Tautomeric Equilibria Studies by Mass Spectrometry

Tautomerism in organic chemistry has been extensively studied in condensed phase by spectrometric methods, mainly by IR and NMR techniques. Mass spectrometry studies start 40 years ago but just recently it has been recognized the importance of the mass spectral data for the study of tautomerism in the gas phase.
Mass spectrometry can provide valuable information in regard to tautomeric equilibria when studying mass spectra among the members of different families of organic compounds.
The relevance of the mass spectral data resides on several facts but there are two that are of key importance:
1-	Mass spectral fragmentation assignments should be tautomer specific since the corresponding abundances ratios are supposed to be correlated to the keto/enol contents.
2-	Ionization in the ion source is supposed to have no effect on the position of the equilibrium so that the results reflect the tautomers content in the gas phase previous to ionization.
Some of the carbonylic compounds do not exhibit noticeable tautomerism so the fragment abundances assigned to the enol form is very low or not measurable. Since enolization is more noticeable in the case of thio-derivatives (which correlates adequately with the oxygenated analogues), the study of their mass spectra is an interesting choice to reach some degree of generalization. 
In addition, experimental findings are supported by semiempirical theoretical calculations, which probed to be adequate not only for supporting tendency correlations among the members of a compound family but also to calculate heats of tautomerization in gas phase.
Reports using mass spectrometry for tautomerism are becoming less common. One of the reasons is that now it would appear that the interpretation of MS results is not as straightforward as it was once believed, even though in a recent review it was written that: “Mass spectrometry is the most informative and practical method for studying and identifying tautomers in the gas phase” [1]. 
In fact, mass spectrometry seems to be very informative for studying and identifying tautomers, because in this case external factors like solvents, intermolecular interactions, etc., can be excluded by transferring the tautomeric system into gas phase, where the process becomes truly unimolecular [1].
This review covers the study of Tautomerism by Mass Spectrometry in the last four decades. 
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Carrapato e vermes: inimigos do gado e do produtor.

bitstream/item/65290/1/CT-95-Carrapato-e-vermes.pd

Películas a base de proteínas de salvado de arroz enriquecidas por el extracto fenólico de salvado de arroz fermentado y por la arcilla montmorillonítica

Proteins extracted from rice bran were used to prepare bio-base films where a factorial experimental design was performed in order to evaluate the effect of protein and glycerol concentrations, and the addition of phenolic extract and montmorillonite (MMT) clay on their physicochemical properties. The phenolic extract was obtained from fermentation of rice bran in solid state with the fungus Rhizopus oryzae. Results showed that protein concentration affected (p < 0.05) the luminosity, opacity and solubility of the films. An increase of glycerol concentration strongly affects (p < 0.05) the values of mechanical properties and water vapor permeability of the films. The addition of phenolic extract to the films affected (p < 0.05) opacity, tensile strength, elongation, Youngs modulus and water vapor permeability, while addition of MMT decreased (p < 0.05) the mechanical properties of the films. Films presented solubility values of less than 25%, luminosity above 80 (L*), opacity above 14%, tensile strength of 8.6 MPa, elongation of 70%, elasticity above 600 MPa and water vapor permeability of 7.5 g.mm/d.m2.kPa. These results show that rice bran protein can be used in the production of bio-based films to further use in food applications.Con el fin de evaluar el efecto que sobre las propiedades fisicoquímicas de las proteínas extraídas del salvado de arroz tienen distintas concentraciones de proteína y de glicerol, así como la adición de extracto fenólico y de arcilla montmorillonítica, las mismas se utilizaron para preparar películas de base biológica en el marco de un diseño experimental factorial. Mediante la fermentación de salvado de arroz en estado sólido con el hongo Rhizopus oryzae, se obtuvo el extracto fenólico. Los resultados demuestran que la concentración proteica afectó significativamente (p < 0,05) la luminosidad, la opacidad y la solubilidad de las películas. Asimismo, un aumento de la concentración de glicerina afectó fuertemente (p < 0,05) los valores de las propiedades mecánicas y de la permeabilidad al vapor de agua de las mismas. La adición de extracto fenólico a las películas afectó de manera significativa (p < 0,05) la opacidad, la fuerza de tensión, el alargamiento, el módulo de Young y la permeabilidad al vapor de agua, mientras que la adición de montmorillonita disminuyó (p < 0,05) sus propiedades mecánicas. Se constató que las películas mostraron valores de solubilidad inferiores a 25%, de luminosidad superiores a 80 (L*), de opacidad superiores a 14%, de fuerza de tensión de 8,6 MPa, de alargamiento de 70%, de elasticidad superiores a 600 MPa y de permeabilidad al vapor de agua de 7,5 g.mm/d.m2 .kPa. Estos resultados demuestran que, en el ámbito de los alimentos, la proteína de salvado de arroz puede utilizarse para la producción de películas de base biológica con el fin de adjudicarle usos adicionales.Authors Cristiano G. Schmidt and Miguel A. Cerqueira are thankful to Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brazil; BEX 9730/11-7) and Fundacao para a Ciencia e Tecnologia, POPH-QREN and FSE (FCT, Portugal) (SFRH/BPD/72753/2010) for financial support. The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF.NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON. 2 - O Novo Norte), QREN, FEDER

Reconnaissance of Pharmaceutical Chemicals in Urban Streams of the Tualatin River Basin, Oregon, 2002

A reconnaissance of pharmaceutical chemicals in urban streams of the Tualatin River basin was conducted in July 2002 in an effort to better understand the occurrence and distribution of such compounds, and to determine whether they might be useful indicators of human-related stream contamination. Of the 21 pharmaceutical chemicals and metabolites tested, only 6 (acetaminophen, caffeine, carbamazepine, codeine, cotinine, and sulfamethoxazole) were detected in filtered stream samples from 10 sites. The concentrations of most of the detected compounds were relatively low (less than 0.05 microgram per liter). The most frequently detected compounds were cotinine (a nicotine metabolite, 8 of 10 samples) and caffeine (a stimulant, 7 of 10 samples). More compounds were detected in urban stream samples than in samples from forested or agricultural drainages. Filtered water samples also were collected from four locations within an advanced wastewater treatment facility to quantify the relative amounts of these chemicals in a municipal waste stream and to determine the degree to which those chemicals are removed by treatment processes. Fifteen pharmaceutical chemicals or metabolites were detected in wastewater treatment facility influent, with concentrations far exceeding those measured in streams. Only five of those compounds, however, were detected in the treated effluent (carbamazepine, cotinine, ibuprofen, metformin, and sulfamethoxazole) and most of those were at concentrations less than 0.2 microgram per liter. The target pharmaceutical chemicals and metabolites showed limited potential for use as tracers of specific types of human-related contamination in Tualatin River basin streams because of widespread sources (caffeine, for example) or extremely low concentrations. Caffeine and cotinine are likely to be good indicators of sources that can occur in urban areas, such as sewage spills or leaks or the widespread use and careless disposal of tobacco products and caffeine-containing beverages. Neither compound, however, is likely to be a good tracer for a specific source unless that source is large. The presence of 1,7-dimethylxanthine (a caffeine metabolite) concurrently with caffeine might indicate the presence of untreated wastewater; in contrast, the absence of the metabolite might help rule out that source. Acetaminophen might make a good tracer for untreated wastewater because of its common usage, high concentration in raw wastewater, and effective removal via treatment. Carbamazepine and sulfamethoxazole have the potential to be good indicators of treated wastewater because of their incomplete removal in treatment facilities. Some of these pharmaceutical chemicals, either singly or in combination, might prove useful as tracers of contamination after further study

Carrapato dos bovinos: controle estratégico nas diferentes regiões brasileiras.

bitstream/item/65401/1/COT-36-Carrapato-dos-bovinos.pd

An immunohistochemical assessment of cellular proliferation markers in head and neck squamous cell cancers.

Prognostic information is essential for the evaluation, judgement and optimal treatment of patients with squamous cell cancers (SCCs) of the upper aerodigestive tract. Using immunohistochemical and flow cytometric techniques, we have studied the significance of cellular expression of the Ki-67 antigen, epidermal growth factor receptor (EGFR), the transferrin receptor (TFR) and DNA ploidy status in a prospective analysis of patients with SCCs of the head and neck region. All 42 fresh tumour samples (five well differentiated; 28 moderately differentiated; nine poorly differentiated) expressed both EGFR and TFR to varying degrees. Receptor expression was most marked on the peripheral invading margin of cancer cell islands although staining was also demonstrated in a random fashion within cellular islands and consistently along the basal cell layer of overlying stratified squamous epithelium. The percentage of cancer cells that reacted with the Ki-67 monoclonal antibody was assessed as low (less than 10%) in 15 samples (35.8%), intermediate (10-30%) in 19 samples (45.2%) and high (greater than 30%) in eight samples (19.0%). Eleven of 15 samples (73%) with a low percentage reactivity were DNA diploid, whereas seven of eight samples (87.5%) with a high percentage reactivity were DNA aneuploid. Poorly differentiated SCCs were significantly more often aneuploid than were either moderately or well differentiated tumours. Our results suggest that EGFR and TFR are widely distributed on SCCs, especially on proliferating cells at the invading tumour margin. In addition, there is a close spatial correlation between cells expressing EGFR, TFR and those expressing the Ki-67 antigen. Tumours in which the staining intensity for both EGFR and TFR was intense invariably expressed the Ki-67 antigen in a high proportion of cells. Further patient follow-up will be important in determining whether intense EGFR and TFR staining, combined with a high percentage reactivity with Ki-67 antibody and DNA aneuploidy, will ultimately define a subset of head and neck cancer patients with a poor clinical outcome

Negotiating sacred roles:a sociological exploration of priests who are mothers

In 1992, in a historic move, the Church of England voted to allow women's ordination to priesthood and in 1994 the first women priests started to be ordained. Despite much research interest, the experiences of priests who are mothers to dependent children have been minimally investigated. Based on in-depth interviews with seventeen mothers ordained in the Church, this paper will focus on how the sacred-profane boundary is managed. Priests who are mothers have a particular insight into the Church hierarchy as they symbolically straddle the competing discourses of sacred and profane. However, instead of reifying these binaries, the experiences of these women show how such dualisms are challenged and managed in everyday life. Indeed, in terms of experience, ritual, ministry and preaching, priests who are mothers are resisting, recasting and renegotiating sacred terrain in subtle and nuanced ways. Mothers thus not only negotiate the practical and sacramental demands placed on priests, but also illuminate how the sacred domain is regulated and constructed

Multi-Modal Active Perception for Autonomously Selecting Landing Sites on Icy Moons

Selecting suitable landing sites is fundamental to achieving many mission objectives in planetary robotic lander missions. However, due to sensing limitations, landing sites which are both safe and scientifically valuable often cannot be determined reliably from orbit, particularly, in icy moon missions where orbital sensing data is noisy and incomplete. This paper presents an active perception approach to Entry Descent and Landing (EDL) which enables the lander to autonomously plan informative descent trajectories, acquire high quality sensing data during descent and exploit this additional information to select higher utility landing sites. Our approach consists of two components: probabilistic modeling of landing site features and approximate trajectory planning using a sampling based planner. The proposed framework allows the lander to plan long horizons paths and remain robust to noisy data. Results in simulated environments show large performance improvements over alternative approaches and show promise that our approach has strong potential to improve science return of not only icy moon missions but EDL systems in general