Resistance on the Internet: A study of the Singapore Case

Master'sMASTER OF SOCIAL SCIENCE

Research on Multipath Correlated Imaging with the Grayscale Target in Endoscopic Applications

The application of correlated imaging in endoscope, one of the research hotspots, may lead to multipath effect in the closed endoscopic environment. The model of multipath correlated imaging with a grayscale object is given, where the mismatch ratio and the reflection ratio are two key factors affecting imaging quality. The theoretical and experimental results show that multipath effect has an influence on the grayscale distribution and imaging quality of the reconstructed image, and the effect of the mismatch ratio is stronger than that of the reflection ratio. The conditions that the disturbance from multipath effect can be ignored in endoscopic applications are given

Development of a specific monoclonal antibody-based ELISA to measure the artemether content of antimalarial drugs.

Artemether is one of the artemisinin derivatives that are active ingredients in antimalarial drugs. Counterfeit and substandard antimalarial drugs have become a serious problem, which demands reliable analytical tools and implementation of strict regulation of drug quality. Structural similarity among artemisinin analogs is a challenge to develop immunoassays that are specific to artemisinin derivatives. To produce specific antibodies to artemether, we used microbial fermentation of artemether to obtain 9-hydroxyartemether, which was subsequently used to prepare a 9-O-succinylartemether hapten for conjugation with ovalbumin as the immunogen. A monoclonal antibody (mAb), designated as 2G12E1, was produced with high specificity to artemether. 2G12E1 showed low cross reactivities to dihydroartemisinin, artemisinin, artesunate and other major antimalarial drugs. An indirect competitive enzyme linked immunosorbent assay (icELISA) developed showed a concentration causing 50% of inhibition for artemether as 3.7 ng mL⁻¹ and a working range of 0.7-19 ng mL⁻¹. The icELISA was applied for determination of artemether content in different commercial drugs and the results were comparable to those determined by high-performance liquid chromatography analysis. In comparison with reported broad cross activity of anti-artemisinin mAbs, the most notable advantage of the 2G12E1-based ELISA is its high specificity to artemether only

Data_Sheet_1_Eimeria infections of plateau pika altered the patterns of temporal alterations in gut bacterial communities.pdf

Intestinal parasites, such as Eimeria, are common among plateau pika (Ochotona curzoniae). The gut microbiome is an essential driver of the host response to gastrointestinal parasites. However, the effects of intestinal protozoal parasites on the temporal variations in the gut microbiome and behavioral and physiological activities remain unknown. Our study conducted treatments involving experimental feeding of pika with Eimeria oocysts or anticoccidia under laboratory conditions to focus on the parasite-associated alterations in gut bacterial communities, host behavioral activity, physiology, and host–bacteria relationships. The results showed insignificant differences in bacterial community structures among treatments on the basis of Bray–Curtis distance metrics, whereas the patterns of temporal alterations in the bacterial communities were changed by the treatments. Bacterial alpha diversities did not vary with the treatments, and experimental feeding with Eimeria slowed down the decrement rate of alpha diversity. Furthermore, few bacterial members were significantly changed by the treatments—only the genus Ruminococcus and the species Ruminococcus flavefaciens, which were associated with energy metabolism. Experimental feeding with Eimeria modified the temporal variations in the bacterial members, including a lower loss rate of the relative abundance of the dominant families Muribaculaceae and Ruminococcaceae in the group with Eimeria experimental feeding. Moreover, a shifting energy trade-off was suggested by the parasite-induced increments in thyroid hormones (triiodothyronine and tetraiodothyronine) and decrements in exploration behavior in the group with Eimeria feeding. However, we did not detect specific connections between gut bacterial communities and pika behaviors and physiology in terms of energy trade-offs. Further in-depth research is needed to examine the role of Eimeria-modified differences in the gut bacteria of plateau pika.</p

Comparison of the icELISA and HPLC method for quantitation of artemether in commercial drugs.

a<p>Each sample was analyzed in triplicate.</p>b<p>Data represent mean ± SD. The unit for ELISA and HPLC data was mg mL⁻¹. The theoretical content of all drugs was 2 mg mL⁻¹.</p

Standard inhibition curve of artemether in icELISA format.

<p>B₀ and B are absorbance in the absence and presence of competitors, respectively. Concentration causing 50% inhibition by artemether was 3.70 ng mL⁻¹. Each value represents the mean of three replicates.</p

Microbial transformation of artemether.

<p>Microbial transformation of artemether.</p

Cross reactivities of the icELISA with commonly used antimalarial drugs.

a<p>Cross-reactivity (%) = (IC₅₀ of artemether/IC₅₀ of other compound)×100.</p>b<p>Data represent means of triplicate ± SD.</p>c<p>No inhibitions were observed up to 20,000 ng mL⁻¹ of the analytes.</p