Increase In Diameter Research Articles

Rapid trend towards larger and more moisture-limited trees in Central-European temperate forests

Abstract Tree stems represent a long-lived biomass compartment for atmospheric carbon sequestration. While terrestrial biosphere models predict rising carbon sequestration in forests, direct observations of tree growth are inconclusive due to varying standardization procedures of tree-ring series and complex factors influencing stem growth such as moisture and nutrient deficits and anthropogenic carbon and nitrogen fertilization. The mismatch between tree-ring-based observations, repeated inventories at permanent plots, and predictions of biospheric models represents a significant knowledge gap limiting forecasting of future forest growth. Using the novel approach free of tree-ring standardization trials and focusing on even-aged trees sampled from uneven-aged forest stands, we present a robust comparison of tree stem diameter changes in temperate forests between 1990 and 2015 along environmental gradients in Central Europe. The stem sizes of four out of five species showed significant enlargement while also partly increasing stem growth limitation due to moisture availability. The largest increase in stem diameter was recorded for late succession species on fertile sites. By contrast, the stem size of early-succession species on dry and nutrient-poor sites remained unaltered. Stems of mature trees in present-day forests are, on average, 8% thicker than their counterparts in 1990 consistent with trends predicted by terrestrial biosphere models. We demonstrated that, despite increasing drought limitation, temperate tree species enlarged their stems. Viewed in conjunction with older permanent plot data, Central-European temperate forests exhibited almost half century of continuous stem enlargement, potentially impacting forest functioning in terms of size-sensitive characteristics such as susceptibility to drought and disturbances.

Exogenous melatonin alleviates drought stress in cotton by enhancing root cortical activity and metabolic adaptation

IntroductionThe root cortex plays a critical role in water uptake and metabolic activity, directly influencing root functionality. However, despite melatonin’s known role in plant stress tolerance, its mechanisms in modulating root cortical anatomy and metabolic adaptation under drought remain unclear. This study examines the impact of exogenous melatonin on the root cortex of cotton under drought stress, focusing on its relationship with water uptake and drought resilience.MethodsCotton plants (cv. Lumian 532) were subjected to drought stress (8% PEG 6000) with foliar application of melatonin (100 μmol/L) to evaluate its effects on root cortical integrity and water uptake.ResultsThe results demonstrated that melatonin application significantly increased living cortical area (LCA) and cortical thickness of roots under drought stress, and the effect was more obvious near the middle segment of the root (13 cm from the root tip). Melatonin also enhanced osmotic regulation, increased respiratory enzyme activity, and improved specific root length uptake rates for water and key nutrients. Furthermore, melatonin promoted root and above-ground growth, as evidenced by increases in root length, plant height, stem diameter, and leaf area. Notably, LCA positively correlated with osmotic substance accumulation, root respiration, and absorption capacity under drought conditions.DiscussionIn conclusion, exogenous melatonin synergistically enhances drought resistance by maintaining cortical integrity, improving water absorption efficiency, and activating respiratory metabolism, thereby enhancing cotton growth and drought resistance. These findings underscore melatonin as a promising regulator for enhancing drought resistance.

Effectiveness of blue LED in enhancing hair treatments: Analysis in different hair ethnicities.

Effectiveness of blue LED in enhancing hair treatments: Analysis in different hair ethnicities.

Influence of head size and sex on the five-year survival of ceramic-on-ceramic hip resurfacing : an international multicentre study.

Ceramic-on-ceramic hip resurfacing (CoCHR) has been introduced to mitigate the risk of adverse tissue reactions associated with metal-on-metal hip resurfacing (MoMHR), particularly in females and smaller component sizes. This study evaluated: the survival of the ReCerf hybrid CoCHR up to five years; the impact of sex and component size on revision; and improvement in functional outcomes as measured by the Oxford Hip Score (OHS) and the University of California, Los Angeles Activity Scale (UCLA). An international retrospective study included 604 consecutive patients (336 males, 268 females; mean age 50.1 years (20 to 80)) who underwent CoCHR from September 2018 to January 2023. Kaplan-Meier analysis assessed up to five-year survival, with log-rank tests comparing outcomes by sex and femoral head size. Cox proportional hazards regression quantified revision risk. Mean follow-up was 4.04 years (1.44 to 6.35). Survival in 128 hips which had five-year follow-up was 98.0% (95% CI 96.3 to 99.0): 97.6% for males (95% CI 94.7 to 98.9), 98.5% for females (95% CI 96.0 to 99.4), 98.5% for femoral head sizes < 50 mm (95% CI 96.1 to 99.4), and 97.5% for head sizes ≥ 50 mm (95% CI 94.6 to 98.8). Females had a revision hazard ratio (HR) of 0.79 (95% CI 0.14 to 4.26; p = 0.780) and an increase in head diameter by 1 mm of 1.01 (95% CI 0.83 to 1.23; p = 0.890), demonstrating no significant impact of sex or head size on revision incidence. Significant improvements in OHS and UCLA scores were observed for all patients (preoperative OHS 22.3 (SD 8.4) and postoperative OHS 45.0 (SD 4.1); preoperative UCLA 4.96 (SD 2.2) and postoperative UCLA 7.97 (SD 1.7)). CoCHR demonstrated excellent patient-reported outcome improvement and survival up to five years, irrespective of sex or implant size, comparing favourably to MoMHR. Longer-term follow-up is required to confirm these outcomes.

Machine learning prediction of the Morison equation coefficients

Abstract Prediction of forces on cylindrical structures in marine environments such as jacket platforms and monopiles typically relies on the Morison equation. The Morison equation relies on two coefficients to accurately predict the magnitude of the inertial and drag forces experienced by the structure. These coefficients are sensitive to the diameter and the external shape of the cylinders. Both of these factors change in the presence of biocolonization through an increase in diameter and in macro-roughness. This paper details how machine learning can be used to estimate these cofficients in a number of scenarios and demonstrates the applicability through experiments in a wave basin. Several machine learning methods are compared. The approach allows for improved accuracy of force estimates when assessing loads on marine structures, especially for scaled testing in wave basins, where progression of technological readiness is typically done. The benefit of this approach, as opposed to the current binary approach of rough or smooth structures, is that we can examine the evolution of force over time allowing for improved estimates of fatigue lifetimes or improved maintenance cycles.

A Rare Case of Apert Syndrome in a Tanzanian Newborn: Diagnosis and Management Challenges in a National Tertiary Hospital

Introduction: Apert syndrome is a rare congenital condition characterized by coronal craniosynostosis, ex orbitism, midface hypoplasia as well as symmetric syndactyly of both feet and hands. This condition is also known as acrocephalosyndactyly type 1. Apert syndrome is linked by autosomal dominant inheritance to fibroblast growth factors receptor gene alteration. Case Report: This is the case report of a 42 days old baby who presented with classical facial features of Apert syndrome. Syndactyly of both fingers and toes. He was born from non-consanguineous parents, his father being 44 years old when the baby was born. An X-ray of the skull revealed increase in anterior posterior diameter of the skull, while cranial ultra sound depicted no evidence of space occupying lesions, no evidence of extra axial collection with no signs of midline shift. X-ray of hands and feet revealed the pathognomonic syndactyly of the disease. Conclusion: There is a paucity of data about Apert Syndrome in African countries. Which poses the emphasis on the advocacy of this condition in African countries for more cases to be reported to capacitate the healthcare workers to diagnose and treat this rare condition properly. Given the limitations of genetic testing and prenatal screening in the region, this case call for action for the need to increase awareness, early intervention and genetic counseling to guide treatment decisions and improve outcomes.

Comparative Study of Single- Versus Double-ProGlide Device Strategy for Access Site Closure of Transfemoral Transcatheter Aortic Valve Replacement.

Transcatheter aortic valve replacement (TAVR) is a first-line treatment for severe symptomatic aortic stenosis (AS) patients, and the preferred approach for TAVR is transfemoral. The double-ProGlide preclose technique offers an effective and safe method for closure of transfemoral access site after TAVR. However, the debate is still ongoing whether a single-ProGlide strategy is equal or even superior to a double one in terms of hemostasis and vascular complications. The aim of this study is to examine the safety and efficacy of a single- versus double-ProGlide strategy for vascular closure during transfemoral TAVR. Patients with severe AS who underwent transfemoral TAVR in the second affiliated hospital Zhejiang university school of medicine in the period from June 2021 to December 2023 were included and divided by the number of ProGlide device. The primary outcome of this study was a composite of in-hospital main access route related vascular complications, main access route related bleeding, and vascular closure device failure in accordance with Valve Academic Research Consortium-3 (VARC-3) criteria. The propensity-score matched (PSM) analysis was used to account for differences in baseline characteristics, and binary logistic regression was used to determine the predictive factors for the primary outcome. A total of 347 patients were included, of which 154 (44.0%) had a single ProGlide device used for arteriotomy closure, and 193 (56.0%) had a double one. After PSM, the incidence of primary composite outcome was significantly lower in the single-ProGlide group (7.7% vs. 17.9%, p = 0.023), while the incidence of in-hospital vascular complications (6.0% vs. 11.1%, p = 0.210) and bleeding (1.7% vs. 6.8%, p = 0.109) related to the main access route was lower but not significant. Multivariate logistic regression showed that single-ProGlide (for double-ProGlide, OR = 0.408, 95% CI = 0.182-0.914, p = 0.029) and an increase in the minimal lumen diameter of main access route (per 1.0 mm, OR = 0.618, 95% CI = 0.416-0.919, p = 0.017) were protective factors for the primary outcome. A single-ProGlide device is a safe and effective mean of vascular closure after transfemoral TAVR and may have important clinical benefits compared to the commonly used double-ProGlide technique.

Immunohistochemical Analysis of Mastocyte Inflammation: A Comparative Study of COPD Associated with Tobacco Smoking and Wood Smoke Exposure

Background: Chronic Obstructive Pulmonary Disease (COPD) exhibits some phenotypic differences between patients with biomass smoke inhalation (COPD-B) and tobacco smoking (COPD-T). COPD-B is characterized by less emphysema but more airway disease and vascular pulmonary remodeling, which are related to mast cells in lung tissues in COPD-T. Our objective was to describe the differences between the number of mast cells in COPD-B and COPD-T patients. Methods: A cross-sectional study was conducted on lung tissue resections for suspected cancer obtained between 2014 and 2021 from patients with documented COPD due to wood smoke or tobacco exposure. Histological samples were analyzed for mast cell count, CD34+ expression, and structural changes in lung tissue and pulmonary circulation. Results: A total of 20 histological samples were analyzed, with significant differences found in mast cell count [median 8 (p25-75, 5–11) vs. 2 (p75-25, 0–6), p = 0.016] and severe peribronchiolar fibrosis (60% vs. 10%, p = 0.04) between COPD-B and COPD-T patients. A positive correlation [Spearman rho = 0.879 (95% CI 0.71–0.96), p &lt; 0.001] was observed between mast cell count and a gradual increase in pulmonary artery diameter. Conclusions: These preliminary findings suggest histological differences and the presence of mast cells between COPD-B and COPD-T, which should be confirmed in a larger number of samples and patients.

Classification of Acoustic Characteristics of Bubble Flow and Influencing Factors of Critical Gas Flow Velocity

To address the unclear coupling mechanism between bubble detachment behavior and acoustic characteristics in gas–liquid two-phase flow, this paper systematically studied bubble behavior and acoustic characteristics under different conditions by building a high-precision synchronous measurement system, combining acoustic signal analysis and bubble dynamics observation. The influence mechanism of liquid surface tension, dynamic viscosity, and orifice diameter on the critical gas flow velocity of bubble flow transition was analyzed, and a flow pattern classification criterion system was established. The experimental results showed that the bubble flow state could be divided into three states according to the characteristics of the acoustic signals: discrete bubble flow, single-chain bubble flow, and dual-stage chain bubble flow. The liquid surface tension and dynamic viscosity had no significant effect on the critical gas flow velocity of the transition from discrete bubble flow to single-chain bubble flow, but significantly increased the critical gas flow velocity of the transition from single-chain bubble flow to dual-stage chain bubble flow. The increase in the orifice diameter reduced the critical gas flow velocity of the two types of flow transition. In addition, the Weber number (We) and Galileo number (Ga) were introduced to construct a quantitative classification system of flow pattern, which provided theoretical support for the optimization of industrial gas–liquid two-phase flow.

Combination of Polydopamine and Plasma Oxidation Increases Tissue Integration of Polyurethane-Silicone Copolymers for Cardiovascular Implants.

Polyurethane (PU)-silicone co-polymers are increasingly favored in medical applications due to their excellent biostability and durability; however, their intrinsic hydrophobicity limits tissue integration. Polydopamine (PDA) deposition is a widely accepted method for increasing biomaterial surface hydrophilicity, though concentrations and methods vary across published literature. This study investigates the synergistic effects of PDA deposition and plasma oxidation on FDA-approved Elast-Eon E2A (E2A) to enhance cell attachment and wound healing. E2A substrates are treated with a range of plasma oxidation periods and PDA concentrations (0-5 min, 0-0.5 w v-1% respectively). The combination of 0.05 w v-1% PDA and 1-minute oxygen plasma results in the most significant reduction in water contact angle (92to 19°), increase in fibroblast adhesion (33.0-53.2 cells mm-2) and cell diameter, with an overall increase in intra- and extracellular collagen I and fibronectin. X-ray photoelectron spectroscopy (XPS) reveals significant surface chemical changes, while surface roughness remains unchanged. Whole blood adhesion tests show no change inplatelet adhesion or volume. These parameters may offer an improved approach for modifying PU-copolymers to enhance cell interactions for use in current and future medical implants, including a suite of cardiovascular technologies that require both material ductility and rapid tissue integration.

Cell death-inducing DFF45-like effector C intervenes the progression of non-small cell lung cancer via modulating lipid metabolism.

The cell death-inducing DFF45-like (CIDE) effector family, plays a crucial role in lipid droplet formation and stability. Its N-terminal and C-terminal domains are closely linked to cell apoptosis and lipid droplet growth. However, the expression and functional role of CIDEC in non-small cell lung cancer (NSCLC) remain unexplored. This study aims to investigate the expression patterns and functional implications of CIDEC in NSCLC, with a particular focus on its role in lipid droplet metabolism and tumor progression. We analyzed CIDEC expression levels in NSCLC tissues compared to normal lung tissues using immunohistochemistry and quantitative PCR. To elucidate the functional role of CIDEC, we performed in vitro and in vivo experiments involving overexpression and knockdown of CIDEC in NSCLC cell lines. Proliferation, invasion, and migration assays were conducted to assess the impact of CIDEC on tumor cell behavior. Additionally, lipid droplet morphology and triacylglycerol (TAG) content were evaluated using fluorescence microscopy and biochemical assays. The expression of ATGL, a downstream gene of CIDEC, was also measured to explore the mechanistic link between CIDEC and lipid droplet lipolysis. Our findings revealed that CIDEC expression was significantly downregulated in NSCLC tissues compared to normal tissues. Functionally, overexpression of CIDEC inhibited the proliferation, invasion, and migration of NSCLC cells both in vitro and in vivo. Furthermore, CIDEC overexpression led to an increase in lipid droplet diameter and TAG content, whereas CIDEC knockdown resulted in the reduction and fragmentation of large lipid droplets. Mechanistically, CIDEC deficiency was associated with increased ATGL expression and reduced lipid droplet content, while CIDEC overexpression correlated with elevated TAG levels and decreased ATGL protein levels. These results suggest that low CIDEC expression in NSCLC promotes tumor progression by enhancing ATGL-mediated lipolysis. This study is the first to establish a link between CIDEC expression and lipid droplet lipolysis in NSCLC. Our findings indicate that CIDEC plays a critical role in regulating lipid metabolism and tumor progression in lung cancer. The downregulation of CIDEC in NSCLC promotes tumorigenesis by enhancing ATGL-induced lipolysis, highlighting CIDEC as a potential therapeutic target for lung cancer through metabolic reprogramming of lipid droplets. These insights provide a novel direction for targeted treatment strategies in NSCLC.

The Influence of Opioids on Pupil Initial Diameter and Pupillary Dilation Velocity in ICU Patients

ABSTRACTBackgroundPupillary light reflex assessment is a promising modality for assessing autonomic nervous system status, given that it is fast, noninvasive, and provides quantitative results. Opioid therapy influences the pupil and is frequently used in the intensive care unit (ICU). We investigated the effect of opioids on pupillary size and dilation velocity in the pupillary light reflex in critically ill patients.MethodsThis is a sub‐study on 55 patients from a prospective observational study acutely admitted to an ICU. All patients had daily blood samples and pupillary light reflex measurements. Blood samples were analyzed for opioids using mass spectrometry. Linear mixed models were used to estimate the possible association for each detected opioid to pupillary size and dilation velocity in the pupillary light reflex.ResultsThe pupil size before a light stimulus was closely associated to the dilation velocity after the light stimulus. The increase in the dilation velocity was 0.2 mm/s per 1 mm increase in pupil diameter before the light stimulus, 95% confidence interval [0.2–0.3], p < 0.001. Presence of fentanyl was associated with a smaller pupil size and a slower pupillary dilation velocity.ConclusionsThe presence of fentanyl in blood samples from a mixed ICU population is associated with a slower pupillary dilation velocity in a concentration‐dependent matter.Editorial CommentThis study assesses the relation of observed opioid levels and light reflex pupillary size speed of change in an ICU cohort where there can be multiple classes of drugs present which influence autonomic nerve system function. Findings for different opioids, though most specifically fentanyl, show that opioid plasma concentrations have clear association with slower pupillary dilation velocity with light reflex response.

Webbed skin of the posterior labial commissure: A rare cause of dyspareunia: A case report.

Dyspareunia is a common disease affecting the physical and mental health of individuals. There are several reasons for dyspareunia. It is essential to identify the causes of dyspareunia and to implement targeted treatments. The patient was a 26-year-old married woman who presented with dyspareunia lasting for several months, and never successfully engaged in sexual intercourse. She had a webbed skin with a scar at the posterior labial commissure from the 5 o'clock position to the 7 o'clock position of the vaginal opening, partially blocking it. This case presented a rare cause of dyspareunia. In this case, we designed a five-flap method to extend the skin length of the vaginal opening and solved the problem of obscuration of the patient's vaginal opening. After surgery, the vaginal opening appeared normal, with an apparent increase in diameter, and the incision was recovered. In this case, we attempted a five-flap plasty on the webbed skin of the posterior labial commissure, and the outcome was satisfactory. This demonstrates the potential of this new treatment. This case report can help clinicians broaden their treatment options.

Effects of Hole Irrigation Device Parameters on Soil Water Characteristics Under Different Biogas Slurry Ratios

This study investigates the impact of biogas slurry ratio, hole diameter and depth under hole irrigation on the soil wetting front migration distance and cumulative infiltration. In this study, a model describing the water transport characteristics of biogas slurry hole irrigation was developed based on the HYDRUS model. Results demonstrated that the HYDRUS model can be used for biogas slurry hole irrigation (NSE &gt; 0.952, PBIAS ≤ ±0.34). Furthermore, the study revealed that the soil cumulative infiltration and soil wetting front migration distance decreased gradually with an increase in the biogas slurry ratio, while they increased gradually with an increase in the hole diameter and depth. The lateral and vertical wetting front migration distances exhibited a well-defined power function relationship with the soil’s stable infiltration rate and infiltration time (R2 ≥ 0.977). The soil wetting front migration distance curve can be represented by an elliptic curve equation (R2 ≥ 0.957). Additionally, there was a linear relationship between the cumulative infiltration and soil wetted body area (R2 ≥ 0.972). Soil wetting front migration distance model (X=4.442f00.375t0.24, Z=11.988f00.287t0.124, f0=96.947Ks1.151D0.236H1.042, NSE &gt; 0.976, PBIAS ≤ ±0.13) and cumulative infiltration model (I=0.3365S, NSE &gt; 0.982, PBIAS ≤ ±0.10) established under biogas slurry hole irrigation exhibited good reliability. This study aims to determine optimal hole diameter, depth, and irrigation volume for biogas slurry hole irrigation by establishing a model for soil wetting front migration distance and cumulative infiltration based on crop root growth patterns, thereby providing a scientific basis for its practical application.

Comparison of Acute Effects of Classical Massage and Connective Tissue Massage on Lower Extremity Blood Flow Changes

This study aimed to compare the immediate effects of connective tissue massage and classical massage on lower extremity blood circulation in healthy adults, and to better understand the mechanism of connective tissue massage. Twenty healthy participants underwent a 40-minute classical massage on the left lower limb. One week later, the same individuals received a connective tissue massage. Using color Doppler ultrasound, the diameter, flow velocity, and blood volume of the popliteal and posterior tibial arteries were measured before and after each session. Both massage methods led to significant increases in blood flow velocity, vessel diameter, and blood volume (p

Electrospun PLA/PBS/MWCNT nanocomposite fibers for high-performance air filtration: A sustainable approach

For the development of high-performance air filtration materials, electrospun polylactic acid (PLA)/polybutylene succinate (PBS) blend fibers, reinforced with multi-walled carbon nanotubes (MWCNTs), were fabricated and subjected to comprehensive characterization. A PLA/PBS blend, at a 95/5 wt% ratio, was prepared through the dissolution of the constituent polymers in a dichloromethane/dimethylformamide mixture, using a 3:1 v/v ratio at a 17 wt% concentration. MWCNTs were introduced into the polymer solution, with dispersion facilitated by a Triton X-100 surfactant and ultrasonication, at concentrations ranging from 0 to 4 wt%. Electrospinning was performed under optimized conditions, specifically an applied voltage of 16 kV and a tip-to-collector distance of 18 cm. Upon the incorporation of MWCNTs, minor alterations to fiber morphology were observed, including a slight increase in fiber diameter and an enhancement in the uniformity of surface pore distribution. Thermal properties were analyzed, revealing a trend of decreasing glass transition temperature, melting temperature, and thermal stability as the MWCNT content increased. Mechanical properties were evaluated, with improvements in tensile strength and Young's modulus documented with increasing MWCNT content. Filtration efficiency was assessed, and significant enhancements were achieved, with performance comparable to N95 masks (98-99%) recorded. Notably, a reduction in pressure drop across the filters was observed with increasing MWCNT content, indicating improved breathability. The potential of these biodegradable and environmentally sustainable nanocomposite fibers as an alternative to conventional filtration materials, addressing the growing concerns surrounding air pollution, is demonstrated by these results. This study highlights the feasibility of employing biopolymers and carbon nanomaterials for a more sustainable approach to air filtration, offering a viable solution for developing advanced, eco-friendly filtration technologies.

The possibility of using osteopathic correction in the complex therapy of patients with chronic telogen hair loss

Introduction. Diffuse alopecia accounts for up to 40 % of all alopecia cases, making it one of the most common reasons patients consult dermatologists and cosmetologists. The pathogenesis of chronic telogen hair loss (CTHL) remains incompletely understood, and the changes occurring in hair follicles are heterogeneous in both pathogenetic and histological terms, rendering the treatment of this condition a significant challenge for clinicians. This underscores the importance of further research in this fi eld and the search for effective therapies, one of which may involve osteopathic correction.The aim of the study: to evaluate the feasibility of incorporating osteopathic correction into the combined treatment of female patients with CTHL.Materials and methods. A prospective controlled randomized study was conducted at the «Vash Doctor» Clinic (Moscow region, Odintsovo) from January 2024 to September 2024. The study included 58 female patients diagnosed with telogen alopecia. Using randomization envelopes, participants were divided into two equal groups of 29 patients each: the main group and the control group. Patients in both groups received conventional combined conservative treatment as prescribed by a dermatologist. Patients in the main group additionally underwent osteopathic correction — 3 sessions at 14-day intervals.Results. In patients with CTHL, a reduction in hair density per cm2 and hair diameter was observed, accompanied by decreased mechanical strength. Subclinical levels of depression and anxiety were also recorded. Despite the diverse etiological factors of CTHL no predominant somatic dysfunctions were identified in the osteopathic status of the study group. Both treatment regimens demonstrated clinical efficacy, with statistically significant increases in hair diameter and mechanical strength (p&lt;0,01). However, the inclusion of osteopathic correction resulted in a statistically significant increase in hair density per cm2 (p&lt;0,01) and significantly higher mechanical strength values (p&lt;0,05).Conclusion. Incorporating osteopathic correction into the combined treatment of female patients with CTHL yields statistically more significant improvements in hair density per cm², mechanical strength, and reductions in depression and anxiety levels compared to conventional therapy alone. Further research in this area appears promising.

Quantitative Evaluation of Mechanical Properties of Hydrogen Transmission Pipelines Based on Weak Magnetic Detection

With the rapid development of the hydrogen energy industry, long-distance hydrogen transportation based on natural gas pipelines has emerged as a crucial technique. However, exposure to a hydrogen environment can lead to the degradation of pipeline mechanical properties, resulting in hydrogen corrosion, which may increase the risk of pipeline failure. Consequently, it is crucial to evaluate the mechanical properties of pipeline steel under a hydrogen environment to ensure pipeline safety. In this paper, hydrogen corrosion experiments for X80 pipeline steel are carried out with varying hydrogen charging times. Through tensile fracture experiments and weak magnetic detection technology, the effects of defects and hydrogen concentration on the stress–strain characteristics and magnetic signal characteristics of X80 steel are investigated. Based on the correlation level, the quantitative relationships between hydrogen concentration, magnetic signal characteristics, and mechanical properties are established, and the sparrow search algorithm (SSA) is utilized to modify these quantitative relationships. The results indicate that with the increase in defect depth, the magnetic signal characteristics gradually increase. With the increase in defect diameter, these parameters gradually decrease. The modified quantitative relationships provide the accurate assessment of the ultimate bearing capacity, yield strength, and ultimate tensile strength, with average relative errors of 7.91%, 3.15%, and 2.04%, respectively. This study provides a theoretical basis for ensuring the safe transportation of hydrogen transmission pipelines.

Changes in Retinal Vasculature Phenotype and Choroidal Blood Flow at High Altitude in Healthy Lowlanders

PurposeThe aim of this study was to characterize changes in retinal vessel diameters and choroidal blood flow in healthy lowlanders during a high-altitude expedition.MethodsOcular examination, fundus images acquired using a handheld camera, and laser Doppler flowmetry (LDF) measurements within the subfoveal choroid (blood flow = ChBF, blood velocity = ChVel, and blood volume = ChVol) were carried out at 200 m and after 9 days at 5100 m in 11 healthy participants. Fundus images were analyzed with the semi-automatic software Vessel Assessment and Measurement Platform for Images of the Retina (VAMPIRE) version 3.2 to quantify retinal vessel parameters: the central retinal artery equivalent (CRAE), the central retinal vein equivalent (CRVE), and arterial and venular tortuosity. Hematocrit and hemoglobin concentrations were also measured at both altitudes.ResultsCorneal thickness increased slightly at altitude (median = 536 µm, interquartile range = 25–75%: [521–571] at 200 m vs. 561 µm [540–574] at 5100 m, P = 0.004). No participant was affected by high-altitude retinopathy. From 200 m to 5100 m, ChVol and ChBF decreased significantly (−31% [43–22], P = 0.003 and −13% [22–8], P = 0.01, respectively), ChVel increased (+17% [10–44], P = 0.003), and CRVE (+10% [3–14], P = 0.04) and venular tortuosity (+142% [71–168], P = 0.04) increased significantly. The altitude-induced increase in hematocrit correlated negatively with the decrease in ChBF (r = −0.88, P < 0.001) and positively with the increase in CRVE (r = 0.88, P = 0.01).ConclusionsAcute high-altitude exposure leads to a decrease of ChBF (partly related to a decrease in blood volume) and an increase in retinal vein diameter and tortuosity. The physiological consequences of these changes on retinal blood flow and retinal function remain to be explored.

Long-term natural course of avascular serous pigment epithelial detachment in age-related macular degeneration.

To investigate the long-term natural history of avascular serous pigment epithelial detachment (PED) in age-related macular degeneration (AMD) and identify risk factors for choroidal neovascularization (CNV) development. This retrospective study analyzed 71 eyes from 50 patients with pure avascular serous PED due to AMD, diagnosed via fluorescein angiography and indocyanine-green angiography. Patients were followed for at least 12 months (mean follow-up: 54.9 months). Baseline and follow-up assessments included best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) measurements of PED height and diameter. Disease progression was categorized as stable, atrophic, or CNV development, and statistical analyses identified CNV risk factors. Among studied eyes, 15.5% developed CNV, 21.1% progressed to atrophy, and 63.4% remained stable. Larger baseline PED height and diameter significantly correlated with CNV risk (p=0.004 and p=0.003, respectively). Every 100μm increase in PED height and diameter raised CNV risk by 50% and 10%, respectively. BCVA declined in all groups, with greater deterioration in CNV and atrophic cases. Larger PED height and diameter are significant CNV risk factors in avascular serous PED. OCT-based monitoring is crucial for early detection of high-risk cases, optimizing clinical management, and preventing vision loss in AMD patients.