Yttrium immobilization through biomineralization with phosphate by the resistant strain Mesorhizobium qingshengii J19.

AIMS: Yttrium (Y) holds significant industrial and economic importance, being listed as a critical element on the European list of critical elements, thus emphasizing the high priority for its recovery. Bacterial strategies play a crucial role in the biorecovery of metals, offering a promising and environmentally friendly approach. Therefore, gaining a comprehensive understanding of the underlying mechanisms behind bacterial resistance, as well as the processes of bioaccumulation and biotransformation, is of paramount importance. METHODS AND RESULTS: A total of 207 Alphaproteobacteria strains from the University of Coimbra Bacteria Culture Collection were tested for Y-resistance. Among these, strain Mesorhizobium qingshengii J19 exhibited high resistance (up to 4 mM Y) and remarkable Y accumulation capacity, particularly in the cell membrane. Electron microscopy revealed Y-phosphate interactions, while X-ray diffraction identified Y(PO3)3·9H2O biocrystals produced by J19 cells. CONCLUSION: This study elucidates Y immobilization through biomineralization within phosphate biocrystals using M. qingshengii J19 cells.

Amorphous Solid Forms of Ranolazine and Tryptophan and Their Relaxation to Metastable Polymorphs.

Different methods were explored for the amorphization of ranolazine, a sparingly soluble anti-anginal drug, such as mechanochemistry, quench-cooling, and solvent evaporation from solutions. Amorphous phases, with Tg values lower than room temperature, were obtained by cryo-milling and quench-cooling. New forms of ranolazine, named II and III, were identified from the relaxation of the ranolazine amorphous phase produced by cryo-milling, which takes place within several hours after grinding. At room temperature, these metastable polymorphs relax to the lower energy polymorph I, whose crystal structure was solved in this work for the first time. A binary co-amorphous mixture of ranolazine and tryptophan was produced, with three important advantages: higher glass transition temperature, increased kinetic stability preventing relaxation of the amorphous to crystalline phases for at least two months, and improved aqueous solubility. Concomitantly, the thermal behavior of amorphous tryptophan obtained by cryo-milling was studied by DSC. Depending on experimental conditions, it was possible to observe relaxation directly to the lower energy form or by an intermediate metastable crystalline phase and the serendipitous production of the neutral form of this amino acid in the pure solid phase.

Introduction to Pharmaceutical Co-amorphous Systems Using a Green Co-milling Technique.

The concept of co-amorphous systems is introduced in an integrated laboratory experiment, designed for advanced chemistry students, using solvent-free, environmentally friendly mechanochemistry. The dual-drug naproxen-cimetidine co-amorphous system (NPX-CIM) is investigated as an example of the emergent field of medicinal mechanochemistry. Students are trained in solid-state characterization techniques including X-ray powder diffraction, Fourier-transform infrared spectroscopy, and thermal analysis by differential scanning calorimetry. This lab experiment also provides an opportunity to discuss the relevance of different solid forms of pharmaceutics, emphasizing particular properties of disordered materials. This experiment can easily fit the curriculum of any Chemistry or Pharmacy master level degree in courses dealing with instrumental analysis, solid state chemistry, or green chemistry, for classes of 6 to 18 students, in a 5-h lab session. Suggestions to adapt it to the use of a single characterization technique are provided.

On the Performance of Hybrid Functionals for Non-linear Optical Properties and Electronic Excitations in Chiral Molecular Crystals: The Case of Butterfly-Shaped Dicinnamalacetone.

Purely organic chiral molecular assemblies in the solid state hold great potential for non-linear optical applications. Herein, a newly synthesised molecular system is reported, namely, dicinnamalacetone, an otherwise planar molecule that crystallises in a disordered non-centrosymmetric form with four different conformations having an overall predominance of a particular helicity. A combined experimental and theoretical approach, including single-crystal X-ray diffraction, Kurtz-Perry and ab initio methods, is employed to characterise the system and benchmark the performance of hybrid functionals for the prediction of non-linear optical properties and electronic excitations. Comparison of experiment and theory points to a particular set of hybrid functionals that provides an optimal description of this molecular system.

l-Histidinium thiocyanurate: Experimental and theoretical studies of a new nonlinear optical material.

A new organic compound, l-histidinium thiocyanurate thiocyanuric acid dihydrate, has been synthesized and characterized by single crystal X-ray diffraction, infrared spectroscopy and nonlinear optical measurements. The efficiency of the second-harmonic generation was evaluated with the Kurtz and Perry powder method at a fundamental wavelength of 1064nm. By using the experimental structure, the molecular first hyperpolarizability tensor was determined with Hartree-Fock and density functional theory methods. The second-order susceptibility tensor of the crystal was evaluated using the oriented gas model with the Lorenz-Lorentz and the Wortmann-Bishop local-field corrections.

Structural and nonlinear optical studies of a salt with an octupolar chromophore: Guanidinium cyclopropanecarboxylate.

A new organic compound, guanidinium cyclopropanecarboxylate, has been synthesized and characterized by single crystal X-ray diffraction, infrared spectroscopy and nonlinear optical measurements. The infrared spectrum was calculated with density functional theory (DFT). The second-order NLO response was evaluated with the Kurtz and Perry powder method. From the molecular structure, the molecular hyperpolarizability tensor was determined with Hartree-Fock and DFT methods. The second-order susceptibility tensor of the crystal was evaluated by the summation of the effective hyperpolarizability tensors calculated for the asymmetric unit surrounded by ESP-derived charges.

Acetylcholinesterase and Cytotoxic Activity of Chemical Constituents of Clutia lanceolata Leaves and its Molecular Docking Study.

Phytochemical investigations of the ethanolic extract of leaves of Clutia lanceolata (Family: Euphorbiaceae) resulted in the isolation of four compounds viz. 3,4-dihydroxy-2-methylbenzoic acid (1), 2,2'-dihydroxy-1,1'-binaphthyl (2), 1,3,8-trihydroxy-6-methylanthracene-9,10-dione (3) and 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (4). Although all the isolated compounds were known but this was the first report from this plant source. Their structures were established on the basis of chemical and physical evidences viz. elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectral analysis. Structure of compound 2 and 4 was further authenticated by single-crystal X-ray analysis and density functional theory calculations. The isolated compounds (1-4) were screened for AChE enzyme inhibition assay in which compound 3 and 4 were found to be more potent AChE inhibitor. Molecular docking study of potent AChE inhibitor was performed to find the probable binding mode of the compounds into the active site of receptor. Moreover, the isolated compounds were also screened for in vivo cytotoxicity by brine shrimp lethality assay.

Epithelioid sarcoma of the spine: case report and literature review.

Epithelioid sarcomas are rare mesenchymal neoplasms mainly arising in the limbs of young adults. We report the case of a 24-year-old male presenting low back pain radiating to both lower limbs, constipation and urinary retention. The MRI scan showed an intraspinal lesion extending from L4 to S2. Surgery resulted in gross total removal of the extradural lesion and partial removal of the intradural component. The immunohistological study of the lesion was consistent with an epithelioid sarcoma. The patient was submitted to radiotherapy and chemotherapy, but a local recurrence of the lesion and dissemination along the neuraxis were observed 3 months after surgery. Despite treatment, the patient died 4 months after the surgical procedure due to multiorgan failure. Despite there being isolated reports of epithelioid sarcomas appearing in the spine, this is, to our knowledge, the first case with intradural extension.

Structure and NIR-luminescence of ytterbium(III) beta-diketonate complexes with 5-nitro-1,10-phenanthroline ancillary ligand: assessment of chain length and fluorination impact.

Seven new tris(ß-diketonear-nate)ytterbium(III) complexes with the general formula [Yb(ß-diketonate)3(5NO2phen)] (where the ß-diketone is either 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione, 1,1,1-trifluoro-2,4-pentanedione, 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione, 1,1,1,5,5,6,6,7,7,7-decafluoro-2,4-heptanedione, 2,4-hexanedione or 2,6-dimethyl-3,5-heptanedione, and 5NO2phen = 5-nitro-1,10-phenanthroline) were synthesized and characterized by elemental analysis, attenuated total reflectance Fourier transform infrared spectroscopy and photoluminescence spectroscopy. Single crystal X-ray structures have been determined for three fluorinated complexes and ground state geometries of the other four complexes have been predicted using the Sparkle/PM6 model. These experimental structures and those designed by semi-empirical models reveal octacoordination around the Yb(3+) ion. Photoluminescence studies and lifetime measurements show that the increase in the fluorinated ß-diketonate chain length is associated with a decrease in Yb(3+) luminescence intensity of the (2)F5/2→(2)F7/2 transition at around 980 nm and the (2)F5/2 excited state lifetime, while the ligand lifetime value remains almost unaffected. Finally, fluorination of the ligands is only advised when the complexes are to be used for co-doping with isostructural Er(3+) complexes for optical amplifiers, since it leads to a slight decrease in luminescence intensity for the same ß-diketonate chain length.

Learning curve and complications of minimally invasive transforaminal lumbar interbody fusion.

OBJECT: Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has the potential advantage of minimizing soft-tissue damage and reducing recovery time compared to open procedures. A steep learning curve has been described for the technique. The aim of the present study was to define the learning curve that describes the progress of a single surgeon performing the MI-TLIF. METHODS: One hundred fifty consecutive patients with degenerative lumbar disease who underwent 1- or 2-level MI-TLIF were included in the study. Operative time, corrected operative time per level, and complications were analyzed. The learning curve was assessed using a negative exponential curve-fit regression analysis. RESULTS: One hundred ten patients underwent 1-level and 18 patients underwent 2-level MI-TLIF; the remaining 22 underwent a single-level procedure plus an ancillary procedure (decompression at adjacent level, vertebral augmentation through fenestrated pedicle screws, interspinous device at adjacent level). Negative exponential curves appropriately described the relationship between operative time and experience for 1-level surgery and after correction of operative time per level (R(2) = 0.65 and 0.57). The median operative time was 140 minutes (interquartile range 120-173 minutes), and a 50% learning milestone was achieved at Case 12; a 90% learning milestone was achieved at Case 39. No patient required transfusion in the perioperative period. The overall complication rate was 12.67% and the most frequent complication was a dural tear (5.32%). Before the 50% and 90% learning milestones, the complication rates were 33% and 20.51%, respectively. CONCLUSIONS: The MI-TLIF is a reliable and effective option for lumbar arthrodesis. According to the present study, 90% of the learning curve can be achieved at around the 40th case.

Amplification of the linear and nonlinear optical response of a chiral molecular crystal.

We have observed large second-order nonlinear optical and vibrational circular dichroism (VCD) responses in a charge-transfer-type L-Histidinium salt. Using X-ray Diffraction, VCD spectroscopy, and time-dependent density functional theory to characterize the compound, we employ a two-level model to explain and quantify the strongly enhanced optical signals. We find that both linear and nonlinear optical responses are greatly enhanced by a single low-lying charge-transfer state.

Monoclinic polymorph of 2-(pyrimidin-2-ylsulfan-yl)acetic acid.

The title compound, C(6)H(6)N(2)O(2)S, is a new polymorphic form of 2-(pyrimidin-2-ylsulfan-yl)acetic acid. Unlike the previous orthorhombic polymorph [Pan & Chen (2009 ▶) Acta Cryst. E65, o652], the mol-ecules are not planar: the aromatic ring makes an angle of 80.67 (17)° with the carboxyl plane. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds into chains along [02].

Crystal structure and experimental and theoretical studies of the second-order nonlinear optical properties of salts of triphenylguanidine with carboxylic acids.

N,N',N''-triphenylguanidinium carboxylate salts have been prepared by acid-base reactions of triphenylguanidine with formic, benzoic, and m-methoxybenzoic acids, and their single-crystal X-ray structure analysis has been performed. The salts were found to crystallize into noncentrosymmetric structures with an orthorhombic space group P2(1)2(1)2(1) for the formate and m-methoxybenzoate salts and a monoclinic space group Cc for the benzoate salt. The anions and cations are linked by intermolecular hydrogen bonds with the same motifs in the three salts. By using the molecular structures, the molecular first hyperpolarizabilities of several clusters were determined by semiempirical methods, and the components of the second-order susceptibility tensor, d, of triphenylguanidine and those of the reported crystals were evaluated using the oriented gas model with two different local-field corrections. The efficiency of the second-harmonic generation of triphenylguanidine and that of the reported triphenylguanidinium salts were measured using the Kurtz and Perry powder method.