Late Mesozoic magmatism in the East Qinling Orogen, China and its tectonic implications

The Qinling Orogen in Central China records the history of a complex geological evolution and tectonic transition from compression to extension during the Late Mesozoic,with concomitant voluminous granitoids formation.In this study,we present results from petrological,geochemical,zircon U-Pb-Lu-Hf isotopic studies on the Lengshui felsic dykes from Luanchuan region in the East Qinling Orogen.We also compile published geochronological,geochemical,and Hf isotopic data from Luanchuan region and present zircon Hf isotopic contour maps.The newly obtained age data yield two group of ages at w145 Ma and 140 Ma for two granite porphyries from the Lengshui felsic dykes,with the w145 Ma interpreted as response to the peak of magmatism in the region,and the w140 Ma as the timing of formation of the felsic dykes.The corresponding Hf isotopic data of the granite porphyries display negative εHf(t) values of e16.67 to e4.61,and Hf crustal model ages (TDM^C) of 2255e1490 Ma,indicating magma sourced from the melting of Paleo- to Mesoproterozoic crustal materials.The compiled age data display two major magmatic pulses at 160e130 Ma and 111e108 Ma with magmatic quiescence in between,and the zircon Hf isotopic data display εHf(t) values ranging from e41.9 to 2.1 and TDM^C values of 3387e1033 Ma,suggesting mixed crustal and mantle-derived components in the magma source,and correspond to multiple tectonic events during the Late Mesozoic.The Luanchuan granitoids are identified as I-type granites and most of these are highly fractionated granites,involving magma mixing and mingling and crystal fractionation.The tectonic setting in the region transformed from the Late Jurassic syn-collision setting to Early Cretaceous within-plate setting,with EeW extension in the Early Cretaceous.This extension is correlated with the NeS trending post-collisional extension between the North China Craton and Yangtze Craton as well as the EeW trending back-arc extension triggered by the westward Paleo-Pacific Plate subduction,eventually leading to lithospheric thinning,asthenospheric upwelling,mafic magma underplating,and crustal melting in the East Qinling Orogen.

Is 1.28 parts per million biomarker specific for neural progenitor cells?

Nuclear magnetic resonance-visible mobile lipid, at 1.28 parts per million （ppm）, is thought to be due to mobile lipid droplets formed in cells and has been considered unique for neural progenitor cells. However, this idea remains controversial. The present study examined the 1.28 ppm biomarker in other stem cells and non-stem cells, and explored the relationship between 1.28 ppm biomarker and mobile lipid droplets. 1H nuclear magnetic resonance spectroscopy of EC109 cells, mesenchymal stem cells （MSCs） and adipogenic cells differentiated from MSCs was performed. Results show that 1.28 ppm biomarker was observed in human MSCs, but was absent from EC109 cells. Following adipogenic differentiation induced for 2 weeks, the 1.28 ppm biomarker climbed remarkably, with mobile lipid droplet generation, suggesting that the 1.28 ppm biomarker is not specific for neural progenitor cells because it is also observed in MSCs and adipogenic-induced differentiated cells. Moreover, it is possible to monitor MSCs differentiation following cell transplantation, using 1.28 ppm biomarker changes.

Quantitative analysis of glutamate compounds in the swine brain following central analgesics nasal spray using proton magnetic resonance spectroscopy and linear combination model

BACKGROUND： In localized brain proton magnetic resonance spectroscopy （^1H-MRS）, metabolite levels are often expressed as ratios, rather than absolute concentrations. Frequently, the denominator is creatine, which is assumed to be stable in normal, as well as many pathological, states. However, in vivo creatine levels do not remain constant. Therefore, absolute metabolite measurements, which provide the precise concentrations of certain chemical compounds, are superior to metabolite ratios for determining pathological and evolutional changes. OBJECTIVE： To investigate the feasibility of quantification analysis of brain metabolite changes caused by central analgesics nasal spray using the ^1H-MRS and linear combination model （LCModel） methods. DESIGN, TIME AND SETTING： This neuroimaging, observational, animal study was performed at the Laboratory of the Department of Medical Imaging, Second Affiliated Hospital, Medical College, Shantou University, China from July to December 2007. MATERIALS： Butorphanol tartrate nasal spray, as a mixed agonist-antagonist opioid analgesic, was purchased from Shanghai Hengrui Pharmacy, China. A General Electric Signa 1.5T System （General Electric Medical Systems, Milwaukee, WI, USA） and LCModel software （Stephen Provencher, Oakville, Ontario, Canada） were used in this study. METHODS： MRS images were acquired in ten healthy swine aged 2 weeks using single-voxel point-resolved spectroscopic sequence. A region of interest （2 cm × 2 cm × 2 cm） was placed in the image centers of maximum brain parenchyma. Repeated MRS scanning was performed 15-20 minutes after intranasal administration of 1 mg of butorphanol tartrate. Three settings of repetition time/echo time were selected before and after nasal spray administration 3 000 ms/30 ms,1 500 ms/30 ms, and 3 000 ms/50 ms. Metabolite concentrations were estimated by LCModel software. MAIN OUTCOME MEASURES： ^1H-MRS spectra was obtained using various repetition time/echo time settings. Concentrations of glutamate compounds （glutamate ＋ glutamine）, N-acetyl aspartate, and choline were detected in swine brain prior to and following nasal spray treatment. RESULTS： The glutamate compounds curve was consistent with original spectra, when a repetition time/echo time of 3 000 ms/30 ms was adopted. Concentrations of glutamate compounds, N-acetyl aspartate, and choline decreased following administration. The most significant reduction was observed in glutamate compound concentrations from （9.28 ± 0.54） mmol/kg to （7.28 ± 0.54） mmol/kg （P 〈 0.05）. CONCLUSION： ^1H-MRS and LCModel software were effectively utilized to quantitatively analyze and measure brain metabolites. Glutamate compounds might be an important neurotransmitter in central analgesia.

A Novel Method for the Prenatal Diagnosis of Cleft Palate Based on Amniotic Fluid Metabolites

Background and purpose The prenatal diagnosis of cleft palate is an important component of sequential therapy,but the relevant diagnostic methods are still limited.We aimed here,to explore the possibility of an early prenatal diagnosis of cleft palate by assessing metabolites in pregnant mice.Methods Twenty-four inseminated females were randomly divided into retinoic acid(RA)-treated(treated with retinoic acid at 10.5 gestation days)and control groups.The metabolites of the embryonic palatal tissue,maternal amniotic fluid,and serum were characterized using 9.4T magnetic resonance spectroscopy in vitro.Then,a predictive model was established through the principal component analysis(PCA),and the correlations between the metabolites of amniotic fluid and palatal tissue were explored using orthogonal-2 partial least squares(O2-PLS).Results The incidences of cleft palate were 100%and 0%in the RA-treated and control groups,respectively.A predictive PCA model with a high specificity and sensitivity was established for the early prenatal diagnosis of isolated cleft palate using amniotic fluid metabolic data.Between RA-treated and control mice,we found that two metabolites in the amniotic fluid and palatal tissue were correlated.Creatinine showed the same trend in the palatal tissue and amniotic fluid,while choline showed opposite trends in the two tissues.However,the data for serum metabolites could not be used to establish a prediction model.Conclusion This study indicates that assessing the metabolites of amniotic fluid is a potential approach for the prenatal diagnosis of isolated cleft palate.