Managing partnerships and impact on decision-making: the example of health technology assessment in genetics

For an emerging field such as Public Health Genetics, the partnerships that will be developed with stakeholders are of strategic importance, since they may affect long-term impact on policy-making. A concrete example in the field of health technology assessment in genetics was chosen to illustrate how the context in which scientific advisory bodies operate and the nature of partnerships developed over time influence the impact on decision-making at different levels, from the micro (professional) level through the meso (institutional) level to the macro (policy) level. As pointed out in the knowledge transfer literature, impact is not only reflected by instrumental use of knowledge, but also by problem-framing and strategic use of knowledge. Solid partnerships at the micro level, with researchers and health care professionals, are essential to build credibility and trust, and they lay the groundwork for contextualized and relevant advice and potential impact at the policy level. Even though maintaining the necessary critical distance with respect to all stakeholders is easier for institutions that are at arm's length from government, achieving the right balance between an institution's independence and service relationship is a real challenge.     

Comparing Dichromate Oxidation and Size Exclusion Chromatography of Dissolved Carbohydrates

Standardised methods are used to characterise the pulp or cellulosic material for its alkali resistance and alkali solubility. Today, pulp is usually characterised by its solubility in sodium hydroxide. The characterisation test was based on the treatment of pulp with sodium hydroxide solution of a defined concentration, according to a specified procedure. The dissolved organic matter was then determined by dichromate oxidation. The results obtained by size exclusion chromatography showed that both the amount and the molecular weight of the dissolved carbohydrates vary when investigating solubility and α-cellulose content of pulps. The results show further that S₁₈ values obtained by dichromate oxidation are overestimated when characterising pulps containing higher amounts of hemicellulose and/ or short chain cellulose, compared with results obtained by the SEC method. On the contrary, S₁₀ values are overestimated when determined by dichromate oxidation in higher alpha pulps.     

Silicon Analogues of Triarylmethanol Hosts. Inclusion Properties and Host–guest Structures: A Comparative Study

The simple triarylmethanol hosts, 2 and 4, and their silicon analogues, 1 and 3, have been studied for comparison of the formation of crystalline inclusion compounds. Clathrate formation experiments showed that replacement of the carbinol C atoms in 2 and 4 by Si atoms to give 1 and 3 resulted in a distinct increase of the capability to form inclusion compounds with organic guests, in particular with alcohols. Moreover, the naphthyl derivatives are much more efficient than the phenyl species, irrespective of the carbinol and silanol features. In order to investigate and compare the guest recognition modes and packing relations of hosts 1–4 in their crystalline inclusion compounds, 11 selected co-crystals, namely 1·DMSO (2:1), 3·EtOH (1:1), 3· i-PrOH (1:1), 3·acetone (1:1), 3·DMSO (1:1), 3·THF (1:1), 3·piperidine (1:1), 4·acetone (1:1), 4·DMSO (1:1), 4·1,4-dioxane (1:1) and 4·benzene (1:1), were studied by X-ray diffraction from single crystals. The survey contains additional 11 crystal structures from the literature and provides a detailed discussion of isostructurality relationships.Supplementary Data relevant to this publication have been deposited with the Cambridge Crystallographic Data Centre as supplementary publications nos. CCDC 274780–274790.     

Time-resolved spatially offset Raman spectroscopy for depth analysis of diffusely scattering layers

The objective of this study is to use time-resolved (TR) Raman spectroscopy, spatially offset Raman spectroscopy (SORS), and a combination of these approaches to obtain high quality Raman spectra from materials hidden underneath an opaque layer. Both TR Raman and SORS are advanced techniques that allow for an increased relative selectivity of photons from deeper layers within a sample. Time-resolved detection reduces fluorescence background, and the selectivity for the second layer is improved. By combining this with spatially offset excitation we additionally increased selectivity for deeper layers. Test samples were opaque white polymer blocks of several mm thicknesses. Excitation was carried out with a frequency-doubled Ti:sapphire laser at 460 nm, 3 ps pulse width and 76 MHz repetition rate. Detection was either with a continuous-wave CCD camera or in time-resolved mode using an intensified CCD camera with a 250 ps gate width. The Raman photons were collected in backscatter mode, with or without lateral offset. By measuring the delay of the Raman signal from the second layer (polyethylene terephthalate/PET/Arnite), the net photon migration speeds through Teflon, polythene, Delrin and Nylon were determined. Raman spectra could be obtained from a second layer of PET through Teflon layers up to 7 mm of thickness. The ability to obtain chemical information through layers of diffusely scattering materials has powerful potential for biomedical applications.     

The Role of Chloro Substituents in Solid Inclusion Formation. Crystal Structures Formed by a Bulky Hydroxy Host with Ethyl Acetate (2:1) and Cyclohexylamine (1:2) as Guest

Abstract

Two inclusion compounds of the 11-[bis(p‐chlorophenyl)hydroxymethyl]-9,10-dihydro-9,10-ethanoanthracene host (1) have been studied by X-ray diffraction in order to find an explanation of the exceptional clathrate formation ability of the present chloro-containing host as compared with that of closely related chlorine-free host analogues. Crystal data: 1·ethyl acetate (2:1), C₂₇H₂₂OCl₂·½(C₄H₈O₂), M_w = 501.45, P2_1/c, a = 8.9060(5), b = 11.1109(6), c = 25.642(1) Å, β = 99.03(1)°, Z = 4, R = 0.047 for 2029 F values with I>2σ(I); 1·cyclohexylamine (1:2), 2[C₂₉H₂₂OCI₂·2(C₆H₁₃N)], M_w = 1311.50, Pc, a = 12.144(2), b = 12.689(3), c =23.119(8) Å, β = 91.68(1)°, Z = 2, R = 0.054 for 3073 F values with I>2σ(I). Although the two solid inclusion compounds differ in host‐guest stoichiometry, space group symmetry and also in host‐guest recognition mode, both co-crystals are held together by numerous C?H…X (X = O, N or Cl) interactions, in which the chloro-substituents of 1 play a very active role. The observed frequent participation of chlorine in intermolecular interactions in these compounds suggests an ability of the (C?)Cl substituents to effectively enhance the crystal formation in the absence of more dominant forces.     

Polysulfonylamine. XL Darstellung von Silber(I)-disulfonylamid-Acetonitril-Komplexen. Röntgenstrukturanalytische und thermochemische Charakterisierung von Tetraacetonitrilsilber(I)-bis(dimesylamido)argentat(I) und von (1,1,3,3-Tetraoxo-1,3,2-benzodithiazolido)acetonitrilsilber(I)

Polysulfonyl Amines. XL. Preparation of Silver(I) Disulfonylamide Acetonitrile Complexes. Characterization of Tetraacetonitrilesilver(I) bis(dimesylamido)argentate(I) and (1,1,3,3-Tetraoxo-1,3,2-benzodithiazolido)acetonitrilesilver(I) by X-Ray Diffractometry and Thermal Analysis The following silver(I) disulfonylamides were prepared for the first time or by improved procedures: AgN(SO₂CH₃)₂ ( 2a ); AgN(SO₂C₆H₄-4-X)₂ with X = F ( 2b ), Cl ( 2c ), Br ( 2d ), CH₃ ( 2e ); silver(I) 1,2-benzenedisulfonimide AgN(SO₂)₂C₆H₄ ( 2f ). With acetonitrile, the salts 2a to 2e form (1/2) complexes AgN(SO₂R)· 2 CH₃CN ( 4a to 4e ), whereas 2f gives the (1/1) complex AgN(SO₂)₂C₆H · CH₃CN ( 4f ). The crystallographic data (at - 95°C) for the title compounds 4a and 4f are: 4a , space group C2/c, a = 1 967.6(4), b = 562.2(1), c = 2 353.0(5) pm, β = 102.21(2)°, V = 2.5440 nm³, Z = 4, D_x = 1.891 Mg m^?3; 4f , space group P2₁/m, a = 741.5(3), b = 980.4(4), c = 756.6(3) pm, β = 99.28(2)°, V = 0.5428 nm³, Z = 2, D_x = 2.246 Mg m^?3. 4a forms an ionic crystal [Ag(NCCH₃)₄]^⊕[Ag{N(SO₂CH₃)₂}₂]^? with a tetrahedrally coordinated silver atom (lying on a twofold axis) in the cation (225.3/225.7 pm for the two independent Ag? N distances, N? Ag? N 106.2—114.5°) and a linear-dicoordinated silver atom in the centrosymmetric anion (Ag? N 213.9 pm, two intraionic secondary Ag…O contacts 303.4 pm). 4f consists of uncharged molecules [C₆H₄(SO₂)₂N¹AgN²CCH₃] with crystallographic mirror symmetry (Ag? N¹ 218.8, Ag? N² 216.1 pm, N¹? Ag? N² 174.3°), associated into strands by intermolecular secondary silver-oxygen contacts (Ag…O 273.8 pm, O…Ag…O 175.6, N? Ag…O 91.9/88.2°). The thermochemical behaviour of 4f was investigated using thermogravimetry, differential scanning calorimetry (DSC), time- and temperature-resolved X-ray diffractometry (TXRD), and solution calorimetry. The desolvation process occurs in the temperature range from 60 to 200°C and appears to be complex, although no crystalline intermediate could be detected. The desolvation enthalpy at 298 K was found to be + 26.8(4) kJ mol^?1. 4a is desolvated in two steps at - 15 to 60°C and 60 to 95°C (DSC), suggesting the formation of AgN(SO₂CH₃) · CH₃CN as an intermediate.     

Molecular Recognition Based on Roof-shaped Diol Hosts. X-Ray Crystal Structures of Inclusion Compounds with Methanol, Pyridine and Toluene

Three crystalline inclusion compounds of roof-shapedtrans-11,12-bis(diaryl-hydroxymethyl)-9,10-dihydro-9,10-ethanoanthracene host molecules [where aryl is 4-methyl-phenyl (3) or4-t-butylphenyl (4)] have been studied by X-ray diffraction.The crystals of both the 3methanol (2 : 1) [a = 10.755(1),b = 11.571(1), c = 14.697(2) Å, = 75.12(1), = 89.67(1), = 87.13(1) °] and the 4-pyridine (2 : 3) compounds[a = 14.045(3), b = 14.366(3), c = 15.607(3) Å, = 91.62(1), = 103.65(1) and =116.05(1)°] are triclinic (P–1),while the 3toluene (1 : 1) complex has orthorhombic (Fddd) symmetry [a = 16.041(1), b = 25.008(1), c = 40.440(4) Å]. The host–guest interactions in both triclinic crystals are characterised by hydrogen bonds, with different patterns however. The determined crystal structures indicate a compromise between the requirement of hydrogen bonding on the one hand and close packing on the other. The highly symmetrical host framework in the toluene (1 : 1) complex of 3 seems to be the result of shape recognition, although atendency towards weak (C_methyl)H _arylinteractions [C_methyl = 3.533(7) and 3.674(6) Å] between the hosts was observed. The present roof-shaped diol hosts give excellent examples of molecular recognition by exhibiting two significantly different conformations, mostly depending on the proton donor/acceptor ability of the guest component. (O)H O intramolecular bonding between the two alcoholic groups characterises the so-called active form, whereas weaker (O)H and interactions stabilise the `inactive'conformation.     

4-Methylisocamphenilansäure und 4-(3,3,4-Trimethyl-2-exo-norbornyl)-3-buten-2-on

The synthesis of 4-methylisocamphenilanic acid (7) and of the unsaturated ketone 4-(3,3,4-trimethyl-2-exo-norbornyl)-3-buten-2-one (2), an analogue of -irone (1), are described. The preparation of2 has been accomplished by: catalyzedDiels—Alder reaction of methylcyclopentadiene and mesityl oxide, hydrogenation and isomerization of the resulting ketone mixture to theexo-ketone6, oxidation of6 to the acid7, reduction of7 to the corresponding aldehyde8 and aldol reaction of8 with acetone. The structure of the key intermediate6 was established by mass, 100 MHz¹H-NMR and¹³C-NMR spectra. The odour of2 is discussed briefly.

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Teil der Diplomarbeit vonI. Schmidmayer.

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9. Mitt.,G. Buchbauer undM. Wiltschko. J. Soc. Cosmet. Chem., im Druck.

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8. Mitt.,G. Buchbauer undE. Klissenbauer, Mh. Chem.109, 499 (1978).