45 research outputs found
ISG15 Modulates Development of the Erythroid Lineage
Activation of erythropoietin receptor allows erythroblasts to generate erythrocytes. In a search for genes that are up-regulated during this differentiation process, we have identified ISG15 as being induced during late erythroid differentiation. ISG15 belongs to the ubiquitin-like protein family and is covalently linked to target proteins by the enzymes of the ISGylation machinery. Using both in vivo and in vitro differentiating erythroblasts, we show that expression of ISG15 as well as the ISGylation process related enzymes Ube1L, UbcM8 and Herc6 are induced during erythroid differentiation. Loss of ISG15 in mice results in decreased number of BFU-E/CFU-E in bone marrow, concomitant with an increased number of these cells in the spleen of these animals. ISG15-/- bone marrow and spleen-derived erythroblasts show a less differentiated phenotype both in vivo and in vitro, and over-expression of ISG15 in erythroblasts is found to facilitate erythroid differentiation. Furthermore, we have shown that important players of erythroid development, such as STAT5, Globin, PLC Îł and ERK2 are ISGylated in erythroid cells. This establishes a new role for ISG15, besides its well-characterized anti-viral functions, during erythroid differentiation
The power of eWOM: A re-examination of online student evaluations of their professors
► College students’ course enrollment decisions are affected by RateMyProfessors.com. ► Students make their decisions based on valence of online reviews of professors. ► Students’ decisions are influenced by volume of online reviews of professors. ► Students’ decision-making process of course selections tends to be biased. ► Students’ attitudes toward their professors are affected by online reviews.
Over the past few years, a number of studies have examined the impact of the Rate My Professors (RMP) website (RateMyProfessors.com) on higher education. The focal area of examination is whether students’ evaluations of their professors on RMP are valid. The current study attempts to push the RMP discussions to a deeper level through two studies. Study 1 illustrates that students rely on the valence of review information on RMP to make their course selection decisions without considering its validity. Study 2 shows that students’ decision-making process tends to be biased as a result of review information available. The results of both studies suggest it is necessary for institutions to test new teaching evaluation models online
Quantitation of L-cystine in Food Supplements and Additives Using <sup>1</sup>H qNMR: Method Development and Application
Cystine-enriched food supplements are increasingly popular due to their beneficial health effects. However, the lack of industry standards and market regulations resulted in quality issues with cystine food products, including cases of food adulteration and fraud. This study established a reliable and practical method for determining cystine in food supplements and additives using quantitative NMR (qNMR). With the optimized testing solvent, acquisition time, and relaxation delay, the method exhibited higher sensitivity, precision, and reproducibility than the conventional titrimetric method. Additionally, it was more straightforward and more economical than HPLC and LC-MS. Furthermore, the current qNMR method was applied to investigate different food supplements and additives regarding cystine quantity. As a result, four of eight food supplement samples were found to be inaccurately labeled or even with fake labeling, with the relative actual amount of cystine ranging from 0.3% to 107.2%. In comparison, all three food additive samples exhibited satisfactory quality (the relative actual amount of cystine: 97.0–99.9%). Notably, there was no obvious correlation between the quantifiable properties (price and labeled cystine amount) of the tested food supplement samples and their relative actual amount of cystine. The newly developed qNMR-based approach and the subsequent findings might help standardization and regulation of the cystine supplement market
Technical Note—Perishable Inventory Systems: Convexity Results for Base-Stock Policies and Learning Algorithms Under Censored Demand
LncRNA PVT1 promotes the growth of HPV positive and negative cervical squamous cell carcinoma by inhibiting TGF-β1
Abstract Background Our study aimed to investigate the role of lncRNA PVT1 in cervical squamous cell carcinoma. Materials and methods A total of 156 patients with cervical squamous cell carcinoma were enrolled in this study and human papillomavirus (HPV) infection was detected by highly sensitive PCR techniques. Serum levels of PVT1 in patients infected with different HPVs and healthy controls was detected by qRT-PCR and compared. Serum levels of PVT1 were also compared among patients with different sizes of tumor. ROC curve analysis was performed to evaluate the diagnostic values of serum for cervical squamous cell carcinoma. Survival curves were plotted by Kaplan–Meier method and compared to evaluate the prognostic values of serum PVT1 for this disease. Effects of PVT1 siRNA silencing and overexpression on proliferation of cervical squamous cell carcinoma cells were explored by CCK-8 assay. Western blot was performed to detect the expression of TGF-β1 after PVT1 siRNA silencing and overexpression. Results No significant differences in serum levels of PVT1 were detected among patients infected with different HPVs and HPV-negative patients. However, serum levels of PVT1 were significantly higher in all patient groups than in healthy control group. Serum level of PVT1 increased with the increased sizes of primary tumor. Serum PVT1 accurately predicted the disease and its prognosis. PVT1 siRNA silencing inhibited the proliferation of cancer cells and reduced the expression of TGF-β1, while PVT1 overexpression played an opposite role. Conclusion LncRNA PVT1 promotes the growth HPV positive and negative cervical squamous cell carcinoma by inhibiting TGF-β1
Stress–Strain Model for Freezing Silty Clay under Frost Heave Based on Modified Takashi’s Equation
In analyzing frost heave, researchers often simplify the compressive modulus of freezing soil by considering it as a constant or only as a function of temperature. However, it is a critical parameter characterizing the stress–strain behavior of soil and a variable that is influenced by many other parameters. Hence, herein several one-dimensional freezing experiments are conducted on silty clay in an open system subjected to multistage freezing by considering the compressive modulus as a variable. First, freezing soil under multistage freezing is divided into several layers according to the frozen fringe theory. Then, the correlation between the freezing rate and temperature gradient within each freezing soil layer is investigated. Takashi’s equation for frost heave analysis is modified to extend its application conditions by replacing its freezing rate term with a temperature gradient term. A mechanical model for the stress–strain behavior of freezing soil under the action of frost heave is derived within the theoretical framework of nonlinear elasticity, in which a method for determining the compressive modulus of freezing soil with temperature gradient, overburden pressure, and cooling temperature variables is proposed. This study further enhances our understanding of the typical mechanical behavior of saturated freezing silty clay under frost heave action
Effects of Pyrolysis Temperature on the Release Characteristics of Polycyclic Aromatic Hydrocarbons during Pyrolysis of Corn Stover Pellet
The release characteristics of polycyclic aromatic hydrocarbons during the pyrolysis of biomass remain poorly understood. This study investigated the effects of pyrolysis temperature on the polycyclic aromatic hydrocarbon release characteristics by analyzing both the transient vapor products and the physicochemical properties of corresponding biochar from the pyrolysis of corn stover pellets. The results revealed that the transient volatile compounds mainly included phenols, ketones, acids, furans, aldehydes, substances containing benzene ring, polycyclic aromatic compounds, and gaseous products. A range of 2 to 4 ring polycyclic aromatic hydrocarbons were generated at 400 to 700 °C with the peak at 560 °C, and the sum of relative content of polycyclic aromatic hydrocarbons ranged from 0.23% to 40.36%. For the biochar, the carbonization stage (400 to 700 °C) of corn stover pellets was further divided into three evolutionary stages, including the preliminary carbonization stage (380 to 480 °C), amorphous carbon structure stage (480 to 600 °C), and the stage of dehydrogenation and growth of aromatic rings (600 to 700 °C).The relationship between polycyclic aromatic hydrocarbon release in volatile compounds and H/C ratio of the biochar could be described by a power function
Approximation Algorithms for Capacitated Perishable Inventory Systems with Positive Lead Times
Production of 1,2-Cyclohexanedicarboxylates from Diacetone Alcohol and Fumarates
1,2-Cyclohexanedicarboxylates, which are one of the most commonly used plasticizers in the poly(vinyl chloride) (PVC) industry, are generally prepared via the oxidation/esterification/hydrogenation of o-xylene (or naphthalene). Herein, we develop an alternative route toward cyclohexane-based plasticizers using diacetone alcohol and fumarates as the starting materials. The process includes a mild Raney Ni-catalyzed hydrogenation of diacetone alcohol, an one-step dehydration/Diels-Alder reaction of resulting 2-methyl-2,4-pentandiol and fumarates in a choline chloride (ChCl) based deep eutectic solvent (DES), and a further Pd/C-catalyzed hydrogenation. The toxicological tests indicate that the as-synthesized di(2-ethylhexyl) 3,5-dimethylcyclohexane-1,2-dicarboxylate can serve as a safe plasticizer for PVC materials