Microbial Colonization of High Density Polyethylene Garbage Bags

This research aimed to determine the microbial colonization and potential biodegradation of classical high density polyethylene (HDPE) garbage bags in conditions which refl ects its real disposal without preliminary abiotic pretreatment. The HDPE fi lms were buried during 14 weeks in containers with humifi ed soil, activated sludge and its mixture. The colonization of heterotrophic mesophilic aerobic and anaerobic bacteria on the HDPE was monitored. The bacteria and fungi formed biofi lms on the surface of HDPE, but did not have the potential to degrade it since no changes in FTIR spectra of HDPE fi lms were observed. The classical HDPE is primary nontoxic inert material, which is not biodegradable in environmental conditions, what represents a serious ecological problem

Samoprocjena znanja učenika osnovnih škola, nastavnika i ravnatelja o drogama i pitanjima vezanim uz droge

In this research study on a representative sample of Slovenian elementary school students (n = 1527), teachers (n = 163), and head teachers (n = 60), we examined how the responding groups assess their knowledge about drugs, prevention, drug use, and abuse. The data we gathered are similar to the data of a 1998 study carried out in Northern Ireland, entitled ‘Drugs: what young people know’. In our study, students, teachers, and head teachers state that students acquire most of their knowledge about drug use and abuse in school, especially from teachers and school counsellors. However, a high share of the respondents thought that the emphasis was not strong enough. Almost half of the elementary school teachers in Slovenia (46.5%) believe that individual subject syllabuses do not contain enough goals and didactic recommendations encouraging the consideration of drug issues. In addition, international study results demonstrate that, during their undergraduate education, teachers do not acquire enough knowledge about drug issues (Allot and Paxton 2000). Therefore, it is not surprising that 61.5% of Slovenian elementary school teachers have expressed a need for additional training in the field.Na reprezentativnom uzorku učenika (n=1527), nastavnika (n= 163) i ravnatelja (n=60) osnovnih škola, istražili smo kako oni procjenjuju svoje znanje o drogama, prevenciji, konzumaciji i zlouporabi droga. Podaci koji su prikupljeni slični su podacima istraživanja provedenog u Sjevernoj Irskoj pod nazivom ‘Droge: što mladi ljudi znaju’ (1998). U ovom istraživanju, učenici, nastavnici i ravnatelji navode da učenici najviše znanja o konzumaciji i zlouporabi droga stječu u školi, posebno od nastavnika i stručnih suradnika. Međutim, veliki broj sudionika smatra da to nije dovoljno. Gotovo polovica nastavnika osnovnih škola u Sloveniji (46.5%) vjeruje da pojedinačni nastavni planovi i programi predmeta (kurikulumi) ne sadrže dovoljno ciljeva i didaktičkih preporuka koje se bave pitanjima droga. Nadalje, rezultati inozemnih istraživanja pokazuju da, tijekom svojeg preddiplomskog obrazovanja, nastavnici ne stječu dovoljno znanja o pitanjima vezanim u droge (Allot i Paxton, 2000). Stoga ne čudi da je 61.5% nastavnika slovenskih osnovnih škola izrazilo potrebu za dodatnim edukacijama u ovom području

Ansatz zur Bestimmung der Grenzwerte von verunreinigenden Materien im Grundwasser der Republik Kroatien

U radu je prikazan hrvatski pristup za određivanje graničnih vrijednosti tvari i pokazatelja mogućih onečišćenja podzemne vode u vodnom području rijeke Dunav i jadranskom vodnom području. Detaljno su obrazloženi kriteriji za određivanje graničnih vrijednosti, prilagođeni značajkama hidrogeoloških sustava te s njima povezanih ili o njima ovisnih kopnenih i vodenih ekosustava u Republici Hrvatskoj, koji se odnose na referentne standarde kakvoće, odnosno kriterijske vrijednosti, te na pozadinske koncentracije. Analizirane su različite metode procjene pozadinskih koncentracija, koje su korištene u postupku određivanja graničnih vrijednosti u RH, te je razmotrena pouzdanost rezultata dobivenih primjenom različitih metoda na osnovi zajedničkih kriterija. Prikazan je postupak utvrđivanja kriterijskih vrijednosti za važne prijamnike i vidove korištenja podzemne vode, a posebno su analizirani i opisani glavni tipovi graničnih vrijednosti koji se koriste u postupku ocjene kemijskoga stanja ili procjene rizika u pojedinim vodnim područjima. Na primjeru grupiranoga tijela podzemne vode Istočna Slavonija – sliv Drave i Dunava prikazan je postupak određivanja pozadinskih koncentracija i graničnih vrijednosti za odabrane tvari i pokazatelje.The paper presents the Croatian approach to the determination of limit values and indicators of potential groundwater pollution in the Danube River Basin District and Adriatic River Basin District. The criteria for determining limit values are elaborated in detail and adapted to the characteristics of hydrogeological systems and their associated or dependent terrestrial and aquatic ecosystems in the Republic of Croatia, i.e. referent quality standards, such as criteria values and background concentrations. Different methods for assessing background concentrations, which were used in the procedure of limit value determination in the Republic of Croatia, were analysed and the reliability of results obtained by applying different methods based on shared criteria were considered. The procedure of determining the criteria values for important recipients and different groundwater uses were described; the main types of limit values used in the procedures of chemical status assessment and risk assessment in individual river basin districts were analysed and described in particular. The procedure of determining background concentrations and limit values for selected substances and indicators were demonstrated on the example of the groundwater body group Eastern Slavonia – Drava and Danube basin.In der Arbeit wird der kroatische Ansatz zur Bestimmung der Grenzwerte von Materien und des Anzeigens möglicher Verunreinigungen von Grundwasser im Wassergebiet des Flusses Donau und im adriatischen Wassergebiet dargestellt. Die Kriterien zur Bestimmung der Grenzwerte sind genauestens erläutert und den Merkmalen von hydrogeologischen Systemen angepasst, sowie den damit verbundenen oder von ihnen abhängenden Land- und Wasserökosystemen in der Republik Kroatien, die sich auf referierende Qualitätsstandards, beziehungsweise Kriteriumswerte beziehen, ebenso auf Hintergrundkonzentrationen. Analysiert wurden verschiedene Schätzungsmethoden von Hintergrundkonzentrationen, die beim Bestimmungsverfahren der Grenzwerte in der Republik Kroatien benutzt wurden. Außerdem wurde die Verlässlichkeit der Resultate beurteilt, die bei der Anwendung verschiedener Methoden mit gemeinsamen Kriterien erhalten wurden. Dargestellt wurde die Bestimmungsmethode von Kriteriumswerten für wichtige Empfänger und Arten der Nutzung von Grundwasser, besonders analysiert und beschrieben wurden die Typen von Grenzwerten, die beim Verfahren der Beurteilung des chemischen Zustandes oder Schätzung von Risiken in den einzelnen Wassergebieten benutzt werden. Am Beispiel des gruppierten Körpers des Grundwassers Ostslawonien - das Becken von Drau und Donau wurde das Verfahren zur Bestimmung von Hintergrundkonzentrationen und Grenzwerten für ausgesuchte Materien und Indikatoren dargestellt

Depression, Anxiety and Cognitive Dysfunction in Patients with Type 2 Diabetes Mellitus – A Study of Adult Patients with Type 2 Diabetes Mellitus in Osijek, Croatia

im of the study was to determine the rate of depression and anxiety in the patients with diagnosed Type 2 Diabetes mellitus (DM), and also to determine the state of the congnitive functions in patients with Type 2 Diabetes mellitus compared with the control group. Study was designed as a epidemiological cross sectional study, sample consisted of 108 patients, 66 of the patients were diagnosed with Type 2 Diabetes mellitus, and 42 were control group. All of them were interviwed by psychiatrist and tested through clinical interview with Hamilton depression rating scale, Hamilton Anxiety rating scale, Mini mental state examination and questionnaire about sociodemografic data. Results show that group of patients with DM were statistically significat more depressed than the control group of the patients (p=0.035). Pathological anxiety measured by Hamilton Anxiety Rating Scale (HAM-A) appeared in 34 DM patients and 7 of the patients in control group, which is also statistically significant difference (p=0.002). Evaluation of the congnitive status done with Mini Mental State Examination (MMSE showed us tha patients with DM presented more cognitive dysfunctions compared with the control group. We can conclude that the high prevalence of psychiatric disorders in diabetic patients points to the need for greater investment in appropriate diagnostic evaluation of patients that consider mental issues

The availability and use of drugs in Slovenian primary schools and in vicinities close to schools

According to the European Monitoring Centre for Drugs and Drugs Addiction, preventive programmes and interventions should aim to address drug use in specific settings, such as schools. There are no available data about drug use in schools, especially in an international context; therefore, this study attempted to collect data on the availability and use of drugs in schools and in vicinities close to schools, from students attending Slovenian primary schools. The research study consists of a representative sample of students (n = 1527), parents (n = 1259), teachers (n = 163), and head teachers (n = 60) from Slovenia. The data were gathered with a questionnaire, which consisted mainly of opinion and evaluation scales. Findings: The most important finding of this study was that legal and illegal drugs were easily available in Slovenian primary schools and in vicinities close to schools , and students did use them in these areas. Research findings draw attention to the need for teachers and head teachers to pay special attention to drug use in schools and in vicinities close to schools , although they may not initially see it as a problem

Antimicrobial and Resistance Modulatory Activity of Alpinia katsumadai Seed Phenolic Extract, Essential Oil and Post-Distillation Extract

Antimikrobna otpornost patogenih mikroorganizama predstavlja ozbiljan problem u proizvodnji hrane, a naročito zbog rastućeg broja multirezistentnih sojeva. Sve je veća potreba za novim i efikasnim antimikrobnim agensima i modulatorima otpornosti radi prevladavanja ovog problema, pri čemu biljke predstavljaju bogat izvor takvih spojeva. U ovom je radu ispitan antimikrobni učinak fenolnog ekstrakta, eteričnog ulja i destilacijskog ekstrakta sjemenki biljke Alpinia katsumadai, te njihov utjecaj na modulaciju otpornosti sojeva Campylobacter jejuni i Staphylococcus aureus. Ekstrakt sjemenki i postdestilacijski ekstrakt imali su relativno snažan antimikrobni učinak na bakteriju C. jejuni, dok je bakterija S. aureus pokazala veću otpornost. Fenolni ekstrakt, eterično ulje i destilacijski ekstrakt A. katsumadai u kombinaciji sa svim ispitanim antimikrobnim agensima (ciprofloksacin, eritromicin, triklosan, soli žučne kiseline i etidijev bromid) uspješno su modulirali otpornost svih sojeva C. jejuni. Učinak je ekstrakata i eteričnog ulja na bakteriju S. aureus ovisio o bakterijskom soju i primjenjenom antimikrobnom agensu, ali je uspješno smanjena otpornost svih sojeva na soli žučne kiseline. Eterično je ulje sjemenki biljke A. katsumadai potaklo akumulaciju etidijevog bromida unutar bakterijskih stanica, čime je dokazano da se može upotrijebiti kao inhibitor efluksne pumpe bakterija C. jejuni i S. aureus.Antimicrobial resistance of food-related bacterial pathogens is becoming a serious problem, especially after the emergence of multidrug-resistant strains. To overcome this problem, new and effective antimicrobials or resistance modulators are highly needed and plant kingdom represents a valuable source of these compounds. We investigated antimicrobial and resistance modulatory activity of the phenolic extract, essential oil and post-distillation extract of Alpinia katsumadai seeds against Campylobacter jejuni and Staphylococcus aureus. Among the tested plant formulations, A. katsumadai seed phenolic extract and post-distillation extract showed moderate antimicrobial activity against C. jejuni, while S. aureus was more resistant. When evaluating resistance modulatory potential of A. katsumadai phenolic extract, essential oil and post-distillation extract in C. jejuni against ciprofloxacin, erythromycin, triclosan, bile salts and ethidium bromide, plant formulations exhibited modulatory activity in combination with all antimicrobials. Modulation of resistance was more strain- and antimicrobial-specific in S. aureus, but very efficient in the case of reduced resistance to bile salts. Essential oil from A. katsumadai seeds efficiently increased intracellular ethidium bromide accumulation and was thus confirmed as potential inhibitor of efflux pumps in C. jejuni and S. aureus

Natural Products as Antibacterial Agents — Antibacterial Potential and Safety of Post-distillation and Waste Material from Thymus vulgaris L., Lamiaceae

Medicinal plants have a long tradition of use in folk and conventional medicine. In recent years numerous studies confirm various bioactivities of natural products, among them antibacterial activity. Natural antibacterial agents such are essential oils and isolated compounds now represent a notable source for pharmaceutical and food industry and are widely used in cosmetology. They meet standards of \u27green consumerism\u27 together with excellent antibacterial activity. Aromatic plants such is Thymus vulgaris L. are the major sources of essential oils. Thyme essential oil, as well as dominant compounds thymol and carvacrol are generally recognised as safe and have been registered by European Commission for use as flavouring agents in foodstuffs. However, essential oil is present in very low amount (0,8-2,6%) in thyme leaves. Thus, the majority of plant material remains unused after the isolation. Nowadays, the biological potential of various plant waste materials are in focus of numerous studies. These investigations also include the antimicrobial activity considering the fact that waste material extracts represent the valuable source of different phenolic compounds. Regarding all this, the aim of the present study was to determine antibacterial potential of chemically characterised extracts obtained from waste material remaining after the preparation of drug (stems) and isolation of thyme essential oil (deodorised leaves, postdistillation decoction) on selected bacterial strains. Also, in order to determine safety of waste extracts their cytotoxicity was investigated. All extracts were prepared with maceration using 45% or 75% ethanol (EtOH) for 24 h at room temperature (1:10 w/v). Total phenolic compounds and flavonoids were determined spectrophotometrically. Extracts were chemically characterized by HPLC/DAD analysis. Antibacerial testing was done with broth dilution method against several bacterial strains (Staphylococcus aureus, Bacillus cereus, Salmonella infantis, Escherichia coli and Campylobacter jejuni). Cytotoxicity and cytoprotection studies were performed by XTT assay. Result of HPLC analysis showed that investigated extracts, especially those obtained from deodorised leaves represent a valuable source of rosmarinic acid and luteolin 7-O-glucuronide. Antibacterial testing indicated that all waste material extracts, except the extract T2, possess similar or even stronger bacteriostatic activity than T1. No cytotoxicity nor cytoprotection were determined. In conclusion, results of this study confirmed antibacterial potential investigated thyme extracts. High concentrations of rosmarinic acid and luteolin 7-O-glucuronide, which both have numerous pharmacological activities, were determined. This indicates that thyme postdistillation waste material extracts could be used for isolation of dominant compounds or as addities in pharmaceutical and food industry

(-)-α-Pinene reduces quorum sensing and Campylobacter jejuni colonization in broiler chickens

Campylobacter jejuni is one of the most prevalent causes of bacterial gastroenteritis worldwide, and it is largely associated with consumption of contaminated poultry. Current Campylobacter control measures at the poultry production level remain insufficient, and hence there is the need for alternative control strategies. We evaluated the potential of the monoterpene (-)-α-pinene for control of C. jejuni in poultry. The antibacterial and resistance-modulatory activities of (-)-α-pinene were also determined against 57 C. jejuni strains. In addition, the anti-quorum-sensing activity of (-)-α-pinene against C. jejuni NCTC 11168 was determined for three subinhibitory concentrations (125, 62.5, 31.25 mg/L) over three incubation times using an autoinducer-2 bioassay based on Vibrio harveyi BB170 bioluminescence measurements. The effects of a subinhibitory concentration of (-)-α-pinene (250 mg/L) on survival of C. jejuni, and in combination with enrofloxacin on fluoroquinolone resistance development in C. jejuni, were determined in a broiler chicken model, by addition of (-)-α-pinene to the broiler water supply. The reduction of C. jejuni numbers by (-)-α-pinene was further determined in broiler chickens that were colonized with either fluoroquinolone-susceptible or -resistant strains, by direct gavage treatment. We observed weak in vitro antimicrobial activity for (-)-α-pinene alone (MIC \u3e500 mg/L), but strong potentiating effects on antibiotics erythromycin and ciprofloxacin against different Campylobacter strains (\u3e512 fold change). After 24 h of treatment of C. jejuni with (-)-α-pinene, its quorum-sensing signaling was reduced by \u3e80% compared to the untreated control. When given in the drinking water, (-)-α-pinene did not show any significant inhibitory effects on the level of C. jejuni in the colonized chickens, and did not reduce fluoroquinolone resistance development in combination with enrofloxacin. Conversely, when (-)-α-pinene was administered by direct gavage, it significantly reduced the number of fluoroquinolone susceptible C. jejuni in the colonized broiler chickens. These results demonstrate that (-)-α-pinene modulates quorum-sensing in Campylobacter, potentiates antibiotics against different Campylobacter strains, and reduces Campylobacter colonization in broiler chickens

Fabrication of Polycaprolactone-Based Polyurethanes with Enhanced Thermal Stability

The benefit of being acquainted with thermal properties, especially the thermal stability of polyurethanes (PU), and simplified methods for their improvement is manifold. Considering this, the effect of embedding different amounts of unmodified and surface-modified TiO2 nanoparticles (NPs) within PU, based on polycaprolactone (PCL) and Boltorn® aliphatic hyperbranched polyester, on PU properties was investigated. Results obtained via scanning electron microscopy, swelling measurements, mechanical tests and thermogravimetric analysis revealed that TiO2 NPs can be primarily applied to improve the thermal performance of PU. Through surface modification of TiO2 NPs with an amphiphilic gallic acid ester containing a C12 long alkyl chain (lauryl gallate), the impact on thermal stability of PU was greater due to the better dispersion of modified TiO2 NPs in the PU matrix compared to the unmodified ones. Also, the distinct shape of DTG peaks of the composite prepared using modified TiO2 NPs indicates that applied nano-filler is mostly embedded in soft segments of PU, leading to the delay in thermal degradation of PCL, simultaneously improving the overall thermal stability of PU. In order to further explore the thermal degradation process of the prepared composites and prove the dominant role of incorporated TiO2 NPs in the course of thermal stability of PU, various iso-conversional model-free methods were applied. The evaluated apparent activation energy of the thermal degradation reaction at different conversions clearly confirmed the positive impact of TiO2 NPs on the thermal stability and aging resistance of PU