Influence on the temporomandibular joint induced by mandibular malpositioning caused by vertical dimension elevation and occlusal loss in adult rats: An imaging, histological and immunohistochemical study.

BACKGROUND: Mandibular malpositioning may result in an abnormal concentration of stresses within the temporomandibular joint (TMJ) in adult rats, which may further lead to a series of pathological changes, such as articular cartilage wear, subchondral bone sclerosis and osteophyte formation. However, the pathological and adaptive changes in condylar cartilage caused by different stress distributions are still controversial. OBJECTIVE: The aim of this study was to observe the effect of sagittal changes in mandibular position on condylar cartilage by changing the occlusal vertical dimension (OVD) in adult rats. METHODS: Fifteen-week-old female rats were divided into three groups: control (CON), increased OVD (iOVD) and loss of occlusion (LO) groups. An occlusal plate and tooth extraction were used to establish the animal model. TMJ samples of the experimental and CON groups were observed and investigated by bone morphological, histomorphological and immunohistochemical staining analyses at 3 days, 1 week, 2 weeks, 4 weeks and 8 weeks. Weight curves were plotted. RESULTS: Micro-computed tomography showed that, compared with the CON group, cartilage destruction followed by repair occurred in both experimental groups, which was similar to the trend observed in haematoxylin-eosin staining. All experimental results for the iOVD group showed an approximately similar time trend. Compared with the iOVD group, the toluidine blue and immunohistochemical staining results in the LO group showed no obvious change trend over time. CONCLUSION: Compared with occlusal loss, an increase in OVD caused faster and more severe damage to condylar cartilage, and subchondral bone repair occurred later.

Potential coupling of microbial methane, nitrogen, and sulphur cycling in the Okinawa Trough cold seep sediments.

The Okinawa Trough (OT) is a back-arc basin with a wide distribution of active cold seep systems. However, our understanding of the metabolic function of microbial communities in the cold seep sediments of the OT remains limited. In this study, we investigated the vertical profiles of functional genes involved in methane, nitrogen, and sulphur cycling in the cold seep sediments of the OT. Furthermore, we explored the possible coupling mechanisms between these biogeochemical cycles. The study revealed that the majority of genes associated with the nitrogen and sulphur cycles were most abundant in the surface sediment layers. However, only the key genes responsible for sulphur disproportionation (sor), nitrogen fixation (nifDKH), and methane metabolism (mcrABG) were more prevalent within sulfate-methane transition zone (SMTZ). Significant positive correlations (P < 0.05) were observed between functional genes involved in sulphur oxidation, thiosulphate disproportionation with denitrification, and dissimilatory nitrate reduction to ammonium (DNRA), as well as between AOM/methanogenesis and nitrogen fixation, and between sulphur disproportionation and AOM. A genome of Filomicrobium (class Alphaproteobacteria) has demonstrated potential in chemoautotrophic activities, particularly in coupling DNRA and denitrification with sulphur oxidation. Additionally, the characterized sulfate reducers such as Syntrophobacterales have been found to be capable of utilizing nitrate as an electron acceptor. The predominant methanogenic/methanotrophic groups in the OT sediments were identified as H2-dependent methylotrophic methanogens (Methanomassiliicoccales and Methanofastidiosales) and ANME-1a. This study offered a thorough understanding of microbial ecosystems in the OT cold seep sediments, emphasizing their contribution to nutrient cycling.IMPORTANCEThe Okinawa Trough (OT) is a back-arc basin formed by extension within the continental lithosphere behind the Ryukyu Trench arc system. Cold seeps are widespread in the OT. While some studies have explored microbial communities in OT cold seep sediments, their metabolic potential remains largely unknown. In this study, we used metagenomic analysis to enhance comprehension of the microbial community's role in nutrient cycling and proposed hypotheses on the coupling process and mechanisms involved in biogeochemical cycles. It was revealed that multiple metabolic pathways can be performed by a single organism or microbes that interact with each other to carry out various biogeochemical cycling. This data set provided a genomic road map on microbial nutrient cycling in OT sediment microbial communities.

A novel gene-based model for prognosis prediction of head and neck squamous cell carcinoma.

Background: Head and neck squamous cell carcinoma (HNSCC) is a significant global health challenge. The identification of reliable prognostic biomarkers and construction of an accurate prognostic model are crucial. Methods: In this study, mRNA expression data and clinical data of HNSCC patients from The Cancer Genome Atlas were used. Overlapping candidate genes (OCGs) were identified by intersecting differentially expressed genes and prognosis-related genes. Best prognostic genes were selected using the least absolute shrinkage and selection operator Cox regression based on OCGs, and a risk score was developed using the Cox coefficient of each gene. The prognostic power of the risk score was assessed using Kaplan-Meier survival analysis and time-dependent receiver operating characteristic analysis. Univariate and multivariate Cox regression were performed to identify independent prognostic parameters, which were used to construct a nomogram. The predictive accuracy of the nomogram was evaluated using calibration plots. Functional enrichment analysis of risk score related genes was performed to explore the potential biological functions and pathways. External validation was conducted using data from the Gene Expression Omnibus and ArrayExpress databases. Results: FADS3, TNFRSF12A, TJP3, and FUT6 were screened to be significantly related to prognosis in HNSCC patients. The risk score effectively stratified patients into high-risk group with poor overall survival (OS) and low-risk group with better OS. Risk score, age, clinical M stage and clinical N stage were regarded as independent prognostic parameters by Cox regression analysis and used to construct a nomogram. The nomogram performed well in 1-, 2-, 3-, 5- and 10-year survival predictions. Functional enrichment analysis suggested that tight junction was closely related to the cancer. In addition, the prognostic power of the risk score was validated by external datasets. Conclusions: This study constructed a gene-based model integrating clinical prognostic parameters to accurately predict prognosis in HNSCC patients.

[Highly polar chemical constituents from whole herb of Scindapsus officinalis].

Macroporous resin column chromatography, MCI medium pressure column chromatography, and semi-preparative high performance liquid chromatography were employed to isolate the chemical components from the aqueous extract of the whole herb of Scindapsus officinalis. The structures of the compounds were identified based on the physical and chemical properties and the spectroscopic data. Ten compounds were isolated from the aqueous extract and identified as 3,4-dihydroxyphenylethyl-8-O-[ß-D-apiofuranosyl-(1→4)]-ß-D-glucopyranoside(1), alternamide B(2), 3,4-dihydroxyphenylethyl-O-ß-D-glucopyranoside(3), 1-(4-hydroxy)-phenylethyl-ß-D-galactopyranoside(4), 3,4-dihydroxyphenylethyl-8-O-[ß-D-apiofuranosyl-(1→2)]-ß-D-glucopyranoside(5), hydroxytyrosol-4-O-ß-D-glucopyranoside(6), 3,5-dihydroxyphenylethyl-3-O-ß-D-glucopyranoside(7), salidroside(8), dihydroisoquinolone(9), and 4-methoxybenzenepropanol-3-O-ß-D-glucopyranoside(10). Among them, compound 1 was a new one, and compounds 2-10 were obtained from S. officinalis for the first time. The RAW264.7 cells were exposed to lipopolysaccharide for the mode-ling of inflammation, and the cells were then used to examine anti-inflammatory activities of the compounds. The results showed that compounds 6 and 7 had strong anti-inflammatory activities, while compounds 1, 2, and 5 had moderate anti-inflammatory activities.

Comparison of the outcomes of concurrent versus staged TAVR combined with PCI in patients with severe aortic stenosis and coronary artery disease: a systematic review and meta-analysis.

BACKGROUND: The optimal timing for percutaneous coronary intervention (PCI) in patients undergoing transcatheter aortic valve replacement (TAVR) remains uncertain. This research aims to evaluate the results of patients diagnosed with severe aortic valve stenosis and coronary artery disease who undergo either simultaneous or staged PCI therapy during TAVR procedures. METHODS: We retrieved all relevant studies from our self-constructed databases up to January 2, 2024, encompassing databases such as Embase, Medline, Cochrane Library, and PubMed. RESULTS: A total of nine studies were included, and the results showed that both surgical modalities had good safety profiles in the early and long-term stages. For early endpoint events, the risk of all-cause mortality and major bleeding within 30 years was similar in the staged TAVR + PCI and the contemporaneous TAVR + PCI (P > 0.05). Additionally, the risk of myocardial infarction, stroke, acute kidney injury and pacemaker implantation within 30 days or perioperatively is similar (P > 0.05). For long-term endpoint events, the risk of all-cause mortality, myocardial infarction and stroke was similar in the two groups at ≥2 years (P > 0.05). CONCLUSION: In patients undergoing TAVR who required coronary revascularization, no significant differences were observed in the early and long-term outcomes between those receiving concurrent TAVR and PCI versus staged surgery.

External Electrons Directly Stimulate Escherichia coli for Enhancing Biological Hydrogen Production.

External electric field has the potential to influence metabolic processes such as biological hydrogen production in microorganisms. Based on this concept, we designed and constructed an electroactive hybrid system for microbial biohydrogen production under an electric field comprised of polydopamine (PDA)-modified Escherichia coli (E. coli) and Ni foam (NF). In this system, electrons generated from NF directly migrate into E. coli cells to promote highly efficient biocatalytic hydrogen production. Compared to that generated in the absence of electric field stimulation, biohydrogen production by the PDA-modified E. coli-based system is significantly enhanced. This investigation has demonstrated the mechanism for electron transfer in a biohybrid system and gives insight into precise basis for the enhancement of hydrogen production by using the multifield coupling technology.

Fine-scale mapping of chromosome 9q22.33 identifies candidate causal variant in ovarian cancer.

Ovarian cancer is a complex polygenic disease in which genetic factors play a significant role in disease etiology. A genome-wide association study (GWAS) identified a novel variant on chromosome 9q22.33 as a susceptibility locus for epithelial ovarian cancer (EOC) in the Han Chinese population. However, the underlying mechanism of this genomic region remained unknown. In this study, we conducted a fine-mapping analysis of 130 kb regions, including 1,039 variants in 200 healthy women. Ten variants were selected to evaluate the association with EOC risk in 1,099 EOC cases and 1,591 controls. We identified two variants that were significantly associated with ovarian cancer risk (rs7027650, P = 1.91 × 10-7; rs1889268, P = 3.71 × 10-2). Expression quantitative trait locus (eQTL) analysis found that rs7027650 was significantly correlated with COL15A1 gene expression (P = 0.009). The Luciferase reporter gene assay confirmed that rs7027650 could interact with the promoter region of COL15A1, reducing its activity. An electrophoretic mobility shift assay (EMSA) showed the allele-specific binding capacity of rs7027650. These findings revealed that rs7027650 could be a potential causal variant at 9q22.33 region and may regulate the expression level of COL15A1. This study offered insight into the molecular mechanism behind a potential causal variant that affects the risk of ovarian cancer.

Identification of different degrees of processed ginger using GC-IMS combined with machine learning.

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An elevated urinary albumin-to-creatinine ratio increases the risk of incident cardia-cerebrovascular disease in individuals with type 2 diabetes.

AIMS: We aimed to explore the associations between urine albumin-to-creatinine ratio (uACR) and cardia-cerebrovascular disease (CVD) in Chinese population with type 2 diabetes(T2D). METHODS: We included 8975 participants with T2D but free of prevalent CVD (including myocardial infarction, ischemic and hemorrhagic stroke) at baseline from Kailuan study who were assessed with uACR between 2014 and 2016. The participants were divided into three groups based on their baseline uACR: normal (< 3 mg/mmol), microalbuminuria (3-30 mg/mmol), and macroalbuminuria (≥ 30 mg/mmol). Cox regression models and restricted cubic spline were used to evaluate the hazard ratios (HRs) and 95% confidence intervals (CIs) of incident CVD. The area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to see if incorporating uACR into existing models could improve performance. RESULTS: During a median follow-up of 4.05 years, 560 participants developed first CVD event (6.24%). After adjustment for potential confounders, participants with microalbuminuria had higher risks of CVD compared with normal uACR, with HRs of 1.57(95% CI 1.04-2.37) for myocardial infarction, 1.24(95% CI 1.00-1.54) for ischemic stroke,1.62(95% CI 0.73-3.61) for hemorrhagic stroke, and 1.30(95% CI 1.07-1.57) for total CVD. The risks gradually attenuated with uACR increase, with HRs of 2.86(95% CI 1.63-5.00) for myocardial infarction, 2.46(95% CI 1.83-3.30) for ischemic stroke, 4.69(95% CI 1.72-12.78) for hemorrhagic stroke, and 2.42(95% CI 1.85-3.15) for total CVD in macroalbuminuria. The addition of uACR to established CVD risk models improved the CVD risk prediction efficacy. CONCLUSIONS: Increasing uACR, even below the normal range, is an independent risk factor for new-onset CVD in T2D population. Furthermore, uACR could improve the risk prediction for CVD among community based T2D patients.

Spiky Artificial Peroxidases with V-O-Fe Pair Sites for Combating Antibiotic-Resistant Pathogens.

With the sharp rise of antibiotic-resistant pathogens worldwide, it is of enormous importance to create new strategies for combating pathogenic bacteria. Here, we create an iron oxide-based spiky artificial peroxidase (POD) with V-O-Fe pair sites (V-Fe2 O3 ) for combating methicillin-resistant Staphylococcus aureus (MRSA). The experimental studies and theoretical calculations demonstrate that the V-Fe2 O3 can achieve the localized "capture and killing" bifunction from the spiky morphology and massive reactive oxygen species (ROS) production. The V-Fe2 O3 can reach nearly 100 % bacterial inhibition over a long period by efficiently oxidizing the lipid membrane. Our wound disinfection results identify that the V-Fe2 O3 can not only efficiently eliminate MRSA and their biofilm but also accelerate wound recovery without causing noticeable inflammation and toxicity. This work offers essential insights into the critical roles of V-O-Fe pair sites and localized "capture and killing" in biocatalytic disinfection and provides a promising pathway for the de novo design of efficient artificial peroxidases.

Nitrided Rhodium Nanoclusters with Optimized Water Bonding and Splitting Effects for pH-Universal H2-Production.

The nitridation of noble metals-based catalysts to further enhance their hydrogen evolution reaction (HER) kinetics in neutral and alkaline conditions would be an effective strategy for developing high-performance wide pH HER catalysts. Herein, a facile molten urea method is employed to construct the nitrided Rh nanoclusters (RhxN) supported on N-doped carbon (RhxN-NC). The uniformly distributed RhxN clusters exhibited optimized water bonding and splitting effects, therefore resulting in excellent pH-universal HER performance. The optimized RhxN-NC catalyst only requires 8, 12, and 109 mV overpotentials to reach the current density of 10 mA cm-2 in 0.5 M H2SO4, 1.0 M KOH, and 1.0 M PBS electrolytes, respectively. The spectroscopic characterizations and theoretical calculation further confirm the vital role of Rh-N moieties in RhxN clusters in improving the transfer of electrons and facilitating the generation of H2. This work not only provides a suitable nitridation method for noble metal species in mild conditions but also makes a breakthrough in synthesizing noble metal nitrides-based electrocatalysts to achieve an exceptional wide-pH HER performance and other catalysis.

Engineering Zinc-Organic Frameworks-Based Artificial Carbonic Anhydrase with Ultrafast Biomimetic Centers for Efficient Hydration Reactions.

Constructing effective and robust biocatalysts with carbonic anhydrase (CA)-mimetic activities offers an alternative and promising pathway for diverse CO2-related catalytic applications. However, there is very limited success has been achieved in controllably synthesizing CA-mimetic biocatalysts. Here, inspired by the 3D coordination environments of CAs, this study reports on the design of an ultrafast ZnN3-OH2 center via tuning the 3D coordination structures and mesoporous defects in a zinc-dipyrazolate framework to serve as new, efficient, and robust CA-mimetic biocatalysts (CABs) to catalyze the hydration reactions. Owing to the structural advantages and high similarity with the active center of natural CAs, the double-walled CAB with mesoporous defects displays superior CA-like reaction kinetics in p-NPA hydrolysis (V0 = 445.16 nM s-1, Vmax = 3.83 µM s-1, turnover number: 5.97 × 10-3 s-1), which surpasses the by-far-reported metal-organic frameworks-based biocatalysts. This work offers essential guidance in tuning 3D coordination environments in artificial enzymes and proposes a new strategy to create high-performance CA-mimetic biocatalysts for broad applications, such as CO2 hydration/capture, CO2 sensing, and abundant hydrolytic reactions.

A Biomimetic Upconversion Nanobait-Based Near Infrared Light Guided Photodynamic Therapy Alleviates Alzheimer's Disease by Inhibiting ß-Amyloid Aggregation.

Aberrant ß-amyloid (Aß) fibrillation is the key event in Alzheimer's disease (AD), the inhibition and degradation of which are recognized as a promising therapeutic strategy to alleviate the nerve damage of AD. Photodynamic therapy (PDT) holds great potential for modulation of Aß self-assembly, which is nevertheless limited by the inefficient utilization of reactive oxygen species (ROS). Herein, an erythrocyte membrane (EM)-modified core-shell upconversion nanoparticle (UCNP/Cur@EM) is designed and fabricated as a biomimetic nanobait to improve the PDT efficiency in AD. The UCNP with the outlayer of mesoporous silica is synthesized to load a high amount of the photosensitizer (curcumin), the unique optical feature of which can trigger curcumin to generate ROS upon near-infrared light (NIR) irradiation. Integration of EM enables the biomimetic nanobait to attract Aß peptides trapped in the phospholipid bilayer, restraining the growth of Aß monomers to form aggregates and improving the utilization rate of ROS to degrade the preformed Aß aggregates. In vivo studies demonstrate that UCNP/Cur@EM irradiated by NIR enables to decrease Aß deposits, ameliorates memory deficits, and rescues cognitive functions in the APP/PS1 transgenic mouse model. A biocompatible and controllable way is provided here to inhibit the amyloid protein-associated pathological process of AD.

Molecular mechanism of α-Hederin in tumor progression.

α-Hederin is a monosaccharide pentacyclic triterpene saponin compound derived from the Chinese herb, Pulsatilla. It has garnered considerable attention for its anti-tumor, anti-inflammatory, and spasmolytic pharmacological activities. Given the rising incidence of cancer and the pronounced adverse reactions associated with chemotherapy drugs-which profoundly impact the quality of life for cancer patients-there is an immediate need for safe and effective antitumor agents. Traditional drugs and their anticancer effects have become a focal point of research in recent years. Studies indicate that α-Hederin can hinder tumor cell proliferation and impede the advancement of various cancers, including breast, lung, colorectal, and liver cancers. The principal mechanism behind its anti-tumor activity involves inhibiting tumor cell proliferation, facilitating tumor cell apoptosis, and arresting the cell cycle process. Current evidence suggests that α-Hederin can exert its anti-tumor properties through diverse mechanisms, positioning it as a promising agent in anti-tumor therapy. However, a comprehensive literature search revealed a gap in the comprehensive understanding of α-Hederin. This paper aims to review the available literature on the anti-tumor mechanisms of α-Hederin, hoping to provide valuable insights for the clinical treatment of malignant tumors and the innovation of novel anti-tumor medications.

Pro-carcinogenic actions of miR-155/FOXO3a in colorectal cancer development.

Colorectal cancer (CRC) ranks third in cancer incidence and second in cancer mortality globally. MicroRNAs (miRNAs) are promising biomarkers and therapeutic targets for CRC diagnosis and treatment. The miR-155 is reported to induce radiation resistance in CRC. In this study, we aimed to further clarify the role and underlying mechanism of the miR-155 in CRC cell malignancy. We found that miR-155 was significantly up-regulated in CRC tissues. The results of loss-of-function experiments revealed that miR-155 deficiency suppressed the proliferative capacity, invasion, and migration of CRC cells. Moreover, the downstream target genes of miR-155 were screened, and miR-155 was demonstrated to directly bind to FOXO3a in CRC cells to negatively regulate FOXO3a expression. FOXO3a was downregulated in CRC tissues and the expression of FOXO3a and miR-155 was in negative correlation in CRC tissues. FOXO3a overexpression alone was revealed to inhibit CRC cell growth, migration and invasion. Additionally, rescue assays showed that FOXO3a silencing significantly reversed the inhibitory effect of miR-155 deficiency on CRC cell malignant behaviors. In conclusion, miR-155 induces malignant phenotypes of CRC cells including cell proliferation, migration and invasion by targeting FOXO3a, which might provide clues for the targeted therapy of CRC.

Isolation, characterization, trypsin inhibition, liver protective and antioxidant activities of arabinoxylan from Massa Medicata Fermentata and its processed products.

Massa Medicata Fermentata (MMF) is a traditional Chinese medicine widely used in feed additives and human medicine. In this study, two neutral polysaccharides (SMMFP-1 and CMMFP-1) were isolated from two forms of MMF (sheng and chao MMF), and their structural characteristics and bioactivities were studied. The results showed that CMMFP-1 had higher average Mw compared with that of SMMFP-1. SMMFP-1 had a lower proportion of Ara, Xyl, GalA, and GlcA, but higher levels of Fuc, Gal, Man, and GulA. Compared with CMMFP-1, SMMFP-1 had a triple helix structure. SMMFP-1 had a layered structure, whereas CMMFP-1 had a curly layered structure. More glycosidic linkage types were found in SMMFP-1 than in CMMFP-1, and SMMFP-1 had a greater number of side chains. More importantly, SMMFP-1 showed better trypsin inhibition activity in vitro, liver-protective activity in vivo, and stronger antioxidant activity in vivo than CMMFP-1. Thus, arabinoxylans may be one of the active substances for different efficacies between MMF and its processed product. The results of this study facilitate the exploration of the correlation between the structural characteristics and biological functionalities of MMF arabinoxylans. Moreover, a theoretical basis is established for further study of the unique properties of arabinoxylans and their applications.

miR-432-5p Inhibits the Ferroptosis in Cardiomyocytes Induced by Hypoxia/Reoxygenation via Activating Nrf2/SLC7A11 Axis by Degrading Keap1.

Early reperfusion into the myocardium after ischemia causes myocardial ischemia-reperfusion (I/R) injury and ferroptosis was involved. Ischemia activates the expression of a series of oxidative stress genes and their downstream regulatory genes, including ferroptosis-related genes such as nuclear factor E2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and SLC7A11. This study adopted primary cardiomyocytes and I/R in rats to evaluate the ferroptosis and changing of Nrf2-SLC7A11/heme oxygenase-1 (HO-1) in vitro and in vivo. Online analysis tools were used to predict the possible target Kelch-like ECH-associated protein 1 (Keap1) of miR-432-5p. The mimic of miR-432-5p plasmid was constructed to verify the effect of miR-432-5p on ferroptosis. We found that hypoxia/reoxygenation (H/R) in cardiomyocytes and I/R in rats induced lipid peroxidation and ferroptosis in cardiomyocytes. The activation of the Nrf2-SLC7A11/HO-1 pathway protects cardiomyocytes from ferroptosis. Downregulation of miR-432-5p has been confirmed in H/R cardiomyocytes (in vitro) and cardiomyocytes in myocardial infarction rats (in vivo). Upregulation of miR-432-5p inhibited ferroptosis of cardiomyocytes induced by RAS-selective lethal 3 (RSL3), an inhibitor of GPX4 and ferroptosis inducer through decreasing the binding protein of Nrf2, Keap1, which was confirmed by bioinformatics and mutation assay. Knockdown Nrf2 attenuates the protection effect of miR-432-5p on H/R cardiomyocytes. Intravenous delivery of liposome carriers of miR-432-5p remarkably ameliorated cardiomyocyte impairment in the I/R animal model. In conclusion, miR-432-5p inhibits the ferroptosis in cardiomyocytes induced by H/R by activating Nrf2/SLC7A11 axis by degrading Keap1 and is a potential drug target for clinical myocardial infarction treatment.

Copper-containing titanium alloys promote the coupling of osteogenesis and angiogenesis by releasing copper ions.

Previous investigations have reported on the ability of copper (Cu)-bearing biomaterials to accelerate vascular formation and bone regeneration. However, few studies have explored the effects of Cu-bearing materials on the interactions between angiogenesis and osteogenesis. Therefore, in this study, we prepared Cu-containing alloys using selective laser melting (SLM) technology and investigated the impact of preosteoblasts seeded on Ti6Al4V-4.5Cu alloy on angiogenesis. Our results indicated that Ti6Al4V-4.5Cu alloys increased the expression of proangiogenic genes and proteins in preosteoblasts, which further stimulated vascular formation in endothelial cells. Besides, we discovered that the biological effects of the Ti6Al4V-4.5Cu alloy were partly attributed to the release of Cu ions. In short, our research demonstrated the ability of Ti6Al4V-4.5Cu alloys to promote the coupling of angiogenesis and osteogenesis by releasing Cu ions.

Classification of multi-year and multi-variety pumpkin seeds using hyperspectral imaging technology and three-dimensional convolutional neural network.

BACKGROUND: Pumpkin seeds are major oil crops with high nutritional value and high oil content. The collection and identification of different pumpkin germplasm resources play a significant role in the realization of precision breeding and variety improvement. In this research, we collected 75 species of pumpkin from the Zhejiang Province of China. 35,927 near-infrared hyperspectral images of 75 types of pumpkin seeds were used as the research object. RESULTS: To realize the rapid classification of pumpkin seed varieties, position attention embedded three-dimensional convolutional neural network (PA-3DCNN) was designed based on hyperspectral image technology. The experimental results showed that PA-3DCNN had the best classification effect than other classical machine learning technology. The classification accuracy of 99.14% and 95.20% were severally reached on the training and test sets. We also demonstrated that the PA-3DCNN model performed well in next year's classification with fine-tuning and met with 94.8% accuracy. CONCLUSIONS: The model performance improved by introducing double convolution and pooling structure and position attention module. Meanwhile, the generalization performance of the model was verified, which can be adopted for the classification of pumpkin seeds in multiple years. This study provided a new strategy and a feasible technical approach for identifying germplasm resources of pumpkin seeds.

Synchronized triple-wavelength fiber lasers at 1, 1.55, and 1.9†µm.

Synchronized lasers working at different wavelengths are of great significance for numerous applications, such as high-energy femtosecond pulse emission, Raman microscopy, and precise timing distribution. Here, we report synchronized triple-wavelength fiber lasers working at 1, 1.55, and 1.9 µm, respectively, by combining the coupling and injection configurations. The laser system consists of three fiber resonators gained by ytterbium-doped fiber, erbium-doped fiber, and thulium-doped fiber, respectively. Ultrafast optical pulses formed in these resonators are obtained by passive mode-locking with the use of a carbon-nanotube saturable absorber. A maximum cavity mismatch of ∼1.4 mm is reached by the synchronized triple-wavelength fiber lasers in the synchronization regime by finely tuning the variable optical delay lines incorporated in the fiber cavities. In addition, we investigate the synchronization characteristics of a non-polarization-maintaining fiber laser in an injection configuration. Our results provide a new, to the best of our knowledge, perspective on multi-color synchronized ultrafast lasers with broad spectral coverage, high compactness, and a tunable repetition rate.