bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and Efficient Postsynthetic DNA Labeling in Cells by Means of Strain‐Promoted Sydnone‐Alkyne Cycloadditions
Authors: Krell Katja , Pfeuffer Bastian , Rönicke Franziska , Chinoy Zoeisha S. , Favre Camille , Friscourt Frédéric , Wagenknecht Hans‐Achim 
Published: October 2021

AbstractSydnones are highly stable mesoionic 1,3‐dipoles that react with cyclooctynes through strain‐promoted sydnone‐alkyne cycloaddition (SPSAC). Although sydnones have been shown to be valuable bioorthogonal chemical reporters for the labeling of proteins and complex glycans, nucleic acids have not yet been tagged by SPSAC. Evaluation of SPSAC kinetics with model substrates showed fast reactions with cyclooctyne probes (up to k=0.59 M−1 s−1), and two different sydnones were effectively incorporated into both 2’‐deoxyuridines at position 5, and 7‐deaza‐2’‐deoxyadenosines at position 7. These modified nucleosides were synthetically incorporated into single‐stranded DNAs, which were successfully postsynthetically labeled with cyclooctyne probes both in vitro and in cells. These results show that sydnones are versatile bioorthogonal tags and have the premise to become essential tools for tracking DNA and potentially RNA in living cells.
THF‐solvated Heavy Alkali Metal Benzyl Compounds (Na, Rb, Cs): Defined Deprotonation Reagents for Alkali Metal Mediation Chemistry
Authors: Brieger Lukas , Unkelbach Christian , Strohmann Carsten 
Published: October 2021

AbstractThe incorporation of heavy alkali metals into substrates is both challenging and essential for many reactions. Here, we report the formation of THF‐solvated alkali metal benzyl compounds [PhCH2M ⋅ (thf)n] (M=Na, Rb, Cs). The synthesis was carried out by deprotonation of toluene with the bimetallic mixture n‐butyllithium/alkali metal tert‐butoxide and selective crystallization from THF of the defined benzyl compounds. Insights into the molecular structure in the solid as well as in solution state are gained by single crystal X‐ray experiments and NMR spectroscopic studies. The compounds could be successfully used as alkali metal mediating reagents. The example of caesium showed the convenient use by deprotonating acidic C−H as well as N−H compounds to gain insight into the aminometalation using these reagents.
Cobalt‐Catalyzed Dehydrogenative C−H Silylation of Alkynylsilanes
Authors: Stachowiak Hanna , Kuciński Krzysztof , Kallmeier Fabian , Kempe Rhett , Hreczycho Grzegorz 
Published: October 2021

AbstractHerein, we report that a cobalt catalyst permits the general synthesis of substituted alkynylsilanes through dehydrogenative coupling of alkynylsilanes and hydrosilanes. Several silylated alkynes, including di‐ and trisubstituted ones, were prepared in a one‐step procedure. Thirty‐seven compounds were synthesized for the first time by applying our catalyst system. The alkynylsilanes bearing hydrosilyl moieties provide an opportunity for further functionalization (e. g., hydrosilylation). The use of primary silanes as substrates and precatalyst activators permits the use of inexpensive and easily accessible 3d metal precatalysts, and avoids the presence of additional activators.
Pharmacokinetic Drug‐Drug Interaction Study of Omecamtiv Mecarbil With Amiodarone and Digoxin in Healthy Subjects
Authors: Trivedi Ashit , Sohn Winnie , Hsu Cheng‐Pang , Jafarinasabian Pegah , Zhang Hanze , Hutton Shauna , Flach Stephen , Abbasi Siddique , Dutta Sandeep , Lee Edward 
Published: October 2021

AbstractOmecamtiv mecarbil (OM), a novel cardiac myosin activator, is being evaluated for the treatment of heart failure with reduced ejection fraction. In vitro studies demonstrate OM as a substrate and inhibitor of P‐glycoprotein (P‐gp), which can result in drug‐drug interactions. Two phase 1, open‐label studies assessed the effect of coadministration of OM (50‐mg single dose) on the pharmacokinetics of digoxin (0.5‐mg single dose; N = 15), a P‐gp substrate, and the effect of coadministration of amiodarone (600‐mg single dose), a P‐gp inhibitor, on the pharmacokinetics of OM (50‐mg single dose; N = 14) in healthy subjects. The ratios of the geometric least squares mean (90% confidence interval [CI]) of digoxin coadministered with OM vs digoxin alone for area under the plasma concentration–time curve (AUC) from time 0 to infinity, AUC from time 0 to the time of the last quantifiable concentration, and maximum observed plasma concentration were 1.06 (90%CI, 0.99‐1.14), 1.06 (90%CI, 0.98‐1.14), and 1.08 (90%CI, 0.92‐1.26), respectively. The ratios of the geometric least squares mean of OM coadministered with amiodarone vs OM alone for AUC from time 0 to infinity, AUC from time 0 to the time of the last quantifiable concentration, and maximum observed plasma concentration were 1.21 (90%CI, 1.08‐1.36), 1.21 (90%CI, 1.07‐1.36), and 1.08 (90%CI, 0.96‐1.22), respectively. In conclusion, OM coadministered with digoxin or amiodarone did not result in any clinically relevant pharmacokinetic drug‐drug interactions.
Mixed Valence (μ‐Phenoxido) FeIIFeIII and FeIIIFeIV Compounds: Electron and Proton Transfers
Authors: Dubourdeaux Patrick , Blondin Geneviève , Latour Jean‐Marc 
Published: October 2021

AbstractMixed‐valence non‐heme diiron centers are present at the active sites of a few enzymes and confer them interesting reactivities with the two ions acting in concert. Related (μ‐phenoxido)diiron complexes have been developed as enzyme mimics. They exhibit very rich spectroscopic properties enabling independent monitoring of each individual ion, which proved useful for mechanistic studies of catalytic hydrolysis and oxidation reactions. In our studies of such complexes, we observed that these compounds give rise to a wide variety of electron transfers (intervalence charge transfer), proton transfers (tautomerism), coupled electron and proton transfers (H. abstraction and PCET). In this minireview, we present and analyze the main results illustrating the latter aspects.
Hydrogen Bonding and Vaporization Thermodynamics in Hexafluoroisopropanol‐Acetone and ‐Methanol Mixtures. A Joined Cluster Analysis and Molecular Dynamic Study
Authors: Marchelli Gwydyon , Ingenmey Johannes , Hollóczki Oldamur , Chaumont Alain , Kirchner Barbara 
Published: October 2021

AbstractBinary mixtures of hexafluoroisopropanol with either methanol or acetone are analyzed via classical molecular dynamics simulations and quantum cluster equilibrium calculations. In particular, their populations and thermodynamic properties are investigated with the binary quantum cluster equilibrium method, using our in‐house code Peacemaker 2.8, upgraded with temperature‐dependent parameters. A novel approach, where the final density from classical molecular dynamics, has been used to generate the necessary reference isobars. The hydrogen bond network in both type of mixtures at molar fraction of hexafluoroisopropanol of 0.2, 0.5, and 0.8 respectively is investigated via the molecular dynamics trajectories and the cluster results. In particular, the populations show that mixed clusters are preferred in both systems even at 0.2 molar fractions of hexafluoroisopropanol. Enthalpies and entropies of vaporization are calculated for the neat and mixed systems and found to be in good agreement with experimental values.
Body sensor network encryption and team user authentication scheme based on electrocardiogram detector
Authors: Ramadoss Janarthanan 
Published: October 2021

SummaryBody sensor network (BSN)/wireless body area networks (WBANs) is one of the essential aspects of the Internet of Things (IoT), which is possible to track the patient's essential biological and cognitive data through wearable sensors. The WBAN is easily accessible due to open sources; data security and privacy should be maintained throughout the communication characteristics. Due to the advancement of technology, BSN is restricted in a wide range of clinical applications. BSN is used to monitor the physiological characteristics continuously. The data can be easily traced by the attackers where the fingerprint scanners obtained can be used for the user authentication because of its wireless communication. This paper proposes a body sensor network encryption and user authentication (BSN‐EUA) scheme based on the ECG detector. BSN‐EUA scheme is used to provide the fingerprint scanners for user authentication, and all the activities regarding the health of a person are recorded on the mobile phone. The electrocardiogram's (ECG) descriptive characteristics are used throughout the authentication process as a recognizable fingerprint parameter. Quick community security protocols are then provided across all certified sensors where minor adjustments are needed to update the key generation mechanism on the sensor's side. Evaluation results show that the methodology suggested could reach the required security requirements and avoid several threats.
Simultaneous determination of mitotane, its metabolite, and five steroid hormones in urine samples by capillary electrophoresis using β‐CD2SDS1 complexes as hydrophobic compounds solubilizers
Authors: Pieckowski Michał , Kowalski Piotr , Olędzka Ilona , Miękus‐Purwin Natalia , Plenis Alina , Roszkowska Anna , Bączek Tomasz 
Published: October 2021

AbstractMitotane is a cytotoxic drug used in the treatment of inoperable adrenocortical carcinoma, it inhibits steroidogenesis as well, and therefore monitoring the level of steroid hormones in patients treated with mitotane is a crucial point of therapy. Hence, we have developed a simple, fast, and efficient electrophoretic method combined with reverse polarity sweeping as online preconcentration technique and dispersive liquid–liquid microextraction for the simultaneous determination of mitotane, its main metabolite DDA, and five steroid hormones (progesterone, testosterone, epitestosterone, cortisol, and corticosterone) in urine samples. In addition, a new sample matrix consisting of β‐CD2SDS1 complexes for a high hydrophobic compounds solubilization was developed. Approach based on the application of β‐cyclodextrin and SDS complex of a ratio 2:1 allowed for hydrodynamic injection into the capillary of a solution containing both mitotane and other analytes. The detection limits of the analytes for the reverse polarity sweeping‐dispersive liquid–liquid microextraction method were found to be in the range of 1.5–3 ng/mL, which were approximately 1000 times lower than in the conventional hydrodynamic injection (5 s, 0.5 psi) without any preconcentration procedure. All analytes were completely resolved in less than 13 min by uncoated silica capillary with an inner diameter of 75 μm (ID) × 60 cm. Electrophoretic separation was performed in reverse polarity with a voltage of –25 kV with a background electrolyte (BGE) consisting of 100 mM SDS, 25% ACN, 25 mM phosphate buffer (pH 2.5), and 7 mM β‐cyclodextrin.
Friction calculation and packing effect analysis for gravel packing in deepwater horizontal wells
Authors: Wen Min , Huang Hui , Zhou Shengtian , Fan Baitao , Qiu Hao 
Published: October 2021

AbstractGravel packing is one of the most commonly used well‐completion methods for controlling sand production in deepwater horizontal gas wells. Both the gravel‐packing mechanisms and the technical difficulties of gravel packing in a horizontal well are discussed in this paper. Subsequently, packing simulations were conducted based on geological data from a well in the LS gas field in the northern South China Sea. The factors influencing the gravel‐packing process were quantitatively analyzed. The influences of the pump rate, carrying fluid leak‐off ratio, and density of gravel on the sand‐dune ratio of the α‐wave, height of the sand dune, packing length of the α‐wave, and packing pressure were analyzed. The results show that the pipe string injection friction is the largest at the slurry injection stage and the α‐wave packing stage. In the β‐wave packing stage, the downhole horizontal flow friction becomes the main pressure loss. The friction increased when the β‐wave packing reached the heel of the horizontal wells. As a result, the packing pressure can easily exceed the formation fracture pressure. Furthermore, the lower the pump rate, the higher the sand‐dune ratio, which would cause premature screen‐out and blockage. Therefore, optimizing the pump rate is essential to ensure that the sand‐dune ratio meets the designed requirements. Under a certain leak‐off rate, the lower the gravel density, the longer the packing length of the α‐wave. For a long horizontal well, the step‐down method can be used to control the packing pressure during the β‐wave packing stage. The results provide technical support for field gravel packing.
Exploring opportunities for math learning within parent–infant interactions
Authors: Leech Kathryn A. , Herbert Kaitlin , Yang Qianru Tiffany , Rowe Meredith L. 
Published: October 2021

AbstractChildren's mathematical knowledge at school entry varies considerably and predicts long‐term achievement outcomes. Differences in children's exposure to math and number talk at home may help to explain variations in school‐entry math ability. However, nearly all research on exposure to math and number talk has been conducted with parents and preschool‐aged children. This longitudinal study examined to what extent parents talk about math with their 10‐, 14‐ and 18‐month infants during play. Additional analyses examined factors to explain variation in parent math talk at the family level (socio‐economic status), parent level (beliefs about children's mathematical development) and child level (gender). Transcripts of dyadic play sessions were coded for references to numbers and math concepts (e.g., first, many, more). It was found that parents do talk about numbers and math concepts with infants, albeit rarely, and such language increases in frequency and complexity over time. Parents use more statements than questions about math, and most often reference small‐number terms (1–3). Neither socio‐economic status nor beliefs were predictive of parental math talk. However, parents used significantly more math references over time with boys than girls. The results are discussed in terms of the importance of social interactions during infancy in fostering children's mathematical knowledge.
In vivo evaluation of bone repair guided with biological membrane based on polyhydroxybutyrate and norbixin
Authors: Sousa Rayssilane C. , Viana Vicente G. F. , Meneses Luiz F. C. , Maia Filho Antônio L. M. , Santos Francisco E. P. , Azevedo Marleane M. F. , Nascimento Hélio M. S. , Pinto Lucielma S. S. , Vasconcelos Daniel F. P. 
Published: October 2021

AbstractThe present work aimed to synthesize and verify the effectiveness of the polyhydroxybutyrate and norbixin membrane as a scaffold in bone defects induced in the tibia of rats. Twenty‐four male Rattus norvegicus rats were used, divided into control and membrane groups. After anesthesia, a bone defect was induced in the right tibia, followed by the implantation of the biomaterial at the site of the lesion only in the membrane group, with euthanasia after 15 and 30 days of the experiment. The deposition of organic and inorganic matrix, the quality of newly formed bone tissue and the morphology of the bone defect were measured. After 15 days of the experiment, the biomaterial significantly influenced the deposition of hydroxyapatite crystals, the formation of collagen I matrix and mineralization content in relation to the control group, in addition to the abbreviation of the inflammatory process and superior quality of the newly formed bone tissue. After 30 days, only the membrane group had fully completed its repair process. The biomaterial acted as a scaffold in the regeneration of the guided bone defect by accelerating the synthesis of collagen matrix, mineralization content, density, and maturity when compared to the control group.
The passive behavior of biomedical alloys in simulated physiological solutions
Authors: Pound Bruce G. 
Published: October 2021

AbstractPassive alloys are commonly considered to exhibit a current that is essentially independent of potential over the passive range in neutral chloride solutions. However, the current‐potential dependence of Ti and its alloys, CoCr alloys, and 316L stainless steel in buffered, simulated physiological solutions containing phosphate differs from that usually reported for the alloys in chloride‐only solutions. An analysis of potentiodynamic polarization data from previous studies showed that these alloys typically exhibit an exponential dependence of current on potential—as reflected by Tafel‐type behavior—over the initial part of the passive range in buffered solutions. This behavior is consistent with that predicted by the Generalized Growth Model for film growth and dissolution in the case of thin films where cation migration through the film is the rate‐controlling step and where the anodic current is associated predominantly with dissolution. Film growth is thought to be impeded in the buffered solutions, allowing the rate of migration and hence dissolution to remain relatively high over a wider potential range. Analysis of the apparent Tafel slopes indicated that the Ti and CoCr alloys exhibit a similar corrosion mechanism, with a small difference in the slopes for the two groups of alloys being attributable to the difference in the type of oxide. Stainless steel 316L exhibits a distinctly higher apparent Tafel slope, which is likely associated in large part with the duplex nature of the oxide.
Medicinal perspective of quinazolinone derivatives: Recent developments and structure–activity relationship studies
Authors: Wahan Simranpreet K. , Sharma Bharti , Chawla Pooja A. 
Published: October 2021

AbstractHeterocyclic rings have long piqued the interest of medicinal chemists. Quinazolinone is a fused nitrogen‐based heterocyclic moiety. Some of quinazolinone derivatives have emerged as marketed drugs. A tremendous number of pharmacological activities such as anticancer, anticonvulsant, antimalarial, antifungal, antibacterial, antiinflammatory, MMP inhibitors, antidiabetic, antileishmanial, and hypolipidemic properties have been explored. A number of quinazolinone derivatives have already paved way in various stages of clinical trials. An extensive literature on developed synthetic schemes based on green chemistry and biological activities of quinazolinone has been included in this study. The content of patent filed and granted of various quinazolinone‐based compounds are also mentioned.
The essential oil of the condiment species Clinopodium thymifolium (Scop.) Kuntze: new natural products and seasonal variation
Authors: Dekić Milan , Radulović Niko , Antonijević Marko , Dekić Dušica , Ličina Braho 
Published: October 2021

AbstractBACKGROUNDClinopodium thymifolium is an aromatic plant species that is widespread in the Mediterranean region. It has been considered as a condiment and is used in cooking. As a promising spice plant, some efforts are being made to introduce this plant as a new crop species and it has been successfully cultivated in northern Italy.RESULTSEssential oils isolated from the aerial parts of a flavoring species C. thymifolium were analyzed by gas chromatography and gas chromatography/mass spectrometry. The results of a detailed analysis of the chemical composition of the oils showed the domination of pulegone, piperitone, piperitenone and isomenthone, as well as a significant alteration of the pulegone/isomenthone ratio with the developmental stage of the plant. Additionally, a comprehensive chemical analysis of the oils in combination with detailed spectral analyses and chemical synthesis of selected compounds has led to the identification of two new natural products: isomenthyl formate and neomenthyl 2‐methylbutanoate.CONCLUSIONThe observed chemical variability at the intrapopulation level appeared to be a phenological variation. In an evolutionary sense, the alteration of the pulegone/isomenthone ratio suggests their possible role in the ecological adaptation of the species to pollinators. Significant quantitative changes in the chemical composition of the oil at different phenological stages may be relevant in the case of plant material intended for edible purposes. © 2021 Society of Chemical Industry.
Supercritical fluid chromatography for the analysis of natural dyes: From carotenoids to flavonoids
Authors: Lesellier Eric , West Caroline 
Published: October 2021

AbstractPlant‐derived natural dyes are used in a variety of formulated products, from food to cosmetics and pharmaceutics. In addition to their color, they also provide some bioactivity. While they are mostly analyzed with high‐performance liquid chromatography, supercritical fluid chromatography was also employed for several dye families, mostly for carotenoids and chlorophylls, and more recently for anthraquinones and flavonoids. These supercritical fluid chromatography methods are described in this review. Because the dyes have different structures and structural variations (polarity, isomers, etc.), the best chromatographic system to achieve their separation is not always the same. Hydrophobic stationary phases are preferred for the most hydrophobic dyes (chlorophylls and carotenoids) while polar stationary phases are preferred for the polar dyes (anthraquinones and flavonoids). Regarding the mobile phase composition, chlorophylls and carotenoids are best eluted with moderate proportions of co‐solvent in CO2 (about 40%), while the most polar glycosylated flavonoids require higher proportions of co‐solvent and acidic additives. Because dyes are colorful, ultraviolet‐visible detection is often sufficient, while mass spectrometry offers additional structural information. Furthermore, fundamental information can also be gained through chromatographic analysis of dyes: either solubility in supercritical fluids, in view of their extraction, or retention behavior providing an understanding of stationary phase properties.
New Hyperbranched Polysiloxanes Made by Thiol‐yne Click Reaction: Lanthanide Complexation and Applications in Bioimaging
Authors: Ding Guowei , Gai Fengqing , Wang Xiaoni , Gou Zhiming , Zuo Yujing 
Published: October 2021

AbstractHyperbranched polymers, as a unique highly branched polymers with low viscosity, simple synthesis, mixability and high reactivity, have received intensive attention and applied to many fields of resin modification, catalysts, and film materials. In this paper, hyperbranched polymers (P1 and P2) are designed and developed by the thiol‐yne “click” reaction with controlled molar ratio of reactant. After that, lanthanide ions are coordinated with P1 and P2 to prepare new hyperbranched polymer fluorescent products (P1‐Ln3+ and P2‐Ln3+). P1‐Ln3+ and P2‐Ln3+ exhibit excellent fluorescent properties, superb stability, and economic feasibility. Moreover, bioimaging experiments clearly exhibit that P1‐Ln3+ and P2‐Ln3+ has great potential in further biological applications.