scholarly journals Light and Hydrogels: A New Generation of Antimicrobial Materials

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 787
Author(s):  
Lucie Pierau ◽  
Davy-Louis Versace
Keyword(s):  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Green Process ◽  
Health Crisis ◽  
The Past ◽  
Crosslinking Process ◽  
Antimicrobial Materials ◽  
Innovative Solutions ◽  
Photochemical Crosslinking ◽  
New Generation

Nosocomial diseases are becoming a scourge in hospitals worldwide, and new multidrug-resistant microorganisms are appearing at the forefront, significantly increasing the number of deaths. Innovative solutions must emerge to prevent the imminent health crisis risk, and antibacterial hydrogels are one of them. In addition to this, for the past ten years, photochemistry has become an appealing green process attracting continuous attention from scientists in the scope of sustainable development, as it exhibits many advantages over other methods used in polymer chemistry. Therefore, the combination of antimicrobial hydrogels and light has become a matter of course to design innovative antimicrobial materials. In the present review, we focus on the use of photochemistry to highlight two categories of hydrogels: (a) antibacterial hydrogels synthesized via a free-radical photochemical crosslinking process and (b) chemical hydrogels with light-triggered antibacterial properties. Numerous examples of these new types of hydrogels are described, and some notions of photochemistry are introduced.

scholarly journals Multimetallic Nanoparticles as Alternative Antimicrobial Agents: Challenges and Perspectives

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 912
Author(s):  
Nagaraj Basavegowda ◽  
Kwang-Hyun Baek
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Synthetic Methods ◽  
Research Progress ◽  
Resistant Bacteria ◽  
Antimicrobial Materials ◽  
Species Production ◽  
Protein Dysfunction

Recently, infectious diseases caused by bacterial pathogens have become a major cause of morbidity and mortality globally due to their resistance to multiple antibiotics. This has triggered initiatives to develop novel, alternative antimicrobial materials, which solve the issue of infection with multidrug-resistant bacteria. Nanotechnology using nanoscale materials, especially multimetallic nanoparticles (NPs), has attracted interest because of the favorable physicochemical properties of these materials, including antibacterial properties and excellent biocompatibility. Multimetallic NPs, particularly those formed by more than two metals, exhibit rich electronic, optical, and magnetic properties. Multimetallic NP properties, including size and shape, zeta potential, and large surface area, facilitate their efficient interaction with bacterial cell membranes, thereby inducing disruption, reactive oxygen species production, protein dysfunction, DNA damage, and killing potentiated by the host’s immune system. In this review, we summarize research progress on the synergistic effect of multimetallic NPs as alternative antimicrobial agents for treating severe bacterial infections. We highlight recent promising innovations of multimetallic NPs that help overcome antimicrobial resistance. These include insights into their properties, mode of action, the development of synthetic methods, and combinatorial therapies using bi- and trimetallic NPs with other existing antimicrobial agents.

The Contribution of Intermediate-Voltage, High-Resolution Electron Microscopy In Materials Science: An Appraisal

1990 ◽  
Vol 48 (1) ◽  
pp. 478-479
Author(s):  
John L. Hutchison
Keyword(s):  
High Resolution ◽  
Materials Science ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
The Past ◽  
Resolution Electron ◽  
Extreme Sensitivity ◽  
Electron Microscopes ◽  
New Generation ◽  
Small Metal Particles

Over the past five years or so the development of a new generation of high resolution electron microscopes operating routinely in the 300-400 kilovolt range has produced a dramatic increase in resolution, to around 1.6 Å for “structure resolution” and approaching 1.2 Å for information limits. With a large number of such instruments now in operation it is timely to assess their impact in the various areas of materials science where they are now being used. Are they falling short of the early expectations? Generally, the manufacturers’ claims regarding resolution are being met, but one unexpected factor which has emerged is the extreme sensitivity of these instruments to both floor-borne and acoustic vibrations. Successful measures to counteract these disturbances may require the use of special anti-vibration blocks, or even simple oil-filled dampers together with springs, with heavy curtaining around the microscope room to reduce noise levels. In assessing performance levels, optical diffraction analysis is becoming the accepted method, with rotational averaging useful for obtaining a good measure of information limits. It is worth noting here that microscope alignment becomes very critical for the highest resolution.In attempting an appraisal of the contributions of intermediate voltage HREMs to materials science we will outline a few of the areas where they are most widely used. These include semiconductors, oxides, and small metal particles, in addition to metals and minerals.

Molecular Epidemiology and Biomarkers in Etiologic Cancer Research: The New in Light of the Old

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Gene Expression ◽  
Cancer Research ◽  
Molecular Epidemiology ◽  
Exposure Assessment ◽  
Large Scale ◽  
First Generation ◽  
Cancer Epidemiology ◽  
Policy Changes ◽  
The Past ◽  
New Generation

The purpose of this review is to evaluate progress inmolecular epidemiology over the past 24 years in canceretiology and prevention to draw lessons for futureresearch incorporating the new generation of biomarkers.Molecular epidemiology was introduced inthe study of cancer in the early 1980s, with theexpectation that it would help overcome some majorlimitations of epidemiology and facilitate cancerprevention. The expectation was that biomarkerswould improve exposure assessment, document earlychanges preceding disease, and identify subgroupsin the population with greater susceptibility to cancer,thereby increasing the ability of epidemiologic studiesto identify causes and elucidate mechanisms incarcinogenesis. The first generation of biomarkers hasindeed contributed to our understanding of riskandsusceptibility related largely to genotoxic carcinogens.Consequently, interventions and policy changes havebeen mounted to reduce riskfrom several importantenvironmental carcinogens. Several new and promisingbiomarkers are now becoming available for epidemiologicstudies, thanks to the development of highthroughputtechnologies and theoretical advances inbiology. These include toxicogenomics, alterations ingene methylation and gene expression, proteomics, andmetabonomics, which allow large-scale studies, includingdiscovery-oriented as well as hypothesis-testinginvestigations. However, most of these newer biomarkershave not been adequately validated, and theirrole in the causal paradigm is not clear. There is a needfor their systematic validation using principles andcriteria established over the past several decades inmolecular cancer epidemiology.

Vēsturiskā atmiņa Latvijas teātra jaunās paaudzes mākslinieku darbos: izrādes „Dvēseļu utenis” piemērs

2020 ◽  
pp. 269-275
Author(s):  
Ieva Rodiņa
Keyword(s):  
Historical Memory ◽  
Intergenerational Relationships ◽  
Phenomenological Approach ◽  
Political Theater ◽  
Hermeneutic Phenomenological ◽  
The Past ◽  
The Social ◽  
Humanistic Study ◽  
New Generation ◽  
Flea Market

The aim of the research “Historical Memory in the Works of the New Generation of Latvian Theater Artists: The Example of “The Flea Market of the Souls” is to focus on the current but at the same time little discussed topic in Latvian theater – the change of generations and the social processes connected to it, that are expressed on the level of world views, experiences, intergenerational relationships. Most directly, these changes are reflected in the phenomenon of historical memory. The concept of “postmemory” was defined by German professor Marianne Hirsch in 1992, suggesting that future generations are closely related to the personal and collective cultural traumas of previous generations, which are passing on the past experience through historical memory, thus affecting the present. Grotesque, self-irony, and focusing on socio-political, provocative questions and themes are the connecting point of the generation of young Latvian playwrights born in the late 1980s and early 1990s, including such personalities as Jānis Balodis, Rasa Bugavičute-Pēce, Matīss Gricmanis, Justīne Kļava, etc. However, unlike Matīss Gricmanis or Janis Balodis who represent the aesthetics of political theater, in Justīne Kļava’s works, sociopolitical processes become the background of a generally humanistic study of the relationships between generations. This theme is represented not only in “The Flea Market of the Souls”, but also in other plays, like “Jubilee ‘98” and “Club “Paradise””. The tendency to investigate the traces left by the Soviet heritage allows to define these works as autobiographical researches of the identity of the post-Soviet generation, analyzing life in today's Latvia in terms of historical memory. Using the semiotic, hermeneutic, phenomenological approach, the play “The Flea Market of the Souls” and its production in Dirty Deal Teatro (2017) are analyzed as one of the most vivid works reflecting the phenomenon of historical memory in recent Latvian original drama.

The Twenty-first Century

2018 ◽  
Author(s):  
Alexander Gillespie
Keyword(s):  
Environmental Sustainability ◽  
First Century ◽  
Bad News ◽  
Good News ◽  
Species Loss ◽  
The Past ◽  
Scientific Terms ◽  
Twenty First Century ◽  
Open Question ◽  
New Generation

The cumulative environmental challenge of sustainable development in the twenty-first century is larger than anything humanity has ever had to deal with in the past. The good news is that solid progress is being reached in the understanding of issues in scientific terms and understanding what needs to be done. The bad news is twofold. First, although many of the environmental problems of earlier centuries are now being confronted, a new generation of difficulties is eclipsing what were the older difficulties. Secondly, much of the progress is being achieved by the wealthier parts of the planet, rather than the developing world. From population growth to climate change to unprecedented habitat and species loss, whether environmental sustainability can be achieved in the twenty-first century is an open question.

scholarly journals A novel chemical biology and computational approach to expedite the discovery of new-generation polymyxins against life-threatening Acinetobacter baumannii

2021 ◽  
Author(s):  
Xukai Jiang ◽  
Nitin A. Patil ◽  
Mohammad A. K. Azad ◽  
Hasini Wickremasinghe ◽  
Heidi Yu ◽  
...  
Keyword(s):  
Public Health ◽  
Chemical Biology ◽  
Multidrug Resistant ◽  
Computational Approach ◽  
Gram Negative Bacteria ◽  
Global Public Health ◽  
Gram Negative ◽  
Life Threatening ◽  
New Generation ◽  
Novel Antibiotics

Multidrug-resistant Gram-negative bacteria have been an urgent threat to global public health. Novel antibiotics are desperately needed to combat these 'superbugs'.

scholarly journals The evolution of Darwinian sexualities

BJHS Themes ◽  
2021 ◽  
pp. 1-23
Author(s):  
Erika Lorraine Milam
Keyword(s):  
Gay Rights ◽  
First Century ◽  
Sexual Practices ◽  
Past Century ◽  
Sexual Preferences ◽  
The Past ◽  
Sexual Behaviours ◽  
Late Twentieth ◽  
New Generation ◽  
Descent Of Man

Abstract Charles Darwin's Descent of Man was suffused with questions of courtship, mating and sex. Following in his footsteps, biologists throughout the twentieth century interrogated the sexual behaviour of humans and animals. This paper charts the fate of evolutionary theories of sexuality to argue that – despite legal and social gains of the past century – when biologists used sexual selection as a tool for theorizing the evolution of homosexual behaviour (which happened only rarely), the effect of their theories was to continuously reinscribe normative heterosexuality. If, at the end of the nineteenth century, certain sex theorists viewed homosexuality as a marker of intermediate sex, by the late twentieth a new generation of evolutionary theorists idealized gay men as hyper-masculine biological males whose sexual behaviours were uncompromised by the necessity of accommodating women's sexual preferences. In both cases, normative assumptions about gender were interwoven with those about sexuality. By the twenty-first century, animal exemplars were again mobilized alongside data gathered about human sexual practices in defence of gay rights, but this time by creating the opportunity for naturalization without recourse to biological determinism.

scholarly journals Antibacterial Activity of Moroccan Zantaz Honey and the Influence of Its Physicochemical Parameters Using Chemometric Tools

2021 ◽  
Vol 11 (10) ◽  
pp. 4675
Author(s):  
Youssef Elamine ◽  
Hamada Imtara ◽  
Maria Graça Miguel ◽  
Ofélia Anjos ◽  
Letícia M. Estevinho ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Principal Component ◽  
Physicochemical Characteristics ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Coumaric Acid ◽  
Atlas Mountains ◽  
Methyl Syringate ◽  
Chemometric Tools

The emergence of multidrug-resistant bacteria has prompted the development of alternative therapies, including the use of natural products with antibacterial properties. The antibacterial properties of Zantaz honey produced in the Moroccan Atlas Mountains against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was evaluated and analyzed using chemometric tools. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) against S. aureus were the lowest (112.5 ± 54.5 mg/mL), revealing that this species was most sensitive to Zantaz honey. P. aeruginosa showed an intermediate sensitivity (MIC= 118.75 ± 51.9 mg/mL), while E. coli was the most resistant to treatment (MIC = 175 ± 61.2 mg/mL). Content of monosaccharides, certain minerals, and phenolic compounds correlated with antibacterial activity (p < 0.05). Principal component analysis of physicochemical characteristics and antibacterial activity indicated that the parameters most associated with antibacterial activity were color, acidity, and content of melanoidins, fructose, epicatechin, methyl syringate, 4-coumaric acid, and 3-coumaric acid.

Antibacterial properties of phenothiazine derivatives against multidrug‐resistant Acinetobacter baumannii strains

2021 ◽  
Author(s):  
Laura Aguilar‐Vega ◽  
Luis Esaú López‐Jácome ◽  
Bernardo Franco ◽  
Sergio Muñoz‐Carranza ◽  
Naurú Vargas‐Maya ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Phenothiazine Derivatives

scholarly journals The Synergistic Effect of Biosynthesized Silver Nanoparticles and Phage ZCSE2 as a Novel Approach to Combat Multidrug-Resistant Salmonella enterica

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Abdallah S. Abdelsattar ◽  
Rana Nofal ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
Amera Taha ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Color Change ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Mortality And Morbidity ◽  
Novel Approach ◽  
Transmission Electron

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.

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