Changes in the Strength Properties and Phase Transition of Gypsum Modified with Microspheres,Aerogel and HEMC Polymer

The paper presents an assessment of the impact of using additives on the strength of a binding material, i.e., building gypsum, and also the phase transformation that takes place in it. Microspheres, aerogel and polymer (HEMC) additives were added to a building gypsum slurry with a water to gypsum ratio of 0.75. In order to investigate their influence on bending strength, compressive strength, and the effect of high temperatures, differential scanning calorimetry (DSC), as well as tests of the multicomponent binder, were carried out in accordance with the applicable PN-EN 13279-2:2005 standard. The obtained test results allowed to determine that the used additives influenced the strength parameters of the obtained composites. It was shown that the applied additives decreased the compressive and bending strength of the modified gypsum. Despite these properties, the obtained gypsum materials are environmentally friendly because they reuse wastes, such as microspheres. Out of all the applied additives, the use of microspheres in an amount of 10% caused a decrease in the bending strength by only 10%, and an increase in the compressive strength by 4%.     

Casein/Apricot Filler in the Production of Flame-Retardant Polyurethane Composites

Polyurethane (PUR) composites reinforced with 1, 2, and 5 wt.% of apricot filler modified with casein were synthesized in the following study. The impact of 1, 2, and 5 wt.% of casein/apricot filler on the cellular structure and physico-mechanical performances of reinforced PUR composites were determined. It was found that the incorporation of 1 and 2 wt.% of casein/apricot filler resulted in the production of PUR composites with improved selected physical, thermal, and mechanical properties, while the addition of 5 wt.% of casein/apricot filler led to some deterioration of their physico-mechanical performance. The best results were obtained for PUR composites reinforced with 2 wt.% of casein/apricot filler. Those composites were characterized by a uniform structure and a high content of closed cells. Compared with the reference foam, the incorporation of 2 wt.% of casein/apricot filler resulted in improvement in compressive strength, flexural strength, impact strength, and dynamic mechanical properties—such as glass transition temperature and storage modulus. Most importantly, PUR composites showed better fire resistance and thermal stability due to the good thermal performance of casein. The main aim of this article is to determine the influence of the natural combination of the apricot filler and casein on the mechanical properties and flammability of the obtained composites.     

The prevalence of falls and their relation to visual and hearing impairments among a nation-wide cohort of older Poles

Falls are a geriatric syndrome which affects the physical and psychological well-being of the aged. So far, in Poland there have not been any population-based data on the prevalence of falls among the elderly.     

Stem cells in the treatment of diabetes

Clinical islet transplantation trials based on cadaveric allogenic islets have demonstrated that it is indeed possible to restore near‐physiological insulin secretion capacity in a type 1 diabetic patient through transplantation of insulin‐producing cells. In order to develop this form of therapy to become available for the vast majority of patients with diabetes, new sources of transplantable insulin‐producing cells need to be identified. Stem cells provide the best potential to achieve this goal. Controversial results have been presented concerning the existence and nature of pancreatic islet stem or precursor cells. An increasing body of evidence suggests that the pancreatic and hepatic cell types (hepatocytes, islet, acinar and ductal cells) have remarkable plasticity and can de‐ and trans‐differentiate into each other under appropriate conditions. Elucidation of the molecular mechanisms regulating these processes could lead to clinically applicable ways of either inducing pancreatic islet regeneration in situ or to expanding the insulin‐producing cells in vitro for transplantation. The emergence of human embryonic stem cells has led to an active area of research aiming to achieve targeted differentiation of these cells into a safely transplantable beta‐like cell. After initial excitement, it appears that much basic research is still required before this goal could be achieved.     

Characteristics of pilomatrixoma in children: A review of 137 patients

Objective

To describe our institutional experience with pilomatrixoma in the pediatric population, specifically examining its clinical presentation, associated conditions, surgical treatment and future implications.

Methods

This is a retrospective review of a single tertiary care center. Subjects included 137 patients with diagnosis of pilomatrixoma between the years of 2000 and 2013 up to the age of 19. Patient gender, age at excision, number of tumors, tumor size, tumor location, preoperative diagnosis, recurrence, patient race and zip code, along with associated medical conditions were assessed.

Results

There were a total of 174 tumors in 137 patients. The median age at excision was 7.1 years old, with the youngest patient at 6 months and the oldest at 19 years. Head and neck tumors predominated with 70% (n = 122) of all pilomatrixomas, followed by the upper extremity with 22% (38). Other locations included the hair-bearing back, chest and lower extremities. A male to female ration of 1:1.2 was observed. Tumor diameter size ranged from 0.2 to 5.2 cm with an average diameter of 1.4 cm. There were no cases of recurrence. Associated diagnoses included Turner syndrome and Sticker syndrome.

Conclusions

Pilomatrixoma, previously thought to be a rare lesion, is one of the most common causes of superficial head and neck masses in children. This study demonstrates clinical presentations that should help guide differential diagnoses. We demonstrate associations that are consistent with the proposed pathophysiology of pilomatrixoma. Surgical excision is curative.     

Can the antiplatelet effects of cangrelor be reliably studied in mice under in vivo and in vitro conditions using flow cytometry?

BackgroundThe effects of blood platelet inhibitors are often not quite equivalent under in vivo and in vitro conditions. Amongst various models of human pathology using laboratory animals, mice offer several benefits that make them convenient tools for studying the putative therapeutic value of various compounds. However, despite its advantages, the mouse model has methodological limitations concerning the small amount of blood available and technical difficulties with its collection. Among the variety of available methods used to study blood platelet activation and/or reactivity, flow cytometry seems an attractive technique that largely minimizes the constraints of using small rodents and enables outcomes of laboratory research to be transferred successfully to clinical practice.In this study we aimed at a critical evaluation of the optimal discriminative flow cytometric protocol, useful for reliable studies of the effect of cangrelor, a P2Y₁₂ receptor antagonist, on mouse platelets under in vitro and in vivo conditions.MethodsBlood samples were drawn from two-month-old female BALB/c mice. Protocols differing in methods of anesthesia, blood withdrawal, anticoagulation, gating antibodies, blood preparation and fixation were tested to optimize the one best suited to discrimination between resting and activated platelets. The antiplatelet capabilities of cangrelor were tested in vitro (140 μM in whole blood) and in vivo (7.8 mg/kg b.w. administered once, directly into the bloodstream through the vena cava of the anesthetized animal, 15 min prior to blood withdrawal). Expressions of P-selectin, activated α_IIbβ₃ complex and GPIbα were monitored using two-color flow cytometry.Results“Washed blood” anticoagulated with low molecular weight heparin demonstrated the best discrimination between circulating (resting) platelets and upon their in vitro response to thrombin, collagen or ADPin freshly-stained unfixed cell suspensions. Cangrelor inhibited the expression of the active form of the integrin α_IIbβ₃ to approximately the same extent under in vitro and in vivo conditions (84.5 ± 7.7% vs. 75.4 ± 19.5% for the in vitro and in vivo approaches, respectively, n.s.).ConclusionsThe agreement between the in vivo and in vitro approaches with respect to cangrelor-inhibited hallmarks of blood platelet activation and reactivity supports our proposal that flow cytometry is useful and reliable for determining the effects of antiplatelet agents on the activation of circulating platelets in the mouse model, as well as the in vitro response of platelets to agonists.