scholarly journals Influence of Effective Pressure on Percolation Rate of Coal

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fukun Xiao ◽  
Wenhai Xu ◽  
Renhe Li ◽  
Fengrui Zhang ◽  
Lei Xu ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Reference Value ◽  
Research Direction ◽  
Gas Pressure ◽  
Theoretical Equation ◽  
Effective Pressure ◽  
Effective Prevention ◽  
Finite Element Software ◽  
Percolation Rate

To study the role of the effective pressure on the percolation rate of coal, the effect of gas pressure, gas adsorption, and temperature on coal is taken into consideration comprehensively. Starting from the research direction of effective pressure and porosity, the coal body percolation rate and effective pressure equations considering the influence of temperature and gas pressure are established. The experiments on the percolation characteristics of raw coal are implemented under different effective pressure by using the independently developed thermos-solid-gas linking triaxial servosystem. The theoretical equation of the effective pressure and percolation rate of coal is calculated with the finite element software COMSOL, and the results obtained from the theoretical equation agree well with the experimental results. The results show that the percolation rate of coal gradually decreases with the growth of the effective pressure when the gas pressure and temperature are kept unchanged. Therefore, the results of the research are of certain reference value for the effective prevention of gas disaster.

scholarly journals Advances in the role of miRNAs in the occurrence and development of osteosarcoma

Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1003-1011
Author(s):  
Guanyu Zhang ◽  
Yiran Li ◽  
Jiasheng Xu ◽  
Zhenfang Xiong
Keyword(s):  
Target Gene ◽  
Early Stage ◽  
Research Direction ◽  
Research Progress ◽  
Skeletal System ◽  
Translation Process ◽  
Non Coding Rnas ◽  
New Research ◽  
Post Transcriptional Regulation

AbstractOsteosarcoma (OS) is the most common primary malignant tumor of the skeletal system in the clinic. It mainly occurs in adolescent patients and the pathogenesis of the disease is very complicated. The distant metastasis may occur in the early stage, and the prognosis is poor. MicroRNAs (miRNAs) are non-coding RNAs of about 18–25 nt in length that are involved in post-transcriptional regulation of genes. miRNAs can regulate target gene expression by promoting the degradation of target mRNAs or inhibiting the translation process, thereby the proliferation of OS cells can be inhibited and the apoptosis can be promoted; in this way, miRNAs can affect the metabolism of OS cells and can also participate in the occurrence, invasion, metastasis, and recurrence of OS. Some miRNAs have already been found to be closely related to the prognosis of patients with OS. Unlike other reviews, this review summarizes the miRNA molecules closely related to the development, diagnosis, prognosis, and treatment of OS in recent years. The expression and influence of miRNA molecule on OS were discussed in detail, and the related research progress was summarized to provide a new research direction for early diagnosis and treatment of OS.

scholarly journals Protein farnesylation is upregulated in Alzheimer’s human brains and neuron-specific suppression of farnesyltransferase mitigates pathogenic processes in Alzheimer’s model mice

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Angela Jeong ◽  
Shaowu Cheng ◽  
Rui Zhong ◽  
David A. Bennett ◽  
Martin O. Bergö ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Small Gtpases ◽  
Specific Role ◽  
Postmortem Brain ◽  
Effective Prevention ◽  
Postmortem Brain Tissue ◽  
Mtorc1 Signaling ◽  
Behavioral Assessments ◽  
Human Brains

AbstractThe pathogenic mechanisms underlying the development of Alzheimer’s disease (AD) remain elusive and to date there are no effective prevention or treatment for AD. Farnesyltransferase (FT) catalyzes a key posttranslational modification process called farnesylation, in which the isoprenoid farnesyl pyrophosphate is attached to target proteins, facilitating their membrane localization and their interactions with downstream effectors. Farnesylated proteins, including the Ras superfamily of small GTPases, are involved in regulating diverse physiological and pathological processes. Emerging evidence suggests that isoprenoids and farnesylated proteins may play an important role in the pathogenesis of AD. However, the dynamics of FT and protein farnesylation in human brains and the specific role of neuronal FT in the pathogenic progression of AD are not known. Here, using postmortem brain tissue from individuals with no cognitive impairment (NCI), mild cognitive impairment (MCI), or Alzheimer’s dementia, we found that the levels of FT and membrane-associated H-Ras, an exclusively farnesylated protein, and its downstream effector ERK were markedly increased in AD and MCI compared with NCI. To elucidate the specific role of neuronal FT in AD pathogenesis, we generated the transgenic AD model APP/PS1 mice with forebrain neuron-specific FT knockout, followed by a battery of behavioral assessments, biochemical assays, and unbiased transcriptomic analysis. Our results showed that the neuronal FT deletion mitigates memory impairment and amyloid neuropathology in APP/PS1 mice through suppressing amyloid generation and reversing the pathogenic hyperactivation of mTORC1 signaling. These findings suggest that aberrant upregulation of protein farnesylation is an early driving force in the pathogenic cascade of AD and that targeting FT or its downstream signaling pathways presents a viable therapeutic strategy against AD.

Finite element analysis of hydrogen effects on superelastic NiTi shape memory alloys: Orthodontic application

2018 ◽  
Vol 29 (16) ◽  
pp. 3188-3198 ◽  
Author(s):  
Wissem Elkhal Letaief ◽  
Aroua Fathallah ◽  
Tarek Hassine ◽  
Fehmi Gamaoun
Keyword(s):  
Finite Element ◽  
Coupled Model ◽  
Element Model ◽  
Orthodontic Wires ◽  
Niti Wire ◽  
Element Analysis ◽  
Finite Element Software ◽  
Orthodontic Wire ◽  
Niti Shape Memory Alloys

Thanks to its greater flexibility and biocompatibility with human tissue, superelastic NiTi alloys have taken an important part in the market of orthodontic wires. However, wire fractures and superelasticity losses are notified after a few months from being fixed in the teeth. This behavior is due to the hydrogen presence in the oral cavity, which brittles the NiTi arch wire. In this article, a diffusion-mechanical coupled model is presented while considering the hydrogen influences on the NiTi superelasticity. The model is integrated in ABAQUS finite element software via a UMAT subroutine. Additionally, a finite element model of a deflected orthodontic NiTi wire within three teeth brackets is simulated in the presence of hydrogen. The numerical results demonstrate that the force applied to the tooth drops with respect to the increase in the hydrogen amount. This behavior is attributed to the expansion of the NiTi structure after absorbing hydrogen. In addition, it is shown that hydrogen induces a loss of superelasticity. Hence, it attenuates the role of the orthodontic wire on the correction tooth malposition.

Assessment of surface energetic heterogeneity of synthetic Na- saponites. The role of layer charge

Clay Minerals ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 39-57 ◽  
Author(s):  
L. J. Michot ◽  
F. Villiéras
Keyword(s):  
Aspect Ratio ◽  
Gas Adsorption ◽  
High Energy ◽  
Layer Charge ◽  
Adsorption Mechanisms ◽  
Energetic Heterogeneity ◽  
Complex Adsorption ◽  
Adsorption Energy Distribution ◽  
Synthetic Saponite

AbstractHigh-resolution gas adsorption techniques were used to analyse the evolution of the aspect ratio and adsorption energy distribution on synthetic saponite samples with increasing layer charge. Using Ar as a gaseous probe, the aspect ratio of the saponite particles can be determined easily by decomposing the derivative adsorption isotherms and taking into account high-energy sites which can be assigned to talc-like ditrigonal cavities. Changes in the shape of the elementary particles are observed for layer charges above 1.30, i.e. when all the ditrigonal cavities contain at least one Al atom substituting for Si. When N2 is used as a probe, high-energy sites that could be wrongly interpreted as micropores on the basis of classical t-plot treatments are observed whatever the layer charge. Using the information obtained from both Ar and N2, schemes for describing adsorption can be proposed for all layer charges and suggest complex adsorption mechanisms for charged clay minerals.

scholarly journals Has-miR-875-5p Inhibits Tumorigenesis by Targeting USF2 via TGF-β Signaling Pathway in Gastric Cancer

2021 ◽  
Author(s):  
Shenshuo Gao ◽  
Zhikai Zhang ◽  
Xubin Wang ◽  
Yan Ma ◽  
Chensheng Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Signaling Pathway ◽  
Research Direction ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Gastric Cancer Cells ◽  
New Research

Abstract Background: Gastric cancer (GC) is one of the most common malignancies, and more and more evdiences show that the pathogenesis is regulated by various miRNAs.In this study, we investigated the role of miR-875 in GC. Methods:The expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA RT-PCR. The effect of miR-875-5p on GC proliferation was determined by CCK-8 proliferation assay and EDU assay. Migration and invasion were examined by transwell migration and invasion assay and wound healing assay. The interaction between miR-875-5p and its target gene USF2 was verified by a dual luciferase reporter assay. The effects of miR-875-5p in vivo were studied in xenograft nude mice models.Related proteins were detected by Western blot.Results:The results showed that miR-875-5p inhibited the proliferation, migration and invasion of gastric cancer cells in vitro, and inhibited tumorigenesis in vivo. USF2 proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracts the effects of miR-875-5p inhibitors.Overexpression of miR-875-5p can inhibit proliferation, migration, and invasion through the TGF-β signaling pathway by down-regulation of USF2 in GC, providing a new research direction for the diagnosis and targeted therapy of GC.Conclusions: MiR-875-5pcan inhibited the progression of GC by directly targeting USF2 and negatively regulating TGF-β signaling pathway.In the future, miR-875-5p is expected to be used as a potential therapeutic target for GC therapy.

scholarly journals Role of anion ordering and effective pressure in the field-induced spin-density-wave phase of (TMTSF) 2 X

2016 ◽  
Vol 115 (3) ◽  
pp. 37002
Author(s):  
T. Minamidate ◽  
N. Matsunaga ◽  
K. Nomura ◽  
T. Sasaki
Keyword(s):  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Effective Pressure ◽  
Wave Phase

scholarly journals Induction of Changes in Internal Gas Pressure of Bulky Plant Organs by Temperature Gradients

1990 ◽  
Vol 115 (2) ◽  
pp. 308-312 ◽  
Author(s):  
Kenneth A. Corey ◽  
Zhi-Yi Tan
Keyword(s):  
Bath Temperature ◽  
Ideal Gas ◽  
Gas Pressure ◽  
Temperature Gradients ◽  
Maximum Pressure ◽  
Plant Organs ◽  
Ideal Gas Law ◽  
Increasing Temperature ◽  
Pressure Changes

Water manometers were connected to fruits of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and then fruits were submerged in water baths providing initial temperature gradients between fruit and water of 0 to 19C. Apple (Malus domestics Borkh.) fruits, carrot (Daucus carota L.) roots, witloof chicory (Cichorium intybus L.) roots, rhubarb Rheum rhabarbarum L.) petioles, and pokeweed (Phytolacca americana L.) stems were subjected to water bath temperature gradients of 5C. Internal partial vacuums developed in all organs within minutes of imposing the gradients. The maximum partial vacuums in tomato and pepper fruits increased with increasing temperature gradients. Uptake of water accompanied changes in internal pressure reaching maxima of 17% (w/w) and 2% (w/w) of pepper and tomato fruits, respectively, after 22 hours. Maximum pressure changes achieved in bulky organs deviated from those predicted by the ideal gas law, possibly due to concomitant changes in gas pressure upon replacement of intercellular spaces with water and dissolution of CO2. Partial vacuums also developed in pepper fruits, rhubarb petioles, and pokeweed stems following exposure to air 15C cooler than initial organ temperatures. Results point to the role of temperature gradients in the transport of liquids and gases in plant organs.

The role of vitamin D dificiency in the development of pathology in women of perimenopausal age

2018 ◽  
pp. 76-79
Author(s):  
Kh.V. Kozak ◽  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Neurological Diseases ◽  
Research Direction ◽  
Literary Sources ◽  
Autoimmune Conditions ◽  
Calcium Phosphorus ◽  
The Relationship

The article presents an analysis of literary sources about contemporary views on the role of vitamin D deficiency in the health problems of women of the perimenopausal period. According to research data of recent years, vitamin D plays a role not only in the control of calcium-phosphorus metabolism, but also plays a role in the pathogenesis of cardiovascular and neurological diseases, insulin resistance and diabetes, in the development of cancer and autoimmune conditions, especially in women of perimenopausal age. It is important to continue the study of the relationship between vitamin D deficiency and menopausal and menopausal disorders. Currently, the existing principles and effectiveness of the correction of lack of vitamin D in improving the quality of life of women of perimenopausal age are ambiguously assessed, which determines the relevance of this research direction. Key words: perimenopausal period, insufficiency/deficiency of vitamin D.

African-American Youth: Drug Trafficking and the Justice System

PEDIATRICS ◽  
1994 ◽  
Vol 93 (6) ◽  
pp. 1078-1084
Author(s):  
Susan Leviton ◽  
Marc A. Schindler ◽  
Renee S. Orleans
Keyword(s):  
Juvenile Justice ◽  
Drug Trafficking ◽  
Justice System ◽  
Juvenile Justice System ◽  
Social Issues ◽  
African American Youth ◽  
Treatment Interventions ◽  
Effective Prevention ◽  
Analytic Review

Objective. To examine the role of the legal system in adolescent drug trafficking. Methods. Descriptive and analytic review of the literature and relevant legislation. Findings. Utilization of young adolescents by drug "kingpins" in drug trafficking is a new practice that is highly advantageous to the employer for several legal and economic reasons. From the perspective of the drug kingpins, juveniles are particularly useful in drug trafficking because they work for lower wages. Further, even if the youth are arrested, the juvenile justice system enables their rapid return for continued service in the drug trade. From the perspective of the youth, drug trafficking offers one of the few economic opportunities available to them. Further, the numbers suggest a tremendous racial disparity in the juvenile justice system. Conclusions. The mutual advantages to both employer and employee of using youths in drug trafficking increases the likelihood that this new practice will continue to flourish and with increasingly young children. Effective prevention and treatment interventions will need to be multifaceted, addressing the economic, educational, and social issues that have permitted the rapid emergence of adolescent drug trafficking. Finally, further investigation of the apparent racial disparities is necessary.

Canakinumab for secondary prevention of coronary artery disease

2021 ◽  
Author(s):  
Luis Ortega-Paz ◽  
Davide Capodanno ◽  
Dominick J Angiolillo
Keyword(s):  
Secondary Prevention ◽  
Outcome Study ◽  
Prevention Strategies ◽  
Effective Prevention ◽  
New Era ◽  
Development Status ◽  
The Cantos ◽  
Artery Disease ◽  
Effective Prevention Strategies

Cardiovascular disease manifestations (CVD) are the world's leading cause of death, and their impact on morbidity requires effective prevention strategies of recurrent adverse events. For decades, inflammation has been proposed as a key promoter for atherosclerosis and its complications. However, studies on the use of drugs to target the excess inflammation in CVD are limited. In 2017, the Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS) trial confirmed the key role of inflammation on atherosclerotic disease. Canakinumab is a monoclonal antibody that blocks an inflammatory pathway mediated by IL-1β. The results of the CANTOS trial opened a new era of investigating new therapeutics targeting inflammation for CVD secondary prevention. This review presents the canakinumab's pharmacology, current clinical development status and regulatory perspectives.

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