Intensity Of Exposure Research Articles

The association between secondhand smoke exposure and risk of developing active tuberculosis in individuals with latent tuberculosis infection: a systematic literature review.

Tuberculosis is one of the leading causes of death from infectious diseases in the world, with approximately 25% of the global population having latent tuberculosis infection. Secondhand smoke exposure has been recognised as a significant risk factor in the development of active Tuberculosis in individuals with latent tuberculosis infection. This study used the Systematic Literature Review method based on PRISMA guidelines. Relevant articles published between 2014-2024 were identified through PubMed, ProQuest, and Scopus databases using related keywords. A total of 13 articles met the inclusion criteria for analysis. Secondhand smoke exposure significantly increases the risk of latent tuberculosis infection conversion to active Tuberculosis, with a stronger effect in vulnerable groups such as children and individuals who are in close contact with active Tuberculosis patient and live in the same household with heavy smokers. This risk of exposure to secondhand smoke follows a dose-response pattern, where longer duration and higher intensity of exposure directly increase the likelihood of Tuberculosis activation in individuals with latent tuberculosis infection. The biological mechanisms involve immune suppression and lung damage caused by toxic particles in the tobacco smoke, which weaken the body's defenses against Mycobacterium tuberculosis and facilitate the progression of latent tuberculosis infection to active Tuberculosis. Therefore, reducing exposure to secondhand smoke is important to mitigate its impact on active Tuberculosis progression. Secondhand smoke exposure has been consistently shown to increase the risk of developing active Tuberculosis in individuals with latent tuberculosis infection. To support the global Tuberculosis elimination programme, concerted efforts are needed to reduce exposure to secondhand smoke, especially in individuals with latent tuberculosis infection.

Pyridinium surfactants can modulate the UV response of methyl green dye‐doped polymeric films for sensor development

AbstractConcerns about ultraviolet radiation (UV‐R) are increasing due to climate change. The effects of UV‐R on living organisms depend on exposure duration and intensity, making it crucial to monitor UV‐R levels. In this study, we investigated the role of surfactants as photosensitizing or stabilizing agents in a colorimetric sensor based on a polymeric film doped with methyl green dye. The films were synthesized using the casting technique from a filmogenic solution containing either carboxylated polyvinyl alcohol (P1) or hydroxylated polyvinyl alcohol (P2). We evaluated the impact of surfactant structure (dodecylpyridinium chloride, C12; hexadecylpyridinium chloride, C16; or sodium dodecyl sulfate, SDS) and concentration on the colorimetric response of the films to UV‐R. Color changes were monitored using the CIELab system. The results showed that, under UV‐R exposure for up to 5 h, films without surfactants did not lose their blue hue (negative b* parameter in CIELab). While SDS stabilized the dye in the polymeric matrix, films containing pyridinium surfactants (C12 or C16) changed color from blue to pale yellow (positive b* parameter in CIELab). The color change, which was modulated by surfactant concentration, was attributed to radical reactions involving the pyridinium surfactants, influenced by their hydrophobicity and the polymer structure. These results represent a significant advancement in colorimetric sensors for UV‐R, as they allow for the modulation of the sensor's response time through surfactant concentration in the polymeric film.

Epidemiologic survey for work-related idiopathic interstitial pneumonias focusing on idiopathic pulmonary fibrosis in Korea, 2010-2022.

This study aimed to share the process of epidemiologic survey and demonstrate the decisive factors for evaluating work-related Idiopathic interstitial pneumonias (IIPs) in Korea. Data and reports of epidemiologic surveys were investigated and completed during 2010-2022. A total of 228 idiopathic pulmonary fibrosis (IPF) cases requested for an epidemiologic survey, of which 153 (67.1%) were work-related. The level of exposure intensity was more than intermediate and the exposure duration was more than 10 years in the work-related IPF, so the decisive factors for work-related IPF were exposure substances, intensity and duration.The main factors for work-related acute interstitial pneumonia or cryptogenic organising pneumonia were exposure latency and exposure intensity. The results of this study indicated the process of the epidemiologic survey and important factors for evaluating work-related IIPs.

Enhancing entangled two-photon absorption of Nile Red via temperature-controlled SPDC

Entangled two-photon absorption can enable linear scaling of fluorescence emission with the excitation power. In comparison with classical two-photon absorption with quadratic scaling, this can allow fluorescence imaging or photolithography with a high axial resolution at minimal exposure intensities. However, most experimental studies on two-photon absorption were not able to show an unambiguous proof of fluorescence emission driven by entangled photon pairs. Meanwhile, existing theoretical models struggle to accurately predict the entangled two-photon absorption behavior of chemically complex dyes. In this paper, we introduce an approach to simulate entangled two-photon absorption in common fluorescence dyes considering their chemical properties. Our theoretical model allows a deeper understanding of experimental results and thus the occurrence of entangled two-photon absorption. In particular, we found a remarkable dependency of the absorption probability on the phase-matching temperature of the nonlinear material. Furthermore, we compared the results of our theoretical approach to experimental data for Nile Red.

Impact of bedroom light exposure on glucose metabolic markers and the role of circadian-dependent meal timing: A population-based cross-sectional study.

Light at night (LAN) has become a global concern. However, little is known about the effects of bedroom LAN exposure on glucose metabolism markers. We aimed to explore the association between intensity and duration of bedroom LAN exposure with glucose metabolism markers, and the role of circadian-dependent meal timing in these associations. Real-ambient bedroom LAN exposure was measured using a portable illuminance meter for two consecutive days. Seven consecutive days of sleep time and 24-h dietary records were assessed by wrist-worn accelerometer and mobile phone photos, respectively. Circadian-dependent meal timing, including the timing of meal relative to clock time and sleep time, was calculated from 24-h dietary records and sleep data. The mean age of participants was 18.7 years, and 32.8 % were male. Per SD lx increase of bedroom LANavg was associated with 1.75 μU/mL-increase in INS (95 %CI: 0.10, 2.50), 0.61 unit-increase in HOMA-IR (95 %CI: 0.43, 0.79), and 0.09 unit-increase in TyG (95 %CI: 0.04, 0.15); per SD min increase of bedroom LAN3 was associated with 1.61 μU/mL-increase in INS (95 %CI: 0.84, 2.37), 0.48 unit-increase in HOMA-IR (95 %CI: 0.29, 0.67), and 0.07 unit-increase in TyG (95 %CI: 0.01, 0.13). Nevertheless, these associations were found to be significant in later circadian-dependent meal timing group while weaker or not significant in earlier circadian-dependent meal timing group (time of first meal ≤ 9:00, time of last meal ≤ 19:00, first meal - sleep end ≤ 2 h, and sleep onset - last meal ≥ 5 h). Overall, bedroom LAN exposure was associated with impaired glucose metabolism markers among young adults. Importantly, circadian-dependent meal timing may have potentially moderate effects on these associations. Keeping bedroom darkness at night and adhering to early eating pattern may be important public health strategies to reduce the risk of glucose metabolism disorders.

Reactive changes in dental tissues in response to curing light exposure: An experimental study

BACKGROUND: The use of curing lamps has considerably improved the quality of dental treatment. Curing light exposure protocols are primarily based on the effectiveness (completeness) of cure. The risk of heat impact on the dental pulp and surrounding tissues is a downside of curing light radiation. There is a need for experimental confirmation of differentiated selection of curing light exposure protocols (intensity and time of exposure) in terms of minimum impact on tissues. AIM: To assess the effect of curing light on dental tissues. MATERIALS AND METHODS: An experimental simulation of the use of curing light in dental practice during dental restoration was performed. The experiment was performed in 50 rats randomized into four groups: Group 1 (control, n=5) and Groups 2–4 (treatment, n=15 each). The control group was not exposed to curing light. In the treatment groups, mandibular incisors of the experimental animals were exposed to curing light in three modes. The animals were sacrificed by decapitation after 7 days in Group 1 and after 1, 3, and 7 days in Groups 2–4. A total of 100 teeth were extracted for pathomorphological examination. A total of 320 histological sections (enamel, dentin, and pulp slides) were prepared, stained, and examined. The descriptive method was used to assess the findings. RESULTS: Changes in the pulp showed pathomorphological signs of acute inflammation, most prominent on Day 3, which was considered a defense response of the pulp to irritation. The microvasculature showed the most significant changes, with increased, inhomogeneous blood filling, plasmorrhagia of capillary walls, and stasis in capillary lumen. There were no morphological changes in hard dental tissues. The initial response of the dental pulp to curing light exposure in experimental animals was uniform and unaffected by the technical specifications of curing lamps. On Day 7, there was no morphological response in the pulp when exposed to diode light at 1,000 and 1,400 mW/cm2. At this point, the microscopic appearance of the pulp exposed to diode curing light at 3,200 mW/cm2 was generally comparable to that at baseline, with residual perivascular cellular infiltration of the stroma and capillary congestion. CONCLUSION: The experimental findings indicate a risk of negative photochemical reactions in the pulp following curing light exposure during treatment of patients with hard dental tissue pathologies. The data on the effect of curing light on the dental pulp can be used in real-world dental practice when selecting a composite curing algorithm during dental restoration to reduce the risk of unexpected reactions to curing light.

A Pilot Dashboard System to Track Cumulative Exposure to Sound Levels during Music Instruction: A Technical Report.

Music-induced hearing loss (MIHL) is a critical public health issue. During music instruction, students and teachers are at risk of developing hearing loss due to exposure to loud and unsafe sound levels that can exceed 100 dBA. Prevention of MIHL in music students must be a desired action of all music educators. To promote deliberate changes in music instruction and encourage more moderate sound creation and exposure during music education, it is essential to equip the instructors with live dynamic tools to monitor the overall sound intensities during music instruction. Equally important data to convey to the instructors are information regarding the intensity and duration of sounds at specific frequency regions in the music they are generating. Unfortunately, there are no feasible techniques to track cumulative live music exposures at various frequencies nor are there any guidelines for safe music exposure. We created a visually appealing, user-friendly dashboard prototype system to display the accumulated time and intensity of sound exposure during live classes/rehearsals categorized into three frequency ranges. These visuals can be easily understood at a glance allowing musicians and instructors to make informed decisions about how to play music safely. The dashboard included a collection of circular dial graphs that displayed in real time the accumulated sound exposure in the instructor's selected frequency range and showed the percentage of the maximum daily sound exposure based on the National Institute for Occupational Safety and Health Standards (NIOSH, 1998). Although NIOSH standards are not widely applied for music exposure, we propose that these standards can be used to provide initial guidelines to develop critical levels of music exposure. Additionally, the dashboard included a color-coded equalizer that displayed the instantaneous frequency distribution of sounds to indicate if sound levels at specific frequencies were too high even for short-term exposure. Less expensive than existing technology and more convenient to use, this dashboard will enable music instructors to make informed decisions on how to best adapt their teaching approaches to protect the hearing health of their students.

Assessing antimicrobial use patterns in Christian Health Association of Malawi (CHAM) health facilities: A cross-sectional study protocol.

The threat of antimicrobial resistance (AMR) in Malawi is high with reported mortality of 19,300 annually, the 23rd highest age-standardised mortality. One of the drivers of AMR is misuse of antibiotics, a phenomenon that has not been adequately researched in Malawi. This study aims to investigate antimicrobial use using health facility, prescribing and patient indicators in Christian Health Association of Malawi (CHAM) health facilities. This will be a multiple cross-sectional study, which will collect data from facilities (22), prescriptions (660), and patients (303). Data will be collected using KoboToolbox v2021, and exported into Microsoft Excel version 2016 for cleaning and coding. Variables will be categorised according to the antimicrobial use indicators. The study will use STATA Version 14 statistical software for data analysis. Subsequently, facilities will be entered into ArcGIS Version 10.7.1 to map hotspots of irrational antimicrobial use. The study will run from October 2024 to June 2025. This study will provide detailed information on frequently used antimicrobials, the cost of antimicrobials relative to medicine budget, the intensity of exposure to antimicrobials, the availability of antimicrobials, patients' understanding of antimicrobials use, and availability of important documents for antimicrobial use. Secondarily, the study will unravel the prevalence of irrational antimicrobial use, the main factors contributing to it, and location where irrational use is most prevalent. These findings will inform the national antimicrobial stewardship action plan, aiming to safeguard the available antimicrobials.

Dental status as an indicator of the intensity of exposure to chemical pollution of the air in the working area

Introduction. Lack of knowledge of the oral status in chemical production workers determines the relevance of this study. In most studies, we did not find sufficiently comprehensive information about working conditions. Aims. To assess the risks of developing somatic and dental pathologies among chemical production operators depending on the intensity and duration of exposure to chemical factors in order to reduce the occupational cause of health deterioration. Materials and methods. A comprehensive clinical and hygienic examination was conducted in eight hundred seventy eight isoprene, divinyl, styrene, ethylene oxide production apparatchiks who were exposed to harmful substances. The working conditions are analyzed according to the production control data. The analysis of the microbial profile in periodontal pockets in 128 workers by polymerase chain reaction was performed. Results. In the studied industries, differences were noted in the levels of exposure of the chemical factor to the body: in the production of divinyl and isoprene, working conditions corresponded to hazard class 3.1, styrene to class 3.2, ethylene oxide to class 3.3. Styrene production workers had a high degree of industrial conditionality of chronic cholecystitis (RR=2.16; EF=53.6%), biliary dyskinesia paths (RR=2.53; EF=60.5%). Ethylene oxide production apparatchiks showed a high degree of industrial conditionality of subatrophic nasopharyngitis (RR=2.60; EF=61.6%), chronic catarrhal laryngitis (RR=2.83; EE=64.7%), and severe chronic periodontitis (RR=2.36; EF=57.7%). The high prevalence of periodontopathogens P. Gingivalis and A. Actinomycetemcomitans has been shown. Limitation. The lack of immunological and cytogenetic analysis data necessary for preclinical diagnosis of pathological changes in the oral cavity. Conclusion. Significant differences in the level of exposure of the chemical factor to the health in workers have been revealed. A high degree of industrial conditionality of a number of somatic diseases in workers of styrene and ethylene oxide industries has been determined. The greatest deviations in the state of oral health were observed in ethylene oxide production workers with more than 20 years of work experience. Differences in the species composition of the microbiome of periodontal pockets in ethylene oxide apparatchiks, depending on work experience, were detected.

Ways to improve the effectiveness of uvulopalatoplasty

Ronchopathy is a complex polyethological disease that has a multifactorial negative effect on the cardiovascular, respiratory and other systems of the body. Mortality in this terrible disease, most often from vascular causes and, especially, in the presence of obstructive sleep apnea syndrome, ranges from 6 to 11%, and the consequences of various complications associated with this disease increase it to 37%. The effectiveness of surgical methods of treating patients with ronchopathy is still clearly unsatisfactory, and does not allow most of them to achieve a guaranteed recovery. At the same time, the growing number of such patients, who are in dire need of effective treatment and reliable prevention of complications of this disease, encourages specialists to further search for surgical treatment methods. Surgical interventions on the soft palate in patients with ronchopathy and obstructive sleep apnea syndrome are based on the principle of injury to the palatine curtain of varying intensity (surgical, thermal, radiofrequency, laser, chemical), independent of the methods of exposure. At the same time, depending on the intensity of exposure, inflammation, necrosis or partial tissue rejection are noted and, as a result, scarring, compaction and a decrease in the volume of the palate. At the same time, the mobility of the palatine curtain should decrease, and the intensity of snoring should decrease. However, injury caused primarily to the velopharyngeal muscles often leads to hypo- and atrophy, hypotension and significant sagging of the palate, and, subsequently, to a recurrence of the disease and increased snoring. This significantly reduces the effectiveness of surgical treatment of these patients. Increasing the effectiveness of uvulopalatoplasty is one of the tasks of modern otorhinolaryngology. Ways to increase the effectiveness of uvulopalatoplasty lie in the following directions: qualitative and adequate selection for the upcoming operation; accurate determination of the level(s) of obstruction, shape and degree of collapse of the soft tissues of the upper respiratory tract; careful consideration of the structural features of the soft palate and pharynx of each individual patient; maximum reduction of surgical trauma to the tissues of the palatine curtain during surgery.

Potential for use of hypoxic preconditioning in aviation medicine

The paper evaluates Russian and foreign literature on the positive effects of dosed hypoxia on human body in the setting of training stimulation. This model can serve as a theoretical basis for the development of a hypoxic preconditioning technique, which can be extremely useful for air medical officers to maintain the professional health of pilots in modern conditions. The aim of this review was to inform a wide range of stakeholders about the various effects of hypoxic preconditioning, including cardioprotective, neuroprotective and vasoprotective effects. Existing hypoxic training techniques were reviewed, especially the advantages of normobaric hypoxic training to improve the functional status of pilots. The main advantages of this technique include possibility of wide use on flat terrain, the absence of changes in atmospheric pressure during training, no need for specially trained personnel and special premises, the possibility of selecting an individual training program, combination of hypoxic training with everyday tasks, minimal side effects, and long-term maintenance of training results. The mechanisms underlying hypoxic preconditioning are discussed, including the activation of genes encoding proteins involved in the regulation of oxygen homeostasis. The latest research data in hypoxic training are described. The paper also addresses issues that are not generally understood by practitioners who use hypoxia for therapeutic and preventive purposes (effectiveness of different techniques, role of blood saturation levels during hypoxic training, difference between preconditioning and postconditioning, and other aspects of practical hypoxic therapy). All these questions need to be answered in the near future in order to better understand the activation of human internal defense mechanisms by non-drug methods. Further studies are needed to determine the optimal preconditioning technique, including the duration and intensity of hypoxia exposure.

Preliminary Study on the Measurement of Cadmium Levels in Scavenger Hair at Sukawinatan Landfill Palembang

Cadmium (Cd) is a toxic heavy metal with the potential to contaminate the environment, particularly in landfill sites using open dumping systems, such as the Sukawinatan Landfill in Palembang. This study aims to measure Cd levels in scavengers’ hair as an indicator of heavy metal exposure. A cross-sectional study design was conducted in January 2024, with hair samples collected from five respondents using purposive sampling techniques. Cd levels were measured using the Atomic Absorption Spectrophotometry (AAS) method. The results showed that Cd levels in the scavengers' hair ranged from 0.31 to 0.99 ppm, exceeding the normal limit set which is <0.10 ppm. The duration of work as a scavenger was identified as the dominant factor influencing Cd levels, although anomalies were observed in younger scavengers with high exposure intensity. These findings suggest that the working environment at the landfill significantly contributes to the accumulation of Cd in the body. This study provides preliminary insights into the health risks faced by scavengers at the Sukawinatan Landfill, which can serve as a basis for developing policies and mitigation measures to improve scavengers' occupational health and safety.

Contributions of associative and non-associative learning to the dynamics of defensive ethograms

Defensive behavior changes based on threat intensity, proximity, and context of exposure, and learning about danger-predicting stimuli is critical for survival. However, most Pavlovian fear conditioning paradigms focus only on freezing behavior, obscuring the contributions of associative and non-associative mechanisms to dynamic defensive responses. To thoroughly investigate defensive ethograms, we subjected male and female adult C57BL/6 J mice to a Pavlovian conditioning paradigm that paired footshock with a serial compound stimulus (SCS) consisting of distinct tone and white noise (WN) stimulus periods. To investigate how associative and non-associative mechanisms affect defensive responses, we compared this paired SCS-footshock group with four control groups that were conditioned with either pseudorandom unpaired presentations of SCS and footshock, shock only, or reversed SCS presentations with inverted tone-WN order, with paired or unpaired presentations. On day 2 of conditioning, the paired group exhibited robust freezing during the tone period with switching to explosive jumping and darting behaviors during the WN period. Comparatively, the unpaired and both reverse SCS groups expressed less tone-induced freezing and rarely showed jumping or darting during WN. Following the second day of conditioning, we observed how defensive behavior changed over two extinction sessions. During extinction, the tone-induced freezing decreased in the paired group, and mice rapidly shifted from escape jumping during WN to a combination of freezing and darting. The unpaired, unpaired reverse, and shock-only groups displayed defensive tail rattling and darting during the SCS, with minimal freezing and jumping. Interestingly, the paired reverse group did not jump to WN, and tone-evoked freezing was resistant to extinction. These findings demonstrate that non-associative factors promote some defensive responsiveness, but associative factors are required for robust cue-induced freezing and high-intensity flight expression.

Smokeless tobacco (snuff) and site-specific cancer risks in adult Black South African women: Findings from the Johannesburg Cancer Study.

Smokeless tobacco (SLT) use is an established carcinogen to the nasal cavity, lip, and oropharynx, however, few studies have examined cancer risks in older African women among whom SLT use is common. We investigated snuff use and the risk of site-specific cancers among 15,336 newly diagnosed female cancer patients in the Johannesburg Cancer Study, South Africa. We designed case-control comparisons across multiple cancer outcomes: (a) known SLT-associated cancers; (b) other tobacco-related cancers and (c) genital cancers owing to intravaginal snuff use. Controls (n = 2961) comprised all other cancer patients. We also investigated (d) each control cancer type versus the remaining controls to explore possible associations with other cancers. Logistic models were fitted to estimate odds ratios adjusted for age, education, tobacco smoking, alcohol, HIV, and language. Overall, ever use of snuff was 22% among control cancers. Ever snuff use was associated with cervical (OR 1.14 [95%CI 1.00-1.30]) and eye and adnexa cancer (OR 1.95 [95%CI 1.03-3.70]). Associations with vulva cancer were less clear, 95% CI's for the main effects included 1 but a subgroup analysis restricted to never-smokers of current-versus-never users was positive (OR 2.10 [95%CI 1.25-3.50]). Surprisingly SLT users have lower risks of stomach cancer (OR 0.60 [95%CI 0.37-0.99]) and Hodgkin Lymphoma (OR 0.48 [95%CI 0.23-0.97]). Snuff use may increase the risk for cervical and vulva cancer in women, which is plausible via intravaginal use. Further research on the impact of SLT on female genital cancers with more detailed exposure data, including timing, intensity, and routes of use are required.

Restraint to Induce Stress in Mice and Rats.

Across all animal species, exposure to stressful conditions induces stress responses. One method to study the effects of stress using rodent models is the restraint stress procedure. Restraint stress has been used for decades to investigate changes in physiology, genetics, neurobiology, immunology, and other systems impacted by stress. Due to the ease of performing the procedure, low cost, and numerous modifications to scale for the intensity and duration of stress exposure, a vast literature of studies has used restraint stress in mice and rats. As one example, this study presents previously published data showing the impact of restraint stress in transgenic mice on plasma corticosterone levels and optogenetically-induced norepinephrine release. Acute restraint stress increased plasma corticosterone levels, yet this effect was blunted in mice following repeat restraint stress. However, stimulated norepinephrine release in the bed nucleus of the stria terminalis was increased only in the repeat restraint stress group. These data highlight important considerations of restraint parameters on dependent measures. Additional descriptions of restraint stress in rats are also included for comparison. Finally, the influence of the parameters of the restraint (e.g., acute vs. chronic) and characteristics of the animal subjects (strain, sex, age) are discussed.

Neuroeffects of Microwave EMF Range of Non-Thermal Intensity and Short Exposure

The article presents a generalization and analysis of the results of many years of research by the author of the neuroeffects of weak electromagnetic effects in order to answer the questions: do they exist, what are their phenomenology, neurophysiological mechanism, ways of modification? Using electrophysiological and behavioral research methods, the line of effects of weak EMF from the neuron to the brain, the central nervous system (as a system) and the body is shown. In animal experiments and studies with the participation of volunteer testers, their phenomenology, dependence on parameters, modulation mode, and EMF organization are statistically substantiated. As a result, it is concluded that this is a common stimulus of the central nervous system, which in its influence on the body obeys the laws of physiology about the biological significance of the response, ways of its modification and adaptation mechanisms, which is advisable to take into account.

DPP-IV Inhibition by Solubilized Elastin Peptides from Yellowtail Bulbus Arteriosus Suppresses Ultraviolet-B-Induced Photoaging in Hairless Mice

Skin aging is intrinsic and extrinsic. Intrinsic, or chronological, skin aging is an inevitable process of chronological and physiological alterations. The factors contributing to extrinsic skin aging involve sunlight, nutrients, and stress. Thus, extrinsic aging is thought to be superimposed over intrinsic aging and depends on the intensity and duration of environmental exposure and skin type (e.g., dry skin, oily skin, or eczema). The most significant extrinsic aging factor is UV radiation, which causes cellular senescence in a process known as photoaging. This study aimed to illuminate the mechanism whereby solubilized elastin peptide lotion (EL) from the bulbus arteriosus of yellowtail (Seriola quinqueradiata) prevents skin photoaging in hairless mice. EL reduced wrinkle formation, epidermal skin thickness, and Ki67 (cell growth marker) mRNA expression in skin tissues from ultraviolet B (UVB)-irradiated mice. EL treatment also reduced glyoxalase-1 (key enzyme of glucose metabolism) levels in skin tissue. Although no significant differences in collagen and elastin contents were found in dermal areas, matrix metalloproteinase-12 (wrinkle-related marker) expression was reduced following EL application. Furthermore, skin DPP-IV/CD26 (new senescence marker) levels decreased following EL treatment in photoaging model mice. These results suggest that EL moderates skin damage caused by UVB irradiation by regulating senescence-related molecule expression.

Impact of Chronic Intermittent Hypoxia on Cognitive Function and Hippocampal Neurons in Mice: A Study of Inflammatory and Oxidative Stress Pathways.

Chronic intermittent hypoxia (CIH) is considered one of the main pathophysiological mechanisms of obstructive sleep apnea (OSA). CIH can further lead to cognitive dysfunction by inducing processes such as neuroinflammation and oxidative stress. The hippocampus is primarily associated with cognitive functions such as learning and memory. This study aimed to explore the effects of CIH on cognitive function and hippocampal neurons in mice and to reveal its potential molecular mechanisms. SPF-grade C57BL/6J mice (n=36) were selected as subjects and divided into control, mild CIH, and severe CIH groups (12 mice per group). Cognitive function was assessed using the Morris water maze test, and hippocampal neuron numbers and morphological changes were observed using HE staining and Nissl staining. Additionally, differential genes and pathways were revealed through RNA sequencing (RNA-seq) and bioinformatics analysis. We examined oxidative stress-related biochemical markers in the hippocampal tissue and used Western Blot to verify changes in the expression of potential key genes. Statistical analyses were performed using ANOVA and post hoc tests to ensure robust comparisons between groups. CIH mice exhibited significant cognitive impairment, including decreased learning and memory abilities. The severe CIH group had a longer escape latency compared to the mild CIH group (p < 0.001) and the control group (p < 0.01), while the mild CIH group took longer than the control group (p < 0.01). In the probe test, the severe CIH group showed a significant decrease in platform crossings (p < 0.01) and target quadrant dwell time (p < 0.05), while the mild CIH group exhibited a reduction in target quadrant dwell time (p < 0.05). Abnormal hippocampal neuron morphology was observed, with a significant reduction in hippocampal neurons (p < 0.05). RNA-seq analysis revealed numerous differentially expressed genes, mainly enriched in biological processes such as inflammation and oxidative stress, as well as multiple signaling pathways. Specifically, downregulated LepR, SIRT1, and Nrf2 genes were found to exacerbate oxidative stress and neuroinflammation, impairing neuronal integrity and cognitive function. Further validation showed increased oxidative stress levels in hippocampal tissue and downregulation of key gene expression. Western blot analysis confirmed significantly reduced expression of LepR (p < 0.01), SIRT1 (p < 0.001), and Nrf2 (p < 0.001) in the severe CIH group. While oxidative stress and inflammation are well-established mechanisms in CIH-induced cognitive impairment, our study provides novel insights by identifying the specific roles of LepR, SIRT1, and Nrf2 in this process. The downregulation of these key genes suggests potential new targets for therapeutic intervention. Importantly, the differential expression patterns observed in varying degrees of hypoxia severity highlight the potential for tailored therapeutic strategies that modulate these pathways in response to the intensity of hypoxic exposure. These findings offer unique opportunities for developing targeted therapies aimed at mitigating CIH-related cognitive decline and neural damage. However, a key limitation of this study is the exclusive use of animal models, which may not fully replicate human pathophysiology. Further studies are needed to validate these findings in clinical settings and to explore the regulatory relationships between the key genes involved.

The effect of supplemental LED lighting in the range of UV, blue, and red wavelengths at different ratios on the accumulation of phenolic compounds in pak choi and swiss chard

Phenolic compounds are known for their health-promoting effects on humans. Pak choi (Brassica rapa ssp. chinensis) and Swiss chard (Beta vulgaris subsp. vulgaris) are used here as model plants, as they are eaten raw as baby leaf lettuce and differ in their phenolic compound profile while showing similar morphology. In a greenhouse an artificial light source with UV-B (215 mW m−2), blue (104 μmol/m−2 s−1) and red (245 μmol/m−2 s−1) LEDs was implemented to increase phenolic compounds during the last days before harvest. Pak choi shows an increase or trend towards an increase in the monoacylated triglycosides of kaempferol and quercetin after 4 days of irradiation for 4 h each. For example kaempferol-3-caffeoyl-sophoroside-7-glucoside was increased at low PAR values in the third run and red-dominated light treatment by up to 120 %. In addition, it was observed that the red variety ‘Amur’ has higher concentrations of quercetin glycosides which were increased often. In swiss chard, on the other hand, there was only a sporadic increase in vitexin glycosides. Despite very different concentrations in some samples, 2″-glucosyl-vitexin and 2′′-glucosyl-6′′-malonyl-vitexin showed significant increases of up to 350 % in the two chard varieties Lukullus and Rhubarb chard. The results suggest that the exposure time or intensity of UV-B radiation needs to be optimized for each species and has not yet consistently led to an increase but trends in phenolic compounds and in antioxidant activity in this study.

Visible-light-programmed patterning in dynamically bonded cholesteric liquid crystal elastomer

Optical properties of cholesteric liquid crystal elastomers (CLCEs) can be tuned by an external field, however, it will spontaneously restore to the original state after the field is removed. Here, we introduce diselenide dynamic covalent bonds (DCBs) into CLCEs, whose optical properties can be reversibly and precisely tuned under the combined action of force and light. The tuned optical properties will be written into and remembered by the CLCEs, thus a programming effect is achieved. The prepared dynamical diselenide bonded CLCE films have the typical reversibly mechanochromism property, and high-resolution colourful patterning can be programmed by adjusting exposure time and intensity of masked visible-light under different tensile or compressive strain states. The DCB-CLCEs combine the novel anisotropy of CLCEs and the dynamic chain exchangeable ability of DCBs, which endows the materials with reprogrammable optical properties. We demonstrate a simple strategy of writing naked-eye high-resolution colourful patterning into a film with mechanochromism property by thermal or visible-light, it shows great potential in display devices, anticounterfeiting labels, sensors, optical films and smart materials.