Isolation and antioxidant activity of peptides from Chinese hairy tofu.

Hairy tofu is a famous Chinese snack that is made from soybeans and rich in various nutrients. In order to further explore the antioxidant peptides of hairy tofu hydrolysates, seven proteases were used to hydrolyze hairy tofu. The results of in vitro radical scavenging activity showed that hairy tofu hydrolysates obtained by pancreatin exhibited the highest antioxidant activity. After Sephadex G-25 gel filtration and reversed-phase high-performance liquid chromatography (RP-HPLC), 97 peptides were identified in the most antioxidant fraction using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Among them, nine peptides were synthesized and their antioxidant activities were assessed using a H2O2-induced oxidative 293T cell model. Finally, four peptides (QCESHK, LAWNEGR, NLQGENEWDQK, and FTEMWR) at concentrations of < 50 µg/ml significantly decreased the malondialdehyde content compared with the model group, displaying in vivo antioxidant activity and low cytotoxicity. Overall, this research provided the choice of using hairy tofu peptides as antioxidant products in the pharmaceutical and food industries.

The clinical effect evaluation of multidisciplinary collaborative team combined with palliative care model in patients with terminal cancer: a randomised controlled study.

OBJECTIVE: To evaluate the clinical effect of a multidisciplinary collaboration team combined with a palliative care model in patients with terminal cancer. METHOD: A total of 84 patients diagnosed with terminal cancer in our hospital were included and randomly divided into an intervention group and a control group, with 42 cases in each group. Patients in the intervention group were treated by a multidisciplinary collaborative team combined with the palliative care model, and patients in the control group were treated by routine nursing intervention. The Self-rating Anxiety Scale (SAS) and the Self-rating Depression Scale (SDS) were used to evaluate negative emotions and anxiety and depression of patients before and after intervention. The Quality of Life Scale (European Organization for Research and Treatment of Cancer [EORTC] QLQ-C30) and Social Support Scale (SSRS) were used to evaluate the quality of life and social support of patients. This study has been registered in 13/01/2023 (ClinicalTrials.gov Identifier: NCT05683236). RESULT: The general data of the two groups were comparable. After intervention, the SAS (43.7 ± 7.4 vs. 54.2 ± 9.3) and SDS scores (38.4 ± 6.5 vs. 53.1 ± 8.4) of the intervention group were significantly lower than those of the control group. The total SSRS score, subjective support score, objective support score and utilisation of support of the intervention group were significantly higher than those of the control group (P < 0.05). The overall quality of life score of the intervention group was higher than that of the control group, and the difference was statistically significant (79.5 ± 4.5 vs. 73.2 ± 3.6, P < 0.05). The scores of each functional scale were significantly higher than those of the control group (P < 0.05). CONCLUSION: Compared with conventional nursing, the application of the multidisciplinary collaborative team combined with tranquilisation therapy in patients with terminal cancer can significantly reduce the anxiety and depression of patients, enable patients to obtain comprehensive social support, and effectively improve the quality of life of patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT05683236, 13/01/2023, Retrospectively registered.

[Identification of metabolites of Yiqi Baoyuan Prescription in rat plasma, bile, urine and feces after oral administration].

This study was designed to determine the metabolites of Yiqi Baoyuan Prescription(YQBYP) in rats. The ultra-high performance liquid chromatography coupled to time-of-flight mass spectrometry(UPLC-TOF-MS) and mass defect filter(MDF) were employed to analyze the metabolites of YQBYP in rat plasma, bile, urine and feces. Chromatographic separation was conducted on Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 µm) under gradient elution with 0.1% formic acid aqueous solution(A)-acetonitrile(B), and the column temperature was 30 ℃. Electrospray ion(ESI) source was used under positive and negative ion modes, with capillary voltage of 3.0 kV and mass scanning range of m/z 100-1 000. In this experiment, 9 prototype components and 36 metabolites were identified in rat plasma, bile, urine and feces samples. The results showed that the main metabolic pathways of YQBYP in rats involved methylation, demethylation, oxidation, and other phase Ⅰ reactions as well as glucuronidation, sulfation, and other phase Ⅱ reactions. This study provided scientific basis for clarifying the therapeutic material basis of YQBYP and product development.

[Influence of enteral feeding initiation time on intestinal flora and metabolites in very low birth weight infants: a prospective study]. / ä¸åŒè‚ å† è¥å »å¼€å§‹æ—¶é—´å¯¹æžä½Žå‡ºç”Ÿä½“é‡å„¿è‚ é“èŒç¾¤åŠä»£è°¢äº§ç‰©å½±å“çš„å‰çž»æ€§ç ”ç©¶.

OBJECTIVES: To study the influence of enteral feeding initiation time on intestinal flora and metabolites in very low birth weight (VLBW) infants. METHODS: A total of 29 VLBW infants who were admitted to the Department of Neonatology, Children's Hospital of Chongqing Medical University, from June to December, 2020, were enrolled as subjects. According to the enteral feeding initiation time after birth, the infants were divided into two groups: <24 hours (n=15) and 24-72 hours (n=14). Fecal samples were collected at weeks 2 and 4 of hospitalization, and 16S rDNA high-throughput sequencing and gas chromatography-mass spectrometry were used to analyze the microflora and short-chain fatty acids (SCFAs) respectively in fecal samples. RESULTS: The analysis of microflora showed that there was no significant difference between the two groups in Chao index (reflecting the abundance of microflora) and Shannon index (reflecting the diversity of microflora) at weeks 2 and 4 after birth (P>0.05). The analysis of flora composition showed that there was no significant difference in the main microflora at the phylum and genus levels between the two groups at weeks 2 and 4 after birth (P>0.05). The comparison of SCFAs between the two groups showed that the <24 hours group had a significantly higher level of propionic acid than the 24-72 hours group at week 4 (P<0.05), while there was no significant difference in the total amount of SCFAs and the content of the other SCFAs between the two groups (P>0.05). CONCLUSIONS: Early enteral feeding has no influence on the diversity and abundance of intestinal flora in VLBW infants, but enteral feeding within 24 hours can increase the level of propionic acid, a metabolite of intestinal flora.

LncRNA LINC00337 sponges mir-1285-3p to promote proliferation and metastasis of lung adenocarcinoma cells by upregulating YTHDF1.

BACKGROUND: Emerging studies have shown that long noncoding RNAs (lncRNAs) predominantly function in the carcinogenesis of multiple developing human tumors. The current study aimed to investigate the underlying mechanisms of LINC00337 in lung adenocarcinoma. METHODS: We analyzed TCGA and GTEx datasets and chose LINC00337 as the research object. Cell proliferation, cell apoptosis, cell cycle, migration, and invasion were detected in the gain and loss experiments of LINC00337 both in vitro and in vivo. Moreover, RNA pull-down, luciferase reporter assays, western blotting analysis, and rescue experiments were performed to investigate the underlying molecular mechanisms of LINC00337 function. RESULTS: LINC00337 expression was remarkably upregulated in lung adenocarcinoma. In addition, LINC00337 knockdown was shown to repress cell migration, invasion, and proliferation, as well as the cell cycle, and gear up apoptosis in lung adenocarcinoma in vitro and in vivo. With respect to the mechanism, LINC00337 knockdown boosted miR-1285-3p expression and then restrained YTHDF1 expression post-transcriptionally. Crucially, both miR-1285-3p decrement and YTHDF1 overexpression successfully reversed the influence on cell proliferation, migration, invasion, and apoptosis caused by LINC00337 shRNA. CONCLUSIONS: These results suggest that LINC00337 acts as an oncogenic lncRNA, targeting miR-1285-3p and regulating YTHDF1 expression, to promote the progression of lung adenocarcinoma.

Lower normal free thyroxine is associated with a higher risk of metabolic syndrome: a retrospective cohort on Chinese population.

BACKGROUND: Recently, the relationship between thyroid hormones (THs) across the euthyroid ranges and metabolic syndrome (MetS) has been widely discussed. This study aimed to present specific cutoff values of THs to assess the association between THs and MetS in a euthyroid cohort. METHODS: Data of 2694 subjects, aged 18-80 years, who attended health examination in Xi'an Electric Power Central Hospital from April 2011 to December 2015 were collected and analyzed. The first cohort enrolled 929 participants (followed up by 2221 person-years totally) to assess correlations between serum thyrotropin (TSH), triiodothyronine (T3), thyroxine (T4) levels and MetS. The second cohort included 698 participants (followed up by 1709 person-years totally) to evaluate relationships between serum free triiodothyronine (FT3), free thyroxine (FT4) levels and MetS. MetS was defined according to the criteria of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) scientific statements of 2009. Euthyroidism was defined as serum TSH, FT3 and FT4 levels within the reference ranges without taking any thyroid medication. RESULTS: The cutoff values for TSH, T3, T4, FT3 and FT4 were 2.0mIU/L, 1.9 nmol/L, 117 nmol/L, 4.3 pmol/L and 16 pmol/L, respectively. Participants were categorized into two groups according to cutoff values: the lower-THs group and the higher-THs group. There was no significant difference in the risk of MetS between two groups in TSH, T3, T4 and FT3. The incidence of MetS was significantly higher in lower-FT4 group than higher-FT4 group (1.00 vs 0.622 (0.458, 0.846), P = 0.002). The lower-FT4/higher-TSH group had the highest hazard ratios of MetS. (2.131vs 1.0 (1.380,3.291), P = 0.006). CONCLUSIONS: Lower normal FT4 (FT4 ≤ 16.0 pmol/L) is an independent risk factor for MetS, and lower normal thyroid function (TSH > 2.0 mIU/L and FT4 ≤ 16.0 pmol/L) is associated with a higher risk of developing MetS.

The association between subclinical hypothyroidism and metabolic syndrome: an update meta-analysis of observational studies.

The association between subclinical hypothyroidism (SCH) and metabolic syndrome (MetS) has been widely discussed. This study aimed to conduct an update and comprehensive meta-analysis to reveal the risk of MetS and its components in SCH. PubMed, Embase and ISI Web of Knowledge were searched to identify relevant studies through February 20th, 2020. Review Manager 5.3 and Stata 14.0 were used to conduct the meta-analysis. Both fixed-effects and random-effects models were used. In total, 18 articles (19 studies) incorporating 79,727 participants were included. The pooled OR for MetS comparing subjects with SCH with euthyroid subjects was 1.28 (95% CI: 1.19 to 1.39, p = 0.04, I2 = 40%). Subgroup analysis results showed significant associations of SCH and MetS in the adult subgroup (OR = 1.28, 95% CI: 1.18-1.40), Asian population subgroup (OR = 1.30, 95% CI: 1.19-1.42) and cross-sectional study design subgroup (OR = 1.31, 95% CI: 1.16-1.47). Significant associations of SCH and MetS also existed in all MetS definition criteria subgroups except the Chinese Diabetes Society (CDS) subgroup. SCH was correlated with MetS and was not affected by the subgroup analysis stratified by the proportion of females in the total population, the TSH cutoff value in SCH diagnostic criteria, or the adjustment for confounding factors. SCH was identified to be associated with an increased risk of obesity, hypertension, high triglyceride (TG) levels and low high-density lipoprotein cholesterol (HDL-C) levels. In conclusion, SCH is significantly associated with an increased risk of MetS and four out of five components of MetS.

Effect of Dihydrotestosterone on CostimulatoryMolecules in a Mouse Model of Graves' Disease.

Objective Graves' disease is the most common autoimmune thyroid disease and its prevalence and clinical manifestations are disparate between females and males. Costimulatory molecules play an essential role in regulating autoimmune responses. The objective of this study was to determine if expression of inhibitory molecules was correlated with treatment by dihydrotestosterone (DHT) in an in vivo BALB/c mouse model of experimental autoimmune Graves' disease.Methods Female BALB/c mice were immunized three times with thyroid stimulating hormone receptor A-subunit encoded by adenovirus to establish a Graves' disease model. Three different doses of DHT or a matching placebo were administered by implantation of slow-release pellets a week before the first immunization. Four weeks after the third immunization, the mice were euthanatized, and then the spleen and thymus were removed. Total thyroxine and free thyroxine levels in serum of mice were detected using a radioimmunoassay kit. Real-time polymerase chain reaction was performed to estimate the expression of costimulatory molecules in lymphocytes from the spleen and thymus. Flow cytometry was used to analyze the percentage of CD4+ T cells in splenic lymphocytes. Quantitative data were compared with unpaired t-tests. Correlation between two variables was analyzed using Analysis of Variance.Results Treatment with DHT can dramatically reduce total thyroxine and free thyroxine levels. Higher expression of programmed death-1 was found in the spleen of Graves' disease mice receiving 5 mg of DHT treatment (0.635±0.296 vs. 0.327±0.212; t=2.714, P=0.014), similarly, T-cell immunoglobulin domain and mucin domain 3 (TIM-3) in both the spleen (1.004±0.338 vs. 0.646±0.314; t=2.205, P=0.022) and the thymus (0.263±0.127 vs. 0.120±0.076; t=3.221, P=0.004) also increased after 5 mg of DHT treatment compared with the parallel placebo model mice. Moreover, the percentage of CD4+ T cells declined in the splenic lymphocytes of Graves' disease mice treated with 5 mg of DHT (19.90%±3.985% vs. 24.05%±2.587%; t=2.804, P=0.012). A significant negative association was observed between expression of TIM-3 in the spleen and serum levels of total thyroxine (r=-0.7106, P=0.014) as well as free thyroxine (r=-0.6542, P=0.029).Conclusion This study demonstrates that DHT can ameliorate experimental autoimmune Graves' disease, which may occur by up-regulating expression of programmed death-1 and TIM-3 and inhibiting development of CD4+ T cells.

C-kit signaling promotes human pre-implantation 3PN embryonic development and blastocyst formation.

BACKGROUND: Although in vitro culture system has been optimized in the past few decades, the problem of few or no high quality embryos has been still not completely solved. Accordingly, fully understanding the regulatory mechanism of pre-implantation embryonic development would be beneficial to further optimize the in vitro embryo culture system. Recent studies have found the expression of c-kit in mouse embryo and its promotion effects on mouse embryonic development. However, it is unclear the expression, the role and the related molecular regulatory mechanism of c-kit in human pre-implantation embryo development. Therefore, the present study is to determine whether c-kit is expressed in human pre-implantation embryos, and to investigate the possible regulatory mechanism of c-kit signaling in the process of embryonic development. METHODS: The present study includes human immature oocytes and three pronucleus (3PN) embryos collected from 768 women (28-32 ages) undergoing IVF, and normal 2PN embryos collected from ICR mice. Samples were distributed randomly into three different experimental groups: SCF group: G-1™ (medium for culture of embryos from the pro-nucleate stage to day 3) or G-2™ (medium for culture of embryos from day3 to blastocyst stage) + HSA (Human serum album) solution + rhSCF; SCF + imanitib (c-kit inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + imanitib; SCF + U0126 (MEK/ERK inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + U0126; Control group: G-1™ or G-2™ + HSA solution + PBS; The rate of good quality embryos at day 3, blastulation at day 6 and good quality blastulation at day 6 were analysis. RT-PCR, western blot and immunofluorescence staining were applied to detect the target genes and proteins in samples collected from human or mice, respectively. RESULTS: c-kit was expressed ubiquitously in all human immature oocytes, 3PN embryos and 3PN blastocysts. In the experiment of human 3PN embryos, compared with other groups, SCF group showed obviously higher rate of good quality at day 3, better rate of blastocyst formation at day 6 and higher rate of good quality blastocyst formation at day 6. Furthermore, we observed a higher ETV5 expression in SCF group than that in other groups. Similar results were also found in animal experiment. Interestingly, we also found a higher phosphorylation level of MEK/ERK signal molecule in mice embryos from SCF group than those from other groups. Moreover, inhibition of MEK/ERK signaling would remarkably impeded the mice embryonic development, which might be due to the reduced ETV5 expression. CONCLUSIONS: The present study firstly revealed that c-kit signaling might promote the human pre-implantation embryonic development and blastocyst formation by up-regulating the expression of ETV5 via MEK/ERK pathway. Our findings provide a new idea for optimizing the in vitro embryo culture condition during ART program, which is beneficial to obtain high quality embryos for infertile patients.

Influence of PTGS1, PTGFR, and MRP4 genetic variants on intraocular pressure response to latanoprost in Chinese primary open-angle glaucoma patients.

PURPOSE: The purpose of this study is to evaluate the association between variants in prostaglandin-endoperoxide synthase 1 (PTGS1), prostaglandin F (2α) receptor (PTGFR), and multidrug resistance protein 4 (MRP4) genes and intraocular pressure (IOP) response to latanoprost in Chinese patients with primary open-angle glaucoma (POAG). METHODS: The IOP response to latanoprost was evaluated by percent IOP reduction (%ΔIOP) in the treated eye with the formula %ΔIOP = (Baseline IOP values - IOP values posttreatment) / Baseline IOP values × 100 %. Polymorphisms in PTGS1 (rs3842787 and rs10306114), PTGFR (rs3753380 and rs3766355), and MRP4 (rs11568658 and rs11568668) genes were detected by direct DNA sequencing. The differences among %ΔIOP of genotypes or haplotypes were obtained by use of the Mann-Whitney U test. Association analyses were performed by multiple linear regression analysis. RESULTS: Latanoprost were prescribed to 63 subjects, 60 of which met the inclusion/exclusion criteria for the current study. Notably, the %ΔIOP in the rs11568658 GT heterozygous genotype was 10.4 %ΔIOP lower than that of GG homozygous wild-type on day 7 (15.7 ± 2.52 vs. 26.1 ± 2.88, P=0.003), and the corresponding results in the rs10306114 AG heterozygous genotype and AT haplotype constructed by rs3753380 and rs3766355 on day 7 were 7.2 and 10.3 %ΔIOP (P<0.05). Interestingly, similar results were also observed on day 30 (P=0.008, P=0.006, and P=0.002, respectively). Multiple regression analysis showed that heterozygous genotypes of rs10306114, rs11568658, and carrier of AT haplotype were significantly correlated with the lower %ΔIOP. On day 30, the above variations explained 9.9, 10.7, and 17.7 % of the total variability of %ΔIOP in the Chinese POAG patients, respectively. CONCLUSION: rs10306114, rs3753380, rs3766355, and rs11568658 single-nucleotide polymorphisms (SNPs) correlate with a response to latanoprost treatment in patients with POAG. These SNPs may be important determinants of variability in response to latanoprost.

[Expression of CD163 in children with Epstein-Barr virus infection].

OBJECTIVE: To study the clinical significance of CD163 in the diagnosis and the evaluation of severity and prognosis of childhood hemophagocytic lymphohistiocytosis (HLH). METHODS: Ninety-four children were classified into Epstein-Barr virus (EBV)-positive (n=55) and EBV-negative groups (n=39; control group). The EBV-positive group was subgrouped into infectious mononucleosis (IM; n=47) and HLH (n=8). Serum levels of soluble CD163 were measured using ELISA. Expression of CD163 on mononuclear cells was detected by flow cytometry. RESULTS: The serum levels of soluble CD163 were>10 000 ng/mL in all eight HLH patients (>30 000 ng/mL in 3 cases). The mean serum levels of soluble CD163 in the HLH group were significantly higher than in the control and IM groups (P<0.05). The serum levels of soluble CD163 in EBV-positive children were positively correlated with EBV-DNA copies and serum levels of ferritin and LDH, but were negatively correlated with white blood cell count, neutrophil count, hemoglobin and platelet count. The follow-up after treatment for three HLH patients showed that serum levels of soluble CD163 were significantly reduced, but the soluble CD163 levels rebounded in one patient who was complicated by fungal pneumonia infection. CONCLUSIONS: The levels of serum soluble CD163 may be related to the severity in children with HLH. The EBV-positive children with soluble CD163 levels >10 000 ng/mL should be considered the possibility of HLH.

Visual detection of Hg2+ based on Hg(2+)-xanthine complex preventing aggregation of gold nanoparticles.

Xanthine, which can specifically bind with mercury ion (Hg2+) to form xanthine-Hg(2+)-xanthine complex, was used as Hg2+ binding molecule in this paper. In the absence of Hg2+, imide group of xanthine easily adsorbs onto the surface of gold nanoparticles (AuNPs) and induces aggregation of AuNPs, resulting in a blue color. In the presence of Hg2+, however, the selective binding of xanthine with Hg2+ prevents the AuNPs against xanthine induced aggregation, resulting in a visible color change from blue to red depend on the concentration of Hg2+. Therefore, taking advantage of this phenomenon, a simple, cost-effective and rapid method can be established for Hg2+ visual detection. This method allows the detection of Hg2+ in the range of 0.075-4.0 microM with a detection limit (3sigma/slope) of 15 nM, and exhibits a high selectivity toward Hg2+ over other metal ions. Particularly, as low as 0.5 microM Hg2+ can be easily detected by the naked eye without using any complicated or expensive instruments.

Real-time monitoring of stresses and displacements in cervical nuclei pulposi during cervical spine manipulation: a finite element model analysis.

OBJECTIVE: The objective of this study was to research the distribution of stresses and displacements in cervical nuclei pulposi during simulated cervical spine manipulation (CSM). METHODS: A 3-dimensional finite element model of C3/4~C6/7 was established. The detailed mechanical parameters of CSM were analyzed and simulated. During the process, the changes in stresses and displacements of cervical nuclei pulposi within the model were displayed simultaneously and dynamically. RESULTS: Cervical spine manipulation with right rotation was targeted at the C4 spinous process of the model. During traction, levels of stresses and displacements of the nuclei pulposi exhibited an initial decrease followed by an increase. The major stresses and displacements affected the C3/4 nucleus pulposus during rotation in CSM, when its morphology gradually changed from circular to elliptical. The highest stress (48.53 kPa) occurred at its right superior edge, on rotating 40° to the right. It protruded toward the right superior, creating a gap in its left inferior aspect. The highest displacement, also at 40° right, occurred at its left superior edge and measured 0.7966 mm. Dimensions of stresses and displacements reduced quickly on rapid return to neutral position. CONCLUSION: The morphology of the C3/4 nucleus pulposus changed during CSM with right rotation, and it created a gap in its left inferior aspect. Biomechanically, it is more safe and rational to rotate toward the healthy side than the prolapsed side of the intervertebral disk during CSM. Upon ensuring due safety, the closer the application force is to the diseased intervertebral disk, the better is the effect of CSM.

[Characteristics, Sources Apportionment, and Health Risks of PM2.5-bound PAHs and Their Derivatives Before and After Heating in Zibo City].

Atmospheric polycyclic aromatic hydrocarbons (PAHs) and their derivatives are a global problem that influences the environment and threatens human health. To investigate the characteristics, sources, and health risk assessment of PM2.5-bound PAHs and their derivatives, PM2.5 were collected at an urban site in Zibo from November 5 to December 26, 2020, and the concentrations of 16 conventional PAHs, nine NPAHs, and five OPAHs in PM2.5 were analyzed using gas chromatography-mass spectrometry. Source apportionment of PAHs and their derivatives was conducted using diagnostic ratios and a PMF model, and the health risks of PAHs and their derivatives to adult men and women were evaluated using the source-dependent incremental lifetime cancer risk (ILCR) model. The results showed that the average concentrations of ∑16pPAHs, ∑9NPAHs, and ∑5OPAHs in PM2.5 of Zibo City during the sampling period were (41.61 ± 13.40), (6.38 ± 5.70), and (53.20 ± 53.47) ng·m-3, respectively. The concentrations of the three PAHs increased significantly after heating, which were 1.31, 2.04, and 5.24 times larger than those before heating. During the sampling period, Chr, BaP, and BaA were the dominant components of pPAHs; 9N-Ant and 2N-Flt + 3N-Flt were the dominant components of NPAHs; and ATQ and BZO were the dominant components of OPAHs. Source apportionment results showed that motor vehicles were the main source of PAHs and their derivatives in PM2.5 before heating, whereas after heating, the main sources were the mixed source of coal and biomass combustion and secondary formation. The total BaP equivalent (TEQ) was 14.5 ng·m-3 during the sampling period, and the TEQ increased significantly after heating, which was approximately 1.2 times of that before heating. Assisted by the individual PAH source apportionment results, the ILCR of PM2.5-boundPAHs and NPAHs in Zibo City had a certain potential carcinogenic risk for adult males (1.06 × 10-5) and females (9.32 × 10-6). Among them, the health risks of PAHs from gasoline vehicles, diesel vehicles, and coal/biomass combustion were significantly higher than those from other emission sources.

Secondary structure prediction for complete rDNA sequences (18S, 5.8S, and 28S rDNA) of Demodex folliculorum, and comparison of divergent domains structures across Acari.

According to base pairing, the rRNA folds into corresponding secondary structures, which contain additional phylogenetic information. On the basis of sequencing for complete rDNA sequences (18S, ITS1, 5.8S, ITS2 and 28S rDNA) of Demodex, we predicted the secondary structure of the complete rDNA sequence (18S, 5.8S, and 28S rDNA) of Demodex folliculorum, which was in concordance with that of the main arthropod lineages in past studies. And together with the sequence data from GenBank, we also predicted the secondary structures of divergent domains in SSU rRNA of 51 species and in LSU rRNA of 43 species from four superfamilies in Acari (Cheyletoidea, Tetranychoidea, Analgoidea and Ixodoidea). The multiple alignment among the four superfamilies in Acari showed that, insertions from Tetranychoidea SSU rRNA formed two newly proposed helixes, and helix c3-2b of LSU rRNA was absent in Demodex (Cheyletoidea) taxa. Generally speaking, LSU rRNA presented more remarkable differences than SSU rRNA did, mainly in D2, D3, D5, D7a, D7b, D8 and D10.

[Quantification of Ozone Pollution Transport Based on Four-dimensional Flux Method in Foshan, China].

Quantifying the contribution of transport processes to air pollution events has been a prominent challenge and an important need in regional air pollution prevention and control. The WRF-Chem model was used to simulate a typical regional ozone (O3) pollution event in Foshan, and the four-dimensional flux method was applied to quantify the transport fluxes of ozone and its precursors from the surrounding areas to Foshan and to clarify the contributions of the direct transport of ozone and transport of precursors. The average ozone flux from the surrounding areas to Foshan was 120.3 t·h-1, the volatile organic compound (VOCs) flux was 30.2 t·h-1, and the corresponding ozone formation potential (OFP) was 114.8 t·h-1. By counting the transport fluxes of each ozone pollution event, it was found that the city with the largest ozone flux into Foshan during the pollution period was Guangzhou (contributed 44%); the city with the largest input VOCs flux was Zhaoqing (contributed 48%). The analysis of ozone generation potential due to transported VOCs emissions found that oxygenated volatile organic compounds (OVOCs) contributed the most to OFP, accounting for 47% of the "maximum input events." OVOCs and aromatic hydrocarbons such as formaldehyde, xylenes, aldehydes, acetone, and phenols were the top five species contributing to the OFP, contributing more than 50% of the total OFP, mainly from industrial solvent sources.

Sensitive and selective detection of mercury (II) based on the aggregation of gold nanoparticles stabilized by riboflavin.

Gold nanoparticles (AuNPs) can be stabilized by riboflavin against tris buffer-induced aggregation. However, in the presence of mercury (II) (Hg2+), riboflavin can be released from the AuNPs surface and the riboflavin-Hg2+ complex formed, leading to the aggregation of AuNPs in tris buffer. The aggregation extent depends on the concentration of Hg2+. Based on the aggregation extent, a simple and sensitive method of determining Hg2+ is developed. The method enables the detection of Hg2+ over the concentration range of 0.02-0.8 microM, with a detection limit (3sigma) of 14 nM, and shows excellent selectivity for Hg2+ over other metal ions (Cu2+, Co2+, Cd2+, Pb2+, Mg2+, Zn2+, Ag+, Ce3+, Ca2+, Al3+, K+). More importantly, the method avoids complicated surface modifications and tedious separation processes.

Complete sequence analysis of 18S rDNA based on genomic DNA extraction from individual Demodex mites (Acari: Demodicidae).

The study for the first time attempted to accomplish 18S ribosomal DNA (rDNA) complete sequence amplification and analysis for three Demodex species (Demodex folliculorum, Demodex brevis and Demodex canis) based on gDNA extraction from individual mites. The mites were treated by DNA Release Additive and Hot Start II DNA Polymerase so as to promote mite disruption and increase PCR specificity. Determination of D. folliculorum gDNA showed that the gDNA yield reached the highest at 1 mite, tending to descend with the increase of mite number. The individual mite gDNA was successfully used for 18S rDNA fragment (about 900 bp) amplification examination. The alignments of 18S rDNA complete sequences of individual mite samples and those of pooled mite samples ( ≥ 1000mites/sample) showed over 97% identities for each species, indicating that the gDNA extracted from a single individual mite was as satisfactory as that from pooled mites for PCR amplification. Further pairwise sequence analyses showed that average divergence, genetic distance, transition/transversion or phylogenetic tree could not effectively identify the three Demodex species, largely due to the differentiation in the D. canis isolates. It can be concluded that the individual Demodex mite gDNA can satisfy the molecular study of Demodex. 18S rDNA complete sequence is suitable for interfamily identification in Cheyletoidea, but whether it is suitable for intrafamily identification cannot be confirmed until the ascertainment of the types of Demodex mites parasitizing in dogs.

RAPD-SCAR marker and genetic relationship analysis of three Demodex species (Acari: Demodicidae).

For a long time, classification of Demodex mites has been mainly based on their hosts and phenotype characteristics. The study was the first to conduct molecular identification and genetic relationship analysis for six isolates of three Demodex species by random amplified polymorphic DNA (RAPD) and sequence-characterized amplified region (SCAR) marker. Totally, 239 DNA fragments were amplified from six Demodex isolates with 10 random primers in RAPD, of which 165 were polymorphic. Using a single primer, at least five fragments and at most 40 in the six isolates were amplified, whereas within a single isolate, a range of 35-49 fragments were amplified. DNA fingerprints of primers CZ 1-9 revealed intra- and interspecies difference in six Demodex isolates, whereas primer CZ 10 only revealed interspecies difference. The genetic distance and dendrogram showed the intraspecific genetic distances were closer than the interspecific genetic distances. The interspecific genetic distances of Demodex folliculorum and Demodex canis (0.7931-0.8140) were shorter than that of Demodex brevis and D. canis (0.8182-0.8987). The RAPD-SCAR marker displayed primer CZ 10 could be applied to identify the three Demodex species. The 479-bp fragment was specific for D. brevis, and the 261-bp fragment was specific for D. canis. The conclusion was that the RAPD-SCAR multi-marker was effective in molecular identification of three Demodex species. The genetic relationship between D. folliculorum and D. canis was nearer than that between D. folliculorum and D. brevis.

Phylogenetic relationships in Demodex mites (Acari: Demodicidae) based on mitochondrial 16S rDNA partial sequences.

To confirm phylogenetic relationships in Demodex mites based on mitochondrial 16S rDNA partial sequences, mtDNA 16S partial sequences of ten isolates of three Demodex species from China were amplified, recombined, and sequenced and then analyzed with two Demodex folliculorum isolates from Spain. Lastly, genetic distance was computed, and phylogenetic tree was reconstructed. MEGA 4.0 analysis showed high sequence identity among 16S rDNA partial sequences of three Demodex species, which were 95.85 % in D. folliculorum, 98.53 % in Demodex canis, and 99.71 % in Demodex brevis. The divergence, genetic distance, and transition/transversions of the three Demodex species reached interspecies level, whereas there was no significant difference of the divergence (1.1 %), genetic distance (0.011), and transition/transversions (3/1) of the two geographic D. folliculorum isolates (Spain and China). Phylogenetic trees reveal that the three Demodex species formed three separate branches of one clade, where D. folliculorum and D. canis gathered first, and then gathered with D. brevis. The two Spain and five China D. folliculorum isolates did not form sister clades. In conclusion, 16S mtDNA are suitable for phylogenetic relationship analysis in low taxa (genus or species), but not for intraspecies determination of Demodex. The differentiation among the three Demodex species has reached interspecies level.