Identification of Novel Biomarkers for Abdominal Aortic Aneurysm Promoted by Obstructive Sleep Apnea.

BACKGROUND: We sought to find new biomarkers for abdominal aortic aneurysms (AAA) caused by chronic intermittent hypoxia (CIH). METHODS: The AAA mice model was created using Ang II. The mice were divided into normoxic and CIH groups. The structure of AAA was observed using abdominal ultrasonography, Elastica van Gieson (EVG), and hematoxylin and eosin (HE) staining. The expression of ɑ-SMA was investigated using immunohistochemistry. The novel biomarkers were screened using bioinformatics analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to verify the expression of novel genes in both normal oxygen and CIH. RESULTS: CIH appears to cause greater aortic dilation, higher AAA incidence, lower survival rate, thicker vessel wall, and more brittle elastic lamellae when compared to controls. The immunohistochemistry results showed that the expression of ɑ-SMA in the CIH group was reduced significantly. Four novel genes, including Homer2, Robo2, Ehf, and Asic1, were found to be differentially expressed between normal oxygen and CIH using qRT-PCR, indicating the same trend as bioinformatics analysis. CONCLUSIONS: We discovered that CIH could hasten the occurrence and progression of AAA. Four genes (Homer2, Robo2, Ehf, and Asic1) may be novel biomarkers for AAA, which could aid in the search for new therapies for patients with AAA caused by CIH.

Electronic state evolution of oxygen-doped monolayer WSe2 assisted by femtosecond laser irradiation.

Electronic states are significantly correlated with chemical compositions, and the information related to these factors is especially crucial for the manipulation of the properties of matter. However, this key information is usually verified by after-validation methods, which could not be obtained during material processing, for example, in the field of femtosecond laser direct writing inside materials. Here, critical evolution stages of electronic states for monolayer tungsten diselenide (WSe2) around the modification threshold (at a Mott density of ∼1013 cm-2) are observed by broadband femtosecond transient absorption spectroscopy, which is associated with the intense femtosecond-laser-assisted oxygen-doping mechanism. First-principles calculations and control experiments on graphene-covered monolayer WSe2 further confirm this modification mechanism. Our findings reveal a photochemical reaction for monolayer WSe2 under the Mott density condition and provide an electronic state criterion to in situ monitor the degrees of modification in monolayer transition metal dichalcogenides during the femtosecond laser modification.

Obstructive sleep apnea aggravates neuroinflammation and pyroptosis in early brain injury following subarachnoid hemorrhage via ASC/HIF-1α pathway.

Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage. However, the underlying mechanism remains unclear. In this study, we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea. We found that sleep apnea aggravated brain edema, increased hippocampal neuron apoptosis, and worsened neurological function in this mouse model of subarachnoid hemorrhage. Then, we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died, and lactate dehydrogenase release increased, after 48 hours. We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1ß, interleukin-18, interleukin-6, nuclear factor κB, pyroptosis-related protein caspase-1, pro-caspase-1, and NLRP3, promoted the proliferation of astrocytes, and increased the expression of hypoxia-inducible factor 1α and apoptosis-associated speck-like protein containing a CARD, which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway. We also found that knockdown of hypoxia-inducible factor 1α expression in vitro greatly reduced the damage to HY22 cells. These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis, at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.

Elaborated Reaction Pathway of Photothermal Catalytic CO2 Conversion with H2 O on Gallium Oxide-Decorated and -Defective Surfaces.

Ga2 O3 -decorated and -defective surface models based on anatase TiO2 have been established. The thermodynamic reaction pathways, including protonation, deoxygenation and hydroxylation steps, during CO2 conversion with H2 O to C1 products were calculated. The calculation results demonstrate that a Ga2 O3 cocatalyst enhances the selective adsorption of CO2 and slightly weakens the competitive adsorption of H2 O. The promotion effect of Ga2 O3 on the subsequent reaction depends on the availability of protons and electrons. Free-energy calculations revealed that the basic functional site generated by Ga2 O3 not only suppresses the back reaction of the OH group after H2 O directly provides protons but also maintains the surface defect oxygen vacancy (VO ), which promotes the reaction thermodynamics but tends to be consumed in the process. Additionally, Ga2 O3 decoration promotes VO formation, and the coexistence of Ga2 O3 and VO further decreases the reaction rate-determining step energy barrier, promoting C1 production.

Room-Temperature Synthesis of Air-Stable Near-Infrared Emission in FAPbI3 Nanoparticles Embedded in Silica.

Hybrid organic-inorganic and all-inorganic metal halide perovskite nanoparticles (PNPs) have shown their excellent characteristics for optoelectronic applications. We report an atmospheric process to embed formamidinium CH(NH2)2PbI3 (FAPbI3) PNPs in silica protective layer at room temperature (approximately 26 °C) employing (3-aminopropyl) triethoxysilane (APTES). The resulting perovskite nanocomposite (PNCs) achieved a high photoluminescence (PL) quantum yield of 58.0% and good stability under atmospheric moisture conditions. Moreover, the PNCs showed high PL intensity over 1 month of storage (approximately 26 °C) and more than 380 min of PNCs solutions in DI water. The studied near-infrared (NIR) light-emitting diode (LED) combined a NIR-emitting PNCs coating and a blue InGaN-based chip that exhibited a 788 nm electroluminescence spectrum of NIR-LEDs under 2.6 V. This may be a powerful tool to track of muscle and disabled patients in the detection of a blood vessel.

Observation of quantum-confined exciton states in monolayer WS2 quantum dots by ultrafast spectroscopy.

Monolayer transition metal dichalcogenide quantum dots (TMDC QDs) could exhibit unique photophysical properties, because of both lateral quantum confinement effect and edge effect. However, there is little fundamental study on the quantum-confined exciton dynamics in monolayer TMDC QDs, to date. Here, by selective excitations of monolayer WS2 QDs in broadband transient absorption (TA) spectroscopy experiments, the excitation-wavelength-dependent ground state bleaching signals corresponding to the quantum-confined exciton states are directly observed. Compared to the time-resolved photophysical properties of WS2 nanosheets, the selected monolayer WS2 QDs only show one ground state bleaching peak with larger initial values for the linear polarization anisotropy of band-edge excitons, probably due to the expired spin-orbit coupling. This suggests a complete change of the band structure for monolayer WS2 QDs. In the femtosecond time-resolved circular polarization anisotropy experiments, a valley depolarization time of ∼100 fs is observed for WS2 nanosheets at room temperature, which is not observed for monolayer WS2 QDs. Our findings suggest a strong state-mixing of band-edge valley excitons responsible for the large linear polarization in monolayer WS2 QDs, which could be helpful for understanding the exciton relaxation mechanisms in colloidal monolayer TMDC QDs.

Histomorphological Identification of Nandina domestica / 中国实验方剂学杂志

Objective::Histomorphological study of the Nandinae Radix, Nandinae Caulis, Nandinae Folium, Nandinae Fructus were conducted to provide the basis for the identification of its authenticity and falsehood. Method::The origin and macroscopic identification were used to describe the plant morphology and the appearance characteristics of all medicinal parts. The microscopic characteristics of the medicinal parts, such as roots, stems, leaves, flowers, fruits, were observed and photographed by paraffin section and powder preparation techniques. Result::It was found that the morphological characteristics of the original plant were consistent with the descriptions in herbaceous books. There was no pith on the cross-section of roots. In the transverse section of stems, there were intermittent circular fiber bundles in the cortex and a cap-shaped fibrous bundle in the inner part of the xylem. In the transverse section of the leaves, the palisade tissue was wider and the fiber bundles around the main vascular bundles formed a ring. In the transverse section of petiole, the fiber bundles were arranged intermittently into rings. In the transverse section of fruit, multi-layered sclereids formed a ring in the mesocarp. The powder characteristics of root and stem mainly contained crystalliferous sclereids. There were crystal sheath fibers and stomatal infinitive in the leaf powder, and pollen grains in the flower powder, with 3-hole grooves, obvious reticulate engraving pattern in the outer wall and more reticulate cells. There were a large number of branched sclereids and calcium oxalate square crystals in the fruit powder. Conclusion::The above-mentioned morphological and microscopic features have identification significance, and provide scientific basis for the authenticity identification, the quality standard and the utilization of resources of Nandina domestica.

Quantum Dynamics with Spatiotemporal Control of Interactions in a Stable Bose-Einstein Condensate.

Optical control of atomic interactions in quantum gases is a long-sought goal of cold atom research. Previous experiments have been hindered by rapid decay of the quantum gas and parasitic deformation of the trap potential. We develop and implement a generic scheme for optical control of Feshbach resonances which yields long quantum gas lifetimes and a negligible parasitic dipole force. We show that fast and local control of interactions leads to intriguing quantum dynamics in new regimes, highlighted by the formation of van der Waals molecules and localized collapse of a Bose condensate.

Tetracysteine as a reporter for gene therapy.

OBJECTIVE: To study the feasibility of using tetracysteine (TC) reporter in gene therapy. METHODS: Effects of TC reporter and conventional reporter genes encoding green fluorescence protein (GFP) and luciferase (Luc) on expression and function of the therapeutic gene MGMT(P140K) were compared. Cytotoxicity and drug resistance were studied by Western blot. TC reporter used in therapy was analyzed by flow cytometry (FCM). RESULTS: The TC reporter had no toxicity to cells and neither affected the expression or activity of therapeutic gene as compared to GFP and Luc. TC could be used in blood sample detection. CONCLUSION: TC is a new kind of reporter gene for lentiviral vector in future gene therapy.

[Improving baculovirus transduction of mammalian cells by spinoculation].

Recently many reports have described that recombinant baculovirus could serve as a new gene transfer vehicle for mammalian cells with many unique advantages. In this study, the constructed recombinant baculovirus BacV-CMV-EGFPA containing the enhanced green fluorescent protein (eGFP) gene driven by CMV promoter was used to explore the feasibility of improving the efficiencies of transduction experiment in CV-1 cells by centrifugal method. Refer to the centrifugal transduction protocol of recombinant lentivirus, CV-1 cells were incubated with the culture supematant of Sf-21 cells infected by BacV-CMV-ECFPA (moi = 30) and then centrifuged at 600g for 1 h at RT, reporter gene transfer and expression efficiencies were analyzed by flow cytometry (FCM) 48h post transduction. Results showed that centrifugal method can achieve higher gene delivery and expression efficiencies than transduction by simple virus-cell mixing for 4h at 27 t with least impairment to cell viability. The centrifugal transduction protocol was further optimized by testing different centrifugal times, post-centrifugation incubation times and surrounding solutions. We found that centrifugation at 600g for 1 h at RT is sufficient to achieve the highest transduction efficiencies in target cells and PBS is more suitable than other surrounding solutions. Compared with previous protocol in which tranduction occurs for 4 - 8h at 27 degrees C, centrifugal method developed in this study could achieve more higher transduction efficiencies in more shorter time. Nine different mammalian cell lines (CV-1, 293FT, HepG2, 293T, CHO, C127, MT4, H9, Molt-4) were used to investigate the feasibility of delivering exogenous genes into different mammalian cells with the BacV-CMV-EGFPA supernatant (moi = 30) at 600g for 1h in PBS surrounding solution at RT. Results showed that most mammalian cell lines used in this study could be effectively transduced with recombinant baculoviruses by centrifugal method, and more higher and satisfactory transduction efficiencies could be achieved in primate adherent culture cells than in suspended culture cells. These results show that the baculovirus centrifugal transduction protocol have notable advantages: more rapid, efficient and nontoxic, and could be easily used in daily common experiments.

Hydrophobicity of reactive site loop of SCCA1 affects its binding to hepatitis B virus.

AIM: To investigate the role of SCCA2 and other SCCA1 molecules in the process of hepatitis B virus (HBV) binding to mammalian cells. METHODS: SCCA1 and SCCA2 were isolated from HepG2. Binding protein (BP) genes were obtained through PCR. Recombinant baculoviruses expressing SCCA1, SCCA2, BP, and different mutants were constructed and utilized to infect mammalian cells to investigate the binding ability of infected cells to HBV. RESULTS: A SCCA1 gene (A1) was isolated from HepG2, but it appeared to lack the binding ability of infected cells to HBV. Two mutants, A1-BP and BP-A1, were constructed by interchanging the carboxyl terminal of A1 and BP. Cells expressing A1-BP showed an increased virus binding capacity, but not BP-A1. Comparison of A1 sequence with the sequence of BP indicated the presence of only three amino acid changes in the carboxyl terminal, two of them were found in the reactive site loop (RSL) of SCCA1. Primary structure assay revealed that the hydrophobicity of BP and AJ515706 in this domain was strong, but A1 was relatively weak. Changing the aa349 of A1 from low hydrophobic glutamic acid to high hydrophobic valine enhanced HBV binding. In contrast, HBV binding was reduced by changing the aa349 of BP from valine to glutamic acid. CONCLUSION: The results suggest that the hydrophobicity of RSL of SCCA1 may play an important role in HBV binding to cells.

[Hydrophobicity of reactive site loop of SCCA1 affects its binding to HBV].

Squamous cell carcinoma antigen 1 (SCCA1), a member of the ovalbumin family of serine protease inhibitors, includes several variants. It was reported that expression of two SCCA1 (BP and AJ515706) in cells results in increased binding of HBV to these cells by the interaction of the expressed BP and AJ515706 with HBV pre-S1 domain. In this study, a SCCA1 (A1) was isolated from HepG2, but it appears to lack this ability. A possible role of two mutants, A1-BP and BP-A1, constructed by interchanging the carboxyl terminal of A1 and BP, was investigated. Cells expressing A1-BP rather than BP-A1 showed an increased virus binding capacity. Comparison of A1 sequence with the sequence of BP indicated the presence of only three amino acid changes in the carboxyl terminal, two of them in the reactive site loop (RSL) of SCCA1. Primary structure analysis revealed that the hydrophobicity of BP and AJ515706 in this domain is higher than that of A1. Changing the aa349 of A1 from low hydrophobic glutamic acid to high hydrophobic valine enhanced HBV binding. In contrast, changing the aa349 of BP from valine to glutamic acid reduced HBV binding. Our finding suggests that the hydrophobicity of RSL of SCCA1 may play an important role in HBV binding to cells.

A rapid and efficient method to express target genes in mammalian cells by baculovirus.

AIM: To investigate the modification of baculovirus vector and the feasibility of delivering exogenous genes into mammalian cells with the culture supernatant of Spodoptera frugiperta (Sf9) cells infected by recombinant baculoviruses. METHODS: Two recombinant baculoviruses (BacV-CMV-EGFPA, BacV-CMV-EGFPB) containing CMV-EGFP expression cassette were constructed. HepG2 cells were directly incubated with the culture supernatant of Sf9 cells infected by recombinant baculoviruses, and reporter gene transfer and expression efficiencies were analyzed by flow cytometry (FCM). The optimal transduction conditions were investigated by FCM assay in HepG2 cells. Gene-transfer and expression efficiencies in HepG2 or CV1 cells by baculovirus vectors were compared with lipofectAMINE, recombinant retrovirus and vaccinia virus expression systems. Twenty different mammalian cell lines were used to investigate the feasibility of delivering exogenous genes into different mammalian cells with the culture supernatant of infected Sf9 cells. RESULTS: CMV promoter could directly express reporter genes in Sf9 cells with a relatively low efficiency. Target cells incubated with the 1:1 diluted culture supernatant (moi=50) for 12 h at 37 degrees C could achieve the highest transduction and expression efficiencies with least impairment to cell viability. Under similar conditions the baculovirus vector could achieve the highest gene-transfer and expression efficiency than lipofectAMINE, recombinant retrovirus and vaccinia virus expression systems. Most mammalian cell lines could be transduced with recombinant baculovirus. In primate adherent culture cells the recombinant baculovirus could arrive the highest infection and expression efficiencies, but it was not very satisfactory in the cell lines from mice and suspended culture cells. CONCLUSION: Mammalian cells incubated with the culture supernatant of infected Sf9 cells could serve as a very convenient way for rapid and efficient expression of foreign genes in mammalian cells, but it might be more suitable for primate adherent culture cells.

[Mammalian gene-transfer and expression efficiencies of baculovirus bacV-CMV-EGFPA].

It has been reported that baculoviruses could serve as a new gene-transfer vehicle for mammalian cells. We have previously constructed recombinant baculovirus BacV-CMV-EGFPA and have proven that mammalian cells could be effectively infected by the recombinant baculovirus. In this report, we studied the efficiency of baculovirus to deliver exogenous gene into twenty mammalian cells, including twelve human cell lines (WI-38, Hela, HepG2, 293, PLC/PRF/5, 143B, MCF-7, BGC-223, DMS 114, CNE, Raji, LCL-cm), seven murine cell lines (BNL 1ME A.7R.1, CHO-K1, L-929, JC, PT67, NIH3T3, P815) and one monkey cell line (CV1). Results showed that most mammalian cell lines could be transduced by the recombinant baculovirus, the transduction efficiencies of the human and monkey cell lines were markedly higher than that of murine cell lines, and the transduction efficiencies in adherent culture cell lines higher than that of suspend culture cell lines, implying that the infection efficiency of the baculovirus may be correlative with the organism used and the growth properties of the cell lines. The plasmid pcDNA3. 1-EGFP, which contains the CMV promoter and EGFP reporter gene, was next transfected by LipofectAMINE into a number of mammalian cells, especially those cells that were low in the baculovirus transfection. Results showed that the CMV promoter could effectively direct the expression of the reporter gene in these mammalian cells. Therefore the gene-expression efficiencies in different mammalian cell lines by the recombinant baculovirus which contains the same CMV promoter were dictated by the ability of the baculovirus to enter the cell lines. This study suggested that the recombinant baculovirus vector is more suitable for gene expression in primate adherent culture cells than in murine cells and suspend culture cells.

[Rapid and efficient expression of foreign genes in mammalian cells by baculovirus vectors].

The baculovirus insect cell expression system has been used extensively for the expression of recombinant proteins in insect cells. Recently, reports have described that recombinant baculoviruses can transduce a broad spectrum of primary and established mammalian cells, which shows the baculoviruses could serve as a new gene-transfer vehicle for mammalian cells. In this report, we further research the modification of baculovirus vector and the way to deliver exogenous gene into mammalian cells. On the base of Bac-to-Bac baculovirus insect cell expression system, two recombinant baculoviruses (BacV-CMV-EGFPA, BacV-CMV-EGFPB) were constructed containing different direction of CMV promoters which controll the expression of a reporter gene (EGFP). We found that CMV promoter could direct expression of reporter gene in Sf9 cells with relatively low efficiency. The culture supernatant of Sf9 cells which have been infected by the recombinant baculoviruses for four days were collected and the titers of the viruses in culture supernatant were determined by plaque assay on Sf9 cells. The HepG2 cells, an human hepatocellular carcinoma cell line, were directly incubated with the collected culture supernatant which contains the recombinant baculoviruses for 8 hours in 37 degrees C CO2 incubator (moi = 100). Twenty-four hours post transduction the efficiencies of gene-transfer and expression were analyzed by flow cytometry (FCM) which detect the green fluorescence of individual cells. Results show that these two recombinant baculoviruses have similar gene-transfer and expression efficiency in HepG2 cells, which means the direction of CMV promoters has no effects on reporter gene expression. The optimal transduction conditions of incubating the mammalian cells with the culture supernatant of Sf9 cells infected by recombinant baculoviruses for four days were determined by FCM assay in HepG2 cells. The HepG2 cells inoculated in 24-well plate (5 x 10(4)/well) were incubated with the culture supernatant (BacV-CMV-EGFPA, 1.2 x 10(7) pfu/mL) serially diluted by DMEM culture medium containing 10% FBS and the transduction times ranged from 1 to 24 hours. Twenty-four hours post transduction the efficiencies of gene-transfer and expression were analyzed by FCM. Results show that incubating the target cells with the 1:1 diluted culture supernatant (moi = 50) for 12 hours in 37 degrees C CO2 incubator would achieve the highest infection and expression efficiency with the least impairment on cell viability. We compared the gene-transfer and expression efficiency of recombinant baculovirus in HepG2 and CV1 cells with lipofectAMINE and recombinant retrovirus system, results show that under the similar conditions the recombinant baculovirus could achieve the highest gene-transfer and expression efficiency than the other two systems. So we can draw a conclusion that directly incubating the mammalian cells with the culture supernantant of the infected Sf9 cells could serve as a very convenient way for rapid and efficient expression of foreign gene in mammalian cells.