"Corpus" is a systematic collection of digital, authentic language data in written or oral form. In the area of German as a foreign language, learner corpora, which are defined as the collection of language products of learners, play a major role in research and teaching. At the Hanoi University in 2017, the project which started to set up a Vietnamese learner corpus has been completed since September 2021. The corpus includes written texts of students from the German department at Hanoi University. This paper introduces the corpus and presents how useful this text collection has been for teaching and research.

This brief paper proposes a new algorithm to train interpolation Gaussian radial basis function (RBF) networks in order to solve the problem of interpolating multivariate functions with equally spaced nodes. Based on an efficient two-phase algorithm recently proposed by the authors, Euclidean norm associated to Gaussian RBF is now replaced by a conveniently chosen Mahalanobis norm, that allows for directly computing the width parameters of Gaussian radial basis functions. The weighting parameters are then determined by a simple iterative method. The original two-phase algorithm becomes a one-phase one. Simulation results show that the generality of networks trained by this new algorithm is sensibly improved and the running time significantly reduced, especially when the number of nodes is large.

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This study aims to assess the acute and sub-chronic oral toxicity of “Tri 02” powder in experimental animals. According to World Health Organization Guidance, acute toxicity study was conducted using Swiss mice. LD50 was determined by Litchfield-Wilcoxon method, and sub-chronic toxicity of “Tri 02” at two doses (2.4 g/kg b.w/day and 7.2 g/kg b.w/day) was assessed in Wistar rats for four uninterrupted weeks. Abnormal behavior, toxic symptoms, and death were observed for 7 consecutive days to assess the effects of acute toxicity. The general behavior of the rats was observed daily, and their body weight was recorded weekly. Hematological analysis and biochemical analysis were conducted before treatment, and at 2 and 4 weeks of treatment. Macroscopic examination and histopathological examination of several organs were conducted at the end of the treatment period. The results suggested that “Tri 02” at the highest dose used for mice (187.5 g/kg b.w) did not show acute toxicity and the LD50 was determined. In terms of the sub-chonic toxicity test, after oral administration of “Tri 02” powder, hematological parameters, hepato-renal functions and microscopic images of liver and kidney at both doses were similar to the control group. In conclusion, “Tri 02” powder did not produce the acute and subchronic oral toxicity in experimental animals.

Imbalance between exogenous damaging agents and protective factors in the gastro-duodenum tract can lead to peptic ulcer disease. Herbal medicines could be an effective treatment to human gastric ulcers. This study aimed to investigate the protective effect of AGAR-HP hard capsules on cysteamine-induced gastric-duodenal ulcers in experimental rats. The animals were divided into five treatment groups: Group 1 (control) and group 2 (model) were treated with distilled water, group 3 received esomeprazole at 10 mg/kg, group 4 received AGAR-HP at 0.074 g/kg, and group 5 received AGAR-HP at 0.221 g/kg. All the rats were treated for seven consecutive days. On day 7, peptic-duodenal ulcer were induced by oral cysteamine 400 mg/kg. The number of rats with the ulcer, the number of ulcers per rat, and the ulcer index of each group were recorded. Compared to group 2, AGAR-HP at high dose reduced the mean number of ulcers and the ulcer index under macroscopic and microscopic examinations. These parameters also decreased in the group of AGAR-HP low doses compared to the cysteamine control group. AGAR-HP hard capsules showed some protective effect on cysteamine-induced gastric ulcers in experimental rats.