bluuebunny/crossref_metadata_2025 huggingface dataset:
Estrés oxidativo en células endoteliales inducido por el suero de mujeres con diferentes manifestaciones clínicas del síndrome antifosfolípido
Authors: Velásquez Manuela , Granada Manuel Alejandro , Galvis Juan Camilo , Álvarez Ángela María , Cadavid Ángela
Published: December 2019

Introducción. El síndrome antifosfolípido se caracteriza por la presencia persistente de anticuerpos antifosfolípidos y manifestaciones clínicas de trombosis o morbilidad gestacional, las cuales se asocian con estrés oxidativo y disfunción endotelial.Objetivo. Evaluar los marcadores de estrés oxidativo en células endoteliales, inducidos por el suero de mujeres con diferentes manifestaciones clínicas del síndrome antifosfolípido y analizar la capacidad antioxidante de los sueros.Materiales y métodos. Se incluyeron 48 mujeres que fueron clasificadas así: presencia de anticuerpos antifosfolípidos y criterios clínicos de morbilidad gestacional, trombosis vascular o ambas. Como grupos control se incluyeron mujeres negativas para anticuerpos antifosfolípidos. En un modelo in vitro de células endoteliales estimuladas con los sueros de las mujeres del estudio, se determinaron algunos marcadores de estrés oxidativo por citometría de flujo. También, se analizó la capacidad antioxidante de los sueros incluidos.Resultados. Los sueros de los grupos de mujeres con síndrome antifosfolípido que presentaban trombosis, con morbilidad gestacional o sin ella, generaron un incremento significativo (p<0,05 y p<0,001) en los marcadores de estrés oxidativo endotelial, en contraste con el control de suero humano normal. No se observaron diferencias en el efecto de los sueros de los diferentes grupos de estudio sobre la lipoperoxidación endotelial. Tampoco se encontró diferencia en la actividad antioxidante de los sueros.Conclusión. El estrés oxidativo mitocondrial en el endotelio se asocia con la presencia de trombosis. Sin embargo, cuando esta se asocia con morbilidad gestacional, también se genera estrés oxidativo intracelular
PgTI, the First Bioactive Protein Isolated from the Cactus Pilosocereus gounellei, is a Trypsin Inhibitor with Antimicrobial Activity
Authors: Da Rocha Filho Cláudio Alberto Alves , Karla Amorim Poliana , Albuquerque Lima Thâmarah de , Michelle da Silva Pollyanna , Celine de Moura Maiara , Barroso Coelho Luana Cassandra Breitenbach , Benedeta Zingali Russolina , Viana Pontual Emmanuel , Henrique Napoleão Thiago , Guedes Paiva Patrícia Maria
Published: December 2019

Aims: This work aimed to isolate, characterize and evaluate the antimicrobial activity of a trypsin inhibitor (PgTI) from the stem of Pilosocereus gounellei.

Place and Duration of Study: Departamento de Bioquímica, Universidade Federal de Pernambuco between March 2013 and October 2018. Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro between June and July 2018.

Methodology: PgTI was isolated from P. gounellei stem extract by gel filtration and ion exchange chromatographies. The inhibitor was characterized by isoelectric focusing, polyacrylamide gel electrophoresis, tryptic digestion followed by mass spectrometry analysis and for stability towards heating. Antibacterial and antifungal activities were investigated through broth microdilution assays. Viability of the microbial cells was also evaluated by flow cytometry analysis using thiazol orange and propidium iodide.

Results: PgTI appeared as a single polypeptide band of 37.1 kDa and isoelectric point (pI) 5.88. The inhibition constant (Ki) for bovine trypsin was 14 nM and mass spectrometry analysis of PgTI did not reveal similarities with other plant proteins. Trypsin inhibitor activity was stable at temperatures up to 50ºC. PgTI inhibited growth of Gram-positive and Gram-negative bacteria (minimal inhibitory concentrations (MIC) from 7.5 to150 µg/mL) with bactericidal activity only against Escherichia coli (minimal bactericidal concentration: 75.0 µg/mL). PgTI also inhibited the growth of Candida krusei (MIC of 60 µg/mL). Flow cytometry confirmed that PgTI did not affect the viability of E. coli and C. krusei cells at the MIC.

Conclusion: This is the first report on a bioactive protein purified from P. gounellei, which provides biotechnological value to this cactus.
Rilton Ferreira Borges, Zola e as percepções do tempo: Naturalismo e História em Germinal, Alameda, 2018
Authors: Souza Raick De Jesus
Published: December 2019

O objetivo central do presente trabalho é analisar a obra Zola e as percepções do tempo em Germinal de autoria de Rilton Borges (2018). Para tal empreendido, destacaremos as teses centrais apontadas em cada capítulo, além de evidenciar o rico debate historiográfico no qual o autor se insere. Espera-se contribuir dessa forma com o campo da História, especialmente, no que se refere aos estudos acerca das temporalidades. O presente estudo também busca reconhecer o valor do presente trabalho, diga-se de passagem, o primeiro entre nós em propor uma discussão acerca das diversas concepções de "tempo" presentes no movimento Naturalista.
Reflexões sobre o fascismo e a violência no Brasil: a situação das classes trabalhadoras no momento de crise orgânica do capital.
Authors: Schlesener Anita Helena , Mezzaroba Gilson , Garcia de Almeida Tariani Maria
Published: December 2019

Este artigo tem o objetivo de fazer algumas observações sobre o fenômeno mundial de ascensão de movimentos reacionários que retomam símbolos fascistas e nazistas e como estas ideologias se apresentam no Brasil, nas várias formas que assume a violência urbana e rural. Retomamos alguns aspectos da atual fase da luta de classes, que entendemos como uma ostentação de um comportamento violento e preconceituoso, enquanto parte de uma política conservadora e repressiva num momento de grave crise financeira, que se estendeu dos centros capitalistas para a periferia, acompanhando as vias de internacionalização do capitalismo. Fazemos um esboço das raízes clássicas do fascismo para explicitar suas formas no atual momento histórico.
O fascismo e a sua política (Escritos Políticos)
Authors: Gramsci Antonio
Published: December 2019

Texto que aborda o fascismo, como movimento de reacção armada que se propõe o objetivo de desagregar e de desorganizar a classe trabalhadora para a imobilizar, enquadra-se no plano da política tradicional das classes dirigentes italianas e na luta do capitalismo contra a classe operária. E por isso favorecido, na sua origem, na sua organização e no seu caminho por todas os velhos grupos dirigentes, indistintamente, com preferência, porém, pelos agrários que sentem mais ameaçadora a pressão das plebes rurais. Socialmente, porém, o fascismo encontra a sua base na pequena burguesia urbana e numa nova burguesia agraria saída de uma transformação da propriedade rural em algumas regiões (fenómenos do capitalismo agrário na Emilia, origem de uma categoria de intermediários rurais.
"Ela só quer jogar o futebol dela": quando meninas brincam e tensionam a supremacia masculina e as expectativas de gênero juntos aos meninos no espaço da escola
Authors: Pereira Artur Oriel
Published: December 2019

Este artigo procura realizar algumas reflexões sobre os gestos de resistência e transgressões de meninas de 7 anos de idade contra as normatizações machistas hetero-patriarcais que impõem determinadas posturas, execução de brincadeiras e restringe o uso de espaços sociais para os diferentes sujeitos. Trata-se de uma pesquisa realizada na escola, nos anos iniciais do ensino fundamental, construída com base no pensamento feminista e os estudos da criança e da infância, buscando a ampliação de nossas percepções a respeito das culturas infantis produzidas pelas crianças que com suas práticas, experiências, criações, invenções e movimentos tensionam as tramas do sexismo e machismo presentes na sociedade.
Vertebrate Embryo: Patterning the Neural Crest Lineage
Authors: Kalcheim Chaya
Published: December 2019

Neural crest (NC) cells form as epithelial progenitors during the process of neurulation, then undergo an epithelial‐to‐mesenchymal transition and become motile. As mesenchymal cells, they migrate through stereotypical pathways, reach their homing sites and differentiate into a large variety of derivatives that are specific and variable along the embryonic axis. These include neurons and glia of the sensory and autonomic nervous system, pigment cells, chromaffin cells of the adrenal gland and mesectoderm in the head region. Given that a few initial progenitors expand and diversify so substantially, the NC provides an excellent model to investigate fundamental questions in Developmental Biology, that is, defining the state of commitment of the different precursors throughout ontogeny, unravelling the nature of cellular interactions among adjacent crest cells and between crest progenitors and their environment, and elucidating the molecular basis of lineage segregation, cell migration and terminal differentiation.

Key Concepts

NC progenitors are multipotent at the population level and become differentially restricted during ontogeny.

Lineage segregation in the trunk is likely to begin before NC emigration from the neural tube.

Epithelial‐to‐mesenchymal transition of NC progenitors is orchestrated by a network of factors (BMP/noggin, Wnt1 and Yap) acting in concert with adhesion molecules, RhoGTPases, extracellular matrix components and cell‐intrinsic determinants.

NC cells migrate stereotypically to their homing sites and migration seems to be largely channelled by interactions between inhibitory environmental signals and NC cells expressing their cognate receptors.

Specification and subsequent differentiation of NC progenitors into the various phenotypes are regulated by reiterative signals (i.e. BMPs, Wnts) that induce lineage‐specific codes of transcription factors.

Schwann cell progenitors residing along peripheral nerves represent a multipotent source for various neuronal and nonneural derivatives

In spite of undergoing early fate restrictionsin vivo, some NC cells, even following differentiation, retain significant plasticity as evidenced byin vitroanalysis.
Transdifferentiation
Authors: Burke Zoë , Tosh David
Published: December 2019

The irreversible switch of one differentiated cell type to another is known as transdifferentiation. To consider that such cell‐type switching events arise through mistakes in normal development and tissue repair is a misnomer. It has long been accepted that many invertebrate organisms have the potential for transdifferentiation as part of their normal development or as a mechanism for replacing and regenerating lost or damaged tissue. Although their capacity for transdifferentiation is limited, this is also true for vertebrates and as such, several examples of naturally occurring, experimentally induced and disease‐related cell‐type interconversions have been described for higher organisms. These cell‐type conversions have important implications for understanding normal cell and tissue differentiation, the molecular and cellular basis of disease and may even facilitate the development of novel strategies for cell replacement and gene therapy in regenerative medicine.

Key Concepts

For a cell‐type conversion to be classified as transdifferentiation, two criteria have to be fulfilled (1) describe the loss of one cell phenotype and the gain of another and (2) demonstrate a direct ancestor–descendant relationship between the two cell types.

Transdifferentiation is associated with a discrete change in the programme of gene expression.

Transdifferentiation belongs to a broader group of cell type conversions called metaplasias.

Metaplasia is derived from the Greek word ‘metaplassein’ meaning ‘to mould into a new form’ and was first used to define the unexpected appearance of foreign tissues in ectopic sites.

Metaplasias also includes the conversion of one tissue‐specific stem cell to another tissue stem cell.

Some invertebrates demonstrate a remarkable capacity for transdifferentiation as part of their regenerative response to cell or tissue damage.

The potential for transdifferentiation in vertebrates is relatively limited compared to invertebrate organisms.

During transdifferentiation, cells pass through an intermediate state that may be progenitor‐like or unspecific, the nature of these intermediates is poorly understood.
Tough, Additively Manufactured Structures Fabricated with Dual‐Thermoplastic Filaments
Authors: Hart Kevin R. , Dunn Ryan M. , Wetzel Eric D.
Published: December 2019

Fused filament fabrication (FFF) is the most common additive manufacturing technology, but parts fabricated using FFF lack sufficient mechanical integrity for most engineering applications. Herein, a dual material (DM) filament comprising acrylonitrile butadiene styrene (ABS) with a star‐shaped polycarbonate (PC) core is fabricated using a novel thermal draw process. This DM filament is then used as feedstock in a conventional FFF printer to create 3D solid bodies with a composite ABS/PC meso‐structure. Subjecting these parts to annealing temperatures intermediate between the glass‐transition temperatures of ABS and PC produces a solid body with ductility comparable to injection‐molded ABS and fracture toughness values 15 × higher than comparable as‐printed ABS structures. The PC skeleton of specimens fabricated using the DM filament resists creep and polymer relaxation to maintain accurate part geometry during annealing. This novel DM filament can revolutionize additive manufacturing allowing low‐cost printers to produce parts with mechanical properties competitive with injection‐molded plastics.
Reactive Oxygen Species‐Scavenging Scaffold with Rapamycin for Treatment of Intervertebral Disk Degeneration
Authors: Bai Jinyu , Zhang Yingzi , Fan Qin , Xu Jialu , Shan Huajian , Gao Xiang , Ma Qingle , Sheng Lei , Zheng Xin , Cheng Weinan , Li Dazhuang , Zhang Mingchao , Hao Yu , Feng Liangzhu , Chen Qian , Zhou Xiaozhong , Wang Chao
Published: December 2019

The chronic inflammatory microenvironment is characterized by the elevated level of reactive oxygen species (ROS). Here, it is hypothesized that developing an ROS‐scavenging scaffold loaded with rapamycin (Rapa@Gel) may offer a new strategy for modulating the local inflammatory microenvironment to improve intervertebral disk tissue regeneration. The therapeutic scaffold consisting of ROS‐degradable hydrogel can be injected into the injured degeneration site of intervertebral disk (IVD) and can release therapeutics in a programmed manner. The ROS scavenged by scaffold reduces the inflammatory responses. It is found that when rats are treated with Rapa@Gel, this results in an increase in the percentage of M2‐like macrophages and a decrease in M1‐like macrophages in the inflammatory environment, respectively. Regeneration of IVD is achieved by Rapa@Gel local treatment, due to the increased M2 macrophages and reduced inflammation. This strategy may be extended to the treatment of many other inflammatory diseases.
Pd@Au Bimetallic Nanoplates Decorated Mesoporous MnO2 for Synergistic Nucleus‐Targeted NIR‐II Photothermal and Hypoxia‐Relieved Photodynamic Therapy
Authors: Zhang Yiyi , Lv Fan , Cheng Yaru , Yuan Zhipeng , Yang Fan , Liu Conghui , Cao Yu , Zhang Kai , Lu Huiting , Zada Shah , Guo Shaojun , Dong Haifeng , Zhang Xueji
Published: December 2019

Bimetallic nanoparticles have received considerable attention owing to synergistic effect and their multifunctionality. Herein, new multifunctional Pd@Au bimetallic nanoplates decorated hollow mesoporous MnO2 nanoplates (H‐MnO2) are demonstrated for achieving not only nucleus‐targeted NIR‐II photothermal therapy (PTT), but also tumor microenvironment (TME) hypoxia relief enhanced photodynamic therapy (PDT). The Pd@Au nanoplates present a photothermal conversion efficiency (PTCE) as high as 56.9%, superior to those PTAs activated in the NIR‐II region such as Cu9S5 nanoparticles (37%), Cu3BiS3 nanorods (40.7%), and Au/Cu2−xS nanocrystals (43.2%). They further functionalize with transactivator of transcription (TAT) moiety for cell nuclear‐targeting and biodegradable hollow mesoporous MnO2 (≈100 nm) loaded with photosensitizer Ce6 (TAT‐Pd@Au/Ce6/PAH/H‐MnO2) to construct a hierarchical targeting nanoplatform. The as‐made TAT‐Pd@Au/Ce6/PAH/H‐MnO2 demonstrates good premature renal clearance escape ability and increased tumor tissue accumulation. It can be degraded in acidic TME and generate O2 by reacting to endogenous H2O2 to relieve the hypoxia for enhanced PDT, while the released small TAT‐Pd@Au nanoplates can effectively enter into the nucleus to mediate PTT. As a result, a remarkable therapeutic effect is achieved owing to the synergistic PTT/PDT therapy. This hierarchical targeting, TME‐responsive, cytoplasm hypoxia relief PDT, and nuclear NIR‐II PTT synergistic therapy can pave a new avenue for nanomaterials‐based cancer therapy.
A 3D Hemispheric Steam Generator Based on An Organic–Inorganic Composite Light Absorber for Efficient Solar Evaporation and Desalination
Authors: Chen Guoliang , Zhang Nan , Li Na , Yu Liangmin , Xu Xiaofeng
Published: December 2019

Solar‐driven interfacial steam generation is emerging as a sustainable and environmental‐friendly technology for potential applications in sterilization, desalination, and wastewater treatment. Despite the impressive progress achieved at labs, only few designs specialize in ambient and outdoor applications. Herein, a 3D hemispheric steam generator composed of nanocarbon (CB):poly(methyl methacrylate) (PMMA) composite materials as a light‐absorber, which boosts the light absorption in a wide range of incident angles, is reported. Gratifyingly, the 3D hemispheric steam generator afford efficient water evaporation and high photothermal conversion efficiencies of ≈87% when employing moderate sunlight (0.75 sun) with varied incident angles (90°, 80°, and 65°) in a set of indoor measurements. The more hydrophobic surface of the light‐absorber enabled by PMMA leads to better durability and avoids significant salt accumulation for solar desalination. This work highlights the intriguing prospect of this novel 3D hemispheric design and elegant organic–inorganic composite concept to realize efficient clean water production for potential real‐world applications.
Whispering Gallery Modes at THz
Authors: Prabhu Shriganesh S. , Achanta Venu Gopal
Published: December 2019

Whispering gallery modes (WGM) offer strong confinement of electromagnetic radiation to specific resonances supported by the geometry of the resonator. In fact, highest ever quality factors are reported in optical and near‐infrared WGMs along with their applications. Terahertz (THz) radiation offers a unique spectroscopic window to probe materials and has applications in security, sensing, and telecommunication. WGMs at THz have untapped potential for light–matter interaction studies and wide‐ranging applications. In this review, an educational overview of WGMs is given, followed by a review of the THz WGMs and their applications.
Lithography‐Free Random Bismuth Nanostructures for Full Solar Spectrum Harvesting and Mid‐Infrared Sensing
Authors: Soydan Mahmut Can , Ghobadi Amir , Yildirim Deniz Umut , Duman ElifSarıgül , Bek Alpan , Erturk Vakur Behcet , Ozbay Ekmel
Published: December 2019

A lithography‐free, double‐functional single bismuth (Bi) metal nanostructure is designed, fabricated, and characterized for ultrabroadband absorption in the visible (vis) and near‐infrared (NIR) ranges, and for a narrowband response with ultrahigh refractive index sensitivity in the mid‐infrared (MIR) range. To achieve a large‐scale fabrication of the design in a lithography‐free route, the oblique‐angle deposition approach is used to obtain densely packed and randomly spaced/oriented Bi nanostructures. It is shown that this fabrication technique can provide a bottom‐up approach to controlling the length and spacing of the design. The characterization findings reveal a broadband absorbance above 0.8 in vis and NIR, and a narrowband absorbance centered around 6.54 µm. Dense architecture and extraordinary permittivity of Bi provide strong field confinement in ultrasmall gaps between nanostructures, and this can be utilized for a sensing application. An ultrahigh sensitivity of 2151 nm refractive‐index unit (RIU–1) is acquired, which is, as far as it is known, the experimentally highest sensitivity attained so far. The simple and large‐scale compatible fabrication route of the design together with the extraordinary optical response of Bi coating makes this design promising for many optoelectronic and sensing applications.
A Triphasic Bifunctional Oxygen Electrocatalyst with Tunable and Synergetic Interfacial Structure for Rechargeable Zn‐Air Batteries
Authors: Zhu Jianbing , Xiao Meiling , Li Gaoran , Li Shuang , Zhang Jing , Liu Guihua , Ma Lu , Wu Tianpin , Lu Jun , Yu Aiping , Su Dong , Jin Huile , Wang Shun , Chen Zhongwei
Published: December 2019

Atomic‐scale design of interfacial structure is an intriguing but challenging approach to developing efficient heterogenous catalysts for bifunctional oxygen electrocatalysis. Herein, an exquisite triphasic interfacial structure featuring the encapsulation of FexNi alloy in a graphitic shell with a partial exposure of the FeOy thin‐layered surface is manipulated via an electronic modulation strategy. The spontaneous integration of well‐crystallized metal alloy, carbon shell with a tunable active FeOy layer, not only guarantees smooth charge transfer across the thin oxide layer, but also generates the synergistic effect at the interface, thus dramatically boosting the intrinsic activity of oxygen catalysis. Benefiting from these attributes, the hybrid catalyst outperforms the commercial noble‐metal benchmarks with a higher half‐wave potential of 0.890 V for oxygen reduction reaction and lower overpotential of 308 mV at 10 mA cm−2 for the oxygen evolution reaction in alkaline media. Beyond that, a high‐performance rechargeable Zn‐air battery is realized with a narrow voltage gap of 0.742 V and excellent cyclability over 500 cycles at 10 mA cm−2, demonstrating the great potential of the as‐developed triphasic electrocatalyst for practical applications.
Relationship of sanitation, water boiling, and mosquito nets to health biomarkers in a rural subsistence population
Authors: Dinkel Katelyn A. , Costa Megan E. , Kraft Thomas S. , Stieglitz Jonathan , Cummings Daniel K. , Gurven Michael , Kaplan Hillard , Trumble Benjamin C.
Published: December 2019

Objectives

Throughout human evolutionary history, parasites and pathogens were a major cause of mortality‐modern urban life with public health infrastructure has changed disease exposure. We examine associations between boiling water, using latrines, mosquito net usage, and biomarkers among the Tsimane, a nonindustrial subsistence population with little public health infrastructure.

Methods

We conducted cross sectional surveys on water, latrines, and bed nets among 507 heads of households (aged 18‐92 years, median age 41 years). Regression models estimated associations between behaviors and health biomarkers (ie, white blood cell count [WBC], hemoglobin, eosinophil count, and erythrocyte sedimentation rate) adjusting for age, sex, body mass index, wealth, schooling, and distance to the nearby market town.

Results

Latrine use is associated with 6.5% lower WBC count (β = −679.6, P = .031, SE = 314.1), 17.4% lower eosinophil counts (β = −244.7, P = .023, SE = 107.2), and reduced odds of eosinophilia (adjusted OR = 0.40, P < .019, 95% CI = 0.18‐0.86). Boiling water and mosquito net use are not significantly associated with any biomarkers measured.

Conclusions

In a subsistence population currently undergoing epidemiological transition, we find that latrine use was associated with several objective measures of health. This suggests that relatively low cost and low maintenance public health interventions may wish to focus on latrine use, as there is unmet need and potential health benefits for those who use latrines. Additionally, while the cost is higher, public health organizations aimed at improving sanitation may be able to use minimally invasive field‐collected biomarkers as a diagnostic to objectively test the efficacy of interventions with greater specificity than anthropometric measurements.
Respirable coal mine dust at surface mines, United States, 1982–2017
Authors: Doney Brent C. , Blackley David , Hale Janet M. , Halldin Cara , Kurth Laura , Syamlal Girija , Laney A. Scott
Published: December 2019

Background

Exposure to respirable coal mine dust can cause pneumoconiosis, an irreversible lung disease that can be debilitating. The mass concentration and quartz mass percent of respirable coal mine dust samples (annually, by occupation, by geographic region) from surface coal mines and surface facilities at U.S. underground mines during 1982‐2017 were summarized.

Methods

Mine Safety and Health Administration (MSHA) collected and analyzed data for respirable dust and a subset of the samples were analyzed for quartz content. We calculated the respirable dust and quartz concentration geometric mean, arithmetic mean, and percent of samples exceeding the respirable dust permissible exposure limit (PEL) of 2.0 mg/m3, and the average percent of quartz content in samples.

Results

The geometric mean for 288 705 respirable dust samples was 0.17 mg/m3 with 1.6% of the samples exceeding the 2.0 mg/m3 PEL. Occupation‐specific geometric means for respirable dust in active mining areas were highest among drillers. The geometric mean for respirable dust was higher in central Appalachia compared to the rest of the U.S. The geometric mean for respirable quartz including 54 040 samples was 0.02 mg/m3 with 15.3% of these samples exceeding the applicable standard (PEL or reduced PEL). Occupation‐specific geometric means for respirable quartz were highest among drillers.

Conclusion

Higher concentrations of respirable dust or quartz in specific coal mining occupations, notably drilling occupations, and in certain U.S. regions, underscores the need for continued surveillance to identify workers at higher risk for pneumoconiosis.
Fetoplacental ratios in stillbirths and second trimester miscarriages
Authors: McPherson Elizabeth
Published: December 2019

An abnormal fetoplacental (F/P) ratio is a risk factor for poor pregnancy outcomes including fetal death, but studies of F/P ratio among stillbirths are limited. In the Wisconsin Stillbirth Service Program cohort of second and third trimester fetal deaths, 1,022 were at ≥24 weeks with data on fetal and placental weight. Comparison with data for viable infants of the same gestational ages (GAs) showed that the F/P ratio increases more rapidly with GA for stillbirths than for viable infants. While placentas of stillborn infants are small at all GA, weights of deceased fetuses are lowest early in the second trimester, becoming nearly normal by term. Excess high F/P ratios are noted at all GAs, increasing toward term, while low ratios are frequent at early gestation but rare near term. Analysis by cause of death shows that F/P ratios are markedly elevated for placental and maternal causes (about 50% above the 90th centile), somewhat elevated for cord accidents, non‐hydropic fetal, and unknown causes (about 1/3 above the 90th centile), and variable with 40% below the 10th centile for hydropic stillbirths. Across all causes and GAs, placental weights are more abnormal than fetal weights, suggesting that diminished placental function may contribute to fetal demise even when non‐placental causes (e.g., premature membrane rupture, cord accidents, and chromosomal disorders) are identified. About half of all stillbirths have abnormal F/P ratios, suggesting that improvements in prenatal assessment of placental size and function might aid in identifying pregnancies at risk for demise; unfortunately, therapeutic options for ongoing pregnancies with diminished placental function remain limited.
Current state of research on non‐human primate models of Alzheimer’s disease
Authors: Li Hong‐Wei , Zhang Ling , Qin Chuan
Published: December 2019

With the increasingly serious aging of the global population, dementia has already become a severe clinical challenge on a global scale. Dementia caused by Alzheimer's disease (AD) is the most common form of dementia observed in the elderly, but its pathogenetic mechanism has still not been fully elucidated. Furthermore, no effective treatment strategy has been developed to date, despite considerable efforts. This can be mainly attributed to the paucity of animal models of AD that are sufficiently similar to humans. Among the presently established animal models, non‐human primates share the closest relationship with humans, and their neural anatomy and neurobiology share highly similar characteristics with those of humans. Thus, there is no doubt that these play an irreplaceable role in AD research. Considering this, the present literature on non‐human primate models of AD was reviewed to provide a theoretical basis for future research.
Biomimetic Hydrogenation Catalyzed by a Manganese Model of [Fe]‐Hydrogenase
Authors: Pan Hui‐Jie , Hu Xile
Published: December 2019

[Fe]‐hydrogenase is an efficient biological hydrogenation catalyst. Despite intense research, Fe complexes mimicking the active site of [Fe]‐hydrogenase have not achieved turnovers in hydrogenation reactions. Herein, we describe the design and development of a manganese(I) mimic of [Fe]‐hydrogenase. This complex exhibits the highest activity and broadest scope in catalytic hydrogenation among known mimics. Thanks to its biomimetic nature, the complex exhibits unique activity in the hydrogenation of compounds analogous to methenyl‐H4MPT+, the natural substrate of [Fe]‐hydrogenase. This activity enables asymmetric relay hydrogenation of benzoxazinones and benzoxazines, involving the hydrogenation of a chiral hydride transfer agent using our catalyst coupled to Lewis acid‐catalyzed hydride transfer from this agent to the substrates.
Regulating the Coordination Environment of MOF‐Templated Single‐Atom Nickel Electrocatalysts for Boosting CO2 Reduction
Authors: Gong Yun‐Nan , Jiao Long , Qian Yunyang , Pan Chun‐Yang , Zheng Lirong , Cai Xuechao , Liu Bo , Yu Shu‐Hong , Jiang Hai‐Long
Published: December 2019

The general synthesis and control of the coordination environment of single‐atom catalysts (SACs) remains a great challenge. Herein, a general host–guest cooperative protection strategy has been developed to construct SACs by introducing polypyrrole (PPy) into a bimetallic metal–organic framework. As an example, the introduction of Mg2+ in MgNi‐MOF‐74 extends the distance between adjacent Ni atoms; the PPy guests serve as N source to stabilize the isolated Ni atoms during pyrolysis. As a result, a series of single‐atom Ni catalysts (named NiSA‐Nx‐C) with different N coordination numbers have been fabricated by controlling the pyrolysis temperature. Significantly, the NiSA‐N2‐C catalyst, with the lowest N coordination number, achieves high CO Faradaic efficiency (98 %) and turnover frequency (1622 h−1), far superior to those of NiSA‐N3‐C and NiSA‐N4‐C, in electrocatalytic CO2 reduction. Theoretical calculations reveal that the low N coordination number of single‐atom Ni sites in NiSA‐N2‐C is favorable to the formation of COOH* intermediate and thus accounts for its superior activity.
Highly Enantioselective Construction of Strained Spiro[2,3]hexanes through a Michael Addition/Ring Expansion/Cyclization Cascade
Authors: Zhao Chuan‐Gang , Feng Zhi‐Tao , Xu Guo‐Qiang , Gao Ang , Chen Jing‐Wei , Wang Zhu‐Yin , Xu Peng‐Fei
Published: December 2019

We herein report a general organocatalytic enantioselective strategy for the construction of highly strained spiro[2,3]hexane skeletons from methylenecyclopropanes and a broad selection of α,β‐unsaturated aldehydes. The reaction proceeds through a Michael addition followed by ring expansion of methylenecyclopropanes and nucleophilic attack of an enamine to realize the construction of spiro[2,3]hexanes. Key to the success of this approach are the utilization of an electron‐deficient difluoro‐substituted secondary amine catalyst and the intrinsic reactivity of methylenecyclopropanes.
Emergent Deep‐Ultraviolet Nonlinear Optical Candidates
Authors: Mutailipu Miriding , Pan Shilie
Published: December 2019

Advances in the generation of coherent lasers at wavelengths below 200 nm as well as the associated equipment and technologies have greatly spurred the development of nonlinear optical (NLO) materials that are capable of phase‐matching in the deep‐ultraviolet (deep‐UV) spectral regions. However, few crystals can meet the technical demands, and studies to date have focused mainly on finding the next competitive candidates. Consequently, several crystals have emerged that hold great potential for the production of deep‐UV harmonic coherent light, which benefit from newly developed systems with novel NLO‐active units and chromophores. This Review provides a comprehensive overview of the developments of emergent candidates in the field of deep‐UV NLO materials, discussing the recent efforts and active advances in the search for superior systems and in understanding their structure–property relationships. The intention is to provide a clear perspective on the current emergent deep‐UV NLO candidates, and to accelerate the discovery of next candidates with high performances to meet the urgent demands.
Functional Nanoparticles with a Reducible Tetrasulfide Motif to Upregulate mRNA Translation and Enhance Transfection in Hard‐to‐Transfect Cells
Authors: Wang Yue , Tang Jie , Yang Yannan , Song Hao , Fu Jianye , Gu Zhengying , Yu Chengzhong
Published: December 2019

Effective messenger RNA (mRNA) transfection in hard‐to‐transfect cells delivered by vectors is a long‐standing challenge. Now it is hypothesized that the high intracellular glutathione level is associated with suppressed mRNA translation. This theory leads to a new design principle of next‐generation mRNA vectors: nanoparticles with glutathione depletion chemistry upregulate mRNA translation and enhance transfection, which is beneficial for mRNA delivery in hard‐to‐transfect cells in vitro and in vivo.
Effect of water aging on the mechanical properties of flax fiber/bio‐based resin composites
Authors: Kollia Evgenia , Saridaki Xrisoula , Karagiannis Dimitrios , Kostopoulos Vassilis
Published: December 2019

Present work investigates the effect of hydrothermal aging of flax fiber‐reinforced bio‐based epoxy resin laminates on the mechanical and thermomechanical properties of the composites. Three different types of bio‐based resins were used. Plates reinforced with eight layers plain weave flax fibers of 150 g/m2, manufactured using Resin Transfer Molding (RTM), compression molding or autoclave technique depends on type of the resin. One dimensional Fickian behavior shows a good fitting to the experimental data derived from weight measurements. The water uptake at the equilibrium state in the case of 60 °C temperature was slightly greater than that at 40 °C. The mechanical properties after hydrothermal aging show a significant reduction and do not return to their initial values even after the drying process. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48787.
Development and full validation of an LC–MS/MS methodology to quantify capmatinib (INC280) following intragastric administration to rats
Authors: Fan Xiaoguang , Yang Guanghu , Cui Wenjuan , Liu Qin , Zhang Zhaolong , Zhang Zhikun
Published: December 2019

A highly sensitive, specific and simple LC–MS/MS method for quantification of capmatinib (INC280) in rat plasma was presented. The LC–MS/MS method was validated in terms of specificity and selectivity, linearity, accuracy and precision, matrix effect, extraction recovery, dilution integrity, carryover and stability as per the US Food and Drug Administration's bioanalytical method validation guideline. The validated assay was applied for quantification of capmatinib from a pharmacokinetic study in rats following oral administration at the doses of 1.0, 3.0 and 9.0 mg/kg. The calibration curve ranges from 1 to 2000 ng/ml with desirable linearity and r2 > 0.99. The intra‐ and inter‐batch accuracies were within 99.24–103.59 and 97.76–102.83% with coefficients of variation 5.08–7.36 and 3.18–4.99%, respectively. No significant interference was observed by endogenous peak at the retention time of capmatinib and IS. The assay was free from any matrix effect and showed precise recovery across the calibration curve range, and samples were stable under all experimental conditions. The validated assay was successfully applied to analyze plasma samples of pharmacokinetic study in rat to determine the concentration of capmatinib. In summary, a novel method for analyzing capmatinib in rat plasma has been successfully validated and is now being utilized for quantification of capmatinib from pre‐clinical studies.
The relationship between the volume of clinical presentation exposures, hours, and student self‐rated confidence
Authors: Lafave Mark R. , Yeo Michelle
Published: December 2019

Introduction

The relationship between student's self‐rated confidence and competency development is not clearly understood. The purpose of this study was to explore the relationship between confidence, the total number of practical hours, and the volume of clinical presentation (CP) exposures.

Methods

Confidence, practical hours, and the volume of CP exposures were collected over the last two years for thirteen undergraduate athletic therapy students, and a Spearman rho and Wilcoxon rank test were employed.

Results

Confidence grew steadily throughout the two years. Statistically significant relationships emerged between confidence and the volume of CP exposures at various time points.

Discussion

There were three significant findings in this study: (a) Confidence grew steadily over the course of a two‐year period; (b) the volume of CP exposures could influence confidence growth and, thus, may also be a factor to influence competency development over time; and (c) time alone did not influence the growth in confidence.
Synthesis of Iridium Nanocatalysts for Water Oxidation in Acid: Effect of the Surfactant
Authors: Arminio‐Ravelo José Alejandro , Quinson Jonathan , Pedersen Mads A. , Kirkensgaard Jacob J. K. , Arenz Matthias , Escudero‐Escribano María
Published: December 2019

Proton exchange membrane water electrolysers are very promising renewable energy conversion devices to produce hydrogen from sustainable feedstocks. These devices are mainly limited by the sluggish kinetics of the oxygen evolution reaction (OER). Therefore, efficient catalysts in acidic media that allow operating at low overpotential are necessary. Ir‐based nanoparticles are both active and stable for the OER. Surfactants are widely used in the preparation of nanoparticle colloids. A severe drawback for catalysis is the need to remove surfactants by typically costly, hazardous, time and/or energy consuming steps. Herein we present a modified approach of the polyol synthesis that consists of a simple surfactant‐free and NaOH‐free synthesis of Ir nanoparticles in ethylene glycol leading to colloidal nanoparticles of ca. 2.5 nm in diameter. The benefits and drawbacks of the surfactant‐free synthesis are illustrated by comparison with commercial Ir black nanoparticles and Ir nanoparticles obtained using surfactant for the electrocatalytic OER in acidic media.
Influence of Liquid Solutions on the Ionic Conductivity of Li1.3Al0.3Ti1.7(PO4)3 Solid Electrolytes
Authors: Huang Yi , Jiang Yue , Zhou Yuxi , Hu Zhiwei , Zhu Xiaohong
Published: December 2019

Hydrothermal synthesis is used to successfully prepare Li1.3Al0.3Ti1.7(PO4)3 (LATP) solid electrolytes with high lithium‐ion conductivity, typically being 0.213 mS cm−1. The best calcination and sintering temperatures are optimized to be 900 and 1075 °C, respectively. The solvent effects on conductivity and microstructure of LATP in water, ethanol and acetone are investigated by using impedance spectroscopy and scanning electron microscopy. The conductivity of LATP in water reaches 1.167 mS cm−1. In ethanol, the conductivity of LATP is 0.464 mS cm−1. There is no significant change in acetone. The structural stability of LATP after immersing in liquid solutions is verified by X‐ray diffraction and Raman spectroscopy. It is found by infrared spectroscopy that the change in conductivity is related to the adsorbed OH bond, and the reason for the increase in conductivity is discussed.
Sulfur‐Rich Molybdenum Sulfide as an Anode Coating to Improve Performance of Lithium Metal Batteries
Authors: Meyerson Melissa L. , Pandit Anish H. , Weeks Jason A. , Mabayoje Oluwaniyi , Celio Hugo , Stephens Ryan M. , Heller Adam , Mullins C. Buddie
Published: December 2019

In lithium metal batteries (LMBs), the reaction between metallic Li and organic electrolytes consumes both Li and electrolyte, while the inhomogeneity of the resulting solid‐electrolyte interphase (SEI) contributes to inhomogeneous Li deposition. An artificial SEI, made by coating the Li surface with an electronically insulating material, can mitigate problems caused by uncontrolled SEI formation by 1) decreasing reduction of the electrolyte on the surface, and 2) increasing the uniformity of the Li+ flux to the electrode surface, thereby mitigating dendrite growth. In this work, we present a technique for coating the surface of LMB electrodes with sulfur‐rich molybdenum sulfide. This coating acts as an artificial SEI, which improves the coulombic efficiency and cycling stability of the LMBs by improving the reaction kinetics and decreasing the surface area of the exposed Li.
Scholl‐Type Cycloheptatriene Ring Closure of 1,4,9,12‐Tetraarylfenestrindanes: Reactivity and Selectivity in the Construction of Fenestrane‐Based Polyaromatic Saddles
Authors: Wong Wai‐Shing , Lau Wing‐Wa , Li Yuke , Liu Zhifeng , Kuck Dietmar , Chow Hak‐Fun
Published: December 2019

The Scholl‐type cyclodehydrogenation, generating up to four cycloheptatriene rings around a fenestrindane core, leads to novel, saddle‐shaped polyaromatic hydrocarbon derivatives. In this article, we present the results of in‐depth experimental and computational work on the oxidative cyclization of various 1,4,9,12‐tetraarylfenestrindanes. In particular, the kinetic control of the four‐step cyclization of the electronically activated tetrakis(3,4‐dimethoxyphenyl) derivative is elucidated. The reasons for the exclusive emergence of one single among the three possible doubly cyclized intermediates and for the nonappearance of the singly and triply cyclized intermediates are clarified. In addition, the origin of the concomitant bridgehead hydroxylation is studied. The reactivity of a set of fifteen symmetrically and unsymmetrically substituted 1,4,9,12‐tetraarylfenestrindanes towards Scholl‐type cyclodehydrogenation is presented, pinpointing the structural factors that underlie this reaction and demonstrating the potential and limitations of this synthetic approach. A particularly surprising finding of this study is that the electronically nonactivated 1,4,9,12‐tetraphenylfenestrindane can also undergo the fourfold Scholl‐type cyclization process and can be transformed into the parent saddle hydrocarbon.
Structural Insight into Binary Protein Metal–Organic Frameworks with Ferritin Nanocages as Linkers and Nickel Clusters as Nodes
Authors: Gu Chunkai , Chen Hai , Wang Yingjie , Zhang Tuo , Wang Hongfei , Zhao Guanghua
Published: December 2019

Metal–organic frameworks (MOFs) hold great promise for numerous applications. However, proteins, carriers of biological functions in living systems, have not yet been fully explored as building blocks for the construction of MOFs. This work presents a strategy for the fabrication of binary MOFs. Considering octahedral ferritin symmetry, four His2 (His–His) motifs were first incorporated into the exterior surface of a ferritin nanocage near each C4 channel, yielding protein linkers with multiple metal‐binding sites (bisH‐SF). Secondly, by adding nickel ions to bisH‐SF solutions triggers the self‐assembly of ferritin nanocages into a porous 3D crystalline MOF with designed protein lattice, where two adjacent ferritin molecules along the C4 symmetry axes are bridged by four dinuclear or tetranuclear nickel clusters depending on Ni2+ concentration. This work provides a simple approach for precise control over a binary protein–metal crystalline framework, and the resulting MOFs exhibited inherent ferroxidase activity and peroxidase‐like catalytic activity.
Co‐generation of Ammonia and H2 from H2O Vapor and N2 Using a Membrane Electrode Assembly
Authors: Kugler Kurt , Kriescher Stefanie M. A. , Giela Martin , Hosseiny Schwan , Thimm Kristof , Wessling Matthias
Published: December 2019

The direct electrochemical synthesis of NH3 from nitrogen and water vapor without the use of a fossil carbon source is highly desired. This synthesis is a viable option to store energy and produce fertilizer precursors. Here, a new Pt‐free membrane electrode assembly is presented. An electrochemical membrane reactor demonstrates the feasibility of co‐generating NH3 and H2 directly from nitrogen and water vapor at ambient conditions. An unprecedented high NH3‐specific current efficiency of up to 27.5% using Ti as cathodic catalyst is reported. The co‐generation can be tuned by the balance of process parameters.
ERK inhibition effectively overcomes acquired resistance of epidermal growth factor receptor‐mutant non–small cell lung cancer cells to osimertinib
Authors: Li Yiting , Zang Hongjing , Qian Guoqing , Owonikoko Taofeek K. , Ramalingam Suresh R. , Sun Shi‐Yong
Published: December 2019

Background

Osimertinib (AZD9291), a third‐generation, mutation‐selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (EGFR‐TKI), is an approved drug for patients who have non–small cell lung cancer (NSCLC) with activating EGFR mutations or those harboring a resistant T790M mutation. Unfortunately, all patients eventually relapse and develop resistance to osimertinib. The current study addressed whether ERK inhibition exerts effects similar to those produced by MEK inhibition in overcoming acquired resistance to osimertinib.

Methods

Drug effects on cell and tumor growth were assessed by measuring cell number alterations and colony formation in vitro and with xenografts in nude mice in vivo. Apoptosis was assessed with annexin V/flow cytometry and protein cleavage. Protein alterations in cells were detected with Western blot analysis. Gene overexpression and knockout were achieved with lentiviral infection and CRISPR/Cas9, respectively.

Results

The combination of osimertinib with an ERK inhibitor synergistically decreased the survival of osimertinib‐resistant cell lines with enhanced induction of apoptosis and effectively inhibited the growth of osimertinib‐resistant xenografts in nude mice. Moreover, the combination of an MEK or ERK inhibitor with a first‐generation (eg, erlotinib) or second‐generation (eg, afatinib) EGFR‐TKI also very effectively inhibited the growth of osimertinib‐resistant cells in vitro and of tumors in vivo, although these cell lines were cross‐resistant to first‐generation or second‐generation EGFR‐TKIs.

Conclusions

The current findings emphasize the importance of targeting MEK/ERK signaling in maintaining the long‐term benefit of osimertinib through overcoming acquired resistance to osimertinib, warranting further investigation of this therapeutic strategy to improve the therapeutic efficacy of osimertinib in the clinic.
Do we need PD‐L1 as a biomarker for thyroid cytologic and histologic specimens?
Authors: Pusztaszeri Marc P. , Bongiovanni Massimo , Brimo Fadi
Published: December 2019

This editorial introduces the study by Dell’Aquila and colleagues in this edition of Cancer, which suggests that Programmed death‐ligand 1 (PD‐L1) expression in the thyroid gland and on thyroid liquid‐based cytology might represent a marker of malignancy that correlates with papillary thyroid carcinoma, but not with noninvasive follicular thyroid neoplasm with papillary‐like nuclear features, and discusses the potential use of PD‐L1 for thyroid lesions.