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Brain microbleeds are increased in chronic kidney disease (CKD) and their presence increases risk of cognitive decline and stroke. We examined the interaction between CKD and brain microhemorrhages (the neuropathological substrate of microbleeds) in mouse and cell culture models and studied progression of microbleed burden on serial brain imaging from humans. Mouse studies: Two CKD models were investigated: adenine-induced tubulointerstitial nephritis and surgical 5/6 nephrectomy. Cell culture studies: bEnd.3 mouse brain endothelial cells were grown to confluence, and monolayer integrity was measured after exposure to 5-15% human uremic serum or increasing concentrations of urea. Human studies: Progression of brain microbleeds was evaluated on serial MRI from control, pre-dialysis CKD, and dialysis patients. Microhemorrhages were increased 2-2.5-fold in mice with CKD independent of higher blood pressure in the 5/6 nephrectomy model. IgG staining was increased in CKD animals, consistent with increased blood-brain barrier permeability. Incubation of bEnd.3 cells with uremic serum or elevated urea produced a dose-dependent drop in trans-endothelial electrical resistance. Elevated urea induced actin cytoskeleton derangements and decreased claudin-5 expression. In human subjects, prevalence of microbleeds was 50% in both CKD cohorts compared with 10% in age-matched controls. More patients in the dialysis cohort had increased microbleeds on follow-up MRI after 1.5 years. CKD disrupts the blood-brain barrier and increases brain microhemorrhages in mice and microbleeds in humans. Elevated urea alters the actin cytoskeleton and tight junction proteins in cultured endothelial cells, suggesting that these mechanisms explain (at least in part) the microhemorrhages and microbleeds observed in the animal and human studies.

The objective of this study is to assess the effectiveness of a stroke clinic in stroke prevention and progression of cerebral microbleeds (CMB). We conducted a retrospective observational study of patients who visited a stroke clinic between January 2011 and March 2017. Susceptibility-weighted imaging (SWI) MRI studies were obtained at baseline and follow-up visits to identify new infarctions and CMB progression. Patients with CMB who also underwent brain computed tomography (CT) imaging were identified and their cerebral arterial calcification was quantified to evaluate the relationship between the extent of intracranial calcification and CMB burden. A total of 64 stroke patients (mean age 73.1 ± 11.0, 47% males) had CMB on baseline and follow-up MRI studies. During a mean follow-up period of 22.6 months, four strokes occurred (4/64, 6%; 3 ischemic, 1 hemorrhagic), producing mild neurological deficit. Progression of CMB was observed in 54% of patients with two MRIs and was significantly associated with length of follow-up. Subjects with intracranial calcification score > 300 cm3 had higher CMB count than those with scores

The objective of this study is to assess the effectiveness of a stroke clinic in stroke prevention and progression of cerebral microbleeds (CMB). We conducted a retrospective observational study of patients who visited a stroke clinic between January 2011 and March 2017. Susceptibility-weighted imaging (SWI) MRI studies were obtained at baseline and follow-up visits to identify new infarctions and CMB progression. Patients with CMB who also underwent brain computed tomography (CT) imaging were identified and their cerebral arterial calcification was quantified to evaluate the relationship between the extent of intracranial calcification and CMB burden. A total of 64 stroke patients (mean age 73.1 ± 11.0, 47% males) had CMB on baseline and follow-up MRI studies. During a mean follow-up period of 22.6 months, four strokes occurred (4/64, 6%; 3 ischemic, 1 hemorrhagic), producing mild neurological deficit. Progression of CMB was observed in 54% of patients with two MRIs and was significantly associated with length of follow-up. Subjects with intracranial calcification score > 300 cm3 had higher CMB count than those with scores

Summary This article narrates a robust sensor‐less indirect rotor field‐oriented control (IRFOC) of a six‐phase asymmetrical induction motor (SPAIM) drive with an online estimation of parameters and reduction of common mode voltage (CMV). In comparison to the conventional IRFOC technique, the proposed IRFOC provides the least CMV using modified space vector modulation (SVM). To guarantee proper operation of IRFOC, accurate estimation of rotor time constant is mandatory; any mismatch in the actual and tuned value may lead to poor performance of the IRFOC algorithm. This problem will be further accelerated with encoder‐less control using model‐based estimators. In this manuscript, the problem of simultaneous estimation of speed and machine parameters is investigated, and a model reference adaptive system (MRAS) based speed estimator accompanied by online estimation of parameters is proposed to improve sturdiness against variation of parameters. A Simulink model of the proposed method is developed and a simulation study is carried out. To validate the simulation results, a scaled prototype model of The SPAIM rated for 2 HP, 200 V is developed and encoder‐less IRFOC for the SPAIM drives is implemented using an STM32F407VG controller board. The performance of the proposed observers is tested and verified for all the possible operating conditions and results are presented. [ABSTRACT FROM AUTHOR]

In view of the attractive features like improved torque density, reduction torque pulsation, superior fault tolerance, reduced power rating of voltage source converter, and sterling noise characteristics of six-phase asymmetrical induction motor (SPAIM) as compared to its three-phase counterpart, the SPAIM is considered for the study. In this paper, mathematical modelling of SPAIM is carried out in the synchronous reference frame and then indirect rotor field-oriented control (IRFOC) of SPAIM using a modified carrier wave-based space vector modulation (SVM) scheme is developed. A Simulink model of the proposed system configuration is developed and a simulation study is carried out. In order to validate the simulation results, a scaled prototype model of SPAIM rated for 2 HP, 4-pole, 200V is developed, and closed loop control of SPAIM drive with aforesaid modified SVM technique is implemented using TMS320F28379D controller board. The performance of the system is observed in several operating conditions with simulation studies using MATLAB/Simulink and test setup and various test results are recorded under several operating conditions and presented. Furthermore, the proposed SVM technique is compared with benchmarked SPWM and hysteresis current controller as well and it is observed that it outperforms traditional SPWM and hysteresis-based current controllers in terms of the distortion of stator currents and torque ripples. [ABSTRACT FROM AUTHOR]

Increasing the carbon emission in environment has become a major concern for the government. For promoting a clean and green environment with reduction in carbon emission by vehicles, the Government of India aspires with 100 percent electric passenger vehicle mobility by the year 2030 in the country. There is an essential requirements for fast charging stations to meet this demand as large numbers of electric vehicles to be running on the roads. In this paper, we review the state of the art in electric vehicles (EVs) charging topologies which will be necessary to support future EV refueling. Some power converter topologies are also reviewed appropriate to deliver the fast charging. DC-DC universal converter is unified converter for charging the battery and power management on buck/boost plugin operations of EVs. SiC and GaN devices are attractive to be used in the fast charging due to lower switching loss, faster switching frequency and higher operating temperature. [ABSTRACT FROM AUTHOR]