Silk fibroin increases the elasticity of alginate-gelatin hydrogels and regulates cardiac cell contractile function in cardiac bioinks.

Silk fibroin (SF) is a natural protein extracted fromBombyx morisilkworm thread. From its common use in the textile industry, it emerged as a biomaterial with promising biochemical and mechanical properties for applications in the field of tissue engineering and regenerative medicine. In this study, we evaluate for the first time the effects of SF on cardiac bioink formulations containing cardiac spheroids (CSs). First, we evaluate if the SF addition plays a role in the structural and elastic properties of hydrogels containing alginate (Alg) and gelatin (Gel). Then, we test the printability and durability of bioprinted SF-containing hydrogels. Finally, we evaluate whether the addition of SF controls cell viability and function of CSs in Alg-Gel hydrogels. Our findings show that the addition of 1% (w/v) SF to Alg-Gel hydrogels makes them more elastic without affecting cell viability. However, fractional shortening (FS%) of CSs in SF-Alg-Gel hydrogels increases without affecting their contraction frequency, suggesting an improvement in contractile function in the 3D cultures. Altogether, our findings support a promising pathway to bioengineer bioinks containing SF for cardiac applications, with the ability to control mechanical and cellular features in cardiac bioinks.

A review of ultraviolet treatment for psoriasis at Waikato Hospital.

Details of 79 courses of UVB and 40 courses of PUVA for patients with chronic plaque psoriasis at Waikato Hospital were prospectively collected when a new Phototherapy Unit opened. Efficacy was assessed by clearance rates (73% for UVB, 87.5% for PUVA). There was significant improvement in Psoriasis Disability Index, which was derived from a questionnaire assessing functional disability and completed by the patients before and after treatment. It took a median number of 24 treatments for psoriasis in the patients receiving UVB to clear, and for the PUVA patients the median was 19 treatments. The efficacy could not be correlated with skin type. Fifty per cent of UVB patients and 25% of PUVA patients received symptomatic burns, all localized and minor in nature. LIfetime PUVA dose was calculated, 90% of patients having received less than 400 J/cm2.

Primary school children's perceptions of the effects of sun on skin.

To assess whether young children understand the dangers and results of sun exposure, a novel Draw and Write technique was used to survey a group of 5-8 year old primary school children. One hundred and ninety-four children were invited to draw and write comments to six scenarios involving sun exposure. Of the children surveyed, 84% gave a negative sentiment to sunburn, with only 6% displaying positive sentiments towards sunbathing. Sixty-five per cent of children suggested the use of sun blocks, 69% the use of protective clothing, 45% the wearing of hats and 43% the use of shade as a mechanism for protecting the skin from sun damage. Only 2% of children made any reference to skin cancer. The primary school children surveyed had a good level of awareness of the dangers of sunburn and the need to take appropriate actions to avoid sun damage.

Relative effectiveness of three repair strategies on the visual-identification of misperceived words.

Experimental videotapes were used to assess the effectiveness of three repair strategies: (1) repetitions, (2) synonyms, and (3) paraphrases. Three groups of normal-hearing adults viewed one of three videotapes. The same 50 test-words were used on each videotape. Each test-item consisted of three stimuli: a test-word, a stimulus that incorporated the repair strategy under investigation, and a repetition of the initial test-word. Each videotape displayed one of the three repair strategies under investigation. The subjects were required to identify test-words presented in a visual-only mode. The results indicated that the performance of the subjects who were provided with synonyms or paraphrases was significantly better than the performance of the subjects who were shown repetitions. Also, subjects who were shown paraphrases performed significantly better than those who were shown synonyms. These findings indicate that repair strategies that incorporate the use of substitute stimuli such as synonyms and paraphrases may be more effective than the simple repetition of the misperceived stimulus.