Interaction of an easterly system with a westerly system and its associated weather over southern Peninsula

During the week 11-17 April 1996 southern Peninsula received good rainfall especially with heavy rainfall on 13 and 15 April 1996 in Tamilnadu making the seasonal rainfall from 1 March to 17 April 1996 into large excess in south interior Kamataka and excess in Tamilnadu and north interior Kamataka. In this paper. an attempt is made to investigate in the synoptic situations leading to the large excess rainfall over these areas during the week 11- 17 April 1996.

Mechanisms of modulation of pre-mRNA 3D structural scaffolds for splicing substrate definition

Coordination of different serine-arginine-rich (SR) proteins - a class of critical splicing activators - facilitates recognition of the highly degenerate cognate splice signal sequences against the background sequences. Yet, the mechanistic details of their actions remain unclear. Here we show that cooperative binding of SR proteins to exonic and intronic motifs remodels the pre-mRNA 3D structural scaffold. The scaffold generated by pre-mRNA-specific combinations of different SR proteins in an appropriate stoichiometry is recognized by U1 snRNP. A large excess of U1 snRNP particles displaces the majority of the bound SR protein molecules from the remodeled pre-mRNA. A higher than optimal stoichiometry of SR proteins occludes the binding sites on the pre-mRNA, raising the U1 snRNP levels required for SR protein displacement and potentially impeding spliceosome assembly. This novel step is important for distinguishing the substrate and the non-substrate by U2AF65 - the primary 3' splice site-recognizing factor. Overall, this work elucidates early regulatory steps of mammalian splicing substrate definition by SR proteins.

Synthesizing highly fluorinated oligophenyls via Negishi coupling of fluoroarylzinc pivalates

Previously established general synthetic methods for the synthesis of highly fluorinated biphenyls using Suzuki-Miyaura protocols require the use of organoboron compounds which are not very stable under reactions conditions and thus need to be used in large excess. Herein we report an improved general strategy for the synthesis of highly fluorinated biphenyls, terphenyls and phenyl-substituted terphenyls using organozinc pivalates. The influence of several parameters was investigated: a) in a series of different monodentate phosphine ligands, X-Phos showed the best performance; b) a higher yield could be obtained for substrates bearing less steric hindrance or lower amount of fluorine substitution; c) as iodinated substrates decomposed during the reaction, brominated electrophiles were found to be superior. The presented protocol is scalable, versatile, and works with commonly used and commercially available phosphine ligands (X Phos) and palladium sources (Pd2dba3). Also, it does not need excess nucleophile usage for terphenyl synthesis and only a slight such excess for the preparation of phenyl substituted terphenyls.

Experimentally Calculated Study of the Effectiveness on the Process of Non-Catalytic Synthesis of Biodiesel in Reactors of Various Type

It was experimentally established that the dependence of the partial pressure of methanol on the molar fraction of methanol in oil shows a pronounced negative deviation from Raoul’s law, which significantly changes the idea of the influence of a large excess of methanol during non-catalytic synthesis of biodiesel. The efficiency of use of a molar excess of methanol is reduced as it grows, and with a more than 10-fold molar excess of the amount of reacted methanol, is practically constant. The comparison of biodiesel production processes in the range 220–235 °C showed that a slight change in the process temperature more effectively affects the biodiesel yield than an increase in the molar excess of methanol. A mathematical model of the process of transesterification of rapeseed oil in reactors of various types (batch and tubular reactors) is developed. A satisfactory correlation between the experimental and calculated data was observed. The calculation showed that the rate constants of the reverse reactions at 230 °C were not significant.

THERMOSTABLE EPOXIDE COMPOSITION BASED ON AROMATIC DIAMIDODISULFOIMIDE RESIN

New epoxide oligomers have been obtained by the interaction of p-phenylenediaminediamidodisulfoimide with a large excess of epichlorohydrin in the presence of triethylbenzylammonium chloride. The synthesized epoxide oligomers are a viscous product of dark brown color, well soluble in aprotic solvents (DMFA, DMSO), as well as in acetone and dioxane. These cooligomers include hydroxynaphthylene and phenylenediimine structural fragments possessing solubility, meltability and high reactivity in the reactions with the oxirane ring of epoxide compounds in composition of macromolecules. The cooligomer of m-phenylenediamine with α-naphthol was used for curing of diamidodisulfoimide resin.

MONSOON SEASON (June - September 2019)

The rainfall over the country as a whole during the monsoon season (June-September) was 110% of its Long Period Average (LPA) and thus categorized as a normal* monsoon year. Seasonal rainfall over Central India region (1263.2 mm) was large excess with 129% of LPA rainfallwhich was third highest since 1901 after the years 1994 (1311.3 mm) and 1961 (1297 mm) for the broad geographical region of Central India. Rainfall over South Peninsula (116% of LPA) region was excess, over Northwest India (99% of LPA) was normal and East and Northeast Region remained deficient at 88% of LPA. Southwest monsoon reached parts over the Andaman Sea on 18 May, two days earlier than its normal date. However, it set in over Kerala on 8 June, 7 days later than its normal date and covered the entire country by 19 July with a delay of 4 days. Typically, the monsoon current begins to withdraw around 1 September, with the retreat completed by 15 October. This year, the retreat began on 9 October, marking the longest ever delay and was complete by 16 October in just 8 days. The withdrawal of Southwest monsoon from the entire country and the commencement of the Northeast monsoon rains occurred simultaneously on 16 October. Sometimes there is a gap of 10 days between the two seasons. Due to neutral ENSO conditions and weak Madden Julian Oscillation (MJO), their influence on the monsoon were nearly absent especially in the second half of the season. Positive Indian Ocean Dipole (IOD) episode was observed since the beginning of the monsoon season and its rapid strengthening to the strongest ever was observed by mid of the monsoon season.

Comparative Studies of Mechanochemically Synthesized Insoluble Beta-Cyclodextrin Polymers

: Cyclodextrin (CD) polymers are covalently linked hollow structures that are a network of less flexible macrocycles. They can be divided into two main groups: a) soluble (CDPS); and b) insoluble (CDPIS) polymers. These two types are generally prepared in a similar reaction, and the CD/reagent ratio determines the final properties of the reaction product. Changing this ratio of the generally bifunctionalized crosslinking agent and reaction conditions can lead to CDPS or CDPIS. The classical synthetic way in solution often leads to partial reagent(s) degradation, which frequently results in poorly reproducible products. At the same CD/reagent ratio, the reaction in solution yielded soluble CD polymers, whereas the reaction under mechanochemical conditions produced insoluble CD polymers. Usually, further derivatization of CDPIS or polymerization of derivatized CDs can be difficult or even impossible. The reactivity of hydroxyl groups in methylated CDs is limited so that reactions generally require high-boiling solvents and/or a large excess of reagent. This paper presents an economical, reproducible, and well-scalable synthetic method for producing some insoluble CD polymers. The physicochemical and adsorption properties of CDPIS prepared in a planetary ball mill are also compared.

Controlled Polyelectrolyte Association of Chitosan and Carboxylated Nano-Fibrillated Cellulose by Desalting

We prepared chitosan (CHI) hydrogels reinforced with highly charged cellulose nanofibrils (CNF) by the desalting method. To this end, the screening of electrostatic interactions between CHI polycation and CNF polyanion was performed by adding NaCl at 0.4 mol/L to the chitosan acetate solution and to the cellulose nanofibrils suspension. The polyelectrolyte complexation between CHI polycation and CNF polyanion was then triggered by desalting the CHI/CNF aqueous mixture by multistep dialysis, in large excess of chitosan. Further gelation of non-complexed CHI was performed by alkaline neutralization of the polymer, yielding high reinforcement effects as probed by the viscoelastic properties of the final hydrogel. The results showed that polyelectrolyte association by desalting can be achieved with a polyanionic nanoparticle partner. Beyond obtaining hydrogel with improved mechanical performance, these composite hydrogels may serve as precursor for dried solid forms with high mechanical properties.

The Biotin–Avidin Interaction in Biotinylated Gold Nanoparticles and the Modulation of Their Aggregation

The biotin–avidin interaction is used as a binding tool for the conjugation of biomolecules for more diverse applications; these include nanoparticle conjugation. Despite this, a thorough investigation on the different aggregates that may result from the interaction of biotinylated nanoparticles (gold nanoparticles, AuNPs, in this work) with avidin has not been carried out so far. In this paper, we address this problem and show the type of aggregates formed under thermodynamic and kinetic control by varying the biotinylated AuNP/avidin ratio and the order of addition of the two partners. The analysis was performed by also addressing the amount of protein able to interact with the AuNPs surface and is fully supported by the TEM images collected for the different samples and the shift of the surface plasmon resonance band. We show that the percentage of saturation depends on the size of the nanoparticles, and larger nanoparticles (19 nm in diameter) manage to accommodate a relatively larger amount of avidins than smaller ones (11 nm). The AuNPs are isolated or form small clusters (mostly dimers or trimers) when a large excess or a very low amount of avidin is present, respectively, or form large clusters at stoichiometric concentration of the protein. Daisy-like systems are formed under kinetic control conditions when nanoparticles first covered with the protein are treated with a second batch of biotinylated ones but devoid of avidin.