Defect formation is a common problem in selective laser melting （SLM）. This paper provides a review of defect formation mechanisms in SLM. It sum- marizes the recent research outcomes on defect ...findings and classification, analyzes formation mechanisms of the common defects, such as porosities, incomplete fusion holes, and cracks. The paper discusses the effect of the process parameters on defect formation and the impact of defect formation on the mechanical properties of a fabri- cated part. Based on the discussion, the paper proposes strategies for defect suppression and control in SLM.
Microbial induced carbonate precipitation (MICP) is a natural bio-mediated process, which has been explored for soil stabilization and heavy metals immobilization in soil and groundwater. Previous ...studies have shown that MICP is capable of immobilizing various heavy metals including lead (Pb). However, most studies focus merely on the immobilization of heavy metals with relatively low concentration. This study: (1) presents results of an investigation into the toxic effects of Pb on bacterial activity and immobilization efficiency within a wide range of Pb concentrations; and (2) identifies controlling biotic and abiotic factors of Pb immobilization by MICP. In the first series of tests, bacterial strains (Sporosarcina pasteurii) are inoculated into nutrient solutions containing 0–50 mM Pb(NO3)2 and incubated at 30 °C. Biochemical parameters are measured over time, which include pH, electrical conductivity, urease activity, and viable cell number. In the second series of tests, grown bacterial strains are mixed with urea, calcium salts and Pb(NO3)2 in solution. Viable cell number, produced ammonium concentration, aqueous Pb concentration of the mixed solution, and total precipitation mass are measured. The results show that the presence of Pb has marginal effect on bacterial growth and associated urease activity at Pb concentration < 30 mM. The calcium source and initial bacteria concentration are found to remarkably influence Pb immobilization efficiency in terms of Pb removal percentage. Supplementary geochemical simulation results indicate that the Pb immobilization mechanisms includes abiotic precipitation, biotic precipitation and bio-sorption.
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•Pb contaminants are immobilized by microbial induced carbonate precipitation.•Pb has toxic effects on bacterial activity and immobilization efficiency.•Abiotic and biotic precipitation and bio-sorption are immobilization mechanisms.
This study investigates diamond scratching at a high speed comparable to that in a grinding process on an ultraprecision grinder. Diamond tips are prepared for the study. The scratched silicon wafer ...is observed for changes in the surface layer with transmission electron microscopy. The observation discovers that an amorphous layer is formed on top of the pristine Si-I phase before the onset of chip formation. This discovery is different from the previous findings in which a damaged silicon layer is identified underneath the amorphous layer. Furthermore, no high pressure phase is found before the onset of chip formation.
This study explored the effect of liver resection on perioperative circulating tumor cells (CTCs) and found that the prognostic significance of surgery was associated with changes in CTC counts in ...patients with hepatocellular carcinoma (HCC).
One hundred thirty-nine patients with HCC were consecutively enrolled. The time-points for collecting blood were one day before operation and three days after operation. CTCs in the peripheral blood were detected by the CellSearch™ System.
Both CTC detection incidence and mean CTC counts showed greater increases postoperatively (54%, mean 1.54 cells) than preoperatively (43%, mean 1.13 cells). The postoperative CTC counts increased in 41.7% of patients, decreased in 25.2% of patients and did not change in 33.1% of patients. The increase in postoperative CTC counts was significantly associated with the macroscopic tumor thrombus status. Patients with increased postoperative CTC counts (from preoperative CTC < 2 to postoperative CTC ≥ 2) had significantly shorter disease-free survival (DFS) and overall survival (OS) than did patients with persistent CTC < 2. Patients with persistent CTC levels of ≥2 had the worst prognoses.
Surgical liver resection is associated with an increase in CTC counts, and increased postoperative CTC numbers are associated with a worse prognosis in patients with HCC.
Background
Spontaneous tumor rupture is a rare and life-threatening complication of hepatocellular carcinoma (HCC). The best treatment strategy remains unclear.
Methods
The clinical data of 137 ...patients with spontaneously ruptured HCC from 2010 to 2015 were reviewed retrospectively. We investigated the outcome and prognostic factors of various treatment strategies.
Results
Of the 137 patients, 53, 45, 3, and 36 patients underwent transcatheter arterial chemoembolization (TACE) alone, liver resection (LR) (LR alone or TACE + LR), surgical hemostasis, and conservative therapy. The patients undergoing LR had longest overall survival (OS). In the TACE alone group, independent factors affecting 30-day mortality were MELD score ≥ 12, AFP ≥ 1000 ng/ml, and largest tumor size ≥ 10 cm. AFP ≥ 1000 ng/ml, largest tumor size ≥ 10 cm, and no tumor capsule were significantly associated with poorer OS. In the LR group, largest tumor size ≥ 10 cm and no tumor capsule were the only independent prognostic factors for poorer OS and recurrence-free survival (RFS). Hypovolemic shock was an independent prognostic factor for poorer OS. The differences in OS between the TACE + LR group and LR alone group were not significant (
P
= 0.955). However, the RFS is significantly better in the LR alone group than those in the TACE + LR group (
P
= 0.031).
Conclusion
For resectable tumor, LR is the treatment of choice for patients with spontaneous ruptured HCC and preserved liver function. The delay in LR due to preoperative TACE may account for its worse RFS compared with LR alone. In patients with an unresectable tumor, TACE therapy alone improved survival over conservative therapy.
Small nucleolar RNAs (SnoRNAs) are a class of non-coding RNAs divided into two classes: C/D box snoRNAs and H/ACA box snoRNAs. The canonical function of C/D box and H/ACA box snoRNAs are 2'-
-ribose ...methylation and pseudouridylation of ribosomal RNAs (rRNAs), respectively. Emerging evidence has demonstrated that snoRNAs are involved in various physiological and pathological cellular processes. Mutations and aberrant expression of snoRNAs have been reported in cell transformation, tumorigenesis, and metastasis, indicating that snoRNAs may serve as biomarkers and/or therapeutic targets of cancer. Hence, further study of the functions and underlying mechanism of snoRNAs is valuable. In this review, we summarize the biogenesis and functions of snoRNAs, as well as the association of snoRNAs in different types of cancers and their potential roles in cancer diagnosis and therapy.
In this study, a novel approach of high speed scratching is carried out on silicon (Si) wafers at nanoscale depths of cut to investigate the fundamental mechanisms in wafering of solar cells. The ...scratching is conducted on a Si wafer of 150 mm diameter with an ultraprecision grinder at a speed of 8.4 to 15 m/s. Single-point diamonds of a tip radius of 174, 324, and 786 nm, respectively, are used in the study. The study finds that at the onset of chip formation, an amorphous layer is formed at the topmost of the residual scratch, followed by the pristine crystalline lattice beneath. This is different from the previous findings in low speed scratching and high speed grinding, in which there is an amorphous layer at the top and a damaged layer underneath. The final width and depth of the residual scratch at the onset of chip formation measured vary from 288 to 316 nm, and from 49 to 62 nm, respectively. High pressure phases are absent from the scratch at the onset of either chip or crack formation.
Background and Purpose
Colorectal cancer is the third most common cancer worldwide. HER2 and HER3 are two members of human epidermal receptor family of tyrosine kinase receptors (RTKs) and associated ...with poor survival in colorectal cancer. They have been observed as important therapeutic targets in various types of cancer. Corosolic acid, a natural pentacyclic triterpene, has been demonstrated to have a significant anti‐cancer activity. However, the target of corosolic acid has not yet been explored. This study aimed to reveal the direct targets of corosolic acid underlying its anti‐cancer activities.
Experimental Approach
The targets of corosolic acid were revealed by the phospho‐RTK array, bio‐layer interferometry, co‐immunoprecipitation, and proximity ligation assay. The inhibitory action of corosolic acid on HER2/HER3 heterodimerization and related downstream signalling were investigated in HCT116 and SW480 cells. In addition, the chemo‐preventive effects of corosolic acid were validated in both HCT116 xenograft model and AOM/DSS model.
Key Results
Our results demonstrated that corosolic acid could prevent NRG1‐induced HER2/HER3 heterodimerization and suppress the phosphorylation of both HER2 and HER3. Furthermore, HER2 and HER3 could regulate the downstream signalling pathways of RalA/RalBP1/CDK1 and PI3K/Akt/PKA, respectively, resulting in the changes in phosphorylation of Drp1 and mitochondrial dynamics. corosolic acid exhibited anti‐cancer activity in both HCT116 xenograft model and AOM/DSS model.
Conclusions and Implications
Collectively, our results demonstrated corosolic acid directly targeted HER2 and HER3 heterodimerization and inhibited mitochondrial fission via regulating RalA/RalBP1/CDK1 and PI3K/Akt/PKA pathways, revealing a novel mechanism underlying the beneficial effects of corosolic acid on colorectal cancer.
Background
The objective of this study was to evaluate the learning curve effect on the safety and feasibility of robot-assisted liver resection (RALR).
Methods
In 140 consecutive cases, all data ...about demographic, surgical procedure, postoperative course were collected prospectively and analyzed. Risk-adjusted cumulative sum model was used for determining the learning curve based on the need for conversion.
Results
Among all 140 patients, no patients suffered from any organ dysfunction postoperatively and the operative mortality was 0%. The CUSUM analysis showed that at the 30th consecutive patient, the open conversion rate reached to the average value, and it further improved thereafter. In the last 70 patients, only 3 patients (4.3%) required conversion and 7 patients (10%) needed blood transfusion. Only 1 patient (1.3%) out of 79 patients with HCC had a positive resection margin. Univariate analyses showed the following risk factors associated with significantly higher risks of conversion (
P
< 0.05): tumor number > 1, lesions in segments 1/4a/7/8, right posterior sectionectomy, and lesions which were beyond the indications of the Louisville statement. Multivariate logistic analysis revealed that both tumor number > 1 (OR: 2.10,
P
< 0.05) and right posterior sectionectomy (OR: 11.19,
P
< 0.01) were risk factors of conversion.
Conclusions
The robotic approach for hepatectomy is safe and feasible. A learning curve effect was demonstrated in this study after the 30th consecutive patient. The long-term oncological outcomes of robotic hepatectomy still need further investigation.
•CircFOXO3 is upregulated in GC cells and promotes GC malignancy in vitro and in vivo.•CircFOXO3 interacts with miR-143-3p and negatively regulates its expression.•MiR-143-3p interacts with USP44 and ...downregulates its expression in GC cells.•CircFOXO3 promotes the progression of GC by enhancing the output of miR-143-3p-USP44 axis.
Gastric carcinoma (GC) ranks fifth in terms of cancer morbidity and third in cancer-related death worldwide and imposes enormous health and economic burdens. The molecular mechanisms underlying GC formation and progression remain unclear. Our aim was to identify the involvement of circular RNA circFOXO3 in GC, and to determine the underlying mechanisms. In this study, we revealed a stimulatory role of circular RNA circFOXO3 in tumor growth in vivo. CircFOXO3 enhanced GC cell proliferation and migration in vitro and promoted tumor growth of GC cells in vivo. Bioinformatic analysis revealed that circFOXO3 might regulate USP44 expression by specifically binding to microRNA (miR)-143-3p. Existence of circFOXO3-miR-143-3p-USP44 axis in GC cells was confirmed by RNA-binding protein immunoprecipitation, luciferase reporter assay, and an RNA pull-down experiments. All the data indicate that circFOXO3 promotes GC cell proliferation and migration by upregulating USP44 expression via targeting of miR-143-3p.
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