Effects of perceived teacher support on motivation and engagement amongst Chinese college students: Need satisfaction as the mediator.

College students' motivation and engagement are regarded as essential factors to promote their academic development and wellbeing. However, motivation and engagement among college students appear to decline after they enter the university. Guided by the framework of self-determination theory, this study attempted to explore a motivational model of how three dimensions of perceived teacher support (autonomy, structure, and involvement) related to student motivation and class engagement, using need satisfaction as a mediator. Drew on a survey of the perceptions of 705 Chinese university students, the results showed that besides structure, both autonomy support and involvement positively related to students' need satisfaction. Further, need satisfaction was positively associated with autonomous motivation, controlled motivation, and class engagement and negatively linked with amotivation. Yet, only autonomous motivation was positively predicted for class engagement. Need satisfaction and the chain from need satisfaction to autonomous motivation were found to be the significant mediators. The practical implications of educational practices are discussed.

Cyclic tensile machine with wide speed range for in situ neutron/X-ray scattering study on elastomers.

A tensile machine is designed for in situ scattering investigation of elastomers in the cyclic tensile process. The specimen is stretched by two linearly moving clamps in the opposite direction; thus, the center of the specimen is kept stationary during the tensile test. With this configuration, either X-ray scattering or neutron scattering can be carried out easily. A high speed direct current motor is used to drive the machine, providing a wide tensile speed range from 1.28 × 10-3 mm/s to 102.4 mm/s. Cyclic tension is achieved by program controlled motor rotation, and the engineering stress-strain curve can be saved automatically in each cycle. Moreover, an independent displacement sensor is used to check the possible accumulative error of position during cyclic tension. The orientation change of multiwall carbon nanotube filled silicon rubber is investigated by small angle neutron scattering to test the machine, which shows that the machine is capable of combining the cyclic tensile test with in situ scattering measurement.

Contrast Variation Small Angle Neutron Scattering Investigation of Micro- and Nano-Sized TATB.

Small angle neutron scattering (SANS) with contrast variation was used to characterize the fractal behavior and embedded porosity of micro/nano-sized 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) crystallites, gauging the effects of particle sizes on the microstructural features. Scattering results reveal that the external surface of micro-sized TATB crystallites are continuous and smooth interfaces and their internal pores display a surface fractal structure (surface fractal dimension 2.15 < DS < 2.25), while the external surface of nano-sized TATB particles exhibit a surface fractal structure (surface fractal dimension 2.36 < DS < 2.55) and their internal pores show a two-level volume fractal structure (large voids consist of small voids). The voids volume fraction of nano-sized TATB particles are found increased distinctively when compared with micro-sized TATB particles on length scale between 1 nm and 100 nm. Specific surface areas are also estimated based on Porod law method, which are coincident with Brunauer-Emmett-Teller (BET) measurements. The contrast variation technique distinguishes the information of internal voids from external surface, suggesting SANS is a powerful tool for determining the microstructural features, which can be used to establish the relationship between microstructures and properties of micro/nano-energetic materials.

Rotational Effects of Nanoparticles for Cooling down Ultracold Neutrons.

Due to quantum coherence, nanoparticles have very large cross sections when scattering with very cold or Ultracold Neutrons (UCN). By calculating the scattering cross section quantum mechanically at first, then treating the nanoparticles as classical objects when including the rotational effects, we can derive the associated energy transfer. We find that rotational effects could play an important role in slowing down UCN. In consequence, the slowing down efficiency can be improved by as much as ~40%. Since thermalization of neutrons with the moderator requires typically hundreds of collisions between them, a ~40% increase of the efficiency per collision could have a significant effect. Other possible applications, such as neutrons scattering with nano shells and magnetic particles,and reducing the systematics induced by the geometric phase effect using nanoparticles in the neutron Electric Dipole Moment (nEDM), are also discussed in this paper.

Genetic association of cytokines polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in the Chinese.

AIM: To characterize gene polymorphism of several cytokine gene in-patients with AIH and PBC and to analyze the difference of the polymorphism distribution between Chinese patients and healthy controls. METHODS: The study population consisted of 62 patients with AIH, and 77 patients with PBC. The genetic profile of four cytokines was analyzed by restriction fragment length polymorphism after specific PCR amplification (PCR-RFLP) or sequence-specific primers PCR (SSP-PCR). The analyzed gene polymorphism included interleukin-1 (IL-1) (at position +3 953 and IL-1RN intron 2), IL-6 (at position -174), IL-10 promoter (at position -1 082, -819, and -592). The control group consisted of 160 healthy blood donors. RESULTS: The majority of Chinese people including patients and healthy controls exhibited IL-1B 1,1 genotype, and there was no significant difference in AIH, PBC patients and controls. There were highly statistically significant differences in the distribution of the IL-1RN gene polymorphism between the patients with PBC compared with controls. The frequency of IL-1RN 1,1 was significantly higher (90.9% vs 79.4%, P = 0.03) and the frequency of IL-1RN 1,2 was significantly lower in PBC patients (6.5% vs 17.5%, P = 0.01). No statistical difference was observed between AIH patients and controls. All of the 160 healthy controls and 62 cases of AIH patients exhibited IL-6-174GG genotype, and there were four cases, which expressed IL-6-174GC genotype in 77 cases of PBC patients. The frequency of IL-6-174GC was markedly significantly higher in PBC patients compared with controls (5.2% vs 0%, P = 0.004). No statistically significant difference was found in the distribution of IL-10 promoter genotype in AIH and PBC patients compared with controls. CONCLUSION: The polymorphisms of IL-1RN and IL-6 -174G/C appear to be associated with PBC in Chinese patients.

Correlation of Chlamydia pneumoniae infection with primary biliary cirrhosis.

AIM: To evaluate the association between Chlamydia pneumoniae (Cpn) infection and primary biliary cirrhosis (PBC). METHODS: Cpn IgG and IgM were determined by enzyme-linked immunosorbent assay (ELISA) in 41 well-established PBC patients and two race-matched control groups (post-hepatitis cirrhosis, n = 70; healthy controls, n = 57). RESULTS: The mean level and seroprevalence of Cpn IgG in PBC group and post-hepatitis cirrhosis (PHC) group were significantly higher than those in healthy controls (46.8+/-43.4 RU/mL, 49.5+/-45.2 RU/mL vs 28.3+/-32.7 RU/mL; 68.3%, 71.4%, 42.1%, respectively; P<0.05). There was a remarkably elevated seroprevalence of Cpn IgM in patients with PBC (22.0%) compared to the PHC and healthy control (HC) groups. For the PBC patients versus the HCs, the odds ratios (ORs) of the presence of Cpn IgG and IgM were 2.7 (95% CI 0.9-6.1) and 5.1 (95% CI 1.4-18.5), respectively. Though there was no correlation in the level of Cpn IgG with total IgG in sera of patients with PBC (r = -0.857, P = 0.344>0.05), Cpn IgM was related with the abnormally high concentrations of total IgM in PBC group. CONCLUSION: The results of this study do not support the hypothesis that infection with Chlamydia pneumoniae may be a triggering agent or even a causative agent in PBC, but suggest that Chlamydia pneumoniae infection probably contributes to the high level of IgM present in most patients with PBC.

[Analysis of HLA alleles polymorphism in Chinese patients with primary biliary cirrhosis].

OBJECTIVE: To investigate the frequencies of human leuckocyte antigens (HLA) -A, B and DRB1 alleles in Chinese patients with primary biliary cirrhosis (PBC) using polymerase chain reaction-based techniques, and to assess the correlation of HLA molecules with other clinical and laboratory profiles. METHODS: Genotyping of HLA-A, B, and DRB1 were performed in 65 well-characterized patients with primary biliary cirrhosis and 431 healthy controls with PCR amplification with sequence-specific primers (PCR-SSP). RESULTS: The frequency of DRB1*0701 was increased to 29.2% compared with 13.9% in the controls (PC < 0.05, OR = 2.55, 95% CI: 1.4 approximately 4.6). No association was found with HLA-DRB1*08 which had been constantly reported. The A*2 allele (53.8%) was more frequent in the PBC patient group but without a significant statistical difference. The frequencies for the other A, B and DRB1 alleles were similar between patients and healthy controls. There was no difference between patients with or without DRB1*0701 in some clinical and laboratory profiles. CONCLUSION: Susceptibility to primary biliary cirrhosis in Chinese is associated with DRB1*0701 allele and differs from people in North America, South America, North Europe and even in Japan, but the association is not restricted to any particular subgroup of patients. Valine at position 78 of HLA DRbeta1 may play an important role in the pathogenesis of primary biliary cirrhosis.

[The value of antimitochondrial antibody and its subtypes in the diagnosis of primary biliary cirrhosis].

OBJECTIVE: A study on the value of antimitochondrial antibody (AMA) and its subtypes anti-M2, anti-M4, and anti-M9 in diagnosing primary biliary cirrhosis (PBC). METHODS: Antimitochondrial antibody was detected by indirect immunofluorescence and anti-M2, anti-M4 and anti-M9 by Western blotting. AMA and anti-M2 of 78 PBC patients, of 35 non-PBC hepato-biliary disease patients and 20 healthy controls were studied and anti-M2, anti-M4 and anti-M9 were studied in 30 of the 78 PBC patients. RESULTS: 96.2% (75/78) of PBC patients were AMA positive and 94.9% (74/78) of PBC patients were anti-M2 positive. Only three among the 35 non-PBC patients were positive for AMA (one with very low titre). None of the 35 non-PBC patients was anti-M2 positive. AMA and anti-M2 were negative in all the healthy controls. Among the 30 anti-M2 positive patients, 16 patients were anti-M4 positive (16/30, 53.3%) and 4 patients were anti-M9 positive (4/30, 13.3%). CONCLUSION: AMA and its subtypes (special anti-M2) are important sero-immunological markers for the diagnosis of PBC.

Cytotoxic T lymphocyte associated antigen-4 gene polymorphisms confer susceptibility to primary biliary cirrhosis and autoimmune hepatitis in Chinese population.

AIM: To investigate the association between Chinese patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and the polymorphisms of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene promoter (-318) and exon 1 (+49). METHODS: CTLA-4 promoter (-318 T/C) and exon1 (+49A/G) polymorphisms were genotyped via restriction fragment length polymorphism methods in 62 Chinese AIH patients, 77 Chinese PBC patients and 160 healthy controls. RESULTS: We found a significant association in CTLA-4 gene exon1 49 A/G polymorphism between PBC patients and controls (P = 0.006) and the frequency of G alleles was significantly increased in comparison with controls (P = 0.0046, OR = 1.8). We also found the frequency of C alleles in promoter -318 was significantly increased in AIH patients compared with controls (P = 0.02, OR = 0.41). Although the genotype distribution of the CTLA-4 exon 1-promoter gene was not significantly different between AIH and PBC patients and controls, the occurrence of GG-CC was increased in two groups of patients (AIH: 32.3%, PBC: 37.7%, control: 22.5%). CONCLUSION: Polymorphisms of CTLA-4 gene probably confer susceptibility to AIH and PBC in Chinese population.

[Study on the relationship of CTLA-4 -318, +49 polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in a Chinese population].

OBJECTIVE: To investigate the association between Chinese patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and the polymorphisms of cytotoxic T lymphocyte -associated antigen-4 (CTLA-4) gene promoter (-318) and exon 1 (+49). METHODS: The CTLA-4 promoter (-318 T/C) and exon 1 (+49A/G) polymorphisms were genotyped via restriction fragment length polymorphism methods in 62 Chinese AIH patients, 77 Chinese PBC patients and 160 healthy controls. RESULTS: There was no difference in the distribution of CTLA-4 promoter -318 T/C polymorphisms between AIH patients and controls, but the C allele frequency was significantly increased in patients with AIH, compared to controls (P=0.02, OR=2.43). The distribution of CTLA-4 gene exon 1 49 A/G genotypes exhibited significant difference between PBC patients and controls (P=0.006), and the frequency of G allele showed a significant increase in PBC group as compared with controls (P=0.0046, OR=1.8). Although the genotype distribution of the CTLA-4 exon 1-promoter gene displayed no significant difference between AIH and PBC patients and controls, the occurrence of GG-CC was increased in the patients of the two groups (AIH: 32.3%, PBC: 37.7%; control: 22.5%). CONCLUSION: The above findings suggest that the polymorphisms of CTLA-4 gene probably confer susceptibility to AIH and PBC in the Chinese population.

[Genetic association of vitamin D receptor polymorphisms with primary biliary cirrhosis and autoimmune liver diseases on Chinese].

OBJECTIVE: To study the association between the polymorphisms of vitamin D receptor (VDR) gene and autoimmune liver diseases and (AIH) and primary biliary cirrhosis (PBC) in Chinese. METHODS: PCR-RELP was used to investigate the polymorphisms in exon 2, and exon 7 to exon 9 of VDR among 49 AIH patients, 58 PBC patients, and 160 healthy controls, all Chinese. VDR polymorphisms were assessed by FokI, BsmI, ApaI, and TaqI endonucleases restriction fragment length polymorphism analysis after specific polymerase chain reaction (PCR) amplification. RESULTS: The distribution of VDR gene polymorphism in Chinese was similar to those in Koreans and Japanese, and different from those in the Germans and Spaniards. The percentage of ff phenotype carriers was significantly higher in the AIH patients than in the healthy controls (34.7% vs. 48.1%, chi(2) = 5.47, P = 0.019) and the percentage of Ff phenotype carriers was lower in the AIH patients than in the healthy controls (34.7% vs. 48.1%, P = 0.057). The percentage of Bb phenotype carriers was significantly lower in the PBC patients than in the healthy controls (5.2% vs. 17.5%, P = 0.021) and. the percentage of bb phenotype carriers was significantly higher in the PBC patients than in the healthy controls (94.8% vs. 80.6%, chi(2) = 6.52, P = 0.01). We also detected a significant association of the BsmI polymorphisms in PBC patients in comparison with controls (P = 0.01). Furthermore we found the difference in the FokI, BsmI, ApaI, and TaqI genotype distribution between Chinese health controls and Caucasian health controls. CONCLUSION: There is a significant association between FokI polymorphism and AIH and a significant association between the BsmI polymorphisms and PBC in Chinese.

[Prediction and identification of autoepitopes of PDC-E2 specific CD8+ CTL in primary biliary cirrhosis patients].

OBJECTIVE: To identify autoepitopes of E2 subunit of pyruvate dehydrogenase complex (PDC-E2) specific CD8+ CTL in primary biliary cirrhosis (PBC) patients. METHODS: An online database SYFPEITHI was applied to predict HLA-A*0201 restricted epitopes which located in PDC-E2 30-50 aa and 150-190 aa where B-cell epitopes clustered with CD4+ T-cell epitopes. T2 cell line reconstitution and stabilization assay, induction of specific CTL lines from peripheral blood mononuclear cells (PBMCs) of patients with PBC and cytotoxicity of peptides-induced CTL were performed to screen the epitopes from those candidates. RESULTS: Five potential epitopes were predicted by database. Of the 5 candidates, two peptides 159-167 aa and 165-174 aa, with highly binding activity to HLA-A*0201 molecules, could stimulate PBMCs from most HLA-A*0201 positive PBC patients to proliferate and peptide-induced CTL lines showed specific cytotoxicity. CONCLUSION: Peptides of KLSEGDLLA (159-167 aa) and LLAEIETDKA (165-174 aa) in the inner lipoyl domain of PDC-E2 are HLA-A*0201 restricted CD8+ CTL immunodominant epitopes in PBC.

[Genetic association between interleukins gene polymorphisms with primary biliary cirrhosis in Chinese population].

OBJECTIVE: To determine the relationship between polymorphisms in the genes encoding IL-1, IL-6, and IL-10 with primary biliary cirrhosis (PBC) in Chinese population. METHODS: Whole-blood samples were taken from 77 patients with PBC and 160 healthy controls. DNA was extracted and the polymorphisms at positions IL-1 +3953, IL-1RN intron 2, IL-6 -174, and IL-10 -1082, -819, and -592 were determined by using sequence-specific polymerase chain reaction (SSP) or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The frequency of IL-1RN1,1 allele in PBC group was significantly higher than in control group (90.9% vs 79.4%, P=0.026), and the frequency of IL-1RN1,2 in PBC group was significantly lower than in control group (6.5% vs 18.8%, P=0.013). There was no significant difference in the frequence of IL-1RN*2 allele between PBC group and control group (P=0.06). Of the 77 patients with PBC, 4 patients were IL-6 -174GC, 73 were IL-6 174GG. All the 160 health controls are IL-6 -174GG (P=0.0036). The frequence of IL-6 -174C allele in PBC group was significantly higher than that in control group (P=0.0038). No significant differences of polymorphisms for IL-1 +3953 and IL-10 (-1082, -819 and -592) were found between PBC group and control group. CONCLUSION: The polymorphisms of IL-1RN and IL-6 -174G/C appear to be associated with PBC, and the polymorphisms of IL-1 +3953 and IL-10 promoter gene are not associated with PBC in a Chinese population.

[Clone of M2 autoantigens from human sources and evaluation of measurement of M2 autoantibodies in diagnosis of primary biliary cirrhosis].

OBJECTIVE: To evaluate the value of measurement of M2 autoantibodies in diagnosis of primary biliary cirrhosis (PBS). METHODS: M2 autoantibodies were detected by ELISA combined with western-blot. RESULTS: Thirty-two cases presented positive M2 autoantibodies, including 20 cases of PBC, 9 liver diseases of unknown etiology, 1 autoimmune hepatitis and 1 drug-induced liver injury. CONCLUSIONS: M2 autoantibodies show good sensitivity and specificity to diagnosis of PBC. It should be used as a powerful and specific maker for the diagnosis of PBC

[The relationship between Chlamydia pneumoniae infection and primary biliary cirrhosis].

OBJECTIVE: The aim of this study was to evaluate the association between Chlamydia pneumoniae (CP) infection and primary biliary cirrhosis (PBC). METHODS: Chlamydia pneumoniae IgG and IgM were determined by enzyme-linked immunosorbent assay (ELISA) in 41 well-established PBC patients and two race-matched control groups, PHC, n = 70; healthy controls, HC, n =57). RESULTS: The mean levels and seroprevalence of CP IgG in PBC group and PHC group were significantly higher than in the HC [(46.8 +/- 43.4) RU/ml, (49.5 +/- 45.2) RU/ml vs (28.3 +/- 32.7) RU/ml, P = 0.042 and P < 0.001 respectively; 68.3%, 71.4% vs 42.1%, chi2 values were 5.389 and 11.110 respectively]. There was a markedly elevated seroprevalence of CP IgM in patients with PBC (22.0%) compared with the PHC and HC groups. The odds ratios (ORs) for the presence of CP IgG and IgM for the PBC patients versus the HC were 2.7 (95% CI 0.9 to 6.1) and 5.1 (95% CI 1.4 to 18.5). Though there was no correlation in the level of CP IgG with total IgG in sera of patients with PBC (r=-0.857, p=0.344), CP IgM was related with the abnormally high concentrations of total IgM in the PBC group. CONCLUSIONS: The results of this study do not support the hypothesis that infection with Chlamydia pneumoniae may be a triggering agent for PBC, but suggest that Chlamydia pneumoniae infection probably contributes to the high level of IgM presented in most of the patients with PBC

[Genetic association of tumor necrosis factor (TNF)-alpha polymorphisms with primary biliary cirrhosis and autoimmune liver diseases in a Chinese population].

OBJECTIVE: Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are two autoimmune diseases of unknown etiology. Genetic factors appear to be involved in the pathogenesis of both diseases. Tumor necrosis factor (TNF)-alpha is one of the proinflammatory cytokines and immunomodulators, and is implicated in the pathogenesis of AIH and PBC. In this study, we studied the association between Chinese patients with AIH, PBC and the polymorphisms in promoter-region polymorphisms of the TNF-alpha gene at position -308 and -238. METHODS: We have investigated four candidate gene loci in 49 patients with AIH, 58 patients with PBC, and 160 healthy controls. The polymorphisms were assessed by the PCR specifically for the single-nucleotide polymorphisms. RESULTS: We found the difference in the TNF-alpha gene at position -308 genotype distributions between Chinese health controls and Caucasian health controls. Although the percent of TNF-alpha*2 was decrease on PBC patient group (10.34% vs. 16.88%), there was no significant difference between PBC patients and health control in the Chinese. There were also no significant differences between AIH and health control on the TNF-alpha gene at position -308 and -238. CONCLUSION: Our findings suggest that the TNF-alpha promoter-region polymorphisms distribution is different between differe of ethnic groups; there are no genetic links of the TNF-alpha promoter-region polymorphisms to AIH and PBC in Chinese.

[A study on the relationship between interleukin-10 promoter polymorphism and autoimmune liver disease].

OBJECTIVE: To investigate whether three biallelic polymorphisms at the position -592, -819 and -1082 in the promoter region of the IL-10 gene were associated with the incidence of autoimmune liver disease. METHODS: The IL-10 -592 and IL-10-1082 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphisms analysis (PCR-RFLP), while polymerase chain reaction- sequence specific primer (PCR-SSP) assay was used to detect IL-10 -819 polymorphisms. RESULTS: Among 54 Chinese patients with AIH or 77 Chinese patients with PBC versus healthy controls, the frequency of AA, GA genotypes at IL-10 gene promoter -1082 position was 87.0% or 83.1% versus 90.0%, 13.0% or 16.9% versus 10.0%, respectively (P > 0.05), the GG genotype in Chinese populations is absent; the frequency of CC, CT, TT genotypes at IL-10 gene promoter -819 position was 11.11% or 9.1% versus 8.1%, 44.4% or 53.3% versus 45.0%, 44.4% or 37.7% versus 46.9%, respectively (P > 0.05); the frequency of CC, CA, AA genotypes at IL-10 gene promoter -592 position was 4.9% or 14.3% versus 10.0%, 51.2% or 53.3% versus 51.9%, 43.9% or 32.5% versus 38.1%, respectively (P > 0.05). No alleles differed significantly in each groups. CONCLUSION: There were no association between IL-10 gene polymorphisms and autoimmune liver disease

Genetic association of vitamin D receptor polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in the Chinese.

BACKGROUND: Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are two autoimmune diseases of unknown etiology. Genetic factors appear to be involved in the pathogenesis of both diseases. Vitamin D has been shown to exert multiple immunomodulatory effects, which acts through its own receptor (VDR). Polymorphisms of VDR had been implicated in several autoimmune diseases. In the present study, the association between Chinese patients with AIH, PBC and the polymorphisms in exon 2, intron 8 and exon 9 of vitamin D receptor genes was studied. METHODS: Four candidate gene loci were investigated in 49 patients with AIH, 58 patients with PBC, and 160 healthy controls. The VDR polymorphisms were assessed by FokI, BsmI, ApaI, and TaqI endonuclease digestion after specific polymerase chain reaction (PCR) amplification. RESULTS: The result show a significant difference in FokI polymorphism between AIH patients and controls (chi(2) = 5.47, P = 0.019), and a significant association in BsmI polymorphisms between PBC patients and controls (chi(2) = 6.52, P = 0.01). Furthermore the distribution of FokI, BsmI, ApaI, and TaqI gene types differed between Chinese healthy controls and Caucasian healthy controls. CONCLUSION: It is suggested that there is a genetic link of VDR polymorphisms to autoimmune liver diseases such as AIH and PBC in Chinese patients. Further studies are needed to elucidate the mechanisms by which VDR polymorphisms contribute to the lose of immune tolerance in autoimmune diseases.