bluuebunny/crossref_metadata_2025 huggingface dataset:
Microtensile Bond Strength of Cad-Cam and Pressed-Ceramic Inlays to Dentin
Authors: Öztürk A Nilgün , İnan Özgür , İnan Erkan , Öztürk Bora
Published: September 2019

Objectives: CAD-CAM system is popular because of high esthetic and short fabrication time. But, there is limited information available about the microtensile bonding of luting cements to CAD-CAM inlays and to dentin. The aim of this study was to examine the bond strength of CAD-CAM (Cerec 3) and pressed-ceramic (IPS Empress 2) inlays to dentin surface by microtensile testing using two luting cements.

Materials and Methods: Standardized mesio-occlusal cavities were made in forty extracted molar teeth. An occlusal reduction of 2 mm was made; the bucco-lingual width of the proximal boxes was 4 mm, the occlusal width 3 mm and the depth of the pulpal and axial walls 2 mm. The proximal boxes were extended 1 mm below the cemento-enamel junction. Teeth were randomly assigned to 2 groups to evaluate the bonding of 2 ceramic systems, Cerec 3 (Group I) and IPS Empress 2 (Group II), to dentin. Each of the 2 groups were further divided into 2 luting cement groups, Panavia F (Group A) and Variolink II (Group B). After cementation, the teeth were sectioned into two 1.2x1.2 mm wide ‘I’ shape sections. The specimens were then subjected to microtensile testing at a crosshead speed of 1 mm/min. Twoway ANOVA and Tukey HSD tests were used to evaluate the results.

Results: The mean microtensile bond strengths of Cerec 3 and IPS Empress 2 bonding to dentin with luting agents in MPa were Panavia F (13.98±3.44), Variolink II (14.19±3.12) and Panavia F (15.12±3.15), Variolink II (15.45±3.08) respectively. No significant differences were found among the 2 ceramic systems (P>.05) and 2 luting cements with regard to dentin bond strengths (P>.05).

Conlusions: There was no difference found between the dentin bond strength of the Cerec 3 and IPS Empress 2 inlays cemented with two luting cements. (Eur J Dent 2007;2:91-96)
Gingival Hyperplasia as an Early Diagnostic Oral Manifestation in Acute Monocytic Leukemia: A Case Report
Authors: Demirer Serhat , Özdemir Hakan , Şencanc Mehmet , Marakoğlud Ismail
Published: September 2019

Acute Myeloblastic Leukemia (AML) is a malignant disease of bone marrow. Due to its high morbidity rate, early diagnosis and appropriate medical therapy is essential. Rapidly forming gingival hyperplasia is usually the first sign of this disease. This case report describes a 17-year-old female who presented rapid gingival overgrowth together with gingival bleeding in only two weeks time. A medical consultation was asked from hematology clinics and after a detailed medical examination Acute Monocytic Leukemia (FAB M5) was rendered. Chemotherapy was the choice of treatment. The patient responded well to chemotherapeutic induction regimen and after two months of medical therapy disease remised and gingival hyperplasia regressed. This case report shows that the gingival hyperplasia may represent an initial manifestation of an underlying systemic disease. Also, early medical therapy in acute monocytic leukemia may resolve the gingival hyperplasia that companies the disease progression. (Eur J Dent 2007;2:111-114)
Validity of a Manual Soft Tissue Profile Prediction Method Following Mandibular Setback Osteotomy
Authors: Kolokitha Olga - Elpis
Published: September 2019

Objectives: The aim of this study was to determine the validity of a manual cephalometric method used for predicting the post-operative soft tissue profiles of patients who underwent mandibular setback surgery and compare it to a computerized cephalometric prediction method (Dentofacial Planner). Lateral cephalograms of 18 adults with mandibular prognathism taken at the end of presurgical orthodontics and approximately one year after surgery were used.

Methods: To test the validity of the manual method the prediction tracings were compared to the actual post-operative tracings. The Dentofacial Planner software was used to develop the computerized post-surgical prediction tracings. Both manual and computerized prediction printouts were analyzed by using the cephalometric system PORDIOS. Statistical analysis was performed by means of t-test.

Results: Comparison between manual prediction tracings and the actual post-operative profile showed that the manual method results in more convex soft tissue profiles; the upper lip was found in a more prominent position, upper lip thickness was increased and, the mandible and lower lip were found in a less posterior position than that of the actual profiles. Comparison between computerized and manual prediction methods showed that in the manual method upper lip thickness was increased, the upper lip was found in a more anterior position and the lower anterior facial height was increased as compared to the computerized prediction method.

Conclusions: Cephalometric simulation of post-operative soft tissue profile following orthodonticsurgical management of mandibular prognathism imposes certain limitations related to the methods implied. However, both manual and computerized prediction methods remain a useful tool for patient communication. (Eur J Dent 2007;1:202-211)
Knowledge of and Attitudes towards Preventive Dental Care among Iranian Dentists
Authors: Ghasemi Hadi , Murtomaa Heikki , Torabzadeh Hassan , Vehkalahti Miira M
Published: September 2019

Objectives: To assess Iranian dentists’ knowledge of and attitudes towards preventive dental care

Methods: A questionnaire survey was conducted at two nationwide annual dental congresses in 2004 and 2005 in Tehran, Iran. Dentists’ level of knowledge was assessed based on their responses on a Likert scale (0-4) to nine statements on preventive dental care. Higher scores indicated more accurate knowledge. Dentists’ attitudes towards preventive dental care were rated based on responses on a Likert scale (1-7) to nine pairs of bipolar adjectives. The respondents were to choose the response which best described their opinion. Higher scores indicated more positive attitudes. Of 1033 responding dentists, 980 (64% men) were deemed eligible for this study. Statistical evaluation was by t-test and the Chi-square test

Results: Highest ratings were obtained for knowledge of the role of sugar consumption (Mean±SD: 3.73±0.60), sealants (3.58±0.68), and water fluoridation (3.35±0.81) in caries prevention; the lowest for their knowledge of the superiority of the use of fluoride toothpaste over technique of brushing (1.11±1.09). Dentists’ attitudes towards preventive dental care appeared most positive regarding its usefulness (Useful — Useless; 6.67±0.94), value (Valuable — Worthless; 6.59±0.98) to the community and for its status as a scientific (Scientific — Unscientific; 6.47±1.06) subject. Overall, female dentists had more favourable attitudes towards preventive dental care than male colleagues

Conclusions: Preventive dentistry should be emphasised in dental education in order to update dentists’ knowledge and attitudes regarding preventive dental care. (Eur J Dent 2007;1:222-229)
Chemical Colitis due to Peracetic Acid: a Case Report and Review of Literature
Authors: Zullo Angelo , Hassan Cesare , Guarini Alessandra , Lorenzetti Roberto , Campo Salvatore , Morini Sergio
Published: September 2019

Reprocessing of both endoscopic instruments and reusable disposals is mandatory to prevent infection transmission. However, toxic colitis due to endoscope contamination by different disinfectants following an imperfect washing has been reported. We present a case of peracetic acid-induced colitis and reviewed the literature. Overall, five cases of peracetic acid toxic colitis have been reported. All cases presented with “snow white sign” immediately appearing during endoscopy, two patients complaint of mild abdominal pain (one of whom had also fever and rectal bleeding), whilst the othesr remained totally asymptomatic. Only one patient received a 1-week metronidazole treatment. No immediate complications were observed, and no sequels occurred at clinical-endoscopic follow-up. The identified cause of disinfectant contamination was a defective either manual or automated rinsing of the colonoscope following the reprocessing procedure.( J Dig Endosc2011;2(1):15-17)
Optically detected ferromagnetic resonance in diverse ferromagnets via nitrogen vacancy centers in diamond
Authors: Page M. R. , McCullian B. A. , Purser C. M. , Schulze J. G. , Nakatani T. M. , Wolfe C. S. , Childress J. R. , McConney M. E. , Howe B. M. , Hammel P. C. , Bhallamudi V. P.
Published: September 2019

We report measurements of optically detected ferromagnetic resonance (ODFMR) in thin films using nitrogen-vacancy (NV) centers in diamond, whose fluorescence intensity changes in response to the ferromagnetic resonance (FMR) excitation of a proximal ferromagnet. Here, we extend the study of the off-resonant and broadband detection of FMR, first observed in the magnetic insulator YIG to a diverse set of ferromagnetic materials. We measure ODFMR signals from several technologically relevant metallic ferromagnetic materials including Py, Co, Co2(Mn0.6Fe0.4)Ge, and an insulating NiZnAl ferrite. These results show the generality of the spin-relaxation based coupling of the NV spins to the ferromagnetic dynamics that enables this detection. The observable field-frequency range of the ODFMR signal is dependent on material parameters such as saturation magnetization and damping. These results imply that NV-based ODFMR can give insights into nanoscale ferromagnetic dynamics and its damping processes, especially for samples with low magnetization and in the low field-frequency regime, which is important for several technologies.
Nonreciprocity and thermoelectric performance in a double-dot Aharonov–Bohm interferometer
Authors: Yan Yonghong , Wu Haifei , Jiang Feng , Zhao Hui
Published: September 2019

We investigate nonreciprocity and thermoelectric performance beyond the linear response regime in a double-dot Aharonov–Bohm interferometer that is connected to three reservoirs. In the presence of a magnetic flux (broken time-reversal symmetry), we find that the difference between the forward and reverse particle currents can reach the order of 10% under certain conditions. We also show that when the temperature gradient is reversed, the thermoelectric efficiency and output power both change; however, the discrepancies are minimal. Indeed, although breaking time-reversal symmetry can enhance the maximum efficiency, it reduces the maximum power in the present model. These results could be useful for the design of nanoscale thermoelectric devices.
A dynamical model of microwave window breakdown at vacuum/dielectric interface
Authors: Zhang Jianwei , Wang Hongguang , Liu Chunliang , Li Yongdong , Lin Shu , Luo Wei , Zhang Lei
Published: September 2019

A new dynamical model is built to describe the process of microwave window breakdown at the vacuum/dielectric interface. In this model, the effects of gas desorption and gas diffusion on breakdown are first taken into account. The evolution of the density of electrons and the neutral gas is analyzed. Particle-in-cell simulations are employed to validate this model, and the agreements of comparisons are favorable. The results show that the density of neutral gas decreases exponentially with the distance away from the dielectric surface. It is concluded that the gas diffusion is the main factor in the density reduction of neutral gas. With the influence of gas ionization, the number of electrons striking the dielectric surface increases. As a result, the gas pressure above the dielectric surface increases rapidly. In addition, the discharge formation time tc of microwave window breakdown decreases exponentially with the gas desorption rate. Besides, tc decreases with the energy of the first crossover point of the secondary electron emission curve when the strength of microwave electric field Erf is small. This dynamical model provides a solution to designing the microwave window.
A note on the uniqueness result for the inverse Henderson problem
Authors: Frommer F. , Hanke M. , Jansen S.
Published: September 2019

The inverse Henderson problem of statistical mechanics is the theoretical foundation for many bottom-up coarse-graining techniques for the numerical simulation of complex soft matter physics. This inverse problem concerns classical particles in continuous space which interact according to a pair potential depending on the distance of the particles. Roughly stated, it asks for the interaction potential given the equilibrium pair correlation function of the system. In 1974, Henderson proved that this potential is uniquely determined in a canonical ensemble and he claimed the same result for the thermodynamical limit of the physical system. Here, we provide a rigorous proof of a slightly more general version of the latter statement using Georgii’s variant of the Gibbs variational principle.
Negative thermal expansion behavior in orthorhombic Sc2(MoO4)3 and Sc2(WO4)3
Authors: Gupta Mayanak K. , Mittal Ranjan , Chaplot Samrath L.
Published: September 2019

In contrast to cubic ZrW2O8 and ZrMo2O8, which have isotropic negative thermal expansion, the compounds Sc2(WO4)3 and Sc2(MoO4)3 with the orthorhombic structure show anisotropic thermal expansion that is negative along the b and c axes. Using ab initio density functional theory calculations of lattice dynamics, we identify that the anisotropic expansion is not due to anisotropic elasticity or negative linear compressibility, which is the case in several compounds; instead, it is due to anisotropic Grüneisen parameters of specific phonons, mostly of energy around 6 meV. Such a behavior not involving anomalous elasticity is unusual. The phonon eigenvectors show that these phonons have a rather complex vibrational character of MoO4/WO4 and ScO6 polyhedral units that involve translational, librational, and internal distortion dynamics.
Lattice theory for binding of linear polymers to a solid substrate from polymer melts: I. Influence of chain connectivity on molecular binding and adsorption
Authors: Dudowicz Jacek , Douglas Jack F. , Freed Karl F.
Published: September 2019

Most theories of the binding of molecules to surfaces or for the association between molecules treat the binding species as structureless entities and neglect their rigidity and the changes in their stiffness induced by the binding process. The binding species are also taken to be “ideal,” meaning that the existence of van der Waals interactions and changes in these interactions upon molecular binding are also neglected. An understanding of the thermodynamics of these multifunctional molecular binding processes has recently come into focus in the context of the molecular binding of complex molecules, such as dendrimers and DNA grafted nanoparticles, to surfaces where the degree of binding cooperativity and selectivity, as well as the location of the binding transition, are found to be sensitive to the number of binding units constrained to a larger scale polymeric scaffold. We address the fundamental problem of molecular binding by extending classical Langmuir theory to describe the particular example of the reversible binding of semiflexible polymer chains to a solid substrate under melt conditions. The polymer chains are assumed to have a variable number N of binding units (segments) and to exhibit variable bending energies and van der Waals interactions in the bulk and on the surface, in addition to strong directional interactions with the surface. The resulting generalized Langmuir theory is applied to the examination of the influence of the chain connectivity of ideal polymers on the surface coverage Θ, transition binding temperature T1/2 at which Θ = 1/2, and on the derivative |dΘ/dT|T=T1/2 and the constant volume specific heat of binding, Cvbind, measures of the cooperativity and “sharpness” of the binding transition, respectively. Paper II is devoted to the impact of the van der Waals attractive interactions and chain stiffness on the reversible binding of nonideal polymer chains to a solid surface, including the enthalpy-entropy compensation phenomenon observed experimentally in many molecular and particle binding processes.
Radioactively driven colloids: A special case of anomalous diffusion
Authors: Wilson Graham , Bahadori Amir A. , Bindra Hitesh
Published: September 2019

A novel concept of self-propelled, radioactively driven colloids is introduced. The focus of this paper is on assessing the impact of alpha emissions on colloidal kinematics. Using Langevin dynamics and a random walk model, a theory has been developed to describe this motion. This theory shows a special case of anomalous diffusion. Numerical simulations have substantiated the theory. It is shown that alpha-particle emission can significantly affect the motion of colloidal particles, although a very short-lived radioisotope is required.
Meltblown technology for production of polymeric microfibers/nanofibers: A review
Authors: Drabek Jiri , Zatloukal Martin
Published: September 2019

This work summarizes the current state of knowledge in the area of meltblown technology for production of polymeric nonwovens with specific attention to utilized polymers, die design, production of nanofibers, the effect of process variables (such as the throughput rate, melt rheology, melt temperature, die temperature, air temperature/velocity/pressure, die-to-collector distance, and speed) with relation to nonwoven characteristics as well as to typical flow instabilities such as whipping, die drool, fiber breakup, melt spraying, flies, generation of small isolated spherical particles, shots, jam, and generation of nonuniform fiber diameters.
Mapping saddles and minima on free energy surfaces using multiple climbing strings
Authors: Shrivastav Gourav , Vanden-Eijnden Eric , Abrams Cameron F.
Published: September 2019

Locating saddle points on free energy surfaces is key in characterizing multistate transition events in complicated molecular-scale systems. Because these saddle points represent transition states, determining minimum free energy pathways to these saddles and measuring their free energies relative to their connected minima are further necessary, for instance, to estimate transition rates. In this work, we propose a new multistring version of the climbing string method in collective variables to locate all saddles and corresponding pathways on free energy surfaces. The method uses dynamic strings to locate saddles and static strings to keep a history of prior strings converged to saddles. Interaction of the dynamic strings with the static strings is used to avoid the convergence to already-identified saddles. Additionally, because the strings approximate curves in collective-variable space, and we can measure free energy along each curve, identification of any saddle’s two connected minima is guaranteed. We demonstrate this method to map the network of stationary points in the 2D and 4D free energy surfaces of alanine dipeptide and alanine tripeptide, respectively.
Sandwich-like space-coiling metasurfaces for weak-dispersion high-efficiency transmission
Authors: Tang Weipeng , Ren Chunyu , Tong Shuaishuai , Huang Xichun
Published: September 2019

Space-coiling metamaterials have attracted significant attention due to their large number of potential applications. However, their practical application faces various challenges because of the unavoidable wavefront distortions resulting from the strong dispersion or the low transmission efficiency resulting from the impedance mismatching. Here, we show that it is feasible to circumvent the problem via a sandwich-like unit, which contains one functional layer and four auxiliary layers and both of them can be constructed from the space-coiling structure. Therein, the functional layer is used to adjust the refractive index of the structure while the auxiliary layers ensure a gradual change of the impedance. We further utilize these units to construct acoustic metasurfaces for beam redirection and focusing. The numerical results demonstrated that a highly efficient and stable wavefront manipulation can be achieved over multiple frequency bands (2.5–4.0 kHz and 8.0–10.0 kHz).
Vibrational study in neon matrix of H2S-H2O, H2S-(H2O)2, and (H2S)2-H2O complexes. Identification of the two isomers: HOH-SH2 (H2O proton donor) and HSH-OH2 (H2S proton donor)
Authors: Soulard P. , Tremblay B.
Published: September 2019

For the first time, the investigation of water molecules complexed with hydrogen sulfide in solid neon was performed from 80 to 6000 cm−1 using Fourier transform infrared spectroscopy. In the first step, we identify the ν1 and ν3 frequencies of the proton donor in the H2S dimer. From concentration effects and with the help of theoretical results, we have highlighted the presence of the two stable isomers, HOH–SH2 where H2O is the proton donor and HSH–OH2 where H2S is the proton donor. We also identify several transitions for (H2S)2–H2O and H2S–(H2O)2 complexes, the first step of the microsolvation of H2S, and we propose structures for these complexes with the help of theoretical calculations at the second-order Møller-Plesset level.
Ultrafast spin dynamics and spintronics for ferrimagnets close to the spin compensation point (Review)
Authors: Ivanov B. A.
Published: September 2019

The possibilities of applying magnets with full or partial magnetic moment compensation in various spin groups to improve the performance of magnetic electronic devices using spin current (spintronics) are discussed. The effects of an exchange enhancement of the spin dynamics in antiferromagnets are well known. Over the past few years, antiferromagnetic spintronics has turned into an independent, rapidly developing field of applied physics of magnetism. This article provides for a detailed analysis of the possibility of using another class of magnetic materials, such as ferrimagnets close to the spin compensation point, in which the indicated acceleration effects are also detected. A comparative analysis of these two classes of magnets is conducted. The nonlinear spin dynamics of ferrimagnets are examined using a nonlinear sigma-model for the antiferromagnetic vector, describing the difference in spin densities of various spin groups. The simple conclusion derived based on this model is presented, and its real parameters for popular ferrimagnets, amorphous alloys of iron, and rare earth elements, are discussed. The different nonlinear effects of spin dynamics, ranging from homogeneous spin vibrations in small particles to the dynamics of solitons, domain walls, ferrimagnetic skyrmions, and vortices, are analyzed. The possibility of exciting such dynamic modes using spin torque, and their application in ultrafast spintronics is considered.
New trends in spectroscopy of solid nitrogen
Authors: Savchenko E. , Khyzhniy I. , Bondybey V.
Published: September 2019

This topical review presents new trends in emission spectroscopy of solid nitrogen. Developed approach to study of charged centers and their role in radiation-induced phenomena as well as relaxation processes is discussed. The emission spectroscopy elaborated incorporates correlated in real time detection of several relaxation emission—optical photons, electrons and emission of particles. Key details of this approach applied in research of pre-irradiated by electron beam solid nitrogen and nitrogen-helium nanoclusters grown by a gas jet condensation technique are given. New methods—nonstationary luminescence and nonstationary desorption, designed to study ion-electron recombination reactions—are briefly presented. The selected recent results obtained employing this approach and emission spectroscopy techniques to study the charge related phenomena in condensed nitrogen are summarized. Main attention is given to detection of polyatomic ionic centers containing four and three nitrogen atoms: N4+,N3+,N3−. Their part played in radiation-induced phenomena and relaxation processes, in particular desorption, is discussed.
Heat Transfer under Pulsed Heating in Superfluid Helium
Authors: Efimov V. B. , Оrlova A. A. , Kondaurova L. P. , Gorkun A. G.
Published: September 2019

An experimental study of the propagation of long (up to 1000 μs) heat pulses showed that for heat transfer, the formation of a vortex field near the heating medium on characteristic dimensions of the order of several millimetres is crucial, which blocks further backflow of the normal and superfluid components and development of turbulence in the entire waveguide volume.
Dynamics of Abrikosov’s Vortex Forced Oscillations: Role of Frequency, Acting Forces and Vortex Parameters
Authors: Rusakov V. F. , Chabanenko V. V. , Nabiałek A. , Chumak O. M. , Puźniak R.
Published: September 2019

The trajectories of motion of an isolated Abrikosov vortex in the anisotropic YBa2Cu3O7 superconductor under the influence of an external periodic force, damping into the sample, were constructed and analysed, taking into account the inert properties of the vortex and the forces acting on it: pinning, Lorentz, elasticity and viscosity. The hierarchy of the influence of various forces in a wide frequency range (∼1 THz) of the driving force on the shape and size of the trajectory is established. The calculated energy absorption by the vortex, as a function of frequency, taking into account the effective mass of the vortex, has resonant peaks: one at low frequency, associated with the de Gennes and Matricon mode, and the second at high frequency. The differences, manifested in vortex-induced oscillations for different field orientations in YBa2Cu3O7 and for the isotropic low-temperature superconductor NbTi, are analysed.
Magnetic and structural correlations in the warwickite Mn2OBO3
Authors: Gnezdilov V. , Pashkevich Yu. , Kurnosov V. , Zhuravlev O. V. , Wulferding D. , Lemmens P. , Kazak N. V. , Knyazev Yu. V. , Ovchinnikov S. G.
Published: September 2019

We report a Raman scattering study of single-crystalline homometallic oxyborate Mn2OBO3, a compound realizing a one-dimensional ribbon-structure. Phonon excitations as a function of temperature and light polarization are compared to lattice dynamical calculations, giving evidence for a strong coupling between lattice and magnetic degrees of freedom. Furthermore, a broader feature with a distinct structure emerges at low temperatures. Based on our theoretical analysis, we assign this signal to specific two-magnon scattering processes related to high energy flat-band magnon branches.
Spin-glass features at multiple temperatures and transport anomalies in Tb4PtAl
Authors: Kumar Ram , Iyer Kartik K. , Paulose P. L. , Sampathkumaran E. V.
Published: September 2019

The magnetic and electrical transport properties of Tb4PtAl, crystallizing in the Gd4RhIn-type cubic crystal structure characterized by three sites for the rare-earth, are reported by the measurements of magnetization, heat-capacity, and electrical resistivity (1.8–300 K). In comparison with the Gd analog, which has been shown to exhibit a complex magnetism with antiferromagnetism (TN = 64 K) entering into a spin-glass phase below 20 K, the spin-glass phase coexists at the onset of the antiferromagnetic order at 50 K in the Tb compound; additional spin-glass anomalies around 8 and 25 K are also found. Interestingly, the plot of electrical resistivity vs temperature develops a minimum in the presence of an external magnetic field above 50 K, and this transport behavior, unusual among rare-earth intermetallics, is presumably due to the gradual growth of short-range antiferromagnetic clusters as the long-range magnetic order develops.
Frequency domain modeling of quasielastic neutron scattering from hydrated protein powders: Application to free and inhibited human acetylcholinesterase
Authors: Saouessi Melek , Peters Judith , Kneller Gerald R.
Published: September 2019

This article reports on a frequency domain analysis of quasielastic neutron scattering spectra from free and Huperzine-A-inhibited human acetylcholinesterase, extending a recent time domain analysis of the same experimental data [M. Saouessi et al., J. Chem. Phys. 150, 161104 (2019)]. An important technical point here is the construction of a semianalytical model for the resolution-broadened dynamic structure factor that can be fitted to the experimental spectra. We find comparable parameters as in our previous study and demonstrate that our model is sensitive to subpercent changes in the experimental data, which are caused by reversible binding of the inhibitor Huperzine A.
Trio of improvements allows for fast, realistic molecular simulations of electrochemical systems
Authors: Patrick Chris
Published: September 2019

Removing three approximations from classical Density Functional Theory molecular simulations of processes in electrochemical devices improves accuracy without sacrificing speed.
A.E.Favorskii’s scientific legacy in modern organic chemistry: prototropic acetylene – allene isomerization and the acetylene zipper reaction
Authors: Danilkina Natalia A. , Vasileva Anna A. , Balova Irina A.
Published: September 2019

Alexei Evgrafovich Favorskii was an outstanding organic chemist who left a great scientific legacy as a result of long time and fruitful work. Most of the theoretically and practically important discoveries of A.E.Favorskii were made in the chemistry of acetylene and its derivatives. Nowadays, the reactions discovered by him, which include acetylene – allene isomerization, the Favorskii and retro-Favorskii reactions, the Favorskii rearrangement and the vinylation reaction, are widely used in industry and in laboratory synthesis. This review summarizes the main scientific achievements of A.E.Favorskii, as well as their development in modern organic chemistry. Much consideration is given to acetylene – allene isomerization as a convenient method for the synthesis of methyl-substituted acetylenes and to the acetylene zipper reaction as a synthetic tool for obtaining terminal acetylenes. The review presents examples of the application of these reactions in modern organic synthesis of complex molecules, including natural compounds and their analogues.

The bibliography includes 266 references.
Prey fish communities of the Laurentian Great Lakes: A cross-basin overview of status and trends based on bottom trawl surveys, 1978-2016
Authors: Gorman Owen T.
Published: September 2019

Annual bottom trawl surveys were initiated in the 1970s in Laurentian Great Lakes Superior, Huron, Michigan and Ontario and in 1990 in Erie to provide annual assessments of the status and trends of prey fish communities. Native Cisco Coregonus artedi and Bloater C. hoyi dominated the prey fish community of Lake Superior. Prey fish communities in lakes Huron and Michigan were dominated by nonnative Rainbow Smelt Osmerus mordax and Alewife Alosa pseudoharengus for much of 1978-2016, but Bloater was an important species during the 1980-1990s and more recently has become the dominant prey species in these lakes. Alewife dominated the prey fish community of Lake Ontario during all 1978-2016. While nonnatives dominated the prey fish community in Lake Erie, native Emerald Shiner Notropis atherinoides was an important species and occasionally the dominant prey fish after the establishment of Round Goby Neogobius melanostomus in the late 1990s. During the 1980s-1990s Bythotrephes cederstroemi, Dreissena polymorpha, and Dreissena bugensis caused profound changes in Laurentian Great Lakes ecosystems and likely contributed to declines in fish community biomass in lakes Michigan and Huron. The impacts of these invaders were more muted in lakes Erie and Ontario. Lake Superior stands out as the Laurentian Great Lakes success story: Lake Trout Salvelinus namaycush was restored, and native prey fishes dominate and support a viable fishery. Although the abundance of Bloater has increased recently in lakes Huron and Michigan, recovery of native prey fishes remains uncertain. The absence of native species among the principal prey fish in Lake Ontario indicates a lack of progress in native fish recovery. Recovery of native prey fishes remains unclear in Lake Erie. The ever-changing state of the Laurentian Great Lakes caused by the impacts of invasive species and ongoing climate and ecosystem change will continue to challenge restoration of native fish communities in the 21st Century.
Arbuscular mycorrhizal fungi in the rhizosphere soil of poisonous plants depressed the growth of pasture grasses in the Tibetan Plateau Alpine meadow
Authors: Wang Xiaojuan , Wang Qiang , Jin Liang , Sun Li , Wang Qian , Zhang Liang , Chen Yinglong
Published: September 2019

In order to explore the influence of arbuscular mycorrhizal (AM) fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem, rhizosphere soils were collected from eight different poisonous plants in degraded grasslands and one from pasture grass in non-degraded grasslands (CK). The collected soils were used as inocula to assess the influence of indigenous AM fungi on the growth of two typical pasture grass species, 
Elymus nutans
 and 
Poa pratensis
, in a bioassay experiment. Five growth parameters and two AM parameters were determined. The mycorrhizal responsiveness and the importance value were calculated. Significant differences between the eight poisonous plants and CK were observed. Compared to CK, rhizosphere soil from the eight poisonous plants had lower AM fungal spore densities. The growth of 
E. nutans
 and 
P. pratensis
 seedlings was depressed with the inoculation from poisonous plants rhizosphere soil. This study demonstrated that the presence of poisonous plants with grassland degradation altered inherent AM fungal community abundance, and could exert inhibition effects on the growth of pasture grasses. It may attribute to discover the important role of rhizosphere soil of different poisonous plants to AM fungal community on the Alpine meadow.
Voltage-clamp recordings of light responses from wild-type and mutant mouse cone photoreceptors
Authors: Ingram Norianne T. , Sampath Alapakkam P. , Fain Gordon L.
Published: September 2019

We describe the first extensive study of voltage-clamp current responses of cone photoreceptors in unlabeled, dark-adapted mouse retina using only the position and appearance of cone somata as a guide. Identification was confirmed from morphology after dye filling. Photocurrents recorded from wild-type mouse cones were biphasic with a fast cone component and a slower rod component. The rod component could be eliminated with dim background light and was not present in mouse lines lacking the rod transducin-α subunit (Gnat1−/−) or connexin 36 (Cx36−/−). Cones from Gnat1−/− or Cx36−/− mice had resting membrane potentials between −45 and −55 mV, peak photocurrents of 20–25 picoamps (pA) at a membrane potential Vm = −50 mV, sensitivities 60–70 times smaller than rods, and a total membrane capacitance two to four times greater than rods. The rate of activation (amplification constant) was largely independent of the brightness of the flash and was 1–2 s−2, less than half that of rods. The role of Ca2+-dependent transduction modulation was investigated by recording from cones in mice lacking rod transducin (Gnat1), recoverin, and/or the guanylyl-cyclase–activating proteins (GCAPs). In confirmation of previous results, responses of Gnat1−/−;Gcaps−/− cones and triple-mutant Gnat1−/−;Gcaps−/−;Rv−/− cones recovered more slowly both to light flashes and steps and were more sensitive than cones expressing the GCAPs. Cones from all four mouse lines showed significant recovery and escaped saturation even in bright background light. This recovery occurred too rapidly to be caused by pigment bleaching or metaII decay and appears to reflect some modulation of response inactivation in addition to those produced by recoverin and the GCAPs. Our experiments now make possible a more detailed understanding of the cellular physiology of mammalian cone photoreceptors and the role of conductances in the inner and outer segment in producing cone light responses.
Density and function of actin-microdomains in healthy and NF1 deficient osteoclasts revealed by the combined use of atomic force and stimulated emission depletion microscopy
Authors: Deguchi Takahiro , Fazeli Elnaz , Koho Sami , Pennanen Paula , Alanne Maria , Modi Mayank , Eriksson John E , Vienola Kari V , Hänninen Pekka E , Peltonen Juha , Näreoja Tuomas
Published: September 2019

Actin and myosins (IIA, IIB, and X) generate mechanical forces in osteoclasts that drive functions such as migration and membrane trafficking. In neurofibromatosis, these processes are perturbed due to a mutation in neurofibromatosis type 1 (NF1) gene. This mutation leads to generation of hyperactive bone-resorbing osteoclasts that increases incidence of skeletal dysplasia e.g. early-onset osteoporosis in patients suffering from neurofibromatosis. To study the density and function of actin clusters in mutated cells we introduce a new approach for combined use of a stimulated emission depletion (STED) microscope with an atomic force microscope (AFM). We resolved actin-cores within actin-microdomains at four typical structures (podosome-belt, podosome raft, actin patches, and sealing zone) for osteoclasts cultured on bone as well as on glass. Densities of actin-cores in these structures were higher on bone than on glass, and the nearest neighbor distances were shortest in sealing zones, where also an accumulation of vesicular material was observed at their center. In NF1 deficient osteoclasts, the clustering was tighter and there was also more vesicular material accumulated inside the sealing zone. Using the STED-AFM system, we measured the condensation of the actin structures in real-time after a bone-coated cantilever was placed in contact with a differentiated osteoclast and found that the condensation of actin was initiated at 40 min, after sufficient local actin concentration was reached. A functional implication of the less dense clustering in NF1 deficient cells was that the adhesion of these cells was less specific for bone. The data and new methodologies presented here build a foundation for establishing novel actomyosin dependent mechanisms during osteoclast migration and resorption.
Energy equalities for compressible Navier–Stokes equations
Authors: Nguyen Quoc-Hung , Nguyen Phuoc-Tai , Tang Bao Quoc
Published: September 2019

The energy equalities of compressible Navier–Stokes equations with general pressure law and degenerate viscosities are studied. By using a unified approach, we give sufficient conditions on the regularity of weak solutions for these equalities to hold. The method of proof is suitable for the case of periodic as well as homogeneous Dirichlet boundary conditions. In particular, by a careful analysis using the homogeneous Dirichlet boundary condition, no boundary layer assumptions are required when dealing with bounded domains with a boundary.
Probing phase transitions in a soft matter system using a single spin quantum sensor
Authors: Kavatamane Vinaya Kumar , Duan Dewen , Arumugam Sri Ranjini , Raatz Nicole , Pezzagna Sebastian , Meijer Jan , Balasubramanian Gopalakrishnan
Published: September 2019

Phase transitions in soft matter systems reveal some of the interesting structural phenomena at the levels of individual entities constituting those systems. The relevant energy scales in soft matter systems are comparable to thermal energy (k
B
T ∼ 10−21 J). This permits one to observe interesting structural dynamics even at ambient conditions. However, at the nanoscale most experimental probes currently being used to study these systems have been either plagued by low sensitivity or are invasive at molecular scales. Nitrogen-vacancy (NV) centers in diamond is emerging as a robust quantum probe for precision metrology of physical quantities (e.g. magnetic field, electric field, temperature, and stress). Here, we demonstrate by using NV sensors to probe spin-fluctuations and temperature simultaneously to obtain information about controlled phase changes in a soft matter material as a function of temperature. The soft matter system chosen for the study is a standard liquid crystalline (LC) material which shows distinct phases close to room temperature. Individual NV centers at depths of a few nm are used as a probe to detect magnetic signals emanating from a few molecular layers of sample on the surface of the diamond. The organization and collective dynamics of LC molecules in nanoscopic volumes are discussed. Our study aims to extend the areas of application of quantum sensing using NV centers to probe the soft matter systems, particularly those exhibiting mesophases and interesting interfacial properties.
A new kind of chaotic diffusion: anti-persistent random walks of explosive dissipative solitons
Authors: Albers Tony , Cisternas Jaime , Radons Günter
Published: September 2019

The solitons that exist in nonlinear dissipative media have properties very different from the ones that exist in conservative media and are modeled by the nonlinear Schrödinger equation. One of the surprising behaviors of dissipative solitons is the occurrence of explosions: sudden transient enlargements of a soliton, which as a result induce spatial shifts. In this work using the complex Ginzburg–Landau equation in one dimension, we address the long-time statistics of these apparently random shifts. We show that the motion of a soliton can be described as an anti-persistent random walk with a corresponding oscillatory decay of the velocity correlation function. We derive two simple statistical models, one in discrete and one in continuous time, which explain the observed behavior. Our statistical analysis benchmarks a future microscopic theory of the origin of this new kind of chaotic diffusion.
Enhanced heating rate of black carbon above the planetary boundary layer over megacities in summertime
Authors: Liu Dantong , Zhao Delong , Xie Zhenzhen , Yu Chenjie , Chen Ying , Tian Ping , Ding Shuo , Hu Kang , Lowe Douglas , Liu Quan , Zhou Wei , Wang Fei , Sheng Jiujiang , Kong Shaofei , Hu Dawei , Wang Zhenzhu , Huang Mengyu , Ding Deping
Published: September 2019

The fast development of a secondary aerosol layer was observed over megacities in eastern Asia during summertime. Within three hours, from midday to early afternoon, the contribution of secondary aerosols above the planetary boundary layer (PBL) increased by a factor of three to five, and the coatings on black carbon (BC) also increased and enhanced its absorption efficiency by 50%. This tended to result from the intensive actinic flux received above the PBL which promoted photochemical reactions. The absorption of BC could be further amplified by the strong reflection of solar radiation over the cloud top across the PBL. This enhanced heating effect of BC introduced by combined processes (intensive solar radiation, secondary formation and cloud reflection) may considerably increase the temperature inversion above the PBL. This mechanism should be considered when evaluating the radiative impact of BC, especially for polluted regions receiving strong solar radiation.
Effect of pharmacist-led task force to reduce opioid prescribing in the emergency department
Authors: Acquisto Nicole M , Schult Rachel F , Sarnoski-Roberts Sandra , Wilmarth Jaclyn , Jones Courtney M C , McCann Molly , Dolce Rebecca , Stott Rebecca , Noble Marcy , Davis Colleen , Springer Heidi , Kamali Michael F , Miglani Aekta
Published: September 2019

Purpose

Results of a study to determine the effect of a pharmacist-led opioid task force on emergency department (ED) opioid use and discharge prescriptions are presented.

Methods

An observational evaluation was conducted at a large tertiary care center (ED volume of 115,000 visits per year) to evaluate selected opioid use outcomes before and after implementation of an ED opioid reduction program by interdisciplinary task force of pharmacists, physicians, and nurses. Volumes of ED opioid orders and discharge prescriptions were evaluated over the entire 25-month study period and during designated 1-month preimplementation and postimplementation periods (January 2017 and January 2018). Opioid order trends were evaluated using linear regression analysis and further investigated with an interrupted time series analysis to determine the immediate and sustained effects of the program.

Results

From January 2017 to January 2018, ED opioid orders were reduced by 63.5% and discharge prescriptions by 55.8% from preimplementation levels: from 246.8 to 90.1 orders and from 85.3 to 37.7 prescriptions per 1,000 patient visits, respectively. Over the entire study period, there were significant decreases in both opioid orders (β, –78.4; 95% confidence interval [CI], –88.0 to –68.9; R2, 0.93; p < 0.0001) and ED discharge prescriptions (β, –24.4; 95% CI, –27.9 to –20.9; R2, 0.90; p < 0.001). The efforts of the task force had an immediate effect on opioid prescribing practices; results for effect sustainability were mixed.

Conclusion

A clinical pharmacist–led opioid reduction program in the ED was demonstrated to have positive results, with a more than 50% reduction in both ED opioid orders and discharge prescriptions.
Recording of Children and Young People’s Views in Contact Decision-Making
Authors: Porter Robert B
Published: September 2019

Children and young people have a right for their views to be heard and considered in decisions affecting their welfare. Fulfilment of this right may be evidenced through views being represented in documents related to the decision. This article reports findings of a study which examined the records of 160 children who were looked after in Scotland from 2013 to 2017. This included 1,200 individual Hearings, which made a total of 2,003 contact decisions. Data on contact decisions, views, and recommendations were extracted and analysed. Clear wishes of children are recorded in relation to just 12 per cent of contact decisions, and there is no recording of views in 64 per cent of contact decisions. Where the child is aged over twelve years, these figures rise to clear views being recorded in 22 per cent of contact decisions, with no recording of views in 42 per cent of contact decisions. These findings are concerning in relation to the value placed on the views of children and young people in decisions affecting their lives. There are implications for the information available to decision makers, social work practice and for policy and research relating to engagement and participation of children and young people in decisions affecting their lives.