•Established a three-dimensional pressure vessel model for marine reactors.•The introduction of ocean conditions and core porous medium model is completed by momentum source based on UDF.•Various ...ocean motion conditions are considered.•The interaction between the local flow field and the flow distribution at the core inlet of the pressure vessel with a spherical flow distributor.•Vortex will affect the flow rate of special fuel assemblies inlet.•Nonlinear motions can promote uniform distribution of core inlet flow rate.
The high consumption of traditional energy is difficult to support the development of marine resources. Floating Nuclear Power Plant (FNPP) can be used for energy supply due to their advantages such as high power and low cost. Considering that ocean conditions can seriously cause flow fluctuations at the core inlet, this paper establishes a Reactor Pressure Vessel (RPV) model that includes a porous medium core model for numerical analysis. The momentum source is added to the control equation to achieve introduction of ocean conditions, which solves the problem of plane data errors in dynamic mesh method. Therefore, the flow distribution at the core inlet can be obtained under ocean conditions and the local flow characteristics in the lower chamber can be comprehensively observed. The results shown that nonlinear motion can promote more uniform flow distribution at the core inlet, enhancement of the additional force in motion can effectively suppress vortices. In the early stages of motion, rolling motion will cause inlet flow of most fuel assemblies to be too high or too low, it is necessary to adjust the reactor power output accordingly. In linear motion, surging motion does not improve the non-uniformity of flow distribution at the core inlet, but it can increase the stability of coolant flow in the lower chamber and reduces the number of vortices. Heaving motion has very little impact on flow distribution at the core inlet due to it is consistent with the mainstream direction. Coupled motion can enhance the uniformity of core inlet flow compared to single degree of freedom motion and more attention should be paid to adjusting initial reactor power output.
It is becoming increasingly evident that key mechanisms of mesenchymal stem cell (MSC) efficacy appear to associate with paracrine activities, and the delivery of cargos through extracellular ...vesicles (EVs) controls the mechanistic actions of MSCs. Thus, this study clarified a possible mechanism by which EV-encapsulated NEAT1 from adipose-derived mesenchymal stem cells (ADSCs) might mediate gemcitabine resistance in pancreatic cancer (PCa). Microarray profile suggested a differentially expressed lncRNA NEAT1 in PCa, and we determined its expression in PCa cells. NEAT1 was found to be upregulated in PCa. The binding affinity among NEAT1, miR-491-5p, and Snail was identified through bioinformatic analysis and experimental validation. NEAT1 competitively bound to miR-491-5p to elevate Snail expression and diminish SOCS3 expression. PCa cells were cocultured with EVs extracted from ADSCs, followed by assessment of malignant phenotypes, tumorigenesis, and gemcitabine resistance of PCa cells using gain- or loss-of-function experiments. ADSC-derived EVs carrying NEAT1 promoted PCa cell proliferation, migration, and gemcitabine resistance in vitro and enhanced tumorigenicity in vivo by inhibiting miR-491-5p and SOCS3 and upregulating Snail. Collectively, the findings from our study found a new potential strategy for gemcitabine resistance in PCa by illustrating the mechanistic insights of oncogenic ADSC-derived EVs-loaded NEAT1 via regulating the miR-491-5p/Snail/SOCS3 axis.
We have developed a sensor for the temperature measurement in the test section after the combustion chamber of an aero engine model by using direct absorption spectroscopy. Five distributed feedback ...diode lasers at near 1392, 1393, 1339, 1343, and 1469 nm are utilized as the light sources to detect H2O absorptions to improve the precision of temperature measurement combining with the Boltzmann plot method and the polynomial‐based spectral fitting model. The sensor shows a good performance in terms of its temperature measurement accuracy under high temperature of 673–1373 K and high pressure of 100–600 kPa condition in a tube furnace, which was lower than 4%. Moreover, three‐dimensional temperature distributions have been reconstructed via applying algebraic reconstruction technique at the test section after the combustion chamber of an aero engine model. The single‐point position temperature extracted from the algebraic reconstruction technique agrees well with that measured from the coherent anti‐stokes Raman scattering technique, where the relative error is within 5%. All the above results prove the reliability of our developed temperature sensor.
Background:
Post-stroke cognitive impairment (PSCI) is commonest clinical disorder in which peripheral cholinergic activity is important. Oleuropein (OLP) is polyphenol is present in olive oil. Here ...we evaluated the effect of OLP in cognitive dysfunction rats in post cerebral stroke model.
Methods:
The post cerebral stroke cognitive dysfunction PSD rat model was created by occlusion of transient middle cerebral artery. The rats were divided into 6 groups named, Sham + Vehicle, Sham + OLP (50 mg/kg), PSD rats + Vehicle, PSD rats + OLP (20, 50 or 100 mg/kg). The spatial learning was assessed by Morris water maze (MWM). The expression of choline acetyltransferase (ChAT), acetylcholine (ACH), extent of histone acetylation and phosphorylation of cAMP response element-binding protein (CREB) were evaluated by Western blot assay and immunofluorescence staining.
Results:
Treatment of OLP at various doses showed higher number of spontaneous and rewarded alterations and lesser percentage bias compared to vehicle treated PSD rats. OLP resulted in decreased levels of ChAT and ACH, whereas the degree of histone acetylation and phosphorylation of CREB improved in dose dependent pattern.
Conclusion:
treatment of OLP improved PSCI via increasing the phosphorylation of CREB and histone acetylation, thus attenuating cholinergic activity.
Peutz Jeghers syndrome (PJS) is an autosomal dominant genetic disorder caused by STK11 mutation with a predisposition to gastrointestinal polyposis and cancer. PJS patients suffer poor quality of ...life and are highly concerned about whether deleterious mutations transmit to their offspring. Therefore, this study aimed to propose feasible clinical management and provide effective preimplantation genetic testing for monogenic defect (PGT-M) strategies to protect offspring from inheriting the disease.
A hospital-based clinical retrospective analysis reviewing the clinical characteristics and fertility aspects was first conducted on 51 PJS patients at the First Affiliated Hospital of Zhengzhou University between January 2016 and March 2021. Among the 51 patients, the PGT-M strategy was further carried out in 4 couples, which started with a biopsy of the trophectoderm cells of embryos and whole genome amplification using multiple displacement amplification. Thereafter, single nucleotide polymorphism linkage analyses based on karyomapping were performed with copy number variations of the embryos identified simultaneously. Finally, prenatal diagnosis was used to verify the validity of the PGT-M results.
A comprehensive management flowchart adopted by the multidisciplinary team model was formulated mainly focusing on clinical genetic and gastrointestinal aspects. Under the guidelines of this management, 32 embryos from 4 PJS pedigrees were diagnosed and 2 couples successfully conceived healthy babies free of the STK11 pathogenic mutation.
Our comprehensive management could help affected families avoid having children with PJS through preimplantation genetic testing and provide meaningful guidance for multidisciplinary clinical practice on PJS.
We report the development of a laser gas analyzer that measures gas concentrations at a data rate of 100 Hz. This fast data rate helps eddy covariance calculations for gas fluxes in turbulent high ...wind speed environments. The laser gas analyzer is based on derivative laser absorption spectroscopy and set for measurements of water vapor (H2O, at wavelength ~1392 nm) and carbon dioxide (CO2, at ~2004 nm). This instrument, in combination with an ultrasonic anemometer, has been tested experimentally in both marine and terrestrial environments. First, we compared the accuracy of results between the laser gas analyzer and a high-quality commercial instrument with a max data rate of 20 Hz. We then analyzed and compared the correlation of H2O flux results at data rates of 100 Hz and 20 Hz in both high and low wind speeds to verify the contribution of high frequency components. The measurement results show that the contribution of 100 Hz data rate to flux calculations is about 11% compared to that measured with 20 Hz data rate, in an environment with wind speed of ~10 m/s. Therefore, it shows that the laser gas analyzer with high detection frequency is more suitable for measurements in high wind speed environments.
A series of chiral ligands were synthesized using chloramphenicol base as starting materials. These ligands were applied to the asymmetric catalytic reactions of terminal alkynes with aldehydes to ...obtain a propargyl alcohol product in high yield (80–94%) with excellent enantioselectivities (82–96%).
The (1S, 2S)‐1‐phenyl‐2‐(1‐piperidyl)‐1,3‐propanediol ligand was applied to the asymmetric catalytic reactions of terminal alkynes with aldehydes to obtain a propargyl alcohol product in high yield (80–94%) with excellent enantioselectivities (82–96%).
Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new ...nemati-cidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72h value reached 3.20 mg/L in vitro and the inhibition rate was 100.00％at 40 mg/L in the matrix.The structure-activity relationship of syn-thesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.
Non-wood forest products (NWFPs) derived from understory plants are attracting attention about sustainable forestry development. Geographical distribution and climate correlates of bioactive ...compounds are important to the regional management for the natural reserves of medical plants in forests. In this study, we collected Eleutherococcus senticosus individuals from 27 plots to map the special distribution of concentrations of eleutheroside B, eleutheroside E, and isofraxidin in forests of Northeast China. Compound concentrations in both aerial and underground organs were further detected for relationships with the average of 20-year records of temperature, precipitation, and relative humidity (RH). We found higher shoot eleutheroside B concentration in populations in northern and low-temperature regions (R = −0.4394; P = 0.0218) and in eastern and high-RH montane forests (R = 0.5003; P = 0.0079). The maximum-likelihood regression indicated that both RH (Pr > Chi-square, 0.0201) and longitude (Pr > Chi-square, 0.0026) had positive contributions to eleutheroside B concentration in roots, but precipitation had strongly negative contributions to the concentrations of eleutheroside E (Pr > Chi-square, 0.0309) and isofraxidin (Pr > Chi-square, 0.0014) in roots. Both geography and climate factors had effects on the special distribution of medical compounds in E. senticosus plants in natural populations in Northeast China. The management of NWFP plants at the regional scale should consider effects from climatic geography.
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