[Effects of selenium valence states and application concentrations on plant growth, ascorbate-glutathione cycle in Citrus junos cv. Ziyang Xiangcheng]. / 硒的价态与浓度对香橙幼苗生长和AsA-GSH循环的影响.

Potted Citrus. junos cv. Ziyang Xiangcheng seedlings were used to study the effects of selenium (Se) valence states (Se6+ and Se4+) on plant growth and antioxidants and antixodases in ascorbate(AsA)-glutathione (GSH) cycle. The results showed that Se6+ and Se4+ (from 1.0 mg·L-1 to 8.0 mg·L-1) stimulated the seedling growth by increasing plant height, leaf areas, and fresh or dry mass. Applying Se6+significantly increased plant Se levels mainly in leaf, and applying Se4+ slightly increased Se content mainly in root. Certain valence states and concentrations of Se increased leaf chlorophyll and hydrogen peroxide (H2O2) content. Se6+≤2.0 mg·L-1 treatments enhanced the activates of glutathione reductase (GR) and glutathione peroxidase (GPX), and the contents of GSH and oxidized glutathione (GSSG), while Se6+≥4.0 mg·L-1 treatments reduced the antioxidant contents and antixodase activities of GSH cycle. Moreover, Se4+≤ 2.0 mg·L-1 treatments increased the activities of dehydroascorbate reductase (DHAR) and ascorbate peroxidase (APX), and resulted in higher AsA/[AsA+dehydroascorbic acid (DHA)] ratio. When Se4+≥4.0 mg·L -1, the antioxidant contents and antixodase activities of GSH cycle were increased. Together, this study showed that different valence states and application concentrations of Se showed different influences on AsA-GSH cycle in citrus, and 2.0 mg·L-1 Se6+ and 4.0 mg·L-1 Se4+ were the best concentrations for plant growth.

Dysregulation of miRNA-21 and their potential as biomarkers for the diagnosis of cervical cancer.

OBJECTIVE: This study aimed to characterize the miR-21 and evaluated its clinical significance. METHODS: Total RNA was extracted from 30 pairs of fresh specimens of cervical cancer and normal tissues. The expression levels of the miR-21-3p and miR-21-5p were detected by quantitative reverse transcriptase polymerase chain reaction, with U6 as the internal reference gene. We compared the expression of miR-21-3p and miR-21-5p between study group and control groups, the association between miRNA expression level and clinicopathological factors was investigated. RESULTS: The expression of miR-21-3p and miR-21-5p in HPV positive cervical cancer samples was significantly upregulated compared to that in the paired normal samples (P < 0.05); A multivariate analysis demonstrated that the expression of miR-21 was associated with clinicopathological parameters, including depth of invasion and lymph node metastasis. CONCLUSIONS: MiR-21 upregulation is associated with aggressive progression and poor prognosis in cervical cancer, which suggests that miR-21 might be identified as an independent marker for predicting the clinical outcome of cervical cancer patients.

A low-surface energy carbon allotrope: the case for bcc-C6.

Graphite may be viewed as a low-surface-energy carbon allotrope with little layer-layer interaction. Other low-surface-energy allotropes but with much stronger layer-layer interaction may also exist. Here, we report a first-principles prediction for one of the known carbon allotropes, bcc-C6 (a body centered carbon allotrope with six atoms per primitive unit), that should have exceptionally low-surface energy and little size dependence down to only a couple layer thickness. This unique property may explain the existence of the relatively-high-energy bcc-C6 during growth. The electronic properties of the bcc-C6 thin layers can also be intriguing: the (111), (110), and (001) thin layers have direct band gap, indirect band gap, and metallic character, respectively. The refrained chemical reactivity of the thin layers does not disappear after cleaving, as lithium-doped (Li-doped) 3-layers (111) has a noticeably increased binding energy of H2 molecules with a maximum storage capacity of 10.8 wt%.

Characteristics of bacterial vaginosis infection in cervical lesions with high risk human papillomavirus infection.

UNLABELLED: High risk human papillomavirus (HPV) infection is the major cause of cervical cancer. Bacterial vaginosis (BV) is considered as the most prevalent vaginal imbalance affecting women of reproductive age. However, the relationship between HPV and BV infection is unclear. This study aimed to assess the prevalence of human papillomavirus (HPV) infection combined with bacterial vaginosis (BV) infection in Shanghai suburbs and evaluate associations between bacterial vaginosis with HPV infection, cervical intraepithelial neoplasia (CIN) and cervical cancer. METHODS: From October 1, 2009 to October 31, 2013, a total number of 3502 women who visited Fengxian Hospital, Southern Medical University were enrolled in this study. All participants gave informed consent and agreed to HPV, BV, chlamydia, mycoplasma and thinprepcytologic test (TCT). In addition, all women took histopathologic examination under colposcopy. Statistical analyses were done using SPSS 17.0 for windows (IBM). In present study the overall BV-positive rate was 9.25%. The top three high risk HPV types were listed as follows (in descending order): HPV16, 52, 58. Moreover, our data showed BV infection tended to occur in the HPV positive women, HPV infection also tended to occur in the BV positive women. Most of the women who present HPV with BV infection were younger than 30 years old. We also found that CIN and cervical cancer occurred mainly in HPV/BV positive and HPV with BV positive group. BV infection and HPV infection may haveconsistency or synergies. HPV with BV infection may increase the incidence of CIN and cervical cancer.

Two dimensional Dirac carbon allotropes from graphene.

Using a structural search method in combination with first-principles calculations, we found lots of low energy 2D carbon allotropes and examined all possible Dirac points around their Fermi levels. Three amazing 2D Dirac carbon allotropes have been discovered, named as S-graphene, D-graphene and E-graphene. By analyzing the topology correlations among S-, T, net W graphene and graphene, we found that a general rule is valuable for constructing 2D carbon allotropes that are keen to possess Dirac cones in their electronic structures. Based on this rule, we have successfully designed many new 2D carbon allotropes possessing Dirac cones. Their energy order can be well described by an Ising-like model, and some allotropes are energetically more stable than those recently reported. The related electronic structures of these Dirac allotropes are anisotropy distinguished from those of graphene. Moreover, the fact that D- and E-graphene present Dirac cones suggests that sp hybridization or sp(3) hybridization could not suppress the emerging of Dirac features. Our results demonstrate that the Dirac cone and carrier linear dispersion is a very common feature in 2D carbon allotropes and can exist beyond the limitations of fundamental structure features of graphene.

[The correlation analysis between environmental factors, bone morphogenetic protein-4 and transforming growth factor beta-3 polymorphisms in nonsyndromic cleft lip with or without cleft palate].

OBJECTIVE: To investigate the effects of interactions among environmental factors, bone morphogenetic protein-4 (BMP4) and transforming growth factor beta-3 (TGF-ß(3)) polymorphisms on nonsyndromic cleft lip and cleft palate (NSCLP). METHODS: The data of environmental exposures were collected with questionnaires. Genotypes were determined with techniques of polymerase chain reaction-restriction fragment length polymorphism. Interactions between genes, environmental factors and NSCLP were analyzed using multifactor dimensionality reduction (MDR) method. The interactions were validated by logistic regression analysis. RESULTS: There was no correlation between three single nucleotide polymorphism (SNP) associated with NSCLP. The developmental accident of NSCLP had higher risk in the interaction between BMP4 T538C, maternal passive smoking and infection in first trimester pregnancy, as well as in the interaction of six factors between TGF-ß(3) G15572-, maternal passive smoking, infections, multivitamin supplement in the first trimester pregnancy, paternal smoking and high risk drinking before realizing pregnancy than in other interactions of environmental factors. The results could be validated by logistic regression analysis. CONCLUSIONS: The NSCLP is induced by the interactions between genes and environmental risk factors.

[Effect of simvastatin on bone morphogenetic protein-2 expression in the periodontal tissue after rat tooth movement].

OBJECTIVE: To investigate the effect of systematic administration of simvastatin on the bone morphogenetic protein-2 (BMP-2) expression in the periodontal tissue after rat tooth movement and on the relapse of tooth movement. METHODS: Orthodontic tooth movement of upper first molar was performed in 32 rats with coil spring for 21 days. The 32 rats were randomly allocated into 4 groups: negative control group (isotonic saline) and three experimental groups (2.5 mg x kg(-1), 5.0 mg x kg(-1) and 10.0 mg x kg(-1)). The simvastatin started to be administered to the experimental groups 1 day before appliances were removed, and once a day there after for 4 weeks. The negative control group received the isotonic saline only. The interdental distance between the first and second maxillary molars were measured, when appliances were removed, and 1 week and 4 weeks after that. After the rats were sacrificed, sections of first maxillary molar and periodontal tissue were studied by immunohistochemistry. RESULTS: The number and percentage of relapse was lower in the three experimental groups than in the negative control group (P < 0.05, P < 0.01). The lower dose was given, the less relapse there was, with the lowerest dose resulting in lowest percentage of relapse (26.81% and 53.38%). BMP-2 expression in experimental groups was higher than in the negative control group, with the lowerest dose group showing the highest expression (P < 0.001). The BMP-2 expression on the tension side was slightly stronger than that on the compression side (P > 0.05). CONCLUSIONS: Systemic administration of simvastatin could decrease the extent of relapse of the orthodontic-moved tooth in rat, and the lower-dose of simvastatin seemed more effective. The possible mechanism for this may be that simvastatin functions by increasing the expression of BMP-2 in the periodontal tissue, accelerating the osteoblast activity and promoting bone formation.

[The relationship between cbfalpha1 and the mechanism of the bone remodeling in the process of orthodontic tooth movement].

PURPOSE: To perform qualitative and quantitative analyses of core binding factor alpha1 (cbfalpha1) in periodontal tissue during the experimental rat tooth movement process and to investigate the active mechanism of cbfalpha1 in the osteoblast differentiation. METHODS: 42 male Wistar rats aged 8 weeks were divided into 7 groups (0,1,3,5,7,10 and 14 days groups) in random, 6 rats in each group. 42 rats were perfused and sacrificed at the 1st, 3rd, 5th, 7th, 10th and 14th day. All specimens were fixed, then proceeded with HE and cbfalpha1 immunohistochemical staining. The results were analyzed by SPSS11.0 software package for Dunnett test, and the histological changes of cbfalpha1 in periodontal tissue were evaluated. RESULTS: In the periodontal ligament(PDL) of non orthodontic treatment group, the expression of cbfalpha1 was lower; the expression of cbfalpha1 in every experimental groups increased firstly and decreased later; the expression of cbfalpha1 in the surface of the alveolar bone was lower in the compression side than in the tension side, and the number of positive cells was less too (P<0.01). CONCLUSION: cbfalpha1 participates in the process of bone remodeling during the process of orthodontic tooth movement, and it promotes the remodeling and stability of PDL.

[Biomechanical study of open bite treatment with tip forward bend].

OBJECTIVE: To verify whether it is effective to treat open bite cases with tip-forward bend. METHODS: Three-dimensional finite element (TDFE) models of the lower left central incisor and first molar were set up by means of CT. Stress distribution in root, PDL and alveolar bone, and the tendency of the tooth movement were obtained by calculation under different orthodontic forces. RESULTS: (1) The molar model revealed that the tensile stress concentration was at the distal cervix and the compressive stress concentration at mesial cervix. (2) The incisor model showed that the tensile stress was concentrated at apical tip and the compressive stress concentration was at the lingual side of the cervix. (3) The incisor had the tendency to elongate and move lingually. The molar tended to tip mesially and buccally. CONCLUSIONS: Arch wire with tip forward bend depends on the elongation and lingual movement of anterior teeth to treat open bite, but the anchorage molar will incline mesially further, which is not consistent with the mechanism to treat open bite.