Thiophene-Based Trimers and Their Bioapplications: An Overview

Certainly, the success of polythiophenes is due in the first place to their outstanding electronic properties and superior processability. Nevertheless, there are additional reasons that contribute to arouse the scientific interest around these materials. Among these, the large variety of chemical modifications that is possible to perform on the thiophene ring is a precious aspect. In particular, a turning point was marked by the diffusion of synthetic strategies for the preparation of terthiophenes: the vast richness of approaches today available for the easy customization of these structures allows the finetuning of their chemical, physical, and optical properties. Therefore, terthiophene derivatives have become an extremely versatile class of compounds both for direct application or for the preparation of electronic functional polymers. Moreover, their biocompatibility and ease of functionalization make them appealing for biology and medical research, as it testifies to the blossoming of studies in these fields in which they are involved. It is thus with the willingness to guide the reader through all the possibilities offered by these structures that this review elucidates the synthetic methods and describes the full chemical variety of terthiophenes and their derivatives. In the final part, an in-depth presentation of their numerous bioapplications intends to provide a complete picture of the state of the art.

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Synthetic Routes to 2-Iminothiazolidines: State-of-the-Art 2006-2020

Current Organic Chemistry ◽

10.2174/1385272824999201019162400 ◽

2020 ◽

Vol 24 (24) ◽

pp. 2823-2844

Author(s):

Aditya Bhattacharyya

Keyword(s):

State Of The Art ◽

Biological Significance ◽

Review Article ◽

Synthetic Methods ◽

Pharmacological Properties ◽

Cyclic Molecules ◽

Synthetic Routes

: Multiheteroatom-containing small-sized cyclic molecules such as 2- iminothiazolidines are often found to possess beneficial pharmacological properties. In this review article, the biological significance of 2-iminothiazolidines is discussed and the literature reports published in the last 15 years spanning from 2006 to 2020 describing various preparative routes to access 2-iminothiazolidine derivatives have been categorically and chronologically described. The notable synthetic methods discussed here involve ringexpansion transformations of nonactivated and activated aziridines, thiiranes, epoxides, and other miscellaneous reactions.

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Nutritional Optic Neuropathies: State of the Art and Emerging Evidences

Nutrients ◽

10.3390/nu12092653 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2653

Author(s):

Matilde Roda ◽

Natalie di Geronimo ◽

Marco Pellegrini ◽

Costantino Schiavi

Keyword(s):

Bariatric Surgery ◽

Optic Neuropathy ◽

Multidisciplinary Approach ◽

State Of The Art ◽

Signs And Symptoms ◽

Therapeutic Strategies ◽

Scientific Interest ◽

Optic Nerve Atrophy ◽

Prompt Diagnosis

Nutritional optic neuropathy is a cause of bilateral, symmetrical, and progressive visual impairment with loss of central visual acuity and contrast sensitivity, dyschromatopsia, and a central or centrocecal scotoma. The clinical features are not pathognomonic, since hereditary and toxic forms share similar signs and symptoms. It is becoming increasingly common due to the widespread of bariatric surgery and strict vegetarian or vegan diets, so even the scientific interest has recently increased. In particular, recent studies have focused on possible pathogenetic mechanisms, and on novel diagnostic and therapeutic strategies in order to prevent the onset, make a prompt diagnosis and an accurate nutritional supplementation, and to avoid irreversible optic nerve atrophy. Nowadays, there is clear evidence of the role of cobalamin, folic acid, thiamine, and copper, whereas further studies are needed to define the role of niacin, riboflavin, and pyridoxine. This review aims to summarize the etiology, diagnosis, and treatment of nutritional optic neuropathy, and it is addressed not only to ophthalmologists, but to all physicians who could come in contact with a patient with a possible nutritional optic neuropathy, being a fundamental multidisciplinary approach.

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Excitonic effects in the optical spectra of Li2SiO3 compound

Scientific Reports ◽

10.1038/s41598-021-87269-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nguyen Thi Han ◽

Vo Khuong Dien ◽

Ming-Fa Lin

Keyword(s):

Optical Properties ◽

State Of The Art ◽

Plasmon Mode ◽

First Principle ◽

Response Behavior ◽

Electronic And Optical Properties ◽

Physical Chemical ◽

Excitonic Effects ◽

Energy Loss Functions ◽

Excitonic Effect

AbstractLi2SiO3 compound exhibits unique electronic and optical properties. The state-of-the-art analyses, which based on first-principle calculations, have successfully confirmed the concise physical/chemical picture and the orbital bonding in Li–O and Si–O bonds. Especially, the unusual optical response behavior includes a large red shift of the onset frequency due to the extremely strong excitonic effect, the polarization of optical properties along three-directions, various optical excitations structures and the most prominent plasmon mode in terms of the dielectric functions, energy loss functions, absorption coefficients and reflectance spectra. The close connections of electronic and optical properties can identify a specific orbital hybridization for each distinct excitation channel. The presented theoretical framework will be fully comprehending the diverse phenomena and widen the potential application of other emerging materials.

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Climate and environmental context of the Mongol invasion of Syria and defeat at ‘Ayn Jālūt (1258–1260 CE)

Erdkunde ◽

10.3112/erdkunde.2021.02.02 ◽

2021 ◽

Vol 75 (2) ◽

pp. 87-104

Author(s):

Nicola Di Cosmo ◽

Sebastian Wagner ◽

Ulf Büntgen

Keyword(s):

Strategic Alliances ◽

Turning Point ◽

Environmental Changes ◽

Environmental Variability ◽

State Of The Art ◽

Eastern Mediterranean ◽

The Caucasus ◽

Mountainous Regions ◽

The Past ◽

Climate Reconstructions

After a successful conquest of large parts of Syria in 1258 and 1259 CE, the Mongol army lost the battle of 'Ayn Jālūt against Mamluks on September 3, 1260 CE. Recognized as a turning point in world history, their sudden defeat triggered the reconfiguration of strategic alliances and geopolitical power not only in the Middle East, but also across much of Eurasia. Despite decades of research, scholars have not yet reached consensus over the causes of the Mongol reverse. Here, we revisit previous arguments in light of climate and environmental changes in the aftermath of one the largest volcanic forcings in the past 2500 years, the Samalas eruption ~1257 CE. Regional tree ring-based climate reconstructions and state-of-the-art Earth System Model simulations reveal cooler and wetter conditions from spring 1258 to autumn 1259 CE for the eastern Mediterranean/Arabian region. We therefore hypothesize that the post-Samalas climate anomaly and associated environmental variability affected an estimated 120,000 Mongol soldiers and up to half a million of their horses during the conquest. More specifically, we argue that colder and wetter climates in 1258 and 1259 CE, while complicating and slowing the campaign in certain areas, such as the mountainous regions in the Caucasus and Anatolia, also facilitated the assault on Syria between January and March 1260. A return to warmer and dryer conditions in the summer of 1260 CE, however, likely reduced the regional carrying capacity and may therefore have forced a mass withdrawal of the Mongols from the region that contributed to the Mamluks’ victory. In pointing to a distinct environmental dependency of the Mongols, we offer a new explanation of their defeat at 'Ayn Jālūt, which effectively halted the further expansion of the largest ever land-based empire.

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31.Time

Transactions of the International Astronomical Union ◽

10.1017/s0251107x00010749 ◽

1979 ◽

Vol 17 (1) ◽

pp. 171-184

Author(s):

A Orte

Keyword(s):

State Of The Art ◽

The State ◽

Scientific Interest ◽

Subsequent Research ◽

Primary Standards

The scientific interest in Commission 31 topics and their applicability to new and practical fields is exponentially growing, pushing towards the recognition of new problems and subsequent research. In some cases as in Primary Standards the state of the art seems to be rather close to the actual and imagined needs. In other cases as in worldwide precise and accurate synchronization, we have to recognize that we still are far from the goals.

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Synthesis and characterization of size-controlled silver nanowires

Physical Sciences Reviews ◽

10.1515/psr-2017-0084 ◽

2018 ◽

Vol 3 (11) ◽

Author(s):

Pei Zhang ◽

Shudong Lin ◽

Jiwen Hu

Keyword(s):

Optical Properties ◽

Silver Nanowires ◽

Synthetic Methods ◽

Synthesis And Characterization ◽

Electronic And Optical Properties ◽

The Past ◽

Crucial Effect ◽

Recent Developments ◽

Size Controlled

Abstract Silver nanowires (AgNWs) have attracted attentions form both academia and industry due to their outstanding electronic and optical properties. The AgNW-based devices for various uses were invented in recent years. It is well known that the sizes of AgNWs have a crucial effect on the performance of AgNW-based devices. However, how to synthesize AgNWs with controlled sizes is still unsolved. Researchers reported many methods to synthesize AgNWs with different sizes in the past decade. However, a review that focuses on the synthetic methods of AgNWs is very rare. The aim of this review is to summarize the recent developments that have been achieved with AgNWs, and many procedure details and results and discussions will be provided for practical use. Graphical Abstract:

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Technical viewpoint on polystyrene/graphene nanocomposite

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705720907653 ◽

2020 ◽

pp. 089270572090765

Author(s):

Ayesha Kausar

Keyword(s):

Electromagnetic Interference ◽

High Performance ◽

State Of The Art ◽

Synthetic Methods ◽

Structure Property ◽

Electromagnetic Interference Shielding ◽

Graphene Nanocomposites ◽

Structure Property Relationship ◽

Fundamental Understanding ◽

Graphene Nanocomposite

This review presents state-of-the-art progress in the field of polystyrene (PS)/graphene nanocomposite. Graphene is a monoatomic thick nanoallotrope of carbon. It has attracted tremendous research consideration owing to chemical functionalization aptitude and remarkable physical properties. Graphene has been used as a potential nanofiller to dramatically improve the performance of polymeric nanocomposite. PS is an important synthetic aromatic thermoplastic polymer. Graphene has been used to enhance the mechanical strength, thermal stability, electrical conductivity, and thermal conductivity of PS/graphene nanocomposite. Dispersion routes and synthetic methods of graphene and PS/graphene nanocomposite have also been reviewed. PS/graphene nanocomposites have been explored for anticorrosion, electromagnetic interference shielding, batteries, electrocatalysis, and microextraction applications. In spite of interesting developments, a lot remains to be done with regard to fundamental understanding of structure–property relationship and designing materials to operate for advanced high performance applications. This review is also concluded listing current challenges associated with processing and future perspectives of nanocomposite.

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Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.13.200 ◽

2017 ◽

Vol 13 ◽

pp. 2023-2027 ◽

Cited By ~ 16

Author(s):

Hao Wang ◽

Cui Chen ◽

Weibing Liu ◽

Zhibo Zhu

Keyword(s):

Room Temperature ◽

Synthetic Methods ◽

Chemical Modifications ◽

One Pot ◽

Butyl Hydroperoxide ◽

Radical Intermediates ◽

Mild Conditions ◽

Tert Butyl Hydroperoxide ◽

Potential Applications

We developed a direct vicinal difunctionalization of alkenes with iodine and TBHP at room temperature. This iodination and peroxidation in a one-pot synthesis produces 1-(tert-butylperoxy)-2-iodoethanes, which are inaccessible through conventional synthetic methods. This method generates multiple radical intermediates in situ and has excellent regioselectivity, a broad substrate scope and mild conditions. The iodine and peroxide groups of 1-(tert-butylperoxy)-2-iodoethanes have several potential applications and allow further chemical modifications, enabling the preparation of synthetically valuable molecules.

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Growth, Spectroscopy, and Laser Application of Self-Ordered III-V Quantum Dots

MRS Bulletin ◽

10.1557/s0883769400031249 ◽

1998 ◽

Vol 23 (2) ◽

pp. 31-34 ◽

Cited By ~ 91

Author(s):

D. Bimberg ◽

M. Grundmann ◽

N.N. Ledentsov

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

State Of The Art ◽

Laser Diodes ◽

Threshold Current ◽

High Gain ◽

Gain Medium ◽

Modern Technology ◽

High Quantum Efficiency ◽

Light Emitting

The development and application of semiconductor light-emitting and laser diodes has been a huge success during the last 30 years in key areas of modern technology like communications, recording, and printing. Still there is ample room for improvement through combination of the atomlike properties for zero-dimensionally localized carriers in quantum dots (QDs) with state-of-the-art semiconductor-laser technology. Low, temperature-insensitive threshold current; high gain; and differential gain have been predicted since the early 1980s.In the past two decades, the fabrication of QDs has been attempted using colloidal techniques (see the article by Nozik and Mićić in this issue), patterning, etching, and layer fluctuations (see the article by Gammon in this issue). However a break-through occurred recently through the employment of self-ordering mechanisms during epitaxy of lattice-mismatched materials (see the next section) for the creation of high-density arrays of QDs that exhibit excellent optical properties, particularly high quantum efficiency, up to room temperature. The zero-dimensional carrier confinement and subsequent atomlike electronic properties have a drastic impact on optical properties (see the section on Spectroscopy). Also intimately connected is the applicability of QDs as a novel gain medium in state-of-the-art laser diodes with superior properties (see the section on Lasers).

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