bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystals in Minutes: Instant On‐Site Microcrystallisation of Various Flavours of the CYP102A1 (P450BM3) Haem Domain
Authors: Stanfield Joshua Kyle , Omura Keita , Matsumoto Ayaka , Kasai Chie , Sugimoto Hiroshi , Shiro Yoshitsugu , Watanabe Yoshihito , Shoji Osami 
Published: March 2020

AbstractDespite CYP102A1 (P450BM3) representing one of the most extensively researched metalloenzymes, crystallisation of its haem domain upon modification can be a challenge. Crystal structures are indispensable for the efficient structure‐based design of P450BM3 as a biocatalyst. The abietane diterpenoid derivative N‐abietoyl‐l‐tryptophan (AbiATrp) is an outstanding crystallisation accelerator for the wild‐type P450BM3 haem domain, with visible crystals forming within 2 hours and diffracting to a near‐atomic resolution of 1.22 Å. Using these crystals as seeds in a cross‐microseeding approach, an assortment of P450BM3 haem domain crystal structures, containing previously uncrystallisable decoy molecules and diverse artificial metalloporphyrins binding various ligand molecules, as well as heavily tagged haem‐domain variants, could be determined. Some of the structures reported herein could be used as models of different stages of the P450BM3 catalytic cycle.
Enantioselective Synthesis of N–C Axially Chiral Compounds by Cu‐Catalyzed Atroposelective Aryl Amination
Authors: Frey Johanna , Malekafzali Alaleh , Delso Isabel , Choppin Sabine , Colobert Françoise , Wencel‐Delord Joanna 
Published: March 2020

AbstractN−C axially chiral compounds have emerged recently as appealing motifs for drug design. However, the enantioselective synthesis of such molecules is still poorly developed and surprisingly no metal‐catalyzed atroposelective N‐arylations have been described. Herein, we disclose an unprecedented Cu‐catalyzed atroposelective N−C coupling that proceeds at room temperature. Such mild reaction conditions, which are a crucial parameter for atropostability of the newly generated products, are operative thanks to the use of hypervalent iodine reagents as a highly reactive coupling partners. A large panel of the N−C axially chiral compounds was afforded with very high enantioselectivity (up to >99 % ee) and good yields (up to 76 %). Post‐modifications of thus accessed atropisomeric compounds allows further expansion of the diversity of these appealing compounds.
Observation of Ion Electrosorption in Metal–Organic Framework Micropores with In Operando Small‐Angle Neutron Scattering
Authors: He Lilin , Yang Luming , Dincă Mircea , Zhang Rui , Li Jianlin 
Published: March 2020

AbstractA molecular‐level understanding of transport and adsorption mechanisms of electrolyte ions in nanoporous electrodes under applied potentials is essential to control the performance of double‐layer capacitors. Here, in operando small‐angle neutron scattering (SANS) is used to directly detect ion movements into the nanopores of a conductive metal–organic framework (MOF) electrode under operating conditions. Neutron‐scattering data reveals that most of the void space within the MOF is accessible to the solvent. Upon the addition of the electrolyte sodium triflate (NaOTf), the ions are adsorbed on the outer surface of the protrusions to form a 30 Å layer instead of entering the ionophobic pores in the absence of an applied charging potential. The changes in scattering intensity when potentials are applied suggests the ion rearrangement in the micropores following different mechanisms depending on the electrode polarization. These observations shed insights on ion electrosorption in electrode materials.
Strong and Confined Acids Control Five Stereogenic Centers in Catalytic Asymmetric Diels–Alder Reactions of Cyclohexadienones with Cyclopentadiene
Authors: Ghosh Santanu , Das Sayantani , De Chandra Kanta , Yepes Diana , Neese Frank , Bistoni Giovanni , Leutzsch Markus , List Benjamin 
Published: March 2020

AbstractWe describe a highly enantioselective Diels–Alder reaction of cross‐conjugated cyclohexadienones with cyclopentadiene, in which five stereocenters are effectively controlled by a strongly acidic and confined imidodiphosphorimidate catalyst. Our approach provides tricyclic products in excellent stereoselectivity. We also report methods to convert the obtained products into useful intermediates and a computational study that aids in gaining deeper insight into the reaction mechanism and origin of stereoselectivity.
Enantiocomplementary Epoxidation Reactions Catalyzed by an Engineered Cofactor‐Independent Non‐natural Peroxygenase
Authors: Xu Guangcai , Crotti Michele , Saravanan Thangavelu , Kataja Kim M. , Poelarends Gerrit J. 
Published: March 2020

AbstractPeroxygenases are heme‐dependent enzymes that use peroxide‐borne oxygen to catalyze a wide range of oxyfunctionalization reactions. Herein, we report the engineering of an unusual cofactor‐independent peroxygenase based on a promiscuous tautomerase that accepts different hydroperoxides (t‐BuOOH and H2O2) to accomplish enantiocomplementary epoxidations of various α,β‐unsaturated aldehydes (citral and substituted cinnamaldehydes), providing access to both enantiomers of the corresponding α,β‐epoxy‐aldehydes. High conversions (up to 98 %), high enantioselectivity (up to 98 % ee), and good product yields (50–80 %) were achieved. The reactions likely proceed via a reactive enzyme‐bound iminium ion intermediate, allowing tweaking of the enzyme's activity and selectivity by protein engineering. Our results underscore the potential of catalytic promiscuity for the engineering of new cofactor‐independent oxidative enzymes.
Creation of Al‐Enriched Mesoporous ZSM‐5 Nanoboxes with High Catalytic Activity: Converting Tetrahedral Extra‐Framework Al into Framework Sites by Post Treatment
Authors: Jiao Yilai , Forster Luke , Xu Shaojun , Chen Huanhao , Han Jingfeng , Liu Xuqing , Zhou Yangtao , Liu Jinmin , Zhang Jinsong , Yu Jihong , D'Agostino Carmine , Fan Xiaolei 
Published: March 2020

AbstractZSM‐5 zeolite nanoboxes with accessible meso‐micro‐pore architecture and strong acid sites are important in relevant heterogeneous catalysis suffering from mass transfer limitations and weak acidities. Rational design of parent zeolites with concentrated and non‐protective coordination of Al species can facilitate post‐synthetic treatment to produce mesoporous ZSM‐5 nanoboxes. In this work, a simple and effective method was developed to convert parent MFI zeolites with tetrahedral extra‐framework Al into Al‐enriched mesoporous ZSM‐5 nanoboxes with low silicon‐to‐aluminium ratios of ≈16. The parent MFI zeolite was prepared by rapid ageing of the zeolite sol gel synthesis mixture. The accessibility to the meso‐micro‐porous intra‐crystalline network was probed systematically by comparative pulsed field gradient nuclear magnetic resonance diffusion measurements, which, together with the strong acidity of nanoboxes, provided superb catalytic activity and longevity in hydrocarbon cracking for propylene production.
Ammonium ion removal using activated zeolite and chitosan
Authors: Safie Nurliyana Nasuha , Zahrim Yaser Abu , Hilal Nidal 
Published: March 2020

AbstractStudies have previously been done on efficacies of chitosan and zeolite in ammonium ion (NH4+) removal. However, no study compares the adsorption performance of natural zeolite (NZ) and activated NZ (ANZ) with high molecular weight chitosan (HMWC) and low molecular weight chitosan (LMWC). Hence, this study investigates the potentials of NZ, ANZ, LMWC, and HMWC in NH4+ removal. The characteristics of NZ, ANZ, LMWC, and HMWC such as functional groups, surface morphology, elemental composition, zeta potential, and particle size was also investigated. The deposition of NH4+ on the surface of NZ and ANZ was confirmed with the absence of nitrogen by the adsorption spectrum of energy dispersive X‐ray (EDX) and supported by the presence of an Fourier transform infrared (FTIR) stretching band at ~3,500–3,300 cm−1, as well as broader and less intense bands ~1,600 cm−1 after the adsorption for all the adsorbents. The particle size of LMWC, HMWC, NZ, and ANZ were 98, 813, 22,354, and 9,826 nm, respectively. Meanwhile, after the activation process, the composition of O, Si, Al, Fe, Ca, and Na was reduced. NH4+ batch adsorption was also studied. HMWC, NZ, and ANZ reached adsorption equilibrium at 15 h, meanwhile for LMWC, the equilibrium reached at t = 20 h. The adsorption capacity of LMWC, HMWC, NZ, and ANZ at an initial concentration of 50 mg/L was 0.769, 0.331, 2.162, and 2.937 mg/g, respectively.
Preparation and properties of polybutylene‐terephthalate/graphene oxide in situ flame‐retardant material
Authors: Li Zhengqiu , Li Wen , Liao Li , Li Jianbin , Wu Ting , Ran Longchang , Zhao Tianbao , Chen Baoshu 
Published: March 2020

AbstractIn this manuscript, an in situ layered intumescent flame retardant (IFR) of graphene oxide (GO) was used to produce a polybutylene terephthalate (PBT) flame‐retardant material with different flame‐retardant concentration gradients. IFR was introduced into the GO layered structure via a chemical reaction to achieve an in situ flame‐retardant effect. The elements of the composite were characterized using energy dispersive spectroscopy. The results showed that although the subsequent PBT‐based flame‐retardant composites displayed low flame‐retardant content, it exhibited excellent flame retardancy and mechanical properties. Due to the introduction of GO, the flame retardancy of the composites was improved significantly. The lamellar structure of GO provided a barrier allowing it to absorb condensed nucleus compounds. Therefore, continuous and compact scaly carbon layers were formed in the matrix during the burning process.
Synthesis of isocyanurate‐based imidazole carboxylate as thermal latent curing accelerator for thermosetting epoxy resins
Authors: Sun Xin , Wang Yiming , Tang Yuyao , Zhang Bowen , Wei Wei , Li Xiaojie , Fei Xiaoma , Liu Xiaoya 
Published: March 2020

AbstractA novel thermal latent curing accelerator, 1‐(2‐cyanoethyl)‐2‐methylimidazole/tris (2‐carboxyethyl) isocyanurate adduct (2MICN‐T), was successfully synthesized through an acid–base neutralization of tris(2‐carboxyethyl)isocyanurate (TCEIC) and 1‐(2‐cyanoethyl)‐2‐methylimidazole (2MICN). It was further added into diglycidylether of bisphenol A based epoxy resin/methylhexahydrophthalic anhydride mixture to form one‐component curing systems. With the addition of 2 wt% of 2MICN‐T, the one‐component system could be steadily stored for more than 1 month at room temperature, while the shelf life of 2MICN curing system was only 2 days. Nonisothermal differential scanning calorimeter also demonstrated the excellent thermal latency of 2MICN‐T in low‐temperature region and rapid initiation of the curing reaction when raising temperature. Compared to the cured resins with original 2MICN as accelerator, the resulted thermosets exhibited enhanced glassy storage modulus, glass transition temperature, and thermal stability when 2 wt% of 2MICN‐T was applied. It was attributed to the chemical incorporation of the isocyanurate moieties with multi carboxyl groups and nitrogen‐contained heterocyclic ring, effectively increasing the crosslinking density, chain rigidity, and heat resistance of the cured resin. Thus, it is suggested that 2MICN‐T can play both roles as latent curing accelerator and modifier for one‐component epoxy compounds, and is particularly recommended for application in electronic packaging fields.
Synthesis and docking study of benzimidazole–triazolothiadiazine hybrids as aromatase inhibitors
Authors: Acar Çevik Ulviye , Sağlık Begüm N. , Osmaniye Derya , Levent Serkan , Kaya Çavuşoğlu Betül , Karaduman Abdullah B. , Özkay Yusuf , Kaplancıklı Zafer A. 
Published: March 2020

AbstractAromatase is involved in the biosynthesis of estrogen and thus is a critical target for breast cancer. In this study, to identify new aromatase enzyme inhibitors, seven 3‐[4‐(5‐methyl‐1H‐benzo[d]imidazol‐2‐yl)phenyl]‐6‐(substituted phenyl)‐7H‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazine derivatives were synthesized. First, a 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay was performed to determine the inhibitory activity of the synthesized compounds on the MCF‐7 cell line. The aromatase inhibitory activity was determined for the active compounds 5b, 5c, 5e, and 5g on the MCF‐7 cell line. Compound 5g showed significant aromatase inhibitory activity (IC50 = 0.037 ± 0.001 µM). Interestingly, this compound, which bears a difluoro substituent at positions 2 and 4 of the phenyl ring, displayed the most potent aromatase inhibitory activity without significant cytotoxicity to a normal healthy cell line (NIH3T3). Furthermore, the interactions between the best active compounds and the active site of the enzyme were analyzed through a docking study. The results of this study determined that benzimidazole–triazolothiadiazine derivatives are promising compounds that should be further developed as a novel class of aromatase inhibitors.
Creating sites of community education and democracy: Henry Morris and the Cambridgeshire village colleges. A reflection 90 years on from their inception
Authors: Hopkins Neil 
Published: March 2020

This article investigates the work of Henry Morris (1889–1961), in particular his ideas on the Cambridgeshire village colleges. It is now 90 years since the first of these was founded in Sawston in 1930, and the article aims to address the issue of whether Morris’s views on education and democracy encapsulated in the village colleges still have relevancy in the early twenty‐first century. An overview of Morris’s career and the creation of the village colleges is investigated, using the work of Paul Hirst and associative democracy as a theoretical lens. It is argued that the Cambridgeshire village colleges do have some attributes of associative democracy, particularly their original emphasis as sites of local democracy and participation from voluntary bodies and private individuals. However, Morris’s role as Cambridgeshire’s Chief Education Officer (1922–1954) meant that the local state (in the guise of the County Council) played a more significant role in the village colleges than Hirst advocates for his version of associative democracy. As English primary and secondary schools turn from local authority control to academy status, Morris’s vision for local schools of and for local people is becoming increasingly compromised. The article ends with the work of Allen and Gann, both influenced by Morris, who argue for a revitalised form of comprehensive schooling and lifelong learning that again sees educational institutions as sites of grassroots democracy.
Beyond heuristics: CFD‐based novel multiparameter scale‐up for geometrically disparate bioreactors demonstrated at industrial 2kL–10kL scales
Authors: Scully James , Considine Laura B. , Smith Mark T. , McAlea Eamonn , Jones Nephi , O'Connell Edel , Madsen Emilee , Power Martin , Mellors Philip , Crowley John , O'Leary Niall , Carver Scott , Van Plew Daniel 
Published: March 2020

AbstractThe timely delivery of the most up‐to‐date medicines and drug products is essential for patients throughout the world. Successful scaling of the bioreactors used within the biopharmaceutical industry plays a large part in the quality and time to market of these products. Scale and topology differences between vessels add a large degree of complication and uncertainty within the scaling process. Currently, this approach is primarily achieved through extensive experimentation and facile empirical correlations, which can be costly and time consuming while providing limited information. The work undertaken in the current study demonstrates a more robust and complete approach using computational fluid dynamics (CFD) to provide potent multiparameter scalability, which only requires geometric and material properties before a comprehensive and detailed solution can be generated. The CFD model output parameters that can be applied in the scale‐up include mass transfer rates, mixing times, shear rates, gas hold‐up values, and bubble residence times. The authors examined three bioreactors with variable geometries and were able to validate them based on single‐phase and multiphase experiments. Furthermore, leveraging the resulting CFD output information enabled the authors to successfully scale‐up from a known 2kL to a novel and disparate 5kL single‐use bioreactor in the first attempted cell culture. This multiparameter scaling approach promises to ultimately lead to a reduction in the time to market providing patients with earlier access to the most groundbreaking medicines.
Mechanism of the oxidative stress‐mediated increase in lipid accumulation by the bacterium, R. opacus PD630: Experimental analysis and genome‐scale metabolic modeling
Authors: Sundararaghavan Archanaa , Mukherjee Amitava , Sahoo Swagatika , Suraishkumar G. K. 
Published: March 2020

AbstractAppropriate species of oleaginous bacteria, with their high growth rates and lipid accumulation capabilities, can be good contenders for industrial triacylglycerol (TAG) production, compared to microalgae. Further, oxidative stress (OS) can be used to significantly increase TAG yields in oleaginous microbes, but the mechanism is unexplored. In a first, this study explored the mechanism behind OS‐mediated increase in TAG accumulation by the bacterium, Rhodococccus opacus PD630, through experimental analysis and metabolic modelling. Two mechanisms that could increase acetyl‐CoA (TAG‐precursor) levels were hypothesized based on literature information. One was OS‐mediated inactivation of the aconitase (TCA cycle), and another was the inactivation of the triosephosphate isomerase (TPI; glycolysis). The results negated the involvement of aconitase in increased acetyl‐CoA levels. Analysis of the metabolic model showed that inactivation of TPI, re‐routed the flux through the pentose phosphate pathway (PPP), supplying both NADPH and acetyl‐CoA for TAG synthesis. Additionally, inactivation of TPI increased TAG flux by 143%, whereas, inactivating both TPI and aconitase, increased it by 152%. We present experimental evidence for OS‐mediated decrease in TPI activity and increase in activity of glucose‐6‐phosphate dehydrogenase (PPP enzyme). The findings indicate that increased flux through PPP can be explored to improve TAG accumulation on a large‐scale.
Choose to fly higher rather than pacing around
Authors: Musumeci Giuseppe , Aranzulla Tiziana Claudia 
Published: March 2020

Key Points
Pre‐existing right bundle branch block and the depth of the prosthesis in the left ventricle are predictors of permanent pacemaker implantation (PPI) following transcatheter aortic valve replacement.
The recapturable capability of the Evolut R system allows higher and more precise valve implantation and this was associated with halved incidence of PPI as compared with the CoreValve.
Larger studies are needed to assess the feasibility of systematic very high implantation (depth in the left ventricle outflow tract ≤3 mm) of the Evolut R and the associated rate of PPI.
BATMAN—Savior or vigilante?
Authors: Khan Jaffar M. , Lederman Robert J. 
Published: March 2020

Key Points
BATMAN is a new technique to prevent left ventricular outflow tract (LVOT) obstruction from transcatheter mitral valve replacement (TMVR) by deploying the transcatheter heart valve from the apex through a perforation of the anterior mitral valve leaflet.
The risks of uncontrolled balloon dilatation of the anterior mitral valve leaflet include extension of the tear superiorly into the aorto‐mitral curtain or laterally to avulse the trigone from the annulus.
Percutaneous laceration of the anterior mitral leaflet, pre‐emptive alcohol septal ablation, and transatrial leaflet resection are alternative strategies that prevent LVOT obstruction from TMVR
Combined alcohol septal ablation and transcatheter aortic valve replacement: Drunk and playing with fire
Authors: Rowin Ethan J. , Kimmelstiel Carey 
Published: March 2020

Key Points
Evaluation of the severity of aortic stenosis in the presence of dynamic left ventricular outflow (LVOT) obstruction is challenging.
Invasive hemodynamic assessment with provocative maneuvers can be useful to differentiate of the relative components of obstruction.
In patients with both dynamic LVOT obstruction and aortic stenosis, surgical myectomy and concurrent surgical aortic valve replacement is the optimal treatment strategy; combined alcohol septal ablation and transcatheter aortic valve replacement should only be considered for very high surgical risk patients.
Effects of different cultivars and particle sizes of non‐degermed millet flour fractions on the physical and texture properties of Chinese steamed bread
Authors: Li Shao‐Hui , Zhao Wei , Li Peng‐Liang , Min Guang , Zhang Ai‐Xia , Zhang Jia‐Li , Liu Ying‐Ying , Liu Jing‐Ke 
Published: March 2020

AbstractBackground and objectivesWe studied the effects of different cultivars of non‐degermed millet flour fraction and the particle size on Chinese steamed bread to promote the industrial development of the whole‐grain food industry.FindingsWe used a texture analyzer to analyze the changes introduced by different cultivars of non‐degermed millet flour fraction, and the effect of its particle size on the hardness, adhesiveness, springiness, gumminess, and chewiness parameters, based on the analysis of height‐to‐diameter ratio and specific volume. We obtained samples of different particle size fractions by using 40, 60, 80, 100, 120, and 140 mesh sieves and determined that the particle substitution of non‐degermed millet flour fraction was at a level of 30%. We conducted partial least squares discriminant analysis (PLS‐DA) screening to identify the signature differences of quality components.ConclusionsAccording to Hunter Laboratory values (whiteness/darkness, L*; redness/greenness, a*; and yellowness/blueness, b*), the results indicated that as the particle size decreased, the L* and whiteness index (W) values decreased but the a* and b* values increased, and the hardness, cohesiveness, adhesiveness, springiness, gumminess, and chewiness parameters of Chinese steamed bread with different particle sizes were significantly different (p < .05).Significance and noveltyPartial least squares discriminant analysis could distinguish japonica cultivar samples and glutinous cultivar samples. According to the variable influence on projection (VIP) values, we screened chewiness, gumminess, and hardness as the signature differences of the quality components.