bluuebunny/crossref_metadata_2025 huggingface dataset:
Nationwide increases in anti-SARS-CoV-2 IgG antibodies between October 2020 and March 2021 in the unvaccinated Czech population
Authors: Piler Pavel , Thon Vojtěch , Andrýsková Lenka , Doležel Kamil , Kostka David , Pavlík Tomáš , Dušek Ladislav , Pikhart Hynek , Bobák Martin , Matic Srdan , Klánová Jana
Published: March 2022

Background

The aim of the nationwide prospective seroconversion (PROSECO) study was to investigate the dynamics of anti-SARS-CoV-2 IgG antibodies in the Czech population. Here we report on baseline prevalence from that study.

Methods

The study included the first 30,054 persons who provided a blood sample between October 2020 and March 2021. Seroprevalence was compared between calendar periods, previous RT-PCR results and other factors.

Results

The data show a large increase in seropositivity over time, from 28% in October/November 2020 to 43% in December 2020/January 2021 to 51% in February/March 2021. These trends were consistent with government data on cumulative viral antigenic prevalence in the population captured by PCR testing – although the seroprevalence rates established in this study were considerably higher. There were only minor differences in seropositivity between sexes, age groups and BMI categories, and results were similar between test providing laboratories. Seropositivity was substantially higher among persons with history of symptoms (76% vs. 34%). At least one third of all seropositive participants had no history of symptoms, and 28% of participants with antibodies against SARS-CoV-2 never underwent PCR testing.

Conclusions

Our data confirm the rapidly increasing prevalence in the Czech population during the rising pandemic wave prior to the beginning of vaccination. The difference between our results on seroprevalence and PCR testing suggests that antibody response provides a better marker of past infection than the routine testing program.
Microstructural modifications induced in Si+-implanted yttria-stabilised zirconia: a combined RBS-C, XRD and Raman investigation
Authors: Mikšová Romana , Malinský Petr , Cutroneo Mariapompea , Holý Václav , Sofer Zdeněk , Cajzl Jakub , Debelle Aurélien , Nowicki Lech , Macková Anna
Published: March 2022

The structural differences in (100)-, (110)- and (111)-oriented cubic yttria-stabilised zirconia (YSZ) single crystals after implantation with 2 MeV Si+ ions at the fluences of 5 × 1015, 1 × 1016 and 5 × 1016 cm−2 were studied using Rutherford backscattering spectrometry in the channelling mode (RBS-C), using X-ray diffraction (XRD) and Raman spectroscopy.
Photophysical properties and optical nonlinearity of cyclo[18]carbon (C18) precursors, C18–(CO)n(n= 2, 4, and 6): focusing on the effect of the carbonyl groups
Authors: Wang Xia , Liu Zeyu , Yan Xiufen , Lu Tian , Wang Haowei , Xiong Weiwei , Zhao Mengdi
Published: March 2022

The electronic spectra and (hyper)polarizability of C18–(CO)n(n= 2, 4, and 6) are studied using theoretical calculations to reveal the effect of introducing carbonyl groups on the molecular optical properties.
Electronic control over site-selectivity in hydrogen atom transfer (HAT) based C(sp3)–H functionalization promoted by electrophilic reagents
Authors: Galeotti Marco , Salamone Michela , Bietti Massimo
Published: March 2022

Leveraging on electronic effects in both the substrate and HAT reagent, site-selectivity can be implemented in C(sp3)–H bond functionalization.
Roughening the surface of porous NiCoP rod-like arrays via the in situ growth of NiCoP4O12 nanoislands enables highly efficient energy storage
Authors: Cui Mengqi , Jiang Yuanye , Wang Zhihao , Wang Xuyun , Wang Hui , Wang Rongfang
Published: March 2022

Hollow NiCoP nanowire arrays were prepared by vapor deposition method, and then rough NiCoP4O12 nanoparticles were prepared by heat treatment, which exhibited excellent specific capacitance and high energy density and power density.
A simple and soft chemical deaggregation method producing single-digit detonation nanodiamonds
Authors: Terada Daiki , So Frederick Tze Kit , Hattendorf Bodo , Yanagi Tamami , Ōsawa Eiji , Mizuochi Norikazu , Shirakawa Masahiro , Igarashi Ryuji , Segawa Takuya Fabian
Published: March 2022

Detonation nanodiamonds (DNDs) are a class of very small and spherical diamond nanocrystals. Only after deaggregation they fully unfold their versatile potential from polymer reinforcement materials to drug delivery systems.
Engineering of the structural and morphological characteristics of MWCNTs employing a nano-dimensional binary oxide coating with enhanced thermal oxidation resistance properties for the tailoring of their reinforcement potential
Authors: Das Paromita , Sharma Savan Kumar , Sanfui Barun K.
Published: March 2022

The present investigation mainly addresses the rational design of a MgAl-binary-oxide-coated MWCNT nano-hybrid architecture and the study of its reinforcement potential.
A self-powered wearable brain–machine-interface system for ceasing action
Authors: Xiang Wang , Xie Yan , Han Yechao , Long Zhihe , Zhang Wanglinhan , Zhong Tianyan , Liang Shan , Xing Lili , Xue Xinyu , Zhan Yang
Published: March 2022

A self-powered wearable brain–machine-interface system for ceasing action has been realized based on a piezoelectric effect.
Semiconductor-to-metal transition from monolayer to bilayer blue phosphorous induced by extremely strong interlayer coupling: a first-principles study
Authors: Wang Dan-Dong , Gong Xin-Gao , Yang Ji-Hui
Published: March 2022

Monolayer blue phosphorous has a large band gap of 2.76 eV but counterintuitively the most stable bilayer blue phosphorous has a negative band gap of −0.51 eV.
Low-cost Y-type zeolite/carbon porous composite from coal gasification fine slag and its application in the phenol removal from wastewater: fabrication, characterization, equilibrium, and kinetic studies
Authors: Chai Zhen , Lv Peng , Bai Yonghui , Wang Jiaofei , Song Xudong , Su Weiguang , Yu Guangsuo
Published: March 2022

A method is presented for preparing a Y-type zeolite/carbon composite with coal gasification fine slag for removing phenol in wastewater.
Highly efficient separation and enrichment of polyphenols by 6-aminopyridine-3-boronic acid-functionalized magnetic nanoparticles assisted by polyethylenimine
Authors: Zhang Yansong , Qing Lianglei , Xu Linna
Published: March 2022

Synthesis routes of 6-aminopyridine-3-boronic acid-functionalized magnetic nanoparticles assisted by polyethylenimine (Fe3O4@PEI@PYBA).
A holistic framework for developing purposeful practical work
Authors: Hennah Naomi , Newton Sophie , Seery Michael K.
Published: March 2022

This work applies a cultural historical activity theory (CHAT) framework to understand how the outcome of a high school laboratory task may be positively influenced without making changes to the hands-on practical task itself. Informed by cognitivism, novel practical instruction videos that were based on the same video but had different audio content (“one video two voice overs”) have been developed to provide opportunities to prepare for the practical task procedure and then to reflect upon the task's underlying concepts. We use the CHAT framework as a guide to change pupils’ lab roles and rules of engagement were made to structure student interaction and facilitate an equitable and cooperative learning environment. We demonstrate that students benefit from these interventions and achieve significantly higher attainment scores in GCSE chemistry examination practical-themed questions than those students who prepared for the practical task by watching either the novel videos or standard instructional videos during the lesson. In, addition the students working in the scaffolded cooperative learning environment also perceived their confidence in relation to practical-related tasks at higher levels than those in other groups. This work contributes a novel approach to laboratory teaching by placing greater emphasis on dialogic processes as a tool accomplish a practical-based activity.
Enzyme-responsive strategy as a prospective cue to construct intelligent biomaterials for disease diagnosis and therapy
Authors: Wang Meiyu , Gao Bin , Wang Xiaoyu , Li Wenzhong , Feng Yakai
Published: February 2022

Enzyme-responsive materials and their applications in disease diagnosis and therapy.
N-Donor flexible ligands for constructing polyoxometalate-based metal–organic frameworks as multifunctional electrocatalysts
Authors: Zhou Qian , Yao Jin-Zhen , Sun Jing , Li Xiao , Bao Si-qi , Su Zhong-min
Published: March 2022

Two POMOFs,CUST-631andCUST-632, were synthesized by a hydrothermal method and then were directly prepared as electrode materials to explore the electrocatalytic properties for reduction of BrO3−and NO2−ions and oxidation properties towards AA.
Bypassing the bottlenecks in the shikimate and methylerythritol phosphate pathways for enhancing the production of natural products from methane in Methylotuvimicrobium alcaliphilum 20Z
Authors: Pham Diep Ngoc , Nguyen Anh Duc , Oh So Hyeon , Lee Eun Yeol
Published: March 2022

A methanotroph-based production of natural compounds (indigo and α-farnesene) coupled with metabolic engineering strategies for unraveling bottlenecks in their biosynthesis pathways has been developed.
A near-infrared intelligent molecular rotor with aggregation induced-emission for viscosity detection of liquids
Authors: Xu Lingfeng , Huang Yanrong , Peng Xinkang , Wu Kui , Huang Chunfang , Liu Limin
Published: March 2022

A near-infrared AIE-based intelligent molecular rotor was designed for viscosity detection during the beverage spoilage process.
Arrangements of fluorophores in the salts of imidazole tethered anthracene derivatives with pyridinedicarboxylic acids influencing photoluminescence
Authors: Singh Abhay Pratap , Baruah Jubaraj B.
Published: March 2022

Self-assemblies of salts of 9-N-(3-imidazolylpropylamino)methylanthracene with pyridinedicarboxylic acids, ionic-cocrystals with 1,3-dihydroxybenzene and their aggregation induced emissions in the solid state were studied.
Co2P decorated Co3O4 nanocomposites supported on carbon cloth with enhanced electrochemical performance for asymmetric supercapacitors
Authors: Zhang Qian , Zhu Jie , Yang Sudong , Chen Lin , Sun Maosong , Yang Xulin , Wang Pan , Li Kui , Zhao Peng
Published: March 2022

An effective strategy is demonstrated to promote electrochemical performance by the combination of Co3O4 with Co2P to form a composite electrode.
Blue-red emitting materials based on a pyrido[2,3-b]pyrazine backbone: design and tuning of the photophysical, aggregation-induced emission, electrochemical and theoretical properties
Authors: Kapse Deepak M. , Singh Pooja S. , Ghadiyali Mohammed , Chacko Sajeev , Kamble Rajesh M.
Published: March 2022

Tuning of opto-electrochemical and theoretical properties of D–A–D-based pyrido[2,3-b]pyrazine amine derivatives by modulating donor groups.
Freshness monitoring of raw fish by detecting biogenic amines using a gold nanoparticle-based colorimetric sensor array
Authors: Du Linlin , Lao Yijia , Sasaki Yui , Lyu Xiaojun , Gao Peng , Wu Si , Minami Tsuyoshi , Liu Yuanli
Published: March 2022

A gold nanoparticle-based chemosensor array functionalized with carboxylate derivatives performed freshness monitoring of amines in a fish sample.
Mining anion–aromatic interactions in the Protein Data Bank
Authors: Kuzniak-Glanowska Emilia , Glanowski Michał , Kurczab Rafał , Bojarski Andrzej J. , Podgajny Robert
Published: March 2022

The comprehensive analysis of non-redundant PDB macromolecular structures investigating anion distributions around all aromatic molecules in available biosystems is presented.
Defect and interface engineering in metal sulfide catalysts for the electrocatalytic nitrogen reduction reaction: a review
Authors: Chen Siru , Liu Xuan , Xiong Jiabin , Mi Liwei , Song Xue-Zhi , Li Yanqiang
Published: March 2022

The recent progress on metal sulfides toward the nitrogen reduction reaction (NRR) is summarized based on defect and interface engineering.
Can Dynamic Assessment Identify Language Disorder in Multilingual Children? Clinical Applications From a Systematic Review
Authors: Hunt Emily , Nang Charn , Meldrum Suzanne , Armstrong Elizabeth
Published: March 2022

Purpose:

Multilingual children are disproportionately represented on speech pathology caseloads, in part due to the limited ability of traditional language assessments to accurately capture multilingual children's language abilities. This systematic review evaluates the evidence for identification of language disorder in multilingual children using dynamic assessment and considers clinical applications of the evidence.

Method:

A systematic search of the Cumulative Index to Nursing and Allied Health Literature, Education Resources Information Centre, Education Source, Google Scholar, Linguistics, Medline, and PsycINFO databases produced 10 articles that met the inclusion criteria: between-groups comparison studies that used dynamic assessment to identify language disorder in children under 12 years old that spoke a different language at home to the majority society language. Articles were critically appraised using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) protocol.

Results:

Nine of the 10 studies reported that their dynamic assessment identified language disorder in multilingual children. However, small sample sizes, limited language pairs, variability in the reference standard, and design deficiencies resulted in poor ratings for all studies on QUADAS-2.

Conclusions:

The studies in this review reflected an emergent area of research. Preliminary guidelines for clinical application indicate that dynamic assessment may be a suitable and time-efficient complementary method of diagnosis of language disorder in multilingual children. Further recommendations about age of use, language of instruction, and relevant scores are included.
A comprehensive review on the users’ identity privacy for 5G networks
Authors: Saeed Mamoon M. , Hasan Mohammad Kamrul , Obaid Ahmed J. , Saeed Rashid A. , Mokhtar Rania A. , Ali Elmustafa Sayed , Akhtaruzzaman Md , Amanlou Sanaz , Hossain A. K. M. Zakir
Published: March 2022

Fifth Generation (5G) is the final generation in mobile communications, with minimum latency, high data throughput, and extra coverage. The 5G network must guarantee very good security and privacy levels for all users for these features. Therefore, researchers have deliberated the privacy and security solution of 5G users. The 5G wireless network offers a futuristic concept that helps to solve challenges affecting previous communications generations. The key concern to many scholars in the field of mobile networking is user privacy, which is long‐term subscription identifier as International Mobiles Subscribers Identifiers (IMSIs) and short‐term subscription identifier as Temporary Mobiles Subscribers Identifiers and Cell‐Radio Networks Temporary Identifiers (TMSIs and C‐RNTIs), which are used for permanent identifying, paging, and location update. This article investigates the existing literature survey about user privacy for 5G networks, which continues the identity and location privacy. Also, it discusses most of the studies that handle user identifications in authentication, paging, and location update. This article discusses the various privacy issues in the 5G network that use IMSI in clear text or temporary identities such as TMSI & C‐RNTI with IMSI to disclose user identity privacy. This article also investigates the existing literature on user identity and location privacy and highlights the key parameters, issues, challenges, and future recommendations with potential solutions.
Low‐complexity GNSS carrier leakage detection and estimation via abnormal direct current energy identification
Authors: Bai Lu , Sun Chao , Zhao Hongbo , Feng Wenquan
Published: March 2022

Carrier leakage due to faults within the satellite payload results in a waste of transmit power and affects the receiver functions. The existing methods are generally performed in the transform domain with high computation load and are unable to estimate the carrier leakage power. This letter presents a low‐complexity algorithm by monitoring the abnormal direct current component of baseband signal. The quantitative relationship between carrier leakage power and test statistics is derived here, and the capability of carrier leakage power estimation is provided. Analytical and simulation results show that it achieves a detection rate of more than 99% for carrier‐to‐noise ratio larger than 42 dB‐Hz and coherent integration time larger than 10 ms. It also greatly saves millions of multiplications compared with the conventional frequency‐domain method.
Study on a small‐signal analysis method for PMSG considering LVRT control and frequency regulation
Authors: Xiao Fan , Xia Yongjun , Zhang Kanjun , Li Hengxuan , Chen Kun , Li Peng
Published: March 2022

In a high proportion of new energy grids or a 100% new energy source of power grid, the dynamic performance of PMSG under fault conditions is very important. However, the current small signal model lacks detailed and deep analysis of a permanent‐magnet synchronous generator (PMSG)‐based wind power generation under LVRT control. Here, a small signal model of a PMSG under pre‐fault, fault and after fault failure recovery stages are established. This paper employs linear analyses to characterize the dynamic performance of a PMSG‐based wind power generation system under LVRT control and practical generator characteristics. In particular, the conflict between frequency regulation and LVRT is discussed based on the constructed model. On this basis, the impact of dc‐link bandwidth on the system performance during failure recovery stage is discussed, and the active damping method is analysed to improve the performance of PMSG during failure and failure recovery stages. Finally, time‐domain simulations are utilized to verify the analyses and models discussed. The research results in this paper are helpful to promote and improve the performance of PMSG during LVRT conditions.
COLF‐GAN: Learning to axial super‐resolve focal stacks
Authors: Xiao Zhaolin , Liu Huan , Jin Haiyan
Published: March 2022

In order to generate a denser focal stack, a cooperative generative adversarial network is proposed to learn the refocusing ability from light field imaging. To keep the axial continuity, the proposed framework is designed to learn features of a focal stack in both axial directions. Different from the classic generative adversarial network, our generative module consists of a forward prediction sub‐network and a backward prediction sub‐network, taking the forward‐and‐backward focal stacks as their inputs, respectively. The bi‐directional predictions are then fused by a weighting process, which is guided by an adversarial module. The proposed network is trained on light field focal stacks conducted via digital refocusing. Without loss of the refocus continuity, one can axial super‐resolve a focal stack by using the trained model. The effectiveness of the proposed algorithm on different types of focal stacks produced by both light fields and traditional camera shootings is validated. The experimental results indicate that the refocus variation of a focal stack can be well learned and predicted without a complete light field. Therefore, the proposed algorithm outperforms the traditional digital refocusing in terms of run‐time.
Single‐phase small capacitor motor drive system with high‐efficiency buck active power decoupling converter
Authors: Zhang Chao , Xu Lei , Zhu Xiaoyong , Du Yi , Quan Li
Published: February 2022

This paper proposes a novel active power decoupling circuit (APDC) based on modified Buck converter to reduce the DC‐link voltage ripple of small capacitor motor drive systems. The APDC is placed between the Boost PFC circuit and the DC‐link, and has two energy flow paths, and the sum of the power decoupling capacitor and the DC‐link capacitor voltage equals to the output voltage of the Boost converter. With these configurations, the voltage of the decoupling capacitor can be precisely controlled to be the same as the AC component of the output voltage of the Boost converter, thereby effectively reducing the DC‐link voltage ripple. Another unique feature of the proposed APDC is that the inductor works in discontinuous current mode and only work for half of the time, which not only reduces the current stress of power switches, but also further improves the efficiency of the proposed APDC. Then, an instantaneous voltage control method is investigated to reduce the DC‐link voltage drop, which significantly improve the dynamic performance of the motor. The design guideline of key components is given in detail. The feasibility of the small capacitor motor drive system based on the proposed APDC is verified by experimental results.
Numerical demonstration of a transactive energy trading model for microgrids
Authors: Crasta Cletus , Mishra Sambeet , Agabus Hannes , Palu Ivo , Wen Fushuan
Published: March 2022

Bidirectional power flow is becoming increasingly commonplace in modern distribution systems with the integration Renewable Energy Sources (RESs) and Energy Storage Systems (ESSs). This has facilitated in bringing generation closer to end‐consumers, thus leading to the emergence and rapid growth of microgrids. Additionally, due to the technological revolution in Information and Communications Technology (ICT), innovative business models have developed where willing and able participants of the power system can participate in the electricity market. In line with this evolution of both the electric power system and its participants, Energy‐as‐a‐Service (EaaS) is emerging as an increasingly prominent business model to address electrical grid challenges economically. EaaS encourages electricity grid customers to play a more active role and participate in different electricity markets. This paper introduces and simulates a variant of a Transactive Energy (TE) trading algorithm for microgrids. The paper describes the model in brief how multiple microgrids assets can trade electricity to ensure more efficient and economical local resource utilization. The main motivations of this research paper is to validate and test the suitability of the TE trading algorithm for a variety of conditions. The coordinated TE trading model can optimize expansion and investment planning especially at the distribution level.
Optimal planning of solar PV and battery storage with energy management systems for Time‐of‐Use and flat electricity tariffs
Authors: Pan Xincheng , Khezri Rahmat , Mahmoudi Amin , Muyeen SM
Published: March 2022

This paper determines the optimal capacity of solar photovoltaic (PV) and battery energy storage (BES) with novel rule‐based energy management systems (EMSs) under flat and time‐of‐use (ToU) tariffs. Four schemes are investigated based on the combinations of flat and ToU tariffs for buying and selling the electricity: (1) Flat‐Flat, (2) ToU‐Flat, (3) Flat‐ToU, and (4) ToU‐ToU. For each scheme, two configurations are evaluated: (i) PV only, and (ii) PV‐BES. The optimization of the grid‐connected household is evaluated based on one‐year realistic data. An uncertainty analysis is presented based on the variations of insolation, temperature, and load. Sensitivity analyses are implemented based on the average daily load, the grid constraint, and the costs of PV and BES. The operational analyses for 48 h in summer and winter are carried out to evaluate the dynamic performance of the systems for high and low solar insolation. The effectiveness of the proposed model is verified by comparing the results with that of common EMS based on the net metering scheme. It is found that the COE of the proposed EMS for a PV‐BES house with ToU‐Flat scheme (as the best option) is 2 ¢/kWh lower than that of the net metering scheme.
Review of energy sharing: Business models, mechanisms, and prospects
Authors: Chen Yue , Zhao Changhong
Published: March 2022

The development of distributed generation technology is endowing consumers the ability to produce energy and transforming them into “prosumers”. This transformation shall improve energy efficiency and pave the way to a low‐carbon future. However, it also exerts critical challenges on system operations, such as the wasted backups for volatile renewable generation and the difficulty to predict behaviour of prosumers with conflicting interests and privacy concerns. An emerging business model to tackle these challenges is energy sharing, whose concepts, structures, applications, models, and designs are thoroughly reviewed in this paper, with an outlook of future research to better realise its potentials.
A consistency method of discharge detection results at solar‐blind ultraviolet based on a radiation transmission model
Authors: Liu Yunpeng , Li Yonglin , Geng Jianghai , Cui Muhan , Huang Shilong
Published: March 2022

Solar‐blind ultraviolet (UV) discharge detection based on UV signals in the solar‐blind band from 240 to 280 nm is an effective non‐contact discharge detection method for electrical equipment, but there is still a problem that the detection results of different types of UV imagers are not comparable. To this end, by using standard light source and MODTRAN model, the relationship between the facular area and the radiant flux received by UV imagers was investigated by establishing a radiation transmission model for UV detection under different environmental conditions. Through analysis, it was found that the influence of humidity on the transmittance of the solar‐blind band in atmosphere can be neglected, and the transmittance is slightly affected by atmospheric pressure, temperature, and detection distance under conditions suitable for UV detection. Moreover, a consistency formula for UV detection results was proposed, thus forming a consistency method for detection results suitable for various types of UV imager. Finally, the feasibility of the consistency method was verified by UV discharge detection tests with a rod‐plate model and the absolute irradiance at discharge points of the rod‐plate model measured by a grating spectrometer. The consistency method is conducive to the promotion of UV discharge detection technology.
An algorithm for the grade-two rheological model
Authors: Pollock Sara , Scott L. Ridgway
Published: March 2022

We develop an algorithm for solving the general grade-two model of non-Newtonian fluids which for the first time includes inflow boundary conditions. The algorithm also allows for both of the rheological parameters to be chosen independently. The proposed algorithm couples a Stokes equation for the velocity with a transport equation for an auxiliary vector-valued function. We prove that this model is well posed using the algorithm that we show converges geometrically in suitable Sobolev spaces for sufficiently small data. We demonstrate computationally that this algorithm can be successfully discretized and that it can converge to solutions for the model parameters of order one. We include in the appendix a description of appropriate boundary conditions for the auxiliary variable in standard geometries.
Evaluation of Uterocervical Angle and Cervical Length as Predictors of Spontaneous Preterm Birth
Authors: Singh Pramod Kumar , Srivastava Resham , Kumar Ishan , Rai Sangeeta , Pandey Saurabh , Shukla Ram C. , Verma Ashish
Published: March 2022

Aim The aim of this article was to evaluate uterocervical angle (UCA) and cervical length (CL) measured at 16 to 24 weeks of gestation using transvaginal sonography (TVS) as predictors of spontaneous preterm birth.

Methods In this prospective study, TVS was performed in 159 primigravidas with a singleton, uncomplicated pregnancy at 16 to 24 weeks of gestation to measure the anterior UCA and CL. All the cases were followed until labor to document gestational age at delivery.

Results The risk of spontaneous preterm birth was higher in women with obtuse UCA (>95 degrees) with sensitivity of 86.7%, specificity of 93.0%, positive predictive value of 83.0%, negative predictive value of 94.6%, and p-value of <0.001. The difference between the means was statistically significant (p-value < 0.001). UCAs ≥105degrees and 95 to 105 degrees were found to be significantly associated with spontaneous preterm births at <34 weeks and 34 to 37 weeks, respectively. CL <2.5 cm was found to predict spontaneous preterm births at <37 weeks with sensitivity of 31.1%, specificity of 95.6%, and p-value of <0.001. UCA was found to be a better predictor of spontaneous preterm birth with a higher coefficient of variation (56.4%) when compared with CL (16.9%).

Conclusions UCA proved to be a novel ultrasound parameter that can serve as a better predictor of spontaneous preterm births in comparison to CL. A strong correlation exists between obtuse UCA and a risk of spontaneous preterm birth.
Screening for Early Detection of Cervical Cancer in Women Living with HIV in Mumbai, India - Retrospective Cohort Study from a Tertiary Cancer Center
Authors: Pimple Sharmila A. , Pahwa Vandita , Mishra Gauravi A. , Anand Kavita V. , Pathuthara Saleem , Biswas Sanjay K.
Published: February 2022

Introduction Women living with human immunodeficiency virus (HIV) have an increased risk of persistent human papillomavirus infection (HPV) of developing cervical cancer precursors and are, therefore, considered at higher risk for cervical cancer. Despite the higher risk, screening for cervical cancer is extremely low among HIV-positive women in India.

Objectives Given the limited usefulness of cytology-based screening programs, the current study retrospectively evaluated the comparative performance of visual inspection with 5% acetic acid (VIA), conventional cytology, and human papillomavirus (HPV) testing among HIV-positive women attending the cancer screening clinic at the tertiary cancer center.

Materials and Methods Retrospective analysis of 291 HIV-positive women attending cervical cancer screening services in a tertiary cancer center in Mumbai was undertaken. All underwent simultaneous screening with VIA, Pap cytology, and HPV DNA testing, followed by diagnostic colposcopy and histopathology. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to detect cervical intraepithelial neoplasia (CIN) 2/3 on histology were estimated.

Results The screen positivity rate for cervical cancer screening by VIA, high-risk HPV DNA, and Pap cytology was 35.7, 34.4, and 6.2% respectively. At the CIN2+ disease threshold, the sensitivity, specificity, PPV, and NPV estimates were 80.00% (59.30–93.17), 68.42% (62.46–73.96), 19.23% (15.46–23.67), 97.33% (94.30–98.77) for VIA; 80.00% (68.78–97.45), 70.68% (64.81–76.08), 22.00% (18.22–26.32), 98.43% (95.58–99.45) for HPV DNA; and 64.00% (42.52–82.03), 98.12% (95.67–99.39), 76.19% (56.13–88.89), 96.67% (94.50–98.00) for cytology (HSIL cutoff).

Conclusion The diagnostic performance of VIA and HPV DNA was comparable and better than cytology indicating that VIA as a cost-effective cervical cancer screening test can be incorporated within the services under sexually transmitted diseases /HIV testing and counseling centers within the country.
Comparison of Two Standard Treatment Approaches in Locoregionally Advanced Nasopharyngeal Carcinoma
Authors: Mohamad Issa , Abu-Hijleh Fawzi , Mayta Ebrahim , Abu-Hejleh Taher , Al-Gargaz Wisam , Al Mousa Abdellatif , Abu-Hijlih Ramiz , Hosni Ali
Published: February 2022

Objectives To compare outcomes and toxicity of two standard treatment approaches of advanced nasopharyngeal carcinoma (NPC).

Methods Between 2010 and 2016, patients with NPC, stage II–IVa, treated with induction chemotherapy (IC) (TPF), followed by concurrent chemoradiotherapy (CCRT) (induction group), or CCRT, followed by adjuvant chemotherapy (AC) (PF) (no-induction group), were retrospectively reviewed. CCRT included platinum-based chemotherapy with intensity-modulated radiotherapy. Survival outcomes, the pattern of failures, toxicity, and predictors for survival outcomes were evaluated.

Results A total of 110 patients were included, 65 in the induction group and 45 in the no-induction group. There were no significant differences in the DFS and overall survival (OS) at 3 years between the two groups. On multivariate analysis, performance status (1 vs. 0) predicted worse OS. The 3-year cumulative incidence rates for local, regional, and distant failures were 58.5% (95% confidence interval [CI]: 8.4–89%), 58.00% (95% CI: 8–88.8%), and 63.90% (95% CI: 14.1–90.2%), respectively. IC had more frequent acute grade (G) II anemia (13 vs. 1, p < 0.01), late G II brain toxicity (4 vs. 1, p < 0.01), and late G II dysphagia (32 vs. 11, p = 0.01).

Conclusions Survival outcomes were comparable between the two groups. IC had more frequent acute G II anemia and late G II brain and esophageal toxicities.
Utilization of the Caprini Score for Risk Stratification of the Arthroplasty Patient in the Prevention of Postoperative Venous Thrombosis
Authors: Krauss Eugene S. , Segal Ayal , Dengler Nancy , Cronin MaryAnne , Pettigrew Janelle , Simonson Barry G.
Published: March 2022

Venous thromboembolism (VTE) is a serious and predictable complication following arthroplasty. It has been recognized that a strategy utilizing individualized anticoagulation choices based on patient risk stratification results in improved patient outcomes. A 2013 version of the Caprini Risk Score has previously been validated for use in total joint arthroplasty. A Caprini score of 10 or greater assesses the patient as “high risk” while 9 or less is considered “low risk.” Patients scored as “low risk” for postoperative VTE receive enteric coated aspirin 81 mg twice a day for 6 weeks. Patients scored as “high risk” for VTE are prescribed apixaban. This retrospective cohort study was conducted to assess the safety and efficacy of the thromboprophylaxis treatment prescribed based on a standardized risk assessment protocol for the calendar year 2020. Patients having total hip arthroplasty, total knee arthroplasty, revision total hip arthroplasty, revision total knee arthroplasty, or bilateral arthroplasties by 13 surgeons (N = 873) were reviewed. Patients were risk assessed using the Caprini Risk Score and thromboprophylaxis was prescribed based on the score obtained. The annual rate of VTE was 0.2%. The Caprini Risk Score is an effective approach to individualize thromboprophylaxis choices after total joint arthroplasty.
Review of Extensor Mechanism Injuries in the Dislocated Knee
Authors: Okoye Munachukwudi , Wissman Abigail , Wissman Robert D.
Published: March 2022

Knee dislocations, aka multiligamentous injuries, are uncommon but devastating injuries often following high-energy trauma. Tears of the major knee stabilizers are well documented; however, injuries of the knee extensor mechanism are less commonly reported. The extensor mechanism is comprised of the patella, patellar tendon, and quadriceps tendons. Magnetic resonance imaging (MRI) is the preferred imaging modality of internal derangements of the knee due to its excellent soft tissue contrast. In this article, we will discuss the normal imaging findings of the extensor mechanism and review abnormalities following knee dislocation.
Aging Affects Hemispheric Asymmetry on a Competing Speech Task
Authors: Greenwald Ralf R. , Jerger James
Published: March 2022

This study examined the effects of aging on the hemispheric asymmetry of event-related potentials (ERPs) evoked by morphosyntactic anomalies in a competing speech paradigm. The experimental groups consisted of children, young adults, and elderly persons.The ERPs were recorded from 32 scalp sites while participants listened to a continuous narrative presented quasidichotically via loudspeakers. Participants responded when they heard an anomalous word embedded within a popular fairy tale. Anomalous words evoked a robust positivity in the 700– to 900–msec latency range in all participants. Comparison of area measures from waveforms at the lateral frontal, frontotemporal, temporal, temporoparietal, and parietal electrode sites revealed asymmetry in hemispheric positivity. In children and young adults, asymmetry peaked in the 600– to 800–msec range and favored the left hemisphere in both target-right and target-left conditions. In seniors, however, asymmetry peaked at 1100 msec, favored the left hemisphere in the target-right condition, and favored the right hemisphere in the target-left condition. These results support the concept that aging affects hemispheric asymmetry during linguistic processing.

Abbreviations : EEG = encephalographic, ERP = event-related potential, VEOG = vertical electro-oculographic activity
Paired-Comparison Hearing Aid Preferences: Evaluation of an Unforced-Choice Paradigm
Authors: Punch Jerry L. , Rakerd Brad , Amlani Amyn M.
Published: March 2022

Fifteen normal-hearing listeners compared nine frequency-response slopes in a round-robin paired-comparison tournament as they listened to passages of connected discourse against a competing noise background at a +3–dB signal-to-noise ratio. All participants listened in an AB paradigm, in which they were forced to choose which of two signals (A or B) produced better speech intelligibility, and an ABN paradigm, in which they were allowed a third choice of No Preference (N). For both paradigms, listeners generally preferred frequency shaping that either cut low frequencies or boosted high frequencies, and intra- and intersession reliability was high overall. Although listeners’ most-preferred responses tended to converge on the same frequency-response slope in the two paradigms, the reliability of these responses was significantly higher for ABN than for AB. The use of the ABN paired-comparison paradigm deserves further study, therefore, as a method to fit multimemory hearing aids.

Abbreviations: AB = traditional (forced-choice) paired-comparison paradigm, ABN = experimental (unforced-choice) paired-comparison paradigm, RSIR = Revised Speech Intelligibility Rating test, SIR = Speech Intelligibility Rating test, SNR = signal-to-noise ratio
Efficacy of Directional Microphone Hearing Aids: A Meta-Analytic Perspective
Authors: Amlani Amyn M.
Published: March 2022

The literature suggests that directional microphone hearing aids (DMHAs) are a viable means for improving the signal-to-noise ratio (SNR) for hearing-impaired listeners. The amount of directional advantage they provide, however, remains relatively unclear because of variability observed among individual studies. The present investigation was undertaken in an attempt to establish the degree of advantage provided by DMHAs. Data were synthesized from 72 and 74 experiments, respectively, on omnidirectional hearing aids and DMHAs representing both favorable and unfavorable outcomes. Using a meta-analytic approach, 138 weighted averages were derived for a variety of comparable independent and dependent variables. Comparisons were made for hearing-impaired and normal-hearing listeners. Findings are discussed with regard to their clinical and research implications.

Abbreviations: BTE - behind the ear, Cl95 = 95 percent confidence interval, DA = directional advantage, DMHA = directional microphone hearing aid, DSP = digital signal processing, HI = hearing impaired, ITE = in the ear, NH = normal hearing, ODHA = omnidirectional microphone hearing aid, RT = reverberation time, SNR = signal-to-noise ratio.
Newborn Hearing Screens May Give a False Sense of Security
Authors: Mann Toni , Cuttler Karrie , Campbell Chanda
Published: March 2022

Certain risk factors result in a higher incidence of delayed-onset hearing loss. Ten subjects who passed auditory brainstem response birth screenings and later returned with bilateral sensorineural hearing loss are examined in this report. Although not all subjects in this report had respiratory distress, this study reveals a high correlation between mechanical ventilation and delayed-onset hearing loss.

Abbreviations: ABR = auditory brainstem response, ECMO = extracorporeal membrane oxygenation, JCIH = Joint Committee on Infant Hearing, MAS = meconium aspiration syndrome, NICU = neonatal intensive care unit, OAE = otoacoustic emissions, PFC = persistent fetal circulation, PPHN = persistent hypertension of the newborn, RDS = respiratory distress syndrome
Numerical investigation of transonic buffet on a prescribed-pitching OAT15A airfoil
Authors: Han Bing , Xu Min , Chen Guoguang , Cai Tianxing , Wang Wenhu , Guan Shixi
Published: March 2022

The transonic buffet over a prescribed-pitching OAT15A airfoil was numerically investigated using a well-validated delayed detached eddy simulation approach. The present approach successfully reproduced self-sustained shock wave oscillations. The computational results show that the amplitude of the lift fluctuations in the pitching case is approximately six times that of the fixed case. Compared to the fixed case, the presence of a larger shock motion region, two shock wave interactions, and severe boundary separation give rise to higher pressure and velocity fluctuation levels on the whole upper surface in the pitching case. In particular, the highly disordered flow replaces the periodic vortex shedding in the wake, resulting in the disappearance of the secondary fluctuation in unsteady lift coefficients, which is observed at 2274 Hz in the fixed case. A proper orthogonal decomposition analysis shows that the buffet flow in the fixed case exhibits the feature of regular motion, which is closely related to the coherent flow structure of shock oscillations and Karman vortices. Strong interactions between the Karman vortex structure and the shock oscillations are also observed. Compared to those in the fixed case, the fluctuation amplitudes of the coefficients of the first mode pair and the second to fourth mode pairs in the pitching case are 2.5 times and 5 times larger, respectively, and the energy ratio of the nonlinear component in the total mode energy is significantly increased. Furthermore, the main frequencies of modes 1–10 in the pitching case are all located at the shock buffet frequency or its higher-order harmonics.
Tuning the shell structure deformation of APS thermal barrier coatings: A molecular dynamics study
Authors: Zhong Si-Fan , Jiang Jin-Wu
Published: March 2022

A key parameter for the performance of ceramic topcoats in a thermal barrier coating is the porosity, which is sensitive to many growing conditions. In the present work, molecular dynamics simulations are performed to investigate the microscopic mechanism for the dependence of the porosity on several experimental conditions in the atmospheric plasma spraying deposition process, including temperature, substrate roughness, and the thickness-to-radius ratio of the yttrium-stabilized zirconia shell. These factors can significantly modify the porosity through changing the buckling mode of the yttrium-stabilized zirconia shell. Our findings provide some microscopic mechanisms for improving the deposition quality of the atmospheric plasma spraying thermal barrier coatings.
A survey of MEMS cantilever applications in determining volatile organic compounds
Authors: Vasagiri Suresh , Burra Rajesh Kumar , Vankara Jyothi , Kumar Patnaik M.S. Pradeep
Published: March 2022

Recently, microelectromechanical system (MEMS) cantilevers have received significant interest in the domain of Volatile Organic Compounds (VOCs). An analysis of MEMS cantilevers in VOCs is presented in this Review. It examines the different forms of sensors used to detect VOCs. It goes into the conditions that influence MEMS and the strategies used for VOC sensing. It examines research on MEMS cantilevers and other VOC sensing and detection techniques. It shows how MEMS can be used to detect VOCs. Moreover, it presents a comparative study based on the objectives, types of sensors employed, merits, and shortcomings of existing works. This Review intends to explore MEMS cantilevers in VOCs for supporting further research and applications.
Piezoelectric property of PZT nanofibers characterized by resonant piezo-force microscopy
Authors: Zhang Guitao , Chen Xi , Xu Weihe , Yao Wei-Dong , Shi Yong
Published: March 2022

Nano-piezoelectric materials have drawn tremendous research interest. However, characterization of their piezoelectric properties, especially measuring the piezoelectric strain coefficients, remains a challenge. Normally, researchers use an AFM-based method to directly measure nano-materials’ piezoelectric strain coefficients. But, the extremely small piezoelectric deformation, the influence from the parasitic electrostatic force, and the environmental noise make the measurement results questionable. In this paper, a resonant piezo-force microscopy method was used to accurately measure the piezoelectric deformation from 1D piezoelectric nanofibers. During the experiment, the AFM tip was brought into contact with the piezoelectric sample and set to work at close to its first resonant frequency. A lock-in amplifier was used to pick up the sample’s deformation signal at the testing frequency. By using this technique, the piezoelectric strain constant d33 of the Lead Zirconate Titanate (PZT) nanofiber with a diameter of 76 nm was measured. The result showed that d33 of this PZT nanofiber was around 387 pm/V. Meanwhile, by tracking the piezoelectric deformation phase image, domain structures inside PZT nanofibers were identified.
Ultra-low resistance n+GaN contacts for GaN HEMT applications using MOCVD selective area epitaxy in N2 carrier gas
Authors: Li Jizhong , Brabant Paul , Hannan Dan , Vasen Tim , Afroz Shamima , Nagamatsu Ken , Chang Josei , Shea Patrick , Lawson David , Howell Rob
Published: March 2022

Low resistance n+GaN contact materials were experimentally studied for GaN HEMT applications by selective area epitaxy regrowth on a patterned SiC substrate. Epitaxy was performed by metal organic chemical vapor deposition using 100% H2 or 100% N2 as the carrier gas. Thin film characterization demonstrated that n+GaN grown in N2 carrier gas has a superior morphology with improved crystalline quality to that grown in H2 carrier gas. The results also indicated that the surface morphology of n+GaN grown in N2 carrier gas is less sensitive to mask pattern density and micro-loading effects with Si doping concentrations up to 1 × 1020/cm3. Secondary ion mass spectrometry analysis shows that C and O impurity levels in n+GaN are one order of magnitude lower with N2 carrier gas than with H2. The electrical measurement of transmission line model structures shows an n+GaN sheet resistance of 15 Ω/sq and an Ohmic metal to n+GaN contact resistance of 0.02 Ω-mm for structures grown in N2 carrier gas. These values represent 7.1× and 2.5× improvements compared to H2 carrier gas.
Crown fuel consumption in Canadian boreal forest fires
Authors: de Groot William J. , Hanes Chelene C. , Wang Yonghe
Published: February 2022

Predictive crown fuel consumption models were developed using empirical data from experimental burning projects. Crown fuel load for foliage, bark, branchwood and stemwood were calculated for live overstorey and understorey trees in each plot using nationally derived tree biomass algorithms. Standing dead tree branchwood and stemwood biomass were similarly calculated. Crown bulk density values were calculated for all non-stemwood fuel components. Factors that affect the initiation and spread of crown fires (live crown base height, foliar moisture content, surface fuel consumption, critical surface fire spread rate, critical surface fire intensity) and components of the Canadian Forest Fire Weather Index System were not statistically significant variables. Crown bulk density was moderately correlated with crown fuel consumption but was not an influential factor. A new crown fuel consumption model was developed by regression analysis using fuel load of overstorey tree foliage and standing dead tree branchwood, and fire rate of spread through crown fraction burned. A simpler model was developed using only overstorey tree foliage fuel load and fire rate of spread. Both models provide forest and fire management agencies with enhanced ability to determine crown fuel consumption, fire behaviour and carbon emissions in boreal fires using basic forest inventory or biomass/carbon datasets.