Grain boundaries (GBs) have critical influences on the stability and properties of various materials. In this study, first-principles calculations were performed to determine the effects of four ...metallic impurities (Ni, Al, Bi, and Pb) and three nonmetallic impurities (H, O, and N) on the GBs of silicon carbide (SiC), using the Σ5(210) GBs as models. The GB energy and segregation energy (SE) were calculated to identify the effects of impurities on the GB stability. Electronic interactions considerably influenced the bonding effects of SiC. The formation of weak bonds resulted in the corrosion and embrittlement of GBs. The co-segregation of Bi, Pb, and O was also investigated in detail.
A number of recent terrorist attacks make it clear that rapid response, high sensitivity and stability are essential in the development of chemical sensors for the detection of chemical warfare ...agents. Nerve agent sarin 2-(fluoro-methyl-phosphoryl) oxypropane is an organophosphate (OP) compound that is recognized as one of the most toxic chemical warfare agents. Considering sarin's high toxicity, being odorless and colorless, dimethyl methylphosphonate (DMMP) is widely used as its simulant in the laboratory because of its similar chemical structure and much lower toxicity. Thus, this review serves to introduce the development of a variety of fabricated chemical sensors as potential sensing materials for the detection of DMMP in recent years. Furthermore, the research and application of carbon nanotubes in DMMP polymer sensors, their sensitivity and limitation are highlighted. For sorption-based sensors, active materials play crucial roles in improving the integral performances of sensors. The novel active materials providing hydrogen-bonds between the polymers and carbon nanotubes are the main focus in this review. Keywords: carbon nanotubes, DMMP, chemical sensor, conductive polymer. Streszczenie: Przeprowadzone w ostatnich latach liczne ataki terrorystyczne jasno wskazuja, ze w wypadku czujnikow do wykrywania chemicznych srodkow bojowych sa niezbedne: ich wysoka czulosc, szybka reakcja i stabilnosc. Srodek paralityczno-konwulsyjny sarin (2-fluorometylofosforylooksypropan) to zwiazek fosforoorganiczny (OP) uznawany za jeden z najbardziej toksycznych dostepnych chemicznych srodkow bojowych. Ze wzglcdu na to, ze jest on bezwonny, bezbarwny, a ponadto bardzo toksyczny, w badaniach laboratoryjnych szeroko stosuje sie jego symulator--metylofosfonian dimetylu (DMMP), o podobnej strukturze chemicznej i znacznie mniejszej toksycznosci. W artykule przedstawiono rozwoj technologii czujnikow chemicznych do wykrywania gazu DMMP. Omowiono badania dotyczace wykorzystania kompozytow polimerowych z udzialem nanorurek weglowych w czujnikach gazu DMMP. W wypadku czujnikow, w ktorych wykorzystuje sic zjawisko sorpcji, kluczowa role w poprawie ich wydajnosci odgrywaja materialy aktywne. W niniejszym przegladzie skupiono sie na nowatorskich materialach aktywnych, w ktorych wystepuja wiazania wodorowe miedzy polimerem a nanorurkami weglowymi. Stowa kluczowe: nanorurki weglowe, DMMP, czujnik chemiczny, polimer przewodzacy.
The task of this brief editorial is to provide a concise tour d’horizon of EU law development in the field of the Rule of Law over the last years, which have significantly reinforced the powers of ...the supranational institutions in the domains, which have previously never been considered part of supranational competence/purview of regulation. While the EU has thereby matured, entering a period of new, more credible ‘constitutionalism’ claims, the solution of the problems, which this de facto power grab was intended to solve is nowhere in sight: delegating sore issues to ‘Europe’ does not bring the expected dividends in the populist times, inviting a conversation about alternative approaches and solutions required.
En este trabajo se propone una metodología eficiente para la localización y operación óptima de almacenadores de energía (AE) en micro-redes (MR) a través de un modelo de programación lineal entera ...mixta (MPLEM). El modelo matemático desarrollado corresponde a un modelo de despacho económico para miro-redes (DEMR) con presencia de generación distribuida (GD) a partir de recursos energéticos renovables. Como función objetivo se considera la minimización de los costos de compra de energía en la bolsa por parte del agente operador de red, teniendo en cuenta dos escenarios de operación; el primero considera un precio de energía fijo; y el segundo, precios variables en el nodo que conecta la MR al sistema de potencia para un horizonte operativo de 24 horas. Como restricciones se consideran los flujos de potencia por la línea a través de un modelo de flujo en redes, las capacidades de almacenamiento de los AE y las capacidades horarias de generación de potencia en los GD. Para resolver el MPLEM propuesto se emplea el paquete de optimización comercial GAMS, empleando el solver CPLEX. La metodología propuesta permite localizar, dimensionar y operar los AE, considerando como horizonte de operación, un día típico laboral en Colombia, adicionalmente se tienen en cuenta diferentes consignas operativas en la operación de los AE según los estándares existentes. Con el fin de conocer las variables de estado de la MR, es empleado un flujo de potencia del tipo barrido iterativo para evaluar las respuestas obtenidas por el MPLEM. Esta evaluación permite hallar los costos operativos reales de la MR. Para validar el modelo matemático propuesto es empleado un sistema de prueba de la literatura especializada de 7 nodos con presencia de dos generadores distribuidos, siendo uno de tipo fotovoltaico y el otro tipo eólico. Los resultados obtenidos muestran la eficiencia de la metodología propuesta, así como su facilidad de implementación y la capacidad de adaptación para sistemas de mayor tamaño.
Kao jedna od najstarijih grupa fotoautotrofnih mikroorganizama, cijanobakterije predstavljaju široko rasprostranjene prokariote sa raznovrsnim metaboličkim strategijama u cilju preživljavanja i ...adaptacije na različite uslove životne sredine. Upravo zbog toga, cijanobakterije su značajne kao producenti različitih biološki aktivnih metabolita. Međutim, većina studija o cijanobakterijama uglavnom je vezana za cijanobakterije vodenih ekosistema. Predmet istraživanja ovog rada je utvrđivanje diverziteta autohtonih cijanobakterija šumskih ekosistema i karakterizacija odabranih terestričnih cijanobakterijskih predstavnika planinskih područja Srbije izolovanih tokom trogodišnjeg monitoringa kroz utvrđivanje njihovih osnovnih ekofizioloških, biohemijskih i genetičkih karakteristika. Rezultati dobijeni u ovom radu su ukazali na diverzitet zemljišnih cijanobakterija šumskih staništa ispitivanih planinskih područja kao i na njihov metabolički diverzitet, odnosno potencijal produkcije različitih bioaktivnih jedinjenja. Na osnovu taksonomski važnih odlikaidentifikovano je i okarakterisano 20 cijanobakterijskih sojeva za koje je utvrđeno da pripadaju sledećim rodovima:Nostoc, Anabaena, Tolypothrix, Calothrix, Cylindrospermum, Lyngbya, Oscillatoria, Phormidium. Identifikacija izolovanih cijanobakterija primenom molekularanog markera 16S rRNK u većini slučajeva (90%) je potvrdila preliminarnu identifikaciju rodova na osnovu morfoloških kriterijuma. U pogledu produkcije biomase dobijeni rezultati su pokazali da jeprodukcija biomase kod odabranih testiranih cijanobakterijskih sojeva zavisila od primenjenih uslova kultivacije. Utvrđeno je da su azot, glukoza i saharoza delovali u pravcu stimulacije produkcije biomase kod velikog broja sojeva. Najveća produkcija biomase detektovana je kod sojaCalothrixM2 u prisustvu azota u medijumu. Kod sojaNostocT18 zabeleženo je najveće povećanje produkcije biomase u prisustvu glukoze i saharoze u medijumu. Takođe, sadržaj fikobiliproteina bio je povećan kod većine testiranih sojeva u prisustvu glukoze i saharoze u medijumu. Ispitivanjem sadržaja ugljenih hidrata (glukoze, fruktoze i ksiloze) konstatovano je prisustvo sva tri monosaharida kod svih sojeva pri čemu je svaki soj imao specifičan ugljeno-hidratni profil. Sadržaj monosaharida kod svih testiranih sojeva opadao je u sledećem redosledu glukoza ˃fruktoza ˃ ksiloza. Izuzetnu sposobnost produkcije heksoza i pentoza ispoljila su tri sojaNostocM1, PhormidiumT11 iCalothrixM2. Antibakterijska aktivnost intracelularnih ekstrakata registrovana je kod 16 testiranihcijanobakterijskih sojeva i zavisila je od kombinacije cijanobakterijski-bakterijski soj i tipa primenjenog ekstrakta. U odnosu na heksanske ekstrakte, metanolni ekstrakti su pokazali veću efikasnost, ukazujući na prirodu bioaktivnih jedinjenja sa antibakterijskim delovanjem. Najefikasnijim su se pokazali 75% MeOH ekstrakti cijanobakterijskih sojevaOscillatoriaM2, Calothrix M2,LyngbyaT7 iCylindrospermumK1 koji su ispoljili antibakterijsku aktivnost na 4 testirane bakterije. Hemijskom analizom masno kiselinskog sastava utvrđeno je da je masno kiselinski sadržaj cijanobakterijskih sojeva varirao u zavisnosti od soja. Najznačajniji konstituenti testiranih cijanobakterijskih sojeva bile su 18-to i 16-to ugljenične masne kiseline poput linolne kiseline i α-linoleinske. Najveći sadržaj linolne kiseline detektovan je kod sojeva Phormidium T11 i Tolypothrix K11 što ukazuje na sojeve kao potencijalno značajne izvore esencijalnih masnih kiselina. Antiradikalska aktivnost detektovana je kod svih testiranih cijanobakterijskih sojeva. U DPPH eseju, etanolni ekstrakti soja Calothrix M2 ispoljili su najefikasniju sposobnost „hvatanja“ DPPH·radikala dok je u slučaju FRAP metode najveću redukujuću moć imao etanolni ekstrakt soj Cylindrospermum K1. Hemijskom analizom fenolnog sastava kod analiziranih cijanobakterijskih sojeva identifikovano je i kvantifikovano ukupno 21 fenolno jedinjenje. Fenolni sastav je varirao u zavisnosti od soja, a najčešće detektovana fenolna jedinjenja bila su luteolin-7-O-glukozid, bajkalin i kemferol. Soj sa najznačajnijom sposobnošću produkcije fenolnih jedinjenja bio jePhormidiumM1 kod koga je identifikovano prisustvo 11 fenolnih jedinjenja. Testirajem toksičnosti intracelularnih ekstrakata u biotestovima A. salina, D. magna i D. rerio ukupno 40% testiranih sojeva ispoljilo je toksičan efekat. Najtoksičnijim sojem se pokazao sojNostoc T7 koji je ispoljio toksičnost u sva tri testa. U slučaju biotestaA. salinanajtoksičnijim sojevima pokazali su seNostocT7,OscillatoriaM2, OscillatoriaT18 iNostocK15. Cijanobakterijski sojevi koji su ispoljili najpotentniju aktivnost u biotestuD. magna bili su Tolypothrix K15, Nostoc T7 i Calothrix M2. U biotestu sa embrionima zebrica, soj sa najznačajnijim teratogenim efektom bio je CylindrospermumK1. U pogledu uticaja ekstrakta testiranog soja na ekspresiju gena kod model organizmaD. rerio,CylindrospermumK1 je ispoljio sposobnost modulacije bioloških procesa poput cirkadijalnog ritma kao i sposobnost produkcije jedinjenja sa estrogenim efektom. Rezultati analize toksigeničnosti testiranih cijanobakterijskih sojeva su pokazali da genimcyBimcyEkoji su uključeni u produkciju cijanotoksina mikrocistina nisu detektovani ni u jednom od testiranih sojeva. Odsustvo dva gena iz mcy genskog klastera ukazuje na to da su druga jedinjenja odgovorna za uočen toksični efekat u primenjenim biotestovima. Dobijeni rezultati ukazuju na značaj ispitivanja zemljišnih cijanobakterija, s obzirom na to da su rezultati ovog rada ukazali na velik metabolički diverzitet ispitivanih sojeva i izražen potencijal produkcije različitih bioaktivnih jedinjenja.
Introduction:Pleural effusion is the pathological accumulation of fluid in the pleural space affecting 15% of the total number of tuberculosis cases. It is the second most frequent presentation of ...human tuberculosis. There are 2 types pleural effusion - (i) exudative and (ii) transudative. Since the number of organisms present in the pleural effusion is very small, conventional methods for the detection of mycobacterium tuberculosis are often of no use. Even the closed pleural biopsy helps only in 60% of the cases. The diagnosis of tubercular pleural effusion is very important, because earlier the diagnosis better will be the outcome.Early diagnosis of tubercular pleural effusion is greatly improved by biochemical markers. Such as adenosine-de-aminase (ADA) interferon-γ and lysozyme etc. Among them determination of ADA is most promising, because of its is rapidity and cost effectiveness.The present study is undertaken to know the diagnostic role of ADA in patients admitted with pleural effusion at hospitals attached to J.J.M.M.C. Davangere, and correlating the level of ADA in tubercular and non-tubercular pleural effusion.Methodology:The present prospective study is conducted for a period of 1 year from December 2013 to December 2014. All the patients above the age group of 18 years presenting with clinical features of pleural effusion who gave the informed consent for the study were included. Detailed history, physical examination and required routine investigations were done.Results and Discussion:The mean ± SD in TBPE in our study is 79.27±59.45 with cut off value of 40 U/L and sensitivity is 71% specificity 100%, PPV 100%, NPV 40%.Conclusions:Pleural fluid ADA were significantly elevated in tubercular pleural effusion. Hence finding in our study supports the view that pleural fluid ADA estimation is a very useful in establishing the accurate and early diagnosis of pleural effusion secondary to tuberculosis.
With the advent of flexible Fibre-optic bronchoscopy, bronchial washings have been a resourceful, rapid and economical first line cytology technique in the diagnosis and management of non-neoplastic ...and neoplastic lesions of the lung.Objectives:To study the cytological features of bronchial washings.To study the cyto-histopathlogical correlation when biopsy is also doneMaterials & Methods:This study emphasizes the role of bronchial washings in the diagnosis of lung diseases and its correlation with bronchial biopsy findings. This is a prospective study, undertaken in the Department of Pathology, J.J.M. Medical college, Davangere, during the period of August 2013 to July 2015. During the period of present study, 150 bronchial washings were collected from 150 patients and 44 bronchial biopsy specimen were collected from 44 patients.Results: 150 bronchial wash samples formed 17.9% of total 838 body fluid samples received during the period of this study. The age group ranged from 5 years to 80 years with a mean age of 42.5 years. Majority of the patients belonged to the age group of 60-69 years (30.7%) followed by 70-79 years(18.7%), 50-59 years(17.3%), 40-49 years(15.3%), 30-39 years(12.7%). Male to female ratio was 5.52:1. Among 150 patients, on bronchial wash cytology, 125 patients (83.33%) were diagnosed as Non-specific inflammation/Negative for malignancy. 4 non-neoplastic lesions with one case each of Candidiasis, Mucormycosis, Respiratory Syncytial Virus/Measles infection and Granulomatous inflammation were diagnosed.Among the total 21 cases of neoplastic lesions, 15 cases(10%) were squamous cell carcinoma, 3cases of Positive for malignancy (2%) and one each cases of Small cell carcinoma, Adenocarcinoma and Large undifferentiated carcinoma were reported. Among the 44 cases of bronchial biopsies, 5 cases of nonneoplastic lesions with 2 cases of inflammatory lesion, one case each of Plant seed, Mucormycosis and granulation tissue were reported. The neoplastic lesions were 22 out of 44 biopsies, and in order of frequency Squamous cell carcinoma 11(25%), Poorly differentiated carcinoma 7(15.9%), and one case each of Adenocarcinoma and Lymphoma were reported. Cytohistopathological correlation was done in 43 cases of 44 biopsies, because the biopsy specimen was inadequate in one patient.Conclusion:Bronchial washings and bronchial biopsies are basic, safe, rapid and costeffective diagnostic tools in the early diagnosis of lung lesions. Bronchial washings have an excellent sensitivity, specificity and accuracy comparable to biopsy and post biopsy bronchial washings have a greater yield compared to pre-biopsy washings.
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