Ultrathin W-Al dual interlayer approach to depositing smooth and adherent nanocrystalline diamond films on stainless steel

The adherence of diamond coated on steel is commonly low and needs to be strengthened with thick intermediate layers. In this paper, a nanoscale W-Al dual metal interlayer has been applied on SS304 substrates to facilitate deposition of continuous, adherent and smooth diamond thin films. During the microwave plasma-enhanced chemical vapor deposition process, the Al inner layer 30 nm thick diffuses into steel surface inhibiting carbon diffusion and graphitization. The W outer layer 20 nm thick is transformed into W carbides, both preventing carbon diffusion and enhancing diamond nucleation. The diamond films synthesized are of high purity and have smooth surfaces and dense structures. Indentation and shear deformation tests indicate high delaminating tolerance of the diamond films.

Aflatoxin-albumin adducts and correlation with decreased serum levels of vitamins A and E in an adult Ghanaian population

A study of aflatoxin (AF) exposure and the levels of vitamins A and E was carried out with a group of 507 Ghanaian participants. AFB(1)-albumin adducts (AFB-AA) were measured by radioimmunoassay and vitamins A and E were measured by high-performance liquid chromatography (HPLC). The average level of serum AFB-AA was 0.94 +/- 0.64 (range = 0.1-4.44) pmol mg(-1) albumin. Mean levels of vitamins A and E were 1.32 +/- 0.48 (range = 0.41-4.85) micromol l(-1) and 15.68 +/- 4.12 (range = 6.35-30.40) micromol l(-1), respectively. A significantly negative correlation was found between serum AFB-AA and vitamin A levels (r = -0.110, p = 0.013). An even stronger, significant negative, correlation was found between serum AFB-AA and vitamin E levels (r = -0.149, p < 0.001). Serum AFB-AA levels were statistically higher (median = 0.985 pmol mg(-1) albumin) in subjects who had low levels of both vitamins A and E as compared with the levels (median = 0.741 pmol mg(-1) albumin) subjects who had high vitamins A and E levels (p(trend) = 0.001). To verify these findings, blood samples were again collected from 165 of the 507 people 3 months after the initial collection. Significantly negative correlations were confirmed between levels of serum AFB-AA and both vitamins A (r = -0.232, p = 0.003) and E (r = -0.178, p = 0.023). Again, high serum AFB-AA concentrations (median = 1.578 pmol mg(-1) albumin) were found in subjects with low levels of vitamins A and E compared with the concentrations (median = 1.381 pmol mg(-1) albumin) in subjects with high levels of vitamins A and E (p(trend) = 0.002). These data show that AF exposure was associated with decreased levels of serum vitamins A and E in high-risk human populations, which may significantly influence the incidence of AF-related adverse health effects.

Oxidative Stress and Apoptosis of Human Brain Microvascular Endothelial Cells Induced by Free Fatty Acids

Damage to endothelial cells is a key event in the pathogenesis of atherosclerosis and vascular disease. This study aimed to determine whether free fatty acids (FFAs) induced oxidative stress and apoptosis in human brain microvascular endothelial cells (HBMVECs) in vitro and, if so, which signalling pathway mediated these effects. After culture in different concentrations of FFAs for 24-72 h, cell viability/proliferation was determined using a cell counting kit, apoptosis was detected by measuring caspase-3 activity and by using annexin V-conjugated fluorescein isothiocyanate/propidium iodide staining, and oxidative stress was evaluated by measuring the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP). The HBMVECs exposed to FFAs showed significantly decreased cell proliferation, increased apoptosis and ROS levels, and decreased MMP. In conclusion, the results showed that high levels of FFAs induced oxidative stress, which damaged HBMVECs and resulted in apoptosis.

Role of hypoxia-inducible factor-1 alpha in the regulation of plasminogen activator activity in rat knee joint chondrocytes

OBJECTIVE

To examine the effects of hypoxia-inducible factor-1alpha (HIF-1alpha) on the plasminogen activator's (PA) activity and on the expression of components of PA system in articular chondrocytes of rats.

METHODS

Chondrocytes from rat knee joint cartilage were cultured under normoxic, hypoxic, CoCl(2) simulated hypoxic, and interleukin-1beta (IL-1beta)-stimulated conditions. siRNA targeting HIF-1alpha was transfected into cells cultured under hypoxic, simulated hypoxic, and IL-1beta-stimulated conditions to silence HIF-1alpha. PA activity was determined by the hydrolysis of the chromogenic substrate H-D-Val-Leu-Lys-pNA (S-2251). The mRNA levels were measured by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). The intracellular/matrix-associate protein levels were detected by Western blot and the soluble protein levels were measured by enzyme linked immunosorbent assay (ELISA). Chromatin immunoprecipitation (CHIP) assay was performed to determine whether HIF-1alpha binds to the hypoxia response element (HRE) of target genes.

RESULTS

The enhancement of HIF-1alpha by CoCl(2) resulted in a decrease of PA activity, and the silence of HIF-1alpha by siRNA led to an increase of PA activity. The PA inhibitor-1 (PAI-1) mRNA and protein were increased by hypoxia or simulated hypoxia, which was reversed by the siRNA2-mediated silencing of HIF-1alpha. CHIP assay further confirmed that the induction of PAI-1 involved the binding of HIF-1alpha to the PAI-1 promoter, while the enhancement or silencing of HIF-1alpha did not affect the expression of urokinase type PA (uPA), tissue type PA (tPA) or uPA receptor (uPAR). Additionally, IL-1beta stimulated both HIF-1alpha and PAI-1 in articular chondrocytes, and the IL-1beta-mediated induction of PAI-1 was inhibited partly by HIF-1alpha silencing.

CONCLUSION

HIF-1alpha may inhibit the PA activity through stimulating the expression of PAI-1 in normal articular chondrocytes. The inhibition of HIF-1alpha in the PA activity of articular chondrocytes probably plays an important role in the maintenance of articular cartilage matrix.

Feasibility of focused ultrasound therapy for recurrent cervicitis with high-risk human papillomavirus infection

OBJECTIVE

To investigate the feasibility of focused ultrasound therapy for recurrent cervicitis with high-risk human papillomavirus (HR-HPV) infection.

METHODS

This was a prospective clinical study, in which 20 patients with HR-HPV-positive recurrent cervicitis were enrolled. Focused ultrasound therapy was performed by one gynecologist. All patients were followed up for 6 months after ultrasound therapy. Telephone interviews, colposcopic examinations and Hybrid Capture II tests were performed to assess the safety and effectiveness of focused ultrasound therapy for HR-HPV-positive cervicitis.

RESULTS

Ultrasound therapy was tolerated well, and no severe complications were observed in any patient. Vaginal discharge was found intermittently in 95% of patients. Without any intervention this disappeared 1 month after ultrasound therapy. Patients' symptoms were relieved significantly by ultrasound therapy, including 88.9% patients who had abundant leukorrhea, 80% who had pelvic pain and 87.5% who had postcoital bleeding. No colposcopic evidence of cervicitis remained postoperatively in 75% of patients, and cytological examination showed that the lesions had disappeared in 80% of patients. Follow-up HPV testing revealed that 75% of patients presented negative HR-HPV infection following treatment.

CONCLUSIONS

Focused ultrasound therapy is feasible and effective in the treatment of patients with HR-HPV-positive cervicitis. It may provide a useful non-invasive treatment for recurrent cervicitis with HR-HPV infection.

Vector vaccination and vector targeted chemotherapy in solid tumors

Gene therapy is one of the promising treatment modalities in cancer therapy. The current gene therapy modalities are mainly focused on the introduction of suppressed tumor suppressor genes into cancer cells, modulation of anti-tumoral immune response, and the suicide gene therapy by introducing pro-drug-activating enzyme genes into the tumor cells. Currently, various gene therapy trials are being conducted in cancer patients. However, the early results of these trials conducted so far are not so encouraging. Combination of gene therapy strategies with conventional treatment modalities such as chemotherapy, immunotherapy or radiotherapy has yielded encouraging results in experimental models and early clinical trials.

Vector prime protein boost vaccination in the setting of myeloablative-induced lymphopenia suppresses growth of leukemia and solid tumors

We have developed a vaccine, which is designed to induce tumor-associated antigen (TAA)-specific T cells and antibodies in the setting of profound lymphopenia induced by myeloablative therapy and T-cell-depleted bone marrow transplantation. Test mice were injected subcutaneously (sc) with the 32DP210Bcr-Abl cell line, which is positive for the p210Bcr-Abl protein (Group 1). In Group 2, 7 days after injection of the 32DP210Bcr-Abl positive cell line, the mice received 900 cGy total body irradiation (TBI) followed in 1 h by the intravenous infusion of 10 million T-cell-depleted syngeneic bone marrow cells (TCDBMT) (Group 2). The leukemia-bearing group received an intravenous injection of 10 million spleen cells (donor lymphocyte infusions) from unvaccinated (Group 3) and TAA/ecdCD40L-vaccinated (Group 4) syngeneic mice 3 days after completion of the TBI and TCDBMT. Groups 3 and 4 mice received three additional sc vaccinations at 7-day intervals with the TAA/ecdCD40L vaccine, in which the TAA was taken from the junctional peptide of the P210bcr-Abl protein. The survival of Groups 3 and 4 mice was significantly longer than that in Groups 1 and 2 mice. Vaccinated mice from Group 4, which developed complete responses, survived up to 350 days post-injection of the leukemia cells without any evidence of leukemia regrowth.

Effect of GM-CSF on tumor-specific immune response and antitumoral efficacy when combined with suicide gene therapy

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Background: Suicide gene therapy is one of the promising treatment modalities in cancer treatment. Combination of an immunotherapy modality with suicide gene therapy would increase the tumor eradciating efficacy of either treatment strategy used alone. Methods: In the current study, we constructed adenoviral vectors carying ytosine deaminase (CD), granulocyte macrophage-colony stimulating factor (GM-CSF) vectors. We tested the in vitro efficacy of the vectors in both human and mouse tumor cell lines and in a syngeneic mouse model of colon cancer with tumor explants of CRL 2638 cells. Results: Our results show that the vectors carrying CD/GM-CSF transcription units are effective in terms of killing of tumor cells when 5-FC added. Addition of GM-CSF transgene induced a significant amount of GM-CSF secretion (250 pg/ml/105 cells) of infected cells. In the syngeneic colon cancer model, addition of GM-CSF significantly increased tumor-specific cellular immune response when compared to suicide gene therapy alone. (p<0.01). Likewise, GM-CSF addition caused a 8 times reduction in the ratio of Tregs infiltrating the tumor nodules (p<0.001). Accordingly, GM-CSF decreased the tumor growth by 2 times an d increased the median survival time by 50% (p<0.01). Conclusions: These impressive results of in-vitro cytotoxicity and encouraging results of in-vivo testing of the our newly constructed GM-CSF carrying vector suggest a potential for the use of the vector for the treament of established tumors by inducing tumor specific immune response.

No significant financial relationships to disclose.

Petrochemical wastewater odor treatment by biofiltration

The treatment of odorous pollutants by microorganisms on packed waste straw and cortex was investigated at the wastewater treatment plant of the Shanghai petrochemical factory. The removal efficiency of H(2)S, NH(3) and VOCs (volatile organic compounds) reached 98%, 91% and 90%, respectively after operation for one month at an empty bed retention time (EBRT) of 120s. The heterotrophic bacteria were found to be the dominant microorganism in the biofilter, while fungi and actinomycetes were also present. The bacteria were mostly identified as the members of the genus Bacillus (62.5% of cultured bacteria). The single strand conformation polymorphism (SSCP) results revealed that the genus Bacillus and Pseudomonas were the predominant bacteria. The microbial diversity gradually increased as the treatment progressed, which indicated that the microbial community in the biofilter became more stable upon pollutant removal. The scanning electron microscopy (SEM) was performed to evaluate the microorganism growth on the media. It was found that the waste straw and cortex were suitable for microorganism attachment and growth, and may have potential application in odor treatment.

The controlled synthesis of single-crystalline CdCO3 nanoparticles with different morphologies

Single crystalline CdCO3 low-dimensional nanostructures, such as nanowires, nanobelts, and nanorolls have been controlled synthesized through a convenient, low-temperature hydrothermal method. Moreover, the shape and diameter of low-dimensional CdCO3 nanostructures can be facilely controlled through adjusting the experiment factors. The influences of the ammonia concentration and temperature on the morphology of CdCO3 are investigated, and a possible mechanism involved adjustable growth properties from kinetic growth stage to thermodynamic growth stage has been discussed. This work has also provided a general, simple, and effective method to control the shape of other transition-metal carbonate.