The causes of "Plateau Phenomenon"in College English learning are analyzed on the basis of the investigation and the study of the Learning Curve.Some solutions to cope with the stagnation are also suggested.It's worth attention that Learning Strategy can be a vital factor to overcome the"Plateau Phenomenon."

Animals ; Heparin ; pharmacology ; Humans ; Ligands ; Lymphatic Metastasis ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasms ; metabolism ; pathology ; Oligosaccharides ; metabolism ; Selectins ; metabolism ; physiology ; Signal Transduction

Objective:To analyze the clinical effect and safety of Lingdan tablets and Wuling capsules in the treatment of alopecia areate. Methods:Totally 84 patients with alopecia areate were divided into the observation group and the control group with 42 ones in each. Minoxidil tincture was used for external in the two groups. The control group were treated with 0. 9 g Lindan tablets, tid, for 4 months and the treatment group was additionally treated with 0. 99 g Wuling capsules,po,tid, for 4 months. The changes in the area and position of trichomadesis, light pull test, the tissue growth score and Pittsburgh Sleep Quality Index ( PSQI) score were compared before and after the treatment. Results:The efficacy of the observation group was better than that of the control group(P<0. 05). Af-ter the treatment, the evaluated indices in the two groups were lower than those before the treatment(P<0. 01), and the reduction of the observation group was more significant than that of the control group(P<0. 01) . There was no notable adverse reaction appeared in the observation group. Conclusion:Lingdan tablets and Wuling capsules can improve sleeping quality, promote the growth of halr and enhance the curative effect.

· AIM: To study the expression of basic fibroblast growth factor (bFGF) receptor protein in human lens epithelial cells (HLECs). METHODS: Immunohistochemistry was used to detect the level of bFGF receptor protein and image analysis was adopted to perform the relative quantitative analysis on it. · RESULTS: There was bFGF receptor protein in HLECs accordingl to both qualitative and quantitative analysis. · CONCLUSION: bFGF receptor protein exists in HLECs and it is the material foundation for bFGF to improve the proliferation of HLECs.

Objective To elucidate the role of human bone marrow stromal cells (hBMSC) in combination with exogenous cytokines such as stem cell factor(SCF) and FLT 3 ligand (FL) in supporting the in vitro expansion of CD 34 + cells purified from cord blood.Methods CD 34 + cells were isolated from umbilical cord blood by using a high gradient magnetic cell sorting system(MACS),expanded in combination with SCF,IL3 (interleukin 3),IL 6 (interleukin 6),FL,EPO (erythropoietin),and were planted onto the pre established irradiated (20Gy) stroma layer(hBMSC plus combinations of cytokines) respectively.On day 10,total cells were counted, and hematopoietic progenitor cells were assessed by semisolid culture assay,CD 34 + cells were quantitated by FACS.Results After separation by MACS,the frequency of CD 34 + cells was 92%?0.04%.On day 2,almost all the inoculated cells adhered to the stroma layer,with only a small number in the supernatant.Then,cells in the supernatant increased gradually, but the percentage of CD 34 + cells decreased.Compared with control, expansion fold of CD 34 + cells, CFU GM, BFU E were significantly higher in hBMSC group (P 0.5).Conclusion ① CD 34 + cells from cord blood formed foci adherent to the monolayer and colony forming cells remained in the culture of 10days,indicating that hBMSC can support hematopoiesis in vitro;②using human bone marrow stromal cells in cooperation with exogenous cytokines may be a feasible way to expand hematopoietic stem/progenitor cells.

Objective To compare the biomechanical properties between the two-level fixation by im- plantation of pedicle-screws into the adjacent upper and lower vertebrae of the fractured vertebra and the three-level fixation by implantation of pedicle screws into the fractured vertebra and its adjacent upper and lower vertebrae in the treatment of thoracolumbar burst fractures.Methods Eight fresh frozen calf spines were used in this study.Each specimen was tested in four models:intact model as the control,L1 burst fracture model,two-level fixation model, and three-level fixation model.The L1 burst fracture model was created on a biaxial material testing machine (MTS858 Bionix test system,America).During the experiment,the flexion,extension,bilateral bending and axial rotation loadings were applied to the specimens and the range of motion(ROM)was measured with a three-dimensional laser analysis apparatus and the stiffness was calculated subsequently.One-way statistical analysis was used.Results The ROMs under six different loadings in the fracture model became larger obviously(P＜0.05)and the stiffness decreased(P＜0.05).The ROMs in both fixation models were smaller than those in the other models(P＜0.01)and the stiffness increased distinctly(P＜0.05).There were no significant differences in ROMs and stiffness between the two-level fixation and three-level fixation models(P＞0.05).Conclusion Two-level fixation provides similar biomechanical stability as three-level fixation does in the reconstruction of unstable thoracolumbar fractures.

Abstract: Objective　To analyze the genotype of carbapenemase resistance genes and their genetic homology in multidrug-resistant Acinetobacter baumannii, and to provide a theoretical basis for guiding the rational use of antibiotics and controlling the prevalence of nosocomial infections. Methods A total of 83 multidrug-resistant Acinetobacter baumannii isolated from patients in the intensive care unit (ICU) and environmental specimens in the Sixth People's Hospital of Nantong from July 2020 to December 2021 were collected. The bacteria were identified and subjected to drug sensitivity tests using the BioMérieux DL96-Ⅱ automatic bacterial identification susceptibility system. The carbapenemase-related drug resistance gene types were detected using the polymerase chain reaction (PCR) method, and clones were analyzed by pulsed field gel electrophoresis (PFGE). Results The types of 83 ICU Acinetobacter baumannii specimens include sputum (43 strains), broncholavage fluid (20 strains), and surfaces of objects such as ventilators (20 strains). The resistance rates of all strains to imipenem, tetracycline, gentamicin, amikacin and ciprofloxacin were 100%, 32.5%, 38.6%, 41.0% and 77.1% respecitively, while the resistance rates to others such as ticarcillin and clavulanate were greater than 95%. All strains carried were detected to carry OXA-23 and OXA-51 genes, while OXA-24, OXA-58, IMP-1, VIM, IMP-4, SIM and NDM-1 resistance genes were all negative. PFGE homology analysis confirmed that 83 strains of Acinetobacter baumannii, with counts of 12, 18, 12, 13, 10, 6, 7, 5 respectively, mainly A, B, C, D, E clones, the rest were sporadic clones. Conclusions The carbapenem resistant Acinetobacter baumannii isolated from our ICU are widely drug-resistant to commonly used antimicrobial drugs, with B clone strain being the major prevalent strain. Carrying OXA-23 and OXA-51 genes may be an important reason for the resistance of Acinetobacter baumannii to carbapenem antibiotics in our ICU. Rational use of antimicrobial drugs, enhanced monitoring of bacterial resistance, and effective control of the generation and further spread of drug-resistant strains should be emphasized.

This article was aimed to study the mechanism of interaction between human serum albumin (HSA) and zinc ions, in order to provide the information on the secondary structure modification of HSA and the thermodynamics parameters using circular dichroism (CD) and isothermal titration calorimetry (ITC). CD and ITC were applied in the study. The concentration of HSA were 0.025 mmol·L-1, 0.05 mmol·L-1, 0.1 mmol·L-1, and 0.2 mmol·L-1, respectively. The concentration of zinc ion was 5 mmol·L-1. The CD analysis revealed that the secondary structure modification of HSA differed depending on the concentration of HAS. And the content ofα-helix was inversely proportional to the concentration of HSA. When the concentration of HSA was 0.2 mmol·L-1, the content ofα-helix was special. A series of thermodynamics parameters including association constants (Kb), stoichiometry (N), entropy (ΔS) and enthalpy (ΔH) were investigated by ITC analysis. And two types of binding sites were observed when ZnSO4(mmol·L-1)?HSA (mmol·L-1)= 5?0.2. The secondary structure modification of HSA interacting with zinc ions depended on the concentration of HSA, a dramatic reduction ofα-helix was detected when the concentration of HSA attained 0.2 mmol·L-1. And the protein hydrophobicity reduction and peptide chains expansion were equally observed at this concentration. The ITC analysis also revealed endothermic and exothermic binding sites in the ZnSO4-HSA interaction when ZnSO4 (mmol·L-1)?HSA (mmol·L-1)= 5?0.2, indicating that the endothermic sites were specific but not preferential for zinc ions interactions. These results provided theoretical supports for the application of Zn2+ to open the endothermic sites of HSA.

Objective:To study the inhibition of astragaloside on the proliferation of human keloid fibroblasts. Methods: Com-pared with that of normal skin, the expression of transforming growth factor-β( TGF-β) and its transduction factors Smad in the human keloid fibroblasts was detected. The optimal concentration was screened by MTT after HFF-1 human skin fibroblast was infected with astragaloside at different concentrations. The mRNA expression of Smad2, Smad3, Smad4 and Smad7 in the fibroblasts was studied by using real-time. The protein expression of TGF-βRⅡ, Smad2, Smad3, Smad4 and Smad7 in the fibroblasts was detected by using Western blot. Results: Compared with that of normal skin tissue, the expression of Smad protein was significantly increased ( P <0. 05) in the human keloid fibroblasts, and there was no significant difference in the TGF-βRⅡ expression (P>0. 05). The optimal concentration of astragaloside was 0. 5μg·ml-1 . The expression level of Smad2 protein in the two groups was significantly increased, and the level of Smad3 expression was significantly decreased (P<0. 05). Conclusion:Astragaloside can inhibit the formation of fi-broblast possibly through Smad2 over-expression and Smad3 inhibition in the TGF-β/Smad signal transduction pathway.

Objective To evaluate the clinical efficacy of hypocaloric enteral nutrition in patients with acute severe traumatic brain injury (TBI).Methods A total of 100 patients with severe TBI [Glasgow Coma Scale (GCS) 3-8 points] were enrolled and randomly divided into hypocaloric enteral nutrition group (hypocaloric group, 41.86-62.79 kJ · kg-1 · d-1) and traditional caloric enteral nutrition group (traditional caloric group, 104.65-125.58 kJ · kg-1 · d-1) ,50 patients per group.The enteral nutrition was given at 24-72 hours postoperatively.The changes of total serum protein (TP), serum-albumin (ALB), plasma hemoglobin (Hb), fasting blood glucose (Glu) and major gastrointestinal tract complications were observed and compared at 7 and 14 days after enteral nutrition support.Results Levels of TP, ALB and Hb were lowered in both groups at 7 and 14 days after nutritional support but showed no statistical difference (P ＞ 0.05).Glu was (6.37 ± 1.02) mmol/L in hypocaloric calorie group, significantly lower than (7.35 ± 1.70) mmol/L in traditional caloric group at day 7 after nutritional support (P ＜ 0.05).At 7 and 14 days after nutrition support, nausea, regurgitation, vomiting and complication incidence showed no significant difference between hypocaloric calorie group and traditional caloric group after nutritional support (P ＞ 0.05), but abdominal distension, diarrhea and stomach retention rate in hypocaloric group were significantly lower than those in traditional caloric group (P ＜ 0.05).Conclusion Hypocaloric enteral nutrition can significantly reduce the stress hyperglycemia, abdominal distention, diarrhea, gastric retention and other gastrointestinal symptoms in patients with acute severe TBI.