Automatic high-throughput and non-invasive selection of sperm at the biochemical level.

BACKGROUND: Sperm selection, a key step in assisted reproductive technology (ART), has long been restrained at the preliminary physical level (morphology or motility); however, subsequent fertilization and embryogenesis are complicated biochemical processes. Such an enormous "gap" poses tough problems for couples dealing with infertility, especially patients with severe/total asthenozoospermia . METHODS: We developed a biochemical-level, automatic-screening/separation, smart droplet-TO-hydrogel chip (BLASTO-chip) for sperm selection. The droplet can sense the pH change caused by sperm's respiration products and then transforms into a hydrogel to be selected out. FINDINGS: The BLASTO-chip system can select biochemically active sperm with an accuracy of over 90%, and its selection efficiency can be flexibly tuned by nearly 10-fold. All the substances in the system were proven to be biosafe via evaluating mice fertilization and offspring health. Live sperm down to 1% could be enriched by over 76-fold to 76%. For clinical application to patients with severe/total asthenozoospermia, the BLASTO-chip could select live sperm from human semen samples containing 10% live but 100% immotile sperm. The rates of fertilization, cleavage, early embryos, and blastocysts were drastically elevated from 15% to 70.83%, 10% to 62.5%, 5% to 37.5%, and 0% to 16.67%, respectively. CONCLUSIONS: The BLASTO-chip represents a real biochemical-level technology for sperm selection that is completely independent of sperm's motility. It can be a powerful tool in ART, especially for patients with severe/total asthenozoospermia. FUNDING: This work was funded by the Ministry of Science and Technology of China, the Ministry of Education of China, and the Shenzhen-Hong Kong Hetao Cooperation Zone.

RSPO3 induced by Helicobacter pylori extracts promotes gastric cancer stem cell properties through the GNG7/ß-catenin signaling pathway.

BACKGROUND: Helicobacter pylori (H. pylori) accounts for the majority of gastric cancer (GC) cases globally. The present study found that H. pylori promoted GC stem cell (CSC)-like properties, therefore, the regulatory mechanism of how H. pylori promotes GC stemness was explored. METHODS: Spheroid-formation experiments were performed to explore the self-renewal capacity of GC cells. The expression of R-spondin 3 (RSPO3), Nanog homeobox, organic cation/carnitine transporter-4 (OCT-4), SRY-box transcription factor 2 (SOX-2), CD44, Akt, glycogen synthase kinase-3ß (GSK-3ß), p-Akt, p-GSK-3ß, ß-catenin, and G protein subunit gamma 7 (GNG7) were detected by RT-qPCR, western blotting, immunohistochemistry (IHC), and immunofluorescence. Co-immunoprecipitation (CoIP) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) were performed to identify proteins interacting with RSPO3. Lentivirus-based RNA interference constructed short hairpin (sh)-RSPO3 GC cells. Small interfering RNA transfection was performed to inhibit GNG7. The in vivo mechanism was verified using a tumor peritoneal seeding model in nude mice. RESULTS: H. pylori extracts promoted a CSC-like phenotype in GC cells and elevated the expression of RSPO3. RSPO3 knockdown significantly reduced the CSC-like properties induced by H. pylori. Previous studies have demonstrated that RSPO3 potentiates the Wnt/ß-catenin signaling pathway, but the inhibitor of Wnt cannot diminish the RSPO3-induced activation of ß-catenin. CoIP and LC-MS/MS revealed that GNG7 is one of the transmembrane proteins interacting with RSPO3, and it was confirmed that RSPO3 directly interacted with GNG7. Recombinant RSPO3 protein increased the phosphorylation level of Akt and GSK-3ß, and the expression of ß-catenin in GC cells, but this regulatory effect of RSPO3 could be blocked by GNG7 knockdown. Of note, GNG7 suppression could diminish the promoting effect of RSPO3 to CSC-like properties. In addition, RSPO3 suppression inhibited MKN45 tumor peritoneal seeding in vivo. IHC staining also showed that RSPO3, CD44, OCT-4, and SOX-2 were elevated in H. pylori GC tissues. CONCLUSION: RSPO3 enhanced the stemness of H. pylori extracts-infected GC cells through the GNG7/ß-catenin signaling pathway.

Multifunctional fluorescent probe for simultaneous revealing Cys and ONOO- dynamic correlation in the ferroptosis.

Ferroptosis is a type of lipid peroxidation-induced apoptosis brought on by imbalances in iron metabolism and redox. It involves both the thiol-associated anti-ferroptosis pathway and the excessive buildup of reactive oxygen species (ROS), which stimulates the ferroptosis pathway. Determining the precise control mechanism of ferroptosis requires examining the dynamic connection between reactive sulfur species (RSS) and ROS. Cysteine (Cys) and peroxynitrite (ONOO-) are highly active redox species in organisms and play dynamic roles in the ferroptosis process. In this study, a coumarin dye was conjugated with specific response sites for Cys and ONOO-, enabling the simultaneous detection of Cys and ONOO- through the green and red fluorescence channels, respectively (λem = 498 nm for Cys and λem = 565 nm for ONOO-). Using the probe LXB, we monitored the changes in Cys and ONOO- levels in the ferroptosis pathway induced by erastin. The results demonstrate a significant generation of ONOO- and a noticeable decrease in intracellular Cys levels at the beginning upon erastin treatment and finally maintains a relatively low level. This study presents the first probe to investigate the intracellular redox modulation and control between Cys and ONOO- during ferroptosis, providing valuable insights into the potential mutual correlation between Cys and ONOO- in this process.

First report of Fusarium commune Causing Bulb Rot on Lily (Lilium brownii var. Viridulum Baker) in Hunan Province of China.

Lily (Lilium brownii var. Viridulum Baker) is a well-known edible plant with large, white and sweet bulb scales that has important medicinal value (Zhou et al. 2021) and is grown mainly in the Hebei, Shanxi and Henan provinces of China. In May 2021, a case of bulb rot was discovered in a 3.33 hm2 plantation in Huaihua, Hunan Province, affecting 20% of the area (27°59'30″N, 110°32'20″E). The disease is most severe during the rainy season in May and June. In the early stage, irregular brown spots appeared on the lily scales, the necrosis was depressed and gradually enlarges, and in the later stage, the scales were scattered from the base of the disc and slough off. Ten samples were taken randomly from different plants in the plantation area to isolate the pathogens. After washing with sterile water, they were cut into small pieces and sterilised with 3% hydrogen peroxide for 30 s, 75% ethanol for 90 s, rinsed three times with sterile water and dried on sterile filter paper, then placed on a water agar plate and incubated in the dark in a constant temperature incubator at 28℃ for 3 to 5 days. After 2 days, the mycelium at the edge of the colony was transferred to a PDA plate and incubated for 3-5 days at 28°C in the dark to obtain pure fungal isolates. Eighteen purified fungal isolates were obtained, of which sixteen looked like Fusarium (88.9% isolation rate) and three representative isolates (BHBR2, BHBR3 and BHBR5) were selected for further study. The surface of this fungus was white with dense aerial mycelium. Some had an orange centre in the medium. Microconidia were oval in shape and appeared either straight or slightly curved. These microconidia were colourless, had 0-1 septa and measured 3.334 to 14.724 × 2.216 to 5.385 µm (n=100). Macroconidia were predominantly three-septate, crescent-shaped structures that were thin-walled and slightly curved. Cells at the apex and base were similarly curved. Macroconidia measured 17.956 to 32.150 × 2.788 to 4.492 µm (n=100). The mitochondrial small subunit (mtSSU) and translation elongation factor 1-α (TEF1) genes were amplified and sequenced using the NMS1/NMS2 and TEF-R/TEF-F primers to verify the identity of the pathogens (Stewart et al. 2006). The sequences were submitted to GenBank (BHBR2: mtSSU, PP273435; TEF, OR900976; BHBR3: mtSSU, PP277729; TEF, OR900977; BHBR5: mtSSU, PP277728; TEF, OR900978). A concatenated phylogenetic tree of the two genes was constructed and analysis showed that BHBR2, BHBR3 and BHBR5 were significantly clustered with Fusarium commune. Based on the results of morphological identification and phylogenetic tree analysis, the three isolates were identified as Fusarium commune. We carried out pathogenicity tests using two methods, one in which 6 × 6 mm fungal blocks were inoculated on lily (L. brownie var. viridulum Baker) scales and controls inoculated with sterile blocks, and the other in which strain BHBR2 was selected to carry out pathogenicity tests on bulbs of live plants soaked with 50 ml of a 1 × 106 conidial suspension and bulbs of control plants soaked with sterile water, all in three replicates. They were placed in a growth chamber at 28°C and 80% relative humidity, and the scales were moistened with moistened sterile filter paper. After 3 days of rearing treated scales, lesions appeared on lily scales inoculated with mycelial blocks and expanded with time, whereas no lesions appeared on lily scales inoculated with sterile blocks. One month later, whole plants soaked in the spore suspension wilted, while the control plants grew well. The pathogens re-isolated from the diseased tissues had the same morphological characteristics as representative isolates. This confirms Koch's hypothesis. Fusarium commune has been shown to be the most important pathogenic fungus causing root rot in Alfalfa (Medicago sativa) (Yang et al. 2022) and blueberry (Vaccinium uliginosum L.) (Li et al. 2023) in China. To our knowledge, this is the first report of Fusarium commune causing lily bulb rot in the world, which will lay the foundation for future control of lily bulb rot.

Toll/interleukin-1 receptor (TIR) domain-containing proteins have NAD-RNA decapping activity.

The occurrence of NAD+ as a non-canonical RNA cap has been demonstrated in diverse organisms. TIR domain-containing proteins present in all kingdoms of life act in defense responses and can have NADase activity that hydrolyzes NAD+. Here, we show that TIR domain-containing proteins from several bacterial and one archaeal species can remove the NAM moiety from NAD-capped RNAs (NAD-RNAs). We demonstrate that the deNAMing activity of AbTir (from Acinetobacter baumannii) on NAD-RNA specifically produces a cyclic ADPR-RNA, which can be further decapped in vitro by known decapping enzymes. Heterologous expression of the wild-type but not a catalytic mutant AbTir in E. coli suppressed cell propagation and reduced the levels of NAD-RNAs from a subset of genes before cellular NAD+ levels are impacted. Collectively, the in vitro and in vivo analyses demonstrate that TIR domain-containing proteins can function as a deNAMing enzyme of NAD-RNAs, raising the possibility of TIR domain proteins acting in gene expression regulation.

[Application of high hip center technique in total hip arthroplasty in patients with Crowe typeâ ¡and â ¢ developmental dysplasia of hip and severe hip osteoarthritis].

OBJECTIVE: To explore the clinical efficacy of high hip center technique total hip arthroplasty （THA） for Crowe Ⅱand Ⅲ developmental dysplasia of hip （DDH） and severe hip osteoarthritis （HOA）. METHODS: From January 2018 to January 2020, 74 patients with Crowe typeⅡand Ⅲ DDH and severe HOA were admitted, and 37 cases of anatomical hip center reconstruction were taken as control group, including 7 males and 30 females, aged from 42 to 65 years old with an average of （58.40±4.98） years old, body mass index （BMI） ranged from 18 to 29 kg·m-2 with an average of （23.02±2.21） kg·m-2. Thirty-seven routine high hip center technical reconstruction were performed as study group, including 5 males and 32 females, aged from 41 to 65 years old with an average of （57.31±5.42） years old, BMI ranged from 18 to 29 kg·m-2 with an average of （23.14±2.07） kg·m-2. The patients presented with hip pain, limited function and range of motion, and gait instability before surgery. All patients underwent THA, the control group underwent intraoperative anatomical hip center reconstruction, and the study group underwent intraoperative high hip joint reconstruction. The perioperative indicators of the two groups were compared. The hip joint function, balance function and gait of the patients were evaluated before surgery, 3 months, 6 months, and 12 months after surgery. The length difference of both lower limbs, horizontal distance of rotation center, vertical distance of rotation center and femoral eccentricity were measured before operation and 1 year after operation. The incidence of complications in the two groups during the operation and postoperative follow-up was counted. RESULTS: The operation time of the study group was shorter than that of the control group, and the intraoperative blood loss was less than that of the control group （P<0.05）. After 12-months follow-up, 1 was lost to followvup in study group and 2 were lost to follow-up in control group. The Harris scores and Berg balance scale（BBS）, pace, stride frequency and single step length in the study group were higher than those in the control group at 3 months and 6 months after operation （P<0.05）；there was no statistically significant difference between the two groups in the indexes 12 months after operation （P>0.05）. The vertical distance of the center of rotation of the study group was greater than that of the control group 12 months after operation （P<0.05）, and there was no significant difference in the length difference of the lower limbs, the horizontal distance of the center of rotation, and the femoral eccentricity between two groups （P>0.05）. There were no complications in either group. CONCLUSION: The long-term effects of THA in patients with DDH and severe HOA were similar between the two central hip reconstruction methods, and the safety was good, and the high hip central reconstruction technique could shorten the operation time and reduce the amount of intraoperative blood loss.At the same time, it has certain advantages in early recovery of hip joint function, balance function and walking function of patients.

Real-world treatment patterns and outcomes for patients with advanced hepatocellular carcinoma initially treated with PD-1 inhibitors.

BACKGROUND: Programmed cell death protein-1 (PD-1) inhibitors have shown promising clinical efficacy in treating advanced hepatocellular carcinoma (HCC). However, little evidence exists regarding their treatment patterns and outcomes in real-world practice in China. This study aimed to investigate real-world treatment patterns and outcomes of PD-1 inhibitors as first-line therapies for patients with advanced HCC in China. METHODS: The study population included adult patients with advanced HCC who were initially treated with PD-1 inhibitors from April 2020 to November 2022 in China. Descriptive statistics were used to report first-line treatment patterns and associations between patient characteristics and the most frequently used treatment patterns. The effectiveness of first-line treatment with PD-1 inhibitors was also evaluated according to survival and tumor response. RESULTS: The analyses enrolled 480 patients. The four most frequently used first-line treatment patterns of camrelizumab, tislelizumab, camrelizumab + TACE, and tislelizumab + TACE showed statistical differences in patient characteristics of gender, HBV infection, liver cirrhosis, BCLC stage, and portal vein tumor thrombus (all P < 0.05). However, there was no significant difference in median progression-free survival among the first-line treatments of tislelizumab, camrelizumab, and tislelizumab + TACE (not reached vs. 4.4 months vs. 3.6 months, P = 0.5178). The three groups had similar objective response rates (25.0 % vs. 28.6 % vs. 28.6 %, P = 0.927), and disease control rates (73.1 % vs. 78.6 % vs. 64.3 %, P = 0.573) with no statistical significance. CONCLUSIONS: Our findings provided insights into potential therapeutic strategies of PD-1 inhibitors in first-line settings for advanced HCC in real-world practice in China. It was recommended to consider patient characteristics associated with therapeutic options when making clinical decisions. Prospective randomized controlled studies with larger sample sizes and longer follow-up times were warranted further to verify the potential clinical benefits of PD-1 inhibitors.

Tunable double notch filter on a thin-film lithium niobate platform.

Tunable optical filters at the chip scale play a crucial role in fulfilling the need for reconfigurability in channel routing, optical switching, and wavelength division multiplexing systems. In this Letter, we propose a tunable double notch filter on thin-film lithium niobate using dual microring architecture. This unique integrated filter is essential for complex photonic integrated circuits, along with multiple channels and various frequency spacing. With only one loaded voltage, the device demonstrates a wide frequency spacing tunability from 16.1 to 89.9 GHz by reversely tuning the resonances of the two microrings while the center wavelength between the two resonances remains unaltered. Moreover, by utilizing the pronounced electro-optic properties of lithium niobate associated with the tight light confined nanophotonic waveguides, the device demonstrates a spacing tunability of 0.82 GHz/V and a contrast of 10-16 dB. In addition, the device has an ultracompact footprint of 0.0248 mm2.

Multiple cancer cell types release LIF and Gal3 to hijack neural signals.

Neural signals can significantly influence cancer prognosis. However, how cancer cells may proactively modulate the nervous system to benefit their own survival is incompletely understood. In this study, we report an overlapping pattern of brain responses, including that in the paraventricular nucleus of the hypothalamus, in multiple mouse models of peripheral cancers. A multi-omic screening then identifies leukemia inhibitory factor (LIF) and galectin-3 (Gal3) as the key cytokines released by these cancer cell types to trigger brain activation. Importantly, increased plasma levels of these two cytokines are observed in patients with different cancers. We further demonstrate that pharmacologic or genetic blockage of cancer cell-derived LIF or Gal3 signaling abolishes the brain responses and strongly inhibits tumor growth. In addition, ablation of peripheral sympathetic actions can similarly restore antitumor immunity. These results have elucidated a novel, shared mechanism of multiple cancer cell types hijacking the nervous system to promote tumor progression.

Corrigendum: OPN promotes pro-inflammatory cytokine expression via ERK/JNK pathway and M1 macrophage polarization in Rosacea.

[This corrects the article DOI: 10.3389/fimmu.2023.1285951.].

Recombinant Acetylcholine Receptor Immunization Induces a Robust Model of Experimental Autoimmune Myasthenia Gravis in Mice.

Myasthenia gravis (MG) is a prototypical autoimmune disease of the neuromuscular junction (NMJ). The study of the underlying pathophysiology has provided novel insights into the interplay of autoantibodies and complement-mediated tissue damage. Experimental autoimmune myasthenia gravis (EAMG) emerged as a valuable animal model, designed to gain further insight and to test novel therapeutic approaches for MG. However, the availability of native acetylcholine receptor (AChR) protein is limited favouring the use of recombinant proteins. To provide a simplified platform for the study of MG, we established a model of EAMG using a recombinant protein containing the immunogenic sequence of AChR in mice. This model recapitulates key features of EAMG, including fatigable muscle weakness, the presence of anti-AChR-antibodies, and engagement of the NMJ by complement and a reduced NMJ density. Further characterization of this model demonstrated a prominent B cell immunopathology supported by T follicular helper cells. Taken together, the herein-presented EAMG model may be a valuable tool for the study of MG pathophysiology and the pre-clinical testing of therapeutic applications.

Moscatilin inhibits vascular calcification by activating IL13RA2-dependent inhibition of STAT3 and attenuating the WNT3/ß-catenin signalling pathway.

INTRODUCTION: Vascular calcification, a devastating vascular complication accompanying atherosclerotic cardiovascular disease and chronic kidney disease, increases the incidence of adverse cardiovascular events and compromises the efficacy of vascular interventions. However, effective therapeutic drugs and treatments to delay or prevent vascular calcification are lacking. OBJECTIVES: This study was designed to test the therapeutic effects and mechanism of Moscatilin (also known as dendrophenol) from Dendrobium huoshanense (an eminent traditional Chinese medicine) in suppressing vascular calcification in vitro, ex vivo and in vivo. METHODS: Male C57BL/6J mice (25-week-old) were subjected to nicotine and vitamin D3 (VD3) treatment to induce vascular calcification. In vitro, we established the cellular model of osteogenesis of human aortic smooth muscle cells (HASMCs) under phosphate conditions. RESULTS: By utilizing an in-house drug screening strategy, we identified Moscatilin as a new naturally-occurring chemical entity to reduce HASMC calcium accumulation. The protective effects of Moscatilin against vascular calcification were verified in cultured HASMCs. Unbiased transcriptional profiling analysis and cellular thermal shift assay suggested that Moscatilin suppresses vascular calcification via binding to interleukin 13 receptor subunit A2 (IL13RA2) and augmenting its expression. Furthermore, IL13RA2 was reduced during HASMC osteogenesis, thus promoting the secretion of inflammatory factors via STAT3. We further validated the participation of Moscatilin-inhibited vascular calcification by the classical WNT/ß-catenin pathway, among which WNT3 played a key role in this process. Moscatilin mitigated the crosstalk between WNT3/ß-catenin and IL13RA2/STAT3 to reduce osteogenic differentiation of HASMCs. CONCLUSION: This study supports the potential of Moscatilin as a new naturally-occurring candidate drug for treating vascular calcification via regulating the IL13RA2/STAT3 and WNT3/ß-catenin signalling pathways.

Unilateral Biplanar Screw-Rod Fixation Technique for the Treatment of Odontoid Fractures in Patients with Atlantoaxial Bone or Vascular Abnormalities.

OBJETIVE: This study aims to introduce the unilateral biplanar screw-rod fixation (UBSF) technique (a hybrid fixation technique: 2 sets of atlantoaxial screws were placed on the same side), which serves as a salvage method for traditional posterior atlantoaxial fixation. To summarize the indications of this technique and to assess its safety, feasibility, and clinical effectiveness in the treatment of odontoid fractures. METHODS: Patients with odontoid fractures were enrolled according to special criteria. Surgical duration and intraoperative blood loss were documented. Patients were followed up for a minimum of 12 months. X-ray and computerized tomography scans were conducted and reviewed at 1 day, and patients were asked to return for computerized tomography reviews at 3, 6, 9, and 12 months after surgery until fracture union. Recorded and compared the Neck Visual Analog Scale and Neck Disability Index presurgery and at 1 week and 12 months postsurgery. RESULTS: Between January 2016 and December 2022, our study enrolled 7 patients who were diagnosed with odontoid fractures accompanied by atlantoaxial bone or vascular abnormalities. All 7 patients underwent successful UBSF surgery, and no neurovascular injuries were recorded during surgery. Fracture union was observed in all patients, and the Neck Visual Analog Scale and Neck Disability Index scores improved significantly at 1 week and 12 months postoperative (P < 0.01). CONCLUSIONS: The UBSF technique has been demonstrated to be safe, feasible, and effective in treating odontoid fractures. In cases where the atlantoaxial bone or vascular structure exhibits abnormalities, it can function as a supplementary or alternative approach to the conventional posterior C1-2 fixation.

Heterojunction tunnelled vanadium-based cathode materials for high-performance aqueous zinc ion batteries.

Rechargeable aqueous zinc ion batteries (ZIBs) have emerged as a promising alternative to lithium-ion batteries due to their inherent safety, abundant availability, environmental friendliness and cost-effectiveness. However, the cathodes in ZIBs encounter challenges such as structural instability, low capacity, and sluggish kinetics. In this study, we constructed BiVO4@VO2 (BVO@VO) heterojunction cathode material with bismuth vanadate and vanadium dioxide phases for ZIBs, which demonstrate significant advancements in both aqueous and quasi-solid-state ZIBs. Benefitting from the heterojunction structure, the materials present a high capacity of 262 mAh g-1 at 0.1 A g-1, superb cyclic stability with 96% capacity retention after 1000 cycles at 2 A g-1, and outstanding rate property with a specific capacity of 218 mAh g-1 even at a high rate of 5.0 A g-1. Furthermore, the flexible quasi-solid-state ZIBs incorporating the BVO@VO cathode demonstrate prolonged cyclic life performance with a remarkable specific capacity of 234 mAh g-1 over 100 cycles at a current density of 0.1 A g-1. This study potentially paves the way for the utilization of heterointerface-enhanced zinc ion diffusion for vanadium-based materials in ZIBs, thereby providing a new approach for the design and investigation of high-performance zinc-ion systems.

Accessing Benzoazepine Derivatives via Photoinduced Radical Relay Formal [5 + 2] Reaction of Amide/Alkyne Enabled by Palladium Catalysis.

A novel class of alkyne-tethered amides facilitates an unprecedented photoinduced palladium-catalyzed radical relay formal [5 + 2] reaction. This innovative strategy allows for the rapid construction of diverse fused benzoazepine structures, yielding structurally novel and compelling compounds. With a broad substrate scope and excellent functional group tolerance, the methodology synthesizes biologically active compounds. Notably, the resulting tricyclic benzo[b]azepines offer diversification opportunities through simple transformations. DFT calculations elucidate a seven-membered ring closure mechanism involving the alkenyl radical and Pd(I) rebound alongside a concerted metalation-deprotonation (CMD) process.

Synthesis of bioactive evodiamine and rutaecarpine analogues under ball milling conditions.

Mechanochemical reactions achieved by processes such as milling and grinding are promising alternatives to traditional solution-based chemistry. This approach not only eliminates the need for large amounts of solvents, thereby reducing waste generation, but also finds applications in chemical and materials synthesis. The focus of this study is on the synthesis of quinazolinone derivatives by ball milling, in particular evodiamine and rutaecarpine analogues. These compounds are of interest due to their diverse bioactivities, including potential anticancer properties. The study examines the reactions carried out under ball milling conditions, emphasizing their efficiency in terms of shorter reaction times and reduced environmental impact compared to conventional methods. The ball milling reaction of evodiamine and rutaecarpine analogues resulted in yields of 63-78% and 22-61%, respectively. In addition, these compounds were tested for their cytotoxic activity, and evodiamine exhibited an IC50 of 0.75 ± 0.04 µg mL-1 against the Ca9-22 cell line. At its core, this research represents a new means to synthesise these compounds, providing a more environmentally friendly and sustainable alternative to traditional approaches.

2-Hydroxy-5-nitro-3-(trifluoromethyl)pyridine as a Novel Matrix for Enhanced MALDI Imaging of Tissue Metabolites.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), which is a label-free imaging technique, determines the spatial distribution and relative abundance of versatile endogenous metabolites in tissues. Meanwhile, matrix selection is generally regarded as a pivotal step in MALDI tissue imaging. This study presents the first report of a novel MALDI matrix, 2-hydroxy-5-nitro-3-(trifluoromethyl)pyridine (HNTP), for the in situ detection and imaging of endogenous metabolites in rat liver and brain tissues by MALDI-MS in positive-ion mode. The HNTP matrix exhibits excellent characteristics, including strong ultraviolet absorption, µm-scale matrix crystals, high chemical stability, low background ion interference, and high metabolite ionization efficiency. Notably, the HNTP matrix also shows superior detection capabilities, successfully showing 185 detectable metabolites in rat liver tissue sections. This outperforms the commonly used matrices of 2,5-dihydroxybenzoic acid and 2-mercaptobenzothiazole, which detect 145 and 120 metabolites from the rat liver, respectively. Furthermore, a total of 152 metabolites are effectively detected and imaged in rat brain tissue using the HNTP matrix, and the spatial distribution of these compounds clearly shows the heterogeneity of the rat brain. The results demonstrate that HNTP is a new and powerful positive-ion mode matrix to enhance the analysis of metabolites in biological tissues by MALDI-MSI.

Quantitative differentiation of toxicity contributions and predicted global risk of fipronil and its transformation products to aquatic invertebrates.

Biotransformation often alters chemical toxicity, yet its impacts on risk assessment are hardly quantified due to the challenges in acquiring internal exposure-based thresholds for chemicals that are readily metabolizable. Here, we integrated toxic unit and toxicokinetics to quantitatively assess toxicity contributions and potential risk of both parent compound and transformation products (TPs) to aquatic organisms, using fipronil (FIP) as a representative toxicant. In aquatic invertebrates Chironomus dilutus and Hyalella azteca, approximately 90 % of FIP was transformed to fipronil sulfone (SUL). FIP and SUL exhibited similar intrinsic toxicity to these organisms, which was contrary to conventional perception that SUL was more toxic than FIP. However, biotransformation was still important in risk assessment because the TP had 10-fold slower depuration rate than FIP. The amphipod H. azteca was found to be as sensitive to FIPs as the insect C. dilutus, which was previously considered ten times more sensitive based on external thresholds. This discrepancy has led to overlooking the toxicity of FIP to H. azteca in regional risk assessments. Lastly, we predicted the lethal risk of FIPs in global surface water. When using external thresholds for prediction, FIPs in 3.4 % of the water samples were lethally toxic to H. azteca, and the percentage of water samples at risk increased to 14 % when internal thresholds were used and SUF dominated the risk. This study presents an improved method for quantifying aquatic risk of readily metabolized toxicants. Our findings underscore the urgency of considering TPs in water quality assessments, especially for sensitive species that are at risk in the environment.

V-type granular starches prepared by maize starches with different amylose contents: An investigation in structure, physicochemical properties and digestibility.

V-type granular starches (VGSs) were prepared via an ethanol-alkaline (EA) method using maize starch with different amylose contents, specifically, high amylose (HAM), normal maize starch (MS), and waxy maize starch (WS). The X-ray diffraction pattern of the native starch was completely transformed into a V-type pattern after the EA treatment, indicating a structural change in the starch granules. The VGSs prepared by HAM had highest relative crystallinity (31.8°), while the VGSs prepared by WS showed amorphous diffraction pattern. Excessive NaOH, however, would disrupt the formation of V-type structures and cause granular shape rupture. The quantity of double-helical structures, particularly those formed by amylopectin at the starch granules' periphery, significantly decreased. Conversely, single-helical structures formed by amylose increased. A notable rise in the relative crystallinity of V crystals. Four VGS samples, characterized by granular integrity, were chosen for the next investigation of physicochemical and digestive properties. VGS prepared from HAM exhibited higher granular integrity, lower cold-water swelling extent (59.0 and 161.0 cP), improved thermal stability (the value of breakdown as lower as 57.67 and 186.67 cP), and higher resistance to digestion (RS content was up to 10.38 % and 9.00 % higher than 5.86 % and 5.66 % of VGS prepared from WS and MS). The results confirmed that amylose content has a substantial impact on the microstructural and physicochemical properties of VGSs.