Modeling for effective computer support to MEMS product development

Microelectromechanical systems (MEMS) are miniaturized devices with high functionality. In recent years, MEMS products have become increasingly dominant in every aspect of the commercial market place. As the MEMS technology is in its infant stage and has several unique features compared to macro-scale products, it is faced with several challenges. One of them is that design and fabrication knowledge is very intrigue and thus very difficult to be accessible. An effective computer support to the MEMS product development is thus very important. This thesis study undertakes a thorough investigation into the MEMS product development process and its computer support. Specifically, the study examines the state-of-the-art in computer aided design systems in light of the support of product functionality. It is shown that MEMS product development involves high degree of uncertainty, which calls for an unconventional computer support. At this point, this study proposes an approach to construct a knowledge base in a fairly flexible and real-time manner. This approach is based on the extended function-behavior-structure framework and the template technique proposed in this thesis. The other finding is that the MEMS product development resembles the one-of-a-kind product (OKP) development. Therefore software tools for the OKP product development process can be applied to the MEMS product development process. These tools are examined, and further extensions upon them are proposed. Throughout the thesis, a microdispensing system is used as an example for illustration of concepts described in this thesis

Characterization of Carbon Nanotube Based Thin Film Field Emitter

In recent years, carbon nanotubes (CNTs) have emerged as one of the best field emitters for a variety of technological applications. The field emitting cathodes have several advantages over the conventional thermionic cathodes: (i) current density from field emission would be orders of magnitude greater than in the thermionic case, (ii) a cold cathode would minimize the need for cooling, and (iii) a field emitting cathode can be miniaturized. In spite of good performance of such cathodes, the procedure to estimate the device current is not straight forward and the required insight towards design optimization is not well understood. In addition, the current in CNT-based thin film devices shows fluctuation. Such fluctuation in field emission current is not desirable for many biomedical applications such as x-ray devices. The CNTs in a thin film undergo complex dynamics during field emission, which includes processes such as (i) evolution, (ii) electromechanical interaction, (iii) thermoelectric heating, (iv) ballistic transport, and (v) electron gas flow. These processes are coupled and nonlinear. Therefore, they must be analyzed accurately from the stability and long-term performance point of view. In this research, we develop detailed physics-based models of CNTs considering the aspects mentioned above. The models are integrated in a systematic manner to calculate the device current by using the Fowler-Nordheim equation. Using the models, we were able to capture the fluctuations in the field emission current, which have been observed in actual experiments. A detailed analysis of the results reveals the deflected shapes of the CNTs in an ensemble and the extent to which the initial state of geometry and orientation angles affect the device current. In addtion, investigations on the influence of defects and impurities in CNTs on their field emission properties have been carried out. By inclusion of defects and impurities, the field emission properties of CNTs can be tailored for specific device applications in future. For stable performance of CNT-based field emission devices, such as x-ray generators, design optimization studies have been presented. It has been found that the proposed design minimizes transience in field emission current. In this thesis, it has been demonstrated that phonon-assisted control of field emission current in CNT based thin film is possible. Finally, experimental studies pertaining to crosstalk phenomenon in a multi-pixel CNT array are presented

REASSESSING THE ROLE OF HOMOCYSTEINE AND HOLOTRANSCOBALAMIN LEVELS IN DIAGNOSING VITAMIN B12 DEFICIENCY ANEMIA

Background: Vitamin B12 deficiency can lead to irreversible neurological damage, megaloblastic anemia, osteoporosis, cerebrovascular, and cardiovascular diseases, and thus, early diagnosis is essential. Objective: The objective of the study was to assess homocysteine (Hcy) and holotranscobalamine (HoloTC) levels among patients with Vitamin B12 deficiency and to see if Hcy and HoloTC level assay can help us in diagnosis of Vitamin B12 deficiency. Methods: We carried out a cross-sectional observational study on 60 patients of Sr. B12 deficient male and female patients between the ages of 18 and 65 years in IPD and OPD patients at multispecialty hospital. Data were collected from predefined pro forma and were asked about their diet, socioeconomic status, and history. Then, these patients further undergone anthropometric measurements and investigated for Hcy and HoloTC level. The statistical analysis was done using Statistical Package for the Social Sciences (SSPS) software (version 11). Results: About 60% of cases were vegetarian and 40% of cases were non-vegetarian. Mean age of study participants was 43.67 years, mean of mean cellular volume was 90.7 fl, mean of B12 was 138 pmol/L, mean of HoloTC was 60.84 pmol/L, and mean of Hcy was 34.17 umol/L. Out of 60 patients, 10 patients had anemia, 21 patients had neurological manifestation, and 29 patients had gastrointestinal (GI) manifestation. In male group, out of 32, 11 patients had HoloTC <8.9, 19 patients had value between 8.9 and 128, and two patients had HoloTC more than 128. In female group, out of 28, seven patients had HoloTC <8.9, 14 patients had value between 8.9 and 128, and seven patients had HoloTC >128. In group of 32 male patients, none of male patients showed Hcy value <5.9, four patients showed Hcy between 5.9 and 16, and 28 patients showed Hcy value >16. Out of 28 female patients, none of female patients showed Hcy <3.36, nine patients showed Hcy between 3.36 and 20.4, and 19 patients showed Hcy >20.4. p <0.001 is highly statistically significant. Conclusion: In our study, we found that 31.33% of cases also showed decreased HoloTC along with B12 deficiency, but this correlation was statistically insignificant. We also found that 78.33% of cases showed increased Hcy along with serum B12 deficiency, which was statistically significant, so we concluded that there is a strong association between serum B12 and Hcy. We found that all patients with elevated Hcy also had low HoloTC except in two cases, but this correlation was not found to be statistically significant

A NOVEL APPROACH TOWARDS DEVELOPMENT OF QUINAZOLINE DERIVATIVES IN PAIN MANAGEMENT

ABSTRACT-   Objective: To synthesis evaluation of the analgesic and anti-inflammatory activities of pyrazoline bearing 4(3H)-quinazolinone derivatives. Methods: Synthesis of Chalcone (3a-3j) involves the Claisen-Schmidt condensation of equimolar quantities of substituted acetophenone with aromatic aldehyde in the presence of aqueous alkali (10%). Comp. (3a-3j) undergoes cyloaddition reaction with semicarbazide HCl in the presence of suitable solvent to yield comp. (4a-4j). It undergoes addition cyclization reaction with anthranillic acid to yield final comp. (6a-6j). Acute toxicity study of synthesized compound was found according to OECD guidelines 423. The test compound do not showed any toxicity up to 200mg/kg dose. Mortality was not observed during the course of study. The analgesic and anti-inflammatory activity of all synthesized compounds were carried by using hot plate method and Carrageenan induced Rat Paw Edema Method respectively. Results: All compounds synthesized are obtained in crystalline form with good practical yield. The purity and homogeneity of compounds synthesized were determined by sharp melting points and TLC method. The chemical structures were confirmed by FTIR, 1HNMR, and Mass spectrum. Conclusion: The synthesized compound 6b, 6d, 6e, 6i and 6j showed good analgesic and anti-inflammatory activities whereas others showed significant activities. Keywords: Quinazoline, pyrazole, analgesic and anti-inflammatory activity

Preliminary Parametric Investigations into Macro-Laser Polishing of Laser-Directed Energy Deposition of SS 304L Bulk Structures

The higher surface roughness of laser-directed energy deposition (LDED)-built components necessitates advanced and sustainable surface quality enhancement techniques like laser polishing. In the present work, a parametric study involving experimental investigation and numerical analysis is conducted to determine the effect of macro-laser polishing on LDED-built SS 304L structures. A thermophysical model is developed to simulate the effect of laser power and scan speed on the melt pool depth of the LDED-built samples. The simulated melt pool depth is compared with experimental results and is found to be in good agreement. Further, the correlation between the melt pool depth and surface behaviour is studied based on shallow surface melting and shallow over-melting mechanisms. A maximum reduction in surface roughness from 21.3 µm to 9 µm (~57%) is achieved with laser polishing, and process parameters’ effect on the surface roughness is investigated. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) mapping, and X-ray diffraction (XRD) are used to further characterize the laser-polished surface. SEM-EDS analysis shows that the segregation is more evident in laser-polished samples, while the XRD results indicate the absence of phase change during the process. This study paves the way to a greater understanding of the effect of macro-laser polishing on LDED-built SS 304L structures

UTERUS DIDELPHYS IN NULLIPAROUS AND MULTIPAROUS WOMEN – A RARE ENTITY

Uterus didelphys is a rare congenital uterine abnormality in which the embryogenetic fusion of the Mullerian ducts fails to occur. It will lead to the formation of a double uterus with two separate cervices and most often a double vagina with a longitudinal septum as well. Here, we present two different cases of uterus didelphys with varied presentations. The first case is a nulliparous woman presented with post-coital bleeding. On examination, two cervical openings with a longitudinal complete vaginal septum were found, conservative management was done. Findings of didelphys uterus were confirmed on USG. The patient was counseled and discharged. The second case is a multiparous woman with previous cesarean delivery, rupture of membranes, and meconium in this pregnancy with term pregnancy taken up for emergency cesarean section. Dense adhesions and a mass on the right side of uterus were found intraoperatively, which on further inspection confirmed to be patent right horn of uterus. Diagnosis of uterus didelphys was made after doing per speculum and per vaginal examination post-cesarean

“EFFECT OF BODY MASS INDEX ON PREGNANCY OUTCOME” - A PROSPECTIVE STUDY

Background: Mothers who are overweight or obese during pregnancy and childbirth, are known to be at risk of significant antenatal, intrapartum, postpartum, and neonatal complications. Objectives: The objective of the study was to evaluate the impact of high pre pregnancy body mass index (BMI) (<12 weeks of gestation) on the occurrence of maternal pregnancy outcome. A longitudinal observational study was carried out in a tertiary care hospital. In Group I, 50 antenatal women with gestational age <12 weeks BMI 18.5–35 kg/m2 and having singleton pregnancies were included in the study, while 50 women with normal BMI formed the Group II. Both groups were followed up throughout pregnancy and post-natal to assess complication during pregnancy, labor, and puerperium. Results: The mean BMI in Group I and Group II was 27.516 kg/m2 and 21.433 kg/m2. The prevalence of anemia was 40% and 26% among two groups. Antenatal and post-natal complications were gestational diabetes mellitus (Group I - 28% and Group II - 6%), preeclampsia (Group I - 16% and Group II - 2%), required induction of labor (Group I - 26% and Group II - 6%), preterm labor (Group I - 4% and Group II - 16%), and meconium staining of liquor (GroupI-20% and GroupII-12%), and the difference was statistically significant among two groups. Newborn complications were weight ≥2.5 kg (Group I - 74% and Group II - 48%), neonatal intensive care unit admission requirement (Group I - 26% and Group II - 17%), and the difference was statistically significant among two groups. Other complications which were not statistically significant among two groups were oligohydramnios (Group I - 2% and Group II - 4%), polyhydramnios (Group I - 6% and Group II - 4%), and appearance, pulse, grimace, activity, and respiration score at 1 min <7 (Group I - 14% and Group II - 6%). Conclusion: Pregnancy complications related to maternal BMI is a growing problem. Both lean and obese mothers carry an increased risk of adverse perinatal outcome. Given the major economic and medical consequence of pregnancy in these women, all attempts should be made to maintain a normal BMI in women of childbearing age. Pre-pregnancy counseling, health programs and appropriate multidisciplinary management should be done

Metabolic fingerprinting of joint tissue of collagen-induced arthritis (CIA) rat

Rheumatoid arthritis (RA) is a systemic autoimmune disease whose major characteristics persistent joint inflammation that results in joint destruction and failure of the function. Collagen-induced arthritis (CIA) rat is an autoimmune disease model and in many ways shares features with RA. The CIA is associated with systemic manifestations, including alterations in the metabolism. Nuclear magnetic resonance (NMR) spectroscopy-based metabolomics has been successfully applied to the perchloric acid extract of the joint tissue of CIA rat and control rat for the analysis of aqueous metabolites. GPC (Glycerophosphocholine), carnitine, acetate, and creatinine were important discriminators of CIA rats as compared to control rats. Level of lactate (significance; p = 0.004), alanine (p = 0.025), BCA (Branched-chain amino acids) (p = 0.006) and creatinine (p = 0.023) was significantly higher in CIA rats as compared to control rats. Choline (p = 0.038) and GPC (p = 0.009) were significantly reduced in CIA rats as compared to control rats. Choline to GPC correlation was good and negative (Pearson correlation = -0.63) for CIA rats as well as for control rats (Pearson correlation = -0.79). All these analyses collectively considered as metabolic fingerprinting of the joint tissue of CIA rat as compared to control rat. The metabolic fingerprinting of joint tissue of CIA rats was different as compared to control rats. The metabolic fingerprinting reflects inflammatory disease activity in CIA rats with synovitis, demonstrating that underlying inflammatory process drives significant changes in metabolism that can be measured in the joint tissue. Therefore, the outcome of this study may be helpful for understanding the mechanism of metabolic processes in RA. This may be also helpful for the development of advanced diagnostic methods and therapy for RA

Co-existence of gastric adenocarcinoma and neuroendocrine carcinoma: a rare entity

A mixed adenoneuroendocrine carcinoma is a tumor composed of both adenocarcinoma and neuroendocrine carcinoma components, with each comprising  at least one-third of the lesion, as defined by the World Health Organization classification of neuroendocrine neoplasms in 2010.. A 67-years-old male was admitted to the hospital with symptoms suggesting gastric cancer. Histopathology examination from endoscopic biopsy revealed adenocarcinoma. Later partial gastrectomy specimen examination the lesion show presence of well differentiated adenocarcinoma along with neuro endocrine carcinoma.</p

Development and Evaluation of Active Case Detection Methods to Support Visceral Leishmaniasis Elimination in India.

As India moves toward the elimination of visceral leishmaniasis (VL) as a public health problem, comprehensive timely case detection has become increasingly important, in order to reduce the period of infectivity and control outbreaks. During the 2000s, localized research studies suggested that a large percentage of VL cases were never reported in government data. However, assessments conducted from 2013 to 2015 indicated that 85% or more of confirmed cases were eventually captured and reported in surveillance data, albeit with significant delays before diagnosis. Based on methods developed during these assessments, the CARE India team evolved new strategies for active case detection (ACD), applicable at large scale while being sufficiently effective in reducing time to diagnosis. Active case searches are triggered by the report of a confirmed VL case, and comprise two major search mechanisms: 1) case identification based on the index case's knowledge of other known VL cases and searches in nearby houses (snowballing); and 2) sustained contact over time with a range of private providers, both formal and informal. Simultaneously, house-to-house searches were conducted in 142 villages of 47 blocks during this period. We analyzed data from 5030 VL patients reported in Bihar from January 2018 through July 2019. Of these 3033 were detected passively and 1997 via ACD (15 (0.8%) via house-to-house and 1982 (99.2%) by light touch ACD methods). We constructed multinomial logistic regression models comparing time intervals to diagnosis (30-59, 60-89 and ≥90 days with =90 days compared to the referent of <30 days for ACD vs PCD were 0.88, 0.56 and 0.42 respectively. These ACD strategies not only reduce time to diagnosis, and thus risk of transmission, but also ensure that there is a double check on the proportion of cases actually getting captured. Such a process can supplement passive case detection efforts that must go on, possibly perpetually, even after elimination as a public health problem is achieved