bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the contributions of nitrogen mineralization to yield of corn
Authors: White Charles M. , Finney Denise M. , Kemanian Armen R. , Kaye Jason P.
Published: September 2020

Nitrogen (N) mineralized from soil organic matter (SOM) and crop residues is an important source of N to crop nutrition but historically has been difficult to account for in N fertilizer recommendation systems. Here we propose and test relatively simple biogeochemical models that predict the contribution of N mineralization in supporting the yield of corn (Zea mays L.). The models are specifically designed to use soil and cover crop measurements that are easily accessible to farmers and agronomists, including soil carbon (C) concentration, 24‐h CO2 respiration of a dried and rewetted soil sample, soil texture, and cover crop biomass N content and C/N ratio. We calibrated the models to explain variation of and predict unfertilized corn yield using a dataset of 73 observations compiled from nine experiments conducted in different sites and growing seasons in Pennsylvania. A model using soil C to calculate contributions of SOM mineralization to N supply predicted unfertilized corn yields more accurately than a model using the 24‐h CO2 respiration (r2 = .62 vs. .47; RMSE = 1.58 vs. 1.87 Mg ha−1, respectively). Soil sand content played an important role in the models by regulating the humification efficiency, a term that partitions decomposing C and N between microbially assimilated and mineralized pools. These models are prototypes for a new generation of N decision support tools that answer many of the shortcomings of current N fertilizer recommendation systems and offer a novel step forward in N fertility management.
Generalized initialization for the dynamic simulation and optimization of grade transition processes using two‐dimensional collocation
Authors: Lin Xiaowen , Chen Xi , Biegler Lorenz T.
Published: September 2020

Optimization modeling tools are essential to determine optimal design specifications and operation conditions of polymerization processes, especially when quality indices based on molecular weight distributions (MWDs) must be enforced. This study proposes a generalized MWD‐based optimization strategy using orthogonal collocation in two dimensions, which can capture the dynamic features of MWDs accurately. To enable the strategy, this study considers generalized initialization methods for large‐scale simulation and optimization. Here, a homotopy method based on intermediate solutions is adopted to generate initial values for general steady‐state simulation models, starting from an arbitrary known solution for any steady‐state simulation model. For dynamic simulation models, the response of a first‐order linear system is adopted to initialize the state variables. Case studies show the effectiveness of this procedure to enable systematic, reliable, and efficient solution of the optimization problem.
Foraging behavior and pollination efficiency of generalist insects in an understory dioecious shrubHelwingia japonica
Authors: Wu Ting , Tang Ju , Huang Shuang‐Quan
Published: September 2020

Premise

It has been hypothesized that pollination success in animal‐pollinated dioecious plants relies on opportunistic pollinators with no discrimination against female flowers. However, empirical studies of pollinator foraging behavior and pollination effectiveness in dioecious species are few.

Methods

To investigate potential pollinators inHelwingia japonica, a dioecious shrub with small, inconspicuous flowers, we compared floral visitors and visit frequency to female and male plants for three flowering seasons in two field populations in subtropical forests in southwest China. Pollen placement on the insect bodies of four groups (solitary bees and other bees, fungus gnats, and other flies) was compared, and insect foraging behavior was observed. Pollen removal and conspecific and heterospecific pollen deposition per visit were measured to compare pollination effectiveness among the four groups.

Results

Floral visitors usually did not discriminate between male and female flowers and did not gather pollen into collections. Our measurements of pollen transfer efficiency showed that solitary bees were the most effective pollinators with the highest conspecific pollen deposition. These insects seemed to be opportunistic visitors because pollen grains ofH. japonicawere distributed evenly over different regions of the visitor’s body, and heterospecific pollen accounted for over 50% of total pollen loads on stigmas in the two populations.

Conclusions

Our investigations indicated that potential pollinators were generalists and did not discriminate against female flowers, as predicted for dioecious species pollinated by insects. A perspective of pollen removal by floral visitors offers insights into the evolution of plant sexual systems.
On characterizing root function in perennial horticultural crops
Authors: Lavely Emily K. , Chen Weile , Peterson K. Aysha , Klodd Annie E. , Volder Astrid , Marini Richard P. , Eissenstat David M.
Published: September 2020

Premise

While root‐order approaches to fine‐root classification have shown wide utility among wild plants, they have seen limited use for perennial crop plants. Moreover, inadequate characterization of fine roots across species of domesticated perennial crops has led to a knowledge gap in the understanding of evolutionary and functional patterns associated with different fine‐root orders.

Methods

We examined fine‐root traits of common horticultural fruit and nut crops:Malus×domestica,Prunus persica,Vitus vinifera,Prunus dulcis, andCitrus×clementina. Additional roots were sampled from 33 common perennial horticultural crops, native to tropical, subtropical, and temperate regions, to examine variation in 1st‐ and 2nd‐order absorptive roots.

Results

First‐order roots of grape and 1st‐ and 2nd‐order roots of apple and peach were consistently thin, nonwoody, mycorrhizal, and had high N:C ratios. In contrast, 4th‐ and 5th‐order roots of grape and 5th‐order roots of apple and peach were woody, nonmycorrhizal, had low N:C ratios, and were thicker than lower‐order roots. Among the 33 horticultural species, diameter of 1st‐ and 2nd‐order roots varied about 15‐fold, ranging from 0.04 to 0.60 mm and 0.05 to 0.89 mm respectively. This variation generally was phylogenetically conserved across plant lineages.

Conclusions

Collectively, our research shows that root‐order characterization has considerably more utility than an arbitrary diameter cutoff for identifying roots of different functions in perennial horticultural crops. In addition, much of the variation in root diameter among species can be predicted by evolutionary relationships.
Youth Participatory Approaches and Health Equity: Conceptualization and Integrative Review
Authors: Ozer Emily J. , Abraczinskas Michelle , Duarte Catherine , Mathur Ruchika , Ballard Parissa Jahromi , Gibbs Lisa , Olivas Elijah T. , Bewa Marlene Joannie , Afifi Rima
Published: September 2020

There is an array of youth participatory approaches relevant to health equity efforts in community psychology, adolescent health, youth development, and education. While they share some commonalities, they also reflect important distinctions regarding key processes and intended level of impact. Here, we consider the following: (a) youth‐led participatory action research (YPAR), (b) youth organizing (YO), (c) youth‐led planning, (d) human‐centered design, (e) participatory arts, and (f) youth advisory boards. Informed by community psychology theories on empowerment and levels of change and social epidemiology frameworks that focus on the social determinants of health inequities, we aim to promote greater clarity in the conceptualization, implementation, and evaluation of youth participatory approaches; frame the “landscape” of youth participatory approaches and their similarities and differences; present an integrative review of the evidence regarding the impact of youth participatory approaches; and describe several illustrative cases so as to consider more deeply how some youth participatory approaches aim to influence the social determinants of health that lead to the physical embodiment of health inequities. We conclude by identifying areas of future policy‐ and practice‐relevant research for advancing youth participation and health equity.
Association between blood lead level during pregnancy and birth weight: A meta‐analysis
Authors: Wang Duo , Fu Xi , Zhang Jun , Xu Chengfang , Hu Qiansheng , Lin Weiwei
Published: September 2020

Background

We aimed to provide a quantitative summary of evidence for a relationship between prenatal lead (Pb) exposure and birth weight.

Methods

PubMed and Web of Science databases were searched for eligible epidemiological studies. We transformed findings in eligible studies with different effect‐size metrics to standardized regression coefficients, and used fixed‐effects or random‐effects models to assess the pooled effects of prenatal Pb exposure on birth weight.

Results

There was a significant negative association between prenatal Pb exposure and birth weight. Birth weight reduction was associated with elevated lead levels in maternal blood (β = −0.094; 95% confidence interval [CI]: −0.157 to −0.030) and cord blood (β = −0.120; 95% CI: −0.239 to −0.001).

Conclusions

This meta‐analysis is the first to provide a quantitative assessment of Pb exposure during pregnancy and an increased risk of lower birth weight.
The first familial case of inherited intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA) with a novel FBXO11 variant
Authors: Lee Cha Gon , Seol Chang Ahn , Ki Chang‐Seok
Published: September 2020

Intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA) caused by germline de novo variants in FBXO11 was recently recognized as a novel intellectual disability (ID) syndrome through reverse phenotyping after whole‐exome sequencing (WES). Fewer than 50 disease‐causing de novo FBXO11 variants in IDDFBA are reported thus far. Here, we present the first report of a family showing autosomal dominantly inherited IDDFBA, harboring a novel heterozygous variant in FBXO11 (c.2401_2405dup;p. Gly803Leufs*6) identified by WES. In this family, the mother and two daughters showed mild ID and mild facial dysmorphism. This finding is expected to increase our understanding of the genotype–phenotype of IDDFBA and to facilitate genetic counseling for the disorder caused by FBXO11.
Recurrent constellations of embryonic malformations re‐conceptualized as an overlapping group of disorders with shared pathogenesis
Authors: Adam Aaron P. , Curry Cynthia J. , Hall Judith G. , Keppler‐Noreuil Kim M. , Adam Margaret P. , Dobyns William B.
Published: September 2020

Several recurrent malformation associations affecting the development of the embryo have been described in which a genetic etiology has not been found, including LBWC, MURCS, OAVS, OEIS, POC, VACTERL, referred to here as “recurrent constellations of embryonic malformations” (RCEM). All are characterized by an excess of reported monozygotic discordant twins and lack of familial recurrence. We performed a comprehensive review of published twin data across all six phenotypes to allow a more robust assessment of the association with twinning and potential embryologic timing of a disruptive event. We recorded the type of twinning, any overlapping features of another RCEM, maternal characteristics, and the use of ART. Statistically significant associations included an excess of monozygotic twins and 80% discordance rate for the phenotype across all twins. There was an 18.5% rate of ART and no consistently reported maternal adverse events during pregnancy. We found 24 instances of co‐occurrence of two RCEM, suggesting a shared pathogenesis across all RCEM phenotypes. We hypothesize the following timing for RCEM phenotypes from the earliest perturbation in development to the latest: LBWC, POC, OEIS, VACTERL, OAVS, then MURCS. The RCEM group of conditions should be considered a spectrum that could be studied as a group.
A diagnostic approach to syndromic retinal dystrophies with intellectual disability
Authors: Yang Xiao‐Ru , Benson Matthew D. , MacDonald Ian M. , Innes A. Micheil
Published: September 2020

Inherited retinal dystrophies are a group of monogenic disorders that, as a whole, contribute significantly to the burden of ocular disease in both pediatric and adult patients. In their syndromic forms, retinal dystrophies can be observed in association with intellectual disability, frequently alongside other systemic manifestations. There are now over 80 genes implicated in syndromic retinal dystrophies with intellectual disability. Identifying and accurately characterizing these disorders allows the clinician to narrow the differential diagnosis, evaluate for relevant associated features, arrive at a timely and accurate diagnosis, and address both sight‐threatening ocular manifestations and morbidity‐causing systemic manifestations. The co‐occurrence of retinal dystrophy and intellectual disability in an individual can be challenging to investigate, diagnose, and counsel given the considerable phenotypic and genotypic heterogeneity that exists within this broad group of disorders. We performed a review of the current literature and propose an algorithm to facilitate the evaluation, and clinical and mechanistic classification, of these individuals.
A HClO4‐Catalyzed Substitutive Phosphorylation of Anthracene‐9‐ols with P(O)−H Compounds to Phosphorylated 9,10‐Dihydroanthracenes
Authors: Zou Yun‐Xiang , Ni Hai‐Liang , Dong Hong‐Bo , Yang Xin‐Yue , Chen Long
Published: September 2020

A highly efficient HClO4 catalysed substitutive phosphorylation of S‐, O‐ and N‐based anthracene‐9‐ols with P(O)−H species has been developed to afford phosphorylated 9,10‐dihydroanthracenes with a tetra‐ or trisubstituted carbon centre in good to excellent yields, which serves as a good complement to the established protocols that are limited to tertiary phosphorylated 9,10‐dihydroanthracenes. Gram‐scale synthesis and further elaboration highlight its synthetic utility.
External Reductant‐free Stepwise [3+2] Cycloaddition/Reductive Cyclization from 2‐Nitrochalcones and Isocyanides: Synthesis of Pyrrolo[3,4‐c]quinoline N‐oxides
Authors: Sheng Xinyao , Xu Qi , Lin Ziwen , Hu Zhongyan , Pan Ling , Liu Qun , Li Yifei
Published: September 2020

A novel and unprecedented route for the synthesis of pyrrolo[3,4‐c]quinoline N‐oxides is described. The synthetic approach involves a stepwise [3+2] cycloaddition/reductive cyclization from readily available 2‐nitrochalcones and activated methylene isocyanides. The unique feature of this transformation is the reductive cyclization of C−N bond forming without any external reductants. Moreover, the application of pyrrolo[3,4‐c]quinoline N‐oxides is realized to formed pyrrolo[3,4‐c]quinoline derivatives.
Analysis of Assumptions in BIG Bell Test Experiments
Authors: Sołtan Stanisław , Dopierała Dawid , Bednorz Adam
Published: September 2020

Recently, a group of experiments tested local realism with random choices prepared by humans. These various tests were subject to additional assumptions, which lead to loopholes in the interpretations of almost all of the experiments. Among these assumptions are fair sampling, no signaling, and faithful reproduction of a Bell‐type quantum model. The data from 9 of 13 experiments were examined and occurring anomalies were analyzed in view of the above assumptions. It is concluded that further tests of local realism need better setup calibration to avoid apparent signaling or necessity of the complicated underlying quantum model.
Site‐Selective Modification of Peptides and Proteins via Interception of Free‐Radical‐Mediated Dechalcogenation
Authors: Griffiths Rhys C. , Smith Frances R. , Long Jed E. , Williams Huw E. L. , Layfield Robert , Mitchell Nicholas J.
Published: September 2020

The development of site‐selective chemistry targeting the canonical amino acids enables the controlled installation of desired functionalities into native peptides and proteins. Such techniques facilitate the development of polypeptide conjugates to advance therapeutics, diagnostics, and fundamental science. We report a versatile and selective method to functionalize peptides and proteins through free‐radical‐mediated dechalcogenation. By exploiting phosphine‐induced homolysis of the C−Se and C−S bonds of selenocysteine and cysteine, respectively, we demonstrate the site‐selective installation of groups appended to a persistent radical trap. The reaction is rapid, operationally simple, and chemoselective. The resulting aminooxy linker is stable under a variety of conditions and selectively cleavable in the presence of a low‐oxidation‐state transition metal. We have explored the full scope of this reaction using complex peptide systems and a recombinantly expressed protein.
Chemie und Begriffe entwickeln sich, aber Phänomene nicht: Von Chalkogen‐Chalkogen‐Wechselwirkungen zu “Chalcogen Bonding”
Authors: Kolb Simon , Oliver Gwyndaf A. , Werz Daniel B.
Published: September 2020

Chalcogen Bonding spielt in verschiedenen Bereichen der Chemie sowohl im Festkörper als auch in Lösung eine entscheidende Rolle. Bei genauer Literaturrecherche wird allerdings deutlich, dass – nachdem sich der Begriff von “Chalkogen‐Chalkogen‐Wechselwirkungen” zum prägnanteren “Chalcogen Bonding” verkürzt hatte – ein Teil der wissenschaftlichen Gemeinschaft sich an die Herkunft dieses Phänomens nicht mehr erinnert und dieses in seiner ursprünglichen Form auch nicht mehr referenziert. In diesem Viewpoint verfolgen wir exemplarisch die wissenschaftliche Entwicklung ausgehend von diesem Phänomen – beginnend mit seiner Entdeckung, über die Abänderung des Begriffs bis zur aktuellen und faszinierenden Forschung in Bereichen wie Crystal Engineering, dem Design supramolekularer Strukturen und der modernen Katalyse.
Mechanism of 3‐Methylglutaconyl CoA Decarboxylase AibA/AibB: Pericyclic Reaction versus Direct Decarboxylation
Authors: Sheng Xiang , Himo Fahmi
Published: September 2020

The enzyme 3‐methylglutaconyl coenzyme A (CoA) decarboxylase (called AibA/AibB) catalyzes the decarboxylation of 3‐methylglutaconyl CoA to generate 3,3‐dimethylacrylyl‐CoA, representing an important step in the biosynthesis of isovaleryl‐coenzyme A in Myxococcus xanthus when the regular pathway is blocked. A novel mechanism involving a pericyclic transition state has previously been proposed for this enzyme, making AibA/AibB unique among decarboxylases. Herein, density functional calculations are used to examine the energetic feasibility of this mechanism. It is shown that the intramolecular pericyclic reaction is associated with a very high energy barrier that is similar to the barrier of the same reaction in the absence of the enzyme. Instead, the calculations show that a direct decarboxylation mechanism has feasible energy barriers that are in line with the experimental observations.
Solid‐State Radical C−H Trifluoromethylation Reactions Using Ball Milling and Piezoelectric Materials
Authors: Pang Yadong , Lee Joo Won , Kubota Koji , Ito Hajime
Published: September 2020

The application of piezoelectricity for the generation of trifluoromethyl (CF3) radicals is reported together with the development of a method for the mechanochemical C−H trifluoromethylation of aromatic compounds. As compared to conventional solution‐based approaches, this mechanoredox C−H trifluoromethylation enables cleaner and more sustainable access to a wide range of trifluoromethylated N‐heterocycles and peptides, which are important structural motifs in modern drug discovery. This study thus represents an important milestone for future applications of mechanoredox systems to medicinal and pharmaceutical science.
Breathing Micelles for Combinatorial Treatment of Rheumatoid Arthritis
Authors: Tao Siyue , Cheng Jian , Su Gai , Li Dan , Shen Zhiqiang , Tao Fenghua , You Tao , Hu Jinming
Published: September 2020

Breathing process involves inhalation and exhalation of different gases in animals. The gas exchange of the breathing process plays a critical role in maintaining the physiological functions of living organisms. Although artificial breathing materials exhibiting volume expansion and contraction upon alternate exposure to different gases have been well explored, those being able to realize the gas exchange remain elusive. Herein, we report breathing micelles (BM) capable of inhaling nitric oxide (NO) and exhaling carbon monoxide (CO), both of which are endogenous gaseous signaling molecules. We demonstrate that BM can simultaneously scavenge overproduced NO and attenuate proinflammatory cytokines in lipopolysaccharide (LPS)‐challenged macrophage cells. In vivo studies revealed that BM outperformed conventional nonsteroidal anti‐inflammatory drugs such as dexamethasone (Dexa) in treatment of rheumatoid arthritis (RA) in adjuvant‐induced arthritis (AIA) rats, likely due to the combinatorial effect of NO depletion, CO‐mediated deactivation of inducible NO synthase (iNOS) and activation of heme oxygenase‐1 (HO‐1). This work provides new insights into artificial BM for potential biomedical applications.
Configurational Entropy Driven High‐Pressure Behaviour of a Flexible Metal–Organic Framework (MOF)
Authors: Vervoorts Pia , Keupp Julian , Schneemann Andreas , Hobday Claire L. , Daisenberger Dominik , Fischer Roland A. , Schmid Rochus , Kieslich Gregor
Published: September 2020

Flexible metal–organic frameworks (MOFs) show large structural flexibility as a function of temperature or (gas)pressure variation, a fascinating property of high technological and scientific relevance. The targeted design of flexible MOFs demands control over the macroscopic thermodynamics as determined by microscopic chemical interactions and remains an open challenge. Herein we apply high‐pressure powder X‐ray diffraction and molecular dynamics simulations to gain insight into the microscopic chemical factors that determine the high‐pressure macroscopic thermodynamics of two flexible pillared‐layer MOFs. For the first time we identify configurational entropy that originates from side‐chain modifications of the linker as the key factor determining the thermodynamics in a flexible MOF. The study shows that configurational entropy is an important yet largely overlooked parameter, providing an intriguing perspective of how to chemically access the underlying free energy landscape in MOFs.
Multispecific Platinum(IV) Complex Deters Breast Cancer via Interposing Inflammation and Immunosuppression as an Inhibitor of COX‐2 and PD‐L1
Authors: Jin Suxing , Muhammad Nafees , Sun Yuewen , Tan Yehong , Yuan Hao , Song Dongfan , Guo Zijian , Wang Xiaoyong
Published: September 2020

Breast cancer (BC) is one of the most common malignancies in women and often accompanied by inflammatory processes. Cyclooxygenase‐2 (COX‐2) plays a vital role in the progression of BC, correlating with the expression of programmed death‐ligand 1 (PD‐L1). Overexpression of PD‐L1 contributes to the immune escape of cancer cells, and its blockade would stimulate anticancer immunity. Two multispecific platinum(IV) complexes DNP and NP were prepared using non‐steroidal antiinflammatory drug naproxen (NPX) as axial ligand(s) to inhibit the BC cells. DNP exhibited high cytotoxicity and antiinflammatory properties superior over NP, cisplatin and NPX; moreover, it displayed potent antitumor activity and almost no general toxicity in mice bearing triple‐negative breast cancer (TNBC). Mechanistic studies revealed that DNP could downregulate the expression of COX‐2 and PD‐L1 in vitro and vivo, inhibit the secretion of prostaglandin, reduce the expression of BC‐associated protein BRD4 and phosphorylation of extracellular signal‐regulated kinases 1/2 (Erk1/2), and block the oncogene c‐Myc in BC cells. These findings demonstrate that DNP is capable of intervening in inflammatory, immune, and metastatic processes of BC, thus presenting a new mechanism of action for anticancer platinum(IV) complexes. The multispecificity offers a special superiority for DNP to treat TNBC by combining chemotherapy and immunotherapy in one molecule.
Guest‐Reaction Driven Cage to Conjoined Twin‐Cage Mitosis‐Like Host Transformation
Authors: Cheng Pei‐Ming , Cai Li‐Xuan , Li Shao‐Chuan , Hu Shao‐Jun , Yan Dan‐Ni , Zhou Li‐Peng , Sun Qing‐Fu
Published: September 2020

We report here a guest‐reaction‐induced mitosis‐like host transformation from a known Pd4L2 cage 1 to a conjoined Pd6L3 twin‐cage 2 featuring two separate cavities. The encapsulation of 1‐hydroxymethyl‐2‐naphthol (G1), a known ortho‐quinone methide (o‐QMs) precursor, within the hydrophobic cavity of cage 1 is found crucial to realize the cage to twin‐cage conversion. Confined G1 molecules within the nanocavity undergo self‐coupling dimerization reaction to form 2,2′‐dihydroxy‐1,1′‐dinaphthylmethane (G2) which then triggers the cage to twin‐cage mitosis. The same conversion also proceeds, in a much faster rate, via the direct templation of G2, confirming the induced‐fit transformation mechanism. The structure of the (G2)2⊂2 host–guest complex has been established by X‐ray crystallographic study, where cis‐ to trans‐ conformational switch on one bridging ligand is revealed.
Oligosilanes as Silyl Radical Precursors through Oxidative Si−Si Bond Cleavage Using Redox Catalysis
Authors: Yu Xiaoye , Lübbesmeyer Maximilian , Studer Armido
Published: September 2020

Oligosilanes are of great interest in the fields of organic photonics and electronics. In this communication, a highly efficient visible‐light‐mediated hydrosilylation of electron‐deficient alkenes through cleavage of a trimethylsilyl‐polysilanyl Si−Si bond is explored. These reactions smoothly occur on readily available organo(tristrimethylsilyl)silanes and other oligosilanes in the presence of an IrIII‐based photo‐redox catalyst under visible light irradiation. Silyl radicals are generated through single electron oxidation of the oligosilane assisted by the solvent. The introduced method exhibits broad substrate scope and high functional group tolerance with respect to the organo(tristrimethylsilyl)silane and alkene components, enabling the construction of functionalized trisilanes. In addition, this catalytic system can be also applied to highly strained bicyclo[1.1.0]butanes as silyl radical acceptors.
Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses
Authors: Tindall Daniel J. , Mader Steffen , Kindler Alois , Rominger Frank , Hashmi A. Stephen K. , Schaub Thomas
Published: September 2020

Sugar alcohols are of great importance for the food industry and are promising building blocks for bio‐based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on commercially available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi‐gram scale allowing sugar alcohols to be isolated in large quantities at high atom economy.
Comparison of label‐free and label‐based approaches for surface‐enhanced Raman microscopic imaging of bacteria cells
Authors: Hickey Michael E. , Gao Siyue , He Lili
Published: September 2020

Surface‐enhanced Raman spectroscopic (SERS) approaches are emerging for bacteria analysis whereby bacteria cells can be measured based on their biochemical composition (label‐free) or with the aid of a chemical label to enhance the SERS signal. Combining a microscope, SERS microscopy is capable of imaging bacteria populations en masse based on specific spectrophotometric peaks. Here, we compared the label‐free and label‐based approaches to study Escherichia coli O157:H7 that was utilized as a model bacterium for SERS imaging analyses. Gold (Au) nanoparticles were utilized to enhance Raman scattering during this study and 3‐mercaptophenylboronic acid was utilized as a model chemical label for comparison against label‐free conditions. The result shows that SERS images of bacteria cells yielded measurable differences in precision, depending on the application of chemical labels. Chemical labels enabled SERS imaging of whole bacteria populations with single‐cell precision. Bacteria coated with labels were also easier to bring into focus using high‐magnification optical microscopy, without the need for immersion oil. Label‐free analyses of single‐cells were lower in geographic precision but provided opportunities to study the natural biochemistry of bacteria cells with strong accuracy. SERS analyses of label‐free bacteria cell components were conclusively improved in vitro on a time‐dependent basis. This concept can serve as an important benchmark when biochemically profiling or characterizing bacteria cells based on SERS. Electron micrographs proved that chemical labels can be utilized to increase nanoparticle contact with bacteria cells and reduce free nanoparticles that contribute to background noise in SERS spectra. We also demonstrate the use of both 3‐mercaptophenylboronic acid and propidium iodide to discriminate live and dead bacteria through the simultaneous collection of data from these two chemical labels. Label‐free approaches to SERS bacteria analyses are better suited for biochemical characterization and label‐based approaches are better suited when accounting for individual cells among a population.
Examining the Incidence and Clients’ Experiences of Single Session Therapy in Italy: A Feasibility Study
Authors: Cannistrà Flavio , Piccirilli Federico , Paolo D’Alia Pier , Giannetti Angelica , Piva Lorenza , Gobbato Ferruccio , Guzzardi Roberta , Ghisoni Alice , Pietrabissa Giada
Published: September 2020

Single session therapy (SST) postulates that one session can be sufficient for a client to take charge of the process and work toward their own solutions. Research has been conducted worldwide corroborating SST assumptions with several mental health conditions, but not in Italy. For the first time in Italy, this paper aims to explore: (1) if the most frequent number of sessions in traditional psychotherapy (not SST) is one (Study 1); and (2) the satisfaction of clients who attend SST services and the number who consider one session sufficient to address their presenting problem (Study 2). In Study 1, the records of 476 voluntary clients referred to three different traditional (not SST) psychological services in the west‐central region of Latium, Italy, were retrospectively screened, and the number of sessions attended by each client recorded. In Study 2, 85 consecutive clients who voluntarily asked for SST with seven mental health professionals across Italy received a link to an online ad hoc survey, 1–3 weeks after the consultation, evaluating their experience. Study 1 found that the most frequent number of traditional psychotherapeutic (not intentionally SST) sessions was one (124 out of 476 clients (26%). Study 2 found that 44 out of 85 clients (52%) considered one session to be enough, as they felt better or much better and chose not to attend further sessions. Of those who asked for a second session (41 clients), 33 clients (80.5%) indicated that the first session was not enough and 8 clients (19.5%) wanted to address a new problem. These results converge with previous international studies and provide encouragement for the use of SST in both private and public psychological services to address the demand for timely mental health services in Italy. Further research is needed to support the efficacy of SST and to evaluate its cost‐effectiveness.
Biomimetic phospholipid polymers for suppressing adsorption of saliva proteins on dental hydroxyapatite substrate
Authors: Ishihara Kazuhiko , Kozaki Yoichiro , Inoue Yuuki , Fukazawa Kyoko
Published: September 2020

To prevent infectious diseases induced by the adhesion of microorganisms and their metabolic products to dental implants, saliva protein adsorption, which induces the plaque deposition to the intraoral substrates should be inhibited. We used a water‐soluble 2‐methacryloyloxyethyl phosphorylcholine (MPC) polymer to modify the surface of hydroxyapatite (HAp) substrate, the main component of dental implant surface. The MPC polymer containing a catechol group at the terminal of polymer chain and amino groups in the side chain was synthesized by mimicking the mussel adhesive protein. The MPC polymer containing 2% of the primary amino groups showed effective adhesion to the HAp substrate. Mucin, the dental plaque protein, adsorbs on the HAp surface; however, the MPC polymer modification could reduce this adsorption amount by more than 98% compared to the original HAp substrate surface. Thus, the treatment of the MPC polymer has potential to reduce oral infection due to plaque deposition.
Unsupported electrospun membrane for water desalination using direct contact membrane distillation
Authors: Jalloul Ghadeer , Hashem M. Hadi , Tehrani‐Bagha Ali Reza , Ahmad Mohammad N. , Abu Tarboush Belal J.
Published: September 2020

In this project, an unsupported electrospun poly(vinylidene fluoride)‐co‐hexafluoropropylene (PVDF‐HFP) membrane was used for water desalination using direct contact membrane distillation (DCMD). The membrane was electrospun using a laboratory‐scale machine with multiple nozzles that was developed in‐house. Critical process parameters, including the applied voltage and polymer concentration, were optimized to obtain bead‐free electrospun membranes with fiber diameters less than 300 nm. To improve the membrane thermal stability and performance, the selected electrospun membrane was heat‐pressed at 160°C. The untreated and heat‐pressed membranes were tested in a DCMD setup at different feed temperatures (60, 70, and 80°C) and feed flow rates (0.4, 0.6, and 0.8 L/min), while maintaining the permeate temperature and flow rate at 20°C and 0.2 L/min, respectively. The modified electrospun membrane exhibited a very high permeate flux (>37.5 kg/m2/h) and a salt rejection rate of 99.99% at a feed temperature of 70°C. The performance of the heat‐pressed unsupported PVDF‐HFP electrospun membrane was nearly identical to a commercially available polytetrafluoroethylene (PTFE) supported membrane. These promising results demonstrate that relatively low‐cost electrospun membranes can be easily produced and successfully used in DCMD to minimize the capital cost and increase the energy efficiency of the process.
Surface modification of TiO2 particles with 12‐hydroxy stearic acid and the effect of particle size on the mechanical and thermal properties of thermoplastic polyurethane urea elastomers
Authors: Wang Shuxiao , Wang Xiaoyan , Huang He
Published: September 2020

The efficient surface modification of titanium dioxide (TiO2) particles with different sizes was first carried out with “water only method” (Appl. Surf. Sci. 2018, 447, 664–672) developed in our group using 12‐hydroxy stearic acid (12‐HSA) as the modifier. The 12‐HSA‐modified TiO2 particles with different sizes were then used to explore their effect on the mechanical and thermal properties of a thermoplastic polyurethane urea (TPUU) elastomer with superior mechanical and thermal properties produced newly in our lab using nonsymmetric alicyclic diisocyanate and diamine. Orthogonal experimental results showed that the order of impact of each factor on the modification efficiency of TiO2 particles was: Temperature > time > modifier content. It was found that, in the nanometer (≤100 nm) range, smaller particles were more helpful to enhance the tensile strength of the TPUU elastomer, while larger ones to increase more significantly the elongation at break. Besides, the TiO2/polyurethane urea nanocomposites exhibited much better thermomechanical performance than the pristine TPUU elastomer, and the thermomechanical performance of the nanocomposites increased with decreasing particle size.
Thermal decomposition behavior of 3D printing filaments made of wood‐filled polylactic acid/starch blend
Authors: Sun Yufeng , Lee Danbee , Wang Yapeng , Li Suiliang , Ying Jilai , Liu Xinping , Xu Guangyin , Gwon Jaegyoung , Wu Qinglin
Published: September 2020

Dynamic thermogravimetric analysis under nitrogen environment was used to understand the thermal decomposition process of 3D printing filaments made of wood‐filled polylactic acid (PLA)/starch blend. The characteristic temperatures and apparent activation energy (AAE) of the filaments with various starch contents were calculated with well‐known kinetic models by Friedman, Flynn–Wall–Ozawa, Coats–Redfern, and Kissinger. With the increased starch content in the filament, the onset thermal decomposition temperatures of the filaments decreased gradually from 272.4 to 155.1°C. The thermal degradation degree became smaller, and the transitional temperature interval became larger with increased starch proportion. The AAE values of the three types of filaments with different starch ratios varied between 97 and 114 kJ/mol, depending on material composition and method of calculation. The four kinetics methods provide complementary techniques for analyzing thermal stability behavior of composite materials. The improved understanding of thermal decomposition behavior of PLA‐starch‐wood composites can help develop PLA/starch‐based filaments for 3D printing.
Benzoxazine monomers based on aromatic diamines and investigation of their polymerization by rheological and thermal methods
Authors: Sarychev Igor A. , Kireev Vyacheslav V. , Khmelnitskiy Vladimir V. , Vorobyeva Viktoria V. , Tupikov Anton S. , Haskov Maksim A. , Sirotin Igor S.
Published: September 2020

In the present article with the aim to find new polybenzoxazines with improved thermal properties, new benzoxazine monomers based on phenol and the following aromatic diamines were synthesized: 3,4′‐oxydianiline (P‐3,4′oda); o‐tolidine (P‐ot); m‐tolidine (P‐mt) and 4,4′‐(1,3‐phenylenedioxy)dianiline (P‐tper) and their comparison with the previously known benzoxazines based on 4,4′‐diaminodiphenylmethane (P‐ddm); 4,4′‐oxydianiline (P‐4,4′‐oda) and 2,2‐Bis[4‐(4‐aminophenoxy)phenyl]propane (P‐bapp). The dependence of the thermal and rheological characteristics on the structure of benzoxazine monomers based on various diamines was estimated and possible methods for their processing were identified. All the polybenzoxazines obtained in this work have high char yield and reduced flammability. It was found that the structure of the diamine can have a fundamental effect on both the rheological properties and heat resistance of polybenzoxazines. The benzoxazine monomers P‐ddm, P‐tper and P‐4,4′oda retain viscosity up to 1 Pa s. at 110°C for 2 h, the P‐tper monomer with a resorcinol bridge has about five times lower viscosity compared to the P‐bapp monomer with a bisphenol A bridge. Polybenzoxazines based on the monomers P‐ddm, P‐mt, P‐bapp and P‐tper show excellent thermal stability with a temperature of 10% weight loss above 400°C. In particular,Tgof P‐3,4′oda and P‐mt monomers is relatively high (202 and 239°C, respectively), while P‐ot's is unusually low (115°C), which may be caused by the specific effect of the substituents in the aromatic ring of the amine and their position.
Existing protected areas provide a poor safety‐net for threatened Amazonian fish species
Authors: Dagosta Fernando C. P. , de Pinna Mário , Peres Carlos A. , Tagliacollo Victor A.
Published: September 2020

Freshwater ecosystems represent less than 0.01% of Earth's surface water but proportionately encompass the most species‐rich environment on the planet, including nearly one‐third of all vertebrate species. Even though inland continental waters are widely regarded as highly endangered ecosystems, their species assemblages are mostly ignored in conservation plans, largely because spatial patterns of freshwater species remain poorly understood. This is particularly severe throughout the Neotropics, most notably in the Amazon superbasin, where the sheer biotic diversity is coupled with a severe lack of biodiversity knowledge at several levels.

Spatial patterns of Neotropical freshwater fishes focusing mainly on the Amazon superbasin were investigated. First, Endemic Amazonian Fish Areas (EAFAs) representing central units for the conservation of continental fishes were delimited. Interpolated maps were then analysed using alternative methodologies to delimit spatial patterns of diversity and endemicity across the Amazon superbasin. Several biogeographical analyses used a comprehensive dataset of species and geographical coordinates of Amazonian fishes.

The results reveal well‐defined spatial patterns of species richness and endemicity in the Amazonian fish fauna, showing that most protected areas are concentrated in a single bioregion (Amazon lowlands). Those areas are incongruent and insufficient to protect endemic and threatened species, which are mostly distributed in upland regions.

Effective conservation of the Amazonian fish fauna should include EAFAs within protected areas, especially those undergoing deforestation and hydropower development pressure and containing a high concentration of threatened species.

The following EAFAs should be considered as conservation priorities: Upper Araguaia, Upper Tocantins, Lower Teles Pires/Serra do Cachimbo, Chapada dos Parecis and Upper Marañon. These regions should be urgently protected to avert the loss of important trophic relationships and unique elements of the Amazonian fish fauna.
Construction and analysis of the protein–protein interaction network for the olfactory system of the silkworm Bombyx mori
Authors: Xin Shanghong , Zhang Wenjun
Published: September 2020

Olfaction plays an essential role in feeding and information exchange in insects. Previous studies on the olfaction of silkworms have provided a wealth of information about genes and proteins, yet, most studies have only focused on a single gene or protein related to the insect's olfaction. The aim of the current study is to determine key proteins in the olfactory system of the silkworm, and further understand protein–protein interactions (PPIs) in the olfactory system of Lepidoptera. To achieve this goal, we integrated Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and network analyses. Furthermore, we selected 585 olfactory‐related proteins and constructed a (PPI) network for the olfactory system of the silkworm. Network analysis led to the identification of several key proteins, including GSTz1, LOC733095, BGIBMGA002169‐TA, BGIBMGA010939‐TA, GSTs2, GSTd2, Or‐2, and BGIBMGA013255‐TA. A comprehensive evaluation of the proteins showed that glutathione S‐transferases (GSTs) had the highest ranking. GSTs also had the highest enrichment levels in GO and KEGG. In conclusion, our analysis showed that key nodes in the biological network had a significant impact on the network, and the key proteins identified via network analysis could serve as new research targets to determine their functions in olfaction.
Explicit diversification of search results across multiple dimensions for educational search
Authors: Yigit‐Sert Sevgi , Altingovde Ismail Sengor , Macdonald Craig , Ounis Iadh , Ulusoy Özgür
Published: September 2020

Making use of search systems to foster learning is an emerging research trend known as search as learning. Earlier works identified result diversification as a useful technique to support learning‐oriented search, since diversification ensures a comprehensive coverage of various aspects of the queried topic in the result list. Inspired by this finding, first we define a new research problem, multidimensional result diversification, in the context of educational search. We argue that in a search engine for the education domain, it is necessary to diversify results across multiple dimensions, that is, not only for the topical aspects covered by the retrieved documents, but also for other dimensions, such as the type of the document (e.g., text, video, etc.) or its intellectual level (say, for beginners/experts). Second, we propose a framework that extends the probabilistic and supervised diversification methods to take into account the coverage of such multiple dimensions. We demonstrate its effectiveness upon a newly developed test collection based on a real‐life educational search engine. Thorough experiments based on gathered relevance annotations reveal that the proposed framework outperforms the baseline by up to 2.4%. An alternative evaluation utilizing user clicks also yields improvements of up to 2% w.r.t. various metrics.
Recent Progress on Defect‐rich Transition Metal Oxides and Their Energy‐Related Applications
Authors: Wang Yanzhi , Liang Zuozhong , Zheng Haoquan , Cao Rui
Published: September 2020

The applications of many energy‐related electrochemical energy conversion and storage devices are changing with each passing day. Oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) are the key steps in the commercial application of these energy conversion/storage equipment. Defect‐rich transition metal oxides (TMOs), such as Co, Mn, Fe, Ni, etc., have always been one of the most promising electrocatalysts, which are cheap, easy to obtain, high in catalytic activity and stable during electrocatalysis. In this review, we first introduce the definition, classification, characteristics, and construction of defects. Then, the latest developments of defect‐rich TMO electrocatalysts in electrocatalysis and energy conversion storage device is summarized. Furthermore, the relationship between defects and activity and the potential mechanism are also discussed. The defects in defect‐rich TMOs can adjust the surface/interface electronic structure of the electrocatalyst, change the adsorption energy of the intermediate product, or increase the intrinsic catalytic activity of active sites, which are beneficial for enhanced catalytic performance. Finally, the current challenges and prospects of defect‐rich TMO electrocatalysts are proposed. Therefore, the introduction of defects in TMO will be a potential strategy for the rational design of high‐performance electrocatalysts in the future.
Recent Progress on Nanostructured Layered Double Hydroxides for Visible‐Light‐Induced Photoreduction of CO2
Authors: Tan Ling , Wang Zelin , Zhao Yufei , Song Yu‐Fei
Published: September 2020

Photoreduction of CO2 into solar fuels is usually regarded as one of the promising solutions to overcome environmental pollution and the energy crisis. The main challenge in CO2 photoreduction (CO2PR) is the low efficiency and poor selectivity. Layered double hydroxides (LDHs) are a class of 2D materials, consisting with M(OH)6 octahedra in the host layers and intercalated anions. Owing to the tuneable composition, particle size, morphology, and virtue coordinatively unsaturated active sites, a series of efficient strategies (morphology control, heterostructure, defect control, etc.) in LDH‐based photocatalysts have been efficiently developed to enhance the photocatalytic selectivity and activity for CO2PR. This review summarizes recent progress on the LDH‐based photocatalysts for CO2PR.
Prespecified‐time distributed synchronization of Lur'e networks with smooth controllers
Authors: Shao Shao , Cao Jinde , Hu Yuanfa , Liu Xiaoyang
Published: September 2020

Instead of estimating the upper bound of the settling time in traditional finite‐time control methods, this paper considers the prespecified‐time synchronization of Lur'e networks, in which the settling time can be preset according to the requirement of tasks. Some smooth controllers are designed to achieve the goal of synchronization in a prespecified time and to maintain the synchronization after that. In addition, without the help of signum function or fractional power state feedback, the proposed control protocols are based on regular feedback and are smooth everywhere. Finally, two numerical examples with Chua's circuits are carried out to substantiate the effectiveness of the proposed designs.