Analysis of ethylene glycol (EG) and diethylene glycol (DEG) in oral liquid products using gas chromatography in tandem with Orbitrap spectrometer (GC-Orbitrap).

A selective GC-Orbitrap method has been developed for analysing ethylene glycol (EG) and diethylene glycol (DEG) in four different categories of oral liquid products: Western medicines (WM), traditional medicines (TM), health supplements (HS) and Chinese proprietary medicines (CM). These glycols were chemically ionised to their respective deprotonated ions using methane gas in negative mode and analysed by targeted selected ion monitoring (t-SIM), maintaining a mass error window of ±5 ppm. Internal calibration was performed using matrix-assisted standard solutions ranging from 5 to 100 µg/mL, with 1,4-butanediol-2,2,3,3-D serving as the internal standard (IS).

Hydration characteristics and sustainability of calcium carbide slag-activated full solid waste cementitious materials under high temperature curing.

Using calcium carbide slag (CCS) to replace ordinary portland cement (OPC) as an alkali activator for the preparation of full solid waste cementitious material is a green and low carbon method. This study investigates the influence of 80 °C high-temperature curing on ground granulated blast furnace slag - steel slag based supersulfated cement (GS-SSC) incorporating 0 to 20 wt% CCS. The hydration products and microstructure of GS-SSC were analysed using various microscopic techniques, assess the compressive strength and pH value development, exploring the hydration mechanism of CCS activated GS-SSC.

Advanced vibrational microscopes for life science.

Providing molecular fingerprint information, vibrational spectroscopic imaging opens a new window to decipher the function of biomolecules in living systems. While classic vibrational microscopes based on spontaneous Raman scattering or mid-infrared absorption offer rich insights into sample composition, they have very small cross sections or poor spatial resolution. Nonlinear vibrational microscopy, based on coherent Raman scattering or optical photothermal detection of vibrational absorption, overcomes these barriers and enables high-speed and high-sensitivity imaging of chemical bonds in live cells and tissues.

Reutilization of steel slag (SS) in super sulfate cement (SSC): A comparative study of SS dosage and carbonation treatment on strength development, hydration behavior and sustainable development.

The development of low-carbon cementitious materials is one of the important ways to alleviate the problem of large accumulation of industrial by-products and reduce high energy consumption and high carbon emissions in the cement industry. This study investigated the possibility of using steel slag (SS) as an alkaline activator to prepare super sulfate cement (SSC). The hydration reaction test (hydration heat and pH value) and microscopic characterization (XRD, FTIR, TG and SEM) were used to systematically study the influence mechanism of SS dosage and its carbonation treatment on the macroscopic mechanical properties of the samples.

Analysis of Amine Drugs Dissolved in Methanol by High-Resolution Accurate Mass Gas Chromatography Mass Spectrometry, GC-Orbitrap.

The fragmentation pathways for amines dissolved in methanol (CHOH) or deuterated methanol (CDOD) have been investigated by high-resolution accurate mass gas chromatography mass spectrometry (HRAM-GCMS) or GC-Orbitrap. Primary and secondary amines used in this study were 1,3-dimethylamylamine (1,3-DMAA) and ephedrine hydrochloride (Eph), respectively. For isotopic labeling experiment, 1S, 2R (+) ephedrine-D hydrochloride (D-Eph) was used.

Comprehensive evaluation of low-carbon cementitious materials prepared with industrial by-product calcium carbide residue (CCR) as alkali source.

The preparation of low-carbon cementitious materials through the synergistic coupling of multiple solid wastes has great potential for development, which can improve the problems of resource shortage and environmental pollution. In this paper, a new type of supersulfated cement was developed by using calcium carbide residue (CCR) as an alkaline activator. The effects of CCR content on the mechanical properties and hydration behaviors of the samples under steam curing conditions were discussed.

The Parkinson's disease drug entacapone disrupts gut microbiome homoeostasis via iron sequestration.

Many human-targeted drugs alter the gut microbiome, leading to implications for host health. However, the mechanisms underlying these effects are not well known. Here we combined quantitative microbiome profiling, long-read metagenomics, stable isotope probing and single-cell chemical imaging to investigate the impact of two widely prescribed drugs on the gut microbiome.

Click-free imaging of carbohydrate trafficking in live cells using an azido photothermal probe.

Real-time tracking of intracellular carbohydrates remains challenging. While click chemistry allows bio-orthogonal tagging with fluorescent probes, the reaction permanently alters the target molecule and only allows a single snapshot. Here, we demonstrate click-free mid-infrared photothermal (MIP) imaging of azide-tagged carbohydrates in live cells.

Overtone photothermal microscopy for high-resolution and high-sensitivity vibrational imaging.

Photothermal microscopy is a highly sensitive pump-probe method for mapping nanostructures and molecules through the detection of local thermal gradients. While visible photothermal microscopy and mid-infrared photothermal microscopy techniques have been developed, they possess inherent limitations. These techniques either lack chemical specificity or encounter significant light attenuation caused by water absorption.

Click-free imaging of carbohydrate trafficking in live cells using an azido photothermal probe.

Real-time tracking of intracellular carbohydrates remains challenging. While click chemistry allows bio-orthogonal tagging with fluorescent probes, the reaction permanently alters the target molecule and only allows a single snapshot. Here, we demonstrate click-free mid-infrared photothermal (MIP) imaging of azide-tagged carbohydrates in live cells.

High-content stimulated Raman histology of human breast cancer.

Histological examination is crucial for cancer diagnosis, however, the labor-intensive sample preparation involved in the histology impedes the speed of diagnosis. Recently developed two-color stimulated Raman histology could bypass the complex tissue processing to generates result close to hematoxylin and eosin staining, which is one of the golden standards in cancer histology. Yet, the underlying chemical features are not revealed in two-color stimulated Raman histology, compromising the effectiveness of prognostic stratification.

The Parkinson's drug entacapone disrupts gut microbiome homeostasis via iron sequestration.

Increasing evidence shows that many human-targeted drugs alter the gut microbiome, leading to implications for host health. However, much less is known about the mechanisms by which drugs target the microbiome and how drugs affect microbial function. Here we combined quantitative microbiome profiling, long-read metagenomics, stable isotope probing and single-cell chemical imaging to investigate the impact of two widely prescribed nervous system-targeted drugs on the gut microbiome.

Analytical methods for the detection and characterization of unapproved phosphodiesterase type 5 inhibitors (PDE-5i) used in adulteration of dietary supplements- a review.

This article is an up-to-date review of 112 unapproved phosphodiesterase type 5 inhibitors (PDE-5i) found as adulterants in sexual enhancement dietary supplements and other products from 2003 to July 2023. Seventy-five of these unapproved PDE-5i are analogues of sildenafil (67%), followed by 26 analogues of tadalafil (23%), 9 analogues of vardenafil (8%) and 2 other type of compounds (2%). The products have been formulated in various packaging, primarily in capsule, tablet, and powder forms.

High-throughput single-cell sorting by stimulated Raman-activated cell ejection.

Single-cell sorting is essential to explore cellular heterogeneity in biology and medicine. Recently developed Raman-activated cell sorting (RACS) circumvents the limitations of fluorescence-activated cell sorting, such as the cytotoxicity of labels. However, the sorting throughputs of all forms of RACS are limited by the intrinsically small cross-section of spontaneous Raman scattering.

Stimulated Raman photothermal microscopy toward ultrasensitive chemical imaging.

Stimulated Raman scattering (SRS) microscopy has shown enormous potential in revealing molecular structures, dynamics, and couplings in complex systems. However, the sensitivity of SRS is fundamentally limited to the millimolar level due to shot noise and the small modulation depth. To overcome this barrier, we revisit SRS from the perspective of energy deposition.

Millimeter-deep micron-resolution vibrational imaging by shortwave infrared photothermal microscopy.

Deep-tissue chemical imaging plays a vital role in biological and medical applications. Here, we present a shortwave infrared photothermal (SWIP) microscope for millimeter-deep vibrational imaging with sub-micron lateral resolution and nanoparticle detection sensitivity. By pumping the overtone transition of carbon-hydrogen bonds and probing the subsequent photothermal lens with shortwave infrared light, SWIP can obtain chemical contrast from polymer particles located millimeter-deep in a highly scattering phantom.

Stimulated Raman Photothermal Microscopy towards Ultrasensitive Chemical Imaging.

Stimulated Raman scattering (SRS) microscopy has shown enormous potential in revealing molecular structures, dynamics and coupling in a complex system. However, the bond-detection sensitivity of SRS microscopy is fundamentally limited to milli-molar level due to the shot noise and the small modulation depth in either pump or Stokes beam4. Here, to overcome this barrier, we revisit SRS from the perspective of energy deposition.

Optically-generated focused ultrasound for noninvasive brain stimulation with ultrahigh precision.

High precision neuromodulation is a powerful tool to decipher neurocircuits and treat neurological diseases. Current non-invasive neuromodulation methods offer limited precision at the millimeter level. Here, we report optically-generated focused ultrasound (OFUS) for non-invasive brain stimulation with ultrahigh precision.

Analysis of N-nitrosodimethylamine in metformin hydrochloride products by high-resolution accurate mass gas chromatography mass spectrometry.

Rationale: The high resolving power of the Orbitrap mass spectrometer in a high-resolution accurate mass gas chromatography (HRAM-GC-MS) system provides greater selectivity and sensitivity for the identification and quantification of volatile analytes at low parts per billion (ppb) levels. Hence, it can be applied for the analysis of pharmaceutical impurities like N-nitrosodimethylamine (NDMA) in metformin hydrochloride products (METs).

Methods: Different METs extracted by a dichloromethane/aqueous system were analyzed by HRAM-GC-MS under softer electron ionization (EI) at 30 eV.

Visualization of a Limonene Synthesis Metabolon Inside Living Bacteria by Hyperspectral SRS Microscopy.

Monitoring biosynthesis activity at single-cell level is key to metabolic engineering but is still difficult to achieve in a label-free manner. Using hyperspectral stimulated Raman scattering imaging in the 670-900 cm region, localized limonene synthesis are visualized inside engineered Escherichia coli. The colocalization of limonene and GFP-fused limonene synthase is confirmed by co-registered stimulated Raman scattering and two-photon fluorescence images.

SRS-FISH: A high-throughput platform linking microbiome metabolism to identity at the single-cell level.

One of the biggest challenges in microbiome research in environmental and medical samples is to better understand functional properties of microbial community members at a single-cell level. Single-cell isotope probing has become a key tool for this purpose, but the current detection methods for determination of isotope incorporation into single cells do not allow high-throughput analyses. Here, we report on the development of an imaging-based approach termed stimulated Raman scattering-two-photon fluorescence in situ hybridization (SRS-FISH) for high-throughput metabolism and identity analyses of microbial communities with single-cell resolution.

The Moderation of Human Characteristics in the Control Mechanisms of Rumours in Social Media: The Case of Food Rumours in China.

Social networks are widely used as a fast and ubiquitous information-sharing medium. The mass spread of food rumours has seriously invaded public's healthy life and impacted food production. It can be argued that the government, companies, and the media have the responsibility to send true anti-rumour messages to reduce panic, and the risks involved in different forms of communication to the public have not been properly assessed.

Isolation and characterization of N-phenyl propoxyphenyl carbodenafil from an illegal coffee powder product.

A new carbodenafil-like compound, N-phenyl propoxyphenyl carbodenafil has been identified from an illegal coffee powder product. It was isolated using a semi-preparative liquid chromatography column. The presence of a propoxy group at the aryl alkyl ether moiety, and the direct bonding of a phenyl group to piperazine ring have been unambiguously characterized by ultra-violet (UV), Fourier transform infrared (FTIR), high-resolution mass spectrometry (HRMS) and nuclear magnet resonance (NMR) analysis.