Ulcer of Lipschutz, a rare and unknown cause of genital ulceration

Acute genital ulcers are painful and distressing to women. Lipchutz Ulcer is an uncommon disease that typically occurs in sexually inactive young women. The main differential diagnosis are sexually-transmitted or non-infectious diseases which cause genital or oro-genital ulcerations. This article aims to review the diagnosis of acute genital ulcers and, through a rare case of acute genital ulcerations, to discuss diagnostic procedures.

A reversible posterior leucoencephalopathy syndrome including blindness caused by preeclampsia

Complications of (pre)eclampsia may involve multiple systems and organs. Neurological symptoms may occur. Visual symptoms concern up to 25% the of patients with severe preeclampsia and 50% of the patients with eclampsia. An uncommon effect of severe preeclampsia is sudden blindness. Blindness may be part of a clinical and radiological presentation named Posterior Reversible Encephalopathy Syndrome (PRES). PRES may lead to permanent neurological deficit, recurrences or death. We report the case of a 24-year-old Caucasian patient, gravida 5 para 2 who developed preeclampsia and PRES complicated with blindness at 32 weeks of gestation. Optimal care allowed visual symptoms to resolve within 24 hours and a favourable maternal outcome and no long- term sequelae. We describe different causes and manifestations of PRES and highlight the need for immediate care in order to optimize the chance of symptoms reversibility.

Revisiting silicate substituted hydroxyapatite by solid-state NMR

Silicon-substituted hydroxyapatite (Si-HAp) has shown promising properties such as high-bone remodeling around implants. So far, the techniques used for the structural characterization of the Si-HAp have given indirect evidence of the presence of silicon inside the structure (by X-ray and neutron diffraction). In this paper, we focus on Si-HAp derivatives obtained by a precipitation method (widely described in the literature). We demonstrate here by solid-state NMR spectroscopy that only a fraction of the silicon atoms are incorporated into the HAp lattice in the form of Q(0) (SiO(4) (4-)) species, for 4.6 wt% Si-HAp. A large amount of silicate units are located outside the HAp structure and correspond to silica-gel units. All results were established through (29)Si MAS, (1)H -->(29)Si CP MAS and T(1)rho((1)H) edited (1)H -->(29)Si CP MAS experiments. This last pulse scheme acted as a powerful editing sequence, leading to unambiguous spectroscopic conclusions, concerning the location of the SiO(4) (4-) moieties.

[Erythema multiforme caused by a Mycoplasma infection: a case report]

Erythema multiforme (EM) is an immune-mediated disease categorized into EM minor and EM major, also called Stevens-Johnson syndrome (SJS), not to be confused with toxic epidermal necrosis (TEN), as physiopathological pathways are throughly different. Mycoplasma pneumoniae is an intracellular germ, generally responsible for atypical respiratory infections. It may be associated with erythema multiforme, eventually recurrent, illustrated by the present case report.

First principles NMR calculations of phenylphosphinic acid C6H5HPO(OH): assignments, orientation of tensors by local field experiments and effect of molecular motion

The complete set of NMR parameters for (17)O enriched phenylphosphinic acid C(6)H(5)HP( *)O(*OH) is calculated from first principles by using the Gauge Including Projected Augmented Wave (GIPAW) approach [C.J. Pickard, F. Mauri, All-electron magnetic response with pseudopotentials: NMR chemical shifts, Phys. Rev. B 63 (2001) 245101/1-245101/13]. The analysis goes beyond the successful assignment of the spectra for all nuclei ((1)H, (13)C, (17)O, (31)P), as: (i) the (1)H CSA (chemical shift anisotropy) tensors (magnitude and orientation) have been interpreted in terms of H bonding and internuclear distances. (ii) CSA/dipolar local field correlation experiments have allowed the orientation of the direct P-H bond direction in the (31)P CSA tensor to be determined. Experimental and calculated data were compared. (iii) The overestimation of the calculated (31)P CSA has been explained by local molecular reorientation and confirmed by low temperature static (1)H-->(31)P CP experiments.

Global models from the Canadian lynx cycles as a direct evidence for chaos in real ecosystems

Real food chains are very rarely investigated since long data sequences are required. Typically, if we consider that an ecosystem evolves with a period corresponding to the time for maturation, possessing few dozen of cycles would require to count species over few centuries. One well known example of a long data set is the number of Canadian lynx furs caught by the Hudson Bay company between 1821 and 1935 as reported by Elton and Nicholson in 1942. In spite of the relative quality of the data set (10 undersampled cycles), two low-dimensional global models that settle to chaotic attractors were obtained. They are compared with an ad hoc 3D model which was proposed as a possible model for this data set. The two global models, which were estimated with no prior knowledge about the dynamics, can be considered as direct evidences of chaos in real ecosystems.

Application of the MAS-J-HMQC experiment to a new pair of nuclei {29Si,31P}: Si5O(PO4)6 and SiP2O7 polymorphs

We report the results of the two-dimensional MAS-J-HMQC experiment providing scalar correlations between 29Si and 31P nuclei in solid state NMR, and we give the first evaluation of the 2JSi-O-P coupling constants (approximately 15 Hz) for a crystalline silicophosphate phase Si5O(PO4)6. The experiment is applied to the characterization of complex mixtures of SiP2O7 phases, through editing of 31P spin pairs by the heteronuclear 2JP-O-Si interaction.

Modeling maps by using rational functions

Rational functions are not very useful for obtaining global differential models because they involve poles that may eject the trajectory to infinity. In contrast, it is here shown that they allow one to significantly improve the quality of models for maps. In such a case, the presence of poles does not involve any numerical difficulty when the models are iterated. The models then take advantage of the ability of rational functions to capture complicated structures that may be generated by maps. The method is applied to experimental data from copper electrodissolution.