Heavy Metal Contamination of Soils: a Global Challenge to Food Security

Zhenli He,Xiaoe Yang,Virupax C Baligar 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Pole-to-Ground Fault Analysis for MMC-HVDC Grid

Zhen He,Jiabing Hu,Lei Lin,Zhiyuan He 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Pole-to-ground (PTG) fault analysis is of vital importance for HVDC grid. However, many factors are not considered in the existing studies, such as the asymmetrical property of PTG fault, the coupling issue between dc transmission lines and the complexity of dc grid’s structure. This paper presents a PTG fault analysis method, which is based on common- and differential-mode (CDM) transformation. Similar to the symmetrical component method in ac system, the transformation decomposes the HVDC grid into CDM networks at first. Then, under the perspective of CDM components, a transfer impedance based analysis is performed to obtain the analytical expressions of PTG fault characteristics. The proposed PTG fault analysis method is applicable to arbitrary HVDC grid topologies. And the analytical expressions can give theoretical guidance for fault protection. The validity of the proposed PTG fault analysis method is verified by comparison with the simulation results in PSCAD/EMTDC.

Atrial fibrillation in critically ill patients who received prolonged mechanical ventilation: a nationwide inpatient report

( Zhen Lin ),( Hedong Han ),( Wei Guo ),( Xin Wei ),( Zhijian Guo ),( Shujie Zhai ),( Shuai Li ),( Yiming Ruan ),( Fangyuan Hu ),( Dongdong Li ),( Jia He ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.6

Background/Aims: To evaluate temporal trends of atrial fibrillation (AF) prevalence in critically ill patients who received prolonged mechanical ventilation (MV) in the United States. Methods: We used the 2008 to 2014 National Inpatient Sample to compute the weighted prevalence of AF among hospitalized adult patients on prolonged MV. We used multivariable-adjusted models to evaluate the association of AF with clinical factors, in-hospital mortality, hospitalization cost, and length of stay (LOS). Results: We identified 2,578,165 patients who received prolonged MV (21.27% of AF patients). The prevalence of AF increased from 14.63% in 2008 to 24.43% in 2014 (p for trend < 0.0001). Amongst different phenotypes of critically ill patients, the prevalence of AF increased in patients with severe sepsis, asthma exacerbation, congestive heart failure exacerbation, acute stroke, and cardiac arrest. Older age, male sex, white race, medicare access, higher income, urban teaching hospital setting, and Western region were associated with a higher prevalence of AF. AF in critical illness was a risk factor for in-hospital death (odds ratio, 1.13; 95% confidence interval, 1.11 to 1.15), but in-hospital mortality in critically ill patients with AF decreased from 11.6% to 8.3%. AF was linked to prolonged LOS (2%, p < 0.0001) and high hospitalization cost (4%, p < 0.0001). LOS (-1%, p < 0.0001) and hospitalization cost (-4%, p < 0.0001) decreased yearly. Conclusions: The prevalence of comorbid AF is increasing, particularly in older patients. AF may lead to poorer prognosis, and high-quality intensive care is imperative for this population.

Benefit of Post-mastectomy Radiotherapy of the Supra-/infraclavicular Lymphatic Drainage Area in Breast Cancer Patients

He, Zhen-Yu,Wu, San-Gang,Zhou, Juan,Sun, Jia-Yuan,Li, Feng-Yan,Lin, Qin,Guo, Ling,Lin, Huan-Xin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Background: This study investigated the survival benefit of radiotherapy (RT) of the supra- and infraclavicular lymphatic drainage area in Chinese women with T1-2N1M0 breast cancer receiving mastectomy. Methods: A total of 593 cases were retrospectively reviewed from 1998 to 2007. The relationship between supra- or infraclavicular fossa relapse (SCFR) and post-operative RT at the supra-/infraclavicular lymphatic drainage area was evaluated. Results: The majority of patients (532/593; 89. 8%) received no RT while 61 patients received RT. The median follow-up was 85 months. Among patients without RT, 54 (10. 2%) developed recurrence in the chest wall or ipsilateral SCFR. However, none of the 61 patients who underwent RT demonstrated SCFR. One patient who received RT (1. 6%) experienced recurrence in the chest wall. Univariate analysis revealed that age and molecular subtype (both P < 0. 05) were two prognostic factors related to supraclavicular and infraclavicular fossa relapse-free survival (SFRFS). Multivariate analysis revealed that only Her-2 positive status (P = 0. 011) was an independent predictor of SFRFS. RT had no influence on distant metastasis (P = 0. 328) or overall survival (P = 0. 541). SCFR significantly affected probability of distant metastasis (P < 0. 001) and overall survival (P < 0. 001). Conclusion: Although RT was not significantly associated with SFRFS, postoperative RT was significantly associated with a lower locoregional (i. e., supraclavicular/infraclavicular and chest wall) recurrence rate. SCFR significantly influenced distant metastasis-free survival, which significantly influenced the overall survival of T1-2N1M0 breast cancer patients after mastectomy. Thus, prophylactic RT is recommended in T1-2N1M0 breast cancer patients, especially those who have Her-2 positive lesions.

GENERALIZED PROJECTION AND APPROXIMATION FOR GENERALIZED VARIATIONAL INEQUALITIES SYSTEM IN BANACH SPACES

He, Xin-Feng,Xu, Yong-Chun,He, Zhen The Youngnam Mathematical Society Korea 2008 East Asian mathematical journal Vol.24 No.1

The approximate solvability of a generalized system for non-linear variational inequality in Hilbert spaces was studied, based on the convergence of projection methods. But little research was done in Banach space. The primary reason was that projection mapping lacked preferably property in Banach space. In this paper, we introduced the generalized projection methods. By using these methods, the results presented in this paper extended the main results of S. S. Chang [3] from Hilbert spaces to Banach space.

The Dynamic Mechanical Properties for Recycled Aggregate Concrete under Tensile-Compressive States

Zhen-Jun He,Zhi-qiang Wang,Meng-jia Ding,Zhen-wei Wang,Xiao-jie Zhang,Lian-shuo Liu 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.5

The experiments under biaxial tensile-compressive (T-C) complex stress were carried out for two kinds of substitution percentages of recycled coarse aggregate (RCA) on biaxial proportional loading (α = σ1:σ3 =1:0, 0: -1, 0.05: -1, 0.1: -1, 0.25: -1, 0.5: -1, 1: -1 and-1: -1) and four loading deformation rates of 10−5/s, 10−4/s , 10−3/s, and 10−2/s. The research was completed in the static-dynamic true triaxial machine. The experimental phenomena indicate the tensile failure appears in these specimens of recycled aggregate concrete (RAC) under biaxial T-C stress states. The dynamic mechanical behavior for RAC under biaxial T-C loadings was affected by the strain rates, stress ratios and its substitution percentages of RCA. Accompanied by the increase of strain rates, its strength of RAC is improved. As the tensile stress increases, its compressive strength decreases. The T-C strengths for RAC under biaxial T-C states are less than its corresponding uniaxial T-C strengths at a certain identical strain rates, respectively. Considering the effect of loading rates, a new tensile-compressive failure criterion is established under complex stress states.

ON THE EXISTENCE OF SOLUTIONS OF EXTENDED GENERALIZED VARIATIONAL INEQUALITIES IN BANACH SPACES

He, Xin-Feng,Wang, Xian,He, Zhen The Youngnam Mathematical Society 2009 East Asian mathematical journal Vol.25 No.4

In this paper, we study the following extended generalized variational inequality problem, introduced by Noor (for short, EGVI) : Given a closed convex subset K in q-uniformly smooth Banach space B, three nonlinear mappings T : $K\;{\rightarrow}\;B^*$, g : $K\;{\rightarrow}\;K$, h : $K\;{\rightarrow}\;K$ and a vector ${\xi}\;{\in}\;B^*$, find $x\;{\in}\;K$, $h(x)\;{\in}\;K$ such that <Tx-$\xi$, g(y)-h(x)> $\geq$ 0, for all $y\;{\in}\;K$, $g(y)\;{\in}\;K$. [see [2]: M. Aslam Noor, Extended general variational inequalities, Appl. Math. Lett. 22 (2009) 182-186.] By using sunny nonexpansive retraction $Q_K$ and the well-known Banach's fixed point principle, we prove existence results for solutions of (EGVI). Our results extend some recent results from the literature.

SPEED UP EXECUTION OF PARALLEL LOOP

He, Wang Yi,Yu, Wang Zhen,Tong, Sun,Shun, Guo Fu 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1

When sequential loops are transformed into parallel loops that can be executed on distributed parallel computer system, the backward data dependence introduced by loops greatly weakens parallel degree. This paper analyzes performances of this kind of dependence and presents a loop-restructuring method to eliminate it or decrease its intensity as much as possible. In addition, the technique of reducing synchronization overhead given in 〔3〕 is spread to reduce communication overhead between iterations of parallel loops.

FCP 15 : A case of extranodal NK/T cell Lymphoma mimicking refractory Behcet`s disease

( He Min Lee ),( Do Young Kim ),( Min Ju Choi ),( Suh Yun Cho ),( Zhen Long Zheng ),( Soo Hee Kim ),( Dong Sik Bang ) 대한피부과학회 2014 대한피부과학회 학술발표대회집 Vol.66 No.1

A 39-year-old female was diagnosed with complete type Behcet’s disease (BD) having symptoms of oral ulcer, genital ulcer, uveitis and erythema nodosum-like skin lesions. Colchicine, azathioprine or mycophenolate mofetil and systemic corticosteroid were prescribed to reduce the symptoms. However, active uveitis and cutaneous lesions persisted despite treatment. Under suspicious lung involvement of BD, infliximab was started to lessen systemic inflammation yet wihout much effect. Subsequent lung biopsy to investigate pulmonary infiltrate revealed opportunistic infection by Pneumocystis jiroveci. After stopping infliximab infusion, prednisolone in 1mg/kg/day dose was maintained with other immunosuppressants. Surprisingly, cytological specimen from palliative surgery to improve visual acuity discovered a concurrent involvement of vitreoretinal large cell lymphoma. Additional biopsy performed on hard palate ulceration which initially thought to be a symptom of BD revealed unexpected extranodal NK/T cell lymphoma involvement, and retrospective review of pathological slides of skin also revealed the presence of lymphoma. BD should be always suspected of its final diagnosis when systemic vasculitic inflammation persists without any plausible cause. If symptoms are not alleviated even with intense systemic treatments, other suspicious diagnosis including malignancy should be doubted in practice.

Study on the influencing factors of rural tourism behavior intention in China based on the theory of planned behavior

Zhen hua He,Jae yeon Sim 한국융합학회 2020 한국융합학회논문지 Vol.11 No.12

중국 국민의 경제 수준이 점진적으로 향상되고, 명절과 공휴일제도가 지속적으로 개선되면서, 마음을 안정시키 는 생활체험이 주요 목적으로 부각되면서 농촌 관광이 급속도로 발전하였다. 농업인의 기업가정신, 농가소득 증대, 농 촌 번영 및 관광경영학과, 관광기업의 경영 및 운영목표 달성을 위하여, 본 연구는 관련 문헌 검토와 참고자료에 기초 하여 연구 가설을 제시하였다. 본 논문은 앞선 연구결과를 바탕으로 주민의 농촌관광 행동 의도에 대한 설문조사를 하였고, SPSS23.0을 이용하여 표본 데이터에 대한 상관분석과 가설검증을 통하여 다음과 같은 결론을 도출하였다. (1) 시골 관광 태도, 주관적인 규범과 지각 행위 통제가 농촌 관광 행위의 방향에 긍정적인 영향을 미친다는 것이다. (2)정 책 시스템과 자원 조건은 농촌 관광 행동 의도에 상당히 긍정적인 영향을 미친다는 것이다. (3)정책 시스템은 주관적 규범과 인식된 행동 통제에 상당히 긍정적인 영향을 미치고, 자원 조건은 농촌 관광 태도, 주관적 규범, 인식된 행동 통제에 모두 상당히 긍정적인 영향을 미친 것으로 나타났다. With the gradual improvement of China's residents' economic level, the continuous improvement of the holiday system, and the main purpose of relaxing mood and experiencing life, rural tourism has developed rapidly. In order to further achieve the goals of farmers' entrepreneurship, agricultural income increase, rural prosperity, and tourism management departments and tourism enterprises' management and operation objectives, this paper puts forward research hypotheses on the basis of relevant literature review and references. Based on the previous research results, this paper designs a questionnaire on Residents' rural tourism behavior intention, and uses SPSS23.0 to conduct correlation analysis and hypothesis test on the sample data, and draws the following conclusions: (1) rural tourism attitude, subjective norms, and perceived behavior control have a significant positive impact on rural tourism behavior intention; (2) policy system and resource conditions have a significant positive impact on rural tourism behavior intention; (3) policy system has a significant positive impact on subjective norms and perceived behavior control, and resource conditions have a significant positive impact on rural tourism attitude, subjective norms, and perceived behavior control.