Rheumatoid arthritis is a chronic inflammatory disorder of polyarticular tissues, characterised by progressive synovitis. Its prolonged treatment imparts a huge burden on the healthcare system and ...results in toxicity, which necessitates the search for safe, efficacious and cost-effective therapies.
Diospyros malabarica
(Desr.) Kostel is traditionally used for anti-inflammatory purposes; however, to the best of our knowledge, there is no detailed study reporting the in vivo anti-inflammatory potential of this plant. Therefore, in the current study, the methanol extract of
D. malabarica
(Desr.) Kostel fruit (mDMF) was evaluated for its antioxidant, anti-inflammatory and anti-arthritic potentials, along with its underlying mechanisms. The antioxidant activity was evaluated by DPPH assay. Total phenolic and flavonoid contents were estimated via colorimetric and high-performance liquid chromatography (HPLC) methods. Different doses (250, 500 and 750 mg/kg) of mDMF were used to evaluate the anti-inflammatory and anti-arthritis actions in acute inflammatory (carrageenan and histamine-induced paw oedema) and Freund’s complete adjuvant (FCA)-induced arthritis rat models. Levels of various pro- and anti-inflammatory biomarkers were estimated using ELISA and RT-PCR techniques. Paw samples were used for different histopathological and radiographic studies. Qualitative phytochemical and HPLC analyses indicated the presence of various polyphenolic compounds in mDMF, which exhibited marked antioxidant activity in the DPPH assay. mDMF showed time-dependent anti-inflammatory and anti-arthritic effects in in vivo models. ELISA assay data showed significant (
p
< 0.05) reduction in the serum levels of C-reactive protein and rheumatoid factor in the mDMF treatment groups. RT-PCR data showed significant (
p
< 0.05) down-regulation of various pro-inflammatory markers (TNF-α, NF-κB, COX-2, IL-1β and IL-6) and up-regulation of anti-inflammatory markers (IκB, IL-4 and IL-10) in serum samples of rats treated with mDMF. The histopathology of the ankle joints showed reduced pannus formation, joint swelling and synovial hyperplasia in mDMF-treated animals when compared with the untreated disease control group. Overall, it may be concluded that the antioxidant, anti-inflammatory and anti-arthritis properties of mDMF are due to its flavonoid and phenolic constituents. Further studies using a stable oral dosage form of
D. malabarica
(Desr.) Kostel fruits extract are warranted to explore its effects in other inflammatory disorders, including irritable bowel syndrome, appendicitis and hepatitis.
Graphical abstract
V diskusi o období raného středověku je z archeologického hlediska nadále třeba se vyrovnat s absencí sídel přiřaditelných ke vznikající šlechtě, z historického hlediska je neméně palčivým problémem ...otázka, co geneze šlechty signalizuje v rámci celospolečenských proměn. Pozorování základního uspořádání vybraných hradních a jiných elitních sídel v západním kulturním prostředí a jejich srovnání s podobou románských kostelů vybavených západní věží z českého území vede k předložení diskusního závěru, že rané české hrady se skrývají v objektech, jež dnes považujeme za výhradně církevní stavby. Výstavba raných hradů (tj. kostelů), jejichž terminologie je odvozena od latinského castellum, doprovázela společenské proměny spočívající v postupném rozpadu archaických příbuzenských společenství – klanů.
A gas geochemical precursor anomaly was identified prior to the October 2008 Nový Kostel (Czech Republic) earthquake swarm with a peak magnitude ML of 3.8. This anomaly was observed as a deviation of ...CO2 concentrations from the long‐term annual CO2 concentration trend in the gas extracted from the scree at the Nový Kostel and Oldřišská gas monitoring stations, which are directly above the Plesná valley‐Počátky and Mariánské Lázně fault systems. Both sites are located within the major focal zone of the NW Bohemian swarm earthquake region at the northern edge of the Cheb Basin. A decrease in CO2 concentration started at Nový Kostel in September 2008, 17 days before the swarm, opposite to the usually increasing annual trend in the autumn period, and ended with a nearly coseismic drop immediately prior to the onset of the first swarm. The CO2 concentrations at Oldřišská, deviating from the annual trend, did not further increase after August 2008. The calculated horizontal strain field, based on the data of two permanent Global Navigation Satellite Systems stations, proved there was horizontal compression in this period. The increasing compression along the Plesná valley‐Počátky and Mariánské Lázně fault systems during the stress build‐up reduced the fault permeability prior to this earthquake swarm as indicated by the decrease in CO2 concentration. The 17‐day duration of the earthquake precursor at Nový Kostel and about 65 days at Oldřišská lie within the range of the precursor times that are hypothesized worldwide for an ML = 3.8 earthquake. The nature of earthquake precursors and their origin are discussed, for example, as an indication of changed fault permeability by stress build‐up in the case of the Nový Kostel swarm earthquake precursor or as fault opening in other cases.
A gas geochemical precursor was identified in the gas directly above the Plesná valley‐Počátky fault systems prior to the October 2008 Nový Kostel, Czech Republic, earthquake swarm (peak magnitude ML = 3.8). It was observed as a deviation of CO2 concentrations from the annual CO2 concentration trend. CO2 concentration started decreasing 17 days before the swarm, matching the hypothesised duration of a precursor for an ML = 3.8 earthquake. The strain field provided evidence of horizontal compression during this period.
The West Bohemia/Vogtland region, characterized by the intersection of the Eger (Ohře) Rift and the Mariánské Lázně fault, is a geodynamically active area exhibiting repeated occurrence of earthquake ...swarms, massive CO2 emanations and mid Pleistocene volcanism. The Eger Rift is the only known intra-continental region in Europe where such deep seated, active lithospheric processes currently take place. We present an image of electrical resistivity obtained from two-dimensional inversion of magnetotelluric (MT) data acquired along a regional profile crossing the Eger Rift. At the near surface, the Cheb basin and the aquifer feeding the mofette fields of Bublák and Hartoušov have been imaged as part of a region of very low resistivity. The most striking resistivity feature, however, is a deep reaching conductive channel which extends from the surface into the lower crust spatially correlated with the hypocentres of the seismic events of the Nový Kostel Focal Zone. This channel has been interpreted as imaging a pathway from a possible mid-crustal fluid reservoir to the surface. The resistivity model reinforces the relation between the fluid circulation along deep-reaching faults and the generation of the earthquakes. Additionally, a further conductive channel has been revealed to the south of the profile. This other feature could be associated to fossil hydrothermal alteration related to Mýtina and/or Neualbenreuth Maar structures or alternatively could be the signature of a structure associated to the suture between the Saxo-Thuringian and Teplá-Barrandian zones, whose surface expression is located only a few kilometres away.
•Regional geoelectric strike direction is compatible with the Eger Rift.•Electrical resistivity model reveals conductor associated with the Cheb Basin.•Deep-reaching conductive channel spatially associated to the earthquake swarms.•Conductive channel interpreted as pathway from a mid-crustal fluid reservoir.•Resistivity model reinforces role of fluids in earthquake swarm triggering.
We present a three-dimensional (3-D) P-wave attenuation (Qp) model for the geodynamically active swarm earthquake area of West Bohemia/Vogtland in the Czech/German border region. Path-averaged ...attenuation t* is calculated from amplitude spectra of time windows around the P-wave arrivals of local earthquakes. Average t/t* value or Qp for stations close to Nový Kostel are very low (<150) compared to that of stations located further away from the focal zone (increases up to 500 within 80km distance). The SIMUL2000 tomography scheme is used to invert the t* for P-wave attenuation perturbation. Analysis of resolution shows that our model is well-resolved in the vicinity of earthquake swarm hypocenters. The prominent features of the model are located around Nový Kostel focal zone and its northern vicinity. Beneath Nový Kostel a vertically stretched (down to depth of 11km) and a highly attenuating body is observed. We believe that this is due to fracturing and high density of cracks inside the weak earthquake swarm zone in conjunction with presence of free gas/fluid. Further north of Nový Kostel two highly attenuating bodies are imaged which could represent fluid channels toward the surface. The eastern anomaly shows a good correlation with the fluid accumulation area which was suggested in 9HR seismic profile.
•The prominent features of the model are located around Novy Kostel focal zone and its northern vicinity.•The highly attenuating anomaly beneath Novy Kostel is due to high density of cracks inside the weak earthquake swarm zone.•The anomaly at the eastern side of Novy Kostel shows a good correlation with the suggested fluid trap in 9HR seismic profile.
The new in situ geodynamic laboratory established in the framework of the ICDP Eger project aims to develop the most modern, comprehensive, multiparameter laboratory at depth for studying earthquake ...swarms, crustal fluid flow, mantle-derived CO.sub.2 and helium degassing, and processes of the deep biosphere. In order to reach a new level of high-frequency, near-source and multiparameter observation of earthquake swarms and related phenomena, such a laboratory comprises a set of shallow boreholes with high-frequency 3-D seismic arrays as well as modern continuous real-time fluid monitoring at depth and the study of the deep biosphere.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
CO2 has long been suspected of driving the Bohemian earthquake swarms because of the migrating nature of the swarms and expressions of CO2 degassing at the surface. Modeling to date primarily ...employed linear diffusion models, but more sophisticated modeling that includes a coupled fluid - and rock mechanical model has been lacking. In this work, we apply a model that couples mechanics to heat and flow of a super-critical CO2 through a fracture network. We present a continuum mechanical approach to derive the seismic moment magnitude using the deviatoric strain as an indicator of rupturing processes during individual events. We use a peak-detection algorithm to identify rapid changes in deviatoric strain, indicative of slip events. This method has been shown to work very well in dry and fluid-induced fracturing experiments at the laboratory scale, and in this work we extend the method to the scale of the West Bohemia/Vogtland earthquake swarms. We show very good agreement between model results and observations of the 2008 swarm, further supporting the hypothesis that the Bohemian earthquake swarms are predominately fluid-driven.
•High pressure fluids are triggering and driving the Bohemian swarms.•Temperature has only a minor influence on the behavior of this system.•We can estimate location and magnitude of numerical analogs for earthquakes.
A singular sequence of three episodes of
M
L
3.5, 4.4 and 3.6 mainshock-aftershock occurred in the West Bohemia/Vogtland earthquake-swarm region during 2014. We analysed this activity using the ...WEBNET data and compared it with the swarms of 1997, 2000, 2008 and 2011 from the perspective of cumulative seismic moment, statistical characteristics, space-time distribution of events, and prevailing focal mechanisms. For this purpose, we improved the scaling relation between seismic moment
M
0
and local magnitude
M
L
by WEBNET. The total seismic moment released during 2014 episodes (
M
0
tot
≈
1.58
×
10
15
Nm) corresponded to a single
M
L
4.6
+
event and was comparable to
M
0
tot
of the swarms of 2000, 2008 and 2011. We inferred that the
M
L
4.8
earthquake is the maximum expected event in Nový Kostel (NK), the main focal zone. Despite the different character of the 2014 sequence and the earthquake swarms, the magnitude-frequency distributions (MFDs) show the
b
-values
≈
1 and probability density functions (PDFs) of the interevent times indicate the similar event rate of the individual swarms and 2014 activity. Only the
a
-value (event-productivity) in the MFD of the 2014 sequence is significantly lower than those of the swarms. A notable finding is a significant acceleration of the seismic moment release in each subsequent activity starting from the 2000 swarm to the 2014 sequence, which may indicate an alteration from the swarm-like to the mainshocks-aftershock character of the seismicity. The three mainshocks are located on a newly activated fault segment/asperity (D in out notation) of the NK zone situated in the transition area among fault segments A, B, C, which hosted the 2000, 2008 and 2011 swarms. The segment D appears to be predisposed to an oblique-thrust faulting while strike-slip faulting is typical of segments A, B and C. In conclusion, we propose a basic segment scheme of the NK zone which should be improved gradually.
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