815 research outputs found

    Coordinated TSO and DSO network development plan on the islands of Cres and Lošinj

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    The paper presents an example of coordinated transmission and distribution network planning based on analyses conducted as part of the study on long term distribution network development plan for islands of Cres and Lošinj in Croatia. The observed area of two large and several smaller islands is supplied with electricity by one long radial 110 kV TSO owned line and parallel radial 35 kV DSO owned line. Due to transmission capacity of 35 kV line limited to 40% of the area peak demand, which is highly conditioned by tourism, the (N-1) criteria is not complied with in case of unavailability of 110 kV line during the two-month period in summer high season. Construction of the second 110 kV line as a common solution is extremely costly, due to necessity of laying down several kilometres of submarine cables. The paper provides the cost benefit analyses of this basic scenario and other possible alternative scenarios, including also investments in DSO network, to determine the most cost-effective solution. Due to the values of the demands and networks lengths, the presented example is close to a worst case scenario concerning the reliability of supply requirement, requesting thus some atypical distribution network analyses, elements and even conducted field tests of operation. The results clearly show that coordination of TSO and DSO planning is beneficiary concerning efficiency of investments in the networks. However, further analyses are recommended presuming contribution to satisfying the (N-1) criteria by use of non-traditional (“non-network” or “third party”) solutions

    Treatment of benign prostatic hyperplasia by natural drugs

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    Benign prostatic hyperplasia (BPH) is one of the most common urinary diseases affecting men, generally after the age of 50. The prevalence of this multifactorial disease increases with age. With aging, the plasma level of testosterone decreases, as well as the testosterone/estrogen ratio, resulting in increased estrogen activity, which may facilitate the hyperplasia of the prostate cells. Another theory focuses on dihydrotestosterone (DHT) and the activity of the enzyme 5α-reductase, which converts testosterone to DHT. In older men, the activity of this enzyme increases, leading to a decreased testosterone/DHT ratio. DHT may promote prostate cell growth, resulting in hyperplasia. Some medicinal plants and their compounds act by modulating this enzyme, and have the above-mentioned targets. This review focuses on herbal drugs that are most widely used in the treatment of BPH, including pumpkin seed, willow herb, tomato, maritime pine bark, Pygeum africanum bark, rye pollen, saw palmetto fruit, and nettle root, highlighting the latest results of preclinical and clinical studies, as well as safety issues. In addition, the pharmaceutical care and other therapeutic options of BPH, including pharmacotherapy and surgical options, are discussed, summarizing and comparing the advantages and disadvantages of each therapy

    Določanje benzodiazepinov v urinu preko benzofenonskih derivatov z uporabo tekočinske kromatografije sklopljene s tandemsko masno spektrometrijo

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    The aim of this study was to validate a new method for determining benzodiazepines in urine via their benzophenone derivatives, based on liquid chromatography-tandem mass spectrometry (LC-MS/MS). Selected benzodiazepines were analysed after acid hydrolysis of urine and extraction by ethyl acetate in the presence of an internal standard. Samples were analysed using electrospray ionization LC-MS/MS in a multiple reaction monitoring mode. The chromatographic run time on a reversed phase C18 analytical column was set for 9 min. This method was validated in 21 patients receiving methadone. Benzodiazepines intake was established in two out of three patients. LC-MS/MS results were also compared with the rapid immunoassay and the methods showed good agreement. However, in three cases benzodiazepines were detected by LC-MS/MS, but not by the immunoassay. The sensitivity of the developed LC-MS/MS method is comparable to or even higher than of previously reported methods, which makes it suitable as a confi rmatory method.Razvili smo selektivno in občutljivo metodo za določanje nekaterih benzodiazepinov v urinu preko določanja njihovih benzofenonov. Metoda temelji na tekočinski kromatografi ji, sklopljeni s tandemsko masno spektrometrijo (LC-MS/MS). Izbrane benzodiazepine smo analizirali po kisli hidrolizi urinskih vzorcev in ekstrakciji z etilacetatom v prisotnosti internega standarda. Vzorce smo analizirali z elektrorazprševalno ionizacijo z MRM načinom detekcije. Čas kromatografske ločbe na reverznofazni (C18) analitski koloni je bil 9 min. Metoda je bila validirana in preizkušena na 21 pacientih, ki so prejemali metadonsko terapijo. Pri dveh tretjinah primerov je bil vnos benzodiazepinov tudi potrjen. Vzorce smo testirali tudi s hitro imunokemijsko metodo in rezultate primerjali z rezultati pridobljenimi z LC-MS/MS metodo. Ugotovili smo dobro ujemanje med rezultati pridobljenimi z obe a metodama. Kljub temu smo v treh primerih določili prisotnost benzodiazepinov z LC-MS/MS metodo, ki je z imunokemijsko metodo nismo. Občutljivost razvite metode je primerljiva ali celo boljša od predhodno opisanih metod, zato jo lahko uporabimo kot potrditveno metodo
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