2,784 research outputs found
Manganese carbonyl complexes of 2,5-dimethylbismolyl. The crystal and molecular structure of ([eta]1-2,5-dimethylbismolyl) manganese pentacarbonyl
([eta]-1-2,5-Dimethylbismolyl)manganese pentacarbonyl (8) has been obtained from the reaction of 1-phenyl-2,5-dimethylbismole with lithium followed by BrMn(CO)5. Heating 8 to its melting point causes the loss of CO to produce ([eta]5-2,5-dimethylbismolyl)manganese tricarbonyl. Compound 8 crystallizes in the monoclinic crystal system, space group P 21 (No. 4) with a = 6.838(2) A, b = 6.424(1) A, c = 15.787(4) A, [beta] = 95.68(2)[deg] V= 6901.(2) A3 and Z = 2. A full structure has been determined and is compared with those of analogous compounds.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30847/1/0000509.pd
Evidence for the Role of B Cells and Immunoglobulins in the Pathogenesis of Multiple Sclerosis
The pathogenesis of multiple sclerosis (MS) remains elusive. Recent reports advocate greater involvement of B cells and immunoglobulins in the initiation and propagation of MS lesions at different stages of their ontogeny. The key role of B cells and immunoglobulins in pathogenesis was initially identified by studies in which patients whose fulminant attacks of demyelination did not respond to steroids experienced remarkable functional improvement following plasma exchange. The positive response to Rituximab in Phase II clinical trials of relapsing-remitting MS confirms the role of B cells. The critical question is how B cells contribute to MS. In this paper, we discuss both the deleterious and the beneficial roles of B cells and immunoglobulins in MS lesions. We provide alternative hypotheses to explain both damaging and protective antibody responses
Baseline patient characteristics associated with response to biologic therapy in patients with psoriatic arthritis enrolled in the Corrona Psoriatic Arthritis/Spondyloarthritis Registry.
Objectives: To compare baseline characteristics between patients with psoriatic arthritis (PsA) who achieved and did not achieve minimal disease activity (MDA) with biologic therapy in the US-based Corrona Psoriatic Arthritis/Spondyloarthritis Registry.
Methods: Patients with PsA aged â„18 years enrolled between March 2013 and March 2016 who were receiving biologics at enrolment (baseline), not in MDA and had â„2âfollow-up visits were included. Patients were classified as those who remained on their index biologic and achieved MDA at the second follow-up visit (MDA achievers (MDA-A)) and those who did not (MDA non-achievers (MDA-NA)). Demographics, clinical characteristics, patient-reported outcomes and medication history were compared between groups.
Results: Of 148 patients with PsA who met the inclusion criteria, 34 (23.0%) and 114 (77.0%) were classified as MDA-A and MDA-NA, respectively. At baseline, most patients (96.6%) were receiving tumour necrosis factor inhibitors, and both groups were similar in age, sex, race, medication history, enthesitis and dactylitis counts, disease duration and comorbidities. Compared with MDA-A, MDA-NA had significantly worse mean tender joint count (7.2 vs 3.4), patient-reported pain (51.2 vs 35.7), patient-reported fatigue (54.1 vs 42.4), physical function (Health Assessment Questionnaire, 1.0 vs 0.6), Bath Ankylosing Disease Activity Index (5.0 vs 3.4) and Bath Ankylosing Spondylitis Functional Index (4.0 vs 2.0) scores (all p\u3c0.05).
Conclusions: Approximately one in four patients achieved MDA with their index biologic at the time of the second follow-up visit. Both groups were similar in several baseline demographic and clinical features; however, patients who did not achieve MDA generally had worse tender joint counts and patient-reported outcomes
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Bonding, Backbonding, and Spin-Polarized Molecular Orbitals:Basis for Magnetism and Semiconducting Transport in V[TCNE]x~;;2
X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) at the V L2,3 and C and N K edges reveal bonding/backbonding interactions in films of the 400 K magnetic semiconductor V[TCNE]x~;;2. In V spectra, dxy-like orbitals are modeled assuming V2+ in an octahedral ligand field, while dz2 and dx2-y2 orbitals involved in strong covalent bonding cannot be modeled by atomic calculations. C and N MCD, and differences in XAS from neutral TCNE molecules, reveal spin-polarized molecular orbitals in V[TCNE]x~;;2 associated with backbonding interactions that yield its novel properties
The Discovery of a Second Field Methane Brown Dwarf from Sloan Digital Sky Survey Commissioning Data
We report the discovery of a second field methane brown dwarf from the
commissioning data of the Sloan Digital Sky Survey (SDSS). The object, SDSS
J134646.45-003150.4 (SDSS 1346-00), was selected because of its very red color
and stellar appearance. Its spectrum between 0.8-2.5 mic is dominated by strong
absorption bands of H_2O and CH_4 and closely mimics those of Gliese 229B and
SDSS 162414.37+002915.6 (SDSS 1624+00), two other known methane brown dwarfs.
SDSS 1346-00 is approximately 1.5 mag fainter than Gliese 229B, suggesting that
it lies about 11 pc from the sun. The ratio of flux at 2.1 mic to that at 1.27
mic is larger for SDSS 1346-00 than for Gliese 229B and SDSS 1624+00, which
suggests that SDSS 1346-00 has a slightly higher effective temperature than the
others. Based on a search area of 130 sq. deg. and a detection limit of z* =
19.8, we estimate a space density of 0.05 pc^-3 for methane brown dwarfs with
T_eff ~ 1000 K in the 40 pc^3 volume of our search. This estimate is based on
small-sample statistics and should be treated with appropriate caution.Comment: 9 pages, 3 figures, AASTeX, to appear in ApJ Letters, authors list
update
Prevalence of intestinal microsporidiosis in Human Immunodeficiency Virus-infected patients with diarrhea in major United States cities
To determine the prevalence of intestinal microsporidiosis in HIV-infected patients, we performed a prospective study of HIV-infected patients with diarrheal illnesses in three US hospitals and examined an observational database of HIV-infected patients in 10 US cities. Among 737 specimens from the three hospitals, results were positive for 11 (prevalence 1.5%); seven (64%) acquired HIV through male-to-male sexual contact, two (18%) through male-to-male sexual contact and injection drug use, and one (9%) through heterosexual contact; one (9%) had an undetermined mode of transmission. Median CD4 count within six months of diagnosis of microsporidiosis was 33 cells/”L (range 3 to 319 cells/”L). For the national observational database (n = 24,098), the overall prevalence of microsporidiosis was 0.16%. Prevalence of microsporidiosis among HIV-infected patients with diarrheal disease is low, and microsporidiosis is most often diagnosed in patients with very low CD4+ cell counts. Testing for microsporidia appears to be indicated, especially for patients with very low CD4+ cell counts.Para determinar a prevalĂȘncia de microsporidiose intestinal em pacientes infectados pelo HIV foi realizado um estudo prospectivo em trĂȘs hospitais dos Estados Unidos da AmĂ©rica do Norte (EUA) e analizada uma base de dados nacional composta de dados coletados de pacientes infectados pelo HIV em 10 cidades dos EUA. De um total de 737 amostras de fezes de pacientes infectados pelo HIV que apresentavam diarrĂ©ia, amostras de 11 pacientes (prevalĂȘncia de 1,5%) foram positivas para microsporĂdios. Todos os positivos eram do sexo masculino e, entre eles, sete (64%) pacientes adquiriram a infecção pelo HIV atravĂ©s de relação homossexual, dois (18%) atravĂ©s de relação sexual e drogas injetĂĄveis e um (9%) atravĂ©s de contato heterosexual, enquanto que em um paciente o modo de transmissĂŁo do HIV nĂŁo foi determinado. A contagem mĂ©dia de linfĂłcitos CD4 realizada atĂ© seis meses do diagnĂłstico de microsporidiose foi de 33 cĂ©lulas/microlitro (3 a 319 cĂ©lulas/microlitro). A anĂĄlise da base de dados nacional (n = 24.098) mostrou uma prevalĂȘncia de microsporidiose de 0,16%. A prevalĂȘncia de microsporidiose em pacientes HIV-positivos com diarrĂ©ia Ă© baixa. Entretando, como a microsporidiose Ă© mais frequentemente diagnosticada em pacientes com contagens de CD4 muito baixas, a indicação de pesquisa de microsporĂdios Ă© justificada, especialmente para estes pacientes
Conservative When Crowded: Social Crowding and Consumer Choice
This is the published version. Copyright 2013 by American Marketing Association.Does the mere crowdedness of the environment affect people's choices and preferences? In six studies, the authors show that social crowdedness not only leads to greater accessibility of safety-related constructs but also results in greater preference for safety-oriented options (e.g., preferring to visit a pharmacy to a convenience store), being more receptive to prevention- (rather than promotion-) framed messages, and being more risk averse with real money gambles. In support of the authors' underlying avoidance motivation perspective, these effects are mediated by participants' net prevention focus and are attenuated when the crowd in question consists of in-group members. The authors close by discussing the practical and theoretical implications of the results
NMR and MetabolomicsâA Roadmap for the Future
Metabolomics investigates global metabolic alterations associated with chemical, biological, physiological, or pathological processes. These metabolic changes are measured with various analytical platforms including liquid chromatography-mass spectrometry (LC-MS), gas chromatographymass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). While LC-MS methods are becoming increasingly popular in the field of metabolomics (accounting for more than 70% of published metabolomics studies to date), there are considerable benefits and advantages to NMR-based methods for metabolomic studies. In fact, according to PubMed, more than 926 papers on NMR-based metabolomics were published in 2021âthe most ever published in a given year. This suggests that NMR-based metabolomics continues to grow and has plenty to offer to the scientific community. This perspective outlines the growing applications of NMR in metabolomics, highlights several recent advances in NMR technologies for metabolomics, and provides a roadmap for future advancements
Faint High Latitude Carbon Stars Discovered by the Sloan Digital Sky Survey: Methods and Initial Results
We report the discovery of 39 Faint High Latitude Carbon Stars (FHLCs) from
Sloan Digital Sky Survey commissioning data. The objects, each selected
photometrically and verified spectroscopically, range over 16.6 < r* < 20.0,
and show a diversity of temperatures as judged by both colors and NaD line
strengths. At the completion of the Sloan Survey, there will be many hundred
homogeneously selected and observed FHLCs in this sample. We present proper
motion measures for each object, indicating that the sample is a mixture of
extremely distant (>100 kpc) halo giant stars, useful for constraining halo
dynamics, plus members of the recently-recognized exotic class of very nearby
dwarf carbon (dC) stars. Motions, and thus dC classification, are inferred for
40-50 percent of the sample, depending on the level of statistical significance
invoked. The new list of dC stars presented here, although selected from only a
small fraction of the final SDSS, doubles the number of such objects found by
all previous methods. (Abstract abridged).Comment: Accepted for publication in The Astronomical Journal, Vol. 124, Sep.
2002, 40 pages, 7 figures, AASTeX v5.
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