Scalable Multipollutant Exposure Assessment Using Routine Mobile Monitoring Platforms.

INTRODUCTION: The absence of spatially resolved air pollution measurements remains a major gap in health studies of air pollution, especially in disadvantaged communities in the United States and lower-income countries. Many urban air pollutants vary over short spatial scales, owing to unevenly distributed emissions sources, rapid dilution away from sources, and physicochemical transformations. Primary air pollutants from traffic have especially sharp spatial gradients, which lead to disparate effects on human health for populations who live near air pollution sources, with important consequences for environmental justice. Conventional fixed-site pollution monitoring methods lack the spatial resolution needed to characterize these heterogeneous human exposures and localized pollution hotspots. In this study, we assessed the potential for repeated mobile air quality measurements to provide a scalable approach to developing high-resolution pollution exposure estimates. We assessed the utility and validity of mobile monitoring as an exposure assessment technique, compared the insights from this measurement approach against other widely accepted methods, and investigated the potential for mobile monitoring to be scaled up in the United States and low- and middle-income countries. METHODS: Our study had five key analysis modules (M1- M5). The core approach of the study revolved around repeated mobile monitoring to develop time-stable estimates of central-tendency air pollution exposures at high spatial resolution. All mobile monitoring campaigns in California were completed prior to beginning this study. In analysis M1, we conducted an intensive summerlong sampling campaign in West Oakland, California. In M2, we explored the dynamics of ultrafine particles (UFPs) in the San Francisco Bay Area. In analysis M3, we scaled up our multipollutant mobile monitoring approach to 13 different neighborhoods with ~450,000 inhabitants to evaluate within- and between-neighborhood heterogeneity. In M4, we evaluated the coupling of mobile monitoring with land use regression models to estimate intraurban variation. Finally, in M5, we reproduced our mobile monitoring approach in a pilot study in Bangalore, India. RESULTS: For M1, we found a moderate-to-high concordance in the time-averaged spatial patterns between mobile and fixed-site observations of black carbon (BC) in West Oakland. The dense fixed-site monitor network added substantial insight about spatial patterns and local hotspots. For M2, a seasonal divergence in the relationship between UFPs and other traffic-related air pollutants was evident from both approaches. In M3, we found distinct spatial distribution of exposures across the Bay Area for primary and secondary air pollutants. We found substantially unequal exposures by race and ethnicity, mostly driven by between-neighborhood concentration differences. In M4, we demonstrated that empirical modeling via land use regression could dramatically reduce the data requirements for building high-resolution air quality maps. In M5, we developed exposure maps of BC and UFPs in a Bangalore neighborhood and demonstrated that the measurement technique worked successfully. CONCLUSIONS: We demonstrated that mobile monitoring can produce insights about air pollution exposure that are externally validated against multiple other analysis approaches, while adding complementary information about spatial patterns and exposure heterogeneity and inequity that is not readily obtained with other methods.

New cytochalasin from Rosellinia sanctae-cruciana, an endophytic fungus of Albizia lebbeck.

AIM: To explore the potential of Rosellinia sanctae-cruciana an endophytic fungus associated with Albizia lebbeck for pharmaceutically important cytotoxic compounds. METHODS AND RESULTS: One novel cytochalasin, named jammosporin A (1) and four known analogues (2-5) were isolated from the culture of the endophytic fungus R. sanctae-cruciana, harboured from the leaves of the medicinal plant A. lebbeck. Their structures were elucidated by extensive spectroscopic analyses including one-dimensional and two-dimensional nuclear magnetic resonance data along with MS data and by comparison with literature reports. In preliminary screening the ethyl acetate extract of the fungal culture was tested for cytotoxic activity against a panel of four cancer cell lines (MOLT-4, A549, MIA PaCa-2 and MDA-MB-231), and found to be active against MOLT-4 with an IC50 value of 10 µg ml-1 . Owing to the remarkable cytotoxic activity of the extract the isolated compounds (1-5) were evaluated for their cytototoxicity against the MOLT-4 cell line by MTT assay. Interestingly, compounds 1-2, 4 and 5 showed considerable cytotoxic potential against the human leukaemia cancer cell line (MOLT-4) with IC50 values of 20·0, 10·0, 8·0 and 6·0 µmol l-1 , respectively, while compound 3 showed an IC50 value of 25 µmol l-1 . This is the first report of the existence of this class of secondary metabolites in R. sanctae-cruciana fungus. CONCLUSION: This study discovered a novel compound, named jammosporin A, isolated for the first time from R. sanctae-cruciana, an endophytic fungus of A. lebbeck with anticancer activity against the MOLT-4 cell line. SIGNIFICANCE AND IMPACT OF THE STUDY: Rosellinia sanctae-cruciana represents an interesting source of a new compound with bioactive potential as a therapeutic agent against a human leukaemia cancer cell line (MOLT-4).

Carbon nanotube/nanofiber embedded nanoporous anodized aluminium oxide surface and its tribological properties.

Nanoporous alumina has been prepared by anodization of pure aluminium using phosphoric acid electrolyte. Carbon nanotubes/nanofibres (CNTs/CNFs) are grown within the pores by chemical vapour deposition technique, using acetylene gas as carbon precursor. Such synthesis of nanostructured carbonaceous materials within the nanoporous oxide template has high potential for many applications (e.g., electronics, magnetic, etc.) in nanotechnology. Possibility of using such material combination for engineering systems where abrasion resistance coupled with self-lubrication (at comparatively higher loads) are the key requirements, has been explored through the present work. Pore structure has been characterized by SEM/FE-SEM in this study and CNTs/CNFs have been examined by TEM, FE-SEM and Raman spectroscopy. While the pore diameters are found to lie in the range of 180-220 nm, the CNTs/CNFs diameter are observed to be in the range of 50 to 220 nm. The CNTs/CNFs growing from bottom of the pores are found to replicate the pore diameter, while those grown above the surface are varying significantly in diameter and probably matching the diameter of the catalyst, which remains adsorbed on the top surface and inner walls of the pores. On comparing friction and wear properties of both materials (viz. anodized alumina and CNTs/CNFs embedded anodized alumina) as determined by pin-on-disc machine using hardened steel disc as counterface, it is found that wear rate and coefficient of friction of CNTs embedded composite surface is significantly lower which is attributed to formation of transfer layer of hard wear resistant alumina mechanically mixed with graphitic CNTs/CNFs.

Band-gap engineering in two-dimensional semiconductor-dielectric photonic crystals.

This paper reports the multiple band gaps in the two-dimensional semiconductor-dielectric photonic crystals of several compositions: semiconductor cylinders in the dielectric background. We consider both square lattice and hexagonal lattice arrangements and compute extensive band structures using a plane-wave method within the framework of an efficient standard eigenvalue problem for both E and H polarizations. The whole range of filling fraction has been explored to claim the existence of the lowest (the so-called acoustic) band gap and multiple higher-energy band gaps within the first 30 to 40 bands for various compositions. Such semiconductor-dielectric photonic crystals which are shown to possess huge lowest band gaps below a threshold frequency (the plasma frequency omega(p) ) have an advantage over the dielectric photonic crystals in the emerging technology based on the photonic crystals.

Polymerase chain reaction vs. conventional diagnosis in fine needle aspirates of tuberculous lymph nodes.

OBJECTIVE: To compare four conventional methods of diagnosing tuberculous lymphadenophathy (TL)--namely fine needle aspiration cytology (FNAC), Zeihl-Neelsen staining of smears for acid-fast bacilli (AFB), culture for Mycobacterium tuberculosis (MTB) and lymph node biopsies--with the polymerase chain reaction (PCR) in order to assess the practicability and advantage of its use in routine diagnosis in a developing country. STUDY DESIGN: Fine needle aspirates from 142 consecutive patients presenting with lymphadenopathy (mainly cervical) without any known systemic involvement underwent cytomorphologic diagnosis, AFB smears, culture for MTB, confirmatory biopsy and PCR for MTB. The aspirates from cases other than TL served as controls for PCR. RESULTS: Correct diagnosis of tuberculosis could be made in 94.87% of cases by a combination of the four methods. PCR was done in 52 cases, 39 confirmed TL and 13 controls. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value of PCR were 94.44%, 38.23%, 44.73% and 92.85%, respectively, when culture alone was considered the gold standard. However, specificity (38.23-92.30%) and PPV (44.73-97.36%) of PCR increased remarkably when response to treatment was taken as the final arbiter. CONCLUSION: The four conventional tests were found to be the methods of choice for the diagnosis of TL in developing countries. PCR should be reserved for problem cases.

Serum beta 2-microglobulin in lymphoproliferative and myeloproliferative diseases.

The serum levels of beta 2-microglobulin (beta 2m), which is the light chain moiety of the HLA (-A, -B, -C) antigens, are increased in many of the haematological malignancies. In the lymphoproliferative disorders there is generally an association between serum beta 2m and estimates of tumour load. This relationship is especially close in myelomatosis, where serum beta 2m is a powerful prognostic indicator and can be used in stratification and monitoring. Increases in serum beta 2m are also frequent in the myeloproliferative disorders, notably in myelofibrosis, and in the myelodysplastic syndromes; particularly high levels are seen in chronic myelomonocytic leukaemia. In addition to suggested cellular sources of the beta 2m in these diseases--malignant lymphoid cells and cells of the monocyte-macrophage series--the possibility that T lymphocyte sub-sets could be important contributors to the increased beta 2m production is discussed.

The problem of paralytic poliomyelitis in the urban and rural population around Lucknow, India.

A house to house survey was done from October 1972 to March 1974, covering 528952 individuals of urban population at Lucknow and 50,156 individuals of rural population of Unnao district, to find out the incidence of polio-like paralysis in our population. Among 12874 urban children up to 8 years old 8.2/1000 had polio-like paralysis while 4.6/1000 children of the rural population of 13554 children were affected. The incidence was significantly higher in the urban population. In the preschool age group almost 1 out of every 100 children was affected. A higher number of children were affected during 1968-9 and 1971-2, though it did not reach epidemic proportion. The findings show that paralytic polio is a serious problem in our country where poliomyelitis is endemic: this is contrary to the views generally held so far.