Optimisation of Reactive Black 5 dye removal by electrocoagulation process using response surface methodology

In this work, a regression model obtained from response surface methodology (RSM) was proposed for the electrocoagulation (EC) treatment of textile wastewater. The Reactive Black 5 dye (RB5) was used as a model dye to evaluate the performance of the model design. The effect of initial solution pH, applied current and treatment time on RB5 removal was investigated. The total number of experiments designed by RSM amounted to 27 runs, including three repeated experimental runs at the central point. The accuracy of the model was evaluated by the F-test, coefficient of determination (R²), adjusted R² and standard deviation. The optimum conditions for RB5 removal were as follows: initial pH of 6.63, current of 0.075 A, electrolyte dose of 0.11 g/L and EC time of 50.3 min. The predicted RB5 removal was 83.3% and the percentage error between experimental and predicted results was only 3-5%. The obtained data confirm that the proposed model can be used for accurate prediction of RB5 removal. The value of the zeta potential increased with treatment time, and the X-ray diffraction pattern shows that iron complexes were found in the sludge.

Safety and Efficacy of Ziagen (Abacavir Sulfate) in HIV-Infected Korean Patients

BACKGROUND

Abacavir is a widely-used nucleoside reverse transcriptase inhibitor for the treatment of human immunodeficiency virus (HIV) infection. Mandatory postmarketing surveillance was conducted in Korea to monitor the safety and evaluate the effectiveness of Ziagen® (abacavir sulfate 300 mg; ViiV Healthcare, Middlesex, UK).

MATERIALS AND METHODS

An open-label, multi-center, non-interventional postmarketing surveillance study was conducted from June 2010 to June 2016 to monitor the safety and effectiveness of Ziagen across 12 hospitals in Korea. Subjects older than 18 years taking Ziagen according to prescribing information were enrolled. The primary outcome was defined as the occurrence of any adverse events after Ziagen administration. Secondary outcomes included the occurrence of adverse drug reactions, occurrence of serious adverse events, and effectiveness of Ziagen administration.

RESULTS

A total of 669 patients were enrolled in this study, with a total observation period of 1047.8 person-years. Of these, 90.7% of patients were male. The mean age of patients was 45.8±11.9 years. One-hundred ninety-six (29.3%) patients reported 315 adverse events, and four patients reported seven serious adverse events, without any fatal events. There was one potential case of an abacavir hypersensitivity reaction. Among the 97 adverse drug reactions that were reported from 75 patients, the most frequent adverse drug reactions included diarrhea (12 events), dyspepsia (10 events), and rash (9 events). No ischemic heart disease was observed. In the effectiveness analysis, 91% of patients achieved HIV-1 RNA under 50 copies/mL after 24 months of observation with abacavir administration.

CONCLUSION

Our data showed the safety and effectiveness of Ziagen in a real-world setting. During the study period, Ziagen was well-tolerated, with one incident of a clinically suspected abacavir hypersensitivity reaction. The postmarketing surveillance of Ziagen did not highlight any new safety information. These data may be helpful in understanding abacavir and the HIV treatment practices in Korea.

Candidate Resonant Tetraneutron State Populated by the ^{4}He(^{8}He,^{8}Be) Reaction

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186  MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst)  MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.

CNS active target (CAT) for missing mass spectroscopy with intense beams

A new gaseous active target based on a time projection chamber, named CAT, is introduced. The remarkable feature is a dual gain THGEM to decrease the effective gain for the beam particles while keeping a high enough effective gain for the recoil particles. The measured effective gain of low gain region was a factor of one hundred smaller than that of high gain region. This technique provides a wide dynamic range in order to detect both the beam and recoil particles at the same time even with a very high intensity beam of more than 10⁵ Hz.

Gene of the month: PIK3CA

PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K) which through its role in the PI3K/Akt pathway is important for the regulation of important cellular functions such as proliferation, metabolism and protein synthesis, angiogenesis and apoptosis. Mutations in PIK3CA are known to be involved in a wide range of human cancers and mutant PIK3CA is thought to act as an oncogene. The specific PIK3CA inhibitor, NVP-BYL719, has displayed promising results in cancer therapy and is currently under clinical trials. Furthermore, PI3K regulates autophagy, a cellular process that recycles proteins and organelles through lysosomal degradation and has recently been recognised as an attractive therapeutic target due to its pro- and anti-cancer properties. Several studies have attempted to investigate the effects of combining the inhibition of both PI3K and autophagy in cancer therapy, and an in vivo model has demonstrated that the combined use of a concomitant PI3K and autophagy inhibitor induced apoptosis in glioma cells.

Enhanced performances in inverted small molecule solar cells by Ag nanoparticles

We demonstrate a highly efficient inverted small molecular solar cell with integration of Ag nanoparticles (NPs) into the devices. The optimized device based on thermal evaporated Ag NPs provides a power conversion efficiency (PCE) of 4.87%, which offers 33% improvement than that of the reference device without Ag NPs. Such a high efficiency is mainly attributed to the improved electrical properties by virtue of the modification of the surface of ITO with Ag NPs and the enhanced light harvesting due to localized surface plasmon resonance (LSPR). The more detail enhanced mechanism of the PCE by introduction of Ag NPs is also discussed.

Characteristics of invasive Staphylococcus aureus infections in three regions of Korea, 2009-2011: a multi-center cohort study

BACKGROUND

Despite the importance of invasive Staphylococcus aureus (ISA) infection, its overall burden in non-selected populations has only been defined in a small number of studies in Europe and North America. To define the characteristics of ISA infections in Korea, we conducted a multi-center cohort study to estimate population-based incidence rates.

METHODS

We conducted a multicenter prospective cohort study at nine university-affiliated active-surveillance core centers (ASCs) in three regions of Korea. To cover all available clinical microbiologic laboratories, we classified the laboratories in these regions into three groups according to their clinical environment as: 1) Nine ASCs, 2) Five major commercial laboratories and 3) Forty-four acute-care hospital-affiliated microbiology laboratories. We requested all the laboratories to report prospectively their numbers of cases of S. aureus isolated from normally sterile sites. Detailed clinical information was collected about the cases in the nine ASCs.

RESULTS

From 1 July 2009 to 30 June 2011, a total of 1,198 cases of ISA infection were identified at the nine ASCs, including 748 (62%) methicillin-resistant S. aureus (MRSA) infections. Most (81%) ISA infections were healthcare-associated (HCA): 653 (55%) hospital-onset and 322 (27%) community-onset. 223 (19%) were community-associated infections. The most common primary diagnosis was catheter-associated infection (225 cases, 19%). Respiratory tract infection (160, 13%), skin & soft tissue (152, 13%) and bone & joint infections (120, 10%) were also common. 30-day and 12-week mortality rates were 25.6% (262/1,024) and 36.5% (314/860), respectively. Complications, including metastatic infection within 12 weeks, occurred in 17.8% of ISA infections. The most common site of metastatic infection was the lung (9.8%, 84/860). Based on the total of 2,806 observed cases of ISA infection, estimated annual rates of ISA and invasive MRSA infections were 43.3 and 27.7 per 100,000 populations, respectively.

CONCLUSIONS

Our data provide important information about the clinical characteristics of ISA infections. We estimate that over 21,000 ISA infections and 13,000 invasive MRSA infections occurred in Korea in 2010.

PTRF/cavin-1 neutralizes non-caveolar caveolin-1 microdomains in prostate cancer

Caveolin-1 has a complex role in prostate cancer and has been suggested to be a potential biomarker and therapeutic target. As mature caveolin-1 resides in caveolae, invaginated lipid raft domains at the plasma membrane, caveolae have been suggested as a tumor-promoting signaling platform in prostate cancer. However, caveola formation requires both caveolin-1 and cavin-1 (also known as PTRF; polymerase I and transcript release factor). Here, we examined the expression of cavin-1 in prostate epithelia and stroma using tissue microarray including normal, non-malignant and malignant prostate tissues. We found that caveolin-1 was induced without the presence of cavin-1 in advanced prostate carcinoma, an expression pattern mirrored in the PC-3 cell line. In contrast, normal prostate epithelia expressed neither caveolin-1 nor cavin-1, while prostate stroma highly expressed both caveolin-1 and cavin-1. Utilizing PC-3 cells as a suitable model for caveolin-1-positive advanced prostate cancer, we found that cavin-1 expression in PC-3 cells inhibits anchorage-independent growth, and reduces in vivo tumor growth and metastasis in an orthotopic prostate cancer xenograft mouse model. The expression of α-smooth muscle actin in stroma along with interleukin-6 (IL-6) in cancer cells was also decreased in tumors of mice bearing PC-3-cavin-1 tumor cells. To determine whether cavin-1 acts by neutralizing caveolin-1, we expressed cavin-1 in caveolin-1-negative prostate cancer LNCaP and 22Rv1 cells. Caveolin-1 but not cavin-1 expression increased anchorage-independent growth in LNCaP and 22Rv1 cells. Cavin-1 co-expression reversed caveolin-1 effects in caveolin-1-positive LNCaP cells. Taken together, these results suggest that caveolin-1 in advanced prostate cancer is present outside of caveolae, because of the lack of cavin-1 expression. Cavin-1 expression attenuates the effects of non-caveolar caveolin-1 microdomains partly via reduced IL-6 microenvironmental function. With circulating caveolin-1 as a potential biomarker for advanced prostate cancer, identification of the molecular pathways affected by cavin-1 could provide novel therapeutic targets.

High-resolution capillary isoelectric focusing-electrospray ionization mass spectrometry for hemoglobin variants analysis

On-line capillary isoelectric focusing (CIEF)-electrospray ionization mass spectrometry (ESIMS) as a two-dimensional separation system is employed for high-resolution analysis of hemoglobin variants A, C, S, and F. The effects of moving ionic boundary inside the CIEF capillary and MS scan rate on the separation resolution and mass detection of hemoglobin variants are investigated. The formation of a moving ionic boundary due to the replacement of background electrolyte counterions with sheath liquid counterions can be minimized by combining cathodic mobilization with a gravity-induced hydrodynamic flow. Hemoglobin variants F and A, with a pI difference of 0.05 pH unit, are almost baseline resolved and identified in CIEF-ESIMS. The concentration detection limit for each hemoglobin variant is in the range of 10(-)(8) M, comparable to that obtained in two-dimensional gel electrophoresis using silver staining. Initial preconcentration during the focusing step and the use of single-ion monitoring scan mode are responsible for improving detection limits.

Identification of factors that function in Drosophila salivary gland cell death during development using proteomics

Proteasome inhibitors induce cell death and are used in cancer therapy, but little is known about the relationship between proteasome impairment and cell death under normal physiological conditions. Here, we investigate the relationship between proteasome function and larval salivary gland cell death during development in Drosophila. Drosophila larval salivary gland cells undergo synchronized programmed cell death requiring both caspases and autophagy (Atg) genes during development. Here, we show that ubiquitin proteasome system (UPS) function is reduced during normal salivary gland cell death, and that ectopic proteasome impairment in salivary gland cells leads to early DNA fragmentation and salivary gland condensation in vivo. Shotgun proteomic analyses of purified dying salivary glands identified the UPS as the top category of proteins enriched, suggesting a possible compensatory induction of these factors to maintain proteolysis during cell death. We compared the proteome following ectopic proteasome impairment to the proteome during developmental cell death in salivary gland cells. Proteins that were enriched in both populations of cells were screened for their function in salivary gland degradation using RNAi knockdown. We identified several factors, including trol, a novel gene CG11880, and the cop9 signalsome component cop9 signalsome 6, as required for Drosophila larval salivary gland degradation.

Human papillomavirus modifies the prognostic significance of T stage and possibly N stage in tonsillar cancer

BACKGROUND

Despite the association with more advanced nodal stage, patients with human papillomavirus (HPV) positive oropharyngeal cancers have better outcomes. We examined whether the HPV can modify the effect of known prognostic factors in tonsillar cancer.

PATIENTS AND METHODS

A total of 489 patients from 10 centres were followed up for recurrence or death for a median of 3.2 years. Determinants of the rate of locoregional recurrence, death from tonsillar cancer and overall survival were modelled using Cox regression.

RESULTS

The prognostic value of T and N stages were modified by HPV as indicated by statistically significant interaction terms. After adjusting for age, gender and treatment, T stage appeared relevant only for HPV-positive cancers (where a higher T stage was associated with worse outcomes). There was some evidence that N stage was a more relevant prognostic factor for HPV-negative than -positive cancers. There was no evidence that the HPV modifies the effect of age, gender or grade on outcomes.

CONCLUSIONS

This study suggests that the prognostic significance of the conventional staging system in tonsillar cancer is modified by HPV.

Gigacycle fatigue behavior by ultrasonic nanocrystalline surface modification

Nanocrystalline surface layer up to 84 microm in thick is produced on a specimen made of Al6061-T6 alloy by means of surface treatment called ultrasonic nanocrystalline surface modification (UNSM) technique. The refined grain size is produced in the top-layer and it is increased with increasing depth from the top surface. Vickers microhardness measurement for each nanocrystalline surface layer is performed and measurement results showed that the microhardness is increased from 116 HV up to 150 HV, respectively. In this study, fatigue behavior of Al6061-T6 alloy was studied up to 10(7)-10(9) cycles by using a newly developed ultrasonic fatigue testing (UFT) rig. The fatigue results of the UNSM-treated Al6061-T6 alloy specimens were compared with those of the untreated specimens. The microstructure of the untreated and UNSM-treated specimens was characterized by means of scanning electron microscopey (SEM) and transmission electron microscopey (TEM).

Construction and evaluation of high-quality n-ZnO nanorod/p-diamond heterojunctions

Vertically-aligned ZnO nanorods (NRs) arrays were synthesized by a low-temperature solution method on boron-doped diamond (BDD) films. The morphology, growth direction, and crystallinity of the ZnO NRs were studied by scanning electron microscopy, X-ray diffraction and cathodoluminescence. Electrical characterization of the ZnO NR/BBD heterostructures revealed characteristic p-n junction properties with an on/off ratio of about 50 at +/- 4 V and a small reverse leakage current approximately 1 microA. Moreover, the junctions showed an ideality factor around 1.0 at a low forward voltage from 0 to 0.3 V and about 2.1 for an increased voltage ranging from 1.2 to 3.0 V, being consistent with that of an ideal diode according to the Sah-Noyce-Shockley theory.

In-situ phosphrous doping in ZnTe nanowires with enhanced p-type conductivity

Single-crystalline undoped and phosphrous-doped (P-doped) p-type ZnTe nanowires (NWs) were synthesized via a simple vapor transport and deposition method. Both undoped and P-doped ZnTe nanowires have zinc blende structure and uniform geometry. X-ray diffraction peaks of the P-doped ZnTe nanowires show an obvious shift toward higher diffraction angle as compared with the undoped ZnTe nanowires. X-ray photoelectron spectroscopy confirms the existence of P-dopant in the ZnTe nanowires. Field-effect transistors based on both undoped and P-doped ZnTe nanowires were fabricated and characterized. Electrical measurements demonstrated that P-doping led to an enhancement in ptype conductivity of ZnTe nanowires. A defect reaction mechanism was proposed to explain the p-type behaviors of both undoped and P-doped ZnTe nanowires.

Rapid and sensitive detection of Pseudomonas aeruginosa in chlorinated water and aerosols targeting gyrB gene using real-time PCR

AIMS

For the rapid detection of Pseudomonas aeruginosa from chlorinated water and aerosols, gyrB gene-based real-time PCR assay was developed and investigated.

METHODS AND RESULTS

Two novel primer sets (pa722F/746MGB/899R and pa722F/746MGB/788R) were designed using the most updated 611 Pseudomonas and 748 other bacterial gyrB genes for achieving high specificity. Their specificity showed 100% accuracy when tested with various strains including clinical isolates from cystic fibrosis patients. The assay was tested with Ps. aeruginosa-containing chlorinated water and aerosols to simulate the waterborne and airborne transmission routes (detection limit 3·3 × 10² CFU per PCR-2·3 × 10³ CFU per PCR). No chlorine interference in real-time PCR was observed at drinking water level (c. 1 mg l⁻¹), but high level of chorine (12 mg l⁻¹) interfered the assay, and thus neutralization was needed. Pseudomonas aeruginosa in aerosol was successfully detected after capturing with gelatin filters with minimum 2 min of sampling time when the initial concentration of 10⁴ CFU ml⁻¹ bacteria existed in the nebulizer.

CONCLUSIONS

A highly specific and rapid assay (2-3 h) was developed by targeting gyrB gene for the detection of Ps. aeruginosa in chlorinated water and aerosols, combined with optimized sample collection methods and sample processing, so the direct DNA extraction from either water or aerosol was possible while achieving the desired sensitivity of the method.

SIGNIFICANCE AND IMPACT OF THE STUDY

  The new assay can provide timely and accurate risk assessment to prevent Ps. aeruginosa exposure from water and aerosol, resulting in reduced disease burden, especially among immune-compromised and susceptible individuals. This approach can be easily utilized as a platform technology for the detection of other types of micro-organisms, especially for those that are transmitted via water and aerosol routes, such as Legionella pneumophila.