626 results on '"Heng D"'
Search Results
252. Graduates of northern Ontario family medicine residency programs practise where they train.
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Heng D, Pong RW, Chan BTB, Degani N, Crichton T, Goertzen J, McCready W, and Rourke J
- Abstract
OBJECTIVE: To examine where graduates of the Northeastern Ontario Family Medicine (NOFM) residency program in Sudbury and the Family Medicine North (FMN) program in Thunder Bay practise after graduation, using cross-sectional and longitudinal analyses. METHODS: Data from the Scott's Medical Database were examined. All physicians who graduated from NOFM and FMN between 1993 and 2002 were included in this analysis. Differences in the location of first practice between NOFM and FMN graduates were tested using chi-squared tests. Logistic regression analyses were used to examine the impact of the training program on a physician's first, as well as continuing, practice location. RESULTS: Between 1993 and 2002, FMN graduates were 4.56 times more likely (95% confidence interval [CI] 2.34-8.90) to practise in rural areas, compared with NOFM graduates, but NOFM graduates were 2.50 times more likely than FMN graduates (95% CI 1.35-4.76) to practise in northern Ontario. There was no statistically significant difference between the graduates of the 2 programs in the likelihood of working in either northern Ontario or a rural area. About two-thirds (67.5%) of all person-years of medical practice provided by NOFM and FMN graduates took place in northern Ontario or rural areas outside the north. CONCLUSION: NOFM and FMN have been successful in producing family physicians to work in northern Ontario and rural areas. Results from this study add to the growing evidence from Canada and abroad that rural or northern medical education and training increases the likelihood that the graduates will practise in rural or northern communities. [ABSTRACT FROM AUTHOR]
- Published
- 2007
253. Should central obesity Be an optional or essential component of the metabolic syndrome?: ischemic heart disease risk in the Singapore Cardiovascular Cohort Study.
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Lee J, Ma S, Heng D, Tan C, Chew S, Hughes K, and Tai E
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OBJECTIVE: The International Diabetes Federation (IDF) proposes that central obesity is an 'essential' component of the metabolic syndrome, while the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) proposes that central obesity is an 'optional' component. This study examines the effect of the metabolic syndrome with and without central obesity in an Asian population with ischemic heart disease (IHD). RESEARCH DESIGN AND METHODS: From the population-based cohort study (baseline 1992-1995), 4,334 healthy individuals were grouped by the presence or absence of the metabolic syndrome and central obesity and followed up for an average of 9.6 years by linkage with three national registries. Cox's proportional hazards model was used to obtain adjusted hazard ratios (HRs) for risk of a first IHD event. RESULTS: The prevalence of metabolic syndrome was 17.7% by IDF criteria and 26.2% by AHA/NHLBI criteria using Asian waist circumference cutoff points for central obesity. Asian Indians had higher rates than Chinese and Malays. There were 135 first IHD events. Compared with individuals without metabolic syndrome, those with central obesity/metabolic syndrome and no central obesity/metabolic syndrome were at significantly increased risk of IHD, with adjusted HRs of 2.8 (95% CI 1.8-4.2) and 2.5 (1.5-4.0), respectively. CONCLUSIONS: Having metabolic syndrome either with or without central obesity confers IHD risk. However, having central obesity as an 'optional' rather than 'essential' criterion identifies more individuals at risk of IHD in this Asian cohort. [ABSTRACT FROM AUTHOR]
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- 2007
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254. Lowering the criterion for impaired fasting glucose: impact on disease prevalence and associated risk of diabetes and ischemic heart disease.
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Tai ES, Goh SY, Lee JJM, Wong M, Heng D, Hughes K, Chew SK, Cutter J, Chew W, Gu K, Chia KS, Tan CE, Tai, E Shyong, Goh, Su Yen, Lee, Jeannette J M, Wong, Moh-Sim, Heng, Derrick, Hughes, Kenneth, Chew, Suok Kai, and Cutter, Jeffery
- Abstract
Objective: To determine the effect of lowering the fasting plasma glucose (FPG) criterion for impaired fasting glucose (IFG) on the prevalence of IFG, the risks of diabetes, and cardiovascular disease (CVD) associated with IFG.Research Design and Methods: Three studies were used: 1). the 1998 National Health Survey (NHS98), a randomly selected cross-sectional sample of 4723 subjects; 2). the Singapore Impaired Glucose Tolerance (IGT) Follow-up Study, a cohort study comprising 295 IGT and 292 normal glucose tolerance subjects (frequency matched for age, sex, and ethnic group) followed up from 1992 to 2000; and 3). the Singapore CVD Cohort Study, comprising 5920 subjects from three cross-sectional studies in whom the first ischemic heart disease (IHD) event was identified through linkage to registry databases. Risk of diabetes (Singapore IGT Follow-up study) was estimated using logistic regression adjusted for age, sex, and ethnicity. Risk of IHD (Singapore CVD cohort) was estimated using stratified (by study, from which data were derived) Cox's proportional hazards models adjusted for age, sex, and ethnicity.Results: Lowering the criterion for diagnosing IFG to 5.6 mmol/l increased the prevalence of IFG from 9.5 to 32.3% in the NHS98. The lower cutoff identified more subjects at risk of diabetes and IHD, but the relative risk was lower than that for IGT.Conclusions: Greater efforts to identify those with IGT, or a group at similar risk of diabetes and CVD, may be a more efficient public health measure than lowering the FPG criterion for diagnosing IFG. [ABSTRACT FROM AUTHOR]- Published
- 2004
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255. Electrodeposition of tin on Nafion-bonded carbon black as an active catalyst layer for efficient electroreduction of CO2 to formic acid
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Qinian Wang, Xinqi Wang, Chao Wu, Yuanyuan Cheng, Qingye Sun, Heng Dong, and Hongbing Yu
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Medicine ,Science - Abstract
Abstract Electroreduction of CO2 to formic acid (ERCF) based on gas diffusion electrodes (GDEs) has been considered as a promising method to convert CO2 into value-added chemicals. However, current GDEs for ERCF suffer from low efficiency of electron transfer. In this work, a novel Sn-based gas diffusion electrode (ESGDE) is prepared by electrodepositing Sn on Nafion-bonded carbon black as catalyst layer to enhance electron transfer and thus the efficiency of ERCF. The highest Faraday efficiency (73.01 ± 3.42%), current density (34.21 ± 1.14 mA cm−2) and production rate (1772.81 ± 59.08 μmol m−2 s−1) of formic acid are obtained by using the ESGDE with electrodeposition time of 90 s in 0.5 M KHCO3 solution, which are one of the highest values obtained from Sn-based gas diffusion electrodes under similar conditions. The notable efficiency of ERCF achieved here should be attributed to the enhancement in the reactants transfer as well as the three-dimensional reaction zone. This work will be helpful for the industrial application of GDEs in EFCF.
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- 2017
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256. Loss of succinyl-CoA synthase ADP-forming β subunit disrupts mtDNA stability and mitochondrial dynamics in neurons
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Yujun Zhao, Jing Tian, Shaomei Sui, Xiaodong Yuan, Hao Chen, Chuanqiang Qu, Yifeng Du, Lan Guo, and Heng Du
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Medicine ,Science - Abstract
Abstract Succinyl Coenzyme A synthetase (SCS) is a key mitochondrial enzyme. Defected SCS ADP-forming β subunit (SCS A-β) is linked to lethal infantile Leigh or leigh-like syndrome. However, the impacts of SCS A-β deficiency on mitochondria specifically in neurons have not yet been comprehensively investigated. Here, by down-regulating the expression levels of SCS A-β in cultured mouse neurons, we have found that SCS A-β deficiency induces severe mitochondrial dysfunction including lowered oxidative phosphorylation (OXPHOS) efficiency, increased mitochondrial superoxide production, and mtDNA depletion as well as aberrations of mitochondrial fusion and fission proteins, which eventually leads to neuronal stress. Our data also suggest that the deregulation of mitochondrial nucleoside diphosphate kinase (NDPK) together with defects in mitochondrial transcription factors including mitochondrial DNA pol γ and Twinkle contribute to SCS A-β deficiency-mediated mtDNA instability. Furthermore, we have found that SCS A-β deficiency has detrimental influence on neuronal mitochondrial dynamics. Put together, the results have furnished our knowledge on the pathogenesis of SCS A-β deficiency-related mitochondrial diseases and revealed the vital role of SCS A-β in maintaining neuronal mitochondrial quality control and neuronal physiology.
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- 2017
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257. Body surface area is a novel predictor for surgical complications following video-assisted thoracoscopic surgery for lung adenocarcinoma: a retrospective cohort study
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Shuangjiang Li, Kun Zhou, Heng Du, Cheng Shen, Yongjiang Li, and Guowei Che
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Body surface area ,Video-assisted thoracoscopic surgery ,Complications ,Prediction ,Surgery ,RD1-811 - Abstract
Abstract Background Body surface area (BSA) is a biometric unit to measure the body size. Its clinical significance in video-assisted thoracoscopic surgery (VATS) was rarely understood. We aimed to estimate the predictive value of BSA for surgical complications following VATS anatomical resections for lung adenocarcinoma (LAC). Methods A single-center retrospective analysis was performed on the consecutive patients between July 2014 and January 2016 in our institution. The differences in mean BSA values were evaluated between groups of patients classified by the development of postoperative surgical complications (PSCs), overall morbidity and cardiopulmonary complications, respectively. Receiver operating characteristic (ROC) analysis was performed to determine a threshold value of BSA on prediction of PSC occurrence. A multivariate logistic-regression model involving this optimal cut-off value and other significant parameters was established to identify the predictors for PSCs. Results During the study period, a total of 442 patients undergoing VATS anatomical resections for LAC were enrolled in this study. There were 135 patients developed with one or more complications (rate = 30.5%). PSCs occupied the largest percentages of all these complications (n = 81, rate = 18.3%). The mean BSA in PSC group was significantly higher than that in non-PSC group (1.76 ± 0.15 m2 vs 1.71 ± 0.16 m2; P = 0.016). No difference was found in mean BSA values between groups classified by any other complication. The ROC analysis determined a BSA value of 1.68 m2 to be the threshold value with the maximum joint sensitivity of 72.8% and specificity of 48.5%. Compared to patients with BSA ≤ 1.68 m2, patients with BSA > 1.68 m2 had significantly higher incidences of prolonged air leak (P = 0.006) and chylothorax (P = 0.004). Further multivariate logistic-regression analysis indicated that BSA > 1.68 m2 could be an independent risk factor for PSCs (odds ratio: 2.03; P = 0.025). Conclusions BSA is an excellent categorical predictor for surgical complications following VATS anatomical resections for LAC. It may be considered when informing patients about surgical risks and selecting cases in the early learning curve. Large-scale and multi-institutional studies are expected to confirm and modify our findings in the future.
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- 2017
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258. Is electrical storm in ICD patients the sign of a dying heart?
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Greene, M., Newman, D., Geist, M., Paquette, M., Heng, D., and Dorian, P.
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Background Electrical storm in patients with implanted cardioverter defibrillators (ICDs) is purported to carry an ominous prognosis. Methods and Results We retrospectively compared 40 patients with electrical storm (defined as three or more episodes of ventricular arrhythmia requiring ICD therapy in a 24 h period) with those only having isolated appropriate ICD therapy (n=57) and with patients having no or only inappropriate ICD therapy (n=125). All patients received ICDs for documented sustained VT or VF. There was no significant difference in age, sex, ejection fraction, total follow-up time, or underlying heart disease between any of the three groups. Patients who had electrical storm received their first appropriate ICD therapy 275±369 days post-implant (35% had storm as their first event) with storm occurring an average of 599±710 days post-implant. Patients had 1·5±1·0 storms in total (median=1), with 55±91 episodes per storm. There were no significant differences in actuarial survival at 5-year follow-up between the three groups. Eighty percent of storm patients were alive 5 years post-implant. Conclusion Storm is a common occurrence in ICD patients, can occur at any time during the follow-up period, and does not independently confer increased mortality. [ABSTRACT FROM PUBLISHER]
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- 2000
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259. Genetic polymorphisms analysis of pharmacogenomic VIP variants in Bai ethnic group from China
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Wanlu Chen, Heng Ding, Yujing Cheng, Qi Li, Run Dai, Xin Yang, and Chan Zhang
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bai ethnic group ,genetic polymorphisms ,individualized medicine ,pharmacogenomics ,VIP variants ,Genetics ,QH426-470 - Abstract
Abstract Background The pharmacogenomics study has been widely used for the study of very important pharmacogenetic (VIP) variants among different ethnic groups. However, there is little known about the pharmacogenomics information regarding Bai family. Our study aimed to screen the polymorphism of the VIP gene in Bai nationality. Methods We genotyped 81 VIP variants (selected from the PharmGKB database) in the Bai population and then compared them to the other 11 major HapMap populations by chi‐square test, structure and F‐statistics (Fst) analysis. Results Our results indicated that rs20417 (PTGS2), rs4148323 (UGT1A), and rs1131596 (SLC19A1) were most different in Bai compared with most of the 11 populations from the HapMap data set. Furthermore, population structure and F‐statistics (Fst) analysis also demonstrated that the Bai population has the closest genetic relationship with Han Chinese in Beijing, China (CHB), followed by Japanese in Tokyo, Japan (JPT), and the farthest population from the Yoruba in Ibadan, Nigeria (YRI). Conclusions Our study not only presented the genotype frequency difference between the selected population of the Bai population and the other 11 populations, but also showed that the Bai population is most similar to the CHB populations, followed by JPT. These findings would contribute to the development of individualized medicine for the Bai population.
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- 2019
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260. Transcription Factors Sp8 and Sp9 Regulate Medial Ganglionic Eminence-Derived Cortical Interneuron Migration
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Guangxu Tao, Zhenmeiyu Li, Yan Wen, Xiaolei Song, Song Wei, Heng Du, Zhengang Yang, Zhejun Xu, and Yan You
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Sp8 ,Sp9 ,medial ganglionic eminence ,cortical interneuron ,tangential migration ,parvalbumin ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Cortical interneurons are derived from the subpallium and reach the developing cortex through long tangential migration. Mature cortical interneurons are characterized by remarkable morphological, molecular, and functional diversity. The calcium-binding protein parvalbumin (PV) and neuropeptide somatostatin (SST) identify most medial ganglionic eminence (MGE)-derived cortical interneurons. Previously, we demonstrated that Sp9 plays a curial transcriptional role in regulating MGE-derived cortical interneuron development. Here, we show that SP8 protein is weekly expressed in the MGE mantle zone of wild type mice but upregulated in Sp9 null mutants. PV+ cortical interneurons were severely lost in Sp8/Sp9 double conditional knockouts due to defects in tangential migration compared with Sp9 single mutants, suggesting that Sp8/9 coordinately regulate PV+ cortical interneuron development. We provide evidence that Sp8/Sp9 activity is required for normal MGE-derived cortical interneuron migration, at least in part, through regulating the expression of EphA3, Ppp2r2c, and Rasgef1b.
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- 2019
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261. Strategic Information Sharing in a Dynamic Supply Chain with a Carrier under Complex Uncertainty
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Heng Du and Ye Jiang
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Mathematics ,QA1-939 - Abstract
Whether to use an information sharing mechanism is investigated in a dynamic supply chain, where one manufacturer, one carrier, and one retailer are faced with uncertain yield, demand, and lead time during multiple periods. Each member is modeled as an adaptive agent based on multiagent technique, and their decisions can be adjusted timely to adapt to external environment. There are two choices for the whole supply chain to deal with uncertain risks: information sharing (IS) or no information sharing (NS). Under strategy IS, the information about market demand and the retailer’s inventory can be shared within the supply chain. For each strategy, the effects of yield, demand, and lead time uncertainties on costs of the supply chain and channel members are studied. It is found that (i) it is rewarding for the upstream manufacturer to use a retailer’s shared information under uncertain yield or demand; (ii) however, information sharing (IS) strategy sometimes should be abandoned for other members and the whole supply chain; (iii) counterintuitively, the increase of transportation time uncertainty benefits the retailer.
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- 2019
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262. The Stability Evaluation of Shaft during Drastic Drawdown Dewatering of Alluvium
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Mingze Du, Yanchun Xu, Heng Duan, and Wen Li
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Physics ,QC1-999 - Abstract
The hydrophobicity of the aquifer at the bottom of the porous alluvium will affect the stability of the shaft. According to the changes of water level and the compressive amount of alluvium, we can evaluate the shaft stability and predict the shaft failure. In this work, the simulation model of the auxiliary shaft in the Zhuxianzhuang Coal Mine is generated by using the Nsdc software to evaluate the stability of the shaft during drastic drawdown dewatering. Based on the measured hydrophobic compression ratio in an adjacent coal mine, the compressive amounts of the strata near the main and auxiliary shafts in the Zhuxianzhuang Coal Mine are predicted under the condition of drastic drawdown dewatering, which will be 249.69 mm and 302.75 mm, respectively. It is more likely that the shaft wall may fracture in the 15th day (fourth load level) under the condition of drastic drawdown dewatering. The formation compressive amount near the auxiliary shaft is approximately 320 mm, which is close to the measured predicted value. At the same time, the Fisher discriminant model is established, and it is predicted that the state of the main and auxiliary shafts will be failure under the conditions of drastic drawdown dewatering in the Zhuxianzhuang Coal Mine. Based on the simulating results, the technical means of using the ground grouting for early prevention and control is proposed.
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- 2019
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263. Secondary segmentation extracted algorithm based on image enhancement for intelligent identification systems
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Heng Dong, Ying Jiang, Yaping Fan, Yu Wang, and Guan Gui
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Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Due to the indefinite position of the characters in the invoice and the difference of the color shades, which greatly increases the difficulty of intelligent identification, it is difficult to meet practical applications. In order to solve this problem, this article proposes a quadratic segmentation algorithm based on image enhancement. Specifically, we first enhance the color of the image based on gamma transformation, and then separate the machine-printing character from the blank invoice based on the color analysis of the machine-printing character. Then according to the open operation in the image processing field and the bounding rectangle algorithm, the pixel information of the machine-printing character is obtained, which is convenient for getting the character information. The algorithm can achieve effective extraction of machine-printing characters and also reduce the difficulty of invoice identification and improving the accuracy of invoice identification. Simulation results are given to confirm the proposed algorithm. After many experiments, the extraction accuracy of this algorithm is as high as 95%.
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- 2018
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264. A Comprehensive Study of the Impact of Large-Scale Landscape Pattern Changes on the Watershed Ecosystem
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Hai Liu, Heng Di, Yuefei Huang, Liang Zheng, and Yuan Zhang
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landscape pattern ,water storage ,vegetation ,ecosystem services ,Danjiang Reservoir ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
The South-to-North Water Diversion Project (SNWD) is the world’s largest inter-basin water diversion project, and the Danjiangkou Reservoir is a water source of the middle route project of the SNWD. Dynamic monitoring of ecological environment changes in Danjiangkou Water source area can provide theoretical support for reservoir water storage security and ecosystem protection. In this study, the water storage of Danjiangkou reservoir was estimated and its dynamic change was analyzed. On this basis, the changes of landscape pattern and ecosystem services value caused by the SNWD project were analyzed. The results show that the reservoir storage presented an obvious growth trend from 2000 to 2019, especially after the middle route of the SNWD was opened in 2014. After the implementation of the SNWD project, the vegetation degradation in Danjiangkou reservoir area was obvious, which is mainly related to the expansion of construction land. The ecosystem service value of the Danjiangkou Reservoir was mainly determined by the water conservation supply value and climate regulation value. After the implementation of the SNWD project, the values of water conservation and supply, climate regulation, and hydropower generation showed an increasing trend, while the values of fixing carbon and releasing oxygen, and organic matter production showed a decreasing trend.
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- 2021
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265. Study on the Exploitation Scheme of Groundwater under Well-Canal Conjunctive Irrigation in Seasonally Freezing-Thawing Agricultural Areas
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Yang Yang, Yan Zhu, Wei Mao, Heng Dai, Ming Ye, Jingwei Wu, and Jinzhong Yang
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seasonal freezing-thawing area ,well-canal conjunctive irrigation ,coupled model ,MODFLOW-LGR ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
The suitable groundwater exploitation scheme in freezing-thawing agricultural areas under the well-canal conjunctive irrigation conditions is confronted with two major challenges, which are computationally expensive local grid refinements along wells, and the model suitability problem in the freezing-thawing period. In this study, an empirical method for groundwater level prediction in the freezing-thawing period was developed and integrated with the local grid refinement groundwater model MODFLOW-LGR for the groundwater process prediction. The model was then applied to estimate the suitable groundwater exploitation scheme, including the size of well-irrigated area and the irrigation area of single well. The results showed that suitable size of well-irrigated area should be smaller than 15 × 106 m2, and the recommended irrigation area of single well as 15 × 104 m2 to 19 × 104 m2. The recommended layout parameters of groundwater exploitation were further used to plan the well-canal conjunctive irrigation scheme in Yongji irrigation district located in northern China. This study provides an important pilot example of the conjunctive use of groundwater and surface water in arid irrigation areas with a seasonal freezing-thawing period.
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- 2021
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266. Mitochondrial Permeability Transition: A Pore Intertwines Brain Aging and Alzheimer’s Disease
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Kun Jia and Heng Du
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mitochondrial permeability transition ,brain aging ,Alzheimer’s disease ,Cytology ,QH573-671 - Abstract
Advanced age is the greatest risk factor for aging-related brain disorders including Alzheimer’s disease (AD). However, the detailed mechanisms that mechanistically link aging and AD remain elusive. In recent years, a mitochondrial hypothesis of brain aging and AD has been accentuated. Mitochondrial permeability transition pore (mPTP) is a mitochondrial response to intramitochondrial and intracellular stresses. mPTP overactivation has been implicated in mitochondrial dysfunction in aging and AD brains. This review summarizes the up-to-date progress in the study of mPTP in aging and AD and attempts to establish a link between brain aging and AD from a perspective of mPTP-mediated mitochondrial dysfunction.
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- 2021
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267. TREM2 Mediates Microglial Anti-Inflammatory Activations in Alzheimer’s Disease: Lessons Learned from Transcriptomics
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Feng Xue and Heng Du
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Alzheimer’s disease ,microglia ,transcriptomics ,TREM2/Trem2 ,neuroinflammation ,Cytology ,QH573-671 - Abstract
Alzheimer’s disease (AD) is a lethal neurodegenerative disorder primarily affecting the aged population. The etiopathogenesis of AD, especially that of the sporadic type, remains elusive. The triggering receptor expressed on myeloid cells 2 (TREM2), a member of TREM immunoglobulin superfamily, plays a critical role in microglial physiology. Missense mutations in human TREM2 are determined as genetic risk factors associated with the development of sporadic AD. However, the roles of TREM2 in the pathogenesis of AD are still to be established. In this review, we outlined the influence of Trem2 on balance of pro- and anti-inflammatory microglial activations from a perspective of AD mouse model transcriptomics. On this basis, we further speculated the roles of TREM2 in different stages of AD, which may shed light to the development of TREM2-targeted strategy for the prevention and treatment of this neurodegenerative disorder.
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- 2021
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268. Analysis on Structure of Interacted and Interconnected Micro Grid Based Energy Internet on Pelagic Clustering Islands
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Hou Ting-ting, Chen Zhu, Zou Yu-xin, Heng DingDing Heng, Fang Reng-cun, Lei He, Yang Dong-jun, and Sang Zi-xia
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Environmental sciences ,GE1-350 - Abstract
Compared with the direct access to the main power grid and diesel generators, this paper puts forward the scheme of using electric ships to shuttle between islands to transport electric energy, analyzes the limitations and defects of its application in offshore islands; and then puts forward a comprehensive energy supply system of offshore islands. The comprehensive energy supply system can make full use of the rich renewable energy of the islands, and realize the optimal allocation of the overall resources of the islands. At the same time, the energy supply system can break the isolated development pattern of island power grid and connect the island group power exchange ship. This paper analyzes the connotation and characteristics of the system, puts forward the key technology for building the integrated energy supply system of ocean island group, and gives the design and operation analysis example of power exchange ship.
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- 2021
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269. Deregulation of mitochondrial F1FO-ATP synthase via OSCP in Alzheimer’s disease
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Simon J. Beck, Lan Guo, Aarron Phensy, Jing Tian, Lu Wang, Neha Tandon, Esha Gauba, Lin Lu, Juan M. Pascual, Sven Kroener, and Heng Du
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Science - Abstract
F1FO ATP synthase is a critical enzyme for the maintenance of mitochondrial function. Here the authors demonstrate that loss of the F1FO-ATP synthase subunit OSCP and the interaction of OSCP with Aβ peptide in Alzheimer’s disease patients and mouse models lead to F1FO-ATP synthase deregulation and disruption of synaptic mitochondrial function.
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- 2016
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270. Classification and Risk-factor Analysis of Postoperative Cardio-pulmonary Complications after Lobectomy in Patients with Stage I Non-small Cell Lung Cancer
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Yutian LAI, Jianhua SU, Mingming WANG, Kun ZHOU, Heng DU, Jian HUANG, and Guowei CHE
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Lung neoplasms ,Postoperative cardio-pulmonary complications ,Risk factors ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and objective There are incresing lung cancer patients detected and diagnosed at the intermediate stage when the pre-malignant or early lesions are amenable to resection and cure, owing to the progress of medical technology, the renewal of detection methods, the popularity of medical screening and the improvement of social health consciousness. The aim of this study is to investigate the risk factors of the occurrence of postoperative cardio-pulmonary complications in stage I non-small cell lung cancer (NSCLC) patients, based on routine laboratory tests, basic characteristics, and intraoperative variables in hospital. Methods The 421 patients after lobectomy in patients with stage I NSCLC at the West China Hospital of Sichuan University from January 2012 to December 2013 were included into the study and stratified into complication group and non-complication group, according to whether to occur postoperative cardio-pulmonary complications after lobectomy in 30 days. Results Of them, 64 (15.2%) patients were finally identified and selected into the complication group, compared with 357 (84.8%) in non-complication group: pneumonia (8.8%, 37/421) was the primary complication, and other main complications included atelectasis (5.9%, 25/421), pleural effusion (≥middle) (5.0%, 21/421), persistent air leak (3.6%, 15/421); The operation time (P=0.007), amount of blood loss (P=0.034), preoperative chronic obstructive pulmonary disease (COPD) (P=0.027), white blood cell (WBC) count (P
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- 2016
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271. Whole-genome mutational burden analysis of three pluripotency induction methods
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Kunal Bhutani, Kristopher L. Nazor, Roy Williams, Ha Tran, Heng Dai, Željko Džakula, Edward H. Cho, Andy W. C. Pang, Mahendra Rao, Han Cao, Nicholas J. Schork, and Jeanne F. Loring
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Science - Abstract
It is feared that reprogramming may introduce DNA mutations. Here Bhutani et al. take three different reprogramming methods and using comparative whole genome analyses do identify nucleotide variations that are different in reprogrammed cells from the original fibroblasts, but none convey oncogenic potential.
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- 2016
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272. Casting Blanks Cleanliness Evaluation Based on Ultrasonic Microscopy and Morphological Filtering
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Heng Ding, Qingting Qian, Xue Li, Zhu Wang, and Min Li
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casting blanks cleanliness evaluation ,ultrasonic microscopy ,morphological filtering ,ultrasound signal processing ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The cleanliness of the casting blanks could seriously affect the quality of downstream products. Recently, ultrasound technology has been introduced to detect the inclusions in metal materials. However, due to the anisotropy of the material crystal, the ultrasonic wave has the characteristics of multiple scattering and refraction in its propagation process. This makes it difficult to evaluate the casting blanks cleanliness effectively, for the inclusion echoes are submerged in the background noise. Therefore, the ultrasonic microscope is innovatively proposed to carry out efficient scanning on the casting blanks. In the meantime, the morphological filtering algorithm has the advantages of fewer parameters and faster calculation speed which can be used to increase the signal-to-noise ratio of ultrasound images and extract the defect features more efficiently. In order to verify the effectiveness of the proposed method, specimens were taken from three strands of continuous caster for detection and analysis. The experimental results show that the second strand has the best quality and the cleanliness is 2.2/mm3, which is obviously better than the other two strands. This method will provide a new technology for the quantitative evaluation of the internal quality of the casting blanks.
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- 2020
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273. Experimental Study on the Flow-Induced Motion and Hydrokinetic Energy of Two T-section Prisms in Tandem Arrangement
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Nan Shao, Guobin Xu, Fang Liu, Xiang Yan, Xiaoqun Wang, Heng Deng, and Zheng Zheng
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t-section prism ,tandem ,flow induced motion ,spacing ratio ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The advantageous performance in terms of energy conversion for the flow-induced motion (FIM) of T-section prisms has been experimentally reported recently. In order to further understand the oscillation and energy conversion of multiple T-section prisms, a series of tests of two T-section prisms arranged in tandem with five different spacing ratios (3 ≤ L/D ≤ 15) and seven load resistances (8 Ω ≤ RL ≤ 41 Ω) were conducted. The effects of the spacing ratio and load resistances on energy conversion were discussed. The main conclusions can be summarized as follows. For most tests, the amplitudes of the upstream T-section prism (UTP) and downstream T-section prism (DTP) were both lower than the amplitude of the single T-section prism (STP) due to the mutual interference of the two prisms. Because of the mutual interference, the active powers of UTP and DTP were both less than that of STP, but at some special spacing ratios or load resistances, the mutual interference benefited the energy converted by the two prisms. In the presented tests, the total optimal active power of the upstream T-section prism and downstream T-section prism (UTP + DTP) was 30.12 W, which was 1.5 times that of STP (20.12 W).
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- 2020
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274. Comprehensive Profiling of Tubby-Like Protein Expression Uncovers Ripening-Related TLP Genes in Tomato (Solanum lycopersicum)
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Yaoxin Zhang, Xiaoqing He, Dan Su, Yuan Feng, Haochen Zhao, Heng Deng, and Mingchun Liu
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tubby-like proteins ,tlps ,family genes ,fruit ripening ,tomato ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Tubby-like proteins (TLPs), which were firstly identified in obese mice, play important roles in male gametophyte development, biotic stress response, and abiotic stress responses in plants. To date, the role of TLP genes in fruit ripening is largely unknown. Here, through a bioinformatics analysis, we identified 11 TLPs which can be divided into three subgroups in tomato (Solanum lycopersicum), a model plant for studying fruit development and ripening. It was shown that all SlTLPs except SlTLP11 contain both the Tub domain and F-box domain. An expression profiling analysis in different tomato tissues and developmental stages showed that 7 TLP genes are mainly expressed in vegetative tissues, flower, and early fruit developmental stages. Interestingly, other 4 TLP members (SlTLP1, SlTLP2, SlTLP4, and SlTLP5) were found to be highly expressed after breaker stage, suggesting a potential role of these genes in fruit ripening. Moreover, the induced expression of SlTLP1 and SlTLP2 by exogenous ethylene treatment and the down expression of the two genes in ripening mutants, further support their putative role in the ripening process. Overall, our study provides a basis for further investigation of the function of TLPs in plant development and fruit ripening.
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- 2020
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275. Single-Neuron Adaptive Hysteresis Compensation of Piezoelectric Actuator Based on Hebb Learning Rules
- Author
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Yanding Qin and Heng Duan
- Subjects
piezoelectric actuator ,hysteresis compensation ,single-neuron adaptive control ,hebb learning rules ,supervised learning ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
This paper presents an adaptive hysteresis compensation approach for a piezoelectric actuator (PEA) using single-neuron adaptive control. For a given desired trajectory, the control input to the PEA is dynamically adjusted by the error between the actual and desired trajectories using Hebb learning rules. A single neuron with self-learning and self-adaptive capabilities is a non-linear processing unit, which is ideal for time-variant systems. Based on the single-neuron control, the compensation of the PEA’s hysteresis can be regarded as a process of transmitting biological neuron information. Through the error information between the actual and desired trajectories, the control input is adjusted via the weight adjustment method of neuron learning. In addition, this paper also integrates the combination of Hebb learning rules and supervised learning as teacher signals, which can quickly respond to control signals. The weights of the single-neuron controller can be constantly adjusted online to improve the control performance of the system. Experimental results show that the proposed single-neuron adaptive hysteresis compensation method can track continuous and discontinuous trajectories well. The single-neuron adaptive controller has better adaptive and self-learning performance against the rate-dependence of the PEA’s hysteresis.
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- 2020
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276. Postoperative pulmonary complications following posterior spinal instrumentation and fusion for congenital scoliosis.
- Author
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Si Yin, Huiren Tao, Heng Du, Chaoshuai Feng, Yimin Yang, Weizhou Yang, and Chunguang Duan
- Subjects
Medicine ,Science - Abstract
BACKGROUND:Congenital scoliosis (CS) may lead to more serious pulmonary complications compared with idiopathic scoliosis after spinal fusion surgery. However, little has been reported about postoperative pulmonary complication events in patients with CS after spinal fusion surgery. OBJECTIVE:To investigate the incidence of and predictive factors of postoperative pulmonary complications following posterior spinal instrumentation and fusion surgery for the treatment of CS. METHODS:We retrospectively reviewed the records of 174 patients with CS (128 females and 46 males, mean age 16.4 years) treated with posterior spinal instrumentation and fusion surgery between January 2012 and April 2017. We extracted demographic, medical history, and clinical data, and investigated the major predictive factors for postoperative pulmonary complications by logistic regression and receiver-operating characteristic curves analyses. RESULTS:A total of 26 (14.9%) patients developed postoperative pulmonary complications, consisting of pleural effusion (10.9%), pneumonia (6.9%), pneumothorax (1.1%), atelectasis (2.3%), hypoxemia (6.3%), and respiratory failure (1.1%). Logistic regression analysis revealed that the predictive factors for postoperative pulmonary complications were age > 18.1 years (P = 0.039), a Cobb angle of > 77° (P = 0.011), operation time of > 430 min (P = 0.032), and blood transfusion volume > 1500 ml (P = 0.015). CONCLUSIONS:Postoperative pulmonary complications are among the main complications following posterior spinal instrumentation and fusion surgery in patients with CS. Such patients aged >18.1 years, with Cobb angles > 77°, operation times > 430 min, and/or blood transfusion volume of > 1500 ml may be more likely to develop postoperative pulmonary complications.
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- 2018
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277. Risk factors and incident coronary heart disease in Chinese, Malay and Asian Indian males: the Singapore Cardiovascular Cohort Study.
- Author
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Lee, J, Heng, D, Chia, K S, Chew, S K, Tan, B Y, and Hughes, K
- Abstract
This prospective study in Singapore investigated the relationships of established coronary risk factors with incident coronary heart disease (CHD) for Chinese, Malay, and Asian Indian males.
- Published
- 2001
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278. What are the Advantages? A Prospective Analysis of 16 versus 28 French Chest Tube Sizes in Video-assisted Thoracoscopic Surgery Lobectomy of Lung Cancer
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Mei YANG, Jun FAN, Hongxia ZHOU, Heng DU, Fang QIU, Lin LIN, Lunxu LIU, Weimin LI, and Guowei CHE
- Subjects
Chest tube size ,VATS lobectomy ,Lung neoplasms ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and objective Post-operation management of minimally invasive thoracic surgery is similar to that of open surgery, especially on the drainage tube of the chest. The aim of this study is to compare the advantages of using 16 F versus 28 F chest tubes in video-assisted thoracoscopic surgery (VATS) lobectomy of lung cancer. Methods Data from 163 patients (February-May 2014) who underwent VATS lobectomy of lung cancer with insertion of one chest drain (16 F or 28 F) were analyzed. The following post-operative data were evaluated: primary healing of tube incision, CXR abnormalities (pneumothorax, fluid, atelectasis, subcutaneous emphysema, and hematoma), drainage time, new drain insertion, and wound healing at the site of insertion. Results A total of 75 patients received 28 F chest tubes, and 88 patients received 16 F chest tubes. Both groups were similar in age, gender, comorbidities, and pathological evaluation of resection specimens. After adjustment, no statistically significant difference was found between the two groups in relation to tube-related complications including residual pneumothoraces (4.00% vs 4.44%; P=0.999), subcutaneous emphysema (8.00% vs 6.67%; P=0.789), retained hemothorax (0 vs 41%, P=0.253), and drainage time [(28.4±16.12) h vs (22.1±11.8) h; P=0.120)] The average total drainage volume and rrhythmia rates of the 16 F group [(365±106) mL, 14.67%)] was less than that of the 28 F group [(665±217) mL, 4.5%; P=0.030, P=0.047]. The rates of primary healing at the site of insertion in the 16 F group (95.45%) was higher than that in the 28 F group (77.73%, P=0.039). A significant difference was found on the post-operative length of stay of the two groups [(4.23±0.05) d vs (4.57±0.16) d, P=0.078]. Conclusion The use of 16 F chest tube for VATS lobectomy of patients with lung cancer did not affect the clinically relevant outcomes tested. However, 16 F chest tube facilitated faster wound healing at the site of insertion.
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- 2015
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279. Relationship between Clinical Characteristics and Diagnostic Modes of Hospitalized Surgical Patients with Lung Cancer
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Yutian LAI, Long TIAN, Jun FAN, Jian HUANG, Shuangjiang LI, Heng DU, and Guowei CHE
- Subjects
Diagnostic modes ,Clinical characteristics ,Lung neoplasms ,City and Township ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background and objective Diagnostic modes may play an important role in treatments, but minimal information is available regarding their relationship in patients with lung cancer. This study may contribute to decision making in clinics and public health centers. Methods The records of 505 hospitalized surgical patients with lung cancer at the Department of Thoracic Surgery, West China Hospital of Sichuan University from January 2013 to December 2013 were retrospectively reviewed. The patients were categorized into physical examination group (PEG, 131 patients) and symptomatic group (SG, 374 patients). Surgical approach, pathological stage, and diagnostic mode were analyzed. Results Low-dose computed tomography (46.6%, 61/131) and computed radiography (51.1%, 67/131) were used as key diagnosis methods in 131 patients in PEG. The percentage of hospitalized surgical patients with lung cancer detected via physical examination in the city (35.4%, 80/229) was also significantly higher than in the township (18.1%, 50/276) (P
- Published
- 2015
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280. Long non-coding RNAs: New biomarkers for prognosis and diagnosis of colon cancer
- Author
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Heng Deng, Jian Min Wang, Ming Li, Ran Tang, Kun Tang, Yingzi Su, Yong Hou, and Jun Zhang
- Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Dysregulation of long non-coding RNAs has been found in many human cancers, including colorectal cancer that is still the third most prevalent cancer worldwide and related to poor prognosis; along with this, robust testimony has identified that long non-coding RNAs can take charge of tumor suppressor genes or oncogenes. This review summarizes nowadays research achievements on the character of long non-coding RNAs in the prognosis and diagnosis of colorectal cancer. On the basis of the results acquired in the last decade, some long non-coding RNAs are rising as biomarkers of colorectal cancer for prognosis, diagnosis, even prediction of therapeutic result, and have crucial effects in the regulation of colorectal cancer cell functions such as proliferation, invasion, apoptosis, metastasis, and drug resistant ability. Also, long non-coding RNAs, circulating in body fluids, could act as novel, affordable, lightly accessible, non-invasive detection tools for the personal health management of patients with colorectal cancer. Especially, circulating long non-coding RNA profiles may be demonstrating preferable prognostic and diagnostic capability and better accuracy than respective long non-coding RNAs in colorectal cancer.
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- 2017
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281. Promising therapeutic role of miR-27b in tumor
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Li Ding, Jie Ni, Fan Yang, Lingli Huang, Heng Deng, Yang Wu, Xuansheng Ding, and Jinhai Tang
- Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
MicroRNAs are small nonprotein-encoding RNAs ranging from 18 to 25 nucleotides in size and regulate multiple biological pathways via directly targeting a variety of associated genes in cancers. MicroRNA-27b is a highly conserved MicroRNA throughout vertebrates and there are two homologs (hsa-miR-27a and hsa-miR-27b) in humans. MicroRNA-27b is an intragenic microRNA located on chromosome 9q22.1 within the C9orf3 gene, clustering with miR-23b and miR-24-1 in human. As a frequently dysregulated microRNA in human cancers, microRNA-27b could function as a tumor suppressor or an oncogenic microRNA. More and more studies indicate that microRNA-27b is involved in affecting various biological processes, such as angiogenesis, proliferation, metastasis, and drug resistance, and thus may act as a promising therapeutic target in human cancers. In this review, we discuss the role of microRNA-27b in detail and offer novel insights into molecular targeting therapy for cancers.
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- 2017
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282. Incremental update of rough set approximation under the grade indiscernibility relation
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Junfang Luo, Yaya Liu, Keyun Qin, and Heng Ding
- Subjects
Rough set ,Fuzzy relation ,The grade indiscernibility relation ,Incremental learning ,Approximation operators ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
The incremental updating of lower and upper approximations under the variation of information systems is an important issue in rough set theory. Many incremental updating approaches with respect to different kinds of indiscernibility relations have been proposed. The grade indiscernibility relation is a fuzzification of classical Pawlak’s indiscernibility relation which can characterize the similarity between objects more precisely. Based on fuzzy rough set model, this paper discusses the approaches for dynamically acquiring of the upper and lower approximations with respect to the grade indiscernibility relation when adding and removing an attribute or an object, and changing the attribute value of the object, respectively. Since the approaches are used in succession, they make the approximations can be updated correctly and effectively when any kind of possible change in the information system. Finally, extensive experiments on data sets from University of California, Irvine (UCI) show that the incremental methods effectively reduce the computing time in comparison with the traditional non-incremental method.
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- 2017
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283. A component-based system for agricultural drought monitoring by remote sensing.
- Author
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Heng Dong, Jun Li, Yanbin Yuan, Lin You, and Chao Chen
- Subjects
Medicine ,Science - Abstract
In recent decades, various kinds of remote sensing-based drought indexes have been proposed and widely used in the field of drought monitoring. However, the drought-related software and platform development lag behind the theoretical research. The current drought monitoring systems focus mainly on information management and publishing, and cannot implement professional drought monitoring or parameter inversion modelling, especially the models based on multi-dimensional feature space. In view of the above problems, this paper aims at fixing this gap with a component-based system named RSDMS to facilitate the application of drought monitoring by remote sensing. The system is designed and developed based on Component Object Model (COM) to ensure the flexibility and extendibility of modules. RSDMS realizes general image-related functions such as data management, image display, spatial reference management, image processing and analysis, and further provides drought monitoring and evaluation functions based on internal and external models. Finally, China's Ningxia region is selected as the study area to validate the performance of RSDMS. The experimental results show that RSDMS provide an efficient and scalable support to agricultural drought monitoring.
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- 2017
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284. Advancement of Relationship between Metabolic Alteration in Cancer-associated Fibroblasts and Tumor Progression in Lung Cancer
- Author
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Heng DU and Guowei CHE
- Subjects
Cancer-associated fibroblasts ,Metabolic alteration ,Lung neoplasms ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Tumor microenvironment is closely related to tumor progression. Cancer-associated fibroblasts (CAFs) are specialized fibroblasts domesticated by cancer cells surrounding them. CAFs are one of the most important components in cancer microenvironment. CAFs extensively involved in tumor genesis, tumor invasion and metastasis. Compared to NFs, CAFs also have a different metabolism type. CAFs use glycolysis to produce lactate for cancer cells. That is, CAFs turn to a metabolism type named “reverse Warburg effect” to promote tumor progression. In the present study, we summarized that: (1) Characteristics and metabolic type of CAFs; (2) The research status of the metabolism of CAFs; (3) The potential mechanism of CAFs metabolism; (4) The relation between metabolic alteration in CAFs and lung cancer progression; (5) Relationship between CAFs metabolism and lung cancer prognosis and therapy.
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- 2014
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285. Investigation of traffic adaptation based interference alignment for cognitive radio networks
- Author
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Heng DONG and Rong-fang SONG
- Subjects
interference alignment ,cognitive radio ,beam-forming ,degrees of freedom ,Telecommunication ,TK5101-6720 - Abstract
A novel method of adaptive interference alignment (IA) was proposed for cognitive radio networks. The new IA scheme, which was chiefly characterized by off-line feasible set optimization and traffic load oriented adaptation, en-ables dynamic sharing of channel resource among a pair of primary users and multiple pairs of secondary users. To effec-tively construct the beam-forming and interference suppression matrix for IA, then not only derive an adaptive closed-form algorithm, but its average degrees of freedom (d.o.f) were also analyzed with random traffic load model and a lower bound is given as well. The analysis is verified with statistic model simulation and the results show that the new method outperforms both modified opportunistic IA and fixed IA in average d.o.f and thus can significantly improve the sum capacity of cognitive users without introducing interference to the primary user. Moreover, due to its simplicity, the scheme is highly desirable to implement in low cost terminals.
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- 2014
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286. A New Optimization Method for the Layout of Pumping Wells in Oases: Application in the Qira Oasis, Northwest China
- Author
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Yi Liu, Mengyang Shen, Jianping Zhao, Heng Dai, Dongwei Gui, Xinlong Feng, Jiali Ju, Shilei Sang, Xiaoying Zhang, and Bill Hu
- Subjects
oasis ,pumping well ,optimization ,groundwater ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Oases are vital habitat areas for both humans and wild plants and animals in desert areas of arid Northwestern China. The efficient management of oasis water resources, especially groundwater resources, is very important for the environmental sustainability and economic development of the region. Pumping wells play a vital role in the oasis groundwater supply; therefore, optimizing the layout of these wells is essential for water resource management. In this study, we present a novel optimization methodology that implements a genetic algorithm and nonlinear programming model for the layout of pumping wells. The methodology was tested and evaluated in the real oasis case study of Qira Oasis located in southern Xinjiang Province, China. The optimization result shows that only 68 pumping wells are required for irrigation purposes of Qira Oasis, and this layout reduces the number of current pumping wells strongly by 59%. Thus, a large number of pumping wells can be closed to save resources. The optimizing method presented in this research is mathematically general and can be applied to other oasis areas without any obstacles. This method can provide decision-makers and managers with key information to ensure the optimal management and safety of valuable groundwater resources in oases.
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- 2019
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287. The Study of Hydrogeochemical Environments and Microbial Communities along a Groundwater Salinity Gradient in the Pearl River Delta, China
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Shilei Sang, Heng Dai, Bill X. Hu, Yanru Hao, Tong Zhou, and Jin Zhang
- Subjects
isotope geochemistry ,seawater intrusion ,environmental indicators ,16S rDNA gene sequencing ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
The salinization of groundwater is an issue in coastal areas because it causes the deterioration of freshwater resources, significantly impacting human livelihoods and ecosystems. This study integrated isotopic geochemical measurements with high-throughput sequencing of 16S rRNA gene amplicons to evaluate the source of groundwater salinity and the influence of hydrogeochemical variations on microbial communities under different salinity gradients in the Pearl River Delta of China. Results showed that the groundwater salinity in this area varied from fresh water in the inland area to brackish water, and then to saline water close to the southeast shoreline. The major ions (Na+, K+, Ca2+, Mg2+, Cl−, NO3−, SO42−, and HCO3−) and isotope analyses (2H, 3H, 18O, and 14C) indicated that the groundwater in the confined aquifer was recharged by local precipitation and seawater. A further 14C analysis showed that the salinity of the groundwater was likely attributed to the Holocene transgression. Analysis of the microbial community showed that γ-proteobacteria were frequently observed in all the groundwater samples, while the other main microbial community at class level varied greatly, from β-proteobacteria in the freshwater wells to ε-proteobacteria in the brackish wells and to Bacilli in the saline wells. Exiguobacterium and Acinetobacter were dominant in saline water and the brackish water sample of Q144, while Sulfuricurvum dominated in the brackish water sample of Q143. Aeromonas, no rank Gallionellaceae, no rank Methylophilaceae, Acidovorax, and Comamonas unevenly thrived in the freshwater samples collected from different locations. Therefore, the distribution of microbial communities reflected the salinity and hydrogeochemical characteristics of a groundwater aquifer, and can be regarded as a potential environmental indicator in the groundwater.
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- 2019
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288. An Adaptive Frequency Phase-Locked Loop Based on a Third Order Generalized Integral
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Heng Du, Qiuye Sun, Qifu Cheng, Dazhong Ma, and Xu Wang
- Subjects
single phase PLL ,third order generalized integral (TOGI) ,DC offset elimination ,adaptive frequency ,Technology - Abstract
In this paper, the basic principle and characteristics of a phase-locked loop (PLL) in a single phase grid-connected system are analyzed, and this paper introduces one type virtual orthogonal voltage vector method based on a third order generalized integrator (TOGI) to construct an alpha and beta static coordinate system. The TOGI structure can eliminate the DC offset in a voltage signal or zero offset in the sampling process, and ensure the amplitude of the virtual orthogonal signal is consistent. At the same time, the adaptive frequency estimation unit is introduced, which can effectively deal with the power grid voltage frequency changes and ensure the accuracy of PLL. MATLAB (R2012a, MathWorks, Natick, MA, USA) is used to simulate the variation of power grid voltage frequency, DC component injection, harmonics injection and other parameters, and the performance of PLL is adequately verified. In addition, a 5kW single-phase energy router experimental platform is built to verify the proposed PLL. The experimental results show that the PLL can well track the frequency change of the grid voltage and eliminate the DC offset, so as to achieve accurate phase tracking.
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- 2019
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289. Metabolic actions of pituitary growth hormone
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Bornstein, J., Ng, F. M., Heng, D., and Wong, K. P.
- Abstract
Abstract. Evidence is presented showing that human growth hormone (hGH) and its part sequence hGH 172–191 inhibit acetyl CoA carboxylase and hence fatty acid synthesis by interacting with adipocyte and hepatocyte plasma membranes, resulting in the release of a relatively non-polar second 'mesenger'. This second 'messenger' inhibits the enzyme in a soluble fraction by increasing its phosphorylation. It appears that growth hormone requires some modification prior to demonstrating this activity, as it is active in intact cells and unfractionated homogenates but has no activity in 'messenger release' from purified membrane fractions. The relations of these actions to the in vivo effects of hGH are discussed.
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- 1983
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290. Construction of a New Molecular Barcode for Discriminating Plants and Animals with a Close Genetic Relationship
- Author
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Li HUANG, Xiao-feng ZHAO, Yi-peng ZHU, Heng DONG, Ning-ying XU, and Jia-shu CAO
- Subjects
molecular barcode ,molecular marker ,Cruciferae ,Sus ,F-AFLP ,Agriculture (General) ,S1-972 - Abstract
DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism (F-AFLP) and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.
- Published
- 2013
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291. Alterations of Alternative Splicing Patterns of Ser/Arg-Rich (SR) Genes in Response to Hormones and Stresses Treatments in Different Ecotypes of Rice (Oryza sativa)
- Author
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Peng ZHANG, Heng DENG, Fang-ming XIAO, and Yong-sheng LIU
- Subjects
SR protein ,alternative splicing ,stress ,rice ,Agriculture (General) ,S1-972 - Abstract
Ser/Arg-rich (SR) genes encode proteins that play pivotal roles in both constitutive and alternative splicing of pre-mRNA. However, not much effort has been made to investigate the alternative splicing of their own pre-mRNA. In this study, we conducted comprehensive analyses of pre-mRNA splicing for 22 SR genes in three rice (Oryza sativa L.) ecotypes indica, japonica and javanica. Using different ecotypes we characterized the variations in expression and splicing patterns of rice SR genes in different tissues and at different developmental stages. In addition, we compared the divergence in expression and splicing patterns of SR genes from seedlings of different rice ecotypes in response to hormones application and environmental stresses. Our results revealed the complexity of alternative splicing of SR genes in rice. The splicing varies in different tissues, in different ecotypes, in response to stresses and hormones. Thus, our study suggested that SR genes were subjected to sophisticated alternative splicing although their encoding proteins were involved in the splicing process.
- Published
- 2013
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292. The design, simulation, and experiment of high-accuracy multi-axle electro-hydraulic control servo steering system
- Author
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Heng Du, JianHua Wei, and JinHui Fang
- Subjects
Mechanical engineering and machinery ,TJ1-1570 - Abstract
Many multi-axle applications use electro-hydraulic control systems with proportional valves. The proportional steering system can satisfy common engineering requirements, but it is likely to fail if the steering angle or load changes drastically because of poor dynamic characteristics, including dead zones, hysteresis, and frequency response. An electro-hydraulic servo steering system with servo solenoid valve is proposed to guarantee a precise dynamic response and good price–performance ratio of the closed-loop system. A co-simulation model based on ADAMS and AMESim was established to analyze the influence of the main parameters on steering performance. The mechanical model includes tire and ground parts, and the steering load can be simulated accurately. The simulation results show that dead zones, hysteresis, and frequency response of control valve have great influence on the steering performance, and the servo solenoid valve is proper for this system. The servo steering system was applied to the actual seven-axle all-terrain crane, and the system performance was extensively tested. The experiment results show that the system has good accuracy and tracking response performance in several real situations, including parking and high-speed transport.
- Published
- 2016
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293. Design and analysis of mechanic-hydraulic servo control steering system for pure rolling in multi-axle vehicle
- Author
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Heng Du, Jixiao Ye, and Bin Huang
- Subjects
Mechanical engineering and machinery ,TJ1-1570 - Abstract
With more axles for multi-axle vehicles, conventional steering trapeziums are unable to let every tire fit Ackermann steering which cause tire wear increasingly more serious. To alleviate this problem, an original mechanic-hydraulic servo steering system with a controllable tie rod is designed. By controlling the angle of one wheel and the length of tie rod, both wheels can be controlled as per default trajectory which implemented Ackermann steering. This article utilized mechanic-hydraulic servo feedback to design a mechanic-hydraulic servo valve which controlled the tie rod accurately. It ensured dynamic characteristics of steering wheels and driving force. To understand inherent characteristics of system, the mathematical model was established. The transfer function was derived, and this high-order system was reduced by Routh approximation. Analyzed natural frequency and the main parameter (the gain coefficient of displacement) which influences the dynamic characteristics had been found out. Analysis shows that the lower the gain coefficient, the higher the speed of response. Moreover, the accurate simulation model of servo system is built on AMESim. Contrasting five groups of simulation results, it is obtained that the influence rule of the gain coefficient is consistent with theoretical analysis. This research provides a useful reference for future nonlinear control.
- Published
- 2016
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294. Analysis of a Mouse Skin Model of Tuberous Sclerosis Complex.
- Author
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Yanan Guo, John R Dreier, Juxiang Cao, Heng Du, Scott R Granter, and David J Kwiatkowski
- Subjects
Medicine ,Science - Abstract
Tuberous Sclerosis Complex (TSC) is an autosomal dominant tumor suppressor gene syndrome in which patients develop several types of tumors, including facial angiofibroma, subungual fibroma, Shagreen patch, angiomyolipomas, and lymphangioleiomyomatosis. It is due to inactivating mutations in TSC1 or TSC2. We sought to generate a mouse model of one or more of these tumor types by targeting deletion of the Tsc1 gene to fibroblasts using the Fsp-Cre allele. Mutant, Tsc1ccFsp-Cre+ mice survived a median of nearly a year, and developed tumors in multiple sites but did not develop angiomyolipoma or lymphangioleiomyomatosis. They did develop a prominent skin phenotype with marked thickening of the dermis with accumulation of mast cells, that was minimally responsive to systemic rapamycin therapy, and was quite different from the pathology seen in human TSC skin lesions. Recombination and loss of Tsc1 was demonstrated in skin fibroblasts in vivo and in cultured skin fibroblasts. Loss of Tsc1 in fibroblasts in mice does not lead to a model of angiomyolipoma or lymphangioleiomyomatosis.
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- 2016
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295. Synaptosomal Mitochondrial Dysfunction in 5xFAD Mouse Model of Alzheimer's Disease.
- Author
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Lu Wang, Lan Guo, Lin Lu, Huili Sun, Muming Shao, Simon J Beck, Lin Li, Janani Ramachandran, Yifeng Du, and Heng Du
- Subjects
Medicine ,Science - Abstract
Brain mitochondrial dysfunction is hallmark pathology of Alzheimer's disease (AD). Recently, the role of synaptosomal mitochondrial dysfunction in the development of synaptic injury in AD has received increasing attention. Synaptosomal mitochondria are a subgroup of neuronal mitochondria specifically locating at synapses. They play an essential role in fueling synaptic functions by providing energy on the site; and their defects may lead to synaptic failure, which is an early and pronounced pathology in AD. In our previous studies we have determined early synaptosomal mitochondrial dysfunction in an AD animal model (J20 line) overexpressing human Amyloid beta (Aβ), the key mediator of AD. In view of the limitations of J20 line mice in representing the full aspects of amyloidopathy in AD cases, we employed 5xFAD mice which are thought to be a desirable paradigm of amyloidopathy as seen in AD subjects. In addition, we have also examined the status of synaptosomal mitochondrial dynamics as well as Parkin-mediated mitophagy which have not been previously investigated in this mouse model. In comparison to nontransgenic (nonTg mice), 5xFAD mice demonstrated prominent synaptosomal mitochondrial dysfunction. Moreover, synaptosomal mitochondria from the AD mouse model displayed imbalanced mitochondrial dynamics towards fission along with activated Parkin and LC3BII recruitment correlating to spatial learning & memory impairments in 5xFAD mice in an age-dependent manner. These results suggest that synaptosomal mitochondrial deficits are primary pathology in Aβ-rich environments and further confirm the relevance of synaptosomal mitochondrial deficits to the development of AD.
- Published
- 2016
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296. Experimental Investigation of Flow-Induced Motion and Energy Conversion of a T-Section Prism
- Author
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Nan Shao, Jijian Lian, Guobin Xu, Fang Liu, Heng Deng, Quanchao Ren, and Xiang Yan
- Subjects
flow-induced motion ,sharp sections ,T-section prism ,load resistances ,section aspect ratios ,energy conversion ,Technology - Abstract
Flow-induced motion (FIM) performs well in energy conversion but has been barely investigated, particularly for prisms with sharp sections. Previous studies have proven that T-section prisms that undergo galloping branches with high amplitude are beneficial to energy conversions. The FIM experimental setup designed by Tianjin University (TJU) was improved to conduct a series of FIM responses and energy conversion tests on a T-section prism. Experimental results are presented and discussed, to reveal the complete FIM responses and power generation characteristics of the T-section prism under different load resistances and section aspect ratios. The main findings are summarized as follows. (1) Hard galloping (HG), soft galloping (SG), and critical galloping (CG) can be observed by varying load resistances. When the load resistances are low, HG occurs; otherwise, SG occurs. (2) In the galloping branch, the highest amplitude and the most stable oscillation cause high-quality electrical energy production by the generator. Therefore, the galloping branch is the best branch for harvesting energy. (3) In the galloping branch, as the load resistances decrease, the active power continually increases until the prism is suppressed from galloping to a vortex-induced vibration (VIV) lower branch with a maximum active power Pharn of 21.23 W and a maximum ηout of 20.2%. (4) Different section aspect ratios (α) can significantly influence the FIM responses and energy conversions of the T-section prism. For small aspect ratios, galloping is hardly observed in the complete responses, but the power generation efficiency (ηout,0.8 = 27.44%) becomes larger in the galloping branch.
- Published
- 2018
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297. Unlocking the Door to Neuronal Woes in Alzheimer’s Disease: Aβ and Mitochondrial Permeability Transition Pore
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Heng Du and Shirley ShiDu Yan
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amyloid beta ,mitochondrial permeability transition ,cyclophilin D ,therapy ,Medicine ,Pharmacy and materia medica ,RS1-441 - Abstract
Mitochondrial dysfunction occurs early in the progression of Alzheimer’s disease. Amyloid-β peptide has deleterious effects on mitochondrial function and contributes to energy failure, respiratory chain impairment, neuronal apoptosis, and generation of reactive oxygen species in Alzheimer’s disease. The mechanisms underlying amyloid-β induced mitochondrial stress remain unclear. Emerging evidence indicates that mitochondrial permeability transition pore is important for maintenance of mitochondrial and neuronal function in aging and neurodegenerative disease. Cyclophilin D (Cyp D) plays a central role in opening mitochondrial permeability transition pores, ultimately leading to cell death. Interaction of amyloid-β with cyclophilin D triggers or enhances the formation of mitochondrial permeability transition pores, consequently exacerbating mitochondrial and neuronal dysfunction, as shown by decreased mitochondrial membrane potential, impaired mitochondrial respiration function, and increased oxidative stress and cytochrome c release. Blockade of cyclophilin D by genetic abrogation or pharmacologic inhibition protects mitochondria and neurons from amyloid-β induced toxicity, suggesting that cyclophilin D dependent mitochondrial transition pores are a therapeutic target for Alzheimer’s disease.
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- 2010
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298. Progression of Epididymal Maldevelopment Into Hamartoma-like Neoplasia in VHL Disease
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Gautam U. Mehta, Sharon B. Shively, Heng Duong, Maxine G.B. Tran, Travis J. Moncrief, Jonathan H. Smith, Jie Li, Nancy A. Edwards, Russell R. Lonser, Zhengping Zhuang, Marsha J. Merrill, Mark Raffeld, Patrick H. Maxwell, Edward H. Oldfield, and Alexander O. Vortmeyer
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Inactivation of the von Hippel-Lindau (VHL) gene and activation of the hypoxia-inducible factor (HIF) in susceptible cells precedes formation of tumorlets and frank tumor in the epididymis of male VHL patients. We performed detailed histologic and molecular pathologic analysis of tumor-free epididymal tissues from VHL patients to obtain further insight into early epididymal tumorigenesis. Four epididymides from two VHL patients were serially sectioned to allow for three-dimensional visualization of morphologic changes. Areas of interest were genetically analyzed by tissue microdissection, immunohistochemistry for HIF and markers for mesonephric differentiation, and in situ hybridization for HIF downstream target vascular endothelial growth factor. Structural analysis of the epididymides revealed marked deviations from the regular anatomic structure resulting from impaired organogenesis. Selected efferent ductules were represented by disorganized mesonephric cells, and the maldeveloped mesonephric material was VHL-deficient by allelic deletion analysis. Furthermore, we observed maldeveloped mesonephric material near cystic structures, which were also VHL-deficient and were apparent derivatives of maldeveloped material. Finally, a subset of VHL-deficient cells was structurally integrated in regular efferent ductules; proliferation of intraductular VHL-deficient cells manifests itself as papillary growth into the ductular lumen. Furthermore, we clarify that that there is a pathogenetic continuum between microscopic tumorlets and formation of tumor. In multiple locations, three-dimensional reconstruction revealed papillary growth to extend deeply into ductular lumina, indicative of progression into early hamartoma-like neoplasia. We conclude epididymal tumorigenesis in VHL disease to occur in two distinct sequential steps: maldevelopment of VHL-deficient mesonephric cells, followed by neoplastic papillary proliferation.
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- 2008
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299. Transient Cerebral Ischemia Promotes Brain Mitochondrial Dysfunction and Exacerbates Cognitive Impairments in Young 5xFAD Mice.
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Lin Lu, Lan Guo, Esha Gauba, Jing Tian, Lu Wang, Neha Tandon, Malini Shankar, Simon J Beck, Yifeng Du, and Heng Du
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Medicine ,Science - Abstract
Alzheimer's disease (AD) is heterogeneous and multifactorial neurological disorder; and the risk factors of AD still remain elusive. Recent studies have highlighted the role of vascular factors in promoting the progression of AD and have suggested that ischemic events increase the incidence of AD. However, the detailed mechanisms linking ischemic insult to the progression of AD is still largely undetermined. In this study, we have established a transient cerebral ischemia model on young 5xFAD mice and their non-transgenic (nonTg) littermates by the transient occlusion of bilateral common carotid arteries. We have found that transient cerebral ischemia significantly exacerbates brain mitochondrial dysfunction including mitochondrial respiration deficits, oxidative stress as well as suppressed levels of mitochondrial fusion proteins including optic atrophy 1 (OPA1) and mitofusin 2 (MFN2) in young 5xFAD mice resulting in aggravated spatial learning and memory. Intriguingly, transient cerebral ischemia did not induce elevation in the levels of cortical or mitochondrial Amyloid beta (Aβ)1-40 or 1-42 levels in 5xFAD mice. In addition, the glucose- and oxygen-deprivation-induced apoptotic neuronal death in Aβ-treated neurons was significantly mitigated by mitochondria-targeted antioxidant mitotempo which suppresses mitochondrial superoxide levels. Therefore, the simplest interpretation of our results is that young 5xFAD mice with pre-existing AD-like mitochondrial dysfunction are more susceptible to the effects of transient cerebral ischemia; and ischemic events may exacerbate dementia and worsen the outcome of AD patients by exacerbating mitochondrial dysfunction.
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- 2015
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300. Normative data for the Singapore English and Chinese SF-36 version 2 health survey
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Sow, W. T., Wee, H. L., Wu, Y., E Shyong Tai, Gandek, B., Lee, J., Ma, S., Heng, D., and Thumboo, J.
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Adult ,Male ,Singapore ,Young Adult ,Quality of Life ,Humans ,Female ,General Medicine ,Prospective Studies ,Middle Aged ,Health Surveys ,Language - Abstract
Introduction: The aim of this study is to report normative data for the Short-Form 36 version 2 (SF-36v2) for assessing health-related quality of life, in the Singapore general population. Materials and Methods: Data for English and Chinese-speaking participants of the Singapore Prospective Study Programme were analysed. The SF-36v2 scores were norm-based with the English-speaking Singapore general population as reference and reported by age (in decades), gender and ethnicity as well as for the 5 most prevalent chronic medical conditions. Scores were reported separately for the English and Chinese language versions. Results: A total of 6151 English-speaking (61.5% Chinese and 19.2% Malay) and 1194 Chinese-speaking participants provided complete data. Mean (SD) age of all participants was 49.6 (12.58) years with 52.4% being women. In both languages, women reported lower scores than men on all scales. Among the chronic medical conditions, stroke had the largest impact on all English SF-36v2 scales and on 3 Chinese SF-36v2 scales (role-physical, general health and social functioning). Conclusion: We have provided detailed normative data for the Singapore English and Chinese SF-36v2, which would be valuable in furthering HRQoL research in Singapore and possibly the region. Key words: Health-related quality of life, Health status, Mental well-being, Social well-being
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