Search

The design of concrete structures is based on calculation rules, which often do not take into account the very early age behaviour of the material. However, during this period, structural concrete is subjected to strains due to the hydration process of cement. If these strains are restrained by concrete itself or surrounding boundaries, stresses start to build up that can lead to the formation of cracks. Among the parameters involved in the stress build up, the stiffness evolution is of major importance. This paper reports the use of eight different techniques aimed at stiffness evolution assessment, applied on the same concrete mix, in a round robin experimental test within three laboratories. The observations are compared after having expressed the results at the same equivalent age. Both the loading stress rate and amplitude are observed to have an effect of limited importance on the determination of the quasi-static elastic modulus, which might be explained by very short term creep. Ultrasonic measurements provide values of E-modulus that are higher than the values provided by the quasi-static tests at the time of the concrete setting. Similar mechanisms associated to very short term creep could explain the difference between the quasi-static and high-frequency elastic modulus. [ABSTRACT FROM AUTHOR]

During hominin evolution, an increase in the femoral bicondylar angle was the initial change that led to selection for protuberance of the lateral trochlear lip and the elliptical profile of the lateral condyle. No correlation is found during ontogeny between the degree of femoral obliquity and of the prominence of the lateral trochlear lip. Might there be a relationship with the elliptical profile of the lateral condyle? On intact femoral diaphyses of juvenile humans and great apes, we compared the anteroposterior length of the lateral and medial sides of the distal metaphysis. The two diaphyseal pillars remain equal during postnatal growth in great apes, while the growth of the lateral pillar far exceeds that of the medial pillar in humans. Increase in bicondylar angle is correlated with disproportionate anteroposterior lengthening of the lateral pillar. The increased anteroposterior length of the lateral side of the metaphysis would contribute to increasing the radius of the curvature of the lateral condyle, but not to the projection of the lateral trochlear lip. The similar neonatal and adult femoro-patellar joint shape in humans prompted an assessment of the similarity during growth of the entire neonatal and adult epiphyses. We showed that the entire epiphysis undergoes drastic changes in proportions during postnatal growth. Finally, we emphasize the need to distinguish the cartilaginous phenotype and the ossified phenotype of the distal femoral epiphysis (and of any epiphysis) during postnatal growth. This crucial distinction applies to most postcranial bones, for they almost all develop following the process of endochondral ossification. [ABSTRACT FROM AUTHOR]

Ciguatera is the most frequently observed form of tropical fish poisoning. It appears as a syndrome associating general signs, gastrointestinal, cardiac and neurological problems. Peripheral and central nervous system signs may be observed. We report a case of a 60-year-old man who developed Ciguatera poisoning with diarrhea, facial paresthesia, myalgia, cramps and weakness. Physical examination revealed a motor distal deficit of the four limbs, myokymia and ataxia. EMG testing was in favor of an axonal neuropathy. Neurologic symptoms persisted for two months. This case illustrates a new pathophysiological mechanism of neuropathy: 'axonal channelopathy'. Abnormalities of peripheral nerve sodium and potassium channels result in clinical and electrophysiological manifestations unrelated to axonal degeneration or demyelinization. The ciguatoxin mainly acts on sodium channels. Prolonged sodium channel activation results in repetitive axon firing. Recently ciguatoxin was demonstrated to have a novel action, blocking the sodium channel leading to slowed nerve conduction and decreased motor and sensory action potential amplitudes. [ABSTRACT FROM AUTHOR]

Reviews the CD-ROM Autopsy Room by Simon Cross, Roger Start and Dennis Cotton. Feature of the autopsy process; CD-ROM designed for medical undergraduates.

Aims: Sweet's syndrome is an acute febrile neutrophilic dermatosis first described in 1964 by Robert Douglas Sweet. The pathophysiological mechanism is not fully established; however, several cases of Sweet's syndrome have been reported following drug administration., Methods: To investigate the existence of pharmacovigilance signals between drugs and the occurrence of Sweet's syndrome, we performed a case/non-case study on reports of 'acute febrile neutrophilic dermatosis' registered in the French pharmacovigilance database. Reporting odds ratio (ROR) with its 95% confidence interval were calculated., Results: Amongthe 994 789 reports recorded in the database, 136 were Sweet's syndrome, of which 50.7% were men and the median age was 59 years (range 15-91). A total of 224 drugs were mentioned as suspects: 21.0% were antibacterials, 19.2% were antineoplastics and 12.1% were immunosuppressants. Median time to onset from drug initiation to the development of Sweet's syndrome was 15 days (range 1-1095). The highest RORs were observed with bortezomib (74.04 [40.8-134.2]), azacitidine (72.14 [29.4-176.9]), perfilgrastim (67.05 [21.2-211.6]), azathioprine (55.46 [34.8-88.4]) and bendamustine (35.84 [11.4-112.8])., Conclusions: Pharmacovigilance signals have been observed between the occurrence of Sweet's syndrome and colony-stimulating factors, immunosuppressants, antineoplastics and antibiotics. Clinicians should be aware of the potential associations with these drugs and should be encouraged to report any case of drug-induced Sweet's syndrome., (© 2023 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

This review is based on the findings of the Southampton Clinical Skills Project, which was a needs assessment and feasibility study to consider the development of a multiprofessional Clinical Skills Resource at Southampton. The project spanned a period of 18 months and used a range of methods of data collection, including visits to 12 clinical skills facilities in the UK. Most existing clinical skills centres have developed in response to changing healthcare policy, curricular initiatives and increasing emphasis on the quality of assessments and competencies. There is also increasing recognition that clinicians are no longer able to teach effectively all skills to students in the traditional ways, and that clinical skills training and assessment, particularly for undergraduates, is an area of deficiency. The potential scope of clinical skills centres is broad and encompasses not only clinical and communication skills but medical informatics, computer assisted learning, multiprofessional learning and assessment. Skills centres can also promote self directed and lifelong learning methods. The planning of skills centres involves a variety of stakeholders and users, including undergraduates, postgraduates, acute and community Trusts, Postgraduate Deans and medical schools. A successful skills centre needs to be flexible in its design, integral to the curriculum and relevant to educational and training requirements. This requires planning, organization and resources. Different organizational models can be used, depending on local factors. The management of skills centres involves consideration of issues such as security, safety, supervision of learners and staff development, informed by a network of experts and everyday users. The development of skills centres should include ongoing educational evaluation of outcomes and educational research. The use of a clinical skills centre has potential benefits for staff and students, including the provision of a safe environment in which to learn and practise skills before using them in the real clinical setting. This can reduce anxiety in students and protect patients from novice practice. Clinical skills centres provide a setting for structured learning with feedback as well as assessment of competence. The limitations of a skills centre are that it can only provide simulated experiences which are an adjunct to, but can never replace real clinical experience.