Analysis of Fragmentation Pathways of Peptide Modified with Quaternary Ammonium and Phosphonium Group as Ionization Enhancers

Peptide modification by a quaternary ammonium group containing a permanent positive charge is a promising method of increasing the ionization efficiency of the analyzed compounds, making ultra-sensitive detection even at the attomolar level possible. Charge-derivatized peptides may undergo both charge remote (ChR) and charge-directed (ChD) fragmentation. A series of model peptide conjugates derivatized with N,N,N-triethyloammonium (TEA), 1-azoniabicyclo[2.2.2]octane (ABCO), 2,4,6-triphenylopyridinium (TPP) and tris(2,4,6-trimetoxyphenylo)phosphonium (TMPP) groups were analyzed by their fragmentation pathways both in collision-induced dissociation (CID) and electron-capture dissociation (ECD) mode. The effect of the fixed-charge tag type and peptide sequence on the fragmentation pathways was investigated. We found that the aspartic acid effect plays a crucial role in the CID fragmentation of TPP and TEA peptide conjugates whereas it was not resolved for the peptides derivatized with the phosphonium group. ECD spectra are mostly dominated by cn ions. ECD fragmentation of TMPP-modified peptides results in the formation of intense fragments derived from this fixed-charge tag, which may serve as reporter ion.

Clinical study of Evaluation of the Effect of Tranexamic Acid in Primary Cleft Palate Surgery in Children

Aim : To evaluate tranexamic acid effect on quality of surgery. Design: Double-blind study, Prospective and randomized Place & time of study: June 2020 to may 2021Allama iqbal memorial trust hospital Gujranwala. Methods: Two groups of candidates were made. The saline was administered to the control group whereas tranexamic acid was administered as 0.01g/kg in a bolus form, before surgical incision to tranexamic acid group. On a 10-point scale, grading of surgical field, primary hemorrhage and satisfaction of surgeon Results: As far as operating surgeon satisfaction is concerned, noteworthy improvement was witnessed and evaluation of surgery in case of control individuals group as compared to in case of test individual group in the tranexamic acid individuals group was estimated against the control members of group. Conclusion: tranexamic acid was given in dosage of 0.01g/kg of before surgical incision showed improved in a great way in surgical field during repairing of cleft palate operation. Keywords: tranexamic acid surgical field, pediatric, palatoplasty satisfaction, cleft palate

Mathematical modelling of carbonate reservoir dissolution and prediction of the controlled hydrochloric acid treatment efficiency

The article presents the theoretical studies results of hydrochloric acid compositions filtration in carbonate collectors porous media saturated with two-phase formation liquid. Solution of filtration problem in the process of carbonate rock leaching with possible regulation of process by hydrocarbon solvents is considered. Numerical algorithm of acid effect on oil-saturated formation is proposed and tested, which allows to determine the following parameters of filtration flow: concentration of hydrochloric acid, distribution of water saturation, pressure and other parameters. A mathematical model of the carbonate collector dissolution process using composite solvents has been developed, which allows predicting technological indicators of acid impact efficiency.