bluuebunny/crossref_metadata_2025 huggingface dataset:
Transgenic Medaka Identify Embryonic Periods Sensitive to Disruption of Sex Determination
Authors: Spirhanzlova Petra , Trébulle Pauline , Lallement Justine , Sébillot Anthony , Kanamori Akira , Lemkine Gregory F. , Tindall Andrew J.
Published: January 2020

Gonadal development in medaka (Oryzias latipes) is dependent on the synergy between estrogens and androgens. Disruption of steroid hormone levels can lead to ovo-testis. To determine the sensitive windows for hormonally induced sex reversal in medaka, we developed a novel 42sp50-GFP_ChgH-GFP transgenic medaka line, allowing the identification of female gonadal tissue by fluorescence present in developing oocytes. Germinal transgenesis resulted in a stable line exhibiting a strong green fluorescent protein signal constitutively in the ovaries and in the liver in response to estrogens. The sensitivity of this line to disruption of sex determination following 16-d chronic exposures was in the nanograms per liter range. To identify the developmental period sensitive to exogenous agents, fry were exposed to 24-h pulses of high concentrations of 17β-estradiol (E2) or 5α-dihydrotestosterone (DHT) at various time points between days postfertilization (dpf) 0 and 12. Evaluation of phenotype followed by genotyping at 16 dpf revealed sensitivity to E2 between 1 and 8 dpf as well as 2 periods of susceptibility to DHT between 0 and 1 dpf and 4 and 8 dpf. No phenotypic sex reversal was detected after exposure to DHT or E2 on 11 or 12 dpf. The observed effects persisted to at least 24 dpf. The identified sensitive embryonic time periods for disruption of sex determination will aid future research on sex determination and the development of screening assays using early embryonic life stages. Environ Toxicol Chem 2020;39:842–851. © 2020 SETAC

Abstract

A novel 42sp50-GFP_ChgH-GFP transgenic medaka line was developed allowing the identification of female gonadal tissue by fluorescence present in developing oocytes. Fry were exposed to 24-h pulses of high concentrations of estradiol or dihydrotestosterone at various time points between 0 and 12 day postfertilization to identify developmental time points sensitive to disruption of sex steroid signaling. DHT = dihydrotestosterone; DPF = day postfertilization; E2 = estradiol.
New Insights Into Intestinal Failure–Associated Liver Disease in Children
Authors: Khalaf Racha T. , Sokol Ronald J.
Published: January 2020

Development of intestinal failure–associated liver disease (IFALD) is a common complication of long‐term parenteral nutrition (PN) in children and adults. The molecular and cellular mechanisms and the phases of IFALD are now being delineated. Components of PN lipid emulsions, including plant sterols, interact with hepatic innate immune activation promoted by products of gut bacterial overgrowth/dysbiosis and altered intestinal barrier function (gut‐liver axis) and by episodes of sepsis to cause cholestasis and IFALD. New therapeutic strategies, including modifications of intravenous lipid emulsions to reduce pro‐inflammatory fatty acids and plant sterol content, can lower the risk of IFALD, reverse cholestasis, and reduce complications, although the significance of persisting hepatic fibrosis is unknown. This review will provide an update on advances in the pathogenesis of IFALD, newer therapeutic and preventative strategies, and challenges that confront managing patients with IFALD.
Galectin‐3 mediates pulmonary vascular endothelial cell dynamics via TRPC1/4 under acute hypoxia
Authors: Li Yumei , Chen Xinghe , Zeng Xixi , Chen Shaokun , Yang Xi , Zhang Li
Published: January 2020

Galectin‐3 (Gal‐3) has been implicated in various biological functions, yet little is known about its role in regulating the dynamics of pulmonary vascular endothelial cells. Gal‐3 was shown to be increased in hypoxic model rats by sequencing analysis. We exposed pulmonary vessel endothelial cells (PVECs) to hypoxia or Gal‐3 stimulation, following which cell apoptosis and autophagy were measured with the relevant methods. The results demonstrated that hypoxia elevated nuclear factor‐κB (NF‐κB) activity and Gal‐3 expression. Gla‐3 decreased the expression of Bcl‐2, Alix, Beclin‐1, Atg5, and LC3A/B. The messenger RNA and protein levels of transient receptor potential channel 1/4 (TRPC1/4) and calpain were reduced after Gal‐3 treatment. Gal‐3 also activated protein kinase B/glycogen synthase kinase‐3 β/mammalian target of rapamycin signaling pathways in PVECs. These results suggest that a hypoxia‐mediated increase in Gal‐3 promotes apoptosis and inhibits autophagy by inhibiting the TRPC1/4 pathway and activating the protein kinase B/glycogen synthase kinase‐3 β/mammalian target of rapamycin signaling pathway in PVECs. Furthermore, these results may provide us with a new direction to explore the pathogenesis of pulmonary artery hypertension.
Profiles of immune infiltration in lung adenocarcinoma and their clinical significant: A gene‐expression–based retrospective study
Authors: Chen Genwen , Dong Zhongyi , Wu Dehua , Chen Yuhan
Published: January 2020

Lung cancer is one of the fatal tumors. The tumor microenvironment plays a key role in regulating tumor progression. To figure out the role of tumor microenvironment in lung adenocarcinoma (LUAD), ESTIMATE algorithm was used to evaluate the immune scores in LUAD. Patients with low immune scores had a worse overall survival (OS) compared with high immune scores. Using RNA‐Seq data of 489 patients in The Cancer Genome Atlas (TCGA), differentially expressed genes (DEGs) were identified between high‐ and low‐immune score groups. Based on the DEGs, nine‐gene signature was constructed by the least absolute shrinkage and selection operator Cox regression model in TCGA set. The signature demonstrated significant prognostic value in both TCGA and Gene Expression Omnibus database. Multivariate Cox regression analyses indicated that nine‐genes signature was an independent prognostic factor. Subgroup analysis also revealed a robust prognostic ability of nine‐gene signature. A nomogram with a C‐index of 0.722 had a favorable power for predicting 3‐, 5‐, and 10‐year survival for clinical use by integrating nine‐gene signature and other clinical features. Co‐expression and functional enrichment analysis showed that nine‐gene signature was significantly associated with immune response and provided potential profound molecules for revealing the mechanism of tumor initiation and progression. In conclusion, we revealed the significance of immune infiltration and built a novel nine‐gene signature as a reliable prognostic factor for patients with LUAD.
YY1‐PVT1 affects trophoblast invasion and adhesion by regulating mTOR pathway‐mediated autophagy
Authors: Yang Dongyong , Ding Jinli , Wang Yanqing , Yuan Mengqin , Xian Shu , Zhang Li , Liu Shiyi , Dai Fangfang , Wang Feiyan , Zheng Yajing , Zhao Xin , Liao Shujie , Cheng Yanxiang
Published: January 2020

Insufficient trophoblast invasion is the key factor for the occurrence of recurrent spontaneous abortions (RSA). Our previous studies identified Yin Yang 1 (YY1) as a transcription factor involved in the regulation of trophoblast invasiveness at the maternal–fetal interface. Long noncoding RNAs (lncRNAs) can regulate gene expression and autophagy in many ways. The purpose of this study was to explore the relationship between YY1 and lncRNAs and the mechanism by which lncRNAs affect the biological behavior of trophoblasts. Bioinformatic analysis predicted that YY1 had three binding sites in the plasmacytoma variant translocation 1 (PVT1) promoter region. Chromatin immunoprecipitation experiments and electrophoretic mobility shift assays verified that YY1 can directly bind to the PVT1 promoter. Compared with its expression levels in human placental villi tissue samples from the normal pregnancy group, the PVT1 expression levels were significantly lower in tissues from the RSA group. PVT1 knockdown significantly reduced adhesion, invasion, autophagy, and mTOR expression in HTR‐8/SVneo cells and greatly increased apoptosis in vitro. This study revealed a novel regulatory pathway in which YY1 can act directly on PVT1 promoter to regulate its transcription, which further affects trophoblast invasion and adhesion by regulating autophagy via the mTOR pathway, and these effects might be involved in RSA pathogenesis.
microRNA‐802 accelerates hepatocellular carcinoma growth by targeting RUNX3
Authors: Ni Min , Zhao Yi , Zhang Wen‐Jing , Jiang Yu‐Jie , Fu Hui , Huang Fang , Li Dong‐Jie , Shen Fu‐Ming
Published: January 2020

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Prognosis is often unfavorable. In this study, the effects of microRNA‐802 (miR‐802) on HCC progression were assessed in vivo and in vitro. miR‐802 was found to be significantly upregulated in HCC tumor tissue compared to paired adjacent nontumor tissue. In vitro, transfection with a miR‐802 mimic accelerated SMMC‐7721 cellular proliferation, increased accumulation of the cell‐cycle S‐phase cell populations, as well as cell migration. In vivo injection of a miR‐802 agomir promoted HCC proliferation in nude mice. Targets of miR‐802 were predicted by miRWalk, miRanda, RNA22, and Targetscan. By luciferase reporter assay RUNX3 was identified as a direct target of miR‐802. As judged by western blot analysis, RUNX3 was upregulated when miR‐802 was inhibited. These data demonstrate increased miR‐802 expression in patients with HCC and that miR‐802 overexpression promotes tumor cell growth, in a RUNX3‐dependent manner.
Bubble dynamics and mass transfer characteristics from an immersed orifice plate
Authors: Shi Haojie , Jiang Hong , Liu Yefei , Chen Rizhi
Published: January 2020

BACKGROUND

Bubble dynamics plays an important role in performance enhancement of multiphase reactor. The formation of the bubbles at the orifice is critical for the dynamics of bubbles and the mass transfer process during the rising stage. However, few studies have focused on the detailed changing characteristic of bubble formation and its relationship with mass transfer.

RESULTS

The evolution of the bubble dynamics from millimeter to micrometer‐sized immersed orifice plates is in situ visualized. Bubble inrush is observed from the orifices with diameters below 421 μm, resulting in significant fluctuation on the gas–liquid interface. The base of the leading bubble varies with the orifice diameter. Smaller orifice is preferred to produce more trailing bubbles with smaller size. The inrush time of the trailing bubble is prolonged with decreasing orifice diameter and increasing gas velocity. The inrush time and diameter of the latter trailing bubble are higher than the former at a certain gas velocity. The volumetric mass transfer coefficient (KLa) is obtained by measuring the bubble volume during the rising process using chemical absorption of carbon dioxide (CO2) with sodium hydroxide (NaOH). Increasing gas velocity, decreasing orifice diameter and bubble inrush make an apparent positive impact on the KLa.

CONCLUSIONS

The bubble inrush happens at micrometer orifice. Decreasing orifice diameter and increasing gas velocity are important to intensify oscillation of the leading bubble and increase the frequency of bubbles with high specific interfacial area, which are conducive to the enhancement of the volumetric mass transfer coefficient. © 2020 Society of Chemical Industry
Bounds on the localization number
Authors: Bonato Anthony , Kinnersley William B.
Published: January 2020

We consider the localization game played on graphs, wherein a set of cops attempt to determine the exact location of an invisible robber by exploiting distance probes. The corresponding optimization parameter for a graph G is called the localization number and is written as ζ(G). We settle a conjecture of Bosek et al by providing an upper bound on the chromatic number as a function of the localization number. In particular, we show that every graph with ζ(G) ≤ k has degeneracy less than 3k and, consequently, satisfies χ(G) ≤ 3ζ(G). We show further that this degeneracy bound is tight. We also prove that the localization number is at most 2 in outerplanar graphs, and we determine, up to an additive constant, the localization number of hypercubes.
How Livelihood Assets Contribute to Sustainable Development of Smallholder Farmers
Authors: Li Wenjing , Shuai Chuanmin , Shuai Yu , Cheng Xin , Liu Yue , Huang Fubin
Published: January 2020

There is a knowledge gap and practical demand to understand the relationship between capitals for developing sustainable livelihoods to realize poverty reduction and sustainable development, in particular for the smallholder farmers. This paper intends to make sights into an important livelihood challenge faced by smallholder farmers, which also aims to find out strategy (ies) in accelerating smallholder farmers' poverty reduction and achieving sustainable development. More specifically, we used a hybrid approach by adopting both qualitative and quantitative methods along with the concept of sustainable livelihood approach to reveal six capitals of farmers' household capacity and their potential relationships. Based on an analysis of Grounded Theory for smallholder farmers, we proposed a newly built framework for smallholder farmers' sustainable livelihoods by taking the Psychological capital (Psycap) into the sustainable livelihoods' assets. With a total sample of 796 households representing 26 counties in Three Gorges Reservoir Region (TGRR) in China, we adopted the Structural Equation Modelling using partial least squares (PLS‐SEM) to explore the key factors and key paths affecting smallholder farmers' sustainable livelihoods. Results indicate that Psycap can effectively promote the performance of Human capital (Humcap) and Physical capital (Phycap), with both significant direct and significant indirect effects on sustainable livelihoods; Phycap and Humcap have significant impacts on the new sustainable livelihood index. Finally, this paper proposed corresponding policy recommendations for poverty alleviation and sustainable livelihoods of smallholder farmers. © 2020 John Wiley & Sons, Ltd.
Increase in phenolic compounds of Coriandrum sativum L. after the application of a Bacillus halotolerans biofertilizer
Authors: Jiménez‐Gómez Alejandro , García‐Estévez Ignacio , García‐Fraile Paula , Escribano‐Bailón M Teresa , Rivas Raúl
Published: January 2020

BACKGROUND

There is an urgent need for a new sustainable way of satisfying the increasing demand for food worldwide. One of the main challenges is replacing chemical fertilizers with biofertilizers, which include plant root‐associated beneficial microorganisms. The present study reports, for the first time, the effects of SCCPVE07 bacterial strain with respect to improving not only plant development, but also the nutritional content and bioactive compounds content of Coriandrum sativum L., one of the most economically important crops, even for plant growth under salinity stress.

RESULTS

Innoculated coriander plants (C. sativum L.) showed an increase in potassium, carbon, calcium and iron content. A significant improvement in phenolic compounds contents was also observed. The contents of 5‐O‐caffeoylquinic acid, cinnamic acid, 4‐methoxy‐cinnamic acid hexoside, K‐3‐O rutinoside, Q‐3‐O‐rutinoside, Q‐3‐O‐glucoside and Q‐3‐O‐glucuronide were significantly enhanced. Moreover, an efficient bacterial root colonization and a noted growth promotion were demonstrated. Bacterial genome was sequenced and analysed. Gene coding related to Plant growth promotion (PGP) mechanisms and proteins involved in plant defence from salinity or in the metabolism of phenolic compounds, such as quercetin 2,3‐dioxygenase and phenolic acid decarboxylase, were identified.

CONCLUSION

The results obtained in the present study show, for the first time, the beneficial effects of the inoculation of a bacterial Bacillus halotolerans biofertilizer on coriander crops with respect to increasing the content in bioactive compounds and plant development. © 2020 Society of Chemical Industry
Online high‐pH reversed‐phase liquid chromatography × low‐pH reversed‐phase liquid chromatography tandem electrospray ionization mass spectrometry combined with pulse elution gradient in the first dimension for the analysis of alkaloids in Macleaya cordata (willd.) R. Br
Authors: Hu Deping , Li Yuandong , Zhao Hui , Zhao Yang , Huang Si , Li Juan , Li Zhenjie , Duan Yuanxing , Chen Yingzhuang , Xia Jianjun
Published: January 2020

An online high‐pH reversed‐phase liquid chromatography× low‐pH reversed‐phase liquid chromatography tandem electrospray ionization mass spectrometry combined with pulse elution gradient in the first dimension was constructed to separate and identify alkaloids from Macleaya cordata (willd.) R. Br. The modulation was performed by using a dual second dimensional columns interface combined with a make‐up dilution pump, which is responsible for dilution and neutralization of the first dimensional effluent, and the dual second dimensional columns integrated the trapping and the separation function to reduce the second dimension system dead volume. Taking advantage of the dissociable characteristics of alkaloids, mobile phases with different pH values were applied in the first dimension (pH 9.0) and the second dimension (pH 2.6) to improve the orthogonality of two‐dimension separation. Besides, the pulse elution gradient in first dimension and second dimensional gradient were carefully optimized and much better separation was achieved compared to the separation with the traditional two‐dimensional liquid chromatography approach. Finally, mass measurement was performed for alkaloids in M. cordata (willd.) R. Br. by coupling proposed two‐dimensional liquid chromatography system with triple quadrupole mass spectrometry, and 39 alkaloids were successfully identified by comparing the obtained result with the former reported results.
Ghrelin promotes neural differentiation of adipose tissue‐derived mesenchymal stem cell via AKT/mTOR and β‐catenin signaling pathways
Authors: Liu Gui‐Bo , Pan Yan‐Ming , Liu Yun‐Shuang , Hu Jia‐Hang , Zhang Xiao‐Dong , Zhang Da‐Wei , Wang Ying , Feng Yu‐Kuan , Yu Jian‐Bo , Cheng Yong‐Xia
Published: January 2020

Adipose tissue‐derived mesenchymal stem cells (ADSCs) are multipotent cells that can differentiate into various cell types. This study aimed to investigate the effect of ghrelin on the neural differentiation of rat ADSCs and underlying molecular mechanisms. Rat ADSCs were isolated and third‐passage ADSCs were used in this study. The isolated ADSCs were characterized by flow cytometry analysis for MSCs' surface expression markers as evidenced by positive for CD90, CD44, and CD29 and negative for CD34, CD45, and CD11b/2f/c. The multilineage differentiation of ADSCs was confirmed by adipogenic, osteogenic, and neural differentiation. After induction of neurogenesis, the differentiated cells were identified by development of neuron‐like morphology and expression of neural markers including glial fibrillary acidic protein, Nestin, MAP2, and β‐Tubulin III using immunofluorescence and western blot. Ghrelin concentration dependently elevated the proportion of neural‐like cells and branching dendrites, as well as upregulated the expression of neural markers. Further, the expression of nuclear β‐catenin, p‐GSK‐3β, p‐AKT, and p‐mTOR was increased by ghrelin, indicating an activation of β‐catenin and AKT/mTOR signaling after the ghrelin treatment. Importantly, inhibition of β‐catenin or AKT/mTOR signaling suppressed ghrelin‐induced neurogenesis. Therefore, we demonstrate that ghrelin promotes neural differentiation of ADSCs through the activation of β‐catenin and AKT/mTOR signaling pathways.
Investigations on the oxygen corrosion behaviors of P110 steel in a dynamic experiment simulating nitrogen injection
Authors: Yu Zhiming , Zeng Dezhi , Lin Yuanhua , Zeng Guangwen , Feng Yibo , Ding Baodong , Li Haixia
Published: January 2020

Nitrogen injection is widely applied to enhance oil recovery, but the corrosion failure risk of tubing and casing is increased by residual oxygen in nitrogen. In this study, the corrosion behaviors of P110 steel under dynamic conditions with different oxygen partial pressures (2.5–0.003 MPa) simulating high‐pressure (30 MPa) nitrogen injection were studied. The morphology and composition of corrosion products were characterized by scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and energy‐dispersive X‐ray analysis methods; furthermore, the localized corrosion rate and three‐dimensional surface morphologies were analyzed. The results show that the general corrosion rate decreased significantly with decreasing O2 partial pressure, especially when O2 partial pressure was below 0.5 MPa, and there is a corrosion morphology change from general corrosion to localized corrosion (pitting). Besides, the localized corrosion rates are about 20 times the general corrosion rates. The corrosion products are mainly FeOOH and Fe3O4. In addition, the scales in the intact area are relatively flat and dense, whereas the damaged scales are porous and brittle. Fluid flows not only changed the morphologies and microstructures, resulting in a more protective product layer but also promoted the transfer of the corrosive mediators and affected the development of localized corrosion.
Synthesis of ABC Miktoarm Star Copolymers via Organocatalyzed Living Radical Polymerization
Authors: Ge Yicen , Chen Chen , Sim Xuan Ming , Zheng Jie , Goto Atsushi
Published: January 2020

ABC‐type miktoarm star copolymers are synthesized using a single living radical polymerization (organocatalyzed living radical polymerization) via a “combinatorial” approach. The arm A is poly(butyl acrylate), the arm B is poly(methyl methacrylate), and the arm C encompasses hydrophobic and hydrophilic polyacrylates. A poly(butyl acrylate) with a vinyl chain end (macromonomer) is synthesized. A poly(methyl methacrylate) is subsequently connected to the reactive vinyl group to generate diblock copolymer. From the junction of the diblock copolymer, polymer C grew to yield star copolymers. An amphiphilic star copolymer is also synthesized, and its self‐assembly structure is studied in an aqueous solution.
MHA survey addresses psychological needs of the workforce
Authors: Canady Valerie A.
Published: January 2020

Whether people are happy or sad, satisfied or unsatisfied, the elements that make a company successful in creating mentally healthy workplaces are the same, according to a new workplace survey prepared by Mental Health America (MHA) and released Jan. 27. The survey is MHA's way of exploring factors in work environments that influence employee engagement, workplace stress and mental health, advocates stated.
Existence of smooth solutions for the compressible barotropic Navier‐Stokes‐Korteweg system without increasing pressure law
Authors: Huang Feimin , Hong Hakho , Shi Xiaoding
Published: January 2020

This paper is concerned with a barotropic model of capillary compressible fluids describing the dynamics of a liquid‐vapor mixture with diffuse interphase, in the case of general pressure law including Van der Waals gas. In the Sobolev spaces as close as possible to the physical energy spaces, we first prove local in time existence and uniqueness of the smooth solutions to the Cauchy problem in
, based on the estimates of a linearized system and the contraction mapping principle. Next, we show that there exists a global unique solution for the initial boundary value problem with periodic conditions in torus
, by using a continuation argument of local solution. Notice that it is one of the main difficulties that pressure p is not increasing function of density ρ.
T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T
Authors: Murali‐Manohar Saipavitra , Borbath Tamas , Wright Andrew Martin , Soher Brian , Mekle Ralf , Henning Anke
Published: January 2020

Purpose

Relaxation times can contribute to spectral assignment. In this study, effective T2 relaxation times () of macromolecules are reported for gray and white matter–rich voxels in the human brain at 9.4 T. The of macromolecules are helpful to understand their behavior and the effect they have on metabolite quantification. Additionally, for absolute quantification of metabolites with magnetic resonance spectroscopy, appropriate T2 values of metabolites must be considered. The T2 relaxation times of metabolites are calculated after accounting for TE/sequence‐specific macromolecular baselines.

Methods

Macromolecular and metabolite spectra for a series of TEs were acquired at 9.4 T using double inversion–recovery metabolite‐cycled semi‐LASER and metabolite‐cycled semi‐LASER, respectively. The T2 relaxation times were calculated by fitting the LCModel relative amplitudes of macromolecular peaks and metabolites to a mono‐exponential decay across the TE series. Furthermore, absolute concentrations of metabolites were calculated using the estimated relaxation times and internal water as reference.

Results

The of macromolecules are reported, which range from 13 ms to 40 ms, whereas, for metabolites, they range from 40 ms to 110 ms. Both macromolecular and metabolite T2 relaxation times are observed to follow the decreasing trend, with increasing B0. The linewidths of metabolite singlets can be fully attributed to T2 and B0 components. However, in addition to these components, macromolecule linewidths have contributions from J‐coupling and overlapping resonances.

Conclusion

The T2 relaxation times of all macromolecular and metabolite peaks at 9.4 T in vivo are reported for the first time. Metabolite relaxation times were used to calculate the absolute metabolite concentrations.
A semianalytic time‐resolved poro‐elasto‐plastic model for wellbore stability and stimulation
Authors: Fokker Peter A. , Singh Aditya , Wassing Brecht B.T.
Published: January 2020

Wellbore stability problems and stimulation operations call for models helping in understanding the subsurface behaviour and optimizing engineering performance. We present a fast, iteratively coupled model for the flow and mechanical behaviour that employs a time‐sequential approach. Updates of pore pressure are calculated in a timestepping approach and propagated analytically to updates of the mechanical response. This way, the spatial and temporal evolution of pressure and mechanical response around a wellbore can be evaluated. The sequential approach facilitates the incorporation of pressure diffusion and of time‐dependent plasticity. Also, it facilitates the implementation of permeability evolving with time, due to plasticity or stimulation. The model has been validated by means of a coupled numerical simulator. Its capabilities are demonstrated with a selection of sensitivity runs for typical parameters. Ongoing investigations target geothermal energy operations through the incorporation of thermo‐elastic stresses and more advanced plasticity models.
Effect of microsphere size on the drug release and experimental characterization of an electrospun naringin‐loaded microsphere/sucrose acetate isobutyrate (SAIB) depot
Authors: Zhang Dan , Song Jinlin , Almassri Huthayfa N.S. , Ma Yihui , Zhang Ting , Cheng Yuting , Wu Xiaohong
Published: January 2020

The aims of this study were to prepare different sizes of electrospun naringin‐loaded microspheres (Ng‐ms) and investigate the effects of the particle size of these microspheres on drug release from naringin‐loaded microsphere/sucrose acetate isobutyrate (Ng‐m‐SAIB) hybrid depots to develop an improved drug delivery system for tissue engineering. Different sizes of microspheres were produced using electrospray methods by controlling electrospinning parameters. The Ng‐m‐SAIB depots were prepared by dispersing Ng‐ms in SAIB depots. The morphology and size distributions of the electrospun Ng‐ms were characterized by polarizing microscopy and scanning electron microscopy (SEM). To better understand the release behavior of Ng‐m‐SAIB, the porosity of SAIB depots was measured. Consequently, both small (2.51 ± 0.191 μm) and large (5.03 ± 0.172 μm) microspheres exhibited smooth surfaces and good monodispersity. The initial and long‐term drug release rates of the large microspheres were lower than those of small microspheres. On the first day after 2.5‐μm and 5‐μm Ng‐m‐SAIB depots were produced, the burst release reduced dramatically from 68.79% to 3.30% and from 63.20% to 0.00%, respectively. After 92 days of release, the drug release rate of 5‐μm Ng‐m‐SAIB was still lower than that of 2.5‐μm Ng‐m‐SAIB, with values of 58.54% and 63.93%, respectively. These results demonstrate that drug release from Ng‐m‐SAIB depots can be tailored solely by varying the size of the microspheres and that good drug release behavior occurred.
Comparative study of electrically conductive polymer composites of polyester‐based thermoplastic polyurethane matrix with polypyrrole and montmorillonite/polypyrrole additive
Authors: dos Santos Andrey M. , Merlini Claudia , Ramôa Sílvia D. A. S , Barra Guilherme M. O.
Published: January 2020

Electrically conductive polymer composites were produced by melt mixing technique using polyester‐based thermoplastic polyurethane (TPU) as matrix and polypyrrole (PPy) or montmorillonite/polypyrrole (MMT/PPy) fillers doped with dodecylbenzenesulfonic acid. Composites with different mass concentrations of conductive additives were obtained and characterized, comparing the electrical properties, structure, and morphology of the composites in order to evaluate the effect of conductive filler content and type. The results showed that TPU/MMT/PPy composites have lower percolation threshold and higher electrical conductivity than TPU/PPy. This behavior was attributed to the higher aspect ratio, better dispersion, and greater interaction between nanostructured MMT/PPy and TPU host insulating when compared with neat PPy. In addition, TPU/MMT/PPy composites produced using polyester‐based TPU tend to have better electrical properties than polyether‐based TPU composites due to its higher polarity, increasing the electrical conductivity and reducing the percolation threshold.
Improvement in mechanical properties of NBR/AO60/MMT composites by surface hydrogen bond
Authors: Liang Ping , Yang Shuyan , Ouyang Xing , Hong Haoqun , Jiao Yuanqi
Published: January 2020

It is still a challenge to prepare high performance rubber/MMT composites by one‐pot method without solution. In this work, NBR/AO60/montmorillonite (MMT) (NBR/AM) composites were prepared by mechanical blending method and in‐situ formation of surface hydrogen bond was introduced under vulcanization process. Results showed that the polar parts of melting AO60 could partly intercalate into interlayer of MMT and some parts of melting AO60 molecules were absorbed onto surfaces of MMT particles during the vulcanization process. Subsequently, surface hydrogen bonds were constructed among NBR, AO60, and MMT after natural cooling, as evidenced by FTIR, resulting in more complex morphology and good interfacial adhesion in the NBR/AM composite. Consequently, as compared to NBR/montmorillonite (NBR/M) composite, remarkable improvements were found in mechanical properties and energy dissipation at high temperature of NBR/AM composite, which may provide a new prospect for designing high performance damping materials.
Etiology and management of early pregnancy renal anhydramnios: Is there a place for serial amnioinfusions?
Authors: Jelin Angie C. , Sagaser Katelynn G. , Forster Katherine R. , Ibekwe Tochi , Norton Mary E. , Jelin Eric B.
Published: January 2020

Early pregnancy renal anhydramios (EPRA) comprises congenital renal disease that results in fetal anhydramnios by 22 weeks of gestation. It occurs in over 1 in 2000 pregnancies and affects 1500 families in the US annually. EPRA was historically considered universally fatal due to associated pulmonary hypoplasia and neonatal respiratory failure. There are several etiologies of fetal renal failure that result in EPRA including bilateral renal agenesis, cystic kidney disease, and lower urinary tract obstruction. Appropriate sonographic evaluation is required to arrive at the appropriate urogenital diagnosis and to identify additional anomalies that allude to a specific genetic diagnosis. Genetic evaluation variably includes karyotype, microarray, targeted gene testing, panels, or whole exome sequencing depending on presentation. Patients receiving a fetal diagnosis of EPRA should be offered management options of pregnancy termination or perinatal palliative care, with the option of serial amnioinfusion therapy offered on a research basis. Preliminary data from case reports demonstrate an association between serial amnioinfusion therapy and short‐term postnatal survival of EPRA, with excellent respiratory function in the neonatal period. A multicenter trial, the renal anhydramnios fetal therapy (RAFT) trial, is underway. We sought to review the initial diagnosis ultrasound findings, genetic etiologies, and current management options for EPRA.
Ferroelectric polymers for non‐volatile memory devices: a review
Authors: Li Huilin , Wang Ruopeng , Han Su‐Ting , Zhou Ye
Published: January 2020

Ferroelectric memories have attracted great attention for data storage, and ferroelectric polymers have been widely studied with the development of flexible and wearable devices. The multifunctional capabilities, non‐volatile memory state, low power consumption, long durability, fast switching, chemical stability and mechanical flexibility make them good candidates for various memories, such as ferroelectric tunnel junctions and diodes, ferroelectric capacitors, resistive memories and field‐effect transistors. Here, recent advances in the research of these ferroelectric polymer memories are summarized, and challenges in the development of smart electronics are also discussed. © 2020 Society of Chemical Industry
Does attending a deeper learning school promote student motivation, engagement, perseverance, and achievement?
Authors: Agger Charlotte A. , Koenka Alison C.
Published: January 2020

The evolving economic landscape of the 21st century demands graduates who possess deeper learning (DL) competencies such as critical thinking and collaboration skills. Despite their importance, little work has examined the motivational mechanisms through which DL predicts essential academic outcomes. The current study (N = 1,288) used an ethnically diverse sample of students (53% Hispanic) to explore self‐efficacy and mastery goal orientation as potential mediators of the relationship between (a) enrollment in a DL school and (b) academic engagement, perseverance, and mathematics achievement. Results showed that students who attended DL schools, compared with students in non‐DL schools, reported higher self‐efficacy, mastery goal orientation, and academic engagement. Path analyses revealed that attending a DL school was associated with higher academic engagement and self‐efficacy. However, enrollment in a DL school was not directly related to mathematics achievement. Overall, results provide evidence that attending a DL school can lead to valuable motivation‐ and engagement‐related benefits.
Preparation of Highly Stable and Photoluminescent Cadmium‐Free InP/GaP/ZnS Core/Shell Quantum Dots and Application to Quantitative Immunoassay
Authors: Xu Yanxia , Lv Yanbing , Wu Ruili , Shen Huaibin , Yang Huawei , Zhang Han , Li Jinjie , Li Lin Song
Published: January 2020

Indium phosphide (InP) quantum dots (QDs) are ideal substitutes for widely used cadmium‐based QDs and have great application prospects in biological fields due to their environmentally benign properties and human safety. However, the synthesis of InP core/shell QDs with biocompatibility, high quantum yield (QY), uniform particle size, and high stability is still a challenging subject. Herein, high quality (QY up to 72%) thick shell InP/GaP/ZnS core/shell QDs (12.8 ± 1.4 nm) are synthesized using multiple injections of shell precursor and extension of shell growth time, with GaP serving as the intermediate layer and 1‐octanethiol acting as the new S source. The thick shell InP/GaP/ZnS core/shell QDs still keep high QY and photostability after transfer into water. InP/GaP/ZnS core/shell QDs as fluorescence labels to establish QD‐based fluorescence‐linked immunosorbent assay (QD‐FLISA) for quantitative detection of C‐reactive protein (CRP), and a calibration curve is established between fluorescence intensity and CRP concentrations (range: 1–800 ng mL−1, correlation coefficient: R2 = 0.9992). The limit of detection is 2.9 ng mL−1, which increases twofold compared to previously reported cadmium‐free QD‐based immunoassays. Thus, InP/GaP/ZnS core/shell QDs as a great promise fluorescence labeling material, provide a new route for cadmium‐free sensitive and specific immunoassays in biomedical fields.
Transcription‐inducing activity of natural and synthetic juvenile hormone agonists through the Drosophila Methoprene‐tolerant protein
Authors: Yokoi Taiyo , Nabe Taku , Ishizuka Chiharu , Hayashi Ken'ichiro , Ito‐Harashima Sayoko , Yagi Takashi , Nakagawa Yoshiaki , Miyagawa Hisashi
Published: January 2020

BACKGROUND

Juvenile hormones (JHs) are a class of sesquiterpenoids that play a pivotal role in insect growth and reproduction. Synthetic JH agonists (JHAs), including pyriproxyfen, have been widely used as insecticides to control agricultural pests and disease vectors. The antimetamorphic action of JHAs is mediated by their intracellular receptor, the heterodimer of Methoprene‐tolerant (Met) and Taiman (Tai) proteins. Although a range of bioassay systems has been developed to detect the activity of JHAs, each of these systems has its own drawback(s), such as poor reproducibility, the use of radioactive ligands or the effect of endogenous JH‐signaling factors.

RESULTS

To address these issues, we constructed a new luciferase reporter assay for JHAs in mammalian HEK293T cells transiently transfected with the Drosophila Met and Tai genes. This reporter system gave highly reproducible results and showed nanomolar sensitivity to natural JHs. We then applied this reporter system to a structure–activity relationship (SAR) analysis of 14 natural and synthetic JHAs, leading to identification of the ligand structural factors important for the transcription‐inducing activity.

CONCLUSION

Because this reporter system is not affected by the signaling cascade downstream of the JH receptors, it is suitable for evaluating the intrinsic activity of JHAs. The SAR results obtained in this study therefore provide invaluable information on the rational design of novel JHA insecticides.
Distributed fusion Kalman filtering under binary sensors
Authors: Zhang Yuchen , Chen Bo , Yu Li
Published: January 2020

Binary sensors are special sensors that only transmit one‐bit information at each time and have been widely applied to environmental awareness and medical monitoring. This paper is concerned with the distributed fusion Kalman filtering problem for a class of binary sensor systems. A novel uncertainty approach is proposed to better extract valid information from binary sensors at switching instant. By minimizing a local estimation error covariance, the local robust Kalman estimates are firstly obtained. Then, the distributed fusion Kalman filter is designed by resorting to the covariance intersection fusion criterion. Finally, a blood oxygen content model is employed to show the effectiveness of the proposed methods.
Mitigating evaporation and desiccation cracks in soil with the sustainable material biochar
Authors: Yang Binbin , Xu Ke , Zhang Zhuo
Published: January 2020

Examining soil cracking due to evaporation and desiccation is very important as these two factors affect the permeability of soil in agricultural systems and engineering construction projects. In order to investigate the effects of a sustainable material on the evaporation and cracking of soil, biochar produced through pyrolysis with wheat straw was experimentally examined as an air‐dried additive. Soil was mixed with different amounts of biochar to produce the samples (0, 2.5, 5, 10, and 20% by weight) which were then tested. The cracking properties were subsequently examined based on variations in water loss. The development of the cracks was quantitatively analyzed by using a digital image processing technique, which provided the optimum biochar content that would mitigate evaporation and the development of desiccation cracks. The results were then plotted, and the rate of evaporation of the water in the soil samples with different biochar contents showed an approximately “step” shaped curve, in which three stages could be observed: rapid, slow and constant rates of evaporation. The rate of evaporation quickly declined with a biochar content of 5%. The fractal dimension of the cracks was also reduced with increases in the biochar content, which meant that biochar could inhibit the degree of soil cracking. The optimum biochar content was therefore 5% by weight in this study, which may effectively prevent soil cracking and reduce evaporation, thus reducing landscape irrigation costs in urban infrastructures or irrigation costs in rural agricultural farming.
Reversible Charge Transfer with Single‐Walled Carbon Nanotubes Upon Harvesting the Low Energy Part of the Solar Spectrum
Authors: Menon Arjun , Slominskii Yuri L. , Joseph Jan , Dimitriev Oleg P. , Guldi Dirk M.
Published: January 2020

Here, the ability of a novel near‐infrared dye to noncovalently self‐assemble onto the surface of single‐walled carbon nanotubes (SWCNTs) driven by charge‐transfer interactions is demonstrated. Steady‐state, Raman, and transient absorption spectroscopies corroborate the electron donating character of the near‐infrared dye when combined with SWCNTs, in the form of fluorescence quenching of the excited state of the dye, n‐doping of SWCNTs, and reversible charge transfer, respectively. Formation of the one‐electron oxidized dye as a result of interactions with SWCNTs is supported by spectroelectrochemical measurements. The ultrafast electronic process in the near‐infrared dye, once immobilized onto SWCNTs, starts with the formation of excited states, which decay to the ground state via the intermediate population of a fully charge‐separated state, with characteristic time constants for the charge separation of 1.5 ps and charge recombination of 25 ps, as derived from the multiwavelength global analysis. Of great relevance is the fact that charge‐transfer occurs from the hot excited state of the near‐infrared dye to SWCNTs.
Microlasers from AIE‐Active BODIPY Derivative
Authors: Liu Wangwang , Yu Huakang , Hu Rongrong , Xu Tao , Lun Yipeng , Gan Jiulin , Xu Shanhui , Yang Zhongmin , Tang Ben Zhong
Published: January 2020

Organic microlasers have attracted much attention due to their unique features such as high mechanical flexibility, facile doping of gain materials, high optical quality, simplicity and low‐cost fabrication. However, organic gain materials usually suffer from aggregation‐caused quenching (ACQ), preventing further advances of organic microlasers. Here, a new type of microlaser from aggregation‐induced emission (AIE) material is successfully demonstrated. By introducing a typical noncrystalline AIE material, a high quality microlaser is obtained via a surface tension‐induced self‐assembly approach. Distinct from conventional organic microlasers, the organic luminescent material used here is initially nonluminescent but can shine after aggregation under optical pumping. Further investigations demonstrate that AIE‐based microlasers exhibit advantages to enable much higher doping concentrations, which provides an alternative way to improved lasing performance including dramatically reduced threshold and favorable lasing stability. It is believed that these results could provide a promising way to extend the content of microlasers and open a new avenue to enable applications ranging from chemical sensing to biology.
A New Strategy to Reduce Toxicity of Ethidium Bromide by Alternating Anions: New Derivatives with Excellent Optical Performances, Convenient Synthesis, and Low Toxicity
Authors: Song Yuchen , Xu Lei , Wu Qiong , Xiao Saiyu , Zeng Haixiang , Gong Yanbin , Li Conggang , Cheng Sixue , Li Qianqian , Zhang Liyao , Li Zhen
Published: January 2020

The potential threats of ethidium bromide to laboratory staff have drawn more and more attention. Considering that commercial available substitutes still cannot replace ethidium bromide due to some drawbacks, it can be a better solution by functionalizing directly on ethidium bromide moiety. In this work, ethidium bromide is ameliorated via changing the bromide anion into moieties with more twist structures to prevent the aggregation caused quenching in aggregations, and increase more hydrophobic ability to form nanoparticles in aqueous. The nanoparticles of these probes show negative zeta potential, low toxicity, good photostability, and high sensitivity, both in solution tests and gel electrophoresis experiments. Meanwhile, the weak penetration ability through skin constitutes a dual protection for users. Furthermore, the one step synthesis from commercial available ethidium bromide and the convenient purification also do help to these probes in applications.
Mass production of type IIA dS vacua
Authors: Kallosh Renata , Linde Andrei
Published: January 2020

Abstract

A three-step procedure is proposed in type IIA string theory to stabilize multiple moduli in a dS vacuum. The first step is to construct a progenitor model with a localized stable supersymmetric Minkowski vacuum, or a discrete set of such vacua. It can be done, for example, using two non-perturbative exponents in the superpotential for each modulus, as in the KL model [1]. A large set of supersymmetric Minkowski vacua with strongly stabilized moduli is protected by a theorem on stability of these vacua in absence of flat directions [2]. The second step involves a parametrically small downshift to a supersymmetric AdS vacuum, which can be achieved by a small change of the superpotential. The third step is an uplift to a dS vacuum with a positive cosmological constant using the

$$ \overline{D6} $$

D
6

¯

-brane contribution [3, 4]. Stability of the resulting dS vacuum is inherited from the stability of the original supersymmetric Minkowski vacuum if the supersymmetry breaking in dS vacuum is parametrically small [2, 5].
Chiral Froggatt-Nielsen models, gauge anomalies and flavourful axions
Authors: Bonnefoy Q. , Dudas E. , Pokorski S.
Published: January 2020

Abstract

We study UV-complete Froggatt-Nielsen-like models for the generation of mass and mixing hierarchies, assuming that the integrated heavy fields are chiral with respect to an abelian Froggatt-Nielsen symmetry. It modifies the mixed anomalies with respect to the Standard Model gauge group, which opens up the possibility to gauge the Froggatt-Nielsen symmetry without the need to introduce additional spectator fermions, while keeping mass matrices usually associated to anomalous flavour symmetries. We give specific examples where this happens, and we study the flavourful axion which arises from an accidental Peccei-Quinn symmetry in some of those models. Such an axion is typically more coupled to matter than in models with spectator fermions.