How do probiotics alleviate constipation? A narrative review of mechanisms.

Constipation is a common gastrointestinal condition, which may occur at any age and affects countless people. The search for new treatments for constipation is ongoing as current drug treatments fail to provide fully satisfactory results. In recent years, probiotics have attracted much attention because of their demonstrated therapeutic efficacy and fewer side effects than pharmaceutical products. Many studies attempted to answer the question of how probiotics can alleviate constipation. It has been shown that different probiotic strains can alleviate constipation by different mechanisms. The mechanisms on probiotics in relieving constipation were associated with various aspects, including regulation of the gut microbiota composition, the level of short-chain fatty acids, aquaporin expression levels, neurotransmitters and hormone levels, inflammation, the intestinal environmental metabolic status, neurotrophic factor levels and the body's antioxidant levels. This paper summarizes the perception of the mechanisms on probiotics in relieving constipation and provides some suggestions on new research directions.

Broadband frequency comb generation through cascaded quadratic nonlinearity in thin-film lithium niobate microresonators.

Broadband frequency comb generation through cascaded quadratic nonlinearity remains experimentally untapped in free-space cavities with bulk χ(2) materials mainly due to the high threshold power and restricted ability of dispersion engineering. Thin-film lithium niobate (LN) is a good platform for nonlinear optics due to the tight mode confinement in a nano-dimensional waveguide, the ease of dispersion engineering, large quadratic nonlinearities, and flexible phase matching via periodic poling. Here we demonstrate broadband frequency comb generation through dispersion engineering in a thin-film LN microresonator. Bandwidths of 150 nm (80 nm) and 25 nm (12 nm) for center wavelengths at 1560 and 780 nm are achieved, respectively, in a cavity-enhanced second-harmonic generation (doubly resonant optical parametric oscillator). Our demonstration paves the way for pure quadratic soliton generation, which is a great complement to dissipative Kerr soliton frequency combs for extended interesting nonlinear applications.

A humanized trivalent Nectin-4-targeting nanobody drug conjugate displays potent antitumor activity in gastric cancer.

BACKGROUND: Gastric cancer represents a highly lethal malignancy with an elevated mortality rate among cancer patients, coupled with a suboptimal postoperative survival prognosis. Nectin-4, an overexpressed oncological target for various cancers, has been exploited to create antibody-drug conjugates (ADCs) to treat solid tumors. However, there is limited research on Nectin-4 ADCs specifically for gastric cancer, and conventional immunoglobulin G (IgG)-based ADCs frequently encounter binding site barriers. Based on the excellent tumor penetration capabilities inherent in nanobodies (Nbs), we developed Nectin-4-targeting Nb drug conjugates (NDCs) for the treatment of gastric cancer. RESULTS: An immunized phage display library was established and employed for the selection of Nectin-4-specific Nbs using phage display technology. Subsequently, these Nbs were engineered into homodimers to enhance Nb affinity. To prolong in vivo half-life and reduce immunogenicity, we fused an Nb targeting human serum albumin (HSA), resulting in the development of trivalent humanized Nbs. Further, we site-specifically conjugated a monomethyl auristatin E (MMAE) at the C-terminus of the trivalent Nbs, creating Nectin-4 NDC (huNb26/Nb26-Nbh-MMAE) with a drug-to-antibody ratio (DAR) of 1. Nectin-4 NDC demonstrated excellent in vitro cell-binding activities and cytotoxic efficacy against cells with high Nectin-4 expression. Subsequent administration of Nectin-4 NDC to mice bearing NCI-N87 human gastric cancer xenografts demonstrated rapid tissue penetration and high tumor uptake through in vivo imaging. Moreover, Nectin-4 NDC exhibited noteworthy dose-dependent anti-tumor efficacy in in vivo studies. CONCLUSION: We have engineered a Nectin-4 NDC with elevated affinity and effective tumor uptake, further establishing its potential as a therapeutic agent for gastric cancer.

Molecular mechanism of wedelolactone inhibits high glucose-induced human retinal vascular endothelial cells injury through regulating miR-190 expression.

To investigate the effects and molecular mechanisms of wedelolactone (WEL) on high glucose-induced injury of human retinal vascular endothelial cells (HRECs). The cell injury model was established by incubating HRECs with 30 mmol/L glucose for 24 hour. HRECs were divided into control (Con) group, high glucose (HG) group, HG + WEL-low dose (L) group, HG + WEL-medium dose (M), HG + WEL-high dose (H) group, HG + miR-NC group, HG + miR-190 group, HG + WEL + antimiR-NC group, HG + WEL + antimiR-190 group. The kit detects cellular reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) content; cell apoptosis was analyzed by flow cytometry; miR-190 expression was detected by real-time quantitative PCR (RT-qPCR). Compared with Con group, the levels of ROS and MDA in the HG group were significantly increased (P < .01), the SOD activity and the expression of miR-190 expression were significantly decreased (P < .05), and the apoptosis rate was significantly increased (P < .01). Compared with HG group, the levels of ROS and MDA in HG + WEL-L group, HG + WEL-M group and HG + WEL-H group were significantly decreased (P < .05), SOD activity and miR-190 expression were significantly increased (P < .05), and apoptosis rate was significantly reduced (P < .05). Compared with the HG + miR-NC group, the levels of ROS and MDA in HG + miR-190 group were significantly reduced (P < .01), SOD activity was significantly increased (P < .01), and apoptosis rate was significantly reduced (P < .05). Compared with the HG + WEL + antimiR-NC group, the ROS level and MDA content in the HG + WEL + antimiR-190 group were significantly increased (P < .05), SOD activity was significantly decreased (P < .05), and apoptosis rate was significantly increased (P < .05). Wedelolactone can attenuate high glucose-induced HRECs apoptosis and oxidative stress by up-regulating miR-190 expression.

LRFNet: A real-time medical image fusion method guided by detail information.

Multimodal medical image fusion (MMIF) technology plays a crucial role in medical diagnosis and treatment by integrating different images to obtain fusion images with comprehensive information. Deep learning-based fusion methods have demonstrated superior performance, but some of them still encounter challenges such as imbalanced retention of color and texture information and low fusion efficiency. To alleviate the above issues, this paper presents a real-time MMIF method, called a lightweight residual fusion network. First, a feature extraction framework with three branches is designed. Two independent branches are used to fully extract brightness and texture information. The fusion branch enables different modal information to be interactively fused at a shallow level, thereby better retaining brightness and texture information. Furthermore, a lightweight residual unit is designed to replace the conventional residual convolution in the model, thereby improving the fusion efficiency and reducing the overall model size by approximately 5 times. Finally, considering that the high-frequency image decomposed by the wavelet transform contains abundant edge and texture information, an adaptive strategy is proposed for assigning weights to the loss function based on the information content in the high-frequency image. This strategy effectively guides the model toward preserving intricate details. The experimental results on MRI and functional images demonstrate that the proposed method exhibits superior fusion performance and efficiency compared to alternative approaches. The code of LRFNet is available at https://github.com/HeDan-11/LRFNet.

An accurate calculation method for inductor air gap length in high power DC-DC converters.

High-power inductors are fundamental components in high-power DC-DC converters, with their performance being a crucial metric of converter efficiency. This paper presents an in-depth analysis of a novel calculation method for the air gap length in such inductors. Taking into account the effects of air gap diffusion and the winding magnetic field, an expression for the air gap diffusion radius is derived, focusing on a distributed air gap structure. Furthermore, models for calculating the air gap and winding reluctance are developed, grounded in electromagnetic field theory. An equivalent magnetic circuit model, formulated based on Kirchhoff's second law, facilitates the proposed method for air gap length calculation. This study also involves the development of 3D models for both discrete and decoupled integrated inductors. The comparison between simulation outcomes and calculated air gap lengths indicates a maximum error of less than 8%, with the minimum error being as low as - 0.79%. Compared with traditional methods, the calculation method proposed in this paper has significant advantages. Additionally, the discrepancy between calculated values and experimental measurements is found to be 1.11%. These results validate the accuracy and applicability of the theoretical analysis and calculation method, underscoring their significance in the design and optimization of high-power DC-DC converters.

Osteoarthritis versus psoriasis arthritis: Physiopathology, cellular signaling, and therapeutic strategies.

Osteoarthritis and psoriasis arthritis are two degenerative forms of arthritis that share similar yet also different manifestations at the histological, cellular, and clinical levels. Rheumatologists have marked them as two entirely distinct arthropathies. Given recent discoveries in disease initiation and progression, potential mechanisms, cellular signaling pathways, and ongoing clinical therapeutics, there are now more opportunities for discovering osteoarthritis drugs. This review summarized the osteoarthritis and psoriasis arthritis signaling pathways, crosstalk between BMP, WNT, TGF-ß, VEGF, TLR, and FGF signaling pathways, biomarkers, and anatomical pathologies. Through bench research, we demonstrated that regenerative medicine is a promising alternative for treating osteoarthritis by highlighting significant scientific discoveries on entheses, multiple signaling blockers, and novel molecules such as immunoglobulin new antigen receptors targeted for potential drug evaluation. Furthermore, we offered valuable therapeutic approaches with a multidisciplinary strategy to treat patients with osteoarthritis or psoriasis arthritis in the coming future in the clinic.

Performance and mechanism of benzene adsorption on ZnCl2 one-step modified corn cob biochar.

Utilizing cost-effective corn cob, zinc chloride-modified biochar was synthesized through one-step method for benzene adsorption from air. Study on impregnation ratio impact showed optimal benzene adsorption at ZnCl2:CC ratio of 1.5:1, with capacity reaching 170.53 mg g-1. Characterization using BET, SEM, FTIR, and XPS was conducted. BET results indicated specific surface area of Zn1.5BC at 1260.63 m2 g-1 and maximum pore volume of 0.546 m3 g-1. SEM analysis revealed microporous-mesoporous structure in Zn1.5BC, marking significant improvement over original biomass. DFT pore size distribution and FTIR analysis suggested post-modification dehydration and elimination reactions, leading to volatile compound release, functional group reduction, and pore widening. XPS analysis showed decrease in O = C-OH content with increased impregnation ratio, enhancing biochar's π-π electron diffusion for benzene. Langmuir isotherm and pseudo-second-order kinetic models effectively described experimental data, indicating multilayer benzene adsorption on biochar controlled by complex physicochemical adsorption and pore diffusion. Adsorption condition assessment, including adsorption temperature (20-120 â„ƒ) and benzene concentration in inlet phase (159.73-383.36 mg L-1), was performed. Yoon-Nelson model fitting indicated adsorption site loss at higher temperatures and reduced capture ability due to increased adsorbate molecule kinetic energy. Higher adsorbate concentrations aided adsorption molecule diffusion to biochar surface and internal pores, increasing adsorption rate and shortening equilibrium time. Overall, zinc chloride-modified biochar facilitates benzene adsorption through pore filling and π-π interactions, with pore filling as primary mechanism. Produced biochar shows excellent regeneration properties and reusability.

Bifunctional Square-Planar NiO4 Coordination of Topotactic LaNiO2.0 Films for Efficient Oxygen Evolution Reaction.

The high-efficient and low-cost oxygen evolution reaction (OER) is decisive for applications of oxide catalysts in metal-air batteries, electrolytic cells, and energy-storage technologies. Delicate regulations of active surface and catalytic reaction pathway of oxide materials principally determine thermodynamic energy barrier and kinetic rate during catalytic reactions, and thus have crucial impacts on OER performance. Herein, a synergistic modulation of catalytically active surface and reaction pathway through facile topotactic transformations switching from perovskite (PV) LaNiO3.0 film to infinite-layer (IL) LaNiO2.0 film is demonstrated, which absolutely contributes to improving OER performance. The square-planar NiO4 coordination of IL-LaNiO2.0 brings about more electrochemically active metal (Ni+ ) sites on the film surface. Meanwhile, the oxygen-deficient driven PV- IL topotactic transformations lead to a reaction pathway converted from absorbate evolution mechanism to lattice-oxygen-mediated mechanism (LOM). The non-concerted proton-electron transfer of LOM pathway, evidenced by the pH-dependent OER kinetics, further boosts the OER activity of IL-LaNiO2.0 films. These findings will advance the in-depth understanding of catalytic mechanisms and open new possibilities for developing highly active perovskite-derived oxide catalysts.

Insisting on help, facing challenges, and maintaining balance: The lived experiences of caregivers raising a child with developmental delay in the remote islands of Kinmen.

PURPOSE: To explore the lived experiences of the caregivers of children with developmental delay (DD) on the remote island of Kinmen, Taiwan. DESIGN AND METHODS: This descriptive phenomenological study included 14 caregivers of 16 children with DD recruited from Kinmen, Taiwan. Data were collected from September 2020 to February 2021 with face-to-face semi-structured interviews, which were transcribed verbatim and analyzed using thematic analysis. RESULTS: Twelve caregivers were mothers; there was one father and one grandmother. Their mean age was 37.93 ± 5.17 years. The mean age of the children was 3.90 ± 1.49 years; 11 were male (69%). As we began our study, the COVID-19 pandemic occurred, which influenced two of the three themes: (1) focusing on their child's delayed development, which involved seeking a diagnosis and blaming themselves; (2) facing barriers to caring a child with DD on a remote island, which included ostracization of their child and limited off-island medical resources, especially during COVID-19; and (3) maintaining a healthy life balance, which involved protecting their child from physical or spiritual harm, including exposure to COVID-19, and reflecting on their strengths. CONCLUSIONS: Our findings highlight the challenges of caring for a child with DD in the Kinmen islands of Taiwan, and the impact of the COVID-19 pandemic. PRACTICAL IMPLICATIONS: Healthcare professionals are encouraged to provide caregivers of children with DD living in remote, island communities an opportunity to share their caregiving experiences and provide strategies for obtaining medical care, which could help reduce caregiver burden.

A Self-Powered Flexible Displacement Sensor Based on Triboelectric Effect for Linear Feed System.

The detection and feedback of displacement and velocity significantly impact the control accuracy of the linear feed system. In this study, we propose a flexible and self-powered displacement sensor based on the triboelectric effect, designed for seamless integration into linear feed systems. The displacement sensor comprises two parts, the mover and stator, operating in a sliding mode. This sensor can precisely detect the displacement of the linear feed system with a large detection range. Additionally, the sensor is capable of real-time velocity detection of linear feed systems, with an error rate below 0.5%. It also offers advantages, such as excellent flexibility, compact size, stability, easy fabrication, and seamless integration, with linear feed systems. These results highlight the potential of the self-powered displacement sensor for various applications in linear feed systems.

Subchronic exposure to PM2.5 induced renal function damage and intestinal microflora changes in rats.

BACKGROUND: Exposure to inhalable environmental particulate matter with a diameter of 2.5 µm or smaller (PM2.5) is associated with decreased or impaired kidney function, but the underlying biological mechanisms are not fully understood. Gut microbiota is an emerging key player in the homeostasis regulation of the gut-kidney axis. Few studies have investigated its role in PM2.5 exposure-induced gut-kidney axis homeostasis abnormalities. METHODS: In this study, a versatile aerosol concentration enrichment system for medium- to long-term whole-body exposure was used to expose Sprague-Dawley rats to filtered air (FA) or concentrated ambient PM2.5 for 12 weeks. A correlation analysis of renal impairment and the intestinal microbiome was performed. RESULTS: The urine flow rate calculation and renal function analysis showed that PM2.5 exposure significantly impaired renal function and increased the urine flow rate. The fecal microbiota analysis showed that renal impairment and increased urine flow rates were consistent with the reduced estimates of the fecal bacteria Chao1, observed-species, Shannon, and Simpson (richness and diversity indices). Pearson's correlation analysis showed that the estimated bacterial richness and diversity were correlated with the urine flow rate and renal function. The linear discriminant analysis effect size (LEfSe) analysis revealed differences between animals exposed to PM2.5 and FA in 25 bacterial groups. Further correlation of a single bacterial taxon with the urine flow rate and renal function showed that the relative abundances of 30, 29, 21, and 50 distinct bacterial groups were significantly correlated with the urine flow rate, estimated glomerular filtration rate (eGFR), serum cystatin C (CysC), and beta-2 microglobulin (ß2-MG), respectively. CONCLUSION: Subchronic exposure to PM2.5 can cause intestinal ecological disorders, which may, in turn, lead to decreased kidney function or the development of impaired kidney function.

TROP2-directed nanobody-drug conjugate elicited potent antitumor effect in pancreatic cancer.

BACKGROUND: Pancreatic cancer is a highly aggressive malignancy with limited treatment options and a poor prognosis. Trophoblast cell surface antigen 2 (TROP2), a cell surface antigen overexpressed in the tumors of more than half of pancreatic cancer patients, has been identified as a potential target for antibody-drug conjugates (ADCs). Almost all reported TROP2-targeted ADCs are of the IgG type and have been poorly studied in pancreatic cancer. Here, we aimed to develop a novel nanobody-drug conjugate (NDC) targeting TROP2 for the treatment of pancreatic cancer. RESULTS: In this study, we developed a novel TROP2-targeted NDC, HuNbTROP2-HSA-MMAE, for the treatment of TROP2-positive pancreatic cancer. HuNbTROP2-HSA-MMAE is characterized by the use of nanobodies against TROP2 and human serum albumin (HSA) and has a drug-antibody ratio of 1. HuNbTROP2-HSA-MMAE exhibited specific binding to TROP2 and was internalized into tumor cells with high endocytosis efficiency within 5 h, followed by intracellular translocation to lysosomes and release of MMAE to induce cell apoptosis in TROP2-positive pancreatic cancer cells through the caspase-3/9 pathway. In a xenograft model of pancreatic cancer, doses of 0.2 mg/kg and 1 mg/kg HuNbTROP2-HSA-MMAE demonstrated significant antitumor effects, and a dose of 5 mg/kg even eradicated the tumor. CONCLUSION: HuNbTROP2-HSA-MMAE has desirable affinity, internalization efficiency and antitumor activity. It holds significant promise as a potential therapeutic option for the treatment of TROP2-positive pancreatic cancer.

Plant-based production of diverse human milk oligosaccharides.

Human milk oligosaccharides (HMOs) are a diverse class of carbohydrates that aid in the health and development of infants. The vast health benefits of HMOs have made them a commercial target for microbial production; however, producing the ∼130 structurally diverse HMOs at scale has proven difficult. Here, we produce a vast diversity of HMOs by leveraging the robust carbohydrate anabolism of plants. This diversity includes high value HMOs, such as lacto-N-fucopentaose I, that have not yet been commercially produced using state-of-the-art microbial fermentative processes. HMOs produced in transgenic plants provided strong bifidogenic properties, indicating their ability to serve as a prebiotic supplement. Technoeconomic analyses demonstrate that producing HMOs in plants provides a path to the large-scale production of specific HMOs at lower prices than microbial production platforms. Our work demonstrates the promise in leveraging plants for the cheap and sustainable production of HMOs.

Applications of optical property measurement for quality evaluation of agri-food products: a review.

Spectroscopic techniques coupled with chemometric approaches have been widely used for quality evaluation of agricultural and food (agri-food) products due to the nondestructive, simple, fast, and easy characters. However, these techniques face the issues or challenges of relatively weak robustness, generalizability, and applicability in modeling and prediction because they measure the aggregate amount of light interaction with tissues, resulting in the combined effect of absorption and scattering of photons. Optical property measurement could separate absorption from scattering, providing new insights into more reliable prediction performance in quality evaluation, which is attracting increasing attention. In this review, a brief overview of the currently popular measurement techniques, in terms of light transfer principles and data analysis algorithms, is first presented. Then, the emphases are put on the recent advances of these techniques for measuring optical properties of agri-food products since 2000. Corresponding applications on qualitative and quantitative analyses of quality evaluation, as well as light transfer simulations within tissues, were reviewed. Furthermore, the leading groups working on optical property measurement worldwide are highlighted, which is the first summary to the best of our knowledge. Finally, challenges for optical property measurement are discussed, and some viewpoints on future research directions are also given.

HighlightsEmerging techniques for measuring optical properties are briefly introducedQualitative analyses of maturity evaluation and defect detection are reviewedQuantitative analyses of attribute prediction and microstructure estimation are presentedLight transfer simulations based on optical properties are comprehensively discussedLeading groups are summarized for the first time, to the best of our knowledgeChallenges and prospects for optical property measurement are given.

Enhanced formaldehyde oxidation over MnO2 and doped manganese-based catalysts: Experimental and theoretical Insights into mechanism and performance.

Thermal catalytic degradation of formaldehyde (HCHO) over manganese-based catalysts is garnering significant attention. In this study, both theoretical simulations and experimental methods were employed to elucidate the primary reaction pathways of HCHO on the MnO2(110) surface. Specifically, the effects of doping MnO2 with elements such as Fe, Ce, Ni, Co, and Cu on the HCHO oxidation properties were evaluated. Advanced characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS), were employed to discern the physical properties and chemical states of the active components on the catalyst surface. The comprehensive oxidation pathway of HCHO on the MnO2(110) surface includes O2 adsorption and dissociation, HCHO adsorption and dehydrogenation, CO2 desorption, H2O formation and desorption, oxygen vacancy supplementation, and other elementary reactions. The pivotal rate-determining step was identified as the hydrogen migration process, characterized by an energy barrier of 234.19 kJ mol-1. Notably, HCHOO and *CHOO emerged as crucial intermediates during the reaction. Among the doped catalysts, Fe-doped MnO2 outperformed its counterparts doped with Ce, Ni, Co, and Cu. The optimal degradation rate and selectivity were achieved at a molar ratio of Fe: Mn = 0.1. The superior performance of the Fe-doped MnO2 can be ascribed to its large specific surface area, conducive pore structure for HCHO molecular transport, rich surface-adsorbed oxygen species, and a significant presence of oxygen vacancies.

Single-pixel image reconstruction using coherent nonlinear optics.

We propose and experimentally demonstrate a novel, to the best of our knowledge, hybrid optoelectronic system that utilizes mode-selective frequency upconversion, single-pixel detection, and a deep neural network to achieve the reliable reconstruction of two-dimensional (2D) images from a noise-contaminated database of handwritten digits. Our system is designed to maximize the multi-scale structural similarity index measure (MS-SSIM) and minimize the mean absolute error (MAE) during the training process. Through extensive evaluation, we have observed that the reconstructed images exhibit high-quality results, with a peak signal-to-noise ratio (PSNR) reaching approximately 20 dB and a structural similarity index measure (SSIM) of around 0.85. These impressive metrics demonstrate the effectiveness and fidelity of our image reconstruction technique. The versatility of our approach allows its application in various fields, including Lidar, compressive imaging, volumetric reconstruction, and so on.

Focal adhesion kinase (FAK): its structure, characteristics, and signaling in skeletal system.

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase and distributes important regulatory functions in skeletal system. Mesenchymal stem cell (MSC) possesses significant migration and differentiation capacity, is an important source of distinctive bone cells production and a prominent bone development pathway. MSC has a wide range of applications in tissue bioengineering and regenerative medicine, and is frequently employed for hematopoietic support, immunological regulation, and defect repair, although current research is insufficient. FAK has been identified to cross-link with many other keys signaling pathways in bone biology and is considered as a fundamental "crossroad" on the signal transduction pathway and a "node" in the signal network to mediate MSC lineage development in skeletal system. In this review, we summarized the structure, characteristics, cellular signaling, and the interactions of FAK with other signaling pathways in the skeletal system. The discovery of FAK and its mediated molecules will lead to a new knowledge of bone development and bone construction as well as considerable potential for therapeutic use in the treatment of bone-related disorders such as osteoporosis, osteoarthritis, and osteosarcoma.

Analysis of Light Penetration Depth in Apple Tissues by Depth-Resolved Spatial-Frequency Domain Imaging.

Spatial-frequency domain imaging (SFDI) has been developed as an emerging modality for detecting early-stage bruises of fruits, such as apples, due to its unique advantage of a depth-resolved imaging feature. This paper presents theoretical and experimental analyses to determine the light penetration depth in apple tissues under spatially modulated illumination. Simulation and practical experiments were then carried out to explore the maximum light penetration depths in 'Golden Delicious' apples. Then, apple experiments for early-stage bruise detection using the estimated reduced scattering coefficient mapping were conducted to validate the results of light penetration depths. The results showed that the simulations produced comparable or a little larger light penetration depth in apple tissues (~2.2 mm) than the practical experiment (~1.8 mm or ~2.3 mm). Apple peel further decreased the light penetration depth due to the high absorption properties of pigment contents. Apple bruises located beneath the surface peel with the depth of about 0-1.2 mm could be effectively detected by the SFDI technique. This study, to our knowledge, made the first effort to investigate the light penetration depth in apple tissues by SFDI, which would provide useful information for enhanced detection of early-stage apple bruising by selecting the appropriate spatial frequency.

A multi-centre peptidomics investigation of food digesta: current state of the art in mass spectrometry analysis and data visualisation.

Mass spectrometry has become the technique of choice for the assessment of a high variety of molecules in complex food matrices. It is best suited for monitoring the evolution of digestive processes in vivo and in vitro. However, considering the variety of equipment available in different laboratories and the diversity of sample preparation methods, instrumental settings for data acquisition, statistical evaluations, and interpretations of results, it is difficult to predict a priori the ideal parameters for optimal results. The present work addressed this uncertainty by executing an inter-laboratory study with samples collected during in vitro digestion and presenting an overview of the state-of-the-art mass spectrometry applications and analytical capabilities available for studying food digestion. Three representative high-protein foods - skim milk powder (SMP), cooked chicken breast and tofu - were digested according to the static INFOGEST protocol with sample collection at five different time points during gastric and intestinal digestion. Ten laboratories analysed all digesta with their in-house equipment and applying theirconventional workflow. The compiled results demonstrate in general, that soy proteins had a slower gastric digestion and the presence of longer peptide sequences in the intestinal phase compared to SMP or chicken proteins, suggesting a higher resistance to the digestion of soy proteins. Differences in results among the various laboratories were attributed more to the peptide selection criteria than to the individual analytical platforms. Overall, the combination of mass spectrometry techniques with suitable methodological and statistical approaches is adequate for contributing to the characterisation of the recently defined digestome.