Master of Science

thesisThe design, working principle, fabrication, and characterization of ultrasensitive ferromagnetic and magnetoelectric magnetometer are discussed in this thesis. Different manufacturing techniques and materials were used for the fabrication of the two versions of the magnetometer. The ferromagnetic microelectromechanical systems (MEMS) magnetometer was fabricated using low-pressure chemical vapor deposition (LPCVD) of silicon nitride, yielding low compressive stress, followed by patterning. The built-in stress was found to be -14 Mpa using Tencor P-10 profilometer. A neodymium magnet (NdFeB) was used as a foot-mass to increase the sensitivity of the device. A coil (Ø=3 cm), placed at a distance from the sensor (2.5-15 cm), was used to produce the magnetic field. The response of the ferromagnetic MEMS magnetometer to the AC magnetic field was measured using Laser-Doppler vibrometer. The ferromagnetic sensor's average temperature sensitivity around room temperature was 11.9 pV/pT/-C, which was negligible. The resolution of the ferromagnetic sensor was found to be 27 pT (1 pT = 10-12 T). To further improve the sensitivity and eliminate the use of the optical detection method, we fabricated a Lead Zirconate titanate (PZT) based magnetoelectric sensor. The sensor structure consisted of a 9 mm long, and 0.17 mm thick PZT beam of varying widths. A neodymium permanent magnet was used as a foot-mass in this case as well. The magnetic field from the coil generated a driving force on the permanent magnet. The driving force displaced the free end of the PZT beam and generated a proportional voltage in the PZT layer. The magnetoelectric coupling, i.e., the coupling between mechanical and magnetic field, yielded a sensor resolution of ~40 fT (1 fT = 10-15 T); an improvement by three orders of magnitude. We used high permeability Mu sheets (0.003"") attached to copper plates (0.125"") to shield stray magnetic fields around the sensor. For both the ferromagnetic MEMS and the magnetoelectric magnetometer, the initial output was improved by using external bias and parametric amplification. By applying an external DC magnetic field bias to the sensor, the effective spring compliance of the sensor was modified. Electronic feedback reduced the active noise limiting the sensor's sensitivity. We used magnetic coupling to enhance the sensors' sensitivity and to reduce the electronic noise. Two identical sensors, with identical foot-mass (permanent magnet), was used to show coupling. The magnet on one of the sensors was mounted in NS polarity, whereas, on the other it was in SN polarity. When excited by the same external AC magnetic field (using coil), one of the sensors was pulled towards the coil and the other was pushed away from it. Adding the individual sensor output, using a preamplifier, an overall increase in sensors' output was observed. The techniques mentioned above helped to improve the output from the sensor. The sensitivity of the sensor can be improved further by using a 3-axis magnetic field cancellation system, by eliminating the AC and DC stray magnetic field, by using coupled-mode resonators and by increasing the surface field intensity of the foot-mass. The magnetometers, thus, developed can be used for mapping the magnetic print of the brain

Level of patient satisfaction with online psychiatric outdoor services

BACKGROUND: The COVID-19 global pandemic exposed gaps in the treatment of common physical and mental disorders that had to do with things like lockdowns, poor convenience, fear of contracting COVID, and economic constraints. Hence, to address these treatment gaps while also limiting exposure to the COVID-19 infection, telemedicine in the form of telephone and internet consultations has increasingly become the recourse around the world. Our center adopted this trend and also launched a telepsychiatry initiative in order to better cater to the needs of patients with pre-existing mental health disorders and to ensure regular follow-ups and compliance with prescription regiments. AIM: The present study aimed to assess the level of patient satisfaction with the online psychiatric services/telepsychiatry. METHODS: The sample consisted of 100 patients with pre-existing mental health disorders. This was a cross-sectional study lasting 6 months. The DigiDoc app by Hospital Information Software (HIS) software, which is used to manage a patients appointment schedule, relevant clinical and lab details, along with follow-up prescriptions, was used to follow the selected patients for the purpose of this study. This software also provides a digital platform for video calls for online consultation. The Client Satisfaction Questionnaires-8 (CSQ-8) was employed to collect patient data for analysis. RESULTS: The mean total CSQ-8 score of the study sample was 21.015.80 (832), which corresponds to a low-to-moderate level of satisfaction with online psychiatric services/telepsychiatry. Most patients (45%) reported low satisfaction levels, followed by 37% who reported moderate levels of satisfaction. Only 18% of patients reported higher satisfaction with telepsychiatry. CONCLUSION: Despite the psychiatrists ability to provide adequate professional advice and psychoeducation through online psychiatric services, patients level of satisfaction proved moderate-to-low. This suggests a need to design standard protocols and guidelines in the search and provision of consultation services on online psychiatric service platforms that could help enhance patients levels of satisfaction

Assessing the Factors Impacting Transport Usage of Mobility App Users in the National Capital Territory of Delhi, India

Smartphone-based mobility apps have created a smartphone-enabled ecosystem of mobility services in developed countries and are slowly picking up pace in the Global South. Against this backdrop, this study used Latent Class Cluster Analysis to empirically investigate the impacts of mobility apps on transport usage patterns in Delhi by classifying users into three latent clusters based on socioeconomic characteristics, smartphone app usage, attitudes, and transport usage. Cluster 1 consisted of users with low app usage, and higher usage of public transport and intermediate public transport; Cluster 2 consisted of multimodal users with high app usage; and Cluster 3 consisted of users with moderate app usage and heavy reliance on private vehicles. Furthermore, the detailed characteristics of each latent class and factors affecting the individual’s probability of being classified into these clusters are discussed. It was found that younger users with higher education, more smartphone experience, medium-to-high household income and lower vehicle ownership had a very high probability of being classified as a multimodal traveler. Furthermore, the attitudes and preferences of users belonging to these clusters towards their choice of transport are discussed, along with a brief policy discussion for encouraging new app-based mobility services such as MaaS

Giant Synovial Cyst of Thigh: A Rare Entity

Synovial cyst occurs secondary to traumatic, degenerative, or inflammatory conditions. Synovial cysts represent abnormal distension of bursae, which communicate with the joint. Giant synovial cysts are typically due to rheumatoid arthritis, other causes being trauma and synovial pseudoarthrosis. A 33-year-old male presented to an outpatient clinic with a massive swelling on his posterolateral aspect of right thigh extending from upper one-third to the knee joint which had been increasing in size over the past six months. This was associated with dull aching pain. All laboratory investigations were within normal parameters. Even FNAC was inconclusive. With time, swelling was increasing in size. Ultrasound revealed the cystic nature of swelling. MRI showed large cystic lesion 24 × 10 × 12 cm in posterolateral aspect of thigh extending up to knee joint. Following the MRI, an excision was planned. After excision, histological examination confirmed the synovial nature of the cyst, which had a collagenous wall and dense chronic inflammatory cells. As the disease is extremely rare and asymptomatic, precise diagnosis is difficult and often delayed. We consider that open surgical excision should be reserved for cases of large synovial cysts because it can provide a complete resection of the lesion and minimize the risk of recurrence

Influence of Farmer demographics and Supply Chain Issues on Organized Retailer Performance

Advances in information technology and increased social networking have increased health awareness among people in this era. The increased health awareness has prompted people to eat healthy and stay fit. In this regard, the food sector has seen tremendous demand in terms of good quality vegetables/fruits, cereals, with hygiene, nutrition, proteins etc. With the consumer willing to pay an extra premium for the quality expected, it has been observed that the producers are still offered low prices for a good quality produce whereas the intermediaries grab a huge share of the price paid by the consumer. This research tried to understand the supply chain with the farmers in focus and explored the influence of farmer demographics and the supply chain issues on the performance of the organized retail. Linear regression analysis was used to test the linear relationship of supply chain issues with organized retailer performance. The outcome of the study implies that independent variables like demographic characteristics and supply chain issues had no control over the retailer’s performance

Influence of Farmer demographics and Supply Chain Issues on Organized Retailer Performance

Advances in information technology and increased social networking have increased health awareness among people in this era. The increased health awareness has prompted people to eat healthy and stay fit. In this regard, the food sector has seen tremendous demand in terms of good quality vegetables/fruits, cereals, with hygiene, nutrition, proteins etc. With the consumer willing to pay an extra premium for the quality expected, it has been observed that the producers are still offered low prices for a good quality produce whereas the intermediaries grab a huge share of the price paid by the consumer. This research tried to understand the supply chain with the farmers in focus and explored the influence of farmer demographics and the supply chain issues on the performance of the organized retail. Linear regression analysis was used to test the linear relationship of supply chain issues with organized retailer performance. The outcome of the study implies that independent variables like demographic characteristics and supply chain issues had no control over the retailer’s performance

Vacuum Assisted Closure Therapy versus Standard Wound Therapy for Open Musculoskeletal Injuries

Background. This study was performed to evaluate the results of vacuum assisted wound therapy in patients with open musculoskeletal injuries. Study Design and Setting. Prospective, randomized, and interventional at tertiary care hospital, from 2011 to 2012. Materials and Methods. 30 patients of open musculoskeletal injuries underwent randomized trial of vacuum assisted closure therapy versus standard wound therapy around the upper limb and lower limb. Mean patient age was years (range, 18 to 76 years). Necrotic tissues were debrided before applying VAC therapy. Dressings were changed every 3 or 4 days. For standard wound therapy, debridement followed by daily dressings was done. Data Management and Statistical Analysis. The results obtained were subjected to statistical analysis. Results. The size of soft tissue defects reduced more than 5 mm to 25 mm after VAC (mean decrease of 26.66%), whereas in standard wound therapy, reduction in wound size was less than 5 mm. A free flap was needed to cover exposed bone and tendon in one case in standard wound therapy group. No major complication occurred that was directly attributable to treatment. Conclusion. Vacuum assisted wound therapy was found to facilitate the rapid formation of healthy granulation tissue on open wounds in the upper limb and lower limb, thus to shorten healing time and minimize secondary soft tissue defect coverage procedures

SOCS3 expression induced by PIM2 requires PKC and PI3K signaling

Initiation of proinflammatory host immunity in response to infection represents as a key event in effective control and containment of the pathogen at the site of infection as well as in elicitation of robust immune memory responses. In the current investigation, we demonstrate that an integral cell wall antigen of the mycobacterial envelope, Phosphatidyl-myo-inositol dimannosides (PIM2) triggers Suppressor of cytokine signaling (SOCS) 3 expression in macrophages in a Toll-like receptor 2 (TLR2)-MyD88 dependent manner. Data derived from signaling perturbations suggest the involvement of phosphoinositide-3 kinase (PI3K) and protein kinase C (PKC) signaling pathways during PIM2 induced SOCS3 expression. Further, pharmacological inhibition of ERK1/2, but not of p38 MAP kinase or JNK abrogated the induced expression of SOCS3. The PIM2 induced activation of ERK1/2 was dependent on the activation of PI3K or PKC signaling which in turn regulated p65 nuclear factor -κB (NF-κB) nuclear translocation. Overall, current study delineates the role for PI3K-PKC axis and ERK1/2 signaling as key signaling events during PIM2 induced SOCS3 expression in macrophages

SOCS3 expression induced by PIM2 requires PKC and PI3K signaling

Initiation of proinflammatory host immunity in response to infection represents as a key event in effective control and containment of the pathogen at the site of infection as well as in elicitation of robust immune memory responses. In the current investigation, we demonstrate that an integral cell wall antigen of the mycobacterial envelope, Phosphatidyl-myo-inositol dimannosides (PIM2) triggers Suppressor of cytokine signaling (SOCS) 3 expression in macrophages in a Toll-like receptor 2 (TLR2)-MyD88 dependent manner. Data derived from signaling perturbations suggest the involvement of phosphoinositide-3 kinase (PI3K) and protein kinase C (PKC) signaling pathways during PIM2 induced SOCS3 expression. Further, pharmacological inhibition of ERK1/2, but not of p38 MAP kinase or JNK abrogated the induced expression of SOCS3. The PIM2 induced activation of ERK1/2 was dependent on the activation of PI3K or PKC signaling which in turn regulated p65 nuclear factor -kappa B (NF-kappa B) nuclear translocation. Overall, current study delineates the role for PI3K-PKC axis and ERK1/2 signaling as key signaling events during PIM2 induced SOCS3 expression in macrophages

Src Homology 3-interacting Domain of Rv1917c of Mycobacterium tuberculosis Induces Selective Maturation of Human Dendritic Cells by Regulating PI3K-MAPK-NF-κB Signaling and Drives Th2 Immune Responses*

Mycobacterium tuberculosis, an etiological agent of pulmonary tuberculosis, causes significant morbidity and mortality worldwide. Pathogenic mycobacteria survive in the host by subverting host innate immunity. Dendritic cells (DCs) are professional antigen-presenting cells that are vital for eliciting immune responses to infectious agents, including pathogenic mycobacteria. DCs orchestrate distinct Th responses based on the signals they receive. In this perspective, deciphering the interactions of the proline-glutamic acid/proline-proline-glutamic acid (PE/PPE) family of proteins of M. tuberculosis with DCs assumes significant pathophysiological attributes. In this study, we demonstrate that Rv1917c (PPE34), a representative member of the proline-proline-glutamic-major polymorphic tandem repeat family, interacts with TLR2 and triggers functional maturation of human DCs. Signaling perturbations implicated a critical role for integrated cross-talk among PI3K-MAPK and NF-κB signaling cascades in Rv1917c-induced maturation of DCs. However, this maturation of DCs was associated with a secretion of high amounts of anti-inflammatory cytokine IL-10, whereas Th1-polarizing cytokine IL-12 was not induced. Consistent with these results, Rv1917c-matured DCs favored secretion of IL-4, IL-5, and IL-10 from CD4+ T cells and contributed to Th2-skewed cytokine balance ex vivo in healthy individuals and in patients with pulmonary tuberculosis. Interestingly, the Rv1917c-skewed Th2 immune response involved induced expression of cyclooxygenase-2 (COX-2) in DCs. Taken together, these results indicate that Rv1917c facilitates a shift in the ensuing immunity toward the Th2 phenotype and could aid in immune evasion by mycobacteria