1,534 research outputs found

    Investigation of Compact Low Pass Filter with Sharp Cut–Off using Metamaterial

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    In this paper a new compact microstrip Bessel low pass filter (LPF) is experimentally validated using complementary split ring resonator (CSRR) which has sharper cut-off and improved spurious band suppression characteristics. The Richard’s transformation and Kuroda’s identities are used for realizing distributed Bessel LPF from the lumped element Bessel LPF. Traditionally Butterworth and Chebyshev LPFs are used in communication systems. Those LPFs exhibits high reflection in the pass-band and it is also very difficult to achieve sharper cut-off. Because of its poor cut-off and non linear phase characteristics, it will create cross talk between microwave systems. In order to overcome the above issues our proposed LPF which has linear phase and sharper cut-off behavior is on ideal subsystem in future microwave systems. Furthermore, to prove its practical viability of the proposed design, a compact microstrip Bessel LPF was designed, simulated, fabricated and measured. It was observed from the experimentally compared results of the proposed Bessel LPF with CSRR has better sharper cut-off characteristic than the without CSRR structure

    Temporal dynamics of sucking pest and field response of promising insecticidal molecules in okra

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    To investigate the response due to application of newer insecticide on sucking pest in okra, a trial was designed at field level for three consecutive years from 2011-12 to 2013-14 in kharif season. Moreover, impacts of applied insecticides on natural enemies were also assessed. Based on experimental finding thiamethoxam 25WG 0.003% (2.83 per 3 leaves, 0.93 per 3 leaves), imidacloprid 70WG 0.004% (3.49 per 3 leaves, 1.30 per 3 leaves) and thiacloprid 21.7 SC 0.006% (4.28 per 3 leaves, 1.75 per 3 leaves) provided superior control of leafhoppers and whiteflies population on okra. Effectiveness of these treatments was reflected in terms of reduction in population of both insects and significantly increases (thiamethoxam: 95.50 q/ha, imidacloprid: 86.96 q/ha and thiacloprid: 80.99 q/ha) the fruit yield in comparison to others. However, the incidence of Yellow Vein Mosaic disease was recorded least in thiamethoxam 0.003% sprayed plots followed by imidacloprid 0.004%. Slow progress in the population ofwhitefly and leaf hopper was recorded in thiamethoxam 0.003% applied plots. There was positive correlation between whitefly and virus incidence in conducted field trial. Under the experiment, neonicotinoids group of insecticides have not adverse effect on natural enemies in okra crop. The information generated under the study can be incorporated in management modules in crop okra without disturbing the ecology of natural enemy and cropping system. In our findings, the quantitative data of temporal increment of whiteflies and mosaic disease will be helpful in understanding or formulating of epidemiological models

    Digital support interventions for the self-management of low back pain: a systematic review

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    Background: Low back pain (LBP) is a common cause of disability and is ranked as the most burdensome health condition globally. Self-management, including components on increased knowledge, monitoring of symptoms, and physical activity, are consistently recommended in clinical guidelines as cost-effective strategies for LBP management and there is increasing interest in the potential role of digital health. Objective: The study aimed to synthesize and critically appraise published evidence concerning the use of interactive digital interventions to support self-management of LBP. The following specific questions were examined: (1) What are the key components of digital self-management interventions for LBP, including theoretical underpinnings? (2) What outcome measures have been used in randomized trials of digital self-management interventions in LBP and what effect, if any, did the intervention have on these? and (3) What specific characteristics or components, if any, of interventions appear to be associated with beneficial outcomes? Methods: Bibliographic databases searched from 2000 to March 2016 included Medline, Embase, CINAHL, PsycINFO, Cochrane Library, DoPHER and TRoPHI, Social Science Citation Index, and Science Citation Index. Reference and citation searching was also undertaken. Search strategy combined the following concepts: (1) back pain, (2) digital intervention, and (3) self-management. Only randomized controlled trial (RCT) protocols or completed RCTs involving adults with LBP published in peer-reviewed journals were included. Two reviewers independently screened titles and abstracts, full-text articles, extracted data, and assessed risk of bias using Cochrane risk of bias tool. An independent third reviewer adjudicated on disagreements. Data were synthesized narratively. Results: Of the total 7014 references identified, 11 were included, describing 9 studies: 6 completed RCTs and 3 protocols for future RCTs. The completed RCTs included a total of 2706 participants (range of 114-1343 participants per study) and varied considerably in the nature and delivery of the interventions, the duration/definition of LBP, the outcomes measured, and the effectiveness of the interventions. Participants were generally white, middle aged, and in 5 of 6 RCT reports, the majority were female and most reported educational level as time at college or higher. Only one study reported between-group differences in favor of the digital intervention. There was considerable variation in the extent of reporting the characteristics, components, and theories underpinning each intervention. None of the studies showed evidence of harm. Conclusions: The literature is extremely heterogeneous, making it difficult to understand what might work best, for whom, and in what circumstances. Participants were predominantly female, white, well educated, and middle aged, and thus the wider applicability of digital self-management interventions remains uncertain. No information on cost-effectiveness was reported. The evidence base for interactive digital interventions to support patient self-management of LBP remains weak

    Harmonic Reduction in Variable Frequency Drives Using Active Power Filter

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    In this paper Voltage Source Inverter (VSI) is used to supply a variable frequency variable voltage to a three phase induction motor drive in a variable speed application. One important complication is that, Voltage Source Inverter (VSI) used in VFD causes non-sinusoidal output voltage and current due to presence of harmonics. Shunt active filter with VSI topology is proposed for current harmonic elimination. The current control scheme proposed for SAPF is Synchronous Reference Frame theory applied to SVPWM. The reference current can be calculated by using Reference Frame Transformation, reference current are transformed from a−b−c stationary frame to d−q rotating frame. In SVPWM technique, the Active Power Filter reference voltage is generated and desired Active Power Filter output voltage is generated by SVPWM. The analysis of simulation results are carried out in MATLAB/SIMULINK model

    Behaviour of non-donor specific antibodies during rapid re-synthesis of donor specific HLA antibodies after antibody incompatible renal transplantation

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    Background: HLA directed antibodies play an important role in acute and chronic allograft rejection. During viral infection of a patient with HLA antibodies, the HLA antibody levels may rise even though there is no new immunization with antigen. However it is not known whether the converse occurs, and whether changes on non-donor specific antibodies are associated with any outcomes following HLA antibody incompatible renal transplantation. Methods: 55 patients, 31 women and 24 men, who underwent HLAi renal transplant in our center from September 2005 to September 2010 were included in the studies. We analysed the data using two different approaches, based on; i) DSA levels and ii) rejection episode post transplant. HLA antibody levels were measured during the early post transplant period and corresponding CMV, VZV and Anti-HBs IgG antibody levels and blood group IgG, IgM and IgA antibodies were quantified. Results: Despite a significant DSA antibody rise no significant non-donor specific HLA antibody, viral or blood group antibody rise was found. In rejection episode analyses, multiple logistic regression modelling showed that change in the DSA was significantly associated with rejection (p = 0.002), even when adjusted for other antibody levels. No other antibody levels were predictive of rejection. Increase in DSA from pre treatment to a post transplant peak of 1000 was equivalent to an increased chance of rejection with an odds ratio of 1.47 (1.08, 2.00). Conclusion: In spite of increases or decreases in the DSA levels, there were no changes in the viral or the blood group antibodies in these patients. Thus the DSA rise is specific in contrast to the viral, blood group or third party antibodies post transplantation. Increases in the DSA post transplant in comparison to pre-treatment are strongly associated with occurrence of rejection

    Exaggerated blood pressure response to dynamic exercise despite chronic refractory hypotension : results of a human case study

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    BACKGROUND: Chronic refractory hypotension is a rare but significant mortality risk in renal failure patients. Such aberrant physiology usually deems patient unfit for renal transplant surgery. Exercise stimulates the mechano-chemoreceptors in the skeletal muscle thereby modulating the sympathetic effects on blood pressure regulation. The haemodynamic response to dynamic exercise in such patients has not been previously investigated. We present a case with severe chronic hypotension who underwent exercise testing before and after renal transplantation, with marked differences in blood pressure response to exercise. CASE PRESENTATION: A 40-year old haemodialysis-dependent patient with a 2 year history of refractory hypotension (≤80/50 mmHg) was referred for living donor renal transplantation at our tertiary centre. Each dialysis session was often less than 2 h and 30 min due to symptomatic hypotension. As part of the cardiovascular assessment, she underwent haemodynamic evaluation with cardiopulmonary exercise testing. Blood pressure normalized during unloaded pedalling but was exaggerated at maximal workload whereby it rose from 82/50 mmHg to a peak of 201/120 mmHg. Transthoracic echocardiography, tonometric measure of central vascular compliance and myocardial perfusion scan were normal. She subsequently underwent an antibody-incompatible renal transplantation and was vasopressor reliant for 14 days during the post-operative period. Eight weeks following transplant, resting blood pressure was normal and a physiological exercise-haemodynamic response was observed during a repeat cardiopulmonary exercise testing. CONCLUSION: This case highlights the potential therapeutic role of unloaded leg cycling exercise during dialysis session to correct chronic hypotension, allowing patients to have greater tolerance to fluid shift. It also adds to existing evidence that sympathetic dysfunction is reversible with renal transplant. Furthermore chronic hypotension with preserved exercise-haemodynamic response and cardiovascular reserve should not preclude these patients from renal transplant surgery

    O-GlcNAcase Fragment Discovery with Fluorescence Polarimetry

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    The attachment of the sugar N-acetyl-D-glucosamine (GlcNAc) to specific serine and threonine residues on proteins is referred to as protein O-GlcNAcylation. O-GlcNAc transferase (OGT) is the enzyme responsible for carrying out the modification, while O-GlcNAcase (OGA) reverses it. Protein O-GlcNAcylation has been implicated in a wide range of cellular processes including transcription, proteostasis, and stress response. Dysregulation of O-GlcNAc has been linked to diabetes, cancer, and neurodegenerative and cardiovascular disease. OGA has been proposed to be a drug target for the treatment of Alzheimer’s and cardiovascular disease given that increased O-GlcNAc levels appear to exert a protective effect. The search for specific, potent, and drug-like OGA inhibitors with bioavailability in the brain is therefore a field of active research, requiring orthogonal high-throughput assay platforms. Here, we describe the synthesis of a novel probe for use in a fluorescence polarization based assay for the discovery of inhibitors of OGA. We show that the probe is suitable for use with both human OGA, as well as the orthologous bacterial counterpart from <i>Clostridium perfringens</i>, <i>Cp</i>OGA, and the lysosomal hexosaminidases HexA/B. We structurally characterize <i>Cp</i>OGA in complex with a ligand identified from a fragment library screen using this assay. The versatile synthesis procedure could be adapted for making fluorescent probes for the assay of other glycoside hydrolases

    Rapid, ultra low coverage copy number profiling of cell-free DNA as a precision oncology screening strategy.

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    Current cell-free DNA (cfDNA) next generation sequencing (NGS) precision oncology workflows are typically limited to targeted and/or disease-specific applications. In advanced cancer, disease burden and cfDNA tumor content are often elevated, yielding unique precision oncology opportunities. We sought to demonstrate the utility of a pan-cancer, rapid, inexpensive, whole genome NGS of cfDNA approach (PRINCe) as a precision oncology screening strategy via ultra-low coverage (~0.01x) tumor content determination through genome-wide copy number alteration (CNA) profiling. We applied PRINCe to a retrospective cohort of 124 cfDNA samples from 100 patients with advanced cancers, including 76 men with metastatic castration-resistant prostate cancer (mCRPC), enabling cfDNA tumor content approximation and actionable focal CNA detection, while facilitating concordance analyses between cfDNA and tissue-based NGS profiles and assessment of cfDNA alteration associations with mCRPC treatment outcomes. Therapeutically relevant focal CNAs were present in 42 (34%) cfDNA samples, including 36 of 93 (39%) mCRPC patient samples harboring AR amplification. PRINCe identified pre-treatment cfDNA CNA profiles facilitating disease monitoring. Combining PRINCe with routine targeted NGS of cfDNA enabled mutation and CNA assessment with coverages tuned to cfDNA tumor content. In mCRPC, genome-wide PRINCe cfDNA and matched tissue CNA profiles showed high concordance (median Pearson correlation = 0.87), and PRINCe detectable AR amplifications predicted reduced time on therapy, independent of therapy type (Kaplan-Meier log-rank test, chi-square = 24.9, p &lt; 0.0001). Our screening approach enables robust, broadly applicable cfDNA-based precision oncology for patients with advanced cancer through scalable identification of therapeutically relevant CNAs and pre-/post-treatment genomic profiles, enabling cfDNA- or tissue-based precision oncology workflow optimization

    Comparative study of intra and post-operative complications between total abdominal hysterectomy and laparoscopic assisted vaginal hysterectomy

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    Background: Vaginal hysterectomy is preferable due to faster recovery, decreased morbidity and absence of an abdominal incision. The aim was to compare the risks and complications of laparoscopy assisted vaginal hysterectomy and total abdominal hysterectomy in terms of intra-operative and post-operative complications.Methods: A retrospective observational study was conducted in the Gynaecology ward at Vinakaya Mission’s Kirupananda Variyar Medical College and Hospitals, Salem, Tamil Nadu, India. The data for the past 1-year record was taken for analysis. A total of 80 subjects were included in the study and were divided into two groups with 40 patients under TAH (total abdominal hysterectomy) group and 40 under LAVH (Laproscopic assisted vaginal hysterectomy) group. The primary outcome of the present analysis was incidence of perioperative complications like blood loss and the secondary outcomes were operating time, blood loss, urinary tract injury, rate of conversion to laparotomy, postoperative pain, and length of postoperative stay.Results: The mean intra-operative blood loss was measured among both the groups and it was found to be very high among TAH group (201 ml) compared to LAVH group (149.8 ml) and the difference was found to be statistically significant (p <0.05). Similarly, the duration of operative procedure was found to be less in LAVH group (57.9 mins) compared to TAH group (72.6 mins) and the difference was found to be statistically significant (p <0.05). Post-operative wound infection (14 vs 0) was found to be more among the patients in TAH group than that of the LAVH group and the difference was found to be statistically significant (p <0.05).Conclusions: LAVH is a safe and effective surgical treatment for benign gynaecological diseases and should be offered whenever possible, taking into account the low rate of complications and cost-effectiveness
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