bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorine‐Substituted Molecular Motors with a Quaternary Stereogenic Center
Authors: Štacko Peter , Kistemaker Jos C. M. , Feringa Ben L. 
Published: March 2017

AbstractA series of unprecedented second generation molecular motors featuring a quaternary stereogenic center substituted with a fluorine atom has been synthesized. It is demonstrated that a seemingly benign replacement of the stereogenic hydrogen for a fluorine atom, regarded as a common substituent in pharmacology, resulted in a dramatic change in the energetic profile of thermal helix inversion. The barrier for the thermal helix inversion was found to increase considerably (by 20–30 kJ mol−1), presumably due to destabilization of the transition state by increased steric hindrance when the fluorine atom is forced to pass over the lower half of the motor. This results in the activation barrier for the thermal helix inversion to be higher than the barrier for backward thermal E–Z isomerization, impairing the motor function. A fluorine‐substituted motor capable of performing unidirectional rotation is successfully prepared when these limitations are considered in the design phase.
Inhibitory Mechanism of Epigallocatechin Gallate on Fibrillation and Aggregation of Amidated Human Islet Amyloid Polypeptide
Authors: Xu Zhi‐Xue , Ma Gong‐Li , Zhang Qiang , Chen Cong‐Heng , He Yan‐Ming , Xu Li‐Hui , Zhou Guang‐Rong , Li Zhen‐Hua , Yang Hong‐Jie , Zhou Ping 
Published: March 2017

AbstractThe abnormal fibrillation of human islet amyloid polypeptide (hIAPP) is associated with development of type II diabetes mellitus (T2DM). (−)‐Epigallocatechin gallate (EGCG) can bind amyloid proteins to inhibit the fibrillation of these proteins. However, the mechanic detail of EGCG inhibiting amyloid formation is still unclear at the molecular level. In the present work, we sought to investigate the effect of EGCG on amidated hIAPP (hIAPP‐NH2) fibrillation and aggregation by using spectroscopic and microscopic techniques, and also sought to gain insights into the interaction of EGCG and hIAPP22–27 by using spectroscopic experiments and quantum chemical calculations. ThT fluorescence, real‐time NMR, and TEM studies demonstrated that EGCG inhibits the formation of hIAPP‐NH2 fibrils, while promoting the formation of hIAPP‐NH2 amorphous aggregates. Phenylalanine intrinsic fluorescence and NMR studies of the EGCG/hIAPP22–27 complex revealed three important binding sites including the A ring of EGCG, residue Phe23, and residue Ile26. DFT calculations identified the dominant binding structures of EGCG/Phe23 and EGCG/Ile26 complexes, named structure I and structure II, respectively. Our study demonstrates the inhibitory mechanism of EGCG on fibrillation and aggregation of hIAPP‐NH2 in which EGCG interacts with hIAPP‐NH2 through hydrogen bonding and π–π interactions between the A ring and residue Phe23 as well as hydrophobic interactions between the A ring and residue Ile26, which can thus inhibit the interpeptide interaction between hIAPP‐NH2 monomers and finally inhibit fibrillation of hIAPP‐NH2. This study agrees with and reinforces previous studies and offers an intuitive explanation at both the atomic and molecular levels. Our findings may provide an invaluable reference for the future development of new drugs in the management of diabetes.
The impact of binding of macrocyclic metal complexes on amyloid fibrillization of insulin and lysozyme
Authors: Kovalska Vladyslava , Chernii Svitlana , Cherepanov Vsevolod , Losytskyy Mykhaylo , Chernii Victor , Varzatskii Oleg , Naumovets Anton , Yarmoluk Sergiy 
Published: March 2017

AbstractAmyloid fibrils are insoluble protein aggregates whose accumulation in cells and tissues is connected with a range of pathological diseases. We studied the impact of 2 metal complexes (axially coordinated Hf phthalocyanine and iron (II) clathrochelate) on aggregation of insulin and lysozyme. For both proteins, the host‐guest interaction with these compounds changes the kinetics of fibrillization and affects the morphology of final aggregates.The Hf phthalocyanine is a very efficient inhibitor of insulin fibrillization; in its presence, only very low amounts of fibrils with the diameters of 0.8 to 5 nm and spherical aggregates were found. Effective concentration of fibrillization inhibition (IC50) was estimated to be 0.11 ± 0.04 μM. The clathrochelate induced the formation of thin fibrils with the diameters of 0.8 to 2.5 nm; IC50 was estimated as 20 ± 9 μM. The lysozyme fibrillization remained quite intensive in the presence of the studied compounds; they induced the formation of long filaments (the length up to 2.5 μm, the diameters of 1.5‐3.5 nm). These fibrils noticeably differed from those of free lysozyme short linear species (the diameters of 3‐5 nm, the length up to 0.6 μm).Thinning and elongation of fibrils suggest that the metal complexes bind mainly to the grooves of protofilaments; this hinders the stacking of early aggregates or protofilaments together but does not hinder their growth. The image of the fibril separated into 2 protofilaments allows suggesting that the fibril formation occurs via the growth of the parallel protofilaments with their subsequent twisting in the fibril. The changes of the lysozyme intrinsic fluorescence indicate that both metal complexes interact with the protein during the stage of the fibrillar seeds formation.
Effect of Surfactants on Zero‐Valent Iron Nanoparticles (NZVI) Reactivity
Authors: Wang Ziheng , Choi Francis , Acosta Edgar 
Published: March 2017

AbstractZero‐valent iron nanoparticles (NZVI) were synthesized and dispersed in solutions of sodium oleate (SO), sodium laurate (SL), sodium dodecyl phosphonate (SDP), and sodium dodecyl sulfate (SDS). The reactivity of these dispersions was evaluated to assess the impact of surfactants on the reduction rate of hydrophilic reactive black 5 (RB5) and hydrophobic carbon tetrachloride (CT) model contaminants. SO and SL, used at their critical micelle concentration (CMC), lowered the reduction rate of RB5 by two and three orders of magnitude, respectively. SO and SL also decreased the reduction rate of CT by up to one order of magnitude. SDS and SDP, at their CMC, decreased the reduction rate of RB5 by approximately 50‐fold, but increased the reduction rate of CT. The decrease in RB5 reduction rate might be explained by the formation of adsorbed surfactant species on the surface of NZVI that could hinder the transport of RB5 and other hydrophilic species. For SO and SL, the inhibition of RB5 and CT reduction might also be explained by the binding of carboxylates to NZVI. The increase in CT reduction rate with SDS and SDP suggests that providing a non‐binding lipophilic environment on the surface of NZVI would improve the reduction rate and selectivity towards the reduction of hydrophobic contaminants.
Dietary Conjugated Linoleic Acid‐c9t11 Prevents Collagen‐Induced Arthritis, Whereas Conjugated Linoleic Acid‐t10c12 Increases Arthritic Severity
Authors: Muhlenbeck Jessica A. , Butz Daniel E. , Olson Jake M. , Uribe‐Cano Daniela , Cook Mark E. 
Published: March 2017

AbstractTwo conjugated linoleic acid (CLA) isomers, cis‐9, trans‐11 (CLAc9t11) and trans‐10, cis‐12 (CLAt10c12), reduce inflammation in a number of animal models, including collagen‐induced arthritis (CA). However, little is known about the ability of individual CLA isomers to prevent autoimmune disease onset. Evidence that mixed isomer CLA drives T helper cell (Th) 1 responses suggests that CLA, or a specific isomer, exacerbates onset of Th1 autoimmune diseases. In two experiments, we examined if prior dietary exposure to CLAt10c12 (experiment 1) or CLAc9t11 (experiment 2) affected the incidence or severity of CA. DBA/1 mice were fed a semi purified diet with either 6% corn oil (CO, w/w), 5.75% CO plus 0.25% CLAt10c12, or 5.5% CO plus 0.5% CLAc9t11 prior to arthritis development. Arthritis incidence and severity, anti‐collagen antibodies, paw cytokines, and hepatic fatty acids were measured. CLAt10c12 had no effect on arthritis incidence but increased arthritic severity (42%, P = 0.02); however, CLAc9t11 decreased arthritis incidence 39% compared to CO fed mice (P = 0.01), but had no effect on disease severity. CLAt10c12‐induced increase in anti‐collagen type II IgG antibodies may be a mechanism by which this isomer increased arthritic severity, and CLAc9t11‐induced increase in Th2 paw cytokines (IL‐4 and IL‐10, P ≤ 0.04) may explain how CLAc9t11 reduced the arthritis incidence. While both isomers are well known to reduce inflammation in arthritic mice, these new data suggest isomer differences when fed prior to autoimmune disease.
Breaking down temporal distance in a Continental French variety: Future temporal reference in Vimeu
Authors: Villeneuve Anne-José , Comeau Philip 
Published: March 2017

AbstractThis article examines future temporal reference (FTR) in the French spoken in Vimeu, a rural area of France where French evolved alongside Picard, a Gallo-Romance regional language. Unlike most French varieties, which favour periphrasis, Vimeu Picard favours the inflected form. By comparing French data from Picard–French bilinguals and French monolinguals, we assess the potential effect of Picard contact on Vimeu French. We hypothesized that bilinguals may favour the inflected form more than monolinguals, a hypothesis that was not verified. Instead, education is the best social predictor: speakers with a baccalauréat or higher disfavour the periphrastic future. Regarding linguistic constraints, we expected sentential polarity to constrain FTR (negation favours the inflected form), as in many varieties. Surprisingly, only temporal distance constrains FTR in our data: proximate events favour periphrasis, and do so even more strongly with events to occur within the minute. These results suggest that Vimeu French marks imminence through periphrasis.
Variability in Antifungal and Antiviral Use in Hospitalized Children
Authors: Goldman Jennifer L. , Ross Rachael K. , Lee Brian R. , Newland Jason G. , Hersh Adam L. , Kronman Matthew P. , Gerber Jeffrey S. 
Published: March 2017

We analyzed antifungal and antiviral prescribing among high-risk children across freestanding children’s hospitals. Antifungal and antiviral days of therapy varied across hospitals. Benchmarking antifungal and antiviral use and developing antimicrobial stewardship strategies to optimize use of these high cost agents is needed.Infect Control Hosp Epidemiol2017;38:743–746
Leishmania infantum in domestic cats from the municipality of Teresina, state of Piauí, Brazil
Authors: DE MENDONÇA IVETE L. , BATISTA JOILSON F. , RIBEIRO IULIANA M. M. , ROCHA FERNANDA S. B. , SILVA SORAIA O. , MELO MARIA N. 
Published: March 2017

SUMMARYFeline leishmaniasis has been reported in various parts of the world in recent years, occurring mainly in areas where zoonotic visceral leishmaniasis (VL) is endemic. The purpose of this study was to assess the occurrence of natural infection byLeishmaniaspp. in domestic cats (Felis catus) in the municipality of Teresina, Piauí state, Brazil, an endemic area of VL in Brazil. The prevalence of infection byLeishmaniaspp. in the population under study was 4% (3/83) in the enzyme-linked immunosorbent assay (ELISA) and 4% (3/83) by smear observation and isolation in a culture medium, using popliteal lymphnode sample. Only one of the three infected cats was positive for ELISA, also being positive for feline immunodeficiency virus. In the haematologic parameters, normocytic normochromic anaemia was the most common change, being present in the three infected animals. In the biochemical measurements also were observed alterations in infected animals. TheLeishmaniaspp. strains isolated from the culture medium were characterized asL. infantum. The presence ofL. infantuminfection in cats in the city of Teresina, an area endemic for VL, suggests the possible involvement of these animals in the epidemiological chain ofL. infantumin high-transmission areas.
WHAT’S IN A NAME? DELIA IN TIBULLUS 1.1
Authors: Kennedy Duncan F. 
Published: March 2017

Delia, the name given to Tibullus’ mistress in five of the poems in the first book of his elegies (1.1, 1.2, 1.3, 1.5, 1.6), has long inspired curiosity. Two approaches have dominated discussion. The biographical approach takes its cue from theApologyof Apuleius (10), which regards Delia as a pseudonym:eadem igitur opera accusent C. Catullum, quod Lesbiam pro Clodia nominarit, et Ticidam similiter, quod quae Metella erat Perillam scripserit, et Propertium, qui Cynthiam dicat, Hostiam dissimulet, et Tibullum, quod ei sit Plania in animo, Delia in uersu.
Microstructure and Quantitative Micromechanical Analysis of Wood Cell–Emulsion Polymer Isocyanate and Urea–Formaldehyde Interphases
Authors: Qin Lizhe , Lin Lanying , Fu Feng , Fan Mizi 
Published: March 2017

AbstractEmulsion polymer isocyanate (EPI) and urea-formaldehyde (UF) were selected as typical resin systems to investigate the microstructure of wood–adhesive interphases by fluorescence microscopy (FM) and confocal laser scanning microscopy (CLSM). Further, a quantitative micromechanical analysis of the interphases was conducted using nanoindentation. The FM results showed that the UF resin could penetrate the wood to a greater extent than the EPI resin, and that the average penetration depth for these two resin systems was higher in the case of latewood. CLSM allowed visualization of the resin distribution with contrasting colors, showing that the EPI resin could not penetrate the cell wall, whereas UF resin could enter the cell walls. The micromechanical properties of the cell walls were almost unaffected by EPI penetration but were significantly affected by UF penetration, especially in the first cell wall from the glueline. This further confirmed that only cell walls with resin penetration can improve the mechanical properties of the interphase regions.
Proposal for dark exciton based chemical sensors
Authors: Feierabend Maja , Berghäuser Gunnar , Knorr Andreas , Malic Ermin 
Published: March 2017

AbstractThe rapidly increasing use of sensors throughout different research disciplines and the demand for more efficient devices with less power consumption depends critically on the emergence of new sensor materials and novel sensor concepts. Atomically thin transition metal dichalcogenides have a huge potential for sensor development within a wide range of applications. Their optimal surface-to-volume ratio combined with strong light–matter interaction results in a high sensitivity to changes in their surroundings. Here, we present a highly efficient sensing mechanism to detect molecules based on dark excitons in these materials. We show that the presence of molecules with a dipole moment transforms dark states into bright excitons, resulting in an additional pronounced peak in easy accessible optical spectra. This effect exhibits a huge potential for sensor applications, since it offers an unambiguous optical fingerprint for the detection of molecules—in contrast to common sensing schemes relying on small peak shifts and intensity changes.
Network analysis reveals crosstalk between autophagy genes and disease genes
Authors: Wang Ji-Ye , Yao Wei-Xuan , Wang Yun , Fan Yi-lei , Wu Jian-Bing 
Published: March 2017

AbstractAutophagy is a protective and life-sustaining process in which cytoplasmic components are packaged into double-membrane vesicles and targeted to lysosomes for degradation. Accumulating evidence supports that autophagy is associated with several pathological conditions. However, research on the functional cross-links between autophagy and disease genes remains in its early stages. In this study, we constructed a disease-autophagy network (DAN) by integrating known disease genes, known autophagy genes and protein-protein interactions (PPI). Dissecting the topological properties of the DAN suggested that nodes that both autophagy and disease genes (inter-genes), are topologically important in the DAN structure. Next, a core network from the DAN was extracted to analyze the functional links between disease and autophagy genes. The genes in the core network were significantly enriched in multiple disease-related pathways, suggesting that autophagy genes may function in various disease processes. Of 17 disease classes, 11 significantly overlapped with autophagy genes, including cancer diseases, metabolic diseases and hematological diseases, a finding that is supported by the literatures. We also found that autophagy genes have a bridging role in the connections between pairs of disease classes. Altogether, our study provides a better understanding of the molecular mechanisms underlying human diseases and the autophagy process.
Tunable Twin Matching Frequency (fm1/fm2) Behavior of Ni1−xZnxFe2O4/NBR Composites over 2–12.4 GHz: A Strategic Material System for Stealth Applications
Authors: Saini Lokesh , Patra Manoj Kumar , Jani Raj Kumar , Gupta Goutam Kumar , Dixit Ambesh , Vadera Sampat Raj 
Published: March 2017

AbstractThe gel to carbonate precipitate route has been used for the synthesis of Ni1−xZnxFe2O4 (x = 0, 0.25, 0.5 and 0.75) bulk inverse spinel ferrite powder samples. The optimal zinc (50%) substitution has shown the maximum saturation magnetic moment and resulted into the maximum magnetic loss tangent (tanδm) > −1.2 over the entire 2–10 GHz frequency range with an optimum value ~−1.75 at 6 GHz. Ni0.5Zn0.5Fe2O4- Acrylo-Nitrile Butadiene Rubber (NBR) composite samples are prepared at different weight percentage (wt%) of ferrite loading fractions in rubber for microwave absorption evaluation. The 80 wt% loaded Ni0.5Zn0.5Fe2O4/NBR composite (FMAR80) sample has shown two reflection loss (RL) peaks at 5 and 10 GHz. Interestingly, a single peak at 10 GHz for 3.25 mm thickness, can be scaled down to 5 GHz by increasing the thickness up to 4.6 mm. The onset of such twin matching frequencies in FMAR80 composite sample is attributed to the spin resonance relaxation at ~5 GHz (fm1) and destructive interference at λm/4 matched thickness near ~10 GHz (fm2) in these composite systems. These studies suggest the potential of tuning the twin frequencies in Ni0.5Zn0.5Fe2O4/NBR composite samples for possible microwave absorption applications.
Three dimensional approach to investigating biological effects along energetic ion beam pathways
Authors: Li Xinglin , Sun Shuguang , Wang Shanying , Li Wenjian , Qu Ying , Cui Weidong , Sun Tianren , Zhang Jian , Wang Jufang , Zhou Guangming , Man Shuli , Chen Yi , Lu Fuping , Wei Zengquan , Jin Genming 
Published: March 2017

AbstractHeavy ion beams have many exciting applications, including radiotherapy of deep-seated tumors and simulation tests of space irradiation for astronauts. These beams often use a feature that concentrates the energy deposition largely along the end of the energy pathway, leading to different distributions of biological effects along the axial direction. Currently, there is relatively little information regarding the radial directional difference of biological effects along the heavy ion paths. This study utilized a filter membrane that was quantatively applied with cells to demonstrate a 3D distribution model of irradiation on biological effects in living organisms. Some results have indicated that there is excitatory effect on the non-irradiated regions with energetic ions, which may give new insights into the distribution of biological effects along the paths of heavy ion beams with mid-high energy.
Compact microstrip lowpass filter with ultra‐wide stopband based on dual‐plane structure
Authors: Jiang Shu , Xu Jinping 
Published: March 2017

A microstrip lowpass filter (LPF) with ultra‐wide stopband suppression and compact size based on dual‐plane structure is presented. The LPF is composed of high‐impedance resonators loaded by folded patches on the topside plane, combined with hybrid slot and step‐impedance resonators on the ground plane. Multiple transmission zeros are created in the stopband region by different resonators. Thus, an ultra‐wide stopband with 11th‐harmonic suppression is achieved. A demonstration filter with 3 dB cutoff frequency (fc) at 2.45 GHz has been designed, fabricated and measured. Results show that the relative stopband bandwidth is 163.8% with attenuation level of 20 dB. The insertion loss is lower than 0.3 dB and the return loss is better than 17 dB in the passband. The size of the LPF is only 8.90 mm × 8.93 mm, which corresponds to 0.115λg × 0.116λg (λg is the guided wavelength at fc).
Total Synthesis of Camptothecins: An Update
Authors: Chen Fen-Er , Chen Lei 
Published: March 2017

Over the last few decades, considerable research efforts have been directed toward the development of effective chemical syntheses of camptothecin and its analogs. The last comprehensive review of this area was published in 2003 and many effective new methods have since been reported for the stereoselective synthesis of the camptothecin alkaloids. In this account, we have summarized most of the novel synthetic approaches developed for the synthesis of camptothecins during the last decade. We have focused on strategies for the construction of the pentacyclic ring system and the different methods used to install the chiral quaternary center on the E ring of camptothecin.1	Introduction2	Synthesis of Racemic Camptothecins3	Enantioselective Synthesis of Camptothecins3.1	Sharpless Asymmetric Dihydroxylation3.2	Catalytic Asymmetric Cyanosilylation3.3	Auxiliary-Induced Asymmetric Carbonyl Addition3.4	Catalytic Asymmetric Ethylation3.5	Asymmetric Hydroxylation4	Conclusion
Strategies for preventing early-onset group B streptococcal infection: Physicians’ preferences and ratings of effectiveness and feasibility
Authors: ALLEN UPTON , MACDONALD NONI , NIMROD CARL , MARCHESSAULT VICTOR , KLASSEN TERRY 
Published: March 2017

Abstract

OBJECTIVE:
To determine the preferences of Canadian physicians for various strategies to prevent early-onset group B streptococcal (GBS) infection and the physicians’ ratings of the effectiveness and feasibility of these strategies.

DESIGN:
Questionnaire survey.

PARTICIPANTS:
Physicians working in primary or tertiary care settings in community-based and hospital-based practices.

MATERIALS AND METHODS:
Questionnaires were sent to infectious diseases/microbiology (ID/MICRO) specialists, neonatologists and obstetricians (OBs) across Canada between December 1, 1994 and January 31, 1995. Responses were accepted up to March 31, 1995.

RESULTS:
Responses were obtained from 257 physicians (37%), with the analyzable pool comprising 220 physicians. Significant differences in responses were documented. Antenatal GBS screening was indicated by 63% of 220 respondents. The majority of respondents (77%) indicated that antenatal screening occurred in the early third trimester at their centres. Seventy-two per cent of respondents (158 of 220) indicated that intrapartum penicillin was the standard of care for preventing GBS in their centres. ID/MICRO specialists and neonatologists were more likely to assign a top three preference ranking to the Canadian consensus option that involves screening at 26 to 28 weeks, compared with OB specialists (P&lt;0.001, P=0.008, respectively). The three most preferred options were considered to have ‘fair’ effectiveness. The option with the highest score on the feasibility rating was the Canadian consensus option that involved no screening, but intrapartum prophylaxis for high risk women.

CONCLUSION:
Given the significant disparity in responses, further efforts at information sharing and consensus building regarding the prevention of early-onset GBS are needed.