Adverse birth outcomes related to concentrations of per- and polyfluoroalkyl substances (PFAS) in maternal blood collected from pregnant women in 1960-1966.

BACKGROUND: Prior animal and epidemiological studies suggest that per- and polyfluoroalkyl substances (PFAS) exposure may be associated with reduced birth weight. However, results from prior studies evaluated a relatively small set of PFAS. OBJECTIVES: Determine associations of gestational PFAS concentrations in maternal serum samples banked for 60 years with birth outcomes. METHODS: We used data from 97 pregnant women from Boston and Providence that enrolled in the Collaborative Perinatal Project (CPP) study (1960-1966). We quantified concentrations of 27 PFAS in maternal serum in pregnancy and measured infant weight, height and ponderal index at birth. Covariate-adjusted associations between 11 PFAS concentrations (>75% detection limits) and birth outcomes were estimated using linear regression methods. RESULTS: Median concentrations of PFOA, PFNA, PFHxS, and PFOS were 6.189, 0.330, 14.432, and 38.170 ng/mL, respectively. We found that elevated PFAS concentrations during pregnancy were significantly associated with lower birth weight and ponderal index at birth, but no significant associations were found with birth length. Specifically, infants born to women with PFAS concentrations ≥ median levels had significantly lower birth weight (PFOS: ß = -0.323, P = 0.006; PFHxS: ß = -0.292, P = 0.015; PFOA: ß = -0.233, P = 0.03; PFHpS: ß = -0.239, P = 0.023; PFNA: ß = -0.239, P = 0.017). Similarly, women with PFAS concentrations ≥ median levels had significantly lower ponderal index (PFHxS: ß = -0.168, P = 0.020; PFHxA: ß = -0.148, P = 0.018). CONCLUSIONS: Using data from this US-based cohort study, we found that 1) maternal PFAS levels from the 1960s exceeded values in contemporaneous populations and 2) that gestational concentrations of certain PFAS were associated with lower birth weight and infant ponderal index. Additional studies with larger sample size are needed to further examine the associations of gestational exposure to individual PFAS and their mixtures with adverse birth outcomes.

Association of non-alcoholic fatty liver disease with total testosterone in non-overweight/obese men with type 2 diabetes mellitus.

PURPOSE: Non-alcoholic fatty liver disease (NAFLD) is considered as both a vital risk factor and a consequence of type 2 diabetes mellitus (T2DM). Low total testosterone (TT) is common in men with T2DM, contributing to increased risks of metabolic diseases. This study aimed to investigate the association between TT levels and the prevalence of NAFLD in men with T2DM. METHODS: In this cross-sectional study, 1005 men with T2DM were enrolled in National Metabolic Management Center (MMC) of First Affiliated Hospital of Wenzhou Medical University between January 2017 and August 2021. NAFLD was diagnosed using ultrasound as described by the Chinese Liver Disease Association. Overweight/obesity was defined as body mass index (BMI) ≥ 25 kg/m2 according to WHO BMI classifications. RESULTS: Individuals without NAFLD had higher serum TT levels than those with NAFLD. After adjustments for potential confounding factors, the top tertile was significantly associated with lower prevalence of NAFLD compared with the bottom tertile of TT level [odds ratio (OR) 0.303, 95% confidence interval (CI) 0.281-0.713; P < 0.001]. The association between TT with NAFLD in individuals with normal weight (OR 0.175, 95% CI 0.098-0.315; P < 0.001) was stronger than in individuals with overweight/obesity (OR 0.509, 95% CI 0.267-0.971; P = 0.040). There was a significant interaction of TT with overweight/obesity (P for interaction = 0.018 for NAFLD). CONCLUSION: Higher serum TT was significantly associated with a lower prevalence of NAFLD in men with T2DM. We found that the relationship of TT and NAFLD was stronger in individuals with non-overweight/obesity.

First-principles investigation of a new 2D magnetic crystal: Ferromagnetic ordering and intrinsic half-metallicity.

The development of two-dimensional (2D) magnetic materials with half-metallic characteristics is of great interest because of their promising applications in spintronic devices with high circuit integration density and low energy consumption. Here, by using density functional theory calculations, ab initio molecular dynamics, and Monte Carlo simulation, we study the stability, electronic structure, and magnetic properties of a OsI3 monolayer, of which crystalline bulk is predicted to be a van der Waals layered ferromagnetic (FM) semiconductor. Our results reveal that the OsI3 monolayer can be easily exfoliated from the bulk phase with small cleavage energy and is energetically and thermodynamically stable at room temperature. Intrinsic half-metallicity with a wide bandgap and FM ordering with an estimated TC = 35 K are found for the OsI3 monolayer. Specifically, the FM ordering can be maintained under external biaxial strain from -2% to 5%. The in-plane magnetocrystalline anisotropy energy of the 2D OsI3 monolayer reaches up to 3.89 meV/OsI3, which is an order larger than that of most magnetic 2D materials such as the representative monolayer CrI3. The excellent magnetic features of the OsI3 monolayer therefore render it a promising 2D candidate for spintronic applications.

In Vitro and In Vivo Antibacterial Activities of Patchouli Alcohol, a Naturally Occurring Tricyclic Sesquiterpene, against Helicobacter pylori Infection.

This study further evaluated the in vitro and in vivo anti-Helicobacter pylori activities and potential underlying mechanism of patchouli alcohol (PA), a tricyclic sesquiterpene. In the in vitro assay, the capacities of PA to inhibit and kill H. pylori were tested on three standard strains at different pH values and on 12 clinical isolates. The effects of PA on H. pylori adhesion (and its alpA, alpB, and babA genes), motility (and its flaA and flaB genes), ultrastructure, and flagellation were investigated. Moreover, the H. pylori resistance to and postantibiotic effect (PAE) of PA were determined. Furthermore, the in vivo effects of PA on H. pylori eradication and gastritis were examined. Results showed that MICs of PA against three standard strains (pH 5.3 to 9) and 12 clinical isolates were 25 to 75 and 12.5 to 50 µg/ml, respectively. The killing kinetics of PA were time and concentration dependent, and its minimal bactericidal concentrations (MBCs) were 25 to 75 µg/ml. In addition, H. pylori adhesion, motility, ultrastructure, and flagellation were significantly suppressed. PA also remarkably inhibited the expression of adhesion genes (alpA and alpB) and motility genes (flaA and flaB). Furthermore, PA treatment caused a longer PAE and less bacterial resistance than clarithromycin and metronidazole. The in vivo study showed that PA can effectively eradicate H. pylori, inhibit gastritis, and suppress the expression of inflammatory mediators (COX-2, interleukin 1ß, tumor necrosis factor alpha, and inducible nitric oxide synthase [iNOS]). In conclusion, PA can efficiently kill H. pylori, interfere with its infection process, and attenuate gastritis with less bacterial resistance, making it a potential candidate for new drug development.

Electrophoretic deposition of graphene oxide reinforced chitosan-hydroxyapatite nanocomposite coatings on Ti substrate.

Electrophoretic deposition (EPD) is a facile and feasible technique to prepare functional nanocomposite coatings for application in orthopedic-related implants. In this work, a ternary graphene oxide-chitosan-hydroxyapatite (GO-CS-HA) composite coating on Ti substrate was successfully fabricated by EPD. Coating microstructure and morphologies were investigated by scanning electron microscopy, contact angle test, Raman spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. It was found GO-CS surface were uniformly decorated by HA nanoparticles. The potentiodynamic polarization test in simulated body fluid indicated that the GO-CS-HA coatings could provide effective protection of Ti substrate from corrosion. This ternary composite coating also exhibited good biocompatibility during incubation with MG63 cells. In addition, the nanocomposite coatings could decrease the attachment of Staphylococcus aureus.

Evaluation of the semen swim-up method for bovine sperm RNA extraction.

Isolation of high-quality RNA is important for assessing sperm gene expression, and semen purification methods may affect the integrity of the isolated RNA. This study evaluated the effectiveness of the sperm swim-up method for seminal RNA isolation. Frozen semen samples in straws from three bulls of proven fertility were purified by the swim-up method. RNA extraction was carried out using the E.Z.N.A.(TM) Total RNA kit II, with non-swim-up sperm as a control. Total sperm RNA was analyzed by UV spectrophotometry, reverse transcription polymerase chain reaction (RT-PCR), and agarose gel electrophoresis, and expression of the sex-determining region on the Y chromosome (SRY), leptin (LEP), and ribosomal protein subunit 23 (RPS23) genes, were determined. 18S RNA was used as a positive control. Fewer somatic cells were found in sperm swim-up samples than in the non-swim-up counterparts (0 x 10(3) vs 17.33 ± 2.52 x 10(3) sperm, P < 0.05). In addition, high-quality RNA was obtained in about 2 h, with no significant difference between groups. Interestingly, the yields of RNA fragments containing ≥200 nucleotides were significantly reduced in sperm swim-up samples (0.92 ± 0.41 x 10(7) sperm) compared with the non-swim-up samples (1.36 ± 0.33 x 10(7) sperm, P < 0.05). After RT-PCR, clear bands representing SRY, LEP, and RPS23 in sperm cDNA were observed on agarose gel electrophoresis. Finally, no bands corresponding to 18S RNA were found in RNA samples from the sperm swim-up group. Our findings suggest that small amounts of sperm RNA can be efficiently extracted from frozen straw semen samples using the swim-up technique.

Serological survey of viral hepatitis markers among newly diagnosed patients with HIV/AIDS in China.

OBJECTIVES: The aim of the study was to determine the seroprevalence and epidemiological features of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection among patients newly diagnosed with HIV/AIDS in China. METHODS: Two thousand and forty patients newly diagnosed with HIV/AIDS from 10 provinces in China were selected during 2009 to 2010. Serum samples obtained from each individual were screened for HBV and HCV serum markers [HBV surface antigen (HBsAg), HBV surface antibody (HBsAb), HBV envelope antigen (HBeAg), HBV envelope antibody (HBeAb), HBV core antibody (HBcAb) and HCV antibody (HCVAb)]; liver function tests were also performed. Demographics and medical histories were collected. RESULTS: Of the 2040 patients, 741 (36.3%) were positive for at least one HBV and HCV serum marker; 300 (14.71%) were HCVAb positive, and 248 (12.16%) were isolated HCVAb positive; 222 (10.9%) were positive for HBsAg; 19 (0.93%) were positive for both HBsAg and HCVAb. The highest prevalence of HBsAg positivity was found in Guangxi (15.31%), followed by Guangdong (15.19%) and Shanghai (14.36%). The highest prevalence of HCVAb positivity was found in Xinjiang (43.18%), followed by Henan (39.06%) and Yunnan (27.36%). The proportion of patients with abnormal liver function in patients positive for HCVAb and/or HBsAg was significantly higher than that in those who were negative for both HCVAb and HBsAg (P < 0.001). CONCLUSIONS: The seroprevalence of HBV and HCV among patients newly diagnosed with HIV/AIDS in China is high. HBsAg and HCVAb positivity prevalences were found to vary significantly in different provinces in China. Patients newly diagnosed with HIV/AIDS and coinfected with HBV and HCV are at higher risk of abnormal liver function. It is necessary to routinely screen for HBV and HCV infection among patients newly diagnosed with HIV/AIDS.

Thoracic paravertebral nerve block combined laryngeal mask airway with preservation of spontaneous breathing can accelerate postoperative recovery.

OBJECTIVE: This study aimed to examine the potential benefits of Thoracic Paravertebral Nerve Block (TPVB) coupled with Laryngeal Mask Airway (LMA) and the maintenance of spontaneous breathing anesthesia, in contrast to general anesthesia utilizing double-lumen endobronchial intubation, on promoting recovery following thoracoscopic surgery. PATIENTS AND METHODS: A randomized controlled trial was carried out involving sixty patients set for Video-Assisted Thoracoscopic Surgery (VATS) at the Affiliated People's Hospital of Jiangsu University from February 2021 to January 2022. Patients were randomized to either the TPVB and LMA with spontaneous breathing anesthesia group (non-intubation group, NI group) or the general anesthesia with double-lumen endobronchial intubation group (Intubation group, I group). The primary outcome measured was the duration of hospitalization. Secondary outcomes included early postoperative rehabilitation indicators, postoperative complications, Visual Analogue Score (VAS), and inflammatory response markers. RESULTS: Patients in the NI group experienced significantly shorter hospital stays than those in the I group (p < 0.05). Early postoperative recovery, assessed by metrics including the first exhaust time, food intake time, first ambulation time, and duration of chest-tube placement, was superior in the NI group (p < 0.05). Postoperative complications such as nausea and vomiting, pulmonary infection, atelectasis, sore throat, and hoarseness, along with cortisol and C-reactive protein (CRP) levels at the end of the operation and 24 h post-operation, and VAS values within the first 12 h post-operation, were significantly lower in the NI group (p < 0.05). However, blood loss, operation time, and VAS values at 24 h and 48 h post-surgery showed no significant differences between the two groups. CONCLUSIONS: Our findings suggest that TPVB, in conjunction with LMA and spontaneous breathing anesthesia, may expedite postoperative recovery in patients undergoing VATS.

[Digital analysis of the correlation between gingival thickness and alveolar bone thickness in the maxillary anterior teeth region].

Objective: To measure the labial gingival thickness and bone lamella thickness in the maxillary anterior area using digital method, and to analyze the correlation between the two, so as to provide a reference for esthetic restoration and implantation treatment of the upper anterior area. Methods: Fifty-seven patients [23 males, 34 females, (25.8±4.5) years old] who planned to receive posterior dental implant restoration were recruited randomly with the inclusion and exclusion criteria in Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University from May 2020 to October 2020. The 3Shape software was used to perform oral scanning, and cone beam CT (CBCT) was taken for each patient. The image data was fitted and registered by the 3Shape software. The gingival thickness at 2 mm below the gingival margin, bone thickness and gingival thickness at 2 and, 4 mm below the crest of the labial alveolar crest in maxillary central incisors, lateral incisors and canines, were measured. Results: The gingival thickness at 2 mm below the gingival margin of maxillary central incisors, lateral incisors and canines was (1.42±0.21), (1.19±0.17) and (1.23±0.20) mm respectively (F=12.47, P<0.001). The gingival thickness at 2 mm below gingival margin and 4 mm below crest of residual ridge in the male patients were (1.31±0.21) and (0.67±0.22) mm, and those in the female patients were (1.26±0.22) and (0.58±0.19) mm respectively, and there were statistically significant differences in the gingival thickness between the "2 mm below gingival margin" group and the "4 mm below crest of residual ridge" group (t=2.01 and 3.97, P<0.05). There was a positive correlation between gingival thickness and alveolar bone thickness at 2 mm and 4 mm below the crest of residual ridge in maxillary anterior region, and the correlation coefficients (r) were 0.387 and 0.344 respectively (P<0.05). Conclusions: Gingival thickness of maxillary anterior area is related to the tooth position and gender. The gingival thickness of men is greater than that of women.The gingival thickness at 2 and 4 mm below the crest of the alveolar crest is positively correlated with the thickness of the alveolar bone.

Fabrication and characterization of elastomeric polyester/carbon nanotubes nanocomposites for biomedical application.

A novel biodegradable polymer elastomer nanocomposite composing of poly(1,8-octanediol-citrate) (POC) polymer matrix and carbon nanotubes (CNTs) additive was successfully fabricated and systematically investigated using Fourier transform infrared (FT-IR), X-ray diffractometer (XRD), differential scanning calorimetry (DSC), tensile test, incubation and cytotoxicity tests. It was found that the addition of CNTs in POC elastomer did not result in any noticeable change in its chemical structure and the amorphous state. However, the tensile strength and elongation at break were greatly improved by the addition of CNTs in POC polymer matrix. It revealed that the swelling ratio and percentage of weight loss of POC/CNTs nanocomposite were lower, compared with the pure POC material. Moreover, the adsorption amount of bovine serum albumin (BSA) increased with an increase of the CNTs mass content in POC matrix revealing the enhanced hydrophilicity of POC/CNTs nanocomposites contributed by the carboxyl of the CNTs. Additionally, the cytotoxicity tests with L929 cell line revealed that the experimental POC/CNTs nanocomposites possessed good in vitro biocompatibility.

A comprehensive biological evaluation of ceramic nanoparticles as wear debris.

Patients are exposed internally to nanoparticles (NPs) by wear mechanisms associated with total joint arthroplasty. This tissue-specific retention implies that the biological evaluation of NPs shall be integrative and niche targeting. Here, we report that ceramic zirconia and silicon nitride NPs interfere with MG63 cells' function and remarkably stimulate the secretion of TNF-α in RAW264.7 cells. However, alumina NPs significantly promote the alkaline phosphatase (ALP) activity of MG63 cells at low concentration and do not show irritation to macrophages. In this study, we prove that ceramic materials at nanoscale are bioactive to cells. These findings also suggest that a more rational paradigm for the biosafety evaluation of NPs than is currently in place is needed before their clinical applications. FROM THE CLINICAL EDITOR: In this study, the authors demonstrate that ceramic nano materials associated with normal wear-and-tear of joint prostheses at nanoscale are bioactive to cells.

A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal instruments.

AIM: To evaluate the bending fatigue lifetime of nickel-titanium alloy (NiTi) and stainless steel (SS) endodontic files using finite element analysis. METHODOLOGY: The strain-life approach was adopted and two theoretical geometry profiles, the triangular (TR) and the square cross-sections, were considered. Both low-cycle fatigue (LCF) lifetime and high-cycle fatigue (HCF) lifetime were evaluated. RESULTS: The bending fatigue behaviour was affected by the material property and the cross-sectional configuration of the instrument. Both the cross-section factor and material property had a substantial impact on fatigue lifetime. The NiTi material and TR geometry profiles were associated with better fatigue resistance than that of SS and square cross-sections. CONCLUSIONS: Within the limitations of this study, finite element models were established for endodontic files to prejudge their fatigue lifetime, a tool that would be useful for dentist to prevent premature fatigue fracture of endodontic files.

A mathematical model for describing the mechanical behaviour of root canal instruments.

AIM: The purpose of this study was to establish a general mathematical model for describing the mechanical behaviour of root canal instruments by combining a theoretical analytical approach with a numerical finite-element method. METHOD: Mathematical formulas representing the longitudinal (taper, helical angle and pitch) and cross-sectional configurations and area, the bending and torsional inertia, the curvature of the boundary point and the (geometry of) loading condition were derived. Torsional and bending stresses and the resultant deformation were expressed mathematically as a function of these geometric parameters, modulus of elasticity of the material and the applied load. As illustrations, three brands of NiTi endodontic files of different cross-sectional configurations (ProTaper, Hero 642, and Mani NRT) were analysed under pure torsion and pure bending situation by entering the model into a finite-element analysis package (ANSYS). RESULTS: Numerical results confirmed that mathematical models were a feasible method to analyse the mechanical properties and predict the stress and deformation for root canal instruments during root canal preparation. CONCLUSIONS: Mathematical and numerical model can be a suitable way to examine mechanical behaviours as a criterion of the instrument design and to predict the stress and strain experienced by the endodontic instruments during root canal preparation.

Controlled synthesis and characterization of ZnSe quantum dots.

Adopting improved metal-organic "Green method," Colloidal ZnSe quantum dots were synthesized by using cheap and low toxic zinc oxide (ZnO) in an organic solvent system of 1-hexadecylamine (HDA), lauric acid (LA) and tri-n-octylphosphine (TOP). The effects of HDA dosage, injection temperature, growth temperature and time on the microstructure and optical properties of ZnSe were studied by means of X-Ray diffraction(XRD), transmission electron microscopy (TEM), spectrofluorometers and ultraviolet spectrophotometer, respectively. The results showed that ZnSe quantum dots with the best range of the size evolution were obtained under the condition of injection at 280 degrees C and growth at 240 degrees C by choosing the optimal parameters of ZnO:HDA:LA= 1:2.1:5.2 and TOPSe = 1 mol/L. Its size became larger and the emission peak shifted obviously to red with increasing the growth time. Meanwhile, the obtained ZnSe was of the wurtzite structure, had good uniformity and fluorescent characteristics.

One-step route to wurtzite-structured ZnS thin nanorods in pure ethylenediamine or mixed solvent.

In the paper, we report one-step synthesis of novel wurtzite-structured ZnS three dimensional architectures assembled from thin nanorods in mixed solvent of ethylenediamine (en) and ethylene glycol, and wurtzite ZnS nanorods in a pure en solvent, both adopting Zn(CH3COO)2 x 2H2O and (NH2)2CS as raw materials. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and selected area electron diffraction were applied to characterize the samples. It was found that the volume ratio of solvents and the concentration of (NH2)2CS played important roles in the formation of wurtzite-structured ZnS nanorods, and the thin wurtzite ZnS nanorods with mean diameter of 6 nm were successfully synthesized. The optical absorption edges of the thin ZnS nanorods were found to be blue-shifted compared with that of the bulk ZnS due to the quantum confinement effect.

Formation of a Key Intermediate Complex Species in Catalytic Hydrolysis of NH3BH3 by Bimetal Clusters: Metal-Dihydride and Boron-Multihydroxy.

The hydrolysis of AB (AB, NH3BH3) with the help of transition metal catalysts has been identified as one of the promising strategies for the dehydrogenation in numerous experiments. Although great progress has been achieved in experiments, evaluation of the B-N bond cleavage channel as well as the hydrogen transfer channel has not been performed to gain a deep understanding of the kinetic route. Based on the density functional theory (DFT) calculation, we presented a clear mechanistic study on the hydrolytic reaction of AB by choosing the smallest NiCu cluster as a catalyst model. Two attacking types of water molecules were considered for the hydrolytic reaction of AB: stepwise and simultaneous adsorption on the catalyst. The Ni and Cu metal atoms play the distinctive roles in catalytic activity, i.e., Ni atom takes reactions for the H2O decomposition with the formation of [OH]- group whereas Cu atom takes reactions for the hydride transfer with the formation of metal-dihydride complex. The formation of Cu-dihydride and B-multihydroxy complex is the prerequisite for the effectively hydrolytic dehydrogenation of AB. By analyzing the maximum barrier height of the pathways which determines the kinetic rates, we found that the hydride hydrogen transferring rather than the N-B bond breaking is responsible to the experimentally measured activation energy barrier.

Long noncoding RNA LINC00511 promoted cell proliferation and invasion via regulating miR-124-3p/EZH2 pathway in gastric cancer.

OBJECTIVE: Growing evidence has shown that long non-coding RNAs (lncRNAs) can serve as prospective markers for survival in patients with gastric cancer (GC). In this study, we mainly focused on the potential roles of LINC00511 in the development process of GC. PATIENTS AND METHODS: RT-PCR was used to detect the expressions of LINC00511 and miR-124-3p in GC tumor tissues, adjacent tissues and GC cell lines. Furthermore, correlations between LINC00511 with miR-124-3p, and miR-124-3p with EZH2, were analyzed by Correlation analysis. Moreover, the overall survival (OS) of patients was analyzed using Kaplan-Meier method. Additionally, proliferation ability was measured by CCK-8 assay and invasion ability of GC cell line was detected by transwell assay. Besides, Western blot was performed to measure protein levels of GC tissues and GC cell lines. Finally, Dual-Luciferase reporter assay was performed to prove the potential binding sites between LINC00511 and miR-124-3p, miR-124-3p and EZH2. RESULTS: We found that LINC00511 was significantly increased in GC tissues and GC cell lines, which was associated with tumor growth, metastasis and predicted poor diagnosis of GC patients. MiR-124-3p was decreased in GC tissues and GC cell lines, which was negatively correlated with LINC00511 and EZH2. Furthermore, EZH2 was increased in GC tissues and GC cell lines, which was positively correlated with LINC00511. Moreover, LINC00511 inhibition repressed cell proliferation and invasion in MKN28 cells, the protein levels of Cyclin D1, ICAM-1, VCAM-1 and N-cadherin were repressed, while E-cadherin was increased. Besides, Luciferase gene reporter assay indicated that LINC00511 could sponge with miR-124-3p, which could directly target at EZH2, an oncogenic gene. We found that miR-124-3p/EZH2 axis regulated cell proliferation and invasion in MKN28 cells. Finally, the inhibited cell proliferation and invasion abilities were eliminated following with miR-124-3p inhibition in MKN28 cells with LINC00511 knockdown. CONCLUSIONS: According to the results, we found that LINC00511 was increased in GC tissues, which was associated with the poor OS in patients with GC. We uncovered a previously unappreciated LINC00511/miR-124-3p/EZH2 signaling axis in promoting cell proliferation and invasion in GC patients and GC cell lines, which suggested that it might be a potential target for treating human GC.

Effects of Mo contents on the microstructure, properties and cytocompatibility of the microwave sintered porous Ti-Mo alloys.

The porous Ti-Mo alloys were prepared by microwave sintering, and the effects of Mo contents on the pore structure, phase composition, compressive strength, elastic modulus, bending strength, corrosion resistance and cytocompatibility of porous Ti-Mo alloys were investigated. The results show that the porous Ti-Mo alloys are composed of α phase and ß phase, and the volume fraction of ß phase increases with increasing the Mo contents. The amount of Kirkendall pores distributed over the porous Ti-Mo alloys skeleton increases with increasing the Mo contents, which greatly increases the porosities and pore sizes of the porous Ti-Mo alloys. Correspondingly, all of the compressive strength, elastic modulus and bending strength of the porous Ti-Mo alloys decrease with increasing the Mo contents. The porous Ti-Mo alloys present excellent corrosion resistance in the Hank's solution due to the oxidation film of TiO2, MoO2 and MoO3 naturally formed on the surface, and the Mo contents have no obvious effect on the corrosion resistance. The cell viabilities of the porous Ti-Mo alloys are higher than 94%, indicating the porous Ti-Mo alloys possess favorable cytocompatibility. Moreover, the porous Ti-Mo alloys are beneficial to the spread, proliferation and differentiation of osteoblast-like cells, and the Mo contents have no significant effect on the cytocompatibility of the porous Ti-Mo alloys.

An amperometric biosensor based on hemoglobin immobilized in poly(epsilon-caprolactone) film and its application.

In this study, poly(epsilon-caprolactone) (PCL) was synthesized using the epsilon-caprolactone (CL) monomer ring-opening polymerization. We demonstrated that the hemoglobin (Hb) entrapped in PCL film could retain its original conformation by FT-IR spectra. A pair of well-defined redox peaks with a formal potential (E0') of about -0.38V (vs. SCE) in a pH 7.0 phosphate buffer solution was obtained at the Hb-PCL film modified GC electrode. The dependence of E(0') on the pH of the buffer solution indicated that the conversion of heme Fe(III)/Fe(II) was a reaction of one electron coupled to one proton. The apparent heterogeneous electron transfer rate constants (ks) of Hb confined to PCL was valuated as (18.7+/-0.8)s(-1) according to Laviron's equation. The surface concentration (Gamma*) of the electroactive Hb in the PCL film was estimated to be (7.27+/-0.57)x10(-11)molcm(-2). The Hb-PCL film modified electrode was shown to be an excellent amperometric sensor for the detection of hydrogen peroxide. The linear range is from 2 to 30microM with a detection limit of 6.07x10(-6)M. The sensor was effectively testified by the determination of the hydrogen peroxide in eyedrops as real samples.

The electrochemical behavior and surface analysis of Ti50Ni47.2Co2.8 alloy for orthodontic use.

OBJECTIVES: The aim of this study was to investigate the electrochemical behavior of Ti50Ni47.2Co2.8 alloy in deaerated artificial saliva solutions with binary NiTi alloy as reference and to characterize the composition and structure of the passive film after polarization tests. METHODS: The corrosion behavior of NiTiCo alloy was systematically studied by open circuit potential, potentiodynamic and potentiostatic techniques. The surface characterization after anodic polarization tests were demonstrated by XPS. The electrolytes were maintained at 37 degrees C by immersing the test cell in water bath. 500 mV vs. SCE was applied on the samples for potentiostatic tests. The metal ions concentration was measured by ICP/OES. RESULTS: Potentiodynamic and potentiostatic tests results showed that the corrosion behavior of NiTiCo was similar to that of NiTi alloy. With the increase of pH value of the electrolytes, both corrosion potential (Ecorr) and pitting corrosion potential (Eb) decreased. XPS results revealed that the outmost passive film consisted mainly of TiO2 which were identical with that of NiTi alloy. The Ni ion release amount of NiTiCo was very close to that of NiTi alloy as examined by ICP/OES. Neither Ti nor Co ion was detected due to the detection limitation. SIGNIFICANCE: The corresponding relationship between corrosion behavior and pH value of the artificial saliva should be taken into consideration during the application of orthodontic wires. The addition of Co had little effect on the corrosion behavior of NiTi as well as the formation of the passive film.