bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Dual-band Ambient RF Energy Harvesting System for Autonomous Wireless Sensor Node Application
Authors: Le Minh Thuy , Pham Duc Anh , Vu Hong Tien , Ngo Van Duc , Nguyen Quoc Cuong
Published: March 2022

This paper presents a novel dual-band ambient Wi-Fi energy harvesting system for an autonomous wireless sensor node (AWSN) which operates independently without other external power source. While conventional wireless sensor nodes employing batteries with limited lifespans, an AWSN is supplied by harvested energy and does not require frequent battery replacement. Due to that reason, research on the energy harvesting aspect of AWSNs has been carried out intensively in recent years. By optimizing the matching network, the proposed ambient Wi-Fi energy harvesting system achieves a relatively good efficiency in dual-band at 2.45 GHz and 5.8 GHz. The efficiency reaches a peak at 47.45 % and 42 % at 2.45 GHz and 5.8 GHz, respectively. The proposed idea is numerically and experimentally demonstrated with the Wi-Fi source in building.
Design and Analysis of a Novel Linear Oscillating Actuator with Dual Stator Rectangular Geometry
Authors: Jawad Muhammad , Haitao Yu , Ahmad Zahoor , Liu Yulei
Published: March 2022

This paper proposes a new design of a linear oscillating actuator (LOA) with rectangular topology of stator and mover. The shape of a permanent magnet (PM) has a major impact on cost, mechanical strength and generation of magnetic flux density. This design uses rectangular PMs that are relatively cheaper than tubular PMs. Proposed LOA operates on single phase AC loading source. All the design parameters are optimized by using parametric sweep and the response of the LOA in terms of thrust force is compared. The Electromagnetic (EM) force received by the mover is investigated at various mover positions as well as at different values of the current. Motor constant is examined toward both directions of the force. Resonance phenomena is analyzed using input and output power of the LOA, which is the unique advantage of the LOA. Compared to the conventional LOA designs, the output parameters of the LOA, such as EM force, stroke, operating frequency and power, show great improvement with regards of volume of the proposed LOA. This topology shows significant development in terms of thrust force, motor constant, easy manufacturing and cost. Moreover, range of the stroke of proposed LOA is feasible for linear refrigeration system.
A Compact Bandstop Filter Design Using DMS-DGS Technique for Radar Applications
Authors: Dokmetas Burak , Arican Galip Orkun , Akcam Nursel , Yazgan Erdem
Published: March 2022

In this study, a novel compact bandstop filter (BSF) by utilizing the defected ground structure (DGS) and defected microstrip structure (DMS) techniques are presented. DGS, DMS, and compensated capacitors are used on both bottom and top layers to obtain sharp transition and wider stopband. The operating frequency bandwidth of the filter can be comfortably regulated by tuning the dimensions of the etched structures. In addition to parametric studies, an equivalent circuit model of the proposed filter is extracted. The BSF has an insertion and return losses better than –1.6 and –17 dB in the passband, respectively. Moreover, the developed filter covers X-band frequency range and has stop bandwidth of 10.8–11.8 GHz with the rejection of better than 20 dB. Furthermore, the measurement and simulation results are in compliance with the suggested method. The proposed BSF has a very small size of 14.28 mm ×× 4 mm ×× 0.508 mm and has the potential to be used for radar applications with its high compactness, low cost, and high harmonic rejection performance.
Particle Swarm Optimization of Irregular-shaped Hexagon Patch Antenna for 2.4 GHz WLAN Applications
Authors: Weng Wei-Chung , Chang Min-Chi
Published: March 2022

This study proposes a patch antenna with an irregular shape on a radiating metal patch for 2.4 GHz WLAN applications. The proposed antenna is optimized using our in-house designed particle swarm optimization (PSO) method. By optimizing the coordinates of each vertex of the hexagon radiating metal patch, the PSO algorithm successfully extends the impedance bandwidth and antenna gain without increasing the size, cost, and complexity of the antenna. The optimized antenna has a unique and irregular shape. Measured impedance bandwidth of 7.71% (2.37–2.56 GHz) and peak gain of 2.84 dBi of the proposed irregular-shaped patch antenna are obtained. The simulated and measured results of reflection coefficient, gain, and far-field radiation are found to be in good agreement with each other, hence evidently confirming the validity of the proposed method. The proposed irregular shaped hexagon patch antenna demonstrates superior performance of impedance bandwidth and antenna gain compared to those of the regular-shaped hexagon patch antenna.
Simulation-driven learning: a deep learning approach for image scanning microscopy via physical imaging models
Authors: Zhang Baoyuan , Sun Xuefeng , Yang Hongxia , Guo Cheng , Wu Biwei , Tan Jiubin , Wang Weibo
Published: March 2022

Image reconstruction based on deep learning has become an effective tool in fluorescence microscopy. Most deep learning reconstruction methods ignore the mechanism of the imaging process where a large number of datasets are required. In addition, a lot of time is spent solving the aliasing problem from multi-scaled image pairs for data pre-processing. Here we demonstrate an improved generative adversarial network for image scanning microscopy (ISM) that can be trained by simulation data and has good generalization. Based on physical imaging models, this method can generate matching image pairs from simulation images and uses them as datasets for network training, without capturing a large number of real ISM images and avoiding image alignment preprocessing. Simulation and experimental results show that this simulation data-driven method improves the imaging quality of conventional microscopic images and reduces the cost of experiments. This method provides inspiration for optimizing network generalizability of the deep learning network.
Characterizing warm atmospheric boundary layer over land by combining Raman and Doppler lidar measurements
Authors: Chu Yufei , Wang Zhien , Xue Lulin , Deng Min , Lin Guo , Xie Hailing , Shin Hyeyum Hailey , Li Weiwei , Firl Grant , D’Amico Daniel F. , Liu Dong , Wang Yingjian
Published: March 2022

PBL plays a critical role in the atmosphere by transferring heat, moisture, and momentum. The warm PBL has a distinct diurnal cycle including daytime convective mixing layer (ML) and nighttime residual layer developments. Thus, for PBL characterization and process study, simultaneous determinations of PBL height (PBLH) and ML height (MLH) are necessary. Here, new approaches are developed to provide reliable PBLH and MLH to characterize warm PBL evolution. The approaches use Raman lidar (RL) water vapor mixing ratio (WVMR) and Doppler lidar (DL) vertical velocity measurements at the Southern Great Plains (SGP) atmospheric observatory, which was established by the Atmospheric Radiation Measurement (ARM) user facility. Compared with widely used lidar aerosol measurements for PBLH, WVMR is a better trace for PBL vertical mixing. For PBLH, the approach classifies PBL water vapor structures into a few general patterns, then uses a slope method and dynamic threshold method to determine PBLH. For MLH, wavelet analysis is used to re-construct 2-D variance from DL vertical wind velocity measurements according to the turbulence eddy size to minimize the impacts of gravity wave and eddy size on variance calculations; then, a dynamic threshold method is used to determine MLH. Remotely-sensed PBLHs and MLHs are compared with radiosonde measurements based on the Richardson number method. Good agreements between them confirm that the proposed new algorithms are reliable for PBLH and MLH characterization. The algorithms are applied to warm seasons’ RL and ML measurements at the SGP site for five years to study warm season PBL structure and processes. The weekly composited diurnal evolutions of PBLHs and MLHs in warm climate were provided to illustrate diurnal and seasonal PBL evolutions. This reliable PBLH and MLH dataset will be valuable for PBL process study, model evolution, and PBL parameterization improvement.
Dispersion compensation of high-speed data using an integrated silicon nitride ring resonator
Authors: Ong K. Y. K. , Chen G. F. R. , Xing P. , Gao H. , Tan D. T. H.
Published: March 2022

Dispersion impairments are a well-known limitation in data center communications, limiting both the usable data rates and reaches. Several companies today adopt silicon photonics as a core technology in their transceiver products. This presents an opportunity for silicon photonics-based dispersion management technologies to be integrated with the transceiver transmitter or receiver. In this manuscript, we present a ring-resonator based, tunable dispersion compensation device, providing dispersion ranging as wide from  + 12.9 × 103ps/nm to −12.3 × 103ps/nm. Thermo-optic tuning from 20°C to 70°C is demonstrated to allow continuous wavelength tuning across 200 GHz. High-speed experiments using 25 Gb/s non-return-to-zero data propagating through 20 km of single mode fiber show that a significant improvement in the eye diagram is achieved after compensation with the ring-resonator device. We demonstrate a significant improvement in the BER from 10−3 to 10−11 for data rates of 25 and 25.78125 Gb/s.
Directly modulated optical negative feedback lasers for long-range FMCW LiDAR
Authors: Yokota Nobuhide , Kiuchi Hiroki , Yasaka Hiroshi
Published: March 2022

Frequency sweep operation of directly modulated optical negative feedback lasers is numerically and experimentally investigated for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR) with a high signal-to-noise ratio (SNR), particularly over a long range. Low FM noise corresponding to a spectral linewidth of ∼2.0 kHz is sustained even with injection current modulation of an optical negative feedback laser through optical feedback from a Fabry-Perot etalon, and a beat note spectrum with a 30-dB SNR is achieved even when a 300-m delay fiber is used as a ranging sample. These results encourage an approach to provide directly modulated frequency-swept lasers for long-range FMCW LiDAR.
High-temperature-sensitive and spectrum-contrast-enhanced sensor using a bullet-shaped fiber cavity filled with PDMS
Authors: Liang Jinjin , Li Xin , Li Jinjian , Ye Jingfu , Liu Yi , Chen Ming , Zhang Zhenrong , Qu Shiliang
Published: March 2022

Low temperature sensitivity and low spectral contrast are serious but common issues for most Fabry Perot (FP) sensors with an air cavity. In this paper, a high-temperature-sensitive and spectrum-contrast-enhanced Fabry Perot interferometer (FPI) is proposed and experimentally demonstrated. The device is composed of a hollow cylindrical waveguide (HCW) filled with polydimethylsiloxane (PDMS) and a semi-elliptic PDMS end face. The semi-elliptic PDMS end face increases the spectral contrast significantly due to the focusing effect. Experimentally, the spectral contrast is 11.97 dB, which is two times higher than the sensor without semi-elliptic PDMS end face. Ultra-high temperature sensitivity of 3.1501 nm/°C was demonstrated. The proposed sensor exhibits excellent structural stability, high spectral contrast and high temperature sensitivity, showing great potential in biomedicine, industrial manufacturing, agricultural production and other applications.
Omnidirectional nonreciprocal absorber realized by the magneto-optical hypercrystal
Authors: Hu Shengyu , Song Juan , Guo Zhiwei , Jiang Haitao , Deng Fusheng , Dong Lijuan , Chen Hong
Published: March 2022

Photonic bandgap design is one of the most basic ways to effectively control the interaction between light and matter. However, the traditional photonic bandgap is always dispersive (blueshift with the increase of the incident angle), which is disadvantageous to the construction of wide-angle optical devices. Hypercrystal, the photonic crystal with layered hyperbolic metamaterials (HMMs), can strongly modify the bandgap properties based on the anomalous wavevector dispersion of the HMM. Here, based on phase variation competition between HMM and isotropic dielectric layers, we propose for the first time to design nonreciprocal and flexible photonic bandgaps in one-dimensional photonic crystals containing magneto-optical HMMs. Especially the zero-shift cavity mode and the blueshift cavity mode are designed for the forward and backward propagations, respectively. Our results show maximum absorption about 0.99 (0.25) in an angle range of 20-75 degrees for the forward (backward) incident light at the wavelength of 367 nm. The nonreciprocal omnidirectional cavity mode not only facilitates the design of perfect unidirectional optical absorbers working in a wide-angle range, but also possesses significant applications for all-angle reflectors and filters.
Space-time coupling of the carrier-envelope phase in ultrafast optical pulses
Authors: Attia Ido , Frumker Eugene
Published: March 2022

The carrier-envelope phase (CEP) plays an increasingly important role in precise frequency comb spectroscopy, all-optical atomic clocks, quantum science and technology, astronomy, space-borne-metrology, and strong-field science. Here we introduce an approach for space-time calculation of the CEP in the spatially defined region of interest. We find a significant variation of CEP in the focal volume of refracting focusing elements and accurately calculate its value. We discuss the implications and importance of this finding. Our method is particularly suitable for application to complex, real-world, optical systems thereby making it especially useful to applications in research labs as well as in the engineering of innovative designs that rely on the CEP.
Resonant fiber optic gyroscope using a reciprocal modulation and double demodulation technique
Authors: Liu Lu , Liu Shuang , Hu Junyi , Ma Huilian , Jin Zhonghe
Published: March 2022

A resonant fiber optic gyroscope (RFOG) using a reciprocal modulation and double demodulation technique based on a single laser source is proposed and demonstrated. The effect of the residual amplitude modulation of the phase modulator is well suppressed thanks to the reciprocal modulation and demodulation. On this basis, the backscattering noise is also eliminated by the double demodulation process. The long-term bias stability of the RFOG is successfully improved to 0.2°/h for a test time of 45 hours.
Net 4 Gb/s underwater optical wireless communication system over 2 m using a single-pixel GaN-based blue mini-LED and linear equalization
Authors: Li Xueyang , Cheng Chen , Zhang Chao , Wei Zixian , Wang Lai , Fu H. Y. , Yang Yanfu
Published: March 2022

High-bandwidth GaN-based mini-LEDs on the c-sapphire substrate are promising candidates for underwater optical wireless communication (UOWC) systems due to their compatibility with the mature LED fabrication process. Here we fabricate and characterize mini-LEDs based on a single-layer InGaN active region with a peak emission wavelength around 484 nm for high-speed UOWC links. Since the LED diameter affects the trade-off between the modulation bandwidth and the optical modulation amplitude, mini-LEDs with varying mesa diameters from 100 µm to 175 µm are fabricated for the measurement. The 150 µm mini-LED with a 3-dB optical bandwidth of 906 MHz performs the best and enables the transmission of a net 4 Gb/s PAM-4 signal over 2 m of underwater distance using only linear equalization. This UOWC system has achieved, to the best of our knowledge, the highest net data rate and the highest data-rate-distance product based on a single-pixel mini-LED.
Non-uniform angular spectrum method in a complex medium based on iteration
Authors: Xu Rui , Feng Ming , Chen Ziyu , Yang Jiaxin , Han Dongdong , Xie Jinyue , Song Feng
Published: March 2022

The traditional angular spectrum method has an inherent problem that the region of diffraction propagation should be homogeneous. However, in some cases, the medium of the diffraction propagation region is inhomogeneous. In this Letter, based on iteration we proposed the non-uniform angular spectrum method for diffraction propagation calculation in a complex medium. By phase pre-processing in the spatial domain and diffraction calculation in the spatial frequency domain, the diffraction propagation problem of the light field in a complex medium is solved. Theoretical formulation and numerical examples as well as experimental investigation are presented to confirm the validity of the proposed method. The advantages of this method include faster computation, smaller memory requirement, and the ability to compute a larger area compared with the finite element method as well as the ability to compute the non-paraxial case compared with the standard fast Fourier transform beam propagation method.
Pseudo-spin-valley coupled topological states protected by different symmetries in photonic crystals
Authors: Yan Bei , Peng Yuchen , Shi Aoqian , Xie Jianlan , Peng Peng , Liu Jianjun
Published: March 2022

The quantum spin Hall effect protected by C6 symmetry [realized in the domain wall (DW) formed by a trivial-photonic crystal (TPC) and a nontrivial-PC (NPC)] and the quantum valley Hall effect protected by C3 symmetry [realized in the DW formed by two valley PCs (VPCs)] have been widely researched due to their excellent topological properties. The topological edge states (TESs) and topological corner states (TCSs) at DWs between different symmetric structures remain to be explored, which is essential for connecting waveguides with different symmetries to construct optical communication devices. In this Letter, there is (are) one TES (two TESs) for the DW1 and DW3 (DW2 and DW4) between the TPC (NPC) and two VPCs. Through simulation calculations of the Wilson-loop of the TPC and NPC and the Berry curvature distribution of VPCs, the corresponding relationship between the topological invariant and the number of TESs is obtained. Based on the TPC, NPC, and two VPCs, the waveguides are constructed to verify the realization of TESs. The parity of the gapped TESs is analyzed, and its relationship with the TCSs is obtained. Moreover, box-shaped structures are constructed to verify the appearance of TCSs. These results have a guiding significance for the research of the interaction between topological states protected by different symmetries.
Denoising of Fourier domain quantum optical coherence tomography spectrums based on deep-learning methods
Authors: Liu Tingting , Sun Yifan , Zhang Xiangdong
Published: March 2022

One of the promising optical coherence tomography schemes using quantum light is the Fourier domain quantum optical coherence tomography. It combines the advantage of quantum metrology and the optical coherence tomography, providing a great detection with a high axial resolution. However, the application of the Fourier domain quantum optical coherence tomography is hard to implement since various types of noise would affect the quality and finally eliminate the advantages. In this paper, we quantitively analyze the affection of the noise induced by quantum fluctuation on Fourier domain quantum optical coherence tomography and propose to suppress the effect by deep-learning method. Our simulation shows that it could severely lower the accuracy of the detection, and can be removed by our deep-learning model. We believe that our results will promote the application of similar quantum optical coherence tomography strategies to real scenarios.
High-temporal-resolution X-ray spectroscopy with free-electron and optical lasers
Authors: Rivas Daniel E. , Serkez Svitozar , Baumann Thomas M. , Boll Rebecca , Czwalinna Marie Kristin , Dold Simon , de Fanis Alberto , Gerasimova Natalia , Grychtol Patrik , Lautenschlager Björn , Lederer Maximilian , Jezynksi Tomasz , Kane Daniel , Mazza Tommaso , Meier Joachim , Müller Jost , Pallas Florent , Rompotis Dimitrios , Schmidt Philipp , Schulz Sebastian , Usenko Sergey , Venkatesan Sandhya , Wang Jinxiong , Meyer Michael
Published: March 2022

Ultrafast X-ray spectroscopies require flexible X-ray properties together with high temporal and spectral resolution. Here, we demonstrate simultaneous sub-20 fs and sub-eV resolutions for pump/probe experiments, without the need for additional photon arrival-time monitors.
Soliton frequency comb generation in CMOS-compatible silicon nitride microresonators
Authors: Xie Yaozu , Li Jiaqi , Zhang Yanfeng , Wu Zeru , Zeng Shihao , Lin Shuqing , Wu Zhaoyang , Zhou Wenchao , Chen Yujie , Yu Siyuan
Published: March 2022

The monolithic integration of soliton microcomb devices with active photonic components and high-frequency electronics is highly desirable for practical applications. Among many materials, silicon nitride (

SiN

x

) waveguide layers prepared by low-pressure chemical vapor deposition (LPCVD) have been the main platform for on-chip optical frequency comb generation. However, the high temperatures involved in LPCVD render it incompatible as a back-end process with complementary metal oxide semiconductor (CMOS) or active III-V compound semiconductor fabrication flows. We report the generation of coherent soliton frequency combs in micro-ring resonators fabricated in deuterated silicon nitride (

SiN

x

:
D

) waveguides with a loss of 0.09 dB/cm. Deposited at 270°C by an inductance-coupled plasma chemical vapor deposition (ICP-CVD) process, the material preparation and fabrication flow are fully CMOS-compatible. These results enable the integration of silicon-nitride-based optical combs and photonic integrated circuits (PICs) on prefabricated CMOS and/or III-V substrates, therefore marking a major step forward in

SiN

x

photonic technologies.
Assessment of lifestyle changes during coronavirus disease 2019 pandemic in Gondar town, Northwest Ethiopia
Authors: Kifle Zemene Demelash , Woldeyohanins Alem Endeshaw , Asmare Biniyam , Atanaw Birhanu , Mesafint Tigist , Adugna Meaza
Published: March 2022

Background

Coronavirus disease 2019 has had a global effect on people’s lifestyles. Many people have developed irregular eating patterns and become physically inactive, which leads to an aggravation of lifestyle-related diseases and unhealthier lifestyles; these, subsequently raise the severity of coronavirus disease 2019. This study aimed to assess lifestyle changes during coronavirus disease 2019 pandemic in Gondar town, North West, Ethiopia.

Method

Community-based cross-sectional study design was conducted among households at Gondar town from June to August 2021. The study participants were selected by a systematic random sampling technique from proportionally allocated kebeles. Data were collected using face-to-face interview techniques and were entered and analyzed by using a statistical package for the social sciences version 24; P-values < 0.05 were considered as statistically significant.

Result

Overall, 348 study participants were included in the study. Among those respondents, 52.3% (182) were female study participants and the mean age of the respondents was 30.95±14.4. In this study, there was a significant decrement in non-homemade food from 20.4% to 13.4% at (P = <0.001). Concerning water intake, 11.5% (40) of respondents consumed ≥8 cups/day before the coronavirus disease 2019 pandemic, and the percentage increased to 14.7% (51) during the coronavirus disease 2019 pandemic (p = 0.01). Of the participants, 46% participants were reported never engaging in any physical activity before the coronavirus pandemic, and the percentage decreased to 29.9% during the pandemic (P = 0.002). The respondents also exhibited increment tension in large from 4.9% to 22.7% before and during the coronavirus disease 2019 pandemic, respectively. Furthermore, about 6.3% of the study participants slept badly before the coronavirus disease 2019 pandemics and the effects of sleeping badly and restlessly increased to 25.9% during the coronavirus disease 2019 pandemic (P = <0.001).

Conclusion

The current study demonstrates that there is a noticeable alteration in food consumption, food choices, regular mealtime, sleeping habits, mental exhaustion, and practice of physical activity.
Internalizing symptoms and family functioning predict adolescent depressive symptoms during COVID-19: A longitudinal study in a community sample
Authors: Vacaru Stefania V. , Beijers Roseriet , de Weerth Carolina
Published: March 2022

Background

The COVID-19 pandemic and lockdown pose a threat for adolescents’ mental health, especially for those with an earlier vulnerability. Accordingly, these adolescents may need increased support from family and friends. This study investigated whether family functioning and peer connectedness protects adolescents with earlier internalizing or externalizing symptoms from increased depressive symptoms during the first Dutch COVID-19 lockdown in a low-risk community sample.

Methods

This sample comprised 115 adolescents (Mage= 13.06; 44% girls) and their parents (N= 111) and is part of an ongoing prospective study on child development. Internalizing and externalizing symptoms were self-reported a year before the COVID-19 lockdown. In an online survey during the first Dutch lockdown (April-May 2020), adolescents reported depressive symptoms and perceived peer connectedness, and parents reported family functioning.

Results

Twenty-four percent of adolescents reported clinically relevant symptoms of depression during the first COVID-19 lockdown. Depressive symptoms were significantly predicted by earlier internalizing, but not externalizing symptoms. Furthermore, higher quality of family functioning, but not peer connectedness, predicted fewer adolescent depressive symptoms. Family functioning and peer connectedness did not moderate the link between pre-existing internalizing symptoms and later depressive symptoms.

Conclusions

In a low-risk community sample, one-in-four adolescents reported clinically relevant depressive symptoms at the first COVID-19 lockdown. Higher earlier internalizing symptoms and lower quality of family functioning increased risks. These results indicate that even in low-risk samples, a substantial group of adolescents and their families are vulnerable during times of crisis.
Small business managers and Covid-19—The role of a sense of coherence and general resistance resources in coping with stressors
Authors: Hansson Josefine , Landstad Bodil J. , Vinberg Stig , Hedlund Marianne , Tjulin Åsa
Published: March 2022

Background

The response of small business managers to an external event such as the pandemic can have a profound effect on the work environment, health and well-being for themselves and their employees. Previous research on small business managers during the pandemic has mainly focused on traditional pathogenic effects, and there is a lack of studies looking at the issue from a salutogenic health promotion perspective. The aim of this study is to explore whether a sense of coherence and general resistance resources were experienced by small business managers in Sweden and Norway during the Covid-19 pandemic.

Methods

A qualitative design was applied through exploratory interviews with 16 managers of small businesses in Sweden and Norway. A content analysis of the interviews was conducted using the sense of coherence concept by Aaron Antonovsky, with the three main components of comprehensibility, meaningfulness and manageability acting as a conceptual framework for the analysis process.

Results

Within the three main sense-of-coherence categories, six general resistance resources were identified as being important for the managers to handle uncertainty during the pandemic. These were understanding rules and regulations, social support, optimism, proactivity, problem-solving and flexibility and cooperation.

Conclusions

The small business managers handled the pandemic in a way that worked well in their contexts, and the pandemic generally did not have a negative effect on their businesses or themselves. A salutogenic approach, through which the managers focused on identifying and using resources, was an important factor for managing stressors and adversity during the pandemic. Hence, the concept of salutogenesis may be used as an intervention to foster better health in small businesses, both at a personal and organisational level in order to handle future challenges effectively.
Association between outdoor temperature and achilles tendon repair: A 14-years nationwide population-based cohort study
Authors: Park Kwang Hwan , Park Jae Han , Yoon Yeo Kwon , Kwon Jai Bum , Kim Jung Hwan , Lee Eunju , Roh Yunho , Han Seung Hwan , Lee Jin Woo
Published: March 2022

The incidence of achilles tendon rupture varies by gender, age, and seasonal variation. However, there has been no study as yet linking achilles tendon rupture to daily fluctuations in outdoor temperature. The purpose of this study was to investigate the association between outdoor temperature and achilles tendon rupture using a Korea Meteorological Administration database and a Korean National Health Insurance Service-National Sample Cohort database. Between 2002 and 2015, all instances of achilles tendon repair were retrieved from the National Health Insurance Service-National Sample Cohort database to examine sociodemographic factors, specifically sex, age, residential area, and income level. Minimum age requirement was 20 years. Outdoor temperatures recorded at 16 observation points in South Korea were also acquired from the Korea Meteorological Administration data center for analysis. Overall, 850 (0.119%) of 713,456 individuals in the National Health Insurance Service-National Sample Cohort database underwent achilles tendon repair between 2002 and 2015. Yearly procedural totals increased with advancing age, peaking at ages 30–39 years (14.6 per 100,000 persons) and declining thereafter. Minimum, median, and maximum outdoor temperatures were associated with achilles tendon repair (p<0.05), as did household income. In multivariate logistic regression analysis, outdoor temperatures, sex, age, and household income emerged as factors significantly associated with achilles tendon repair. Outcomes of this study confirm an association between incidence of achilles tendon repair and outdoor temperature, the latter denoting a novel index and likely surrogate measure of vigorous physical activity afforded by warmer weather.
New heat-treated vs electropolished nickel-titanium instruments used in root canal treatment: Influence of autoclave sterilization on surface roughness
Authors: Almohareb Rahaf A. , Barakat Reem , Albohairy Fatimah
Published: March 2022

Nickel-titanium (NiTi) instruments used to treat root canal infections are affected by autoclave sterilization in various ways. The aim of this study was to compare the effect of autoclave sterilization on two NiTi rotary instruments that undergo different manufacturing treatments: The electro-polished Race and the heat-treated Race Evo, using scanning electron microscope analysis. In this in-vitro study, Race and Race-Evo instruments were subjected to a number of autoclaving cycles (0, 1, 3, 5, and 10). Scanning electron microscopy images were obtained at 3 mm from the tip of the file at 450x and 1000x magnifications. Surface roughness parameters were measured using ImageJ software. The results showed that autoclave sterilization caused a significant decrease in conventional NiTi Race surface roughness. While in Race Evo, surface roughness increased following the first autoclaving cycle. After 10 autoclaving cycles, surface roughness significantly decreased for both Race and Race Evo files.
The cardiac autonomic response to acute psychological stress in type 2 diabetes
Authors: Monzer Nelly Lou , Hartmann Mechthild , Buckert Magdalena , Wolff Kira , Nawroth Peter , Kopf Stefan , Kender Zoltan , Friederich Hans-Christoph , Wild Beate
Published: March 2022

Background

Impaired cardiac autonomic control is common among people with type 2 diabetes. The autonomic nervous system and its regulatory influence on the cardiovascular system also play a key role in the physiological response to psychosocial stressors. It is unclear whether the disease-related impairment of cardiac autonomic control in people with type 2 diabetes affects the stress response. The aim of this study was therefore to examine the cardiac autonomic and the psychological stress response of people with type 2 diabetes compared to healthy control participants.

Methods

We used the trier social stress test to induce stress in n = 51 participants with type 2 diabetes and n = 47 healthy controls. We assessed heart rate (HR) and heart rate variability (HRV) using six ECG samples before, during and after the stress test. We measured participants’ psychological stress response using visual analogue scales.

Results

Longitudinal multilevel models showed an attenuated HR increase in response to the stress test combined with a slower HR recovery after the stress test, in people with type 2 diabetes. This pattern was accompanied by significantly lower low frequency HRV but no differences in high frequency HRV between the groups. Additionally, people with type 2 diabetes showed an increased level of self-reported psychological tension 45 minutes after the stress test.

Conclusions

The impairment of the autonomic nervous system found in people with type 2 diabetes is reflected in the HR response to stress—but not in the HRV response—and partially mirrored in the psychological stress response. Our results underline the importance of considering the interplay of psychosocial stress and disease-related changes in the physiological stress response system in research and treatment of type 2 diabetes.
Carnivores and their prey in Sumatra: Occupancy and activity in human-dominated forests
Authors: Widodo Febri Anggriawan , Imron Muhammad Ali , Sunarto Sunarto , Giordano Anthony J.
Published: March 2022

Understanding the effect of anthropogenic disturbance, and its interaction with carnivores and their prey, is crucial to support the conservation of threatened carnivores, particularly in rapidly changing landscapes. Based on systematic camera-trap sampling of four protected areas in Riau Province of central Sumatra, we assessed the habitat occupancy and spatiotemporal overlap between people, potential carnivore prey, and four threatened species of medium-sized or large carnivores: Sumatran tigers (Panthera tigris sumatrae), Malayan sun bears (Helarctos malayanus), dholes (Cuon alpinus), and Sunda clouded leopards (Neofelis diardi). To assess spatial overlap of target species, we used single-species occupancy models and applied a Species Interaction Factor (SIF) to conditional two-species occupancy models. We also used kernel density estimation (KDE) to assess temporal overlap among these species. Our habitat use models showed that altitude (elevation) strongly influenced the occupancy of all large carnivores and potential prey species. Except for Sunda clouded leopards, the occurrence of large carnivore species was positively related to the spatial co-occurrence of humans (SIF > 1). In addition, we found that sun bears and dholes both exhibited high spatial overlap with tigers, and that sun bears alone exhibited high temporal overlap with people. Our findings contribute to an improved understanding of the contemporary ecology of carnivores and their prey in rapidly changing, southeast Asian landscapes. Such knowledge is important to the conservation and recovery of large carnivores in conservation hotspots that are increasingly dominated by humans across Sumatra, as well as globally.
The shame spiral of addiction: Negative self-conscious emotion and substance use
Authors: Batchelder Abigail W. , Glynn Tiffany R. , Moskowitz Judith T. , Neilands Torsten B. , Dilworth Samantha , Rodriguez Sara L. , Carrico Adam W.
Published: March 2022

Background

The bidirectional associations between negative self-conscious emotions such as shame and guilt and substance use are poorly understood. Longitudinal research is needed to examine the causes, consequences, and moderators of negative self-conscious emotions in people who use substances.

Methods

Using parallel process latent growth curve modeling, we assessed bidirectional associations between shame and guilt and substance use (i.e., number of days in the past 30 used stimulants, alcohol to intoxication, other substances, or injected drugs) as well as the moderating role of positive emotion. Emotions were assessed using the Differential Emotions Scale. The sample included 110 sexual minority cisgender men with biologically confirmed recent methamphetamine use, enrolled in a randomized controlled trial in San Francisco, CA. Participants self-reported emotions and recent substance use behaviors over six time points across 15 months.

Results

Higher initial levels of shame were associated with slower decreases in stimulant use over time (b= 0.23,p= .041) and guilt was positively associated with stimulant use over time (β = 0.85,p< .0001). Initial levels of guilt and alcohol use were positively related (b= 0.29,p= .040), but over time, they had a negative relationship (β = -0.99,p< .0001). Additionally, higher initial levels of other drug use were associated with slower decreases in shame over time (b= 0.02,p= .041). All results were independent of depression, highlighting the specific role of self-conscious emotions.

Conclusions

Shame and guilt are barriers to reducing stimulant use, and expanded efforts are needed to mitigate the deleterious effects of these self-conscious emotions in recovery from a stimulant use disorder.
The effects of exercise training on autonomic and hemodynamic responses to muscle metaboreflex in people living with HIV/AIDS: A randomized clinical trial protocol
Authors: Gama Gabriel , dos Santos Rangel Marcus Vinicius , de Oliveira Coelho Vanessa Cunha , Paz Gabriela Andrade , de Matos Catarina Vieira Branco , Silva Bárbara Pinheiro , Lopes Gabriella de Oliveira , Lopes Karynne Grutter , Farinatti Paulo , Borges Juliana Pereira
Published: March 2022

Background

People living with HIV (PLHIV) present impaired muscle metaboreflex, which may lead to exercise intolerance and increased cardiovascular risk. The muscle metaboreflex adaptations to exercise training in these patients are unknown. The present study aims to investigate the effects of a supervised multimodal exercise training on hemodynamic and autonomic responses to muscle metaboreflex activation in PLHIV.

Methods and design

In this randomized clinical trial protocol, 42 PLHIV aged 30–50 years will be randomly assigned at a ratio of 1:1 into an intervention or a control group. The intervention group will perform exercise training (3x/week during 12 weeks) and the control group will remain physically inactive. A reference group composed of 21 HIV-uninfected individuals will be included. Primary outcomes will be blood pressure and heart rate variability indices assessed during resting, mental stress, and activation of muscle metaboreflex by a digital sphygmomanometer and a heart rate monitor; respectively. Mental stress will be induced by the Stroop Color-Word test and muscle metaboreflex will be activated through a post-exercise circulatory arrest (PECA) protocol, being the latter performed without and with the application of a capsaicin-based analgesic balm in the exercised limb. Secondary outcomes will be heart rate, peripheral vascular resistance, stroke volume, cardiac output, blood lactate, anthropometric markers and handgrip maximal voluntary contraction. The intervention and control groups of PLHIV will be evaluated at baseline and after the intervention, while the HIV-uninfected reference group only at baseline.

Discussion

The findings of the present study may help to elucidate the muscle metaboreflex adaptations to exercise training in PLHIV.

Trial registration

This study will be performed at University of Rio de Janeiro State following registration at ClinicalTrials.gov asNCT04512456on August 13, 2020.
The effect of variations in CT scan protocol on femoral finite element failure load assessment using phantomless calibration
Authors: Ataei Ali , Eikhout Jelle , van Leeuwen Ruud G. H. , Tanck Esther , Eggermont Florieke
Published: March 2022

Recently, it was shown that fracture risk assessment in patients with femoral bone metastases using Finite Element (FE) modeling can be performed using a calibration phantom or air-fat-muscle calibration and that non-patient-specific calibration was less favorable. The purpose of this study was to investigate if phantomless calibration can be used instead of phantom calibration when different CT protocols are used. Differences in effect of CT protocols on Hounsfield units (HU), calculated bone mineral density (BMD) and FE failure loads between phantom and two methods of phantomless calibrations were studied. Five human cadaver lower limbs were scanned atop a calibration phantom according to a standard scanning protocol and seven additional commonly deviating protocols including current, peak kilovoltage (kVp), slice thickness, rotation time, field of view, reconstruction kernel, and reconstruction algorithm. The HUs of the scans were calibrated to BMD (in mg/cm3) using the calibration phantom as well as using air-fat-muscle and non-patient-specific calibration, resulting in three models for each scan. FE models were created, and failure loads were calculated by simulating an axial load on the femur. HU, calculated BMD and failure load of all protocols were compared between the three calibration methods. The different protocols showed little variation in HU, BMD and failure load. However, compared to phantom calibration, changing the kVp resulted in a relatively large decrease of approximately 10% in mean HU and BMD of the trabecular and cortical region of interest (ROI), resulting in a 13.8% and 13.4% lower failure load when air-fat-muscle and non-patient-specific calibrations were used, respectively. In conclusion, while we observed significant correlations between air-fat-muscle calibration and phantom calibration as well as between non-patient-specific calibration and phantom calibration, our sample size was too small to prove that either of these calibration approaches was superior. Further studies are necessary to test whether air-fat-muscle or non-patient-specific calibration could replace phantom calibration in case of different scanning protocols.
Advancing the study of solving linear equations with negative pronumerals: A smarter way from a cognitive load perspective
Authors: Ngu Bing H. , Phan Huy P.
Published: March 2022

Central to cognitive load theory is the concept of element interactivity, which reflects the complexity of material. The complexity of linear equations depends on the number of operational and relational lines and the nature of the operation (balance versus inverse) in the solution procedure. A relational line refers to the quantitative relation whereby the right-hand side of the equation equals to its left-hand side. An operational line refers to the application of an operation and such a procedural step preserves the equality of the linear equation. The balance method and inverse method differ in the operational line (e.g., + 3 on both sides vs.– 3 becomes + 3) where the inverse operation imposes half the level of element interactivity as the balance method. Seventy-five students randomly assigned to either the balance group or inverse group to complete (i) one-step equations (Experiment 1), (ii) two-step equations (Experiment 2), and (iii) one-step and two-step equations with a focus on equations with negative pronumerals (Experiment 3). Performance favoured the inverse group when the gap between the low and high element interactivity equations was substantial enough. Both groups performed better and invested lower mental effort on the inverse operation than the balance operation.
A Bayesian network meta-analysis of the primary definitive therapies for locoregionally advanced nasopharyngeal carcinoma: IC+CCRT, CCRT+AC, and CCRT alone
Authors: Zhang Zhan-Jie , Shi Liang-Liang , Hong Xiao-Hua , Xiao Bo-Ya , Lin Guo-He , Liu Quentin , Wang Bi-Cheng
Published: March 2022

Background

The major aim of this Bayesian network analysis was to determine the optimal treatment strategy for locoregionally advanced nasopharyngeal carcinoma (LANPC).

Method

We systematically searched databases and extracted data from randomized clinical trials involving LANPC patients randomly assigned to receive induction chemotherapy followed by concurrent chemoradiotherapy (IC+CCRT), CCRT followed by adjuvant chemotherapy (CCRT+AC), or CCRT.

Results

In the network analysis, IC+CCRT was significantly better than CCRT alone for 5-year FFS (odds ratio [OR]: 1.63, 95% credible interval [CrI] 1.16–2.29), DMFS (OR: 1.56, 95% CrI 1.08–2.22), and LFRS (OR: 1.62, 95% CrI 1.02–2.59), but not OS (OR: 1.35, 95% CrI 0.92–2.00). Rank probabilities showed that IC+CCRT was ranked the best followed by CCRT+AC and CCRT for all 5-year outcomes. Although compared to IC+CCRT and CCRT, CCRT+AC did not significantly improve survival but had the highest 5-year survival rates.

Conclusions

IC+CCRT could be recommended as a front-preferred primary definitive therapy for patients with LANPC.
Nanoencapsulation of buriti oil (Mauritia flexuosa L.f.) in porcine gelatin enhances the antioxidant potential and improves the effect on the antibiotic activity modulation
Authors: Morais Neyna de Santos , Passos Thaís Souza , Ramos Gabriela Rocha , Ferreira Victoria Azevedo Freire , Moreira Susana Margarida Gomes , Chaves Filho Gildácio Pereira , Barreto Ana Paula Gomes , Leite Pedro Ivo Palacio , Almeida Ray Silva de , Paulo Cícera Laura Roque , Fernandes Rafael , Silva Sebastião Ânderson Dantas da , Nascimento Sara Sayonara da Cruz , de Sousa Júnior Francisco Canindé , de Assis Cristiane Fernandes
Published: March 2022

The present study evaluated the cytotoxicity, antioxidant potential, and antimicrobial effect on the antibiotic activity modulation of gelatin nanoparticles containing buriti oil (OPG). The cytotoxicity analysis was performed on Chinese Hamster Ovary Cells (CHO) using a MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test. The antioxidant potential of buriti oil and OPG was determined by total antioxidant capacity, reducing power, and the ABTS (2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) test. The modulating antimicrobial activity was evaluated by determining the minimum inhibitory concentration (MIC) concentration against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, gentamicin and norflaxacillin. The nanoformulation of OPG did not show a cytotoxic effect on CHO cells and had a higher antioxidant potential than free buriti oil (p<0.05). The combination of antibiotics with free buriti oil and OPG was more efficient in inhibiting E. coli and P. aeruginosa than isolated norfloxacillin and gentamicin (p<0.05). Regarding the inhibition of S. aureus, OPG in combination with norfloxacillin reduced MIC by 50%. Nanoencapsulation was a viable alternative to enhance functionality and adding commercial value to buriti oil.