bluuebunny/crossref_metadata_2025 huggingface dataset:
Ectomycorrhizal fungal communities associated with Larix gemelinii Rupr. in the Great Khingan Mountains, China
Authors: Wang Yonglong , Zhao Yanling , Xu Ying , Ma Jianjun , Babalola Busayo Joshua , Fan Yongjun
Published: April 2021

Larix gemelinii is an important tree species in the Great Khingan Mountains in Northeast China with a high economic and ecological value for its role in carbon sequestration and as a source of lumber and nuts. However, the ectomycorrhizal (EM) fungal diversity and community composition of this tree remain largely undefined. We examined EM fungal communities associated with L. gemelinii from three sites in the Great Khingan Mountains using Illumina Miseq to sequence the rDNA ITS2 region and evaluated the impact of spatial, soil, and climatic variables on the EM fungal community. A total of 122 EM fungal operational taxonomic units (OTUs) were identified from 21 pooled-root samples, and the dominant EM fungal lineages were /tricholoma, /tomentella-thelephora, /suillus-rhizopogon, and /piloderma. A high proportion of unique EM fungal OTUs were present; some abundant OTUs largely restricted to specific sites. EM fungal richness and community assembly were significantly correlated with spatial distance and climatic and soil variables, with mean annual temperature being the most important predictor for fungal richness and geographic distance as the largest determinant for community turnover. Our findings indicate that L. gemelinii has a rich and distinctive EM fungal community contributing to our understanding of the montane EM fungal community structure from the perspective of a single host plant that has not been previously reported.
Factors Affecting Capillary Suction Time of Sludge Using Wet Front Distance and Filtrate Flow Rate Methods
Authors: Onoh C. , Ademiluyi J. O. , Amah V. E.
Published: April 2021

Sludge generated during wastewater treatment is difficult to handle due to their high water content, hence a need for dewatering. The factors that affect the outcome of capillary suction time (CST) were studied using piggery and domestic sludge samples conditioned with ferric chloride. Effects of conditioner concentration, hydrostatic pressure and mixing time were investigated. Filtrate flow rate studies were also carried out as an alternative to wet front progression to determine CST. Ferric chloride was varied from 0.002 to 0.008 g/ml, hydrostatic height was varied from 20 to 40 mm while mixing time ranged from 0 to 120 sec. The optimum conditioner concentration was observed to be 0.0055 and 0.0035 g/ml for piggery sludge and domestic sludge respectively. At 5 % level of significance, hydrostatic height was observed to have no significant effect on the CST for the range of hydrostatic heights chosen. The optimum mixing time observed for 90 g/l and 30 g/l piggery sludge was 50 and 25 sec respectively. While the optimum mixing time for 28 g/l and 14 g/l domestic sludge was 10 and 5 sec respectively. Flow rate was discovered to have an inverse relationship with CST, with the optimum conditioner concentration corresponding to the peak flow rate and minimum CST for both test samples. Hence, in other to eliminate the difficulty presented by the anisotropic property of the capillary suction apparatus (CSA) filter paper, filtrate flow method can be used instead of wet front progression method.
A Review on Reservoirs Sedimenation Problems in Ethiopia
Authors: Adugna Tesfaw Melkamu , Cherie Dessie Almaw
Published: April 2021

Environmental impacts and long-term morphological changes on the natural water course and mainly through soil erosion (water erosion) due to human intervention, the reservoirs handled by sedimentation. Soil erosion and sedimentation are natural phenomena involved in landscape formation. Cumulative sediment yield is influenced by the combination of factors including soil erodability, soil textural class, organic matter content, watershed area, topography and vegetation cover. In Ethiopia, accelerated sedimentation in reservoirs providing hydroelectric power and irrigation water has resulted in loss of these intended services. The frequent power-cuts and rationing-based electric power distribution recently experienced in the country are also partially attributed to the loss of storage capacity of hydroelectric power reservoirs. Sediment derived from soil erosion and delivered to rivers is a major source of various environmental problems such as sediment deposition in river channels and reservoirs which deteriorates water quality. Sedimentation is a critical pollutant in surface waters that adversely affect water quality and contains other important contaminants including nutrients, pesticides and heavy metals. Some minerals transported with sediments like Cu, Pb, As and Hg are extremely toxic even in small concentration and affect quality of water in dams for various purposes. The suspended solids in the eroded material increases the raw water turbidity (i.e., water becomes muddy and physically dirty),which increases water treatment costs.
Analysis of Consumer Behavior in Freshwater Fish Purchase Decisions (A Case Study at the Sabilulungan Modern Fish Market, Bandung Regency, West Java, Indonesia)
Authors: Putri Vany Aulia , Rizal Achmad , Apriliani Izza Mahdiana , Gumilar Iwang
Published: April 2021

This study aims to analyze the behavior of freshwater fish consumers in the Sabilulungan Modern Fish Market, Bandung Regency and to analyze the factors that encourage consumers to buy freshwater fish at PIM Sabilulungan. The method used in this research is a case study with research subjects, namely freshwater fish consumers at PIM Sabilulungan, using a rating scale analysis and rank spearman. The sampling technique used was accindental random sampling with a total of 40 respondents. The consumer purchasing decision process consists of five stages, namely the introduction of needs, information search, evaluation of alternatives, the purchase process and evaluation of post-purchase results. The results showed that at the introduction stage the need for motivation to purchase freshwater fish because fish have good nutrition, at the information search stage the source of information obtained by respondents was print / electronic media. In the alternative evaluation stage, the reason consumers buy freshwater fish at PIM Sabilulungan is because of the various types of fish. At the purchasing stage, respondents buy 1.1kg-3kg freshwater fish with a frequency of buying it twice a month. In the post-purchase evaluation stage, respondents are satisfied with the freshwater fish products being sold and the marketed prices are affordable. To see the factors that influence purchase motivation, the rank spearman test is used. The test results show that the product price and service quality are the factors that most influence the purchase decision of freshwater fish at the Sabilulungan Modern Fish Market with t count values ​​of 16.245 and 16.228.
Residual Effect of Cow Dung Fertilizer to Corn (Zea mays L.) Growth and Yield in Planting Period II in Marginal Land
Authors: Hasid Rachmawati , Bahrun Andi , Arma Makmur Jaya
Published: April 2021

Aims: The research aimed to study the potential of cow dung fertilizer residue in increasing the growth and yield of corn plant in planting period II on marginal dry land.

Study Design: Singel factor design in Randomized block design.

Place and Duration of Study: The research was conducted in Field Laboratory of the Faculty of Animal Husbandry, University of Halu Oleo, Kendari, Southeast Sulawesi, Indonesia. The study was conducted for four months.

Methodology: Single factor design in Randomized block design was used in the research. consists of 6 treatment levels of cow manure residue that have been applied in the previous planting period (planting period I), namely: without cow manure (R0), using cow manure 2.5 t ha-1 (R1), 5 t ha-1 (R2), 7.5 t ha-1 (R3), 10 t ha-1 (R4) and 12.5 t ha-1 (R5). Each treatment was placed in three groups so that there were 18 experimental units. The data was analyzed using analysis of variance and continued by Duncan’s Multiple Range Test (DMRT) 95% confidence level.

Results: The results showed that the vegetative growth of corn plant 30 day after planting (dap) and plant yield  was affected by residual effect  of cow dung that applicated in the planting periode I, thus with P uptake by plant and available P in planting medium. 

Conclusion: Plant productivity during planting period II more increased with the higher dose of cow manure applied during planting period I. The highest plant productivity (3.88 t ha-1) in planting period II was obtained by application of cow dung 12.5 t ha-1 during planting period I. While in the planting medium without cow dung, no seeds formation was found in plants.
Philately’s Implications in Ecological Education via Romanian Thematic Joint Issues (VI) - Regarding the 4th Collaboration with WWF
Authors: Cioruța Bogdan-Vasile , Pop Alexandru Leonard
Published: April 2021

The last philatelic issue made by the Romanian postal administration in collaboration with WWF, published at the end of 2006, is the main subject of this study. As we have become accustomed to, WWF's interests in conserving endangered species are becoming better defined. This time the emphasis is on protecting birds, and among these, we are talking about the Eurasian spoonbill. The species itself is representative of the habitat of the Danube Delta, where it was also immortalized, and where the inspiration for the layout of the philatelic pieces came from. Moreover, through the rich philatelic material identified, analyzed, and presented, one can discuss the other philatelic effects. All these, through the beauty of the exhibition and the contribution brought among the collectors, philatelists, and implicitly of those who love nature, make the issue a successful one. The purpose of this study is to complete, by presenting the philatelic issue from 2006, the series of Romanian philatelic issues dedicated to the protection of various species. In this regard, besides the well-defined role in promoting protected species, was also discussed a little about the role of philately in educating the young generation, informing tourists, as well as in documenting habitat conservation policies and strategies.
Contribution to the Study of Phosphorus Adsorption Kinetics on the Superficial Sediments of a Recently Development Artificial Estuary: Vridi Channel (Côte d'Ivoire)
Authors: Samuel N’da , Konan Yao Marcel , Albert Trokourey
Published: April 2021

The aim of this study is to characterize phosphates adsorption kinetics on the superficial sediments of Vridi channel from its new hydromorphology. So, three scenarios have been carried out taking account the different waters seasons of this estuary by using pH and temperature as relevant parameters. In the first scenario, the experiments carried out at pH = 8 and T = 20°C to simulate phosphates adsorption on these sediments in its great cold season. In the second, the experiments carried out at pH = 8 and T = 25° C to simulate phosphates adsorption on these substrates in its hot season and small cold season. In the third, the experiments carried out at pH = 7 and T = 30°C to simulate phosphates adsorption on these sediments in its flood season. The experiences were carried out according to US EPA/530/SW-87/006-F protocol. KH2PO4 solutions were used as phosphates synthetic solutions. The experimental data were modeling by Lagergeen kinetics model (pseudo-order 1), Blanchard kinetics model (pseudo-order 2), Elovich kinetics model, Weber and Morris kinetics model and, external diffusion kinetics model. The results have showed phosphates adsorption on these sediments increase in the experiments carried out at pH = 8 and T = 20°C to those carried out at pH = 7 and T = 30°C. All experimental data have been well modeling by Blanchard kinetics model. So, these phosphates adsorption kinetics are pseudo-order 2 and the chemisorption is the dominant mechanism. The results obtained by the experimental data modeling by Weber and Morris kinetics model and external diffusion kinetics model showed that this process is not limiting by the molecular diffusion process. The experimental data have been again well modeling by Elovich kinetics model. That has confirmed the chemisorption character of this adsorption, and showed this chemisorption is activated.
Evaluation of Pollution Load: Heavy Metal Contents and Physiochemical Properties of the Great Kwa River, Calabar, Cross River State, Nigeria
Authors: Ekpo Paul Bassey , Umoyen Anthony John , Akpan Nseobong Godwin , Ekpo Inyang Paul , Abu Gabriel , Sunday Cecilia James
Published: April 2021

Background and Objectives: Human activities can increase the amount of pollutants in the environment leading to water pollution. The contamination of surface water and sediments by heavy metals can result in adverse health conditions of humans, due to the bioaccumulation of metals. This study seeks to assess the pollution load of some heavy metals and physiochemical properties in Great Kwa River.

Methods: Water samples were collected once a month from three stations within four selected months in wet and dry seasons. Samples were preserved by adding 10 ml of 6 N Nitric acid and stored at 5oC. Laboratory investigations were conducted and data analyzed statistically.

Findings: The mean pH, dissolved O2, biological O2 demand, conductivity, NO3, NH4 and temperature were 7.44±1.24, 5.58±0.92, 0.957±0.002, 32.84±2.941, 0.1030±0.1701, 0.113±0.018 and 28.2±1.48, respectively during wet season. Mean concentration of Cu, Fe, Cr, Mn, Zn, Ni are 0.225±0.003, 0.489±0.009, 0.068±0.016, 0.102±0.006, 0.794±0.003, 0.031±0.001, respectively during the wet season. Mean concentration of metals in the river during the wet season were ranked in descending order as Zn > Fe > Cu > Mn > Cr > Ni. Iron (0.489±0.009 mg/l and 0.438±0.003 mg/l), chromium (0.068±0.016 mg/l and 0.055±0.008 mg/l), nickel (0.031±0.001 mg/l and 0.025±0.002 mg/l) were higher than Nigerian standard for drinking water in both seasons. The contamination factor of heavy metals in station 3 were 2.14, 1.56, 1.09, 0.89 for Fe, Cr, Ni, Zn, respectively, indicating moderate contamination. The pollution load index in stations 1, 2, 3 were 0.262, 0.537, 0.981, respectively.

Conclusion: The present study provided base-line information on the pollution levels and physiochemical properties of the river. The river was not highly polluted by heavy metals except iron, chromium and nickel that were found above the recommended standards. However, drinking of water from the river over one’s lifetime is not advisable due to detrimental health hazards.
Effect of Plant Population on Yield of Selected Maize (Zea mays L.) Varieties in Mwea and Bura in Kenya
Authors: Aleri Daudi Dindi , Kinama Josiah M. , Chemining’wa George N.
Published: April 2021

The objective of the study was to determine the effect of plant population on the growth and yield of maize. The study was conducted during the short rainy season of December 2018 and April 2019 in Mwea, Kirinyaga County and Bura, Tana River County, in Kenya. An experiment was set in a split-split plot design with three replications. Five selected maize (Zea mays) varieties commonly grown in these areas namely: Pioneer, DH04, Sungura, SC Duma and DH02 were grown under three plant population densities namely: 53,333, 66,666 and 88,888 plants ha-1 under irrigated conditions. Cob length, ear height, plant height, above ground biomass and grain yield data was collected. Plant population had significant effects on the grain yield and yield components of the selected maize varieties. The plant population of 53,333 plants ha-1 gave significantly higher above ground biomass in Mwea than population of 88,888 plants ha-1, though not significantly different from population of 66,666 plants ha-1. In Bura, the plant population of 88,888 plants ha-1 gave significantly higher above ground biomass than that of 66,666 and 53,333 plants ha-1 respectively. An increase in plant population reduced the grain yield of the selected maize varieties but increased the above ground biomass of the varieties.
Efficiency and Response to Phosphorus Use of Corn Cultivars in the Tropical Climate
Authors: Santos Weder Ferreira dos , Maciel Lucas Carneiro , Junior Osvaldo José Ferreira , Rocha Gabriel Mesquita da , Peluzio Joênes Mucci , Sodré Layanni Ferreira , Faria Lucas Alves de , Barbosa Adriano Silveira , Silva Diogo Claudio da
Published: April 2021

Aims: The present study evaluated the efficiency and response to phosphorus (P) use of corn cultivars in the tropical climate in southern Para State, Brazil.

Study Design: Two experiments were carried out, in low P (50 kg ha-1) and high P (200 kg ha-1) applications in Randomized block design (RBD), three replicates, and fourteen cultivars were used for the experiment.

Place and Duration of Study: The experiment was carried out in the 2019-20 harvest at Sitio Vitoria (8º18'32" S, 50º36'58" W), located in the municipality of Santa Maria das Barreiras, a southern region of Para state, Brazil.

Methodology: Phosphate fertilization was used in the sowing groove. In low P, 50 kg ha-1 of P2O5 were applied, and in high P were 200 kg ha-1 of P2O5. The source was simple superphosphate (18% P2O5). The dose in high P was defined to achieve high yields and considering the nutrient content in the soil, in low P the dose was well below. Nitrogen and potassium fertilization in cover were divided: 50% in V4 and 50% in V8. Doses of 150 kg ha-1 of N and 90 kg ha-1 of K2O were used, and fertilizers were used: urea (43% N) and potassium chloride (60% K2O).

Results: The highest means were: 8,710 kg ha-1 efficiency and 29.78 kg kg-1 response. The efficient cultivars were: ORION, BR 2022, CR 120, AL BANDEIRANTE, M 274, BRS 3046, and AG 8088. And those considered responsive were: BM 3061, BR206, CATIVERDE 02, BR 205, ANHEMBI, BR 2022, and BRS 3046.

Conclusion: The cultivar BR 2022 and BRS3046 showed high efficiency and also a response to phosphorus use.
Assessment of Levels and Ecological Risks of Some Selected Potentially Toxic Metals in Soils around Onne Dumpsite, Rivers State, Nigeria
Authors: Audu P. , Oyet G. I. , Chibor B. S.
Published: April 2021

The concentrations of selected potentially toxic metals and other soil physico-chemical variables in soil receptacles of a solid waste dumpsite at Onne, Nigeria were assessed to ascertain the levels of contamination and ecological risks. Surface soils (0 – 20 cm depth) from four sampling areas (north, south, east and west) of the dumpsite were analyzed for Cd, Pb, Ni, As and Cr, using atomic absorption spectroscopy. Single and integrated ecological risks indices were calculated using established models. Results revealed the mean values (mg/kg) of Cd (1.00 – 3.09), Pb (125.37 – 285.48), Ni (10.37 – 16.17), As (0.26 – 0.87), Cr (52.16 – 77.17). Assessment of ecological risk indices for north, south, east and west showed {PLI (2.38, 1.27, 1.17 and 1.33), EF (1.01, 16.0, 13.90 and 56.0), Cd (21.50, 11.10, 9.49 and 10.90), PERI (392.0, 132.0, 148.0  and 157.0), PIAvg (5.17, 2.55, 2.27 and 2.56), PINemerow (7.75, 3.80, 3.18 and 3.38) } respectively. These implied that the soils around the dumpsite area were polluted due to enrichment of the selected metals and therefore of low quality. Ecological risk reduction strategies were also recommended.
The Efficacy of the Absorbable Polydioxanone (PDO) Thread Lift in Lower Face (Marionette Line) Rejuvenation
Authors: Gerges Marian W. , Hassan Ghada F. R. , Mostafa Walid A. , Maadawy Iman H. El-
Published: April 2021

Aims: To evaluate the efficacy of PDO thread lifting in lower face (marionette line) rejuvenation.

Study Design:  Quasi experimental study.

Place and Duration of Study: Dermatology and Venereology Department, Tanta University Hospital, between January 2018 and April 2019.

Methodology: The study included 10 patients asking for lower face rejuvenation who were treated by PDO absorbable threads (2 threads in each side of marionette line).

Results: The mean validated grading scale for marionette line score before treatment was of 3.30 ± 0.82 while the mean score immediately after treatment was 1.70 ± 0.82. There was statistically significant improvement according to validated grading scale of marionette line after compared to before. These results were preserved after 1, 3 and 6months.

Conclusion: PDO threads is a simple, rapid, immediately effective and office technique procedure.
Effect of Vernonia Amygdalina Leaf on Cytochrome P450 2D6- and 3A4-Mediated Metabolism of Dextromethorphan in Healthy Nigerian Subjects
Authors: Oladepo Mariam Olaide , Adegbola Adebanjo Jonathan , Soyinka Julius Olugbenga , Onyeji Cyprian Ogbona
Published: April 2021

Back-ground and Objectives: The study’s focus is to investigate the effects of Vernonia amygdalina on the metabolic activities of Cytochrome P450 3A4 and 2D6 in vivo. The assessment was based on CYP2D6-mediated O-demethylation and CYP3A4-mediated N-demethylation of dextromethorphan (DEX) to Dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively.

Methods: The clinical study followed a two-phase cross over study with two weeks washout period. Volunteers received a single oral dose of DEX 30 mg alone in phase 1 and along with last dose of V. amygdalina leaf powder in phase 2. 8-hour urine samples were collected in both phases post-administration of DEX and analyzed using HPLC-UV. The chromatographic separation of DEX, DOR, 3-MM, and Imatinib was achieved on a C18 column. The analytes were eluted with a gradient elution consisting of 50mM potassium dihydrogen phosphate (pH 5)-acetonitrile at a 1 mL/min flow rate, and detected at 280 nm. Activities of the enzymes investigated were evaluated using the urinary metabolic ratios of DEX:DOR and DEX:3-MM.

Results: Median (interquartile range) values for the metabolic ratios of DEX:DOR was 0.032 (0.028-0.246) and 0.029 (0.018-0.061) for phases with and without V. amygdalina respectively, while the average median values for DEX:3MM was 5.087 (3.692-71.420) and 5.609 (3.093-19.197) for phases with and without V. amygdalina respectively. However, the differences between both phases were not significant for both isoenzymes.

Conclusion: V. amygdalina does not significantly affect the activities of CYP2D6 and CYP3A4 In vivo, which indicates that it has minimal potential to interact with the substrates of both isoenzymes.
Phytochemical Screening, Antioxidant Activity and Inhibitory Potential of Five Kenyan Medicinal Plants
Authors: Wafula Mukhwana Dennis , Cyrus Ayieko , Collins Mweresa , Johnstone Ingonga , Damaris Matoke-Muhia
Published: April 2021

The present study was conducted to evaluate preliminary phytochemical analysis and in vitro antioxidant activities of five plants (Olea europaea, Kigelia africana, Terminalia mollis, Croton macrostachyus and Bridella micrantha extracts). The plants were collected from Baringo County in Kenya, dried, pulverized into fine powders and extracted using methanol. Phytochemical analysis showed the presence of alkaloids, aminoacids and proteins, flavonoids, saponins, steroids, tannins and triterpenoids. The root extracts were further investigated for their potential antioxidant activity by using radical scavenging DPPH (2, 2-Diphenyl-2-picryl-hydrazyl) technique. Methanol extract of roots from the plants showed significant differences in DPPH radical scavenging activities. The results were concluded that extracts have a more secondary metabolites and potential source of antioxidants, which is warranty to evaluate further in vivo pharmacological studies.
Liquid Based Cytology versus Conventional Cytology for Evaluation of Cervical PAP Smear
Authors: Chandwani Vishakha , Saraswathi K. , Rao G. Bheema , Sivastava Vindu
Published: April 2021

The cervix is the narrow inferior segment of the uterus which projects into the vaginal vault.  Conventional cervical cytology is a simple, cost effective method that has been in use for more than 50 years and is still a highly effective cervical cancer screening procedure. Liquid-based, thin-layer preparation of cervical cytology specimens was a subsequent modification in technique. The present study was split-sample study was to compare Thin Prep Liquid-based Cytology with Conventional Pap Smear, relying on a laboratory with long term experience of the former. In our study most of the Conventional preparations showed cell overlapping, inflammatory cells, blood and mucus that obscure the epithelial cell  morphology  which  was much reduced in Liquid based preparations.
Hybrid‐triggered fault detection filter design for networked Takagi–Sugeno fuzzy systems subject to persistent heavy noise disturbance
Authors: Qi Ji , Li Yanhui
Published: April 2021

In the network environment, the single time‐triggered scheme wastes limited bandwidth resources due to all the sampled data are transmitted to the networks, and the single event‐triggered scheme may increase system error because of ignoring factors such as changes in network utilization. To reduce the design conservatism, this paper is concerned with the hybrid‐triggered L1 fault detection filter design for a class of nonlinear networked control systems (NCSs) described by Takagi–Sugeno (T‐S) fuzzy model. Taking the effects of time‐triggered scheme and event‐triggered scheme into consideration simultaneously, we construct a fuzzy fault detection system. New results on stability and L1 performance are proposed for fuzzy fault detection system by exploiting the Lyapunov–Krasovskii functional and by means of the integral inequality method. Specially, attention is focused on the design of fault detection filter that guarantees a prescribed L1 noise attenuation level . Finally, two examples are presented to demonstrate the effectiveness of the proposed method.
New Silk Road: From Mesoscopic Reconstruction/Functionalization to Flexible Meso‐Electronics/Photonics Based on Cocoon Silk Materials
Authors: Shi Chenyang , Hu Fan , Wu Ronghui , Xu Zijie , Shao Guangwei , Yu Rui , Liu Xiang Yang
Published: April 2021

Two of the key questions to be addressed are whether and how one can turn cocoon silk into fascinating materials with different electronic and optical functions so as to fabricate the flexible devices. In this review, a comprehensive overview of the unique strategy of mesoscopic functionalization starting from silk fibroin (SF) materials to the fabrication of various meso flexible SF devices is presented. Notably, SF materials with novel and enhanced properties can be achieved by mesoscopically reconstructing the hierarchical structures of SF materials. This is based on rerouting the refolding process of SF molecules by meso‐nucleation templating. As‐acquired functionalized SF materials can be applied to fabricate bio‐compatible/degradable flexible/implantable meso‐optical/electronic devices of various types. Consequently, functionalized SF can be fabricated into optical elements, that is, nonlinear photonic and fluorescent components, and make it possible to construct silk meso‐electronics with high‐performance. These advances enable the applications of SF‐material based devices in the areas of physical and biochemical sensing, meso‐memristors, transistors, brain electrodes, and energy generation/storage, applicable to on‐skin long‐term monitoring of human physiological conditions, and in‐body sensing, information processing, and storage.
Direct Growth of Hexagonal Boron Nitride Thick Films on Dielectric Substrates by Ion Beam Assisted Deposition for Deep‐UV Photodetectors
Authors: Li Dongdong , Gao Wei , Sun Xiaoyan , Yu Haiying , Liu Caiyun , Yin Hong
Published: April 2021

High quality hexagonal boron nitride (h‐BN) thick films are indispensable for practical deep‐ultraviolet (DUV) photodetector applications. However, the controllable synthesis of h‐BN films in terms of thickness and crystallinity often requires high growth temperatures, tedious chemical precursors and, catalytic transition metal substrates, that will eventually hinder their applicability. In this work, the direct growth of h‐BN films with thickness of 50–500 nm on silicon(100), sapphire, and quartz substrates by ion beam assisted deposition at a lower temperature (≈500 °C) without employing extra catalysis is reported. The as‐synthesized h‐BN thick films are stoichiometric, smooth, and continuous without obvious pinholes and cracks, consisting of nanocrystalline domains on the dielectric substrates, distinct from those grown on metallic substrates. More intriguingly, the DUV photodetector fabricated from a 500 nm thick h‐BN film on quartz substrate exhibits high peak responsivity (0.5 A W−1) with a ultrahigh on/off ratio of >103 at 204 nm, a high rejection ratio (R204nm/R250nm > 103), a large specific detectivity (6.92 × 109 Jones), and a sharp cutoff wavelength at 218 nm. The work herein demonstrates the great potential of this form of h‐BN thick films toward the development of DUV photodetectors.
Isolating the Electrocatalytic Activity of a Confined NiFe Motif within Zirconium Phosphate
Authors: Sanchez Joel , Stevens Michaela Burke , Young Alexandra R. , Gallo Alessandro , Zhao Meng , Liu Yunzhi , Ramos‐Garcés Mario V. , Ben‐Naim Micha , Colón Jorge L. , Sinclair Robert , King Laurie A. , Bajdich Michal , Jaramillo Thomas F.
Published: April 2021

Unique classes of active‐site motifs are needed for improved electrocatalysis. Herein, the activity of a new catalyst motif is engineered and isolated for the oxygen evolution reaction (OER) created by nickel–iron transition metal electrocatalysts confined within a layered zirconium phosphate matrix. It is found that with optimal intercalation, confined NiFe catalysts have an order of magnitude improved mass activity compared to more conventional surface‐adsorbed systems in 0.1 m KOH. Interestingly, the confined environments within the layered structure also stabilize Fe‐rich compositions (90%) with exceptional mass activity compared to known Fe‐rich OER catalysts. Through controls and by grafting inert molecules to the outer surface, it is evidenced that the intercalated Ni/Fe species stay within the interlayer during catalysis and serve as the active site. After determining a possible structure (wycherproofite), density functional theory is shown to correlate with the observed experimental compositional trends. It is further demonstrated that the improved activity of this motif is correlated to the Fe and water content/composition within the confined space. This work highlights the catalytic enhancement possibilities available through zirconium phosphate and isolates the activity from the intercalated species versus surface/edge ones, thus opening new avenues to develop and understand catalysts within unique nanoscale chemical environments.
Micro/Nano‐Scaled Metal‐Organic Frameworks and Their Derivatives for Energy Applications
Authors: Wei Yong‐Sheng , Zou Lianli , Wang Hao‐Fan , Wang Yu , Xu Qiang
Published: April 2021

Metal‐organic frameworks (MOFs), as a distinctive class of crystalline porous materials, are constructed by organic linkers and metal ions/clusters. By virtue of their high surface area, structural diversity, and functional adjustability, MOFs and their derivatives, especially with tunable morphologies and sizes, have been well exploited for versatile applications, becoming a rapidly developing interdisciplinary research area. This review focusses on the design and synthesis of 1D, 2D, and 3D MOF nanostructures and their derivatives at micro/nanoscale, with promising catalytic applications including electrocatalysis and photocatalysis, as well as, energy storage like batteries and supercapacitors. The results are discussed and the critical insights gained from the works in this review are summarized, and the challenges and future prospects for this emerging field are outlined.
Conjugated Microporous Polymers with Bipolar and Double Redox‐Active Centers for High‐Performance Dual‐Ion, Organic Symmetric Battery
Authors: Wang Heng‐guo , Li Qiang , Wu Qiong , Si Zhenjun , Lv Xiaoling , Liang Xitong , Wang Huilin , Sun Lin , Shi Weidong , Song Shuyan
Published: April 2021

Redox‐active conjugated microporous polymers (RCMPs) have received remarkable interest in electrochemical energy‐storage systems in view of their porous structure and tunable redox nature. This work presents an effective strategy to construct RCMPs with bipolar and double redox‐active centers by integrating copper (II) tetraaminephthalocyanine (CuTAPc) and 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTCDA) units into the RCMPs (CuPcNA‐CMP). As expected, CuPcNA‐CMP has potential application in the half cells of dual‐ion batteries (lithium based DIBs, LDIBs), asymmetric DIBs (graphite based DIBs, ADIBs), and symmetric DIBs (all organic DIBs, SDIBs). Among them, LDIBs show a high reversible capacity (202.4 mAh g−1 at 0.2 A g−1) and excellent rate capability (86.1 mAh g−1 at 5 A g−1). And ADIBs also show a high reversible capacity (245.3 mAh g−1 at 0.1 A g−1), long cycle stability with capacity retention of 89% after 500 cycles, and good rate performance (125.1 mAh g−1 at 5 A g−1). In addition, SDIBs show high initial charge/discharge capacities of 269.4/198.5 mAh g−1 at 0.05 A g−1 and a high cell voltage of 2.5 V. Meanwhile, the mechanism of CuPcNA‐CMP on hosting both anions (PF6−) and cations (Li+) is investigated by detailed experimental analysis and density functional theory studies.
Nutrient excretion from cattle grazing nitrogen‐fertilized grass or grass–legume pastures
Authors: Garcia Liza , Dubeux José C. B. , Sollenberger Lynn E. , Vendramini Joao M. B. , DiLorenzo Nicolas , Santos Erick R. S. , Jaramillo David M. , Ruiz‐Moreno Martin
Published: April 2021

Nutrient cycling via livestock excreta is an important grassland ecosystem service. This study was conducted in 2016 and 2017 and determined nutrient excretion from cattle grazing three systems: (a) N‐fertilized bahiagrass (Paspalum notatum Flüggé) overseeded with rye (Secale cereale L.) and oat (Avena sativa L.) during winter (Grass+N), (b) unfertilized bahiagrass overseeded with rye–oat–clover (Trifolium sp.) mixture (Grass+clover), and (c) rhizoma peanut (Arachis glabrata Benth.)–bahiagrass mixture overseeded with a rye–oat–clover mixture (Grass+CL+RP). Urinary volume excreted in the warm season ranged from 122 to 182 L ha−1d−1, more than double that in the cool season (56–70 L ha−1 d−1). Urinary N concentration during the warm season was greater in Grass+CL+RP compared with Grass+N (4.4 vs. 3.1 g kg−1, respectively). In addition, fecal dry matter and organic matter output was greater for Grass+N than for steers grazing Grass+CL+RP during the warm season (3.8 and 3.2 vs. 2.8 and 2.2 kg hd−1 d−1, respectively). Total annual feces excretion concentrations of P, K, Mg, and N were greater in the Grass+N than in Grass+CL+RP system. The introduction of legumes increased the proportion of N returning via urine. However, when summed across seasons, total N excretion (feces and urine) was greater in Grass+N than in Grass+CL+RP (89 vs. 71 kg ha−1 yr−1), mainly due to the greater stocking rate in the former. Grass–legume systems receiving 34 kg N ha−1 yr−1 recycled 80% of the N recycled in the grass system receiving 224 kg N ha−1 yr−1, indicating the potential of forage legumes to add N to grasslands.
Rhodium‐Catalyzed Synthesis of Isoquinolino[1,2‐b]Quinazolines via C−H Annulation in Biomass‐Derived γ‐Valerolactone
Authors: Wang Liang , Jiang Kuan‐chang , Zhang Nana , Zhang Zhi‐hui
Published: April 2021

A rhodium‐catalyzed synthesis of isoquinolino[1,2‐b]quinazolines via C−H annulation using vinylene carbonate as an oxidizing acetylene surrogate in biomass‐derived γ‐valerolactone (GVL) has been developed. The reactions proceeded smoothly to give the corresponding products in moderate to good yields without any external oxidant and base. This protocol can also be applied for the synthesis of 5,6‐dihydro‐8H‐isoquinolino[1,2‐b]quinazolin‐8‐ones.
The association of osteochemometrics and bone mineral density in humans
Authors: Pedrosa Mariana , Ferreira Maria Teresa , E. Batista de Carvalho Luís A. , M. Marques Maria Paula , Curate Francisco
Published: April 2021

Objectives

Even though much is known about bone mineral and matrix composition, studies about their relationship with several bone properties and its alterations related to bone diseases such as osteoporosis are practically non‐existent in humans. Thus, the development of methods to understand the effects of bone properties at a microscopic level is paramount. This research aimed to evaluate whether Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) band intensity ratios correlate with femoral bone mass, bone mineral content (BMC) (total and femoral neck), bone mineral per unit area (BMD) (total, femoral neck, greater trochanter, intertrochanteric region, and Ward's area) and the area (total and femoral neck). A sample of femora from the 21st Century Identified Skeleton Collection (N = 78, 42 females and 36 males) was employed and BMC, BMD, and the femoral areas were acquired by DXA.

Results

It was found that only females' BMD had a significant association with the femoral FTIR‐ATR indices under study, whereas bone collagen (Am/P) and the content of carbonate Type A (API) in males correlated with the total proximal femur area of the regions of interest and the femoral neck area.

Discussion

Men and women showed different changes related to their chemical composition in BMD, BMC, and probed area, most likely due to differences in structure and physiology, as well as mechanical strength in the proximal femoral sites where BMD was analyzed.
Heterogeneous frailty and the expression of linear enamel hypoplasia in a genealogical population
Authors: Lawrence Julie , Stojanowski Christopher M. , Paul Kathleen S. , Seidel Andrew C. , Guatelli‐Steinberg Debbie
Published: April 2021

Objectives

Linear enamel hypoplasia (LEH) is a common skeletal marker of physiological stress (e.g., malnutrition or illness) that is studied within and across populations, without reference to familial risk. We examine LEH prevalence in a population with known genealogical relationships to determine the potential influence of genetic heritability and shared environment.

Methods

LEH data of 239 individuals from a single population were recorded from the Ohio State University Menegaz‐Bock collection dental casts. All individuals were of known age, sex, and genealogy. Narrow‐sense heritability estimates were obtained for LEH presence and count data from all unworn, fully erupted teeth (excluding third molars) using SOLAR (v.8.1.1). Age, sex, and age–sex interaction were included as covariates. Models were re‐run with a household effect variable.

Results

LEH persists across generations in this study population with moderate, significant heritability estimates for presence in four teeth, and count in four teeth (three teeth were significant for both). When a household effect variable was added, no residual heritability remained for LEH count on any tooth. There was no significant household effect for three of the four teeth that had significant heritability estimates for LEH presence. Age was a significant covariate. Further analyses with birth year data revealed a secular trend toward less LEH.

Conclusions

This study provides evidence for familial risk of LEH (genetic and environmental) that has consequences for the broad use of this skeletal marker of stress. These results have repercussions for archaeological assemblages, or population health studies, where genetic relatives and household groups might be heavily represented.
A Two‐Pronged Pulmonary Gene Delivery Strategy: A Surface‐Modified Fullerene Nanoparticle and a Hypotonic Vehicle
Authors: Chen Daiqin , Liu Shuai , Chen Dinghao , Liu Jinhao , Wu Jerry , Wang Han , Su Yun , Kwak Gijung , Zuo Xinyuan , Rao Divya , Cui Honggang , Shu Chunying , Suk Jung Soo
Published: April 2021

Inhaled gene therapy poses a unique potential of curing chronic lung diseases, which are currently managed primarily by symptomatic treatments. However, it has been challenging to achieve therapeutically relevant gene transfer efficacy in the lung due to the presence of numerous biological delivery barriers. Here, we introduce a simple approach that overcomes both extracellular and cellular barriers to enhance gene transfer efficacy in the lung in vivo. We endowed tetra(piperazino)fullerene epoxide (TPFE)‐based nanoparticles with non‐adhesive surface polyethylene glycol (PEG) coatings, thereby enabling the nanoparticles to cross the airway mucus gel layer and avoid phagocytic uptake by alveolar macrophages. In parallel, we utilized a hypotonic vehicle to facilitate endocytic uptake of the PEGylated nanoparticles by lung parenchymal cells via the osmotically driven regulatory volume decrease (RVD) mechanism. We demonstrate that this two‐pronged delivery strategy provides safe, wide‐spread and high‐level transgene expression in the lungs of both healthy mice and mice with chronic lung diseases characterized by reinforced delivery barriers.
Enhanced dispersion of hydroxyapatite whisker in orthopedics 3D printing resin with improved mechanical performance
Authors: Chong Yi Ting , Tan Clara S. H. , Liu Li Ying , Liu Jinyan , Teng Choon Peng , Wang FuKe
Published: April 2021

One‐dimensional fillers such as rods and fibers have shown effective mechanical reinforcement in polymer nanocomposites, but their application in vat polymerization‐based 3D printing techniques was hindered due to the rapidly increased viscosity of the resin. In order to improve the fluidity of the composites without sacrificing the mechanical performance, herein we demonstrated that one‐dimensional hydroxyapatite (HAP) whiskers could be surface modified with 3‐(trimethoxysilyl) propyl methacrylate, to decrease the viscosity of the resulting resins and to enhance the interfacial adhesion between the filler and matrix. Rheology results showed that the resin was still fluidic with loading of HAP whiskers up to 20 wt%, with Young's modulus increased by a factor of 98% and the ultimate tensile strength increased by 26%. Successful printing of the resin on a DLP printer was achieved with high resolution and fine surface, and the biocompatibility test showed an increase in cell viability with the addition of HAP whiskers. These results provide a promising approach to develop high‐performance printable resin for orthopedic and related bio‐printing.
Poly(vinyl alcohol)‐assisted preparation of melamine resin‐derived thick plate‐like porous carbon for high‐performance all‐solid‐state supercapacitors
Authors: Liu Yujiao , Niu Ben , Qi Rixin , Zhang Yuheng , Zhang Yunqiang , Li Mei
Published: April 2021

A simple and efficient approach derived from melamine formaldehyde (MF) resin was explored to synthesize porous thick plate‐like carbon (TPC) using poly(vinyl alcohol) (PVA) as reagent and dispersant. Ultra‐large lateral dimension of over 100–150 μm is achieved with high nitrogen (12.4 at%)/oxygen (10.8 at%) content after MF prolysis at 700°C. The introduction of PVA provides abundant micro and mesopores inside TPC and the folded layered structure increases the specific surface area both of which are beneficial to improve the electrochemical properties of the electrode. The optimized TPC (MTPC‐0.2) shows remarkable rate capability as the current densities increased from 0.5 A/g (409.3 F/g) to 20 A/g (330.0 F/g). Further, the all‐solid‐state supercapacitors built from two identical MTPC‐0.2 electrodes delivers dramatically improved volumetric specific capacitance (8.6 F/cm3 at 1.2 mA/cm2) and volumetric energy density (1.20 at 21.42 mW/cm3) based on the total volume of device.
Classifying flow regimes of the Amazon basin
Authors: Siddiqui Sharmin F. , Zapata‐Rios Xavier , Torres‐Paguay Sandra , Encalada Andrea C. , Anderson Elizabeth P. , Allaire Mark , da Costa Doria Carolina Rodrigues , Kaplan David A.
Published: April 2021

The Amazon River basin contains a vast diversity of lotic habitats and accompanying hydrological regimes. Further understanding the spatial distribution of flow regimes across the Amazon can be useful for recognizing riverine ecohydrological processes and informing river management and conservation, especially in areas with limited or inconsistent streamflow monitoring.

This study compares four inductive approaches for classifying streamflow regimes across the Amazon using an unprecedented compilation of streamflow records from Bolivia, Brazil, Colombia, Ecuador, and Peru.

Inductive classification schemes use attributes of streamflow data to categorize river reaches into similar classes, which then may be generalized to understand streamflow behaviour at the basin scale. In this study, classification was accomplished through hierarchical clustering of 67 flow metrics calculated using indicators of hydrologic alteration (IHA) and daily streamflow data from median annual hydrographs (MAHs) for 404 stations (representing >7,000 station‐years) across five Amazonian countries.

Classification was performed using both flow magnitude‐inclusive and flow magnitude‐independent datasets. For flow magnitude‐independent methods, optimal solutions included six or seven primary hydrological classes for IHA and MAH datasets; for approaches that retained magnitude, variance was sufficiently large to prevent convergence to a specific number of classes.

Across methods, class membership was strongly associated with the timing, frequency, and rate of change of flow, and spatially coherent clusters were associated with seasonal, elevational, and stream‐order gradients. These results highlight the diversity of flow regimes across the Amazon and provide a framework for studying relationships between hydrological regimes and ecological responses in the context of changing climate, land use, and human‐induced hydrological alteration.

The methodology applied provides a data‐driven approach for classifying flow regimes based on observed data. When coupled with ecological knowledge and expertise, these classifications can be used to develop ecohydrologically informed and management‐relevant conservation practices.
A two‐step method for 4‐pin form‐closure gripper with grasping force optimization
Authors: Li Rui , Li Yinlin , Su Xiaojie
Published: April 2021

Grasp planning and the grasping force optimization are challenging issues associated with the dexterous robotic hand grasping problem. To ensure a safe, fast, and stable grasp for robots, careful determination of the grasping points and the grasping forces is required. The former creates an open question because of the availability of multiple solutions. The latter is formulated as a problem for minimizing an objective function subject to form‐closure constraints and balance constraints of external forces. In this work, we propose a novel approach for the grasping force optimization of the 4‐pin environmental constraint‐based form‐closure grasp using dynamic neural networks. To find a form‐closure grasp, we propose an environmental constraint‐based algorithm and convert it to a problem of finding the local minima of a constraint region, resulting in an easy determination of the grasping points with the guarantee of grasping safety. To satisfy the grasping force limit of the contact points, we solve the grasping force optimization problem with friction constraint, which maximize the efficiency of the applied force and power of the dexterous hand. The proposed approach is evaluated with 4‐pin gripper, and the result demonstrates that we can plan a safe, fast, and stable grasp from any initial state to a form‐closure grasping state.