Preparation and fluorescence characterization of monodisperse core-shell structure SiO2 @SiO2 :Tb(1,2-BDC)3 phen microspheres by a sol-seed method.

The SiO2 @SiO2 :Tb(1,2-BDC)3 phen microspheres with monodispersed core-shell structure, are kind of fluorescent particles, which are prepared by a seeded growth method under the catalysis of glacial acetic acid (1,2-BDC, 1,2-benzenedicarboxylic acid; phen, 1,10-phenanthroline). Firstly, silica seed was fabricated by the hydrolysis of ethyl orthosilicate, and the Tb(1,2-BDC)3 phen was prepared by using 1,2-BDC and phen. Then, a thin mesoporous silica shell doped with Tb(1,2-BDC)3 phen was grown on the prepared monodisperse silica colloids. The prepared phosphor was analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, thermogravimetric and fluorescence spectroscopy. The experimental results showed that the diameter of the SiO2 @SiO2 :Tb((1,2-BDC)3 phen microsphere was about 200 nm with a typical core-shell structure, among which the diameter of the silica core was 180 nm, and that of the mesoporous silicon shell doped with terbium complex was about 10 nm. The fluorescence intensity of SiO2 @SiO2 :Tb((1,2-BDC)3 phen microsphere is nearly three times higher than that of Tb((1,2-BDC)3 phen complexes. The prepared microspheres could be widely used in bio-imaging, optoelectronic appliances and medical diagnosis.

A comparative-descriptive analysis of clinical characteristics in 2019-coronavirus-infected children and adults.

Acute respiratory disease caused by 2019 novel coronavirus (2019-nCoV) has rapidly spread throughout China. Children and adults show a different clinical course. The purpose of the current study is to comparatively analyze the clinical characteristics of 2019-nCoV infection in children and adults and to explore the possible causes for the discrepancies present. The medical records of 25 adults and 7 children confirmed cases of 2019-2019-nCoV acute respiratory diseases were reviewed retrospectively. All children were family clusters. The total adult patients were differentiated into the local residents of Wuhan, a history of travel to Wuhan and direct contact with people from Wuhan. The numbers were 14 (56%), 10 (40%), and 1 (4%), respectively. The median incubation period of children and adults was 5 days (ranged, 3-12 days) and 4 days (ranged, 2-12 days), respectively. Diarrhoea and/or vomiting (57.1%) were demic by World Health Organiza more common in children, whereas for adults it was myalgia or fatigue (52%). On admission, the percentage of children having pneumonia (5%, 71.4%) was roughly the same as adults (20%, 80%). A total of 20% of adults had leucopoenia, but leukocytosis was more frequently in children (28.6%, P=.014). A higher number of children had elevated creatine kinase isoenzyme (57.1% vs 4%, P=.004). Antiviral therapy was given to all adult patients but to none of the children. In summary, knowledge of these differences between children and adults will not only be helpful for the clinical diagnosis of 2019-nCoV disease, but also for a future discussion on age-specific coronavirus infection.

Improving Ion Selectivity of 1,4,7-Triazacyclononane-Based Receptor by Zinc Coordination: "Turn-On" Chemosensor for Br- and Fe3+ Ions.

Ion-responsive probes have gathered significant attention because of health and environmental factors, but there are few reports on the "turn-on" mechanism of Fe3+ and sensitive detection of Br- by fluorescence measurement. Herein, a green luminescence material, N-5-acetyl-2-hydroxy-benzamide-1,4,7-triazacyclononane (btacn), was successfully synthesized for the first time and comprehensively characterized. As expected, btacn exhibits high sensitive, but nonspecific, extensive interaction with Cu2+, Co2+, Zn2+, Mn2+, and Fe3+ ions. Therefore, to improve the specificity of the probe, we tried to synthesize transition metal complexes of btacn, but all failed except Zn(btacn)Cl2. In addition, the preformed complex, Zn(btacn)Cl2, was used as a special "turn-on" chemosensor for detecting trace amounts of Br- and Fe3+. The electrostatic interaction with Fe3+ and the hydrogen bond of PhO-H···Br- leads to obvious changes in the electronic cloud of Zn(btacn)Cl2, which are reflected in different spectral responses.

[Research progress in root rot diseases of Chinese herbal medicine and control strategy by antagonistic microorganisms].

In recent years, root rot diseases of Chinese herbal medicine have been posing grave threat to the development of the traditional Chinese medicine industry. This article presents a review on the occurring situation of the root rot disease, including the occurrence of the disease, the diversity of the pathogens, the regional difference in dominant pathogens,and the complexity of symptoms and a survey of the progress in bio-control of the disease using antagonistic microorganisms. The paper also discusses the existing problems and future prospects in the research.

First report of haemosporidia and associated risk factors in red junglefowl (Gallus gallus) in China.

BACKGROUND: Avian haemosporidia infect both domestic and wild birds, causing anemia, acute tissue degeneration, and depopulation in wild birds. Poultry and wild birds have been reported as common reservoirs of haemosporidia, but limited information is available for red junglefowl (Gallus gallus) in China. The present study investigated the prevalence and molecular characterization of haemosporidia in red junglefowl. METHODS: Blood samples were collected from 234 red junglefowl from Jinghong City of Yunnan Province, and genomic DNA was extracted from these samples. The prevalence of haemosporidia was determined by nested PCR targeting the mitochondrial cytochrome b (cytb) gene. Molecular characterization was investigated based on phylogenetic analysis of cytb sequences, and associated risk factors were analyzed using the Chi-square (χ2) test. RESULTS: The overall prevalence of haemosporidia was 74.8% (175/234), and three species were identified, namely Haemoproteus enucleator, Leucocytozoon californicus, and Plasmodium juxtanucleare. The prevalence of haemosporidia in adult fowl (81.1%, 107/132) was significantly higher (χ2 = 6.32, df = 1, P = 0.012) than that in juveniles (66.7%, 68/102). Three novel haemosporidian lineages were revealed. CONCLUSIONS: This study examined the prevalence and identified species of avian haemosporidians in red junglefowl, providing new information on the molecular epidemiology and geographical distribution of haemosporidian parasites. Our results indicated high prevalence and diverse species distribution of these haemosporidians in red junglefowl. To the best of our knowledge, this is the first record of haemosporidian infection in red junglefowl in China.

A review on the structure and pharmacological activity of phenylethanoid glycosides.

Phenylethanoid glycosides (PhGs) are compounds made of phenylethyl alcohol, caffeic acid and glycosyl moieties. The first published references about phenylethanoid glycosides concerned the isolation of echinacoside from Echinaceu ungustifolia (Asteraceae) in 1950 and verbascoside from Verbascum sinuatum (Scrophulariaceae) in 1963. Over the past 60 years, many compounds with these structural characteristics have been isolated from natural sources, and most of these compounds possess significant bioactivities, including antibacterial, antitumor, antiviral, anti-inflammatory, neuro-protective, antioxidant, hepatoprotective, and immunomodulatory activities, among others. In this review, we will summarize the phenylethanoid glycosides described in recent papers and list all the compounds that have been isolated over the past few decades. We will also attempt to present and assess recent studies about the separation, extraction, determination, and pharmacological activity of the excellent natural components, phenylethanoid glycosides.

[Expression and immunological characterization of the epitopes in tartary buckwheat allergen].

AIM: To determine the most important region in tartary buckwheat allergen. METHODS: The gene of epitopes was amplified by PCR using the primers designed according to TBa cDNA. Four expression vectors containing the gene of epitopes were constructed, and then transformed into the E.coli BL21(DE3) host cells. The expression products were purified by Ni(2+);-NTA agarose affinity chromatography column and indirect ELISA, inhibition ELISA and Dot blot was performed using sera from allergenic patients. RESULTS: The purified proteins were obtained and the immunological results showed that E1 exhibite stronger IgE binding to patient's serum than the other epitopes. CONCLUSION: E1 is probably the most important region in tartary buckwheat allergen binding to buckwheat allergic sera IgE.

[Effect of genistein on hepatic stellate cell proliferation and lipid peroxidation in vitro].

OBJECTIVE: To investigate the effect of genistein on the proliferation and lipid peroxidation of hepatic stellate cells (HSC) in vitro and its the protective effect against hepatic fibrosis. METHODS: Rat hepatic stellate cells (HSC-T6 cells) were divided into 3 groups and incubated in the presence of 0.1 mol/L hydrogen dioxide followed by washing with PBS for 3 times. Genistein at different concentrations was added into the cell culture meclia, and after 48 h of incubation, the cell proliferation was assessed with MTT assay and the levels of superoxide dismutase (SOD), malonaldehyde (MDA), glutathione (GSH) and glutathione peroxidase (GSH-PX) in the supernatant of the cell culture were measured. RESULTS: Genistein at different concentrations inhibited the cell proliferation, showing a dose-effect relationship. Genistein significantly decreased the production of intracellular MDA and GSH and increased SOD and GSH PX activity. CONCLUSION: Genistein can prevent the formation of hepatic fibrosis probably by decreasing HSC proliferation and lipid peroxidation.