Biexcitons-plasmon coupling of Ag@Au hollow nanocube/MoS2 heterostructures based on scattering spectra.

The strong interaction between light and matter is one of the current research hotspots in the field of nanophotonics, and provides a suitable platform for fundamental physics research such as on nanolasers, high-precision sensing in biology, quantum communication and quantum computing. In this study, double Rabi splitting was achieved in a composite structure monolayer MoS2 and a single Ag@Au hollow nanocube (HNC) in room temperature mainly due to the two excitons in monolayer MoS2. Moreover, the tuning of the plasmon resonance peak was realized in the scattering spectrum by adjusting the thickness of the shell to ensure it matches the energy of the two excitons. Two distinct anticrossings are observed at both excitons resonances, and large double Rabi splittings (90 meV and 120 meV) are obtained successfully. The finite-difference time domain (FDTD) method was also used to simulate the scattering spectra of the nanostructures, and the simulation results were in good agreement with the experimental results. Additionally, the local electromagnetic field ability of the Ag@Au hollow HNC was proved to be stronger by calculating and comparing the mode volume of different nanoparticles. Our findings provides a good platform for the realization of strong multi-mode coupling and open up a new way to construct nanoscale photonic devices.

Effects of catechin on the stability of myofibrillar protein-soybean oil emulsion and the adsorbed properties of myosin at the oil-water interface.

The effects of different concentrations of catechin on the stability of myofibrillar protein-soybean oil emulsions and the related mechanisms were investigated. Adding 10 µmol/g catechin had no obvious effects on the emulsion stability and myosin structure, but 50, 100 and 200 µmol/g catechin decreased the emulsion stability. The microstructure observations showed that 10 µmol/g catechin caused a dense and uniform emulsion to form, whereas 50, 100 and 200 µmol/g catechin induced the merging of oil droplets. The addition of 50, 100 and 200 µmol/g catechin caused a decline in both the total sulfhydryl content and surface hydrophobicity, suggesting protein aggregation, which decreased the adsorption capacity of myosin and the elasticity of interfacial film. These results suggested that higher concentrations of catechin were detrimental to the emulsifying properties of myosin and that the dose should be considered when it is used as an antioxidant.

Effects of ultrasound-assisted curing on the quality and microstructure of low-sodium beef jerky.

The effects of ultrasonic brine on the physicochemical properties, sensory quality and microstructure of low-sodium beef jerkies were investigated. Compared with control jerky brined in 1.5% NaCl solution, both of the direct reduction and partial replacement of 50% NaCl by KCl decreased the sodium content. Ultrasonic treatment resulted in sharp reduction in shear force. KCl substitution together with ultrasonic treatment caused the highest yield, a* value and water content, and the water activity of all groups were below 0.85. Only the direct reduction of NaCl had negative effects on the sensory quality. KCl substitution combined with ultrasonic treatment was the most suitable for producing low-sodium beef jerkies with high quality, possibly because the mixed salt had equal total salt content to control. Meanwhile, the cavitation and mechanical effects of ultrasound may unfold protein structure, increase myofibrillar fragmentation index and break the muscle fiber, thus improving the quality of beef jerky.

Catechins affect the oil-holding capacity of meat batters by changing the structure and emulsifying properties of surface proteins at the fat globules.

The effects of different concentrations of catechins on the oil-holding capacity, myofibrillar proteins (MPs) structure and adsorbed properties of interfacial proteins in meat batters were investigated. The addition of 100 mg/kg catechin had no negative effects on the physicochemical properties of meat batter. However, 500 and 1500 mg/kg catechin caused an increase in drip loss and deterioration of dynamic rheological properties; the total sulfhydryl content, surface hydrophobicity and α-helix ratio of MPs decreased significantly (p < 0.05); in meat emulsions, the emulsifying property was reduced, the particle size increased, and less interfacial protein was absorbed on the fat globules. All concentrations of catechins significantly (p < 0.05) inhibited lipid oxidation in meat batters. Medium and high concentrations of catechins induced aggregation of MPs via covalent and noncovalent interactions between MPs and MPs or MPs and catechins, which destroyed the gel and emulsifying property of protein and eventually decrease the oil-holding capacity of meat batters.

Resonance Photoluminescence Enhancement of Monolayer MoS2 via a Plasmonic Nanowire Dimer Optical Antenna.

Two-dimensional transition-metal dichalcogenides (TMDs) such as monolayer MoS2 exhibit remarkable optical properties. However, the intrinsic absorption and emission rates of MoS2 are very low, thus severely hindering its application in electronics and photonics. Combining MoS2 with a plasmonic optical antenna is an alternative solution to enhance the emission rates of the 2D semiconductor, and this can drastically increase the photoresponsivity of the corresponding photodetector. Herein, we have constructed a plasmonic gap cavity of a nanowire dimer (NWD) system as an optical antenna to brighten the emission of MoS2 off the hot spot. Different from the conventional enhancement concept which occurred in the plasmonic hot spot, the light emission off the nanogap hot spot was thoroughly investigated. We demonstrate that this new plasmonic optical nanostructure leads to a strong enhancement due to the Purcell effect. The NWD optical antenna can trap light to the near field through a high-efficiency plasmonic gap mode (PGM); then the PL emission was enhanced drastically up to 14.5-fold due to the resonance of the plasmonic gap mode (PGM) in the NWD with the excitonic band of monolayer MoS2. Theoretical simulations reveal that this NWD can alter the efficiency of convergence and excitation, which was consistent with our experimental results. This study can provide a pathway toward enhancing and controlling PGM-enhanced light emission of TMD materials beyond the plasmonic hot spot.

Multitime point pepsin testing can double the rate of the diagnosis of laryngopharyngeal reflux.

OBJECTIVE: To study the value of multitime point salivary pepsin testing (MTPSPT) for the diagnosis of laryngopharyngeal reflux (LPR). STUDY DESIGN: Prospective noncontrolled. METHODS: For patients who met the enrollment criteria, the reflux symptom index (RSI) and reflux finding score (RFS) were calculated and salivary pepsin testing was performed. The pepsin test was performed every hour from 7:00 a.m. to 6:00 p.m. by collecting fresh saliva samples. A single positive test result was needed for the diagnosis of LPR. The consistency in the diagnosis of LPR between the two methods was compared with the weighted Cohen's kappa statistic. RESULTS: A total of 204 patients were included. The kappa value between the two methods was 0.566 (p = .00). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MTPSPT were 76.43%, 85.94%, 92.24%, and 62.5%, respectively. We also compared a single pepsin measure at 7 a.m. with the screening results based on the RSI and RFS, and found a much lower kappa agreement value (0.223, p = .00). The sensitivity, specificity, PPV, NPV, and false-negative rate of pepsin testing at 7 a.m. (fasting) were 37.86%, 92.18%, 91.38%, 40.41%, and 58.57%, respectively. CONCLUSION: The use of the result of a single salivary pepsin test in the morning yields a relatively higher rate of missed diagnosis of LPR, and multitime point testing through a day increased the accuracy and sensitivity of detection of LPR twofold compared to a single morning fasting sample. LEVEL OF EVIDENCE: 3.

Association of serum 25-Hydroxyvitamin D with Vitamin D intervention and outdoor activity among children in North China: an observational study.

BACKGROUND: Living at high latitudes is one of the risk factors for vitamin D deficiency in children. However, evidence on vitamin D improvement for this pediatric population to date is limited. This study aims at evaluating the association of different vitamin D intervention methods and outdoor activity on the vitamin D status of children in North China. METHODS: In this observational study, a total of 55,925 children aged 1 month to 18 years old were recruited from pediatric outpatient departments from July 2016 to June 2017. Data on demographics, anthropometric measurements, vitamin D intervention (either prescribed by physicians or given by parents) and outdoor activity were recorded. The serum levels of 25-hydroxycholecalciferol (25(OH)D) were determined by high performance liquid chromatography tandem-mass spectrometry. Logistic regression analysis was performed to assess the association of vitamin D intervention or outdoor activity with blood vitamin D status, adjusted for age, gender, BMI for age, and seasons. RESULTS: The overall rate of hypovitaminosis D was 65.60%. Of the children's outdoor activity, 35.63, 31.95, and 32.42% were below 30 min/d, 30-60 min/d and over 60 min/d, respectively. Furthermore, the proportion of therapeutic intervention, supplementation intervention and no vitamin D intervention among the children was 16.48, 32.87, and 50.65%, respectively. After adjusted for confounding factors, vitamin D intervention was associated with a lower risk of hypovitaminosis D, with OR (95% CI) of 0.191 (0.180, 0.202) in children with therapeutic doses and 0.423 (0.404, 0.443) in those with supplementation doses, compared with children without vitamin D intervention. In addition, longer outdoor time was associated with a lower risk of hypovitaminosis D [0.479 (0.456, 0.504) for 60 min/d, 0.737 (0.701, 0.776) for 30-60 min/d], independent of vitamin D intervention. CONCLUSIONS: High prevalence of vitamin D deficiency was found in children living at high latitudes. Vitamin D intervention and outdoor activity are all negatively associated with children's vitamin D deficiency. Routine vitamin D intervention combined with increased outdoor time might be an effective approach to prevent hypovitaminosis D among children, especially those at school, living at high latitudes.

[An in vitro evaluation of the effect of carboxymethyl chitosan and its composites against Enterococcus faecalis in the root canal].

PURPOSE: To evaluate the bacteriostasis effect of carboxymethyl chitosan and its composites on intracanal E. faecalis. METHODS: The pattern of E. faecalis infecting root canal was established, and then divided into 4 groups(A, B, C and D).They were filled with 2% chlorhexidine solution, 140 mg/mL mixture of carboxymethyl chitosan and chlorhexidine solution, 5 mg/mL carboxymethyl chitosan solution and calcium hydroxide paste respectively and incubated for 7 days. Samples obtained before and after the intracanal medication were plated onto BHI media to determine the colony-forming units (CFU/mL) after 48 hours. The data were analysed using SPSS 13.0 software package. RESULTS: Before intracanal medication, the variance of bacterial counts were not significantly different (P>0.05). After medication, the four groups showed significant difference in bacterial counts immediately(P<0.05).The antimicrobial effects of A and B group were better than group C and D. CONCLUSIONS: The antibiotic activity of 2% chlorhexidine solution and 140 mg/L mixture of carboxymethyl chitosan and chlorhexidine solution to E.faecalis were better. Supported by Key Science and Technology Project of Liaoning Province(2010225001).

[Study of the effect of chitosan and its composites on proliferation and differentiation of mouse osteoblasts].

PURPOSE: A mouse osteoblast cell line, MC3T3-E1, was cultivated in the medium that contained chitosan, type I collagen and recombinant human bone morphogenetic protein-2 in vitro to evaluate the effect of chitosan and its composites on proliferation and differentiation of mouse osteoblasts. METHODS: This study was categorized into 4 groups based on the medium used. Group A: α-MEM medium; group B: CS, type I collagen and α-MEM medium; group C: CS, type I collagen, rhBMP-2 and α-MEM medium. α-MEM medium containing 1%FBS was used in the control group. Cells of each group were cultivated for 1,3,5 and 7 days. The optical density (OD) value at each time point was evaluated with MTT assay and growth curve was drawn to observe the proliferation of osteoblasts. Differentiation of osteoblasts was determined with alkaline phosphatase (ALP) activity assay, alkaline phosphatase staining and alizarin red staining. Alkaline phosphatase activity of each group was measured at day 1, 3, 5 and 7 days. After 7 days of culture, the cells were stained with alkaline phosphatase, and at day 14, the mineralized nodules were stained with alizarin red. Statistical analysis was performed using SPSS13.0 software package. RESULTS: The MTT assay results showed that the OD value was maximal when osteoblasts were cultured in group C. The difference were statistically significant between group C and others (P<0.05). The ALP activity showed that the result of group C was significantly higher than other groups. The increase of ALP activity was significant between group C and control group (P<0.05). However, no significant difference was found between group C and group B (P>0.05). Compared with the control group, group C had more calcium nodules and blue particles than others. CONCLUSIONS: The incorporation of type I collagen and bone morphogenetic protein-2 into chitosan can promote MC3T3-E1 cell proliferation and differentiation better. Supported by Major Science and Technology Project of Liaoning Province (2010225001).

Metabolic profiling of urine in young obese men using ultra performance liquid chromatography and Q-TOF mass spectrometry (UPLC/Q-TOF MS).

Obesity is currently epidemic in many countries worldwide. In the young adult, obesity often accompanies hyperlipemia, which is strongly related to the occurrence and development of obesity-related chronic diseases such as diabetes mellitus, hypertension and cardiovascular disease. This study investigated the differences in metabolomic profiling between obese (with hyperlipemia, n=30) and normal-weight (n=30) young men. Anthropometric parameters and conventional metabolites were measured. There were no significant differences between obese and normal-weight young men in age, height and fasting plasma glucose level. Obese young men showed increased weight, body mass index, fat mass, systolic blood pressure, and triglyeride, total cholesterol and insulin levels, and lower levels of testosterone. The endogenous metabolite profile of urine was investigated by UPLC/Q-TOF MS (ultra performance liquid chromatography and Q-TOF mass spectrometry) with electrospray ionization (ESI). Partial least squares (PLS) enabled clusters to be visualized. Eight urine principal metabolites contributing to the clusters were identified; these included increased L-prolyl-L-proline, leucyl-phenylalanine, and decanoylcarnitine in positive ESI mode (m/z 213.1267, 279.1715 and 316.2459, respectively) and N-acetylornithine, 17-hydroxypregnenolone sulfate, 11ß-hydroxyprogesterone, 5a-dihydrotestosterone sulfate and glucosylgalactosyl hydroxylysine in negative ESI mode (m/z 173.0931, 411.1883, 331.185, 369.1751 and 485.1875, respectively). These metabolite changes in obese men suggested early changes of metabolism in young-male obesity with hyperlipemia. The study may further aid the clinical prevention and treatment of obesity and related chronic disease.