The terms mélange and broken formation have been used in different ways in the literature. The lack of agreement on their definition often leads to confusion and misinterpretations. An evaluation of ...the various uses of these terms allows us to consider several types of chaotic rock bodies originated by tectonic, sedimentary and diapiric processes in different tectonic settings. Our review of stratal disruption and mixing processes shows that there exists a continuum of deformation structures and processes in the generation of mélanges and broken formations. This continuum is directly controlled by the increase of the degree of consolidation with burial. In tectonically active environments, at the shallow structural levels, the occurrence of poorly consolidated sediments favors gravitational deformation. At deeper structural levels, the deformation related to tectonic forces becomes gradually more significant with depth. Sedimentary (and diapiric) mélanges and broken formations represent the products of punctuated stratal disruption mechanisms recording the instantaneous physical conditions in the geological environment at the time of their formation. The different kinematics, the composition and lithification degree of sediments, the geometry and morphology of the basins, and the mode of failure propagation control the transition between different types of mass-transported chaotic bodies, the style of stratal disruption, and the amount of rock mixing. Tectonically broken formations and mélanges record a continuum of deformation that occurs through time and different degrees of lithification during a progressive increase of the degree of consolidation and of the diagenetic and metamorphic mineral transformation. Systematic documentation of the mechanisms and processes of the formation of different broken formations and mélanges and their interplay in time and space are highly important to increase the understanding of the evolutionary history of accretionary wedges and orogenic belts.
►Re-evaluation of the definitions of the terms mélange and broken formation. ►Tectonic, sedimentary and diapiric mélanges in different tectonic settings. ►Mechanisms and processes of stratal disruption and mixing.
We identified Dobrava-Belgrade virus infection in Turkey (from a strain related to hantavirus strains from nearby countries) in a patient who had severe symptoms leading to panhypopituitarism, but no ...known risk for hantavirus. Our findings emphasize the need for increased awareness of hantaviruses in the region and assessment of symptomatic persons without known risk factors for infection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVESThe liver biopsy is the gold standard for determining the level of fibrosis in chronic hepatitis B infection (CHBI). Nonetheless, it is possible to predict liver fibrosis through some ...noninvasive methods such as noninvasive scoring (NIS) of some serum biomarkers obtained from routine blood tests. We aimed to evaluate the diagnostic accuracy of nine NIS for detecting advanced fibrosis in CHBI.
PATIENTS AND METHODSWe reviewed the hospital records of CHBI cases with liver biopsy between January 2011 and December 2016 retrospectively. Using Ishak scoring method, we classified fibrosis stage 1–2 as mild and 3–6 as advanced fibrosis. We calculated the NIS by considering the age, platelet count, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, platelet, and international normalized ratio values at the time of the biopsy.
RESULTSThe mean age of 202 patients was 37.69± 11.33 years. In cases with advanced fibrosis, the age, gammaglutamyltransferase, and international normalized ratio values were higher and platelet count was lower (P < 0.05). Mean platelet volume was not different between the two groups (P = 0.499). The median values of γ-glutamyl peptidase-platelet ratio (GPR), FibroQ, Goteborg University Cirrhosis Index, fibrosis-4 (FIB-4), aspartate aminotransferase-platelet ratio index, age-platelet index, and King scoring were significantly higher in the advanced fibrosis group. The highest area under the curve value was in GPR AUC = 0.731 (0.639–0.788); P = 0.000 in the receiver operating characteristic curve analysis. Cirrhosis Discriminant Score and Aspartate aminotransferase-to-alanine aminotransferase ratio tests were not valuable in detecting advanced fibrosis. FIB-4 had the highest (0.678) diagnostic accuracy rate.
CONCLUSIONWe found that the calculation of NIS before liver biopsy, especially GPR and FIB-4, may be useful for predicting advanced fibrosis in cases with CHBI.
Face masks have an effect of preventing the spread of infectious diseases such as coronavirus disease 2019 (COVID-19). With these masks, it is primarily aimed to prevent the environment from being ...contaminated by the user. However, in the COVID-19 outbreak, many countries made it mandatory to use masks in areas with high human circulation such as marketplaces, shopping malls and hospitals, and then in all areas outside the home. Some tests such as filtration efficiency, microbial load, resistance to body fluids, flammability and breathability are performed to determine the protection potential and wearing comfort of face masks. In this study, we investigated the bacterial filtration efficiency (%), microbial load (cfu/g), breathability (Pa/cm
2
) and air permeability values of five different face masks obtained by combining polypropylene (PP) nonwoven layers in different weights (accordance with EN 14683:2019 + AC:2019, EN ISO 11737-1:2018 and TS 391 EN ISO 9237 Standards). The surface morphologies of the nonwoven fabrics were characterized by scanning electron microscope (SEM). It was observed that the weight change in spunbond masks (1-4) was directly proportional to bacterial filtration efficiency and differential pressure, and inversely proportional to air permeability. In addition, SEM analysis showed that the average fiber diameter of the meltblown layer was at least 5.80 times smaller than the spunbond layers, and as a result, dramatic differences were also observed in the air permeability and differential pressure values of the Spunbond-Meltblown-Spunbond (SMS) mask (5) compared to spunbond masks.
Crimean Congo hemorrhagic fever (CCHF) is a viral zoonotic disease with high mortality rate. There are only a few studies on viral load in CCHF. In our study, we revealed the dynamics of viral load ...and its relationship with mortality in early phase of the disease. A total of 138 serum samples were collected from 23 patients. All patients had positive PCR for CCHF on admission. Serum samples were obtained daily from all patients for the first 6 days of hospitalization and stored at −80°C for viral load measurement. We found statistically significant difference between mean number of viremic serum samples of fatal and non‐fatal patients. Furthermore, non‐fatal cases' viral loads demonstrated statistically significant decreases over time; however, we could not observe a similar trend in viral loads of fatal cases. Limited number of studies on CCHF indicate that score of the contest between CCHF virus and immune system determines the survival in CCHF and viral load is found to be the most prognostic factor. In our study, we found that there is a notable decrease trend in viral loads of non‐fatal patients over time and this clearance of CCHF virus is significantly related with survival.
The Mesoarchean (ca. 3075 Ma) Ivisaartoq greenstone belt contains well-preserved primary magmatic structures, such as pillow lavas, volcanic breccias, and clinopyroxene cumulate layers (picrites), ...despite the isoclinal folding and amphibolite facies metamorphism. The belt also includes variably deformed gabbroic to dioritic dykes and sills, actinolite schists, and serpentinites. The Ivisaartoq rocks underwent at least two stages of post-magmatic metamorphic alteration, including seafloor hydrothermal alteration and syn- to post-tectonic calc-silicate metasomatism, between 3075 and 2961 Ma. These alteration processes resulted in the mobilization of many major and trace elements. The trace element characteristics of the least altered rocks are consistent with a supra-subduction zone geodynamic setting and shallow mantle sources. On the basis of geological similarities between the Ivisaartoq greenstone belt and Phanerozoic forearc ophiolites, and intra-oceanic island arcs, we suggest that the Ivisaartoq greenstone belt represents a relic of dismembered Mesoarchean supra-subduction zone oceanic crust. This crust might originally have been composed of a lower layer of leucogabbros and anorthosites, and an upper layer of pillow lavas, picritic flows, gabbroic to dioritic dykes and sills, and dunitic to wehrlitic sills.
The Sm–Nd and U–Pb isotope systems have been disturbed in strongly altered actinolite schists. In addition, the U–Pb isotope system in pillow basalts appears to have been partially open during seafloor hydrothermal alteration. Gabbros and diorites have the least disturbed Pb isotopic compositions. In contrast, the Sm–Nd isotope system appears to have remained relatively undisturbed in picrites, pillow lavas, gabbros, and diorites. As a group, picrites have more depleted initial Nd isotopic signatures (
ε
Nd
=
+
4.23 to +
4.97) than pillow lavas, gabbros, and diorites (
ε
Nd
=
+
0.30 to +
3.04), consistent with a variably depleted, heterogeneous mantle source.
In some areas gabbros include up to 15 cm long white inclusions (xenoliths). These inclusions are composed primarily (>
90%) of Ca-rich plagioclase and are interpreted as anorthositic cumulates brought to the surface by upwelling gabbroic magmas. The anorthositic cumulates have significantly higher initial
ε
Nd (+
4.8 to +
6.0) values than the surrounding gabbroic matrix (+
2.3 to +
2.8), consistent with different mantle sources for the two rock types.
Oceanic rocks in the Ankara Mélange along the Izmir–Ankara–Erzincan suture zone (IAESZ) in north-central Anatolia include locally coherent ophiolite complexes (~ 179 Ma and ~ 80 Ma), seamount or ...oceanic plateau volcanic units with pelagic and reefal limestones (96.6 ± 1.8 Ma), metamorphic rocks with ages of 256.9 ± 8.0 Ma, 187.4 ± 3.7 Ma, 158.4 ± 4.2 Ma, and 83.5 ± 1.2 Ma indicating northern Tethys during the late Paleozoic through Cretaceous, and subalkaline to alkaline volcanic and plutonic rocks of an island arc origin (~ 67–63 Ma). All but the arc rocks occur in a shale–graywacke and/or serpentinite matrix, and are deformed by south-vergent thrust faults and folds that developed in the middle to late Eocene due to continental collisions in the region. Ophiolitic volcanic rocks have mid-ocean ridge (MORB) and island arc tholeiite (IAT) affinities showing moderate to significant large ion lithophile elements (LILE) enrichment and depletion in Nb, Hf, Ti, Y and Yb, which indicate the influence of subduction-derived fluids in their melt evolution. Seamount/oceanic plateau basalts show ocean island basalt (OIB) affinities. The arc-related volcanic rocks, lamprophyric dikes and syenodioritic plutons exhibit high-K shoshonitic to medium- to high-K calc-alkaline compositions with strong enrichment in LILE, rare earth elements (REE) and Pb, and initial εNd values between +1.3 and +1.7. Subalkaline arc volcanic units occur in the northern part of the mélange, whereas the younger alkaline volcanic rocks and intrusions (lamprophyre dikes and syenodioritic plutons) in the southern part. The late Permian, Early to Late Jurassic, and Late Cretaceous amphibole-epidote schist, epidote-actinolite, epidote-chlorite and epidote-glaucophane schists represent the metamorphic units formed in a subduction channel in the northern Neotethys. The Middle to Upper Triassic neritic limestones spatially associated with the seamount volcanic rocks indicate that the northern Neotethys was an open ocean with its MORB-type oceanic lithosphere by the early Triassic (or earlier). The latest Cretaceous–early Paleocene island arc volcanic, dike and plutonic rocks with subalkaline to alkaline geochemical affinities represent intraoceanic magmatism that developed on and across the subduction–accretion complex above a N-dipping, southward-rolling subducted lithospheric slab within the northern Neotethys. The Ankara Mélange thus exhibits the record of ~ 120–130 million years of oceanic magmatism in geological history of the northern Neotethys.
Mount Olympos on the border of Thessaly and Central Macedonia (Greece) is the namesake of many mountains over the Earth and even on Mars. The inspiration of Olympos to humanity dates from the ...earliest settlements of modern peoples at its base (~ 40,000 years BP) who were witnesses to a period of on-going active glaciation; these inhabitants would have endured the environmental consequences of proximity to the eruption of Thira (Santorini, 1646 BCE); possibly, they also observed a meteor impact. These geologic events can be interpreted from descriptions of activities attributed to the gods in Hesiod’s Theogeny (~ 750 BCE). The incorporation of the mythology of Olympos into the epic tales of Homer and the “Greek Miracle” created a worldview that is significant to the evolution of Western civilization. The geological history of Olympos is perhaps as legendary as its mythology. From a carbonate platform on the Apulian (African) plate with active deposition from the Triassic to Eocene, the rocks of future Olympos were subducted beneath the Pangaean-originated European plate and were then exhumed later in the Cenozoic; the exhumation contact is marked by a ring of blueschist facies rocks and mafic–ultramafic rocks as a remnant of oceanic lithosphere (ophiolitic rocks) at the surface. Cobbles eroded from this exhuming complex found their way to Miocene fluvial depocenters, forming conglomerate formations of Meteora, located ~ 70 km to the SW. Continued uplift of Olympos has created rivers that were considered sacred to the ancient societies, and that contributed to the immense late-Pleistocene cataclysmic release of waters from the inland basin of Thessaly, forming the Vale of Tempe between the mountain of the Olympian gods and Mount Ossa of the Titans. Olympos comprises the oldest National Park of Greece and a UNESCO Biosphere Reserve. Despite the significance of Olympos as part of the bedrock of western cultural heritage, as well as the physical geomorphology of Greece, it has yet to be recognized as a UNESCO World Heritage site.
The Ivisaartoq (ca. 3075 Ma) and Ujarassuit (ca. 3070 Ma) greenstone belts are the largest Mesoarchean supracrustal lithotectonic assemblages in the Nuuk region, SW Greenland. Both greenstone belts ...underwent polyphase deformation and amphibolite facies metamorphism, and were in due course variously dismembered. Pillow lavas, pillow breccia, magmatic layering, and relic sedimentary structures are well preserved in the Ivisaartoq belt. Volcanic rocks include basalts, and minor andesites and picrites. Boninite-like rocks occur in the Ujarassuit belt. Metasedimentary rocks in the Ujarassuit belt occur as thin layers (0.5–1.0 m) of biotite schists, and in the Ivisaartoq belt as ~
500 m-thick biotite schists intercalated with minor quartzitic gneisses. There is no field evidence indicating that the Ivisaartoq and Ujarassuit supracrustal rocks were deposited on older continental basement, and their volcanic rocks do not exhibit any geochemical trends indicating contamination by Archean upper continental crust.
Four groups of amphibolites (metavolcanic rocks) were recognized in the Ujarassuit greenstone belt on the basis of their REE and HFSE characteristics: (1) Group 1 is characterized by near-flat REE patterns (La/Sm
cn
=
0.77–1.14; La/Yb
cn
=
0.84–1.24) and moderate negative Nb anomalies (Nb/Nb⁎
=
0.60–0.79); (2) Group 2 displays LREE-depleted patterns (La/Sm
cn
=
0.53–1.02; La/Yb
cn
=
0.32–0.61) and pronounced negative Nb anomalies (Nb/Nb
⁎
= 0.32–0.67); (3) Group 3 consists of LREE depleted patterns (La/Sm
cn
=
0.69–0.84; La/Yb
cn
=
0.55–0.91) and absence of significant Nb anomalies (Nb/Nb⁎
=
0.92–1.15); and (4) Group 4 has concave-upward REE patterns (La/Sm
cn
=
1.64–2.42, Gd/Yb
cn
=
0.57–1.01) and large negative Nb anomalies (Nb/Nb
⁎
=
0.28–0.42). The depletion of LREE in Group 2 amphibolites appears to have resulted from mobility of these elements during metamorphism. Group 1, 3, and 4 amphibolites retain their near-primary geochemical signatures and their trace element patterns are comparable to those of Phanerozoic oceanic island arc tholeiites (IAT), normal-mid-ocean ridge basalts (N-MORB), and boninites, respectively. The trace element patterns of the least altered meta-ultramafic rocks (La/Yb
cn
=
2.48–1.35; Nb/Nb⁎
=
0.31–0.60) are comparable to those of modern subduction-related picrites. Amphibolites with an andesitic composition show large negative Nb anomalies (Nb/Nb⁎
=
0.21–0.55), enriched LREE patterns (La/Yb
cn
=
6.29–15.64), and fractionated HREE (Gd/Yb
cn
=
2.61–3.12) implying deep melting in equilibrium with residual garnet in the source. Biotite schists and quartzitic gneisses have low chemical indexes of alteration values (CIA
=
46 to 62) and trace element characteristics indicating volcaniclastic sedimentary protoliths derived from poorly weathered felsic to mafic source rocks. Collectively, the geochemical features of metavolcanic and metasedimentary rocks suggest that the Ivisaartoq and Ujarassuit greenstone belts represent dismembered fragments of Mesoarchean supra-subduction zone oceanic crust formed in an arc-forearc-backarc tectonic setting.
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