A cursory study of the bulk and glaze composition plus metal leaching properties of a selection of antique, vintage and present day food and drink ceramic wares using XRF, FTIR, ²⁷Al, ²⁹Si, ³¹P MAS NMR and ICP-MS for providing a characterisation of the types of domestic ceramic ware used in New Zealand currently

The ceramic utensils used for eating and drinking such as plates, cups, bowls and other items have been a fundamental part of many societies since ancient times. The word “ceramics” is itself derived from the Greek word κεραμικός (“Keramikos”)¹ meaning “of or for pottery”. The art of making ceramics dates back thousands of years with evidence of pottery from 20,000 years ago² being reported recently from Xianrendong Cave in China. Ceramics manufacture depends on a source of various materials, namely clay, e.g. kaolinite, silica and feldspar.³ When these clay and mineral materials are mixed and soaked in water with removal of the excess water, a wet clay is produced which can then be fashioned into the desired shapes using moulds. Water is then removed via drying and the articles fired at temperatures up to 1170 °C during which complex chemical transformations occur in the clay with physical changes in the added silica and feldspar. Kaolinite (Al₂Si₂O₅(OH)₄ ) is converted via a series of precursor compounds to mullite (Al₆Si₂O₁₃) and cristobalite (SiO₂). The feldspar acts as a flux with the alkali metal ion content (Na₂O, K₂O and CaO) causing a lowering of the melting point of the silica early on in the firing process. This melt effectively forms a glass which then draws the individual particles of the fired mixture together and additionally reacts with them so giving the ceramic body strength (when it cools) and reducing porosity

A Study of Differences in Calculated Capacity when Using Single-, Mixed- or Multiple-Bounce GSCM Schemes

The paper looks for differences in MIMO system capacity when using either single-, mixed-, or multiple-bounce geometry based stochastic channel models (GSCMs). The investigation considers Saleh-Valenzuela temporal indoor model, expanded for angular domain. In the model omnidirectional and idealized sector antennas were used as array elements. The single-bounce assumption, combination of single and multiple bounces, and pure random multiple bounces assumption were compared within “temporally identical” environment regarding the overall MIMO capacity. Assumption of clustered scatterers/reflectors is used in all three cases. The comparison is performed in statistical sense, using a large number of stochastically generated temporal models. The model is two- dimensional, i.e. neither elevation angle nor polarization/ depolarization was considered

Biomedicals from Bone

The realm of biomaterials, under which biomedical materials can be categorised, has a broad definition base and recognises materials that are synthesized or naturally sourced. Biomaterials are normally those that come into contact with live tissue and physiological fluids. They have applications as prostheses to replace lost function of joints or to replace bone tissue, for diagnosing medical conditions, as a form of therapy, or as a storage unit. The diversity and scope of biomaterials science research, and especially its application to the improvement of trauma, disease, and congenital defects in the human condition, are making this branch of science increasingly dominant and topical in many countries. An exciting aspect is that such research is interdisciplinary. The varied problems of the human condition that biomaterials research addresses occupy the efforts not only of medical doctors who act as the end users of such technology, but also those of chemists, physicists, engineers, and biologists in creating the technological advances. Chemistry, in particular, plays a major role in such research, after all it is the foundation stone on which biomaterials polymer science and biomedical scaffold materials are built

In Situ IR Study of the Anodic Polarization of Gold Electrodes in Polar Aprotic Solvents: DMSO and DMF Solutions of Cyanate, Thiocyanate and Selenocyanate Ions

Subtractively normalised Fourier transform infrared spectroscopic (SNIFTIRS) studies combined with volammetric and supporting model solution studies have conclusively shown that Au electrodes anodically polarized in DMSO and DMF solutions containing the pseudohalide ions: cyanate, thiocyanate and selenocyanate with tetrabutylammonium perchlorate as supporting electrolyte dissolve to form Au(I) pseudohalide complex ions (i.e. [Au(NCO)₂]⁻, [Au(SCN)₂]⁻ and [Au(SeCN)₂]⁻. This work has demonstrated the significance of the Au(I) oxidation state which occurs after applied voltages of +500 mV(AgCl/Ag) in the little characterized electrochemistry of this metal in polar aprotic solvents, DMSO and DMF The Au(I) species observed electrochemically by SNIFTIRS were confirmed by independent preparation in DMSO/DMF containing mixtures of KAuBr₄ and the pseudohalide salt (KOCN/NaSCN/KSeCN) and exploiting fortuitous redox chemistry where Au(I) formed spontaneously. The model solutions examined by transmission FTIR and ESI-MS confirmed the existence of the Au(I) species posited in the SNIFTIRS experiments but additionally revealed other interesting side reactions occurring in the model solutions

Melt-extruded polyethylene oxide (PEO) rods as drug delivery vehicles: Formulation, performance as controlled release devices and the influence of co-extruded excipients on drug release profiles

The utility of controlled release medication formulations lies in their ability to keep drugs at steady levels in the blood plasma of recipients and within the termini of the maximum and minimum effective therapeutic levels. This avoids the “ups” and “downs” of medication levels within the body which would have been the result had conventional immediate release tablets been administered instead. In the veterinary field, controlled release medications are essential¹ because of the logistical difficulties of administering drugs on a regular (e.g., daily) basis to animals. The chief advantages of controlled release veterinary medications lie in the ease with which they can be administered; decrease in stress for animals, owing to less need for rounding up and frequent dosing; and, most importantly for farmers, the reduced cost of treatment relative to that for a multiple dosage regime

Anodically polarized nickel electrodes in DMSO or DMF solutions of pseudohalide ions: IR spectroelectrochemical studies

A novel subtractively normalized interfacial Fourier transform infrared spectroscopic (SNIFTIRS) investigation of anodically polarized nickel electrodes in pseudohalide-containing DMF or DMSO solutions (i.e. OCN⁻, SCN⁻, SeCN⁻), in supporting electrolyte, tetrabutylammonium perchlorate (TBAP), is presented. In general, the data showed that nickel demonstrated irreversible anodic dissolution in all solutions studied at very high values of the applied potential, > +500 mV (AgCl/Ag). The predominant speciation of nickel in these systems was as complex ions consisting of Ni²⁺ ion complexed to pseudohalide ions and solvent molecules. Insoluble films and dissolved CO₂ were also detected, though mostly in the Ni/OCN⁻ systems studied. Ni(II)/pseudohalide complex ion species detected were modeled using solutions containing Ni²⁺ ion mixed with pseudohalide ion in different mole ratios. In general, the Ni/OCN⁻ electrochemical system behaved differently relative to those of Ni/SCN⁻ and Ni/SeCN⁻ due to the difference in colors observed in cell solutions after SNIFTIRS experiments which was mirrored in the model solutions. Ni(II)-cyanate species had a different, coordination geometry and gave a characteristic bright blue color due possibly to Ni(NCO)₄²⁻ ion while Ni(II) thiocyanate and selenocyanate complex ion species had octahedral coordination geometries containing solvent and one coordinated pseudohalide ion and formed greeny yellow solutions

A combined SNIFTIRS and XANES study of electrically polarised copper electrodes in DMSO and DMF solutions of cyanate (NCO⁻), thiocyanate (NCS⁻) and selenocyanate (NCSe⁻) ions

A SNIFTIRS (subtractively normalized interfacial Fourier transform infrared spectroscopy) and X-ray absorption spectroscopy (XAS) study of electrically polarized copper electrodes in six polar aprotic solvent-based systems is presented. In the systems investigated, i.e. dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) solutions containing pseudohalide species of cyanate (NCO⁻), thiocyanate (NCS⁻) and selenocyanate (NCSe⁻) codissolved with tetrabutylammonium perchlorate (TBAP), Cu was found to dissolve over a wide range of potentials to produce the corresponding Cu(I) pseudohalide and/or Cu(II) pseudohalide complex ion species. Insoluble deposited films were also observed at higher anodic applied potentials, thought to be CuSCN in the Cu/NCS⁻/DMSO or DMF systems, and solid K(SeCN)₃ in the Cu/NCSe⁻/DMSO or DMF systems respectively. The presence of the Cu(II) and/or Cu(I) oxidation states in complexes formed by polarization in Cu/pseudohalide ion systems in DMSO was clearly proven using XAS of cell solutions sampled after SNIFTIRS/electrical polarization experiments. In addition, Fourier transform infrared (FTIR) and X-ray absorption near edge spectroscopy (XANES) data obtained from model solutions prepared from mixing Cu(I) and/or Cu(II) salts with the respective pseudohalide ions in DMF and DMSO confirmed the speciation observed in the electrochemical experiments

Smilje (Helichrysum italicum /Roth/ G.Don): od tradicionalne uporabe do znanstvenih istraživanja

Sredozemno smilje (Helichrysum italicum /Roth/ G. Don) aktualna je tema mnogih znanstvenih istraživanja u zadnjem desetljeću, a zanimanje znanstvene zajednice za ovu biljnu vrstu potaknuto je njenom tradicionalnom primjenom. Najviše korišteni biljni dijelovi su cvjetovi i listovi, a primjenjuju se u liječenju zdravstvenih poremećaja poput alergija, prehlada, kašlja, kožnih, jetrenih i žučnih oboljenja. Eterično ulje smilja složenog je kemijskog sastava i posjeduje snažna biološka svojstva. Ova biljna vrsta ima veliki ekonomski značaj čime je izvršen pritisak na njena prirodna staništa. Kako bi se spriječila prekomjerna eksploatacija prirodnih populacija, Republika Hrvatska je odredila rokove berbe u kojima je dozvoljeno skupljanje svježe herbe smilja u komercijalne svrhe. U posljednjih nekoliko godina, zbog povećane tržišne potražnje, zasađeno je nekoliko plantažnih nasada smilja u Hrvatskoj, a domaći proizvodi su zahvaljujući svojoj kvaliteti prepoznati od strane potrošača.Immortelle (Helichrysum italicum /Roth/ G. Don) is a topic of many scientific investigations in the last decade and the interest of the scientific community for this plant species is motivated by its traditional use. In Mediterranean countries flowers and leaves are the plant parts mostly used in the treatment of health disorders. The essential oil has a complex chemical composition with strong biological properties. This plant species has a huge economic importance which causes great pressure on natural populations due to massive overexploitation. In order to prevent excessive exploitation Croatia has determined deadlines for gathering wild populations for commercial purposes. Due to increased market demand for H. italicum several plantations have been established in Croatia in recent years and the quality of its products has been recognize by the consumers

Longterm effect of American ginseng extract (Panax quinquefolius L.) on glycemic control in type 2 diabetic patients

Dosadašnja klinička istraživanja upućuju na zaključak da američki ginseng (AG) pridonosi regulaciji glikemije na način da, slično djelovanju derivata sulfonilureje, povećava postprandijalnu koncentraciju inzulina u serumu. Stoga je cilj ovog istraživanja bio ispitati učinkovitost i sigurnost odabranog ekstrakta američkog ginsenga kao dopune uobičajenoj terapiji ŠBT2 (prehrana i/ili lijekovi), koristeći randomizirani, dvostruko-slijepi, placebom-kontrolirani, paralelni dizajn studije i posljedično pridonijeti razumijevanju predloženog mehanizma djelovanja ekstrakta američkog ginsenga u regulaciji glikemije u bolesnika sa ŠBT2. Sedamdeset četiri ispitanika s kontroliranom ŠBT2 (spol: 28 M i 46 Ž; dob: 62,9 ± 9,49 godina; ITM: 32 ± 5,3 kg/m2; HbA1c: 7,0 ± 1,3%), randomiziranih u intervencijsku (n = 35) ili kontrolnu skupinu (n = 39), završilo je studiju. Svakom je ispitaniku bio dodijeljen ili odabrani preparat AG-a (etanolni ekstrakt korijena) ili placebo koji sadrži pšenične mekinje (2 kapsule od 500 mg po obroku = 3 g dnevno) u razdoblju od 12 tjedana. Ishodi mjerenja uključivali su mjere učinkovitosti (hemoglobin A1c (HbA1c)-primarni, koncentracija glukoze u plazmi natašte (GUP-NT), koncentracija inzulina u serumu natašte i model procjene homeostaze (HOMA-IR)); sigurnosti primijenjene terapije (jetrena i bubrežna funkcija, koagulacijski parametri, arterijski tlak i arterijska elastičnost) i suradljivosti (broj vraćenih kapsula). Među ispitanim skupinama nije bilo statistički značajne razlike u vrijednostima hemoglobina A1c kao primarnog ishoda istraživanja. Ipak, u usporedbi s placebom, u skupini koja je uzimala AG uočen je silazni trend vrijednosti hemoglobina A1c za 0,84% (P = 0,836) te su ispitanici za vrijeme studije ostali dobro kontrolirani (HbA1c = 7,12%). Odabrani pripravak AG-a također je smanjio koncentraciju GUP-a u plazmi natašte za 4,42%, koncentraciju inzulina u serumu natašte za 11,54% i vrijednosti HOMA-IR indeksa za 18,84%, bez statistički značajne razlike među uspoređivanim skupinama (P = 0,947, P = 0,373, P = 0,489, za svaki pojedinačno). Razlika početnih i krajnjih vrijednosti vaskularnih pokazatelja između dviju skupina, i to sistoličkog arterijskog tlaka (SAT) i augmentacijskog indeksa (AI), bila je statistički značajna. U usporedbi s placebom, AG u primijenjenoj dozi značajno je smanjio radijalni AI za 5,25% (P = 0,041) i SAT za 11,72% (P < 0,001), dok je izostao učinak na dijastolički arterijski tlak. Ishodi sigurnosti i suradljivosti ostali su također nepromijenjeni. Dobiveni rezultati upućuju na zaključak da nakon 12 tjedana suplementacije ekstrakt AG-a, iako ne smanjuje vrijednost HbA1c, održava zadovoljavajuću kontrolu glikemije u bolesnika s reguliranom ŠBT2, bez nuspojava.According to previous clinical studies it has been suggested that American ginseng (AG) is effective in improving glycemic control in type 2 diabetes through increasing post-prandial insulin levels, much like the conventional therapy sulphonylurea. The aim of the present study was to test the efficacy and safety of 12 weeks of supplementation with the selected AG extract as an adjunct to usual therapy in people with type 2 diabetes (diet and/or conventional diabetes therapy), using a randomized, double-blind, placebo-controlled design, and subsequently to contribute to better understanding of the proposed mechanism of action of the American ginseng extract in glucose regulation in type 2 diabetes. Seventy-four participants with well-controlled type 2 diabetes (sex: 28 M and 46 F, age: 62.9 ± 9.49, BMI: 32 ± 5.3, HbA1c: 7.0 ± 1.3), randomized to either intervention (n = 35) or control (n = 39) group, completed the study. Participants were randomly assigned to one of the two interventions and received, prior to each of the main meals, three times daily two 500 mg capsules (total 3g/ day), of either American ginseng extract or identical-appearing placebo capsules containing wheat bran. Outcomes included measures of efficacy (glycated hemoglobin (HbA1c)-primary, fasting plasma glucose (FPG), fasting plasma insulin (FPI), homeostasis model assessment (HOMA-IR)); safety (liver and kidney function, haemostatic function, blood pressure and arterial stiffness); and compliance (returned capsules). There was no change in the primary endpoint, HbA1c, between the treatment and placebo groups. Nevertheless, there was a trend toward lower HbA1c by 0.84% (P = 0.836) compared to placebo. Furthermore, the participants remained well-controlled (HbA1c = 7.12%) throughout. The selected AG treatment also decreased FPG, FPI and HOMA by 4.42%, 11.54% and 18.84%, respectively, with no significant between-treatment difference (P = 0.947, P = 0.373, P = 0.489, respectively). Between-treatment end differences of vascular parameters, namely systolic blood pressure (SBP) and augmentation index (AI) were statistically significant. Compared to placebo, 3 g of AG significantly lowered radial AI by 5.3% (P = 0.041) and systolic BP by 11.7% (P< 0.001) at 12 weeks. No effect was observed with diastolic BP. Safety and compliance outcomes remained unchanged. The study results indicate that after 12-weeks of supplementation, even though the AG extract did not decrease HbA1c levels, it maintained good glycemic control in patients with well-controlled type 2 diabetes without adverse effects