crystal accumulation
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Geology ◽  
2021 ◽  
Author(s):  
Tian-Yu Lu ◽  
Zhen-Yu He ◽  
Reiner Klemd

High-silica (<70 wt% SiO2) magmas are usually believed to form via shallow crustal–level fractional crystallization of intermediate magmas. However, the broad applicability of this model is controversial, because the required crystal-melt separation processes have rarely been documented globally up to now. The ca. 50 Ma Nyemo composite pluton of the Gangdese batholith belt in southern Tibet, which comprises intrusive rocks with intermediate- to high-silica compositions (65–78 wt%), offers a unique opportunity for substantiating the coexistence of extracted melts and complementary silicic cumulates in one of Earth’s most complete transcrustal silicic magmatic systems. The Nyemo pluton intrusive rocks exhibit similar zircon Hf isotopic compositional ranges (mean εHf(t) = +5.7 to +8.3), suggesting a common, non-radiogenic magma source with crustal assimilation in the deep crust. Yet, these rocks have distinct geochemical characteristics. High-silica miarolitic and rapakivi granites are strongly depleted in Ba, Sr, and Eu, and their zircon trace elements show extremely low Eu/Eu* and Dy/Yb. In contrast, monzogranite is relatively enriched in Ba and Sr with minor Eu anomalies, and the zircon trace elements are characterized by relatively high Eu/Eu* and Dy/Yb. Therefore, we propose that the high-silica granites represent highly fractionated melt extracted from a mush reservoir at unusually low storage pressure (~99–119 MPa), and that the monzogranite constitutes the complementary residual silicic cumulates.


2021 ◽  
Author(s):  
Tian-Yu Lu ◽  
Zhen-Yu He ◽  
et al.

Analytical methods, modeling setup for magmatic evolution, and data.


2021 ◽  
Author(s):  
Tian-Yu Lu ◽  
Zhen-Yu He ◽  
et al.

Analytical methods, modeling setup for magmatic evolution, and data.


2021 ◽  
Author(s):  
Tian-Yu Lu ◽  
Zhen-Yu He ◽  
et al.

Analytical methods, modeling setup for magmatic evolution, and data.


Author(s):  
Mehrdad Goudarzi ◽  
Maryam Eskandari Mehrabadi ◽  
Zahra Salemi ◽  
Jamal Amri ◽  
Mitra Noori ◽  
...  

We want to evaluate the effect of Allium noeanum Reut. ex Regel (Bonsor) known (traditional medicine agent) in calcium oxalate stones in kidney. 36 male rats were divided into 6 groups. I: healthy model + water, II: negative model + 1% ethylene glycol in water, III: 750 mg/kg of total extract +1% of ethylene glycol in water(Prevention), IV: 250 mg/kg flavonoid extract +1% of ethylene glycol in water (Prevention), V: 1500 mg/kg of total extract from 15th day+ 1% of ethylene glycol in water (Treatment), VI: 500 mg/kg of flavonoid extract from 15th of the study + 1% of ethylene glycol in water (Treatment).24-hour urine and blood samples were collected in 30th day for analysis. Pathology of kidneys was checked. Serum urea, uric acid, creatinine and urine calcium and oxalate were significantly increased, urine citrate was decreased in group II Vs I. (P < .05). Extract administration significantly decreased serum creatinine, urea and uric acid. Urine calcium and oxalate significantly decreased in treated groups. Urine calcium levels were significantly decreased in treated rats, but urine citrate levels were increased Vs group II. (P < .05). No crystal accumulation and tubular cast were observed in prevention groups. Hydroalcholic extract of Allium noeanum was able to reduce urine oxalate.


Geology ◽  
2021 ◽  
Author(s):  
Teresa Ubide ◽  
Patricia Larrea ◽  
Laura Becerril ◽  
Carlos Galé

Ocean-island basalts (OIBs) are considered to be messengers from the deep mantle, yet the filtering effect of the plumbing systems that bring OIB melts to the surface remains poorly assessed. We investigated volcanic products from El Hierro island (Canary Islands) from textural and chemical perspectives. The majority of geochemical data cluster at relatively fractionated basaltic compositions of 5 wt% MgO. Compositions ≥10 wt% MgO are porphyritic whole rocks that accumulate mafic minerals. Near-primary melts do not erupt. Instead, we show that carrier melts (crystal-free whole rocks, glasses, and melt inclusions) are consistently buffered to low-MgO compositions during passage through the plumbing system. We tested our model of melt fractionation and crystal accumulation on a global compilation of OIBs. Similar to El Hierro, the majority of data cluster at evolved compositions of 5 wt% MgO (alkaline) to 7 wt% MgO (tholeiitic). Modeling the fractionation of OIB parental melts, we show that with 50% crystallization, OIB melts reach 5 wt% MgO with reduced density, increased volatile content, and overall low viscosity, becoming positively buoyant relative to wall rocks and highly eruptible when reaching volatile saturation at depths around the crust-mantle boundary. Under these conditions, 5 wt% MgO OIB “sweet spot” melts are propelled to the surface and erupt carrying an assortment of recycled crystals. This mechanism is consistent with the petrography and chemistry of erupted products and suggests OIB volcanoes are dominated by low-MgO basaltic melts.


Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1787
Author(s):  
Olman Gómez-Espinoza ◽  
Daniel González-Ramírez ◽  
Jairo Méndez-Gómez ◽  
Rossy Guillén-Watson ◽  
Alejandro Medaglia-Mata ◽  
...  

The presence of calcium oxalate (CaOx) crystals has been widely reported in the plant kingdom. These structures play a central role in various physiological functions, including calcium regulation, metal detoxification, and photosynthesis. However, precise knowledge about their possible roles and functions in plants is still limited. Therefore, the present work aims to study the ecotypic variability of Colobanthus quitensis, an extremophile species, concerning CaOx crystal accumulation. The CaOx crystals were studied in leaves of C. quitensis collected from different provenances within a latitudinal gradient (From Andes mountains in central Chile to Antarctica) and grown under common garden conditions. Polarized light microscopy, digital image analysis, and electron microscopy were used to characterize CaOx crystals. The presence of CaOx crystals was confirmed in the four provenances of C. quitensis, with significant differences in the accumulation among them. The Andean populations presented the highest accumulation of crystals and the Antarctic population the lowest. Electron microscopy showed that CaOx crystals in C. quitensis are classified as druses based on their morphology. The differences found could be linked to processes of ecotypic differentiation and plant adaptation to harsh environments.


Author(s):  
Robert Gosik ◽  
Krzysztof Danel

: It is estimated that by 2040 Chronic Kidney Disease (CKD) will be the 5th main cause of global deaths. It has been suggested that hyperphosphatemia is among the main factors leading to the increased risk of death. This review focuses on potential and currently used phosphate binders (PB). Aluminum hydroxide is presently not recommended due to potential aluminum toxicity. Calcium‑containing phosphate binders (CCPB) can cause calcium overload, resulting in hypercalcemia and an increased risk of cardiovascular diseases. Magnesium and calcium complexes were suggested to be as effective as sevelamer in the reduction of serum phosphate, with the potential to slow down the process of calcification. However, limited studies have been conducted in this area. Although sevelamer seemed to have a positive influence on cardiovascular calcification and arterial stiffness, its influence on mortality was unclear. Sevelamer crystal accumulation in the gastrointestinal tract (GI) can cause gastrointestinal bleeding. Lanthanum carbonate seemed to lower all-cause mortality and reduce the chance of hypercalcemia, even though a deposit in the GI tract was observed. Colestilan, like sevelamer, lowered LDL cholesterol. Sucroferric oxyhydroxide had a lower pill burden than other PBs, and it seemed to reduce serum FGF-23. Ferric citrate improved parameters that are related to anemia but can cause iron overload. Bixalomer appeared to have fewer gastrointestinal side effects than sevelamer. Nano-lanthanum hydroxide and SBR759 may have an interesting future as PBs. In conclusion, the development of new PBs should also take into consideration their potential to function as protection modifiers.


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