bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of denoising tools for the reconstruction of nonlinear multimodal images
Authors: Houhou Rola , Quansah Elsie , Meyer-Zedler Tobias , Schmitt Michael , Hoffmann Franziska , Guntinas-Lichius Orlando , Popp Jürgen , Bocklitz Thomas
Published: April 2023

Biophotonic multimodal imaging techniques provide deep insights into biological samples such as cells or tissues. However, the measurement time increases dramatically when high-resolution multimodal images (MM) are required. To address this challenge, mathematical methods can be used to shorten the acquisition time for such high-quality images. In this research, we compared standard methods, e.g., the median filter method and the phase retrieval method via the Gerchberg-Saxton algorithm with artificial intelligence (AI) based methods using MM images of head and neck tissues. The AI methods include two approaches: the first one is a transfer learning-based technique that uses the pre-trained network DnCNN. The second approach is the training of networks using augmented head and neck MM images. In this manner, we compared the Noise2Noise network, the MIRNet network, and our deep learning network namely incSRCNN, which is derived from the super-resolution convolutional neural network and inspired by the inception network. These methods reconstruct improved images using measured low-quality (LQ) images, which were measured in approximately 2 seconds. The evaluation was performed on artificial LQ images generated by degrading high-quality (HQ) images measured in 8 seconds using Poisson noise. The results showed the potential of using deep learning on these multimodal images to improve the data quality and reduce the acquisition time. Our proposed network has the advantage of having a simple architecture compared with similar-performing but highly parametrized networks DnCNN, MIRNet, and Noise2Noise.
Machine learning enhancement of a digital twin for wavelength division multiplexing network performance prediction leveraging quality of transmission parameter refinement
Authors: Morette Nathalie , Hafermann Hartmut , Frignac Yann , Pointurier Yvan
Published: April 2023

Digital twins capable of quality of transmission (QoT) estimation and prediction are powerful tools for efficient design and operation of optical networks. In this paper, we employ machine learning techniques to enhance both the QoT estimation and prediction capabilities of an optical network digital twin. By leveraging a method to infer or refine the unknown lumped loss distributions and amplifier gain spectra for accurate characterization of the current optical network state, the accuracy of estimation and prediction is substantially improved. For QoT prediction, we further develop a novel neural-network architecture for erbium-doped fiber amplifiers that, after factory training on a single device and with fully loaded configurations only, generalizes to partially loaded configurations seen after deployment and to different gain and tilt settings and other physical devices of the same type. We combine refined parameters and a novel method that predicts the difference in per-channel power when individual services are added or removed or multiple services are lost due to a fiber cut. The impact of error amplification due to cascading of individual components’ models is shown to be reduced, yielding predictions that are substantially more accurate than simply cascaded predictions. As the network ages, the digital twin can be updated by retraining while using only information available in the current network state.
Integrated SOAs enable energy-efficient intra-data center coherent links
Authors: Maharry Aaron , Andrade Hector , Misak Stephen , Liu Junqian , Xia Yujie , Wissing Aaron , Movaghar Ghazal , Arrunategui-Norvick Viviana , Chansky Evan D. , Du Xinhong , Saleh Adel A. M. , Buckwalter James F. , Coldren Larry , Schow Clint L.
Published: April 2023

Coherent optical links are becoming increasingly attractive for intra-data center applications as data rates scale. Realizing the era of high-volume short-reach coherent links will require substantial improvements in transceiver cost and power efficiency, necessitating a reassessment of conventional architectures best-suited for longer-reach links and a review of assumptions for shorter-reach implementations. In this work, we analyze the impact of integrated semiconductor optical amplifiers (SOAs) on link performance and power consumption, and describe the optimal design spaces for low-cost and energy-efficient coherent links. Placing SOAs after the modulator provide the most energy-efficient link budget improvement, up to 6 pJ/bit for large link budgets, despite any penalties from nonlinear impairments. Increased robustness to SOA nonlinearities makes QPSK-based coherent links especially attractive, and larger supported link budgets enable the inclusion of optical switches, which could revolutionize data center networks and improve overall energy efficiency.
Nanoscale phase separation on an AlGaN surface characterized by scanning diffusion microscopy
Authors: Liu Boyang , Liu Zhenghui , Xu Gengzhao , Song Wentao , Zhang Chunyu , Chen Kebei , Han Sha , Sun Xiaojuan , Li Dabing , Xu Ke
Published: April 2023

AlGaN is an important material for deep ultraviolet optoelectronic devices and electronic devices. The phase separation on the AlGaN surface means small-scale compositional fluctuations of Al, which is prone to degrade the performance of devices. In order to study the mechanism of the surface phase separation, the Al0.3Ga0.7N wafer was investigated by the scanning diffusion microscopy method based on the photo-assisted Kelvin force probe microscope. The response of the surface photovoltage near the bandgap was quite different for the edge and the center of the island on the AlGaN surface. We utilize the theoretical model of scanning diffusion microscopy to fit the local absorption coefficients from the measured surface photovoltage spectrum. During the fitting process, we introduce as and ab parameters (bandgap shift and broadening) to describe the local variation of absorption coefficients α(as, ab, λ). The local bandgap and Al composition can be calculated quantitatively from the absorption coefficients. The results show that there is lower bandgap (about 305 nm) and lower Al composition (about 0.31) at the edge of the island, compared with those at the center of the island (about 300 nm for bandgap and 0.34 for Al composition). Similar to the edge of the island, there is a lower bandgap at the V-pit defect which is about 306 nm corresponding to the Al composition of about 0.30. These results mean Ga enrichment both at the edge of the island and the V-pit defect position. It proves that scanning diffusion microscopy is an effective method to review the micro-mechanism of AlGaN phase separation.
Mueller matrix imaging of pathological slides with plastic coverslips
Authors: Huang Tongyu , Yao Yue , Pei Haojie , Hu Zheng , Zhang Fengdi , Wang Jing , Yu Guangyin , Huang Chuqiang , Liu Huanyu , Tao Lili , Ma Hui
Published: April 2023

Mueller matrix microscopy is capable of polarization characterization of pathological samples and polarization imaging based digital pathology. In recent years, hospitals are replacing glass coverslips with plastic coverslips for automatic preparations of dry and clean pathological slides with less slide-sticking and air bubbles. However, plastic coverslips are usually birefringent and introduce polarization artifacts in Mueller matrix imaging. In this study, a spatial frequency based calibration method (SFCM) is used to remove such polarization artifacts. The polarization information of the plastic coverslips and the pathological tissues are separated by the spatial frequency analysis, then the Mueller matrix images of pathological tissues are restored by matrix inversions. By cutting two adjacent lung cancer tissue slides, we prepare paired samples of very similar pathological structures but one with a glass coverslip and the other with a plastic coverslip. Comparisons between Mueller matrix images of the paired samples show that SFCM can effectively remove the artifacts due to plastic coverslip.
Parity-time symmetry breaking optical nanocircuit
Authors: Li Haojie , Jia Qianwen , Lyu Bokun , Cao Fengzhao , Yang Guoxia , Liu Dahe , Shi Jinwei
Published: April 2023

Gain and loss balanced parity-time (PT) inversion symmetry has been achieved across multiple platforms including acoustics, electronics, and photonics. Tunable subwavelength asymmetric transmission based on PT symmetry breaking has attracted great interest. However, due to the diffraction limit, the geometric size of an optical PT symmetric system is much larger than the resonant wavelength, which limits the device miniaturization. Here, we theoretically studied a subwavelength optical PT symmetry breaking nanocircuit based on the similarity between a plasmonic system and an RLC circuit. Firstly, the asymmetric coupling of an input signal is observed by varying the coupling strength and gain-loss ratio between the nanocircuits. Furthermore, a subwavelength modulator is proposed by modulating the gain of the amplified nanocircuit. Notably, the modulation effect near the exceptional point is remarkable. Finally, we introduce a four-level atomic model modified by the Pauli exclusion principle to simulate the nonlinear dynamics of a PT symmetry broken laser. The asymmetric emission of a coherent laser is realized by full-wave simulation with a contrast of about 50. This subwavelength optical nanocircuit with broken PT symmetry is of great significance for realizing directional guided light, modulator and asymmetric-emission laser at subwavelength scales.
Feature ghost imaging for color identification
Authors: Gao Zihan , Li Minghui , Zheng Peixia , Xiong Jiahao , Zhang Xuan , Tang Zikang , Liu Hong-Chao
Published: April 2023

On the basis of computational ghost imaging (CGI), we present a new imaging technique, feature ghost imaging (FGI), which can convert the color information into distinguishable edge features in retrieved grayscale images. With the edge features extracted by different order operators, FGI can obtain the shape and the color information of objects simultaneously in a single-round detection using one single-pixel detector. The feature distinction of rainbow colors is presented in numerical simulations and the verification of FGI’s practical performance is conducted in experiments. Furnishing a new perspective to the imaging of colored objects, our FGI extends the function and the application fields of traditional CGI while sustaining the simplicity of the experimental setup.
High-efficiency fluoroindate glass fiber laser
Authors: Ososkov Yan , Lee Jinho , Fernandez Toney T. , Fuerbach Alex , Jackson Stuart D.
Published: April 2023

We report the high-efficiency operation of a 3.05 µm dysprosium-doped fluoroindate glass fiber laser that is in-band pumped at 2.83 µm using an erbium-doped fluorozirconate glass fiber laser. The demonstrated slope efficiency of the free-running laser of 82% represents approximately 90% of the Stokes efficiency limit; a maximum output power of 0.36 W, the highest for a fluoroindate glass fiber laser, was recorded. Narrow-linewidth wavelength stabilization at 3.2 µm was achieved by utilizing a first-reported, to the best of our knowledge, high-reflectivity fiber Bragg grating inscribed in the Dy3+-doped fluoroindate glass. These results lay the foundation for future power-scaling of mid-infrared fiber lasers using fluoroindate glass.
Nonlinear pulse compression to sub-two-cycle, 1.3 mJ pulses at 1.9 μm wavelength with 132 W average power
Authors: Wang Ziyao , Heuermann Tobias , Gebhardt Martin , Lenski Mathias , Gierschke Philipp , Klas Robert , Rothhardt Jan , Jauregui Cesar , Limpert Jens
Published: April 2023

We report the nonlinear pulse compression of a high-power, thulium-doped fiber laser system using a gas-filled hollow-core fiber. The sub-two cycle source delivers 1.3 mJ pulse energy with 80 GW peak power at a central wavelength of 1.87 μm and an average power of 132 W. This is, so far, to the best of our knowledge, the highest average power of a few-cycle laser source reported in the short-wave infrared region. Given its unique combination of high pulse energy and high average power, this laser source is an excellent driver for nonlinear frequency conversion, toward terahertz, mid-infrared, and soft X-ray spectral regions.
Fiber-optic hydrophone for detection of high-intensity ultrasound waves
Authors: Aytac Kipergil Esra , Martin Eleanor , Mathews Sunish J. , Papakonstantinou Ioannis , Alles Erwin J. , Desjardins Adrien E.
Published: April 2023

Fiber-optic hydrophones (FOHs) are widely used to detect high-intensity focused ultrasound (HIFU) fields. The most common type consists of an uncoated single-mode fiber with a perpendicularly cleaved end face. The main disadvantage of these hydrophones is their low signal-to-noise ratio (SNR). To increase the SNR, signal averaging is performed, but the associated increased acquisition times hinder ultrasound field scans. In this study, with a view to increasing SNR while withstanding HIFU pressures, the bare FOH paradigm is extended to include a partially reflective coating on the fiber end face. Here, a numerical model based on the general transfer-matrix method was implemented. Based on the simulation results, a single-layer, 172 nm TiO2-coated FOH was fabricated. The frequency range of the hydrophone was verified from 1 to 30 MHz. The SNR of the acoustic measurement with the coated sensor was 21 dB higher than that of the uncoated one. The coated sensor successfully withstood a peak positive pressure of 35 MPa for 6000 pulses.
The conserved AAA ATPase PCH-2 distributes its regulation of meiotic prophase events through multiple meiotic HORMADs in C. elegans
Authors: Russo Anna E. , Giacopazzi Stefani , Deshong Alison , Menon Malaika , Ortiz Valery , Ego Kaori M. , Corbett Kevin D. , Bhalla Needhi
Published: April 2023

During meiotic prophase, the essential events of homolog pairing, synapsis, and recombination are coordinated with meiotic progression to promote fidelity and prevent aneuploidy. The conserved AAA+ ATPase PCH-2 coordinates these events to guarantee crossover assurance and accurate chromosome segregation. How PCH-2 accomplishes this coordination is poorly understood. Here, we provide evidence that PCH-2 decelerates pairing, synapsis and recombination in C. elegans by remodeling meiotic HORMADs. We propose that PCH-2 converts the closed versions of these proteins, which drive these meiotic prophase events, to unbuckled conformations, destabilizing interhomolog interactions and delaying meiotic progression. Further, we find that PCH-2 distributes this regulation among three essential meiotic HORMADs in C. elegans: PCH-2 acts through HTP-3 to regulate pairing and synapsis, HIM-3 to promote crossover assurance, and HTP-1 to control meiotic progression. In addition to identifying a molecular mechanism for how PCH-2 regulates interhomolog interactions, our results provide a possible explanation for the expansion of the meiotic HORMAD family as a conserved evolutionary feature of meiosis. Taken together, our work demonstrates that PCH-2’s remodeling of meiotic HORMADs has functional consequences for the rate and fidelity of homolog pairing, synapsis, recombination and meiotic progression, ensuring accurate meiotic chromosome segregation.
Germline stem cell integrity and quiescence are controlled by an AMPK-dependent neuronal trafficking pathway
Authors: Wong Christopher , Kadekar Pratik , Jurczak Elena , Roy Richard
Published: April 2023

During periods of energetic stress, Caenorhabditis elegans can execute a developmentally quiescent stage called “dauer”, during which all germline stem cells undergo a G2 cell cycle arrest. In animals that lack AMP-activated protein kinase (AMPK) signalling, the germ cells fail to arrest, undergo uncontrolled proliferation, and lose their reproductive capacity upon recovery from this quiescent stage. These germline defects are accompanied by, and likely result from, an altered chromatin landscape and gene expression program. Through genetic analysis we identified an allele of tbc-7, a predicted RabGAP protein that functions in the neurons, which when compromised, suppresses the germline hyperplasia in the dauer larvae, as well as the post-dauer sterility and somatic defects characteristic of AMPK mutants. This mutation also corrects the abundance and aberrant distribution of transcriptionally activating and repressive chromatin marks in animals that otherwise lack all AMPK signalling. We identified RAB-7 as one of the potential RAB proteins that is modulated by tbc-7 and show that the activity of RAB-7 is critical for the maintenance of germ cell integrity during the dauer stage. We reveal that TBC-7 is regulated by AMPK through two mechanisms when the animals enter the dauer stage. Acutely, the AMPK-mediated phosphorylation of TBC-7 reduces its activity, potentially by autoinhibition, thereby preventing the inactivation of RAB-7. In the more long term, AMPK regulates the miRNAs mir-1 and mir-44 to attenuate tbc-7 expression. Consistent with this, animals lacking mir-1 and mir-44 are post-dauer sterile, phenocopying the germline defects of AMPK mutants. Altogether, we have uncovered an AMPK-dependent and microRNA-regulated cellular trafficking pathway that is initiated in the neurons, and is critical to control germline gene expression cell non-autonomously in response to adverse environmental conditions.
A community developed conceptual model for reducing long-term health problems in children with intellectual disability in India
Authors: Nair Manisha , Hazarika Mythili , Kishore M Thomas , Sengupta Nabarun , Sheregar Ganesh , MacGregor Hayley , Wickenden Mary , Kaushik Neel Harit , Saikia Prarthana , Kelley Maureen , Shepperd Sasha
Published: April 2023

Children with intellectual disability (ID) have a higher risk of long-term health problems in adulthood. India has the highest prevalence of ID of any country with 1.6 million under-five children living with the condition. Despite this, compared with other children, this neglected population is excluded from mainstream disease prevention and health promotion programmes. Our objective was to develop an evidence-based conceptual framework for a needs-based inclusive intervention to reduce the risk of communicable and non-communicable diseases among children with ID in India. From April through to July 2020 we undertook community engagement and involvement activities in ten States in India using a community-based participatory approach, guided by the bio-psycho-social model. We adapted the five steps recommended for the design and evaluation of a public participation process for the health sector. Seventy stakeholders from ten States contributed to the project: 44 parents and 26 professionals who work with people with ID. We mapped the outputs from two rounds of stakeholder consultations with evidence from systematic reviews to develop a conceptual framework that underpins an approach to develop a cross-sectoral family-centred needs-based inclusive intervention to improve health outcomes for children with ID. A working Theory of Change model delineates a pathway that reflected the priorities of the target population. We discussed the models during a third round of consultations to identify limitations, relevance of the concepts, structural and social barriers that could influence acceptability and adherence, success criteria, and integration with existing health system and service delivery. There are currently no health promotion programmes focusing on children with ID in India despite the population being at a higher risk of developing comorbid health problems. Therefore, an urgent next step is to test the conceptual model to determine acceptance and effectiveness within the context of socio-economic challenges faced by the children and their families in the country.
Barriers and facilitators for the provision of radiology services in Zimbabwe: A qualitative study based on staff experiences and observations
Authors: Hinrichs-Krapels Saba , Tombo Lazarus , Boulding Harriet , Majonga Edith D. , Cummins Carole , Manaseki-Holland Semira
Published: April 2023

Despite its fundamental role in diagnostic and curative care, radiology has been described as a neglected essential service in many low and middle-income countries (LMICs). Previous studies have demonstrated basic equipment and infrastructure shortages in LMIC settings, but no studies to date have gone further in understanding the perceptions and experiences of staff delivering radiology services, as a way of identifying their perspectives on barriers and facilitators for delivering services, and the potential for where improvements can be made. Our qualitative study aimed to: (a) identify barriers for delivering radiology services, and (b) suggest potential facilitators for improvement of radiology service delivery in the Zimbabwean context; from the perspective of radiology staff. We conducted semi-structured interviews (n = 13) and three focus groups (n = 24 radiographers), followed by four half- to full- days of field observations to validate insights from the interviews and focus groups in all three public hospitals and one private hospital in the Harare metropolitan area. Our study identified four main barriers for delivering radiology services: (i) poor basic infrastructure, equipment, and consumables; (ii) suboptimal equipment maintenance; (iii) shortage of radiology staff and skills development; and (iv) lack of wider integration and support for radiology services. We also identified a strong sense of motivation among staff to keep radiology services, pointing to what may be an enabler and facilitator for improving radiology services. These findings point to potential risks to patient safety and quality of delivering radiology services. More importantly, we found a strong sense of personal motivation displayed by the staff, suggesting there is the potential to maintain and improve existing practices, but this would require investments to train and remunerate more radiology staff, as well as investing in continuing professional development.
Allometric equation for Raphia laurentii De Wild, the commonest palm in the central Congo peatlands
Authors: Bocko Yannick Enock , Panzou Grace Jopaul Loubota , Dargie Greta Christina , Mampouya Yeto Emmanuel Wenina , Mbemba Mackline , Loumeto Jean Joël , Lewis Simon L.
Published: April 2023

The world’s largest tropical peatland lies in the central Congo Basin. Raphia laurentii De Wild, the most abundant palm in these peatlands, forms dominant to mono-dominant stands across approximately 45% of the peatland area. R. laurentii is a trunkless palm with fronds up to 20 m long. Owing to its morphology, there is currently no allometric equation which can be applied to R. laurentii. Therefore it is currently excluded from aboveground biomass (AGB) estimates for the Congo Basin peatlands. Here we develop allometric equations for R. laurentii, by destructively sampling 90 individuals in a peat swamp forest, in the Republic of the Congo. Prior to destructive sampling, stem base diameter, petiole mean diameter, the sum of petiole diameters, total palm height, and number of palm fronds were measured. After destructive sampling, each individual was separated into stem, sheath, petiole, rachis, and leaflet categories, then dried and weighed. We found that palm fronds represented at least 77% of the total AGB in R. laurentii and that the sum of petiole diameters was the best single predictor variable of AGB. The best overall allometric equation, however, combined the sum of petiole diameters (SDp), total palm height (H), and tissue density (TD): AGB = Exp(−2.691 + 1.425 × ln(SDp) + 0.695 × ln(H) + 0.395 × ln(TD)). We applied one of our allometric equations to data from two nearby 1-hectare forest plots, one dominated by R. laurentii, where R. laurentii accounted for 41% of the total forest AGB (with hardwood tree AGB estimated using the Chave et al. 2014 allometric equation), and one dominated by hardwood species, where R. laurentii accounted for 8% of total AGB. Across the entire region we estimate that R. laurentii stores around 2 million tonnes of carbon aboveground. The inclusion of R. laurentii in AGB estimates, will drastically improve overall AGB, and therefore carbon stock estimates for the Congo Basin peatlands.
Quantitative differentiation of minimal-fat angiomyolipomas from renal cell carcinomas using grating-based x-ray phase-contrast computed tomography: An ex vivo study
Authors: Birnbacher Lorenz , Braunagel Margarita , Willner Marian , Marschner Mathias , De Marco Fabio , Viermetz Manuel , Auweter Sigrid , Notohamiprodjo Susan , Hellbach Katharina , Notohamiprodjo Mike , Staehler Michael , Pfeiffer Daniela , Reiser Maximilian F. , Pfeiffer Franz , Herzen Julia
Published: April 2023

Background

The differentiation of minimal-fat—or low-fat—angiomyolipomas from other renal lesions is clinically challenging in conventional computed tomography. In this work, we have assessed the potential of grating-based x-ray phase-contrast computed tomography (GBPC-CT) for visualization and quantitative differentiation of minimal-fat angiomyolipomas (mfAMLs) and oncocytomas from renal cell carcinomas (RCCs) on ex vivo renal samples.

Materials and methods

Laboratory GBPC-CT was performed at 40 kVp on 28 ex vivo kidney specimens including five angiomyolipomas with three minimal-fat (mfAMLs) and two high-fat (hfAMLs) subtypes as well as three oncocytomas and 20 RCCs with eight clear cell (ccRCCs), seven papillary (pRCCs) and five chromophobe RCC (chrRCC) subtypes. Quantitative values of conventional Hounsfield units (HU) and phase-contrast Hounsfield units (HUp) were determined and histogram analysis was performed on GBPC-CT and grating-based attenuation-contrast computed tomography (GBAC-CT) slices for each specimen. For comparison, the same specimens were imaged at a 3T magnetic resonance imaging (MRI) scanner.

Results

We have successfully matched GBPC-CT images with clinical MRI and histology, as GBPC-CT presented with increased soft tissue contrast compared to absorption-based images. GBPC-CT images revealed a qualitative and quantitative difference between mfAML samples (58±4 HUp) and oncocytomas (44±10 HUp, p = 0.057) and RCCs (ccRCCs: 40±12 HUp, p = 0.012; pRCCs: 43±9 HUp, p = 0.017; chrRCCs: 40±7 HUp, p = 0.057) in contrast to corresponding laboratory attenuation-contrast CT and clinical MRI, although not all differences were statistically significant. Due to the heterogeneity and lower signal of oncocytomas, quantitative differentiation of the samples based on HUp or in combination with HUs was not possible.

Conclusions

GBPC-CT allows quantitative differentiation of minimal-fat angiomyolipomas from pRCCs and ccRCCs in contrast to absorption-based imaging and clinical MRI.
Community-based empowerment program to delay marriage: Results from the More Than Brides Alliance intervention in India, Malawi, Mali and Niger
Authors: Melnikas Andrea J. , Saul Grace , Chau Michelle , Pandey Neelanajana , Gueye Mouhamadou , Mkandawire James , Diarra Aissa , Amin Sajeda
Published: April 2023

The More Than Brides Alliance (MTBA) implemented an intervention in India, Malawi, Mali and Niger from 2017 to 2020. The holistic community-based program included girls’ clubs focused on empowerment and sexual and reproductive health knowledge; work with parents and educators; community edutainment events; and local-, regional-, and national-level advocacy efforts related to child marriage. Using a cluster randomized trial design (India and Malawi), and a matched comparison design (Niger and Mali), we evaluated the effectiveness of the program on age at marriage among girls ages 12–19 in intervention communities. Repeat cross sectional surveys were collected at baseline (2016/7), midline after approximately 18 months of intervention (2018), and endline (2020). Impact was assessed using difference-in-difference (DID) analysis, adjusted for the cluster design. We find that the intervention was successful at reducing the proportion of girls ages 12–19 married in India (-0.126, p < .001). Findings in the other countries did not show impact of the intervention on delaying marriage. Our findings suggest that the MTBA program was optimized to succeed in India, in part because it was built on an evidence base that relies heavily on data from South Asia. The drivers of child marriage in India may be substantially different from those in Malawi, Mali, and Niger and require alternate intervention approaches. These findings have implications for those designing programs outside of South Asia and suggest that programs need to consider context-specific drivers and whether and how evidence-based programs operate in relation to those drivers.

Trial registration:This work is part of an RCT registered August 4, 2016 in the AEA RCT registry identified as:AEAR CTR-0001463. See:https://www.socialscienceregistry.org/trials/1463.
Access to HIV prevention, treatment, and care services during COVID-19 by men who have sex with men in Zimbabwe, An interpretive phenomenological analysis study
Authors: Moyo Idah , Mavhandu-Mudzusi Azwihangwisi Hellen , Lipeleke Freddy , Sibindi Musa
Published: April 2023

Background

Key populations are disproportionately affected by the human immunodeficiency virus (HIV) but have less access to HIV prevention and treatment services. The Coronavirus disease-2019 (COVID-19) pandemic is reinforcing health inequities among vulnerable populations, including men who have sex with men (MSM). Therefore, this article presents the findings describing the experiences of MSM in accessing HIV services during COVID-19 in the second largest city of Zimbabwe.

Methods

An interpretative phenomenological analysis design was applied to gain some insights regarding the lived experiences of MSM in accessing HIV prevention, treatment, and care services during COVID-19 lockdowns era in Zimbabwe. Data were collected from 14 criterion purposively selected MSM using in-depth, one-on-one interviews. Data were analysed thematically guided by the interpretative phenomenological analysis framework for data analysis.

Results

The findings demonstrated that during the COVID -19 lockdowns in Zimbabwe, MSM faced several barriers as they tried to access HIV services. Some of the barriers included the need for travel authorisation letters and treatment interruption. The study also found that COVID-19 and related restrictive measures had psychosocial and economic effects that encompassed loss of income, intimate partner violence and psychological effects.

Conclusions

Limited access to healthcare services by MSM due to COVID-19 lockdown may negatively affect the viral suppression and fuel the spread of HIV, which may reverse the gains toward the control of HIV epidemic. To sustain the gains toward HIV epidemic control and to ensure continuity of treatment, particularly for members of key populations, it is critical that the health-care delivery system adjusts by taking service to the community through adopting a differentiated service delivery approach.
First report of Planomicrobium okeanokoites associated with Himantothallus grandifolius (Desmarestiales, Phaeophyta) from Southern Hemisphere
Authors: Saini Khem Chand , Gupta Kriti , Sharma Sheetal , Gautam Ajay K. , Shamim Samrin , Mittal Divya , Kundu Pushpendu , Bast Felix
Published: April 2023

Gram-positive, aerobic, motile, rod-shaped, mesophilic epiphytic bacterium Planomicrobium okeanokoites was isolated from the surface of endemic species Himantothallus grandifolius in Larsemann Hills, Eastern Antarctica. The diversity of epiphytic bacterial communities living on marine algae remains primarily unexplored; virtually no reports from Antarctic seaweeds. The present study used morpho-molecular approaches for the macroalgae and epiphytic bacterium characterization. Phylogenetic analysis was performed using mitochondrial genome encoded COX1 gene; chloroplast genome encodes rbcL; nuclear genome encoded large subunit ribosomal RNA gene (LSU rRNA) for Himantothallus grandifolius and ribosomal encoded 16S rRNA for Planomicrobium okeanokoites. Morphological and molecular data revealed that the isolate is identified as Himantothallus grandifolius, which belongs to Family Desmarestiaceae of Order Desmarestiales in Class Phaeophyceae showing 99.8% similarity to the sequences of Himantothallus grandifolius, from King George Island, Antarctica (HE866853). The isolated bacterial strain was identified on the basis of chemotaxonomic, morpho-phylogenetic, and biochemical assays. A phylogenetic study based on 16S rRNA gene sequences revealed that the epiphytic bacterial strain SLA-357 was closest related to the Planomicrobium okeanokoites showing 98.7% sequence similarity. The study revealed the first report of this species from the Southern Hemisphere to date. Also, there has been no report regarding the association between the Planomicrobium okeanokoites and Himantothallus grandifolius; however, there are some reports on this bacterium isolated from sediments, soils, and lakes from Northern Hemisphere. This study may open a gateway for further research to know about the mode of interactions and how they affect the physiology and metabolism of each other.
Case management interventions in chronic disease reduce anxiety and depressive symptoms: A systematic review and meta-analysis
Authors: Geerlings Angelika D. , Janssen Daalen Jules M. , Ypinga Jan H. L. , Bloem Bastiaan R. , Meinders Marjan J. , Munneke Marten , Darweesh Sirwan K. L.
Published: April 2023

Background

There is no systematic insight into the effect of case management on common complications of chronic diseases, including depressive symptoms and symptoms of anxiety. This is a significant knowledge gap, given that people with a chronic disease such as Parkinson Disease or Alzheimer’s Disease have identified care coordination as one of their highest priorities. Furthermore, it remains unclear whether the putative beneficial effects of case management would vary by crucial patient characteristics, such as their age, gender, or disease characteristics. Such insights would shift from “one size fits all” healthcare resource allocation to personalized medicine.

Objective

We systematically examined the effectiveness of case management interventions on two common complications associated PD and other chronic health conditions: Depressive symptoms and symptoms of anxiety.

Methods

We identified studies published until November 2022 from PubMed and Embase databases using predefined inclusion criteria. For each study, data were extracted independently by two researchers. First, descriptive and qualitative analyses of all included studies were performed, followed by random-effects meta-analyses to assess the impact of case management interventions on anxiety and depressive symptoms. Second, meta-regression was performed to analyze potential modifying effects of demographic characteristics, disease characteristics and case management components.

Results

23 randomized controlled trials and four non-randomized studies reported data on the effect of case management on symptoms of anxiety (8 studies) or depressive symptoms (26 studies). Across meta-analyses, we observed a statistically significant effect of case management on reducing symptoms of anxiety (Standardized Mean Difference [SMD] = - 0.47; 95% confidence interval [CI]: -0.69, -0.32) and depressive symptoms (SMD = - 0.48; CI: -0.71, -0.25). We found large heterogeneity in effect estimates across studies, but this was not explained by patient population or intervention characteristics.

Conclusions

Among people with chronic health conditions, case management has beneficial effects on symptoms of depressive symptoms and symptoms of anxiety. Currently, research on case management interventions are rare. Future studies should assess the utility of case management for potentially preventative and common complications, focusing on the optimal content, frequency, and intensity of case management.
Nonalcoholic fatty liver disease and cognitive impairment: A prospective cohort study
Authors: Cushman Mary , Callas Peter W. , Alexander Kristine S. , Wadley Virginia , Zakai Neil A. , Lidofsky Steven D. , Unverzagt Frederick W. , Judd Suzanne E.
Published: April 2023

Background & aims

Nonalcoholic fatty liver disease (NAFLD) is prevalent and may affect cognitive function. We studied associations of NAFLD with risk of cognitive impairment. Secondarily we evaluated liver biomarkers (alanine aminotransferase (ALT), aspartate aminotransferase (AST), their ratio, and gamma-glutamyl transpeptidase).

Methods

In a prospective cohort study, the REasons for Geographic and Racial Differences in Stroke, among 30,239 black and white adults aged ≥45,495 cases of incident cognitive impairment were identified over 3.4 years follow up. Cognitive impairment was identified as new impairment in two of three cognitive tests administered every two years during follow up; word list learning and recall, and verbal fluency. 587 controls were selected from an age, race, sex-stratified sample of the cohort. The fatty liver index was used to define baseline NAFLD. Liver biomarkers were measured using baseline blood samples.

Results

NAFLD at baseline was associated with a 2.01-fold increased risk of incident cognitive impairment in a minimally adjusted model (95% CI 1.42, 2.85). The association was largest in those aged 45–65 (p interaction by age = 0.03), with the risk 2.95-fold increased (95% CI 1.05, 8.34) adjusting for cardiovascular, stroke and metabolic risk factors. Liver biomarkers were not associated with cognitive impairment, except AST/ALT >2, with an adjusted OR 1.86 (95% CI 0.81, 4.25) that did not differ by age.

Conclusions

A laboratory-based estimate of NAFLD was associated with development of cognitive impairment, particularly in mid-life, with a tripling in risk. Given its high prevalence, NAFLD may be a major reversible determinant of cognitive health.
Incentive effect of tax preferences towards the technological innovation of enterprises——Based on China’s GEM listed companies
Authors: Ding Liang , Wu Yunfeng , Long Junxia
Published: April 2023

The long R&D process, the high risk, and the externalities of technological innovation are challenges that enterprises have to meet when making decisions on R&D investment. Governments share this risk with enterprises through preferential tax policies. We summarized China’s preferential tax policies related to enterprises and R&D innovation, and used panel data of listed enterprises from 2013 to 2018 in the Growth Enterprises Market (GEM) of the Shenzhen Stock Exchange to explore the incentive effects of current tax policies on the R&D innovation of enterprises. Through empirical analysis, we found that tax incentives significantly motivate R&D innovation input and promote output. In addition, we found that the income tax incentives are greater than that of the circulation tax, since the profitability of enterprise has a positive correlation with R&D investment. Meanwhile, the size of the enterprise is negatively correlated with the intensity of R&D investment.
Analytical validation of a multi-cancer early detection test with cancer signal origin using a cell-free DNA–based targeted methylation assay
Authors: Alexander Gregory E. , Lin Wendy , Ortega Fabian E. , Ramaiah Madhuvanthi , Jung Byoungsok , Ji Lijuan , Revenkova Ekaterina , Shah Payal , Croisetiere Christian , Berman Jennifer R. , Eubank Lane , Naik Gunjan , Brooks Jacqueline , Mich Andrea , Shojaee Seyedmehdi , Ronaghi Neda , Chawla Hemanshi , Hou Xinyi , Liu Qinwen , Yakym Christopher-James A. V. , Moradi Patriss Wais , Halks-Miller Meredith , Aravanis Alexander M. , Parpart-Li Sonya , Hunkapiller Nathan
Published: April 2023

The analytical validation is reported for a targeted methylation-based cell-free DNA multi-cancer early detection test designed to detect cancer and predict the cancer signal origin (tissue of origin). A machine-learning classifier was used to analyze the methylation patterns of >105 genomic targets covering >1 million methylation sites. Analytical sensitivity (limit of detection [95% probability]) was characterized with respect to tumor content by expected variant allele frequency and was determined to be 0.07%-0.17% across five tumor cases and 0.51% for the lymphoid neoplasm case. Test specificity was 99.3% (95% confidence interval, 98.6–99.7%). In the reproducibility and repeatability study, results were consistent in 31/34 (91.2%) pairs with cancer and 17/17 (100%) pairs without cancer; between runs, results were concordant for 129/133 (97.0%) cancer and 37/37 (100%) non-cancer sample pairs. Across 3- to 100-ng input levels of cell-free DNA, cancer was detected in 157/182 (86.3%) cancer samples but not in any of the 62 non-cancer samples. In input titration tests, cancer signal origin was correctly predicted in all tumor samples detected as cancer. No cross-contamination events were observed. No potential interferent (hemoglobin, bilirubin, triglycerides, genomic DNA) affected performance. The results of this analytical validation study support continued clinical development of a targeted methylation cell-free DNA multi-cancer early detection test.
Frequency of unnecessary prenatal diagnosis of hemoglobinopathies: A large retrospective analysis and implication to improvement of the control program
Authors: Singha Kritsada , Yamsri Supawadee , Chaibunruang Attawut , Srivorakun Hataichanok , Sanchaisuriya Kanokwan , Fucharoen Goonnapa , Fucharoen Supan
Published: April 2023

Objective

To determine the frequency and etiology of unnecessary prenatal diagnosis for hemoglobinopathies during 12 years of services at a single university center in Thailand.

Methods

We conducted a retrospective cohort analysis of prenatal diagnosis during 2009–2021. A total of 4,932 couples at risk and 4,946 fetal specimens, including fetal blood (5.6%), amniotic fluid (92.3%), and chorionic villus samples (2.2%) were analyzed. Identification of mutations causing hemoglobinopathies was carried out by PCR-based methods. Maternal contamination was monitored by analysis of the D1S80 VNTR locus.

Results

Among 4,946 fetal specimens, 12 were excluded because of poor PCR amplification, maternal contamination, non-paternity, and inconsistency of the results of the fetuses and parents. Breakdown of 4,934 fetuses revealed 3,880 (78.6%) at risk for the three severe thalassemia diseases, including β-thalassemia major, Hb E-β-thalassemia, and homozygous α0-thalassemia, 58 (1.2%) at risk for other α-thalassemia diseases, 168 (3.4%) at risk for β+-thalassemia, 109 (2.2%) at risk for high Hb F determinants, 16 (0.3%) at risk for abnormal Hbs, and 294 (6.0%) with no risk of having severe hemoglobinopathies. The parents of 409 (8.3%) fetuses had inadequate data for fetal risk assessment. Overall, we encountered unnecessary prenatal diagnostic requests for 645 (13.1%) fetuses.

Conclusions

The frequency of unnecessary prenatal diagnosis was high. This could lead to unnecessary risk of complications associated with fetal specimen collection, psychological impacts to the pregnant women and their families, as well as laboratory expenses and workload.
Swine intestinal segment perfusion model for the evaluation of nutrients bioaccessibility
Authors: Dell’Anno Matteo , Acocella Fabio , Riccaboni Pietro , Recordati Camilla , Bongiorno Elisabetta , Rossi Luciana
Published: April 2023

Nutrition science requires more science-based evidences for the development of effective functional diets. To reduce animals for experimental purposes innovative reliable and informative models, simulating the complex intestinal physiology, are needed. The aim of this study was to develop a swine duodenum segment perfusion model for the evaluation of nutrient bioaccessibility and functionality across time. At the slaughterhouse, one sow intestine was harvested following Maastricht criteria for organ donation after circulatory death (DCD) for transplantation purposes. Duodenum tract was isolated and perfused in sub-normothermic conditions with heterologous blood after cold ischemia induction. Duodenum segment perfusion model was maintained under controlled pressure conditions through extracorporeal circulation for 3 hours. Blood samples from extracorporeal circulation and luminal content samples were collected at regular intervals for the evaluation of glucose concentration by glucometer, minerals (Na+, Ca2+, Mg2+, K+) by ICP-OES, lactate-dehydrogenase and nitrite oxide by spectrophotometric methods. Dacroscopic observation showed peristaltic activity caused by intrinsic nerves. Glycemia decreased over time (from 44.00±1.20 mg/dL to 27.50±0.41;p< 0.01), suggesting glucose utilization by the tissue confirming the organ viability in line with histological examinations. At the end of the experimental period, intestinal mineral concentrations were lower than their level in blood plasma suggesting their bioaccessibility (p< 0.001). A progressive increase of LDH concentration over time was observed in the luminal content probably related to a loss of viability (from 0.32±0.02 to 1.36±0.02 OD;p< 0.05) confirmed by histological findings that revealed a de-epithelization of the distal portion of duodenum. Isolated swine duodenum perfusion model satisfied the criteria for studying bioaccessibility of nutrients, offering a variety of experimental possibilities in line with 3Rs principle.
Numerical modelling of loose top coal and roof mass movement for a re-mined seam using the top coal caving method
Authors: Wang Shuai , Zhang Chunhua , He Feng , Yang Yu
Published: April 2023

The re-mined face using top coal caving system is the most applicable method for recovering the remaining reserves of a previous partially-mined thick coal seam. However, this mining method may encounter the problems of low recovery and unpredicted geological conditions. A numerical model is developed using PFC2D for studying the movement of top coal mass and development of coal-rock mass interface at a longwall top coal caving re-mined face. The re-mined face advances in the lower seam below the upper solid coal pillar, previous entries and gob. A theoretical analysis according to the unsteady flow model is developed to calculate the proper time duration of caving operation. The results showed that the top coal to be recovered through the caving window before the initiation of caving operation is a partial spheroid-shaped geometry. The boundary between the coal and rock mass then develops to a funnel-shaped coal-roof interface as the caving operation continues. The top coal recovery is 98.1%, 77.1% and 70.5% for caving operations below the solid coal, entries and gob area in the upper seam, respectively. The proper timing of caving and interval of caving operation is important for obtaining a high coal recovery. Good agreement is achieved between the proposed model and the improved Boundary-Release model for short of B-R model. The study in this work may provide reference for the safety and efficiency of the extraction of the longwall top coal caving re-mined face.