Exhaled air analysis using wideband wave number tuning range infrared laser photoacoustic spectroscopy

The infrared laser photoacoustic spectroscopy (LPAS) and the pattern-recognition-based approach for noninvasive express diagnostics of pulmonary diseases on the basis of absorption spectra analysis of the patient’s exhaled air are presented. The study involved lung cancer patients ( N = 9 ), patients with chronic obstructive pulmonary disease ( N = 12 ), and a control group of healthy, nonsmoking volunteers ( N = 11 ). The analysis of the measured absorption spectra was based at first on reduction of the dimension of the feature space using principal component analysis; thereafter, the dichotomous classification was carried out using the support vector machine. The gas chromatography–mass spectrometry method (GC–MS) was used as the reference. The estimated mean value of the sensitivity of exhaled air sample analysis by the LPAS in dichotomous classification was not less than 90% and specificity was not less than 69%; the analogous results of analysis by GC–MS were 68% and 60%, respectively. Also, the approach to differential diagnostics based on the set of SVM classifiers usage is presented

Investigation of new modification strategies for PVA membranes to improve their dehydration properties by pervaporation

International audienceNovel supported membranes based on polyvinyl alcohol (PVA) were developed using two strategies: first, by the modification of the PVA network, via so-called bulk modification, with the formation of the selective layer accomplished through the introduction of fullerenol and/or poly(allylamine hydrochloride), and second, by the functionalization of the surface with successive depositions of multilayered films of polyelectrolytes, such as poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) on the PVA surface. The membrane surface modifications were characterized by scanning electron microscopy and contact angle measurements. The modified PVA membranes were examined for their dehydration transport properties by the perva-poration of isopropyl alcohol-water (80/20% w/w), which was chosen as a model mixture. Compared with the pristine PVA membrane, the main improvement was a marked increase in permeance. It was found that the surface modifications mainly gave rise to a higher global flux but with a strong reduction in selectivity. Only the combination of both bulk and surface modifications with PEL could significantly increase the flux with a high water content in the permeate (over 98%). Lastly, it should be noted that this study developed a green procedure to prepare innovative membrane layers for dehydration, making use of only water as a working medium

ПОЛУЧЕНИЕ И СВОЙСТВА ТОНКОПЛЕНОЧНЫХ КОМПОЗИЦИОННЫХ ПОЛОВОЛОКОННЫХ МЕМБРАН ДЛЯ УЛЬТРАФИЛЬТРАЦИИ С НИЗКИМ НОМИНАЛЬНЫМ МОЛЕКУЛЯРНО-МАССОВЫМ ПРЕДЕЛОМ ОТСЕЧЕНИЯ

Fullerenol C60(OH)24 was incorporated into a polyamide (PA) selective layer to develop novel thin film nanocomposite (TFN) hollow fiber membranes for low molecular weight cut-off ultrafiltration. TFN membranes were fabricated using the interfacial polycondensation technique by alternately pumping a fullerenol dispersion into the triethylenetetramine (TETA) aqueous solution and the isophthaloyl chloride solution into hexane through polysulfone hollow fiber membranes. The contact angle of the skin layer was found to decrease sharply from 34 to 21° when the concentration of fullerenol increases up to 0.5 wt. % in the TETA aqueous solution. Antifouling properties of the PA/fullerenol membranes were found to be superior to the initial membrane. The maximum fouling recovery ratio was observed for the TFN membrane with 0.3–0.75 wt. % of fullerenol in the TETA aqueous solution. Тонкопленочные композиционные мембраны (ТКМ) для ультрафильтрации с низким номинальным молекулярно-массовым пределом отсечения были получены при введении добавок фуллеренола C60(OH)24 в селективный полиамидный (ПА) слой, сформированный методом межфазной поликонденсации при использовании в качестве подложки половолоконной ультрафильтрационной мембраны на основе полисульфона. Межфазную поликонденсацию с образованием тонкого полиамидного слоя проводили при последовательной фильтрации раствора триэтилентетрамина (ТЭТА) в воде и раствора изофталоилхлорида в гексане через половолоконную мембрану. При увеличении концентрации фуллеренола в водном растворе ТЭТА угол смачивания селективного слоя уменьшается с 34 до 21°. Показано, что устойчивость к засорению ТКМ ПА/фуллеренол выше, чем исходной немодифицирован- ной мембраны. Мембраны, полученные с использованием 0,3–0,75 % дисперсий фуллеренола в растворе ТЭТА, характеризовались максимальным значением восстановления потока после фильтрации раствора лизоцима.

Dibromidobis(3,5-dimethyl-1H-pyrazole-κN 2)cobalt(II)

In the mononuclear title complex, [CoBr2(C5H8N2)2], the CoII atom is coordinated by two N atoms from two monodentate 3,5-dimethyl­pyrazole ligands and two Br atoms in a highly distorted tetra­hedral geometry. In the crystal, the complex mol­ecules are linked by inter­molecular N—H⋯Br hydrogen bonds into chains along [101]. An intra­molecular N—H⋯Br hydrogen bond is also present

Fiction of the XIX-XX centuries in prevention of drug addiction

The article raises the problem of prevention of drug addiction through images created in the literature of the XIX-XX centuries. The main attention is paid to the works of "cruel realism" and those hard-hitting images of drug addiction that were created in these works and demonstrate the real situation in which the subject who uses narcotic drugs falls: loss of social ties, "withdrawal", constant search for prohibited substances and attitude to life and death. At the end of the work, conclusions were drawn about possible ways of using images of fiction in the fight against drug addictionВ статье поднимается проблема профилактики наркотической зависимости посредством образов, создаваемых в художественной литературе XIX-XX веков. Основное внимание уделено произведениям «жестокого реализма» и тем нелицеприятным образам наркотической зависимости, которые созданы в данных работах и демонстрируют реальную ситуацию, в которую попадает субъект, употребляющий наркотические средства: потеря социальных связей, «ломка», постоянный поиск запрещенных веществ и отношение к жизни и смерти. В завершении работы сделаны выводы о возможных путях применения образов художественной литературы в деле борьбы с наркоманией

Research experience of foreign scientific medical literature on the features of pulpitis treatment

The article reviews studies on the prevalence and epidemiology of endodontic pathologies present in patients who attended a consultation at the School of Dentistry of the University of Cartagena, analyzes the knowledge of dentists regarding a conservative approach to the treatment of deep carious lesions (DCL) of teeth with reversible pulpitis.В статье рассмотрены исследования о распространенности и эпидемиологии эндодонтических патологий, присутствующих у пациентов, посещавших консультацию в Школе стоматологии Картахенского университета, проанализированы знания стоматологов относительно консервативного подхода в лечении глубоких кариозных поражений (ДКЛ) зубов с обратимым пульпито

Unexpected Temperature Behavior of Polyethylene Glycol Spacers in Copolymer Dendrimers in Chloroform

We have studied copolymer dendrimer structure: carbosilane dendrimers with terminal phenylbenzoatemesogenic groups attached by poly(ethylene) glycol (PEG) spacers. In this system PEG spacers areadditional tuning to usual copolymer structure: dendrimer with terminal mesogenic groups. Thedendrimer macromolecules were investigated in a dilute chloroform solution by 1H NMR methods(spectra and relaxations). It was found that the PEG layer in G = 5 generations dendrimer is “frozen”at high temperatures (above 260 K), but it unexpectedly becomes “unfrozen” at temperatures below250 K (i.e., melting when cooling). The transition between these two states occurs within a smalltemperature range (~10 K). Such a behavior is not observed for smaller dendrimer generations (G = 1and 3). This effect is likely related to the low critical solution temperature (LCST) of PEG and is caused bydendrimer conformations, in which the PEG group concentration in the layer increases with growing G.We suppose that the unusual behavior of PEG fragments in dendrimers will be interesting for practicalapplications such as nanocontainers or nanoreactors.</p