bluuebunny/crossref_metadata_2025 huggingface dataset:
Pure Endoscopic Excision of Parenchymal Brain Tumors: Feasibilty, Risks, Advantages and Realities - A Beginners Perspective
Authors: Budhiraja Manish , Pathak Ashis , Brar Harmandeep , Brar Rahat
Published: May 2020

Background Neuroendoscopy is gaining popularity and is reaching new realms. Young neurosurgeons are exploring the various possibilities associated with the use of neuroendoscopy. Neuroendoscopy in excision of parenchymal brain tumors is less explored, and young neurosurgeons should be aware of the realities. The present article is an approach to put forward the difficulties faced by a young neurosurgeon and the lessons learnt.

Objective To report the experience of surgical excision of parenchymal brain tumors, in selected cases, using pure endoscopic approach and to discuss its feasibility, technical benefits, risks and comparison with conventional microscopic excision.

Method Eight patients of variable age group with parenchymal brain tumors were operated upon by a single surgeon and followed up for a period varying from 6 months to 2 years. Data regarding operating time, illumination, clarity of the field, size of craniotomy, blood loss and course of recovery was evaluated. All of the tumors were resected using rigid high definition zero and 30° endoscope.

Results Out of eight cases, seven had lesions in the supratentorial and one in the infratentorial location. The age group ranged from 27 to 74 years old. Near to gross total resection was achieved in all except two cases. All of the patients recovered well without any significant morbidity or mortality. Hospital stay was reduced by 1 day on average.

Conclusion Excision of parenchymal brain tumors via pure endoscopic method is a safe and efficient procedure. Although there is an initial period of learning curve, it is not steep for those already practicing neuroendoscopy, but the approach has its advantages.
Treatment Outcomes for Periprosthetic Femoral Fractures in Cementless Press-Fit Total Hip Replacement
Authors: Monotti Isobel C. , Preston Christopher A. , Kidd Scott W.
Published: May 2020

Objective The aim of this study was to report outcomes in dogs with periprosthetic femoral fractures associated with a press-fit cementless femoral total hip replacement implant.

Materials and Methods Electronic medical records and digital radiographs were used to identify dogs with periprosthetic femoral fractures associated with press-fit cementless total hip replacement. Data collected included signalment, weight, time of fracture, cause of fracture, presence of intra-operative fissure, fracture type, repair technique, and clinical and radiographic outcomes. Long-term patient outcome was assessed by communication with owners or referring veterinarians.

Results Twenty-eight dogs with femoral fracture repair associated with cementless press-fit total hip replacement were identified. Eight of the fractures occurred intraoperatively and 20 occurred at a median of 2 days postoperatively. An oblique or spiral configuration was noted in 19 cases and 15 occurred at the distal end of the femoral stem (type B), with thirteen type B1, one type B2 and one type B3 fractures. Fractures were repaired with non-locking (18/28) or locking-plate fixation (10/28). Cerclage wire was applied around the plate and proximal bone segment in 17/28 dogs. Major complications occurred in 7/28 cases (five deep infection, two mechanical failures). Bone healing was noted in 21/23 cases, for which follow-up radiographic interpretation was available. Return to function was complete in 17 cases, acceptable in 8 cases and unacceptable in 3 cases.

Conclusions While cementless total hip replacement periprosthetic femoral fractures can be successfully repaired with lateral plate fixation, the risk of infection appears to be high.
Tuberculosis of Sphenoid Sinus: Report of Two Cases
Authors: Bhat Vadisha Srinivas , J. Samatha K. , T. Devika , P. Shrinath D. Kamath , Aroor Rajeshwary , B. Satheesh Kumar Bhandary
Published: May 2020

Isolated lesions of the sphenoid sinus are uncommon and difficult to diagnose. In the absence of characteristic clinical findings, the diagnosis of such lesions depends mainly on imaging. However, as radiological appearance cannot provide the clinician with a definite diagnosis, histopathological examination of the specimen is mandatory for the diagnosis. Endoscopic sinus surgery has been an excellent approach for diagnosis as well as treatment of isolated sphenoid sinus lesions. The disease can be effectively treated by antituberculosis treatment. We report two cases of tuberculosis involving the sphenoid sinus only.
Geometry of the set of synchronous quantum correlations
Authors: Russell Travis B.
Published: May 2020

We provide a complete geometric description of the set of synchronous quantum correlations for the three-experiment two-outcome scenario. We show that these correlations form a closed set. Moreover, every correlation in this set can be realized using projection valued measures on a Hilbert space of dimension no more than 16.
SAFIIRA: A heavy-ion multi-purpose irradiation facility in Brazil
Authors: Aguiar V. A. P. , Medina N. H. , Added N. , Macchione E. L. A. , Alberton S. G. , Leite A. R. , Aguirre F. R. , Ribas R. V. , Perego C. C. , Fagundes L. M. , Terassi J. C. , Brage J. A. P. , Simões R. F. , Morais O. B. , Almeida E. A. , Joaquim P. M. , Souza M. S. , Cecotte A. F. M. , Martins R. , Duarte J. G. , Scarduelli V. B. , Allegro P. R. P. , Escudeiro R. , Leistenschneider E. , Oliveira R. A. N. , Servelo W. A. , Silva M. T. , Sarmento V. E. , Carreira C. A. , Abreu J. C. , Silva S. C. , Santos H. C. , Rodrigues C. L. , Assis R. F. , Silva T. F. , Tabacniks M. H. , Joaquim A. S. , Minas J. H. P. , Kashinsky D. , Guazzelli M. A. , Seixas L. E. , Finco S. , Benevenutti F.
Published: May 2020

This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.
Impact of bilayered oxide stacks on the breakdown transients of metal–oxide–semiconductor devices: An experimental study
Authors: Pazos S. M. , Boyeras Baldomá S. , Aguirre F. L. , Krylov I. , Eizenberg M. , Palumbo F.
Published: May 2020

The role of the bilayered structure of the gate oxide on the dynamics of progressive breakdown is systematically studied on Au/Cr/HfO2/Al2O3/InGaAs metal–oxide–semiconductor stacks. Samples with bilayered oxides of 100 Å total thickness were fabricated using different Al2O3 interfacial layer thicknesses to investigate the effects of combining insulator materials with largely different electrical and thermal properties. The breakdown current growth rate dIBD/dt was captured by means of low and high bandwidth measurement setups, and the results were compared in the framework of an electromigration-based progressive breakdown model, originally derived for single-layered oxides. Experimental results show that as the interfacial layer is thicker, a clear increase is observed on the applied voltage required to obtain dIBD/dt values in the same range. However, this effect is not observed for thicknesses above 10 Å for the Al2O3 layer. This is linked to both the electrical stress distribution across the bilayered structure and to the thermal characteristics of Al2O3 that contribute to reduce the temperature of the breakdown spot. The progressive breakdown model is modified to account for these features, showing good agreement with experimental results, behavior that cannot be explained by the model considering one of the layers as already broken during progressive breakdown.
Gyrokinetic simulations for turbulent transport of multi-ion-species plasmas in helical systems
Authors: Nunami M. , Nakata M. , Toda S. , Sugama H.
Published: May 2020

The turbulent transport of magnetic confinement plasmas including multi-ion-particle-species in helical systems such as the Large Helical Device (LHD) [Takeiri et al., Nucl. Fusion 57, 102023 (2017)] and their plasma profile sensitivities are investigated by local flux-tube gyrokinetic simulations. In the multi-ion-species plasmas, while the heat transport of each particle species has slightly different sensitivity towards the plasma temperature gradients and the density gradients, there exist quite different dependencies in the particle transport on the radial gradient profiles of the plasma temperatures and densities between each particle species. Furthermore, in the LHD plasma with the carbon impurity hole structure [Ida et al., Plasma Phys. 16, 056111 (2009)], the turbulent particle transport flux of the impurity carbon ion remains radially inward-directed robustly within the wide ranges of radial gradient profiles of the plasma temperatures and densities.
Origin of high carrier concentration in amorphous wide-bandgap oxides: Role of disorder in defect formation and electron localization in In2O3−x
Authors: Medvedeva J. E. , Zhuravlev I. A. , Burris C. , Buchholz D. B. , Grayson M. , Chang R. P. H.
Published: May 2020

Structural disorder has been known to suppress carrier concentration and carrier mobility in common covalent semiconductors, such as silicon, by orders of magnitude. This is expected from a reduced overlap of the electron clouds on neighboring orbitals and the formation of localized tail states near the band edges caused by local distortions and lack of periodicity in the amorphous phase. In striking contrast to the covalent semiconductors, wide-bandgap oxides of post-transition metals with ionic bonding not only allow for crystalline-like electron mobility upon amorphization, but also exhibit two orders of magnitude higher carrier concentration in the disordered phase as compared to the crystalline oxide. Here, the results of computationally intensive ab initio molecular dynamics simulations, comprehensive structural analysis, and accurate density-functional calculations reveal complex interplay between local distortions, coordination, and long-range bond morphology and help establish the microscopic origin of carrier generation and transport across the crystalline–amorphous transition in In2O3−x. Departing from traditional oxygen vacancy in crystalline oxides, the derived structural descriptors help categorize “defects” in disordered ionic oxides, quantify the degree of the associated electron localization and binding energy, and determine their role in the resulting electronic and optical properties. The results will be instrumental in the development of next-generation transparent amorphous semiconductors with a combination of properties not achievable in Si-based architectures.
Low-loss, high-bandwidth fiber-to-chip coupling using capped adiabatic tapered fibers
Authors: Khan Saeed , Buckley Sonia M. , Chiles Jeff , Mirin Richard P. , Nam Sae Woo , Shainline Jeffrey M.
Published: May 2020

We demonstrate adiabatically tapered fibers terminating in sub-micron tips that are clad with a higher-index material for coupling to an on-chip waveguide. This cladding enables coupling to a high-index waveguide without losing light to the buried oxide. A technique to clad the tip of the tapered fiber with a higher-index polymer is introduced. Conventional tapered waveguides and forked tapered waveguide structures are investigated for coupling from the clad fiber to the on-chip waveguide. We find the forked waveguide facilitates alignment and packaging, while the conventional taper leads to higher bandwidth. The insertion loss from a fiber through a forked coupler to a sub-micron silicon nitride waveguide is 1.1 dB and the 3 dB bandwidth is 90 nm. The coupling loss in the packaged device is 1.3 dB. With a fiber coupled to a conventional tapered waveguide, the loss is 1.4 dB with a 3 dB bandwidth extending beyond the range of the measurement apparatus, estimated to exceed 250 nm.
Deep learning in heterogeneous materials: Targeting the thermo-mechanical response of unidirectional composites
Authors: Chen Qiang , Tu Wenqiong , Ma Meng
Published: May 2020

In this communication, a multi-task deep learning-driven homogenization scheme is proposed for predicting the effective thermomechanical response of unidirectional composites consisting of a random array of inhomogeneity. Toward this end, 40 000 repeating unit cells (RUCs) comprising an arbitrary number of locally irregular inclusions are generated over a wide range of fiber volume fractions. The finite-volume direct averaging micromechanics is then employed to evaluate the homogenized thermo-mechanical moduli of each RUC. Subsequently, a two-dimensional deep convolution neural network (CNN) is constructed as a surrogate model to extract the statistical correlations between the RUC geometrical information and the corresponding homogenized response. The RUC images together with their homogenized moduli are divided into two datasets in a ratio of 9:1 with the former part used for training the CNN model and the latter part used for verification. The results presented in this contribution demonstrate that the deep CNN predictions exhibit remarkable correlations with the theoretical values generated by the finite-volume micromechanics, with a maximum relative prediction error of less than 8%, providing good support for the data-based homogenization approach.
Surface temperature estimation in determined multi-wavelength pyrometry systems
Authors: Araújo António , Silva Rui
Published: May 2020

A multi-wavelength pyrometry model was derived using Wien’s law. The surface spectral emissivity was modeled as the exponential of a polynomial in wavelength with one free parameter less than the number of pyrometer wavelength channels, resulting in a determined system of linear equations. Multi-wavelength temperature outputs were simulated using values generated by different emissivity functions. Surface temperature estimates were computed using a simple linear model based on polynomial interpolation. Although the accuracy of temperature estimates was reasonably high for some emissivity-generating functions, for other functions, the accuracy of the estimates was unacceptably low. As an alternative, ridge regression, a statistical technique to solve ill-posed problems, was applied to determined multi-wavelength systems, resulting in a substantial increase in the accuracy of temperature estimates, especially for higher-order pyrometry systems: the estimation errors were observed to decrease about 52% when the number of channels increased from 3 to 20; the estimation errors were observed to decrease more than 65% when the number of channels increased from 2, using the simple linear model, to 20, using the ridge regression model. These results demonstrate the potential of using ridge regression to improve the accuracy of temperature estimation in multi-wavelength pyrometry systems.
A high-repetition-rate shock tube for transient absorption and laser-induced fluorescence studies of high-temperature chemical kinetics
Authors: Matsugi Akira
Published: May 2020

A newly constructed high-repetition-rate shock tube designed for kinetic studies of high-temperature reactions using spectroscopic methods is described. The instrument operates at a 0.2-Hz cycle rate with a high reproducibility of reaction conditions that permits extensive signal averaging to improve the quality of kinetic trace data. The density and temperature of the gas behind the reflected shock wave are examined by probing the product formation from reference reactions. Two types of experimental techniques are implemented: transient absorption spectroscopy and time-resolved laser-induced fluorescence. Both methods are shown to be suitable for kinetic measurements of elementary reactions, as illustrated by their application in thermal decomposition reactions of the benzyl radicals and trifluoromethane.
The nature of the chemical bonding in 5d transition-metal diatomic borides MB (M = Ir, Pt, Au)
Authors: Cheung Ling Fung , Kocheril G. Stephen , Czekner Joseph , Wang Lai-Sheng
Published: May 2020

Boron can form strong bonds with transition metals in diatomic metal borides (MB), but the nature of the chemical bonding has not been well understood. Recently, a quadruple bond was discovered in Rh≣B, consisting of two σ bonds formed between the Rh 4dz2 and B 2s/2p orbitals and two π bonds between the Rh 4dxz/4dyz and the B 2px/2py orbitals. The bonding between the 5d transition metals and boron is expected to be even stronger. Here, we report an investigation on the electronic structure and chemical bonding of the 5d transition metal diatomic borides (IrB, PtB, and AuB) using high-resolution photoelectron imaging on the corresponding anions (MB−) and theoretical calculations. Vibrationally resolved photoelectron spectra are obtained for all three anions, and the electron affinities are measured for IrB, PtB, and AuB to be 1.995(1), 2.153(3), and 0.877(6) eV, respectively. It is found that the weakly anti-bonding 3σ molecular orbital (mainly of M 6s and B sp characters) is singly occupied in IrB (3Δ) and PtB (2Σ+), resulting in a bond order of three and half for these two diatomic borides. The 3σ orbital is doubly occupied in AuB (1Σ+), giving rise to a weak triple bond. Despite the lower bond order, the bonding in IrB and PtB is only slightly weaker than that in RhB due to the more favorable interactions between the M 5d orbitals and the B sp orbitals.
Closed-form theoretical model of the secondary drop size in partial coalescence—Capturing pertinent timescales and viscous forces
Authors: Houssainy Sammy , Kabachek Sofya , Kavehpour H. P.
Published: May 2020

One of the most important outcomes of partial drop coalescence is the ratio of the secondary drop radius to the primary drop radius, known as the drop ratio, ri. This ratio is thought to be approximately constant and independent of physical parameters of the fluids involved. However, this study reveals that ambient fluid viscosity can alter the size of the secondary drop and the drop ratio consequently. Using scaling analysis, we derive a model that predicts the behavior of the drop ratio as a function of the Ohnesorge number, a dimensionless ratio of viscous to inertial forces. In addition, we present our experimental results of coalescing drops on a planar interface under the influence of surface tension gradients. A high-speed digital camera is used to observe the evolution of drops as they coalesce with a bulk liquid. We show that this process is influenced by the surface tension gradient between the drop and the bulk liquid. The ratio of the secondary drop to the primary drop in partial coalescence is smaller than the reported values for coalescence without a surface tension gradient. The analytical model derived through this study is based on a new modified Ohnesorge number that includes surface tension gradients. Our analytical model is compared against other models and the results illustrate good agreement with our experimental findings and experimental data in the literature.
A single-atom heat engine
Authors: Lutz Eric
Published: May 2020

The power of an engine scales with the number of particles that make up its working fluid, a generalization that has proven true down to a single atom.
Upregulation of virulence genes promotes
Vibrio cholerae
biofilm hyperinfectivity
Authors: Gallego-Hernandez A. L. , DePas W. H. , Park J. H. , Teschler J. K. , Hartmann R. , Jeckel H. , Drescher K. , Beyhan S. , Newman D. K. , Yildiz F. H.
Published: May 2020

Vibrio cholerae
remains a major global health threat, disproportionately impacting parts of the world without adequate infrastructure and sanitation resources. In aquatic environments,
V. cholerae
exists both as planktonic cells and as biofilms, which are held together by an extracellular matrix.
V. cholerae
biofilms have been shown to be hyperinfective, but the mechanism of hyperinfectivity is unclear. Here we show that biofilm-grown cells, irrespective of the surfaces on which they are formed, are able to markedly outcompete planktonic-grown cells in the infant mouse. Using an imaging technique designed to render intestinal tissue optically transparent and preserve the spatial integrity of infected intestines, we reveal and compare three-dimensional
V. cholerae
colonization patterns of planktonic-grown and biofilm-grown cells. Quantitative image analyses show that
V. cholerae
colonizes mainly the medial portion of the small intestine and that both the abundance and localization patterns of biofilm-grown cells differ from that of planktonic-grown cells. In vitro biofilm-grown cells activate expression of the virulence cascade, including the toxin coregulated pilus (TCP), and are able to acquire the cholera toxin-carrying CTXФ phage. Overall, virulence factor gene expression is also higher in vivo when infected with biofilm-grown cells, and modulation of their regulation is sufficient to cause the biofilm hyperinfectivity phenotype. Together, these results indicate that the altered biogeography of biofilm-grown cells and their enhanced production of virulence factors in the intestine underpin the biofilm hyperinfectivity phenotype.
Single-cell resolution analysis of the human pancreatic ductal progenitor cell niche
Authors: Qadir Mirza Muhammad Fahd , Álvarez-Cubela Silvia , Klein Dagmar , van Dijk Jasmijn , Muñiz-Anquela Rocío , Moreno-Hernández Yaisa B. , Lanzoni Giacomo , Sadiq Saad , Navarro-Rubio Belén , García Michael T. , Díaz Ángela , Johnson Kevin , Sant David , Ricordi Camillo , Griswold Anthony , Pastori Ricardo Luis , Domínguez-Bendala Juan
Published: May 2020

We have described multipotent progenitor-like cells within the major pancreatic ducts (MPDs) of the human pancreas. They express PDX1, its surrogate surface marker P2RY1, and the bone morphogenetic protein (BMP) receptor 1A (BMPR1A)/activin-like kinase 3 (ALK3), but not carbonic anhydrase II (CAII). Here we report the single-cell RNA sequencing (scRNA-seq) of ALK3
bright+
-sorted ductal cells, a fraction that harbors BMP-responsive progenitor-like cells. Our analysis unveiled the existence of multiple subpopulations along two major axes, one that encompasses a gradient of ductal cell differentiation stages, and another featuring cells with transitional phenotypes toward acinar tissue. A third potential ducto-endocrine axis is revealed upon integration of the ALK3
bright+
dataset with a single-cell whole-pancreas transcriptome. When transplanted into immunodeficient mice, P2RY1
+
/ALK3
bright+
populations (enriched in PDX1
+
/ALK3
+
/CAII
−
cells) differentiate into all pancreatic lineages, including functional β-cells. This process is accelerated when hosts are treated systemically with an ALK3 agonist. We found PDX1
+
/ALK3
+
/CAII
−
progenitor-like cells in the MPDs of types 1 and 2 diabetes donors, regardless of the duration of the disease. Our findings open the door to the pharmacological activation of progenitor cells in situ.
Circadian clock control of eIF2α phosphorylation is necessary for rhythmic translation initiation
Authors: Karki Shanta , Castillo Kathrina , Ding Zhaolan , Kerr Olivia , Lamb Teresa M. , Wu Cheng , Sachs Matthew S. , Bell-Pedersen Deborah
Published: May 2020

Significance

Circadian clock control of mRNA translation, which contributes to the daily cycling of at least 50% of the proteins synthesized in eukaryotic cells, is understudied. We show that the circadian clock in the model fungus
Neurospora crassa
regulates rhythms in phosphorylation and activity of the conserved translation initiation factor eIF2α, with a peak in phosphorylated eIF2α levels during the daytime. This leads to reduced mRNA translation of select messages during the day and increased translation at night. We demonstrate that rhythmic accumulation of phosphorylated eIF2α requires increased uncharged tRNA levels during the day to activate the eIF2α kinase, coordinating rhythmic translation initiation and protein production with nutrient and energy metabolism.
Controlling photoionization using attosecond time-slit interferences
Authors: Cheng Yu-Chen , Mikaelsson Sara , Nandi Saikat , Rämisch Lisa , Guo Chen , Carlström Stefanos , Harth Anne , Vogelsang Jan , Miranda Miguel , Arnold Cord L. , L’Huillier Anne , Gisselbrecht Mathieu
Published: May 2020

When small quantum systems, atoms or molecules, absorb a high-energy photon, electrons are emitted with a well-defined energy and a highly symmetric angular distribution, ruled by energy quantization and parity conservation. These rules are based on approximations and symmetries which may break down when atoms are exposed to ultrashort and intense optical pulses. This raises the question of their universality for the simplest case of the photoelectric effect. Here we investigate photoionization of helium by a sequence of attosecond pulses in the presence of a weak infrared laser field. We continuously control the energy of the photoelectrons and introduce an asymmetry in their emission direction, at variance with the idealized rules mentioned above. This control, made possible by the extreme temporal confinement of the light–matter interaction, opens a road in attosecond science, namely, the manipulation of ultrafast processes with a tailored sequence of attosecond pulses.
Rapid topographic reorganization in adult human primary visual cortex (V1) during noninvasive and reversible deprivation
Authors: Jamal Yaseen A. , Dilks Daniel D.
Published: May 2020

Can the primary visual cortex (V1), once wired up in development, change in adulthood? Although numerous studies have demonstrated topographic reorganization in adult V1 following the loss of bottom-up input, others have challenged such findings, offering alternative explanations. Here we use a noninvasive and reversible deprivation paradigm and converging neural and behavioral approaches to address these alternatives in the experimental test case of short-term topographic reorganization in adult human V1. Specifically, we patched one eye in typical adults, thereby depriving the cortical representation of the other eye’s blind spot (BS), and immediately tested for topographic reorganization using functional magnetic resonance imaging and psychophysics. Strikingly, within just minutes of eye-patching, the BS representation in V1 began responding to stimuli presented outside of the BS, and these same stimuli were perceived as elongated toward the BS. Thus, we provide converging neural and behavioral evidence of rapid topographic reorganization in adult human V1, and the strongest evidence yet that visual deprivation produces bona fide cortical change.
The role of the Arp2/3 complex in shaping the dynamics and structures of branched actomyosin networks
Authors: Liman James , Bueno Carlos , Eliaz Yossi , Schafer Nicholas P. , Waxham M. Neal , Wolynes Peter G. , Levine Herbert , Cheung Margaret S.
Published: May 2020

Actomyosin networks give cells the ability to move and divide. These networks contract and expand while being driven by active energy-consuming processes such as motor protein walking and actin polymerization. Actin dynamics is also regulated by actin-binding proteins, such as the actin-related protein 2/3 (Arp2/3) complex. This complex generates branched filaments, thereby changing the overall organization of the network. In this work, the spatiotemporal patterns of dynamical actin assembly accompanying the branching-induced reorganization caused by Arp2/3 were studied using a computational model (mechanochemical dynamics of active networks [MEDYAN]); this model simulates actomyosin network dynamics as a result of chemical reactions whose rates are modulated by rapid mechanical equilibration. We show that branched actomyosin networks relax significantly more slowly than do unbranched networks. Also, branched networks undergo rare convulsive movements, “avalanches,” that release strain in the network. These avalanches are associated with the more heterogeneous distribution of mechanically linked filaments displayed by branched networks. These far-from-equilibrium events arising from the marginal stability of growing actomyosin networks provide a possible mechanism of the “cytoquakes” recently seen in experiments.
Cultured macrophages transfer surplus cholesterol into adjacent cells in the absence of serum or high-density lipoproteins
Authors: He Cuiwen , Jiang Haibo , Song Wenxin , Riezman Howard , Tontonoz Peter , Weston Thomas A. , Guagliardo Paul , Kim Paul H. , Jung Rachel , Heizer Patrick , Fong Loren G. , Young Stephen G.
Published: May 2020

Significance

By ingesting apoptotic cells and other cellular debris, macrophages accumulate cholesterol. Some of the cholesterol is esterified and stored in cytosolic lipid droplets, mitigating the toxicity from free cholesterol. Eventually, however, macrophages must unload surplus cholesterol—a process often referred to as “cholesterol efflux.” Cholesterol efflux is an important physiologic process because it would be expected to retard the formation of cholesterol-rich macrophage foam cells in atherosclerotic plaques. Most studies of cholesterol efflux have focused on the ability of ABC transporters to export cholesterol onto high-density lipoproteins. The current study examines another mechanism. We found, using NanoSIMS imaging, that [
13
C]cholesterol-loaded macrophages unload cholesterol directly into adjacent smooth muscle cells. This mechanism is potentially relevant to cholesterol efflux by tissue macrophages.
Quantum Fourier analysis
Authors: Jaffe Arthur , Jiang Chunlan , Liu Zhengwei , Ren Yunxiang , Wu Jinsong
Published: May 2020

Significance

Classical Fourier analysis, discovered over 200 years ago, remains a cornerstone in understanding almost every field of pure mathematics. Its applications in physics range from classical electromagnetism to the formulation of quantum theory. It gives insights into chemistry, engineering, and information science, and it underlies the theory of communication. Quantum Fourier analysis extends this perspective. It yields insights and inequalities associated with uncertainty principles for quantum symmetries. In this paper, we introduce this mathematical subject, we show how it can solve some theoretical problems, and we give some applications to quantum physics with bounds on entropy and the analysis of quantum entanglement. We believe that quantum Fourier analysis, now in its infancy, will have significant future impact.
A modified lysosomal organelle mediates nonlytic egress of reovirus
Authors: Fernández de Castro Isabel , Tenorio Raquel , Ortega-González Paula , Knowlton Jonathan J. , Zamora Paula F. , Lee Christopher H. , Fernández José J. , Dermody Terence S. , Risco Cristina
Published: May 2020

Mammalian orthoreoviruses (reoviruses) are nonenveloped viruses that replicate in cytoplasmic membranous organelles called viral inclusions (VIs) where progeny virions are assembled. To better understand cellular routes of nonlytic reovirus exit, we imaged sites of virus egress in infected, nonpolarized human brain microvascular endothelial cells (HBMECs) and observed one or two distinct egress zones per cell at the basal surface. Transmission electron microscopy and 3D electron tomography (ET) of the egress zones revealed clusters of virions within membrane-bound structures, which we term membranous carriers (MCs), approaching and fusing with the plasma membrane. These virion-containing MCs emerged from larger, LAMP-1–positive membranous organelles that are morphologically compatible with lysosomes. We call these structures sorting organelles (SOs). Reovirus infection induces an increase in the number and size of lysosomes and modifies the pH of these organelles from ∼4.5–5 to ∼6.1 after recruitment to VIs and before incorporation of virions. ET of VI–SO–MC interfaces demonstrated that these compartments are connected by membrane-fusion points, through which mature virions are transported. Collectively, our results show that reovirus uses a previously undescribed, membrane-engaged, nonlytic egress mechanism and highlights a potential new target for therapeutic intervention.
Efficient gene knockout in primary human and murine myeloid cells by non-viral delivery of CRISPR-Cas9
Authors: Freund Emily C. , Lock Jaclyn Y. , Oh Jaehak , Maculins Timurs , Delamarre Lelia , Bohlen Christopher J. , Haley Benjamin , Murthy Aditya
Published: May 2020

Myeloid cells play critical and diverse roles in mammalian physiology, including tissue development and repair, innate defense against pathogens, and generation of adaptive immunity. As cells that show prolonged recruitment to sites of injury or pathology, myeloid cells represent therapeutic targets for a broad range of diseases. However, few approaches have been developed for gene editing of these cell types, likely owing to their sensitivity to foreign genetic material or virus-based manipulation. Here we describe optimized strategies for gene disruption in primary myeloid cells of human and murine origin. Using nucleofection-based delivery of Cas9-ribonuclear proteins (RNPs), we achieved near population-level genetic knockout of single and multiple targets in a range of cell types without selection or enrichment. Importantly, we show that cellular fitness and response to immunological stimuli is not significantly impacted by the gene editing process. This provides a significant advance in the study of myeloid cell biology, thus enabling pathway discovery and drug target validation across species in the field of innate immunity.
On-site comparison of quantum Hall effect resistance standards of the NIM and the BIPM: ongoing key comparison BIPM.EM-K12
Authors: Gournay P , Rolland B , Lu Y , Zhao J
Published: May 2020

The ongoing on-site comparison BIPM.EM-K12 is part of the BIPM programme implemented to verify the international coherence of the primary resistance standards. It allows National Metrology Institutes (NMIs) to validate their implementations of the quantum Hall effect (QHE) for dc resistance traceability by comparison to the reference maintained at the BIPM.

The realization of the ohm from the QHE-based standard of the NMIs at 100 Ω is compared with that realized by the BIPM from its own transportable quantum Hall resistance standard. This comparison is usually completed by scaling measurements from 100 Ω to 1 Ω and 10 kΩ through the measurement of the resistance ratios 100 Ω/1 Ω and 10 kΩ/100 Ω, respectively.

In September 2019, a new BIPM.EM-K12 on-site comparison was carried out at the National Institute of Metrology of China (NIM). It was the first time the NIM participated in this comparison programme.

Measurements of the 100 Ω transfer standard in terms of the SI value of the von Klitzing constant, R
K, agreed to 4 parts in 1010 with a relative combined standard uncertainty u
c = 26 × 10−10. Measurements of 10 kΩ/100 Ω and 100 Ω/1 Ω ratios agreed to 50 parts in 1010 with u
c = 24 × 10−10 and to 10 parts in 1010 with u
c = 23 × 10−10, respectively.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Update of the BIPM comparison BIPM.RI(II)-K1.Ho-166m of activity measurements of the radionuclide 166mHo to include the 2017 results of the NMISA (South Africa) and update of the KCRV
Authors: Michotte C , Courte S , Nonis M , Rooy M W van , Staden M J van , Lubbe J
Published: May 2020

Since 1989, 6 national metrology institutes (NMI) have submitted 7 samples of known activity of 166mHo to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ho-166m. The values of the activity submitted were between about 70 kBq and 470 kBq. The key comparison reference value (KCRV) has been re-evaluated using the power-moderated weighted mean to include the PTB and NMISA results dated 2013 and 2017, respectively. There are now five valid results in the KCDB for the BIPM.RI(II)-K1.Ho-166m comparison and the degrees of equivalence between the equivalent activity measured in the SIR and the KCRV have been calculated. The degrees of equivalence for linked regional key comparisons (APMP and EURAMET) were updated.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Higher-order total variation approaches and generalisations
Authors: Bredies Kristian , Holler Martin
Published: May 2020

Over the last decades, the total variation (TV) has evolved to be one of the most broadly-used regularisation functionals for inverse problems, in particular for imaging applications. When first introduced as a regulariser, higher-order generalisations of TV were soon proposed and studied with increasing interest, which led to a variety of different approaches being available today. We review several of these approaches, discussing aspects ranging from functional-analytic foundations to regularisation theory for linear inverse problems in Banach space, and provide a unified framework concerning well-posedness and convergence for vanishing noise level for respective Tikhonov regularisation. This includes general higher orders of TV, additive and infimal-convolution multi-order total variation, total generalised variation, and beyond. Further, numerical optimisation algorithms are developed and discussed that are suitable for solving the Tikhonov minimisation problem for all presented models. Focus is laid in particular on covering the whole pipeline starting at the discretisation of the problem and ending at concrete, implementable iterative procedures. A major part of this review is finally concerned with presenting examples and applications where higher-order TV approaches turned out to be beneficial. These applications range from classical inverse problems in imaging such as denoising, deconvolution, compressed sensing, optical-flow estimation and decompression, to image reconstruction in medical imaging and beyond, including magnetic resonance imaging, computed tomography, magnetic-resonance positron emission tomography, and electron tomography.
An inexact non stationary Tikhonov procedure for large-scale nonlinear ill-posed problems
Authors: Bellavia S , Donatelli M , Riccietti E
Published: May 2020

In this work we consider the stable numerical solution of large-scale ill-posed nonlinear least squares problems with nonzero residual. We propose a non-stationary Tikhonov method with inexact step computation, specially designed for large-scale problems. At each iteration the method requires the solution of an elliptical trust-region subproblem to compute the step. This task is carried out employing a Lanczos approach, by which an approximated solution is computed. The ad-hoc choice of the trust region radius update and the structure of the step resulting from the use of the Lanczos approach, allows us to prove some regularizing properties of the method. The proposed approach is tested on a parameter identification problem and on an image registration problem, and it is shown to provide important computational savings with respect to its exact counterpart.
In vitro reliability testing and in vivo lifespan estimation of wireless Pixium Vision PRIMA photovoltaic subretinal prostheses suggest prolonged durability and functionality in clinical practice
Authors: Lemoine Delphine , Simon Emmanuel , Buc Guillaume , Deterre Martin
Published: May 2020

Objective. Retinal implants have the potential to restore some sight in patients with retinal degeneration. The PRIMA implant’s novel design features simpler insertion and no transscleral cabling or extraocular components. This in vitro study investigated PRIMA’s durability under real time and accelerated conditions and estimated the device’s lifespan in vivo. Approach. Two potential failure modes were examined: corrosion and overstimulation. Real-time aging was tested using implants immersed in balanced saline solution (BSS) at 37 °C, mimicking the intraocular environment. Accelerated aging was examined at 77 °C (Arrhenius theory). Confirmatory testing of acceleration factor was performed using different temperatures (37 °C–87 °C) and weakened implant coatings. The effect of repeated maximum stimulation was tested using a pulsed infrared laser (6x acceleration factor). Data were used to estimate device lifespan. Main results. 175 implants were tested for up to 33 months. No corrosion or water ingress was observed after approximately 20 accelerated years. A pixel failure rate of 0.15% was recorded after 10 accelerated years’ stimulation. The derived lifespan estimation for the PRIMA implant was 27.0 years with a reliability of 90% (95% confidence interval). Significance. The PRIMA implant was found to be robust, with in vitro reliability of at least 10 years. The PRIMA implant shows durability and functionality for clinically relevant timespans under similar environmental conditions to the human eye. These results require in vivo confirmation.
Ecosystem restoration on Hainan Island: can we optimize for enhancing regulating services and poverty alleviation?
Authors: Li Ruida , Zheng Hua , Polasky Stephen , Hawthorne Peter L , O’Connor Patrick , Wang Lijuan , Li Ruonan , Xiao Yi , Wu Tong , Ouyang Zhiyun
Published: May 2020

The restoration of ecosystems provides an important opportunity to improve the provision of ecosystem services. Achieving the maximum possible benefits from restoration with a limited budget requires knowing which places if restored would produce the best combination of improved ecosystem services. Using an ecosystem services assessment and optimization algorithm, we find choices that generate maximum benefits from ecosystem restoration. We applied a set of weights to integrate multiple services into a unified approach and find the optimal land restoration option given those weights. We then systematically vary the weights to find a Pareto frontier that shows potentially optimal choices and illustrates trade-offs among services. We applied this process to evaluate optimal restoration on Hainan Island, China, a tropical island characterized by multiple ecosystem service hotspots and conditions of poverty. We analyzed restoration opportunities with the goal of increasing a provisioning service, plantation revenue, and several water-related ecosystem services that contribute to improved water quality and flood mitigation. We found obvious spatial inconsistencies in the optimal location for maximizing separate services and tradeoffs in the provision of these services. Optimized land-use patterns greatly out-performed the non-target restoration scheme. When explicit consideration of the importance of poverty alleviation was taken into account, the location of the prioritized areas shifted and trade-offs among services varied. Our study emphasizes the importance of integrating social concerns into land-use planning to mitigate conflicts and improve equity, especially in the areas where poverty and hotspots of biodiversity and ecosystem services are highly geographically coincident.
Design, synthesis and characterization of hybrid coatings suitable for geopolymeric-based supports for the restoration of cultural heritage
Authors: Ielo I , Galletta M , Rando G , Sfameni S , Cardiano P , Sabatino G , Drommi D , Rosace G , Plutino M R
Published: May 2020

Geopolymers are inorganic materials that form long-range, covalently bonded, networks; they are materials similar to ceramics, whose components are mainly aluminium and silicates. Any inorganic source of silica and alumina, dissolved in the alkaline solution, acts as a precursor of geopolymers. The type of clays most commonly used in the synthesis of geopolymers is based on kaolinite. The present work concerns the modification of the geopolymer at the chemical and nanostructural level, through the design and development of hybrid coating sol-gel formulations to improve characteristics such as mechanical strength, chemical inertness, heat resistance and porosity for possible use in the restoration and conservation of cultural heritage. The methods of functionalization of the geopolymers here shown are: (i) the treatment of the geopolymeric surface, post-drying, through the application of the sol-gel directly on the monolith, for a modification of the surface properties; (ii) the pretreatment of the geopolymeric mixture, through the addition of the alkoxysilane which can induce a homogeneous consolidation of the molecular structure, implementing the properties of the entire monolith. The employed alkoxysilanes differ according to the length of the hydrocarbon chain and the presence of halogen atoms. Hydrophobicity tests were performed on these formulations.
Cyclodextrins in topical gel formulation as photoprotective system for Nabumetone
Authors: Occhiuzzi M A , Grande F , Luca M De , Ragno G , Garofalo A , Ioele G
Published: May 2020

Photostability studies applied on aqueous solutions of Nabumetone, an anti-inflammatory drug used in the treatment of osteoarthritis and rheumatoid arthritis, have confirmed the sensitivity to light of this compound, revealing the 6-methoxy-naphthalene-aldehyde as the main photoproduct. In this work, the stability of NA-cyclodextrin (CD) complexes was investigated in gel formulation potentially suitable as sustained-release systems. The photodegradation experiments were realized under stressed conditions according to the ICH rules and monitored by spectrophotometry. The spectral data were processed by Multivariate Curve Resolution (MCR), able to estimate spectra and concentration profiles of the components involved in the kinetic process. NA entrapped in cyclodextrin and formulated in solution and gel preparations were exposed to an irradiance power of 350 W/m2. Encapsulation percentage of the drug in several cyclodextrins was measured, recording an increase of the water solubility in the order hpβCD>mβCD>βCD. No significant photoprotection of NA was measured in aqueous solution. On the contrary, the gel containing the hpPCD-complex showed relevant stability. The photoprotective ability of this formulation was further increased by adding ascorbic acid 2%, still detecting 90% of the starting concentration after 90 min of light exposure.
Effect of alcohol/water on glycine crystal transition
Authors: Kokubu H. , Shimada Y. , Onoe K.
Published: May 2020

Glycine has three crystalline polymorphs (unstable β-type, metastable α-type and stable γ-type). Since glycine crystals have different physical properties such as solubility and stability depending on polymorphism, and the control of polymorphic selectivity is required in the manufacturing process of pharmaceuticals and foods. In this study, the unstable β-type crystals obtained by anti-solvent crystallization was focused as a starting material. Liquid phase water mixed with alcohol was brought into contact with β-type crystals, and the effect of the mixing ratio of water with alcohol around the crystals on the transition was investigated. As a result, it is clarified that the proportion of water in liquid phase alcohol/water has a large influence on the polymorphic selectivity of glycine crystals.