Quantification of dynamic excitation potential of pedestrian population crossing footbridges

Due to their slenderness, many modern footbridges may vibrate significantly under pedestrian traffic. Consequently, the vibration serviceability of these structures under human-induced dynamic loading is becoming their governing design criterion. Many current vibration serviceability design guidelines, concerned with prediction of the vibration in the vertical direction, estimate a single response level that corresponds to an "average" person crossing the bridge with the step frequency that matches a footbridge natural frequency. However, different pedestrians have different dynamic excitation potential, and therefore could generate significantly different vibration response of the bridge structure. This paper aims to quantify this potential by estimating the range of structural vibrations (in the vertical direction) that could be induced by different individuals and the probability of occurrence of any particular vibration level. This is done by introducing the inter- and intra-subject variability in the walking force modelling. The former term refers to inability of a pedestrian to induce an exactly the same force with each step while the latter refers to different forces (in terms of their magnitude, frequency and crossing speed) induced by different people. Both types of variability are modelled using the appropriate probability density functions. The probability distributions were then implemented into a framework procedure for vibration response prediction under a single person excitation. Instead of a single response value obtained using currently available design guidelines, this new framework yields a range of possible acceleration responses induced by different people and a distribution function for these responses. The acceleration ranges estimated are then compared with experimental data from two real-life footbridges. The substantial differences in the dynamic response induced by different people are obtained in both the numerical and the experimental results presented. These results therefore confirm huge variability in different people's dynamic potential to excite the structure. The proposed approach for quantifying this variability could be used as a sound basis for development of new probability-based vibration serviceability assessment procedures for pedestrian bridges

Vibration serviceability of footbridges under human-induced excitation : a literature review

Increasing strength of new structural materials and longer spans of new footbridges, accompanied with aesthetic requirements for greater slenderness, are resulting in more lively footbridge structures. In the past few years this issue attracted great public attention. The excessive lateral sway motion caused by crowd walking across the infamous Millennium Bridge in London is the prime example of the vibration serviceability problem of footbridges. In principle, consideration of footbridge vibration serviceability requires a characterisation of the vibration source, path and receiver. This paper is the most comprehensive review published to date of about 200 references which deal with these three key issues. The literature survey identified humans as the most important source of vibration for footbridges. However, modelling of the crowd-induced dynamic force is not clearly defined yet, despite some serious attempts to tackle this issue in the last few years. The vibration path is the mass, damping and stiffness of the footbridge. Of these, damping is the most uncertain but extremely important parameter as the resonant behaviour tends to govern vibration serviceability of footbridges. A typical receiver of footbridge vibrations is a pedestrian who is quite often the source of vibrations as well. Many scales for rating the human perception of vibrations have been found in the published literature. However, few are applicable to footbridges because a receiver is not stationary but is actually moving across the vibrating structure. During footbridge vibration, especially under crowd load, it seems that some form of human–structure interaction occurs. The problem of influence of walking people on footbridge vibration properties, such as the natural frequency and damping is not well understood, let alone quantified. Finally, there is not a single national or international design guidance which covers all aspects of the problem comprehensively and some form of their combination with other published information is prudent when designing major footbridge structures. The overdue update of the current codes to reflect the recent research achievements is a great challenge for the next 5–10 years

Нови приступи у третману хроничних бактеријских и гљивичних инфекција

Hronične infekcije izazvane bakterijama i gljivama predstavljaju rastući globalni zdravstveni problem, posebno u svetlu svakodnevnog povećanja broja imunokompromitovanih osoba (HIV, dijabetes), onkoloških pacijenata, autoimunskih oboljenja (cistična fibroza, bronhiektaze), i pacijenata na kortikosterioidnoj terapiji ili sa transplantacijom organa. Ovakve infekcije su po svojoj prirodi najčešće polimikrobne i karakterišu se prisustvom različitih vrsta bakterija ili bakterija i gljiva, koji koegzistiraju u vidu visoko uređenih zajednica poznatih kao biofilm.1 Hronične infekcije se čak u više od 80% slučajeva karakterišu postojanjem biofilmova, unutar kojih su ćelije patogenih mikroorganizama zaštićene od dejstva antimikrobnih terapeutika i imunskog sistema, dok im je virulentnost dosta povećana, što značajno umanjuje efikasnost lečenja konvencionalnim antimikrobnim lekovima. Dodatni izazov u kliničkoj praksi predstavljaju širenje antimikrobne rezistencije i ograničen broj klasa antimikrobnih lekova, kao i stagnacija farmaceutske industrije u razvoju inovativnih antibiotika sa drugačijim mehanizmom delovanja, a posebno antimikotika.1,2 Stoga, kontrola formiranja biofilma kao rezervoara infektivnih agenasa, i ekspresije faktora virulencije patogena koji vode ka narušavanju integriteta inficiranih tkiva domaćina predstavljaju jedan od ključnih koraka za efikasan tretman hroničnih infekcija. Dodatno, primena inhibitora međućelijske komunikacije, terapija bakteriofagima, jačanje odbrambenog kapaciteta imunskog sistema, kao i manipulacija celokupnim mikrobiomom predstavljaju samo neke od najnovijih pristupa u lečenju hroničnih infekcijaХроничне инфекције изазване бактеријама и гљивама представљају растући глобални здравствени проблем, посебно у светлу свакодневног повећања броја имунокомпромитованих особа (ХИВ, дијабетес), онколошких пацијената, аутоимунских обољења (цистична фиброза, бронхиектазе), и пацијената на кортикостериоидној терапији или са трансплантацијом органа. Овакве инфекције су по својој природи најчешће полимикробне и карактеришу се присуством различитих врста бактерија или бактерија и гљива, који коегзистирају у виду високо уређених заједница познатих као биофилм.1 Хроничне инфекције се чак у више од 80% случајева карактеришу постојањем биофилмова, унутар којих су ћелије патогених микроорганизама заштићене од дејства антимикробних терапеутика и имунског система, док им је вирулентност доста повећана, што значајно умањује ефикасност лечења конвенционалним антимикробним лековима. Додатни изазов у клиничкој пракси представљају ширење антимикробне резистенције и ограничен број класа антимикробних лекова, као и стагнација фармацеутске индустрије у развоју иновативних антибиотика са другачијим механизмом деловања, а посебно антимикотика.1,2 Стога, контрола формирања биофилма као резервоара инфективних агенаса, и експресије фактора вируленције патогена који воде ка нарушавању интегритета инфицираних ткива домаћина представљају један од кључних корака за ефикасан третман хроничних инфекција. Додатно, примена инхибитора међућелијске комуникације, терапија бактериофагима, јачање одбрамбеног капацитета имунског система, као и манипулација целокупним микробиомом представљају само неке од најновијих приступа у лечењу хроничних инфекцијаKnjiga sažetaka: Treći Kongres biologa Srbije, Zlatibor, Srbija 21 - 25. 9. 2022

Unravelling Anti-Melanogenic Potency of Edible Mushrooms Laetiporus sulphureus and Agaricus silvaticus In Vivo Using the Zebrafish Model

Severe drawbacks associated with the topical use of depigmenting agents in treatments of skin hyperigmentations impose a great demand for novel, effective, and safe melanogenesis inhibitors. Edible and medicinal mushrooms, known for numerous health-promoting properties, represent a rich reservoir of anti-melanogenic compounds, with the potential to be applied in preventing excessive skin pigmentation. Herein, using zebrafish (Danio rerio) as a preclinical animal model, we have demonstrated that ethanol extract of Laetiporus sulphureus (LSE) and Agaricus silvaticus (ASE) are not toxic at high doses up to 400-500 mu g/mL while effectively inhibit melanogenesis in a dose-dependent manner. At depigmenting doses, the explored extracts showed no adverse effects on zebrafish embryos melanocytes. Even more, they did not provoke inflammation or neutropenia when applied at the highest dose ensuring almost complete the cells depigmentation. Since LSE and ASE have demonstrated significantly higher the therapeutic potential than kojic acid and hydroquinone, two well-known depigmenting agents, overall results of this study strongly suggest that the explored mushrooms extracts could be used as efficient and safe topical agents in treatments of skin hyperpigmentation disorders

Neovascularization Effects of Carbon Monoxide Releasing Drugs Chemisorbed on Coscinodiscus Diatoms Carriers Characterized by Spectromicroscopy Imaging

Silica microparticles made of diatomaceous earth have become particularly attractive materials for designing drug delivery systems. In order to investigate the use of natural diatoms as drug scaffolds for carbon monoxide releasing molecules (CORMs), we evaluated the chemisorption of the cis-[Re(CO)(2)Br-4](2-) complex (ReCORM-2) and its vitamin B-12 derivative (B-12-ReCORM-2) on Coscinodiscus frustules by 3D FT-IR spectroscopic imaging, and the drugs' neovascularization effects in vivo in the zebrafish (Danio rerio) model. By mapping the symmetric Re-C equivalent to O upsilon(CO) stretching vibration of the CORMs in the 2000 cm(-1) region, we found that the drugs are mostly localized at the girdle band of the diatom frustule. Both ReCORM-2 and B-12-ReCORM-2 retain their CO-releasing ability when chemisorbed on the diatoms. When applied in vivo at doses gt = 25 mu M, the molecules markedly reduced intersegmental and subintestinal vessels development in zebrafish, revealing high anti-angiogenic potential. In addition, diatom frustules did not provoke any toxic in vivo response in the zebrafish embryos, including inflammation. Overall, our results indicate that: (1) CORMs chemisorbed on diatom frustules retain their CO-releasing abilities; (2) both CO-releasing molecules show a concentration-dependent effect on the neovascularization in developing zebrafish; (3) silicate frustules are not toxic and could be used as CORMs drug carriers

Od erektilne disfunkcije do subependimoma mozga: prikaz slučaja

Endocrinopathies are relatively rare causes of erectile dysfunction. Cases of hyperprolactinemia and pituitary adenomas have been previously reported. We present a clinical case of a 27-year-old male with suspected infertility and recent symptoms of erectile dysfunction. Additional radiological and endocrinologic workup revealed underlying subependymoma, which was expanding in the sellar and suprasellar regions, causing pressure against the pituitary gland. The resulting endocrine disorder caused problems that were subjectively at first manifested mainly as erectile dysfunction. The case is an educative example pointing to the need of taking possible intracranial lesions in consideration when starting workup in a patient presenting with erectile dysfunction. It may be of broad clinical interest not only for endocrinologists but also for practitioners in various fields.Endokrinopatije su relativno rijetki uzroci erektilne disfunkcije. Prethodno su opisani slučajevi hiperprolaktinemije i adenoma hipofize. Mi prikazujemo klinički slučaj 27-godišnjeg muškarca sa sumnjom na neplodnost i nedavnim simptomima erektilne disfunkcije. Dodatna radiološka i endokrinološka obrada otkrila je u podlozi subependimom s ekspanzijom u selarnoj i supraselarnoj regiji, s kompresijom na hipofizu. Posljedični endokrini poremećaj uzrokovao je probleme koji su se prvobitno subjektivno manifestirali pretežno kao erektilna disfunkcija. Slučaj je edukativni primjer koji upućuje na to da je kod bolesnika koji se prezentira s erektilnom disfunkcijom pri započinjanju obrade potrebno uzeti u obzir moguće intrakranijske lezije. Slučaj bi mogao biti klinički zanimljiv ne samo za endokrinologe, nego i za praktičare iz drugih stručnih područja

RELIABILITY ANALYSIS OF DIFFERENT RCIED ACTIVATION SIGNAL RESPONSIVE JAMMING TECHNIQUES AND THEIR COMPARISON TO ACTIVE JAMMING

In this paper we compared the time required for the successful jamming of remote controlled improvised explosive devices activation using active and responsive jamming methods. As a representative of active jamming method we analyzed jamming signal generation using frequency sweep. For the analysis of the possible activating signal presence based on responsive jamming procedures we first supposed Fast Fourier Transform (FFT) implementation and compared its analysis rate to the rate of sweep jamming. Taking into account the current technology state, it is proved that the time required to achieve the successful jamming relied on FFT analysis may be less than in the case of active sweep jamming. After that we considered pros and cons for energy detector and matched filter detector implementation in responsive jamming. For these two detector types it is shown how to determine the number of analysis blocks to achieve approximately the same number of collected samples as in the case of FFT implementation, starting from the probabilities of false detection and miss of detection

Supplementary data for article: Senerovic, L.; Zivkovic, M. D.; Veselinovic, A.; Pavic, A.; Djuran, M. I.; Rajkovic, S.; Nikodinovic-Runic, J. Synthesis and Evaluation of Series of Diazine-Bridged Dinuclear Platinum(II) Complexes through in Vitro Toxicity and Molecular Modeling: Correlation between Structure and Activity of Pt(II) Complexes. Journal of Medicinal Chemistry 2015, 58 (3), 1442–1451. https://doi.org/10.1021/jm5017686

Supporting information for: [https://doi.org/10.1021/jm5017686]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1659

The assessment of attitudes volunteering representation in the region of the city of Vinkovci secondary school population

Ciljevi ovoga istraživanja usmjereni su na procjenu uvjerenja i stavova učenika dvaju srednjih škola s područja grada Vinkovaca o volontiranju, uključenost učenika u volontiranje i zadovoljstvo učenika volontiranjem. Stratificirani uzorak ispitanika čine učenici dviju srednjih škola: Zdravstvena i veterinarska škola „dr. Andrija Štampar“ (50 ispitanika) i Gimnazija „Matija Antun Reljković“ (50 ispitanika). Unutar svakoga stratuma ispitanici su iz ukupne populacije bili uključeni metodom slučajnih brojeva. Najveći broj ispitanika volontirao je pri crkvi, a najmanje za potrebe političkih stranaka. Uočeni su u obje škole pozitivni stavovi o volontiranju, pri čemu od ukupnoga broja ispitanih, njih 21% redovito volontira, što je 11,5% više od prosjeka volontiranja u općoj populaciji u Hrvatskoj koji iznosi 9,5%. Nadalje, prosudbe o volontiranju glede osobnih oplemenjivanja također su pozitivne. Rezultatima svojeg volonterskoga rada značajno su zadovoljniji ispitanici zdravstvene škole. Također, starija srednjoškolska populacija ima pozitivne stavove o volontiranju i učestalije volontira od ukupnoga prosjeka volontiranja u Hrvatskoj. Istraživanje ukazuje na stav učenika o nedovoljnom promicanju i poštivanju volontiranja u zajednici. Uočeno je da su u gimnaziji prisutni pojedinci koji su dublje upućeni u problematiku volontiranja. Ispitanici iz zdravstvene škole izrazitije podržavaju prijedloge o pokrivanju troškova prijevoza i doručka, kao i stručno osposobljavanje organizacija za prihvat i rad s volonterima. Rezultati su uspoređeni s rezultatima srodnih istraživanja u Dubrovniku i Zagrebu. Istraživanje predstavlja doprinos razumijevanju i usmjeravanje politike i kulture volontiranja u Hrvatskoj.The aims of this research are to evaluate the beliefs and attitudes on volunteering (involvement, satisfaction) of students from two secondary schools in the area of the city of Vinkovci. The stratified sample of students is made up of two secondary schools: Dr Andrija Stampar’s (50 respondents) and Matija Antun Reljkovic’s High School (50 respondents). Within each stratum, respondents from the total population were included in the random number method. The largest number of respondents volunteered with the church, and in the least for the needs of political parties. There are positive attitudes on volunteering in both schools, of which 21% regular volunteers, which is 11.5% more than the average of volunteering in the general population in Croatia, which is 9.5%. Furthermore, judgments on volunteering for personal improvement are also positive. The health school respondents are significantly more satisfied with the results of their volunteer work. Also, an older high school population has positive attitudes on volunteering and volunteers more than the overall average of volunteering in Croatia. The research points to the attitudes of students on insufficient promotion and respect for community volunteering. It was noted that there were individuals in the gymnasium who were deeper in volunteering. Health school respondents strongly supported proposals to cover transportation and eating costs as well as vocational training of volunteer organizations and volunteers. The results were compared with the results of related researches in Dubrovnik and Zagreb. Research is a contribution to understanding and guiding the politics and culture of volunteering in Croatia

Cardiovascular risk factors and visiting nurse intervention - evaluation of a Croatian survey and intervention model: the CroHort study [Kardiovaskularni rizični čimbenici i intervencija patronažnih sestara - evaluacija istraživanja u Hrvatskoj i intervencijski model: CroHort studija]

The aim of this study is to identify factors that influence the success of the implementation of the primary and secondary prevention programs in Croatia by the visiting/community services. Two main sources of information were used: reports about regular visiting nurse services in Croatia and research about visiting nurse participation in the Croatian Adult Health Cohort Study (CroHort) 2008. Out of the total number 9,070 respondents who participated in CAHS 2003 survey, during CroHort 2008 program 3,229 (35.6%) participants were re-interviewed. The qualitative analysis was done with a sample of 34 visiting nurses, which participated in the CroHort 2008. Results show that there are three key problems which limit preventive programs: inability of the health care system to recognize the importance of the primary prevention; visiting nurses' lack capacity to implement prevention and populations' lack of motivation and education