Persistent white matter changes in recovered COVID-19 patients at the 1-year follow-up.

There is growing evidence that severe acute respiratory syndrome coronavirus 2 can affect the CNS. However, data on white matter and cognitive sequelae at the 1-year follow-up are lacking. Therefore, we explored these characteristics in this study. We investigated 22 recovered coronavirus disease 2019 (COVID-19) patients and 21 matched healthy controls. Diffusion tensor imaging, diffusion kurtosis imaging and neurite orientation dispersion and density imaging were performed to identify white matter changes, and the subscales of the Wechsler Intelligence scale were used to assess cognitive function. Correlations between diffusion metrics, cognitive function and other clinical characteristics were then examined. We also conducted subgroup analysis based on patient admission to the intensive care unit. The corona radiata, corpus callosum and superior longitudinal fasciculus had a lower volume fraction of intracellular water in the recovered COVID-19 group than in the healthy control group. Patients who had been admitted to the intensive care unit had lower fractional anisotropy in the body of the corpus callosum than those who had not. Compared with the healthy controls, the recovered COVID-19 patients demonstrated no significant decline in cognitive function. White matter tended to present with fewer abnormalities for shorter hospital stays and longer follow-up times. Lower axonal density was detected in clinically recovered COVID-19 patients after 1 year. Patients who had been admitted to the intensive care unit had slightly more white matter abnormalities. No significant decline in cognitive function was found in recovered COVID-19 patients. The duration of hospital stay may be a predictor for white matter changes at the 1-year follow-up.

Calycosin stimulates the osteogenic differentiation of rat calvarial osteoblasts by activating the IGF1R/PI3K/Akt signaling pathway.

Calycosin has been reported to have a strong osteogenic activity and a positive correlation with anti-osteoporosis effects. However, its precise mechanism of action remains unclear. Since insulin-like growth factor 1 receptor (IGF1R) signaling and phosphatidylinositol 3-kinase/Akt (PI3K/Akt) signaling have been shown to play a pivotal role in regulating osteogenesis, we hypothesized that the osteogenic activity of calycosin is mediated by these signaling pathways. Rat calvarial osteoblasts (ROBs) were cultured in osteogenic medium containing calycosin with or without GSK1904529A (GSK) or LY294002 (LY) (inhibitors of IGF1R and PI3K, respectively). The effects on cell proliferation, alkaline phosphatase (ALP) activity, calcified nodules, mRNA or protein expression of osteogenic genes [alkaline phosphatase (Alpl), collagen type I (Col1a1), runt-related transcription factor 2 (Runx2), Osterix, and bone morphogenetic protein 2 (Bmp2)], and phosphorylation of IGF1R and Akt were examined. The present results showed that calycosin enhanced cell proliferation, ALP activity and Alizarin Red-S staining in a dose-dependent manner in the range of 10-8 -10-6 M, while an inhibitory effect was observed at 10-5 M. Treatment at the optimal concentration (10-6 M, a physiologically achievable concentration) increased mRNA levels of osteogenic genes and phosphorylation of IGF1R and Akt. Furthermore, treatment with GSK or LY partly reversed the effects of calycosin on ROBs, as indicated by the decreases in calycosin-induced ALP activity, calcified nodules and osteogenic gene expression. These results suggest that the osteogenic effect of calycosin partly involves the IGF1R/PI3K/Akt signaling pathway.

[Complex enzyme combined with ultrasound extraction technology, physicochemical properties and antioxidant activity of Hedysarum polysaccharides].

In this study, complex enzymes combined with ultrasonic extraction technology（MC） were used, to select optimal extraction combinations by single factor and orthogonal test, with Hedysarum polysaccharides yield and content as the comprehensive indexes. The components, physicochemical properties and antioxidant activity of Hedysarum polysaccharides from complex enzyme combined with ultrasonic extraction（HPS-MC）and the Hedysarum polysaccharides from hot water extraction（HPS-R）were analyzed. The results showed that：complex enzymes had significant effect on the yield and content of Hedysarum polysaccharides, and the ultrasonic power could significantly improve the content of Hedysarum polysaccharides. The optimum technological parameters were as follows: complex enzyme ratio 1:1, ultrasonic power 105 W, ultrasonic time 60 min, and enzymatic hydrolysis pH 5, achieving （14.01±0.64）% and （92.45±1.47）% respectively for the yield and content of Polysaccharides. As compared with HPS-R, the molecular weight, absolute viscosity and protein content of HPS-MC were decreased, while the content of uronic acid was increased. In the antioxidant system, the concentration of polysaccharide was within the range of 1-7 g·L⁻¹; the antioxidant activity of HPS-MC was higher than that of HPS-R, and HPS-MC (80%) with the lowest molecular weight showed a significant dose effect relationship with the increase of the experimental concentration. In conclusion, MC is a simple, convenient, economical and environmentally friendly extraction technology, and the Hedysarum polysaccharides extracted by this method have obvious antioxidant activity.

Angelica sinensis polysaccharide suppresses the Wnt/ß-catenin-mediated malignant biological behaviors of breast cancer cells via the miR-3187-3p/PCDH10 axis.

Breast cancer (BC) is one of the most common malignant tumors in women. Angelica sinensis polysaccharide (ASP) is one of the main components extracted from the traditional Chinese medicine Angelica sinensis. Research has shown that ASP affects the progression of various cancers by regulating miRNA expression. This study aimed to explore the specific molecular mechanism by which ASP regulates BC progression through miR-3187-3p. After the overexpression or knockdown of miR-3187-3p and PDCH10 in BC cells, the proliferation, migration, invasion, and phenotype of BC cells were evaluated after ASP treatment. Bioinformatics software was used to predict the target genes of miR-3187-3p, and luciferase gene reporter experiments reconfirmed the targeted binding relationship. Subcutaneous tumor formation experiments were conducted in nude mice after the injection of BC cells. Western blot and Ki-67 immunostaining were performed on the tumor tissues. The results indicate that ASP can significantly inhibit the proliferation, migration, and invasion of BC cells. ASP can inhibit the expression of miR-3187-3p in BC cells and upregulate the expression of PDCH10 by inhibiting miR-3187-3p. A regulatory relationship exists between miR-3187-3p and PDCH10. ASP can inhibit the expression of ß-catenin and phosphorylated glycogen synthase kinase-3ß (p-GSK-3ß) proteins through miR-3187-3p/PDCH10 and prevent the occurrence of malignant biological behavior in BC. Overall, this study revealed the potential mechanism by which ASP inhibits the BC process. ASP mediates the Wnt/ß-catenin signaling pathway by affecting the miR-3187-3p/PDCH10 molecular axis, thereby inhibiting the proliferation, migration, invasion, and other malignant biological behaviors of BC cells.

Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study.

Background and purpose: Long COVID with regard to the neurological system deserves more attention, as a surge of treated patients are being discharged from the hospital. As the dynamic changes in white matter after two years remain unknown, this characteristic was the focus of this study. Methods: We investigated 17 recovered COVID-19 patients at two years after discharge. Diffusion tensor imaging, neurite orientation dispersion and density imaging were performed to identify white matter integrity and changes from one to two years after discharge. Data for 13 revisited healthy controls were collected as a reference. Subscales of the Wechsler Intelligence scale were used to assess cognitive function. Repeated-measures ANOVA was used to detect longitudinal changes in 17 recovered COVID-19 patients and 13 healthy controls after one-year follow-up. Correlations between diffusion metrics, cognitive function, and other clinical characteristics (i.e., inflammatory factors) were also analyzed. Results: Longitudinal analysis showed the recovery trends of large-scale brain regions, with small-scale brain region deterioration from one year to two years after SARS-CoV-2 infection. However, persistent white matter abnormalities were noted at two years after discharge. Longitudinal changes of cognitive function showed no group difference. But cross-sectional cognitive difference between recovered COVID-19 patients and revisited HCs was detected. Inflammation levels in the acute stage correlated positively with white matter abnormalities and negatively with cognitive function. Moreover, the more abnormal the white matter was at two years, the greater was the cognitive deficit present. Conclusion: Recovered COVID-19 patients showed longitudinal recovery trends of white matter. But also had persistent white matter abnormalities at two years after discharge. Inflammation levels in the acute stage may be considered predictors of cognition and white matter integrity, and the white matter microstructure acts as a biomarker of cognitive function in recovered COVID-19 patients. These findings provide an objective basis for early clinical intervention.

Molecular Dynamics Simulation of Fe-Based Metal Powder Oxidation during Laser Powder Bed Fusion.

Because the laser powder bed fusion process is generally completed in a confined space and in a very short time, it is difficult to study material oxidation during this process using traditional methods. To address this knowledge gap, in this work, we used molecular dynamics (MDs) based on a reaction force field (ReaxFF) to clarify the atomic-level interaction mechanism between metal atoms and oxygen molecules during laser powder bed fusion. The ReaxFF potential energy model has variable charges that can dynamically handle charge changes between atoms and the breaking and formation of chemical bonds that occur during oxidation reactions. We investigated the effects of laser power, scanning speed, region position, and oxygen concentration on powder oxidation. The results show that the laser power and scanning speed affected the oxidation degree by changing the energy input density, and the oxidation degree increased with the energy input density. Different forms of oxidation occurred near the melt channel due to the existence of a temperature gradient, and the degree of oxidation increased with the temperature. Atoms in the metal powder model underwent selective oxidation, which was related to the potential energy of their atomic position. A larger potential energy made it easier for iron atoms to overcome the energy barrier during the initial stage of oxidation, making them easier to oxidize.

Case Report: Pirfenidone in the Treatment of Post-COVID-19 Pulmonary Fibrosis.

Background: Pulmonary fibrosis is one of the sequelae of the COVID-19, which seriously affects the quality of life of survivors. Currently, there are no optimal evidence based guidelines targeting this population. Case Presentation: We report a 66-year-old female patient without underlying comorbidities admitted to Changsha Public Health Center because of COVID-19. During hospitalization, she developed co-bacterial infection and acute respiratory distress syndrome, and received broad-spectrum antibacterial therapy, invasive mechanical ventilation and extracorporeal membrane oxygenation. After the acute phase, she developed post-COVID-19 pulmonary fibrosis subsequently treated with pirfenidone. Over 96 weeks after pirfenidone treatment, her modified Medical Research Council Dyspnea level improved to 2 from 4 at discharge. Her 6 minutes walk test distance, total lung capacity, and diffusion capacity for carbon monoxide all increased. Chest CT performed on 2 years after illness onset showed regressing fibrosis. The Hospital Anxiety and Depression Scale, Athens Insomnia Scale, and 36-Item Short Form Health Survey questionnaire all improved. Conclusion: Post-COVID-19 pulmonary fibrosis is a challenging consequence of COVID-19, and our case suggests that pirfenidone may be an effective treatment option.

Case Report: Community-Acquired Legionella gormanii Pneumonia in an Immunocompetent Patient Detected by Metagenomic Next-Generation Sequencing.

BACKGROUND: Legionella spp. has been well-recognized as an important cause of community-acquired pneumonia. Current community-acquired pneumonia guidelines recommended covering the treatment of Legionella because of the high mortality associated with inadequate antibiotic treatments. However, the symptom of Legionella pneumonia is non-specific, and routine diagnostic tests exhibit low sensitivity for Legionella spp., especially for non-Legionella pneumophila serogroup 1 strains. CASE PRESENTATION: We report a 53-year-old man without underlying diseases admitted to respiratory intensive care unit because of severe community-acquired pneumonia and respiratory failure. Although, the results of routine culture of bronchoalveolar lavage fluid and the Legionella urinary antigen test were all negative, metagenomic next-generation sequencing (mNGS) identified a great amount of DNA and RNA sequences of Legionella gormanii in bronchoalveolar lavage fluid while negative in blood sample. The presence of Legionella gormanii in bronchoalveolar lavage fluid was further confirmed by polymerase-chain-reaction and Sanger sequencing. CONCLUSION: Legionella gormanii has rarely been reported in patients with community-acquired pneumonia mainly due to lack of diagnostic test for non-Legionella pneumophila serogroup 1 strains. This is the first report of Legionella gormanii pneumonia in an immunocompetent patient detected by mNGS, which indicates that mNGS is a high-resolution and sensitive assay for the diagnosis and surveillance of Legionella infection.

Survivors of COVID-19 exhibit altered amplitudes of low frequency fluctuation in the brain: a resting-state functional magnetic resonance imaging study at 1-year follow-up.

Although some short-term follow-up studies have found that individuals recovering from coronavirus disease 2019 (COVID-19) exhibit anxiety, depression, and altered brain microstructure, their long-term physical problems, neuropsychiatric sequelae, and changes in brain function remain unknown. This observational cohort study collected 1-year follow-up data from 22 patients who had been hospitalized with COVID-19 (8 males and 11 females, aged 54.2 ± 8.7 years). Fatigue and myalgia were persistent symptoms at the 1-year follow-up. The resting state functional magnetic resonance imaging revealed that compared with 29 healthy controls (7 males and 18 females, aged 50.5 ± 11.6 years), COVID-19 survivors had greatly increased amplitude of low-frequency fluctuation (ALFF) values in the left precentral gyrus, middle frontal gyrus, inferior frontal gyrus of operculum, inferior frontal gyrus of triangle, insula, hippocampus, parahippocampal gyrus, fusiform gyrus, postcentral gyrus, inferior parietal angular gyrus, supramarginal gyrus, angular gyrus, thalamus, middle temporal gyrus, inferior temporal gyrus, caudate, and putamen. ALFF values in the left caudate of the COVID-19 survivors were positively correlated with their Athens Insomnia Scale scores, and those in the left precentral gyrus were positively correlated with neutrophil count during hospitalization. The long-term follow-up results suggest that the ALFF in brain regions related to mood and sleep regulation were altered in COVID-19 survivors. This can help us understand the neurobiological mechanisms of COVID-19-related neuropsychiatric sequelae. This study was approved by the Ethics Committee of the Second Xiangya Hospital of Central South University (approval No. 2020S004) on March 19, 2020.

Performance Testing and Rapid Solidification Behavior of Stainless Steel Powders Prepared by Gas Atomization.

Gas atomization is a widely used method to produce the raw powder materials for additive manufacturing (AM) usage. After the metal alloy is melted to fusion, gas atomization involves two relatively independent processes: liquid breakup and droplet solidification. In this paper, the solidification behavior of powder during solidification is analyzed by testing the powder's properties and observing microstructure of a martensitic stainless steel (FeCrNiBSiNb). The powder prepared by gas atomization has high sphericity and smooth surface, and the yield of qualified fine powder is 35%. The powder has typical rapid solidification structure. Collision between powders not only promotes nucleation, but also produces more satellite powder. The segregation of elements in powder is smaller as the result of high cooling rate which can reaches 4.2 × 105 K/s in average. Overall, the powder prepared by gas atomization is found to have good comprehensive properties, desired microstructure, and accurate chemical component, and it is suitable for various additive manufacturing techniques.

Correction: Formononetin in Radix Hedysari extract-mediated green synthesis of gold nanoparticles for colorimetric detection of ferrous ions in tap water.

[This corrects the article DOI: 10.1039/D0RA05660J.].

The amelioration of ulcerative colitis induced by Dinitrobenzenesulfonic acid with Radix Hedysari.

Ulcerative colitis (UC) is a chronic inflammatory disease with an unknown precise etiology. This study proves that Radix Hedysari (RH) ameliorates UC. Four RH extracts were used to ameliorate UC induced by 2,4-Dinitrobenzenesulfonic acid by 7 days intervention in agreement to preliminary studies. Compared to treatment with RH extracts, the RH ethanol extract (EE) was found to be more effective in ameliorating UC. With EE, the DAI were significantly decreased. Macroscopic and histopathological assessments suggest that the colon mucosa was repaired, the organizational structure of the colon had been rebuilt. The levels of MPO, TNF-α, IL-1ß, and MDA were significantly decreased (p < .01), the levels of T-SOD and CAT were significantly increased (p < .01). Moreover, the compounds in EE were analyzed by HPLC. The results show that EE can ameliorate UC, and its anti-inflammatory capability probably plays an important role. RH can act as a functional food and ameliorate UC. PRACTICAL APPLICATIONS: In this work, the ameliorative effect of RH on UC was evaluated from multiple angles. There are two practical applications of this work. On the one hand, a new approach to ameliorating UC is provided by this work. In addition, UC patients have a new option for improving their symptoms. On the other hand, this work also provides information on how best to process RH for therapeutic use. In addition, we can utilize some compounds of RH that were once considered useless and reduce the waste of natural resources.

Formononetin in Radix Hedysari extract-mediated green synthesis of gold nanoparticles for colorimetric detection of ferrous ions in tap water.

This study linked natural plant materials and nanomaterials; reporting an environmentally friendly, non-toxic and efficient method for the green synthesis of gold nanoparticles (AuNPs) using an ethyl acetate extract of Radix Hedysari (EAR). The components of the extract were identified using HPLC and it was found that formononetin accounted for more than 90% of the total contents. We predicted that formononetin in EAR plays a crucial role in green synthesis. Thus, formononetin was used as a standard reductant to synthesize AuNPs, and the result confirmed our prediction. The synthetic mechanism was also discussed in detail in the article. Moreover, EAR-AuNPs realized the sensitive and selective colorimetric detection of ferrous ions (Fe2+) among other metal ions, and were applied to spiked tap water with a low detection limit of 1.5 µM in a wide range from 10 µM to 500 µM. EAR-AuNPs were green synthesized using Radix Hedysari extract for the first time and were successfully applied in real sample detection.

Protective effect of polysaccharides from Radix Hedysari on gastric ulcers induced by acetic acid in rats.

The dry root of Hedysarum polybotrys Hand.-Mazz., commonly known as "Hong Qi", has a variety of health benefits. The present study was undertaken to explore the anti-gastric ulcer potential effect of Hedysarum polysaccharides (HPS; HPS-50, HPS-80), the principal active fraction of Radix Hedysari (RH). The anti-gastric ulcer effects of HPS were evaluated using an animal model of ulcerative lesions induced by acetic acid. The effects of antioxidant factors, anti-inflammatory cytokines, and mucosal blood flow regulatory factor levels in the gastric tissue homogenate of rats were analyzed for the bioactivities of HPS. The results showed that, compared with the acetic acid-induced ulcerated group, the ulcer inhibition rate of HPS-treated rats was significantly increased. The pathological findings suggested that mucosal regeneration, cell migration, and inflammatory cell infiltration were decreased, and collagen fibers were significantly reduced. Extensive granulation tissue proliferation indicated the healing stage was initiated, suggesting a good prognosis. The oxidative stress status of the gastric ulcer rats was improved, the levels of TNF-α and IL-6 were significantly decreased, and the levels of PGE-2 and NO were increased (P < 0.05). HPS-80-H may be a promising ingredient for incorporation into functional foods or nutritional supplements for the prevention of gastric ulcers.