Photoluminescence Quenching Upon Growth of Metal Nanoparticles: Quantum-Mechanical Views.

In dictating the optical processes in metal nanoparticles, for instance, quantum nature of free electrons is significantly dominant and plays very crucial roles at the level of nanoscale dimensions of materials. As consequences of the quantum-confinement effects on the conduction electrons, surface-plasmon resonance induced optical absorption and light emission properties of metal nanoparticles are found to be strongly dependent on physical dimensions of the nanomaterials. In addition, surface-confined acoustic vibration (phonon) modes have been experimentally observed to depend on the sizes of the metal nanoparticles. Also, interestingly, tuning of the surface-plasmon resonance condition is found to enhance the intensity of the acoustic Raman modes in metal nanoparticles. The study highlights the role of plasmon-phonon coupling in Co metal nanoparticles embedded in a silica-glass. In the research field of nanosciences and nanotechnologies, extraordinary behaviour and properties of nanoscale matters are investigated. In this context, interesting studies have been discussed in this review article to elaborate optical, chemical and photoluminescence properties of nanoscale Ag metal particles. Subtle detection of optical phenomena associated with the excited many-body electronic processes in the metal nanoparticles, for example, are very interesting but definitely challenging. Here we make an attempt to find out how the thermal growth of Ag metal nanoparticles in a glass matrix snuffs out the light emission from the samples? Quantum mechanical interpretations of the underlying processes about the quenching of photoluminescence phenomena with the growth of the metal nanoparticles will help to fine tune the optical properties of plasmonic systems as well as to harness potential applications of the nanomaterials.

Respiratory response to tobacco dust exposure among biddi binders: A follow up and bronchodilator study.

INTORDUCTION: The tobacco dusts get air borne during biddi making and it is inhaled by the biddi binders, which affects their health. RESULTS: In a follow-up study, 86 biddi binders (male, 41; female, 45) were studied at a gap of 2 years. A high respiratory morbidity was observed among males than females both in the initial and follow-up study. The main complaints such as cough, sputum, and breathlessness showed high prevalence rates in the follow-up study. The high prevalence rates of weakness, giddiness, chronic diarrhea, and dyspepsia were noted in most of the cases the above complaints showed higher rates in the follow-up study. Pulmonary function test (PFT) values in the follow-up study of male and female biddi binders showed lowered compared with the initial study of same gender. In male and female biddi binders, the lung volumes SVC, FVC, FEV1, and the flow rates FEF0.2-1.2 l, FEF25%-75%, FEF75%-85% were significantly lowered in the follow-up study compared with the initial study. Age-related decrement in PFT was observed in both the studies. In nonsmokers, smokers, and ex-smokers, the PFT values are lowered. The current smokers have the lowest values in both the studies. With the administration of the bronchodilator aerosol (salbutamol) in 63 biddi binders (male, 27; female, 36), the effect of bronchodilator aerosol on the PFT parameters showed significant changes as all PFT parameters showed positive bronchodilatation. CONCLUSION: The pattern of bronchodilator response on PFT values of the biddi binders suggests that the obstructions in the airways are reversible in nature.

Parkinson's disease cybrids, differentiated or undifferentiated, maintain morphological and biochemical phenotypes different from those of control cybrids.

SH-SY5Y, control, and Parkinson's disease (PD) cybrids prepared from an Indian population were differentiated using retinoic acid (RA) for understanding their dopaminergic characteristics and neuritogenesis. Undifferentiated control and PD cybrids exhibited higher levels of TH mRNA, but lower c-RET expression, short neurites, low neuritic density, and low proportion of cells with neurites compared with the undifferentiated parent cell line, SH-SY5Y. The expression levels of DAT and Ptx3 were similar to SH-SY5Y. PD cybrids showed poor viability and lower differentiating potency than SH-SY5Y or control cybrids. RA treatment for 6 days elevated c-RET expression and corrected the neuritic morphology of the control, but not of PD cybrids. Cell viability was found to be reduced in differentiated control and PD cybrids. TH expression level was significantly elevated in SH-SY5Y following RA treatment, but not in both the cybrids. In differentiated control and PD cybrids, the TH immunofluorescence intensity was significantly lower compared with SH-SY5Y cells. MitoTracker Green fluorescence intensity of the mitochondria was higher in differentiated PD cybrids. Dopamine released into the medium was unaffected in the differentiated SH-SY5Y or in the control cybrids but was significantly elevated in PD cybrids. These results suggest that PD cybrids, differentiated or undifferentiated, maintained morphological and biochemical phenotypes significantly different from those of the control cybrids, or the differentiated SH-SY5Y cells, and therefore could be an ideal cellular model of the disease for pharmacological screening of drugs and for investigation of the pathophysiology of PD.

Socio-economic status of workers of building construction industry.

BACKGROUND: Informal/unorganised sector covers 92% of the total work force in India. About 50% of the construction industrial workers belonged to informal/unorganised sector. MATERIAL AND METHODS: The present study was undertaken to know the socio-economic status of construction worker and availing of the social security measures by this working group. RESULTS AND CONCLUSION: The study covered 150 subjects with an average age of 32 years and mean duration of work was nine years. They were poorly paid with an average income of Rs. 4956/-per month. Though the literacy rate was high (79%) yet most of them were addicted to different habits like drinking alcohol, smoking bidi, tobacco chewing etc., Abusing the family members were noted in (30%) of the cases. Their regular intake of food, usually inadequate in quantity and was mainly consisted of rice, pulses, vegetables. Though most of the subjects (73%) were living in kacha houses yet the latrine facilities were available to 62% of total covered houses. Majority of them were unaware of the different social security schemes/measures. The details have been discussed here.

Efficacy of zolmitriptan nasal spray in management of acute migraine.

BACKGROUND: Migraine is a very common neurological disorder. Treatment of acute attack of migraine is difficult. Non specific treatment includes various analgesic preparations having incomplete pain relieving effect with lot of side effects. Specific treatment for acute migraine attacks includes triptans and ergotamines. PURPOSE: The purpose of this study was to examine the efficacy of zolmitriptan nasal spray in management of acute migraine. METHODS: In the present investigation zolmitriptan nasal spray is administered to patients having acute migraine attack. Visual analogue score was done every hour for headache and other symptoms. RESULTS: Headache, photophobia, phonophobia, nausea and disability are relieved completely in 60%, 60%, 50%, 80%, 75% cases respectively and partially in 25%, 20%, 35%, 15%, 15% respectively. Mild side effects which occurred after treatment are well tolerated by 90% of patients. CONCLUSION: Zolmitriptan nasal spray not only reduces headache in 85% but it also reduces other symptoms of migraine like photophobia, phonophobia, nausea and disabilities.

Young girl with multiple intracranial hydatid cyst.

8 years young girl presented with uncontrolled seizures in obtunded and bedridden state. MRI brain showed multiple extra-axial coalescent cystic lesions in bilateral frontotemporo parietal regions - diagnosed as multiple hydatid cyst. We used irrigation saline during surgery and a total 35 cysts were removed intact, one by one separately and histologically confirmed as hydatid cyst. Postoperatively, patient showed marked neurological improvement and was seizure free.

A review on the occupational health and social security of unorganized workers in the construction industry.

Construction is one of the important industries employing a large number of people on its workforce. A wide range of activities are involved in it. Due to the advent of industrialization and recent developments, this industry is taking a pivotal role for construction of buildings, roads, bridges, and so forth. The workers engaged in this industry are victims of different occupational disorders and psychosocial stresses. In India, they belong to the organized and unorganized sectors. However, data in respect to occupational health and psychosocial stress are scanty in our country. It is true that a sizable number of the workforce is from the unorganized sectors - the working hours are more than the stipulated hours of work - the work place is not proper - the working conditions are non-congenial in most of the cases and involve risk factors. Their wages are also not adequate, making it difficult for them to run their families. The hazards include handling of different materials required for construction, and exposure to harsh environmental conditions like sun, rain, and so on. On account of this, in adverse conditions, it results in accidents and adverse health conditions cause psychosocial strain and the like. They are victims of headache, backache, joint pains, skin diseases, lung disorders like silicosis, other muscular skeletal disorders, and so on. The repetitive nature of the work causes boredom and the disproportionate earning compared to the requirements puts them under psychological stress and strain and other abnormal behavioral disorders. The Government of India has realized the importance of this industry and has promulgated an Act in 1996. The state government are being asked to adhere to this, although only a few states have partially enforced it. In this article, attempts have been made to review some of the important available articles for giving a broad idea of the problem and for furtherance of research in this field.

Albuminuria and neuropathy in newly detected diabetics: profile and correlation.

Neuropathy and nephropathy are two most common chronic complications of diabetes mellitus. Albuminuria and neuropathy has been found to be associated in patients with long standing diabetes. In the present study, the profiles of proteinuria and neuropathy have been studied in newly diagnosed cases of type 2 diabetes mellitus and attempt has been made to determine any relationship between the two. We studied 100 newly diagnosed ceases of type 2 diabetes mellitus and presence and type of neuropathy was assessed clinically and electrophysiologically. Albuminuria was detected by morning spot sample for albumin to creatinine ratio estimation. Results were analysed using appropriate statistical methods. It was found that 21 patients (21%) had proteinuria and 31 (31%) had neuropathy. Both were present in 16% patients and absent in 64% cases. The overall prevalence of neuropathy and proteinuria among study subjects was 36%. Isolated peripheral neuropathy was found in 9% patients, isolated autonomic neuropathy was found in 7% patients, and both were present in 15% cases. Proteinuria was mostly micro-albuminuria (90.5%). Occurrence of albuminuria and neuropathy has been found to be significantly associated with increasing age. Concurrence of diabetic neuropathy and albuminuria has been found to be significantly associated. The present study reveals that presence of neuropathy as well as nephropathy is common in newly diagnosed cases of type 2 diabetes mellitus. Both these complications have been significantly associated with increasing age indicating the possibility of a longer duration of undetected diabetes among them. Concurrence of neuropathy and nephropathy found in this study suggests that microvascular complications go hand in hand.

Respiratory effect related to exposure of different concentrations of arsenic in drinking water in West Bengal, India.

Arsenic toxicity due to drinking of arsenic contaminated water has been one of the worst environmental health hazards. High levels of arsenic have been reported in different natural water sources from West Bengal for more than two decades. Groundwater contamination by arsenic and its adverse effects on the health of a big population in nine districts of West Bengal have been reported. The problems found were mainly related to skin and respiratory, digestive, cardiovascular and nervous systems. The respiratory effects are largely confined to those who had the skin lesion. The present study was undertaken to evaluate the respiratory effects of exposure to different levels of arsenic in drinking water. The water samples were collected from different tube wells and wells in the study area. Analysis of arsenic was done by Atomic Absorption Spectrophotometer with hydride generation system. Based on the consumption of arsenic concentrations in drinking water the populations were divided into three categories, i.e., <=50 microg/L, >50 - <= 150 microg/L and >150 microg/L. Standard techniques of medical examination were applied to elicit signs and recorded in the pre-designed proforma. A written consent was taken from each subject for their voluntary participation in the study. 112 subjects were investigated. The respiratory effect was evaluated by measuring the pulmonary function test (PFT). Vital Capacity (VC) and Forced Vital Capacity (FVC) were measured by Spirovit-SP-10 (Schiller Health Care Pvt Ltd., Switzerland) and Peak Expiratory Flow Rate by Wrights Peak Flow Meter (Clement and Clarke, UK). The PFT values showed gradual decrement among the males following skin pigmentation, keratosis and arsenicosis. The respiratory function impairment among the male subjects found as restrictive type (26.41%), obstructive type (3.77%) and combined type (7.54%), whereas in females only the restrictive type of impairment (10.16%) was found. Restrictive type of impairments among the subjects increased as the concentration of arsenic in drinking water increased, in males 15.78%, 29.41% and 35.29% and in females 4.54%, 5.00% and 23.52% respectively. The pathophysiologic mechanism, by which ingested arsenic leads to impairments of lung function and increased respiratory symptoms, is yet to be understood and needs further investigation.

Subcortical white matter abnormalities related to drug resistance in Wilson disease.

Wilson disease (WD) produces typical lesions in the brain, which can aid in diagnosis and therapy. The authors present a drug-resistant WD case with atypical cerebral lesions with marked involvement of white matter as visualized on MRI scans. The diagnosis was confirmed by identification of mutations in the ATP7B gene. The case demonstrates an uncommon pathology-related cerebral copper accumulation and emphasizes the importance of genetic screening in the diagnosis of WD.

Height, weight and earnings among coalminers in India.

This paper analyses earning/wage differentials by height among coalmine workers in India. Our findings suggest that workers of above average height earn 9-17% more than their shorter counterparts and 6-13% more than average reference height. The results suggest that long-term investments in health human capital might ensure increase of labour productivity and thereby earnings, particularly in underdeveloped economies.

Comparison of pulmonary function test abnormalities between stone crushing dust exposed and nonexposed agricultural workers.

OBJECTIVES: The aim of this study is to examine the effects of stone crushing in West Bengal, India, by comparing pulmonary functions of stone crushing workers with those of nonexposed agricultural workers. METHODS: Two hundred seventy two stone crushing workers and 123 nonexposed workers were analyzed in terms of occupational and personal histories, radiological findings, and pulmonary function test (PFT) results including slow vital capacity (FVC), forced vital capacity (FVC) and peak expiratory flow rate (PEFR). Different lung volumes i.e. FEV(1), FEV(1%), and flow rates i.e. FEF(200-1200ml), FEF(25-75%) and FEF(75-85%), were analyzed with regard to sex, smoking habit, work status, age and work duration. RESULTS: Contrary to our expectations, the incidences of suspected (2.94%) and definite (1.84%) pneumoconioses were very low and the results of some PFT such as those for FVC and FEV(1%), in the exposed group were better than those in the nonexposed group, although a gradual decline the performance in PFT was observed with age and work duration. There was a higher prevalence of restrictive impairment among the exposed group and a higher prevalence of obstructive impairment in the nonexposed group. CONCLUSIONS: Some of the results were unexpected. Possible reasons for these include (i) undetectable concentrations of free silica in the stone dust in the work environment of the exposed workers and (ii) factors, such as climate, in the work environment of the nonexposed agricultural workers that could cause pulmonary impairment. Further protective measures should be undertaken to prevent pulmonary impairment in both groups of workers.

Molecular pathogenesis of Wilson disease: haplotype analysis, detection of prevalent mutations and genotype-phenotype correlation in Indian patients.

Wilson disease (WD) is an autosomal recessive disorder caused by defects in the copper-transporting P-type ATPase gene (ATP7B) resulting in the accumulation of copper in the liver and the brain. We identified prevalent mutations in the ATP7B of Indian WD patients and attempted to correlate those with the disease phenotype. Patients from 62 unrelated families and their first-degree relatives comprising 200 individuals were enrolled in this study. Three dinucleotide repeat markers flanking WD locus and a few intragenic SNPs were used to determine the genotypes and construct haplotypes of the patients. Seven recurring haplotypes accounting for 58% of the total mutant chromosomes were identified, and four underlying defects in the ATP7B representing 37% of WD chromosomes were detected. In addition, five other rare mutations were characterized. Thus a total of nine mutations including five novel changes were identified in the ATP7B of WD patients. Interestingly, homozygotes for different mutations that would be expected to produce similar defective proteins showed significant disparity in terms of organ involvement and severity of the disease. We also observed WD patients with neurological symptoms with little or no manifestation of hepatic pathogenesis. In one WD family, the proband and a sib had remarkably different phenotypes despite sharing the same pair of mutant chromosomes. These findings suggest a potential role for yet unidentified modifying loci for the observed phenotypic heterogeneity among the WD patients.

Optical absorption and photoluminescence spectroscopy of the growth of silver nanoparticles.

Results obtained from the optical absorption and photoluminescence (PL) spectroscopy experiments have shown the formation of excitons in the silver-exchanged glass samples. These findings are reported here for the first time. Further, we investigate the dramatic changes in the photoemission properties of the silver-exchanged glass samples as a function of postannealing temperature. Observed changes are thought to be due to the structural rearrangements of silver and oxygen bonding during the heat treatments of the glass matrix. In fact, photoelectron spectroscopy does reveal these chemical transformations of silver-exchanged soda glass samples caused by the thermal effects of annealing in a high vacuum atmosphere. An important correlation between temperature-induced changes of the PL intensity and thermal growth of the silver nanoparticles has been established in this Letter through precise spectroscopic studies.

Molecular analysis of GAA repeats and four linked bi-allelic markers in and around the frataxin gene in patients and normal populations from India.

Friedreich ataxia (FRDA), the most common type of ataxia worldwide, is an autosomal recessive disease. Homozygous expansion of GAA repeats in the first intron of the frataxin gene constitute the major type of mutation that causes the disease. The prevalence of FRDA in diverse ethnic populations of India has not been widely studied. We have studied the distribution of polymorphic GAA repeats in the frataxin gene among 6 clinically diagnosed patients and 160 ethnically matched normal individuals, to gather information on the prevalence of FRDA in the eastern part of India. Homozygous expansion in the range of 250-730 GAA repeats was detected among the patients. Among normal individuals, we observed a unimodal distribution of GAA repeats, consisting of 10 different alleles ranging from 7 to 16 GAA repeats, where the 9 repeat allele had maximal frequency. Only 5.9% of all chromosomes were found to harbour >12 GAA repeats. Haplotype analysis using closely linked four bi-allelic markers in and around the frataxin gene indicated that 66.7% of the expanded alleles harbour the ATCC haplotype that has been reported worldwide. This haplotype was present in 53.3% of the chromosomes with >12 GAA repeats, and accounted for only 3.8% of chromosomes with 7 to 12 GAA repeats. We found one novel haplotype, ACCT, among the expanded alleles as well as among normal individuals, though at low frequency; this haplotype may be characteristic of Indian populations.

Multiple brain haemorrhages in falciparum malaria.

A young male with multiple intracerebral haemorrhages with presence of P. falciparum in peripheral smear and normal coagulation profile without features of encephalopathy managed successfully with antimalarial has been reported. The rarity of the clinical presentation has been highlighted and its possible pathogenesis discussed.

Variation of CAG repeats and two intragenic polymorphisms at SCA3 locus among Machado-Joseph disease/SCA3 patients and diverse normal populations from eastern India.

OBJECTIVES: MJD1/SCA3 is the most common type of spinocerebellar ataxia (SCA) worldwide. To explain the low prevalence of the disease among SCA patients from eastern India, we analysed CAG repeats and two bi-allelic intragenic markers at SCA3 locus among 412 normal individuals and 10 patients. MATERIALS AND METHODS: For CAG repeat analysis, PCR amplified fragments were run on polyacrylamide gel, transferred to a membrane, probed with (CAG)10 and detected on an autoradiograph. Bi-allelic markers were analysed using allele specific PCR amplification. RESULTS: Large normal alleles (>33 CAG repeats) were 0.015 in pooled populations. All the patients had the common haplotype C-A as observed worldwide. Frequency of C-A haplotype among large normal alleles was 0.75. CONCLUSIONS: Observed low prevalence of SCA3 could be because of the low prevalence of large normal alleles that might act as the reservoir for the expanded alleles. SCA3 mutation in Indian populations had the same origin as found worldwide.