Initial stomatal conductance increases photosynthetic induction of trees leaves more from sunlit than from shaded environments: A meta-analysis.

It has long been held that tree species/leaves from shaded environments show faster rate of photosynthetic induction than species/leaves from sunlit environments. But the evidence so far is conflicting and the underlying mechanisms are still under debate. To address the debate, we compiled a dataset for 87 tree species and compared the initial increasing slope during the first 2-minute induction (SA) and stomatal and biochemical characteristics between sun and shade species from the same study, and those between sun and shade leaves within the same species. In 77% of between-species comparisons, the species with high steady-state photosynthetic rate in the high light (Af) exhibited a larger SA than the species with low Af. In 67% within-species comparisons, the sun leaves exhibited a larger SA than the shade leaves. However, in only a few instances did the sun species/leaves more rapidly achieve 50% of full induction, with an even smaller SA, than the shade species/leaves. At both the species and leaf level, SA increased with increasing initial stomatal conductance before induction (gsi). Despite exhibiting reduced intrinsic water use efficiency in low light, a large SA proportionally enhances photosynthetic carbon gain during the first 2-minute induction in the sun species and leaves. Thus, in terms of the increase in absolute rate of photosynthesis, tree species/leaves from sunlit environments display faster photosynthetic induction responses than those from shaded environments. Our results call for re-consideration of contrasting photosynthetic strategies in photosynthetic adaption/acclimation to dynamic light environments across species.

The leaf-scale mass-based photosynthetic optimization model better predicts photosynthetic acclimation than the area-based.

Leaf-scale photosynthetic optimization models can quantitatively predict photosynthetic acclimation and have become an important means of improving vegetation and land surface models. Previous models have generally been based on the optimality assumption of maximizing the net photosynthetic assimilation per unit leaf area (i.e. the area-based optimality) while overlooking other optimality assumptions such as maximizing the net photosynthetic assimilation per unit leaf dry mass (i.e. the mass-based optimality). This paper compares the predicted results of photosynthetic acclimation to different environmental conditions between the area-based optimality and the mass-based optimality models. The predictions are then verified using the observational data from the literatures. The mass-based optimality model better predicted photosynthetic acclimation to growth light intensity, air temperature and CO2 concentration, and captured more variability in photosynthetic traits than the area-based optimality models. The findings suggest that the mass-based optimality approach may be a promising strategy for improving the predictive power and accuracy of optimization models, which have been widely used in various studies related to plant carbon issues.

Targeting Hypoxia and Autophagy Inhibition via Delivering Sonodynamic Nanoparticles With HIF-2α Inhibitor for Enhancing Immunotherapy in Renal Cell Carcinoma.

Immune checkpoint blockers (ICBs) therapy stands as the first-line treatment option for advanced renal cell carcinoma (RCC). However, its effectiveness is hindered by the immunosuppressive tumor microenvironment (TME). Sonodynamic therapy (SDT) generates tumor cell fragments that can prime the host's antitumor immunity. Nevertheless, the hypoxic microenvironment and upregulated autophagy following SDT often lead to cancer cell resistance. In response to these challenges, a hypoxia-responsive polymer (Poly(4,4'-azobisbenzenemethanol-PMDA)-mPEG5k, P-APm) encapsulating both a HIF-2α inhibitor (belzutifan) and the ultrasonic sensitize (Chlorin e6, Ce6) is designed, to create the nanoparticle APm/Ce6/HIF. APm/Ce6/HIF combined with ultrasound (US) significantly suppresses tumor growth and activates antitumor immunity in vivo. Moreover, this treatment effectively transforms the immunosuppressive microenvironment from "immune-cold" to "immune-hot", thereby enhancing the response to ICBs therapy. The findings indicate that APm/Ce6/HIF offers a synergistic approach combining targeted therapy with immunotherapy, providing new possibilities for treating RCC.

Effect of Phase Structure on the Viscoelasticity and Mechanical Properties of Isotactic Polypropylene Multicomponents Polymerized with Non-Conjugated α,ω-Diene.

Increasing of rubber content in isotactic polypropylene/ethylene-propylene rubber (iPP/EPR) alloys can extend the applications of this kind of polyolefin. The EPR content and phase structure of isotactic polypropylene multicomponents have great effect on the viscoelasticity and mechanical properties. iPP/EPR in-reactor alloys with a high EPR content were obtained through the in situ crosslinking of EPR chains with α,ω-diene. The morphological observation results indicate that the crosslinked iPP/EPR in-reactor alloys have a good spherical shape with clean and rough external surfaces. The high EPR content is finely dispersed in the crosslinked iPP/EPR alloys in areas ranging in size from tens of nanometers to several micrometers, which implies that a sufficient crosslinking degree of EPR chains can effectively prevent their aggregation and restrict macro-phase separation. The rheological results show a clear plateau in the terminal region, which reveals an entangled polymer chain network in the crosslinked iPP/EPR alloys. The well-dispersed EPR and the bi-continuous phase structure have a great effect on the mechanical properties of the isotactic polypropylene multicomponent which were assessed.

Targeting senescent cells in aging and COVID-19: from cellular mechanisms to therapeutic opportunities.

The COVID-19 pandemic has caused a global health crisis and significant social economic burden. While most individuals experience mild or non-specific symptoms, elderly individuals are at a higher risk of developing severe symptoms and life-threatening complications. Exploring the key factors associated with clinical severity highlights that key characteristics of aging, such as cellular senescence, immune dysregulation, metabolic alterations, and impaired regenerative potential, contribute to disruption of tissue homeostasis of the lung and worse clinical outcome. Senolytic and senomorphic drugs, which are anti-aging treatments designed to eliminate senescent cells or decrease the associated phenotypes, have shown promise in alleviating age-related dysfunctions and offer a novel approach to treating diseases that share certain aspects of underlying mechanisms with aging, including COVID-19. This review summarizes the current understanding of aging in COVID-19 progression, and highlights recent findings on anti-aging drugs that could be repurposed for COVID-19 treatment to complement existing therapies.

Interplay between metavalent bonds and dopant orbitals enables the design of SnTe thermoelectrics.

Engineering the electronic band structures upon doping is crucial to improve the thermoelectric performance of materials. Understanding how dopants influence the electronic states near the Fermi level is thus a prerequisite to precisely tune band structures. Here, we demonstrate that the Sn-s states in SnTe contribute to the density of states at the top of the valence band. This is a consequence of the half-filled p-p σ-bond (metavalent bonding) and its resulting symmetry of the orbital phases at the valence band maximum (L point of the Brillouin zone). This insight provides a recipe for identifying superior dopants. The overlap between the dopant s- and the Te p-state is maximized, if the spatial overlap of both orbitals is maximized and their energetic difference is minimized. This simple design rule has enabled us to screen out Al as a very efficient dopant to enhance the local density of states for SnTe. In conjunction with doping Sb to tune the carrier concentration and alloying with AgBiTe2 to promote band convergence, as well as introducing dislocations to impede phonon propagation, a record-high average ZT of 1.15 between 300 and 873 K and a large ZT of 0.36 at 300 K is achieved in Sn0.8Al0.08Sb0.15Te-4%AgBiTe2.

p75NTR mediated chronic restraint stress-induced depression-like behaviors in mice via hippocampal mTOR pathway.

AIMS: Major depressive disorder (MDD) is an enduring and severe mood disorder. Previous studies have indicated that p75NTR is involved in neuronal survival and death. However, the specific mechanism of p75NTR in depression remains unknown. The present study aimed to explore the role and mechanism of p75NTR in depression, and try to provide a new target for the treatment of MDD. MAIN METHODS: The p75NTR knockout and overexpression mice were used to establish a mouse model of depression induced by chronic restraint stress (CRS), and the behavioral effects and potential mechanisms associated with p75NTR knockout/overexpression on CRS-induced depressive mice were investigated by animal behavior, histopathology, immunofluorescence and western blot, respectively. KEY FINDINGS: The results demonstrate that p75NTR knockout/overexpression can ameliorate the depressive-like behaviors observed in CRS-induced depressive mice. Furthermore, p75NTR knockout/overexpression safeguards the tissue morphology of the hippocampus, inhibits the mTOR signaling pathway to restore autophagy, and modulates apoptosis-related proteins (Bcl-2 and Bax) to reestablish normal levels of autophagy and apoptosis in hippocampal neurons of depressed mice. Importantly, p75NTR knockout/overexpression can improve synaptic plasticity through protecting the dendritic structure and dendritic spines of hippocampal neurons, and upregulating the expression of hippocampal synaptic-related proteins (PSD95 and SYN1). SIGNIFICANCE: These findings suggest that p75NTR knockout/overexpression can alleviate CRS-induced depression-like behaviors by reinstating autophagy and suppressing apoptosis in hippocampal neurons, and enhancing hippocampal synaptic plasticity via mTOR pathway. These insights may provide potential targets for clinical treatment of depression.

STAT3: Key targets of growth-promoting receptor positive breast cancer.

Breast cancer has become the malignant tumor with the first incidence and the second mortality among female cancers. Most female breast cancers belong to luminal-type breast cancer and HER2-positive breast cancer. These breast cancer cells all have different driving genes, which constantly promote the proliferation and metastasis of breast cancer cells. Signal transducer and activator of transcription 3 (STAT3) is an important breast cancer-related gene, which can promote the progress of breast cancer. It has been proved in clinical and basic research that over-expressed and constitutively activated STAT3 is involved in the progress, proliferation, metastasis and chemotherapy resistance of breast cancer. STAT3 is an important key target in luminal-type breast cancer and HER2-positive cancer, which has an important impact on the curative effect of related treatments. In breast cancer, the activation of STAT3 will change the spatial position of STAT3 protein and cause different phenotypic changes of breast cancer cells. In the current basic research and clinical research, small molecule inhibitors activated by targeting STAT3 can effectively treat breast cancer, and enhance the efficacy level of related treatment methods for luminal-type and HER2-positive breast cancers.

Prevalence and Clinical Implications of Hemosiderin Deposits in Recent Small Subcortical Infarcts.

BACKGROUND AND OBJECTIVES: A quarter of ischemic strokes are of lacunar clinical subtype and have an underlying recent small subcortical infarct (RSSI), but their long-term outcomes remain poorly characterized. Hemosiderin deposits (HDs) have been noted in RSSIs at chronic stages and might mimic primary hemorrhage. We characterized HDs' morphology, frequency, and clinical relevance. METHODS: Participants with RSSIs were identified from a prospective longitudinal study and evaluated on 3T MRI including susceptibility-weighted imaging (SWI) from stroke diagnosis to 12 months. We categorized HDs in RSSIs on SWI at all available time points into 4 types (spots, smudge, rim, cluster) and assessed their associations with demographic factors, stroke-related factors, and image markers with adjusted logistic regression. RESULTS: HDs were observed in 43 (55.0%) of 108 participants within 3 months and 83 (76.9%) of 108 within 12 months after stroke onset. The mean time to first detection of HDs was 87 (interquartile range 53-164) days. A "rim" pattern (similar to late appearance of primary hemorrhage) occurred in at least 26.5% of RSSIs at all follow-up time points, mainly those located in the lentiform/internal capsule (50.0%) or thalamus (36.4%). Infarct volume (odds ratio [OR] 1.003, 95% CI 1.001-1.006; p = 0.004) and the total small vessel disease (SVD) score at baseline (OR 2.50, 95% CI 1.28-4.86, p = 0.007) independently predicted HDs at 12 months. HDs were positively associated with more lacunes (OR 1.60, 95% CI 1.13-2.26, p < 0.01), but not the Fazekas score, number of microbleeds, basal ganglia mineral deposit score, or clinical outcomes. DISCUSSION: HDs occur commonly in RSSIs and may be associated with infarct volume and SVD score. Hemosiderin "rim" is common in RSSIs, urging caution to avoid mistaking ischemic RSSI for primary hemorrhage in subacute and chronic stages.

Doping strategy in metavalently bonded materials for advancing thermoelectric performance.

Metavalent bonding is a unique bonding mechanism responsible for exceptional properties of materials used in thermoelectric, phase-change, and optoelectronic devices. For thermoelectrics, the desired performance of metavalently bonded materials can be tuned by doping foreign atoms. Incorporating dopants to form solid solutions or second phases is a crucial route to tailor the charge and phonon transport. Yet, it is difficult to predict if dopants will form a secondary phase or a solid solution, which hinders the tailoring of microstructures and material properties. Here, we propose that the solid solution is more easily formed between metavalently bonded solids, while precipitates prefer to exist in systems mixed by metavalently bonded and other bonding mechanisms. We demonstrate this in a metavalently bonded GeTe compound alloyed with different sulfides. We find that S can dissolve in the GeTe matrix when alloyed with metavalently bonded PbS. In contrast, S-rich second phases are omnipresent via alloying with covalently bonded GeS and SnS. Benefiting from the reduced phonon propagation and the optimized electrical transport properties upon doping PbS in GeTe, a high figure-of-merit ZT of 2.2 at 773 K in (Ge0.84Sb0.06Te0.9)(PbSe)0.05(PbS)0.05 is realized. This strategy can be applied to other metavalently bonded materials to design properties beyond thermoelectrics.

Efficacy and Safety of Telitacicept in IgA Nephropathy: A Retrospective, Multicenter Study.

INTRODUCTION: The efficacy of telitacicept treatment in reducing proteinuria in patients with IgA nephropathy (IgAN) was indicated in a phase II clinical trial with small sample size. In this study, we conducted a large multicenter retrospective study to explore the efficacy and safety of telitacicept in patients with IgAN. METHODS: This study recruited patients with IgAN from 19 sites from China who were treated with telitacicept and had been followed up at least once or with side effect reported, since April 1, 2021, to April 1, 2023. The primary outcomes of the study were the changing in proteinuria and eGFR over time. RESULTS: A cohort of 97 patients with IgAN who were treated with telitacicept were recruited, with a median follow-up duration of 3 months. The median baseline proteinuria was 2.3 [1.3, 3.9] g/day and eGFR was 45.0 [26.8, 73.7] mL/min/1.73 m2. There was a significant reduction of proteinuria at 2, 4, 6 months when compared with baseline (2.3 [1.5, 4.1] vs. 1.5 [0.8, 2.3] g/day; 2.3 [1.1, 3.7] vs. 1.1 [0.6, 1.9] g/day; 2.1 [1.0, 2.7] vs. 0.9 [0.5, 1.7] g/day, all p values <0.01). The level of eGFR were comparable between at the baseline and 2, 4, 6 months of follow-up time (41.5 [29.7, 72.0] vs. 42.5 [28.8, 73.3] mL/min/1.73 m2; 41.0 [26.8, 67.7] vs. 44.7 [31.0, 67.8] mL/min/1.73 m2; 33.7 [24.0, 58.5] vs. 32.6 [27.8, 57.5] mL/min/1.73 m2, all p values >0.26). Telitacicept was well tolerated in the patients. CONCLUSIONS: This study indicates that telitacicept alone or on top of steroids therapy can significantly and safely reduce proteinuria in patients with IgAN. The long-term kidney protection still needs to be confirmed in large phase III trial.

Effects of T2DM on cancer progression: pivotal precipitating factors and underlying mechanisms.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder affecting people worldwide. It is characterized by several key features, including hyperinsulinemia, hyperglycemia, hyperlipidemia, and dysbiosis. Epidemiologic studies have shown that T2DM is closely associated with the development and progression of cancer. T2DM-related hyperinsulinemia, hyperglycemia, and hyperlipidemia contribute to cancer progression through complex signaling pathways. These factors increase drug resistance, apoptosis resistance, and the migration, invasion, and proliferation of cancer cells. Here, we will focus on the role of hyperinsulinemia, hyperglycemia, and hyperlipidemia associated with T2DM in cancer development. Additionally, we will elucidate the potential molecular mechanisms underlying their effects on cancer progression. We aim to identify potential therapeutic targets for T2DM-related malignancies and explore relevant directions for future investigation.

Association of Methylenetetrahydrofolate Reductase rs1801133 Polymorphism with osteoporosis and fracture risk in Taiwan.

Introduction: Osteoporosis is a prevalent skeletal disorder influenced by age, hormonal changes, medication use, nutrition, and genetics. The relationship between MTHFR and osteoporosis remains unclear, especially in Asians. The aim of our study was to elucidate the impact of MTHFR on osteoporosis and fracture risk. Materials and Methods: Participants were recruited from the Taiwan Precision Medicine Initiative at Taichung Veterans General Hospital. A total of 3,503 subjects with available bone mineral density measurements were selected. Using the Axiom Genome-Wide TWB 2.0 Array, we identified the MTHFR rs1801133 variant. Among these subjects, 1,624 patients carrying the variant were included in the case group, while the remaining 1,879 patients without the variant served as the control group. Results: Overall, individuals carrying the MTHFR rs1801133 variant exhibited a significantly elevated risk of developing osteoporosis. Stratified analysis by different genotypes, the results revealed a statistically significant association between the heterozygous genotype of MTHFR rs1801133 and osteoporosis. However, there was no significant correlation between MTHFR genotypes and fracture risk. Furthermore, subgroup analysis of female patients revealed age, a known risk factor, was associated with both osteoporosis and fractures. Interestingly, the presence of the MTHFR rs1801133 variant did not confer an increased risk of osteoporosis or fractures in females. Conclusion: Our study revealed a notable increase in the prevalence of osteoporosis among individuals carrying the MTHFR rs1801133 variant. Nevertheless, these individuals did not exhibit a heightened risk of major or hip fractures compared to non-carriers. Our findings could be of value in raising awareness of the increased risk of osteoporosis among individuals with this genetic variant.

18F-Florbetaben PET/CT for the Diagnosis and Subtyping of Cardiac Amyloidosis: A Case Series and Review of the Literature.

Objectives: Cardiac amyloidosis (CA) is a type of systemic amyloidosis. Amyloid-targeting positron emission tomography (PET) has shown potential as an imaging method for CA. However, the optimal imaging protocol and role of 18F-florbetaben (FBB) PET in the diagnosis and subtyping of CA have yet to be determined. Methods: Patients with suspected CA who had positive or equivocal results of technetium-99m pyrophosphate (PYP) scintigraphy were enrolled for dynamic and late FBB PET imaging. In addition to visual assessment, a kinetic modeling-based approach including target-to-background ratio (TBR) and myocardial retention fraction (RF) of serial images reconstructed from a 20-min dynamic acquisition, and a late image at 110 min post-injection were performed. We compared FBB PET measures of four typical patients with light chain amyloidosis (AL), wild-type transthyretin amyloidosis (ATTRwt), variant transthyretin amyloidosis (ATTRv), and heart failure, respectively. We also reviewed the literature on the clinical use of amyloid PET in CA. Results: Myocardial tracer retention was only found in the AL patient on the late images. TBR and RF were highest in the AL patient followed by the ATTRwt patient, and lowest in the ATTRv and non-CA patients. Conclusions: FBB PET has potential in the detection and non-invasive subtyping of CA, especially in subjects with equivocal PYP findings or monoclonal gammopathy.

Towards Establishing Best Practice in the Analysis of Hydrogen and Deuterium by Atom Probe Tomography.

As hydrogen is touted as a key player in the decarbonization of modern society, it is critical to enable quantitative hydrogen (H) analysis at high spatial resolution and, if possible, at the atomic scale. H has a known deleterious impact on the mechanical properties (strength, ductility, toughness) of most materials that can hinder their use as part of the infrastructure of a hydrogen-based economy. Enabling H mapping including local hydrogen concentration analyses at specific microstructural features is essential for understanding the multiple ways that H affect the properties of materials including embrittlement mechanisms and their synergies. In addition, spatial mapping and quantification of hydrogen isotopes is essential to accurately predict tritium inventory of future fusion power plants thus ensuring their safe and efficient operation. Atom probe tomography (APT) has the intrinsic capability to detect H and deuterium (D), and in principle the capacity for performing quantitative mapping of H within a material's microstructure. Yet, the accuracy and precision of H analysis by APT remain affected by complex field evaporation behavior and the influence of residual hydrogen from the ultrahigh vacuum chamber that can obscure the signal of H from within the material. The present article reports a summary of discussions at a focused workshop held at the Max-Planck Institute for Sustainable Materials in April 2024. The workshop was organized to pave the way to establishing best practices in reporting APT data for the analysis of H. We first summarize the key aspects of the intricacies of H analysis by APT and then propose a path for better reporting of the relevant data to support interpretation of APT-based H analysis in materials.

Machine Learning-Enabled Tomographic Imaging of Chemical Short-Range Atomic Ordering.

In solids, chemical short-range order (CSRO) refers to the self-organization of atoms of certain species occupying specific crystal sites. CSRO is increasingly being envisaged as a lever to tailor the mechanical and functional properties of materials. Yet quantitative relationships between properties and the morphology, number density, and atomic configurations of CSRO domains remain elusive. Herein, it is showcased how machine learning-enhanced atom probe tomography (APT) can mine the near-atomically resolved APT data and jointly exploit the technique's high elemental sensitivity to provide a 3D quantitative analysis of CSRO in a CoCrNi medium-entropy alloy. Multiple CSRO configurations are revealed, with their formation supported by state-of-the-art Monte-Carlo simulations. Quantitative analysis of these CSROs allows establishing relationships between processing parameters and physical properties. The unambiguous characterization of CSRO will help refine strategies for designing advanced materials by manipulating atomic-scale architectures.

A Study of Improved Two-Stage Dual-Conv Coordinate Attention Model for Sound Event Detection and Localization.

Sound Event Detection and Localization (SELD) is a comprehensive task that aims to solve the subtasks of Sound Event Detection (SED) and Sound Source Localization (SSL) simultaneously. The task of SELD lies in the need to solve both sound recognition and spatial localization problems, and different categories of sound events may overlap in time and space, making it more difficult for the model to distinguish between different events occurring at the same time and to locate the sound source. In this study, the Dual-conv Coordinate Attention Module (DCAM) combines dual convolutional blocks and Coordinate Attention, and based on this, the network architecture based on the two-stage strategy is improved to form the SELD-oriented Two-Stage Dual-conv Coordinate Attention Model (TDCAM) for SELD. TDCAM draws on the concepts of Visual Geometry Group (VGG) networks and Coordinate Attention to effectively capture critical local information by focusing on the coordinate space information of the feature map and dealing with the relationship between the feature map channels to enhance the feature selection capability of the model. To address the limitation of a single-layer Bi-directional Gated Recurrent Unit (Bi-GRU) in the two-stage network in terms of timing processing, we add to the structure of the two-layer Bi-GRU and introduce the data enhancement techniques of the frequency mask and time mask to improve the modeling and generalization ability of the model for timing features. Through experimental validation on the TAU Spatial Sound Events 2019 development dataset, our approach significantly improves the performance of SELD compared to the two-stage network baseline model. Furthermore, the effectiveness of DCAM and the two-layer Bi-GRU structure is confirmed by performing ablation experiments.

Effects of graphene oxide and graphene quantum dots on enhancing CPP-ACP anti-caries ability of enamel lesion in a biofilm-challenged environment.

OBJECTIVE: To investigate the anticaries effects of graphene oxide (GO) and graphene quantum dots (GQDs) combined with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on enamel in a biofilm-challenged environment. MATERIAL AND METHODS: GO and GQDs were synthesised using citric acid. The antibiofilm and biofilm inhibition effects for Streptococcus mutans were evaluated by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming units (CFU). Remineralisation ability was determined by assessing mineral loss, calcium-to-phosphorus ratio, and surface morphology. To create a biofilm-challenged environment, enamel blocks were immersed in S. mutans to create the lesion and then subjected to artificial saliva/biofilm cycling for 7 days. Anticaries effects of GO, GQDs, GQDs@CPP-ACP, GO@CPP-ACP, and CPP-ACP were determined by broth pH and mineral changes after 7-day pH cycling. Biocompatibility was tested using a Cell Counting Kit-8 (CCK8) assay for human gingival fibroblasts (HGF-1). RESULTS: GQDs and GO presented significant antibiofilm and biofilm inhibition effects compared to the CPP-ACP and control groups (P < 0.05). The enamel covered by GQDs and GO showed better crystal structure formation and less mineral loss (P < 0.05) than that covered by CPP-ACP alone. After 7 days in the biofilm-challenged environment, the GO@CPP-ACP group showed less lesion depth than the CPP-ACP and control groups (P < 0.05). GO and GQDs showed good biocompatibility compared to the control group by CCK8 (P > 0.05) within 3 days. CONCLUSION: GO and GQDs could improve the anti-caries effects of CPP-ACP, and CPP-ACP agents with GO or GQDs could be a potential option for enamel lesion management. CLINICAL SIGNIFICANCE: GO and GQDs have demonstrated the potential to significantly enhance the anticaries effects of CPP-ACP. Incorporating these nanomaterials into CPP-ACP formulations could provide innovative and effective options for the management of enamel lesions, offering improved preventive and therapeutic strategies in dental care.

Broadband stepped-frequency radar waveform generation by Fourier domain mode-locking period-one laser dynamics.

A stepped-frequency (SF) radar waveform generation method based on Fourier domain mode-locking (FDML) period-one laser dynamics is proposed and demonstrated. By fast controlling the optical injection strength of a semiconductor laser through electro-optical modulation, a broadband SF signal is generated. By further introducing an optoelectronic feedback loop with its round trip time delay matched with the temporal period of the SF signal, FDML is enabled through which the frequency stability, accuracy, and in-band signal-to-noise ratio are greatly improved. In the experiment, SF signals with a bandwidth of 6 GHz (12-18 GHz) and a frequency step of 150 MHz are generated. By comparing the qualities of signals generated with and without FDML, advantages of the proposed SF signal generation method are verified. Based on the proposed SF signal generation method, high-resolution inverse synthetic aperture radar (ISAR) imaging is also demonstrated, in which the 2D imaging resolution reaches 2.6 cm × 3.82 cm.