Raziskovanje udorov na kraških območjih z uporabo integriranih geofizikalnih metod: primer iz okrožja Conghua, mesta Guangzhou, Kitajska

Integrated geophysical methods were used to investigate the geological conditions of karst collapses in Aotou, Conghua District, Guangzhou City. Based on audio frequency magnetotelluric (AMT) soundings, high-density electric signals and microtremors, a series of features, including the soil structure and thickness, faults, and hidden karst, were detected from shallow to deep subsurface regions in three-dimensional (3-D) space. These were then compared with geologic and drilling data. The measurements of micro-vibrations and high-density electric signals revealed that the strata in the collapsed area consists of clay and medium-grain sand, which is approximately 8–15 m thick and arranged as a multiple-element structure. The AMT soundings uncovered a hidden structure in the subsurface, which lies at the core of a syncline and adjacent to a contact zone between soluble limestone and non-soluble granite. Combined with the geologic data, the survey using the high-density electric method also showed that the study area hosts the Shidengzi Formation from the Datang Stage of the lower Carboniferous, which contain carbonaceous micrite and dolomitic limestone, locally intercalated with thin quartz siltstone, with well-developed karst. Collectively, the soil structure, hidden structure in the subsurface, and karst development provide the primary conditions for collapses. The main triggering factors for the karst collapses are seasonal variations in groundwater levels and excessive groundwater withdrawals. These results can provide guidance for the selection and application of geophysical methods for the examination of this issue in other areas with similar geology.Pri raziskovanju geoloških razmer za pojav udorov na območju krasa v Aotouju, okrožju Conghua, mesta Guangzhou so bile uporabljene integrirane geofizikalne metode. Z uporabo avdiofrekvenčnih magnetno teluričnih (AMT) sondiranj, visokofrekvenčnih električnih signalov in mikrotremorjev smo zaznali razne elemente v podzemlju, kot so debelina in struktura prsti, prelomi in nepoznani podzemni prostori. Izsledki so bili primerjani s podatki geoloških kartiranj in napravljenih vrtin. Meritve mikrovibracij in električnih signalov so razkrile, da so formacije na območju udorov sestavljene iz gline in srednje zrnatega peska, v skupni debelini približno 8‒15 m. Magnetno telurično sondiranje je pod površjem razkrilo neznano strukturo, ki leži na jedru sinklinale ob stiku med topnim apnencem in netopnim granitom. Skupaj z geološkimi podatki je metoda z električnimi signali pokazala, da področje študije zajema formacijo Shidengzi, stopnje Datang iz spodnjega Karbona, ki vsebuje mikritni in dolomitni apnenec, ki se lokalno izmenjuje s tankimi plastmi kremenovega meljevca. Na tem območju je nastal dobro razviti kras. Ugodna sestava prsti, neznane strukture pod površjem in zakrasevanje zagotavljajo dobre razmere za nastanek udorov. Glavni dejavniki udora kraških območij so sezonska nihanja nivojev podzemne vode in čezmerna črpanja podtalnice. Pridobljeni izsledki zagotavljajo smernice za izbor in uporabo ustreznih geofizikalnih metod za raziskovanje teh težav v drugih regijah s podobno geologijo

An analytical model for flutter behavior of composite panels with shape memory alloy fibers

An analytical model for predicting the effect of shape memory alloys (SMA) on the flutter behavior of composite panels is developed in the frequency and time domains. The laminated plate theory and piston theory are employed to model the aeroelastic response of the composite panels to aerodynamic loads. A thermo-mechanical constitutive equation of SMA proposed by Brinson et al. is used to calculate the recovery stress of the constrained SMA fibers. The approximate solution is obtained for supersonic flutter analysis of the composite panels based on the Galerkin approach. The parametric study is carried out to display the effect of the actuation temperature, volume fraction, the initial strain of SMA fibers and the length to width ratio of the panels on flutter boundaries

Protective effect of paeoniflorin against oxidative stress in human retinal pigment epithelium in vitro

Purpose: This study was conducted to determine whether paeoniflorin (PF) could prevent H(2)O(2)-induced oxidative stress in ARPE-19 cells and to elucidate the molecular pathways involved in this protection. Methods: Cultured ARPE-19 cells were subjected to oxidative stress with H(2)O(2) in the presence and absence of PF. The preventive effective of PF on reactive oxygen species (ROS) production and retinal pigment epithelium (RPE) cell death induced by H(2)O(2) was determined by 2', 7'-dichlorodihydrofluorescein diacetate (H(2)DCFDA) fluorescence and 3-(4, 5dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium bromide (MTT) assay. The ability of PF to protect RPE cells against ROS-mediated apoptosis was assessed by caspase-3 activity and 4', 6-diamidino-2-phenylindole (DAPI) staining. Furthermore, the protective effect of PF via the mitogen-activated protein kinase (MAPK) pathway was determined by western blot analysis. Results: PF protected ARPE-19 cells from H(2)O(2)-induced cell death with low toxicity. H(2)O(2)-induced oxidative stress increased ROS production and caspase-3 activity, which was significantly inhibited by PF in a dose-dependent manner. Pretreatment with PF attenuated H(2)O(2)-induced p38MAPK and extracellular signal regulated kinase (ERK) phosphorylation in human RPE cells, which contributed to cell viability in ARPE-19 cells. Conclusions: This is the first report to show that PF can protect ARPE-19 cells from the cellular apoptosis induced by oxidative stress. The results of this study open new avenues for the use of PF in treatment of ocular diseases, such as age-related macular degeneration (AMD), where oxidative stress plays a major role in disease pathogenesis.Biochemistry & Molecular BiologyOphthalmologySCI(E)PubMed1ARTICLE373-783512-35221

Metabolic Disturbance and Th17/Treg Imbalance Are Associated With Progression of Gingivitis

ObjectiveThis study sought to explore the role of metabolic disturbance in immunoregulation of gingivitis targeting T helper 17 cells (Th17)/regulatory T cell (Treg).Materials and MethodsA total of 20 gingivitis patients and 19 healthy volunteers were recruited. Quantitative real time polymerase chain reaction (qRT-PCR) was used to evaluate expression patterns of Forkhead box protein P3 (Foxp3), transforming growth factor-β (TGF-β), retinoid-related orphan receptor-gammat (RORγt) and interleukin 17A (IL-17A) in the peripheral blood lymphocytes of subjects across the two groups. Moreover, the enzyme-linked immunosorbent assay (ELISA) technique was used to detect levels of TGF-β, IL-4, IL-6,TL-10 and L-17A secreted in the plasma as well as the SIgA secreted in saliva. Flow cytometry was used to detect the percentage of CD4+CD25+ Foxp3+Treg cells and the percentage of CD4+IL-17A+ Th17 cells in whole blood of subjects in both groups. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the plasma metabolites in the gingivitis patient group. Statistical analysis was applied to determine whether the plasma metabolites and related metabolic pathways significantly differed between gingivitis patients and healthy controls. Ingenuity pathway analysis (IPA) was employed to identify the potential relation between the metabolites and the Th17 and Treg related pathway.ResultsThe percentages of CD4+IL17A+Th17 cells and IL-17 significantly increased in the peripheral blood in the gingivitis group. Moreover, the upregulation of IL-17A mRNA and RORγt mRNA were also found in the gingivitis group. However, the percentage of CD4+CD25+ Foxp3+Treg cells and Foxp3 mRNA in the whole blood did not significantly change. However, TGF-β mRNA as well as TGF-β, IL-4, IL-6, IL-10 in the periperial blood and SIgA in the saliva were higher in the gingivitis group. Notably, that the ratio of Th17/Treg cells was significantly increased during peripheral circulation. Furthermore, we identified 18 different metabolites which were differentially expressed in plasma between the gingivitis and healthy control groups. Notably, the levels of cholesterol, glycerol 1-octadecanoate, d-glucose, uric acid, cyclohexaneacetic acid, 3-pyridine, tryptophan, and undecane 2,4-dimethyl were significantly up-regulated. whereas the levels of lactic acid, glycine, linoleic acid, monopalmitic acid, glycerol, palmitic acid, pyruvate, 1-(3-methylbutyl)-2,3,4,6-tetramethylbenzene, 1 5-anhydro d-altrol, and boric acid were down-regulated in the gingivitis group, relative to healthy controls. IPA showed that these metabolites are connected to IL17 signaling, TGF-B signaling, and IL10 signaling, which are related closely to Th17 and Treg pathway.ConclusionOverall, these results showed that disturbance to glycolysis as well as amino and fatty acid metabolism are associated with Th17/Treg balance in gingivitis. Impaired immunometabolism may influence some periodontally involved systemic diseases, hence it is a promising strategy in targeted development of treatment therapies

Performance of a deep learning-based lung nodule detection system as an alternative reader in a Chinese lung cancer screening program

Objective: To evaluate the performance of a deep learning-based computer-aided detection (DL-CAD) system in a Chinese low-dose CT (LDCT) lung cancer screening program. Materials and methods: One-hundred-and-eighty individuals with a lung nodule on their baseline LDCT lung cancer screening scan were randomly mixed with screenees without nodules in a 1:1 ratio (total: 360 individuals). All scans were assessed by double reading and subsequently processed by an academic DL-CAD system. The findings of double reading and the DL-CAD system were then evaluated by two senior radiologists to derive the reference standard. The detection performance was evaluated by the Free Response Operating Characteristic curve, sensitivity and false-positive (FP) rate. The senior radiologists categorized nodules according to nodule diameter, type (solid, part-solid, non-solid) and Lung-RADS. Results: The reference standard consisted of 262 nodules ≥ 4 mm in 196 individuals; 359 findings were considered false positives. The DL-CAD system achieved a sensitivity of 90.1% with 1.0 FP/scan for detection of lung nodules regardless of size or type, whereas double reading had a sensitivity of 76.0% with 0.04 FP/scan (P = 0.001). The sensitivity for detection of nodules ≥ 4 - ≤ 6 mm was significantly higher with DL-CAD than with double reading (86.3% vs. 58.9% respectively; P = 0.001). Sixty-three nodules were only identified by the DL-CAD system, and 27 nodules only found by double reading. The DL-CAD system reached similar performance compared to double reading in Lung-RADS 3 (94.3% vs. 90.0%, P = 0.549) and Lung-RADS 4 nodules (100.0% vs. 97.0%, P = 1.000), but showed a higher sensitivity in Lung-RADS 2 (86.2% vs. 65.4%, P < 0.001). Conclusions: The DL-CAD system can accurately detect pulmonary nodules on LDCT, with an acceptable false-positive rate of 1 nodule per scan and has higher detection performance than double reading. This DL-CAD system may assist radiologists in nodule detection in LDCT lung cancer screening

Phosphomolybdic acid-responsive Pickering emulsions stabilized by ionic liquid functionalized Janus nanosheets

<p><b>A</b> Representative photomicrographs of Caspase-3 immunofluorescence staining (400×). <b>B</b> Quantification of Caspase-3 fluorescence intensity in different groups. <b>C</b> Representative Western blot band of Caspase-3 activation in the ischemic cortex at 24 h after reperfusion. <b>D</b> Effect of LBP (40 mg/kg) on the Caspase-3 activation in MCAO mice cortex at 24 h after reperfusion. Data are expressed as mean±SEM (n = 6). ^##P<0.01 vs. sham-operated group; **P<0.01 vs. vehicle group.</p