This is a comparative quantitative morphological study of the regeneration of paraosseous muscle tissue in the process of healing bone fractures using the preparation based on etidronate without ...lanthanoids and in conjunction with them. The fragments of the muscle tissue from the fracture region were investigated. These fragments were obtained in 45 outbred white rats at day 7, day 14, and day 30 after osteotomy in the zone of the middle third of the femoral shaft. Histological sections were prepared and investigated morphometrically. The areas of leukocyte-necrotic masses were determined, as well as those of granulation tissue, normally and necrotically changed muscle tissue, loose fibrous unformed and dense fibrous connective tissue, adipose tissue, blood vessels, and perivascular and interstitial edema. In addition, a quantitative analysis of the inflammatory cellular infiltration was performed by counting neutrophils, lymphocytes, macrophages, eosinophils, plasma, and mast cells. The data obtained were processed statistically. For a comparative study, three groups were identified: (1) control—a fracture without treatment; (2) after paraosseous infusion of etidronate with calcium ions without lanthanoids; (3) after paraosseous infusion of etidronate with calcium ions and lanthanoids. The best result of paraosseous muscle tissue restoration after injury was obtained when using etidronate in conjunction with calcium ions without lanthanoids. When lanthanoids were added, the reparative processes in soft tissues proceeded more slowly. However, in all respect, they were superior to the control group (fracture without treatment), especially at the final stage of regeneration (day 30). Thus, the areas of the leukocyte-necrotic masses, necrotically changed muscle tissue, and perivascular and interstitial edema were smaller significantly. At the same time, the level of the inflammatory cell infiltration of paraosseous tissues was lower substantially. Moreover, there were no such morphological changes, as calcinosis foci and epithelioid cell granulomas with the presence of giant multinucleated cells such as foreign bodies. In contrast to the control, there was no incomplete regeneration or substitution in the form of the parts of muscle replacement with dense fibrous connective tissue and adipose tissue. The area of unhanged muscle tissue, the most important criterion of regeneration, when using etidronate in conjunction with calcium ions and lanthanoids, was 10% more than that in the control group. Despite the fact that the use of etidronate without lanthanoids provides the best results in the repair of soft tissues, in the healing of fractures, the compounds containing them should be used. This is dictated by the fact that the restoration of bone is the priority of reparative regeneration after injury, and the use of lanthanoids in conjunction with etidronate and calcium ions for bone tissue healing is the most effective.
The comparative qualitative morphological study of bone fracture healing using etidronate-based preparation free of lanthanoids and in conjugation with them. The fragments of bone tissue from the ...facture zone were studied. They were obtained in 45 mongrel white rats on day 7, day 14, and day 30 after osteotomy in the zone of femoral shaft middle third. The investigation was performed by a morphological method in the three groups: (1) control, a fracture without treatment; (2) after paraosseous infusion of etidronate with lanthanoid and calcium ions; (3) after paraosseous infusion of etidronate with calcium ions without lanthanoids. The areas of leukocyte-necrotic masses with blood clots, those of granulation, connective and cartilaginous tissue, coarse-fibrous trabecular bone and lamellar bone, as well as those of necrotic bone parts were determined in the histological sections of the fracture zone with a morphometric grid. The data obtained were processed statistically. The best results of bone tissue healing for fractures were obtained when paraosseous infusing etidronate in combination with lanthanoids, and the effect of this was revealed just in the early periods after trauma. In this case, the intensity of injury-induced inflammatory reaction lowered and the volume of leukocyte-necrotic masses and traumatic edema decreased. The process of reparative regeneration accelerated as well with formation of granulation tissue and after that connective tissue and coarse-fibrous trabecular bone. Besides, indirect osteogenesis with bone formation through cartilaginous tissue was less common. As a result, there was uncomplicated fracture healing in most observations with the presented significant amount of formed compact and spongy lamellar bone. The combination of the etidronate-based preparation with lanthanoids is the most optimal, and its use is effective at all stages of bone fracture healing.
Abstract Propranolol has been used successfully in a limited number of children with infantile hemangiomas (IHs). This study describes the efficacy and adverse effects of propranolol in IH. ...Seventy-one infants with IHs were treated with oral propranolol, administered at a dose of 2 mg/kg/day, for at least 12 weeks. A photograph-based severity scoring assessment was performed by five observers to evaluate efficacy, utilizing a score of 10 as the original IHs before treatment and 0 as completely normal skin. The mean of the five independent measurements was used in the analysis. Propranolol was a rapid and effective treatment for IHs at 4 weeks ( P < 0.001), at 8 weeks ( P < 0.001 compared with the value at 4 weeks), at 12 weeks ( P < 0.05 compared with the value at 8 weeks), and thereafter up to 32 weeks ( P < 0.01 compared with the value at 16 weeks). The response of IHs to propranolol was similar regardless of gender, age at the onset of treatment, type of involvement (local and extended), facial segments affected, special locations (eyelid, nasal tip, and parotid regions), ulceration, and depth of IHs. In the series of patients in this study, oral propranolol at a dosage of 2 mg/kg/day was a well-tolerated and effective treatment for IHs.
The convergence of a column generation algorithm can be improved in practice by using stabilization techniques. Smoothing and proximal methods based on penalizing the deviation from the incumbent ...dual solution have become standards of the domain. Interpreting column generation as cutting plane strategies in the dual problem, we analyze the mechanisms on which stabilization relies. In particular, the link is established between smoothing and in-out separation strategies to derive generic convergence properties. For penalty function methods as well as for smoothing, we describe proposals for parameter self-adjusting schemes. Such schemes make initial parameter tuning less of an issue as corrections are made dynamically. Such adjustments also allow us to adapt the parameters to the phase of the algorithm. We provide extensive test reports that validate our self-adjusting parameter scheme and highlight their performances. Our results also show that using smoothing in combination with a penalty function yields a cumulative effect on convergence speed-ups.
Mixed ionic-electronic conductors are of great interest for development of oxygen separation membranes and air electrodes for intermediate temperature solid oxide fuel and electrolysis cells. This ...work presents the results of studying the structure, transport properties and oxygen mobility in Nd2−xCaxNiO4 oxides (x = 0–0.5), synthesized via a solution-assisted solid state reaction method, in correlation with the over-stoichiometric oxygen content. High oxygen mobility was demonstrated in the low-doped materials (DO ~ 10−10–10−8 cm2/s at 700 °C) which corresponded to the ionic (oxygen) conductivity values ~ 10−4–10−2 S/cm, comparable to those for widely used solid electrolytes and state-of-the-art cathode materials. The polarization resistance of the Nd2−xCaxNiO4+δ electrodes in contact with Ce0.8Sm0.2O1.9 electrolyte was shown to have non-linear dependency on Ca content, which may be caused by the influence of two opposite tendencies for decreasing over-stoichiometric oxygen and oxygen diffusivity and increasing the total conductivity with Ca doping. High electrical and electrochemical characteristics along with oxygen mobility mean the materials developed display high potential for electrochemical and catalytic applications.
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•Structure and electrical properties of Nd2−xCaxNiO4+δ (x = 0–0.5) were studied.•Doping with Ca is revealed to increase the electrical conductivity.•Oxygen diffusion and surface exchange coefficients were evaluated from TPIE data.•Ca doping effect on oxygen kinetics is less pronounced then in La, Pr nickelates.•Optimal Ca content for the SOFC cathode application was found to be 20 mol%.
Abstract
Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI) observations reveal a class of solar flares with substantial energy and momentum impacts in the photosphere, ...concurrent with white-light emission and helioseismic responses, known as sunquakes. Previous radiative hydrodynamic modeling has demonstrated the challenges of explaining sunquakes in the framework of the standard flare model of “electron beam” heating. One of the possibilities to explain the sunquakes and other signatures of the photospheric impact is to consider additional heating mechanisms involved in solar flares, for example via flare-accelerated protons. In this work, we analyze a set of single-loop Fokker–Planck and radiative hydrodynamics RADYN+FP simulations where the atmosphere is heated by nonthermal power-law-distributed proton beams which can penetrate deeper than the electron beams into the low atmospheric layers. Using the output of the RADYN models, we calculate synthetic Fe
i
6173 Å line Stokes profiles and from those the line-of-sight observables of the SDO/HMI instrument, as well as the 3D helioseismic response, and compare them with the corresponding observational characteristics. These initial results show that the models with proton beam heating can produce the enhancement of the HMI continuum observable and explain qualitatively the generation of sunquakes. The continuum observable enhancement is evident in all models but is more prominent in ones with
E
c
≥ 500 keV. In contrast, the models with
E
c
≤ 100 keV provide a stronger sunquake-like helioseismic impact according to the 3D acoustic modeling, suggesting that low-energy (deka- and hecto-keV) protons have an important role in the generation of sunquakes.
Progress in hydrogen energy and promising directions for its modern development are closely related to design of fuel cells, including solid oxide fuel cells, and solid state membranes for hydrogen, ...oxygen and synthesis gas production. A necessary condition for fabrication of economically competitive devices in this area is the use of cheap electrode materials combining high electrochemical activity and long-term stability. Ln2NiO4+δ oxides with the Ruddlesden–Popper layered structure possessing a high mixed ion-electron conductivity and moderate values of the coefficients of thermal expansion are promising materials for development of oxygen-conducting membranes and cathodes of intermediate-temperature solid oxide fuel cells.
In this paper structural characteristics, electrical conductivity, oxygen mobility and electrochemical properties of Ln2-xCaxNiO4+δ (Ln = La, Pr, Nd; x = 0; 0.3) samples were studied to determine factors, which have the most significant effect on the electrochemical activity of electrodes and their stability. It was found that doping with calcium lead to stabilization of the structure and increased the electrical conductivity of materials. However, addition of calcium decreased the electrochemical activity of electrodes in varying degrees depending on the nature of lanthanide. There is no direct interrelation of such a decrease of activity with either the electrical properties or the interstitial oxygen content. We have revealed correlation of the polarization resistance of electrodes with characteristics of oxygen transfer in the electrode material (self-diffusion coefficient, surface exchange constant). Using the C18O2 SSITKA method, the total oxygen mobility in the doped materials was shown to fall with doping due to a decrease in the content of highly mobile interstitial oxygen and hampering of the cooperative oxygen transport mechanism. In the case of La1.7Ca0.3NiO4+δ, this leads to the appearance of a slow diffusion channel and a substantial decrease in the total diffusion coefficient value which results in a sharp increase in the polarization resistance of the electrodes. This phenomenon is not observed in materials with praseodymium and neodymium. The electrodes based on Pr1.7Ca0.3NiO4+δ and Nd1.7Ca0.3NiO4+δ, developed in this work, have an acceptable level of the electrochemical activity along with a high electrical conductivity and increased stability in comparison with undoped compositions and can be recommended for use as cathodes for intermediate temperature fuel cells.
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