Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
217
result(s) for
"Lu, Weitao"
Sort by:
A Hybrid Thresholding Algorithm for Cloud Detection on Ground-Based Color Images
2011
Cloud detection is the precondition for deriving other information (e.g., cloud cover) in ground-based sky imager applications. This paper puts forward an effective cloud detection approach, the Hybrid Thresholding Algorithm (HYTA) that fully exploits the benefits of the combination of fixed and adaptive thresholding methods. First, HYTA transforms an input color cloud image into a normalized blue/red channel ratio image that can keep a distinct contrast, even with noise and outliers. Then, HYTA identifies the ratio image as either unimodal or bimodal according to its standard deviation, and the unimodal and bimodal images are handled by fixed and minimum cross entropy (MCE) thresholding algorithms, respectively. The experimental results demonstrate that HYTA shows an accuracy of 88.53%, which is far higher than those of either fixed or MCE thresholding alone. Moreover, HYTA is also verified to outperform other state-of-the-art cloud detection approaches.
Journal Article
Sex differences of fall-risk-increasing drugs in the middle-aged and elderly: a descriptive, cross-sectional study of FDA adverse event reporting system
2024
It’s well known that sex is a risk factor for the occurrence of adverse events (AEs), most of which have found sex differences. Real-world data studies on the sex differences of fall-risk-increasing drugs (FRIDs) are few and far between, with most small-scale retrospective studies based on FRID classes. To establish a list of FRIDs and describe their sex differences, we used preferred terms from the Medical Dictionary for Regulatory Activities to search for AEs in the FDA Adverse Event Reporting System (FAERS), and then perform disproportionality analyses and female/male ratio analyses. During January 2004 to March 2023, 101,746 fall-related AEs were reported in FAERS from patients aged 50 to 100, with 68,492 (67.3%) females and 32,547 (32.0%) males. We found 261 signals for females while 284 for males. For females, the top 3 signals with the highest reporting odds ratio (ROR) were anethole trithione, clopenthixol, nikethamide (ROR: 388.88, 212.10, 113.94), while the top 3 signals with the highest lower limit of information component (IC
025
) were nikethamide, anethole trithione, benzbromarone (IC
025
: 3.91, 3.15, 2.49). For males, the top 3 signals with the highest ROR were fluprednidene acetate, potassium hydroxide, ketazolam (ROR: 216.86, 108.43, 108.43), while the top 3 signals with the highest IC
025
were clomethiazole, piribedil, melperone (IC
025
: 3.31, 3.24, 2.99). Moreover, among the 119 shared signals found between males and females, 33 were positively correlated with falls in females and 38 with falls in males. Signals showing significant sex differences were mainly concentrated on agents of the immune, nervous, musculo-skeletal, and cardiovascular systems. We offered a series of FRIDs and suggested their sex differences in falls through the FAERS. In the future, it is essential to balance the inclusion of women and men, and analyse sex-stratified for FRIDs.
Journal Article
The Expression of Antibacterial Peptide Turgencin A in Pichia pastoris and an Analysis of Its Antibacterial Activity
2023
Antibiotic resistance to pathogenic bacteria is becoming an increasing public health threat, and identifying alternatives to antibiotics would be an effective solution to the problem of drug resistance. Antimicrobial peptides are small peptides produced by various organisms; they are considered to be adequate antibiotic substitutes because they have intense, broad−spectrum antibacterial activity and stability, are widely available, and target strains do not quickly develop resistance. Recent research on antimicrobial peptides has shown that they have broad potential for applications in medicine, agriculture, food, and animal feed. Turgencin A is a potent antimicrobial peptide isolated from the Arctic sea squirt. We established a His-tagged expression system for Pichia pastoris and developed a rTurgencin A using the recombinant expression in Pichia pastoris with nickel column purification. This antimicrobial peptide showed intense antimicrobial activity against Gram-positive and Gram-negative bacteria and a good stability at most temperatures and pHs, as well as in various protease and salt ion concentrations, but underwent a significant decrease in stability in high-temperature and low-pH environments. Turgencin A induced bacterial membrane rupture, resulting in content leakage and subsequent cell death. It was also shown to have low hemolytic activity. This study provides primary data for the industrial production and application of the antimicrobial peptide Turgencin A.
Journal Article
Adverse event profile differences among long-acting gonadotropin-releasing hormone analogs: A real-world, pharmacovigilance study
by
Feng, Huancun
,
Lu, Weitao
,
Chen, Yuting
in
Adolescent
,
Adult
,
Adverse Drug Reaction Reporting Systems
2025
Long-acting Gonadotropin-releasing hormone analogs(GnRHa), including leuprolide, goserelin, histrelin, buserelin, triptorelin, have been widely used for a variety of diseases including prostate cancer, breast cancer, endometriosis, uterine leiomyomas, and central precocious puberty (CPP). However, their real-world safety profile differences have not been adequately compared.
We aimed to investigate the adverse event (AE) profile differences of long-acting GnRHa reported by the US Food and Drug Administration Adverse Event Reporting System (FAERS).
All indications were searched long-acting GnRHa, as primary suspect drugs, from FAERS data (January 2004 to September 2023). We performed disproportionality analyses by reporting odds ratios (ROR) and conducted univariate and multivariate logistical regression analyses to determine the odds ratio (OR) of serious AEs associated with long-acting GnRHa under different exposure factors.
Reproductive system and breast disorders accounted for the greatest proportion of adverse events among the five long-acting GnRHa formulations analyzed. Both buserelin and histrelin showed distinct adverse effect profiles, with buserelin demonstrating a higher incidence of gastrointestinal disorders and histrelin showing a greater propensity for psychiatric disorders. Logistic regression analysis revealed these five medications carried an elevated risk of significant medical events, and this risk was notably lower in pediatric patients (<18 years) compared to adult populations (≥18 years).
Significant disparities exist between the adverse event profiles of long-acting GnRHa. The identification of high-risk factors and the enhancement of AEs monitoring are crucial during clinical application.
Journal Article
A High-Accuracy, High Anti-Noise, Unbiased Frequency Estimator Based on Three CZT Coefficients for Deep Space Exploration Mission
2022
Deep space exploration navigation requires high accuracy of the Doppler measurement, which is equivalent to a frequency estimation problem. Because of the fence effect and spectrum leakage, the frequency estimation performances, which is based on the FFT spectrum methods, are significantly affected by the signal frequency. In this paper, we propose a novel method that utilizes the mathematical relation of the three Chirp-Z Transform (CZT) coefficients around the peak spectral line. The realization, unbiased performance, and algorithm parameter setting rule of the proposed method are described and analyzed in detail. The Monte Carlo simulation results show that the proposed method has a better anti-noise and unbiased performance compared with some traditional estimator methods. Furthermore, the proposed method is utilized to process the raw data of MEX and Tianwen-1 satellites received by Chinese Deep Space Stations (CDSS). The results show that the Doppler estimation accuracy of MEX and Tianwen-1 are both about 3 millihertz (mHz) in 1-s integration, which is consistent with that of ESA/EVN/CDSN and a little better than that of the Chinese VLBI network (CVN). Generally, this proposed method can be effectively utilized to support Chinese future deep space navigation missions and radio science experiments.
Journal Article
Research and Verification of a Novel Interferometry Method by Joint Processing of Downlink Pseudo-Noise Ranging and DOR Signals for Deep Space Exploration
2024
The remarkably long distances covered by deep space probes result in extremely weak downlink signals, which poses great challenges for ground measurement systems. In the current climate, improving the comprehensive utilization of downlink signal power to increase the detection distance or enhance the measurement accuracy is of great significance in deep space exploration. Facing this problem, we analyze the delta Differential One-way Range (ΔDOR) error budget of the X-band of the China Deep Space Network (CDSN). Then, we propose a novel interferometry method that detunes one group of DOR beacons and reuses the clock components of regenerative pseudo-code ranging signals for interferometry delay estimation. The primary advantage of this method is its ability to enhance the power utilization efficiency of downlink signals, thereby facilitating more efficient tracking and measurement without necessitating additional design requirements for deep space transponders. Finally, we analyze and verify the correctness and effectiveness of our proposed method using measured data from CDSN. Our results indicate that the proposed method can save approximately 13% of the downlink signal power and increase the detection distance by about 6.25% using typical modulation parameters. Furthermore, if the relative power of other signal components remains unchanged, the power of the DOR tone can be directly increased by more than 100%, improving the deep space exploration ability more significantly.
Journal Article
Antibacterial peptide PMAP-37(F34-R), expressed in Pichia pastoris, is effective against pathogenic bacteria and preserves plums
by
Lu, Weitao
,
Sun, Yanyan
,
Dong, Chunming
in
Antibacterial activity
,
Antibacterial mechanism
,
Antibiotics
2023
Background
Recently, researchers have focused on the search for alternatives to conventional antibiotics. Antimicrobial peptides are small bioactive peptides that regulate immune activation and have antibacterial activity with a reduced risk of bacterial resistance. Porcine myeloid antibacterial peptide 37 (PMAP-37) is a small-molecule peptide with broad-spectrum antibacterial activity isolated from pig bone marrow, and PMAP-37(F34-R) is its analogue. In this study, PMAP-37(F34-R) was recombinantly expressed in
Pichia pastoris
, and the recombinant peptide was further investigated for its antibacterial properties, mechanism and preservative in plums.
Results
To obtain a
Pichia pastoris
strain expressing PMAP-37(F34-R), we constructed a plasmid expressing recombinant PMAP-37(F34-R) (pPICZα-PMAP-37(F34-R)-A) and introduced it into
Pichia pastoris
. Finally, we obtained a highly active recombinant peptide, PMAP-37(F34-R), which inhibited the activity of both Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration is 0.12–0.24 µg/mL, and it can destroy the integrity of the cell membrane, leading to cell lysis. It has good stability and is not easily affected by the external environment. Hemolysis experiments showed that 0.06 µg/mL-0.36 µg/mL PMAP-37(F34-R) had lower hemolysis ability to mammalian cells, and the hemolysis rate was below 1.5%. Additionally, 0.36 µg/mL PMAP-37(F34-R) showed a good preservative effect in plums. The decay and weight loss rates of the treated samples were significantly lower than those of the control group, and the respiratory intensity of the fruit was delayed in the experimental group.
Conclusions
In this study, we constructed a recombinant
Pichia pastoris
strain, which is a promising candidate for extending the shelf life of fruits and has potential applications in the development of new preservatives.
Graphical Abstract
Journal Article
Characteristics of unconnected upward leaders initiated from tall structures observed in Guangzhou
by
Chen, Luwen
,
Chen, Shaodong
,
Lu, Weitao
in
Atmospheric sciences
,
cloud-to-ground lightning
,
Earth sciences
2012
Forty‐five unconnected upward leaders (UULs) occurred in 19 downward negative flashes are analyzed. Each observed UUL is initiated by a downward stepped leader before a new strike point is struck. For each UUL, several parameters are determined when possible mainly by using high‐speed images: inception height, inception time prior to return stroke (RS), horizontal distance from the flash's strike point, two‐dimensional (2D) distance between the nearest downward leader branch tip and the UUL's inception point at its inception time, 2D length, and 2D average propagation velocity. Their values range from 40 to 503 m (number of samples: 45), <0.1 to 1.32 ms (38), 20 m to 1.3 km (38), 99 to 578 m (21), 0.48 to 399 m (45), and 5.79 to 33.8 × 104 m s−1 (22), respectively. 86% (19/22) of the velocities are smaller than 1.7 × 105 m s−1. No UUL with an inception time prior to RS greater than 0.5 ms is initiated from a structure lower than 300 m. Those UULs with inception heights lower than 300 m seldom exhibit lengths longer than 50 m and only can be initiated by flashes within approximately 600 m, while those higher than 400 m can even reach several hundred meters and be initiated by flashes over 1 km away. The maximum distances for the downward leaders to attract the UULs with inception heights from 100 to 200 m, 200 to 300 m, and over 400 m are approximately 350 m, 450 m, and 600 m, respectively. Key Points Cases and statistical analysis of unconnected upward positive leaders Observation of lightning discharges striking a city with many tall structures The data can help us estimate the effect of downward leader on upward leader
Journal Article
Proline induces calcium-mediated oxidative burst and salicylic acid signaling
2011
Although free proline accumulation is a well-documented phenomenon in many plants in response to a variety of environmental stresses, and is proposed to play protective roles, high intracellular proline content, by either exogenous application or endogenous over-production, in the absence of stresses, is found to be inhibitory to plant growth. We have shown here that exogenous application of proline significantly induced intracellular Ca²⁺ accumulation in tobacco and calcium-dependent ROS production in Arabidopsis seedlings, which subsequently enhanced salicylic acid (SA) synthesis and PR genes expression. This suggested that proline can promote a reaction similar to hypersensitive response during pathogen infection. Other amino acids, such as glutamate, but not arginine and phenylalanine, were also found to be capable of inducing PR gene expression. In addition, proline at concentration as low as 0.5 mM could induce PR gene expression. However, proline could not induce the expression of PDF1.2 gene, the marker gene for jasmonic acid signaling pathway. Furthermore, proline-induced SA production is mediated by NDR1-dependent signaling pathway, but not that mediated by PAD4. Our data provide evidences that exogenous proline, and probably some other amino acids can specifically induce SA signaling and defense response.
Journal Article