Controllable two-scale network architecture and enhanced mechanical properties of (Ti5Si3+TiBw)/Ti6Al4V composites

Novel Ti6Al4V alloy matrix composites with a controllable two-scale network architecture were successfully fabricated by reaction hot pressing (RHP). TiB whiskers (TiBw) were in-situ synthesized around the Ti6Al4V matrix particles, and formed the first-scale network structure (FSNS). Ti₅Si₃ needles (Ti₅Si₃) precipitated in the β phase around the equiaxed α phase, and formed the secondary-scale network structure (SSNS). This resulted in increased deformation compatibility accompanied with enhanced mechanical properties. Apart from the reinforcement distribution and the volume fraction, the ratio between Ti₅Si₃ and TiBw fraction were controlled. The prepared (Ti₅Si₃ + TiBw)/Ti6Al4V composites showed higher tensile strength and ductility than the composites with a one-scale microstructure, and superior wear resistance over the Ti6Al4V alloy under dry sliding wear conditions at room temperature.

The 341C/T polymorphism in the GSTP1 gene and lung cancer risk: a meta-analysis

Numerous studies have evaluated the association between the 341C/T polymorphism in glutathione S-transferase P1 (GSTP1) and lung cancer risk. However, there are conflicting results from previous studies. To derive a more precise estimation of the association, we conducted this meta-analysis. A comprehensive search was conducted to identify the eligible studies examining the GSTP1 341C/T polymorphism and lung cancer risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. The meta-analysis results showed that the GSTP1 341C/T polymorphism was significantly associated with lung cancer risk (TT vs CC: OR = 3.33, 95%CI = 1.49-7.44; CT vs CC: OR = 1.35, 95%CI = 1.10-1.65; dominant model: OR = 1.43, 95%CI = 1.05-1.96; recessive model: OR = 0.31, 95%CI = 0.14-0.70). The results indicate that the GSTP1 341C/T polymorphism may contribute to lung cancer risk. Conclusive evidence on the effects of this variant in lung cancer should be addressed in further studies.

[Preliminary study for the roles and mechanisms of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles in the Lewis lung cancer mice]

OBJECTIVE

To comparatively observe the effects of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles on the Lewis lung cancer mice and to explore the mechanisms of Rg3 and PEG-PLGA-Rg3 nanoparticle anti-cancer in vivo.

METHODS

Lewis lung cancer mouse model was established and 60 mice were randomly divided into 5 groups with twelve in each group: PEG-PLGA-Rg3 nanoparticles group(Rg3-N), PEG-PLGA group (PEG), Rg3 group (Rg3), normal control group(C), saline control group(NS), and received intragastric administration for 14 days. The weights of the mice were measured every 2 days and the weight curves were obtained. At the same time, the color pattern, activity and mental status were observed. The mice were sacrificed when the administration was over, and the effects of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles on tumor weight, and the tumor:weight ratios were analysed. In addition, the tumor microvessel density (MVD) was measured by immunohistochemical staining with anti-CD31 antibody to compare the effects of Rg3 and PEG-PLGA-Rg3 nanoparticles on the tumor angiogenesis in vivo. Furthermore, the levels of such angiogenesis and proliferation factors as MMP-9, HIF-1α, VEGF, Ki-67 were examined by RT-PCR, Western blot and immunohistochemistry to explore the internal molecular mechanisms of anti-tumor effects in vivo.

RESULTS

The trends of variation of the mice weights in NS group and PEG group were rising early but declining later. In contrast, the trends of the other three groups were rising early and became stable later. In comparison with NS group, the mice of Rg3 group and Rg3-N group had better general status: brighter color, more active and better spirit. Compared with NS group,the tumor weight in PEG group, Rg3 group and Rg3-N group showed no significant difference but the tumor:weight ratio and MVD in Rg3 group and Rg3-N group declined significantly (P<0.01). Besides, there was no significant difference between Rg3 group and Rg3-N group. At the same time, the level of VEGF mRNA, the protein expression of MMP-9, HIF-1α, VEGF in Rg3 group and Rg3-N group decreased compared with NS group. Furthermore, the level of each index above-mentioned in Rg3-N group was lower than that in Rg3 group. The expression of Ki-67 in PEG group, Rg3 group and Rg3-N group showed no significant difference compared with NS group.

CONCLUSION

Rg3 and PEG-PLGA-Rg3 nanoparticle may suppress the expression of VEGF, MMP-9 and HIF-1α in Lewis lung cancer mice, thereby indirectly contributing to their antitumor effects and alleviating the mice's general status. In addition, PEG-PLGA nanoparticles embedding can promote Rg3 antitumor effect in vivo.

Dynamic heterogeneity and non-Gaussian statistics for acetylcholine receptors on live cell membrane

The Brownian motion of molecules at thermal equilibrium usually has a finite correlation time and will eventually be randomized after a long delay time, so that their displacement follows the Gaussian statistics. This is true even when the molecules have experienced a complex environment with a finite correlation time. Here, we report that the lateral motion of the acetylcholine receptors on live muscle cell membranes does not follow the Gaussian statistics for normal Brownian diffusion. From a careful analysis of a large volume of the protein trajectories obtained over a wide range of sampling rates and long durations, we find that the normalized histogram of the protein displacements shows an exponential tail, which is robust and universal for cells under different conditions. The experiment indicates that the observed non-Gaussian statistics and dynamic heterogeneity are inherently linked to the slow-active remodelling of the underlying cortical actin network.

WITHDRAWN: Natural Killer Cell Activating Receptor NKG2D Is Involved in the Immunosuppressant Effect of Mycophenolate Mofetil and Infection of Hepatitis B Virus

In this study we investigated whether mycophenolate mofetil (MMF), a new immunosuppressant, and its metabolite mycophenolic acid (MPA) influence the activity of liver resident natural killer (NK) cells, resulting in increased susceptibility to hepatitis B virus (HBV) infection. We isolated the hepatic NK cells of C57BL/6 and C57BL/6JTgN (A1b1HBV) 44Bri) transgenic mice administered MMF in the presence or absence of interleukin (IL)-15, or incubated isolated hepatic NK cells in the presence or absence of MPA and used RT-PCR, immunolabeling to assess the expression of NK receptors Ly49A, NKG2A and NKG2D, and cytokine ELISA and [(3)H]-TdR-release assay to assess the activation and cytotoxic capacity of NK cells. After treatment of MMF in the presence or absence of IL-15, HBsAg titer was also measured in C57BL/6JTgN (A1b1HBV) 44Bri) transgenic mice. After both MPA and MMF treatments, NK cytotoxicity was reduced, NKG2D and Ly49A expression was down-regulated, but NKG2A was up-regulated. Down-regulation of NKG2D could be ameliorated by IL-15, and in HBV-transgenic mice, MMF treatment impaired NK cell activity, but did not influence virus replication, whereas IL-15 treatment depressed HBsAg titer. MPA and MMF mediate down-regulation of NKG2D in vitro and vivo, restricting the cytotoxic capacity of NK cells. Regulation of NKG2D may be important in the effect of immunosuppressant on NK cell activity and involved in HBV infection.

A long non-coding RNA interacts with Gfra1 and maintains survival of mouse spermatogonial stem cells

Spermatogonial stem cells (SSCs) are unique male germline stem cells that support spermatogenesis and male fertility. Long non-coding RNAs (lncRNA) have been identified as key regulators of stem cell fate; however, their role in SSCs has not been explored. Here, we report that a novel spermatogonia-specific lncRNA (lncRNA033862) is essential for the survival of murine SSCs. LncRNA033862 is expressed in early spermatogonia including SSC and was among 805 lncRNAs identified by global expression profiling as responsive to glial cell-derived neurotrophic factor (GDNF), a growth factor required for SSC self-renewal and survival. LncRNA033862 is an antisense transcript of the GDNF receptor alpha1 (Gfra1) that lacks protein coding potential and regulates Gfra1 expression levels by interacting with Gfra1 chromatin. Importantly, lncRNA033862 knockdown severely impairs SSC survival and their capacity to repopulate recipient testes in a transplantation assay. Collectively, our data provide the first evidence that long non-coding RNAs (lncRNAs) regulate SSC fate.

HPV16 E6 mutations and p53 codon72 polymorphism among women with cervical intraepithelial neoplasia 2 and 3 in China

OBJECTIVE

To study the distribution of HPV16 E6 gene mutations and p53 codon72 polymorphism among women with HPV16+ cervical precancerous lesions and explore their relationship with the risk of cervical intraepithelial neoplasia (CIN) 2, 3. Materials and Meth- ods: This study analyzed a total of 112 cases of exfoliated HPV16+ cervical cell specimens which were divided into group I (normal and CIN1, 55 cases) and group2 (CIN2, 3, 57 cases). Among the 112 specimens, 85 cases were successfully amplified for HPV E6 gene by PCR and the PCR products were sequenced directly. P53 codon72 region was also amplified from the 112 specimens and the PCR products were sequenced directly and compared with the standard sequence.

RESULTS

Among the 85 amplified HPV sequences, point mutations such as T178G, T350G, G132A, A442C, T310G, G94T, C551A, etc. were found, among which, T178G showed the highest rate (51.76%). The rate of HPV16 E6 mutation T178G in CIN2, 3 group was significantly higher than that in normal and CINI group, i.e., in the 112 amplified p53 codon72 sequences, the distribution of Pro/Pro genotype in normal, and CIN1 group was significantly different from that in CIN2, 3 groups, and the disease risk of Pro/Pro genotype was much higher than that of Arg/Arg and Arg/Pro genotypes.

CONCLUSION

HPV16 E6 T178G mutation increases the disease risk of CIN2, 3. Meanwhile, compared with Arg/Arg and Arg/Pro genotypes, p53 codon72 Pro/Pro genotype more associated with the disease risk of CIN2, 3.

A myeloablative conditioning regimen with fludarabine demonstrates good results in UCBT for 30 pediatric patients with hematologic malignancies, especially acute lymphoblastic leukemia

We retrospectively analyzed the safety and efficacy of a myeloablative conditioning regimen with fludarabine (FLU) in unrelated cord blood transplantation (UCBT) of 30 pediatric patients with hematologic malignancies. The conditioning regimen consisted of FLU, busulfan (BU) and cyclophosphamide (CY). All of the patients received Cyclosporine (CSA) and mycophenolate mofetil (MMF) as graft versus host disease (GVHD) prophylaxis. We achieved high engraftment rates (96.7%) and rapid hematopoietic reconstitution. Acute GVHD occurred in 12 cases of the 29 engraftment patients (41.4%), and 6 cases (20.7%) were of grade III-IV. Chronic GVHD only occurred in 1 of 28 evaluable patients (3.6%). Twenty-three patients (76.7%) became infected, and 3 cases (10.0%) died of severe infections. Cytomegalovirus (CMV) reactivation occurred in 70.0% of the patients, but no CMV diseases were observed, nor did any patients die of CMV infection. The cumulative incidence of relapse (6.7%) was significantly reduced, and none of the acute lymphoblastic leukemia (ALL) patients relapsed. The 3-year overall survival (OS) and event-free survival (EFS) rates were 73.3% and 70.0%, respectively. The 3-year OS and EFS of the ALL patients was 75.0%. This conditioning regimen demonstrates good results and security in UCBT, especially in acute lymphoblastic leukemia.

Association of ApaI and BsmI polymorphisms with vitiligo risk: a meta-analysis

BACKGROUND

It has been reported that polymorphisms of the vitamin D receptor gene (VDR) such as ApaI or BsmI may affect the risk of vitiligo. However, the results have been inconsistent.

AIM

To evaluate the association between two common polymorphisms (ApaI and BsmI) in the VDR gene and the susceptibility to vitiligo.

METHODS

The PubMed, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched, and OR with 95% CI was calculated. The strength of association and vitiligo risk was assessed under five genetic models: allele, dominant, recessive, homozygous and heterozygous.

RESULTS

Six relevant studies were identified, including five studies that assessed the ApaI polymorphism and four the BsmI polymorphism (some overlapped). The meta-analysis results indicated that either the ApaI or the BsmI gene polymorphism may increase the risk of vitiligo in East Asian populations (aa + Aa vs. AA: OR = 1.40, 95% CI 1.01-1.96, P < 0.05; bb vs. Bb + BB: OR = 1.32, 95% CI 1.09-1.59, P < 0.01). No publication bias was detected in this meta-analysis.

CONCLUSION

The current meta-analysis suggests that the ApaI a allele or BsmI bb genotype are associated with the risk of vitiligo in East Asian populations. Thus, these polymorphisms could be potential biomarkers for early detection of vitiligo.

Early third trimester maternal response to glucose challenge and pregnancy outcome in Chinese women-relationship between upper distribution level and recommended diagnostic criteria

BACKGROUND/OBJECTIVES

The objective of this study was to examine the relationship between upper distribution levels of glucose values in the 75-g oral glucose tolerance test (OGTT) and recommended diagnostic criteria for gestational diabetes mellitus (GDM) and adverse pregnancy outcomes.

SUBJECTS/METHODS

The distribution of the OGTT 2-h values of 13,501 pregnant women, which were below the World Health Organization (WHO) threshold for overt diabetes mellitus (DM), and managed in one teaching hospital in China, was reviewed and related to maternal characteristics and pregnancy outcomes.

RESULTS

For the entire group, the 90th and 95th percentile values of the OGTT 2-h glucose level, respectively, were close to the diagnostic cutoff values of the WHO and International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. For adverse maternal outcomes, glucose level above the 90th percentile value was associated with increased hypertensive disorders, whereas no difference was seen with cutoff using the 95th percentile value. For perinatal outcomes, the 90th percentile was associated with increased neonatal intensive care unit admission and hypoglycemia, whereas the 95th percentile showed in addition association with phototherapy for jaundice and 5th-minute Apgar score <7. Although no differences in the incidence of adverse pregnancy outcomes were found using the different cutoffs, the >95th percentile cutoff value would have missed out 33.3-56.7% of the cases of adverse outcomes that would otherwise have been attributed to GDM.

CONCLUSIONS

Further studies are warranted to clarify which diagnostic criterion is most appropriate universally to identify adverse pregnancy outcomes attributed to GDM, and which could be mitigated with treatment specific for GDM.

A novel approach to accelerate the reaction between Ti and Al

Pure Ti foils and SiCp/Al composite foils were employed to investigate the parabolic growth kinetics of TiAl3 at 660°C. Compared with pure Al foils, the introduction of SiC particles significantly refined TiAl3 grain size by the solid solution of silicon. Corresponding refinement mechanisms were concluded from the perspective of the nucleation of TiAl3. Micromechanics analysis shows that the fine TiAl3 grains own a small viscous resistance, and subsequently an improvement in the reaction rate could be achieved. This meaningful law also applies extensively to Ni/Al and Fe/Al systems.

Randomised controlled trial: sequential vs. standard triple therapy for Helicobacter pylori infection in Chinese children-a multicentre, open-labelled study

BACKGROUND

Studies have showed that 10-day sequential treatment regimen achieved higher Helicobacter pylori eradication rate than standard triple therapies.

AIM

To compare a 10-day sequential therapy and standard triple therapy in Chinese children with H. pylori infection.

METHODS

A prospective, multicentre, open-label, randomised controlled trial was conducted in four tertiary medical centres in China. Children with H. pylori gastritis were randomly assigned to a 10-day sequential therapy consisting of omeprazole and amoxicillin for 5 days followed by omeprazole, clarithromycin and metronidazole for the remaining 5 days, or 7-day or 10-day standard triple therapy comprising of omeprazole, amoxicillin and clarithromycin. H. pylori eradication was assessed by H. pylori stool antigen test.

RESULTS

A total of 360 patients were included. The eradication rate achieved with the 10-day sequential therapy was significantly higher than either the 7-day or 10-day standard triple treatment, either by the intention-to-treat analysis (81.4% vs. 61.9% or 67.7%, P < 0.05) or per-protocol analysis (89.7% vs. 70.8% or 77.8%, P < 0.05).

CONCLUSIONS

The 10-day sequential regimen was significantly more effective than standard 7-day or 10-day triple regimens in eradicating H. pylori infection in Chinese children.

Improving the corrosion resistance of Mg-4.0Zn-0.2Ca alloy by micro-arc oxidation

In this paper, corrosion resistance of the Mg-4.0Zn-0.2Ca alloy was modified by micro-arc oxidation (MAO) process. The microstructure and phase constituents of MAO layer were characterized by SEM, XRD and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of MAO treated Mg-4.0Zn-0.2Ca alloy in the simulated body fluid were characterized by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The microstructure results indicated that a kind of ceramic film was composed by MgO and MgF2 was formed on the surface of Mg-4.0Zn-0.2Ca alloy after MAO treatment. The electrochemical test reveals that the corrosion resistance of MAO treated samples increase 1 order of magnitude. The mechanical intensity test showed that the MAO treated samples has suitable mechanical properties.

Analysis of one year follow-up of women with cervical cytology report of atypical squamous cells and the diagnostic role of high-risk HPV infection

OBJECTIVE

To investigate the risk of developing cervical intraepithelial neoplasia grade 2 (CIN2) or greater disease in patients with cytology report of atypical squamous cells of undetermined significance (ASC-US) or cannot exclude high-grade atypical squamous cells (ASC-H) in one year follow-up.

STUDY DESIGN

Analysis of colposcopy-directed multiple cervical biopsies in all patients. Patients without CIN2 or greater diseases were tested for human papillomavirus (HPV) DNA at the enrollment and at 12th month and followed up by cytology at the 6th and 12th month. Patients with repeated abnormal results were subjected to colposcopy-directed biopsy.

RESULTS

A total of 894 ASC-US and 101 ASC-H patients were enrolled. The rate of CIN2 or greater disease was 14.2% in ASC-US group and 46.5% in ASC-H group, at the first test respectively. A total of 65.0% of patients in ASC-US have completed the study and 47.5% repeatedly showed abnormal cytology, while the same rates in ASC-H were 62.7% and 50%. Only four cases were diagnosed with CIN2 in ASC-US group. The rate of HPV DNA becoming negative was 54.9% and 51.5% for ASC-US and ASC-H, respectively.

CONCLUSIONS

The diagnosis rate of CIN2 or greater lesions in ASC-US and ASC-H patients was about 15% and 46.5%, respectively, within one year.

Correlation of cervical intraepithelial neoplasia with expressions of p16 and Ki67 in exfoliated cervical cells in fluid-based thin-layer samples

OBJECTIVE

To understand the correlation of cervical intraepithelial neoplasia (CIN) with the expressions of p16 and Ki67 in exfoliated cervical cells obtained by fluid-based thin-layer technology.

STUDY DESIGN

The distributions ofpl6 and Ki67 positive cells in 116 patients with cytologically diagnosed atypical squamous cells of undetermined significance (ASC-US) or human papilloma virus (HPV) positive were examined by immunocytochemistry. Data were analyzed by the rank sum test, crosstab test, and receiver operating characteristic (ROC) curves.

RESULTS

When the thresholds for p16 and Ki67 positive were set as 6.5 and 4.5 positive cells per 100 exfoliated cervical cells, respectively, the expressions of Ki67 and P16 are significantly higher in the exfoliated cervical cells of patients with CIN II or greater compared with those in patients with CIN I or less.

CONCLUSION

Immunocytochemical examination of p16 and Ki67 expressions in the exfoliated cervical cells of fluid-based thin-layer samples could be used for the detection of CIN II or greater.

Formation of intermetallic compound layer in multi-laminated Ni-(TiB2/Al) composite sheets during annealing treatment

Solid-state reactive diffusion between Ni and Al was investigated during annealing at 650°C by employing multi-laminated Ni-(TiB(2)/Al) composite sheets. In multi-laminated Ni-(TiB(2)/Al) composite sheets annealed up to 5min NiAl(3) was the only phase observed in the diffusion zone, and Ni(2)Al(3) appeared after longer annealing time. Most grains of Ni(2)Al(3) showed equiaxed morphology rather than columnar microstructures like NiAl(3), due to the low concentration gradients of Al and Ni at the Ni/NiAl(3) interface. The preferential formation of this intermetallic compound NiAl(3) in multi-laminated Ni-(TiB(2)/Al) composite sheets was predicted using an effective heat of formation model. The present work indicated that both Ni and Al interdiffused, and the formation of NiAl(3) was a reaction-diffusion process.