bluuebunny/crossref_metadata_2025 huggingface dataset:
Fate of nanoparticles in the central nervous system after intrathecal injection in healthy mice
Authors: Householder K. T. , Dharmaraj S. , Sandberg D. I. , Wechsler-Reya R. J. , Sirianni R. W.
Published: August 2019

Cerebrospinal fluid (CSF) is produced in the cerebral ventricles and circulates within the subarachnoid space (SAS) of the brain and spinal cord, where it exchanges with interstitial fluid of the parenchyma. The access of CSF to the entire central nervous system (CNS) makes it an attractive medium for drug delivery. However, few intrathecal (IT) therapies have reached the clinic due, in part, to limited distribution and rapid clearance. Given the success of nanoparticle (NP) carriers in prolonging circulation and improving delivery of systemically administered agents, we sought to evaluate the distribution of IT injected NPs within the CNS. We administered fluorescent, 100 nm PEGylated-NPs into the cisterna magna of healthy mice and studied their distribution along the brain and spinal cord. Our data demonstrate that NPs are capable of distributing rapidly through the SAS along the entire neuraxis with reproducible, anatomically defined patterns of delivery. NPs were well retained within the leptomeninges for over 3 weeks, showing preference for ventral surfaces and minimal penetration into the CNS parenchyma. Clearance of NPs occurred across the cribriform plate into the nasal mucosa, with a small fraction of NPs localizing with nerve roots exiting the spinal column. Larger 10 µm particles were also capable of moving through the SAS but did not achieve as widespread distribution. These studies demonstrate the ability of NPs to achieve widespread delivery along the neuraxis and highlight IT administration as a potentially significant route of administration for delivery of nanomedicine to the subarachnoid space.
Bilateral temporal control determines mediolateral margins of stability in symmetric and asymmetric human walking
Authors: Buurke Tom J. W. , Lamoth Claudine J. C. , van der Woude Lucas H. V. , Hof At L. , den Otter Rob
Published: August 2019

Human bipedal gait requires active control of mediolateral dynamic balance to stay upright. The margin of stability is considered a measure of dynamic balance, and larger margins are by many authors assumed to reflect better balance control. The inverted pendulum model of gait indicates that changes in the mediolateral margin of stability are related to changes in bilateral single support times. We propose updated equations for the mediolateral margin of stability in temporally symmetric and asymmetric gait, which now include the single support times of both legs. Based on these equations, we study the relation between bilateral single support times and the mediolateral margin of stability in symmetric, asymmetric, and adaptive human gait. In all conditions, the mediolateral margin of stability during walking followed predictably from bilateral single support times, whereas foot placement co-varied less with the mediolateral margin of stability. Overall, these results demonstrate that the bilateral temporal regulation of gait profoundly affects the mediolateral margin of stability. By exploiting the passive dynamics of bipedal gait, bilateral temporal control may be an efficient mechanism to safeguard dynamic stability during walking, and keep an inherently unstable moving human body upright.
Evidence of CD40L/CD40 pathway involvement in experimental transfusion-related acute lung injury
Authors: Tariket Sofiane , Hamzeh-Cognasse Hind , Laradi Sandrine , Arthaud Charles-Antoine , Eyraud Marie-Ange , Bourlet Thomas , Berthelot Philippe , Garraud Olivier , Cognasse Fabrice
Published: August 2019

Platelet transfusions can cause adverse reactions in their recipients, including transfusion-related acute lung injury (TRALI). The pathophysiology of TRALI depends on a number of signaling pathways and the inflammatory role played by blood platelets remains controversial. Platelets are important in inflammation, particularly via the immunomodulator complex CD40/CD40L. We studied the specific function of the CD40/CD40L interaction in regulating an experimental TRALI Two-hit model. A mouse model of immune TRALI was triggered by injection of LPS and an anti-MHC I antibody, and the effect of injection of a neutralizing anti-CD40L antibody before induction of TRALI investigated. The characteristics of TRALI were decreased body temperature, pulmonary lesions, and immune cell infiltration into the alveolar space. Pulmonary infiltration was evaluated by blood counts of specific immune cells and their detection in lung sections. Inhibition of the CD40/CD40L immunomodulator interaction significantly reduced communication between immune and/or endothelial cells and the development of pulmonary edema. Hence, our results indicate that targeting of the CD40/CD40L interaction could be an important method to prevent TRALI. While considering that our work concerned a mouse model, we postulate that improvement of the conditions under which platelet concentrates are prepared/stored would assist in alleviating the risk of TRALI.
TGF-β1 increases viral burden and promotes HIV-1 latency in primary differentiated human bronchial epithelial cells
Authors: Chinnapaiyan S. , Dutta R. K. , Nair M. , Chand H. S. , Rahman I. , Unwalla H. J.
Published: August 2019

Combination antiretroviral therapy (cART) has increased the life expectancy of HIV patients. However, the incidence of non-AIDS associated lung comorbidities, such as COPD and asthma, and that of opportunistic lung infections have become more common among this population. HIV proteins secreted by the anatomical HIV reservoirs can have both autocrine and paracrine effects contributing to the HIV-associated comorbidities. HIV has been recovered from cell-free bronchoalveolar lavage fluid, alveolar macrophages, and intrapulmonary lymphocytes. We have recently shown that ex-vivo cultured primary bronchial epithelial cells and the bronchial brushings from human subjects express canonical HIV receptors CD4, CCR5 and CXCR4 and can be infected with HIV. Together these studies suggest that the lung tissue can serve as an important reservoir for HIV. In this report, we show that TGF-β1 promotes HIV latency by upregulating a transcriptional repressor BLIMP-1. Furthermore, we identify miR-9-5p as an important intermediate in TGF-β-mediated BLIMP-1 upregulation and consequent HIV latency. The transcriptionally suppressed HIV can be reactivated by common latency reactivating agents. Together our data suggest that in patients with chronic airway diseases, TGF-β can elevate the HIV viral reservoir load that could further exacerbate the HIV associated lung comorbidities.
Microfluidics Chip for Directional Solvent Extraction Desalination of Seawater
Authors: Abdulbari Hayder A. , Basheer Esmail A. M.
Published: August 2019

Directional solvent extraction is one of the promising membrane-less seawater desalination method. This technique was not extensively investigated due the poor mixing and separation performances of its bench-scale system. It is believed that, overcoming these drawbacks is possible now with the rapid development of microfluidics technology that enabled high-precession micro mixing and separation. This work presents microfluidics chip for extracting and separating salt from seawater. The chip was designed with two sections for extraction and separation. In both sections, the liquids were separated using capillary channels perpendicular to the main stream. The main channels were designed to be 400 µm in width and 100 µm in height. Two streams inlets were introduced through a Y-junction containing octanoic acid as the organic phase and saltwater as the aqueous phase. The desalination performance was investigated at four different temperatures and five different solvent flow rates. Water product salinity was recorded to be as low as 0.056% (w/w) at 60 °C and 40 mL/h. A maximum water yield of 5.2% was achieved at 65 °C and 40 mL/h with a very low solvent residual (70 ppm). The chip mass transfer efficiency was recorded to be as high as 68% under similar conditions. The fabricated microfluidic desalination system showed a significant improvement in terms of water yield and separation efficiency over the conventional macroscale. The high performance of this microsystem resulted from its ability to achieve a high mixing efficiency and separate phases selectively and that will provide a good platform in the near future to develop small desalination kits for personal use.
Phenotypic switching in Candida tropicalis alters host-pathogen interactions in a Galleria mellonella infection model
Authors: Perini Hugo F. , Moralez Alane T. P. , Almeida Ricardo S. C. , Panagio Luciano A. , Junior Admilton O. G. , Barcellos Fernando Gomes , Furlaneto-Maia Luciana , Furlaneto Marcia C.
Published: August 2019

Candida tropicalis is a human pathogen associated with high mortality rates. We have reported a switching system in C. tropicalis consisting of five morphotypes – the parental, switch variant (crepe and rough), and revertant (crepe and rough) strains, which exhibited altered virulence in a Galleria mellonella model. Here, we evaluate whether switching events may alter host-pathogen interactions by comparing the attributes of the innate responses to the various states. All switched strains induced higher melanization in G. mellonella larvae than that induced by the parental strain. The galiomicin expression was higher in the larvae infected with the crepe and rough morphotypes than that in the larvae infected with the parental strain. Hemocytes preferentially phagocytosed crepe variant cells over parental cells in vitro. In contrast, the rough variant cells were less phagocytosed than the parental strain. The hemocyte density was decreased in the larvae infected with the crepe variant compared to that in the larvae infected with the parental strain. Interestingly, larvae infected with the revertant of crepe restored the hemocyte density levels that to those observed for larvae infected with the parental strain. Most of the switched strains were more resistant to hemocyte candidacidal activity than the parental strain. These results indicate that the switch states exhibit similarities as well as important differences during infection in a G. mellonella model.
Permeability enhancement through hydraulic fracturing: laboratory measurements combining a 3D printed jacket and pore fluid over-pressure
Authors: Gehne Stephan , Benson Philip M.
Published: August 2019

The process of hydraulic fracture is well known in both natural (e.g. veining and mineralisation) and engineered environments (e.g. stimulating tight mudrocks and sandstones to boost their hydraulic properties). Here, we report a method and preliminary data that simulates both tensile fracture and fluid flow at elevated pressures. To achieve this we developed a sample assembly consisting of a cylindrical core drilled with an axial borehole encapsulated in a 3D printed jacket permitting fluid from the borehole to move through the freshly generated tensile fracture to a voluometer. The permeability of Nash Point Shale increases from a pre-fracture value of 10−18 to 10−20 m2 (1 microDarcy, μD to 0.01 μD) to 2 × 10−15 m2 (2 milliDarcy, mD) immediately after fracture (at 2.1 MPa confining pressure). Permeability is strongly dependent on confining pressure, decreasing to 0.25 × 10−15 m2 (0.25 mD) at 19 MPa confining pressure (approximately 800 m depth), and does not recover when confinement is removed. Using concomitant measurements of the radial strain as a proxy for fracture aperture, we conclude that the effective permeability is governed solely by the width of the developed cracks, revealed by post-test X-Ray Computed Tomography to be planar, extending radially from the central conduit.
Miltefosine treatment reduces visceral hypersensitivity in a rat model for irritable bowel syndrome via multiple mechanisms
Authors: Botschuijver Sara , van Diest Sophie A. , van Thiel Isabelle A. M. , Saia Rafael S. , Strik Anne S. , Yu Zhumei , Maria-Ferreira Daniele , Welting Olaf , Keszthelyi Daniel , Jennings Gary , Heinsbroek Sigrid E. M. , Elferink Ronald P. Oude , Schuren Frank H. J. , de Jonge Wouter J. , van den Wijngaard René M.
Published: August 2019

Irritable bowel syndrome (IBS) is a heterogenic, functional gastrointestinal disorder of the gut-brain axis characterized by altered bowel habit and abdominal pain. Preclinical and clinical results suggested that, in part of these patients, pain may result from fungal induced release of mast cell derived histamine, subsequent activation of sensory afferent expressed histamine-1 receptors and related sensitization of the nociceptive transient reporter potential channel V1 (TRPV1)-ion channel. TRPV1 gating properties are regulated in lipid rafts. Miltefosine, an approved drug for the treatment of visceral Leishmaniasis, has fungicidal effects and is a known lipid raft modulator. We anticipated that miltefosine may act on different mechanistic levels of fungal-induced abdominal pain and may be repurposed to IBS. In the IBS-like rat model of maternal separation we assessed the visceromotor response to colonic distension as indirect readout for abdominal pain. Miltefosine reversed post-stress hypersensitivity to distension (i.e. visceral hypersensitivity) and this was associated with differences in the fungal microbiome (i.e. mycobiome). In vitro investigations confirmed fungicidal effects of miltefosine. In addition, miltefosine reduced the effect of TRPV1 activation in TRPV1-transfected cells and prevented TRPV1-dependent visceral hypersensitivity induced by intracolonic-capsaicin in rat. Miltefosine may be an attractive drug to treat abdominal pain in IBS.
Evaluation of toll-like receptors as prognostic biomarkers in gastric cancer: high tissue TLR5 predicts a better outcome
Authors: Kasurinen Aaro , Hagström Jaana , Laitinen Alli , Kokkola Arto , Böckelman Camilla , Haglund Caj
Published: August 2019

Toll-like receptors (TLRs), key proteins in innate immunity, appear to contribute to the inflammatory environment in carcinogenesis. Thus, we aimed to evaluate the tissue expressions of TLR1, TLR2, TLR4, TLR5, TLR7, and TLR9 as potential prognostic biomarkers in gastric cancer. We applied immunohistochemistry to study tissue samples from 313 patients operated on for gastric adenocarcinoma between 2000 and 2009 at the Department of Surgery, Helsinki University Hospital, Finland. A high expression of each TLR studied associated with the high expression of each other and with the intestinal-type histology (p < 0.001 for all). Five-year disease-specific survival among patients with a high TLR5 was 53.4% (95% confidence interval [CI] 43.4–63.4), whereas among patients with a low TLR5 it was 37.6% (95% CI 30.0–45.2; p = 0.014). A high TLR5 expression functioned as a marker of a better prognosis, particularly among those with a stage II disease (hazard ratio [HR] 0.33; 0.13–0.83; p = 0.019) or an intestinal-type cancer (HR 0.58; 95% CI 0.34–0.98; p = 0.043). In this study we show, for the first time, that a high TLR5 tissue expression may identify gastric cancer patients with a better prognosis, particularly among those with a stage II disease or an intestinal-type cancer.
Fundamental differences in patterns of retinal ageing between primates and mice
Authors: Kam Jaimie Hoh , Weinrich Tobias W. , Shinhmar Harpreet , Powner Michael B. , Roberts Nicholas W. , Aboelnour Asmaa , Jeffery Glen
Published: August 2019

Photoreceptors have high metabolic demands and age rapidly, undermining visual function. We base our understanding mainly on ageing mice where elevated inflammation, extracellular deposition, including that of amyloid beta, and rod and cone photoreceptor loss occur, but cones are not lost in ageing primate although their function declines, revealing that primate and mouse age differently. We examine ageing primate retinae and show elevated stress but low inflammation. However, aged primates have a >70% reduction in adenosine triphosphate (ATP) and a decrease in cytochrome c oxidase. There is a shift in cone mitochondrial positioning and glycolytic activity increases. Bruch’s membrane thickens but unlike in mice, amyloid beta is absent. Hence, reduced ATP may explain cone functional decline in ageing but their retained presence offers the possibility of functional restoration if they can be fuelled appropriately to restore cellular function. This is important because as humans we largely depend on cone function to see and are rarely fully dark adapted. Presence of limited aged inflammation and amyloid beta deposition question some of the therapeutic approaches taken to resolve problems of retinal ageing in humans and the possible lack of success in clinical trials in macular degeneration that have targeted inflammatory agents.
AgBiS2-TPP nanocomposite for mitochondrial targeting photodynamic therapy, photothermal therapy and bio-imaging under 808 nm NIR laser irradiation
Authors: Sun Mingdi , Yang Dan , Wang Chen , Bi Huiting , Zhou Yuan , Wang Xiangxi , Xu Jiating , He Fei , Gai Shili , Yang Piaoping
Published: August 2019

AgBiS2 nanodots as an NIR light-excited photosensitizer produce a PDT effect, which is reported for the first time.
Bioinorganic chemistry of calcitermin – the picklock of its antimicrobial activity
Authors: Bellotti Denise , Toniolo Mattia , Dudek Dorota , Mikołajczyk Aleksandra , Guerrini Remo , Matera-Witkiewicz Agnieszka , Remelli Maurizio , Rowińska-Żyrek Magdalena
Published: August 2019

Formation equilibria of Zn(ii) and Cu(ii) complexes of antimicrobial calcitermin and its mutants are studied; impressive MIC breakpoints are obtained.
A monothiophene unit incorporating both fluoro and ester substitution enabling high-performance donor polymers for non-fullerene solar cells with 16.4% efficiency
Authors: Sun Huiliang , Liu Tao , Yu Jianwei , Lau Tsz-Ki , Zhang Guangye , Zhang Yujie , Su Mengyao , Tang Yumin , Ma Ruijie , Liu Bin , Liang Jiaen , Feng Kui , Lu Xinhui , Guo Xugang , Gao Feng , Yan He
Published: August 2019

Both fluorine and ester substituted monothiophene yielded a novel thiophene derivative FE-T. The resulting polymer donor S1 enabled single-junction non-fullerene solar cell with over 16% efficiency.
Preclinical studies on metal based anticancer drugs as enabled by integrated metallomics and metabolomics
Authors: Galvez Luis , Rusz Mate , Schwaiger-Haber Michaela , El Abiead Yasin , Hermann Gerrit , Jungwirth Ute , Berger Walter , Keppler Bernhard K , Jakupec Michael A , Koellensperger Gunda
Published: August 2019

Resistance development is a major obstacle for platinum-based chemotherapy, with the anticancer drug oxaliplatin being no exception. Acquired resistance is often associated with altered drug accumulation. In this work we introduce a novel -omics workflow enabling the parallel study of platinum drug uptake and its distribution between nucleus/protein and small molecule fraction along with metabolic changes after different treatment time points. This integrated metallomics/metabolomics approach is facilitated by a tailored sample preparation workflow suitable for preclinical studies on adherent cancer cell models. Inductively coupled plasma mass spectrometry monitors the platinum drug, while the metabolomics tool-set is provided by hydrophilic interaction liquid chromatography combined with high-resolution Orbitrap mass spectrometry. The implemented method covers biochemical key pathways of cancer cell metabolism as shown by a panel of >130 metabolite standards. Furthermore, the addition of yeast-based 13C-enriched internal standards upon extraction enabled a novel targeted/untargeted analysis strategy. In this study we used our method to compare an oxaliplatin sensitive human colon cancer cell line (HCT116) and its corresponding resistant model. In the acquired oxaliplatin resistant cells distinct differences in oxaliplatin accumulation correlated with differences in metabolomic rearrangements. Using this multi-omics approach for platinum-treated samples facilitates the generation of novel hypotheses regarding the susceptibility and resistance towards oxaliplatin.
Broadband nonlinear absorption properties of two-dimensional hexagonal tellurene nanosheets
Authors: Zhang Fang , Liu Guowei , Wang Zhengping , Tang Tianhong , Wang Xinle , Wang Chaowei , Fu Shenggui , Xing Fei , Han Kezhen , Xu Xinguang
Published: August 2019

Low saturable intensity, large TPA coefficient and the absorption cross-section demonstrate that tellurene is an advanced broadband nonlinear absorption material and has potential applications in the nonlinear optics field, especially in the infrared band.
Janus micromotors for motion-capture-lighting of bacteria
Authors: Zhao Long , Xie Songzhi , Liu Yuan , Liu Qingjie , Song Xiaojie , Li Xiaohong
Published: August 2019

The rapid and sensitive identification of bacteria has long been a major challenge in quality control, environmental monitoring and food safety.
Natural diterpene pyrones: chemistry and biology
Authors: Al-Khdhairawi Amjad Ayad Qatran , Cordell Geoffrey A. , Thomas Noel F. , Shivanagere Nagojappa Narendra Babu , Weber Jean-Frédéric F.
Published: August 2019

Diterpene pyrones (DTPs) are a group of well-known, mainly fungal, natural products, first isolated in 1966.
Expanding the monomer scope of linear and branched vinyl polymerisations via copper-catalysed reversible-deactivation radical polymerisation of hydrophobic methacrylates using anhydrous alcohol solvents
Authors: Flynn Sean , Dwyer Andrew B. , Chambon Pierre , Rannard Steve
Published: August 2019

The use of anhydrous alcohols for Cu-catalysed reversible-deactivation radical polymerisation of a wide range of hydrophobic methacrylates has been explored in detail.
The synthesis and oligomerization of a monofunctional bottlebrush-shaped polymer terminated with an azide group
Authors: Wang Youfu , Li Rui , Bian Yawen , Zhang Xueli , Zhu Xinyuan
Published: August 2019

A monofunctional bottlebrush-shaped polymer terminated with an azide group and its oligomers (dimer, trimer) were synthesized in a controlled manner and directly visualized.
Fabrication of a Z-scheme AgBr/Bi4O5Br2nanocomposite and its high efficiency in photocatalytic N2fixation and dye degradation
Authors: Chen Yijing , Zhao Chunran , Ma Sanan , Xing Pingxing , Hu Xin , Wu Ying , He Yiming
Published: August 2019

Z-scheme AgBr/Bi4O5Br2nanocomposite was synthesizedviaa simple ion-exchange method and firstly applied in photocatalytic N2fixation under simulated sunlight.
Hybrid isoquinolines from Thalictrum foetidum: a new type of aporphine inhibiting Staphylococcus aureus by combined mechanisms
Authors: Ding Cai-Feng , Zhang Rong-Ping , Yu Hao-Fei , Yang Jing , Qin Xu-Jie , Dai Zhi , Liu Ya-Ping , Lu Qiu-Min , Lai Ren , Luo Xiao-Dong
Published: August 2019

Thalfoetines A–D (1–4), unique hybrid aporphine alkaloids with a C-7 aromatic unit formed by a new C–C bond linking two building blocks, were isolated from Thalictrum foetidum.
Pd/P/dba-Promoted cascade annulations to produce fused medium-sized sulfoximine polyheterocycles
Authors: Chen Xiaoyan , Zhou Hao , Chen Zhiyuan
Published: August 2019

The Pd-catalyzed multicomponent reactions of NH-sulfoximine, aryl iodide and norbornadiene (NBD) are reported to chemoselectively produce fused medium-sized sulfoximine polyheterocycles in good to excellent yields.
Tuning the Biginelli reaction mechanism by the ionic liquid effect: the combined role of supported heteropolyacid derivatives and acidic strength
Authors: Freitas Elon F. , Souza Roberto Y. , Passos Saulo T. A. , Dias José A. , Dias Silvia C. L. , Neto Brenno A. D.
Published: August 2019

Heteropolyacids and ionic liquid effect allowed tuning of the Biginelli reaction mechanism and synthesis of 3,4-dihydropyrimidin-2(1H)-one/thione derivatives in an efficient, recyclable fashion. The role of acidic strength and supported heteropolyacid is disclosed.
Sarcoehrenbergilides D–F: cytotoxic cembrene diterpenoids from the soft coral Sarcophyton ehrenbergi
Authors: Hegazy Mohamed-Elamir F. , Mohamed Tarik A. , Elshamy Abdelsamed I. , Hamed Ahmed R. , Ibrahim Mahmoud A. A. , Ohta Shinji , Umeyama Akemi , Paré Paul W. , Efferth Thomas
Published: August 2019

A solvent extract of the soft coral Sarcophyton ehrenbergi afforded cembrene diterpenoids, sarcoehrenbergilid D–F (1–3).
Three-dimensional DNA nanostructures to improve the hyperbranched hybridization chain reaction
Authors: Wang Jing , Wang Dong-Xia , Ma Jia-Yi , Wang Ya-Xin , Kong De-Ming
Published: August 2019

Nonenzymatic nucleic acid amplification techniques (e.g. the hybridization chain reaction, HCR) have shown promising potential for amplified detection of biomarkers.
Influence of the distal guanidine group on the rate and selectivity of O2 reduction by iron porphyrin
Authors: Ghatak Arnab , Bhakta Snehadri , Bhunia Sarmistha , Dey Abhishek
Published: August 2019

The O2 reduction reaction (ORR) catalysed by iron porphyrins with covalently attached pendant guanidine groups is reported.
A proof-reading mechanism for non-proteinogenic amino acid incorporation into glycopeptide antibiotics
Authors: Kaniusaite Milda , Tailhades Julien , Marschall Edward A. , Goode Robert J. A. , Schittenhelm Ralf B. , Cryle Max J.
Published: August 2019

A complex interplay of non-ribosomal peptide synthetase domains works together with trans-acting enzymes to ensure effective GPA biosynthesis.
Granular ionic crystals in a small nutshell
Authors: Haeberle Jan , Harju Janni , Sperl Matthias , Born Philip
Published: August 2019

Binary mixtures of granular particles take arrangements akin ionic crystals by triboelectric charging in incommensurate containers, but not in commensurate containers.
A high-energy potassium–sulfur battery enabled by facile and effective imidazole-solvated copper catalysts
Authors: Lai Nien-Chu , Cong Guangtao , Lu Yi-Chun
Published: August 2019

An imidazole-solvated-copper catalyst was developed to promote K2S-formation in K–S batteries achieving 922 mA h gS−1 and 1.93 V cell voltage.
Highly active and durable double-doped bismuth oxide-based oxygen electrodes for reversible solid oxide cells at reduced temperatures
Authors: Yun Byung-Hyun , Kim Kyeong Joon , Joh Dong Woo , Chae Munseok S. , Lee Jong Jun , Kim Dae-won , Kang Seokbeom , Choi Doyoung , Hong Seung-Tae , Lee Kang Taek
Published: August 2019

Highly conductive Dy and Y co-doped bismuth oxides combined with La0.8Sr0.2MnO3−δsignificantly enhanced the ORR and OER as oxygen electrodes for reversible SOCs.
Suppression of benzophenone-induced triplet quenching for enhanced TADF performance
Authors: Kreiza Gediminas , Banevičius Dovydas , Jovaišaitė Justina , Maleckaitė Karolina , Gudeika Dalius , Volyniuk Dmytro , Gražulevičius Juozas V. , Juršėnas Saulius , Kazlauskas Karolis
Published: August 2019

An effective way to suppress non-radiative triplet quenching and enhance rISC up to 100% in benzophenone-derived blue TADF emitters is proposed.
Strategic modification of ligands for remarkable piezochromic luminescence (PCL) based on a neutral Ir(iii) phosphor
Authors: Li Dan , Li Guangfu , Xie Jiaxin , Zhu Dongxia , Su Zhongmin , Bryce Martin R.
Published: August 2019

A neutral Ir(iii) complex has been synthesized by introducing a carboxyl group and fluorine substituents into the ligands to construct a new piezochromic luminescence (PCL) active material.
Sulfur-fused perylene diimide electron transport layers allow >400 h operational lifetime of methylammonium lead iodide photovoltaics
Authors: Nakayama Hidenori , Zheng Yonghao , Schneider Julia A. , Wang Hengbin , Ninomiya Naoya , Momose Tatsuya , Read de Alaniz Javier , Wudl Fred , Chabinyc Michael L.
Published: August 2019

The lifetime of hybrid organic perovskite solar cells under 1 sun illumination can be extended using electron transport layers made with fused perylene diimide acceptors with disulfide moieties.
MiR-34b inhibits the proliferation and promotes apoptosis in colon cancer cells by targeting Wnt/β-catenin signaling pathway
Authors: Ye Kailun , Xu Chunhua , Hui Tongguan
Published: August 2019

Colon cancer is one of the leading cause of cancer deaths that is severely threatening human health. Several microRNAs (miRNAs) have been found to be associated with the tumor genesis of colon cancer. The present study determined the expression of miR-34b in patients with colon cancer and studied the molecular mechanism of miR-34b in the proliferation and apoptosis of human colon cancer Caco-2 cells in vitro. In colon cancer patients, the expression of miR-34b was decreased in tumor tissues when compared with the adjacent non-tumor tissues. Furthermore, overexpression of miR-34b inhibited proliferation, migration and invasion, while promoted apoptosis in colon cancer cells. The online bioinformatics sites predicted possible regulatory genes of miR-34b and luciferase reporter assay verify that β-catenin was a direct target of miR-34b. Furthermore, miR-34b overexpression significantly decreased the expression of genes associated with Wnt/β-catenin signaling pathway. In conclusion, our results suggest that miR-34b may inhibit migration and invasion of human colon cancer cells by regulating Wnt/β-catenin signaling and miR-34b may be a key target for the treatment and diagnosis of colon cancer.
Neuroanatomical Correlates of Childhood Stuttering: MRI Indices of White and Gray Matter Development That Differentiate Persistence Versus Recovery
Authors: Garnett Emily O. , Chow Ho Ming , Chang Soo-Eun
Published: August 2019

Purpose

We review two recent neuroanatomical studies of children who stutter (CWS), one that examines white matter integrity and the other that focuses on cortical gray matter morphology. In both studies, we sought to examine differences between children whose stuttering persists (“persistent”), children who recovered from stuttering (“recovered”), and their nonstuttering peers (“controls”).

Method

Both of the reviewed studies use data from a large pediatric sample spanning preschool- to school-age children (3–10 years old at initial testing). Study 1 focused on surface-based measures of cortical size (thickness) and shape (gyrification) using structural magnetic resonance imaging, whereas Study 2 utilized diffusion tensor imaging to examine white matter integrity.

Results

In both studies, the main difference that emerged between CWS and fluent peers encompassed left hemisphere speech motor areas that are interconnected via the arcuate fasciculus. In the case of white matter integrity, the temporoparietal junction and posterior superior temporal gyrus, both connected via the left arcuate fasciculus, and regions along the corpus callosum that contain fibers connecting bilateral motor regions were significantly decreased in white matter integrity in CWS compared to controls. In the morphometric study, children who would go on to have persistent stuttering specifically had lower cortical thickness in ventral motor and premotor areas of the left hemisphere.

Conclusion

These results point to aberrant development of cortical areas involved in integrating sensory feedback with speech movements in CWS and differences in interhemispheric connectivity between the two motor cortices. Furthermore, developmental trajectories in these areas seem to diverge between persistent and recovered cases.
Limited Pre-Speech Auditory Modulation in Individuals Who Stutter: Data and Hypotheses
Authors: Max Ludo , Daliri Ayoub
Published: August 2019

Purpose

We review and interpret our recent series of studies investigating motor-to-auditory influences during speech movement planning in fluent speakers and speakers who stutter. In those studies, we recorded auditory evoked potentials in response to probe tones presented immediately prior to speaking or at the equivalent time in no-speaking control conditions. As a measure of pre-speech auditory modulation (PSAM), we calculated changes in auditory evoked potential amplitude in the speaking conditions relative to the no-speaking conditions. Whereas adults who do not stutter consistently showed PSAM, this phenomenon was greatly reduced or absent in adults who stutter. The same between-group difference was observed in conditions where participants expected to hear their prerecorded speech played back without actively producing it, suggesting that the speakers who stutter use inefficient forward modeling processes rather than inefficient motor command generation processes. Compared with fluent participants, adults who stutter showed both less PSAM and less auditory–motor adaptation when producing speech while exposed to formant-shifted auditory feedback. Across individual participants, however, PSAM and auditory–motor adaptation did not correlate in the typically fluent group, and they were negatively correlated in the stuttering group. Interestingly, speaking with a consistent 100-ms delay added to the auditory feedback signal–normalized PSAM in speakers who stutter, and there no longer was a between-group difference in this condition.

Conclusions

Combining our own data with human and animal neurophysiological evidence from other laboratories, we interpret the overall findings as suggesting that (a) speech movement planning modulates auditory processing in a manner that may optimize its tuning characteristics for monitoring feedback during speech production and, (b) in conditions with typical auditory feedback, adults who stutter do not appropriately modulate the auditory system prior to speech onset. Lack of modulation of speakers who stutter may lead to maladaptive feedback-driven movement corrections that manifest themselves as repetitive movements or postural fixations.
Functional Parcellation of the Speech Production Cortex
Authors: Tourville Jason A. , Nieto-Castañón Alfonso , Heyne Matthias , Guenther Frank H.
Published: August 2019

Neuroimaging has revealed a core network of cortical regions that contribute to speech production, but the functional organization of this network remains poorly understood.

Purpose

We describe efforts to identify reliable boundaries around functionally homogenous regions within the cortical speech motor control network in order to improve the sensitivity of functional magnetic resonance imaging (fMRI) analyses of speech production and thus improve our understanding of the functional organization of speech production in the brain.

Method

We used a bottom-up, data-driven approach by pooling data from 12 previously conducted fMRI studies of speech production involving the production of monosyllabic and bisyllabic words and pseudowords that ranged from single vowels and consonant–vowel pairs to short sentences (163 scanning sessions, 136 unique participants, 39 different speech conditions). After preprocessing all data through the same pipeline and registering individual contrast maps to a common surface space, hierarchical clustering was applied to contrast maps randomly sampled from the pooled data set in order to identify consistent functional boundaries across subjects and tasks. Boundary completion was achieved by applying adaptive smoothing and watershed segmentation to the thresholded population-level boundary map. Hierarchical clustering was applied to the mean within–functional region of interest (fROI) response to identify networks of fROIs that respond similarly during speech.

Results

We identified highly reliable functional boundaries across the cortical areas involved in speech production. Boundary completion resulted in 117 fROIs in the left hemisphere and 109 in the right hemisphere. Clustering of the mean within-fROI response revealed a core sensorimotor network flanked by a speech motor planning network. The majority of the left inferior frontal gyrus clustered with the visual word form area and brain regions (e.g., anterior insula, dorsal anterior cingulate) associated with detecting salient sensory inputs and choosing the appropriate action.

Conclusion

The fROIs provide insight into the organization of the speech production network and a valuable tool for studying speech production in the brain by improving within-group and between-groups comparisons of speech-related brain activity.

Supplemental Material

https://doi.org/10.23641/asha.9402674
Fretting corrosion of screws contribute to the fixation failure of the femoral neck: a case report
Authors: Luo Jiajun , Ajami Sara , Yu Hai‐Ming , Ma Shuanhong , Chen Shen‐Mao , Zhou Feng , Wang Pei‐Wen , Yao Xue‐Dong , Liu Chaozong
Published: August 2019

Fretting corrosion of metal implants has been associated with implant failure and revision surgeries. This report describes the fixation failure of a femoral neck fracture in a 61‐year‐old male patient due to corrosion of three cannulated screws. Radiographic evaluation at the time of primary surgery demonstrated well‐positioning of the cannulated screws. The patient had no significant medical comorbidities at the time of surgery. However, screw loosening and avascular necrosis were diagnosed after 5 years. At the revision surgery, inflammatory serological markers, C‐reactive protein and erythrocyte sedimentation rate showed no signs of infections, and screws were retrieved. Scanning electron microscopy observations showed that all screws were subjected to fretting corrosion which led to discolouration, pitting attack, and cracking. Thus, Fretting corrosion may have contributed to the failure of the fixation of screws.
Adaptive droop control for balancing SOC of distributed batteries in DC microgrids
Authors: Belal Eman K. , Yehia Doaa M. , Azmy Ahmed M.
Published: August 2019

To guarantee efficient and stable operation of a microgrid, overcharging and unbalanced state of charge (SOC) of batteries have to be mitigated. An adaptive droop control scheme is proposed in this study to provide energy management between distributed batteries having unbalanced SOC and different capacities. The proposed approach suggests using a droop factor proportional to the n th order of SOC in the charging mode and inversely proportional to the n th order of SOC in the discharging mode. Moreover, a modification is proposed to adapt the performance taking into account the battery relative capacity. The relative capacity of an individual battery is defined as the ratio between the maximum capacity of all batteries and the battery capacity. The proposed adaptive droop control scheme is investigated and analysed based on an accurate model of dc microgrid incorporating lithium‐ion battery, photovoltaic, permanent‐magnet synchronous generator‐based wind energy system and constant power loads. Several operating conditions were considered to validate the proposed control approach. The proposed control scheme has been succeeded in keeping the dc bus voltage within limits and equalising SOC of batteries, either having similar or having different capacities.
Analysis and design of the DCM operation boost PFC converter with magnetic control
Authors: Wei Yuqi , Luo Quanming , Wang Jie , Pengju Sun
Published: August 2019

In this study, a novel control scheme for the discontinuous conduction mode (DCM) operation boost power factor correction (PFC) converter is proposed. Instead of adopting constant duty cycle (CDC) control, variable duty cycle control or frequency control, the magnetic control or variable inductor control is adopted to regulate the output voltage, so CDC and switching frequency can be implemented for the switch. The operation principles of the proposed control scheme are discussed in details, and the analysis of the input current, power factor, boundary condition and design considerations are presented. In addition, the modelling of the variable inductor and the DCM operation boost PFC converter with variable inductor are derived in detail, by linearising the non‐linear components, the model of the DCM operation boost PFC converter with the proposed control scheme can be obtained, and the design procedures of the PI controller are presented. Finally, a 70 W experimental prototype is built to verify the theoretical analysis and the effectiveness of the proposed control scheme.
Detection performance analysis of hybrid MIMO radar
Authors: Zhang Qilei , Wu Manqing , Yu Wenxian
Published: August 2019

This study focuses on the detection performance analysis of a notional hybrid MIMO radar, which can be seen as a combination of the phased‐array and distributed MIMO radars. The signal model of the proposed hybrid MIMO radar is re‐derived using the Rayleigh target model. In the sense of Neyman–Person principle, the optimal detector is developed. Then, the detection performance bound is derived based on the relative entropy. Theoretical derivation and numerical examples show that, for most common signal‐to‐noise ratio (SNR) cases, the detection performance of the hybrid MIMO is better than the conventional phased‐array and MIMO radars. Furthermore, for the high SNR case, the proposed system configuration with larger number of sub‐arrays performs better detections, while in the low SNR case, that with smaller number of sub‐arrays performs better detections.
Recognition method of dense false targets jamming based on time‐frequency atomic decomposition
Authors: Hao Zhimei , Yu Wen , Chen Wei
Published: August 2019

Dense false target jamming can affect radar detection performance severely. A method of dense false targets jamming recognition based on time‐frequency atomic decomposition theory and support vector machine (SVM) is proposed to solve the difficulty of dense false targets jamming identification. According to the feature of ambiguity function of dense false targets jamming signal, a Gabor sub‐dictionary which has adaptive variation with signal is designed. The signal is expanded into the corresponding Gabor time‐frequency dictionary by sparse decomposition. After Gabor atomic time‐frequency parameters are extracted as individual feature vectors, SVM is utilised for classification and recognition. The experimental results show that the extracted Gabor atomic time‐frequency parameters can effectively represent the essential features of target and dense false targets jamming, respectively, and this method has a high recognition rate.
On TDE techniques for the radar signal
Authors: Xin Hongcai , Bai Xia , Zhao Juan , Li Bingzhao
Published: August 2019

The time‐delay estimation (TDE) arises in many applications, especially in radar signal processing. In this study, different TDE techniques are considered based on well‐known approaches such as classical matched filter, multiple signal classification, standard least squares (LS), regularisation LS, and compressive sensing for the radar signal. In order to understand the particular behaviour of each technique, comparisons by theoretical analysis and numerical simulations are made. Then some brief conclusions can be obtained from simulation results. Finally, associated with primary factors, future research is prospected on the TDE problem.
Application of spheroidal sequences to sidelobe control in beampattern synthesis
Authors: Fengfeng Chen , Ye Dong , Jiaolong Shan
Published: August 2019

In radar and sonar system, with regard to achieve high interference rejection and enhance target signal detection performance, adaptive beampattern synthesis with low sidelobe levels is desired. A new approach to beampattern synthesis with sidelobe control is developed. The essence of the presented method is to consider the application of spheroidal sequences to beampattern synthesis to alleviate the computational complexity. The presented technique represents a modification of the beampattern synthesis with sidelobe control of the prescribed threshold. The spheroidal sequences approach that characterises the out‐of‐sector angular regions is considered to alleviate the computational cost. The resulting beampattern synthesis approach is showed to be convex, and its second‐order cone formulation is given that facilitates a computationally efficient way to implement the proposed beamformer with the help of the optimal software. Simulation results are given to demonstrate the effectiveness of the presented algorithm and to show the superiority to the state‐of‐the‐art algorithm.
Digital array radar channel error analysis
Authors: Gong Bowen , Yao Zhicheng , Yang Jian , Lu Jian , Wu Zhihui , Geng Zhi
Published: August 2019

The amplitude‐phase error caused by the channel inconsistency in the actual digital array radar and the mutual coupling error caused by the mutual coupling effect have a great influence on the performance of the array. This study analyses and models the error characteristics of amplitude‐phase error and mutual‐coupling error, respectively. Based on the narrow‐band and wide‐band array received signal models, the spatial signal arrival angle estimation accuracy and the beam‐synthesising pattern are used as indicators to analyse the influence of errors on the array. Channel inconsistency and mutual coupling will cause the estimated signal arrival angle to deviate from the true signal direction and the spatial spectrum curve peak will become gentle. In addition, the beam pattern's sidelobe will raise, null orientation will deviate from the interference signal direction, and gain will raise.
Applying of Luneburg lens for multi‐beam TEM‐horn antenna
Authors: Bobreshov Anatoly M. , Uskov Grigory K. , Lysenko Nikolay A. , Sbitnev Nikita S. , Potapov Alexander A.
Published: August 2019

Here, a multi‐beam TEM‐horn antenna with beam direction is proposed. Presented construction allows obtaining scanning beam and complicated antenna patterns, thus it can be used as substitute of ultra‐wideband phased array antennas.
Spatial‐temporal correlated sea clutter simulation based on the probability definition with extended samples for airborne radar
Authors: Huihuang Mao , Wenchong Xie , Xinggang Zhao , Saiqiang Xia
Published: August 2019

Sea clutter is often examined to be of spatial‐temporal correlation which highly affects the detection performance on ship targets for airborne early warning radar. Therefore, the performance of spatial‐temporal correlation sea clutter suppression is of significance for assessing ability of radar and radar system design. This study proposes a new method to simulate spatial‐temporal correlated sea clutter with specific distribution form. The new method is presented based on the probability definition with extended samples, and its core operation is the mapping without distorting the distribution form to obtain 2‐D correlated sea clutter. Therefore, it is more effective with comparison of conventional zero memory non‐linear transform and spherically invariant process. The effectivity of proposed method is verified by means of measured data and simulation data simultaneously.
Study of wind direction factor based on sea clutter in littoral environments
Authors: Xin Li , Peng Zhao , Penglang Shui , Xiaoyun Xia , Shuwen Xu
Published: August 2019

Wind direction factor, as a part of some empirical sea clutter models of the normalised radar cross‐section (NRCS), is closely related to wind direction angle, grazing angle and radar wavelength. The use of the low‐grazing‐angle (LGA) sea clutter measured by UHF‐band radar on the Lingshan island to discuss the characteristic of the wind direction factor is investigated. The results indicate that the upwind‐to‐crosswind ratio of NRCS, which is calculated by the empirical model, could not provide a good fit for grazing angles <10°. It was found that the ratio obtained from measured data varies with the sea state (SS) at the same grazing angle, conversely the empirical models was constant. Based on deep analysis of the results, we finally find out the influence of SS could not be ignored. In addition, some suggestions to improve sea clutter model of littoral environments were proposed for practical applications.