bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the feasibility, acceptability, and impact of Group Antenatal Care at the health post level on continuation in antenatal care and facility based delivery in Ethiopia using a cluster randomized stepped-wedge design: Study protocol
Authors: Yallew Walelegn W. , Fasil Rediet , Berhanu Della , Wolde Konjit , Teshite Dedefo , Sethi Reena , Yenokyan Gayane , Woldemariam Yenealem , Suhowatsky Stephanie , Hyre Anne , Noguchi Lisa , Worku Alemayehu
Published: April 2024

Background Adequate antenatal care (ANC) and facility-based delivery are linked to improved maternal and neonatal outcomes. Adequate antenatal care attendance and facility birth rates are increasing in Ethiopia but remain well below national goals and global recommendations. Group ANC (G-ANC), when implemented at higher level facilities, is associated with improved quality and experience of ANC, and increased ANC retention and facility-based delivery. The objectives of the study are to assess the feasibility, acceptability, and impact of G-ANC implemented at lower-level facilities (health posts) on ANC continuation and facility-based delivery. Methods G-ANC will first be piloted in five purposively selected health posts. The study will then use a stepped-wedge design in 36 health posts under six health centers, with randomization of the order of the start of the intervention done at the health center level (clusters). The design will include three time periods: first is a six-month control period with no G-ANC implementation, followed by another six months period where G-ANC will be introduced in half (n=18) of the study health posts, then final six months where G-ANC will be implemented in the remaining 18 health posts. Quantitative and qualitative data collection approaches will be used. The study has “pause and reflect” points designed to iterate on the intervention before rolling out to the next set of sites. Qualitative research will be conducted using in-depth interviews with pregnant women, health care workers, facility managers, and regional health managers. 770 women will be enrolled across all phases. Conclusions The study will inform decision makers locally and globally on whether G-ANC is a feasible service delivery model at the health post level. Effectiveness of G-ANC at increasing ANC retention and facility-based delivery will be reported, as well as its acceptability to pregnant women and Health Extension Workers. Registration NCT05054491, ClinicalTrials.gov (September 23rd 2021).
Our Language, Their Language. Once Again about the Text Variants of Czesław Miłosz’s “Campo Dei Fiori”
Authors: Wołk Marcin
Published: April 2024

English version. Original issue: “Archiwum Emigracji” 2011, no. 1–2 (14–15)https://apcz.umk.pl/AE/article/view/AE.2011.002
Transboundary movements of plastic waste from EU countries as a constraint for sustainability
Authors: Baran Bernadeta
Published: April 2024

Motivation: In the face of contemporary environmental and economic challenges, a transition to more sustainable global plastics economy is crucial. Countries are implementing circular economy solutions, but one of the common problems is so called “waste tourism” — export of plastic waste to other countries, often less developed. It contributes to global environmental problems but frequently surfaces also as inefficient resource management/trade and an ethical question as well. Transboundary movements of plastic waste from EU countries should be based on the principles set out in the Basel Convention which entail minimizing and disposing all kind of waste in an environmentally sound manner, minimizing the amount of waste transported and treating and disposing it as close as possible to its place of origin. Unfortunately, European plastic waste is exported in large quantities, often to less developed countries and not processed in accordance with European standards.Aim: This paper aims to identify the volume and directions of UE countries export patterns of plastic waste, its impact on the Sustainable Development Goals and trends in global and EU rules on transboundary plastic waste movements. The considerations are based, to a great extent, on literature on the subject-matter and secondary data, i.e. export data under the trade code 3915 (Waste, pairings and scrap of plastics) derived from the UN Comtrade and Eurostat Database, SDGs data derived from Sustainable Development Report 2022 and UN database and main legal basis for the international trade in plastic waste (the Basel Convention with its recent amendments) and its trends.Results: EU countries are still the leaders in exporting plastic waste, making it difficult to achieve the 12th SDG. Changes to the Basel Convention have not significantly affected the volume and destinations of EU plastic waste exports. They organize the categories of plastic waste but still leave an ample room for undesirable activities. Although the EU’s proposals are more restrictive, the most desirable solution is a complete ban on the export of plastic waste by EU countries outside the EU.
Udział polskich delegacji w Światowych Kongresach Historii Gospodarczej w latach 1990–2022
Authors: Franaszek Piotr , Bębnowski Damian
Published: April 2024

Przejawem kryzysu polskiej historiografii gospodarczej po 1989 r. jest m.in. niska aktywność rodzimych badaczy na Światowych Kongresach Historii Gospodarczej, organizowanych cyklicznie przez Międzynarodowe Stowarzyszenie Historii Gospodarczej (International Economic History Association, IEHA). W artykule zaprezentowano frekwencję i dorobek przedstawicieli polskich ośrodków naukowych na dziesięciu kongresach IEHA w latach 1990– 2022. Studium wpisuje się w badania z zakresu intelektualnej historii historiografii gospodarczej. W analizowanym okresie krajową naukę reprezentowało na światowym forum przeciętnie 12 osób, co nie odzwierciedlało jej potencjału. Tym niemniej tematyka prezentowanych referatów wpisywała się w zasadnicze trendy nauki światowej.
Traction with fraction: Strategic IS management in SMEs through Fractional CIOs
Authors: Kratzer Simon , Westner Markus , Strahringer Susanne
Published: April 2024

Small and medium-sized enterprises (SMEs) increasingly need to manage information technology (IT) effectively in order to remain competitive. However, compared to larger organizations, SMEs often face challenges in terms of resources and employer attractiveness, and regularly do not have the need to employ a Chief Information Officer (CIO) on a full-time basis. To address this issue, a growing number of global experts have begun to provide CIO services on a part-time basis for multiple clients simultaneously. This approach allows SMEs to tap into the expertise of experienced IT leaders at a fraction of the cost and without committing to long-term arrangements. While these professionals, known as “Fractional CIOs”, have proven their value in the field, there has been a lack of academic research on this emerging trend. Therefore, we carried out a comprehensive research project between 2020 and 2023, involving 62 Fractional CIOs from 10 countries. The research produced a definition, different types of engagements, and success factors for Fractional CIOs and their engagements. This paper summarizes these findings for a wider audience of academics and practitioners.
Should Bank Stress Tests Be Fair?
Authors: Glasserman Paul , Li Mike
Published: April 2024

Regulatory stress tests have become one of the main tools for setting capital requirements at the largest U.S. banks. The Federal Reserve uses confidential models to evaluate bank-specific outcomes for bank-specific portfolios in shared stress scenarios. As a matter of policy, the same models are used for all banks, despite considerable heterogeneity across institutions; individual banks have contended that some models are not suited to their businesses. Motivated by this debate, we ask, what is a fair aggregation of individually tailored models into a common model? We argue that simply pooling data across banks treats banks equally but is subject to two deficiencies: it may distort the impact of legitimate portfolio features, and it is vulnerable to implicit misdirection of legitimate information to infer bank identity. We compare various notions of regression fairness to address these deficiencies, considering both forecast accuracy and equal treatment. In the setting of linear models, we argue for estimating and then discarding centered bank fixed effects as preferable to simply ignoring differences across banks. We also discuss extensions to nonlinear models.

This paper was accepted by Kay Giesecke, finance.

Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2022.02060 .
WHAT RESEARCH TELLS US (THE SCIENCE BIT)
Authors: Jozwiak Gabriella , Fitzpatrick Anne , Halpenny Ann Marie
Published: April 2024

Gabriella Jozwiak looks more closely at a study by Anne Fitzpatrick and Ann Marie Halpenny, from the School of Social Sciences, Law and Education at Technological University Dublin, which investigated the benefits of intergenerational learning.
Avian influenza vaccine supply chain in Quang Ninh province, Vietnam, 2021
Authors:   Regional Animal Health Office Number 2, Department of Animal Health, Hai Phong city 180000, Vietnam, Tran Trong Duc , Sukmak Manakorn ,   Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand, Phimpraphai Waraphon ,   Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand, Padungtod Pawin ,   Emergency Center for Transboundary Animal Diseases, FAO Country Office for Vietnam, Hanoi 100000, Vietnam, Prarakamawongsa Tippawon ,   Bureau of Disease Control and Veterinary Service, Department of Livestock Development, Bangkok 10400, Thailand, Pham Long Thanh ,   Epidemiology Division, Department of Animal Health, Hanoi 100000, Vietnam, Truong Minh Van ,   Regional Animal Health Office Number 2, Department of Animal Health, Hai Phong city 180000, Vietnam, Kasemuwan Suwicha ,   Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
Published: April 2024

Highly pathogenic avian influenza (HPAI) is a zoonotic disease that can affect both poultry and humans. Since 2005, the Vietnam government has implemented a national vaccination campaign to prevent the spread of avian influenza (AI). In 2021, the first outbreak of HPAI H5N8 was reported in a chicken farm in Quang Ninh province. To understand the stakeholders linked to the AI campaign, and their roles within the vaccine supply chain, we conducted a cross-sectional study from November 2021–January 2022. We purposively selected 114 participants, including 71 poultry farmers using HPAI vaccines, 16 veterinary drug store owners, 18 commune animal health workers (CAHWs), 8 staff from the Centers for Agricultural Services (ATSCs), and one vaccine distributor who were interviewed face-to-face using a structured questionnaire. Three HPAI vaccines (H5N1 clade 1 & 2.3.2.1, H5N1 clade 2.3.4 and H5N1 clade 2.3.2.1b) were used, and they were effective against the locally circulating virus strains. Distributors stored vaccines at the required temperature and transported them in appropriate vehicles. Vaccines remained in the supply chain for 3–5 months within their 12-month shelf-life period. The free government vaccination campaign, implemented by CAHWs, and administered by the ATSCs, reached 61% of small-scale poultry farms with a 1.21% vaccine wastage rate. Large-scale poultry farms followed the national campaign but paid a fee for the vaccines. We recommend expanding the support for AI vaccination to increase the vaccination rate among large-scale poultry farms, selecting higher efficacy seed vaccines, and that smaller dose vaccine vials are available for cost-effective vaccination.
A Study of the Feed Management Practices of Private Elephant Camps in Chiangmai Province
Authors:   Department of Plant and Soil Sciences, Faculty of Agriculture, Chiang Mai University, Suriyong Sangtiwa , Sringarm Korawan ,   Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Krittigamas Nattasak ,   Department of Plant and Soil Sciences, Faculty of Agriculture, Chiang Mai University, Bansiddhi Pakkanut ,   Department of Companion Animals and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand,   Center of Elephant and Wildlife Health, Chiang Mai University Animal Hospital, Chiang Mai, Thailand
Published: April 2024

Captive elephant must be properly fed to meet their nutritional demands, supporting optimal growth and development to achieve their providing conservation through tourism. This study aimed to revision of the feed management practices of private elephant camps in Chiangmai province. An archival review and in depth interviews of key informants involving the elephant camps owners or managers located in Chiangmai were conducted. The interview showed that staple roughage of most camps was hybrid napier grass while once is sweet corn soilage. The majority of the large elephant camps with more than 30 elephants which were fed by the camp. Elephants' dietary requirements were addressed under the supervision of veterinarians. The delivery of roughage of large camps coincided with small camp size which the middle man played an important role for gathering, harvesting, transporting and feeding the roughage to the elephants raised in the camps. The diary was fed 10 percent of their weight or about 100-120 kg roughage per individual. Most of the camp, roughage was divided into four to five meals each day. The study's findings for the tiny elephant camps' food management revealed that including elephants in greeting activities for eco-tourists so that they can eat while traveling the hiking trails. The camp also bought bananas and sugar cane from local farmers to sell to visitors for the purpose of feeding the elephants. However, a COVID-19 outbreak that occurred during the research period prevented the elephant camp from earning money from the tourism sector, which reduced the amount of food available.
Effects of hydrogen peroxidase-inactivated vaccine against Streptococcus agalactiae infection in red tilapia (Oreochromis sp.) via different routes of administration
Authors:   Department of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho 900000, Vietnam, Nhu Truong Quynh , Bich Tran Ngoc ,   Department of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho 900000, Vietnam, Duy Dang Thanh ,   Department of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho 900000, Vietnam, Hang Bui Thi Bich ,   Department of Aquatic Pathology, College of Aquaculture, Can Tho University, Can Tho 900000, Vietnam, Hang Nguyen Thi Thu ,   Department of Aquatic Pathology, College of Aquaculture, Can Tho University, Can Tho 900000, Vietnam, Ngu Nguyen Trong ,   Department of Animal Sciences, College of Agriculture, Can Tho University, Can Tho 900000, Vietnam, Phuong Nguyen Thanh ,   Department of Aquatic Pathology, College of Aquaculture, Can Tho University, Can Tho 900000, Vietnam
Published: April 2024

Hydrogen peroxidase-inactivated vaccines have recently developed in controlling infectious diseases in aquaculture. The present study aimed to compare the efficacy of the hydrogen peroxidase-inactivated Streptococcus agalactiae vaccine via different delivery routes (injection, immersion, and oral administration) in red tilapia (Oreochromis sp.) without using adjuvant. Fish were randomly divided into 4 groups including G1: Control treatment (without vaccine), G2: vaccine-based diet (oral administration), G3: vaccinated by immersion and G4: vaccinated by injection. After 6 weeks of the experiment, fish were intraperitoneally injected with S. agalactiae and the mortality was recorded in 14 days. The results showed that lysozyme activity was differentially increased according to the delivery routes of vaccine, organs and time of sampling. However, the specific antibody levels in all vaccinated groups were only increased in week 6 post-vaccination. After the challenge test with S. agalactiae, the serum lysozyme levels in G3 and G4 were significantly higher than the control group (G1), while the total white blood cells and specific antibody levels were significantly increased in G2 and G4 compared to the control (G1). Similarly, the hydrogen peroxidase-inactivated vaccine statistically reduced the cumulative mortality in G2 (35.29%) and G4 (28.95%) compared to G1 (44.12%) after injected with the S. agalactiae. These results showed that the vaccine delivery routes by oral administration or injection may decrease the pathogen and show better protection for red tilapia than the immersion method. Further studies will be investigated to improve the efficacy of hydrogen peroxidaseinactivated vaccine via using different adjuvants.
Evaluation of Scoring Atopic Dermatitis (SCORAD) and scratching behavior in BALB/c mice treated with house dust mite immunotherapy
Authors:   Doctoral Program of Medical Science, Faculty of Medicine, Universitas Airlangga, Surabaya, 60286, Indonesia, Anggraeni Sylvia , Triesayuningtyas Dinar Chieko ,   Department of Dermatology and Venereology, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, 60286, Indonesia, Endaryanto Anang ,   Department of Pediatrics, Faculty of Medicine Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, 60286, Indonesia, Prakoeswa Cita Rosita Sigit ,   Department of Dermatology and Venereology, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, 60286, Indonesia
Published: April 2024

Allergen specific immunotherapy controls the reaction and builds immunological tolerance by giving an allergen in escalating doses. Research on immunotherapy in atopic dermatitis (AD) mouse model offers a new perspective on the approach of treatment in AD. This was an experimental study of 33 male BALB/c mice, 6-8 weeks old, divided into 3 groups (control, AD model, and house dust mite/HDM immunotherapy). The mice received spray and patch containing allergen extract of Dermatophagoides pteronyssinus. Immunotherapy was injected subcutaneously in increasing doses. The evaluation of SCORAD and scratching behavior were observed at the end of the treatment on day 93. The SCORAD of the model group that received HDM allergen had a mean of 1.27 ± 0.467 and the immunotherapy group had a mean of 0.36 ± 0.505. There were significant differences between the groups. The model group had a mean of 5.18 ± 4.119 and the immunotherapy group had mean of 1.55 ± 1.293. The statistical analysis showed that there were significant differences between control group and model group, as well as model group and immunotherapy group. Interobserver agreement was assessed and showed substantial agreement for SCORAD (ĸ = 0.613 and p < 0.001) and scratching evaluation (ĸ = 0.714 and p < 0.001). House dust mite immunotherapy significantly reduced SCORAD and scratching behavior in BALB/c mice compared to placebo groups.
Evaluation of essential oil supplementation as a feed additive on rumen fermentation characteristics and methane mitigation in ruminants: A meta-analysis
Authors:   Department of Nutrition and Feed Technology, IPB University, Bogor 16680, West Java, Indonesia, Permata Dessy , Wiryawan Komang G. ,   Department of Nutrition and Feed Technology, IPB University, Bogor 16680, West Java, Indonesia, Jayanegara Anuraga ,   Department of Nutrition and Feed Technology, IPB University, Bogor 16680, West Java, Indonesia
Published: April 2024

This research aimed to investigate the use of essential oils (EO) in vivo as a feed additive on rumen fermentation characteristics and methane gas through a meta-analysis approach by integrating various related studies. The data analyzed came from 21 journals, 26 studies, and 73 data points from 2007–2021, which were tabulated using Microsoft Excel and analyzed with SAS using the mixed model method. The results of EO supplementation exhibited a significant (P < 0.01) decrease in ammonia concentration, Diplodinium population, and methane gas production, as well as a significant (P < 0.05) reduction of acetate proportion and Dasytrica populations. In contrast, EO supplementation had a significant effect (P < 0.01) on final body weight increase. The crude protein tended to increase (P < 0.1) with EO supplementation. In conclusion, EO supplementation as a feed additive can positively affect rumen fermentability and methane gas production.
Demyelinating neuropathy in patients with hepatitis B virus: A case report
Authors: Yan Xiao-Xiao , Huang Jin , Lin Jing
Published: April 2024

BACKGROUND

Hepatitis B rarely leads to demyelinating neuropathy, despite peripheral neuropathy being the first symptom of hepatitis B infection.

CASE SUMMARY

A 64-year-old man presented with sensorimotor symptoms in multiple peripheral nerves. Serological testing showed that these symptoms were due to hepatitis B. After undergoing treatment involving intravenous immunoglobulin and an antiviral agent, there was a notable improvement in his symptoms.

CONCLUSION

Although hepatitis B virus (HBV) infection is known to affect hepatocytes, it is crucial to recognize the range of additional manifestations linked to this infection. The connection between long-term HBV infection and demyelinating neuropathy has seldom been documented; hence, prompt diagnostic and treatment are essential. The patient's positive reaction to immunoglobulin seems to be associated with production of the antigen-antibody immune complex.
Cemented vertebra and adjacent vertebra refractured in a chronic kidney disease-mineral and bone disorder patient: A case report
Authors: Zhang Ti-Dong , Cao Shuai , Ren Hui-Yong , Li Yu-Min , Yuan Yi-Ming
Published: April 2024

BACKGROUND

Although percutaneous vertebral augmentation (PVA) is a commonly used procedure for treating vertebral compression fracture (VCF), the risk of vertebral refracture should be considered. Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a systemic disease of mineral and bone metabolism. It is associated with an increased risk of fracture. Few studies have reported the use of PVA in patients with CKD-MBD. We herein report a rare case wherein the cemented vertebra and the adjacent vertebra refractured simultaneously in a CKD-MBD patient after PVA.

CASE SUMMARY

A 74-year-old man suffered from low back pain after taking a fall about 3 wk ago. According to physical examination, imaging and laboratory findings, diagnoses of T12 VCF, CKD-MBD, and chronic kidney disease stage 5 were established. He then received percutaneous vertebroplasty at T12 vertebra. Fourteen weeks later, he presented with T12 and L1 vertebral refractures caused by lumbar sprain. Once again, he was given PVA which was optimized for the refractured vertebrae. Although the short-term postoperative effect was satisfactory, he reported chronic low back pain again at the 3-month follow-up.

CONCLUSION

It is necessary that patients with CKD-MBD who have received PVA are aware of the adverse effects of CKD-MBD. It may increase the risk of vertebral refracture. Furthermore, the PVA surgical technique needs to be optimized according to the condition of the patient. The medium- and long-term effects of PVA remain uncertain in patients with CKD-MBD.
Thoracic spinal cord injury and paraplegia caused by intradural cement leakage after percutaneous kyphoplasty: A case report
Authors: Mao Zi , Xiong Zhi-Hong , Li Jun-Feng
Published: April 2024

BACKGROUND

Percutaneous kyphoplasty (PKP) is a pivotal intervention for osteoporotic fractures, pathological vertebral compression fractures, and vertebral bone tumors. Despite its efficacy, the procedure presents challenges, notably complications arising from intradural cement leakage. Timely and accurate diagnosis, coupled with emergent intervention is imperative to improve patient prognosis. This case report illuminates the intricacies and potential complications associated with PKP, emphasizing the critical need for vigilant monitoring, prompt diagnosis, and immediate intervention to mitigate adverse outcomes.

CASE SUMMARY

A 58-year-old male patient, experiencing a T7 osteoporosis-related pathological compression fracture, underwent PKP at a local hospital. Two weeks post-procedure, the patient developed paraplegic and dysuric symptoms, necessitating emergency decompression surgery. Gradual improvement was achieved, marked by the restoration of muscle strength, sensation, and mobility.

CONCLUSION

PKP Intradural cement leakage following PKP is unusual and potentially fatal. Prompt imaging examinations, urgent evaluation, and the decompression surgery are essential, which help alleviate symptoms associated with spinal damage, markedly improving the overall prognosis.
A Comprehensive Review on Nanoplex Nanotechnology Strategies
Authors: Rushikesh* Patil , Devadatta Salve , Bharati Garale , Ganesh Shewalkar , Laxmikant Borse
Published: April 2024

ABSTRACT: One strategy used to get around the problems with conventional medication delivery systems is the use of nanotechnology based on the creation and growth of nanostructures. The newest development in nanotechnology is the creation of Nanoplex. A polyelectrolyte with an oppositely charged drug nanoparticle forms a complex known as a nanoplex. Both cationic and anionic medicines combine with polyelectrolytes that have opposing charges to produce complexes. The yield of Nanoplex is higher and the complexation efficiency is better when compared to other nanostructures. Additionally, nanoplex are simpler to make. Using scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and dialysis investigations, the production yield, complexation efficiency, drug loading, particle size, and zeta potential of nanoplex formulation are all evaluated. Nanoplex have a wide range of uses in various domains, including cancer treatment, medication delivery to the brain, drug delivery via genes, and drug delivery via proteins and peptides.
Allomorphy, morphological operations and the order of Slavic verb-prefixes
Authors: Quaglia Stefano , Simonović Marko , Yudina Svitlana Antonyuk , Arsenijević Boban
Published: April 2024

abstract: Slavic verbal prefixes are traditionally divided into lexical and superlexical types. Lexical prefixes are base-generated below the verb, while superlexical prefixes are generated within the verb's functional projection. However, this analysis incorrectly predicts their linearization. We propose that all verbal prefixes correspond to argument-structural effects, generated as heads of a voice projection. Our PF analysis follows Embick & Noyer (2001), with heads linearizing bottom-up, accompanied by local dislocation. Default dislocation is string-vacuous; inversion occurs only when the head participates in allomorphic realization. Strict implementation of this algorithm precisely yields the observed surface order.
Multi-mode stable, high peak power Nd:YAG laser device for laser cleaning
Authors: Qi Yunxuan , Zhang Sasa , Ye Zhibin , Jiang Shu
Published: April 2024

High average power and peak power solid-state lasers are of great interest in the field of laser cleaning. In this research, a high peak power laser with over 400 W average power using a multi-mode stable resonator in a diode-pumped Nd:YAG master oscillator power amplifier has been demonstrated. A maximum peak power over 1.08 MW was achieved at a repetition frequency of 5 kHz. Delivery fiber with a 400 µm core diameter was utilized for flexible laser transmission. A prototype of the laser cleaning system was developed and inspiring application effects for paint and mold cleaning were achieved.
Laser-induced shock wave two-dimensional extraction technology based on a beam deflection method
Authors: Sun HaoHan , Yin YunSong , Liu XiaoDong , Yi Wen , Liu RuiBin
Published: April 2024

This paper introduces a method for analyzing the spatiotemporal progression of laser-induced shock waves using the beam deflection technique. This method allows for the accurate measurement of the shock wave evolution and can replace high-speed cameras. The results demonstrate the detection signals at various distances and energies, as well as the extraction and reconstruction of the shock wave velocities and propagation trajectories. The characteristic velocities of the shock waves propagating in air from various metals and energetic materials were measured and compared with the results obtained from high-speed cameras. The study also predicts the macroscopic detonation velocity of energetic materials based on the characteristic velocity. Overall, this approach offers a reliable and cost-effective method for studying the shock waves and has potential applications in various fields.
Examining the role of magnetic fields in plasma behavior and surface evolution of a Mg alloy with varied irradiances in a femtosecond laser treatment
Authors: Dawood Asadullah , Khan Muhammad Asad , Bashir Shazia , Ayub Ambreen , Hayat Asma , Sanderson Joseph H. , Chishti Naveed Ahmed
Published: April 2024

This paper reports the effect of a magnetic field on plasma parameters and surface structuring of the Mg alloy after laser irradiation. Femtosecond pulses of a Ti:sapphire laser system (800 nm, 35 fs, 1 KHz) are employed as the source of irradiation at various irradiances ranging from 0.011PW/cm2 to 0.117PW/cm2 to generate ablated Mg-alloy plasma. A transvers magnetic field (TMF) of strength 1.1 Tesla is employed to confine laser generated Mg plasma. All the measurements are performed with and without TMF. The two plasma parameters, i.e., excitation temperature (Texc) and electron number density (n
e
) of Mg plasma, have been evaluated by laser-induced breakdown spectroscopy (LIBS) analysis. It is observed that the values of Texc and n
e
of laser produced plasma (LPP) of the Mg alloy are higher in the presence of a magnetic field as compared to the field free case. Both show initially an increasing trend with increasing laser irradiance and after attaining their respective maxima a decreasing trend is observed with the further increase of irradiance. The magnetic confinement validity is confirmed by analytically evaluating thermal beta (β
t
), directional beta (β
d
), confinement radius (R
b
), and diffusion time (t
d
) for LPP of the Mg alloy. To correlate the LPP parameters of the Mg alloy with surface modifications a field emission scanning electron microscope (FE-SEM) analysis is performed. It was revealed that structures like laser-induced periodic surface structures (LIPSSs), agglomerates, islands, large sized bumps, along with channels and multiple ablative layers are observed. Distinct and well-defined surface structuring is observed in the presence of TMF as compared to the field free case. It is concluded that by applying an external magnetic field during laser irradiation, controlled material surface structuring is possible for fabrication of nanogratings and field emitters where spatial uniformity is critically important.
Efficient ultra-broadband low-resolution astrophotonic spectrographs
Authors: Gatkine Pradip , Sercel Greg , Jovanovic Nemanja , Broeke Ronald , Ławniczuk Katarzyna , Passoni Marco , Balakrishnan Ashok , Bidnyk Serge , Yin Jielong , Jewell Jeffrey , Wallace J. Kent , Mawet Dimitri
Published: April 2024

Broadband low-resolution near-infrared spectrographs in a compact form are crucial for ground- and space-based astronomy and other fields of sensing. Astronomical spectroscopy poses stringent requirements including high efficiency, broad band operation (> 300 nm), and in some cases, polarization insensitivity. We present and compare experimental results from the design, fabrication, and characterization of broadband (1200 - 1650 nm) arrayed waveguide grating (AWG) spectrographs built using the two most promising low-loss platforms - Si3N4 (rectangular waveguides) and doped-SiO2 (square waveguides). These AWGs have a resolving power (λ/Δλ) of ∼200, free spectral range of ∼ 200-350 nm, and a small footprint of ∼ 50-100 mm2. The peak overall (fiber-chip-fiber) efficiency of the doped-SiO2 AWG was ∼ 79% (1 dB), and it exhibited a negligible polarization-dependent shift compared to the channel spacing. For Si3N4 AWGs, the peak overall efficiency in TE mode was ∼ 50% (3 dB), and the main loss component was found to be fiber-to-chip coupling losses. These broadband AWGs are key to enabling compact integrations such as multi-object spectrographs or dispersion back-ends for other astrophotonic devices such as photonic lanterns or nulling interferometers.
E-PVT: enhanced position-velocity-time scheduler for computer-controlled optical finishing with comprehensive considerations of dynamics constraints, continuity and efficiency
Authors: Ke Xiaolong , Fan Jiacheng , Wang Tianyi , Huang Lei , Zhu Yi , Austin Corey , Choi Heejoo , Kang Hyukmo , Negi Vipender , Kim Daewook , Zhang Zili , Wang Chunjin , Chen Shuixuan , Bouet Nathalie , Idir Mourad
Published: April 2024

Deterministic computer-controlled optical finishing is an essential approach for achieving high-quality optical surfaces. Its determinism and convergence rely heavily on precise and smooth motion control to guide the machine tool over an optical surface to correct residual errors. One widely supported and smooth motion control model is position-velocity-time (PVT), which employs piecewise cubic polynomials to describe positions. Our prior research introduced a PVT-based velocity scheduling method, demonstrating sub-nanometer level convergence in ion beam figuring (IBF) processes. However, three challenges remained. Firstly, this method relies on quadratic programming, resulting in computational intensiveness for dense tool paths. Secondly, the dynamics constraints and velocity and acceleration continuities are not comprehensively considered, limiting the full potential of PVT-based control. Thirdly, no compensation mechanism existed when dynamics constraints are exceeded. In this study, in response to these challenges, we proposed the Enhanced PVT (E-PVT) method, reducing the time complexity from O(n3) to O(n) while fully addressing dynamics constraints and continuities. A novel compensation method utilizing particle swarm optimization was proposed to address situations where dynamics constraints might be exceeded while maintaining the overall processing efficiency. Validation through simulation and experimentation confirmed the improved performance of E-PVT.
Hybrid integrated optical chaos circuits with optoelectronic feedback
Authors: Wang Yisi , Wu Zheng , Li Boyu , Chen Jisun , Shen Lijie , Yang Huihui , Feng Yuan , Chen XiangFei , Li Mi
Published: April 2024

A chip-scale chaotic laser system with optoelectronic delayed feedback is proposed and analyzed by numerical simulation. This chip eliminates the need for bulky delay components such as long optical fibers, free propagation and external cavities, relying solely on internal devices and waveguides to achieve feedback delay. This approach simplifies integration, maintaining a compact chip size. According to the results, the chip-scale system exhibits rich dynamics, including periodicity, quasi-periodicity, and chaotic states. Chaos resembling Gaussian white noise is achieved with picosecond-level delay time, highlighting the complexity of chip-scale signals. Furthermore, time delay signature (TDS) concealment is enhanced with a short delay comparable to the inverse bandwidth τ, albeit at a cost of sacrificing chaotic signal complexity. Applying the photonic integrated circuits to practical applications, 1 Gbps back-to-back communication transmission is feasible. Results demonstrate low bit error rates (BERs) for authorizers (<10−6) and high BERs for eavesdroppers (>10−2), ensuring communication confidentiality and chaotic synchronization. Lastly, preliminary experiments validate the feasibility. Our theoretical work has demonstrated the feasibility of hybrid integrated optical chaos circuits with optoelectronic feedback based on photonic wire bonding, which can provide a stable and flexible integrated chaos source.
High power, frequency agile comb spectroscopy in the mid-infrared enabled by a continuous-wave optical parametric oscillator
Authors: Heiniger A. T. , Cich M. J. , Long D. A.
Published: April 2024

While mid-infrared optical frequency combs have been widely utilized in areas such as trace gas sensing, chemical kinetics, and combustion science, their relatively low power has limited sensitivities and led to correspondingly long acquisition times. We have developed a new approach in which an electro-optic frequency comb is utilized to pump a continuous-wave singly-resonant optical parametric oscillator in order to spectrally translate the comb into the mid-infrared (2.19 µm and 4.00 µm) with watt-level powers. Through the use of electro-optic combs produced via chirped waveforms we have produced mid-infrared combs containing up to 2400 comb teeth. We show that an ultraflat comb can be generated on the non-resonant idler and we use these combs to perform high resolution spectroscopy on methane. In addition, we describe the underlying theory of this method and demonstrate that phase matching should allow for combs as broad as several THz to be spectrally translated to the mid-infrared. The high power and mutual coherence as well as the relatively low complexity of this approach should allow for broad application in areas such as chemical dynamics, quantum information, and photochemistry.
Optical fiber bundle differential compressive imaging
Authors: Jiang Zhixiang , Wen Ya , Song Lipei , Li Da , Zhao Xing
Published: April 2024

We present a differential compressive imaging method for an optical fiber bundle (OFB), which provides a solution for an ultrathin bend-resistant endoscope with high resolution. This method uses an OFB and a diffuser to generate speckle illumination patterns. Differential operation is additionally applied to the speckle patterns to produce sensing matrices, by which the correlation between the matrices is greatly reduced from 0.875 to 0.0275, which ensures the high quality of image reconstruction. Pixilation artifacts from the fiber core arrangement are also effectively eliminated with this configuration. We demonstrate high-resolution reconstruction of images of 132 × 132 pixels with a compression rate of 12% using 77 fiber cores, the total diameter of which is only about 91 µm. An experimental verification proves that this method is tolerant to a limited degree of fiber bending, which provides a potential approach for robust high-resolution fiber endoscopy.
Application of femtosecond mode-locked SnTe thin films and generation of bound-state solitons
Authors: Chen Yueqian , Wu Zhitao , Xiao Peiyao , Xiao Wende , Liu Wenjun
Published: April 2024

In the realm of ultrafast laser technology, the exploration of two-dimensional materials as saturable absorbers (SA) has garnered significant research interest. Our research investigates the characteristics of SnTe thin films, a topological crystalline insulator material, as a potential saturable absorber for ultrafast lasers. Using the molecular beam epitaxy (MBE) technique, we analyze the films’ morphology and composition through atomic force microscopy (AFM) and successfully deposit SnTe epilayers on Au(111)/mica substrates. Through the utilization of SnTe-SA, an erbium-doped fiber laser is fabricated, demonstrating a pulse output with a width of 276 fs and a center wavelength of 1560 nm, highlighting the potential of SnTe films in manufacturing ultrafast optical devices. Additionally, tightly bound solitons with a soliton interval of 1.01 ps are observed, contributing to the exploration of soliton nonlinear dynamics.
Validated enhancement and temperature modulated absorbance of a WS2 monolayer based on a planar structure
Authors: Yuan Xueyong , Jiang Guangsheng , Liu Pingwei , Fu Qiang , Zhang Zhi , Liu Tianqi , Jiang Yuru , Zhao Weiwei , Wang Wenhui , Zhao Bei , Li Zejun , Liu Dan , Ni Zhenhua , Lu Junpeng
Published: April 2024

Transition-metal dichalcogenides (TMDCs), as emerging optoelectronic materials, necessitate the establishment of an experimentally viable system to study their interaction with light. In this study, we propose and analyze a WS2/PMMA/Ag planar Fabry–Perot (F–P) cavity, enabling the direct experimental measurement of WS2 absorbance. By optimizing the structure, the absorbance of A exciton of WS2 up to 0.546 can be experimentally achieved, which matches well with the theoretical calculations. Through temperature and thermal expansion strain induced by temperature, the absorbance of the A exciton can be tuned in situ. Furthermore, temperature-dependent photocurrent measurements confirmed the consistent absorbance of the A exciton under varying temperatures. This WS2/PMMA/Ag planar structure provides a straightforward and practical platform for investigating light interaction in TMDCs, laying a solid foundation for future developments of TMDC-based optoelectronic devices.
Controlling ultrafast laser writing in silica glass by pulse temporal contrast
Authors: Lei Yuhao , Wang Huijun , Shayeganrad Gholamreza , Svirko Yuri , Kazansky Peter G.
Published: April 2024

We demonstrate that the temporal contrast of femtosecond light pulses is a critical parameter in laser writing inside transparent dielectrics, allowing different material modifications. In particular, anisotropic nanopores in silica glass are produced by high-contrast of 107 femtosecond Yb:KGW laser pulses rather than low-contrast of 103 Yb fiber laser pulses. The difference originates in the fiber laser storing a third of its energy in a post-pulse of up to 200 ps duration. The absorption of this low-intensity fraction of the pulse by laser-induced transient defects with relatively long lifetime and low excitation energy, such as self-trapped holes, drastically changes the kinetics of energy deposition and the type of material modification. We also demonstrate that low-contrast pulses are effective in creating lamellar birefringent structures, possibly driven by a quadrupole nonlinear current.
Symmetric Non-Monochromatic Light as Reference in Fourier Transform Spectrometers
Authors: wen muqian
Published: April 2024

Fourier transform spectrometers typically use a presumed monochromatic reference source to track and correct errors in optical path difference changes. This paper will conduct a theoretical analysis to show that nonmonochromatic light sources with symmetric spectral profile can also be used as reference sources without adding any more errors. An experiment was carried out using a symmetric broadband SLED as reference light to measure the spectrum of some other SLED light sources to experimentally demonstrate this finding.
Measurement of atmospheric non-reciprocity effects for satellite-based two-way time-frequency transfer
Authors: Zeng Ting , Shen Qi , Cao Yuan , Guan Jian-Yu , Lian Meng-Zhe , Han Jin-Jian , Hou Lei , Lu Jian , Peng Xin-Xin , Li Min , Liu Wei-Yue , Wu Jin-Cai , Wang Yong , Yin Juan , Ren Ji-Gang , Jiang Hai-Feng , Zhang Qiang , Peng Cheng-Zhi , Pan Jian-Wei
Published: April 2024

Future optical clock networks will require high-precision optical time-frequency transfer between satellites and ground stations. However, due to atmospheric turbulence, satellite motion and time delay between the satellite–ground transmission links will cause spatial and temporal variations, respectively, resulting in the breakdown of the time-of-flight reciprocity on which optical two-way time-frequency transfer is based. Here, we experimentally simulate the atmospheric effects by two-way spatio-temporally separated links between two stationary terminals located 113 km apart and measure the effects for optical two-way time-frequency transfer. Our experiment shows that the effect on the link instability is less than 2.3×10−19 at 10,000 s. This indicates that when the link instability of satellite–ground optical time-frequency transfer is on the order of 10−19, it is not necessary to consider the atmospheric non-reciprocity effects.
Implementation of mobile-health technology is associated with five-year survival among individuals in rural areas of Indonesia
Authors: Maharani Asri , Sujarwoto  , Praveen Devarsetty , Oceandy Delvac , Tampubolon Gindo , Patel Anushka
Published: April 2024

There is an urgent need to focus on implementing cost-effective health interventions and policies to reduce the burden of cardiovascular disease in Indonesia. This study aims to evaluate whether a mobile technology–supported primary health care intervention, compared with usual care, would reduce the risk of all-cause mortality among people in rural Indonesia. Data were collected from 11,098 participants in four intervention villages and 10,981 participants in four control villages in Malang district, Indonesia. The baseline data were collected in 2016. All the participants were followed for five years, and the mortality data were recorded. Cox proportional hazard model was used to examine the association between the intervention and the risk of all-cause mortality, adjusted for the covariates, including age, gender, educational attainment, employment and marital status, obesity and the presence of diabetes mellitus. During the five-year follow-up, 275 participants died in intervention villages, compared with 362 in control villages. Participants residing in intervention villages were at 18% (95%CI = 4 to 30) lower risk of all-cause mortality. Higher education attainment and being married are associated with lower risks of all-cause mortality among respondents who lived in the control villages, but not among those living in the intervention villages. A mobile technology–supported primary health care intervention had the potential to improve the five-year survival among people living in villages in an upper-middle income country.
Using Monte-Carlo simulation to test predictions about the time-course of semantic and lexical access in reading
Authors: Perry Conrad
Published: April 2024

One of the main theoretical distinctions between reading models is how and when they predict semantic processing occurs. Some models assume semantic activation occurs after word-form is retrieved. Other models assume there is no-word form, and that what people think of as word-form is actually just semantics. These models thus predict semantic effects should occur early in reading. Results showing words with inconsistent spelling-sound correspondences are faster to read aloud if they are imageable/concrete compared to if they are abstract have been used as evidence supporting this prediction, although null-effects have also been reported. To investigate this, I used Monte-Carlo simulation to create a large set of simulated experiments from RTs taken from different databases. The results showed significant main effects of concreteness and spelling-sound consistency, as well as age-of-acquisition, a variable that can potentially confound the results. Alternatively, simulations showing a significant interaction between spelling-sound consistency and concreteness did not occur above chance, even without controlling for age-of-acquisition. These results support models that use lexical form. In addition, they suggest significant interactions from previous experiments may have occurred due to idiosyncratic items affecting the results and random noise causing the occasional statistical error.