Danielle Meyrick

Synthesis and improved electrochemical performances of nano β-NiMoO4–CoMoO4·xH2O composites for asymmetric supercapacitors

Nano-sized β-NiMoO4–CoMoO4·xH2O composites were synthesized by a solution combustion synthesis (SCS) technique. The effect of weight ratio of transition metal on the electrochemical capacitive performance of the nanocomposites was investigated by cyclic voltammetry and galvanostatic charge–discharge methods. The NiMoO4–CoMoO4·xH2O nanocomposite with weight ratio of 3:1 (Ni:Co) exhibits enhanced capacitive behaviour relative to other composites and delivered a maximum specific capacitance of 1472 Fg−1 at a current density of 5 mAcm−2. The enhancement in specific capacitance is due to the small particle size, uniform size distribution, high surface area and high weight fraction of Ni. The synergistic effect of nickel and cobalt improves the electrochemical behaviour relative to pure nickel and cobalt molybdates. A full cell was fabricated using the β-NiMoO4–CoMoO4·xH2O nanocomposite (3:1) and activated carbon (AC) as a positive and negative electrode, respectively. The cell delivered high capacitance (80 Fg−1) and energy density (28 Wh kg−1) and good cycling stability up to 1000 cycles.

Electrochemical performances of CoFe2O4 nanoparticles and a rGO based asymmetric supercapacitor

CoFe2O4 nanoparticles were prepared using a polyethylene glycol (PEG) assisted solution combustion method. The X-ray diffraction pattern, Fourier transform infrared and Raman spectra revealed the single phase formation of CoFe2O4 particles. Transmission electron microscopy (TEM) images revealed nanosized particles less than 10 nm in size. The calculated voltammetry specific capacitance of the CoFe2O4 electrode was 195 F g−1 at 1 mV s−1. The Powers law suggests the capacitive mechanism is dominant over an intercalation mechanism, while the maximum number of charges accommodated in the inner surface of the electrode, is given by the Trasatti plot. The fabricated rGO based hybrid supercapacitor (CoFe2O4‖rGO) provides a good specific capacitance (38 F g−1) and energy density (12.14 W h kg−1) at 3 mA with good cycle life, and the serially connected asymmetric supercapacitor device powers the light emitting diode for 10 minutes.

Electrodeposition of manganese dioxide: effect of quaternary amines

The effect of quaternary ammonium salts (tetraethyl ammonium bromide, tetrapropyl ammonium bromide, and tetrabutyl ammonium bromide) on the structural, morphological, and electrochemical characteristics of electrolytic manganese dioxide (EMD) obtained from acidic aqueous sulfate solution has been investigated. Physical characterization of the EMD was achieved by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis, and Fourier transform infrared spectroscopy. The charge–discharge profile of the materials was determined to evaluate their potential for alkaline battery applications. The presence of these quaternary ammonium salts as organic additives in the solution increased the current efficiency while decreasing energy consumption during electrochemical deposition of manganese dioxide (MnO2). All the additives influenced the discharge characteristics of the EMD samples significantly, producing a cathode material with increased cumulative discharge capacity relative to EMD prepared in the absence of additives. This is attributed to the ability of the additives to affect the particle size and morphology, and therefore electrochemical activity, of electrodeposited materials; the effects in the case of the additives investigated in this work were positive, producing a material with potential application to battery technology.

Iron and iron proteins found in the genetic disease, hereditary spherocytosis

Hereditary spherocytosis (HS) is a disorder of the red blood cell (RBC) membrane, characterized by abnormally fragile and spherical RBCs. It is the predominant cause of haemolytic anaemia in people of northern European descent. Owing to the increased rate of RBC synthesis that is characteristic of the condition, it may result in an increase in absorption of iron from the diet by the affected individual. Ultimately, pathological iron overload may develop. Fortunately, the condition responds well to surgical removal of the spleen (splenectomy). In this project, iron studies were performed on a set of spleen tissue samples obtained following routine splenectomy for HS. Cell architecture and level of deposition of haemosiderin, the distinctive form of iron found in iron-loaded tissues, were assessed. The tissue iron content was determined by AAS and ICP (mean value=2276±507 μg g-1 dry tissue, values reported for normal spleens range from 972±60 to 1345±190 μg g-1). Ion exchange chromatography was employed to separate the protein content of the tissue into four chromatographic bands, notionally transferrin, ferritin, haemprotein and haemosiderin, and these proteins quantified. Mossbauer spectroscopy identified the iron as Fe(III), predominantly in ferrihydrite (5Fe2O3·9H2O) and haem environments within the tissue. Typical spectral parameters, recorded at 300 K, were: isomer shift and quadrupole splitting of 0.36 and 0.62 mm s-1, respectively, (ferrihydrite) and 0.14 and 1.97 mm s-1 (haem). The results indicate a condition corresponding to mild iron overload.

Review of Gallium-68 PSMA PET/CT Imaging in the Management of Prostate Cancer

Over 90% of prostate cancers over-express prostate specific membrane antigen (PSMA) and these tumor cells may be accurately targeted for diagnosis by 68Ga-PSMA-positron emission tomography/computed tomography (68Ga-PSMA-PET/CT) imaging. This novel molecular imaging modality appears clinically to have superseded CT, and appears superior to MR imaging, for the detection of metastatic disease. 68Ga-PSMA PET/CT has the ability to reliably stage prostate cancer at presentation and can help inform an optimal treatment approach. Novel diagnostic applications of 68Ga-PSMA PET/CT include guiding biopsy to improve sampling accuracy, and guiding surgery and radiotherapy. In addition to facilitating the management of metastatic castrate resistant prostate cancer (mCRPC), 68Ga-PSMA can select patients who may benefit from targeted systemic radionuclide therapy. 68Ga-PSMA is the diagnostic positron-emitting theranostic pair with the beta emitter Lutetium-177 PSMA (177Lu-PSMA) and alpha-emitter Actinium-225 PSMA (225Ac-PSMA) which can both be used to treat PSMA-avid metastases of prostate cancer in the molecular tumor-targeted approach of theranostic nuclear oncology.

Role of hydrazine and hydrogen peroxide in aluminium hydroxide precipitation from sodium aluminate solution

Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while higher amount of hydrogen peroxide is required to generate similar effect. XRD data confirm the product phase to be gibbsitic by nature. The scanning electron micrographs (SEM) show that agglomerated products form in the presence of hydrazine while fine discrete particles are produced with hydrogen peroxide. The probable mechanism of precipitation in the presence of hydrazine and hydrogen peroxide is also discussed.

The role of 68ga-psma-i&t Pet/ct in the pretreatment staging of primary prostate cancer

Objectives This retrospective study aimed to evaluate the role of 68Ga-PSMA-I&T PET/CT in the primary staging of newly diagnosed prostate cancer (PCa), with a focus on the detection of metastatic nodal disease. Correlation of the rate of detection of metastatic disease by 68Ga-PSMA-I&T PET/CT with the Gleason score (GS) and serum prostate-specific antigen (PSA) was performed to determine the GS and PSA criteria defining patients who would benefit from 68Ga-PSMA-I&T PET/CT imaging for staging, risk stratification and therapy optimization. Patients and methods Patient data and images from 70 patients with a recent diagnosis of prostate cancer who had undergone 68Ga-PSMA-I&T PET/CT were analysed retrospectively. Data and images were analysed for the rate of detection of primary and metastatic PCa, and correlation with PSA and GS. Results The rate of detection of primary tumour by 68Ga-PSMA-I&T for patients with serum PSA less than 5 ng/ml was 73%. The corresponding rate was 90% for patients with PSA 5–10 ng/ml and 97% for patients with PSA more than 10 ng/ml. Metastatic PCa and/or infiltrative disease was detected in 24/70 study patients in total: 1/11 patients with PSA less than 5 ng/ml and 23/59 patients with serum PSA at least 5 ng/ml. The rate of detection of metastatic PCa was greater in patients with GS 9 or more (48%) relative to those with GS 8 (32%) or GS ⩽7 (18%). Conclusion A role for 68Ga-PSMA-I&T PET/CT in primary PCa staging of high-grade disease (GS 8 or more and PSA >10 ng/ml) has been shown. There was a low rate of detection of PSMA-avid metastases in low-grade disease (GS 7 or less and PSA <5 ng/ml), suggesting that there is a limited role for this modality in such cases.

Erratum to: Electrodeposition of manganese dioxide: effect of quaternary amines

The effect of quaternary ammonium salts (tetraethyl ammonium bromide, tetrapropyl ammonium bromide, and tetrabutyl ammonium bromide) on the structural, morphological, and electrochemical characteristics of electrolytic manganese dioxide (EMD) obtained from acidic aqueous sulfate solution has been investigated. Physical characterization of the EMD was achieved by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis, and Fourier transform infrared spectroscopy. The charge–discharge profile of the materials was determined to evaluate their potential for alkaline battery applications. The presence of these quaternary ammonium salts as organic additives in the solution increased the current efficiency while decreasing energy consumption during electrochemical deposition of manganese dioxide (MnO2). All the additives influenced the discharge characteristics of the EMD samples significantly, producing a cathode material with increased cumulative discharge capacity relative to EMD prepared in the absence of additives. This is attributed to the ability of the additives to affect the particle size and morphology, and therefore electrochemical activity, of electrodeposited materials; the effects in the case of the additives investigated in this work were positive, producing a material with potential application to battery technology.