bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel open‐tubular capillary electrochromatography using carboxymethyl‐β‐cyclodextrin functionalized gold nanoparticles as chiral stationary phase
Authors: Zhang Chenning , Qu Jialin , Lv Xiaoyuan , Zhang Jianbin , Fang Linlin
Published: December 2019

Enantioselective open tubular capillary electrochromatography with carboxymethyl‐β‐cyclodextrin conjugated gold nanoparticles as stationary phase was developed. This novel open tubular column was fabricated through layer‐by‐layer self‐assembly of gold nanoparticles on a 3‐mercaptopropyl‐trimethoxysilane‐modified fused‐silica capillary and subsequent surface functionalization of the gold nanoparticles through self‐assembly of 6‐mercapto‐β‐cyclodextrin. The 6‐mercapto‐β‐cyclodextrin was firstly synthesized and determined by extensive spectroscopic data. Scanning electron microscopy, energy dispersive X‐ray analysis spectroscopy, and electroosmotic flow experiments were carried out to characterize the prepared open tubular column. Then, the separation effectiveness of the open tubular column was verified by two pairs of ɑ‐tetralones derivatives enantiomers and two pairs of basic drug enantiomers (tramadol hydrochloride and zopiclone) as mode analytes. Factors that influence the enantioseparation were optimized, and under the optimized conditions, satisfactory separation results were obtained for the four enantiomers: compound A, compound B, tramadol hydrochloride, and zopiclone with resolutions of 3.79, 1.56, 1.03, 1.60, respectively. For the combination of gold nanoparticles and negatively charged carboxymethyl‐β‐cyclodextrin, the open tubular column exhibited wider separation range for neutral and basic drugs. Moreover, the repeatability and stability of the column were studied through the run‐to‐run and day‐to‐day investigations.
Recurrent laryngeal nerve regeneration using a self‐assembling peptide hydrogel
Authors: Yoshimatsu Masayoshi , Nakamura Ryosuke , Kishimoto Yo , Yurie Hirofumi , Hayashi Yasuyuki , Kaba Shinji , Ohnishi Hiroe , Yamashita Masaru , Tateya Ichiro , Omori Koichi
Published: December 2019

Objectives/Hypothesis

To regenerate defected recurrent laryngeal nerves (RLNs), various methods have been developed. However, no consistently effective treatments are currently available because of their insufficient functional recovery. RADA16‐I, a self‐assembling peptide used clinically as a hemostat, reportedly supports neurite outgrowth and functional synapse formation in vitro. The purpose of this study was to investigate the effect of RADA16‐I hydrogels on transected RLNs in rats.

Study Design

Animal experiments with controls.

Methods

Fifteen adult rats were divided into the following three groups: RADA16‐I (+), RADA16‐I (−), and neurectomy. A 6‐mm gap of the left RLN was bridged using an 8‐mm silicone tube in the RADA16‐I (−) and RADA16‐I (+) groups. Subsequently, RADA16‐I hydrogel was injected into the tube in the RADA16‐I (+) group. The surgical incisions were closed without any further treatment in the neurectomy group. After 8 weeks, laryngoscopy and electrophysiological and histological examinations were performed to evaluate the effect of RADA16‐I on nerve regeneration and thyroarytenoid muscle atrophy.

Results

Although most rats in the three groups exhibited no improvements of their vocal fold movement, partial recovery was observed in one rat in the RADA16‐I (+) group. The neurofilament‐positive areas and the number of myelinated nerves in the RADA16‐I (+) group were significantly higher than in the RADA16‐I (−) group. The area of the left thyroarytenoid muscle in the RADA16‐I (+) group was significantly larger than that of the neurectomy group.

Conclusions

Our results suggested that RADA16‐I hydrogel was effective for RLN regeneration.

Level of Evidence

NA Laryngoscope, 130:2420–2427, 2020
Paradigm shift in surgery for benign parotid tumors: 19 years of experience with almost 3000 cases
Authors: Bär Bianca , Mantsopoulos Konstantinos , Iro Heinrich
Published: December 2019

Objectives

The aim of this study was to explore the changes in philosophy in the surgical therapy of benign parotid tumors over a period of 19 years.

Methods

The records of all patients treated for benign parotid tumors between 2000 and 2018 were evaluated. Data were analyzed with respect to the number of procedures carried out per year of the study according to each of the different surgical modalities and the incidence of postoperative complications. Statistical analysis was performed using the x2 test. A P value of <.05 was considered statistically significant.

Results

A total of 2988 patients were included in this study. Our analysis showed that the increasing performance of extracapsular dissection was associated with a progressive reduction in the incidence of temporary facial nerve palsy and Frey's syndrome, while the rate of permanent facial nerve palsy remained consistently low.

Conclusion

One of the most controversial issues in head and neck surgery is which therapeutic approach is best in patients with benign parotid tumors. Our analysis demonstrated that a change of strategy towards reducing invasiveness was possible, with exceptional functional results. Avoidance of facial nerve dissection is feasible in more than two‐thirds of cases with benign tumors.

Level of Evidence

4b Laryngoscope, 130: 1941–1946, 2020
Codimension and projective dimension up to symmetry
Authors: Le Dinh Van , Nagel Uwe , Nguyen Hop D. , Römer Tim
Published: December 2019

Symmetric ideals in increasingly larger polynomial rings that form an ascending chain are investigated. We focus on the asymptotic behavior of codimensions and projective dimensions of ideals in such a chain. If the ideals are graded it is known that the codimensions grow eventually linearly. Here this result is extended to chains of arbitrary symmetric ideals. Moreover, the slope of the linear function is explicitly determined. We conjecture that the projective dimensions also grow eventually linearly. As part of the evidence we establish two non‐trivial lower linear bounds of the projective dimensions for chains of monomial ideals. As an application, this yields Cohen–Macaulayness obstructions.
Regularized Newton iteration method for a penetrable cavity with internal measurements in inverse scattering problem
Authors: Liu Lihan , Cai Jingqiu , Steve Xu Yongzhi
Published: December 2019

In this paper, we consider the inverse scattering problem of determining the shape of a cavity with a penetrable inhomogeneous medium of compact support from one source and a knowledge of measurements placed on a curve inside the cavity. First, the boundary value problem of the partial differential equations can be transformed into an equivalent system of nonlinear and ill‐posed integral equations for the unknown boundary. Then, we apply the regularized Newton iterative method to reconstruct the boundary and prove the injectivity for the linearized system. Finally, we present some numerical examples to show the feasibility of our method.
Comprehensive Analysis of the Alternaria Mycobolome Using Mass Spectrometry Based Metabolomics
Authors: Gotthardt Marina , Kanawati Basem , Schmidt Frank , Asam Stefan , Hammerl Richard , Frank Oliver , Hofmann Thomas , Schmitt‐Kopplin Philippe , Rychlik Michael
Published: December 2019

Scope

Alternaria fungi are widely distributed plant pathogens infecting grains and vegetables and causing major harvest losses in the field and during postharvest storage. Besides, consumers are endangered by the formation of toxic secondary metabolites. Some of these secondary metabolites are chemically characterized as mycotoxins, but the majority of the Alternaria mycobolome still remains unknown.

Methods and results

Fourier‐transform ion cyclotron resonance mass spectrometry (FTICR‐MS) and LC‐MS/MS are combined for the non‐targeted and targeted analysis of the metabolome of three A. alternata isolates and one A. solani isolate. Due to the ultra‐high resolution of FTICR‐MS, unique molecular formulae are assigned to measured m/z signals. The molecular formulae are matched to entries of the databases Antibase and Kyoto Encyclopedia of Genes and Genomes. The non‐targeted analysis of the fungal extracts reveals variations in the secondary metabolite profile of A. alternata and A. solani. Differences in the biosynthesis of dibenzo‐α‐pyrones, perylene quinones, tentoxin, and tenuazonic acid of the A. alternata and A. solani isolates are determined applying targeted LC‐MS/MS.

Conclusion

FTICR‐MS analyses reveal clear differences in the metabolic profile of the A. solani and the A. alternata isolates.
Miniaturized Wilkinson power divider with suppressed harmonics
Authors: Imani Mohammad Amin , Shama Farzin , Roshani Gholam Hossein
Published: December 2019

A Wilkinson power divider (WPD) with good novelty has been presented in this letter. To achieve this design, each quarter‐wavelength lines of the conventional WPD have been replaced by two symmetrical comb‐shaped resonators. These resonators create two rejection bands near their passbands, which can guarantee a good harmonics suppression for a power divider. By applying and computing the even‐/odd‐modes analysis, the suggested PD has been analyzed. In the proposed PD, the extra harmonics from second to 10th are suppressed. The normalized circuit size for operation in the center frequency of 1.1 GHz is about 0.06 × 0.07 λg. Eventually, fabrication of the power divider has been done on Rogers type RT‐Duroid 5880 substrate and tested. The measured return loss is about 16 dB in the fundamental frequency. The obtained experimental S‐parameters validated the primal design results. Therefore, the proposed WPD is a high performance one, which can be applied for applications such as the signal splitter in a Doherty power amplifier.
Complementary medicine for the management of knee and hip osteoarthritis – A patient perspective
Authors: Kim ChoWool , Stebbings Simon , Sundberg Tobias , Munk Niki , Lauche Romy , Ward Lesley
Published: December 2019

Background

Complementary medicines and therapies (CMT) are recommended in osteoarthritis (OA) treatment guidelines; however, there are few studies on CMT use in the community. The present study explored the use and perceptions of CMT for OA management in a New Zealand population.

Methods

Nineteen middle‐ to older‐aged adults with hip or knee OA, recruited from a public hospital research database, engaged in focus groups exploring CMT knowledge, factors influencing CMT use, and the role of medical professionals in the decision‐making process. Participants were organized into four groups, further to explore the impact of age or OA duration on CMT use.

Results

Thematic analysis resulted in five themes, consistent across all groups: participants' perceptions of CMT; reasons for taking CMT; reasons for not taking CMT; sources and credibility of CMT information; and medical professionals' role in CMT use. Participants indicated a range of CMT use, yet were unclear what defined a product as ‘CMT’. CMT use was influenced by symptom severity, previous experiences of themselves or trusted others, and perceived CMT effectiveness. General practitioners were identified as participants' preferred source of CMT information, owing to both their professional knowledge and lack of commercial gain from promoting CMT use.

Conclusion

Participants supported CMT for OA management, based on evidence and/or experience of effectiveness. Proactive general practitioner dialogue and subsidized CMT products recommended as part of a clinical treatment plan would encourage further CMT uptake. Additionally, the development of standardized CMT terminology would facilitate patient–doctor communication regarding CMT use and promote inter‐professional dialogue regarding multidisciplinary patient treatment.
Improve Membrane System Performance and Reduce Costs
Authors: Freeman Scott
Published: December 2019

Although a relatively new technology, membrane systems are widely used for water filtration. To save money and increase reliability, take a proactive approach to membrane system operations by understanding the basics, following recommendations, and using updated design concepts
Take a Holistic Approach to Control Nitrification
Authors: Sun Yue , Cook Nicholas
Published: December 2019

In tackling a nitrification problem at a Texas municipal water utility, results of a sampling study led to implementing a holistic strategy to improve operations, monitoring, and infrastructure.
Cd doped Ba (NO3)2 nanoparticle as broadband solar absorber in thin film organic solar cell
Authors: Kesinro Olasunkanmi R. , Boyo Adenike O. , Hamed Mohammed S. G. , Akinyemi Marvel L. , Maaza Malik , Kasinathan Kaviyarasu , Mola Genene Tessema
Published: December 2019

Enhanced photocurrent was observed by embedding Cd doped Ba (NO3)2 nanoparticle composite in the photoactive layer of bulk heterojunction organic solar cell. The research was conducted based on P3HT: PCBM blend active layer containing Cd doped Ba (NO3)2 at various concentrations. The best performance of the fabricated devices was found to be dependent on the concentration of the composite nanoparticle. A substantial improvement in PCE of 5.01% compared to 3.25% of the pristine device was obtained. The optical and electrical properties of the fabricated devices were carried out. Also, the structural properties of the nanoparticle composite were established.
Cell‐free DNA for Down syndrome screening in obese women: Is it a cost‐effective strategy?
Authors: Hopkins Maeve K. , Dugoff Lorraine , Durnwald Celeste , Havrilesky Laura J. , Dotters‐Katz Sarah
Published: December 2019

Objective

Determine cost differences between cell‐free DNA (cfDNA) and serum integrated screening (INT) in obese women given the limitations of aneuploidy screening in this population.

Methods

Using a decision‐analytic model, we estimated the cost‐effectiveness of trisomy 21 screening in class III obese women using cfDNA compared with INT. Primary outcomes of the model were cost, number of unnecessary invasive tests, procedure‐related fetal losses, and missed cases of trisomy 21.

Results

In base case, the mean cost of cfDNA was $498 greater than INT ($1399 vs $901). cfDNA resulted in lower probabilities of unnecessary invasive testing (2.9% vs 3.5%), procedure‐related loss (0.015% vs 0.019%), and missed cases of T21 (0.00013% vs 0.02%). cfDNA cost $87 485 per unnecessary invasive test avoided, $11 million per procedure‐related fetal loss avoided, and $2.2 million per missed case of T21 avoided. In sensitivity analysis, when the probability of insufficient fetal fraction is assumed to be >25%, cfDNA is both costlier than INT and results in more unnecessary invasive testing (a dominated strategy).

Conclusion

When the probability of insufficient fetal fraction more than 25% (a maternal weight of ≥300 lbs), cfDNA is costlier and results in more unnecessary invasive testing than INT.
Opening the black box of the group‐based trajectory modeling process to analyze medication adherence patterns: An example using real‐world statin adherence data
Authors: Hickson Ryan P. , Annis Izabela E. , Killeya‐Jones Ley A. , Fang Gang
Published: December 2019

Purpose

The rationale for choosing a final group‐based trajectory modeling (GBTM) specification and evaluations of patient adherence patterns within groups are often omitted in the GBTM medication adherence literature. We aimed to (1) reveal the complexity of GBTM and (2) assess model discrimination of patient medication adherence patterns.

Methods

Medicare administrative claims were used to measure statin medication adherence as a continuous value in the 6 months before an acute myocardial infarction (AMI) hospitalization. Different GBTM specifications beyond default settings were constructed and compared with the Bayesian information criterion. Spaghetti plots were used to compare individual adherence patterns with group averages.

Results

Overall, 113,296 prevalent statin users met eligibility criteria. Four adherence groups were identified: persistently adherent, moderately adherent, progressively nonadherent, and persistently nonadherent. Spaghetti plots showed the persistently adherent and persistently nonadherent groups had relatively homogeneous adherence patterns that matched predicted trajectories well. Spaghetti plots also showed that, while adherence patterns in the progressively nonadherent group were not as homogeneous, most patients in this group appeared to be discontinuing statin therapy pre‐AMI.

Conclusions

Subjective decisions are necessary to identify a final trajectory model. Greater transparency and disclosure of these decisions in the medication adherence literature are needed. Individual patient adherence patterns from spaghetti plots provided additional diagnostic information about trajectory models beyond standard model‐fit assessments to determine if group‐average adherence estimates represent homogeneous patterns of medication adherence.
Monitoring permafrost and periglacial processes in Sierra Nevada (Spain) from 2001 to 2016
Authors: Gómez‐Ortiz Antonio , Oliva Marc , Salvador‐Franch Ferran , Palacios David , Tanarro Luis Miguel , de Sanjosé‐Blasco José Juan , Salvà‐Catarineu Montserrat
Published: December 2019

Outside the Alps, the Sierra Nevada is probably the best studied European massif with respect to its past and current environmental dynamics. A multi‐approach research program started in the early 2000s focused on the monitoring of frozen ground conditions in this National Park. Here, we present data on the thermal state and distribution of permafrost and seasonal frozen ground in different sites across the highest areas of the massif. New results confirm the absence of widespread permafrost conditions, with seasonal frost prevailing above 2500 m. Small permafrost patches have been only detected in glaciated areas of the Veleta and Mulhacén cirques during the Little Ice Age at elevations of 3000–3100 m. The remnants of those glaciers are still preserved under the thick debris layer covering the cirque floors. Geomatic and geophysical surveying of a rock glacier existing in the Veleta cirque, together with the monitoring of soil temperature at different depths, have revealed permanently frozen conditions undergoing a process of degradation. In the rest of the massif, a seasonal frost regime prevails, even at the highest plateaus at 3300–3400 m, where annual soil temperatures average 2.5°C. The monitoring of soil temperatures in other different periglacial features has also revealed positive average values ranging between 2°C (inactive sorted‐circles) and 3–4°C (inactive and weakly active solifluction lobes). Consequently, we conclude that the present‐day climatic regime does not allow the existence of permafrost in the Sierra Nevada, and environmental dynamics is controlled by the intensity and duration of seasonal frost in the ground.
Impact of road proximity on infants and children with bronchopulmonary dysplasia
Authors: Collaco Joseph M. , Morrow Michael , Rice Jessica L. , McGrath‐Morrow Sharon A.
Published: December 2019

Introduction

Infants born prematurely are at high risk for morbidities, including lung disease (bronchopulmonary dysplasia [BPD]). Little is known regarding environmental factors that can impact outcomes in BPD. We sought to assess the role of traffic‐related air pollution (TRAP) on respiratory outcomes in BPD.

Methods

A total of 784 subjects were included from the Johns Hopkins BPD clinic. Caregivers completed questionnaires on environmental exposures and respiratory outcomes (acute care use and chronic symptoms). Distance to the nearest major roadway was derived from subjects’ geocoded residential addresses.

Results

Approximately half of the subjects (53.8%) lived within 500 m of a major roadway. Subjects who lived within 500 m of a major roadway were more likely to be non‐white (P = .006), have a lower estimated household income (P < .001) and live in more densely populated zip codes (P < .001) than those who lived further than 500 m away. For every 1 km increase in distance between residence and roadway, the likelihood of activity limitations decreased by 35% (P = .005). No differences in acute care use were seen with proximity to major roadways.

Conclusions

Proximity to a major roadway was associated with chronic respiratory symptoms, such as activity limitations (eg, dyspnea), and tended to be associated with nighttime symptoms as well. Self‐reported minorities and families with lower estimated household incomes may be more likely to be exposed to TRAP. Further research is necessary to define the effects of TRAP versus other sources of indoor and outdoor air pollution as well as to determine the best ways of combatting pollution‐related respiratory morbidities.
Reunifying and separating: An analysis of residential arrangements of migrant couples in Ouagadougou, Burkina Faso
Authors: Flahaux Marie‐Laurence , Wayack‐Pambè Madeleine , Soura Abdramane Bassiahi , Compaoré Yacouba , Sanogo Souleymane
Published: December 2019

This paper offers new evidence on the residential arrangements of couples in the context of migration and urbanisation in Africa, focusing on the case of Ouagadougou, Burkina Faso's capital city. We use a mixed‐methods approach, combining data from a survey on the family histories of migrants merged with data from the Ouagadougou Health and Demographic Surveillance System and qualitative interviews. The objective is to analyse how the migrants themselves perceive “living apart together”, the extent of this phenomenon, its timing, and the factors influencing it. The longitudinal nature of our data specifically allows for the study of the drivers of couple reunification in Ouagadougou and of the physical separation of partners, whereby one goes to live away from Ouagadougou. Our results reveal that 25% of migrants in a union had a partner living outside Ouagadougou in 2015, and that the residential arrangements of such couples were associated with gender relations, family cycle, and integration into the city.
Oxygen Vacancy Mediated Stabilization of Cubic Phase at Room Temperature and Resistive Switching Effect in Sm‐ and Dy‐Doped HfO2 Thin Film
Authors: Kumar Sandeep , Rath Chandana
Published: December 2019

Recently, binary transition metal oxide‐based resistive random access memory (RRAM) has been attracted for future nonvolatile data storage devices. Herein, the structural evolution and resistive switching behavior of pristine and Sm‐ or Dy‐doped hafnium oxide (HfO2) films of ≈60 nm deposited on p++‐Si (100) substrates through electron‐beam evaporation technique are systematically investigated. Although it is reported that 12 at% of Sm or 11 at% of Dy doped in HfO2 nanoparticles stabilize the high‐temperature cubic phase at RT, herein, the stabilization of cubic phase after doping at most half of these dopant concentration is demonstrated. Furthermore, these films exhibit the bipolar switching behavior distinctive to RRAM device. Interestingly, the resistive switching characteristics are found to be of forming‐free nature. To understand the switching behavior, different conduction models such as the Ohmic and Poole–Frenkel emission are used. The monoclinic to cubic phase transformation and resistive switching phenomenon are discussed in terms of the abundant formation of oxygen vacancies producing eightfold oxygen coordination to Sm3+ or Dy3+ ion evidenced from photoluminescence and X‐ray photoelectron spectroscopy. The resistive switching mechanism through the formation of conducting filaments is pictorially illustrated in HfO2‐based RRAM.
Relationship Between Li/Ce Concentration and the Luminescence Properties of Codoped Gd3(Ga, Al)5O12:Ce
Authors: Yoshino Masao , Bartosiewicz Karol , Horiai Takahiko , Kamada Kei , Yamaji Akihiro , Shoji Yasuhiro , Yokota Yuui , Kurosawa Shunsuke , Ohashi Yuji , Sato Hiroki , Toyoda Satoshi , Kucerkova Romana , Jary Vitezslav , Nikl Martin , Yoshikawa Akira
Published: December 2019

Li+ codoping of Gd3(Ga, Al)5O12:Ce (GGAG:Ce) single crystals induces the acceleration of scintillation decay time. However, its effect on the scintillation properties of GGAG:Ce remains poorly understood. Herein, the relationship between Ce/Li concentration and scintillation properties is investigated. GGAG crystals with a range of Ce and Li concentrations are grown by the Czochralski method and the scintillation decay and light output of GGAG:Ce, Li are measured. The results show comparable or improved performance compared with conventional scintillators. In optical absorption and photoluminescence (PL) measurements, the conversion of the stable Ce3+ to Ce4+ is not observed in a clear manner in GGAG:Ce samples with variable Li concentration. Instead, some defect‐related absorption seems to appear. Temperature dependence of PL decay for samples with variable Ce concentration is also evaluated. A shift of the luminescence quenching temperature is observed for GGAG samples with >0.2% Ce.
High Quality, Mass‐Producible Semipolar GaN and InGaN Light‐Emitting Diodes Grown on Sapphire
Authors: Song Jie , Han Jung
Published: December 2019

The heteroepitaxy efforts to grow semipolar and nonpolar GaN on foreign substrates of the past 20 years are reviewed and summarized. With the demonstration of three representative semipolar GaN grown on sapphire, the capability to produce semipolar GaN with any orientation on sapphire is exhibited. Also, a unique growth technology called facet‐engineered orientation‐controlling growth to eliminate the stacking faults (SFs) in semipolar GaN is developed and SF‐free (201) GaN grown on sapphire is presented, demonstrating the capability of producing device‐quality, large‐area semipolar GaN. InGaN green light‐emitting diodes (LEDs) grown on the SF‐free semipolar (201) GaN/sapphire templates are performed with much higher external quantum efficiency in comparison with the typical semipolar/nonpolar LEDs heteroepitaxially grown on foreign substrates reported before.
Toward a standardised protocol for the stable isotope analysis of scleractinian corals
Authors: Sturaro Nicolas , Hsieh Yunli Eric , Chen Qi , Wang Pei‐Ling , Denis Vianney
Published: December 2019

Rationale

The stable isotope analysis of carbon and nitrogen is a powerful tool in many ecological studies, but different sample treatments may affect stable isotope ratios and hamper comparisons among studies. The goal of this study was to determine whether treatments that are commonly used to prepare scleractinian coral samples for stable isotope analysis yield different δ15N and δ13C values, and to provide guidelines toward a standardised protocol.

Methods

The animal tissues and Symbiodiniaceae of two symbiotic scleractinian coral species (Stylophora pistillata and Porites lutea) were divided into subsamples to test the effects of the drying method, lipid extraction, acidification treatment and water washing. All the subsamples were analysed for their δ15N and δ13C values, using continuous flow elemental analyser/isotope ratio mass spectrometry.

Results

The drying method and lipid extraction treatment had no substantial effects on the δ15N and δ13C values of Symbiodiniaceae and animal tissues. Acid treatment did cause significant differences in δ13C values (mean differences ≤0.5‰, with individual samples becoming up to 2.0‰ more negative), whereas no ecologically significant differences were observed in δ15N values. Animal tissue δ13C values may vary depending on whether samples are washed or not.

Conclusions

To move towards a standardised protocol in coral research, we recommend using an available drying method (as they are equally acceptable) for the stable isotope analysis of scleractinian corals, examining the need for lipid extraction on a case‐by‐case basis, performing a direct acidification of Symbiodiniaceae and animal tissues, and avoiding washing animal tissue with distilled water.
Simple limbal epithelial transplantation: Current status and future perspectives
Authors: Jackson Catherine J. , Myklebust Ernø Inger T. , Ringstad Håkon , Tønseth Kim A. , Dartt Darlene A. , Utheim Tor P.
Published: December 2019

Damage to limbal stem cells as a result of injury or disease can lead to limbal stem cell deficiency (LSCD). This disease is characterized by decreased vision that is often painful and may progress to blindness. Clinical features include inflammation, neovascularization, and persistent cornea epithelial defects. Successful strategies for treatment involve transplantation of grafts harvested from the limbus of the alternate healthy eye, called conjunctival-limbal autograft (CLAU) and transplantation of limbal cell sheets cultured from limbal biopsies, termed cultured limbal epithelial transplantation (CLET). In 2012, Sangwan and colleagues presented simple limbal epithelial transplantation (SLET), a novel transplantation technique that combines the benefits of CLAU and CLET and avoids the challenges associated with both. In SLET a small biopsy from the limbus of the healthy eye is divided and distributed over human amniotic membrane, which is placed on the affected cornea. Outgrowth occurs from each small explant and a complete corneal epithelium is typically formed within 2 weeks. Advantages of SLET include reduced risk of iatrogenic LSCD occurring in the healthy cornea at harvest; direct transfer circumventing the need for cell culture; and the opportunity to perform biopsy harvest and transplantation in one operation. Success so far using SLET is comparable with CLAU and CLET. Of note, 336 of 404 (83%) operations using SLET resulted in restoration of the corneal epithelium, whereas visual acuity improved in 258 of the 373 (69%) reported cases. This review summarizes the results of 31 studies published on SLET since 2012. Progress, advantages, challenges, and suggestions for future studies are presented.

Significance statement The present review examines work reporting simple limbal epithelial transplantation (SLET), an innovative technique that uses minimal limbal tissue from the healthy eye to regenerate the cornea in the limbal deficient diseased eye. Results since the introduction of SLET in 2012 suggest that the success rate is comparable to established techniques, conjunctival-limbal autograft and cultured limbal epithelial transplantation. However, SLET has the advantages of requiring a smaller biopsy, achieving harvest and transplantation in a single operation, and the unnecessity of cell culture laboratories. AlloSLET, a novel modification of SLET using allogeneic tissue, promises to further improve outcome through promotion of early resolution of inflammation in the injured/diseased eye.
Causal inference with noisy data: Bias analysis and estimation approaches to simultaneously addressing missingness and misclassification in binary outcomes
Authors: Shu Di , Yi Grace Y.
Published: December 2019

Causal inference has been widely conducted in various fields and many methods have been proposed for different settings. However, for noisy data with both mismeasurements and missing observations, those methods often break down. In this paper, we consider a problem that binary outcomes are subject to both missingness and misclassification, when the interest is in estimation of the average treatment effects (ATE). We examine the asymptotic biases caused by ignoring missingness and/or misclassification and establish the intrinsic connections between missingness effects and misclassification effects on the estimation of ATE. We develop valid weighted estimation methods to simultaneously correct for missingness and misclassification effects. To provide protection against model misspecification, we further propose a doubly robust correction method which yields consistent estimators when either the treatment model or the outcome model is misspecified. Simulation studies are conducted to assess the performance of the proposed methods. An application to smoking cessation data is reported to illustrate the use of the proposed methods.
Cu(NO3)2/Oxone‐Mediated Radical Nitration Cyclization of 1,6‐Enynes
Authors: Song Si‐Zhe , Kang Qing‐Qing , Cao Ting‐Ting , Lei Ke‐Wei , Liu Yan‐Yun , Li Qiang , Wei Wen‐Ting
Published: December 2019

Herein we report a protocol for commercial available oxone‐mediated nitration cyclization between 1,6‐enynes and Cu(NO3)2. This strategy shows attractive characteristics such as mild reaction conditions, operational simplicity, broad substrates scope with good to excellent yields and high functional group tolerance. The reaction provides a regioselective way toward the formation of a new C−N and C−C bonds in one step. Mechanistic studies reveal that the procedure undergoes a radical process.
Identification and Screening of Selective WEE2 Inhibitors to Develop Non‐Hormonal Contraceptives that Specifically Target Meiosis
Authors: Hanna Carol B. , Yao Shan , Martin Mat , Schönbrunn Ernst , Georg Gunda I. , Jensen Jeffrey T. , Cuellar Rebecca A. D.
Published: December 2019

We used a progressive elimination strategy to identify oocyte‐specific WEE2 kinase inhibitors for potential non‐hormonal contraceptives that target meiosis. Beginning with an in‐house library of over 300,000 compounds, virtual high throughput screening identified 57 WEE2 inhibitors with preferential predicted binding over the somatic variant WEE1.  Seven compounds were further evaluated in vitro by enzyme‐linked immunosorbent assay to measure biochemical inhibition on WEE1 and WEE2 phosphorylation of CDK1. To assess specificity, we evaluated WEE2‐mediated inhibition of meiosis using in vitro oocyte fertilization, and WEE1‐mediated inhibition of mitosis using a somatic cell proliferation assay.  Our results from these assays identified three candidates for further development: 6‐(2,6‐dichlorophenyl)‐2‐((4‐(2‐(diethylamino)ethoxy) phenyl)amino)‐8‐methylpyrido[2,3‐d]pyrimidin‐7(8H)‐one (2), 6‐(2,6‐dichlorophenyl)‐8‐methyl‐2‐((4‐morpholinophenyl)amino)pyrido[2,3‐d]pyrimidin‐7(8H)‐one (12), and 3‐((6‐(2,6‐dichlorophenyl)‐8‐methyl‐7‐oxo‐7,8‐dihydropyrido[2,3‐d]pyrimidin‐2‐yl)amino)benzoic acid (16).
Understanding the Mechanism of Nitrobenzene Nitration with Nitronium Ion: A Molecular Electron Density Theory Study
Authors: Cyrille Nana Nouhou , Idrice Adjieufack Abel , Maraf Mbah Bake , Charles Fon Abi , Ibrahim Mbouombouo Ndassa , Ríos‐Gutierrez Mar , Domingo Luis Ramon
Published: December 2019

The nitration reaction of nitrobenzene with nitronium ion yielding ortho‐, meta‐ and para‐dinitrobenzenes has been studied within the Molecular Electron Density Theory, using DFT computational methods at the B3LYP/6‐311G(d,p) level. This electrophilic aromatic substitution (EAS) reaction takes place through a two‐step mechanism involving the formation of a tetrahedric cation intermediate. The electrophilic attack of nitronium ion on nitrobenzene is the rate‐determining step of this EAS reaction, and consequently, responsible for the composition of the reaction mixture. The subsequent proton abstraction from the cation intermediate is barrierless. From the computed activation Gibbs free energies, a relationship 11.0 (ortho) : 87.3 (meta) : 1.7 (para) of the dinitrobenzenes is estimated, in clear agreement with the experimental outcome. The similar nucleophilic activation of the ortho and meta carbons of nitrobenzene makes it possible to question the hypothesis for the orientation in EAS reactions involving nucleophilically deactivated benzenes based on the relative stability of the tetrahedric cation intermediates.
Biodegradable Bi2O2Se Quantum Dots for Photoacoustic Imaging‐Guided Cancer Photothermal Therapy
Authors: Xie Hanhan , Liu Mingqiang , You Baihao , Luo Guanghong , Chen Yue , Liu Bilu , Jiang Zhenyou , Chu Paul K. , Shao Jundong , Yu Xue‐Feng
Published: December 2019

As new 2D layered nanomaterials, Bi2O2Se nanoplates have unique semiconducting properties that can benefit biomedical applications. Herein, a facile top‐down approach for the synthesis of Bi2O2Se quantum dots (QDs) in a solution is described. The Bi2O2Se QDs with a size of 3.8 nm and thickness of 1.9 nm exhibit a high photothermal conversion coefficient of 35.7% and good photothermal stability. In vitro and in vivo assessments demonstrate that the Bi2O2Se QDs possess excellent photoacoustic (PA) performance and photothermal therapy (PTT) efficiency. After systemic administration, the Bi2O2Se QDs accumulate passively in tumors enabling efficient PA imaging of the entire tumors to facilitate imaging‐guided PTT without obvious toxicity. Furthermore, the Bi2O2Se QDs which exhibit degradability in aqueous media not only have sufficient stability during in vivo circulation to perform the designed therapeutic functions, but also can be discharged harmlessly from the body afterward. The results reveal the great potential of Bi2O2Se QDs as a biodegradable multifunctional agent in medical applications.
Viable system function and construction design methodology
Authors: Mouhib Nora , Bah Slimane , Berrado Abdelaziz
Published: December 2019

In this paper, the authors propose a new methodology relative to earlier work on the Viable System Ontology Theory. This theory links Beer's Viability theory and Dietz's Performance in Social Interaction (PSI) theory and aims at supporting the business process design of a viable system. This work extends the Viable System Ontology Theory by a detailed methodology that alternates the VSM functional diagnosis and design with the construction design as recommended by the Generic System Development Process (GSDP). The proposed methodology consists of three iterative phases: the environment construction, the function design, and the construction design of a viable system. Those steps are discussed in the light of the Viable System Ontology Theory propositions. In addition, they are illustrated by the case study of the Moroccan public medicine procurement system.
Second Language Teacher Education in Response to Local Needs: Preservice Teachers of English Learning to Teach Diverse Learners in Communities
Authors: Nguyen Chinh Duc , Dang Tu Cam Thi
Published: December 2019

Second language teacher education (SLTE) has changed its focus from cognitive to sociocultural perspectives. By considering located SLTE and community learning, this qualitative study was conducted to explore how preservice teachers of English as a foreign language learned to teach in response to learning needs in a Vietnamese city. Data sources for the study were written assignments produced by preservice teachers and in‐depth interviews with them. Through their engagement in the local community, the preservice teachers identified nine groups of adult learners who were not able to gain access to English learning in the formal schooling system. Those learners sought to learn English not only to meet their personal and professional needs but also to contribute to socioeconomic development of the local community. Based on the findings regarding the local learners’ needs and characteristics, the preservice teachers developed pedagogical practices appropriate to each specific group of learners and suggested that university‐based SLTE programmes should embrace diverse learners and community‐based teacher learning. The study substantiates the concept of located SLTE and offers some implications for SLTE in response to local needs.
Modification of Potassium Chabazites Derived from Fly Ash by Dosing Extra Cations: Promoted CO2 Adsorption Capacities and Fine‐Tuned Frameworks
Authors: Che Shuai , Fang Xin , Li Siyang , Chen Xudong , Du Tao
Published: December 2019

Potassium chabazite (K‐CHA), a typical microporous zeolite with excellent CO2 separating properties, was synthesized with waste fly ash and modified via cation dosing treatments using cesium and zinc cations, respectively. The resulting CHAs were analyzed by XRF, XRD, FT‐IR, SEM, and N2 physisorption, whose CO2 adsorption properties were then tested on the reorganized TGA apparatus. It showed from XRF data that cesium and zinc cations were successfully imported in the original K‐CHA by cation dosing, but the CHA microstructures and morphologies of K‐CHA were perfectly retained as confirmed by XRD, FT‐IR, SEM and N2 physisorption. Since there were still over 9 potassium cations per unit cell in cation dosed Cs‐CHA and Zn‐CHA, they both maintained the favored properties of K‐CHA as “molecular trapdoors”. In the following adsorption experiments, the CO2 uptakes of Cs‐CHA and Zn‐CHA at 333 K and 1 bar, compared with K‐CHA, elevated from 1.70 mmol·g–1 to 2.34 and 2.03 mmol·g–1, and the import of zinc cation also presented a positive effect on the adsorption kinetics. Detailed comparisons suggested modifications with cesium and zinc cations fine‐tune the CHA complying with different mechanisms, and CHAs modified via cation perform more approvingly than fully ion‐exchanged ones, providing us important insights into CHA modifications and applications in practice.
Quantum tunnelling, real-time dynamics and Picard-Lefschetz thimbles
Authors: Mou Zong-Gang , Saffin Paul M. , Tranberg Anders
Published: December 2019

Abstract

We follow up the work, where in light of the Picard-Lefschetz thimble approach, we split up the real-time path integral into two parts: the initial density matrix part which can be represented via an ensemble of initial conditions, and the dynamic part of the path integral which corresponds to the integration over field variables at all later times. This turns the path integral into a two-stage problem where, for each initial condition, there exits one and only one critical point and hence a single thimble in the complex space, whose existence and uniqueness are guaranteed by the characteristics of the initial value problem. In this paper, we test the method for a fully quantum mechanical phenomenon, quantum tunnelling in quantum mechanics. We compare the method to solving the Schrödinger equation numerically, and to the classical-statistical approximation, which emerges naturally in a well-defined limit. We find that the Picard-Lefschetz result matches the expectation from quantum mechanics and that, for this application, the classical-statistical approximation does not.
On one loop corrections in higher spin gravity
Authors: Ponomarev Dmitry , Sezgin Ergin , Skvortsov Evgeny
Published: December 2019

Abstract

We propose an approach to compute one-loop corrections to the four-point amplitude in the higher spin gravities that are holographically dual to free O(N), U(N) and USp(N) vector models. We compute the double-particle cut of one-loop diagrams by expressing them in terms of tree level four-point amplitudes. We then discuss how the remaining contributions to the complete one-loop diagram can be computed. With certain assumptions we find nontrivial evidence for the shift in the identification of the bulk coupling constant and 1/N in accordance with the previously established result for the vacuum energy.
Reevaluating uncertainties in $$ \overline{B} $$ → Xsγ decay
Authors: Gunawardana Ayesh , Paz Gil
Published: December 2019

Abstract

The rare decay $$ \overline{B} $$

B
¯

→ Xsγ is an important probe of physics beyond the standard model. The largest uncertainty on the total rate and the CP asymmetry arises from resolved photon contributions. These appear first at order 1/mb and are related to operators other than Q7γ in the effective weak Hamiltonian. One of the three leading contributions, $$ {Q}_1^q-{Q}_{7\gamma } $$

Q
1
q

−

Q

7
γ

, is described by a non-local function whose moments are related to HQET parameters. We use recent progress in our knowledge of these parameters to reevaluate the resolved photon contribution to $$ \overline{B} $$

B
¯

→ Xsγ total rate and CP asymmetry.
Seesaw neutrinos with one right-handed singlet field and a second Higgs doublet
Authors: Jurčiukonis D. , Gajdosik T. , Juodagalvis A.
Published: December 2019

Abstract

We study parameters of an extension of the Standard Model. The neutrino sector is enlarged by one right-handed singlet field, allowing for the seesaw mechanism type-I, and the Higgs sector contains one additional doublet, which contributes to light neutrino masses through one-loop radiative corrections. Employing an approximation for the effective light neutrino mass matrix we express the masses of the light neutrinos analytically, allowing us to parameterize the Yukawa couplings to neutrinos by the experimental measurements on the neutrino sector and only two free parameters. We focus on a CP-conserving Higgs potential for which we present the allowed ranges of the input parameters and a statistical overview over the possible values of the Yukawa couplings.
Phenomenology of GeV-scale scalar portal
Authors: Boiarska Iryna , Bondarenko Kyrylo , Boyarsky Alexey , Gorkavenko Volodymyr , Ovchynnikov Maksym , Sokolenko Anastasia
Published: December 2019

Abstract

We review and revise the phenomenology of the scalar portal — a new scalar particle with the mass in GeV range that mixes with the Higgs boson. In particular, we consider production channels B → SK1(1270) and $$ B\to S{K}_0^{\ast }(700) $$
B
→
S

K
0
∗

700

and show that their contribution is significant. We extend the previous analysis by comparing the production of scalars from decays of mesons, of the Higgs bosons and direct production via proton bremsstrahlung, deep inelastic scattering and coherent scattering on nuclei. Relative efficiency of the production channels depends on the energy of the beam and we consider the energies of DUNE, SHiP and LHC-based experiments. We present our results in the form directly suitable for calculations of experimental sensitivities.
Special Galileon at one loop
Authors: Přeučil Filip , Novotný Jiří
Published: December 2019

Abstract

We present a complete one-loop renormalization of the Special Galileon S­matrix. Especially, we give a complete list of the higher derivative operators which are necessary for the one-loop on-shell renormalization and prove the invariance of the one­loop on-shell effective action with respect to the Special Galileon symmetry. This enables us to enlarge the validity of the enhanced O(p3) soft behavior of the scattering amplitudes to the one-loop level. As an illustration, we discuss explicitly the four-point and five-point one-loop scattering amplitudes and comment on some conjectures appearing in the existing literature.
Hexagons and correlators in the fishnet theory
Authors: Basso Benjamin , Caetano João , Fleury Thiago
Published: December 2019

Abstract

We investigate the hexagon formalism in the planar 4d conformal fishnet theory. This theory arises from $$ \mathcal{N} $$
N
= 4 SYM by a deformation that preserves both conformal symmetry and integrability. Based on this relation, we obtain the hexagon form factors for a large class of states, including the BMN vacuum, some excited states, and the Lagrangian density. We apply these form factors to the computation of several correlators and match the results with direct Feynman diagrammatic calculations. We also study the renormalisation of the hexagon form factor expansion for a family of diagonal structure constants and test the procedure at higher orders through comparison with a known universal formula for the Lagrangian insertion.
Quantum corrections to the BTZ black hole extremality bound from the conformal bootstrap
Authors: Maxfield Henry
Published: December 2019

Abstract

Any unitary compact two-dimensional CFT with c > 1 and no symmetries beyond Virasoro has a parametrically large density of primary states at large spin for

$$ \overline{h} $$

h
¯

>

$$ {\overline{h}}_{\mathrm{extr}} $$

h
¯

extr

∼

$$ \frac{c-1}{24} $$

c
−
1

24

, of a universal form determined by modular invariance. By including the contribution of light primary operators and multi-twist composites constructed from them in the modular bootstrap, we find that

$$ {\overline{h}}_{\mathrm{extr}} $$

h
¯

extr

receives corrections in a large spin expansion, which we compute at finite c. The analysis uses a formulation of the modular S-transform as a Fourier transform acting on the density of primary states. For theories with gravitational duals,

$$ {\overline{h}}_{\mathrm{extr}} $$

h
¯

extr

is interpreted as the extremality bound of rotating BTZ black holes, receiving quantum corrections which we compute at one loop by prohibiting naked singularities in the quantum-corrected geometry. This gravity result is reproduced by modular bootstrap in a semiclassical c → ∞ limit.