bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of the Rate of Atom Transfer Radical Polymerization in Organic Solvents by Addition of Water: An Electrochemical Study.
Authors: Pavan Paola , Lorandi Francesca , De Bon Francesco , Gennaro Armando , Isse Abdirisak A. 
Published: June 2021

AbstractAddition of water to organic solvents enhances the rate of atom transfer radical polymerization (ATRP). To understand the origin of this rate enhancement, the effects of H2O on the redox properties of [CuIITPMA]2+ and [BrCuIITPMA]+ (TPMA=tris(2‐pyridylmethyl)amine), and on the ATRP equilibrium (KATRP) and activation rate (kact) constants of methyl 2‐bromopropionate by [CuITPMA]+ were investigated in CH3CN, DMF and DMSO and their mixtures with methyl acrylate (MA). E°s of the complexes allowed evaluation of the relative halidophilicities of [CuIITPMA]2+ and [CuITPMA]+, KIIBr and KIBr, respectively. KIIBr/KIBr dropped in pure solvents and solvent/MA mixtures when 11 % (v/v) H2O was added, suggesting that H2O hampers the stability of the deactivator [BrCuIITPMA]+. Conversely, both kact and KATRP were enhanced by the presence of water. In solvent/MA mixtures (50/50, v/v), addition of 11 % (v/v) H2O increased KATRP by a factor of 2–3, which could explain the accelerating effect of H2O on ATRP in organic solvents.
Interplay between Conductivity, Matrix Relaxations and Composition of Ca‐Polyoxyethylene Polymer Electrolytes
Authors: Pagot Gioele , Vezzù Keti , Martinez‐Cisneros Cynthia Susana , Antonelli Claire , Levenfeld Belen , Varez Alejandro , Sanchez Jean‐Yves , Di Noto Vito 
Published: June 2021

AbstractIn this report, the conductivity mechanism of Ca2+‐ion in polyoxyethylene (POE) solid polymer electrolytes (SPEs) for calcium secondary batteries is investigated by broadband electrical spectroscopy studies. SPEs are obtained by dissolving into the POE hosting matrix three different calcium salts: CaTf2, Ca(TFSI)2 and CaI2. The investigation of the electric response of the synthetized SPEs reveals the presence in materials of two polarization phenomena and two dielectric relaxation events. It is demonstrated that the nature of the anion (i. e., steric hindrance, charge density and ability to act as coordination ligand) and the density of “dynamic crosslinks” of SPEs is fundamental in the establishment of ion‐ion/ion‐polymer interactions. The long‐range charge migration processes occurring along the two revealed percolation pathways of the electrolytes are generally coupled with the polymer host dynamics and depend on the temperature and the anion nature. This study offers the needed tools for understanding Ca2+ conduction in POE‐based electrolytes.
Size‐Selective Photoelectrochemical Reactions in Microporous Environments: Clark Probe Investigation of Pt@g‐C3N4 Embedded into Intrinsically Microporous Polymer (PIM‐1)
Authors: Zhao Yuanzhu , Malpass‐Evans Richard , Carta Mariolino , McKeown Neil B. , Fletcher Philip J. , Kociok‐Köhn Gabriele , Lednitzky Diana , Marken Frank 
Published: June 2021

AbstractGraphitic carbon nitride (g‐C3N4) with photo‐attached platinum (Pt@g‐C3N4) is known to generate hydrogen under illumination in aqueous environments in the presence of carbohydrate hole quenchers. Here, Pt@g‐C3N4 is embedded into a polymer of intrinsic microporosity (PIM‐1) host material with a molecularly rigid structure to maintain active unblocked catalyst surfaces and to control transport to/from the photocatalyst. A Clark‐type oxygen/hydrogen sensor is employed with Pt@g‐C3N4 embedded into PIM‐1 applied as a film to be the gas‐permeable sensor membrane. Oxygen reduction and hydrogen production are observed in situ as a function of light exposure and quencher concentration. Significant size‐selectivity favouring smaller more flexible saccharides or carbohydrate/ hydrocarbon quenchers is observed and attributed to rate limiting PIM‐1 micropore transport. Effective hydrogen production through a Teflon membrane is demonstrated. The underlying hydrogen production/ photocurrent enhancing effects of the microporous PIM‐1 film on the photochemical process are revealed.
Probability distribution based resource management for multitenant cloud clusters
Authors: Zhou Jun , Feng Dan , Wang Fang 
Published: June 2021

AbstractAccurate resource allocation and colocating jobs are effective ways to increase resource utilization and reduce costs in modern datacenters. The main challenges are fluctuations in resource consumption and interference among colocated jobs. Therefore, we propose a resource management schema based on the probability distributions of resource consumption and completion time for multitenant cloud clusters. First, we found that the characteristics of the task can be well described by the probability distribution of resource consumption and completion time, and the probability distribution function can be obtained by Gaussian fitting. Second, we propose a probability distribution based resource allocation (PDRA) strategy for batch jobs. Third, we design a tail latency aware allocation (TLAA) strategy to use transient resources efficiently while ensuring tail latency requirements. Finally, we design a cost‐effective resource revocation (CERR) strategy to revoke transient resources with minimal eviction costs. Experimental results demonstrate the efficiency of our resource management. Our resource allocation strategies (PDRA and TLAA) can effectively improve resource utilization and reduce job completion time. CERR can reduce the impact of resource revocation on batch jobs and perform better than existing resource revocation strategies.
Olefin Metathesis by First‐Row Transition Metals
Authors: Belov Dmitry S. , Tejeda Gabriela , Bukhryakov Konstantin V. 
Published: June 2021

AbstractCatalytic olefin metathesis based on the second‐ and third‐row transition metals has become one of the most powerful transformations in modern organic chemistry. The shift to first‐row metals to produce fine and commodity chemicals would be an important achievement to complement existing methods with inexpensive and greener alternatives. In addition, those systems can offer unusual reactivity based on the unique electronic structure of the base metals. In this Minireview, we summarize the progress of the development of alkylidenes and metallacycles of first‐row transition metals from scandium to nickel capable of performing cycloaddition and cycloreversion steps, crucial reactions in olefin metathesis. In addition, we will discuss systems capable of performing olefin metathesis; however, the nature of active species is not yet known.
Visible‐Light‐Controlled Azobenzene‐Cyclodextrin Host‐Guest Interactions for Biomedical Applications and Surface Functionalization
Authors: Nie Chen , Liu Chengwei , Sun Shaodong , Wu Si 
Published: June 2021

AbstractAzobenzene/cyclodextrin (CD) host‐guest complexes can dissociate and reform under light irradiation because of photoisomerization of azobenzene. Azobenzene/CD host‐guest interactions have been used to construct photo‐controlled supramolecular systems. However, typical azobenzene/CD host‐guest interactions are controlled using UV light that may damage organic and biological components. To broaden the applications of this type of supramolecular construct, visible‐light‐responsive azobenzene/CD host‐guest interactions have received growing attention in recent years. In this Concept, the host‐guest interactions of visible‐light‐responsive azobenzene derivatives with CDs and their applications are reviewed. In particular, the advantages of visible‐light‐responsive azobenzene/CD systems for biomedical applications and surface functionalization are discussed, such as photo‐controlled release, photoswitchable surfaces, and orthogonal supramolecular micropatterned surfaces. Challenges and perspectives for the field are summarized and discussed.
Deep‐Level Transient Spectroscopy for Effective Passivator Selection in Perovskite Solar Cells to Attain High Efficiency over 23%
Authors: Ren Xiaodong , Zhang Bobo , Zhang Lu , Wen Jialun , Che Bo , Bai Dongliang , You Jiaxue , Chen Tao , Liu Shengzhong (Frank) 
Published: June 2021

AbstractMost studies choose passivators essentially in a trial‐and‐error fashion in an attempt to attain high efficiency in perovskite solar cells (PSCs). Using deep‐level transient spectroscopy (DLTS) measurements, the type of defects in perovskite films was determined to guide the passivator selection for PSCs. Three kinds of positively charged defects were found in the target PSC system. Fluorinated phenylethylamine hydroiodide (FPEAI) was chosen to passivate the surface defects due to the electronegativity and hydrophobicity of fluorine. Due to the decreased surface roughness, increased hydrophobicity, lowered defect density, and improved carrier dynamics as observed by ultrafast transient absorption spectroscopy (TAS), a PSC with meta‐F‐PEAI had the best efficiency over 23 % with open‐circuit voltage of 1.155 V and fill factor of 80.15 %. In addition, the long‐term stability of the PSC was significantly improved. The present work provides a new means to select the best passivator for different types of defects.
Impact of age and gender on lymphocyte subset counts in patients with COVID‐19
Authors: Löhr Phillip , Schiele Stefan , Arndt Tim Tobias , Grützner Stefanie , Claus Rainer , Römmele Christoph , Müller Gernot , Schmid Christoph , Dennehy Kevin M. , Rank Andreas 
Published: June 2021

AbstractIn symptomatic patients with acute Coronavirus disease 2019 (COVID‐19), lymphocytopenia is one of the most prominent laboratory findings. However, to date age and gender have not been considered in assessment of COVID‐19‐related cell count alterations. In this study, the impact of COVID‐19 as well as age and gender on a large variety of lymphocyte subsets was analyzed in 33 COVID‐19 patients and compared with cell counts in 50 healthy humans. We confirm that cell counts of total lymphocytes, B, NK, cytotoxic and helper T cells are reduced in patients with severe COVID‐19, and this tendency was observed in patients with moderate COVID‐19. Decreased cell counts were also found in all subsets of these cell types, except for CD4+ and CD8+ effector memory RA+ (EMRA) and terminal effector CD8+ cells. In multivariate analysis however, we show that in addition to COVID‐19, there is an age‐dependent reduction of total, central memory (CM), and early CD8+ cell subsets, as well as naïve, CM, and regulatory CD4+ cell subsets. Remarkably, reduced naïve CD8+ cell counts could be attributed to age alone, and not to COVID‐19. By contrast, decreases in other subsets could be largely attributed to COVID‐19, and only partly to age. In addition to COVID‐19, male gender was a major factor influencing lower counts of CD3+ and CD4+ lymphocyte numbers. Our study confirms that cell counts of lymphocytes and their subsets are reduced in patients with COVID‐19, but that age and gender must be considered when interpreting the altered cell counts.
A critical point in chiral chromatography–mass spectrometry analysis of ketamine metabolites
Authors: Barbarossa Andrea , Bardhi Anisa , Gazzotti Teresa , Pagliuca Giampiero 
Published: June 2021

AbstractKetamine is a widely used dissociative drug, whose quantification in plasma and urine can be of pharmacological, toxicological, and clinical interest. Although tandem mass spectrometry allows the reliable determination of ketamine and its metabolites in biological matrices, the structural similarity between norketamine (main active metabolite) and dehydronorketamine (a less relevant metabolite) can represent a critical aspect. These compounds differ exclusively in two hydrogen atoms, but the consequent two‐unit difference in their mass/charge ratio is partially nullified by the isotopic abundance of the chlorine atom present in their structure. This, along with their similar fragmentation pattern, can result in the incorrect identification of the enantiomers of these ketamine metabolites even with triple quadrupole instruments, if shared transitions are monitored after chiral chromatography. The key to prevent norketamine overestimation is therefore observing analyte‐specific MS/MS transitions. Here, we describe in detail how we investigated this issue, during the development of an analytical method for ketamine and norketamine enantiomer determination in plasma.
Mechanisms of density dependence in juvenile salmonids: prey depletion, interference competition, or energy expenditure?
Authors: Matte Jean‐Michel O. , Fraser Dylan J. , Grant James W. A. 
Published: June 2021

AbstractDensity dependence is a strong regulator of animal populations, operating primarily through intraspecific competition for a limiting resource. Because food is generally limited in natural environments, it is typically assumed that increasing animal density leads to reduced individual fitness through food depletion or monopolization. However, recent work demonstrates that density dependence can occur without apparent food depletion, or with virtually unlimited resources, suggesting that other mechanisms must also be important. Alternatively, density‐dependent regulation could be achieved through increasing energy costs rather than decreasing food abundance. The relative importance of these two processes (food depletion and energy costs) and their underlying mechanisms remains unclear. Here, we manipulated the density of juvenile stream‐dwelling brook trout (Salvelinus fontinalis) in three neighboring populations over two consecutive summers to relate food availability and consumption to density‐dependent growth, survival, and their trade‐off. Despite strong patterns of density dependence and evidence of food limitation, increasing fish density did not lead to detectable prey depletion in the environment. Instead, behavioral observations suggested that increasing densities resulted in higher energetic costs, primarily via increasing interference competition and the use of less suitable foraging microhabitats. These results highlight that animal populations may be regulated by density dependence without necessarily impacting prey communities.
Analytical Modelling of Electron‐coupled Ion Transfers with Immobilized vs Soluble Redox Transducer at Thick Film‐modified Electrodes
Authors: González J. , Laborda E. , Molina A. 
Published: June 2021

AbstractAnalytical theoretical solutions are deduced for the current‐potential response, concentration profiles and interfacial potentials of electron‐coupled ion transfers in the cyclic voltammetry with thick film‐modified electrodes. The theory covers a wide variety of possible situations, namely, the redox transducer can be either immobilized on the working electrode or freely diffusing in the organic film, and the ion transfer can be either simple or complicated by homogeneous chemical processes. A comparative and comprehensive study of each case is performed, establishing the key parameters that define the behaviour of the system, as well as guidelines to analyse its electrochemical signal.
A wide band log periodic millimeter‐wave antenna for 5G femtocells applications
Authors: V Harini , M.V.S Sairam , R Madhu 
Published: June 2021

AbstractA wide band log periodic millimeter‐wave antenna is proposed for 5G femtocells applications. This log periodic antenna consists of circular patches with radius kept up at a proportion of scaling factor . The proposed antenna prototype is designed and simulated at a frequency range of 25 to 35.5 GHz with a fractional bandwidth of 34.73%. This proposed antenna exhibits low return loss at all frequency bands such as 26, 27.5, 29, 30, 32, 33, 35, and 38.1 GHz with reflection coefficient values such as , and dB including almost 101% radiation efficiency and attained maximum gain values such as , and dBi. Over the entire frequency band, the proposed antenna exhibits right‐hand circular polarization with an axial ratio of under 3 dB. Furthermore, the antenna is fabricated and measured the results where there is a better agreement with simulated results. This type of low‐profile antenna can be applicable for femto base stations for 5G communications.
UPLC–PDA‐ESI–QTOF–MS/MS and GC‐MS analysis of Iranian Dracocephalum moldavica L.
Authors: Fattahi Azin , Shakeri Abolfazl , Tayarani‐Najaran Zahra , Kharbach Mourad , Segers Karen , Heyden Yvan Vander , Taghizadeh Seyedeh Faezeh , Rahmani Hanieh , Asili Javad 
Published: June 2021

AbstractDracocephalum moldavica L. is a significant component in the Iranian food basket. This study aimed to investigate the bioactive compounds and biological activities of different extracts obtained from D. moldavica aerial parts. From the aerial parts, a crude methanolic (MeOH) extract and its four sub‐fractions, that is, petroleum ether (Pet), ethyl acetate (EtOAc), n‐butanol (n‐BuOH), and aqueous (water) extracts were obtained. The total phenolic and flavonoid contents as well as the antioxidant and cytotoxic activities of the extracts were determined. Moreover, the phytochemical profiles of the essential oil (EO) and of those extracts with the highest antioxidant activity measured by GC/MS and UPLC–PDA‐ESI–QTOF–MS/MS. Results showed that the highest concentrations of phenols and flavonoids as well as the most potent antioxidant potential according to the DPPH method were determined in the EtOAc and MeOH extracts with IC50 values of 22.0 and 34.4 µg.ml‐1, respectively. Quantitative analysis of these extracts was subsequently performed by UPLC–PDA‐ESI–QTOF–MS/MS. Both extracts contained mainly rosmarinic acid, caffeic acid, and 2‐hydroxycinnamic acid, which may be responsible for their high antioxidant activity. Moreover, none of the extracts showed cytotoxic effects against MCF7, SW48, and a normal cell line of mouse embryonic fibroblast cells (NIH/3T3) in the tested concentrations (up to 400 μg.ml‐1). Additionally, GC‐MS analysis showed that oxygenated monoterpenes (55.4%) were the main constituents of the EO of D. moldavica.
SMARCA2‐NR4A3 is a novel fusion gene of extraskeletal myxoid chondrosarcoma identified by RNA next‐generation sequencing
Authors: Wei Shuanzeng , Pei Jianming , von Mehren Margaret , Abraham John A. , Patchefsky Arthur S. , Cooper Harry S. 
Published: June 2021

AbstractExtraskeletal myxoid chondrosarcoma (EMC) is a rare sarcoma of uncertain differentiation, characterized by recurrent chromosomal translocation involving NR4A3 (9q22.33) in more than 90% of cases. Five fusion partners for NR4A3 have been described including: EWSR1 (22q12.2), TAF15 (17q12), FUS (16p11.2), TCF12 (15q21), and TFG (3q12.2). This report describes a patient with an EMC at the dorsum of the right foot. The tumor showed a cord‐like and reticular pattern in a background of myxoid matrix. The tumor cells demonstrated an epithelioid morphology with prominent nucleoli. The tumor cells were positive for synaptophysin, GFAP, with focal positivity for CD117, S100, Cam5.2, and NSE, and negative for AE1/3, desmin, and SMA. An RNA next‐generation sequencing test showed a SMARCA2‐NR4A3 gene fusion which has not been previously reported. The exon 3 of SMARCA2 was fused to exon 3 of NR4A3. This fusion was confirmed by NR4A3 break‐apart FISH, although both SMARCA2 (9p24.3) and NR4A3 (9q22.33) are located on chromosome 9. The tumor cells showed retained expression of INI1 and SMARCA2 by immunohistochemistry.
Hyperparathyroidism subsequent to radioactive iodine therapy for Graves' disease
Authors: Law Richard H. , Quan Daniel L. , Stefan Andrew J. , Peterson Edward L. , Singer Michael C. 
Published: June 2021

AbstractBackgroundThe development of primary hyperparathyroidism (PHPT) after radioactive iodine (RAI) treatment for thyroid disease is poorly characterized. The current study is the largest reported cohort and assesses the disease characteristics of patients treated for PHPT with a history of RAI exposure.MethodsA retrospective analysis comparing patients, with and without a history of RAI treatment, who underwent surgery for PHPT.ResultsTwenty‐eight of the 469 patients had a history of RAI treatment, all for Graves' disease. Patients with a history of RAI exposure had similar disease characteristics compared to control; however, patients with a history of RAI treatment had a higher rate of recurrence (7.4% vs 1.2%, p = 0.012).ConclusionPHPT in patients with a history of RAI treatment can be approached in the same manner as RAI naive PHPT patients; however, the risk of recurrence of PHPT in RAI exposed patients may be higher.
Predictive value of ipsilateral central lymph node metastasis for contralateral central lymph node metastasis in patients with thyroid cancer: Systematic review and meta‐analysis
Authors: Kim Do Hyun , Kim Geun‐Jeon , Kim Sung Won , Hwang Se Hwan 
Published: June 2021

AbstractCareful consideration of prophylactic central compartment dissection is required to ensure that its benefits outweigh its risks in the thyroid cancer. Sixteen prospective or retrospective studies were included. True positive, true negative, false positive, and false negative were extracted from each study. The diagnostic odds ratio of ipsilateral central lymph node metastasis (iCLNM) for predicting contralateral central lymph node metastasis (cCLNM) was 12.9237 (95% confidence interval [CI], 8.1595–20.4695). The area under the summary receiver operating characteristic curve was 0.854. The sensitivity, specificity, and negative predictive value were 0.8925 [0.8232–0.9368], 0.6884 [0.6311–0.7404], and 0.9802 [0.9631–0.9894], respectively. There were strong correlations between cCLNM and clinicopathologic characteristics. Ipsilateral central lymph node pathology is useful for predicting contralateral central compartment invasion in patients with thyroid cancer. In addition, clinicopathologic characteristics were associated with cCLNM in patients with unilateral thyroid cancer.
Chronic viral hepatitis, HIV infection and Non‐Hodgkin lymphomas in West Africa, a case‐control study
Authors: Jaquet Antoine , Boni Simon P. , Boidy Kouakou , Tine Judicaël , Tchounga Boris , Touré Sokhna A. , Koffi Jean‐Jacques , Dial Cherif , Monnereau Alain , Diomande Isidore , Tanon Aristophane , Seydi Moussa , Dabis François , Diop Saliou , Koffi Gustave ,   The IeDEA West Africa Collaboration
Published: June 2021

AbstractNon‐Hodgkin lymphomas (NHL) are underestimated causes of cancer in West Africa where chronic viral hepatitis and HIV are endemic. While the association with HIV infection has already been characterized, limited information is available on the association between chronic viral hepatitis and NHL in sub‐Saharan Africa. A case‐control study was conducted in referral hospitals of Abidjan (Cote d'Ivoire) and Dakar (Senegal). Cases of NHL were matched with controls on age, gender and participating site. The diagnosis of NHL relied on local pathological examination completed with immunohistochemistry. HIV, HBV and HCV serology tests were systematically performed. A conditional logistic regression model estimated the associations by the Odds Ratio (OR) with their 95% confidence interval (CI). A total of 117 NHL cases (Abidjan n = 97, Dakar n = 20) and their 234 matched controls were enrolled. Cases were predominantly men (68.4%) and had a median age of 50 years (IQR 37‐57). While Diffuse Large B‐cell lymphoma were the most reported morphological type (n = 35) among mature B‐cell NHL, the proportion mature T‐cell NHL (30%) was high. The prevalence figures of HBV, HCV and HIV infection were 12.8%, 7.7% and 14.5%, respectively among cases of NHL. In multivariate analysis, HBV, HCV and HIV were independently associated with NHL with OR of 2.23 (CI 1.05‐4.75), 4.82 (CI 1.52‐15.29) and 3.32 (CI 1.54‐7.16), respectively. Chronic viral hepatitis B and C were significantly associated with NHL in West Africa. Timely preventive measures against HBV infection and access to curative anti‐HCV treatment might prevent a significant number of NHL.