Prenatal diagnosis and management of Apert syndrome in a low-middle income country: Case report.

INTRODUCTION AND IMPORTANCE: Apert syndrome is a rare autosomal dominant disorder characterized by craniosynostosis, midface hypoplasia, and syndactyly. Prenatal diagnosis of this condition can be challenging. This case report highlights the importance of recognizing characteristic ultrasound findings for timely diagnosis and genetic counselling. CASE PRESENTATION: A 37-year-old, gravida 1, para 0 woman underwent a routine third-trimester ultrasound at 31 weeks gestation. The examination revealed significant hydramnios, bilateral hand syndactyly, foot abnormalities, and an unusual head shape with a prominent forehead, flat occiput, hypertelorism, and low-set ears. These findings raised suspicion for Apert syndrome. Subsequent molecular analysis confirmed a mutation in the FGFR2 gene, confirming the diagnosis. Three-dimensional (3D) ultrasound imaging was utilized to provide the parents with a clearer understanding of the foetal anomalies, aiding in their decision-making process. Given the high risk of impaired intellectual development and the complexity of its management, the pregnancy was terminated at 33 weeks' gestation. CLINICAL DISCUSSION: This case emphasizes the role of comprehensive prenatal ultrasound in identifying potential foetal anomalies, even in the absence of prior risk factors. Characteristic sonographic findings, such as craniosynostosis, syndactyly, and hydramnios, should raise suspicion for the diagnosis, even in the absence of family history. Molecular confirmation through FGFR2 gene testing is essential for definitive diagnosis and informed genetic counselling. CONCLUSION: While Apert syndrome is rare, recognizing its characteristic sonographic features can facilitate timely diagnosis. The use of 3D ultrasound imaging can be invaluable in enhancing parental understanding and facilitating informed decision-making.

Transitioning to Insulin Analogs in Tunisian Children with Type 1 Diabetes: Efficacy and Safety.

INTRODUCTION: there is a lack of research evaluating the impact of therapeutic switching from human insulin to analogues, particularly in paediatric populations from low- and middle-income countries. AIM: The study aimed to retrospectively assess the effectiveness and safety of transitioning from human insulin to insulin analogs in Tunisian children with diabetes. METHODS: This retrospective descriptive study included children with type 1 diabetes who changed their insulin therapy protocol after at least one year of treatment with human insulin. Clinical, therapeutic, and glycaemic homeostasis parameters were assessed following the transition from human insulin (NPH + rapid-acting insulin) to the Basal-Bolus insulin analog- protocol. RESULTS: The study included 60 patients. Following the switch, all patients showed a significant reduction in mean fasting blood glucose levels (11.11 mmol/l vs. 8.62 mmol/l; p=0.024). Glycated haemoglobin A1C levels decreased notably in children who adhered to their diet (from 9.93% to 8.38%; p=0.06) and/or engaged in regular physical activity (from 10.40% to 8.61%; p=0.043). The average number of hypoglycemic events per year decreased from 4.03 events/year to 2.36 events/year (p=0.006), along with a decrease in the rate of patients hospitalized for acid-ketotic decompensation (from 27% to 10%; p=0.001). Financial constraints led to 82% of patients reusing microfine needles ≥2 times per day, and 12% were compelled to revert to the initial insulin therapy protocol due to a lack of access to self-financed microfine needles or discontinued social coverage. CONCLUSIONS: Although insulin analogues offer clear benefits, their use poses challenges as a therapeutic choice for children with diabetes in low- to middle-income countries. These challenges hinder the achievement of optimal glycemic control goals.

A systematic DFT study of structure and electronic properties of titanium dioxide.

DFT functionals are of paramount importance for an accurate electronic and structural description of transition metal systems. In this work, a systematic analysis using some well-known and commonly used DFT functionals is performed. A comparison of the structural and energetic parameters calculated with the available experimental data is made in order to find the adequate functional for an accurate description of the TiO2 bulk and surface of both anatase and rutile structures. In the absence of experimental data on the surface energy, the theoretical predictions obtained using the high-accuracy HSE06 functional were used as a reference to compare against the surface energy values calculated with the other DFT functionals. A clear improvement in the electronic description of both anatase and rutile was observed by introducing the Hubbard U correction term to PBE, PW91, and OptPBE functionals. The OptPBE-U4 functional was found to offer a good compromise between accurately describing the structural and electronic properties of titania.

Pediatric Psoriasis Associated with Van Wyk Grumbach Syndrome: A case report.

INTRODUCTION: Psoriasis is a common chronic inflammatory condition, often beginning in childhood in approximately one-third of cases. It can be associated with various other autoimmune diseases such as rheumatoid arthritis, celiac disease, and thyroid disorders. However, its co-occurrence with Van Wyk Grumbach syndrome has not been described in the pediatric population. This syndrome, resulting from untreated hypothyroidism, is characterized by early puberty and ovarian cysts. OBSERVATION: A 15-year-old adolescent with a diagnosis of psoriasis since the age of 9 presented with chronic constipation and headaches. She exhibited early puberty (menarche at 9 years) and academic regression. Clinical examination revealed growth retardation and arterial hypertension. Hormonal analyses revealed primary hypothyroidism : Free Thyroxine (FT4)=7pmol/mL(9- 20 pmol/l), Thyroid Stimulating Hormone (TSH)=200 mIU/mL( 0,4 - 5 mUI/ml.). The ultrasound and scintigraphic appearance were suggestive of thyroiditis. Additionally, she experienced menstrual irregularities and pelvic pain. Radiological exploration revealed a left ovarian cyst. The diagnosis of Van Wyk Grumbach syndrome was established due to early puberty, hypothyroidism, and polycystic ovary. Treatment with l-thyroxine led to stabilization of blood pressure and hormonal levels. Her height remained below the target adult height. CONCLUSION: Assessment of thyroid function appears necessary in pediatric patients with psoriasis. Early hormonal replacement therapy for hypothyroidism may alleviate the symptoms of Van Wyk Grumbach syndrome and mitigate its impact on stature.

Band-Gap Tuning in All-Inorganic CsPbxSn1-xBr3 Perovskites.

We investigate all-inorganic perovskite CsPbxSn1-xBr3 thin films to determine the variations in the band gap and electronic structure associated with the Pb/Sn ratio. We observe that the band gap can be tuned between 1.86 eV (x = 0) and 2.37 eV (x = 1). Intriguingly, this change is nonlinear in x, with a bowing parameter of 0.9 eV; furthermore, a slight band gap narrowing is found for low Pb content (minimum x ∼ 0.3). The wide tunability of the band gap makes CsPbxSn1-xBr3 a promising material, e.g., for a wide-gap subcell in tandem applications or for color-tunable light-emitting diodes. Employing photoelectron spectroscopy, we show that the valence band varies with the Pb/Sn ratio, while the conduction band is barely affected.

Tuning the Solid Electrolyte Interphase for Selective Li- and Na-Ion Storage in Hard Carbon.

Solid-electrolyte interphase (SEI) films with controllable properties are highly desirable for improving battery performance. In this paper, a combined experimental and theoretical approach is used to study SEI films formed on hard carbon in Li- and Na-ion batteries. It is shown that a stable SEI layer can be designed by precycling an electrode in a desired Li- or Na-based electrolyte, and that ionic transport can be kinetically controlled. Selective Li- and Na-based SEI membranes are produced using Li- or Na-based electrolytes, respectively. The Na-based SEI allows easy transport of Li ions, while the Li-based SEI shuts off Na-ion transport. Na-ion storage can be manipulated by tuning the SEI layer with film-forming electrolyte additives, or by preforming an SEI layer on the electrode surface. The Na specific capacity can be controlled to < 25 mAh g-1 ; ≈ 1/10 of the normal capacity (250 mAh g-1 ). Unusual selective/preferential transport of Li ions is demonstrated by preforming an SEI layer on the electrode surface and corroborated with a mixed electrolyte. This work may provide new guidance for preparing good ion-selective conductors using electrochemical approaches.

Solar Cell Materials by Design: Hybrid Pyroxene Corner-Sharing VO4 Tetrahedral Chains.

Hybrid organic-inorganic frameworks provide numerous combinations of materials with a wide range of structural and electronic properties, which enable their use in various applications. In recent years, some of these hybrid materials-especially lead-based halide perovskites-have been successfully used for the development of highly efficient solar cells. The large variety of possible hybrid materials has inspired the search for other organic-inorganic frameworks that may exhibit enhanced performance over conventional lead halide perovskites. In this study, a new class of low-dimensional hybrid oxides for photovoltaic applications was developed by using electronic structure calculations in combination with analysis from existing materials databases, with a focus on vanadium oxide pyroxenes (tetrahedron-based frameworks), mainly due to their high stability and nontoxicity. Pyroxenes were screened with different cations [A] and detailed computational studies of their structural, electronic, optical and transport properties were performed. Low-dimensional hybrid vanadate pyroxenes [A]VO3 (with molecular cations [A] and corner-sharing VO4 tetrahedral chains) were found to satisfy all physical requirements needed to develop an efficient solar cell (a band gap of 1.0-1.7 eV, strong light absorption and good electron-transport properties).

Hydrogen Bonding and Stability of Hybrid Organic-Inorganic Perovskites.

In the past few years, the efficiency of solar cells based on hybrid organic-inorganic perovskites has exceeded the level needed for commercialization. However, existing perovskites solar cells (PSCs) suffer from several intrinsic instabilities, which prevent them from reaching industrial maturity, and stabilizing PSCs has become a critically important problem. Here we propose to stabilize PSCs chemically by strengthening the interactions between the organic cation and inorganic anion of the perovskite framework. In particular, we show that replacing the methylammonium cation with alternative protonated cations allows an increase in the stability of the perovskite by forming strong hydrogen bonds with the halide anions. This interaction also provides opportunities for tuning the electronic states near the bandgap. These mechanisms should have a universal character in different hybrid organic-inorganic framework materials that are widely used.

Electronic structure and chemical bonding in the OTi-N2 complexes: a systematic ab initio and DFT study.

Two OTi-N2 complexes, experimentally observed in the TiO + N2 reaction, have been theoretically studied using several density functionals as well as ab initio approaches and various basis sets. The benchmark results calculated with coupled-cluster singles, doubles, and perturbative triples CCSD(T) and sufficiently large correlation-consistent basis set were used to assess the performance of other theoretical models, especially four density functional families, pure functional, hybrid, double-hybrid, and long-range corrected ones. It has been shown that, out of twenty-three density functionals used in this work, only three functionals, namely TPSS0, LC-TPSS, and B2PLYP, are able to reproduce the CC-reference data quantitatively. Particularly, the B2PLYP double-hybrid (with or without addition of empirical dispersion) is the most promising functional, providing the closest results to the reference ones. The nature of bonding within products has been investigated using two topological techniques and a localized orbital approach.

Covalent grafting of organic-inorganic polyoxometalates hybrids onto mesoporous SBA-15: a key step for new anchored homogeneous catalysts.

Covalent grafting of heteropolyanions hybrids B,α-[As(III)W9O33{P(O)(CH2CH2CO2H)}2](5-) on 3-aminopropyl functionalized SBA-15 has been achieved through the formation of peptide bonds. The covalent link has been confirmed by using IR and (13)C CP MAS NMR spectroscopies. Electrostatic interactions between carboxylate and protonated amines have been discarded on the basis of the retention of POMs after repeated washings of the resulting material by ionic liquid (bmimCl). This is the first example of anchored monovacant polyoxometalates (POM) in which nucleophilic oxygen atoms are still available after incorporation into mesoporous supports. Further characterization of the textural properties of grafted materials has shown that they still retain an important mesoporosity, which is compatible with their potential use in heterogeneous catalysis. Such systems are thus interesting candidates for the preparation of anchored homogeneous catalysts in which the POMs would play the role of polydentate inorganic ligands for the active centers.

Vibrational spectra and structures of Ti-N2O and OTi-N2: a combined IR matrix isolation and theoretical study.

The reaction of atomic titanium with nitrous oxide has been reinvestigated using matrix isolation in solid neon coupled to infrared spectroscopy and by quantum chemical methods. Our technique of sublimation of Ti atoms from a filament heated at about 1500 °C allowed the formation of three species: one Ti-N(2)O pair of van der Waals (vdW) type characterized by small red shift with respect to N(2)O monomer, and two isomers of OTi-N(2) pair where N(2) is in interaction with the OTi moiety either with end-on or side-on structure. Interconversion between these structures has been performed with several wavelengths. In the visible and near-ultraviolet the conversion vdW → OTi-N(2) (end-on) is observed with characteristic times strongly varying according to the wavelength. In the near-infrared the conversion OTi-N(2) (end-on) → OTi-N(2) (side-on) occurs, the vdW species remaining unchanged. These selectivities allow 8, 6, and 4 vibrational transitions to be assigned for vdW, (3)[OTi(η(1)-NN)] (end-on), and (1)[OTi(η(2)-NN)] (side-on), respectively. Electronic and geometrical structures are also investigated with double-hybrid functionals. It has been shown that the side-on geometry corresponds to the ground state of (1)[OTi(η(2)-NN)] in the singlet electronic state. The theoretical vibrational analysis supports well the experimental attributions.

Vibrational spectrum and structure of CoO6: a model compound for molecular oxygen reversible binding on cobalt oxides and salts; a combined IR matrix isolation and theoretical study.

The formation and structure of a novel species, a disuperoxo-cobalt dioxide complex (CoO(6)), has been investigated using matrix isolation in solid neon and argon, coupled to infrared spectroscopy and by quantum chemical methods. It is found that CoO(6) can be formed by successive complexation of cobalt dioxide by molecular oxygen without activation energy by diffusion of ground state O(2) molecules at 9K in the dark. The IR data on one combination and seven fundamentals, isotopic effects, and quantum chemical calculations are both consistent with an asymmetrical structure with two slightly nonequivalent oxygen ligands complexing a cobalt dioxide subunit. Evidence for other, metastable states is also presented, but the data are not complete. The electronic structure and formation pathway of this unique, formally +VI oxidation state, complex has been investigated using several functionals of current DFT within the broken-symmetry unrestricted formalism. It has been shown that the M06L pure local functional well reproduce the experimental observations. The ground electronic state is predicted to be an open shell (2)A'' doublet with the quartet states above by more than 9 kcal/mol and the sextet lying even higher in energy. The ground state has a strong and complex multireference character that hinders the use of more precise multireference approaches and requires caution in the methodology to be used. The geometrical, energetic, and vibrational properties have been computed.