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A Rh(I) complex supported by a fused π-conjugated imidazo[1,2-a][1,8]naphthyridine-based N-heterocyclic carbene ligand with a Dipp attachment on the imidazole nitrogen has been synthesized and structurally characterized. The title complex is found to be an excellent catalyst for accessing E-vinylsilanes. The scope of the chemoselective hydrosilylation is examined for a range of terminal alkynes with silanes Et3SiH and (EtO)3SiH.

Compounds containing Arsenic (As) have been contaminating the ground water not only in India, but also in other countries of the world. Millions of people are affected by various Arsenic-related diseases, such as skin diseases, cardiovascular diseases, neurological disorders, etc. Due to these reasons, extensive research is being carried for detection and removal of arsenic-containing compounds by various research groups. Numerous arsenic moieties, such as As(III) containing H3AsO3, H2AsO3−, HAsO32−; As(V) containing H3AsO4, H2AsO4−, HAsO42− as well as organoarsenic compounds are being actively studied in order to detect these from different aqueous sources. Several research groups are also investigating methods for removal of these ions and compounds using nanomaterials. Herein, we briefly recount the recent and diverse research activities, carried out by various researchers, in this important area in the past few years.

Indoor air quality of schools is a subject of great significance for the assessment of the effects of children exposure to air pollution. In order to characterize the indoor air quality, coarse and fine particulate matter (PM) levels, concentration of gaseous pollutants (CO2, SO2, NO2, O3) and major anions, elemental concentration, morphology and risk assessment were evaluated from the samples collected in different naturally ventilated schools in Pune, India. Mass concentration of both coarse and fine PM exceeded 5 times WHO standards, which clearly indicates the insufficient fresh air in school buildings of Pune in terms of PM. The average concentration of gaseous pollutants were within prescribed limits of NAAQS except CO2 which was higher in concentration than the limit set for confined spaces, thus showing the inadequate air exchange rates in the studied schools. The Ca showed significant dominance among the analyzed metals in both fraction of PM followed by Mg, Na and K. Cd showed higher bioavailability index among the carcinogenic metals leading to health hazards to exposed children. The cancer risk for Cr, Cd, Ni, and Pb in both sized PM were much higher than the acceptable limits of USEPA. Average anionic concentration followed the similar pattern for both sized fraction of PM and the trend was NO3− > SO42− > Cl− > F−. The morphological analysis revealed the presence of various shaped particles composed of various constituents of Si, C and Ca. Questionnaire survey and personnel interview showed the prevalence of cold, running nose, cough, fever and eye irritation among the studied school children exposed to the PM and gaseous species. The health problems such as cold, cough and fever were found to be the main cause of absenteeism of children.

This work investigates the absorption properties of soluble brown carbon (BrC), extracted in methanol and water, from ambient aerosol (PM10) samples, collected over an urban background site in Mumbai, India. The diurnal variability was investigated in samples collected in the morning (7–11 a.m.) and afternoon (12–4 p.m.) periods. Absorption properties of BrC (in the 300–600-nm wavelength range) were measured in filter extracts of water-soluble organic carbon (WSOC) and methanol-soluble organic carbon (MSOC). WSOC and MSOC accounted for on average 52% and 77%, respectively, of the measured OC, potentially indicating unextracted BrC and rendering these values the lower bound. Compared with afternoon samples, the morning samples of MSOC and WSOC had increased BrC concentrations and absorption coefficients (babs365; 40%–65%). The correlation between babs365 and EC, ns-K+, and NO3− in the morning samples indicated contributions from primary sources, including both biomass and vehicular sources. The decreased babs365 in the afternoon samples was partly explained by mixing layer dilution, accompanied by a reduction in the concentrations of primary aerosol constituents. Furthermore, in the afternoon samples, 1HNMR spectroscopy revealed the presence of more oxidized functional groups and significantly higher OC/EC and WSOC/OC ratios, indicating the greater aging of afternoon aerosol. The MAC365 (m2gC−1) for both WSOC and MSOC extracts decreased significantly by 20%–34% in the afternoon samples compared with the morning samples, indicating degradation in the absorption properties of the particles and potentially a change in the constituent BrC chromophores.

Indoor concentrations of fine (PM2.5: aerodynamic diameter ≤ 2.5) and inhalable (PM10: aerodynamic diameter ≤ 10 μm) particles and its associated toxic metals are of concern now-a-days due to its effects on human health and environment. PM10 and PM2.5 samples were collected from indoor microenvironments on glass fiber and PTFE filter paper using low volume air sampler in Pune. The average concentration of PM2.5 and PM10 were 89.7 ± 43.2 μg m−3 and 138.2 ± 68.2 μg m−3 at urban site while it was 197.5 ± 84.3 and 287 ± 92 μg m−3 at rural site. Trace metals such as Cd, Co, Cr, Cu, Fe, Mn, Pb, Sb and Zn in particulate matter were estimated by ICP–AES. Concentrations of crustal metals were found to be higher than the carcinogenic metals in both the microenvironments. On the contrary the soluble and bio-availability fraction of carcinogenic metals were found higher thus it may cause the higher risk to human health. Therefore, cancer risk assessment of carcinogenic metals; Cr, Ni and Cd was calculated. Among the carcinogenic metals, Ni showed highest cancer risk in indoor PM. The higher cancer risk assessment of Ni has been supported by In-silico study which suggested that Ni actively formed co-ordination complex with histone proteins (i.e. H3–Ni/H4–Ni) by maintaining strong hydrogen bonding interactions with Asp and Glu residues of nucleosomal proteins. Present In-silico study of Ni-histone complexes will help to emphasize the possible role of Asp and Glu residues in DNA methylation, deacetylation and ubiquitinations of nucleosomal proteins. Hence, this study could pave the way to understand the structural consequence of Ni in nucleosomal proteins and its impact on epigenetic changes which ultimately cause lung and nasal cancer.

Objectives The purpose of the present study was to comparatively evaluate the effect of flowable composite resin liner and resin modified glass ionomer liner on gingival marginal adaptation of class II cavities restored using three bonding agents (Single Bond 3M ESPE, One Coat Self Etching Bond Coltene Whaledent; Adper Easy Bond Self-Etch Adhesive 3M ESPE) and respective composite resins, under cyclic loading. The marginal adaptation was evaluated in terms of ‘continuous margin’ (CM) at the gingival margin. Materials and methods Ninety class II cavities with margins extending 1 mm below the cement–enamel junction were prepared in extracted mandibular third molars. The samples were divided into three groups: no liner placement; 0.5–1 mm thick flowable resin liner placement (Filtek Z350 XT flowable resin) on gingival floor and; light cure glass ionomer (Ketac N100) liner. The groups were further subdivided into three sub-groups on the basis of the bonding agents used. Cavities were restored with composite resins (Z350 for Single Bond and Adper Easy Bond; and Synergy D6 Universal, for One Coat Self Etching Bond) in 2 mm increments and the samples were mechanically loaded (60 N, 1,50,000 cycles). Marginal adaptation was evaluated using a low vacuum scanning electron microscope. Statistical analysis was done with two way ANOVA with Holm–Sidak's correction for multiple comparisons. Results Placement of flowable composite liner significantly improved the CM values of Single Bond (78 ± 11%) and One Coat Self Etching Bond (77 ± 9%) compared with no liner group, but the values of CM of Adper Easy Bond were not improved (61 ± 12%). Placement of glass ionomer liner significantly improved the values of CM in all the sub-groups (78 ± 9%, 72 ± 10% and 77 ± 10% for Single Bond, One Coat Self Etching Bond & Adper Easy Bond respectively) compared with no liner group. Conclusions Placement of liners improved the values of ‘continuous margin’ in the gingival floor of the proximal cavities restored with composite resins using different bonding agent. Clinical relevance Placement of flowable composite liner or glass ionomer liner will improve the marginal integrity of composite restorations using etch-and-rinse and two bottle-two step self etch adhesives. To improve the marginal integrity of a single bottle adhesive, glass ionomer liner should be applied.

To identify new structure-function correlations in the γ domain of streptokinase, mutants were generated by error-prone random mutagenesis of the γ domain and its adjoining region in the β domain followed by functional screening specifically for substrate plasminogen activation. Single-site mutants derived from various multipoint mutation clusters identified the importance of discrete residues in the γ domain that are important for substrate processing. Among the various residues, aspartate at position 328 was identified as critical for substrate human plasminogen activation through extensive mutagenesis of its side chain, namely D328R, D328H, D328N, and D328A. Other mutants found to be important in substrate plasminogen activation were, namely, R319H, N339S, K334A, K334E, and L335Q. When examined for their 1:1 interaction with human plasmin, these mutants were found to retain the native-like high affinity for plasmin and also to generate amidolytic activity with partner plasminogen in a manner similar to wild type streptokinase. Moreover, cofactor activities of the mutants precomplexed with plasmin against microplasminogen as the substrate as well as in silico modeling studies suggested that the region 315–340 of the γ domain interacts with the serine protease domain of the macromolecular substrate. Overall, our results identify the presence of a substrate specific exosite in the γ domain of streptokinase.

The bacterial protein streptokinase (SK) contains three independently folded domains (alpha, beta and gamma), interconnected by two flexible linkers with noticeable sequence homology. To investigate their primary structure requirements, the linkers were swapped amongst themselves i.e. linker 1 (between alpha and beta domains) was swapped with linker 2 (between beta and gamma domains) and vice versa. The resultant construct exhibited very low activity essentially due to an enhanced proteolytic susceptibility. However, a SK mutant with two linker 1 sequences, which was proteolytically as stable as WT-rSK retained about 10% of the plasminogen activator activity of rSK When the native sequence of each linker was substituted with 9 consecutive glycine sequences, in case of the linker 1 substitution mutant substantial activity was seen to survive, whereas the linker 2 mutant lost nearly all its activity. The optimal length of linkers was then studied through deletion mutagenesis experiments, which showed that deletion beyond three residues in either of the linkers resulted in virtually complete loss of activator activity. The effect of length of the linkers was then also examined by insertion of extraneous pentapeptide sequences having a propensity for adopting either an extended conformation or a relatively rigid conformation. The insertion of poly-Pro sequences into native linker 2 sequence caused up to 10-fold reduction in activity, whereas its effect in linker 1 was relatively minor. Interestingly, most of the linker mutants could form stable 1:1 complexes with human plasminogen. Taken together, these observations suggest that (i) the functioning of the inter-domain linkers of SK requires a critical minimal length, (ii) linker 1 is relatively more tolerant to insertions and sequence alterations, and appears to function primarily as a covalent connector between the alpha and beta domains, and (iii) the native linker 2 sequence is virtually indispensable for the activity of SK probably because of structural and/or flexibility requirements in SK action during catalysis.

The communication describes standardization of an efficient in vitro propagation and hardening procedure for obtaining plantlets from field grown culms of Bambusa tulda. Administration for 10 min of 0.05 and 0.1% mercuric chloride to explants collected in winter and summer seasons, respectively facilitated optimum culture establishment and bud break. 0.1–0.2% mercuric chloride in rainy season enhanced aseptic culture establishment but inhibited bud break due to toxicity to explants. MS liquid medium enriched with 100 μM glutamine, 0.1 μM indole-3-acetic acid and 12 μM 6-benzylaminopurine supported maximum in vitro shoot multiplication rate of two-fold. The proliferated shoots were successfully rooted on MS liquid medium supplemented with 40 μM coumarin resulting in a maximum of 98% rooting. The procedure requires 45 days cycle for the in vitro clonal propagation (15 days for shoot multiplication and 30 days for root induction) and 80 days for acclimatized plantlet production.

The salts of the linkage isomers of thiocyanatopentammineruthenium(III) [Ru(NH 3 ) 5 ( N CS)] 2+ , [Ru(NH 3 ) 5 ( S CN)] 2+ and dithiocyanatotetrammineruthenium(III) [Ru(NH 3 ) 4 (NCS) 2 ] + along with those of tetrathiocyanatodiammineruthenate(III) [Ru(NH 3 ) 2 (SCN) 4 ] − have been synthesized. The insoluble polymeric complex [Ru(NH 3 ) 2 (SCN) 2 ] n has also been prepared. The compounds have been characterized by chemical analyses, spectral (IR, UV and visible), magnetic susceptibility, conductivity, cyclic voltammetry and chromatography studies.

The thiocyanato bridged mixed-valence ruthenium dinuclear species [{Ru(NH3)5}2SCN]4+ has been prepared and characterized. A solvent independent, low intensity intervalence transfer band was observed in the near IR absorption spectrum suggesting a delocalized limit in the [Ru(II)-SCN-Ru(III)] unit.