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The incorporation of heteroatoms into polycyclic aromatic hydrocarbons can alter their optical and electronic properties. Here, we report the synthesis and characterization of a series of N,N′-diaryl diazadioxatetrahydropentacenes (4a–e) as well as related N-phenyl azatrioxatetrahydropentacene and triazatetrahydrotetracene derivatives (5, 6) to investigate their photophysical properties and solid-state organization. These compounds were prepared from readily available compounds via a concise approach involving copper-catalyzed aryl amination, followed by nucleophilic aromatic substitution. The compounds display bright luminescence in solution and in the solid state and strong solvatochromism. Single-crystal X-ray diffraction of N,N′-aryl diazadioxatetrahydropentacenes (4b–d) revealed that all the compounds possessed nearly planar polycyclic aromatic systems with the pendant aryl groups nearly orthogonal to the pentacyclic core. Nonetheless, different substituents on the pendant aryl groups resulted in differences in photophysical properties because of differences in molecular geometries and solid-state packing. Interestingly, the N,N′-aryl diazadioxatetrahydropentacene bearing 2,6-dimethylphenyl groups attached to the nitrogen atoms (4d) gave two different polymorphs from the same solvent system, constituting a relatively rare example of concomitant polymorphism for such a rigid structure.

Biofilms are communities of self-enmeshed bacteria in a matrix of exopolysaccharides. The widely distributed human pathogen and commensal Escherichia coli produces a biofilm matrix composed of phosphoethanolamine (pEtN)-modified cellulose and amyloid protein fibers, termed curli. The addition of pEtN to the cellulose exopolysaccharide is accomplished by the action of the pEtN transferase, BcsG, and is essential for the overall integrity of the biofilm. Here, using the synthetic co-substrates p-nitrophenyl phosphoethanolamine and β-d-cellopentaose, we demonstrate using an in vitro pEtN transferase assay that full activity of the pEtN transferase domain of BcsG from E. coli (EcBcsGΔN) requires Zn2+ binding, a catalytic nucleophile/acid-base arrangement (Ser278/Cys243/His396), disulfide bond formation, and other newly uncovered essential residues. We further confirm that EcBcsGΔN catalysis proceeds by a ping-pong bisubstrate-biproduct reaction mechanism and displays inefficient kinetic behavior (kcat/KM = 1.81 × 10-4 ± 2.81 × 10-5 M-1 s-1), which is typical of exopolysaccharide-modifying enzymes in bacteria. Thus, the results presented, especially with respect to donor binding (as reflected by KM), have importantly broadened our understanding of the substrate profile and catalytic mechanism of this class of enzymes, which may aid in the development of inhibitors targeting BcsG or other characterized members of the pEtN transferase family, including the intrinsic and mobile colistin resistance factors.

Nickel-mediated Yamamoto coupling provides a concise and efficient synthesis of triphenylene derivatives, including electron-deficient discotic mesogens.

Bacterial biofilms are cellular communities that produce an adherent matrix. Exopolysaccharides are key structural components of this matrix and are required for the assembly and architecture of biofilms produced by a wide variety of microorganisms. The human bacterial pathogens Escherichia coli and Salmonella enterica produce a biofilm matrix composed primarily of the exopolysaccharide phosphoethanolamine (pEtN) cellulose. Once thought to be composed of only underivatized cellulose, the pEtN modification present in these matrices has been implicated in the overall architecture and integrity of the biofilm. However, an understanding of the mechanism underlying pEtN derivatization of the cellulose exopolysaccharide remains elusive. The bacterial cellulose synthase subunit G (BcsG) is a predicted inner membrane–localized metalloenzyme that has been proposed to catalyze the transfer of the pEtN group from membrane phospholipids to cellulose. Here we present evidence that the C-terminal domain of BcsG from E. coli (EcBcsGΔN) functions as a phosphoethanolamine transferase in vitro with substrate preference for cellulosic materials. Structural characterization of EcBcsGΔN revealed that it belongs to the alkaline phosphatase superfamily, contains a Zn2+ ion at its active center, and is structurally similar to characterized enzymes that confer colistin resistance in Gram-negative bacteria. Informed by our structural studies, we present a functional complementation experiment in E. coli AR3110, indicating that the activity of the BcsG C-terminal domain is essential for integrity of the pellicular biofilm. Furthermore, our results established a similar but distinct active-site architecture and catalytic mechanism shared between BcsG and the colistin resistance enzymes.

Biofilms are communities of self-enmeshed bacteria in a matrix of exopolysaccharides. The widely distributed human pathogen and commensal

The synthesis of the asymmetric ligand 3-phenyl-1-(pyridin-2-yl)-1H-pyrazol-5-amine (L1) and its single-crystal X-ray structure are reported. L1 displays crystallographic symmetry (orthorhombic, Pccn) higher than its molecular symmetry (point group C1) and also displays supercooling, with a difference in the melting and solidification points of over 100 °C. Upon complexation with ZnCl2, L1 engages in both primary cation and secondary anion coordination via hydrogen bonding, and the complex exhibits a room-to-low-temperature single crystal-to-crystal phase transition. The ZnCl2 complex becomes a birefringent fluid mixed with crystalline domains at high temperatures, as detected by polarized optical microscopy. Examination of the photoluminescence properties showed that the emission intensity increased and a pronounced bathochromic shift was observed in the emission maximum upon going from solution to the solid state, for both the ligand and complex, consistent with aggregation-induced emission behavior.

Understanding and control of weak intermolecular interactions, including π-interactions, is an element toward the strategic design of supramolecular materials. In this work, we describe an approach...

We report the synthesis and properties of a series of novel triphenylenedicarboxyimides and thioimides (4-6) to probe the effect of thionation on the formation of columnar mesophases. These materials display broad columnar mesophases and high clearing points and self-associate in solution to form dimers. Overall, thionation improved the self-assembly in solution and led to a stabilization of the columnar mesophase. Furthermore, increasing the thionation of these materials led to a lowering of the lowest unoccupied molecular orbital (LUMO) energy level and a narrowing of the highest occupied molecular orbital-LUMO gap.

We report the synthesis and mesophase characterization of a series of novel hexaalkoxydibenzanthracenes to probe the effect of side-chain length variation and substituents on the mesophase temperature range. A series of hexaalkoxydibenz[a,c]anthracenes (2a–2i) with varying chain lengths were prepared by Suzuki coupling of the appropriate boronate ester with the corresponding dialkoxydibromonaphthalenes, followed by oxidative cyclization. Compounds 2a–2i were also brominated in the 10 and 13 positions to yield the corresponding dibromo series, 4a–4i. While none of the compounds, 2a–2i, exhibited columnar mesophases, all of the compounds in series 4a–4i did exhibit columnar phases over broad temperature ranges. To further investigate the effect of substituents on the mesomorphic properties of hexaalkoxydibenzanthracenes, we also prepared iodo-substituted 8, nitro-substituted 9, and amino-substituted 10. A comparison of the mesophase temperature range with previously reported compounds 3–7 shows that electron-withdrawing groups promote the formation of stable mesophases. However, our results also suggest that the substituents affect mesophase stability by participating in intermolecular contacts within the columnar stacks of the mesophase.

Crystals of a tetraoxapentacene derivative bearing two diaminotriazine groups exhibit hydrogen-bonded sheets formed by the characteristic hydrogen bonding patterns of the diaminotriazines. By virtue of the large tetraoxapentacene moieties that are oriented perpendicular to the diaminotriazines, these sheets are unable to pack closely, leading to the formation of open network structures with a considerable volume accessible to guest molecules.

The synthesis of the asymmetric ligand 3-phenyl-1-(pyridin-2-yl)-1

The synthesis and single crystal structures of 3-phenyl-1-(pyridin-2-yl)-1H-pyrazol-5-amine (L1) and its complex with ZnCl2 are reported. L1 exhibits supercooling, with a difference in melting and solidification points of over 100 oC. The complex [L1ZnCl2] has a room-to-low temperature single crystal-to-crystal phase transition in the solid state, while a birefringent fluid phase mixed with crystalline domains is observed at high temperatures. Significant fluorescence enhancement is observed upon formation of the ZnCl2 complex.

A synthetic approach for preparing a variety of heterocyclic tetrahydropentacene derivatives via nucleophilic aromatic substitution reactions of bidentate nucleophiles and tetrafluoroterephthalonitrile was developed. X-ray crystallography of several products revealed that the compounds containing oxygen and nitrogen heteroatoms are highly planar and engage in π-stacking, while the compounds containing sulfur are bent and do not stack as effectively. The compounds were also highly emissive, and the heteroatom had a significant impact on the emission and electrochemical properties.

Bacterial biofilms are cellular communities that produce an adherent matrix. Exopolysaccharides are key structural components of this matrix and are required for the assembly and architecture of biofilms produced by a wide variety of microorganisms. The human bacterial pathogens Escherichia coli and Salmonella enterica produce a biofilm matrix composed primarily of the exopolysaccharide phosphoethanolamine (pEtN) cellulose. Once thought to be composed of only underivatized cellulose, the pEtN modification present in these matrices has been implicated in the overall architecture and integrity of the biofilm. However, an understanding of the mechanism underlying pEtN derivatization of the cellulose exopolysaccharide remains elusive. The bacterial cellulose synthase subunit G (BcsG) is a predicted inner membrane–localized metalloenzyme that has been proposed to catalyze the transfer of the pEtN group from membrane phospholipids to cellulose. Here we present evidence that the C-terminal domain of BcsG from E. coli (EcBcsG(ΔN)) functions as a phosphoethanolamine transferase in vitro with substrate preference for cellulosic materials. Structural characterization of EcBcsG(ΔN) revealed that it belongs to the alkaline phosphatase superfamily, contains a Zn(2+) ion at its active center, and is structurally similar to characterized enzymes that confer colistin resistance in Gram-negative bacteria. Informed by our structural studies, we present a functional complementation experiment in E. coli AR3110, indicating that the activity of the BcsG C-terminal domain is essential for integrity of the pellicular biofilm. Furthermore, our results established a similar but distinct active-site architecture and catalytic mechanism shared between BcsG and the colistin resistance enzymes.

We report the synthesis and mesophase characterization of a series of novel di- and tetra-aryl acenequinones. Diphenyl-acenequinones 1 and 2 exhibit monotropic mesophases while tetra-aryl acenequinones 4 and 5 exhibit stable columnar hexagonal mesophases. Compound 4 exhibits a more stable columnar mesophase than 5, consistent with a packing motif where molecules are stacked in perpendicular arrangement.

We report the synthesis and properties of a series of novel dibenzanthracenedicarboxythioimides and an investigation of the effects of thionation on self-assembly in these systems. These compounds all display columnar mesophases over broad temperature ranges and self-associate to form dimers in solution. Overall, thionation slightly improves self-assembly in these systems. Furthermore, increasing the thionation of these materials leads to a lowering of the LUMO energy and a narrowing of the HOMO–LUMO band gap.

A series of new tetrakis(dialkoxyphenyl) dicyanotetraoxapentacene derivatives (1 a-c) were prepared by reaction of the appropriate terphenyl diols with tetrafluoroterephthalonitrile in good yields. Compounds 1 b and 1 c, which bear hexyloxy and decyloxy side chains, exhibited columnar hexagonal mesophases, as shown by polarized optical microscopy, variable-temperature powder X-ray diffraction, and differential scanning calorimetry. Single-crystal X-ray diffraction of methoxy-substituted 1 a revealed that the dicyanotetraoxapentacene core is highly planar, consistent with the notion that these molecules are able to stack in columnar mesophases. A detailed photophysical characterization showed that these compounds exhibit aggregation-induced emission in solution, emission in nonpolar solvents, weak emission in polar solvents, and strong emission in the solid state both as powder and in thin films. These observations are consistent with a weakly emissive charge-transfer state in polar solvents and a more highly emissive locally excited state in nonpolar solvents.

We report the synthesis of a series of 2,3,5,6-tetraalkoxydibenz[a,c]anthracenes bearing substituents (H, OCH3, or CN) in the 11- and 12-positions and an investigation of their liquid-crystalline properties. The synthesis involved Suzuki coupling of the appropriate dibromonaphthalene and boronate ester, followed by an oxidative cyclization. Compounds 4 and 5, bearing OCH3 and H, respectively, do not exhibit any liquid-crystalline properties. In contrast, compounds 6a–c, bearing cyano groups, assemble into columnar mesophases, suggesting that electron-withdrawing groups are important for promoting columnar mesophase assembly. Analysis of the XRD revealed that compound 6b exhibits a columnar hexagonal phase, whereas compounds 6a and 6c exhibit columnar rectangular phases. The XRD data of 6a and 6b also show reflections that are consistent with antiparallel dimers within the columnar stacks, and intercolumnar spacings suggest that molecules are tilted within the columns.

Nine arylboronic acids, seven arylboronic catechol cyclic esters, and two trimeric arylboronic anhydrides (boroxines) are investigated using 11B solid-state NMR spectroscopy at three different magnetic field strengths (9.4, 11.7, and 21.1 T). Through the analysis of spectra of static and magic-angle spinning samples, the 11B electric field gradient and chemical shift tensors are determined. The effects of relaxation anisotropy and nutation field strength on the 11B NMR line shapes are investigated. Infrared spectroscopy was also used to help identify peaks in the NMR spectra as being due to the anhydride form in some of the arylboronic acid samples. Seven new X-ray crystallographic structures are reported. Calculations of the 11B NMR parameters are performed using cluster model and periodic gauge-including projector-augmented wave (GIPAW) density functional theory (DFT) approaches, and the results are compared with the experimental values. Carbon-13 solid-state NMR experiments and spectral simulations are applied to determine the chemical shifts of the ipso carbons of the samples. One bond indirect 13C-11B spin-spin (J) coupling constants are also measured experimentally and compared with calculated values. The 11B/10B isotope effect on the 13C chemical shift of the ipso carbons of arylboronic acids and their catechol esters, as well as residual dipolar coupling, is discussed. Overall, this combined X-ray, NMR, IR, and computational study provides valuable new insights into the relationship between NMR parameters and the structure of boronic acids and esters. Copyright © 2012 John Wiley & Sons, Ltd.

Effective charge transport in organic semiconductors requires orbital overlap between neighboring molecules and, therefore, is strongly dependent on solid state packing. Acenes such as pentacene, which have been widely studied as organic semiconductors, exhibit solid state packing motifs that are dominated by C–H···π interactions and show very little π-stacking. Recently, N-heteroacenes have emerged as potential alternatives to acenes as semiconducting materials. These compounds have altered frontier molecular orbital energies, show improved stability as compared to their hydrocarbon analogues, and are readily synthesized. However, the solid state structural features have not been systematically examined. In this study, the crystal structures of anthracene, tetracene, and pentacene are compared to N-substituted analogues using Hirshfeld surface analysis. While the acenes exhibit herringbone packing that is dominated by C–H···π interactions, the N-heteroacenes exhibit distinctly different packing motifs fe...

A robust and reasonably simple experiment is described that introduces students to the visualization of nanoscale properties and is intended for a first-year laboratory. Silver nanoprisms (NPs) that display different colors due to variation of their plasmonic absorption with respect to size are prepared. Control over the size of the silver nanoprisms is achieved using a novel approach, where bromide is added to the reaction as a size-determining agent, and silver ions are reduced by borohydride in the presence of citrate and peroxide as stabilizing and shape-directing agents, respectively. In a typical experiment, four dispersions of silver nanoprisms with different sizes are produced that are colored from blue (largest) to yellow (smallest). The colors attainable in between are violet, purple, red, and orange. The synthesis of these colored silver NPs is described for the first time as an undergraduate experiment. Once synthesized, the nanoprisms are characterized using UV−vis spectroscopy, and a Beer’s ...

Hexaphenylbenzene and related derivatives of benzene with multiple contiguous phenyl substituents have well-defined nonplanar topologies. Their structures limit conjugation and disfavor intermolecular π−π and C−H···π interactions. Such compounds therefore show higher HOMO−LUMO gaps, lower degrees of self-association, less efficient packing, and higher solubilities than planar analogues. These characteristic properties underlie the growing utility of nonplanar phenyl-substituted benzenes in science and technology. Surprisingly, no systematic structural analysis of compounds of this type has been reported. We have now examined structural features in crystals of hexaphenylbenzene, 1,2,4,5-tetraphenylbenzene, 1,4-dimethyl-2,3,5,6-tetraphenylbenzene, pentaphenylbenzene, 1-methyl-2,3,4,5,6-pentaphenylbenzene, and an octaphenyl-p-quinquephenyl. These compounds tend to crystallize in sheets held together by van der Waals contacts and small numbers of C−H···π interactions. Although the nonplanar topologies of thes...

Background: A genomic deletion of exon 3 (d3-GHR) of the growth hormone (GH) receptor (GHR) has been linked to the effectiveness of GH therapy in children with GH deficiency. Carriers of the d3-GHR genotype had higher GH-induced growth rates than children homozygous for the full-length (fl)-GHR. The aim of this study was to test whether the relationship between GH and insulin-like growth factor-1 (IGF-1) concentrations is influenced by the GHR genotype in patients with acromegaly. Methods: Study participants were 44 adult patients with established diagnosis of acromegaly. The genotype of the GHR was determined in leukocyte DNA from peripheral blood. Clinical and biochemical findings at the time of diagnosis of acromegaly were obtained from the medical records of the patients. Results: fl-GHR homozygosity was found in 22 (50%) of patients, and 22 (50%) of patients had at least 1 d3 allele (d3-GHR). Demographic and clinical characteristics (age, height, weight, estimated duration of disease, and mean tumor size) of the 2 groups were comparable. Median (range) serum IGF-1 concentrations at the time of diagnosis were 670 (447–1443) μg/L in the fl-GHR group and 840 (342–1494) μg/L in the d3-GHR group (P = not significant). Basal GH concentrations were higher in the fl-GHR group [29.7 (3.8–159) μg/L] than in the d3-GHR group [8.4 (2.6–74 μg/L), P = 0.002], and so were mean (30.4 vs 6.1 μg/L, P = 0.005) and nadir (20.5 vs 5.1 μg/L, P = 0.003) GH concentrations during an oral glucose tolerance test. Conclusions: The GHR fl/d3 genotype modulates the relationship between GH and IGF-1 concentrations in patients presenting with acromegaly.

Like other derivatives of hexaphenylbenzene, hexakis(4-nitrophenyl)benzene (1) crystallizes under a variety of conditions as layered structures in which significant quantities of guests are included in spaces between the layers or within them. In structures of nitroarene 1, multiple intermolecular N⋯O interactions of NO2 groups help to hold the layers together and determine how the molecular constituents are positioned. The behavior of nitroarene 1 confirms that N⋯O interactions can allow crystal engineers to position molecules with a useful degree of predictability, particularly when stronger interactions such as hydrogen bonds are absent, and when competition with other weak interactions is limited.

To evaluate the efficacy of two different Swedish screening procedures for early detection of congenital cataracts in comparison with no screening.Children born between January 1992 and December 1998 in Swedish regions with an established eye-screening routine procedure, diagnosed with congenital cataract, and operated on before 1 y of age, were included in a retrospective study. Age at referral and age at time of the operation were compared between regions using different screening procedures: screening in the maternity wards (Region 1), at the well-baby clinics (Region 2) and one region without any screening (Region 3).Seventy-two children were included in the study. Concerning early diagnosis and surgery, Region 1 differed significantly from Regions 2 and 3, which were more similar and were combined for further analysis. The difference in detected cases was greatest at 21 d of age (55% vs 18%; p0.001), but persisted even at 100 d of age (78% vs 64%; p0.02). Region 1 screening resulted in more and earlier cases detected than the other two regions (22 vs 15 per 100,000 births). In 72% of all cases, surgery was performed in response to referrals from either the maternity wards (36%), or the well-baby clinics (36%). However, half of the cases from the well-baby clinics were detected too late, i.e. at100 d.Eye screening in the maternity ward is preferable to well-baby clinic screening and to no screening at all, since it leads to early detection. Screening should also be performed routinely at well-baby clinics within the period when successful treatment is possible.

Suzuki coupling of dibromonaphthalenes and boronate esters followed by oxidative cyclization leads to dibenzanthracene derivatives.

Patients with chronic abdominal complaints are a diagnostic challenge for general practitioners (GP). Lactose intolerance (LI) often remains undiagnosed in these patients. Genetic testing for the homozygous -13910CC variant of the MCM-6 gene (LI+) combined with a lactose-restricted diet (LRD) seems to be an acceptable approach. The primary aim of the study was to determine the effect of a LRD in patients with chronic abdominal complaints without a definite diagnosis, with or without the homozygous -13910CC variant. The secondary aim was to determine in family practices the prevalence of undiagnosed LI in these patients.In 25 practices around Düsseldorf (Germany) all patients presenting with chronic abdominal complaints for at least 12 months without definite diagnosis were identified by their GPs. Patients participating underwent a MCM-6 gene test and all, including those not genetically predisposed, were asked to keep a LRD for eight weeks. Symptoms were evaluated three times over two months using a standardized gastrointestinal Questionnaire (GIQLI, max. score 144).210 patients were included. The gene test revealed 29.5% genetically positive for the homozygous T-13910-C mutation (LI+). All patients showed a significant increase in GIQLI scores (improvement) during the observation period, i.e. after four and eight weeks on the diet (p = 0.001, two-way repeated measures ANOVA). There was no significant difference between both groups (LI+/LI-) at any point of symptom measurement.A lactose-restricted diet showed an unspecific positive effect for patients with chronic abdominal pain without a defined diagnosis. For the LI-group, this could be explained by an unspecific effect of a diet in general, e.g., getting special attention. This can be important for a group of patients probably having psychosomatic complaints focussed on the abdomen.

Background: Inflammatory bowel disease-unclassified (IBD-U) is diagnosed in ∼10% of pediatric and adolescent onset IBD patients. The EUROKIDS registry (2004) initiated by the Porto IBD working group of ESPGHAN prospectively monitors diagnostic workup of newly diagnosed pediatric and adolescent onset IBD patients. We aimed to describe diagnostic workup, phenotype, and change of diagnosis over time in pediatric IBD-U patients. Methods: Data were collected on children from 52 centers across 20 European countries and Israel, diagnosed with IBD from May 2005 through November 2013. Full endoscopy plus small bowel radiology was considered complete diagnostic workup. Participating centers reporting IBD-U patients were queried in 2014 for follow-up data. Results: IBD-U was the provisional first diagnosis in 265 of 3461 children (7.7%) (91/158 [58%] with pancolitis; 140 [53%] male), diagnosed more frequently under the age of 10 (median age 12.3 years, 89 [34%] under 10 years). Half (48%) had undergone complete diagnostic workup. Lack of small bowel radiology was the prevailing reason for incomplete workup. As a result of reinvestigations (endoscopy in 54%, radiology in 38%) during a median follow-up of 5.7 years (interquartile range, 2.5-7.8), a change in diagnosis from IBD-U to Crohn's disease (12%) or ulcerative colitis (20%) was reported. Conclusions: Only half of patients reported as IBD-U in EUROKIDS had undergone complete diagnostic workup. Follow-up with reinvestigations resulted in a reduction of IBD-U rate to 5.6%. A diagnosis of IBD-U becomes less likely in case of complete diagnostic workup. Implementation of clear diagnostic criteria will further reduce the rate of IBD-U in the future. © 2015 Crohn's & Colitis Foundation of America, Inc.

OBJECTIVES: Chlamydia has been associated with autoimmune diseases, but a link between chlamydial infection and the aetiopathogenesis of inflammatory bowel disease (IBD) remains controversial. In this study we assessed the relationship between chlamydial infection and IBD, as evidenced by serological measurement and DNA analysis of mucosal biopsy specimens. PATIENTS AND METHODS: The sera of 78 patients with Crohn's disease (CD), 24 patients with ulcerative colitis (UC), 73 healthy family members, and 20 healthy controls were tested for anti-C. pneumoniae IgG titres. A subgroup consisting of 13 UC and 39 CD patients was screened for the presence of chlamydial DNA on 42 inflamed versus 30 non-inflamed biopsy specimens and for mutations of their NOD2/CARD15 gene. RESULTS: Anti-C. pneumoniae IgG antibodies were found in the sera of 32 (41%) patients with CD, 11 (46%) patients with UC, 35 (48%) of unaffected family members, and nine (45%) unrelated healthy controls. Thirty-five percent of the control, 18% CD and 24% UC biopsy specimens contained C. pneumoniae DNA. In CD, however, C. pneumoniae DNA was significantly more frequently found in inflamed (27%) versus non-inflamed (8%) biopsy specimens (P < 0.05, Fisher's exact test). The frequencies of NOD2/CARD15 mutations were 33% for CD patients with C. pneumoniae DNA compared to 47% for CD patients without C. pneumoniae DNA. CONCLUSION: We found no marked differences in respect to anti-C. pneumoniae serum IgG or C. pneumoniae DNA between healthy controls and patients with IBD. However, in CD patients, inflamed tissue specimens contained significantly more likely C. pneumoniae DNA compared with biopsies from unaffected areas. Thus C. pneumoniae is unlikely to be of pathogenic importance in IBD while it may still influence local clinical manifestations.

Hexakis(4-cyanophenyl)benzene (1) was crystallized from various solvents, and the structures were determined by X-ray crystallography. In all cases studied, inclusion compounds were obtained, and crystallization yielded networks held together primarily by C−H···N interactions. However, the resulting structures were diverse and depended strongly on the solvent used for crystallization. In certain cases, remarkably large fractions of the volumes of the crystals (up to 58%) are accessible to guests. The diversity of the structures obtained underscores the limitations of using C−H···N interactions in crystal engineering.

The study of compounds containing boron continues to have an important impact on virtually every area of chemistry. One of the few areas in which compounds of boron have been neglected is crystal engineering, which seeks to develop and exploit an understanding of how the structure and properties of crystals are related to the individual atomic or molecular components. Although detailed predictions of crystal structures are not yet reliable, crystal engineers have developed a sound qualitative strategy for anticipating and controlling structural preferences. This strategy is based on the design of special molecules, called tectons, which feature carefully selected cores and multiple peripheral functional groups that can direct association and thereby place neighboring molecules in predetermined positions. Recent work has demonstrated that molecular crystals with unique properties can be constructed logically from tectons with boron in their cores or sticky sites of association. In particular, the -B(OH)2 group of boronic acids engages in reliable patterns of hydrogen bonding, and its use as a sticky site in tectons has emerged as an effective tool for controlling association predictably. In addition, replacement of tetraphenylsilyl or tetraphenylmethyl cores in tectons by tetraphenylborate leaves the overall molecular geometry little changed, but it has the profound effect of introducing charge. Tectons derived from tetraphenylborate can be used rationally to construct porous charged molecular networks that resemble zeolites and undergo selective ion exchange. In such ways, boron offers chemists exciting new ways to engineer molecular crystals with predetermined structures and properties.

A possible influence of Chlamydia pneumoniae seropositivity on the clinical course of peripheral arterial occlusive disease (PAOD) has not been investigated previously. Though roxithromycin therapy was found to inhibit progression of PAOD, the nature of this effect (antibiotic or anti-inflammatory) has remained elusive. The course of PAOD was prospectively assessed in elderly men during 4 years, comparing 51 C. pneumoniae seropositive (IgG ≥ 1:128) with 46 seronegative patients (IgG < 1:64 and IgA < 1:32). Twenty of the seropositive patients were treated with roxithromycin (400 mg daily) for 4 weeks. Limitation of the walking distance to 200 m or less was observed in 55% of the seropositive untreated patients as compared to 30% of both, seronegative and macrolide-treated patients. The number of invasive revascularizations per patient was 1.7 in the seropositive untreated group as compared to 0.5 in the seronegative and the macrolide-treated group. Considering possible confounding variables, such as classical vascular risk factors, ordinal regression analyses showed a significant association of C. pneumoniae seropositivity with limitation of the walking distance (p = 0.027) and need for invasive revascularization (p = 0.037). The effect of macrolide treatment on these outcome measures was marked (p < 0.001 and p = 0.040, respectively) during 2.7 years but decreased in the second part of the observation period. This study provides good evidence that C. pneumoniae are involved in the progression of PAOD and that antibiotic treatment directed against C. pneumoniae is effective in inhibiting this process.

Useful modifications to a previously reported synthesis of imidazolium room-temperature ionic liquids (RTILs) for the undergraduate organic chemistry teaching laboratory are reported.

OBJECTIVE Sustained psychological stress may result in a state operationalized as "vital exhaustion." Exhaustion predicted coronary artery disease (CAD) events whereby increased inflammatory activity might mediate this link. Moreover, there is an emerging importance of gene-environmental interactions in CAD. We investigated the effect of exhaustion severity on plasma levels of C-reactive protein (CRP) and whether exhaustion might regulate CRP levels via the -308G/A polymorphism of the tumor necrosis factor (TNF)-alpha gene. METHODS We assessed exhaustion in 275 industrial employees (mean age +/- SD, 41 +/- 9 years, 88% men) using the Maastricht Questionnaire. Subjects were stratified as per exhaustion severity: none (N = 80), moderate (N = 128), and severe (N = 67). The TNF-alpha polymorphism was determined by real-time polymerase chain reaction, and plasma CRP levels were measured by a high-sensitivity immunoassay. RESULTS There was a significant interaction between exhaustion and the TNF-alpha polymorphism, explaining 4.5% in the variance of plasma CRP values (F(5,271) = 2.47, p =.033); the result held after controlling for classic cardiovascular risk factors. Adjusted mean CRP levels across exhaustion strata in GA (N = 70) and AA (N = 3) carriers combined were 0.91 mg/l (none), 1.78 mg/l (moderate), and 2.61 mg/l (severe) as compared with 1.24 mg/l, 1.61 mg/l, and 1.36 mg/l for the GG wild-type (N = 202). CONCLUSION The findings suggest that the A allele of the TNF-alpha -308 G/A polymorphism may mediate inflammation with exhaustion in a dose-response relationship, while with the GG wild-type exhaustion severity seems unrelated to CRP levels. The finding provides a rationale for gene-environmental interactions by which psychosocial factors may promote atherosclerosis and CAD.

Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or have undergone total hip replacement. In this report, stable folding variants of the natural occurring osteoinductive BMPs were shown to act as inhibitors for heterotopic ossification. The most effective BMP folding variant construct performed even better than the natural occurring BMP antagonist Noggin because it also inhibited calcium deposition of pre-osteoblastic cells. INTRODUCTION: Signal transduction through receptor and ligand binding depends on the proper folding of all partners, especially when it involves the formation of a heterotetramer. In the case, the receptor binding of the ligand can be uncoupled from signal transduction, and folding variants of a ligand can be developed into antagonists of the natural bioactivity of the ligand. Here we present a deletion mutant of a bone morphogenetic protein (BMP) folding variant capable of inhibiting the bone-inducing action of natural occurring BMPs. MATERIALS AND METHODS: Deletion mutants and site-directed mutants of BMP folding variants were generated and tested for their ability to reduce alkaline phosphatase activity and mineralization in a pre-osteoblastic cell line. In vivo activity of the optimized folding variant was determined in a heterotopic ossification model in rodents and in two Xenopus laevis model systems. Biosensor interaction analysis was used to determine the affinity of the optimized BMP folding variant to the extracellular domain of BMP receptors. RESULTS: In vitro and in vivo tests in rodents revealed that the structural elements of the wrist epitope combined with finger 2 and a positive charge proximal to the tip of this finger are sufficient to induce osteoinhibition with deletion mutants and folding variants of mature BMP-4. The inhibitor designed to suppress heterotopic ossification showed BMP antagonist activity in embryos and animal caps of X. laevis. Binding studies of the inhibitor to ectodomains of type I and type II BMP receptors revealed a concentration-dependent binding, especially to the high-affinity BMP receptor. CONCLUSIONS: Deletion mutants of BMP folding variants are a new form of BMP antagonists and act through competition with osteoinductive BMP for BMP receptor binding. The excellent in vivo performance of the optimized folding variant is because of its ability to block signaling of endogenous BMPs deposited in the extracellular matrix even more effectively than the natural occurring BMP antagonist Noggin.

Bone morphogenetic proteins (BMPs) are multifunctional cytokines that were originally identified as molecules that induce bone and cartilage formation in vivo. In order to increase the efficacy of this potent protein for application in medicine, a carrier system is needed to retain the BMP at the preferred site. Here we present and characterize a slow-release carrier system for pure human recombinant (rh)BMP. The large porous microspheres, called 'foamspheres', are biodegradable, because they consist of poly(lactide-co-glycolide) acids and release loaded rhBMP slowly and continuously. In vivo studies in rodents revealed that rhBMP-loaded foamspheres increased the thickness of the calvarial bone of rats by 222%. When the same amount of rhBMP was applied via a gelatine-based hydrogel, the increase in bone height was only 66%. Thus, the carrier system for rhBMP is an important factor for the efficacy of BMPs.

The synthesis and characterization of a novel series of dibenz[a,c]anthracenedicarboximides is reported. Incorporating electron-withdrawing imides bearing flexible alkyl chains allowed for the production of materials that self-assemble into hexagonal columnar mesophases featuring broad temperature ranges. Furthermore, longer N-alkyl chains or branched N-alkyl chains broaden the mesophase temperature range by lowering the melting transition without greatly influencing the clearing point.

BACKGROUND: INSTAND e.V. has provided Molecular Genetics Multi-Analyte EQA schemes since 2006. METHODS: EQA participation and performance were assessed from 2006 - 2012. RESULTS: From 2006 to 2012, the number of analytes in the Multi-Analyte EQA schemes rose from 17 to 53. Total number of results returned rose from 168 in January 2006 to 824 in August 2012. The overall error rate was 1.40 +/- 0.84% (mean +/- SD, N = 24 EQA dates). From 2006 to 2012, no analyte was reported 100% correctly. Individual participant performance was analysed for one common analyte, Lactase (LCT) T-13910C. From 2006 to 2012, 114 laboratories participated in this EQA. Of these, 10 laboratories (8.8%) reported at least one wrong result during the whole observation period. All laboratories reported correct results after their failure incident. CONCLUSIONS: In spite of the low overall error rate, EQA will continue to be important for Molecular Genetics.

Background Patients with chronic abdominal complaints are a diagnostic challenge for general practitioners (GP). Lactose intolerance (LI) often remains undiagnosed in these patients. Genetic testing for the homozygous -13910CC variant of the MCM-6 gene (LI+) combined with a lactose-restricted diet (LRD) seems to be an acceptable approach. The primary aim of the study was to determine the effect of a LRD in patients with chronic abdominal complaints without a definite diagnosis, with or without the homozygous -13910CC variant. The secondary aim was to determine in family practices the prevalence of undiagnosed LI in these patients. Methods In 25 practices around Dusseldorf (Germany) all patients presenting with chronic abdominal complaints for at least 12 months without definite diagnosis were identified by their GPs. Patients participating underwent a MCM-6 gene test and all, including those not genetically predisposed, were asked to keep a LRD for eight weeks. Symptoms were evaluated three times over two months using a standardized gastrointestinal Questionnaire (GIQLI, max. score 144). Results 210 patients were included. The gene test revealed 29.5% genetically positive for the homozygous T-13910-C mutation (LI+). All patients showed a significant increase in GIQLI scores (improvement) during the observation period, i.e. after four and eight weeks on the diet (p = 0.001, two-way repeated measures ANOVA). There was no significant difference between both groups (LI+/LI-) at any point of symptom measurement. Conclusions A lactose-restricted diet showed an unspecific positive effect for patients with chronic abdominal pain without a defined diagnosis. For the LI-group, this could be explained by an unspecific effect of a diet in general, e.g., getting special attention. This can be important for a group of patients probably having psychosomatic complaints focussed on the abdomen.

Background . Cardiopulmonary bypass (CPB) is associated with tissue damage mediated by adhesion molecules and cytokines. Prebypass steroid administration may modulate the inflammatory response, resulting in improved postoperative recovery. Methods . Fifty patients undergoing elective coronary operations under normothermic CPB were randomized into two groups: group A (n = 24) received intravenous methylprednisolone (10 mg/kg) 4 hours preoperatively, and group B (n = 26) served as controls. Cytokines (tumor necrosis factor-α [TNF-α], interleukin-2R [IL-2R], IL-6, IL-8), soluble adhesion molecules (sE-selectin, sICAM-1), C-reactive protein, and leukocytes were measured before steroid application, then 24 and 48 hours, and 6 days postoperatively. Adhesion molecules were measured by enzyme-linked immunosorbent assay, cytokines by chemiluminescent immunoassay. Postoperatively, hemodynamic measurements, inotropic agent requirements, blood loss, duration of mechanical ventilation, and intensive care unit stay were compared. Results . Aortic cross-clamp and CPB time was similar in both groups. Prednisolone administration reduced postoperative levels of IL-6 (611 versus 92.7 pg/mL; p = 0.003), TNF-α (24.4 versus 11.0 pg/L, p = 0.02), and E-selectin (327 versus 107 ng/mL, p = 0.02). Postoperative recovery did not differ between groups. Conclusions . Preoperative administration of methylprednisolone blunted the increase of IL-6, TNF-α, and E-selectin levels after CPB but had no measurable effect on postoperative recovery.

Objective: Cardiopulmonary bypass (CPB) surgery induces a transient rise in pro-inflammatory cytokines typically released by activated monocytes. The E4 variant of apolipoprotein E is a recognized risk factor for atherosclerosis. It has recently been shown that apolipoprotein E affects monocyte functions in vitro and leads to higher levels of median lipoprotein (a) in humans. The aim of the study is to investigate if the E4 genetic variant of apolipoprotein E affects cytokine release after CPB surgery. Methods: 22 patients were operated on with standard coronary artery bypass grafting. Concentrations of interleukin 8 (IL-8) and tumor necrosis factor (TNF-a) were measured by automated Immulite immunoassay at regular intervals within 48 h after surgery. Total apparent cytokine outputs were calculated as area under the curve. Results are expressed as mean ^ standard deviation and compared by unpaired t-test. Results: In the presented patient population 6 (27%) carried the E4 allele. Sixteen (63%) showed no E4 allele. Mean cross clamp time (CCT) was 56.2 ^ 13.5 min versus 55.7 ^ 12.1 min and CPB time was 91.8 ^ 17.5 versus 93.5 ^ 15.7 min. No statistical difference between E4-carriers and E4 non-carriers regarding CCT and CPB was observed. The total amount of IL-8 and TNF-a was higher in patients carrying the E4 genetic variant of apolipoprotein E in comparison to E4 non-carriers (P , 0:08, P , 0:039). Conclusion: The presence of the E4 allele is associated with increased release of IL-8 and TNF-a after CBP surgery. The preoperative determination of E4 in patients undergoing cardiac surgery may lead to additional perioperative measures for the treatment of an increased systemic inflammatory response. q 2001 Elsevier Science B.V. All rights reserved.

Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or undergone total hip replacement. Heterotopic ossification occurs when osteogenic precursor cells present at the ectopic site receive the necessary signal(s) to differentiate into osteoblasts. At the protein level, the key factors in differentiation of cells to the osteogenic lineage are BMPs. Stable BMP variants derived from the identical amino acid sequence but with different disulfide bridge configurations have been investigated and found to be capable of inhibiting ossification in vitro and in vivo in rodents. These findings provide a concept for the straightforward development of a novel class of BMP antagonists that could lead to new treatments for traumatically and genetically induced heterotopic ossification and also, possibly, for disorders in which other members of the TGF-beta superfamily are involved.

OBJECTIVE—The effects of glucose, arginine, and glucagon on β-cell function as well as α-cell response to arginine were studied in a family with mitochondrial diabetes. RESEARCH DESIGN AND METHODS—The function of α- and β-cells was assessed in all five siblings carrying the mitochondrial tRNA Leu(UUR) gene mutation at position 3243 and compared with six sex-, age-, and weight-matched control subjects. Insulin and C-peptide responses were evaluated by intravenous glucagon application, intravenous arginine stimulation test, and intravenous glucose tolerance test. Glucagon secretion was assessed during the arginine stimulation test. RESULTS—The glucose disappearance constant (Kg) value (mean ± SEM 0.61 ± 0.04 vs. 1.1 ± 0.04, P = 0.0002) as well as the acute insulin response to glucose (area under the curve [AUC] 0–10 min, 77.7 ± 50.7 vs. 1,352.3 ± 191.5 pmol/l, P = 0.0004) were decreased in all patients. Similarly, glucagon-stimulated C-peptide response was also impaired (728 ± 111.4 vs. 1,526.7 ± 157.7 pmol/l, P = 0.005), whereas the insulin response to arginine (AUC) was normal (1,346.9 ± 710.8 vs. 1,083.2 ± 132.5 pmol/l, P = 0.699). Acute glucagon response to arginine (AUC) was normal but tended to be higher in the patients than in the control subjects (181.7 ± 47.5 vs. 90.0 ± 21.1 pmol/l, P = 0.099). CONCLUSIONS—This study shows impaired insulin and C-peptide secretion in response to a glucose challenge and to glucagon stimulation in diabetic patients with mitochondrial tRNA Leu(UUR) gene mutation, although insulin and glucagon secretory responses to arginine were normal.

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

The solubility of two partially deuterated thioindigo dopants in a smectic liquid crystal host was evaluated by variable temperature 2H NMR spectroscopy and polarized microscopy. 2H NMR spectra showed that the dopant (±)-6,6'-bis(2-octyloxy)-5,5-dinitrothioindigo-d 6 forms a homogeneous solution with the smectic phases of the liquid crystal host (±)-4-(4-methylhexyloxy)phenyl 4-decyloxybenzoate (PhB) up to its saturation point of 3 mol %. These results are consistent with polarized microscopy observations of the dopant crystallizing out of solution upon reaching a concentration of 3 mol %. On the other hand, 2H NMR spectra of (±)-5,5'-dichloro-6,6'-bis(2-octyloxy)thioindigo-d 6 dissolved in PhB showed evidence of a partitioning of the solution between smectic and isotropic microdomains, which increases with increasing dopant concentration—from 1.2 to 9.1 mol %. To a large extent, this smectic/isotropic microphase separation could not be detected by polarized microscopy. These results suggest that 2H NMR s...