highly evolved
Recently Published Documents


TOTAL DOCUMENTS

280
(FIVE YEARS 60)

H-INDEX

32
(FIVE YEARS 4)

2022 ◽  
Author(s):  
Yongsen Ruan ◽  
Mei Hou ◽  
Xiaolu Tang ◽  
Xionglei He ◽  
Xuemei Lu ◽  
...  

In new epidemics after the host shift, the pathogens may experience accelerated evolution driven by novel selective pressures. When the accelerated evolution enters a positive feedback loop with the expanding epidemics, the pathogen's runaway evolution may be triggered. To test this possibility in COVID-19, we analyze the extensive databases and identify 5 major waves of strains, one replacing the previous one in 2020-2021. The mutations differ entirely between waves and the number of mutations continues to increase, from 3-4 to 21-31. The latest wave is the Delta strain which accrues 31 new mutations to become highly prevalent. Interestingly, these new mutations in Delta strain emerge in multiple stages with each stage driven by 6-12 coding mutations that form a fitness group. In short, the evolution of SARS-CoV-2 from the oldest to the youngest wave, and from the earlier to the later stages of the Delta wave, is a process of acceleration with more and more mutations. The global increase in the viral population size (M(t), at time t) and the mutation accumulation (R(t)) may have indeed triggered the runaway evolution in late 2020, leading to the highly evolved Alpha and then Delta strain. To suppress the pandemic, it is crucial to break the positive feedback loop between M(t) and R(t), neither of which has yet to be effectively dampened by late 2021. New waves beyond Delta, hence, should not be surprising.


2021 ◽  
Author(s):  
Yufei Xiang ◽  
Wei Huang ◽  
Hejun Liu ◽  
Zhe Sang ◽  
Sham Nambulli ◽  
...  

Vaccine boosters and infection can facilitate the development of SARS-CoV-2 antibodies with improved potency and breadth. Here, we observed super-immunity in a camelid extensively immunized with the SARS-CoV-2 receptor-binding domain (RBD). We rapidly isolated a large repertoire of specific ultrahigh-affinity nanobodies that bind strongly to all known sarbecovirus clades using integrative proteomics. These pan-sarbecovirus nanobodies (psNbs) are highly effective against SARS-CoV and SARS-CoV-2 variants including the Omicron, with the best median neutralization potency at single-digit ng/ml. Structural determinations of 13 psNbs with the SARS-CoV-2 spike or RBD revealed five epitope classes, providing insights into the mechanisms and evolution of their broad activities. The highly evolved psNbs target small, flat, and flexible epitopes that contain over 75% of conserved RBD surface residues. Their potencies are strongly and negatively correlated with the distance of the epitopes to the receptor binding sites. A highly potent, inhalable and bispecific psNb (PiN-31) was developed. Our findings inform on the development of broadly protective vaccines and therapeutics.


MicroRNA ◽  
2021 ◽  
Vol 11 ◽  
Author(s):  
Alberto Izzotti

Abstract: Despite their biological simplicity, microRNA-based organisms, such as RNA viruses, are currently shown to be unexpected threats to mammals, including humans. This situation is exemplified by the COVID-19 pandemic triggered by the spread of SARS-CoV-2. RNA viruses are older than DNA viruses. Indeed, from an evolutionary standpoint, RNA is an older molecule than DNA. The strength of RNA viruses, compared to DNA viruses, resides in their simplicity and instability. The instability of RNA viruses, such as human immunodeficiency virus (HIV) and flu viruses, generates mutants to escape the host’s defense mechanisms. A formidable combination of lethality and infectivity was recently achieved by SARS-CoV-2. Complex DNAbased defense systems use Toll-like receptors to intercept viral RNA inside a cell. Activation of Toll-like receptors triggers inflammation and activates lymphocytes and monocytes, causing thromboxane release. In the case of SARS-CoV-2 infection, this process results in cytokine storms and lung thromboembolism. The ongoing pandemic can be envisioned as a struggle between highly evolved complex DNA organisms, i.e., humans, and poorly evolved simple RNA organisms, i.e., SARS-CoV-2 virus. Quite surprisingly, the complex organism has a serious problem defeating the simplistic organism. However, humans are finally developing a new effective weapon in fighting the SARS-CoV-2 virus, paradoxically, RNA-based vaccines. These considerations underscore the relevance of microRNAs as powerful tools in therapeutic and preventive medicine.


Geology ◽  
2021 ◽  
Author(s):  
Panlao Zhao ◽  
Xu Chu ◽  
Anthony E. Williams-Jones ◽  
Jingwen Mao ◽  
Shunda Yuan

Most tungsten (W) and tin (Sn) deposits are associated with highly evolved granites derived from the anatexis of metasedimentary rocks. They are commonly separated in both space and time, and in the rare cases where the W and Sn mineralization are part of a single deposit, the two metals are temporally separate. The factors controlling this behavior, however, are not well understood. Our compilation of whole-rock geochemical data for W- and Sn-related granites in major W-Sn metallogenic belts shows that the Sn-related granites are generally the products of higher-temperature partial melting (~800 °C) than the W-related granites (~750 °C). Thermodynamic modeling of partial melting and metal partitioning shows that W is incorporated into the magma formed during low-temperature muscovite-dehydration melting, whereas most of the Sn is released into the magma at a higher temperature during biotite-dehydration melting; the Sn of the magma may be increased significantly if melt is extracted prior to biotite melting. At the same degree of partial melting, the concentrations of the two metals in the partial melt are controlled by their concentration in the protolith. Thus, the nature of the protolith and the melting temperature and subsequent evolution of the magma all influence the metallogenic potential of a magma and, in combination, helped control the spatial and temporal segregation of W and Sn deposits in all major W-Sn metallogenic belts.


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 724
Author(s):  
Anna A. Nosova ◽  
Ludmila V. Sazonova ◽  
Alexey V. Kargin ◽  
Elena O. Dubinina ◽  
Elena A. Minervina

The study reports petrography, mineralogy and carbonate geochemistry and stable isotopy of various types of ocelli (silicate-carbonate globules) observed in the lamprophyres from the Chadobets Uplift, southwestern Siberian craton. The Chadobets lamprophyres are related to the REE-bearing Chuktukon carbonatites. On the basis of their morphology, mineralogy and relation with the surrounding groundmass, we distinguish three types of ocelli: carbonate-silicate, containing carbonate, scapolite, sodalite, potassium feldspar, albite, apatite and minor quartz ocelli (K-Na-CSO); carbonate–silicate ocelli, containing natrolite and sodalite (Na-CSO); and silicate-carbonate, containing potassium feldspar and phlogopite (K-SCO). The K-Na-CSO present in the most evolved damtjernite with irregular and polygonal patches was distributed within the groundmass; the patches consist of minerals identical to minerals in ocelli. Carbonate in the K-Na-CSO are calcite, Fe-dolomite and ankerite with high Sr concentration and igneous-type REE patterns. The Na-CSO present in Na-rich damtjernite with geochemical signature indicates the loss of the carbonate component. Carbonate phases are calcite and Fe-dolomite, and they depleted in LREE. The K-SCO was present in the K-rich least-evolved damtjernite. Calcite in the K-SCO has the highest Ba and the lowest Sr concentration and U-shaped REE pattern. The textural, mineralogical and geochemical features of the ocelli and their host rock can be interpreted as follows: (i) the K-Na-CSO are droplets of an alkali–carbonate melt that separated from residual alkali and carbonate-rich melt in highly evolved damtjernite; (ii) the Na-CSO are droplets of late magmatic fluid that once exsolved from a melt and then began to dissolve; (iii) the K-SCO are bubbles of K-P-CO2 fluid liberated from an almost-crystallised magma during the magmatic–hydrothermal stage. The geochemical signature of the K-SCO carbonate shows that the late fluid could leach REE from the host lamprophyre and provide for REE mobility.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Zhi ◽  
Ruxiong Lei ◽  
Boyang Chen ◽  
M. N. Muhtar ◽  
Zhijie Feng ◽  
...  

The Zhangbaoshan (ZBS) super-large Rubidium deposit, located in the Eastern Tianshan, is a typical granite-type Rb deposit. The ZBS deposit is mainly hosted in the highly evolved Baishitouquan (BST) pluton enriched in F and Rb, which exhibits five lithological zones from the bottom to the top: leucogranite (zone-a), amazonite-bearing granite (zone-b), amazonite granite (zone-c), topaz-bearing amazonite granite (zone-d) and topaz albite granite (zone-e), as well as minor small lodes of amazonite pegmatite. Two types of zircon were identified from the BST pluton. Type-I zircons mainly occur in the zone–a, are characterized by obvious oscillatory zoning, high Zr contents (47.4–67.3 wt% ZrO2) and Zr/Hf ratios (21.72–58.23), low trace element concentrations, and heavy rare earth elements (HREE)–enriched patterns with prominent positive Ce anomalies (Ce/Ce* = 1.21–385) and strong negative Eu anomalies (Eu/Eu* = 0.008–0.551), indicative of early magmatic zircon. Type–II zircons mainly occur in the upper zones (zone-c to zone-e), exhibit porous and dark Cathodoluminescence images, inhomogeneous internal structure, plenty of mineral inclusions, low Zr (38.7–51.0 wt% ZrO2) and Zr/Hf ratios (3.35–11.00), high Hf (34,094–85,754 ppm), Th (718–4,980 ppm), U (3,540–32,901 ppm), Ta (86.7–398 ppm), Y (1,630–28,890 ppm) and rare earth elements (REEs) (3,910–30,165 ppm), as well as slightly HREE–enriched patterns and significant M–type tetrad patterns with t3 values (quantification factor of tetrad effect) of 1.51–1.69. It is suggested that the type–II zircons are crystallized from a deuteric F–rich fluid coexisted with the highly evolved residual magma during the transition from the magmatic to the F–rich hydrothermal stage of the BST pluton. The F–rich fluid exsolution during the magmatic–hydrothermal transition is one of the most important factors controlling the modification of highly evolved granite and related Rb enrichment and mineralization. The type–I zircon samples from zone–a yield concordant ages of 250 ± 2.5 Ma and 250.5 ± 1.7 Ma, respectively, indicating that the BST pluton was emplaced in the Early Triassic. The type–II zircons from zone–c to zone–e yield lower intercept U–Pb ages between 238 and 257 Ma, which may represent the age of F–rich fluid–melt interaction during the transition from the magmatic to the hydrothermal stage. The mineralization of the ZBS super–large Rb deposit should have occurred shortly after emplacement of the BST pluton in the Early Triassic. Combined with available data, it is suggested that the Triassic is an important period for granitic magmatism and rare metal metallogeny in the Eastern Tianshan.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 578
Author(s):  
Sandra Fernández-Landero ◽  
Juan Carlos Fernández-Caliani

Glaucony is a significant green marine facies in the northwestern passive margin of the Guadalquivir Basin (Spain), where glauconite formed authigenically on a sediment-starved continental shelf, with fecal pellets and benthic foraminiferal tests being the main glauconitized substrates. Results from a study using XRD, TGA-DSC, SEM-EDS, and EPMA have revealed that glauconite is remarkably heterogeneous in mineral composition and chemical maturity, even in a single grain, reflecting a complex interaction of micro-environmental factors, substrate influences and post-depositional alterations. In its early stage, the glauconitization process is consistent with the slow precipitation of a Fe-rich smectite phase, most likely intergrade between nontronite and Fe-montmorillonite end-members, which evolved to a regularly interstratified glauconite-smectite (Gl/S). The Fe-smectite-to-Gl/S transformation is interpreted as a diffusion-controlled reaction, involving sufficient Fe availability in pore water and the constant diffusive transport of seawater K+ and Mg2+ ions towards the substrate. The pelletal glauconite is actually a highly evolved Gl/S consisting almost totally of mica layers, with 0.74 ± 0.05 apfu of K+ in the interlayer, while the Gl/S occurring as replacements of foraminiferal tests contains a mean of 7% of expandable layers in the walls and 16% in the chamber fillings, due to rate-limited ion diffusion.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Alexey Vladimirovich Kargin ◽  
Anna Andreevna Nosova ◽  
Ludmila Vyacheslavovna Sazonova ◽  
Vladimir Vasilievich Tretyachenko ◽  
Yulia Olegovna Larionova ◽  
...  

To provide new insights into the evolution of kimberlitic magmas, we have undertaken a detailed petrographic and mineralogical investigation of highly evolved carbonate–phlogopite-bearing kimberlites of the Kepino cluster, Arkhangelsk kimberlite province, Russia. The Kepino kimberlites are represented by volcanoclastic breccias and massive macrocrystic units within pipes as well as coherent porphyritic kimberlites within sills. The volcanoclastic units from pipes are similar in petrography and mineral composition to archetypal (Group 1) kimberlite, whereas the sills represent evolved kimberlites that exhibit a wide variation in amounts of carbonate and phlogopite. The late-stage evolution of kimberlitic melts involves increasing oxygen fugacity and fluid-phase evolution (forming carbonate segregations by exsolution, etc.). These processes are accompanied by the transformation of primary Al- and Ti-bearing phlogopite toward tetraferriphlogopite and the transition of spinel compositions from magmatic chromite to magnesian ulvöspinel and titanomagnetite. Similar primary kimberlitic melts emplaced as sills and pipes may be transitional to carbonatite melts in the shallow crust. The kimberlitic pipes are characterised by low carbonate amounts that may reflect the fluid degassing process during an explosive emplacement of the pipes. The Kepino kimberlite age, determined as 397.3 ± 1.2 Ma, indicates two episodes of ultramafic alkaline magmatism in the Arkhangelsk province, the first producing non-economic evolved kimberlites of the Kepino cluster and the second producing economic-grade diamondiferous kimberlites.


Author(s):  
Bianca Pizzorno Backx

Materials science seeks the development of new materials with optimized characteristics. The union of various areas as chemistry, physics, nanotechnology, biology, and medicine catalyzes news materials. Smart materials react to external stimuli by modifying their chemical, mechanical, magnetic, optical, electrical, thermal properties. They have superior efficiency to the materials currently available and promise many advantages to their consumers. However, smart materials must be associated with sustainable technological progress. As a result of highly evolved technologies and intense laboratory research, their final characteristics must be connected with sustainable protocols. In addition to a significant difference associated with a wide application in various areas as textile industry, construction, medicine, drugs delivery, microorganisms’ detection, smart materials must not pollute from production to disposal, and more than that, they must seek compensation for the harmful effects of this evolution on nature. In this way, smart materials will be an excellent advantage for the future and the environment.


Sign in / Sign up

Export Citation Format

Share Document