Soft-sediment deformation structures in cores from lacustrine slurry deposits of the Late Triassic Yanchang Fm. (central China)

The fine-grained autochthonous sedimentation in the deep part of a Late Triassic lake was frequently interrupted by gravity-induced mass flows. Some of these mass flows were so rich in water that they must have represented slurries. This can be deduced from the soft-sediment deformation structures that abound in cores from these lacustrine deposits which constitute the Yanchang Fm., which is present in the Ordos Basin (central China). The flows and the resulting SSDS were probably triggered by earthquakes, volcanic eruptions, shear stress of gravity flows, and/or the sudden release of overburden-induced excess pore-fluid pressure. The tectonically active setting, the depositional slope and the high sedimentation rate facilitated the development of soft-sediment deformations, which consist mainly of load casts and associated structures such as pseudonodules and flame structures. Sediments with such deformations were occasionally eroded by slurries and became embedded in their deposits

The Paleocene Hangu formation : a key to unlocking the mysteries of Paleo-Tethys tectonism

DATA AVAILABILITY : Data will be made available on request.The sedimentary rocks of the Paleocene Hangu Formation in the Yadgaar Section of the Upper Indus Basin in northern Pakistan, have been the subject of an integrated field, petrographical, and sedimentological investigation. The goals of this study are to improve our understanding of the sedimentary environment, facies shifts, and the impact of tectonism on the genesis of the investigated sedimentary facies. A better understanding of the intricate relationships between the aforementioned factors will clarify whether the regional tectonic drive has partial control over or complete command of the sedimentation processes. The results of this study shows that the Hangu Formation consists of four facies: bauxite, sandstone, coal, and limestone. The bauxite deposits formed in a karst environment with severe chemical weathering in a humid to extremely humid climatic setting. Thin coal laminae indicate a peatland environment that formed within a humid tropical climate. Sub-arkose, arenite, and arkose sandstone facies mark deltaic (sub-humid), coastal–near shore (humid to hot-humid), and high-energy fluvial (arid to semi-arid) sedimentary environments, respectively. Finally, the occurrence of marly limestone points towards deposition on a shallow marine carbonate platform within a coastal-brackish environment. The facies shift of the sediments provides evidence for a gradual transition from continental to marine conditions within the study area, together with episodic transgressive and regressive cycles as well as changing climatic and geomorphological conditions. In consequence, all these changes are controlled and shaped by the effects of Paleo-Tethys tectonism during the Indo-Eurasian intra-oceanic subduction. This advancement through the current work helps in understanding tectonic-sedimentary mechanics, i.e., how regional tectono-sedimentological processes influence the formation of sedimentary sequences.The China-ASEAN Maritime Cooperation Fund Project and the National Natural Science Foundation of China.https://www.elsevier.com/locate/marpetgeo2024-09-22hj2023Geolog

Soft-sediment deformation structures in cores from lacustrine slurry deposits of the Late Triassic Yanchang Fm. (central China)

The fine-grained autochthonous sedimentation in the deep part of a Late Triassic lake was frequently interrupted by gravity-induced mass flows. Some of these mass flows were so rich in water that they must have represented slurries. This can be deduced from the soft-sediment deformation structures that abound in cores from these lacustrine deposits which constitute the Yanchang Fm., which is present in the Ordos Basin (central China)

Novel NARS2 variants in a patient with early-onset status epilepticus: case study and literature review

Abstract Background NARS2 as a member of aminoacyl-tRNA synthetases was necessary to covalently join a specific tRNA to its cognate amino acid. Biallelic variants in NARS2 were reported with disorders such as Leigh syndrome, deafness, epilepsy, and severe myopathy. Case presentation Detailed clinical phenotypes were collected and the NARS2 variants were discovered by whole exome sequencing and verified by Sanger sequencing. Additionally, 3D protein structure visualization was performed by UCSF Chimera. The proband in our study had early-onset status epilepticus with abnormal EEG and MRI results. She also performed global developmental delay (GDD) and myocardial dysfunction. Next-generation sequencing (NGS) and Sanger sequencing revealed compound heterozygous missense variants [NM_024678.6:exon14: c.1352G > A(p.Arg451His); c.707T > C(p.Phe236Ser)] of the NARS2 gene. The proband develops refractory epilepsy with GDD and hyperlactatemia. Unfortunately, she finally died for status seizures two months later. Conclusion We discovered two novel missense variants of NARS2 in a patient with early-onset status epilepticus and myocardial dysfunction. The NGS enables the patient to be clearly diagnosed as combined oxidative phosphorylation deficiency 24 (COXPD24, OMIM:616,239), and our findings expands the spectrum of gene variants in COXPD24

Dysregulated Expression and Methylation Analysis Identified TLX1NB as a Novel Recurrence Marker in Low-Grade Gliomas

Low-grade gliomas (LGGs) are the most common CNS tumors, and the main therapy for LGGs is complete surgical resection, due to its curative effect. However, LGG recurrence occurs frequently. Biomarkers play a crucial role in evaluating the recurrence and prognosis of LGGs. Numerous studies have focused on LGG prognosis. However, the multiomics research investigating the roles played by gene methylation and expression in LGG recurrence remains limited. In this study, we integrated the TCGA and GEO datasets, analyzing RNA and methylation data for recurrence (R) and nonrecurrence (NR) groups. We found a low expression of TLX1NB and high methylation in recurrence patients. Low expression of TLX1NB is associated with poor survival (OS: p=0.04). The expression of TLX1NB is likely to play a role in the prognosis of LGG. Therefore, TLX1NB may represent an alternative early biomarker for the recurrence of low-grade gliomas

Cementation and porosity evolution of tight sandstone reservoirs in the Permian Sulige gas field, Ordos Basin (central China)

Tight sandstone gas reservoirs constitute an important type of unconventional gas resources and may be of crucial significance as environment-friendly source of energy in the world. However, the dynamics of densification and evolution of the low-porosity and low-permeability sandstone reservoirs are intensively debated in literature. Recently, the question of sequence of reservoir densification and hydrocarbon accumulation has arisen. A typical tight sandstone reservoir (the first member of the Shanxi Formation and the eighth member of Shihezi Formation) in the Permian Sulige gas field in Central China provides an excellent case study to probe these questions. By using a variety of different methodologies such as scanning electron microscopy (SEM), X-ray diffraction (XRD), cathodoluminescence, fluid inclusion analysis and confocal Raman spectrometer analysis, we identified different authigenic minerals such as illite, kaolinite, dickite, chlorite and smectite illitization coexisting with siliceous and calcitic cements. These authigenic minerals precipitated at different diagenetic stages, related to the changing conditions during compaction and lithification, and therefore, changed the porosities of the host rocks during each of these stages. The types of pores in the Sulige gas field are dominated by illite and kaolinite intercrystalline pores, matrix solution pores, and primary intergranular pores. The results of this study suggest that compaction and cementation are the reasons for the most distinct loss in porosity. On the other hand, kaolinite and illite preserve their intercrystalline pores, which could be identified as the main reserve space of the tight gas reservoirs. Therefore, the secondary porosity of the sandstone reservoirs forms the most important contributor to the gas reservoir potential in the Sulige gas field. In addition, it could be inferred that the tight gas accumulation took place during the densification of the reservoirs. The implications of the presented results may also help to understand the formation of other tight reservoirs world-wide.The National Natural Science Foundation of China (grant No. 41402120), and Shandong University of Science and Technology Research Fund, China (grant No. 2015TDJH101).http://www.elsevier.com/locate/marpetgeo2020-05-01hj2020Geolog

Additional file 1 of Novel NARS2 variants in a patient with early-onset status epilepticus: case study and literature review

Additional file 1: Supplementary Table 1. The candidate pathogenic genes variants in our patient

Homozygous variant of MLC1 results in megalencephalic leukoencephalopathy with subcortical cysts

Abstract Background Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare, inherited disorder that causes epilepsy, intellectual disorders, and early onset macrocephaly. MLC1 has been identified as a main pathogenic gene. Methods Clinical data such as magnetic resonance imaging (MRI), routine blood tests, and physical examinations were collected from proband. Trio whole‐exome sequencing (WES) of the family was performed, and all variants with a minor allele frequency (<0.01) in the exon and canonical splicing sites were selected for further pathogenic evaluation. Candidate variants were validated using Sanger sequencing. Results Here, we report a new homozygous variant identified in two children from the same family in the MLC1 gene [NM_015166.4: c.838_843delinsATTTTA, (p.Ser280_Phe281delinsIleLeu)]. This variant is classified as variant of uncertain significance (VUS) according to the ACMG guidelines. Further experiments demonstrate that the newly identified variant causes a decrease of MLC1 protein levels when expressed in a heterologous expression system. Conclusion Our case expands on this genetic variation and provides new evidence for the clinical diagnosis of MLC1‐related MLC