Fast design optimization of UWB antenna with WLAN Band-Notch

In this paper, a methodology for rapid design optimization of an ultra-wideband ( UWB) monopole antenna with a lower WLAN band-notch is presented. The band-notch is realized using an open loop resonator implemented in the radiation patch of the antenna. Design optimization is a two stage process, with the first stage focused on the design of the antenna itself, and the second stage aiming at identification of the appropriate dimensions of the resonator with the purpose of allocating the band-notch in the desired frequency range. Both optimization stages are realized using surrogate-based optimization involving variable-fidelity electromagnetic ( EM) simulation models as well as an additive response correction ( first stage), and sequential approximate optimization ( second stage). The final antenna design is obtained at the CPU cost corresponding to only 23 high-fidelity EM antenna simulations

Cost-efficient modeling of antenna structures using Gradient Enhanced Kriging

Reliable yet fast surrogate models are indispensable in the design of contemporary antenna structures. Data-driven models, e.g., based on Gaussian Processes or support-vector regression, offer sufficient flexibility and speed, however, their setup cost is large and grows very quickly with the dimensionality of the design space. In this paper, we propose cost-efficient modeling of antenna structures using Gradient-Enhanced Kriging. In our approach, the training data set contains, apart from the EM-simulation responses of the structure at hand, also derivative data at the respective training locations obtained at little extra cost using adjoint sensitivity techniques. We demonstrate that introduction of the derivative information into the model allows for considerable reduction of the model setup cost (in terms of the number of training points required) without compromising its predictive power. The Gradient-Enhanced Kriging technique is illustrated using a dielectric resonator antenna structure. Comparison with conventional Kriging interpolation is also provided

Cerebrospinal fluid lysozyme in the diagnosis of tuberculous meningitis

Pretreatment lysozyme levels in cerebrospinal fluid (CSF) were estimated in 37 patients with tuberculous meningitis (TBM), 16 with non-tuberculous meningitis (non-TBM) and 13 with non-inflammatory conditions of the central nervous system (controls) in an attempt to assess the role of CSF lysozyme in the diagnosis of TBM. Lysozyme content in the CSF was found to be elevated in all patients with bacteriologically confirmed TBM and in a large proportion of patients in whom the disease was clinically diagnosed but bacteriologically not confirmed. The enzyme was not detected in all but one of the control subjects and in most (69%) of the non-TBM patients

Single strand conformation polymorphism profiles with biotinylated PCR products to detect mutations in rpoB gene of Mycobacterium tuberculosis

A fragment of the rpoB gene, including the region shown to be involved in rifampicin resistance, was amplified from 15 rifampicin-resistant and 6 rifampicin- sensitive clinical isolates of Mycobacterium tuberculosis by the polymerase chain reaction (PCR). One of the primers, employed in PCR, was biotinylated. The biotinylated strand of the PCR product was separated from the unbiotinylated strand using streptavidin magnetic beads. Both the strands were subjected to single strand conformation polymorphism in polyacrylamide gel electrophoresis. The DNA bands were silver stained to study their migration pattern. A shift in the migration of either of the strands of the test strain compared to the strands from a control rifampicin-sensitive strain was considered as indicative of resistance. This strategy was found to ease the visualization of shift in the migration of the strands in 17 of 21 samples and thereby detection of mutations

Transportation of lymph node biopsy specimens in selective Kirchner’s liquid medium for culture of tubercle bacilli

Lymph node biopsy specimens, obtained from 297 paediatric and adult patients with tuberculous lymphadenitis at Madurai, were transported in selective Kirchner’s liquid medium (KL-T) to the Tuberculosis Research Centre, Madras and processed for culture. Mycobucterium tuberculosis was isolated from 201 (68%) specimens. Of the 192 specimens received within 4 days of resection, 134 (69.8%) yielded M. tuberculosis on culture and of the 105 specimens received after 5 days, 67 (63.8%) were culture positive; the difference was not statistically significant. By incubating KL-T alone further, after removing the gland for processing, it was found that mere contact with the excised node during transportation was enough to retrieve 77 (38.3%) of the total of 201 positive isolates obtained, the delay did not affect the culture positivity rate. Thus, lymph node specimens for culture of tubercle bacilli can be stored in the refrigerator for up to 15 days and transported in KL-T at ambient temperature for 18-20 h without any loss in culture positivity

A novel method of staining acid-fast bacilli in sputum containers

Background & objectives: Making centrifuged deposit smears from sputum to detect acid-fast bacilli (AFB) is considered hazardous. We carried out this study to stain the centrifuged deposits with carbol-fuchsin in sputum containers and to decolourize and counterstain their smears made on glass slides. Methods: The centrifuged deposits of 180 sputum samples from pulmonary tuberculosis patients were used for making smears (initial deposit smears) and staining by Ziehl-Neelsen (ZN) method for the detection of AFB. Each of the sputum deposit was then treated with one ml of 1 per cent carbol-fuchsin and a smear made between 2 to 3 h was then decolourized and counterstained by the same procedures followed in ZN method (2 h stained deposit smear). The coded initial deposit smears and the corresponding 2 h stained deposit smears were read by the same readers and the results compared. Results: One hundred and fifty (70 positive and 80 negative) 2 h stained deposit smears were compared with initial deposit smears and the difference was not statistically significant. Interpretation & conclusion: Centrifuged deposits of sputum in sputum containers can be stained by carbol-fuchsin within 2-3 h and their smears made subsequently on glass slides can then be decolourized and counterstained by the procedures followed in ZN method for detection of AFB by light microscopy