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Proposed test of the gravitational Inverse-Square-Law at submillimeter scale using torsion pendulum
Zhong-Kun Hu,Jun Luo,Bang-Ming GU 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1
Motivated by extra dimensional theories that predict new eects, experimental search for the deviation from Newtonian gravitational Inverse-Square Law (ISL) was proposed. We are testing the ISL at the separation of about 0.1 mm by means of a torsion pendulum with the at plate shape test and source masses. Electrostatic feedback force keeps the torsion pendulum in its rest position and the current force sensitivity is about 10က15 N.
Progress in determining the gravitational constant G with four attracting masses
Zhong-Kun Hu,Jun Luo 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1
The uncertainty in determining the positions and the geometries of the attracting and the attracted masses is one of the most important error sources in the gravitational experiment. A conguration with the four attracting masses in the determination of Newtonian gravitational constant G by the time-of-swing method is performed. The current problem is that the uncertainty in the period of the torsion pendulum is too large.
Improved photocatalytic performance of Pd-doped ZnO
Jun bo Zhong,Jian zhang Li,Xi yang He,Jun Zeng,Yan Lu,Wei Hu,Kun Lin 한국물리학회 2012 Current Applied Physics Vol.12 No.3
ZnO and Pd-doped ZnO photocatalysts with different molar ratio of Pd/Zn (1/100, 2/100, 3/100 and 4/100) were prepared by a solegel method. The photocatalysts prepared were characterized by BET surface area, X-ray diffraction (XRD), UV/vis diffuse reflectance (DRS) and surface photovoltage spectroscopy (SPS), respectively. The results show that doping Pd into ZnO decreases the BET surface area. The XRD spectra of the Pd-doped ZnO catalysts calcined at 773 K show only the characteristic peaks of wurtzite-type. Doping Pd into ZnO increases the absorbance of ZnO in visible region and enhances the photoinduced charge separation rate. The photocatalytic activity of Pd-doped ZnO photocatalysts for decolorization of methyl orange (MO) solution was evaluated, of all the photocatalysts prepared, the Pddoped ZnO with 3/100 possesses the best photocatalytic activity. The results of further experiments show that increased adsorption ability of light and high separation rate of photoinduced charge carriers all play an important role in promotion of photocatalytic activity of Pd-doped ZnO nanostructure.
Song, Qing-Kun,Li, Jing,Huang, Rong,Fan, Jin-Hu,Zheng, Rong-Shou,Zhang, Bao-Ning,Zhang, Bin,Tang, Zhong-Hua,Xie, Xiao-Ming,Yang, Hong-Jian,He, Jian-Jun,Li, Hui,Li, Jia-Yuan,Qiao, You-Lin,Chen, Wan-Qin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22
Background: The study aimed to describe the age distribution of breast cancer diagnosis among Chinese females for comparison with the United States and the European Union, and provide evidence for the screening target population in China. Materials and Methods: Median age was estimated from hospital databases from 7 tertiary hospitals in China. Population-based data in China, United States and European Union was extracted from the National Central Cancer Registry, SEER program and GLOBOCAN 2008, respectively. Age-standardized distribution of breast cancer at diagnosis in the 3 areas was estimated based on the World Standard Population 2000. Results: The median age of breast cancer at diagnosis was around 50 in China, nearly 10 years earlier than United States and European Union. The diagnosis age in China did not vary between subgroups of calendar year, region and pathological characteristics. With adjustment for population structure, median age of breast cancer at diagnosis was 50~54 in China, but 55~59 in United States and European Union. Conclusions: The median diagnosis age of female breast cancer is much earlier in China than in the United States and the European Union pointing to racial differences in genetics and lifestyle. Screening programs should start at an earlier age for Chinese women and age disparities between Chinese and Western women warrant further studies.
( Xue Feng Han ),( Bo Kun Lin ),( Gan Ji Ru ),( Zhi Biao Zhang ),( Yan Liu ),( Zhong Hu ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.2
Enteromorpha polysaccharides (EP) extracted from green algae have displayed a wide variety of biological activities. However, their high molecular weight leads to a high viscosity and low solubility, and therefore, greatly restrains their application. To solve this problem, bacteria from the surface of Enteromorpha were screened, and an Alteromonas macleodii strain B7 was found to be able to decrease the molecular weight of EP in culture media. Proteins harvested from the supernatant of the A. macleodii B7 culture were subjected to native gel electrophoresis, and a band corresponding to the Enteromorpha polysaccharide lyase (EPL) was detected by activity staining. The enzyme identity was subsequently confirmed by MALDI-TOF/TOF mass spectrometry as the putative α-amylase reported in A. macleodii ATCC 27126. The amylase gene (amySTU) from A. macleodii B7 was cloned into Escherichia coli, resulting in highlevel expression of the recombinant enzyme with EP-degrading activity. AmySTU was found to be cold-adapted; however, its optimal enzyme activity was detected at 40oC. The α-amylase was highly stable over a broad pH range (5.5-10) with the optimal pH at 7.5-8.0. The highest enzyme activity was detected when NaCl concentration was 2%, which dropped by 50% when the NaCl concentration was increased to 16%, showing an excellent nature of halotolerance. Furthermore, the amylase activity was not significantly affected by tested surfactants or the presence of some organic solvents. Therefore, the A. macleodii strain B7 and its α-amylase can be useful in lowering EP molecular weight and in starch processing.
( Jia-yi Dou ),( Yu-chen Jiang ),( Zhong-he Hu ),( Kun-chen Yao ),( Ming-hui Yuan ),( Xiao-xue Bao ),( Mei-jie Zhou ),( Yue Liu ),( Zhao-xu Li ),( Li-hua Lian ),( Ji-xing Nan ),( Yan-ling Wu ) 한국응용약물학회 2022 Biomolecules & Therapeutics(구 응용약물학회지) Vol.30 No.3
The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 μM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.