Identification of a novel type of glucose dehydrogenase involved in the mineral weathering ability of Collimonas pratensis strain PMB3(1).

The exact molecular mechanisms as well as the genes involved in the mineral weathering (MW) process by bacteria remain poorly characterized. To date, a single type of glucose dehydrogenase (GDH) depending on a particular co-factor named pyrroloquinoline quinone (PQQ) is known. These enzymes allow the production of gluconic acid through the oxidation of glucose. However, it remains to be determined how bacteria missing PQQ-dependent GDH and/or the related pqq biogenesis genes weather minerals. In this study, we considered the very effective mineral weathering bacterial strain PMB3(1) of Collimonas pratensis. Genome analysis revealed that it does not possess the PQQ-based system. The use of random mutagenesis, gene complementation and functional assays allowed us to identify mutants impacted in their ability to weather mineral. Among them, three mutants were strongly altered on their acidification and biotite weathering abilities (58% to 75% of reduction compared to WT) and did not produce gluconic acid. The characterization of the genomic regions allowed noticeably to the identification of a Glucose/Methanol/Choline oxidoreductase. This region appeared very conserved among collimonads and related genera. This study represents the first demonstration of the implication of a PQQ-independent GDH in the mineral weathering process and explains how Collimonas weather minerals.

COVID-19 infection in first trimester of pregnancy marked by a liver cytolysis in a woman previously treated by hydroxychloroquine for repeated implantation failure: a case report.

BACKGROUND: In December 2019, a new disease (COVID-19) caused by a novel coronavirus called SARS-CoV-2 emerged in China and spread to many other countries. There is only limited data about the clinical features of COVID-19 during pregnancy, especially in first trimester. CASE PRESENTATION: We report a COVID-19 infection in a 35 years-old patient in first trimester of pregnancy and its consequent medical care. At 7 weeks of pregnancy, the patient, who did not have any pregestational comorbidities, complained of intense nausea and asthenia. An important liver cytolysis was discovered with biological perturbations of transaminases levels. No respiratory symptoms were recorded. Classical viral aetiologies and drug-related toxicity were discarded. Because of the aggravation of the symptoms and the occurrence of the breathlessness, the patient was tested for the COVID-19 in a nasopharyngeal swab. The RTq-PCR assay indicated the presence of SARS-CoV-2 RNA. In the absence of severe symptoms, the patient was monitored at home according to the French government guidelines. After a few days, the symptoms resolved without any complications. The pregnancy is still ongoing without any visible sequelae on the foetus so far. CONCLUSIONS: This first case illustrated the difficulty of COVID-19 diagnosis in patients with isolated digestive symptoms in first trimester of pregnancy that could be confused with gravida hyperemesis. Monitoring of pregnancy after an episode of COVID-19 should be strengthened with bimonthly foetal growth ultrasounds and doppler assessments because of the risks for intrauterine growth restriction. Comprehensive data on larger numbers of first trimester gravid women with COVID-19 are required to better understanding the overall impact of SARS-CoV-2 on maternal and birth outcomes.

Embryotoxicity testing of IVF disposables: how do manufacturers test?

STUDY QUESTION: How do manufacturers perform embryotoxicity testing in their quality control programs when validating IVF consumables? SUMMARY ANSWER: The Mouse Embryo Assay (MEA) and Human Sperm Survival Assay (HSSA) used for IVF disposables differed from one manufacturer to another. WHAT IS KNOWN ALREADY: Many components used in IVF laboratories, such as culture media and disposable consumables, may negatively impact human embryonic development. STUDY DESIGN, SIZE, DURATION: Through a questionnaire-based survey, the main manufacturers of IVF disposable devices were contacted during the period November to December 2018 to compare the methodology of the MEA and HSSA. We focused on catheters for embryo transfer, catheters for insemination, straws, serological pipettes, culture dishes and puncture needles used in the ART procedures. PARTICIPANTS/MATERIALS, SETTING, METHODS: We approached the manufacturers of IVF disposables and asked for details about methodology of the MEA and HSSA performed for toxicity testing of their IVF disposable devices. All specific parameters like mouse strains, number of embryos used, culture conditions (media, temperature, atmosphere), extraction protocol, subcontracting, and thresholds were registered and compared between companies. MAIN RESULTS AND THE ROLE OF CHANCE: Twenty-one companies were approached, of which only 11 answered the questionnaire. Significant differences existed in the methodologies and thresholds of the MEA and HSSA used for toxicity testing of IVF disposables. Importantly, some of these parameters could influence the sensitivity of the tests. LIMITATIONS, REASONS FOR CAUTION: Although we approached the main IVF manufacturers, the response rate was relatively low. WIDER IMPLICATIONS OF THE FINDINGS: Our study confirms the high degree of heterogeneity of the embryotoxicity tests performed by manufacturers when validating their IVF disposable devices. Currently, no regulations exist on this issue. Professionals should call for and request standardization and a future higher degree of transparency as regards embryotoxicity testing from supplying companies; moreover, companies should be urged to provide the users clear and precise information about the results of their tests and how testing was performed. Future recommendations are urgently awaited to improve the sensitivity and reproducibility of embryotoxicity assays over time. STUDY FUNDING/COMPETING INTEREST(S): This study did not receive any funding. L.D. declares a competing interest with Patrick Choay SAS. TRIAL REGISTRATION NUMBER: N/A.

[Polycystic ovary syndrome does not affect blastulation nor cumulative live birth rates]. / Le syndrome des ovaires polykystiques n'altère pas les taux de blastulation ni les taux cumulés de naissances vivantes.

OBJECTIVES: Polycystic ovarian syndrome (PCOS) brings complications in the management of the assisted reproductive technology (ART) because of an oocyte quality probably impaired due to modifications of intra- and extra-ovarian factors. Our study aimed to investigate the extended culture in PCOS patients and its influence on the cumulative live birth rates. METHODS: Fifty-nine PCOS patients (as defined by the Rotterdam criteria) and 114 normo-ovulatory patients (i.e. with tubal, male or idiopathic infertility, regular cycles and AMH>2ng/mL) aged<37years old who underwent a 1st or 2nd ART attempt with extended culture to day 6 were included from October 2015 to December 2017. The blastulation and cumulative live birth rates were compared between the two groups. RESULTS: The PCOS and control patients were 32.22 and 32.91years old respectively (P=0.05). The median number of oocytes retrieved was significantly higher in the PCOS group and the median oocyte maturity rate significantly lower compared with controls. The blastulation rates were similar between the PCOS and the control groups, respectively 57.8% vs. 58.6%, P=0.88. Because of the risks of hyperstimulation syndrome, a freeze all strategy was achieved for 38.9% of PCOS patients vs. 14.0% of the control patients (P<0.01). The cumulative live birth rates were not statistically different: 31.7% in the PCOS group vs. 37.2% in the control group, P=0.50. CONCLUSIONS: PCOS was not observed to affect the extended culture nor the cumulative live birth rates in comparison to normo-ovulatory patients, supporting the blastocyst transfer strategy as a suitable option to PCOS patients.

Caballeronia mineralivorans sp. nov., isolated from oak-Scleroderma citrinum mycorrhizosphere.

Six bacterial strains were isolated from the oak-Scleroderma citrinum ectomycorrhizosphere in acidic and nutrient-poor forest soil for their high efficacy to weather minerals. Four of the six isolates, PML1(12)T and PML1(4), PML1(14) and PML1(16), were further characterized extensively. They were Gram negative, obligate aerobic, motile, non spore forming and rod-shaped. The major fatty acids of strain PML1(12)T were cyclo-C17:0, cyclo-C19:0-ω8c, C16:0 and C18:1-ω7c. The GC content of the DNA was 60.8%. The 16S rRNA and GyrB analyses showed that the four PML strains formed a distinct phylogenetic lineage within the genus Caballeronia, most closely related to Caballeronia udeis. This result was confirmed by whole-genome phylogeny analyses done on strain PML1(12)T. The results of digital DNA-DNA relatedness further supported the separation of the new isolates from closely related species. Morphological, chemotaxonomic properties were also consistent with the description of the genus Caballeronia. It is therefore proposed that strains PML1(12)T and PML1(4), PML1(14) and PML1(16) be recognized as a novel species, for which the name Caballeronia mineralivorans sp. nov. is proposed. The type strain is PML1(12)T (=DSM 104028 and LMG 2991).

Can a target zone safer than Lewinnek's safe zone be defined to prevent instability of total hip arthroplasties? Case-control study of 56 dislocated THA and 93 matched controls.

BACKGROUND: Various factors contribute to instability of total hip arthroplasty (THA), with implant orientation being a major contributor. We performed a case-control study with computed tomography (CT) data to determine whether: 1) orientation contributes to THA instability and 2) a safer target zone for stability than Lewinnek's classic safe zone can be defined. MATERIAL AND METHODS: We included prospectively 363 cases of THA dislocation that occurred during the calendar 2013 year in 24 participating hospitals. Of the 128 dislocations that occurred in patients who underwent THA at these centers, 56 (24 anterior, 32 posterior) had CT scans, thus were included in the analysis. The control group was matched 4:1 based on implant type, year of implantation, age, sex, bearing types and THA indication. Of the 428 matched control THA cases, 93 had CT scans. In all, the CT scans from 149 cases (56 unstable, 93 stable) were analyzed to determine the acetabular cup's inclination and anteversion, and the femoral stem's anteversion. RESULTS: In the unstable THA group, cup inclination was 46.9°±7.4°, cup anteversion was 20.4°±10.8° and stem anteversion was 14.2°±9.9°. In the stable THA group, cup inclination was 44.9°±5.3° (P=0.057), cup anteversion was 22.1°±5.1° (P=0.009) and stem anteversion was 13.4°±4.4° (P=0.362). The optimal total anteversion (cup+stem) of 40-60° was achieved in 16.5% of unstable THA cases and 13.9% of stable THA cases, thus this parameter does not predict stability (odds ratio [OR] of 0.40, P=0.144). The cup was positioned in Lewinnek's safe zone in 44.6% of patients in the unstable group and 68.2% of those in the stable group (OR 3.74, P=0.003). A target zone defined as 40-50° inclination and 15-30° anteversion was better able to distinguish between unstable cases (23.2%) and stable cases (71.6%) resulting in an OR of 13.91 (P<0.001). DISCUSSION: Implant positioning was the only risk factor for instability found in this study. Moreover, our findings reinforce the theory put forward by other authors that Lewinnek's safe zone is not specific enough to differentiate between stable and unstable THA implantations. The target zone for acetabular cups proposed here (40-50° inclination and 15°-30° anteversion) is related to a lower risk of instability. This orientation can be used as a guide, but must be combined with other technical elements to optimize stability. By balancing stability and biomechanics, the 40-50° inclination and 15°-30° anteversion target zone redefines the optimal positioning window. LEVEL OF EVIDENCE: III case-control study.

High protein flexibility and reduced hydration water dynamics are key pressure adaptive strategies in prokaryotes.

Water and protein dynamics on a nanometer scale were measured by quasi-elastic neutron scattering in the piezophile archaeon Thermococcus barophilus and the closely related pressure-sensitive Thermococcus kodakarensis, at 0.1 and 40 MPa. We show that cells of the pressure sensitive organism exhibit higher intrinsic stability. Both the hydration water dynamics and the fast protein and lipid dynamics are reduced under pressure. In contrast, the proteome of T. barophilus is more pressure sensitive than that of T. kodakarensis. The diffusion coefficient of hydration water is reduced, while the fast protein and lipid dynamics are slightly enhanced with increasing pressure. These findings show that the coupling between hydration water and cellular constituents might not be simply a master-slave relationship. We propose that the high flexibility of the T. barophilus proteome associated with reduced hydration water may be the keys to the molecular adaptation of the cells to high hydrostatic pressure.

Specific impacts of beech and Norway spruce on the structure and diversity of the rhizosphere and soil microbial communities.

The impacts of plant species on the microbial communities and physico-chemical characteristics of soil are well documented for many herbs, grasses and legumes but much less so for tree species. Here, we investigate by rRNA and ITS amplicon sequencing the diversity of microorganisms from the three domains of life (Archaea, Bacteria and Eukaryota:Fungi) in soil samples taken from the forest experimental site of Breuil-Chenue (France). We discovered significant differences in the abundance, composition and structure of the microbial communities associated with two phylogenetically distant tree species of the same age, deciduous European beech (Fagus sylvatica) and coniferous Norway spruce (Picea abies Karst), planted in the same soil. Our results suggest a significant effect of tree species on soil microbiota though in different ways for each of the three microbial groups. Fungal and archaeal community structures and compositions are mainly determined according to tree species, whereas bacterial communities differ to a great degree between rhizosphere and bulk soils, regardless of the tree species. These results were confirmed by quantitative PCR, which revealed significant enrichment of specific bacterial genera, such as Burkholderia and Collimonas, known for their ability to weather minerals within the tree root vicinity.

Small diameter metal-on-metal total hip arthroplasty at 13 years - a follow-up study.

INTRODUCTION: Theoretically, the properties of second-generation metal-on-metal (MoM) bearings are better for wear, osteolysis and longevity. However, follow-up studies of more than 10 years are rare, in particular with hybrid fixation (cemented stainless steel stems and cementless cup), therefore we evaluated the results of this combination after a mean follow-up of 12.8 years: (1) to analyze the survival rate, (2) to compare it with the survival rate in the same series after 6.4 years (95.8% cup, 94.8% stem), (3) to evaluate clinical and radiographic outcome and (4) to analyze these failures. HYPOTHESIS: The number of revisions would increase after 10 years. MATERIALS AND METHODS: We evaluated 106 total hip arthroplasties (THA) (Cedior™ press-fit cup with cemented Acora™ (n=50) and Exafit™ (n=56) stems and 28mm Metasul™ bearings performed between January 1999 and December 2002. The survival rate was calculated by the Kaplan-Meier method. The clinical assessment included the Postel Merle d'Aubigné (PMA) and Oxford scores. The radiographic assessment evaluated radiolucencies and osteolysis on standard X-rays. A histological analysis was only performed during revision THA. RESULTS: After a mean 12.8 years of follow-up (10-16), 53 THA were reviewed in 48 patients. Thirteen THA revisions (14%) were performed including 11 aseptic revisions (5 stem fractures, 2 cases of impingement and 3 loosenings [1 bipolar and 3 cups] and one case of osteolysis). Overall survival, taking into account revision for aseptic loosening, was 87.6% (CI 95%=77.3 to 99.3%). The mean PMA and Oxford scores at the final follow-up were 17.6±0.8 points (16-18) and 16.5±5.2 points (12-38) respectively. The radiological follow-up mainly identified radiolucencies around the stem in Gruen zones 1 and 7 (17 and 21% respectively). DISCUSSION: The survival rate of hybrid MoM THA in this series decreased after 10 years and is lower than studies evaluating cementless THA with the 28-mm Metasul™ bearings (90.9 to 100% survival). Although the clinical results are satisfactory, survival is lower. However, the role of MoM bearings is relative in these failures, in particular because trunnionoses (stainless steel stem with 28-mm head), impingement and especially 5-stem fractures were the main causes of failure. LEVEL OF EVIDENCE: IV: retrospective study.

Unplanned return to theater: A quality of care and risk management index?

INTRODUCTION: Surgical quality and risk management is a major public health issue. The consequences of unplanned return to theater are social, occupational, financial and even legal. Unscheduled revision surgery is a major adverse event, resulting from serious complications - some of which are thought to be avoidable. The present study sought to assess and analyze the incidence of unplanned return to theater in an orthopedic surgery department. The study hypothesis was that some of the complications involved could be avoided. PATIENTS AND METHOD: A mixed retrospective-prospective study examined a consecutive series of 10,158 patients operated on in an orthopedic and traumatologic surgery department between January 2011 and December 2013. Patients undergoing revision surgery for reasons directly related to the primary procedure were analyzed. Patients were distributed among the following subgroups: infection, implant dislocation; hemorrhagic complication, mechanical complication, problem of primary technique, stiffness, wound healing disorder. Specific indicators of dysfunction liable to have contributed to onset of the complication were applied in each subgroup, to determine the avoidable or unavoidable nature of the event. RESULTS: Two hundred and twenty-four patients (2.2%) underwent revision surgery for reasons directly related to the primary procedure. One hundred and eight cases (48.2%) were considered to have been avoidable: 48 infections (21.4%), 27 implant dislocations (12%), 15 hemorrhagic complications (6.7%), 66 mechanical complications (29.5%), 35 technical problems at primary surgery (15.6%), 21 cases of stiffness (9.3%), and 12 cases of delayed wound healing (5.3%). Mean time to revision surgery was 2.7 ± 2.6 months. Extending the time-window to 1 year recruited extra cases: in 31.7% of cases, onset was after the 90th postoperative day, which is the usual deadline. The rate of unplanned return to theater was higher after unscheduled (traumatic: 3.2%) than scheduled surgery (1.7%, P < 0.001). CONCLUSION: Return to surgery in orthopedic and traumatologic surgery is underestimated. Annual incidence was 2.2%, and twice as high (3.2%) following traumatologic compared to scheduled surgery (1.7%). Analysis found that almost half the cases were avoidable. They represent a relevant and easily assessed indicator of treatment quality and associated risk management. A national or even international database in the form of an anonymous registry of revision surgeries would be useful.

Biostimulation to identify microbial communities involved in methane generation in shallow, kerogen-rich shales.

AIMS: The aim of the present study was to design and test a method allowing the detection and quantification of methanogenic consortia in organic-rich rocks to determine the potential of methane biotransformation. METHODS AND RESULTS: Methanogen numbers in the rock are often below the detection levels of quantification methods. Biostimulation was tested as a means to specifically increase bacterial and archaeal numbers above the detection levels in microcosms. Biostimulation reveals the presence of active heterotrophic and syntrophic bacterial consortia, methane accumulation and methanogens in one of four rock samples. Syntrophs and heterotrophs were dominated by Firmicutes, whereas archaeal diversity was limited to methanogens. Methane-producing microcosms were characterized by a higher Firmicutes diversity. CONCLUSIONS: Biostimulation is a reliable tool for detection of methanogenic consortia in organic-rich rocks. For routine and large scale experimentation, methane accumulation monitoring after biostimulation appears as the most time, work and cost efficient approach to detect the presence of active methanogenic consortia. SIGNIFICANCE AND IMPACT OF THE STUDY: We report for the first time the presence of live methanogenic consortia in organic-rich shales and their ability to mineralize the rock into methane. This approach will be instrumental to quantify the potential of these rocks to produce methane as a novel energy source.

Correlation of the abundance of betaproteobacteria on mineral surfaces with mineral weathering in forest soils.

Pyrosequencing-based analysis of 16S rRNA gene sequences revealed a significant correlation between apatite dissolution and the abundance of betaproteobacteria on apatite surfaces, suggesting a role for the bacteria belonging to this phylum in mineral weathering. Notably, the cultivation-dependent approach demonstrated that the most efficient mineral-weathering bacteria belonged to the betaproteobacterial genus Burhkolderia.

Distinct ectomycorrhizospheres share similar bacterial communities as revealed by pyrosequencing-based analysis of 16S rRNA genes.

Analysis of the 16S rRNA gene sequences generated from Xerocomus pruinatus and Scleroderma citrinum ectomycorrhizospheres revealed that similar bacterial communities inhabited the two ectomycorrhizospheres in terms of phyla and genera, with an enrichment of the Burkholderia genus. Compared to the bulk soil habitat, ectomycorrhizospheres hosted significantly more Alpha-, Beta-, and Gammaproteobacteria.

Fractionation of stable zinc isotopes in the zinc hyperaccumulator Arabidopsis halleri and nonaccumulator Arabidopsis petraea.

Zn isotope fractionation may provide new insights into Zn uptake, transport and storage mechanisms in plants. It was investigated here in the Zn hyperaccumulator Arabidopsis halleri and the nonaccumulator A. petraea. Plant growth on hydroponic solution allowed us to measure the isotope fractionation between source Zn (with Zn(2+) as dominant form), shoot and root. Zn isotope mass balance yields mean isotope fractionation between plant and source Zn Δ(66)Zn(in-source) of -0.19 ± 0.20‰ in the nonaccumulator and of -0.05 ± 0.12‰ in the hyperaccumulator. The isotope fractionation between shoot Zn and bulk Zn incorporated (Δ(66)Zn(shoot-in)) differs between the nonaccumulator and the hyperaccumulator and is function of root-shoot translocation (as given by mass ratio between shoot Zn and bulk plant Zn). The large isotope fractionation associated with sequestration in the root (0.37‰) points to the binding of Zn(2+) with a high affinity ligand in the root cell. We conclude that Zn stable isotopes may help to estimate underground and aerial Zn storage in plants and be useful in studying extracellular and cellular mechanisms of sequestration in the root.

[Assisted Reproductive Technologies in HIV patients: a comprehensive review of indications, techniques and results]. / Assistance médicale à la procréation et VIH: revue des indications, techniques et résultats.

Assisted Reproductive Technologies (ART) are authorized in France in couples infected by the human immunodeficiency virus (HIV) since the French legislation of May 10th, 2001. The goals are to reduce the risk of viral transmission between partners and to treat an underlying infertility. The classical techniques are used: IUI, IVF or ICSI, but all of them must be done in specifically authorized laboratories. ART outcome is favourable when only the man is infected, but seems to be less favourable when the woman is infected. Management of pregnancy planning should first propose to women infected by HIV, self inseminations when possible, and if needed, a quick ART treatment as some studies showed ovarian function alterations in HIV women. When the man is infected, IUI would be first proposed. Thousands of HIV positive male partners have used ART in Europe and no contamination has been reported so far. Approximately half of couples with one or both partners infected can hope to have a child through the ART process.

Risks relating to posterior 2-portal arthroscopic subtalar arthrodesis and articular surfaces abrasion quality achievable with these approaches: a cadaver study.

INTRODUCTION: Many techniques for arthroscopic subtalar arthrodesis have been described since 1985. The procedure can be challenging because posterior and anterior portals are used conjointly with distraction. A posterior 2-portal approach was described in 2000. HYPOTHESIS: The goal of this study was to evaluate the quality of the freshening that can be achieved in the posterior subtalar joint using this approach. Does a posterior 2-portal approach allow for a complete freshening of the posterior subtalar joint? MATERIAL AND METHODS: Freshening was performed through an arthroscopic posterior 2-portal approach on 10 cadavers. The quality of bone freshening and proximity of the neurovascular structures to the posterior portals were subsequently evaluated by dissection. RESULTS: There was one partial laceration of the sural nerve. The posteromedial portal was 6.8mm (95% CI: 4.4 to 9.2) away from the posterior tibial vascular pedicle. The entire talar and calcaneal articular surfaces of the posterior subtalar joint were freshened. In eight of 10 cases (95% CI: 48 to 95%), the posteromedial process of the talus prevented contact between fragments. DISCUSSION: This study showed that the entire posterior subtalar joint can be freshened through an arthroscopic posterior 2-portal approach with little morbidity. LEVEL OF EVIDENCE: Level IV.

Component positioning in primary total hip replacement: a prospective comparative study of two anterolateral approaches, minimally invasive versus gluteus medius hemimyotomy.

INTRODUCTION: One factor of implant survivorship in total hip replacement (THR) is the quality of implant choice and positioning. The purported advantages of minimally invasive approaches are faster recovery, shorter hospital stay and less per-operative blood loss. On the other hand, there have been many reports of higher complication rates, and doubts as to the quality of implant positioning. HYPOTHESIS: The quest to minimize tissue damage is at the cost of THR positioning quality. OBJECTIVES: To assess implant positioning in a prospective comparative continuous multicenter series. PATIENTS AND METHODS: Between 2008 and 2009, a prospective comparative study was conducted on a continuous series of 141 THRs. Ninety-two were performed in two centers, using a minimally invasive Watson-Jones approach; the other 49, performed in a 3rd center, used an anterolateral approach with anterior hemimyotomy. The surgeons were in all cases experienced in their technique. Short-term follow-up comprised clinical and functional (Postel Merle d'Aubigné (PMA), Harris, SF12, WOMAC) and biological assessment (serum creatine phosphokinase (CPK), myoglobinemia, hematocrit) and analysis of complications and of implant positioning on X-ray and CT-scan. RESULTS: On the Watson-Jones approach, surgery time was longer; day-1 analgesic administration was lower; PMA, Harris and WOMAC scores were better at 6 weeks; and CPK levels were lower at 24 and 48hours. There were no significant differences on the other clinical and biological criteria. Implant positioning analysis revealed significantly greater combined anteversion and greater variation in acetabular inclination mean with the Watson-Jones approach, but no differences in cup positioning, femoral stem positioning, or limb length discrepancy. DISCUSSION: The minimally invasive Watson-Jones approach provided faster recovery and less muscular damage. However, implant positioning was less precise in terms of acetabular cup inclination. LEVEL OF EVIDENCE: Level III. Prospective, comparative, non-randomized.

Monitoring microbial redox transformations of metal and metalloid elements under high pressure using in situ X-ray absorption spectroscopy.

X-ray absorption spectroscopy is a well-established method for probing local structural and electronic atomic environments in a variety of systems. We used X-ray absorption near-edge structure (XANES) spectroscopy for monitoring in real-time conditions selenium reduction in situ in live cultures of Shewanella oneidensis MR-1 under high hydrostatic pressure. High-quality XANES data show that Shewanella oneidensis MR-1 reduces selenite Se(IV) to red elemental selenium Se(0) up to 150 MPa without any intermediate redox state. MR-1 reduces all selenite provided (5-10 mM) between 0.1 and 60 MPa. Above 60 MPa the selenite reduction yield decreases linearly with pressure and the activity is calculated to stop at 155 ± 5 MPa. The analysis of cultures recovered after in situ measurements showed that the decrease in activity is linked to a decrease in viability. This study emphasizes the promising potential of XANES spectroscopy for real-time probing in situ microbial redox transformations of a broad range of metal and metalloid elements in live samples, including under high hydrostatic pressure.

[Informations for the infertile couple]. / Informations à donner au couple infécond.

The aim of the first consultation related to infertility is supposed to be the optimization of all factors that can increase the chances of pregnancy: more frequent sexual intercourse during the fertility windows; lifestyle modifications (better diet, decreased exposure to tobacco or other toxics); older couples can enjoy the same advice but should be proposed a quicker medical support. Maternal preconceptional advice must be transmitted. A testicular cancer must always be excluded in infertile men, while the risk of hormone-dependent cancers in infertile women remains undetermined. With the results of this first consultation, couples will generally be proposed the best solution to achieve their parental project: ovarian stimulation assisted reproductive technology (IUI, IVF or ICSI) or adoption.