bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemically synthesized chevron-like graphene nanoribbons for electrochemical sensors development: determination of epinephrine
Authors: Sainz Raquel , del Pozo María , Vilas-Varela Manuel , Castro-Esteban Jesús , Pérez Corral María , Vázquez Luis , Blanco Elías , Peña Diego , Martín-Gago José A. , Ellis Gary J. , Petit-Domínguez María Dolores , Quintana Carmen , Casero Elena 
Published: September 2020

AbstractWe employ chevron-like graphene nanoribbons (GNRs) synthesized by a solution-based chemical route to develop a novel electrochemical sensor for determination of the neurotransmitter epinephrine (EPI). The sensor surface, a glassy carbon electrode modified with GNRs, is characterized by atomic force microscopy, scanning electron microscopy and Raman spectroscopy, which show that the electrode surface modification comprises of bi-dimensional multilayer-stacked GNRs that retain their molecular structure. The charge transfer process occurring at the electrode interface is evaluated by electrochemical impedance spectroscopy. The sensor is applied to the determination of EPI, employing as an analytical signal the reduction peak corresponding to the epinephrinechrome–leucoepinephrinechrome transition (E = − 0.25 V) instead of the oxidation peak usually employed in the literature (E =  + 0.6 V) in order to minimize interferences. The results obtained demonstrate that chevron-like nanoribbons synthesized by solution methods exhibit reliable electrocatalytic activity for EPI determination. Using differential pulse voltammetry, we obtain a linear concentration range from 6.4 × 10–6to 1.0 × 10–4 M and a detection limit of 2.1 × 10–6 M. The applicability of the sensor was evaluated by determining EPI in pharmaceutical samples with satisfactory results.
Efficacy and safety of posaconazole for the prevention of invasive fungal infections in immunocompromised patients: a systematic review with meta-analysis and trial sequential analysis
Authors: Wong Tse Yee , Loo Yee Shen , Veettil Sajesh Kalkandi , Wong Pei Se , Divya Gopinath , Ching Siew Mooi , Menon Rohit Kunnath 
Published: September 2020

AbstractInvasive fungal infections are a potentially life-threatening complication in immunocompromised patients. The aim of this study was to assess the efficacy and safety of posaconazole as compared with other antifungal agents for preventing invasive fungal infections in immunocompromised patients. Embase, CENTRAL, and MEDLINE were searched for randomized conweekmonthtrolled trials (RCTs) up to June 2020. A systematic review with meta-analysis of RCTs was performed using random-effects model. Trial sequential analysis (TSA) was conducted for the primary outcome to assess random errors. A total of five RCTs with 1,617 participants were included. Posaconazole prophylaxis was associated with a significantly lower risk of IFIs (RR, 0.43 [95% CI 0.28 to 0.66, p = 0.0001]) as compared to other antifungal agents. No heterogeneity was identified between studies (I2 = 0%). No significant associations were observed for the secondary outcomes measured, including risk reduction of invasive aspergillosis and candidiasis, clinical failure, all-cause mortality, and treatment-related adverse events, except for infection-related mortality (RR, 0.31 [95% CI 0.15 to 0.64, p = 0.0001]). Subgroup analysis favoured posaconazole over fluconazole for the prevention of IFIs (RR, 0.44 [95% CI 0.28 to 0.70, p = 0.0004]). TSA confirmed the prophylactic benefit of posaconazole against IFIs. Posaconazole is effective in preventing IFIs among immunocompromised patients, particularly those with hematologic malignancies and recipients of allogenic hematopoietic stem cell transplantation.
Impact of sentinel lymph-node biopsy and FDG-PET in staging and radiation treatment of anal cancer patients
Authors: Slim Najla , Passoni Paolo , Incerti Elena , Tummineri Roberta , Gumina Calogero , Cattaneo Giovanni Mauro , De Nardi Paola , Canevari Carla , Fiorino Claudio , Ronzoni Monica , Tamburini Andrea Marco , Burgio Valentina , Gianolli Luigi , Di Muzio Nadia 
Published: September 2020

AbstractTo assess the role of sentinel lymph-node biopsy (SLNB) and FDG-PET in staging and radiation treatment (RT) of anal cancer patients. This retrospective study was performed on 80 patients (male: 32, female: 48) with a median age of 60 years (39–89 years) with anal squamous cell carcinoma who were treated from March 2008 to March 2018 at the IRCCS San Raffaele Hospital. Patients without clinical evidence of inguinal LNs metastases and/or with discordance between clinical evidence and imaging features were considered for SLNB. FDG-PET was performed in 69/80 patients. Patients with negative imaging in inguinal region and negative SLNB could avoid RT on groin to spare inguinal toxicity. CTV included GTV (primary tumour and positive LNs) and pelvic ± inguinal LNs. PTV1 and PTV2 corresponded to GTV and CTV, respectively, adding 0.5 cm. RT dose was 50.4 Gy/28 fractions to PTV2 and 64.8 Gy/36 fractions to PTV1, delivered with 3DCRT (n = 24) or IMRT (n = 56), concomitant to Mitomycin-C and 5-FU chemotherapy. FDG-PET showed inguinal uptake in 21/69 patients (30%) and was negative in 48/69 patients (70%). Lymphoscintigraphy was performed in 11/21 positive patients (4 patients SLNB confirmed inguinal metastases, 6 patients false positive and 1 patient SLN not found), and in 29/48 negative patients (5/29 showed metastases, 23/29 true negative and 1 SLN not found). Sensitivity, specificity, positive and negative predictive value of FDG-PET were 62%, 79%, 40% and 82%, respectively. Median follow-up time from diagnosis was 40.3 months (range: 4.6–136.4 months): 69 patients (86%) showed a complete response, 10 patients (13%) a partial response, 1 patient (1%) a stable disease. Patients treated on groin (n = 54) versus not treated (n = 26) showed more inguinal dermatitis (G1–G2: 50% vs. 12%; G3–G4: 17% vs. 0%, p < 0.05). For patients treated on groin, G3–G4 inguinal dermatitis, stomatitis and neutropenia were significantly reduced with IMRT against 3DCRT techniques (13% vs. 36%, p = 0.10; 3% vs. 36%, p = 0.003; 8% vs. 29%, p = 0.02, respectively). SLNB improves the FDG-PET inguinal LNs staging in guiding the decision to treat inguinal nodes. IMRT technique significantly reduced G3-G4 toxicities when patients are treated on groin.
In vivo T1 mapping for quantifying glymphatic system transport and cervical lymph node drainage
Authors: Xue Yuechuan , Liu Xiaodan , Koundal Sunil , Constantinou Stefan , Dai Feng , Santambrogio Laura , Lee Hedok , Benveniste Helene 
Published: September 2020

AbstractDynamic contrast-enhanced magnetic resonance imaging (MRI) for tracking glymphatic system transport with paramagnetic contrast such as gadoteric acid (Gd-DOTA) administration into cerebrospinal fluid (CSF) requires pre-contrast data for proper quantification. Here we introduce an alternative approach for glymphatic system quantification in the mouse brain via T1 mapping which also captures drainage of Gd-DOTA to the cervical lymph nodes. The Gd-DOTA injection into CSF was performed on the bench after which the mice underwent T1 mapping using a 3D spoiled gradient echo sequence on a 9.4 T MRI. In Ketamine/Xylazine (KX) anesthetized mice, glymphatic transport and drainage of Gd-DOTA to submandibular and deep cervical lymph nodes was demonstrated as 25–50% T1 reductions in comparison to control mice receiving CSF saline. To further validate the T1 mapping approach we also verified increased glymphatic transport of Gd-DOTA transport in mice anesthetized with KX in comparison with ISO. The novel T1 mapping method allows for quantification of glymphatic transport as well as drainage to the deep and superficial cervical lymph nodes. The ability to measure glymphatic transport and cervical lymph node drainage in the same animal longitudinally is advantageous and time efficient and the coupling between the two systems can be studied and translated to human studies.
Metabolic response of the Siberian wood frog Rana amurensis to extreme hypoxia
Authors: Shekhovtsov Sergei V. , Bulakhova Nina A. , Tsentalovich Yuri P. , Zelentsova Ekaterina A. , Yanshole Lyudmila V. , Meshcheryakova Ekaterina N. , Berman Daniil I. 
Published: September 2020

AbstractThe Siberian wood frogRana amurensisis a recently discovered example of extreme hypoxia tolerance that is able to survive several months without oxygen. We studied metabolomic profiles of heart and liver ofR. amurensisexposed to 17 days of extreme hypoxia. Without oxygen, the studied tissues experience considerable stress with a drastic decrease of ATP, phosphocreatine, and NAD+ concentrations, and concomitant increase of AMP, creatine, and NADH. Heart and liver switch to different pathways of glycolysis with differential accumulation of lactate, alanine, succinate, as well as 2,3-butanediol (previously not reported for vertebrates as an end product of glycolysis) and depletion of aspartate. We also observed statistically significant changes in concentrations of certain osmolytes and choline-related compounds. Low succinate/fumarate ratio and high glutathione levels indicate adaptations to reoxygenation stress. Our data suggest that maintenance of the ATP/ADP pool is not required for survival ofR. amurensis, in contrast to anoxia-tolerant turtles.
Topologization of β-antimonene on Bi2Se3 via proximity effects
Authors: Holtgrewe K. , Mahatha S. K. , Sheverdyaeva P. M. , Moras P. , Flammini R. , Colonna S. , Ronci F. , Papagno M. , Barla A. , Petaccia L. , Aliev Z. S. , Babanly M. B. , Chulkov E. V. , Sanna S. , Hogan C. , Carbone C. 
Published: September 2020

AbstractTopological surface states usually emerge at the boundary between a topological and a conventional insulator. Their precise physical character and spatial localization depend on the complex interplay between the chemical, structural and electronic properties of the two insulators in contact. Using a lattice-matched heterointerface of single and double bilayers of β-antimonene and bismuth selenide, we perform a comprehensive experimental and theoretical study of the chiral surface states by means of microscopy and spectroscopic measurements complemented by first-principles calculations. We demonstrate that, although β-antimonene is a trivial insulator in its free-standing form, it inherits the unique symmetry-protected spin texture from the substrate via a proximity effect that induces outward migration of the topological state. This “topologization” of β-antimonene is found to be driven by the hybridization of the bands from either side of the interface.
Eucalyptus derived heteroatom-doped hierarchical porous carbons as electrode materials in supercapacitors
Authors: Wen Yanliang , Chi Liang , Wenelska Karolina , Wen Xin , Chen Xuecheng , Mijowska Ewa 
Published: September 2020

AbstractCarbon-based supercapacitors have aroused ever-increasing attention in the energy storage field due to high conductivity, chemical stability, and large surface area of the investigated carbon active materials. Herein, eucalyptus-derived nitrogen/oxygen doped hierarchical porous carbons (NHPCs) are prepared by the synergistic action of the ZnCl2 activation and the NH4Cl blowing. They feature superiorities such as high specific surface area, rational porosity, and sufficient N/O doping. These excellent physicochemical characteristics endow them excellent electrochemical performances in supercapacitors: 359 F g−1 at 0.5 A g−1 in a three-electrode system and 234 F g−1 at 0.5 A g−1 in a two-electrode system, and a high energy density of 48 Wh kg−1 at a power density of 750 W kg−1 accompanied by high durability of 92% capacitance retention through 10,000 cycles test at a high current density of 10 A g−1 in an organic electrolyte. This low-cost and facile strategy provides a novel route to transform biomass into high value-added electrode materials in energy storage fields.
Emotionality modulates the impact of chronic stress on memory and neurogenesis in birds
Authors: Lormant Flore , Ferreira Vitor Hugo Bessa , Meurisse Maryse , Lemarchand Julie , Constantin Paul , Morisse Mélody , Cornilleau Fabien , Parias Céline , Chaillou Elodie , Bertin Aline , Lansade Léa , Leterrier Christine , Lévy Frédéric , Calandreau Ludovic 
Published: September 2020

AbstractChronic stress is a strong modulator of cognitive processes, such as learning and memory. There is, however, great within-individual variation in how an animal perceives and reacts to stressors. These differences in coping with stress modulate the development of stress-induced memory alterations. The present study investigated whether and how chronic stress and individual emotionality interrelate and influence memory performances and brain neurogenesis in birds. For that, we used two lines of Japanese quail (Coturnix japonica) with divergent emotionality levels. Highly (E+) and less (E−) emotional quail were submitted to chronic unpredictable stress (CUS) for 3 weeks and trained in a spatial task and a discrimination task, a form of cue-based memory. E + and E− birds were also used to assess the impact of CUS and emotionality on neurogenesis within the hippocampus and the striatum. CUS negatively impacted spatial memory, and cell proliferation, and survival in the hippocampus. High emotionality was associated with a decreased hippocampal neurogenesis. CUS improved discrimination performances and favored the differentiation of newborn cells into mature neurons in the striatum, specifically in E+ birds. Our results provide evidence that CUS consequences on memory and neural plasticity depends both on the memory system and individual differences in behavior.
Ultrafast spatiotemporal photocarrier dynamics near GaN surfaces studied by terahertz emission spectroscopy
Authors: Yamahara Kota , Mannan Abdul , Kawayama Iwao , Nakanishi Hidetoshi , Tonouchi Masayoshi 
Published: September 2020

AbstractGallium nitride (GaN) is a promising wide-bandgap semiconductor, and new characterization tools are needed to study its local crystallinity, carrier dynamics, and doping effects. Terahertz (THz) emission spectroscopy (TES) is an emerging experimental technique that can probe the ultrafast carrier dynamics in optically excited semiconductors. In this work, the carrier dynamics and THz emission mechanisms of GaN were examined in unintentionally doped n-type, Si-doped n-type, and Mg-doped p-type GaN films. The photocarriers excited near the surface travel from the excited-area in an ultrafast manner and generate THz radiation in accordance with the time derivative of the surge drift current. The polarity of the THz amplitude can be used to determine the majority carrier type in GaN films through a non-contact and non-destructive method. Unique THz emission excited by photon energies less than the bandgap was also observed in the p-type GaN film.
MicroRNA-197 regulates chondrocyte proliferation, migration, and inflammation in pathogenesis of osteoarthritis by targeting EIF4G2
Authors: Gao Shijie , Liu Liang , Zhu Shibo , Wang Dawei , Wu Qiang , Ning Guangzhi , Feng Shiqing 
Published: September 2020

AbstractRecent studies have demonstrated that microRNAs (miRNAs) are involved in many pathological conditions including osteoarthritis (OA). In the present study, we aimed to investigate the role of miR-197 in OA and the potential molecular mechanism. The expression levels of miR-197 were detected by quantitative real-time PCR analysis. Cell proliferation and migration abilities were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide and transwell assays. The concentrations of inflammatory cytokines, including IL-1β, IL-6, and TNF-α, were detect using ELISA assay. Furthermore, luciferase reporter and rescue assays were applied to identify the functional target gene of miR-197 in OA. The results showed that miR-197 expression was significantly down-regulated in the OA cartilage tissues compared with normal cartilage tissues, accompanied by up-regulation of EIF4G2 expression. An inverse correlation was found between EIF4G2 and miR-197 expressions in OA cartilage tissues. Treatment with miR-197 mimics promoted the growth and migration abilities of chondrocytes, while miR-197 inhibitors induced the opposite effects. Furthermore, restoration of miR-197 significantly decreased IL-1β, IL-6, and TNF-α expression, whereas knockdown of miR-197 led to a induction in these inflammatory mediators. Moreover, EIF4G2 was predicted and confirmed as a directly target of miR-197. Overexpressed miR-197 could down-regulate EIF4G2 expression in chondrocytes, while miR-197 knockdown could elevate EIF4G2 expression. Additionally, EIF4G2 overexpression reversed the effects of miR-197 mimics on chondrocytes proliferation, migration, and inflammation. Taken together, our study demonstrated that miR-197 promotes chondrocyte proliferation, increases migration, and inhibits inflammation in the pathogenesis of OA by targeting EIF4G2, indicating the potential therapeutic targets of the miR-197/EIF4G2 axis for OA treatment.
Promiscuous DNA cleavage by HpyAII endonuclease is modulated by the HNH catalytic residues
Authors: Kumar Sumith , Bangru Sushant , Kumar Ritesh , Rao Desirazu N. 
Published: September 2020

Abstract
Helicobacter pylori is a carcinogenic bacterium that is responsible for 5.5% of all human gastric cancers. H. pylori codes for an unusually large number of restriction–modification (R–M) systems and several of them are strain-specific and phase-variable. HpyAII is a novel Type IIs phase-variable restriction endonuclease present in 26695 strain of H. pylori. We show that HpyAII prefers two-site substrates over one-site substrates for maximal cleavage activity. HpyAII is less stringent in metal ion requirement and shows higher cleavage activity with Ni2+ over Mg2+. Mutational analysis of the putative residues of the HNH motif of HpyAII confirms that the protein has an active HNH site for the cleavage of DNA. However, mutation of the first Histidine residue of the HNH motif to Alanine does not abolish the enzymatic activity, but instead causes loss of fidelity compared with wildtype HpyAII. Previous studies have shown that mutation of the first Histidine residue of the HNH motif of all other known HNH motif motif-containing enzymes completely abolishes enzymatic activity. We found, in the case of HpyAII, mutation of an active site residue leads to the loss of endonuclease fidelity. The present study provides further insights into the evolution of restriction enzymes.
Vascularized Bone Grafting for Scaphoid Nonunion with Humpback Deformity: The Surgical Technique
Authors: Kawasaki Keikichi , Nemoto Tetsuya , Kubo Kazutoshi , Tomita Kazunari , Inagaki Katsunori 
Published: September 2020

AbstractBackground Scaphoid nonunion with humpback deformity and avascular necrosis (AVN) is a challenging problem. Correction of dorsal intercalated segment instability (DISI) requires grafting of a large and hard vascularized bone segment onto the volar side of the scaphoid.Purposes We have been treating the patients with one-incision vascularized bone grafting technique for scaphoid nonunion to improve blood supply and correct humpback deformity. We evaluated these cases retrospectively to the surgical efficacy of our procedure.Methods We harvested vascularized bone from the dorsal side of the radius using the method by Zaidemberg et al and inserted the cortical aspect into the scaphoid volar side using a direct lateral approach. Totally, 11 patients (nine males andtwo females) with a mean age of 40 years were recruited for this study. The mean time from fracture to treatment was 6 years and 3 months. The mean preoperative radiolunate angle was 25 degrees. All the patients showed AVN of the proximal scaphoid on T1-weighted images. An averaged follow-up period was 2 years and 3 months.Results Postoperative computed tomography revealed bony union in 10 patients (91% of union rate) with a mean modified Mayo'swrist score of 88 points (range, 75–100 points) and a mean disabilities of arm, shoulder, and hand (DASH) score of 4 points (range, 0–20 points). The mean radiolunate angle was corrected from 25 to 5 degrees. No adverse events were observed, except temporary mild paresthesia of the radial nerve territory in two patients.Conclusion This technique effectively corrected DISI in patients with scaphoid nonunion accompanied by humpback deformity and AVN.
Determination of Accurate Position of Umbilical Venous Catheters in Premature Infants
Authors: Akar Selahattin , Dincer Emre , Topcuoğlu Sevilay , Yavuz Taner , Akay Hatice , Gokmen Tulin , Karatekin Guner 
Published: September 2020

Objective The aim of the study is to determine the most accurate length and position of umbilical venous catheter (UVC).
Study Design This prospective study included premature infants who were admitted to the neonatal intensive care unit with inserted UVC between January 1, 2014 and December 31, 2015. The length of UVC was calculated according to the Shukla formula [(3 × birth weight + 9)/2 + 1] and the catheter was inserted under sterile conditions. After the insertion, umbilical catheter was first evaluated through chest X-ray and then with echocardiography to confirm its position. Catheters seen on the chest X-ray at the level of T9-T10 vertebrae were classified as “accurate position,” those seen above T9 vertebra as “high position,” and the catheters identified below T10 vertebra were classified as “low position.”
Results A total of 68 infants smaller than 36 weeks of gestation were included in the study. In echocardiographic evaluation, 80% of the cases identified as in the “accurate position,” 100% of the cases classified as in a “high position,” and 33% of the cases defined as in a “low position” on the chest X-rays were found to be intracardiac. In our study, length of the catheter calculated according to the Shukla formula was intracardiac in 88.2% of premature infants.
Conclusion Radiography alone is not sufficient for the determination of adequate position of umbilical catheter, especially in premature infants. Specialists practicing in neonatal intensive care units could improve themselves and evaluate UVC with echocardiography, making this a routine part of clinical practice. Echocardiography-guided fixation of the catheter will reduce the complications related to catheter malposition.
Key Points
Teaching About Magnetism
Authors: Reiland Robert J. 
Published: September 2020

This book is a comprehensive workshop manual on teaching magnetism, listing 12 laboratory activities on a wide range of magnetism topics. It also covers demonstrations and displays, and computer applications for teaching magnetism. Sections on homework assignments, the use of technology for teaching magnetism, and physics contest events are included.
The workshop manual has been tested and improved over time following feedback from participants.
Key highlights:An invaluable resource on how to use demonstrations to inspire studentsThe workshop was initially tested in the 1993 class of PTRA-PLUS (Physics Teaching Resource Agent), a program designed to train superior physics teachers across the U.S. in giving workshops for under-prepared physics and physical science teachers.Sources of inspiration contributing to the manual include the journal of the American Association of Physics Teachers (AAPT), The Physics Teacher.
Teaching About Magnetism is an excellent resource for physics teachers. It is also of interest to anyone who works with magnetic devices, magnetic equipment, magnetic flux, magnetization dynamics, magnetochemistry, or nanomagnetism.