Research on the Correction Algorithm for Ozone Inversion in Differential Absorption Lidar

Due to the complex and variable nature of the atmospheric conditions, traditional multi-wavelength differential absorption lidar (DIAL) methods often suffer from significant errors when inverting ozone concentrations. As the detection range increases, there is a higher demand for Signal to Noise Ratio (SNR) in lidar signals. Based on this, the paper discusses the impact of different atmospheric factors on the accuracy of ozone concentration inversion. It also compares the advantages and disadvantages of the two-wavelength differential method and the three-wavelength dual-differential method under both noisy and noise-free conditions. Firstly, the errors caused by air molecular extinction, aerosol extinction, and backscatter terms in the inversion using the two-wavelength differential method were simulated. Secondly, the corrected inversion errors were obtained through direct correction and the introduction of a three-wavelength dual differential correction. Finally, addressing the issue of insufficient SNR in practical inversions, the inversion errors of the two correction methods were simulated by constructing lidar parameters and incorporating appropriate noise. The results indicate that the traditional two-wavelength differential algorithm is significantly affected by aerosols, making it more sensitive to aerosol concentration and structural changes. On the other hand, the three-wavelength dual differential algorithm requires a higher SNR in lidar signals. Therefore, we propose a novel strategy for inverting atmospheric ozone concentration, which prioritizes the use of the three-wavelength dual-differential method in regions with high SNR and high aerosol concentration. Conversely, the direct correction method utilizing the two-wavelength differential approach is used. This approach holds the potential for high-precision ozone concentration profile inversion under different atmospheric conditions

Vitamin B12 status and folic acid/vitamin B12 related to the risk of gestational diabetes mellitus in pregnancy: a systematic review and meta-analysis of observational studies

Abstract Background This review was conducted to investigate the association between serum vitamin B12 levels as well as folic acid/vitamin B12 during pregnancy and the risk of gestational diabetes mellitus (GDM). Methods A comprehensive search of electronic databases (Embase, PubMed, and Web of Science) was performed. The odds ratios (ORs) with 95% confidence intervals (CIs) of GDM risk were summarized using a random effects model. We also performed subgroup analyses to explore the source of heterogeneity. Results A total of 10 studies, including 10,595 pregnant women were assessed. Women with vitamin B12 deficiency were at higher risk for developing GDM when compared with those who were vitamin B12 sufficient (OR, 1.46; 95% CI 1.21–1.79; I2: 59.0%). Subgroup analysis indicated that this association might differ based on sample size and geographical distribution. Elevated vitamin B12 levels may decrease the risk of GDM by 23%. The role of excess folic acid and low vitamin B12 levels in the occurrence of GDM is also controversial. Conclusion In summary, vitamin B12 deficiency is associated with increased risk of GDM, it is necessary to pay more attention to the balance of vitamin B12 and folic acid. However, more in-depth studies across multiple populations are needed to verify these results

Research on the Performance of an Active Rotating Tropospheric and Stratospheric Doppler Wind Lidar Transmitter and Receiver

This paper investigates the transmitter and receiver performance of an active rotating tropospheric stratospheric Doppler wind Lidar. A 532 nm laser was determined as the detection wavelength based on transmission and scattering aspects. A ten-fold Galileo beam expander consisting of spherical and aspherical mirrors was designed and produced to compress the outgoing laser’s divergence angle using ZEMAX simulation optimization and optical-mechanical mounting means. The structure and support of the 800 mm Cassegrain telescope was redesigned. Additionally, the structure of the receiver was optimized, and the size was reduced. Meanwhile, the detectors and fiber mountings were changed to improve the stability of the received optical path. A single-channel atmospheric echo signal test was used to select the best-performing photomultiplier tube (PMT). Finally, the atmospheric wind field detection results of the original and upgraded systems were compared. The results show that after optimizing the transmitter and receiver, the detection altitude of the system is increased to about 47 km, and the wind speed and wind direction profiles match better with radiosonde measurements

Performance Evaluation and Error Tracing of Rotary Rayleigh Doppler Wind LiDAR

In the study of atmospheric wind fields from the upper troposphere to the stratosphere (10 km to 50 km), direct detection wind LiDAR is considered a promising method that offers high-precision atmospheric wind field data. In 2020, Xie et al. of the Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, developed an innovative rotating Rayleigh Doppler wind LiDAR (RRDWL). The system aims to achieve single-LiDAR detection of atmospheric wind fields by rotating the entire device cabin. In 2022, the feasibility of the system was successfully validated in laboratory conditions, and field deployment was completed. Due to the structural differences between this system and traditional direct-detection wind LiDAR, performance tests were conducted to evaluate its continuous detection capability in outdoor environments. Subsequently, based on the test results and error analysis, further analysis was carried out to identify the main factors affecting the system’s detection performance. Finally, the error analysis and traceability of the detection results were conducted, and corresponding measures were discussed to provide a theoretical foundation for optimizing the performance of RRDWL

The application of measuring atmospheric properties in overlap factor region using scanning Lidar

This paper explores the effects of different factors on the results and accuracy of aerosol optical property measurements made in overlap factor regions using scanning lidar, simulation calculations and aerosol detection experiments. First, the measurement principle was analysed using the atmospheric layered structure model. The slope inversion of the simulated backscattering coefficient of the aerosols was performed using the Fernald method. Second, the measurement errors caused by the inhomogeneity of the horizontal atmospheric layers and scanning angle errors were analysed for different weather conditions. Finally, the aerosol detection accuracies of the scanning lidar under different weather conditions were explored by employing comparative experiments. The experimental results showed that the aerosol extinction characteristics in the overlap factor region can be effectively obtained using the proposed method and that the measurement results were affected by the systematic errors in the scanning angle. The proposed method would effectively solve the problems caused by the unavailability of optical properties of aerosols in the overlap factor region of lidar. Moreover, the signal inversion of slant detection also provides an accurate theoretical basis for field experiments and has a good aerosol detection capability and potential application prospects

Simulation of Compact Spaceborne Lidar with High-Repetition-Rate Laser for Cloud and Aerosol Detection under Different Atmospheric Conditions

To provide references for the design of the lab’s upcoming prototype of the compact spaceborne lidar with a high-repetition-rate laser (CSLHRL), in this paper, the detection signal of spaceborne lidar was simulated by the measured signal of ground-based lidar, and then, the detection capability of spaceborne lidar under different atmospheric conditions was evaluated by means of the signal-to-noise ratio (SNR), volume depolarization ratio (VDR) and attenuated color ratio (ACR). Firstly, the Fernald method was used to invert the optical parameters of cloud and aerosol with the measured signal of ground-based lidar. Secondly, the effective signal of the spaceborne lidar was simulated according to the known atmospheric optical parameters and the parameters of the spaceborne lidar system. Finally, by changing the cumulative laser pulse number and atmospheric conditions, a simulation was carried out to further evaluate the detection performance of the spaceborne lidar, and some suggestions for the development of the system are given. The experimental results showed that the cloud layer and aerosol layer with an extinction coefficient above 0.3 km−1 could be easily obtained when the laser cumulative pulse number was 1000 and the vertical resolution was 15 m at night; the identification of moderate pollution aerosols and thick clouds could be easily identified in the daytime when the laser cumulative pulse number was 10,000 and the vertical resolution was 120 m

Characterization of Serum MicroRNAs Profile of PCOS and Identification of Novel Non-Invasive Biomarkers

Background: Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women of reproductive age, is characterized by polycystic ovaries, chronic anovulation, hyperandrogenism and insulin resistance. Despite the high prevalence of hyperandrogenemia, a definitive endocrine marker for PCOS has so far not been identified. Circulating miRNAs have recently been shown to serve as diagnostic/prognostic biomarkers in patients with cancers. Our current study focused on the altered expression of serum miRNAs and their correlation with PCOS. Method and Results: We systematically used the TaqMan Low Density Array followed by individual quantitative reverse transcription polymerase chain reaction assays to identify and validate the expression of serum miRNAs of PCOS patients. The expression levels of three miRNAs (miR-222, miR-146a and miR-30c) were significantly increased in PCOS patients with respect to the controls in our discovery evaluation and followed validation. The area under the receiver operating characteristic (ROC) curve (AUC) is 0.799, 0.706, and 0.688, respectively. The combination of the three miRNAs using multiple logistic regression analysis showed a larger AUC (0.852) that was more efficient for the diagnosis of PCOS. In addition, logistic binary regression analyses show miR-222 is positively associated with serum insulin, while miR-146a is negatively associated with serum testosterone. Furthermore, bioinformatics analysis indicated that the predicted targets function of the three miRNAs mainly involved in the metastasis, cell cycle, apoptosis and endocrine. Conclusion: Serum miRNAs are differentially expressed between PCOS patients and controls. We identified and validated a class of three serum miRNAs that could act as novel non-invasive biomarkers for diagnosis of PCOS. These miRNAs may be involved in the pathogenesis of PCOS

Pre-Pregnancy Body Mass Index in Relation to Infant Birth Weight and Offspring Overweight/Obesity: A Systematic Review and Meta-Analysis

<div><p>Background</p><p>Overweight/obesity in women of childbearing age is a serious public-health problem. In China, the incidence of maternal overweight/obesity has been increasing. However, there is not a meta-analysis to determine if pre-pregnancy body mass index (BMI) is related to infant birth weight (BW) and offspring overweight/obesity.</p><p>Methods</p><p>Three electronic bibliographic databases (MEDLINE, EMBASE and CINAHL) were searched systematically from January 1970 to November 2012. The dichotomous data on pre-pregnancy overweight/obesity and BW or offspring overweight/obesity were extracted. Summary statistics (odds ratios, ORs) were used by Review Manager, version 5.1.7.</p><p>Results</p><p>After screening 665 citations from three electronic databases, we included 45 studies (most of high or medium quality). Compared with normal-weight mothers, pre-pregnancy underweight increased the risk of small for gestational age (SGA) (odds ratios [OR], 1.81; 95% confidence interval [CI], 1.76–1.87); low BW (OR, 1.47; 95% CI, 1.27–1.71). Pre-pregnancy overweight/obesity increased the risk of being large for gestational age (LGA) (OR, 1.53; 95% CI, 1.44–1.63; and OR, 2.08; 95% CI; 1.95–2.23), high BW (OR, 1.53; 95% CI, 1.44–1.63; and OR, 2.00; 95% CI; 1.84–2.18), macrosomia (OR, 1.67; 95% CI, 1.42–1.97; and OR, 3.23; 95% CI, 2.39–4.37), and subsequent offspring overweight/obesity (OR, 1.95; 95% CI, 1.77–2.13; and OR, 3.06; 95% CI, 2.68–3.49), respectively. Sensitivity analyses revealed that sample size, study method, quality grade of study, source of pre-pregnancy BMI or BW had a strong impact on the association between pre-pregnancy obesity and LGA. No significant evidence of publication bias was observed.</p><p>Conclusions</p><p>Pre-pregnancy underweight increases the risk of SGA and LBW; pre-pregnancy overweight/obesity increases the risk of LGA, HBW, macrosomia, and subsequent offspring overweight/obesity. A potential effect modification by maternal age, ethnicity, gestational weight gain, as well as the role of gestational diseases should be addressed in future studies.</p></div

Investigation into the antimicrobial action and mechanism of a novel endogenous peptide β-casein 197 from human milk

Abstract A novel endogenous peptide cleaved from 197–213 AA of β-casein, named β-casein 197, was identified by tandem mass spectrometry. β-casein 197 constituted a significant proportion of the peptide content in preterm milk. This study investigated the antibacterial effects and mechanisms against common pathogenic bacteria. Six bacterial strains were selected for this study: Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Klebsiella pneumonia and Bacillus subtilis. After synthesis, serial twofold dilutions of β-casein 197 were added to select for sensitive bacteria. The disk diffusion method and analysis of bacterial staining were used to identify antibacterial effect, while DNA-binding, scanning electron microscopy and transmission electron microscopy were used to explore antimicrobial mechanisms. Disk diffusion showed that E. coli, S. aureus and Y. enterocolitica were sensitive to the β-casein 197. In addition, live/dead fluorescent staining also confirmed antibacterial effects. Scanning electron and transmission electron microscopy revealed affected extracellular and intracellular structure for three species of bacteria, while a DNA-binding assay showed that the antimicrobial activity did not occur through DNA binding. This study suggests that β-casein 197 has antimicrobial activity against common pathogenic bacteria in newborns with infection. The peptide induced membrane permeabilization but did not bind to genomic DNA. Based on our findings, β-casein 197 has potential clinical value for preventing infections of premature infants

Insight into the Effects of Adipose Tissue Inflammation Factors on miR-378 Expression and the Underlying Mechanism

Background/Aims: Obesity and the related metabolic syndrome have emerged as major public health issues in modern society. miRNAs have been shown to play key roles in regulating obesity-related metabolic syndrome, and some miRNAs regulated by adiponectin were identified as novel targets for controlling adipose tissue inflammation. miR-378 is a candidate target that was shown to be involved in adipose differentiation, mitochondrial metabolism and systemic energy homeostasis. However, little is known about the regulatory mechanisms of miR-378 expression. To better understand the physiological role of miR-378 in obesity and metabolic syndrome, it is crucial that we understand the regulation of miR-378 gene expression in human adipocytes. Methods: In this study, we investigated the effects of adipokines and inflammatory cytokines on miR-378 expression using Real-time PCR and the potential regulatory mechanisms using luciferase reporter assays and electrophoretic mobility shift assay (EMSA). Results: We found that adipokines and cytokines upregulated miR-378 expression primarily through SREBP and C/EBP binding sites in the miR-378 promoter region. Conclusion: Our findings showed that adipokines induced miR-378 expression and revealed the most likely mechanism of adipokine-induced miR-378 dysregulation in human adipocytes. miRNAs have been shown to function in regulating obesity-related metabolic syndrome, and miR-378 may be a novel target for controlling adipose tissue inflammation. This study offers a theoretical basis for understanding systemic adipose tissue inflammation and may provide new strategies for clinical treatment