BACKGROUND AND PURPOSE—We aimed to investigate the ability of machine learning (ML) techniques analyzing diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) magnetic ...resonance imaging to identify patients within the recommended time window for thrombolysis.
METHODS—We analyzed DWI and FLAIR images of consecutive patients with acute ischemic stroke within 24 hours of clear symptom onset by applying automatic image processing approaches. These processes included infarct segmentation, DWI, and FLAIR imaging registration and image feature extraction. A total of 89 vector features from each image sequence were captured and used in the ML. Three ML models were developed to estimate stroke onset time for binary classification (≤4.5 hours)logistic regression, support vector machine, and random forest. To evaluate the performance of ML models, the sensitivity and specificity for identifying patients within 4.5 hours were compared with the sensitivity and specificity of human readings of DWI-FLAIR mismatch.
RESULTS—Data from a total of 355 patients were analyzed. DWI-FLAIR mismatch from human readings identified patients within 4.5 hours of symptom onset with 48.5% sensitivity and 91.3% specificity. ML algorithms had significantly greater sensitivities than human readers (75.8% for logistic regression, P=0.020; 72.7% for support vector machine, P=0.033; 75.8% for random forest, P=0.013) in detecting patients within 4.5 hours, but their specificities were comparable (82.6% for logistic regression, P=0.157; 82.6% for support vector machine, P=0.157; 82.6% for random forest, P=0.157).
CONCLUSIONS—ML algorithms using multiple magnetic resonance imaging features were feasible even more sensitive than human readings in identifying patients with stroke within the time window for acute thrombolysis.
A polysaccharide named GSP-2 with a molecular size of 32 kDa was isolated from the fruiting bodies of Ganoderma sinense. Its structure was well elucidated, by a combined utilization of chemical and ...spectroscopic techniques, to be a β-glucan with a backbone of (1→4)- and (1→6)-Glcp, bearing terminal- and (1→3)-Glcp side-chains at O-3 position of (1→6)-Glcp. Immunological assay exhibited that GSP-2 significantly induced the proliferation of BALB/c mice splenocytes with target on only B cells, and enhanced the production of several cytokines in human peripheral blood mononuclear cells and derived dendritic cells. Besides, the fluorescent labeled GSP-2 was phagocytosed by the RAW 264.7 cells and induced the nitric oxide secretion from the cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper presents a new functionality for high-power battery chargers by incorporating an impedance measurement algorithm. The measurement of battery impedance can be performed by the battery ...charger to provide an accurate equivalent model for battery management purposes. In this paper, an extended control capability of the onboard battery charger for electric vehicles is used to measure the online impedance of the battery. The impedance of the battery is measured by the following: 1) injecting ac current ripple on top of the dc charging current; 2) transforming voltage and current signals using a virtual α-β stationary coordinate system, a d-q rotating coordinate system, and two filtering systems; 3) calculating ripple voltage and current values; and 4) calculating the angle and magnitude of the impedance. The contributions of this paper are the use of the d-q transformation to attain the battery impedance, theta, and its ripple power, as well as providing a controller design procedure which has impedance measurement capability. The online impedance information can be utilized for diverse applications such as the following: 1) a theta control for sinusoidal current charging; 2) the quantifying of reactive current and voltage; 3) ascertaining the state of charge; 4) determining the state of health; and 5) finding the optimized charging current. Therefore, the benefit of this method is that it can be deployed in already existing high-power chargers regardless of battery chemistry. Validations of the proposed approach were made by comparing measurement values by using a battery charger and a commercial frequency response analyzer.
...23,213 patients with HZ, and the same number of propensity score-matched control subjects were analyzed. VZV is the only virus for which there is clear evidence of viral DNA and antigen in areas ...of ischemia or infarction in cerebral arteries (3). ...the diagnosis of HZ such as the presence of VZV in the saliva of patients with HZ is more direct than that of chlamydia infection, which was largely based on serology. ...we have demonstrated that HZ significantly increases the risk of stroke and MI even after rigorously adjusting possible confounding factors in a large population cohort. The Composite of Cardiovascular Events Stroke Myocardial Infarction Hazard Ratio (95% CI) p Value Hazard Ratio (95% CI) p Value Hazard Ratio (95% CI) p Value Unadjusted analysis∗ 1.68 (1.55-1.82) <0.001 1.65 (1.50-1.82) <0.001 1.68 (1.45-1.95) <0.001 Multivariate analysis† 1.22 (1.12-1.32) <0.001 1.18 (1.07-1.30) 0.001 1.25 (1.08-1.46) 0.003 Propensity-score matching analysis 1.41 (1.25-1.59) <0.001 1.35 (1.18-1.54) <0.001 1.59 (1.27-2.01) <0.001 Age, yrs ~40 2.42 (1.26-4.66) 0.008 3.74 (1.51-9.25) 0.004 1.45 (0.54-3.90) 0.464 41~50 1.63 (1.16-2.28) 0.005 1.49 (1.00-2.22) 0.052 1.47 (0.84-2.55) 0.177 51~60 1.53 (1.21-1.94) <0.001 1.39 (1.05-1.84) 0.022 1.96 (1.28-2.99) 0.002 61~70 1.24 (1.02-1.50) 0.030 1.25 (1.01-1.54) 0.038 1.24 (0.82-1.86) 0.306 71~...
Cyclodextrins (CDs) have drawn a lot of attention from the scientific communities as a model system for host-guest chemistry and also due to its variety of applications in the pharmaceutical, ...cosmetic, food, textile, separation science, and essential oil industries. The formation of the inclusion complexes enables these applications in the condensed phases, which have been confirmed by nuclear magnetic resonance (NMR) spectroscopy, X-ray crystallography, and other methodologies. The advent of soft ionization techniques that can transfer the solution-phase noncovalent complexes to the gas phase has allowed for extensive examination of these complexes and provides valuable insight into the principles governing the formation of gaseous noncovalent complexes. As for the CDs' host-guest chemistry in the gas phase, there has been a controversial issue as to whether noncovalent complexes are inclusion conformers reflecting the solution-phase structure of the complex or not. In this review, the basic principles governing CD's host-guest complex formation will be described. Applications and structures of CDs in the condensed phases will also be presented. More importantly, the experimental and theoretical evidence supporting the two opposing views for the CD-guest structures in the gas phase will be intensively reviewed. These include data obtained via mass spectrometry, ion mobility measurements, infrared multiphoton dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations.
Platinum-based drugs have revolutionized cancer care, but are unfortunately associated with various adverse effects. Meanwhile, natural product scaffolds exhibit multifarious bioactivities and serve ...as an attractive resource for cancer therapy development. Thus, the conjugation of natural product scaffolds to metal complexes becomes an attractive strategy to reduce the severe side effects arising from the use of metal bearing drugs. This review aims to highlight the recent examples of natural product-conjugated metal complexes as cancer therapies with enhanced selectivity and efficacy. We discuss the mechanisms and features of different conjugate complexes and present an outlook and perspective for the future of this field.
Serum alkaline phosphatase (ALP) is a marker of vascular calcification. A high serum ALP level is associated with an increase in cardiovascular events, and predicts poor functional outcome in ...patients with stroke. We investigated whether serum ALP was associated with cerebral small vessel disease (cSVD) and large cerebral artery stenosis (LCAS).
We evaluated vascular risk factors, brain magnetic resonance images (MRIs), and MR angiograms from 1,011 neurologically healthy participants. The presence of silent lacunar infarction (SLI) and moderate-to-severe cerebral white matter hyperintensities (MS-cWMH) were evaluated as indices of cSVD on brain MRIs. Findings of extracranial arterial stenosis (ECAS) or intracranial arterial stenosis (ICAS) were considered to be indices of LCAS on MR angiograms.
Subjects with SLI (odds ratio OR: 2.09; 95% confidence interval CI: 1.27-3.42; p = 0.004) and MS-cWMH (OR: 1.48; 95% CI; 1.03-2.13, p = 0.036) were significantly more likely to have ALP levels in the third tertile (ALP ≥ 195 IU/L) than the first tertile (ALP ≤ 155 IU/L), after adjusting for cardiovascular risk factors. The mean serum ALP level was significantly higher in patients with SLI or MS-cWMH compared to patients without those findings. After adjustment for confounding factors, the multivariate model found that the statistical significance of serum ALP remained when the presence of SLI (OR: 1.05 per 10 IU/L increase in ALP; 95% CI: 1.02-1.08; p = 0.003) or MS-cWMH (OR: 1.03 per 10 IU/L increase in ALP; 95% CI: 1.00-1.06; p = 0.025) were added to the model. There were no differences in the proportions of patients with LCAS, ICAS, and ECAS across the serum ALP tertiles.
Our study of neurologically healthy participants found a positive association between serum ALP level and indicators of cSVD, but no association between serum ALP level and the indicators of LCAS.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Postbiotics, including bacterial lysates, are considered alternatives to probiotics. The aim of the current study was to investigate the effect of bacterial lysates (BLs) extracted from Pediococcus ...acidilactici K10 (K10 BL) and P. acidilactici HW01 (HW01 BL) on the differentiation of 3T3-L1 pre-adipocytes. Both K10 and HW01 BLs significantly reduced the accumulation of lipid droplets and the amounts of cellular glycerides in 3T3-L1 cells (p < 0.05). However, another postbiotic molecule, peptidoglycan of P. acidilactici K10 and P. acidilactici HW01, moderately inhibited the accumulation of lipid droplets, whereas heat-killed P. acidilactici did not effectively inhibit the lipid accumulation. The mRNA and protein levels of the transcription factors, peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α, responsible for the differentiation of 3T3-L1 cells, were significantly inhibited by K10 BL and HW01 BL (p < 0.05). Both K10 and HW01 BLs decreased adipocyte-related molecules, adipocyte fatty acid-binding protein and lipoprotein lipase, at the mRNA and protein levels. Furthermore, both K10 and HW01 BLs also downregulated the mRNA expression of leptin, but not resistin. Taken together, these results suggest that P. acidilactici BLs mediate anti-adipogenic effects by inhibiting adipogenic-related transcription factors and their target molecules.
Graph theory-based reaction pathway searches (ACE-Reaction program) and density functional theory calculations were performed to shed light on the mechanisms for the production of a
+ H
, x
, y
, z
, ...and y
+ 2H
fragments formed in free radical-initiated peptide sequencing (FRIPS) mass spectrometry measurements of a small model system of glycine-glycine-arginine (GGR). In particular, the graph theory-based searches, which are rarely applied to gas-phase reaction studies, allowed us to investigate reaction mechanisms in an exhaustive manner without resorting to chemical intuition. As expected, radical-driven reaction pathways were favorable over charge-driven reaction pathways in terms of kinetics and thermodynamics. Charge- and radical-driven pathways for the formation of y
+ 2H
fragments were carefully compared, and it was revealed that the y
+ 2H
fragments observed in our FRIPS MS spectra originated from the radical-driven pathway, which is in contrast to the general expectation. The acquired understanding of the FRIPS fragmentation mechanism is expected to aid in the interpretation of FRIPS MS spectra. It should be emphasized that graph theory-based searches are powerful and effective methods for studying reaction mechanisms, including gas-phase reactions in mass spectrometry.
A series of four mononuclear water oxidation catalysts (WOCs), denoted as A
2
T
pz
-Ru
II
, in which A
2
represents two axial monodentate ligands, pyridine (Pyr), 4-picoline (4-Pic), isoquinoline ...(Iqn), and
N
-methyl imidazole (Imd), and T
pz
represents a planar tetradentate ligand in the equatorial position (6,6′-di(1
H
-pyrazol-1-yl)-2,2′-bipyridine) were prepared. A series of four photosensitizers (PSs), Ru(bpy)
3
2+
, Ru(bpy)
2
{bpy-(CO
2
Et)
2
}
2+
, Ru(bpy){bpy-(CO
2
Et)
2
}
2
2+
, and Ru{bpy-(CO
2
Et)
2
}
3
2+
, where bpy and bpy-(CO
2
Et)
2
denote 2,2′-bipyridine and diethyl 2,2′-bipyridine-4,4′-dicarboxylate, respectively, denoted as PS-
n
2+
, where
n
= 0, 2, 4, and 6, were prepared. The three known WOCs with the related structures were also prepared. The catalytic performances of the above seven WOCs were evaluated in terms of turnover frequencies (TOFs) and turnover numbers (TONs), while varying PS, and their performances were compared. The measured TOFs were much smaller than those chemically measured. The low concentration of auxiliary oxidant, PS-
n
3+
, arising from low photon flux density of the incident solar simulated light is proposed to be responsible for the large decrease in TOFs. The oxidation power of the oxidized form of PS-
n
2+
(PS-
n
3+
), the oscillator strength (
f
) of PS-
n
2+
and the lifetime of the PS-
n
2+
in the excited state (
τ
ps*
) also sensitively affect the catalytic performance of a WOC. The results were also analyzed by the reaction schemes that were widely used for mononuclear Ru-based WOCs. For this, the corresponding energy-minimized structures, the energy levels of highest occupied molecular orbitals of the initially added WOCs and intermediates, and the free energy change (Δ
G
°) for each reaction step were also derived from DFT calculations. This work introduces a new promising series of WOCs, and gives insights into the directions to increase TONs and TOFs during photochemical evaluations of WOCs.
Four novel and three known mono Ru water oxidation catalysts were prepared and their photocatalytic performances in terms of turnover frequency (TOF) and turnover number (TON) were analyzed, and new directions to increase TOF and TON were presented.
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