22 research outputs found
Synthesis and Biological Evaluation of Novel Allobetulon/AllobetulinâNucleoside Conjugates as AntitumorAgents
Allobetulin is structurally similar tobetulinic acid, inducing the apoptosis of cancer cells with low toxicity. However, both of them exhibited weak antiproliferation against several tumor cell lines. Therefore, the new series of allobetulon/allobetulinânucleoside conjugates 9aâ10i were designed and synthesized for potency improvement. Compounds 9b, 9e, 10a, and 10d showed promising antiproliferative activity toward six tested cell lines, compared to zidovudine, cisplatin, and oxaliplatin based on their antitumor activity results. Among them, compound 10d exhibited much more potent antiproliferative activity against SMMC-7721, HepG2, MNK-45, SW620, and A549 human cancer cell lines than cisplatin and oxaliplatin. In the preliminary study for the mechanism of action, compound 10d induced cell apoptosis and autophagy in SMMC cells, resulting in antiproliferation and G0/G1 cell cycle arrest by regulating protein expression levels of Bax, Bcl-2, and LC3. Consequently, the nucleoside-conjugated allobetulin (10d) evidenced that nucleoside substitution was a viable strategy to improve allobetulin/allobetulonâs antitumor activity based on our present study
Psychometric validation of the fear of progression questionnaire-short form in acute pancreatitis patientsAccessible Summary
Introduction: Fear of progression (FoP) is associated with the quality of life and behavioral change in acute pancreatitis (AP) patients, but lack of assessment tools. Aim: This study aimed to develop and evaluate the psychometric properties of the Fear of Progression Questionnaire-Short Form in AP patients (AP-FoP-Q-SF). Methods: Internal consistency, factorial structure, convergent validity, and criterion validity of AP-FoP-Q-SF were assessed. A receiver operating characteristic (ROC) curve analysis was performed to identify the cutoff value for high FoP. Associations between patient variables and FoP were evaluated using multiple logistic regression. Wilcox rank sum test was used to analyses the costs and length of hospital stay of the patients with high FoP. Results: The two-factor structure showed a good fit. Internal consistency was acceptable (Cronbach's α = 0.771). The cutoff of 26 identified 35.3% of patients with high FoP. High FoP scores were associated with age (OR = 0.96, 95%CI: 0.94â0.98), recurrence times (OR = 1.22, 95%CI: 1.02â1.45) and anxiety (OR = 1.27, 95%CI: 1.16â1.40). Patients with high FoP spent more cost and time in the hospital. Conclusions: The AP-FoP-Q-SF is a good FoP tool for AP patients in China. Implications for practice: Clinicians can use the AP-FoP-Q-SF to assess FoP and take promotion programs to avoid worse effects
Characteristics of Liquid-Hydrocarbon Yield and Biomarkers in Various Thermal-Evolution Stages: A Simulation Experiment with the Middle Jurassic Source Rocks in the Northern Margin of the Qaidam Basin
Although there are many studies on the Jurassic source rocks in the northern margin of the Qaidam Basin, the characteristics of biomarkers and products with the same source rock in different evolutionary stages are still not well understood. Such an understanding is essential for accurately estimating oil and gas resources. In order to explore the hydrocarbon-generation potential of high-quality source rocks of the Middle Jurassic and the evolution of liquid hydrocarbons and biomarkers, we carried out simulation research (under hydrous conditions) at various temperatures (250, 300, 350, 400 and 450 °C) with the mudstone of the Yu 33 well in the Yuka Sag. The results revealed that the “oil window” of the Middle Jurassic source rocks in the Yuka area was 300 °C (simulation temperature, Ro = 0.84%), but this was not the peak of hydrocarbon expulsion, which was gradually reached and stabilized above 350 °C. Overall, the concentration of alkanes and aromatics increased with temperature; although the concentration of alkanes was complex in the low evolutionary stages, temperature (simulated maturity) was still the main factor controlling the change in alkanes and aromatics. Among the maturity parameters of biomarkers, the ratio of ∑tricyclic terpanes/∑hopanes was the most effective parameter for indicating the maturity evolution of the Yuka area, but others were complicated by the increasing temperature. Therefore, when evaluating maturity, the applicability of other parameters needed to be fully considered. The results obtained offer new insights in the research on liquid-hydrocarbon and biomarker evolution of the Middle Jurassic source rocks in the Yuka Sag of the Qaidam Basin
Characteristics of Liquid-Hydrocarbon Yield and Biomarkers in Various Thermal-Evolution Stages: A Simulation Experiment with the Middle Jurassic Source Rocks in the Northern Margin of the Qaidam Basin
Although there are many studies on the Jurassic source rocks in the northern margin of the Qaidam Basin, the characteristics of biomarkers and products with the same source rock in different evolutionary stages are still not well understood. Such an understanding is essential for accurately estimating oil and gas resources. In order to explore the hydrocarbon-generation potential of high-quality source rocks of the Middle Jurassic and the evolution of liquid hydrocarbons and biomarkers, we carried out simulation research (under hydrous conditions) at various temperatures (250, 300, 350, 400 and 450 °C) with the mudstone of the Yu 33 well in the Yuka Sag. The results revealed that the âoil windowâ of the Middle Jurassic source rocks in the Yuka area was 300 °C (simulation temperature, Ro = 0.84%), but this was not the peak of hydrocarbon expulsion, which was gradually reached and stabilized above 350 °C. Overall, the concentration of alkanes and aromatics increased with temperature; although the concentration of alkanes was complex in the low evolutionary stages, temperature (simulated maturity) was still the main factor controlling the change in alkanes and aromatics. Among the maturity parameters of biomarkers, the ratio of âtricyclic terpanes/âhopanes was the most effective parameter for indicating the maturity evolution of the Yuka area, but others were complicated by the increasing temperature. Therefore, when evaluating maturity, the applicability of other parameters needed to be fully considered. The results obtained offer new insights in the research on liquid-hydrocarbon and biomarker evolution of the Middle Jurassic source rocks in the Yuka Sag of the Qaidam Basin
An UltraâLow SelfâDischarge Aqueous|Organic Membraneless Battery with Minimized Br2 CrossâOver
Abstract Batteries dissolving active materials in liquids possess safety and size advantages compared to solidâbased batteries, yet the intrinsic liquid properties lead to material crossâover induced selfâdischarge both during cycling and idle when the electrolytes are in contact, thus highly efficient and costâeffective solutions to minimize crossâover are in high demand. An ultraâlow selfâdischarge aqueous|organic membraneless battery using dichloromethane (CH2Cl2) and tetrabutylammonium bromide (TBABr) added to a zinc bromide (ZnBr2) solution as the electrolyte is demonstrated. The polybromide is confined in the organic phase, and bromine (Br2) diffusionâinduced selfâdischarge is minimized. At 90% state of charge (SOC), the membraneless ZnBr2|TBABr (Z|T) battery shows an open circuit voltage (OCV) drop of only 42 mV after 120 days, 152 times longer than the ZnBr2 battery, and superior to 102 previous reports from all types of liquid active material batteries. The 120âday capacity retention of 95.5% is higher than commercial zincânickel (ZnâNi) batteries and vanadium redox flow batteries (VRFB, electrolytes stored separately) and close to lithiumâion (Liâion) batteries. Z|T achieves >500 cycles (2670 h, 0.5 m electrolyte, 250 folds of membraneless ZnBr2 battery) with â100% Coulombic efficiency (CE). The simple and costâeffective design of Z|T provides a conceptual inspiration to regulate material crossâover in liquidâbased batteries to realize extended operation
CROSS: Cross-Domain Residual-Optimization-Based Structure Strengthening Reconstruction for Limited-Angle CT
Limited-angle computed tomography (CT) is an effective way for practical scenarios due to its flexibility in various complex scanning conditions. However, incomplete projection data will lead to severe wedge artifacts and degraded images, which significantly lower the diagnostic values. To overcome this problem, we propose a novel method termed cross-domain residual-optimization-based structure strengthening (CROSS) reconstruction for limited-angle CT. The proposed CROSS framework consists of three steps, which are conducted on the image domain and measurement domain alternatively. Differing from traditional dual-domain-based algorithms, our CROSS method not only regularizes the reconstruction results on the image space but also the residual-error space, which boosts organ recovery where the area has a larger attenuation coefficient. Besides, the structure-strengthening network is adopted to enhance tissue preservation. Simulated and preclinical datasets are conducted to evaluate the proposed CROSS method. Experiments show that the proposed framework could produce a better performance in artifact removal and edge preservation
Unsharp Structure Guided Filtering for Self-Supervised Low-dose CT Imaging
International audienceLow-dose computed tomography (LDCT) imaging faces great challenges. Although supervised learning has revealed great potential, it requires sufficient and high-quality references for network training. Therefore, existing deep learning methods have been sparingly applied in clinical practice. To this end, this paper presents a novel Unsharp Structure Guided Filtering (USGF) method, which can reconstruct high-quality CT images directly from low-dose projections without clean references. Specifically, we first employ low-pass filters to estimate the structure priors from the input LDCT images. Then, inspired by classical structure transfer techniques, deep convolutional networks are adopted to implement our imaging method which combines guided filtering and structure transfer. Finally, the structure priors serve as the guidance images to alleviate over-smoothing, as they can transfer specific structural characteristics to the generated images. Furthermore, we incorporate traditional FBP algorithms into self-supervised training to enable the transformation of projection domain data to the image domain. Extensive comparisons and analyses on three datasets demonstrate that the proposed USGF has achieved superior performance in terms of noise suppression and edge preservation, and could have a significant impact on LDCT imaging in the future
Synthesis and Biological Evaluation of Novel Allobetulon/Allobetulin–Nucleoside Conjugates as AntitumorAgents
Allobetulin is structurally similar tobetulinic acid, inducing the apoptosis of cancer cells with low toxicity. However, both of them exhibited weak antiproliferation against several tumor cell lines. Therefore, the new series of allobetulon/allobetulin–nucleoside conjugates 9a–10i were designed and synthesized for potency improvement. Compounds 9b, 9e, 10a, and 10d showed promising antiproliferative activity toward six tested cell lines, compared to zidovudine, cisplatin, and oxaliplatin based on their antitumor activity results. Among them, compound 10d exhibited much more potent antiproliferative activity against SMMC-7721, HepG2, MNK-45, SW620, and A549 human cancer cell lines than cisplatin and oxaliplatin. In the preliminary study for the mechanism of action, compound 10d induced cell apoptosis and autophagy in SMMC cells, resulting in antiproliferation and G0/G1 cell cycle arrest by regulating protein expression levels of Bax, Bcl-2, and LC3. Consequently, the nucleoside-conjugated allobetulin (10d) evidenced that nucleoside substitution was a viable strategy to improve allobetulin/allobetulon’s antitumor activity based on our present study
Correlation between EGFR mutation status and F18âfluorodeoxyglucose positron emission tomographyâcomputed tomography image features in lung adenocarcinoma
Background The purpose of this study was to investigate an association between EGFR mutation status and 18Fâfluorodeoxyglucose positron emission tomographyâcomputed tomography (18FâFDG PETâCT) image features in lung adenocarcinoma. Methods Retrospective analysis of the data of 139 patients with lung adenocarcinoma confirmed by surgical pathology who underwent preoperative 18FâFDG PETâCT was conducted. Correlations between EGFR mutation status, clinical characteristics, and PETâCT parameters, including the maximum standardized uptake value (SUVmax), the mean of the SUV (SUVmean), the peak of the SUV (SUVpeak) of the primary tumor, and the ratio of SUVmax between the primary tumor and the mediastinal blood pool (SUVratio), were statistically analyzed. Multivariate logistic regression analysis was performed to identify predictors of EGFR mutation. Receiver operating characteristic curves of statistical quantitative parameters were compared. Results EGFR mutations were detected in 74 (53.2%) of the 139 lung adenocarcinomas and were more frequent in nonâsmoking patients. Univariate analysis showed that the SUVmax, SUVmean, SUVpeak, and SUVratio were lower in EGFRâmutated than in wildâtype tumors. The receiver operating characteristic curves showed no significant differences between their diagnostic efficiencies. Multivariate logistic regression analysis showed that being a never smoker was an independent predictor of EGFR mutation. Conclusion Quantitative parameters based on 18FâFDG PETâCT have modest power to predict the presence of EGFR mutation in lung adenocarcinoma; however, when compared to smoking history, they are not good or significant predictive factors