A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk

Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations of a FUV-irradiated protoplanetary disk in the Orion Nebula. Emission lines are detected from the PDR; modeling their kinematics and excitation allowed us to constrain the physical conditions within the gas. We quantified the mass-loss rate induced by the FUV irradiation and found that it is sufficient to remove gas from the disk in less than a million years. This is rapid enough to affect giant planet formation in the disk.

Screening for hepatitis C in psychiatric population

Introduction

A meta-analysis from 2016 estimates prevalence of hepatitis C to be superior in people with severe mental illness than general population. In France, positivity for hepatitis C is estimated at 0,75% of general population and 0.3% with a detectable viral load. No recent study was conducted to determine seroprevalence of hepatitis C in population admitted in psychiatric institution.

Objectives

The aims of this study are to determine seroprevalence of hepatitis C in population admitted in psychiatric institution and describe the profile of infected patients.

Methods

From january 2020 to october 2020, screening test for hepatitis C, hepatitis B and HIV was proposed to every patient admitted at the reception unit of Ravenel Hospital. In case of positivity, viral load was realised.

Results

Between January 7^th and Octobre 1^st , 407 patients greed to the screening test. Among them, 17 (4,2%) were tested positive to hepatits C and viral load was detectable in 9/17 positives, which lead to a 2,2% seroprevalence of hepatitis C infection in the studied population. The patients with positive screening had a mean age of 40 years old. 82% of them were males. 16 admit using intoxicating substances and 10 were still current users at the time of the study. They were hospitalized for addictology purpose (5/17), psychosis (6/17), mood disorder (5/17), personality disorder (2/17), adjustement disorder (2/7). 10/17 had an alcohol use disorder.

Conclusions

This study confirms seroprevalence of hepatitis C infection in psychiatric population is seven times that of general population. This justifies a systematic screening of this population.

Disclosure

No significant relationships.

Mixed aliphatic and aromatic composition of evaporating very small grains in NGC 7023 revealed by the 3.4/3.3 μm ratio

CONTEXT

A chemical scenario was proposed for photon-dominated regions (PDRs) according to which UV photons from nearby stars lead to the evaporation of very small grains (VSGs) and the production of gas-phase polycyclic aromatic hydrocarbons (PAHs).

AIMS

Our goal is to achieve better insight into the composition and evolution of evaporating very small grains (eVSGs) and PAHs through analyzing the infrared (IR) aliphatic and aromatic emission bands.

METHODS

We combined spectro-imagery in the near- and mid-IR to study the spatial evolution of the emission bands in the prototypical PDR NGC 7023. We used near-IR spectra obtained with the IRC instrument onboard AKARI to trace the evolution of the 3.3 μm and 3.4 μm bands, which are associated with aromatic and aliphatic C-H bonds on PAHs. The spectral fitting involved an additional broad feature centered at 3.45 μm that is often referred to as the plateau. Mid-IR observations obtained with the IRS instrument onboard the Spitzer Space Telescope were used to distinguish the signatures of eVSGs and neutral and cationic PAHs. We correlated the spatial evolution of all these bands with the intensity of the UV field given in units of the Habing field G0 to explore how their carriers are processed.

RESULTS

The intensity of the 3.45 μm plateau shows an excellent correlation with that of the 3.3 μm aromatic band (correlation coefficient R = 0.95) and a relatively poor correlation with the aliphatic 3.4 μm band (R=0.77). This indicates that the 3.45 μm feature is dominated by the emission from aromatic bonds. We show that the ratio of the 3.4 μm and 3.3 μm band intensity (I3.4/I3.3) decreases by a factor of 4 at the PDR interface from the more UV-shielded layers (G0 ~ 150, I3.4/I3.3 = 0.13) to the more exposed layers (G0 > 1 × 104, I3.4/I3.3 = 0.03). The intensity of the 3.3 μm band relative to the total neutral PAH intensity shows an overall increase with G0, associated with an increase of both the hardness of the UV field and the H abundance. In contrast, the intensity of the 3.4 μm band relative to the total neutral PAH intensity decreases with G0, showing that their carriers are actively destroyed by UV irradiation and are not efficiently regenerated. The transition region between the aliphatic and aromatic material is found to correspond spatially with the transition zone between neutral PAHs and eVSGs.

CONCLUSIONS

We conclude that the photo-processing of eVSGs leads to the production of PAHs with attached aliphatic sidegroups that are revealed by the 3.4 μm emission band. Our analysis provides evidence for the presence of very small grains of mixed aromatic and aliphatic composition in PDRs.

Joint analysis of BICEP2/keck array and Planck Data

We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400  deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2  μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150  GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

[Conservation and destruction of autologous and allogeneic cryopreserved cellular products: recommendations from the SFGM-TC]

Thousands of autologous and at less extent allogeneic hematopoietic stem cells (HSC) bags are cryopreserved in France. The majority of autologous HSC grafts are used within a year after collection. However, many bags are still unused and cryopreserved for many years. In France and on a European scale, the ever-growing number of cryopreserved bags represents a real economic health concern. Indeed, the cost of storage is about 100€ per bag and per year. In addition, quality and therapeutic value of these long-term cryopreserved grafts needs to be evaluated. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from its member centers across France. These workshops took place in September 2013 in Lille. In this article, we addressed the issue of the destruction of long-term cryopreserved grafts be them autologous or allogeneic and provide recommendations regarding their destruction.

[Quality control of defrosted cord blood units: results from an inter-laboratory study]

PURPOSE

Today, haematopoietic stem cell graft from placental blood concerns more than 15 % of allogeneic grafts. An inter-laboratory study of the quality control of defrosted cord blood units has been coordinated by the French society for cell and tissue bioengineering (SFBCT), with the cord blood bank of Bourgogne Franche-Comté and controlled by the French health products safety agency (Afssaps). The aim of this study is to ensure the inter-laboratory reproducibility of the quality controls practised by the banks during defrosting. The cellular outputs were analyzed according to the defrosting techniques, according to the method used in flow cytometry: single-platform (SP) versus double-platform (DP), or the product nature, i.e. in total blood or miniaturized.

METHODS

Forty-two units of placental blood (USP), which were out of range were provided for defrosting to 14 participating sites. USP were defrosted and controlled according to the procedures of each bank. Once the USP is defrosted, a part of the product was controlled by the site and the other part by Afssaps. Following controls were carried out: numeration of the total nucleated cells (TNC) and of CD34+ cells (made by a SP method in Afssaps) and functional assay.

RESULTS

Concerning TNC, the defrosting sites obtained a cellular output of 94 %+/-28 in day 0 compared with an output of 72 %+/-24 in Afssaps showing a rather good stability of the USP transmitted with an average deviation of 23 %+/-22. The freezing process with or without reduction of volume does not affect this variation. Concerning the numeration of CD34+ cells, the average deviation between the participating sites and Afssaps was 29 %+/-23 compared with 21 %+/-16 for the sites using a SP method against 47 %+/-25 for those using a DP method. The CD34+ outputs are equal to 82 % +/- 60 in day 0 for the participating sites against 52 %+/-20 for Afssaps. For the sites using a DP method, it is stressed that this output is particularly high with a rate of 126 %+/-90 (n=15) whereas it is 62 %+/-20 (n=32) for the sites using a SP method.

CONCLUSION

These results underline a good stability of viable CD34+ cells and a greater reliability of the SP methods for the CD34+ cell numeration for these defrosted USP. Lastly, the results of the functional assay regarding the average clonogenicities (equal to 15 %) reinforce the conclusions on the quality of the defrosted products.

Allogeneic stem-cell transplantation with fludarabine and 2-Gy TBI-based conditioning regimen for chronic hematological malignancy: A study of 25 consecutive patients and a literature review

We analyzed the outcome of 25 consecutive patients with chronic hematological malignancy who underwent allogeneic stem-cell transplantation conditioned with fludarabine (30 mg/m2/day, thrice) and total body irradiation (2 Gy). All patients received peripheral blood stem cells from an HLA-identical sibling donor. With a median follow-up of 769 days (range, 244 - 1231), the estimated 2-year overall survival (OS), event-free survival (EFS), transplantation-related mortality and relapse rates were 53%, 45%, 27%, and 39%, respectively. All patients had initial engraftment. Acute Grade II - IV graft-versus-host disease (GVHD) was recorded in 14 patients (56%), including 7 (28%) with Grade III - IV GVHD. Sixteen of the 23 patients (70%) who survived more than 100 days developed chronic GVHD. OS and EFS were adversely influenced by acute Grade III - IV GVHD (p < 0.001 and p = 0.033, respectively), but chronic GVHD seemed to favorably influence these two parameters (p = 0.03 and p < 0.001, respectively). Patients with full-donor chimerism at day 30 had lower relapse rates, as did those who received high-dose allogeneic CD8+ lymphocytes with their graft (p = 0.026). Collectively, these results provide a framework for refining nonmyeloablative conditioning, to improve outcome with an acceptable risk of GVHD.

Toxoplasma gondii-structure variations of the antigen P30

The major surface immunodominant antigen (P30) of Toxoplasma gondii was purified by two methods (i) SDS-PAGE and (ii) immunoaffinity chromatography. The secondary elements within this protein were assessed by circular dichroism and spectra obtained were compared to those proposed by Manavalan & Johnson (1983). The results allowed us to determine an all beta protein status for this antigen. This experimental result was in agreement with the predicted secondary structures deduced from the P30 primary sequence. Modifications in conformation according to pH and temperature were recorded without any change in immunoactivity. The epitope, which was always recognized by a monoclonal antibody against P30, could be a linear epitope.

Quantitative immunolocalization of four immunodominant antigens of Toxoplasma gondii

Ultrastructural localization of four immunodominant antigens of Toxoplasma gondii was investigated quantitatively on thin sections and replicas by an immunogold technique using four monoclonal antibodies (Mab). On immunoblot Mab IV47, GII9, II38 and IE10 identified proteins of 28, 30, 45 and 66-70 kDa, respectively. Use of digital image analyzer and a semi-automatic procedure developed by us, the patterns of label distribution were compared in three cell structures: cell surface, submembrane area and rhoptries. On the whole cell surface, protein P28 and P30 were 2.5 and 4 times more abundant than P66-70 respectively. The protein P28 was essentially concentrated in the submembrane area with a labeling of 195.4 +/- 46.7 gold particles/microns 2 that follows a decreasing gradient from this area to the cell centre. In the rhoptries, all four antigens were detected, P45 and P66-70 being major with a labeling of 97.1 +/- 31.1 gold particles/microns 2 and 155.1 +/- 39.3 gold particles/microns 2 respectively. The results support the hypothesis that rhoptries are the essential site for antigen storage.

Toxoplasma gondii: immunocytochemistry of four immunodominant antigens with monoclonal antibodies

Four monoclonal antibodies in which diagnostic usefulness has been observed, concerning congenital, acquired, and reactivated toxoplasmosis, were raised against Toxoplasma gondii tachyzoïtes in order to localize immunodominant antigens. On immunoblots, it appears that McAb IV47, McAB GII9, McAb II38, and McAb IE10 identify families of proteins with estimated molecular weights of 28-30 kDa, 30 kDa, 45-50 kDa, and 66-70 kDa, respectively. By immunogold preembedding techniques one can observe an homogeneous labeling of the outer pellicle of the tachyzoïtes with the McAb GII9 and IV47 and a light labeling with the McAb II38 and IE10. The three-dimensional observation of cell surface antigens is performed by applying a modified metal extraction replica method, i.e., A plasma polymerization method of glow discharge by Tanaka (1979). By immunogold preembedding techniques [with saponin permeabilization (0.1%)], and by immunogold postembedding techniques, a labeling of the rhoptries is observed with McAb GII9 and McAb IV47 but essentially all label is found with McAb II38 and IE10. With McAb GII9 a uniform labeling is observed on the cell surface. By immunoenzymatic techniques (peroxidase) a cell surface labeling is observed with the four McAb. Intracellular Toxoplasma, the outer pellicle, and the vesicles of the network (elaborated by Toxoplasma in parasitophorous vacuole) are also labeled with McAb IE10. These results indicate that McAb GII9 recognizes antigens of the antigen family (P 30) located on the cell surface and in the rhoptries. The antigen recognized by McAb IV47 is essentially located on and beneath the Toxoplasma cell surface membrane, and McAb II38 and IE10 identify preferentially rhoptry proteins.

[Choice of antibiotics in periodontology]

For periodontal treatment, the use and choice of antibiotics is a controversial matter. There are many medical reasons for prescribing antibiotics before, during and after periodontal treatment. The purpose of this paper is to review the indications and reasons for antibiotherapy in periodontics. Research is not very advanced in this domain and there is a need to understand the indications for antibiotherapy in periodontics.

Identification of hairy root loci in the T-regions of Agrobacterium rhizogenes Ri plasmids

Agrobacterium rhizogenes induces root formation at the wound site of inoculation in plants and inserts a fragment of its plasmid (Ri) into the plant nuclear DNA. Parts of the transferred region (T-region) of the Ri plasmid of A. rhizogenes strain A4 or 8196 are cloned in Escherichia coli. Insertions of the E. coli lacZ coding region into the hybrid plasmids were made in vivo using transduction by miniMu. Twenty insertions localized in the TL-DNA of pRiA4 (or pRi1855) and 2 inserts in the T-DNA of pRi8196 were obtained in E. coli. One of the TL-DNA insertions is saved up because it is linked to an internal T-DNA deletion; the others because they confer a lactose plus phenotype on E. coli; this indicates that the T-DNA harbours sequences that are expressed in E. coli. Fifteen of these T-DNA insertions were transfered to Agrobacterium where they substitute the corresponding wild-type T-DNA of the Ri plasmid by homologous recombination. These strains corresponding to insertion-directed mutagenesis were used to inoculate Daucus carota slices and stems and leaves of Kalanchoe daigremontiana. The two insertions strains obtained in the T-DNA of pRi8196 are avirulent on K. daigremontiana; but their phenotypes differ on D. carota slices, suggesting that insertions affect distinct loci on the T-DNA involved in hairy root formation. Only one insertion out of the twenty obtained in the TL-DNA of pRiA4 (or 1855) induces a loss of virulence on leaves of K. daigremontiana. However the TL-DNA deletion harbouring strain induces a loss of virulence on D. carota and K. daigremontiana (stems and leaves), confirming the importance of the TL-DNA for hairy root induction. re]19850711 rv]19851230 ac]19860114.

Multiple mutations in the transferred regions of the Agrobacterium rhizogenes root-inducing plasmids

Agrobacterium rhizogenes induces root formation at the site of inoculation in plants and inserts fragments of its Ri plasmid into the plant nuclear DNA. The transferred region (T-DNA) of the Ri plasmid of the A. rhizogenes strain A4 is made of two fragments, namely TL and TR; the latter harbors a sequence homology with the tms loci (responsible for auxin synthesis) of A. tumefaciens. On Daucus carota slices, single insertion mutations on the TL region of A. rhizogenes do not confer a mutant phenotype while an insertion-deletion in the TR region do confer a Basatt phenotype. Six double mutants with a single insertion in the TL region and the same deletion-insertion of the TR region were constructed. Three of these double mutants were avirulent on D. carota which indicates that in A. rhizogenes A4 the TL and the TR regions cooperate to confer a full infectious phenotype.

A search for interstellar H3O+

The P (2,1) line of H3O+, the hydroxonium ion, a key species in ion-molecule chemistry, has been sought in the interstellar medium and in Halley's Comet. In OMC1 and SgrB2, a line was detected which may possibly be attributed to H3O+. Verification of this identification must be accomplished through observation of the P(3,2) line at 364 GHz, or detection of isotopic variants. If we were to assume that the detected line arises from H3O+, we can deduce a fractional abundance X(H3O+) in OMC1 and SgrB2 of approximately 10(-9) and a production rate in Comet Halley of Q(H3O+) 10(28)s-1. These results would place H3O+ among the more abundant molecular ions in the interstellar gas in agreement with theoretical predictions.