Ripening process in exocarps of scarlet eggplant () and banana ( spp.) investigated by Raman spectroscopy.

In this work, we used Raman spectroscopy to identify compounds present at different maturation stages of the exocarp of scarlet eggplant and two banana cultivars, 'prata' and 'nanica'. Raman spectral analyses of both fruits showed bands attributed to phenolic acids, flavonoids, carotenoids, and fatty acids. During the scarlet eggplant's maturation process, Raman spectral profile changes are mainly observed in the carotenoid content rather than flavonoids.

Hematite colour revisited: Particle size and electronic transitions.

Hematite has been used as a pigment since ancient times, due to its natural abundance and colour that ranges from vivid red to purple. Caput mortuum is a purple α-FeO whose colour has been ascribed as originating from particle size. In this work, submicrometric synthetic, natural and commercial hematites were investigated by diffuse reflectance spectroscopy (DRS), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and Raman microscopy aiming to clarify the origin of the purple colour.

Scytonin in gypsum endolithic colonisation: First Raman spectroscopic detection of a new spectral biosignature for terrestrial astrobiological analogues and for exobiological mission database extension.

Microbial colonisations of gypsum from Eastern Poland (Badenian, Middle Miocene age) were investigated by Raman microspectrometry with a rarely used excitation 445 nm excitation. Zones of microbial colonisation in selenitic gypsum endolithic outcrops comprise algae and cyanobacteria, which commonly contain the photosynthetic and protective pigments carotenoids, scytonemin and gloeocapsin. Diagnostic bands differing from those of scytonemin have been identified in black colonies in gypsum outcrops at Chotel Czierwony (Poland).

Characterization by Raman and infrared spectroscopy and fluorescence microscopy of human hair treated with cosmetic products.

Analytical studies on hair structures have evolved significantly over the years and vibrational spectroscopic techniques, such as Raman and infrared, have been increasingly used for such purposes. Nowadays, there is a need to understand more and more about the action of cosmetics on the hair fiber, so this work aims to analyze the permeation of cosmetic treatments into the hair. For the molecular structural characterization, Raman and infrared spectroscopy techniques were used, being verified the efficiency in the analysis of hair samples, demonstrating the internal characteristics of the fiber and the permeation of different cosmetics.

Fe-Rich Fossil Vents as Mars Analog Samples: Identification of Extinct Chimneys in Miocene Marine Sediments Using Raman Spectroscopy, X-Ray Diffraction, and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy.

On Earth, the circulation of Fe-rich fluids in hydrothermal environments leads to characteristic iron mineral deposits, reflecting the pH and redox chemical conditions of the hydrothermal system, and is often associated with chemotroph microorganisms capable of deriving energy from chemical gradients. On Mars, iron-rich hydrothermal sites are considered to be potentially important astrobiological targets for searching evidence of life during exploration missions, such as the Mars 2020 and the ExoMars 2022 missions. In this study, an extinct hydrothermal chimney from the Jaroso hydrothermal system (SE Spain), considered an interesting geodynamic and mineralogical terrestrial analog for Mars, was analyzed using Raman spectroscopy, X-ray diffraction, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy.

English delftware (c. 1770) from Bristol, Lancaster and Liverpool: A composition study using Raman spectroscopy and electron microscopy.

Nine decorated lead-tin glazed earthenwares, colloquially termed 'delftware', produced in c. 1770 in Bristol, Lancaster and Liverpool, England, have been analysed non-invasively by Raman spectroscopy and electron microscopy. The body paste used to manufacture these west coast wares was attained by the blending of highly dolomitic [CaMg(CO)] "blue" clay sourced from Carrickfergus, County Antrim, Ireland, with locally sourced clays.

New insights on plasters, pigments and binder in mural paintings of the Setka tomb (QH 110), Elephantine, Aswan, Upper Egypt.

Mural paintings within the tomb of Setka, Qubbet el-Hawa, in Aswan, Upper Egypt, were investigated using a multi-disciplinary analytical approach (Stereomicroscopy, SEM-EXD and FT-IR spectroscopy). The walls of the tomb were hewn from fragile sandstone and covered by a clay plaster, overlaid by two layers of white gypsum plaster. SEM micrographs were indicative of the penetration of fungal mycelium within the pores of the gypsum plaster, forming white encrustations due to the re-precipitation of gypsum.

Development of a Surface-Enhanced Raman Spectroscopic Methodology to Detect Immobilized Organic Materials in Biogeological Contexts.

The likelihood of finding intact cellular structures on the surface or in the near subsurface of the martian regolith is slim, due in part to the intense bombardment of the surface by ionizing radiation from outer space. Given that this radiation is predicted to be so intense that it would render a living cell inactive within minutes, it is logical to search for evidence of microbial life by looking for molecules produced by the breakdown of cellular matter. This "pool" of molecules, known as biomarkers, consists of a range of species with various functionalities that make them likely to interact with minerals in the martian regolith.

The Diversity of Linear Conjugated Polyenes and Colours in Nature: Raman Spectroscopy as a Diagnostic Tool.

This review is centered on the linear conjugated polyenes, which encompasses chromatic biomolecules, such as carotenoids, polyunsaturated aldehydes and polyolefinic fatty acids. The linear extension of the conjugated double bonds in these molecules is the main feature that determines the spectroscopic properties as light-absorbing. These classes of compounds are responsible for the yellow, orange, red and purple colors which are observed in their parent flora and fauna in nature.

Histology and Raman spectroscopy of limed human remains from the Rwandan Genocide.

The Murambi Genocide Memorial Centre is one of the major centres in Rwanda that commemorate the 1994 Rwandan genocide. Seventeen months after the genocide, about 1000 excavated human remains were put on display in Murambi Technical School. Repeated efforts were made to desiccate the human remains with lime for educational reasons.

Raman spectroscopy and electronic microscopy structural studies of Caucasian and Afro human hair.

Human hair fibre is subjected to various structural modifications due to the application of chemicals such as dyes, shampoos and bleaches and/or physical procedures such as heating, and often more than one procedure is performed on the same hair. The present work aims to analyze the changes incurred in hair samples of two ethnic groups, namely Caucasian and Afro, before and after different treatments such as thermal, bleaching and straightening. In addition to observing the damage caused by each treatment separately, the study of samples that received all three treatments was carried out.

Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover.

The second ExoMars mission will be launched in 2020 to target an ancient location interpreted to have strong potential for past habitability and for preserving physical and chemical biosignatures (as well as abiotic/prebiotic organics). The mission will deliver a lander with instruments for atmospheric and geophysical investigations and a rover tasked with searching for signs of extinct life. The ExoMars rover will be equipped with a drill to collect material from outcrops and at depth down to 2 m.

Accurate Differentiation of Carotenoid Pigments Using Flight Representative Raman Spectrometers.

Raman spectrometers will be utilized on two Mars rover missions, ExoMars and Mars 2020, in the near future, to search for evidence of life and habitable geological niches on Mars. Carotenoid pigments are recognized target biomarkers, and as they are highly active in Raman spectroscopy, they can be readily used to characterize the capabilities of space representative instrumentation. As part of the preparatory work being performed for the ExoMars mission, a gypsum crust colonized by microorganisms was interrogated with commercial portable Raman instruments and a flight representative Raman laser spectrometer.

Raman spectroscopic analysis of the effect of the lichenicolous fungus on its lichen host.

Lichenicolous (lichen-dwelling) fungi have been extensively researched taxonomically over many years, and phylogenetically in recent years, but the biology of the relationship between the invading fungus and the lichen host has received limited attention, as has the effects on the chemistry of the host, being difficult to examine in situ Raman spectroscopy is an established method for the characterization of chemicals in situ, and this technique is applied to a lichenicolous fungus here for the first time. occurs in the apothecia of , producing conidia at the hymenium surface. Raman spectroscopy of apothecial sections revealed that parietin and carotenoids were destroyed in infected apothecia.

A definitive analytical spectroscopic study of Indian yellow, an ancient pigment used for dating purposes.

The Raman spectrum of tartrazine has been mistakenly reported as being that of Indian yellow in the literature, which has serious consequences for the identification of this pigment in art works regarding their authentication. Unlike tartrazine, Indian yellow (a natural mixture of the magnesium and calcium salts of euxanthic acid) exhibits in its Raman spectrum a strong fluorescent background when visible excitation is used, however, excitation in the near infrared (1064nm) permitted the observation of the Raman bands from the raw pigment with the main features placed at 1346, 1368, 1425, 1441 and 1626cm. Indian yellow identification was assured by H and C Nuclear Magnetic Resonance characterization and the complete assignment of the proton and carbon resonances was accomplished using heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear overhauser effect spectroscopy (NOESY) and H-H correlation spectroscopy (COSY).

Analyzing and Interpreting Lime Burials from the Spanish Civil War (1936-1939): A Case Study from La Carcavilla Cemetery.

Over 500 victims of the Spanish Civil War (1936-1939) were buried in the cemetery of La Carcavilla (Palencia, Spain). White material, observed in several burials, was analyzed with Raman spectroscopy and powder XRD, and confirmed to be lime. Archaeological findings at La Carcavilla's cemetery show that the application of lime was used in an organized way, mostly associated with coffinless interments of victims of Francoist repression.

The preservation of archaeological brain remains in a human skeleton.

The identification of biomass within the cranial cavity of a waterlogged human skeleton inside a fish-tailed wooden coffin from a nineteenth century burial has been confirmed as brain tissue. A comparison is made between the Raman spectra obtained in the current study with those from an Iron Age brain found in an isolated cranium dating from about 500 years BCE, the only other Raman spectroscopy study made of human brain recovered from waterlogged, archaeological excavations. The spectra give some surprisingly detailed information about the state of preservation of brain tissue in both burials, especially when it is realized that, unlike preserved bog bodies, no other soft tissue has survived.

Raman spectroscopic analysis of archaeological specimens from the wreck of HMS Swift, 1770.

Specimens from underwater archaeological excavations have rarely been analysed by Raman spectroscopy probably due to the problems associated with the presence of water and the use of alternative techniques. The discovery of the remains of the Royal Navy warship HMS Swift off the coast of Patagonia, South America, which was wrecked in 1770 while undertaking a survey from its base in the Falkland/Malvinas Islands, has afforded the opportunity for a first-pass Raman spectroscopic study of the contents of several glass jars from a wooden chest, some of which had suffered deterioration of their contents owing to leakage through their stoppers. From the Raman spectroscopic data, it was possible to identify organic compounds such as anthraquinone and copal resin, which were empirically used as materia medica in the eighteenth century to treat shipboard diseases; it seems very likely, therefore, that the wooden chest belonged to the barber-surgeon on the ship.

Raman spectroscopic analysis of a 'noli me tangere' painting.

The discovery of an oil painting in seriously damaged condition with an important historical and a heterodox detail with possible origins in the late fifteenth century has afforded the opportunity for Raman microscopic analysis prior to its restoration being undertaken. The painting depicts a risen Christ following His crucifixion in a 'noli me tangere' pose with three women in an Italian terrace garden with a stone balustrade overlooking a rural landscape and an undoubted view of late-medieval Florence. The picture has suffered much abuse and is in very poor condition, which is possibly attributable to its controversial portrayal of a polydactylic Christ with six toes on His right foot.

Raman spectroscopic analysis of an important Visigothic historiated manuscript.

Raman spectroscopy has been used to study fragments of early Visigothic historiated manuscripts from the important mediaeval library at Santo Domingo de Silos which were a part of a Beato dating from the tenth to the mid-eleventh centuries. These fragments are from some of the oldest manuscripts in the scriptorium of the monastery. In this study, a comparison is made between the pigments and inks used on these manuscripts and those used in a previous study of the unique Visigothic Beato de Valcavado in Santa Cruz, Valladolid, completed in the year 970, which is noted for its quality of execution as well as its content and is remarkable eschatologically in being identifiable as the complete work of only a single scribe.

The detection of flunitrazepam in beverages using portable Raman spectroscopy.

Portable Raman spectroscopy has been used for the detection of the date-rape drug flunitrazepam in spiked beverages that may be involved in cases of drug-facilitated sexual assault. Solutions of flunitrazepam with different concentrations were prepared in water and for each beverage type. Although some bands attributable to the beverage matrix are present, they did not interfere with the identification of the drug.

Raman spectroscopic study of the Chromobacterium violaceum pigment violacein using multiwavelength excitation and DFT calculations.

Violacein is a bisindole pigment occurring as a biosynthetic product of Chromobacterium violaceum and Janthinobacterium lividum. It has some structural similarities to the cyanobacterial UV-protective pigment scytonemin, which has been the subject of comprehensive spectroscopic and structural studies. A detailed experimental Raman spectroscopic study with visible and near-infrared excitation of violacein produced by C.

Selection of Portable Spectrometers for Planetary Exploration: A Comparison of 532 nm and 785 nm Raman Spectroscopy of Reduced Carbon in Archean Cherts.

Knowledge and understanding of the martian environment has advanced greatly over the past two decades, beginning with NASA's return to the surface of Mars with the Pathfinder mission and its rover Sojourner in 1997 and continuing today with data being returned by the Curiosity rover. Reduced carbon, however, is yet to be detected on the martian surface, despite its abundance in meteorites originating from the planet. If carbon is detected on Mars, it could be a remnant of extinct life, although an abiotic source is much more likely.

Study of carotenoids in cyanobacteria by Raman spectroscopy.

Cyanobacteria have established dominant aquatic populations around the world, generally in aggressive environments and under severe stress conditions, e.g., intense solar radiation.