Bare Particulars Laid Bare

Bare particulars have received a fair amount of bad press. Many find such entities to be obviously incoherent and dismiss them without much consideration. Proponents of bare particulars, on their part, have not done enough to clearly motivate and characterize bare particulars, thus leaving them open to misinterpretations. With this paper, I try to remedy this situation. I put forward a much-needed positive case for bare particulars through the four problems that they can be seen to solve—The Problem of Individuation, The Problem of Change, The Problem of Having a Property, and The Problem of Subtraction. I then distinguish and characterize three possible types of bare particulars—genuinely bare, constitutively bare, and thinly clothed—and consider how each of these cope with some classical and recent objections to bare particulars. I argue that the most troubling objections do not come from familiar quarters, but from examining how well such entities address all four of the ontological problems outlined. I ultimately conclude that the best contenders among the three types of bare particulars are the constitutively bare variety, but argue that, if they are to earn their keep, they must either share or turn over their individuating role to the ordinary particulars that they constitute.     

Synthesis,characterization and antimicrobial activity of β-aminovinylphosphonium salts derived from aromatic amino acids

This study presents the synthesis, characterization and antimicrobial activity evaluation of β-aminovinyl-phosphonium salts derived from aromatic amino acids. The compounds were prepared in the reaction of (formylmethyl)triphenylphosphonium chloride with various aromatic amino acids and their structures were determined by elemental analysis, IR and NMR spectroscopy. All synthesized compounds were tested for their antibacterial and antifungal activity.     

Determination of Nitrates in Water Samples by In‐Electrode Coulometric Titration in Copper Coated Porous Vitreous Carbon Electrode

Nitrate in water samples was determined by in‐electrode coulometric titration in porous electrode made of vitreous carbon particles coated with copper. The sample was mixed with diluted sulfuric acid containing 1 mmol/L hydrochloric acid, the solution was filled into the cell and electrode and the nitrate ions were directly reduced by constant current to ammonium ions. The stoichiometry of the electrode reaction was found by coulometric and photometric measurements. The detection limit and precision were found to be 0.2 mg/L and 1.7 %, respectively. The interfering effect of high chloride contents was eliminated by precipitating chlorides with silver sulfate. The method was applied for the analysis of various water samples and beverages. The results were in good agreement with data from isotachophoretic and photometric measurements.     

Development and validation of an HPLC method for determination of ziprasidone and its impurities in pharmaceutical dosage forms

Ziprasidone is known as a novel "atypical" or "second-generation" antipsychotic drug. A sensitive and reproducible method was developed and validated for determination of ziprasidone and its major impurities, which are significantly different in polarity. The separation is performed on a Waters Spherisorb octadecylsilyl 1 column (5.0 microm particle size, 250 x 4.6 mm id) using a gradient with mobile phase A [buffer-acetonitrile (80+20, v/v)] and mobile phase B [buffer-acetonitrile (10+90, v/v)] at a working temperature of 25 degrees C. The buffer was 0.05 M KH2PO4 solution with an addition of 10 mL triethylamine/L solution, adjusted to pH 2.5 with orthophosphoric acid. The flow rate was 1.5 mL/min, and the eluate was monitored at 250 nm using a diode array detector. Optimization of the experimental conditions was performed using partial least squares regression, for which four factors were selected for optimization: buffer concentration, buffer pH, triethylamine concentration, and temperature. The proposed validated method is convenient and reliable for the assay and purity control in both raw materials and dosage forms.     

A Simple Synthesis of 5‐(2‐Aminophenyl)‐1H‐pyrazoles

A four‐step synthesis of 1‐substituted 5‐(2‐aminophenyl)‐1H‐pyrazoles 5 as a novel type of histamine analogs and versatile building blocks for further transformations was developed. The synthesis starts from commercially available 2‐nitroacetophenone ( 12 ), which is converted into the enamino ketone 13 as the key intermediate. Cyclization of the key intermediate 13 with monosubstituted hydrazines 14a – 14l afforded the 5‐(2‐nitrophenyl)‐1H‐pyrazoles 17a – 17l . Finally, catalytic hydrogenation of the nitro compounds 17a, 17c – 17e , and 17g – 17j furnished the title compounds 5a, 5c – 5e , and 5g – 5j , respectively, in good yields. As demonstrated by some further transformations, additional functionalization of compounds 17 and 5 is feasible, either by electrophilic substitution at C(4) of the pyrazole ring, or at the NH₂ group.     

Alcohols immobilization onto 2-chlorotritylchloride resin under microwave irradiation

The immobilization of alcohols onto 2-chlorotritylchloride resin using microwave irradiation was studied. Three different Fmoc-aminoalcohols were tested: the phenol-like Fmoc-tyramine, the primary alcohol Fmoc-ethanolamine, and the secondary alcohol Fmoc-4-hydroxypiperidine. Several reaction conditions were evaluated: different bases, reaction times, temperatures, and concentrations. Microwave immobilization resulted is effective in binding to the resin all three types of alcohols with loadings which were superior or comparable to the ‘classical’ methods in shorter time and without employing toxic and racemizing reagents. This method resulted also useful for the immobilization, through the hydroxyl group, of FmocTyrOAll, FmocSerOAll, and FmocThrOAll, important building blocks for the synthesis of cyclic peptides.     

Development and optimization of an HPLC analysis of citalopram and its four nonchiral impurities using experimental design methodology

In this study, the RP-HPLC method was investigated for the separation of citalopram and its four impurities by use of statistical experimental design. Initially, the influence of different experimental conditions (buffer pH, flow rate, and column temperature) on the chromatographic behavior of citalopram and its four impurities was investigated by use of partial least squares regression (PLSR) and multilayer perceptron (MLP) artificial neural networks (ANNs) trained by back-propagation. The developed models and the corresponding response surface plots were used to select the optimal HPLC conditions, buffer pH 7.0, flow rate 1.0 mL/ min, and column temperature 25 degrees C, for an efficient separation of citalopram and its four impurities. The elaborated HPLC method was found to be linear, specific, sensitive, precise, accurate, and robust. Retention times of citalopram and its impurities, obtained with the developed HPLC method, and the computed molecular parameters of the examined compounds were used in a quantitative structure retention relationship (QSRR) study. The PLSR and ANN algorithms were applied for the development of the QSRR methods. The MLP-two layers-ANN-QSRR model with root mean square error of prediction 0.105 and r(2) (observed versus predicted) 0.978 was selected. Since many different reaction conditions are applied for the synthesis of citalopram, different impurities and degradation products can be formed. Therefore, the developed QSRR model can be extended to the prediction of the retention times with the other citalopram impurities, degradation products, and metabolites.     

Electrophoretic and chromatographic evaluation of transgenic barley expressing a bacterial dihydrodipicolinate synthase

Nutritional quality of human and animal foodstuffs is determined by the content of essential amino acids. Barley is the fourth most important cereal of the world and the second most important cereal grown in the Czech Republic. Cereal grains such as barley contain insufficient levels of some essential amino acids, especially lysine. Dihydrodipicolinate synthase is the key enzyme involved in the regulatory step for lysine biosynthesis. Two constructs pBract214::sTPdapA and pBract214::mdapA containing the dapA gene from Escherichia coli coding for the bacterial dihydrodipicolinate synthase were used for transformation of barley. An Agrobacterium-mediated technique was used for transformation of immature embryos of spring barley cv. Golden Promise. Transgenic barley plants of the T0 and T1 generations were evaluated by PCR, real-time PCR, gel electrophoresis, and Western blot. Amino acid content was analyzed by HPLC after HCl hydrolysis. The lysine content in leaves of the T1 generation plant no. 5/5 was 50% higher than in wild-type plants; the lysine content in seeds of T2 generation plant no. 5/16 was 30% higher than in wild-type seeds of spring barley cv. Golden Promise.