Studies on buried layer resistors

Multilayer thick-film technology is one of the important technologies adopted in the miniaturization of electronic systems. Generally, only interconnections are made in the intermediate layers. The possibility of fabricating resistors along with interconnections in the buried layers/intermediate layers using conventional thick-film materials has been examined in this study. The fabrication has been carried out by processing layer after layer. It has been found that the buried layer resistors exhibited a sheet resistivity lower than those fabricated as open resistors. This change in sheet resistivity has been attributed to multiple firings that the resistors undergo during the fabrication. This reduction in sheet resistivity has been found to be due to segregation of active materials. A model has been proposed to explain this change in sheet resistivity through segregation of the active material. The work reported in the paper clearly indicates that buried resistors with consistent values (+/-10%) can be fabricated using conventional materials. However, the design of the resistors has to be carried out using modified sheet resistivities. The model that is proposed also indicates how one can make a paste that is likely to exhibit the same sheet resistivity for buried resistors and open resistors. (C) 2002 Kluwer Academic Publishers

MULTIPLE PULMONARY ARTERY ANEURYSMS : A CASE REPORT OF PULMONARY VASCULITIS

CLINICAL HISTORY Presenting history – A 24 year old male patient came with complaints of haemoptysis since 3months, aggravated on exertion around 3-4 episodes per day with around 3-4 ml of frank blood. No complaint of chest pain/ fever. No past history of PTB. No e/o significant past history. Patient tested negative for HLA b51 and Anti-nuclear antibody

DIAGNOSTIC DILEMMA: SCHWANNOMA OR GANGLION CYST

Schwannomas are rare, slow growing benign tumors of peripheral nerve sheath originating from Schwann cells surrounding the nerve associated with delayed presentation of pain and paresthesia. Their incidence being 5% of all upper extremity tumors. They may be a part of neurofibromatosis called schwannomatosis with multiple peripheral schwannomas. We present a case of solitary schwannomas from the peripheral nerves probably superficial branch of median nerve mistaken initially for ganglion cyst

Central Venous Catheter-Associated Pericardial Tamponade in a 6-Day Old: A Case Report

Introduction. Pericardial effusion (PCE) and tamponade can cause significant morbidity and mortality in neonates. Such cases have been reported in the literature in various contexts. Case Presentation. A 6-day old neonate with meconium aspiration syndrome and persistent pulmonary hypertension of newborn on high frequency oscillator ventilation and inhaled nitric oxide was referred to our hospital with a large pericardial effusion causing hemodynamic compromise. Prompt pericardiocentesis led to significant improvement in the cardio-respiratory status and removal of the central line prevented the fluid from reaccumulating. Cellular and biochemical analysis aided in the diagnosis of catheter related etiology with possibility of infusate diffusion into the pericardial space. Conclusion. We present this paper to emphasize the importance of recognizing this uncommon but serious complication of central venous catheters in intensive care units. We also discuss the proposed hypothesis for the mechanism of production of PCE

Acute necrotizing encephalopathy in a young adult with EBV and COVID19 co-infection: A case report

Clinical history: A 22yr old female came with complaints of fever and altered sensorium since 2 days. Serology showed positive for Epstein-Barr virus (EBV) and COVID-19 IgG antibodies. Laboratory investigations revealed elevated total counts & inflammatory markers

Synthesis and liquid crystalline behaviour of substituted (E)-phenyl-4-(phenyldiazenyl) benzoate derivatives and their photo switching ability

Azobenzene derivatives containing phenyl/4-halogen-phenyl 4-{(E)-[4-(pent-4-en-1-yloxy)phenyl] diazenyl}benzoate group with different electronegative substituent (H, F, Cl, Br and I) at other end was synthesised. These azo-based benzoate derivatives have been characterised by FTIR, 1H-NMR, 13C-NMR, elemental analyser, POM and UV-Vis spectroscopy. Photosaturation at 358 nm obtained after 82 s of UV irradiation and the longest thermal back relaxation time of 45 h recorded by UVVis. The azo derivative could be possible photolock under UV light, as observed by the improved thermal back relaxation time. The resulting photolockable chain of azobenzene might prove valuable in the development of optical device application. These azobenzene moieties also exhibit liquid crystalline behaviour with respect to the halogen substitution as an electron withdrawing group shows that strong structure property relationship exists among them

Generation of a Retinoblastoma (Rb)1-inducible dominant-negative (DN) mouse model.

Retinoblastoma 1 (Rb1) is an essential gene regulating cellular proliferation, differentiation, and homeostasis. To exert these functions, Rb1 is recruited and physically interacts with a growing variety of signaling pathways. While Rb1 does not appear to be ubiquitously expressed, its expression has been confirmed in a variety of hematopoietic and neuronal-derived cells, including the inner ear hair cells (HCs). Studies in transgenic mice demonstrate that complete germline or conditional Rb1 deletion leads to abnormal cell proliferation, followed by massive apoptosis; making it difficult to fully address Rb1\u27s biochemical activities. To overcome these limitations, we developed a tetracycline-inducible TetO-CB-myc6-Rb1 (CBRb) mouse model to achieve transient and inducible dominant-negative (DN) inhibition of the endogenous RB1 protein. Our strategy involved fusing the Rb1 gene to the lysosomal protease pre-procathepsin B (CB), thus allowing for further routing of the DN-CBRb fusion protein and its interacting complexes for proteolytic degradation. Moreover, reversibility of the system is achieved upon suppression of doxycycline (Dox) administration. Preliminary characterization of DN-CBRb mice bred to a ubiquitous rtTA mouse line demonstrated a significant inhibition of the endogenous RB1 protein in the inner ear and in a number of other organs where RB1 is expressed. Examination of the postnatal (P) DN-CBRb mice inner ear at P10 and P28 showed the presence of supernumerary inner HCs (IHCs) in the lower turns of the cochleae, which corresponds to the described expression domain of the endogenous Rb1 gene. Selective and reversible suppression of gene expression is both an experimental tool for defining function and a potential means to medical therapy. Given the limitations associated with Rb1-null mice lethality, this model provides a valuable resource for understanding RB1 activity, relative contribution to HC regeneration and its potential therapeutic application

Single-dose pharmacokinetics of isoniazid and rifampicin in patients with chronic renal failure

The pharmacokinetics of Isoniazid and Rifampicin were studied in 18 patients with mild or moderate renal failure (creatinine clearance : 10.1-50.0 ml/min) and 17 patients with severe renal failure (creatinine clearance < 10.0 ml/min) and the findings compared with those in 16 healthy subjects. The renal excretion of Isoniazid, Acetylisoniazid, Rifampicin and Dcsacetylrifampicin was severely inhibited in patients with renal failure. Plasma Rifampicin and Isoniazid concentrations in rapid acetylators were similar in healthy subjects and both the groups of patients. In slow acetylators, plasma Isoniazid concentrations and exposure (AUC) and half-life of the drug, calculated on the basis of these concentrations were appreciably higher in patients than in healthy subjects (P < 0.01); the mean values in the two groups of patients were, however, similar. The correlations between plasma creatinine or creatinine clearance and peak concentration, exposure or half-life of Isoniazid were poor (r < 0.28) in the slow acetylators. These findings suggest that in patients with renal failure, it is not necessary to reduce dosage of Rifampicin or of Isoniazid in rapid acetylators but advisable in respect of Isoniazid in slow acetylators to lessen the risk of toxic reactions