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Improved Dynamic Response of DC to DC Converter Using Hybrid PSO Tuned Fuzzy Sliding Mode Controller

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Circuits and Systems 2016年第6期7卷 946-955页

作者： R. Anand P. melba Mary Department of EEE National College of Engineering Tirunelveli India VV College of Engineering Tisaiyanvilai India

DC/DC switching converters are widely used in numerous appliances in modern existence. In this paper, the dynamic and transient response of phase shift series resonant DC/DC converter are improved using hybrid particle swarm optimization tuned fuzzy sliding mode controller under starting and load step change conditions. The aim of the control is to regulate the output voltage beneath the load change. The model of the hybrid particle swarm optimization tuned fuzzy sliding mode controller is implemented using Sim Power Systems toolbox of MATLAB SIMULINK. Performance of the proposed dynamic novel control under step load change condition is investigated.

关键词： DC to DC Converter Dynamic Response Hybrid Particle Swarm Optimization Ripple Voltage Sliding Mode Controller

Analysis of the in vitro degradation and the in vivo tissue response to bi-layered 3D-printed scaffolds combining PLA and biphasic PLA/bioglass components--Guidance of the inflammatory response as basis for osteochondral regeneration

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Bioactive Materials 2017年第4期2卷 208-223页

作者： Mike Barbeck Tiziano Serra Patrick Booms Sanja Stojanovic Stevo Najman Elisabeth Engel Robert Sader Charles James Kirkpatrick melba Navarro Shahram Ghanaati Private Office BerlinGermany Institute for Bioengineering of Catalonia(IBEC) Biomaterials for Regenerative MedicineBarcelonaSpain Clinic of Oro-Maxillofacial and Plastic Surgery FORM-LabGoethe University FrankfurtFrankfurtGermany University of Ni's Faculty of MedicineDepartment for Cell and Tissue EngineeringInstitute of Biology and Human GeneticsNi'sSerbia Technical University of Catalonia(UPC) Dpt.Materials Science and MetallurgySpain CIBER en Bioingenieria Biomateriales y Nanomedicina(CIBER-BBN)Spain

The aim of the present study was the in vitro and in vivo analysis of a bi-layered 3D-printed scaffold combining a PLA layer and a biphasic PLA/bioglass G5 layer for regeneration of osteochondral defects in vivo Focus of the in vitro analysis was on the(molecular)weight loss and the morphological and mechanical variations after immersion in *** in vivo study focused on analysis of the tissue reactions and differences in the implant bed vascularization using an established subcutaneous implantation model in CD-1 mice and established histological and histomorphometrical *** scaffold parts kept their structural integrity,while changes in morphology were observed,especially for the PLA/G5 *** properties decreased with progressive degradation,while the PLA/G5 scaffolds presented higher compressive modulus than PLA *** tissue reaction to PLA included low numbers of BMGCs and minimal vascularization of its implant beds,while the addition of G5 lead to higher numbers of BMGCs and a higher implant bed *** revealed that the use of a bi-layered scaffold shows the ability to observe distinct in vivo response despite the physical proximity of PLA and PLA/G5 ***,the results showed that the addition of G5 enables to reduce scaffold weight loss and to increase mechanical ***,the addition of G5 lead to a higher vascularization of the implant bed required as basis for bone tissue regeneration mediated by higher numbers of BMGCs,while within the PLA parts a significantly lower vascularization was found optimally for chondral ***,this data show that the analyzed bi-layered scaffold may serve as an ideal basis for the regeneration of osteochondral tissue ***,the results show that it might be able to reduce the number of experimental animals required as it may be possible to analyze the tissue response to more than one implant in one experimental animal.

关键词： Bioactive glass Polylactic acid(PLA) Bi-layer scaffold Multinucleated giant cells Bone substitute Vascularization Calcium phosphate glass

Our experience in sperm morphology assessment

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Asian Journal of Andrology 2011年第2期13卷 201-202页

作者： Julia Irene Ariagno Susana Mercedes Curi Patricia Chenlo Herberto Ernesto Hector Repetto Mercedes Norma Pugliese Luis Alberto Palaoro melba Sardi Gabriela Ruth Mendeluk Laboratory of Male Fertility Department of ClinicalBiochemistry INFIBIOC Faculty of Pharmacy andBiochemistry University of Buenos Aires BuenosAires 1120 Argentina

We read with great interest the article recently published by Menkeveld et aL1 as we have a double interest in sperm morphology assessment. The first one as a Clinical Andrology Laboratory （Laboratory of Male Fertility, Department of Clinical Biochemistry, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Argentina）

关键词： Semen Mankind Biochemistry Argentina (fish) Argentina Argentina (Federal District) Laboratories

光学相干断层成像评估高血压性视网膜病变神经元损伤应用价值的研究

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中国全科医学 2024年第9期27卷 1082-1087页

作者：赵润泽孙小佳 melba Marquez Hernandez 窦国睿空军军医大学西京医院眼科、全军眼科研究所陕西省西安市710032 Lázaro#701 esq.a Belascoaín Centro HabanaLa HabanaCuba.Hospital Clínico Quirúrgico“Hermanos Ameijeiras”(HHA)Calle San 10400Cube

背景当前高血压的患病率呈逐年增长趋势,其眼部并发症高血压视网膜病也日益受到关注。然而目前对于高血压性视网膜病变中神经元损伤的研究尚少。目的本研究以光学相干断层成像检查为检查手段,探究其在高血压性视网膜病变中神经元损伤评... 详细信息

背景当前高血压的患病率呈逐年增长趋势,其眼部并发症高血压视网膜病也日益受到关注。然而目前对于高血压性视网膜病变中神经元损伤的研究尚少。目的本研究以光学相干断层成像检查为检查手段,探究其在高血压性视网膜病变中神经元损伤评估中的应用和重要价值。方法纳入2019年3月—2020年7月于Hospital Clínico Quirúrgico“Hermanos Ameijeiras”(HHA医院)就诊的102例高血压患者为研究对象,同时纳入45名健康受试者,监测24 h动态血压,取24 h舒张压和收缩压的平均动脉血压值,测量眼压,计算眼灌注压。检测视盘区视网膜神经纤维(RNFL)厚度和黄斑区神经节细胞复合层(GCC)厚度。依据血压控制情况将患者分为血压控制组(n=51)和血压未控制组(n=51),45名健康受试者为对照组。采用Pearson相关性分析或Spearman秩相关分析探究血压、眼灌注压、视网膜病变与GCC厚度和血压、眼灌注压与视网膜病变的相关性,采用R 3.5.3软件进行中介作用分析。结果3组研究对象人种、收缩压、舒张压、平均动脉压、眼压、眼灌注压、视网膜病变比较,差异有统计学意义(P<0.05)。血压未控制组平均RNFL厚度低于对照组(P<0.05),血压控制组、血压未控制组GCC平均厚度低于对照组,血压未控制组GCC最小值低于对照组(P<0.05)。相关性分析结果显示,GCC平均厚度、上方GCC厚度、颞下方CCG厚度与收缩压、舒张压、眼灌注压、视网膜病变呈负相关(P<0.05),颞上方GCC厚度与收缩压、舒张压、眼灌注压呈负相关(P<0.05),下方GCC厚度与舒张压呈负相关(P<0.05),视网膜病变与收缩压、舒张压、眼灌注压呈正相关(P<0.05)。中介效应结果显示,“收缩压→GCC平均厚度→高血压性视网膜病变”效应显著,收缩压与GCC平均厚度呈正相关,GCC平均厚度与高血压性视网膜病变呈正相关(P<0.05)。收缩压对高血压性视网膜病变发生风险具有直接影响(β=0.013,95%CI=0.007~0.020,P<0.001),GCC平均厚度部分介导了收缩压对高血压性视网膜病变发生风险的影响(β=0.117,95%CI=0.014~0.360,P=0.04),中介效应占总效应的11.7%。结论光学相干断层成像检查是一种无创的眼科检查方法,可优于普通眼底检查提前发现高血压性视网膜神经元受损情况,对高血压导致视神经受损的不可逆盲和高血压靶器官受损进行早期预防和预警。

关键词：高血压性视网膜病变高血压光学相干断层成像术神经纤维中介分析

Engagement in clinical learning environment among nursing students: Role of nurse educators

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Open Journal of Nursing 2013年第1期3卷 25-32页

作者： melba Sheila D’Souza Ramesh Venkatesaperumal Jayanthi Radhakrishnan Shreedevi Balachandran Department of Adult Health and Critical Care College of Nursing Sultan Qaboos University Muscat Oman

Student engagement in a clinical learning environment is a vital component in the curricula of pre-licensure nursing students, providing an opportunity to combine cognitive, psychomotor, and affective skills. This paper is significant in Arab world as there is a lack of knowledge, attitude and practice of student involvement in the new clinical learning environment. The purpose of this review article is to describe the experiences and perspectives of the nurse educator in facilitating pre-licensure nursing students’ engagement in the new clinical learning environment. The review suggests that novice students prefer actual engagement in clinical learning facilitated through diversity experiences, shared learning opportunities, student-faculty interaction and active learning. They expressed continuous supervision, ongoing feedback, interpersonal relationship and personal support from nurse educators useful in the clinical practice. However, the value of this review lies in a better understanding of what constitutes quality clinical learning environment from the students’ perspective of engagement in evidence-based nursing, reflective practice, e-learning and simulated case scenarios facilitated by the nurse educators. This review is valuable in planning and implementing innovative clinical and educational experiences for improving the quality of the clinical teaching-learning environment.

关键词： Nursing Student Engagement Clinical Learning Environment Assessment Learning Experiences Nurse Educator Student Centered Learning Teaching-Learning Environment

An Improved Hybrid Space Vector PWM Technique for IM Drives

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Circuits and Systems 2016年第9期7卷 2120-2131页

作者： P. Muthukumar P. melba Mary S. Jeevananthan Sree Sastha Institute of Engineering and Technology Chennai India VV College of Engineering Tisaiyanvilai India Anna University Chennai India Pondicherry Engineering College Pondicherry University India

In this paper, an improved hybrid space vector pulse width modulation (HSVPWM) technique is proposed for IM (induction motor) drives. The basic principle involved in the proposed random pulse width modulation (RPWM) cuddled SVPWM is amalgamating the pre-calculated switching timings for various sections of hexagonal space vector boundary and the random selection of carrier between two triangular signals, in order to disband acoustic switching noise spectrum with improved fundamental component. The arbitrary selection between triangular carriers, which is decided by digital signal states (Low or High) of the linear feedback shift register (LFSR) based pseudo random binary sequence (PRBS) generator. The SVPWM offers a control degree of freedom in terms of positioning of vectors inside every sampling interval and hence it has six possible variants of the voltage vectors arrangements in each sector. The developed HSVPWM is thoroughly analyzed in using the MATLAB? based simulation for all SVPWM variants. From the simulation and experimental results viz. harmonic spectrum, harmonic spread factor (HSF), total harmonic distortion (THD) etc., and the superiority of the proposed scheme such as better utilization of DC bus and the randomization of the harmonic power are evidenced. For the practical implementation, Xilinx XC3S500E FPGA device has been used.

关键词： Harmonic Spread Factor Hybrid Space Vector Pulse Width Modulation Pseudo Random Binary Sequence Random Pulse Width Modulation

Exploring fracture risk factors among Omani women: Implications for risk assessment

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Open Journal of Nursing 2012年第4期2卷 365-371页

作者： melba Sheila D’Souza Chandrani Isac Ramesh Venkatesaperumal Anandhi Amirtharaj Anitha Thanka Shreedevi Balachandran Huda Al Noumani Department of Adult Health and Critical Care College of Nursing Sultan Qaboos University Muscat Sultanate of Oman

Osteoporosis is common among postmenopausal women, giving rise to morbidity and diminishing the quality of life. There is lack of information about the risk factors of Osteoporosis among local Omani women. The aim was to explore the risk factors of Osteoporosis among Omani women using a Modified Fracture Risk Assessment Tool. This is an exploratory research design using a simple random sampling. A pilot study was conducted among 35 local Omani women from the Muscat region, who completed the validated and reliable Modified Fracture Risk Assessment Tool (MFRAT). Bone Mineral Density (BMD) was measured among 11 women at moderate-high risk based on MFRAT. The data was analyzed using inferential statistics. Fourteen Omani women were at moderate-high risk for Osteoporotic fracture due to factors related premenopausal, Vitamin D deficiency, increased parity, increased lactation period and sedentary lifestyle. Among these five women had low BMD and required early intervention and support. Determinants of Osteoporosis can be assessed among premenopausal Omani women with a specific risk assessment tool. There is a need to construct a culturally sensitive risk assessment tool for Omani women for early screening and detection of Osteoporosis. Nurses can identify, provide intervention and education for Omani women at-risk of fracture.

关键词： Fracture Risk Assessment Osteoporosis Osteopenia Omani Women Early Identification Early Screening Bone Mineral Density Nursing Care Primary Prevention

Assessment of Physical Characteristics of Bugang River Watershed in Pandan, Antique, Philippines

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Open Journal of Ecology 2022年第6期12卷 360-376页

作者： melba L. Raga-as Roberto L. Saladar Jerson C. Calaguio Raffy L. Tano Glaiza Mae C. Unlayao College of Agriculture Forestry and Environmental Science Aklan State University (Banga Campus) Aklan Philippines

Sustainable and appropriate watershed management strategies require the determination of biophysical information which includes the floral characteristics of the watershed. This study was conducted to characterize the floral composition of the Bugang River watershed. Data gathering was done by conducting an inventory for trees, palms, and bamboos with Quadrant Sampling using a stratified random sampling method in the forested area of the watershed with 50 m × 20 m sampling plots. Floral species were identified and classified through local experts, published books, journals, the internet, and available references. A total of 60 species belonging to 31 families and 52 genera were found using this method. Gogo (Entada phaseoloides) had the highest number of species with 222 or 14% of the total species. Trees with dbh 10 cm and above have a total estimated volume of 102.31 m3. The average diameter and average height of species decrease as the elevation increases. The result showed that the Bugang River watershed has a diverse floral composition, with vertical stratification and a dense canopy. The advocacy and awareness campaign should be done and strengthen the protection and conservation efforts of concerned agencies for the sustainability of the watershed.

关键词： Barangay Pandan Floral Characteristics Watershed Stratification Antique Philippines

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