Was sagen uns Deutschlernende über ihre Deutschlandbilder? Potenziale und Perspektiven der Nationenbilderforschung für Forschung und Praxis am Beispiel dreier Studien im ostasiatischen Kontext

Im vorliegenden Artikel werden drei Forschungsarbeiten über Deutschlandbilder chinesischer und japanischer Deutschstudierender verglichen mit dem Ziel, die forschungsmethodische und unterrichtspraktische Relevanz der Nationenbilderforschung aufzuzeigen. Bei zwei der Studien liegt der Fokus auf unterrichtlichen Einflüssen auf die Deutschlandbilder, während die dritte Studie die Wirkungen eines bis zu einjährigen Studienaufenthalts in Deutschland beschreibt. Im Vordergrund des Vergleichs stehen Gemeinsamkeiten und Unterschiede des methodischen Vorgehens und der erzielten Ergebnisse. Darüber hinaus werden Bezüge zur sozialpsychologischen Forschung über Einstellungen und Einstellungsveränderungen hergestellt. Schließlich werden einige Schlussfolgerungen sowohl für die Forschungs- als auch die Unterrichtspraxis gezogen und Ausweitungen des forschungstheoretischen und -methodologischen Rahmens im Fach DaF angeregt.The following article compares three studies about images of Germany from Chinese and Japanese students of the German language, with the aim of demonstrating the relevance of research about national images for research methods and teaching practice. Two of the studies focus on the influences of the learning procedure on images of Germany, whereas the third study describes the effects of studying abroad in Germany for up to one year. The focus of the comparison is on the similarities and differences of the methodical procedure and the achieved results. Moreover, connections are made to research of attitudes and attitude change in social psychology. Finally, some conclusions are drawn for research and teaching practice, as well as encouraging an extension of the theoretical and methodological research framework in the subject of German as a foreign language

Was sagen uns Deutschlernende über ihre Deutschlandbilder? Potenziale und Perspektiven der Nationenbilderforschung für Forschung und Praxis am Beispiel dreier Studien im ostasiatischen Kontext

Im vorliegenden Artikel werden drei Forschungsarbeiten über Deutschlandbilder chinesischer und japanischer Deutschstudierender verglichen mit dem Ziel, die forschungsmethodische und unterrichtspraktische Relevanz der Nationenbilderforschung aufzuzeigen. Bei zwei der Studien liegt der Fokus auf unterrichtlichen Einflüssen auf die Deutschlandbilder, während die dritte Studie die Wirkungen eines bis zu einjährigen Studienaufenthalts in Deutschland beschreibt. Im Vordergrund des Vergleichs stehen Gemeinsamkeiten und Unterschiede des methodischen Vorgehens und der erzielten Ergebnisse. Darüber hinaus werden Bezüge zur sozialpsychologischen Forschung über Einstellungen und Einstellungsveränderungen hergestellt. Schließlich werden einige Schlussfolgerungen sowohl für die Forschungs- als auch die Unterrichtspraxis gezogen und Ausweitungen des forschungstheoretischen und -methodologischen Rahmens im Fach DaF angeregt

Correlation of LC3 and the recruitment of dendritic cell and the formation of TLS in colorectal cancer and its clinical significance

Background and purpose: It has been recognized as a complex problem in tumor therapy to deal with the tumor immune escape, and over-activated autophagy can cause the increase of tumor surface antigen, which participates in anti-tumor immunity. In this study, the expressions of microtubule-associated protein light chain 3 (LC3), mature dendritic cell (mDC) and the formation of tertiary lymphoid structure (TLS), an essential autophagy factor in colorectal cancer, were detected in clinical samples. The results had important clinical implications and provided new insights for enhancing anti-tumor immunity. Methods: Immunohistochemical EnVision method was used to detect the expressions of LC3, DC-lamp and the formation of TLS in cancer tissues and normal mucosal tissues of 179 patients with T2 stage high-risk and T3 stage colorectal cancer who underwent surgical resection at Binzhou Medical University Hospital from January 2016 to June 2017. Western blot and real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) were used to detect the expressions of LC3, NY-ESO-2, lymphotoxin-beta (LTβ), CC chemokine ligand 21 (CCL21), CXC chemokine ligand 13 (CXCL13) and interleukin-17 (IL-17) in TLS+ and TLS- colorectal cancer tissues. Then the correlation and clinical significance were analyzed. Log-rank test was used to compare the prognostic differences between groups, and COX proportional risk regression model was used for multivariate survival analysis. Results: Clinical samples showed that the expressions of LC3 and DC-lamp were higher in colorectal cancer tissues than in normal mucosa tissues (P<0.05), and the expressions of LC3 and DC-lamp were positively correlated (P<0.05). The protein and mRNA expressions of LC3, NY-ESO-2, LTβ, CXCL13 and CCL21 were higher in TLS+ group than in TLS- group. The expression of IL-17 was higher in the TLS- group than in the TLS+ group (P<0.05). The expression of LC3 was positively correlated with TLS/germinal center (GC)+ and TLS/GC- subtypes and positively correlated with the expression of NY-ESO-2, LTβ, CXCL13 and CCL21 (P<0.05). The expression of DC-lamp was higher in TLS/GC+ and TLS/GC- subtype groups than in the other two subgroups (P<0.05), and there was a positive correlation. Kaplan-Meier and COX regression models showed that LC3, DC-lamp, TLS and lymph node metastasis were closely related to the prognosis of patients with colorectal cancer, and they were independent risk factors for the prognosis of colorectal cancer. Conclusion: The abnormal expression of LC3 in colorectal cancer can activate mDC to recruit lymphocytes and promote the expression and maturation of TLS, ultimately affecting the prognosis of patients

Genomic surveillance indicates clonal replacement of hypervirulent Klebsiella pneumoniae ST881 and ST29 lineage strains in vivo

The emergence of hypervirulent Klebsiella pneumoniae (hvKp) poses a significant public health threat, particularly regarding its carriage in the healthy population. However, the genomic epidemiological characteristics and population dynamics of hvKp within a single patient across distinct infection episodes remain largely unknown. This study aimed to investigate the clonal replacement of hvKp K2-ST881 and K54-ST29 lineage strains in a single patient experiencing multiple-site infections during two independent episodes. Two strains, designated EDhvKp-1 and EDhvKp-2, were obtained from blood and cerebrospinal fluid during the first admission, and the strain isolated from blood on the second admission was named EDhvKp-3. Whole-genome sequencing, utilizing both short-read Illumina and long-read Oxford Nanopore platforms, was conducted. In silico multilocus sequence typing (MLST), identification of antimicrobial resistance and virulence genes, and the phylogenetic relationship between our strains and other K. pneumoniae ST881 and ST29 genomes retrieved from the public database were performed. Virulence potentials were assessed through a mouse lethality assay. Our study indicated that the strains were highly susceptible to multiple antimicrobial agents. Plasmid sequence analysis confirmed that both virulence plasmids, pEDhvKp-1 (166,008 bp) and pEDhvKp-3 (210,948 bp), belonged to IncFIB type. Multiple virulence genes, including rmpA, rmpA2, rmpC, rmpD, iroBCDN, iucABCD, and iutA, were identified. EDhvKp-1 and EDhvKp-2 showed the closest relationship to strain 502 (differing by 51 SNPs), while EDhvKp-3 exhibited 69 SNPs differences compared to strain TAKPN-1, which all recovered from Chinese patients in 2020. In the mouse infection experiment, both ST881 EDhvKp-1 and ST29 EDhvKp-3 displayed similar virulence traits, causing 90 and 100% of the mice to die within 72 h after intraperitoneal infection, respectively. Our study expands the spectrum of hvKp lineages and highlights genomic alterations associated with clonal switching between two distinct lineages of hvKP that successively replaced each other in vivo. The development of novel strategies for the surveillance, diagnosis, and treatment of high-risk hvKp is urgently needed

Identification of risk factors for infection after mitral valve surgery through machine learning approaches

BackgroundSelecting features related to postoperative infection following cardiac surgery was highly valuable for effective intervention. We used machine learning methods to identify critical perioperative infection-related variables after mitral valve surgery and construct a prediction model.MethodsParticipants comprised 1223 patients who underwent cardiac valvular surgery at eight large centers in China. The ninety-one demographic and perioperative parameters were collected. Random forest (RF) and least absolute shrinkage and selection operator (LASSO) techniques were used to identify postoperative infection-related variables; the Venn diagram determined overlapping variables. The following ML methods: random forest (RF), extreme gradient boosting (XGBoost), Support Vector Machine (SVM), Gradient Boosting Decision Tree (GBDT), AdaBoost, Naive Bayesian (NB), Logistic Regression (LogicR), Neural Networks (nnet) and artificial neural network (ANN) were developed to construct the models. We constructed receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) was calculated to evaluate model performance.ResultsWe identified 47 and 35 variables with RF and LASSO, respectively. Twenty-one overlapping variables were finally selected for model construction: age, weight, hospital stay, total red blood cell (RBC) and total fresh frozen plasma (FFP) transfusions, New York Heart Association (NYHA) class, preoperative creatinine, left ventricular ejection fraction (LVEF), RBC count, platelet (PLT) count, prothrombin time, intraoperative autologous blood, total output, total input, aortic cross-clamp (ACC) time, postoperative white blood cell (WBC) count, aspartate aminotransferase (AST), alanine aminotransferase (ALT), PLT count, hemoglobin (Hb), and LVEF. The prediction models for infection after mitral valve surgery were established based on these variables, and they all showed excellent discrimination performance in the test set (AUC > 0.79).ConclusionsKey features selected by machine learning methods can accurately predict infection after mitral valve surgery, guiding physicians in taking appropriate preventive measures and diminishing the infection risk

The Comparison of Biotreatment and Chemical Treatment for Odor Control during Kitchen Waste Aerobic Composting

Odor ΨΩγemission has become mathvariant="normal" mathvariant="sans-serif-bold-italic" an important issue in kitchen waste management. Ammonia and hydrogen sulfide are the two most important odor sources as they contribute malodor and can cause health problems. As biotreatment and chemical treatment are two majorly applied technologies for odor control, in this study, they were used to remove ammonia and hydrogen sulfide and the performance of each process was compared. It was found that chemical absorption could efficiently eliminate both ammonia and hydrogenmathvariant="script" sulfide, and the removal efficiencies of ammonia and hydrogen sulfide highly depended on the pH of the adsorbent, contacting time, and gas and solution ratio (G/S). The ammonia-removal efficiency reached 100% within less than 2 s at G/S 600 and pH 0.1. The complete removal of hydrogen sulfide was achieved within 2 s at G/S 4000 and pH 13. Biotrickling filter showed better ability for hydrogen sulfide removal and the removal efficiency was 91.9%; however, the ammonia removal was only 73.5%. It suggests that chemical adsorption is more efficient compared to biotreatment for removing ammonia and hydrogen sulfide. In the combination of the two processes, biotrickling filter followed by chemical adsorption, the final concentrations of ammonia and hydrogen sulfide could meet the Level 1 standard of Emission Standards for Odor Pollution (China). The study provides a potential approach for odor control during kitchen waste aerobic composting

Synthetic Aperture Radar Image Despeckling Based on Multi-Weighted Sparse Coding

Synthetic aperture radar (SAR) images are inherently degraded by speckle noise caused by coherent imaging, which may affect the performance of the subsequent image analysis task. To resolve this problem, this article proposes an integrated SAR image despeckling model based on dictionary learning and multi-weighted sparse coding. First, the dictionary is trained by groups composed of similar image patches, which have the same structural features. An effective orthogonal dictionary with high sparse representation ability is realized by introducing a properly tight frame. Furthermore, the data-fidelity term and regularization terms are constrained by weighting factors. The weighted sparse representation model not only fully utilizes the interblock relevance but also reflects the importance of various structural groups in despeckling processing. The proposed model is implemented with fast and effective solving steps that simultaneously perform orthogonal dictionary learning, weight parameter updating, sparse coding, and image reconstruction. The solving steps are designed using the alternative minimization method. Finally, the speckles are further suppressed by iterative regularization methods. In a comparison study with existing methods, our method demonstrated state-of-the-art performance in suppressing speckle noise and protecting the image texture details

Effects of temperature, CO content, and reduction time on the selective reduction of a limonitic laterite ore

The production of nickel and cobalt from laterite ores has gained increasing attention as their demands continue to rise. This study evaluated the effects of temperature (700–1000 °C), CO content (10–70 vol%), and reduction time (10–90 min) on the selective reduction of a limonitic laterite ore and examined the mechanism of the selective reduction. SEM/EDS observation shows that the ore consists of goethite, hematite and small particles of clinochlore cemented by amorphous iron-rich silicate phase. Nickel and cobalt occur with goethite mineral in this ore. It was observed that fine grains of Fe-Ni-Co alloy dispersed within magnetite phase in reduced samples. XRD and XPS analyses show increased Fe2SiO4 generation with increasing reduction temperature, and elements nickel and cobalt were capatured in Fe2SiO4 according to SEM/EDS observation. Reduction at temperature above 850 °C resulted in a sharp increase in Fe2SiO4 generation and decrease in the specific surface area of the ore. The morphological and compositional observations indicate that CO content over 20 vol% promoted Fe formation from the laterite ore but hardly enhanced the formation of Ni and Co. The difference in equilibrium CO partial pressures for the formation of Fe, Ni, Co accounts for selective reduction. The current study suggests that selective reduction can be achieved by controlling reduction temperature and gas composition. Under the optimum condition of 850 °C, 20 vol% CO-80 vol% CO2 and 60 min, the degrees of metallisation of iron, nickel, and cobalt reduction were 17.5%, 87.3%, and 91.5%, respectively

Dapagliflozin prevents oxidative stress-induced endothelial dysfunction via sirtuin 1 activation

Recent studies have demonstrated that dapagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, prevents endothelial dysfunction; however, direct effects of dapagliflozin on the endothelium under oxidative stress and the underlying mechanism of action are not completely understood. This study aimed to define the role and related mechanisms of dapagliflozin in hydrogen peroxide (H2O2)-induced endothelial dysfunction. The endothelium-dependent vasorelaxation effect of dapagliflozin was assessed in an organ bath study. Endothelial dysfunction was assessed using protein expression level and phosphorylation of endothelial nitric oxide synthase (eNOS), nitric oxide (NO), reactive oxygen species (ROS), senescence-associated beta-galactosidase (SA-β-gal) activity, and senescence marker proteins (p21, p53). Co-immunoprecipitation and protein acetylation were performed to detect protein interactions. Dapagliflozin exerted a direct vasorelaxant effect in the aortic rings of C57BL/6 J mice. Furthermore, there was a significant improvement in endothelium-dependent vasorelaxation in dapagliflozin-treated diabetic mice compared to vehicle controls. Moreover, intracellular ROS levels and ONOO- levels, increased by H2O2, were reduced by dapagliflozin. Importantly, dapagliflozin inhibited H2O2-induced senescence in the human umbilical vein endothelial cells (HUVECs), as indicated by reduced SA‐β‐gal, p21, and p53. Mechanistically, dapagliflozin reversed the H2O2-mediated inhibition of eNOS serine phosphorylation and sirtuin 1 (SIRT1) expression in endothelial cells. In particular, SIRT1-mediated eNOS deacetylation is reportedly involved in dapagliflozin-enhanced eNOS activity. These findings indicate that dapagliflozin ameliorates endothelial dysfunction by restoring eNOS activity, restoring NO bioavailability, and reducing ROS generation via SIRT1 activation in oxidative stress-stimulated endothelial cells