bluuebunny/crossref_metadata_2025 huggingface dataset:
Limestone increased coffee yield and profitability more than phosphogypsum or their combination
Authors: Parecido Renan J. , Soratto Rogério P. , Perdoná Marcos J. , Guidorizzi Fernando V. C. , Gomes Guilherme G. , Paula Rodrigo A. , Gitari Harun I.
Published: May 2021

Soil acidity and low concentrations of exchangeable Ca and Mg are among the main factors that limit the Arabica coffee (Coffea arabica L.) yield in Brazil. Constant fertilizations, especially with ammonium‐based N, contribute to acidification in the soil region where they are applied. Coffee producers wonder if limestone and phosphogypsum, isolated or combined, can increase coffee yields. A field experiment was conducted from 2015 to 2020 in southeastern Brazil to evaluate the effect of sole application of limestone and phosphogypsum, or their combined application to young coffee trees (2‐yr old), on plant nutrition, yield, and profitability of Arabica coffee crop. Treatments included three limestone rates (0, 2,100, and 4,200 kg ha−1), two phosphogypsum rates (0 and 2,300 kg ha−1), and their combinations, which were band applied under coffee plant canopy. Limestone, in association with phophogypsum or when sole‐applied, increased the pH and the concentration of Ca and Mg in the soil, whereas the application of phosphogypsum increased Ca and SO4–S concentration. Coffee yields were increased by the sole application of limestone and phosphogypsum (to a lesser extent), but not when they were combined. The most successful treatment was the sole application of limestone, with increases of up to 44% (613 kg ha−1 yr−1 on average) in yield and 43% in economic returns.
Wireless Electrohydrodynamic Actuators for Propulsion and Positioning of Miniaturized Floating Robots
Authors: Shigemune Hiroki , Pradidarcheep Kittamet , Kuwajima Yu , Seki Yumeta , Maeda Shingo , Cacucciolo Vito
Published: May 2021

Autonomous soft robots require compact actuators generating large strokes and high forces. Electro‐fluidic actuators are especially promising, they combine the advantages of electroactive polymers (low‐power consumption, fast response, and electrical powering) with the versatility of fluidic systems (force/stroke amplification). EHD (electrohydrodynamic) actuators are electro‐fluidic actuators whose motion results from charges being induced and accelerated in a liquid. They are extremely compact, silent, and low power (≤10 mW). They have been recently demonstrated in stretchable pumps and for the wireless propulsion of simple floating robots. This study demonstrates simultaneous wireless propulsion (2.5 mm s−1) and control of a 1 cm sized robot using a single DC signal. Voltage is applied between an electrode on the floating robot and a fixed one, both exposed to a dielectric liquid. Results support the underlying physical mechanism as EHD and characterize robot motion with different fluorocarbon liquids and voltages between 400 and 1800 V. Path following is demonstrated with a 3 × 3 array of electrodes. EHD actuators prove to be a simple, compact, low power alternative to magnetic and acoustic actuators for wireless powering and control of miniaturized robots, with applications in precision assembling at the micro/mesoscale, lab‐on‐chip, tactile displays, and active surfaces.
Maternal effects strengthen interactions of temperature and precipitation, determining seed germination of dominant alpine grass species
Authors: Veselá Andrea , Hadincová Věroslava , Vandvik Vigdis , Münzbergová Zuzana
Published: May 2021

Premise

Despite the existence of many studies on the responses of plant species to climate change, there is a knowledge gap on how specific climatic factors and their interactions regulate seed germination in alpine species. This understanding is complicated by the interplay between responses of seeds to the environment experienced during germination, the environment experienced by the maternal plant during seed development and genetic adaptations of the maternal plant to its environment of origin.

Methods

The study species (Anthoxanthum alpinum, A. odoratum) originated from localities with factorial combinations of temperature and precipitation. Seed germination was tested in conditions simulating the extreme ends of the current field conditions and a climate change scenario. We compared the performance of field‐collected seeds with that of garden‐collected seeds.

Results

A change to warmer and wetter conditions resulted in the highest germination of A. alpinum, while A. odoratum germinated the most in colder temperature and with home moisture. The maternal environment did have an impact on plant performance of the study species. Field‐collected seeds of A. alpinum tolerated warmer conditions better than those from the experimental garden.

Conclusions

The results demonstrate how knowledge of responses to climate change can increase our ability to understand and predict the fate of alpine species. Studies that aim to understand the germination requirements of seeds under future climates should use experimental designs allowing the separation of genetic differentiation, plasticity and maternal effects and their interactions, since all these mechanisms play an important role in driving species’ germination patterns.
Skeletal and molecular findings in 51 Cleidocranial dysplasia patients from Turkey
Authors: Berkay Ezgi Gizem , Elkanova Leyla , Kalaycı Tuğba , Uludağ Alkaya Dilek , Altunoğlu Umut , Cefle Kıvanç , Mıhçı Ercan , Nur Banu , Taşdelen Elifcan , Bayramoğlu Zuhal , Karaman Volkan , Toksoy Güven , Güneş Nilay , Öztürk Şükrü , Palandüz Şükrü , Kayserili Hülya , Tüysüz Beyhan , Uyguner Zehra Oya
Published: May 2021

Loss or decrease of function in runt‐related transcription factor 2 encoded by RUNX2 is known to cause a rare autosomal‐dominant skeletal disorder, cleidocranial dysplasia (CCD). Clinical spectrum and genetic findings in 51 CCD patients from 30 unrelated families are herein presented. In a majority of the patients, facial abnormalities, such as delayed fontanel closure (89%), parietal and frontal bossing (80%), metopic groove (77%), midface hypoplasia (94%), and abnormal mobility of shoulders (90%), were recorded following clinical examination. In approximately one‐half of the subjects, wormian bone (51%), short stature (43%), bell‐shaped thorax (42%), wide pubic symphysis (50%), hypoplastic iliac wing (59%), and chef's hat sign (44%) presented in available radiological examinations. Scoliosis was identified in 28% of the patients. Investigation of RUNX2 revealed small sequence alterations in 90% and gross deletions in 10% of the patients; collectively, 23 variants including 11 novel changes (c.29_30insT, c.203delAinsCG, c.423 + 2delT, c.443_454delTACCAGATGGGAinsG, c.505C > T, c.594_595delCTinsG, c.636_637insC, c.685 + 5G > A, c.1088G > T, c.1281delC, Exon 6–9 deletion) presented high allelic heterogeneity. Novel c.29_30insT is unique in affecting the P1‐driven long isoform of RUNX2, which is expected to disrupt the N‐terminal region of RUNX2; this was shown in two unrelated phenotypically discordant patients. The clinical findings highlighted mild intra‐familial genotype–phenotype correlation in our CCD cohort.
N‐Methoxy arenesulfonamide as a Sulfonyl Equivalent For Palladium‐Catalyzed Sulfonylation of Arenes Through C−H Activation
Authors: Ojha Subhadra , Panda Niranjan
Published: May 2021

The prevalence of sulfones in natural products, pharmaceutically active molecules and functional materials draw immense attention for their synthesis. Here, we report a palladium‐catalyzed protocol for synthesizing diaryl sulfones from the arenes through C−H activation. N‐methoxy arenesulfonamide was exploited as a potential sulfonyl donor by the cleavage of S−N bond through a radical pathway. The present methodology has several advantages: a simple, readily available catalytic system; the use of a stable sulfonyl donor; a relatively moderate excess of arene coupling partner for an undirected C−H activation process, along with the tolerances of aryl bromides and iodides, which in turn permits further cross‐coupling reactions to afford cross‐coupled sulfones.
Merging Electron Transfer with 1,2‐Metalate Rearrangement: Deoxygenative Arylation of Aromatic Amides with Arylboronic Esters
Authors: Jiao Jiwen , Wang Xiaoming
Published: May 2021

Amides are essentially inert carboxyl derivatives in many types of chemical transformations. In particular, deoxygenative C−C bond formation of amides to synthetically important amines is a long‐standing challenge for synthetic chemists due to the inertness of the resonance‐stabilized amide C=O bond. Herein, it is disclosed that by merging electron‐transfer‐induced activation with 1,2‐metalate rearrangement, a wide range of aromatic amides react smoothly with arylboron reagents, affording a series of biologically relevant diarylmethylamines as deoxygenative C−C bond cross‐coupling products. With its simplicity and versatility, this reaction shows great promise in the synthesis of amines from amides, which may open up new avenues in retrosynthetic planning and find widespread use in academia and industry.
Design, synthesis, and biological evaluation of 5‐aminotetrahydroquinoline‐based LSD1 inhibitors acting on Asp375
Authors: Yan Jiangkun , Gu Yanting , Sun Yixiang , Zhang Ziheng , Zhang Xiangyu , Wang Xinran , Wu Tianxiao , Zhao Dongmei , Cheng Maosheng
Published: May 2021

The abnormal expression of lysine‐specific histone demethylase 1 (LSD1) is associated with different cancer types, and LSD1 inhibitory activity seems to have high therapeutic potential in cancer treatment. Here, we report the design, synthesis, and biochemical evaluation of novel 5‐aminotetrahydroquinoline‐based LSD1 inhibitors. Among them, compounds A6, A8, B1–B5, and C4 showed preferable inhibitory effects on LSD1, with IC50 = 0.19–0.82 µM. Several potent compounds were selected to evaluate their antiproliferative activity on A549 cells and MCF‐7 cells with a high expression of LSD1. The potential binding modes of the compounds were revealed through molecular docking to rationalize the potency of compounds toward LSD1. Our data recognized that the 5‐aminotetrahydroquinoline scaffold may serve as a starting point for developing potent LSD1 inhibitors for cancer therapy.
Development of detection methods for the diagnosis and analysis of highly toxic metal phosphides: A comprehensive and critical review
Authors: Mohammadinejad Arash , Rizi Kobra Salimiyan , Oskuee Reza Kazemi , Aryan Ehsan , Meshkat Zahra , Ulianas Alizar , Rezayi Majid
Published: May 2021

Metal phosphides, especially aluminum phosphide, and phosphine (PH3) are widely used as insecticides and rodenticides for protection of grains during process of storage and transportation. The main reason of poisoning with this compound is related to the conscious ingestion of salts or accidental inhalation of PH3. So the early and accurate diagnosis of poisoning can significantly help to the effective clinical treatment or recognition of death cause. PH3 is somewhat unstable due to reaction with oxygen or hemoglobin leading to formation of oxy‐acids phosphorous. Here, we critically reviewed the literature introducing the quantitative and qualitative methods for the detection of metal phosphides, PH3, and its products. This study obviously demonstrates that during past years, different diagnosis methods have been remarkably progressed. Head‐space gas chromatography and confirmatory colorimetric methods have been as the most popular techniques. Also, the gas sensors are a promising method that must be more progressed.
Co‐translational folding of nascent polypeptides: Multi‐layered mechanisms for the efficient biogenesis of functional proteins
Authors: Maciuba Kevin , Rajasekaran Nandakumar , Chen Xiuqi , Kaiser Christian M.
Published: May 2021

The coupling of protein synthesis and folding is a crucial yet poorly understood aspect of cellular protein folding. Over the past few years, it has become possible to experimentally follow and define protein folding on the ribosome, revealing principles that shape co‐translational folding and distinguish it from refolding in solution. Here, we highlight some of these recent findings from biochemical and biophysical studies and their potential significance for cellular protein biogenesis. In particular, we focus on nascent chain interactions with the ribosome, interactions within the nascent protein, modulation of translation elongation rates, and the role of mechanical force that accompanies nascent protein folding. The ability to obtain mechanistic insight in molecular detail has set the stage for exploring the intricate process of nascent protein folding. We believe that the aspects discussed here will be generally important for understanding how protein synthesis and folding are coupled and regulated.
Serious games for teaching agile methods: A review of multivocal literature
Authors: Rodríguez Guillermo , González‐Caino Pablo C. , Resett Santiago
Published: May 2021

Serious games (SGs) have emerged to improve the commitment and performance of user players, since they perform an exact mission, integrating with the game mechanics, thus creating a very attractive mission. In software engineering (SE), SGs have been addressed to increase the commitment of developers. Moreover, the use of SGs is of great interest to train and train future professionals to experience situations that they could face in software development. This study presents a multivocal literature review (MLR) to systematize and categorize the state‐of‐the‐art of SGs for teaching Agile Methods. The MLR allowed software practitioners and teachers to identify cutting‐edge methods for evaluating SGs, application domains in which the assessments were carried out, and the main features considered for assessing the educational benefits of SGs. For academics and professionals eager to test SGs in the training field of Agile Methods, the findings are helpful to (i) provide evidence regarding the usage of games in SE education, (ii) design game‐based teaching/learning strategies, and (iii) offer a repertoire of tactics for assessing the use of SGs in SE courses. In conclusion, the knowledge collected was structured and classified to provide a response to our research questions, aimed at providing a summary of the key research in this area, as well as defining open issues in the field.
Review recent rulings involving student‐athlete discipline
Authors: Lyerly Eric
Published: May 2021

An overview of the key topics faced by campus administrators with citations to noteworthy cases, statutes, regulations, and additional sources.
A literature review exploring the mental health issues in academy football players following career termination due to deselection or injury and how counselling could support future players
Authors: Wilkinson Richard James
Published: May 2021

The aim of this literature review was to show the mental health impact to academy football players after career termination due to deselection or injury. The review will also broaden to look at research around career termination in other sports. The place where this type of support could be implemented is within football clubs, before, during and post‐deselection or career termination for injured players. Previous research on this subject has relied on player case studies and questionnaires, and this has been unable to provide any substitutional evidence that deselected players are been given appropriate support. This is fundamentally destructive for players considering the high percentage of them being released (99% being released before their scholarship and 85% afterwards). This review looks at the limited research that has been published over the last few years to gain a better understanding of how this serious issue is overlooked. It focuses on what support is currently available and provides evidence to show how professional associations such as the PFA (Professional Football Association) and the LFE (League Football Education) treat deselected football players. The findings indicate that while the Elite Player Performance Plan supports players through education and by funding better facilities for clubs, the model bypasses emotional and psychological support for players before, during and after deselection, leaving an opening for the introduction of counselling services to support the players through this transition.
A rare case of compartment syndrome and myonecrosis in a patient with hemoglobin SC disease
Authors: Al Moosawi Muntadhar , Ezzat Hatoon
Published: May 2021

Myonecrosis and compartment syndrome are rarely seen in sickle cell disease (SCD), and they have not been previously reported in HbSC disease. This case can potentially be recognized as the first case of a patient with HbSC presenting with spontaneous myonecrosis and compartment syndrome.
3D Printed Reactionware for Synthetic Electrochemistry with Hydrogen Fluoride Reagents
Authors: Heard David M. , Doobary Sayad , Lennox Alastair J. J.
Published: May 2021

Electrochemical fluorination reactions of organic compounds frequently employ hydrogen fluoride reagents that are corrosive. The corrosive nature of these reagents necessitates either the construction or purchase of cells that are stable to hydrogen fluoride, which require high‐cost materials, machining time and expertise. Herein, we offer an alternative solution using 3D printing, which is an inexpensive and rapid manufacturing technique. We have designed, printed and shared four different cell types in polypropylene and tested them in an electrochemical alkene difluorination reaction in the presence of triethylamine ⋅ 3HF and pyridinium poly ⋅ (HF).
What Is the Catalytic Mechanism of Enzymatic Histone N‐Methyl Arginine Demethylation and Can It Be Influenced by an External Electric Field?
Authors: Ramanan Rajeev , Waheed Sodiq O. , Schofield Christopher J. , Christov Christo Z.
Published: May 2021

Arginine methylation is an important mechanism of epigenetic regulation. Some Fe(II) and 2‐oxoglutarate dependent Jumonji‐C (JmjC) Nϵ‐methyl lysine histone demethylases also have N‐methyl arginine demethylase activity. We report combined molecular dynamic (MD) and Quantum Mechanical/Molecular Mechanical (QM/MM) studies on the mechanism of N‐methyl arginine demethylation by human KDM4E and compare the results with those reported for N‐methyl lysine demethylation by KDM4A. At the KDM4E active site, Glu191, Asn291, and Ser197 form a conserved scaffold that restricts substrate dynamics; substrate binding is also mediated by an out of active site hydrogen‐bond between the substrate Ser1 and Tyr178. The calculations imply that in either C−H or N−H potential bond cleaving pathways for hydrogen atom transfer (HAT) during N‐methyl arginine demethylation, electron transfer occurs via a σ‐channel; the transition state for the N−H pathway is ∼10 kcal/mol higher than for the C−H pathway due to the higher bond dissociation energy of the N−H bond. The results of applying external electric fields (EEFs) reveal EEFs with positive field strengths parallel to the Fe=O bond have a significant barrier‐lowering effect on the C−H pathway, by contrast, such EEFs inhibit the N−H activation rate. The overall results imply that KDM4 catalyzed N‐methyl arginine demethylation and N‐methyl lysine demethylation occur via similar C−H abstraction and rebound mechanisms leading to methyl group hydroxylation, though there are differences in the interactions leading to productive binding of intermediates.
Simple amino silyl ether organocatalyst for asymmetric hetero Diels–Alder reaction of isatins with enones
Authors: Parasuraman Perumalsamy , Ganesan Divakar , Begum Zubeda , Seki Chigusa , Okuyama Yuko , Kwon Eunsang , Uwai Koji , Tokiwa Michio , Tokiwa Suguru , Takeshita Mitsuhiro , Nakano Hiroto
Published: May 2021

New two catalysts component system comprising of a primary β‐amino silyl ethers as an organocatalyst and N‐protected amino acids as a co‐catalyst put together worked as an efficient organocatalyst system in the hetero Diels–Alder reaction of isatins with enones affording the chiral spirooxindole‐tetrahydropyranones in good chemical yields and stereoselectivities (up to 94%, up to dr 78:22., up to 85% ee).
Thermokinetic study of macadamia carpel pyrolysis using thermogravimetric analysis
Authors: Moreira Kelly C. C. S. R. , Xavier Thiago P. , de Araújo Jesuína C. S. , dos Santos Kássia G. , de Lira Taisa S.
Published: May 2021

The macadamia productive process generates a large amount of waste, such as walnut carpel, that is improperly disposed of in most instances. This residue is a promising feedstock for biofuel production and it can be converted through thermochemical routes. Liquid pyrolysis products obtained contain a bio‐oil with great potential for the production of fuels and fine chemicals. The goal of this study was to characterize the macadamia carpel for the first time by ultimate, proximate, FTIR, and TG analysis, as well as HHV determination, which showed this is a potential candidate for thermochemical conversion processes. Thermodynamic and kinetic pyrolysis behaviours were evaluated using Ozawa, Kissinger, Starink, and KAS isoconversional models (140.12, 137.69, 137.41, and 146.63 kJ mol−1, respectively), which attested to the product favourability and the operational viability. Additionally, the master plot method was applied to complete the kinetic description, which identified diffusion and nucleation mechanisms during the carpel degradation. After 50% conversion, the third‐order reaction mechanism occurred due to a predominant lignin decomposition. The results showed that the macadamia carpel properties are similar to traditional feedstock, that it may be decomposed into bio‐oil, and that it can be used as an alternative energy source or bio‐chemicals precursor.
Is water saturation a fracability indicator for organic‐rich, yet low‐clay content, tight carbonate source rock reservoirs?
Authors: Liu Hui‐Hai , Zhang Jilin , Liang Feng , Basri Mustafa , Temizel Cenk , Mesdour Rabah
Published: May 2021

Hydraulically fracturing long horizontal wells is the key technology for economically producing hydrocarbon from unconventional reservoirs. A reservoir's fracability (the ease by which it can be hydraulically fractured) has often been used as an important parameter for identifying the sweet spots for production. Several fracability indicators, based on different types of rock properties, including mechanical, geochemical, and mineralogical properties, have been developed and used in industry. This study, based on observations from a source rock reservoir, proposes the use of reservoir water saturation as a new fracability indicator for organic‐rich tight carbonate source rocks that are not clay rich. The results from a machine learning model trained with the observations clearly show the strong and positive correlation between the linear flow parameter (that is obtained based on the newly proposed equivalent‐state approximation and characterizes the effectiveness of hydraulic fracturing) and the water saturation for oil wells, but not for gas wells. While further investigation is needed, the results may be due to the dual wettability of the carbonate source rock. Since minerals are more water‐wet than the organic matter, reservoir water tends to occupy pore spaces in the mineral matrix. Thus, water saturation reflects the relative portion of mineral matrix pore spaces. Given that the low‐clay content mineral matrix contains all the brittle components, the pore‐space development in the mineral matrix may have important implications for the fracability in the hydraulic fracturing process.
Listening to the experts: Parents' perspectives around infection risk and returning to education and social activities following their child's diagnosis of acute lymphoblastic leukemia
Authors: Ballantine Kirsten , Gooder Claire , Ryan Elizabeth , Macfarlane Scott
Published: May 2021

Background

During a child's prolonged treatment for acute lymphoblastic leukemia (ALL), there is a need to balance their increased risk of developing infection‐related complications with meeting their educational and social needs.

Aims

To determine the safe timing of return to social activities for children undergoing treatment for ALL and to determine how parents perceive and act on advice related to infection risk while navigating their child's “return to normal.”

Methods and results

Medical and educational attendance records were reviewed for 47 children who were diagnosed with ALL and 24 semi‐structured qualitative interviews were conducted with a representative sample of their parents. The majority of children (69%) did not return to education prior to the start of maintenance therapy regardless of the advice that the families received from their healthcare team. Those who returned earlier were at no greater risk of major infection complications (mean = 0.5) than those who did not return until after commencing maintenance (mean = 0.4, P = .74). Parents spoke of the difficulty in obtaining practical, consistent, and timely advice and of balancing infection risk with a desire to return to normalcy. Inconsistent advice and constant vigilance placed a burden on parents which often profoundly affected their mental wellbeing. Overall, parents wanted to make their own decisions about how and when their child returned to education and social activities. They made these decisions based on many factors, of which infection risk was just one.

Conclusion

Following the study conclusion, a national working group was established—including parent representatives—to implement the study recommendations. This includes the development of a range of practical resources to better support families. Health professional guidelines provide quantitative data pertaining to infection risk, while emphasizing that the returning decisions ultimately rest with the families. This research demonstrates that listening to parents—who are the experts through their lived experiences—is a critical element in creating policies that are responsive, meaningful, and widely accepted.
HAFTA: Highly adaptive fault‐tolerant routing algorithm for two‐dimensional network‐on‐chips
Authors: Ipek Anil , Tosun Suleyman , Ozdemir Suat
Published: May 2021

Learning‐based routing algorithms are good candidates for two‐dimensional Network‐on‐Chip (NoC) architectures since they can give good path selection decisions by combining current and past state of the network traffic. On the other hand, they generally send packets through nonminimal paths in order to detour congested areas in an attempt to minimize the communication cost. Since adapting to the traffic changes takes time to gather enough feedback information by the applied learning model, non‐minimal paths may take more time than the congested minimal paths. In this work, we incorporate a probabilistic method to a Q‐learning‐based NoC routing algorithm for selecting a minimal or nonminimal path to minimize the negative effect of learning duration. We also consider the errors in the architecture and propose a fault‐tolerance mechanism that detects both transient and permanent link errors. We compared our method against a standard Q‐learning‐based routing algorithm on several traffic models in terms of throughput and latency. The results show that our method outperforms its counterpart up to 30% in latency and 7% in throughput.
Non‐linear behaviour of electron acoustic wave dynamics in a magnetized plasma with non‐thermal hot electrons
Authors: Maity Rabindranath , Sahu Biswajit , Poria Swarup
Published: May 2021

Non‐linear dynamical behaviour of electron acoustic waves (EAWs) is studied in a magnetized non‐thermal plasma (containing inertial cold electrons, inertialess hot electrons following non‐thermal distribution function, and static ions) via a fluid dynamical approach. A linear dispersion relation is derived and the propagation of two possible modes and their evolution are studied through the different plasma configuration parameters, such as non‐thermality and external magnetic field strength. In a non‐linear perturbation regime, a reductive perturbation technique is employed to derive the non‐linear evolution equation and the analysis is executed for travelling plane waves in terms of a non‐linear dynamical system to enlighten the numerous aspects of the phase space dynamics. The results of numerical simulation predict the existence of a wide class of non‐linear structures, namely solitonic, periodic, quasiperiodic, and chaotic depending upon different controlling plasma parameters. Also, Poincaré return map analysis confirms these non‐linear structures of the EAWs.
Multiple‐access interference suppression in massive multiple‐input multiple‐output‐non‐orthogonal multiple access based on space–time block coding
Authors: Akbarian Behnam , Ghazi‐Maghrebi Saeed
Published: May 2021

Non‐orthogonal multiple‐access (NOMA) scheme using massive multiple‐input multiple‐output (MIMO) transmission suffers from interference between users. In this paper, we propose a novel MIMO‐NOMA framework based on space–time block code (STBC) to decrease the multiple‐access interference (MAI), when the number of users is increasing. In this paper, besides giving an analysis of network, cluster, group, and users, we first present the system model. Then, an efficient precoder and detector are designed based on interference analysis. In particular, the proposed scheme can decompose a massive MIMO‐NOMA system into multiple separated single‐input single‐output NOMA channels. Also, analytical results are developed to evaluate the performance of the system. To address the dramatic increment of power level, with the aid of the proposed algorithm, the optimal solution is achieved. Mathematical analyses for both MIMO‐NOMA and STBC are presented to design efficient precoding and detection. Finally, simulation results, based on STBC, are provided to verify the theoretical analysis to demonstrate significant capacity improvements of the massive MIMO‐NOMA.
Challenges of peptide and protein drug delivery by oral route: Current strategies to improve the bioavailability
Authors: Verma Saurabh , Goand Umesh K. , Husain Athar , Katekar Roshan A. , Garg Richa , Gayen Jiaur R.
Published: May 2021

Advancement in biotechnology provided a notable expansion of peptide and protein therapeutics, used as antigens, vaccines, hormones. It has a prodigious potential to treat a broad spectrum of diseases such as cancer, metabolic disorders, bone disorders, and so forth. Protein and peptide therapeutics are administered parenterally due to their poor bioavailability and stability, restricting their use. Hence, research focuses on the oral delivery of peptides and proteins for the ease of self‐administration. In the present review, we first address the main obstacles in the oral delivery system in addition to approaches used to enhance the stability and bioavailability of peptide/protein. We describe the physiochemical parameters of the peptides and proteins influencing bioavailability in the systemic circulation. It encounters, many barriers affecting its stability, such as poor cellular membrane permeability at the GIT site, enzymatic degradation (various proteases), and first‐pass hepatic metabolism. Then describe the current approaches to overcome the challenges mentioned above by the use of absorption enhancers or carriers, structural modification, formulation and advance technology.
Human activity influences wildlife populations and activity patterns: implications for spatial and temporal refuges
Authors: Lewis Jesse S. , Spaulding Susan , Swanson Heather , Keeley William , Gramza Ashley R. , VandeWoude Sue , Crooks Kevin R.
Published: May 2021

Human activity affects plant and animal populations across local to global scales, and the management of recreation areas often aims to reduce such impacts. Specifically, by understanding patterns of human activity and its influence on animal populations, parks and recreation areas can be managed to provide spatial and temporal refuge to wildlife most sensitive to this type of human disturbance. However, additional research is necessary to understand how human activity influences wildlife populations, habitat use, and activity patterns for a diversity of wildlife species. We studied the potential impacts of human activity (as measured by nonmotorized recreationists) on populations and activity patterns of 12 mammal species, including herbivores and carnivores, from 63 motion‐activated cameras that sampled game trails and human trails with varying degrees of human activity along the Front Range of Colorado. Human activity was greatest during the day and minimal or absent during the night. All wildlife species in our study used human trails, although the extent to which human recreation altered the occupancy, relative habitat use, and activity patterns of wildlife varied across species, where some animals appeared to be more influenced by human activity than others. Some species (e.g., fox squirrel, red fox, and striped skunk) did not demonstrate a response to human activity. Other species (e.g., black bear, coyote, and mule deer) altered their activity patterns on recreation trails to be more active at night. Across all wildlife, the degree to which animals altered activity patterns on human trails was related to their natural activity patterns and how active they were during the day when human activity was greatest; species that exhibited greater overlap in natural activity patterns with humans demonstrated the greatest shifts in their activity, often exhibiting increased nocturnal activity. Further, some species (e.g., Abert’s squirrel, bobcat, and mountain lion) exhibited reduced occupancy and/or habitat use in response to human recreation. Managing spatial and temporal refuges for wildlife would likely reduce the impacts of human recreation on animals that use habitat in proximity to trail networks.
Forest restoration increases isolated wetland hydroperiod: a long‐term case study
Authors: Golladay S. W. , Clayton B. A. , Brantley S. T. , Smith C. R. , Qi J. , Hicks D. W.
Published: May 2021

Geographically isolated wetlands (GIWs) are well known as “hotspots” for biodiversity and other ecosystem services, making their value on landscapes disproportionate to the area they occupy. GIWs are dependent on regular cycles of inundation and drying, which makes hydrology a primary controlling variable for sustaining functions and associated ecosystem services. Although human activity has degraded GIWs in many regions, relatively little work has focused on upland management as a way of sustaining, or even improving, GIW structure and function. We present a case study of longleaf pine forest restoration, by hardwood removal, on the characteristics of a wetland hydroperiod over a 10‐year study. Our study wetland, W‐51, is 0.89 ha with a catchment area of 31.2 ha located on a ~11,400‐ha private preserve in Baker County, Georgia (31.250° N, 84.495° W). Beginning in 2006, continuous water level and climate data were recorded in the wetland and adjacent well transects across the wetland catchment. In autumn 2009, hardwoods were removed or deadened in the catchment resulting in a 37% reduction in tree cover. The effects on the hydrologic system were measured through 2016 by examining pre‐ and post‐removal water levels, water yield ecosystem (WYe), and standardized recession rates (RRstd). The study included periods of above and below normal rainfall. Generally, wetland hydroperiods began in December and ended in May, but varied with rainfall pattern and amount. Hardwood removal increased WYe and decreased RRstd resulting in greater catchment water availability as reflected in water levels. Hardwood removal affected both the ascending and recessing limbs of wetland hydroperiods, substantially increasing the availability of ponded water in the wetland. Our results quantify changes in wetland hydrologic characteristics associated with forest management activities, which appear to have reduced forest water demand. Our study was a management case study, limited in scope but conducted in a realistic setting. More extensive studies (paired, replicated designs) are needed to better understand the implications at both the local scale, that is, managing critical aquatic habitat for wildlife populations, and at the regional scale, that is, providing support for landscape‐scale connectivity and water yields.
Progress of Pb‐Sn Mixed Perovskites for Photovoltaics: A Review
Authors: Bandara Rajapakshe Mudiyanselage Indrachapa , Silva Shashini M. , Underwood Cameron C. L. , Jayawardena K. D. G. Imalka , Sporea Radu A. , Silva S. Ravi P.
Published: May 2021

Pb‐Sn mixed perovskites are becoming increasingly popular as narrow‐bandgap (1.2–1.3 eV) light absorbers in single‐junction perovskite solar cells (PSCs) and as bottom cells for all‐perovskite tandem solar cells, for high‐efficiency, low‐cost, lightweight, roll‐to‐roll printable photovoltaic (PV) applications. From the first report of planar Pb:Sn mixed PSCs in 2014, the power conversion efficiencies (PCE) have increased from 10% to 21% by the end of 2020 with an exponential growth in research conducted in this field. Despite much effort, the performance and stability of Pb‐Sn mixed PSCs are still limited, which constrains their long‐term use in all‐perovskite tandem devices. This review highlights the avenues explored in improving different aspects of Pb‐Sn mixed PSCs and provides a comprehensive discussion of the interdependent factors affecting the device performance. This includes compositional engineering of the perovskite crystal, absorber layer fabrication and crystallization methods, bandgap tuning, Sn4+ reduction, and surface passivation of the absorber layer, as well as the selection of interlayers and electrodes of the final PSC.
Total Synthesis of (−)‐4‐epi‐Englerin A
Authors: Kumar Palli Kishore , Reddy Anugu Raghunath , Chandrasekhar Srivari
Published: May 2021

The synthesis of (−)‐4‐epi‐Englerin A, the epimer of natural product (−)‐Englerin A, a sesquiterpenoid with exceptional anti‐proliferative activity in renal cancer cells is achieved from (R)‐(+)‐limonene. Key features of the synthesis are Sharpless asymmetric dihydroxylation, aldol reaction, and transannular epoxide opening reactions to install the required functionalities of oxabridged tricyclic core.
Facies architecture and depositional model for a fine‐grained hybrid‐energy delta: An example from the Upper Cambrian to Lower Ordovician Barik Formation, Central Oman
Authors: Shelukhina Olga I. , El‐Ghali Mohamed A. K. , Abbasi Iftikhar Ahmed , Khan Junaid Ahmed , Khalifa Mohamed Kh. , Rajendran Sankaran , Al‐Sayigh Abdulrazak
Published: May 2021

Recognizing ancient deltas' depositional architecture is challenging due to the complex interplay of the fluvial, waves, and tidal processes. The integration of field‐based sedimentological and trace fossils studies of the Late Cambrian‐Early Ordovician Barik Formation in Central Oman allowed better identification of different lithofacies architectures and depositional process signatures. The Barik Formation is a major tight‐gas reservoir in the Oman Sedimentary Basins, where it is over 800‐m thick. The only outcrop analogue is in the Qarn Mahatta Humaid area, where ca. 50‐m thickness of the formation is exposed and extends laterally over 5 km. This study revealed the presence of four lithofacies associations, including (a) mouth bar/shoreface, (b) tidal flat, (c) tidal channel, and (d) delta distributary channels using 12 logged sections. The depositional features identified in the field include tidal, wave/storm, and fluvial. The tidal signatures are represented by mud‐drapes, large‐scale reactivation surfaces, sigmoidal cross‐bedding, and climbing and flaser bedding, predominantly in the mixed mud‐sand tidal flats of the lower delta plain and delta distributary channels of the upper to lower delta plains. The wave/storm signatures are represented by wave ripples and small‐scale hummocky cross‐stratification in the mouth bar/shoreface of the delta front platform. The fluvial and subaerial signatures are represented by the occurrence of the scour surfaces with lag deposits of channel‐fill and the development of desiccation mud‐cracks. The Barik Formation delta sandstones form amalgamated sheet‐like bodies prograding to the north‐northeast and deposited along a ramp‐type low relief basin. This prograding delta represents a highstand system tract. This study presents an example of the ancient fine‐grained hybrid‐energy prograding delta, where fluvial processes operated beside the tidal and wave/storm processes over a broad and low relief shelf in a vegetation‐free system.
Enhanced detection of cortical atrophy in Alzheimer's disease using structural MRI with anatomically constrained longitudinal registration
Authors: Iannopollo Emily , Garcia Kara ,   Alzheimer' Disease Neuroimaging Initiative
Published: May 2021

Cortical atrophy is a defining feature of Alzheimer's disease (AD), often detectable before symptoms arise. In surface‐based analyses, studies have commonly focused on cortical thinning while overlooking the impact of loss in surface area. To capture the impact of both cortical thinning and surface area loss, we used anatomically constrained Multimodal Surface Matching (aMSM), a recently developed tool for mapping change in surface area. We examined cortical atrophy over 2 years in cognitively normal subjects and subjects with diagnoses of stable mild cognitive impairment, mild cognitive impairment that converted to AD, and AD. Magnetic resonance imaging scans were segmented and registered to a common atlas using previously described techniques (FreeSurfer and ciftify), then longitudinally registered with aMSM. Changes in cortical thickness, surface area, and volume were mapped within each diagnostic group, and groups were compared statistically. Changes in thickness and surface area detected atrophy at similar levels of significance, though regions of atrophy somewhat differed. Furthermore, we found that surface area maps offered greater consistency across scanners (3.0 vs. 1.5 T). Comparisons to the FreeSurfer longitudinal pipeline and parcellation‐based (region‐of‐interest) analysis suggest that aMSM may allow more robust detection of atrophy, particularly in earlier disease stages and using smaller sample sizes.
A study on entropy generation and heat transfer in a magnetohydrodynamic flow of a couple‐stress fluid through a thermal nonequilibrium vertical porous channel
Authors: Siddabasappa C. , Siddheshwar P. G. , Makinde O. D.
Published: May 2021

The effect of local thermal nonequilibrium (LTNE) on the entropy generation and heat transfer characteristics in the magnetohydrodynamic flow of a couple‐stress fluid through a high‐porosity vertical channel is studied numerically using the higher‐order Galerkin technique. The Boussinesq approximation is assumed to be valid and the porous medium is considered to be isotropic and homogeneous. Two energy equations are considered one each for solid and fluid phases. The term involving the heat transfer coefficient in both equations renders them mutually coupled. Thermal radiation and an internal heat source are considered only in the fluid phase. The influence of inverse Darcy number, Hartmann number, couple‐stress fluid parameter, Grashof number, thermal radiation parameter, and interphase heat transfer coefficient on velocity and temperature profiles is depicted graphically and discussed. The entropy generation, friction factor, and Nusselt number are determined, and outcomes are presented via plots. The effect of LTNE on the temperature profile is found to cease when the value of the interphase heat transfer coefficient is high, and in this case, we get the temperature profiles of fluid and solid phases are uniform. The physical significance of LTNE is discussed in detail for different parameters' values. It is found that heat transport and friction drag are maximum in the case of LTNE and minimum in the case of local thermal equilibrium. We observe that LTNE opposes the irreversibility of the system. The corresponding results of a fluid‐saturated densely packed porous medium can be obtained as a limiting case of the current study.
Structure–property relationship of coplanar binary nitrogen‐rich fused ring using theoretical calculation
Authors: Jiang Yuhe , Luo Yuqin , Liu Jia , Zhang Lu , Wu Jinting , Li Hongbo , Zhang Jianguo
Published: May 2021

The search for coplanar high‐energy insensitive explosives is a new direction in the research of energetic materials. A series of coplanar compounds based on the [1,2,4]triazolo[4,3‐b][1,2,4]triazine skeleton (ATTZ) were designed and studied using density functional theory. The research content includes density, detonation performance, shock sensitivity, bond‐dissociation energy, thermodynamic properties, and electrostatic potential. The formation of intramolecular hydrogen bonds between the energetic groups connected by these coplanar compounds and the introduction of coordinated oxygen on the parent to improve detonation performance are the highlights of this study. The results show that most of the compounds have good density, low sensitivity, and excellent detonation performance. And compound A11 shows a high density (d = 1.93 g/cm3), detonation velocity (D = 9.12 km/s1), and explosion pressure (P = 38.41 GPa), with the bond dissociation energy value of 253.4 kJ/mol. Designing coplanar compounds is an efficient approach to explore high‐energy insensitive explosives.
Selective oligomerization of isobutylene in mixed C4 catalyzed by supported Fe(NO3)3/β catalyst
Authors: Sun Dahai , Liu Shuai , Yu Fangyu , Tian Hui , Zhao Qi
Published: May 2021

BACKGROUND

Methyl tert‐butyl ether (referred to as MTBE) is harmful to the environment and hence its use is limited in China. To avoid the waste of isobutylene as MTBE raw material and improve the utilization rate of isobutylene in mixed C4 fraction, supported Fe(NO3)3/β molecular sieve catalysts with different active components were prepared by the equal volume impregnation method. The catalysts were analyzed by X‐ray diffraction (XRD), Thermogravimetric analysis (TG), Temperature programmed desorption of NH3, Brunauer–Emmett–Teller analysis and scanning electron microscopy, and the catalytic performance of catalysts with mixed C4 fractions as raw materials and different active component loadings for selective oligomerization of isobutylene was investigated in a fixed bed reactor.

RESULTS

The results show that the catalyst has the best catalytic performance when the active component loading was 6%, the reaction temperature was 60 °C, the reaction pressure was 1 MPa and the reaction space velocity was 1.5 h−1.

CONCLUSION

The conversion rate of isobutylene was >90%, the selectivity of C8 olefin was ≈80% and there was almost no loss of n‐butene. © 2021 Society of Chemical Industry (SCI).
Microlenses arrays: Fabrication, materials, and applications
Authors: Cai Shuxiang , Sun Yalin , Chu Honghui , Yang Wenguang , Yu Haibo , Liu Lianqing
Published: May 2021

Microlenses have become an indispensable optical element in many optical systems. The advancement of technology has led to a wider variety of microlenses fabrication methods, but these methods suffer from, more or less, some limitations. In this article, we review the manufacturing technology of microlenses from the direct and indirect perspectives. First, we present several fabrication methods and their advantages and disadvantages are discussed. Then, we discuss the commonly used materials for fabricating microlenses and the applications of microlenses in various fields. Finally, we point out the prospects for the future development of microlenses and their fabrication methods.