bluuebunny/crossref_metadata_2025 huggingface dataset:
Paraxial equivalent of the gradient-index lens of the human eye
Authors: Manns Fabrice , Ho Arthur
Published: August 2022

The lens of the eye has a refractive index gradient that changes as the lens grows throughout life. These changes play a key role in the optics of the eye. Yet, the lens is generally simulated using a homogeneous model with an equivalent index that does not accurately represent the gradient. We present an analytical paraxial model of the gradient lens of the eye that gives the direct relation between refractive index distribution and paraxial characteristics. The model accurately simulates the changes in lens power with age and accommodation. It predicts that a decrease in equivalent index with age is associated with a flattening of the axial refractive index profile and that changes in lens power with accommodation are due primarily to changes in the axial variation of the iso-indicial curvature, consistent with Gullstrand’s intracapsular theory of accommodation. The iso-indicial curvature gradient causes a shift of the principal planes compared to the homogeneous equivalent model. This shift introduces a clinically significant error in eye models that implement a homogenous lens. Our gradient lens model can be used in eye models to better predict the optics of the eye and the changes with age and accommodation.
Opto-ultrasound biosensor for wearable and mobile devices: realization with a transparent ultrasound transducer
Authors: Park Jeongwoo , Park Byullee , Ahn Joongho , Kim Donggyu , Kim Jin Young , Kim Hyung Ham , Kim Chulhong
Published: August 2022

Mobile and wearable healthcare electronics are widely used for measuring bio-signals using various fusion sensors that employ photoplethysmograms, cameras, microphones, ultrasound (US) sensors, and accelerometers. However, the consumer demand for small form factors has significantly increased as the integration of multiple sensors is difficult in small mobile or wearable devices. This study proposes two novel opto-US sensors, namely (1) a wearable photoplethysmography (PPG)-US device and (2) a PPG sensor built-in mobile smartphone with a US sensor, seamlessly integrated using a transparent ultrasound transducer (TUT). The TUT exhibits a center frequency of 6 MHz with a 50% bandwidth and 82% optical transparency in visible and near-infrared regions. We developed an integrated wearable PPG-US device to demonstrate its feasibility and coupled the TUT sensor with a smartphone. We measured the heart rates optically and acoustically in human subjects and quantified the oxygen saturation optically by passing light through the TUT. The proposed proof-of-concept is a novel sensor fusion for mobile and wearable devices that require a small form factor and aim to improve digital healthcare. The results of this study can form the basis for innovative developments in sensor-based high-tech industrial applications, such as automobiles, robots, and drones, in addition to healthcare applications.
Analyzing and measuring the diode laser’s linewidth affected by the driving current’s white noise
Authors: Lu Feifei , Hou Xiaokai , Wang Xin , Guo Miao , Chang Rui , He Jun , Wang Junmin
Published: August 2022

It is important to study the effect of injection current’s noise on the diode laser’s linewidth. In this paper, the effect of the white noise applied to the injection current on the linewidth of diode laser is investigated theoretically and experimentally. Theoretically, by adding the non-Markov noise term into the Langevin equation, the output laser’s linewidth of the diode laser with the white noise current is obtained. In experiment, an optical Fabry–Perot (F–P) cavity with a linewidth of

∼

1.83

M
H
z

and a finesse of

∼

136

is employed to measure a 1560.5 nm distributed-feedback (DFB)-type diode laser’s linewidth. With an increase of the white noise intensity, the laser linewidth is broadened from

∼

2

to

∼

60

M
H
z

gradually, and the line shape is characterized evolving from Lorentzian function to Gaussian function. At the same level of white noise intensity, the laser linewidth decreases with increase of the injection current. The accuracy of our measurements is verified based on the fiber-delayed and acousto-optic modulator (AOM)-shifted self-heterodyne scheme and the optical F–P cavity linewidth measurement method. The 1560.5 nm laser is boosted by using an erbium-doped fiber amplifier (EDFA) and is frequency doubled to 780.25 nm by a fiber-pigtailed, single-pass PPMgO:LN waveguide module, and the laser linewidth is visually observed and verified by broadening of the saturated absorption spectra of rubidium atoms. Clearly this linewidth manipulation method of diode lasers based on broadband white noise current coupling can be extended to other wavelength diode lasers and can be applied to laser measurement, laser communication, and other fields for different requirements.
Method for 10 Gbps near-ground quasi-static free-space laser transmission by nutation mutual coupling
Authors: Zhang Lei , Yu Xiaonan , Zhao Baiqiu , Wang Tong , Tong Shoufeng
Published: August 2022

This study proposes a method to reduce link loss in near-ground space laser communication with fiber-nutation-based mutual coupling. We designed a transmit-receive coaxial laser terminal with a 50 mm aperture and implemented beam acquisition tracking and nutation coupling using a single-detector and single-actuator. Following an indoor experiment and a 1 km field test, the single-ended nutation coupling and the two-way nutation mutual coupling theories were compared and analyzed. In conclusion, the proposed method could significantly increase the reception efficiency by ∼8 dB. The bit error rate of 10 Gbps pseudo-random code transmission was 2.478E-9. We also demonstrated video transmission.
AMCC nonlinear baseband superimposition and extraction aided by proposed interference cancellation for WDM-PON used in 5G mobile fronthaul
Authors: Guo Haipeng , Yang Chuanchuan , Gao Yunfeng , Li Hongbin
Published: August 2022

As the demand for mobile Internet capacity explodes, the research on fifth-generation (5G) mobile communication systems has gradually deepened, which has stringent requirements for latency and transmission capacity, especially in the section called mobile fronthaul (MFH). Wavelength division multiplexing passive optical network (WDM-PON) is an attractive technology for 5G MFH which requires an auxiliary management and control channel (AMCC) to achieve efficient network deployment. In previous studies, more research has been done on AMCC superimposition methods and transmission performance on 10 Gbps WDN-PON systems, and the role of AMCC in wavelength management has been studied at the system level. In this paper, we realize non-linear baseband modulation of AMCC signals up to 20 Mbps in a single wavelength 25-Gbps PON system through the distributed feed-back laser and Mach-Zehnder modulator. At the receiving end, we propose a low-complexity interference cancellation method to suppress the interference caused by WDM-PON signals and significantly reduce the bit error rate of AMCC signals. The method realizes a simplified scheme to reconstruct the PON signals by analyzing the characteristics of nonlinear modulation and the reconstructed signals can be applied to the original AMCC signals through filtering and subtraction to eliminate interference. These operations have low complexity and can be easily implemented by analog circuits, thus making it an effective way to improve the quality of AMCC signals. With the help of the proposed method, AMCC transmission at 20 Mbps can be achieved with different modulation depths, which is very promising for 5G MFH.
Broadband dual-channel channelizer based on a microwave photonic power tunable image rejection down-conversion
Authors: Yang Jiasi , Zheng Zhennan , Bai Yunping , Xue Hanxiao , Su Zhonghan , Ma Jingcan , Song Xiyao , Gao Xinlu , Zhao Xinchao , Huang Shanguo
Published: August 2022

Radiofrequency (RF) channelization has potential high frequency and wideband advantages in frequency-domain channel segmentation and down-conversion reception. In this paper, we propose a compact dual-channel channelizer that can process high-frequency wideband signals. It uses double-polarization double-sideband electro-optic modulation and Hartley structure photoelectric conversion to realize down-conversion channelization of the high-frequency wideband signal. The power matching between two polarization signals can be realized by controlling the modulator bias, so the crosstalk between the two output signals can be suppressed. The proposed channelizer has a compact structure since the electro-optic modulation is based on one single laser and one single integrated modulator. No filters are used in the structure, contributing to a very wide RF operation bandwidth and low constraints of laser wavelength. In the experiment, the single frequency signal pairs from 9 GHz to 15 GHz can achieve an inter-channel image rejection ratio of 53 dB. Furthermore, the channelizer slices multi-octave bandwidth quadrature phase shift keying (QPSK) signals up to 16 GHz with the wideband isolation higher than 10 dB and outputs them to two channels in parallel. The error vector magnitudes (EVM) of 9–17 GHz and 18–26 GHz band QPSK signals are guaranteed to be under 23.58% after channelized separation. To the best of our knowledge, the proposed channelizer provides high inter-channel interference suppression at dual-band adjacent signals with 8 GHz bandwidth for the first time. Therefore, the proposed channelizer has great application value for the reception and processing of millimeter signals in the future.
Realization of efficient 3D tapered waveguide-to-fiber couplers on a nanophotonic circuit
Authors: Chang Tzu-Han , Zhou Xinchao , Tamura Hikaru , Hung Chen-Lung
Published: August 2022

We report the realization of efficiently coupled 3D tapered waveguide-to-fiber couplers (TWCs) based on standard lithography techniques. The 3D TWC design is capable of achieving highly efficient flat-cleaved fiber to silicon nitride photonic waveguide coupling, with T ≈ 95 % polarization-insensitive coupling efficiency, wide bandwidth, and good misalignment tolerance. Our fabricated 3D TWCs on a functional nanophotonic circuit achieve T ≈ 85% coupling efficiency. Beyond applications in high-efficiency photon coupling, the demonstrated 3D lithography technique provides a complementary approach for mode field shaping and effective refractive index engineering, potentially useful for general applications in integrated photonic circuits.
Clamp-type quartz tuning fork enhanced photoacoustic spectroscopy
Authors: Wu Qian , Lv Haohua , Lin Leqing , Wu Hongpeng , Giglio Marilena , Zhu Wenguo , Zhong Yongchun , Sampaolo Angelo , Patimisco Pietro , Dong Lei , Spagnolo Vincenzo , Yu Jianhui , Zheng Huadan
Published: August 2022

In this Letter, clamp-type quartz tuning fork enhanced photoacoustic spectroscopy (Clamp-type QEPAS) is proposed and realized through the design, realization, and testing of clamp-type quartz tuning forks (QTFs) for photoacoustic gas sensing. The clamp-type QTF provides a wavefront-shaped aperture with a diameter up to 1 mm, while keeping Q factors > 104. This novel, to the best of our knowledge, design results in a more than ten times increase in the area available for laser beam focusing for the QEPAS technique with respect to a standard QTF. The wavefront-shaped clamp-type prongs effectively improve the acoustic wave coupling efficiency. The possibility to implement a micro-resonator system for clamp-type QTF is also investigated. A signal-to-noise enhancement of ∼30 times has been obtained with a single-tube acoustic micro resonator length of 8 mm, ∼20% shorter than the dual-tube micro-resonator employed in a conventional QEPAS system.
High-performance waveguide-coupled lateral Ge/Si avalanche photodetector
Authors: Pang Yaqing , Liu Zhi , Zhu Yupeng , liu Xiangquan , Zhang Diandian , Niu Chaoqun , Li Mingming , Zheng Jun , zuo Yuhua , Cheng Buwen
Published: August 2022

A high-performance waveguide-coupled lateral avalanche photodetector (APD) is experimentally demonstrated without silicon epitaxy and charge layer ion implantation. At the wavelength of 1550 nm, it shows a high responsivity of 48 A/W and a gain-bandwidth product (GBP) of 360 GHz. Wide-open eye diagrams at 25 Gbps can be observed at various avalanche gains. These outstanding performances indicate the proposed APD has great potential in high-speed optical transceivers for optical links.
Measurement of the coherence-orbital angular momentum matrix of a partially coherent beam
Authors: Yang Zhaohui , Wang Haiyun , Chen Yahong , Wang Fei , Gbur Greg , Korotkova Olga , Cai Yangjian
Published: August 2022

The recently introduced coherence-orbital angular momentum (COAM) matrix of a partially coherent beam [Phys. Rev. A 103, 023529 (2021)10.1103/PhysRevA.103.023529] is experimentally measured for the first time, to the best of our knowledge. The new methodology based on Young’s interference experiment with a pair of ring-shaped slits with embedded spiral phases is thoroughly described. By introducing the phase shift of 0 and π / 2 between two ring slits, the real and imaginary parts of the elements of the COAM matrix are obtained by measuring the on-axis spectral density in the far field of the double-ring slit. We validate our protocol through measuring the COAM matrix of an elliptical Gaussian Schell-model (GSM) beam which reveals the existence of non-trivial correlations between modes with different topological indices. The experimental results agree reasonably well with the theoretical predictions.
Signal neutrality, scalar property, and collapsing boundaries as consequences of a learned multi-timescale strategy
Authors: Manneschi Luca , Gigante Guido , Vasilaki Eleni , Del Giudice Paolo
Published: August 2022

We postulate that three fundamental elements underlie a decision making process: perception of time passing, information processing in multiple timescales and reward maximisation. We build a simple reinforcement learning agent upon these principles that we train on a random dot-like task. Our results, similar to the experimental data, demonstrate three emerging signatures. (1) signal neutrality: insensitivity to the signal coherence in the interval preceding the decision. (2) Scalar property: the mean of the response times varies widely for different signal coherences, yet the shape of the distributions stays almost unchanged. (3) Collapsing boundaries: the “effective” decision-making boundary changes over time in a manner reminiscent of the theoretical optimal. Removing the perception of time or the multiple timescales from the model does not preserve the distinguishing signatures. Our results suggest an alternative explanation for signal neutrality. We propose that it is not part of motor planning. It is part of the decision-making process and emerges from information processing on multiple timescales.
Recruitment strategies and lessons learned from a large genetic study of African Americans
Authors: Salowe Rebecca J. , Lee Roy , Zenebe-Gete Selam , Vaughn Marquis , Gudiseva Harini V. , Pistilli Maxwell , Kikut Ava , Becker Emily , Collins David W. , He Jie , Merriam Sayaka , Mulvihill Kristen , Laberee Nora , Lomax-Reese Sara , Murphy Windell , Henderer Jeffrey , Chavali Venkata R. M. , Cui Qi N. , Ross Ahmara G. , Addis Victoria , Sankar Prithvi S. , Miller-Ellis Eydie , Maguire Maureen G. , O’Brien Joan M.
Published: August 2022

Genetic studies must enroll large numbers of participants to obtain adequate statistical power. Data are needed on how researchers can best use limited financial and practical resources to achieve these targets, especially in under-represented populations. This paper provides a retrospective analysis of the recruitment strategies for a large glaucoma genetics study in African Americans. The Primary Open-Angle African American Glaucoma Genetics study enrolled 10,192 African American subjects from the Philadelphia region. Major recruitment approaches included clinic enrollment from University of Pennsylvania (UPenn) sites, clinic enrollment from external sites, sampling of Penn Medicine Biobank (PMBB), and community outreach. We calculated the enrollment yield, cost per subject, and seasonal trends of these approaches. The majority (65%) of subject were enrolled from UPenn sites with an average cost of $133/subject. Over time, monthly case enrollment declined as the pool of eligible subjects was depleted. Expanding to external sites boosted case numbers ($129/subject) and the biobank provided additional controls at low cost ($5/subject), in large part due to the generosity of PMBB providing samples free of cost. Community outreach was costly with low return on enrollment ($978/subject for 220 subjects). Summer months (Jun-Aug) produced the highest recruitment yields (p<0.001). Genetic studies will benefit from a multi-pronged and culturally sensitive recruitment approach. In our experience, the biobank was most cost-effective for control enrollment, while recruitment from clinics (including expansion to new sites) was necessary to recruit fully phenotyped cases.
U.S. CDC support to international SARS-CoV-2 seroprevalence surveys, May 2020–February 2022
Authors: Ben Hamida Amen , Charles Myrna , Murrill Christopher , Henao Olga , Gallagher Kathleen
Published: August 2022

SARS-CoV-2 seroprevalence surveys provide critical information to assess the burden of COVID-19, describe population immunity, and guide public health strategies. Early in the pandemic, most of these surveys were conducted within high-income countries, leaving significant knowledge gaps in low-and middle-income (LMI) countries. To address this gap, the U.S. Centers for Disease Control and Prevention (CDC) is supporting serosurveys internationally. We conducted a descriptive analysis of international serosurveys supported by CDC during May 12, 2020–February 28, 2022, using an internal tracker including data on the type of assistance provided, study design, population surveyed, laboratory testing performed, and status of implementation. Since the beginning of the pandemic, CDC has supported 72 serosurveys (77 serosurvey rounds) in 35 LMI countries by providing technical assistance (TA) on epidemiologic, statistical, and laboratory methods, financial assistance (FA), or both. Among these serosurvey rounds, the majority (61%) received both TA and FA from CDC, 30% received TA only, 3% received only FA, and 5% were part of informal reviews. Fifty-four percent of these serosurveys target the general population, 13% sample pregnant women, 7% sample healthcare workers, 7% sample other special populations (internally displaced persons, patients, students, and people living with HIV), and 18% assess multiple or other populations. These studies are in different stages of implementation, ranging from protocol development to dissemination of results. They are conducted under the leadership of local governments, who have ownership over the data, in collaboration with international partners. Thirty-four surveys rounds have completed data collection. CDC TA and FA of SARS-CoV-2 seroprevalence surveys will enhance the knowledge of the COVID-19 pandemic in almost three dozen LMI countries. Support for these surveys should account for current limitations with interpreting results, focusing efforts on prospective cohorts, identifying, and forecasting disease patterns over time, and helping understand antibody kinetics and correlates of protection.
The COVID-19 pandemic and its impact on medical teaching in obstetrics and gynecology—A nationwide expert survey among teaching coordinators at German university hospitals
Authors: Riedel Maximilian , Amann Niklas , Recker Florian , Hennigs André , Heublein Sabine , Meyer Bastian , Karge Anne , Eisenkolb Gabriel , Lammert Jacqueline , Graf Anna , Klein Evelyn , Weiss Martin , Riedel Fabian
Published: August 2022

Purpose

The COVID-19 pandemic has imposed severe challenges on medical education at German university hospitals. In this first German nationwide expert survey, we addressed the responsible university teaching coordinators in obstetrics and gynecology departments and investigated their experiences during the pandemic as well as their opinions on future developments, especially with regard to the broader implementation of e-learning in the standard curriculum.

Methods

The questionnaire included 42 items and was disseminated among teaching coordinators at all 41 departments of obstetrics and gynecology at German university hospitals via an email that included a weblink to the online survey provider. Responses were collected between 19 April and 7 June 2021.

Results

In total, 30 responses were collected from 41 departments across Germany and their respective teaching coordinators in obstetrics and gynecology. The general opinion of the medical teaching provided during the pandemic was positive, whereas the teaching quality in practical skills was considered inferior and not equivalent to the standard face-to-face curriculum. Lectures and seminars had to be substituted by remote-learning alternatives, while clinical clerkships were reduced in length and provided less patient contact. Students in their final year experienced only a few differences in the clinical and teaching routine. Teaching coordinators in obstetrics and gynecology stated that they intend to incorporate more e-learning into the curriculum in the future.

Conclusion

The medical educators’ views presented here may help to complement the already-thoroughly investigated experiences of students under the restrictions of the COVID-19 pandemic. Medical educators in obstetrics and gynecology at German university hospitals have successfully established online and hybrid teaching alternatives to their standard face-to-face courses. Building on recent experiences, digitalization could help to improve future medical education.
Validation of the solution structure of dimerization domain of PRC1
Authors: Tan Fei , Xu Jin
Published: August 2022

Cell-cycle dependent proteins are indispensible for the accurate division of cells, a group of proteins called Microtubule-associated proteins (MAPs) are important to cell division as it bind microtubules and participate with other co-factors to form the spindle midbody, which works as the workhorse of cell-division. PRC1 is a distinguishing member of MAPs, as it is a human MAP and works as the key in mediating daughter cell segregation in ana-phase and telo-phase. The physiological significance of PRC1 calls for a high resolution three-dimensional structure. The crystal structure of PRC1 was published but has low resolution (>3 Å) and incomplete sidechains, placing hurdles to understanding the structure-function relationships of PRC1, therefore, we determined the high-resolution solution structure of PRC1’s dimerization domain using NMR spectroscopy. Significant differences between the crystal structure and the solution structure can be observed, the main differences center around the N terminus and the end of the alpha-Helix H2. Furthermore, detailed structure analyses revealed that the hydrophobic core packing of the solution and crystal structures are also different. To validate the solution structure, we used Hydrogen-deuterium exchange experiments that address the structural discrepancies between the crystal and solution structure; we also generated mutants that are key to the differences in the crystal and solution structures, measuring its structural or thermal stability by NMR spectroscopy and Fluorescence Thermal Shift Assays. These results suggest that N terminal residues are key to the integrity of the whole protein, and the solution structure of the dimerization domain better reflects the conformation PRC1 adopted in solution conditions.
Emergency provider perspectives on facilitators and barriers to home and community services for older adults with serious life limiting illness: A qualitative study
Authors: Hill Jacob D. , De Forcrand Claire , Cuthel Allison M. , Adeyemi Oluwaseun John , Shallcross Amanda J. , Grudzen Corita R.
Published: August 2022

Background

Older adults account for a large proportion of emergency department visits, but those with serious life-limiting illness may benefit most from referral to home and community services instead of hospitalization. We aim to document emergency provider perspectives on facilitators and barriers to accessing home and community services for older adults with serious life-limiting illness.

Methods

We conducted interviewer-administered semi-structured interviews with emergency providers from health systems across the United States to obtain provider perspectives on facilitators and barriers to accessing home and community services. We completed qualitative thematic analysis using an iterative process to develop themes and subthemes to summarize provider responses.

Results

We interviewed 8 emergency nurses and 10 emergency physicians across 11 health systems. Emergency providers were familiar with local home and community services. Facilitators to accessing these services include care management and social workers. Barriers include services that are not accessible full-time to receive referrals, insurance/payment, and the busy nature of the emergency department. The most helpful reported services were hospice, physical therapy, occupational therapy, and visiting nursing services. Home-based palliative care and full-time emergency department-based care management and social work were the services most desired by providers. Providers expressed support for improving access to home and community services in the hopes of decreasing unnecessary emergency visits and inpatient admissions, and to provide patients with greater options for supportive care.

Conclusion

Obtaining the perspective of emergency providers highlights important considerations to accessing HCS for older-adults with serious life-limiting illness from the emergency department. This study provides foundational information for futures studies and initiatives for improving access to home and community services directly from the emergency department.
Survival and complications after neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy for esophageal squamous cell cancer: A meta-analysis
Authors: Guo Yaru , Xu Mingna , Lou Yufei , Yuan Yan , Wu Yuling , Zhang Longzhen , Xin Yong , Zhou Fengjuan
Published: August 2022

Objectives

To compare the survival and complications of neoadjuvant chemoradiation (NCRT) versus neoadjuvant chemotherapy (NCT) for esophageal squamous cell carcinoma (ESCC).

Methods

We conducted a systematic literature search of the PubMed, Web of Science, Cochrane Library, EMBASE, CNKI, Wanfang Data, CBM, and VIP databases from inception to November 2021. Meta-analyses were performed using RevMan (version 5.3) and Stata version 15.0.

Results

A total of 18 studies were included, which involved 3137 patients, The results of the metaanalysis showed that the pathological complete remission rate (odds ratio [OR] = 5.21, 95% confidence interval [CI]: 2.85–9.50, p<0.00001) and complete tumor resection rate (OR = 2.31, 95% CI: 1.57–3.41, p<0.0001) in the NCRT group were significantly better than those in the NCT group. Our meta-analysis results showed that 1-, 3-, and 5-year survival rates (1-year overall survival [OS]: OR = 1.51, 95% CI: 1.11–2.05, p = 0.009; 3-year OS: OR = 1.73, 95% CI: 1.36–2.21, p<0.0001; 5-year OS: OR = 1.61, 95% CI: 1.30–1.99, p<0.00001) in the NCRT group were significantly higher than those in the NCT group. NCRT can lead a significant survival benefit compared with NCT and there was no significant difference between the two neoadjuvant treatments in terms of postoperative complications.

Conclusion

The use of NCRT in the treatment of patients with ESCC patients showed significant advantages in terms of survival and safety relative to the use of NCT.
Prediction of drug resistance by Sanger sequencing of Mycobacterium tuberculosis complex strains isolated from multidrug resistant tuberculosis suspect patients in Ethiopia
Authors: Mesfin Eyob Abera , Merker Matthias , Beyene Dereje , Tesfaye Abreham , Shuaib Yassir Adam , Addise Desalegn , Tessema Belay , Niemann Stefan
Published: August 2022

Background

Ethiopia is one of the high multidrug-resistant tuberculosis (MDR-TB) burden countries. However, phenotypic drug susceptibility testing can take several weeks due to the slow growth of Mycobacterium tuberculosis complex (MTBC) strains. In this study, we assessed the performance of a Sanger sequencing approach to predict resistance against five anti-tuberculosis drugs and the pattern of resistance mediating mutations.

Methods

We enrolled 226 MTBC culture-positive MDR-TB suspects and collected sputum specimens and socio-demographic and TB related data from each suspect between June 2015 and December 2016 in Addis Ababa, Ethiopia. Phenotypic drug susceptibility testing (pDST) for rifampicin, isoniazid, pyrazinamide, ethambutol, and streptomycin using BACTEC MGIT 960 was compared with the results of a Sanger sequencing analysis of seven resistance determining regions in the genes rpoB, katG, fabG-inhA, pncA, embB, rpsL, and rrs.

Result

DNA isolation for Sanger sequencing was successfully extracted from 92.5% (209/226) of the MTBC positive cultures, and the remaining 7.5% (17/226) strains were excluded from the final analysis. Based on pDST results, drug resistance proportions were as follows: isoniazid: 109/209 (52.2%), streptomycin: 93/209 (44.5%), rifampicin: 88/209 (42.1%), ethambutol: 74/209 (35.4%), and pyrazinamide: 69/209 (33.0%). Resistance against isoniazid was mainly mediated by the mutation katG S315T (97/209, 46.4%) and resistance against rifampicin by rpoB S531L (58/209, 27.8%). The dominating resistance-conferring mutations for ethambutol, streptomycin, and pyrazinamide affected codon 306 in embB (48/209, 21.1%), codon 88 in rpsL (43/209, 20.6%), and codon 65 in pncA (19/209, 9.1%), respectively. We observed a high agreement between phenotypic and genotypic DST, such as 89.9% (at 95% confidence interval [CI], 84.2%–95.8%) for isoniazid, 95.5% (95% CI, 91.2%–99.8%) for rifampicin, 98.6% (95% CI, 95.9–100%) for ethambutol, 91.3% (95% CI, 84.6–98.1%) for pyrazinamide and 57.0% (95% CI, 46.9%–67.1%) for streptomycin.

Conclusion

We detected canonical mutations implicated in resistance to rifampicin, isoniazid, pyrazinamide, ethambutol, and streptomycin. High agreement with phenotypic DST results for all drugs renders Sanger sequencing promising to be performed as a complementary measure to routine phenotypic DST in Ethiopia. Sanger sequencing directly from sputum may accelerate accurate clinical decision-making in the future.
China’s non-ferrous metal recycling technology convergence and driving factors: A quadratic assignment procedure analysis based on patent collaboration-based network structural hole
Authors: Luo Kai , Zor Shutter
Published: August 2022

Technological convergence is an important organizational innovation capability, essential for improving the core competitiveness of green and sustainable industries. However, studies have mainly focused on measuring technological convergence and have ignored the factors that affect the capabilities of such convergence capabilities. Thus, this study attempts to bridge this gap by providing an in-depth analysis of the impact of structural holes in inter-organizational technical cooperation networks. This technological convergence is studied from the perspective of a patent. It also considers the moderating effects of the degree of patent cooperation and the cooperation distance. It employs the social network theory to construct inter-organizational patent cooperation, and technological convergence networks, to facilitate the analysis of the effect of structural holes on such a convergence. It empirically examines 52 non-ferrous metal recycling organizations, with close patent cooperation. Accordingly, the structural hole constraint index by the inter-organizational patent cooperation network, shows a positive U-shaped curve relationship with technology convergence. Moreover, the degree of inter-organizational patent cooperation strengthens the positive U-shaped relationship, and the distance of cooperation weakens the influence of the structural hole constraint index on technology convergence. Therefore, managers and policymakers should encourage more industry-academia-research or patent alliances and designate policies to promote such cooperation.
The relationship between physical activity and prosocial behavior of college students: A mediating role of self-perception
Authors: Lu Tian Ci , Wang Cai Xia , Tao Bao Le , Sui Hao Ran , Yan Jun
Published: August 2022

Objective

To explore the relationship between physical activity and prosocial behavior in college students, and to examine whether self-perception and gender may play mediating and moderating roles, respectively, in that relationship.

Methods

The International Physical Activity Questionnaire-long form, Prosocial Tendencies Measure, and Self-perception Scale were used to survey 647 college students in Yangzhou, China. Internal consistency testing, one-way analyses of variance (ANOVAs) across physical activity levels, exploratory factor analysis, correlation testing, mediation effect testing (independent variable, physical activity; mediating variable, self-perception; dependent variable, prosocial behavior), bootstrap testing and moderated mediation testing were conducted.

Results

Physical activity level was not found to be a direct predictor prosocial behavior in college students. Self-perception was found to play a mediating role between physical activity and prosocial behavior.

Conclusion

Physical activity is not directly predictive college students’ prosocial behavior tendencies, but it is indirectly predictive through self-perception. This study explores the relationship between the three variables and the path of the relationship, deepening the research related to the relationship between physical activity and prosocial behavior, providing ideas for fostering prosocial behavior in Chinese universities, as well as providing a theoretical basis for possible future empirical research.
Incidence and risk factors of COVID-19 associated pneumothorax
Authors: Taha Muhanad , Elahi Morvarid , Wahby Krista , Samavati Lobelia
Published: August 2022

Background

Pneumothorax has been increasingly observed among patients with coronavirus disease-2019 (COVID-19) pneumonia, specifically in those patients who develop acute respiratory distress syndrome (ARDS). In this study, we sought to determine the incidence and potential risk factors of pneumothorax in critically ill adults with COVID-19.

Method

This retrospective cohort study included adult patients with laboratory-confirmed SARS-CoV-2 infection admitted to one of the adult intensive care units of a tertiary, academic teaching hospital from May 2020 through May 2021.

Results

Among 334 COVID-19 cases requiring ICU admission, the incidence of pneumothorax was 10% (33 patients). Patients who experienced pneumothorax more frequently required vasopressor support (28/33 [84%] vs. 191/301 [63%] P = 0.04), were more likely to be proned (25/33 [75%] vs. 111/301 [36%], P<0.001), and the presence of pneumothorax was associated with prolonged duration of mechanical ventilation; 21 (1–97) versus 7 (1–79) days, p<0.001 as well as prolonged hospital length of stay (29 [9–133] vs. 15 [1–90] days, P<0.001), but mortality was not significantly different between groups. Importantly, when we performed a Cox proportional hazard ratio (HR) model of multivariate parameters, we found that administration of tocilizumab significantly increased the risk of developing pneumothorax (HR = 10.7; CI [3.6–32], P<0.001).

Conclusion

Among 334 critically ill patients with COVID-19, the incidence of pneumothorax was 10%. Presence of pneumothorax was associated with prolonged duration of mechanical ventilation and length of hospital stay. Strikingly, receipt of tocilizumab was associated with an increased risk of developing pneumothorax.
Diagnostic accuracy of S-Detect in distinguishing benign and malignant thyroid nodules: A meta-analysis
Authors: Zhong Lin , Wang Cong
Published: August 2022

Objectives

In this meta-analysis study, the main objective was to determine the accuracy of S-detect in effectively distinguishing malignant thyroid nodules from benign thyroid nodules.

Methods

We searched the PubMed, Cochrane Library, and CBM databases from inception to August 1, 2021. Meta-analysis was conducted using STATA version 14.0 and Meta-Disc version 1.4 softwares. We calculated summary statistics for sensitivity (Sen), specificity (Spe), positive and negative likelihood ratio (LR+/LR−), diagnostic odds ratio(DOR), and receiver operating characteristic (SROC) curves. Cochran’s Q-statistic and I2 test were used to evaluate potential heterogeneity between studies. A sensitivity analysis was performed to evaluate the influence of single studies on the overall estimate. We also performed meta-regression analyses to investigate the potential sources of heterogeneity.

Results

In this study, a total of 17 studies meeting the requirements of the standard were used. The number of benign and malignant nodules analyzed and evaluated in this paper was 1595 and 1118 respectively. This paper mainly completes the required histological confirmation through s-detect. The pooled Sen and pooled Spe were 0.87 and 0.74, respectively, (95%CI = 0.84–0.89) and (95%CI = 0.66–0.81). Furthermore, the pooled LR+ and negative LR− were determined to be 3.37 (95%CI = 2.53–4.50) and 0.18 (95%CI = 0.15–0.21), respectively. The experimental results showed that the pooled DOR of thyroid nodules was 18.83 (95% CI = 13.21–26.84). In addition, area under SROC curve was determined to be 0.89 (SE = 0.0124). It should be pointed out that there is no evidence of bias (i.e. t = 0.25, P = 0.80).

Conclusions

Through this meta-analysis, it can be seen that the accuracy of s-detect is relatively high for the effective distinction between malignant thyroid nodules and benign thyroid nodules.
Elevational biodiversity gradients in the Neotropics: Perspectives from freshwater caddisflies (Insecta: Trichoptera)
Authors: Ríos-Touma Blanca , Cuesta Francisco , Rázuri-Gonzales Ernesto , Holzenthal Ralph , Tapia Andrea , Calderón-Loor Marco
Published: August 2022

Aquatic insects in the order Trichoptera are extremely diverse in number of species and their trophic roles. However, their distribution and diversity patterns are poorly known in the Neotropics, including the species restricted to tropical mountain ecosystems. Recent studies in tropical mountains have shown high levels of endemism of aquatic insects and changes in the composition of communities over short distances. Still, the incidence of environmental filters that explain such patterns has not been addressed quantitatively. Given the relevance of understanding Trichoptera spatial diversity patterns to prioritize conservation areas for freshwaters, as well as to obtain baseline information to predict changes in aquatic communities facing global environmental changes, we assessed the species distribution and assemblages of caddisflies along an elevational gradient from 600 to 3,600 m a.s.l. on the equatorial Andes. In this area, we had long-term continuous climate data with hourly resolution. We collected adult caddisflies in seven localities along this gradient using light traps. We sampled each locality for two hours after sunset for three consecutive days. All specimens collected were identified to species or morphospecies. Our results showed an increase in species and genera numbers with decreasing altitude, albeit no significant. Minimum air temperature is the main environmental variable explaining Trichoptera community assemblages. β‐diversity (taxon turnover among sites), as opposed to species richness, increased with altitude and showed a bimodal distribution along the elevation gradient for both genera and species assemblages, which resulted in a significant shift in community composition of species and genera at 2,000 m a.s.l. Our null-models confirm the observed patterns of B-diversity are non-random and suggest a strong environmental filtering of tropical caddisflies community assemblies and turnover. Geographic distance coupled with changes in environmental conditions along the elevation gradient explained a high percentage of community variance, as documented for other taxa (e.g., vascular plants), suggesting the importance of securing habitat connectivity along the altitudinal gradient to protect aquatic insect diversity effectively.
Seasonality and geography of diabetes mellitus in United States of America dogs
Authors: Qiu Liang N. Y. , Cai Stephen V. , Chan Dennis , Hess Rebecka S.
Published: August 2022

The diagnosis of type 1 diabetes mellitus (DM) in humans is associated with high altitude, few sunshine hours, cold climate, and winter. The goals of this study were to investigate seasonal and geographic patterns of DM diagnosis in United States of America (USA) dogs with juvenile and mature onset DM. Data were collected by means of an online survey widely distributed in the USA through breed clubs, academic veterinary institutions, private veterinary referral practices, social media outlets, and the American Kennel Club. Juvenile DM (JDM) and mature onset DM were defined as DM with an age of onset <365 days and DM with an age of onset ≥365 days, respectively. Meteorological seasons were defined as: winter from December through February, spring from March through May, summer from June through August, and fall from September through November. Four geographic regions were also defined as the West, North, South, and Central regions of the USA. Nonoverlapping 95% confidence intervals (CI) for season, geographic region, and breed specific proportions of dogs with JDM were considered statistically significantly different. The study included 933 dogs with mature onset DM and 27 dogs with JDM. Dogs were diagnosed with DM significantly more in the winter and northern USA compared to all other seasons and all other geographic regions, respectively. The prevalence of JDM among dogs with DM was 2.8%. The proportion of dogs with JDM among pure breeds was not significantly different than the proportion of JDM in mixed breed dogs. It is concluded that winter and cold climate could be shared environmental factors influencing DM expression in dogs and humans. Additionally, pure breed dogs do not appear to be at increased risk for JDM compared to mixed breed dogs, indicating that factors other than genetics could influence spontaneous JDM development in dogs.
Effect of Zanthoxylum bungeanum essential oil on rumen enzyme activity, microbiome, and metabolites in lambs
Authors: Zhang Hailong , Lang Xia , Li Xiao , Chen Guoshun , Wang Cailian
Published: August 2022

Antibiotics were once used in animal production to improve productivity and resistance to pathogenic microbiota. However, due to its negative effects, the search for a new class of substances that can replace its efficacy has become one of the urgent problems to be solved. Plant essential oils (EOs) as a natural feed additive can maintain microbiota homeostasis and improve animal performance. However, its specific mechanism of action needs to be further investigated. Therefore, we added different doses of essential oil of Zanthoxylum bungeanum (EOZB) to the diets of Small Tail Han Sheep hybrid male lambs (STH lambs) to evaluate the effect of EOZB on rumen enzyme activity, rumen microbiology, and its metabolites in STH lambs. Twenty STH lambs were randomly divided into four groups (n = 5/group) and provided with the same diet. The dietary treatments were as follows: basal diet (BD) group; BD+EOZB 5 ml/kg group; BD+EOZB 10 ml/kg group; BD+EOZB 15 ml/kg group. We found that EOZB 10 ml/kg helped to increase rumen pectinase (P<0.05) and lipase (P<0.05) activities. Microbial 16S rRNA gene analysis showed that EOZB significantly altered the abundance of rumen microbiota (P<0.05). LC/GC-MS metabolomic analysis showed that the addition of EOZB produced a total of 1073 differential metabolites, with 58 differential metabolites remaining after raising the screening criteria. These differential metabolites were mainly enriched in glycerophospholipid metabolism, choline metabolism in cancer, retrograde endocannabinoid signaling, benzoxazinoid biosynthesis, and protein digestion and absorption. Correlation analysis showed that some rumen microbiota were significantly correlated with differential metabolite and enzyme activities.
Ocular biometric changes following unilateral cataract surgery in children
Authors: Park Yooyeon , Yum Hae Ri , Shin Sun Young , Park Shin Hae
Published: August 2022

Purpose

To analyze ocular biometric changes following unilateral cataract surgery in children.

Methods

A total of 57 children aged under 13 years who underwent unilateral cataract surgery were analyzed. Groups were classified according to their age at surgery: group I (age <3), II (3≤ age <6), III (6≤ age <9), and IV (age ≥9). The myopic shift, axial growth, and corneal curvature changes were compared between the pseudophakic eyes and the fellow phakic eyes.

Results

During 7.81 ± 4.39 years, the overall myopic shift (D) and the rate of myopic shift (D/year) were significantly higher at -3.25 ± 3.21 D and -0.45 ± 0.44 D/year in the pseudophakic eyes than -1.78 ± 2.10 D and -0.22 ± 0.29 D/year in the fellow phakic eyes (P = 0.01, 0.004). Group I (-1.14 ± 0.66 vs -0.02 ± 0.45 D/year) and group II (-0.63 ± 0.37 vs -0.31 ± 0.29 D/year) showed significantly higher rate of myopic shift in the pseudophakic eyes than in the phakic eyes. The rate of myopic shift in the pseudophakic eyes decreased in the older age groups (P = 0.001). There was no significant between-eye difference in the changes in axial length and keratometric values postoperatively.

Conclusion

Following unilateral cataract surgery, a significant postoperative myopic shift was noticed in the pseudophakic eyes compared to the fellow phakic eyes in groups under 6 years old. Postoperative myopic shift and the resultant anisometropia should be considered when selecting the optimal power of IOL in young children requiring unilateral cataract surgery.
Autistic adults’ views and experiences of requesting and receiving workplace adjustments in the UK
Authors: Davies Jade , Heasman Brett , Livesey Adam , Walker Amy , Pellicano Elizabeth , Remington Anna
Published: August 2022

This article examines 181 autistic adults’ views toward, and experiences of, requesting and receiving workplace adjustments in the UK. Using an online survey, we collected both qualitative and quantitative data relating to individuals’ experiences. While the majority of participants perceived workplace adjustments to be important, many were not receiving them. Analysis of open-ended text responses highlighted specific challenges that autistic people face in requesting and receiving adjustments. Specifically, participants felt the onus fell on them to (1) identify their need for adjustments; (2) establish the specific adjustments that would be beneficial and (3) request adjustments from their employer. Yet, they reported struggling with this process. Participants also highlighted a range of social and organisational barriers to the successful implementation of workplace adjustments. Unsurprisingly, the lack of successfully implemented adjustments had far-reaching impacts on participants’ wellbeing as well as the choices they made about their future employment. These findings highlight the need for employers to take a more active role in the identification and implementation of workplace adjustments, as well as a need for more understanding and inclusive working environments that truly allow autistic employees to thrive in the workplace.