MyMedR

Displaying all 9 publications

Abstract:

Sort:

The application of fractal dimension on capillary pressure curve to evaluate the tight sandstone

Chunhua Guo, Ping Yan, Ruili Zhou, Xiaodong Peng, Yu Yang

Sains Malaysiana, 2017;46:2149-2162.

The rock of gas tight reservoir is more heterogeneous than that of conventional sandstone reservoir and is more prone to water-blockage because of the invasion of operation fluid. This paper presented a new approach for the analysis of the capillary pressure curve for tight gas reservoir. Herein, the saturation equation with fractal dimension proved the previous observation that the log-log plot of capillary pressure against water saturation is a straight line, which is quite different from the popular observation by Corey’s correlation. How to transform the capillary pressure curve to relative permeability curve was also discussed with fractal dimension. The fractal dimension of capillary pressure, which is not only an indication of heterogeneity, can also reveal the potential water blocks in tight gas wells. If the rock has higher fractal dimension, being at the same water saturation, the capillary pressure will be higher and the relative permeability of water will be smaller, which means higher injection pressure is required to displace the trapped water in reservoir. It is suggested that for the tight gas pay zone with higher fractal dimension, more precautions should be taken to prevent the water trapping during drilling or stimulating operation.
Fulltext Main drivers of regional value chains in CAFTA: Does trade facilitation matter?

Yu Y, Song Z

PLoS One, 2023;18(12):e0289775.
PMID: 38060468 DOI: 10.1371/journal.pone.0289775

In the last decades, economic globalisation and the progress of ICT have promoted the international division of labour and optimisation of the global value chain. Moreover, improvements in incentives such as lower tariffs and more efficient border crossings have boosted international trade. Under this background, regional and sub-regional economic cooperation organizations, such as free trade area (FTA), have been developing rapidly and attracting many academic attentions. As the fastest growing FTA in the world, CAFTA is now the largest FTA in developing countries. This study focuses on the value-added network of various industries in the trade process inside CAFTA, and tries to explore the impact of trade facilitation on the DVA trade network of CAFTA. The results show that in the trade network of CAFTA, the proportion of added value of domestic trade in total exports keeps increasing, and the returned added value (RDV) increases significantly. Singapore, Vietnam, and Thailand hold relatively high positions in the production network, while China has a relatively low position. On the other hand, China and Thailand become the main beneficiaries after the establishment of CAFTA, while Singapore and Malaysia play a lesser role in trading networks. The results also show that trade facilitation has a significant positive effect on the DVA-INTrex and RDV trade networks, indicating that trade facilitation can significantly increase the domestic indirect value added and returned value added in the trade process. Moreover, the business environment (bus) is the most important factor, with efficiency and transparency of border administration (cus), availability, and use of ICTs (ict) contributing to the improvement.
Post mastectomy radiotherapy for elderly patients with intermediate risk (T1-2N1 OR T3N0) breast cancer: a systematic review and meta-analysis

Tseng M, Vellayappan B, Choong R, Appalanaido GK, Soon YY

Transl Cancer Res, 2020 Jan;9(Suppl 1):S23-S28.
PMID: 35117945 DOI: 10.21037/tcr.2019.07.23

Background: To determine if PMRT for elderly patients (>65 years old) with intermediate risk breast cancer (T1-2N1, T3N0) improves outcomes.
Methods: We performed a systematic review and meta-analysis to compare the effects of PMRT to no PMRT for elderly patients with intermediate-risk breast cancer. We searched PubMed for eligible studies from Jan 2008 to Dec 2018. We assessed the methodological quality of the included studies using the ROBINS-I tool and performed the meta-analysis with random effects model. The primary outcome of interest was overall survival (OS); secondary outcomes were breast cancer specific survival (BCSS), loco-regional (LRR) and distant disease recurrence (DDR).
Results: We found 2 retrospective cohort studies with 743 patients directly comparing PMRT to no PMRT. Both studies were judged to have serious risk of bias in their methodological quality. The pooled results suggest that PMRT was associated with a 20% relative reduction in the hazard in death, ranging from 41% relative reduction, a substantial negative association to 10% relative increase, a small positive association (HR 0.80, 95% CI: 0.59-1.1, P=0.62, I2=0%). PMRT was also associated with a 17% relative reduction in the hazard for breast cancer related death, ranging from 52% relative reduction, a substantial negative association to 41% relative increase, a substantial positive association (HR 0.83, 95% CI: 0.48-1.41, P=0.48, I2=0%). One study did not observe any significant differences in LRR and DDR between the two groups.
Conclusions: The survival benefits from PMRT in unselected elderly patients with intermediate risk breast cancer is unclear. Further research to better select elderly patients who may benefit from PMRT is warranted. Patients with a multiple pathological risk factors suggestive of high risk of loco-regional recurrence post-mastectomy should consider PMRT.
Fulltext Development and Evaluation of Topical Zinc Oxide Nanogels Formulation Using Dendrobium anosmum and Its Effect on Acne Vulgaris

Tan YY, Wong LS, Nyam KL, Wittayanarakul K, Zawawi NA, Rajendran K, et al.

Molecules, 2023 Sep 22;28(19).
PMID: 37836592 DOI: 10.3390/molecules28196749

Zinc oxide nanoparticles have high levels of biocompatibility, a low impact on environmental contamination, and suitable to be used as an ingredient for environmentally friendly skincare products. In this study, biogenically synthesized zinc oxide nanoparticles using Dendrobium anosum are used as a reducing and capping agent for topical anti-acne nanogels, and the antimicrobial effect of the nanogel is assessed on Cutibacterium acne and Staphylococcus aureus. Dendrobium anosmum leaf extract was examined for the presence of secondary metabolites and its total amount of phenolic and flavonoid content was determined. Both the biogenically and chemogenic-synthesized zinc oxide nanoparticles were compared using UV-Visible spectrophotometer, FE-SEM, XRD, and FTIR. To produce the topical nanogel, the biogenic and chemogenic zinc oxide nanoparticles were mixed with a carbomer and hydroxypropyl-methyl cellulose (HPMC) polymer. The mixtures were then tested for physical and chemical characteristics. To assess their anti-acne effectiveness, the mixtures were tested against C. acne and S. aureus. The biogenic zinc oxide nanoparticles have particle sizes of 20 nm and a high-phase purity. In comparison to chemogenic nanoparticles, the hydrogels with biogenically synthesized nanoparticles was more effective against Gram-positive bacteria. Through this study, the hybrid nanogels was proven to be effective against the microbes that cause acne and to be potentially used as a green product against skin infections.
Limonoids and triterpenoid from fruit of Swietenia macrophylla

Sun YP, Zhu LL, Liu JS, Yu Y, Zhou ZY, Wang G, et al.

Fitoterapia, 2018 Mar;125:141-146.
PMID: 29325928 DOI: 10.1016/j.fitote.2018.01.004

Five new limonoids, swieteliacates A-E (1-5) and a tirucallane-type triterpenoid, swietesenin (6), together with four known compounds (7-10) were isolated from fruit of Swietenia macrophylla. Their structures were determined by spectroscopic analyses. The new compounds were tested in vitro for their cytotoxic effects against five human cancer cell lines. Compound 2 exhibited moderate cytotoxic activities against SW480 and HL-60 cancer cell lines with IC50 values of 30.6 and 32.9μM, respectively.
Fulltext Organic Bulk-Heterojunction Blends with Vertical Phase Separation for Enhanced Organic Photodetector Performance

Chen CP, Peng YC, Jiang BH, Hsu MW, Chan CK, Du HY, et al.

Polymers (Basel), 2024 Oct 29;16(21).
PMID: 39518249 DOI: 10.3390/polym16213040

The ternary blending strategy is a fundamental approach that is widely recognized in the field of organic optoelectronics. In our investigation, leveraging the inherent advantages of the ternary component blending methodology, we introduced an innovative design for organic photodetectors (OPDs) aimed at reducing the dark current density (Jd) under reverse bias. This pioneering effort involved combining two distinct conjugated molecules (IT-4F and IEICO-4F) with a conjugated polymer (PM7), resulting in a composite material characterized by a well-defined vertical phase separation. To thoroughly explore device performance variations, we utilized a comprehensive array of analytical techniques, including atomic force microscopy (AFM) cross-section methodologies and Kelvin probe force microscopy (KPFM). Through the optimization of the blend ratio (PM7:IT-4F: IEICO-4F at 1:0.8:0.2), we achieved significant advancements. The resulting OPD demonstrated an exceptional reduction in JD, reaching a remarkably low value of 4.95 × 10-10 A cm-2, coupled with an ultra-high detectivity of 4.95 × 1013 Jones and an outstanding linear dynamic range exceeding 100 dB at 780 nm under a bias of -1V. Furthermore, the attained cutoff frequency reached an impressive 220 kHz, highlighting substantial improvements in device performance metrics. Of particular significance is the successful translation of this technological breakthrough into real-world applications, such as in heart rate sensing, underscoring its tangible utility and expanding its potential across various fields. This demonstrates its practical relevance and underscores its versatility in diverse settings.
Realizing room temperature catalytic hydrogenation of sodium phenoxide by Ru/TiO2 for hydrogen storage

Tan KC, Pei Q, Yu J, Wen H, Yu Y, Wang J, et al.

Chem Commun (Camb), 2023 Apr 04;59(28):4177-4180.
PMID: 36942825 DOI: 10.1039/d3cc00068k

Sodium phenoxide is a potentially promising hydrogen storage material due to its high hydrogen capacity and enhanced thermodynamic properties. Nevertheless, efficient catalysts are still lacking due to the high kinetic barrier for the reversible hydrogen uptake and release of sodium phenoxide. In the current work, a comparative study on the catalytic hydrogenation of sodium phenoxide was conducted. To our delight, a simple yet effective ruthenium-based catalyst was identified to respond aggressively to hydrogen in the solid-state hydrogenation of sodium phenoxide even at room temperature. The activity was enhanced by 6 fold with the as-synthesized 5.0% Ru/TiO2 catalyst as compared to that with commercial 5.0% Ru/Al2O3, respectively, under the same conditions.
Children's exposure to food advertising on free-to-air television: an Asia-Pacific perspective

Kelly B, Hebden L, King L, Xiao Y, Yu Y, He G, et al.

Health Promot Int, 2016 Mar;31(1):144-52.
PMID: 24997194 DOI: 10.1093/heapro/dau055

There is an established link between food promotions and children's food purchase and consumption. Children in developing countries may be more vulnerable to food promotions given the relative novelty of advertising in these markets. This study aimed to determine the scope of television food advertising to children across the Asia-Pacific to inform policies to restrict this marketing. Six sites were sampled, including from China, Indonesia, Malaysia and South Korea. At each site, 192 h of television were recorded (4 days, 16 h/day, three channels) from May to October 2012. Advertised foods were categorized as core/healthy, non-core/unhealthy or miscellaneous, and by product type. Twenty-seven percent of advertisements were for food/beverages, and the most frequently advertised product was sugar-sweetened drinks. Rates of non-core food advertising were highest during viewing times most popular with children, when between 3 (South Korea) and 15 (Indonesia) non-core food advertisements were broadcast each hour. Children in the Asia-Pacific are exposed to high volumes of unhealthy food/beverage television advertising. Different policy arrangements for food advertising are likely to contribute to regional variations in advertising patterns. Cities with the lowest advertising rates can be identified as exemplars of good policy practice.
Sodium anilinide-cyclohexylamide pair: synthesis, characterization, and hydrogen storage properties

Jing Z, Yu Y, Chen R, Tan KC, He T, Wu A, et al.

Chem Commun (Camb), 2020 Jan 22.
PMID: 31967625 DOI: 10.1039/c9cc08593a

The lack of efficient hydrogen storage material is one of the bottlenecks for the large-scale implementation of hydrogen energy. Here, a series of new hydrogen storage materials, i.e., anilinide-cyclohexylamide pairs, are proposed via the metallation of an aniline-cyclohexylamine pair. DFT calculations show that the enthalpy change of hydrogen desorption (ΔHd) can be significantly tuned from 60.0 kJ per mol-H2 for the pristine aniline-cyclohexylamine pair to 42.2 kJ per mol-H2 for sodium anilinide-cyclohexylamide and 38.7 kJ per mol-H2 for potassium anilinide-cyclohexylamide, where an interesting correlation between the electronegativity of the metal and the ΔHd was observed. Experimentally, the sodium anilinide-cyclohexylamide pair was successfully synthesised with a theoretical hydrogen capacity of 4.9 wt%, and the hydrogenation and dehydrogenation cycle can be achieved at a relatively low temperature of 150 °C in the presence of commercial catalysts, in clear contrast to the pristine aniline-cyclohexylamine pair which undergoes dehydrogenation at elevated temperatures.