An effective inducer of dopaminergic neuron-like differentiation

Rat bone marrow-derived mesenchymal stem cells were cultured and passaged in vitro. After induction with basic fibroblast growth factor for 24 hours, passage 3 bone marrow-derived mesenchymal stem cells were additionally induced into dopaminergic neurons using three different combinations with basic fibroblast growth factor as follows： 20% Xiangdan injection; ali-trans retinoic acid ＋ glial-derived neurotrophic factor; or sonic hedgehog ＋ fibroblast growth factor 8. Results suggest that the bone marrow-derived mesenchymal stem cells showed typical neuronal morphological characteristics after induction. In particular, after treatment with sonic hedgehog ＋ fibroblast growth factor 8, the expressions of nestin, neuron-specific enolase, microtubule- associated protein 2, tyrosine hydroxylase and vesicular monoamine transporter-2 in cells were significantly increased. Moreover, the levels of catecholamines in the culture supernatant were significantly increased. These findings indicate that Xiangdan injection, all-trans retinoic acid ＋ glial-derived neurotrophic factor, and sonic hedgehog ＋ fibroblast growth factor 8 can all induce dopaminergic neuronal differentiation from bone marrow-derived mesenchymal stem cells. In particular, the efficiency of sonic hedgehog ＋ fibroblast growth factor 8 was highest.

Effects of Rat Cytomegalovirus on the Nervous System of the Early Rat Embryo

The purpose of the study was to investigate the impact of rat cytomegalovirus （RCMV） infection on the development of the nervous system in rat embryos, and to evaluate the involvement of Wnt signaling pathway key molecules and the downstream gene neurogenin 1 （Ngnl） in RCMV infected neural stem cells （NSCs）. Infection and control groups were established, each containing 20 pregnant Wistar rats. Rats in the infection group were inoculated with RCMV by intraperitoneal injection on the first day of pregnancy. Rat E20 embryos were taken to evaluate the teratogenic rate. NSCs were isolated from El3 embryos, and maintained in vitro. We found： 1） Poor fetal development was found in the infection group with low survival and high malformation rates. 2） The proliferation and differentiation of NSCs were affected. In the infection group, NSCs proliferated more slowly and had a lower neurosphere formation rate than the control. The differentiation ratio from NSCs to neurons and glial cells was significantly different from that of the control, showed by immunofluorescenee staining. 3） Ngnl mRNA expression and the nuclear p-catenin protein level were significantly lower than the control on day 2 when NSCs differentiated. 4） The Morris water maze test was performed on 4-week pups, and the infected rats were found worse in learning and memory ability. In a summary, RCMV infection caused abnormalities in the rat embryonic nervous system, significantly inhibited NSC proliferation and differentiation, and inhibited the expression of key molecules in the Wnt/β-catenin signaling pathway so as to affect NSCs differentiation. This may be an important mechanism by which RCMV causes embryonic nervous system abnormalities.

Tempo-spatial distribution of Ulva spp.micro-propagules in the Yellow Sea during and after green tide in 2019

Large-scale green tides occur frequently in summer in the Yellow Sea in recent decade.Micropropagules,providing“seeds”for the seaweeds,play an important role in the formation of green tide.We studied the distribution pattern and genetic composition of the Ulva micro-propagules in the Yellow Sea during and after the green tide in 2019.In April,a great amount of Ulva micro-propagules was detected in the Subei Shoal,with the average density of 908 inds./L,being similar to that of previous studies.U.prolifera was found out at a low percentage(4%),and 25%of them were positive when tested by the specific marker for the floating ecotype.The percentage of U.prolifera was obviously lower than that in the same season from 2009 to 2016.Therefore,the quantity of U.prolifera micro-propagules sharply decreased.Significant variation in composition of the micro-propagules in Subei radial sand ridges was revealed in the background of the alternation of macroalgal tides in the Yellow Sea in the latest years.During the green tide in June and July,Ulva micro-propagules were detected from some nearshore sites where the floating seaweeds distributed,and U.prolifera was the dominate species.In September,when the green tide ended,no Ulva micro-propagule was detected from the open sea area of the Yellow Sea.It is indicated that the green algae micro-propagules were unlikely to exist in the open water of the Yellow Sea for a long time according to the large-scale surveys.The mechanism of preserving micro-propagules in Subei radial sand ridges,and the destination of U.prolifera micro-propagules in the open sea area of the Yellow Sea after green tide deserves further study.

Daicong solution effects on brain ultrastructure in a rat model of Alzheimer's disease

BACKGROUND： Infusion of kainic acid into the basal nuclei induces neuronal excitotoxicity, degeneration and necrosis, resulting in disturbed learning and memory functions. OBJECTIVE： To explore the effects of different doses of traditional Chinese medicine Daicong solution on brain ultrastructure in a rat model of Alzheimer＇s disease. DESIGN, TIME AND SETTING： The randomized, controlled, cellular morphology experiment was performed at the Shandong Provincial Key Laboratory of Molecular Immunology of Weifang Medical University, China from October 2006 to March 2007. MATERIALS： Fifty healthy, Sprague Dawley rats, aged 22-months, were used to establish rat models of Alzheimer＇s disease. The Morris water maze was prepared at the Pharmacometrics Key Laboratory of Weifang Medical University in Shandong Province of China. Traditional Chinese medicine Daicong solution （crude drug 1 g/mL）, composed of radix ginseng, rehmannia dried rhizome, anemarrhenae and radix astragali, was produced by the Department of Pharmacy of Hospital Affiliated to Weifang Medical University. Kainic acid was provided by Professor Xiuyan Li from Weifang Medical University. METHODS： A total of 40 model rats were equally and randomly divided into four groups： dementia model, low-dose Daicong solution （5 g/kg/d）, moderate-dose Daicong solution （10 g/kg/d）, and high-dose Daicong solution （20 g/kg/d）. An additional 10 healthy rats served as the normal control group. Rats in the dementia model and normal control groups received saline （10 mL/kg/d）. MAIN OUTCOME MEASURES： Neural cell ultrastructure was observed utilizing electron microscopy after 1 month of respective treatments. RESULTS： Compared with the normal control group, electron density and the number of ribosomes were significantly reduced in neuronal cytoplasm, and many lipofuscin grains and vacuole-like changes were observed in mitochondria in the dementia model group. In addition, nuclear chromatin presented with different sizes of plaque-shaped degenerative pathological changes. In the Alzheimer＇s disease rat model, neurons and neuroepithelial cells recovered to normal conditions following treatment with moderate- and high-dose Daicong solution. In the low-dose Daicong group, the condition was slightly improved, but the cytopathic effects were still significant. CONCLUSION： Daicong solution significantly improved neuronal and neuroepithelial pathological ultrastructure in a rat model of Alzheimer＇s disease.

Provenance of Late Mesozoic Strata and Tectonic Implications for the Southwestern Ordos Basin,North China:Evidence from Detrital Zircon U-Pb Geochronology and Hf Isotopes

In order to determine the provenance and variation characteristics of sandstone-type uranium deposits located in the southwest Ordos Basin,U-Pb geochronology and Hf isotope analyses were conducted on detrital zircons from the Late Mesozoic strata of the SD01 well in the Zhenyuan area.The detrital zircon U-Pb ages of four samples exhibited four main peaks at 250–330,420–500,1720–2000,and 2340–2580 Ma,with a small number of zircons dated at 770–1100 Ma.The detrital zircon age spectrum and further restriction provided by the in-situ Hf isotopic data suggest that the provenance of each stratum was mainly derived from the crystalline basement rock series(Khondalites,intermediate-acidic intrusive rocks,and metamorphic rocks)of the Alxa Block to the northwest and the Yinshan Block to the north,with minor amounts of Caledonian magmatic rocks and Jingning Period rocks from the western part of the northern Qilian orogenic belt to the west and the northern Qinling orogenic belt to the south.The provenance of the sandbody has not changed significantly and is of the Middle Jurassic–Early Cretaceous.The clear variations in the zircon ages of the samples from the Zhiluo and Anding formations were likely influenced by climate change during the Middle–Late Jurassic.The Triassic zircon age(<250 Ma)first appeared in Early Cretaceous strata,suggesting that tectonic activity was relatively strong in the northern Qinling orogenic belt during the Late Jurassic and produced extensive outcrops of Indo-Chinese granite,which were a source of basin sediments.

Quantitative analysis of microplastics in coastal tidal-flat reclamation in Dongtai,China

Coastal tidal flats have received considerable attention in recent years,as they provide a direct channel for the discharge of terrestrial microplastics into the ocean.Land reclamation is occurring increasingly frequently in coastal tidal-flats;however,the environmental impacts of these activities remain unclear.Therefore,this pioneering study assessed the microplastic emission characteristics of reclamation geotextiles and performed a risk assessment accordingly.Morphological characterization of geotextile samples collected from five sites in Dongtai,China,provided evidence of sedimentary weathering.Based on several assumptions,the average abundance of microplastics in soil covered by geotextiles was estimated to reach 349137 particles/kg dry weight,with the total microplastic load in the reclaimed area estimated to be 20.678.06 t.Compared with previous studies,this research demonstrates that coastal reclamation areas store a high concentration of microplastics,aggravating marine microplastic pollution.Moreover,conditional fragmentation model results revealed that the weathering and distribution characteristics of soil microplastics in coastal tidal-flat areas exhibit spatial heterogeneity,being more easily affected by natural factors(such as tides)than those in inland areas.As a result of tides,the annual discharge of geotextile-originating microplastics from the studied areas into the ocean was approximately 2465.52960.77 t.These findings prove that the risks posed by engineering-microplastics are significant,indicating that further investigations are required on the precise laws of transfer and migration,as well as the toxicity mechanisms,in order to improve analytical techniques and policies in this field.

Enamel coating for protection of the 316 stainless steel against tribo-corrosion in molten zinc alloy at 460℃

Hot-dip galvanizing provides excellent corrosion and wear resistance for steels.However,the equipment itself,such as the steel roller,immerged in corrosive molten zinc suffers serious material loss during steel's production.Its protection has become the main technique problem in modern galvanizing line.In this study,an enamel coating was designed and prepared.Its tribo-corrosion in molten zinc alloy(Zn-0.2 wt%Al)at 460℃was investigated in comparison with the traditional WC-12 Co composite coating and the 316 stainless steel.Results indicate that the steel suffers serious material damage.Various corrosion products of Fe_(2) Al_(5) Znx form at the worn surface and the wear scar has reached 200μm deep after merely 5 h tribo-corrosion.Though the two coatings provide an improved tribo-corrosion resistance,for the WC-12 Co coating,its chemical reaction with the molten zinc increases brittleness and promotes cracking.The synergistic wear and corrosion cause its degradation.The enamel coating performs better during tribo-corrosion.It is chemically stable in molten zinc thus able to provide high corrosion resistance.In addition,the amorphous[Si04]network and the self-lubricating CaF_(2) crystallite help it to build up an intact amorphous glaze layer readily at surface on sliding,leading to a reduced wear loss.During the whole tribo-corrosion process,the enamel coating is completely free of cracking,and the Zn penetration is inhibited.