Mismatched Load Protected Solid State Amplifier of 1W CWRF Output in Frequency Range of 28 - 46 MHz

This project work is associated with the concept, design, fabrication and testing of a continuous wave radio frequency (cwrf) solid state amplifier. This amplifier of gain more than 20dB with 10mW input, will be developed for general application in the frequency range of 28 to 46 MHz. This Low Power Amplifier (LPA) will be made to exhibit a feature of protection from finite mismatched load that causes Voltage Standing Wave Ratio (VSWR) and consequent failure of the solid state device. The rf and microwave circuits including amplifiers are designed for standard 50 transmission line components and load. In case of perfectly matched load, only incident waves exist without any reflection i.e. 1:1 VSWR and maximum power is transferred to the load. In practice, mismatched load persists where reflected waves along with the forward waves gives rise to standing waves that cause damage to the solid state devices due to various reasons. In order to protect the device, the amplifier to be developed, will be treated with various protections so that load mismatch is managed in the most optimised manner. DOI: 10.17762/ijritcc2321-8169.15056

“Time is brain”- management of the patient with iatrogenic intracerebral hemorrhage

The brain is a critical organ of our body, which depends on a continuous supply of oxygen and glucose for normal functioning. An inadequate supply of oxygen and glucose can trigger a characteristic pathophysiological cascade leading to neuronal death. Multiple neuroprotective strategies have been developed blocking one or more steps along this cascade. Here, we report the case of an intracerebral hemorrhage during neurointerventional procedure in a catheterization laboratory. Accurate decision and timely intervention of neuroprotective strategies resulted in the complete neurological recovery of the patient

Large-scale screening of clinical assessments to distinguish between states in the Integrated HD Progression Model (IHDPM)

BackgroundUnderstanding the sensitivity and utility of clinical assessments across different HD stages is important for study/trial endpoint selection and clinical assessment development. The Integrated HD Progression Model (IHDPM) characterizes the complex symptom progression of HD and separates the disease into nine ordered disease states.ObjectiveTo generate a temporal map of discriminatory clinical measures across the IHDPM states.MethodsWe applied the IHDPM to all HD individuals in an integrated longitudinal HD dataset derived from four observational studies, obtaining disease state assignment for each study visit. Using large-scale screening, we estimated Cohen’s effect sizes to rank the discriminative power of 2,472 clinical measures for separating observations in disease state pairs. Individual trajectories through IHDPM states were examined. Discriminative analyses were limited to individuals with observations in both states of the pairs compared (N = 3,790).ResultsDiscriminative clinical measures were heterogeneous across the HD life course. UHDRS items were frequently identified as the best state pair discriminators, with UHDRS Motor items – most notably TMS – showing the highest discriminatory power between the early-disease states and early post-transition period states. UHDRS functional items emerged as strong discriminators from the transition period and on. Cognitive assessments showed good discriminative power between all state pairs examined, excepting state 1 vs. 2. Several non-UHDRS assessments were also flagged as excellent state discriminators for specific disease phases (e.g., SF-12). For certain state pairs, single assessment items other than total/summary scores were highlighted as having excellent discriminative power.ConclusionBy providing ranked quantitative scores indicating discriminatory ability of thousands of clinical measures between specific pairs of IHDPM states, our results will aid clinical trial designers select the most effective outcome measures tailored to their study cohort. Our observations may also assist in the development of end points targeting specific phases in the disease life course, through providing specific conceptual foci

Safety and Feasibility of Research Lumbar Puncture in Huntington’s Disease: The HDClarity Cohort and Bioresource

Background: Biomarkers are needed to monitor disease progression, target engagement and efficacy in Huntington’s disease (HD). Cerebrospinal fluid (CSF) is an ideal medium to research such biomarkers due to its proximity to the brain. Objective: To investigate the safety and feasibility of research lumbar punctures (LP) in HD. Methods: HDClarity is an ongoing international biofluid collection initiative built on the Enroll-HD platform, where clinical assessments are recorded. It aims to recruit 1,200 participants. Biosamples are collected following an overnight fast: blood via venipuncture and CSF via LP. Participants are healthy controls and HD gene expansion carriers across the disease spectrum. We report on monitored data from February 2016 to September 2019. Results: Of 448 participants screened, 398 underwent at least 1 sampling visit, of which 98.24% were successful (i.e., CSF was collected), amounting to 10,610 mL of CSF and 8,200 mL of plasma. In the total 572 sampling visits, adverse events were reported in 24.13%, and headaches of any kind and post-LP headaches in 14.86% and 12.24%, respectively. Frequencies were less in manifest HD; gender, age, body mass index and disease burden score were not associated with the occurrence of the events in gene expansion carriers. Headaches and back pain were the most frequent adverse events. Conclusion: HDClarity is the largest CSF collection initiative to support scientific research into HD and is now stablished as a leading resource for HD research. Our data confirm that research LP in HD are feasible and acceptable to the community, and have a manageable safety profile

Oral and salivary changes in patients with chronic kidney disease: A clinical and biochemical study

Background: Both chronic kidney disease (CKD) and its treatment can affect a wide range of tissues and systems. It directly or indirectly affects flow, concentrations and composition of saliva. Hemodialysis can effectively minimize most of these complications to some extent. Aims: The main aim of this study was to know the salivary content of sodium, potassium, calcium, urea, bicarbonate and oral manifestations in patients with CKD. Subjects and Methods: For this study, 50 patients diagnosed with CKD and 50 systemically and periodontally healthy individuals were subjected to a detailed general and intraoral examination. Whole un-stimulated saliva samples of all the selected subjects were collected and subjected to calcium (Ca), phosphorous (P), sodium (Na), potassium (K), bicarbonate and urea analysis. Statistical Analysis Used: Paired t-test, Mann-Whitney test. Results: Among 50 study subjects, 26 subjects had reduced salivary flow in the range of 0.1-0.4 ml/min. Intraoral examination of the study subjects revealed pallor, increased deposition of calculus, bleeding gums, metallic taste, hypoplasia of teeth and fissured tongue. There was a significant difference between healthy and prehemodialysis patients in the salivary sodium, potassium, calcium, phosphorus, urea levels and the difference was insignificant in relation to bicarbonate levels. Conclusions: Alterations in salivary calcium, phosphorous, urea, sodium, potassium levels were significantly higher in the study groups when compared to control groups and the difference was insignificant in relation to bicarbonate level. The increased levels in dialysis patients correlated with renal disease severity

Head trauma can initiate the onset of adreno-leukodystrophy

X-linked adreno-leukodystrophy and its adult variant, adrenomyeloneuropathy, are caused by mutations in ABCD1 that encodes a peroxisomal membrane protein of unknown physiological significance. In spite of identical mutations, they can have markedly divergent neurological and neuropathologic characteristics. Adreno-leukodystrophy classically presents in normal boys with mild neuropsychiatric features, which progress to frank neurological signs, the vegetative state and death in approximately three years. Adrenomyeloneuropathy typically affects young men with spastic paraparesis and sensory ataxia that can progress over decades. The neuropathologic correlate for adreno-leukodystrophy is severe inflammatory demyelination of posterior cerebral white matter, while a chronic distal axonopathy of spinal cord and peripheral nerve occurs in adrenomyeloneuropathy. Consequently, both modifier genes and environmental factors have been implicated in their pathogeneses. We report five cases of adreno-leukodystrophy whose onsets were initiated by moderate to severe head trauma, two of whom were conversions from adrenomyeloneuropathy. Their clinical courses were rapidly incapacitating, short (i.e., weeks to a few years) and fatal due to marked cerebral inflammatory demyelination. These cases, in concert with several previous reports, indicate that head trauma is one environmental factor that can have a profoundly deleterious effect on those genetically at risk for, or with milder clinical phenotypes of, this disease. Avoidance of potential head trauma and a rapid response to episodes of moderate to severe head trauma in this patient population seem prudent

Table_2_Large-scale screening of clinical assessments to distinguish between states in the Integrated HD Progression Model (IHDPM).XLSX

BackgroundUnderstanding the sensitivity and utility of clinical assessments across different HD stages is important for study/trial endpoint selection and clinical assessment development. The Integrated HD Progression Model (IHDPM) characterizes the complex symptom progression of HD and separates the disease into nine ordered disease states.ObjectiveTo generate a temporal map of discriminatory clinical measures across the IHDPM states.MethodsWe applied the IHDPM to all HD individuals in an integrated longitudinal HD dataset derived from four observational studies, obtaining disease state assignment for each study visit. Using large-scale screening, we estimated Cohen’s effect sizes to rank the discriminative power of 2,472 clinical measures for separating observations in disease state pairs. Individual trajectories through IHDPM states were examined. Discriminative analyses were limited to individuals with observations in both states of the pairs compared (N = 3,790).ResultsDiscriminative clinical measures were heterogeneous across the HD life course. UHDRS items were frequently identified as the best state pair discriminators, with UHDRS Motor items – most notably TMS – showing the highest discriminatory power between the early-disease states and early post-transition period states. UHDRS functional items emerged as strong discriminators from the transition period and on. Cognitive assessments showed good discriminative power between all state pairs examined, excepting state 1 vs. 2. Several non-UHDRS assessments were also flagged as excellent state discriminators for specific disease phases (e.g., SF-12). For certain state pairs, single assessment items other than total/summary scores were highlighted as having excellent discriminative power.ConclusionBy providing ranked quantitative scores indicating discriminatory ability of thousands of clinical measures between specific pairs of IHDPM states, our results will aid clinical trial designers select the most effective outcome measures tailored to their study cohort. Our observations may also assist in the development of end points targeting specific phases in the disease life course, through providing specific conceptual foci.</p