The timing of initial collision between India and Asia has remained controversial for half a century. This paper attempts to review this crucial and hotly debated argument, describing first the ...different methods used to constrain the age of collision and discussing next the rationale, results, inferences and problems associated with each. We conclude that stratigraphy represents the best direct way to unravel collision chronology. Other methods focusing on the magmatic, metamorphic or paleomagnetic record provide additional fundamental constraints, but cannot provide a robust direct estimate of collision onset.
Initial collision in the central-eastern Himalaya is dated directly at the middle Paleocene (59±1Ma) by the abrupt change in sediment provenance recorded in trench settings. The quasi-synchronous unconformities documented along both Tethyan passive margin of India and active margin of Asia from Tibet to Zanskar-Ladakh confirm that orogeny was underway at the close of the Paleocene (56Ma), well before the disappearance of marine seaways in the Himalaya during the early-middle Eocene (50–45Ma). Sedimentary evolution and provenance changes in marine to fluvio-deltaic successions are recorded synchronously within error from the western to the central-eastern Himalaya, failing to provide conclusive evidence for diachronous collision.
These coherent observations are hard to reconcile with three widely cited hypotheses invoking either Paleogene arc-continent collision or Late Cretaceous ophiolite obduction, or the protracted existence of a Greater India Basin, which are all not favored after discussing the geological evidence critically point by point. A scenario no more complex than the one involving solely the passive continental margin of India and the active continental margin of Asia is needed to explain the geological evolution of the nascent Himalaya. The collision between the Tethys Himalaya and the Transhimalayan arc-trench system does represent the collision between India and Asia. Because the Yarlung Zangbo Ophiolite is the forearc basement of the Asian active margin, its obduction onto India could not have preceded the initial closure of Neo-Tethys. Ophiolite obduction began when collision began, in the middle Paleocene.
Current deep neural network based approaches to computed tomography (CT) metal artifact reduction (MAR) are supervised methods that rely on synthesized metal artifacts for training. However, as ...synthesized data may not accurately simulate the underlying physical mechanisms of CT imaging, the supervised methods often generalize poorly to clinical applications. To address this problem, we propose, to the best of our knowledge, the first unsupervised learning approach to MAR. Specifically, we introduce a novel artifact disentanglement network that disentangles the metal artifacts from CT images in the latent space. It supports different forms of generations (artifact reduction, artifact transfer, and self-reconstruction, etc.) with specialized loss functions to obviate the need for supervision with synthesized data. Extensive experiments show that when applied to a synthesized dataset, our method addresses metal artifacts significantly better than the existing unsupervised models designed for natural image-to-image translation problems, and achieves comparable performance to existing supervised models for MAR. When applied to clinical datasets, our method demonstrates better generalization ability over the supervised models. The source code of this paper is publicly available at https:// github.com/liaohaofu/adn.
Emerging evidences have proved that long non-coding RNAs (lncRNAs) act as important molecular regulator in the tumor progression, including colorectal cancer (CRC). LncRNA SOX21-AS1 has been verified ...as oncogenic molecular in other cancers and tumorigenesis. In present study, our team investigates the clinical characteristic and molecular function in CRC carcinogenesis. Results showed that lncRNA SOX21-AS1 expression was significantly over-expressed in CRC tissue samples and cells. The aberrant over-expression of SOX21-AS1 indicated poor prognosis of CRC patients. In vitro and in vivo validation experiments, SOX21-AS1 silencing inhibited the proliferation, invasion, and decreased the tumor growth of CRC cells. Moreover, miR-145 was proved to be the target of SOX21-AS1, besides, myosin VI (MYO6) was found to be one of the targets of miR-145 using bioinformatics prediction programs and rescue confirmation experiments. In summary, our study reveals the tumorigenic effect of lncRNA SOX21-AS1 in CRC cells via targeting miR-145/MYO6, providing a novel insight for CRC carcinogenesis.
Materialomics integrates experiment, theory, and computation in a high‐throughput manner, and has changed the paradigm for the research and development of new functional materials. Recently, with the ...rapid development of high‐throughput characterization and machine‐learning technologies, the establishment of biomaterialomics that tackles complex physiological behaviors has become accessible. Breakthroughs in the clinical translation of nanoparticle‐based therapeutics and vaccines have been observed. Herein, recent advances in biomaterials, including polymers, lipid‐like materials, and peptides/proteins, discovered through high‐throughput screening or machine learning‐assisted methods, are summarized. The molecular design of structure‐diversified libraries; high‐throughput characterization, screening, and preparation; and, their applications in drug delivery and clinical translation are discussed in detail. Furthermore, the prospects and main challenges in future biomaterialomics and high‐throughput screening development are highlighted.
A systematic overview of the emerging field of intelligent biomaterialomics that integrates high‐throughput screening and data‐driven science to discover and design new biomaterials is presented. Methodologies for synthesizing biomaterials library, high‐throughput screening and characterization, and structure–activity relationships by data mining are summarized. Their biomedical applications, clinical translations, and challenges for future developments are highlighted.
To investigate the clinical and imaging characteristics of computed tomography (CT) in novel coronavirus pneumonia (NCP) caused by SARS-CoV-2.
A retrospective analysis was performed on the imaging ...findings of patients confirmed with COVID-19 pneumonia who had chest CT scanning and treatment after disease onset. The clinical and imaging data were analyzed.
Fifty patients were enrolled, including mild type in nine, common in 28, severe in 10 and critically severe in the rest three. Mild patients (29 years) were significantly (P<0.03) younger than either common (44.5 years) or severe (54.7) and critically severe (65.7 years) patients, and common patients were also significantly (P<0.03) younger than severe and critically severe patients. Mild patients had low to moderate fever (<39.1 °C), 49 (98%) patients had normal or slightly reduced leukocyte count, 14 (28%) had decreased counts of lymphocytes, and 26 (52%) patients had increased C-reactive protein. Nine mild patients were negative in CT imaging. For all the other types of NCP, the lesion was in the right upper lobe in 30 cases, right middle lobe in 22, right lower lobe in 39, left upper lobe in 33 and left lower lobe in 36. The lesion was primarily located in the peripheral area under the pleura with possible extension towards the pulmonary hilum. Symmetrical lesions were seen in 26 cases and asymmetrical in 15. The density of lesion was mostly uneven with ground glass opacity as the primary presentation accompanied by partial consolidation and fibrosis.
CT imaging presentations of NCP are mostly patchy ground glass opacities in the peripheral areas under the pleura with partial consolidation which will be absorbed with formation of fibrotic stripes if improved. CT scanning provides important bases for early diagnosis and treatment of NCP.
This paper investigates the impact mechanism by which an incentive-based fertility policy may reduce the labor income share. First, the specific paths through which this impact mechanism is realized ...are analyzed using the production function. It is found that an incentive-based fertility policy triggers high savings, which implies more, cheaper, and more readily available capital to be invested in production. A distribution system that earns income based on factor contributions results in more gains for capital than labor, i.e., a lower share of labor income and a wider income gap between labor and capital. Second, the impact mechanism includes three theoretical hypotheses. They are that an encouraging fertility policy is negatively related to labor income share; this relationship is valid provided that the study subject is in a closed economy; and that capital intensification is a mediator variable of fertility policy affecting labor income share. Finally, to further corroborate the impact mechanism in this paper, a Hansen threshold panel model is applied to verify that the effect of fertility policy on labor income share has a threshold effect. This indicates that the effect of the former on the latter changes significantly before and after the change in fertility policy, confirming the existence of an impact mechanism. The established literature has paid little attention to the impact of incentivised fertility policies on the labour income gap. Using capital intensification as the mediating variable, this paper demonstrates the existence of the former effect on the latter. In view of this, under the encouraged fertility policy, this paper proposes specific measures to enhance the labor income share in order to narrow the income gap between labor and capital.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This contribution highlights an eight-membered ring transition state for the aldol reaction of propanal on O-terminated ZrO2(111) and CeO2(111) surfaces. The relative heights of activation barriers ...for α-H abstraction and nucleophilic addition are controlled by surface acid-base pair strength. We report the first theoretical evidence of an alternative to the Zimmerman-Traxler model.
Abstract
Hub-filament systems (HFSs) are potential sites of protocluster and massive star formation, and play a key role in mass accumulation. We report JCMT POL-2 850
μ
m polarization observations ...toward the massive HFS SDC13. We detect an organized magnetic field near the hub center with a cloud-scale “U-shape” morphology following the western edge of the hub. Together with larger-scale APEX
13
CO and PLANCK polarization data, we find that SDC13 is located at the convergent point of three giant molecular clouds (GMCs) along a large-scale, partially spiral-like magnetic field. The smaller “U-shape” magnetic field is perpendicular to the large-scale magnetic field and the converging GMCs. We explain this as the result of a cloud–cloud collision. Within SDC13, we find that local gravity and velocity gradients point toward filament ridges and hub center. This suggests that gas can locally be pulled onto filaments and overall converges to the hub center. A virial analysis of the central hub shows that gravity dominates the magnetic and kinematic energy. Combining large- and small-scale analyses, we propose that SDC13 is initially formed from a collision of clouds moving along the large-scale magnetic field. In the post-shock regions, after the initial turbulent energy has dissipated, gravity takes over and starts to drive the gas accretion along the filaments toward the hub center.
Chemotherapy has been validated unavailable for treatment of renal cell carcinoma (RCC) in clinic due to its intrinsic drug resistance. Sensitization of chemo‐drug response plays a crucial role in ...RCC treatment and increase of patient survival. Herein, a recognition‐reaction‐aggregation (RRA) cascaded strategy is utilized to in situ construct peptide‐based superstructures on the renal cancer cell membrane, enabling specifically perturbing the permeability of cell membranes and enhancing chemo‐drug sensitivity in vitro and in vivo. First, P1‐DBCO can specifically recognize renal cancer cells by targeting carbonic anhydrase IX. Subsequently, P2‐N3 is introduced and efficiently reacts with P1‐DBCO to form a peptide P3, which exhibits enhanced hydrophobicity and simultaneously aggregates into a superstructure. Interestingly, the superstructure retains on the cell membrane and perturbs its integrity/permeability, allowing more doxorubicin (DOX) uptaken by renal cancer cells. Owing to this increased influx, the IC50 is significantly reduced by nearly 3.5‐fold compared with that treated with free DOX. Finally, RRA strategy significantly inhibits the tumor growth of xenografted mice with a 3.2‐fold enhanced inhibition rate compared with that treated with free DOX. In summary, this newly developed RRA strategy will open a new avenue for chemically engineering cell membranes with diverse biomedical applications.
The recognition–reaction–aggregation cascaded process is a promising strategy to in situ construct peptide‐based superstructures on the cancer cell membrane. The targeted peptide P1‐DBCO can specifically react with P2‐N3 to form a peptide P3, which exhibits enhanced hydrophobicity and simultaneously aggregates into a superstructure. The superstructure specifically perturbs the permeability of cell membranes and enhancing chemodrug sensitivity.
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