A DFT Study on the Polarizability of Di-substituted Arene (o-, m-, p-) Molecules used as Supercharging Reagents during Electrospray Ionization Mass Spectrometry

Abaye, Daniel A.,Aniagyei, Albert,Adedia, David,Nielsen, Birthe V.,Opoku, Francis Korean Society for Mass Spectrometry 2022 Mass spectrometry letters Vol.13 No.3

During electrospray ionization mass spectrometry (ESI-MS) analysis of proteins, the addition of supercharging agents allows for adjusting the maximal charge state, affecting the charge state distribution, and increases the number of ions reaching the detector thus, improving signal detection. We postulate that in di-substituted arene isomers, molecules with higher polarizability values should generate greater interactions and hence elicit higher signal intensities. Polarizability is an electronic parameter which has been demonstrated to predict many chemical interactions. Many properties can be predicted based on charge polarization. Molecular polarizability is a vital descriptor for explaining intermolecular interactions. We employed DFT (density functional/Hartree-Fock hybrid model, B3LYP)-derived descriptors and computed molecular polarizability for ten disubstituted arene reagents, each set made up of three (ortho, meta, para) isomers, with reported use as supercharging reagents during ESI experiments. The atomic electronic inputs were ionization potential (IP), electron affinity (EA), electronegativity (𝛘), hardness (η), chemical potential (µ), and dipole moment (D). We determined that the para isomers showed the highest polarizability values in nine of the ten sets. There was no difference between the ortho and meta isomers. Polarizability also increased with increasing complexity of the substituents on the benzene ring. Polarizability correlated positively with IP, EA, 𝛘, η, and D but correlated negatively with chemical potential. This DFT study predicts that the para isomers of di-substituted arene isomers should elicit the strongest ESI responses. An experimental comparison of the three isomers, especially of larger supercharging molecules, could be carried out to establish this premise.

The Influence of Mixed Solvents Volatility on Charge State Distribution of Peptides During Positive Electrospray Ionization Mass Spectrometry

Nielsen, Birthe V.,Abaye, Daniel A.,Nguyen, Minh T.L. Korean Society for Mass Spectrometry 2017 Mass spectrometry letters Vol.2 No.4

Understanding the mechanisms that control and concentrate the observed electrospray ionisation (ESI) response from peptides is important. Controlling these mechanisms can improve signal-to-noise ratio in the mass spectrum, and enhances the generation of intact ions, and thus, improves the detection of peptides when analysing mixtures. The effects of different mixtures of aqueous: organic solvents (25, 50, 75%; v/v): formic acid solution (at pH 3.26) compositions on the ESI response and charge-state distribution (CSD) during mass spectrometry (MS) were determined in a group of biologically active peptides (molecular wt range 1.3 - 3.3 kDa). The ESI response is dependent on type of organic solvent in the mobile phase mixture and therefore, solvent choice affects optimal ion intensities. As expected, intact peptide ions gave a more intense ESI signal in polar protic solvent mixtures than in the low polarity solvent. However, for four out of the five analysed peptides, neither the ESI response nor the CSD were affected by the volatility of the solvent mixture. Therefore, in solvent mixtures, as the composition changes during the evaporation processes, the $pK_b$ of the amino acid composition is a better predictor of multiple charging of the peptides.

The Influence of Mixed Solvents Volatility on Charge State Distribution of Peptides During Positive Electrospray Ionization Mass Spectrometry

Birthe V. Nielsen,Daniel A. Abaye,Minh T. L. Nguyen 사단법인 한국질량분석학회 2017 Mass spectrometry letters Vol.8 No.2

Understanding the mechanisms that control and concentrate the observed electrospray ionisation (ESI) response from peptides is important. Controlling these mechanisms can improve signal-to-noise ratio in the mass spectrum, and enhances the generation of intact ions, and thus, improves the detection of peptides when analysing mixtures. The effects of different mixtures of aqueous: organic solvents (25, 50, 75%; v/v): formic acid solution (at pH 3.26) compositions on the ESI response and chargestate distribution (CSD) during mass spectrometry (MS) were determined in a group of biologically active peptides (molecular wt range 1.3 - 3.3 kDa). The ESI response is dependent on type of organic solvent in the mobile phase mixture and therefore, solvent choice affects optimal ion intensities. As expected, intact peptide ions gave a more intense ESI signal in polar protic solvent mixtures than in the low polarity solvent. However, for four out of the five analysed peptides, neither the ESI response nor the CSD were affected by the volatility of the solvent mixture. Therefore, in solvent mixtures, as the composition changes during the evaporation processes, the pKb of the amino acid composition is a better predictor of multiple charging of the peptides.

Empowering Female Civil Servants through Education

Abay Akemachew GETAHUN 이화여자대학교 아시아여성학센터 2016 이화여자대학교 아시아여성학센터 학술대회자료집 Vol.2016 No.1

Empowerment is the process of creating enabling conditions for marginalized or discriminated groups of people so as to obtain and widen opportunities to contribute and benefit from the socioeconomic and political spheres. Women are those who make up half of the world’s population needs to be empowered. This is due to the fact that although the degree varies from one country to the other, women around the globe have been facing prejudice and discrimination based on their gender for several years. Education is one of the key strategies to empower women in terms of enhancing their knowledge and skill, increasing their representation at public spaces, to have more access to and control over resources and the like. They primary responsibility for women’s empowerment rests in their hands. However, other stakeholders like governments have key roles to their empowerment especially by creating conducive conditions. The Ethiopian Civil Service University as one of the governmental Higher Learning Institutions of Ethiopia has been playing a critical role to empower female civil servants through its various educational programs. Especially, the initiative taken by taking the University to admit female students from formerly marginalized regional states of Ethiopia through alternative admission program can be as one of its remarkable achievements.

Efficacy of Tibial Nerve Stimulation on Fecal Incontinence in Patients With Low Anterior Resection Syndrome Following Surgery for Colorectal Cancer

Aigul Tazhikova,Abay Makishev,Aizhan Bekisheva,Mariya Dmitriyeva,Medet Toleubayev,Alina Sabitova 대한재활의학회 2022 Annals of Rehabilitation Medicine Vol.46 No.3

Objective To systematically review the available literature on the efficacy of tibial nerve stimulation on faecal incontinence and quality of life in adult patients with low anterior resection syndrome following surgery for colorectal cancer. Methods A primary search of electronic databases was conducted adopting a combination of search terms related to the following areas of interest: “efficacy”, “tibial nerve stimulation” and “low anterior resection syndrome”. A secondary search of the grey literature was performed in addition to checking the reference list of included studies and review papers. The review was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A descriptive analysis was used to integrate the review findings. Results Five distinct studies involving 116 patients met the inclusion criteria for the review. The included studies suggest that tibial nerve stimulation may have a positive effect on faecal incontinence and quality of life in some patients with low anterior resection syndrome and might be considered as an additional treatment option. Conclusion There were a limited number of studies and a great degree of heterogeneity of evidence due to differences in participants’ baseline characteristics, dropout rates, and follow-up periods. Further research adopting validated, consistent, and complex outcome assessment methods is recommended to determine the efficacy of tibial nerve stimulation for treatment of patients with low anterior resection syndrome.

Portal Vein Thrombosis after Liver Transplantation: Prevention and Treatment

( Zhaksylyk Doskaliyev ),( Marlen Doskali ),( Abay Baigenzhin ),( Nurbek Ilyassov ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Among complications after liver transplantation the vascular causes of graft dysfunction remains as a devastating complication and its challenging clinical condition requires a multidisciplinary approach for management. Methods: From January 2013 to January 2017, 38 LDLTs were performed in our center. Operation procedures were performed by standard methods in donor and recipients. In all donors right hepatectomies were performed. Risk factors and variables associated with the transplant and the post-transplant period were analyzed. Results: At a median follow up of 3 years, both the patient and graft survival were 82%. The main causes of transplantation were primary biliary cirrhosis (50%), viral hepatitis (30%) and other liver diseases. The median age of the recipients at the time of LDLT was 43.9±17.2 (19-65 years). Recipients average hospital stay was 30±5 days (23-38 days, median 30 days) found. Vascular and biliary complications were the leading cause of reoperation, graft loss and retransplantation. Conclusions: Portal vein thrombosis is an awkward problem to treat after liver transplantation because a different portal inflow is difficult to establish. We successfully applied the heparin-based treatment in 3 patients, but graft loss were found in 2 patients. It is reliable to use a local delivery of thrombolytic therapy compare to systemic therapy because of a high risk of systemic bleeding in post-liver transplant patients. Survival rate depends on presence of PVT in cirrhotic liver before surgery.

Management of a Surgical Treatment of Patients with Pancreatic Cancer

( Marat Kuzikeyev ),( Timur Nasritdinov ),( Abay Jumanov ),( Sergey Lashkul ),( Innara Turkpenova ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: In this study our purpose is analysis of retrospective patients with I-III stages which went to the surgery and postoperative chemo - and radiotherapy in Kazakh Scientific Research Institute of Oncology and Radiology. Methods: Totally 64 patients between 2009 and 2016 underwent surgical treatment of pancreatic cancer and follow-up. Which of them: pancreatoduodenal resection was performed in 37 patients, corpocaudal resection in 12 patients, distal pancreas resection in 12 patients, total pancreatectomy performed to 3 patients. Resequence in pancreatic head cancer was 25.5%, with carcinoma of the body and tail - 10.1%. Results: Postoperative mortality for pancreatoduodenal resection was 8.7% (in the last 5 years - 3.5%), distal resection was 13.3%. The average life expectancy after pancreatoduodenal resection was 17.4 months, pancreatectomy - 8 months, distal subtotal pancreas resection - 11.2 months. Three years after pancreatoduodenal resections, 14.7% lived, and the 5-year survival rate was 4.4%. After palliative surgery, the average life expectancy was 5.2 months. The best long-term results were observed when applying a complex and combined treatment. In distal pancreas resection postoperative use of SBRT/IMRT radiation therapy or induced chemotherapy, give almost same results. In this way, improvement of the treatment results of pancreatic cancer is possible with early diagnosis and applying of complex and combined treatment. Patients should be classified and treated with a multidisciplinary approach at specialized centers. Conclusions: In this way, improvement of the treatment results of pancreatic cancer is possible with early diagnosis and applying of complex and combined treatment. Patients should be classified and treated with a multidisciplinary approach at specialized centers.

Inhibitory Effects of Some Plant Essential Oils Against Arcobacter butzleri and Potential for Rosemary Oil as a Natural Food Preservative

Reyhan Irkin,Secil Abay,Fuat Aydin 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.3

We investigated the inhibitory activity of commercially marketed essential oils of mint, rosemary, orange, sage, cinnamon, bay, clove, and cumin against Arcobacter butzleri and Arcobacter skirrowii and the effects of the essential oil of rosemary against A. butzleri in a cooked minced beef system. Using the disc diffusion method to determine the inhibitory activities of these plant essential oils against strains of Arcobacter, we found that those of rosemary, bay, cinnamon, and clove had strong inhibitory activity against these organisms, whereas the essential oils of cumin, mint, and sage failed to show inhibitory activity against most of the Arcobacter strains tested. The 0.5% (vol/wt) essential oil of rosemary was completely inhibitory against A. butzleri in the cooked minced beef system at 4°C. These essential oils may be further investigated as a natural solution to the food industry by creating an additional barrier (hurdle technology) to inhibit the growth of Arcobacter strains.

Quality of Same-Day Sputum Smears Microscopy and Presumptive Tuberculosis Patients Drop-out at Health Facilities of Addis Ababa, Ethiopia

( Boja Dufera Taddese ),( Abay Sisay Misganaw ) 대한결핵 및 호흡기학회 2020 Tuberculosis and Respiratory Diseases Vol.83 No.1

Background: Same-day sputum microcopy is recommended in areas where sputum smear microscopy external quality assessment (EQA) is effectively implemented and sturdy. In Addis Ababa, the status of EQA and drop-out of same-day sputum smear microcopy has not yet been assessed. The objective of this study was to assess the quality of same-day sputum smear microscopy and diagnostic drop-out of presumptive tuberculosis (TB) patients in health facilities (HFs) across Addis Ababa, Ethiopia. Methods: Amulti-analysis was conducted from September 2016 to July 2017 to determine the status of external quality assessment and diagnostic drop-out of presumptive TB patients registered for same-day sputum smear microscopy. Data was coded and entered in Microsoft Excel, and subsequently transferred and analyzed using SPSS version 20.0. Results: The drop-out of same-day sputum smear microscopy was 209 (6.2%). More than 33% of the specimens collected for purposes of same-day sputum smears were of poor quality. Among the selected HFs for the study: 13 (46.4%) used filter reagents prior to sputum smear staining while 75% of the selected HFs for the study used smear microscopy services interruption in a year. The sensitivity and specificity of the HFs participating in regional quality assessment scheme for the diagnosis of TB was 97.4% and 99.6%, respectively. Conclusion: The diagnostic drop-out of same-day sputum smear microscopy was high in Addis Ababa. Strengthening EQA, competency-based laboratory professionals training on sputum smear microscopy might reduce the reading errors in sputum smear. Awareness creation of the community on the benefits gained from completion of specimen provision for the same-day approach decreases diagnostic drop-out and enhances TB control program.

The First Experience of Radiotherapy on the Pancreas Cancer in KazIOR

( Oleg Trushenko ),( Marat Kuzikeyev ),( Abay Jumanov ),( Zhanat Pyssanova ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Despite the improvement of special treatment methods, the 5-year survival rate according to different authors is 1-10%. In 2016 in Kazakhstan, the number of people who fell ill at the PCa was 1028, while the one-year mortality rate was 65,1%. Radiation therapy (RT) is one of the treatment options for malignant neoplasm of the pancreas. Our purpose is to improve the treatment results of patients with PCa. Methods: The method of IMRT was applied in 8 patients with adenocarcinoma of the third stage. 5 of them (62.5%) are primary patients without any treatment, 3 (37.5%) - after not radical operations. At the end of the course of treatment with a patient with PCa, the quality of life did not worsen. There are no early radiation reactions of high toxicity (RTOG 3-4). The evaluation of the quality of the conducted RT was carried out by Multispiral Computed Tomography (MSCT) with contrast enhancement (bolus + per. os). Results: The best results are observed in a patient whose tumor size decreased from 6.1x5.1x3.8 cm to 4.1x3.8x3.7 cm in 1 month after radiation therapy. As a result, in 5 primary patients after 2,0 Gy per fraction to 55-60 Gy observed partial regression of the lesion, 3 patients underwent postoperative radiation therapy for prevention of disease recurrence (they are follow-up). Conclusions: The application of the technique of intensively modulated radiotherapy in patients with malignant neoplasm of the pancreas, increases access to new methods of treatment, and improves the quality of life and the survival rate.