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Wenbin Shao, Jun Huang, Kai Guo, Jianxian Gong, Zhen Yang
The total synthesis of naturally occurring (±)-sinensilactam A was achieved in 18 steps. The key steps of this work are a rhodium-catalyzed [3 + 2] cycloaddition for construction of the two all-carbon vicinal quaternary centers and a convergent and tandem condensation of the in situ generated N-acyliminium intermediate with aldehyde 20. This enabled implementation of a unified strategy for stereoselective formation of the tetracyclic hemiaminal core of sinensilactam A in a later stage. The total syntheses of applanatumol F and C8- epi-applanatumol D are also achieved using this strategy...
March 19, 2018: Organic Letters
Clifford E Kashtan, Jie Ding, Guido Garosi, Laurence Heidet, Laura Massella, Koichi Nakanishi, Kandai Nozu, Alessandra Renieri, Michelle Rheault, Fang Wang, Oliver Gross
Mutations in the genes COL4A3, COL4A4, and COL4A5 affect the synthesis, assembly, deposition, or function of the collagen IV α345 molecule, the major collagenous constituent of the mature mammalian glomerular basement membrane. These mutations are associated with a spectrum of nephropathy, from microscopic hematuria to progressive renal disease leading to ESRD, and with extrarenal manifestations such as sensorineural deafness and ocular anomalies. The existing nomenclature for these conditions is confusing and can delay institution of appropriate nephroprotective therapy...
March 15, 2018: Kidney International
Elissa S Epel, Alexandra D Crosswell, Stefanie E Mayer, Aric A Prather, George M Slavich, Eli Puterman, Wendy Berry Mendes
Stress can influence health throughout the lifespan, yet there is little agreement about what types and aspects of stress matter most for human health and disease. This is in part because "stress" is not a monolithic concept but rather, an emergent process that involves interactions between individual and environmental factors, historical and current events, allostatic states, and psychological and physiological reactivity. Many of these processes has alone been labeled as "stress." Stress science would be further advanced if researchers adopted a common conceptual model that incorporates epidemiological, affective, and psychophysiological perspectives, with more precise language for describing stress measures...
March 15, 2018: Frontiers in Neuroendocrinology
Ravi Kant, Aida Llauró, Vamseedhar Rayaprolu, Shefah Qazi, Pedro J de Pablo, Trevor Douglas, Brian Bothner
The capsid of P22 bacteriophage undergoes a series of structural transitions during maturation that guide it from spherical to icosahedral morphology. The transitions include the release of scaffold proteins and capsid expansion. Although P22 maturation has been investigated for decades, a unified model that incorporates thermodynamic and biophysical analyses is not available. A general and specific model of icosahedral capsid maturation are of significant interest to theoreticians searching for fundamental principles as well as virologists and material scientists seeking to alter maturation to their advantage...
March 14, 2018: Biochimica et Biophysica Acta
Marie Mardal, Petur Weihe Dalsgaard, Bing Qi, Christian Brinch Mollerup, Pieter Annaert, Kristian Linnet
The main analytical targets of synthetic cannabinoids are often metabolites. With the high number of new psychoactive substances entering the market, suitable workflows are needed for analytical target identification in biological samples. The aims of this study were to identify the main metabolites of the synthetic cannabinoids, AMB-CHMICA and 5C-AKB48, using an in silico-assisted workflow with analytical data acquired using ultra-high-performance liquid chromatography-(ion mobility spectroscopy)-high resolution-mass spectrometry in data-independent acquisition mode (UHPLC-(IMS)-HR-MSE )...
March 10, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Olga M Pavlova, Sergey O Ryabykh, Alexander V Burcev, Alexander V Gubin
STUDY DESIGN: Case series, level 4 of evidence. OBJECTIVES: To analyze clinical and radiological features of pathological atlantoaxial displacement (PAAD) in pediatric patients. To compose treatment algorithm for anomaly-related PAAD. SUMMARY OF BACKGROUND DATA: Criteria of different types of PAAD and treatment algorithms have been widely reported in the literature, but difficulty applicable in patients with odontoid abnormalities, C2-C3 block, spina bifida C1 and children...
March 13, 2018: World Neurosurgery
Andrew T Fenley, Ramu Anandakrishnan, Yared H Kidane, Alexey V Onufriev
BACKGROUND: Controlled modulation of nucleosomal DNA accessibility via post-translational modifications (PTM) is a critical component to many cellular functions. Charge-altering PTMs in the globular histone core-including acetylation, phosphorylation, crotonylation, propionylation, butyrylation, formylation, and citrullination-can alter the strong electrostatic interactions between the oppositely charged nucleosomal DNA and the histone proteins and thus modulate accessibility of the nucleosomal DNA, affecting processes that depend on access to the genetic information, such as transcription...
March 16, 2018: Epigenetics & Chromatin
Alexandre P Solon, Joakim Stenhammar, Michael E Cates, Yariv Kafri, Julien Tailleur
Motility-induced phase separation (MIPS) arises generically in fluids of self-propelled particles when interactions lead to a kinetic slowdown at high densities. Starting from a continuum description of scalar active matter akin to a generalized Cahn-Hilliard equation, we give a general prescription for the mean densities of coexisting phases in flux-free steady states that amounts, at a hydrodynamics scale, to extremizing an effective free energy. We illustrate our approach on two well-known models: self-propelled particles interacting either through a density-dependent propulsion speed or via direct pairwise forces...
February 2018: Physical Review. E
Chen Wu, Baochang Shi, Chang Shu, Zhen Chen
An efficient third-order discrete unified gas kinetic scheme (DUGKS) is presented in this paper for simulating continuum and rarefied flows. By employing a two-stage time-stepping scheme and the high-order DUGKS flux reconstruction strategy, third order of accuracy in both time and space can be achieved in the present method. It is also analytically proven that the second-order DUGKS is a special case of the present method. Compared with the high-order lattice Boltzmann equation-based methods, the present method is capable to deal with the rarefied flows by adopting the Newton-Cotes quadrature to approximate the integrals of moments...
February 2018: Physical Review. E
Guillaume St-Onge, Jean-Gabriel Young, Edward Laurence, Charles Murphy, Louis J Dubé
We present a degree-based theoretical framework to study the susceptible-infected-susceptible (SIS) dynamics on time-varying (rewired) configuration model networks. Using this framework on a given degree distribution, we provide a detailed analysis of the stationary state using the rewiring rate to explore the whole range of the time variation of the structure relative to that of the SIS process. This analysis is suitable for the characterization of the phase transition and leads to three main contributions: (1) We obtain a self-consistent expression for the absorbing-state threshold, able to capture both collective and hub activation...
February 2018: Physical Review. E
Julian Gonzalez-Ayala, A Medina, J M M Roco, A Calvo Hernández
The connection between Carnot-like and low-dissipation refrigerators is proposed by means of their entropy generation and the optimization of two unified, compromise-based figures of merit. Their optimization shows that only a limited set of heat transfer laws in the Carnot-like model are compatible with the results stemming from the low-dissipation approximation, even though there is an agreement of the related physical spaces of variables. A comparison between two operation regimes and relations among entropy generation, efficiency, cooling power...
February 2018: Physical Review. E
X Bai, B Tie, J-H Schmitt, D Aubry
The correlation between ultrasonic wave propagation and polycrystalline microstructures has significant implications in nondestructive evaluation. An original numerical approach using the finite element method to quantify in both time and frequency domains the ultrasonic noise scattering due to the elastic heterogeneity of polycrystalline microstructures is presented. Based on the reciprocity theorem, it allows the scattering evaluation using mechanical data recorded only on the boundary of polycrystal instead of within its volume and is applicable to any polycrystalline aggregate regardless of its crystallographic or morphological characteristics...
February 14, 2018: Ultrasonics
Tsinsue Chen, Zaman Mirzadeh, Kristina M Chapple, Margaret Lambert, Holly A Shill, Guillermo Moguel-Cobos, Alexander I Tröster, Rohit Dhall, Francisco A Ponce
OBJECTIVE Recent studies have shown similar clinical outcomes between Parkinson disease (PD) patients treated with deep brain stimulation (DBS) under general anesthesia without microelectrode recording (MER), so-called "asleep" DBS, and historical cohorts undergoing "awake" DBS with MER guidance. However, few studies include internal controls. This study aims to compare clinical outcomes after globus pallidus internus (GPi) and subthalamic nucleus (STN) DBS using awake and asleep techniques at a single institution...
March 16, 2018: Journal of Neurosurgery
Yan Zheng, Tetsuro Muraoka, Kento Nakagawa, Kouki Kato, Kazuyuki Kanosue
The relative-salience hypothesis has been proposed as a possible explanation for the stability of bimanual coordination. This explanation proceeds from a psychological viewpoint and is based on the following tenets: (1) cyclic joint motions involving two movements are conceived of as a unified event, (2) if a "single" point in each movement is seen as the most salient, the salient points of the two movements prefer to go together, and (3) in other cases, a unified event will be constrained by movement direction...
March 15, 2018: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Ying Han, Zhenyu Lu, Zhenguang Du, Qi Luo, Sheng Chen
BACKGROUND AND OBJECTIVE: Bipolar disorder is often mis-diagnosed as unipolar depression in the clinical diagnosis. The main reason is that, different from other diseases, bipolarity is the norm rather than exception in bipolar disorder diagnosis. YinYang bipolar fuzzy set captures bipolarity and has been successfully used to construct a unified inference mathematical modeling method to bipolar disorder clinical diagnosis. Nevertheless, symptoms and their interrelationships are not considered in the existing method, circumventing its ability to describe complexity of bipolar disorder...
May 2018: Computer Methods and Programs in Biomedicine
Ana Carolina Lima Cavaletti, Célia Pereira Caldas, Kenio Costa de Lima
OBJECTIVES: To identify the diseases that lead older persons to hospitalizations in the public health system in the state of Rio de Janeiro and, through a study of spatial distribution among hospitalization rates of the municipal districts, discuss the social contexts involved in the hospitalization of the elderly. METHODS: An ecological cross-sectional study using secondary data from the Brazilian hospital information system from the period 2009 to 2015 was performed...
March 12, 2018: Value in Health Regional Issues
Wei Wang, Yan Yan, Feiping Nie, Shuicheng Yan, Nicu Sebe
Graph-based dimensionality reduction techniques have been widely and successfully applied to clustering and classification tasks. The basis of these algorithms is the constructed graph which dictates their performance. In general, the graph is defined by the input affinity matrix. However, the affinity matrix derived from the data is sometimes suboptimal for dimension reduction as the data used are very noisy. To address this issue, we propose the projective unsupervised flexible embedding models with optimal graph (PUFE-OG)...
June 2018: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Ting Cao, Meng Wu, Steven G Louie
We show that band topology can dramatically change the photophysics of two-dimensional semiconductors. For systems in which states near the band extrema are of multicomponent character, the spinors describing these components (pseudospins) can pick up nonzero winding numbers around the extremal k point. In these systems, we find that the strength and required light polarization of an excitonic optical transition are dictated by the optical matrix element winding number, a unique and heretofore unrecognized topological characteristic...
February 23, 2018: Physical Review Letters
Thai M Hoang, Rui Pan, Jonghoon Ahn, Jaehoon Bang, H T Quan, Tongcang Li
Nonequilibrium processes of small systems such as molecular machines are ubiquitous in biology, chemistry, and physics but are often challenging to comprehend. In the past two decades, several exact thermodynamic relations of nonequilibrium processes, collectively known as fluctuation theorems, have been discovered and provided critical insights. These fluctuation theorems are generalizations of the second law and can be unified by a differential fluctuation theorem. Here we perform the first experimental test of the differential fluctuation theorem using an optically levitated nanosphere in both underdamped and overdamped regimes and in both spatial and velocity spaces...
February 23, 2018: Physical Review Letters
Laura M Scorr, Michael R Silver, John Hanfelt, Elaine Sperin, Alan Freeman, H A Jinnah, Stewart A Factor
Oromandibular dystonia (OMD) causes involuntary movements of masticatory and lingual muscles impairing eating, speaking, and swallowing. Treatment options are limited. The objective of this study was to determine the safety and efficacy of abobotulinumtoxinA (aboBoNTA) in OMD. A dose-finding study (phase 1) followed by a single session, prospective, single-blind trial (phase 2) was carried out. OMD subjects were evaluated at baseline, 6 and 12 weeks. Muscles injected were tailored to individual symptoms using EMG guidance, but the aboBoNTA dose for each muscle was pre-specified based on phase 1 results...
March 14, 2018: Neurotherapeutics: the Journal of the American Society for Experimental NeuroTherapeutics
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