66 research outputs found
Free climbing turtle, Emys orbicularis (Linnaeus, 1758) – vertical obstacles as a limitation for movement
Rigid shell of turtles restricts their mobility, although magnitude of these restrictions is not completely understood. Surprisingly, we witnessed a European Pond Turtle climbing a vertical obstacle in the field
Characteristics of functional morphology and ethology of Hermann's tortoises (Testudo hermanni)
Специфичан план грађе (чврст коштани оклоп и кратки екстремитети)
копненим корњачама поставља знатна ограничења у кретању и превазилажењу
препрека у станишту. Стога „компензација понашањем“ игра веома значајну
улогу у кретању копнених корњача. Да би се тестирале унутар- и
међупопулационе разлике у агилности и понашању шумске корњаче (Testudo
hermanni), вршена су три експеримента.
У првом експерименту корњаче су постављане на леђа и праћено је
понашање током превртања у усправан положај. Током другог експеримента,
теста скакања, корњаче су постављане на „негативну висинску препреку“
(хоризонталну површину на извесној висини изнад подлоге) и праћено је
понашање током силажења са ње. Трећим експериментом је тестирано понашање
корњача када се нађу „заглављене“ у вегетацији. Овом приликом је на предњи део
пластрона закачена омча ужета на чијем другом крају се налазио динамометар.
Праћено је понашање за време ослобађања од експерименталне апаратуре и
мерена је мишићна снага корњача. Параметри понашања добијени овим тестовима
су анализирани у односу на: морфолошке одлике (дужинске мере оклопа и ногу,
као и облик и величину карапакса), пол, узрасне категорије јединки и одлике
станишта.
Показано је да величина и облик тела значајно утичу на превртање
корњача. Крупније корњаче се теже преврћу него ситније, при чему висина
оклопа има позитиван, а дужина коштаних мостова негативан ефекат на
успешност усправљања. Међутим, применом геометријске морфометрије
показано је да промене облика оклопа услед повећања величине адултних
корњача, међу којима је и висина оклопа, ипак нису позитивно асоциране са превртањем...Unique body plan of terrestrial chelonians (rigid shell and short limbs) imposes
significant limitations to movements of these animals. Thus “behavioural
compensation” plays an important role in overcoming obstacles in their habitat, on the
daily basis.
To test intra- and inter-population differences in agility and behaviour of
Hermann’s tortoises (Testudo hermanni) during overcoming obstacles in their habitat,
three experiments were performed. In the first experiment tortoises were positioned on
their backs and their behaviour was noted during overturning. For the second
experiment, “jumping” test, tortoises were placed on „negative height obstacle“ (i.e.
horizontal surface above substrate) and their behaviour was noted during getting off it.
The third experiment tested behaviour of tortoises when they are “stuck” in dense
vegetation. For this test, a non-stretchable rope was attached on the front, protuberant
part of the plastron, while the dynamometer was attached on the other end of the rope.
Behaviour was noted during the animals’ attempts to liberate from the experimental
apparatus, and their muscular strength was measured. Behavioural parameters gathered
during these tests were analysed with regard to: morphological traits (length
measurements of shell and legs, and carapace shape and size), sex, age categories and
habitat features.
Body size and shape had significant effects on righting behaviour. Larger
tortoises were less efficient in overturning than the smaller ones. Shell height showed
positive, while length of bony bridges showed negative effect on the overturning
efficiency. However, geometric morphometrics showed that allometric shape changes in
adult tortoises (e.g. increase in relative carapace height) are not positively associated
with overturning. Differences between sexes in behaviour and agility were significant
only for the righting test, in which males were more successful, in half of the tested
localities. Males were previously considered more agile than females, but these
experiments propose that effect of sex on agility of tortoises is not as significant. Effect of age classes is analysed only in the “jumping” test..
Asbestos-related occupational risks
Despite the common knowledge of its harmful effects, asbestos is still used worldwide. It is estimated that about 125 million workers around the globe are exposed to asbestos in the workplace, while at least 90,000 people die annually from asbestos-related diseases. Asbestos dust is generated during mining, during separation of fibres from the serpentine part, and during processing in various industry branches. Employees involved in these production processes are especially at risk. Chronic exposure to asbestos can increase the risk of asbestosis, lung cancer, and mesothelioma. Asbestos exposure is usually reduced through replacement of asbestos with materials with similar properties and through the use of personal protective equipment. Disease prevention requires the implementation of strict asbestos removal procedures, ban on further use, and registering of persons exposed to asbestos, including their follow-up or preventive medical check-ups
Dostojanstvo ljudske osobe i pravo na život
Današnje suvremeno društvo stavlja nam rješenja mnogih proturječja društvene slike kakva danas vlada. Potrebno je samo malo dublje zahvatiti ispod površine da bi nam se otvorio širi horizont stvarne društveno-političke slike. Sastavni dio ljudskog društva jest i pravo, odnosno zakoni, prvo kao običajno pravo, a kasnije kodificirano pravo. U povijesti, možemo kroz pravne norme različitih pravnih sustava promatrati slike društva te kakve je poglede na život, na pravo na život, u konačnici na ljudsko dostojanstvo imala određena civilizacija. Kao postulat ovoga rada svrha je prikazati ljudska prava, ljudsko dostojanstvo i pogled na život, a posebno kroz učiteljstvo Katoličke Crkve, osvrćući se kratko i na učenje u Židovstvu u Tori, na rimsko pravo, te dakako na pozitivne pravne propise i pravne običaje uz slijed razvoja govora o dostojanstvu i pravu na život ljudske osobe, počevši od općeg pogleda na govor o ljudskom životu, preko promišljanja prvih kršćanskih vremena, do govora o dostojanstvu i čovjeku stvorenom na sliku Božju. Govoriti o ljudskim pravima i o dostojanstvu ljudske osobe nije nimalo zahvalna tema. Kroz povijest su ljudska prava i dostojanstvo ljudske osobe uvijek bili kamen spoticanja. U slučajevima takvog poremećaja, a mogli bismo čak reći i grubih povreda ljudskog dostojanstva i ljudskih prava, evanđeoski nauk kao objava koju Katolička Crkva baštini jest ključ u obrani i zaštiti onih koji su slabiji
The potential of corona charged aerosol detector for investigation of telmisartan-β-cyclodextrin inclusion complexes
Cyclodextrins (CDs) are widely used in pharmaceutical analysis due to its biodegradability and eco-friendly character. The particular structure of CDs, characterized by hydrophobic cavity, enables the formation of inclusion complexes with variety of organic compounds. As structures lacking chromophores, CDs could not be detected by Photodiode Array (PDA) detector and Corona Charged Aerosol Detector (CAD) was introduced as the most appropriate detector for the formed complexes. The aim of the study was to investigate the degree of complexation between telmisartan, used as a model substance, and β-CD. Moreover, the effect of different β-CD concentrations (5-15 mM) and pH of the aqueous part of mobile phase (3-7) on the degree of complexation was also assessed. The intensity of the formed complex appeared to be the highest when 15 mM β-CD was used for the complexation. Also, it was noticed that the increase in peak areas with an increasing β-CD concentration was more evident at pH 7 in comparison with the same trend at lower pH values. The reproducibility of the measurement was confirmed by low relative standard deviation (RSD) of peak areas within five measurements. These findings support the use of HPLC-CAD methods for studying the process of inclusion complexes formation
The chemical composition of chives (Allium schoenoprasum L.) essential oil
Allium schoenoprasum L. (Alliaceae), commonly called chives, is a small bulbous perennial, wild-growing or cultivated, plant widespread in Europe, Asia, and North America. It is commonly used as a culinary herb to impart mild onion flavor to many foods, including salads, soups, vegetables, and sauces. Also, chives are often cultivated in gardens due to their ornamental, as well as insect-repelling properties. However, there are only scarce literature data on the chemical composition of A. schoenoprasum essential oil [1,2].Herein, we performed thorough GC and GC-MS analysis of the essential oil obtained by hydrodistillation of the above-ground parts of A. schoenoprasum collected on the Šar Mountains. The analyses of the essential oil revealed that the main class of constituents was the organosulfur compounds representing around 60% of the analyzed oil. Among them, di- and trisulfides bearing a propyl, and alkyl- or alkenyl groups were the most abundant ones. The major component of the oil was methyl propyl trisulfide (8.3%), followed by (E)-1-propenyl propyl disulfide (4.6%), dipropyl trisulfide (4.6%), (E)-1-propenyl propyl trisulfide (4.5%), and dipropyl disulfide (3.8%). The qualitative composition of the analyzed oil was in a general agreement with the previously reported data [1,2], although the relative abundance of specific compounds differed. A peculiarity about the analyzed oil was that the oil was rich in hetero-penta-/hexa-/hepta- cyclic compounds (containing one or more sulfur and/or nitrogen atoms). Among these, stereoisomeric 4,6-diethyl-1,2,3,5-tetrathianes were the most abundant ones.
Primena koncepta razvoja ekološki prihvatljivih metoda tečne hromatografije u analitici lekova
Liquid chromatography is the most widely used analytical technique in course of research and development, as well as for routine investigation and quality control of pharmaceutical products. Having in mind the remarkable amount of waist resulting from the use of organic solvents, especially for reversed-phase liquid chromatography, recently ecologically acceptable concepts in chromatographic method development were noticed. The 3 Rrule (Reduce - Replace - Recycle) refers to the decrease of the toxic solvents use, their replacement with less toxic ones and the use of renewable solvents. This paper presents different solutions commonly applied in drug analysis that are in accordance with the 3 Rrule.Tečna hromatografija predstavlja najčešće korišćenu analitičku tehniku tokom istraživanja i razvoja, kao i u rutinskom ispitivanju i kontroli kvaliteta farmaceutskih proizvoda. Imajući u vidu značajnu količinu otpada koji potiče od upotrebljenih organskih rastvarača, naročito kod reverzno-fazne tečne hromatografije, zabeleženi su novi koncepti razvoja ekološki prihvatljive hromatografske metode. Pravilo 3 R (eng. Reduce - Replace - Recycle) podrazumeva smanjenu upotrebu toksičnih rastvarača, njihovu zamenu manje toksičnim rastvaračima, kao i rastvaračima koji se mogu prerađivati. U ovom radu su predstavljena različita rešenja koja zadovoljavaju 3 R pravila i često se primenjuju u analitici lekova
Nove strategije u razvoju ekološki prihvatljivih RP‐HPLC metoda primenom detektora naelektrisanja u aerosolu
Qualitative and quantitative assessment of drug substances and drug dosage forms is of utmost
importance for the quality control in pharmaceutical industry. Among the analytical techniques
available, high performance liquid chromatography (HPLC) stands out due to its high efficiency and
robustness. But, HPLC is also characterized by high consumption of toxic organic solvents used both for
method development and routine analyses. These solvents could harmfully impact the environment
and human health. Therefore, various strategies are developing for attracting eco-friendly character to
HPLC. Recently introduced green chromatography concept is based on the 3R rule (Reduce – Replace –
Recycle) implying the HPLC method development governed by the decreased use of acetonitrile labeled
as the most commonly used HPLC solvent and its replacement with ethanol or acetone (1). However,
these greener alternatives are known for their high UV absorbtion cut-off values making them
unsuitable for common UV/VIS detection. As appropriate solvent compatible solution, the use of
Corona Charged Aerosol Detector (CAD) is proposed. CAD is recognized as a universal detector
providing persistent mass sensitive analyte response independent of chemical structure (no need for
UV/VIS chromofores or ionization ability). The detection principle involves the nebulization of
chromatographic mobile phase, the evaporation of aerosol droplets and finally the production of
charged analyte particles (2). Assuming that chromatographic behavior and CAD generated responses
of analytes could be affected by various mobile phase related factors and/or detector parameters
settings, design of experiments (DoE) supported HPLC-CAD method development was performed for
the analysis of antipsychotic drug risperidone in presence of its impurities. By carefully planning the
number and the order of performing experiments, DoE methodology enables investigation of
significance effects of multiple factor effects together with their factor interactions. Different
experimental settings involving variation of organic solvent type and content in range 15-25% (V/V),
mobile phase flow rate (0.50-1.00 mL min -1) and column temperature (25-50 °C) were examined in
accordance with Box-Behnken design and selectivity factor between adjacent peaks on the
chromatogram was measured. The optimal conditions were defined applying mucticriteria decision
making approach by means of Derringer desirability function evaluation. Optimal separations were
achieved using 20% (V/V) of ethanol in mobile phase flowing at 0.6 mL min -1 under 37.5 °C column
temperature, while in case of acetone, optimum comprised 17% (V/V) of organic modifier, 0.8 mL min -1
and 37.5 °C. Finally, eco-friendly character of both methods was rated by Green Analytical Procedure
Index, GAPI (3).Kvalitativna i kvantitativna analiza farmaceutskih supstanci i doziranih oblika predstavlja
činioce od najvećeg značaja za kontrolu kvaliteta u farmaceutskoj industriji. Među dostupnim
analitičkim tehnikama, tečna hromatografija pod visokim pritiskom (HPLC) ističe se svojom visokom
efikasnošć u i robusnošću. Ali, HPLC takođe karakteriše velika potrošnja toksičnih organskih rastvarača
koji se koriste za razvoj metoda i za rutinsku analizu lekova. Ovi rastvarači mogu štetno uticati i na
životnu sredinu i na zdravlje ljudi. Zbog toga se razvijaju različite strategije za obezbeđivanje ekološki
prihvatljivog karaktera HPLC metode. Nedavno predstavljeni koncept zelene hromatografije zasnovan
je na pravilu 3 R (Smanji - Zameni - Recikliraj), što podrazumeva razvoj HPLC metode koji se rukovodi
smanjenom upotrebom acetonitrila kao najčešće korišć enog rastvarača i njegovu zamenu etanolom ili
acetonom (1). Međutim, ove zelenije alternative poznate su po visokim vrednostima za UV apsorpciju,
što ih čini neprikladnim za uobičajenu UV/VIS detekciju. Kao odgovarajuće rešenje kompatibilno sa
pomenutim rastvaračima, predlaže se upotreba detektora naelektrisanja u aerosolu (CAD). CAD je
prepoznat kao univerzalni detektor koji pruža postojan odgovor zavistan od mase analita, a nezavisan
od hemijske strukture (postojanje UV/VIS hromofora ili sposobnosti jonizacije). Princip CAD detekcije
uključuje raspršivanje hromatografske mobilne faze u vidu kapljica aerosola, njihovo isparavanje i
konačno naelektrisavanje dobijenih čestica analita (2). Pretpostavljajuć i da na hromatografsko
ponašanje i CAD generisane odgovore analita mogu uticati različiti faktori povezani sa mobilnom fazom
i/ili parametrima podešavanja detektora, izvršen je razvoj HPLC-CAD metode za analizu antipsihotika
risperidona u prisustvu njegovih nečistoća uz podršku metodologije dizajna eksperimenata (DoE).
Pažljivim planiranjem broja i redosleda izvođenja eksperimenata, DoE omoguć ava ispitivanje značaja
efekata više faktora istovremeno zajedno sa njihovim faktorskim interakcijama. Različite
eksperimentalne postavke koje uključuju varijacije tipa i sadržaja organskog rastvarača u opsegu 15-
25% (V/V), protok mobilne faze (0,50-1,00 mL min -1) i temperaturu kolone (25-50 °C) ispitivane su u
skladu sa Boks-Behnken-ovim dizajnom i faktor selektivnosti između susednih vrhova na
hromatogramu je praćen. Optimalni uslovi definisani su primenom pristupa mutikriterijumskog
odlučivanja baziranog na izračunavanju Derringer-ove funkcije poželjnosti. Optimalna separacija je
postignuta primenom 20% (V/V) etanola u mobilnoj fazi koja teče pri 0,6 mL min -1 i pri temperaturi
kolone od 37,5 °C, dok je u slučaju acetona optimum podrazumevao 17% (V/V) organskog
modifikatora, protok 0,8 mL min -1 i temperaturu 37,5 °C. Konačno, ekološki karakter obe metode
procenjen je na osnovu indeksa zelenih analitičkih procedura, GAPI (3).Drugi naučni simpozijum Saveza farmaceutskih udruženja Srbije sa međunarodnim učešćem, 28. 10. 2021. Beogra
Multicriteria Optimization Methodology in Stability-Indicating Method Development of Cilazapril and Hydrochlorothiazide
Multicriteria optimization methodology was applied in development of UHPLC-UV-MS method for separation of cilazapril, hydrochlorothiazide and their degradation products. This method is also applicable for analysis of cilazapril, hydrochlorothiazide and their degradation products in combined tablet formulation. Prior to method optimization forced degradation studies were conducted. Cilazapril and hydrochlorothiazide were subjected to acidic (0.1, 0.5 and 1.0M HCl), basic (0.1, 0.5 and 1.0M NaOH), thermal (70 degrees C), oxidative (3-30% H2O2) degradation and photodegradation (day light). Cilazapril appeared to be unstable toward acid and base and resulted in formation of cilazaprilat. Hydrochlorothiazide significantly degraded after acid, base and thermal hydrolysis and formed degradation product was 4-amino-6-chlorobenzene-1.3-disulfonamide. For both substances, after oxidative degradation unknown products have arisen. Initial percentage of acetonitrile in mobile phase, final percentage of acetonitrile in mobile phase, time of gradient elution and column temperature were defined as variables to be optimized toward two chromatographic responses by means of central composite design and Derringer's desirability function. The satisfactory chromatographic analysis was achieved on Kinetex C18 (2.6 mu m, 50 x 2.1 mm) column with temperature set at 25 degrees C. The final mobile phase consisted of acetonitrile and 20mM ammonium formate buffer (pH adjusted to 8.5). The flow rate of the mobile phase was 400 mu L min(-1) and it was pumped in a gradient elution mode
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