In this paper, a new feedforward active noise control (FFANC) system is proposed that is equipped with both online secondary- and feedback-path modeling (OSPM, OFBPM). It is a refined and updated version of an existing FFANC system with the OSPM and OFBPM. The proposed system presents improved noise reduction performance (NRP) in presence of time-varying secondary and feedback paths. Two major contributions are made in this work. First, a new FIR supporting filter (SF) is added to the controller, whose output is a less noisy estimate of the remaining target noise and is used to update the controller. Second, a global scaling scheme is applied to the auxiliary white Gaussian noise (AWGN) that is injected into the secondary source to facilitate both the OSPM and OFBPM. The new SF output, rather than the residual error, is also utilized to perform the global AWGN scaling that significantly reduces the AWGN contribution to the residual error. Furthermore, an approximate steady-state analysis is conducted in detail to reveal the statistical properties of the new SF and the global AWGN scaling scheme. The proposed FFANC system is extensively simulated with synthetic and real settings data to demonstrate its NRP superiority over its counterparts.

Interfacial interaction is a key element in epitaxial growth. While theoretical studies have highlighted its importance for the structure and stability of phosphorene on various substrates, direct experimental verification remains scarce. Here, we systematically investigate the interfacial interactions of diverse phosphorene structures on Au(111), Ag(111), and Cu(111) surfaces and reveal a positive correlation between the structural stability and interfacial interaction strength on the same substrate. Crucially, we observed a distinct difference in growth pathways. On Au(111) and Ag(111), the final structures appear to be kinetically limited under the experimental conditions, whereas on Cu(111), the phase evolution tends toward coverage-dependent ordering, suggestive of thermodynamic influence. This distinction may stem from the dominant intralayer bonding on a weakly interacting substrate versus competition between interfacial and intralayer interactions on a strongly coupling substrate. This work experimentally distinguishes kinetically and thermodynamically dominated growth regimes of phosphorene on noble metal substrates, correlating the transition with interfacial interaction strength.

The hybrid active noise control (HANC) has been developed in the literature to solely suppress two uncorrelated noise sources. It degrades severely in performance and even suffers from instability when the two noise sources are correlated. In this paper, a novel HANC system is proposed that works effectively even in such a challenging scenario. An adaptive linear prediction filter (LPF) is included and applied to the first noise source reference signal that involves not only a broadband component but also a narrowband one that is correlated with the second noise source of narrowband nature. The LPF error and output are fed to the feedforward broadband ANC (FFBANC) and a newly added feedforward narrowband ANC (FFNANC) subcontroller, respectively. A previously equipped and a newly included supporting filters extract, from the residual error, the remaining broadband and narrowband components that are adopted to update the two feedforward subcontrollers, respectively. Consequently, the FFBANC, FFNANC and the feedback ANC (FBANC) subcontrollers become substantially decoupled, rendering the proposed HANC system effective regardless of the statistical relation between the two noise sources. The proposed HANC system is extensively simulated with both synthetic and real settings to reveal its effectiveness and capabilities.

The search for a high-efficiency, low-cost, and sustainable cadmium (Cd)-free buffer has long challenged the commercialization of Cu(In,Ga)Se2 (CIGSe) photovoltaics. Here, we report an all‑dry, scalable vacuum deposition strategy of an ultrathin γ-In2Se3 buffer layer using only absorber‑native elements, enabling high-performance Cd-free CIGSe solar cells. Fully compatible with vacuum manufacturing and requires no additional equipment. Owing to its strong thickness-dependent electronic and optical properties, an unconventionally thin ( ~ 10 nm) γ-In2Se3 layer exhibits a widened bandgap ( ~ 3.10 eV), avoiding the parasitic absorption and poor conductivity associated with thicker films. By optimizing growth conditions, thickness, and post-treatments, certified conversion efficiency exceeding 20% and good thermal stability (98.7% retention after 1032 h at 90 °C) are achieved. Techno-economic analysis suggests that compatibility with existing vacuum manufacturing processes could reduce the levelized cost of electricity by ~10%. Cadmium-free buffer layers are needed to make copper indium gallium selenide solar cells efficient, affordable and sustainable. Li et al. deposited an ultrathin indium selenide layer, achieving over 20% efficiency, strong thermal stability and lower projected electricity costs.

Introduction:Postmenopausal osteoporosis, characterized by progressive loss of bone mass and deterioration of skeletal microarchitecture, remains a major public health concern worldwide. Exosomes derived from mesenchymal stem cells (MSC-Exos) are nanosized extracellular vesicles enriched with bioactive cargo, have emerged as potent cell-free mediators of tissue regeneration and immunomodulation. However, their clinical translation is hindered by rapid clearance and insufficient retention at target sites. In this study, we developed a biocompatible microdroplet (MD)-based delivery platform incorporating MSC-derived exosomes (MD/Exos) and evaluated its therapeutic potential for osteoporosis treatment. Methods:MSC-Exos were isolated from human bone marrow-derived mesenchymal stem cells (hBMSCs) and characterized by transmission electron microscopy and exosomal marker analysis. MD/Exos were fabricated and evaluated for cellular uptake and cytocompatibility. The effects of MD/Exos on hBMSC proliferation, osteogenic differentiation, and macrophage inflammatory responses were investigated in vitro. Therapeutic efficacy was further assessed in an ovariectomy-induced osteoporotic rat model through histological and cytokine analyses. Results:MSC-Exos exhibited characteristic exosomal morphology and were efficiently internalized by both hBMSCs and RAW264.7 macrophages. The fabricated MD/Exos system demonstrated excellent cytocompatibility in vitro and favorable histocompatibility in vivo. In vitro, MD/Exos significantly enhanced osteogenic differentiation of hBMSCs and altered macrophage inflammatory cytokine profiles, suggesting a coordinated effect on osteogenesis and inflammatory regulation. In an ovariectomy-induced osteoporotic rat model, MD-Exo treatment effectively preserved trabecular bone microarchitecture, reduced marrow adiposity, and markedly inhibited osteoclast activity. Conclusion:MD/Exos represent a promising exosome delivery strategy for osteoporosis treatment.

Radiation-induced bone loss, driven by osteoclast activation, involves the transcription factor nuclear factor of activated T-cells cytoplasmic 1 (NFATc1)-mediated signaling. This study developed NFATc1 siRNA-loaded microdroplets (NFATc1/MDs) to mitigate skeletal damage post-radiotherapy. METHODS:NFATc1/MDs were synthesized and characterized using TEM and confocal microscopy. Biocompatibility was tested in hBMSCs and RAW 264.7 macrophages. Osteoclastogenesis, osteogenesis, and adipogenesis were assessed in vitro, and therapeutic efficacy was evaluated in a rat radiation-induced bone loss model. RESULTS:NFATc1/MDs exhibited a core-shell structure, high biocompatibility, and efficient cellular uptake. They suppressed osteoclastogenesis without impairing osteogenic/adipogenic differentiation and modulated macrophage activity post-irradiation. In vivo, NFATc1/MDs preserved bone microstructure, reduced osteoclast numbers, and downregulated NFATc1, cathepsin K (CTSK), and tumor necrosis factor-alpha (TNF-α) expression. CONCLUSIONS:NFATc1/MDs effectively inhibited osteoclast-mediated bone resorption and inflammation, offering a targeted strategy to prevent radiation-induced bone loss. This biocompatible platform demonstrates potential for clinical translation in radiotherapy-associated skeletal complications.

Osteoporosis, a condition marked by reduced bone mass and structural deterioration, continues to be a major public health concern, especially as global populations age. Excessive osteoclast formation is a hallmark of osteoporosis. The transcription factor nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) is indispensable for the early differentiation of osteoclasts, orchestrating the expression of essential genes, while at the later stages, cathepsin K (CTSK) is essential for bone resorption activities of mature osteoclasts. Here, we fabricated ultrasound-responsive microdroplets (MDs) by modulating both the early stages of osteoclast differentiation and the functions of mature osteoclasts via targeting the NFATc1 and CTSK. The internalization of these dual MDs was evaluated in human bone marrow-derived mesenchymal stromal cells (hBMSCs) and murine RAW 264.7 macrophages, alongside the biocompatibility assay. Their effects on osteogenesis and osteoclastogenesis were further investigated in vitro, followed by in vivo analysis in osteoporotic rat models. The dual MDs exhibited a well-defined core-shell structure and demonstrated efficient cellular uptake with minimal cytotoxicity. Furthermore, dual MDs showed a minimal effect on the osteogenic differentiation of the hBMSCs. In in vitro osteoclastogenesis assays, dual MDs effectively suppressed both osteoclast differentiation and formation through a synergistic inhibitory effect. In vivo studies demonstrated that osteoporotic rats receiving dual MDs showed significant protection against bone loss induced by ovariectomy. These results highlight the potential of dual MDs as a sophisticated, targeted therapeutic approach to osteoporosis treatment.

The burden of long bone fractures impacts society profoundly. Polylactic acid (PLA) and PLA-based scaffolds have been widely used for bone tissue engineering due to its biodegradable and non-toxic properties. However, PLA scaffolds possess no biological and immunoregulatory activity. In addition, M2 phenotypic macrophages and M2 macrophage inducer have shown pro-healing effect. Therefore, in this study, we sought to harness the potent osteo-immunomodulatory properties of anti-inflammatory M2 macrophages and encapsulated bioactive interleukin-4 microdroplets (MDs) into the PLA scaffold matrix in order to enhance the biological activity and osteo-immunomodulatory properties of PLA scaffold. The MTT assay, live and dead staining, and phalloidin/DAPI dual staining were used to evaluate biocompatibility in human bone marrow mesenchymal stem cells (hBMSCs). Unstimulated macrophages and inflammatory macrophages were further used to test its immunoregulatory role. The immunoregulatory role of MDs-IL4/PLA hybrid scaffolds on hBMSCs differentiation was further investigated in vitro. The MDs-IL4/PLA hybrid scaffolds showed high biocompatibility in hBMSCs. In addition, MDs-IL4/PLA hybrid scaffolds demonstrated good immunoregulatory role in unstimulated and inflammatory macrophages, as evidenced by marked morphological changes, significantly increased M2 phenotypic markers, and reduction of pro-inflammatory marker expression, etc. Furthermore, our results indicate that the MDs-IL4/PLA hybrid scaffolds could significantly enhance the osteogenic differentiation of hBMSCs via its potential immunomodulatory properties. The subcutaneous implantation of MDs-IL4/PLA scaffold demonstrated significant increases in IL-4, IL-10, CCL2, CCL20, beta-NGF, and TIMP-1 expressions, indicating its notable in vivo immunomodulatory effects. By harnessing the synergistic effects of PLA and MDs-IL4, this novel scaffold holds promise for advancing regenerative medicine approaches, particularly in bone tissue engineering.

Ultrawide bandgap (UWBG) semiconductors, including Ga2O3, diamond, Al x Ga1-x N/AlN, featuring bandgaps greater than 4.4 eV, hold significant promise for solar-blind ultraviolet photodetection, with applications spanning in environmental monitoring, chemical/biological analysis, industrial processes, and military technologies. Over recent decades, substantial strides in synthesizing high-quality UWBG semiconductors have facilitated the development of diverse high-performance solar-blind photodetectors (SBPDs). This review comprehensively examines recent advancements in UWBG semiconductor-based SBPDs across various device architectures, encompassing photoconductors, metal-semiconductor-metal photodetectors, Schottky photodiodes, p-n (p-i-n) photodiodes, phototransistors, etc., with a systematic introduction and discussion of their operational principles. The current state of device performance for SBPDs employing these UWBG semiconductors is evaluated across different device configurations. Finally, this review outlines key challenges to be addressed, aiming to steer future research endeavors in this critical domain.

Borophene, a promising material with potential applications in electronics, energy storage, and sensors, is successfully grown as a monolayer on Ag(111), Cu(111), and Au(111) surfaces using molecular beam epitaxy. The growth of two-dimensional borophene on Ag(111) and Au(111) is proposed to occur via surface adsorption and boron segregation, respectively. However, the growth mode of borophene on Cu(111) remains unclear. To elucidate this, scanning tunneling microscopy in conjunction with theoretical calculations is used to study the phase transformation of boron nanostructures under post-annealing treatments. Results show that by elevating the substrate temperature, boron nanostructures undergo an evolution from amorphous boron to striped-phase borophene (eta = 1/6) adhering to the Cu < 1 (1) over bar0 > step edge, and finally to irregularly shaped beta-type borophene (eta = 5/36) either on the substrate surface or embedded in the topmost Cu layer. dI/dV spectra recorded near the borophene/Cu lateral interfaces indicate that the striped-phase borophene is a metastable phase, requiring more buckling and electron transfer to stabilize the crystal structure. These findings offer not only an in-depth comprehension of the beta-type borophene formation on Cu(111), but also hold potential for enabling borophene synthesis on weakly-binding semiconducting or insulating substrates with 1D active defects.

Correction for 'Development of bioactive and ultrasound-responsive microdroplets for preventing ovariectomy (OVX)-induced osteoporosis' by Yi Zhang et al., J. Mater. Chem. B, 2023, 11, 11344-11356, https://doi.org/10.1039/D3TB01726E.

Bone defects represent a prevalent category of clinical injuries, causing significant pain and escalating health care burdens. Effectively addressing bone defects is thus of paramount importance. Platelets, formed from megakaryocyte lysis, have emerged as pivotal players in bone tissue repair, inflammatory responses, and angiogenesis. Their intracellular storage of various growth factors, cytokines, and membrane protein receptors contributes to these crucial functions. This article provides a comprehensive overview of platelets' roles in hematoma structure, inflammatory responses, and angiogenesis throughout the process of fracture healing. Beyond their application in conjunction with artificial bone substitute materials for treating bone defects, we propose the potential future use of anticoagulants such as heparin in combination with these materials to regulate platelet number and function, thereby promoting bone healing. Ultimately, we contemplate whether manipulating platelet function to modulate bone healing could offer innovative ideas and directions for the clinical treatment of bone defects. Impact statement Given that 5-10% of fracture patients with delayed bone healing or even bone nonunion, this review explores the potential role of platelets in bone healing (directly/indirectly) and proposes ideas and directions for the future as to whether it is possible to promote bone healing and improve fracture healing rates by modulating platelets.

Stroke is a severe neurological disease that is associated with high rates of morbidity and mortality, and the underlying pathological processes are complex. Ferroptosis fulfills a significant role in the progression and treatment of stroke. It is well established that ferroptosis is a type of programmed cell death that is distinct from other forms or types of cell death. The process of ferroptosis involves multiple signaling pathways and regulatory mechanisms that interact with mechanisms inherent to stroke development. Inducers and inhibitors of ferroptosis have been shown to exert a role in the onset of this cell death process. Furthermore, it has been shown that interfering with ferroptosis affects the occurrence of stroke, indicating that targeting ferroptosis may offer a promising therapeutic approach for treating patients of stroke. Hence, the present review aimed to summarize the latest progress that has been made in terms of using therapeutic interventions for ferroptosis as treatment targets in cases of stroke. It provides an overview of the relevant pathways and molecular mechanisms that have been investigated in recent years, highlighting the roles of inducers and inhibitors of ferroptosis in stroke. Additionally, the intervention potential of various types of Traditional Chinese Medicine is also summarized. In conclusion, the present review provides a comprehensive overview of the potential therapeutic targets afforded by ferroptosis‑associated pathways in stroke, offering new insights into how ferroptosis may be exploited in the treatment of stroke.

Introduction:Osteoporotic-related fractures remains a significant public health concern, thus imposing substantial burdens on our society. Excessive activation of osteoclastic activity is one of the main contributing factors for osteoporosis-related fractures. While polylactic acid (PLA) is frequently employed as a biodegradable scaffold in tissue engineering, it lacks sufficient biological activity. Microdroplets (MDs) have been explored as an ultrasound-responsive drug delivery method, and mesenchymal stem cell (MSC)-derived exosomes have shown therapeutic effects in diverse preclinical investigations. Thus, this study aimed to develop a novel bioactive hybrid PLA scaffold by integrating MDs-NFATc1-silencing siRNA to target osteoclast formation and MSCs-exosomes (MSC-Exo) to influence osteogenic differentiation (MDs-NFATc1/PLA-Exo).Methods:Human bone marrow-derived mesenchymal stromal cells (hBMSCs) were used for exosome isolation. Transmission electron microscopy (TEM) and confocal laser scanning microscopy were used for exosome and MDs morphological characterization, respectively. The MDs-NFATc1/PLA-Exo scaffold was fabricated through poly(dopamine) and fibrin gel coating. Biocompatibility was assessed using RAW 264.7 macrophages and hBMSCs. Osteoclast formations were examined via TRAP staining. Osteogenic differentiation of hBMSCs and cytokine expression modulation were also investigated.Results:MSC-Exo exhibited a cup-shaped structure and effective internalization into cells, while MDs displayed a spherical morphology with a well-defined core-shell structure. Following ultrasound stimulation, the internalization study demonstrated efficient delivery of bioactive MDs into recipient cells. Biocompatibility studies indicated no cytotoxicity of MDs-NFATc1/PLA-Exo scaffolds in RAW 264.7 macrophages and hBMSCs. Both MDs-NFATc1/PLA and MDs-NFATc1/PLA-Exo treatments significantly reduced osteoclast differentiation and formation. In addition, our results further indicated MDs-NFATc1/PLA-Exo scaffold significantly enhanced osteogenic differentiation of hBMSCs and modulated cytokine expression.Discussion:These findings suggest that the bioactive MDs-NFATc1/PLA-Exo scaffold holds promise as an innovative structure for bone tissue regeneration. By specifically targeting osteoclast formation and promoting osteogenic differentiation, this hybrid scaffold may address key challenges in osteoporosis-related fractures.

Purpose: Ischemic stroke is a refractory disease wherein the reperfusion injury caused by sudden restoration of blood supply is the main cause of increased mortality and disability. However, current therapeutic strategies for the inflammatory response induced by cerebral ischemia-reperfusion (I/R) injury are unsatisfactory. This study aimed to develop a functional nanoparticle (MM/ANPs) comprising apelin-13 (APNs) encapsulated in macrophage membranes (MM) modified with distearoyl phosphatidylethanolaminepolyethylene glycol-RVG29 (DSPE-PEG-RVG29) to achieve targeted therapy against ischemic stroke. Methods: MM were extracted from RAW264.7. PLGA was dissolved in dichloromethane, while Apelin-13 was dissolved in water, and CY5.5 was dissolved in dichloromethane. The precipitate was washed twice with ultrapure water and then resuspended in 10 mL to obtain an aqueous solution of PLGA nanoparticles. Subsequently, the cell membrane was evenly dispersed homogeneously and mixed with PLGA-COOH at a mass ratio of 1:1 for the hybrid ultrasound. DSPE-PEG-RVG29 was added and incubated for 1 h to Results: In this study, we developed a functional nanoparticle delivery system (MM/ANPs) that utilizes macrophage membranes coated with DSPE-PEG-RVG29 peptide to efficiently deliver Apelin-13 to inflammatory areas using ischemic stroke therapy. MM/ ANPs effectively cross the blood-brain barrier and selectively accumulate in ischemic and inflamed areas. In a mouse I/R injury model, these nanoparticles significantly improved neurological scores and reduced infarct volume. Apelin-13 is gradually released from the MM/ANPs, inhibiting NLRP3 inflammasome assembly by enhancing sirtuin 3 (SIRT3) activity, which suppresses the inflammatory response and pyroptosis. The positive regulation of SIRT3 further inhibits the NLRP3-mediated inflammation, showing the clinical potential of these nanoparticles for ischemic stroke treatment. The biocompatibility and safety of MM/ANPs were confirmed through in vitro cytotoxicity tests, blood-brain barrier permeability tests, biosafety evaluations, and blood compatibility studies. Conclusion: MM/ANPs offer a highly promising approach to achieve ischemic stroke-targeted therapy inhibiting NLRP3 inflammasome-mediated pyroptosis.

Correction for 'Development of bioactive and ultrasound-responsive microdroplets for preventing ovariectomy (OVX)-induced osteoporosis' by Yi Zhang et al., J. Mater. Chem. B, 2023, 11, 11344-11356, https://doi.org/10.1039/D3TB01726E.

Ischemic stroke poses a major threat to human health. Therefore, the molecular mechanisms of cerebral ischemia/reperfusion injury (CIRI) need to be further clarified, and the associated treatment approaches require exploration. The NOD‑like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome serves an important role in causing CIRI, and its activation exacerbates the underlying injury. Activation of the NLRP3 inflammasome triggers the maturation and production of the inflammatory molecules IL‑1β and IL‑18, as well as gasdermin‑D‑mediated pyroptosis and CIRI damage. Thus, the NLRP3 inflammasome may be a viable target for the treatment of CIRI. In the present review, the mechanisms of the NLRP3 inflammasome in the intense inflammatory response and pyroptosis induced by CIRI are discussed, and the therapeutic strategies that target the NLRP3‑mediated inflammatory response and pyroptosis in CIRI are summarized. At present, certain drugs have already been studied, highlighting future therapeutic perspectives.

Stroke poses a significant risk of mortality, particularly among the elderly population. The pathophysiological process of ischemic stroke is complex, and it is crucial to elucidate its molecular mechanisms and explore potential protective drugs. Ferroptosis, a newly recognized form of programmed cell death distinct from necrosis, apoptosis, and autophagy, is closely associated with the pathophysiology of ischemic stroke. N6022, a selective inhibitor of S-nitrosoglutathione reductase (GSNOR), is a "first-in-class" drug for asthma with potential therapeutic applications. However, it remains unclear whether N6022 exerts protective effects in ischemic stroke, and the precise mechanisms of its action are unknown. This study aimed to investigate whether N6022 mitigates cerebral ischemia/reperfusion (I/R) injury by reducing ferroptosis and to elucidate the underlying mechanisms. Accordingly, we established an oxygen-glucose deprivation/reperfusion (OGD/R) cell model and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to mimic cerebral I/R injury. Our data, both in vitro and in vivo, demonstrated that N6022 effectively protected against I/R-induced brain damage and neurological deficits in mice, as well as OGD/R-induced BV2 cell damage. Mechanistically, N6022 promoted Nrf2 nuclear translocation, enhancing intracellular antioxidant capacity of SLC7A11-GPX4 system. Furthermore, N6022 interfered with the interaction of GSNOR with GSTP1, thereby boosting the antioxidant capacity of GSTP1 and attenuating ferroptosis. These findings provide novel insights, showing that N6022 attenuates microglial ferroptosis induced by cerebral I/R injury through the promotion of Nrf2 nuclear translocation and inhibition of the GSNOR/GSTP1 axis.

Cu2Sn1-xGexS3 (CTGS) thin films were created through sulfurizing SnGe/Cu precursors deposited by the sputtering method. The effects of different sulfurization conditions on the crystallinity, morphology, composition, optical-electrical properties and chemical information of the CTGS thin films have been investigated in detail. The results demonstrate that the CTGS thin films obtained by using sulfurization temperature at 550°C for 20min have the best crystal quality and smooth surface morphology with largest grains and the best optical-electrical properties. Meanwhile, CTGS thin films solar cell with the best performance is found that the CTGS film possesses a graded band gap structure, in which the band gap gradually become larger towards the Mo electrode, and the CdS/CTGS hetero-junction interface shows the “type I” energy band alignment with a “spike-like” structure. As a result, the obtained bandgap-graded CTGS thin film solar cells with the best power conversion efficiency (PCE) of 3.35 (± 0.04) % manifest an open-circuit voltage of 389 (± 7.78) mV and a short-circuit current density of 26.98 (± 0.54) mA cm-2 . This work demonstrates a promising route to develop high-efficiency Cu(In,Ga)Se2 or Cu2SnS3-based thin film solar cells.