Raman study of silicon telluride nanoplates and their degradation

Silicon telluride (Si₂Te₃) has emerged as one of the many contenders for 2D materials ideal for the fabrication of atomically thin devices. Despite the progress which has been made in the electric and optical properties of silicon telluride, much work is still needed to better understand this material. We report here on the Raman study of Si₂Te₃degradation under both annealing andin situheating with a laser. Both processes caused pristine Si₂Te₃to degrade into tellurium and silicon oxide in air in the absence of a protective coating. A previously unreported Raman peak at ∼140 cm^-1was observed from the degraded samples and is found to be associated with pure tellurium. This peak was previously unresolved with the peak at 144 cm^-1for pristine Si₂Te₃in the literature and has been erroneously assigned as a signature Raman peak of pure Si₂Te₃, which has caused incorrect interpretations of experimental data. Our study has led to a fundamental understanding of the Raman peaks in Si₂Te₃, and helps resolve the inconsistent issues in the literature. This study is not only important for fundamental understanding but also vital for material characterization and applications.

Machine Learning in Differentiating Gliomas from Primary CNS Lymphomas: A Systematic Review, Reporting Quality, and Risk of Bias Assessment

BACKGROUND

Differentiating gliomas and primary CNS lymphoma represents a diagnostic challenge with important therapeutic ramifications. Biopsy is the preferred method of diagnosis, while MR imaging in conjunction with machine learning has shown promising results in differentiating these tumors.

PURPOSE

Our aim was to evaluate the quality of reporting and risk of bias, assess data bases with which the machine learning classification algorithms were developed, the algorithms themselves, and their performance.

DATA SOURCES

Ovid EMBASE, Ovid MEDLINE, Cochrane Central Register of Controlled Trials, and the Web of Science Core Collection were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

STUDY SELECTION

From 11,727 studies, 23 peer-reviewed studies used machine learning to differentiate primary CNS lymphoma from gliomas in 2276 patients.

DATA ANALYSIS

Characteristics of data sets and machine learning algorithms were extracted. A meta-analysis on a subset of studies was performed. Reporting quality and risk of bias were assessed using the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) and Prediction Model Study Risk Of Bias Assessment Tool.

DATA SYNTHESIS

The highest area under the receiver operating characteristic curve (0.961) and accuracy (91.2%) in external validation were achieved by logistic regression and support vector machines models using conventional radiomic features. Meta-analysis of machine learning classifiers using these features yielded a mean area under the receiver operating characteristic curve of 0.944 (95% CI, 0.898-0.99). The median TRIPOD score was 51.7%. The risk of bias was high for 16 studies.

LIMITATIONS

Exclusion of abstracts decreased the sensitivity in evaluating all published studies. Meta-analysis had high heterogeneity.

CONCLUSIONS

Machine learning-based methods of differentiating primary CNS lymphoma from gliomas have shown great potential, but most studies lack large, balanced data sets and external validation. Assessment of the studies identified multiple deficiencies in reporting quality and risk of bias. These factors reduce the generalizability and reproducibility of the findings.

[Contrastive analysis about the postoperative clinical characteristics of elderly patients with colorectal cancer in different age groups]

Objective: To explore the postoperative clinical characteristics of elderly patients with colorectal cancer at different ages. Methods: Retrospective analysis was performed on the clinical data of 720 elderly patients with Colorectal Cancer in Beijing Hospitals from January 2012 to December 2019. There were 411 males and 309 females with a median age of 74 years. We divided the patients into young-old, old-old, oldest-old colorectal cancer patient groups and used chi-square comparative analysis of different groups of patients with clinical disease characteristics. Results: The oldest-old colorectal cancer patients tended to have normal body mass index (BMI), and the site of the disease shifted to the right. The incidence of concomitant diseases such as heart disease and hypertension increases gradually with age, and the incidence of diabetes is highest in old-old colorectal cancer patients. The proportion of open surgery was higher in the oldest-old group, but the operation time was shorter than the other two groups. In addition, the incidence of postoperative complications in elderly patients with colorectal cancer gradually increases with age, especially cardiac complications and other complications such as pneumonia, deep venous thrombosis of lower limbs, urinary retention, urinary tract infection, renal failure, cerebral hemorrhage, cerebral infarction, and so on. Conclusions: The BMI of the oldest-old patients tended to be normal, and the site of the disease shifted to the right. The incidence of heart disease, hypertension, and other concomitant diseases and postoperative complications in elderly patients with colorectal cancer gradually increase with age. Thus, the choice of treatment should be more individualized for elderly patients with colorectal cancer, and more attention should be paid to perioperative management.

Criticality analysis for safety-critical software in nuclear power plant distributed control system

Software criticality analysis examines the degree of contribution that each individual failure mode of a software component has on the reliability of software. Higher safety integrity levels are assigned to software modules whose failures cause an unacceptable impact on the operation of the system, and these levels require the implementation of more rigorous software quality assurance measures as defined in IEEE Std 1012 and in the customer’s system requirements specification. In this paper, a novel software criticality analysis method is proposed, the results of which can be used to guide the development of newly developed software and the procurement of Commercial-Off-The-Shelf (COTS) software. The software structure is first analyzed and the software is divided into modules according to their functions. Then the criticality levels of software components are preliminarily classified by means of a safety criticality preliminary analysis tree, followed by their verification through the software hazard and operability analysis (HAZOP). Finally, the target Safety Integrity Level (SIL) of each software module is determined based on its criticality level and the overall safety objective (i. e., SIL) of the system it resides in. As an example, this proposed method is applied to a nuclear power plant safety-critical system to demonstrate the detail application process and to verify the feasibility of the method. Compared with the existing software criticality analysis methods, this method has better operability and verifiability, and can be utilized as a technical guidance for the software criticality analysis of nuclear power plant digital control systems.

Relationship between onset of eclampsia and AGTR1 gene polymorphisms

OBJECTIVE

We aimed to study the correlations of angiotensin II receptor type 1 (AGTR1) gene polymorphisms with the occurrence and development of eclampsia.

PATIENTS AND METHODS

A total of 200 pregnant women with eclampsia admitted to our hospital from January 1, 2017 to September 30, 2019 were collected as observation group and 200 normal pregnant women during the same period were recruited in the control group. Genome sequencing was performed to detect the AGTR1 gene polymorphisms in the two groups. Expression level of AGTR1 in both groups was detected. The influences of AGTR1 on clinical data of pregnant women with eclampsia were analyzed.

RESULTS

There were no significant differences in age (p=0.545), height (p=0.738), weight (p=0.695) and hypertension (p=0.372) between observation group and control group. However, significant differences were found in the distributions of alleles at AGTR1 rs1799870 (p=0.002) and AGTR1 rs52936049 (p=0.047) between groups. The frequencies of T allele at rs1799870 and rs52936044 in observation group were higher than those in the control group. In addition, the distributions of AGTR1 gene genotypes at rs1799870 (p=0.012), rs144520513 (p=0.008) and rs529360494 (p p =0.036) in observation group differed from those in control group. Observation group had higher frequencies of TT genotype at rs1799870, GG genotype at rs144520513 and TG genotype at rs529360494 than those in control group. Besides, the frequency of CGG haplotype (p=0.008) of AGTR1 gene in observation group was notably lower than that in the control group, while the frequency of TGT haplotype (p=0.012) of AGTR1 gene in the former was remarkably higher than that in the latter. Moreover, the linkage disequilibrium between rs529360494 and rs144520513 of AGTR1 gene was relatively high (D'=0.623). AGTR1 gene polymorphism rs529360494 showed an evident relationship with the expression of AGTR1 gene, and the expression of AGTR1 in pregnant women with eclampsia who carried TG genotype was markedly reduced (p<0.05). Furthermore, AGTR1 gene polymorphism rs1799870 was associated with prothrombin time (PT) in pregnant women with eclampsia (p=0.046), and PT in those carrying genotype TC was shorter. Rs144520513 was related to the levels of triglyceride (TG) (p<0.001) and low-density lipoprotein (LDL) (p<0.001) in pregnant women with eclampsia, and TG and LDL levels were significantly lower.

CONCLUSIONS

AGTR1 gene polymorphisms are closely associated with the onset and progression of eclampsia.

Thermally-assisted milling and hydrogenolysis for synthesizing ultrafine MgH2with destabilized thermodynamics

A novel process has been developed to synthesize MgH₂nanoparticles by combining ball milling and thermal hydrogenolysis of di-n-butylmagnesium (C₄H₉)₂Mg, denoted as MgBu₂. With the aid of mechanical impact, the hydrogenolysis temperature of MgBu₂in heptane and cyclohexane solution was considerably lowered down to 100 °C, and the MgH₂nanoparticles with an average particle size ofca.8.9 nm were obtained without scaffolds. The nano-size effect of the MgH₂nanoparticles causes a notable decrease in the onset dehydrogenation temperature of 225 °C and enthalpy of 69.78 kJ mol^-1 · H₂. This thermally-assisted milling and hydrogenolysis process may also be extended for synthesizing other nanomaterials.

[Chaihu Guizhi decoction produces antidepressant-like effects via sirt1-p53 signaling pathway]

OBJECTIVE

To investigate the mechanism of the antidepressant-like effects of Chaihu Guizhi decoction (CGD).

OBJECTIVE

Chaihu Guizhi decoction at the daily dose of 17 g/kg and solvent vehicle were administered by gavage in 12 and 14 male C57BL/6J mice for 7 consecutive days, respectively. Forced swimming test (FST), elevated plus maze (EPM) test, open field test (OFT) and novelty-suppressed feeding test (NSF) were performed to assess the depression- and anxiety-like behaviors and motor ability of the mice. We further used chronic social defeat stress (CSDS) and social interaction test to evaluate the antidepressant-like effects of CGD in comparison with the solvent vehicle. Western blotting and RT-qPCR were performed to detect the expressions of sirt1, p53, acetylated p53, and the neuron plasticity-related genes including synapsin I (Syn1), Rab4B, SNAP25 and tubulin beta4b in the hippocampus of the mice.

OBJECTIVE

In FST, the immobility time of CGDtreated mice was decreased significantly (P < 0.05); no significant differences were found in the performances in EPM, NSF and OFT tests between the two groups. In social interaction test, the mouse models of CSDS treated with CGD showed significantly increased time in the interaction zone (P < 0.05). Compared with those in the vehicle group, the CGD-treated mouse models exhibited significantly increased protein level of SIRT1 and decreased p53 acetylation (P < 0.05) with up-regulated synapsin I mRNA expression in the hippocampus (P < 0.05); no significant difference were found in Rab (P=0.813), SNAP (P=0.820), or Tubb mRNA expressions (P=0.864) between the two groups.

OBJECTIVE

CGD produces antidepressant-like effects in mice possibly through the sirt1-p53 signaling pathway and synaptic plasticity.

Pulsed Microfluid Force-Based On-Chip Modular Fabrication for Liver Lobule-Like 3D Cellular Models

In vitro three-dimensional (3D) cellular models with native tissue-like architectures and functions have potential as alternatives to human tissues in regenerative medicine and drug discovery. However, it is difficult to replicate liver constructs that mimic in vivo microenvironments using current approaches in tissue engineering because of the vessel-embedded 3D structure and complex cell distribution of the liver. This paper reports a pulsed microflow-based on-chip 3D assembly method to construct 3D liver lobule-like models that replicate the spatial structure and functions of the liver lobule. The heterogeneous cell-laden assembly units with hierarchical cell distribution are fabricated through multistep photopatterning of different cell-laden hydrogels. Through fluid force interaction by pulsed microflow, the hierarchical assembly units are driven to a stack, layer by layer, and thus spatially assemble into 3D cellular models in the closed liquid chamber of the assembly chip. The 3D models with liver lobule-like hexagonal morphology and radial cell distribution allow the dynamic perfusion culture to maintain high cell viability and functional expression during long-term culture in vitro. These results demonstrate that the fabricated 3D liver lobule-like models are promising for drug testing and the study of individual diagnoses and treatments.

High expression of LINC0163 promotes progression of papillary thyroid cancer by regulating epithelial-mesenchymal transition MITF

OBJECTIVE

The purpose of this study was to detect the expression of long non-coding ribonucleic acid 00163 (LINC00163) in human papillary thyroid cancer (PTC), and to observe the influence of downregulated LINC00163 on the proliferative and metastatic capacities of human PTC cells.

PATIENTS AND METHODS

Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) assay was applied to measure the expression level of LINC00163 in PTC tissues and para-carcinoma tissues, as well as that in normal human thyroid cells (Nthy-ori3-1) and PTC cells. After the expression of LINC00163 in PTC cells was interfered, qRT-PCR assay was performed to determine the interference efficiency, and colony formation and Cell Counting Kit-8 (CCK-8) assays were conducted to study the impacts of small interfering (si)-LINC00163 on the proliferative capacity of PTC cells. Moreover, wound healing and transwell assays were adopted to investigate the changes in the migratory and invasive abilities of PTC cells after the interference in the expression of LINC00163 in PTC cells. Finally, the changes in expressions of molecular markers in downstream signaling pathways after interference in LINC00163 expression were examined via Western blotting assay.

RESULTS

In 51 cases of PTC tissues and corresponding para-carcinoma tissues, 41 cases exhibited an up-regulated expression of LINC00163, and qRT-PCR results indicated that PTC cells also had an up-regulated expression of LINC00163 compared with normal human thyroid cells. After the expression of LINC00163 in PTC cells was interfered, the results of colony formation and CCK-8 assays manifested that the proliferative capacity of the cells declined. It was also shown in wound-healing and transwell assay results that the migratory and invasive abilities of the cells were weakened. In addition, the results of Western blotting assay revealed expression changes in the molecular markers of epithelial-mesenchymal transition (EMT).

CONCLUSIONS

The expression of LINC00163 in NSCLC tissues and cells is upregulated, and highly expressed LINC00163 can promote PTC cell proliferation and metastasis by regulating the EMT.

A triple-classification radiomics model for the differentiation of pleomorphic adenoma, Warthin tumour, and malignant salivary gland tumours on the basis of diffusion-weighted imaging

AIM

To develop and validate a triple-classification radiomics model for the preoperative differentiation of pleomorphic adenoma (PA), Warthin tumour (WT), and malignant salivary gland tumour (MSGT) based on diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Data from 217 patients with histopathologically confirmed salivary gland tumours (100 PAs, 68 WTs, and 49 MSGTs) from January 2015 to March 2019 were analysed retrospectively and divided into a training set (n=173), and a validation set (n=44). A total of 396 radiomic features were extracted from the DWI of all patients. Analysis of variance (ANOVA) and least absolute shrinkage and selection operator (LASSO) regression were used to select radiomic features, which were then constructed using three classification models, namely, logistic regression method (LR), support vector machine (SVM), and K-nearest neighbor (KNN). The diagnostic performance of the radiomics model was quantified by the receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) of the training and validation data sets.

RESULTS

The 20 most valuable features were investigated based on the LASSO regression. LR and SVM methods exhibited better diagnostic ability than KNN for multiclass classification. LR and SVM had the best performance and yielded the AUC values of 0.857 and 0.824, respectively, in the training data set and the AUC values of 0.932 and 0.912, respectively, in the validation data set of MSGT diagnosis.

CONCLUSION

DWI-based triple-classification radiomics model has predictive value in distinguishing PA, WT, and MSGT, which can be used for preoperative auxiliary diagnosis in clinical practice.

3,5-Dimethoxy-4-hydroxy myricanol attenuated oxidative stress-induced toxicity on cardiomyoblast cells

Myocardial ischemia is the main reason for ischemic heart diseases. Antioxidant treatment is considered as a possible approach to prevent myocardial ischemia injury, because oxidative stress is a key factor triggering it. This study was to investigate the protective effects of 3,5-dimethoxy-4-hydroxy myricanol (DHM) against oxidative stress-induced cytotoxicity on H9c2 cells and further explore its mechanisms. The oxidative stress and inflammatory response markers were detected by H2DCFDA fluorescent measurement, enzyme-linked immunosorbent assay (ELISA), real-time PCR and Western blot. Results showed DHM exerted inhibitory effects against H9c2 cell damage. Furthermore, DHM decreased oxidative stress in H9c2 cells through up-regulating protein expression of heme oxygenase-1 (HO-1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Moreover, DHM inhibited inflammatory responses through down-regulating the protein expression of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB). DHM exerted protective activities against oxidative stress-induced cell damage, at least through decreasing oxidative stress and inhibiting inflammatory responses, indicating that DHM have the potential to be developed as therapeutic agents for the treatment of myocardial ischemia.