Browsing by Author "Anurag Gupta"

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Application of fuzzy clustering for selection of coating materials for MEMS sensor array
(Springer Verlag, 2018) Anurag Gupta; T. Sonamani Singh; R.D.S. Yadava
In this paper we apply fuzzy subtractive and fuzzy c-means clustering (FSC and FCM) methods for polymer data mining for making MEMS (microelectromechanical system) sensor array-based electronic nose (E-nose). A MEMS cantilever coated with a selective polymer responds to the target chemical by its preferential sorption and ensuing modification of the cantilever parameters (mass, stiffness, and surface stress). An E-nose system operates by using an array of broadly selective sensors (polymer coatings) and application of pattern recognition. The selection of polymer coatings is crucial for desired performance features of an E-nose. A minimal set of polymers from a large list of prospective polymers were selected by the FSC and FCM methods. The detection and monitoring of fish spoilage was taken to be the case study. Both the static and the dynamic mode MEMS sensing were employed for data generation and principal component analysis. A comparative analysis of polymer selection method vis-à-vis sensing mode is carried out. © Springer Nature Singapore Pte Ltd. 2018.
Cardiff repair of incisional hernia: A University hospital experience
(1998) Vijay K. Shukla; Anurag Gupta; Harbans Singh; Manoj Pandey; Amitabh Gautam
Objective: To analyse our results of the 'Cardiff' (far and near) repair in incisional hernias. Design: Prospective study. Setting: University hospital, Varanasi, India. Subjects: 50 patients who presented with incisional hernias between January 1990 and December 1994. Intervention: Interrupted far-and-near sutures inserted after excision of the sac. The contents were pushed into the abdomen and the peritoneum sutured with non- absorable polypropylene (prolene). Main Outcome Measures: Early and late morbidity. Six patients developed postoperative complications (wound infection, n = 3; flap necrosis, n = 2; and wound sinus, n = 1). No patient has been lost to follow up and there have been no signs of recurrence after a mean follow up of 52 months. Conclusion: The meticulous application of this simple surgical technique has low morbidity and is cost effective. We recommend it for small and medium size defects.
Dependence of superconductivity and its weakly linked behavior in bulk LaO 1-xF xFeAs on F doping
(2012) Anurag Gupta; Hannu Huhtinen; Chandra Shekhar; Kim Schlesier; Pankaj Srivastava; Amit Srivastava; O.N. Srivastava; Reino Laiho; A.V. Narlikar
Samples of oxypnictide compound LaO1-xFx FeAs, with x = 0.15 and 0.2 corresponding to over- and highly over-doped compositions, respectively, were prepared by solid-state reaction. We present their characterization by XRD and HRTEM, as well as resistivity ρ(T), magnetization M(B) and microwave modulated absorption (MMA) response between 4.2-300 K and applied fields B = 0-8 T. With change in x, both the superconducting and magnetic behavior of the samples shows an interesting pattern. The "magnetic anomaly" at T ∼ 130 K, observed in M(T) for x = 0, instead of getting totally suppressed shows a tendency to reappear in x = 0.2 sample. Both samples typically show ρ(300 K) > 2.8 × 10- 3 Ω;2 cm and critical current density J c(5 K, 1 T) < 2 × 10 7 A/m 2. The superconducting transitions as measured by ρ(T) at B = 0 are found broad for both x = 0.15 and 0.2 samples with transition widths ∼2.5 and 6 K, respectively. The slope |dB c2/dT|(where B c2 is upper critical field) determined by resistive onsets, for the x = 0.15 and 0.2 samples, has values ∼7.5 and 3.5 T/K, respectively. The superconducting state characteristics as reflected by ρ(T, B), M(T), magnetic J c(B) and MMA response are typical of the presence of weakly linked inter-grain regions in both the samples. Our HRTEM images of the x = 0.15 sample show the presence of high angle (∼43°) grain boundaries, which are well known to limit the J c in cuprate-based high T c bulk materials. © 2012 Springer Science+Business Media, LLC.
Detection and quantification of fish spoilage marker using polymer-coated micro-electro-mechanical systems sensor array-based electronic nose—a computational study
(Springer, 2025) Anurag Gupta; T. Sonamani Singh; A. K. Sharma; R. D.S. Yadava
This study explores the feasibility of polymer functionalized microelectromechanical systems (MEMS) sensor array-based Electronic nose for fish spoilage detection. Using vapor-polymer partition coefficients as key features, we employ data-driven techniques, including principal component analysis (PCA), fuzzy c-means (FCM), fuzzy subtractive clustering (FSC), and particle swarm optimization (PSO), to optimally select five polymers from a pool of 39 commercial candidates. The selected polymers’ effectiveness in generating diversified sensor responses is evaluated through a virtual sensor array model. The MEMS sensor array, functionalized with these polymers, operates in both static and dynamic sensing modes. By leveraging experimentally reported volatile organic compounds (VOCs) in fish headspace, we demonstrate effective separation of spoilage markers, particularly trimethylamine (TMA), dimethylamine (DMA), 1-Octanol, and Indole, in principal component space. The study further validates the system’s calibration for TMA quantification using generalized regression neural networks (GRNN) and radial basis function (RBF) neural networks, achieving an RMSE of 0.0002 and R2 = 0.999. These findings highlight the feasibility of MEMS-based E-Nose technology for real-time fish spoilage monitoring, with potential for industrial applications. © Association of Food Scientists & Technologists (India) 2025.
Double chambered right ventricle with ventricular septal defect presenting in adulthood
(2011) Nand Kumar Singh; Jyoti Prakash Lal Karn; Anurag Gupta; S. Senthil
Double-chambered right ventricle (DCRV) is a form of right ventricular outflow tract obstruction. It typically presents in childhood or adolescence. Only a handful of previous cases have been described in which DCRV occurred in adulthood. We report here a case of DCRV with ventricular septal defect (VSD) presenting in adulthood. © JAPI.
Effect of Ca doping for Y on structural/microstructural and superconducting properties of YBa2Cu3O7-δ
(Elsevier, 2005) Rajiv Giri; V.P.S. Awana; H.K. Singh; R.S. Tiwari; O.N. Srivastava; Anurag Gupta; B.V. Kumaraswamy; H. Kishan
We report systematic studies of structural, microstructural and transport properties of Y1-xCaxBa2Cu3O 7-δ bulk samples with 0.20 ≥ x ≥ 0.0. The partial substitution of Ca2+ at Y3+ site in YBa2Cu 3O7-δ leads towards slightly overdoped regime, which along with disorder in CuO2 planes is responsible for decrease in superconducting transition temperature (Tc) of the doped system. The microstructural variants being studied by transmission electron microscopy (TEM) technique in imaging and selected area diffraction modes revealed an increase in the density of twins with increase in Ca concentration despite the fact that there is slight decrease in the orthorhombicity. This is against the general conviction of decrease in twin density with decreasing orthorhombicity. An increase in twin density results in sharpening of twin boundaries with increasing Ca concentration. These sharpened twin boundaries may work as effective pinning centers. A possible correlation between microstructural features and superconducting properties has been put forward and discussed in the present investigation. © 2005 Elsevier B.V. All rights reserved.
Hospital based prospective longitudinal clinical and immunologic study of 179 patients of primary anti-phospholipid syndrome
(2013) Nand K. Singh; Dibya R. Behera; Ankit Agrawal; Mahendra Narayan Singh; Vikash Kumar; Manoj Godhra; Anurag Gupta; Devesh P. Yadav; Usha Singh; Lakshmi Kant Pandey; Manjari Matah
Aim: To study the clinical and immunological features of primary antiphospholipid syndrome (APS), and to analyze the differences between primary APS and APS associated with autoimmune rheumatic disease (ARD/APS). Methods: This prospective, longitudinal study, carried out from December 2004 to July 2011 included 179 patients with primary APS and 52 patients of ARD/APS diagnosed as per modified 2006 Sapporo's Criteria. Results: Out of 179 patients of primary APS, 12 were male and 167 were female. The mean age at the time of study entry was 27 ± 4.33 years. Venous thrombosis was noted in 33 (18.43%) patients. Seventeen patients had deep vein thrombosis and 11 (7.19%) had cortical vein and/or cortical sinus thrombosis. Arterial thrombosis was noted in 19 (10.61%) patients, out of which nine had intracranial arterial thrombosis. Thirty-two (17.85%) had recurrent early fetal losses (< 10 weeks) and 97 (54.18%) had late fetal loss (> 10 weeks). Immunoglobulin G (IgG) and IgM aCLA were present in 141 (78.77%) and 32 (17.87%) patients respectively, whereas lupus anticoagulant was present in 99 (55.3%) patients. In patients with bad obstetric outcome, lupus anticoagulant positivity was significantly more prevalent (P < 0.05) than aCLA positivity. Both venous and arterial thrombosis were significantly more common (P < 0.05) in ARD/APS. However, late fetal loss was significantly more prevalent (P < 0.001) in primary APS. Conclusion: Primary APS may lead to a variety of clinical manifestations due to venous and/or arterial thrombosis, which at times may be lethal. It is also an important cause of early and late pregnancy loss(es) and other pregnancy morbidities. © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.
Impact of Zn substitution on phase formation and superconductivity of Bi1.6Pb0.4Sr2Ca2Cu 3-xZnxO10-δ with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12
(2005) R.B. Saxena; Rajiv Giri; V.P.S. Awana; H.K. Singh; M.A. Ansari; B.V. Kumaraswamy; Anurag Gupta; Rashmi Nigam; K.P. Singh; H. Kishan; O.N. Srivastava
Samples of series Bi1.6Pb0.4Sr2Ca 2Cu3-xZnxO10-δ with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12 are synthesized by solid-state reaction route. All the samples crystallize in tetragonal structure with majority (> 90%) of Bi-2223 (Bi2Sr2Ca2Cu3O10) phase (c-lattice parameter ∼ 36 Å). The proportion of Bi-2223 phase decreases slightly with an increase in x. The lattice parameters a and c of main phase (Bi-2223) do not change significantly with increasing x. Superconducting critical transition temperature (Tc) decreases with x as evidenced by both resistivity [ρ(T)] and ac magnetic susceptibility [χ(T)] measurements. Interestingly the decrement of Tc is not monotonic and the same saturates at around 96 K for x > 0.06. In fact Tc decreases fast (∼ 10 K/at%) for x = 0.015 and 0.03 samples and later nearly saturates for higher x values. Present results of Zn doping in Bi-2223 system are compared with other Zn-doped HTSC (high temperature superconducting) systems, namely the RE-123 (REBa2Cu3O7) and La-214 ((La, Sr)2CuO4). © World Scientific Publishing Company.
MEMS sensor array-based electronic nose for breath analysis - A simulation study
(Institute of Physics Publishing, 2019) Anurag Gupta; T Sonamani Singh; R.D.S. Yadava
The paper presents a simulation study of breath analysis based on theoretical models of microelectromechanical structure (MEMS) cantilever sensor array. The purpose of this study is to suggest a methodology for the development of MEMS electronic nose (e-nose) for monitoring disease-specific volatiles in exhaled breath. Oxidative stress and diabetes are taken as case studies for the assessment of e-nose designs. The detection of ethane for general oxidative stress, isoprene for hypoxia, and acetone for diabetes are considered for targeted detection. A number of volatiles concurrently present in the exhaled breath are taken as interferents. The MEMS cantilevers are coated with volatile-selective polymers and are analyzed in both the static and dynamic modes. The sensor array is defined by polymer selections based on three data mining methods: principal component analysis (PCA), fuzzy c-means clustering (FCM), and fuzzy subtractive clustering (FSC). This utilizes vapor/polymer partition coefficients as a database. Analyses are carried out to find optimal combinations of the polymer selection method and cantilever sensing mode. Virtual breath analysis experiments are analyzed by PCA for target discrimination. It is found that no single combination works best in all conditions. The acetone (diabetes) detection is best in both sensing modes with the polymers selected by FSC; the isoprene (hypoxia) is detectable only in static sensing mode with polymers selected by FCM clustering; and the ethane (oxidative stress) detection is possible by all sensing modes and polymer selections, provided the breath samples are preconcentrated. This study suggests that it is difficult to realize a single general-purpose MEMS breath analyzer. The dedicated analyzers for specific disease indications can however be made with an optimal combination of sensing mode and polymer coatings. © 2018 IOP Publishing Ltd.
Occurrence of superconductivity and magnetism in nominally undoped LaOFeAs
(2010) Anurag Gupta; Hannu Huhtinen; Chandra Shekhar; Kim Schlesier; Pankaj Srivastava; Amit Srivastava; O.N. Srivastava; Reino Laiho; A.V. Narlikar
Superconductivity in a LaOFeAs system is known to get introduced by F-doping (LaO 1-x F x FeAs) even under ambient conditions and oxygen deficiency (LaO 1-x FeAs) under high pressure conditions. Hitherto unreported, superconductivity in F-free undoped LaOFeAs samples is observed and confirmed for the first time by various characterization tools-resistive ρ(T,B), magnetic M(T,B) and modulated microwave absorption (MMA) measurements. The ρ(T) at B=0 shows a clear superconducting transition with an onset at T con∼17 K and a tail-like behavior when R goes to zero at T c0∼8 K. In the presence of B, the superconducting transition shifts to lower T with a rate ∼-5.5 and -1.65 T/K, depending on whether the ρ(T) has dropped to 90% or 5% of its normal state value, respectively. M(T) in zero field cooling at B=10 mT shows diamagnetic downturn below at ∼12 K. At TT c0, indicating the presence of weak link superconducting networks in the sample. The sample shows a complex electrical and magnetic behavior in the normal state. For instance, ρ(T) reveals a weak SDW-like anomaly at T∼132 K along with a resistivity minimum at T min∈∼78 K. M(T) also shows the presence of a magnetic anomaly at T∼130 K. Both below and above T con, presence of an additional ferromagnetic component is observed in the isothermal M(B) loop measurements. The superconducting and normal state features of our sample are compared with other undoped and doped LaOFeAs systems reported in the literature. © 2010 Springer Science+Business Media, LLC.
Outcomes of symptomatic coronavirus disease 19 in maintenance hemodialysis patient in India
(John Wiley and Sons Inc, 2021) Narayan Prasad; Manas Ranjan Behera; Mansi Bhatt; Sanjay Kumar Agarwal; N. Gopalakrishnan; Edwin Fernando; Arpita Roy Chaudhary; Manisha Sahay; Shivendra Singh; Apoorva Jain; Shruti Tapiawala; Aniket Kamble; Umesh Khanna; Rubina Bohra; Anurag Gupta; Urmila Anandh; Vivekanand Jha
Background: Maintenance hemodialysis (MHD) patients face disadvantages with higher risk of acquiring SARS-CoV-2 infection, atypical manifestations, and associated multiple comorbidities. We describe patients' outcomes with symptomatic COVID-19 on MHD in a large cohort of patients from India. Methods: Data were collected prospectively from hemodialysis units in 11 public and private hospitals between March 15, 2020, and July 31, 2020. The survival determinants were analyzed using stepwise backward elimination cox-regression analysis. Results: Of the 263 total patients (mean age 51.76 ± 13.63 years and males 173) on MHD with symptomatic COVID-19, 35 (13.3%) died. Those who died were older (p = 0.01), had higher frequency of diabetic kidney disease (p = 0.001), comorbidities (p = 0.04), and severe COVID-19 (p = 0.001). Mortality was higher among patients on twice-weekly MHD than thrice-weekly (p = 0.001) and dialysis through central venous catheter (CVC) as compared to arteriovenous fistula (p = 0.001). On multivariate analysis, CVC use (HR 2.53, 95% CI 1.26–5.07, p = 0.009), disease severity (HR = 3.54, 95% CI 1.52–8.26, p = 0.003), and noninvasive ventilatory support (HR 0.59, 95% CI 0.25–0.99, p = 0.049) had significant effect on mortality. Conclusion: The adjusted mortality risk of COVID-19 in MHD patients is high in patients associated with severe COVID-19 and patients having CVC as vascular access. © 2021 Wiley Periodicals LLC.
Oxidative stress detection by MEMS cantilever sensor array based electronic nose
(American Institute of Physics Inc., 2018) Anurag Gupta; T. Sonamani Singh; Priyanka Singh; R.D.S. Yadava
This paper is concerned with analyzing the role of polymer swelling induced surface stress in MEMS chemical sensors. The objective is to determine the impact of surface stress on the chemical discrimination ability of MEMS resonator sensors. We considered a case study of hypoxia detection by MEMS sensor array and performed several types of simulation experiments for detection of oxidative stress volatile organic markers in human breath. Both types of sensor response models that account for the surface stress effect and that did not were considered for the analyses in comparison. It is found that the surface stress (hence the polymer swelling) provides better chemical discrimination ability to polymer coated MEMS sensors. © 2018 Author(s).
Polymer-coated MEMS chemical sensor array for monitoring oxidative stress by breath analysis
(Institute of Electrical and Electronics Engineers Inc., 2017) Anurag Gupta; T. Sonamani Singh; R.D.S. Yadava
The paper presents a simulation study on polymer-coated MEMS (microelectromechanical system) sensor array for monitoring VOCs (volatile organic compounds) emissions in breath that are linked to oxidative stress in human body. The sensing polymers were selected on the basis of thermodynamic partition coefficient data analyzed by principal component analysis (PCA) and fuzzy c-means (FCM) clustering. The polymer functionalized sensor array provides transduction platform for MEMS electronic nose (E-nose). The E-nose responses patterns were synthesized for both the static and the dynamic modes of transduction for realistic analyte concentrations over ppm to ppb range and noise level. These were analyzed for discrimination of oxidative stress VOC markers in breath by monitoring separability in principal component space. The study suggests application of MEMS based electronic nose system for monitoring disease biomarkers in breath for clinical diagnostics. © 2017 IEEE.
Role of anti-annexin A5 in pathogenesis of hypercoagulable state in patients with antiphospholipid syndrome.
(2013) Nand K Singh; Dawesh Prakash Yadav; Anurag Gupta; Usha Singh; Manoj Godara
Despite several attempts made during the last decade, the exact pathogenesis of exceedingly high thrombotic events and bad obstetric outcome in antiphospholipid syndrome (APS) remains elusive. Anti-annexin A5 (aANX IgG) is thought to have a role in pathophysiology of APS. We studied role of aANX IgG in the pathogenesis of hypercoagulable state in APS patients. We estimated levels of aANX IgG in 112 patients with APS (86 primary and 26 secondary). We also estimated aANX IgG levels in 40 age- and sex-matched healthy controls, 10 patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) each, without any history of thrombosis or pregnancy morbidity, 10 patients of non-APS thrombosis and 10 patients of pregnancy loss without APS. Only three healthy controls, two SLE (P = 0.239), one RA patient (P = 0.794), three non-APS thrombosis patients (P = 0.086) and two patients with pregnancy loss without APS (P = 0.258) had marginally elevated values, whereas 53 primary APS (P < 0.001) and 16 secondary APS (P < 0.001) were positive. We also compared aANX IgG levels in different groups. Mean ± standard errors of the mean of healthy controls was 3.77 ± 0.49, in SLE patients it was 4.88 ± 1.17 (P = 1.000), in RA patients it was 4.67 ± 0.97 (P = 1.000), in non-APS thrombosis it was 7.93 ± 0.88 (P = 0.488) and in pregnancy loss without APS it was 6.80 ± 0.93 (P = 0.789). However, it was significantly elevated in primary APS (12.87 ± 1.07, P < 0.001), secondary APS (11.98 ± 1.41, P = 0.001) and total APS patients (12.68 ± 0.88, P < 0.001). From the above observations it appears that aANX IgG plays a significant role in producing a hypercoagulable state in primary and secondary APS. © 2013 The Authors International Journal of Rheumatic Diseases © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.
Sturge-Weber syndrome
(2013) Anurag Gupta; Devesh Yadav; Nand Kumar Singh
[No abstract available]
Ultrasound-guided fine needle aspiration cytology of malignant gallbladder masses
(1997) Vijay K. Shukla; Manoj Pandey; Mohan Kumar; Bimal P. Sood; Anurag Gupta; Nakul C. Aryya; Ram C. Shukla; Dhirendra N. Verma
OBJECTIVE: To determine the accuracy and reliability of ultrasound (US)�guided fine needle aspiration cytology (FNAC) over blind aspiration in gallbladder masses. STUDY DESIGN: We performed FNAC in 107 cases of carcinoma of the gallbladder; blind aspiration was done in 71 patients (66.36%) and US-guided aspiration in 36 (33.64%). In cases where FNAC after the first aspiration showed the aspirate to be inflammatory, acellular (inconclusive) or suspicious for malignancy, FNAC was repeated under US guidance. Diagnosis was later confirmed by histopathology in all cases. RESULTS: After the first aspiration, gallbladder malignancy was confirmed in 77 (71.96%) cases. Of these 77 cases, 34 underwent US-guided aspiration, and the remaining 43 underwent blind aspiration. Cases with inflammatory or acellular (inconclusive) aspirates or that were suspicious for malignancy after the first aspiration underwent a second aspiration under ultrasonic guidance. On the second aspiration of 30 cases, 16 (53.33%) proved to be of adenocarcinoma, 7 (23.33%) were suspicious for malignancy, 5 (16.66%) were inflammatory, and 2 (6.66%) were acellular. Diagnosis was later confirmed by histopathology in all cases. US-guided FNAC had diagnostic accuracy of 95% as compared to 60% on blind aspiration. There was no major complication or needle tract recurrence of the disease. CONCLUSION: US-guided FNAC is safe, rapid, reliable, cost-effective and accurate in diagnosing gallbladder carcinoma. © 1997 The International Academy of Cytology Acta Cytologica.
Unexplored photoluminescence from bulk and mechanically exfoliated few layers of Bi2Te3
(Nature Publishing Group, 2018) Bipin Kumar Gupta; Rabia Sultana; Satbir Singh; Vijeta Singh; Geet Awana; Anurag Gupta; Bahadur Singh; A.K. Srivastava; O.N. Srivastava; S. Auluck; V.P.S. Awana
We report the exotic photoluminescence (PL) behaviour of 3D topological insulator Bi2Te3 single crystals grown by customized self-flux method and mechanically exfoliated few layers (18 ± 2 nm)/thin flakes obtained by standard scotch tape method from as grown Bi2Te3 crystals. The experimental PL studies on bulk single crystal and mechanically exfoliated few layers of Bi2Te3 evidenced a broad red emission in the visible region from 600-690 nm upon 375 nm excitation wavelength corresponding to optical band gap of 2 eV. These findings are in good agreement with our theoretical results obtained using the ab initio density functional theory framework. Interestingly, the observed optical band gap is several times larger than the known electronic band gap of ∼0.15 eV. The experimentally observed 2 eV optical band gap in the visible region for bulk as well as for mechanically exfoliated few layers Bi2Te3 single crystals clearly rules out the quantum confinement effects in the investigated samples which are well known in the 2D systems like MoS2,WS2, WSe2, and MoSe2 for 1-3 layers. © 2018 The Author(s).
Xanthogranulomatous cholecystitis
(1998) Vinod K. Dixit; Anand Prakash; Anurag Gupta; M. Pandey; A. Gautam; Mohan Kumar; Vijay K. Shukla
Xanthogranulomatous cholecystitis exists in a small but significant proportion of routine cholecystectomy specimens. A few recent reports have shown a possible association of this disease with carcinoma of the gallbladder. All cholecystectomized specimens were prospectively evaluated over a period of two and half years in a single surgical unit to examine the incidence of xanthogranulomatous cholecystitis and its association, if any, with carcinoma of the gallbladder in an area that is prone to gallbladder diseases. A total of 460 cholecystectomies were performed for various gallbladder diseases. Histological confirmation revealed chronic cholecystitis in 311 (67.6%) cases, carcinoma of the gallbladder in 62 (13.5%), acute cholecystitis in 29 (6.3%), xanthogranulomatous cholecystitis in 41 (8.9%), and xanthogranuloma and carcinoma of the gallbladder in one case (0.2%) only. Almost all cases were suspected to have chronic cholecystitis on clinical and ultrasonographic features. Two specimens on gross examination showed mass lesions, and hence were suspected to be carcinoma of the gallbladder. Subsequent frozen section and histopathology demonstrated xanthogranulomatous cholecystitis. Only one case of xanthogranuloma was found to be associated with carcinoma of the gallbladder but no firm association could be established between xanthogranulomatous cholecystitis and carcinoma of the gallbladder.