Regional pulmonary vasoreactivity, with special reference to nitric oxide, prostacyclin and body posture

The primary aim of the study was to investigate possible mechanisms behind the improved arterial oxygenation in ventilator-treated patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) when turned into prone position. A secondary aim was to discover new knowledge of possible importance for treatment of patients with oxygenation problems in intensive care and during anesthesia. Previous work have described a dominant blood flow in dorsal lung regions regardless of posture and a better matching of ventilation (V) and perfusion (Q) in prone vs supine posture. Perfusion and also V/Q ratios are more homogeneous in prone than in supine position. The hypothesis of the study was that differences in regional pulmonary vasoreactivity to the endogenous vasodilators nitric oxide (NO) and prostacyclin (PGI2) may explain the improved gas exchange in severe lung disease during ventilator treatment in prone position. Regional pulmonary vasoreactivity to NO and PGI2, as well as effects of posture on distribution of regional pulmonary blood flow, were investigated in isolated human and porcine lung tissue and pulmonary arteries in vitro and in volunteers and patients in vivo. Presently it was shown that expression of mRNA for endothelial NO synthase (eNOS) was higher in dorsal compared to ventral human lung regions. Ca2+-dependent NOS activity was higher in dorsal than in ventral regions of both human and porcine lungs. Relaxation of porcine pulmonary arteries in vitro by acetylcholine and bradykinin, endothelial-dependent vasodilators, acting via the NO / cGMP pathway was more potent in vessels from dorsal than from ventral lung regions. Furthermore, NOS inhibition by infusion of NG-monomethyl-L-arginine (L-NMMA) redistributed blood flow from dorsal to ventral lung regions in healthy volunteers in supine position. Altogether these results strongly suggest a role for endogenous NO in regulation of regional pulmonary perfusion. Inhalation of iloprost, a synthetic PGI2 analogue, decreased arterial oxygen tension in healthy volunteers. Pulmonary perfusion was redistributed towards dependent lung regions in both supine and prone, whereas ventilation was redirected towards non-dependent lung regions in supine position, indicating increased mismatch of ventilation and perfusion. Prostaglandin synthesis inhibition by the non-selective cyclooxygenase (COX) inhibitor diclofenac did not affect pulmonary perfusion distribution or oxygenation in healthy subjects. Patients subjected to left side thoracic surgery in lateral decubitus position with one-lung ventilation (OLV) were treated with non-selective COX-inhibition by diclofenac infusion. They had significantly lower shunt and better oxygenation as measured by alveolo-arterial oxygen difference than patients receiving placebo. The results suggest that a COX-related arachidonic acid metabolite attenuates pulmonary hypoxic vasoconstriction. In conclusion the results strongly suggest a role for endogenous NO in regulation of regional pulmonary perfusion. PGI2 is likely not involved in regulation of regional pulmonary perfusion during normoxia whereas it may be of importance during hypoxia. The present results may become of importance for patients with oxygenation problems in intensive care as well as during one-lung ventilation for thoracic surgery

Oil removal from water by filtration

Oil-contaminated water is most commonly treated with sorbent materials. In this experimental study, a fibrous sorbent material Fibroil was used. The experiment was carried out with tap water and clarified stormwater. It was determined that the retention of contaminants is worse at high fow rates, which reduces the efficiency of treatment. Sorbent materials retain suspended solids and reduce water turbidity; thus, the water must be clarified and pretreated before it is supplied to the sorption fillings. For the efficient use of sorbent material properties, the concentration of suspended solids in water supplied to the filter must be below 20 mg/L, while water turbidity must be below 15 NTU and the flow rate must be below 20 m/h. If the pressure loss in the sorption filler increases to 25 cm, it can be predicted that the oil concentration after treatment would exceed permissible environmental requirements (5 mg/L). The derived sorption and hydraulic properties of the material can be used to evaluate the efficiency of existing operative stormwater treatment plants as well as to design new facilities

Determination of organic matter by UV absorption in the ground water

Organic matter in drinking water is determined by applying indirect determination methods used for quantitative measurements such as total organic carbon (TOC), chemical oxygen demand (COD), and biochemical oxygen demand (BOD). These analyses require expensive devices, harmful chemical reagents, and are time consuming. Standard water quality tests are inconvenient during start-up or reconstruction of drinking water treatment plants as samples need to be transported to a laboratory and no on-line measurements on plant performing efficiency are available. For practical purposes, less sophisticated and faster methods to determine organic matter are required. One of the methods could be ultraviolet absorption of water at 254 nm wavelength (UV254). It is a technically simple and fast method for determining natural organic matter, requiring neither expensive measurement equipment nor chemical reagents. The present article aims at investigating the possibilities of practical applications of UV254 method to determine the concentration of natural organic matter in ground water. The research proved good correlation between TOC and UV254, as well as between CODMn and UV254. The outcomes of the research indicate that UV254method can be successfully applied to determine natural organic matter concentrations in ground water. Article in English. Organinių medžiagų požeminiame vandenyje nustatymas taikant UV bangų absorbciją Santrauka. Organinės medžiagos požeminiame vandenyje nustatomos netiesioginiais kiekybiniais bendrosios organinės anglies (BOA), cheminio deguonies suvartojimo (ChDSMn) ir biocheminio deguonies suvartojimo (BDS) metodais. Šioms analitėms nustatyti būtini brangūs prietaisai, kenksmingi cheminiai reagentai, tyrimai ilgai trunka. Diegiant naujus geriamojo vandens gerinimo įrenginius ir atliekant įrenginių paleidimo, derinimo bei eksploatavimo proceso efektyvumo vertinimą, minėtuosius geriamojo vandens tyrimus nepatogu ir brangu atlikti, todėl šiais atvejais reikia paprastesnio ir greitesnio organinių medžiagų nustatymo metodo. 254 nm bangos ilgio (UV254) ultravioletinių spindulių absorbcija yra techniškai paprastas, spartus organinių junginių koncentracijų nustatymo metodas, jį taikant nebūtina brangi tyrimų įranga bei cheminiai reagentai. Šio darbo tikslas buvo ištirti UV254 metodo tinkamumą organinių junginių koncentracijoms nustatyti požeminiame vandenyje. Atlikus tyrimus apibrėžtos priklausomybės tarp BOA ir UV254 bei tarp ChDSMn ir UV254. Remiantis tyrimų rezultatais galima teigti, kad ultravioletinių spindulių absorbcijos metodas gali būti sėkmingai taikomas organinių junginių koncentracijoms požeminiame vandenyje nustatyti. Reikšminiai žodžiai: požeminis vanduo, organinės medžiagos, ultravioletinių spindulių absorbcija, UV, koaguliacij

Respiratory Monitoring by Porphyrin Modified Quartz Crystal Microbalance Sensors

A respiratory monitoring system based on a quartz crystal microbalance (QCM) sensor with a functional film was designed and investigated. Porphyrins 5,10,15,20-tetrakis-(4-sulfophenyl)-21H,23H-porphine (TSPP) and 5,10,15,20-tetrakis-(4-sulfophenyl)-21H, 23H-porphine manganese (III) chloride (MnTSPP) used as sensitive elements were assembled with a poly(diallyldimethyl ammonium chloride) (PDDA). Films were deposited on the QCM resonators using layer-by-layer method in order to develop the sensor. The developed system, in which the sensor response reflects lung movements, was able to track human respiration providing respiratory rate (RR) and respiratory pattern (RP). The sensor system was tested on healthy volunteers to compare RPs and calculate RRs. The operation principle of the proposed system is based on the fast adsorption/desorption behavior of water originated from human breath into the sensor films deposited on the QCM electrode

Advances in Electronic-Nose Technologies Developed for Biomedical Applications

The research and development of new electronic-nose applications in the biomedical field has accelerated at a phenomenal rate over the past 25 years. Many innovative e-nose technologies have provided solutions and applications to a wide variety of complex biomedical and healthcare problems. The purposes of this review are to present a comprehensive analysis of past and recent biomedical research findings and developments of electronic-nose sensor technologies, and to identify current and future potential e-nose applications that will continue to advance the effectiveness and efficiency of biomedical treatments and healthcare services for many years. An abundance of electronic-nose applications has been developed for a variety of healthcare sectors including diagnostics, immunology, pathology, patient recovery, pharmacology, physical therapy, physiology, preventative medicine, remote healthcare, and wound and graft healing. Specific biomedical e-nose applications range from uses in biochemical testing, blood-compatibility evaluations, disease diagnoses, and drug delivery to monitoring of metabolic levels, organ dysfunctions, and patient conditions through telemedicine. This paper summarizes the major electronic-nose technologies developed for healthcare and biomedical applications since the late 1980s when electronic aroma detection technologies were first recognized to be potentially useful in providing effective solutions to problems in the healthcare industry

Stormwater treatment plant conception

Римейка М. Концепция очистных сооружений ливневых стоковThe practice of urban stormwater management has until recently focused only on drainage and flood control. Yet more concern should be taken to reduce pollu-tion loads on water recipients by implementing source control management, on-site treatment and building stormwater pollution control facilities. Overview and basic principals of stormwater quality management are presented in the article. Summary presents the results for the evaluation of stormwater pollution removal

Analysis of water consumption changes during two decades

Water consumption depends on the consumers’ habits, industrial companies and the nature of the activity, as well as on public users. Water consumption in Lithuania has decreased by more than three times over the past two decades. This was influenced by the changed consumers’ habits, implemented water metering and increased water prices. But it has been analyzed little, how the dynamics of water consumption has been changing. This article examines the dynamics of water consumption variation over 20 years in one of Vilnius district. Variations of water consumption are analyzed in the article and the obtained results are compared with the parameters in the legal acts. Water consumption per night was analyzed in the article also, as these values could be fast and reliable assessment of water losses in network. The analysis of night water consumption was conducted and the recommended norm of night water consumption indicated

The efficiency of removing organic matters and colour from groudwater using coaguliants

Organic matter in drinking water must be removed as it causes many problems such as changes in colour, taste, odour and lower quality of water. During the chlorination process, humic acid reacts with chlorine and produce toxic disinfection-by-products. The study has used three coagulants: polialuminium oxychloride (PAC), aluminum sulphate and iron (III) chloride. The paper presents the outcomes of removing organic compounds from groundwater, investigates the decolourisation process and discusses pH impact on removing organic compounds and water colour. Aluminum based coagulants have been found to be the most effective regents. pH values have also a very significant impact on the effectiveness of the water coagulation process. Article in Lithuanian. Organinių junginių ir spalvos šalinimo iš požeminio vandens efektyvumas naudojant koaguliantus Santrauka. Organinius junginius iš geriamojo vandens šalinti būtina, nes jie suteikia vandeniui spalvą, vanduo įgyja nemalonų skonį ir kvapą. Organinės medžiagos mažina vandens ruošimo procesų efektyvumą ir reaguodamos su dezinfekcinėmis medžiagomis sudaro antrinius dezinfekcijos produktus, kurie yra toksiški. Šiame straipsnyje nagrinėjamas organinių junginių šalinimo iš požeminio vandens ir vandens spalvos mažinimo efektyvumas naudojant koaguliacijos procesą. Aptariama, kokią įtaką organiniams junginiams šalinti ir spalvos intensyvumui mažinti turi vandens pH vertės. Tiriant buvo naudojami trys koaguliantai: polialiuminio oksichloridas, aliuminio sulfatas ir geležies chloridas. Atlikus tyrimus nustatyta, kad efektyviausiai organinius junginius šalina aliuminio sulfatas ir polialiuminio oksichloridas. Naudojant aliuminio sulfatą, vandens spalvos intensyvumas sumažinamas 83 %, o organinės medžiagos – 85 %. Nustatyta, kad didinant koaguliantų dozes mažėja vandens pH vertės, o tai didina likutinio aliuminio koncentraciją ir blogina koaguliacijos procesą. Raktiniai žodžiai: požeminis vanduo, permanganato indeksas, vandens spalva, pH, koaguliacija, polialiuminio oksichloridas, aliuminio sulfatas, geležies chloridas