Molecular dynamics simulating the effects of Shockley-type stacking faults on the radiation displacement cascades in 4H-SiC.

Four-layer hexagonal silicon carbide (4H-SiC) is a promising material for high-temperature and radiation-rich environments due to its excellent thermal conductivity and radiation resistance. However, real 4H-SiC crystals often contain Shockley-type stacking faults (SSF), which can affect their radiation resistance. This study employed molecular dynamics (MD) simulation method to explore the effects of SSF on radiation displacement cascades in 4H-SiC. We conducted a comprehensive study of various SSF within the crystalline framework of 4H-SiC, and analyzed their stacking fault energy (SFE). We simulated the radiation displacement cascade in 4H-SiC with SSF and analyzed the effects of SSF on the distribution of radiation displacement defects. We simulated the radiation displacement cascade in 4H-SiC with SSF under different energies of primary knock-on atom (E PKA) and temperatures (T) conditions, and analyzed the variation pattern of the number of radiation displacement defects and clusters. The results indicated that SSF limits defect distribution position. SSF has an effect on the defects and clusters of 4H-SiC in the displacement cascade, and SSF can affect the maximum working temperature of 4H-SiC.

Ribosomal DNA copy number alteration in blood sample from gastric cancer patients.

BACKGROUND: Ribosomal DNA (rDNA) is the most abundant and important housekeeping gene in the cell. It usually acted as DNA damage sensor in DNA damage reaction. Gastric cancer (GC) as a tumor with high morbidity and mortality, it is hard to diagnosis in an early stage. METHODS: In this study, we collected and test the copy number of rDNA in blood sample of 42 GC patients and 56 healthy controls (HC) to explore the relationship between rDNA and GC. Besides, we make a correlation between the copy number of rDNA and ten biomarkers (CYFR21-1, CA15-3, CA72-4, NSE, CEA, CA125, ProGRP, AFP, SCC, CA19-9). RESULTS: The copy number of 18 S, 5.8 S, 28 S rDNA in GC is less than HC and 5 S is more than HC in their blood sample. And the expression of H-cox-1 and ND1 in GC is higher than HC in blood sample. it shows the expression of CA15-3 is related to ND1 and H-cox-1. CONCLUSION: We found for the first time the changes of rDNA and mtDNA expression in the blood of patients with gastric cancer. All these finding suggests rDNA may have potential in diagnosing GC.

Association between chili pepper consumption and risk of gastrointestinal-tract cancers: A meta-analysis.

Background: Stimulating food is emerging as an important modifiable factor in the development of gastrointestinal (GI) tract cancers, but the association between chili pepper consumption and the risk of GI cancers is unclear. We aimed to evaluate the direction and magnitude of the association between chili pepper consumption and the risk of GI cancers. Methods: A literature search was performed in PubMed, Embase, and Web of Science databases from inception to 22 December 2021. Observational studies reporting the association between chili pepper consumption and the risk of gastric cancer (GC), esophageal cancer (EC), and/or colorectal cancer (CRC) in adults were eligible for inclusion. Data extraction and quality assessment were conducted independently by two reviewers for the included literature. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Subgroup analyses were also performed based on the cancer type, study design, region of the study, study quality, and adjustments. Results: A total of 11,421 studies were screened, and 14 case-control studies were included involving 5009 GI cancers among 11,310 participants. The summary OR showed that high consumption of chili pepper was positively related to the risk of GI cancers (OR = 1.64; 95% CI: 1.00-2.70). A stronger positive relationship was observed between chili pepper consumption and EC risk (OR = 2.71; 95% CI: 1.54-4.75), but there was no statistically significant association between GC and CRC risk. In analyses stratified by geographical location, a positive association was found between chili pepper consumption and the risk of GI cancers in Asian studies (OR = 2.50; 95% CI: 1.23-5.08), African studies (OR = 1.62; 95% CI: 1.04-2.52), and North American studies (OR = 2.61; 95% CI: 1.34-5.08), but an inverse association was seen in South American studies (OR = 0.50; 95% CI: 0.29-0.87) and European studies (OR = 0.30; 95% CI: 0.15-0.61). Conclusion: This meta-analysis suggests that chili pepper is a risk factor for certain GI cancers (e.g., EC). Geographical regions influence the risk of GI cancers, especially in Asian, African, and North American populations, which require more attention during dietary guidance. Systematic review registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022320670].

Characteristics of gastric cancer gut microbiome according to tumor stage and age segmentation.

With the development of 16S rRNA technology, gut microbiome evaluation has been performed in many diseases, including gastrointestinal tumors. Among these cancers, gastric cancer (GC) exhibits high morbidity and mortality and has been extensively studied in its pathogenesis and diagnosis techniques. The current researches have proved that the gut microbiome may have the potential to distinguish GC patients from healthy patients. However, the change of the gut microbiome according to tumor node metastasis classification (TNM) has not been clarified. Besides, the characteristics of gut microbiome in GC patients and their ages of onset are also ambiguous. To address the above shortcomings, we investigated 226 fecal samples and divided them according to their tumor stage and onset age. The findings revealed that surgery and tumor stage can change the characteristic of GC patients' gut microbiota. In specific, the effect of surgery on early gastric cancer (EGC) was greater than that on advanced gastric cancer (AGC), and the comparison of postoperative microflora with healthy people indicated that EGC has more differential bacteria than AGC. Besides, we found that Collinsella, Blautia, Anaerostipes, Dorea, and Lachnospiraceae_ND3007_group expressed differently between EGC and AGC. More importantly, it is the first time revealed that the composition of gut microbiota in GC is different between different onset ages. KEY POINTS: •Gut microbiota of gastric cancer (GC) patients are either highly associated with TNM stage and surgery or not. It shows surgery has more significant changes in early gastric cancer (EGC) than advanced gastric cancer (AGC). •There existed specific gut microbiota between EGC and AGC which may have potential to distinguish the early or advanced GC. •Onset age of GC may influence the gut microbiota: the composition of gut microbiota of early-onset gastric cancer (EOGC) and late-onset gastric cancer (LOGC) is significantly different.

Characteristics of gut microbiota in patients with gastric cancer by surgery, chemotherapy and lymph node metastasis.

BACKGROUND: Gastric cancer (GC) is a malignant gastrointestinal tumor that can result in high mortality. Surgery and chemotherapy are often used for the effective treatment of GC. In addition, lymph node metastasis is a significant factor affecting the therapy of GC. Current researches have revealed that gut microbiota has the potential as biomarkers to distinguish healthy people and GC patients. However, the relationship between surgery, chemotherapy, and lymph node metastasis is still unclear. METHODS: In this study, 16S rRNA sequencing was used to investigate 157 GC fecal samples to identify the role of surgery, chemotherapy, and lymph node metastasis. Immunohistochemical analysis was used to value the expression of Ki67, HER2 in GC patient tissues. RESULTS: There exist some gut microbiotas which can distinguish surgery from non-surgery GC patients, including Enterococcus, Megasphaera, Corynebacterium, Roseburia, and Lachnospira. Differences between lymph node metastasis and chemotherapy in GC patients are not significant. Moreover, we found the abundance of Blautia, Ruminococcus, Oscillospira were related to the expression of Ki67 and the abundance of Prevotella, Lachnospira, Eubacterium, Desulfovibiro were correlated with the expression of HER2. CONCLUSIONS: The choice of treatment has a certain impact on the intestinal flora of patients with gastric cancer. Our research shows that surgery has a great effect on the intestinal flora of patients with gastric cancer. However, there were no significant differences in the characteristics of intestinal flora in patients with gastric cancer whether they received chemotherapy or whether they had lymph node metastasis. In addition, the association of gut microbiota with Ki67 and HER2 indicators is expected to provide the possibility of gut microbiota as a tumor prognostic marker.

Research progress on gut microbiota in patients with gastric cancer, esophageal cancer, and small intestine cancer.

The pathogenesis of gut microbiota in humans can be indicated due to the wide application of techniques, such as 16S rRNA sequencing. Presently, several studies have found a significant difference in fecal flora between normal individuals and patients with gastric cancer. Although clinical research on the feedback mechanism of gastric flora and gut microbiota is lacking, clarifying the relationship between gut microbiota and the characteristics of cancer is significant for the early diagnosis of gastric cancer. This study was conducted to review the results of several studies in the past 5 years and analyze the intestinal bacteria in patients with gastric cancer and compare them with those in patients with esophageal and small intestine cancers. It was found that the gut microbiota in patients with gastric cancer was similar to that in patients with esophageal cancer. However, making an analysis and comparing the gut microbiota in patients with small intestine and gastric cancers was impossible due to the low incidence of small intestinal cancer. Our review summarized the research progress on using the gut microbiota for early screening for gastric cancer, and the results of this study will provide a further direction in this field. KEY POINTS: • We reviewed several relative mechanisms of the gut microbiota related to gastric cancer. • The gut microbiota in gastric, esophageal, and small intestine cancers are significantly different in types and quantity, and we have provided some tips for further research. • A prospective review of sequencing methods and study results on the gut microbiota in gastric, esophageal, and small intestine cancers was described.

Bioactive Compounds, Antioxidants, and Health Benefits of Sweet Potato Leaves.

Sweet potato (Ipomoea batatas) is one of the most important food crops worldwide and its leaves provide a dietary source of nutrients and various bioactive compounds. These constituents of sweet potato leaves (SPL) vary among varieties and play important roles in treating and preventing various diseases. Recently, more attentions in health-promoting benefits have led to several in vitro and in vivo investigations, as well as the identification and quantification of bioactive compounds in SPL. Among them, many new compounds have been reported as the first identified compounds from SPL with their dominant bioactivities. This review summarizes the current knowledge of the bioactive compositions of SPL and their health benefits. Since SPL serve as a potential source of micronutrients and functional compounds, they can be further developed as a sustainable crop for food and medicinal industries.

Structural, biochemical, and physiological characterization of photosynthesis in leaf-derived cup-shaped galls on Litsea acuminata.

BACKGROUND: The source and sink relationships between insect-induced galls and host plant leaves are interesting. In this research, we collected cup-like galls induced by Bruggmanniella sp. (Diptera: Cecidomyiidae) on host leaves of Litsea acuminata and assessed them to investigate source-sink relationships between galls and host leaves. We characterized several of their photosynthetic characteristics including chlorophyll fluorescence (Fv/Fm), stomatal conductance, and photosynthetic capacity, biochemical components such as total soluble sugar, starches, free amino acids, and soluble proteins. The structural analyses were performed under confocal, light, and scanning electron microscopies. RESULTS: Compared with host leaves, galls exhibited slightly lower chlorophyll fluorescence; however, stomatal conductance and photosynthetic capacity were not detected at all. Galls accumulated higher total soluble sugars and free amino acids but less soluble proteins than host leaves. No stomata was observed on exterior or interior gall surfaces under light or scanning electron microscopy, but their inner surfaces were covered with fungal hyphae. Confocal imagery showed a gradient of chloroplasts distribution between gall outer and inner surfaces. CONCLUSIONS: Our results strongly suggest that leaf-derived cecidomyiid galls are a type of chlorophyll-deficient non-leaf green tissue and consists on a novel sink in L. acuminate.

Leaf-derived cecidomyiid galls are sinks in Machilus thunbergii (Lauraceae) leaves.

Three relevant hypotheses - nutrition, environment and the enemies hypothesis - often invoked to explore source and sink relationships between galls and their host plants are still under dispute. In this research, chlorophyll fluorescence, gas exchange capacity, stomatal conductance, total carbon and nitrogen, total soluble sugars and starches, and scanning and transmission electron microscopy of two types of galls were used to investigate source-sink relationships. Compared with host leaves, these galls demonstrated slightly lower chlorophyll fluorescence; however, gas exchange capacity and stomatal conductance were not detected at all. Scanning electron micrographs demonstrated that the abaxial epidermis of host leaves contain normal amounts of stomata, whereas no stomata were observed on the exterior and interior surfaces of both types of galls. In addition, gall inner surfaces were covered with many kinds of fungal hyphae. Gall total carbon (C) and nitrogen (N) levels were lower but the C/N ratio was higher in galls than host leaves. Both types of galls accumulated higher total soluble sugars and starches than host leaves. Transmission electron micrographs also revealed that both types of galls contain plastoglobuli and giant starch granules during gall development. Results strongly indicate that leaf-derived cecidomyiid galls are sinks in Machilus thunbergii leaves. However, it is perplexing how larvae cycle and balance CO(2) and O(2) in gall growth chambers without stomata.