Unraveling the Role of Π - Conjugation in Thiophene Oligomers for Optoelectronic Properties by DFT/TDDFT Approach

ABSTRACT Thiophene oligomer has been investigated using DFT/TDDFT calculations with an aim to check its suitability for opto electronic applications and also to analyse the influence of π-bridge. Our results revealed that thiophene oligomers have excellent π-conjugation throughout. FMO analysis give an estimate of band gap of thiophene oligomer and further revealed HOMO are localized on π - bridge, donor group and LUMO are localized on π - bridge and acceptor group. A TDDFT calculation has been performed to understand the absorption properties of them in gas phase and solvent phase. PCM calculations convey that absorption maxima show positive solvatochromism. Among the designed candidates, the one with more π - bridge show higher wavelength of absorption maxima and would be a choice for better optoelectronic materials. NBO analysis provides support for complete delocalization in these systems. It is interesting to note that oligomer with more π-bridge display an enhanced optoelectronic properties than with less π - bridge.

Investigation of Structural, Morphological, Magnetic Properties and Biomedical applications of Cu2+ Substituted Uncoated Cobalt Ferrite Nanoparticles

ABSTRACT In the present work, Cu2+ substituted cobalt ferrite (Co1-xCuxFe2O4, x = 0, 0.3, 0.5, 0.7 and 1) magnetic nanopowders were synthesized via chemical co-precipitation method. The prepared powders were investigated by various characterization methods such as X-ray diffraction analysis (XRD), scanning electron microscope analysis (SEM), vibrating sample magnetometer analysis (VSM) and fourier transform infrared spectroscopy analysis (FTIR). The XRD analysis reveals that the synthesized nanopowders possess single phase centred cubic spinel structure. The average crystallite size of the particles ranging from 27-49 nm was calculated by using Debye-scherrer formula. Magnetic properties of the synthesized magnetic nanoparticles are studied by using VSM. The VSM results shows the magnetic properties such as coercivity, magnetic retentivity decreases with increase in copper substitution whereas the saturation magnetization shows increment and decrement in accordance with Cu2+ substitution in cobalt ferrite nanoparticles. SEM analysis reveals the morphology of synthesized magnetic nanoparticles. FTIR spectra of Cu2+ substituted cobalt ferrite magnetic nanoparticles were recorded in the frequency range 4000-400cm-1. The spectrum shows the presence of water adsorption and metal oxygen bonds. The adhesion nature of Cu2+ substituted cobalt ferrite magnetic nanoparticles with bacteria in reviewed results indicates that the synthesized nanoparticles could be used in biotechnology and biomedical applications.

Phytochemical constituent of aconitum species-A review.

Aconitum species were used as the major component in the Chinese and Bhutanese herbal medicines. The species posses many phytochemical compounds which possess many of the pharmacological activities. Diterpene alkaloids were the main compound with the pharmacological activities such as analgesic and against inflammation. This alkaloid possesses certain toxic hydrolyzed bases which could be detoxified by the intervention of recent technologies. Apart from this, the plant possess many alkaloids, amide alkaloids, flavonoids, flavonol glycosides, diterpenoid and norditerpenoid compounds which possess medicinal values. The above mentioned compounds of potent importance were isolated and characterized by the chromatographic separation techniques and their structures were usually elucidated by the spectroscopic studies especially with Nuclear Magnetic Resonance techniques. These compounds were the central target of the medicinal chemist as they possess both medicinal and toxic nature. The measures to be taken in such a way that the medicinal compounds of the plant should be isolated and formulated without the toxic nature. This review encompasses the total phytochemical compounds that have been isolated from various species of the plant genus Aconitum.

A pilot study on hyperinsulinaemic euglycaemic clamp based insulin sensitivity in young adult Indian males with low body mass index.

Background & objectives: Indians have decreased insulin sensitivity (IS) and a greater adiposity at a lower body mass index (BMI) when compared with other ethnic groups. Despite this, IS has not been studied in Indians of low BMI. This study thus used the hyperinsulinaemic euglycaemic clamp (HEC) technique to compare IS in young normal weight (NW) and low BMI (LBMI) Indian males. Clamp IS was also compared with convenient indices of insulin sensitivity such as the homeostatic model assessment (HOMA). In the NW group, clamp IS was compared with published data of similarly measured IS in other studies and ethnic groups. Methods: Ten NW [body mass index (BMI): 18.5-25 kg/m2] and ten LBMI (BMI < 18.5 kg/m2) young healthy Indian males aged between 19-32 yr were recruited through advertisements from Bangalore slums. Fasting plasma glucose and insulin, glucose disposal rates (GDR) and IS were the parameters measured during the HEC technique. Results: The NW group had a Clamp IS of 4.5 (3.8, 5.3) (median, lower, upper quartile, mg/(kg. min)/μU/ml) that was close to half that of the LBMI group; 9.9 (7.1, 13.4: P<0.001). Clamp IS in the NW group was significantly lower than that observed in published studies involving other ethnic groups (P<0.05). Clamp IS and per cent body fat (% BF), were significantly and negatively correlated (n=20, ρ = -0.7, P<0.001). Correlations between Clamp IS and other IS indices ranged from ρ = -0.5 for HOMA2-%B to ρ = 0.5 for HOMA2-%S (P<0.05); however, the correlation with HOMA1-IR was not significant (ρ = 0.4). Interpretation & conclusions: The significantly lower Clamp IS of the NW group compared with the LBMI group and other ethnic groups indicated that IS was impaired in Indians at relatively low BMIs. Most of the convenient indices of IS were significantly correlated with Clamp IS, however, the Clamp IS was more sensitive method with greater discriminatory power, since IS differences between LBMI and NW groups were only apparent with Clamp IS.

In vitro effect of four herbal plants on the motility of Brugia malayi microfilariae.

BACKGROUND & OBJECTIVE: Disease burden due to lymphatic filariasis is disproportionately high despite mass drug administration with conventional drugs. Usage of herbal drugs in traditional medicine is quite well known but largely empirical. Hence the present study was designed to screen the in vitro antifilarial effect of four herbal plants on Brugia malayi. METHODS: Motility of microfilariae of B. malayi after incubation for 48 h with aqueous/methanol extracts of Vitex negundo L. (roots), Butea monosperma L. (roots and leaves), Ricinus communis L. (leaves), and Aegle marmelos Corr. (leaves) was explored in the concentration range of 20 to 100 ng/ml for possible antifilarial effect by comparing with suitable solvent control. RESULTS: Butea monosperma leaves and roots, Vitex negundo root and Aegle marmelo leaves showed significant inhibition of motility of microfilariae as compared to controls whereas inhibitory activity demonstrated by Ricinus communis L. leaves was not significant. Antifilarial effects imparted by all these extracts were found to be a function of their relative concentrations. Inhibitory concentrations (IC(50)) for the plant extracts with significant antifilarial activity against Brugia malayi microfilariae in in vitro system have been derived to be 82, 83 and 70 ng/ml for Vitex negundo L., Butea monosperma L. and Aegle marmelos Corr. respectively. INTERPRETATION & CONCLUSION: The present study recorded significant antifilarial effect of all plant extracts studied except for Ricinus communis L. leaves and contributes to the development of database for novel drug candidates for human lymphatic filariasis.

Tobacco survey among youth in South India.

BACKGROUND: Smoking of cigarettes and, particularly, of "bidis" (which consist of about 0.2-0.3 gm of tobacco rolled up in the leaf of another plant (temburni) has been widespread for many decades among men in India. There have, however, been no substantial studies on the prevalence of tobacco use among youth in India. Hence a Global Youth Tobacco Survey was conducted in schools in Tamil Nadu as part of on-going Global Youth Tobacco survey in over 150 countries in the world. METHODS: The two-stage cluster sample method was used to select 100 schools with standards 8, 9 and 10 in Tamil Nadu. The survey used self administered questionnaires, which consisted of 88 multiple choice questions. RESULTS: A total of 4820 students participated (a response rate of 90.1%) in the 99 of 100 schools selected for the survey. About 10% of students aged 13-15 in Tamil Nadu had ever used tobacco. Significantly higher percentages of current tobacco users (one in three students) compared to never tobacco users thought smoking or chewing tobacco makes a boy or girl more attractive. About 3 in 4 current smokers expressed a wish to stop smoking and a similar proportion have already tried to quit the habit. About 80% of students considered using tobacco (smoking or chewing tobacco) to be harmful to their health. Only about half of the students reported that they have been taught in school the health effects of tobacco use during the year preceding the survey. Exposure to environmental tobacco smoke and pro-tobacco advertisements is high. CONCLUSIONS: The tobacco prevalence among girls is alarming. The results of the survey show the need to increase awareness about health hazards of tobacco use among students. Tobacco control programs focusing on youth are essential in order to reduce the burden of tobacco related diseases in India. Repeat surveys would help in monitoring the tobacco epidemic in the school and to evaluate the efficacy of state level tobacco control programs.

Grand challenges in global health and the practical prevention program? Asian focus on cancer prevention in females of the developing world.

In response to the request for 'Breakthrough Questions' for 'Grand Challenges in Global Health' recently published in Nature, the Asian Pacific Organization for Cancer Prevention should focus its attention on what projects are of the highest priority for integration with its Practical Prevention Program (PPP). The most common female cancers in most of the countries of Asia are carcinoma of the breast, followed by the uterine cervix. While the incidences of breast adenocarcinomas are still generally lower than in the Western world they are rapidly increasing, and squamous cell carcinomas of the cervix are a major problem. Clearly there are many areas which would reward research. One factor which appears of major relevance in the mammary gland case is the diet, and particularly the phytoestrogens included in 'tofu', along with physical exercise. The age at which these could be operating needs to be elucidated, with reference to timing of menarche and menopause, and also breast mammographic density, another predictor of likelihood of neoplasia. In the cervix, the predominant influence is well established to be persistent infection with a high risk 'oncogenic' type of human papilloma virus (HPV). Vaccines therefore hold much promise, but a better understanding of the mechanisms underlying spontaneous clearance of both infection and cervical intraepithelial neoplasia (CIN) of different grades is also essential for optimal intervention. The roles of smoking and antioxidant intake in particular deserve emphasis. In Asia, with the considerable variation evident in both breast and cervical cancer incidence rates, as well as in cultural and other environmental factors, we are in a very favourable position to meet two specific challenges: 1). elucidation of how diet in adolescence determines susceptibility to neoplasia of the mammary glands; and 2). determination of what governs persistence of HPV infection. Realisation of these pivotal research aims, with especial emphasis on the context of the PPP, is our shared goal.

An Independent Survey to Assess Completeness of Registration: Population Based Cancer Registry, Chennai, India.

Cancer registration in the population based cancer registry (PBCR), Chennai, India, is carried out by active methods. It undertakes re-screening of cases in government hospitals and Cancer Institute (WIA), trace back death certificate notifications and collect information on all the deaths, irrespective of the stated cause on the death certificate, occurring in the registry area routinely to reduce the under-registration of incident cancer cases and associated mortality. The completeness of registration during 1982-95 was assessed by conducting an independent survey in randomly selected areas in Chennai. The total number of households covered in the survey was 7737 and were collected which constituted 1% of the Chennai city population. The response rate to the survey was 96%. A total of 42,502 incident cancer cases were registered in Chennai PBCR during 1982-95. The total number of cancer cases that were already registered in PBCR from the survey area during 1982-95 was 208. Out of 208 cases, 91 (44%) were identified in the survey; the families of the remaining 117 had migrated out of the surveyed area. Two new cancer cases hitherto unregistered in the PBCR during 1982-95 were identified from the survey. Based on the survey, it is estimated that the completeness of cancer registration in Chennai PBCR is 96%, which is comparable to those of other registries in the world.

A survival study of cervical cancer in Chennai, India.

A total of 4304 cervical cancer cases registered during 1982-89 in Chennai registry, India, were analyzed. Relative survival at 1, 3 and 5 years were 90%, 72% and 60% respectively. Age at diagnosis and extent of disease emerged as statistically significant prognostic factors (p<0.001). Five-fold higher risk of death was seen among those above 64 years vs. <45 years and those with distant metastasis vs. localized disease at diagnosis. Cancer control programs focusing on health education would motivate women to attend hospital at an early stage of disease for better survival.

Epidemiology of cancer of the cervix: global and national perspective.

Cancer of the uterine cervix is one of the leading causes of cancer death among women worldwide. The estimated new cancer cervix cases per year is 500,000 of which 79% occur in the developing countries. Cancer cervix occupies either the top rank or second among cancers in women in the developing countries, whereas in the affluent countries cancer cervix does not even find a place in the top 5 leading cancers in women. The truncated rate (TR) in the age group 35-64 years in Chennai, India, is even higher (99.1/100,000; 1982-95) than rate reported from Cali, Colombia (77.4/100,000, 1987-91). The cervical cancer burden in India alone is estimated as 100,000 in 2001 AD. The differential pattern of cervical cancer and the wide variation in incidence are possibly related to environmental differences. Aetiologic association and possible risk factors for cervical carcinoma have been extensively studied. The factors are: Sexual and reproductive factors, socio-economic factors (education and income), viruses e.g., herpes simplex virus (HSV), human papillomavirus (HPV), human immunodeficiency virus (HIV) in cervical carcinogenesis and other factors like smoking, diet, oral contraceptives, hormones, etc. The accumulated evidence suggests that cervical cancer is preventable and is highly suitable for primary prevention. Sexual hygiene, use of barrier contraceptives and ritual circumcision can undoubtedly reduce cervical cancer incidence. Education, cervical cancer screening of high risk groups and improvement in socio-economic status can reduce cervical cancer morbidity and mortality significantly.

New evidence of non seasonal factors in the menarche rhythm

The phylogenetic, ontogenetic and seasonal hypotheses on the annual periodicity of menarche were tested. Data from European, Asian (Caucasian, Mongolian and Caucaso-Mongolian people from the northern hemisphere) and Chilean (Caucaso-Amerindian from the southern hemisphere) populations were compared with data from Hungary (Caucaso-Mongolian Europeans from a northern temperature zone) and Madras, India (a complex ethnically originated people from a tropical northern area). Chileans were compared with those Caucaso-Mongolian people because Amerindians belong also to the Mongolian group. Hungarian girls showed peaks of menarche in the month of January (winter), June, July and August (summer), in contradiction with most European Caucasians who showed peaks only in winter months; and in agreement with Finns who showed both peaks. Indian girls had peaks in April, May and June (summer) and more extreme peaks and troughs than the Finnish girls (from a temperature arctic zone). These findings do not agree with the seasonal hypothesis, but they do with the phylogenetic hypothesis. Indian girls had a peak of menarche in the same month of birth and the arrangement of data according to the gestational-menarche coincidence showed a significant heterogeneity for the monthly peaks of menarche; thus, the ontogenetic hypothesis was also supported

Methodology for long term follow-up of cancer cases in a developing environment.

The utility of data collected on patients will be rendered insignificant without adequate follow-up information. Efficient methods should be used to follow cases in order to get vital status information in Hospital(HBCR) and Population Based Cancer Registries (PBCR). Based on our experience we have evolved methods to follow cancer cases and this has been discussed in this paper. Active follow up of cases has enhanced follow-up rate from 50% to more than 85% at HBCR and "death in period" from 19% to 41% during the period 1982 to 1991 in PBCR. Active follow-up is mandatory for the cases registered at HBCR. In addition to collecting data from VSD on cancer deaths, active follow-up is desirable to get maximum death information on cases registered at PBCR in a developing environment. Computerization of follow-up data is necessary in order to further improve the efficiency of the follow-up system.

An easy method of spirometry.

Recording of forced expiration from tidal inspiratory level-referred to as Forced Expiratory Capacity (FEC) is a simple and more convenient technique than the conventional forced vital capacity (FVC) manouvre. From FEC tracing, volume expelled in one second (FEC1) and its percentage (FEC1%) can be measured. Such spirometric recording obtained from tidal breathing to Residual Volume (RV) may be referred to as Spirometric Recording at low lung volume. Asthmatics as well as old subjects find this manouvre easier to perform than the conventional FVC technique. FEC recording becomes a simple, reliable and sensitive test for evaluation of early airway obstruction in asymptomatic smokers and therefore may be utilised in clinical and epidemiologic surveys.

Zinc counteracts experimentally-induced cirrhotic changes in rats.

In the present study, cirrhosis was induced in rats by administration of carbon tetra chloride for 8 weeks. In these animals ZnSo4 (equivalent to 100 and 200 micrograms of zinc) was administered orally and liver function tests and plasma zinc (Zn) estimations were carried out after 2 and 4 week intervals. The results revealed that Zn supplement counteracts cirrhotic changes in liver.

Inspiratory spirogram in emphysema.

Bronchodilator therapy on inspiratory indices has not been documented so far. Reduction in inspiratory airflow resistance following inhalation of bronchodilator giving the most consistent and significant changes in emphysematous patients has been demonstrated in the present study.

Correlation of blood groups with congenital disorders and gastro intestinal diseases.

Blood group studies were conducted in 330 patients suffering from gastro intestinal disorders and 180 patients with congenital malformations and compared with normal subjects. Statistical analysis has shown that (a) there is significant correlation between B group and thalassaemia, (b) congenital malformations show higher incidence in B and O groups. It would be pertinent to draw attention to the fact that B group was found to be significantly correlated to duodenal ulcer from the present study contrary to the early reports. In addition, these observations show that blood groups are linked with diseases.

Certain observations in electrocardiogram and enzyme variation in dogs, following scorpion venom injection.

The effect of scorpion venom of Buthus Tamulus species on blood pressure, ECG, enzyme and electrolytes were studied in dogs. Venom was given in doses of 2 and 4 mg/kg body weight. Hypotension and tachycardia were observed with low dose and bradycardia was significant with high dose. ST segment depression, T wave changes, shortening of PR interval were the important ECG changes apart from ventricular extrasystoles. With high dose, QRS amplitude was reduced and duration prolonged. QTC interval was also significantly prolonged. Significant increase in SGOT, SGPT and LDH levels were observed but no change in serum electolytes was seen.