For a special HTI molecule namely an omegaamino acid the ZE isomerization process occurs on a timescale of 30 ps

In the course of the reaction fast processes on the 1-10 ps timescale are observed which point to motions of the molecule on the potential-energy surface of the excited state. The combination of transient absorption experiments in the visible spectral range with time-resolved fluorescence and infrared measurements reveal a photochemical pathway with three intermediate states. Together with a theoretical modelling procedure the experiments point to a sequential reaction scheme and give indications of the nature of the involved intermediates.Implications of microbial enhanced oil recovery and waterflooding for geochemical interpretation of recovered oils.de Engenharia e Exploração de Petróleo (LENEP), Rodovia Amaral Peixoto, Km 163, Avenida Brennand, Imboassica, 27925-535 Macaé, RJ, Brazil.Athos da Silveira Ramos, 149, Ilha do Fundão, 21941-909 Rio de Janeiro, RJ, Chácaras de Recreio Samambaia, 74690-900 Goiânia, GO, Brazil.

Goiabeiras, 29075-910 Vitória, ES, Brazil.Pesquisas Químicas, Biológicas e Agrícolas (CPQBA), Avenida Alexandre Cazellato, 999, Paulínia/Betel, 13148-218 São Paulo, SP, Brazil.Biosurfactants and waterflooding have been widely reported thus far for enhancing oil production. Nevertheless, there is a lack of literature to explore enhanced oil recovered methods effects on its chemical composition. The aim of this work is to investigate the effects of a biosurfactant produced by Bacillus safensis and brine injection on the recovered petroleum composition, and their implications for geochemical interpretation. Original and oils recovered from displacement tests were analyzed by gas chromatography and ultra-high-resolution mass spectrometry, emphasizing saturated and aromatic biomarkers and basic and acidic polar compounds. Geochemical parameters based on some saturated compounds were subtly affected by the recovery methods, showing their reliable applicability in geochemical studies.

Contrarily, parameters based on some aromatic compounds were more affected by biosurfactant flooding, mostly the low molecular weight compounds. Thus, these aromatic parameters should be applied with caution after such methods. The distribution of basic and acidic polar compounds can also be modified affecting the geochemical interpretation. In the case of the basic ones, the biosurfactant greatly influenced the N class species with favorable loss of lower aromaticity compounds. In addition to water solubilization, the compositional changes described in this study can be related to fractionation due to adsorption on reservoir rocks.Toward pre-conceptual genetic analysis of human spermatozoa.Nuclei of mature mammalian spermatozoa are extraordinarily resistant to chemical and thermal injury.

Additionally, decondensation of spermatozoa DNA can be accompanied by little or no visual changes of the sperm head. This study tested whether human spermatozoa could be recovered following several cycles of primer extension preamplification (PEP) and used to achieve fertilization and subsequent development of human oocytes. An attempt was also made to amplify PEP buffer after spermatozoon removal. The results demonstrate that the sperm head can be successfully recovered following treatment with KOH or proteinase K followed by one to four cycles of PEP. It is also shown that following this treatment, the spermatozoa can be injected into the oocytes and will transform into a pronucleus if the oocyte is activated by sperm cytosolic fraction. In some cases, it was also possible to obtain polymerase chain reaction signals using a buffer after sperm cells were removed following several cycles of PEP. Although sperm participation in development was confirmed by fluorescence in-situ hybridization, light microscopy revealed some degree of damage to spermatozoal chromosomes.

It is concluded that pre-conceptual analysis of sperm cells may be possible, but more research is necessary to determine the optimal conditions that would preserve sperm DNA integrity while allowing accurate Photopolymerized water-soluble maleilated chitosan/methacrylated poly (vinyl alcohol) hydrogels as potential tissue engineering scaffolds.Functional Textiles of New Textile Materials, Ministry of Education, Wuhan Functional Textiles of New Textile Materials, Ministry of Education, Wuhan Photocrosslinkable water-soluble maleilated chitosan and methacrylated poly (vinyl alcohol) were synthesized and therefore maleilated chitosan/methacrylated poly (vinyl alcohol) (MCS/MPVA) hydrogels were prepared under UV radiation. Photolyzable Acid Precursor of properties of the hydrogels including rheological property, swelling behavior, morphology and mechanical test were investigated. The main results showed that the MCS/MPVA hydrogels had fast gel-forming rate (complete transformation to gel within 150s), improved compressive strength at 069±011MPa and rapid absorbent capacity. These behaviors could be tunable via the control of weight ratio of MCS to MPVA.