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We describe a sequential multistaining protocol for immunohistochemistry, immunofluorescence and CyTOF imaging for formalin-fixed, paraffin-embedded specimens (FFPE) in the formalin gas-phase (FOLGAS), enabling sequential multistaining, independent from the primary and secondary antibodies and retrieval. Histomorphologic details are preserved, and crossreactivity and loss of signal intensity are not detectable. Combined with a DAB-based hydrophobic masking of metal-labeled primary antibodies, FOLGAS allows the extended use of CyTOF imaging in FFPE sections.

The molecular circuitry directing tissue development and homeostasis is hardwired by genetic programs but may also be subject to fine-tuning or major modification by environmental conditions. It remains unclear whether such malleability is at work-particularly in tissues directly in contact with the environment-and contributes to their optimal maintenance and resilience. The protein kinase p38α is activated by physiological cues that signal tissue damage and neoplastic transformation. Here, we found that p38α phosphorylated and thereby destabilized p63, a transcription factor essential for epidermal development. Through this regulatory mechanism, p38α limited the frequency of keratinocytes with stem cell properties and tumorigenic potential. Correspondingly, epidermal loss of p38α expression or activity promoted or correlated with carcinogenesis in mouse and human skin, respectively. Genetic mouse models revealed a tumorigenic mechanism from p38α loss through p63-mediated suppression of the matrix metalloprotease MMP13. These findings illustrate a previously uncharacterized epidermal tumor-suppressive mechanism in which stress-activated signaling induces the contraction of stem cell-like keratinocyte pools.

The asymmetric hydrogenation of tetrasubstituted olefins provides direct access to very useful biological molecules and intermediates. The development of the technology has been slow, due in part to the synthetic challenges involved in developing chiral catalysts for a successful asymmetric induction. We briefly recount the breakthroughs in functionalized and unfunctionalized tetrasubstituted olefins, from the reports of Zhou and Buchwald for functionalized and unfunctionalized substrates, respectively, to the advent of chiral phosphoramidite ligands. The main emphasis of this Perspective lies in bringing into focus the complexity and challenges of inducing an asymmetric reduction for these substrates, which includes a brief discussion of the mechanism, the latest developed chiral catalysts, and the enormous scientific opportunities that still exist in developing “go to” catalyst systems for the various substrate types.

Mast cell (MC) activation through the high-affinity IgE receptor FcεRI leads to the release of mediators involved in immediate-type allergic reactions. Although Abs against the tetraspanins CD63 and CD81 inhibit FcεRI-induced MC degranulation, the intrinsic role of these molecules in FcεRI-induced MC activation is unknown. In MCs, CD63 is expressed at the cell surface and in lysosomes (particularly secretory lysosomes that contain allergic mediators). In this study, we investigated the role of CD63 in MC using a CD63 knockout mouse model. CD63-deficiency did not affect in vivo MC numbers and tissue distribution. Bone marrow–derived MC developed normally in the absence of CD63 protein. However, CD63-deficient bone marrow–derived MC showed a significant decrease in FcεRI-mediated degranulation, but not PMA/ionomycin-induced degranulation, as shown by β-hexosaminidase release assays. The secretion of TNF-α, which is both released from granules and synthesized de novo upon MC activation, was also decreased. IL-6 secretion and production of the lipid mediator leukotriene C4 were unaffected. There were no ultrastructural differences in granule content and morphology, late endosomal/lysosomal marker expression, FcεRI-induced global tyrosine phosphorylation, and Akt phosphorylation. Finally, local reconstitution in genetically MC-deficient Kitw/w-v mice was unaffected by the absence of CD63. However, the sites reconstituted with CD63-deficient MC developed significantly attenuated cutaneous anaphylactic reactions. These findings demonstrate that the absence of CD63 results in a significant decrease of MC degranulation, which translates into a reduction of acute allergic reactions in vivo, thus identifying CD63 as an important component of allergic inflammation.

Functionalized plant oils such as epoxidized soybean oil (ESO) are widely used in plastic industries as additives and are available for more value-added applications. Pressure-sensitive adhesive (PSA) derived from petroleum feedstocks has a huge market ranging from tapes to packaging. Here we show a sustainable PSA derived from ESO/dihydroxyl soybean oil (DSO)/rosin ester (Sylvalite) via UV-initiated copolymerization. The ether crosslinks derived from cationic polymerization of ESO and copolymerization between ESO and DSO (or rosin ester) were demonstrated using 1H NMR, 2D 1H–1H COSY NMR, electrospray ionization mass spectrometry and thermal analyses (differential scanning calorimetry and thermogravimetric analysis). The PSA was formulated by modulating the ratio of ESO/DSO/rosin ester to achieve high performance. At a UV dose of 5.1–5.4 J cm−2 and 0.3–3% (w/w) of a photoinitiator, i.e. [4-(2-hydroxy-1-tetradecyloxy)-phenyl]phenyliodonium hexafluoroantimonate, the PSA at a ratio (by weight) of 1:1:0.7 (ESO/DSO/rosin ester) recorded the highest peel and loop tack strength, which was comparable to a commercial PSA, Scotch Magic Tape, and showed much stronger shear strength (>30 000 min) than the commercial tape (10 000 min). The high-shear rheological behavior and excellent thermal stability of the PSA were also demonstrated. © 2012 Society of Chemical Industry

The reactivity of the bis-NHC complex LPdIVCl4 (L = κ2-[R-NHCCH2NHC-R] with R = C14H29) in chlorinations and oxidations of organic substrates was considerably increased in the presence of pyridine. For alkene chlorinations, this effect was due to the in situ formation of highly reactive LPdIVCl3(py)+, which was able to transfer Cl+ to the C═C bond in a ligand-mediated process (devoid of π complexation), which did not require py dissociation. The enhanced reactivity in the presence of pyridine also extended to the oxidation of secondary and benzylic alcohols under mild conditions in a reaction where py served as a base, broadening the known scope of reactivity for PdIV complexes. LPdIVCl3(py)+ could be formed from Cl–/py exchange or from the oxidation of LPdIICl(py)+ by Cl2. Taking advantage of the enhanced reactivities that pyridine coordination imparted on both PdII and PdIV complexes allowed for the catalytic chlorination of styrene with LPdIVCl4 as a sacrificial oxidant, thereby establishing the princi...

Toxic solvent and strong acid catalysts causing environmental issues have been mainly used for ring-opening of epoxidized oleochemicals. Here, we demonstrated that magnesium stearate (Mg-stearate) was a high efficient catalyst for solvent-free ring-opening of epoxidized methyl oleate, a model compound of midchain epoxide. Mg-stearate resulted in the highest yield (95%) and conversion rate (99%) toward midchain alkoxyesters under the same conditions (160 °C, 12 h) superior to other fatty acid derivatives such as a Lewis acid (lithium and sodium stearate) and Brønsted acid (stearic acid). Based on this chemical study, we synthesized biogrease and thermoplastic using epoxidized soybean oil (ESO) and Mg-stearate via one-pot, solvent-free, and purification-free process. Mg-stearate played a significant role as a reactant for epoxide ring-opening and as a thickener when excess loading rate was used; viscosity increased from 1800 to 4500 Pa·s at 25 °C when ESO:Mg-stearate increased from 1:1 equiv to 1:2, then behaved like thermoplastics (T(g) = -27 °C, T(m) = 90 °C) with 1:4.

Methylene-bridged resorcin[4]arenes featuring electrochemically active and hydrophilic viologen units, chemically attached to their ‘rim’ regions, and a variety of pendent groups (‘feet’) have been synthesized. These compounds were designed to act as electrochemically active cavitands and especially as guests in mycobacteria-l channel proteins (channel blockers).

Photoelectron yields and energy resolutions of bare and packed LaBr3:Ce crystals are determined as function of proton irradiation dose, cerium concentration and sample height from 1 mm to 2 inch. A simple model is employed to predict light yield for Oslash3" times 3" size crystals, and to assess the quality of packaging. The effect of proton exposure on scintillation yield and resolution of LaBr3: Ce is investigated. Intense proton irradiation does not deteriorate yield or resolution. It also does not affect thermoluminescence behavior.

Both homo- and heterosequence m-phenylene ethynylene oligomers are synthesized using a conceptually simple iterative solid-phase strategy. Oligomers are attached to Merrifield's resin through a known triazene-type linkage. The phenylene ethynylene molecular backbone is constructed through a series of palladium-mediated cross-coupling reactions. The strategy employs two types of monomers that bear orthogonal reactivity, one being a monoprotected bisethynyl arene and the other being a 3-bromo-5-iodo arene. The catalyst conditions are tailored to the requirements of each monomer type. The monoprotected bisethynyl arene is coupled to the growing chain in 2 h at room temperature using a Pd(I) dimer precatalyst ((t)Bu3P(Pd(mu-Cl)(mu-2-methyl allyl)Pd)P(t)Bu3) in conjunction with ZnBr2 and diisopropylamine. In alternate steps, the resin is deprotected in situ with TBAF and coupled to the 3-bromo-5-iodo arene using the iodo selective Pd(tri-2-furylphosphine)4 catalyst in conjunction with CuI and piperidine; this reaction is also completed in 2 h at room temperature. These cross-coupling events are alternated until an oligomer of the desired length is achieved. The oligomer is then cleaved from the resin using CH(2)I(2)/I(2) at 110 degrees C and purified using preparatory GPC. Using this method, a series of homo- and heterosequence oligomers up to 12 units in length in excellent yield and purity were synthesized on the 100 mg scale. Longer oligomers were attempted; however, deletion sequences were found in oligomers longer than 12 units.

High-affinity IgE receptor (FcepsilonRI) cross-linking on mast cells (MCs) induces secretion of preformed allergy mediators (degranulation) and synthesis of lipid mediators and cytokines. Degranulation produces many symptoms of immediate-type allergic reactions and is modulated by adhesion to surfaces coated with specific extracellular matrix (ECM) proteins. The signals involved in this modulation are mostly unknown and their contribution to allergic reactions in vivo is unclear. Here we report the generation of monoclonal antibodies that potently suppress FcepsilonRI-induced degranulation, but not leukotriene synthesis. We identified the antibody target as the tetraspanin CD63. Tetraspanins are membrane molecules that form multimolecular complexes with a broad array of molecules including ECM protein-binding beta integrins. We found that anti-CD63 inhibits MC adhesion to fibronectin and vitronectin. Furthermore, anti-CD63 inhibits FcepsilonRI-mediated degranulation in cells adherent to those ECM proteins but not in nonadherent cells. Thus the inhibition of degranulation by anti-CD63 correlates with its effect on adhesion. In support of a mechanistic linkage between the two types of inhibition, anti-CD63 had no effect on FcepsilonRI-induced global tyrosine phosphorylation and calcium mobilization but impaired the Gab2-PI3K pathway that is known to be essential for both degranulation and adhesion. Finally, we showed that these antibodies inhibited FcepsilonRI-mediated allergic reactions in vivo. These properties raise the possibility that anti-CD63 could be used as therapeutic agents in MC-dependent diseases.

Human antigen-presenting cells (APCs) bind monomeric immunoglobulin E (IgE) via the high-affinity IgE receptor, Fc epsilon RI. Surface expression of this trimeric structure is strongly associated with the atopic status of the donors, and maximal levels are observed on Langerhans cells (LC) and inflammatory dendritic epidermal cells (IDEC) in atopic dermatitis (AD). Although intracellular expression of the Fc epsilon RI alpha-chain is induced by interleukin-4 (IL-4), the upregulation of surface levels on dendritic cells (DC) from atopics is due to enhanced expression of the Fc epsilon RI gamma-chain and stabilization by binding of its ligand IgE. A characteristic function of Fc epsilon RI-bearing APCs is the specific uptake and processing of IgE-bound allergens, which is followed by T-cell stimulation. In AD, DC-mediated presentation of aeroallergens penetrating the epidermis is thought to induce an IgE-mediated, delayed-type hypersensitivity reaction. In addition, different Fc epsilon RI-bearing APC subsets in AD skin might regulate inflammatory processes through the production of Th1/Th2-polarizing signals, proinflammatory cytokines, chemokines, and factors that are involved in the induction of tolerance.

A systematic study of alkyne metathesis catalyzed by trialkoxymolybdenum(VI) alkylidyne complexes is reported, in which substrate functional groups, alkynyl substituents, and catalyst ligands are varied. Sterically hindered trisamidomolybdenum(VI) propylidyne complex 5 was prepared conveniently through a previously communicated reductive recycle strategy. Alcoholysis of 5 with various phenols/alcohols provides a set of active catalysts for alkyne metathesis at room temperature, among which the catalyst with p-nitrophenol as ligand shows the highest catalytic activity and is compatible with a variety of functional groups and solvents. A key finding that enabled the use of highly active molybdenum(VI) catalysts is replacement of the commonly used propynyl substituents on the starting alkyne substrates with butynyl groups. Under reduced pressure using 1,2,4-trichlorobenzene as an involatile solvent, the alkyne metathesis of butynyl substituted compounds proceeds well at 30 degrees C providing high yields (83%-97%) of dimers. Rationalization of the special role played by butynyl substrates is discussed.

Cyclic cis-enediynes are readily prepared by a two-step one-pot procedure. The first step is the copper-catalyzed addition of α,ω-diynes to manganese carbyne complexes to give intermediate bis(alkynylcarbene) complexes that rearrange to enediyne complexes below room temperature. In the second step, the free enediyne is released from manganese by photolysis, copper-catalyzed air oxidation, or stoichiometric Cu(II) oxidation. These new procedures have been applied to a variety of five-, six-, and seven-membered-ring cyclic enediynes containing a range of ether, ester, and ketone functional groups.

Dimerization of the alkynylcarbene complex (C5H4Me)(CO)2MnC(Tol)CCTol (10) occurred at 65 °C to give a mixture of E- and Z-enediyne complexes [(C5H4Me)(OC)2Mn]2[η2,η2-TolCC(Tol)CC(Tol)CCTol] (13). Thermolysis of alkynye complexes 10 at higher (100 °C) temperature led to the formation of manganese-free E- and Z-enediynes TolCC(Tol)CC(Tol)CCTol (14-E and 14-Z). Attempted synthesis of the tethered bis-(alkynylcarbene) complex Cp(OC)2MnC(Ph)CCCH2CH2CH2CCC(Ph)Mn(CO)2Cp led instead to the cyclic enediyne complex [Cp(OC)2Mn]2[η2,η2-PhCCC(CH2CH2CH2)CCCPh] (19), from which the metal-free enediyne 1,2-bis(phenylethynyl)cyclopentene (20) was released by thermolysis at 90 °C.

Hydride abstraction from C(5)Me(5)(CO)(2)Re(eta(2)-PhC triple bond CCH(2)Ph) (1) gave a 3:1 mixture of eta(3)-propargyl complex [C(5)Me(5)(CO)(2)Re(eta(3)-PhCH-C triple bond CPh)][BF(4)] (5) and eta(2)-1-metalla(methylene)cyclopropene complex [C(5)Me(5)(CO)(2)Re(eta(2)-PhC-C=CHPh)][BF(4)] (6). Observation of the eta(2)-isomer requires 1,3-diaryl substitution and is favored by electron-donating substituents on the C(3)-aryl ring. Interconversion of eta(3)-propargyl and eta(2)-1-metalla(methylene)cyclopropene complexes is very rapid and results in coalescence of Cp (1)H NMR resonances at about -50 degrees C. Protonation of the alkynyl carbene complex C(5)Me(5)(CO)(2)Re=C(Ph)C triple bond CPh (22) gave a third isomer, the eta(3)-benzyl complex [C(5)Me(5)(CO)(2)Re[eta(3)(alpha,1,2)-endo,syn-C(6)H(5)CH(C triple bond CC(6)H(5))]][BF(4)] (23) along with small amounts of the isomeric complexes 5 and 6. While 5 and 6 are in rapid equilibrium, there is no equilibration of the eta(3)-benzyl isomer 23 with 5 and 6.

Thermolysis of the alkynylcarbene complex Cp*(CO)2ReC(Ph)13C⋮13CTol (5) at 120 °C resulted in rapid equilibration (t1/2 = 33 min) to a 1:1 mixture of 5 and Cp*(CO)2Re13C(Tol)13C⋮CPh (7) via a [1,3]-rhenium shift. Extended thermolysis of this mixture provided the CH insertion products {η5:η2-[C5(CH3)4CH213CH(Tol)13C⋮CPh]}Re(CO)2 (8) and {η5:η2-[C5(CH3)4CH2CH(Ph)13C⋮13CTol]}Re(CO)2 (9). Thermolysis of the symmetrically substituted alkynylcarbene complex Cp*(CO)2ReC(Ph)C⋮CPh (6) produced the CH insertion product {η5:η2-[C5(CH3)4CH2CH(Ph)C⋮CPh]}Re(CO)2 (10). The CH insertion of Cp*(CO)2ReC(Ph)C⋮CC6D5 (6-HD) was monitored at low conversion before complete equilibration with Cp*(CO)2ReC(C6D5)C⋮CPh (6-DH) occurred. An excess of {η5:η2-[C5(CH3)4CH2CH(C6D5)C⋮CPh]}Re(CO)2 (13-HD) over {η5:η2-[C5(CH3)4CH2CH(Ph)C⋮CC6D5]}Re(CO)2 (13-DH) provides evidence for site-selective CH insertion of the remote alkyne carbon into the CH bond of a Cp* methyl group.

Addition of PPh 2 CH 3 to the alkynyl carbene complex Cp(CO) 2 ReC(Tol)(CCPh) ( 1a ) led to formation of the dihydrophospholium complex Cp(CO) 2 Re[CC(Ph)PPh 2 CH 2 CH(Tol)] ( 4 ). When the reaction was monitored by low temperature NMR spectroscopy, initial phosphine addition to the carbene carbon atom of 1a to give σ-propargyl complex Cp(CO) 2 ReC(PPh 2 CH 3 )(Tol)CCPh ( 5 ) was observed at −78°C. Upon warming to −20°C, 5 rearranged to the σ-allenyl complex Cp(CO) 2 Re(Tol)CCC(Ph)(PPh 2 CH 3 ) ( 6 ) via phosphine dissociation and readdition. Upon further warming to room temperature, 6 rearranged to 4 . A protonation-deprotonation mechanism for the conversion of 6 to 4 is supported by the observation that reaction of 6 with DOTf produces the cationic allene complex Cp(CO) 2 Re[η 2 -2,3-(Tol)DCCC(Ph)(PPh 2 CH 3 )]OTf ( 11 - d ), which is converted to 4 - d upon treatment with KO- t -Bu. The reaction of 1a with Ph 2 PCHCH 2 led to the formation of the cyclopropane Cp(CO) 2 Re[CC(Ph)PPh 2 CHCH 2 C(Tol)] ( 8 ).

Amphiphilic reduced graphene oxide is obtained by oleo-functionalization with epoxidized methyl oleate (renewable feedstock) using a green process. The excellent diverse solvent-dispersivity of the oleo-reduced amphiphilic graphene and its reduction chemistry are confirmed in this study. Oleo-reduction of amphiphilic graphene is amenable to industrially viable processes to produce future graphene-based polymer composites and systems.

This Article describes the preparation and isolation of novel octahedral CH(2)-bridged bis-(N-heterocyclic carbene)palladium(IV) tetrachlorides of the general formula LPd(IV)Cl(4) [L = (NHC)CH(2)(NHC)] from LPd(II)Cl(2) and Cl(2). In intermolecular, nonchelation-controlled transformations LPd(IV)Cl(4) reacted with alkenes and alkynes to 1,2-dichlorination adducts. Aromatic, benzylic, and aliphatic C-H bonds were converted into C-Cl bonds. Detailed mechanistic investigations in the dichlorinations of alkenes were conducted on the 18VE Pd(IV) complex. Positive solvent effects as well as kinetic measurements probing the impact of cyclohexene and chloride concentrations on the rate of alkene chlorination support a Pd(IV)-Cl ionization in the first step. Product stereochemistry and product distributions from various alkenes also support Cl(+)-transfer from the pentacoordinated Pd(IV)-intermediate LPd(IV)Cl(3)(+) to olefins. 1-Hexene/3-hexene competition experiments rule out both the formation of π-complexes along the reaction coordinate as well as in situ generated Cl(2) from a reductive elimination process. Instead, a ligand-mediated direct Cl(+)-transfer from LPd(IV)Cl(3)(+) to the π-system is likely to occur. Similarly, C-H bond chlorinations proceed via an electrophilic process with in situ formed LPd(IV)Cl(3)(+). The presence of a large excess of added Cl(-) slows cyclohexene chlorination while the presence of stoichiometric amounts of chloride accelerates both Pd(IV)-Cl ionization and Cl(+)-transfer from LPd(IV)Cl(3)(+). (1)H NMR titrations, T1 relaxation time measurements, binding isotherms, and Job plot analysis point to the formation of a trifurcated Cl(-)···H-C bond in the NHC-ligand periphery as a supramolecular cause for the accelerated chemical events involving the metal center.

The electron-withdrawing SO2CF3 substituent of Cp(CO)2ReC(Tol)(C⋮CC6H4-p-SO2CF3) (1d) greatly accelerates rearrangement via a [1,3]-rhenium shift. The [1,3]-rhenium shift is proposed to proceed via an 18-electron dehydrometallacyclobutadiene intermediate formed by alkyne coordination concerted with an η5−η3 Cp ring slip.

Treatment of de-epithelialized human corneas with riboflavin (RF) + long-wavelength ultraviolet light (UVA; RFUVA) increases corneal stroma tensile strength significantly. RFUVA treatment retards the progression of keratoconus, perhaps by cross-linking of collagen molecules, but exact molecular mechanisms remain unknown. Research described here tested possible chemical mechanisms of cross-linking.Corneas of rabbits and spiny dogfish sharks were de-epithelialized mechanically, subjected to various chemical pretreatments, exposed to RFUVA, and then subjected to destructive tensile stress measurements. Tensile strength was quantified with a digital force gauge to measure degree of tissue cross-linking.For both rabbit and shark corneas, RFUVA treatment causes significant cross-linking by mechanism(s) that can be blocked by the presence of sodium azide. Conversely, such cross-linking is greatly enhanced in the presence of deuterium oxide (D(2)O), even when RF is present at only one tenth the currently used clinical concentrations. Blocking carbonyl groups preexisting in the stroma with 2,4-dinitrophenylhydrazide or hydroxylamine blocks essentially all corneal cross-linking. In contrast, blocking free amine groups preexisting in the stroma with acetic anhydride or ethyl acetimidate does not affect RFUVA corneal cross-linking. When both carbonyl groups are blocked and singlet oxygen is quenched, no RFUVA cross-linking occurs, indicating the absence of other cross-linking mechanisms.RFUVA catalyzes cross-linking reactions that require production of singlet oxygen ((1)O(2)), whose half-life is extended by D(2)O. Carbonyl-based cross-linking reactions dominate in the corneal stroma, but other possible reaction schemes are proposed. The use of D(2)O as solution media for RF would enable concentration decreases or significant strength enhancement in treated corneas.

The XEUS petals encompass the optical bench structure of the stand alone X-Ray Optical Units (XOU) based on the high performance and light weight Silicon Pore Optics technology. The performance aspects under consideration of the design drivers, the related trade offs (e.g. mechanical concepts, material selection, XOU butting efficiency etc.) and the current development activities wrt. the design, manufacturing, assembly and the functional and environmental test verification approach of the Form Fit Function Model are described in this paper. Special emphasis is given to the critical external optical and mechanical interfaces coherent to the mission design, e.g. the Mirror S/C frame work structure and the Detector S/C. The technology program is based on the heritage achieved within the context of the XMM/Newton telescope development. The investigations of the correlated programmatic aspects towards the FM production by application of effective robot system supported assembly procedures shall be illustrated.

New astronomical science missions demand X-ray telescopes with an angular resolution better than 5" and effective areas of up to 5 m2 at 1 keV. Traditional technologies like nickel electro-forming or polished glass surfaces lead to long and heavy structures, which require prohibitive mass resources to achieve the required large collecting area. To overcome this problem an entirely novel technology using silicon wafers has been developed resulting in pore X-ray optics, which form very light, stiff and modular structures. The suitability of silicon wafers to be used as high quality optical material has been demonstrated and semiconductor industry have developed methods to structure the wafers such, that they can be assembled into segments of Wolter-I optics. For the assembly of these, so called High Performance Pore Optics (HPO), we have developed an automated production robot. The assembly process and the required metrology is described in detail and experimental methods are shown, which allow to assess the quality of the HPOs during production and to predict their performance when measured in synchrotron radiation facilities.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The characteristics of the latest generation of assembled silicon pore X-ray optics are discussed in this paper. These very light, stiff and modular high performance pore optics (HPO) have been developed [1] for the next generation of astronomical X-ray telescopes, which require large collecting areas whilst achieving angular resolutions better than 5 arcseconds. The suitability of 12 inch silicon wafers as high quality optical mirrors and the automated assembly process are discussed elsewhere in this conference. HPOs with several tens of ribbed silicon plates are assembled by bending the plates into an accurate cylindrical shape and directly bonding them on top of each other. The achievable figure accuracy is measured during assembly and in test campaigns at X-ray testing facilities like BESSY-II and PANTER. Pencil beam measurements allow gaining information on the quality achieved by the production process with high spatial resolution. In combination with full beam illumination a complete picture of the excellent performance of these optics can be derived. Experimental results are presented and discussed in detail. The results of such campaigns are used to further improve the production process in order to match the challenging XEUS requirements [2] for imaging resolution and mass.

Producing the next generation of X-ray optics, both for large astrophysics missions and smaller missions such as planetary exploration, requires much lower mass and therefore much thinner mirrors. The use of pore structures allows very thin mirrors in a stiff structure. Over the last few years we have been developing ultra-low mass pore optics based on microchannel plate technology in glass, resulting in square, open-core glass fibres in a concentric geometry. The surface roughness inside the pores can be as low as 0.5 nm due to the extreme stretching of the surface during production. We show how improvements in the production process have led to an improved quality of the fibers and the quality of stacking the fibers in the required geometry. To achieve een higher imaging quality as required for XEUS we have developed in parallel a novel pore optics technology based on silicon wafers. The production process of silicon wafers is extremely optimised by the semiconductor industry, leading to optical qualities that are sufficient for high-resolution X-ray focussing. We have developed the technology to stack these wafers into accurate X-ray optics, set up automated assembly facilities for the production of these stacks and present very promising X-ray test results of 5.3 arcsec HEW from single reflection off such a stack, showing the great potential of this technology for XEUS and other high-resolution low mass X-ray optics.

The next generation astronomical X-ray telescopes (e.g. XEUS) require extremely large collecting area (10 m2) in combination with good angular resolution (5 arcsec). The existing technologies such as polished glass, nickel electroforming and foil optics would lead to excessively heavy and expensive optics, and/or are not able to produce the required large area or resolution. We have developed an entirely novel technology for producing X-ray optics which results in very light, stiff and modular optics which can be assembled into almost arbitrarily large apertures, and which are perfectly suited for XEUS. The technology makes use of commercially available silicon wafers from the semiconductor industry. The latest generation silicon wafers have a surface roughness that is sufficiently low for X-ray reflection, are planparallel to better than a micrometer, have almost perfect mechanical properties and are considerably cheaper than other high-quality optical materials. The wafers are bent into an accurate cone and assembled to form a light and stiff pore structure with pores of the order of a millimeter. The resulting modules form a small segment of a Wolter-I optic, and are easily assembled into an optic with large collecting area. We present the production principle of these silicon pore optics, the facilities that have been set up to produce these modules and experimental results showing the excellent performance of the first modules that have been produced. With further improvement we expect to be able to match the XEUS requirements for imaging resolution and mass.

In contrast to mast cells and basophils, the high-affinity IgE receptor (Fc(epsilon)RI) on monocytes and dendritic cells (DC), including epidermal Langerhans cells, is not constitutively expressed and lacks the beta-chain. Fc(epsilon)RI is upregulated on Langerhans cells of atopic individuals, particularly in atopic dermatitis skin. Although Fc(epsilon)RI provides IgE-mediated antigen focusing on monocytes and DC/Langerhans cells, its relevance for cell activation remains elusive, and the transcription factors regulating Fc(epsilon)RI-induced genes are unknown. We show that NF-kappaB, known to regulate genes essential for inflammatory responses and DC differentiation and function, is activated upon Fc(epsilon)RI ligation in primary human monocytes and DC. In Langerhans cells isolated from epidermis, NF-kappaB activation is restricted to donors expressing high Fc(epsilon)RI amounts. Fc(epsilon)RI-induced NF-kappaB complexes in monocytes and DC contain p50 and p65, but no other NF-kappaB subunits despite increased RelB expression during differentiation. NF-kappaB activation is preceded by serine phosphorylation and degradation of its inhibitory protein IkappaB-alpha without involving other IkappaB proteins. Finally, we show that Fc(epsilon)RI ligation on monocytes and DC leads to synthesis and release of tumor necrosis factor-alpha and monocyte chemoattractant protein-1, which is decreased by two mechanistically distinct inhibitors of NF-kappaB activation. Thus NF-kappaB activation represents a novel mechanism by which Fc(epsilon)RI on monocytes and DC potentially controls inflammatory reactions.

Dimerization of the alkynylcarbene complex Cp(CO)(2)Re=C(Tol)C(triple bond)CCH(3) (8) occurs at 100 degrees C to give a 1.2:1 mixture of enediyne complexes [Cp(CO)(2)Re](2)[eta(2),eta(2)-TolC(triple bond)CC(CH(3))=C(CH(3))C(triple bond)CTol] (10-Eand 10-Z), showing no intrinsic bias toward trans-enediyne complexes. The cyclopropyl-substituted alkynylcarbene complex Cp(CO)(2)Re=C(Tol)C(triple bond)CC(3)H(5) (11) dimerizes at 120 degrees C to give a 5:1 ratio of enediyne complexes [Cp(CO)(2)Re](2)[eta(2),eta(2)-TolC(triple bond)C(C(3)H(5))C=C(C(3)H(5))C(triple bond)CTol] (12-E and 12-Z); no ring expansion product was observed. This suggests that if intermediate A formed by a [1,1.5] Re shift and having carbene character at the remote alkynyl carbon is involved, then interaction of the neighboring Re with the carbene center greatly diminishes the carbene character as compared with that of free cyclopropyl carbenes. The tethered bis-(alkynylcarbene) complex Cp(CO)(2)Re=C(Tol)C(triple bond)CCH(2)CH(2)CH(2)C(triple bond)CC(Tol)= Re(CO)(2)Cp (13) dimerizes rapidly at 12 degrees C to give the cyclic cis-enediyne complex [Cp(CO)(2)Re](2)[eta(2),eta(2)-TolC(triple bond)CC(CH(2)CH(2)CH(2))=CC(triple bond)CTol] (15). Attempted synthesis of the 1,8-disubstituted naphthalene derivative 1,8-[Cp(CO)(2)Re=C(Tol)C(triple bond)C](2)C(10)H(6) (16), in which the alkynylcarbene units are constrained to a parallel geometry, leads to dimerization to [Cp(CO)(2)Re](2)(eta(2),eta(2)-1,2-(tolylethynyl)acenaphthylene] (17). The very rapid dimerizations of both 13 and 16 provide compelling evidence against mechanisms involving cyclopropene intermediates. A mechanism is proposed which involves rate-determining addition of the carbene center of A to the remote alkynyl carbon of a second alkynylcarbene complex to generate vinyl carbene intermediate C, and rearrangement of C to the enediyne complex by a [1,1.5] Re shift.

We have performed precise measurements of x-ray absorption constants for all the thin films comprising CCD gate structure, namely, phosphorous doped polysilicon, silicon dioxide, and silicon nitride. X-ray absorption of these films shows large oscillations around the corresponding absorption edges: nitrogen K, oxygen K, silicon L and K. As a result, quantum efficiency of a CCD in the soft x-ray range deviates significantly from the generally assumed simple model predictions. In order to cover the range of energies from 60 eV to 3000 eV transmission measurements were performed at several synchrotron beamlines at ALS, PTB BESSY, SRC. A model of the CCD response with near edge x-ray absorption structure taken into account predicts a very complicated shape of the energy dependence of the quantum efficiency around silicon and oxygen absorption edges. Experimental measurements of CCD quantum efficiency relative to a calibrated detector were performed at BESSY for both frontside illuminated and backside illuminated CCDs for energies around the oxygen absorption edge. Experimental results were found to be in a good agreement with our model.

IgE-bearing human epidermal Langerhans cells (LC) are suspected of playing a key role in the pathogenesis of atopic dermatitis (AD). We and others have shown that these cells bind IgE via the high affinity receptor Fc epsilon RI (FceRI) (1, 2). Recent findings have shown that the expression of this receptor on LC and related dendritic cells in the skin is highly upregulated in lesions skin of AD when compared with nonatopic individuals and this is correlated to a high IgE serum levels (3). Functionally, LC from normal skin differ from those of atopic skin in terms of calcium mobilization upon receptor ligation (4). Beside qualitative alterations in the activation cascade, unresponsiveness also may be related to inefficient triggering in normal LC displaying low amounts of receptors. Thus, the variations in receptor expression may be crucial for the outcome of the signal transduction initiated by FceRI-cross-linking on LC, implying the need of a better understanding of the mechanisms regulating the receptor display on LC. However, detailed functional, biochemical and molecular biological analysis of FceRI + LC is hampered by the limited number of LC routinely obtained from skin biopsies or surgical samples. Recently several cytokines, especially granulocyte/macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-α), have been identified that speed the development of dendritic cells from blood and bone marrow precursors in suspension cultures (5, 6, 7, 8, 9). We took advantage of this progress to establish a model for the study of the regulation of FceRI on LC and other dendritic cells.

A convenient synthesis of trisamido molybdenum(VI) alkylidyne complexes has been developed, in which the key step is the addition of a geminal dichloride to a trisamido molybdenum(III) complex in the presence of magnesium to continuously recycle unwanted side product 4, selectively generating the desired alkylidyne complexes in high yield.

The polymerization pathways of epoxidized and hydroxylated triglycerides with phosphoric acid (H3PO4) were investigated using model reactions. Involved epoxides and diols were derived from oleic acid methyl ester, which was easily monitored by one- and two-dimensional nuclear magnetic resonance (NMR) techniques as well as electrospray ionization mass spectroscopy (ESI-MS). Phosphoric acid played two key functions: (a) as a Bronsted acid catalyst that activated the epoxide toward nucleophilic attack by the diol, thus generating ether (C–O–C) cross-linkages; and (b) as a reaction partner establishing phosphate ester linkages [(RO)2(O)P–O–C, R = C or H]. In studies with 18O labeled diol, phosphate esters formed exclusively from H3PO4 and epoxide without incorporation of diol whereas diols acted as polymerization initiators in polyether formations.

We perform precise measurements of the x-ray transmission of the thin films comprising CCD gate structure, namely, phosphorus doped polysilicon, silicon dioxide, and silicon nitride. The x-ray transmission of these films shows large oscillations with small changes in energy in the vicinity of the following absorption edges: nitrogen K (400 eV), oxygen K (536 eV), silicon L and K (100 and 1840 eV, respectively). As a result, quantum efficiency of a CCD in the soft x-ray range deviates significantly from simple model predictions based on Henke et al. (1993) mass absorption coefficients. The measurements covered the range of energies from 60 to 3000 eV, using synchrotron beamlines at the Advanced Light Source (ALS; Berkeley), Physikalisch-Technische Bundesanstalt BESSY (Berlin), the Synchrotron Radiation Center (SRC; University of Wisconsin-Madison). Our model of the CCD response includes near edge x-ray absorption structure and predicts a very complicated shape of the energy dependence of the quantum efficiency around silicon and oxygen absorption edges. Experimental measurements of CCD quantum efficiency relative to a calibrated detector at the BESSY synchrotron confirmed our model predictions for both frontside and backside illuminated CCDs.