bluuebunny/crossref_metadata_2025 huggingface dataset:
Pregnancy‐specific glycoprotein 9 acts as both a transcriptional target and a regulator of the canonical TGF‐β/Smad signaling to drive breast cancer progression
Authors: Liu Ying‐Ying , Zhang Sa , Yu Tian‐Jian , Zhang Fang‐Lin , Yang Fan , Huang Yan‐Ni , Ma Ding , Liu Guang‐Yu , Shao Zhi‐Ming , Li Da‐Qiang
Published: December 2020

Pregnancy‐specific glycoprotein 9 (PSG9) is a placental glycoprotein essential for the maintenance of normal gestation in mammals. Bioinformatics analysis of multiple publicly available datasets revealed aberrant PSG9 expression in breast tumors, but its functional and mechanistic role in breast cancer remains unexplored. Here, we report that PSG9 expression levels were elevated in tumor tissues and plasma specimens from breast cancer patients, and were associated with poor prognosis. Gain‐ or loss‐of‐function studies demonstrated that PSG9 promoted breast cancer cell proliferation, migration, and invasionin vitro, and enhanced tumor growth and lung colonization in vivo. Mechanistically, transforming growth factor‐β1 (TGF‐β1) transcriptionally activated PSG9 expression through enhancing the enrichment of Smad3 and Smad4 onto PSG9 promoter regions containing two putative Smad‐binding elements (SBEs). Mutation of both SBEs in the PSG9 promoter, or knockdown of TGF‐β receptor 1 (TGFBR1), TGFBR2, Smad3, or Smad4 impaired the ability of TGF‐β1 to induce PSG9 expression. Consequently, PSG9 contributed to TGF‐β1‐induced epithelial‐mesenchymal transition (EMT) and breast cancer cell migration and invasion. Moreover, PSG9 enhanced the stability of Smad2, Smad3, and Smad4 proteins by blocking their proteasomal degradation, and regulated the expression of TGF‐β1 target genes involved in EMT and breast cancer progression, thus further amplifying the canonical TGF‐β/Smad signaling in breast cancer cells. Collectively, these findings establish PSG9 as a novel player in breast cancer progressionvia hijacking the canonical TGF‐β/Smad signaling, and identify PSG9 as a potential plasma biomarker for the early detection of breast cancer.
An insight into small extracellular vesicles: Their roles in colorectal cancer progression and potential clinical applications
Authors: He Xuefeng , Zhong Xinyang , Hu Zijuan , Zhao Senlin , Wei Ping , Li Dawei
Published: December 2020

Colorectal cancer (CRC) is one of the most common cancers and a leading cause of mortality worldwide. Small extracellular vesicles (sEVs) are nano‐sized extracellular vesicles containing a variety of bioactive molecules, such as nucleic acids, proteins, lipids, and metabolites. Recent evidence from CRC has revealed that sEVs contribute to tumorigenesis, progression, and drug resistance, and serve as a tool for “liquid biopsy” and a drug delivery system for therapy. In this review, we summarize information about the roles of sEVs in the proliferation, invasion, migration, epithelial‐mesenchymal transition, formation of the premetastatic niche, and drug resistance to elucidate the mechanisms governing sEVs in CRC and to identify novel targets for therapy and prognostic and diagnostic biomarkers.
The longitudinal negative impact of early stressful events on emotional and physical well‐being: The buffering role of cardiac vagal development
Authors: Patron Elisabetta , Calcagnì Antonio , Thayer Julian F. , Scrimin Sara
Published: December 2020

Early stressful events negatively affect emotional and physical well‐being. Cardiac vagal tone (CVT), which is associated with better emotional and physical well‐being, usually gradually increase in early childhood. Nonetheless, children's CVT developmental trajectories are greatly variable, such that CVT can increase or decrease across the years. The present study examines the longitudinal effects of early stressful events and the role of 4 years CVT developmental trajectory on children's emotional and physical well‐being. Forty‐two 4‐year‐old children were enrolled. Number of stressful events and resting electrocardiogram (ECG) were collected at T1. ECG was registered again after one (T2), two (T3) and three (T4) years. Children's emotional and physical well‐being were assessed at T4 through the Child Health and Illness Profile – Child Edition (CHIP–CE). CVT development was calculated as the angular coefficient, reflecting the developmental trajectory of CVT across the four timepoints. Results yielded that higher experienced stressful events predicted poorer emotional and physical well‐being after 4 years. The interaction between the number of stressful events and CVT development emerged on physical well‐being. Early stressful events negatively affect long‐term children's emotional and physical well‐being while a positive CVT development seems to mitigate the negative effects of early stressful events on physical well‐being.
Extreme evolutionary shifts in developmental timing establish the miniature Danionella as a novel model in the neurosciences
Authors: Conway Kevin W. , M. Kubicek Kole , Britz Ralf
Published: December 2020

Background

Species of Danionella rank among the smallest of all vertebrates and their miniature size is correlated with an extreme case of progenesis, resulting in tiny, transparent sexually mature individuals. Progenesis has affected the entire skeleton of Danionella, in which 60 skeletal elements are absent, including some of the skull roofing bones. This lack of a skull roof combined with the presence of a fully formed hearing and sound producing apparatus has led to Danionella being used as an important model for neurophysiological studies.

Results

Using both rank based and PGi analyses we investigate sequence heterochrony in the development of the skeleton of Danionella dracula and close relatives. Extreme heterochronic shifts affect the appearance of bony elements in Danionella dracula. This includes a delay in the appearance of most chondral skull bones, and a reduction or loss of dermal bones that would otherwise form the skull roof. In contrast, formation of the anterior region of the vertebral column, including the functionally important elements of the Weberian apparatus, is greatly accelerated.

Conclusions

Here we show that the anatomical conditions that favor Danionella for brain research are the result of extreme heterochronic shifts that have acted differentially across the skeleton.
Sympatric divergence of the ergot fungus, Claviceps purpurea, populations infecting agricultural and nonagricultural grasses in North America
Authors: Liu Miao , Shoukouhi Parivash , Bisson Kassandra R. , Wyka Stephen A. , Broders Kirk D. , Menzies Jim G.
Published: December 2020

The ergot diseases of agricultural and nonagricultural grasses are caused by the infection of Claviceps spp. (Hypocreales, Ascomycota) on florets, producing dark spur‐like sclerotia on spikes that are toxic to humans and animals, leading to detrimental impacts on agriculture and economy due to the downgrading of cereal grains, import–export barriers, reduced yield, and ecological concerns. At least seven phylogenetic lineages (phylogenetic species) were identified within the premolecular concept of C. purpurea s.l. (sensu lato) in agricultural areas and vicinities in Canada and the Western United States. Claviceps purpurea s.s (sensu stricto) remained as the most prevalent species with a wide host range, including cereal crops, native, invasive, and weedy grasses. The knowledge on genetic diversity and distribution of C. purpurea s.s. in North America is lacking. The objective of the present study was to shed light on genetic differentiation and evolution of the natural populations of C. purpurea s.s. Multilocus DNA sequences of samples from Canada and the Western USA were analyzed using a phylogenetic network approach, and population demographic parameters were investigated. Results showed that three distinct genetically subdivided populations exist, and the subdivision is not correlated with geographic or host differentiations. Potential intrinsic mechanisms that might play roles in leading to the cessation of gene flows among the subpopulations, that is, mating and/or vegetative incompatibility, genomic adaptation, were discussed. The neutrality of two house‐keeping genes that are widely used for DNA barcoding, that is, translation elongation factor 1‐α (TEF1‐α) and RNA polymerase II second largest subunit (RPB2), was challenged and discussed.
Developments and applications of separation and microfluidics methods coupled to electrospray mass spectrometry in glycomics of nervous system gangliosides
Authors: Sarbu Mirela , Ica Raluca , Zamfir Alina D.
Published: December 2020

Gangliosides are particularly abundant in the nervous system (NS) where their pattern and structure in a certain milieu or a defined region exhibit a pronounced specificity. Since gangliosides are useful biomarkers for diagnosis of NS ailments, a clear‐cut mapping of individual components represents a prerequisite for designing ganglioside‐based diagnostic procedures, treatments, or vaccines. These bioclinical aspects and the high diversity of ganglioside species claim for development of specific analytical strategies. This review summarizes the state‐of‐the‐art in the implementation of separation techniques and microfluidics coupled to MS, which have contributed significantly to the advancement of the field. In the first part, the review discusses relevant approaches based on HPLC MS and CE coupled to ESI MS and their applications in the characterization of gangliosides expressed in healthy and diseased NS. A considerable section is dedicated to microfluidics MS and ion mobility separation MS, developed for the study of brain gangliosidome and its changes triggered by various factors, as well as for ganglioside biomarker discovery in neurodegenerative diseases and brain cancer. In the last part of the review, the benefits and perspectives in ganglioside research of these high‐performance techniques are presented.
Co/Eu co‐doped electron transport layer enhances charge extraction and light absorption for efficient carbon‐based HTM‐free perovskite solar cells
Authors: Zhang Zhenyun , Qiu Fazheng , Shen Tao , Xu Lei , Ma Jingyuan , Qi Junjie
Published: December 2020

Carbon‐based hole‐transport materials (HTM)‐free perovskite solar cells (C‐PSCs) have received increasing attention in photovoltaic fields thanks to the low priced and superior stability. Nevertheless, the C‐PSCs still suffer from low power conversion efficiencies (PCEs) in comparison with conventional PSCs. Here, we report a bimetal Co/Eu co‐doping strategy to modify the electron transportation layer (ETL), simultaneously improving the charge extraction and light absorption and thus the performance of HTM‐free C‐PSCs. Systematic experiments suggest that (i) Co doping passivates the electronic trap‐states in TiO2 ETL, improving the charge transport properties; (ii) Eu doping enhances the photoresponse of PSCs. Combining them together in ETL, all the photovoltaic parameters of C‐PSCs are appreciably enhanced, leading to a PCE leap from 11.12 to 14.06% while keeping a superior device stability. These results may provide possibilities for the exploration of high‐efficiency C‐PSCs by further optimizing ETL with suitable doping.
Definitive intensity‐modulated radiotherapy or surgery for early oral cavity squamous cell carcinoma: Propensity‐score‐matched, nationwide, population‐based cohort study
Authors: Liu Wen‐Chi , Liu Hsueh‐Erh , Kao Yi‐Wei , Qin Lei , Lin Kuan‐Chou , Fang Chih‐Yuan , Tsai Lo‐Lin , Shia Ben‐Chang , Wu Szu‐Yuan
Published: December 2020

Background

No evidence is currently available to estimate the outcomes of intensity‐modulated radiation therapy (IMRT) and surgery for patients with early oral cavity squamous cell carcinoma (E‐OCSCC).

Methods

We recruited patients from the Taiwan Cancer Registry Database who had received a diagnosis of E‐OCSCC. Propensity score matching was performed, and Cox proportional hazards model was used to analyze all‐cause mortality.

Results

In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR) (95% confidence interval [CI]) for surgery compared with definitive IMRT, T2N0M0 compared with T1N0M0, and male patients compared with female patients were 0.303 (0.245, 0.375), 1.340 (1.077, 1.668), and 2.012 (1.432, 2.826), respectively. The aHRs (95% CIs) for age 61 to 70, 71 to 80, and ≧81 years compared with <40 years were 2.984 (1.43, 4.225), 3.353 (2.578, 4.112), and 4.277 (4.104, 5.679), respectively.

Conclusions

For patients with E‐OCSCC, surgery may be considered the first option rather than definitive IMRT.
Maximal aerobic capacity is associated with hippocampal cognitive reserve in older adults with amnestic mild cognitive impairment
Authors: Eisenstein Tamir , Yogev‐Seligmann Galit , Ash Elissa , Giladi Nir , Sharon Haggai , Shapira‐Lichter Irit , Nachman Shikma , Hendler Talma , Lerner Yulia
Published: December 2020

Maximal aerobic capacity (MAC) has been associated with preserved neural tissue or brain maintenance (BM) in healthy older adults, including the hippocampus. Amnestic mild cognitive impairment (aMCI) is considered a prodromal stage of Alzheimer's disease. While aMCI is characterized by hippocampal deterioration, the MAC‐hippocampal relationship in these patients is not well understood. In contrast to healthy individuals, neurocognitive protective effects in neurodegenerative populations have been associated with mechanisms of cognitive reserve (CR) altering the neuropathology‐cognition relationship. We investigated the MAC‐hippocampal relationship in aMCI (n = 29) from the perspectives of BM and CR mechanistic models with structural MRI and a memory fMRI paradigm using both group‐level (higher‐fit patients vs. lower‐fit patients) and individual level (continuous correlation) approaches. While MAC was associated with smaller hippocampal volume, contradicting the BM model, higher‐fit patients demonstrated statistically significant lower correlation between hippocampal volume and memory performance compared with the lower‐fit patients, supporting the model of CR. In addition, while there was no difference in brain activity between the groups during low cognitive demand (encoding of familiar stimuli), higher MAC level was associated with increased cortical and sub‐cortical activation during increased cognitive demand (encoding of novel stimuli) and also with bilateral hippocampal activity even when controlling for hippocampal volume, suggesting for an independent effect of MAC. Our results suggest that MAC may be associated with hippocampal‐related cognitive reserve in aMCI through altering the relationship between hippocampal‐related structural deterioration and cognitive function. In addition, MAC was found to be associated with increased capacity to recruit neural resources during increased cognitive demands.
Changing the landscape of obstetric resident education in low‐ and middle‐income countries using simulation‐based training
Authors: Meza Pamela K. , Bianco Katherine , Herrarte Edgar , Daniels Kay
Published: December 2020

Objective

To evaluate simulation‐based training (SBT) in low‐ and‐middle‐income countries (LMIC) and the long‐term retention of knowledge and self‐efficacy.

Methods

We conducted an SBT course on the management of postpartum hemorrhage (PPH), shoulder dystocia (SD), and maternal cardiac arrest (MCA) in three government teaching hospitals in Guatemala. We evaluated changes in knowledge and self‐efficacy using a multiple‐choice questionnaire for 46 obstetrics/gynecology residents. A paired Student's t test was used to analyze changes at 1 week and 6 months after the SBT.

Results

There was an increase in scores in clinical knowledge of MCA (p < 0. 001, 95% confidence interval [CI] 0.81–1.49) and SD (p < 0.001, 95% CI 0.41–1.02) 1 week after SBT, and a statistically insignificant increase in PPH scores (p = 0.617, 95% CI −0.96 to 0.60). This increase in scores was maintained after 6 months for MCA (p < 0.001, 95% CI 0.69–1.53), SD (p = 0.02 95% CI 0.07–0.85), and PPH (p = 0.04, 95% CI 0.01–1.26). For MCA and SD, the levels of self‐efficacy were increased 1 week following training (p < 0.001, 95% CI 0.83–2.30 and p = 0.008, 95% CI 0.60–3.92, respectively), and at 6 months (p < 0.001, 95% CI 0.79–2.42 and p = 0.006, 95% CI 0.66–3.81, respectively). There was a slight increase in PPH self‐efficacy scores 1 week after SBT (p = 0.73, 95% CI −6.05 to 4.41), maintained after 6 months (p = 0.38, 95% CI −6.85 to 2.85).

Conclusion

SBT was found to be an effective and feasible method to increase short‐ and long‐term clinical knowledge and self‐efficacy of obstetric emergencies in LMIC.
Optimal Dosing of Meropenem in a Small Cohort of Critically Ill Children Receiving Continuous Renal Replacement Therapy
Authors: Tan Wei Wei , Watt Kevin M. , Boakye‐Agyeman Felix , Cohen‐Wolkowiez Michael , Mok Yee Hui , Yung Chee Fu , Chan Yoke Hwee
Published: December 2020

Severe sepsis is an important cause of mortality and morbidity in critically ill children. Meropenem is a broad‐spectrum antibiotic commonly used to treat sepsis. Current meropenem dosage recommendations for children on continuous renal replacement therapy are extrapolated from pharmacokinetic (PK) studies done in adults. Our study aims to determine the optimal dosing in critically ill septic children receiving continuous renal replacement therapy. A prospective single‐center PK study was performed in 9 children in the intensive care unit on continuous renal replacement therapy. Meropenem concentrations were measured from blood and effluent fluid samples. A population PK model was developed using nonlinear mixed‐effects modeling software (NONMEM, AstraZeneca UK Ltd, Cheshire, UK). Monte Carlo simulations were performed. The PK/pharmacodynamic target aimed for plasma concentrations above minimum inhibitory concentration of 4 mg/L for 100% of dosing interval (100%ƒT>MIC). A 2‐compartment model best characterized meropenem PK. Mean (range) clearance and elimination half‐life was 0.091 L/h/kg (0.04–0.157) and 3.9 hours (2.1–7.5), respectively. Dosing of 40 mg/kg/dose every 12 hours over 30 minutes achieved PK/PD target in only 32% while 20 mg/kg every 8 hours over 4 hours or 40 mg/kg every 8 hours over 2 hours achieved 100% ƒT>MIC target for at least 90% of simulated patients.
Regenerative medicine for the hepatobiliary system: A review
Authors: Huang Yu , Miyamoto Daisuke , Hidaka Masaaki , Adachi Tomohiko , Gu Wei‐Li , Eguchi Susumu
Published: December 2020

Liver transplantation, the only proven treatment for end‐stage liver disease and acute liver failure, is hampered by the scarcity of donors. Regenerative medicine provides an alternative therapeutic approach. Tremendous efforts dedicated to liver regenerative medicine include the delivery of transplantable cells, microtissues, and bioengineered whole livers via tissue engineering and the maintenance of partial liver function via extracorporeal support. This brief review summarizes the current status of regenerative medicine for the hepatobiliary system. For liver regenerative medicine, the focus is on strategies for expansion of transplantable hepatocytes, generation of hepatocyte‐like cells, and therapeutic potential of engineered tissues in liver disease models. For biliary regenerative medicine, the discussion concentrates on the methods for generation of cholangiocyte‐like cells and strategies in the treatment of biliary disease. Significant advances have been made in large‐scale and long‐term expansion of liver cells. The development of tissue engineering and stem cell induction technology holds great promise for the future treatment of hepatobiliary diseases. The application of regenerative medicine in liver still lacks extensive animal experiments. Therefore, a large number of preclinical studies are necessary to provide sufficient evidence for their therapeutic effectiveness. Much remains to be done for the treatment of hepatobiliary diseases with regenerative medicine.
Preparation of novel symmetrical bistetrazole‐carbazole derivatives through a one‐pot Ugi‐azide reaction
Authors: Rahimi Shahnaz , Ghandi Mehdi
Published: December 2020

A series of new symmetrical tetrazole‐based carbazole derivatives starting from the initially generated 3,6‐diformyl‐N‐alkylcarbazoles were successfully synthesized through a one‐pot Ugi‐azide reaction in moderate to high yields. Simplicity, easily accessible chemicals, mild reaction conditions, and fast separation of the products with the formation of bistetrazole‐based carbazole derivatives in one step are some advantages of this method. The structure of the products was characterized and confirmed by using spectroscopic techniques such as 1H NMR, 13C NMR, FT‐IR, and MS spectroscopy.
Atrial fibrillation and the risk of 30‐day incident thromboembolic events, and mortality in adults ≥ 50 years with COVID‐19
Authors: Harrison Stephanie L. , Fazio‐Eynullayeva Elnara , Lane Deirdre A. , Underhill Paula , Lip Gregory Y. H.
Published: December 2020

Background

There are limited data on the outcomes of adults with coronavirus disease 2019 (COVID‐19) and atrial fibrillation (AF). The objectives were to (i) examine associations between AF, 30‐day thromboembolic events and mortality in adults with COVID‐19 and (ii) examine associations between COVID‐19, 30‐day thromboembolic events and mortality in adults with AF.

Methods

A study was conducted using a global federated health research network. Adults aged ≥50 years who presented to 41 participating healthcare organizations between 20 January 2020 and 1 September 2020 with COVID‐19 were included.

Results

For the first objective, 6589 adults with COVID‐19 and AF were propensity score matched for age, gender, race, and comorbidities to 6589 adults with COVID‐19 without AF. The survival probability was significantly lower in adults with COVID‐19 and AF compared to matched adults without AF (82.7% compared to 88.3%, Log‐Rank test P < .0001; Risk Ratio (95% confidence interval) 1.61 (1.46, 1.78)) and risk of thromboembolic events was higher in patients with AF (9.9% vs 7.0%, Log‐Rank test P < .0001; Risk Ratio (95% confidence interval) 1.41 (1.26, 1.59)). For the second objective, 2454 adults with AF and COVID‐19 were propensity score matched to 2454 adults with AF without COVID‐19. The survival probability was significantly lower for adults with AF and COVID‐19 compared to adults with AF without COVID‐19, but there was no significant difference in risk of thromboembolic events.

Conclusions

AF could be an important risk factor for short‐term mortality with COVID‐19, and COVID‐19 may increase risk of short‐term mortality amongst adults with AF.
Simulation of catalytic toluene alkylation with methanol in fixed‐bed reactors
Authors: Fan Zong‐Liang , Su Xin , Wang Dong‐Liang , Zhang Dong‐Qiang , Duan Run‐Hao , Yang Yong
Published: December 2020

Toluene alkylation with methanol could serve as a green “molecular engineering” to produce para‐xylene (PX). However, the conversion and para‐selectivity are the key index to the application of this technology. Based on the reaction network and kinetics, the fixed‐bed models were introduced to analyze and optimize the para‐selectivity at reactor level. After the validation with the experimental results, the analysis of reaction kinetics showed that increasing temperature not only improves the main reaction rate, toluene conversion, and para‐selectivity, but also inhibits the competitiveness of methanol autocatalytic reaction, while higher feed molar ratio of toluene to methanol will suppress the olefins formation but reduce the conversion and promote the polymethylation process with a sharper temperature rise. Then, the one‐ and three‐dimensional model demonstrated that the conditions of 500‐520°C, feed molar ratio of 2‐3 would be favorable to the para‐selectivity, and keeping the wall 20‐30°C above the inlet temperature is beneficial for conversion, selectivity, and temperature control. These results have certain guiding value for the choice of reactor condition and further reactor design.
Community diversity metrics, interactions, and metabolic functions of bacteria associated with municipal solid waste landfills at different maturation stages
Authors: Sekhohola‐Dlamini Lerato , Selvarajan Ramganesh , Ogola Henry Joseph Odour , Tekere Memory
Published: December 2020

Municipal landfills are hot spots of dynamic bioprocesses facilitated by complex interactions of a multifaceted microbiome, whose functioning in municipal landfills at different maturing stages is poorly understood. This study determined bacterial community composition, interaction conetworks, metabolic functions, and controlling physicochemical properties in two landfills aged 14 and 36 years. High throughput sequencing revealed a similar distribution of bacterial diversity, evenness, and richness in the 14‐ and 36‐year‐old landfills in the 0–90 cm depth. At deeper layers (120–150 cm), the 14‐year‐old landfill had significantly greater bacterial diversity and richness indicating that it is a more active microcosm than the 36‐year‐old landfill, where phylum Epsilonbacteraeota was overwhelmingly dominant. The taxonomic and functional diversity in the 14‐year‐old landfill was further reflected by the abundant presence of indicator genera Pseudomonas,Lutispora,Hydrogenspora, and Sulfurimonas coupled with the presence of biomarker enzymes associated with carbon (C), nitrogen (N), and sulfur (S) metabolism. Furthermore, canonical correspondence analysis revealed that bacteria in the 14‐year‐old landfill were positively correlated with high C, N, S, and phosphorus resulting in positive cooccurrence interactions. In the 36‐year‐old landfill, negative coexclusion interactions populated by members of N fixing Rhizobiales were dominant, with metabolic functions and biomarker enzymes predicting significant N fixation that, as indicated by interaction network, potentially inhibited ammonia‐intolerant bacteria. Overall, our findings show that diverse bacterial community in the 14‐year‐old landfill was dominated by copiotrophs associated with positive conetworks, whereas the 36‐year‐old landfill was dominated by lithotrophs linked to coexclusion interactions that greatly reduced bacterial diversity and richness.
Image deblurring using adaptive fractional‐order shock filter
Authors: Irandoust‐pakchin Safar , Babapour Shahab , Lakestani Mehrdad
Published: December 2020

In this paper, a novel image enhancement model based on shock filter for image deblurring is proposed in three cases. For the weight of shock filter, the fractional‐order derivative of initial blurry image is used. This fractional‐order weight can be adjusted adaptively according to the gradient of blurred image. Compared with the traditional integer‐order shock filter, the proposed model creates less staircase effect, whereas the enhancement and deblurring of the resulted images are efficiently good. Stability properties of the proposed method are studied theoretically, and also to show the validity of stability studies results, some numerical experiments are presented. The three cases of proposed method are compared with together and with other methods. Different test images are used to show the validity of these cases. Numerical experiments confirm the efficiency of these cases.
Reduced dimensionality optimizer for efficient design of wideband millimeter‐wave 3D metamaterial GRIN lenses
Authors: Garcia Nicolas , Chisum Jonathan
Published: December 2020

In this article we present a method for the rapid design of wideband, high efficiency metamaterial GRIN lenses with rotational symmetry. The method achieves rapid optimization by reducing the number of optimized parameters while maintaining wideband impedance matching for high aperture efficiency. For rotationally symmetric lenses with isotropic GRIN media it is sufficient to design a two‐dimensional (2D) cross section. By using intrinsically matched unit‐cells which prescribe a permittivity gradient along the axis of beam propagation the optimizer only needs to define the transverse permittivity gradient along a line, reducing the design domain from three dimensions (3D) to a single dimension (1D). At each step of the optimizer a 2D finite‐difference‐time‐domain code rapidly solves each realization of the GRIN lens cross‐section across a wide bandwidth. We demonstrate the proposed method by optimizing and fabricating a 4‐inch GRIN lens which achieves 60%–65% measured aperture efficiency from 26 to 40 GHz. The prototype lens provides a high‐efficiency aperture for Ka‐band satcom and 5G millimeter‐wave bands and the approach is suitable for higher future millimeter‐wave bands in 6G and beyond networks.
Hierarchical porous N,S‐codoped carbon material derived from halogenated polymer for battery applications
Authors: Dang Qidong , Zhang Xu , Liu Wenqiang , Wang Yaqun , Dou Gang , Zhang Han , Zhang Guoxin
Published: December 2020

Herein, a hierarchically porous N, S‐co‐doped carbon material (named as NS‐C) has been efficiently fabricated from halogenated polymer to meet the targets of the low‐cost anode and cathode materials for Li‐based batteries. Thanks to its large N (∼5.4 at.%) and S (∼1.1 at.%) contents, large specific surface area (∼1510 m2 g–1), and beneficial pore hierarchy, the NS‐C exhibits superior bifunctional performance as anode material and S host for Li‐S cathode. The NS‐C/sulfur composite (named as S@NS‐C) delivers a large capacity of 1125 mAh g–1 at 0.1 C and maintains a capacity of 401 mAh g–1 at 5 C. A continuous long‐term use for 200 cycles at 2 C achieves large capacity retention of 80.5%. Furthermore, the NS‐C can also serve as anode material for stable Li‐ion storage with large capacity, showing very limited capacity fading for over 1000 cycles at both 0.1 and 1.0 A g–1. Moreover, considering the huge amount of halogenated polymer plastic wastes buried, burned, or discarded in the environments, our developed route of simple conversion of halogenated polymers into functional carbon materials for Li‐ion battery anode and S host for Li‐S battery cathode is advantageous for both environmental protection and Li‐based battery industry.
The marketplace dilemma: Selling to the marketplace vs. selling on the marketplace
Authors: Yenipazarli Arda
Published: December 2020

Online marketplaces are rapidly shifting the trajectory of the e‐commerce landscape. Brand manufacturers are starkly more dependent on online marketplaces, and for most brands, marketplace presence is not optional but mandatory. At this point, brand executives face a pivotal question in addressing their marketplace presence: What product selling (or distribution) approach should be adopted to leverage this channel for their brand? At its core, there are effectively two options offered to brand executives: selling to the online marketplace (as a 1p vendor); and selling on the marketplace platform (as a 3p seller). Whereas the conventional 1p vendor model is quintessentially the entry point to an online marketplace, some brand manufacturers migrate to the 3p seller model. Many others, however, avoid pulling the 3p trigger. In this paper, we address these two options a brand manufacturer has for selling (or allowing sales of) his product on a marketplace. On the grounds that online marketplaces retain brands at distinct price/quality tiers so as to be both comprehensive and robust, we propose a model of competition between two brand manufacturers whose products (in a category) are vertically differentiated on a quality/performance attribute and a convex marginal production cost is incurred for providing the higher quality. Given there is no single selling strategy on a marketplace that is ideal for all brand manufacturers and strategies would work the best under different market and competitive conditions, we investigate the impact of where a brand stands (vis‐á‐vis his competitor) on the two dimensions of a product‐attribute space on the transitions of 1p brands to 3p sellers on the marketplace platform. We also extend the analysis to the setting where an online retailer decides on whether or not to add a marketplace platform to her existing online marketplace and (if so) on the referral fee percentage at which the product category would be listed.
An optimized compact reconstruction weighted essentially non‐oscillatory scheme for advection problems
Authors: Liu Bijin , Yu Ching‐Hao , An Ruidong
Published: December 2020

This paper presents an optimized compact reconstruction weighted essentially non‐oscillatory scheme without dissipation errors (OCRWENO‐LD) for solving advection problems. The construction procedure of this optimized scheme without dissipation errors is as follows: (1) We first design a high‐order compact difference scheme with four general weights connecting four low‐order compact stencils. The four general weights are determined by applying the Taylor series expansions. (2) These general weights are optimized to the new weights which are derived from the WENO concept and modified wavenumber approach. (3) No dissipation errors are found for the developed OCRWENO‐LD scheme through Fourier analysis. The proposed high‐resolution scheme demonstrates its capability in exhibiting high‐accuracy in smooth regions and avoiding numerical oscillation near discontinuities when simulating the wave equation, Burgers' equation, one‐dimensional Euler equation, porous medium equation, and convection–diffusion Buckley–Leverett equation.
Late mortality from other diseases following childhood cancer in Australia and the impact of intensity of treatment
Authors: Youlden Danny R. , Walwyn Thomas S. , Cohn Richard J. , Harden Hazel E. , Pole Jason D. , Aitken Joanne F.
Published: December 2020

Background

People who receive treatment for cancer during childhood often experience subsequent complications of therapy, known as late effects, which can lead to an increased risk of death.

Procedure

Using deidentified population‐based data from the Australian Childhood Cancer Registry for children aged 0‐14 diagnosed with cancer during the period 1983‐2011 and who survived for a minimum of 5 years, we examined disease‐related deaths (other than cancer recurrence or second primary cancers) that occurred up to 31 December 2016. Risk of death relative to the general population was approximated using standardised mortality ratios (SMRs). Treatment received was stratified according to the intensity of treatment rating, version 3 (ITR‐3).

Results

During the study period, 82 noncancer disease‐related deaths were recorded among 13 432 childhood cancer survivors, four times higher than expected (SMR = 4.43, 95% CI = 3.57‐5.50). A clear link to treatment intensity was observed, with the relative risk of noncancer disease‐related mortality being twice as high for children who underwent ‘most intensive’ treatment (SMR = 5.94, 95% CI = 3.69‐9.55) compared to the ‘least intensive’ treatment group (SMR = 2.98, 95% CI = 1.42‐6.24; Ptrend = .01). Thirty‐year cumulative mortality from noncancer disease‐related deaths was estimated at 1.4% (95% CI = 1.1‐1.9) after adjusting for competing causes of death such as cancer, accidents, or injuries.

Conclusions

Although childhood cancer survivors are at increased relative risk of death from noncancer diseases, particularly those who undergo more intensive treatment, the cumulative mortality within 30 years of diagnosis remains small. Knowledge of late effects can guide surveillance of survivors and treatment modification, without wanting to compromise the high rates of survival.
Experimental and statistical analysis of strength of glass fiber reinforced polymer composite for different fiber architecture
Authors: Jariwala Hitesh , Jain Piyush , Maisuriya Vatsal
Published: December 2020

In the present study, the effect of fiber architecture on mechanical properties of E‐glass fiber reinforced polymer composite has been investigated experimentally. The influence of fiber volume fraction on strength of composite has also been predicted using second order polynomial regression models. The glass fibers were arranged in different architecture like unidirectional continuous, unidirectional discontinuous, short randomly oriented, transversely aligned, and woven for preparation of composites. The tensile and flexural tests were performed as per ASTM D3039 and ASTM D790, respectively. The experimental results of tensile and flexural properties of composites have been discussed. Results predicted by the regression models are in good agreement with experimental results which indicate the goodness of fit and the models are statistically significant.
Gene‐targeted molecular phylogeny, phytochemical analysis, antibacterial and antifungal activities of some medicinal plant species cultivated in Egypt
Authors: Omar Hanaa S. , Elsayed Tarek R. , Reyad Nour El‐Houda A. , Shamkh Israa. M. , Sedeek Mohamed S.
Published: December 2020

Introduction

Medicinal plants have been used in healthcare since time immemorial, as have their therapeutic activities and the production of plant‐based medicines.

Objectives

This study aims to use gene‐targeted molecular markers for genetic diversity analysis of 16 medicinal plants. Besides, phytochemical analysis antibacterial and antifungal activities of some medicinal plant extracts commonly used in Egypt are compared to major compounds.

Methods

DNA‐based classification of 16 medicinal species using Conserved DNA‐Derived Polymorphism (CDDP) and Start Codon Targeted (SCoT) primers. Three species representing three orders (Pelargonium graveolens, Matricaria chamomilla, and Hyoscyamus muticus were analysed [high‐performance liquid chromatography (HPLC), gas chromatography‐mass spectrometry (GC‐MS)] and evaluated for their antibacterial and antifungal activities against (Escherichia coli O157: H7 ATCC 93111, Salmonella typhimurium ATCC 14028, Methicillin‐resistant Staphylococcus aureus (MRSA) ATCC 43300, Bacillus ceruse ATCC 33018, and Sclerotinia sclerotiorum in comparison with some of their antimicrobial components.

Results

Our results revealed 309 and 349 polymorphic bands with 100% polymorphism. Among them, 51 and 57 were unique loci for CDDP and SCoT, respectively. The 16 species were categorised into three groups depending on the similarity matrix. The results of antibacterial and antifungal activities revealed that Pelargonium oil showed significant antifungal and antibacterial activities against the tested pathogens. Gallic acid severely reduced all tested bacteria's growth, but atropine severely reduced the growth of the B. ceruse only. Molecular modelling revealed their activity against sclerotium development.

Conclusion

The gene‐targeted marker techniques were highly useful tools for the classification of the 16 medicinal plant species, despite displaying high similarities at morphological and phytochemical analyses but, have antifungal and antibacterial activities.
Direct current gas–liquid phase pulsed plasma polymerization of polypyrrole under atmospheric pressure
Authors: Wang Kai , Tan Huijun , Lin Yingying , Diono Wahyu , Zhao Yaping , Goto Motonobu
Published: December 2020

In this study, an atmospheric‐pressure nanosecond impulse discharge initiated above the pyrrole microemulsion surface is applied to polymerize pyrrole and obtain a polypyrrole film. The films obtained under different number of plasma discharge times and duration of argon gas input time are investigated using a field emission scanning electron microscope. Results show that the roughness and thickness of the polypyrrole film can be tuned by controlling discharge times and the gas feed time. Four‐point sheet resistance measurements of the films reflect that those with a smoother and more complete surface have better electrical conductivity. The films are identified as polypyrrole by Fourier‐transform infrared spectroscopy, X‐ray diffraction, and X‐ray photoelectron spectrometry. Also, N2 is a critical factor in polymerizing polypyrrole and the gas–liquid plasma polymerization mechanism, which has three steps, is discussed.
Physiologically‐Based Pharmacokinetic Modeling of the Drug–Drug Interaction of the UGT Substrate Ertugliflozin Following Co‐Administration with the UGT Inhibitor Mefenamic Acid
Authors: Callegari Ernesto , Lin Jian , Tse Susanna , Goosen Theunis C. , Sahasrabudhe Vaishali
Published: December 2020

The sodium‐glucose cotransporter 2 inhibitor ertugliflozin is metabolized by the uridine 5'‐diphospho‐glucuronosyltransferase (UGT) isozymes UGT1A9 and UGT2B4/2B7. This analysis evaluated the drug–drug interaction (DDI) following co‐administration of ertugliflozin with the UGT inhibitor mefenamic acid (MFA) using physiologically‐based pharmacokinetic (PBPK) modeling. The ertugliflozin modeling assumptions and parameters were verified using clinical data from single‐dose and multiple‐dose studies of ertugliflozin in healthy volunteers, and the PBPK fraction metabolized assignments were consistent with human absorption, distribution, metabolism, and excretion results. The model for MFA was developed using clinical data, and in vivo UGT inhibitory constant values were estimated using the results from a clinical DDI study with MFA and dapagliflozin, a UGT1A9 and UGT2B4/2B7 substrate in the same chemical class as ertugliflozin. Using the verified compound files, PBPK modeling predicted an ertugliflozin ratio of area under the plasma concentration–time curves (AUCR) of 1.51 when co‐administered with MFA. ClinicalTrials.gov identifier: NCT00989079.
Novel Tubular Structures with Negative Poisson's Ratio and High Stiffness
Authors: Ruan Haifeng , Ning Jiajie , Wang Xin , Li Dong
Published: December 2020

A stiff tubular cellular structure topology is designed by alternatively indenting rectangular contour patterns on the cell ribs. Modified topologies can be obtained by tailoring the geometric parameters. The Poisson's ratios and elastic moduli of the proposed tubular structures with various geometric parameters are determined using finite element method (FEM). Results show that the minimum Poisson's ratio of the proposed structures can reach −0.28. The unit cell topology and orientation can significantly affect the structures deformation behaviors. The structures exhibit mixed mode of bending‐ and stretching‐dominated deformation responses, and show improved specific elastic moduli compared with traditional open‐cell stochastic foams with positive Poisson's ratios. 3D‐printed samples with identical geometric variables to those of the FE models are fabricated, and their Poisson's ratios and stress–strain relationships are determined experimentally, and compared with simulation results. Excellent agreement is achieved between measurements and simulations. The design concept proposed here can be optimized for specific applications via geometric parameters manipulation.
Bypassing the multireference character of singlet molecular oxygen, part 1:1,4‐cyclo‐addition
Authors: Jespersen Malte F. , Jørgensen Solvejg , Johnson Matthew S. , Mikkelsen Kurt V.
Published: December 2020

Modeling reactions involving singlet molecular oxygen (O2 [1Δg]) is challenging because the degeneracy of the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO and LUMO) orbitals of oxygen causes a significant multireference character. Within the limit that singlet‐singlet near‐degeneracy disappears in the transition state, it would be possible to bypass singlet oxygen's multireference character by simply adding the experimentally determined singlet/triplet splitting (22.5 kcal/mol) to the energy of the triplet ground state of molecular oxygen. This method is tested by calculating rate constants for the reactions of singlet molecular oxygen with furan, 2‐methylfuran, 2,5‐dimethylfuran, pyrrole, 2‐methylpyrrole, 2,5‐dimethylpyrrole, and cyclopentadiene using transition state theory. We find that the reaction rate coefficients are within a factor of 15 of experimentally determined rate constants, indicating an error in the barrier energy of roughly 3 kcal/mol. Furthermore, we find that energy refinement at the CCSD(T)‐F12 level of theory is crucial to achieving accurate results. We conclude that, based on a comparison with an experiment, this approximation is valid to some degree and can be used for other systems involving the 1,4‐cyclo‐addition of singlet oxygen.
It did not work? Unlearn and try again—Unlearning success and failure beliefs in changing environments
Authors: Martignoni Dirk , Keil Thomas
Published: December 2020

Research Summary

When organizational environments change, experience, and organizational beliefs are often devalued and may become an obstacle to organizational adaptation. The literature on unlearning suggests organizations can overcome this problem by unlearning. However, prior work focuses mostly on unlearning of what has worked in the past (success beliefs) and neglects unlearning of what did not work (failure beliefs). We examine the differences in unlearning these two types of beliefs and their implications for learning and adaptation under environmental change. Using a simulation model, we find that (a) the implications of unlearning success and failure beliefs exhibit fundamentally different temporal dynamics because their underlying mechanisms are different, (b) organizations can often gain more from unlearning failure beliefs, and (c) unlearning failure beliefs is the more robust strategy.

Managerial Summary

In our study, we investigate the implications of unlearning for an organization's ability to adapt to a (more or less) changing environment. We show that organizations should unlearn selectively because unlearning success beliefs (i.e., beliefs about what has worked in the past) have different implications from unlearning of failure beliefs (i.e., beliefs what has not worked in the past). Most importantly, our study suggests that organizations should focus on unlearning failure rather than success beliefs, in particular, given the difficulties of unlearning old (success) beliefs and the problems associated with knowing when old beliefs turned obsolete by environmental changes. In focusing on unlearning failure beliefs, organizations also pursue a less risky strategy than with unlearning success beliefs.
Dimensionality and Defect Engineering Using Fluoroaromatic Cations for Efficiency and Stability Enhancement in 3D/2D Perovskite Photovoltaics
Authors: Lee Hock Beng , Kumar Neetesh , Tyagi Barkha , Ko Keum-Jin , Kang Jae-Wook
Published: December 2020

State‐of‐the‐art perovskite solar cells (PSCs) based on three‐dimensional (3D) films have achieved high power conversion efficiencies (PCEs), but are relatively fragile in high‐temperature and humid environments. This shortcoming must be addressed before PSCs can be fully commercialized. Herein, the use of a fluorinated aromatic organic spacer cation, 4‐fluoro‐phenethylammonium iodide (FPEAI), to fine‐tune the dimensionality and surface morphology of perovskite films is demonstrated. Surface treatment with FPEAI can lead to in situ formation of a two‐dimensional (2D) (FPEA)2PbI4 perovskite capping layer atop a 3D perovskite film, producing novel 3D/2D interface in perovskite films. Simultaneously, FPEAI treatment can induce a novel grain‐boundary passivation effect on the film surface, which helps to suppress undesirable charge recombination. After FPEAI treatment, standard (0.09 cm2) and large‐area (2.00 cm2) PSCs achieve PCEs of 20.53% and 16.82%, respectively. The FPEAI‐treated PSCs also demonstrate superior air‐ and photo‐stability due to the hydrophobic (FPEA)2PbI4 capping layer that reduces moisture ingress into perovskite structures. Furthermore, a 11.2 cm2 large FPEAI‐treated PSC module with a PCE of 13.66% are successfully fabricated. FPEAI passivation is a facile strategy to produce 3D/2D multi‐dimensional PSCs with superior performance and stability.