bluuebunny/crossref_metadata_2025 huggingface dataset:
Preclinical evaluation of targeted therapies for central nervous system metastases
Authors: Pfeil Alexander J. , Hale Joshua D. , Zhang Tiger S. , Wakayama Kentaro , Miyazaki Isao , Odintsov Igor , Somwar Romel
Published: September 2024

The central nervous system (CNS) represents a site of sanctuary for many metastatic tumors when systemic therapies that control the primary tumor cannot effectively penetrate intracranial lesions. Non-small cell lung cancers (NSCLCs) are the most likely of all neoplasms to metastasize to the brain, with up to 60% of patients developing CNS metastases during the disease process. Targeted therapies such as tyrosine kinase inhibitors (TKIs) have helped reduce lung cancer mortality but vary considerably in their capacity to control CNS metastases. The ability of these therapies to effectively target lesions in the CNS depends on several of their pharmacokinetic properties, including blood–brain barrier permeability, affinity for efflux transporters, and binding affinity for both plasma and brain tissue. Despite the existence of numerous preclinical models with which to characterize these properties, many targeted therapies have not been rigorously tested for CNS penetration during the discovery process, whereas some made it through preclinical testing despite poor brain penetration kinetics. Several TKIs have now been engineered with the characteristics of CNS-penetrant drugs, with clinical trials proving these efforts fruitful. This Review outlines the extent and variability of preclinical evidence for the efficacy of NSCLC-targeted therapies, which have been approved by the US Food and Drug Administration (FDA) or are in development, for treating CNS metastases, and how these data correlate with clinical outcomes.
Fiscal and Monetary Policy Interactions in a Model with Low Interest Rates
Authors: Miao Jianjun , Su Dongling
Published: September 2024

We provide a new Keynesian model where entrepreneurs face uninsurable idiosyncratic investment risk and credit constraints. Government bonds provide liquidity services. Multiple steady states with positive values of public debt can be supported for a given permanent deficit-to-output ratio. The steady-state interest rates are lower than the economic growth rate, and public debt contains a bubble component. We analyze the determinacy regions of policy parameter space and find that a large set of monetary and fiscal policy parameters can achieve debt and inflation stability given persistent fiscal deficits both away from and at the zero interest rate lower bound. (JEL E12, E23, E31, E43, E52, E62, H63)
Ψυχαναγκαστικά καταναγκαστικά προβλήματα και προόβλεψή τους σε νεαρούς ενήλικες
Authors: Νισυραίου Άννα
Published: September 2024

Η Ψυχαναγκαστική Καταναγκαστική Διαταραχή (ΨΚΔ) εμφανίζει μεγάλη ετερογένεια στα συμπτώματά της, με πολλούς αιτιολογικούς παράγοντες να έχουν προταθεί για την εξήγησή της. Ανάμεσα σε αυτούς, έχουν προταθεί γνωστικοί παράγοντες είτε αυτόνομοι είτε ομαδοποιημένοι σε μοντέλα, όπως, για παράδειγμα, το μοντέλο των ψυχαναγκαστικών πεποιθήσεων, το μοντέλο των πυρηνικών διαστάσεων και το μοντέλο της συναισθηματική ρύθμισης. Όλα αυτά τα μοντέλα και οι παράγοντες έχουν βρεθεί να συσχετίζονται σημαντικά με συμπτώματα της ΨΚΔ, ενώ έχουν προταθεί ως προβλεπτικοί παράγοντες για την ανάπτυξη τέτοιων συμπτωμάτων. Ωστόσο, υπάρχει έλλειψη διαχρονικών μελετών, οι οποίες θα επέτρεπαν να μελετηθεί η προβλεπτική σχέση αυτών των παραγόντων με την ΨΚΔ. Η παρούσα διαχρονική έρευνα στοχεύει στη διερεύνηση της σχέσης αυτής σε φοιτητές πρώτων ετών σπουδών, λαμβάνοντας υπόψη τη ευπάθεια της περιόδου αυτής στην ευαισθησία για την ανάπτυξη της ΨΚΔ. Οι συμμετέχοντες ήταν 88 φοιτητές, οι οποίοι, σε διάστημα δυο ετών, συμμετείχαν σε τρεις μετρήσεις κατά την διάρκεια των σπουδών τους. Τα εργαλεία που χρησιμοποιήθηκαν περιελάμβαναν ερωτηματολόγια για την αποτίμηση γνωστικών παραγόντων όπως οι ψυχαναγκαστικές πεποιθήσεις, η συναισθηματική ρύθμιση και οι πυρηνικές διαστάσεις της ΨΚΔ, όπως η αποφυγή βλάβης και το αίσθημα μη πληρότητας. Τα αποτελέσματα, όσον αφορά την προβλεπτική ισχύ των γνωστικών μοντέλων, έδειξαν ότι μόνο το μοντέλο πυρηνικών διαστάσεων επέδρασε σημαντικά στα ΨΚ συμπτώματα. Ωστόσο, δεν βρέθηκε αιτιώδης σχέση μεταξύ του μοντέλου των πυρηνικών διαστάσεων και των συμπτωμάτων της ΨΚΔ. Η έρευνα παρέχει σημαντικές ενδείξεις για την κατανόηση της ΨΚΔ και την ανάγκη περαιτέρω έρευνας για τη βελτίωση της αξιοπιστίας των ερωτηματολογίων, την εξέταση διαφορετικών γνωστικών παραγόντων και την κατανόηση της αιτιολογίας της ΨΚΔ. Η μελέτη αναμένεται να προσφέρει σημαντική συμβολή στην κατανόηση της ΨΚΔ και στην ανάπτυξη αποτελεσματικότερων θεραπευτικών προσεγγίσεων.
Community-level dietary intake of sodium, potassium, and sodium-to-potassium ratio as a global public health problem: a systematic review and meta-analysis
Authors: Farapti Farapti , Maulia Putri Hersya , Fadilla Chusnul , Yogiswara Niwanda , Rejeki Purwo Sri , Miftahussurur Muhammad , Majid Hazreen Abdul
Published: September 2024

Background: Widespread adoption of a westernized diet represents a major lifestyle change characterized by substantially higher sodium consumption and lower potassium intake, which is related to cardiovascular morbidity. Methods: We performed a systematic review and meta-analysis over published studies in accordance with quantifying the dietary intake of sodium and potassium of the universal population across the world. The PubMed, EMBASE, Cochrane Library, and Google Scholar databases were used to find research that pronounced 24-hour urinary sodium or potassium excretion (reference period: 2014–2021). The effect size was estimated using the fixed-effect model; sub-group analysis become accomplished to determine urinary sodium and potassium excretion disaggregated by geographical location. Publication bias became evaluated the usage of graphical funnel plot. Data analysis was performed using STATA 16. Results: Forty-three studies (n= 62,940) qualified the selection criteria. The mean urinary excretion of sodium and potassium was 156.73 mmol/24h [95% confidence interval (CI), 148.98–164.47] and 48.89 mmol/24 h (95% CI, 43.61–54.17), respectively; the mean urinary sodium/potassium ratio was 3.68 (95% CI, 2.96–4.40). Conclusions: This updated systematic review highlights excessively high dietary intake of sodium and low intake of potassium at the community level in most parts of the world. The urinary Na/K ratio exceeded the level recommended by the WHO guidelines.
Recognizing human activities using light-weight and effective machine learning methodologies
Authors: Varadhi Keerthi , Someswara Rao Chinta , Sirisha GNVG , katari Butchi Raju
Published: September 2024

Background Human activity recognition poses a complex challenge in predicting individuals’ movements from raw sensor data using machine learning models. This paper explores the application of six prominent machine learning techniques – decision tree, random forest, linear regression, Naïve Bayes, k-nearest neighbor, and neural networks – to enhance the accuracy of human activity detection for e-health systems. Despite previous research efforts employing data mining and machine learning, there remains room for improvement in performance. The study focuses on predicting activities such as walking, standing, laying, sitting, walking upstairs, and walking downstairs. Methods The research employs six machine learning algorithms to recognize human activities, including decision tree, random forest, linear regression, Naïve Bayes, k-nearest neighbor, and neural networks. Results Evaluation of the human activity recognition dataset reveals that the random forest classifier, CNN, GRN and neural network yield promising results, achieving high accuracy. However, Naïve Bayes falls short of satisfying outcomes. Conclusions The study successfully classifies activities like SITTING, STANDING, LAYING, WALKING, WALKING_DOWNSTAIRS, and WALKING_UPSTAIRS with a remarkable accuracy of 98%. The contribution lies in the thorough exploration of machine learning techniques, with neural networks emerging as the most effective in enhancing human activity recognition. The findings showcase the potential for advanced applications in e-health systems and beyond.
Case Report: Pathological fracture in a Li-Fraumeni osteosarcoma patient: "Capasquelet'' femoral reconstruction and tumor vascular analysis with endomucin immunofluorescence multiplexing
Authors: Tran Guillaume , Amiaud Jerome , Combal Alexis , Duteille Franck , Redini Françoise , Verrecchia Franck , Crenn Vincent
Published: September 2024

We describe the case report of an Osteosarcoma patient, with a Li-Fraumeni Syndrome, presenting with a pathological femoral fracture. The patient was treated with a multidisciplinary approach associating neoadjuvant and adjuvant chemotherapy with excisional surgery. The femoral reconstruction consisted of a ``Capasquelet'' reconstruction combining an induced membrane and a vascularized fibula allograft allowing a good functional result with an early weight-bearing. We managed to complete our histological analysis in this patient, in order to evaluate the tumor vascularization. Indeed, using the syngeneic osteosarcoma MOS-J mouse model, we highlighted previously that CD31+/\ensuremath{\alpha}-SMA+ vessels may be indicators of vasculature normalization and therefore may be used as specific markers of a good therapeutic response. Thus, we search for its interest in this specific case as preliminary work. The aim was to assess the feasibility and technical validity of the vascularization analysis of a human osteosarcoma tumor specimen. Therefore, we propose an immunohistochemistry methodology  with multiplexed immunofluorescence to assess the vascularization as a promising marker in human osteosarcoma tissue.
Update on sexually transmitted infections in Korea: a narrative
review
Authors: Kim Chung-Jong
Published: September 2024

Sexually transmitted infections (STIs) continue to pose significant public health
challenges in Korea, with syphilis, gonorrhea, chlamydia, Mycoplasma
genitalium, and herpes simplex virus (HSV) being the most
prevalent. This review provides an updated overview of the epidemiology,
diagnosis, and treatment of these significant STIs in Korea, highlighting recent
trends and concerns. Syphilis incidence rates have fluctuated due to changes in
surveillance systems. Starting in 2024, syphilis will be reclassified as a
nationally notifiable infectious disease (category 2). Gonorrhea remains a
concern due to increasing antibiotic resistance, including the emergence of
extensively drug-resistant Neisseria gonorrhoeae strains,
underscoring the need for vigilant antimicrobial stewardship. Chlamydia
continues to be the most commonly reported STI, although its incidence has
declined during the COVID-19 pandemic. M. genitalium has gained
attention as a significant STI with rising antibiotic resistance issues,
necessitating updated treatment guidelines and consideration of resistance
testing. HSV-2 remains a common cause of genital herpes, with steady incidence
rates reported. Updated diagnostic methods, including nucleic acid amplification
tests, and revised treatment guidelines are presented to effectively address
these infections. The impact of the COVID-19 pandemic on other STIs within Korea
remains unclear, necessitating further research. Changes in treatment
guidelines, such as the recommendation of doxycycline as first-line therapy for
chlamydia, reflect evolving evidence and resistance patterns. The importance of
updated diagnostic tools, including resistance testing for M.
genitalium, is emphasized to improve treatment outcomes. Continued
efforts in education, prevention, and research are essential to manage and
mitigate the impact of STIs on public health in Korea.
Review article: Comparison of cosmetic regulatory policies in various countries toward consumer protection
Authors: Putri Kintan Amelia Asmoro , Segita Nur Elisa , Nuryadin Raissa Nuraini , Saputra Rio Dimas , Nur Yasmin Lutfiah , Silvia Deli
Published: September 2024

Cosmetics are various products that enhance physical appearance and care for the skin, hair, and body. Cosmetic regulation refers to the rules and regulations imposed by a country's government or health regulatory agencies to regulate the production, marketing, and use of cosmetic products. The purpose of writing this journal is to compare the regulation of cosmetic products in Indonesia with the regulation of cosmetic products abroad, and it is hoped that people will be more aware and understand the regulation of cosmetic products that have been established. The literature method is used to conduct a review article, and the criteria chosen are based on the originality and relevance of the reading.   The result of this writing is that the requirements regarding labeling in various countries are similar, such as composition, country of manufacture, product name, instructions for use, full name and address of the owner of the notification number (manufacturer), manufacturing batch number, expiration date, and special precautions that must be considered when using. Consumers must consider different regulations for cosmetic products in each country. These must be considered when making or selling cosmetic products: import and export regulations, limited ingredients, and safety testing of cosmetic products.
 
Keywords: Cosmetics, Export, Import, Labelling, Regulation
The importance of drug symbols and halal logos in the pharmaceutical industry: Effect, understanding, and implementation
Authors: Ramadan Hendra , Harbit Auratul Atifah , Azizah Siti Nur
Published: September 2024

With its predominantly Muslim population, Indonesia has significant potential in pharmaceuticals and herbal products, making it a focal point for government initiatives to drive growth in the sector. Despite these efforts, compliance with halal standards and obtaining halal certificates still face many challenges. This research examines the efforts to fulfill halal certification obligations by implementing halal standards in pharmaceutical and herbal products. This research uses a descriptive qualitative study; the data was collected through observational reviews and interviews and supplemented with a comprehensive literature study, which includes various sources such as journals, books, online media, and other additional references. This study reveals that setting standards or halal certification involves three parties, namely the Halal Product Assurance Organizing Agency (BPJPH), the Halal Examining Agency (LPH), and the Indonesian Council of Ulama (MUI). BPJPH implements the halal product guarantee. Then BPJPH will submit it to Lembaga Pengkajian Pangan, Obat-obatan dan Kosmetika (LPPOM) as LPH to check the adequacy of documents, compile audits, conduct audits, hold auditor meetings, issue audit memoranda, and submit audit result records to the MUI Halal Fatwa Session. Together with the Fatwa Committee, MUI determines the level of halalness of the product based on the audit results and issues a MUI Halal Decree.
 
Keywords: Herbs, Halal Industry, Halal Certificate, Medicines
Environmental Implications of Fly Ash Management and Utilization: A Review of Laws, Policies, and Practices.
Authors: Nomani M.Z.M. , Shaquib Omair , Lone Ajaz Afzal
Published: September 2024

In the environmental realm, ‘fly-ash’ refers to the byproduct of burning pulverized coal in thermal power stations. One of India's most resource-intensive and polluting industries, coal-fired power generation, contributes considerably to atmospheric pollution. Public power stations that use coal or lignite to generate energy account for 77% of the nation's total electricity production. This sector is responsible for over 65% of India's total coal use. This study employs a multifaceted approach combining theological, exploratory, analytical, and descriptive methods. It relies on secondary sources from diverse web resources to analyze fly ash's ecological and health impacts, explore utilization methods, and discuss potential legislation to prevent careless disposal. The coal-based power industry has added 32 GW, or over 64% of the new massive capacity, to its operations in the last decade, leading to a rise in coal consumption. There was a greater than 71% increase in annual coal usage, from 367 million tonnes in 2009–10 to almost 629 million tonnes in 2018–19. The increasing usage of coal in India has led to fly ash being one of the country's most significant industrial solid wastes. Fly ash is a residue or byproduct made when coal is burned; it is harmful to both humans and the environment. The problem is particularly acute in India because of the poor calorific value, high ash content, and low grade of the coal used there.
Characterization of Ash from Tropical Biomass Gasification for Soil Fertilization
Authors: Adamon David Gildas Farid , Chidikofan Djonoumawou Mèmèvêgni Grâce Floriane , Kinzo Charbel , Aviansou Gloire
Published: September 2024

This study aims to determine the characteristics of bottom ash from the gasification of four agricultural biomasses namely corn stalks and cobs, cotton stalks, and wood residues, for potential use as agricultural fertilizer. The methodological approach consisted in carrying out gasification trials for each of these biomasses under identical operating conditions on a pilot-scale gasifier. The fly ash was collected at the end of the tests from the reactor bottom and cyclone bottom for analysis. Analysis showed that the ash from the reactor bottom contained higher levels of mineral elements, including Ca, P, K, and Mg in comparison to the cyclone bottom ash. However, the latter exhibited a higher content of Zn. Trace metallic elements (TMEs) were present in relatively low proportions. Ash from the gasification of cotton stalks had the highest Ca, Mg, K, and P content. The TME content was relatively above the required threshold, but it remained below the threshold in the ash from corn stalks. This suggests that cotton stalk ash is more suitable for use in agriculture as a soil fertilizer.
Assessment of landslide susceptibility in the Himalayan state of Tripura, India, using a Multi-Model Approach
Authors: Das Debasis , Krishnaiah Y. V. , Panja Kausik , Mallick Manika , Hati Moumita , Rai Deepa , Chakma Atoshi
Published: September 2024

Landslides are the down slope mass movement of soil, rocks, and debris due to a natural or human activities resulting in widespread hazard events in India. The most affected areas comprise 15 percent of its landmass which includes Tripura and eleven Himalayan states and parts of the Western and Eastern Ghats in India. In Tripura, landslides cause road blockage and destruction of settlements, bringing economic and life losses in every year. Thus, this research is focused on identifying landslide susceptible zones and the significant causative factors behind landslides. Assessment of Landslide Susceptibility (LS) identifies fifteen major causative factors under five broad groups; topographic, geotechnical, hydrological, environmental, and anthropogenic. With application of Analytical Hierarchical Process (AHP), Frequency Ratio (FR), and Random Forest (RF)-based models were performed to extract landslide susceptible zonation map for Tripura. This study reveals that the successive hill ranges formed by young sedimentary lithologic formations associated with deforestation, heavy rainfall during monsoon, and anthropogenic activities (road constructions and jhumming) are the responsible geo-conditions for triggering landslides. In this study, while the AHP and FR model show only 1.95% and 11.46% confined along the hilltop of Jampui, Sakhan, and Longtarai, the RF model designated Tripura’s 30% land area as high and very high landslide susceptible zones (LSZ), predominantly over hills, foothills, and low laying undulating land (tillas). For the accuracy assessment, the ROC curve is used, which shows that RF model appears to be the maximum accurate (0.810) one, followed by FR (0.806) and AHP (0.744).
Comparative Study of the Coastal Geomorphology of Kajirbhati Sand-Spit Using Google Earth Pro Images (2005, 2011, 2023) and Landsat Satellite Data (2009, 2016, 2023): An Approach Towards the Impact of the Casuarina Plantation
Authors: Mane Madhuri M. , Sapkale Shivam J. , Susware Nilesh K. , Sapkale Jagdish B.
Published: September 2024

Coastal geomorphology undergoes constant transformation due to a combination of coastal and fluvial processes and human intervention. Remote sensing and GIS tools are invaluable in identifying and studying these changes. Due to the dynamic interaction between land and sea, the coastline requires careful monitoring to detect hotspots and understand the spatial and temporal impacts of climate change on the coastal environment. Remote sensing data offers a comprehensive means of studying coastal landform changes. In a recent study, the focus was to analyze the impact of the Casuarina plantation on the coastal geomorphology of Kajirbhati spit. This involved studying various depositional features such as sand bars, sand spits, dunes, and beaches. The study utilized Google Earth Pro images from 2005, 2011, and 2023 to digitize 13 classes each year, enabling the identification of changing geomorphic classes. These include agriculture, swash zones, dunes on sand spits, berm lines, Casuarina and coconut plantations, estuary, mangroves, mudflats, open land, sea, settlement, and vegetation. The results revealed dramatic changes in land use and land cover classes from 2005 to 2023. In the years from 2011 to 2023, the area of sandspit covered by Casuarina plants expanded rapidly. To analyze the changes, Landsat 5, 8, and 9 data were used to check the intensity of NDVI (Normalized Difference Vegetation Index) in 2009, 2016, and 2023. NDVI is a critical factor in this research. The mean NDVI values for 2009, 2016, and 2023 were -0.002, 0.02, and 0.04 respectively. The changes in higher NDVI values from 2009 to 2023 were -0.10, 0.27, and 0.28, while the lower values were -0.10, -0.10, and -0.07 for the same years. The correlation calculation between the mean NDVI values and the years indicates a strong positive correlation with an R-value of 0.99. Casuarina plants play a crucial role in protecting the coast from strong winds and dynamic sea waves. They help protect mudflats, mangroves, settlements, and estuary land use and cover classes along the coast of Kajirbhati.
Exploring Innovative Approach of Arbitration for the Resolution of Environmental Conflicts
Authors: Anand Ankit , J Vincent Comraj
Published: September 2024

The absence of a dedicated institution for conflict management and ambiguous dispute resolution mechanisms have been a major obstacle for the international and Indian environmental law regime. Environmental laws have undergone significant changes to address critical hazards; however, they frequently encounter difficulties in resolving disputes promptly. Arbitration has emerged as an indispensable instrument, particularly by the Permanent Court of Arbitration Optional Rules for the Arbitration of Environmental Disputes, 2001 (PCAORAED, 2001). These rules are imperative for providing customised solutions and accommodating various stakeholders, such as states, Non-Government Organisations (NGOs), multinational corporations, and individuals, thereby establishing arbitration as an inclusive and accessible alternative. The article emphasises how arbitration, when backed by specialised experts and a dedication to practical solutions, has the potential to emerge as the principal forum for resolving environmental disputes. Additionally, it investigates the potential for arbitration, traditionally associated with commercial disputes, to be creatively adapted to address the intricacies of environmental conflicts. The study comprehensively examines the arbitration processes employed by the PCA and other international instruments, underscoring the necessity of new approaches to address contemporary environmental challenges.
Organização do trabalho multiprofissional no atendimento à vítima de politrauma: diagnóstico situacional
Authors: Zuanazzi Eloisa Cesa , Forte Elaine Cristina Novatzki , Lazzari Daniele Delacanal , Silva Milene da , Boell Julia Estela Willrich
Published: September 2024

Objetivo: analisar a organização do trabalho multiprofissional no atendimento à vítima de politrauma. Método: estudo qualitativo, exploratório e descritivo realizado na emergência de um hospital referência em politrauma na região sul do Brasil, com 30 profissionais enfermeiros, técnicos de enfermagem e médicos, por meio de entrevistas estruturadas e observação não participante, em maio de 2023. Realizou-se análise interpretativa com agrupamento e organização dos dados em um mapa de associação de ideias. Resultados: emergiram três eixos: Estrutura - estrutura física inadequada, regulação ineficaz e força de trabalho; Processo – capacitação e comunicação e; Resultado: ausência de avaliação e liderança no atendimento. Considerações finais: foi possível evidenciar dificuldades na estrutura física, insuficiência de profissionais, problemas de comunicação e ausência de educação permanente. Ainda, o estudo revelou iniciativas individuais para superar limitações e colaboração mútua para enfrentar momentos críticos. Destaca-se a organização da equipe multiprofissional como um papel fundamental no atendimento à vítima de politrauma.
Spirituality and ageing: how to support older people in nursing or residential care homes
Authors: Barber Chris
Published: September 2024

In this article, Chris Barber discusses how care home staff can help residents to keep practicing their faith or spiritual beliefs.
Circular plastic consumption in everyday life: a nexus of practice perspective
Authors: Ȧberg Danai Myriam , Greene Mary
Published: September 2024

Plastic consumption is posing a critical challenge to global sustainability. Yet our understanding of the social and everyday dynamics of how and why people use plastics remains limited. Particularly, significant gaps in understanding exist concerning how plastics are embedded in households’ daily routines and practices and how this varies across different daily life settings. This article aims to bridge this gap by offering an in-depth exploration of the social and material dimensions of plastic consumption in varied Dutch households. Employing a theoretically and methodologically innovative approach, the article advances understanding of the connectivity of daily practices influencing household plastic use. Combining a social practice theoretical framework with a future-oriented, multi-modal imaginary methodology, we explore practice dynamics across diverse households of distinct life stages and compositions. Our analysis uncovers the complex interplay between daily practice arrangements and their systemic integration, revealing how daily life’s material, spatial and temporal dimensions are shaped and enabled by plastics. The study highlights the nuanced ways in which social variations in the organisation and institutional structures of daily life and engagement with socio-technical systems lock people into plastic consumption or enable transformative possibilities for sustainable change. By shedding light on the often overlooked social and everyday dynamics of plastic consumption, the article deepens theoretical understanding of practice connectivity while also opening new avenues for envisioning and facilitating transformation towards circular plastic consumption.
Development of an ultrafast laser system based on a Yb-doped fiber and a Yb:YAG thin-rod for the preclinical study of pigmented lesions treatment using a Hartley guinea pig
Authors: Kim Jun Wan , Kim Guang-Hoon , Park Seolwon , Park Byung Cheol , Kim Soon Re , Kim Juhee , Yang Juhee
Published: September 2024

In this research, we developed an ultrafast laser system based on a Yb-doped fiber oscillator and Yb:YAG thin-rod amplifier to investigate the efficacy of the laser for the treatment of pigmented lesions. The developed laser exhibited an output power of 22.7 W, center wavelength of 1030 nm, repetition rate of 495 kHz, pulse energy of 45.9 µJ, and pulse duration of 1.56 ps, respectively. For a compact and stable chirped pulse amplification system, a chirped fiber Bragg grating (CFBG) stretcher and a chirped volume Bragg grating (CVBG) compressor, both with fixed dispersion, were used. The dispersion of the total laser systems was precisely compensated by adjusting the length of the passive fiber and utilizing the self-phase modulation effect of the fiber amplifier. The developed ultrafast laser system was then applied in preclinical studies for the treatment of pigmented lesions in a guinea pig model. Three colored squares, each measuring approximately 15 × 15 mm, were treated by scanning a focused beam with varying laser fluences ranging from 0.5 to 2 J/cm2, using wavelengths of 515 nm and 1030 nm. The colorimeter measurements, which were performed 1-5 weeks after laser treatment, indicated that the laser was effective in reducing pigment, particularly black and blue pigments at higher fluences. This research represents the first trial of a preclinical study on pigmented lesions using an ultrafast laser system with a pulse duration below 10 ps, shorter than the stress relaxation time of 10 nm melanin granules. The results are meaningful as they offer valuable insights into the effectiveness of ultrafast laser therapy.
Homogeneous large field-of-view and compact iSCAT-TIRF setup for dynamic single molecule measurements
Authors: De Angelis Giovanni , Abramo Jacopo , Miasnikova Mariia , Taubert Marcel , Eggeling Christian , Reina Francesco
Published: September 2024

Interferometric scattering microscopy (iSCAT) enables prolonged and high frame rate single particle tracking (SPT) for studying molecular dynamics. Typical iSCAT setups employ conventional widefield or scanning illumination schemes. However, these implementations limit the field-of-view (FoV), the uniformity of the illumination and thus comparable accuracy over the whole FoV, and/or the maximum sampling rate, while in parts increasing hardware requirements and setup size. We demonstrate the realization of a large (60 µm x 60 µm) uniformly illuminated FoV through a passive refractive optical element in the iSCAT illumination path. This scanning-free iSCAT microscope setup is further combined with an objective based total internal reflection fluorescence microscopy (TIRF) channel for a complementary fluorescence readout, a focus-lock system, and a tailored control platform via the open-source ImSwitch software, and it has a compact footprint. As a proof-of-principle, we highlight the performance of the setup through the acquisition of iSCAT images with a uniform contrast and a constant ≤10 nm localization precision throughout the whole FoV. The performance is further demonstrated through dynamic iSCAT SPT and imaging fluorescence correlation spectroscopy (imaging FCS) of lipid diffusion in a model membrane system, highlighting the ability to track a large number of molecules with the same accuracy over a large FoV. Our iSCAT setup thus depicts an accurate and improved way of recording fast molecular dynamics in life sciences.
Generation and control of circular Airy solitons in fractional nonlinear optical systems under different modes
Authors: Tan Chao , Lei Tong , Zou Min , Liang Yong , Liu Mingwei
Published: September 2024

In this paper, the dynamics of the circular Airy beam (CAB) in the spatial fractional nonlinear Schrödinger equation (FNLSE) optical system are investigated. The propagation characteristics of CABs modulated by the quadratic phase modulation (QPM) in a Kerr (cubic) nonlinear medium under power function diffractive modulation modes and parabolic potentials are numerically simulated by using a step-by-step Fourier method. Specifically, the threshold for CABs to form solitons in the Kerr medium is controlled by the Lévy index and the QPM coefficient. Secondly, the parabolic potential has the ability to stabilize the FNLSE optical system, making it easier for the formation of CAB solitons. The addition of QPM allows the refocusing of the split beam caused by the Lévy index, and it can change the position and intensity of solitons. Finally, we also study the transmission evolution of QPM-modulated CABs in the Kerr medium under the power function diffraction modulation mode. We can obtain different types of solitons by varying the power function modulation coefficients. A dark soliton with high stability is formed, and we can control its size. Results show that it is possible to optimize the parameter settings (parabolic potential coefficients, power function modulation coefficients, QPM coefficients, Lévy indices, and nonlinear Kerr intensity coefficients) to obtain different types of solitons as well as to modulate the soliton transport. It provides more degrees of freedom for the study of CAB soliton propagation in the Kerr media, which is of great significance and application in fields of nonlinear optical transport, particle manipulation, and optical metrology.
Rotating manipulation of femtosecond optical tweezers based on optical wedge-lens group
Authors: Zhang Xia , Wu Yi , Zhu Xiaoli , Feng Guoying
Published: September 2024

Currently, research on optical tweezers technology predominantly focuses on single-trap optical tweezers, which have a limited controllable range. Multi-trap optical tweezers effectively address these limitations. This paper proposes a method for developing a dual-trap optical tweezers system utilizing basic optical elements. Two optical traps are created by reflecting a laser beam off the front and rear surfaces of a beam splitter. The transition between single-trap and dual-trap configurations is facilitated by a lens group, which allows for the adjustment of the distance between the two traps. Furthermore, by incorporating a rotatable optical wedge into the optical path, the optical trap can be rotated along an annular orbit of any radius. This study includes simulations and analyses of the effects of lens spacing, refractive index, and tilt angle on the rotational range of optical traps. An optical trapping experimental system was constructed, and its feasibility was demonstrated using polystyrene particles as the target objects.
Second harmonic generation and third harmonic enhancement in silicon by a composite metasurface and intense terahertz
Authors: Zhong Hui , Song Liwei , Tian Ye
Published: September 2024

The compression and integration of nonlinear optical processes to the nanoscale are expected to have significant implications for quantum optics, biology, and medicine. In this work, a composite metasurface consisting of a hollow-bow-tie-shaped metal metasurface and a patterned amorphous silicon metasurface is proposed. An external terahertz (THz) electric field enhanced by the hollow-bow-tie structure is employed to break the centrosymmetry, which allows the generation of optical second harmonic. Meanwhile, the amorphous silicon nanocolumns inside the hollow-bow-tie-shaped structure enhance the optical laser field and improve the conversion efficiency of second and third harmonics. The numerical results indicate that at an incident optical laser intensity of 1.20 GW/cm2 and a y-component of the incident THz electric field of 10 kV/cm, the powers of the generated second and third harmonics are 3.96 × 10−6 W and 7.42 × 10−6 W, respectively, with conversion efficiencies of 3.93 × 10−7 and 7.18 × 10−7. The conversion efficiency of the third harmonic is increased by a factor of 700 compared to that of unpatterned silicon. The configuration proposed in this paper offers a solution for applications that need to take into account both high nonlinear efficiency and ultra-fast tunability.
Picometer-scale OAM interferometry using an adaptive polar transform algorithm
Authors: Ni Lanlin , Xia Haojie , Xu FeiFan , Wu Qiang , Zhang Jin , Chang Songtao
Published: September 2024

A phase demodulation algorithm based on an adaptive polar transform is proposed that can achieve picometer-scale measurements in orbital angular momentum (OAM) interferometry. The proposed algorithm converts the rotational movement in a petal-shaped interference pattern into translational movement of the grayscale projection curves, so that can be easily measured using correlation operations to determine the pixel displacement in determining the rotation angle. Displacements ranging from -120 nm to 120 nm have been measured for various topological charges, with a minimum average deviation of 0.07 nm. Furthermore, we have studied the effects of piezoelectric transducer alignment, various binary threshold values, fringe occlusion, and charge-coupled device (CCD) camera resolutions on displacement measurement. Comparative experiments indicate that the proposed algorithm can effectively manage the local measurement challenges in traditional OAM interferometers, demonstrating better measurement accuracy and robustness than several existing phase demodulation algorithms.
Crossed-cell-tile multiplexed 1st-order gratings, for three-dimensional beam-splitter applications
Authors: Subash Uma , Poutous Menelaos K.
Published: September 2024

Oblique angle of incidence two-way and three-way beam splitters were designed and fabricated. The devices feature two first-order diffraction gratings, arrayed crossed in alternating adjacent tiles, resulting in conical diffraction spot separation of two 1
st
-orders in orthogonal planes while overlapping the 0
th
-order. The two-way beam splitter was designed for 0
th
−order suppression. The three-way beam splitter was designed to distribute light equally between the 1
st
and 0
th
 − order spots. Testing of the devices yielded efficiencies of 2%:46%:46% for the two-way beam splitter at 604 nm, and 32%:32%:32% for the three-way beam splitter at 633 nm wavelength. The polarization state of the incident beam was preserved after diffraction through the devices.
Extended Monte Carlo modeling for submicron particle size measurement under high light extinction conditions
Authors: Su Geyi , Zhang Shiwei , Guan Minglei , Su Mingxu
Published: September 2024

The light extinction method (LEM) based on Lambert Beer's law (LB) is widely used to characterize particle size distribution (PSD) in multiphase flow. However, as the optical thickness increases with concentration, the phenomenon of multiple scattering is enhanced, potentially leading to reduced accuracy and a limited application range. In this study, an extended Monte Carlo-based light extinction model (EMC) was developed, which was initially employed to calculate and evaluate the impact of multiple scattering. Subsequently, it was used to predict the extinction spectrum that incorporates multiple scattering effects under varying concentrations. To validate the modeling, a compact setup was constructed to perform a series of experiments on polystyrene and silica dioxide (SiO2) suspensions. A differential evolution algorithm was also implemented for the inversion of PSD based on spectral content, with the incorporation of an improved coefficient matrix that considers multiple scattering effects. In comparison to the linear LB model, the EMC exhibits a markedly enhanced capacity in handling higher particle concentrations and improving measurement accuracy. For a 700 nm PS suspension, the particle size inversion error of the EMC can be kept within 4% (93.86% for the LB model) compared with the nominal value, even with an optical thickness of 5.
Broadband all-dielectric meta-lenses with terahertz full-Stokes polarization detection behavior
Authors: Li Hui , Zhao Chenhui , Li Jie , Zheng Chenglong , Xu Hang , Xu Wenhui , Tan Qi , Song Chunyu , Shen Yun , Yao Jianquan
Published: September 2024

Polarization is a fundamental characteristic of electromagnetic (EM) waves, and accurately determining the polarization state is crucial for spectral imaging and information processing. However, implementing broadband polarization detection in the terahertz (THz) range poses significant challenges when employing conventional optics. This paper proposes and experimentally evaluates a broadband polarization detection strategy using all-dielectric metasurfaces. By employing the technique of circular polarization multiplexing, the proposed approach allows for the generation of a focus that contains the incident polarization information at a predetermined plane. When a fully polarized THz beam interacts with the proposed design, its two orthogonal circularly polarized components weighted equally and simultaneously converge at designed spatial coordinates. Subsequently, by capturing the complex amplitude at the target pixel, the full-Stokes parameters and equations of the polarization ellipse corresponding to the incident polarization state can be extracted in real time. Further optimization of the phase encoding profile embedded within the orthogonal circular polarization channel can eliminate the chromatic aberrations within the target bandwidth, thereby achieving broadband THz polarization detection. This method facilitates the determination of polarization states across the broadband THz spectrum and holds significant promise for advancing polarization-related research in areas such as detection, communication, and sensing.
Wide-range and ultra-low temperature thermometer based on a silicon resonator
Authors: Zhu Xiantao , Lin Zude , Li Xiuyan , Yang Bin , Liu Jingquan , You Minmin
Published: September 2024

In this Letter, the silicon-based microring resonator (MRR) was experimentally demonstrated for cryogenic sensing down to 10 K by overcoming the issue of acquiring the optical signals at low temperatures for on-chip optical sensors. A wide-range temperature sensor from 240 to 10 K was obtained. The experimental results show that the device sensitivity decreased from 64.7 pm/K at 240 K to 4.19 pm/K at 10 K. Theoretical analysis indicates that the reduction in sensitivity is attributed to the weakening of thermo-optic effects with the decrease in temperature, which is well consistent with the experimental results. Based on this work, the silicon-based ring resonators, featuring complementary metal oxide semiconductor (CMOS) compatibility, high-quality factors, and ease of chip-scale integration, are a potential platform for ultra-low temperature monitoring.
Fourier phase retrieval using physics-enhanced deep learning
Authors: Zhang Zike , Wang Fei , Min Qixuan , Jin Ying , Situ Guohai
Published: September 2024

Fourier phase retrieval (FPR) aims to reconstruct an object image from the magnitude of its Fourier transform. Despite its widespread utility in various fields of engineering and science, the inherent ill-posed nature of the FPR problem poses a significant challenge. Here we propose a learning-based approach that incorporates the physical model of the FPR imaging system with a deep neural network. Our method includes two steps: First, we leverage the image formation model of the FPR to guide the generation of data for network training in a self-supervised manner. Second, we exploit the physical model to fine-tune the pre-trained model to impose the physics-consistency constraint on the network prediction. This allows us to integrate both implicit prior from training data and explicit prior from the physics of the imaging system to address the FPR problem. Simulation and experiments demonstrate that the proposed method is accurate and stable, showcasing its potential for wide application in fields utilizing the FPR. We have made our source code available for non-commercial use.
Ultrasensitive optical electric field sensor with temperature compensation for point-wise and quasi-distributed sensing
Authors: Wang Yongguang , Wang Guochen , Xia Xiuwei , Gao Wei , Wang Zicheng , Zhao Yuxin
Published: September 2024

A point-wise and quasi-distributed optical sensing technique with the Vernier effect is proposed and achieved by multiplexing Fabry–Perot interferometers (FPIs). The FPIs are fabricated by LiNbO3 (LN) crystals of varying lengths to enable simultaneous measurement of electric field (E-field) and temperature. Compared to the traditional bulk-type optical E-field sensors, this innovative sensor enables E-field measurement without being limited by half-wave voltage and effectively avoids the influence of natural birefringence. By an algorithm based on the Fourier transform, sub-FPIs are addressable, and their interference spectra can be demodulated independently, where any two FPIs are paired to generate the fundamental Vernier effect (FVE) or harmonic Vernier effect (HVE). Thus, the measurement sensitivities of FPIs can be significantly improved by monitoring the spectral shift of the envelope in the superimposed spectra. The quasi-distributed sensing experiment is conducted using three cascaded FPIs, yielding E-field sensitivities of 2.84 nm/E (FVE) and 3.37 nm/E (HVE), with a standard deviation (STD) of spectrum variation after temperature compensation below 3.19 × 10−3. The proposed multiplexing method is significant for practical applications of the E-field quasi-distributed measurement.
Phase-locked high-brightness interband cascade laser array with multimode interferometer couplers
Authors: Song Zheyu , Sun Ruixuan , He Feiyang , Liu Shuman , Ye Xiaoling , Zhang Jinchuan , Liu Junqi , Wang Lijun , Zhuo Ning , Zhai Shenqiang , Cheng Fengmin , Liu Fengqi
Published: September 2024

We report on the design, fabrication, and characterization of an interband cascade laser (ICL) array incorporating multimode interference (MMI) couplers for phase-locking emitters. The ICL array, emitting at 3–4 µm, was developed to address the challenges of heat dissipation and in-phase operation in mid-infrared lasers. The array features a 7.5-µm-wide ridge design for fundamental transverse mode propagation and employs MMI structures to realize an in-phase operation of multiple emitters. The far-field patterns, characterized by periodic and symmetrical interference fringes, confirm the coherent operation of the array and the efficacy of MMI couplers in achieving phase-locking. The single-ridge side of the array exhibits a single-lobe far-field profile, with higher-order transverse modes effectively suppressed, showcasing a nearly diffraction-limited beam quality (M2 ≈ 1.31) at high output powers (390 mW from the 1 × 4 array). The robust performance and scalable design of the ICL array, validated by experimental results and theoretical simulations, indicate its potential for high-power mid-infrared applications and as an optical phased array.
Minimize flow-induced uncertainty in polarization sensitive optical coherence tomography imaging using eigen decomposition
Authors: Shi Yaping , Liu Jian , Gong Zhaoyu , Wang Ruikang K.
Published: September 2024

Blood flow alters the scattering behavior of penetration light, causing instability in the polarization state to emerge at the underlying tissue during polarization-sensitive optical coherence tomography (PSOCT). We propose an eigen decomposition method to meet this challenge, where the static and dynamic scattering signals are separated for PSOCT to provide the polarization measurements of the tissue of interest that is located beneath the blood flow. Using flow phantoms made by Intralipid solution and 3D-printed birefringent material, we show the flow-induced effects on the measurements of sample birefringent properties of optical axis, phase retardation, and degree of polarization uniformity. We demonstrate the usefulness of the proposed method through in vivo imaging of the human nail fold.