bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Single‐Crystal‐to‐Single‐Crystal Anion Exchange and Self‐Assembly of Luminescent d10 Metal (CdII, ZnII, and CuI) Complexes Containing C3‐Symmetrical Ligands
Authors: Tzeng Biing‐Chiau , Chiu Tse‐Hao , Chen Bo‐So , Lee Gene‐Hsiang 
Published: April 2008

AbstractLigands L1 and L2′ (L1=N,N′,N′′‐tris(4‐pyridyl)trimesic amide, L2′=N,N′,N′′‐tris(3‐pyridinyl)‐1,3,5‐benzenetricarboxamide) belonging to an interesting family of tripyridyltriamides with C3‐symmetry have been utilized to construct 3D porous or hydrogen‐bonded frameworks. Through a novel single‐crystal‐to‐single‐crystal anion‐exchange process, [Cd(L1)2(ClO4)2]n (1 c) can be obtained from [Cd(L1)2Cl2]n (1 b) in the presence of ClO4− anions. This anion‐exchange process is highly selective and only the substitution of Cl− by ClO4− or PF6− could be realized; Cl− was found not to be substituted by BPh4−. This demonstrates that the exchange process depends on the size of the anions in relation to the size of the cavities in the host material (ca. 7.5 Å). In addition, the anion‐exchange properties of 1 b have also been investigated by means of powder X‐ray diffraction (PXRD), elemental analysis (EA), and infrared absorption spectroscopy (IR). Structurally, [Zn(L1)(NO3)2]n (2) consists of a 2D coordination network with five‐coordinate ZnII ions. Surprisingly, different trigonal‐bipyramidal ZnII ions propagate to form distinct respective sheet structures, A and B, which are packed in an A‐B‐A‐B manner in the crystal lattice, and these are hydrogen‐bonded to give a 3D extended framework. The molecular structure of [CuI(L2′)]n (3) shows that the CuI ion adopts a distorted tetrahedral geometry, and 3 also forms a 2D coordination network. Significantly, this 2D coordination network is further assembled into a remarkable 3D homochiral framework through triple hydrogen bonding and π⋅⋅⋅π interactions. All of these 3D coordination polymers and/or hydrogen‐bonded frameworks are luminescent in the solid state, and their solid‐state luminescent properties have been investigated at room temperature and/or at 77 K.
New Mono‐ and Dimeric Members of the Secalonic Acid Family: Blennolides A–G Isolated from the Fungus Blennoria sp.
Authors: Zhang Wen , Krohn Karsten , Zia‐Ullah  , Flörke Ulrich , Pescitelli Gennaro , Di Bari Lorenzo , Antus Sándor , Kurtán Tibor , Rheinheimer Joachim , Draeger Siegfried , Schulz Barbara 
Published: April 2008

AbstractBlennolides A–G (2–8), seven unusual chromanones, were isolated together with secalonic acid B (1) from Blennoria sp., an endophytic fungus from Carpobrotus edulis. This is the first reported isolation of the blennolides 2 and 3 (hemisecalonic acids B and E), the existence of which as the monomeric units of the dimeric secalonic acids had long been postulated. A compound of the proposed structure 4 (β‐diversonolic ester) will need to be revised, as its reported data do not fit those of the established structure of blennolide C (4). Other monomers, the blennolides D–F (5–7) seem to be derived from blennolides A (2) and B (3) by rearrangement of the hydroaromatic ring. The heterodimer 8, composed of the monomeric blennolide A (2) and the rearranged 11‐dehydroxy derivative of blennolide E (6), extends the ergochrome family with an ergoxanthin type of skeleton. The structures of the new compounds were elucidated by detailed spectroscopic analysis and further confirmed by an X‐ray diffraction study of a single crystal of 2. The absolute configurations were determined by TDDFT calculations of CD spectra, including the solid‐state CD/TDDFT approach. Preliminary studies showed strong antifungal and antibacterial activities of these compounds against Microbotryum violaceum and Bacillus megaterium, respectively. They were also active against the alga Chlorella fusca and the bacterium Escherichia coli.
Similar Biological Activities of Two Isostructural Ruthenium and Osmium Complexes
Authors: Maksimoska Jasna , Williams Douglas S. , Atilla‐Gokcumen G. Ekin , Smalley Keiran S. M. , Carroll Patrick J. , Webster Richard D. , Filippakopoulos Panagis , Knapp Stefan , Herlyn Meenhard , Meggers Eric 
Published: April 2008

AbstractIn this study, we probe and verify the concept of designing unreactive bioactive metal complexes, in which the metal possesses a purely structural function, by investigating the consequences of replacing ruthenium in a bioactive half‐sandwich kinase inhibitor scaffold by its heavier congener osmium. The two isostructural complexes are compared with respect to their anticancer properties in 1205 Lu melanoma cells, activation of the Wnt signaling pathway, IC50 values against the protein kinases GSK‐3β and Pim‐1, and binding modes to the protein kinase Pim‐1 by protein crystallography. It was found that the two congeners display almost indistinguishable biological activities, which can be explained by their nearly identical three‐dimensional structures and their identical mode of action as protein kinase inhibitors. This is a unique example in which the replacement of a metal in an anticancer scaffold by its heavier homologue does not alter its biological activity.
Hydroxycruciforms: Amine‐Responsive Fluorophores
Authors: McGrier Psaras L. , Solntsev Kyril M. , Miao Shaobin , Tolbert Laren M. , Miranda Oscar R. , Rotello Vincent M. , Bunz Uwe H. F. 
Published: April 2008

AbstractThe synthesis of three hydroxy‐substituted cruciforms (XF, 1,4‐bis(4′‐hydroxystyryl)‐2,5‐bis(4′′‐methoxyphenylethynyl)benzene, 1,4‐bis(4′‐methoxystyryl)‐2,5‐bis(4′′‐hydroxyphenylethynyl)benzene, and 1,4‐bis(4′‐hydroxystyryl)‐2,5‐bis(4′′‐hydroxyphenylethynyl)benzene) starts with a Horner reaction followed by a Sonogashira coupling and subsequent deprotection. The three herein described XFs contain either two or four free phenolic hydroxyl groups. All three XFs were subjected to photometric UV/Vis titrations in a methanol/water mixture. The respective pKa values were obtained by data deconvolution. As the three XFs display a significant change in emission color upon photoinduced deprotonation, the XFs were taken up in different solvents and exposed to twelve amines. The amine‐dependent change in emissivity of the tetrahydroxy XF is sufficiently distinct in the eight solvents that all of the inspected amines are discerned by a linear discriminant analysis. The tetrahydroxy XF in different solvents forms a sensor array, the response of which is based on the excited‐state proton transfer (ESPT) to amines and mediated by the choice of the battery of solvents that are utilized.
Glycine receptor‐mediated synaptic transmission regulates the maturation of ganglion cell synaptic connectivity
Authors: Xu Hong‐Ping , Tian Ning 
Published: April 2008

AbstractIt is well documented that neuronal activity is required for the developmental segregation of retinal ganglion cell (RGC) synaptic connectivity with ON and OFF bipolar cells in mammalian retina. Our recent study showed that light deprivation preferentially blocked the developmental RGC dendritic redistribution from the center to sublamina a of the inner plexiform layer (IPL). To determine whether OFF signals in visual stimulation are required for OFF RGC dendritic development, the light‐evoked responses and dendritic stratification patterns of RGCs in Spastic mutant mice, in which the OFF signal transmission in the rod pathway is largely blocked due to a reduction of glycine receptor (GlyR) expression, were quantitatively studied at different ages and rearing conditions. The dendritic distribution in the IPL of these mice was indistinguishable from wildtype controls at the age of postnatal day (P)12. However, the adult Spastic mutants had altered RGC light‐evoked synaptic inputs from ON and OFF pathways, which could not be mimicked by pharmacologically blocking of glycinergic synaptic transmission on age‐matched wildtype animals. Spastic mutation also blocked the developmental redistribution of RGC dendrites from the center to sublamina a of the IPL, which mimicked the effects induced by light deprivation on wildtype animals. Moreover, light deprivation of the Spastic mutants had no additional impact on the RGC dendritic distribution and light response patterns. We interpret these results as that visual stimulation regulates the maturation of RGC synaptic activity and connectivity primarily through GlyR‐mediated synaptic transmission. J. Comp. Neurol. 509:53–71, 2008. © 2008 Wiley‐Liss, Inc.
The 4–1BB ligand and 4–1BB expressed on osteoclast precursors enhance RANKL‐induced osteoclastogenesis via bi‐directional signaling
Authors: Yang Jihyun , Park Ok Jin , Lee Yeon Ju , Jung Hong‐Moon , Woo Kyung Mi , Choi Youngnim 
Published: April 2008

AbstractThe 4–1BB is a costimulatory molecule similar to the receptor activator of NF‐κB ligand (RANKL), both of which are key factors for the differentiation of osteoclasts and are expressed mainly by activated T cells. The 4–1BB shares common signaling pathways with RANK, suggesting a potential role in osteoclastogenesis. In this study, the role of 4–1BB and 4–1BB ligand (4–1BBL) in osteoclastogenesis was investigated using 4–1BB–/– and 4–1BB+/+ mice. Osteoclast precursors normally express 4–1BB and 4–1BBL after exposure to RANKL, which was confirmed by semi‐quantitative RT‐PCR and flow cytometry. The 4–1BB–/– mice had a slightly increased bone mass accompanied by a reduced osteoclastogenic ability of 4–1BB–/– bone marrow‐derived macrophages (BMM) ex vivo. In addition, 4–1BB–/– BMM demonstrated hypophosphorylation of JNK and p38 and decreased induction of c‐Fos in response to RANKL stimulation. Retroviral transduction of wild‐type as well as partial‐length 4–1BB, which lacks TNF receptor‐associated factor 2‐binding sites for signaling, restored the osteoclastogenic ability of 4–1BB–/– BMM. Furthermore, both recombinant 4–1BB and 4–1BBL enhanced RANKL‐induced osteoclastogenesis by 4–1BB+/+ BMM and the induction of c‐Fos and NFATc1.Together, these results indicate that 4–1BBL and 4–1BB expressed on osteoclast precursors enhance RANKL‐induced osteoclastogenesis via bi–directional signaling, findings that may delineate the complex nature of the 4–1BBL and 4–1BB interaction.Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/37650_s.pdf
Suppression of viral replication with highly active antiretroviral therapy has no impact on the functional profile of HIV‐specific CD8+ T cells
Authors: López Mariola , Soriano Vincent , Rallón Norma , Cascajero Almudena , González‐Lahoz Juan , Benito José M. 
Published: April 2008

AbstractA better control of viral replication in long‐term non‐progressors has been associated with polyfunctional CD8+ T cell responses. However, low levels of HIV replication could be the cause rather than the consequence of enhanced immune responses in long‐term non‐progressors. The functional profile and the expansion ability of HIV‐Gag‐ and HIV‐Nef‐specific CD8 responses were analysed measuring the production of MIP‐1β, IL‐2, TNF‐α and expression of CD107, using polychromatic flow cytometry, in 36 HIV‐infected patients at baseline and after 12 months of highly active antiretroviral therapy (HAART) and complete viral suppression. Most patients presented detectable Gag and Nef responses both at baseline and after 1 year of HAART, with a significant decline after achieving viral suppression. At baseline, the majority of CD8+ response was due to cells producing only MIP‐1β or simultaneously MIP‐1β and CD107. The functional profile did not significantly change after achieving complete viral suppression with HAART. Therefore, control of HIV‐1 replication after 1 year of HAART had no significant impact on the quality of HIV‐1‐specific CD8 response, but the effects of treatment in long‐term, or of early HAART are not known. Thus, it is still uncertain whether multifunctional CD8 responses are the cause or consequence of low plasma viremia.
Development of a capillary electrophoresis‐mass spectrometry method using polymer capillaries for metabolomic analysis of yeast
Authors: Tanaka Yoshihide , Higashi Tetsuji , Rakwal Randeep , Wakida Shin‐ichi , Iwahashi Hitoshi 
Published: April 2008

AbstractMetabolomics is an emerging field in analytical biochemistry, and the development of such a method for comprehensive and quantitative analysis of organic acids, carbohydrates, and nucleotides is a necessity in the era of functional genomics. When a concentrated yeast extract was analyzed by CE‐MS using a successive multiple ionic‐polymer layer (SMIL)‐coated capillary, the adsorption of the contaminants on the capillary wall caused severe problems such as no elution, band‐broadening, and asymmetric peaks. Therefore, an analytical method for the analysis of anionic metabolites in yeast was developed by pressure‐assisted CE using an inert polymer capillary made from poly(ether etherketone) (PEEK) and PTFE. We preferred to use the PEEK over the PTFE capillary in CE‐MS due to the easy‐to‐use PEEK capillary and its high durability. The separation of anionic metabolites was successfully achieved with ammonium hydrogencarbonate/formate buffer (pH 6.0) as the electrolyte solution. The use of 2‐propanol washing after every electrophoresis run not only eliminated wall‐adsorption phenomena, but allowed for good repeatability to be obtained for migration times in the metabolomic analysis.
Application of capillary isotachophoresis‐based multidimensional separations coupled with electrospray ionization‐tandem mass spectrometry for characterization of mouse brain mitochondrial proteome
Authors: Fang Xueping , Wang Weijie , Yang Li , Chandrasekaran Krish , Kristian Tibor , Balgley Brian M. , Lee Cheng S. 
Published: April 2008

AbstractBy employing a capillary ITP (CITP)/CZE‐based proteomic technology, a total of 1795 distinct mouse Swiss‐Prot protein entries (or 1705 nonredundant proteins) are identified from synaptic mitochondria isolated from mouse brain. The ultrahigh resolving power of CITP/CZE is evidenced by the large number of distinct peptide identifications measured from each CITP fraction together with the low peptide fraction overlapping among identified peptides. The degree of peptide overlapping among CITP fractions is even lower than that achieved using combined CIEF/nano‐RP LC separations for the analysis of the same mitochondrial sample. When evaluating the protein sequence coverage by the number of distinct peptides mapping to each mitochondrial protein identification, CITP/CZE similarly achieves superior performance with 1041 proteins (58%) having 3 or more distinct peptides, 233 (13%) having 2 distinct peptides, and 521 (29%) having a single distinct peptide. The reproducibility of protein identifications is found to be around 86% by comparing proteins identified from repeated runs of the same mitochondrial sample. The analysis of the mouse mitochondrial proteome by two CITP/CZE runs results in the detection of 2095 distinct mouse Swiss‐Prot protein entries (or 1992 nonredundant proteins), corresponding to 59% coverage of the updated Maestro mitochondrial reference set. The collective analysis from combined CITP/CZE and CIEF‐based proteomic studies yields the identification of 2191 distinct mitochondrial protein entries (or 2082 nonredundant proteins), corresponding to 76% coverage of the MitoP2‐database reference set.
Analysis of intact erythropoietin and novel erythropoiesis‐stimulating protein by capillary electrophoresis‐electrospray‐ion trap mass spectrometry
Authors: Giménez Estela , Benavente Fernando , Barbosa José , Sanz‐Nebot Victoria 
Published: April 2008

AbstractRecombinant human erythropoietin (rHuEPO) and novel erythropoiesis‐stimulating protein (NESP) were analyzed by CE‐ESI‐MS using an IT as analyzer. The IT parameters were optimized by direct infusion of solutions of different intact proteins (myoglobin, transferrin, α1‐acid glycoprotein and fetuin) with different degrees of glycosylation (from 0 to 35% w/w). Two physically adsorbed capillary coatings from UltraTol™ Pre‐Coats (low normal (LN) and high reverse (HR)) were evaluated for the separation of rHuEPO and NESP glycoforms by CE‐ESI‐IT‐MS. The results obtained with the neutral LN coating suggest that an IT mass spectrometer enables identification of the main glycoforms of a complex glycoprotein such as rHuEPO. Although LN provided acceptable glycoform resolution for rHuEPO, the separation obtained for NESP was less significant due to the higher microheterogeneity of this glycoprotein. Reproducibility studies confirmed the lack of stability and bleeding of the LN coating, which caused problems with MS detection, such as a dramatic loss of sensitivity and the presence of peaks in the mass spectra corresponding to molecular ions in the coating. In contrast, the cationic HR coating gave faster but poorer glycoform separations due to the presence of an anodal EOF. However, the positive charge of the coating provided enhanced hydrolytic stability, making it more suitable than the LN coating for the on‐line MS coupling.
Identification of toxic oligopeptides in Amanita fungi employing capillary electrophoresis‐electrospray ionization‐mass spectrometry with positive and negative ion detection
Authors: Rittgen Jan , Pütz Michael , Pyell Ute 
Published: April 2008

AbstractThe identification of toxic oligopeptides employing CE‐ESI‐MS is presented. The analytes studied ama‐ and phallotoxins are of significant forensic interest because over 90% of the lethal cases of fungus poisoning in man are caused by species of Amanita which contain these toxins. A CE method was developed to separate the toxins α‐, β‐ and γ‐amanitin, phalloidin and phallacidin. Their fragmentation patterns in MSn experiments were investigated in the positive and in the negative ion mode, also the influence of the sheath liquid mixture of the used interface on the S/N. Method validation included the determination of the LOD and the repeatability of the migration time and peak area for both detection modes. With the optimized method LODs of 13–79 ng/mL (17–87 nmol/L) were reached. The CE‐MS procedure was successfully applied to the identification of ama‐ and phallotoxins in extracts of air‐dried mushroom samples.
The loudness dependence of the auditory evoked potential (LDAEP) as anin vivobiomarker of central serotonergic function in humans: rationale, evaluation and review of findings
Authors: O'Neill Barry V. , Croft Rodney J. , Nathan Pradeep J. 
Published: April 2008

AbstractObjectivesThe loudness dependence of the auditory evoked potential (LDAEP) has been proposed as a valid means of non‐invasively assessingin vivocentral serotonin (5‐hydroxytryptamine, 5‐HT) function in humans. The specificity and sensitivity of the LDAEP to changes in 5‐HT neurotransmission have recently been explored directly in a number of pharmacological and genetic studies. Subsequently, this review was undertaken in an attempt to critically evaluate the potential role of the LDAEP as a marker of the central 5‐HT function.DesignFindings from clinical, experimental animal and human studies examining the relationship between the LDAEP and the 5‐HT system as well as other neurochemical systems including dopaminergic, glutamatergic and the cholinergic systems were reviewed.ResultsThe majority of evidence for an association between the LDAEP and 5‐HT has come from animal studies. Indirect studies in clinical disorders of presumed serotonergic dysfunction have been circumstantial and inconsistent with more recent investigations utilising direct genetic association studies also providing conflicting reports. Pharmacological studies in humans provide overwhelming evidence that the LDAEP is insensitive to acute changes in 5‐HT function, with additional evidence outlining sensitivity to other neurotransmitter systems including the glutamatergic system.ConclusionsThe available evidence suggests that the LDAEP lacks sensitivity and specificity to acute changes in serotonergic neurotransmission. Overall the findings do not provide strong support for its utility as a marker of central 5‐HT function. However the LDAEP shows more promise as a potential predictor of antidepressant treatment response and this predictive ability may provide the basis for future research involving the LDAEP. Copyright © 2008 John Wiley & Sons, Ltd.
Executive function deficits in short‐term abstinent cannabis users
Authors: McHale Sue , Hunt Nigel 
Published: April 2008

AbstractObjectivesFew cognitive tasks are adequately sensitive to show the small decrements in performance in abstinent chronic cannabis users. In this series of three experiments we set out to demonstrate a variety of tasks that are sufficiently sensitive to show differences in visual memory, verbal memory, everyday memory and executive function between controls and cannabis users.MethodsA series of three studies explored cognitive function deficits in cannabis users (phonemic verbal fluency, visual recognition and immediate and delayed recall, and prospective memory) in short‐term abstinent cannabis users. Participants were selected using snowball sampling, with cannabis users being compared to a standard control group and a tobacco‐use control group.ResultsThe cannabis users, compared to both control groups, had deficits on verbal fluency, visual recognition, delayed visual recall, and short‐ and long‐interval prospective memory. There were no differences for immediate visual recall.ConclusionsThese findings suggest that cannabis use leads to impaired executive function. Further research needs to explore the longer term impact of cannabis use. Copyright © 2008 John Wiley & Sons, Ltd.
The use of effect sizes to characterize the nature of cognitive change in psychopharmacological studies: an example with scopolamine
Authors: Fredrickson Amy , Snyder Peter J. , Cromer Jennifer , Thomas Elizabeth , Lewis Matthew , Maruff Paul 
Published: April 2008

AbstractDrug induced cognitive change is generally investigated using small sample sizes. In terms of null hypothesis significance testing (NHST) this can render a meaningful change non‐significant, as a result of insufficient power in the statistical model. NHST leads to ‘all or none’ thinking, where a non‐significant result is interpreted as an absence of change. An effect size calculation indicates the magnitude of change which has occurred post‐intervention, and therefore whether a significant result is meaningful. We used a scopolamine challenge to demonstrate the usefulness of effect sizes. The aim of the study was to determine how effect sizes could describe the cognitive changes that occur following administration of subcutaneous scopolamine (s.c. scopolamine). Twenty four healthy young males (M = 32.6, sd = 4.5 years) were administered placebo and 0.2 mg, 0.4 mg & 0.6 mg of s.c. scopolamine using a 4‐way crossover design. Memory, learning, psychomotor function, attention and executive function were assessed. Scopolamine significantly impaired performance on all tasks in a dose and time related manner. These results demonstrate the functionality of change scores to draw comparisons between different times and doses. This methodology overcomes the limitations of comparisons between studies using different tasks, doses and time at which cognitive functions are measured. Copyright © 2008 John Wiley & Sons, Ltd.