João F. Cajaiba da Silva

Liquid phase benzylation of aromatic compounds with benzyl alcohol catalyzed by niobium phosphate

The catalytic activity of commercial niobium phosphate was evaluated in the benzylation of aromatic compounds with benzyl alcohol, in liquid phase. The conversion of benzyl alcohol was 100% in the reactions with toluene, ethylbenzene, propylbenzene and p-xylene while the highest selectivity in monobenzyl derived compounds (91%) was achieved with p-xylene. The formation of dibenzyl ether was also observed, indicating the presence of Bronsted acids sites in this type of catalyst.

A Simple Method Based on the Application of a CCD Camera as a Sensor to Detect Low Concentrations of Barium Sulfate in Suspension

The development of a simple, rapid and low cost method based on video image analysis and aimed at the detection of low concentrations of precipitated barium sulfate is described. The proposed system is basically composed of a webcam with a CCD sensor and a conventional dichroic lamp. For this purpose, software for processing and analyzing the digital images based on the RGB (Red, Green and Blue) color system was developed. The proposed method had shown very good repeatability and linearity and also presented higher sensitivity than the standard turbidimetric method. The developed method is presented as a simple alternative for future applications in the study of precipitations of inorganic salts and also for detecting the crystallization of organic compounds.

INTRA-TRIGONAL INJECTION OF BOTULINUM TOXIN A IN PATIENTS WITH BLADDER PAIN SYNDROME - RESULTS AT 9-MONTHS FOLLOW-UP

the number of associated conditions increased (i.e., localized, regional, to systemic), pain, stress, depression, and sleep disturbance increased while social support, sexual functioning and quality of life deteriorated. Anxiety and catastrophizing remained elevated in all groups. Symptom duration was associated with phenotypic progression. CONCLUSIONS: IC/PBS patients have significant biopsychosocial impairment compared to controls. IBS, FM and CFS are more prevalent in IC/PBS patients and result in significant impact. There is progression over time from an organ centric to regional and finally systemic pain syndrome with progression of symptom severity and deterioration of cognitive and psychosocial parameters associated with IC/PBS.

Design of Experiments on the Transesterification of tris(p-nitrophenyl) Phosphate with Sodium Methoxide

Abstract A design of experiments was conducted to study the transesterification of tris(p-nitrophenyl) phosphate with sodium methoxide. The factorial design was performed to check the experimental conditions that favored ths yield of bis(p-nitrophenyl) methyl phosphate in a semi-batch process. The experiments were performed using a Mettler RC1 calorimeter. The reaction temperature, the addition order of reagents and the time spent in those additions were analyzed at two different levels. The results showed the addition order of reagents as the most important factor to guarantee the improvement of the reaction yielding bis(p-nitrophenyl) methyl phosphate. It was demonstrated that the temperature has a small effect on the reaction yield between 5 and 30ˆC. An important effect was observed with regard to the addition time of reagents and yield: when the tris(p-nitrophenyl)phosphate is added to the methoxide solution (58% on average) while no effect was observed when the methoxide solution was added to the phosphate (87% on average). Theses results indicated that the addition could be made in times shorter than five minutes under the latter condition.

AB-INITIO CALCULATIONS OF 31P NMR CHEMICAL SHIFTS OF SUBSTITUTED ARYL DIALKYL PHOSPHATES

Abstract The experimental values of 31P NMR chemical shifts of dialkyl aryl phosphates were compared to the ab-inito calculated values. The consistence of the model that states the δ31P NMR chemical shift of phosphoric acid derivatives is mainly governed by symmetry of the electron cloud on the phosphorus atom that would, in turn, be related to the electronegativity of the substituent and the model suggesting the effect of “back bonding” from phosphoryl oxygen to phosphorus atom were both confirmed.

Skull base fracture involving the foramen spinosum - an indirect sign of middle meningeal artery lesion: case report and literature review.

Skull base fractures comprise a relatively common finding among trauma patients. Before the widespread use of computed tomography (CT), these lesions used to be misdiagnosed. Currently, with improved imaging technology, diagnosis of skull base fractures is no longer cumbersome. On the other hand, cranial fractures involving the foramen spinosum are rarely described in the literature. In this present article, we report on a patient affected by head trauma, who suffered from a vault fracture towards the foramen spinosum and acute epidural hematoma (EH) due to middle meningeal artery injury. We further discuss the clinical consequences of foramen spinosum fracture.

Real-Time Analysis to Evaluate Crystallization Processes

Crystallization is one of the most important unit operations employed by the pharmaceutical, microelectronics, food and fine chemicals industries for the production of solid products with high added value. This operation can be used as a method to perform separation and purification of crystalline compounds such as proteins, polymers, pharmaceuticals, inorganic salts, etc. (Fevotte & Klein, 1995; Feng & Berglund, 2002; Mersmann, 2001; Lewiner et al., 2001; Mullin, 2001; Liotta & Sabesan, 2004; Joung et al., 2005; Pelberg et al., 2005; Derdour et al., 2011).