Search Results (41)

Heart failure (HF) and left ventricular hypertrophy (LVH) are linked to fibroblast growth factor 23 (FGF23). This study aims to analyze whether FGF23 can predict postoperative outcomes in unselected left ventricular assist device (LVAD) candidates. Methods: We conducted a prospective observational study that included 27 patients (25 HeartMate3 and 2 HeartMateII) with a median follow-up of 30 months. We measured preoperative FGF23 plasma levels and computed the HeartMateII risk score (HMRS), the HeartMate3 risk score (HM3RS) and the EuroSCOREII with respect to postoperative mortality, as well as the Michigan right heart failure risk score (MRHFS), the Euromacs RHF risk score (EURORHFS), the CRITT score with respect to RHF prediction and the kidney failure risk equation (KFRE) with respect to kidney failure. Multivariate logistic regression and receiver operating characteristic (ROC) analyses were performed. Results: In the multivariate logistic regression, preoperative FGF23 level was found to be a predictor of postoperative RHF (OR: 1.37, 95-CI: 0.78–2.38; p = 0.031), mortality (OR: 1.10, 95%-CI: 0.90–1.60; p = 0.025) and the need for postoperative dialysis (OR: 1.09, 95%-CI: 0.91–1.44; p = 0.032). In the ROC analysis, FGF23 as a predictor of post-LVAD RHF had an area under the curve (AUC) of 0.81. Conclusions: FGF23 improves the prediction of clinically significant patient outcomes—such as need for dialysis, RHF and mortality—after HM3 and HMII implantation, as adding FGF23 to established risk scores increased their predictive value. Full article

In this paper, we introduce and develop the concept of osculating curve pairs in the three-dimensional Minkowski space. By defining a vector lying in the intersection of osculating planes of two non-lightlike curves, we characterize osculating mates based on their Frenet frames. We then derive the transformation matrix between these frames and investigate the curvature and torsion relations under varying causal characterizations of the curves—timelike and spacelike. Furthermore, we determine the conditions under which these generalized osculating pairs reduce to well-known curve pairs such as Bertrand, Mannheim, and Bäcklund pairs. Our results extend existing theories by unifying several known curve pair classifications under a single geometric framework in Lorentzian space. Full article

Background/Objectives: In the context of acute heart failure, proenkephalin A (penKid) has emerged as a prognostic marker for acute kidney injury (AKI), whereas bioactive adrenomedullin (bio-ADM) has been identified as a significant biomarker linked to shock and organ dysfunction. This raises the question of whether they can serve as predictors of postoperative complications in patients receiving left ventricular assist devices (LVADs). Methods: This observational study prospectively enrolled patients who had received LVAD implantation. Routine laboratory values as well as plasma levels of penKid and bio-ADM were assessed at four time intervals, spanning from preinduction of anesthesia to 48 h post surgery. Clinical data, the HeartMate 3-risk-score (HM3RS), HeartMateII-risk-score (HMRS), Michigan-right-heart-failure risk score (MRHFS), Euromacs-RHFS (EURORHFS), and kidney failure risk score (KFR) were calculated. Multivariate logistic regression and receiver operating characteristic (ROC) analysis were performed. We entered the biomarkers with the established risk scores into the models. Results: In 20 patients who had undergone LVAD implantation, preoperative penKid level was a predictor of postoperative AKI (OR: 1.05, 95%-CI: 1.0–1.09; p = 0.049) and 30-day mortality (OR: 1.01, 95%-CI: 1.0–1.02; p = 0.033). Bio-ADM was the only predictor of postoperative right heart failure (RHF) (OR: 1.11, 95%-CI: 1.01–1.23; p = 0.034) and rehospitalization (OR: 1.06, 95%-CI: 1.0–1.13; p = 0.047). In the ROC analysis, bio-ADM, as a predictor of post-LVAD RHF, had an area under the curve (AUC) of 0.88. When bio-ADM was added to the accepted clinical scores for post-LVAD RHF prediction (CRITT-score, MRHFS, and EURORHFS), the AUC reached 0.98. The AUC for preoperative penKid, as a predictor of postoperative AKI, was 0.95, and after adding its predictive value to the KFR score, the AUC reached 0.97. Conclusions: In the present study, the biomarkers penKid and bio-ADM predicted clinically significant patient outcomes after LVAD implantation such as AKI, RHF, and 30-day mortality. Adding biomarkers to well-established risk scores improved the AUC for prediction of postoperative complications. Full article

This study investigated the levels of four polycyclic aromatic hydrocarbons (BaA, CHR, BbF, and BaP) in 11 types of 100 commercially available tea products using gas chromatography–mass spectrometry (GC-MS), and also evaluated potential dietary risks, toxic equivalency (TEQ), and margin of exposure (MOE). Method validation demonstrated strong linearity of the calibration curves for all four PAHs (R² > 0.99) over a concentration range of 1–20 μg/kg. The LOD for the four PAHs ranged from 0.0610 to 0.1534 μg/kg in the solid matrix and from 0.0035 to 0.0064 μg/kg in the liquid matrix, with corresponding LOQ ranging from 0.1849 to 0.4648 μg/kg in the solid matrix and from 0.0107 to 0.0194 μg/kg in the liquid matrix. All recovery rates were within the acceptable range, demonstrating satisfactory performance, and both intraday and interday accuracy and precision were within acceptable limits, meeting international validation criteria. Among the samples, yerba mate tea (33.58 μg/kg), herbal tea (24.05 μg/kg), and oolong tea (23.21 μg/kg) showed the highest Σ4PAH concentrations. Based on these results, TEQ_BaP and MOE values were calculated for the positive samples. All three teas with detectable PAHs exhibited MOE values above 10,000, indicating a low level of potential carcinogenic risk. However, the presence of PAHs in certain tea types highlights the importance of ongoing monitoring, regulatory oversight, and risk communication to ensure consumer safety. Full article

Body size is one of the most important traits in the life history of vertebrates. In this work, we analyzed the morphometric traits of breeding males of the eastern Pacific green sea turtle population known as the black sea turtle on the coast of Michoacan, Mexico. The morphometric analysis indicates that males have the smallest body size compared to other males in other Chelonia populations. The size of male black sea turtles is even smaller (by 15.2 cm in average CCL) in carapace curve length (70.5 cm CCL) than females (85.7 CCL) of the same population. This suggests that males reach maturity at an earlier age than females and would have implications for mating success. The assessment of the operational sex ratio was conducted over a multi-year period (2004, 2009, 2017, and 2023). From a total of 336 h of observation, we identified 653 mating groups containing 1986 males and 669 females. The estimated operational sex ratio (OSR) during the study period was 2.96 males for every female. Among the mating groups, 34.3% consisted of only one male, while 65.7% included two or more males, with the number of males per female ranging from 2 to 17. The analysis revealed that there are interannual and monthly variations in OSR values, with observations showing a range from 2.3:1 (male to female) in 2023 to 4.3:1 (male to female) in 2009. The OSR variations show an evolving trend that can inform future strategies. In September, the ratio was 2.8:1, which changed to 3:1 in October and November, and then reached 3.3:1 in December (male/female). This gradual increase provides a clear opportunity to delve deeper into these dynamics and take proactive measures to address them positively. Full article

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) (FAW), is an invasive and destructive polyphagous pest that poses a significant threat to global agricultural production. The FAW mainly damages maize, with a particular preference for V3–V5 (third to fifth leaf collar) plant stages in northern China. How the FAW moth precisely locates maize plants in the V3–V5 stage at night remains unclear. The aims of this study were to evaluate the visual and olfactory cues used by the FAW to identify its host plant, maize, in order to select attractants with better trapping efficacy. Hyperspectral analysis of maize plants at different growth stages using the ASD Fieldspec 4 spectrometer was performed using mimics (moths or maize leaves sealed with transparent plastic sheets) and black cloth-covered plants for single visual and single olfactory attraction experiments. Gas chromatography–mass spectrometry (GC-MS) was used to analyze volatiles emitted from V3–V5 stage maize leaves. Volatile organic chemicals (VOCs) were screened using electroantennography (EAG) and Y-tube. Attractor efficacy was validated using mimics + VOCs. Results showed very little variance in the spectral reflectance curve of the maize at different growth stages. Fifteen VOCs were identified in the V3–V5 stage leaves of three different maize varieties, of which cis-3-hexenyl acetate and myrcene were found in relatively high concentrations in these maize varieties. The frequency of visits attracted by single visual stimuli was significantly lower than that attracted by single olfactory or olfactory + visual cues. The attractiveness of foliar cis-3-hexenyl acetate increased as its concentration decreased. The combination of mimics + cis-3-hexenyl acetate (1 ng/μL) increased host detection efficiency and stimulated mating behavior. These results indicate that the nocturnal insect FAW primarily uses olfactory cues for host identification, with visual cues serving as a complementary modality. The synergistic effect of olfactory and visual cues increases the efficiency of host recognition. We found that cis-3-hexenol acetate at a concentration from maize leaves is a reliable olfactory signal for the FAW. When using host plant VOCs as attractants to control adult FAWs, the role of visual cues must be considered. Full article

Pseudopregnancy (PPG) is a common reproductive disorder in dairy goats, characterized by the accumulation of sterile fluid in the uterus and persistence of a corpus luteum, leading to temporary infertility and reduced farm efficiency. This study aimed to determine the pregnancy-associated glycoprotein (PAG) profile in dairy goats and to evaluate the PAG/P4 ratio as a potential novel biomarker for PPG diagnosis. A total of 605 Saanen and crossbreed mated goats were evaluated via transabdominal ultrasonography between 31 and 52 days after the removal of bucks in four intensive dairy farms, presenting an overall PPG incidence of 7.8%. Blood samples from PPG (n = 47), nonpregnant (NPG; negative control; n = 11), and pregnant (PG; positive control; n = 10) does were collected for PAG and P4 analysis. The PAG plasma levels were 0.08 ± 0.02, 0.13 ± 0.04, and 1.45 ± 0.04 OD (optical density) in the PPG, NPG, and PG groups, respectively (p < 0.001). The PAG/P4 ratio was lower in the PPG group (0.01 ± 0.11; p < 0.001) than in the NPG (0.24 ± 0.23) and PG (0.18 ± 0.23) groups. This difference allows for the establishment of a new methodological diagnostic approach to PPG. The area under the curve (AUC) was 0.996 for a cut-off of 0.04 and 97.9% and 100% sensitivity and specificity, respectively. This study suggests that the PAG/P4 ratio can serve as a reliable biomarker for PPG diagnosis, helping to distinguish it from pregnancy and nonpregnancy and improving reproductive management in dairy goats. Full article

This study proposes a new wheel-leg mechanism concept and formulations for the kinematics and dynamics of a stair-climbing robot utilizing the rotating leg locomotion of curved spokes and rolling tires. The system consists of four motor-driven tires and four curved-spoke legs. The curved-spoke leg is semicircle-like and is used to climb stairs. Once the spoke leg rolls on the surface, it lifts and pulls the mating wheel toward the surface, owing to the kinematic constraint between the spoke and the wheel. Single-wheel climbing is a necessary condition for the stair climbing of whole robots equipped with front and rear axles. This study proposes the design requirements of a spoke leg for the success of single-wheel climbing in terms of kinematic inequality equations according to the scenario of single-wheel climbing. For a design configuration that enables single-wheel climbing, the required minimum friction coefficient for the static analysis of the stair-climbing wheeled robots is demon-strated. Thereafter, the stair-climbing ability is validated through the dynamic equations that enable the frictional slip of the tires, as well as the curved-spoke legs. Lastly, the results revealed that the rotating locomotion of the well-designed curved-spoke legs effectively enables the stair climbing of the whole robot. Full article

Revealing the relationship between the mating system (i.e., the outcrossing/inbreeding degree) and the fitness of seeds in tree species under wild conditions is essential for understanding the ecological adaptability and evolutionary stability of the species. This study collected open-pollinated seeds from seven wild populations of Pinus yunnanensis var. tenuifolia that exhibited fragmentation in the Nanpan–Hongshui River basin, an ecologically fragile area in China. The seeds and sprouts (germinated seeds) from 20 families were genotyped (24 seeds and 24 sprouts per family) using twelve microsatellite loci to reveal the genetic diversity, mating status, and effect of inbreeding on the three seed quality indicators (thousand-seed weight, germination rate, and germination potential). The three seed quality indicators differed significantly between families (p < 0.001). Higher values of genetic diversity (except the observed heterozygosity) were observed in the sprout group than those in the seed group. Families from different populations showed a notable genetic differentiation (Φst = 0.12), and a large part of families from the common populations had a high degree of coancestry, which signified that the current habitat fragmentation is limiting gene flow between populations. High levels of outcrossing rates (tm) were observed in both the seed group (t_m = 0.974) and the sprout group (t_m = 0.978), indicating that a low proportion of seeds were self-fertilized. Although there was a slightly higher single outcrossing rate (t_s = 0.888) and a lower proportion of biparental inbreeding (t_m − t_s = 0.077) in sprouts compared to the seeds (t_s = 0.871, t_m − t_s = 0.091), indicating that a part of inbred seeds were purged during the germination stage, curve fitting between the outcrossing rate and seed quality indicators showed that a certain degree of biparental inbreeding (t_s between 0.89 and 0.91 and t_m − t_s between 0.09 and 0.11) did have a positive effect on seed germination ability. This highlights that excessive inbreeding or outbreeding seems to be unfavorable to seed viability. The peculiar relationship between seed viability and the mating system in P. yunnanensis var. tenuifolia was likely an evolutionary consequence of a trade-off between the nature of mixed mating and its specific ecological niche. Full article

The effect of the microstructure of siliconized graphite on tribological properties is investigated by using a high-temperature and high-pressure water-lubricated tribometer on a self-mated ring-on-ring configuration under an applied load of 500–1500 N with a spindle speed of 100–5000 rpm in both 90 °C (5 MPa) and 25 °C (1 MPa) water environments, respectively. The Stribeck curves measurement and continuous wear tests are performed and analyzed in both water environments. The wear behaviors of the graphite, SiC, and free-silicon phases in siliconized graphite are demonstrated to explore the wear mechanism. The larger wear depths of a low-worn surface roughness on the three phases contribute to the boundary lubrication. The shallower wear depths are observed on the SiC and Si phases under the mixed lubrication, corresponding to partial contact wear of surface asperities. The wavy surface of the SiC phase and uniform flow-oriented striae of the Si phase are attributed to hydrodynamic lubrication, caused by full water film scouring the worn surface. Finally, an integrated evaluation method of G duty parameters is successfully used to identify the lubrication regimes of siliconized graphite from the boundary, mixed, to hydrodynamic lubrications for a water-lubricated thrust bearing application in the main coolant pump of a nuclear power plant. Full article

In warmer environments, most ectotherms exhibit a plastic reduction in body size (the temperature–size rule, TSR). However, in such environments, growth is usually accelerated and would be expected to result in maturation at a larger body size, leading to increases in fecundity, survival, and mating success, compared to maturation at a smaller size (the ‘life-history puzzle’). To explore these mechanisms, we reared Aldrichina grahami at 20 °C, 25 °C, and 30 °C, and added a nutritional challenge by using dilutions of pork liver paste to provide diets that ranged in quality from high (undiluted) to moderate (1/8), low (1/16), and poor (1/24). Larvae were randomly sampled for weighing from hatching. Growth curves were fitted to the relationships between growth rate and weight for the third instar larvae. Our results showed that body size was affected by an interaction between temperature and diet, and that following or not following the TSR can vary depending on underfeeding. Moreover, when the TSR was followed as temperature increased, there was a cross-over point that divided the two growth curves into early and later stages, which could be used to help understand the life-history puzzle in warmer temperatures, with the instantaneous growth rate being faster in the early stages of development and then slower in later stages. This study reminds us that animals have evolved to cope with multiple simultaneous environmental changes, and it has thus offered a better understanding of life-history puzzles. Full article

This paper presents an ultimate motion methodology of a face-milling spiral bevel gear pair to synthesize the mating tooth surfaces with a predesigned fourth-order motion curve. The methodology is to control some contact points along the contact path in the process of tooth contact analysis via application of an extended local synthesis which permits some transmission errors rather than zero at the concerned contact point. The modified offset motion correction is selected to demonstrate the proposed methodology. Applied torque corresponding to an elastic approach of 0.00635 mm at the mean contact point is calculated and the loaded tooth contact analysis is performed. Numerical results show that the extended local synthesis can effectively control the transmission errors on the predesigned fourth-order motion curve at arbitrarily predesigned contact points along the contact path of the spiral bevel gear pair. The tooth contact pattern for the actual tooth pair is scattered into three segments since the rotational motion of the driven gear at any instant angular position is dependent on the tooth pair with the least transmission error among the three adjacent tooth pairs. The actual tooth contact patterns of the spiral bevel gear pair become continuous when meshing tooth surfaces are elastically deformed. Full article

This paper presents the experimental results of a study investigating the impact of the machining fluid type, the variable factor, used in slide burnishing on 2D and 3D surface roughness; surface topography; Abbott–Firestone curve shape; microhardness; and SFE (surface free energy). In the experiment, pre-ground, ringed samples of C45 steel were used. The results showed an over eight-fold decrease in the value of the Ra (arithmetical mean deviation) parameter and over a five-fold decrease in the Rt (total height of profile) parameter in relation to their values after grinding. The parameters Rpk (reduced peak height), Rk (core roughness depth), and Rvk (reduced valley depth) were also reduced. The Abbott–Firestone curve after slide burnishing changed its angle of inclination (it was more flattened), and the material ratio Smr increased. The reduction in the Rpk and Rk parameters and increased material ratio will most likely contribute to restoring the functionality of these surfaces (increased resistance to abrasive wear). After slide burnishing, the maximum 25% increase in microhardness was obtained compared to the value after grinding, while the layer thickness was 20 μm. The surface energy of elements subjected to slide burnishing using various machining fluids slightly increased, or its value was close to that of the ground surface. The most favourable properties of the surface layer in terms of mating between two elements were obtained for a part that was slide-burnished with a mixture of oil + polymethyl methacrylate (PMM) + molybdenum disulphide (MoS₂). Full article

Beet webworms, Loxostege sticticalis L. (Lepidoptera: Pyralidae), are one of the most destructive pest insects in northern China, and their populations outbreak periodically. Developing an indicator that defines the ending and beginning of the occurrence period cycle is urgent for the population forecast and theoretical study. The sex ratio can be a primary pathway through which species regulate population size. We measured the maximum mating potential of both females and males and the population net reproductive rate under different sex ratios (e.g., 3:1, 2:1, 1:1, 1:2, 1:3). The maximum mating frequency of males was 2.91 times that of females. The progeny contribution per mating decreased with increased mating times in males. The variation in population net reproductive rate affected by the sex ratio fits the parabolic curve analysis and peaked at 1.82 for females vs. males. Our results illustrate the quantitative connection phenomenon shown by the historical data: population outbreaks occur at a sex ratio of two or more and collapse at a sex rate lower than one. Simultaneously, the sex ratio may be utilized as a definite indicator for the beginning and end of the future occurrence cycle in the beet webworm. Full article

In this study, we consider framed curves as regular or singular space curves with an adapted frame in Euclidean 3-space. We define framed natural mates of a framed curve that are tangent to the generalized principal normal of the framed curve. Subsequently, we present the relationships between a framed curve and its framed natural mates. In particular, we establish some necessary and sufficient conditions for the framed natural mates of specific framed curves, such as framed spherical curves, framed helices, framed slant helices, and framed rectifying curves. Finally, we support the concept with some examples. Full article