1,111 research outputs found

    Development of 100W Solid State Power Amplifier at 13.56?1MHz

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    Project aim is the development of a common source class B, cwrf amplifier by using MOSFET. The work includes literature survey, concept, simulation, design, fabrication and testing of the power amplifier. This single stage amplifier of more than 100W output and gain 13dB needs development in the frequency range of 13.56?1MHz. A temperature sensor at the heat sink mounting must be added along with necessary wiring to switch off the dc supply and thereby protecting the circuit in case of overheating. The ultimately developed amplifier needs testing for the frequency response, power gain and output wave shapes etc. by using a set of appropriate instruments

    Some Common Random Fixed Point Results for Expansive Mappings in a Cone Metric Space

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    The purpose of this work is to extend and generalize some common random fixed point theorems for Expansive type mappings in complete cone metric spaces. We are attempting to generalize the several well- known recent results. Key wards: common fixed point, cone metric space, random variabl

    Effects of Usnic Acid on Hyperglycemia and Renal Function in Streptozotocin-Induced Diabetic Rats

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    Background: Diabetic hyperglycemia and glomerular hyper filtration play a causative role in the progression of chronic kidney disease. Renal glucose handling via Sodium-Glucose Cotransporter (SGLT)-2 is a targetable approach and SGLT-2 inhibitors have proven therapeutic benefits in diabetic kidney disease. Usnic Acid (UA) is an active constituent of lichen species and symbiotic organism of algae and fungi, which is variously studied in folk medicine. The objective of this study was to demonstrate the beneficial effects of UA on glucose homeostasis and renal function in streptozotocin-induced diabetic Sprague-Dawley rats and to determine whether UA has an effect on regulation of SGLT that may further aid in glucoregulation and renal function. Methods: Type 1 diabetes was induced in Sprague-Dawley rats with Streptozotocin (STZ, 60mg/kg) by intraperitoneal route on day 0. Diabetic rats were treated with UA (75 mg/kg) from day 15 to 35 via oral gavage. On day 35, urine was collected and Oral Glucose Tolerance Test (OGTT) was performed. After OGTT, blood was collected through cardiac puncture and kidneys were preserved for biochemical analysis. The results are expressed as mean ± standard error of the mean for n=8 rats per study group. The data were subjected to 1-way or 2-way ANOVA with Bonferroni’s multiple comparison post hoc test using Graph Pad Prism 5 and were considered significant at p≤0.05. Results: Diabetic rats chronically treated with UA had improved hyperphagia, hyperglycemia and glucose intolerance, glomerular hyper filtration, and urinary protein excretion (p\u3c0.05). However, UA did not prevent loss of circulating insulin in diabetic rats. UA’s blood glucose lowering effect was associated with enhanced diuretic-glucosuric response and decreased protein expression of renal SGLT-1 (p\u3c0.05). While protein expression of SGLT-2 was partially increased in the diabetic kidney and it was not decreased by UA. Metabolic corrections with UA treatment occurred in parallel with reductions in uremia and improvement of renal function indices. Additionally, in diabetic rat kidney, UA treatment corrected oxidative changes. Conclusions: Based on preliminary findings we conclude that chronic treatment of UA may act in an insulin-independent manner in lowering of diabetic hyperglycemia and improvement of renal function

    Diuretic, Glucosuric and Natriuretic Effect of Pantoyltaurine in Diabetic Sprague-Dawley Rats

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    Sodium-glucose co-transporter (SGLT) inhibitors offer a novel tool to control hyperglycemia and its complications. We present preliminary findings of pantoyltaurine, N-substituted analog of taurine, as diuretic, glucosuric and natriuretic agent in streptozotocin (60 mg/kg/mL, i.p.)-induced type 1 diabetic Sprague-Dawley rats and whether pantoyltaurine has an effect on regulation of SGLT isoforms that may further help in reducing hyperglycemia and improving renal function. After 14 days of persistent diabetes, phlorizin (0.4 g/kg/day, s.c.) or pantoyltaurine (2.4 mM/kg/day, p.o.) was administered for three weeks, days 15 - 35. As expected, diabetic rats showed persistent hyperglycemia, hyperphagia and weight loss. Pantoyltaurine and phlorizin-treated diabetic rats consumed less diet, showed significant weight loss, reduced persistent hyperglycemia as well as reduced glucose load after oral glucose tolerance test. Diuretic, glucosuric and natriuretic response of diabetic rats was enhanced by pantoyltaurine independent of renal and plasma oxidative stress, plasma insulin and renal expression of SGLT-2. Phlorizin and pantoyltaurine reduced renal expression of SGLT-1, which accounts for ≤ 10% of glucose reabsorption. However, pantoyltaurine, but not phlorizin, normalized elevated fractional excretion of urea nitrogen and clearance of blood urea nitrogen in diabetic rats, suggesting lessening effect of pantoyltaurine on uremic toxicity associated with diabetes. Collectively, our preliminary findings show that chronic treatment with pantoyltaurine may help in an insulin-independent manner to lower diabetic hyperglycemia by producing diuresis, glucosuria and natriuresis that may have translated in improvement of renal function

    Long-term outcomes of ranibizumab therapy for diabetic macular edema: the 36-month results from two phase III trials: RISE and RIDE.

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    PURPOSE: To report 36-month outcomes of RIDE (NCT00473382) and RISE (NCT00473330), trials of ranibizumab in diabetic macular edema (DME). DESIGN: Phase III, randomized, multicenter, double-masked, 3-year trials, sham injection-controlled for 2 years. PARTICIPANTS: Adults with DME (n=759), baseline best-corrected visual acuity (BCVA) 20/40 to 20/320 Snellen equivalent, and central foveal thickness (CFT) ≥ 275 μm on optical coherence tomography. METHODS: Patients were randomized equally (1 eye per patient) to monthly 0.5 mg or 0.3 mg ranibizumab or sham injection. In the third year, sham patients, while still masked, were eligible to cross over to monthly 0.5 mg ranibizumab. Macular laser was available to all patients starting at month 3; panretinal laser was available as necessary. MAIN OUTCOME MEASURES: The proportion of patients gaining ≥15 Early Treatment Diabetic Retinopathy Study letters in BCVA from baseline at month 24. RESULTS: Visual acuity (VA) outcomes seen at month 24 in ranibizumab groups were consistent through month 36; the proportions of patients who gained ≥15 letters from baseline at month 36 in the sham/0.5 mg, 0.3 mg, and 0.5 mg ranibizumab groups were 19.2%, 36.8%, and 40.2%, respectively, in RIDE and 22.0%, 51.2%, and 41.6%, respectively, in RISE. In the ranibizumab arms, reductions in CFT seen at 24 months were, on average, sustained through month 36. After crossover to 1 year of treatment with ranibizumab, average VA gains in the sham/0.5 mg group were lower compared with gains seen in the ranibizumab patients after 1 year of treatment (2.8 vs. 10.6 and 11.1 letters). Per-injection rates of endophthalmitis remained low over time (∼0.06% per injection). The incidence of serious adverse events potentially related to systemic vascular endothelial growth factor inhibition was 19.7% in patients who received 0.5 mg ranibizumab compared with 16.8% in the 0.3 mg group. CONCLUSIONS: The strong VA gains and improvement in retinal anatomy achieved with ranibizumab at month 24 were sustained through month 36. Delayed treatment in patients receiving sham treatment did not seem to result in the same extent of VA improvement observed in patients originally randomized to ranibizumab. Ocular and systemic safety was generally consistent with the results seen at month 24. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references

    Efficacy and safety of avacincaptad pegol in patients with geographic atrophy (GATHER2) : 12-month results from a randomised, double-masked, phase 3 trial

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    Geographic atrophy is an advanced form of dry age-related macular degeneration that can lead to irreversible vision loss and high burden of disease. We aimed to assess efficacy and safety of avacincaptad pegol 2 mg in reducing geographic atrophy lesion growth.GATHER2 is a randomised, double-masked, sham-controlled, 24-month, phase 3 trial across 205 retina clinics, research hospitals, and academic institutions globally. To be eligible, patients had to be aged 50 years or older with non-centrepoint-involving geographic atrophy and best corrected visual acuity between 20/25 and 20/320 in the study eye. Eligible patients were randomly assigned (1:1) to monthly avacincaptad pegol 2 mg administered as a 100 μL intravitreal injection or sham for the first 12 months. Randomisation was performed using an interactive response technology system with stratification by factors known to be of prognostic importance in age-related macular degeneration. Patients, investigators, study centre staff, sponsor personnel, and data analysts were masked to treatment allocation. The primary endpoint was geographic atrophy lesion size measured by fundus autofluorescence at baseline, month 6, and month 12. Efficacy and safety analyses were done in the modified intention-to-treat and safety populations, respectively. This trial is registered with ClinicalTrials.gov, NCT04435366.Between June 22, 2020, and July 23, 2021, 1422 patients were screened for eligibility, of whom 448 were enrolled and randomly assigned to avacincaptad pegol 2 mg (n=225) or sham (n=223). One patient in the sham group did not receive study treatment and was excluded from analyses. There were 154 (68%) female patients and 71 (32%) male patients in the avacincaptad pegol 2 mg group, and 156 (70%) female patients and 66 (30%) male patients in the sham group. From baseline to month 12, the mean rate of square-root-transformed geographic atrophy area growth was 0·336 mm/year (SE 0·032) with avacincaptad pegol 2 mg and 0·392 mm/year (0·033) with sham, a difference in growth of 0·056 mm/year (95% CI 0·016-0·096; p=0·0064), representing a 14% difference between the avacincaptad pegol 2 mg group and the sham group. Ocular treatment-emergent adverse events in the study eye occurred in 110 (49%) patients in the avacincaptad pegol 2 mg group and 83 (37%) in the sham group. There were no endophthalmitis, intraocular inflammation, or ischaemic optic neuropathy events over 12 months. To month 12, macular neovascularisation in the study eye occurred in 15 (7%) patients in the avacincaptad pegol 2 mg group and nine (4%) in the sham group, with exudative macular neovascularisation occurring in 11 (5%) in the avacincaptad pegol 2 mg group and seven (3%) in the sham group.Monthly avacincaptad pegol 2 mg was well tolerated and showed significantly slower geographic atrophy growth over 12 months than sham treatment, suggesting that avacincaptad pegol might slow disease progression and potentially change the trajectory of disease for patients with geographic atrophy.Iveric Bio, An Astellas Company

    Aggressive breast cancer in western Kenya has early onset, high proliferation, and immune cell infiltration

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    Background Breast cancer incidence and mortality vary significantly among different nations and racial groups. African nations have the highest breast cancer mortality rates in the world, even though the incidence rates are below those of many nations. Differences in disease progression suggest that aggressive breast tumors may harbor a unique molecular signature to promote disease progression. However, few studies have investigated the pathology and clinical markers expressed in breast tissue from regional African patient populations. Methods We collected 68 malignant and 89 non-cancerous samples from Kenyan breast tissue. To characterize the tumors from these patients, we constructed tissue microarrays (TMAs) from these tissues. Sections from these TMAs were stained and analyzed using immunohistochemistry to detect clinical breast cancer markers, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 receptor (HER2) status, Ki67, and immune cell markers. Results Thirty-three percent of the tumors were triple negative (ER-, PR-, HER2-), 59 % were ER+, and almost all tumors analyzed were HER2-. Seven percent of the breast cancer patients were male, and 30 % were <40 years old at diagnosis. Cancer tissue had increased immune cell infiltration with recruitment of CD163+ (M2 macrophage), CD25+ (regulatory T lymphocyte), and CD4+ (T helper) cells compared to non-cancer tissue. Conclusions We identified clinical biomarkers that may assist in identifying therapy strategies for breast cancer patients in western Kenya. Estrogen receptor status in particular should lead initial treatment strategies in these breast cancer patients. Increased CD25 expression suggests a need for additional treatment strategies designed to overcome immune suppression by CD25+ cells in order to promote the antitumor activity of CD8+ cytotoxic T cells

    Novel insights into the cardio-protective effects of FGF21 in lean and obese rat hearts

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    Aims: Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia. Methods and Results: FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased. Conclusion: In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia

    Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study.

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    PurposeOsteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI.MethodsUsing data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves.ResultsIn children, the median z-scores for height in OI types I, III, and IV were -0.66, -6.91, and -2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was -4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P &lt; 0.001), age, bisphosphonate use, and rodding (P &lt; 0.05).ConclusionFrom the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves
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