Reinforcing aluminum alloys with high strength fibers

A study is made of the possibility of reinforcing aluminum and aluminum based alloys with fibers made of high strength steel wire. The method of introducing the fibers is described in detail. Additional strengthening by reinforcement of the high alloy system Al - An - Mg was investigated

Synthesis, acid‒base properties, and complexing properties of N,N-bis[butoxy(hydroxy)phosphinoylmethyl]glycine

© 2017, Pleiades Publishing, Ltd. N,N-Bis(dibutoxyphosphinoylmethyl)glycine was synthesized by the Kabachnik‒Fields reaction in the three-component system glycine hydrochloride–formaldehyde–dibutyl hydrogen phosphite. Saponification of the product gave N,N-bis[butoxy(hydroxy)phosphinoylmethyl]glycine as the normal potassium salt. pH-Metric titration was used to determine the ionization constants of N,N-bis[butoxy(hydroxy)phosphinoylmethyl] -glycine, аs well as the stability constants of its Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes

Complexing Properties of Organophosphorus Analogs of Nitrilotriacetic Acid: Aminotris(O-alkyl methylenephosphonic Acids)

© 2018, Pleiades Publishing, Ltd. A series of tribasic aminotris(O-alkyl methylenephosphonic acids), the closest organophosphorus analogs of nitrilotriacetic acid, a widely known complexone, were synthesized. The acid‒base properties of the synthesized acids were studied, and the stability constants of their 1: 1 complexes with two-charged cations of alkaline-earth and transition metals were determined

EFFECT OF JNK MAPK ON THE REPAIR OF DAMAGED SKELETAL MUSCLE

Regeneration of muscles after injuries, as well as the development of methods that stimulate this process, is an important problem in medicine and biology. The objective of the study was to evaluate the effect of local blocking of mitogen-activated protein kinase (MAPK) activity of the JNK group (c-Jun N-terminal kinase) on the repair of muscle tissue. Materials and methods. The effect of the JNK MAPK SP600125 blocker on the repair of muscle tissue was studied on a model of a skin and muscle wound in Wistar rats. The main group (n = 30) was injected with a drug plate containing SP600125 with a slow release of the active substance, the control group (n = 30) – the plate without the active substance. The number of dividing myosatellites and muscle kidneys in the damage zone was estimated. Results. Experimental studies have shown that when using a drug plate containing a JNK SP600125 blocker with a slow release of the active substance, the number of dividing myosatellites and forming muscle kidneys in the injury zone of the muscle in the main group on the 7th, 14th and 30th days was significantly higher (p < 0.05) than in the control. Conclusion. Local blockade of JNK MAPK in the zone of muscle damage provides the ability to stimulate the repair of damaged skeletal muscle

Prospects for prevention of adhesion process during cardiac surgical interventions

The article is devoted to the problem of prevention of adhesions in cardiac surgery. It was determined that the problem is urgent due to the increase in the number of heart surgeries. The formation of adhesions is a reaction of the body after surgery, which is a stage of healing and partly performs a protective function. Nevertheless, the presence of adhesions violates the mechanical properties of the heart, negatively affects central hemodynamics, complicates the surgeon’s task during repeated surgical interventions and increases the risk of repeated operations.It has been shown that at present, for the prevention of adhesions, researchers tend to use biodegradable barrier materials with biocompatibility and the ability to dissolve after performing the barrier function. The main anti-adhesion agents used in cardiac surgery are membranes and gels. The requirements for an “ideal” agent for the prevention of adhesion were determined: biocompatibility, no irritating effect, no effect on wound healing, suppression of the growth of connective tissue in the pericardium.Conclusions. Until now, none of the funds has all the necessary qualities to prevent adhesion in the pericardium. Therefore, the search for effective methods for the prevention of postoperative adhesions remains relevant for cardiac surgery

Dynamics of the Activity of MAP-Kinase Cascades in the Healing Process of Postoperative Musculocutaneous Wounds

Background. Management of the reparative process is an urgent task of modern medicine. In our opinion, the development of pathogenetically grounded approaches to optimizing the repair process for managing the interrelations of stromal cells is promising. One of the promising areas in this regard is the impact on the MAPK-cascades.Aim: to study the expression of MAP-kinase mechanisms in the regulation of repair by the example of a musculocutaneous wound.Methods. A linear muscular skin wound was modeled using Wistar rats weighing 220–250 g at the age of 9 months (n = 24). Immunofluorescence staining was performed to detect the activity of p38, JNK, and ERK MAPK cascades from 1 to 30 days.Results. It was established that specific staining in the area of connective tissue formation during staining with p38 MAPK and its phosphorylated form was first observed on the 3rd day, and its maximum severity occurred at the same time. On the 7th and 14th day, small zones in the area of scar formation were minimally stained. The phosphorylated part of the JNK-cascade in the zone of traumatic injury was detected starting from the 1st day after the injury. Bright color persisted on the 3rd day. On the 7th day, the color was minimal, and by the 14th day a second wave of expression was observed. ERK-staining was observed from the 1st to the 14th day with a peak activity on the 3rd day.Conclusion. Thus, we revealed the simultaneous involvement of p38, JNK-, and ERK-cascades in the regulation of the reparative process in the conditions of a musculoskeletal wound. At the same time, it is noteworthy that the peak activity of all cascades coincides and falls on the 3rd day

Postconditioning as a method tissue survivability enhancement in ischemic damage

The article presents the present-day data on the phenomenon of ischemic myocardial postconditioning. It has been shown, that this phenomenon consists in protection of the heart from reperfusion damage by the means of short episodes of ischemia/reperfusion performed at the early stage after prolonged ischemia. It is presented that postconditioning effect manifests in limiting the size of infarction and preserving endothelial function in the region exposed to ischemic injury. The article reports on the modern concept of role of various intracellular signal cascades in providing survival of the cell after the episode of ischemia/reperfusion. Much attention is given to changing in the state of pores localized in internal mitochondrial membrane as end links of realization of postconditioning effect. Prospects of clinical use of postconditioning are very optimistic due to the fact that application of different variants of preconditioning is limited because in most cases it is impossible to predict the time of occurrence of ischemic injury, whereas postconditioning may be used after prolonged ischemia

Effect of p38 MAPK Inhibition on Apoptosis Marker Expression in the Process of Peritoneal Adhesion Formation

Background: Apoptosis, one of the most important mechanisms for maintaining homeostasis, is carried out under both physiological and pathological conditions. The aim of our study was to investigate the expression of markers of apoptosis through caspase-dependent and caspase-independent pathways during the reparative regeneration after serosal injuries of the peritoneum in the context of the prolonged p38 MAPK inhibition. Methods: Peritoneal adhesions in the animal models were induced by a method developed by the authors that included opening the serous-muscular layer of the caecum with a 1cm cut followed by closing the wound with a Schmieden suture and scarifying a 1.5×1.5 cm area of the parietal peritoneum of the right lateral channel. Experiments were carried out on male 9-month-old Wistar rats. When closing the wound, control animals were intraperitoneally administered 3 mL of 0.9% sodium chloride solution (n=40) while experimental group rats were administered slow-release drug Seroguard® (Pharmasyntez JSC) (n=40). Animals were sacrificed within the period of 2 hours to 30 days post surgery. Expression of apoptosis markers was studied by immunohistochemical (Bcl-2, Bcl-x) and immunofluorescent (PARP-1) staining. Results: It is interesting that, in cases of the natural regeneration of the peritoneal injury, expression of anti-apoptosis markers at the injury site came in two waves: it was the most pronounced on days 1–3 post surgery while the second peak of activity was observed on day 14. Within this time window, granulation tissue was actively growing and mature connective-tissue vascularized adhesions were being formed. By the end of the observation period (day 30), expression of anti-apoptosis proteins at the injury site became extremely low and a significant reduction in the amount of connective tissue cells was observed. It was found that a prolonged inhibition of the p38 activity resulted in a moderate increase in Bcl-2 expression on days 3–7, and a decrease in the activity on day 14 was followed by another increase in expression by day 30. The Bcl-xl expression was observed 12 hours to 3 days post surgery and then it went down to the minimum. Positive PARP-1 staining observed on days 3 to 30, which reached its maximum on day 14, was also typical of the experimental group. Conclusion: The performed study demonstrated that a prolonged p38 MAPK inhibition in the adhesion formation models results in the activation of fibroblast apoptosis at the reparation site, which, in the authors’ opinion, predetermines a significant decrease in the adhesion formation in the experimental group

Inducement of experimental Abdominal Adhesions (literature review)

Adhesive disease of the abdominal cavity is a common medical problem that impairs the patients’ life quality. Adhesive intestinal obstruction ranks first in the structure of acute bowel obstruction. The levels of complications and postoperative mortality are not likely to decrease. Consequently, the studies on preventing adhesive disease are still in progress, which requires an animal model to induce abdominal adhesive process. Numerous factors of peritoneum injury result in adhesion formation. Experimental surgery offers various techniques of inducing the adhesive process in the abdominal cavity based on mechanical, chemical, biological, implantation injury factors. Recent trends in intra-abdominal adhesion stimulation are designed to approximate at maximum an animal model and present surgical and gynecologic procedures. In the review article, we survey and systematize different ways of inducing intra-abdominal adhesive process with various injury factors. The choice of study animal, the ways of peritoneum injury, followed by septic or aseptic inflammation are analyzed. The rating scales for the severity of adhesive process are also organized and compared. The number of existing models is large which is evident of the outstanding problem and promising outlook of scientific research

Synthesis, acid-base and complexing properties of N,N,N′,N′-tetrakis(O-butylhydroxyphosphorylmethyl)-1,2-diaminoethane

© 2017, Pleiades Publishing, Ltd. A method of synthesis of organophosphorus analog of ethylenediaminetetraacetic acid (a common complexon), N,N,N′,N′-tetrakis(O-butylhydroxyphosphorylmethyl)-1,2-diaminoethane, has been elaborated. The product structure has been elucidated by means of NMR spectroscopy and X-ray diffraction analysis. Constants of the acid dissociation and the stability of the 1 : 1 complexes with Co(II), Ni(II), and Cu(II) ions have been determined