An ammonia-sensitive fluorescence sensor based on polyvinyl alcohol-graphene quantum dots/halloysite nanotubes hybrid film for monitoring fish freshness.

A fluorescent hybrid film composed of nitrogen-doped graphene quantum dots (N-GQDs) loaded on halloysite nanotubes (HNTs) (N-GQDs/HNTs nanocomposite) as a sensitive element and polyvinyl alcohol (PVA) as a film-forming matrix was designed for freshness detection. The PVA-N-GQDs/HNTs hybrid film exhibited significantly enhanced fluorescence attributed to the loading of N-GQDs onto the surface of HNTs through electrostatic interactions and hydrogen bonding, effectively reducing their aggregation. The fluorescence of the hybrid film could be quenched by ammonia via photoinduced electron transfer (PET), with good linearity in the range of 20 ppm to 500 ppm ammonia and a limit of detection (LOD) of 0.63 ppm. In addition, the hybrid film was applied to monitor the freshness of seawater fish and freshwater fish stored at refrigeration and room temperature to evaluate the practicality of this approach. The developed hybrid film showed promise for nondestructive and on-site monitoring of fish spoilage.

Treatment of acral and mucosal melanoma: Current and emerging targeted therapies.

Targeted therapies revolutionized the management of patients with advanced and metastatic cutaneous melanoma. However, despite recent advances in the understanding of the molecular drivers of melanoma and its treatment with targeted therapies, patients with rare and aggressive melanoma subtypes, including acral melanoma (AM) and mucosal melanomas (MM), show limited long-term clinical benefit from current targeted therapies. While patients with AM or MM and BRAF or KIT mutations may benefit from targeted therapies, the frequency of these mutations is relatively low, and there are no genotype-specific treatments for most patients with AM or MM who lack common driver mutations. The poor prognosis of AM and MM can also be attributed to the lack of understanding of their unique molecular landscapes and clinical characteristics, due to being under-represented in preclinical and clinical studies. We review current knowledge of the molecular landscapes of AM and MM, focusing on actionable therapeutic targets and pathways for molecular targeted therapies, to guide the development of more effective targeted therapies for these cancers. Current and emerging strategies for the treatment of these melanoma subtypes using targeted therapies are also summarized.

QD-based fluorescent nanosensors: Production methods, optoelectronic properties, and recent food applications.

Food quality and safety are crucial public health concerns with global significance. In recent years, a series of fluorescence detection technologies have been widely used in the detection/monitoring of food quality and safety. Due to the advantages of wide detection range, high sensitivity, convenient and fast detection, and strong specificity, quantum dot (QD)-based fluorescent nanosensors have emerged as preferred candidates for food quality and safety analysis. In this comprehensive review, several common types of QD production methods are introduced, including colloidal synthesis, self-assembly, plasma synthesis, viral assembly, electrochemical assembly, and heavy-metal-free synthesis. The optoelectronic properties of QDs are described in detail at the electronic level, and the effect of food matrices on QDs was summarized. Recent advancements in the field of QD-based fluorescent nanosensors for trace level detection and monitoring of volatile components, heavy metal ions, food additives, pesticide residues, veterinary-drug residues, other chemical components, mycotoxins, foodborne pathogens, humidity, and temperature are also thoroughly summarized. Moreover, we discuss the limitations of the QD-based fluorescent nanosensors and present the challenges and future prospects for developing QD-based fluorescent nanosensors. As shown by numerous publications in the field, QD sensors have the advantages of strong anti-interference ability, convenient and quick operation, good linear response, and wide detection range. However, the reported assays are laboratory-focused and have not been industrialized and commercialized. Promising research needs to examine the potential applications of bionanotechnology in QD-based fluorescent nanosensors, and focus on the development of smart packaging films, labeled test strips, and portable kits-based sensors.

Interaction and phase behavior of whey protein and propylene glycol alginate complex condensates.

Whey protein (WP) is ubiquitously applied in food products, but its sensitivity to food processing conditions has limited its application. Herein, we chose propylene glycol alginate (PGA) to combine with WP to enhance its stability. The ideal ratio of WP/PGA for coacervation was 3:1, and the soluble complex and insoluble complex were formed at pH 5.2 (pHc) and pH 4.4 (pHφ1) at this ratio, respectively. The UV absorption spectra, fluorescence spectra, and XRD results revealed that the interaction between PGA and WP changed the tertiary conformation of WP. The FTIR and molecular docking results suggested electrostatic interactions, hydrogen bonding and hydrophobic interactions were all involved in the formation of WP-PGA complexes, and the thermal stability of WP was improved based on the DSC results. These findings supported PGA to keep dairy products stable and transparent at the isoelectric point and WP-PGA complexes could be applied in encapsulating bioactive substances.

YAP Activation in Promoting Negative Durotaxis and Acral Melanoma Progression.

Directed cell migration towards a softer environment is called negative durotaxis. The mechanism and pathological relevance of negative durotaxis in tumor progression still requires in-depth investigation. Here, we report that YAP promotes the negative durotaxis of melanoma. We uncovered that the RhoA-myosin II pathway may underlie the YAP enhanced negative durotaxis of melanoma cells. Acral melanoma is the most common subtype of melanoma in non-Caucasians and tends to develop in a stress-bearing area. We report that acral melanoma patients exhibit YAP amplification and increased YAP activity. We detected a decreasing stiffness gradient from the tumor to the surrounding area in the acral melanoma microenvironment. We further identified that this stiffness gradient could facilitate the negative durotaxis of melanoma cells. Our study advanced the understanding of mechanical force and YAP in acral melanoma and we proposed negative durotaxis as a new mechanism for melanoma dissemination.

Evolving Treatment Approaches to Mucosal Melanoma.

PURPOSE OF REVIEW: This review mainly focuses on the unique features and the development of available therapeutic options for mucosal melanoma in different treatment settings, i.e., neoadjuvant, adjuvant, and palliative. RECENT FINDINGS: Mucosal melanoma is distinct from cutaneous melanoma in epidemiology, clinical features, and molecular landscape, characterized by more aggressive biological behavior, lower mutational burden, more chromosomal structure variants, unique driver mutation profile, and distinct tumor microenvironment. Systemic therapy is generally less effective to mucosal melanoma than its cutaneous counterpart. Therapeutic landscape for mucosal melanoma has evolved substantially in recent years: with new targeted therapy options as well as combination therapies built on the backbone of anti-PD-1/PD-L1 antibodies available (esp. anti-angiogenic agent and PD-1/PD-L1 combination), which, based on early phase trial data, seem to be promising. Mucosal melanoma is unique and distinct from cutaneous subtype. Unraveling the unique features of mucosal melanoma is a key to improve clinical outcomes.

A sensitive fluorescence-visualized sensor based on an InP/ZnS quantum dots-sodium rhodizonate system for monitoring fish freshness.

A fluorescence-visualized sensor based on 3-mercaptopropionic acid (MPA)-capped indium phosphide/ zinc sulfide quantum dots (InP/ZnS QDs) and sodium rhodizonate (SR) was designed to sensitively monitor fish freshness. MPA-InP/ZnS QDs, which exhibit orange-red fluorescence, were synthesized by a solvothermal method. In the MPA-InP/ZnS QDs-SR system, the fluorescence of MPA-InP/ZnS QDs was quenched by SR due to the combined function of the inner filter effect (IFE) and static quenching effect (SQE) at pH = 3. When ammonia was added, the fluorescence was recovered, and the color changed from colorless to bright orange-red under UV light (365 nm). The sensing performance for volatile amine gas was studied, and the sensor demonstrated good linearity between the fluorescence intensity, the total volatile basic nitrogen (TVB-N) and the total color change (ΔE) of bighead carp stored at room temperature (25 °C) and refrigerated temperature (4 °C). The proposed sensor has potential applications in monitoring fish freshness.

Nondestructive prediction of freshness for bighead carp (Hypophthalmichthys nobilis) head by Excitation-Emission Matrix (EEM) analysis based on fish eye fluid: Comparison of BPNNs and RBFNNs.

This study established back-propagation neural networks (BPNNs) and radial basis function neural networks (RBFNNs) models for evaluating the freshness of bighead carp head storage at different temperatures via the characteristic components of Excitation-Emission Matrix (EEM). Two characteristic components of EEM data of fish eye fluid were extracted by parallel factor analysis (PARAFAC) and were the most efficient components to stimulate fluorophores responsible for fish freshness detection during variable temperatures. EEM-RBFNNs and EEM-BPNNs models based on characteristic components of EEM used to predict the fish freshness. The results demonstrated the relative errors of EEM-BPNNs models for hiobarbituric acid reactive substances (TBARS) and total viable bacteria count (TAC) prediction were less than 10% which were better than those of EEM-RBFNNs models. It indicated that EEM-BPNNs model of bighead carp eye fluid by PARAFAC has a high potential for predicting fish freshness under variable storage conditions.

Preparation and characterization of intelligent packaging film for visual inspection of tilapia fillets freshness using cyanidin and bacterial cellulose.

An intelligent pH-sensitive film was developed by incorporating cyanidin-3-glucoside (C3G) into bacterial cellulose (BC), and its application as a freshness indicator for tilapia fillets was investigated. The physical properties of the film were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results demonstrated the mechanical properties of the film were significantly changed due to higher crystallinity induced by C3G. XRD and FTIR analysis showed the increased crystallinity and transmittance intensity of the BC-C3G film. Moreover, this film exhibited distinctive color changes from red to green when exposed to buffers with a pH of 3 to 10. In accordance with changes in total volatile basic nitrogen (TVB-N) and total viable count (TVC) of tilapia fillets, the indicator demonstrated visualized color changes as rose-red (fresh), purple (still suitable), and lavender (spoiled) during storage at both 25 °C and 4 °C. The results suggest that this film has great potential to be used as an intelligent indicator to monitor the freshness of fish.

A Highly Sensitive and Selective Fluorescent Probe Using MPA-InP/ZnS QDs for Detection of Trace Amounts of Cu2+ in Water.

Detection of copper (II) ions (Cu2+) in water is important for preventing them from entering the human body to preserve human health. Here, a highly sensitive and selective fluorescence probe that uses mercaptopropionic acid (MPA)-capped InP/ZnS quantum dots (MPA-InP/ZnS QDs) was proposed for the detection of trace amounts of Cu2+ in water. The fluorescence of MPA-InP/ZnS QDs can be quenched significantly in the presence of Cu2+, and the fluorescence intensity shows excellent linearity when the concentration of Cu2+ varies from 0-1000 nM; this probe also exhibits an extremely low limit of detection of 0.22 nM. Furthermore, a possible fluorescence-quenching mechanism was proposed. The MPA-InP/ZnS QDs probes were further applied to the detection of trace Cu2+ in real water samples and drink samples, showing good feasibility.

Comparison of freshness prediction method for salmon fillet during different storage temperatures.

BACKGROUND: Many new forecasting models have been applied to fish freshness prediction like support vector regression (SVR) and radial basis function neural network (RBFNN). In this study, RBFNN, SVR, and Arrhenius models were established and compared for predicting and evaluating the quality of salmon fillets during storage at different temperatures, based on thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), total viable counts (TVCs), K value, and sensory assessment (SA). RESULTS: The TBA, TVB-N, TVC, and K values increased during storage whereas SA decreased. Residuals of the three models are random and irregular, indicating that these models were suitable for predicting the freshness of salmon fillets. The RBFNN predicted quality of salmon fillets stored at different temperatures with relative errors all within ±5% (except for the TVC value at day 6). Relative errors of the SVR model for predicting TVB-N and K value were within 10%, while the relative errors of the Arrhenius model fluctuated greatly (ranging from ±0.46 to ±38.29%) and most of it exceeded 10%. RBFNN model had the best predictive performance by comparing the residual and relative errors of the three models. CONCLUSION: RBFNN is a promising method for predicting the freshness of salmon fillets stored at -2 to 10 °C in the cold chain. © 2021 Society of Chemical Industry.

Intelligent pH indicator films containing anthocyanins extracted from blueberry peel for monitoring tilapia fillet freshness.

BACKGROUND: Fish spoilage leads to an increase in the pH value of the fish. A colorimetric pH indicator can be used to monitor fish spoilage and has been exploited in intelligent packaging because of its simplicity, practicality and low cost. The aim of this study was to develop two pH-indicator films comprising starch (S), tara gum (TG), polyvinyl alcohol (PVA) and anthocyanins extracted from blueberry peel and the films were then used to monitor the freshness of tilapia fillets during storage at 25 and 4 °C. RESULTS: The ultraviolet-visible (UV-visible) spectra and color of anthocyanins changed within pH 2-10. Fourier-transform infrared spectroscopy, UV-visible spectrophotometry and scanning electron microscopy certified that blueberry peel extract (BPE) had been introduced into the S/PVA and TG/PVA matrices. Visual color changes in the films occurred at pH 2-8. A freshness application test was conducted in tilapia fillets stored at 4 and 25 °C, and visual color changes in the films were observed. The TG/PVA/BPE film had a greater color difference (ΔE) from pink and transparent to dark yellow at 25 °C and to dark purple at 4 °C than ΔE of S/PVA/BPE film, which sufficiently correlated with the change of total volatile base nitrogen (TVB-N) and total aerobic counts (TACs) of fillets. CONCLUSION: It can be concluded that the color changes of TG/PVA/BPE films were corresponded with TVB-N and TAC values of tilapia fillets, which presented great potential as a visual package label to monitor fish freshness at ambient and chilled temperatures. © 2020 Society of Chemical Industry.

Current state and progression of advanced melanoma treatment under precision medicine / 中国肿瘤生物治疗杂志

@#[Abstract] In the past, surgery and chemotherapy were the main treatment strategies for malignant melanoma, but companied with poor prognosis. With the development of high-throughput gene sequencing technology and the deepening understanding of tumor molecular mechanisms, it has been found that tumor heterogeneity and the diversity of tumor microenvironment affect tumor formation, drug resistance and treatment selection, leading to different responses and benefits of melanoma patients to the same treatment. The emerge and progression of targeted therapy and immunotherapy have significantly increased the survival rates of patients with metastatic melanoma, promoting the individualization and precision of melanoma treatment and making precise treatment a research hotspot as well as a trend. This review mainly summarizes the research progress of systemic individualized treatment of advanced melanoma based on precise subtyping and molecular level, and to get a more comprehensive view of the survival status of melanoma patients in the era of precision medicine, as well as the prospect and necessity of developing various targeted therapy, immunotherapy or combination therapy.

Review of Methods for the Detection and Determination of Malachite Green and Leuco-Malachite Green in Aquaculture.

Malachite green (MG) has been widely used in the aquaculture industry as a fungicide and parasiticide because of its high efficiency and low cost, and it is commonly found in aquatic products and environmental water. However, MG and its primary metabolite, leuco-malachite green (LMG), are also toxic inorganic contaminants that are hazardous to the health of humans and other organisms. A variety of methods have been proposed in recent years for detecting and monitoring MG and LMG. This article was compiled as a general review of the methods proposed for MG and LMG detection, and several important detection parameters, such as the limit of detection, recovery and relative standard deviation, were tabulated. The analytical methods for the determination of MG and LMG in various matrices include high-performance liquid chromatography separation-based methods, liquid chromatography tandem mass spectrometry, surface-enhanced Raman spectroscopy, electrochemical methods, immunological assays, spectrophotometry and fluorescent methods which were described in detail in this article. In addition, some sample preparation techniques were also described. This review can provide expert guidance to the reader on the advantages, disadvantages and applicability of the different methodologies. This review also discussed challenges and several perspectives on the future trends in the determination of MG and LMG.