bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Extracting Solvents on the Physicochemical Properties of Alchornea cordiforlia, Hura crepitans, Irvingia gabonensis and Pycnanthus angollensis Oils
Authors: Akpe Michael Akomaye , Inezi Faith Patrick
Published: April 2020

Aims and Objectives: To determine the effect of extracting solvents on the physicochemical properties of oils extracted from four locally available plant seeds in Nigeria namely: Alchornea cordiforlia, Hura crepitans, Irvingia gabonensis and Pycnanthus angollensis using three different solvents namely; n-Hexane, Petroleum ether and Dichloromethane.

Place and Duration of Study: Department of Chemistry Laboratory, University of Calabar, Nigeria. The study was carried out between August 2019 and December 2019, (5 months).

Methodology: Each plant seed was ground into a paste and extracted for its oil using a Soxhlet extractor and three different solvents namely; n-Hexane, Petroleum ether and Dichloromethane. The physicochemical properties of the oils were then analysed.

Results: The results revealed the mean values of the physicochemical properties of A. cordifolia oil extracted using Hexane, Petroleum ether and Dichloromethane respectively were % yield (36.50, 34.50 and 32.00), specific gravity (0.91, 0.91 and 0.92), flash point (156.00, 155.00 and 191.00°C), Acid value (23.76, 25.10 and 26.80 mEqk-1), % free fatty acid (11.88, 12.55 and 13.40), Peroxide value (6.56, 6.38 and 6.90 mEqK-1), Saponification value (163.20, 156.40 and 165.50 mgKOHg-1) and iodine value (25.40, 48.60 and 46.50 g/100 g). The mean values of the properties of H. crepitans oil across the 3 solvents respectively were % yield (32.20, 31.50 and 29.00), specific gravity (0.92, 0.93 and 0.94), flash point (271.00, 259.00 and 240.00°C), Acid value (21.00, 21.80 and 22.20 mEqk-1), % free fatty acid (10.50, 10.90 and 11.10), Peroxide value (5.85, 6.26 and 7.10 mEqK-1), Saponification value (172.50, 190.40 and 185.60 mgKOHg-1) and Iodine value (43.60, 34.50 and 26.90 g/100 g). Properties of the I. gabonensis oil were % yield (33.20, 34.00 and 32.50), Specific gravity (0.92, 0.94 and 0.94), flash point (230.00, 236.00 and 260.00°C), Acid value (3.72, 3.70 and 3.90 mEqk-1), % free fatty acid (1.86, 1.85 and 1.95), Peroxide value (2.98, 4.26 and 3.63), Saponification value (239.50, 252.40 and 245.80) and Iodine value (25.30, 11.70 and 44.20). Mean values of P. angollensis oil properties were % yield (34.10, 36.20 and 33.00), Specific gravity (0.92, 0.92 and 0.93), flash point (260.00, 258.00 and 256.00°C), Acid value (23.68, 25.00 and 26.00 mEqk-1), % free fatty acid (11.84, 12.50 and 13.00), Peroxide value (4.25, 5.30 and 5.96), Saponification value (25.30, 52.50 and 57.30) and Iodine value (25.20, 11.68 and 44.40). The odour, colour and physical state of all the oils at room temperature was the same across the 3 solvents.

Conclusion: The results indicate that the physicochemical properties of the oils vary with the extracting solvent and its polarity. Their properties revealed that some of them can be used for many domestic and industrial purposes especially for the making of paints, soap, cosmetics, lubricants and varnishes.
Bacteriological Analysis of Beef Production Chain in Birnin Kebbi Metropolis of Kebbi State, Nigeria
Authors: Joseph A. Famubo, , Aishatu Isiaka, , Yusuf B. Abbas,
Published: April 2020

The hygiene status of most abattoirs and retail outlets in Nigeria is very poor, and it contributes to the unacceptable level of bacteria load in beef, and poses a health risk to consumers. This study examined the bacteriological analysis of beef production chain in Birnin Kebbi metropolis. A total of 100 samples of meat, water and surface swab in Main Market, GRA, Badariya, Bayan Kara and Rafin Atiku, Birnin Kebbi Central abattoir and retail meat shops were collected aseptically, processed and analyzed. Meat from retail outlets were mostly contaminated by Staphylococcus aureus (24.4%), followed by Escherichia coli (17.3%), Klebsiella pneumonia (9.8%), Salmonella typhimurium (9.1%), Entrobater aerogenes (8.5%), Streptococcus pyogenes (8.1%), Proteus vulgaris (7.8%), Micrococcus luteus (7.8%) and Pseudomonas aeruginosa (7.2%). In the abattoirs contact surfaces, contamination occurred mostly by Staphylococcus aureus (23.4%), Salmonella typhimurium (18.2%), Escherichia coli (16.9%), Entrobater aerogenes (9.1%), Streptococcus pyogenes (7.8%), Klebsiella pneumonia, Proteus vulgaris, and Pseudomonas aeruginosa (6.5% each) and Micrococcus luteus (5.2%). The findings revealed a high bacterial load in both abattoir and retail meat outlets. In order to safeguard the health of the public against the risks of food borne infections, there is a need to educate and advocate good sanitation and meat handling practices in the abattoir and beef retail outlets.
Microorganisms Associated with the Fermentation of Gari Fortified with Sprouted Mung Beans Flour
Authors: Bayode Abiola Abiodun , Okhonlaye Ojokoh, Anthony
Published: April 2020

Gari’ is consumed regularly by large populations of Nigeria, therefore, it is an excellent means of improving the diet of people through fortification with nutritionally rich foods hence, this study aim to produce ‘Gari’ by co-fermenting cassava mash and sprouted mung bean flour in different ratios in order to assess the effect on the nutritional composition as compared to a standard produced without sprouted mungbeans (SMF) flour fortification. In different ratios, composites of cassava mash (CM) and the sprouted mungbeans flour (SMF) were made (5% SMF + 95% CM, 10% SMF + 90% CM, 15% SMF + 85% CM; and 100% CM which serve as the control) and fermented using semi-solid state fermentation for four days. The Gari was then produced following the standard method of dewatering, sieving and roasting. Isolation of microorganism during the fermentation was carried out using standard microbiological techniques and identification was done using conventional and molecular techniques. The total bacterial (cfu/ml) of the fermented samples increased during the first day of fermentation, and reduced on subsequent days in all samples with the bacterial count ranging from 1.21 x105 CFU/g to 2.45 x105 CFU/g. The organisms isolated include Lysinibacillus alkalisoli, Proteus mirabilis, Pediococcus acidilactici, Lactobacillus plantarum, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Penicillium sclerotiorum, Diutina catenulate, Rhizopus stolonifer, Trichoderma viridae, Saccharomyces cerevisiae. Most of the organisms isolated during the first and second day of fermentation such as Proteus spp, Staphylococcus spp, Bacillus spp, Bacillus spp, Diutina spp and Trichoderma spp, later disappeared toward the later days of the fermentation. Lactic acid bacteria, mold and yeast isolates such as Lactobacillus plantarum, Pediococcus spp. Penicillium spp and Saccharomyces cerevisiae dominate toward the later stage of the fermentation in all the fermented samples. Molecular identification of the bacterial isolates shows that Lysinibacillus alkalisoli, Proteus mirabilis, Pediococcus acidilactici, Lactobacillus plantarum, Staphylococcus aureus, Bacillus subtilis and Bacillus cereus were present in the samples. The outcome of this research showed that co-fermentation of cassava mash and sprouted mung bean flour eliminates pathogenic microorganisms and encourages the growth of beneficial microorganism in mung bean fortified Gari production.
Centrosome amplification is a frequent event in circulating tumor cells from subjects with metastatic breast cancer
Authors: Singh Ashok , Denu Ryan A. , Wolfe Serena K. , Sperger Jamie M. , Schehr Jennifer , Witkowsky Tessa , Esbona Karla , Chappell Richard J. , Weaver Beth A. , Burkard Mark E. , Lang Joshua M.
Published: April 2020

Centrosome amplification (CA) is a common phenomenon in cancer, promotes genomic stability and cancer evolution, and has been reported to promote metastasis. CA promotes a stochastic gain/loss of chromosomes during cell division, known as chromosomal instability (CIN). However, it is unclear whether CA is present in circulating tumor cells (CTCs), the seeds for metastasis. Here, we surveyed CA in CTCs from human subjects with metastatic breast cancer. CTCs were captured by CD45 exclusion and selection of EpCAM‐positive cells using an exclusion‐based sample preparation technology platform known as VERSA (versatile exclusion‐based rare sample analysis). Centriole amplification (centrin foci> 4) is the definitive assay for CA. However, determination of centrin foci is technically challenging and incompatible with automated analysis. To test if the more technically accessible centrosome marker pericentrin could serve as a surrogate for centriole amplification in CTCs, cells were stained with pericentrin and centrin antibodies to evaluate CA. This assay was first validated using breast cancer cell lines and a nontransformed epithelial cell line model of inducible CA, then translated to CTCs. Pericentrin area and pericentrin area x intensity correlate well with centrin foci, validating pericentrin as a surrogate marker of CA. CA is found in CTCs from 75% of subjects, with variability in the percentage and extent of CA in individual circulating cells in a given subject, similar to the variability previously seen in primary tumors and cell lines. In summary, we created, validated, and implemented a novel method to assess CA in CTCs from subjects with metastatic breast cancer. Such an assay will be useful for longitudinal monitoring of CA in cancer patients and in prospective clinical trials for assessing the impact of CA on response to therapy.
Bypassing the Immunosuppression of Myeloid‐Derived Suppressor Cells by Reversing Tumor Hypoxia Using a Platelet‐Inspired Platform
Authors: Zhang Chao , Xia Donglin , Liu Jiahao , Huo Da , Jiang Xiqun , Hu Yong
Published: April 2020

Myeloid‐derived suppressor cells (MDSCs) are garnering increasing attention given their role in tumor development. Herein, a nano‐enabled strategy is demonstrated for the eradication of tumor‐infiltrated MDSCs by reversing hypoxia. Oxygen‐independent photodynamic bismuth tungstate nanoparticles (Bi2WO6 NPs) are loaded into reactive oxygen species (ROS) responsive platelet membranes (PMs) to form a hybrid (PM‐BiW NPs). P‐Selectin on PMs endows PM‐BiW NPs with selectivity toward cancer cells. Once in the tumor, laser illumination stimulates the Bi2WO6 NPs photothermally and photodynamically, which produces enormous quantities of hydroxyl radicals. These hydroxyl radicals help rupture the PM and mitigate hypoxia with the assistance of ionizing radiation. This effectively remodels the tumor microenvironment toward one disfavoring the recruitment of MDSCs and contributes to better prognosis. To better understand the mechanism, the expression levels of a set of markers are monitored. It is found that the downregulations of hypoxia‐inducible factor‐1α, ectonucleoside triphosphate diphosphohydrolase 2, and adenosine‐5‐phosphoricacid are behind the blocked infiltration of MDSCs. This platform strategy offers a promising approach to overcome the immunosuppression caused by MDSCs through a trimodal therapy integrating the power of photothermal and photodynamic therapy in addition to radiation therapy.
High ZT 2D Thermoelectrics by Design: Strong Interlayer Vibration and Complete Band‐Extrema Alignment
Authors: Zhang Xiwen , Liu Chenhan , Tao Yi , Li Yunhai , Guo Yilv , Chen Yunfei , Zeng Xiao Cheng , Wang Jinlan
Published: April 2020

The discovery of a record high figure of merit (ZT) of ≈2.6 associated with bulk SnSe has stimulated considerable enthusiasm in searching for 2D systems with similar high ZT. However, previously reported 2D thermoelectric (TE) materials generally possess very low ZT due to the high lattice thermal conductivity (κL) and/or small power factor (PF). Herein, a very high ZT (≈2.08) value associated with atomically thin 2D KAgSe nanosheet is reported, which also exhibits an unprecedented low intrinsic κL (≈0.03 Wm−1 K−1 at 700 K for trilayer) and fairly large PF. The low κL mainly stems from the high lattice anharmonicity induced by both the “interfacial shear slip” vibrations and the asymmetric “AgSe pair” vibrations from distorted AgSe4 tetrahedrons. Meanwhile, the complete band‐extrema alignment and coexistence of heavy and light bands result in an optimal Seebeck coefficient and electrical conductivity, thereby a large PF. This work suggests not only an alternative way to acquiring high lattice anharmonicity but also a highly competitive 2D TE candidate for wide applications.
Structure Design Reveals the Role of Au for ORR Catalytic Performance Optimization in PtCo‐Based Catalysts
Authors: Guo Li‐Ming , Zhang Dong‐Feng , Guo Lin
Published: April 2020

Au‐incorporation is a promising strategy to retard composition‐loss in Pt‐based catalyst. However, the unclear mechanism limits guided catalyst design and the performance optimization. Here, direct evidence is provided to validate the outward diffusion of Au atoms in Au‐core/Pt‐based‐shell structures. A Co interlayer is built between the Au‐core and PtCo‐based shell to exclude the possibility of atomic diffusion caused by interfacial alloying. In conjunction with the improved catalytic durability of the Au‐core@Pt‐based‐shell structure, it is reasonable to conclude that it is the subsurface segregated Au atoms rather than interfacial interaction that boosts the catalytic durability of Au‐core/Pt‐based‐shell structured catalysts towards oxygen reduction reaction. More importantly, by constructing Au‐core@Co‐interlayer@PtCoAu‐shell multilayer structure, the specific (1.730 mA cm−2) and mass (0.692 A mg−1Pt) activities are enhanced 7‐ and 4‐ fold relative to the commercial Pt/C. After 10 000 cycles of accelerated durability test, the mass activity loss for the multilayered catalyst is as low as 6.14% while the loss exceeds 35% for the commercial Pt/C catalyst. The improved catalytic performance of the Au@Co@PtCoAu multilayer structure can be ascribed to the finely modulated electronic structure and the compensated composition loss owing to the delicate structure and composition profile design.
Geometrically Structured Nanomaterials for Nanosensors, NEMS, and Nanosieves
Authors: Seo Min‐Ho , Yoo Jae‐Young , Jo Min‐Seung , Yoon Jun‐Bo
Published: April 2020

Recently, geometrically structured nanomaterials have received great attention due to their unique physical and chemical properties, which originate from the geometric variation in such materials. Indeed, the use of various geometrically structured nanomaterials has been actively reported in enhanced‐performance devices in a wide range of applications. Recent significant progress in the development of geometrically structured nanomaterials and associated devices is summarized. First, a brief introduction of advanced nanofabrication methods that enable the fabrication of various geometrically structured nanomaterials is given, and then the performance enhancements achieved in devices utilizing these nanomaterials, namely, i) physical and gas nanosensors, ii) nanoelectromechanical devices, and iii) nanosieves are described. For the device applications, a systematic summary of their structures, working mechanisms, fabrication methods, and output performance is provided. Particular focus is given to how device performance can be enhanced through the geometric structures of the nanomaterials. Finally, perspectives on the development of novel nanomaterial structures and associated devices are presented.
Hard Carbon Nanosheets with Uniform Ultramicropores and Accessible Functional Groups Showing High Realistic Capacity and Superior Rate Performance for Sodium‐Ion Storage
Authors: Xia Ji‐Li , Yan Dong , Guo Li‐Ping , Dong Xiao‐Ling , Li Wen‐Cui , Lu An‐Hui
Published: April 2020

Hard carbon attracts considerable attention as an anode material for sodium‐ion batteries; however, their poor rate capability and low realistic capacity have motivated intense research effort toward exploiting nanostructured carbons in order to boost their comprehensive performance. Ultramicropores are considered essential for attaining high‐rate capacity as well as initial Coulombic efficiency by allowing the rapid diffusion of Na+ and inhibiting the contact of the electrolyte with the inner carbon surfaces. Herein, hard carbon nanosheets with centralized ultramicropores (≈0.5 nm) and easily accessible carbonyl groups (CO)/hydroxy groups (OH) are synthesized via interfacial assembly and carbonization strategies, delivering a large capacity (318 mA h g−1 at 0.02 A g−1), superior rate capability (145 mA h g−1 at 5.00 A g−1), and approximately 95% of reversible capacity below 1.00 V. Notably, a new charge model favoring fast capacitive sodium storage with dual potential plateaus is proposed. That is, the deintercalation of Na+ from graphitic layers is manifested as the low‐potential plateau region (0.01−0.10 V), contributing to stable insertion capacity; meanwhile, the surface desodiation process of the CO and OH groups corresponds to the high‐potential plateau region (0.40−0.70 V), contributing to a fast capacitive storage.
Plasmonic Hot‐Electron‐Induced Control of Emission Intensity and Dynamics of Visible and Infrared Semiconductor Quantum Dots
Authors: Sadeghi Seyed M. , Gutha Rithvik R. , Mao Chuanbin
Published: April 2020

Plasmonic hot‐electron‐assisted control of emission intensities and dynamics of CdSe/ZnS and infrared PbS quantum dots are studied. This is done by exploring the impact of Au/Si and Ag/Si Schottky junctions on the decay rates of such quantum dots when these junctions are placed in close vicinity of a Si/Al oxide charge barrier, forming metal‐oxide plasmonic metafilms. Such structures are used to investigate how metal‐dependent distributions of hot electrons and their capture via Schottky junctions can lead to suppression of the defect environments of quantum dots, offering a novel platform wherein off‐resonant (non‐Purcell) plasmonic processes are used to control exciton dynamics. These results show that Ag metafilms can enhance the emission of CdSe/ZnS quantum dots and elongate their lifetimes more than Au metafilms. This highlights the more efficient nature of Ag/Si Schottky junctions for hot electron excitation and capture. These results also show that such junctions can significantly suppress the nonradiative decay rates of PbS quantum dots at frequencies far from the plasmon resonances. These results demonstrate a field‐effect passivation of quantum dot defects via entrapment of hot electrons and control of emission intensities and dynamics of quantum dots via the nearly frequency‐independent electrostatic field of such electrons.
4D Printed Hydrogels: Fabrication, Materials, and Applications
Authors: Dong Yuting , Wang Shancheng , Ke Yujie , Ding Liucheng , Zeng Xianting , Magdassi Shlomo , Long Yi
Published: April 2020

4D printed objects are 3D printed structures whose shape, property, and functionality are able to self‐transform when exposed to a predetermined stimulus. The emerging field of 4D printing has attracted wide interest from both academia and industry since first introduced in 2013. Stimuli‐responsive hydrogels have become a competitive and versatile group of materials for 4D printed devices due to their good deformability, promising biocompatibility, simple manufacturing, and low cost. This review aims to provide a summary of the current progress of hydrogel‐based 4D printed objects and devices based on their fabrication techniques, materials, and applications. Herein, presented are: the characteristics of different additive manufacturing methods such as direct ink writing, fused deposition modeling, and stereolithography; the properties of various stimuli‐responsive hydrogels such as poly(N‐isopropylacrylamide) and poly(N,N‐dimethylacrylamide), alginate, etc.; and diverse applications of 4D printed hydrogels such as actuators, cellular scaffolds, and drug release devices. Opportunities and challenges for 4D printed hydrogels are discussed and prospects for future development are elaborated.
Tuning Optical Properties of BODIPY Dyes by Pyrrole Conjugation for Photoacoustic Imaging
Authors: Merkes Jean Michél , Lammers Twan , Kancherla Rajesh , Rueping Magnus , Kiessling Fabian , Banala Srinivas
Published: April 2020

Photoacoustic imaging (PAI) is increasingly employed in (pre‐) clinical research, thus, development of suitable contrast agents, in particular fluorescence‐quenched chromophores, for PAI is of high importance. Small molecule dyes are appropriate due to favorable circulation, excretion properties, and ease of conjugation to targeting moieties. The BODIPY chromophores have been widely used in bioimaging, yet they are not ideal for PAI due to high fluorescence. Hence, here nonfluorescent BODIPY are designed by 1H‐pyrrole conjugation (PyBODIPY) to apply as probes for PAI. The PyBODIPYs exhibit absorption maxima up to 800 nm, and PA signal could be detected in concentrations of 1 nmol mL−1 and 35 pmol mm−3, by tube and tissue phantom, respectively. In addition to nonfluorescent, PyBODIPYs are non‐phototoxic, photostable, and show high molar extinction coefficients, as well as inertness toward nucleophilic addition. PyBODIPYs are modified with PEG‐400, to improve aqueous solubility and to enable in vivo imaging. Thus, PyBODIPY is an attractive small molecule to use as PA contrast agent, which could be coupled to targeting ligands for in vivo use. In addition, 1H‐pyrrole conjugation might be applied to the design of novel near‐infrared ranged quenchers suitable for PAI, and promote the development of probes for clinical translation.
Synthesis of Unnatural α‐Amino Acid Derivatives via Light‐Mediated Radical Decarboxylative Processes
Authors: Merkens Kay , Aguilar Troyano Francisco José , Djossou Jonas , Gómez‐Suárez Adrián
Published: April 2020

Unnatural amino acids (UAAs) are key building blocks with widespread application across several scientific fields. Therefore, it is highly attractive to develop straightforward and simple methodologies capable of granting quick access to these species. Herein we report a light‐mediated protocol for the synthesis of UAA via radical decarboxylative processes. This methodology, which employs readily available and abundant starting materials – such as carboxylic and α‐keto acids – proceeds under very mild reaction conditions and shows a high functional group tolerance. In addition, the products of the radical reaction can be readily derivatized to grant rapid access to complex UAAs.

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Bacterial community dissimilarity in soils is driven by long‐term land‐use practices
Authors: Sengupta Aditi , Hariharan Janani , Grewal Parwinder S. , Dick Warren A.
Published: April 2020

Land‐use practices impact soil microbial functionality and biodiversity, with reports suggesting that anthropogenic activities potentially result in reduced microbial functions and loss of species. The objective of this study was to assess the effect of long‐term (>50 yr) land use (natural forest and grassland, and agricultural land) on soil bacterial community structure. A high‐throughput sequencing‐by‐synthesis approach of the 16S rRNA gene was used to study bacterial community and predicted functional profiles of Alfisols, as affected by variables including land‐use (forest, grass, agricultural) and soil/crop management (rotation and tillage) in long‐term experimental plots in Hoytville, OH. The distribution of the abundant phyla was different across samples. No‐till soils showed higher diversity indices than the plow‐till (PT) soils. Ordinations across locations suggested that no‐till soils had distinctly different community structure compared with plow‐till soils, while crop rotation within the no‐till plot had highest number of taxa. Overall land use (forest, grass, agronomic treatment) and tillage (within agricultural soils) were found to be significant when evaluating bacterial community dissimilarity. Predictive functional profiles showed that the forest soil had greatest proportion of PICRUSt‐assignable gene functions followed by the no‐till and grassland soils whereas plow‐till soils had the lowest predicted gene abundances across all samples. The results provide a view of soil bacterial diversity and predictive functional capacity in long‐term land‐use and soil/crop management practices, with a potential to inform future experiments to increase our understanding of long‐term impacts of land use on microbial community structure and function.
Introducing the North American project to evaluate soil health measurements
Authors: Norris Charlotte E. , Bean G. Mac , Cappellazzi Shannon B. , Cope Michael , Greub Kelsey L.H. , Liptzin Daniel , Rieke Elizabeth L. , Tracy Paul W. , Morgan Cristine L.S. , Honeycutt C. Wayne
Published: April 2020

The North American Project to Evaluate Soil Health Measurements was initiated with the objective to identify widely applicable soil health measurements for evaluation of agricultural management practices intended to improve soil health. More than 20 indicators were chosen for assessment across 120 long‐term agricultural research sites spanning from north‐central Canada to southern Mexico. The indicators being evaluated include common standard measures of soil, but also newer techniques of visible and near‐infrared reflectance spectroscopy, a smart phone app, and metagenomics. The aim of using consistent sampling and analytical protocols across selected sites was to provide a database of soil health indicator results that can be used to better understand how land use and management has affected the condition of soil ecosystem provisioning for agricultural biomass production and water resources, as well as nutrient and C cycling. The objective of this paper is to provide documentation of the overall design, and methods being employed to identify soil health indicators sensitive across agricultural management practices, pedologies, and geographies.
Corn and sudangrass intercropped with Kura clover for Midwestern pastures
Authors: Nieman Christine C. , Albrecht Kenneth A. , Schaefer Daniel M.
Published: April 2020

Warm‐season annual grasses have potential to increase the productivity of Midwestern grazing systems in mid‐summer when cool‐season species production slumps. This research investigated forage nutritive value and steer performance for two warm‐season annual grasses, corn (Zea mays L.) and sudangrass [Sorghum bicolor (L.) Moench.], intercropped with Kura clover (Trifolium abiguum M. Bieb.). Mixtures were rotationally grazed with Holstein (Bos taurus; 242 kg, n = 180 yr−1) steers from 2014 to 2016. Corn–Kura clover (C‐KC) and sudangrass–Kura clover (SG‐KC) were grazed for 24 d from mid‐July to mid‐August and SG‐KC regrowth was grazed an additional 24 d from mid‐Aug to mid‐September. Forage harvested was greater (P < .05) for SG‐KC (3442 ± 223 kg ha−1) than C‐KC (2426 ± 193 kg ha−1). A mixture × year effect (P = .03) was detected for in vitro true digestibility (IVTD) and all forage nutritive variables had year effects (P < .01). Crude protein did not differ between treatments (P = .30), neutral detergent fiber (NDF) was lower (P < .01), and IVTD and NDF digestibility were higher (P < .05) in C‐KC. A mixture × year effect (P < .05) existed because heat stress suppressed average daily gain in the C‐KC grazing session in 2016. Steer gain per hectare was greater for SG‐KC (P < .01), with 318 kg ha−1 and 195 kg ha−1 for SG‐KC and C‐KC, respectively. Despite greater forage nutritive value in C‐KC, SG‐KC resulted in greater animal gain per hectare due to regrowth potential after first grazing.
Learning from amyloid trials in Alzheimer's disease. A virtual patient analysis using a quantitative systems pharmacology approach
Authors: Geerts Hugo , Spiros Athan
Published: April 2020

Background

Many trials of amyloid‐modulating agents fail to improve cognitive outcome in Alzheimer's disease despite substantial reduction of amyloid β levels.

Methods

We applied a mechanism‐based Quantitative Systems Pharmacology model exploring the pharmacodynamic interactions of apolipoprotein E (APOE), Catechol ‐O ‐methyl Transferase (COMTVal158Met), and 5‐HT transporter (5‐HTTLPR) rs25531 genotypes and aducanumab.

Results

The model predicts large clinical variability. Anticipated placebo differences on Alzheimer's Disease Assessment Scale (ADAS)‐COG in the aducanumab ENGAGE and EMERGE ranged from 0.77 worsening to 1.56 points improvement, depending on the genotype‐comedication combination. 5‐HTTLPR L/L subjects are found to be the most resilient. Virtual patient simulations suggest improvements over placebo between 4% and 20% at the 10 mg/kg dose, depending on the imbalance of the 5‐HTTLPR genotype and exposure. In the Phase II PRIME trial, maximal anticipated placebo difference at 10 mg/kg ranges from 0.3 worsening to 5.3 points improvement.

Discussion

These virtual patient simulations, once validated against clinical data, could lead to better informed future clinical trial designs.
Predicting a Sharp Decline in Selectivity for Catalytic Esterification of Alcohols from van der Waals Interactions
Authors: Reece Christian , Luneau Mathilde , Friend Cynthia M. , Madix Robert J.
Published: April 2020

Controlling the selectivity of catalytic reactions is a critical aspect of improving energy efficiency in the chemical industry; thus, predictive models are of key importance. Herein the performance of a heterogeneous, nanoporous Au catalyst is predicted for the complex catalytic self‐coupling of the series of C2–C4 alkyl alcohols, based solely on the known kinetics of the elementary steps of the catalytic cycle for methanol coupling, using scaling methods augmented by density functional theory. Notably, a sharp decrease in selectivity for ester formation with increasing molecular weight to favor the aldehyde due to van der Waals interactions of reaction intermediates with the surface was predicted and subsequently verified quantitatively by experiment. Further, the agreement between theory and experiment clearly demonstrates the efficacy of this approach for building a predictive model of catalytic behavior for a homologous set of reactants using a small set of experimental information.
Judicious Choice of N‐Heterocycles for the Realization of Sky‐Blue‐ to Green‐Emitting Carbazolylgold(III) C^C^N Complexes and Their Applications for Organic Light‐Emitting Devices
Authors: Kwok Wing‐Kei , Tang Man‐Chung , Lai Shiu‐Lun , Cheung Wai‐Lung , Li Lok‐Kwan , Ng Maggie , Chan Mei‐Yee , Yam Vivian Wing‐Wah
Published: April 2020

A new class of sky‐blue‐ to green‐emitting carbazolylgold(III) C^C^N complexes containing pyrazole or benzimidazole moieties has been successfully designed and synthesized. Through the judicious choice of the N‐heterocycles in the cyclometalating ligand and the tailor‐made carbazole moieties, maximum photoluminescence quantum yields of 0.52 and 0.39 have been realized in the green‐ and sky‐blue‐emitting complexes, respectively. Solution‐processed and vacuum‐deposited organic light‐emitting devices (OLEDs) based on the benzimidazole‐containing complexes have been prepared. The sky‐blue‐emitting device shows an emission peaking at 484 nm with a narrow full‐width at half‐maximum of 57 nm (2244 cm−1), demonstrating the potential of this class of complexes in the application of OLEDs with high color purity. In addition, high maximum external quantum efficiencies of 12.3 % and a long operational half‐lifetime of over 5300 h at 100 cd m−2 have been achieved in the vacuum‐deposited green‐emitting devices.
The Huisgen Reaction: Milestones of the 1,3‐Dipolar Cycloaddition
Authors: Breugst Martin , Reissig Hans‐Ulrich
Published: April 2020

The concept of 1,3‐dipolar cycloadditions was presented by Rolf Huisgen 60 years ago. Previously unknown reactive intermediates, for example azomethine ylides, were introduced to organic chemistry and the (3+2) cycloadditions of 1,3‐dipoles to multiple‐bond systems (Huisgen reaction) developed into one of the most versatile synthetic methods in heterocyclic chemistry. In this Review, we present the history of this research area, highlight important older reports, and describe the evolution and further development of the concept. The most important mechanistic and synthetic results are discussed. Quantum‐mechanical calculations support the concerted mechanism always favored by R. Huisgen; however, in extreme cases intermediates may be involved. The impact of 1,3‐dipolar cycloadditions on the click chemistry concept of K. B. Sharpless will also be discussed.
Subnanometer Bimetallic Platinum–Zinc Clusters in Zeolites for Propane Dehydrogenation
Authors: Sun Qiming , Wang Ning , Fan Qiyuan , Zeng Lei , Mayoral Alvaro , Miao Shu , Yang Ruoou , Jiang Zheng , Zhou Wei , Zhang Jichao , Zhang Tianjun , Xu Jun , Zhang Peng , Cheng Jun , Yang Dong‐Chun , Jia Ran , Li Lin , Zhang Qinghong , Wang Ye , Terasaki Osamu , Yu Jihong
Published: April 2020

Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt‐based catalysts usually suffer from short‐term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand‐protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt–Zn clusters inside silicalite‐1 (S‐1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6–54 h−1 and specific activity of propylene formation of 65.5 mol
 gPt−1 h−1 (WHSV=108 h−1) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S‐1‐H catalyst even after 13000 min on stream (WHSV=3.6 h−1), affording an extremely low deactivation constant of 0.001 h−1, which is 200 times lower than that of the PtZn4/Al2O3 counterpart under the same conditions. We also show that the introduction of Cs+ ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles.
Prismarene: An Emerging Naphthol‐Based Macrocyclic Arene
Authors: Yang Liu‐Pan , Jiang Wei
Published: April 2020

Phenol‐based macrocyclic arenes have been widely used in supramolecular chemistry, significantly enriching the toolbox of the field. In contrast, naphthol‐based macrocyclic arenes are rather underdeveloped. Very recently, Gaeta and co‐workers successfully synthesized such macrocycles (referred to as prism[n]arenes) with good guest‐binding ability by reacting 2,6‐dimethoxynaphthalene with paraformaldehyde under optimized conditions. In view of the simple synthesis and good host–guest chemistry, we anticipate that this macrocycle will find similar success and wide applications as the phenol‐based macrocyclic arenes.
Urethane acrylate‐based photosensitive resin for three‐dimensional printing of stereolithographic elastomer
Authors: Deng Yuhao , Li Jie , He Zuhan , Hong Jiang , Bao Jianjun
Published: April 2020

Three‐dimensional (3D) printing elastomers have received wide attention because of their wide applications in many fields. In this work, we report a urethane acrylate‐based photosensitive resin compound for 3D printing whose cured materials are elastic. This resin consists of bifunctional urethane acrylate (Royji 426 as the main matrix, monofunctional urethane acrylate (Royji 425), and isobornyl methacrylate (IBMA) as the diluents, trimethylolpropane triacrylate (TMPTA) as the crosslinker, phenylbis(2,4,6‐trimethylbenzoyl)‐phosphine oxide (819) and 2‐hydroxy‐2‐methyl propiophenone (1173) as photoinitiators. The results indicate that the mechanical properties of cured materials can be tuned by adjusting the content of different components, but it is also accompanied by the changes in viscosity and volume shrinkage. Real‐time Fourier transform infrared spectroscopy was employed to explore the relationship between the photoinitiators and the rate of initiation, and then found the best photoinitiators formulation. The resultant resin exhibits tensile strength of 7.46 MPa, elongation of 180.6%, viscosity of 978.53 mPa·s at 25°C and the volume shrinkage rate of 4.15%. Some complicated structures can be printed with the photosensitive resin such as C60, hollow ball, wrist strap, and porous lattices. These architectures have excellent dimensional accuracy and can undergo any large deformation without damage. This manifested that this resin can provide a solution for existing 3D printing of elastomers.
Biosimilar Uptake in Academic and Veterans Health Administration Settings: Influence of Institutional Incentives
Authors: Baker Joshua F. , Leonard Charles E. , Lo Re Vincent , Weisman Michael H. , George Michael D. , Kay Jonathan
Published: April 2020

Objective

To compare uptake in the ordering of biosimilars at a Veterans Affairs Medical Center (VAMC) to that at an academic medical center, where institutional incentives for infused medications differ.

Methods

We performed a cross‐sectional study of medical record data and estimated institutional financial incentives at 2 medical centers in Philadelphia: 1) the University of Pennsylvania Health System (UPHS), and 2) the local VAMC. All ordering events for filgrastim or infliximab products were quantified over time and stratified according to product (biosimilar versus reference product) and center. Financial incentives to the institutions over time were determined based on actual drug costs for the VAMC and average sales prices (ASPs) and Medicare Part B reimbursement rates for UPHS.

Results

There were 15,761 infusions of infliximab at UPHS, of which 99% were for the reference product. There was a sharper decline in the use of reference products at the VAMC; 62% of the 446 infliximab infusions ordered at the VAMC were for the reference product. ASPs were consistently lower for biosimilar infliximab products, but the estimated institutional financial incentives remained similar over time for biosimilar and reference infliximab at UPHS. At the VAMC, the costs for 100‐mg vials of reference infliximab and infliximab‐abda were $623.48 and $115.58, respectively: a $507.90 (81%) savings per vial.

Conclusion

The uptake of infliximab biosimilars has been slow at an academic medical center compared to a nearby VAMC, where financial savings are realized by the institution from its use. Slow adoption of biosimilar medications may impact the rates of decline in costs.
Reliable actuator fault control of positive switched systems with double switchings
Authors: Junfeng Zhang , Li Miao , Raïssi Tarek
Published: April 2020

This paper proposes a novel double switchings reliable control for positive switched systems. Double switchings refer to the switchings of subsystems and faults. Considering the actuator faults during the system operation, a class of periodic switched actuator faults is first considered. A reliable controller is designed using linear copositive Lyapunov functions and an average dwell time switching rule is presented for the systems. Then, two average dwell time switching rules are given for the subsystems and the faults, respectively. A corresponding reliable controller is proposed in terms of linear programming. Compared with existing results, the novel approach contains three advantages: (i) the actuator faults of subsystems are allowed to be varying, (ii) two classes of detailed double switchings rules are designed, and (iii) the presented reliable control framework provides a new methodology to deal with the reliable control problem of general switched systems with faults. Finally, two examples are given to illustrate the validity of the presented results.
Comparison of the duration of hospital stay after laparoscopic or open distal pancreatectomy: randomized controlled trial
Authors: Björnsson B , Larsson A Lindhoff , Hjalmarsson C , Gasslander T , Sandström P
Published: April 2020

Background

Studies have suggested that laparoscopic distal pancreatectomy (LDP) is advantageous compared with open distal pancreatectomy (ODP) regarding hospital stay, blood loss and recovery. Only one randomized study is available, which showed enhanced functional recovery after LDP compared with ODP.

Methods

Consecutive patients evaluated at a multidisciplinary tumour board and planned for standard distal pancreatectomy were randomized prospectively to LDP or ODP in an unblinded, parallel-group, single-centre superiority trial. The primary outcome was postoperative hospital stay.

Results

Of 105 screened patients, 60 were randomized and 58 (24 women, 41 per cent) were included in the intention-to-treat analysis; there were 29 patients of mean age 68 years in the LDP group and 29 of mean age 63 years in the ODP group. The main indication was cystic pancreatic lesions, followed by neuroendocrine tumours. The median postoperative hospital stay was 5 (i.q.r. 4–5) days in the laparoscopic group versus 6 (5–7) days in the open group (P = 0·002). Functional recovery was attained after a median of 4 (i.q.r. 2–6) versus 6 (4–7) days respectively (P = 0·007), and duration of surgery was 120 min in both groups (P = 0·482). Blood loss was less with laparoscopic surgery: median 50 (i.q.r. 25–150) ml versus 100 (100–300) ml in the open group (P = 0·018). No difference was found in the complication rates (Clavien–Dindo grade III or above: 4 versus 8 patients respectively). The rate of delayed gastric emptying and clinically relevant postoperative pancreatic fistula did not differ between the groups.

Conclusion

LDP is associated with shorter hospital stay than ODP, with shorter time to functional recovery and less bleeding. Registration number: ISRCTN26912858 (www.isrctn.com).
Inhalable bacteriophage powders: Glass transition temperature and bioactivity stabilization
Authors: Chang Rachel Yoon Kyung , Kwok Philip Chi Lip , Khanal Dipesh , Morales Sandra , Kutter Elizabeth , Li Jian , Chan Hak‐Kim
Published: April 2020

Recent heightened interest in inhaled bacteriophage (phage) therapy for combating antibacterial resistance in pulmonary infections has led to the development of phage powder formulations. Although phages have been successfully bioengineered into inhalable powders with preserved bioactivity, the stabilization mechanism is yet unknown. This paper reports the first study investigating the stabilization mechanism for phages in these powders. Proteins and other biologics are known to be preserved in dry state within a glassy sugar matrix at storage temperatures (Ts) at least ~50°C below the glass transition temperature (Tg). This is because at (Tg − Ts) >50°C, molecules are sufficiently immobilized with reduced reactivity. We hypothesized that this glass stabilization mechanism may also be applicable to phages comprising mostly of proteins. In this study, spray dried powders of Pseudomonas phage PEV20 containing lactose and leucine as excipients were stored at 5, 25 or 50°C and 15 or 33% relative humidity (RH), followed by assessment of bioactivity (PEV20 stability) and physical properties. PEV20 was stable with negligible titer loss after storage at 5°C/15% RH for 250 days, while storage at 33% RH caused increased titer losses of 1 log10 and 3 log10 at 5 and 25°C, respectively. The plasticizing effect of water at 33% RH lowered the Tg by 30°C, thus narrowing the gap between Ts and Tg to 19–28°C, which was insufficient for glass stabilization. In contrast, the (Tg − Ts) values were higher (range, 46–65°C) under the drier condition of 15% RH, resulting in the improved stability which corroborated with the vitrification hypothesis. Furthermore, phage remained stable (≤1 log10) when the (Tg − Ts) value lay between 26–48°C, but became inactivated as the value fell below 20°C. In conclusion, this study demonstrated that phage can be sufficiently stabilized in spray dried powders by keeping the (Tg − Ts) value above 46°C, thus supporting the vitrification hypothesis that phages are stabilized by immobilization inside a rigid glassy sugar matrix. These findings provide a guide to better manufacture and storage practices of inhaled phage powder products using for translational medicines.
Daily medical education for confined students during coronavirus disease 2019 pandemic: A simple videoconference solution
Authors: Moszkowicz David , Duboc Henri , Dubertret Caroline , Roux Damien , Bretagnol Frédéric
Published: April 2020

The outbreak of coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 infection has recently spread globally and is now a pandemic. As a result, university hospitals have had to take unprecedented measures of containment, including asking nonessential staff to stay at home. Medical students practicing in the surgical departments find themselves idle, as nonurgent surgical activity has been canceled, until further notice. Likewise, universities are closed and medical training for students is likely to suffer if teachers do not implement urgent measures to provide continuing education. Thus, we sought to set up a daily medical education procedure for surgical students confined to their homes. We report a simple and free teaching method intended to compensate for the disappearance of daily lessons performed in the surgery department using the Google Hangouts application. This video conference method can be applied to clinical as well as anatomy lessons.
Development and external validation of a preoperative nomogram for predicting pathological locally advanced disease of clinically localized upper urinary tract carcinoma
Authors: Yoshida Takashi , Kobayashi Takashi , Kawaura Takayuki , Miyake Makito , Ito Katsuhiro , Okuno Hiroshi , Murota Takashi , Makita Noriyuki , Kawakita Mutsushi , Kawa Gen , Kitawaki Tomoki , Fujimoto Kiyohide , Matsuyama Hideyasu , Shiina Hiroaki , Azuma Haruhito , Ogawa Osamu , Kinoshita Hidefumi , Matsuda Tadashi
Published: April 2020

Objective

To develop and validate a preoperative nomogram to predict pathological locally advanced disease (pLAD) of clinically localized upper urinary tract urothelial carcinoma (UTUC) treated with extirpative surgery.

Methods

In total, 1101 patients with cN0M0 UTUC (development cohort, n = 604; validation cohort, n = 497) from 2 independent academic databases were retrospectively analyzed. pLAD was defined as pT3/4 and/or pN+. Multivariate logistic regression was used to develop a nomogram. The accuracy of the nomogram was evaluated with a receiver operating characteristic curve, calibration plot, and decision curve analysis.

Results

The development and validation cohorts comprised 204 (33.8%) and 178 (35.8%) patients with pLAD, respectively. The multivariate analyses showed that the neutrophil‐to‐lymphocyte ratio (hazard ratio [HR], 2.27; P < .001), chronic kidney disease (HR, 1.56; P = .032), tumor location (HR, 1.60; P = .029), hydronephrosis (HR, 2.71; P < .001), and local invasion on imaging (HR, 8.59; P < .001) were independent predictive factors. After bootstrapping, a well‐calibrated nomogram achieved discriminative accuracy of 0.77 in the development cohort. The decision curve analysis demonstrated improved risk prediction against threshold probabilities (≥8%) of pLAD. These results were consistent in the validation cohort.

Conclusion

Our novel nomogram allows for more highly accurate prediction of pLAD of UTUC. This nomogram integrates standard imaging and laboratory factors that help to identify patients who will benefit from preoperative chemotherapy, extended lymph node dissection, or both.