ROCK DRILLING WITH ABRASIVE SUSPENSION SWIRLING JET AND EFFECTS OF ADDITIVE POLYACRYLAMIDE

ABSTRACT Rock drilling experiments with an Abrasive Suspension Swirling Jet (ASSJ) have been carried out under submergence. Results show that the ASSJ can improve rock drilling with 2.2 times increase in drilling-hole diameter and with 4-5 times increase in rock removal volume when compared with non-swirling jet drilling of rock under identical conditions. And with higher PAM concentration added to the fluid, the ASSJ can significantly increase drilling depth, especially when drilling at longer standoff distance. It is also shown that the mechanism of ASSJ drilling at medium pressure on hard rocks is the overall breakage of rock grains and the binding material, in which jetting abrasive particles play dominant roles. The bottom hole shape of rock drilling with the ASSJ under submergence looks like "V". The higher rock drilling efficiency of the ASSJ results from the swirling of the jet. Organized and Sponsored by the WaterJet Technology Associatio

CTLA4+CD4+CXCR5−FOXP3+ T cells associate with unfavorable outcome in patients with chronic HBV infection

Abstract Background A major barrier to achieving a favorable outcome of chronic HBV infection is a dysregulated HBV-specific immune response resulting from immunosuppressive features of FOXP3+ T cells. A better definition of FOXP3+ T cells is essential for improving the prognosis of HBV infection. We aimed to investigate the role of CD4+CXCR5−FOXP3+ T cells with CTLA4 expression in patients with chronic HBV infection. Methods Treatment-naïve chronic HBV-infected patients, HBV-related hepatic failure, and a longitudinal cohort of chronic hepatitis B (CHB) patients with nucleos(t)ide analogue treatment were enrolled for analysis of CD4+CXCR5−FOXP3+ T cell responses by flow cytometry and single-cell RNA sequencing (scRNA-seq). Results ScRNA-seq revealed that circulating CD4+CXCR5−FOXP3+ T cells presented distinct inhibitory features compared to spleen tissue. Meanwhile, patients with treatment-naïve chronic HBV infection or with HBV-related hepatic failure showed an upregulation of immune-suppressive features (PD-1, CTLA4, GITR) on CD4+CXCR5−FOXP3+T cells; in vitro analysis found HBeAg and HBcAg stimulation induced elevated levels of inhibitory molecules. Notably, the frequency of CTLA4+CD4+CXCR5−FOXP3+ T cells was positively correlated with HBV DNA levels, and longitudinal analysis demonstrated a high frequency of this subset at 12 weeks of antiviral treatment predicted unfavorable outcome in CHB patients. Conclusions CTLA4+CD4+CXCR5−FOXP3+ T cells are related to unfavorable outcomes in HBV-infected patients; these data indicated that alleviating CTLA4+CD4+CXCR5−FOXP3+ T cells may improve the prognosis of HBV infection

Primers used in the study.

<p>Primers used in the study.</p

Assessment of sequence homology and immunologic cross-reactivity between tree shrew (<i>Tupaia belangeri</i>) and human IL-21

<div><p>Many studies have indicated that the expression of interleukin-21 (IL-21) is associated with the pathogenesis of certain liver diseases. However, in alternative animal models of liver diseases, it remains unknown whether the tree shrew could be utilized to analyze the relationship between IL-21 and liver diseases. Here, the phylogenetic tree, sequence alignment and protein structure model of tree shrew and human IL-21 were analyzed using bioinformatics software. A pEGFP-N3/tsIL-21 eukaryotic expression vector of tree shrew IL-21 (tsIL-21) was constructed, and IL-21 expression by the vector-transfected Huh7 cells was evaluated using the newly established quantitative real-time PCR and immunologic protocols for assessing human IL-21. The cytokine profiles were also evaluated in tree shrew spleen lymphocytes induced by recombinant human IL-21 or concanavalin A. It was found that the coding sequence (CDS) of tsIL-21 amplified from spleen lymphocytes belonged to the predicted sequence. The tsIL-21 was closely clustered with primate IL-21 rather than rodent IL-21, and it had an alignment of 83.33% with the human IL-21 nucleotide sequence and 69.93% with the amino acid sequence. The profiles of secondary structure, hydrophobicity and surface charge of tsIL-21 were also similar with those of human IL-21. The tsIL-21 expressed by the vector-transfected Huh7 cells could be identified by their different sources of antibodies against human IL-21, which were all dose-dependent. Recombinant human IL-21 could induce the change of the cytokine profiles of tree shrew spleen lymphocytes, which showed a higher expression of IL-10 and IFN-γ rather than IL-2, IL-4, IL-17, TNF-a and IL-21 during the five-day stimulation. These results indicate that tsIL-21 has a high degree of homology, structural similarity and immunological cross-reactivity with human IL-21 and also confirm the accuracy of this predicted tsIL-21CDS. The protocols utilized in this study will lead to the experimental feasibility of further IL-21-related studies in vivo.</p></div

The IL-21 expression in tree shrew samples.

<p>(A) Concentrations of IL-21 in supernatant from tree shrew spleen lymphocytes induced with ConA by ELISA. (B) Quantification of IL-21 mRNA expression in tree shrew spleen lymphocytes induced by ConA. *represents a significant difference compared to stimulation with ConA and the unstimulated negative control (<i>P</i><0.05). (C) The IL-21 expression of tree shrews spleen lymphocytes and human peripheral blood mononuclear cells were detected by flow cytometry staining.</p

Homology analysis of the IL-21 gene.

<p>(A) Phylogenetic tree of the IL-21 gene based on the amino acid sequences among eighteen species. Alignment of tree shrew and human IL-21 coding sequences (B) and amino acid sequences (C).</p

Effects of recombinant human IL-21 on the cytokine profiles of tree shrew spleen lymphocytes.

<p>*represents a statistically significant difference between two groups (<i>P</i><0.05).</p