Membership of the Eating Disorder Research Society and attendees at the 2018 annual meeting in Sydney were invited to participate in this investigation. Two surveys were conducted with 62 and 122 respondents, respectively. The first survey used a mix of forced choice yes/no or scaled responses. The second survey was a free response to the question “which definitions of recovery do you favor?”

Results

A majority consensus emerged about three issues. First, it was agreed that it was important to develop a standard definition of recovery for research purposes. Second, recovery needed to be evident over a 12‐month period, with remission evident over a 3‐ to 12‐month period. Third, recovery and remission required the absence of diagnostic criteria in addition to the presence of functional recovery.

Discussion

Consensus is apparent in the field. We suggest that future research seeks to: (a) validate the most commonly researched definition of remission and recovery across different eating disorders using a standardized battery of assessments, and (b) better understand differences in self‐assessed and psychometrically assessed recovery.
Novel Chiral PNNP Ligands with a Pyrrolidine Backbone – Application in the Fe‐Catalyzed Asymmetric Transfer Hydrogenation of Ketones
Authors: Mercadé Elisabet , Zangrando Ennio , Clotet Anna , Claver Carmen , Godard Cyril
Published: August 2019

The PNNP ligand (R,R)‐{PPh2(2‐C6H4)CH=N(pyrrolidine‐NBn)‐}2 2 was prepared by condensation between 2‐diphenylphosphino benzaldehyde and the pyrrolidine‐substituted diamine 1. Reduction with NaBH4 in MeOH afforded (R,R)‐{PPh2(2‐C6H4)CH–NH(pyrrolidine‐NBn)‐}2 3. The corresponding iron(II) complexes [FeCl2(2)] (4), [Fe(CH3CN)2(2)](BF4)2 (5) and [Fe(CH3CN)2(2)](PF6)2 (6) were synthesized and fully characterized by NMR, ESI‐HRMS, and EA. DFT calculations for complexes [FeCl2(2)] (4) and [Fe(CH3CN)2(2)](BF4)2 (5) were carried out in order to investigate the stability of related structures. The PNNP ligands 2 and 3 in combination with Fe3(CO)12 as iron source were tested as catalysts in the asymmetric transfer hydrogenation of a variety of ketones with conversions higher than 95 % and enantioselectivities up to 97 %.
The Groebke‐Blackburn‐Bienaymé Reaction
Authors: Boltjes André , Dömling Alexander
Published: August 2019

Imidazo[1,2‐a]pyridine is a well‐known scaffold in many marketed drugs, such as Zolpidem, Minodronic acid, Miroprofen and DS‐1 and it also serves as a broadly applied pharmacophore in drug discovery. The scaffold revoked a wave of interest when Groebke, Blackburn and Bienaymé reported independently a new three component reaction resulting in compounds with the imidazo[1,2‐a]‐heterocycles as a core structure. During the course of two decades the Groebke Blackburn Bienaymé (GBB‐3CR) reaction has emerged as a very important multicomponent reaction (MCR), resulting in over a hundred patents and a great number of publications in various fields of interest. Now two compounds derived from GBB‐3CR chemistry received FDA approval. To celebrate the first 20 years of GBB‐chemistry, we present an overview of the chemistry of the GBB‐3CR, including an analysis of each of the three starting material classes, solvents and catalysts. Additionally, a list of patents and their applications and a more in‐depth summary of the biological targets that were addressed, including structural biology analysis, is given.
Oxychalcogenide Perovskite Solar Cells: A Multiscale Design Approach
Authors: Park Heesoo , Baloch Ahmer A. B. , Bentria El Tayeb , Rashkeev Sergey N. , Alharbi Fahhad H. , El-Mellouhi Fedwa
Published: August 2019

Herein, a multiscale approach is used to design solar cells with oxychalcogenide perovskite absorbers by combining atomistic calculations and macroscale device simulations and optimization. The method involves the computation of charge carrier recombination time as well as the carriers' scattering time where lattice dynamics and multiple carrier scattering mechanisms are taken into account. Based on microscopically calculated parameters for the oxychalcogenide perovskites, a multiproperty optimization is performed to maximize the power conversion efficiency of the full device. This approach allows identifying optimal designs of some potential oxychalcogenide perovskite solar cells comprehensively. Herein, the methodology opens opportunities to accelerate lab realization and fabrication of solar cells with oxychalcogenide perovskite absorbers. Furthermore, the presented approach combines several general methods, and it should be highly beneficial in saving time and cost of device fabrication and optimization.
Progress of Triple Cation Organometal Halide Perovskite Solar Cells
Authors: Dong Chong , Wang Zhao-Kui , Liao Liang-Sheng
Published: August 2019

Organometal halide perovskites (PVSs) are a type of promising absorbing materials utilized in photovoltaic devices for their ambipolar charge carrier transporting properties, tunable bandgap, and solution processability. Among them, triple cation perovskites (TC‐PVSs) have attracted considerable research interest. Herein, TC‐PVSs are compared with conventional PVSs to demonstrate their superiority in phase stabilization and structural stability. In addition, surface treatment and structure adjustment methods are provided for device fabrication. Furthermore, the stability of TC‐PVSs and the corresponding devices are discussed, and the challenges and perspectives for large‐area flexible device manufacturing are provided. It is expected that this review could be helpful to understand the rapid development of TC‐PVS solar cells from more facets.
Analysis of the volatile compounds associated with pickling of ginger using headspace gas chromatography ‐ ion mobility spectrometry
Authors: Li Xiao , Cui Wenjia , Wang Wenliang , Wang Yueming , Gong Zhiqing , Xu Zhixiang
Published: August 2019

Pickled ginger is a popular traditional Chinese pickled food. Analysis of the volatile compounds in pickled ginger is critical for guiding production, achieving a high level of sensory quality, and maintaining a healthy diet. Ion mobility spectrometry (IMS) with gas chromatography (GC) offers a fast, sensitive, and efficient tool for detecting volatile compounds. Herein, the headspace GC‐IMS method was used to detect the volatile flavour compounds produced during the pickling of ginger. The ion mobility data were continuously processed using the principal component analysis (PCA) and fingerprint chart methods. Based on the analysis of fresh ginger, pickled ginger, and soy sauce, two main components accounted for 58% and 27% of the total variance. During pickling, the heptanal and heptanone contents decreased, while the contents of butanal, butanone, and methional increased, as determined from the GC‐IMS fingerprint, resulting in changes in the flavour of the pickled ginger. The GC‐IMS method was efficient, convenient, and useful for the detection of volatile flavour compounds produced during the ginger pickling process.
Development and optimization of processing techniques for intermediate moisture muskmelon chunks
Authors: Din Ahmad , Nadeem Muhammad , Saeed Farhan , Ahmad Muhammad Haseeb , Tufail Tabussam , Bader Ul Ain Huma , Mushtaq Zarina , Hussain Shahzad , Anjum Faqir Muhammad
Published: August 2019

Muskmelon (Cucumis melo) fruit is a best source of vitamins, minerals, and bioactive components. Ingestion of high sugary drinks leads to numerous ailments such as diabetes mellitus, obesity, and tooth decay. This study intended at formulation of intermediate moisture food with various combinations of sugar and glycerol and same levels of potassium metabisulphite, potassium sorbate, calcium chloride, and citric acid. It was observed a gradual decrease in TSS (56.53–53.28), vitamin C level in all treatments with the passage of time. The declining trend in ascorbic acid (25.49–21.63 mg/100 g) content of muskmelon chunks was increased as a function of storage. Sensory results showed that there was declining trend in the scores obtained for color parameter, that is, L* from 60.23 to 55.98. The overall results showed that combination of different additives contributed best values (T3) for flavor (7.70), taste (8.15), vitamin C (25.60 mg/100 g), and pH (5.16) as compared to other treatments. Conclusively, developed chunks of treatment 3 are physicochemical and organoleptically considered best, as it is helpful to sustain life stability of muskmelon and enhance its marketability.
Three‐field mixed finite element formulations for gradient elasticity at finite strains
Authors: Riesselmann Johannes , Ketteler Jonas Wilhelm , Schedensack Mira , Balzani Daniel
Published: August 2019

Gradient elasticity formulations have the advantage of avoiding geometry‐induced singularities and corresponding mesh dependent finite element solution as apparent in classical elasticity formulations. Moreover, through the gradient enrichment the modeling of a scale‐dependent constitutive behavior becomes possible. In order to remain C0 continuity, three‐field mixed formulations can be used. Since so far in the literature these only appear in the small strain framework, in this contribution formulations within the general finite strain hyperelastic setting are investigated. In addition to that, an investigation of the inf sup condition is conducted and unveils a lack of existence of a stable solution with respect to the L2‐H1‐setting of the continuous formulation independent of the constitutive model. To investigate this further, various discretizations are analyzed and tested in numerical experiments. For several approximation spaces, which at first glance seem to be natural choices, further stability issues are uncovered. For some discretizations however, numerical experiments in the finite strain setting show convergence to the correct solution despite the stability issues of the continuous formulation. This gives motivation for further investigation of this circumstance in future research. Supplementary numerical results unveil the ability to avoid singularities, which would appear with classical elasticity formulations.
Detection of CSF1 rearrangements deleting the 3′ UTR in tenosynovial giant cell tumors
Authors: Ho Julie , Peters Thomas , Dickson Brendan C. , Swanson David , Fernandez Anita , Frova‐Seguin Aurelie , Valentin Marie‐Anne , Schramm Ursula , Sultan Marc , Nielsen Torsten O. , Demicco Elizabeth G.
Published: August 2019

Tenosynovial giant cell tumors (TGCTs) are characterized by rearrangements of CSF1, thought to drive overexpression of macrophage colony‐stimulating factor (CSF1), thereby promoting tumor growth and recruitment of non‐neoplastic mononuclear and multinucleated inflammatory cells. While fusions to collagen promoters have been described, the mechanism of CSF1 overexpression has been unclear in a majority of cases. Two cohorts of TGCT were investigated for CSF1 rearrangements using fluorescence in situ hybridization (FISH) and either RNA‐seq or DNA‐seq with Sanger validation. The study comprised 39 patients, including 13 localized TGCT, 21 diffuse TGCT, and five of unspecified type. CSF1 rearrangements were identified by FISH in 30 cases: 13 translocations, 17 3′ deletions. Sequencing confirmed CSF1 breakpoints in 28 cases; in all 28 the breakpoint was found to be downstream of exon 5, replacing or deleting a long 3′ UTR containing known miRNA and AU‐rich element negative regulatory sequences. We also confirmed the presence of CBL exon 8‐9 mutations in six of 21 cases. In conclusion, TGCT in our large cohort were characterized by variable alterations, all of which led to truncation of the 3′ end of CSF1, instead of the COL6A3‐CSF1 fusions previously reported in some TGCTs. The diversity of fusion partners but consistent integrity of CSF1 functional domains encoded by exons 1‐5 support a hypothesis that CSF1 overexpression results from transcription of a truncated form of CSF1 lacking 3′ negative regulatory sequences. The presence of CBL mutations affecting the linker and RING finger domain suggests an alternative mechanism for increased CSF1/CSF1R signaling in some cases.
Transoral robotic thyroidectomy on two human cadavers using the Intuitive da Vinci single port robotic surgical system and CO2 insufflation: Preclinical feasibility study
Authors: Park Dawon , Shaear Mohammad , Chen Yu‐Hsien , Russell Jonathon O. , Kim Hoon Yub , Tufano Ralph P.
Published: August 2019

Background

Transoral vestibular approach endoscopic thyroidectomy has gained popularity worldwide because it avoids a cutaneous incision. Some surgeons have expressed reservations about operating with only 2 instruments in the endoscopic technique, and some therefore utilize an axillary incision as an adjunct to facilitate dissection. The Intuitive da Vinci single port robotic system offers the potential to overcome this limitation without an axillary incision.

Methods

In this study, the Intuitive da Vinci single port robotic surgical system was used to perform transoral thyroidectomy on 2 human cadavers.

Results

A total thyroidectomy was performed in 2 cadavers using the da Vinci single port (SP) robot via transoral vestibular technique. The dissections were performed with removal of the thyroid gland and preservation of the recurrent laryngeal nerves and parathyroid glands.

Conclusion

In our evaluation, transoral vestibular approach robotic thyroidectomy using the Intuitive da Vinci SP system facilitated dissection without the need for an axillary incision.