Characterization, Hypoglycemic Activity, and Antioxidant Activity of Methanol Extracts From Amomum tsao-ko: in vitro and in vivo Studies.

The dried fruit of Amomum tsao-ko is well-known as a spice as well as a Chinese traditional herb. This study aimed to identify the bioactive constituents in the powder of methanol extract from Amomum tsao-ko (PMEAT) and to evaluate the hypoglycemic and antioxidant effects of PMEAT, in vitro and in vivo. We identified 36 phytochemicals in PMEAT by employing HPLC-MS/MS. PMEAT solution was found to have potent α-glucosidase-inhibiting activity (IC50, 0.145 mg/mL) in vitro, twice as strong as that of acarbose (IC50, 0.273 mg/mL). To investigate the hypoglycemic activity of PMEAT in vivo, we studied the impact of low-dose PMEAT (the addition of 100 mg/kg PMEAT to the mice diet) and high-dose PMEAT (200 mg/kg PMEAT addition) treatments in STZ-induced diabetic mice. After 6 weeks of intervention, significantly decreased fasting blood glucose (FBG) (p < 0.05), significantly decreased area under the curve (AUC) of the oral glucose tolerance test (p < 0.05), significantly decreased HOMA-IR (p < 0.05), and significantly increased HOMA-ß (p < 0.05) were observed in the high-dose PMEAT group. Moreover, we performed an antioxidant activity experiment in vitro. The results showed that PMEAT had a strong ability to scavenge DPPH (IC50, 0.044 mg/mL) as well as ABTS free radicals (IC50, 0.040 mg/mL). In an animal experiment conducted on oxidative damage mice model which was induced by D-glucose and a high-fat diet, we observed significantly increased dismutase (SOD) (p < 0.01), glutathione (GSH) (p < 0.01), and glutathione peroxidase (GSH-Px) (p < 0.01) and significantly reduced malondialdehyde (MDA) and 8-ISO-prostaglandin-PGF2α (8-ISO-PGF2α), after treatment with PMEAT for 90 days. In conclusion, this study reveals the therapeutic potential of Amomum tsao-ko for the treatment of diabetes and helps us discover new antioxidant candidates from natural sources.

Characterization of Volatile Profiles and Correlated Contributing Compounds in Pan-Fried Steaks from Different Chinese Yellow Cattle Breeds through GC-Q-Orbitrap, E-Nose, and Sensory Evaluation.

This study focused on characterizing the volatile profiles and contributing compounds in pan-fried steaks from different Chinese yellow cattle breeds. The volatile organic compounds (VOCs) of six Chinese yellow cattle breeds (bohai, jiaxian, yiling, wenshan, xinjiang, and pingliang) were analyzed by GC-Q-Orbitrap spectrometry and electronic nose (E-nose). Multivariate statistical analysis was performed to identify the differences in VOCs profiles among breeds. The relationship between odor-active volatiles and sensory evaluation was analyzed by partial least square regression (PLSR) to identify contributing volatiles in pan-fried steaks of Chinese yellow cattle. The results showed that samples were divided into two groups, and 18 VOCs were selected as potential markers for the differentiation of the two groups by GC-Q-Orbitrap combined multivariate statistical analysis. YL and WS were in one group comprising mainly aliphatic compounds, while the rest were in the other group with more cyclic compounds. Steaks from different breeds were better differentiated by GC-Q-Orbitrap in combination with chemometrics than by E-nose. Six highly predictive compounds were selected, including 3-methyl-butanal, benzeneacetaldehyde, 2-ethyl-6-methyl-pyrazine, 2-acetylpyrrole, 2-acetylthiazole, and 2-acetyl-2-thiazoline. Sensory recombination difference and preference testing revealed that the addition of highly predictive compounds induced a perceptible difference to panelists. This study provides valuable data to characterize and discriminate the flavor profiles in pan-fried steaks of Chinese yellow cattle.

Dynamics of the Gut Bacteria and Fungi Accompanying Low-Carbohydrate Diet-Induced Weight Loss in Overweight and Obese Adults.

BACKGROUND: Low-carbohydrate (e.g., Atkins) dietary pattern is one of the most effective diets for weight loss, but little is known about the characteristics of the gut microbiota accompanying low-carbohydrate diets-induced weight loss. This study aims to profile dynamics of gut bacteria and fungi accompanying modified Atkins diets-induced weight loss among overweight and obese adults. METHODS: Overweight and obese adults were screened to follow a modified Atkins diet plan (30% of energy from protein, 40% from carbohydrate and 30% from fat). We longitudinally profiled dynamics of gut bacteria and fungi based on 16S rRNA and ITS rRNA gene sequencing data, respectively. RESULTS: A total of 65 participants followed the modified Atkins diets for 20-231 days, with 61 and 27 participants achieving a weight loss of at least 5 and 10%, respectively. Most of the participants who achieved 10% weight loss also experienced improvements on metabolic health. The diversity of gut bacteria and fungi increased after a weight loss of 5% and kept stable thereafter. Bacteria genera including Lachnoclostridium and Ruminococcus 2 from Firmicutes phylum were depleted, while Parabacteroides and Bacteroides from Bacteroidetes phylum were enriched after weight loss. The inter-kingdom analysis found an intensive covariation between gut fungi and bacteria, involving more than half of the weight loss-associated bacteria. CONCLUSIONS: This study confirmed the modulation of bacterial and fungal composition during weight loss with the low-carbohydrate diets and showed previously unknown links between intestinal bacteria and fungi accompanying the weight loss.

[Meta-analysis of studies on cut-off value of serum ferritin for identifying iron deficiency].

OBJECTIVE: To synthesize evidence to discuss the appropriate cut-off value of serum ferritin (SF) for identifying iron deficiency. METHODS: A comprehensive electronic search and manual tracking were performed to collect potential studies on cut-off value of SF for identifying iron deficiency. Most relevant studies were identified according to the inclusion and exclusion criteria and data were extracted. All included studies were divided into three groups according to the cutoff value of SF: 12 -20 microg/L group, 25 microg/ L or 30 microg/L group and 36 - 60 microg/L group. Heterogeneity of the included studies was tested to select proper efficacy model for calculating pooled weighted diagnostic indicators and their 95% CI. Summary receiver operating characteristic (SROC) curve was made and the area under the curve (AUC) and Q * index were calculated respectively for the three groups. Finally, sensitivity analysis were performed. RESULTS: A total of 14 studies were included and were divided into three groups. After the pooled efficacy analysis, we found that the 12 - 20 microg/L group showed the lowest pooled sensitivity (0.767, 95 CI 0.705 -0.821) but highest specificity (0.959, 95 CI 0.934 -0.976). Compared with the other two groups, the pooled sensitivity of 25, 30 microg/L group (0.877, 95 CI 0.799 - 0.933) was highest, its pooled specificity was (0.944, 95 CI 0.888 - 0.977), the pooled sensitivity and pooled specificity of 36 - 60 microg/L group (0.836, 95 CI 0.797 - 0.870), (0.876, 95 CI 0.846 - 0.901)] were both relatively low. In terms of the integrated diagnostic capabilities, the 25, 30 microg/L group showed the highest diagnostic odds ratio (101.42, 95 CI 36.137 - 284.64), the largest AUC (0.9497 +/- 0.039) and the Q * index nearest 1 (0.8901 +/- 0.052) among the three groups. After we removed the studies with samples less than 50 and the studies from Chinese authors, the 25, 30 microg/L group still showed the best diagnostic efficiency. CONCLUSION: 25 or 30 microg/L of SF as the cut-off value of identifying iron deficiency shows high accuracy and good integrated diagnostic capability.

Optical fiber amplifiers based on PbS/CdS QDs modified by polymers.

Optical fiber amplifiers based on PbS/CdS semiconductor quantum dots (QDs) modified by an amphiphilic polymer were demonstrated. Well-defined QDs and an amphiphilic copolymer were first prepared and the amphiphilic copolymer was then used to disperse the QDs into silica sol to allow uniform and reproducible incorporation of QDs into the silica coating of the optical fibers. QD-doped silica sol was deposited on the fusion tapered fiber coupler via dip-coating. A 1550 nm semiconductor light emitting diode as the signal source and a 980 nm laser diode as the pump source were injected into the fiber coupler simultaneously. Through evanescent wave excitation, a signal gain as high as 8 dB was obtained within the wavelength range between 1450 and 1650 nm. In addition, the optical fiber amplifiers based on PbS/CdS QDs showed enhanced thermal stability when compared to amplifiers based on PbS QDs.

Hamiltonian optics formalism for microring resonator structures with varying ring resonances.

We develop a Hamiltonian optics formalism to quantitatively analyze a recently proposed scheme for increasing the delay-time-bandwidth product for microring resonator structures with varying ring resonances [Yang and Sipe, Opt. Lett. 32, 918 (2007)]. This theory is formally compact, simple and physically intuitive. We compare this formalism with the more rigorous transfer matrix method, and conclude that the Hamiltonian optics formalism correctly gives the average dispersion, which essentially determines the group delay as well as the dispersive distortion for pulses in the ps regime or longer.