Polymers Everyday and Everywhere

2017 ◽  
Vol 39 (4) ◽  
Author(s):  
Daniel Rabinovich

AbstractI recently looked back at all the notes I’ve written for Chemistry International during the past decade or so, and polymer chemistry seems to be a recurrent theme, with a range of topics that underscores the multifarious applications of polymeric materials, both natural and synthetic. For example, the common polypropylene stacking chair, created in 1962 by Robin Day, one of the most influential furniture designers of the 20th century, was featured on a British stamp used to illustrate a Stamps International article published in 2011.

1993 ◽  
Vol 1 (2) ◽  
pp. 197-206
Author(s):  
Geoffrey Allen

We still have much to learn about the morphologies of natural and synthetic polymers crystallized in bulk. Nevertheless, conventional X-ray and thermodynamic studies of crystallinity in polymeric materials over the past 60 years have given us a clear picture of the concept of crystallinity and the molecular features which promote crystallinity in these substances. Apart from issues of chain connectivity, the science of conventional molecules proved adequate for the task!


2006 ◽  
Vol 59 (8) ◽  
pp. 508 ◽  
Author(s):  
Igor Lacík

Polymeric materials have been successfully used in numerous medical applications because of their diverse properties. For example, development of a bioartificial pancreas remains a challenge for polymer chemistry. Polymers, as a form of various encapsulation device, have been proposed for designing the semipermeable membrane capable of long-term immunoprotection of transplanted islets of Langerhans, which regulate the blood glucose level in a diabetic patient. This review describes the current situation in the field, discussing aspects of material selection, encapsulation devices, and encapsulation protocols. Problems and unanswered questions are emphasized to illustrate why clinical therapies with encapsulated islets have not been realized, despite intense activity over the past 15 years. The review was prepared with the goal to address professionals in the field as well as the broad polymer community to help in overcoming final barriers to the clinical phase for transplantation of islets of Langerhans encapsulated in a polymeric membrane.


2020 ◽  
Vol 63 (4) ◽  
pp. 363-376
Author(s):  
M. Lindeijer S.J.

Miracles, like the saints, are one of the most wondrous parts of the life of the Church since the earliest times. As ‘the finger of God’ pointing to sanctity (pope Francis), they play a particular role in canonization. The procedures to ascertain miracles, 95% of them healings, have been refined over the past four centuries, particularly in the 20th century, which also saw fundamental developments in the theology of miracles. Since 1983 fewer miracles have been required for a beatification or canonization. Some candidates for sainthood have been raised to the altar on the basis of a single miracle, based on the common intercession of the saints.


2017 ◽  
Vol 2 (3) ◽  

For almost 20 years after the end of World War II, many Japanese women were challenged by a dark secondary hyper pigmentation on their faces. The causation of this condition was unknown and incurable at the time. However this symptom became curable after a number of new cosmetic allergens were discovered through patch tests and as an aftermath, various cosmetics and soaps that eliminated all these allergens were put into production to be used exclusively for these patients. An international research project conducted by seven countries was set out to find out the new allergens and discover non-allergic cosmetic materials. Due to these efforts, two disastrous cosmetic primary sensitizers were banned and this helped to decrease allergic cosmetic dermatitis. Towards the end of the 20th century, the rate of positives among cosmetic sensitizers decreased to levels of 5% - 8% and have since maintained its rates into the 21th century. Currently, metal ions such as the likes of nickel have been identified as being the most common allergens found in cosmetics and cosmetic instruments. They often produce rosacea-like facial dermatitis and therefore allergen controlled soaps and cosmetics have been proved to be useful in recovering normal skin conditions.


2019 ◽  
Vol 7 (3) ◽  
pp. 3-23
Author(s):  
Viara Gyurova

Since the beginning of the last decade of the past 20th century, Bulgaria has entered a new, complex stage of its development, with many reforms. Education and teacher training reforms are influenced by the global and European trends, as well as by the national changes (political, economical, social, and technological). The author analyses the main characteristics of the changed teacher training system and teacher qualification and development system. Some of the challenges and directions of the transformation and future development of the teacher education and qualification in Bulgaria are discussed.


2020 ◽  
Vol 2020 (11-1) ◽  
pp. 263-279
Author(s):  
Alexander Kodintsev ◽  
Danil Rybin

The study analyzes historical researches on the life and work of the outstanding Russian lawyer A. F. Koni. It is noted that several directions in the study of the personality of this figure can be distinguished. It is concluded that systematic study of the legacy of Koni in the context of the era, taking into account the accumulated knowledge, coupled with archival materials will recreate the real face of the remarkable humanist figure of Russia in the past era.


2020 ◽  
Vol 15 (7) ◽  
pp. 588-596
Author(s):  
Haibao Zhang ◽  
Guodong Zhu

Renal cell carcinoma (RCC) is one of the common urologic neoplasms, and its incidence has been increasing over the past several decades; however, its pathogenesis is still unknown up to now. Recent studies have found that in addition to tumor cells, other cells in the tumor microenvironment also affect the biological behavior of the tumor. Among them, macrophages exist in a large amount in tumor microenvironment, and they are generally considered to play a key role in promoting tumorigenesis. Therefore, we summarized the recent researches on macrophage in the invasiveness and progression of RCC in latest years, and we also introduced and discussed many studies about macrophage in RCC to promote angiogenesis by changing tumor microenvironment and inhibit immune response in order to activate tumor progression. Moreover, macrophage interactes with various cytokines to promote tumor proliferation, invasion and metastasis, and it also promotes tumor stem cell formation and induces drug resistance in the progression of RCC. The highlight of this review is to make a summary of the roles of macrophage in the invasion and progression of RCC; at the same time to raise some potential and possible targets for future RCC therapy.


Author(s):  
Piero Ignazi

Chapter 1 introduces the long and difficult process of the theoretical legitimation of the political party as such. The analysis of the meaning and acceptance of ‘parties’ as tools of expressing contrasting visions moves forward from ancient Greece and Rome where (democratic) politics had first become a matter of speculation and practice, and ends up with the first cautious acceptance of parties by eighteenth-century British thinkers. The chapter explores how parties or factions have been constantly considered tools of division of the ‘common wealth’ and the ‘good society’. The holist and monist vision of a harmonious and compounded society, stigmatized parties and factions as an ultimate danger for the political community. Only when a new way of thinking, that is liberalism, emerged, was room for the acceptance of parties set.


Author(s):  
Deborah Tollefsen

When a group or institution issues a declarative statement, what sort of speech act is this? Is it the assertion of a single individual (perhaps the group’s spokesperson or leader) or the assertion of all or most of the group members? Or is there a sense in which the group itself asserts that p? If assertion is a speech act, then who is the actor in the case of group assertion? These are the questions this chapter aims to address. Whether groups themselves can make assertions or whether a group of individuals can jointly assert that p depends, in part, on what sort of speech act assertion is. The literature on assertion has burgeoned over the past few years, and there is a great deal of debate regarding the nature of assertion. John MacFarlane has helpfully identified four theories of assertion. Following Sandy Goldberg, we can call these the attitudinal account, the constitutive rule account, the common-ground account, and the commitment account. I shall consider what group assertion might look like under each of these accounts and doing so will help us to examine some of the accounts of group assertion (often presented as theories of group testimony) on offer. I shall argue that, of the four accounts, the commitment account can best be extended to make sense of group assertion in all its various forms.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 688
Author(s):  
Khaled Alhammadi ◽  
Luna Santos-Roldán ◽  
Luis Javier Cabeza-Ramírez

The past few years have seen significant demographic changes in most regions, including an increased elderly population. Subsequently, elderly citizens comprise an important market segment of consumers, with the food industry one of the most affected areas in this context. However, food market managers previously believed that elderly consumers’ needs were stereotyped in nature. The lack of focus on this sector, therefore, left elderly consumers as an untapped market, without realizing the financial independence of this segment regarding their nutrition. This research will attempt to provide the key determinant factors on elderly consumers’ behavior related to food. For that purpose, a complete literature review of more than 123 papers regarding these concepts has been carried out. Once analyzed, we highlight the common insights to give clear guidance for supermarket managers and food manufacturers to have a better knowledge of the reasons behind elderly people’s food acquisitions.


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