Gametogenesis,endosperm development,and embryogeny inMicrocarpaea muscosa (Scrophulariaceae,Gratioleae)

InMicrocarpaea muscosa gametogenesis, embryo sac development (Polygonum type), endosperm development (cellular), embryogeny (Onagrad type), and seed structure are described. The different modes of endosperm development withinGratioleae are compared.     

Radiobiology of ultrasoft X rays. III. Normal human fibroblasts and the significance of terminal track structure in cell inactivation

Ultrasoft characteristic X rays from carbon (0.28 keV) are severely attenuated as they pass through biological material, causing a nonuniform distribution of dose to cell nuclei. Complications of studying ultrasoft X rays can be minimized in this context by using cells with very thin cytoplasm and nuclei (e.g., less than the attenuation length of the X rays), and which exhibit a more nearly exponential dose response to cell killing, such as normal human fibroblasts compared with V79 cells. Using this cell system, we report the relative biological effectiveness (RBE) of A1-K and C-K X rays to be near unity. Previous studies of cell inactivation by characteristic carbon X rays gave RBEs of 3 to 4, supporting the idea that localized energy depositions from secondary electrons and primary track ends represent the principal mode of biological action for other low-LET radiations. In part, the reported high RBEs result from the use of mean dose to describe energy deposited within the cell nuclei by these poorly penetrating radiations. Implicit in the use of mean dose is that cellular damage varies linearly with dose within a critical target(s), an assumption that is of questionable validity for cells that exhibit pronounced curvilinear dose responses. The simplest interpretation of the present findings is that most energy depositions caused by track-end effects are not necessarily more damaging than the sparsely ionizing component.     

Amberlite IRA 900 versus calcium alginate in immobilization of a novel,engineered β-fructofuranosidase for short-chain fructooligosaccharide synthesis from sucrose

The immobilization of β-fructofuranosidase for short-chain fructooligosaccharide (scFOS) synthesis holds the potential for a more efficient use of the biocatalyst. However, the choice of carrier and immobilization technique is a key to achieving that efficiency. In this study, calcium alginate (CA), Amberlite IRA 900 (AI900) and Dowex Marathon MSA (DMM) were tested as supports for immobilizing a novel engineered β-fructofuranosidase from Aspergillus japonicus for scFOS synthesis. Several immobilization parameters were estimated to ascertain the effectiveness of the carriers in immobilizing the enzyme. The performance of the immobilized biocatalysts are compared in terms of the yield of scFOS produced and reusability. The selection of carriers and reagents was motivated by the need to ensure safety of application in the production of food-grade products. The CA and AI900 both recorded impressive immobilization yields of 82 and 62%, respectively, while the DMM recorded 47%. Enzyme immobilizations on CA, AI900 and DMM showed activity recoveries of 23, 27, and 17%, respectively. The CA, AI900 immobilized and the free enzymes recorded their highest scFOS yields of 59, 53, and 61%, respectively. The AI900 immobilized enzyme produced a consistent scFOS yield and composition for 12 batch cycles but for the CA immobilized enzyme, only 6 batch cycles gave a consistent scFOS yield. In its first record of application in scFOS production, the AI900 anion exchange resin exhibited potential as an adequate carrier for industrial application with possible savings on cost of immobilization and reduced technical difficulty.     

Synthesis, spectroscopic characterization and structural studies of mixed ligand complexes of Sr(II) and Ba(II) with 2-hydroxybenzophenone and salicylaldehyde, hydroxyaromatic ketones or β-diketones: Crystal structure of 2-HOC6H4C(O)C6H5

Reactions of Sr(II) and Ba(II) chlorides with 2-hydroxybenzophenone and salicylaldehyde, hydroxyaromatic ketones or β-diketones in 1:1:1 molar ratios have resulted in the formation of mixed ligand complexes of the type [MLL′(H₂O)₂] (M = Sr(II) or Ba(II); HL = 2-hydroxybenzophenone and HL′ = salicylaldehyde, 2-hydroxyacetophenone, 2-hydroxypropiophenone, pentane-2,4-dione, 1-phenylbutane-1,3-dione or 1,3-diphenylpropane-1,3-dione). These complexes have been characterized by elemental analyses, TLC, IR and ¹H NMR spectroscopy.     

Diversity and polymorphism in AHL-lactonase gene (aiiA) of Bacillus

To explore bacterial diversity for elucidating genetic variability in acylhomoserine lactone (AHL) lactonase structure, we screened 800 bacterial strains. It revealed the presence of a quorum quenching (QQ) AHL-lactonase gene (aiiA) in 42 strains. These 42 strains were identified using rrs (16S rDNA) sequencing as Bacillus strains, predominantly B. cereus. An in silico restriction endonuclease (RE) digestion of 22 AHL lactonase gene (aiiA) sequences (from NCBI database) belonging to 9 different genera, along with 42 aiiA gene sequences from different Bacillus spp. (isolated here) with 14 type II REs, revealed distinct patterns of fragments (nucleotide length and order) with four REs; AluI, DpnII, RsaI, and Tru9I. Our study reflects on the biodiversity of aiiA among Bacillus species. Bacillus sp. strain MBG11 with polymorphism (115Alanine > Valine) may confer increased stability to AHL lactonase, and can be a potential candidate for heterologous expression and mass production. Microbes with ability to produce AHL-lactonases degrade quorum sensing signals such as AHL by opening of the lactone ring. The naturally occurring diversity of QQ molecules provides opportunities to use them for preventing bacterial infections, spoilage of food, and bioremediation.     

Treatment of periodontal disease using xanthan based chlorhexidine gel

People of all ages are suffering from periodontal disease. It causes indirect damage in the oral cavity. It is of interest to evaluate the efficacy of xanthan-based chlorhexidine gel (Xan-CHX) in patients with mild-severe chronic periodontitis. Five patients with 60 sites were divided in two groups. Group A (treated with SRP) and group B (treated with Chlosite i.e., SRP + CHL). The recorded clinical parameters were Plaque index (PI), Gingival index (GI), Bleeding index (BI), and Clinical attachment Level (CAL) with sub gingival plaque subjected to microbial analysis. Significant reduction was observed in both groups. However, group B (treated with Chlosite i.e., SRP + CHL) showed statistically significant improvement on above mentioned parameters as compared to group A. Data suggest that in the treatment of periodontal disease (viz. PI, GI, BI and CAL) combination of SRP and Chlosite showed added benefits over only SRP.     

Study of trivalent samarium ion embedded lithium‐based borate glass for high‐density optical memory devices

Sm³⁺ ions doped strontium lithium lead borate glasses (SLLB:Sm) were prepared using a conventional melt‐quenching technique. The glasses were analyzed using X‐ray diffractometry and Fourier transform infrared spectroscopy, optical absorption, fluorescence spectral analysis, and fluorescence lifetime decay. The Judd–Ofelt (J–O) parameters and radiative parameters of the SLLB:Sm10 glass (1.0 mol% Sm³⁺ ion‐doped glass) were calculated using J–O theory. From the emission spectra, among all the synthesized glass, SLLB:Sm10 glass had the highest emission intensity for ⁴G_5/2→⁶H_11/2 transition (610 nm). Emission parameters, such as stimulated emission cross‐section and optical gain bandwidth, were calculated. For all concentrations of Sm³⁺ ions, the decay profile showed an exponential nature and decreased when the Sm³⁺ ion concentration was increased due to a concentration quenching effect. This result suggests that the synthesized SLLB:Sm10 glass could be used for application in high‐density optical memory devices.     

A non‐canonical rhodopsin‐mediated insulin receptor signaling pathway in retinal photoreceptor neurons

We previously reported a ligand‐independent and rhodopsin‐dependent insulin receptor (IR) neuroprotective signaling pathway in both rod and cone photoreceptor cells, which is activated through protein–protein interaction. Our previous studies were performed with either retina or isolated rod or cone outer segment preparations and the expression of IR signaling proteins were examined. The isolation of outer segments with large portions of the attached inner segments is a technical challenge. Optiprep? density gradient medium has been used to isolate the cells and subcellular organelles, Optiprep? is a non‐ionic iodixanol‐based medium with a density of 1.320 g/mL. We employed this method to examine the expression of IR and its signaling proteins, and activation of one of the downstream effectors of the IR in isolated photoreceptor cells. Identification of the signaling complexes will be helpful for therapeutic targeting in disease conditions.