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Biomedical subjects

J W Hutchinson

Publications and source records attributed to J W Hutchinson.

12 recordsLinked to original sources
PubMed2006

Dynamics of fracture in drying suspensions.

We investigate the dynamics of fracture in drying films of colloidal silica. Water loss quenches the nanoparticle dispersions to form a liquid-saturated elastic network of particles that relieves drying-induced strain by cracking. These cracks display intriguing intermittent motion originating from the deformation of arrested crack tips and aging of the elastic network. The dynamics of a single crack exhibits a universal evolution, described by a balance of the driving elastic power with the sum of interfacial power and the viscous dissipation rate of flowing interstitial fluid.

Journal Article↗
PubMed2005

Onset of buckling in drying droplets of colloidal suspensions.

Minute concentrations of suspended particles can dramatically alter the behavior of a drying droplet. After a period of isotropic shrinkage, similar to droplets of a pure liquid, these droplets suddenly buckle like an elastic shell. While linear elasticity is able to describe the morphology of the buckled droplets, it fails to predict the onset of buckling. Instead, we find that buckling is coincident with a stress-induced fluid to solid transition in a shell of particles at a droplet's surface, occurring when attractive capillary forces overcome stabilizing electrostatic forces between particles.

Journal Article↗
PubMed2003

Flow and fracture in drying nanoparticle suspensions.

Drying aqueous suspensions of monodisperse silica nanoparticles can fracture in remarkable patterns. As the material solidifies, evenly spaced cracks invade from the drying surface, with individual cracks undergoing intermittent motion. We show that the growth of cracks is limited by the advancement of the compaction front, which is governed by a balance of evaporation and flow of fluid at the drying surface. Surprisingly, the macroscopic dynamics of drying show signatures of molecular-scale fluid effects.

Journal Article↗
PubMed2001

Finger sucking digital deformities.

We report our experience with severe digital deformities caused by prolonged finger sucking. Our analysis of nine patients demonstrated that the deformity was mainly located in the proximal and middle phalanges of the affected digit(s). We have reviewed the literature, enumerated the common patterns of "finger sucking" and explained the resulting deformities. Corrective osteotomy, preferably at the metacarpal base level, is required in severe deformities.

Adolescent↗
PubMed2001

Hip abductor strength following total hip arthroplasty: a prospective comparison of the posterior and lateral approach in 100 patients.

We studied the hip abductor strength and Trendelenburg test prospectively in 100 patients undergoing total hip replacement via a lateral or posterior approach. In 49 patients, we used the lateral approach to implant the Charnley total hip replacement, and in 51 patients, the posterior approach to implant the Exeter total hip. Isometric abductor strength was measured with the kinetic communicator device and the Trendelenburg test was recorded preoperatively and at 3 and 12 months postoperatively. Of the original 100 patients, 83 were available for study at 3 months and 73 at 12 months. Hip abductor strength and the Trendelenburg test improved postoperatively in both groups, but we found no difference in hip abductor strength recovery at 3 and 12 months between the lateral approach and the posterior approach. Similarly there was no difference in the Trendelenburg test between the two groups 3 and 12 months following hip replacement.

Adult↗
PubMed2001

When business is a confidence game.

When it comes to making business decisions, being overconfident about your choices can actually be more harmful than just guessing. Here's how managers can calibrate their confidence levels-and avoid being too sure in the wrong situations.

Administrative Personnel↗
PubMed1998

Dupuytren's disease and frozen shoulder induced by treatment with a matrix metalloproteinase inhibitor.

In a series of 12 patients with inoperable gastric carcinoma who had treatment with a synthetic matrix metalloproteinase inhibitor (Marimastat) for more than one month, six developed a frozen shoulder or a condition resembling Dupuytren's disease. This suggests that the matrix metalloproteinases, a family of naturally occurring proteinases, may be involved in the pathogenesis of these two conditions. Our observation opens avenues for further research which could lead to local or systemic therapeutic interventions for frozen shoulder and Dupuytren's disease.

Adenocarcinoma↗
PubMed1997

Heuristics and biases in the "eyeballing" of data: the effects of context on intuitive correlation assessment.

For a wide variety of real-world decisions, people must examine numerical tables and intuitively assess the correlations that exist among meaningful variables. The normative properties of correlation coefficients suggest that such decisions should be unaffected by perceptual factors (e.g., changes in row and column locations), semantic factors (e.g., the referents of the numbers), or certain transformations of the variables (e.g., adding a constant or multiplying by a constant). Four experiments demonstrated that judgments based on perceived correlations violate these normative properties. A general model of intuitive covariation assessment was proposed to explain the observed biases. Estimation of this model at the aggregate and individual levels suggested that no single heuristic is consistent with all of the results. Instead, the existence of several qualitatively different types of heuristics was supported. The distribution of individual-level decision rules across types of heuristics was systematically related to contextual factors.

Adult↗
PubMed1997

Diphyllobothriasis after eating raw salmon.

An 11-year-old boy in Hawaii passed mucus and a moving object in his stool. The object was identified as a segment of the fish tapeworm Diphyllobothrium species which is not indigenous to Hawaii. Diphyllobothrium ova were also found in the stool. The only raw fish he recalled eating in previous months were tuna sushi and lomi-lomi salmon which usually contains raw but previously frozen salmon. Of these two fish, only salmon which is not native to Hawaiian waters, has been incriminated as a significant source of diphyllobothrium fish tapeworm infection. Freezing kills this parasite, however, we speculate that the raw fish in the lomi-lomi salmon that our patient had eaten had not been pre-frozen or was not adequately pre-frozen. Eating raw salmon without certainty that it has been adequately pre-frozen carries the risk of diphyllobothriasis or fish tapeworm infection.

Animals↗
PubMed1995

Bone buttress operation for recurrent anterior shoulder dislocation in epilepsy.

Patients suffering from generalised convulsions may dislocate their shoulders either anteriorly or posteriorly. Those with anterior dislocation are likely to have recurrent episodes because of secondary bony damage to the anterior rim of the glenoid and head of the humerus. In such patients there is high rate of failure of the standard soft-tissue stabilisation procedures. We have therefore devised a bone buttress operation in which autograft or allograft is secured to the deficient anterior glenoid and shaped to form an extension of its articular surface. We report our experience in 14 patients with grandmal epilepsy and recurrent anterior dislocation of the shoulder. After the bone buttress operation there were no further dislocations and all patients were satisfied despite a small restriction in their range of movement. We believe this to be the operation of choice for patients with this difficult problem.

Activities of Daily Living↗