[Simultaneous determination of six rare sugars in solid foods by high performance liquid chromatography-evaporative light-scattering detection].

Excessive sugar consumption is associated with metabolic health problems. Rare sugars are gradually being used as substitutes for sugar, and their consumption is increasing daily, raising food-safety issues such as false advertising, adulteration, and overdosing. The determination of rare-sugar compounds has attracted considerable attention in recent years. However, no standard method for the simultaneous determination of six rare sugars (allulose, tagatose, trehalose, isomaltulose, erythritol, and mannitol) in solid foods is available. Therefore, establishing a suitable analytical method for these sugars is necessary. In this study, high performance liquid chromatography coupled with evaporative light-scattering detection was used to determine rare sugars in solid foods. The optimum chromatographic and detector conditions were determined by evaluating the instrument parameters. Analysis was carried out on a Zorbax Original NH2 column (250 mm×4.6 mm, 5 µm) via flow-rate gradient elution (0-15 min, 1.0 mL/min; 15-18 min, 1.0-2.0 mL/min; 18-25 min, 2.0 mL/min) with acetonitrile-water (80∶20, v/v) as the mobile phase. Sharp and symmetric chromatographic peaks were obtained under these conditions. The resolutions for all the six rare sugars were greater than 1.5. Optimization of the evaporative light-scattering detector was extremely important to the responses of the rare-sugar compounds. The two most significant parameters were the nebulizer carrier gas flow rate and drift tube temperature. The detection system was operated under the following conditions: the drift tube temperature was set to 50 ℃, the nebulizer carrier gas was high-purity nitrogen, the carrier gas flow rate was 1.0 mL/min, the nitrogen pressure was regulated to 275.79 kPa, and the gain factor was set to 3. The sample was extracted with 25 mL of water, shaken and vortexed for 10 min, purified with 200 µL of zinc acetate solution and 200 µL of potassium ferricyanide solution, and centrifuged at 4500 r/min for 10 min. Next, 1 mL of the supernatant was passed through a 0.22 µm aqueous-phase filter membrane, and the filtrate obtained was analyzed using the evaporative light-scattering detector. The six rare sugars were quantitatively analyzed using the external standard method and showed good linearity with coefficients of determination (R2) greater than 0.9985. The limits of detection and quantification were 0.020-0.60 and 0.60-1.8 g/100 g, respectively. In addition, when blank solid food samples were spiked with the analytes at three levels, the average recoveries of the six rare sugars were 92.6%-103.2%, with relative standard deviations (RSDs) of 0.7%-4.4%. An RSD of <5% indicated that the method had good precision. Interference experiments were performed to determine whether the sugars and artificial sweeteners commonly found in solid foods affected the targets. The method established in this study was used to analyze the contents of the six rare sugars in actual solid food samples. The experimental results showed various levels of rare glycoconjugates in different solid foods. Moreover, the actual compositions and labeled of rare glycoconjugates in the solid foods were generally consistent. The proposed method features simple operation, rapid results, high sensitivity, and good reproducibility; thus, it meets the requirements for the detection of the six rare sugars in solid foods. It also provides technical support for the development of methodological standards and detection limits for rare sugars in Chinese foods. The results of this study are of great relevance for the daily monitoring of the levels of the six rare sugars in solid foods.

Heterogeneous Structural Color Conductive Photonic Organohydrogel Fibers with Alternating Single and Dual Networks.

Intelligent interactive electronic devices can dynamically respond to and visualize various stimuli, promoting the rapid development of flexible electronics. In this paper, an alternating single- and dual-network design strategy was developed for ingeniously constructing an interactive electronic fiber sensor with heterogeneous structural color (HSCEF sensor). The resulting sensor can rapidly output the synchronous electrical and optical dual signals under strain by adjusting the transport distance of conductive ions and the lattice spacing of the photonic crystal (∼200 ms). Meanwhile, the addition of low-freezing-point glycerol endowed the HSCEF sensor with excellent low-temperature tolerance (-25 °C) and cyclic stability. Notably, benefiting from the alternating single- and dual-network structure, the HSCEF sensor exhibits attractive heterogeneous structural color, which achieves colorimetric changes in the full visible light region with high mechanochromic sensitivity (2.25 nm %-1) and large wavelength shift (Δλ ∼ 225 nm). An intelligent wearable interactive sensor is finally used for real-time dynamic detection of joint movements, realizing precise resolution of different amplitudes. This work provides a general strategy to transform conventional photonic gels into heterogeneous structural color ones, and the developed new interactive sensor with rich optical information could be further used for visual health and exercise monitoring, intelligent soft robotics, wearable sensors, etc.

Role of argon plasma coagulation in treatment of esophageal varices.

With the development of endoscopic therapy, argon plasma coagulation (APC) has been widely used by endoscopists. It has many advantages, such as simple to operate, low cost, and minimal invasiveness. Because of its capability of lesion ablation and hemostasis, APC has several indications in the gastrointestinal tract. One of them is esophageal varices. The aim of this review is to summarize the research on APC in this field to provide a reference for clinical practice.

Clinical significance of E-Cadherin and ß-catenin in early gastric cancer: A protocol of systematic review.

BACKGROUND: This study will summarize the clinical significance of E-Cadherin and ß-catenin in early gastric cancer (EGC). METHODS: Eligible case-control studies were searched from Cochrane Library, PUBMED, EMBASE, PsycINFO, Google Scholar, CBM, and CNKI from inception to the present. In addition, we will also search other sources to avoid missing potential studies. Two authors will independently carry out study selection, data collection, and study methodological quality. A fixed or random-effects model will be utilize to synthesize the data, and RevMan 5.3 software will be used for data analysis. RESULTS: This study will summarize all eligible studies to investigate the clinical significance of E-Cadherin and ß-catenin in EGC. CONCLUSION: The findings of this study may present a genuine understanding of perspective on the clinical significance of E-Cadherin and ß-catenin in EGC.

Zwitterionic pH-responsive hyaluronic acid polymer micelles for delivery of doxorubicin.

As zwitterionic polymers show great promise in drug delivery, hyaluronic acid (HA) was deacetylated and grafted with dodecylamine to prepare a pH-sensitive zwitterionic polymer dHAD used as a carrier for antitumor drugs. The polymer was negatively charged at pH 7.4 and became positive at pH 6.2. In vitro delivery of DOX against MCF-7 cells showed that the blank micelle dHAD had low cytotoxicity and the dHAD-DOX micelles could greatly prohibit the growth of the MCF-7 cells. In addition, the dHAD-DOX micelles had higher cellular uptake, indicating that the micelles were rapidly internalized into the cells via CD44 receptor-mediated endocytosis. The in vivo delivery of DOX to tumor-bearing mice confirmed that the dHAD-DOX micelles greatly inhibited the tumor growth and significantly reduced systemic toxicity of DOX. These results demonstrated that biocompatible pH-responsive zwitterionic dHAD micelles are promising carriers for the delivery of DOX.

Fabrication of Poly(styrene-co-maleic anhydride)@Ag Spheres with High Surface Charge Intensity and their Self-Assembly into Photonic Crystal Films.

Herein, we developed a method to prepare monodisperse poly(styrene-co-maleic anhydride)@Ag (PSMA@Ag) core-shell microspheres with high surface charge intensity by using an in situ reduction method. In this method, ethylenediamine tetraacetic acid tetrasodium salt (Na4EDTA) was used as a reducing agent to promote the growth of Ag, and at the same time endowed the PSMA@Ag spheres with a surface charge. The monodispersity of PSMA and PSMA@Ag and the ordered array of the photonic crystal films were characterized by using SEM. The formation of Ag nanoparticles was confirmed by using TEM, HR-TEM, and XRD characterizations. Due to the existence of surface charges, the obtained PSMA@Ag microspheres easily self-assembled to form photonic crystal structures. In addition, the surface-enhanced Raman scattering (SERS) activity of the PSMA@Ag photonic crystal films was evaluated by detecting the signal from Raman probe molecules, 4-aminothiophenol (4-ATP). The PSMA@Ag photonic crystal films exhibited a high SERS effect, a low detection limit of up to 10-8 for 4-ATP, good uniformity, and reproducibility.

eIF3a improve cisplatin sensitivity in ovarian cancer by regulating XPC and p27Kip1 translation.

The eukaryotic translation initiation factor 3a (eIF3a) is one of the core subunits of the translation initiation complex eIF3, responsible for ribosomal subunit joining and mRNA recruitment to the ribosome. Our previous study identified that it was correlated with platinum response in lung cancer. The current study aims to test the hypothesis that eIF3a may affect the drug response and prognosis of ovarian cancer patients receiving platinum-based chemotherapy by regulating xeroderma pigmentosum complementation group C (XPC) and p27(Kip1). Immunohistochemistry and western blot was used to determine the expression of eIF3a in 126 human ovarian cancer tissues followed by association analysis of eIF3a expression with patient's response and survival. Ectopic over-expression and RNA interference knockdown of eIF3a were carried out in A2780/cisplatin (DDP) and its parental A2780 cells, respectively, to determine the effect of altered eIF3a expression on cellular response to cisplatin by employing MTT assay. Western Blot analyses were also carried out to determine the regulation of eIF3a on XPC and p27(Kip1). eIF3a expression was associated with response of ovarian cancer patients to DDP-based chemotherapy and their survival. Overexpression and knockdown of eIF3a increased and decreased the cellular response to cisplatin in A2780/DDP and A2780 cells, respectively. In addition, XPC and p27(Kip1) were down regulated by eIF3a. eIF3a improves ovarian cancer patients' response to DDP-based chemotherapy via down regulating XPC and p27(Kip1).

Novel gemini cationic lipids with carbamate groups for gene delivery.

To obtain efficient non-viral vectors, a series of Gemini cationic lipids with carbamate linkers between headgroups and hydrophobic tails were synthesized. They have the hydrocarbon chains of 12, 14, 16 and 18 carbon atoms as tails, designated as G12, G14, G16 and G18, respectively. These Gemini cationic lipids were prepared into cationic liposomes for the study of the physicochemical properties and gene delivery. The DNA-bonding ability of these Gemini cationic liposomes was much better than their mono-head counterparts (designated as M12, M14, M16 and M18, respectively). In the same series of liposomes, bonding ability declined with an increase in tail length. They were tested for their gene-transferring capabilities in Hep-2 and A549 cells. They showed higher transfection efficiency than their mono-head counterparts and were comparable or superior in transfection efficiency and cytotoxicity to the commercial liposomes, DOTAP and Lipofectamine 2000. Our results convincingly demonstrate that the gene-transferring capabilities of these cationic lipids depended on hydrocarbon chain length. Gene transfection efficiency was maximal at a chain length of 14, as G14 can silence about 80 % of luciferase in A549 cells. Cell uptake results indicate that Gemini lipid delivery systems could be internalised by cells very efficiently. Thus, the Gemini cationic lipids could be used as synthetic non-viral gene delivery carriers for further study.

[Study on the iodine status of pregnant women and thyroid function of neonate in high iodine area].

OBJECTIVE: To reveal the iodine status of pregnant women and its impact on thyroid function of neonates in high iodine area. METHODS: A total of 210 pregnant women were chosen from a hospital in Haixing county, Hebei province. Pregnant women's random urinary and neonates' cord blood were collected. The urinary iodine concentration (UIC) was examined by arsenic-cerium catalytic spectrophotometry. The levels of free triiodothyronine (FT3), free thyroxine (FT4) and sensitive thyroid-stimulating hormone (sTSH) in serum were measured by chemiluminescence. RESULTS: The age of 210 pregnant women was (27.69 +/- 4.73) years old, whose urinary iodine median (inter-quartile range ) was 1240.70 (1292.68) microg/L. 84.3% (177/210) of the pregnant women had excessive iodine intake (UIC > or = 500 microg/L), 13.8% (29/210) had more than adequate iodine intake( UIC within 250 - 499 microg/L), 0.5% (1/210) had adequate iodine intake (UIC within 150 - 249 microg/L) and 1.4% (3/210) had insufficient iodine intake (UIC < 150 microg/L). The average serum level of FT3, FT4 in neonates were (2.93 +/- 0.59), (15.03 +/- 1.92) pmol/L, respectively. The median (inter-quartile range) of serum sTSH in neonates were 7.33 (5.59) mU/L 78.1% (164/210) of the neonates' serum TSH were beyond 5 mU/L. There were no correlation between pregnant women's urinary iodine level and neonates' serum FT3 and sTSH level (P > 0.05), but there was a positive correlation between pregnant women's urinary iodine level and neonates' serum FT4 level (P < 0.01). Serum FT4 level of the neonates with whose mothers had insufficient iodine intake ((12.99 +/- 1.10) pmol/L) were statistically lower than those with their mothers had excessive iodine intake (15.16 +/- 1.83) pmol/L) (P < 0.05). CONCLUSION: Most of the pregnant women in high iodine area were excessive for iodine nutrition, but still a few pregnant women had insufficient iodine nutrition. The level of neonates' serum sTSH were relatively high and monitoring of risk of hypothyroidism and subclinical hypothyroidism should be strengthened.

A simple and practical solvent-free preparation of polymaleimide.

Polymaleimide (PMAI) was synthesized by reacting polymaleic anhydride (PMA) with urea via a solvent-free reaction at 180 °C. The conversion of PMA could reach 95%. This method is simple, practical and environmentally-friendly. The structure of the resulting PMAI was characterized by ¹H-NMR and IR.

Metabolism of benzo[a]pyrene in peroxynitrite/Fe(III) porphyrin system.

The peroxynitrite/porphyrin biomimetic system was established to investigate the effects of peroxynitrite on benzo[a]pyrene (B[a]P) metabolism. Three model systems consisting of different iron porphyrins were compared, and the results showed that the peroxynitrite/T(p-Cl)PPFeCl system was the highest catalytic efficiency in the metabolism of B[a]P. We analyzed the B[a]P metabolites produced from this system by RP-HPLC method and firstly identified the formation of nitrobenzo[a]pyrenes which are the special metabolites of B[a]P induced by peroxynitrite.

Genetic analysis of oil content in Brassica napus L. using mixed model of major gene and polygene.

The joint segregation analysis of a mixed genetic model of major gene plus poly-gene was conducted to study the inheritance of oil content in Brassica napus L.. Five populations, i.e the populations of 2 parents (P1 and P2), F1, F2 and F2:3 (derived from F2) family, from each of the two crosses (1141B x Ken C-1, 32B x Ken C1-2) were investigated.The frequency distributions of oil content in F2 and F2:3 family populations show characteristics of a mixed normal distribution, which indicated that the inheritance of oil content followed a major gene plus poly-gene model. Twenty-one genetic models were established, which could be classified into five types: one and two major genes, polygenes, one and two major genes plus polygenes. The most suitable genetic model could be selected using Akaike's Information Criterion and the fitness of the selected one could be examined by a set of tests. Results show that genetic model D-2 is the most fitting genetic model for the trait. In other words, oil content in oilseed rape is controlled by one additive major gene plus additive and dominance polygenes. For cross 1 (1141B x Ken C1-1) the heritabilities of major gene and poly-genes in F2 are 68.21% and 27.17%, respectively, and in F2:3 are 81.70% and 16.80%, respectively. The additive effect of major gene is -1.74, which indicates that the locus of the allele in parent 1141B may decrease the oil content, but that in parent Ken C1-1 may increase it. The additive and dominance effects of the polygenes are 1.20 and -1.93, respectively. For cross 2 (32B x Ken C1-2) the heritabilities of major gene and polygenes in F2 are 66.20% and 28.10%, respectively, and in F2:3 were 81.00% and 14.90%, respectively. The additive effect of major gene was -3.74, which also indicates that the locus of the allele in parent 32B may decrease the oil content, but that in parent Ken C1-2 may increase it. The additive and dominance effects are -1.99 and 0.93, respectively. The heritability of the major gene in F2:3 is higher than that in F2 in both crosses, so it would be more efficent to conduct selection in F2:3 families for high oil content in breeding.

[Charge control and IR analysis of amine on diarylide yellow pigment PY14].

To study the reaction of amine with dairylide yellow pigment (PY14) used in electrophoretic display, especially the reaction mechanism between polyisobutylene imide (PIBI) and PY14, some amines were selected to react with PY14. At the same time, tetraethylene pentamine was treated with HCl. The zeta potential and IR of the above products were tested. Based on the zeta potential and IR frequency, the charge control intensities of different amines on PY14 were compared, and it is confirmed that the reaction of PY14 with amines is Lewis reaction, the charge control of secondary and primary amines with less steric obstacle is stronger. The PY14 zeta potential value reverse is due to the adsorption of bigger reverse ion.

[Treating defective damage of facial nerve with great auricular nerve grafting covered by pediculated fascial tube].

OBJECTIVE: To study the curative effect of grafting great auricular nerve with pediculated fascial tube in defective damage of facial nerve. METHODS: All the 7 patients in this study were treated by grafting great auricular nerve covered by pediculated fascial tube near facial nerve trunk. RESULTS: Four cases with otogenic facial paralysis had grade III - IV recovery of facial nerve function from two to two and half years after the nerve grafting operation. Three patients post-traumatic facial paralysis had grade III recovery of facial nerve function 2 years after the nerve grafting operation. CONCLUSIONS: The grafting of pediculated fascial tube surrounded great auricular nerve can provide a biological environment with better blood supply for the plerosis and regeneration of nerve and can accelerate the functional recovery of nerves after the nerve grafting.

[Analysis of sucrose esters by thin-layer chromatography].

The thin-layer chromatographic method of sucrose esters was developed by the use of toluene-ethyl acetate-methanol-water (10:5:4.5:0.2 in volume ratio) as a mobile phase. Sucrose esters were developed by ascending technique on the silica gel G plate, visualized by urea-phosphoric acid-n-butanol with blue spots. The Rf value of monoester was 0.16 and those of higher esters were 0.38 - 0.93. The calibration curve was linear in the range of 25 microg - 250 microg with the detection limit of 0.1 microg. Accuracies were certified by normalization method and external standard method with t-test. The results were /t/ = 0.627(< 2.571) and /t/ = 1.123(<2.571) and RSDs were 3.03% and 3.08% (n = 6) respectively for S-1570. Contents of monoester of different sucrose esters were determined, which could provide reference for synthetic conditions and application range of sucrose esters.