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Estha J Schmidlin, Maryna Steyn, Tobias M R Houlton, Nanette Briers
Knowledge of facial ageing is important in forensic facial approximation and photo identification. Previous studies mostly investigated facial ageing in European faces, and this research therefore aims to provide data on patterns of facial ageing in an African sample. One hundred eighty-nine black South African males aged 20 years and older were photographed in anterior and lateral views. Facial images were captured in a consistent position by using a Canon EOS 1300D camera and 18- to 55-mm EFS lens. Thirty individuals per decade were included, with the 80+ age category being limited to only nine participants...
May 18, 2018: Forensic Science International
Eric J Bylaska, Kevin M Rosso
An approach for modeling electron transfer in solids and at surfaces of iron - (oxyhydr)oxides and other redox active solids has been developed for electronic structure methods (i.e., plane-wave Density Functional Theory) capable of performing calculations with periodic cells and large system sizes efficiently while at the same time being accurate enough to be used in the estimation of the electron-transfer coupling matrix element, $V_{AB}$, and the electron transfer transmission factor, $\kappa_{el}$. This method is an extension of the valence bond theory electron transfer method for molecules and clusters, implemented by Dupuis and others and used extensively by Rosso and co-workers, in which scaled corresponding orbitals derived from the Bloch states are used to calculate the off-diagonal matrix elements $H_{AB}$ and $S_{AB}$...
June 18, 2018: Journal of Chemical Theory and Computation
Maida Vartanian, Pilar de la Cruz, Subhayan Biswas, Ganesh D Sharma, Fernando Langa
In an effort to improve the short-circuit current and fill factor, organic solar cells have been developed with ternary blending in a single bulk heterojunction active layer. We report here several all small molecule organic solar cells based on ternary bulk heterojunction active layers. These layers consist of two small molecule porphyrin donors (MV71 and MV72), which have the same backbone but different end-capping acceptor units, and PC71BM as the acceptor. The organic solar cells showed overall power conversion efficiencies of 3...
June 18, 2018: Nanoscale
Liang Chen, Wei-Wei Zhao, Rong-Sheng Han
In this work, we investigate the local density of states (LDOS) near a magnetic impurity in single-layer FeSe superconductors. The two-orbital model with spin-orbit coupling proposed in Ref. [Phys. Rev. Lett. 119, 267001 (2017)] is used to describe the FeSe superconductor. In the strong coupling regime, two impurity resonance peaks appear with opposite resonance energies in the LDOS spectral function. For a strong spin-orbit coupling, the superconducting gap in this model is d-wave symmetric with nodes, the spatial distributions of the LDOS at the two resonance energies are fourfold symmetric, which reveals typical characteristic of d-wave pairing...
June 18, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Agustin Schiffrin, Martina Capsoni, Gelareh Farahi, Chen-Guang Wang, Cornelius Krull, Marina Castelli, Tanya Roussy, Katherine A Cochrane, Yuefeng Yin, Nikhil V Medhekar, Michael Fuhrer, Adam Q Shaw, Wei Ji, Sarah A Burke
Supramolecular chemistry protocols applied on surfaces offer compelling avenues for atomic-scale control over organic-inorganic interface structures. In this approach, adsorbate-surface interactions and two-dimensional confinement can lead to morphologies and properties that differ dramatically from those achieved via conventional synthetic approaches. Here, we describe the bottom-up, on-surface synthesis of one-dimensional coordination nanostructures based on an iron (Fe)-terpyridine (tpy) interaction borrowed from functional metal-organic complexes used in photovoltaic and catalytic applications...
June 18, 2018: ACS Nano
Longfei Li, Ming Lei, Yaoming Xie, Frank Weinhold, Henry F Schaefer
A substituted divinylborinium cation was synthesized recently and characterized crystallographically as a gauche structure with a 153° C1-C2-C3-C4 dihedral angle. A full theoretical geometrical optimization of the bis(2-mesityl-1,2-diphenylvinyl)-borane cation shows excellent agreement with the crystal structure. However, for the parent unsubstituted divinylborinium cation, we predict a nearly 90° C1-C2-C3-C4 dihedral angle using the CCSD(T)/cc-pVTZ coupled cluster method. The cis and trans planar geometries (0° and 180° for the C1-C2-C3-C4 dihedral angle) proved to be transition states with energy barriers of 2...
June 18, 2018: Inorganic Chemistry
Ana D P Silveira, Alexandre C R Gomes, Breno R L Galvão
The geometry and stability of aluminum-silicon alloys up to 13 atoms are investigated using electronic structure methods. The results agree well with available experimental data, while also predicting new potential candidates for detection. The exploration of the potential energy hypersurface of such particles is performed using both a thorough assessment of permutational isomers from selected structures and also using an unbiased genetic algorithm. It is shown that both approaches attain similar results for the specific cases analysed here...
June 18, 2018: Physical Chemistry Chemical Physics: PCCP
David M Engelhard, Andreas Meyer, Andreas Berndhäuser, Olav Schiemann, Guido H Clever
Artificial metal-base tetrads composed of square-planar CuII(pyridine)4 complexes were covalently attached to both the 3' and 5' ends of tetramolecular DNA G-quadruplexes [Ld(G3-5)LdT]4 (L = pyridine ligand) of different lengths. Owing to the planar four-point attachment of the metal complexes, the magnetic orbitals (dx2-y2) of the d9-configured CuII cations are placed in a coplanar fashion, separated by the stacked guanine tetrads. Pulsed EPR-derived CuII-CuII distances and angles were found to be in agreement with those obtained from molecular dynamics simulations...
June 18, 2018: Chemical Communications: Chem Comm
Jie Yang, Mohammad Afsar Uddin, Yumin Tang, Yulun Wang, Yang Wang, Huimin Su, Rutian Gao, Zhi-Kuan Chen, Junfeng Dai, Han Young Woo, Xugang Guo
We present here a series of wide band gap (Eg: > 1.8 eV) polymer donors by incorporating thiophene-flanked phenylene as electron-donating unit and quinoxaline as electron-accepting co-unit to attain large open-circuit voltages (Vocs) and short-circuit currents (Jscs) in non-fullerene organic solar cells (OSCs). Fluorination was utilized to fine-tailor the energetics of polymer frontier molecular orbitals (FMOs) by replacing a variable number of H atoms on the phenylene moiety with F. It was found that fluorination can effectively modulate polymer backbone planarity through intramolecular noncovalent S…F and/or H…F interactions...
June 18, 2018: ACS Applied Materials & Interfaces
Xugang Guo, Jianhua Chen, Kun Yang, Xin Zhou
The fusion of heteroaromatic rings into ladder-type heteroarenes can stabilize frontier molecular orbitals and lead to improved physicochemical properties, which are beneficial for applications in various optoelectronic devices. Hence, ladder-type heteroarenes, which feature highly planar backbones and well delocalized π-conjugation, recently have emerged as a type of promising organic semiconductors with excellent device performance in organic photovoltaics and organic field-effect transistors. In this Focus Review, we summarize the recent advances in ladder-type heteroarenes based organic semiconductors including hole-transporting and electron-transporting molecular semiconductors as well as fully ladder-type conjugated polymers towards their applications in organic photovoltaics and field-effect transistor...
June 17, 2018: Chemistry, An Asian Journal
Takashi Yamada, Mariko Kinoshita, Kento Araragi, Yu Watanabe, Takahiro Ueba, Hiroyuki S Kato, Toshiaki Munakata
Spectroscopic and nanoscale imaging investigations concerning the spatial extent of molecular orbitals at organic/substrate interfaces have been of intense interest to understand charge dynamics. Here, the spatial extent of unoccupied molecular orbitals of ultrathin rubrene [5,6,11,12-tetraphenyltetracene] films has been investigated with scanning tunneling microscopy and spectroscopy. Based on constant-current distance (z)-voltage (V) measurements, the unoccupied energy levels are elucidated and found to be consistent with previously reported macroscopic two-photon photoemission (2PPE) spectroscopy...
June 18, 2018: Physical Chemistry Chemical Physics: PCCP
Arnar Hafliðason, Pavle Glodic, Greta Koumarianou, Peter C Samartzis, Ágúst Kvaran
The multiphoton dynamics of CH3Br were probed by Mass Resolved MultiPhoton Ionization (MR-MPI), Slice Imaging and Photoelectron Imaging in the two-photon excitation region of 66 000 to 80 000 cm-1. Slice images of the CH3+ and Br+ photoproducts of ten two-photon resonant transitions to np and nd Rydberg states of the parent molecule were recorded. CH3+ ions dominate the mass spectra. Kinetic energy release spectra (KERs) were derived from slice and photoelectron images and anisotropy parameters were extracted from the angular distributions of the ions to identify the processes and the dynamics involved...
June 18, 2018: Physical Chemistry Chemical Physics: PCCP
Jiao Li, Xujun Duan, Qian Cui, Huafu Chen, Wei Liao
BACKGROUND: Major depressive disorder (MDD) is associated with high risk of suicide. Conventional neuroimaging works showed abnormalities of static brain activity and connectivity in MDD with suicidal ideation (SI). However, little is known regarding alterations of brain dynamics. More broadly, it remains unclear whether temporal dynamics of the brain activity could predict the prognosis of SI. METHODS: We included MDD patients (n = 48) with and without SI and age-, gender-, and education-matched healthy controls (n = 30) who underwent resting-state functional magnetic resonance imaging...
June 18, 2018: Psychological Medicine
Travis E Baker, Natalie Castellanos-Ryan, Gunter Schumann, Anna Cattrell, Herta Flor, Frauke Nees, Tobias Banaschewski, Arun Bokde, Rob Whelan, Christian Buechel, Uli Bromberg, Dimitri Papadopoulos Orfanos, Juergen Gallinat, Hugh Garavan, Andreas Heinz, Henrik Walter, Rüdiger Brühl, Penny Gowland, Tomáš Paus, Luise Poustka, Jean-Luc Martinot, Herve Lemaitre, Eric Artiges, Marie-Laure Paillère Martinot, Michael N Smolka, Patricia Conrod
BACKGROUND: Abnormalities in reward circuit function are considered a core feature of addiction. Yet, it is still largely unknown whether these abnormalities stem from chronic drug use, a genetic predisposition, or both. METHODS: In the present study, we investigated this issue using a large sample of adolescent children by applying structural equation modeling to examine the effects of several dopaminergic polymorphisms of the D1 and D2 receptor type on the reward function of the ventral striatum (VS) and orbital frontal cortex (OFC), and whether this relationship predicted the propensity to engage in early alcohol misuse behaviors at 14 years of age and again at 16 years of age...
June 18, 2018: Psychological Medicine
A Bashyam, A Stewart, K Potter, I Bagwan, V S Sunkaraneni
Endometrial carcinoma is the fourth most common cancer affecting women in the UK. Its most frequent sites of spread are to the pelvic and para-aortic lymph nodes, vagina and peritoneum. We report a case of a 63-year-old woman with known endometrial cancer who presented with left facial swelling and eye displacement. Investigations revealed an expansile soft-tissue density mass arising within the bone, centred on the left zygoma, with exophytic extension into the left maxillary antrum, infratemporal fossa and inferiorly into the orbit...
June 18, 2018: Annals of the Royal College of Surgeons of England
Rui Peng, Yandong Ma, Shuai Zhang, Baibiao Huang, Ying Dai
Two-dimensional valleytronic systems can provide information storage and processing advantages that complement or surpass those of conventional charge- and spin-based semiconductor technologies. The major challenge currently is to realize valley polarization for manipulating the valley degree of freedom. Here, we propose that valley polarization can be readily achieved in Janus single-layer MoSSe through magnetic doping, which is highly feasible in experiment. Due to inversion symmetry breaking combined with strong spin-orbit coupling (SOC), the pure single-layer MoSSe harbors an intriguing multivalleyed band structure and strong coupled spin and valley physics...
June 19, 2018: Journal of Physical Chemistry Letters
Zohreh Parsaee, Nima Karachi, Razieh Razavi
This work introduces novel selective and sensitive optical sensor based on a nano sized triazine based Schiff base (H2 L) immbolized on a transparent glass substrate through the sol-gel process to detection of copper (II) ions in aqueous solutions. This sensor can determine the copper (II) in the range of 8.54 × 10-8 -1.0 × 10-5  mol L-1 with a low detection limit of 1.53 × 10-8  mol L-1 . The optimized geometry of H2 L and its copper complex was obtained based on DFT/B3LYP levels of theory with B3LYP/6-311 + G(d,p) and LANL2DZ/6-311 + G(d,p) basis sets respectively...
October 2018: Ultrasonics Sonochemistry
Qiuju Yin, Yujie Chen, Meng Zhou, Xiangsheng Jiang, Junjun Wu, Yang Sun
In order to improve the metabolism of pirfenidone (5-methyl-1-phenylpyridin-2-one, PFD), the methyl-deuterated version of pirfenidone via the substitution of hydrogen (H) at C-5 by its isotope deuterium (D, 5D-PFD) was synthesized and its photophysical properties were investigated. The negative solvatochrom was observed in absorption and fluorescence spectra with increasing solvent polarity, which implied that intermolecular charge transfer (ICT) involved n → π* transition for both of PFD and 5D-PFD...
June 7, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Andrea Grandoch, Matthias Kreppel, Ali-Farid Safi, Matthias Zirk, Joachim E Zöller
PURPOSE: Fractures of the orbital floor and orbital rim are frequently treated in maxillofacial departments. Various approaches to the orbital floor are described in the literature. We present an investigation of a modified subciliary approach (laterocaudal approach) with respect to its feasibility and clinical outcome. MATERIALS AND METHODS: Our retrospective study investigated 130 well-documented cases of patients with orbital floor fractures who received surgical reconstruction using a laterocaudal approach, and compared the results with the current literature, with a focus on subciliary and transconjunctival approaches...
April 18, 2018: Journal of Cranio-maxillo-facial Surgery
Taichi Kosugi, Hirofumi Nishi, Yoritaka Furukawa, Yu-Ichiro Matsushita
We demonstrate in the present study that self-consistent calculations based on the self-energy functional theory (SFT) are possible for the electronic structure of realistic systems in the context of quantum chemistry. We describe the procedure of a self-consistent SFT calculation in detail and perform the calculations for isolated 3d transition metal atoms from V to Cu as a preliminary study. We compare the one-particle Green's functions obtained in this way and those obtained from the coupled-cluster singles and doubles method...
June 14, 2018: Journal of Chemical Physics
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