Spreading pressures of water and n-propanol on polymer surfaces

Spreading pressures of water and n-propanol on polytetrafluoroethylene (PTFE), polystyrene (PS), polymethylmethacrylate (PMMA), polycarbonate (PC), and glass are determined from ellipsometrically measured adsorption isotherms by graphical integration, yielding for water 9, 37, 26, 33, and 141 erg · cm−2 on PTFE, PS, PMMA, PC, and glass, respectively, while for n-propanol 5, 38, 26, 23, and 37 erg · cm−2, respectively. The spreading pressures for water as well as n-propanol are comparable to values previously obtained from contact angle data with water, water/n-propanol mixtures and α-bromonaphthalene using the geometric mean equation. This method yielded spreading pressures of 9, 14, 30, 27, and 70 erg · cm−2 for PTFE, PS, PMMA, PC, and glass, respectively. The numerical correspondence between the spreading pressures for water and n-propanol determined ellipsometrically with the values derived from contact angles indicates the necessity as well as the validity of taking the spreading pressures of water/n-propanol mixtures into account as a constant, if surface free energies of high energy substrata are approximated by contact angle measurements

Analisi delle prestazioni energetiche delle coperture ventilate

Le esigenze sul contenimento dei consumi energetici degli edifici richiedono un involucro performante nella stagione invernale ed estiva. Un involucro progettato in modo sbagliato, può favorire, nella stagione invernale, la crescita di muffe sulla superficie interna e la condensazione interstiziale che diminuiscono sensibilmente le condizioni di comfort. Questi due fenomeni, inoltre, sono causa frequente di contenzioso civile nel settore delle costruzioni. Nell'ultimo decennio, la diffusione degli impianti di condizionamento ha determinato un sensibile aumento dei consumi di energia elettrica con particolare riguardo alla stagione estiva. Di qui nasce l’esigenza di utilizzo di tecniche passive come la ventilazione delle intercapedini d’aria nelle pareti. Nel presente lavoro si è posto l’obiettivo di valutare i vantaggi conseguibili con l’impiego delle coperture ventilate (piane o a falde) sia nella stagione invernale che quella estiva. Sono stati affrontati problemi tipici della stagione invernale, come muffa e condensa interstiziale, per due coperture piane di frequente utilizzo nell'edilizia per tre diverse località e zone climatiche. Consistenti fenomeni di condensa interstiziale insieme alle esigenze della legislazione vigente (prescrizione sulla totale assenza della condensa interstiziale) hanno richiesto la necessità di intervento. In particolare si può intervenire ventilando l’intercapedine d’aria. Sono state calcolate le portate minime di ventilazione necessarie a evitare la condensa e mostrato un apparecchio tipo con il quale esse possono essere generate. È stata studiata la variazione delle portate d’aria nelle coperture piane in base ad alcuni parametri termo igrometrici (es.: temperatura esterna, umidità relativa esterna e la produzione di vapore all'interno dell’ambiente). Nella stagione estiva è stato calcolato il risparmio energetico conseguibile con due tipologie di coperture ventilate a falde sia nel caso di ventilazione naturale, data dall'effetto camino, sia nel caso della ventilazione forzata, realizzata con un aspiratore. Sono stati calcolati i parametri termici dinamici delle coperture con l’intercapedine d’aria chiusa (non ventilata) e confrontati con le coperture ventilate

Westerscheldemond 1970-2020: een morfologische blik op de toekomst

In dit rapport staat de morfologische ontwikkeling van de Westerscheldemond centraal. Met kennis over de ontwikkeling van de afgelopen periode, wordt een prognose gemaakt van de zandhuishouding in de Westerscheldemond tot aan 2020. Die prognose is gebruikt om mogelijke kansen en bedreigingen te signaleren die van belang kunnen zijn bij het optimaliseren van toekomstig beheer van de Westerscheldemond. In de afgelopen twee eeuwen is het geulenstelsel in de Westerscheldemond veranderd. In het begin van de 19e eeuw waren nog 3 kenmerkende geulen in de monding aanwezig. Tegenwoordig zijn er nog 2 dominante geulen, namelijk de Scheur/Wielingen en het Oostgat. De derde geul (Deurloo) is veranderd in 2 minder duidelijke doorgangen die gescheiden worden door een bank. Het morfologische gedrag van de Westerscheldemond wordt veelal in beeld gebracht door middel van een zandbalans. Op basis van kaartmateriaal over verschillende jaren wordt bepaald of een gekozen gebied zand verliest (export) of juist bergt (import). Vervolgens worden de resultaten met elkaar in verband gebracht door de gebieden van erosie en sedimentatie aan elkaar te koppelen. Zo worden uitspraken gedaan over de eventuele zanduitwisseling tussen gebieden in de Westerscheldemond en ook de daaraan grenzende gebieden (Westerschelde, Noordzee, kusten). De zanduitwisseling is ook geïnterpreteerd in termen van veranderingen in dieptelijnen. Verschillende studies geven aan dat de Westerscheldemond in de periode 1969 - 1993 naast bagger- en stortactiviteiten, zand heeft verloren (115 ± 70 miljoen m3). Dit netto zandverlies is echter niet constant door de jaren heen. Begin jaren 70 is zelfs een zandtoename geconstateerd, en de grootste afname begin jaren 80 lijkt inmiddels al weer voorbij. Die variaties in de zandbalans blijken afhankelijk van menselijke ingrepen, voornamelijk baggeren/storten en kustverdedigingswerken. Maar ook natuurlijke fluctuaties, bijvoorbeeld een 18,6-jarige cyclus in het getij, of aanwezige zandgolven en erodeerbaarheid van het materiaal op de zeebodem zullen van invloed zijn. Hierdoor zal in deelgebieden van de Westerscheldemond verschillend gedrag optreden. Dat gedrag bepaalt bijvoorbeeld langs de kusten de zandsuppletiebehoefte, in de geulen de baggerbehoefte en op de platen de stortmogelijkheden. In de Westerscheldemond zijn lokaal van belang de stabiliteit van het platenstelsel, de Raan, en de stabiliteit van het huidige twee-geulenstelsel (Scheur/Wielingen en Oostgat). Voor de kust van Zeeuwsch-Vlaanderen zijn de zandgolven van belang en voor de kust van zuidwest Walcheren moet rekening gehouden worden met stroomresistente lagen. Voor beide kustgedeelten zijn aangebrachte harde constructies (havens, verdedigingswerken) mede bepalend voor het morfologische gedrag. Een morfologische voorspelling (in dit rapport tot aan 2020) is een interpretatie van de opgestelde zandbalans. Die interpretatie is niet eenvoudig. Het combineert kennis over het waargenomen gedrag van de Westerscheldemond met algemene uitspraken (evenwichtsrelaties) over vergelijkbare morfologische systemen. De moeilijkheid in de interpretatie zit in de beperkte geldigheid van evenwichtsrelaties in systemen die zo door de mens zijn beïnvloed. Bovendien zijn onnauwkeurigheid (en beschikbaarheid) van dieptegegevens, maar ook verandering in zeespiegelstijging en getij, aanwezigheid van slib, menselijk handelen in en rond het interessegebied van invloed. Aannames over mogelijk toekomstig menselijk handelen en over natuurlijke processen als zeespiegelstijging zijn noodzakelijk voor het maken van een morfologische voorspelling. Daartoe zijn in dit rapport een vijftal scenario\u92s onderscheiden. Het betreft: i) voortzetting huidig beleid, ii) verandering in autonome aansturing (waaronder verandering in zeespiegelstijging), iii) verandering van ingrepen in de Westerschelde, iv) verandering van ingrepen in de monding en tenslotte v) een specifiek geval, namelijk een algemene verdieping van de vaarweg naar Antwerpen. Met de huidige kwalitatieve kennis wordt gesteld dat zonder een versnelde zeespiegelstijging de morfologische veranderingen op de zandbalans tot 2020 marginaal blijven. Een ernstige verstoring van de zandhuishouding wordt voor de onderscheiden scenario\u92s dus niet verwacht. Het huidige beleid zal ook in de komende decennia kunnen voldoen, waarbij zich mogelijkheden voordoen bij de uitvoering daarvan. Een verhoogde Paardenmarkt (stortlokatie) biedt bijvoorbeeld bescherming tegen de golfaanval op de kust. Dit kan het aantal zandsuppleties verminderen die nodig zijn om de kust van Zeeuwsch Vlaanderen te handhaven. De aanzanding van het Zwin zal dan tevens afnemen. Als ook zand gestort zou worden in de Appelzak, dan wordt een verdergaande verdieping van die geul tegengegaan en blijft de munitie uit de eerste wereldoorlog begraven. De verwachting is dat deze stortlokaties goed bereikbaar blijven vanuit zee. Een van de grootste kansen in de Westerscheldemond is om het zand dat afkomstig is uit de verdiepingswerkzaamheden te gebruiken in een onderwatersuppletie. Onderzocht zal moeten worden of dit zand op termijn daadwerkelijk ten goede zal kunnen komen aan het BKL-volume van Zeeuwsch-Vlaanderen. Bij een verdieping zal rekening gehouden moeten worden met de aanwezige kleilagen. Het wegbaggeren van resistente kleilagen, bijvoorbeeld in de Scheur/Wielingen, zal immers geen gunstige morfologische ontwikkeling in gang zetten. De aanwezige harde constructies voor de kust van zuidwest Walcheren verhinderen de oostwaartse migratie van het Oostgat. Die door de mens beheersde stabiele situatie betekent echter niet dat er in de nabijheid zand gewonnen kan worden. Als ten gevolge van zandwinning op bijvoorbeeld het Bankje van Zoutelande het Bankje doorbreekt, zal dat hinder opleveren voor de scheepvaart. Afsluitend wordt gesteld dat door de stabiliteit van de Raan er zich mogelijkheden voordoen voor intensiever gebruik van de Raan. Een studie naar de aanleg van een windmolenpark of eiland zal de haalbaarheid echter nog moeten aangeven. Nog niet alle mogelijkheden en onmogelijkheden van de Westerscheldemond zijn bekend. In dit rapport wordt gesteld dat in geval van een versnelde zeespiegelstijging er waarschijnlijk rekening gehouden moet worden met een extra zandbehoefte in de Westerscheldemond. De consequenties voor het beheer is echter nog niet kwantitatief aangegeven. Hiervoor is het nodig dat de interpretatie van de zandbalans beter wordt onderbouwd. Bij concrete vragen naar de gevolgen van een geulverdieping, zal aandacht besteedt moeten worden aan de ontwikkeling van een modelinstrumentarium dat onder andere de gevolgen van getijdoordringing in de Westerschelde, alsook de interactie met het Oostgat kan aangeven

Professor Andrew David Hamilton Wyllie – Biographical Memoir

Andrew Wyllie graduated from Aberdeen University, becoming an academic pathologist in Aberdeen, Edinburgh and Cambridge. He was the co-discoverer of apoptotic cell death having observed single cells dying following carcinogen exposure. Together with Alastair Currie and John Kerr, he realised the profound importance of this novel mode of cell death that showed a distinctive series of morphological changes, which he first described as a new cell death process. Wyllie and Currie introduced the term “apoptosis” for this cell death process in a seminal paper in 1972. Another landmark discovery was of chromatin fragmentation in apoptosis, due to activation of an endogenous endonuclease that caused internucleosomal DNA cleavage (“chromatin laddering”), which was the first biochemical mechanism of apoptosis. He further characterised chromatin fragmentation in the 1980s, followed by investigations of cell surface changes to produce “eat-me” signals to trigger rapid phagocytosis of the apoptotic cells and bodies, intracellular calcium ion signalling, caspase activation and other mechanisms of apoptosis. His cancer research helped identify the location of APC and generated his demonstration that apoptosis was regulated by oncogenes, MYC and RAS, and tumour suppressor genes, such as TP53. He showed how apoptosis occurred in response to DNA damage and was a key process influencing both carcinogenesis and tumour growth. Andrew made a major scientific observation that changed the understanding of how cells die in health and disease, although it took time for the scientific establishment to understand its fundamental importance. Andrew Wyllie is widely known as the ‘Father of Apoptosis’

Interventions to facilitate return to work in adults with adjustment disorders

BACKGROUND: Adjustment disorders are a frequent cause of sick leave and various interventions have been developed to expedite the return to work (RTW) of individuals on sick leave due to adjustment disorders. OBJECTIVES: To assess the effects of interventions facilitating RTW for workers with acute or chronic adjustment disorders. SEARCH METHODS: We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR) to October 2011; the Cochrane Central Register of Controlled Trials (CENTRAL) to Issue 4, 2011; MEDLINE, EMBASE, PsycINFO and ISI Web of Science, all years to February 2011; the WHO trials portal (ICTRP) and ClinicalTrials.gov in March 2011. We also screened reference lists of included studies and relevant reviews. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) evaluating the effectiveness of interventions to facilitate RTW of workers with adjustment disorders compared to no or other treatment. Eligible interventions were pharmacological interventions, psychological interventions (such as cognitive behavioural therapy (CBT) and problem solving therapy), relaxation techniques, exercise programmes, employee assistance programmes or combinations of these interventions. The primary outcomes were time to partial and time to full RTW, and secondary outcomes were severity of symptoms of adjustment disorder, work functioning, generic functional status (i.e. the overall functional capabilities of an individual, such as physical functioning, social function, general mental health) and quality of life. DATA COLLECTION AND ANALYSIS: Two authors independently selected studies, assessed risk of bias and extracted data. We pooled studies that we deemed sufficiently clinically homogeneous in different comparison groups, and assessed the overall quality of the evidence using the GRADE approach. MAIN RESULTS: We included nine studies reporting on 10 psychological interventions and one combined intervention. The studies included 1546 participants. No RCTs were found of pharmacological interventions, exercise programmes or employee assistance programmes. We assessed seven studies as having low risk of bias and the studies that were pooled together were comparable. For those who received no treatment, compared with CBT, the assumed time to partial and full RTW was 88 and 252 days respectively. Based on two studies with a total of 159 participants, moderate-quality evidence showed that CBT had similar results for time (measured in days) until partial RTW compared to no treatment at one-year follow-up (mean difference (MD) -8.78, 95% confidence interval (CI) -23.26 to 5.71). We found low-quality evidence of similar results for CBT and no treatment on the reduction of days until full RTW at one-year follow-up (MD -35.73, 95% CI -113.15 to 41.69) (one study with 105 participants included in the analysis). Based on moderate-quality evidence, problem solving therapy (PST) significantly reduced time until partial RTW at one-year follow-up compared to non-guideline based care (MD -17.00, 95% CI -26.48 to -7.52) (one study with 192 participants clustered among 33 treatment providers included in the analysis), but we found moderate-quality evidence of no significant effect on reducing days until full RTW at one-year follow-up (MD -17.73, 95% CI -37.35 to 1.90) (two studies with 342 participants included in the analysis). AUTHORS' CONCLUSIONS: We found moderate-quality evidence that CBT did not significantly reduce time until partial RTW and low-quality evidence that it did not significantly reduce time to full RTW compared with no treatment. Moderate-quality evidence showed that PST significantly enhanced partial RTW at one-year follow-up compared to non-guideline based care but did not significantly enhance time to full RTW at one-year follow-up. An important limitation was the small number of studies included in the meta-analyses and the small number of participants, which lowered the power of the analyses

The effect of three years of TNF alpha blocking therapy on markers of bone turnover and their predictive value for treatment discontinuation in patients with ankylosing spondylitis: a prospective longitudinal observational cohort study

INTRODUCTION: The aim of this study was to investigate the effect of three years of tumor necrosis factor-alpha (TNF-alpha) blocking therapy on bone turnover as well as to analyze the predictive value of early changes in bone turnover markers (BTM) for treatment discontinuation in patients with ankylosing spondylitis (AS). METHODS: This is a prospective cohort study of 111 consecutive AS outpatients who started TNF-alpha blocking therapy. Clinical assessments and BTM were assessed at baseline, three and six months, as well as at one, two, and three years. Z-scores of BTM were calculated to correct for age and gender. Bone mineral density (BMD) was assessed yearly. RESULTS: After three years, 72 patients (65%) were still using their first TNF-alpha blocking agent. In these patients, TNF-alpha blocking therapy resulted in significantly increased bone-specific alkaline phosphatase, a marker of bone formation; decreased serum collagen-telopeptide (sCTX), a marker of bone resorption; and increased lumbar spine and hip BMD compared to baseline. Baseline to three months decrease in sCTX Z-score (HR: 0.394, 95% CI: 0.263 to 0.591), AS disease activity score (ASDAS; HR: 0.488, 95% CI: 0.317 to 0.752), and physician's global disease activity (HR: 0.739, 95% CI: 0.600 to 0.909) were independent inversely related predictors of time to treatment discontinuation because of inefficacy or intolerance. Early decrease in sCTX Z-score correlated significantly with good long-term response regarding disease activity, physical function and quality of life. CONCLUSIONS: Three years of TNF-alpha blocking therapy results in a bone turnover balance that favors bone formation, especially mineralization, in combination with continuous improvement of lumbar spine BMD. Early change in sCTX can serve as an objective measure in the evaluation of TNF-alpha blocking therapy in AS, in addition to the currently used more subjective measures

Human papillomavirus type 18 is associated with less apoptosis in fibroblast tumours than human papillomavirus type 16.

In human cervical neoplasia human papillomavirus (HPV) type 18 has a higher cancer/cervical intraepithelial neoplasia (CIN) prevalence ratio than HPV 16. Fibrosarcomas derived from rat fibroblasts transfected with HPV 16 or 18 genomes showed increased apoptosis compared with controls. However, HPV 18 was associated with significantly less apoptosis than HPV 16, affording one possible explanation for the more rapidly progressive cervical neoplasia associated with HPV 18

Photoproduction of pions and etas in nuclei

We calculate the cross sections for inclusive one-pion, two-pion and eta photoproduction in nuclei in the photon energy range from 300 MeV to 900 MeV within the framework of a semi-classical BUU transport model. Our results are compared with existing experimental data and discussed with respect to a calculation of the total photoabsorption cross section.Comment: 30 pages LaTeX including 13 postscript figure

Measuring water sorption isotherm of mortar containing chloride

The water sorption isotherm of materials is of great importance to predict their durability. Many different methods are used in the literature to measure this water sorption isotherm. Chloride present in concrete elements/structures e.g. in marine exposure, can change the water sorption of the material. In this paper, the water sorption isotherm of a standard mortar with and without chloride is measured with a hygroscopic method. The chloride penetration into the sample is obtained by the vacuum saturation method. Subsequently the sample is placed in a glass vessel and dried. By injecting a known amount of water into the vessel, the water evaporates and is partly adsorbed by the sample until an equilibrium state is reached. With the known amount of the injected water into the vessel, the humidity inside the vessel and the volume of the vessel, one point of the adsorption isotherm is determined. For measuring the next point, more water is injected into the vessel. More points are measured in the same manner until the sample is saturated and with this the adsorption isotherm is completed. Afterwards, the measurement of the desorption isotherm starts with blowing dry air with a known flow, humidity and duration into the vessel. After reaching equilibrium, the first point of the desorption curve is measured. The next point is measured by blowing more dry air into the vessel. This continues until the sample is completely dry and with it the desorption isotherm is also completed