Summary
A recent large‐scale assessment of bacterial communities across a range of UK soil types showed that bacterial community structure was strongly determined by soil pH. We analysed a data set ...of eukaryotic 454 sequencing 18S rDNA from the surveyed samples and showed significant differences in eukaryotic assemblages according to pH class, mostly between low pH and higher pH soils. Soil eukaryote communities (per sample) differed most at the taxonomic rank approximating to order level. Taxonomies assigned with the Protist Ribosomal Reference and the Silva 119 databases were taxonomically inconsistent, mostly due to differing 18S annotations, although general structure and composition according to pH were coherent. A relatively small number of lineages, mostly putative parasitic protists and fungi, drive most differences between pH classes, with weaker contributions from bacterivores and autotrophs. Overall, soil parasites included a large diversity of alveolates, in particular apicomplexans. Phylogenetic analysis of alveolate lineages demonstrates a large diversity of unknown gregarines, novel perkinsids, coccidians, colpodellids and uncharacterized alveolates. Other novel and/or divergent lineages were revealed across the eukaryote tree of life. Our study provides an in‐depth taxonomic evaluation of micro‐eukaryotic diversity, and reveals novel lineages and insights into their relationships with environmental variables across soil gradients.
There has always been an interest in the professional communities of libraries, archives and conservation science to find ways of estimating the rate of degradation of paper under archival ...conservation conditions. Previously we reported a number of considerations for developing a kinetic degradation model based on Whatman no.1 paper. In the present research, this model was extended to 10 different papers and validated. Various physical and chemical properties of acidic, neutral, and alkaline papers were measured, such as the degree of polymerization (DP), tensile strength, equilibrium moisture content, and pH, as well as alkaline fillers content when applicable. The activation energy (
E
a
) based on DP of cellulose and zero-span tensile strength were determined.
E
a
and pH had the most significant influence on the simulated decay of paper. Papers with a high
E
a
(> 120 kJ mol
−1
), alkaline such as those containing at least 2% CaCO
3
, and acidic—but good printing quality papers made of bleached chemical pulp– were found the most durable in ambient conditions. Papers with a lower
E
a
(< 110 kJ mol
−1
) such as lignocellulosic papers containing significant amount of mechanical pulp were much less stable over time. Whatman filter papers, used as models of pure cellulosic papers, were found to have low
E
a
despite the good quality cotton fibers. A generic isoperm equation based on
E
a
was developed to predict the changes in the state of papers under various climatic conditions, and was applicable independently of the pH of the paper. The model developed allows a better quantification of the deterioration rate of printing papers such as those that are currently, and will be in the future, found in our archival collections.
The reactivity towards cellulose of various volatile compounds commonly released by paper was studied. Sheets of Whatman No. 1 (W1) and No. 40 (W40) were exposed to various concentrations of these ...compounds in vapour phase ranging from 20 to 80 ppm in closed vessels for 52 days in controlled ambient conditions, after which they were hygrothermally aged. The measured properties of the paper were copper number, degree of polymerization, zero-span breaking length, pH and yellowness index. The results showed that hydrogen peroxide was the most aggressive among the volatile compounds tested as it severely degraded W1 cellulose. The exposure of W1 to formic acid led to significant degradation, designating this volatile organic compound (VOC) as the most reactive toward cellulose among the carboxyl and carbonyl functionalized VOCs tested. On the other hand, acetic acid was found comparatively less reactive. Nitrogen oxides, which were produced up to 3 ppm from a side-reaction of the carboxylic acids with the magnesium nitrate used to control the relative humidity in the closed vessels, appeared to contribute significantly to the degradation despite their low concentration. Antagonistic effects were evidenced in binary vapour mixtures where the presence of aldehydes (formaldehyde and acetaldehyde) counteracted substantially the degradation induced by the most reactive compounds. It was also shown that acetaldehyde, hexanal and furfural in individual exposures had little to no reactivity. Upon exposure to formaldehyde, the rate of glycosidic bond cleavage of cellulose induced by the ageing of W1 was significantly reduced.
The aim of this research was to design a model for simulating the degradation of paper in various environmental conditions by taking into consideration all the parameters (exogenous and endogenous) ...that influence the overall process of the acid catalyzed hydrolysis of cellulose. Three kinetic equations (Ekenstam, Calvini, and Ding and Wang) for determining the degradation rate coefficient (
k
) were compared. For this purpose, previously published and new experimental data on the degradation of pure and unsized cotton linter papers (neutral and acidic) upon ageing were used. The frequency factor parameter (
A
) in the Arrhenius formula was adjusted with additional input factors in the expression of
A
proposed by Zou et al. (Cellulose 3:243–267,
1996a
). The model takes into account the increase of the acidity and the decrease of the moisture content induced during paper degradation. Besides the temperature and humidity, external gaseous pollutants (NO
2
, formic and acetic acids) were also taken into account as degradation factors. The model can be used to simulate cellulose depolymerisation of cotton papers exposed to single pollutants, but reached a limit for simulating with confidence the degradation of papers exposed simultaneously to multiple volatile compounds, due to the lack of available data, especially concerning certain volatile compounds counter-degradation effects. Future adjustments can be done when more experimental data becomes available.
Summary
Background
Faecal microbiota transplantation (FMT) has become routine in managing recurrent C. difficile infection (CDI) refractory to antibiotics.
Aim
To compare clinical response and ...improvements in colonic microbiota diversity in subjects with recurrent CDI using different donor product.
Methods
Seventy‐two subjects with ≥3 bouts of CDI were randomised in a double‐blind study to receive fresh, frozen or lyophilised FMT product via colonoscopy from 50 g of stool per treatment from eight healthy donors. Recipients provided stools pre‐ and 7, 14 and 30 days post‐FMT for C. difficile toxin and, in a subset, microbiome composition by 16S rRNA gene profiling.
Results
Overall resolution of CDI was 87% during 2 months of follow‐up after FMT. Stool samples before FMT had significantly decreased bacterial diversity with a high proportion of Proteobacteria compared to donors. Cure rates were highest for the group receiving fresh product seen in 25/25 (100%), lowest for the lyophilised product 16/23 (78%; P = 0.022 vs. fresh and 0.255 vs. frozen) and intermediate for frozen product 20/24 (P = 0.233 vs. fresh). Microbial diversity was reconstituted by day 7 in the subjects receiving fresh or frozen product. Improvement in diversity was seen by day 7 in those randomised to lyophilised material with reconstitution by 30 days.
Conclusions
Comparative efficacy in faecal microbiota transplantation was observed in subjects receiving fresh or frozen faecal product from the same donors. The lyophilised product had a slightly lowered efficacy compared with fresh product, but it resembled other treatments in microbial restoration 1 month after faecal microbiota transplantation.
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•NFL-peptides adopt diverse ultrastructural organization when functionalizing liposomes.•The BIOT-NFL-peptide is the most adsorbed on the liposome surface.•NFL-peptides are enhancing ...cellular uptake of liposomes in GBM cells.•Liposome functionalization with NFL-peptides is a promising GBM targeting nanosystem.
The NFL-peptide was discovered almost 20 years ago, and its targeting properties were assessed alone or in combination with lipid nanocapsules (LNC), magnetic porous silicon nanorods, or gold nanoparticles. Results highlighted a better targeting of cancer cells, in particular glioblastoma and pancreas cancer. Considering the large use of liposomes (LPs) as an hydrophilic drug delivery system, this study explored the possibility to functionalize liposomes with three different sequences of NFL-peptides: native (NFL-peptide), biotinylated (BIOT-NFL) and coupled to fluorescein (FAM-NFL). Dynamic Light Scattering (DLS) complemented by cryo-electron microscopy (CEM) showed a peculiar ultrastructural arrangement between NFL-peptides and liposomes. Based on this architectural interaction, we investigated the biological contribution of these peptides in LPs-DiD glioblastoma cellular uptake. Flow cytometry complemented by confocal microscopy experiments demonstrated a consequent and systematic increased uptake of LPs-DiD into F98 cells when their surface was decorated with NFL-peptides. The intra-cellular distribution of these liposomes via an organelle tracker indicated the presence of LPs-DiD in lysosomes after 4 h. Based on the properties of this NFL-peptide, we showed in this work the crucial role of NFL peptide as an effective and promising actor to potentiate nanoparticles entry in glioblastoma cell lines.
The role of sex hormones in regulating immune responses in the female genital tract has been recognized for decades. More recently, it has become increasingly clear that sex hormones regulate ...susceptibility to sexually transmitted infections through direct and indirect mechanisms involving inflammation and immune responses. The reproductive cycle can influence simian/human immunodeficiency virus (SHIV) infections in primates and HIV-1 infection in
cervical tissues from women. Exogenous hormones, such as those found in hormonal contraceptives, have come under intense scrutiny because of the increased susceptibility to sexually transmitted infections seen in women using medroxyprogesterone acetate, a synthetic progestin-based contraceptive. Recent meta-analyses concluded that medroxyprogesterone acetate enhanced HIV-1 susceptibility in women by 40%. In contrast, estradiol-containing hormonal contraceptives were not associated with increased susceptibility and some studies reported a protective effect of estrogen on HIV/SIV infection, although the underlying mechanisms remain incompletely understood. Recent studies describe a key role for the vaginal microbiota in determining susceptibility to sexually transmitted infections, including HIV-1. While
spp.-dominated vaginal microbiota is associated with decreased susceptibility, complex microbiota, such as those seen in bacterial vaginosis, correlates with increased susceptibility to HIV-1. Interestingly, sex hormones are inherently linked to microbiota regulation in the vaginal tract. Estrogen has been postulated to play a key role in establishing a
-dominated microenvironment, whereas medroxyprogesterone acetate is linked to hypo-estrogenic effects. The aim of this Review is to contribute to a better understanding of the sex-hormone-microbiome-immunity axis, which can provide key information on the determinants of HIV-1 susceptibility in the female genital tract and, consequently, inform HIV-1 prevention strategies.
SUMMARY
The 15 January 2022 eruption of the Hunga–Tunga volcano generated a Lamb pressure wave propagating all over the globe and triggering a tsunami throughout the planet. A first atmospheric wave ...arrived 16 hr after the eruption on the French Mediterranean coasts and propagated southward. A second one originating from Africa was observed 4 hr later with an attenuated amplitude. The first wave can be roughly defined either by a N wave or a sinusoid signal with a period close to 50 min and an amplitude of 130 Pa. In the Mediterranean Sea, the tsunami was recorded by almost all standard coastal tide gauges or pressure gauges. The French tide gauge stations recorded water waves with amplitudes ranging from a few centimetres to 10 cm and with periods ranging from 10 min to 1 hr. Numerical simulation of the tsunami is performed by the operational code Taitoko for different atmospheric sources. Non-linear shallow water equations are solved by a finite-difference method, using the nested multigrid approach. The tsunami is generated by calculating analytically the atmospheric pressure gradient in the momentum equations. Comparisons of time-series between numerical solutions and records are satisfactory for most tide-gauges along the French Mediterranean coast. Sensitivity analysis on the atmospheric source and on the resolution is performed. For most tide-gauge stations, numerical results show that the wave forms depend first on local resonance phenomena.
Cardiac mitochondrial metabolism provides 90% of the ATP necessary for the contractile exertion of the heart muscle. Mitochondria are therefore assumed to play a pivotal role in heart failure (HF), ...cardiovascular disease and ageing. Heat stress increases energy metabolism and oxygen demand in tissues throughout the body and imposes a major challenge on the heart, which is suspected of being the first organ to fail during heat stress. The underlying mechanisms inducing heart failure are still unclear. To pinpoint the processes implicated in HF during heat stress, we measured mitochondrial respiration rates and hydrogen peroxide production of isolated Arctic char (Salvelinus alpinus) heart mitochondria at 4 temperatures: 10°C (acclimation), 15°C, 20°C and 25°C (just over critical maximum). We found that at temperature ranges causing the loss of an organism's general homeostasis (between 20°C and 25°C) and with a substrate combination close to physiological conditions, the heat-induced increase in mitochondrial oxygen consumption levels off. More importantly, at the same state, hydrogen peroxide efflux increased by almost 50%. In addition, we found that individuals with low mitochondrial respiration rates produced more hydrogen peroxide at 10°C, 15°C and 20°C. This could indicate that individuals with cardiac mitochondria having a low respiratory capacity, have a more fragile heart and will be more prone to oxidative stress and HF, and less tolerant to temperature changes and other stressors. Our results show that, at temperatures close to the thermal limit, mitochondrial capacity is compromised and ROS production rates increase. This could potentially alter the performance of the cardiac muscle and lead to heat-induced HF underlining the important role that mitochondria play in setting thermal tolerance limits.
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•Mitochondria seem to play an essential role in heat induced heart failure.•At high temperatures, heart mitochondrial capacity is limited & ROS production increases.•Higher maximum respiration rates result in lower ROS production at temperatures below the upper critical limit.
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In this paper, we show that the polymorphic transformation γ → α of sorbitol upon milling involves a transient amorphization of the material. This could be done by comilling sorbitol ...with a high Tg amorphous material (Hydrochlorothiazide, Tg = 115 °C) to stabilize any transient amorphous fractions of sorbitol through the formation of a molecular alloy. The results indicate that for large sorbitol concentration (50%), the comilling leads to a heterogeneous mixture made of sorbitol crystallites in the form α embedded into an amorphous molecular alloy sorbitol / HCT. Interestingly, the kinetic investigation of this transformation reveals that these two components are not produced simultaneously. On the contrary, they are produced one after the other, during two distinct consecutive stages. The first stage concerns the formation of the amorphous alloy while the second one concerns the polymorphic transformation γ → α of the fraction of crystalline sorbitol not involved in the alloy. These results clearly indicate that the polymorphic transformation of sorbitol upon milling results from the recrystallization of a transient amorphous state generated by the mechanical shocks. The investigations were mainly performed by calorimetry and powder X-ray diffraction.
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