Highly sensitive electrochemical sensing platform for the detection of L-dopa based on electropolymerizing glutathione disulfide and multi-walled carbon nanotube-modified electrodes

Afacile sensing platformfor the detection of L-dopa has been developed by electropolymerizing glutathione disulfide (PGSSG) on the surface of glass carbon electrodes (GCE) which were modified by multi-walled carbon nanotubes (MWCNTs). The electrochemical behaviour of the proposed electrodes were investigated via cyclic voltammetry (CV) and differential pulse voltammetry DPV). The morphology of the PGSSG and PGSSG/MWCNTs were characterized by scanning electron microscopy (SEM). Under the optimized experimental conditions, the sensing platform showed the linear response to L-Dopa in a range from 1.0 × 10–6 to 1.2 × 10–3 M with a detection limit of 3.3 × 10–7M (S/N = 3). Moreover, with the merits of high sensitivity and selectivity, good stability and reproducibility, the sensor was successfully applied for the determination of L-dopa in a real sample.Keywords: L-dopa, glutathione disulfide, multi-walled carbon nanotubes, electropolymerization, electrochemical determinatio

An investigation of the influence of the morphological indexes of trees on the outdoor microclimate at high altitude in summer

Trees have significant effects of shading, humidifying, and cooling, and at the same time, they can create a more comfortable space for people. However, due to the complexity of their own biology, there are also some differences in the regulation mechanism of the space microclimate among different trees. Under the background of a high altitude and cold climate, based on field measurements and numerical simulation, this paper discussed the effects of the morphological indexes, including the height, crown width, leaf area index (LAI), and under branch height of trees and their interactions on the urban microclimate and thermal comfort in Lhasa city, which belongs to the Warm Summer Winter Dry Cold Climate (Dwb). The study revealed the following: 1) LAI is the key factor affecting the thermal environment and thermal comfort of the space under a tree, followed by height and crown width, and the improvement potential of under branch height is relatively weak. 2) The interaction between height and LAI and crown width affects the thermal comfort of the space under a tree. 3) In summer, the optimal combination of tree morphological indexes in Lhasa is LAI = 2, height = 12 m, crown width = 11 m, ground reflectance = 0.2

Clinicopathological Significance and Prognostic Value of DNA Methyltransferase 1, 3a, and 3b Expressions in Sporadic Epithelial Ovarian Cancer

Altered DNA methylation of tumor suppressor gene promoters plays a role in human carcinogenesis and DNA methyltransferases (DNMTs) are responsible for it. This study aimed to determine aberrant expression of DNMT1, DNMT3a, and DNMT3b in benign and malignant ovarian tumor tissues for their association with clinicopathological significance and prognostic value. A total of 142 ovarian cancers and 44 benign ovarian tumors were recruited for immunohistochemical analysis of their expression. The data showed that expression of DNMT1, DNMT3a, and DNMT3b was observed in 76 (53.5%), 92 (64.8%) and 79 (55.6%) of 142 cases of ovarian cancer tissues, respectively. Of the serious tumors, DNMT3a protein expression was significantly higher than that in benign tumor samples (P = 0.001); DNMT3b was marginally significant down regulated in ovarian cancers compared to that of the benign tumors (P = 0.054); DNMT1 expression has no statistical difference between ovarian cancers and benign tumor tissues (P = 0.837). Of the mucious tumors, the expression of DNMT3a, DNMT3b, and DNMT1 was not different between malignant and benign tumors. Moreover, DNMT1 expression was associated with DNMT3b expression (P = 0.020, r = 0.195). DNMT1 expression was associated with age of the patients, menopause status, and tumor localization, while DNMT3a expression was associated with histological types and serum CA125 levels and DNMT3b expression was associated with lymph node metastasis. In addition, patients with DNMT1 or DNMT3b expression had a trend of better survival than those with negative expression. Co-expression of DNMT1 and DNMT3b was significantly associated with better overall survival (P = 0.014). The data from this study provided the first evidence for differential expression of DNMTs proteins in ovarian cancer tissues and their associations with clinicopathological and survival data in sporadic ovarian cancer patients

Luminal-Applied Flagellin Is Internalized by Polarized Intestinal Epithelial Cells and Elicits Immune Responses via the TLR5 Dependent Mechanism

Bacteria release flagellin that elicits innate responses via Toll-like receptor 5 (TLR5). Here, we investigated the fate of apically administrated full length flagellin from virulent and avirulent bacteria, along with truncated recombinant flagellin proteins in intestinal epithelial cells and cellular responses. Flagellin was internalized by intestinal epithelial cell (IEC) monolayers of IEC-18. Additionally, apically applied flagellin was internalized by polarized human Caco-2BBe and T-84 cells in a TLR5 dependent mechanism. More, flagellin exposure did not affect the integrity of intestinal monolayers. With immunofluorescent staining, internalized flagellin was detected in both early endosomes as well as lysosomes. We found that apical exposure of polarized Caco-2BBe and T-84 to flagellin from purified Salmonella, Escherichia coli O83:H1 (isolate from Crohn’s lesion) or avirulent E. coli K12 induced comparable levels of basolateral IL-8 secretion. A recombinant protein representing the conserved amino (N) and carboxyl (C) domains (D) of the flagellin protein (ND1/2ECHCD2/1) induced IL-8 secretion from IEC similar to levels elicited by full-length flagellins. However, a recombinant flagellin protein containing only the D3 hypervariable region elicited no IL-8 secretion in both cell lines compared to un-stimulated controls. Silencing or blocking TLR5 in Caco-2BBe cells resulted in a lack of flagellin internalization and decreased IL-8 secretion. Furthermore, apical exposure to flagellin stimulated transepithelial migration of neutrophils and dendritic cells. The novel findings in this study show that luminal-applied flagellin is internalized by normal IEC via TLR5 and co-localizes to endosomal and lysosomal compartments where it is likely degraded as flagellin was not detected on the basolateral side of IEC cultures

LITTLE INDIA SOCIAL CONDENSER: A FOREIGN WORKERS' RECREATION CENTRE

Master'sMASTER OF ARCHITECTURE (M.ARCH

Measuring the benefits of the development strategy of the “21st century maritime silk road” via an intervention analysis approach: Evidence from China and neighbouring countries in Southeast Asia

The present study adopts a new political intervention analysis approach to evaluate the impact of the “21st Century Maritime Silk Road” (MSR) policy. The basic concept is to investigate dependence amongst cross-sectional units to construct counterfactuals without intervention. Thus, the effect of policy intervention is simply the difference between the outcomes with and without intervention. The panel data of 14 countries along MSR are used to illustrate the methodology. Real data analysis shows that the MSR policy exerts a positive effect on the trade of China and Southeast Asian countries. Furthermore, policy implications are provided based on the analysis

Pediatric suppurative parotitis caused by Burkholderia pseudomallei

Abstract Background: Suppurative parotitis caused by Burkholderia pseudomallei has been rarely found outside endemic areas. Case presentation: Herein, we report the recovery of Burkholderia pseudomallei from the pus of a suppurative parotitis observed in a 12-year-old boy who lived in Hainan province, China. Specimens of necrotic tissue were collected and sections were stained with hematoxylin and eosin. Pus sample was also collected for bacteriological examination. The suppurative inflammation was observed in the necrotic tissue section and Burkholderia pseudomallei were detected in the sample. Conclusion: In this adolescent, Burkholderia pseudomallei infection was present in the parotid, which consists of the first report of this bacterium in a parotitis case acquired in China