74 research outputs found
Thermoelectric transport properties of diamond-like Cu_(1−x)Fe_(1+x)S_2 tetrahedral compounds
Polycrystalline samples with the composition of Cu _(1−x)Fe_(1+x)S_2 (x = 0, 0.01, 0.03, 0.05, 0.1) were synthesized by a melting-annealing-sintering process. X-ray powder diffraction reveals all the samples are phase pure. The backscattered electron image and X-ray map indicate that all elements are distributed homogeneously in the matrix. The measurements of Hall coefficient, electrical conductivity, and Seebeck coefficient show that Fe is an effective n-type dopant in CuFeS_2. The electron carrier concentration of Cu_(1−x)Fe_(1+x)S_2 is tuned within a wide range leading to optimized power factors. The lattice phonons are also strongly scattered by the substitution of Fe for Cu, leading to reduced thermal conductivity. We use Debye approximation to model the low temperature lattice thermal conductivity. It is found that the large strain field fluctuation introduced by the disordered Fe ions generates extra strong phonon scatterings for lowered lattice thermal conductivity
Investigating the value of dual-layer spectral detector CT in distinguishing resectable pancreatic ductal adenocarcinoma from mass-forming chronic pancreatitis
Background and Purpose: Accurate differentiation of pancreatic ductal adenocarcinoma (PDAC) from mass-forming chronic pancreatitis (MFCP) is clinically significant. The application of dual-layer spectral detector CT (DLCT) in pancreas has been explored. This study aimed to investigate the value of DLCT in distinguishing resectable PDAC from MFCP. Methods: We retrospectively collected data of 33 patients with resectable PDAC and 19 patients with MFCP admitted to Fudan University Shanghai Cancer Center from September 1, 2021 to May 31, 2023. Prior to surgery, patients underwent enhanced DLCT scans, including arterial phase (AP), parenchymal phase (PP) and venous phase (VP). DLCT quantitative parameters, including attenuation enhancement fraction (AEF), lesion-to-parenchyma ratio (LPR) and iodine enhancement fraction (IEF) were calculated. Difference analysis was conducted using independent sample t-test or chi-square test. Univariate and multivariate analyses were performed using binary logistic regression. Receiver operating characteristic (ROC) curves were used for performance evaluation. P<0.05 was considered statistically significant. Results: Statistically significant differences were observed between PDAC and MFCP in AEF_AP/PP, LPR40_VP, IEF_PP/VP, carbohydrate antigen 19-9 (CA19-9) and double-duct sign (all P<0.05). The spectral combined model composed of LPR40_VP and IEF_PP/VP exhibited the best discriminatory efficacy, surpassing CA19-9, double-duct sign and AEF_AP/PP (all P<0.05). The combined model demonstrated an area under curve (AUC) of 0.841, sensitivity of 90%, specificity of 73%, and accuracy of 79%. Conclusion: DLCT has certain potential in differentiating resectable PDAC from MFCP. Spectral quantitative parameters can complement CA19-9 and outcome shortcomings of conventional CT in distinguishing resectable PDAC from MFCP
Entropy as a Gene‐Like Performance Indicator Promoting Thermoelectric Materials
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138909/1/adma201702712.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138909/2/adma201702712-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138909/3/adma201702712_am.pd
Influence of Lactobacillus plantarum P-8 on Fermented Milk Flavor and Storage Stability
Previously, we demonstrated that the flavor of milk fermented with Lactobacillus delbrueckii subsp. bulgaricus (IMAU20401) and Streptococcus thermophilus (IMAU40133) at a 1:1000 ratio was superior to that of other ratios of the two strains. In this study, Lactobacillus plantarum P-8 was used as the probiotic bacterium. Six ratios (1:1, 1:5, 1:10, 1:50, 1:100, and 1:1000) of L. plantarum P-8 to yogurt starter were evaluated. A total of 66 volatile compounds including aldehydes, ketones, acids, alcohols, esters, alcohols, and aromatic compounds were identified in milk fermented with the six different L. plantarum P-8 to yogurt starter ratios at 0 d of storage. In particular, key flavor compounds, such as 3-methylbutanal, hexanal, (E)-2-octenal, nonanal, 2-heptanone, 2-nonanone, and acetoin, were identified in the 1:100 ratio treatment. Furthermore, the viable cell count, pH, titratable acidity, viscosity, and syneresis of the milk samples were analyzed during fermentation over 14 d of storage at 4°C. The results indicated that milk can be fermented with L. plantarum P-8 in combination with S. thermophilus and L. delbrueckii subsp. bulgaricus, and the physicochemical characteristics of the milk were not affected by the probiotic bacteria
Pressure-Modulated Structural and Magnetic Phase Transitions in Two-Dimensional FeTe: Tetragonal and Hexagonal Polymorphs
Two-dimensional (2D) Fe-chalcogenides with rich structures, magnetisms and
superconductivities are highly desirable to reveal the torturous transition
mechanism and explore their potential applications in spintronics and
nanoelectronics. Hydrostatic pressure can effectively stimulate novel phase
transitions between various ordered states and to plot the seductive phase
diagram. Herein, the structural evolution and transport characteristics of 2D
FeTe were systematically investigated under extreme conditions through
comparing two distinct symmetries, i.e., tetragonal (t-) and hexagonal (h-)
FeTe. We found that 2D t-FeTe presented the pressure-induced transition from
antiferromagnetic to ferromagnetic states at ~ 3 GPa, corresponding to the
tetragonal collapse of layered structure. Contrarily, ferromagnetic order of 2D
h-FeTe was retained up to 15 GPa, evidently confirmed by electrical transport
and Raman measurements. Furthermore, the detailed P-T phase diagrams of both 2D
t-FeTe and h-FeTe were mapped out with the delicate critical conditions. We
believe our results can provide a unique platform to elaborate the
extraordinary physical properties of Fe-chalcogenides and further to develop
their practical applications.Comment: 22 Pages, 5 Figure
Surficial geologic map of the Des Moines Lobe of Iowa, Phase 5: Polk County
https://ir.uiowa.edu/igs_ofm/1030/thumbnail.jp
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Efficacy and safety of erythropoietin for traumatic brain injury
Background
Recent studies regarding the effects of erythropoietin (EPO) for treating traumatic brain injury (TBI) have been inconsistent. This study conducts a meta-analysis of randomized controlled trials (RCTs) to assess the safety and efficacy of EPO for TBI patients at various follow-up time points.
Methods
A literature search was performed using PubMed, Web of Science, MEDLINE, Embase, Google Scholar and the Cochrane Library for RCTs studying EPO in TBI patients published through March 2019. Non-English manuscripts and non-human studies were excluded. The assessed outcomes include mortality, neurological recovery and associated adverse effects. Dichotomous variables are presented as risk ratios (RR) with a 95% confidence interval (CI).
Results
A total of seven RCTs involving 1197 TBI patients (611 treated with EPO, 586 treated with placebo) were included in this study. Compared to the placebo arm, treatment with EPO did not improve acute hospital mortality or short-term mortality. However, there was a significant improvement in mid-term (6 months) follow-up survival rates. EPO administration was not associated with neurological function improvement. Regarding adverse effects, EPO treatment did not increase the incidence of thromboembolic events or other associated adverse events.
Conclusions
This meta-analysis indicates a slight mortality benefit for TBI patients treated with EPO at mid-term follow-up. EPO does not improve in-hospital mortality, nor does it increase adverse events including thrombotic, cardiovascular and other associated complications. Our analysis did not demonstrate a significant beneficial effect of EPO intervention on the recovery of neurological function. Future RCTs are required to further characterize the use of EPO in TBI
Radiogenomics analysis reveals the associations of dynamic contrast-enhanced–MRI features with gene expression characteristics, PAM50 subtypes, and prognosis of breast cancer
BackgroundTo investigate reliable associations between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features and gene expression characteristics in breast cancer (BC) and to develop and validate classifiers for predicting PAM50 subtypes and prognosis from DCE-MRI non-invasively.MethodsTwo radiogenomics cohorts with paired DCE-MRI and RNA-sequencing (RNA-seq) data were collected from local and public databases and divided into discovery (n = 174) and validation cohorts (n = 72). Six external datasets (n = 1,443) were used for prognostic validation. Spatial–temporal features of DCE-MRI were extracted, normalized properly, and associated with gene expression to identify the imaging features that can indicate subtypes and prognosis.ResultsExpression of genes including RBP4, MYBL2, and LINC00993 correlated significantly with DCE-MRI features (q-value < 0.05). Importantly, genes in the cell cycle pathway exhibited a significant association with imaging features (p-value < 0.001). With eight imaging-associated genes (CHEK1, TTK, CDC45, BUB1B, PLK1, E2F1, CDC20, and CDC25A), we developed a radiogenomics prognostic signature that can distinguish BC outcomes in multiple datasets well. High expression of the signature indicated a poor prognosis (p-values < 0.01). Based on DCE-MRI features, we established classifiers to predict BC clinical receptors, PAM50 subtypes, and prognostic gene sets. The imaging-based machine learning classifiers performed well in the independent dataset (areas under the receiver operating characteristic curve (AUCs) of 0.8361, 0.809, 0.7742, and 0.7277 for estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2)-enriched, basal-like, and obtained radiogenomics signature). Furthermore, we developed a prognostic model directly using DCE-MRI features (p-value < 0.0001).ConclusionsOur results identified the DCE-MRI features that are robust and associated with the gene expression in BC and displayed the possibility of using the features to predict clinical receptors and PAM50 subtypes and to indicate BC prognosis
Lactobacillus rhamnosus Probio-M9 Improves the Quality of Life in Stressed Adults by Gut Microbiota
Objective: To evaluate the effect of the probiotic, Lactobacillus rhamnosus Probio-M9 (Probio-M9), on the quality of life in stressed adults. Methods: Twelve postgraduate student volunteers were recruited. Six volunteers received oral Probio-M9 for 21 days, while the remaining six received a placebo instead. Fecal samples were collected from the volunteers before and after the intervention. Metagenomic sequencing, nontargeted metabonomics, and quality-of-life follow-up questionnaires were used to evaluate the impact of Probio-M9 consumption on the gut microbiota and life quality of the volunteers. Results: Probio-M9 improved the psychological and physiological quality-of-life symptoms significantly in stressed adults (p < 0.05). The probiotic intervention was beneficial in increasing and maintaining the diversity of gut microbiota. The abundance of Barnesiella and Akkermansia increased in the probiotics group. The feature metabolites of pyridoxamine, dopamine, and 5-hydroxytryptamine (5-HT) were positively correlated with Barnesiella and Akkermansia levels, which might be why the mental state of the volunteers in the probiotic group improved after taking Probio-M9. Conclusions: We identified that oral Probio-M9 can regulate the stability of gut microbiota and affect the related beneficial metabolites, thereby affecting the quality of life (QoL) of stressed adults. Probio-M9 might improve the psychological and physiological quality of life in stressed adults via the gut-brain axis pathway. The causal relationship should be further explored in future studies
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