Complex formation between Co-metalloporphyrin and silver colloid in acidic media

Large flower sized nanoparticles of silver were synthesized and hybrid colloids with porphyrins were obtained. Daisy-like round aggregates generated from triangular-shaped silver nanoparticles can be observed, evenly distributed. The complexation of these particles with organic dyes was the main purpose of this work in order to achieve nanomaterials exhibiting wide absorption bands. The formation of a complex between an acidified Co(II) 5,10,15,20-meso-tetra(3- hydroxyphenyl) porphyrin (Co-3OHPP) solution in THF and the silver colloid negatively charged at the surface was proven by analyzing the UV-vis spectra during the experiment

Detection of phosphine derivates using metalloporphyrins

Starting from the knowledge that phosphine derivatives exhibit medium/high toxicity, in this study we focused on the behavior of Co(II)- 5,10,15,20-tetratolyl-porphyrin (CoTTP) and Mn(III)-5,10,15,20-tetraphenyl-porphyrin chloride (MnTPPCl) as active UV-vis chromophores for the detection of triphenylphosphine oxide (LC50=12.2µg/mL, LC90=29.5µg/mL). The increase of triphenylphosphine oxide concentration generates the hypochromic effect on the Soret bands of the two metalloporphyrins. A comparison regarding the efficiency of the two metalloporphyrins in detecting phosphine derivatives was done

Noble metal colloid and Co-porphyrin hybrid sensitive to 4-aminosalicylic acid

A hybrid organic-inorganic nanomaterial (Co-3OHPP/n-Au) composed of Co(II) 5,10,15,20- meso-tetra(3-hydroxyphenyl)porphyrin (Co-3OHPP) and gold nanoparticles (n-Au) was tested as sensitive material for the optical detection of 4-aminosalicylic acid (PAS). This novel nanomaterial is able to detect 4-aminosalicylic acid in a reasonable concentration domain, covering one order of magnitude: 1.24 x 10-5 – 3.9 x 10-4M. The dependence between the intensity of absorption and the concentration in 4-aminosalicylic acid is linear, with a fair correlation coefficient of 95 %. This hybrid material can be further included in simple devices for the rapid and facile dosage of this antituberculosis drug in body fluids

Influence of CO2 upon UV-Vis spectroscopy of silica-tetra-3,4 dimethoxy-phenylporphyrin hybrid nanomaterial

A symmetrical substituted aryl porphyrin was incorporated by sol-gel method to generate a silica hybrid nanomaterial that preserves the UV-vis absorption properties of bare porphyrin. The novel hybrid demonstrated to be a sensitive material for CO2 detection. The sol-gel synthesis was monitored by UV-vis spectroscopy. Atomic force microscopy was performed for the hybrid before and after CO2 detection and important changes in the aggregation behavior of the nanomaterial were observed

Trace Oxygen Sensitive Material Based on Two Porphyrin Derivatives in a Heterodimeric Complex

The successful preparation of a novel dimer complex formed between 5,10,15,20-tetrakis(3,4-dimethoxyphenyl)-porphyrin Fe(III) chloride and (5,10,15,20-tetraphenylporphinato) dichlorophosphorus(V) chloride using the well-known reactivity of the P–X bond is reported. The obtained complex was characterized by UV-vis, Fourier transform infrared spectroscopy (FT-IR), fluorescence, 1H-NMR, 13C-NMR, and 31P-NMR spectroscopic techniques and also by additional Heteronuclear Single Quantum Coherence (HSQC) and Heteronuclear Multiple Bond Correlation (HMBC) experiments in order to correctly assign the NMR signals. Scanning electron microscopy (SEM) and EDX quantifications completed the characterizations. This novel porphyrin dimer complex demonstrated fluorescence sensing of H2O2 in water for low oxygen concentrations in the range of 40–90 µM proving medical relevance for early diagnosis of diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and even cancer because higher concentrations of H2O2 than 50 μM are consideredcytotoxic for life. Due to its optical properties, this novel metalloporphyrin–porphyrin based complex is expected to show PDT and bactericidal activity under visible-light irradiation

A Sensitive A3B Porphyrin Nanomaterial for CO2 Detection

The present report deals with the tailoring, preparation and characterization of novel nanomaterials sensitive to CO2 for use in detection of this gas during space habitation missions. A new nanostructured material based on mixed substituted asymmetrical A3B porphyrin: 5-(4-pyridyl)-10,15,20-tris(3,4-dimethoxyphenyl)-porphyrin (PyTDMeOPP) was synthesized and characterized by 1H-NMR, FT-IR, UV-vis, fluorescence, MS, HPLC and AFM. Introducing one pyridyl substituent in the 5-meso-position of porphyrin macrocycle confers some degree of hydrophilicity, which may cause self-assembly properties and a better response to increased acidity. The influence of pH and nature of the solvent upon H and J aggregates of the porphyrin are discussed. Porphyrin aggregation at the air–THF interface gave a triangular type morphology, randomly distributed but uniformly oriented. When deposition was made by multiple drop-casting operations, a network of triangles of uniform size was created and a porous structure was obtained, being reorganized finally in rings. When the deposition was made from CHCl3, ring structures ranging in internal diameter from 300 nm to 1 µm, but with the same width of the corona circular of approx. 200 nm were obtained. This porphyrin-based material, capable of generating ring aggregates in both THF and CHCl3, has been proven to be sensitive to CO2 detection. The dependence between the intensity of porphyrin UV-vis absorption and the concentration of CO2 has a good correlation of 98.4%

Competition on the University Educational Services Market in Romania and the Protection of Students’ Rights and Interests

This article aims to quantify the degree in which Romanian students’ rights and interests are protected. The authors have conducted a comparative analysis of a descriptive type of five representative university centres in Romania, followed by a quantitative research among students within these centres. Through an exploratory empirical research of a quantitative type, 438 students were interviewed, the results obtained determining the extent in which study programs pursued by respondents live up to student expectations and succeed to satisfy them. Student perception on the services offered in the five university centres considered were also quantified, having identified student intentions regarding their professional path, namely the extent in which there is a continuity between the job and the graduated field of study. Based on the results obtained, the authors recommend to the management of Romanian universities to develop efficient strategies that can afford the protection of students’ rights and interests, to permanently identify the needs of the actual and potential customers and to adapt the offer of educational services according to existing requirements on the labor market

Effect of Dietary Hemp Seed on Oxidative Status in Sows during Late Gestation and Lactation and Their Offspring

This study shows the antioxidant effect of a dietary hemp seed diet rich in ω-6 polyunsaturated fatty acid (PUFA) on oxidative status in sows during late gestation and lactation and their offspring. Ten pregnant sows were divided into two groups and fed either a control diet (CD) or a hemp diet (HD) containing 2% hemp seed meal for a period of 10 days before farrowing and 5% throughout the lactation period (21 d). After farrowing, 16 of their resulting piglets were divided into two groups: control group CD (eight piglets derived from control sows) and HD group (eight piglets derived from HD sows), respectively. Blood collected from sows and piglets at day 1, 7 and 21 was used for the measurement of antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), glutathione (GPx)), nitric oxide production (NO), lipid peroxidation (thiobarbituric acid reactive substances—TBARS), reactive oxygen species (ROS) generation and total antioxidant capacity (TAC) in plasma. The results showed a significant improvement in the oxidative status of sows fed HD throughout lactation compared with CD. Similarly, in piglets, HD positively influenced the activities of antioxidant enzymes, TAC and NO levels and significantly decreased lipid peroxidation in plasma until weaning, in comparison with the CD group. This study suggests the potential of hemp seed diet to improve the overall antioxidant status of the lactating sows and their progeny