Changrojas0466

To develop and validate a machine learning model based on radiomic features derived from

F-fluorodeoxyglucose (

F-FDG) positron emission tomography/computed tomography (PET/CT) images to preoperatively predict the pathological grade in patients with pancreatic ductal adenocarcinoma (PDAC).

A total of 149 patients (83 men, 66 women, mean age 61years old) with pathologically proven PDAC and a preoperative

F-FDG PET/CT scan between May 2009 and January 2016 were included in this retrospective study. The cohort of patients was divided into two separate groups for the training (99 patients) and validation (50 patients) in chronological order. Radiomics features were extracted from PET/CT images using Pyradiomics implemented in Python, and the XGBoost algorithm was used to build a prediction model. Conventional PET parameters, including standardized uptake value, metabolic tumor volume, and total lesion glycolysis, were also measured. The quality of the proposed model was appraised by means of receiver operating characteristics (ROC) and areas under the ROC curve (AUC).

The prediction model based on a twelve-feature-combined radiomics signature could stratify PDAC patients into grade 1 and grade 2/3 groups with AUC of 0.994 in the training set and 0.921 in the validation set.

The model developed is capable of predicting pathological differentiation grade of PDAC based on preoperative

F-FDG PET/CT radiomics features.

The model developed is capable of predicting pathological differentiation grade of PDAC based on preoperative 18F-FDG PET/CT radiomics features.

Informed by the evidence of links between physiology of stress and parturition, we review recent epidemiologic evidence (2015-2020) of antenatal depression as a risk factor for preterm birth (PTB). We also explain racial/ethnic disparities in depression and preterm birth as a consequence of structural racism.

Epidemiologic evidence is consistent in linking antepartum depression with an elevated risk of PTB. Antidepressant usage has been linked with an elevated risk of PTB. However, recent evidence suggests that severity of depression is the underlying driver of the elevated risk attributed to antidepressant usage. The number of depressive symptoms, as a proxy for severity of maternal stress, may be a more informative predictor of PTB than criterion based predictors. selleck chemicals Across various study designs, measurement modalities, and populations, antenatal depression predicts an elevated risk of delivering preterm. The physiology of stress provides a plausible explanation for this observation. Excessive stress-induc maternal stress, may be a more informative predictor of PTB than criterion based predictors. Across various study designs, measurement modalities, and populations, antenatal depression predicts an elevated risk of delivering preterm. The physiology of stress provides a plausible explanation for this observation. Excessive stress-induced elevations in maternal and then fetal HPA hormones can alter maternal and fetal homeostasis and hasten the timing of parturition. Antenatal depression and exposure to structural racism are two stressors that can trigger the maternal stress response. Chronically elevated levels of stress hormones among women of color in the USA provide a likely physiologic explanation for Black-White disparities in the risk of PTB. Focusing on the number of depressive symptoms as the more informative predictor of PTB raises several questions. We consider these questions as well as directions for future research in the context of recent advances in the field.Heading date is an important agronomic trait of rice (Oryza sativa L.) and is regulated by numerous genes, some of which exhibit functional divergence in a genetic background-dependent manner. Here, we identified a late heading date 7 (lhd7) mutant that flowered later than wild-type Zhonghua 11 (ZH11) under natural long-day (NLD) conditions. Map-based cloning facilitated by the MutMap strategy revealed that LHD7 was on the same locus as OsPRR37 but exhibited a novel function as a promoter of heading date. A single-nucleotide mutation of G-to-A in the coding region caused a substitution of aspartic acid for glycine at site 159 within the pseudo-receiver (PR) domain of OsPRR37. Transcriptional analysis revealed that OsPRR37 suppressed Ghd7 expression in both ZH11 background under NLD conditions and the Zhenshan 97 background under natural short-day conditions. Consistently, the expression of Ehd1, Hd3a and RFT1 was enhanced by OsPRR37 in the ZH11 background. Genetic analysis indicated that the promotion of heading date and reduction in grain yield by OsPRR37 were partially dependent on Ghd7. Further investigation showed that the alternative function of OsPRR37 required an intact Ghd7-related regulatory pathway involving not only its upstream regulators OsGI and PhyB but also its interacting partner Hd1. Our study revealed the distinct role of OsPRR37 in the ZH11 background, which provides a more comprehensive understanding of OsPRR37 function and enriches the theoretical bases for improvement of rice heading date in the future.

A novel generation of PET scanners based on silicon (Si)-photomultiplier (PM) technology has recently been introduced. Concurrently, there has been development of new reconstruction methods aimed at increasing the detectability of small lesions without increasing image noise. The combination of new detector technologies and new reconstruction algorithms has been found to increase image quality. However, it is unknown to what extent the demonstrated improvement of image quality is due to scanner hardware development or improved reconstruction algorithms. To isolate the contribution of the hardware, this study aimed to compare the ability to detect small hotspots in phantoms using the latest generation SiPM-based PET/CT scanner (GE Discovery MI) relative to conventional PM-based PET/CT scanner (GE Discovery 690), using identical reconstruction protocols.

Two different phantoms (NEMA body and Jasczcak) with fillable spheres (31 μl to 26.5 ml) and varying sphere-to-background-ratios (SBR) were scanned in one bed position for 15-600 s on both scanners.