Numerical modelling of acoustic stimulation induced mechanical vibration enhancing coal permeability

Mechanical vibration is a major effect generated by acoustic stimulation inside a coal sample for enhancing its permeability. The numerical simulation based on the staggered-grid finite differential method (FDM) is applied to simulate 3D wave propagation in a fractured coal. Two parameters, shear wave energy (SE) and variable width of cleat (DW), are introduced and implemented in the numerical model to explicitly visualise and evaluate the acoustic stimulation effects. The polarized wave induced wave dynamics in a coal sample with a cleat/fracture is numerically simulated and analysed. Especially, the energy trapping and dynamic variation of fracture width in coal for the cleat/fracture with three different filled media (i.e. air, water and weak mineral) are numerically analysed and compared with each other subjected to different incident wave angles, and the optimal stimulation parameters are obtained through such sensitivity analysis. Simulation results show that the coal property (i.e. cleat and its filled media) and incident wave angles are crucial for acoustic stimulation to produce physical damages around coal cleats and enhance the permeability of fractured coal samples

Hiding inside? Intracellular expression of non-glycosylated c-kit protein in cardiac progenitor cells

Cardiac progenitor cells including c-kit(+) cells and cardiosphere-derived cells (CDCs) play important roles in cardiac repair and regeneration. CDCs were reported to contain only small subpopulations of c-kit(+) cells and recent publications suggested that depletion of the c-kit(+) subpopulation of cells has no effect on regenerative properties of CDCs. However, our current study showed that the vast majority of CDCs from murine heart actually express c-kit, albeit, in an intracellular and non-glycosylated form. Immunostaining and flow cytometry showed that the fluorescent signal indicative of c-kit immunostaining significantly increased when cell membranes were permeabilized. Western blots further demonstrated that glycosylation of c-kit was increased during endothelial differentiation in a time dependent manner. Glycosylation inhibition by 1-deoxymannojirimycin hydrochloride (1-DMM) blocked c-kit glycosylation and reduced expression of endothelial cell markers such as Flk-1 and CD31 during differentiation. Pretreatment of these cells with a c-kit kinase inhibitor (imatinib mesylate) also attenuated Flk-1 and CD31 expression. These results suggest that c-kit glycosylation and its kinase activity are likely needed for these cells to differentiate into an endothelial lineage. In vivo, we found that intracellular c-kit expressing cells are located in the wall of cardiac blood vessels in mice subjected to myocardial infarction. In summary, our work demonstrated for the first time that c-kit is not only expressed in CDCs but may also directly participate in CDC differentiation into an endothelial lineage

Development of a new stroke scale in an emergency setting

Background: Early identification of stroke is crucial to maximize early management benefits in emergency departments. This study aimed to develop and validate a new stroke recognition instrument for differentiating acute stroke from stroke mimics in an emergency setting. Methods: A prospective observational cohort study among suspected stroke patients presenting to Emergency Department in the Second Affiliated Hospital of Guangzhou Medical University was conducted from May 2012 to March 2013. The symptoms and signs of suspected stroke patients were collected. Logistic regression analysis was used to identify the factors associated with acute stroke. The symptoms and signs closely associated with acute stroke were selected to develop the new stroke scale, Guangzhou Stroke Scale (GZSS). The diagnostic value of GZSS was then compared with ROSIER, FAST and LAPSS. The primary outcome was confirmed stroke by CT within 24 h. Results: Four hundred and sixteen suspected stroke patients (247 ischemia, 107 hemorrhage, 4 transient ischemic attack, 58 non-stroke) were assessed. A new stroke scale, GZSS (total score from −1 to 8.5), was developed and consisted of nine parameters: vertigo (−1), GCS ≤ 8 (+2), facial paralysis (+1), asymmetric arm weakness (+1), asymmetric leg weakness (+1), speech disturbance (+0.5), visual field defect (+1), systolic blood pressure ≥145 mmHg (+1) and diastolic blood pressure ≥95 mmHg (+1). Among the four scales, the discriminatory value (C-statistic) of GZSS was the best (AUC: 0.871 (p < 0.001) when compared to ROSIER (0.772), LAPSS (0.722) and FAST (0.699). At an optimal cut-off score of >1.5 on a scale from −1 to 8.5, the sensitivity and specificity of GZSS were 83.2 and 74.1 %, whilst the sensitivities and specificities of ROSIER were 77.7 and 70.7 %, FAST were 76.0 and 63.8 %, LAPSS were 56.4 and 87.9 %. Conclusion: GZSS had better sensitivity than existing stroke scales in Chinese patients with suspected stroke. Further studies should be conducted to confirm its effectiveness in the initial differentiation of acute stroke from stroke mimics. Keywords: Diagnosis, Stroke, Stroke mimics, ROSIER scale, FAST scale, LAPSS scale, Emergency department, China Abbreviations: AUC, area under the ROC curve; CT, computed tomography; DWI, diffusion weighted imaging; FAST, the face arm speech test; GCS, Glasgow Coma Scale; IQR, inter quartile range; LAPSS, the Los Angeles Prehospital Stroke Screen; MRI, magnetic resonance imaging; NIHSS, National Institute of Health stroke scale; OR, odds ratio; ROC, receiver operating characteristic; ROSIER, the Recognition of Stroke in the Emergency Room scale; TIA, transient ischemic attac

A STUDY ON SCREENING OF OSTEOSARCOMA U2OS CELL INHIBITING ACTIVE COMPONENTS FROM NIDUS VESPAE

This paper mainly examined the anti-osteosarcoma activity of total flavonoids extract from traditional Chinese medicine, nidus vespae. Orthogonal design was used to design the extraction process of total flavonoids. L(34) orthogonal test was performed and the extracts obtained by three optimal extraction processes were used for anti-tumour activity screening in order to determine the optimal anti-tumour effective component of nidus vespae. MTT assay was used to investigate the effect of nidus vespae extract on proliferation activity of osteosarcoma cells. Meanwhile, U2OS cell inhibitory capacities of extracts in three groups with higher total flavonoid contents were investigated and compared, and inhibition rates were calculated. The results showed that the optimal extraction process was ethanol concentration of 95%, 12-fold amount of ethanol relative to the weight of medicinal material, extraction times of 3 times, and extraction time of 2 hours. 9 extraction processes all showed proportional trend of cancer cell inhibition rate to extract concentration

STEMI outcomes in Guangzhou and Hong Kong: two-centre retrospective interregional study

BACKGROUND AND OBJECTIVES:Healthcare systems are organized very differently in Hong Kong (HK) and Guangzhou (GZ). This study compared managements of the emergency departments (ED) and one-year mortalities of ST-segment elevation myocardial infarction (STEMI) patients in two teaching hospitals in Guangzhou and Hong Kong. METHODS:Retrospective observational study of STEMI mortalities and treatments in the Prince of Wales Hospital (PWH) and the Second Affiliated Hospital of Guangzhou Medical University (AHGZMU), was conducted between January and December 2010. The primary outcome was one-year all cause mortality. RESULTS:Univariate analysis of 76 cases from PWH and 111 cases from AHGZMU showed similar clinical characteristics, except for lower proportions of males (74% vs 92%, P = 0.002), hyperlipidemia (5% vs 25%, P67 years) and hyperglycemia (>10 mmol/L). Aged over 65 years, presence of anterior wall infarct, body weight ≤65 kg, SBP 10 mmol/L were the independent predictors of in-hospital MACE. CONCLUSION:There was no statistically significant difference between the standardized one-year all-cause mortalities of STEMI patients in the setting mainly using thrombolysis with shorter door-to-treatment time and the setting mainly using PCI with longer door-to-treatment time. Aged over 67 years and glucose level over 10 mmol/L were the independent predictors of one-year mortality. Older age, presence of anterior wall infarct, lower body weight, lower SBP at ED and hyperglycemia were the independent predictors of in-hospital MACE

Associations between colorectal cancer risk and dietary intake of tomato, tomato products, and lycopene: evidence from a prospective study of 101,680 US adults

BackgroundPrevious epidemiological studies have yielded inconsistent results regarding the effects of dietary tomato, tomato products, and lycopene on the incidence of colorectal cancer (CRC), possibly due to variations in sample sizes and study designs.MethodsThe current study used multivariable Cox regression, subgroup analyses, and restricted cubic spline functions to investigate correlations between CRC incidence and mortality and raw tomato, tomato salsa, tomato juice, tomato catsup, and lycopene intake, as well as effect modifiers and nonlinear dose-response relationships in 101,680 US adults from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.ResultsDuring follow-up 1100 CRC cases and 443 CRC-specific deaths occurred. After adjustment for confounding variables, high consumption of tomato salsa was significantly associated with a reduced risk of CRC incidence (hazard ratio comparing the highest category with the lowest category 0.8, 95% confidence interval 0.65–0.99, p for trend = 0.039), but not with a reduced risk of CRC mortality. Raw tomatoes, tomato juice, tomato catsup, and lycopene consumption were not significantly associated with CRC incidence or CRC mortality. No potential effect modifiers or nonlinear associations were detected, indicating the robustness of the results.ConclusionIn the general US population a higher intake of tomato salsa is associated with a lower CRC incidence, suggesting that tomato salsa consumption has beneficial effects in terms of cancer prevention, but caution is warranted when interpreting these findings. Further prospective studies are needed to evaluate its potential effects in other populations

Serum osteocalcin and urinary free deoxypyridinoline as potential risk factors in predicting the prevalence of bone trauma among the post-menopausal Chinese women

This study was designed to understand whether the post-menopausal Chinese women (n=175) receiving tablet containing vitamin D (500 IU) and calcium (500 mg) had lower incidence of bone fracture compared to the post-menopausal Chinese women ((n=175) receiving a diet rich in calcium, vitamin D, and protein  (milk, cheese, and yogurt, soybeans, spinach, fish including fatty fish, cheese, egg). This study assessed whether the levels of serum osteocalcin and urinary free deoxypyridinoline could be used as predictors of early bone trauma during post-menopausal period. After randomization, subjects were followed-up for up to 3 years to capture required data. The results suggested that therapeutic intervention (vitamin D and calcium) does not predict bone fracture among the post-menopausal Chinese women. However, correlation analysis revealed that the decreased level of serum osteocalcin and urinary free deoxypyridinoline were associated with higher incidence of fracture. The results suggest that the low level of serum osteocalcin and urinary free deoxypyridinoline cause increase susceptibility of fracture among the post-menopausal Chinese women

Comparison of outcomes in emergency department patients with suspected cardiac chest pain: two-centre prospective observational study in Southern China

Background Hong Kong (HK) and Guangzhou (GZ) are cities in China with different healthcare systems. This study aimed to compare 30-day and 6-month mortality and characteristics of patients with suspected cardiac chest pain admitted to two emergency departments (ED) in HK and GZ. Methods A prospective observational study enrolled patients with suspected cardiac chest pain presenting to EDs in the Prince of Wales Hospital (PWH), HK and the Second Affiliated Hospital of Guangzhou Medical University (AHGZMU),GZ. The primary outcome was 30-day and 6-month mortality. Results In total, 996 patients were recruited, 407 cases from GZ and 589 cases from HK.The 30-day and 6-month mortality of chest patients were 3.7% and 4.7% in GZand 0.3% and 1.9% in HK, respectively. Serum creatinine level (Cr) was an independent factor for 30-day mortality whilst Cr and systolic blood pressure (SBP) were independent factors for 6-month mortality. In Cox regression analysis, unadjusted and adjusted hazard ratios for 30-day and 6-month mortality in GZ were significantly increased. Conclusion The 30-day and 6-month mortality of patients with suspected cardiac chest pain in Guangzhou were higher than in Hong Kong due to due to different baseline clinical characteristics of patients and different distributions of diagnoses, which were associated with different healthcare systems. Serum creatinine and SBP were independent factors for 30-day and 6-month mortality