[Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020].

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

[Antimicrobial resistance and genomic characterization of Campylobacter isolates recovered from retailed poultry meat samples in 20 provinces of China in 2020].

Objective: To understand the antimicrobial resistance and genome characteristics of Campylobacter isolates recovered from retailed poultry meat samples in 20 provinces in China in 2020. Methods: In 2020, 265 Campylobacter strains including 244 Campylobacter jejuni and 21 Campylobacter coli collected from retailed poultry meat samples in China were tested for antimicrobial resistance to 9 antimicrobial compounds by using the agar dilution method. Forty-two selected isolates were sent for whole genome sequencing and 38 high-quality genomes were analyzed for their antimicrobial resistance genes, virulence genes, sequence types and genetic diversity. Results: The resistance rates of Campylobacter isolates from poultry meats to tetracycline, nalidixic acid and ciprofloxacin were the highest (84%-100%), with 53.2% of the isolates showing multidrug resistance in this study. The resistance rates of C. coli to erythromycin, azithromycin, telithromycin, gentamicin and clindamycin were significantly higher than those of C. jejuni (P<0.05). The resistance genes conferring resistance to ß-lactams (100%, 38/38), quinolones (94.7%, 36/38), tetracycline (81.6%, 31/38) and aminoglycosides (50%, 19/38) were the most frequently detected among 38 Campylobacter genomes. C. jejuni carried more virulence genes than C. coli. In total, 19 and 17 sequence types (ST) were obtained from 20 sequenced C. jejuni and 18 C. coli isolates, respectively, including 5 novel STs. The isolates showed a high genetic diversity based on their sequence types. Conclusion: The phenomenon of antimicrobial resistance in Campylobacter from poultry meat sources in China is relatively serious, and resistance and virulence genes are widely distributed in Campylobacter. There is genetic diversity in Campylobacter.

Synthesis of hierarchically structured T-ZnO-rGO-PEI composite and their catalytic removal of colour and colourless phenolic compounds.

Phenolic compounds bisphenol A (BPA) and 4-nitrophenol (4-NP) are the prime water contaminants. As reported, these compounds are some of the highly hazardous ones to the human and living species. In this study, T-ZnO-rGO-PEI composite was synthesized employing hydrothermal method and the obtained composite samples were systematically characterized by FTIR, XPS, FE-SEM and HR-TEM studies. The FTIR, XPS analysis confirmed the successful surface modification of T-ZnO-rGO-PEI composite. The FE-SEM morphology confirmed the formation of ZnO (arm length about 2.5 µm) tetrapod structured in synthesized T-ZnO-rGO-PEI composite. The thickness of formed ZnO arm (0.44 µm) was increased after the polymer coating which confirmed the successful surface modification by PEI polymer. The HR-TEM images confirm the uniform coating of PEI polymer on T-ZnO-rGO surface. The catalytic activity and adsorption capacity of the synthesized T-ZnO-rGO-PEI composite was successfully explored using 4-nitrophenol and bisphenol-A as model pollutants .T-ZnO-rGO-PEI composite and found that 4-NP reduction reaction was completed within 10 min with the rate of 0.224 min-1. The BPA adsorption over T-ZnO-rGO-PEI exhibited high adsorption rate of 0.0210 min-1. In addition, the detailed 4-NP reduction and BPA adsorption mechanism was demonstrated. Hence the synthesized T-ZnO-rGO-PEI composite is a promising catalyst for the removal of micropollutants in aqueous medium.

Surface-tuned hierarchical ɤ-Fe2O3-N-rGO nanohydrogel for efficient catalytic removal and electrochemical sensing of toxic nitro compounds.

4- Nitrophenol (4-NP) is a top rated hazardous environmental pollutant and secondary explosive chemicals. For the sake of ecology and environment safety, the catalytic reduction and detection of 4-NP is highly important. In this work, ɤ-Fe2O3-nitrogen doped rGO (ɤ-Fe2O3-N-rGO) nanohydrogel was synthesized by green hydrothermal method. The morphology and phase purity of prepared ɤ-Fe2O3-N-rGO nanohydrogel were confirmed by various analytical (SEM, TEM, XRD, and XPS) and electrochemical techniques. The morphological structure of ɤ-Fe2O3-N-rGO nanohydrogel confirmed that the nanocrystals are well covered over the 2D N-rGO layer. Further, ɤ-Fe2O3-N-rGO nanohydrogel was applied for the catalytic reduction and electrochemical detection of ecotoxic 4-NP. A low cost, ɤ-Fe2O3-N-rGO nanohydrogel displayed an excellent catalytic activity, high recyclability (>5 cycles) and high conversion efficiency of 4-NP to 4-Aminophenol (4-AP). In addition, ɤ-Fe2O3-N-rGO nanohydrogel modified GCE displayed a wide linear sensing range (0.1-1000 µM), and a low detection limit (LOD) of 0.1 µM with excellent sensitivity, high selectivity (<1.2%) and good stability (>4 weeks). The developed sensor electrode shows the low reduction potential of -0.3 V and -0.60 V for the determination of 4-NP. The proposed ɤ-Fe2O3-N-rGO nanohydrogel is promising catalyst for the detection and removal of toxic aromatic nitro compounds in real site applications.

[Molecular epidemiology of Listeria monocytogenes isolated from ready-to-eat food in 2017 in China].

Objective: To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China. Methods: A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. Results: All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Conclusion: Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

[Etiological characteristics of Streptococcus pyogenes isolated from children with scarlet fever in Tianjin from 2012 to 2016].

Objective: To investigate the etiological characteristics of Streptococcus pyogenes that caused scarlet fever from 2012 to 2016 in Tianjin. Methods: The subjects were children diagnosed clinically as scarlet fever in Tianjin scarlet fever monitoring hospital from 2012 to 2016. The exclusion criteria were children with scarlet fever who were unable to cooperate with sampling. A total of 575 cases of children's swabs were collected. Biochemical methods were used to isolate and identify the bacteria of pharynx swab, and the PCR method was used to detect the emm genotyping and superantigen speA and speC, and the resistance of the strains to 10 antibiotics was measured by K-B paper method. We compared the carrying status of superantigen genes by different types of GAS and the resistance of all GAS to different antibiotics. Results: There were 5 emm types (emm1/11/12/22/89). The dominant types were emm12 (52.9%, 100 strains) and emm1 (44.4%, 84 strains). The carrying rates of speA and speC genes were 21.7% (41 strains) and 76.7% (145 strains), respectively. The speA gene carrying rate of emm1 type GAS was 33.3% (28 strains), which were higher than that of emm12 (12% (12 strains)) (χ(2)=12.21, P<0.001). The speA and speC gene simultaneous carrying rate of emm1 type GAS was 27.4% (23 strains), which was higher than that of emm12 type (12% (12 strains)) (χ(2)=7.01, P=0.008). The percentages of the strains that were resistant to Azithromycin, Erythromycin, Clarithromycin, Clindamycin, Tetracyclin, Levofloxacin and Chloramphenicol were 96.8% (183 strains), 96.3% (182 strains), 92.1% (174 strains), 92.1% (174 strains), 73.0%(138 strains), 2.1% (4 strains) and 1.6% (3 strains), respectively. All isolates were susceptible to Penicillin, Cefazolin and Vancomycin, and there were statistical significance (χ(2)=953.28, P<0.001). Conclusion: The dominant emm types causing scarlet fever are emm12 and emm1. The frequencies of speA and speC in emm1 and emm12 are different. S.pyrogenes in Tianjin were susceptible to penicillin, cefazolin and vancomycin, but highly resistant to the clindamycin, clarithromycin, erythromycin and azithromycin.

Atorvastatin improves plaque stability in diabetic atherosclerosis through the RAGE pathway.

OBJECTIVE: To study the improving effect of atorvastatin on plaque stability in diabetes mellitus (DM) mice complicated with atherosclerosis. MATERIALS AND METHODS: Apolipoprotein E (ApoE)-/- mice were used to establish the DM mouse model. Half of the mice received atorvastatin after successful modeling. ApoE-/- and C57BL/6J mice were used as controls. Oil red O staining and Masson staining were performed to detect the lipid and collagen components in mice. Immunohistochemical assay was used to observe the expressions of smooth muscle cell (SMC) and Ly-6c. The expressions of receptor for advanced glycation end products (RAGE), monocyte chemoattractant protein-1 (MCP-1) and nuclear factor-κB (NF-κB) in tissues were detected by Western blotting. Finally, the levels of serum soluble RAGE (sRAGE), advanced glycation end products (AGEs), malondialdehyde (MDA) and reduced glutathione (GSH) in mice were also detected. RESULTS: Atorvastatin reduced the area of atherosclerotic plaque and improved the stability of arterial plaque through reducing lipid deposition, the number of macrophages and SMC, increasing collagen fibers. In mice in atorvastatin group, the levels of serum AGEs and sRAGE were decreased. Moreover, atorvastatin inhibited the downstream pathway of RAGE as well as DM, thus inducing the oxidative stress. CONCLUSIONS: Atorvastatin improves plaque stability in diabetic atherosclerosis through the RAGE pathway.

A stress-induced cellular aging model with postnatal neural stem cells.

This corrects the article DOI: 10.1038/cddis.2014.82.

[Liquid milk exposure and risk assessment of thiocyanate in Chinese populations].

Objective: To analyze liquid milk exposure of thiocyanate among Chinese population and preliminarily assess its health risk. Methods: A total of 2 059 raw milk samples were collected during 2013 and 2014 from 12 Chinese provinces, New Zealand and Netherlands. Farms were chosed according to the main sources of dairy companies, the distribution of farms and the yield of milk. Content of thiocyanate were detected by ion chromatography. Liquid milk consumption data were taken from Chinese beverage and alcoholic beverage consumption survey in 18 cities or counties in 9 provinces, including 16 775 subjects older than 3. A simple distribution model was used to estimate the exposure of thiocyanate from liquid milk. The tolerable daily intake (TDI) of thiocyanate was made 0.08 mg·kg(-1)·d(-1). Then the exposures of different age groups were compared with TDI. Results: Finally, 1 331 samples out of 2 059 were detected to contain thiocyanate. The detection rate was 65%. The average concentration of thiocyanate was 2.11 mg/kg, with a range of 0.10-16.20 mg/kg. The general population's consumption of thiocyanate by drinking liquid milk was 0.001 mg · kg(-1) · d(-1), which was lower than TDI. The P(95) of general population and consumers were 0.009 mg · kg(-1) · d(-1) and 0.020 mg·kg( -1)·d(-1) respectively, which were also lower than TDI. Mean exposures of population aged 3-6, 7-12, 13-17, 18-59 as well as elderly aged 60 and above were 0.007, 0.003, 0.002, 0.001 and 0.001 mg · kg(-1)·d(-1) respectively, which were all lower than TDI. Conclusion: The results suggested that the health risk of thiocyanate exposure by drinking liquid milk among Chinese population was at a low level. However, milk products for children deserve more concern.

[Molecular epidemiology of Japanese encephalitis viruses isolated in Yunnan province, 1977-2010].

Objective: To understand the genetic and molecular epidemiologic characteristics of 63 strains of Japanese encephalitis virus (JEV) isolated in Yunnan province, China during 1977-2010. Methods: Suckling mice were inoculated with viruses continuously and the viral nucleic acid were extracted from the brain-grinding supernatants of the infected and moribund mice, then the gene fragments of E region were amplified by RT-PCR. Bioinformatics (Clustal X, DNAstar, Mega 5.0 and other software) was used to analyze the nucleotide and deduced amino acid sequences and phylogenetic trees. Results: Yunnan strains of JEV could cause illness and deaths in suckling mice. The results of virus nucleic acid detection and sequencing indicated that nucleotide sequences of E gene of the 63 virus strains were obtained. Phylogenetic tree and homology analyses based on E genomes showed that 47 strains of the experimental virus belonged to genotype 1 (G-1) and 16 strains belonged to genotype 3 (G-3). The 47 isolates of G-1 were divided into 2 clades, of them, the earliest isolates of G-1 (M28, 1977 and BN82215, 1982) in Yunnan of China and the early isolates of G-1 (U70416, 1982; DQ084229, the year is unknown) in Thailand were in one clade, and the isolates of G-1 from 2007-2010 in Yunnan could be divided into 2 subgroups. The 16 isolates of G-3 from Yunnan were divided into 3 clades, among them, the isolates from 1970-1990s in Yunnan were in two clades, and the isolates from 2004 in Yunnan were in one clade. In addition, their main amino acid sites of antigenicity, pathogenic, virulence of both G-1 and G-3 had no significant change. Conclusion: JEV G-1 and G-3 co-circulated in Yunnan, and G-1 was predominant. The JEV strains isolated in different years and areas in Yunnan had different molecular epidemiologic characteristics and genetic diversity. The results of this study suggested that JEV G-1 might originate from Yunnan of China and adjacent Southeast Asia region.

Hypertonic saline activates CD4+ and CD8+ T-lymphocytes in the small intestine to alleviate intestinal ischemia-reperfusion injury.

OBJECTIVE: Intestinal ischemia-reperfusion injury (I/R) is a common syndrome encountered in clinic following intestinal surgery, strangulated hernia, and shock. Hypertonic saline has been shown to prevent inflammatory tissue damages caused by I/R and regulate immunologic disorders in peripheral blood. However, the immunoregulatory effects of hypertonic saline on the small intestine response to intestinal I/R have not been reported. MATERIALS AND METHODS: To investigate this, we created the intestinal I/R model by clamping the superior mesenteric artery in Sprague-Dawley rats. After 1 hour of ischemia, the vascular clamp was removed, and either normal saline (0.9% NaCl, NS group) or hypertonic saline (7.5% NaCl, HS group) was administered through the tail vein (6 ml/kg). The CD4(+) and CD(8+), primarily T-lymphocytes subpopulation yielded from the intestinal tissues, were determined by immunohistochemistry. RESULTS: A pro-inflammatory cytokine, tumor necrosis factor (TNF)-α, and nuclear factor kappa B (NF-κB), a critical transcription factor for the TNF-α gene, were measured in the intestinal and lung tissues with ELISA. HS induced an increase in CD4(+) and CD8(+) T cells in the jejunum and ileum compared with the NS group. The levels of TNF-α and NF-κB in the intestinal and lung tissues were significantly decreased in the HS group compared with those of the NS group. CONCLUSIONS: HS treatment may ameliorate the tissue damage induced by intestinal I/R. This protective effect is possibly due to its ability to activate the CD4(+) and CD8(+) T-lymphocytes cells in the intestinal tissues and inhibit the intestinal I/R-induced expression of pro-inflammatory cytokines.

A stress-induced cellular aging model with postnatal neural stem cells.

Aging refers to the physical and functional decline of the tissues over time that often leads to age-related degenerative diseases. Accumulating evidence implicates that the senescence of neural stem cells (NSCs) is of paramount importance to the aging of central neural system (CNS). However, exploration of the underlying molecular mechanisms has been hindered by the lack of proper aging models to allow the mechanistic examination within a reasonable time window. In the present study, we have utilized a hydroxyurea (HU) treatment protocol and effectively induced postnatal subventricle NSCs to undergo cellular senescence as determined by augmented senescence-associated-ß-galactosidase (SA-ß-gal) staining, decreased proliferation and differentiation capacity, increased G0/G1 cell cycle arrest, elevated reactive oxygen species (ROS) level and diminished apoptosis. These phenotypic changes were accompanied by a significant increase in p16, p21 and p53 expression, as well as a decreased expression of key proteins in various DNA repair pathways such as xrcc2, xrcc3 and ku70. Further proteomic analysis suggests that multiple pathways are involved in the HU-induced NSC senescence, including genes related to DNA damage and repair, mitochondrial dysfunction and the increase of ROS level. Intriguingly, compensatory mechanisms may have also been initiated to interfere with apoptotic signaling pathways and to minimize the cell death by downregulating Bcl2-associated X protein (BAX) expression. Taken together, we have successfully established a cellular model that will be of broad utilities to the molecular exploration of NSC senescence and aging.

PTEN regulates AMPA receptor-mediated cell viability in iPS-derived motor neurons.

Excitatory transmission in the brain is commonly mediated by the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors. In amyotrophic lateral sclerosis (ALS), AMPA receptors allow cytotoxic levels of calcium into neurons, contributing to motor neuron injury. We have previously shown that oculomotor neurons resistant to the disease process in ALS show reduced AMPA-mediated inward calcium currents compared with vulnerable spinal motor neurons. We have also shown that PTEN (phosphatase and tensin homolog deleted on chromosome 10) knockdown via siRNA promotes motor neuron survival in models of spinal muscular atrophy (SMA) and ALS. It has been reported that inhibition of PTEN attenuates the death of hippocampal neurons post injury by decreasing the effective translocation of the GluR2 subunit into the membrane. In addition, leptin can regulate AMPA receptor trafficking via PTEN inhibition. Thus, we speculate that manipulation of AMPA receptors by PTEN may represent a potential therapeutic strategy for neuroprotective intervention in ALS and other neurodegenerative disorders. To this end, the first step is to establish a fibroblast-iPS-motor neuron in vitro cell model to study AMPA receptor manipulation. Here we report that iPS-derived motor neurons from human fibroblasts express AMPA receptors. PTEN depletion decreases AMPA receptor expression and AMPA-mediated whole-cell currents, resulting in inhibition of AMPA-induced neuronal death in primary cultured and iPS-derived motor neurons. Taken together, our results imply that PTEN depletion may protect motor neurons by inhibition of excitatory transmission that represents a therapeutic strategy of potential benefit for the amelioration of excitotoxicity in ALS and other neurodegenerative disorders.

Combined evaluation of centromere protein H and Ki-67 as prognostic biomarker for patients with gastric carcinoma.

AIM: Centromere protein H (CENP-H) is one of the essential components of the human active kinetochore which close links with carcinogenesis. Its expression and clinical value of prognostic prediction for gastric cancer (GC) is unclear. METHODS: CENP-H and Ki-67 expressions in specimens from 166 patients with GC were determined by tissue microarrays and immunostaining. Their correlations between patients' clinicopathologic features and prognosis were explored. For mechanisms, quantitative CENP-H examination on gastric cancer tissue and cell lines was performed via real-time quantitative PCR and Western Blot. Its effect on Survivin expression and cell function was evaluated via CENP-H knocking down (SiRNA) or overexpression. RESULTS: Highly expression of CENP-H was found in 85 of 166 GC, showing a significant correlation with tumour size, depth of infiltration, lymph node metastasis, distant metastasis and UICC staging of gastric carcinoma (P < 0.05), as well as clinical prognosis (coefficient = 0.550, P < 0.001). Multivariate analysis revealed that combined CENP-H and Ki67 expression was a more valuable independent prognostic predictor for patients' survival (hazard ratio, 2.18; P = 0.0109). Furthermore, total mRNA and protein expression of CENP-H in GC tissue and cell lines were noticeably increased. Survivin expression and cell function including growth, proliferation and clonogenic ability could be inhibited by CENP-H siRNA or enhanced by overexpressing CENP-H. CONCLUSION: High expression of CENP-H in GC indicates poor prognosis and Survivin may mediate its procancer role. Combined evaluation of CENP-H and Ki-67 aids in predicting the clinical prognosis.

Detection of interleukin-33 in serum and carcinoma tissue from patients with hepatocellular carcinoma and its clinical implications.

OBJECTIVE: To study the clinical significance of intercellular interleukin (IL)-33 in hepatocellular carcinoma (HCC). METHODS: Using immunohistochemistry, this prospective study compared IL-33 protein levels in samples of HCC tissue and normal tissue adjacent to the tumour in 60 patients with HCC, and in normal liver tissue from six healthy controls. Interferon (IFN)-α, IFN-γ and IL-33 serum levels were also analysed by enzyme-linked immunosorbent assay in HCC 30 patients and 10 healthy controls. The level of IL-33 immunohistochemical staining was compared with the rate of lymph node metastasis in HCC patients. RESULTS: IL-33 was strongly positive in the cytoplasm of hepatocytes. The median percentage of IL-33-positive tissue was higher in HCC than in normal liver tissue samples (adjacent to the tumour or from controls). Serum IFN-α, IFN-γ and IL-33 levels were higher in pre- and postoperative samples from HCC patients than in control samples, and in patients with metastasis compared with those without metastasis. CONCLUSIONS: Increased IL-33 protein levels were observed in serum and liver tissue from HCC patients; IL-33 may be a useful biological marker for monitoring HCC growth and metastasis.

Tritium release during nuclear power operation in China.

Overviews were evaluated of tritium releases and related doses to the public from airborne and liquid effluents from nuclear power plants on the mainland of China before 2009. The differences between tritium releases from various nuclear power plants were also evaluated. The tritium releases are mainly from liquid pathways for pressurised water reactors, but tritium releases between airborne and liquid effluents are comparable for heavy water reactors. The airborne release from a heavy water reactor is obviously higher than that from a pressurised water reactor.

Biosorption of Methylene Blue onto spent corncob substrate: kinetics, equilibrium and thermodynamic studies.

This study focuses on the possible use of the spent corncob substrate (SCS), an agricultural waste used after the cultivation of white rot fungus Pleurotus ostreatus, to adsorb Methylene Blue (MB) from aqueous solutions. A batch adsorption study was carried out with variable solution pH, adsorption time, temperature and initial MB concentration. It was found that MB uptake was favorable at pH ranging from 4.0 to 12.0 and the equilibrium adsorption capacity can be reached promptly within about 180 min. The biosorption data were also calculated by the pseudo-second-order kinetic model and Langmuir isotherm model. Thermodynamic parameters show that the adsorption is a spontaneous and endothermic process. The study highlighted a new pathway to develop potential low-cost biosorbent for the removal of dye pollutants from wastewater.

Composition of flavonoids and phenolic acids in lychee (Litchi Chinensis Sonn.) Flower extracts and their antioxidant capacities estimated with human LDL, erythrocyte, and blood models.

Lychee (Litchi chinensis Sonn.) flower is a major nectar source in Taiwan. Antioxidant activities of acetone, ethanol, and hot-water extracts of the flower were estimated through three biochemical models: inhibition of Cu(2+) -induced oxidation of human low-density lipoprotein, scavenging ability of oxygen radicals in human blood, and inhibition of human erythrocyte hemolysis induced by peroxyl radicals. Composition and content of flavonoids and phenolic acids in these extracts were also determined by high-performance liquid chromatography. Results showed that antioxidant effects of all test models as well as contents of flavonoids and phenolic acids for the lychee flower extracts were in the order: acetone extract > ethanol extract > hot-water extract. Gentistic acid and epicatechin were the major phenolic acid and flavonoid in the extracts, respectively.

Dietary sodium deprivation evokes activation of brain regional neurons and down-regulation of angiotensin II type 1 receptor and angiotensin-convertion enzyme mRNA expression.

Previous studies have indicated that the renin-angiotensin-aldosterone system (RAAS) is implicated in the induction of sodium appetite in rats and that different dietary sodium intakes influence the mRNA expression of central and peripheral RAAS components. To determine whether dietary sodium deprivation activates regional brain neurons related to sodium appetite, and changes their gene expression of RAAS components of rats, the present study examined the c-Fos expression after chronic exposure to low sodium diet, and determined the relationship between plasma and brain angiotensin I (ANG I), angiotensin II (ANG II) and aldosterone (ALD) levels and the sodium ingestive behavior variations, as well as the effects of prolonged dietary sodium deprivation on ANG II type 1 (AT1) and ANG II type 2 (AT2) receptors and angiotensin-convertion enzyme (ACE) mRNA levels in the involved brain regions using the method of real-time polymerase chain reaction (PCR). Results showed that the Fos immunoreactivity (Fos-ir) expression in forebrain areas such as subfornical organ (SFO), paraventricular hypothalamic nuclei (PVN), supraoptic nucleus (SON) and organum vasculosum laminae terminalis (OVLT) all increased significantly and that the levels of ANG I, ANG II and ALD also increased in plasma and forebrain in rats fed with low sodium diet. In contrast, AT1, ACE mRNA in PVN, SON and OVLT decreased significantly in dietary sodium depleted rats, while AT2 mRNA expression did not change in the examined areas. These results suggest that many brain areas are activated by increased levels of plasma and/or brain ANG II and ALD, which underlies the elevated preference for hypertonic salt solution after prolonged exposure to low sodium diet, and that the regional AT1 and ACE mRNA are down-regulated after dietary sodium deprivation, which may be mediated by increased ANG II in plasma and/or brain tissue.