Wound dressing with sustained anti-microbial capability

Amphiphilic poly(ether ester amide) (PEEA) multiblock copolymers were synthesized by polycondensation in the melt from hydrophilic poly(ethylene glycol) (PEG), 1,4-dihydroxybutane and short bisester-bisamide blocks. These amide blocks were prepared by reaction of 1,4-diaminobutane with dimethyl adipate in the melt. A range of multiblock copolymers were prepared, with PEG contents varying from 23-66 wt %. The intrinsic viscosity of the PEEA polymers varied from 0.58-0.78. Differential scanning calorimetry showed melting transitions for the PEG blocks and for the amide-ester blocks, suggesting a phase separated structure. Both the melting temperature and the crystallinity of the hard amide-ester segments decreased with increasing PEG content of the polymers. The equilibrium swelling ratio in phosphate buffered saline (PBS) increased with increasing amount of PEG in the polymers and varied from 1.7 to 3.7, whereas the polymer that contained 66 wt % PEG was soluble in PBS. During incubation of PEEA films in PBS, weight loss and a continuous decrease in the resulting inherent polymer viscosity was observed. The rate of degradation increased with increasing PEG content. The composition of the remaining matrices did not change during degradation. A preliminary investigation of the protein release characteristics of these PEEA copolymers showed that release of the model protein lysozyme was proportional to the square root of time. The release rate was found to increase with increasing degree of swelling of the polymers.     

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.     

Paramagnetic macrocyclic complexes as contrast agents for MR imaging: proton nuclear relaxation rate enhancement in aqueous solution and in rat tissues

Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA.     

Improved quantification of amyloid burden and associated biomarker cut-off points: results from the first amyloid Singaporean cohort with overlapping cerebrovascular disease

European Journal of Nuclear Medicine and Molecular Imaging - The analysis of the [11C]PiB-PET amyloid images of a unique Asian cohort of 186 participants featuring overlapping vascular diseases...     

维生素K3粉末降解动力学

在温度为50～90℃,相对湿度为50～93%范围内,维生素K₃的变色速率方程为—dR/dt=k_RR,降解速率方程为d(C_o—c)/dt=k_C(c_o—c)^1/2,光解速率方程为—dR/dt=k_P(R_o—R)^-1。k_R和_C与热力学温度T和相对湿度RH的关系通式为k=k′exp(—E_A/RT)exp(m′RH)。在实验温度和湿度范围内,变色和降解的表观活化能平均值分别为105.51和130.72 kJ/mol。     

An Audit of the Activities of the Pediatric Dermatology Nurse Specialist (PDNS)

Abstract:   In the current financial climate where resources in the National Health Service are becoming increasingly limited, it is essential that the role of the pediatric dermatology nurse specialist remains appreciated and supported. Our pediatric dermatology nurse specialist was first employed in September 2002 having had 6 years experience nursing children with a wide variety of dermatologic conditions prior to her employment. She achieved her pediatric community nursing degree in 2003 undertaking the nurse prescribing extended formulary course in 2006, her training history representative of many nurse specialists. We present the results of an audit highlighting how the employment of our pediatric dermatology nurse specialist has led to a decrease in hospital admissions as well as providing a significant positive impact on waiting lists.     

Feasibility and validity of ecological momentary assessment in adolescents with high-functioning autism and Asperger's disorder

Ecological Momentary Assessment (EMA) may increase accuracy of data compared with retrospective questionnaires by assessing behaviours as they occur, hence decreasing recall biases and increasing ecological validity. This study examined the feasibility and concurrent validity of an EMA tool for adolescents with High-Functioning Autism Spectrum Disorders (HFASD). Thirty-one adolescents with HFASD completed a mobile phone EMA application that assessed stressors and coping for two weeks. Parents and adolescents also completed retrospective measures of the adolescent's coping/stressors. Moderate compliance with the EMA tool was achieved and some concurrent validity was established with the retrospective measure of coping. Concordance was found between the types of stressors reported by parents and adolescents but not the quantity. The results suggest adolescents with HFASD are capable of reporting on their stressors and coping via EMA. EMA has the potential to be a valuable research tool in this population.