Recurrence relations for four-electron integrals over Gaussian basis functions

In the spirit of the Head-Gordon-Pople algorithm, we report vertical, transfer and horizontal recurrence relations for the efficient and accurate computation of four-electron integrals over Gaussian basis functions. Our recursive approach is a generalization of our algorithm for three-electron integrals [J.~Chem.~Theory Comput.~12, 1735 (2016)]. The RRs derived in the present study can be applied to a general class of multiplicative four-electron operators. In particular, we consider various types of four-electron integrals that may arise in explicitly-correlated F12 methods.Comment: 11 pages, 3 figures and 2 table

Changes in the levels of cytokines, chemokines and malaria-specific antibodies in response to Plasmodium falciparum infection in children living in sympatry in Mali

<p>Abstract</p> <p>Background</p> <p>The Fulani are known to be less susceptible to <it>Plasmodium falciparum </it>malaria as reflected by lower parasitaemia and fewer clinical symptoms than other sympatric ethnic groups. So far most studies in these groups have been performed on adults, which is why little is known about these responses in children. This study was designed to provide more information on this gap.</p> <p>Methods</p> <p>Circulating inflammatory factors and antibody levels in children from the Fulani and Dogon ethnic groups were measured. The inflammatory cytokines; interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12p70, tumor necrosis factor (TNF) and the chemokines; regulated on activation normal T cell expressed and secreted (RANTES), monokine-induced by IFN-gamma (MIG), monocyte chemotactic protein (MCP)-1 and IFN-gamma-inducible protein (IP)-10 were measured by cytometric bead arrays. The levels of interferon (IFN)-alpha, IFN-gamma and malaria-specific antibodies; immunoglobulin (Ig) G, IgM and IgG subclasses (IgG1-IgG4) were measured by ELISA.</p> <p>Results</p> <p>The results revealed that the Fulani children had higher levels of all tested cytokines compared to the Dogon, in particular IFN-gamma, a cytokine known to be involved in parasite clearance. Out of all the tested chemokines, only MCP-1 was increased in the Fulani compared to the Dogon. When dividing the children into infected and uninfected individuals, infected Dogon had significantly lower levels of RANTES compared to their uninfected peers, and significantly higher levels of MIG and IP-10 as well as MCP-1, although the latter did not reach statistical significance. In contrast, such patterns were not seen in the infected Fulani children and their chemokine levels remained unchanged upon infection compared to uninfected counterparts. Furthermore, the Fulani also had higher titres of malaria-specific IgG and IgM as well as IgG1-3 subclasses compared to the Dogon.</p> <p>Conclusions</p> <p>Taken together, this study demonstrates, in accordance with previous work, that Fulani children mount a stronger inflammatory and antibody response against <it>P. falciparum </it>parasites compared to the Dogon and that these differences are evident already at an early age. The inflammatory responses in the Fulani were not influenced by an active infection which could explain why less clinical symptoms are seen in this group.</p

Perspectives on the use of transcriptomics to advance biofuels

As a field within the energy research sector, bioenergy is continuously expanding. Although much has been achieved and the yields of both ethanol and butanol have been improved, many avenues of research to further increase these yields still remain. This review covers current research related with transcriptomics and the application of this high-throughput analytical tool to engineer both microbes and plants with the penultimate goal being better biofuel production and yields. The initial focus is given to the responses of fermentative microbes during the fermentative production of acids, such as butyric acid, and solvents, including ethanol and butanol. As plants offer the greatest natural renewable source of fermentable sugars within the form of lignocellulose, the second focus area is the transcriptional responses of microbes when exposed to plant hydrolysates and lignin-related compounds. This is of particular importance as the acid/base hydrolysis methods commonly employed to make the plant-based cellulose available for enzymatic hydrolysis to sugars also generates significant amounts of lignin-derivatives that are inhibitory to fermentative bacteria and microbes. The article then transitions to transcriptional analyses of lignin-degrading organisms, such as Phanerochaete chrysosporium, as an alternative to acid/base hydrolysis. The final portion of this article will discuss recent transcriptome analyses of plants and, in particular, the genes involved in lignin production. The rationale behind these studies is to eventually reduce the lignin content present within these plants and, consequently, the amount of inhibitors generated during the acid/base hydrolysis of the lignocelluloses. All four of these topics represent key areas where transcriptomic research is currently being conducted to identify microbial genes and their responses to products and inhibitors as well as those related with lignin degradation/formation.clos

Densities and viscosities of mono(ethylene glycol) plus 2-amino-2-methyl-1-propanol plus Water

The densities and viscosities of ternary mixtures of mono(ethylene glycol) (MEG) + 2-amino-2-methyl-1-propanol (AMP) + water have been measured at temperatures of 25 to 40 degreesC. The water content varied in the range 1.4 to 15.6 mol %, and the amine concentration varied from 0 to 11.8 mol %. The excess volumes were calculated from the experimental data and fitted to a simple Redlich-Kister type polynomial relation. The equation of Grunberg and Nissan for the viscosity of liquid mixtures was used to correlate the viscosity data

Effect of different forms of alkali treatment on specific fermentation inhibitors and on the fermentability of lignocellulose hydrolysates for production of fuel ethanol

Treatment with alkali, particularly overliming, has been widely used as a method for the detoxification of lignocellulose hydrolysates prior to ethanolic fermentation. However, the mechanisms behind the detoxification effect and the influence of the choice of cation have not been well understood. In this study, a dilute acid hydrolysate of spruce and an inhibitor cocktail consisting of six known inhibitors were used to investigate different alkali detoxification methods. The various treatments included the addition of calcium hydroxide, sodium hydroxide, potassium hydroxide, and ammonia to pH 10.0 and subsequent adjustment of the pH to 5.5 with either sulfuric or hydrochloric acid as well as treatment with the corresponding amounts of calcium, sodium, and potassium as sulfate or chloride salts at pH 5.5. An RP-HPLC method was developed for the separation of 18 different inhibitors in the hydrolysate, including furaldehydes and phenolics. Detection and quantification were carded out by means of UV, DAD, and ESI-MS in negative mode. Treatment of the spruce hydrolysate with alkali resulted in up to similar to40% decrease in the concentration of furaldehydes. The effects on the aromatic compounds were complex. Furthermore, SFE was performed on the precipitate formed during alkali treatment to evaluate the inhibitor content of the precipitate, and the following RP-HPLC analysis implied that potential inhibitors were removed mainly through conversion rather than through filtration of precipitate. Parallel experiments in which sulfuric acid or hydrochloric acid was used for acidification to pH 5.5 after alkali treatment indicated that the choice of anion did not affect the removal of inhibitors. Detoxification with calcium hydroxide and ammonia resulted in better fermentability using Saccharomyces cerevisiae than detoxification with sodium hydroxide. The results from the experiments with the inhibitor cocktail indicated that the positive effects of alkali treatment are difficult to explain by removal of the inhibitors only and that possible stimulatory effects on the fermenting organism warrant further attention

Supercritical fluid extraction of a lignocellulosic hydrolysate of spruce for detoxification and to facilitate analysis of inhibitors

This work describes a novel approach to detoxify lignocellulosic hydrolysates and facilitate the analysis of inhibitory compounds, namely supercritical fluid extraction (SFE). The efficiency of the fermentation of lignocellulosic dilute-acid hydrolysates depends upon the composition of the hydrolysate and the organism used. Furthermore, it has been shown that inhibitors in the hydrolysate reduce the fermentation yield. This knowledge has given rise to the need to identify and remove the inhibiting compounds. Sample clean-up or work-up steps, to provide a clean and concentrated sample for the analytical system, facilitate the characterization of inhibitors, or indeed any compound in the hydrolysates. Removal of inhibitors was performed with countercurrent flow supercritical fluid extraction of liquid hydrolysates. Three different groups of inhibitors (furan derivatives, phenolic compounds, and aliphatic acids) and sugars were subsequently analyzed in the hydrolysate, extracted hydrolysate, and extract. The effect of the SFE treatment was examined with respect to fermentability with Saccharomyces cerevisiae. Not only did the extraction provide a clean and concentrated sample (extract) for analysis, but also a hydrolysate with increased fermentability as well as lower concentrations of inhibitors such as phenolics and furan derivatives. (C) 2002 Wiley Periodicals, Inc

New Transcorrelated Method Improving the Feasibility of Explicitly Correlated Calculations

Abstract: We recently developed an explicitly correlated method using the transcorrelated Hamiltonian, which is preliminarily parameterized in such a way that the Coulomb repulsion is compensated at short inter-electronic distances. The extra part of the effective Hamiltonian features short-ranged, size-consistent, and state-universal. The localized and frozen nature of the correlation factor makes the enormous three-body interaction less important and enables us to bypass the complex nonlinear optimization. We review the basic strategy of the method mainly focusing on the applications to single-reference many electron theories using modified Møller-Plesset partitioning and biorthogonal orbitals. Benchmark calculations are performed for 10-electron systems with a series of basis sets