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L Maini

Publications and source records attributed to L Maini.

11 recordsLinked to original sources
PubMed2004

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.

Adolescent↗
PubMed2002

Painful knees.

Explore the source record for details and available documents.

Arthroplasty, Replacement, Knee↗
PubMed2001

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.

Journal Article↗
PubMed2000

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.

Journal Article↗
PubMed2000

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.

Journal Article↗
PubMed2000

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.

Journal Article↗
PubMed2000

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.

Adolescent↗
PubMed1999

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.

Adolescent↗