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In a menopausal woman scheduled for curative surgery for pelvic organ prolapse (POP) by sacral colpopexy (SC), the question of concomitant hysterectomy is frequently considered by the surgeon. The risk of endometrial cancer (EC) exists in this population, and increases with age and body mass index. The French college of gynecologists and obstetricians (CNGOF) decided to issue good practice guidelines on subtotal hysterectomy (SH) for postmenopausal women scheduled for SC for POP.

Up to now, the possible occurrence of a cationic ordering on the tetrahedral sublattices of stoichiometric double scheelite-type oxides was not settled, with somewhat contradictory X-ray diffraction and optical measurements [Blasse, G. J. Inorg. Nucl. Chem. 1968, 30, 2091]. Using two different synthesis routes, both ordered and disordered forms of fergusonite La2SiMoO8were prepared. The crystal structure of the ordered form was determined using powder X-ray and neutron diffraction, which clearly evidence a tridimensional ordering between [SiO4] and [MoO4] tetrahedra. The crystal chemistry of ordered double sheelite-type LaIII2(SiIVO4)(MoVIO4) can be seen as an intermediate between those of simple regular scheelite or fergusonite LnIII(NbVO4) and of ordered triple scheelite BiIII3(FeIIIO4)(MoVIO4)2. The structure of the disordered La2SiMoO8phase was analyzed using powder X-ray diffraction. A few small and larger diffraction peaks or bumps are observed in addition to the sharper peaks of a simple fergusonite cell. DIFFaX and FAULTS programs helped showing that these faint peaks originate from stacking faults between 2D ordered layers. The intermediate 2D–3D nature of SiO4/MoO4ordering in seemingly disordered compounds might explain the previous discrepancy between optical and X-ray diffraction measurements.

L’étude LACC (Laparoscopic Approach to Cervical Cancer Trial), parue en 2018 a décrit des résultats oncologiques en faveur de la laparotomie comparativement à la voie mini-invasive dans la prise en charge des cancers du col localisés. Notre but était d’évaluer l’impact de cette étude sur les pratiques chirurgicales en France.

The A7B7O30structural type is a columnar-perovskite-type arrangement originally evidenced in La7Mo7O30[Goutenoire et al. J. Solid State Chem. 1999, 142, 228], an intermediate reduction product of fast oxide-ion conductor La2Mo2O9. Subsequently, this new structural family has been extended to La7W6+4M5+3O30(M = Nb, Ta) [Goutenoire et al. J. Solid State Chem.2005, 178, 2811]. Here we show that it is possible to further extend the solid solution through partial substitution of hexavalent tungsten by di-, tri-, or tetravalent transition metals. The general formula is La3+7W6+7-xMm+xO30with x= 3/(6 – m), or m= 6 – 3/x. Single phase samples with Mm+= Zn2+, Fe3+, and Ti4+have been prepared, and their crystal structure refined using X-ray powder diffraction. In the structure, the transition metal with lower valence is preferentially located in the octahedral site shared by consecutive trans-connected perovskite cages, whose diagonal runs along the threefold axis of the structure. Close similarities are noticed with the cationic repartition and distortion of coordination polyhedra in compounds belonging to the AnBnO3n+2series of layered perovskites. A rationale is proposed, which includes the A7B7O30structural type as a subsequent 1D step to the 3D → 2D AnBnO3n+2scheme of perovskite framework slicing by progressive oxygen insertion through decreasing n.

Safety of the uterine manipulator (UM) within endometrial cancer (EC) surgery is being questioned. Its use might be one of the issues for potential tumor dissemination during the procedure, especially in the case of uterine perforation (UP). No prospective data on this surgical complication, nor on the oncological consequences exist. The aim of this study was to assess the rate of UP while using UM when performing surgery for EC and the impact of UP on the choice of adjuvant treatment.

Yersinia pseudotuberculosiscan replicate inside macrophages by hijacking autophagy and blocking autophagosome acidification. In bone marrow-derived macrophages, the bacteria are mainly observed inside double-membrane vacuoles positive for LC3, a hallmark of autophagy. Here, we address the question of the membrane traffic during internalization of Yersiniainvestigating the role of vesicle- associated membrane proteins (VAMPs). First, we show that as in epithelial cells, Yersinia pseudotuberculosisreplicates mainly in nonacidic LC3-positive vacuoles. Second, in these cells, we unexpectedly found that VAMP3 localizes preferentially to Yersinia-containing vacuoles (YCVs) with single membranes using correlative light-electron microscopy. Third, we reveal the precise kinetics of VAMP3 and VAMP7 association with YCVs positive for LC3. Fourth, we show that VAMP7 knockdown alters LC3′s association with single-and multimembrane-YCVs. Finally, in uninfected epithelial cells stimulated for autophagy, VAMP3 overexpression and knockdown led respectively to a lower and higher number of double-membrane, LC3-positive vesicles. Hence, our results highlight the role that VAMPs play in selection of the pathways leading to generation of ultrastructurally different LC3 compartments and pave the way for determining the full set of docking and fusion proteins involved in Yersinia pseudotuberculosis’ intravesicular life cycle.

The vibrational properties of β-SnWO4at center of the Brillouin zone are investigated by Raman at low temperature and infrared spectroscopies in connexion with ab initio calculations. In this cubic structure archetype of new materials with ionic conductivity properties, all 29 optical modes predicted by group theory are Raman-active. All lines have been unambiguously identified on the basis of depolarization ratio measurements. The phonon spectrum is calculated at the center of the Brillouin zone by GGA pseudopotentials within the PWSCF/QE suite. A remarkable agreement is obtained with the experimental frequencies, and a fairly good one is also observed with the Raman scattering cross sections calculated using LDA pseudopotentials for the internal modes of WO42–tetrahedra and the lattice modes as well. All Raman lines are assigned for the first time, and the normal coordinates characteristics are described. The whole results give a large credit to the calculation of the phonon spectra in this structural arrangement with such ions. The phonon density of states is deduced, and the characteristics are explained on the basis of the phonon dispersions curves along the [ξ00] and [ξξ0] high-symmetry directions of the Brillouin zone.

Rapid blood perfusion is critical for postimplantation survival of thick, prevascularized bioartificial tissues. Yet the mechanism by which implanted vascular networks inosculate, or anastomose, with the host vasculature has been unknown, making it difficult to develop optimized strategies for facilitating perfusion. Here we show that implanted vascular networks anastomose with host vessels through a previously unidentified process of “wrapping and tapping” between the engrafted endothelial cells (ECs) and the host vasculature. At the host-implant interface, implanted ECs first wrap around nearby host vessels and then cause basement membrane and pericyte reorganization and localized displacement of the underlying host endothelium. In this way, the implanted ECs replace segments of host vessels to divert blood flow to the developing implanted vascular network. The process is facilitated by high levels of matrix metalloproteinase-14 and matrix metalloproteinase-9 expressed by the wrapping ECs. These findings open the door to new strategies for improving perfusion of tissue grafts and may have implications for other physiologic and pathologic processes involving postnatal vasculogenesis.

The mixed ionic–electronic conductivity under dilute hydrogen, the stability and the catalytic activity under propane:air type mixtures of a series of LAMOX oxide‐ion conductors have been studied. The effect of exposure to dilute hydrogen on the conductivity of the β‐La2(Mo2 –yWy)O9series at 600 °C depends on tungsten content: almost negligible for the highest (y= 1.4), it is important for La2Mo2O9(y= 0). In propane:air, all tested LAMOX electrolytes are stable at 600–700 °C, but get reduced when water vapour is present. La2Mo2O9is the best oxidation catalyst of the series, with an activity comparable to that of nickel.

Native tissue cystocele repair has been the cornerstone of prolapse surgery, especially since the learned societies warned clinicians and patients about serious mesh related complications and recommend a vaginal route without prosthesis in first intention. Surgical techniques mainly consist in anterior colporraphy, vaginal patch plastron and para vaginal repair. However, in case of vaginal patch plastron, the vagina left in contact with the bladder is a material of much better quality than colporraphy alone. The multiplication of native tissues, generating post-operative fibrosis, associated with anchorage on a strong ligamentous structure, allows to expect better outcomes compared to anterior colporraphy. Indeed, vaginal plastron corrects median cystoceles with a vaginal strip as well as lateral cystoceles thanks to bilateral paravaginal suspension. Thereby, vaginal patch plastron appears to be a good compromise between the 3 autologous techniques with median and paralateral repair

Demixing/recombination and metastability phenomena are observed in the La2–2xCa2xMo2O9–x solid solutions ofLAMOX-type fast oxide-ion conductors (0.005 ≤ x ≤ 0.05). The demixing process is more visible at high Ca content. The effects of composition, sample shape (powders with twodegrees of fineness, ceramic pellets, single crystals) and thermal history are studied by using high-temperature X-ray diffraction, differential scanning calorimetry (DSC) and polarized microscopy. All these parameters are shown to have an influence on the stability of, and transformations between, the ordered α and the disordered β forms of the LAMOX compounds. Powder samples with low Ca content (x = 0.01, 0.02) have been stabilized in the α form, and powder samples with higher Ca content (x = 0.03, 0.04, 0.05) are in the β form. Upon heating, the low-Ca-content compounds (x = 0.01 and x = 0.02) exhibit the α/β transition, whereas those with higher Ca content (x = 0.03 and x = 0.04) show a succession of β/α/β phase transformations (metastability of the β form). The compound with the highest Ca content (x = 0.05) remains in the β form over the whole thermal range. Upon cooling, all samples exhibit the β/α phase transition. When x = 0.04, powder annealing suppresses all the phase transformations upon heating, but not the β/α transition upon cooling, whereas sample shaping/sintering as a pellet stabilizes the β form over the whole thermal range upon heating and cooling. Single crystals with compositions x = 0.005 and x = 0.025 can be obtained either in the α or in the β form by slow cooling or by quenching, respectively. In these oxide-ion conductors with a high concentration of point defects, internal or external stress appears to strongly affect the vacancy equilibrium but not the demixing/recombination phenomenon.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The effects of partial substitutions of Bi by La, Gd, and Y on the structure, thermal expansion and transport properties of modulated fluorite-type Bi5NbO10were investigated using X-ray thermodiffraction, alternative current impedance spectroscopy and the Wagner polarization method. Through conventional solid-state syntheses, the solid solutions Bi5−xLnxNbO10exist up to about x∼ 0.25 for La, and to x∼ 0.5 for Gd and Y. A doubling of their thermal expansion coefficient is observed above 540 °C. The type-II incommensurate modulation of these phases is correlated to the nature and amount of substitute, and disappears above 800 °C. Except for Bi5NbO10, which appears to be a pure ionic conductor, most of the solid solutions exhibit mixed conductivity with predominant ionic transport. Partial Gd and Y substitutions favor electron conductivity in the low temperature range, probably due to bismuth partial oxidation.

The crystal structure of the solid solutions La2Mo2-yCryO9 (y ≤ 0.5) and La2Mo2-yWyO9 (y ≤ 1.4) has been studied using X-ray and neutron powder diffraction. These two series of lanthanum molybdates, which belong to the LAMOX family of fast oxide-ion conductors, exhibit a different structural behavior depending on the substituting element. The Cr series follows a regular Vegard-type evolution of crystallographic parameters. However, the behavior of the W series is different, the lattice constant varying in a nonlinear fashion with substitution level, resulting in a smaller cell volume for higher tungsten contents, despite the larger ionic radius of tungsten. Two main structural effects are evidenced:  a variation in the distribution of ligands around tungsten, made apparent through the changing balance of oxygen O2 and O3 site occupancies along the series, and a nonlinear evolution of interatomic distances and angles involving the O1 oxygen site. An alternative structural description, based on [O1La3Mo] anti-tetrahedra, is proposed in order to better account for the transport properties of these materials.

Endothelial cells display remarkable heterogeneity in different organs and vascular beds. Although many studies suggest that tissues “speak” to endothelial cells, endothelial cell diversity remains poorly characterized at the molecular level. Here, we describe a novel strategy to characterize tissue-specific endothelial cell phenotypes and to identify endothelial cell genes that are under the control of the local microenvironment. By comparing post-capillary high endothelial venule endothelial cells (HEVECs), freshly isolated from human tonsils without any cell culture step, with HEVECs cultured for 2 days, we found that HEVECs rapidly lost their specialized characteristics when isolated from the lymphoid tissue microenvironment. Striking changes occurred as early as after 48 hours, with complete loss of the postcapillary venule–specific Duffy antigen receptor for chemokines (DARCs) and the HEV-specific fucosyltransferase Fuc-TVII. DNA microarray analysis identified several other candidate HEV genes that were rapidly down-regulated ex vivo, including type XV collagen, which we characterized as a novel, abundant HEV transcript in situ. Together, our results demonstrate that blood vessel type–specific and tissue-specific characteristics of endothelial cells are under the control of their microenvironment. Therefore, even short-term primary cultures of human endothelial cells may not adequately mimic the differentiated endothelial cell phenotypes existing in vivo.

Endothelial cells display remarkable heterogeneity in different organs and vascular beds. Although many studies suggest that tissues “speak” to endothelial cells, endothelial cell diversity remains poorly characterized at the molecular level. Here, we describe a novel strategy to characterize tissue-specific endothelial cell phenotypes and to identify endothelial cell genes that are under the control of the local microenvironment. By comparing post-capillary high endothelial venule endothelial cells (HEVECs), freshly isolated from human tonsils without any cell culture step, with HEVECs cultured for 2 days, we found that HEVECs rapidly lost their specialized characteristics when isolated from the lymphoid tissue microenvironment. Striking changes occurred as early as after 48 hours, with complete loss of the postcapillary venule–specific Duffy antigen receptor for chemokines (DARCs) and the HEV-specific fucosyltransferase Fuc-TVII. DNA microarray analysis identified several other candidate HEV genes that were rapidly down-regulated ex vivo, including type XV collagen, which we characterized as a novel, abundant HEV transcript in situ. Together, our results demonstrate that blood vessel type–specific and tissue-specific characteristics of endothelial cells are under the control of their microenvironment. Therefore, even short-term primary cultures of human endothelial cells may not adequately mimic the differentiated endothelial cell phenotypes existing in vivo.

A series of optimised materials in the family with parent compound La₂Mo₂O₉ have been studied using the isotope exchange depth profile technique and SIMS analysis. The data collected indicate that the oxide ion diffusion coefficients in both the parent compound and optimised materials are significantly higher than those reported for any of the fluorite structured electrolyte materials, with a peak value for the La_1.7Gd_0.3Mo₂O₉ composition of 1.41 × 10−6 cm2 s−1 at 800 °C. Further, it was found that the substitution of isotopic oxygen into the ceramic was limited in dry atmospheres but significantly enhanced in a H₂18O/16O atmosphere, in common with recent reports on the diffusion/exchange behaviour of the BIMEVOX class of oxide ion conductors.

A series of optimised materials in the family with parent compound La2Mo2O9have been studied using the isotope exchange depth profile technique and SIMS analysis. The data collected indicate that the oxide ion diffusion coefficients in both the parent compound and optimised materials are significantly higher than those reported for any of the fluorite structured electrolyte materials, with a peak value for the La1.7Gd0.3Mo2O9composition of 1.41 × 10−6cm2s−1at 800 °C. Further, it was found that the substitution of isotopic oxygen into the ceramic was limited in dry atmospheres but significantly enhanced in a H218O16O atmosphere, in common with recent reports on the diffusionexchange behaviour of the BIMEVOX class of oxide ion conductors.

The substitutional range and cell parameter evolution of fast oxide-ion conductors La_2−xR_xMo_2−yW_yO₉ (R = Nd, Gd) are investigated. In the whole series, the cubic β-La₂Mo₂O₉ structural type is stabilized at room temperature. The effects on reducibility of both single and double substitutions are presented. Lanthanum substitution by rare earth appeared to be responsible for an increase in the reducibility and a strong but reversible amorphization under dilute hydrogen. On the contrary, the favourable role of tungsten on the compound stability under reducing conditions is evidenced: it depletes oxygen loss while making the La₂Mo₂O₉ structural type less affected by it.

The substitutional range and cell parameter evolution of fast oxide-ion conductors La2−xRxMo2−yWyO9R Nd, Gd are investigated. In the whole series, the cubic β-La2Mo2O9structural type is stabilized at room temperature. The effects on reducibility of both single and double substitutions are presented. Lanthanum substitution by rare earth appeared to be responsible for an increase in the reducibility and a strong but reversible amorphization under dilute hydrogen. On the contrary, the favourable role of tungsten on the compound stability under reducing conditions is evidenced: it depletes oxygen loss while making the La2Mo2O9structural type less affected by it.

The room-temperature crystal structure of (V1-xMox)2O3 (0 ≤ x ≤ 0.20) is studied in detail, using combined X-ray and neutron powder diffraction. Substitution of vanadium by molybdenum tends to regularize the atomic stacking and reduce octahedral distortion. Cation−anion distances increase with x, in a way that is consistent with a trivalent oxidation state of both molybdenum and vanadium. Quite unexpectedly, such an octahedral and volume expansion is accompanied by a regular decrease of nearest- and next-nearest-neighbor cation−cation distances. This behavior is discussed in terms of a possible progressive establishment of metal−metal bonding and with respect to the stabilization of the metallic phase.

Fluorine-doped lanthanum molybdates with the nominal formula La2Mo2O9-0.5xFx (x = 0.20−0.30) were synthesized and characterized using powder X-ray diffraction, electron diffraction, differential thermal analysis, and impedance spectroscopy. Comparisons are made with the parent anionic conductor system La2Mo2O9. From our studies two distinct regimes with two different ranges of “x” values (range 1:  including 0.00 ≤ x ≤ 0.12; range 2:  including 0.18 ≤ x ≤ 0.30) could be delineated for the La2Mo2O9-0.5xFx compositions. Electron diffraction study on selected samples showed that x = 0.20 and 0.30 compositions (range 2) have a 3 × 3 × 3 supercell, different from the 2 × 3 × 4 supercell observed in the x = 0.00 and 0.10 compositions (range 1). All the fluorine-doped lanthanum molybdates show a first-order phase transition. With the increase in the fluorine content the transition temperature decreases in both ranges 1 and 2. Below the transition temperature, compositions belonging to range 2 have much lower conductivity when compared to that of those belonging to range 1. The activation energy as obtained from the conductivity data is higher for the fluorine-doped lanthanum molybdates compared to the parent compound La2Mo2O9. Above the transition temperature the conductivity of the fluorine-doped lanthanum molybdate is higher than that of La2Mo2O9. Significantly our study presents the possibility of using fluorine substitution as a technique to increase the anionic conductivity in oxide ion conductors with favorable structural features (like in the case of La2Mo2O9) by decreasing the transition temperature of the first-order (order−disorder type) phase transition.

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The structure of La2Mo4O15has been determined from both high resolution X-ray and neutron powder diffraction data. This molybdate crystallizes in a monoclinic space group P21/nwith cell parameters a=9.0357(2) Å, b=12.7737(2) Å, c=10.6408(2) Å, β=90.2491(6)°. The structure consists of molybdenum octahedra [MoO6] and tetrahedra [MoO], and lanthanum polyhedra [LaO9]. Molybdenum polyhedra are connected together, forming large units [Mo6O22], isolated by lanthanum polyhedral chains. This structure is compared with those of already known lanthanide molybdates with formula Ln2Mo4O15(Ln=Ce, Ho).

A new family of fast O²⁻ conductors, which exhibit anionic conductivity comparable to that of stabilised zirconia, is presented. The parent compound of this new family, hereafter called LAMOX, is lanthanum molybdate La₂Mo₂O₉. Various substitutions have been attempted: on the lanthanum site (La_{2 − x}A_x)Mo₂O₉ with A = Sr, Ba, K, or Bi; on the molybdenum site La₂(Mo_{2 − x}B_x)O₉ with B = Re, S, W, Cr and V; and on the oxygen site with fluorine. Most of these substitutions suppress the phase transition which occurs in La₂Mo₂O₉ around 580 °C from a low temperature α form to a high temperature (more conducting) β form, and stabilise the β form at room temperature. Several members of the LAMOX series are studied through X-ray and neutron diffraction, and conductivity measurements. Large O²⁻ thermal factors and local static disorder agree well with the anionic nature of the conductivity. Partly vacant sites with short inter-site distances suggest a most probable conduction path with tridimensional character.

The microstructure of NdNiO3thin films deposited on Si (100) has been investigated by high resolution electron microscopy. Deposition at 250 °C and 600 °C and several annealing at high temperature under oxygen pressure were performed. Depending on the deposition temperature and annealing conditions, different texture and microstructure were observed. Relationships between microstructure and transport properties are discussed. The differences of grain boundaries are suggested to be responsible for the difference in transport properties of the films.

The microstructure of NdNiO$_3$ thin films deposited on Si (100) has been investigated by high resolution electron microscopy. Deposition at 250 $^{\circ}$C and 600 $^{\circ}$C and several annealing at high temperature under oxygen pressure were performed. Depending on the deposition temperature and annealing conditions, different texture and microstructure were observed. Relationships between microstructure and transport properties are discussed. The differences of grain boundaries are suggested to be responsible for the difference in transport properties of the films.

The coronavirus SARS-CoV-2 (COVID-19) pandemic has put tremendous pressure on the French healthcare system. Almost all hospital departments have had to profoundly modify their activity to cope with the crisis. In this context, the surgical management of cancers has been a topic of debate as care strategies were tailored to avoid any delay in treatment that could be detrimental to patient wellbeing while being careful not to overload intensive care units.

A new mixed valence molybdate, La7Mo7O30, first prepared by high energy ball milling, has been successfully synthesized by controlled hydrogen reduction of La2Mo2O9. Its original crystal structure was determined from X-ray and neutron powder diffraction (space groupR3;a=b=17.0051(2) Å,c=6.8607(1) Å;Z=3; reliability factors:Rp=0.081,Rwp=0.091,χ2=3.1,RBragg=0.049,RF=0.033). It consists in the hexagonal stacking of individual cylinders of perovskite-type arrangement. These cylinders are built up from perovskite cages sharing corners in trans-position along their diagonal axis. Two different mixed-valence molybdenum sites coexist, with more (Mo+5.75) or less (Mo+4.5) distorted octahedral environments. Lanthanum atoms are located within the perovskite cages and around them, very close to their regular positions in the perovskite structure. Lanthanum and molybdenum atoms thus form two rows of almost perfect cubes, shifted from each other byc/2. An electron microscopy study revealed the defect-free cationic and octahedral arrangements in the (a,b) plane.

Thallium metaniobate, Tl2Nb2O6, belongs to the cubic pyrochlore structural type (space group Fd3m). It is demonstrated by TGA, chemical analysis, and X-ray thermodiffractometry that it gives a continuous solid solution Tl2Nb2O6+x(0 ≤ x≤ 1) under oxidation; the cubic pyrochlore structure is maintained with a continuous decreasing unit cell edge: xoxide ions being progressively incorporated into the network while xTl3+ions substitute to xTl+ones. Rietveld refinements of X-ray powder diffraction data reveal that, in the classical model of the pyrochlore structure, Tl+and Tl3+are disordered on half of the 32epositions for 0 ≤ x< 0.5 and on the 16dones for 0.5 < x≤ 1. Bond valence calculations are in good agreement with the decrease in the splitting of Tl cations from 32eto 16dpositions when xincreases, provided that a correlation exists between oxygen insertion and the Tl3+distribution: each extra oxygen O' oxidizes one of its closest Tl neighbors to +3 while the three remaining monovalent Tl cations are repelled.

Hitherto unknown NH4FePO4F has been isolated by low-temperature hydrothermal synthesis. It is orthorhombic and acentric (space group Pna21(No. 33); a= 12.993(3) Å, b= 6.468(1) Å, c= 10.640(3) Å, V= 894.2(6) Å3, Z= 8). This compound belongs to the KTiOPO4(KTP) structure type, with a strict O-F ordering, the Ti-O short bond in KTP being replaced by a Fe-F bonding. The two iron sites, clearly evidenced by Mössbauer spectroscopy, correspond to two different local situations with 2 F-in cisposition for Fe(1) and in transposition for Fe(2). With such a configuration, the main magnetic coupling probably occurs within the chains of octahedra via Fe-F-Fe superexchange interactions only, like in AFeF5and A2FeF5compounds in which the Néel temperature is close to 10 K. However, the high magnetic transition temperature of NH4FePO4F (45(1) K) shows that the influence of super-superexchange coupling is rather important in this compound.

The title compounds were prepared from a mixture of 1 M₂O₃ (M = Ga or Al), 1 P₂O₅, 2 NH₄F, 1 hexamethylenetetramine, and 80 H₂O by hydrothermal synthesis at 180°C. Their crystal structure was determined by single-crystal X-ray diffraction. They crystallize in space group P2₁2₁2₁, Z = 8, with cell parameters a = 9.593(2) Å, b = 9.742(2) Å;, c = 9.981(2) Å; and a = 9.416(8) Å;, b = 9.563(5) Å;, c = 9.933(4) Å;, for M = Ga and Al, respectively. It appears that the aluminophosphate had previously been prepared and called AlPO₄-CJ2, but was poorly characterized. The crystal structure of these compounds can be described as a three-dimensional network of PO₄ tetrahedra sharing vertices with triangular bipyramids MX₅ and octahedra MX₆ (X = O²-, OH ^- or F^-). These polyhedra form eight-membered rings and delimit channels in which ammonium groups occupy two types of sites. Depending on M, fluorine atoms occupy one or two different sites, either in full occupancy or in statistical occupancy with hydroxyl groups. Descriptions of the structures are presented, as well as structural comparisons with morinite and minyulite. Copyright 1993, 1999 Academic Press

During the germination of Physarum spherules, increases have been observed, at the same moment, in the level of in vivo transcriptional activity as measured by [3H] uridine incorporation, and the accessibility of DNA for ethidium bromide staining as shown by flow cytometric measurements. We suppose that the changes observed in these two processes are due to a difference in chromatin organization between the first and the second period of the premitotic germination stage. In the second period, the four nucleosome core histories are synthesized in the absence of DNA replication and may correspond to a replacement of spherulation histone variants by plasmodial histone types in nucleosomes. The synthesis of historic H4 clearly distinguishes the second period of the premitotic germination stage from a growing plasmodium G2 phase, though nuclei exhibit a G2 phase DNA content. The same pattern of histone synthesis has been found during the cell cycle following the first mitosis after germination and the growing plasmodium cell cycle, with a synthesis of two histories H2B and H2A and the high mobility group (HMG)-like protein AS3 during the G2 phase, i.e. in the absence of DNA synthesis.