Loss Rate Research Articles

Intestinal Energy Harvest Mediates Gut Microbiota-Associated Weight Loss Following Bariatric Surgery.

Metabolic and bariatric surgery (MBS) is the most effective treatment for class III obesity. The capacity to efficiently extract intestinal energy is potentially a determinant of varying weight loss outcomes post-MBS. Prior research indicated that intestinal energy harvest is correlated with post-MBS weight loss. Studies have also demonstrated that the gut microbiota is associated with weight loss post-MBS. We aim to investigate whether gut microbiota-associated weight loss is mediated by intestinal energy harvest in patients post-MBS. We examined the relationship between specific gut microbiota, intestinal energy harvest, diet, and weight loss using fecal metagenomic sequence data, bomb calorimetry (fecal energy content as a proxy for calorie absorption), and a validated dietary questionnaire on 67 individuals before and after MBS. Mediation analysis and amachine learning algorithm were conducted. Intestinal energy harvest was a mediator in the relationship between theintestinal microbiota (Bacteroides caccae) and weight loss outcomes in patients post-MBS at 18months (M). The association between the abundance of B. caccae and post-MBS weight loss rate at 18M was partly mediated by 1M intestinal energy harvest (β = 0.001 ± 0.001, P = 0.020). This mediation represents 2.83% of the total effect (β = 0.050 ± 0.047; P = 0.028). Intestinal microbiota and energy harvest improved random forest model's accuracy in predicting weight loss results. Energy harvest partly mediates the relationship between the intestinal microbiota and weight loss outcomes among patients post-MBS. This study elucidates a potential mechanism regarding how intestinal energy absorption facilitates the effect of intestinal microbiota on energy metabolism and weight loss outcomes.

Design and Experiments of a Roll-Knife Pickup for a Buckwheat Pickup Harvester

To reduce grain loss during pickup and prevent stalk entanglement in buckwheat harvesters, thereby improving the quality of mechanized harvesting, a three-stage pickup conveyor roll with a ground-level rotary knife-type pickup header was designed and tested. This paper, based on the growth characteristics of buckwheat, determined the three-stage pickup conveying process and the overall structure of the ground-level rotary knife-type pickup header. Kinematic analysis and parameter design of the rotary knife-type pickup roll were conducted. Finally, a physical prototype was fabricated, and field performance tests were carried out, using machine forward speed and pickup roll rotational speed as influencing factors and pickup loss rate as an evaluation metric. Results showed that the interaction between pickup roll rotational speed and forward speed had a significant effect on the pickup loss rate, with forward speed having a greater impact than pickup roll rotational speed. Under consideration of their interaction, when the pickup roll rotational speed was within the range of 396–457 r/min, and the forward speed was between 0.9–1.0 m/s, the pickup loss rate was minimized. Based on the regression equation model, the predicted optimal conditions were a forward speed of 1.0 m/s and a roll pickup speed of 396 rpm. Under these conditions, the test results showed a pickup loss rate of 5.235%, indicating good pickup performance. This research provides a reference for the design of pickup devices in grain combine harvesters.

An experimental and theoretical study on the creep behavior of silt soil in the Yellow River flood area of Zhengzhou City

We took the silt soil in the Yellow River flood area of Zhengzhou City as the research object and carried out triaxial shear and triaxial creep tests on silt soil with different moisture contents (8%, 10%, 12%, 14%) to analyze the effect of moisture content on silt soil. In addition, the influence of moisture contents on soil creep characteristics and long-term strength was analyzed. Based on the fractional derivative theory, we established a fractional derivative model that can effectively describe the creep characteristics of silt soil in all stages, and used the Levenberg–Marquardt algorithm to inversely identify the relevant parameters of the fractional derivative creep model. The results show that the shear strengths of silt soil samples with moisture contents of 8%, 10%, 12% and 14% are 294 kPa, 236 kPa, 179 kPa and 161 kPa, respectively. The shear strength of silt soil decreases with increasing moisture content. When the moisture content increases, the cohesion of the silt soil decreases. Under the same deviatoric stress, the higher the moisture content of the silt soil, the greater the deformation will be. The long-term strength of silt soil decreases exponentially with the increase of moisture content. If the moisture content is 12%, the long-term strength loss rate of silt soil is the smallest, with a value of 32.96%. The calculated values of our creep model based on fractional derivatives have a high goodness of fit with the experimental results. This indicates that our model can better simulate the creep characteristics of silt soil. This study can provide a theoretical basis for engineering construction and geological disaster prevention in silt soil areas in the Yellow River flood area.

The GAPS Programme at TNG. LIX. Characterisation study of the ~300 Myr-old multi-planetary system orbiting the star BD+40 2790 (TOI-2076)

The long-term Global Architecture of Planetary Systems (GAPS) programme has been characterising a sample of young systems with transiting planets via spectroscopic and photometric follow-up observations. One of the main goals of GAPS is measuring planets' dynamical masses and bulk densities to help build a picture of how planets evolve in the early stages of their formation via a comparison between the fundamental physical properties of young and mature exoplanets. We collected more than 300 high-resolution spectra of the sim 300 Myr old star BD+40 2790 (TOI-2076) over about three years. This star hosts three transiting planets discovered by TESS, with orbital periods of sim 10, 21, and 35 days. From our determined fundamental planetary physical properties, we investigate the temporal evolution of the planetary atmospheres by calculating the expected mass loss rate due to photo-evaporation up to a system age of 5 Gyr. BD+40 2790 shows an activity-induced scatter larger than 30 ms in the radial velocities. We employed different methods to measure the stellar radial velocities, along with several models to filter out the dominant stellar activity signal to bring to light the planet-induced signals, which are expected to have semi-amplitudes that are lower by one order of magnitude. We evaluated the mass loss rate of the planetary atmospheres using photo-ionisation hydrodynamic modeling, accounting for the temporal evolution of the stellar high-energy flux through the adoption of different models for X-rays and EUV irradiation. The dynamical analysis confirms that the three sub-Neptune-sized companions (with our radius measurements of $R_b$=2.54pm 0.04, $R_c$=3.35pm 0.05, and $R_d$=3.29pm 0.06 have masses that situate them in the planetary regime. We derived 3sigma upper limits below or close to the mass of Neptune for all the planets in our sample: 11--12, 12--13.5, and 14--19 for planets $b$, $c$, and $d$, respectively. In the case of planet $d$, we found promising clues that the mass could be between sim 7 and 8 with a significance level between 2.3--2.5sigma (at best). This result must be further investigated using other analysis methods and techniques or using high-precision near-infrared (nIR) spectrographs to collect new radial velocities, which could be less affected by stellar activity. Atmospheric photo-evaporation simulations predict that BD+40 2790\,b is currently losing its H-He gaseous envelope and that it will be completely lost at an age within 0.5--3\,Gyr if its current mass is lower than 12\,M$_ Furthermore, BD+40 2790\,c could have a lower bulk density than $b$ and might be able to retain its atmosphere up to an age of 5 Gyr. For the outermost object, planet $d$, we predicted an almost negligible evolution of its mass and radius, induced by photo-evaporation.

Using USLE, GIS and remote sensing for the soil loss assessment in the National Park of Theniet El Had, Algeria

Soil water erosion is one of the problems that affect the environment, agriculture and social life by threatening several land surfaces. The objective of this study is to use the USLE model, GIS and remote sensing (RS) to estimate the annual rate of soil loss by water erosion in the Theniet El Had National Park (THNP) which belongs to the mountainous ecosystem of Djebel El Meddad, located in the northwest of Algeria. The use of the USLE model takes into account the five factors controlling water erosion, namely: the rain erosivity (R) determined from the annual rainfall data, the soil erodibility (K) developed from soil survey data, the slope lengths (LS) generated by using DEM, the vegetation cover (C) by the use of RS data and erosion control management practices (P) by field trips. The integration of these factors made it possible to establish the quantitative map of the annual rate of soil loss varying between 0.02 and 55.10 (t/ha.year), with an average of around 6.64 (t/ha.year). Five erosion aggressiveness classes are used; very weak, weak, moderate, strong and very strong which represent a rate respectively of 23.70, 44.65, 22.72, 4.41 and 4.52 % of the study area surface. The areas with high and very high erosion rates are located in the north having a very rugged relief and low vegetation cover. This study can be used in the mountainous ecosystems and it will make it possible to set up priority intervention zones to combat the risk of water erosion.

Research on the aging mechanism of polypropylene nonwoven geotextiles under simulated heavy metal aging scenarios

We conducted accelerated aging experiments on two types of polypropylene (PP) nonwoven geotextiles (filament geotextile and staple fiber geotextile), immersing them in five different simulated liquids at temperatures of 25 °C, 55 °C, and 85 °C for 200 days. At 85 °C and a pH of 1, the tensile strength and elongation at break of PP filament materials decreased by 95% and 86%, respectively. The presence of heavy metals(arsenic and cadmium), speeds up the aging process in both types of PP geotextiles. Under identical conditions, these heavy metals can increase the loss of tensile strength in geotextiles by more than 7% in 200 days. Increases in temperature, acidic environment, and heavy metal concentration all contribute to faster aging of these geotextiles. Although filament geotextiles exhibit higher tensile strength and elongation at break, staple fiber geotextiles show a lower rate of tensile strength loss during aging and better maintain their tensile strength in high-temperature acidic conditions. During the aging process, cross-linking and recrystallization occur, both of which control the aging rate and the formation of microplastics.

Carbon Dots-Mediated Photodynamic Treatment Reduces Postharvest Senescence and Decay of Grapes by Regulating the Antioxidant System.

Grapes are susceptible to mold and decay during postharvest storage, and developing new technologies to extend their storage period has important application value. Photodynamic technology (PDT) in concurrence with carbon dots (CDs) proposes an innovative and eco-friendly preservation strategy. We examined the effects of carbon dots combined with photodynamic treatment on postharvest senescence and antioxidant system of table grape. The compounding of photodynamic technology with a 0.06 g L-1 CDs solution could possibly extend the postharvest storage period of grape berries. Through this strategy, we achieved a decreased rate of fruit rotting and weight loss alongside the delayed deterioration of fruit firmness, soluble solids, and titratable acid. As paired with photodynamic technology, CDs considerably decreased the postharvest storage loss of phenols, flavonoids, and reducing sugars as compared to the control group. Concurrently, it remarkably postponed the build-up of hydrogen peroxide (H2O2), superoxide anion (O2∙-), and malondialdehyde (MDA); elevated the levels of reduced ascorbic acid (AsA) and reduced glutathione (GSH); lowered the levels of dehydroascorbic acid (DHA) and oxidized glutathione (GSSG); raised the ratios of AsA/DHA and GSSH/GSSG; encouraged the activities of superoxide dismutase (SOD) and phenylalanine ammonia-lyase (PAL); and inhibited the activities of polyphenol oxidase (PPO) and lipoxygenase (LOX). Furthermore, it enhanced the iron reduction antioxidant capacity (FRAP) and DPPH radical scavenging capacity of grape berries. CDs combined with photodynamic treatment could efficiently lessen postharvest senescence and decay of grape berry while extending the storage time.

Association of Patient and Geographic Variables in Pediatric Patients With Prediabetes Becoming Lost to Follow-up.

Prediabetes (PD) is becoming more common, and management is complicated by high rates of loss to follow-up. We evaluated variables associated with lost to follow-up status for pediatric patients with PD referred to endocrinology for evaluation and management. We evaluated new patients referred to Children's of Alabama Endocrinology for PD from March 2017 through March 2021. Variables included patient medical and demographics as well as county-level metrics. Comparisons of patients who returned to clinic and those who were lost to follow-up were assessed by chi-square for categorical variables and Student's t-test/Wilcoxon rank sum test for continuous normal/skewed variables, respectively. Univariate logistic regression modeling identified risk factors for coming lost to follow-up and odds ratios with 95% confidence intervals were reported with a 2-sided P-value for significance of <.05. A total of 524 patients were included in the analysis. Almost one-fourth of patients were lost to follow-up (24.6%). The odds of returning to clinic were higher in patients with the Children's Health Insurance Plan, who were prescribed endocrine medications, who had a concurrent diagnosis of cholesterol disorder, who had referral to the endocrine clinic before COVID-19, and who were offered a telehealth visit. No other assessed variable was significantly associated with the likelihood of returning to clinic. Independent of obesity severity, age, sex, race, county-level health, and economic variables, the factor most strongly associated with returning to clinic was having a telemedicine visit scheduled. Our data suggest that offering telemedicine visits may reduce lost to follow-up rates in this patient population.

Mechanical properties and damage modeling of hybrid fiber reinforced concrete under freeze-thaw cycles

This study aimed to investigate the mechanical properties of steel-polyacrylonitrile hybrid fiber reinforced concrete and its durability under freeze-thaw damage. Firstly, the mechanical properties of hybrid fiber reinforced concrete were studied by compressive strength and flexural strength tests. Secondly, with the help of rapid freeze-thaw test, the variation rules of mass loss rate and relative dynamic elastic modulus were characterized. Based on the test results and freeze-thaw damage theory, the evolution equation of freeze-thaw damage of hybrid fiber reinforced concrete based on Weibull distribution was established. The results show that the enhancement effect of hybrid fiber on the mechanical strength of concrete is better than that of single mixed fiber, especially in the improvement of flexural strength; Accordingly, compared with the single mixing of steel fibers or single mixing of polyacrylonitrile fibers, hybrid fibers are more effective in improving the durability of concrete against freezing and this improvement effect increases with the increase of steel fiber content; The freeze-thaw damage model of Weibull distribution can better reflect the freeze-thaw damage process of hybrid fiber reinforced concrete .Through the freeze-thaw damage evolution curve, it can be found that after 500 freeze-thaw cycles, the freeze-thaw damage degree of the hybrid fiber reinforced concrete with different steel fiber content has been very close, which means that the influence of steel fiber content on the freeze-resistant performance of hybrid fiber reinforced concrete will be limited. This study provides a theoretical basis and technical basis for the design of concrete structures in alpine regions.

Preparation of biodegradable poly(lactic acid)/poly[(butylene diglycolate)‐co‐furandicarboxylate] blends with excellent toughness and gas barrier performance

AbstractPoly(lactic acid) (PLA) is known as one of the most promising biodegradable polyesters, while inherent brittleness and insufficient gas barrier performance limit its potential application as a film material. Herein, poly[(butylene diglycolate)‐co‐furandicarboxylate] (PBDF) with excellent flexibility and good gas barrier properties was synthesized and then melt‐blended with PLA. Compared with neat PLA, the elongation at break of the PLA/PBDF20 blend increased more than 40 times and reached over 176.7%. In addition, its O2, CO2 and H2O permeability coefficients decreased by 21.3%, 50.8% and 46.3%, respectively. Moreover, the PLA/PBDF20 blend also exhibited better biodegradability, with a weight loss rate increasing from 2.7% of neat PLA to 19.0% after 5 weeks of composting. Notably, incorporation of a multifunctional epoxy compatibilizer (Joncryl ADR®‐4368) into the PLA/PBDF blends further enhanced their toughness and gas barrier performance, which could be attributed to the improvement of the miscibility between PLA and PBDF. © 2024 Society of Chemical Industry.

Comparative Evaluation of Hearing and Salivary Flow Rate in Smokers and Non-smokers: A Cross-Sectional Study.

Background Smoking is a major global health issue that is linked to varioushealth conditions, including hearing loss and reduced salivary flow. This study aims to explore the relationship between smoking, hearing loss, and salivary flow rate. Methods This cross-sectional study was conducted over two months at a tertiary healthcare institute in Central India, involving 100 participants (50 smokers and 50 non-smokers) aged 18-55 years. Hearing status was assessed using audiometry, and the salivary flow rate was measured. Statistical analyses were performed using SPSS version 21 (IBM Corp., Armonk, NY, US). Results Smokers had a significantly higher prevalence of hearing loss (40%) compared to non-smokers (10%). The salivary flow rate was significantly lower in smokers (mean 0.5540 ml/min) than in non-smokers (mean 0.9240 ml/min). However, no significant correlation was found between the duration and frequency of smoking with hearing loss or salivary flow rate. Conclusion Smoking significantly impacts both hearing and salivary flow rate, hence smokers show a higher risk of hearing loss and reduced salivary flow rate. Early hearing screenings and preventive measures are recommended for smokers. Further research with larger sample sizes is needed to explore the long-term effects of smoking on these health parameters.

块茎收获物清选机的设计与模拟分析

In this paper, a screening machine was designed to remove the impurities in the tuber harvest, which integrates the functions of vibration screening, air separation, and flexible polishing. Discrete element simulation analysis was carried out to investigate the movement of tuber harvest and soil in the machine and the effect of polishing and removing impurities, the rationality of the structure, and the size were verified. Orthogonal tests were designed and carried out, with the rate of impurity, loss, and crushing as indicators and crank speed, impeller speed, and polishing roller speed as factors. The optimum working parameters were obtained: crank speed 280.12 r/min, impeller speed 1056.27 r/min, polishing roller speed 405.02 r/min, the impurity content was 0.29%, the loss rate was 1.01%, and the breakage rate was 0.11%. Through experimental verification, the actual value and theoretical value are basically the same, which verifies the rationality.

Spring-Finger Motion Law Analysis and Cam Slide Optimal Design of Spring-Finger Cylinder Peanut Pickup Mechanism

Two-stage harvesting is the main method used for the mechanized harvesting of peanuts in China, in which the pickup device is a core part of the combine harvester. In order to solve the problem of pod loss caused by “stack” and “loss picking” from peanut plants when using a traditional spring-finger cylinder pickup device, an optimal spring-finger cylinder peanut pickup mechanism was designed and its picking properties were tested. Based on the picking characteristics and picking force analysis when considering a peanut plant windrow, the ideal picking attitude and swing rule of the spring-finger were determined, and the cam slide, as the core element of the spring-finger cylinder peanut pickup device, was optimized. A mathematical model of the cam cylinder center line was established according to the swing law of the four picking stations utilizing the spring-finger. MATLAB and ADAMS were used to establish a simulation of the pickup mechanism, and kinematics and dynamics simulation analyses of the pickup mechanism were carried out. According to the design results, a prototype was constructed and a running pickup test was carried out. The peanut plant picking experiments indicated that the phenomenon of peanut plant stacking had significantly disappeared. Furthermore, through response surface analysis, the optimal working parameters of the picking device were obtained as follows: the forward speed Vm was 48.0 m/min, the rotational speed N was 50 r/min, and the ground height H was −16.8 mm. The picking rate of peanut plants was 99.21% and the pod loss rate was 1.79% under two harvesting conditions, with a peanut plant moisture content of 15% to 17%. This study provides technical support for the future design of picking devices for two-stage peanut pickup harvesters.

The Design and Experimentation of a Wheeled-Chassis Potato Combine Harvester with Integrated Bagging and Ton Bag-Lifting Systems

The mechanized harvesting level of potatoes in the arid areas of Northwest China is low and mainly relies on simple machinery to dig the soil surface, and then people manually pick up and bag the potatoes. This harvesting method has the problems of a high labor intensity, low operation efficiency, and high labor cost. Based on this, a wheeled-chassis potato combine harvester with integrated bagging and ton bag-lifting systems was developed, which could complete potato digging, potato–soil separation, potato–film separation, automatic bagging, and field ton bag lifting in one go. Firstly, based on the agronomic requirements and unique terrain characteristics of potato planting in this area, the structural design of the whole machine was completed with SOLIDORKS 2019 3D software. Secondly, the dynamic model was established for a numerical analysis, and the core parameters of key components were determined. The field experiments showed that the potato loss rate was 2.1%, the potato damage rate was 1.7%, the skin breaking rate was 2.5%, the impurity content was 1.9%, and the productivity was 0.15~0.23 hm2/h. The above field test indexes met the requirements of national and industrial standards.

曲柄摇杆式深施机构的设计与施肥性能试验研究

In response to the poor fertilization performance of the deep application mechanism of the deep application liquid fertilizer applicator under multiple parameters, the fertilization variation of the crank rocker deep application mechanism under multiple working parameters is explored. To obtain the fertilization variation of the crank rocker deep application mechanism, a fertilization performance test bench for the crank rocker deep application mechanism is developed. On this test bench, the crank speed, liquid pump pressure, and spray hole diameter are used as experimental factors, and fertilizer application rate is used as experimental indicators. A composite design scheme of rotation center is adopted to establish a relationship model and response surface diagram between experimental influencing factors and influencing indicators. Design Expert 8.0.10 software is used to analyze and optimize the experimental data. The optimal results are a crank speed of 145.80 r/min, a liquid pump pressure of 0.25 MPa, a spray hole diameter of 3.02 mm, a fertilizer application rate of 28.6 mL, and a fertilizer loss rate of 1.9%. At this time, the fertilization performance of the mechanism is optimal. This parameter combination is applied for testing and verification to verify its rationality. The results can ensure that the crank rocker deep application mechanism has good working performance when working under multiple parameters, providing theoretical reference for designing deep application liquid fertilizer machines with simple structure and optimal fertilization performance.

Soil moisture evidence of self-restoration in coal mining subsidence area of Shendong Mining area: Cognition based on stable isotopes

The Shendong mining area is the largest coal production base in China. However, the area is dry and water scarce, and the ecological environment is fragile. Large scale mining of shallow and thick coal seam in mining area may affect surface moisture and threaten surface ecological security. In order to understand the change of soil moisture in subsidence area. The evaporation loss rate of undisturbed and subsidence soil in mining area was estimated by using water stable isotope technique. The soil particle size and moisture of undisturbed and subsidence soil were compared. The results showed that the soil particle size did not change significantly in the subsidence area, but the continuity of soil structure changed. The evaporation loss rate of soil in subsidence area is about 15 % lower than that of undisturbed soil, and the soil moisture of soil in subsidence area is about 10 % higher than that of undisturbed soil. Further, the Craig-Gordon model is more accurate than the Rayleigh model in estimating the evaporation loss of soil moisture. Our work showed that the soil structure of coal mining subsidence area becomes much looser and the loose cover formed by the surface soil is the main reason for the reduction of soil moisture evaporation. The significant increase of soil moisture will be beneficial to plant recovery and growth, and lay a water foundation for ecological self-restoration in subsidence area. This study is helpful to understand the influence of coal mining subsidence on soil and surface hydrology in arid and semi-arid areas, and has important significance for optimizing and improving the ecological reclamation model of mining areas in western China.

Obstetric outcomes of transabdominal cerclage: A retrospective observational study in Japan.

This study aimed to investigate the obstetric outcomes of transabdominal cerclage (TAC) in Japan. Questionnaires on TAC were sent to 183 institutions performing high-quality perinatal management in Japan. As a first-step questionnaire, we asked whether TAC was performed between January 1, 2011, and December 31, 2022. In the second step of the questionnaire, the characteristics of all cases were asked from all institutions in which TAC was performed. The response rate for the first survey was 59% (108/183). Of the 108 institutions, 27 performed TAC (25%) in 133 pregnancies. Of these 27 institutions, 19 responded to the second survey. One hundred twenty-five pregnancies were included in this study, five of which were aborted (gestational weeks <22 weeks), and 69 babies were born after 37 gestational weeks (55%). Eighty-two open abdominal cerclages were performed at 17 institutions and 43 laparoscopic TACs at three institutions. There were no differences in the age at TAC, gestational weeks at TAC, operative time of TAC, gestational weeks at delivery, incidence rate of second-trimester loss, or preterm delivery (before 37 gestational weeks) rate between the two groups. However, blood loss during open TAC was greater than that during laparoscopic TAC. TAC is a rare surgery for cervical insufficiency in Japan. TAC may be a safe and useful method for preventing second-trimester loss and preterm delivery in high-risk patients. TAC may also be a key option in Japan to improve perinatal outcomes in patients with cervical insufficiency.

Foliar application of nutrient formulation enhances the post-harvest quality of tuberose (Agave amica Medik.) cv. Arka Prajwal

A study was conducted at the Department of Floriculture and Landscape Architecture Laboratory to investigate the influence of various nutrient formulations on the post-harvest quality of tuberose using a knapsack sprayer and drone. The treatments involved spraying macro and micronutrients along with growth regulators at different concentrations. Throughout the experiment, all parameters were recorded at 2 days intervals. Drone spray of MN mixture + 0.5 % poly feed + 0.6 % humic acid + 150 ppm GA3 recorded the maximum plant post-harvest quality attributes over other treatments. It showed increased post-harvest quality attributes, including relative water content percentage of flower (95.15 %), physiological loss of weight percentage of flower (14.83 %), shelf life at room temperature (3.79 days) and vase life (12.45 days). Additionally, the treatment was found to be the best for parameters of water uptake (38.45 g) and percentage of floret opened (27.02). Plots treated with drone spray of MN mixture + 0.5 % poly feed + 0.6 % humic acid + GA3 at 150 ppm showed a reduced rate of transpiration loss of water (14.89 g) and electrolyte leakage (12.52). The experimental findings demonstrated that foliar application of nutrients along with growth regulators at different concentrations using drones improved the post-harvest quality of tuberose.

Risk factors analysis and prediction model construction of major adverse cardiovascular events in pregnant women with valvular heart disease

Objective: To analysis the risk factors for major adverse cardiovascular event (MACE) in pregnant women with valvular heart disease (VHD) and to construct a risk prediction model. Methods: The clinical data of 245 pregnant women with VHD who were hospitalized in Beijing Anzhen Hospital from January 1, 2012, to June 1, 2023 were retrospectively analyzed, including general information, pre-pregnancy and pregnancy-associated cardiac conditions, and MACE. Univariate analysis and logistic regression models were employed to identify risk factors for MACE during pregnancy among pregnant women with VHD. Furthermore, a predictive model was constructed and internal validation was conducted using bootstrap techniques. Results: (1) Among 245 pregnant women with VHD, the incidence of MACE was 18.0% (44/245), and the most common MACE was heart failure (61.4%, 27/44). The mitral valve was the most frequently affected valve (64.9%, 159/245). Prior to pregnancy, the most common type of valve surgery undertaken was mechanical valve replacement, representing 31.4% (77/245) of surgeries. In contrast, among those pregnant women who did not undergo valve surgery before pregnancy, the most common lesion type was mitral regurgitation (17.6%, 43/245). (2) Comparing the maternal and infant outcomes of warfarin, low molecular weight heparin (LMWH) and LMWH sequential with warfarin, the fetal loss rate (36%, 15/42) and malformation rate (7%, 3/42) were the highest, but the MACE rate (12%, 5/42) was the lowest in warfarin group. The fetal loss rate (1/19), malformation rate (1/19) and artificial valve thrombosis rate (0) of LMWH sequential with warfarin were the lowest, and the fetal loss rate and artificial valve thrombosis rate of the three anticoagulation methods were statistically significant (all P<0.05). (3) There were no significant differences in gestational age, age of diagnosis of heart disease, weight at delivery, pre-pregnancy body mass index, proportion of multiparous women and chronic medical history between women with MACE and those without MACE (all P>0.05). (4) Binary logistic regression analysis identified the following as risk factors for MACE during the second trimester of pregnancy among pregnant women with VHD: pre-pregnancy cardiac symptoms, history of corrective surgery for congenital heart disease, pregnancy risk grade Ⅴ, anticoagulation with LMWH during pregnancy, and arrhythmia (all P<0.05). Based on the results of multivariate analysis, a receiver operating characteristic curve was constructed, with an area under the curve of 0.837, indicating good discriminative ability. The calibration plot demonstrated a close alignment between the standard curve and the calibration prediction curve, suggesting excellent calibration of the model. Conclusions: Pregnant women with VHD are at a high risk of experiencing MACE during gestation. Five risk factors, including pre-pregnancy cardiac symptoms, history of corrective surgery for congenital heart disease, pregnancy risk grade Ⅴ, anticoagulation with LMWH, and arrhythmia, could aid in identifying high-risk pregnant women.

Green synthesis of Bio-CuS quantum dots by sulfate reducing bacteria for solid-phase photocatalytic degradation of polyethylene film

In this study, CuS quantum dots (QDs) synthesized through biological method were used as photocatalysts for the photocatalytic degradation of polyethylene (PE) plastics. Bio-CuS QDs were synthesized through a green process using sulfate reducing bacteria, while Che-CuS QDs were prepared by chemical precipitation for comparison. The crystal structure, surface morphology, microstructure and optical properties of the samples were detected by XRD, SEM, TEM and UV–Vis DRS. The green synthesis mechanism of Bio-CuS was inferred by analyzing changes in amino acid concentration and the three-dimensional fluorescence spectra of extracellular polymeric substances before and after synthesis. The photocatalytic degradation of PE films by Che-CuS and Bio-CuS was investigated. The weight loss rates of PE+Che-CuS and PE+Bio-CuS were 9.1 % and 12.8 % after 14 d irradiation, respectively, while pure PE was only 1.7 %. Furthermore, SEM, UV–Vis DRS, contact angle, TGA, GPC and FTIR were adopted to characterize the PE film. The results revealed that PE+Che-CuS and PE+Bio-CuS underwent major changes in morphology, transparency, hydrophilicity, thermal stability, molecular weight and functional groups compared with PE, with more pronounced changes observed for PE+Bio-CuS. The quenching experiments of active species showed that h+ and·OH were critical to the PE degradation. The intermediate products of PE degradation were analyzed by GC–MS, and a possible degradation pathway was proposed. In addition, the possible mechanism of photocatalytic degradation of PE films by CuS QDs was proposed. This work provides a green remediation approach to addressing the growing plastic pollution in the environment.