bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methicillin and Inducible Clindamycin-resistant Staphylococcus aureus Isolates from Clinical Samples in Abia State
Authors: Ifediora A. C. , Nwabueze R. N. , Amadi E. S. , Chikwendu C. I. 
Published: November 2019

Staphylococcus aureus is a major bacterial pathogen that causes different community and hospital-acquired infections. S. aureus resistant to methicillin has become a big and expanding problem of concern in many developing countries. Clindamycin has also been discovered to be a preferred therapeutic alternative for the treatment of both methicillin susceptible and resistant staphylococcal infections. This study examined the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples of patients in Abia state, Nigeria using standard recommended procedures. A total of 750 clinical specimens of blood and urine samples, wound, ear, nasal, high vaginal and ear swabs were collected from three major health facilities in Abia state, Nigeria. Each sample was cultured for bacterial isolates and examined for colonial and cellular morphology while biochemical identification was performed. Antimicrobial susceptibility test was performed on Mueller-Hinton agar (MHA) by disc diffusion method and MRSA screening was done using cefoxitin disc. A total of 265 (35.3%) S. aureus isolates were recovered, out of which 126(47.5%) were from males and 139(52.5%) were from females, however there was no association between the prevalence and gender (p-value = 0.05) and also prevalence and age (p-value = 0.52). Of the 265 S. aureus isolates recovered, 164(61.9%) were MRSA. All 100% of the MRSA were susceptible to vancomycin, 120(73.2%) to clindamycin, 92(56.1%) to gentamycin. All 100% were resistant to ceftazidine, 157(95.7%) to cloxacillin, 146(89.0%) to augmentin, 136(82.9%) to ceftriaxone and 103(61.6%) to erythromycin. The MRSA strains showed much higher resistance rate than their MSSA counterparts to all tested antibiotic except clindamycin. 64(39.0%) of the MRSA were resistant to 4 classes of antibiotics indicating multi drug resistance (MDR). The overall prevalence of inducible clindamycin resistance among methicillin resistant isolates was 29(17.7%). This implies that 17.7% could have been misidentified as clindamycin susceptible by Kirby-Bauer disk diffusion method. In conclusion prevalence of MRSA was high and it is important to routinely carry out the D-test for detection of inducible clindamycin resistance if clindamycin is considered as a treatment option.
Chiral Supraparticles for Controllable Nanomedicine
Authors: Yeom Jihyeon , Guimaraes Pedro P. G. , Ahn Hyo Min , Jung Bo‐Kyeong , Hu Quanyin , McHugh Kevin , Mitchell Michael J. , Yun Chae‐Ok , Langer Robert , Jaklenec Ana 
Published: November 2019

AbstractChirality is ubiquitous in nature and hard‐wired into every biological system. Despite the prevalence of chirality in biological systems, controlling biomaterial chirality to influence interactions with cells has only recently been explored. Chiral‐engineered supraparticles (SPs) that interact differentially with cells and proteins depending on their handedness are presented. SPs coordinated withd‐chirality demonstrate greater than threefold enhanced cell membrane penetration in breast, cervical, and multiple myeloma cancer cells. Quartz crystal microbalance with dissipation and isothermal titration calorimetry measurements reveal the mechanism of these chiral‐specific interactions. Thermodynamically,d‐SPs show more stable adhesion to lipid layers composed of phospholipids and cholesterol compared tol‐SPs. In vivo,d‐SPs exhibit superior stability and longer biological half‐lives likely due to opposite chirality and thus protection from endogenous proteins including proteases. This work shows that incorporatingd‐chirality into nanosystems enhances uptake by cancer cells and prolonged in vivo stability in circulation, providing support for the importance of chirality in biomaterials. Thus, chiral nanosystems may have the potential to provide a new level of control for drug delivery systems, tumor detection markers, biosensors, and other biomaterial‐based devices.
Mass transfer in continuous mixtures with Maxwell–Stefan diffusion using the adaptive characterization method
Authors: Moraes Antonio O. S. , Lage Paulo L. C. , Silva Luiz Fernando L. R. 
Published: November 2019

AbstractThe adaptive pseudocomponent characterization method for continuous mixtures was extended to mass transfer problems using the Maxwell–Stefan diffusion model. It is based on the direct quadrature method of moments (DQMoM), using a quadrature rule to discretize the molar fraction distribution of the continuous mixture. The solution method was applied to two one‐dimensional mass transfer problems: the transient diffusion in a Loschmidt tube and the steady‐state diffusion in a thin film. In the latter, it was showed that the DQMoM equations reduce to an equivalent problem with a fixed characterization and solution methods for linearized theory problems can be employed. For these two problems, the proposed method was verified against the discrete component model (DCM), whose implementation was also verified against existing solutions. Results showed that the adaptive method with five pseudocomponents predicts the mixture properties with maximum relative deviation smaller than 1% when compared to the DCM with 57 components.
Photodiode‐like behavior of jelly dye‐sensitized donor‐acceptor dendrimers
Authors: Pires Rita F. , Charas Ana , Morgado Jorge , Casimiro Teresa , Bonifácio Vasco D. B. 
Published: November 2019

ABSTRACTHybrid photodiodes (HPD) systems are on the rise. The growing interest on these devices is mainly due to their power in image sensing and bioengineering solutions. In this work, a new class of donor‐acceptor dendrimers was synthesized and incorporated, along with a ruthenium sensitizer dye, into low cost devices comprised of one single layer of a biocompatible matrix (agarose). Exploring different electrodes, low current devices with a counter‐electrode dependent response have been successfully assembled at room temperature. Using a stainless steel electrode, sensitized donor‐acceptor dendrimers provide photodiode‐like systems having nA dark currents. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48635.
Synthesis and Penicillin‐binding Protein Inhibitory Assessment of Dipeptidic 4‐Phenyl‐β‐lactams from α‐Amino Acid‐derived Imines
Authors: Decuyper Lena , Jukič Marko , Sosič Izidor , Amoroso Ana Maria , Verlaine Olivier , Joris Bernard , Gobec Stanislav , D'hooghe Matthias 
Published: November 2019

AbstractMonocyclic β‐lactams revive the research field on antibiotics, which are threatened by the emergence of resistant bacteria. A six‐step synthetic route was developed, providing easy access to new 3‐amino‐1‐carboxymethyl‐4‐phenyl‐β‐lactams, of which the penicillin‐binding protein (PBP) inhibitory potency was demonstrated biochemically.
Cu‐Catalyzed Selective Oxy‐Cyanoalkylation of Allylamines with Cycloketone Oxime Esters and CO2
Authors: Ran Chuan‐Kun , Huang He , Li Xing‐Hui , Wang Wei , Ye Jian‐Heng , Yan Si‐Shun , Wang Bi‐Qin , Feng Chun , Yu Da‐Gang 
Published: November 2019

Summary of main observation and conclusionThe radical‐initiated carboxylative cyclization of allylamines with CO2 represents an efficient and highly promising strategy to afford valuable 2‐oxazolidinones. However, the radical precursors and pathways to generate radicals in such processes are still limited. Herein, we report the first Cu‐catalyzed selective oxy‐cyanoalkylation of allylamines with cycloketone oxime esters and CO2 via C—C bond cleavage. Many cyanoalkyl‐substituted 2‐oxazolidinones are obtained in moderate to good yields with high regio‐ and chemo‐selectivities. The utility of this redox‐neutral and cyanide‐free method is demonstrated with mild conditions, broad substrate scope, good functional group tolerance and easy scalability.
Synthesis of CF2H‐Containing Oxime Ethers Derivatives from ClCF2H, tert‐Butyl Nitrile and Indoles
Authors: Ma Xingxing , Huang Hua , Su Jianke , Song Zhiyi , Nakano Tamaki , Song Qiuling 
Published: November 2019

Summary of main observation and conclusionA new and intriguing methodology to access various O‐difluoromethylation oxime compounds from ClCF2H, TBN and indoles is developed under mild reaction conditions. This strategy can suppress N‐difluoromethylation of indoles successfully, in which there are two different active species (:CF2 and ·NO) while indoles are unprotected, featuring simple operation and radical involvement.
Classification of Human White Blood Cells Using Machine Learning for Stain‐Free Imaging Flow Cytometry
Authors: Lippeveld Maxim , Knill Carly , Ladlow Emma , Fuller Andrew , Michaelis Louise J , Saeys Yvan , Filby Andrew , Peralta Daniel 
Published: November 2019

AbstractImaging flow cytometry (IFC) produces up to 12 spectrally distinct, information‐rich images of single cells at a throughput of 5,000 cells per second. Yet often, cell populations are still studied using manual gating, a technique that has several drawbacks, hence it would be advantageous to replace manual gating with an automated process. Ideally, this automated process would be based on stain‐free measurements, as the currently used staining techniques are expensive and potentially confounding. These stain‐free measurements originate from the brightfield and darkfield image channels, which capture transmitted and scattered light, respectively. To realize this automated, stain‐free approach, advanced machine learning (ML) methods are required. Previous works have successfully tested this approach on cell cycle phase classification with both a classical ML approach based on manually engineered features, and a deep learning (DL) approach. In this work, we compare both approaches extensively on the problem of white blood cell classification. Four human whole blood samples were assayed on an ImageStream‐X MK II imaging flow cytometer. Two samples were stained for the identification of eight white blood cell types, while two other sample sets were stained for the identification of resting and active eosinophils. For both data sets, four ML classifiers were evaluated on stain‐free imagery with stratified 5‐fold cross‐validation. On the white blood cell data set, the best obtained results were 0.778 and 0.703 balanced accuracy for classical ML and DL, respectively. On the eosinophil data set, this was 0.871 and 0.856 balanced accuracy. We conclude that classifying cell types based on only stain‐free images is possible with all four classifiers. Noteworthy, we also find that the DL approaches tested in this work do not outperform the approaches based on manually engineered features. © 2019 International Society for Advancement of Cytometry
Invasion promotes invasion: Facilitation of C3 perennial grass dominance in mixed C3/C4 grassland by an invasive C3 woody sprouter (Prosopis glandulosa)
Authors: Ansley Robert James , Cooper Caitlyn , Zhang Tian 
Published: November 2019

Abstract

In the Southern Great Plains (SGP) of the United States, encroachment of the native invasive woody legume, honey mesquite (Prosopis glandulosa Torr.), has caused a decline in C4 mid‐grass abundance. Prosopis glandulosa invasion has also facilitated growth of the C3 mid‐grass species, Texas wintergrass (Nassella leucotricha [Trin & Rupr.] Pohl) initially beneath its canopy but extending to interspaces between P. glandulosa as stand density increases. Little is known about the stability of the Prosopis/Nassella association or C4 grass recovery following P. glandulosa disturbance.

We quantified C3 and C4 grass production in interspaces, and basal cover in interspaces and P. glandulosa subcanopy microsites for 9 years following P. glandulosa suppression (top‐kill) and compared this to untreated P. glandulosa woodland (woodland).

The Prosopis/Nassella association limited the window of C4 mid‐grass recovery to only a few years. Nassella leucotricha dominated grass production during the first 3 years after top‐kill. C4 mid‐grass recovery began in year 4, but was interrupted by severe drought in years 5 through 7. Recovery resumed in year 8, due to above‐average summer rainfall, but P. glandulosa regrowth was large enough by this time to limit C4 mid‐grass production to a third of its potential.

Nassella leucotricha basal cover remained dominant and stable in woodland subcanopy microsites, even during drought, and only briefly declined in top‐kill subcanopy microsites before returning to pretreatment levels by year 8 as P. glandulosa regrowth increased and provided shade.

Synthesis and applications. A single suppression event had little impact on disrupting the Prosopis/Nassella association and allowing C4 mid‐grass recovery. The coupling of a deciduous, N‐fixing C3 woody species with this C3 perennial grass may be a vegetative “state” that is resistant to multiple woody suppression disturbances and permanently limits the transition back to C4 grassland.
Large‐scale dynamic causal modeling of major depressive disorder based on resting‐state functional magnetic resonance imaging
Authors: Li Guoshi , Liu Yujie , Zheng Yanting , Li Danian , Liang Xinyu , Chen Yaoping , Cui Ying , Yap Pew‐Thian , Qiu Shijun , Zhang Han , Shen Dinggang 
Published: November 2019

AbstractMajor depressive disorder (MDD) is a serious mental illness characterized by dysfunctional connectivity among distributed brain regions. Previous connectome studies based on functional magnetic resonance imaging (fMRI) have focused primarily on undirected functional connectivity and existing directed effective connectivity (EC) studies concerned mostly task‐based fMRI and incorporated only a few brain regions. To overcome these limitations and understand whether MDD is mediated by within‐network or between‐network connectivities, we applied spectral dynamic causal modeling to estimate EC of a large‐scale network with 27 regions of interests from four distributed functional brain networks (default mode, executive control, salience, and limbic networks), based on large sample‐size resting‐state fMRI consisting of 100 healthy subjects and 100 individuals with first‐episode drug‐naive MDD. We applied a newly developed parametric empirical Bayes (PEB) framework to test specific hypotheses. We showed that MDD altered EC both within and between high‐order functional networks. Specifically, MDD is associated with reduced excitatory connectivity mainly within the default mode network (DMN), and between the default mode and salience networks. In addition, the network‐averaged inhibitory EC within the DMN was found to be significantly elevated in the MDD. The coexistence of the reduced excitatory but increased inhibitory causal connections within the DMNs may underlie disrupted self‐recognition and emotional control in MDD. Overall, this study emphasizes that MDD could be associated with altered causal interactions among high‐order brain functional networks.
Crystallized and fluid intelligence are predicted by microstructure of specific white‐matter tracts
Authors: Góngora Daylín , Vega‐Hernández Mayrim , Jahanshahi Marjan , Valdés‐Sosa Pedro A. , Bringas‐Vega Maria L. ,   CHBMP
Published: November 2019

AbstractStudies of the neural basis of intelligence have focused on comparing brain imaging variables with global scales instead of the cognitive domains integrating these scales or quotients. Here, the relation between mean tract‐based fractional anisotropy (mTBFA) and intelligence indices was explored. Deterministic tractography was performed using a regions of interest approach for 10 white‐matter fascicles along which the mTBFA was calculated. The study sample included 83 healthy individuals from the second wave of the Cuban Human Brain Mapping Project, whose WAIS‐III intelligence quotients and indices were obtained. Inspired by the “Watershed model” of intelligence, we employed a regularized hierarchical Multiple Indicator, Multiple Causes model (MIMIC), to assess the association of mTBFA with intelligence scores, as mediated by latent variables summarizing the indices. Regularized MIMIC, used due to the limited sample size, selected relevant mTBFA by means of an elastic net penalty and achieved good fits to the data. Two latent variables were necessary to describe the indices: Fluid intelligence (Perceptual Organization and Processing Speed indices) and Crystallized Intelligence (Verbal Comprehension and Working Memory indices). Regularized MIMIC revealed effects of the forceps minor tract on crystallized intelligence and of the superior longitudinal fasciculus on fluid intelligence. The model also detected the significant effect of age on both latent variables.
Multiparametric Magnetic Resonance Elastography Improves the Detection of NASH Regression Following Bariatric Surgery
Authors: Allen Alina M. , Shah Vijay H. , Therneau Terry M. , Venkatesh Sudhakar K. , Mounajjed Taofic , Larson Joseph J. , Mara Kristin C. , Kellogg Todd A. , Kendrick Michael L. , McKenzie Travis J. , Greiner Suzanne M. , Li Jiahui , Glaser Kevin J. , Wells Michael L. , Gunneson Timothy J. , Ehman Richard L. , Yin Meng 
Published: November 2019

Disease monitoring in nonalcoholic steatohepatitis (NASH) is limited by absence of noninvasive biomarkers of disease regression or progression. We aimed to examine the role of multiparametric three‐dimensional magnetic resonance elastography (3D‐MRE) and magnetic resonance imaging proton density fat fraction (MRI‐PDFF) in the detection of NASH regression after interventions. This is a single‐center prospective clinical trial of 40 patients who underwent bariatric surgery. Imaging and liver biopsies were obtained at baseline and 1 year after surgery. The imaging protocol consisted of multifrequency 3D‐MRE to determine the shear stiffness at 60 Hz and damping ratio at 40 Hz, and MRI‐PDFF to measure the fat fraction. A logistic regression model including these three parameters was previously found to correlate with NASH. We assessed the model performance in the detection of NASH resolution after surgery by comparing the image‐predicted change in NAFLD activity score (delta NAS) to the histologic changes. A total of 38 patients (median age 43, 87% female, 30 of 38 with NAS ≥ 1, and 13 of 38 with NASH) had complete data at 1 year. The NAS decreased in all subjects with NAS ≥ 1 at index biopsy, and NASH resolved in all 13. There was a strong correlation between the predicted delta NAS by imaging and the delta NAS by histology (r = 0.73, P < 0.001). The strength of correlation between histology and the predicted delta NAS using single conventional parameters, such as the fat fraction by MRI‐PDFF or shear stiffness at 60 Hz by MRE, was r = 0.69 (P < 0.001) and r = 0.43 (P = 0.009), respectively. Conclusion: Multiparametric 3D‐MRE and MRI‐PDFF can detect histologic changes of NASH resolution after bariatric surgery. Studies in a nonbariatric setting are needed to confirm the performance as a composite noninvasive biomarker for longitudinal NASH monitoring.
Experimenting LoRa‐compliant solutions in Real‐World Scenarios
Authors: Tresca Giulia , Vista Francesco , Boccadoro Pietro 
Published: November 2019

Long Range (LoRa) is one of the most promising technologies in the context of Low Power Wide Area Networks (LPWANs). Thanks to its unique features, it addresses some of the most representative Internet of Things (IoT) constraints, since it lowers energy footprints over long‐distance communications. In the context of environmental monitoring, many LoRa‐compliant solutions are now available. This work proposes a case‐study analysis of rapid prototyping platforms that leverage both the simplicity and effectiveness of the LoRa technology in the context of outdoor communications. The conducted experimental campaign concretely demonstrated the effects of the Spreading Factor (SF), Bandwidth (BW), and Coding Rate (CR) on the communication range in urban environments. At the same time, results highlighted that, in a 7 km range, the Packet Loss Ratio (PLR) can be as low as 15%.
dGEMRIC and CECT Comparison of Cationic and Anionic Contrast Agents in Cadaveric Human Metacarpal Cartilage
Authors: Freedman Jonathan D. , Ellis Daniel J. , Lusic Hrvoje , Varma Gopal , Grant Aaron K. , Lakin Benjamin A. , Snyder Brian D. , Grinstaff Mark W. 
Published: November 2019

ABSTRACTMagnetic resonance imaging (MRI) and computed tomography (CT) are widely used to image cartilage and their diagnostic capability is enhanced in the presence of contrast agents. The aim of the study is to directly compare the performance between commercial anionic MRI (Gd(DTPA), Gd2−) and CT (Ioxaglate, Iox1−) contrast agents with novel cationic MRI (Gd(DTPA)Lys2, Gd4+) and CT (CA4+) contrast agents for assessment of cartilage mechanical and biochemical properties using the ex vivo human osteoarthritis metacarpal cartilage model. First, indentation testing was conducted to obtain the compressive modulus of the human fifth metacarpals. The samples were then immersed in the anionic and cationic contrast agents prior to delayed gadolinium‐enhanced MRI of cartilage and CT scanning, respectively. The cartilage glycosaminoglycan (GAG) content and distribution were determined using the 1,9‐dimethylmethylene blue assay and Safranin‐O histology. Cationic agents significantly accumulate in cartilage compared with anionic agents. Significant positive correlations (p < 0.05) exist between imaging results of cationic agents and GAG content (Gd4+: R2 = 0.43; CA4+: R2 = 0.67) and indentation equilibrium modulus (Gd4+: R2 = 0.48; CA4+: R2 = 0.77). Significant negative correlations are observed between anionic MRI relaxation times, but not contrast‐enhanced computed tomography attenuation and cartilage GAG content (Gd2−: R2 = 0.56, p < 0.05; Iox1−: R2 = 0.31, p > 0.05) and indentation equilibrium modulus (Gd2−: R2 = 0.38, p < 0.05; Iox1−: R2 = 0.17, p > 0.05). MRI or CT with cationic contrast agents provides greater sensitivity than their anionic analogs at assessing the biochemical and biomechanical properties of ex vivo human metacarpal cartilage. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:719‐725, 2020
An Easy Fabricable Film for Organic Electronics Based on Phenoxy and Epoxy
Authors: Rafiqul Bari Gazi A. K. M. , Kim Haekyoung 
Published: November 2019

AbstractA polymeric substrate is an essential component of a flexible organic electronic device. A novel composition of phenoxy and epoxy resin, phenoxy epoxy polymer (PE polymer), film is fabricated. The process of synthesis and fabrication of the film is optimized. The PE polymer film shows the high optical transmittance of 90.1%. Furthermore, the PE polymer film has exhibited high stability of transparency after humid, UV, IR, acid, and base treatments. The PE polymer film also demonstrates a higher contact angle than the PET, and considerable tensile strength and chemical resistance ability. The PE polymer film provides significant developed barrier ability to allow only 87.2% permeation than the PET film. The new PE polymer film has a high prospect for the flexible organic electronic device as a barrier film or substrate.