bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of graphene reinforcement in conductive polymer: Synthesis and characterization
Authors: Dhakal Dilli R. , Lamichhane Pralhad , Mishra Kunal , Nelson Toby L. , Vaidyanathan Ranji K.
Published: May 2019

Lightweight conductive polymers are considered for lightning strike mitigation in composites by synthesizing intrinsically conductive polymers (ICPs) and by the inclusion of conductive fillers in insulating matrices. Conductive films based on polyaniline (PANI) and graphene have been developed to improve through‐thickness conductivity of polymer composites. The result shows that the conductivity of PANI enhanced by blending polyvinylpyrrolidone (PVP) and PANI in 3:1 ratio. Conductive composite thin films are prepared by dispersing graphene in PANI. The conductivity of composite films was found to increase by 40× at 20 wt% of graphene inclusion compared with PVP and PANI blend. Fourier‐transform‐infrared (FTIR) spectra confirmed in situ polymerization of the polymer blend. The inclusion of graphene also exhibits an increase in Tg by 21°C. Graphene additions also showed an increase in thermal stability by approximately 148°C in the composite films. The mechanical result obtained from DMA shows that inclusion of graphene increases the tensile strength by 48% at 20 wt% of graphene reinforcement. A thin, highly conductive surface that is compatible with a composite resin system can enhance the surface conductivity of composites, improving its lightning strike mitigation capabilities.
Preparation and characterization of corn starch/soy protein biocomposite film reinforced with graphene and graphene oxide nanoplatelets
Authors: Mansoori Elham , Behzad Tayebeh , Shafieizadegan‐Esfahani Ahmad Reza
Published: May 2019

Corn starch (CS) and soy protein isolate (SPI), as inexpensive, abundant, and biodegradable materials, can chemically interact well with each other to produce biofilms. However, to overcome some of their physical and mechanical limitations, it is preferred to use their composite form, employing reinforcing materials. In this study, initially, graphene (G) and graphene oxide (GO) were synthesized by a green method. Then, to enhance the polymer blend final properties, the effects of adding G and GO in the range of 0.5 to 2 wt% on physical and mechanical properties of starch/protein blend were investigated. The results showed that the presence of 0.5‐wt% G and 2‐wt% GO significantly increased the modulus of starch/protein film from 252 to 578 and 449 MPa, respectively. In addition, the thermal stability of CS/SPI/GO (2 wt%) composite film was 50°C to 60°C more than that of the pure starch/protein film. On the other hand, G‐reinforced composite films tended to decline water diffusion compared with the pure polymer film. In addition, the composite film with 2‐wt% GO content had the lowest oxygen permeation rate (3.48 cm3 μm/m2d kpa) among the other composite films.
Hierarchical structure microspheres of PCL block copolymers via electrospraying as coatings for fabric with mechanical durability and self‐cleaning ability
Authors: Li Wulong , Wang Haipeng , Li Zhanxiong
Published: May 2019

The various morphology and structure microspheres were fabricated via one‐step single‐solvent electrospraying of hydrophilic and hydrophobic block modified copolymer of polycaprolactone (PCL). A honeycomb‐like hierarchical structure microspheres of PCL‐b‐PTFOA(4h) and abundant nanometer pores of PCL‐b‐PEG400 microspheres were obtained due to the solvent evaporation, thermally and polymer diffusion‐induced phase separation effect. Furthermore, a superhydrophobic coatings and robust superhydrophobic‐coated cotton woven fabric surfaces were prepared by using PCL‐b‐PTFOA(4h) microspheres with hierarchical structure and low surface energy. The contact angle (CA) and sliding angle (SA) of PCL‐b‐PTFOA(4h) microspheres‐coated cotton woven fabric surfaces reached 164.4 ± 5.5° and 6.8 ± 0.5°, respectively, which allows for self‐cleaning. The self‐cleaning test demonstrated that the coated superhydrophobic surface could shed aqueous dyes and dust without any trace. The superhydrophobic‐coated fabric shows good soaping fastness against mechanical abrasion without significant reduction of CA. This electrospraying coating of block copolymers can provide a simple, facile, and promising technique for producing multifunctional textiles.
Lineage tracing suggests that ovarian endosalpingiosis does not result from escape of oviductal epithelium
Authors: Wang Yisheng , Sessine Michael S , Zhai Yali , Tipton Courtney , McCool Kevin , Kuick Rork , Connolly Denise C , Fearon Eric R , Cho Kathleen R
Published: May 2019

Most high‐grade serous carcinomas are thought to arise from Fallopian tube epithelium (FTE), but some likely arise outside of the tube, perhaps from ectopic tubal‐type epithelium known as endosalpingiosis. Importantly, the origin of endosalpingiosis is poorly understood. The proximity of the tubal fimbriae to the ovaries has led to the proposal that disruptions in the ovarian surface that occur during ovulation may allow detached FTE to implant in the ovary and form tubal‐type glands and cysts. An alternative model suggests that cells present in ectopic locations outside the Müllerian tract retain the capacity for multi‐lineage differentiation and can form glands with tubal‐type epithelium. We used double transgenic Ovgp1‐iCreERT2;R26RLSL‐eYFP mice, which express an eYFP reporter protein in OVGP1‐positive tissues following transient tamoxifen (TAM) treatment, to track the fate of oviductal epithelial cells. Cohorts of adult mice were given TAM to activate eYFP expression in oviductal epithelium, and ovaries were examined at time points ranging from 2 days to 12 months post‐TAM. To test whether superovulation might increase acquisition of endosalpingiosis, additional cohorts of TAM‐treated mice underwent up to five cycles of superovulation and ovaries were examined at 1, 6, and 12 months post‐TAM. Ovaries were sectioned in their entirety to identify endosalpingiosis. Immunohistochemical staining for PAX8, tubulin, OVGP1, and eYFP was employed to study endosalpingiosis lesions. Ovarian endosalpingiosis was identified in 14.2% of TAM‐treated adult mice. The endosalpingiotic inclusion glands and cysts were lined by secretory and ciliated cells and expressed PAX8, tubulin, OVGP1, and eYFP. Neither age nor superovulation was associated with a significant increase in endosalpingiosis. Endosalpingiosis was also occasionally present in the ovaries of pre‐pubertal mice. The findings imply that ovarian endosalpingiosis in the mouse does not likely arise as a consequence of detachment and implantation of tubal epithelium and other mechanisms may be relevant. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Mucormycosis diagnosed during induction chemotherapy in five pediatric patients with acute lymphoblastic leukemia
Authors: Aftandilian Catherine , Eguiguren Lourdes , Mathew Roshni , Messner Anna
Published: May 2019

Mucormycosis in pediatric oncology patients is a rare invasive fungal infection associated with significant morbidity and mortality. We describe five patients diagnosed with mucormycosis during induction chemotherapy for acute lymphoblastic leukemia at our institution. All of the patients in our series survived, some in spite of having disseminated disease. Most of the patients’ chemotherapy was modified with the aim of controlling their leukemia while minimizing immunosuppression until their fungal infection was under control. Although mucormycosis is frequently fatal, rapid diagnosis and a multidisciplinary approach can lead to excellent outcomes, even in patients undergoing intensive chemotherapy.
Safety profile of traditional Chinese herbal injection: An analysis of a spontaneous reporting system in China
Authors: Li Haona , Deng Jianxiong , Deng Lewen , Ren Xuequn , Xia Jielai
Published: May 2019

Purpose

Although a series of serious adverse events have continually raised concerns about the potential toxicity of traditional Chinese medicine injections (TCM injections), studies on this subject are still sparse. We conducted a descriptive analysis of a spontaneous reporting system in China to describe the safety profile of TCM injections.

Methods

The safety profile of TCM injections is described by descriptive analysis of 559 066 adverse reports collected from Guangdong Provincial Center for adverse drug reaction (ADR) Monitoring in China during 2003 to 2017.

Results

The percentage of new or serious ADRs of TCM injections is much higher than average percentage of China's spontaneous reporting system (SRS) as a whole (48.70% vs <25%). Compared with conventional injections, TCM injections have a slightly lower percentage of serious ADRs (6.02% vs 6.72%) and much higher percentage of unknown (new) ADRs (46.74% vs 24.13%). The gender and age distribution for TCM injections are similar to conventional injections. The reporting rates of ADRs increased with age. Anaphylactic shock and anaphylactoid reaction are high‐risk ADRs for TCM injections and, anaphylactic shock is ranked number 1 in causing deaths (50.00%).

Conclusions

There are some differences and similarities on the safety profile between TCM injections and conventional injections. TCM injections have higher risk of adverse effects than any other dosage forms of TCM medications and higher percentage of new or serious adverse effects than conventional injections. A lot of work need to be done to clarify the huge amount of potential unknown adverse effects related to TCM injections.
Morphology and ionic conductivity relationship in silk/cellulose biocomposites
Authors: Blessing Bailey , Trout Cory , Morales Abneris , Rybacki Karleena , Love Stacy A , Lamoureux Guillaume , O'Malley Sean M , Hu Xiao , Salas‐de la Cruz David
Published: May 2019

The relationship between morphology and the ionic conductivity of polysaccharide–protein bio‐electrolyte membranes is explored in this study. Structural proteins and polysaccharides form hydrophobic and electrostatic interactions, and the resulting matrices can exhibit novel and useful properties. However, transforming these natural biomacromolecules from their native state to a more usable form is challenging. The structural, morphological, thermal, mechanical and electrical properties of biomaterials composed of microcrystalline cellulose and Bombyx mori silk when regenerated together using ionic liquids and various coagulation agents were investigated using a diverse set of techniques including Fourier transform infrared spectroscopy, SEM, TGA, DSC, X‐ray scattering, AFM‐based nanoindentation and dielectric relaxation spectroscopy. The surface topography of the films reveals morphological changes with varying coagulation agents and ionic liquids. It was found that the thermal and mechanical properties were dependent on intermolecular interactions dictated by the type of ionic liquid used during the coagulation process. X‐ray scattering provided information on how the cellulose crystallinity varied with coagulation agent. Specifically, samples coagulated with hydrogen peroxide showed an increase in cellulose crystallinity impacting properties such as elasticity, hardness and ionic conductivity of the biocomposites. In addition, the results revealed a strong correlation between β‐sheet content and ionic conductivity and cellulose crystallinity. The results provided evidence that the ionic conductivity is dependent on protein β‐sheet content and cellulose crystallinity. © 2019 Society of Chemical Industry
Electronic structure of GaP/Si(001) heterojunctions and the role of hydrogen passivation
Authors: Meidanshahi Reza Vatan , Zhang Chaomin , Zou Yongjie , Honsberg Christiana , Goodnick Stephen M.
Published: May 2019

Epitaxially grown single crystal GaP on Si is of considerable interest due to being nearly lattice matched to Si, making it attractive for III‐V/Si solar cells. GaP has been used as a buffer layer for III‐V/Si solar cells and also in selective contact Si solar cells. The performance and functionality of such devices are strongly influenced by the presence of localized states at the GaP/Si interface. Here, we examine the electronic structure of GaP/Si(001) heterojunctions and the effect of hydrogen (H) passivation at the interface, in contrast to interface mixing, through density functional theory calculations. Our calculations show that due to the heterovalent mismatch nature of the GaP/Si interface, there is a high density of localized states at the abrupt GaP/Si interface due to the excess charge associated with heterovalent bonding, as reported elsewhere. We find that the addition of H leads to additional bonding at the interface, which mitigates the charge imbalance, and greatly reduces the density of localized states, leading to a nearly ideal heterojunction. A similar result is found with a completely intermixed interface (alternating cation and anion bonding) in terms of low interface state density. However, when the intermixing occurs through single‐layer or double‐layer terraces, the benefits of intermixing are lost and the interface state density reverts more to the abrupt interface case.
Toward Axonal System Biology: Genome Wide Views of Local mRNA Translation
Authors: Farias Joaquina , Sotelo José Roberto , Sotelo‐Silveira José
Published: May 2019

Neurons present a highly polarized morphology, often displaying a significantly imbalanced distribution of the cytoplasm between the somatic and axonal domains. This imbalance requires cell‐specific mechanisms for the maintenance of the axoplasmic mass during development, neuronal homeostasis, and recovery after injury. Although it has been clearly demonstrated that axoplasmic transport contributes a large amount of proteins to the axons, local protein synthesis has been fully accepted as an important complementary source of proteins, which aids in the maintenance of the axoplasmic mass in both normal and regenerating conditions. This review analyzes and highlights the most important advances in the knowledge of the axonal transcriptome, translatome, and proteome at a genome‐wide scale. It is discussed how this knowledge has provided researchers with new insights regarding the involvement of local protein synthesis in many key neuronal functions. In addition, challenges, open questions, and methods currently available to study axonal mRNA localization and protein synthesis are addressed.
Geometric Quantum Computation with Shortcuts to Adiabaticity
Authors: Du Yanxiong , Liang Zhentao , Yan Hui , Zhu Shiliang
Published: May 2019

Realization of a large‐scale quantum computation relies on fast and high‐fidelity quantum control. Geometric quantum control is thought to be a promising candidate for quantum computation which consolidates the robustness against both random noise (through the global geometrical feature) and systematic errors (through adiabatic characteristic). The adiabatic process of geometric control can be accelerated through an auxiliary Hamiltonian in different scenarios by means of shortcuts to adiabaticity (STA). Especially, the auxiliary Hamiltonian can be absorbed into the original interacting configuration in most of the cases, which allows STA to coalesce with the Abelian or the non‐Abelian geometric control. As a consequence, geometric quantum control can have an enhanced robustness against decoherence after speeding up by STA. Here, the recent theoretical and experimental advances in geometric quantum computation based on STA are reviewed.
Modestly weighted logrank tests
Authors: Magirr Dominic , Burman Carl‐Fredrik
Published: May 2019

We propose a new class of weighted logrank tests (WLRTs) that control the risk of concluding that a new drug is more efficacious than standard of care, when, in fact, it is uniformly inferior. Perhaps surprisingly, this risk is not controlled for WLRT in general. Tests from this new class can be constructed to have high power under a delayed‐onset treatment effect scenario, as well as being almost as efficient as the standard logrank test under proportional hazards.
Preparation of a Poly(ethylene glycol)‐Based Cross‐Linked Network from a Click Reaction for Enzyme Immobilization
Authors: Oktay Burcu , Demir Serap , Kayaman‐Apohan Nilhan
Published: May 2019

In this study, a polyethylene glycol (PEG)‐maleimide film was prepared by a thiol‐ene click reaction. The covalent immobilization of amylase was carried out onto the PEG‐maleimide based photo‐curable network via epoxy and C=O groups without any linker. The epoxy and carbonyl groups on the PEG backbone improved the affinity of the enzyme. The immobilization yield of amylase onto the film was 72.46%. The immobilization capacity was also determined as 313 mg/g. The thermal stability of amylase improved via covalent attachment. Immobilized amylase showed maximum activity at 40 °C and pH 6.5. The immobilized amylase continued to retain 66% of its initial activity after 30 days.
Thermochemical Conversion of Guaiacol in Aqueous Phase by Density Functional Theory
Authors: Agrawal Kushagra , Verma Anand M. , Kishore Nanda
Published: May 2019

The conversion of guaiacol to benzene, toluene and o‐cresol along with several important intermediates like phenol, catechol and others in aqueous phase has been theoretically studied under the framework of density functional theory (DFT). The bond dissociation energy (BDE) calculation has been performed on optimized structures of guaiacol, phenol and anisole; and accordingly several reaction pathways have been proposed. The thermochemical parameters like Gibb's free energy change and enthalpy change of the reactions have also been reported using M06‐2X functional. In BDE study of the three compounds, i. e., guaiacol, phenol and anisole, it is observed that the scission of H. at fifth carbon position of an aromatic ring is the highest energy demanding dissociation, whereas the cleavage of bond from the functional group attached to the aromatic ring has the least BDE. The formation of phenol from guaiacol is more likely to occur by simultaneous hydrogenation and demethoxylation of guaiacol amongst all proposed pathways in aqueous phase. Further, decomposition of phenol to benzene is likely to occur via direct dehydroxylation of phenol. The simultaneous hydrogenation and dehydroxylation of guaiacol in aqueous phase are most likely to produce anisole which can further be reduced to phenol by direct cleavage of methyl group followed by hydrogenation. Further, free energy change landscape shows the conversion of guaiacol to phenol to be kinetically most favourable conversion at low temperature and high pressure in the aqueous phase. Finally, the increase in temperature causes a decrease in Gibb's free energy change and enthalpy change of overall reactions, thereby increasing favourability of most of the reactions in aqueous phase. Furthermore, the comparison between gaseous and aqueous phase results have been made wherever applicable.
Graphene/Carbon Black Co‐modified Separator as Polysulfides Trapper for Li‐S Batteries
Authors: Zhang Kangming , Dai Liqin , Xie Lijing , Kong Qingqiang , Su Fangyuan , Liu Zhuo , Shi Jing , Liu Yanzhen , Chen Zhiwen , Chen Chengmeng
Published: May 2019

Lithium‐sulfur batteries are widely concerned because of their high energy density. However, its application is limited by the shuttle effect of polysulfides. In this work, the reduced graphene oxide/carbon black co‐modified separator is fabricated using the vacuum filtration method. The initial discharge specific capacity of lithium‐sulfur battery with reduced graphene oxide/carbon black (1:1) separator reaches 1014.5 mAh g−1 at 0.2 C and the capacity decay rate is only 0.17% per cycle, which shows excellent cycling stability. Furthermore, the capacity retention ratio is 75.47% at 1 C after 500 cycles. Particularly, it shows outstanding performance at high current density, and the specific capacity keeps at 612.2 mAh g−1 even at 5 C. The excellent electrochemical performance can be attributed to the physical adsorption of abundant pores and the chemical adsorption of hydroxyl functional group, providing strong capability for trap polysulfides. The co‐modified separator not only serves as trapper to inhibit the shuttle effect of polysulfides, but also acts as upper current collector for the reuse of captured polysulfides. This simple and controllable preparation method can be applied in the design of long‐cycle life and high power density of lithium‐sulfur batteries.
Hydrogenolysis of Biomass‐Derived 5‐Hydroxymethylfurfural to Produce 2,5‐Dimethylfuran Over Ru‐ZrO2‐MCM‐41 Catalyst
Authors: Raut Amol B. , Nanda Binita , Parida Kulamani M. , Bhanage Bhalchandra M.
Published: May 2019

In this work, an effective catalytic route for the selective hydrogenolysis of renewable biomass‐derived 5‐hydroxymethylfurfural (HMF) to high quality bio‐fuel 2,5‐dimethylfuran (DMF) was reported using Ru supported on ZrO2‐MCM‐41. The synthesized Ru supported on ZrO2‐MCM‐41 catalyst was characterized by different techniques such as XRD, BET surface area, XPS, SEM, TEM, EDX, TGA and TPD. Reaction parameters, like time, metal loading on ZrO2‐MCM‐41, catalyst loading, temperature, H2 pressure and solvent, were optimized for the conversion of HMF to DMF using prepared catalyst. The investigation performed in this study shows that Ru supported on ZrO2‐MCM‐41 is highly active and selective catalyst for effective transformation of the HMF into DMF in high yield and selectivity. With the use of 2 wt % Ru‐ZrO2‐MCM‐41 catalyst, 90% yield of DMF was obtained from HMF with very short reaction time of 1 h. The catalyst was recycled upto six time with slight decrease in yield after 4th cycle. A direct conversion of Fructose to DMF was also achieved in 53% yield using Amberlyst‐15 and 2%Ru‐ZrO2‐MCM‐41 combined catalyst in n‐butanol.
High Photocatalytic Performance of Pd/PdO‐Supported BiVO4 Nanoparticles for Rhodamine B Degradation under Visible LED Light Irradiation
Authors: Nguyen Trinh Duy , Cao Vu Dai , Nong Linh Xuan , Nguyen Vinh Huu , Bach Long Giang , Le Nhan Thi Hong , Luu Tuan Duy , Hong Seong Soo , Lim Kwon Taek , Vo Dai‐Viet N.
Published: May 2019

Pd/PdO‐decorated BiVO4 nanoparticles were prepared by two‐step router: (i) monoclinic scheelite BiVO4 nanoparticles were fabricated via the co‐precipitation process in the presence of urea; (ii) Pd/PdO was decorated BiVO4 surface by the combination of by precipitation method and annealing process. The as‐synthesized catalysts were characterized by X‐ray powder diffraction (XRD) analysis, Raman spectra, X‐ray photoelectron (XPS) spectra, UV‐visible diffuse reflectance (UV‐vis DRS) spectra, and photoluminescence (PL) spectroscopy. The photocatalytic performance of Pd/PdO‐decorated BiVO4 samples exhibited excellent photodegradation of rhodamine B as well as the OH• radical generation under LED light irradiation as a comparison with the bare BiVO4. This excellent outcome is due to the reduced electron/hole recombination of Pd/PdO‐decorated BiVO4 samples, which was confirmed by PL characterization. Therefore, the fabrication of semiconductors with a combination of noble metal/oxides are good candidates for enhancement of their photocatalytic performance.
M13 Virus‐Based Framework for High Fluorescence Enhancement
Authors: Huang Shengnan , Qi Jifa , deQuilettes Dane W. , Huang Mantao , Lin Ching‐Wei , Bardhan Neelkanth M. , Dang Xiangnan , Bulović Vladimir , Belcher Angela M.
Published: May 2019

Fluorescence imaging is a powerful tool for studying biologically relevant macromolecules, but its applicability is often limited by the fluorescent probe, which must demonstrate both high site‐specificity and emission efficiency. In this regard, M13 virus, a versatile biological scaffold, has previously been used to both assemble fluorophores on its viral capsid with molecular precision and to also target a variety of cells. Although M13‐fluorophore systems are highly selective, these complexes typically suffer from poor molecular detection limits due to low absorption cross‐sections and moderate quantum yields. To overcome these challenges, a coassembly of the M13 virus, cyanine 3 dye, and silver nanoparticles is developed to create a fluorescent tag capable of binding with molecular precision with high emissivity. Enhanced emission of cyanine 3 of up to 24‐fold is achieved by varying nanoparticle size and particle‐fluorophore separation. In addition, it is found that the fluorescence enhancement increases with increasing dye surface density on the viral capsid. Finally, this highly fluorescent probe is applied for in vitro staining of E. coli. These results demonstrate an inexpensive framework for achieving tuned fluorescence enhancements. The methodology developed in this work is potentially amendable to fluorescent detection of a wide range of M13/cell combinations.
Weight discordance and perinatal mortality in monoamniotic twin pregnancy: analysis of MONOMONO, NorSTAMP and STORK multiple‐pregnancy cohorts
Authors: Saccone G. , Khalil A. , Thilaganathan B. , Glinianaia S. V. , Berghella V. , D'Antonio F. ,   for the MONOMONO, NorSTAMP and STORK research collaboratives
Published: May 2019

Objectives

The primary objective was to quantify the risk of perinatal mortality in non‐anomalous monochorionic monoamniotic (MCMA) twin pregnancies complicated by birth‐weight (BW) discordance. The secondary objectives were to investigate the effect of inpatient vs outpatient fetal monitoring on the risk of mortality in weight‐discordant MCMA twin pregnancies, and to explore the predictive accuracy of BW discordance for perinatal mortality.

Methods

This analysis included data on 242 MCMA twin pregnancies (484 fetuses) from three major research collaboratives on twin pregnancy (MONOMONO, STORK and NorSTAMP). The primary outcomes were the risks of intrauterine (IUD), neonatal (NND) and perinatal (PND) death, according to weight discordance at birth from ≥ 10% to ≥ 30%. The secondary outcomes were the association of inpatient vs outpatient fetal monitoring with the risk of mortality in weight‐discordant pregnancies, and the accuracy of BW discordance in predicting mortality. Logistic regression and receiver‐operating‐characteristics‐curve analyses were used to analyze the data.

Results

The risk of IUD was significantly increased in MCMA twin pregnancies with BW discordance ≥ 10% (odds ratio (OR), 2.2; 95% CI, 1.1–4.4; P = 0.022) and increased up to an OR of 4.4 (95% CI, 1.3–14.4; P = 0.001) in those with BW discordance ≥ 30%. This association remained significant on multivariate logistic regression analysis for BW‐discordance cut‐offs ≥ 20%. However, weight discordance had low predictive accuracy for mortality, with areas under the receiver‐operating‐characteristics curve of 0.60 (95% CI, 0.46–0.73), 0.52 (95% CI, 0.33–0.72) and 0.57 (95% CI, 0.45–0.68) for IUD, NND and PND, respectively. There was no difference in the risk of overall IUD, single IUD, double IUD, NND or PND between pregnancies managed as an inpatient compared with those managed as an outpatient, for any BW‐discordance cut‐off.

Conclusions

MCMA twin pregnancies with BW discordance are at increased risk of fetal death, signaling a need for increased levels of monitoring. Despite this, the predictive accuracy for mortality is low; thus, detection of BW discordance alone should not trigger intervention, such as iatrogenic delivery. The current data do not demonstrate an advantage of inpatient over outpatient management in these cases. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Single umbilical artery and risk of congenital malformation: population‐based study in Norway
Authors: Ebbing C. , Kessler J. , Moster D. , Rasmussen S.
Published: May 2019

Objectives

Single umbilical artery (SUA) is associated with congenital malformations in most organ systems, but reported findings have not been consistent. While it has been suggested that genetic and persisting environmental factors influence the development of SUA, it is not known whether there is an increased risk of recurrence in a subsequent pregnancy of the same woman. The aims of this study were to investigate the occurrence of, and risk factors for, SUA in Norway, to assess its association with congenital malformations and trisomies 13, 18 and 21 and to study the risk of recurrence of SUA in subsequent pregnancies.

Methods

This was a population‐based study of all (n = 918 933) singleton pregnancies of > 16 weeks' gestation recorded in the Medical Birth Registry of Norway from 1999 to 2014. To identify risk factors and congenital malformations associated with SUA, generalized estimating equations and logistic regression were used to calculate odds ratios (OR) with 95% CIs. ORs were also calculated for the recurrence of SUA in subsequent pregnancy.

Results

The occurrence of SUA in our population was 0.46% (4241/918 933). Parity ≥ 4, smoking, maternal pregestational diabetes, epilepsy, chronic hypertension, previous Cesarean delivery and conception by assisted reproductive technology increased the odds of having SUA. There was a particularly strong association between SUA and gastrointestinal atresia or stenosis in the neonate, with ORs of 25.8 (95% CI, 17.0–39.1) and 20.3 (95% CI, 13.4–30.9) for esophageal and anorectal atresia or stenosis, respectively, followed by an OR of 5.9 (95% CI, 1.9–18.5) for renal agenesis. SUA was associated with an up to 7–8 times increased risk of congenital heart defects. There was an association with microcephaly, congenital hydrocephalus and other congenital malformations of the brain and spinal cord. Diaphragmatic hernia, limb reductions and cleft lip or palate had a weaker association with SUA, with ORs ranging from 4.8 to 2.8. The associations with trisomy 18 and 13 were equally strong (OR 14.4 (95% CI, 9.3–22.4) and OR 13.6 (95% CI, 6.7–27.8), respectively), and the risk of trisomy 21 was doubled (OR 2.1 (95% CI, 1.2–3.6)). Pregnancies with SUA, with or without an associated malformation, had a 2‐fold increased risk for SUA in a subsequent pregnancy.

Conclusions

SUA is associated strongly with gastrointestinal atresia or stenosis, suggesting common developmental mechanisms. The increased risk of recurrence of SUA suggests that genetic and/or persisting environmental factors influence the risk. We found that SUA had equally strong associations with trisomies 13 and 18. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.
Bio‐processing aids based on jatropha seed oil and its epoxidized derivatives in carbon black‐reinforced natural rubber
Authors: Intharapat Punyanich , Kongnoo Aroon , Maiwat Preeyapon
Published: May 2019

Jatropha seed oil (JSO) is renewable oil with unique characteristics including a high flash point, low viscosity and saponification value, and a solubility parameter close to that of natural rubber. The incorporation of JSO and its epoxidized derivatives containing 50% (EJSO‐50) and 100% mole epoxide groups (EJSO‐100) in carbon black‐filled natural rubber was compared with the incorporation of paraffinic, naphthenic, and treated distillate aromatic extract oils in a range of 2–10 phr. The results showed that JSO promoted good rubber processability similar to that achieved with paraffinic and naphthenic oils, with the advantages of the shortest cure time and scorch time. However, it was found that the epoxide groups especially in EJSO‐100 can interfere in the vulcanization reaction resulting in poorer cure behaviors and mechanical properties. The abrasion resistance of the rubber containing JSO was the highest and progressively improved in a range of 4–8 phr. Moreover, using the various oils at this range of values can improve filler dispersion, sustain the tensile properties, and achieve a balance between wet grip and rolling resistance. J. VINYL ADDIT. TECHNOL., 26:62–76, 2020. © 2019 Society of Plastics Engineers
Enhanced estimation of boundary layer advective properties to improve space‐to‐time conversion processes for wind energy applications
Authors: Duncan James B. , Hirth Brian D. , Schroeder John L.
Published: May 2019

Remote sensing instruments that scan have the ability to provide high‐resolution spatial measurements of atmospheric boundary layer winds across a region. However, the ability to use these spatially distributed measurements to extract temporal variations in the flow at time scales less than the measurement revisit period is historically limited. As part of this work, the framework for an enhanced space‐to‐time conversion technique is established, allowing for time histories of atmospheric boundary layer wind characteristics to be reliably extracted for locations within the measurement domain. This space‐to‐time conversion technique is made possible by quantifying momentum advection within the measurement domain, rather than simply assuming a uniform advection based on a singular mean wind speed and direction. The use of this technique enables the extraction of long lead‐time (ie, upwards of 60 seconds) forecasts of wind speed and direction at individual locations within the measurement domain, thereby expanding the application and potential benefits of scanning instruments. For example, these long lead‐time forecasts can be used to enhance proactive wind turbine control and more accurately define wind turbine wake statistics.
Nonsense‐mediated mRNA decay: The challenge of telling right from wrong in a complex transcriptome
Authors: Kishor Aparna , Fritz Sarah E. , Hogg J. Robert
Published: May 2019

The nonsense‐mediated mRNA decay pathway selects and degrades its targets using a dense network of RNA‐protein and protein–protein interactions. Together, these interactions allow the pathway to collect copious information about the translating mRNA, including translation termination status, splice junction positions, mRNP composition, and 3′UTR length and structure. The core NMD machinery, centered on the RNA helicase UPF1, integrates this information to determine the efficiency of decay. A picture of NMD is emerging in which many factors contribute to the dynamics of decay complex assembly and disassembly, thereby influencing the probability of decay. The ability of the NMD pathway to recognize mRNP features of diverse potential substrates allows it to simultaneously perform quality control and regulatory functions. In vertebrates, increased transcriptome complexity requires balance between these two functions since high NMD efficiency is desirable for maintenance of quality control fidelity but may impair expression of normal mRNAs. NMD has adapted to this challenge by employing mechanisms to enhance identification of certain potential substrates, while using sequence‐specific RNA‐binding proteins to shield others from detection. These elaborations on the conserved NMD mechanism permit more sensitive post‐transcriptional gene regulation but can have severe deleterious consequences, including the failure to degrade pathogenic aberrant mRNAs in many B cell lymphomas.

This article is categorized under:

RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution

RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications

RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms
Adolescent stress reactivity: Examining physiological, psychological and peer relationship measures with a group stress protocol in a school setting
Authors: Katz Deirdre A. , Peckins Melissa K. , Lyon Celena C.
Published: May 2019

Introduction

Adolescents experience enhanced social sensitivity and biopsychosocial changes that can be challenging. Much remains unknown about the effect of psychological characteristics and peer relationships on adolescents’ physiological responses to stress, due in part to methodological limitations.

Methods

To test how adolescents’ peer relationships and psychological characteristics are associated with their physiological and psychological response to stress, we administered the Group Public Speaking Task for Adolescents (GPST‐A) to 54 adolescents (n = 40 girls; Mage = 16.6 years) in two high schools in the United States. Salivary cortisol and alpha‐amylase (sAA), and positive and negative affect were measured six times. Relationships among group members were measured, resulting in whole‐network data. State and trait rumination, five factors of coping, and emotional reappraisal and suppression were measured along with symptoms of depression and anxiety.

Results

Greater levels of negative evaluation and victimization among group members were associated with a steeper increase and decline in the negative affect response, yet not associated with the physiological response to stress. Greater positive affect was associated with decreased cortisol reactivity, whereas negative affect was associated with steeper cortisol and sAA reactivity. Rumination, disengagement coping, and depression symptoms were related to the physiological response to stress.

Conclusions

The GPST‐A is feasible to administer in a school context with adolescents to collect both physiological and psychological stress responses. Findings from the present study suggest peer relationships are important for understanding adolescents' psychological response to stressors while psychological characteristics are important for adolescents’ physiological response to stress.
Axially asymmetric traveling fronts in balanced bistable reaction-diffusion equations
Authors: Taniguchi Masaharu
Published: May 2019

For a balanced bistable reaction-diffusion equation, an axisymmetric traveling front has been well known. This paper proves that an axially asymmetric traveling front with any positive speed does exist in a balanced bistable reaction-diffusion equation. Our method is as follows. We use a pyramidal traveling front for an unbalanced reaction-diffusion equation whose cross section has a major axis and a minor axis. Preserving the ratio of the major axis and a minor axis to be a constant and taking the balanced limit, we obtain a traveling front in a balanced bistable reaction-diffusion equation. This traveling front is monotone decreasing with respect to the traveling axis, and its cross section is a compact set with a major axis and a minor axis when the constant ratio is not 1.
Endoscopic stent in malignant colonic obstruction: the risk of tumor seeding
Authors: Leite Marta Ludovina Loureiro Fernandes , Barbosa Laura Elisabete Ribeiro
Published: May 2019

Introduction Malignant colonic occlusion is traditionally considered a surgical emergency. With the development of endoscopic techniques, metallic stents have emerged to ensure the colonic patency in nonsurgical candidates and, more recently, as a temporary measure until elective resection surgery is possible.

Materials and methods The research was conducted in PubMed and collected a total of 46 articles, including cross-references.

Results Ideally, intestinal occlusion should be resolved through tumor's primary resection with direct anastomosis. To avoid dehiscence of the anastomosis, tumor's resection may be performed with Hartmann's procedure. Metal stents are an alternative to emergency surgery and show excellent results in reliving colonic obstruction. However, they may have serious complications related to colonic perforation, migration and tumor dissemination.

Discussion and conclusion Observational studies and clinical trials show discrepant results. Metal stents are increasingly accepted in palliative care but are not yet recommended as a bridge to curative surgery. Treatment should be individualized, according to surgical risk and the probability of endoscopic complications.
Pregnancy and Sexual Relationships Study Involving wOmen and meN (PASSION Study)
Authors: Dwarica Denicia S. , Collins Gretchen G. , Fitzgerald Colleen M. , Joyce Cara , Brincat Cynthia , Lynn Mary
Published: May 2019

Introduction

Sexual satisfaction is believed to decrease during pregnancy; however, the effect of pregnancy on the sexual relationship in a couple is not well studied.

Aim

To assess for sexual dysfunction in heterosexual couples during pregnancy.

Methods

We performed a cross-sectional study of heterosexual pregnant women in the third trimester and their cohabitating partners.

Main Outcome Measures

Sexual satisfaction in heterosexual couples during pregnancy was assessed with a self-reported questionnaire, the Golombok-Rust Inventory of Sexual Satisfaction (GRISS) questionnaire.

Results

A total of 53 couples met eligibility criteria, and nearly all of those approached participated (52 of 53 couples). All couples were enrolled at or after 35 weeks’ gestation. The mean age was 29.0 ± 6.4 and 31.3 ± 6.9 years for women and men, respectively. 60% of couples were married, and the remainder were cohabitating and in a committed relationship. When analyzing the results of the GRISS questionnaire for both partners, a significant difference was seen in mean avoidance of sex between women and men (3.31 vs 2.63; P = .047) and non-sensuality (3.54 vs 2.75; P = .040). Women reported more of a decrease in communication about sex when compared with their partners (3.79 vs 3.23; P = .047). Vaginismus was more problematic during pregnancy than before (mean = 4.17), and frequency of intercourse was decreased (mean = 4.93) based on calculated GRISS scores.

Clinical Implications

Pregnant couples reported decreased frequency of intercourse and more pain with intercourse in women. Women were more likely to avoid intercourse and reported more problems with communication regarding sexual needs.

Strength & Limitations

This study is the first to assess both partners in pregnancy. Due to the nature of the study, we were unable to assess other factors affecting the relationship that may result in sexual dysfunction, there was no control group, and the results are limited to heterosexual couples.

Conclusion

Overall sexual satisfaction and function were not problematic for these couples during pregnancy based on the GRISS scale.
Public Archaeology's Mammoth in the Room: Engaging Wikipedia as a Tool for Teaching and Outreach
Authors: Grillo Katherine M. , Contreras Daniel A.
Published: May 2019

Although archaeology has become increasingly concerned with engaging diverse publics, and has embraced the internet as a means of facilitating such engagement, attitudes towards Wikipedia have—understandably—been more ambivalent. Nevertheless, we argue here, Wikipedia's popularity and reach mean that archaeologists should actively engage with the website by adding and improving archaeological content. One way to do this is in the classroom: this paper provides a detailed how-to for instructors interested in having students create new Wikipedia content. We provide a case study in Wikipedia engagement from an advanced undergraduate course on African Archaeology, assess a program (Wiki Education) designed to help, and suggest further avenues for future outreach. We conclude that Wikipedia's utopian mission aligns with many of the goals of public archaeology, and argue that archaeology has much to gain by engaging with—rather than ignoring or even shunning—Wikipedia.
Spatio-temporal variations in seasonal ice tongue submarine melt rate at a tidewater glacier in southwest Greenland
Authors: MOYER A. N. , NIENOW P. W. , GOURMELEN N. , SOLE A. J. , SLATER D. A. , TRUFFER M. , FAHNESTOCK M.
Published: May 2019

Submarine melting of tidewater glaciers is proposed as a trigger for their recent thinning, acceleration and retreat. We estimate spring submarine melt rates (SMRs) of Kangiata Nunaata Sermia in southwest Greenland, from 2012 to 2014, by examining changes in along-fjord freeboard and velocity of the seasonal floating ice tongue. Estimated SMRs vary spatially and temporally near the grounding line, with mean rates of 1.3 ± 0.6, 0.8 ± 0.3 and 1.0 ± 0.4 m d−1across the tongue in 2012, 2013 and 2014, respectively. Higher melt rates correspond with locations of emerging subglacial plumes and terminus calving activity observed during the melt season using time-lapse camera imagery. Modelling of subglacial flow paths suggests a dynamic system capable of rapid re-routing of subglacial discharge both within and between melt seasons. Our results provide an empirically-derived link between the presence of subglacial discharge plumes and areas of high spring submarine melting and calving along glacier termini.
Radiocarbon Evidence for Initial Early Formative Period Occupation in Coastal Oaxaca, Mexico
Authors: Hepp Guy David
Published: May 2019

Seven AMS radiocarbon dates (1950–1525 cal BC) from controlled contexts demonstrate Early Formative period occupation in coastal Oaxaca, Mexico. These dated elements from the site of La Consentida include hearths, occupational surfaces, carbon adhering to pottery from a midden, and human bone collagen processed with XAD purification. They were excavated from primary contexts and do not represent redeposited materials. An eighth sample, dated to the Middle Formative period, is considered postoccupational. The diversity of dated deposits and features, their distribution, and their overlapping calibrated ranges indicate settlement by an initial Early Formative period village.
Maximum Altitude Sailplane Winch-Launch Trajectories
Authors: Pierson B L
Published: May 2019

A class of dynamic sailplane winch-launch trajectory problems for maximum altitude is formulated. Numerical solutions are presented for representative values of maximum allowed lift coefficient and cable acceleration. The optimal trajectory is shown to consist of a climb-dive-climb sequence. An inequality constraint on cable retraction speed is also imposed and results in more realistic trajectories.
An Alternative Treatment of Boundary Conditions for the Flow over Thick Wings
Authors: Nixon D
Published: May 2019

An alternative method of treating the boundary conditions for wing and body flow problems is developed and a detailed analysis for the flow around two-dimensional aerofoils is given. The basis of the method is the concept of an analytic continuation of the exterior flow to give a fictitious interior flow and a modified problem which can be solved using the ideas of thin-wing theory. The detailed analysis for flows described by the linear Prandtl-Glauert potential equation is given. The results obtained for several examples are satisfactory. The application of the theory to continuous and discontinuous transonic flows is outlined.
Mixing Length in the Wall Region of Turbulent Boundary Layers
Authors: Galbraith R A McD , Sjolander S , Head M R
Published: May 2019

Evidence is presented to show that the universal law of the wall has a wider range of validity than the assumptionl= ky, with k a universal constant. If an effective value of k is defined for the wall region its value is shown to vary between wide limits, and keffcan be correlated with other parameters describing the flow in the wall region.
Transition to a Rising Core at the Centre of a Vortex. Simplified Analysis for Laminar Flow
Authors: Head M R , Prahlad T S , Phillips W R C
Published: May 2019

A free-vortex flow over a stationary disc produces a boundary layer on the surface which proceeds inwards towards the centre under the action of the imposed radial pressure gradient. Close to the centre the boundary layer leaves the surface to form a rising core. The present paper uses a control-volume approach and earlier calculations of laminar boundary-layer development on the disc to determine the characteristics of the core-formation process.
An Algorithm for Autonomous Non-linear Dynamical Equations
Authors: Simpson A
Published: May 2019

The method of Beecham and Titchener is extended to systems with n degrees of freedom and is shown to be a combination of the averaging principle and the method of variation of parameters. In this extended form, the method provides a powerful solution algorithm for non-linear problems such as those which arise in aircraft structural dynamics and aeroelasticity. The method is exemplified in application to a two-degree-of-freedom damped non-linear oscillator and to a binary (flexure-aileron) non-linear flutter system. The method is finally extended to non-linear differential equations in first-order form such as those which arise commonly in flight mechanics.