Search

Slipping in cylindrical roller bearings is investigated at the simultaneous rotation of inner and outer rings. A 6-DOF dynamic model is developed to analyze roller, cage, and ring dynamics, assessing driven and resistance moments, cage rotating speed, and roller-raceway sliding velocities. The results show that if the inner and outer rings rotate inversely, the motion of rollers is relatively stable, which is beneficial for preventing the slipping in the bearing. However, if the inner and outer rings rotate in the same direction, the churning moment of rollers is high. Meanwhile, more rollers have a negative value of the sum of the churning moment and traction moment. This leads to an increase in the slipping of the bearing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adenosine triphosphate and malonic acid slowed down organic carbon degradation. • The addition of regulators reduced carbon loss rate, which were 5.73% and 4.06%. • Carbon-related microbe composition varied significantly across treatments. • Functional microorganisms related to carbon metabolism were identified. • To identify TCA cycle regulation as a key factor in improving carbon content. As a kind of livestock manure, chicken manure (CM) was rich in organic matter and microorganisms. However, a large amount of foul gas discharged by its random stacking not only threatened the environment, but also caused harm to human health. In view of the serious carbon loss and the unclear action mechanism of microbial community on carbon metabolism during CM composting, the effect of adding regulators on the sequestration of organic carbon was explored. Therefore, the purpose of this study was to explore the regulation mechanism of adding tricarboxylic acid cycle (TCA cycle) regulators on the core carbon metabolism pathway during CM composting. The results showed that the adenosine triphosphate (ATP) and malonic acid (MA) slowed down organic carbon degradation, resulting in lower carbon loss rate, which were 64.99% (CK), 62.35% (MA), and 61.26% (ATP) in each treatment. By comparing the abundance and structure of the carbon-related bacterial communities in different treatments, it was found that adding ATP and MA not only reduced the bacterial community abundance, but also tended to be similar in bacterial community composition. Moreover, the microbial specificity related to carbon metabolism pathway was enhanced, while the related gene expression and gene abundance were weakened. The regulation of TCA cycle metabolism pathway was confirmed to be the main way to improve organic carbon content. These findings revealed the positive effects of ATP and MA on carbon fixation from the perspective of gene metabolism. [ABSTRACT FROM AUTHOR]

The relevance of biopterin metabolism in resistance to immune checkpoint blockade (ICB) therapy remains unknown. We demonstrate that the deficiency of quinoid dihydropteridine reductase (QDPR), a critical enzyme regulating biopterin metabolism, causes metabolite dihydrobiopterin (BH2) accumulation and decreases the ratio of tetrahydrobiopterin (BH4) to BH2 in pancreatic ductal adenocarcinomas (PDACs). The reduced BH4/BH2 ratio leads to an increase in reactive oxygen species (ROS) generation and a decrease in the distribution of H3K27me3 at CXCL1 promoter. Consequently, myeloid-derived suppressor cells are recruited to tumor microenvironment via CXCR2 causing resistance to ICB therapy. We discovered that BH4 supplementation is capable to restore the BH4/BH2 ratio, enhance anti-tumor immunity, and overcome ICB resistance in QDPR-deficient PDACs. Tumors with lower QDPR expression show decreased responsiveness to ICB therapy. These findings offer a novel strategy for selecting patient and combining therapies to improve the effectiveness of ICB therapy in PDAC. [Display omitted] • QDPR deficiency drives immune suppression in pancreatic cancer • QDPR deficiency leads to ICB resistance via biopterin metabolic pathway • QDPR could serve as a predictive biomarker for ICB therapy in PDAC • BH4 supplementation sensitizes QDPR-deficient PDAC models to ICB The critical roles and mechanisms of biopterin metabolism in resistance to immune checkpoint blockade (ICB) therapy remain unknown. Liu et al. demonstrate the interplay between tumor-cell-hijacked biopterin metabolism and tumor immunity in PDAC and propose that QDPR deficiency causes ICB resistance in PDAC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three new isoprenoid pterocarpans, erystrictins A-C, were isolated from Erythrina stricta. • Alkaloid 22 was isolated from Erythrina genus for the first time. • Several compounds exhibited certain degrees of cytotoxic activity. A pair of diastereoisomeric pterocarpans, erystrictins A/B (1a/1b), possessing a highly oxidized 3-hydroxy-2-(1-hydroxy-1-methylethyl)- 2,3-dihydro furan substituent, and erystrictin C (2), along with seven known pterocarpans (3 - 9), eleven known flavonoids (10 - 20), and two known alkaloids (21 - 22) were isolated from Erythrina stricta. Their structures were established by extensive spectroscopic analyses, including HRESIMS, 1D and 2D NMR, and electronic circular dichroism (ECD) calculations. Using the MTS method, compounds 1 - 12 were tested for their cytotoxicity against the HL-60, SMMC-7721, A-549, MCF-7 and SW-480 human tumor cell lines, compounds 4, 10 and 12 showed moderated cytotoxicity. All the compounds, except for 10 and 12 were isolated from this plant for the first time. Compound 21 was isolated from Erythrina genus for the first time. [ABSTRACT FROM AUTHOR]

Humic acid (HA) from different organic solid waste (OSW) compost has been shown good adsorption properties for phenanthrene. However, the raw material of HA can affect its structure, resulting in differences in adsorption capacity. Therefore, this study focused on the adsorption characteristics of phenanthrene by HA from different OSW compost. In this work, chicken manure (CM), rice straw (RS) and lawn waste (LW) were selected as sources of composted HA. The adsorption mechanism of HA from different OSW compost were revealed through analytical techniques including three-dimensional fluorescence spectroscopy (EEM), two-dimensional correlation spectroscopy (2DCOS), and Fourier-transform infrared spectroscopy (FTIR). The results suggested that HA from LW compost had a better adsorption affinity for phenanthrene because of its more complex fluorescent component, where C1 as a simple component determined the adsorption process specifically. Furthermore, after HA from LW compost adsorbed phenanthrene, the increase in aromatic –COOH and –NH was the main reason for fluorescence quenching. These results indicated that HA from LW compost had better adsorption effect for phenanthrene. The results of this study were expected to provide a selection scheme for the control of phenanthrene pollution and environmental remediation. [Display omitted] • Fluorescence was excited by the adsorption of humic acid from chicken manure compost to phenanthrene. • Fluorescence was quenched by the adsorption of humic acid from rice straw and lawn waste compost to phenanthrene. • Aromatic –NH and –COOH contributed to fluorescence quenching of humic acid from lawn waste compost. • Humic acid from lawn waste compost had the better adsorption affinity for phenanthrene. [ABSTRACT FROM AUTHOR]

Osteosarcoma, the most prevalent primary malignancy of the bone, is often presented with high-grade subclinical metastatic disease that metastasizes at very early stages. Exosomes, as molecular information carriers, may play a potent role in the occurrence and development of tumors through oncogenic molecular reprogramming of tumor-associated macrophages (TAMs). In this study, we will investigate the effect of osteosarcoma-derived exosomes on the polarization of TAMs and decipher its underlying molecular mechanism. Osteosarcoma-derived exosomes from MG63 cells were isolated and characterized by transmission electron microscopy, and nano-particle size analysis. Double fluorescence staining was performed to confirm the macrophages phagocytosis of exosomes. Western blot, qRT-PCR, and transwell assays were conducted to assess the effect of exosomes on migration, invasion, and macrophage differentiation. The mouse model of osteosarcoma was established to evaluate the effects of exosomes on lung metastasis in vivo. MG63 exosomes were successfully isolated and verified to be phagocytized by macrophages through fluorescence confocal microscopy. The results revealed that osteosarcoma cells could induce M2 type differentiation of macrophages largely through Tim-3 mediated by exosomes, which in turn could promote the migration, invasion, epithelial-mesenchymal transition (EMT), and lung metastasis of osteosarcoma cells through the secretion of cytokines including IL-10, TGF-β, and VEGF. Our results demonstrated that osteosarcoma-derived exosomes induced M2 polarization of macrophages and promoted the invasion and metastasis of tumors through Tim-3; besides, the study also suggests a novel therapeutic target for future studies. [ABSTRACT FROM AUTHOR]

Clinical notes from electronic health records (EHR) are important to characterize the natural history, comorbidities, and complications of ANCA-associated vasculitis (AAV) because these details may not be captured by claims and structured data. However, labor-intensive chart review is often required to extract information from notes. We hypothesized that machine learning can automatically discover clinically-relevant themes across longitudinal notes to study AAV. This retrospective study included prevalent PR3- or MPO-ANCA+ AAV cases managed within the Mass General Brigham integrated health care system with providers' notes available between March 1, 1990 and August 23, 2018. We generated clinically-relevant topics mentioned in notes using latent Dirichlet allocation-based topic modeling and conducted trend analyses of those topics over the 2 years prior to and 5 years after the initiation of AAV-specific treatment. The study cohort included 660 patients with AAV. We generated 90 topics using 113,048 available notes. Topics were related to the AAV diagnosis, treatment, symptoms and manifestations (e.g., glomerulonephritis), and complications (e.g., end-stage renal disease, infection). AAV-related symptoms and psychiatric symptoms were mentioned months before treatment initiation. Topics related to pulmonary and renal diseases, diabetes, and infections were common during the disease course but followed distinct temporal patterns. Automated topic modeling can be used to discover clinically-relevant themes and temporal patterns related to the diagnosis, treatment, comorbidities, and complications of AAV from EHR notes. Future research might compare the temporal patterns in a non-AAV cohort and leverage clinical notes to identify possible AAV cases prospectively. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Transition-metal sulfides have been generally identified as one of the promising anode candidates for sodium ion batteries yet still suffer from serious capacity decay. Herein, we carry out a simple and effective hydrothermal method for preparation of vertically aligned SnS 2 nanosheets grown on carbon cloth as binder-free anode for sodium ion batteries. Specifically, the self-standing anode material displays excellent electrochemical properties including high specific capacity, outstanding rate capability, and long cycle stability. The large discharge capacity of 1039.9 mA h g−1 at 0.2 A g−1 is achieved. Even at much high current density of 2 A g−1, the reversible capacity can reach 673.4 mA h g−1 after 400 cycles. Meanwhile, this anode material can also withstand various current densities ranging from 0.1 to 2 A g−1 and exhibits good capacity recovery ability. Electrochemical kinetic analysis suggests that the mechanical flexibility between SnS 2 nanosheets and carbon cloth conductive substrate could well maintain the structural integrality, thus providing favorable transport kinetics for both electrons and sodium ions during repeated battery operation. The stable structure of well-aligned SnS 2 nanosheets vertically and orderly growing on carbon cloth leads to excellent sodium storage performance. Image 1 • Well-aligned SnS 2 nanosheets vertically and orderly growing on carbon cloth. • SnS 2 /CC anode delivers high reversible specific capacity and rate capability. • Stable 3D integral structure lead to excellent electrochemical property. [ABSTRACT FROM AUTHOR]