bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cluster Analysis of Submicron Particle Number Size Distributions at the SORPES Station in the Yangtze River Delta of East China
Authors: Chen Liangduo , Qi Ximeng , Nie Wei , Wang Jiaping , Xu Zheng , Wang Tianyi , Liu Yuliang , Shen Yicheng , Xu Zhengning , Kokkonen Tom V. , Chi Xuguang , Aalto Pasi P. , Paasonen Pauli , Kerminen Veli‐Matti , Petäjä Tuukka , Kulmala Markku , Ding Aijun 
Published: June 2021

AbstractSubmicron particles in polluted regions have received much attention because of their influences on human health and climate. A k‐means clustering technique was performed on a data set of particle number size distributions (PNSD) that was obtained over more than 3 years in the Yangtze River Delta (YRD) region of East China. With simultaneous measurements of meteorological conditions, trace gases and aerosol compositions, seven clusters were categorized and interpreted. Cluster 1 and cluster 2, which accounted for 9.9% of the total PNSD data, were attributed to new particle formation (NPF) and vehicle exhaust emissions with different intensities; Cluster 3 and Cluster 4, which accounted for 10.5% of the total PNSD data, were related to the growth of nucleation mode particles; Cluster 5, which accounted for 37.9% of the total data, was attributed to the humid YRD background; and Cluster 6 and Cluster 7, which accounted for 41.6% of the total data set, were both pollution‐related clusters with similar mass concentrations but completely different PNSD. Although the PM2.5 mass concentrations were somewhat similar, the particle number concentrations of the accumulation mode particles could vary by more than one order of magnitude from the urban background cluster to the pollution‐related clusters. The cluster proximity diagram and conversion flow chart of clusters clearly show the influence of NPF and growth on haze, as well as the conversion between background and polluted conditions. This study highlights the importance of PNSD for understanding urban air quality and recommends the clustering technique for analyzing complex PNSD datasets.
Magnetic Reconnection in a Sheared Magnetic Flux Tube: Slippage Versus Tearing
Authors: Kuniyoshi Hidetaka , Hesse Michael , Norgren Cecilia , Tenfjord Paul , Kwagala Norah Kaggwa 
Published: June 2021

AbstractThe process of magnetic reconnection in a flux tube can occur in a time‐stationary fashion as slippage reconnection or in a time‐dependent manner based on, for example, the tearing instability. However, it is not well known under which conditions a system can sustain slippage reconnection. Likewise, it is unclear whether systems can exhibit slippage reconnection and time‐dependent reconnection simultaneously. In order to investigate these questions, we employ a set of 3D magnetohydrodynamic simulation. Using these simulations, we model a twisted flux tube with a spatially localized resistive region in the center of the simulation box, and an applied driver on one end plane of the simulation box. As a result, the Poynting flux injected at the boundary propagates to the resistive region and dissipates there. If the driver is nearly circular, we find a predominance of slippage reconnection, which decouples the applied driver entirely from one half of the flux tube. Second, a tearing‐like instability occurs with slippage reconnection in the resistive region when the resistivity is strong enough and the cross section of the flux tube, as defined by the shape of the applied velocity perturbation, is elliptical enough. In this case we find the surprising feature that magnetic field perturbation generated by the tearing‐like instability radiates away from the resistive region to influence the entire flux tube shape.
In-situ diagnostic of femtosecond laser probe pulses for high resolution ultrafast imaging
Authors: Xie Chen , Meyer Remi , Froehly Luc , Giust Remo , Courvoisier Francois 
Published: June 2021

AbstractUltrafast imaging is essential in physics and chemistry to investigate the femtosecond dynamics of nonuniform samples or of phenomena with strong spatial variations. It relies on observing the phenomena induced by an ultrashort laser pump pulse using an ultrashort probe pulse at a later time. Recent years have seen the emergence of very successful ultrafast imaging techniques of single non-reproducible events with extremely high frame rate, based on wavelength or spatial frequency encoding. However, further progress in ultrafast imaging towards high spatial resolution is hampered by the lack of characterization of weak probe beams. For pump–probe experiments realized within solids or liquids, because of the difference in group velocities between pump and probe, the determination of the absolute pump–probe delay depends on the sample position. In addition, pulse-front tilt is a widespread issue, unacceptable for ultrafast imaging, but which is conventionally very difficult to evaluate for the low-intensity probe pulses. Here we show that a pump-induced micro-grating generated from the electronic Kerr effect provides a detailed in-situ characterization of a weak probe pulse. It allows solving the two issues of absolute pump–probe delay determination and pulse-front tilt detection. Our approach is valid whatever the transparent medium with non-negligible Kerr index, whatever the probe pulse polarization and wavelength. Because it is nondestructive and fast to perform, this in-situ probe diagnostic can be repeated to calibrate experimental conditions, particularly in the case where complex wavelength, spatial frequency or polarization encoding is used. We anticipate that this technique will enable previously inaccessible spatiotemporal imaging in a number of fields of ultrafast science at the micro- and nanoscale.
Operando monitoring transition dynamics of responsive polymer using optofluidic microcavities
Authors: Yang Da-Quan , Chen Jin-hui , Cao Qi-Tao , Duan Bing , Chen Hao-Jing , Yu Xiao-Chong , Xiao Yun-Feng 
Published: June 2021

AbstractOptical microcavities have become an attractive platform for precision measurement with merits of ultrahigh sensitivity, miniature footprint and fast response. Despite the achievements of ultrasensitive detection, optical microcavities still face significant challenges in the measurement of biochemical and physical processes with complex dynamics, especially when multiple effects are present. Here we demonstrate operando monitoring of the transition dynamics of a phase-change material via a self-referencing optofluidic microcavity. We use a pair of cavity modes to precisely decouple the refractive index and temperature information of the analyte during the phase-transition process. Through real-time measurements, we reveal the detailed hysteresis behaviors of refractive index during the irreversible phase transitions between hydrophilic and hydrophobic states. We further extract the phase-transition threshold by analyzing the steady-state refractive index change at various power levels. Our technology could be further extended to other materials and provide great opportunities for exploring on-demand dynamic biochemical processes.
A cohort autopsy study defines COVID-19 systemic pathogenesis
Authors: Yao Xiao-Hong , Luo Tao , Shi Yu , He Zhi-Cheng , Tang Rui , Zhang Pei-Pei , Cai Jun , Zhou Xiang-Dong , Jiang Dong-Po , Fei Xiao-Chun , Huang Xue-Quan , Zhao Lei , Zhang Heng , Wu Hai-Bo , Ren Yong , Liu Zhen-Hua , Zhang Hua-Rong , Chen Cong , Fu Wen-Juan , Li Heng , Xia Xin-Yi , Chen Rong , Wang Yan , Liu Xin-Dong , Yin Chang-Lin , Yan Ze-Xuan , Wang Juan , Jing Rui , Li Tai-Sheng , Li Wei-Qin , Wang Chao-Fu , Ding Yan-Qing , Mao Qing , Zhang Ding-Yu , Zhang Shu-Yang , Ping Yi-Fang , Bian Xiu-Wu 
Published: June 2021

AbstractSevere COVID-19 disease caused by SARS-CoV-2 is frequently accompanied by dysfunction of the lungs and extrapulmonary organs. However, the organotropism of SARS-CoV-2 and the port of virus entry for systemic dissemination remain largely unknown. We profiled 26 COVID-19 autopsy cases from four cohorts in Wuhan, China, and determined the systemic distribution of SARS-CoV-2. SARS-CoV-2 was detected in the lungs and multiple extrapulmonary organs of critically ill COVID-19 patients up to 67 days after symptom onset. Based on organotropism and pathological features of the patients, COVID-19 was divided into viral intrapulmonary and systemic subtypes. In patients with systemic viral distribution, SARS-CoV-2 was detected in monocytes, macrophages, and vascular endothelia at blood–air barrier, blood–testis barrier, and filtration barrier. Critically ill patients with long disease duration showed decreased pulmonary cell proliferation, reduced viral RNA, and marked fibrosis in the lungs. Permanent SARS-CoV-2 presence and tissue injuries in the lungs and extrapulmonary organs suggest direct viral invasion as a mechanism of pathogenicity in critically ill patients. SARS-CoV-2 may hijack monocytes, macrophages, and vascular endothelia at physiological barriers as the ports of entry for systemic dissemination. Our study thus delineates systemic pathological features of SARS-CoV-2 infection, which sheds light on the development of novel COVID-19 treatment.
Interaction of schizophrenia and chronic cannabis use on reward anticipation sensitivity
Authors: Fish Simon , Christidi Foteini , Karavasilis Efstratios , Velonakis Georgios , Kelekis Nikolaos , Klein Christoph , Stefanis Nicholas C. , Smyrnis Nikolaos 
Published: June 2021

AbstractChronic cannabis use and schizophrenia are both thought to affect reward processing. While behavioural and neural effects on reward processing have been investigated in both conditions, their interaction has not been studied, although chronic cannabis use is common among these patients. In the present study eighty-nine participants divided into four groups (control chronic cannabis users and non-users; schizophrenia patient cannabis users and non-users) performed a two-choice decision task, preceded by monetary cues (high/low reward/punishment or neutral), while being scanned using functional magnetic resonance imaging. Reward and punishment anticipation resulted in activation of regions of interest including the thalamus, striatum, amygdala and insula. Chronic cannabis use and schizophrenia had opposing effects on reward anticipation sensitivity. More specifically control users and patient non-users showed faster behavioural responses and increased activity in anterior/posterior insula for high magnitude cues compared to control non-users and patient users. The same interaction pattern was observed in the activation of the right thalamus for reward versus punishment cues. This study provided evidence for interaction of chronic cannabis use and schizophrenia on reward processing and highlights the need for future research addressing the significance of this interaction for the pathophysiology of these conditions and its clinical consequences.
Rare CASP6N73T variant associated with hippocampal volume exhibits decreased proteolytic activity, synaptic transmission defect, and neurodegeneration
Authors: Zhou Libin , Nho Kwangsik , Haddad Maria G. , Cherepacha Nicole , Tubeleviciute-Aydin Agne , Tsai Andy P. , Saykin Andrew J. , Jesper Sjöström P. , LeBlanc Andrea C. 
Published: June 2021

AbstractCaspase-6 (Casp6) is implicated in Alzheimer disease (AD) cognitive impairment and pathology. Hippocampal atrophy is associated with cognitive impairment in AD. Here, a rare functional exonic missense CASP6 single nucleotide polymorphism (SNP), causing the substitution of asparagine with threonine at amino acid 73 in Casp6 (Casp6N73T), was associated with hippocampal subfield CA1 volume preservation. Compared to wild type Casp6 (Casp6WT), recombinant Casp6N73T altered Casp6 proteolysis of natural substrates Lamin A/C and α-Tubulin, but did not alter cleavage of the Ac-VEID-AFC Casp6 peptide substrate. Casp6N73T-transfected HEK293T cells showed elevated Casp6 mRNA levels similar to Casp6WT-transfected cells, but, in contrast to Casp6WT, did not accumulate active Casp6 subunits nor show increased Casp6 enzymatic activity. Electrophysiological and morphological assessments showed that Casp6N73T recombinant protein caused less neurofunctional damage and neurodegeneration in hippocampal CA1 pyramidal neurons than Casp6WT. Lastly, CASP6 mRNA levels were increased in several AD brain regions confirming the implication of Casp6 in AD. These studies suggest that the rare Casp6N73T variant may protect against hippocampal atrophy due to its altered catalysis of natural protein substrates and intracellular instability thus leading to less Casp6-mediated damage to neuronal structure and function.
Copper-binding anticancer peptides from the piscidin family: an expanded mechanism that encompasses physical and chemical bilayer disruption
Authors: Comert Fatih , Heinrich Frank , Chowdhury Ananda , Schoeneck Mason , Darling Caitlin , Anderson Kyle W. , Libardo M. Daben J. , Angeles-Boza Alfredo M. , Silin Vitalii , Cotten Myriam L. , Mihailescu Mihaela 
Published: June 2021

AbstractIn the search for novel broad-spectrum therapeutics to fight chronic infections, inflammation, and cancer, host defense peptides (HDPs) have garnered increasing interest. Characterizing their biologically-active conformations and minimum motifs for function represents a requisite step to developing them into efficacious and safe therapeutics. Here, we demonstrate that metallating HDPs with Cu2+is an effective chemical strategy to improve their cytotoxicity on cancer cells. Mechanistically, we find that prepared as Cu2+-complexes, the peptides not only physically but also chemically damage lipid membranes. Our testing ground features piscidins 1 and 3 (P1/3), two amphipathic, histidine-rich, membrane-interacting, and cell-penetrating HDPs that are α-helical bound to membranes. To investigate their membrane location, permeabilization effects, and lipid-oxidation capability, we employ neutron reflectometry, impedance spectroscopy, neutron diffraction, and UV spectroscopy. While P1-apo is more potent than P3-apo, metallation boosts their cytotoxicities by up to two- and seven-fold, respectively. Remarkably, P3-Cu2+is particularly effective at inserting in bilayers, causing water crevices in the hydrocarbon region and placing Cu2+near the double bonds of the acyl chains, as needed to oxidize them. This study points at a new paradigm where complexing HDPs with Cu2+to expand their mechanistic reach could be explored to design more potent peptide-based anticancer therapeutics.
Radiofrequency EMF irradiation effects on pre-B lymphocytes undergoing somatic recombination
Authors: Ioniţă Elena , Marcu Aurelian , Temelie Mihaela , Savu Diana , Şerbănescu Mihai , Ciubotaru Mihai 
Published: June 2021

AbstractIntense electromagnetic fields (EMFs) induce DNA double stranded breaks (DSBs) in exposed lymphocytes.We study developing pre-B lymphocytes following V(D)J recombination at their Immunoglobulin light chain loci (IgL). Recombination physiologically induces DNA DSBs, and we tested if low doses of EMF irradiation affect this developmental stage. Recombining pre-B cells, were exposed for 48 h to low intensity EMFs (maximal radiative power density flux S of 9.5 µW/cm2 and electric field intensity 3 V/m) from waves of frequencies ranging from 720 to 1224 MHz. Irradiated pre-B cells show decreased levels of recombination, reduction which is dependent upon the power dose and most remarkably upon the frequency of the applied EMF. Although 50% recombination reduction cannot be obtained even for an S of 9.5 µW/cm2 in cells irradiated at 720 MHz, such an effect is reached in cells exposed to only 0.45 µW/cm2 power with 950 and 1000 MHz waves. A maximal four-fold recombination reduction was measured in cells exposed to 1000 MHz waves with S from 0.2 to 4.5 µW/cm2 displaying normal levels of γH2AX phosphorylated histone. Our findings show that developing B cells exposure to low intensity EMFs can affect the levels of production and diversity of their antibodies repertoire.
Acoustic hologram optimisation using automatic differentiation
Authors: Fushimi Tatsuki , Yamamoto Kenta , Ochiai Yoichi 
Published: June 2021

AbstractAcoustic holograms are the keystone of modern acoustics. They encode three-dimensional acoustic fields in two dimensions, and their quality determines the performance of acoustic systems. Optimisation methods that control only the phase of an acoustic wave are considered inferior to methods that control both the amplitude and phase of the wave. In this paper, we present Diff-PAT, an acoustic hologram optimisation platform with automatic differentiation. We show that in the most fundamental case of optimizing the output amplitude to match the target amplitude; our method with only phase modulation achieves better performance than conventional algorithm with both amplitude and phase modulation. The performance of Diff-PAT was evaluated by randomly generating 1000 sets of up to 32 control points for single-sided arrays and single-axis arrays. This optimisation platform for acoustic hologram can be used in a wide range of applications of PATs without introducing any changes to existing systems that control the PATs. In addition, we applied Diff-PAT to a phase plate and achieved an increase of > 8 dB in the peak noise-to-signal ratio of the acoustic hologram.
Silver nanoparticles produced from Cedecea sp. exhibit antibiofilm activity and remarkable stability
Authors: Singh Priyanka , Pandit Santosh , Jers Carsten , Joshi Abhayraj S. , Garnæs Jørgen , Mijakovic Ivan 
Published: June 2021

AbstractWith multidrug-resistant bacterial pathogens on the rise, there is a strong research focus on alternative antibacterial treatments that could replace or complement classical antibiotics. Metallic nanoparticles, and in particular silver nanoparticles (AgNPs), have been shown to kill bacterial biofilms effectively, but their chemical synthesis often involves environmentally unfriendly by-products. Recent studies have shown that microbial and plant extracts can be used for the environmentally friendly synthesis of AgNPs. Herein we report a procedure for producing AgNPs using a putative Cedecea sp. strain isolated from soil. The isolated bacterial strain showed a remarkable potential for producing spherical, crystalline and stable AgNPs characterized by UV–visible spectroscopy, transmission electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. The concentration of produced nanoparticles was 1.31 µg/µl with a negative surface charge of − 15.3 mV and nanoparticles size ranging from 10–40 nm. The AgNPs was tested against four pathogenic microorganisms S. epidermidis, S. aureus, E. coli and P. aeruginosa. The nanoparticles exhibited strong minimum inhibitory concentration (MIC) values of 12.5 and 6.25 µg/µl and minimum bactericidal concentration (MBC) values of 12.5 and 12.5 µg/mL against E. coli and P. aeruginosa, respectively. One distinguishing feature of AgNPs produced by Cedecea sp. extracts is their extreme stability. Inductively coupled plasma mass spectrometry and thermogravimetric analysis demonstrated that the produced AgNPs are stable for periods exceeding one year. This means that their strong antibacterial effects, demonstrated against E. coli and P. aeruginosa biofilms, can be expected to persist during extended periods.
Single-layer phase gradient mmWave metasurface for incident angle independent focusing
Authors: Lee Wonwoo , Jo Semin , Lee Kanghyeok , Park Hong Soo , Yang Junhyuk , Hong Ha Young , Park Changkun , Hong Sun K. , Lee Hojin 
Published: June 2021

AbstractMetasurfaces allow the rapid development of compact and flat electromagnetic devices owing to their capability in manipulating the wavefront of electromagnetic waves. Particularly, with respect to the metasurface lenses, wide operational bandwidth and wide incident angle behavior are critically required for practical applications. Herein, a single-layer phase gradient metasurface lens is presented to achieve millimeter-wave focusing at a focal point of 13 mm regardless of the incident angle. The proposed metasurface lens is fabricated by constructing subwavelength-thick (< λ/10) phase elements composed of two metallic layers separated by a single dielectric substrate that exhibits low-Q resonance properties and a wide phase modulation range with satisfactory transmissivity. By controlling the spatial phase distribution, the proposed metasurface lens successfully realises effective wavefront manipulation properties and high-performance electromagnetic-wave-focusing characteristics over a wide operating frequency range from 35 to 40 GHz with incident angle independency up to 30°.
Water vapor sorption behavior of bamboo pertaining to its hierarchical structure
Authors: Chen Qi , Fang Changhua , Wang Ge , Ma Xinxin , Luo Junji , Chen Meiling , Dai Chunping , Fei Benhua 
Published: June 2021

AbstractBamboo is an anisotropic, hierarchical, and hygroscopic material. Moisture transport in bamboo is one of the most fundamental properties affecting almost all other physical and mechanical properties of the material. This study investigated the water vapor sorption behaviors of bamboo at various structural levels: cell walls, cells (with pits) and bamboo blocks. The specimens with two sorption directions, longitudinal (L) and transverse (T), were measured by saturated salt solution method and dynamic vapor sorption. The parallel exponential kinetics model was used to analyze the sorption kinetics. The results showed that at the cell wall level, the sorption rate and equilibrium moisture content (EMC) of cell wall in the L specimens were larger than those in the T specimens. The differences were probably caused by the looser cell wall layers in the L specimens. At the cellular scale, pits in the cell wall resulted in an enhanced sorption rate and EMC of the T specimens compared with the L specimens where the pits in the parenchyma cells were only distributed in the lateral walls but not in end walls. At the macro scale, the sorption rate and moisture content of bamboo blocks were largely controlled by the vessel cells. As a hierarchically-structured plant, bamboo performs the biological function of moisture transport at all these scales. This work helps improve the understanding of water transport behavior in bamboo, which may lead to better bamboo drying and impregnation processes.
Development and validation of an individualized immune prognostic model in stage I–III lung squamous cell carcinoma
Authors: Yang Qi-Fan , Wu Di , Wang Jian , Ba Li , Tian Chen , Liu Yu-Ting , Hu Yue , Liu Li 
Published: June 2021

AbstractLung squamous cell carcinoma (LUSC) possesses a poor prognosis even for stages I–III resected patients. Reliable prognostic biomarkers that can stratify and predict clinical outcomes for stage I–III resected LUSC patients are urgently needed. Based on gene expression of LUSC tissue samples from five public datasets, consisting of 687 cases, we developed an immune-related prognostic model (IPM) according to immune genes from ImmPort database. Then, we comprehensively analyzed the immune microenvironment and mutation burden that are significantly associated with this model. According to the IPM, patients were stratified into high- and low-risk groups with markedly distinct survival benefits. We found that patients with high immune risk possessed a higher proportion of immunosuppressive cells such as macrophages M0, and presented higher expression of CD47, CD73, SIRPA, and TIM-3. Moreover, When further stratified based on the tumor mutation burden (TMB) and risk score, patients with high TMB and low immune risk had a remarkable prolonged overall survival compared to patients with low TMB and high immune risk. Finally, a nomogram combing the IPM with clinical factors was established to provide a more precise evaluation of prognosis. The proposed immune relevant model is a promising biomarker for predicting overall survival in stage I–III LUSC. Thus, it may shed light on identifying patient subset at high risk of adverse prognosis from an immunological perspective.