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Now showing items 1 - 10 of 10


    Upadhyay, Gaurav   Tripathi, Vijay Shanker  

    In this article, a switchable coplanar linearly polarized multiband microstrip patch antenna is proposed and analyzed. This antenna can be used in many modern wireless communication systems like ITS, WLAN, WiMAX, Direct broadcast satellite etc. The antenna is loaded with two PIN-diodes. Proposed antenna has two patches that are excited by two microstrip feeds to operate in frequency 3 to 20 GHz bands. The induced current can be changed by switching the diodes, resulting in different operating frequency bands. The measured and simulated results are in good comparison with each other. The impedance bandwidth of proposed antenna is up to 25% and a peak gain of 8 dB. (C) 2017 Wiley Periodicals, Inc.
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  • Pin-diode based switchable multiband dual feed microstrip patch antenna

    Upadhyay, Gaurav   Tripathi, Vijay Shanker  

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  • Recent Trends in Transdermal Drug Delivery System - A Review

    Upadhyay, Gaurav   Verma, Shubham  

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    Upadhyay, Jyoti   Upadhyay, Gaurav   Rana, Amita Joshi  

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  • Impact of high-grade atrioventricular block and cumulative frequent pacing on atrial arrhythmias

    Wali, Eisha   Deshmukh, Amrish   Bukari, Abdallah   Broman, Michael   Aziz, Zaid   Beaser, Andrew   Upadhyay, Gaurav   Nayak, Hemal M.   Tung, Roderick   Ozcan, Cevher  

    BackgroundThe relationship between high-grade atrioventricular block (HGAVB) with cumulative frequent pacing and risk of atrial arrhythmias (AAs) has not been well characterized. We hypothesized HGAVB and pacing may have significant impact on incidence and prevalence of AAs by modulating atrial substrate. ObjectiveTo determine impact of HGAVB and pacing on AAs including atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT). MethodsAll consecutive patients who underwent dual-chamber pacemaker implantation for HGAVB from 2005 to 2011 at the University of Chicago were included. AAs and percent of pacing were detected through device interrogation. Patients' data were collected from electronic medical records and clinic visits. ResultsA total of 166 patients (mean age 7115years; 54% female, 56% African American) were studied. AF was documented in 27% of patients before pacemaker implantation. During a mean 5.8 +/- 2.2years of follow-up, 47% had device-detected AF, 10% AFL, and 26% AT. New-onset AF was documented in 40 of the 122 patients without prior AF (33%). Continuous ( 99%) right ventricular pacing was associated with significantly decreased AF prevalence (34%vs 59%, P=3D0.005), and correlated with lower incidence (26%vs 41%, P=3D0.22). Pacing suppressed AF in 14% of patients with baseline AF; those patients had lower atrial pacing (3.2%vs 45%, P<0.0001). Left atrial dilation was the only independent predictor of AF with frequent pacing (P=3D0.009). ConclusionsHGAVB is associated with high incidence and prevalence of AAs with and without pacing. Cumulative frequent (99%) ventricular pacing reduces risk of AF in patients with HGAVB.
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  • Prevalence and predictors of atrial arrhythmias in patients with sinus node dysfunction and atrial pacing

    Bukari, Abdallah   Wali, Eisha   Deshmukh, Amrish   Aziz, Zaid   Broman, Michael   Beaser, Andrew   Upadhyay, Gaurav   Nayak, Hemal   Tung, Roderick   Ozcan, Cevher  

    PurposeThis study aimed to determine the incidence, prevalence, and predictors of atrial arrhythmias (AAs) in patients with symptomatic sinus node dysfunction (SND) who required permanent pacemaker implantation. Also, we evaluated the impact of atrial pacing (AP) on AAs.MethodsAll consecutive patients who underwent pacemaker implantation from 2005 to 2011 were included. Atrial fibrillation (AF), atrial flutter (AFL), atrial tachycardia (AT), and AV nodal reentrant tachycardia (AVNRT) were detected via pacemaker interrogation and clinical documentation.ResultsThe study group included 322 patients (44% male) with mean age 68.815years and followed for an average of 5.6 +/- 2.2years (median 5.7years). Overall, 61.8% were found to have any AA at follow-up. Individual prevalence of AAs was high as follows: AF 43.5%, AFL 6.5%, AT 25%, and AVNRT 6.8%. AF was documented in 23% of patients (n=3D74) prior to pacemaker; among those, 15% (n=3D11) had no recurrence of AF with average AP of 74%. The incidence of new-onset AF after pacemaker was 15.8%. In subgroup analysis, prevalence of AF was increased by 16% with high rate of AP (81-100%) and 17% with lower rate of AP (0-20%). Incidence of new-onset AF was not affected by AP. Diabetes, hypertension, and left atrial enlargement were predictors of AAs. White men and women had higher prevalence of AF.ConclusionsAAs are highly prevalent in SND, particularly in white patients. Paroxysmal AF is suppressed with AP in minority, but there is no impact of AP on new-onset AF. Patients with diabetes, hypertension, and dilated atria must be monitored closely for early detection of AAs.
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  • An international, multicenter, prospective, observational study of the side-to-side isoperistaltic strictureplasty in Crohn's disease.

    Michelassi, Fabrizio   Taschieri, Angelo   Tonelli, Francesco   Sasaki, Iwao   Poggioli, Gilberto   Fazio, Victor   Upadhyay, Gaurav   Hurst, Roger   Sampietro, Gianluca M   Fazi, Marilena   Funayama, Yuji   Pierangeli, Filippo  

    PURPOSE: The side-to-side strictureplasty is a bowel-sparing alternative to resection in the treatment of stricturing Crohn's disease. This study was initiated to review the adoption of the side-to-side strictureplasty as a new surgical technique and the relative outcomes a decade after its description.METHODS: A total of 184 unique patients from six centers in the United States, Italy, and Japan served as the basis for this study. A questionnaire instrument was used to assemble prospectively acquired preoperative, intraoperative, perioperative, and postoperative data from each center into a computer-generated database.RESULTS: Average age at surgery for patients selected for a side-to-side strictureplasty varied significantly between centers (minimum, 31.0 years; maximum, 39.5 years, P < 0.006). Use of the side-to-side strictureplasty technique for primary Crohn's disease vs. surgically recurrent disease also varied significantly by center (primary minimum, 16.7 percent; maximum, 68.6 percent, P < 0.03). Furthermore, length of diseased bowel selected for construction of a side-to-side strictureplasty was significantly different among centers (minimum, 20.8 +/- 9.9 cm; maximum, 64.3 +/- 29.3 cm, P < 0.001). Use of synchronous bowel resection away from the site of the side-to-side strictureplasty was relatively common (minimum, 21.1 percent; maximum, 66.7 percent) as it was with the use of additional synchronous strictureplasties (minimum, 41.9 percent; maximum, 83.3 percent). The six centers experienced a low number of complications (minimum, 5.7 percent; maximum, 20.8 percent). Forty-one of 184 total patients required surgery for recurrent disease, with an average time to recurrence of 35 months. The difference of reoperation-free five-year survival experienced by the patients in the six centers was not statistically significant, with a cumulative reoperation-free five-year survival of 77 percent across all centers.CONCLUSIONS: Worldwide implementation of the side-to-side strictureplasty technique and its variations has occurred. This procedure carries a very low mortality and morbidity rate, with acceptable recurrence rates.
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  • Meta-analysis of biventricular vs. right ventricular pacing mode in patients with atrial fibrillation undergoing atrioventricular nodal ablation: what was the quality of the included trials? - reply.

    Chatterjee, Neal   Upadhyay, Gaurav   Singh, Jagmeet  

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  • [IEEE 2016 IEEE International Conference on Recent Trends in Electronics, Information & Communication Technology (RTEICT) - Bangalore, India (2016.5.20-2016.5.21)] 2016 IEEE International Conference on Recent Trends in Electronics, Information & Communication Technology (RTEICT) - One time pad generation using quantum superposition states

    Upadhyay, Gaurav   Nene, Manisha J  

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  • [IEEE 2016 IEEE 1st International Conference on Power Electronics, Intelligent Control and Energy Systems (ICPEICES) - Delhi, India (2016.7.4-2016.7.6)] 2016 IEEE 1st International Conference on Power Electronics, Intelligent Control and Energy Systems (ICPEICES) - FEM based no-load loss calculation of triangular wound core transformer

    Upadhyay, Gaurav   Singh, Amita   Seth, Santanu Kumar   Jarial, R.K.  

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