4,145 research outputs found
Structural Simplification of Bedaquiline: the Discovery of 3-(4-(N,N-dimethylaminomethyl)phenyl)quinoline Derived Antitubercular Lead Compounds
Bedaquiline (BDQ) is a novel and highly potent last-line antituberculosis drug that was approved by the US FDA in 2013. Owing to its stereo-structural complexity, chemical synthesis and compound optimization are rather difficult and expensive. This study describes the structural simplification of bedaquiline while preserving antitubercular activity. The compound's structure was split into fragments and reassembled in various combinations while replacing the two chiral carbon atoms with an achiral linkage instead. Four series of analogues were designed; these candidates retained their potent antitubercular activity at sub-microgram per mL concentrations against both sensitive and multidrug-resistant (MDR) Mycobacterium tuberculosis strains. Six out of the top nine MIC-ranked candidates were found to inhibit mycobacterial ATP synthesis activity with IC50 values between 20 and 40 μm, one had IC50>66 μm, and two showed no inhibition, despite their antitubercular activity. These results provide a basis for the development of chemically less complex, lower-cost bedaquiline derivatives and describe the identification of two derivatives with antitubercular activity against non-ATP synthase related targets
Gabriel Triangulations and Angle-Monotone Graphs: Local Routing and Recognition
A geometric graph is angle-monotone if every pair of vertices has a path
between them that---after some rotation---is - and -monotone.
Angle-monotone graphs are -spanners and they are increasing-chord
graphs. Dehkordi, Frati, and Gudmundsson introduced angle-monotone graphs in
2014 and proved that Gabriel triangulations are angle-monotone graphs. We give
a polynomial time algorithm to recognize angle-monotone geometric graphs. We
prove that every point set has a plane geometric graph that is generalized
angle-monotone---specifically, we prove that the half--graph is
generalized angle-monotone. We give a local routing algorithm for Gabriel
triangulations that finds a path from any vertex to any vertex whose
length is within times the Euclidean distance from to .
Finally, we prove some lower bounds and limits on local routing algorithms on
Gabriel triangulations.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
Deep Impression: Audiovisual Deep Residual Networks for Multimodal Apparent Personality Trait Recognition
Here, we develop an audiovisual deep residual network for multimodal apparent
personality trait recognition. The network is trained end-to-end for predicting
the Big Five personality traits of people from their videos. That is, the
network does not require any feature engineering or visual analysis such as
face detection, face landmark alignment or facial expression recognition.
Recently, the network won the third place in the ChaLearn First Impressions
Challenge with a test accuracy of 0.9109
Unique pattern of infections in chronic granulomatous disease – The Asian experience
Conference Theme: Inflammatory Basis of Perinatal and Childhood DiseasesSymposium 40: InfectionBackground: Chronic granulomatous disease (CGD) is a phagocytic disorder
caused by defective NADPH oxidase activity. Affected individuals are susceptible
to bacterial infections, mycosis and hyperinflammatory complications. Variations
in the epidemiology of infectious diseases across geographical regions can lead
to distinct clinical phenotypes.
Objective: To identify the unique clinical characteristics of a large cohort of CGD
patients in China and Southeast Asia referred for genetic studies from 2003 to
2012.
Methods: 53 patients with genetically-confirmed CGD were included and their
clinical features were analyzed. CYBB and CYBA mutations were studied by
Sanger sequencing, and NCF1 ‘GT’ deletion hotspot mutation was studied on
genomic DNA by GeneScan.
Results: 44 patients with X-CGD had CYBB mutations (missense[n=16];
nonsense[n=8]; deletion[n=9]; insertion[n=2]; intron mutation[n=9]). Nine
patient had AR-CGD (CYBA[n=5]; NCF1 75_76delGT[n=4]). The median age at
presentation and diagnosis was higher in AR-CGD (7m and 66m) compared with
X-CGD (3m and 22m). The commonest presentations were pneumonia (58%), skin and perianal abscess (49%), lymphadenitis (42%) and recurrent diarrhea (30%).
Aspergillosis and salmonellosis occurred at a frequency similar to published
studies (13% and 19% respectively), but the commonest infection was BCG (43%)
and 11% had disseminated BCG. 21% of patients had tuberculosis. Fulminant
melioidosis and Chromobacterium violaceum infections occurred in 3 patients
and two of their male siblings. Hyperinflammatory conditions included polyarthritis
(n=3) and pulmonary granuloma (n=2). Death was recorded in 8 patients (15%).
Conclusion: Melioidosis and C. violaceum indigenous to Southeast Asia can cause
life-threatening infections in CGD patients. The high incidence of mycobacterial
infections is associated with universal BCG vaccination and endemicity of
tuberculosis. Such observations emphasize the role of respiratory burst as an
immune defense mechanism against these pathogens. These infections are
seldom reported in Caucasian cohorts, illustrating the importance of regional
collaborative studies to facilitate pattern recognition and early diagnosis of
primary immunodeficiencies.published_or_final_versio
First observation of psi(2S)-->K_S K_L
The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data
collected with the Beijing Spectrometer (BESII) at the Beijing Electron
Positron Collider (BEPC); the branching ratio is determined to be
B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with
J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the
prediction of the perturbative QCD ``12%'' rule. The result, together with the
branching ratios of psi(2S) decays to other pseudoscalar meson pairs
(\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the
three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let
Mapping species distributions: A comparison of skilled naturalist and lay citizen science recording
To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UK’s national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. For the widespread common carder (Bombus pascuorum), traditional recording scheme data were patchy, both spatially and temporally, reflecting active record centre rather than species distribution. Lay citizen science records displayed more extensive geographic coverage, reflecting human population density, thus offering better opportunities to account for recording effort. For the rapidly spreading tree bumblebee (Bombus hypnorum), both recording approaches revealed similar distributions due to a dedicated mapping project which overcame the patchy nature of naturalist records. We recommend, where possible, complementing skilled naturalist recording with lay citizen science programmes to obtain a nation-wide capability, and stress the need for timely uploading of data to the national repository
The protective effect of ginko bilboa leaves injection on the brain dopamine in the rat model of cerebral ischemia/reperfusion injury
Background: Ginkgo Bilboa injection has had been clinically applied to restore the damaged cells and tissues due to the ischemia through improving the cerebral blood supply and decreasing the oxygen consumption.ObjectiveAim: To evaluate the Ginkgo Bilboa injection's therapeutic role towards ischemia/ reperfusion (I/R) injury through determination of monoamine neurotransmitter dopamine (DA) in corpus striatum.Methods: After the incomplete global cerebral ischemia and reperfusion models were prepared, rats were randomly assigned into four groups: sham-operated group, ischemia-reperfusion group, nimodipine injection group, and Ginkgo Biloba injection group. The cerebrospinal fluid in the rat brain striatum at different time points was collected with microdialysis, and the level of monoamine neurotransmitters dopamineDA was determined by high performance liquid chromatography (HPLC) with electrochemical detector (ECD).Results: The dopamineDA content in cerebral ischemia model group was significantly higher than that in the sham-operated group (P<0.05) at the 30 min. However, the DA level in nimodipine injection group and Ginkgo Biloba injection group were lower than the model group (P<0.05). The dopamineDA level in Ginkgo Biloba injection group gradually decreased, and was significantly different from the model group (P<0.05).Conclusion: Ginkgo Biloba injection can could significantly inhibit brain I/R injury, as demonstrated by prevention of excessive release of dopamineDA in striatum.Key Words: MD-HPLC-ECD; Ginkgo Biloba injection; ischemia/reperfusion; dopamineD
Detecting the direction of a signal on high-dimensional spheres: Non-null and Le Cam optimality results
We consider one of the most important problems in directional statistics,
namely the problem of testing the null hypothesis that the spike direction
of a Fisher-von Mises-Langevin distribution on the -dimensional
unit hypersphere is equal to a given direction . After a reduction
through invariance arguments, we derive local asymptotic normality (LAN)
results in a general high-dimensional framework where the dimension goes
to infinity at an arbitrary rate with the sample size , and where the
concentration behaves in a completely free way with , which
offers a spectrum of problems ranging from arbitrarily easy to arbitrarily
challenging ones. We identify various asymptotic regimes, depending on the
convergence/divergence properties of , that yield different
contiguity rates and different limiting experiments. In each regime, we derive
Le Cam optimal tests under specified and we compute, from the Le Cam
third lemma, asymptotic powers of the classical Watson test under contiguous
alternatives. We further establish LAN results with respect to both spike
direction and concentration, which allows us to discuss optimality also under
unspecified . To investigate the non-null behavior of the Watson test
outside the parametric framework above, we derive its local asymptotic powers
through martingale CLTs in the broader, semiparametric, model of rotationally
symmetric distributions. A Monte Carlo study shows that the finite-sample
behaviors of the various tests remarkably agree with our asymptotic results.Comment: 47 pages, 4 figure
Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0
Using 58 million J/psi and 14 million psi' decays obtained by the BESII
experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The
result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous
measurements.Comment: 9 pages, 8 figures, RevTex
Pharmacological levels of withaferin A (Withania somnifera) trigger clinically relevant anticancer effects specific to triple negative breast cancer cells
Withaferin A (WA) isolated from Withania somnifera (Ashwagandha) has recently become an attractive phytochemical under investigation in various preclinical studies for treatment of different cancer types. In the present study, a comparative pathway-based transcriptome analysis was applied in epithelial-like MCF-7 and triple negative mesenchymal MDA-MB-231 breast cancer cells exposed to different concentrations of WA which can be detected systemically in in vivo experiments. Whereas WA treatment demonstrated attenuation of multiple cancer hallmarks, the withanolide analogue Withanone (WN) did not exert any of the described effects at comparable concentrations. Pathway enrichment analysis revealed that WA targets specific cancer processes related to cell death, cell cycle and proliferation, which could be functionally validated by flow cytometry and real-time cell proliferation assays. WA also strongly decreased MDA-MB-231 invasion as determined by single-cell collagen invasion assay. This was further supported by decreased gene expression of extracellular matrix-degrading proteases (uPA, PLAT, ADAM8), cell adhesion molecules (integrins, laminins), pro-inflammatory mediators of the metastasis-promoting tumor microenvironment (TNFSF12, IL6, ANGPTL2, CSF1R) and concomitant increased expression of the validated breast cancer metastasis suppressor gene (BRMS1). In line with the transcriptional changes, nanomolar concentrations of WA significantly decreased protein levels and corresponding activity of uPA in MDA-MB-231 cell supernatant, further supporting its anti-metastatic properties. Finally, hierarchical clustering analysis of 84 chromatin writer-reader-eraser enzymes revealed that WA treatment of invasive mesenchymal MDA-MB-231 cells reprogrammed their transcription levels more similarly towards the pattern observed in non-invasive MCF-7 cells. In conclusion, taking into account that sub-cytotoxic concentrations of WA target multiple metastatic effectors in therapy-resistant triple negative breast cancer, WA-based therapeutic strategies targeting the uPA pathway hold promise for further (pre)clinical development to defeat aggressive metastatic breast cancer
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