bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and genetic analysis of thalassemia in childbearing age population of Hainan, The Free Trade Island in Southern China
Authors: Wang Min , Zhang Xiaozhuang , Zhao Yanhong , Lu Zhe , Xiao Meifang
Published: February 2022

Background

Hainan has one of the high incidences of thalassemia in China, but the epidemiological data in the whole province has not been reported yet. The objective of our study was to reveal the true prevalence and molecular mutation spectrum of thalassemia in the population of Hainan who are of childbearing age.

Methods

We screened 166,936 individuals from 19 cities and counties in Hainan by hematological parameters analysis, and further conducted genetic analysis for individuals whose MCV was less than 82fL.

Results

In total, 21,619 (12.95%) subjects were diagnosed as thalassemia carriers or patients. The overall prevalence of α‐thalassemia, β‐thalassemia, and α+β‐thalassemia were 10.39%, 1.38%, and 1.18%, respectively. Eleven α‐thalassemia mutations and sixteen β‐thalassemia mutations were identified. The high‐frequent genotypes of α‐thalassemia were ‐α3.7/αα (19.70%), ‐α4.2/αα (19.39%), αα/‐‐SEA (15.60%), αWSα/αα (9.24%), and ‐α3.7/‐α4.2 (8.90%), and those of β‐thalassemia were βCD41/42(−TTCT)/βN (58.92%), β−28(A>G)/βN (16.05%), βIVS−Ⅱ−654(C>T)/βN (8.42%), βCD71/72(+A)/βN (6.03%), βCD17(A>T)/βN (5.47%), and βCD26 (GAG>AAG)/βN (2.69%). In addition, the frequencies and hematological profiles of many rare mutations of α‐ [Fusion, HKαα, αααanti4.2, IVS‐II‐55 (T>G), IVS‐II‐119 (−G,+CTCGGCCC)] and β‐globin genes [−50 (G>A), IVS‐Ⅱ‐81 (C>T)] in Hainan were reported for the first time.

Conclusion

Our study revealed the high prevalence and extensive molecular spectrum of thalassemia in childbearing age population of Hainan, suggesting thalassemia in Hainan ranks second in prevalence among all regions in China. The findings will be useful for genetic counseling and prevention of thalassemia.
Post‐surgical emergency after‐hours calls: Prevalence, concerns, and management
Authors: Kofina Vrisiis , Lindholm Drake , Harunani Abdulkareem , Dentino Andrew R. , Singh Maharaj , Tatakis Dimitris N.
Published: February 2022

Objective

The purpose of this study was to investigate the prevalence, nature, and management of post‐surgical emergency after‐hours calls in a dental school setting with predoctoral students, graduate students/residents, and faculty providers.

Methods

A patient chart review (March 2018–February 2020) for post‐surgical calls through the emergency after‐hours pager system was conducted at the Marquette University School of Dentistry. The total number of surgical procedures, procedure type, the timing of call, operator experience, concern, and recommendation given during the call were documented.

Results

During the review period, 83 calls (from 75 patients) were recorded after 8,487 surgical procedures (1% of procedures). Patients called 5.4 ± 0.8 days postoperatively. Procedure type affected call prevalence (p = 0.04), with most calls made after extractions (69.9% of all calls; 1% of extractions; 58/5,725), implant placement (6%; 0.9% of implant placements; 5/530) and periodontal plastic surgery (6%; 3.1% of all plastic surgeries; 5/161). The most common concern was pain (72.3%), then swelling (36.1%), bleeding (12%), and infection (9.6%). Operator experience did not affect call prevalence. Recommendations given were next business day follow‐up (79.5%), reinforcement of already given postoperative instructions (51.8%), prescription (15.7%), and hospital emergency department (ED) visit (7.2%).

Conclusions

Post‐surgical emergency after‐hours calls in a dental school setting occur within the first postoperative week and are rare, unrelated to operator experience, typically prompted by pain, and rarely resulting in referral to hospital ED. The use of a pager system is adequate for the management of after‐hours emergencies and may reduce self‐referrals to the hospital ED.
Oral medicine education in predoctoral programs in US dental schools
Authors: Bajonaid Amal M. , Park Sang E. , Villa Alessandro
Published: February 2022

Objective

the purpose of the study was to explore the structure of oral medicine (OM) education in predoctoral dental programs in the United States and to evaluate the students’ perception of OM as a dental specialty.

Methods

Two anonymous Qualtrics surveys (Qualtrics, Provo, UT, USA) were distributed electronically to the academic deans of all the Commission on Dental Accreditation (CODA) accredited dental schools in the United States. Upon completing the survey, the academic deans were asked to forward the student surveys to their students.

Results

Note that 26.8% (18/67 dental schools) of academic deans that participated in the survey, 224 senior students responded to the student survey. The results showed that the median number of OM specialists involved in teaching OM to predoctoral students was two. Oral cancer screening and diagnosis and management of oral mucosal diseases were identified by the majority of respondents (95.7%; n = 214 and 96.5%; n = 216), respectively, as part of the scope of practice of OM specialists. Although most students reported Advanced Education in General Dentistry (AEGD) and General Practice Residency (GPR) (18.67% n = 42 each) as postgraduate specialties of interest, students’ positive impression in OM increased by a crude average of 0.4 with each additional OM faculty member in the school (p = 0.000; 95% CI 0.207–0.594).

Conclusion

OM faculty members are in an important position to enhance dental students’ perception and interest in OM as a specialty, which would lead to improved awareness of the scope of the specialty and consideration of pursuing specialty training.
Optimization of small extracellular vesicle isolation from expressed prostatic secretions in urine for in‐depth proteomic analysis
Authors: Correll Vanessa L. , Otto Joseph J. , Risi Cristina M. , Main Brian P. , Boutros Paul C. , Kislinger Thomas , Galkin Vitold E. , Nyalwidhe Julius O. , Semmes O. John , Yang Lifang
Published: February 2022

The isolation and subsequent molecular analysis of extracellular vesicles (EVs) derived from patient samples is a widely used strategy to understand vesicle biology and to facilitate biomarker discovery. Expressed prostatic secretions in urine are a tumor proximal fluid that has received significant attention as a source of potential prostate cancer (PCa) biomarkers for use in liquid biopsy protocols. Standard EV isolation methods like differential ultracentrifugation (dUC) co‐isolate protein contaminants that mask lower‐abundance proteins in typical mass spectrometry (MS) protocols. Further complicating the analysis of expressed prostatic secretions, uromodulin, also known as Tamm‐Horsfall protein (THP), is present at high concentrations in urine. THP can form polymers that entrap EVs during purification, reducing yield. Disruption of THP polymer networks with dithiothreitol (DTT) can release trapped EVs, but smaller THP fibres co‐isolate with EVs during subsequent ultracentrifugation. To resolve these challenges, we describe here a dUC method that incorporates THP polymer reduction and alkaline washing to improve EV isolation and deplete both THP and other common protein contaminants. When applied to human expressed prostatic secretions in urine, we achieved relative enrichment of known prostate and prostate cancer‐associated EV‐resident proteins. Our approach provides a promising strategy for global proteomic analyses of urinary EVs.
Predictors of colorectal carcinoma and inflammatory bowel disease in patients with colonic wall thickening
Authors: Pothoulakis Ioannis , Wikholm Colin , Verma Vipin , Ahmad Akram I , Vangimalla Shiva S , Patel Harshkumar , Oh Jae H , Zhao Alex , Gress Kyle L , Bovill John , Deshpande Nikita , Marquez Maria , Dean Brynley , Gholson Dwight A , Bhogal Loveleen , Buchanan Faith , Cho Won Kyoo
Published: February 2022

Background and Aim

Colonic wall thickening (CWT) is commonly associated with clinically significant pathologies, but predictive factors of such pathologies are not well known. This study aims to identify the predictors of clinically significant pathologies, such as colorectal carcinoma (CRC) and inflammatory bowel disease (IBD), in patients with CWT.

Methods

Subjects with an abnormal abdominal computed tomography (CT) and a follow‐up colonoscopy between 2010 and 2020 were retrospectively reviewed. Patients with CWT in the CT were included and examined in this study. A multivariable logistic regression analysis was performed to assess for factors independently associated with CRC or IBD in these subjects. Receiver operating characteristic (ROC) curve analysis was used to further examine significant parameters in multivariable logistic regression analysis.

Results

Among 403 patients with CWT on CT scans who underwent a colonoscopy, 269 subjects who met the inclusion criteria were identified and studied. On multivariable logistic regression models, elevated platelet count, low hematocrit, and localized CWT were found to be independently associated with CRC, while elevated platelet count and younger age were independently associated with IBD. On ROC curve analysis for CRC, area under the curve (AUC) for hematocrit, platelets, and localized CWT was 0.76, 0.75, and 0.61, respectively. On ROC curve analysis for IBD, AUC for age and platelets was 0.90 and 0.69, respectively.

Conclusion

Elevated platelet count, low hematocrit, and localized CWT can be potentially used as predictors of CRC in patients with CWT. Elevated platelet count and young age can be used to predict IBD in these patients.
Effects of dopants in the imaging of mouse brain by desorption electrospray ionization/post‐photoionization mass spectrometry
Authors: Wu Liutian , Qi Keke , Xu Minggao , Liu Chengyuan , Pan Yang
Published: February 2022

Desorption electrospray ionization/post‐photoionization (DESI/PI) is a newly developed ionization method by the combination of DESI and post‐photoionization for the simultaneous imaging of polar and nonpolar compounds in biological tissues. Dopants are of great importance in DESI/PI for the enhancement of signal intensities through ion–molecule reactions. In this work, to evaluate the performance of dopants in DESI/PI, an efficient homogenate model was developed, and four kinds of dopants (toluene, chlorobenzene, bromobenzene, and anisole) were tested using homogenate of mouse brain tissue as target sample. The influences of the dopants on the signal enhancements of different compounds were explained reasonably by the ionization mechanism. Then, the dopants with their optimum volume contents were applied to the mass spectrometry imaging (MSI). For a comprehensive imaging of various compounds with different polarities, methanol/toluene/formic acid (7:3:0.1) was chosen as the best choice. Finally, the stronger quantitative ability of DESI/PI with toluene as dopant for a few compounds in mouse brain tissue was demonstrated.
Omicron (B.1.1.529) variant of SARS‐CoV‐2: Concerns, challenges, and recent updates
Authors: Mohapatra Ranjan K. , Tiwari Ruchi , Sarangi Ashish K. , Islam Md. Rabiul , Chakraborty Chiranjib , Dhama Kuldeep
Published: February 2022

Highlights

Omicron has shown immune escape from neutralizing antibodies generated through previous infection or vaccination.

It could evade the protection provided by mAbs being used in clinics for treating coronavirus disease 2019 (COVID‐19) patients.

Booster dose is recommended to elevate the protective levels of antibodies in COVID‐19 vaccinated individuals.

The development of powerful oral antiviral drugs such as Molnupiravir and Paxlovid have shown promising clinical results and raised new hopes of COVID‐19 treatment.

High efforts are being made to develop highly efficacious vaccines, and by implementing appropriate prevention and control strategies to counter Omicron.
Third dose of SARS‐CoV‐2 vaccine: A systematic review of 30 published studies
Authors: Petrelli Fausto , Luciani Andrea , Borgonovo Karen , Ghilardi Mara , Parati Maria Chiara , Petrò Daniela , Lonati Veronica , Pesenti Angelo , Cabiddu Mary
Published: February 2022

We analyzed published studies on the efficacy and safety of the third dose of the COVID‐19 vaccine in various general population settings. We conducted systematic searches of PubMed and EMBASE for series published in the English language through November 15, 2021, using the search terms “third” or “booster” or “three” and “dose” and “COVID‐19” or “SARS‐CoV‐2.” All articles were selected according to the MOOSE guidelines. The seroconversion risk after third doses was descriptively expressed as a pooled rate ratio ([seroconversion rate after the third dose]/[seroconversion rate after the second dose]). The search returned 30 studies that included a total of 2 734 437 vaccinated subjects. In more than 2 700 000 Israeli patients extracted from the general population, the reduction in the risk of infection ranged from 88% to 92%. Conversion rates for IgG anti‐spike ranged from 95% to 100%. In cancer or immunocompromised patients, mean IgG seroconversion was 39.4% before and 66.6% after third doses. A third dose seems necessary to protect against all COVID‐19 infection, severe disease, and death risk.
Production of surface‐active sophorolipid biosurfactant and crude oil degradability by novel Rhodotorula mucilaginosa strain SKF2
Authors: Kazemzadeh Somayeh , Emami‐Karvani Zarrindokht , Naghavi Nafiseh Sadat , Emtiazi Giti
Published: February 2022

Biosurfactants are produced by important types of microorganisms such as bacteria, yeast, and filamentous fungi and have been used in a variety of industries. Among the 15 crude oil‐degrading fungi, the two molds and one yeast were identified by 18S rDNA sequences as Mucor circinelloides strain SKMC, Fusarium fujikuroi strain DB2, and Rhodotorula mucilaginosa strain SKF2. These strains were isolated from crude oil–contaminated soil, diesel oil–contaminated soil, and activated sludge in the Oil Refinery Plant in Isfahan, Iran, respectively. The yeast strain was identified as a novel crude oil–degrading and biosurfactant‐producing fungi in the presence of (1% v/v) Iranian light crude oil in the minimal salt medium (MSM). The highest amount of the dry weight of produced biosurfactant was measured at 6.2 g L−1. Chemical nature of produced biosurfactant was determined as a surface‐active sophorolipid biosurfactant compound by thin‐layer chromatography, Fourier transform infra‐red spectroscopy, and gas chromatography–mass spectrometry (GC–MS) analysis. The residual hydrocarbons in the MSM were analyzed by GC–MS, and it was shown that octadecane and docosane were eliminated by this novel strain completely.
Deep convolutional neural network‐based quantitative evaluation of display non‐uniformity
Authors: Kidoguchi Satomi , Bamba Yusuke
Published: February 2022

We developed a quantitative method for evaluation of display luminance and color non‐uniformity (which we call mura) using a deep convolutional neural network (DCNN). In previous research, quantitative evaluation methods using DCNN were studied. From among a wide variety of DCNN models, these methods have used a convolutional autoencoder (CAE) for abnormality detection. A CAE trained with only non‐defective data was then used to evaluate the degree of mura. However, there is a problem with these methods in that they have not been able to evaluate properly when there are multiple mura defects on a single screen. Consequently, the correlation between these methods and human visual evaluation was low. Therefore, we improved the previous method to handle multiple mura defects on the same screen. We confirmed the accuracy of the proposed method by comparing the quantitative evaluation and human visual evaluation. As a result, we obtained a higher correlation than the previous methods.
Thermal and Electrical Properties of Epoxy Composites Filled with 3D h‐BN/TOCNF Fillers
Authors: Chi Qingguo , Wu Jiaxue , Tang Chao , Zhang Changhai , Li Hua , Zhang Yongquan , Feng Yu , Zhang Tiandong
Published: February 2022

Epoxy resin (EP) has been widely used in electronic packaging and electrical equipment due to its excellent electrical insulating properties. However, the low thermal conductivity (TC) of EP limits its wider application and needs to be further improved. In this study, 3D hexagonal boron nitride (3D h‐BN) is successfully synthesized by utilizing TEMPO oxidated cellulose nanofiber hydrogels (TOCNF) as an interlocking skeleton, and then 3D h‐BN/TOCNF are chosen as the functional fillers to improve the TC of EP. The microstructure, TC, and electrical insulating properties of epoxy composites are systematically characterized and analyzed. The results show that epoxy composites filled with 3D h‐BN/TOCNF deliver a significantly improved TC and maintain excellent insulating properties. When the filled content of 3D h‐BN/TOCNF is 9 wt.%/21wt.%, a TC of 0.86 W (m K)−1 is obtained at 25 °C, which also demonstrates favorable electrical insulating properties with a volume resistivity of more than 1015 Ω m and breakdown strength of 186.1 kV mm−1. This work offers an efficient method to improve the thermal and electrical performances of EP for electronics and electrical engineering applications.
Two‐dimensional collocation method for generalized partial integro‐differential equations of fractional order with applications
Authors: Sharma Shiva , Kumar Sandeep , Pandey Rajesh K. , Kumar Kamlesh
Published: February 2022

In this paper, we present a new generalized model of partial integro‐differential equation of fractional order (PIDEFO). The new model of the PIDEFO is defined in terms of the
operator presented recently. The
operator takes form of the Riemann‐Liouville and Caputo derivatives in special case. The generalized model of the PIDEFO reduces to (1) linear space‐time fractional reaction‐diffusion equation (FRDE), (2) space‐time fractional diffusion equations (STFDE), and (3) time fractional telegraph equations (TFTE) in particular cases. The considered model is solved with collocation method using Jacobi polynomials. For theoretical accuracy, we prove that the Jacobi approximation converges to the exact solution uniformly. Two test examples are considered to verify the accuracy of the proposed method. Further, we present two applications of the proposed model and solve it using the presented method. The obtained numerical results are compared with the existing results. Finally, the numerical stability of the presented method is analyzed under the effect of the random noise in the force term.
Transcriptional dynamics of the circulating chicken primordial germ cells revealing key genes in cell adhesion and proliferation prior to gonad colonization
Authors: Huang Xiaochen , Meng Lu , Wang Sheng , Man Qiu , Jiang Yunqi , Zhu Guiyu
Published: February 2022

Primordial germ cells (PGCs), precursors to sperms and oocytes, are responsible for the transfer of genetic information to the next generation. The PGCs arise far away from the developing gonad and thus have to migrate across the embryo to reach their site of function. The migration of PGCs from extraembryonic regions to the genital ridges is accomplished through distinct routes among different species. In particular, the birds PGCs utilized the developing circulation system to travel long distance before settling within the gonad. This study screened the transcriptome profile of chicken PGCs isolated from the bloodstream and the genital ridges to identify the cell intrinsic signals that could guide the unique migration path through circulation. We found cell adhesion and extracellular matrix (ECM) associated pathways were highly enriched in the PGCs from blood but not gonads. The platelet‐derived growth factor receptors (PDGFRA and PDGFRB) were downregulated during gonad colonization and knockdown of either PDGFRA or PDGFRB inhibit the proliferation of blood PGCs. Furthermore, the migration of blood PGCs was impaired by the suppression of PDGFRA but not PDGFRB. Hence, the chicken PGCs show dynamic transcriptional remodeling during the blood‐to‐gonad migration and colonization. The free‐floating PGCs in the circulation already express genes associated with cell–cell and cell‐ECM interactions and therefore prepare for gonadal colonization.
Peripheral nerve morphology and intraneural blood flow in chronic kidney disease with and without diabetes
Authors: Issar Tushar , Walker Susan , Arnold Ria , Poynten Ann M. , Endre Zoltan H. , Krishnan Arun V.
Published: February 2022

Introduction/Aims

Sonographic alterations of peripheral nerves in pre‐dialytic kidney disease are yet to be determined. We aimed to assess peripheral nerve cross‐sectional area (CSA) and intraneural blood flow in patients with pre‐dialytic chronic kidney disease (CKD) and diabetic kidney disease (DKD).

Methods

Subjects with CKD (n = 20) or DKD (n = 20) underwent ultrasound to assess CSA of the median and tibial nerves as well as intraneural blood flow of the median nerve. Blood flow was quantified using maximum perfusion intensity. Neuropathy was assessed using the Total Neuropathy Score. A 6‐m timed walk test was also performed. Healthy controls (n = 28) were recruited for comparison.

Results

The DKD group had more severe neuropathy (p = .024), larger tibial nerve CSA (p = .002) and greater median nerve blood flow than the CKD group (p = .023). Blood flow correlated with serum potassium in disease groups (r = 0.652, p = .022). Disease groups had larger tibial nerve CSA than controls (p < .05). No blood flow was detected in controls. Tibial nerve enlargement was associated with slower maximal walking speeds in disease groups (r = −0.389, p = .021).

Discussion

Subjects with DKD demonstrated enlarged tibial nerve CSA and increased median nerve blood flow compared to those with CKD. Elevations in serum potassium were associated with increased blood flow. Sonographic alterations were detectable in pre‐dialytic kidney disease compared to controls, highlighting the utility of ultrasound in the assessment of nerve pathology in these patient groups.
Assessment of the relationship between disease progression and goals of care by individuals with Duchenne muscular dystrophy and their caregivers
Authors: Grossoehme Daniel H. , Thienprayoon Rachel , Sawnani Hemant , Jenkins Rachel , Rossman Ian , Mosher Kathryn , Friebert Sarah
Published: February 2022

Introduction/Aims

Most patients with Duchenne muscular dystrophy (DMD) in the US are diagnosed at about age 5 years. Some adolescents and young adults (AYAs) with DMD are now living into their fourth decade, yet AYAs and caregivers are frequently unprepared to address changes in goals of care due to disease progression. The hypothesis‐generating research question was how AYAs with DMD and their caregivers understand the relationship between physical changes and the need to change goals of care.

Methods

Grounded theory design using data from N = 30 semi‐structured interviews (n = 13 AYA; n = 17 caregivers) from two sites.

Results

AYAs with DMD frequently defer considering and/or reconsidering goals of care based on (1) delays in diagnosis; (2) gradual, rather than episodic, disease progression; and (3) orientation to living in the present. Desire for autonomy motivates advance care planning and end‐of‐life treatment preferences for some.

Discussion

Routine inquiry into AYA and caregiver goals for living may normalize goals of care conversations, maximizing patients' ability to process information, reflect on preferences, and articulate wishes. Discussing present‐day goals and abilities may invite conversation about future preferences. Framing conversations in terms of AYA autonomy may increase motivation to engage in such discussions.
The effect of customer awareness on priority queues
Authors: Wang Zhongbin , Fang Lei
Published: February 2022

Pay‐for‐priority system is believed to be an efficient service mechanism in congested systems since it introduces service differentiation that prioritizes those who are more delay‐sensitive. However, in practice, not all customers are aware of the provision of such auxiliary service (i.e., priority access). Does the lack of awareness or ignorance of priority service make the social welfare or customer surplus worsen off? To answer this question, we establish a queueing‐game‐theoretic model by capturing the strategic interactions between service provider and customers to examine the effect of customer awareness on the priority queues. Our main results are as follows. First, we confirm that increasing the level of customer awareness indeed improves the revenue of service provider, and it triggers a higher priority premium price. Second, perhaps surprisingly, we find that under the profit‐maximizing priority price, the social welfare as well as the customer surplus are both nonmonotone in the level of customer awareness, that is, full or no customer awareness can be suboptimal for the social welfare and customer surplus. Third, despite the common belief that priority is socially efficient in congested systems, we demonstrate that the optimal information levels for social welfare and customer surplus are decreasing in the congestion level, and the full customer awareness is optimal only when the system load is relatively low. Finally, to reach the maximal social welfare or customer surplus, some regulation policies are proposed, whereby the social planner can provide advertising subsidy to (levy tax on) the service provider (advertising agency) when the system load is low (high).
A novel method for solving nonlinear stochastic mechanics problems using FETI‐DP
Authors: Ajith Gopika , Ghosh Debraj
Published: February 2022

Solution of large‐scale nonlinear stochastic mechanics problems such as plasticity is generally very expensive. In this work, a domain decomposition based scalable method is proposed for solving such problems. The mechanics problem and random fields are discretized using finite element (FE) bases and Karhunen–Loève expansion, respectively. The FE mesh is partitioned that offers (i) both spatial and stochastic dimensionality reduction and (ii) an inherent framework for parallelization. Then a stochastic collocation based surrogate model is built for each subdomain wherein at each collocation point a deterministic nonlinear problem is solved. The deterministic nonlinear problem is solved using Newton–Raphson method. The linear system of equations involving the Jacobian is solved using the dual‐primal version of the FE tearing and interconnecting (FETI‐DP) method, due to its demonstrated scalability for deterministic problems. Stochastic collocation and FETI‐DP are inherently and independently parallelizable. Finally, at the post‐processing stage, a statistical sampling from the surrogate model is performed by preserving the structure of the input random field. The proposed method is numerically tested for p‐Laplace and plain‐strain plasticity problems, and found to be computationally efficient and accurate. In parallel implementation, the method showed good scalability.
A semi‐relativistic time‐fractional Vlasov–Maxwell code for numerical simulation based on circular polarization and Landau damping instability
Authors: Zubair Tamour , Usman Muhammad
Published: February 2022

The Vlasov–Maxwell system is a revolutionary tool to model and analyze the dynamic behavior of the collisionless plasma in the existence of the electromagnetic field. In this perspective, the investigation of this system with the concept of the time‐fractional derivative is the new benchmark and also one of the main objectives of this article. In order to construct the numerical solution, we propose and implement a novel scheme which grounded on finite‐difference and spectral approximations. The temporal variable is tackled by using finite‐difference approximation, whereas spatial variables approximated via sifted Gegenbauer polynomials. Various simulations are performed to explore new phenomena and demonstrate the accuracy and reliability of the proposed method. Convergence and error bound of the suggested methods are investigated theoretically, whereas stability analysis performed numerically. Moreover, the developed method can be used conveniently to examine the numerical solution of other multidimensional highly nonlinear fractional or variable order problems of physical nature.
Construction of 2D/2D graphene oxide/g‐C3N4 hybrid for enhancing the friction and wear performance of poly (phthalazinone ether sulfone ketone)
Authors: Wang Fenghua , Zhang Mengjie , Li Jiaye , Dong Zhe , Xu Lin , Wang Shuang , Zhang Kan , Chen Beibei
Published: February 2022

In this study, a novel hybrid consisted of two‐dimensional graphene oxide (GO) and graphitic carbon nitride (g‐C3N4) nanosheets were fabricated to improve the tribological performance of poly (phthalazinone ether sulfone ketone) (PPESK). The effect of the mass ratio of GO to g‐C3N4 (1:1, 1:2, and 1:3) on the microstructure of GO/g‐C3N4 was firstly studied. As the ratio was 1:2 (GO/g‐C3N4‐2), the g‐C3N4 could be homogeneously distributed on surface of GO, and the corresponding hybrid possessed many active sites. Moreover, the effect of GO/g‐C3N4 hybrid, GO, and g‐C3N4 on the tribological properties of PPESK matrix was explored systematically. Results showed that GO/g‐C3N4 demonstrated more excellent reinforcing and lubricating effect than single GO and g‐C3N4, especially for GO/g‐C3N4‐2. More importantly, as the content of GO/g‐C3N4‐2 was 0.1 wt%, the antifriction and anti‐wear performance of PPESK was improved by 77.28% and 96.9%, respectively. Moreover, the enhancement mechanisms of GO/g‐C3N4 on the tribological behaviors of PPESK were clarified by analyzing the surface morphology of the composite and the counterpart. This work might provide the guidance for the design of a novel nano‐hybrid material applied in polymer self‐lubricating composites.
Efficient polymerization and crystallization kinetics coupling of polyamide 6 synthesis for liquid composite molding process modeling
Authors: Han William , Govignon Quentin , Cantarel Arthur , Schmidt Fabrice
Published: February 2022

Variabilities in polyamide 6 (PA6) composite manufacturing by liquid processes can occur due to polymerization, crystallization, and flow through a fibrous preform. Numerical simulations of the process predicting the kinetics can facilitate manufacturing optimization. This study proposes an efficient modeling approach that can be integrated in current simulation discretization methods such as the finite volume method (FVM) while considering the interaction between PA6 polymerization and crystallization. Using polymerization and crystallization models issued from the literature, a previous study determined Hillier coupling method to be able to predict PA6 kinetics. A simpler and more efficient coupling will be introduced and adapted to account for process variability. It was integrated into an FVM framework for process simulation of injection showcasing the capabilities of the model to predict potential crystallization discrepancies.
The Significant Influence of the pH Value on Citrate Coordination upon Modification of Superparamagnetic Iron Oxide Nanoparticles
Authors: Granath Tim , Mandel Karl , Löbmann Peer
Published: February 2022

Although citrates are commonly used to modify nanoparticles, attention is rarely paid to how the modification parameters affect the type of adsorption and, thus, possibly, the properties of the modified particles. The relevance of this and the significant impact it can have is demonstrated in this study by examining the effect of pH upon the modification of superparamagnetic iron oxide nanoparticles (SPIONs) with citrate, using a citrate concentration that yields a high molecular surface density but induces almost no coordination pressure. Relying first on a number of classical surfaces analyzing methods, no clear pH‐dependent differences can be identified. Finally, the consideration of the thermally induced redox behavior gives a decisive clue to unravel the “citric acid mystery” and to put together the, until then, weak hints into an overall picture. This shows that the citrate carboxyl groups are linked to the oxidic surface pH dependently via hydrogen bonds to hydroxide groups or coordinatively to iron ions and, besides, also interact, to a certain extent, with ammonia that is used for pH adjustment. With these findings, it is finally possible to explain the observed differences when the citrate‐modified SPIONs are coated with silica (SiO2) or redispersed after spray‐drying.
Growth and Optical Properties of Lead‐Free Cs3Bi2Br9 Perovskite Microplatelets
Authors: Deng Fang , Zhang Jinlei , Wu Shuyi , Liu Cihui , Xing Fangjian , Xu Jiaqing , Di Yunsong , Yu Liyan , Dong Lifeng , Gan Zhixing
Published: February 2022

Lead‐free halide perovskites are drawing increasing interest due to their environmental friendliness, good thermal stabilities, and unique optoelectronic properties. Herein, a simple and rapid wet‐chemical approach is developed to synthesize the lead‐free Cs3Bi2Br9 microplatelets (MPs) with regular hexagonal shapes (side length of ≈5–12 μm). A strong photoluminescence (PL) emission located at 425 nm and a very weak PL band located at 576 nm are observed, which are ascribed to the intrinsic band‐edge transition and the emissive deep level defects, respectively. The weak emission at 576 nm implies the good crystalline quality of the as‐prepared Cs3Bi2Br9 MPs. Spatially resolved PL and Raman mappings exhibit inhomogeneous distributions. Both the PL emissions and Raman scatterings at the edges are remarkably stronger than those at the center, which are interpreted by the formation of whispering‐gallery modes (WGMs) due to the optical resonance of cavity, as supported by our finite‐difference time‐domain (FDTD) simulations. Therefore, the hexagonal Cs3Bi2Br9 MPs can act as optical cavities, which will play important roles in micro‐waveguides and micro‐lasers that are significant for the development of integrated photonic chips.
Fluorescent lymphography for thoracic duct identification: Initial experience of a simplified and feasible ICG administration
Authors: Barbato Giuseppe , Cammelli Francesca , Braccini Giovanni , Staderini Fabio , Cianchi Fabio , Coratti Francesco
Published: February 2022

Introduction

Indocyanine green (ICG) lymphography can be performed to obtain realtime fluorescent images of the thoracic duct (TD). The injection of ICG into the inguinal nodes usually is ultrasound‐guided. Our hypothesis was to simplify the ICG administration until making it executable by unqualified personnel without ultrasound guidance.

Material and methods

From October 2019 to October 2021 we enroled 18 patients. ICG was injected with a 25 Gauge needle in the subcutaneous tissue of the inguinal region bilaterally 14–16 h before surgery.

Results

The TD was visualised in every case considered. The easy switching between fluorescence and white light visualization facilitated the identification and dissection of the TD avoiding involuntary injuries.

Conclusions

The simplified ICG administration to identify TD during oesophagectomy is easy to perform, does not require specifically trained staff, is not time demanding and has comparable results to the procedure performed under ultrasound guide.
DNA methylation in blood cells is associated with cortisol levels in offspring of mothers who had prenatal post‐traumatic stress disorder
Authors: Fransquet Peter Daniel , Hjort Line , Rushiti Feride , Wang Shr‐Jie , Krasniqi Sebahate Pacolli , Çarkaxhiu Selvi Izeti , Arifaj Dafina , Xhemaili Vjosa Devaja , Salihu Mimoza , Leku Nazmie Abullahu , Ryan Joanne
Published: February 2022

Maternal stress during pregnancy is associated with differential DNA methylation in offspring and disrupted cortisol secretion. This study aimed to determine methylation signatures of cortisol levels in children, and whether associations differ based on maternal post‐traumatic stress disorder (PTSD). Blood epigenome‐wide methylation and fasting cortisol levels were measured in 118 offspring of mothers recruited from the Kosovo Rehabilitation Centre for Torture Victims. Mothers underwent clinically administered assessment for PTSD using Diagnostic and Statistical Manual of Mental Disorders. Correlations between offspring methylation and cortisol levels were examined using epigenome‐wide analysis, adjusting for covariates. Subsequent analysis focussed on a priori selected genes involved in the hypothalamic–pituitary–adrenal (HPA) axis stress signalling. Methylation at four sites were correlated with cortisol levels (cg15321696, r = −0.33, cg18105800, r = +0.33, cg00986889, r = −0.25, and cg15920527, r = −0.27). In adjusted multivariable regression, when stratifying based on prenatal PTSD status, significant associations were only found for children born to mothers with prenatal PTSD (p < 0.001). Several sites within HPA axis genes were also associated with cortisol levels in the maternal PTSD group specifically. There is evidence that methylation is associated with cortisol levels, particularly in offspring born to mothers with prenatal PTSD. However, larger studies need to be carried out to independently validate these findings.
Chemical Approaches to Carbocyclic Nucleosides
Authors: Ojeda‐Porras Andrea C. , Roy Vincent , Agrofoglio Luigi A.
Published: February 2022

Nucleoside analogues are at the forefront of antiviral therapy for last decades. To circumvent some of their limitations, based on their metabolism, and in order to improve their anti‐viral potency and selectivity, several families of nucleoside analogues have been described through structural modifications at the sugar and heterocycles. The replacement of the oxygen of the nucleoside by a methylene has led to the family of carbocyclic (or cyclopentane) nucleoside analogues. Various potent anti‐HIV and anti‐HBV drugs belong to this family. Main syntheses of carbocyclic analogues of nucleosides used Diels‐Alder reactions (in racemic or asymmetric series), but also started from carbohydrates (ribose, glucose), as a source of optically active compounds, which then had to be transformed into carbacycles under various conditions. The growing interest in carbocyclic nucleosides has led several groups, including ours, to develop new analogues and to explore novel routes. This article will review some of the recent chemistry developed on selected five‐membered ring carbocyclic nucleosides.
Synthesis of Nucleobase‐Modified Oligonucleotides by Post‐Synthetic Modification in Solution
Authors: Ito Yuta , Hari Yoshiyuki
Published: February 2022

Oligonucleotides containing modified nucleobases have applications in various technologies. In general, to synthesize oligonucleotides with different nucleobase structures, each modified phosphoramidite monomer needs to be prepared over multiple steps and then introduced onto the oligonucleotides, which is time‐consuming and inefficient. Post‐synthetic modification is a powerful strategy for preparing many types of modified oligonucleotides, especially nucleobase‐modified ones. Depending on the stage of modification, post‐synthetic modification can be divided into two stages: “solid‐phase modification,” wherein an oligonucleotide attaches to the resin, and “solution‐phase modification,” wherein an oligonucleotide detaches itself from the resin. In this review, we focus on post‐synthetic modification in solution for the synthesis of nucleobase‐modified oligonucleotides, except the modifications to linkers for conjugation. Moreover, the reactions are summarized for each modified position of the nucleobases.
Metal‐Organic Frameworks Derived Electrocatalysts for Oxygen and Carbon Dioxide Reduction Reaction
Authors: Najam Tayyaba , Ahmad Khan Naseem , Ahmad Shah Syed Shoaib , Ahmad Khalil , Sufyan Javed Muhammad , Suleman Suleman , Sohail Bashir Muhammad , Hasnat Mohammad A. , Rahman Mohammed M.
Published: February 2022

The increasing demands of energy and environmental concerns have motivated researchers to cultivate renewable energy resources for replacing conventional fossil fuels. The modern energy conversion and storage devices required high efficient and stable electrocatalysts to fulfil the market demands. In previous years, we are witness for considerable developments of scientific attention in Metal‐organic Frameworks (MOFs) and their derived nanomaterials in electrocatalysis. In current review article, we have discussed the progress of optimistic strategies and approaches for the manufacturing of MOF‐derived functional materials and their presentation as electrocatalysts for significant energy related reactions. MOFs functioning as a self‐sacrificing template bid different benefits for the preparation of metal nanostructures, metal oxides and carbon‐abundant materials promoting through the porous structure, organic functionalities, abundance of metal sites and large surface area. Thorough study for the recent advancement in the MOF‐derived materials, metal‐coordinated N‐doped carbons with single‐atom active sites are emerging candidates for future commercial applications. However, there are some tasks that should be addressed, to attain improved, appreciative and controlled structural parameters for catalytic and chemical behavior.
Cytopathological and bacteriological studies on caseous lymphadenitis in cattle slaughtered at Bishoftu municipal abattoir, Ethiopia
Authors: Mathewos Mesfin , Fesseha Haben
Published: February 2022

Background

Caseous lymphadenitis (CLA) is a chronic bacterial infectious disease that affects cattle, shoats, and other domestic and wild ruminants.

Methods

A purposive cross‐sectional study was conducted on 30 cattle with enlarged lymph nodes to investigate CLA using cytopathological and bacteriological techniques from cattle slaughtered at Bishoftu municipal abattoir.

Results

From a total of 30 cattle subjected to clinical and post‐mortem examinations, only one bull was found to be infected with a rare case of CLA in Bishoftu municipal abattoir, Ethiopia. Enlargement of the pre‐scapular lymph node was the only clinical finding during ante‐mortem inspection of the bull. The gross pathological lesion showed a pre‐scapular lymph node with a caseo‐necrotic dystrophic calcification that was accompanied by a rough texture and white to grayish hue. Histopathologically, the lymph node was characterized by central liquefactive necrosis that was surrounded by coagulative necrosis containing multiple foci of mineralization, infiltration of polymorphonuclear neutrophils and mononuclear immature fibrosis containing inflammatory cells and also with some sort of a thick layer of mature fibrosis that defines the magnitude of the lesion. Cytologically, multi‐lobulated (intact and degenerated) neutrophils, a few reactive lymphocytes, macrophages and some crenated histocytes have been recognized. The bacterial culture of the sample revealed small, white cream, dry, waxy colonies with a narrow area of β‐haemolysis. The isolate of the sample was a Gram‐positive cocci‐bacilli that was arranged in a Chinese pattern on Gram staining, and catalase and urease were positive in the biochemical analysis of this organism, which was able to ferment glucose and maltose but not trehalose and xylose.

Conclusions

The present investigation indicated that CLA was prevalent as sporadic cases among cattle slaughtered in Bishoftu municipal abattoir. Thus, effective preventive and control measures, such as good sanitation and hygiene, should be followed during meat inspection.
Natural carbon removal as technology
Authors: Markusson Nils
Published: February 2022

Lay people tend to prefer natural solutions for carbon removal over technological ones. Researchers have argued that all carbon removal methods can be seen as “natural.” Here I argue that it is also in practice necessary to see all carbon removal methods as “technological,” that is, standardized, engineered, machine‐like, enclosed systems. Natural carbon removal methods are complex socio‐natural‐technical messy systems that interact in complex ways with their environments. But to work well in practice as an option in climate policy—including in any emissions trading or offsetting schemes—they simultaneously need to be framed in much narrower terms, to be accountable (modellable, tradeable). And there will be efforts to not just frame, but physically make natural carbon removal as standardized, engineered, machine‐like and enclosed as possible—although doomed to never be fully successful. It is in these senses that all carbon removal is technological. The ambiguity between an often vague framing as natural, a narrowly technological framing, and a wider socio‐natural‐technical framing, matters for public understanding and acceptance. Would lay publics still prefer natural solutions to carbon removal, if they are informed about the inevitable technological framing and shaping of them? Research is needed about this. It also matters for the risk of mitigation deterrence. Previous research shows that the narrow framing, of carbon removal methods as technology is implicated in societal processes that deter efforts to reduce greenhouse gas emissions.

This article is categorized under:

Social Status of Climate Change Knowledge > Knowledge and Practice

Social Status of Climate Change Knowledge > Sociology/Anthropology of Climate Knowledge

Climate, History, Society, Culture > Technological Aspects and Ideas
Calabi-Yau CFTs and random matrices
Authors: Afkhami-Jeddi Nima , Ashmore Anthony , Córdova Clay
Published: February 2022

Abstract

Using numerical methods for finding Ricci-flat metrics, we explore the spectrum of local operators in two-dimensional conformal field theories defined by sigma models on Calabi-Yau targets at large volume. Focusing on the examples of K3 and the quintic, we show that the spectrum, averaged over a region in complex structure moduli space, possesses the same statistical properties as the Gaussian orthogonal ensemble of random matrix theory.
Supertranslations at timelike infinity
Authors: Chakraborty Sumanta , Ghosh Debodirna , Hoque Sk Jahanur , Khairnar Aniket , Virmani Amitabh
Published: February 2022

Abstract

We propose a definition of asymptotic flatness at timelike infinity in four spacetime dimensions. We present a detailed study of the asymptotic equations of motion and the action of supertranslations on asymptotic fields. We show that the Lee-Wald symplectic form Ω(g, δ1g, δ2g) does not get contributions from future timelike infinity with our boundary conditions. As a result, the “future charges” can be computed on any two-dimensional surface surrounding the sources at timelike infinity. We present expressions for supertranslation and Lorentz charges.
A note on imputing squares via polynomial combination approach
Authors: Cai Mingyang , Vink Gerko
Published: February 2022

The polynomial combination (PC) method, proposed by Vink and Van Buuren, is a hot-deck multiple imputation method for imputation models containing squared terms. The method yields unbiased regression estimates and preserves the quadratic relationships in the imputed data for both MCAR and MAR mechanisms. However, Vink and Van Buuren never studied the coverage rate of the PC method. This paper investigates the coverage of the nominal 95% confidence intervals for the polynomial combination method and improves the algorithm to avoid the perfect prediction issue. We also compare the original and the improved PC method to the substantive model compatible fully conditional specification method proposed by Bartlett et al. and elucidate the two imputation methods’ characters.