Enhancing a clenbuterol immunosensor based on poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotube performance using response surface methodology

Clenbuterol (CLB) is an illegal antibiotic for livestock, which is misused as a growth promoter drug. In this study, an immunosensor modified with poly(3,4-ethylenedioxythiophene) (PEDOT), multi-walled carbon nanotubes (MWCNT) and anti-clenbuterol antibody (Ab) was developed for the detection of CLB. A screen-printed carbon electrode (SPCE) was modified with PEDOT/MWCNT as a sensor platform before immobilizing Ab for specific CLB binding through a competitive-type immunoassay. Free CLB in the sample solution competed with clenbuterol-horseradish peroxide (CLB–HRP) to bind with Ab. A high current signal was obtained after optimization of the electrochemical immunoassay conditions (pH, incubation temperature, antigen (Ag) incubation time and % blocking) using the response surface methodology/central composite design (RSM/CCD). The developed immunosensor is highly reproducible and sensitive with good storage stability, which are necessary for practical application. In real sample application, this immunosensor produces comparable results with liquid chromatography-mass spectrometry; thus, it is useful for CLB screening and monitoring in real meat samples.

A clenbuterol immunosensor was developed with a poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotube-modified screen-printed carbon electrode and optimized using response surface methodology.     

Toxicity of fungicides to Pisum sativum: a study of oxidative damage,growth suppression,cellular death and morpho-anatomical changes

Considering the fungicidal threat to the sustainable agro-environment, the toxicological impacts of three fungicides, namely kitazin, hexaconazole and carbendazim, on the biological, chemical and morpho-anatomical changes of peas were assessed. Fungicide applications in general caused a slow but gradual reduction in growth, symbiosis and yields of peas, which, however, varied appreciably among species and concentrations of the three fungicides. Of the three fungicides, carbendazim had the most lethal effect, in which it delayed seed germination and also diminished the overall pea growth. Carbendazim at 3000 μg kg⁻¹ maximally reduced the germination, SVI, size of roots and shoots and total dry matter accumulation in roots, shoots and whole plants distinctly by 40%, 84%, 72%, 73%, 68%, 75% and 73% (p ≤ 0.05), respectively. Hexaconazole at 120 μg kg⁻¹ significantly (p ≤ 0.05) declined total chlorophyll, carotenoids, grain yields, grain protein, root P and shoot N by 19%, 28%, 46%, 69%, 48% and 51%, respectively, over the control. The synthesis of stress biomarkers and oxidative stress were increased with increasing dosage rates of fungicides. Proline content in roots, shoots, leaves and grains, MDA, electrolyte leakage and H₂O₂ of plants grown in soil treated with 288 μg kg⁻¹ kitazin were increased significantly (p ≤ 0.05) by 73%, 52%, 41%, 24%, 59%, 40% and 27%, respectively, relative to the control. Antioxidant defence enzymes were greater in pea foliage. The SEM and CLSM images revealed an obvious alteration in root tips, enhanced cellular damage and cell death when plants were raised under fungicide stress. Also, morpho-anatomical variations in fungicide-treated foliage were visible in the SEM images. Overall, the present study suggests that a careful and secure strategy should be adopted before fungicides are chosen for enhancing pulse production in different agro-climatic regions.

Considering the fungicidal threat to the sustainable agro-environment, the toxicological impacts of three fungicides, namely kitazin, hexaconazole and carbendazim, on the biological, chemical and morpho-anatomical changes of peas were assessed.     

Synthesis and biological study of acridine-based imidazolium salts

A new series of acridine based imidazolium salts was synthesized and evaluated for in vitro cytotoxicity against human cancer cell lines by an MTT assay. The synthesis applied a coupling of imidazoles with 9-chloroacridines, which originated from an Ullmann condensation of a 2-chloro-benzoic acid with an aniline. The target compounds were obtained in high yields. The DPPH assay indicated considerable antioxidant activity for target compounds with simple and short alkyl chains on the imidazole, while increasing chain length and the introduction of an additional π-electron system in most cases reduced the activity. All compounds exhibited low biotoxicity against non-cancerous cell lines, whereas a few compounds showed promising anticancer activity. Unlike for the reference drugs Tamoxifen and Paclitaxel, the anticancer activity of acridine imidazolium ions is specific for only selected cancer types. Reasonable fluorescent behaviour of the products provide potential for visualization of the distribution of active drugs in tissue.

A series of acridine-based imidazolium salts was synthesized and studied on cytotoxicity against human cancer cell lines.     

Re-visiting pH-adjusted potassium to avoid hypokalemic crisis during management of diabetic ketoacidosis: A conceptual framework

Background and aimsDiabetic ketoacidosis (DKA) treatment guidelines recommend to initiate potassium-replacement when serum potassium (S_K) drops within normal range, and to withhold insulin if S_K is below normal. Despite strict recommendations, hypokalemia is frequently observed in DKA.MethodsScientific literature was thoroughly searched to find 1) DKA treatment guidelines, 2) studies reporting hypokalemia in DKA, 3) and literature elaborating mechanisms involved in hypokalemia.ResultsAcidosis affects S_K and its regulators including insulin, catecholamines and aldosterone. Current conceptual framework is an argument to gauge the degree of hypokalemia before it strikes DKA patients utilizing S_K level after adjusting it with pH. Suggested approach will reduce hypokalemia risk and its associated complications. The nomogram calculates pH-adjusted potassium and expected potassium loss. It also ranks hypokalemia associated risk, and proposes the potassium-replacement rate over given time period. The differences between current DKA treatment guidelines and proposed strategy are also discussed. Moreover, reasons and risk of hyperkalemia due to early initiation of potassium replacement and remedial actions are debated.ConclusionIn light of proposed strategy, utilizing the nomogram ensures reduced incidence of hypokalemia in DKA resulting in improved clinical and patient outcomes. Pharmacoeconomic benefits can also be expected when avoiding hypokalemia ensures early discharge.     

Characterisation at the Bonding Zone between Fly Ash Based Geopolymer Repair Materials (GRM) and Ordinary Portland Cement Concrete (OPCC)

In recent years, research and development of geopolymers has gained significant interest in the fields of repairs and restoration. This paper investigates the application of a geopolymer as a repair material by implementation of high-calcium fly ash (FA) as a main precursor, activated by a sodium hydroxide and sodium silicate solution. Three methods of concrete substrate surface preparation were cast and patched: as-cast against ordinary Portland cement concrete (OPCC), with drilled holes, wire-brushed, and left as-cast against the OPCC grade 30. This study indicated that FA-based geopolymer repair materials (GRMs) possessed very high bonding strength at early stages and that the behavior was not affected significantly by high surface treatment roughness. In addition, the investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy have revealed that the geopolymer repair material became chemically bonded to the OPC concrete substrate, due to the formation of a C–A–S–H gel. Fundamentally, the geopolymer network is composed of tetrahedral anions (SiO₄)⁴⁻ and (AlO₄)⁵⁻ sharing the oxygen, which requires positive ions such as Na⁺, K⁺, Li⁺, Ca²⁺, Na⁺, Ba²⁺, NH⁴⁺, and H₃O⁺. The availability of calcium hydroxide (Ca(OH)₂) at the surface of the OPCC substrate, which was rich in calcium ions (Ca²⁺), reacted with the geopolymer; this compensated the electron vacancies of the framework cavities at the bonding zone between the GRM and the OPCC substrate.     

Synergistic Effects of Pr6O11 and Co3O4 on Electrical and Microstructure Features of ZnO-BaTiO3 Varistor Ceramics

This paper investigated the effects of Pr₆O₁₁ and Co₃O₄ on the electrical properties of ZnO-BaTiO₃ varistor ceramics. The Pr₆O₁₁ doping has a notable influence on the characteristics of the nonlinear coefficient, varistor voltage, and leakage current where the values varied from 2.29 to 2.69, 12.36 to 68.36 V/mm and 599.33 to 548.16 µA/cm², respectively. The nonlinear varistor coefficient of 5.50 to 7.15 and the varistor voltage of 7.38 to 8.10 V/mm was also influenced by the use of Co₃O₄ as a dopant. When the amount of Co₃O₄ was above 0.5 wt.%, the leakage current increased from 202.41 to 302.71 μA/cm². The varistor ceramics with 1.5 wt.% Pr₆O₁₁ shows good nonlinear electrical performance at higher breakdown voltage and reduced the leakage current of the ceramic materials. Besides, the varistor sample that was doped with 0.5 wt.% Co₃O₄ was able to enhance the nonlinear electrical properties at low breakdown voltage with a smaller value of leakage current.     

Role of Sintering Temperature in Production of Nepheline Ceramics-Based Geopolymer with Addition of Ultra-High Molecular Weight Polyethylene

The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm⁻¹ becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.     

Factors associated with return to work of breast cancer survivors: a systematic review

Background

The breast cancer survival rate is the highest among all types of cancers, and survivors returning to work after completing treatment is extremely important in regards to economy and rehabilitation. The aim of this systematic review study is to identify the prevalence of breast cancer survivors who return to work (RTW) and the factors associated to RTW.

Methods

A computer based literature search was carried out. "PubMed, Cochrane Library, Embase, Web of Science, and Science Direct" databases were searched systematically. Our search strategy identified a total of 12,116 papers of which 26 studies met the inclusion criteria and quality assessment. These were original papers published between January 2003 and January 2013.

Results

The trends in RTW differ among countries for the breast cancer survivors. The time to RTW after successful cancer treatment also varies among the countries and by ethnicity. The prevalence of the RTW varies from 43% to 93% within one year of diagnosis. The prevalence of the RTW for the Netherland is the lowest in the world (43%). The United States survivors showed the highest RTW (93%) within 12 months of the diagnosis. Numerous barriers and facilitators were identified as factors that affect RTW. For instance, socio-demographic factors such as education and ethnicity; treatment oriented factors such as chemotherapy; work related factors such as heavy physical work; disease related factors such as poor health condition and fatigue; and psychological factors such as depression and emotional distress, act as barriers of RTW. In contrast, social, family, employer support, and financial independency emerge as key facilitators in enabling breast cancer survivors to return and continue work.

Conclusion

Minimising these identified barriers and strengthening these facilitators could further improve the work condition and increase the percentage of RTW among the breast cancer survivors.

     

Is the burden of oral diseases higher in urban disadvantaged community compared to the national prevalence?

Background

The urban low income has often been assumed to have the greatest dental treatment needs compared to the general population. However, no studies have been carried out to verify these assumptions. This study was conducted to assess whether there was any difference between the treatment needs of an urban poor population as compared to the general population in order to design an intervention programme for this community.

Methods

A random sampling of living quarters (households) in the selected areas was done. 586 adults over 19 years old living in these households were clinically examined using World Health Organization (WHO) Oral Health Survey criteria 4th edition (1997).

Results

The overall prevalence of dental caries, periodontal disease, denture wearers and temporomandibular joint problems were 70.5%, 97.1%, 16.7% and 26%, respectively. The majority (80.5%) needed some form of dental treatment. The highest treatment needs were found in the oldest age group while the lowest were in the youngest group (19-29 years) (p = 0.000). The most prevalent periodontal problem was calculus; regardless of gender, ethnicity and age. Significantly more females (20.5%) wore prosthesis than males (11.1%) (p = 0.003). Prosthetic status and need significantly increased with age (p = 0.000). About one in four adults had Temporo-Mandibular Joint (TMJ) problems. Overall, it was surprising to note that the oral disease burden related to caries, prosthetic status and treatment need were lower in this population as compared to the national average (NOHSA, 2010). However, their periodontal disease status and treatment needs were higher compared to the national average indicating a poor oral hygiene standard.

Conclusions

The evidence does not show that the overall oral disease burden and treatment needs in this urban disadvantaged adult population as higher than the national average, except for periodontal disease. The older age groups and elderly were identified as the most in need for oral health intervention and promotion. An integrated health intervention programme through a multisectoral common risk factor approach in collaboration with the Faculties of Medicine, Dentistry and other agencies is needed for the identified target group.

     

How much energy is locked in the USA? Alternative metrics for characterising the magnitude of overweight and obesity derived from BRFSS 2010 data

Objectives

Four metrics to characterise population overweight are described.

Methods

Behavioural Risk Factors Surveillance System data were used to estimate the weight the US population needed to lose to achieve a BMI < 25. The metrics for population level overweight were total weight, total volume, total energy, and energy value.

Results

About 144 million people in the US need to lose 2.4 million metric tonnes. The volume of fat is 2.6 billion litres—1,038 Olympic size swimming pools. The energy in the fat would power 90,000 households for a year and is worth around 162 million dollars.

Conclusions

Four confronting ways of talking about a national overweight and obesity are described. The value of the metrics remains to be tested.