bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the Levels of Total Aflatoxin in Herbal Traditional Medicines from Selected Vendors Dealers in South-Eastern Nigeria
Authors: Ikeagwulonu Richard C. , Onyenekwe Chinedum C. , Oshim Ifeanyi O. , Olise Nkechi A. , Odeyemi Oluwayemisi , Ojidei Chiedozie K. 
Published: February 2020

Aim: To investigate the levels of total aflatoxin (AF) in herbal medicines from selected vendors in South- Eastern Nigeria.
Study Design: This is a cross-sectional study designed to investigate the levels of aflatoxin (AF) mycotoxin in herbal traditional medicines selected randomly from vendor dealers in Ebonyi State of Nigeria. Fifty-seven (57) herbal medicine samples were obtained from local markets and stores in Ebonyi state, Nigeria.
Place and Duration of Study: This study was carried out at Abakaliki, Ezza-North, Afikpo North, Ohaukwu, Ikwo in Ebonyi State, Nigeria. This study covered a period of one year from April, 2018 to April, 2019.
Methodology: Fifty-seven (57) herbal medicine samples were analyzed to detect the level of aflatoxin (AF) mycotoxins with the controls. They were selected with self-administered questionnaire using a multistage random sampling technique. Wet extraction was performed on the liquid herbal samples whereas aflatoxin occurrence and levels were evaluated using lateral flow immunoassay technique. Data were analyzed using One sample t-test and descriptive statistics and statistical significance was set at P ≤ 0.05.
Results: The incidence of Aflatoxin contamination in the samples were 48(84.21%) out of 57 herbal medicines examined with the highest level seen in African Iba herbal (20.00±2.00 ppb) and the lowest level seen in Dunamis and Divine roots herbals (0.00 ± 0.00). Data from the analysis of herbal medicine samples showed different concentration range of mycotoxins AFs (0-20 ppb).
Conclusion: Although aflatoxins concentration observed in the herbal samples were below Nigerian and European Union (EU) upper limits of 20 ppb, the high incidence rate observed in the study should be of concern to public health. The policy makers in the Nigerian agricultural and health sectors have been provided with research evidence as contained in this study on the dangers posed by consumption of some herbal medicines as a result of their aflatoxin contamination.
Characterization of the cHS4 insulator in mouse embryonic stem cells
Authors: Lu Xi‐bin , Guo Yu‐han , Huang Wei 
Published: February 2020

Synthetic biology circuits are often constructed with multiple gene expression units assembled in close proximity, and they can be used to perform complex functions in embryonic stem cells (ESCs). However, mutual interference between transcriptional units has not been well studied in mouse ESCs. To assess the efficiency of insulators at suppressing promoter interference in mouse ESCs, we used an evaluation scheme in which a tunable tetracycline response element promoter is connected to a constant Nanog promoter. The chicken hypersensitive site 4 (cHS4) insulator, widely used both for enhancer blocking and for barrier insulation in vitro and in vivo, was positioned between the two expression units for assessment. By inserting the cassette into various loci of the mouse ESC genome with PiggyBac transposon, we were able to quantitatively examine the protective effect of cHS4 by gradually increasing the transcriptional activity of the tetracycline response element promoter with doxycycline and then measuring the transcriptional activity of the Nanog promoter. Our results indicate that the cHS4 insulator has minimal insulating effects on promoter interference in mouse ESCs. Further studies show that the cHS4 insulation effect may be promoter specific and related to interaction with CCCTC‐binding factor‐mediated loop formation. In addition, we also compared DNA transposition and transgene expression with or without the cHS4 insulator using well‐established ESC reporters. The results indicate that cHS4 has no apparent effects on DNA transposition and transgene expression levels, but exerts modest protective effects on long‐term transgene silencing.
MoTe2 p–n Homojunctions Defined by Ferroelectric Polarization
Authors: Wu Guangjian , Wang Xudong , Chen Yan , Wu Shuaiqin , Wu Binmin , Jiang Yiyang , Shen Hong , Lin Tie , Liu Qi , Wang Xinran , Zhou Peng , Zhang Shantao , Hu Weida , Meng Xiangjian , Chu Junhao , Wang Jianlu 
Published: February 2020

AbstractDoped p–n junctions are fundamental electrical components in modern electronics and optoelectronics. Due to the development of device miniaturization, the emergence of two‐dimensional (2D) materials may initiate the next technological leap toward the post‐Moore era owing to their unique structures and physical properties. The purpose of fabricating 2D p–n junctions has fueled many carrier‐type modulation methods, such as electrostatic doping, surface modification, and element intercalation. Here, by using the nonvolatile ferroelectric field polarized in the opposite direction, efficient carrier modulation in ambipolar molybdenum telluride (MoTe2) to form a p–n homojunction at the domain wall is demonstrated. The nonvolatile MoTe2 p–n junction can be converted to n–p, n–n, and p–p configurations by external gate voltage pulses. Both rectifier diodes exhibited excellent rectifying characteristics with a current on/off ratio of 5 × 105. As a photodetector/photovoltaic, the device presents responsivity of 5 A W−1, external quantum efficiency of 40%, specific detectivity of 3 × 1012 Jones, fast response time of 30 µs, and power conversion efficiency of 2.5% without any bias or gate voltages. The MoTe2 p–n junction presents an obvious short‐wavelength infrared photoresponse at room temperature, complementing the current infrared photodetectors with the inadequacies of complementary metal‐oxide‐semiconductor incompatibility and cryogenic operation temperature.
Photoredox Catalyst Free, Visible Light‐Promoted C3−H Acylation of Quinoxalin‐2(1H)‐ones in Water
Authors: Lu Juan , He Xiang‐Kui , Cheng Xiao , Zhang Ai‐Jun , Xu Guo‐Yong , Xuan Jun 
Published: February 2020

AbstractA method for the synthesis of 3‐acyl quinoxalin‐2(1H)‐ones through visible‐light promoted decarboxylative acylation of α‐oxo‐carboxylic acids with quinoxalin‐2(1H)‐ones was developed. The reaction was performed in aqueous phase and photoredox catalyst was not required to run the process.magnified image
Efficient Surface Plasmon Polariton Excitation and Control over Outcoupling Mechanisms in Metal–Insulator–Metal Tunneling Junctions
Authors: Makarenko Ksenia S. , Hoang Thanh Xuan , Duffin Thorin J. , Radulescu Andreea , Kalathingal Vijith , Lezec Henri J. , Chu Hong‐Son , Nijhuis Christian A. 
Published: February 2020

AbstractSurface plasmon polaritons (SPPs) are viable candidates for integration into on‐chip nano‐circuitry that allow access to high data bandwidths and low energy consumption. Metal–insulator–metal tunneling junctions (MIM‐TJs) have recently been shown to excite and detect SPPs electrically; however, experimentally measured efficiencies and outcoupling mechanisms are not fully understood. It is shown that the MIM‐TJ cavity SPP mode (MIM‐SPP) can outcouple via three pathways to i) photons via scattering of MIM‐SPP at the MIM–TJ interfaces, ii) SPPs at the metal–dielectric interfaces (bound‐SPPs) by mode coupling through the electrodes, and iii) photons and bound‐SPP modes by mode coupling at the MIM‐TJ edges. It is also shown that, for Al‐AlOx‐Cr‐Au MIM‐TJs on glass, the MIM‐SPP mode outcouples efficiently to bound‐SPPs through either electrode (pathway 2); this outcoupling pathway can be selectively turned on and off by changing the respective electrode thickness. Outcoupling at the MIM‐TJ edges (pathway 3) is efficient and sensitive to the edge topography, whereas most light emission originates from roughness‐induced scattering of the MIM‐SPP mode (pathway 1). Using an arbitrary roughness profile, it is demonstrated that various roughness facets can raise MIM‐SPP outcoupling efficiencies to 0.62%. These results pave the way for understanding the topographical parameters needed to develop CMOS‐compatible plasmonic circuitry elements.
Low‐Thermal‐Budget Doping of 2D Materials in Ambient Air Exemplified by Synthesis of Boron‐Doped Reduced Graphene Oxide
Authors: Cha Jun‐Hwe , Kim Dong‐Ha , Park Cheolmin , Choi Seon‐Jin , Jang Ji‐Soo , Yang Sang Yoon , Kim Il‐Doo , Choi Sung‐Yool 
Published: February 2020

AbstractGraphene oxide (GO) doping and reduction allow for physicochemical property modification to suit practical application needs. Herein, the challenge of simultaneous low‐thermal‐budget heteroatom doping of GO and its reduction in ambient air is addressed through the synthesis of B‐doped reduced GO (B@rGO) by flash irradiation of boric acid loaded onto a GO support with intense pulsed light (IPL). The effects of light power and number of shots on the in‐depth sequential doping and reduction mechanisms are investigated by ex situ X‐ray photoelectron spectroscopy and direct millisecond‐scale temperature measurements (temperature >1600 °C, < 10‐millisecond duration, ramping rate of 5.3 × 105 °C s−1). Single‐flash IPL allows the large‐scale synthesis of substantially doped B@rGO (≈3.60 at% B) to be realized with a thermal budget 106‐fold lower than that of conventional thermal methods, and the prepared material with abundant B active sites is employed for highly sensitive and selective room‐temperature NO2 sensing. Thus, this work showcases the great potential of optical annealing for millisecond‐scale ultrafast reduction and heteroatom doping of GO in ambient air, which allows the tuning of multiple physicochemical GO properties.
Optimized Catalytic WS2–WO3 Heterostructure Design for Accelerated Polysulfide Conversion in Lithium–Sulfur Batteries
Authors: Zhang Bin , Luo Chong , Deng Yaqian , Huang Zhijia , Zhou Guangmin , Lv Wei , He Yan‐Bing , Wan Ying , Kang Feiyu , Yang Quan‐Hong 
Published: February 2020

AbstractThe lithium–sulfur (Li–S) battery is a next generation high energy density battery, but its practical application is hindered by the poor cycling stability derived from the severe shuttling of lithium polysulfides (LiPSs). Catalysis is a promising way to solve this problem, but the rational design of relevant catalysts is still hard to achieve. This paper reports the WS2–WO3 heterostructures prepared by in situ sulfurization of WO3, and by controlling the sulfurization degree, the structure is controlled, which balances the trapping ability (by WO3) and catalytic activity (by WS2) toward LiPSs. As a result, the WS2–WO3 heterostructures effectively accelerate LiPS conversion and improve sulfur utilization. The Li–S battery with 5 wt% WS2–WO3 heterostructures as additives in the cathode shows an excellent rate performance and good cycling stability, revealing a 0.06% capacity decay each cycle over 500 cycles at 0.5 C. By building an interlayer with such heterostructure‐added graphenes, the battery with a high sulfur loading of 5 mg cm−2 still shows a high capacity retention of 86.1% after 300 cycles at 0.5 C. This work provides a rational way to prepare the metal oxide–sulfide heterostructures with an optimized structure to enhance the performance of Li–S batteries.
Integrated effects of nitrogen form, row spacing, and herbicide treatment on maize
Authors: Simić Milena , Dragičević Vesna , Babić Milosav , Brankov Milan , Filipović Milomir 
Published: February 2020

AbstractTo control weeds and cultivate maize (Zea mays L.) with higher yields, production systems have to include more efficient forms of N and appropriate herbicide treatments. The timing of N release could give maize an advantage over weeds in competition for resources, whereas cultivation at lower row spacing often decreases weed biomass. Knowledge about the different factors affecting herbicide efficiency increases the accuracy and reliability of chemical control. This study tested the weed infestation level and the development and productivity of a recently developed maize hybrid grown with the application of several integrated practices. The maize hybrid was sown with application of standard and slow‐releasing urea, with row spacing of 50 and 70 cm and treatment with either a pre‐emergence or a post‐emergence mix of herbicides. The numbers of plants of each weed species and their biomass were lower after the application of herbicides, although N form and row spacing produced no significant differences in the average weed infestation level for 3 yr. The post‐emergence herbicide treatment was more effective than the pre‐emergence treatment for weed biomass reduction and enhancing maize yield parameters. The N form did not influence any measured yield parameter, whereas the 70‐cm row spacing resulted in significantly higher harvest index and grain yield (0.45 and 9.19 Mg ha−1, respectively) than the 50‐cm spacing (0.43 and 7.36 Mg ha−1, respectively). The wider row spacing resulted in higher grain yield through its interaction with N form and herbicide treatment.
Herbage responses of Tamani and Quênia guineagrasses to grazing intensity
Authors: Tesk Cátia R. M. , Cavalli Josiana , Pina Douglas S. , Pereira Dalton H. , Pedreira Carlos G. S. , Jank Liana , Sollenberger Lynn E. , Pedreira Bruno C. 
Published: February 2020

AbstractNew forage cultivars require defoliation studies for recommending proper grazing management. Our objective was to characterize herbage accumulation (HA), plant‐part composition and nutritive value of guineagrass [Megathyrsus maximus (Jacq.) B. K. Simon & S. W. L. Jacobs] rotationally stocked under two grazing intensities. The experimental design was a randomized complete block with three replicates of a 2 × 2 factorial arrangement of two guineagrass cultivars (‘BRS Quênia’ and ‘BRS Tamani’) and two grazing intensities. Heavy (HGI) and lax (LGI) grazing intensities were imposed as post‐grazing stubble heights: 15 and 25 cm for Tamani, and 20 and 35 cm for Quênia, respectively. The experimental period was from March 2015 to March 2017, comprising eight seasons (autumn 2015, winter 2015, spring 2015, summer 2016, autumn 2016, winter 2015, spring 2016, and summer 2017). In the spring 2016 and summer 2017, pre‐grazing HM was sampled as two strata above the stubble height, each comprising 50% of the sampled height (upper and lower stratum). Total herbage accumulation was similar across years, cultivars, and intensities (16,810 kg DM ha−1). Quênia and Tamani had the greatest HA during summer. The leaf proportion was least in the HGI pastures. Under HGI, the lower stratum of both cultivars had the greatest stem proportion and the least nutritive value. The greatest herbage CP concentration and the least NDF, ADF, iNDF and LIG concentrations occurred in the upper stratum. Based on these results, 35 and 55 cm are recommended as target heights for initiation of grazing, and 25 and 35 cm as post‐grazing stubble heights for Tamani and Quênia, respectively.
On the prediction of gas hold‐up in two‐phase flow systems using an Euler–Euler model
Authors: Mowla Amir , Agnaou Mehrez , Treeratanaphitak Tanyakarn , Budman Hector M. , Abukhdeir Nasser M. , Ioannidis Marios A. 
Published: February 2020

AbstractWe quantify the ability of the two‐fluid Euler–Euler model to predict the overall gas hold‐up during two‐phase flow in vertical columns using a combination of experiments and simulations. Gas hold‐up in a bubble column and gas hold‐up in the less‐frequently studied co‐current flow are investigated. For homogeneous flow characterized by nearly uniform bubble size, Euler–Euler model predictions are within 10% of the experimental values for both modes of operation, if the bubble diameter supplied as input to the model is the average bubble diameter in the physical system. This also holds true for heterogeneous flow in bubble columns despite the presence of a broad distribution of bubble sizes, if turbulence and bubble swarm effects on momentum exchange between phases are properly accounted for. Swarm corrections adequate for bubble columns, are less successful for co‐current heterogeneous flow, for which gas hold‐up predictions are least accurate (average error of 22%).
When the going gets tough, the tough turn female: injury and sex expression in a sex‐changing tree
Authors: Blake‐Mahmud Jennifer , Struwe Lena 
Published: February 2020

PremisePlant sex is usually fixed, but in rare cases, sex expression is flexible and may be influenced by environmental factors. Theory links female sex expression to better health, but manipulative work involving the experimental change of health via injury is limited, particularly in sexually plastic species. A better understanding of mechanisms influencing shifts in sex is essential to our understanding of life history theory regarding trade‐offs in sex allocation and differential mortality.MethodsWe investigated the relationship between physiological stress and sex expression in sexually plastic striped maple trees (Acer pensylvanicum) by inflicting damage of various intensities (crown pruning, defoliation, and hydraulic restriction). We then monitored the sex expression of injured and control individuals for 2 years to assess the extent to which injury may cue changes in sex expression.ResultsWe found that severe damage such as full defoliation or severe pruning increased odds of changing sex to female and decreased odds of changing to male. In fact, no pruned male trees flowered male 2 years later, while all males in the control group flowered partially or fully male. After full defoliation, trees had 4.5 times higher odds of flowering female. Not all injury is equal; less‐severe physical trauma did not affect the frequency of sex change to femaleness.ConclusionsThis work demonstrates that physical trauma in striped maple appears to exhibit a threshold effect in which only the most stressful of physiological cues instigate changes in sex expression, a phenomenon previously unknown, and that damage stress is strongly correlated with switching to femaleness. These findings have implications for population sex ratios and sustainability within an increasing stressful climate regime.
Pollinator visitation rate and effectiveness vary with flowering phenology
Authors: Gallagher M. Kate , Campbell Diane R. 
Published: February 2020

PremiseFlowering time may influence pollination success and seed set through a variety of mechanisms, including seasonal changes in total pollinator visitation or the composition and effectiveness of pollinator visitors.MethodsWe investigated mechanisms by which changes in flowering phenology influence pollination and reproductive success of Mertensia ciliata (Boraginaceae). We manipulated flowering onset of potted plants and assessed the frequency and composition of pollinator visitors, as well as seed set. We tested whether floral visitors differed in their effectiveness as pollinators by measuring pollen receipt and seed set resulting from single visits to virgin flowers.ResultsDespite a five‐fold decrease in pollinator visitation over four weeks, we detected no significant difference in seed set among plants blooming at different times. On a per‐visit basis, each bumblebee transferred more conspecific pollen than did a solitary bee or a fly. The proportion of visits by bumblebees increased over the season, countering the decrease in visitation rate so that flowering time had little net effect on seed set.ConclusionsThis work illustrates the need to consider pollinator effectiveness, along with changes in pollinator visitation and species composition to understand the mechanisms by which phenology affects levels of pollination.
Treatment and disease‐related complications in multiple myeloma: Implications for survivorship
Authors: Chakraborty Rajshekhar , Majhail Navneet S. 
Published: February 2020

AbstractNew treatments have transformed multiple myeloma into a chronic disease. Hence, optimal management of treatment and disease‐related complications remains a critical component of survivorship care. Survivorship care model in cancers requiring a fixed‐duration therapy may not be applicable to myeloma, since patients are exposed to multiple lines of continuous therapy along the disease trajectory. The two most common therapy‐related causes of death, which require special consideration, are infection and second cancers. Identifying patients at a high risk of toxicities will facilitate individualized treatment selection and designing clinical trials for protective strategies targeting those patients. For example, prophylactic antibiotic or immunoglobulin replacement can be tested for primary prevention of infections in high‐risk patients. Long‐term follow up of ongoing trials and epidemiologic data will help identify the nature and trajectory of rare toxicities with a long latency, such as secondary cancers. Patients who are frail, have persistent renal insufficiency, and refractory to multiple lines of therapy need special attention regarding treatment toxicity and quality of life. In this review, we discuss the incidence, risk‐factors, and management of treatment and disease‐related complications in myeloma, discuss knowledge gaps and research priorities in this area, and propose a survivorship care model to improve health‐care delivery to a growing pool of myeloma survivors.
In vitro safety of ketotifen as a topical nasal rinse
Authors: Triantafillou Vasiliki , Maina Ivy W. , Patel Neil N. , Tong Charles C. L. , Papagiannopoulos Peter , Kohanski Michael A. , Kennedy David W. , Palmer James N. , Adappa Nithin D. , Cohen Noam A. , Bosso John V. 
Published: February 2020

BackgroundKetotifen is a second‐generation noncompetitive H1‐antihistamine and mast‐cell stabilizer. It is commonly used to treat or prevent allergic conjunctivitis, asthma, chronic urticaria, anaphylaxis, mast‐cell, and other allergic‐type disorders. However, it has never been studied in aspirin‐exacerbated respiratory disease (AERD), an aggressive phenotype of chronic rhinosinusitis with nasal polyps, where the mast cell plays a prominent role its pathogenesis.MethodsHuman sinonasal epithelial cells were grown at an air‐liquid interface (ALI). Ketotifen powder was dissolved in saline to make 4 test solutions at 1.04, 2.08, 10.4, and 20.8 µg/mL. Control (saline) or ketotifen solution was added apically to ALI cultures from tissue of 5 unique patients, and ciliary beat frequency (CBF) changes were recorded. Lactate dehydrogenase was measured at 24 and 48 hours to estimate long‐term cellular toxicity.ResultsApical application of ketotifen at all concentrations was neither ciliotoxic nor ciliostimulatory, with no change in CBF over a period of 15 minutes after application. Cellular toxicity for all concentrations at 24 and 48 hours after application was <3% and <7%, respectively, that of lysed cultures.ConclusionTopical application of ketotifen to an in vitro model of sinonasal epithelium is safe, as evaluated by CBF and lactate dehydrogenase. Ketotifen is neither ciliotoxic nor ciliostimulatory, and no long‐term cellular toxicity was observed. Ketotifen may have promise as a topical nasal rinse in the treatment of AERD.