Importance of the ECM-receptor interaction for adaptive response to hypoxia based on integrated transcription and translation analysis.

Low dissolved oxygen (LO) conditions represent a major environmental challenge to marine life, especially benthic animals. For these organisms, drastic declines in oxygen availability (hypoxic events) can trigger mass mortality events and thus, act as agents of selection influencing the evolution of adaptations. In sea cucumbers, one of the most successful groups of benthic invertebrates, the exposure to hypoxic conditions triggers adaptive adjustments in metabolic rates and behaviour. It is unclear, however, how these adaptive responses are regulated and the genetic mechanisms underpinning them. Here, we addressed this knowledge gap by assessing the genetic regulation (transcription and translation) of hypoxia exposure in the sea cucumber Apostichopus japonicus. Transcriptional and translational gene expression profiles under short- and long-term exposure to low oxygen conditions are tightly associated with extracellular matrix (ECM)-receptor interaction in which laminin and collagen likely have important functions. Finding revealed that genes with a high translational efficiency (TE) had a relatively short upstream open reading frame (uORF) and a high uORF normalized minimal free energy, suggesting that sea cucumbers may respond to hypoxic stress via altered TE. These results provide valuable insights into the regulatory mechanisms that confer adaptive capacity to holothurians to survive oxygen deficiency conditions and may also be used to inform the development of strategies for mitigating the harmful effects of hypoxia on other marine invertebrates facing similar challenges.

Tunable single frequency Hz-magnitude narrow linewidth Brillouin fiber laser based on parity-time symmetry.

An Hz-magnitude ultra-narrow linewidth single-frequency Brillouin fiber laser (BFL) is proposed and experimentally demonstrated. The single frequency of the laser is selected by parity-time (PT) symmetry, which consists of a stimulated Brillouin scatter (SBS) gain path excited by a 24 km single-mode fiber (SMF) and an approximately equal length loss path tuned with a variable optical attenuator (VOA). These paths are coupled through a fiber Bragg grating (FBG) into a wavelength space. Accomplishing single-frequency oscillation involves the precise adjustment of polarization control (PC) and VOA to attain the PT broken phase. In the experiment, the linewidth of the proposed BFL is 9.58 Hz. The optical signal-to-noise ratio (OSNR) reached 78.89 dB, with wavelength and power fluctuations of less than 1pm and 0.02 dB within one hour. Furthermore, the wavelength can be tuned from 1549.9321 nm to 1550.2575 nm, with a linewidth fluctuation of 1.81 Hz. The relative intensity noise (RIN) is below -74 dB/Hz. The proposed ultra-narrow single-frequency BFL offers advantages such as cost-effectiveness, ease of control, high stability and excellent output characteristics, making it highly promising for the applications in the coherent detection.

Density Functional Theory Calculations on Fluorescence-Enhanced Mechanisms of the Optical Sensor for Zinc Ions, ADPA.

N-(9-anthracenylmethyl)-N-(2-pyridinylmethyl)-2-pyridinemethanamine (ADPA) as a specific ion sensor for Zn2+ has been widely applied. Although the photo-induced electron transfer (PET) mechanism was proposed previously, its fluorescence-enhanced effect still remains somewhat ambiguous, according to unknown influences of non-radiative energy decay pathways, such as intersystem crossing and internal conversion. Herein, a thorough study using density functional theory has been performed for low-lying electronic states of the ADPA monomer and hydrated ADPA-Zn2+ complex. Based on interfragment charge transfer analyses, we quantitatively calculated the amount of transferred electrons in the monomer and complex, providing solid evidences for the PET mechanism and in line with the conclusion of frontier molecular orbital analyses. Moreover, the ISC process of S1→T2 was confirmed to play a considerable role in the excitation energy relaxation process of the ADPA monomer, but this influence was significantly suppressed in the hydrated ADPA-Zn2+ complex. These results provide additional clues for the design of new metal ion-specific fluorescence probes.

The N+ Formation Mechanism of Vibrationally Selected N2O+ Ions in the C2Σ+ State: A TPEPICO Imaging Study.

The N-NO bond fission of N2O+(C2Σ+) ions can produce two major fragment ions, NO+ or N+. In contrast to the dominant NO+ fragment ion, the N+ formation mechanism remains unclear to date. Here, dissociative photoionization of N2O via the C2Σ+ ionic state has been reinvestigated using a combined approach of threshold photoelectron-photoion coincidence (TPEPICO) velocity imaging and quantum chemical calculations. Accompanying the N+(3P) formation, the NO(X2Π) neutral fragment with low and high vi-rotational distributions was identified, based on the N+ speed and angular distributions derived from the TPEPICO images. In particular, the excitation of the symmetric stretching ν1+ mode promotes the formation of high rotational components, while the asymmetric stretching ν3+ mode shows the exact opposite effect. According to our calculated multistate potential energy surfaces, intersystem crossing from C2Σ+ to 14Π exclusively provides feasible decomposition pathways to produce the N+ fragment. In a slightly bent geometry, spin-orbit couplings between C2Σ+ and two substates of 14Π, 14A' or 14A″, play a crucial role in the N+ formation from vibrationally selected N2O+(C2Σ+) ions. The mechanism also provides new insights into the charge transfer reaction of N+ + NO → N + NO+.

Diagnostic significance of cerebrospinal fluid flow cytometry in Chinese children with B lineage acute lymphoblastic leukemia.

BACKGROUND: Central nervous system leukemia (CNSL) is one of the major causes of the poor prognosis of childhood leukemia. We aimed to compare the sensitivity of cytomorphology (CM) and flow cytometry (FCM) in diagnosing CNSL, emphasizing the importance of FCM in the diagnosis process. METHODS: One-hundred-sixty-five children with newly diagnosed B-cell Acute Lymphoblastic Leukemia (B-cell ALL) were included in this study. Cerebrospinal fluid (CSF) samples were taken for routine CSF analysis, CM analysis, and FCM examination. Computed tomography scans and/or magnetic resonance imaging were performed at diagnosis. Patients with CNS2, CNS3, and traumatic lumbar puncture (TLP) at diagnosis received two additional courses of triple intrathecal injections during induction treatment. We compared the sensitivity of FCM and CM in the diagnosis of children with CNSL. RESULTS: One hundred and twenty-eight (77.58%) CSF samples were negative by either CM or FCM (CM-/FCM-), four (2.42%) were positive by both CM and FCM (CM+/FCM+), and thirty-three (20%) displayed a single positive finding by FCM (CM-/FCM+) (p = 0.044). By adding two intrathecal injections in the induction treatment, ten children with TLP+ had no CNS relapse, like those with TLP-. However, compared to CNS1 and TLP, the event-free survival (EFS) did not significantly improve in patients with CNS2 and CNS3. Moreover, CNSL status was associated with worse 3-year EFS (p < 0.05). CONCLUSIONS: We have validated that FCM is more accurate in stratifying the status of the CNS compared to CM analysis. However, to improve the EFS rate of childhood leukemia, it is necessary to combine CM examination, FCM, and cranial imaging for the early diagnosis of CNSL.

Water-Ice Microstructures and Hydration States of Acridinium Iodide Studied by Phosphorescence Spectroscopy.

Ice has been suggested to have played a significant role in the origin of life partly owing to its ability to concentrate organic molecules and promote reaction efficiency. However, the techniques for studying organic molecules in ice are absorption-based, which limits the sensitivity of measurements. Here we introduce an emission-based method to study organic molecules in water ice: the phosphorescence displays high sensitivity depending on the hydration state of an organic salt probe, acridinium iodide (ADI). The designed ADI aqueous system exhibits phosphorescence that can be severely perturbed when the temperature is higher than 110 K at a concentration of the order of 10-5 M, indicating changes in hydration for ADI. Using the ADI phosphorescent probe, it is found that the microstructures of water ice, i.e., crystalline vs. glassy, can be strongly dictated by a trace amount (as low as 10-5 M) of water-soluble organic molecules. Consistent with cryoSEM images and temperature-dependent Raman spectral data, the ADI is dehydrated in more crystalline ice and hydrated in more glassy ice. The current investigation serves as a starting point for using more sensitive spectroscopic techniques for studying water-organics interactions at a much lower concentration and wider temperature range.

Research progress on chitin/chitosan-based emulsion delivery systems and their application in lipid digestion regulation.

Excessive lipid intake is linked to an elevated risk of health problems. However, reducing lipid contents may influence food structure and flavor. Some alternatives are needed to control the lipid absorption. Emulsions are common carriers for lipids, which can control the hydrolysis and absorption of lipids. Chitin (Ch) and chitosan (CS) are natural polysaccharides with good biodegradability, biocompatibility, and unique cationic properties. They have been reported to be able to delay lipolysis, which can be regarded as one of the most promising agents that regulates lipid digestion (LiD). The application of Ch/CS and their derivatives in emulsions are summarized in this review with a focus on their performances and mechanisms for LiD regulation, aiming to provide theoretical guidance for the development of novel Ch/CS emulsions, and the regulation of LiD. A reasonable design of emulsion interface can provide its resistance to the external environment and then control LiD. The properties of emulsion interface are the key factors affecting LiD. Therefore, systematic study on the relationship between Ch/CS-based emulsion structure and LiD can not only instruct the reasonable design of emulsion interface to accurately regulate LiD, but also provide scientific guidelines for applying Ch/CS in functional food, medicine and other fields.

Application of chitin/chitosan and their derivatives in emulsionsStrategies to improve emulsifying properties of chitin/chitosanDigestion behaviors of chitin/chitosan emulsions during gastrointestinal digestionRational design and potential mechanism of chitin/chitosan to regulate lipolysis.

Comparing the efficacy and safety of different thread-drawing surgery method for treating high complex anal fistula: a systematic review and network meta-analysis.

PURPOSE: To evaluate the effect of different surgical methods in the treatment of high complex anal fistula by systematic review and network meta-analysis. METHODS: Randomized controlled trials that met the inclusion criteria in PubMed, Cochrane Library, Embase, Web of Science, CBM, CNKI, WANFANG DATA, VIP were searched from the date of database construction to May 23, 2023. RESULTS: Among the 48 randomized controlled trials (RCTs), 4205 patients were included in the network meta-analysis. Incision thread-drawing counter-drainage procedure (ITCP) in improving the effective rate, the cure rate; reduce the recurrence rate, reduce the anal canal damage has a huge advantage. Directional line-hanging method (DLM) is optimal for safety and postoperative pain relief. Directional line-hanging method (ITSS) protect the optimal anal function after surgery. Sphincter preserving thread-hanging method (SPTM) has a significant advantage in accelerating wound healing time. Main tube incision combined with thread-hanging branch tube drainage (MIBD) is second only to incision thread-drawing counter-drainage procedure (ITCP) in improving effective rate, cure rate, reducing recurrence rate and reduce complication rate. CONCLUSION: In general, different thread-drawing surgery methods have good clinical effect for the treatment of high complex anal fistula. In general, these methods provide evidence-based medical evidence for early treatment in terms of improving clinical efficacy, relieving anal pain and reducing wound healing time. However, there are differences in the number of included literature studies, and further verification by large-sample, high-quality, multicenter RCTS is still needed in the next stage.

Infrared photodissociation spectroscopy of mass-selected [TaO3(CO2)n]+ (n = 2-5) complexes in the gas phase.

We report a joint experimental and theoretical study on the structures of gas-phase [TaO3(CO2)n]+ (n = 2-5) ion-molecule complexes. Infrared photodissociation spectra of mass-selected [TaO3(CO2)n]+ complexes were recorded in the frequency region from 2200 to 2450 cm-1 and assigned through comparing with the simulated infrared spectra of energetically low-lying structures derived from quantum chemical calculations. With the increasing number of attached CO2 molecules, the larger clusters show significantly enhanced fragmentation efficiency and a strong band appears at around 2350 cm-1 near the free CO2 antisymmetric stretching vibration band, indicating only a small perturbation of CO2 molecules on the secondary solvation sphere while higher frequency bands corresponding to the core structure remain largely unaffected. A core structure [TaO3(CO2)3]+ is identified to which subsequent CO2 ligands are weakly attached and the most favorable cluster growth path is verified to proceed on the triplet potential energy surface higher in energy than that of ground states. Theoretical exploration reveals a two-state reactivity (TSR) scenario in which the energetically favored triplet transition state crosses over the singlet ground state to form a TaO3+ core ion, providing new information on the cluster formation correlated with the reactivity of tantalum metal oxides towards CO2.

Dependence of Intramolecular Hydrogen Bond on Conformational Flexibility in Linear Aminoalcohols.

Intramolecular hydrogen bonds (H-bonds) are abundant in physicochemical and biological processes. The strength of such interaction is governed by a subtle balance between conformational flexibility and steric effect that are often hard to predict. Herein, using linear aminoalcohols NH2(CH2)nOH (n = 2-5) as a model system, we demonstrated the dependence of intramolecular H-bond on the backbone chain length. With sensitive photoacoustic Raman spectroscopy (PARS), the gas-phase Raman spectra of aminoalcohols were measured in both N-H and O-H stretching regions at 298 and 338 K and explained with the aid of quantum chemistry calculations. For n = 2-4, two conformers corresponding to the O-H···N intramolecular H-bond and free OH were identified, whereas for n = 5, only the free-OH conformer was identified. Compared to free OH, a striking spectral dependence was observed for the intramolecular H-bonded conformer. According to the red shift of the OH-bonded band, the strongest intramolecular H-bond yields in n = 4, but the favorable chain length to form an intramolecular hydrogen bond at room temperature was observed in n = 3, which corresponds to a six-membered-ring in 3-aminopropanol. This is in good agreement with statistical analysis from the Cambridge Structural Database (CSD) that the intramolecular hydrogen bond is preferred when the six-membered ring is formed. Furthermore, combined with the calculated thermodynamic data at the MP2/aug-cc-pVTZ//M062X/6-311++G(d,p) level, the origin of decrease in intramolecular hydrogen-bond formation was ascribed to an unfavorable negative entropy contribution when the backbone chain is further getting longer, which results in the calculated Gibbs free energy optimum changing with increasing temperature from n = 4 (0-200 K) to n = 3 (200-400 K) and to n = 2 (above 400 K). These results will provide new insight into the nature of intramolecular hydrogen bonds at the molecular level and the application of intramolecular hydrogen bonds in rational drug design and supramolecular assembly.

Metabolomic insights into neurological effects of BDE-47 exposure in the sea cucumber Apostichopus japonicus.

The persistent organic pollutant 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), a prevalent congener among polybrominated diphenyl ethers (PBDEs), exhibits potent bioaccumulation and toxicity. Despite extensive research into the adverse effects of BDE-47, its neurotoxicity in sea cucumbers remains unexplored. Given the crucial role of the sea cucumber's nervous system in survival and adaptation, evaluating the impacts of BDE-47 is vital for sustainable aquaculture and consumption. In this study, we employed ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Triple-TOF-MS) to analyze metabolomic changes in neuro-related tissues of Apostichopus japonicus exposed to low (0.1 µg/L), medium (1.0 µg/L), and high (10.0 µg/L) BDE-47 concentrations. We identified significantly changed metabolites in each exposure group (87 in low, 79 in medium, and 102 in high), affecting a variety of physiological processes such as steroid hormone balance, nucleotide metabolism, energy metabolism, neurotransmitter levels, and neuroprotection. In addition, we identified concentration-dependent, common, and some other metabolic responses in the neuro-related tissues. Our findings reveal critical insights into the neurotoxic effects of BDE-47 in sea cucumbers and contribute to risk assessment related to BDE-47 exposure in the sea cucumber industry, paving the way for future neurotoxicological research in invertebrates.

Single-Cell Transcriptome and Pigment Biochemistry Analysis Reveals the Potential for the High Nutritional and Medicinal Value of Purple Sea Cucumbers.

The sea cucumber Apostichopus japonicus has important nutritional and medicinal value. Unfortunately, we know little of the source of active chemicals in this animal, but the plentiful pigments of these animals are thought to function in intriguing ways for translation into clinical and food chemistry usage. Here, we found key cell groups with the gene activity predicted for the color morphology of sea cucumber body using single-cell RNA-seq. We refer to these cell populations as melanocytes and quinocytes, which are responsible for the synthesis of melanin and quinone pigments, respectively. We integrated analysis of pigment biochemistry with the transcript profiles to illuminate the molecular mechanisms regulating distinct pigment formation in echinoderms. In concert with the correlated pigment analysis from each color morph, this study expands our understanding of medically important pigment production, as well as the genetic mechanisms for color morphs, and provides deep datasets for exploring advancements in the fields of bioactives and nutraceuticals.

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This article reports two cases of children with B-cell acute lymphoblastic leukemia (B-ALL) complicated by invasive fungal disease (IFD) who received bridging treatment using blinatumomab. Case 1 was a 4-month-old female infant who experienced recurrent high fever and limb weakness during chemotherapy. Blood culture was negative, and next-generation sequencing (NGS) of peripheral blood, bronchoalveolar lavage fluid, and cerebrospinal fluid were all negative. Chest CT and cranial MRI revealed obvious infection foci. Case 2 was a 2-year-old male patient who experienced recurrent high fever with multiple inflammatory masses during chemotherapy. Candida tropicalis was detected in peripheral blood and abscess fluid using NGS, while blood culture and imaging examinations showed no obvious abnormalities. After antifungal and blinatumomab therapy, both cases showed significant improvement in symptoms, signs, and imaging, and B-ALL remained in continuous remission. The report indicates that bridging treatment with blinatumomab in children with B-ALL complicated by IFD can rebuild the immune system and control the underlying disease in the presence of immunosuppression and severe fungal infection.

A Natural Hydrogel with Prohealing Properties Enhances Tendon Regeneration.

Tendon regeneration and reduction of peritendinous adhesion remain major clinical challenges. This study addresses these challenges by adopting a unique hydrogel derived from the skin secretion of Andrias davidianus (SSAD) and taking advantage of its biological effects, adhesiveness, and controllable microstructures. The SSAD-derived hydrogel contains many cytokines, which could promote tendon healing. In vitro, leach liquid of SSAD powder could promote tendon stem/progenitor cells migration. In vivo, the SSAD-derived hydrogel featuring double layers possesses strong adhesiveness and could reconnect ruptured Achilles tendons of Sprague-Dawley rats without suturing. The intimal SSAD-derived hydrogel, with a pore size of 241.7 ± 21.0 µm, forms the first layer of the hydrogel to promote tendon healing, and the outer layer SSAD-derived hydrogel, with a pore size of 3.3 ± 1.4 µm, reducing peritendinous adhesion by serving as a dense barrier. Additionally, the SSAD-derived hydrogel exhibits antioxidant and antibacterial characteristics, which further contribute to the reduction of peritendinous adhesion. In vivo studies suggest that the SSAD-derived hydrogel reduces peritendinous adhesion, increases collagen fiber deposition, promotes cell proliferation, and improves the biomechanical properties of the regenerated tendons, indicating better functional restoration. The SSAD-derived bilayer hydrogel may be a feasible biomaterial for tendon repair in the future.

Vibrational mode-specific polarization effect in circularly polarized stimulated Raman scattering.

As one of the popular coherent Raman scattering techniques, stimulated Raman scattering (SRS) has made significant progress in recent years, especially in label-free biological imaging. Polarization provides an additional degree of freedom to manipulate the SRS process. In previous studies, only linearly polarized SRS was fully investigated, in which both pump and Stokes laser fields are linearly polarized. Here, we theoretically analyzed the SRS process excited by two circularly polarized laser fields and then experimentally demonstrated it by taking a spherical symmetric CH4 molecule as a model system. The experimental results are in good agreement with the theoretical ones. It is shown that circularly polarized SRS (CP-SRS) has unique characteristics different from linear polarization. When the handedness of circular polarization states of two laser fields is the same, CP-SRS further suppresses the depolarized vibrational band while keeping the polarized band almost unaffected. On the other hand, when the handedness is opposite, CP-SRS enhances the depolarized band while suppressing the polarized band. Therefore, the CP-SRS not only allows us to resolve the symmetry of vibrational modes but also can enhance vibrational contrast based on symmetry selectivity by suppressing or enhancing the signal from a specific vibrational mode. These results will have potential applications in improving chemical selectivity and imaging contrast as well as spectral resolution SRS microscopy. In addition, the CP-SRS has the ability to determine the depolarization ratio ρ and identify the overlapping Raman bands.

Curcumin and Its Analogs as Potential Epigenetic Modulators: Prevention of Diabetes and Its Complications.

BACKGROUND: The pathobiology of diabetes and associated complications has been widely researched in various countries, but effective prevention and treatment methods are still insufficient. Diabetes is a metabolic disorder of carbohydrates, fats, and proteins caused by an absence of insulin or insulin resistance, which mediates an increase of oxidative stress, release of inflammatory factors, and macro- or micro-circulation dysfunctions, ultimately developing into diverse complications. SUMMARY: In the last decade through pathogenesis research, epigenetics has been found to affect metabolic diseases. Particularly, DNA methylation, histone acetylation, and miRNAs promote or inhibit diabetes and complications by regulating the expression of related factors. Curcumin has a wide range of beneficial pharmacological activities, including anti-inflammatory, anti-oxidation, anticancer, anti-diabetes, anti-rheumatism, and increased immunity. Key Messages: In this review, we discuss the effects of curcumin and analogs on diabetes and associated complications through epigenetics, and we summarize the preclinical and clinical researches for curcumin and its analogs in terms of management of diabetes and associated complications, which may provide an insight into the development of targeted therapy of endocrine diseases.

Dynamic Poly(dimethylsiloxane) Brush Coating Shows Even Better Antiscaling Capability than the Low-Surface-Energy Fluorocarbon Counterpart.

Scale formation is a significant problem in a wide range of industries, including water treatment, food processing, power plants, and oilfield production. While surface modification provides a promising methodology to address this challenge, it has generally been believed that surface coatings with the lowest surface energy, such as fluorocarbon coatings, are most suitable for antiscaling applications. In contrast to this general knowledge, here we show that a liquid-like coating featuring highly mobile linear poly(dimethylsiloxane) (LPDMS) brush chains can bring an even better antiscaling performance than conventional perfluoroalkylsilane coatings, despite the fact that the former has much higher surface energy than the latter. We demonstrate that the LPDMS brush coating can more effectively inhibit heterogeneous nucleation of scale on a substrate compared with common perfluoroalkylsilane or alkylsilane coatings, and the dynamic liquid-like characteristic of the LPDMS brush coating is speculated to be responsible for its excellent nucleation inhibiting ability by reducing the affinity and effective interface interaction between the substrate and the scale nucleus. Our findings reveal the great prospect of using liquid-like coating to replace environmentally hazardous fluorine-containing organic ones as a green and cost-effective solution to address the scale problem with enhanced antiscaling performance.

Ro-vibrational Distribution of NO+ Dissociated from NO2+ Ions in the a3B2 and b3A2 States: A Slow "Impulsive" Dissociation Example Revealed from Threshold Photoelectron-Photoion Coincidence Imaging.

To clarify the contentions about dissociative photoionization mechanism of nitrogen dioxide via the a3B2 and b3A2 ionic states, a new threshold photoelectron-photoion coincidence (TPEPICO) velocity imaging has been conducted in the 12.8-14.0 eV energy range at the Hefei Light Source. The fine vibrational-resolved threshold photoelectron spectrum agrees well with the previous measurements. The ro-vibrational distributions of NO+, as the unique fragment ion in the dissociation of NO2+ in specific vibronic levels of a3B2 and b3A2 states, are derived from the recorded TPEPICO velocity images. A "cold" vibrational (v+ = 0) and "hot" rotational population is observed at the a3B2(0,3,0) and (0,4,0) vibronic levels, while the dissociation of NO2+ in b3A2(0,0,0) leads to the NO+ fragment with both hot vibrational and rotational populations. With the aid of the quantum chemical calculations at the time-dependent B3LYP level, minimum energy paths on the potential energy surfaces of the a3B2 and b3A2 states clarify their adiabatic dissociation mechanisms near the thresholds, and this study proposes reliable explanations for the observed internal energy distributions of fragment ions. Additionally, this study provides valuable insights into the application of the classical "impulsive" model on an overall slow dissociation process.

Electron Affinity and Electronic Structure of Hexafluoroacetone (HFA) Revealed by Photodetaching the [HFA]•- Radical Anion.

A great deal of effort has been focused on developing a metal-free catalytic system for epoxidation of unreactive alkenes. Fluoroketones are thought as remarkably promising catalysts for epoxidation reactions. The combination of fluorinated alcohols and catalytic amounts of hexafluoroacetone (HFA) gives a versatile and effective medium for epoxidation of various olefins with hydrogen peroxide. However, the fundamental physicochemical properties of HFA remained largely unclear, although they were very important to understand the related interactions. Here, we performed a joint study on the electron affinity and electronic structure of HFA employing negative ion photoelectron (NIPE) spectroscopy and quantum chemistry calculations. Two distinct bands with complicated vibrational progressions were observed in the 193 nm NIPE spectrum. The adiabatic/vertical detachment energies (ADE/VDE) were derived to be 1.42/2.06 and 4.43/4.86 eV for the ground singlet state and excited triplet state, respectively. Using the optimized geometries and vibrational frequencies of the anion and the neutral, the Franck-Condon factors were calculated for electron detachments to produce HFA in its lowest singlet and triplet states. Good agreements are obtained hereby for both bands between the experimental and calculated NIPE spectra, when taking into account combination vibrational excitations, unequivocally revealing that HFA possesses a singlet ground state with a giant singlet-triplet energy difference (ΔEST). The electron affinity (EA) and ΔEST of HFA were therefore determined to be EA = 1.42 ± 0.02 eV and ΔEST = -3.01 eV.

Effect of chronic exposure to microplastic fibre ingestion in the sea cucumber Apostichopus japonicus.

Microplastics (MPs) in the form of microfibres (MFs) are of great concern because of their size and increasing abundance, which increase their potential to interact with or be ingested by aquatic organisms. Although MFs are the dominant shape of MPs ingested by sea cucumbers in habitats, their effect on sea cucumbers remains unclear. This study examined the effect of dietary exposure to MFs on the growth and physiological status of both juvenile and adult Apostichopus japonicus sea cucumbers. MFs were mixed into the diet of sea cucumbers for 60 d at environmentally relevant concentrations of 0.6 MFs g-1, 1.2 MFs g-1 and 10 MFs g-1. Dietary exposure to MFs, with concentrations at or above those commonly found in the habitats, did not significantly affect the growth and faecal production rate of either juvenile or adult sea cucumbers. However, a disruption in immunity indices (acid phosphatase and alkaline phosphatase activity) and oxidative stress indices (total antioxidant capacity and malondialdehyde content) was observed in juvenile and adult sea cucumbers, indicating that these indices might be useful as potential biomarkers of the exposure to MF ingestion in sea cucumbers. This study provides insights into the toxicity mechanism of MF ingestion in a commercially and ecologically important species.