2,933 research outputs found

    Electrical parameters extraction of CMOS floating-gate inverters

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    This work provides an accurate methodology for extracting the floating-gate gain factory, of CMOS floating-gate inverters with a clock-driven switch for accessing temporarilly to the floating-gate. With the methodology proposed in this paper, the γ factor and other parasitic capacitances coupled to the floating-gate can be easily extracted in a mismatch-free approach. This parameter plays an important role in modern analog and mixed-signal CMOS circuits, since it limits the circuit performance. Theoretical and measured values using two test cells, fabricated in a standard double poly double metal CMOS AMI-ABN process with 1.2 µm design rules, were compared. The extracted parameters can be incorporated into floating-gate PS pice macromodels for obtaining accurate electrical simulation

    A low-complexity current-mode WTA circuit based on CMOS Quasi-FG inverters

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    In this paper, a low-complexity current-mode Winner-Take-All circuit (WTA) of O (n) complexity with logical outputs is presented. The proposed approach employs a Quasi-FG Inverter as the key element for current integration and the computing of the winning cell. The design was implemented in a double-poly, three metal layers, 0.5µm CMOS technology. The circuit exhibits a good accuracy-speed tradeoff when compared to other reported WTA architectures

    Increase of Oxidants and Antioxidant Consumption in Patients with Type 2 Diabetes Mellitus in Peritoneal Dialysis

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    Oxidative stress (OS) is implicated as a unifying factor between chronic kidney diseases and cardiovascular diseases. The objective of the study was to compare the oxidant and antioxidant status in patients with PD according to the state of DM. Lipoperoxides (LPO), 8-isoprostanes (8-IP) and nitric oxide (NO) were determined as oxidants and the activity of superoxide dismutase (SOD) and total antioxidant capacity (TAC) as antioxidants in patients with DM and without DM (No-DM). We included 35 patients with DM, 42 No-DM patients and 10 healthy people as a control group (HC). Patients with DM were older (p<0.0001), had higher BMI (p<0.0001), high glucose levels (p<0.0001) and more hypertension (p<0.0001). It was found that LPO levels increased in patients with DM and No-DM vs. HC (p<0.0001). There was a decrease in the levels of 8-IP in DM and No-DM compared to HC (p<0.0001). The levels of NO in patients with DM and No-DM decreased significantly compared to the HC group with 197.97±34.20 μM (p<0.0001). The activity of the SOD enzyme in patients with DM and No-DM was found to be increased compared to the HC group (p<0.0001). The levels of TAC in HC were 2.62±0.17 mM and decreased in patients with DM and No-DM (p<0.0001)

    Effects of Jejunal Manipulation During Surgical Laparotomy Techniques and Its Evaluation Using Physical, Clinical, and Echographic Parameters in Horses

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    The laparotomy surgical procedure allows for the identification and correction of intestinal lesions associated with acute abdomen in horses. The clinician relies on various laparotomy techniques to diagnose and treat this syndrome, and to date, the postsurgical effects of these techniques have not been clarified. The aim of this study was to evaluate the effects of jejunal manipulation during three laparotomy techniques through physical and clinical parameters and echography. Fifteen healthy horses were randomly assigned to three groups: animals in G1 (n 1⁄4 5) were subjected to an exploratory laparotomy, animals in G2 (n 1⁄4 5) to a laparotomy with an enterotomy, and animals in G3 (n 1⁄4 5) to a laparotomy with an enterectomy. Degree of pain, jejunal wall thickness, and clinical parameters were evaluated before and after surgery. Horses in G3 had higher heart rates, respiratory frequency, degree of pain, and je- junal wall thickness compared with G1. Clinical variables during the postsurgical period were compared among the laparotomy techniques, and higher values of erythrocytes, leucocytes, neutrophils, and proteins were found in horses belonging to G3 compared to those in G1. Intestinal manipulation during the surgical procedure altered the physical and clinical pa- rameters, as well as the results of the echography evaluation, with more significant effects from laparotomy with enterectomy. In the postsurgical period, the heart rate of horses in G3 was higher (P 1⁄4 .02) than the values obtained in G1 and G2. Upon the evaluation of degree of pain, statistically significant differences (P 1⁄4 .04) were identified between horses in G1 versus G3. G3 animals presented a higher degree of pain. Regarding the erythrocytes (L/L), higher values were measured in G3 (P 1⁄4 .001) in comparison with G1 and G2. These results suggest that meticulous tissue handling is essential to minimize intestinal trauma and inflammation

    Síndrome de fatiga crónica en una adolescente de 15 años

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    Fatigue and lack of energy are frequent symptoms in children and adolescents. A diagnosis of chronic fatigue syndrome should be considered in children and adolescents who complain of chronic fatigue associated with other symptoms without a demonstrable physical cause. Lack of knowledge about this syndrome and late diagnosis may have a negative impact on the normal development of affected children and adolescents. Treatment should be based on a rehabilitation program with cognitive behavioral therapy and a gradual increase in activities

    Neuroprotective effects of PGC-1α activators in dopaminergic neurons

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    M1 - 93 s. + liitteet Helsingin yliopistoNeurodegenerative diseases are characterized by the progressive loss of structure and function of neurons, but the underlying mechanisms for this are largely unknown. Disturbed cell signaling and protein metabolism as well as mitochondrial dysfunctions are thought to be involved in several neurodegenerative diseases. Mitochondria are the major source of energy in the cell, and they also regulate cell death. In brain, neurons are highly dependent on oxidative energy metabolism. Mitochondrial dysfunctions cause oxidative stress with an excess production of reactive oxygen species (ROS). In neurodegenerative diseases such as Parkinson s disease (PD), ROS are thought to contribute to the loss of dopaminergic neurons in substantia nigra pars compacta (SNpc), which leads to dopamine depletion in striatum. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a transcriptional co-activator that regulates mitochondrial biogenesis, ROS defense and respiration. The lack of PGC-1α has been shown to increase the sensitivity of neurons to oxidative stress and brain injuries. In this study we show that increasing the expression of PGC-1α protects against toxin-induced oxidative stress in dopaminergic neurons. We show that PGC-1α expression in dopaminergic neurons can be modulated by resveratrol (RSV), fibroblast growth factor 21 (FGF21) and peroxisome proliferator- activated receptor γ (PPARγ) that are known to regulate metabolism in other tissues. The increase in PGC-1α expression and activation was linked to metabolic changes mimicing low energy levels in the cell, and an increase in SIRT1, a metabolic regulator sensing changes in energy levels. PGC-1α activation was further associated with an increase in mitochondrial respiration and antioxidant levels suggesting that the neuroprotective effect of PGC-1α was due to an improved capacity to combat oxidative stress. These results show that regulation of metabolism by PGC-1α activators could be a useful tool to prevent neurodegeneration in PD. In addition to modulating PGC-1α, RSV was also found to increase the expression of dopamine transporter (DAT) in dopaminergic neurons of female mice. The increase in the level of DAT increases the uptake of dopamine, further indicating that RSV has beneficial effects in dopaminergic neurons. By affecting DAT, RSV also contributes to maintaining functional neurons, as a decline in DAT has been associated with degeneration of dopaminergic neurons. This effect on DAT expression was mediated by estrogen receptors, indicating that the effect of RSV differs between genders that should be considered if RSV is used as therapy for patients with PD

    Itchy Capillary Malformations: Unusual Appearance of Meyerson Phenomenon, a Case Series

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    Meyerson phenomenon, also known as "halo-eczema," has been widely described over melanocytic and non-melanocytic lesions. However, its appearance over vascular anomalies is rarely observed and could lead to diagnostic errors. A case study of five patients aged between four months and two years is reported. These patients developed unique erythematous and pruritic scaly patches, being diagnosed and treated as fungal infections. Due to the lack of response to the treatment, they were referred to the pediatric dermatology practice, where the diagnosis of Meyerson phenomenon over capillary malformations was made. Topical treatment with corticosteroids led to improvement in all cases. Although Meyerson phenomenon developing over vascular anomalies is a rare condition, it is important for pediatricians and dermatologists to assess it as a part of the differential diagnosis when treating a patient with skin lesions. Recognizing this phenomenon will prevent diagnostic and therapeutic errors.Ye
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