The Mixed-Valence <i>Catena</i>-Heteropolycation (Bi₂S₂)⁺

The reaction of Bi and Bi2S3 in the Lewis-acidic ionic liquid [BMIm]Cl . 4.3AlCl(3) (BMIm=1-n-butyl-3-methylimidazolium) at 200 degrees C yielded air-sensitive black crystals of (Bi2S2)[AlCl4]. X-ray diffraction on single-crystals revealed a monoclinic structure containing infinite chains infinity 1(Bi2S2) + . These polycations contain bismuth(II,III) and sulfur(-II) atoms, connected by polar covalent Bi-S and Bi-Bi bonds. The assignment of bonds is ambiguous as a distinction between primary and secondary interactions is arbitrary based on interatomic distances. A real-space quantum chemical bonding analysis, including delocalization indices, helped to quantify the interactions and charge distribution, confirming that a simple Lewis formula is inappropriate to describe the polycation

Enhancing environmental quality in agricultural systems

Greenhouses have been extremely successful in providing abundant, cheap and high-quality produce, by using resources (water, minerals, pesticides) with a very high economic efficiency. Marginal agricultural land is being rapidly converted into protected cultivation in many (semi-arid) regions of the world, hoping to pros-per both from primary and secondary activities. Water use efficiency of greenhouse production is about five times as high as field production of vegetables. However, in spite of using resources more efficiently, greenhouse areas have an enormous visual and environmental impact: diversion of limited good water resources; contamina-tion due to pollutants released with over-abundant irrigation; production of plastic and mineral waste and biological by-products; contamination due to plant protec-tion chemicals and emission of ¿greenhouse¿ gases (CO2) by heating with fossil fuels in Northern countries. In addition, greenhouse production has an ¿image¿ problem: there is a general perception among European consumers that such an ¿industrial¿ production of food is non-natural and unhealthy, although in the Americas, for instance, the ¿cleanliness¿ of the production process is considered an advantage. Since, the ¿polluter pays¿ very seldom, environment-friendly production is more expensive. Therefore a large market in ¿eco-labels¿ has developed in response to consumers¿ misgivings and in the hope of recovering (part of) the costs through higher prices. However, there is little clarity about agricultural practices associated to each label and there are doubts about enforcement. This paper analyses advan-tages and draw-backs of greenhouse production, and attempts to review the items where improvement is necessary in order to ensure that greenhouse production is sustainable, yet profitable also in the future

Haalbaarheidsstudie energiebesparingsmogelijkheden met microstructuur gecoate kasdekmaterialen : eindrapport

Dit haalbaarheidsonderzoek heeft als doelstelling de toepasbaarheid van microstructuur gecoat kasdekmateriaal en het niveau van de te behalen energiebesparing in de glastuinbouw aan te tonen. Anti reflectie microstructuur (ARM) gecoate materialen hebben de hoogste lichttransmissie van de nu bekende materialen. De hogere lichttransmissie leidt tot meer toetreding van zonne-energie in de kas en dus tot energiebesparing. De extra Photosynthetic Active Radiation (PAR) kan bovendien tot een hogere productie leiden waardoor het energieverbruik per kg product verder daalt. Een dubbelglas bedekking met dit glas heeft een hogere lichttransmissie dan standaard enkelglas. Met een dubbelglas bedekking ontstaat extra warmte-isolatie waardoor energiebesparing optreedt. In dit onderzoek naar energiebesparing met behoud van productie is bovendien de combinatie onderzocht van het ARM-enkel glas met een hoog transparant energiescherm. Dit laatste heeft het voordeel dat montage in een standaard Venlokas mogelijk is zonder aanpassingen door extra constructiedelen is en dat het semi-permanent aangebracht kan worden (zoals bijvoorbeeld bij een standaard energiescherm of zoals bij de teelt van komkommers waarbij gedurende het koude seizoen bij de start van de teelt een extra folie wordt aangebracht)

Obtaining data linkage consent for children: factors influencing outcomes and potential biases

Understanding factors associated with consent for data linkage has largely focussed on adults, but parents or guardians can also be asked to consent on behalf of children for whom they are responsible. A framework for consent decision is presented, and is tested using a large nationally representative survey asking mothers to consent for both themselves and their children for two sets of records. Nearly all mothers give the same consent outcome for all their children. Consent rates are higher for education records than for health records and higher for mothers than children. Multivariate analyses suggest that minorities are generally less likely to consent, while more trust increases chances of consent. Several survey environment factors are important, with harder-to-contact respondents less likely to consent, while the presence of others and higher interviewer-respondent rapport lead to a higher chance of consent. These findings suggest potential methodologies to improve consent rates and possibly minimise bias. This is important given significant demographic differences between children across consent outcomes. However, data from a survey of 10?15 year olds in the study shows fewer differences for several important behaviours and attitudes across consent outcomes

An optimized single chain TCR scaffold relying on the assembly with the native CD3-complex prevents residual mispairing with endogenous TCRs in human T-cells.

Immunotherapy of cancer envisions the adoptive transfer of T-cells genetically engineered with tumor-specific heterodimeric α/β T-cell receptors (TCRα/β). However, potential mispairing of introduced TCRα/β-chains with endogenous β/α-ones may evoke unpredictable autoimmune reactivities. A novel single chain (sc)TCR format relies on the fusion of the Vα-Linker-Vβ-fragment to the TCR Cβ-domain and coexpression of the TCR Cα-domain capable of recruiting the natural CD3-complex for full and hence, native T-cell signaling. Here, we tested whether such a gp100(280-288)- or p53(264-272) tumor antigen-specific scTCR is still prone to mispairing with TCRα. In a human Jurkat-76 T-cell line lacking endogenous TCRs, surface expression and function of a scTCR could be reconstituted by any cointroduced TCRα-chain indicating mispairing to take place on a molecular basis. In contrast, transduction into human TCRα/β-positive T-cells revealed that mispairing is largely reduced. Competition experiments in Jurkat-76 confirmed the preference of dcTCR to selfpair and to spare scTCR. This also allowed for the generation of dc/scTCR-modified cytomegalovirus/tumor antigen-bispecific T-cells to augment T-cell activation in CMV-infected tumor patients. Residual mispairing was prevented by strenghtening the Vα-Li-Vβ-fragment through the design of a novel disulfide bond between a Vα- and a linker-resident residue close to Vβ. Multimer-stainings, and cytotoxicity-, IFNγ-secretion-, and CFSE-proliferation-assays, the latter towards dendritic cells endogenously processing RNA-electroporated gp100 antigen proved the absence of hybrid scTCR/TCRα-formation without impairing avidity of scTCR/Cα in T-cells. Moreover, a fragile cytomegalovirus pp65(495-503)-specific scTCR modified this way acquired enhanced cytotoxicity. Thus, optimized scTCR/Cα inhibits residual TCR mispairing to accomplish safe adoptive immunotherapy for bulk endogenous TCRα/β-positive T-cells

The influence of Ga+^+-irradiation on the transport properties of mesoscopic conducting thin films

We studied the influence of 30keV Ga$^+$-ions -- commonly used in focused ion beam (FIB) devices -- on the transport properties of thin crystalline graphite flake, La$_{0.7}$Ca$_{0.3}$MnO$_3$ and Co thin films. The changes of the electrical resistance were measured in-situ during irradiation and also the temperature and magnetic field dependence before and after irradiation. Our results show that the transport properties of these materials strongly change at Ga$^+$ fluences much below those used for patterning and ion beam induced deposition (IBID), limiting seriously the use of FIB when the intrinsic properties of the materials of interest are of importance. We present a method that can be used to protect the sample as well as to produce selectively irradiation-induced changes.Comment: 14 pages, 11 figures, will be published in Nanotechnology 201

Analysis of four studies in a comparative framework reveals: health linkage consent rates on British cohort studies higher than on UK household panel surveys

Background: A number of cohort studies and longitudinal household panel studies in Great Britain have asked for consent to link survey data to administrative health data. We explore commonalities and differences in the process of collecting consent, achieved consent rates and biases in consent with respect to socio-demographic, socio-economic and health characteristics. We hypothesise that British cohort studies which are rooted within the health sciences achieve higher consent rates than the UK household longitudinal studies which are rooted within the social sciences. By contrast, the lack of a specific health focus in household panel studies means there may be less selectivity in consent, in particular, with respect to health characteristics. Methods: Survey designs and protocols for collecting informed consent to health record linkage on two British cohort studies and two UK household panel studies are systematically compared. Multivariate statistical analysis is then performed on information from one cohort and two household panel studies that share a great deal of the data linkage protocol but vary according to study branding, survey design and study population. Results: We find that consent is higher in the British cohort studies than in the UK household panel studies, and is higher the more health-focused the study is. There are no systematic patterns of consent bias across the studies and where effects exist within a study or study type they tend to be small. Minority ethnic groups will be underrepresented in record linkage studies on the basis of all three studies. Conclusions: Systematic analysis of three studies in a comparative framework suggests that the factors associated with consent are idiosyncratic to the study. Analysis of linked health data is needed to establish whether selectivity in consent means the resulting research databases suffer from any biases that ought to be considered