bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid separation of cannabinoid isomer sets using differential mobility spectrometry and mass spectrometry
Authors: Mashmoushi Nour , Larry Campbell J. , di Lorenzo Robert , Scott Hopkins W.
Published: April 2022

With legalization and decriminalization of cannabis in many parts of the world comes the need for rapid separation and quantitation of the psychoactive ingredients.
Ultra-high permeable phenine nanotube membranes for water desalination
Authors: Naskar Supriyo , Sahoo Anil Kumar , Moid Mohd , Maiti Prabal K.
Published: April 2022

Phenine nanotube membranes completely rejects salts and permeates water at a rate which is an order-of-magnitude higher than that of all the membranes used for water filtration.
Core-electron contributions to the molecular magnetic response
Authors: Orozco-Ic Mesías , Charistos Nickolas D. , Muñoz-Castro Alvaro , Islas Rafael , Sundholm Dage , Merino Gabriel
Published: April 2022

Dissecting the magnetic shielding tensor using natural localized molecular orbitals leads to an anomalous contribution from the core electrons. We solve this problem by computing the core- and σ-contributions to the magnetic response by removing the valence electrons (RVE).
Perturbation of the UV transitions of formaldehyde by TiO2photocatalysts and Aunnanoclusters
Authors: Høyer Nicolai Machholdt , Johnson Matthew S. , Mikkelsen Kurt V.
Published: April 2022

In the gas phase, formaldehyde has an electric-dipole forbidden transition that becomes allowed by vibronic coupling.
A dual-functional fluorescent biosensor based on enzyme-involved catalytic hairpin assembly for the detection of APE1 and miRNA-21
Authors: Lu Xiaoyong , Li Dan , Luo Zewei , Duan Yixiang
Published: April 2022

A dual-functional fluorescent biosensor based on enzyme-involved catalytic hairpin assembly (CHA) was developed for the detection of APE1 and miRNA-21, aiming at improving the accuracy of cancer diagnosis in the early phase.
Collective movement and thermal stability of fullerene clusters on the graphene layer
Authors: Vaezi Mehran , Nejat Pishkenari Hossein , Ejtehadi Mohammad Reza
Published: April 2022

Understanding the motion characteristics of fullerene clusters on the graphene surface is critical for designing surface manipulation systems.
Translational PK–PD for targeted protein degradation
Authors: Bartlett Derek W. , Gilbert Adam M.
Published: April 2022

This tutorial review provides practical insights and a proposed roadmap for building the translational PK–PD understanding for protein degrader therapeutics.
Metal-free photocleavage of the C(non-acyl)–S bond of thioesters for regioselective pyridylthioesterification of styrenes
Authors: Wu Qi , Zhao You-Hui , Lu-Lu Chai , Li Hai-Yan , Li Hong-Xi
Published: April 2022

We reported visible-light-promoted cleavage of the C(pyridyl)–S bond of S-2-pyridyl thioesters for highly regioselective pyridylthioesterification of styrenes via HNEt2-traceless-assisted formation of electron donor–acceptor complexes.
Photoinduced aerobic C–S borylation of aryl sulfides
Authors: Li Xinqi , Wan Zhen , Hu Xiaoyun , Zhang Hua
Published: April 2022

Direct C–S activation of aryl sulfides was achieved via a transition-metal-free photoinduced aerobic borylation process.
Triazolated calix[4]semitubes: assembling strategies towards long multicalixarene architectures
Authors: Malakhova Maria , Gorbunov Alexander , Ozerov Nikolay , Korniltsev Ilia , Ermolov Kirill , Bezzubov Stanislav , Kovalev Vladimir , Vatsouro Ivan
Published: April 2022

Triazolated triscalixarene semitubes with different mutual arrangements of two bistriazole sites can be assembled by a four-fold or stepwise CuAAC from calix[4]arenes having two or four 2-azidoethyl or/and propargyl groups in their structures.
Highly efficient ruthenium-catalyzed asymmetric hydrogenation of N-heteroaryl vinyl ethers
Authors: Feng Song , Ren Baoqi , Li Lige , Xia Fengmin , Tang Zhiyong , Zhang Yu , Liu Xiaoning , Lu Qixuan , Zhong Wenge
Published: April 2022

N-directing asymmetric hydrogenation of vinyl ether can afford excellent yield and ee without a coordinating group engagement.
Correction: Boosting the transport kinetics of free-standing SnS2@carbon nanofibers by electronic structure modulation for advanced lithium storage
Authors: Jiang Hui , Gan Yang , Liu Jie , Wang Xunlu , Ma Ruguang , Liu Jianjun , Wang Jiacheng
Published: April 2022

Correction for ‘Boosting the transport kinetics of free-standing SnS2@carbon nanofibers by electronic structure modulation for advanced lithium storage’ by Hui Jiang et al., J. Mater. Chem. A, 2022, https://doi.org/10.1039/D2TA01392D.
Tumor acidity/redox hierarchical-activable nanoparticles for precise combination of X-ray-induced photodynamic therapy and hypoxia-activated chemotherapy
Authors: Zhang Beibei , Xue Rui , Lyu Jisheng , Gao An , Sun Chunyang
Published: April 2022

The cascaded tumor acidity/redox responsive nanocarriers were designed for facilitating tumoral cell internalization and boosting X-PDT and hypoxia-activated chemotherapy.
Probability‐based fusion rule in cooperative spectrum sensing with impact of geographic location
Authors: Liu Xiaoying , Zheng Kechen
Published: April 2022

This paper investigates the impact of geographic locations of secondary users (SUs) on cooperative spectrum sensing (CSS) in cognitive radio networks (CRNs), where SUs send their local sensing results to a fusion center (FC) and the FC makes a global spectrum decision by a specific fusion rule. The purpose of this paper is to propose a fusion rule that takes into account the impact of geographic locations on CSS, and identify the optimal decision threshold of the proposed fusion rule in order to maximize the average achievable throughput of the secondary network subject to a collision constraint. To quantitatively capture the impact of geographic locations on CSS, a metric called absolute impact is defined, which is determined by the probability of detection and the probability of false alarm. Meanwhile, another metric is defined called relative impact to characterize the impact of SU's incorrect local sensing result on CSS. Based on the defined metrics, a probability‐based fusion rule is proposed, and the core idea is that the global spectrum decision of CSS is jointly determined by the local sensing results and the absolute impacts of SUs. Then the average achievable throughput of the secondary network and the collision probability are derived, both of which are proved to decrease with the decision threshold of the proposed fusion rule. By tackling the trade‐off between the accuracy of spectrum sensing and spectrum access opportunity caused by the decision threshold, an approximate algorithm based on the idea of the bisection method is proposed to obtain the optimal decision threshold that maximizes the average achievable throughput of the secondary network while protecting primary transmission to a predefined extent. Numerical results are carried out to verify the theoretical analyses and show the flexibility of the proposed fusion rule.
Self-consistent model for dust-gas coupling in protoplanetary disks
Authors: Batygin Konstantin , Morbidelli Alessandro
Published: April 2022

Various physical processes that ensue within protoplanetary disks - including vertical settling of icy and rocky grains, radial drift of solids, planetesimal formation, as well as planetary accretion itself - are facilitated by hydrodynamic interactions between H/He gas and high-Z dust. The Stokes number, which quantifies the strength of dust-gas coupling, thus plays a central role in protoplanetary disk evolution and its poor determination constitutes an important source of uncertainty within the theory of planet formation. In this work, we present a simple model for dust-gas coupling and we demonstrate that for a specified combination of the nebular accretion rate, Ṁ, and turbulence parameter a, the radial profile of the Stokes number can be calculated in a unique way. Our model indicates that the Stokes number grows sublinearly with the orbital radius, but increases dramatically across the water-ice line. For fiducial protoplanetary disk parameters of Ṁ = 10−8 M⊙ per year and α = 10−3, our theory yields characteristic values of the Stokes number on the order of St ~ 10−4 (corresponding to ~mm-sized silicate dust) in the inner nebula and St ~ 10−1 (corresponding to icy grains of a few cm in size) in the outer regions of the disk. Accordingly, solids are expected to settle into a thin subdisk at large stellocentric distances, while remaining vertically well mixed inside the ice line.
Morbus Whipple
Authors: Glaser Cornelia , Venhoff Nils
Published: April 2022

Der Morbus Whipple ist eine seltene, aber wichtige Ursache einer entzündlichen Gelenkerkrankung mit oligo- oder polyartikulärer Manifestation. Die Diagnosestellung erfolgt häufig erst nach Jahren bis Jahrzehnten. Die Arthritis ist charakterisiert durch ein unzureichendes Ansprechen auf antirheumatische Therapie, teilweise sogar eine Zunahme der Beschwerden unter Immunsuppression und dem potenziellen Risiko systemischer Krankheitsmanifestationen. Häufige Fehldiagnosen sind seronegative rheumatoide Arthritis und Spondyloarthritiden. Die Erkrankung tritt überwiegend bei Männern mittleren Lebensalters auf und kann unbehandelt tödlich verlaufen.
Kompression versus Scherkräfte – Übungsauswahl bei der Schulterrehabilitation
Authors: Brouwer Anne , Walther Hagen
Published: April 2022

Sowohl in der konservativen als auch in der operativen Nachbehandlung von Schulterverletzungen eignen sich Übungen in offener und geschlossener Kette – in jeder Reha-Phase. Bei der Übungsauswahl ist es wichtig zu wissen, bei welcher Bewegung welche Kräfte auf das Gelenk wirken.
Brønsted Base Catalyzed Conjugate Addition of β-Acylvinyl Anion Equivalents to α,β-Unsaturated Ketones
Authors: Kondoh Azusa , Terada Masahiro , Yamaguchi Sho , Watanabe Yushi
Published: April 2022

A Brønsted base catalyzed addition reaction of allyl sulfones having a diethoxyphosphoryloxy group, which are new precursors of β-acylvinyl anion equivalents, with α,β-unsaturated ketones was developed. The reaction proceeded efficiently under the influence of a phosphazene base as the catalyst. This is a rare example of a catalytic addition reaction of β-acylvinyl anion equivalents. A preliminary study on an asymmetric variant was also conducted with a chiral bis(guanidino)iminophosphorane catalyst.
CsF-Promoted Iodocyclization of Allenylphosphonates: A Convenient Approach to Highly Functionalized Oxaphospholenes
Authors: Chen Shufeng , Guo Le , Gao Yanpeng , Li Yingjie , Wang Yue , Li Weilong
Published: April 2022

A convenient CsF-promoted iodocyclization reaction of trisubstituted allenylphosphonates with iodine to construct highly functionalized oxaphospholene derivatives has been developed. A series of readily available starting materials including ferrocenylallenes, aromatic and alkyl substituted allenes can undergo the process successfully.
2D materials open opportunities for optical modulators
Authors: Patrick Chris
Published: April 2022

The rise of two-dimensional materials has led to the fabrication of optical modulators with new structures and mechanisms for communication, sensing, and computing
Propagation dynamics in a nonlocal delayed lattice dynamical system with bistable nonlinearity
Authors: Xu Zhaoquan , Wu Chufen
Published: April 2022

This paper is devoted to the study of wave propagation dynamics for a class of lattice dynamical systems with nonlocal delay and bistable nonlinearity. This problem arises from the propagation phenomenon in biological and physical systems. To understand the propagation phenomenon, we show that all the wave profiles are strictly increasing and are unique up to translation by establishing a series of technical comparison properties of solution. Moreover, we characterize the exact asymptotic behaviors of the wave profiles when they approach the stable steady states by using dynamical system methods.
The closeness of localized structures between the Ablowitz–Ladik lattice and discrete nonlinear Schrödinger equations: Generalized AL and DNLS systems
Authors: Hennig Dirk , Karachalios Nikos I. , Cuevas-Maraver Jesús
Published: April 2022

The Ablowitz–Ladik system, being one of the few integrable nonlinear lattices, admits a wide class of analytical solutions, ranging from exact spatially localized solitons to rational solutions in the form of the spatiotemporally localized discrete Peregrine soliton. Proving a closeness result between the solutions of the Ablowitz–Ladik system and a wide class of Discrete Nonlinear Schrödinger systems in a sense of a continuous dependence on their initial data, we establish that such small amplitude waveforms may be supported in nonintegrable lattices for significantly large times. Nonintegrable systems exhibiting such behavior include a generalization of the Ablowitz–Ladik system with power-law nonlinearity and the discrete nonlinear Schrödinger equation with power-law and saturable nonlinearities. The outcome of numerical simulations illustrates, in excellent agreement with the analytical results, the persistence of small amplitude Ablowitz–Ladik analytical solutions in all the nonintegrable systems considered in this work, with the most striking example being that of the Peregine soliton.
Magnetic field sensitivity of the photoelectrically read nitrogen-vacancy centers in diamond
Authors: Hruby Jaroslav , Gulka Michal , Mongillo Massimo , Radu Iuliana P. , Petrov Michael V. , Bourgeois Emilie , Nesladek Milos
Published: April 2022

In this work, we report on the sensitivity of photo-electrical detection of magnetic resonances (PDMR) for magnetometry measurement using low density nitrogen vacancy (NV) ensembles in CVD-grown diamond. We demonstrate that the selection of the laser excitation wavelength is of importance for achieving optimal magnetic field sensitivity. The PDMR sensitivity obtained using a yellow-green (561 nm) laser surpasses the performances of a green laser (532 nm), by suppressing the photoionization of defects other than NV centers (such as P1 centers). It consequently allows to carry out the PDMR measurements at lower laser powers with increased magnetic resonance contrast. Noticeably for both the green and the yellow-green illuminations, PDMR leads to an improved sensitivity to magnetic fields in the selected conditions compared to optically detected magnetic resonance.
Reweighted L1-norm regularized phase retrieval for x-ray differential phase contrast radiograph
Authors: Zhang Guangya , Li Jing , Deng Kai , Yue Songjie , Xie Weiping
Published: April 2022

Talbot–Lau x-ray grating interferometry greatly decreases the requirements on x-ray sources to realize differential phase contrast imaging and has found many applications in industrial and medical imaging. Phase retrieval from the noisy differential signal is crucial for quantitative analysis, comparison, and fusion with other imaging modalities. In this paper, we introduce a reweighted L1-norm based nonlinear regularization method for the phase retrieval problem. Both simulation and experimental results demonstrated that, comparing with the widely used L1-norm based regularization method and Wiener filter method, the proposed method is more effective both in eliminating the strip noises and in preserving the image detail.
The road ahead for ultrawide bandgap solar-blind UV photodetectors
Authors: Kalra Anisha , Muazzam Usman Ul , Muralidharan R. , Raghavan Srinivasan , Nath Digbijoy N.
Published: April 2022

This Perspective seeks to understand and assess why ultrawide bandgap (UWBG) semiconductor-based deep-UV photodetectors have not yet found any noticeable presence in real-world applications despite riding on more than two decades of extensive materials and devices’ research. Keeping the discussion confined to photodetectors based on epitaxial AlGaN and Ga2O3, a broad assessment of the device performance in terms of its various parameters is done vis-à-vis the dependence on the material quality. We introduce a new comprehensive figure of merit (CFOM) to benchmark photodetectors by accounting for their three most critical performance parameters, i.e., gain, noise, and bandwidth. We infer from CFOM that purely from the point of view of device performance, AlGaN detectors do not have any serious shortcoming that is holding them back from entering the market. We try to identify the gaps that exist in the research landscape of AlGaN and Ga2O3 solar-blind photodetectors and also argue that merely improving the material/structural quality and device performance would not help in making this technology transition from the academic realm. Instead of providing a review, this Perspective asks the hard question on whether UWBG solar-blind detectors will ever find real-world applications in a noticeable way and whether these devices will be ever used in space-borne platforms for deep-space imaging, for instance.
Giant magnetostriction and strain sensitivity of ZnFe2O4 film in out-of-plane configuration
Authors: Guchhait Suman , Aireddy H. , Keerthana  , Kander Niladri Sekhar , Biswas Sajib , Das Amal Kumar
Published: April 2022

We have investigated the in-plane and out-of-plane magnetostriction (λ) and strain sensitivity (dλ/dH) of the polycrystalline ZnFe2O4 (ZFO) film on an Si(100) substrate at room temperature using the optical cantilever beam magnetometer. A remarkable enhancement in magnetostriction (129.34%) and strain sensitivity (218.49%) is obtained in the out-of-plane configuration in comparison with the same in the in-plane configuration. The film possesses a high positive magnetostriction (strain sensitivity) of 325.67 ± 0.42 ppm (4.65×10−9A−1m) and 746.92 ± 1.18 ppm (14.81×10−9A−1m) for in-plane and out-of-plane geometry, respectively, at room temperature. The huge enhancement in magnetostriction and strain sensitivity is ascribed to the shape anisotropy of the ZFO/Si composite in the out-of-plane configuration, and thus, the out-of-plane configuration would be highly potential in designing magnetic actuators, magnetic memory devices, and bio-medical devices at room temperature.
Geometrical demonstration for persistence properties of a bi-Hamiltonian shallow water system
Authors: Freire Igor Leite
Published: April 2022

We present a geometrical demonstration for the persistence properties for a bi-Hamiltonian system modeling waves in a shallow water regime. Both periodic and non-periodic cases are considered, and a key ingredient in our approach is one of the Hamiltonians of the system.
The coexistence curve and surface tension of a monatomic water model
Authors: Coe Mary K. , Evans Robert , Wilding Nigel B.
Published: April 2022

We study the monatomic water model of Molinero and Moore the grand canonical ensemble Monte Carlo simulation. Measurements of the probability distribution of the number density obtained via multicanonical sampling and histogram reweighting provide accurate estimates of the temperature dependence of both the liquid–vapor coexistence densities and the surface tension. Using finite-size scaling methods, we locate the liquid–vapor critical point at Tc = 917.6 K, ρc = 0.311 g cm−3. When plotted in scaled variables, in order to test the law of corresponding states, the coexistence curve of monatomic water is close to that of real water. In this respect, it performs better than extended simple point charge (SPC/E), TIP4P, and TIP4P/2005 water.
Three port photonic and plasmonic demultiplexers based on Cross and U-shaped stub structures: Application for filtering and sensing
Authors: Khattou S. , Amrani M. , Mouadili A. , El Boudouti E. H. , Talbi A. , Akjouj A. , Djafari-Rouhani B.
Published: April 2022

We propose the design of three port photonic and plasmonic demultiplexers where filtering toward the two outputs is based on the phenomena of Fano resonances and electromagnetically induced transparency (EIT). We use a Cross-shape resonator in one output and a U-shape resonator composed of two stubs in the other output. We give a theoretical demonstration of the geometrical parameters of both resonators in order to filter one wavelength in one output while leaving the other output unperturbed. These results are confirmed by experimental validation in the radio frequency domain and a numerical simulation in the infrared (IR) domain using plasmonic metal–insulator–metal waveguides. The Cross resonator in the first output can give rise to an EIT resonance, whereas the U-shaped resonator in the second output may exhibit both EIT and Fano resonances depending on the lengths chosen for the stubs. Therefore, different demultiplexing schemes can be proposed such as achieving a Fano resonance in one output and an EIT in the other, or EIT resonances in both outputs. The Fano resonance is obtained by bringing resonance close to transmission zero, whereas the EIT results from the squeezing of resonance between two transmission zeros. When the widths of the resonances tend to zero, they transform to trapped or bound states in the continuum with an infinite lifetime. We show that the crosstalk between the two channels can be reduced to −82 dB and the sensitivity can reach 2390.8 nm/RIU, RIU is the refractive index units. Finally, we highlight the performance of our design as a high sensitive filter and sensor in the IR domain. In this work, the analytical calculations and demonstrations are performed by using Green’s function approach, the experimental verifications are realized by means of coaxial cables operating in the radio frequency range and the numerical simulations are obtained using the finite element method via Comsol Multiphysics software.
Variational principle of a shock stationed in a duct
Authors: Luo Tianyi , Shan Peng
Published: April 2022

This paper establishes a variational principle of a normal shock stationed in ducts of the various quasi-one-dimensional (quasi-1D) steady non-conservative flow systems. It is found that the locational stability of a shock inside these ducts, namely, the stationary property of the shock, can be judged by analyzing the second-order variation of the potential energy functional of flow impulse with respect to the locational function of the shock. It proves that, for a control volume containing a shock inside a duct, the real stationary location of the shock among all the possible locations satisfying the determined inlet and outlet boundary conditions of the duct is equivalent to that the potential energy of the cross-sectional flow impulse integrated through the entire duct is a minimal. First, the shock location in general duct flows is analyzed by a momentum relaxation method. Then, based on this method, this paper's variational principle is established referring to the principle of minimum potential energy and the principle of virtual displacement. Further, this principle is applied to the flows through a quasi-1D variable-area duct, a one-dimensional (1D) frictional constant-area duct, a 1D heat-exchange constant-area duct, and a 1D mass-additional constant-area duct, which verified the generality of the principle. At last, relevant examples are provided. This variational principle affords a unified and concise theoretical criterion to analyze the stationary property of a normal shock.
Ion beam composition in ion source based on magnetron sputtering discharge at extremely low working pressure
Authors: Vizir A. V. , Bugaev A. S. , Frolova V. P. , Gushenets V. I. , Nikolaev A. G. , Oks E. M. , Yushkov G. Yu.
Published: April 2022

In an ion source based on a pulsed planar magnetron sputtering discharge with gas (argon) feed, the fraction of metal ions in the ion beam decreases with decreasing gas pressure, down to the minimum possible working pressure of the magnetron sputtering discharge. The use of a supplementary vacuum arc plasma injector provides stable operation of the pulsed magnetron sputtering discharge at extremely low pressure and without gas feed. Under these conditions, the pressure dependence of the gaseous ion fraction displays a maximum (is nonmonotonic).
Observing the orbital angular momentum of Fe and Co in chiral magnet Fe0.75Co0.25Si using soft x-ray magnetic circular dichroism
Authors: Mito M. , Ohkuma M. , Tajiri T. , Kousaka Y. , Akimitsu J. , Inoue K. , Amamiya K.
Published: April 2022

The intermetallic compound Fe1−xCoxSi has a helical magnetic order for 0.05<x<0.8, whereas its orbital angular momentum contributing to the occurrence of a Dzyaloshinskii–Moriya interaction has not yet been verified. We applied soft x-ray magnetic circular dichroism spectroscopy on the Fe L2,3 and Co L2,3 edges below Tc for Fe0.75Co0.25Si such that their orbital magnetic moments morb were evaluated independently. The dichroic signals provide direct experimental evidence that morb for both Fe and Co is coupled in a parallel manner with each spin counterpart mspin. The ratio of morb to mspin is independently estimated as morb/mspin∼3% for Fe and 9% for Co. By comparing the average of the two mspin values with the saturated magnetization using a commercial superconducting quantum interference device (SQUID) magnetometer, the hole number in the d bands for both Fe and Co is roughly estimated as approximately 1.5. This suggests that Fe and Co should be arranged closely for stabilizing the ferromagnetic moments.
Nanorefrigerative tweezers for optofluidic manipulation
Authors: Zhou Jianxing , Dai Xiaoqi , Jia Boliang , Qu Junle , Ho Ho-Pui , Gao Bruce Zhi , Shao Yonghong , Chen Jiajie
Published: April 2022

Plasmonic optical tweezers with the ability to manipulate nano-sized particles or molecules that are beyond the diffraction limit have been developed rapidly in recent years. However, plasmonic heat generation always limits its applications in capturing particles or biomacromolecules that are vulnerable to high temperatures. Here, we propose nanorefrigerative tweezers based on a single refrigerative nanocrystal, which can form a nanometer-sized cold-spot via anti-Stokes fluorescence. Numerical simulations are performed to compute the temperature and velocity fields. The results show that thermo-osmosis and thermophoresis play major roles in nanoparticle manipulation, while natural convection in the nanoscale is negligible. This tweezing scheme not only offers a sub-diffraction-limit way to manipulate nano-objects but also avoids possible thermal damage to the trapped targets. Therefore, it will potentially become a powerful tool in biomedical and biosensing research studies.
Lock-in carrierography of semiconductors and optoelectronics
Authors: Sun Qiming , Zhao Binxing , Wang Jing
Published: April 2022

Lock-in carrierography (LIC), a recently emerging camera-based imaging technique, is proving to be very promising for noncontact and quantitative characterization of electrical/electronic properties of semiconductor and optoelectronic materials/devices at different stages of research, fabrication, and manufacturing. This tutorial is devoted to LIC and it contains four sections. First, the background of the terminology, the needs from the electronics industry, and the research progress of LIC are briefly introduced. Section II is regarding homodyne LIC, including the relevant basics (semiconductor and photoluminescence physics, digital lock-in imaging strategy, experimental configuration, etc.) and its applications to carrier effective lifetime imaging, resistivity imaging, and Si solar cell electrical characterization, while Sec. III is for heterodyne LIC, including the relevant basics (high-frequency carrier density waves, heterodyne photoluminescence signal generation mechanisms, nonlinear carrier recombination dynamics, etc.) and its applications to surface recombination velocity imaging, carrier trapping dynamic parameters imaging, and quantum-dot solar cell characterization. Comments and advice on the future study of LIC are given in the Outlook section.
The ubiquitin–proteasome system regulates meiotic chromosome organization
Authors: Yang Xiao , Song Meihui , Wang Ying , Tan Taicong , Tian Zhongyu , Zhai Binyuan , Yang Xuan , Tan Yingjin , Cao Yanding , Dai Shaojun , Wang Shunxin , Zhang Liangran
Published: April 2022

Significance

Meiotic crossover recombination is required for faithful chromosome segregation and promotes genetic diversity by reshuffling alleles between parental chromosomes. Meiotic chromosomes are organized into arrays of loops that are anchored to the proteinaceous axes. The length of the meiotic chromosome axis is intimately associated with crossover frequencies in yeast and higher eukaryotes. However, how chromosome axis length is regulated in meiosis is unknown. Here, we demonstrate that cohesin regulator Pds5 interacts with proteasomes to regulate meiotic chromosome axis length by modulating ubiquitination. This regulatory mechanism also includes two ubiquitin E3 ligases, SCF (Skp–Cullin–F-box) and Ufd4. These findings identify a molecular pathway in regulating chromosome organization and reveal an unexpected function of the ubiquitin–proteasome system in meiosis.
Discovery of unusual dimeric piperazyl cyclopeptides encoded by a
Lentzea flaviverrucosa
DSM 44664 biosynthetic supercluster
Authors: Li Chunshun , Hu Yifei , Wu Xiaohua , Stumpf Spencer D. , Qi Yunci , D’Alessandro John M. , Nepal Keshav K. , Sarotti Ariel M. , Cao Shugeng , Blodgett Joshua A. V.
Published: April 2022

Rare actinomycetes represent an underexploited source of new bioactive compounds. Here, we report the use of a targeted metabologenomic approach to identify piperazyl compounds in the rare actinomycete
Lentzea flaviverrucosa
DSM 44664. These efforts to identify molecules that incorporate piperazate building blocks resulted in the discovery and structural elucidation of two dimeric biaryl-cyclohexapeptides, petrichorins A and B. Petrichorin B is a symmetric homodimer similar to the known compound chloptosin, but petrichorin A is unique among known piperazyl cyclopeptides because it is an asymmetric heterodimer. Due to the structural complexity of petrichorin A, solving its structure required a combination of several standard chemical methods plus in silico modeling, strain mutagenesis, and solving the structure of its biosynthetic intermediate petrichorin C for confident assignment. Furthermore, we found that the piperazyl cyclopeptides comprising each half of the petrichorin A heterodimer are made via two distinct nonribosomal peptide synthetase (NRPS) assembly lines, and the responsible NRPS enzymes are encoded within a contiguous biosynthetic supercluster on the
L. flaviverrucosa
chromosome. Requiring promiscuous cytochrome p450 crosslinking events for asymmetric and symmetric biaryl production, petrichorins A and B exhibited potent in vitro activity against A2780 human ovarian cancer, HT1080 fibrosarcoma, PC3 human prostate cancer, and Jurkat human T lymphocyte cell lines with IC
50
values at low nM levels. Cyclic piperazyl peptides and their crosslinked derivatives are interesting drug leads, and our findings highlight the potential for heterodimeric bicyclic peptides such as petrichorin A for inclusion in future pharmaceutical design and discovery programs.
The Spectrum Variabilities of FSRQ 3C 273
Authors: Yuan Y. H. , Zheng Y. G. , Fan J. H. , Hao J. M. , Xiao H. B.
Published: April 2022

3C 273 is a well-studied FSRQ. In order to analyze its spectrum variabilities, we make spectroscopic observations of 3C 273 using the 2.16 m telescope at Xinglong Observatory of the National Astronomical Observatories. Based on these observations and some other spectra from the literature, we study the spectrum variabilities and the physical origin of the optical spectrum. The main results are as follows: (1) The continuum spectrum (S

c
) shows obvious variabilities and displays quasi-periodic properties, P = 3.39 ± 1.13 yr, consistent with the result calculated from photometric observations. (2) The spectral energy distribution (SED) was modeled by a combination of blackbody emission that originated from the accretion disk and the dusty torus, synchrotron emission from the jet, the synchrotron self-Compton (SSC) emission, and the external Compton (EC) emission from the broad-line region, accretion disk, and dusty torus. The SED suggests that the optical continuum is dominated by the thermal emission from the accretion disk. (3) A time delay of

τ

c

H

β

=
209.42
±
9.38

days lies between the slope of the continuum spectrum (S

c
) and H
β
emission line. (4) The relationships between the spectrum and polarization can be explained by the jet model.
An approachable, flexible and practical machine learning workshop for biologists
Authors: Magnano Chris S , Mu Fangzhou , Russ Rosemary S , Cvetkovic Milica , Treu Debora , Gitter Anthony
Published: April 2022

The increasing prevalence and importance of machine learning in biological research have created a need for machine learning training resources tailored towards biological researchers. However, existing resources are often inaccessible, infeasible or inappropriate for biologists because they require significant computational and mathematical knowledge, demand an unrealistic time-investment or teach skills primarily for computational researchers. We created the Machine Learning for Biologists (ML4Bio) workshop, a short, intensive workshop that empowers biological researchers to comprehend machine learning applications and pursue machine learning collaborations in their own research. The ML4Bio workshop focuses on classification and was designed around three principles: (i) emphasizing preparedness over fluency or expertise, (ii) necessitating minimal coding and mathematical background and (iii) requiring low time investment. It incorporates active learning methods and custom open-source software that allows participants to explore machine learning workflows. After multiple sessions to improve workshop design, we performed a study on three workshop sessions. Despite some confusion around identifying subtle methodological flaws in machine learning workflows, participants generally reported that the workshop met their goals, provided them with valuable skills and knowledge and greatly increased their beliefs that they could engage in research that uses machine learning. ML4Bio is an educational tool for biological researchers, and its creation and evaluation provide valuable insight into tailoring educational resources for active researchers in different domains.

Availability and implementation

Workshop materials are available at https://github.com/carpentries-incubator/ml4bio-workshop and the ml4bio software is available at https://github.com/gitter-lab/ml4bio.

Supplementary information

Supplementary data are available at Bioinformatics online.
Culture–gene co-evolution: Darwin’s other theory comes into view
Authors: Corning Peter A
Published: April 2022

The concept of ‘natural selection’, as proposed in The Origin of Species (published in 1859), refers to the better known of Charles Darwin’s two distinct theories of evolution. Darwin’s other theory was originally associated with his predecessor, Jean-Baptiste de Lamarck. (Darwin used the shorthand phrase, the ‘use and disuse of parts’, to characterize this alternative theory.) Lamarck’s theory was rejected (and even mocked) by many 20th century theorists, who instead adopted a gene-centred, one-way, bottom-up model of evolutionary change, called the modern synthesis. (It has also been termed neo-Darwinism.) Darwin was more receptive to Lamarck’s approach, and in his second great work, The Descent of Man (published in 1874), he applied this Lamarckian theory particularly to human evolution. He ascribed our remarkable evolutionary success to our behaviour: social cooperation, innovation (and tools), morality and cumulative culture. Neo-Darwinists called it Darwin’s biggest mistake. However, an ever-increasing body of evidence, inclusive of cultural phenomena in many other species, suggests that it was, in fact, their mistake. Often called gene–culture co-evolution theory, the reverse order (as used here) might be a better way of characterizing the underlying causal dynamics. The ‘purposeful’ behaviour (teleonomy) of living systems has exerted a major influence on the trajectory of biological evolution.
Technical design and environmental analysis of 100-kWp on-grid photovoltaic power plant in north-western Iran
Authors: Vatankhah Ghadim Hadi , Fallah Ardashir Jaber
Published: April 2022

Due to the fuel security and environmental concerns of traditional energy resources like fossil fuels, grid operators are tending to use renewable energies as the primary energy supply. This paper presents the study of designing, simulation and analysis of a 100-kWp on-grid photovoltaic power plant (PV-PP) in north-western Iran. Accurate meteorological data, satellite images and local knowledge from this region have narrowed down the options to three highly irradiated cities of Maragheh, Mahabad and Khalkhal in this region. PVsyst and MATLAB software are used in this paper to obtain the performance results. Environmental effects and carbon-emission savings from the execution of the proposed PV-PP are also available in this paper. The result of this study shows that PV-PP installation in Maragheh will have higher energy output than the two other cities. This study is insightful for the academics and the grid stakeholders in finding optimal spots in north-western Iran to construct a PV-PP. Also, recommendations are available for future studies.

A 100-kWp on-grid photovoltaic power plant is designed in north-western Iran. Accurate meteorological data, satellite images, and local knowledge are used in a simulation to select the best location from among three cities.
Nephrotoxicity of perfluorooctane sulfonate (PFOS)—effect on transcription and epigenetic factors
Authors: Wen Yi , Rashid Faizan , Fazal Zeeshan , Singh Ratnakar , Spinella Michael J , Irudayaraj Joseph
Published: April 2022

Perfluorooctane sulfonate (PFOS) is a widespread persistent environmental pollutant implicated in nephrotoxicity with altered metabolism, carcinogenesis, and fibrosis potential. We studied the underlying epigenetic mechanism involving transcription factors of PFOS-induced kidney injury. A 14-day orally dosed mouse model was chosen to study acute influences in vivo. Messenger RNA expression analysis and gene set enrichment analysis were performed to elucidate the relationship between epigenetic regulators, transcription factors, kidney disease, and metabolism homeostasis. PFOS was found to accumulate in mouse kidney in a dose-dependent manner. Kidney injury markers Acta2 and Bcl2l1 increased in expression significantly. Transcription factors, including Nef2l2, Hes1, Ppara, and Ppard, were upregulated, while Smarca2 and Pparg were downregulated. Furthermore, global DNA methylation levels decreased and the gene expression of histone demethylases Kdm1a and Kdm4c were upregulated. Our work implicates PFOS-induced gene expression alterations in epigenetics, transcription factors, and kidney biomarkers with potential implications for kidney fibrosis and kidney carcinogenesis. Future experiments can focus on epigenetic mechanisms to establish a panel of PFOS-induced biomarkers for nephrotoxicity evaluation.
Atrial pacing to suppress ventricular arrhythmias in the critically ill patients: a case report
Authors: Riad Omar , Russell Clare , Garfield Ben , Behar Jonathan M.
Published: April 2022

Background

Atrial and ventricular arrhythmias are common in the critically ill due to a variety of factors including sepsis, myocardial ischaemia, renal dysfunction, and electrolyte disturbances. Anti-arrhythmic medications can be useful to control arrhythmias but can result in bradycardia and haemodynamic compromise. A paced atrial rhythm alongside normal atrioventricular conduction can be helpful to treat bradycardia, prevent arrhythmias, and support cardiac output.

Case summary

A 55-year-old gentleman with pseudomonas pneumonia, respiratory failure necessitating mechanical haemodynamic support, and subsequent coronary ischaemia presented to the intensive care unit. Paroxysms of atrial fibrillation and ventricular arrhythmias caused haemodynamic embarrassment and presented an ongoing clinical challenge as anti-arrhythmic medications resulted in bradycardia and Torsade de Pointes. Atrial pacing mediated intrinsic conduction via the His-Purkinje system inhibited ventricular ectopy and further arrhythmia breaking the tachycardia—bradycardia cycle; this stabilized the patient, facilitated ongoing intensive therapy unit care and promoted recovery.

Conclusion

Atrial pacing mediated intrinsic conduction via the His-Purkinje system is an effective approach to suppress ventricular ectopy and sustained arrhythmias whilst protecting the patient from haemodynamically compromising bradycardia.
Reversible myocardial ischaemia caused by ectopic left circumflex coronary artery: a case report
Authors: Sillanmäki Saara , Istomina Maria , Husso Annastiina , Hedman Marja
Published: April 2022

Background

Coronary artery anomalies (CAAs) are congenital disorders associated with variable manifestations and pathophysiological mechanisms. Anomalies can be asymptomatic or cause chest pain, myocardial infarction, or even sudden cardiac death.

Case summary

We describe a 34-year-old man with a history of a single episode of chest pain. An ectopic origin on the part of the left circumflex (LCX) coronary artery from the proximal right coronary artery (RCA) was evident upon coronary computed tomography angiography. A positron emission tomography perfusion study revealed a stress-induced perfusion defect in the anomalous LCX territory (infero-posterior wall). The patient experienced dyspnoea and ST-segment depression in electrocardiography, suggestive of myocardial ischaemia during the maximal bicycle ergometer stress test. No mechanical compression or stenosis was seen upon invasive coronary angiography. The left ventricular perfusion normalized after the initiation of beta-blocker medication.

Discussion

Patients with CAAs especially benefit from a multimodality assessment of the vascular territories. In our case, the myocardial perfusion of the infero-posterior wall normalized after treatment with beta-blockers. This may be due to increased coronary vasodilation capacity and myocardial flow reserve, as well as reduced oxygen consumption. Beta-blockers may represent a viable option in low-symptomatic CAA patients with perfusion defect and no ostial stenosis or compression.
OR3. Admission blood glucose and ischemic time are associated with successful fibrinolysis in combined assessment of ST-segment resolution, myocardial infarction flow grade, and myocardial perfusion grade
Authors: Rusnanta F , Rohman M Saifur , Prasetya I , Rizal A , Kurnianingsih N
Published: April 2022

Background and Aims

Fibrinolytic therapy (FT) is the alternative recommendation in patients with ST-segment elevation myocardial infarction (STEMI) if primary percutaneous coronary intervention (PCI) could not be perfomed timely at initial presentation. Successful revascularization of occluded infarct-related coronary arteries depends on complex mechanisms of hemodynamic, clinical, biochemical, and mechanical parameters. This study aimed to find out predictors of complete reperfusion after FT based on Thrombolysis in Myocardial Infarction (TIMI) 3 flow, Myocardial Blush Grade (MBG) 3, and ST-segment resolution.

Method and Results

This retrospective study was held in Saiful Anwar, Malang Hospital during 2017-2021, including total of 142 patients. All patients received FT and coronary angiographic evaluation post-FT. Those were divided into 3 groups, which included R0,1 (0/1 highest measure of reperfusion), R2 (2 highest measures of reperfusion), and R3 (3 highest measures of reperfusion). Admission blood glucose (ABG) (OR 0.99 [95%CI -0.16;-0.001]; p = 0.025), ischemic time (OR 0.82 [95%CI -0.491;-0.137]; p = 0.001), and triglycerides (OR 0.98 [95%CI 0.23;-0.006]; p = 0.001) were negatively correlated to the complete restoration of reperfusion (R3). ABG<140 mg/dL (AUC 0.701 [95%CI 0.612-0.790]; p = 0.000) and ischemic time<5 hours (AUC 0.742 [95%CI 0.645-0.839]; p = 0.000) were significant predictors for R ≥ 2. Coronary characteristics were not related to measure of reperfusion (p = 0.25).

Conclusion

ABG<140 mg/dL and ischemic time<5 hours are important predictors of successful reperfusion post FT (R ≥ 2), along with triglycerides. Early assessment of patients who are likely to have low parameter reperfusion (R < 2) would help promptly preparing for primary PCI.
OR7. Validation study: Association between aortoseptal angulation on echocardiography with the origin of outflow tract ventricular arrhythmias
Authors: Saputra Charles , Raharjo Sunu Budhi , Kuncoro Ario Soeryo , Soesanto Amiliana Mardiani , Rudiktyo Estu , Hermanto Dony Yugo , Yuniadi Yoga , Hanafy Dicky Armein , Ariani Rina
Published: April 2022

Background

Radiofrequency ablation (RFA) has become therapeutic modality with high success rate for outflow tract ventricular arrhythmia (OTVA). Determining the origin of OTVA before ablation is important to choose the appropriate approach, avoiding multiple complications, and saving fluoroscopy time. ECG-based criteria is a method that has been widely used to predict the origin of OTVA, but it oftenly has inconsistent diagnostic value. Previous study showed that aortoseptal angulation by echocardiography might be beneficial to predict the origin of OTVA. We need to validate the result in a prospective manner.

Objective

To validate the association between aortoseptal angulation measurements by echocardiography and OTVA origin.

Methods

A validation of diagnostic study involving patients VTs/PVCs with the ECG’s morphology of LBBB and inferior axis who underwent RFA therapy. An echocardiography examination was held before RFA therapy. Aortoseptal angulation is measured on parasternal long axis (PLAX)view to measure the angle between the aortic root and interventricular septum. The origin of OTVA was determined by mapping during RFA.

Results

There were 41 subjects with a mean age of 44.7±12.6 years. Majority of subjects were patients with right OTVA (n = 34, 82.9%). The mean aortoseptal angulation of the left OTVA 127.2±2.8 was significantly smaller than the right OTVA 136.7±5.7(p < 0.001). An angle below 129.2o has 71.4% sensitivity and 85.29% specificity to predict an LVOT origin.

Conclusion

This validation study proved that aortoseptal angulation measurement by echocardiography <129,2o is a valid diagnostic tool to differentiate left OTVA origin with OR 10,1.
OR8. Appropriateness of percutaneous coronary intervention procedure in Indonesia
Authors: Hadisoemarto P F , Tarsidin N F , Ariska L , Wandira R D , Tiksnadi B B , Masytoh L S , Dany F , Sastroasmoro S
Published: April 2022

Background and Aims

There is a possibility of the high variability of the appropriateness of PCI performed in Indonesia. It is assumed that appropriate PCI tends to have clinical outcomes than other categories. This study aimed to evaluate the appropriateness of the percutaneous coronary intervention (PCI) procedure in Indonesia.

Method and Results

We assigned appropriateness ratings to 214 acute coronary syndromes (ACS) and 191 stable ischemic heart disease (SIHD) records that underwent PCI in four hospitals from 2017 - 2018. The included hospitals consist of one public and three private hospitals, two cardiovascular centers, and two general hospitals with the most performed PCI procedures on 2016 - 2018 and accessible to the researchers. The PCI appropriateness was adjudicated using 2016/2017 ACC/AHA guidelines of the Appropriate Use of Care (AUC) for coronary revascularization in ACS and SIHD. The results were categorized into “appropriate”, “maybe appropriate”, and “rarely appropriate”.  

The result from this study demonstrated that in ACS patients, 76.0% and 24.0% of PCI were appropriate” and “maybe appropriate”. While, in SHID patients, 68.7%, 28.7%, and 2.6% of PCI were “appropriate”, “maybe appropriate”, and “rarely appropriate”. In ACS patients, “appropriate” PCI is more commonly found in ST-elevation myocardial infarction (STEMI) cases (62.6%). In SIHD patients, 54.0% and 46.0% of left-main diseases patients underwent “maybe appropriate” and “rarely appropriate” PCI. 

Conclusion

The majority of PCI performed in ACS and SIHD patients from the studied hospitals are “appropriate”.