97 research outputs found
Site-specific metal and ligand substitutions in a microporous Mn(2+)-based metal-organic framework
First published online 16 Feb 2016The precise tuning of the structural and chem. features of microporous metal-org. frameworks (MOFs) is a crucial endeavour for developing materials with properties that are suitable for specific applications. In recent times, techniques for prepg. frameworks consisting of mixed-metal or ligand compns. have emerged. However, controlled spatial organization of the components within these structures at the mol. scale is a difficult challenge, particularly when species possessing similar geometries or chem. properties are used. Here, we describe the synthesis of mixed-metal and ligand variants possessing the Mn3L3 (Mn-MOF-1; H2L = bis(4-(4'-carboxyphenyl)-3,5-dimethylpyrazolyl)methane) structure type. In the case of mixed-ligand synthesis using a mixt. of L and its trifluoromethyl-functionalised deriv. (H2L' = bis(4-(4'-carboxyphenyl)-3,5-di(trifluoromethyl)pyrazolyl)methane), a mixed-ligand product in which the L' species predominanantly occupies the pillar sites lining the pores is obtained. Meanwhile, post-synthetic metal exchange of the parent Mn3L3 compd. using Fe2+ or Fe3+ ions results in cation exchange at the carboxylate clusters and metalation at the pillar bispyrazolate sites. The results demonstrate the versatility of the Mn3L3 structure type toward both metal and ligand substitutions, and the potential utility of site-specific functionalisations in achieving even greater precision in the tuning of MOFs. [on SciFinder(R)]Michael Huxley, Campbell J. Coghlan, Alexandre Burgun, Andrew Tarzia, Kenji Sumida, Christopher J. Sumby, and Christian J. Doona
Production of cascade hypernuclei via the (K-,K+) reaction within a quark-meson coupling model
We study the production of bound cascade hypernuclei via the (K-,K+) reaction
on 12C and 28Si targets within a covariant effective Lagrangian model,
employing the cascade bound state spinors derived from the latest quark-meson
coupling model as well as Dirac single particle wave functions. The K+-cascade
production vertex is described by excitation, propagation and decay of Lambda
and Sigma resonance states in the initial collision of a K- meson with a target
proton in the incident channel. The parameters of the resonance vertices are
fixed by describing the available data on total and differential cross sections
for the cascade production in elementary (K-,K+) reaction. We find that both
the elementary and hypernuclear production cross sections are dominated by the
contributions from the Lambda(1520) intermediate resonant state. The 0 degree
differential cross sections for the formation of simple s-state cascade
particle-hole states peak at a beam momentum around 1.0 GeV/c, with a value in
excess of 1 mub.Comment: 17 pages, 8 figures, version accepted for publication in Nucl. Phys.
Measurements of KL Branching Fractions and the CP Violation Parameter |eta+-|
We present new measurements of the six largest branching fractions of the KL
using data collected in 1997 by the KTeV experiment (E832) at Fermilab. The
results are B(KL -> pi e nu) = 0.4067 +- 0.0011 B(KL -> pi mu nu) = 0.2701 +-
0.0009 B(KL -> pi+ pi- pi0) = 0.1252 +- 0.0007 B(KL -> pi0 pi0 pi0) = 0.1945 +-
0.0018 B(KL -> pi+ pi-) = (1.975 +- 0.012)E-3, and B(KL -> pi0 pi0) = (0.865 +-
0.010)E-3, where statistical and systematic errors have been summed in
quadrature. We also determine the CP violation parameter |eta+-| to be (2.228
+- 0.010)E-3. Several of these results are not in good agreement with averages
of previous measurements.Comment: Submitted to Phys. Rev. D; 20 pages, 22 figure
Phenomenological model for the Kbar N --> K Xi reaction
A phenomenological model for the Kbar N --> K Xi reaction is suggested. The
model includes s and u channel exchanges by Lambda, Sigma, Sigma(1385), and
Lambda(1520) and s channel exchanges by above-threshold hyperonic resonances.
Explicit expression for the propagator for a particle with spin 7/2 is
presented. High-mass and high-spin resonances play a significant role in the
process. We deal with the whole set of existing experimental data on the cross
sections and polarizations in the energy range from the threshold to 2.8 GeV in
the center-of-mass system and reach a good agreement with experiments.
Applications of the model to other elementary reactions of Xi production and to
Xi hypernuclear spectroscopy are briefly discussed.Comment: Published version; minor change
TargetMine, an Integrated Data Warehouse for Candidate Gene Prioritisation and Target Discovery
Prioritising candidate genes for further experimental characterisation is a
non-trivial challenge in drug discovery and biomedical research in general. An
integrated approach that combines results from multiple data types is best
suited for optimal target selection. We developed TargetMine, a data warehouse
for efficient target prioritisation. TargetMine utilises the InterMine
framework, with new data models such as protein-DNA interactions integrated in a
novel way. It enables complicated searches that are difficult to perform with
existing tools and it also offers integration of custom annotations and in-house
experimental data. We proposed an objective protocol for target prioritisation
using TargetMine and set up a benchmarking procedure to evaluate its
performance. The results show that the protocol can identify known
disease-associated genes with high precision and coverage. A demonstration
version of TargetMine is available at http://targetmine.nibio.go.jp/
International comparisons of laboratory values from the 4CE collaborative to predict COVID-19 mortality
Given the growing number of prediction algorithms developed to predict COVID-19 mortality, we evaluated the transportability of a mortality prediction algorithm using a multi-national network of healthcare systems. We predicted COVID-19 mortality using baseline commonly measured laboratory values and standard demographic and clinical covariates across healthcare systems, countries, and continents. Specifically, we trained a Cox regression model with nine measured laboratory test values, standard demographics at admission, and comorbidity burden pre-admission. These models were compared at site, country, and continent level. Of the 39,969 hospitalized patients with COVID-19 (68.6% male), 5717 (14.3%) died. In the Cox model, age, albumin, AST, creatine, CRP, and white blood cell count are most predictive of mortality. The baseline covariates are more predictive of mortality during the early days of COVID-19 hospitalization. Models trained at healthcare systems with larger cohort size largely retain good transportability performance when porting to different sites. The combination of routine laboratory test values at admission along with basic demographic features can predict mortality in patients hospitalized with COVID-19. Importantly, this potentially deployable model differs from prior work by demonstrating not only consistent performance but also reliable transportability across healthcare systems in the US and Europe, highlighting the generalizability of this model and the overall approach
Long-term kidney function recovery and mortality after COVID-19-associated acute kidney injury: An international multi-centre observational cohort study
Background: While acute kidney injury (AKI) is a common complication in COVID-19, data on post-AKI kidney function recovery and the clinical factors associated with poor kidney function recovery is lacking. Methods: A retrospective multi-centre observational cohort study comprising 12,891 hospitalized patients aged 18 years or older with a diagnosis of SARS-CoV-2 infection confirmed by polymerase chain reaction from 1 January 2020 to 10 September 2020, and with at least one serum creatinine value 1–365 days prior to admission. Mortality and serum creatinine values were obtained up to 10 September 2021. Findings: Advanced age (HR 2.77, 95%CI 2.53–3.04, p < 0.0001), severe COVID-19 (HR 2.91, 95%CI 2.03–4.17, p < 0.0001), severe AKI (KDIGO stage 3: HR 4.22, 95%CI 3.55–5.00, p < 0.0001), and ischemic heart disease (HR 1.26, 95%CI 1.14–1.39, p < 0.0001) were associated with worse mortality outcomes. AKI severity (KDIGO stage 3: HR 0.41, 95%CI 0.37–0.46, p < 0.0001) was associated with worse kidney function recovery, whereas remdesivir use (HR 1.34, 95%CI 1.17–1.54, p < 0.0001) was associated with better kidney function recovery. In a subset of patients without chronic kidney disease, advanced age (HR 1.38, 95%CI 1.20–1.58, p < 0.0001), male sex (HR 1.67, 95%CI 1.45–1.93, p < 0.0001), severe AKI (KDIGO stage 3: HR 11.68, 95%CI 9.80–13.91, p < 0.0001), and hypertension (HR 1.22, 95%CI 1.10–1.36, p = 0.0002) were associated with post-AKI kidney function impairment. Furthermore, patients with COVID-19-associated AKI had significant and persistent elevations of baseline serum creatinine 125% or more at 180 days (RR 1.49, 95%CI 1.32–1.67) and 365 days (RR 1.54, 95%CI 1.21–1.96) compared to COVID-19 patients with no AKI. Interpretation: COVID-19-associated AKI was associated with higher mortality, and severe COVID-19-associated AKI was associated with worse long-term post-AKI kidney function recovery. Funding: Authors are supported by various funders, with full details stated in the acknowledgement section
Synthesis, isomerisation and biological properties of mononuclear ruthenium complexes containing the bis[4(4 '-methyl-2,2 '-bipyridyl)]-1,7-heptane ligand
A series of mononuclear ruthenium(II) complexes containing the tetradentate ligand bis[4(4’-methyl-2,2’-
bipyridyl)]-1,7-heptane have been synthesised and their biological properties examined. In the synthesis
of the [Ru(phen’)(bb7)]2+ complexes (where phen’ = 1,10-phenanthroline and its 5-nitro-, 4,7-dimethyland
3,4,7,8-tetramethyl- derivatives), both the symmetric cis-α and non-symmetric cis-β isomers
were formed. However, upon standing for a number of days (or more quickly under harsh conditions) the
cis-β isomer converted to the more thermodynamically stable cis-α isomer. The minimum inhibitory concentrations
(MIC) and the minimum bactericidal concentrations (MBC) of the ruthenium(II) complexes
were determined against six strains of bacteria: Gram-positive Staphylococcus aureus (S. aureus) and
methicillin-resistant S. aureus (MRSA); and the Gram-negative Escherichia coli (E. coli) strains MG1655,
APEC, UPEC and Pseudomonas aeruginosa (P. aeruginosa). The results showed that the [Ru(5-NO2phen)-
(bb7)]2+ complex had little or no activity against any of the bacterial strains. By contrast, for the other cisα-[Ru(phen’)(bb7)]2+
complexes, the antimicrobial activity increased with the degree of methylation. In
particular, the cis-α-[Ru(Me4phen)(bb7)]2+ complex showed excellent and uniform MIC activity against all
bacteria. By contrast, the MBC values for the cis-α-[Ru(Me4phen)(bb7)]2+ complex varied considerably
across the bacteria and even within S. aureus and E. coli strains. In order to gain an understanding of the
relative antimicrobial activities, the DNA-binding affinity, cellular accumulation and water–octanol partition
coefficients (log P) of the ruthenium complexes were determined. Interestingly, all the [Ru(phen’)-
(bb7)]2+ complexes exhibited stronger DNA binding affinity (Ka ≈ 1 × 107 M−1
) than the well-known DNAintercalating
complex [Ru(phen)2(dppz)]2+ (where dppz = dipyrido[3,2-a:2’,3’-c]phenazine)
Biomedical informatics and translational medicine
Biomedical informatics involves a core set of methodologies that can provide a foundation for crossing the "translational barriers" associated with translational medicine. To this end, the fundamental aspects of biomedical informatics (e.g., bioinformatics, imaging informatics, clinical informatics, and public health informatics) may be essential in helping improve the ability to bring basic research findings to the bedside, evaluate the efficacy of interventions across communities, and enable the assessment of the eventual impact of translational medicine innovations on health policies. Here, a brief description is provided for a selection of key biomedical informatics topics (Decision Support, Natural Language Processing, Standards, Information Retrieval, and Electronic Health Records) and their relevance to translational medicine. Based on contributions and advancements in each of these topic areas, the article proposes that biomedical informatics practitioners ("biomedical informaticians") can be essential members of translational medicine teams
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