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Photoacoustic (PA) imaging has emerged as a promising bio-imaging technique due to its non-invasive visualization of lesions at great penetration depths. Fluorescence (FL) imaging in the second near-infrared window (NIR-II, 1000–1700 nm) achieves a higher imaging resolution and lower background signals compared to NIR-I. However, the single imaging method possesses its own disadvantages. Thus, we have demonstrated ZIF-8–IR820–MnPc–HA nanoparticles (ZIMH NPs) that can achieve visualization and localization of tumors in mice models with the help of a dual-modality PA/NIR-II FL imaging performance. Meanwhile, these excellent nanoparticles also induce the efficient generation of singlet oxygen (1O2) upon 808 nm laser illumination, and display excellent photodynamic therapy efficacy in cells, further indicating their potential application for in vivo PDT. In ZIMH NPs, hyaluronic acid (HA) impressively acts as a “sponge”, enhancing the generation of 1O2 and facilitating the cellular therapeutic effects. We believe that ZIF-8–IR820–MnPc–HA NPs present a brand-new strategy for the exploration of efficient PDT photosensitizers with dual-modality imaging performance for use in various biomedical applications.

Compared with the near-infrared-I spectral window (NIR-I, 650–950 nm), a newly developed imaging and treatment window with a 1000–1700 nm range (defined as the NIR-II bio-window) has attracted much attention owing to its higher spatiotemporal resolution, increased tissue penetration depth and therapeutic efficacy. Herein, we designed a nanotheranostic platform (HC-AB NPs) via loading ammonia borane (AB) into hollow carbon nanoparticles (HCs) for NIR-II photoacoustic (PA) imaging-guided NIR-II hydrogenothermal therapy. Importantly, by exploiting the characteristics of beta zeolite as a hard template and a template-carbonization-corrosion process, the prepared HCs have excellent NIR-II absorption performance and AB loading capacity. With the high biocompatibility of HC-AB NPs, an efficient synergistic anti-tumor strategy has been achieved via high intratumoural accumulation and acid-stimulated H2 release as well as PA-guided precise NIR-II photothermal therapy. The HC-AB NPs as a promising nanotheranostic platform opens a new avenue for high-efficacy NIR-II hydrogenothermal therapy.

Stimuli-responsive silica nanoparticles are an attractive therapeutic agent for effective tumor ablation, but the responsiveness of silica nanoagents is limited by intrastimulation level and silica framework structure. Herein, a biodegradable hollow SiO2-based nanosystem (Ag2S-GOx@BHS NYs) is developed by a novel one-step dual-template (bovine serum albumin (BSA) and cetyltrimethylammonium bromide (CTAB)) synthetic strategy for image-guided therapy. The Ag2S-GOx@BHS NYs can be specifically activated in the tumor microenvironment via a self-feedback mechanism to achieve reactive oxygen species (ROS)-induced multistep therapy. In response to the inherent acidity and H2O2 at the tumor sites, Ag2S-GOx@BHS would accelerate the structural degradation while releasing glucose oxidase (GOx), which could efficiently deplete intratumoral glucose to copious amounts of gluconic acid and H2O2. More importantly, the sufficient H2O2 not only acts as a reactant to generate Ag+ from Ag2S for metal-ion therapy and improves the oxidative stress but also combines with gluconic acid results in the self-accelerating degradation process. Moreover, the released Ag2S nanoparticles can help the Ag2S-GOx@BHS NYs realize the second near-infrared window fluorescence (NIR-II FL) and photoacoustic (PA) imaging-guided precise photothermal therapy (PTT). Taken together, the development of a self-feedback nanosystem may open up a new dimension for a highly effective multistep tumor therapy.

Regulating the level of reactive oxygen species (ROS) in a tumor is an efficient and innovative anticancer strategy. However, the therapeutic efficacy of ROS-based therapies, such as chemodynamic therapy (CDT) and photodynamic therapy (PDT), offers finite outcomes due to the oxygen dependence and limited concentration of hydrogen peroxide (H

Nanosystems responsive to a tumor microenvironment (TME) have recently attracted great attention due to their potential in precision cancer theranostics. However, theranostic nanosystems with a TME-activated consecutive cascade for the accurate diagnosis and treatment of cancer have rarely been exploited. Herein, an activatable theranostic nanosystem (Bi2S3-Ag2S-DATS@BSA-N3 NYs) is designed and constructed on the basis of a one-pot biomineralization method and surface functional modification to improve second near-infrared (NIR-II) fluorescence/photoacoustic (PA) imaging-guided photothermal therapy (PTT)/gas therapy (GT). Based on enhanced penetration and retention (EPR) effect-mediated tumor accumulation, the tumor-overexpressed glutathione (GSH) can accelerate hydrogen sulfide (H2S) generation from the nanoparticles by reacting with the encapsulated diallyl trisulfide (DATS). Meanwhile, the in situ released H2S can be used not only for gas therapy, but also to start the reduction of -N3(-) to -NH2(+), thereby enhancing the tumor-specific aggregation of NYs. As a result, the activatable nanosystems with excellent tumor accumulation and biodistribution could achieve an accurate NIR-II/PA dual-modality imaging for guiding the synergistic anticancer efficacy (PTT/GT). Thus, this work provides a promising TME-mediated continuously responsive strategy for efficient anticancer therapy.

Although nanomedicines have shown high performance in tumor theranostics, their anticancer activity is still limited by the drug delivery capacity, especially lack of targeting capability, poor tumor accumulation, and insufficient tumor deep-penetration. To address this challenge, a high biocompatibility nano-truck (BMP NT) with a two-stage delivery mechanism is designed and developed to achieve the precision therapeutic efficacy of cancer. In view of the enhanced permeability retention (EPR) effect, the surface cleavable layer of BMP NTs can be selectively removed by the overexpressed MMP-2 in a tumor-microenvironment to expose the hydrophobic segments for an induced "braking effect" strategy, resulting in a significant increase in tumor accumulation. Once internalized into cancer cells with the overproduced glutathione (GSH) and H2O2, the BMP NTs undergo the second-stage "unloading process" to release Mn2+ ions and ultrasmall Bi2S3@BSA nanoparticles, and the obtained Mn2+ ions can act as a Fenton-like catalyst for continuously catalyzing the endogenous H2O2 into highly toxic hydroxyl radicals (˙OH) for CDT. The GSH depletion will in turn improve the Mn2+-H2O2 reaction, further enhancing CDT efficiency. Meanwhile, the ultrasmall Bi2S3@BSA endows BMP NTs with excellent photothermal conversion ability to generate local hyperthermia and accelerate the intratumoral Fenton process, thus leading to an effective tumor therapeutic outcome in the synergistic function of CDT/photothermal therapy (PTT). Moreover, the BMP NTs can be used for in situ self-generation magnetic resonance imaging (MRI) and photoacoustic (PA) imaging to guide precision cancer therapy.

Developing new strategies to enhance drug accumulation in the tumor and therapeutic efficacy is of great importance in the field of tumor therapy. Herein, a peanut-like multifunctional nanomedicine (CuS-PGH NMs) made of CuS nanoparticles encapsulated in poly(l-lysine)(PLL)/glucose oxidase (GOx)-hyaluronic acid (HA) shells has been constructed via layer-by-layer (LbL) assembly, and shows good biocompatibility and effective multi-gradient therapy. Because of the enhanced permeability and retention (EPR) effect, the CuS-PGH NMs could significantly enhance the cellular uptake by tumors overexpressing CD44 receptors, which respond to hyaluronidase (HAase)-triggered surface charge conversion. Once internalized by the tumor, GOx was the first to be exposed and could effectively deplete endogenous glucose for starvation therapy, and the excess H2O2 was then converted into highly toxic hydroxyl radicals (˙OH) via a Cu+-mediated Fenton-like reaction for chemodynamic therapy (CDT). Meanwhile, the as-obtained Cu+ ions accompanied the regenerated less-active Cu2+ ions. Interestingly, the high content of H2O2 could, in turn, accelerate Cu2+/Cu+ conversion to promote the Cu+-H2O2 reaction for enhanced chemodynamic therapy (CDT), thereby achieving efficient tumor growth suppression via synergistic starvation/CDT therapy. Subsequently, owing to the strong NIR-II absorption capability of CuS-PGH NMs, effective photothermal tumor ablation of the weakened tumor cells could be realized with the precise guidance of NIR-II PAI. This multi-gradient therapeutic strategy has been demonstrated to have excellent antitumor activity with minimal nonspecific damages, and offers a new avenue to precise tumor therapy.

The “Song of Life (SOL)” is a kind of music therapy in palliative care for addressing emotional and existential needs in terminally ill patients nearing the end of life. Few previous studies focus on objective data analysis methods to validate the effectiveness of psychotherapy therapy for patients’ overall state. This article combines the entropy weighting method (EWM) and the technique for order preference by similarity to the ideal solution (TOPSIS) method to evaluate the effectiveness of SOL music therapy and the treatment satisfaction of the patients and family members. Firstly, the collaborative filtering algorithm (CFA) machine learning algorithm is used to predict the missing ratings a patient might have given to a variable. Secondly, the EWM determines the weights of quality of life, spiritual well-being, ego-integrity, overall quality of life, and momentary distress. Thirdly, the EWM method is applied for the TOPSIS evaluation model to evaluate the patient’s state pre- and post-intervention. Finally, we obtain the state change in patients and recognition based on the feedback questionnaire. The multiple criteria decision making (MCDM) comprehensive evaluation method objectively validated the overall effectiveness of SOL music therapy. Based on MCDM method, we provide a new approach for judging the overall effect of psychological intervention and accurately recommend psychotherapy that fits the symptoms of psychological disorders.

Stimuli-responsive silica nanoparticles are an attractive therapeutic agent for effective tumor ablation, but the responsiveness of silica nanoagents is limited by intrastimulation level and silica framework structure. Herein, a biodegradable hollow SiO

Acetaminophen (APAP) has been widely used for relieving pain and fever, whilst overdose would lead to the occurrence of acute liver failure (ALF). Currently, few effective treatments are available for ALF in clinic, especially for severe, advanced- or end-stage patients who need liver transplantation. Human umbilical cord-derived mesenchymal stem cells (hUMSCs), as one of the mesenchymal stem cells, not only contribute to relieving hepatotoxicity and promoting hepatocyte regeneration due to their self-renewing, multi-differentiation potential, anti-inflammatory, immunomodulatory and paracrine properties, but possess lower immunomodulatory effects, faster self-renewal properties and noncontroversial ethical concerns, which may play a better role in the treatment of ALF. In this work, hUMSCs were rapidly labeled with near-infrared II fluorescent dye-modified melanin nanoparticles (MNP-PEG-H2), which could realize long-term tracking of hUMSCs by NIR-II fluorescent (FL)/photoacoustic (PA) dual-modal imaging and could visualize hUMSC-based liver regeneration in ALF. The nanoparticles exhibited good dispersibility and biocompatibility, high labeling efficiency for hUMSCs and excellent NIR-II FL/PA imaging performance. Moreover, the MNP-PEG-H2 labeled hUMSCs could be continuously traced in vivo for up to 21 days. After intravenous delivery, the NIR-II FL and PA images revealed that labeled hUMSCs were able to engraft in the injured liver and repair damaged tissue in ALF mice. Therefore, the hUMSCs labeled with endogenous melanin nanoparticles solve the key tracing problem of MSC-based regenerative medicine and realize the visualization of the treatment process, which may provide an efficient, safe and potential choice for ALF.

This thesis conducts analyses, and proposes and investigates inverter operation control system on several different AC and DC microgrids. The coordination and control of the inverter operation in microgrids are crucial to integrate different renewable energy in power systems. This thesis digs into different problems occur in the microgrid to accommodate multiple inverters while sustaining the stability and reliability of the system. Firstly, a centralized control strategy within an energy management system (EMS) are proposed for an AC based microgrid consists of PV, battery, fuel cell and microturbine. For this inverter-interfaced AC microgrid, parallel operation of all the inverters during both grid-connected and islanded operations is realized through a coordination control in the EMS with two different model predictive control (MPC) based control modes for inverters: current control mode (CCM) and voltage control mode (VCM). Several case studies are carried out through simulations with detailed analysis, and they validate that the proposed centralized control strategy can handle different operations. Secondly, the system frequency analysis of the islanded condition of an inverter-interfaced AC microgrid is conducted. A combined centralized and decentralized control strategy is proposed using MPC based inverter control. A frequency model is incorporated in the EMS for coordination control among different distributed generation (DG) units. To test scenarios are studied through simulations. These simulations illustrate the frequency problems and prove that the proposed combined centralized and decentralized control strategy can handle different conditions in islanded condition. Finally, the analysis and study of inverter operation and control extend to DC based microgrids to investigate harness the excess wind energy in poultry farms. A double-inverter configuration between DC bus and AC bus in the DC based microgrid is proposed. A double-mode MPC algorithm (VCM and CCM) and a control strategy in the EMS is proposed to handle the two inverters’ operation. Several simulation tests are analyzed, and they prove the effectiveness of the control algorithm and the double-inverter operation principle. Doctor of Philosophy (EEE)

Ultrasmall melanin nanoparticles (MNPs) have great application potential in medical imaging, owing to its satisfactory biodegradation, intrinsic photoacoustic (PA) property and natural chelating ability with metal ions for magnetic resonance imaging (MRI). Because of its ultrasmall particle size, it was easily metabolized by the kidney, but had relatively limited tumor retention according to our previous study. To further improve the intensities of MRI and PA signals for precise diagnosis, it is vital to enhance its tumor accumulation and prolong the retention time. In this study, we developed a matrix metalloproteinase-2 (MMP-2) activatable nanoprobe (PEG-PepMMP2-MNP-Gd), which was composed of water-insoluble gadolinium-chelated melanin (MNP-Gd), MMP-2 cleaved peptide and enzymatic detachable polyethylene glycol (PEG). In the presence of MMP-2 activity, PEG-coating on the surface was peeled off and the "hidden" hydrophobic segment was then exposed, which initiated the aggregation and size increase of nanoprobes. We demonstrated that the hydrodynamic size of the MMP-2 activatable nanoprobe increased from 17.1 nm to 90.2 nm after in vitro incubation with MMP-2. Moreover, the in vivo T1-weighted MRI and PA signals in tumors were both dramatically enhanced and extended after the PEG-PepMMP2-MNP-Gd nanoparticles were intravenously injected into mice. This could be attributed to the changed size selectively activated by highly expressed MMP-2 in tumors, and allowing nanoparticles to possess higher tumor accumulation and longer retention. In short, MMP2-initiated size-changeable PEG-PepMMP2-MNP-Gd could meet the paradoxical demand for size-leading permeability and retention in solid tumors, suggesting its promising applications as a highly efficient MRI/PA contrast agent for precise tumor diagnosis.

Melanin as an endogenous biomolecule is widely applied in the biomedical field, focusing especially on diagnostic imaging and photothermal therapy in cancer treatment. However, its photothermal conversion efficiency, a benchmark in tumor photothermal therapy (PTT), often could not satisfy PTT requirements to some degree, and this greatly influenced its use in photothermal cancer therapy. As for fluorescence imaging, a small-molecule NIR dye as a fluorescence probe is easily and rapidly metabolized in vivo, resulting in low accumulation in a tumor. To overcome these problems, we attempt to use melanin as a carrier to conjugate a fluorochrome, a recombinant small NIR dye IR820 nanoplatform containing melanin (MNP-PEG-IR820 abbreviated to MPI). The addition of IR820 not only enhances the PTT ability of the nanoplatform, but also endows the material with excellent NIR fluorescence behavior. Most importantly, the integration of fluorescence dye and melanin improves the circulation and stability performance of IR820 while reducing its toxicity in vivo, owing to the protectivity of melanin. Thus, the diagnostic capability is enhanced. Meanwhile, the behavior of the nanoplatform in PAI/PTT is significantly improved. The in vitro investigations reveal that the MPI NPs afford a potent PTT effect and ideal resistance to photobleaching. After intravenous injection, the MPI NPs display effective PTT tumor eradication in a Hep-2 tumor bearing mouse model with excellent dual NIR-I fluorescence/photoacoustic imaging guided phototherapy. Hence, our work shows the potential of MPI NPs as nano-theranostics for biomedical application to laryngocarcinoma.

Xi Yang,1,2,* Bo Fan,3,* Wei Gao,4,5,* Liping Li,2 Tingting Li,3 Jinghua Sun,2 Xiaoyang Peng,2 Xiaoyan Li,2 Zhenjun Wang,2 Binquan Wang,4,5 Ruiping Zhang,2 Jun Xie1 1Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi, People’s Republic of China; 2Imaging Department of Shanxi Provincial Cancer Hospital, Shanxi Medical University, Imaging Department of Shanxi Medical University, Taiyuan, Shanxi, People’s Republic of China; 3Department of Pharmacy, School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, People’s Republic of China; 4Department of Otolaryngology, Head and Neck Surgery, The First Hospital, Shanxi Medical University, Taiyuan, Shanxi, People’s Republic of China; 5Shanxi Key Laboratory of Otorhinolaryngology Head and Neck Cancer, Taiyuan, Shanxi, People’s Republic of China *These authors contributed equally tothis work Background: Effective endosomal escape is still a critical bottleneck for intracellular delivery of small interfering RNAs (siRNAs) to maximize their therapeutic efficacy. To overcome this obstacle, we have developed a photothermally triggered system by using the near-infrared (NIR) irradiation to achieve “on-demand” endosomal escape and subsequent siRNA release into cytoplasm. Materials and methods: Herein, the poly-l-lysine (PLL) was successfully conjugated with melanin to obtain melanin-poly-l-lysine (M-PLL) polymer as a siRNA vehicle. The melanin was an efficient photothermal sensitizer, and the positive pendant amino groups of PLL could condense siRNAs to form stable complexes by electrostatic interactions. Results and discussion: Inspired by its excellent photothermal conversion efficiency, the melanin was first involved in the siRNA delivery system. Confocal laser scanning microscopic observation revealed that after cellular uptake the photothermally induced endosomal escape could facilitate siRNAs to overcome endosomal barrier and be delivered into cytoplasm, which resulted in significant silence in the luciferase expression over the NIR- and melanin-free controls. Moreover, the anti-survivin siRNA-loaded M-PLL nanoparticles displayed great inhibitory effect on 4T1 tumor growth in vitro and in vivo. Conclusion: These findings suggest that the M-PLL-mediated siRNA delivery is a promising candidate for therapeutic siRNA delivery and shows improved effect for cancer therapy via enhanced endosomal escape. Keywords: melanin, poly-l-lysine, photothermal effect, endosomal escape, siRNA delivery

Endogenous biomaterials in organisms, with native biocompatibility and biodegradability, appear more advantageous in the development of nanoscale diagnostic and therapeutic systems for future clinical translation. Herein, a novel tumor-targeting Magnetic Resonance Imaging (MRI) contrast agent was developed based on Mn2+-chelating ultrasmall water-soluble melanin nanoparticles (MNP-PEG-Mn). The nanoparticles, with a size of about 5.6 nm, presented high chelation stability and showed negligible cytotoxicity as estimated by MTT assay. Moreover, the r1 longitudinal relaxivity (20.56 mM−1 s−1) of MNP-PEG-Mn was much higher than that of Gadodiamide (6.00 mM−1 s−1), which is a clinically approved MRI contrast agent. In vivo MRI experiments revealed excellent tumor-targeting specificity after tumor-bearing mice were intravenously injected with MNP-PEG-Mn. Additionally, MNP-PEG-Mn could be excreted via renal and hepatobiliary pathways with negligible toxicity to body tissues. These preliminary results indicated the clinically translatable potential of MNP-PEG-Mn as a T1 MRI contrast agent for tumor-targeted imaging.

In order to provide sustainable clean energy for the growing demand of electrical power in off-grid districts in Asia Pacific and South-East Asia through renewable energy sources (RESs) integration, ENGIE and Schneider Electric have made a partnership to join the Renewable Energy Integration Demonstration-Singapore (REIDS) initiative, the world largest microgrid demonstrator in the tropical area, to demonstrate state-of-the-art multi-fluid microgrid solution. Currently being constructed on Semakau Island, South of Singapore, the demonstration platform will enable ENGIE and Schneider Electric to integrate and test their solution that will provide a package of services including electricity, mobility, and clean cooking. Key innovations of the project include: The scalability and ability to start from both greenfield system (electrification of remote districts) and brownfield system (with existing equipment); A multi-fluid optimization module to enhance synergies between different technologies (renewable production, consumption, flexible loads, storage, H2 chain, and biogas chain) to provide cheap and reliable electricity with low environmental impact; A power control module allowing up to 100% intermittent RESs penetration in the power thanks to the cutting edge technology of virtual synchronous generator; The integration of an H2 chain for energy storage and mobility purposes; The integration of biogas technology for waste treatment and clean cooking. Promising results have already been observed in both companies’ research centers on different technology bricks. These different bricks are currently being integrated into this microgrid for the first time to be verified for the feasibility and stability of the complete solution. Different use cases for both technical and commercial purposes have been designed and will be tested in the microgrid. Different tests and reports on this multi-fluid microgrid on Semakau Island will enable us to optimize the solution to be suitable for the tropical conditions of South-East Asia, thus promoting the integration of renewable energy for all.

In the gradient method, soil heat flux density at a known depth G is determined as the product of soil thermal conductivity λ and temperature T gradient. While measuring λ in situ is difficult, many field studies readily support continuous, long-term monitoring of soil T and water content θ in the vadose zone. In this study, the performance of the gradient method is evaluated for estimating near-surface G using modeled λ and measured T. Hourly λ was estimated using a model that related λ to θ, soil bulk density ρb, and texture at 2-, 6-, and 10-cm depths. Soil heat flux Gm was estimated from modeled λ and measured T gradient (from thermocouples). The Gm results were evaluated with heat flux data GHP determined using independent measured λ and T gradient from heat-pulse probes. The λ model performed well at the three depths with 3.3%–7.4% errors. The Gm estimates were similar to GHP (agreed to within 15.1%), with the poorest agreement at the 2-cm soil depth, which was caused mainly by the relatively greater variability in ρb. Accounting for temporal variations in ρb (with core method) improved the accuracies of λ and Gm at the 2-cm depth. Automated θ monitoring approaches (e.g., time domain reflectometry), rather than gravimetric sampling, captured the temporal dynamics of near-surface λ and G well. It is concluded that with continuous θ and T measurements, the λ model–based gradient method can provide reliable near-surface G. Under conditions of soil disturbance or deformation, including temporally variable ρb, data improves the accuracy of G data.

Summary Soil-surface heat flux (G0), an important component of the surface energy balance, is often determined by summing soil heat flux (Gz) at a depth (z) below the surface and the rate of change in soil heat storage (ΔS) in the layer above z. The soil heat flux Gz is commonly measured with passive heat flux plates, but self-calibrating plates or additional corrections are required to obtain accurate data. In some cases, ΔS is neglected because of the difficulty of monitoring the dynamics of volumetric heat capacity (C), which might lead to erroneous estimates of G0. To overcome these limitations, we introduce the heat-pulse method for measuring G0 with a multi-needle heat-pulse probe (HPP). Soil temperature (T) distribution, thermal conductivity (λ) and C of the 0–52-mm layer were measured hourly on five consecutive days with an 11-needle HPP, and Gz at 50-mm depth (G50) and ΔS of the 0–50-mm layer (ΔS0–50) were determined by the gradient and calorimetric methods, respectively. Independent measurements of G50 with a self-calibrating heat flux plate and ΔS0–50 calculated with the de Vries model C were used to evaluate the HPP data. With reliable G50 and ΔS0–50 measurements, the HPP-based G0 data agreed well with those estimated from the independent method (with a mean absolute difference of 4.5 W m−2). Supporting measurements showed that determining Gz at the 50-mm depth minimized the likelihood of errors from evaporation below the measurement depth. The multi-needle HPP provides a reliable way to determine G0 in situ. Additional analysis demonstrated that by reducing the number of needles from 11 to 5, the datalogging requirement was reduced by half and G0 was still determined with acceptable accuracy. Highlights Heat flux at the soil surface (G0) was monitored by the heat-pulse technique. A multi-needle heat-pulse probe (HPP) was used to measure subsurface soil heat flux (Gz) and heat storage concurrently. Appropriate measurement depths of Gz were determined to minimize the effects of subsurface latent heat sink on G0. A simplified calculation reduced the datalogging requirement of the multi-needle HPP.

Melanin nanoparticles are of great importance in biomedicine. They have excellent affinity for metallic cations, especially paramagnetic ions, which has sparked interest in their application in the development of magnetic resonance imaging (MRI) contrast agents. In this work, we prepared ultrasmall water-soluble melanin nanoparticles, and investigated the binding properties of melanin toward different metal cations (Gd3+, Mn2+, Fe3+ and Cu2+), and compared their physicochemical properties and the MRI contrast enhancement ability in various metal chelated forms (MNP-PEG-M) in vitro and in vivo. We show that the saturation binding numbers of Gd3+, Mn2+, Fe3+ and Cu2+ per MNP-PEG were 49, 59, 69 and 62, respectively. MNP-PEG-Gd, MNP-PEG-Mn, MNP-PEG-Fe and MNP-PEG-Cu exhibited the maximum r1 relaxivities at the loading mass ratios of Gd3+ : MNP = 1 : 1, Mn2+ : MNP = 0.5 : 1, Fe3+ : MNP = 0.1 : 1 and Cu2+ : MNP = 0.1 : 1, corresponding to 49, 57, 54 and 51 chelated metals per MNP-PEG, respectively. The maximal per metal ion r1 relaxivity values were 61.9, 48.7, 11.1 and 9.7 mM−1 s−1 for MNP-PEG-Gd, MNP-PEG-Mn, MNP-PEG-Fe and MNP-PEG-Cu at 1.5 T, respectively. MNP-PEG-Gd and MNP-PEG-Fe presented larger sizes (6.9 nm and 5.8 nm) than MNP-PEG-Mn and MNP-PEG-Cu (3.4 nm and 3.7 nm), all featuring excellent solubility, high stability and ultrasmall size. A significant in vivo MRI signal enhancement in tissues was observed for all MNP-PEG-M after intravenous injection in mice, and these nanoparticles were excreted through renal and hepatobiliary pathways. In agreement with their r1 relaxivity values, MNP-PEG-Gd and MNP-PEG-Mn showed a significantly greater in vivo tissue maximum enhancement than MNP-PEG-Fe and MNP-PEG-Cu. This study could yield valuable insight into the development of a new class of MRI contrast agents.

Multimodality therapy under imaging-guidance is significant to improve the accuracy of cancer treatment. In this study, a photoacoustic imaging (PAI)-guided anticancer strategy based on poly-l-lysine functionalized melanin nanoparticles (MNP-PLL) was developed to treat laryngeal squamous cell carcinoma (LSCC). As a promising alternative to traditional therapies for LSCC, MNP-PLL/miRNA nanoparticles were combined with photothermal ablation against primary tumors and miR-145-5p mediated gene therapy for depleting the metastatic potential of tumor cells. Furthermore, taking advantage of the photoacoustic properties of melanin, PAI guided therapy could optimize the time point of NIR irradiation to maximize the efficacy of photothermal therapy (PTT). The in vitro and in vivo results proved that the combined treatments displayed the most significant tumor suppression compared with monotherapy. By integrating thermo-gene therapies into a theranostic nanoplatform, the MNP-PLL/miR-145-5p nanoparticles significantly suppressed the LSCC progression, indicating their great potential use for cancer therapy.

Multi-modal imaging-guided photothermal therapy (PTT) has aroused extensive attention in biomedical research recently because it can provide more comprehensive information for accurate diagnosis and treatment. In this research, the manganese ion chelated endogenous biopolymer melanin nanoparticles were successfully prepared for magnetic resonance (MR)/photoacoustic (PA) dual-modal imaging-guided PTT. The obtained nanoparticles with an ultrasmall size of about 3.2 nm exhibited negligible cytotoxicity, high relaxivity for MRI, an excellent photothermal effect and PA activity. Moreover, in vivo MRI and PAI results all demonstrated that the nanoparticles began to diffuse in the blood after intratumoral injection into tumor-bearing mice and could spread throughout the whole tumor region at 3 h, indicating the optimal treatment time. The subsequent photothermal therapy of cancer cells in vivo was carried out and the result showed that tumor growth could be effectively inhibited without inducing any observed side effects. Besides, melanin as an endogenous biopolymer has native biocompatibility and biodegradability, and it can be excreted through both renal and hepatobiliary pathways after treatment. Therefore, the melanin-Mn nanoparticles may assist in better indicating the optimal treatment time, monitoring the therapeutic process and enhancing the therapeutic effect and showed great clinical translation potential for cancer diagnosis and therapy.

Soil heat flux is an important component of the energy balance at the land surface. Heat flux plates have been used widely to measure soil heat flux, but suffer from errors such as heat flow distortion and soil–plate contact resistance. The Philip correction and self-calibrating heat flux plates have been applied to minimize measurement errors. The objectives of this study were to evaluate the effectiveness of heat flux plate correction methods and to introduce improved approaches for applying these methods under field conditions. Soil heat flux at a depth ( z ) below the surface ( G z ) was measured with conventional and self-calibrating plates buried at 2, 6, and 10 cm in a bare soil. Adjacent to the soil heat flux plates, soil thermal conductivity ( λ s ) and temperature gradients were measured simultaneously with heat-pulse sensors, allowing G z to be determined with the gradient method. The gradient method values were used as a standard to evaluate the performance of the heat flux plates. Temporal λ s values were also estimated from soil sand content, bulk density and water content using a thermal conductivity model. At the 6- and 10-cm depths, the conventional plates underestimated G z by 4.3–10.2 W m −2 due to heat flow distortion errors resulting from a mismatch between λ s and plate thermal conductivity ( λ p ). When the Philip correction was applied, both the measured and modeled λ s values improved the accuracy of conventional heat flux plates. However, the modeling approach simplified the procedure for obtaining λ s . The self-calibrating plate effectively corrected G z errors associated with heat flow distortion (accurate to within 6.4 W m −2 ) at the 6 cm and 10 cm depths. At the 2 cm depth, both types of plates produced erroneous G z data, which were attributed to alterations in the thermal field and heat flux pattern around the plates due to blocking convective heat and water transfer. We also demonstrated that the heating process of the self-calibrating plate could bias G z data by disturbing the heat flow field around the plate. Voltage signals during and shortly after self-calibration should be discarded from data analysis. With these corrections, heat flux plates can provide an effective method for measuring soil heat flux.

In this work, we designed a simple hydrolysis reaction to study the chemical roles of anions with different chemoaffinity abilities to iron ions on the crystallization of FeOOH. FeOOH products with different morphologies and sizes can be crystallized by using commercial iron salts such as FeSO4, FeCl2, FeCl3 and Fe(NO3)3. Their crystallization mechanisms can be evidenced in terms of hard–soft acid–base theory, which can control the chemical reaction and crystallization process. Herein, FeOOH particles with high electroactivity were successfully synthesized at 80 °C via the use of a single-source of iron salt in each corresponding experiment without adding any other reagents. The as-obtained FeOOH samples exhibit high specific capacitances of 441.2, 385.7, 577.3 and 619.6 F g−1, which show good potential to be candidates as high performance electrode materials for supercapacitors. Moreover, this facile synthesis method provides a huge opportunity for future practical applications of supercapacitors.

In the present work, size-tunable Fe2O3 microspindles were crystallized by a simple feasible ethylenediamine (EN) ligand-controlled hydrothermal approach. The size of Fe2O3 microspindles can be controlled from several hundreds of nanometers to above 1 micrometer. Fe2O3 particles with spindle-like structure can be controlled well via the assistance of EN. A clear growth pathway of the EN-assisted synthesis of Fe2O3 microspindles was illustrated by us. As-obtained Fe2O3 microspindles in different sizes exhibit high specific capacitance values of 558.7, 496.6, 504.7 and 271.0 F g−1, which are much higher than previous reported results. The smaller size of Fe2O3 microspindles can lead to higher specific capacitance.

Endogenous biomaterials in organisms, with native biocompatibility and biodegradability, appear more advantageous in the development of nanoscale diagnostic and therapeutic systems for future clinical translation. Herein, a novel tumor-targeting Magnetic Resonance Imaging (MRI) contrast agent was developed based on Mn

Fe ( OH )x (x = 2, 3) colloidal aggregations were synthesized at room temperature via a reduction and hydrolysis of FeCl 3⋅6 H 2 O on microscale Cu 2 O octahedron, which functions as a self-sacrifice template. We herein proposed the growth of Fe ( OH )x colloidal aggregation by redox etching Cu 2 O octahedron while two critical reactions of both redox and precipitation were well employed in this work. As-synthesized Fe ( OH )x samples exhibited high specific capacitance of 242.7 F/g, which was higher than those available data of iron oxides and hydroxides.