60 research outputs found
The rise of foreign banks in China
Since the economy reform, its fragile banking sector may turn out to the single biggest threat to China's macroeconomic stability and long-term growth. Foreign financial investors have been introduced to help Chinese government to reform its financial systems. At the same time,
foreign investors have their own considerations to enter into Chinese market. With the purposes to balance their interests, proper entry approaches and entry strategies will be discusse
Claudin-1/4 as directly target gene of HIF-1α can feedback regulating HIF-1α by PI3K-AKT-mTOR and impact the proliferation of esophageal squamous cell though Rho GTPase and p-JNK pathway
Immunohistochemical microarray comprising 80 patients with esophageal squamous cell carcinoma (ESCC) and discovered that the expression of CLDN1 and CLDN4 were significantly higher in cancer tissues compared to para-cancerous tissues. Furthermore, CLDN4 significantly affected the overall survival of cancer patients. When two ESCC cell lines (TE1, KYSE410) were exposed to hypoxia (0.1% O2), CLDN1/4 was shown to influence the occurrence and development of esophageal cancer. Compared with the control culture group, the cancer cells cultured under hypoxic conditions exhibited obvious changes in CLDN1 and CLDN4 expression at both the mRNA and protein levels. Through genetic intervention and Chip, we found that HIF-1α could directly regulate the expression of CLDN1 and CLDN4 in cancer cells. Hypoxia can affect the proliferation and apoptosis of cancer cells by regulating the PI3K-Akt-mTOR pathway. Molecular analysis further revealed that CLDN1 and CLDN4 can participate in the regulation process and had a feedback regulatory effect on HIF-1α expression in cancer cells. In vitro cellular experiments and vivo experiments in nude mice further revealed that changes in CLDN4 expression in cancer cells could affect the proliferation of cancer cells via regulation of Rho GTP and p-JNK pathway. Whether CLDN4 can be target for the treatment of ESCC needs further research
Abundant copy-number loss of CYCLOPS and STOP genes in gastric adenocarcinoma
Background
Gastric cancer, a leading cause of cancer death worldwide, has been little studied compared with other cancers that impose similar health burdens. Our goal is to assess genomic copy-number loss and the possible functional consequences and therapeutic implications thereof across a large series of gastric adenocarcinomas.
Methods
We used high-density single-nucleotide polymorphism microarrays to determine patterns of copy-number loss and allelic imbalance in 74 gastric adenocarcinomas. We investigated whether suppressor of tumorigenesis and/or proliferation (STOP) genes are associated with genomic copy-number loss. We also analyzed the extent to which copy-number loss affects Copy-number alterations Yielding Cancer Liabilities Owing to Partial losS (CYCLOPS) genes–genes that may be attractive targets for therapeutic inhibition when partially deleted.
Results
The proportion of the genome subject to copy-number loss varies considerably from tumor to tumor, with a median of 5.5 %, and a mean of 12 % (range 0–58.5 %). On average, 91 STOP genes were subject to copy-number loss per tumor (median 35, range 0–452), and STOP genes tended to have lower copy-number compared with the rest of the genes. Furthermore, on average, 1.6 CYCLOPS genes per tumor were both subject to copy-number loss and downregulated, and 51.4 % of the tumors had at least one such gene.
Conclusions
The enrichment of STOP genes in regions of copy-number loss indicates that their deletion may contribute to gastric carcinogenesis. Furthermore, the presence of several deleted and downregulated CYCLOPS genes in some tumors suggests potential therapeutic targets in these tumors.Singapore. Ministry of Health (Duke-NUS Signature Research Programs)Singapore. Agency for Science, Technology and ResearchSingapore-MIT Allianc
Gas adsorption properties of ZSM-5 zeolites heated to extreme temperatures
Zeolites are broadly useful catalysts and molecular sieve adsorbents for purification. In this work the thermal degradations of bare and platinum-loaded ZSM-5 was studied with the goal of understanding the behavior of nanoporous solids at extreme temperatures comparable to those present in nuclear fuels. Zeolites were heated in air and nitrogen at temperatures up to 1500 °C, and then characterized for thermal stability via X-ray diffraction (XRD) and for gas adsorption by the Brunauer-Emmett-Teller (BET) method. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were also employed. These results indicate zeolites are stable when heat-treated up to 800 °C and degrade slowly at higher temperatures. However, significant surface area degradation begins at 1025–1150 °C with an activation energy of 400 kJ/mole. At 1500 °C, gas adsorption measurements and SEM images show complete collapse of the porous structure. Critically for nuclear fuel applications, however, the zeolites still adsorb helium in significant quantities
Response to Extreme Temperatures of Mesoporous Silica MCM-41: Porous Structure Transformation Simulation and Modification of Gas Adsorption Properties
The rise of foreign banks in China
Since the economy reform, its fragile banking sector may turn out to the single biggest threat to China's macroeconomic stability and long-term growth. Foreign financial investors have been introduced to help Chinese government to reform its financial systems. At the same time,
foreign investors have their own considerations to enter into Chinese market. With the purposes to balance their interests, proper entry approaches and entry strategies will be discusse
Atomistic modeling of La 3+ doping segregation effect on nanocrystalline yttria-stabilized zirconia
Computational Study of Materials Interface Properties for Applications at Extreme Conditions: Mesoporous Silica and Yttria Stabilized Zirconia
Materials interface properties bring both opportunities and challenges for materials design. Especially for applications at extreme conditions, the metastable nature of interface inevitably leads to the big question of structural stability. In this thesis, the nanopore surface in mesoporous MCM-41 and the grain boundaries in nanocrystalline yttria-stabilized zirconia (YSZ) were selected as the two presentative interface types. They were studied with atomistic simulation methods to help understand and improve their structure stability at different conditions, and other related properties for relevant applications. For MCM-41, its thermostability and pore structure transformation mechanisms subjected to temperatures from 300 K up to 2885 K was studied by the combination of molecular dynamics (MD) and Monte Carlo simulations. Silica was experimentally characterized to inform the models and enable prediction of changes in gas adsorption/separation properties. MD simulations suggest that the pore closure process is activated by a collective diffusion of matrix atoms into the porous region, accompanied by bond reformation at the surface. Degradation is kinetically limited, such that complete pore closure is postponed at high heating rates. Applying the Kissinger equation, a strong correlation between the simulated pore collapse temperatures and the experimental values was found, which implies an activation energy of 416 ± 17 kJ/mol for pore closure. MC simulations give the adsorption and selectivity for thermally treated MCM-41, for N 2, Ar, Kr and Xe at room temperature within the 1–10000 kPa pressure range. Relative to pristine MCM-41, it was observed that increased surface roughness due to decreasing pore size amplifies the difference of the absolute adsorption amount differently for different adsorbate molecules. In particular, it was found that adsorption of strongly-interacting molecules can be enhanced in the low-pressure region while adsorption of weakly-interacting molecules is inhibited. This then results in higher selectivity in binary mixture adsorption in mesoporous silica. For YSZ, the stabilization effect of La3+ doping on the grain boundary structure of YSZ was studied using MC simulation. It reveals the segregation of La3+ at eight tilt grain boundary (GB) structures and predicted an average grain boundary (GB) energy decrease of 0.25 J/m 2, which is close to experimental values reported in the literature. Cation stabilization was found to be the main reason for the GB energy decrease, and energy fluctuations near the grain boundary are smoothed out with La 3+ segregation. Then the segregation effect on materials ionic conductivity was studied with MD simulation. Both dynamic and energetic analysis on Σ13 (510)/[001] GB structure revealed La3+ doping hinders O 2– diffusion in the GB region, where the diffusion coefficient monotonically decreases with increasing La3+ doping concentration. The effect was attributed to the increase in the site-dependent migration barriers for O2– hopping caused by segregated La3+, which also leads to anisotropic diffusion at the GB
Helium interactions with alumina formed by atomic layer deposition show potential for mitigating problems with excess helium in spent nuclear fuel
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