High Protonic Conductivity of Three Highly Stable Nanoscale Hafnium(IV) Metal-Organic Frameworks and Their Imidazole-Loaded Products.

Attracted by the exceptional structural rigidity and inherent porous structures of the Hf-based metal-organic frameworks (MOFs), we adopted a rapid synthesis approach to preparing three nanoscale MOFs, Hf-UiO-66 (1), Hf-UiO-66-(OH)2 (2), and Hf-UiO-66-NH2 (3), and systematically explored the water-assisted proton conductivities of the original ones and the post-modified products. Interestingly, the proton conductivities (σ) of all three MOFs exhibit significant temperature and humidity dependence. At 98% RH and 100 °C, their optimal σ values can reach up to 10-3 S·cm-1. Consequently, imidazole units are loaded into 1-3 to obtain related MOFs, Im@1, Im@2, and Im@3, and the σ values of the imidazole-loaded products are boosted to 10-2 S·cm-1. Note that these modifications not only do not change the frameworks of the pristine MOFs but also do not affect their high chemical and water stability. The proton-conductive mechanisms of these MOFs before and after modification have been thoroughly discussed based on structural analyses, N2 and H2O vapor adsorptions, and activation energy values. The excellent structural stability as well as the durability and stability of their proton conduction ability indicate that these MOFs can be used in the field of fuel cells and so on.

[Determination of R(-)- isomer in repaglinide tablets by capillary electrophoresis].

OBJECTIVE: To develop a capillary electrophoresis system for enantiomeric impurity test of repaglinide. METHODS: An uncoated fused silica capillary (50 µm×50 cm, with an effective length of 41 cm) was used. The running buffer was composed of 30 mmol/L NaH2PO4 and 5 mg/ml carboxymethyl-ß-cyclodextrin(pH 3.5). RESULTS: Linear range was 2.00-80.00 µg/ml (correlation coefficient was 0.9993). The average recovery rate was 92.5% to 105.0%. CONCLUSION: The method is simple, accurate and sensitive and it can be used for determination of enantiomeric impurities in repaglinide tablet.

[Determination of enantiomeric impurity in levocetirizine tablets by capillary electrophoresis].

OBJECTIVE: To determine enantiomeric impurity in levocetirizine tablets by using capillary electrophoresis. METHODS: The effects of pH and the concentrations of sulfated-Β-cyclodextrin (S-Β-CD) and buffer salt on chiral resolution were examined with S-Β-CD as chiral selector. RESULTS: A good enantioseparation of cetirizine was achieved with 30 mmol/L NaH2PO4 buffer solution (pH 7.0) containing 20 g/L of S-Β-CD. CONCLUSION: The method developed in the study is sensitive and reliable for determination of enantiomeric impurity in levocetirizine tablets.

[Clinical significance of serum squamous cell carcinoma antigen in the diagnosis, treatment and prognosis of cervical squamous cell carcinoma].

OBJECTIVE: To explore the clinical significance of squamous cell carcinoma antigen (SCC-Ag) in the diagnosis, treatment and prognosis of cervical squamous cell carcinoma. METHODS: The serum SCC-Ag concentrations were measured for 1195 patients with cervical squamous cell carcinoma, 54 patients with non-squamous cell type cervical cancer, 325 patients with cervical intraepithelial neoplasm and 69 healthy women treated at Gynecology Ward of Shengjing Hospital, China Medical University from August 2008 to October 2010. And the correlations with their clinical pathological features of squamous cell carcinoma were analyzed and the changes in the diagnosis, treatment and prognosis monitored. RESULTS: Serum SCC-Ag in patients with cervical squamous cell carcinoma showed a sensitivity of 62.32% and a specificity of 90.10% with the optimal cutoff point of diagnosis at 1.45 µg/L. The differences of pretreatment serum SCC-Ag levels were statistically significant in clinical stage, histological differentiation, depth of invasion and lymph node metastasis (P < 0.01). The posttreatment serum SCC-Ag levels of 106 patients undergoing radical surgery and 264 patients on chemotherapy significantly decreased and were significant different with their pretreatment levels (P < 0.05). There was no relationship of serum SCC-Ag levels and human papillomavirus (HPV) opportunistic infection (all P > 0.05). The best threshold values of pretreatment serum SCC-Ag concentration for predicting early postoperative cervical lymph node metastasis and prognosis of cervical cancer were 2.15 and 12.1 µg/L respectively. CONCLUSION: As a relatively specific tumor maker for cervical squamous cell carcinoma, squamous cell carcinoma antigen is correlated with clinicopathological features of cervical squamous cell carcinoma. And it has important clinical reference values in the diagnosis, prognosis, follow-up evaluation and treatment monitoring of cervical squamous cell carcinoma.

[Association of interferon-γ gene polymorphism and risk of cervical HPV infection].

OBJECTIVE: To investigate the association of interferon (IFN) γ gene polymorphisms and risk and prognosis of HPV cervical infection. METHODS: PCR-ASP was used for detecting IFN-γ rs2430561 polymorphism in 179 HPV positive patients and 328 HPV negative normal controls. RESULTS: The frequency of A allele of 63.7% (228/358) was significantly higher than the frequency of T allele of 36.3% (130/358) in HPV positive group (P = 0.045). The frequencies were 41.3% (74/179) in AA genotype and 14.0% (25/179) in TT genotype, women carrying AA genotype increased the risk of HPV infection compare with those with TT genotype (OR = 1.784, 95% CI: 1.031 - 3.088, P = 0.039). During follow-up, the rate of HPV positive again in AA genotype was 83.8% (62/74), while TT genotype was 20.0% (5/25). In the analysis of Kaplan-Meier, the cumulative HPV negative rates of AA, TA and TT genotype exhibited significantly different (P = 0.008). The cumulative HPV negative rate of AA genotype was the lowest (1.1% - 5.9%). CONCLUSIONS: IFN-γ rs2430561 polymorphisms confer the susceptibility to HPV infection. Women with AA genotype exhibited higher risk of infection and inclined to be continuous status and recurrence after HPV infection.

[Relevant study on apoptosis of cervical cancer HeLa cells induced by paeoniflorin].

OBJECTIVE: To explore the effects of paeoniflorin on the proliferation and apoptosis of HeLa cells. METHODS: HeLa cells treated with paeoniflorin at different concentrations for different hours were assessed by the method of methyl thiazolyl tetrazolium (MTT). Cell apoptosis rate and cycle change were detected by flow cytometry with annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI). The morphological change of HeLa cells was observed by transmission electron microscope (TEM). The expressions of Bcl-2, Bax and Caspase-3 in HeLa cells induced by paeoniflorin were detected by immunocytochemistry. RESULTS: After treatment with different concentrations of paeoniflorin for different hours, the proliferation of HeLa cells was inhibited in a dose and time-dependent manner with an IC50 value of 5054, 2965, 2459 µg/ml at 24, 48 and 72 hours respectively (P < 0.05). After treated by different concentrations of paeoniflorin (control group, 1000 and 2000 µg/ml), apoptosis was induced in HeLa cells at a rate of 0.94%, 10.94% and 13.95% respectively. Such effects were dose-dependent (P < 0.05) and the proportion of HeLa cells in Sphase was under a rising trend. Typical apoptotic changes of HeLa cells under the exposure to paeoniflorin were observed under TEM. There was a lowered expression of Bcl-2 and an elevated expression of Bax and Caspase-3 genes versus the control group after a 48-hour paeoniflorin treatment (P < 0.05). CONCLUSION: Paeoniflorin can significantly induce the apoptosis of HeLa cells through a down-regulation of anti-apoptotic gene Bcl-2 and an up-regulation of pro-apoptotic genes Bax and Caspase-3.