152 research outputs found
Effects of Xinwei granule on expression levels of cyclin D1 and its upstream genes in gastric intraepithelial neoplasia tissues
Purpose: To explore the effects of Xinwei granule (XWG) on low-grade gastric intraepithelial neoplasia (LGIN) and the underlying mechanisms.
Methods: To establish LGIN model, Wistar rats were treated with N-methyl-N'-nitrosoguanidine for 3 months. LGIN model rats were randomly grouped into five groups (n = 15), viz, negative control (NC), normal saline (NS) group, Xinwei granule (XWG) group, Weifuchun tablet (WFCT) group, and vatacoenayme tablet (VT) group. Normal rats (n = 17) served as negative control. Histological evaluation of gastric mucosa was undertaken using hematoxylin and eosin staining. Quantitative realtime polymerase chain reaction (qRT-PCR), western blot, and immunohistochemical assays were performed to determine mRNA expressions, protein expression, and the distribution of cyclin D1, kruppel-like factor 4 (KLF4), and p21-WAF1-CIP1, respectively.
Results: Compared with LGIN group, the body weight of the rats increased in XWG, WFCT, and VT groups. The pathological characteristics of LGIN group were alleviated by XWG, WFCT and VT treatments. The positive expression of cyclin D1 was enhanced in LGIN group, but reduced in XWG, WFCT and VT groups. The expression levels of KLF4 and p21-WAF1-CIP1, upstream regulators of cyclin D1 reduced in LGIN groups. However, administration of XWG, WFCT and VT strengthened the expressions of KLF4 and p21-WAF1-CIP1. More importantly, the protective effects of XWG against LGIN were superior to those of WFCT and VT.
Conclusion: Xinwei granules alleviate LGIN in vivo by inhibiting cyclin D1 expression and enhancing KLF4 and p21-WAF1-CIP1 expression
Study of Peeling of Single Crystal Silicon by Intense Pulsed Ion Beam
The surface peeling process induced by intense
pulsed ion beam (IPIB) irradiation was studied.
Single crystal silicon specimens were treated by
IPIB with accelerating voltage of 350 kV current
density of 130 A/cm2. It is observed that
under smaller numbers of IPIB shots, the surface
may undergo obvious melting and evaporation..
Study of Peeling of Single Crystal Silicon by Intense Pulsed Ion Beam
The surface peeling process induced by intense
pulsed ion beam (IPIB) irradiation was studied.
Single crystal silicon specimens were treated by
IPIB with accelerating voltage of 350 kV current
density of 130 A/cm2. It is observed that
under smaller numbers of IPIB shots, the surface
may undergo obvious melting and evaporation..
The impact of new digital infrastructure on green total factor productivity
As a new engine driving economic development, new digital infrastructure plays a significant role in enhancing green total factor productivity. Based on 2011–2020 panel data covering 30 Chinese provinces, this study empirically investigates the effects and mechanisms of new digital infrastructure on green total factor productivity. The results show that new digital infrastructure can significantly improve regional green total factor productivity, and this conclusion remains valid after a series of robustness tests and regressions of instrumental variables. Further mechanism research shows that new digital infrastructure indirectly promotes the growth of green total factor productivity by improving capital misallocation and driving technological innovation, while there is no mediating mechanism of labor misallocation. In addition, there is significant heterogeneity in the impact of new digital infrastructure on green total factor productivity. Especially during periods of high government attention, in the eastern regions, and in areas with higher levels of human capital, the positive incentive effect of new digital infrastructure is more significant. This study provides empirical evidence and policy references for promoting and amplifying the green growth effects of new digital infrastructure
Study on Ablation Products of Zinc by Intense Pulsed Ion Beam Irradiation
As a kind of flash heat source, intense pulse ion
beam can be used for material surface modification.
The ablation effect has important influence
on interaction between IPIB and material. Therefore,
the understanding of ablation mechanism is
of great significance to IPIB application..
Efficient model-based bioequivalence testing
The classical approach to analyze pharmacokinetic (PK) data in bioequivalence studies
aiming to compare two different formulations is to perform noncompartmental analysis
(NCA) followed by two one-sided tests (TOST). In this regard the PK parameters AUC
and Cmax are obtained for both treatment groups and their geometric mean ratios are
considered. According to current guidelines by the U.S. Food and Drug Administration
and the European Medicines Agency the formulations are deemed to be similar if the
90%- confidence interval for these ratios falls between 0:8 and 1:25. As NCA is not a
reliable approach in case of sparse designs, a model-based alternative has already been
proposed for the estimation of AUC and Cmax using non-linear mixed effects models.
Here we propose another test than the TOST, called BOT, and evaluate it through a
simulation study both for NCA and model-based approaches. For products with high
variability on PK parameters, this method appears to have closer type I errors to the
conventionally accepted significance level of 0:05, suggesting its potential use in situations
where conventional bioequivalence analysis is not applicable
Prediction of high-Tc superconductivity in ternary lanthanum borohydrides
The study of superconductivity in compressed hydrides is of great interest
due to measurements of high critical temperatures (Tc) in the vicinity of room
temperature, beginning with the observations of LaH10 at 170-190 GPa. However,
the pressures required for synthesis of these high Tc superconducting hydrides
currently remain extremely high. Here we show the investigation of crystal
structures and superconductivity in the La-B-H system under pressure with
particle-swarm intelligence structure searches methods in combination with
first-principles calculations. Structures with six stoichiometries, LaBH,
LaBH3, LaBH4, LaBH6, LaBH7 and LaBH8, were predicted to become stable under
pressure. Remarkably, the hydrogen atoms in LaBH8 were found to bond with B
atoms in a manner that is similar to that in H3S. Lattice dynamics calculations
indicate that LaBH7 and LaBH8 become dynamically stable at pressures as low as
109.2 and 48.3 GPa, respectively. Moreover, the two phases were predicted to be
superconducting with a critical temperature (Tc) of 93 K and 156 K at 110 GPa
and 55 GPa, respectively. Our results provide guidance for future experiments
targeting new hydride superconductors with both low synthesis pressures and
high Tc.Comment: 16 pages, 5 figures
Study of the intense pulsed electron beam energy spectrum from BIPPAB-450
Intense pulsed particle beams have been
widely used and studied as an effective method
for material surface modification in the past
several decades. Beihang Intense Pulsed PArticle
Beams 450 accelerator (BIPPAB-450) can
produce Intense Pulsed Ion Beams (IPIB) and
Electron Beams (IPEB) in two modes with different
Magnetically Insulated Diodes (MID).
For IPEB, the pulse duration, accelerating voltage,
total beam current are 100ns, up to 450keV
and 3kA, respectively..
Engineering human ventricular heart muscles based on a highly efficient system for purification of human pluripotent stem cell-derived ventricular cardiomyocytes
Background
Most infarctions occur in the left anterior descending coronary artery and cause myocardium damage of the left ventricle. Although current pluripotent stem cells (PSCs) and directed cardiac differentiation techniques are able to generate fetal-like human cardiomyocytes, isolation of pure ventricular cardiomyocytes has been challenging. For repairing ventricular damage, we aimed to establish a highly efficient purification system to obtain homogeneous ventricular cardiomyocytes and prepare engineered human ventricular heart muscles in a dish.
Methods
The purification system used TALEN-mediated genomic editing techniques to insert the neomycin or EGFP selection marker directly after the myosin light chain 2 (MYL2) locus in human pluripotent stem cells. Purified early ventricular cardiomyocytes were estimated by immunofluorescence, fluorescence-activated cell sorting, quantitative PCR, microelectrode array, and patch clamp. In subsequent experiments, the mixture of mature MYL2-positive ventricular cardiomyocytes and mesenchymal cells were cocultured with decellularized natural heart matrix. Histological and electrophysiology analyses of the formed tissues were performed 2 weeks later.
Results
Human ventricular cardiomyocytes were efficiently isolated based on the purification system using G418 or flow cytometry selection. When combined with the decellularized natural heart matrix as the scaffold, functional human ventricular heart muscles were prepared in a dish.
Conclusions
These engineered human ventricular muscles can be great tools for regenerative therapy of human ventricular damage as well as drug screening and ventricular-specific disease modeling in the future.
Electronic supplementary material
The online version of this article (doi:10.1186/s13287-017-0651-x) contains supplementary material, which is available to authorized users
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