| 1. |
- Guan, Ruicong, et al.
(författare)
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Dexmedetomidine alleviates oxygen and glucose deprivation-induced apoptosis in mesenchymal stem cell via downregulation of MKP-1
- 2022
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Ingår i: Biocell (Mendoza). - : Tech Science Press. - 0327-9545 .- 1667-5746. ; 46:11, s. 2455-2463
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Tidskriftsartikel (refereegranskat)abstract
- Bone marrow mesenchymal stem cell (MSC)-based therapy is a novel candidate for heart repair. But ischemia-reperfusion injury leads to low viability of MSC. Dexmedetomidine (Dex) has been found to protect neurons against ischemia-reperfusion injury. It remains unknown if Dex could increase the viability of MSCs under ischemia. The present study is to observe the potential protective effect of Dex on MSCs under ischemia and its underlying mechanisms. Specific mRNAs related to myocardial ischemia in the GEO database were selected from the mRNA profiles assessed in a previous study using microarray. The most dysregulated mRNAs of the specific ones from the above study were subject to bioinformatics analysis at our laboratory. These dysregulated mRNAs possibly regulated apoptosis of cardiomyocytes and were validated in vitro for their protective effect on MSCs under ischemia. MSCs were pre-treated with Dex at 10 mu M concentration for 24 h under oxygen-glucose deprivation (OGD). Flow cytometry and TUNEL assay were carried out to detect apoptosis in Dex-pretreated MSCs under OGD. The relative expressions of mitogen-activated protein kinase phosphatase 1 (MKP-1) and related genes were detected by quantitative polymerase chain reaction and western blotting. Microarray data analysis revealed that Dex regulates MAPK phosphatase activity. Dex significantly reduced in vitro apoptosis of MSCs under OGD, which suppressed the synthesis level of Beclin1 and light chain 3 proteins. Dex down-regulated MKP-1 expression and attenuated an OGD-induced change in the mitogen activated protein kinase 3 (MAPK3) signaling pathway. Dex increases the viability of MSC and improves its tolerance to OGD in association with the MKP-1 signaling pathway, thus suggesting the potential of Dex as a novel strategy for promoting MSCs efficacy under ischemia.
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| 2. |
- Guan, Ruicong, et al.
(författare)
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Plasma Exosome miRNAs Profile in Patients With ST-Segment Elevation Myocardial Infarction
- 2022
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Ingår i: Frontiers in Cardiovascular Medicine. - : Frontiers Media SA. - 2297-055X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundCirculating microRNAs (miRNAs) have been found to have different expressions in different phases of acute myocardial infarction. The profiles of plasma exosome miRNAs in patients with ST-segment elevation myocardial infarction (STEMI) at 3-6 months postinfarction are unknown. ObjectiveThe aim of this study was to assess the profiles of plasma exosome miRNAs in patients with STEMI in comparison with healthy volunteers and to select specific exosome miRNAs related to pathophysiological changes post-STEMI. MethodsPlasma and echocardiography parameters were collected from 30 patients 3-6 months after STEMI and 30 healthy volunteers. Plasma exosome miRNAs were assessed by using high-throughput sequence (Illumina HiSeq 2500) and profile of the plasma exosome miRNAs was established in 10 patients and 6 healthy volunteers. The specific exosome miRNAs related to heart diseases were selected according to the TargetScan database. The specificity of the selected exosome miRNAs was evaluated in additional 20 post-STEMI patients and 24 healthy volunteers by using quantitative PCR (qPCR). Left ventricular remodeling (LVR) was defined using the European Association of Cardiovascular Imaging criteria according to echocardiography examination. Correlations between expression of the specific miRNAs and echocardiography parameters of LVR were assessed using the Spearman correlation analysis. ResultsTwenty eight upregulated miRNAs and 49 downregulated miRNAs were found in patients 3-6 months after STEMI (p < 0.01) in comparison with the healthy volunteers. The two least expressed and heart-related exosome miRNAs were hsa-miR-181a-3p (0.64-fold, p < 0.01) and hsa-miR-874-3p (0.50-fold, p < 0.01), which were further confirmed by using qPCR and demonstrated significant specificity in another 20 patients with post-STEMI comparing to 24 healthy volunteers [area under the curve (AUC) = 0.68, p < 0.05; AUC = 0.74, p < 0.05]. The expression of hsa-miR-181a-3p was downregulated in patients with LV adverse remodeling in comparison with patients without LV adverse remodeling and healthy volunteers. ConclusionCirculating exosome miR-874-3p and miR-181a-3p were downregulated in patients with STEMI postinfarction. Exosome hsa-miR-181a-3p might play a potential role in the development of LVR in patients with post-STEMI.
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| 3. |
- Hon, Marc, et al.
(författare)
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A close-in giant planet escapes engulfment by its star
- 2023
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 618:7967, s. 917-920
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Tidskriftsartikel (refereegranskat)abstract
- When main-sequence stars expand into red giants, they are expected to engulf close-in planets(1-5). Until now, the absence of planets with short orbital periods around post-expansion, core-helium-burning red giants(6-8) has been interpreted as evidence that short-period planets around Sun-like stars do not survive the giant expansion phase of their host stars(9). Here we present the discovery that the giant planet 8 Ursae Minoris b(10) orbits a core-helium-burning red giant. At a distance of only 0.5 au from its host star, the planet would have been engulfed by its host star, which is predicted by standard single-star evolution to have previously expanded to a radius of 0.7 au. Given the brief lifetime of helium-burning giants, the nearly circular orbit of the planet is challenging to reconcile with scenarios in which the planet survives by having a distant orbit initially. Instead, the planet may have avoided engulfment through a stellar merger that either altered the evolution of the host star or produced 8 Ursae Minoris b as a second-generation planet(11). This system shows that core-helium-burning red giants can harbour close planets and provides evidence for the role of non-canonical stellar evolution in the extended survival of late-stage exoplanetary systems.
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| 4. |
- Huang, Dan, et al.
(författare)
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Ideal half-filled intermediate band position in CuGaS 2 generated by Sb-related defect complex: A first-principles study
- 2019
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Ingår i: Applied Physics Express. - : IOP Publishing. - 1882-0786 .- 1882-0778. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Cu-based chalcopyrite compounds have attracted much attention for photovoltaic application, while some of them (like CuGaS 2 ) have energy gaps greater than the optimal value. An isolated and half-filled intermediate band located at the lower part of its original band gap exhibits in CuGaS 2 with (Sb Ga + Zn Ga ) or (Sb Ga + V Cu ) defect complex, in line with the intrinsic p-type conductivity of the host, revealed from our first-principles calculations. Subsequently, the absorption coefficients of CuGaS 2 can cover the full solar light spectrum efficiently. Based on the defect formation energy calculations, however, these defect complexes are hard to reach a large concentration under equilibrium condition. Nevertheless, non-equilibrium growth methods are suggested to prepare samples inheriting the excellent adsorption coefficients.
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| 5. |
- Li, Yuchen, et al.
(författare)
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Psychological distress among health professional students during the COVID-19 outbreak
- 2021
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Ingår i: Psychological Medicine. - : Cambridge University Press. - 0033-2917 .- 1469-8978. ; 51:11, s. 1952-1954
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Tidskriftsartikel (refereegranskat)abstract
- Background: Due to the drastic surge of COVID-19 patients, many countries are considering or already graduating health professional students early to aid professional resources. We aimed to assess outbreak-related psychological distress and symptoms of acute stress reaction (ASR) in health professional students and to characterize individuals with potential need for interventions.Methods: We conducted a prospective cohort study of 1442 health professional students at Sichuan University, China. At baseline (October 2019), participants were assessed for childhood adversity, stressful life events, internet addiction, and family functioning. Using multivariable logistic regression, we examined associations of the above exposures with subsequent psychological distress and ASR in response to the outbreak.Results: Three hundred and eighty-four (26.63%) participants demonstrated clinically significant psychological distress, while 160 (11.10%) met the criterion for a probable ASR. Individuals who scored high on both childhood adversity and stressful life event experiences during the past year were at increased risks of both distress (ORs 2.00-2.66) and probable ASR (ORs 2.23-3.10), respectively. Moreover, internet addiction was associated with elevated risks of distress (OR 2.05, 95% CI 1.60-2.64) and probable ASR (OR 2.15, 95% CI 1.50-3.10). By contrast, good family functioning was associated with decreased risks of distress (OR 0.43, 95% CI 0.33-0.55) and probable ASR (OR 0.48, 95% CI 0.33-0.69). All associations were independent of baseline psychological distress.Conclusions: Our findings suggest that COVID-19 related psychological distress and high symptoms burden of ASR are common among health professional students. Extended family and professional support should be considered for vulnerable individuals during these unprecedented times.
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| 6. |
- Liu, Lindong, et al.
(författare)
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Intelligent simulation experimental study on influence of air velocity of air supply hood and exhaust hood with vertical push-pull ventilation
- 2019
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Ingår i: Journal of Intelligent & Fuzzy Systems. - : IOS PRESS. - 1064-1246 .- 1875-8967. ; 37:4, s. 4819-4826
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Tidskriftsartikel (refereegranskat)abstract
- The occupational health and safety problems caused by indoor dust and toxic gases in industrial plants are becoming increasingly serious. Vertical push-pull ventilation can effectively control dust and toxic gases and avoid indoor environmental pollution. The velocity of the air supply hood and exhaust hood in the push-pull ventilation intelligent device directly affects the control effect of the dust and toxic gases. However, no scholar has given a reasonable ratio of the air supply and exhaust velocity of the vertical push-pull ventilation device. Therefore, this paper uses the combination of Fluent numerical simulation technology and smoke visualization experiment to explore the best ratio of the air supply and exhaust velocity in the push-pull ventilation flow field. The research shows that the traces of the wind flow obtained by numerical analysis under different k which is the ratio of the air supply and exhaust velocity is consistent with the traces of visualized smoke in the actual experiment; The optimal ratio of air supply and exhaust is k = 1.75, which can effectively guarantee the indoor environment, occupational health and work efficiency of the operators.
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| 7. |
- Xiao, Zhiqiang, et al.
(författare)
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Systematic Engineering of Saccharomyces cerevisiae Chassis for Efficient Flavonoid-7-O-Disaccharide Biosynthesis
- 2023
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Ingår i: ACS Synthetic Biology. - 2161-5063. ; 12:9, s. 2740-2749
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Tidskriftsartikel (refereegranskat)abstract
- Flavonoids are an essential class of secondary metabolites found in plants and possess various nutritional, medicinal, and agricultural properties. However, the poor water solubility of flavonoid aglycones limits their potential applications. To overcome this issue, glycosylation is a promising approach for improving water solubility and bioavailability. In this study, we constructed a flavonoid-7-O-disaccharide biosynthetic pathway with flavonoid aglycones as substrates in Saccharomyces cerevisiae. Subsequently, through metabolic engineering and promoter strategies, we constructed a UDP-rhamnose regeneration system and optimized the UDP-glucose (UDPG) synthetic pathway. The optimized strain produced up to 131.3 mg/L eriocitrin. After this, the chassis cells were applied to other flavonoids, with substrates such as (2S)-naringenin, (2S)-hesperetin, diosmetin, and (2S)-eriodictyol, which resulted in the synthesis of 179.9 mg/L naringin, 276.6 mg/L hesperidin, 249.0 mg/L neohesperidin, 30.4 mg/L diosmin, and 100.7 mg/L neoeriocitrin. To the best of our knowledge, this is the first report on the biosynthesis of flavonoid-7-O-disaccharide.
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| 8. |
- Yu, Wenjin, et al.
(författare)
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Deep Learning-Based Classification of Cancer Cell in Leptomeningeal Metastasis on Cytomorphologic Features of Cerebrospinal Fluid
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is a critical challenge to diagnose leptomeningeal metastasis (LM), given its technical difficulty and the lack of typical symptoms. The existing gold standard of diagnosing LM is to use positive cerebrospinal fluid (CSF) cytology, which consumes significantly more time to classify cells under a microscope.Objective: This study aims to establish a deep learning model to classify cancer cells in CSF, thus facilitating doctors to achieve an accurate and fast diagnosis of LM in an early stage.Method: The cerebrospinal fluid laboratory of Xijing Hospital provides 53,255 cells from 90 LM patients in the research. We used two deep convolutional neural networks (CNN) models to classify cells in the CSF. A five-way cell classification model (CNN1) consists of lymphocytes, monocytes, neutrophils, erythrocytes, and cancer cells. A four-way cancer cell classification model (CNN2) consists of lung cancer cells, gastric cancer cells, breast cancer cells, and pancreatic cancer cells. Here, the CNN models were constructed by Resnet-inception-V2. We evaluated the performance of the proposed models on two external datasets and compared them with the results from 42 doctors of various levels of experience in the human-machine tests. Furthermore, we develop a computer-aided diagnosis (CAD) software to generate cytology diagnosis reports in the research rapidly.Results: With respect to the validation set, the mean average precision (mAP) of CNN1 is over 95% and that of CNN2 is close to 80%. Hence, the proposed deep learning model effectively classifies cells in CSF to facilitate the screening of cancer cells. In the human-machine tests, the accuracy of CNN1 is similar to the results from experts, with higher accuracy than doctors in other levels. Moreover, the overall accuracy of CNN2 is 10% higher than that of experts, with a time consumption of only one-third of that consumed by an expert. Using the CAD software saves 90% working time of cytologists.Conclusion: A deep learning method has been developed to assist the LM diagnosis with high accuracy and low time consumption effectively. Thanks to labeled data and step-by-step training, our proposed method can successfully classify cancer cells in the CSF to assist LM diagnosis early. In addition, this unique research can predict cancer’s primary source of LM, which relies on cytomorphologic features without immunohistochemistry. Our results show that deep learning can be widely used in medical images to classify cerebrospinal fluid cells. For complex cancer classification tasks, the accuracy of the proposed method is significantly higher than that of specialist doctors, and its performance is better than that of junior doctors and interns. The application of CNNs and CAD software may ultimately aid in expediting the diagnosis and overcoming the shortage of experienced cytologists, thereby facilitating earlier treatment and improving the prognosis of LM.
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