Minute Samples Research Articles

The application of vibrational spectroscopy in forensic analysis of biological evidence.

Vibrational spectroscopy is a powerful analytical domain, within which Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy stand as exemplars, offering high chemical specificity and sensitivity. These methodologies have been instrumental in the characterization of chemical compounds for an extensive period. They are particularly adept at the identification and analysis of minute sample quantities. Both FTIR and Raman spectroscopy are proficient in elucidating small liquid samples and detecting nuanced molecular alterations. The application of chemometrics further augments their analytical prowess. Currently, these techniques are in the research phase within forensic medicine and have yet to be broadly implemented in examination and identification processes. Nonetheless, studies have indicated that a combined classification model utilizing FTIR and Raman spectroscopy yields exceptional results for the identification of biological fluid-related information and the determination of causes of death. The objective of this review is to delineate the current research trajectory and potential applications of these two vibrational spectroscopic techniques in the detection of body fluids and the ascertainment of causes of death within the context of forensic medicine.

Influence of Antenatal Education on Birth Outcomes: A Systematic Review Focusing on Primiparous Women.

The primary objective of prenatal education programs is to furnish expectant mothers with the necessary knowledge for childbirth and early parenting. Despite the extensive implementation of these programs, the efficacy of these interventions remains unclear. This systematic review endeavored to consolidate the extant evidence pertaining to the effects of prenatal education on birth outcomes and experiences. Fourteen studies, comprising various study designs executed across diverse countries, were incorporated in this review. The outcomes assessed in these studies encompassed fear and anxiety, pain, delivery mode, interventions, postpartum depression, and self-efficacy. Additionally, the risk of bias and study limitations were also summarized. The results manifested that prenatal education was effective in diminishing the fear and anxiety associated with childbirth and enhancing self-efficacy in the majority of the studies. Moreover, several studies found that engaging in prenatal education augmented the preference for unmedicated vaginal birth. However, the effects of prenatal education on postpartum outcomes were less consistent. The primary constraints of the included studies were their minute sample sizes and brief follow-up periods. Nonetheless, the existing evidence proposes that prenatal education is beneficial for first-time mothers in terms of alleviating anxiety and augmenting agency during delivery. Prenatal education can equip pregnant individuals with the necessary knowledge and skills to navigate the perinatal period successfully. Further research is requisite to identify the optimal practices for diverse populations on a global scale.

Nanoscale flow cytometry-based quantification of blood-based extracellular vesicle biomarkers distinguishes MCI and Alzheimer's disease.

Accurate testing for Alzheimer's disease (AD) represents a crucial step for therapeutic advancement. Currently, tests are expensive and require invasive sampling or radiation exposure. We developed a nanoscale flow cytometry (nFC)-based assay of extracellular vesicles (EVs) to screen biomarkers in plasma from mild cognitive impairment (MCI), AD, or controls. Circulating amyloid beta (Aβ), tau, phosphorylated tau (p-tau)181, p-tau231, p-tau217, p-tauS235, ubiquitin, and lysosomal-associated membrane protein 1-positive EVs distinguished AD samples. p-tau181, p-tau217, p-tauS235, and ubiquitin-positive EVs distinguished MCI samples. The most sensitive marker for AD distinction was p-tau231, with an area under the receiver operating characteristic curve (AUC) of 0.96 (sensitivity 0.95/specificity 1.0) improving to an AUC of 0.989 when combined with p-tauS235. This nFC-based assay accurately distinguishes MCI and AD plasma without EV isolation, offering a rapid approach requiring minute sample volumes. Incorporating nFC-based measurements in larger populations and comparison to "gold standard" biomarkers is an exciting next step for developing AD diagnostic tools. Extracellular vesicles represent promising biomarkers of Alzheimer's disease (AD) that can be measured in the peripheral circulation. This study demonstrates the utility of nanoscale flow cytometry for the measurement of circulating extracellular vesicles (EVs) in AD blood samples. Multiple markers including amyloid beta, tau, phosphorylated tau (p-tau)181, p-tau231, p-tau217, and p-tauS235 accurately distinguished AD samples from healthy controls. Future studies should expand blood and cerebrospinal fluid-based EV biomarker development using nanoflow cytometry approaches.

Unraveling the mummy's shroud: A multi-analytical study of a rare painted textile from Roman Egypt

This article describes a multi-analytical technical study of a rare painted shroud still wrapped around a female Egyptian mummy (MCABo EG 1974) in the collection of the Museo Civico Archeologico of Bologna, Italy. Long stored in the museum's warehouses, these mummified human remains were recently rediscovered within the Bologna Mummy Project (BOmp), an interdisciplinary endeavor promoted by the Museo Civico Archeologico and the Institute for Mummy Studies of Eurac Research, Bolzano, Italy. Dating to the Roman period (1st-2nd century C.E.), as confirmed by radiocarbon dating, this mummy displays a unique series of technical features, including the exceptional finding of a colorful painted shroud still preserved in its original location around the wrapped body, to which it is secured with textile straps and resin. In this context, scientific analysis aimed to deepen our current knowledge of the artistic practices of Roman Egypt through an in-depth study of the painting technique, context of production, and possible provenance of the mummy, while promoting a science-informed, enhanced approach to the preservation of the mummified human remains. This research relied on an integrated analytical protocol based on the combined use of imaging and mapping techniques, non-invasive point analysis, and micro-invasive investigation of minute samples, each carried out at the different partnering institutions. Computed tomography (CT) highlighted varying radio-densities for some of the flesh tones and red decorations. Visible photography and multiband imaging provided information on the nature and distribution of various materials on the surface. Fiber optics reflectance spectroscopy (FORS), X-ray fluorescence (XRF) spectroscopy, and Raman spectroscopy contributed to the characterization of the shroud's color palette along with optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), as well as high-performance liquid chromatography coupled with diode-array detection and mass spectrometry (HPLC/DAD and HPLC/MS). Materials detected include a limited number of mineral pigments and plant-derived dyes such as red lead, red ocher, madder, an unknown yellow dye, Egyptian blue and green, and a carbon-based black. Through access to MOLAB equipment and expertise, macro-XRF (MA-XRF), as well as combined X-ray diffraction (XRD) spot analysis and mapping, enhanced pigment identification. A combination of transmission Fourier-transform infrared (FTIR) spectroscopy with gas chromatography / mass spectrometry (GC/MS) was used to identify the paint binders and any additional organic substances possibly involved in embalming practices and ritual traditions, including animal fat, plant lipid, Pinaceae resin, gum, and beeswax. Mineralogical data gathered by XRD on surface deposits and soil residues collected from within the shroud's inner folds was crucial to put forward hypotheses, in support of the stylistic study of the shroud, concerning a possible provenance from Upper Egypt, most likely West Thebes. Both the shroud and inner bandages were found to be made with linen using OM. After undergoing scientific analysis and conservation treatment, the mummy was displayed in the “Mummies. Unwrapping the past” exhibition and was featured at the 10th World Congress on Mummy Studies, both held in Bolzano in the fall of 2022.

Advances in DNA Extraction Techniques: A Comprehensive Review of Methods and Applications

The extraction of DNA is a fundamental process in molecular biology, underpinning a wide range of applications from genetic research to forensic science and medical diagnostics. This review aims to explore the latest advancements in DNA extraction techniques, highlighting their principles, applications, and suitability for various types of biological samples. Traditional DNA extraction methods, such as phenol-chloroform and ethanol precipitation, have served as the backbone of DNA isolation for decades. However, these techniques often involve hazardous chemicals and can be time-consuming. Recent advancements have focused on developing safer, faster, and more efficient methods, with a focus on automation and scalability. Innovations such as magnetic bead-based extraction, silica column purification, and specialized kits have greatly simplified the process, allowing for high-throughput applications in clinical and research settings. In addition to these technical improvements, new approaches have emerged to address specific challenges, such as extracting DNA from degraded or trace samples, as seen in forensic investigations, or isolating cell-free DNA for non-invasive prenatal testing and cancer diagnostics. Moreover, microfluidic devices and lab-on-a-chip technologies are transforming the landscape by enabling DNA extraction from minute samples with minimal reagent consumption. This review discusses the principles underlying these advanced techniques, their benefits and limitations, and the specific contexts in which they excel. It also considers future trends, including further automation, integration with sequencing platforms, and the potential for point-of-care applications. By examining the current state of DNA extraction technology, this review aims to provide researchers and practitioners with a comprehensive guide to the best methods for their specific needs.

Effects of corona discharge plasma pretreatment on the drying kinetics and quality attributes of lily (Lilium davidii var. unicolor) bulbs

The objective of this study was to examine the impact of corona discharge plasma (CDP) treatments of different durations (1, 3, 5, and 10 min) on the drying kinetics and quality attributes of lilies, including color, enzyme activities, total phenols content (TPC), and antioxidant activity. The microstructure of lilies under different CDP conditions were also investigated. As a result, all CDP treatments enhanced the drying rate relative to untreated lilies, and the shortest drying time of 7 h was obtained at CDP-3 minute samples. CDP treatment led to a higher retention in the TPC of dried lilies. Microstructural analysis revealed the formation of irregular micropores on the surface of the lilies after CDP treatment, which was closely associated with the accelerated drying rate and improved bioactive substances of the dried product. In conclusion, CDP has emerged as a novel and beneficial pretreatment technique that accelerates the drying process and enhances the nutritional qualities of dried lilies.

Impact of Extraction Methods and Transportation Conditions on Lipid Profiles of Bovine Oocytes.

Lipids play numerous pivotal physiological roles in mammalian reproduction, being indispensable for oocyte competence acquisition and post-fertilization embryonic development. Profiling lipids in minute samples, such as oocytes, presents challenges but has been accomplished through mass spectrometry technologies like Multiple Reaction Monitoring (MRM) profiling. With the dual objectives of simplifying workflow and examining the influence of preanalytical conditions, we assessed whether transportation at room temperature affects the lipid profile of bovine oocytes. To this end, samples were prepared using either monophasic (methanol only) or biphasic liquid extraction protocols (Bligh & Dyer method) and transported either on dry ice or at room temperature inside sealed-vacuum packages to prevent lipid oxidation. Subsequently, employing a comprehensive method, we screened a list of 316 MRMs from 10 different lipid subclasses in oocyte lipid extracts. Principal Component Analysis (PCA) revealed similar lipid profiles concerning temperature during transportation, whereas clear differentiation among samples was observed based on the lipid extraction method. Univariate analysis indicated that the one-phase methanol extraction resulted in higher relative abundances of phospholipids, except for phosphatidylserines. Conversely, the Bligh & Dyer extraction favored the detection of neutral intracellular lipids (triacylglycerols, free fatty acids, cholesteryl esters, and acyl-carnitines). Consequently, lipid recovery was directly correlated with the polarity of lipid class and the extraction method. Regarding transportation temperature, phosphatidylethanolamine, triacylglycerol, and free fatty acids exhibited lower abundances when samples were transported at room temperature. Based on multivariate and univariate analyses, we conclude that if samples undergo the same lipid extraction protocol and are transported in the same batch at room temperature inside vacuum-sealed bags, it is feasible to analyze lipid extracts of bovine oocytes and still obtain informative lipid profiling results.

Development and clinical validation of a dual ddPCR assay for detecting carbapenem-resistant Acinetobacter baumannii in bloodstream infections.

Acinetobacter baumannii (A. baumannii, AB) represents a major species of Gram-negative bacteria involved in bloodstream infections (BSIs) and shows a high capability of developing antibiotic resistance. Especially, carbapenem-resistant Acinetobacter baumannii (CRAB) becomes more and more prevalent in BSIs. Hence, a rapid and sensitive CRAB detection method is of urgent need to reduce the morbidity and mortality due to CRAB-associated BSIs. A dual droplet digital PCR (ddPCR) reaction system was designed for detecting the antibiotic resistance gene OXA-23 and AB-specific gene gltA. Then, the specificity of the primers and probes, limit of detection (LOD), linear range, and accuracy of the assay were evaluated. Furthermore, the established assay approach was validated on 37 clinical isolates and compared with blood culture and drug sensitivity tests. The dual ddPCR method established in this study demonstrated strong primer and probe specificity, distinguishing CRAB among 21 common clinical pathogens. The method showed excellent precision (3 × 10-4 ng/μL, CV < 25%) and linearity (OXA-23: y = 1.4558x + 4.0981, R2 = 0.9976; gltA: y = 1.2716x + 3.6092, R2 = 0.9949). While the dual qPCR LOD is 3 × 10-3 ng/μL, the dual ddPCR's LOD stands at 3 × 10-4 ng/μL, indicating a higher sensitivity in the latter. When applied to detect 35 patients with BSIs of AB, the results were consistent with clinical blood culture identification and drug sensitivity tests. The dual ddPCR detection method for OXA-23 and gltA developed in this study exhibits good specificity, excellent linearity, and a higher LOD than qPCR. It demonstrates reproducibility even for minute samples, making it suitable for rapid diagnosis and precision treatment of CRAB in BSIs.

Integrated Investigations of Painting Materials in the Sasanian City of Ardaxšīr Khwarrah, near Firuzabad (Southern Iran)

Ancient Ardaxšīr Khwarrah, today known as Shahr-e Gur, situated near the modern town of Firuzabad in Fars, Iran, holds historical significance as the inaugural capital city of the Sasanian Empire. During archaeological excavations conducted in 2005 by an Iranian–German team directed by Mas‘oud Azarnoush and Dietrich Huff, a mud-brick complex was uncovered, revealing a remarkably well-preserved stretch of wall painting and a polychrome painted floor. The discovery prompted the hypothesis of a potential funerary context dating back to the Sasanian period. Both the wall painting and painted floor have suffered extensive deterioration attributed to the environmental conditions of the archaeological site, which was inscribed on the UNESCO World Heritage List in 2020. To address the urgent need for preservation and further understanding of the site’s artistic and structural elements, an emergency diagnostic project was initiated. Non-invasive investigations were carried out on the wall and floor by optical digital microscopy and portable energy-dispersive X-ray fluorescence. Additionally, representative minute samples underwent analysis through various techniques, including micro-X-ray fluorescence, polarised light microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, micro-Raman spectroscopy, micro-Fourier Transform Infrared Spectroscopy, gas chromatography-mass spectrometry and pyrolysis coupled with gas chromatography-mass spectrometry. The palette of the floor and mural paintings were identified to contain red and yellow ochres, lead-based pigments, carbon black and bone white. The unexpected presence of Egyptian blue mixed with green earth was recognised in the green hues of the wall painting. The detection of protein material in both the wall painting and polychrome floor indicates the use of “a secco” technique, thereby shedding light on the artistic practices employed in Ardaxšīr Khwarrah.

Wavelength-tunable ultrafast two arm fiber laser system for transient interferometric scattering microscopy on nanoscopic objects

Ultrafast time-resolved microscopy of single nano-objects is particularly challenging because of minute sample volumes and correspondingly small signal levels together with the possibility of photobleaching. We present a compact pulsed two arm fiber laser-based system suited for highly sensitive transient interferometric scattering (TiSCAT) microscopy of nanomaterials. A continuously tunable probe arm is used for spectrally resolved detection of the transient sample response in the range between 810 and 960 nm upon pulsed excitation at 780 nm by the pump arm. Coupled to a scanning confocal microscope with high numerical aperture objective, the system provides spectral maps with sub-300 nm spatial and 300 fs temporal resolution. We tested the platform using monolayer MoSe2 and individual (6,4) single-walled carbon nanotubes as model samples. Confocal microscopy images recorded for an exfoliated monolayer MoSe2 reveal spatially varying excited state decay, highlighting the need for local probing. Spectrally resolved TiSCAT measurements on individual (6,4) single-walled carbon nanotubes show that the transient response is dominated by ground-state bleaching with picosecond recovery times. The obtained data illustrate the excellent noise properties and stability of the newly developed laser system, which allow for nearly shot-noise limited TiSCAT detection at the low probe fluences required for avoiding photodegradation of sensitive nanomaterials.

Inkjet-Based Intracellular Delivery System that Effectively Utilizes Cell-Penetrating Peptides for Cytosolic Introduction of Biomacromolecules through the Cell Membrane.

In the drug delivery system, the cytosolic delivery of biofunctional molecules such as enzymes and genes must achieve sophisticated activities in cells, and microinjection and electroporation systems are typically used as experimental techniques. These methods are highly reliable, and they have high intracellular transduction efficacy. However, a high degree of proficiency is necessary, and induced cytotoxicity is considered as a technical problem. In this research, a new intracellular introduction technology was developed through the cell membrane using an inkjet device and cell-penetrating peptides (CPPs). Using the inkjet system, the droplet volume, droplet velocity, and dropping position can be accurately controlled, and minute samples (up to 30 pL/shot) can be carried out by direct administration. In addition, CPPs, which have excellent cell membrane penetration functions, can deliver high-molecular-weight drugs and nanoparticles that are difficult to penetrate through the cell membrane. By using the inkjet system, the CPPs with biofunctional cargo, including peptides, proteins such as antibodies, and exosomes, could be accurately delivered to cells, and efficient cytosolic transduction was confirmed.

Construction of customer-aware grid interactive service system based on neural network model

Abstract Neural network models have advantages in spatial and temporal information processing, which provide new ideas for the construction of customer-aware grid interactive service system. In this paper, firstly, the spatio-temporal fusion deep neural network model based on the attention mechanism is used to extract spatial and temporal information by convolutional neural network and gated recurrent neural network, respectively. The attention mechanism is also introduced to assign weights to various types of features to improve prediction accuracy. Secondly, the global information of the attention mechanism of the channel on the feature map is fully utilized to solve the problem of inadequate extraction of feature information from a single model, and then the grid interactive service system is constructed. The results show that the model proposed in this paper has higher prediction accuracy with root mean square error, coefficient of determination, and prediction accuracy of 0.972, 1.742, and 0.935, respectively. To verify the performance of the cache-based curve service in handling customer-perceived grid interactions, minute samples are created, where the maximum number of minute sample records is 3.5 million. Thus, it is shown that by introducing the attention mechanism can effectively improve the computational efficiency of the model, get better prediction results, and meet the demand for efficient and stable customer-aware interactive service system.

A Facile Graphene Conductive Polymer Paper Based Biosensor for Dopamine, TNF-α, and IL-6 Detection.

Paper-based biosensors are a potential paradigm of sensitivity achieved via microporous spreading/microfluidics, simplicity, and affordability. In this paper, we develop decorated paper with graphene and conductive polymer (herein referred to as graphene conductive polymer paper-based sensor or GCPPS) for sensitive detection of biomolecules. Planetary mixing resulted in uniformly dispersed graphene and conductive polymer ink, which was applied to laser-cut Whatman filter paper substrates. Scanning electron microscopy and Raman spectroscopy showed strong attachment of conductive polymer-functionalized graphene to cellulose fibers. The GCPPS detected dopamine and cytokines, such as tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) in the ranges of 12.5-400 µM, 0.005-50 ng/mL, and 2 pg/mL-2 µg/mL, respectively, using a minute sample volume of 2 µL. The electrodes showed lower detection limits (LODs) of 3.4 µM, 5.97 pg/mL, and 9.55 pg/mL for dopamine, TNF-α, and IL-6 respectively, which are promising for rapid and easy analysis for biomarkers detection. Additionally, these paper-based biosensors were highly selective (no serpin A1 detection with IL-6 antibody) and were able to detect IL-6 antigen in human serum with high sensitivity and hence, the portable, adaptable, point-of-care, quick, minute sample requirement offered by our fabricated biosensor is advantageous to healthcare applications.

A plasmonic gold nano-surface functionalized with the estrogen receptor for fast and highly sensitive detection of nanoplastics

Nanoplastics are a global emerging environmental problem whose effects might pose potential threats to the human’s health. Despite the relevance of the issue, fast, reliable and quantitative in situ analytical approaches to determine nanoplastics are not yet available. The aim of this work was to devise an optical sensor with the goal of direct detecting and quantifying nanoplastics in seawater without sample pre-treatments. To this purpose, a nano-plasmonic biosensor was developed by exploiting an Estrogen Receptor (ER) recognition element grafted onto a polymer-based gold nanograting (GNG) plasmonic platform. The ER-GNG biosensor required just minute sample volumes (2 μL), allowed rapid detection (3 min) and enabled to determine nanoplastics in simulated seawater with a linear dynamic concentrations range of 1–100 ng/mL, thus encompassing the expected environmental loads. The nanostructured grating (GNG) provided remarkable performance enhancements, extending the measurement range across five orders of magnitude, thanks to the both the SPR and the localized SPR phenomena occurring at the GNG chip. At last, the ER-GNG biosensor was tested on real seawater samples collected in the Naples area and the results (∼30 ng/mL) were verified by a conventional approach (filtration and evaporation), confirming the ER-GNG sensor offers a straightforward and highly sensitive method for the direct in-field nanoplastics monitoring.

A spectroscopic liquid biopsy for the earlier detection of multiple cancer types

BackgroundA rapid, low-cost blood test that can be applied to reliably detect multiple different cancer types would be transformational.MethodsIn this large-scale discovery study (n = 2092 patients) we applied the Dxcover® Cancer Liquid Biopsy to examine eight different cancers. The test uses Fourier transform infrared (FTIR) spectroscopy and machine-learning algorithms to detect cancer.ResultsArea under the receiver operating characteristic curve (ROC) values were calculated for eight cancer types versus symptomatic non-cancer controls: brain (0.90), breast (0.76), colorectal (0.91), kidney (0.91), lung (0.91), ovarian (0.86), pancreatic (0.84) and prostate (0.86). We assessed the test performance when all eight cancer types were pooled to classify ‘any cancer’ against non-cancer patients. The cancer versus asymptomatic non-cancer classification detected 64% of Stage I cancers when specificity was 99% (overall sensitivity 57%). When tuned for higher sensitivity, this model identified 99% of Stage I cancers (with specificity 59%).ConclusionsThis spectroscopic blood test can effectively detect early-stage disease and can be fine-tuned to maximise either sensitivity or specificity depending on the requirements from different healthcare systems and cancer diagnostic pathways. This low-cost strategy could facilitate the requisite earlier diagnosis, when cancer treatment can be more effective, or less toxic.Statement of translational relevanceThe earlier diagnosis of cancer is of paramount importance to improve patient survival. Current liquid biopsies are mainly focused on single tumour-derived biomarkers, which limits test sensitivity, especially for early-stage cancers that do not shed enough genetic material. This pan-omic liquid biopsy analyses the full complement of tumour and immune-derived markers present within blood derivatives and could facilitate the earlier detection of multiple cancer types. There is a low barrier to integrating this blood test into existing diagnostic pathways since the technology is rapid, simple to use, only minute sample volumes are required, and sample preparation is minimal. In addition, the spectroscopic liquid biopsy described in this study has the potential to be combined with other orthogonal tests, such as cell-free DNA, which could provide an efficient route to diagnosis. Cancer treatment can be more effective when given earlier, and this low-cost strategy has the potential to improve patient prognosis.

Detecting Isotachophoresis Zones Hidden in Noise Using Signal Processing.

Lowering the limit of detection in chemical or biochemical analysis is key to extending the application scope of sensing schemes. Usually, this is related to an increased instrumentation effort, which in turn precludes many commercial applications. We demonstrate that the signal-to-noise ratio of isotachophoresis-based microfluidic sensing schemes can be substantially increased merely by postprocessing of recorded signals. This becomes possible by exploiting knowledge about the physics of the underlying measurement process. The implementation of our method is based on microfluidic isotachophoresis and fluorescence detection, for which we take advantage of the physics of electrophoretic sample transport and the structure of noise in the imaging process. We demonstrate that by processing only 200 images, the detectable concentration, compared to the detection from a single image, is already lowered by 2 orders of magnitude without any additional instrumentation effort. Furthermore, we show that the signal-to-noise ratio is proportional to the square root of the number of fluorescence images, which leaves room for further lowering of the detection limit. In the future, our results could be relevant for various applications where the detection of minute sample amounts plays a role.

The Initial Molecular Interactions in the Course of Enthalpy Relaxation and Nucleation in Polyethylene Terephthalate (PET) as Monitored by Combined Nanocalorimetry and FTIR Spectroscopy

AbstractFast scanning calorimetry (FSC) and Fourier transform infrared (FTIR) spectroscopy are combined to trace the evolution of the calorimetric properties and of the molecular interactions in a strongly crystallizing polymer, polyethylene terephthalate (PET). The minute sample amount (≈5 ng) required for FSC allows for the realization of cooling rates up to 50 000 K s−1 and to quench the sample into the amorphous state. By subsequent annealing at varying temperatures Ta and times ta enthalpy relaxation, (homogeneous) nucleation and crystallization can be monitored with high precision. Determining the difference IR spectra between a quenched and an annealed sample unravels the development of the intra‐ and inter‐molecular interactions in detail; i) as first response taking place during enthalpy relaxation, the far reaching Coulomb interactions between the polar carbonyl (C ═ O) moieties are active; ii) in contrast, the methylene unit (CH2) and the aromatic ring show a response only, if homogeneous nucleation sets in, while the ester (COC) moiety remains uninfluenced; iii) a hierarchy is observed in of the response of the different molecular moieties; iv) if crystallization comes to play, all molecular units are involved. The results are compared with recently published findings for polyamide 66 demonstrating the high molecular specificity of homogeneous nucleation and crystallization.

NanoSIMS analysis of water content in bridgmanite at the micron scale: An experimental approach to probe water in Earth's deep mantle.

Water, in trace amounts, can greatly alter chemical and physical properties of mantle minerals and exert primary control on Earth's dynamics. Quantifying how water is retained and distributed in Earth's deep interior is essential to our understanding of Earth's origin and evolution. While directly sampling Earth's deep interior remains challenging, the experimental technique using laser-heated diamond anvil cell (LH-DAC) is likely the only method available to synthesize and recover analog specimens throughout Earth's lower mantle conditions. The recovered samples, however, are typically of micron sizes and require high spatial resolution to analyze their water abundance. Here we use nano-scale secondary ion mass spectrometry (NanoSIMS) to characterize water content in bridgmanite, the most abundant mineral in Earth's lower mantle. We have established two working standards of natural orthopyroxene that are likely suitable for calibrating water concentration in bridgmanite, i.e., A119(H2O) = 99 ± 13μg/g (1SD) and A158(H2O) = 293 ± 23μg/g (1SD). We find that matrix effect among orthopyroxene, olivine, and glass is less than 10%, while that between orthopyroxene and clinopyroxene can be up to 20%. Using our calibration, a bridgmanite synthesized by LH-DAC at 33 ± 1GPa and 3,690 ± 120K is measured to contain 1,099 ± 14μg/g water, with partition coefficient of water between bridgmanite and silicate melt ∼0.025, providing the first measurement at such condition. Applying the unique analytical capability of NanoSIMS to minute samples recovered from LH-DAC opens a new window to probe water and other volatiles in Earth's deep mantle.

Polychromy in Ancient Greek Sculpture: New Scientific Research on an Attic Funerary Stele at the Metropolitan Museum of Art

Polychromy in Ancient Greek Sculpture was the subject of the exhibition Chroma: Ancient Greek Sculpture in Color, held at The Metropolitan Museum of Art (The Met), New York, in 2022–2023. On this occasion, a multidisciplinary project involving The Met’s Departments of Greek and Roman Art, Objects Conservation, Imaging, Scientific Research, and colleagues from the Liebieghaus Polychromy Research Project in Frankfurt, Germany, was carried out to study an Attic funerary monument. The color decoration of the sphinx was reconstructed by combining non-invasive and minimally invasive techniques that provided information about surviving and lost pigments, original design, and painting technique. Results of multiband imaging, digital microscopy, and X-ray fluorescence spectroscopy guided the removal of minute samples from selected areas for examination by Raman spectroscopy and scanning electron microscopy, coupled with energy-dispersive X-ray spectroscopy, to shed light on the pigments and paint stratigraphy. The color palette included two varieties of blue, Egyptian blue and azurite, a carbon-based black pigment, two reds, cinnabar and red ocher, and yellow ocher, all painted directly over the marble without a preparation layer. The scientific findings informed the physical reconstruction of the sphinx made by archaeologists from the Liebieghaus Polychromy Research Project, featured in the exhibition.

Online micro solid phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry for trace analysis of endogenous plant hormones in Ulva linza.

Ulva linza (L.) is a species of green algae widely distributed in China. We aimed to establish a sensitive online analytical method for quantification of endogenous phytohormones in fresh minute seaweed samples. The method for quantification of endogenous plant hormones in fresh minute samples was developed based on a homemade online micro solid phase extraction (m-SPE) system coupled with an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) platform. The online m-SPE instrument injected the eluent of m-SPE directly onto the LC separation column, improving the utilization of samples and saving time. The m-SPE column, of which the effective size was 9.6 × 2mm i.d., was filled with 19 mg of C18 (10μm). Under optimized conditions, the limits of detection were 0.002-0.060 ng ml-1 for five plant hormones. The actual sample recoveries of phytohormones were 76.4-103.4% and the coefficients of variance were below 14.1%. The temporal distribution of these endogenous plant hormones of U. linza during different growth periods is described. The proposed online m-SPE method was successfully applied to quantification of endogenous acidic and alkaline plant hormones in U. linza. It provides important information for the further study of the physiological and ecological effects of plant hormones in lower algal species.