bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent‐Free Mechanochemical Preparation of Hierarchically Porous Carbon for Supercapacitor and Oxygen Reduction Reaction
Authors: Qi Jiawei , Zhang Wendu , Xu Lang 
Published: October 2018

AbstractHierarchically porous carbon (HPC) derived from fallen flowers was prepared by a green method of combining solvent‐free ball milling with the safe activating agent potassium bicarbonate. By regulating the mass ratio of KHCO3 to biochar, the as‐prepared HPC materials possess high specific surface areas of up to 2147.9 m2 g−1 and abundant hierarchical pores comprised of micro‐, meso‐, and macropores. The specific capacitances of the HPC materials are able to reach 302.7 F g−1 at a current density of 0.5 A g−1 in 6 m KOH, and the symmetric supercapacitor composed of two identical HPC electrodes shows good stability because 100 % of the specific capacitance is retained after 5000 charge/discharge cycles and 90.5 % of the specific capacitance remains after 12 000 cycles. Nitrogen self‐doped HPC materials also show higher electrocatalytic activity and stronger methanol tolerance for the oxygen reduction reaction than that of the commercial Pt/C catalyst. This preparation method can be extended to the green conversion of other varieties of biomass waste into useful carbon materials.
Recovery of Cu(II) from nickel laterite leach using prereduction and chelating resin extraction: Batch and continuous experiments
Authors: Botelho Junior Amilton B. , Jiménez Correa Mónica M. , Espinosa Denise C. R. , Dreisinger David , Tenório Jorge A. S. 
Published: October 2018

AbstractThe processing of laterite ores for nickel and cobalt production is increasing to meet the global demand for these metals. Sulphuric acid is used as a leaching agent, and metals present in the solution may be recovered by many different processes, such as ion exchange. The main problem with nickel limonite layer leach solution is the high concentration of iron, which decreases the efficiency of resin adsorption of nickel and cobalt. The removal of iron by oxidation and precipitation results in nickel, copper, and cobalt losses (co‐precipitation). The aim of this work was to investigate the chelating resin extraction to recover copper from a leachate combined with a pre‐reduction process, in order to increase the resin's efficiency and to increase its pH above 2.00. The following three synthetic solutions were studied: first, a solution prepared with Fe(III); the second solution was prepared with Fe(II); and the last solution was prepared with Fe(III) using a reducing process. Batch experiments were performed to study the influence of pH and temperature, and column experiments with three solutions were compared in order to verify suitable conditions to recover Cu(II) in a fixed‐bed column process.
Contrasting characteristics of daily physical activity in older adults by cancer history
Authors: Wanigatunga Amal A. , Gresham Gillian K. , Kuo Pei‐Lun , Martinez‐Amezcua Pablo , Zipunnikov Vadim , Dy Sydney M. , Simonsick Eleanor M. , Ferrucci Luigi , Schrack Jennifer A. 
Published: October 2018

BackgroundUsing objectively collected physical activity (PA) data from the Baltimore Longitudinal Study of Aging, the authors tested whether patterns of daily activity and sedentary time differed by cancer survivorship in older adults.MethodsIn total, 659 participants (mean age ± standard deviation, 71 ± 10 years; 51% women) who had self‐reported information on cancer history were instructed to wear an accelerometer for 7 consecutive days. Accelerometer data were summarized into: 1) PA volume and 2) activity fragmentation (interrupted activity), expressed as both continuous and as dichotomized (low and high) variables. Participants were categorized into 4 groups by cross‐classification of dichotomous PA volume and fragmentation. Multiple regression models were used to estimate differences in PA patterns by cancer history.ResultsCancer survivors averaged 0.12 fewer log‐transformed activity counts per day (standard error, 0.05; P = .02) than individuals who reported no history of cancer after adjusting for demographics, behavioral factors, and comorbidities. Although fragmentation did not differ by cancer survivorship in the continuous model (P = .13), cancer survivorship was associated with 77% greater odds (odds ratio, 1.77; 95% confidence interval, 1.11‐2.82) of having high (vs low) fragmentation and 94% greater odds (odds ratio, 1.94; 95% confidence interval, 1.13‐3.33) of having combined low PA/high fragmentation (vs high PA/low fragmentation) relative to those with no cancer history.ConclusionsThe current findings suggest that cancer survivors engage in lower total daily PA and that they perform this activity in a more fragmented manner compared with adults without a history of cancer. These results may reflect the onset and progression of a low‐activity phenotype that is more vulnerable to heightened levels of fatigue and functional decline with aging.
Virus‐Based Nanomotors for Cargo Delivery
Authors: Tejeda‐Rodríguez José A. , Núñez Alfredo , Soto Fernando , García‐Gradilla Víctor , Cadena‐Nava Rubén , Wang Joseph , Vazquez‐Duhalt Rafael 
Published: October 2018

AbstractSelf‐propelled nanomotors based on virus structure were designed, fabricated and characterized. Capsids from plant virus were covered on one hemisphere with platinum layer to promote motion in the presence of hydrogen peroxide. The Janus viral nanomotors (JVNs) with 25–30 nm diameter from brome mosaic virus (BMV) and cowpea chlorotic mottle virus (CCMV) showed motion speeds of up to 9 μm/sec, depending of the peroxide fuel concentration in the medium. The JVNs can carry and deliver the chemo‐therapeutic drug Tamoxifen, and they are able to internalize into breast tumor cells without any functionalization. The therapeutic payload is released by a pH‐driven delivery action of the nanomotor. Here, the first proof of concept of a self‐propelled virus‐like nanoparticle is demonstrated. The attractive capabilities of nanomotors based on virus‐like nanoparticles (VLPs) pave the way to diverse biomedical applications.
Conformational Dynamics in the Core of Human Y145Stop Prion Protein Amyloid Probed by Relaxation Dispersion NMR
Authors: Shannon Matthew D. , Theint Theint , Mukhopadhyay Dwaipayan , Surewicz Krystyna , Surewicz Witold K. , Marion Dominique , Schanda Paul , Jaroniec Christopher P. 
Published: October 2018

AbstractMicrosecond to millisecond timescale backbone dynamics of the amyloid core residues in Y145Stop human prion protein (PrP) fibrils were investigated by using 15N rotating frame (R1ρ) relaxation dispersion solid‐state nuclear magnetic resonance spectroscopy over a wide range of spin‐lock fields. Numerical simulations enabled the experimental relaxation dispersion profiles for most of the fibril core residues to be modelled by using a two‐state exchange process with a common exchange rate of 1000 s−1, corresponding to protein backbone motion on the timescale of 1 ms, and an excited‐state population of 2 %. We also found that the relaxation dispersion profiles for several amino acids positioned near the edges of the most structured regions of the amyloid core were better modelled by assuming somewhat higher excited‐state populations (∼5–15 %) and faster exchange rate constants, corresponding to protein backbone motions on the timescale of ∼100–300 μs. The slow backbone dynamics of the core residues were evaluated in the context of the structural model of human Y145Stop PrP amyloid.
A design of waveguide elliptic filter based on resonant diaphragms with a complex aperture
Authors: Zemlyakov Viacheslav , Krutiev Sergey , Tyaglov Mikhail , Shevchenko Valery 
Published: October 2018

SummaryA novel approach to the synthesis of waveguide band‐pass elliptic filters on the transverse metal resonant diaphragms with the complex aperture is proposed. The aperture of the diaphragm is considered to be a rectangular window with two L‐shaped metal ridges. For the complex conductivity of the diaphragm, we solve the corresponding electrodynamic problem. We also construct and investigate an equivalent circuit of the resonant diaphragm containing a series‐parallel LC circuit. The geometry of the diaphragm aperture is found to be corresponding to the parameters of the equivalent circuit. We construct a third‐order elliptic filter and provide a computer simulation of the diaphragms satisfying the amplitude‐frequency characteristics of its resonators. We show that some resonators can be located on one complex resonant diaphragm, which then reduces the length of the filter. The band‐pass filter for a rectangular waveguide WR137 is developed and manufactured. The central frequency of the filter is 6.6 GHz, the passband width 7.5 % with return loss of −20 dB, and the total length is 34 mm.
A comparative study of the pyrolysis and combustion characteristics of sodium‐rich Zhundong coal in slow and rapid processes
Authors: Huang Zhong , Li Na , Zhou Qulan , Wang Duanyang , Yin Huaqiang 
Published: October 2018

AbstractCoal with high content of alkali metal has limited use in the combustion process. The slow and rapid pyrolysis and combustion characteristics of sodium‐rich Zhundong coal were investigated using a thermal gravimetric analyzer and one‐dimensional drop‐tube furnace. The results show that the process was complete when the final temperature exceeds 900°C in slow pyrolysis, while in rapid pyrolysis it lasts for short residence time in the whole furnace. The weight loss ratio in rapid pyrolysis was significantly higher than that in slow pyrolysis, and shows different trends at different reaction temperatures. There is an extremum value of weight loss ratio obtained at 800°C in rapid pyrolysis, which is accompanied by the maximum value for the diameter of pores and the minimum value for specific surface area. Most alkali elements are released from the solid product, and the amounts of released alkali elements in combustion are higher than that in pyrolysis process. The apparent activation energy in the two pyrolysis processes and release of alkali in combustion were evaluated using different models, which demonstrates that the alkali release trend in combustion is easier than that of pyrolysis.
Evaluation of different pretreatments of Napier grass for enzymatic saccharification and ethanol production
Authors: Tsai Ming‐Hsun , Lee Wen‐Chien , Kuan Wei‐Chih , Sirisansaneeyakul Sarote , Savarajara (Akaracharanya) Ancharida 
Published: October 2018

AbstractDue to its fast‐growing and high carbohydrate content, Napier grass has a great potential to be chosen as a raw material for renewable energy production. The Napier grass after different pretreatments was tested for simultaneous saccharification and fermentation (SSF) with dried yeast (Saccharomyces cerevisiae) and cellulase (CTec2) to produce ethanol. For alkaline pretreatment, the grass was incubated with 10% NaOH at a ratio of 1:20 (w/v) at 90°C for 1 hour. For dilute acid pretreatment, the grass was soaked with 1% H2SO4 at a ratio of 1:10 (w/v) and incubated at 120°C for 1 hour. For the two‐stage pretreatment, the resultant solid from dilute acid pretreatment was further treated with 2% NaOH (1:10 w/v) at 80°C for 6 hours. After enzymatic saccharification at 50°C and pH 5.0 for 96 hours using CTec2, yields of glucose from three pretreated Napier grass samples (10% water‐insoluble solids, WIS) were 75.4 ± 2.9%, 55.4 ± 6.5%, and 76.4 ± 5.0%. Using 10% WIS of alkaline‐pretreated Napier grass biomass as the substrate, the 72‐hour SSF led to an ethanol yield of 86.6 ± 3.4%. On the basis of the dried biomass of Napier grass as the raw material, the ethanol yield could reach 0.143 ± 0.006 (g/g). Napier grass biomass could be effectively treated by alkaline, dilute acid, or two‐stage pretreatment methods to remove non‐cellulosic components to some extent. Alkaline pretreatment was found to be superior to dilute acid and two‐stage pretreatment methods, based on ethanol yields obtained under similar SSF conditions.
A numerical simulation of a dry‐out process for CO2 sequestration in heterogeneous deep saline aquifers
Authors: Ren Jie , Wang Yuan , Zhang Yingqi 
Published: October 2018

AbstractSalt precipitation can be generated near the injection well when dry supercritical CO2 (scCO2) is injected into deep saline aquifers. Traditional laboratory experiments and numerical simulations focus on the generation of salt precipitation and its impact on core permeability. Recent laboratory experimental studies have shown that the heterogeneity of the core and water content on the surface of the particles plays an important role in the formation of salt precipitation. The goal of this study is to investigate the effects of brine back‐flow, heterogeneity, and low water content on salt precipitation. Numerical simulations were performed using core‐scale and site‐scale models. Simulation results showed the following: 1. Back‐flow plays an important role in the salt accumulation near the well – an homogeneous laboratory experiment used with a small core may not provide a full picture of the back‐flow phenomenon. 2. The continuous dry‐out process reduces the water content near the injection well to zero. As a result, the full range of saturation flow equations should be used to simulate the dry‐out process accurately. 3. The heterogeneity of the matrix not only affects the distribution of salt precipitation but also increases the amount of salt precipitation near the well. Homogeneous simulation underestimates the amount of salt precipitation. 4. The reduction in porosity due to salt precipitation could extend the dry‐out process in the low permeability zone, further expanding the salt precipitation area. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
Geochronology and geochemistry of Early Silurian felsic volcanic rocks in the Dabaoshan ore district, South China: Implications for the petrogenesis and geodynamic setting
Authors: Su Shiqiang , Qin Kezhang , Li Guangming , Pang Xuyong , Zou Xinyu , Zhao Chao 
Published: October 2018

The Early Paleozoic orogeny in South China has remained controversial in the long run with debate over intracontinental orogeny versus plate subduction. Limited studies have focused on the Early Paleozoic volcanic rocks in South China, which is crucial for us to understand the tectonic evolution of the South China Block. The Dabaoshan Fe–Cu–Pb–Zn–Mo–W orefield, one of the largest polymetallic deposits in South China, is hosted by Paleozoic volcanic‐sedimentary rocks and Mesozoic granitic porphyry. In this study, zircon U–Pb dating yielded ages of 439.4 ± 2.7 Ma, 439.3 ± 3.2 Ma, and 442.0 ± 2.2 Ma for the Dabaoshan dacite. These ages are all in good agreement within errors and indicate that the dacite formed during the early Silurian (ca. 440 Ma). The dacites are slightly peraluminous, calc‐alkaline with relatively high K2O + Na2O, FeOt, TiO2, CaO/Na2O ratios, and small negative Eu anomalies. They show enrichment in LILEs and LREE and depletion in Ba, Nb, Sr, P, and Ti. It has high initial87Sr/86Sr values (0.70983–0.71140) and negative εNd(t) values ranging from −7.6 to −10 with T2DMages of 1.80–1.99 Ga, εHf(t) values from −4.95 to −15.48 with T2DMages of 1.72 Ga to 2.38 Ga. The overlapped Nd–Hf two‐stage model ages range from 1.89 Ga to 1.99 Ga, which indicates that the Dabaoshan dacite originated from a Paleoproterozoic source. Combining these geochemical and in situ zircon Hf isotopic data, we propose that the Dabaoshan dacite may have originated from the partial melting of mixed source of Paleoproterozoic metasedimentary and metaigneous rocks as a result of underplating of mafic magma during the post‐orogenic collapse and extension followed by lithospheric thining and asthenospheric mantle upwelling in an intraplate setting. Based on field observation and the geochronology results, we propose that the stratiform Cu–Pb–Zn mineralization may be related with the early Silurian volcanic rocks.
Energy balance and snowmelt drivers of a marginal subalpine snowpack
Authors: Bilish Shane P. , McGowan Hamish A. , Callow John Nikolaus 
Published: October 2018

AbstractSnowmelt from the seasonal snowpack in the Australian Alps is a significant source of water for irrigated agriculture, electricity generation, and environmental flows in the Murray–Darling Basin. Previous studies have reported negative decadal to multidecadal trends in maximum snow depth, snow season duration, and snow‐covered area. Here, we characterise the energy balance of this marginal maritime snowpack for the first time. Turbulent fluxes measured using the eddy covariance and bulk aerodynamic methods are compared; discrepancies are attributed to the differing assumptions of the methods and characteristics of the measurement site. We examine the variability of the individual energy balance components and the drivers of snowmelt, and we find that incoming longwave radiation is the dominant control on snowmelt, providing more than 80% of the total energy to the snowpack over the season. During a midwinter rain‐on‐snow event, the advected rain heat flux provided 8% of the daily total, with the incoming longwave flux still accounting for almost 80%. The ground heat flux contributes a small proportion of the seasonal total but increases in patchy or intermittent snow cover. Comparing these results with those of studies in other maritime locations, we find that the turbulent fluxes are likely to make a proportionally higher contribution to the energy balance due to the short Australian snow season, underpinning the sensitivity of this environment to climate variability and change. These results extend the limited body of knowledge on highly marginal snowpacks and may be relevant to other regions with no direct measurements of the energy balance.
Coordination‐Driven Self‐Assembly of Functionalized Supramolecular Metallacycles: Highlighted Research during 2010–2018
Authors: Hu Yi‐Xiong , Zhang Xiangyi , Xu Lin , Yang Hai‐Bo 
Published: October 2018

AbstractDuring the past few decades, the construction of macrocyclic molecules/complexes has attracted considerable attention because of their wide applications in sensing, catalysis, molecular machine, drug delivery, etc. Coordination‐driven self‐assembly has proven to be a simple yet highly efficient approach for the preparation of various supramolecular metallacycles with the predetermined shapes and sizes as well as the distribution and total number of functional groups. Since the significant progress has been made during the last few years in the field of coordination‐driven self‐assembly, it is time to summarize the recent development in coordination‐driven self‐assembly of functionalized supramolecular metallacycles. In this review, we will highlight some recent advances concerning the preparation of functionalized supramolecular metallacycles via coordination‐driven self‐assembly between the year 2010–2018. In addition, the properties and the applications of these metallacycles in the areas of photo‐ and electrochemistry, sensing, supramolecular gel, biological applications, etc. will be also discussed.
The imbalance of Th17/Treg axis involved in the pathogenesis of preeclampsia
Authors: Eghbal‐Fard Shadi , Yousefi Mehdi , Heydarlou Hanieh , Ahmadi Majid , Taghavi Simin , Movasaghpour Aliakbar , Jadidi‐Niaragh Farhad , Yousefi Bahman , Dolati Sanam , Hojjat‐Farsangi Mohammad , Rikhtegar Reza , Nouri Mohammad , Aghebati‐Maleki Leili 
Published: October 2018

AbstractProblemInappropriate activation of the immune system, particularly the imbalance of T‐helper type 17 (Th17)/regulatory T (Treg) cells is thought to play considerable roles in preeclampsia (PE). To investigate the probable effects of the adaptive immune system in the pathophysiology of PE, we analyzed the dynamic changes of Th17/Treg cells, cytokines profile, and transcription pattern of Th17/Treg‐related genes and microRNAs (miRNAs) in 50 women suffering from PE in comparison with 50 healthy pregnant women.MethodsExpressions of cytokines, specific transcription factors, and related miRNAs were measured by real‐time polymerase chain reaction (PCR). Enzyme‐linked immunosorbent assay (ELISA) was used to test the interleukin (IL)‐17, IL‐23, IL‐6, and IL‐10 and transforming growth factor β in serum and supernatant of peripheral blood mononuclear cells (PBMCs). The frequency of Th17 and Treg cells were determined by flow cytometry.ResultsPE patients exhibited a decreased number of Treg cells (p = 0.006), while Th17 cells were increased (
p = 0.004). Forkhead box P3 and
IL‐10 mRNA expressions were reduced (
p = 0.0001 and 0.0028, respectively), while expressions of retinoic acid receptor‐related orphan nuclear receptor γt, IL‐17, IL‐23, and IL‐6 were enhanced (
p < 0.0001, 0.0018, 0.0014, and 0.027, respectively). ELISA results also showed increased levels of IL‐6, IL‐17, and IL‐23 (
p = 0.022, 0.0005, 0.0081, respectively), and decreased levels of IL‐10 in the supernatant of PBMCs of PE patients compared with control group (
p = 0.0011). There was significant upregulation of miR‐106b and miR‐326 (
p = 0.0048 and 0.028, respectively) in PE patients in comparison with the control group.ConclusionsThese findings suggest that imbalance of Th17/Treg cells, regulated possibly via microRNAs, may be involved in the pathogenesis of PE, emphasizing on the importance of these cells in feto‐maternal immune cross‐talk.
Histopathological impairment of common carp (Cyprinus carpio) induced through povidone‐iodine exposure
Authors: Hedayati Aliakbar , Darabitabar Fateme , Bagheri Toktam , Hedayati ElaheSadat , Van Doan Hien 
Published: October 2018

AbstractHistological biomarkers are one of the most advantageous tools in monitoring toxicological studies under experimental condition in laboratory. Since disinfectants are extensively inflowing into aquatic ecosystems, this study conducted on common carp to examine the effect of betadine solution on the liver and gill tissue. A 120‐carp were kept for 2 weeks in the 100‐l aquarium Different concentrations of povidone‐iodine (betadine) prepared in three replications and a control group was prepared with no betadine (0, 5, 7, 8, and 9 ppm). Most lesions observed at gill tissue include adhesion secondary lamella, bleeding, destruction of secondary lamellae, hyperplasia secondary blades, curvature second blade, destroying the primary lamellae. Whats more, most lesions observed in liver tissue include bleeding, ascites liver, destruction of liver cells, bile stagnation. Betadine solution, could cause damage to the liver and gills tissues, although gill lesions were more evident than liver. Also increase of concentration led to elevation at lesions of both organs. Overally, the results revealed that using povidon‐iodine as a disinfectant materials and entering into rivers and aquatic ecosystems could have undesirable effects and even death of this fish. Disinfectants, either in low or high concentration, could be very lethal for fish. However the defects seen in this study also could affect osmoregulation and metabolism as two main functions of gill and liver.