155 research outputs found
Telecom InP/InGaAs nanolaser array directly grown on (001) silicon-on-insulator
A compact, efficient, and monolithically grown III–V laser source provides an attractive alternative to bonding off-chip lasers for Si photonics research. Although recent demonstrations of microlasers on (001) Si wafers using thick metamorphic buffers are encouraging, scaling down the laser footprint to nanoscale and operating the nanolasers at telecom wavelengths remain significant challenges. Here, we report a monolithically integrated in-plane InP/InGaAs nanolaser array on (001) silicon-on-insulator (SOI) platforms with emission wavelengths covering the entire C band (1.55 μm). Multiple InGaAs quantum wells are embedded in high-quality InP nanoridges by selective-area growth on patterned (001) SOI. Combined with air-cladded InP/Si optical cavities, room-temperature operation at multiple telecom bands is obtained by defining different cavity lengths with lithography. The demonstration of telecom-wavelength monolithic nanolasers on (001) SOI platforms presents an important step towards fully integrated Si photonics circuits
Feasibility study of smartphone application for self-monitoring dietary intake among cancer patients
Objective: Evidence accumulates that optimal nutrition status positively influences cancer treatment outcomes. A "smartphone application" (intelligent dietitian support apps, iDSA) was developed to act as a tool to assist patients in terms of dietary monitoring. This study aimed to examine the feasibility of iDSA for self-monitoring dietary intake among cancer patients.
Method: This was a pilot study. Eligible patients were approached and recruited. Dietitian entered individual estimated energy protein requirement into iDSA after installation. Participants recorded and monitored own daily dietary intake. Dietitian arranged for a two-week follow up to monitor nutritional status (weight and dietary intake).
Results: This study enrolled 14 participants, six males and eight females, with a mean age of 36.4 ± 10.1 years. iDSA improved participants’ nutritional outcomes significantly; weight gained 1.2 ± 0.2 kg, increased energy intake 215 ± 100 kcal/day and protein intake 8 ± 5.1 g/day. There were 92.9% of participants agreed or totally agreed that they were able to monitor and increase dietary intake during using iDSA. However, about 57.1% reported that it was burdensome to record their diet daily and sometimes they forgot to record their food intake.
Conclusion: Self-monitoring dietary intake via intelligent dietitian support apps was feasible among cancer patients. With compliance to iDSA resulted in an increase in dietary intake and body weight after two-week. iDSA usability was rated good and can be used to study dietary intake among cancer patients
Factors affecting the nucleolytic cleavage of DNA by (N,N′-ethylenendiaminediacetato)metal(II) complexes, M(edda). Crystal structure of Co(edda)
M(edda) complexes (Cu, Co, Ni, Zn) have been characterized by UV–visible spectroscopy and ESI-MS to study the species in aqueous solution. The Co complex crystallizes as the octahedral diaqua(N,N′-ethylenediaminediacetato)cobalt(II) monohydrate and its crystal structure is reported. Cu(edda) cleaves plasmid DNA in the presence of hydrogen peroxide better than Co(edda) while the Zn and Ni analogues are inactive. Partial and complete inhibition of DNA cleavage can be effected by radical scavengers and Na2H2EDTA, respectively. The cleavage efficiency of Cu(edda) varies with the concentration of the complex, pH of the buffer and the type of buffer. The difference in nucleolytic efficiency of Cu(edda) and other complexes studied can be explained by the difference in amount of OH radicals produced, as determined by a PNDA assay. ESI-MS and CD studies on the Cu(edda) complex confirms its binding to DNA and results in a non-denaturational type of conformation change
Room-temperature InP/InGaAs nano-ridge lasers grown on Si and emitting at telecom bands
Semiconductor nano-lasers grown on silicon and emitting at the telecom bands are advantageous ultra-compact coherent light sources for potential Si-based photonic integrated circuit applications. However, realizing room-temperature lasing inside nano-cavities at telecom bands is challenging and has only been demonstrated up to the E band. Here, we report on InP/InGaAs nano-ridge lasers with emission wavelengths ranging from the O, E, and S bands to the C band operating at room temperature with ultra-low lasing thresholds. Using a cycled growth procedure, ridge InGaAs quantum wells inside InP nano-ridges grown on patterned (001) Si substrates are designed as active gain materials. Room-temperature lasing at the telecom bands is achieved by transferring the InP/InGaAs nano-ridges onto a SiO2∕Si substrate for optical excitation. We also show that the operation wavelength of InP/InGaAs nano-lasers can be adjusted by altering the excitation power density and the length of the nano-ridges formed in a single growth run. These results indicate the excellent optical properties of the InP/InGaAs nano-ridges grown on (001) Si substrates and pave the way towards telecom InP/InGaAs nano-laser arrays on CMOS standard Si or silicon-on-insulator substrates
Conditioned Medium of Human Menstrual Blood-Derived Endometrial Stem Cells Protects Against MPP+-Induced Cytotoxicity in vitro
Mesenchymal stem cells (MSCs) showed the potential to treat Parkinson’s disease (PD). However, it is unknown whether the conditioned medium of human menstrual blood-derived endometrial stem cells (MenSCs-CM) has the function to alleviate syndromes of PD. In this study, human neuroblastoma SH-SY5Y cells were exposed to neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) for inducing a range of response characteristics of PD. After culturing this cell model with 24 h/48 h collected MenSCs-CM for different days, cell viability, pro-inflammation cytokines, mitochondrial membrane potential (ΔΨm), oxidative stress, and cell apoptosis were detected. Finally, protein assay was performed to detect 12 kinds of neurotrophic factors inside MenSCs-CM. Our results showed that MPP+ caused SH-SY5Y cell viability reduction as an increasing dose and time dependent manner. MPP+ treatment resulted in inflammation, mitochondrial dysfunction, reactive oxygen species (ROS) production accumulation, and apoptosis of SH-SY5Y at its IC50 concentration. Forty-eight hours-collected MenSCs-CM and culturing with the MPP+-treated SH-SY5Y for 2 days are the optimized condition to increase cell viability. Besides, MenSCs-CM was efficacious against MPP+ induced inflammation, ΔΨm loss, ROS generation, and it could significantly decrease cells numbers in late apoptosis stage. What’s more, protein assay showed that MenSCs-CM contained various neuroprotective factors. Our study provided the first evidence that MenSCs-CM has a protective effect on MPP+-induced cytotoxicity in various aspects, and firstly showed that MenSCs can release at least 12 kinds of neurotrophic factors to medium, which may contribute to the protective function of MenSCs-CM to treat PD. This research enlightening that MenSCs-CM is beneficial in the therapy for PD and probably also for other neurodegenerative diseases
Predictors of elevated C-reactive protein among pre-treatment, newly diagnosed breast cancer patients: a cross-sectional study
Background & Aims: Accumulating evidence showed that inflammation contributes markedly to cancer progression,
with C-reactive protein (CRP) being one of the lengthily studied inflammation marker. For breast cancer (BCa), pre-treatment elevated CRP upon diagnosis was linked with increased mortality. This study aimed to identify factors predictive of elevated CRP in pre-treatment BCa population that can serve as potential therapeutic targets to reduce inflammation.Methods: This is a cross-sectional study using multiple logistic regression to identify predictors of elevated CRP among pre-treatment, newly diagnosed BCa patients. Studied variables were socio-demographic and medical
characteristics, anthropometric measurements [body weight, Body Mass Index, body fat percentage, fat mass/fat free mass ratio, muscle mass, visceral fat], biochemical parameters [albumin, hemoglobin, white blood cell (WBC), neutrophil, lymphocyte], energy-adjusted Dietary Inflammatory Index, handgrip strength (HGS), scored Patient Generated-Subjective Global Assessment, physical activity level and perceived stress scale (PSS). Results: A total of 105 participants took part in this study. Significant predictors of elevated CRP were body fat percentage (OR 1.222; 95 % CI 1.099–1.358; p < 0.001), PSS (OR 1.120; 95 % CI 1.026–1.223; p = 0.011), low vs normal HGS (OR 41.928; 95 % CI 2.155–815.728; p = 0.014), albumin (OR 0.779; 95 % CI 0.632–0.960; p = 0.019), and WBC (OR 1.418; 95% CI 1.024–1.963; p = 0.036). Conclusion: Overall, predictors of elevated CRP in pre-treatment, newly diagnosed BCa population were body fat percentage, PSS, HGS category, albumin and WBC
Antimalarial and antitumour activities of the steroidal quinone-methide celastrol and its combinations with artemiside, artemisone and methylene blue
Artemisinin, isolated from the traditional Chinese medicinal plant qīng hāo 青蒿
(Artemisia annua) and its derivatives are used for treatment of malaria. With
treatment failures now being recorded for the derivatives and companion drugs
used in artemisinin combination therapies new drug combinations are urgently
required. The amino-artemisinins artemiside and artemisone display optimal
efficacies in vitro against asexual and sexual blood stages of the malaria parasite
Plasmodium falciparum and are active against tumour cell lines. In continuing
the evolution of combinations of the amino-artemisinins with new drugs, we
examine the triterpenoid quinone methide celastrol isolated from the traditional
Chinese medicinal plant léi gōng téng 雷公藤 (Tripterygium wilfordii). This
compound is redox active, and has attracted considerable attention because
of potent biological activities against manifold targets. We report that celastrol
displays good IC50 activities ranging from 0.50–0.82 µM against drug-sensitive
and resistant asexual blood stage Pf, and 1.16 and 0.28 µM respectively against
immature and late stage Pf NF54 gametocytes. The combinations of celastrol
with each of artemisone and methylene blue against asexual blood stage Pf are
additive. Given that celastrol displays promising antitumour properties, we
examined its activities alone and in combinations with amino-artemisinins
against human liver HepG2 and other cell lines. IC50 values of the aminoartemisinins and celastrol against HepG2 cancer cells ranged from
0.55–0.94 µM. Whereas the amino-artemisinins displayed notable
selectivities (SI > 171) with respect to normal human hepatocytes, in
contrast, celastrol displayed no selectivity (SI < 1). The combinations of
celastrol with artemiside or artemisone against HepG2 cells are synergistic.
Given the promise of celastrol, judiciously designed formulations or structural
modifications are recommended for mitigating its toxicity.https://www.frontiersin.org/journals/pharmacologyBiochemistr
Factors affecting nucleolytic efficiency of some ternary metal complexes with DNA binding and recognition domains. Crystal and molecular structure of Zn(phen)(edda)
The binding selectivity of the M(phen)(edda) (M = Cu, Co, Ni, Zn; phen = 1,10-phenanthroline, edda = ethylenediaminediacetic acid) complexes towards ds(CG)6, ds(AT)6 and ds(CGCGAATTCGCG) B-form oligonucleotide duplexes were studied by CD spectroscopy and molecular modeling. The binding mode is intercalation and there is selectivity towards AT-sequence and stacking preference for A/A parallel or diagonal adjacent base steps in their intercalation. The nucleolytic properties of these complexes were investigated and the factors affecting the extent of cleavage were determined to be: concentration of complex, the nature of metal(II) ion, type of buffer, pH of buffer, incubation time, incubation temperature, and the presence of hydrogen peroxide or ascorbic acid as exogenous reagents. The fluorescence property of these complexes and its origin were also investigated. The crystal structure of the Zn(phen)(edda) complex is reported in which the zinc atom displays a distorted trans-N4O2 octahedral geometry; the crystal packing features double layers of complex molecules held together by extensive hydrogen bonding that inter-digitate with adjacent double layers via π…π interactions between 1,10-phenanthroline residues. The structure is compared with that of the recently described copper(II) analogue and, with the latter, included in molecular modeling
PAX6 Haplotypes Are Associated with High Myopia in Han Chinese
Author name used in this publication: Maurice K. H. Yap2010-2011 > Academic research: refereed > Publication in refereed journalpublished_fina
Efficacy, safety and immunogenicity of a human rotavirus vaccine (RIX4414) in Hong Kong children up to three years of age: A randomized, controlled trial
AbstractBackgroundA phase III, double-blind, randomized, controlled trial was conducted in Hong Kong to evaluate the efficacy, safety and immunogenicity of a human rotavirus vaccine, RIX4414 (Rotarix™) against severe rotavirus gastroenteritis in children up to three years of age.MethodsHealthy infants aged 6–12 weeks were enrolled between 08-December-2003 and 31-August-2005 and received two oral doses of either RIX4414 vaccine (N=1513) or placebo (N=1512) given 2 months apart. Vaccine efficacy was assessed from two weeks post-Dose 2 until the children were two and three years of age. Anti-rotavirus IgA seroconversion rate was calculated pre-vaccination and 1–2 months post-Dose 2 using ELISA (cut-off=20U/mL) for 100 infants. Safety was assessed until the children were two years of age; serious adverse events (SAEs) were recorded throughout the study period.ResultsIn children aged two and three years of life, vaccine efficacy against severe rotavirus gastroenteritis was 95.6% (95% CI: 73.1%–99.9%) and 96.1% (95% CI: 76.5%–99.9%), respectively. The seroconversion rate 1–2 months after the second dose of RIX4414 was 97.5% (95% CI: 86.8%–99.9%). At least one SAE was recorded in 439 and 477 infants who were administered RIX4414 and placebo, respectively (p-value=0.130). Six intussusception cases were reported (RIX4414=4; placebo=2) and none was assessed to be vaccine-related.ConclusionRIX4414 was efficacious, immunogenic and safe in the prevention of rotavirus gastroenteritis for at least two years post-vaccination in Hong Kong children
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