bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tuning the Gate‐Opening Pressure in a Switching pcu Coordination Network, X‐pcu‐5‐Zn, by Pillar‐Ligand Substitution
Authors: Zhu Ai‐Xin , Yang Qing‐Yuan , Mukherjee Soumya , Kumar Amrit , Deng Cheng‐Hua , Bezrukov Andrey A. , Shivanna Mohana , Zaworotko Michael J. 
Published: October 2019

AbstractCoordination networks that reversibly switch between closed and open phases are of topical interest since their stepped isotherms can offer higher working capacities for gas‐storage applications than the related rigid porous coordination networks. To be of practical utility, the pressures at which switching occurs, the gate‐opening and gate‐closing pressures, must lie between the storage and delivery pressures. Here we study the effect of linker substitution to fine‐tune gate‐opening and gate‐closing pressure. Specifically, three variants of a previously reported pcu‐topology MOF, X‐pcu‐5‐Zn, have been prepared: X‐pcu‐6‐Zn, 6=1,2‐bis(4‐pyridyl)ethane (bpe), X‐pcu‐7‐Zn, 7=1,2‐bis(4‐pyridyl)acetylene (bpa), and X‐pcu‐8‐Zn, 8=4,4′‐azopyridine (apy). Each exhibited switching isotherms but at different gate‐opening pressures. The N2, CO2, C2H2, and C2H4 adsorption isotherms consistently indicated that the most flexible dipyridyl organic linker, 6, afforded lower gate‐opening and gate‐closing pressures. This simple design principle enables a rational control of the switching behavior in adsorbent materials.
Hydrogen Bonding Between Ions of Like Charge in Ionic Liquids Characterized by NMR Deuteron Quadrupole Coupling Constants—Comparison with Salt Bridges and Molecular Systems
Authors: Khudozhitkov Alexander E. , Neumann Jan , Niemann Thomas , Zaitsau Dzmitry , Stange Peter , Paschek Dietmar , Stepanov Alexander G. , Kolokolov Daniil I. , Ludwig Ralf 
Published: October 2019

AbstractWe present deuteron quadrupole coupling constants (DQCC) for hydroxyl‐functionalized ionic liquids (ILs) in the crystalline or glassy states characterizing two types of hydrogen bonding: The regular Coulomb‐enhanced hydrogen bonds between cation and anion (c–a), and the unusual hydrogen bonds between cation and cation (c–c), which are present despite repulsive Coulomb forces. We measure these sensitive probes of hydrogen bonding by means of solid‐state NMR spectroscopy. The DQCCs of (c–a) ion pairs and (c–c) H‐bonds are compared to those of salt bridges in supramolecular complexes and those present in molecular liquids. At low temperatures, the (c–c) species successfully compete with the (c–a) ion pairs and dominate the cluster populations. Equilibrium constants obtained from molecular‐dynamics (MD) simulations show van't Hoff behavior with small transition enthalpies between the differently H‐bonded species. We show that cationic‐cluster formation prevents these ILs from crystallizing. With cooling, the (c–c) hydrogen bonds persist, resulting in supercooling and glass formation.
Evolved Aliphatic Halogenases Enable Regiocomplementary C−H Functionalization of a Pharmaceutically Relevant Compound
Authors: Hayashi Takahiro , Ligibel Mathieu , Sager Emine , Voss Moritz , Hunziker Jürg , Schroer Kirsten , Snajdrova Radka , Buller Rebecca 
Published: October 2019

AbstractNon‐heme iron halogenases are synthetically valuable biocatalysts that are capable of halogenating unactivated sp3‐hybridized carbon centers with high stereo‐ and regioselectivity. The reported substrate scope of these enzymes, however, is limited primarily to the natural substrates and their analogues. We engineered the halogenase WelO5* for chlorination of a martinelline‐derived fragment. Using structure‐guided evolution, a halogenase variant with a more than 290‐fold higher total turnover number and a 400‐fold higher apparent kcat compared to the wildtype enzyme was generated. Moreover, we identified key positions in the active site that allow direction of the halogen to different positions in the target substrate. This is the first example of enzyme engineering to expand the substrate scope of a non‐heme iron halogenase beyond the native indole‐alkaloid‐type substrates. The highly evolvable nature of WelO5* underscores the usefulness of this enzyme family for late‐stage halogenation.
Towards Reliable and Quantitative Surface‐Enhanced Raman Scattering (SERS): From Key Parameters to Good Analytical Practice
Authors: Bell Steven E. J. , Charron Gaëlle , Cortés Emiliano , Kneipp Janina , de la Chapelle Marc Lamy , Langer Judith , Procházka Marek , Tran Vi , Schlücker Sebastian 
Published: October 2019

AbstractExperimental results obtained in different laboratories world‐wide by researchers using surface‐enhanced Raman scattering (SERS) can differ significantly. We, an international team of scientists with long‐standing expertise in SERS, address this issue from our perspective by presenting considerations on reliable and quantitative SERS. The central idea of this joint effort is to highlight key parameters and pitfalls that are often encountered in the literature. To that end, we provide here a series of recommendations on: a) the characterization of solid and colloidal SERS substrates by correlative electron and optical microscopy and spectroscopy, b) on the determination of the SERS enhancement factor (EF), including suitable Raman reporter/probe molecules, and finally on c) good analytical practice. We hope that both newcomers and specialists will benefit from these recommendations to increase the inter‐laboratory comparability of experimental SERS results and further establish SERS as an analytical tool.
Electronic Tuning of Mixed Quinoidal‐Aromatic Conjugated Polyelectrolytes: Direct Ionic Substitution on Polymer Main‐Chains
Authors: Anderson Christopher L. , Dai Nan , Teat Simon J. , He Bo , Wang Shu , Liu Yi 
Published: October 2019

AbstractThe synthesis of conjugated polymers with ionic substituents directly bound to their main chain repeat units is a strategy for generating strongly electron‐accepting conjugated polyelectrolytes, as demonstrated through the synthesis of a series of ionic azaquinodimethane (iAQM) compounds. The introduction of cationic substituents onto the quinoidal para‐azaquinodimethane (AQM) core gives rise to a strongly electron‐accepting building block, which can be employed in the synthesis of ionic small molecules and conjugated polyelectrolytes (CPEs). Electrochemical measurements alongside theoretical calculations indicate notably low‐lying LUMO values for the iAQMs. The optical band gaps measured for these compounds are highly tunable based on structure, ranging from 2.30 eV in small molecules down to 1.22 eV in polymers. The iAQM small molecules and CPEs showcase the band gap reduction effects of combining the donor‐acceptor strategy with the bond‐length alternation reduction strategy. As a demonstration of their utility, the iAQM CPEs so generated were used as active agents in photothermal therapy.
Detection and Chiral Recognition of α‐Hydroxyl Acid through 1H and CEST NMR Spectroscopy Using a Ytterbium Macrocyclic Complex
Authors: He Haonan , Zhao Kelu , Xiao Long , Zhang Yi , Cheng Yi , Wan Sikang , Chen Shizhen , Zhang Lei , Zhou Xin , Liu Kai , Zhang Hongjie 
Published: October 2019

AbstractChiral α‐hydroxyl acids are of great importance in chemical synthesis. Current methods for recognizing their chirality by 1H NMR are limited by their small chemical shift differences and intrinsic solubility problem in organic solvents. Herein, we developed three YbDO3A(ala)3 derivatives to recognize four different commercially available chiral α‐hydroxyl acids in aqueous solution through 1H NMR and chemical exchange saturation transfer (CEST) spectroscopy. The shift difference between chiral α‐hydroxyl acid observed by proton and CEST NMR ranged from 15–40 and 20–40 ppm, respectively. Our work demonstrates for first time, that even one chiral center on the side‐arm chain of cyclen could set the stage for rotation of the other two non‐chiral side chains into a preferred position. This is ascribed to the lower energy state of the structure. The results show that chiral YbDO3A‐like complexes can be used to discriminate chiral α‐hydroxyl acids with a distinct signal difference.
Synthesis and Application of Monomeric Chalcogenolates of 13 Group Elements
Authors: Řičica Tomáš , Milasheuskaya Yaraslava , Růžičková Zdeňka , Němec Petr , Švanda Pavel , Zmrhalová Zuzana Olmrová , Jambor Roman , Bouška Marek 
Published: October 2019

AbstractUtilization of the N,C,N‐chelating ligand L (L={2,6‐(Me2NCH2)2C6H3}−) in the chemistry of 13 group elements provided either N→In coordinated monomeric chalcogenides LIn(μ‐E4) (E=S, Se) with unprecedented InE4 inorganic ring or monomeric chalcogenolates LM(EPh)2 (M=Ga, In). Complex LGa(SePh)2 was selected as the most suitable single source precursor (SSP) for the deposition of amorphous semiconducting GaSe thin films using spin coating method.
Enhanced production of d‐psicose 3‐epimerase in Bacillus subtilis by regulation of segmented fermentation
Authors: Fu Gang , Zhang Shibin , Dong Huina , Chen Jingqi , Tu Ran , Zhang Dawei 
Published: October 2019

Abstractd‐Psicose 3‐epimerase is an enzyme that catalyzes the synthesis of d‐psicose from d‐fructose. We cloned the d‐psicose 3‐epimerase from Ruminococcus sp. (RDPE) and expressed it in Bacillus subtilis A311. By a two‐step pH regulation of segmented fermentation, we significantly improved the RDPE production and decreased the fermentation cost. The two‐step regulation consisted of the first step maintained the pH value at 7.0 for 24 H and the second step adjusted the pH value up to 7.5 slowly for another 24 H. Finally, the RDPE production was increased to 74 U/mL, which was about 2.5‐fold compared with the control. Our segmented fermentation strategy provides an important experimental basis for the industrial‐scale production of RDPE.
Cycle of violence in women victims of domestic violence: Qualitative analysis of OPD 2 interview
Authors: Both Luciane Maria , Favaretto Taís Cristina , Freitas Lúcia Helena Machado 
Published: October 2019

AbstractIntroductionDomestic violence places woman as the victim and man as the aggressor in the family environment. There is limited consistent and clear information based on empirical evidence on the dynamic functioning of the victims.ObjectiveTo further understand the psychodynamics of women in the cycle of violence taking into account the aspects of psychological trauma. It is transversal research design. The sample was composed of ten women victim of domestic violence. Data collection was based on the OPD‐2 Clinical Interview. Content analysis was performed from categories created by a posteriori: (a) Previous history; (b) Behavioral aspects; (c) Emotional aspects; (d) Reason for being in the relationship; (e) Type of violence and explanation for the reason of violence; (f) Support network and daily activities; and (g) Clinical and legal referral.ResultsConstant violence causes changes in the structural functioning and psychological conflict of the victims: difficulties in mentalization, instability in relationships, emotional dependence, abandonment of her own life for her partners, difficulty in having a sense of identity. Victims presented difficulties in making significant changes in daily life to break the cycle of violence.ConclusionThe research sought to collaborate with more evidence on the subject, suggesting a reformulation on forms of encounter to break the cycle of violence.
Neuronal antibodies in adult patients with new‐onset seizures: A prospective study
Authors: Zelano Johan , Axelsson Markus , Constantinescu Radu , Malmeström Clas , Kumlien Eva 
Published: October 2019

AbstractObjectivesImmunotherapy in addition to antiepileptic drugs can improve seizure freedom rates in autoimmune epilepsy, highlighting the importance of early diagnosis. A diagnosis of autoimmune epilepsy can be supported by presence of serum antibodies to neuronal antigens. We asked how often neuronal antibodies are found in the serum of unselected adult patients with new‐onset seizures and whether such testing could improve detection of autoimmune epilepsy.Material and MethodsWe included 44 patients over the age of 25 presenting after at least one unprovoked seizure to the Neurology Clinic at Sahlgrenska University Hospital, Gothenburg, Sweden. The median time between the first‐ever seizure in life and the serum sampling was 50 days (range 22–11,000). Antibody testing in serum was performed according to the manufacturer's instructions. The patients were followed for at least 1 year.ResultsEpilepsy could be diagnosed already at the first visit in 21/44 patients (47.7%). Two patients (4.5%) were positive for neuronal antibodies: one against contactin‐associated protein 2 (CASPR‐2) and one against glutamate acid decarboxylase (GAD). Three patients (6.7%) displayed very weak immunoreactivity that was deemed clinically insignificant. One of the antibody‐positive patients had only a single seizure. The other had a focal cortical dysplasia and was seizure‐free on levetiracetam. None of the five patients with antibodies or immunoreactivity displayed any feature of autoimmune epilepsy.ConclusionsWe conclude that indiscriminate testing in patients presenting to a first seizure clinic with new‐onset seizures or epilepsy is unlikely to improve detection of autoimmune epilepsy.
Beta‐blockers exert potent anti‐tumor effects in cutaneous and uveal melanoma
Authors: Bustamante Prisca , Miyamoto Denise , Goyeneche Alicia , de Alba Graue Paulina García , Jin Eva , Tsering Thupten , Dias Ana Beatriz , Burnier Miguel N. , Burnier Julia V. 
Published: October 2019

AbstractBackgroundMelanoma is a life‐threatening group of cancers mainly affecting the skin (cutaneous melanoma, CM) and the eyes (uveal melanoma, UM). Nearly half of patients with UM develop liver metastases regardless of the primary treatment. For this reason, adjuvant therapy to prevent disease progression is essential to improve survival of patients with melanoma. Beta‐adrenoceptors (β‐AR) have emerged as novel targets to inhibit tumor growth and dissemination in CM, but have not been investigated in UM.MethodsThe aim of this study was to comprehensively evaluate the effects of a non‐selective β‐blocker in UM and CM. Propranolol was tested on four UM and two CM cell lines to determine the effects of this beta‐blocker. The expression of β‐AR in UM was assessed in enucleated eyes of 36 patients.ResultsThe results showed that propranolol exerts potent anti‐proliferative effects, attenuates migration, reduces VEGF and induces cell cycle arrest and apoptosis in both UM and CM in a dose‐dependent manner. Furthermore, levels of cell‐free DNA released from the cells correlated to propranolol treatment and may be an indicator of treatment response. Finally, immunohistochemical analysis revealed the expression of β1 and β2 adrenoceptors in all UM patients, with higher expression seen in the more aggressive epithelioid versus less aggressive spindle cells.ConclusionsCollectively our data suggest that a nonselective beta‐blocker may be effective against melanoma. For the first time, we show potent anti‐tumor effects in UM cells following propranolol administration and expression of β1 and β2 adrenoceptors in patient tissue.
Population‐based study evaluating and predicting the probability of death resulting from thyroid cancer among patients with papillary thyroid microcarcinoma
Authors: Wang Kun , Xu Jing , Li Shuyu , Liu Shiyang , Zhang Lin 
Published: October 2019

AbstractBackgroundPapillary thyroid microcarcinoma (PTMC) is an indolent carcinoma. The cumulative incidence of death from patients with PTMC and the nomogram built based on the competing risks model have not been described.MethodsPatients diagnosed with PTMC were selected from the Surveillance, Epidemiology, and End Results (SEER) program (1983‐2015). Cumulative incidence function was utilized to calculate the likelihood of death resulting from thyroid cancer. Gray's test was conducted to examine the difference in the cumulative incidence of death between groups. A proportional subdistribution hazard model was constructed and we further built a nomogram to quantify the likelihood of death using the model. A 10‐fold cross‐validation procedure was adopted to validate the model.ResultsA total of 46 662 patients diagnosed with PTMC were included. The median follow‐up time was 81 months (range, 1 to 407 months). The 5‐year, 10‐year, and 20‐year probabilities of death from thyroid carcinoma were 0.3%, 0.6%, and 1.4%, respectively. The age at diagnosis, sex, tumor extension, and lymph node involvement were related to the cumulative incidence of death. A proportional subdistribution hazard model was developed. The performance of the model was good. A nomogram was built based on the model to predict the likelihood of death in patients with PTMC.ConclusionThe survival rate of patients with PTMC is excellent. The nomogram constructed based on the well‐performed competing risks model is helpful for both patients and clinicians.
Lower common pathway location detected by cryoablation of atrioventricular nodal reentrant tachycardia of the common variety
Authors: Okishige Kaoru , Shigeta Takatoshi , Nakamura Rena A. , Hirao Tatsuhiko , Yoshida Hiroshi , Yamauchi Yasuteru 
Published: October 2019

AbstractAs different from radiofrequency current energy, cryofreezing energy is able to provide reversible effects on cardiac tissue, called “cryomapping,” which enables us to predict the effects of a subsequent application of ablative energy. Cryomapping is able to delineate the anatomical location of the lower common pathway of atrioventricular nodal reentrant tachycardia.
Penile Mondor’s disease: Clinical and sonographic images
Authors: Mukendi Alain Mwamba , Mahlobo Florence 
Published: October 2019

AbstractPenile Mondor's disease or thrombophlebitis of the superficial dorsal penile vein is a rare disorder of the penis. Reported cases in the literature are mostly focal thrombus. We present clinical and sonographic images of an extensive superficial dorsal penile vein thrombosis.
Monitoring and Mitigation of Methane Emissions from Pressure Relief Valves of a Biogas Plant
Authors: Reinelt Torsten , Liebetrau Jan 
Published: October 2019

AbstractThe two‐year monitoring (732 days) of operational methane emissions from pressure relief valves of the gasholders from an agriculture biogas plant is presented. The monitoring aimed at the identification of major factors influencing the emissions and the effect of mitigation measures deduced from the results. The determined emission factors from the valves of both gastight covered digesters are 1.8 and 0.6 % CH4 loss for the first and second year of investigation, respectively. The emission rates strongly depend on seasonal factors like (fast) changes in ambient air temperature as well as the capacity utilization of the combined heat and power and the operation of the gasholders. The implemented mitigation measures significantly reduced the measured methane emissions in the second year of the investigation.
Unveiling Lithium Roles in Cobalt‐Free Cathodes for Efficient Oxygen Reduction Reaction below 600 °C
Authors: Rehman Ateeq Ur , Li Mengran , Knibbe Ruth , Khan M. Shirjeel , Zhou Wei , Zhu Zhonghua 
Published: October 2019

AbstractImproving the sluggish electrocatalytic oxygen reduction reaction (ORR) over cobalt‐free cathodes at 550–800 °C is imperative to circumvent challenges faced by practical operation of intermediate temperature solid oxide fuel cells. In this work, we synthesize novel cobalt‐free, lithium (Li)‐doped, perovskite oxides Sr1‐xLixFe0.8Nb0.1Ta0.1O3‐δ (SLFNTx, x=0–0.1) as cathodes for efficient ORR catalysis. When the Li concentration is less than 0.05, ORR activity is enhanced by over 1.6‐fold in comparison to the undoped SFNT below 600 °C in both symmetrical and anode‐supported single cells configurations. Our comprehensive investigation over crystal structure, surface, and mixed conductivities revealed that a moderate concentration (<0.05) of Li could bestow the perovskite with a stable cubic perovskite structure that contains an optimal concentration of oxygen vacancies and A‐site deficiencies. Such trend originates from the lower electronegativity and smaller size of Li dopant than the strontium host. The lower electronegativity increases oxygen vacancies. The small Li dopant induces thermal‐migration of Li species and creates A‐site deficiency. These insights highlight an effective strategy to advance the performance of cobalt‐free ORR electrocatalyst below 600 °C through in situ thermal surface migration of the A‐site cations.
Demanding energy from carbon
Authors: Yuan Yifei , Lu Jun 
Published: October 2019

AbstractCarbon is the central element driving the evolution of our human society towards prosperity over several historical stages. As for now, we are in a stage of blossoming sciences and technologies related to carbon materials, as a result of which our ever‐growing energy demand has been largely satisfied. Yet, the expected rise of carbon energy consumption and the emerging environmental concerns have prevented us from being optimistic. To build a sufficiently powered future, we have been revolutionizing our ways of carbon energy utilization by discovering and designing new carbon structures, exploring and enhancing their unique physicochemical properties, and pursuing environmentally friendly strategies. Emerging structures such as graphene and sp‐bonded C18 have allowed us to discover carbon's promising properties such as energy storage and superconductivity, while green energy solutions such as fuel cells and CO2 reduction are working synergistically to purify the ecospheric carbon cycle. Therefore, this essay timely discusses related carbon sciences and technologies that have been the milestones shaping our energy consumption, based on which our energy future can be envisioned to be green and prosperous.
Bequest expectations among the U.S. older adults: The roles of generational differences and personality traits
Authors: Fan Lu , Chatterjee Swarn 
Published: October 2019

AbstractThis study used the 2012 and 2014 panels of the Health and Retirement Study, a nationally representative dataset, to examine the associations between personality traits, generational cohorts, and bequest expectations among elderly households in the United States. The results indicated that neuroticism was associated with a lower subjective probability of leaving a bequest, and extroversion was associated with a higher subjective probability of leaving a bequest. Income, assets, and educational attainment were also positively associated with self‐reported bequest expectations. Generational differences were observed in the subjective probabilities of leaving bequests. The results of this study help in understanding the psychosocial factors associated with leaving bequests in an aging society, and provide implications for financial planners, practitioners, and policy makers.