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Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

Most biological phenomena occur at the nanometer scale, which is not accessible by the conventional optical techniques because of the optical diffraction limitation. Tip-enhanced Raman spectroscopy (TERS), one of the burgeoning probing techniques, not only can provide the topography characterization with high resolution, but also can deliver the chemical or molecular information of a sample beyond the optical diffraction limitation. Therefore, it has been widely used in various structural analyses pertaining to materials science, tissue engineering, biological processes and so on. Based on the different feedback mechanisms, TERS can be classified into three types: atomic force microscopy based TERS system (AFM-TERS), scanning tunneling microscopy based TERS system (STM-TERS) and shear force microscopy based TERS system (SFM-TERS). Among them, AFM-TERS is the most widely adopted feedback system by live biosamples because it can work in liquid and this allows the investigation of biological molecules under native conditions. In this review, we mainly focus on the applications of AFM-TERS in three biological systems: nucleic acids, proteins and pathogens. From the TERS characterization to the data analysis, this review demonstrates that AFM-TERS has great potential applications to visually characterizing the biomolecular structure and crucially detecting more nano-chemical information of biological systems.

Fullerenes, a unique allotrope of carbon, have captured significant attention in multiple scientific fields. As a non-destructive characterization technique, Raman spectroscopy has proven indispensable for investigating fullerenes and their derivatives, offering detailed insights into their vibrational properties. This review discusses the broad utility of Raman spectroscopy in revealing the structural and physicochemical characteristics of fullerenes—from the iconic C60 molecule to an array of its derivatives—highlighting its capacity to detect functionalization-induced changes in molecular structure and electronic properties, while also assessing environmental influences such as solvent effects and temperature variations. Particular emphasis is placed on advanced Raman-based techniques, including enhanced Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), and tip-enhanced Raman spectroscopy (TERS), for the characterization of fullerenes and their derivatives. These cutting-edge methods offer high sensitivity and ultra-high spatial resolution, greatly expanding the scope of fullerene research and delivering deeper insights into their structural and functional properties.

From the famous 1918 H1N1 influenza to the present COVID-19 pandemic, the need for improved viral detection techniques is all too apparent. The aim of the present paper is to show that identification of individual virus particles in clinical sample materials quickly and reliably is near at hand. First of all, our team has developed techniques for identification of virions based on a modular atomic force microscopy (AFM). Furthermore, femtosecond adaptive spectroscopic techniques with enhanced resolution via coherent anti-Stokes Raman scattering (FASTER CARS) using tip-enhanced techniques markedly improves the sensitivity [M. O. Scully, et al., Proc. Natl. Acad. Sci. U.S.A. 99, 10994–11001 (2002)].

In this article, tip-enhanced Raman spectroscopy is investigated as a precise method for the analysis of biological samples. Using the nite dierence time domain, simulation is carried out to design the required structures for the study of these samples. At rst, by comparing dierent tip-enhanced Raman spectroscopy structures and considering the material, dimensions, and other parameters in the simulation, the ideal structure is introduced from a physical point of view and considering the electric eld enhancement. In the following, taking into account the eect of environmental and chemical reactions during testing on biological samples, biocompatible materials are used as substrate coating in the simulation. The impact of using these materials is investigated in comparison with the previous conditions. After performing the simulations, we concluded that Au, Cu, and Ag have the highest electric eld enhancement, i.e., the presence of Au next to Cu and Au and Cu next to Ag leads to the enhancement of their electric eld. In the following, we found that the material and thickness of the layer under the coating in the substrate and tip greatly in uence the enhancement. Finally, we used ve biocompatible materials as a coating when using the Au tip and substrate, which creates the greatest electric eld enhancement. We saw that the use of biocompatible materials signi cantly reduces the enhancement, and the eects of the use of these ve materials do not dier so much. In summary, using a 1 nm layer of biocompatible coating creates a much more favorable eect on enhancement than larger thicknesses.

Polymer dielectrics with high energy density and low dielectric loss are highly desired due to the rapid development of electric devices. Among known polymers, poly(vinylidene fluoride-ter-trifluoroethylene-ter-chlorofluoroethylene) P(VDF-TrFE-CFE) is one of the promising materials for energy storage capacitor applications because of its high dielectric constant. Nevertheless, it suffers from high dielectric loss especially at the high electric field, which suppresses its breakdown strength and energy storage density. Herein, sandwiched structure dielectric films were fabricated by employing polymethyl methacrylate (PMMA) as the outer layer and P(VDF-TrFE-CFE) as the central layer. By modulating the thickness of the central layer, an enhanced discharged energy density of 7.03 J/cm3 is achieved at a high electric field of 480 MV/m, which is 132% more than that of P(VDF-TrFE-CFE) at its maximum electric field 300 MV/m. Meanwhile, this sandwiched structure film also retains a high discharge efficiency of 78% at 480 MV/m, which is never been seen in polyvinylidene fluoride-based polymers. Results show that PMMA acts as charge barrier and simultaneously enhance the breakdown strength and suppress the dielectric loss of P(VDF-TrFE-CFE).

Piper cubeba is an important plant commonly known as cubeb or Java pepper, and it is cultivated for its fruit and essential oils, largely used to treat various diseases. Up to today, there was no scientific report on wound healing activity. Thus, this study was initiated to evaluate for the first time the antimicrobial activity and wound healing potential of a new chemotype from Piper cubeba essential oil (PCEO) from fruits. Thirteen microbial strains have been selected to investigate the antimicrobial potential of PCEO. For the evaluation of the wound healing potential, sixteen rats were excised on the dorsal back and divided into four groups. The effect of PCEO on the malondialdehyde (MDA) and superoxide dismutase (SOD) activities in the healed wound area of rats and the biochemical parameters and skin histological analysis were also assessed. Results: Data showed that PCEO exhibited a powerful antimicrobial potential especially against Listeria monocytogenes and Staphylococcus aureus. In addition, the topical application of PCEO cream appears to increase the SOD level, wound healing and contraction but reduced the MDA amount suggesting an impressive and a rapid cutaneous healing power. Additionally, histopathological analysis of the granulation tissue revealed that the derma is properly restored and arranged after treatment with PCEO. The docking analysis of PCEO constituents against S. aureus tyrosyl-tRNA synthetase enzyme showed binding energies values in the range of −7.2 to −4.8 kcal/mol. In conclusion, the topic use of PCEO healing cream showed significant effect in accelerating the healing process, which may be attributed to the synergetic effect of antioxidant and antimicrobial properties of PCEO volatile constituents, making it a relevant therapeutic agent for the management of wounds and therefore confirming the popular traditional uses of this plant.

The defects and subsurface damages induced by crystal growth and micro/nano-machining have a significant impact on the functional performance of machined products. Raman spectroscopy is an efficient, powerful, and non-destructive testing method to characterize these defects and subsurface damages. This paper aims to review the fundamentals and applications of Raman spectroscopy on the characterization of defects and subsurface damages in micro/nano-machining. Firstly, the principle and several critical parameters (such as penetration depth, laser spot size, and so on) involved in the Raman characterization are introduced. Then, the mechanism of Raman spectroscopy for detection of defects and subsurface damages is discussed. The Raman spectroscopy characterization of semiconductor materials’ stacking faults, phase transformation, and residual stress in micro/nano-machining is discussed in detail. Identification and characterization of phase transformation and stacking faults for Si and SiC is feasible using the information of new Raman bands. Based on the Raman band position shift and Raman intensity ratio, Raman spectroscopy can be used to quantitatively calculate the residual stress and the thickness of the subsurface damage layer of semiconductor materials. The Tip-Enhanced Raman Spectroscopy (TERS) technique is helpful to dramatically enhance the Raman scattering signal at weak damages and it is considered as a promising research field.

This article focuses on a Persian legend derived from Abol Qasem Ferdowsi’s Shahnameh (The Book of Kings) with a rather peculiar antagonist: a dragoness whose most significant expression is laughter. By revising what Islam and Zoroastrian ism (both present as structuring constructs in this legend) teach about laughter, we will try to under stand why such a humane expression is attributed to a monster. Since the monster in question is a female creature, we will also explore a gendered perspective to establish a link between dragons and laughter. Finally, by means of symbolic and cultural hermeneutics, we will reflect on the only way the dragoness can be destroyed: a mirror. El artículo se centra en una leyenda persa derivada del Shahnamé (El libro de los reyes) de Abol Qasem Ferdousí en la que aparece una antagonista bastante peculiar: una dragona cuya expresión más significativa es la risa. Mediante la revisión de lo que el islam y el zoroastrismo (am bos presentes como constructos estructurantes en esta leyenda) nos enseñan sobre la risa, se intenta comprender por qué se le atribuye una expresión tan humana a un monstruo. Como el monstruo en cuestión es una criatura femenina, también se explora una perspectiva de género para establecer un vínculo entre los dragones y la risa. Por último, se recurre a la hermenéutica simbólica y cultural para reflexionar sobre la única forma de destruir a la dragona: un espejo.

Transition metal dichalcogenide (TMDs) heterostructure, particularly the lateral heterostructure of two different TMDs, is gaining attention as ultrathin photonic devices based on the charge transfer (CT) excitons generated at the junction. However, the characteristics of the interface of the lateral heterostructure, determining the electronic band structure and alignment at the heterojunction region, have rarely been studied due to the limited spatial resolution of nondestructive analysis systems. In this study, we investigated the confined phonons resulting from the phonon-disorder scattering process involving multiple disorders at the lateral heterostructure interface of MoS –WS to prove the consequences of disorder-mediated deformation in the band structure. Moreover, we directly observed variations in the metal composition of the multi-disordered nanoscale alloy Mo , consisting of atomic vacancies, crystal edges, and distinct nanocrystallites. Our findings through tip-enhanced Raman spectroscopy (TERS) imply that a tens of nanometer area of continuous TMDs alloy forms the multi-disordered interface of the lateral heterostructure. The results of this study could present the way for the evaluation of the TMDs lateral heterostructure for excitonic applications.