MISSING DATA SAMPLES: SYSTEMATIZATION AND CONDUCTING METHODS-A REVIEW

This paper investigates the phenomenon of the incomplete data samples by analyzing their structure and also resolves the necessary procedures regularly used in missing data analysis. The research gives a crucial perceptive of the techniques and mechanisms needed in dealing with missing data issues in general. The motivation for writing this brief overview of the topic lies in the fact that statistical researchers inevitably meet missing data in their analysis. The authors examine the applicability of regular approaches for handling the missing data situations. Based on several previously published results, the authors provide an example of the incomplete data sample model that can be implemented when confronting with specific missing data patterns.

Biocompatible microemulsions for improved dermal delivery of sertaconazole nitrate: Phase behavior study and microstructure influence on drug biopharamaceutical properties

The aim of this study was development of biocompatible topical microemulsions (MEs) for incorporation and improved dermal delivery of sertaconazole nitrate (SN). For this purpose, phase behavior and microstructure of pseudo-ternary glycereth-7-caprylate/caprate (Emanon EV-E, EV)/cosurfactant/Capryol (TM) 90/water systems were investigated. Furhermore, the influence of these properties on the drug skin delivery was also assessed. Expansion of ME single-phase regions with the use of short chain alcohols was a consequence of the more fluid interface when compared to other investigated systems, which was confirmed by electron paramagnetic resonance spectroscopy-EPR. The chosen bicontinuous to inverted bicontinuous formulations were assessed against the ME based on polysorbate 80 as referent sample. Despite incorporation of SN within the selected formulations induced similar alternations in electrical conductivity, viscosity and pH values, obtained EPR spectra suggested different SN localization: within the oil phase (for most of the EV based formulations), or interacting with the interface (polysorbate 80 based formulation). Due to higher in vitro drug release (12.24%-18.53%), ex vivo SN penetration into porcine ear skin (dermal retention Enhancement Ratio (ERO) ranged from 2.66 to 4.25) and pronounced antifungal activity, the chosen MEs represent promising vehicles for dermal delivery of SN in treatment of cutaneous fungal infections. The biopharmaceutical and skin performance differences obtained with different formulations were possible to be explained on the basis of their physicochemical characteristics.This is the peer-reviewed version of the article: Pajic, N. B., Nikolić, I., Mitsou, E., Papadimitriou, V., Xenakis, A., Randjelović, D., Dobricic, V., Smitran, A., Cekic, N., Calija, B.,& Savić, S. D. (2018). Biocompatible microemulsions for improved dermal delivery of sertaconazole nitrate: Phase behavior study and microstructure influence on drug biopharamaceutical properties. Journal of Molecular LiquidsElsevier Science Bv, Amsterdam., 272, 746-758. [https://doi.org/10.1016/j.molliq.2018.10.002]The published version: [https://cer.ihtm.bg.ac.rs/handle/123456789/2360

Characterisation of levan and levan/gelatin blend films using AFM and FTIR spectroscopy

Food packaging concerns a preservation and protection of all types of food and therefore is important part of food technology. Today, synthetic packaging films are predominantly used, however they are very slow or only partially degradable. Due to incomplete degradation of synthetic polymers, micro and nanoplastic could be produced, which is in last year’s considered as a new threat to human health. Microbial polysaccharide levan is natural biopolymer produced by broad range of microorganisms and has promising properties such as biocompatibility, renewability, high molecular height, low viscous nature, antioxidant and prebiotic activities. Gelatine, due to its affordability, biodegradability, low cost and excellent functional and film properties is currently the most preferred protein derivative

Curcumin loaded pegylated nanoemulsions designed for maintained antioxidant effects and improved bioavailability: A pilot study on rats

The current study describes the experimental design guided development of PEGylated nanoemulsions as parenteral delivery systems for curcumin, a powerful antioxidant, as well as the evaluation of their physicochemical characteristics and antioxidant activity during the two years of storage. Experimental design setup helped development of nanoemulsion templates with critical quality attributes in line with parenteral application route. Curcumin-loaded nanoemulsions showed mean droplet size about 105 nm, polydispersity index <0.15, zeta potential of −40 mV, and acceptable osmolality of about 550 mOsm/kg. After two years of storage at room temperature, all formulations remained stable. Moreover, antioxidant activity remained intact, as demonstrated by DPPH (IC50 values 0.078–0.075 mg/mL after two years) and FRAPS assays. In vitro release testing proved that PEGylated phospholipids slowed down the curcumin release from nanoemulsions. The nanoemulsion carrier has been proven safe by the MTT test conducted with MRC-5 cell line, and effective on LS cell line. Results from the pharmacokinetic pilot study implied the PEGylated nanoemulsions improved plasma residence of curcumin 20 min after intravenous administration, compared to the non-PEGylated nanoemulsion (two-fold higher) or curcumin solution (three-fold higher). Overall, conclusion suggests that developed PEGylated nanoemulsions present an acceptable delivery system for parenteral administration of curcumin, being effective in preserving its stability and antioxidant capacity at the level highly comparable to the initial findings

ROLE OF GENDER IN PHEMENON OF NON-SUICIDAL SELF-INJURIES AND SUICIDE ATTEMPT AMONG CLINICAL POPULATION OF ADOLESCENTS

Non suicidal self-injury is defined as intentional self-inflicted injury without the intent to die. Suicide attempt is defined as a non-fatal, self-directed, potentially injurious behavior with the intent to die. Although distinct behaviors, they are frequently associated and possibly clinically related. The aims of this study are to ex-plore demographic data, social-demographic differences between genders, co-occurrence of non-suicidal self-injuries with suicide attempt, their association with gender and clinical variables. Retrospective cohort study on 143 patient admitted in Clinic for mental disorders „Dr Laza Lazarevic“, aged 14 to 18 years, between January 2015 and January 2016. Information were obtained from database and included two categories of variables: socio-demo-graphic (age, gender, education level, current living situation) and clinical variables (abuse, neglect, peer violence, aggressive behavior, non-suicidal self-injuries, suicide attempt and others). The mean age of adolescents was 15.8 years, with female being more frequent in the sample (51.4%). The incidence of Mood disorders was significantly higher (p<0.05) in female compared to male (χ²꞊3,96, df꞊1, rC꞊0.16, p꞊0.04). A significantly higher incidence (p<0.05) of non-suicidal self-injury (χ²꞊11.15, df꞊1, rC꞊0.27, p꞊0.001) and suicide attempt was found in female compared to male (χ²꞊5.38, df꞊1, rC꞊0.19, p꞊0.02). No statistically sig-nificant difference was found in their simultaneous occurrence compared to total population of hospitalized adolescents. The findings of the present study demonstrated that non-suicidal self-injury and suicide attempt occur in clinical population of adolescent more often among female then in male adolescents

Challenging Ergonomics Risks with Smart Wearable Extension Sensors

Concerning occupational safety, the aim of ergonomics as a scientific discipline is to study and adjust working conditions, worker equipment, and work processes from a psychological, physiological, and anatomical aspect instead of adapting the worker to the needs of the job. This paper will discuss and analyze the potential of the garment-embedded body posture tracking sensor and its usage as standard working equipment, which is meant to help correct improper and high-risk upper body positions during prolonged and static work activities. The analysis evaluation cross-reference is based on the Rapid Upper Limb Assessment ergonomics risk assessment tool. Signals generated by the wearable are meant to help the wearer and observer promptly-continuously detect and correct bad posture. The results show a positive progression of workers’ body posture to reduce the ergonomic risks this research covers. It can be concluded that wearable technology and sensors would significantly contribute to the observer as the evaluation tool and the wearer to spot the risk factors promptly and self-correct them independently. This feature would help workers learn and improve the correct habits of correcting ergonomically incorrect body postures when performing work tasks

Distance visual acuity in air force pilots and student pilots when exposed to + Gz acceleration in human centrifuge

Background/Aim. High speeds that modern aircraft develop during take-off, flight and landing place an additional strain on the organ of vision. Owing to its considerable practical implementation in air combat, the effect of +Gz acceleration on the organ of vision is considered increasingly important for research. Substantial changes in visual functions may occur during high acceleration onset rates. However, it is important for a pilot to maintain visual acuity in order to be able to monitor new functional displays for rapid orientation, scan the configuration of terrain, display of weapons systems and enemy aircraft and deal with additional issues of the complexity of spatial orientation. The aim of the investigation was to establish whether distance visual acuity in air force pilots and student pilots is affected when exposed to +Gz acceleration. Methods. The study was performed on a defined population consisting of 95 respondents from 21 to 45 years of age divided into two groups. The first group included 65 air force pilots and the second group comprised of 30 student pilots, all of whom were exposed to an acceleration of +5.5 Gz. The testing was performed in a human centrifuge, which mimics conditions of real Gz acceleration, in the Department of Biodynamics in Aero Medical Institute (Zemun, Serbia). We examined the obtained differences in distance visual acuity before and after exposure to acceleration. Results. After the testing, all respondents in the group of air force pilots had distance visual acuity of 1.0, while in the group of student pilots a statistically significant difference in distance visual acuity was observed after being exposed to +Gz acceleration. Conclusion. Transient changes in distant visual acuity were more pronounced in the group of student pilots in comparison with the changes in visual acuity in the air force pilots when exposed to the same acceleration values (+5Gz acceleration). Since change in distance visual acuity is the most sensitive physiological indicator when exposed to high acceleration, individual physiological pilot training in the human centrifuge increases tolerance to accelerations, which is important for flight safety in both peacetime and combat conditions