bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formate and potassium ions affect Escherichia coli proton ATPase activity at low pH during mixed carbon fermentation
Authors: Gevorgyan Heghine , Trchounian Armen , Trchounian Karen 
Published: December 2019

AbstractEscherichia coli is able to ferment not only single but also mixtures of carbon sources. The formate metabolism and effect of formate on various enzymes have been extensively studied during sole glucose but not mixed carbon sources utilization. It was revealed that in membrane vesicles (MV) of wild type cells grown at pH 7.5 during fermentation of the mixture of glucose (2 g/L), glycerol (10 g/L), and formate (0.68 g/L), in the assays, the addition of formate (10 mM) increased the N,N′‐dicyclohexylcarbodiimide (DCCD)‐inhibited ATPase activity on ~30% but no effect of potassium ions (100 mM) had been detected. In selC (coding formate dehydrogenases) and fdhF (coding formate dehydrogenase H) single mutants, formate increased DCCD‐inhibited ATPase activity on ~40 and ~70%, respectively. At pH 5.5, in wild type cells MV, formate decreased the DCCD‐inhibited ATPase activity ~60% but unexpectedly in the presence of potassium ions, it was stimulated ~5.8 fold. The accessible SH or thiol groups number in fdhF mutant was less by 28% compared with wild type. In formate assays, the available SH groups number was less ~10% in wild type but not in fdhF mutant. Taken together, the data suggest that proton ATPase activity depends on externally added formate in the presence of potassium ions at low pH. This effect might be regulated by the changes in the number of redox‐active thiol groups via formate dehydrogenase H, which might be directly related to proton ATPase FO subunit.
A combined Raman spectroscopy, cathodoluminescence, and electron backscatter diffraction study of kyanite porphyroblasts from diamondiferous and diamond‐free metamorphic rocks (Kokchetav massif)
Authors: Rezvukhina Olga V. , Korsakov Andrey V. , Rezvukhin Dmitriy I. , Zamyatin Dmitry A. , Zelenovskiy Pavel S. , Greshnyakov Evgeny D. , Shur Vladimir Ya. 
Published: December 2019

AbstractA series of precise nondestructive analytical methods (Raman spectroscopy, cathodoluminescence, and EBSD—electron backscatter diffraction) has been employed to investigate the internal textures of kyanite porphyroblasts from diamondiferous and diamond‐free ultrahigh‐pressure metamorphic rocks (Kokchetav massif, Northern Kazakhstan). Such internal kyanite characteristics as twinning, radial fibrous pattern, and spotty zoning were identified by means of Raman and cathodoluminescence imaging, whereas an intergrowth of two kyanite crystals was distinguished only by Raman imaging. The EBSD analysis recorded an ~10–25° changing of orientations along the elongation in the investigated kyanite porphyroblasts. The absence of a radial fibrous pattern and a spotty zoning on the EBSD maps indicates that these textures are not related to variations in crystallographic orientation. The absence of clear zoning patterns (cores, mantles, and rims) on the Raman, cathodoluminescence, or EBSD maps of the kyanite porphyroblasts indicates the rapid single‐stage formation of these porphyroblasts near the peak metamorphic conditions and the lack of recrystallization processes. The obtained results provide important implications for deciphering of mineral internal textures, showing that the data obtained by cathodoluminescence mapping can be clearly reproduced by Raman imaging, with the latter method occasionally being even more informative. This observation is of significant importance for the study of minerals that are unexposed on a thin section surface or Fe‐ and Ni‐rich minerals that do not show luminescence emission. The combination of the Raman spectroscopic, cathodoluminescence, and EBSD techniques may provide better spatial resolution for distinguishing different domains and textural peculiarities of mineral than the selective application of individual approaches.
Sensory properties of yellow pea and macadamia honeys from conventional and flow hive extraction methods
Authors: Grace Emily , Olarte Mantilla Sandra Milena , Sunarharum Wenny Bekti , Ong Cheng Mun , Waanders Jennifer , DʼArcy Bruce Robert , Smyth Heather Eunice 
Published: December 2019

AbstractBACKGROUNDThe process of harvesting honey is time consuming and labor intensive. A new system, the Flow Frame, has drastically simplified the harvesting process, enabling honey to be extracted directly from the hive with minimal processing. The sensory profile of honey is influenced, first, by botanical origin and subsequently by processing and storage parameters. A reduction in harvest processing may thus influence the sensory profile of honey harvested from FFs compared to that of honey produced from conventional processing. To test this hypothesis, two monofloral honeys (macadamia and yellow pea) were harvested from FFs, or by conventional honey extraction. Sensory profiling using conventional descriptive analysis was carried out for each floral source with an experienced trained panel.RESULTSThe two monofloral honeys harvested using the FF system had significantly (p < 0.05) higher floral and cleaner aftertaste sensory scores than the honey extracted using commercial (C) methods that involve the use of heat and centrifugation.CONCLUSIONThe flow system retains honey's natural sensory properties compared to harvesting methods that require heat and centrifugation. © 2019 Society of Chemical Industry
Separation of the mineral oil aromatic hydrocarbons of three and more aromatic rings from those of one or two aromatic rings
Authors: Koch Michael , Becker Erik , Päch Michael , Kühn Susanne , Kirchhoff Erhard 
Published: December 2019

AbstractAn analytical method was developed for the quantitation of the mineral oil aromatic hydrocarbons in cosmetic raw materials separating those of one or two aromatic rings from those of three and more aromatic rings. Normal phase high performance liquid chromatography was used with donor‐acceptor complex chromatography. The composition of both fractions and the quantities of respective compounds were determined by comprehensive two dimensional gas chromatography with time of flight mass spectrometry and by liquid chromatography coupled to gas chromatography with flame ionization detection.
Development of a needle trap device packed with titanium‐based metal‐organic framework sorbent for extraction of phenolic derivatives in air
Authors: Firoozichahak Ali , Bahrami Abdulrahman , Ghorbani Shahna Farshid , Alizadeh Saber , Nematollahi Davood , Farhadian Maryam 
Published: December 2019

AbstractWe developed a novel method of needle trap device packed with titanium‐based metal‐organic framework for the extraction of phenolic derivatives in air followed by gas chromatography‐flame ionization detector analysis. The synthetized adsorbent was packed inside a 22‐gauge spinal needle. This method was first tested at laboratory scale, and then was used for field sampling of phenolic derivatives in air. A glass chamber placed on a heater at 60°C was used to provide different concentrations of phenolic derivatives. The desorption conditions and breakthrough volume were optimized using response surface methodology. The limit of detection and limit of quantitation of the proposed method were estimated to be in the range of 0.001–0.12 and 0.003–0.62 ng/mL, respectively, indicating a high sensitivity for the suggested sampler. Storing the packed needle trap device in a refrigerator at 4˚C for 60 days did not dramatically affect the storage stability. Our findings indicated that there was a high correlation coefficient (R2 = 0.99) between the measurement results of this method and the NIOSH recommended method (XAD‐7 sorbent tube). Therefore, it can be concluded that the needle trap device packed with titanium‐based metal‐organic framework can be used as a efficient method for extraction of phenolic derivatives in air.
Hydrogen Peroxide and Glutathione Dual Redox‐Responsive Nanoparticles for Controlled DOX Release
Authors: Chen Runhai , Ma Zhifang , Xiang Zehong , Xia Yu , Shi Qiang , Wong Shing‐Chung , Yin Jinghua 
Published: December 2019

AbstractPolymer nanoparticulate drug delivery systems that respond to reactive oxygen species (ROS) and glutathione (GSH) simultaneously at biologically relevant levels hold great promise to improve the therapeutic efficacy to cancer cells with reduced side effects of chemo drugs. Herein, a novel redox dual‐responsive amphiphilic block copolymer (ABP) that consists of a hydrophilic poly (ethylene oxide) block and a hydrophobic block bearing disulfide linked phenylboronic ester group as pendant is synthesized, and the DOX loaded nanoparticles (BSN‐DOX) based on ABPs with varied hydrophobic block length are fabricated for DOX delivery. The self‐immolative leaving reaction of phenylboronic ester triggered by extracellular ROS and the cleavage of disulfide linkages induced by intracellular GSH both lead to rapid DOX release from BSN‐DOX, resulting in an on‐demand DOX release. Moreover, BSN‐DOX show better tumor inhibition and lower side effects in vivo compared with free drug.
Microwave‐Assisted Reversible Addition–Fragmentation Chain Transfer Polymerization of Cationic Monomers in Mixed Aqueous Solvents
Authors: Tran Jonathan D. , Mikulec Sydney N. , Calzada Oscar M. , Prossnitz Alexander N. , Ennis Amanda F. , Sherwin William J. , Magsumbol Alisson S. , Jameson Alexandra , Schellinger Joan G. 
Published: December 2019

AbstractCationic polymers are an interesting class of macromolecules due to their versatility and emerging properties that can be used for various industrial and biomedical purposes. This report is focused on investigating the use of microwave heating in the reversible addition–fragmentation chain transfer polymerization of functional cationic monomers, N‐(3‐aminopropyl)methacrylamide hydrochloride (APMA) and N‐[3‐(dimethylamino)propyl]methacrylamide (DMAPMA). Under comparable polymerization reaction conditions, the microwave‐assisted reaction achieves up to 270% (APMA) and 375% (DMAPMA) rate enhancement over conventional oil‐bath mediated set‐up. Linear relationships are observed between number average molecular weight and monomer conversion for different target degrees of polymerization to give low‐ to high‐molecular‐weight cationic polymers. Chain extension experiments show increase in molecular weight of the cationic polymers with narrow dispersities (Ð < 1.2) indicating retention of the chain transfer agent with no observable aminolysis or hydrolysis during polymerization.
A Facile Preparation of Mussel‐Inspired Poly(dopamine phosphonate‐co‐PEGMA)s via a One‐Pot Multicomponent Polymerization System
Authors: Zhang Yaling , Zhao Yuan , Xia Shuang , Tao Lei , Wei Yen 
Published: December 2019

AbstractMussel‐inspired polymers attract much research interest due to their potential as effective adhesives. In this work, a new kind of mussel‐inspired polymer, poly(dopamine phosphonate‐co‐PEGMA), is prepared via a one‐pot multicomponent polymerization system. The multicomponent polymerization system refers to a combination of multicomponent Kabachnik–Fields (KF) reaction and reversible addition‐fragmentation chain transfer (RAFT) polymerization system. Reactants are converted to dopamine phosphonate monomers in situ through the KF reaction and polymerized simultaneously along with poly(ethylene glycol methyl ether) methacrylate (PEGMA) co‐monomers by the RAFT process in a one‐pot operation. Target polymers with dopamine phosphonate as side groups and well‐defined polymer structures are thus facilely and successfully prepared. Afterwards, a series of polymers with various ratios of dopamine phosphonates as well as the crosslinked polymer analogues are prepared. Benefiting from the dopamine phosphonate side groups, aqueous solutions of those polymers show potential as effective adhesives in both dry and wet conditions, and their adhesive strengths are highly related to ratios of dopamine phosphonates in the polymers. Those polymers are non‐cytotoxic and show strong bonding affinities on various substrates including metals, polymers, and bovine bones, suggesting their potential as environmentally friendly general adhesives in broad areas.
Application of radiomics for the prediction of HPV status for patients with head and neck cancers
Authors: Bagher‐Ebadian Hassan , Lu Mei , Siddiqui Farzan , Ghanem Ahmed I. , Wen Ning , Wu Qixue , Liu Chang , Movsas Benjamin , Chetty Indrin J. 
Published: December 2019

PurposeTo perform radiomic analysis of primary tumors extracted from pretreatment contrast‐enhanced computed tomography (CE‐CT) images for patients with oropharyngeal cancers to identify discriminant features and construct an optimal classifier for the characterization and prediction of human papilloma virus (HPV) status.Materials and methodsOne hundred and eighty seven patients with oropharyngeal cancers with known HPV status (confirmed by immunohistochemistry—p16 protein testing) were retrospectively studied as follows: Group A: 95 patients (19HPV− and 76HPV+) from the MICAII grand challenge. Group B: 92 patients (52HPV− and 40HPV+) from our institution. Radiomic features (172) were extracted from pretreatment diagnostic CE‐CT images of the gross tumor volume (GTV). Levene and Kolmogorov–Smirnov's tests with absolute biserial correlation (>0.48) were used to identify the discriminant features between the HPV+ and HPV− groups. The discriminant features were used to train and test eight different classifiers. Area under receiver operating characteristic (AUC), positive predictive and negative predictive values (PPV and NPV, respectively) were used to evaluate the performance of the classifiers. Principal component analysis (PCA) was applied on the discriminant feature set and seven PCs were used to train and test a generalized linear model (GLM) classifier.ResultsAmong 172 radiomic features only 12 radiomic features (from 3 categories) were significantly different (P < 0.05, |BSC| > 0.48) between the HPV+ and HPV− groups. Among the eight classifiers trained and applied for prediction of HPV status, the GLM showed the highest performance for each discriminant feature and the combined 12 features: AUC/PPV/NPV = 0.878/0.834/0.811. The GLM high prediction power was AUC/PPV/NPV = 0.849/0.731/0.788 and AUC/PPV/NPV = 0.869/0.807/0.870 for unseen test datasets for groups A and B, respectively. After eliminating the correlation among discriminant features by applying PCA analysis, the performance of the GLM was improved by 3.3%, 2.2%, and 1.8% for AUC, PPV, and NPV, respectively.ConclusionsResults imply that GTV's for HPV+ patients exhibit higher intensities, smaller lesion size, greater sphericity/roundness, and higher spatial intensity‐variation/heterogeneity. Results are suggestive that radiomic features primarily associated with the spatial arrangement and morphological appearance of the tumor on contrast‐enhanced diagnostic CT datasets may be potentially used for classification of HPV status.
Synthetic CT generation from CBCT images via deep learning
Authors: Chen Liyuan , Liang Xiao , Shen Chenyang , Jiang Steve , Wang Jing 
Published: December 2019

PurposeCone‐beam computed tomography (CBCT) scanning is used daily or weekly (i.e., on‐treatment CBCT) for accurate patient setup in image‐guided radiotherapy. However, inaccuracy of CT numbers prevents CBCT from performing advanced tasks such as dose calculation and treatment planning. Motivated by the promising performance of deep learning in medical imaging, we propose a deep U‐net‐based approach that synthesizes CT‐like images with accurate numbers from planning CT, while keeping the same anatomical structure as on‐treatment CBCT.MethodsWe formulated the CT synthesis problem under a deep learning framework, where a deep U‐net architecture was used to take advantage of the anatomical structure of on‐treatment CBCT and image intensity information of planning CT. U‐net was chosen because it exploits both global and local features in the image spatial domain, matching our task to suppress global scattering artifacts and local artifacts such as noise in CBCT. To train the synthetic CT generation U‐net (sCTU‐net), we include on‐treatment CBCT and initial planning CT of 37 patients (30 for training, seven for validation) as the input. Additional replanning CT images acquired on the same day as CBCT after deformable registration are utilized as the corresponding reference. To demonstrate the effectiveness of the proposed sCTU‐net, we use another seven independent patient cases (560 slices) for testing.ResultsWe quantitatively compared the resulting synthetic CT (sCT) with the original CBCT image using deformed same‐day pCT images as reference. The averaged accuracy measured by mean absolute error (MAE) between sCT and reference CT (rCT) on testing data is 18.98 HU, while MAE between CBCT and rCT is 44.38 HU.ConclusionsThe proposed sCTU‐net can synthesize CT‐quality images with accurate CT numbers from on‐treatment CBCT and planning CT. This potentially enables advanced CBCT applications for adaptive treatment planning.
Placental infection of hepatitis B virus among Thai pregnant women: Clinical risk factors and its association with fetal infection
Authors: Sirilert Sirinart , Khamrin Pattara , Kumthip Kattareeya , Malasao Rungnapa , Maneekarn Niwat , Tongsong Theera 
Published: December 2019

AbstractObjectivesTo identify the risk factors of placental and fetal infections among HBsAg‐positive women.MethodsA prospective cohort study involving HBsAg‐positive pregnant women was conducted. Maternal risk factors, including serum HBeAg status, anti‐HBcIgM, and HBV‐DNA levels, were determined. Placental infection was identified by PCR and confirmed by DNA sequencing. Fetal infection was defined as a positive umbilical cord blood HBV‐DNA at birth.ResultsA total of 96 HBsAg‐positive women were enrolled in the study. The prevalence of placental infection was high (44 of 96; 45.8%) among HBsAg‐positive women. The major risk factors for placental infection were high maternal viral load and the presence of HBeAg. Fetal infection was detected in one quarter of HBsAg‐positive women (25 of 95; 25.3%). The risk of fetal infection was strongly associated with placental infection (78.3%), high maternal viral load, and the presence of HBeAg. There was no significant difference in perinatal outcomes between the groups with and without placental infection. Data on rates of chronic HBV infection in infants after fetal infection were not available.ConclusionA significant association between maternal measures of viral replication and placental and fetal infection was demonstrated. These findings suggest that transplacental infection prior to birth may be a mechanism contributing to the higher rates of newborn prophylaxis failure in women with a high viral load.
Electroactive polythiophene/polystyrene bottlebrushes as morphology compatibilizers in photovoltaic systems
Authors: Sarvari Raana , Agbolaghi Samira , Massoumi Bakhshali , Sorkhishams Nafiseh 
Published: December 2019

AbstractPoly(3‐thiophene ethanol) (P3ThEt)‐graft‐polystyrene (PSt) bottlebrushes were synthesized and applied in active layers of poly(3‐hexylthiophene) (P3HT):phenyl‐C71‐butyric acid methyl ester (PC71BM) solar cells as morphology compatibilizers. In the presence of 15 wt% of P3ThEt‐graft‐PSt bottlebrush compatibilizers, the P3HT crystallite dimensions (D(100) = 45.67 nm and D(020) = 30.12 nm) and Rmean (38.96 nm) of PCBM clusters were the largest and the layer spacings were all the smallest (d(100) = 1.054 nm, d(020) = 0.301 nm and d(PCBM) = 0.406 nm). These dimensional properties led to better hole (1.9 × 10−3 cm2 V−1 s−1) and electron (1.2 × 10−2 cm2 V−1 s−1) mobilities. The content of bottlebrushes was optimized at 15 wt%, and thereby the best photovoltaic results including the maximum cell efficiency of 5.37% were obtained for this turning point (12.75 mA cm−2, 61%, 0.69 V). On exceeding the optimum weight percentage, all photovoltaic parameters decreased markedly and reached even less than that of pristine devices (1.92% versus 2.24%). After an optimum weight percentage of compatibilizers, further enhancement in bottlebrush content in active layers saturated and finally oversaturated the system and, consequently, the cell parameters significantly decreased. Accumulation of bottlebrushes in interfaces and donor/acceptor phases ruined the system function even with large and packed P3HT crystallites and PC71BM clusters. © 2019 Society of Chemical Industry
A facile light‐trapping approach for ultrathin GaAs solar cells using wet chemical etching
Authors: van Eerden Maarten , Bauhuis Gerard J. , Mulder Peter , Gruginskie Natasha , Passoni Marco , Andreani Lucio C. , Vlieg Elias , Schermer John J. 
Published: December 2019

AbstractThinning down the absorber layer of GaAs solar cells can reduce their cost and improve their radiation hardness, which is important for space applications. However, the lighttrapping schemes necessary to achieve high absorptance in these cells can be experimentally challenging or introduce various parasitic losses. In this work, a facile light‐trapping approach based on wet chemical etching is demonstrated. The rear‐side contact layer of ultrathin GaAs solar cells is wet‐chemically textured in between local Ohmic contact points using an NaOH‐based etchant. The resulting contact layer morphology is characterized using atomic force microscopy and scanning electron miscroscopy. High broadband diffuse reflectance and haze factors are measured on bare and Ag‐coated textured contact layers. The textured contact layer is successfully integrated as a diffusive rear mirror in thin‐film solar cells comprising a 300‐nm GaAs absorber and Ag rear contact. Consistent increases in short‐circuit current density (JSC) of approximately 3 mA cm−2 (15%) are achieved in the textured cells, while the open‐circuit voltages and fill factors do not suffer from the textured rear mirror. The best cell achieves a JSC of 24.8 mA cm−2 and a power conversion efficiency of 21.4%. The textured rear mirror enhances outcoupling of luminescence at open circuit, leading to a strong increase in the external luminescent efficiency.
Evolution of resistance to HPPD‐inhibiting herbicides in a wild radish population via enhanced herbicide metabolism
Authors: Lu Huan , Yu Qin , Han Heping , Owen Mechelle J , Powles Stephen B 
Published: December 2019

AbstractBACKGROUNDRelatively new herbicides that target 4‐hydroxyphenylpyruvate dioxygenase (HPPD) are now available for use on the world's great grain crops (rice, wheat, corn and soybean) and for other uses. With widespread and persistent use of HPPD‐inhibiting herbicides, the evolution of HPPD‐inhibiting herbicide resistant weeds is inevitable. Currently, resistance to HPPD‐inhibiting herbicides is known in two weed species, waterhemp and Palmer amaranth. Here, we report a HPPD‐inhibiting herbicide resistant wild radish population from the Western Australia grain belt. This population was not selected with HPPD‐inhibiting herbicides, rather it evolved resistance to earlier used herbicides with different modes of action and exhibits cross‐resistance to HPPD‐inhibiting herbicides.RESULTSDose–response experiments showed the resistant (R) population exhibits 4 to 6.5‐fold resistance to the HPPD‐inhibiting herbicides mesotrione, tembotrione and isoxaflutole, compared to the susceptible (S) population. This resistance is not target‐site based as cloning of full coding sequences of the HPPD genes from S and R plants did not reveal resistance‐endowing single nucleotide polymorphisms. The HPPD gene expression levels are similar in S and R plants. In addition, no differences in [14C]‐mesotrione uptake and translocation were observed in the S and R plants. However, the time required for R plants to metabolise 50% [14C]‐mesotrione is 7.7‐fold faster than for the S plants.CONCLUSIONWe confirm resistance to HPPD‐inhibiting herbicides exists in a population of the economically damaging global weed wild radish. The resistance in this population is due to a non‐target‐site based enhanced rate of herbicide metabolism. © 2019 Society of Chemical Industry