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811.
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A chemoenzymatic strategy has been exploited to make covalently linked alginate beads with high stability. This was achieved by grafting mannuronan (alginate with 100% mannuronic acid (M)) with methacrylate moieties and then performing two enzymatic steps converting M to guluronic acid (G) in alternating sequences (MG-blocks) and in G-blocks. In this way a methacrylate grafted alginate with better gel-forming ability was achieved. Covalent bindings were introduced into the beads by using a photoinitiating system that initiated polymerization of the methacrylate moieties. The covalent links were demonstrated by beads remaining intact after treatment with EDTA. The new chemoenzymatic photocrosslinked (CEPC) beads were compatible with cells with low post-encapsulation ability like C2C12 myoblasts and human pancreatic islets. The islets continued secreting insulin after encapsulation. On contrary, cells with a high post-encapsulation proliferative ability like 293-endo cells died within 2-week post-encapsulation. The exceptional stability and the cell compatibility of the new CEPC beads make them interesting as bioreactors for delivering therapeutic proteins in future applications.  相似文献   
815.
Infants predict other people's action goals   总被引:1,自引:0,他引:1  
Do infants come to understand other people's actions through a mirror neuron system that maps an observed action onto motor representations of that action? We demonstrate that a specialized system for action perception guides proactive goal-directed eye movements in 12-month-old but not in 6-month-old infants, providing direct support for this view. The activation of this system requires observing an interaction between the hand of the agent and an object.  相似文献   
816.
The main purpose of this eye tracking study was to map the correlates of gaze performance in a brief test of spontaneous gaze and point-gesture following in young children with autistic disorder (AD), Pervasive developmental disorder-not otherwise specified (PDD-NOS), or typical development (TD). Gaze measures included the children's spontaneous tendency to look at the correct (attended) toy, and the latency of their correct responses. In addition to group differences (AD vs. TD), we found that in AD, accuracy of performance was specifically related to adaptive communication skills. The study also indicated that the latency of correct gaze shifts is related to verbal intelligence. These results have direct implications for our understanding of (responsive) joint attention impairments in AD.  相似文献   
817.

Background  

The epidemiology of suicidality shows considerable variation across sites. However, one of the strongest predictors of suicide is a suicidal attempt. Knowledge of the epidemiology of suicidal ideas and attempts in the general population as well as in the health care system is of importance for designing preventive strategies. In this study, we will explore the role of the psychiatric hospital in suicide prevention by investigating treated incidence of suicidal ideation and attempt, and further, discern whether sociodemographic, clinical and service utilization factors differ between these two groups at admission.  相似文献   
818.
Infection with hepatitis B causes between 500,000 and 1.2 million deaths per year worldwide, and is the leading cause of liver cancer. Over 12 years ago, WHO recommended that universal childhood hepatitis B vaccination be implemented globally. Despite this, Denmark, Finland, Iceland, Ireland, the Netherlands, Norway, Sweden, and the UK have yet to implement such a policy and instead currently adopt an "at-risk" strategy. Although all eight countries are classed as having low endemicity, factors such as increased travel and integration of immigrant communities are increasing the number of at-risk individuals in these countries. Considering the difficulty in identifying all at-risk individuals, and the lack of effectiveness of at-risk vaccination on reducing the overall incidence of hepatitis B, we recommend that these countries reassess their hepatitis B prevention strategies. Universal vaccination against hepatitis B is the only way to eliminate the major public-health impact of this disease.  相似文献   
819.
OBJECTIVES: Patients on antiepileptic drugs (AEDs) may have low serum concentrations of thyroxine, with or without a compensatory increment in thyroid-stimulating hormone (TSH). Furthermore, patients on AEDs often have hyperhomocysteinemia and low concentrations of vitamins B(6), B(2) and folate. Previously, an inverse relationship between thyroxine and homocysteine concentrations has been observed. In animals, deficiency of vitamin B(6) has been found to impair the hypophyseal release of TRH. We have studied the effect of B-vitamin supplements on thyroid function in patients on AEDs. DESIGN AND METHODS: Thirty-two patients on AEDs were identified with hyperhomocysteinemia and low folate, B(6) and B(2). They were supplemented with pyridoxine, riboflavin and folic acid for 30 days. RESULTS: At baseline, the patients had low serum concentrations of free thyroxin and slightly elevated TSH. On day 30 of the B-vitamin supplements, homocysteine had decreased, however, the thyroid parameters remained unchanged. CONCLUSIONS: Hyperhomocysteinemic patients on AEDs have indications of hypothyroidism, however, supplementation with B-vitamins does not improve their thyroid function.  相似文献   
820.
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