872 research outputs found
4-Hydroxy-2,2,6,6-tetramethylpiperidinium perchlorate
In the title salt, C9H20NO+·ClO4
−, intermolecular hydrogen bonds are observed, which determine the crystal packing
Imbalanced Classification in Medical Imaging via Regrouping
We propose performing imbalanced classification by regrouping majority
classes into small classes so that we turn the problem into balanced multiclass
classification. This new idea is dramatically different from popular loss
reweighting and class resampling methods. Our preliminary result on imbalanced
medical image classification shows that this natural idea can substantially
boost the classification performance as measured by average precision
(approximately area-under-the-precision-recall-curve, or AUPRC), which is more
appropriate for evaluating imbalanced classification than other metrics such as
balanced accuracy
Colorectal cancer screening with fecal occult blood test: A 22-year cohort study.
The aim of the present study was to investigate the efficacy of colorectal cancer (CRC) screening with a three-tier fecal occult blood test (FOBT) in the Chinese population. The study was performed between 1987 and 2008 at the Beijing Military General Hospital, in a cohort of army service males and females aged >50 years. Between 1987 and 2005, a three-tier screening program, comprising guaiac-based FOBTs (gFOBTs), followed by immunochemical FOBTs for positive guaiac test samples and then colonoscopy for positive immunochemical test subjects, was performed annually. The cohort was followed up until 2008. The cohort included 5,104 subjects, of which, 3,863 subjects participated in screening (screening group) and 1,241 did not (non-screening group). The two groups did not differ in age, gender or other major risk factors for colon cancer. Overall, 36 CRCs occurred in the screening group and 21 in the non-screening group. Compared with the non-screening group, the relative risk for the incidence and mortality of CRC was 0.51 [95% confidence interval (CI), 0.30-0.87] and 0.36 (95% CI, 0.18-0.71), respectively, in the screening group. The general sensitivity of this three-tier FOBT was 80.6% (95% CI, 65.3-91.1). Thus, annual screening using the three-tier FOBT program may reduce the CRC incidence and mortality rate
[μ-1,4-Bis(1,2,4-triazol-1-ylmethyl)benzene]bis[aqua(pyridine-2,6-dicarboxylato)copper(II)] monohydrate
The title compound, [Cu2(C7H3NO4)2(C12H12N6)(H2O)2]·H2O, displays a discrete dinuclear structure, in which the central CuII atom is five-coordinated in a distorted square-based pyramidal coordination geometry and the flexible ligand 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene adopts a bis-monodentate bridging mode linking the CuII atoms. It is further assembled by O—H⋯O hydrogen-bond interactions involving both the coordinated and uncoordinated water molecules. The latter exhibits half-occupancy
Lesion Topography and Its Correlation With Etiology in Medullary Infarction: Analysis From a Multi-Center Stroke Study in China
Objectives: The lesion topography of medullary infarction (MI) is heterogeneous and its correlation with stroke etiology remains elusive. We aim to clarify the lesion pattern of MI and to assess its correlation with stroke etiology.Material and Methods: Of 1129 subjects with available DWI in SMART study (a multi-center trial concerning secondary stroke prevention in China) between April 2008 and December 2010, 43 patients with DWI confirmed MI (3.8%) were retrospectively evaluated. Lesions were categorized as lateral and medial medullary infarction (LMI and MMI, 33 and 10 subjects respectively) at 3 levels rostro-caudally and correlated with the stroke etiology. Clinical profiles and long-term prognosis were analyzed.Results: Large artery atherosclerosis, small vessel occlusion, cardiogenic embolism and artery dissection accounted for 29, 11, 1, and 2 infarcts, respectively. Large artery disease was the most common cause in LMI (24 of 33, 72.7%) whereas small vessel occlusion was not uncommon in MMI (5 of 10, 50.0%). Though the difference of infarct pattern between large artery atherosclerosis and small vessel occlusion was insignificant, two distinct lesion patterns were considered to be relevant: (1) Rostral MMI with continuous medial pontine infarctions were more likely attributed to small vessel occlusion than large artery atherosclerosis. Kameda et al. (2) MMI with ventral to dorsal extension were more often caused by large artery disease than small vessel occlusion. Median NIHSS at admission was 4. During a median follow-up of 17 months, 2 patients died and 2 experienced recurrent ischemic events, 39 of 41 subjects (95.1%) were functional independent (mRS 0–2).Conclusions: This multi-center study demonstrates that MI has distinct lesion pattern depending on various stroke etiologies and mechanisms. Future investigations with larger sample size should establish the lesion pattern of MI and validate its correlation with the stroke etiology and mechanisms, which might improve stroke management
Penetration and pharmacokinetics of ferulic acid after dermal administration
Purpose: To study the in vitro penetration and in vivo pharmacokinetics of ferulic acid (FA), and the correlation between them after dermal administration.
Methods: Franz diffusion cell was used to study in vitro penetration of FA. The concentration of FA in the Franz receiver solution was assessed by high performance liquid chromatography (HPLC). Prior to in vivo pharmacokinetics experiments, probe recovery was validated with respect to influencing factors such as flow rate, FA concentration, within-day stability and reproducibility of the probes. In in vivo pharmacokinetic experiment, six male CD-1 hairless mice were used. The micro-dialysis (MD) probe was implanted in the dermis of the rat skin, and dialysates from probe outlet were quantified directly by HPLC. In in vivo studies, deconvolution methods were used to determine the relationship between in vitro and in vivo data, and the correlation coefficient of linear equations.
Results: There was significant effect of pH (5 ~ 8) on the penetration of FA. Increase in pH caused commensurate decrease in permeability. The Cmax of FA was 300.74 ± 31.86 ng/mL while Tmax was 138.00 ± 22.80 min after dermal administration of 1 mg/mL FA dissolved in phosphate buffered saline (PBS). The correlation coefficient (r) between in vitro and in vivo data was 0.9905.
Conclusion: Both in vivo and in vitro experiments demonstrate that FA permeates the stratum corneum of skin rapidly. The unionized form of FA shows better penetration than the ionic form. In addition, results from correlation analysis indicate that the in vitro penetration characteristics of FA can be applied to predict its in vivo pharmacokinetics
The Role of Reactive Iron in the Preservation of Terrestrial Organic Carbon in Estuarine Sediments
To better understand the role of reactive Fe (FeR) in the preservation of sedimentary OC (SOC) in estuarine sediments, we examined specific surface area (SSA), grain size composition, total OC (TOC), lignin phenols, FeR, FeR-associated OC (Fe-OC) and lignin phenols (Fe-lignin), and δ13C of FeR-associated OC (δ13 CFe-OC) in surface sediments of the Changjiang Estuary and adjacent shelf. An estimated 7.4 ± 3.5% of the OC was directly bound with FeR in the Changjiang Estuary and adjacent shelf. Unusually low TOC/SSA loadings and Fe-OC/Fe ratios in mobile-muds suggest that frequent physical reworking may reduce FeR binding with OC, with selective loss of marine OC. More depleted 13CFe-OC relative to 13C of TOC (13 Cbulk) in deltaic regions and mobile-muds showed that FeR was largely associated with terrestrial OC, derived from extensive riverine C and Fe inputs. A higher proportion of hematite in the mobile muds compared to the offshore samples indicated that Fe oxides are likely subjected to selective sorting and/or become mature during long-term sediment transport. When considering the percentage of Fe-OC to SOC and SOC burial rates in different marine environments (e.g., non deltaic shelf, anoxic basins, slope and deep sea), our findings suggest that about 15.6 ± 6.5% of SOC is directly bound to FeR on a global scale, which is lower than the previous estimation (~21.5%). This work further supports the notion of a “Rusty Sink” where, in this case FeR plays an important role in the preservation and potential transport of terrestrial OC in the marine environment
- …