463 research outputs found

    Advancing Text-Driven Chest X-Ray Generation with Policy-Based Reinforcement Learning

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    Recent advances in text-conditioned image generation diffusion models have begun paving the way for new opportunities in modern medical domain, in particular, generating Chest X-rays (CXRs) from diagnostic reports. Nonetheless, to further drive the diffusion models to generate CXRs that faithfully reflect the complexity and diversity of real data, it has become evident that a nontrivial learning approach is needed. In light of this, we propose CXRL, a framework motivated by the potential of reinforcement learning (RL). Specifically, we integrate a policy gradient RL approach with well-designed multiple distinctive CXR-domain specific reward models. This approach guides the diffusion denoising trajectory, achieving precise CXR posture and pathological details. Here, considering the complex medical image environment, we present "RL with Comparative Feedback" (RLCF) for the reward mechanism, a human-like comparative evaluation that is known to be more effective and reliable in complex scenarios compared to direct evaluation. Our CXRL framework includes jointly optimizing learnable adaptive condition embeddings (ACE) and the image generator, enabling the model to produce more accurate and higher perceptual CXR quality. Our extensive evaluation of the MIMIC-CXR-JPG dataset demonstrates the effectiveness of our RL-based tuning approach. Consequently, our CXRL generates pathologically realistic CXRs, establishing a new standard for generating CXRs with high fidelity to real-world clinical scenarios

    Development of an enhanced analytical method utilizing pepper matrix as an analyte protectant for sensitive GC-MS/MS detection of dimethipin in animal-based food products

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    Herein, an analytical method using gas chromatography-tandem mass spectrometry (GC- MS/MS) was devised to detect the presence of the troublesome pesticide dimethipin in various animal-based food products, including chicken, pork, beef, eggs, and milk. The injection port was primed with a matrix derived from pepper leaves that acts as an analyte protectant (AP) to safeguard the target compound from thermal degradation during gas chromatography. The presence of AP resulted in a remarkable limit of quantification of 0.005 mg/kg for dimethipin in five matrices. Three different versions (original, EN, and AOAC) of the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method were compared for dimethipin extraction, with a double-layer solid-phase extraction (SPE) cartridge utilized for matrix purification. A seven-point external calibration curve was established for dimethipin in the five matrices, demonstrating excellent linearity with determination coefficients (R2) ≥ 0.998. The developed quantitative method was validated by fortifying each matrix with three different concentrations of standard dimethipin, and the average recovery fell within the acceptable range outlined in the CODEX guidelines (ranging from 88.8% to 110.0%), with a relative standard deviation (RSD) of ≤ 11.97%. This method effectively addresses the challenge of analyzing dimethipin and can therefore be used as a routine monitoring tool for dimethipin across various matrices

    Clinical Characteristics and Risk Factors for Nosocomial Candidemia in Medical Intensive Care Units: Experience in a Single Hospital in Korea for 6.6 Years

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    The aim of this study was to determine candidemia incidence among patients in a medical intensive-care unit (MICU) and the associated mortality rate and to identify risk factors associated with candidemia. We retrospectively performed a 1:3 matched case-control study of MICU patients with candidemia. Controls were matched for sex, age, and Acute Physiology and Chronic Health Evaluation (APACHE) II score. Candidemia incidence was 9.1 per 1,000 admissions. The most common pathogen was Candida albicans. Crude mortality was 96% among candidemia patients and 52% among controls (P<0.001). Mortality differed significantly between the groups according to Kaplan-Meier survival analysis (P=0.024). Multivariate analysis identified the following independent risk factors for candidemia: central venous catheterization (odds ratio [OR] = 3.2, 95% confidence interval [CI]=1.2-9.0), previous steroid therapy (OR=4.7, 95% CI=1.8-12.1), blood transfusion during the same admission period (OR=6.3, 95% CI=2.4-16.7), and hepatic failure upon MICU admission (OR=6.9, 95% CI=1.7-28.4). In conclusion, we identify an additional independent risk factor for candidemia, the presence of hepatic failure on MICU admission. Therefore, increased awareness of risk factors, including hepatic failure, is necessary for the management of candidemia

    Copy number variation at leptin receptor gene locus associated with metabolic traits and the risk of type 2 diabetes mellitus

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    <p>Abstract</p> <p>Background</p> <p>Recent efforts have been made to link complex human traits and disease susceptibility to DNA copy numbers. The leptin receptor (LEPR) has been implicated in obesity and diabetes. Mutations and genetic variations of <it>LEPR </it>gene have been discovered in rodents and humans. However, the association of DNA copy number variations at the <it>LEPR </it>gene locus with human complex diseases has not been reported. In an attempt to study DNA copy number variations associated with metabolic traits and type 2 diabetes mellitus (T2DM), we targeted the <it>LEPR </it>gene locus in DNA copy number analyses.</p> <p>Results</p> <p>We identified DNA copy number variations at the <it>LEPR </it>gene locus among a Korean population using genome-wide SNP chip data, and then quantified copy numbers of the E2 DNA sequence in the first two exons overlapped between <it>LEPR </it>and <it>LEPROT </it>genes by the quantitative multiplex PCR of short fluorescent fragment (QMPSF) method. Among the non-diabetic subjects (n = 1,067), lower E2 DNA copy numbers were associated with higher fasting glucose levels in men (<it>p </it>= 1.24 × 10<sup>-7</sup>) and women (<it>p </it>= 9.45 × 10<sup>-5</sup>), as well as higher total cholesterol levels in men (<it>p </it>= 9.96 × 10<sup>-7</sup>). In addition, the significant association between lower E2 DNA copy numbers and lower level of postprandial 2hr insulin was evident only in non-diabetic women, whereas some obesity-related phenotypes and total cholesterol level exhibited significant associations only in non-diabetic men. Logistic regression analysis indicated that lower E2 DNA copy numbers were associated with T2DM (odds ratio, 1.92; 95% CI, 1.26~2.96; p < 0.003) in our nested case-control study. Interestingly, the E2 DNA copy number exhibited a negative correlation with LEPR gene expression, but a positive correlation with LEPROT gene expression.</p> <p>Conclusions</p> <p>This work suggests that a structural variation at the <it>LEPR </it>gene locus is functionally associated with complex metabolic traits and the risk of T2DM.</p

    Recent Advances in Rapid Detection Techniques for Pesticide Residue: A Review

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    As an important chemical pollutant affecting the safety of agricultural products, the on-site and efficient detection of pesticide residues has become a global trend and hotspot in research. These methodologies were developed for simplicity, high sensitivity, and multiresidue detection. This review introduces the currently available technologies based on electrochemistry, optical analysis, biotechnology, and some innovative and novel technologies for the rapid detection of pesticide residues, focusing on the characteristics, research status, and application of the most innovative and novel technologies in the past 10 years, and analyzes challenges and future development prospects. The current review could be a good reference for researchers to choose the appropriate research direction in pesticide residue detection

    The Prevalence and Evolution of Anemia Associated with Tuberculosis

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    Tuberculosis (TB) may produce abnormalities in the peripheral blood, including anemia. However, the evolution of TB-associated anemia with short-term combination anti-TB chemotherapy has not been well elucidated. The aim of this study was to characterize TB-associated anemia by clarifying its prevalence, characteristics, and evolution, through involving large numbers of patients with TB. The medical records of adult patients with TB diagnosed between June 2000 and May 2001 were reviewed. Among 880 patients with TB, 281 (31.9%) had anemia on diagnosis of TB, however, the hemoglobin concentration was less than 10 g/dL in only 45 patients (5.0%). Anemia was more frequently associated with the female and old age. Good treatment response, young age (≤65 yr-old) and initial high hemoglobin were the predictive factor for resolution of anemia. In 202 patients with anemia (71.9%), anemia was normocytic and normochromic. During or after anti-TB treatment, anemia was resolved in 175 (64.6%) out of 271 patients without iron intake. The mean duration of resolution from the initiation of anti-TB treatment was 118.8±113.2 days. In conclusion, anemia is a common hematological abnormality in patients with TB and close observation is sufficient for patients with TB-associated anemia, because TB-associated anemia is usually mild and resolves with anti-TB treatment

    Sequential Bilateral Lung Resection in a Patient with Mycobacterium Abscessus Lung Disease Refractory to Medical Treatment

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    Mycobacterium abscessus (M. abscessus) is the second most common nontuberculous mycobacteria (NTM) in South Korea. Nevertheless, the diagnosis and treatment of M. abscessus lung disease can be problematic. Surgical resection has been tried for patients with localized M. abscessus lung disease refractory to medical treatment. Here, we report on a 25-year-old woman with M. abscessus lung disease who had been diagnosed and treated three times for pulmonary tuberculosis. She was initially diagnosed as having M. intracellulare lung disease; however, M. abscessus was isolated after several months of medication. She had multiple bronchiectatic and cavitary lesions bilaterally, and M. abscessus was repeatedly isolated from her sputa despite prolonged treatment with clarithromycin, ethambutol, moxifloxacin, and amikacin. She improved only after sequential bilateral lung resection. Based on the experience with this patient, we suggest that, if medical treatment fails, surgical resection of a diseased lung should be considered even in patients with bilateral lesions
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