“双一流”建设背景下物理化学课程教学改革与实践

在“双一流”建设的背景下,物理化学教学秉承“以学生为中心,以目标为导向”的教学理念,通过问题引导的启发式教学模式,从科学发展的历史角度出发,阐述相关概念、定律,并将学科前沿和应用案例引入课堂,培养学生的创新意识和科学思维方法。通过翻转课堂和分组讨论的方式,培养学生的自学能力和团队协作精神。

Comparative Skin Histology of Frogs Reveals High-elevation Adaptation of the Tibetan Nanorana parkeri

Adaptations to extreme environmental conditions are intriguing. Animal skin, which directly interacts with external environment, plays diverse and important roles in adaptive evolution. The thin and bare skin of amphibians is sensitive to external environmental conditions and, thus, it facilitates investigations into adaptations for living in extreme environments. Herein, we compare the structures of skin in four anuran species living at elevations ranging from 100 m to 4500 m to assess phenotypic innovations in the skin of Nanorana parkeri, which lives at extremely high elevations. Analyses reveal similar basic skin structures, but N. parkeri differs from the other species by having more epidermal capillaries and granular glands, which correlate highly with responses to hypoxia and/or ultraviolet(UV) radiation. Further intraspecific comparisons from frogs taken at ~4500 m and ~2900 m reveal that all of the changes are fixed. Changes occurring only in the higher elevation population, such as possessing more skin pigments, may represent local adaptations to coldness and/or UV radiation. These results provide a morphological basis for understanding further the molecular adaptations of these frogs.

Effects of bar-transgenic rice on the intestinal microflora of the mice (<i>Mus musculus</i>)

Microbial molecular ecology approaches were used to the effects of Bar-transgenic rice on Intestinal Micro-flora of the Mice (Mus musculus). Kunming mice (Mus musculus) of 100 SPF-grade (20 g ± 2 g), half of which were male and the other half female, were randomly divided into five groups with four replications per group and five mice per replication to assess the safety of Bar-transgenic rice. Five diets meetinging or exceeding the minimum nutrient requirement were fed for 180 days. After 90 days, parental generation (P) was bred to produce the first filial generation (F1). Each generation was fed for 180 days. On the 180th day, five mice from each group were randomly sampled, and their intestinal contents were collected for DNA isolation. The V3 region of the 16S rDNA was amplified by polymerase chain reaction (PCR) and analyzed via denaturing gradient gel electrophoresis (DGGE). The resulting PCR-DGGE band number (bacterial species) was counted, and the banding patterns were analyzed by calculating the Sorenson’s pairwise similarity coefficients (Cs), an index used to measure bacterial species found among all samples. The sequence analysis of bands was performed to identify the intestinal predominant microflora of the mice. The intergroup Cs values of the samples across all groups did not differ (P > 0.05) from each other. The effect of Bar-transgenic rice on the intestinal microflora of the mice was considered insignificant.

Detection of 16S rRNA Methylase Genes in Gram-Negative Bacilli Isolated from Hospitals in Changchun, China

Methylation of 16S rRNA is an important mechanism of aminoglycoside resistance among gram-negative pathogens. In this report, 16S rRNA methylase genes were amplified using PCR among gram-negative bacillus isolates from hospitals in the Changchun area of China and 16S rRNA methylase genotypes (armA, rmtB, rmtA, rmtC, rmtD, and npmA) were identified by direct sequencing. Fifty of the isolates (43.1%) harbored 16S rRNA methylase genes. The common 16S rRNA methylase genes were armA and rmtB (12.1% and 31.0%, respectively), whereas the rmtA, rmtC, rmtD, and npmA genes were absent from the sample. It suggests that the predominant 16S rRNA methylase genes among gramnegative bacilli in the Changchun area are armA and rmtB.

Improved iterative convergence method in Q-ary LDPC coded high order PR-CPM

The Q-ary low-density parity-check（LDPC） coded high order partial response continuous phase modulation（PR-CPM） with double iterative loops is investigated. This scheme shows significant improvements in power and bandwidth efficiency, but at the expense of long iterative decoding delay and computational complexity induced by the improper match between the demodulator and the decoder. To address this issue, the convergence behavior of Q-ary LDPC coded CPM is investigated for the Q=2 and Q〉2 cases, and an optimized design method based on the extrinsic information transfer chart is proposed to improve the systematic iterative efficiency. Simulation results demonstrate that the proposed method can achieve a perfect tradeoff between iterative decoding delay and bit error rate performance to satisfy real-time applications.

右侧子宫圆韧带平滑肌瘤误诊为腹股沟斜疝一例

腹股沟疝作为腹部外科常见疾病之一,人群发病率为1%~5%,全世界每年实施2000余万台次腹股沟疝修补术,女性约占10%[1,2,3]。诊断通常可以通过病史和体格检查确定,当有不典型症状或缺乏明确体征表现时应进一步完善腹部超声、CT或MRI检查[4]。由于女性腹股沟管内有子宫圆韧带通过,因此圆韧带囊肿、脂肪瘤、平滑肌瘤、肉瘤等常与腹股沟疝相混淆,其表现均可为腹股沟区无痛性肿物,同时也可伴有指压还纳感,造成术前诊断困难甚至误诊[5,6,7,8]。现将一术前诊断为腹股沟疝的子宫圆韧带平滑肌瘤病例情况及处理报道如下。