Iron and Steel Heritage of Mankind

Early iron encountered by man was meteoritic iron. Some sort of rude man-made iron started appearing around 2000 BC in .many parts of the then known world. Rapid devel-opments in the manufacture and use of iron making took place around 1400 BC in the Hittite federation in modern day Turkey. Socio-political conditions were probably responsible for this. By 1200 BC, knowledge of iron making spread in the east to Assyria and Babylon and in the south to Palestine and Egypt. Towards the west the spread was slower and the Celtic people made an important contribution towards spread of metalworking in Europe including iron-making. In India and China ironmaking probably developed separately and by 600 BC excellent steel was being made in India. This was highly sought after by the Persians, the Romans and others. In China, bronze working developed to very high levels but iron making developed to a lesser extent. However, controlled liquid pig iron production developed in 'China by 200 AD, at least 1200 years before it developed in Europe. Historical developments of modern iron and steel making, seen from the European scenario, starts with early Roman ironworking, development of the Catalan forge, Stuckofen in Germany and the production of liquid pig iron from shaft furnaces by 1400 AD. The next major development was the use of reverberatory furnaces in early 17th century and the use of coke in blast furnaces in the early 18th Century. The period 1700 AD to 1850 AD was a very impo-rtant period in the development of iron making, wrought iron making and steel making. The period saw large scale cast iron production in blast furnaces, refining of the cast iron in refinery furnaces to get improved cast iron and refining in reverberatory furnaces to get some form of wrought iron. Cementation processes and crucible processes for steelmaking developed during this time. A number of such processes were in use in the British Isles during this time. In India also, during this period a number of ironmaking sites were there, each unique in its own way. Bessemer steelmaking was the start of modern steelmaking technology. The development of Bessemer steel making was quickly followed by open hearth steelmaking, basic Bessemer steelmaking and then in 1900 by electric steel-making. After 1950, oxygen steelmaking developed exten-sively. Also, after 1970 direct reduction processes for ironmaking have found their own important place in the scheme of things

Drug resistance in tuberculosis and issues related to multidrug resistance in planning for TB control in India

There is no clear evidence of an increase in the prevalence of initial drug resistance in India over the years. However, relatively high prevalence of acquired resistance has been reported. The level of initial drug resistance is said to be an epidemiological marker to assess the success of the National TB Programme. This also influences the design of the regimens to be employed as well as policy decisions

Drug resistance in tuberculosis in India

The current global concern in the treatment of tuberculosis (TB) is the emergence of resistance to the two most potent drugs viz., isoniazid and rifampicin. The level of initial drug resistance is an epidemiological indicator to assess the success of the TB control programme. Though drug resistance in TB has frequently been reported from India, most of the available information is localized, sketchy or incomplete. A review of the few authentic reports indicates that there is no clear evidence of an increase in the prevalence of initial resistance over the years. However, a much higher prevalence of acquired resistance has been reported from several regions, though based on smaller numbers of patients. A strong TB control programme and continuous surveillance studies employing standardized methodology and rigorous quality control measures will serve as useful parameters in the evaluation of current treatment policies as well as the management of multidrug resistant (MDR) TB cases

Hydrocarbon chain conformation in an intercalated surfactant monolayer and bilayer

Cetyl trimethyl ammonium (CTA) ions have been confined within galleries of layered CdPS3 at two different grafting densities. Low grafting densities are obtained on direct intercalation of CTA ions into CdPS3 to give Cd0.93PS3(CTA)0.14. Intercalation occurs with a lattice expansion of 4.8 Å with the interlamellar surfactant ion lying flat forming a monolayer. Intercalation at higher grafting densities was effected by a two-step ion-exchange process to give Cd0.83PS3(CTA)0.34, with a lattice expansion of 26.5 Å. At higher grafting densities the interlamellar surfactant ions adopt a tilted bilayer structure. 13C NMR and orientation-dependent IR vibrational spectroscopy on single crystals have been used to probe the conformation and orientation of the methylene 'tail' of the intercalated surfactant in the two phases. In the monolayer phase, the confined methylene chain adopts an essentially all-trans conformation with most of the trans chain aligned parallel to the gallery walls. On lowering the temperature, molecular plane aligns parallel, so that the methylene chain lies flat, rigid and aligned to the confining surface. In the bilayer phase, most bonds in the methylene chain are in trans conformation. It is possible to identify specific conformational sequences containing a gauche bond, in the interior and termini of the intercalated methylene. These high energy conformers disappear on cooling leaving all fifteen methylene units of the intercalated cetyl trimethyl ammonium ion in trans conformational registry at 40 K

A Generative-Discriminative Basis Learning Framework to Predict Clinical Severity from Resting State Functional MRI Data

We propose a matrix factorization technique that decomposes the resting state fMRI (rs-fMRI) correlation matrices for a patient population into a sparse set of representative subnetworks, as modeled by rank one outer products. The subnetworks are combined using patient specific non-negative coefficients; these coefficients are also used to model, and subsequently predict the clinical severity of a given patient via a linear regression. Our generative-discriminative framework is able to exploit the structure of rs-fMRI correlation matrices to capture group level effects, while simultaneously accounting for patient variability. We employ ten fold cross validation to demonstrate the predictive power of our model on a cohort of fifty eight patients diagnosed with Autism Spectrum Disorder. Our method outperforms classical semi-supervised frameworks, which perform dimensionality reduction on the correlation features followed by non-linear regression to predict the clinical scores

In vitro activity of ofloxacin and ciprofloxacin against South Indian isolates of M. tuberculosis

Mycobacterium tuberculosis isolates from 104 south Indian patients, including 52 sensitive to Streptomycin (S), Isoniazid, (H) and Rifampicin (R), and 52 resistant to SHR/HR were tested for their in vitro susceptibility to Ciprofloxacin and Ofloxacin on Lowenstein-Jensen medium. The geometric mean for minimal inhibitory concentration (MIC) of Ciprofloxacin was 2.00 mcg/ml for sensitive strains and 2.17 mcg/ml for resistant strains, the overall mean being 2.08 mcg/ml. Considering Ofloxacin, the MICs for the different categories of strains were again similar, there being no difference between sensitive and resistant strains, the geometric means being 2.00 and 2.05 mcg/ml, respectively

In vitro activity of capreomycin and ciprofloxacin against South Indian isolates of M. tuberculosis

Mycobacterium tuberculosis isolated from 107 South Indian patients, including 53 isolates sensitive to Streptomycin (S), Isoniazid (H) and Rifampicin (R) and 54 resistant to SHR/HR were tested for their in vitro susceptibility to Capreomycin and Ciprofloxacin. Of these, 3 (6%) SHR sensitive strains and 8 (15%) SHR/HR resistant strains were probably resistant to Capreomycin. However, the difference did not attain statistical significance. Considering Ciprofloxacin, the percentage distributions of the MIC with the different categories of strains were similar, there being no difference between sensitive and resistant strains, the geometric means being 3.7 and 3.8 mcg/ml, respectively

Evaluation of the BACTEC radiometric method in the early diagnosis of tuberculosis

A comparison of the BACTEC radiometric method with the conventional culture and drug susceptibility testing methods on isolates from clinical specimens in pulmonary and extrapulmonary tuberculosis, childhood TB and TB in HIV-infected individuals was undertaken. In the case of pulmonary TB, the rate of isolation of positive cultures was significantly faster with the BACTEC method, with 87 per cent of the positives being obtained by 7 days, and 96 per cent by 14 days. However, while there was no difference in the total number of positive cultures by the two methods in smear positive pulmonary tuberculosis, in smear negative pulmonary TB, the BACTEC method yielded more number of positive cultures. In extrapulmonary TB, HIV-TB and childhood TB, although the BACTEC method did not yield additional positives, the detection of positives was considerably faster than by the conventional methods, in which the degree of growth was also scanty. The agreement in drug susceptibility tests was 94 per cent for streptomycin and isoniazid, 99 per cent for rifampicin and 91 per cent for ethambutol. Further, most of the drug susceptibility test results became available within 8 days by the BACTEC method. By facilitating early diagnosis, the BACTEC method may prove to be cost effective in a population with a high prevalence of tuberculosis, particularly in the extrapulmonary and paucibacillary forms of the disease

Minimal inhibitory concentrations of sulbactam/ampicillin against drug sensitive and drug resistant isolates of Mycobacterium tuberculosis

A total of 92 isolates of Mycobacteriurn tuberculosis consisting of equal numbers of sensitive and resistant strains was tested for their susceptibility to sulbactam and ampicillin (in the ratio of 1:2) on Lowenstein-Jensen (LJ) and 7H11 agar media. The geometric mean MIC was 63.97 μg/ml for the drug sensitive strains and 65.92 μg/ml for the resistant strains, and the overall mean was 65.01 μg/ml. The high MIC on LJ medium could be attributed to the higher protein content which resulted in greater binding of sulbactam/ampicillin. On the other hand, the geometric mean MIC on 7H11 medium was 26.73 μg/ml for sensitive strains and 23.82 μg/ml for resistant strains; the overall mean being 25.23 μg/ml. Although these MlCs of sulbactamampicillin are higher than those reported earlier, they can be easily achieved in serum. Further studies on experimental tuberculosis and in humans will be needed to prove the efficacy of sulbactam/ampicillin in the treatment of patients with multidrug resistant tuberculosis