Search Results (33,853)

Plate heat exchangers are used in heat substations for domestic hot water preparation and building heating in municipal central heating systems. Water from the municipal water supply is heated by hot water from a district heating network. This paper presents a numerical method for simultaneously determining heat transfer correlations on the cold and hot water sides based on flow-thermal measurements of the plate heat exchanger. The unknown parameters in the functions approximating the Nusselt numbers, which depend on the Reynolds and Prandtl numbers, are determined using the least-squares method, so the sum of the squares of the differences in the calculated and measured temperatures at the heat exchanger outlet reaches a minimum. One or two correlations were sought for a plate heat exchanger, and the total number of parameters sought is between three and six. The limits of the 95% confidence intervals for all estimated parameters were also determined. Correlations for Nusselt numbers determined experimentally for a clean plate heat exchanger can be used in the online monitoring of the degree of fouling of plate heat exchangers installed in the substations of a large urban district heating network. Full article

This paper proposes a new local thresholding method to further explore the relationship between gradients and image patterns. In most studies, the image gradient histogram is simply divided into K bins that have the same intervals in angular space. This kind of empirical approaches may not fully capture the correlation information between pixels. In this paper, a variance-based idea is applied to the gradient orientation histogram. It clusters pixels into subsets with different angular intervals. Analyzing these subsets with similar common patterns respectively will help to assist in achieving the optimal thresholds for image segmentation. For the result assessments, the proposed algorithm is compared with other 1-D and 2-D histogram-based thresholding methods, as well as hybrid local–global thresholding methods. It is shown that the proposed algorithm can effectively recognize the common features of the images that belong to the same category, and maintain the stable performances when the number of thresholds increases. Furthermore, the processing time of the present algorithm is competitive with those of other algorithms, which shows the potential application in real-time scenes. Full article

Background: Concerns exist regarding the lowest effective dose of opioids in opioid-naïve pregnancies. This study aimed to compare the effectiveness of 25 µg vs. 50 µg fentanyl in relieving labor pain. Methods: In total, 122 term-singleton pregnant females, who planned vaginal delivery, were randomized to receive 25 µg or 50 µg intravenous fentanyl, followed by hourly doses—as needed—for labor pain relief. The primary outcome was the comparison of pain score reduction 30 min after treatment between these regimens. Secondary outcomes included maternal and neonatal safety, total fentanyl dose administered, maternal satisfaction with the fentanyl dosing regimen, and breastfeeding, which were analyzed using appropriate statistical tests. Results: Within-group analysis revealed significant pain score reduction 30 min after fentanyl injection: −1.57 (95% confidence interval, CI −2.1 to −1.1, p < 0.001) and −1.69 (95% CI −2.2 to −1.2, p < 0.001) for 25 µg and 50 µg fentanyl groups, respectively. No significant differences in the pain reduction were observed in between-group comparisons (0.3, 95% CI −0.6 to 1.2, p > 0.999), including secondary maternal and neonatal outcomes. Total fentanyl dose was significantly lower in the 25 µg group compared with the 50 µg group (32.8 ± 13.3 vs. 60.2 ± 22.1, p < 0.001). Conclusions: A 25 µg intravenous fentanyl dose can reduce VAS score, used for evaluating labor pain 30 min after treatment, and is comparable to a 50 µg intravenous fentanyl dose. Given the efficacy of the reduced dosage of fentanyl, this study suggests using 25 µg intravenous fentanyl as an alternative initial dosing for labor pain relief. Full article

Antiretroviral therapy (ART) has significantly improved outcomes in individuals with human immunodeficiency virus (HIV), yet its long-term cardiovascular effects, especially on hypertension risk, remain debated. This pilot study investigated hypertension risk factors in HIV-positive patients undergoing ART and aimed at hypothesis generation rather than drawing definitive causal conclusions. Seventy HIV-infected adults without baseline hypertension were enrolled and followed. Hypertension was defined using the 2017 ACC/AHA guidelines by the South African Hypertension Society. Data on demographic, anthropometric, metabolic, inflammatory, coagulation, and HIV-related variables were collected. Cox regression analysis identified independent predictors of hypertension. Participants had a median age of 37 years (IOR = 10.96), with 84.3% being female. After a median ART exposure of 61.01 months (range: 2–164), 27 individuals (38.6%) developed high blood pressure. In multivariable Cox models adjusting for metabolic syndrome and BMI, age ≥ 35 years was associated with a 2.2-fold higher hypertension risk (Hazard Ratio [HR]: 2.2; 95% Confidence Interval [CI]: 1.04–4.55; p = 0.04). Elevated triglycerides significantly increased risk, with a 7.9-fold higher likelihood of hypertension (HR: 7.9; 95% CI: 1.04–59.5; p = 0.046). ART regimen type, whether initial or current, did not independently predict hypertension. In conclusion, hypertension is prevalent during ART. We hypothesized that traditional cardiovascular risk factors, notably age ≥35 years and hypertriglyceridemia, were key independent predictors, emphasizing the need for routine cardiovascular risk assessment in HIV management. Full article

Background/Objective: Neonatal respiratory distress syndrome (RDS) is a leading cause of morbidity and mortality in preterm infants. Interleukin-10 (IL-10) and endothelial nitric oxide synthase (eNOS, also known as NOS3) regulate inflammation and vascular tone, and genetic variants may influence the risk of RDS. To investigate the association between IL-10 rs1800872 (c.-149+1984T>G), IL-10 rs1800896 (c.-149+2474T>C), and NOS3 rs2070744 (c.-149+1691C>T), NOS3 rs1799983 (c.894T>G) variants and the risk of RDS in a Romanian cohort of preterm neonates. Methods: This case–control study included 340 preterm neonates (113 with RDS, 227 controls) born at <36 weeks of gestation. Genotyping was performed using TaqMan SNP assays. Logistic regression adjusted for gestational age and sex estimated odds ratios (ORs) and 95% confidence intervals (CIs). ROC analyses evaluated predictive performance. Results: No significant differences in genotype or allele distributions were observed between RDS and control groups for any variant. Haplotype analysis also revealed no association with RDS susceptibility or severity. NOS3:c.894T>G variant was associated with reduced risk of severe RDS after correction (adjusted p = 0.009), though survival analysis showed no significant genotype-specific effects. Epistatic genotype interaction was observed for the IL-10 T/G + T/C, present only in RDS (p = 0.0026). ROC analysis revealed a clinical prediction of RDS (AUC = 0.996), while the addition of genetic variants improved discrimination for severity (AUC = 0.865; 95% CI: 0.773–0.957) and mortality (AUC = 0.913; 95% CI: 0.791–1.000). Conclusions: IL-10 and NOS3 variants were not individually associated with overall RDS susceptibility. The observed epistatic interactions and the potential protective effect of NOS3:c.894T>G against severe forms can suggest modulatory roles in disease progression. Larger, ethnically homogeneous cohorts are needed to confirm these findings and assess their potential for informing personalized care for neonates. Full article

This work presents a novel time-to-digital converter based on the analog sampling of dual-phase periodic signals generated from a free-running oscillator. A proof-of-concept ASIC, implemented in 130 nm CMOS technology, achieves an average single-shot precision of 0.9 ps-rms for time intervals up to 3 ns, with a best performance of 0.79 ps-rms. It maintains a precision below 3.7 ps-rms for intervals up to 25 ns. The design demonstrates excellent linearity, with a peak-to-peak differential nonlinearity of 0.56 LSB and a peak-to-peak integral nonlinearity of 1.43 LSB. The free-running oscillator is shareable across multiple channels, enabling power consumption of approximately 4.1 mW per channel and efficient area utilization. These features make the design highly suitable for detection systems requiring picosecond-level precision and high channel density, such as silicon pixel sensors, SPADs, LiDARs, and time-correlated single-photon counting systems. Furthermore, the architecture shows strong potential for use in high-count-rate applications, reaching up to 22 Mcps. Full article

Background/Objectives: Tinnitus often occurs alongside the emotional symptoms of anxiety and depression. The Ginkgo biloba extract EGb 761^® was shown to be effective in reducing neuropsychiatric symptoms in elderly patients with both dementia and tinnitus, exerting direct effects on tinnitus severity and indirect effects mediated by improvement of anxiety, depression, and cognition. Whether the extent of the effects is influenced by the patient’s sex has not yet been investigated. We performed a conditional process analysis to evaluate this question. Methods: We analyzed the moderating role of sex on the direct and indirect effects of EGb 761^® on tinnitus severity using a first- and second-stage conditional process model. Results: Indirect effects of EGb 761^® on tinnitus severity mediated by improved cognition, anxiety, and depression did not differ between women and men (p > 0.05; all 95% bootstrap confidence intervals overlapped with zero). Moreover, direct treatment effects of EGb 761^® on tinnitus severity were statistically significant for both sexes (women, p < 0.0001; men, p = 0.0279). Conclusions: Beneficial effects of Ginkgo biloba extract EGb 761^® in dementia patients with tinnitus are likely to be unaffected by the patient’s sex. Further research into the influence of patient characteristics on the outcome of tinnitus drug treatment is encouraged. Full article

Background. Axillary lymph node biopsy (ALND) has traditionally been considered the gold standard for axillary staging and treatment in clinically node-positive breast cancer patients. However, in patients with nodal disease, the therapeutic benefit of ALND is uncertain. This study, based on a large cohort, aims to evaluate breast cancer-specific survival depending on the extent of axillary surgery in non-metastatic breast cancer using real-world data from the Surveillance, Epidemiology, and End Results (SEER) database. Methods. This retrospective cohort study comprised 825,240 patients diagnosed with breast cancer between 2000 and 2020. Results. ALND was associated with a worse survival outcome in pN0 and pN1 populations (respectively, hazard ratio [HR] 1.16; 95% confidence interval [CI] 1.12–1.2; p < 0.001 and HR 1.38; 95%CI 1.3–1.46; p < 0.001). In pN2 and pN3 populations, there was ~4.3% relative reduction in the hazard of breast cancer-related death for each additional node removed; and higher positive-to-removed lymph node ratio was associated with worse prognosis (HR 3.450; 95%CI 2.99–3.98; p < 0.001). Conclusions. SLNB is associated with significantly better specific survival compared to ALND in negative/low axillary involvement, in higher axillary involvement categories extensive axillary surgery was associated with better prognosis. Full article

This study explores advanced methods for analyzing the two-parameter alpha-power exponential (APE) distribution using data from a novel generalized progressive hybrid censoring scheme. The APE model is inherently asymmetric, exhibiting positive skewness across all valid parameter values due to its right-skewed exponential base, with the alpha-power transformation amplifying or dampening this skewness depending on the power parameter. The proposed censoring design offers new insights into modeling lifetime data that exhibit non-monotonic hazard behaviors. It enhances testing efficiency by simultaneously imposing fixed-time constraints and ensuring a minimum number of failures, thereby improving inference quality over traditional censoring methods. We derive maximum likelihood and Bayesian estimates for the APE distribution parameters and key reliability measures, such as the reliability and hazard rate functions. Bayesian analysis is performed using independent gamma priors under a symmetric squared error loss, implemented via the Metropolis–Hastings algorithm. Interval estimation is addressed using two normality-based asymptotic confidence intervals and two credible intervals obtained through a simulated Markov Chain Monte Carlo procedure. Monte Carlo simulations across various censoring scenarios demonstrate the stable and superior precision of the proposed methods. Optimal censoring patterns are identified based on the observed Fisher information and its inverse. Two real-world case studies—breast cancer remission times and global oil reserve data—illustrate the practical utility of the APE model within the proposed censoring framework. These applications underscore the model’s capability to effectively analyze diverse reliability phenomena, bridging theoretical innovation with empirical relevance in lifetime data analysis. Full article

To address the challenge of postharvest spoilage in flat peaches and white apricots, we developed fermented peach–apricot mixed juice (PAMJ) using these fruits as raw materials through multi-strain synergistic fermentation. Its fermentation processes were optimised through uniform design and single-factor experiments. The flavour characteristics of PAMJ were analysed using an electronic nose, an electronic tongue, gas chromatography–mass spectrometry (GC-MS) and sensory evaluation indices. PAMJ demonstrated optimal performance in terms of peach–apricot flavour profile, sweetness-sourness balance, and overall acceptability, achieving the highest sensory scores. Additionally, GC-MS analysis identified 116 volatile organic compounds, with PAMJ exhibiting the highest contents of terpenes and ketones. PAMJ was identified as the optimal fermentation matrix. Subsequently, response surface methodology was used to optimise its fermentation parameters. PAMJ represented a post-mixing fermentation system wherein peaches and apricots were initially mixed and subsequently fermented with a bacterial consortium comprising Limosilactobacillus fermentum (15%), Lactobacillus acidophilus (10%), Levilactobacillus brevis (34%), Lacticaseibacillus paracasei subsp. Tolerans (13%), Lactiplantibacillus plantarum subsp. plantarum (13%) and Limosilactobacillus reuteri (15%). After fermentation with an initial inoculum concentration of 5.2 × 10⁶ CFU/mL at 37 °C for 20 h, the initial soluble solid content of PAMJ increased from 16 to 16.5 °Brix, superoxide dismutase (SOD) activity increased from 250 to 295 U/mL and the number of volatile compounds (NVC) increased from 60 to 66. Furthermore, the storage stability of pasteurised PAMJ was evaluated by monitoring SOD and NVC at 5-day intervals. The data were analysed using kinetic and Arrhenius equations. The shelf life of PAMJ at 4 °C, 25 °C and 37 °C was 69, 48 and 39 days when NVC was used as the index and 99, 63 and 49 days when SOD activity was used as the index, respectively. These findings indicate that fermentation with lactic acid bacteria exerts positive effects on the quality of mixed juices, providing a novel strategy for processing speciality fruits in Xinjiang. Full article

Mitochondrial dysfunction is a key factor in the pathophysiology of major depressive disorder (MDD) and treatment-resistant depression (TRD), connecting oxidative stress, neuroinflammation, and reduced neuroplasticity. Physical exercise induces specific mitochondrial changes linked to improvements in mental health. The aim of this paper was to examine emerging evidence regarding the effects of physical exercise on mitochondrial function and treatment-resistant depression, highlighting the clinical importance of the use of mitochondrial biomarkers to personalize exercise prescriptions for patients with depression, particularly those who cannot tolerate standard treatments. Physical exercise improves mitochondrial function, enhances biogenesis and neuroplasticity, and decreases oxidative stress and neuroinflammation. Essential signaling pathways, including brain-derived neurotrophic factor, AMP-activated protein kinase, active peroxisome proliferator-activated receptor-γ coactivator-1α, and Ca²⁺/calmodulin-dependent protein kinase, support these effects. Most studies have concentrated on the impact of low- and moderate-intensity aerobic exercise on general health. However, new evidence suggests that resistance exercise and high-intensity interval training also promote healthy mitochondrial adaptations, although the specific exercise intensity required to achieve this goal remains to be determined. There is strong evidence that exercise is an effective treatment for MDD, particularly for TRD, by promoting specific mitochondrial adaptations. However, key gaps remain in our understanding of the optimal exercise dose and which patient subgroups are most likely to benefit from it (Graphical Abstract). Full article

Background and Objectives: Early gastric cancer (EGC) has an excellent prognosis when detected, yet miss rates during endoscopy remain high. Narrow-band imaging (NBI) enhances mucosal and vascular visualization and is increasingly used, but its benefit over white-light imaging (WLI) in high-risk patients is uncertain. This study aimed to compare NBI with WLI for the detection of gastric neoplasia in patients undergoing gastroscopy. Materials and Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), registered in PROSPERO (CRD42025649908) and reported according to PRISMA 2020 guidelines. PubMed, Scopus, and CENTRAL were searched up to October 2024. Eligible RCTs randomized adults undergoing gastroscopy for cancer surveillance or red-flag symptoms to NBI or WLI. Data extraction and risk of bias assessment were performed independently by two reviewers. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model, and certainty of evidence was graded with GRADE. Results: From 21 records, 3 RCTs comprising 6003 patients were included. NBI did not significantly increase gastric neoplasm detection compared with WLI (2.79% vs. 2.74%; RR = 0.98; 95% CI: 0.66–1.45; I² = 22%). Focal gastric lesion detection rates (14.73% vs. 15.50%; RR = 1.05; 95% CI: 0.72–1.52; I² = 87%) and positive predictive value (29.56% vs. 20.56%; RR = 1.29; 95% CI: 0.84–1.99; I² = 61%) also showed no significant differences. Risk of bias was high for blinding, and overall evidence certainty was low. In practical terms, both NBI and WLI detected gastric cancers at similar rates, indicating that while NBI enhances visualization, it does not increase the likelihood of finding additional cancers in high-risk patients. Conclusions: NBI did not significantly improve gastric neoplasm detection compared with WLI in high-risk patients, though it remains valuable for mucosal and vascular assessment. Larger, multicenter RCTs across diverse populations are required to establish its role in surveillance strategies. Full article

Purpose: We aimed to analyze the effects of age on human tear film (TF) using a novel nanometer resolution TF imaging device (Tear Film Imager, TFI, AdOM, Israel). Methods: 44 healthy adult subjects (≥18 years of age) without ocular or systemic diseases or prior eye treatments with ages spanning seven decades were enrolled in this prospective cross-sectional study. Subjects underwent a comprehensive ophthalmic examination and completed the Ocular Surface Disease Index questionnaire (OSDI). All study participants underwent TF imaging using the TFI, including assessment of muco-aqueous layer thickness (MALT), lipid-layer thickness (LLT), inter-blink interval, and lipid map uniformity. Associations between TFI parameters and age were tested using linear regression (accounting for multiple eyes). Results: A total of 80 eyes (44 subjects) were imaged: 19 eyes from 10 subjects in the 3rd decade of life (aged 20–29); 10 eyes from 5 subjects in the 4th decade of life (aged 30–39); 5 eyes from 3 subjects in the 5th decade of life (40–49); 12 eyes from 7 subjects in the 6th decade of life (50–59), 19 eyes from 11 subjects in the 7th decade of life (60–69); 11 eyes from 6 subjects in the 8th decade of life (70–79); and 4 eyes from 2 subjects in the 9th decade of life (80–89). With increasing age, MALT significantly decreased (p = 0.024), and LLT significantly increased (p = 0.001). No statistically significant linear age effects were found for the other TFI parameters (p > 0.05) or the OSDI scores of study participants of different ages (p = 0.786). Conclusions: Quantitative TF biomarkers varied significantly with advancing age in healthy individuals, highlighting the importance of accounting for age in TF assessments. Full article

This study investigates long-term changes in thermal comfort across the Italian and Iberian Peninsulas from 1940 to 2024, using the Universal Thermal Climate Index (UTCI) derived from ERA5-HEAT reanalysis. We apply a dual analytical framework combining structural break detection to identify regime shifts and Sen’s slope estimation with confidence intervals to quantify monotonic trends. Results reveal pronounced seasonal asymmetries. Summer exhibits abrupt regime shifts in both regions: in 1980 for Italy (slope shifting from −0.039 °C/year before 1980 to +0.06 °C/year after) and 1978 for Iberia (from −0.054 °C/year to +0.050 °C/year). Winter, by contrast, shows no structural breaks but a persistent, spatially uniform warming trend of ~0.030–0.033 °C/year across the 1940–2024 period, consistent with a gradual erosion of cold stress. Transitional seasons display more nuanced responses. Spring reveals detectable breakpoints in 1987 for Italy (shifting from −0.028 °C/year to +0.027 °C/year) and 1986 for Iberia (from −0.047 °C/year to +0.024 °C/year), indicating the early acceleration of warming. Autumn shows a breakpoint in 1970 for Italy, with trends intensifying from +0.011 °C/year before to +0.052 °C/year after, while Iberia exhibits no clear breakpoint but a consistent positive slope. These findings highlight spring as an early-warning season, where warming acceleration first emerges, and autumn as a consolidating phase that extends summer-like heat into later months. Overall, the results demonstrate that Mediterranean thermal regimes evolve through both abrupt and gradual processes, with summer defined by non-linear regime shifts, winter by steady accumulation of warming, and spring and autumn by transitional dynamics that bridge these extremes. The methodological integration of breakpoint detection with Sen’s slope estimation provides a transferable framework for detecting climate regime transitions in other vulnerable regions under accelerated global warming. Full article

The digital economy is a key driver of industrial upgrading and regional growth. Focusing on Gansu Province—an under-represented, less-developed region in northwest China—this study constructs a multidimensional digital economy index (DEI) for 2009–2023 under a unified normalisation and weighting scheme. Two complementary MCDA approaches—entropy-weighted TOPSIS and SESP-SPOTIS—are implemented on the same 0–1 normalised indicators. Robustness is assessed using COMSAM sensitivity analysis and is benchmarked against a PCA reference. The empirical analysis then estimates log-elasticity models linking modern logistics production (MLP) and the DEI to the provincial GDP and sectoral value added, with inferences based on White heteroskedasticity–robust standard errors and bootstrap confidence intervals. Results show a steady rise in the DEI with a temporary dip in 2021 and recovery thereafter. MLP is positively and significantly associated with GDP and value added in the primary, secondary, and tertiary sectors. The DEI is positively and significantly associated with GDP, the primary sector, and the tertiary sector, but its effect is not statistically significant for the secondary sector, indicating a manufacturing digitalisation gap relative to services. Cross-method agreement and narrow sensitivity bands support the stability of these findings. Policy implications include continued investment in digital infrastructure and accessibility, targeted acceleration of manufacturing digitalisation, and the development of a “digital agriculture–smart logistics–green development” pathway to foster high-quality, sustainable regional growth. Full article