Analysis of Toe Formation in Stress-Concentration Zones on High Rock Slopes

Ke Deng,Ming Chen,Peng Yan,Zhendong Leng,Guangdong Yang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

Toe formation is a phenomenon resulting from unconnected cracks between blastholes,which occurred during blasting excavation of the abutment slot at Baihetan hydropower station. Analysis of crack development has tended not to focus on the high in-situ stress environment at the slope corner. Therefore, this study aimed to explore the toe formation process through theoretical analysis and numerical simulation. Firstly, a three-blasthole model was established to analyze the effects of blasting load and in-situ stress on crack extension. Then, a finite-element model of the abutment slot was built to simulate crack propagationunder different in-situ stress environment. Finally, optimization measures for avoiding toe were proposed. The results demonstrate that cracks grow preferentially in the direction of the maximum tangential tensile stress and are influenced by the blasting load and in-situ stress. On the lateral side of the abutment slot, the crack initiation and extension occur far from the centerline due to the deviation of the maximum tangential tensile stress. The deviation increased as the in-situ stress. Consequently, cracks between blastholes not being able to connect with each other results in toe formation. Increment of the linear density of the charge and optimization of the excavated profile are both effective in reducing the impact of the stress concentration caused by in-situ stress and preventing toe formation.

Value of Ultrasound Elastography in Assessment of Enlarged Cervical Lymph Nodes

Teng, Deng-Ke,Wang, Hui,Lin, Yuan-Qiang,Sui, Guo-Qing,Guo, Feng,Sun, Li-Na Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Background: To investigate the value of ultrasound elastography (UE) in the differentiation between benign and malignant enlarged cervical lymph nodes (LNs). Methods: B-mode ultrasound, power Doppler imaging and UE were examined to determine LN characteristics. Two kinds of methods, 4 scores of elastographic classification and a strain ratio (SR) were used to evaluate the ultrasound elastograms. Results: The cutoff point of SR had high utility in differential diagnosis of benign and malignant of cervical lymph nodes, with good sensitivity, specificity and accuracy. Conclusion: UE is an important aid in differential diagnosis of benign and malignant cervical LNs.

Experimental Investigation on Energy Mechanism of Freezing-Thawing Treated Sandstone under Uniaxial Static Compression

Hongwei Deng,Songtao Yu,Junren Deng,Bo Ke,Feng Bin 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.5

To gain a further understanding of Freeze-Thaw weathering effect on the damage of sandstone from the perspective of energy analysis, uniaxial static compression tests were conducted on sandstone samples that suffered 0, 20, 60, 100 and 140 freezingthawing cycles. Then total input strain energy, releasable elastic strain energy, dissipated energy and freezing-thawing induced damage of samples under uniaxial static compression tests were calculated and analyzed. In the mean time, the energy absorption of sandstone under dynamic loading tests (SHPB (Split-Hopkinson pressure bar) experiments) were cited and made a contrast with the dissipated energy of samples under uniaxial static compression tests. The results show that the tangent modulus, total input strain energy, releasable elastic strain energy and dissipated energy of samples decrease with Freezing-Thawing cycles go on, while the freezing-thawing induced damage grow with freezing-thawing cycles increase. In term of energy used for destroying rock samples in different test modes, less energy is needed for destroying samples in uniaxial static compression tests and it decreases with F-T cycles increase, while more energy is needed for destroying samples in dynamic impact loading and it increases with F-T cycles increase. In addition, the number of fragments of broken sample increase with the F-T cycles both in uniaxial static compression tests and dynamic loading tests, and sample under dynamic loading tests is more broken than sample under uniaxial static compression tests.

Meta-analysis of the CYP1A2 -163C>A Polymorphism and Lung Cancer Risk

Deng, Sheng-Qiong,Zeng, Xian-Tao,Wang, Yun,Ke, Qing,Xu, Qiong-Li Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Many published studies have concerned associations between the CYP1A2 -163 C>A polymorphism and risk of lung cancer, but the results have been inconsistent. Therefore, we performed a meta-analysis to obtain a more precise estimate. We searched the PubMed database up to March 1, 2013 for relevant cohort and case-control studies. Supplementary search was conducted manually by searching the references of the included studies and relevant meta-analyses. A meta-analysis was performed using RevMan 5.2 software for calculation of pooled odds ratios (ORs) and relevant 95% confidence intervals (CIs) after data extraction. Finally, seven case-control studies and one nested case-control study involving 1,675 lung cancer patients and 2,393 controls were included. The meta-analysis showed that there was no association of CYP1A2 -163 C>A polymorphism with risk of lung cancer overall [(OR=0.89, 95%CI= 0.74-1.07) for C vs. A; (OR=0.73, 95%CI= 0.50-1.07) for AA vs. CC ; (OR=0.82, 95%CI= 0.62-1.09) for AC vs. CC; (OR=0.79, 95%CI= 0.58-1.07) for (AC+AA) vs. CC; and (OR=0.87, 95%CI= 0.67-1.13) for AA vs. (CC+AC)]. Subgroup analysis indicated that there was an associationbetween CYP1A2 -163C>A polymorphism and lung cancer risk for population-based controls, a trend risk for SCCL (squamous cell carcinoma of lung) and Caucasians. These results suggested that -163 C>A polymorphism is likely to be associated with risk of lung cancer compared with population-based controls.

Study on wall pressure and hysteresis behaviors of a novel dual-bell nozzle

Ke Xin Wu,Gerald Canaan Sohn,Ruoyu Deng,Hao Jia,Heuy Dong Kim,Xianghui Su 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.9

The dual-bell nozzle is a kind of altitude adaptive nozzle for improving the performance of space launchers as well as future reusable launch vehicles. Numerical investigations have been conducted on a planar dual-bell nozzle to illustrate the flow characteristics at sea level, “sneak” transition, and altitude modes, respectively. Findings from computational fluid dynamics have been contrasted with experimental data from the open literature. The normalized pressure distributions along the dual-bell nozzle wall for different turbulence models are compared to the pressure measurements taken during the experiment by fixing the nozzle pressure ratio (NPR) at 29.8. The NPR value gradually rises across a large range from 6 to 55 to explore the evolution of the flow characteristics. The pressure distributions along the nozzle wall and shock position have been investigated. The hysteretic behaviors occur in dual-bell nozzles close to the contour inflection. The wall pressure and hysteresis behaviors have been expounded in detail.

Stress-induced expression of the sweetpotato gene <i>IbLEA14</i> in poplar confers enhanced tolerance to multiple abiotic stresses

Ke, Qingbo,Park, Sung-Chul,Ji, Chang Yoon,Kim, Ho Soo,Wang, Zhi,Wang, Shiwen,Li, Hongbing,Xu, Bingcheng,Deng, Xiping,Kwak, Sang-Soo Elsevier 2018 Environmental and experimental botany Vol.156 No.-

<P><B>Abstract</B></P> <P>Late embryogenesis abundant (LEA) proteins are small, highly hydrophilic proteins that act as protectors of macromolecules and increase abiotic stress tolerance in plants. We previously reported that overexpressing sweetpotato <I>IbLEA14</I> under the control of the <I>CaMV 35S</I> promoter increased osmotic and salt stress tolerance in transgenic sweetpotato calli. In this study, we generated transgenic poplar plants (<I>Populus alba × P. glandulosa</I>) expressing <I>IbLEA14</I> under the control of the oxidative stress-inducible <I>SWPA2</I> promoter (referred to as SL plants). Among the 15 SL plants obtained, three lines (SL2, SL7, and SL12) were established based on <I>IbLEA14</I> transcript levels, tolerance to salt stress and Southern blot analysis. The SL plants exhibited less damage in response to methyl viologen-mediated oxidative stress than non-transgenic (NT) plants. SL plants also showed enhanced tolerance to drought, salt, and heat stress, which was associated with higher photosystem II efficiency and lower malondialdehyde levels compared with NT plants. Furthermore, SL plants had higher levels of monolignol biosynthesis-related gene transcripts under drought stress compared with NT plants. Finally, SL plants exhibited increased tolerance to heat stress, which is associated with the high thermostability of IbLEA14 protein. SL plants might be useful for reforestation on global marginal lands, including desertification and reclaimed areas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>IbLEA14</I> gene was transformed into poplar plants. </LI> <LI> Transgenic poplars exhibit increased tolerance to MV-mediated oxidative, drought, salt and heat stress. </LI> <LI> Overproduction of IbLEA14 affects lignification and thermostability of transgenic poplars. </LI> </UL> </P>

REPRESENTATIONS OF THE MOORE-PENROSE INVERSE OF 2×2 BLOCK OPERATOR VALUED MATRICES

Deng, Chun Yuan,Du, Hong Ke Korean Mathematical Society 2009 대한수학회지 Vol.46 No.6

We obtain necessary and sufficient conditions for $2{\tims}2$ block operator valued matrices to be Moore-Penrose (MP) invertible and give new representations of such MP inverses in terms of the individual blocks.

Down‐regulation of <i>GIGANTEA</i> ‐ <i>like</i> genes increases plant growth and salt stress tolerance in poplar

Ke, Qingbo,Kim, Ho Soo,Wang, Zhi,Ji, Chang Yoon,Jeong, Jae Cheol,Lee, Haeng‐,Soon,Choi, Young‐,Im,Xu, Bingcheng,Deng, Xiping,Yun, Dae‐,Jin,Kwak, Sang‐,Soo John Wiley and Sons Inc. 2017 Plant biotechnology journal Vol.15 No.3

<P><B>Summary</B></P><P>The flowering time regulator GIGANTEA (GI) connects networks involved in developmental stage transitions and environmental stress responses in <I>Arabidopsis</I>. However, little is known about the role of GI in growth, development and responses to environmental challenges in the perennial plant poplar. Here, we identified and functionally characterized three <I>GI‐like</I> genes (<I>PagGIa</I>,<I> PagGIb</I> and <I>PagGIc)</I> from poplar (<I>Populus alba × Populus glandulosa</I>). <I>PagGIs</I> are predominantly nuclear localized and their transcripts are rhythmically expressed, with a peak around zeitgeber time 12 under long‐day conditions. Overexpressing <I>PagGIs</I> in wild‐type (WT) <I>Arabidopsis</I> induced early flowering and salt sensitivity, while overexpressing <I>PagGIs</I> in the <I>gi‐2</I> mutant completely or partially rescued its delayed flowering and enhanced salt tolerance phenotypes. Furthermore, the PagGIs‐PagSOS2 complexes inhibited PagSOS2‐regulated phosphorylation of PagSOS1 in the absence of stress, whereas these inhibitions were eliminated due to the degradation of PagGIs under salt stress. Down‐regulation of <I>PagGIs</I> by RNA interference led to vigorous growth, higher biomass and enhanced salt stress tolerance in transgenic poplar plants. Taken together, these results indicate that several functions of <I>Arabidopsis GI</I> are conserved in its poplar orthologues, and they lay the foundation for developing new approaches to producing salt‐tolerant trees for sustainable development on marginal lands worldwide.</P>

MiR-214 Regulates the Human Hair Follicle Stem Cell Proliferation and Differentiation by Targeting EZH2 and Wnt/b- Catenin Signaling Way In Vitro

Ke-Tao Du,Jia-Qin Deng,Xu-Guang He,Zhao-ping Liu,Cheng Peng,Mingsheng Zhang 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.3

miR-214 plays a major role in the self-renewal of skin tissue. However, whether miR-214 regulates the proliferation and differentiation of human hair follicle stem cells (HFSCs) is unknown. Primary HFSCs were isolated from human scalp skin tissue, cultured, and identified using flow cytometry. An miR-214 mimic and inhibitor were constructed for transfection into HFSCs. The MTS and colony formation assays examined cell proliferation. Immunofluorescence detected the localization and expression levels of TCF4, b-catenin, and differentiation markers. Luciferase reporter and TOP/FOP Flash assays investigated whether miR-214 targeted EZH2 and regulated the Wnt/b-catenin signaling pathway. Western blot determined the expression levels of enhancer of zeste homolog 2 (EZH2), Wnt/b-catenin signaling-related proteins, and HFSC differentiation markers in cells subjected to miR-214 transfection. miR-214 expression was remarkably decreased during the proliferation and differentiation of HFSCs into transit-amplifying (TA) cells. Downregulation of miR- 214 promotes the proliferation and differentiation of HFSCs. Overexpression of miR-214 led to decreased expression of EZH2, b-catenin, and TCF-4, whereas downregulation of miR-214 resulted in increased expression of EZH2, b-catenin, and TCF-4 as well as TA differentiation markers. Immunofluorescence assay revealed that inhibiting miR-214 triggered the entry of b-catenin and TCF-4 into the nucleus. The luciferase reporter and TOP/FOP Flash assays demonstrated that miR- 214 directly targets EZH2 and affects Wnt/b-catenin signaling. The miR-214/EZH2/b-catenin axis could be considered a candidate target in tissue engineering and regenerative medicine for HFSCs.

Mortality of Major Cancers in Guangxi, China: Sex, Age and Geographical Differences from 1971 and 2005

Deng, Wei,Long, Long,Li, Ji-Lin,Zheng, Dan,Yu, Jia-Hua,Zhang, Chun-Yan,Li, Ke-Zhi,Liu, Hai-Zhou,Huang, Tian-Ren Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

The incidence and mortality rates of liver and nasopharyngeal cancer in Guangxi province of China have always been among the highest in the world, and cancer is one of the major diseases that pose a threat to the health of residents in Guangxi. However, no systematic study has been performed to evaluate the time trends in the structure of cancer-related deaths and cancer mortality. In this study, we reveal sex, age and geography differences of cancers mortality between three death surveys (1971 to 1973, 1990 to 1992, and 2004 to 2005). The results show that the standardized mortality rate of cancer in Guangxi residents has risen from 43.3/100,000 to 84.2/100,000, the share of cancer deaths in all-cause deaths has increased from 13.3% to 20.7%, and cancer has become the second most common cause of death. The five major cancers, liver cancer, lung cancer, gastric cancer, nasopharyngeal cancer and colorectal cancer, account for 60% of all the cancer deaths. Cancers with growing mortality rates over the past 30 years include lung cancer, colorectal cancer, liver cancer and female breast cancer, of which lung cancer is associated with the sharpest rise in mortality, with a more than 600% rise in both men and women. Cancer death in Guangxi residents occurs mainly in the elderly population above 45 years of age, especially in people over the age of 65. The areas with the highest mortality rates for liver cancer and nasopharyngeal cancer, which feature regional high incidences, include Chongzuo and Wuzhou. Therefore, for major cancers such as liver cancer, lung cancer, gastric cancer, nasopharyngeal cancer and female breast cancer in Guangxi, we can select high-risk age groups as the target population for cancer prevention and control efforts in high-prevalence areas in a bid to achieve the ultimate goal of lowering cancer mortality in Guangxi.