This paper demonstrates capabilities of low-field nuclear magnetic resonance (NMR) and microfocus X-ray computed tomography (μCT) in advanced, nondestructive, and quantitative characterization of pore types, producib...This paper demonstrates capabilities of low-field nuclear magnetic resonance (NMR) and microfocus X-ray computed tomography (μCT) in advanced, nondestructive, and quantitative characterization of pore types, producible porosity, pore structure, and spatial disposition of pore-fractures in coals. Results show that the NMR transverse relaxation time (T2) at 0.5–2.5, 20–50, and 】100 ms correspond to pores of 【0.1 μm, 】0.1 μm, and fractures, respectively. A much higher T2 spectrum peak reflects a much better development of pores (or fractures) corresponding to the T2, and vice versa. Three basic components in coals, i.e., the pores (or fractures), coal matrix, and minerals have their distinctive range of CT numbers. Among these, the CT number of pores is commonly less than 600 HU. The producible porosity, which is a determination of permeability, can be calculated by T2 cutoff value (T2C) of coal NMR. The coal pore structure can be efficiently estimated by the newly proposed "T2C based model". Finally, μCT scan was proven capable of modeling and spatial visualization of pores and fractures.展开更多
The Keap1–Nrf2–ARE pathway is an important antioxidant defense mechanism that protects cells from oxidative stress and the Keap1–Nrf2 protein–protein interaction(PPI) has become an important drug target to upregul...The Keap1–Nrf2–ARE pathway is an important antioxidant defense mechanism that protects cells from oxidative stress and the Keap1–Nrf2 protein–protein interaction(PPI) has become an important drug target to upregulate the expression of ARE-controlled cytoprotective oxidative stress response enzymes in the development of therapeutic and preventive agents for a number of diseases and conditions. However, most known Nrf2 activators/ARE inducers are indirect inhibitors of Keap1–Nrf2PPI and they are electrophilic species that act by modifying the sulfhydryl groups of Keap1's cysteine residues. The electrophilicity of these indirect inhibitors may cause "off-target" side effects by reacting with cysteine residues of other important cellular proteins. Efforts have recently been focused on the development of direct inhibitors of Keap1–Nrf2 PPI. This article reviews these recent research efforts including the development of high throughput screening assays, the discovery of peptide and small molecule direct inhibitors, and the biophysical characterization of the binding of these inhibitors to the target Keap1 Kelch domain protein. These non-covalent direct inhibitors of Keap1–Nrf2 PPI could potentially be developed into effective therapeutic or preventive agents for a variety of diseases and conditions.展开更多
本文回顾了CT技术的发展过程和当前水平,认为CT技术的发展已经步入了低剂量成像时代。并提出在应用CT低剂量技术的时侯应遵守ALARA(As Low As Reassenable Achievable)原则。由于当前CT低剂量技术种类繁多,本文在举例归纳说明的同时,认...本文回顾了CT技术的发展过程和当前水平,认为CT技术的发展已经步入了低剂量成像时代。并提出在应用CT低剂量技术的时侯应遵守ALARA(As Low As Reassenable Achievable)原则。由于当前CT低剂量技术种类繁多,本文在举例归纳说明的同时,认为放射科医生应该树立良好的学习意识以更好地掌握和使用CT低剂量技术。展开更多
Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The eff...Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening.展开更多
基金supported by National Major Research Program for Science and Technology of China (Grant Nos. 2008ZX05034-01 and 2008ZX05062-001)National Basic Research Program of China (Grant No. 2009CB219604)+2 种基金National Natural Science Foundation of China (Grant No. 40972107)Petro China Innovation Foundation (Grant No. 2008D-5006-01-04)Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT0864)
文摘This paper demonstrates capabilities of low-field nuclear magnetic resonance (NMR) and microfocus X-ray computed tomography (μCT) in advanced, nondestructive, and quantitative characterization of pore types, producible porosity, pore structure, and spatial disposition of pore-fractures in coals. Results show that the NMR transverse relaxation time (T2) at 0.5–2.5, 20–50, and 】100 ms correspond to pores of 【0.1 μm, 】0.1 μm, and fractures, respectively. A much higher T2 spectrum peak reflects a much better development of pores (or fractures) corresponding to the T2, and vice versa. Three basic components in coals, i.e., the pores (or fractures), coal matrix, and minerals have their distinctive range of CT numbers. Among these, the CT number of pores is commonly less than 600 HU. The producible porosity, which is a determination of permeability, can be calculated by T2 cutoff value (T2C) of coal NMR. The coal pore structure can be efficiently estimated by the newly proposed "T2C based model". Finally, μCT scan was proven capable of modeling and spatial visualization of pores and fractures.
基金the financial support of Grants CA133791, CA125868, and MH093197 from the National Institutes of Health, United States
文摘The Keap1–Nrf2–ARE pathway is an important antioxidant defense mechanism that protects cells from oxidative stress and the Keap1–Nrf2 protein–protein interaction(PPI) has become an important drug target to upregulate the expression of ARE-controlled cytoprotective oxidative stress response enzymes in the development of therapeutic and preventive agents for a number of diseases and conditions. However, most known Nrf2 activators/ARE inducers are indirect inhibitors of Keap1–Nrf2PPI and they are electrophilic species that act by modifying the sulfhydryl groups of Keap1's cysteine residues. The electrophilicity of these indirect inhibitors may cause "off-target" side effects by reacting with cysteine residues of other important cellular proteins. Efforts have recently been focused on the development of direct inhibitors of Keap1–Nrf2 PPI. This article reviews these recent research efforts including the development of high throughput screening assays, the discovery of peptide and small molecule direct inhibitors, and the biophysical characterization of the binding of these inhibitors to the target Keap1 Kelch domain protein. These non-covalent direct inhibitors of Keap1–Nrf2 PPI could potentially be developed into effective therapeutic or preventive agents for a variety of diseases and conditions.
文摘本文回顾了CT技术的发展过程和当前水平,认为CT技术的发展已经步入了低剂量成像时代。并提出在应用CT低剂量技术的时侯应遵守ALARA(As Low As Reassenable Achievable)原则。由于当前CT低剂量技术种类繁多,本文在举例归纳说明的同时,认为放射科医生应该树立良好的学习意识以更好地掌握和使用CT低剂量技术。
基金Supported by Grant-in-Aid for H22-Third Term Comprehensive Control Research for Cancer 022 from the Japanese Ministry of Health,Labour and Welfare
文摘Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening.
