A Critical Review of the Design, Manufacture, and Evaluation of Bone Joint Replacements for Bone Repair

With the change of people’s living habits, bone trauma has become a common clinical disease. A large number of bone joint replacements is performed every year around the world. Bone joint replacement is a major approach for restoring the functionalities of human joints caused by bone traumas or some chronic bone diseases. However, the current bone joint replacement products still cannot meet the increasing demands and there is still room to increase the performance of the current products. The structural design of the implant is crucial because the performance of the implant relies heavily on its geometry and microarchitecture. Bionic design learning from the natural structure is widely used. With the progress of technology, machine learning can be used to optimize the structure of bone implants, which may become the focus of research in the future. In addition, the optimization of the microstructure of bone implants also has an important impact on its performance. The widely used design algorithm for the optimization of bone joint replacements is reviewed in the present study. Regarding the manufacturing of the implant, the emerging additive manufacturing technique provides more room for the design of complex microstructures. The additive manufacturing technique has enabled the production of bone joint replacements with more complex internal structures, which makes the design process more convenient. Numerical modeling plays an important role in the evaluation of the performance of an implant. For example, theoretical and numerical analysis can be carried out by establishing a musculoskeletal model to prepare for the practical use of bone implants. Besides, the in vitro and in vivo testing can provide mechanical properties of bone implants that are more in line with the implant recipient’s situation. In the present study, the progress of the design, manufacture, and evaluation of the orthopedic implant, especially the joint replacement, is critically reviewed.

Reliquary Cross with Niello from the Upper Dzulat Hillfort in North Ossetia

The present paper deals with the results of the study of manufacturing technique and metal chemical composition carried out for encolpia nielloed cross dated to the end of the 12th – early 13th from the North Caucasus. Analytical results were obtained with a scanning electron microscope equipped with micro ED-XRF in low-vacuum conditions. An eightpointed cross filled with niello was depicted on the survive valve of encolpia. The Christ letter monograms encrusted with niello were made on the cross rounded terminals. Reliquary cross could have been cast in piece-mould made by the impression of previously made encolpia valve. High-tin gunmetal (Sn –17,5%) was used for encolpia production. Recessions for niello were made by casting and left without further treatment. Niello composition comprises copper, tin, and lead sulfides. Sulfur content obtained for several samples exceed 30%. The copper-based niello was more available and cheaper than silver-based composition. It has been widely used for production of the Old Russian pectoral crosses cast of bronze or brass. Manufacturing technique, metal composition, and peculiar niello recipe put encolpia cross from the Upper Dzulat hillfort on a par with widespread Old Russian reliquary crosses dated to the 12th – 13th centuries. There were prestigious but serial items made of cheap copper alloys decorated with cheap niello made without silver. The Old Russian origin of encolpia from the North Caucasus proves by the long list of analogies from the territories of Ukraine, Crimea, Bryansk, Suzdal and Ryazan Lands.

Active narrowband filter based on 2.5D metasurface from Ge2Sb2Te5

We propose a new concept of an active narrowband filter based on a 2.5D metasurface from Ge2Sb2Te5 (GST). In this paper, we present a numerical calculation of the transmission spectrum from a structure of ellipsoids of revolution. For this 2.5D metasurface, modulation of narrow peaks in the IR range for s- and p-polarization is shown. A manufacturing technique using two-photon lithography and laser electrodispersion is proposed.

Research of creating mold for crayons with use of additive manufacturing technique

For crayons manufacturing are often used big mold from steel. These molds are good for mass production, however they tend to be expensive and not suitable for low volume of production. Goal of this paper is to figure out, if these molds can be created by additive manufacturing technique, what materials are suitable for the job and how final products compare with products on the market manufactured with traditional methods.

Bioprinting Technology in Skin, Heart, Pancreas and Cartilage Tissues: Progress and Challenges in Clinical Practice

Bioprinting is an emerging additive manufacturing technique which shows an outstanding potential for shaping customized functional substitutes for tissue engineering. Its introduction into the clinical space in order to replace injured organs could ideally overcome the limitations faced with allografts. Presently, even though there have been years of prolific research in the field, there is a wide gap to bridge in order to bring bioprinting from “bench to bedside”. This is due to the fact that bioprinted designs have not yet reached the complexity required for clinical use, nor have clear GMP (good manufacturing practices) rules or precise regulatory guidelines been established. This review provides an overview of some of the most recent and remarkable achievements for skin, heart, pancreas and cartilage bioprinting breakthroughs while highlighting the critical shortcomings for each tissue type which is keeping this technique from becoming widespread reality.

МАГИЧЕСКИЙ АТРИБУТ: МЕЖДУ ЯЗЫЧЕСТВОМ И ИСЛАМОМ

Целью исследования является изучение башкирских амулетов «бетеү», небольшая коллекция которых хранится в фондах Национального музея Республики Башкортостан. В музейном собрании отложились несколько типов «бетеү», бытовавших на рубеже XIX–XX вв. Предметы отличаются друг от друга формой, материалом, техникой изготовления и имеют разное содержание. Амулетам придавались магико-охранительные и сакральные свойства. Согласно древним поверьям башкир, «бетеү» приносит хозяину здоровье, долголетие, удачу во всех делах и оберегает от сглаза и влияния зловредных духов (духов болезней, шайтана и др.). Самым распространенным видом были треугольной формы амулеты, с вложенной в него молитвой или, реже, предметом. Такие кожаные амулеты-футляры носились на шнурке на шее как обереги или подшивались к одежде с внутренней стороны. Аналогичные обережные амулеты бытовали у многих народов, в том числе у среднеазиатских. Башкирские «бетеү» как магический предмет имели широкое распространение в прошлом и все еще популярны в настоящее время среди населения, прежде всего, пожилого возраста. Поэтому они представляют собой важный этнографический источник для изучения духовной и материальной культуры башкирского народа. The research aims to study the Bashkir amulets "beteu", a small collection of which is kept in the funds of the National Museum of the Republic of Bashkortostan. The collection possesses several types of "beteu", used at the turn of the 19th-20th centuries. Objects differ from each other in shape, material, manufacturing technique, and usage. Magical, protective and sacred properties were attributed to the amulets. The Bashkirs believed that "beteu" brought health, longevity, good luck, and protection from the harmful influence of otherworldly forces. Triangular amulets were the most common, with a prayer or, less often, an object embedded in it. Such leather amulets were worn on a cord around the neck or were sewn to clothes from the inside. Many Central Asian peoples used similar amulets. The Bashkir "beteu", a magical object of cult and ritual significance, combines the pre-Islamic beliefs and the Muslim religion. Therefore, they represent an important ethnographic source for studying the spiritual and material culture of the Bashkir people.

Adverse events and preventive measures related to COVID-19 vaccines

The coronavirus disease 2019 (COVID-19) vaccines are categorized according to the manufacturing technique, including mRNA vaccines and adenovirus vector vaccines. According to previous studies, the reported efficacy of the COVID-19 vaccine is excellent regardless of the type of vaccine, and the majority of studies have shown similar results for safety. Most of the adverse reactions after vaccination were mild or moderate grade, and severe reactions were reported in a very small proportion. However, the adverse reactions that might occur after nationwide vaccinations can contribute to crowding of emergency departments, and this can further lead to significant obstacles to providing necessary treatment for life-threatening conditions. Therefore, as emergency physicians, we would like to present some concerns and suggestions to prevent these predictable problems.