Phenomenological and statistical analyses of turbulence in forced convection with temperature-dependent viscosity under non-Boussinesq condition

In this work, Thermal Large Eddy Simulation (TLES) is performed to study the behavior of weakly compressible Newtonian fluids with anisotropic temperature-dependent viscosity in forced convection turbulent flow. A systematic analysis of variable-viscosity effects, isolated from gravity, with relevance to industrial cooling/heating applications is being carried out. A LES of a planar channel flow with significant heat transfer at a low Mach number was performed to study effects of fluid property variation on the near-wall turbulence structure. In this flow configuration the top wall is maintained at a higher temperature (T hot ) than the bottom wall (T cold ). The temperature ratio (R θ = T hot /T cold ) is fixed at 1.01, 2 and 3 to study the effects of property variations at low Mach number. Results indicate that average and turbulent fields undergo significant changes. Compared with isothermal flow with constant viscosity, we observe that turbulence is enhanced in the cold side of the channel, characterized by locally lower viscosity whereas a decrease of turbulent kinetic energy is found at the hot wall. The turbulent structures near the cold wall are very short and densely populated vortices but near the hot wall there seems to be a long streaky structure or large elongated vortices. Spectral study reveals that turbulence is completely suppressed at the hot side of the channel at a large temperature ratio because no inertial zone is obtained (i.e. index of Kolmogorov scaling law is zero) from the spectra in these region.

Investigation of spectroscopic properties, structure and luminescence spectra of Sm3+ doped zinc bismuth silicate glasses

The glasses with compositions 20ZnO·(79.5-x)Bi2O3·xSiO2·0.5Sm2O3 (10≤x≤50, mol%) have been synthesized using normal melt-quench technique. Optical absorption and fluorescence spectra of the glasses were recorded at ambient temperature. Judd-Ofelt (J-O) theory has been successfully applied to characterize the absorption and luminescence spectra of these glasses. From the measured intensities of absorption bands of these glasses, the Judd-Ofelt parameters, Ωλ (λ=2, 4, 6) have been evaluated. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth (RE) ion site (due to structural change) and to changes in RE-O covalency, whereas the variation of Ω6 is found to be strongly dependent on nephlauxetic effect. The shift of the hypersensitive band shows that the covalency of the RE-O decreases with decrease in Bi2O3 content in the host glass. Also, using J-O theory various radiative properties like spontaneous emission probability (Arad), radiative life time (τr), fluorescence branching ratio (βr) and stimulated emission cross-section (σ) for various emission bands of these glasses in the visible spectral region have been determined. A close correlation is observed between the Bi2O3 content and the spectroscopic, radiative and structural properties of the prepared glasses. The values of radiative properties indicated that 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions responsible for orange luminescence might be used in the development of materials for LED's and other optical devices in the visible region.

Effect of Bi2O3 on spectroscopic and structural properties of Er3+ doped cadmium bismuth borate glasses

Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150°C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters Ω(λ) (λ=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (τ(R)), branching ratios (β(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (σ(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)→(4)I(15/2) at 1.506 μm in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication.

Immune reconstitution inflammatory syndrome in leprosy

Immune reconstitution inflammatory syndrome (IRIS) is a paradoxical deterioration in the clinical status of a patient infected with human immunodeficiency virus (HIV) on highly active antiretroviral treatment (HAART). The immune suppression caused by the virus can initially suppress the clinical manifestations of leprosy which can then be unmasked after treatment with HAART or an inflammatory reaction can occur in the initial months of therapy, resulting from dysregulated recovery of immunity to specific antigens. Both these conditions are identified as IRIS in leprosy. Though this syndrome is a widely recognized entity presently, there is still a lack of universally acceptable diagnostic criteria for the condition. The first case published case of leprosy- associated immune reconstitution disease was reported in 2003 and about 47 confirmed cases of IRIS in leprosy have been reported since then, mostly from Brazil and India. Anti-inflammatory drugs and steroids are the drugs of choice in inflammatory episodes with continuation of antiretroviral therapy. With increasing affordability of antiretroviral therapy, clinicians will put more and more number of human immunodeficiency virus infected patients on therapy and hence an increase in the incidence of IRIS is expected. Therefore, it is important to understand all facets of this syndrome which is becoming more prevalent with each passing day.

Stigma in leprosy: miles to go!

No disease has been more closely associated with stigma than leprosy such that it has become a metaphor for stigma. Stigma has been difficult to measure and little research has been done on this issue. Stigma reduction has not been an important component of anti-leprosy program. The study was undertaken to measure the stigma associated with leprosy by using P scale which is used for assessing participation restriction of those affected by the disease. This comparative questionnaire based study was carried out in two sets of patients. Two groups of 30 patients each were studied. First group belonged to a Government run Leprosarium and group two from a tertiary care skin and leprosy centre. The study used the Participation (P) scale and data was collected by interviewing the patients. Participation restriction was defined as any score equal to and more than 13. Participation restriction was observed in 27 (90%) cases of group 1while participation restriction was present in only 7 (23.3%) subjects of group 2. It was observed that mean score of participation restriction in group 1 was quite high at 31.9 while it was only 8.3 for group 2. The participation restriction was directly related to the duration of disease and the grade of disability. Longer the duration of disease, greater was the likelihood of restriction. The participation restriction was found to be negatively correlated with the education. Recommendation about prevention of disability would require program about early diagnosis of nerve damage and subsequent action at the patient-family-community level and health care providers.

Structural investigation and electron paramagnetic resonance of vanadyl doped alkali niobium borate glasses

Glasses with compositions xNb(2)O(5).(30-x)M(2)O.69B(2)O(3) (where M=Li, Na, K; x=0, 4, 8 mol%) doped with 1 mol% V(2)O(5) have been prepared using normal melt quench technique. The IR transmission spectra of the glasses have been studied over the range 400-4000 cm(-1). The changes caused by the addition of Nb(2)O(5) on the structure of these glasses have been reported. The electron paramagnetic resonance spectra of VO(2+) ions in these glasses have been recorded in X-band (9.14 GHz) at room temperature (300 K). The spin Hamiltonian parameters, dipolar hyperfine coupling parameter and Fermi contact interaction parameter have been calculated. It is observed that the resultant resonance spectra contain hyperfine structures (hfs) due to V(4+) ions which exist as VO(2+) ions in octahedral coordination with a tetragonal compression in the present glasses. The tetragonality of V(4+)O(6) complex decreases with increasing concentration of Nb(2)O(5). The 3d(xy) orbit contracts with increase in Nb(2)O(5):M(2)O ratio. Values of the theoretical optical basicity, Lambda(th), have also been reported.

Study of optical band gap and FTIR spectroscopy of Li2O.Bi2O3.P2O5 glasses

Glasses having composition (25+x)Li(2)O.(65-x)P(2)O(5).10Bi(2)O(3) (0< or =x< or =25 mol%) were prepared by normal melt quenching technique. The optical absorption spectra of the polished samples were recorded in spectral range from 200 to 3300 nm at room temperature. The optical absorption edge (lambda(cutoff)), optical band gap (E(g)) and Urbach energy (DeltaE) were determined from the absorption spectra. Variation in these optical parameters has been associated with the structural changes occurring in these glasses with increase in Li(2)O:P(2)O(5) ratio. Variation in density (D), molar volume (V(M)) and glass transition temperature (T(g)) has also been correlated with structural changes in the glass samples. The FTIR spectra have been recorded in the spectral range from 400 to 1400 cm(-1). The FTIR spectra show the rapid depolymerization of phosphate chains with increase in Li(2)O content and P-O-Bi bonds are formed.

Structural, optical, physical and electrical properties of V2O5.SrO.B2O3 glasses

The present work aims to study the structure and variation of optical band gap, density and dc electrical conductivity in vanadium strontium borate glasses. The glass systems xV2O5.(40-x)SrO.60B2O3 and xV2O5.(60-x)B2O3.40SrO with x varying from 0 to 20 mol% were prepared by normal melt quench technique. Structural studies were made by recording IR transmission spectra. The fundamental absorption edge for all the glasses was analyzed in terms of the theory proposed by Davis and Mott. The position of absorption edge and hence the value of the optical band gap was found to depend on the semiconducting glass composition. The absorption in these glasses is believed to be associated with indirect transitions. The origin of Urbach energy is associated with the phonon-assisted indirect transitions. The change in both density and molar volume was discussed in terms of the structural modifications that take place in the glass matrix on addition of V2O5. dc conductivity of the glass systems is also reported. The change of conductivity and activation energy with composition indicates that the conduction process varies from ionic to polaronic one.

Study of EPR, optical properties and electrical conductivity of vanadyl doped Bi2O3.PbO.B2O3 glasses

Heavy metal based oxide glasses having composition xBi(2)O(3).(0.30 - x)PbO.0.70B(2)O(3) have been prepared (0.00 < or = x < or = 0.15, mol%) containing 2.0mol% of V(2)O(5) by normal melt-quenching technique. Electron paramagnetic resonance (EPR), optical spectra and dc conductivity of these glasses have been studied. Spin Hamiltonian parameters (SHP) of VO(2+) ions, dipolar hyperfine parameter, P and Fermi contact interaction parameter, K, molecular orbital coefficients (alpha(2) and gamma(2)) and optical band gap have been calculated. It is observed that in these glasses, the tetragonal nature of V(4+)O(6) complex increases with Bi(2)O(3) content. Increase in Bi(2)O(3):PbO ratio results in the contraction of 3d(xy) orbit of the unpaired electron in the vanadium ion, and the SHP are dependent on the theoretical optical basicity, Lambda(th). In present glasses, the conductivity (activation energy) first decreases (increases) with increase in mol% of Bi(2)O(3) content upto x = 0.08 and then shows a maxima (minima) at x = 0.10 and then starts decreasing (increasing) upto x < or = 0.15 with mol% of Bi(2)O(3) content.

Non-syndrome multiple supplemental supernumerary teeth

Multiple supernumerary teeth without any associated systemic conditions or syndromes are not common. We document a case of non-syndrome multiple supplemental supernumerary teeth in mandibular premolar region of an adolescent male patient, an incidental findings during routine radiographic examination. Periodic examination is recommended to monitor the clinical behavior.

Clinical and bacteriological study of urethral discharge

A clinics-bacteriological study of 52 patients with urethritis was carried out. All the patients were evaluated clinically and bacteriologically at the beginning and end of the treatment. Majority of the patients belonged to the age group 21-30 years (58%). Incidence of gonococcal urethritis was 65% and Non gonococcal Urethritis (NGU) 35%. The common organisms causing NGU were chlamydia (28%) ureaplasma (11%) and mycoplasma (11%). Neisseria gonorrhoea was resistant to penicillin in (38%), ciprolloxacin in 67, and to noriloxaein in 6% cases. High incidence of HIV positivity was found in gonorrhoea (21%).

cDNA and genomic cloning of lacritin, a novel secretion enhancing factor from the human lacrimal gland

Multiple extracellular factors are hypothesized to promote the differentiation of unstimulated and/or stimulated secretory pathways in exocrine secretory cells, but the identity of differentiation factors, particularly those organ-specific, remain largely unknown. Here, we report on the identification of a novel secreted glycoprotein, lacritin, that enhances exocrine secretion in overnight cultures of lacrimal acinar cells which otherwise display loss of secretory function. Lacritin mRNA and protein are highly expressed in human lacrimal gland, moderately in major and minor salivary glands and slightly in thyroid. No lacritin message or protein is detected elsewhere among more than 50 human tissues examined. Lacritin displays partial similarity to the glycosaminoglycan-binding region of brain-specific neuroglycan C (32 % identity over 102 amino acid residues) and to the possibly mucin-like amino globular region of fibulin-2 (30 % identity over 81 amino acid residues), and localizes primarily to secretory granules and secretory fluid. The lacritin gene consists of five exons, displays no alternative splicing and maps to 12q13. Recombinant lacritin augments unstimulated but not stimulated acinar cell secretion, promotes ductal cell proliferation, and stimulates signaling through tyrosine phosphorylation and release of calcium. It binds collagen IV, laminin-1, entactin/nidogen-1, fibronectin and vitronectin, but not collagen I, heparin or EGF. As an autocrine/paracrine enhancer of the lacrimal constitutive secretory pathway, ductal cell mitogen and stimulator of corneal epithelial cells, lacritin may play a key role in the function of the lacrimal gland-corneal axis.

Quantitation of rat lacrimal secretion: a novel sandwich ELISA with high sensitivity

Modulation of lacrimal acinar cell tear secretion may involve multiple factors acting both in subtle and pronounced ways. Functional screens of recombinant protein products arising from gene array technologies, or protein fractions derived from lacrimal conditioned media or extracellular matrix, will require a highly sensitive assay capable of monitoring tear protein secretion by small replicate cultures. To improve significantly on current methods, a rat- and mouse-specific sandwich ELISA was developed. For this purpose, chickens and rabbits were immunized with serum-free secretion media from carbachol and VIP-stimulated rat lacrimal acinar cell cultures. Immune sera were characterized by ELISA, Western blotting and immunohistochemistry, and subsequently optimized for use in a sandwich ELISA. Both antisera detected a wide range of different rat tear proteins, and immunostained only the secretory granule-rich juxtalumenal region in sections of rat lacrimal gland. Chicken, but not rabbit, antiserum cross-reacted with rabbit and human tears. In sandwich ELISA, capture with purified chicken immunoglobulin fraction and detection with rabbit antiserum detected as little as 1 ng ml-1 tear protein in 10,000-fold diluted rat secretion medium--a level of sensitivity 8000 times greater than the rat tear peroxidase assay. Such specificity and sensitivity greatly reduce the quantity of media needed for assay, and makes feasible functional screens for scarce factors that may influence lacrimal secretory processes, and in turn possibly play a role in human lacrimal insufficiency syndromes.

PATTERN OF SEXUALLY TRANSMITTED DISEASES IN THE ARMED FORCES

Pattern of sexually transmitted diseases (STDs) in 1027 male patients admitted during 1990 to 1996 were analysed. Majority of cases (86%) were in age group of 20 to 40 years. Out of total 1027 STD cases 334 (32%) were having chancroid, 237 (23%) syphilis, 122 (11.9%) lymphogranuloma venereum, 130 (12.6%) gonorrhoea, 34 (3.3%) Herpes genitalis and 170 (16.5%) other STDs. 167 STD cases (163%) were found to have HIV infection. A rising trend in prevalence of HIV infection in STD patients from 2.8% (1990) to 27.8 (1996) was noticed contrary to declining trend of STDs from 213 cases in 1990 to 79 cases in 1996. The prevalence of HIV infection was 303% in LGV, 19.3% in chancroid, 13.5% in syphilis, 17.6% in herpes genitalis, 6.7% in gonorrhoea and 11.2% in other STD cases. Out of total 167 STD cases having HIV infection 65 (40%) cases were of chancroid, 37 (22.2%) of LGV, 32(19.2%) of syphilis, 8 (4.8) of gonorrhoea, and 6(3.6%) of herpes genitalis while 17 (10.2) cases were having other STDs.

Hiv infection in patients of sexually transmitted disease

A total of 1027 male patients suffering from sexually transmitted diseases (STD) during 1990 to 1996 were screened for HIV infection. All cases were in the age group 17 years to 48 years. One hundred and sixty-seven STD cases (16.3%) were found to have HIV infection. A rising trend in incidence of HIV infection in STD patients from 1990 (2.8%) to 1996 (27.8%) was noticed countrary to declining trend of STDs from 213 cases in 1990 to 79 cases in 1996. The incidence of HIV infection was 30.3% in lymphogranuloma venereum, 19.5% in chancroid, 13.5% in syphilis, 17.6% in herpes genitatis, 6.7% in gonorrhoea and 11.2% in other STD cases.

Precipitation test--a rapid method for diagnosis of tuberculous meningitis

Precipitation test (modified Lavinson's test) was conducted in 125 cases of meningitis. Of these, 50 cases (proved cases of tuberculous meningitis) who served as positive controls showed positive response for the precipitation test in 96% and in 25 cases of negative control group (cases of meningitis other than TBM), it showed only 4% positivity. The remaining 50 cases of TBM where the cytological and biochemical findings were not in correlation with clinical diagnosis of TBM, showed 92% positivity for early diagnosis of TBM.