Search

The high backpressure heating mode of direct air-cooling unit faces limitations due to the return water temperature of heat network and the coordinated heat exchanger unit control of air-cooling island. This limitation complicates the task of achieving a balance between operation economy and power generation output. To solve this inherent contradiction， Ebsilon Professional， a commercial software， is used to calculate and analyze the key parameters of the direct air-cooling exhaust steam extraction heat supply system. These parameters include the backpressure of the air-cooling island， steam turbine output and heat consumption， and suction coefficient of the injector under different loads and variable operating conditions. The calculations reveal that， during low load in winter， the optimal operating backpressure for the heat supply system falls within the range of 13~20 kPa， which allows for the gradient utilization of heating energy， ensures a balance in unit output， and meets the safety requirements for preventing freezing.

Objective To explore the different effects of rapid hypothermia on the electrophysiological characteristics of pyramidal neurons and interneurons in epileptic patients. Methods A total of 13 brain tissue samples were selected from patients with focal drug ⁃ resistant epilepsy who underwent epileptogenic lesion resection in Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University from June to December 2016. Using perfusion method, the brain tissue slice temperature was quickly reduced to 20 ℃ in a step manner, then rewarmed to 30 ℃, and maintained at 30 ℃ for 10 min (the target temperature was changed by 5 ℃ every 10 min). Patch clamping technique was used to record the resting membrane potential, synaptic activity and action potential of pyramidal neurons (n=18) and interneurons (n=6) in epileptic cerebral cortex. Results 1) Resting membrane potential: when the temperature dropped to 20 ℃, the resting membrane potential of the two kinds of neurons showed slight depolarization, but there was no statistical significance in the changes of resting membrane potential at different temperatures and the changes of resting membrane potential of the two kinds of neurons at the same temperature (P＞0.05, for all). 2) Synaptic activity: after cooling, the amplitude of excitatory postsynaptic current (EPSC) of interneuron was smaller (F=5.332, P=0.034). The normalized percentages of EPSC (F=8.811, P=0.000) and inhibitory postsynaptic current (IPSC; F=9.843, P=0.000) amplitude, EPSC event interval (F=7.065, P=0.001), EPSC (F=6.281, P=0.002) and IPSC (F=8.266, P=0.000) peak area were statistically significant. 3) Action potential: there were no significant differences in the effects of temperature change on the normalized percentages of the threshold, frequency, amplitude and half⁃width time of the action potential of the two kinds of neurons (P＞0.05, for all). However, the differences of normalized percentages of action potential frequency (F=4.801, P=0.008), amplitude (F=3.680, P=0.015) and half⁃width time (F=28.951, P=0.000) of neuronal action potentials at different temperatures were statistically significant. Conclusions When the temperature was reduced to 20 ℃, the electrophysiological activities of the two kinds of neurons were significantly inhibited. The inhibition of EPSC amplitude of synaptic activity in interneurons was stronger than that in pyramidal neurons. Inhibition of interneuron activity may be one of the reasons for hypothermia prevention and termination of epilepsy.

Summary: Actively controlled nanoliter fluid circuits are an urgently needed technology in electronics, biomedicine, chemical synthesis, and biosensing. The difficulty lies in how to drive the microfluid in an isolated and airtight manner in glass wafer. We used a magnetic oscillator pump to realize the switching of the circulation direction and controlling the flow rate of the 10nL fluid. Results of two-dimensional numerical simulations shows that the flow field can reach a steady state and a stable flow can be obtained. The contribution of each vibration cycle to the flow rate is proportional to the frequency, decays exponentially with the viscosity, is proportional to the 4.2 power of the amplitude, and is proportional to the radius. Compared with the existing fluid technology, this technology realizes the steering and flow control of a fully enclosed magnetic control fluid circuit as small as 10nL in hard materials for the first time.

Cell-to-cell communication must occur through molecular transport in the intercellular fluid space. Nanoparticles, such as exosomes, diffuse or move more slowly in fluids than small molecules. To find a microfluidic technology for real-time exosome experiments on intercellular communication between living cells, we use the microfluidic culture dish’s quaternary ultra-slow microcirculation flow field to accumulate nanoparticles in a specific area. Taking stem cell–tumor cell interaction as an example, the ultra-slow microcirculatory flow field controls stem cell exosomes to interfere with tumor cells remotely. Under static coculture conditions (without microfluidics), the tumor cells near stem cells (

Background: Main bioactive constituents and pharmacological functions of ripened red ginseng berry (Panax ginseng Meyer) have been frequently reported. Yet, the research gap targeting the beneficial activities of transformed green ginseng berries has not reported elsewhere. Methods: Ginsenosides of new green berry cultivar K-1 (GK-1) were identified by HPLC-QTOF/MS. Ginsenosides bioconversion in GK-1 by bgp1 enzyme was confirmed with HPLC and TLC. Then, mechanisms of GK-1 and β-glucosidase (bgp1) biotransformed GK-1 (BGK-1) were determined by Quantitative Reverse Transcription-Polymerase Chain Reaction and Western blot. Results: GK-1 possesses highest ginsenosides especially ginsenoside-Re amongst seven ginseng cultivars including (Chunpoong, Huangsuk, Kumpoong, K-1, Honkaejong, Gopoong, and Yunpoong). Ginseng root’s biomass is not affected with the harvest of GK-1 at 3 weeks after flowering period. Then, Re is bio-converted into a promising pharmaceutical effect of Rg2 via bgp1. According to the results of cell assays, BGK-1 shows decrease of tyrosinase and melanin content in α-melanocyte-stimulating hormone challenged-murine melanoma B16 cells. BGK-1 which is comparatively more effective than GK-1 extract shows significant suppression of the nuclear factor (NF)-κB activation and inflammatory target genes, in LPS-stimulated RAW 264.7 cells. Conclusion: These results reported effective whitening and anti-inflammatory of BGK-1 as compared to GK-1.

Recently, green synthesis-based nanoformulations using plants or microorganisms have attracted great interest because of their several advantages. Nanotechnology-based biological macromolecules are emerging materials with potential applications in cosmetics and medications for ameliorating and treating inflammatory skin diseases (ISDs). Eupatorium japonicum (EJ), a native Korean medicinal plant belonging to the family Asteraceae, has been traditionally used to prepare prescriptions for the treatment of various inflammatory diseases. EJ-based gold nanoparticles (EJ-AuNPs) were biosynthesized under optimal conditions and characterized their physicochemical properties using various microscopic and spectrometric techniques. Additionally, the effects of EJ-AuNPs on ISDs as well as their underlying mechanisms were investigated in the tumor necrosis factor-α/interferon-γ (T+I)-induced skin HaCaT keratinocytes. The MTT and live/dead cell staining assays showed that EJ-AuNP treatment was considerably safer than EJ treatment alone in HaCaT cells. Moreover, EJ-AuNP treatment effectively suppressed the production of T+I-stimulated inflammatory cytokines (RANTES, TARC, CTACK, IL-6, and IL-8) and intracellular reactive oxygen species, and such EJ-driven anti-inflammatory effects were shown to be associated with the downregulation of intracellular mitogen-activated protein kinase and nuclear factor-κB signaling pathways. The present study provides preliminary results and a valuable strategy for developing novel anti-skin dermatitis drug candidates using plant extract-based gold nanoparticles.

In this study, the effects of Curtobacterium proimmune K3 lysates, isolated from Panax ginseng beverages, on splenocytes and cyclophosphamide (CTX)-induced immunosuppressed mice were investigated. Treatment with C. proimmune K3 lysates stimulated splenocyte proliferation and increased cytokine secretion in vitro and splenocytes ex vivo. Treatment with C. proimmune K3 lysates alleviated CTX-induced immunosuppression by modulating innate immunity in vivo, by recovering immune organ index and natural killer cell cytotoxicity, as well as by stimulating the adaptive immune system, via restoration of splenic lymphocyte proliferation, delayed-type hypersensitivity response, and IgG and IgA content. Moreover, C. proimmune K3 lysates treatment remarkably enhanced cytokine production in the spleen and thymus, compared with CTX-immunosuppressed mice. Our results suggest C. proimmune K3 lysates hold potential as a novel immunomodulatory agent for use in therapeutic purposes or as an ingredient in functional foods.

Abstract In crystalline materials, grain boundary and anisotropy of crystal structure affect their mechanical properties. The effects of interfacial structure on the mechanical properties may be diverse when the multilayer film is loaded along different directions. In this work, we performed a series of molecular dynamics simulations of the tension of in-plane single and polycrystalline Cu/Pd multilayered films with cube-on-cube (COC) and twinned interfaces to explore the effects of the interfacial structure, loading direction and in-plane grain boundaries on their mechanical properties. The interfacial misfit dislocation lines become bent after relaxation, and the high temperature of 300 K was found as a necessary condition. When stretched along 〈110〉 direction, the strengthening effect of the COC interface is more noticeable; however, when stretched along 〈112〉 direction, the twin interface's strengthening effect is more visible, showing the anisotropic effect of interfacial structure on mechanical properties. However, in the in-plane honeycomb polycrystalline sample, the twin interface showed a pronounced strengthening effect, and no jogged dislocations were observed.

Background: Ginsenoside Rh2 is well known for many pharmacological activities, such as anticancer, antidiabetes, antiinflammatory, and antiobesity properties. Glycosyltransferases (GTs) are ubiquitous enzymes present in nature and are widely used for the synthesis of oligosaccharides, polysaccharides, glycoconjugates, and novel derivatives. We aimed to synthesize new ginsenosides from Rh2 using the recombinant GT enzyme and investigate its cytotoxicity with diverse cell lines. Methods: We have used a GT gene with 1,224-bp gene sequence cloned from Lactobacillus rhamnosus (LRGT) and then expressed in Escherichia coli BL21 (DE3). The recombinant GT protein was purified and demonstrated to transform Rh2 into two novel ginsenosides, and they were characterized by nuclear magnetic resonance (NMR) techniques and evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay. Results: Two novel ginsenosides with an additional glucopyranosyl (6→1) and two additional glucopyranosyl (6→1) linked with the C-3 position of the substrate Rh2 were synthesized, respectively. Cell viability assay in the lung cancer (A549) cell line showed that glucosyl ginsenoside Rh2 inhibited cell viability more potently than ginsenoside Rg3 and Rh2 at a concentration of 10 μM. Furthermore, glucosyl ginsenoside Rh2 did not exhibit any cytotoxic effect in murine macrophage cells (RAW264.7), mouse embryo fibroblasts cells (3T3-L1), and skin cells (B16BL6) at a concentration of 10 μM compared with ginsenoside Rh2 and Rg3. Conclusion: This is the first report on the synthesis of two novel ginsenosides, namely, glucosyl ginsenoside Rh2 and diglucosyl ginsenoside Rh2 from Rh2 by using recombinant GT isolated from L. rhamnosus. Moreover, diglucosyl ginsenoside Rh2 might be a new candidate for treatment of inflammation, obesity, and skin whiting, and especially for anticancer.

Raman spectroscopy is well-known for its capability of detecting the physical properties, level of defects and number of layers for graphene-based materials, but far more than that, it's proven to be a versatile and promising tool for characterizing graphene-based polymer composites. This work focuses on the applications of Raman spectroscopy in the field of graphene-based polymer composites. The feature bands in Raman spectroscopy enable direct 2D and 3D imaging of graphene-based nanofillers in the polymer matrix, and even out of other carbonaceous materials. In addition, shifts in the vibrational frequencies of the characteristic bands induced by the strain of graphene could be utilized for analyzing the interactions between graphene-based nanofillers and polymer molecules, for calculating the effective moduli as well as for determining the spatial orientation of graphene-based nanofillers in the matrix. In the meantime, the recent progress of applications of Raman spectroscopy in the field of graphene-based polymer composites is introduced, such as the analysis of micromechanics of graphene-based nanocomposites, the investigation of stress transfer efficiency between the nanofillers and the matrix, and the reveal of key factors affecting material behavior. The Raman spectroscopy researches of graphene-based polymer composites currently are mainly focused on model composites, and the fluorescent effect of the matrix polymer as well limits the further applications of Raman spectroscopy. In order to address such problem, the amplified razor power are often adopted, and the resulted nonlinear effects are capable of increasing the intensity of the Raman signal, thus the Raman spectroscopy will be more widely applied in the field of graphene-based polymer composites.

The occurrence of cancer metastasis may be related to stem cells in normal tissues. We searched for patient IDs with both normal tissue stem cell values and TCGA (The Cancer Genome Atlas) clinical data for pairing and obtained 639 sets of data (stemness index of normal tissue, stemness index of tumor tissue, cancer stage, distant metastasis, tumor size) and invasion, and lymph node involvement). However, clinical data on cancer metastasis are of only four stages (e.g., Stage I, II, III, and IV), which cannot show subtle changes continuously. We need to find an effective data mining method to transform this four-valued clinical description into a numerical curve. We data-mine this data through numericalization, sorting, and noise reduction filtering. The results showed that: as the normal tissue stemness value (NS) increased, the tumor tissue stemness value (TS) increased proportionally (1.26 times NS). When NS >0.5, the rate of change in TS decelerated (0.43 times NS), and tumor metastasis began to occur. Clinical indicators, such as cancer stage, distant metastasis, tumor size and invasion, and lymph node involvement, showed that tumor metastasis became more and more severe with the increase of NS. This study suggests that tumor metastasis is triggered when the NS in the patient's body is more significant than 0.5.

Graphene oxide (GO) modified epoxy resin (GH81) was prepared by mechanical grinding, and the dispersion of GO in the epoxy resin (H81) was analyzed by optical microscope, while the melting performances and curing behaviors of H81 and GH81 were researched through rheometer and differential scanning calorimeter respectively. The results show that GO is uniformly dispersed into the matrix resin，and the addition of GO hardly affects the melt viscosity and curing condition of the matrix resin at all. In addition, the 0° tensile strength, bending strength and compression strength of GH81 based carbon fiber reinforced composite (GH81-300) are 2270 MPa, 2239 MPa and 1529 MPa respectively, which is increased by 6.4%, 7.2% and 7.1% respectively, as compared with that of composite without GO.

Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, β-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. The microbial defluorination products were structurally confirmed and showed regiospecificity and stereospecificity, consistent with their formation by enzymatic reactions. A comparison of defluorination activities among several Acetobacterium species indicated that a functional fluoride exporter was required for the detoxification of the released fluoride. Results from both in vivo inhibition tests and in silico enzyme modeling suggested the involvement of enzymes of the flavin-based electron-bifurcating caffeate reduction pathway [caffeoyl-CoA reductase (CarABCDE)] in the reductive defluorination. This is a report on specific microorganisms carrying out enzymatic reductive defluorination of PFAS, which could be linked to electron-bifurcating reductases that are environmentally widespread.

Effect of low-melting-point curing agent (MOEA) on property of epoxy resin was studied. The properties of epoxy resin (MOEA40) with MOEA as the curing agent were characterized and compared with the epoxy resin (DDM30) with 4, 4'-diaminodiphenyl methane (DDM) as the curing agent. The viscosity-temperature property, curing behavior, mechanical properties and thermal properties were characterized by rotational rheometer, differential scanning calorimetry (DSC), universal material testing machine, dynamic thermomechanical analyzer (DMA) and thermal gravimetric analyzer (TGA), respectively. The results show that MOEA40 has better viscosity-temperature property than that of DDM30. MOEA shows low viscosity (0.2-3.5Pa·s) in the temperature range of 60-140℃. MOEA40 and DDM30 are cured with the same curing progressing. Cured MOEA40 shows outstanding mechanical properties with bending strength about 147MPa and tensile strength about 89 MPa, which are 9.7% and 11.2% higher than that of cured DDM30 (bending strength 134MPa, tensile strength 80MPa). In addition, cured MOEA40 shows higher glass transition temperature (168℃) and higher thermal stability with 5% mass loss temperature about 367℃ in nitrogen atmosphere.

Graphene is widely used in the preparation of polymer matrix composites because of its excellent properties. 3D printing, as an emerging technology, is increasingly applied to the shaping and processing of graphene/polymer composites. In this paper, three kinds of main preparation methods of graphene/polymer composites which are solution mixing, melt blending, and in-situ polymerization were introduced. 3D printing methods and the advantages and disadvantages of inkjet printing, fused deposition modeling (FDM), stereolithography (SLA) and selective laser sintering (SLS) as well as their characteristics were summarized. Besides, the applications of 3D-printed graphene/polymer composites in electronics, energy, biomedical and aerospace were reviewed. Finally, it was pointed out that the further research in this area would be focused on the fabrication of graphene/polymer composites which have good printability, homogeneous dispersed graphene, and excellent functional characteristics.

Abstract Though RNAi and RNA-splicing machineries are involved in regulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication, their precise roles in coronavirus disease 2019 (COVID-19) pathogenesis remain unclear. Herein, we show that decreased RNAi component (Dicer and XPO5) and splicing factor (SRSF3 and hnRNPA3) expression correlate with increased COVID-19 severity. SARS-CoV-2 N protein induces the autophagic degradation of Dicer, XPO5, SRSF3, and hnRNPA3, inhibiting miRNA biogenesis and RNA splicing and triggering DNA damage, proteotoxic stress, and pneumonia. Dicer, XPO5, SRSF3, and hnRNPA3 knockdown increases, while their overexpression decreases, N protein-induced pneumonia’s severity. Older mice show lower expression of Dicer, XPO5, SRSF3, and hnRNPA3 in their lung tissues and exhibit more severe N protein-induced pneumonia than younger mice. PJ34, a poly(ADP-ribose) polymerase inhibitor, or anastrozole, an aromatase inhibitor, ameliorates N protein- or SARS-CoV-2-induced pneumonia by restoring Dicer, XPO5, SRSF3, and hnRNPA3 expression. These findings will aid in developing improved treatments for SARS-CoV-2-associated pneumonia.

Abstract Background LARC patients commonly receive adjuvant therapy, however, hidden micrometastases still limit the improvement of OS. This study aims to investigate the impact of VASN in rectal cancer with pulmonary metastasis and understand the underlying molecular mechanisms to guide adjuvant chemotherapy selection. Methods Sequencing data from rectal cancer patients with pulmonary metastasis from Sun Yat-sen University Cancer Center (SYSUCC) and publicly available data were meticulously analyzed. The functional role of VASN in pulmonary metastasis was validated in vivo and in vitro. Coimmunoprecipitation (co-IP), immunofluorescence, and rescue experiments were conducted to unravel potential molecular mechanisms of VASN. Moreover, VASN expression levels in tumor samples were examined and analyzed for their correlations with pulmonary metastasis status, tumor stage, adjuvant chemotherapy benefit, and survival outcome. Results Our study revealed a significant association between high VASN expression and pulmonary metastasis in LARC patients. Experiments in vitro and in vivo demonstrated that VASN could promote the cell proliferation, metastasis, and drug resistance of colorectal cancer. Mechanistically, VASN interacts with the NOTCH1 protein, leading to concurrent activation of the NOTCH and MAPK pathways. Clinically, pulmonary metastasis and advanced tumor stage were observed in 90% of VASN-positive patients and 53.5% of VASN-high patients, respectively, and VASN-high patients had a lower five-year survival rate than VASN-low patients (26.7% vs. 83.7%). Moreover, the Cox analysis and OS analysis indicated that VASN was an independent prognostic factor for OS (HR = 7.4, P value

The thermo−chemo−mechanical coupling on the thermal shock resistance of 20 vol%-ZrB2−15 vol%-SiC−graphite composite is investigated with the use of a self-developed material testing system. In each test, a specimen under prescribed constant tensile pre-stress (σ0 = 0, 10, 20 and 30 MPa) was subjected to 60 cycles of thermal shock. In each cycle, the specimen was heated from room temperature to 2000 °C within 5 s in an air atmosphere or an Ar atmosphere. The residual flexural strength of each specimen was tested, and the fracture morphology was characterized by using scanning electron microscopy (SEM). There were three different regions in the fracture surface of a specimen tested in the air, while no such difference could be observed in the fracture surfaces of the specimens that were tested in Ar. The residual flexural strength of the composite that was tested in Ar generally decreases with the increase of σ0. However, in the range of 0 ≤ σ0 ≤ 10 MPa, the residual flexural strength of the composite that was tested in the air ascended with the increase of σ0 due to the healing effect of oxidation, but it descended thereafter with a further increase of σ0, as the effect pre-stress that became prominent.

We performed molecular dynamics simulations for uniaxial tension of Cu/Fe nano-multilayered films with different modulation periods (λ) using Kurdjumov-Sachs (K-S) relationship to investigate their interfacial morphologies and the effects of λ on their mechanical properties. It shows that the mismatch dislocation lines at the interfaces are periodic. At the Cu side of the interface, triangles distribute with the smallest period; while at the Fe side, parallelograms distribute with the smallest period. There are two yield points, except the case of λ=2.10 nm where there is only one yield point, in the stress-strain curve of Cu/Fe multilayer film under tension, corresponding to the sequential nucleation of dislocations in the Cu and Fe layers from interface, respectively. We further found that there is a critical modulation period, λc, and the flow stress decreases with the increases of λ if λ > λc while increases with the increases of λ if λ < λc. The possible mechanisms are discussed.