Chemical constituents and antifungal potential of Attalea geraensis Barb. Rodr. (Arecaceae) palm leaves, a species native to the Cerrado of Brazil.

Fungal diseases, especially those that affect the root systems of plants, caused by Rhizoctonia and Macrophomina are limiting factors for achieving high crop yields. Alternatives to controlling fungi with chemical products drive the search for new options for bioactive compounds from plants. Attalea geraensis, a palm tree from the Brazilian Cerrado, is rich in flavonoids with antifungal actions. The objective of this work is to identify the chemical classes present in the ethanolic extract of green leaves of A. geraensis and determine the antifungal potential of the extract against isolates of Macrophomina phaseolina (Tassi) Goid. and Rhizoctonia solani JG Kühn. Phytochemical prospection, flavonoid dereplication, and antifungal activity were carried out of the ethanolic extract of the green leaves of A. geraensis harvested in the Cerrado area of Brazil. Steroids, triterpenes, saponins, and anthraquinones are described here for the first time for the leaves of A. geraensis. The flavonoids quercetin, isorhamnetin, 3,7-dimethylquercetin, quercetin 3-galactoside, 5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenyl)-3-{[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-4H-chromen-4-one, rhamnazin 3-galactoside, keioside, and rhamnazin 3-rutinoside were identified. Of these, only quercetin and isorhamnetin had already been identified in the leaves of A. geraensis. The results show a fungistatic potential for the species. The diversity of flavonoids present in the leaves of A. geraensis may be the result of a synergistic action between fungus and plant or there could be an antagonistic effect between flavonoids and the other identified chemical classes.

Oncideres saga Dalman: first record damaging Stryphnodendron adstringens Mart. Coville (Fabaceae) in Brazil / Oncideres saga Dalman: primeiro registro em Stryphnodendron adstringens Mart. Coville (Fabaceae) no Brasil

Oncideres females girdle tree branches of the Fabaceae family, interrupting the sap flow and turning the wood conditions ideal for their larvae development. The bark of Stryphnodendron adstringens (Mart.) Coville, a species native to the Brazilian Cerrado, is widely used in the traditional medicine. The objectives were to report, for the first time, Oncideres saga (Dalman), using S. adstringens as a host and to describe the pattern of branch girdling and oviposition distribution by this insect on these branches. The diameter at the base and the length of the girdled branches were measured and the number of incisions made by the O. saga females to oviposit, per branch section (basal, median and apical), counted. The emerged specimens were counted and the diameter of the exit holes measured. The average diameter at the base of the girdled branches was 2.5 ± 0.16 cm and the length was 90.6 ± 4.6 cm. The average number of incisions per branch was 37.7 ± 2.7. Damage by O. saga can reduce the growth and cause losses on S. adstringens, a tree with great extractivism potential.

As fêmeas de Oncideres anelam galhos de árvores da família Fabaceae, interrompendo o fluxo de seiva, tornando a madeira ideal para o desenvolvimento de suas larvas. A casca de Stryphnodendron adstringens (Mart.) Coville uma espécie nativa do cerrado brasileiro, é amplamente utilizada na medicina tradicional. Os objetivos foram relatar, pela primeira vez, Oncideres saga (Dalman), usando S. adstringens como hospedeiro e descrever o padrão dos galhos anelados e a distribuição das posturas desse inseto. O diâmetro na base e o comprimento dos galhos anelados foram medidos e o número de incisões feitas pelas fêmeas por seção do galho (basal, mediana e apical) quantificados. Os espécimes emergidos foram contados e o diâmetro dos orifícios de emergência medidos. O diâmetro médio, dos galhos anelados, na base foi de 2,58 ± 0,16 cm e o comprimento de 90,6 ± 4,6 cm. O número médio de posturas por galho foi 37,7 ± 2,7. Danos por O. saga podem reduzir o crescimento e causar perdas em S. adstringens, árvore com grande potencial extrativista.

Oncideres saga Dalman: first record damaging Stryphnodendron adstringens Mart. Coville (Fabaceae) in Brazil

Abstract Oncideres females girdle tree branches of the Fabaceae family, interrupting the sap flow and turning the wood conditions ideal for their larvae development. The bark of Stryphnodendron adstringens (Mart.) Coville, a species native to the Brazilian Cerrado, is widely used in the traditional medicine. The objectives were to report, for the first time, Oncideres saga (Dalman), using S. adstringens as a host and to describe the pattern of branch girdling and oviposition distribution by this insect on these branches. The diameter at the base and the length of the girdled branches were measured and the number of incisions made by the O. saga females to oviposit, per branch section (basal, median and apical), counted. The emerged specimens were counted and the diameter of the exit holes measured. The average diameter at the base of the girdled branches was 2.5 ± 0.16 cm and the length was 90.6 ± 4.6 cm. The average number of incisions per branch was 37.7 ± 2.7. Damage by O. saga can reduce the growth and cause losses on S. adstringens, a tree with great extractivism potential.,

Resumo As fêmeas de Oncideres anelam galhos de árvores da família Fabaceae, interrompendo o fluxo de seiva, tornando a madeira ideal para o desenvolvimento de suas larvas. A casca de Stryphnodendron adstringens (Mart.) Coville uma espécie nativa do cerrado brasileiro, é amplamente utilizada na medicina tradicional. Os objetivos foram relatar, pela primeira vez, Oncideres saga (Dalman), usando S. adstringens como hospedeiro e descrever o padrão dos galhos anelados e a distribuição das posturas desse inseto. O diâmetro na base e o comprimento dos galhos anelados foram medidos e o número de incisões feitas pelas fêmeas por seção do galho (basal, mediana e apical) quantificados. Os espécimes emergidos foram contados e o diâmetro dos orifícios de emergência medidos. O diâmetro médio, dos galhos anelados, na base foi de 2,58 ± 0,16 cm e o comprimento de 90,6 ± 4,6 cm. O número médio de posturas por galho foi 37,7 ± 2,7. Danos por O. saga podem reduzir o crescimento e causar perdas em S. adstringens, árvore com grande potencial extrativista.

Oncideres saga Dalman: first record damaging Stryphnodendron adstringens Mart. Coville (Fabaceae) in Brazil / Oncideres saga Dalman: primeiro registro em Stryphnodendron adstringens Mart. Coville (Fabaceae) no Brasil

Oncideres females girdle tree branches of the Fabaceae family, interrupting the sap flow and turning the wood conditions ideal for their larvae development. The bark of Stryphnodendron adstringens (Mart.) Coville, a species native to the Brazilian Cerrado, is widely used in the traditional medicine. The objectives were to report, for the first time, Oncideres saga (Dalman), using S. adstringens as a host and to describe the pattern of branch girdling and oviposition distribution by this insect on these branches. The diameter at the base and the length of the girdled branches were measured and the number of incisions made by the O. saga females to oviposit, per branch section (basal, median and apical), counted. The emerged specimens were counted and the diameter of the exit holes measured. The average diameter at the base of the girdled branches was 2.5 ± 0.16 cm and the length was 90.6 ± 4.6 cm. The average number of incisions per branch was 37.7 ± 2.7. Damage by O. saga can reduce the growth and cause losses on S. adstringens, a tree with great extractivism potential.

As fêmeas de Oncideres anelam galhos de árvores da família Fabaceae, interrompendo o fluxo de seiva, tornando a madeira ideal para o desenvolvimento de suas larvas. A casca de Stryphnodendron adstringens (Mart.) Coville uma espécie nativa do cerrado brasileiro, é amplamente utilizada na medicina tradicional. Os objetivos foram relatar, pela primeira vez, Oncideres saga (Dalman), usando S. adstringens como hospedeiro e descrever o padrão dos galhos anelados e a distribuição das posturas desse inseto. O diâmetro na base e o comprimento dos galhos anelados foram medidos e o número de incisões feitas pelas fêmeas por seção do galho (basal, mediana e apical) quantificados. Os espécimes emergidos foram contados e o diâmetro dos orifícios de emergência medidos. O diâmetro médio, dos galhos anelados, na base foi de 2,58 ± 0,16 cm e o comprimento de 90,6 ± 4,6 cm. O número médio de posturas por galho foi 37,7 ± 2,7. Danos por O. saga podem reduzir o crescimento e causar perdas em S. adstringens, árvore com grande potencial extrativista.

What is the frequency of floor of the mouth lesions? A descritive study of 4,016 cases.

BACKGROUND: The aim of this study was to investigate the frequency of oral lesions in the floor of the mouth from representative oral pathology centres in Latin America. MATERIAL AND METHODS: This study was conducted on biopsies obtained from January of 1978 to December of 2018 at nine Latin America oral and maxillofacial pathology centres. Gender, age and histopathological diagnosis were evaluated. Data were analysed using descriptive methods. Chi-square test was used for pairwise comparisons. RESULTS: From 114,893 samples, 4,016 lesions (3.49%) occurred in the floor of the mouth. Brazil showed 3,777 cases (94%), Mexico 182 cases (4.5%) and Argentina 57 cases (1.4%). Benign lesions represented 65.1% (2,617 cases), followed by 34.9% (1,404 cases) of malignant disorders. Lesions of epithelial origin were more frequent (1,964 cases; 48.9%), followed by salivary glands (1,245 cases; 31%) and soft tissue lesions (475 cases; 11.7%). The most common histological subtypes were oral squamous cell carcinoma (1,347 cases; 33.5%), ranula (724 cases; 18%), oral leukoplakia (476 cases; 11.8%) and inflammatory fibrous hyperplasia (239 cases; 5.9%). The lesion affected males in 2,129 cases and females in 1,897 cases. CONCLUSIONS: In the current study, lesions in the floor of the mouth represented 3.49% of biopsies submitted to oral pathology services and oral squamous cell carcinoma, ranula and leukoplakia were the most common lesions.

Oncideres saga Dalman: first record damaging Stryphnodendron adstringens Mart. Coville (Fabaceae) in Brazil.

Oncideres females girdle tree branches of the Fabaceae family, interrupting the sap flow and turning the wood conditions ideal for their larvae development. The bark of Stryphnodendron adstringens (Mart.) Coville, a species native to the Brazilian Cerrado, is widely used in the traditional medicine. The objectives were to report, for the first time, Oncideres saga (Dalman), using S. adstringens as a host and to describe the pattern of branch girdling and oviposition distribution by this insect on these branches. The diameter at the base and the length of the girdled branches were measured and the number of incisions made by the O. saga females to oviposit, per branch section (basal, median and apical), counted. The emerged specimens were counted and the diameter of the exit holes measured. The average diameter at the base of the girdled branches was 2.5 ± 0.16 cm and the length was 90.6 ± 4.6 cm. The average number of incisions per branch was 37.7 ± 2.7. Damage by O. saga can reduce the growth and cause losses on S. adstringens, a tree with great extractivism potential.

Malignant transformation of oral leukoplakia: a multicentric retrospective study in Brazilian population.

BACKGROUND: Among the oral potentially malignant disorders, leukoplakia stands out as the most prevalent. The purpose of this study was to analyse the clinical-pathological features of oral leukoplakia in groups of patients from three major pathology centers in two different regions of Brazil, in order to determine which factors would be associated to the clinical risk of malignant transformation. MATERIAL AND METHODS: A total of 148 patients was analyzed, and data regarding gender, age, site, classification of the clinical subtype, harmful habits such as use of tobacco and alcohol, time of evolution and presence of dysplasia were collected. The association between risk factors and malignant transformation was investigated using the chi-square test and Fischer's exact test for correlation of variables. A significance level of 5% (p≤0.05) was used. RESULTS: The mean age of the patients was 60 years, and 56% were female. Most of the lesions (34,5%) were located in the lateral and ventral regions of the tongue. Of the 148 patients, ninety had clinical follow-up. Malignant transformation occurred in 13 patients (8.8%), with an average of 44 months of follow up. CONCLUSIONS: Non-smoker, nonhomogeneous clinical presentation, location at the tongue, and the presence of high degree of dysplasia were statistically relevant factors associated with a higher risk of transformation transformation.

Rose Bengal incorporated to α-cyclodextrin microparticles for photodynamic therapy against the cariogenic microorganism Streptococcus mutans.

Rose Bengal@α-cyclodextrin (RB@α-CD) microparticles (µPs) were prepared and the RB inclusion in α-CD was experimentally demonstrated through infrared, UV-VIS absorption spectroscopy and cyclic voltammetry. The RB inclusion in α-CD was theoretically investigated using classical molecular mechanics calculations, the simulation results showing that RB can be included in both the narrow and wide apertures of the α-cyclodextrin ring with configurations exhibiting average binding energies of about 27 kcal mol-1. The prepared RB@α-CD microparticles were characterized through Scanning Electron Microscopy (SEM) and it was demonstrated that they are highly efficient in the photodynamic therapy against a Streptococcus mutans (the main bacteria of cariogenic dental plaque) suspension, as a concentration of RB@α-CD µPs 10 times smaller than the usual concentration of pure RB is still capable to produce significant antibacterial activity.

An ab initio investigation for elastic and electronically inelastic electron scattering from para-benzoquinone.

We report the results of ab initio calculations for elastic scattering and also for excitation of individual electronic states of para-benzoquinone (pBQ) by the impact of low-energy electrons. The calculations for elastic scattering were performed with the Schwinger multichannel method implemented with pseudopotentials (SMCPP) in the static-exchange (SE) plus polarization (SEP) approximation for energies up to 50 eV. The assignments for the resonance spectrum obtained in this study are, in general, in good agreement with previous results available in the literature. For electronic excitation by electron impact, the SMCPP method with N energetically open electronic states (N open ), at either the static-exchange (N open ch-SE) or the static-exchange-plus-polarisation (N open ch-SEP) approximation, was employed to calculate the scattering amplitudes using a channel coupling scheme that ranges from the 1ch-SEP up to the 89ch-SE level of approximation, depending on the energy of interest. Integral cross sections (ICSs) and differential cross sections (DCSs) were obtained for incident electron energies lying between 15 eV and 50 eV. The study focuses on the influence of multichannel coupling effects for electronically inelastic processes, more specifically, on how the number of excited states included in the open-channel space impacts upon the convergence of the cross sections at intermediate and higher energies. In particular, we found that the magnitude of DCS and ICS results for electronic excitation decreases as more channels are included in the calculations. To the best of our knowledge, there are no other experimental or theoretical ICS or DCS results for excitation into individual electronic states of pBQ available in the literature between 15 and 50 eV against which we might compare the present calculations.

Total electron scattering cross sections from para-benzoquinone in the energy range 1-200 eV.

Total electron scattering cross sections, from para-benzoquinone, for impact energies ranging between 1 to 200 eV, have been obtained by measuring the attenuation of a linear electron beam under magnetic confinement conditions. Random uncertainty limits on these values have been found to be within 5%. Systematic errors, due to the axial magnetic beam conditions in combination with the acceptance angle of the detector, have been evaluated by integrating our calculated independent atom model with the screening corrected additivity rule and interference term elastic differential cross sections over that detection acceptance angle. Our previous calculations and measurements on this molecule (Jones et al., J. Chem. Phys., 2018, 148, 124312 and J. Chem. Phys., 2018, 148, 204305), have been compiled and complemented with new elastic and inelastic scattering cross section calculations in order to obtain a comprehensive cross section data base, within the considered energy range, for modelling purposes. The self-consistency of the present data set has been evaluated by simulating the electron transport of 15 eV electrons in para-benzoquinone, and comparing those results with the observed transmitted intensity distribution.

Integral elastic, vibrational-excitation, electronic-state excitation, ionization, and total cross sections for electron scattering from para-benzoquinone.

We report absolute experimental integral cross sections (ICSs) for the electron impact excitation of 6 bands (Bands 0-V) of unresolved electronic-states in para-benzoquinone, for incident electron energies between 20 and 40 eV. Absolute vibrational-excitation ICSs, for 3 composite vibrational bands (Bands I-III), are also reported in that same energy range. In addition, ICSs calculated within our independent atom model (IAM) with screening corrected additivity rule (SCAR) formalism, extended to account for interference (I) terms that arise due to the multi-centre nature of the scattering problem, are also reported. The sum of those ICSs gives the IAM-SCAR+I total cross section (TCS) for electron-para-benzoquinone scattering. Where possible, those calculated IAM-SCAR+I ICSs are compared against corresponding results from the present measurements with an acceptable level of accord being obtained. Similarly, we also present results from our Schwinger multichannel method with pseudopotential (SMCPP) calculations. Here elastic ICSs and ICSs corresponding to the Bands 0-III of unresolved electronic-states are presented, with agreement between the SMCPP electronic-state ICSs and those from our measurements being in good qualitative accord. The energy range of our SMCPP computations is 16-50 eV. Using the binary-encounter-Bethe (BEB) approach, total ionization cross sections for this collision system were computed. Those total ionization cross sections were then added to our SMCPP ICS results, to derive SMCPP/BEB TCSs that are typically in very good accord with those from our IAM-SCAR+I approach.

Electron-impact electronic-state excitation of para-benzoquinone.

Angle resolved electron energy loss spectra (EELS) for para-benzoquinone (C6H4O2) have been recorded for incident electron energies of 20, 30, and 40 eV. Measured differential cross sections (DCSs) for electronic band features, composed of a combination of energetically unresolved electronic states, are subsequently derived from those EELS. Where possible, the obtained DCSs are compared with those calculated using the Schwinger multichannel method with pseudopotentials. These calculations were performed using a minimum orbital basis single configuration interaction framework at the static exchange plus polarisation level. Here, quite reasonable agreement between the experimental cross sections and the theoretical cross sections for the summation of unresolved states was observed.

Economic selection indexes for Hereford and Braford cattle raised in southern Brazil.

Economic selection indexes (EI) are considered the best way to select the most profitable animals for specific production systems. Nevertheless, in Brazil, few genetic evaluation programs deliver such indexes to their breeders. The aims of this study were to determine the breeding goals (BG) and economic values (EV, in US$) for typical beef cattle production systems in southern Brazil, to propose EI aimed to maximize profitability, and to compare the proposed EI with the currently used empirical index. Bioeconomic models were developed to characterize 3 typical production systems, identifying traits of economic impact and their respective EV. The first was called the calf-crop system and included the birth rate (BR), direct weaning weight (WWd), and mature cow weight (MCW) as selection goals. The second system was called the full-cycle system, and its breeding goals were BR, WWd, MCW, and carcass weight (CW). Finally, the third was called the stocking and finishing system, which had WWd and CW as breeding goals. To generate the EI, we adopted the selection criteria currently measured and used in the empirical index of PampaPlus, which is the genetic evaluation program of the Brazilian Hereford and Braford Association. The comparison between the EI and the current PampaPlus index was made by the aggregated genetic-economic gain per generation (Δ). Therefore, for each production system an index was developed using the derived economic weights, and it was compared with the current empirical index. The relative importance (RI) for BR, WWd, and MCW for the calf-crop system was 68.03%, 19.35%, and 12.62%, respectively. For the full-cycle system, the RI for BR, WWd, MCW, and CW were 69.63%, 7.31%, 5.01%, and 18.06%, respectively. For the stocking and finishing production system, the RI for WWd and CW was 34.20% and 65.80%, respectively. The Δ for the calf-crop system were US$6.12 and US$4.36, using the proposed economic and empirical indexes, respectively. Respective values were US$19.87 and US$18.22 for the full-cycle system and US$20.52 and US$18.52 in the stocking and finishing system. The efficiency of the proposed EI had low sensitivity to changes in the values of the economic and genetic parameters. The 3 EI generated higher Δ when using the proposed economic weight compared to the Δ provided by a PampaPlus index, suggesting the use of proposed EI to obtain greater economic profitability in relation to the current empirical PampaPlus index.

Elastic scattering and vibrational excitation for electron impact on para-benzoquinone.

We report on theoretical elastic and experimental vibrational-excitation differential cross sections (DCSs) for electron scattering from para-benzoquinone (C6H4O2), in the intermediate energy range 15-50 eV. The calculations were conducted with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that also now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (Nopen) at the static-exchange-plus-polarisation (Nopench-SEP) level was used to calculate the scattering amplitudes using a channel coupling scheme that ranges from 1ch-SE up to the 89ch-SEP level of approximation. We found that in going from the 38ch-SEP to the 89ch-SEP, at all energies considered here, the elastic DCSs did not change significantly in terms of both their shapes and magnitudes. This is a good indication that our SMCPP 89ch-SEP elastic DCSs are converged with respect to the multichannel coupling effect for the investigated intermediate energies. While agreement between our IAM-SCAR+I and SMCPP 89ch-SEP computations improves as the incident electron energy increases from 15 eV, overall the level of accord is only marginal. This is particularly true at middle scattering angles, suggesting that our SCAR and interference corrections are failing somewhat for this molecule below 50 eV. We also report experimental DCS results, using a crossed-beam apparatus, for excitation of some of the unresolved ("hybrid") vibrational quanta (bands I-III) of para-benzoquinone. Those data were derived from electron energy loss spectra that were measured over a scattered electron angular range of 10°-90° and put on an absolute scale using our elastic SMCPP 89ch-SEP DCS results. The energy resolution of our measurements was ∼80 meV, which is why, at least in part, the observed vibrational features were only partially resolved. To the best of our knowledge, there are no other experimental or theoretical vibrational excitation results against which we might compare the present measurements.

Theoretical and experimental differential cross sections for electron impact excitation of the electronic bands of furfural.

We report results from a joint experimental and theoretical investigation into electron scattering from the important industrial species furfural (C5H4O2). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of C5H4O2. The measurements were carried out at energies in the range 20-40 eV, and for scattered-electron angles between 10° and 90°. The energy resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potential calculations, for energies between 6-50 eV and with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were undertaken at the static exchange plus polarisation-level using a minimum orbital basis for single configuration interaction (MOB-SCI) approach. Agreement between the measured and calculated DCSs was qualitatively quite good, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOB-SCI. The role of multichannel coupling on the computed electronic-state DCSs is also explored in some detail.

Integral elastic, electronic-state, ionization, and total cross sections for electron scattering with furfural.

We report absolute experimental integral cross sections (ICSs) for electron impact excitation of bands of electronic-states in furfural, for incident electron energies in the range 20-250 eV. Wherever possible, those results are compared to corresponding excitation cross sections in the structurally similar species furan, as previously reported by da Costa et al. [Phys. Rev. A 85, 062706 (2012)] and Regeta and Allan [Phys. Rev. A 91, 012707 (2015)]. Generally, very good agreement is found. In addition, ICSs calculated with our independent atom model (IAM) with screening corrected additivity rule (SCAR) formalism, extended to account for interference (I) terms that arise due to the multi-centre nature of the scattering problem, are also reported. The sum of those ICSs gives the IAM-SCAR+I total cross section for electron-furfural scattering. Where possible, those calculated IAM-SCAR+I ICS results are compared against corresponding results from the present measurements with an acceptable level of accord being obtained. Similarly, but only for the band I and band II excited electronic states, we also present results from our Schwinger multichannel method with pseudopotentials calculations. Those results are found to be in good qualitative accord with the present experimental ICSs. Finally, with a view to assembling a complete cross section data base for furfural, some binary-encounter-Bethe-level total ionization cross sections for this collision system are presented.

Excitation of vibrational quanta in furfural by intermediate-energy electrons.

We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°-90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.

Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations.

The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

Intermediate energy electron impact excitation of composite vibrational modes in phenol.

We report differential cross section results from an experimental investigation into the electron impact excitation of a number of the low-lying composite (unresolved) vibrational modes in phenol (C6H5OH). The measurements were carried out at incident electron energies in the range 15-40 eV and for scattered-electron angles in the range 10-90°. The energy resolution of those measurements was typically ∼80 meV. Calculations, using the GAMESS code, were also undertaken with a B3LYP/aug-cc-pVDZ level model chemistry, in order to enable us to assign vibrational modes to the features observed in our energy loss spectra. To the best of our knowledge, the present cross sections are the first to be reported for vibrational excitation of the C6H5OH molecule by electron impact.

Differential cross sections for electron impact excitation of the electronic bands of phenol.

We report results from a joint theoretical and experimental investigation into electron scattering from the important organic species phenol (C6H5OH). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of C6H5OH. The measurements were carried out at energies in the range 15-40 eV, and for scattered-electron angles between 10° and 90°. The energy resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potentials calculations, with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were conducted at the static exchange plus polarisation (SEP)-level using a minimum orbital basis for single configuration interaction (MOBSCI) approach. Agreement between the measured and calculated DCSs was typically fair, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOBSCI.