bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tetramethylpyrazine reduces the consequences of nitric oxide inhibition in pregnant rats
Authors: Gu Shengyi , Shen Huaxiang , Zhou Yun , Ni Jiaying , Zheng Tao , Mou Zhengqian , Hua Xiaolin 
Published: April 2019

AbstractPre‐eclampsia (PE) is closely associated with perinatal morbidity and mortality and we want to investigate tetramethylpyrazine (TMP)'s effects on PE. Pregnant Sprague–Dawley rats were randomly divided into five groups: normal pregnant (PC), PE, PE+TMP 20 mg/kg, PE+TMP 40 mg/kg, and PE+TMP 60 mg/kg group. The PE rat model was established via L‐NAME treatment. Systolic blood pressures (SBP) and urinary protein concentration were detected via the tail‐cuff method and CBB kit, respectively. mRNA levels of key genes were analyzed via quantitative PCR and protein levels of key genes were measured by ELISA or western blot. TMP decreased SBP and urinary protein concentration of PE rats. TMP inhibited L‐NAME‐induced decrease in pups alive ratio, pups weight, and the ratio of pups/placenta weight and reversed L‐NAME induced changes in placental histology, whereas it had little effect on placental weight. Urinary nephrin and podocin expressions were enhanced and serum placental growth factor level was decreased in PE rats, whereas TMP inhibited the above phenomena. TMP suppressed L‐NAME‐induced sFlt‐1 upregulation in serums and kidneys of PE rats, whereas it downregulated IL‐6 and MCP‐1 expression in PE rats' serums, placentas and kidneys. TMP also suppressed the increase in placental sFlt‐1 and vascular endothelial growth factor level caused by L‐NAME. In addition, TMP inhibited CHOP and GRP78 expressions and decreased the ratio of p‐elF2α/elF2α in PE rats. TMP attenuated the consequences of NO inhibition in pregnant rats.
Effect of weight loss on the estimated glomerular filtration rates of obese patients at risk of chronic kidney disease: the RIGOR‐TMU study
Authors: Lin Yen‐Chung , Lai Yi‐Jen , Lin Yi‐Chun , Peng Chiung‐Chi , Chen Kuan‐Chou , Chuang Ming‐Tsang , Wu Mai‐Szu , Chang Tzu‐Hao 
Published: April 2019

AbstractBackgroundWeight‐reduction therapies, including bariatric surgery (BS), are standard treatments for severely obese patients with type 2 diabetes; however, the outcomes of these therapies are inconclusive for obese patients with chronic kidney disease (CKD). This study aimed to investigate the effects of BS or non‐surgical interventions on the estimated glomerular filtration rate (eGFR) and to determine whether BS can be recommended for renal function preservation based on body mass index (BMI) and eGFR changes in obese patients with CKD.MethodsThis study used data from the weight Reduction Intervention on GFR in Obese Patients with Renal Impairment‐Taipei Medical University (TMU) study, which was a large, long‐term, propensity score‐matched cohort study based on clinical data from patients who registered at weight‐reduction centres at TMU and its affiliated hospitals from 2008 to 2016. The patients were stratified according to whether they had undergone BS and into the mild, moderate, and high CKD risk groups using the Kidney Disease: Improving Global Outcomes guidelines. The primary outcome was the eGFR calculated using the Taiwan Chronic Kidney Disease‐Epidemiology Collaboration equation. Cox regression models were used to determine hazard ratios (HRs) for eGFR decreases ≥25%.ResultsA total of 4332 obese patients were enrolled in this study. After propensity score matching, 1620 patients, including 60.2% women, with a mean age of 36.5 (9.9) years were divided into BS or non‐surgery groups (n = 810 per group). The overall mean eGFRs increased by 4.4 (14) mL/min·1.73 m2 and decreased by 6.4 (16.0) mL/min·1.73 m2 in the BS and non‐surgery groups, respectively. The decrease in BMI in the BS and non‐surgery groups were 2.5 and 1.3 kg/m2, respectively. In the moderate/high CKD risk BS group, a significant correlation was evident between an increased eGFR and a reduced BMI (Spearman's correlation −0.229, P < 0.001). The Cox regression analysis showed that the BS group had a significantly lower risk of an eGFR decline ≥25% at 12 months [adjusted HR (aHR) 0.47, P = 0.03). After BS, obese patients with hypertension or albuminuria had significantly lower risks of eGFR declines ≥25% (aHR 0.37, P = 0.02 and aHR 0.13, P = 0.0018, respectively).ConclusionsBariatric surgery was associated with eGFR preservation in all obese patients and, particularly, in those with moderate‐to‐high CKD risks. A longer term outcome study is warranted to determine the benefits of BS for CKD patients.
Implementation of a new separation method to produce qualitatively improved 64Cu
Authors: van der Meulen Nicholas P. , Hasler Roger , Blanc Alain , Farkas Renata , Benešová Martina , Talip Zeynep , Müller Cristina , Schibli Roger 
Published: April 2019

Background64Cu (T1/2 = 12.7 h) is an important radionuclide for diagnostic purposes and used for positron emission tomography (PET). A previous method utilized at Paul Scherrer Institute (PSI) proved to be unreliable and, while a method using anion exchange chromatography is a popular choice worldwide, it was felt a different approach was required to obtain a robust chemical separation method.MethodsEnriched 64Ni targets were created by electroplating on gold foil. The targets were irradiated with protons degraded to approximately 11 MeV at PSI's Injector 2 72 MeV research cyclotron and subsequently dissolved in HCl. The resultant solution was loaded onto AG MP‐50 cation exchange resin and the 64Cu separated from its target material and radiocobalt impurities, produced as part of the irradiation process, using various specific mixtures of HCl/acetone solution. The eluted product was evaporated and picked up in dilute HCl (0.05 M). The chemical purity of 64Cu was determined by radiolabeling experiments at the highest possible molar activities.ResultsReproducible results were obtained, yielding 3.6 to 8.3 GBq 64Cu of high radionuclidic and radiochemical purity. The product was labeled to NODAGA‐RGD, achieved at up to 500 MBq/nmol, indicating the high chemical purity. In a proof‐of‐concept in vivo study, 64Cu‐NODAGA‐RGD was used for PET imaging of a tumor‐bearing mouse.ConclusionThe chemical separation devised to produce high‐quality 64Cu proved to be robust and reproducible. The concept can be used at medical cyclotrons utilizing a solid target station, such that 64Cu can be used at hospitals for PET imaging.
Infrared and Raman spectra of lignin substructures: Coniferyl alcohol, abietin, and coniferyl aldehyde
Authors: Bock Peter , Gierlinger Notburga 
Published: April 2019

AbstractAnatomical and chemical information can be linked by Raman imaging. Behind every pixel of the image is a Raman spectrum, which contains all the information as a molecular fingerprint. Yet to understand the spectra, the bands have to be assigned to components and their molecular structures. Although the lignin distribution is easily tracked in plant tissues, the assignment of the spectra is not good enough to allow in‐depth analysis of the composition. Assignments of three lignin model compounds were derived from polarization measurements and quantum‐chemical computations. Raman spectra of coniferyl alcohol crystals showed orientation dependence, which helped in band assignment. Abietin showed a Raman spectrum that was very similar to the spectrum of coniferyl alcohol, whereas its IR spectrum was very different due to bands of the sugar moiety. The Raman spectrum of coniferyl aldehyde is affected by the crystal order of molecules. All three compounds show much stronger band intensities than unconjugated single aromatic rings, indicating that the bulk of the lignin structure has significantly reduced contribution to Raman band intensities. Therefore, it is possible to highlight certain structures of lignin with Raman spectroscopy, because low amounts of a compound do not necessarily mean weak features in the spectrum.
Building hot spots in different plasmonic nanoparticles from a cruciform bifunctional dipyridine anthracene
Authors: Imbarack Elizabeth , Sánchez‐González Rodrigo , Soto Juan Pablo , Leyton Patricio , López‐Tocón Isabel , Soto Juan , Sanchez‐Cortes Santiago , Otero Juan Carlos , Campos‐Vallette Marcelo 
Published: April 2019

AbstractIn this work, the adsorption of a type of cruciform system integrated by an anthracene central part and two side chains with a pyridine‐vinyl structure (DPAC) was studied on plasmonic nanoparticles of silver and gold. The adsorption was investigated by surface‐enhanced Raman scattering, which reveals very valuable information about both the interaction mechanism and the molecular orientation. The highest Raman enhancement was measured on Ag nanostars due to the combination of gaps and tips in these nanostructures. The changes observed in the surface‐enhanced Raman scattering spectra indicate that the adsorption of DPAC on the metal is bifunctional in the case of Ag and Au nanoparticles. Considering that the Raman signals enhancement is several orders of magnitude higher in gaps in relation to regions out of these areas, it is estimated that the enhancement ability of DPAC in Ag nanostars is so high that it allows the detection of a concentration close to pM.
Combined microfluidics–confocal Raman microscopy platform for studying enhanced oil recovery mechanisms
Authors: Gao Jun , Nair Sachin , Duits Michel H.G. , Otto Cees , Mugele Frieder 
Published: April 2019

AbstractTo study the mechanism of enhanced oil recovery, it is important to characterize the three‐dimensional spatial distribution of various chemical species, especially water and oil, and their evolution during the course of water flooding. For example, visualizing the (selective) removal of oil from clay or silica substrates by low salinity water can yield important insights. Here, we present a platform that uses a microfluidic device (to represent water flooding at the pore scale) in combination with confocal Raman microscopy. Distributions of oil, water, and minerals are resolved at submicrometer resolution upon flooding water with changing composition. Using glass and gibbsite to mimic sandstone and clay, and water containing divalent cations (Ca2+), we find that oil containing a fatty acid preferentially adsorbs on the gibbsite. Removal of the divalent cations leads to release of the oil droplet. This finding is consistent with the multiple ion exchange mechanism and underlines that the presence of clay is important for low salinity enhanced oil recovery. We expect that our platform will pave the road towards systematic screening of water flood compositions in more complex systems.
Effect of current density on micro‐arc oxidation of Q235 steel and corrosion resistance in liquid Pb‐Bi
Authors: Zhu Qiang , He Ning , Zhang Yanchao , Lei Yucheng 
Published: April 2019

AbstractAn attempt has been made to improve the corrosion resistance in liquid Pb‐Bi by micro‐arc oxidation (MAO), and the effects under different current densities on the corrosion resistance of the coatings were discussed. Scanning electron microscope, energy dispersive spectrometer, and X‐ray diffraction were used to analyze the surface morphology and phase constituents of the MAO coatings produced under different current densities. The corrosion resistance of the coatings was evaluated by studying the element changes and morphology evolution. The results show that the compactness of the ceramic coating decreases with the current density increasing. In contrast to the performance of matrix metal, the ceramic coating exhibited a much better corrosion resistance in liquid Pb‐Bi. Moreover, the ceramic coating produced under current density of 10 A/dm
2 shows the best corrosion resistance.
New surfactants N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides: Preparation and anticorrosion evaluation
Authors: Chen Ziyu , Xiaohui Jiang , Cheng Zhengjun , Liao Yunwen , Pu Qiang , Duan Ming 
Published: April 2019

AbstractA new series of N‐alkyl‐N,N‐dimethyl‐N‐(3‐thienylmethylene)ammonium bromides (designated as NTA‐n, n = 8, 10, 12, 14, and 16) were synthesized. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization showed that NTA‐n could protect availably X70 steel from attack of HCl with an inhibition efficiency of about 95%. And the inhibition ability follows the following sequence: NTA‐8 < NTA‐10 < NTA‐12 < NTA‐14 < NTA‐16, suggesting that prolonging alkyl chain may enhance the inhibition capacity of the molecules. Theoretical investigation backs up well the experiment results. The correlation of theoretical calculation with the experiment results illustrated clearly double logarithmic relations between the corrosion current and the computed quantum chemical parameters such as the highest occupied molecular orbital energy (), energy gap (ΔE), molecular volume (
ν), electronegativity (
χ), the total energy of iron crystal with the adsorbed inhibitor molecule ), the interaction energy of Fe (1 0 0) surface and inhibitor molecules (), while an equation resembling Hammet relation was existed between the corrosion currents and the fraction of electrons transfer (ΔN). These linear correlations suggest the relation of the inhibitor structure with its inhibition activity: long alkyl chain and electron donating groups in NTA‐n will enhance the corrosion efficiency.
Corrosion protection of epoxy coatings containing ZSM‐5 zeolites on Mg–Li alloys
Authors: Wang Yanli , Yan Dashuai , Zhu Yanhao , Liu Jialiang , Song Dalei , Chen Liman , Zhang Tao , Cheng Kui , Zhang Meng , Wang Jun 
Published: April 2019

AbstractThe epoxy composite coatings are developing towards nontoxic and environmentally friendly in the field of corrosion protection. In this study, ZSM‐5 zeolites were chosen as fillers and added to the epoxy coatings on the Mg–Li alloy surface. The effect of ZSM‐5 zeolites on the corrosion properties of epoxy coating was investigated. The results show that the epoxy coating doped with ZSM‐5 zeolites can improve the corrosion protection of the substrate. In particular, the epoxy coating loaded with 0.5% ZSM‐5 zeolites provides enough protection of the alloy against corrosion.
Effect of laser repairing on corrosion behaviour of metal–inert gas welding joint of 7N01 aluminium alloy
Authors: Huang Shuang , Xu Lidong , Chen Hui , Che Xiaoli , Wang Yirong , Yang Xiaoyi 
Published: April 2019

AbstractThe heat affected zone (HAZ) on the metal–inert gas (MIG) welding joint of 7N01 aluminium alloy was repaired by multipass narrow gap laser welding. The Y–X direction precracked three‐point bending sample was used in the alternate immersion test. The morphology of specimen surfaces demonstrated that the exfoliation corrosion in the HAZ after laser repair (HAZa) was more serious than that before laser repair (HAZb). The electrochemical impedance spectroscopy after different immersion corrosion time indicated that the HAZa and HAZb had similar corrosion potentials. However, the pitting corrosion resistance of HAZa was lower than that of HAZb at the beginning of exfoliation corrosion. The stress corrosion crack (SCC) of 7N01P‐T4 aluminium alloy displayed a multicrack source and an intergranular crack propagated along the rolling grain boundary under the test condition. An unusual method was taken to measure the length of SCC. The results showed that laser repairing did not weaken the stress corrosion resistance of the original joint.
Corrosion behavior of porous magnesium coated by plasma electrolytic oxidation in simulated body fluid
Authors: Ghasemi Alireza , Kamrani Sepideh , Hübler Daniela , Fleck Claudia 
Published: April 2019

AbstractPorous magnesium has a great potential to be used as degradable bone scaffolds. In this study, porous magnesium with 35% percolating porosity has been successfully fabricated through powder metallurgy route utilizing space holders. The intrinsic mechanical properties of the porous magnesium were measured by nanoindentation testing and analyzed with the Oliver–Pharr method. Afterward, a ceramic coating on the surface of the porous magnesium was performed by plasma electrolytic oxidation (PEO) treatment in a silicate‐based solution. The morphology and composition results of the PEO coatings indicated that it is possible to apply a homogenous and adhesive ceramic coating layer on all free surface of the porous magnesium through PEO method. The protective performance of the PEO coatings was evaluated using by potentiodynamic polarization and electrochemical impedance spectroscopy tests in simulated body fluid. The results revealed the PEO coating significantly improves biocorrosion resistance of the porous magnesium. Therefore, it can be used as an effective method to control the degradation rate of porous magnesium implants in the human body.
Analysis of Brownian Dynamics and Molecular Dynamics Data of Unentangled Polymer Melts Using Proper Orthogonal Decomposition
Authors: Wong Chi Pui Jeremy , Choi Phillip 
Published: April 2019

AbstractA non‐linear Brownian dynamics (BD) model based upon the Rouse model is developed for unentangled polymer melts. The essence of the model is that it includes an equilibrium spring length b, a non‐linear force term that is not present in the equation of motion of the Rouse model. The equation of motion is solved numerically with the technique of proper orthogonal decomposition (POD) to obtain the dynamics information. To illustrate that the BD model can be readily implemented on polymers with different molecular structures, it is applied to polyethylene with linear, ring, and star structures. For comparison purpose, the corresponding molecular dynamics (MD) simulation is also carried out on molecules with the same sizes (N = 30–73). To characterize the dynamics, time correlation functions of the end‐to‐end vector, the m‐to‐n vector, and the arm vector of the linear, ring, and star polyethylene are determined respectively. It is found that the longest relaxation times (τ1s), the relaxation times of the vectors (τv
s), as well as zero‐shear viscosity (η0s) obtained from the BD and MD simulations agree well with each other. The time correlation functions can be reasonably described using the eigenmodes.
Synthesis of new cyano‐substituted analogues of Tröger's bases from bromo‐derivatives. A stereochemical dependence of long‐range (nJHH, n = 4, 5, and 6) proton–proton and proton–carbon (nJCH, n = 1, 2, 3, 4, and 5) coupling constants of these compounds
Authors: Dusso Diego , Ramirez Cristina , Parise Alejandro , Lanza P. , Vera D. Mariano , Chesta Carlos , Moyano E. Laura , Akhmedov Novruz G. 
Published: April 2019

AbstractA free‐catalyst microwave‐assisted cyanation of brominated Tröger's base derivatives (2a‐f) is reported. The procedure is simple, efficient, and clean affording the nitrile compounds (3a‐e, I) in very good yields. Complete assignment of 1H and 13C chemical shifts of 2a‐f, I and 3a‐d, I was achieved using gradient selected 1D nuclear magnetic resonance (NMR) techniques (1D zTOCSY, PSYCHE, DPFGSE NOE, and DEPT), homonuclear 2D NMR techniques (gCOSY and zTOCSY), and heteronuclear 2D NMR techniques (gHSQCAD/or pure‐shift gHSQCAD, gHMBCAD, bsHSQCNOESY, and gHSQCAD‐TOCSY) with adiabatic pulses. Determination of the long‐range proton–proton coupling constants nJHH (n = 4, 5, 6) was accomplished by simultaneous irradiation of two protons at appropriate power levels. In turn, determined coupling constants were tested by an iterative simulation program by calculating the 1H NMR spectrum and comparing it to the experimental spectrum. The excitation‐sculptured indirect‐detection experiment (EXSIDE) and 1H‐15N CIGARAD‐HMBC (constant time inverse‐detection gradient accordion rescaled heteronuclear multiple bond correlation) were applied for determination of long‐range carbon–proton coupling constants nJCH (n = 2, 3, and 4) and for assignment of 15N chemical shift at natural abundance, respectively. DFT/B3LYP optimization studies were performed in order to determine the geometry of 2c using 6‐31G(d,p), 6‐311G(d,p), and 6–311 + G(d,p) basis sets. For calculation of 1H and 13C chemical shifts, nJHH (n = 2, 3, 4, 5, and 6), and nJCH (n = 1, 2, 3, and 4) coupling constants, the GIAO method was employed at the B3LYP/6‐31G(d,p), B3LYP/6‐31+G(d,p), B3LYP/6‐311+G(d,p), B3LYP/6‐311++G(2d,2p), B3LYP/cc‐pVTZ), and B3LYP/aug‐cc‐pVTZ) levels of theory. For the first time, a stereochemical dependence magnitude of the long‐range nJHH (n = 4, 5, and 6) and nJCH (n = 1, 2, 3, 4, and 5) have been found in bromo‐substituted analogues of Tröger's bases.
Molecular effects on spermatozoa of Mytilus galloprovincialisexposed to hyposaline conditions
Authors: Lettieri Gennaro , Maione Martina , Ranauda Maria Antonietta , Mele Elena , Piscopo Marina 
Published: April 2019

AbstractSalinity represents a critical environmental and an ecological factor in the reproduction of marine species. As global climate changes and anthropogenic factors affect salinity, in this study, we have analyzed the responses of Mytilus galloprovincialis spermatozoa to hyposaline stress. We exposed mussels, in laboratory tanks, for 24 hr at 18°C to control (35.9 psu) and three hyposaline (17.1, 22.6, and 26.2 psu) conditions, and evaluated the expression of sperm hsp70 and protamine‐like proteins genes. Further we analyzed the electrophoretic pattern, the DNA binding and the release from sperm nuclei of protamine‐like proteins. For all experimental approaches used, the results obtained at 17.1 psu condition were very similar to those obtained in the control condition, while alterations were always recorded at 22.6 and 26.2 psu conditions. Particularly, at 22.6 and 26.2 psu, was observed: 42.5‐ and 17.1‐fold increase in hsp70 expression, respectively, and hypoexpression of PL‐II/PLIV protamine‐like proteins genes. Further, electrophoretic mobility shift assays and salt‐induced release of nuclear proteins from sperm nuclei, revealed alterations in the PL proteins/DNA binding, in these two hyposaline conditions. The similarity between the results obtained in control and in the more severe hyposaline condition (17.1 psu) could indicate a phenomenon of fertility preservation strategy due to gamete plasticity.
Parameterization of Models for Vapor Solubility in Semicrystalline Polyethylene
Authors: Savatsky Bruce J. , Moebus Joseph A. , Greenhalgh Brian. R. 
Published: April 2019

AbstractThis paper extends the previous article by the authors on the solubility of hydrocarbon vapors in semicrystalline polyethylenes produced in the gas phase process. That work demonstrates a computational model for solubility based on an activity coefficient modification of the Sako–Wu–Prausnitz equation of state. In that work, by fitting a key parameter, one related to the constraint of tie chains on polymer fluid behavior, to a single isopentane solubility isotherm, accurate predictions of hydrocarbon solubility in polymer granules over a range of temperature, pressure, and composition are reported. In the present work, additional experimental solubility data are reported, an error in the authors' previous article is corrected, and a useful parameterization method that improves the predictive capabilities of the model is demonstrated. By using the model to predict much of the authors' own experimental data, as well as that published by others in the field, it is demonstrated how the proposed parameterization method allows for accurate predictions using a limited amount of experimental measurements.