A synergic approach of X-ray powder diffraction and Raman spectroscopy for crystal structure determination of 2,3-thienoimide capped oligothiophenes.

This work presents a Raman based approach for the rapid identification of the molecular conformation in a series of new 2,3-thienoimide capped quaterthiophenes, whose crystal structures were determined by synchrotron radiation X-ray powder diffraction. These systems display two conformational polymorphs, known as forms A and B, as a result of the anti-anti-anti and syn-anti-syn arrangements of the quaterthiophene cores. In a micro-Raman and computational study, the spectroscopic differences between the conformers were detected and proved to be suitable markers for polymorph identification. Thus, the synergic employment of diffraction and Raman spectroscopy techniques yields a full and reliable characterization of 2,3-thienoimide capped quaterthiophene compounds in their solid state.

Three-dimensional printing and patient-specific pre-contoured plate: future of acetabulum fracture fixation?

PURPOSE: Due to the complexity of acetabulum, achieving anatomical contouring intra-operatively is difficult for surgeon. A 3D (dimensional) real model can facilitate us both in contouring the plate pre-operatively and in better pre-operative planning. Patient-specific pre-contoured plate in acetabular fracture has been studied by few researchers but randomized case-control study was lacking. Hence, we conducted a case-control study to evaluate the accuracy of patient-specific pre-contoured plate. MATERIALS AND METHODS: Prospective randomized case control study was conducted. 21 patients were included. 10 patients were distributed in "case" group and remaining 11 in "control" group. INCLUSION CRITERIA: Displaced acetabulum fractures with displacement of ≥3 mm in adults who reported within 3 weeks of injury. Exclusion criteria were: Open fractures, associated Morel-Lavallée lesion and patients with >3 weeks old fracture. In case group, patient-specific real 3D model of fractured acetabulum was generated using rapid prototyping technology and plates were contoured pre-operatively. Control group was treated using intra-operative contoured plates. Both the groups were compared using parameters: Blood loss, Surgery time, post-operative reduction on X-ray, post-surgical residual displacement and reduction achieved as evaluated by CT scan. RESULTS: Reduced blood loss (100 ml less in case group) and surgical time (12 min less in case group) and better post-operative reduction were observed in case than control. In control group, 4 patients even had step of 2-3 mm, which was not seen in case group. All the pre-contoured plates fitted well to the pelvis intra-operatively. Reduction achieved as evaluated by CT was more in "case" group with statistically significant outcomes (p < 0.05). CONCLUSION: Patient-specific pre-contoured plate made using 3D model is a better implant than intra-operatively contoured plate. Real-time 3D pelvis model is an accurate technique for pre-operative planning in acetabular fractures.

Unusual presentation of chondroblastoma mimicking Trevor's disease.

Chondroblastoma is a benign bone tumor, represents 1%-2% of all primary bone tumors, typically seen in patients 10-25-year-old and more common in males. It occurs most frequently in the distal femur, proximal tibia, and proximal humerus. Soft tissue extension is extremely rare. Adjacent joints may develop effusions, but the tumor mass protruding into the joint has never been seen in case of chondroblastoma. We report a rare case of intra-articular chondroblastoma arising from proximal tibia in a 16-year-old boy and growing into the knee joint mimicking an intra-articular osteochondroma.

White luminescence achieved by a multiple thermochromic emission in a hybrid organic-inorganic compound based on 3-picolylamine and copper(i) iodide.

Three copper(i) complexes have been obtained by the reaction of CuI with 3-picolylamine in acetonitrile solution and characterized by X-ray powder diffraction, both from synchrotron and laboratory radiation. Photophysical investigations in the solid state revealed highly efficient thermally-activated delayed fluorescence (TADF) with photoluminescence quantum yields (PLQYs) up to 18%. Notably, the complex [Cu2I2(3pica)]∞ displays a strong luminescence thermochromism due to the presence of both 1,3(X + M)LCT excited states and a lower-lying cluster-centered (3CC) one, leading to multiple emission at room temperature; as a result, a white luminescence is achieved with a PLQY of 4.5%.

Dual luminescence in solid CuI(piperazine): hypothesis of an emissive 1-D delocalized excited state.

Solid [CuI(piperazine)0.5]∞, characterized by a structure with an infinite double chain of CuI, presents an unexpected dual luminescence. The short copper-copper distances allow the existence of both cluster-centered and 1-D delocalized electronic transitions, as emerged from theoretical calculations. Beyond the more common cluster-centered emission a higher energy band, which differs in lifetime and in temperature dependence, is observed.

Stopping light in two dimensional quasicrystalline waveguides.

The introduction of defects in photonic lattices generally allows to control the localization and the propagation of light. While point defects are conventionally used in order to obtain localized photonic states, linear defects are introduced for waveguiding EM waves. In this work we demonstrate the possibility of obtaining localized states also in a waveguiding configuration, by using quasicrystalline lattices. This result opens a new range of possibilities in designing optical circuits, in which the localization-propagation switch is easly obtainable by mechanical or opto-electric methods.

Delayed internal fixation of fractures of the neck of the femur in young adults. A prospective, randomised study comparing closed and open reduction.

We have compared the results and complications after closed and open reduction with ternal fixation in young adults with displaced intracapsular fractures (Garden grades III and IV) of the neck of the femur. We also studied the risk factors which influenced nonunion and the development of avascular necrosis (AVN). A total of 102 patients aged between 15 and 50 years was randomised to receive either closed or open reduction. Both groups were compared for age, gender, time to surgery and posterior comminution as well as for union and complications. Using univariate and multivariate analysis the factors influencing nonunion and AVN were assessed. Of the 102 patients, 92 were available for review. There was no significant difference between the groups in terms of union (p = 0.93) and AVN at two years (p = 0.85). Posterior comminution, poor reduction and improper placement of the screws were the major factors contributing to nonunion. The overall incidence of AVN was 16.3% (15 of 92 patients) and it was not influenced by these factors. A delay of more than 48 hours before surgery did not influence the rate of union or the development of AVN when compared with operation within 48 hours of injury.

Reversible trapping of acid and base vapours into an amphoteric crystalline material.

Exposure of the solid zwitterion [CoIII(eta 5-C5H4CO2H)(eta 5-C5H4CO2)] to hydrated vapours of volatile acids (HCl, CF3CO2H, HBF4) or bases (NH3, NMe3, NH2Me) quantitatively produces the corresponding salts; the heterogeneous reactions are fully reversible, as the acid or base molecules can be removed by thermal treatment, regenerating the starting material.

The Ilizarov method in infected nonunion of fractures.

Thirty patients with infected non-union of long bones were treated with radical resection of the necrotic bone and bone transport or compression/distraction osteosynthesis. Non-union, infection, deformity, bone gap and shortening were all addressed simultaneously using the Ilizarov principles. There were 15 cases with bone loss ranging from 4 to 12 cm (median bone gap of 7 cm), 10 cases of stiff non-union (six of which had an associated deformity) and five cases of mobile non-union. The median time in the Ilizarov frame was 150 days. Median follow up time after frame removal was 23.5 months. Bone grafting at the docking site was only required in three cases (10%). There were three cases of refracture (10%) and three cases of recurrence of infection (10%). The bone result was excellent in 21 patients (70%), good in three (10%), fair in none (0%) and poor in six (20%). The functional results were excellent in eight patients (26.7%), good in 12 (40.0%), fair in three (10%) and poor in seven (23.3%). It is difficult to precisely define the indications for preservation and reconstruction of severe injuries. The surgical team has to take into account the length, disability, complications and cost of treatment. Patients must be aware of the limitations of functional results and the possible difficulty of return to work despite the reconstructive attempt.

Anions derived from squaric acid form interionic pi-stack and layered, hydrogen-bonded superstructures with organometallic sandwich cations: the magnetic behaviour of crystalline

Depending on the stoichiometric ratio, squaric acid (3,4-dihydroxy-3-cyclobutene-1,2-dione, H2SQA) reacts with [(eta6-C6H6)2Cr] in THF to form the crystalline material [(eta6-C6H6)2Cr][HSQA] (1) and in water to yield [[(eta6-C6H6)2Cr]2][SQA] x 6H2O (3); it also reacts with [(eta5-C5H5)2Co][OH] in water to form [[(eta5-C5H5)2Co]2][SQA] x 6H2O (4). Compound 1 is almost isostructural with the previously reported salt [(eta5-C5H5)2Co][HSQA] (2); its structure is based on pi-pi stacks between the benzene ligands and the hydrogen squarate anionic chains (pi-pi distance 3.375 A). Compounds 3 and 4 are isomorphous and have a structure in which layers of organometallic cations intercalate with layers of water molecules hydrogen bonded to squarate dianions. All crystals contain charge-assisted C-Hdelta+...Odelta- hydrogen bonds between the organometallic and the organic components, while negative O-H(-)...O(-) and O-H...O(2-) interactions are present in the pairs 1/3 and 2/4, respectively. In constrast to most organic salts of [(eta6-C6H6)2Cr]+ and [(eta5-C5H5)2Co]+ which are yellow, crystals of compounds 1-4 are orange. Reflectance spectra measured on the crystalline material 1 show the presence of an intense tail that can be assigned to a charge-transfer transition through the [(eta6-C6H6)2Cr]+/[HSQA]- pi-stacking interactions, while the pi stacking in 2 causes only a broadening of the band. The magnetic behaviour of 1 and 3 has been investigated by SQUID magnetometry. Both compounds are characterised by a weak antiferromagnetic interaction between the S=1/2 Cr centres of the [(eta6-C6H6)2Cr]+ cations, which is significantly stronger in 1 due to the pi-stacking with the HSQA- anions.

Tunable supramolecular synthons and versatile, water-soluble building blocks for crystal engineering:.

It is shown that the water-soluble dicarboxylic cationic acid [(eta5-C5H4COOH)2Co(III)]+ (1) is an extremely versatile building block for the construction of organometallic crystalline edifices. Removal of one proton from 1 leads to formation of the neutral zwitterion [(eta5-C5H4COOH)(eta5-C5H4COO)Co(III)] (2), while further deprotonation leads to formation of the dicarboxylate monoanion [(eta5-C5H4COO)2Co(III)]- (3). Compounds 1. 2 and 3 possess different hydrogen-bonding capacity and participate in a variety of hydrogen-bonding networks. The cationic form 1 has been characterised as its [PF6]- and Cl- salts 1-[PF6] and 1-Cl.H2O, as well as in its co-crystal with urea, 1-Cl.3(NH2)2CO, and with the zwitterionic form 2, [(eta5-CH4COOH)(eta5-C5H4COO)Co(III)][(eta5-C5H4COOH)2Co(III)]+[PF6]-, 2.1-[PF6]. The neutral zwitterion 2 behaves as a supramolecular crown ether: it encapsulates the alkali cations K+, Rb+ and Cs+ as well as the ammonium cation NH4+ in cages sustained by O-H...O and C-H...O hydrogen bonds to form co-crystalline salts of the type 2(2)-M[PF6] (M = K, Rb, Cs) and 2(2)-[NH4][PF6]. The deprotonated acid 3 has been characterised as its Cs+ salt, Cs+-3.3H2O.

Interanionic (-)O-H...O(-) interactions: a solid-state and computational study of the ring and chain motifs.

The (-)O-H...O(-) interaction formed by the anions HCO3-, HCO4, HC4O4 and HC5O5- (HA-), obtained upon monodeprotonation of the corresponding carbonic, oxalic, squaric and croconic acids (H2A), has been investigated theoretically and experimentally. The ring (RING) and chain (CHAIN) hydrogen bond motifs established between these anions have been analysed in terms of geometry and energy and their occurrence in crystalline salts investigated by searching the Cambridge Structural Database (CSD) and the Inorganic Chemistry Structural Database (ICSD). It has been shown that hydrogen carbonates form RINGs, with the notable exception of NaHCO3, while only CHAINs are known for hydrogen oxalates. Hydrogen squarates and hydrogen croconates can form both RINGs and CHAINs. The structures of Rb- and Cs- hydrogen croconates, which present the two alternative motifs, have been discussed together with that of the hydrated salt NaHC5O5.H2O. The relationship between RING and CHAIN has been examined in the light of ab initio calculations. A rigorous quantum chemical study of the nature of the interanionic (-)O-H...O(-) interaction in both vacuum and condensed phase has shown that the interaction energy is dominated by the electrostatic component which becomes attractive at short O...O distances (less than 2.5 A) if the net ionic charge on the anion is delocalised away from the -OH group. It has been demonstrated that the RING motif is slightly metastable with respect to dissociation in the gas phase, but becomes stable in the crystal owing to the influence of the Madelung field. However, the CHAIN motif is unstable both in the gas phase and in the crystal. It is argued that interanionic (-)O-H...O(-) interactions ought to be regarded as stabilising bonding interactions rather than proper intermolecular hydrogen bonds because the RING and CHAIN aggregates are not energetically stable on an absolute scale of bonding energy (i.e., in the absence of counterions). The presence of very short non-hydrogen-bridged O...O contacts resulting from charge compression of polyatomic anions bridged by alkali cations is also discussed.

Spinal epidural abscess - a report of six cases.

Six cases of spinal epidural abscess are presented. All patients were young with no predisposing conditions. All were treated with laminectomy and intravenous antibiotics. The patients with no neurological deficit recovered completely, while patients with pre-existing neurological deficit had a poorer outcome. Emphasis is given to early detection and surgical management to prevent irreversible damage to the spinal cord.