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The trivalent chromium (Cr) leached from stainless steel slag can be oxidized into hexavalent Cr with strong toxicity in the natural storage process, thus causing severe pollution to the surrounding soil, water, and atmosphere. Currently, the toxicity hazards caused by high Cr concentrations in plants, animals, and humans have attracted widespread attention from across the world. In this study, an overview is presented regarding the occurrence mode, leaching mechanism, and influencing factors for the presence of Cr in the soil of stainless steel slag under natural landfilling conditions. Meanwhile, a summary is made for the research progress in Cr absorption, transport, and accumulation in the soil–plant system. Besides, allowing for the toxicity and detrimental effect of Cr(vi) in the soil as well as the application of biological and chemical methods for the remediation of Cr(vi)-contaminated soil, a review is conducted on the approach to recycling Cr from stainless steel slag and the application of chemical remediation and biological methods to remedy Cr-containing soil. Finally, a discussion is conducted about the transfer and transformation behavior of Cr in soil–plant system, the practical application of soil remediation technology and the prospect of research in this field.

Nanophotonic engineering provides an effective platform to manipulate thermal emission on-demand, enabling unprecedented heat management superior to conventional bulk materials. Amongst a plethora of nanophotonic structures, symmetries play an important role in controlling radiative heat transfer in both near-field and far-field. In physics, broken symmetries generally increase the degree of freedom in a system, enriching the understanding of physical mechanisms and bringing many exciting opportunities for novel applications. In this review, we discussed the underlying physics and functionalities of nanophotonic structures with broken geometrical symmetries, engineered mode symmetries, and broken reciprocity for the control of thermal emission. We overview a variety of physical phenomena and interesting applications, and provide the outlook for future development.

All-dielectric metasurfaces based on ferrimagnetic iron garnets are a promising platform for realizing ultra-compact magneto-optical (MO) devices with low loss. However, ferrimagnetic iron garnets are notorious for being intractable on fine nanopatterning, hindering the faithful fabrication of designed nanostructures. In this regard, it is important to assess the influence of fabrication imperfections on the performance of MO metasurfaces. Here, we investigate the optical properties of a MO metasurface with structural imperfections. As the most typical fabrication error, we studied the impact of the tilted side walls of cylindrical garnet disks that constitute the metasurfaces. We found that tilting the side walls drastically degrades the MO response and light transmittance of the device. Nevertheless, it was also found that the performance can be recovered by optimizing the refractive index of the material covering the upper half of the nanodisks.

In this article, a 1-MHz-regulated DCX (RDCX) with single transformer is proposed for high-power-density high-efficiency 48–12 V dc–dc conversion. In the proposed converter, a dc transformer (DCX) works at fixed switching frequency to realize isolation and output power conversion and an auxiliary pulsewidth modulation (PWM) converter is applied to realize voltage regulation. The auxiliary dc–dc is fed from the auxiliary winding of the transformer and its output is in series with the input dc source. The output regulation is achieved by regulating the output voltage of auxiliary dc–dc converter. Furthermore, only a small portion of power is dealt by the auxiliary PWM dc–dc converter. Thus, the total efficiency is a little bit lower than the DCX and higher than that of conventional two-stage solution. The operation principle and the design guidelines of the proposed RDCX are presented in this article. A 360 W 40–60 V/12 V dc–dc prototype is built to verify the theoretical analysis and design guidelines. In the prototype, 9.1% of load power is dealt by the auxiliary dc–dc at nominal 55 V input voltage and, at worst case, which happens rarely and the duration is short, 50% of load power is dealt by the auxiliary dc–dc stage. Finally, 97.3% peak efficiency is achieved.

Developing cryogen-free multicolor photodetectors is still a challenge for fiber optic communication systems, and their integration with optoelectronics is essential for large-scale use. In this pa...

AIM: To understand the factors associated with negative conversion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, targeted surveillance and control measures can be taken to provide scientific basis for the treatment of the disease and to improve the prognosis of the disease. METHODS: Using the method of retrospective cohort study, we collected the data of Coronavirus Disease 2019 (COVID-19) patients in Tongji Hospital of Wuhan, China from 10 January to 25 March, 2020. Among the data of 282 cases, 271 patients, according to whether the negative conversion happened, were divided into negative conversion group and control group. We made the quantitative variables into classification; Chi-square test single-factor and Cox regression were used in univariate analysis and extracted 30 meaningful variables, then through the collinearity diagnosis, excluded the existence of collinear variables. Finally, 22 variables were included in Cox regression analysis. RESULTS: The gender distribution was statistically significant between two groups (p < 0.05). While in the negative conversion group, the patients of non-severe group occupied a large proportion (p < 0.001). The median time for the negative conversion group was 17 days, and at the end of the observation period, the virus duration in control group was 24 days (p < 0.05). A total of 55 variables were included in univariate analysis, among which 30 variables were statistically different between the two groups. After screening variables through collinearity diagnosis, 22 variables were included in the Cox regression analysis. Last, lactate dehydrogenase (LDH), age, fibrinogen (FIB), and disease severity were associated with negative conversion of SARS-CoV-2 RNA. CONCLUSION: Our results suggest that in the treatment of COVID-19, focus on the age of more than 65 years old, severe, high level of LDH, FIB patients, and take some targeted treatment, such as controlling of inflammation, reducing organ damage, so as to provide good conditions for virus clearance in the body.

Benefited from the well-known Mie resonance, a plethora of physical phenomena and applications are attracting attention in current research on dielectric-based nanophotonics. High-index dielectric metastructures are favorable to enhance light-matter interaction in nanoscale with advantages such as low loss, optical magnetism, and multipolar responses, which are superior to their plasmonic counterpart. In this review, we highlight the important role played by Mie resonance-based multipolar and multimodal interaction in nanophotonics, introducing the concept of “multipole and multimode engineering” in artificially engineered dielectric-based metastructures and providing an overview of the recent progress of this fast-developing area. The scope of multipole and multimode engineering is restricted not only in multipolar interferences of meta-atom and meta-molecule but also in the nontrivial intermodal coupling (Fano resonance and bound states in the continuum), in the collective mode and the surface lattice mode appearing via periodic meta-lattices and aperiodic meta-assembly, in chiral enhancement via chiral and achiral dielectric metastructures, and in Mie resonance-mediated hybrid structures (Mie-plasmon and Mie-exciton). Detailed examples and the underlying physics of this area are discussed in-depth, in order to lead the multifunctional metastructures for novel applications in the future.

Long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) has been identified as a regulatory molecule in angiogenesis. The goal of this study was to illustrate how MEG3 affects the angiogenesis of vascular endothelial cells. Expression of MEG3, miR-147 and intracellular cell adhesion molecule-1 (ICAM-1) in human microvascular endothelial cell line (HMEC-1) was altered by transfection, then cell viability, apoptosis, migration, tube formation, as well as the correlation among MEG3, miR-147 and ICAM-1 were explored. MEG3 was down-regulated during tube formation of HMEC-1 cells. MEG3 expression suppressed cells viability, migration and tube formation, while it induced apoptosis. MEG3 could bind with miR-147 and repress miR-147 expression. MiR-147 induced ICAM-1 expression, and contained ICAM-1 target sequences. The anti-atherogenic actions of MEG3 were inhibited by miR-147, and the anti-atherogenic actions of miR-147 suppression were also inhibited when ICAM-1 was overexpressed. Further, ICAM-1 overexpression showed activated roles in Wnt/β-catenin and Jak/Stat signaling pathways. In low-density lipoprotein receptor (Ldlr)−/− mice, MEG3 overexpression reduced CD68+, CD3+ and ICAM-1 areas in lesions and increased collagen content. MEG3 inhibited HMEC-1 cell growth, migration and tube formation. The anti-atherogenic actions of MEG3 might be mediated via sponging miR-147, and thereby repressing the expression of ICAM-1.

The traditional ideological and moral education evaluation mechanism in colleges and universities faces many challenges. Among them, the traditional ideological and political theory course evaluation mechanism is difficult to solve the contradiction between the teaching content of the ideological and political theory course and the ideological knowledge of the educated, and the test scores of the ideological and political theory course are difficult to measure the level of students’ ideological awareness that has become a prominent problem. The evaluation mechanism of ideological and political education in colleges and universities based on deep learning technology can play a role in the formative evaluation and consequential evaluation of courses, thus forming a new mechanism for evaluating ideological and political education in colleges and universities, and further improving the effectiveness of ideological and political education.

Aiming at the problems of diverse hardware platforms, poor compatibility, single energy collection, and so on existing in the perception terminal, this paper designs and studies the intelligent Internet of Things (IoT) terminal for integrated energy precise regulation. Firstly, we build a unified hardware platform for embedded terminals, adopt the modular idea, design different functional modules by modularization, and configure different expansion modules according to the application needs, realizing the hardware modularization and reconfigurable design of intelligent IoT terminals. Secondly, to meet the needs of integrated energy service, software functions such as integrated energy data collection, energy efficiency analysis management, demand response management, and control strategy operation management are developed. Meanwhile, a novel GRU-DNN algorithm is proposed for accurate load forecasting under different conditions. Compared with other load forecasting algorithms, the GRU-DNN algorithm has better accuracy and robustness.

Passive daytime radiative cooling (PDRC) materials, that strongly reflect sunlight and emit thermal radiation to outer space, demonstrate great potential in energy-saving for sustainable development. Particularly, polymer-based PDRC materials, with advantages of easy-processing, low cost, and outstanding cooling performance, have attracted intense attention. However, just like other polymer devices (for example polymer solar cells) working under sunlight, the issue of durability related to mechanical and UV properties needs to be addressed for large-scale practical applications. Here, a spider-silk-inspired design of nanocomposite polymers with potassium titanate (K

Chiral plasmonic metamaterials have shown very interesting possibilities as chiral optical absorbers for circularly polarized light detection, as their optical response can be manipulated through t...

Argon oxygen decarbonization (AOD) slag refers to a byproduct of stainless steel (SS) production, which has caused considerable environmental stress. Finding an effective approach for recycling AOD slag is essential to environmental safety. In this work, batch leaching tests were carried out to explore the leaching behavior of AOD slag and soil. Pot experiments was conducted to analyze the fertilization effect of AOD slag for tall fescue (Festuca arundinacea Schreb) planting. The plant height, biomass, total root length (TRL), root surface area (RSA), root tips (RT), root hairs (RH)), chlorophyll content, malondialdehyde (MDA) content, and antioxidant enzyme activities of the tall fescue seedlings were measured. As indicated from the results, adding AOD slag into soil increased soil pH. The leaching concentration of Ca, Si, Al, Cr of the AOD slag was higher than the original soil, while that of Mg, Mn, and Fe was lower. Low addition rate (≤1%) of AOD slag fertilization was good for plant height, biomass, root growth, and chlorophyll synthesis, whereas high addition rate (≥2%) exerted an opposite effect. Elevating the rate of AOD slag fertilization increased the Cr accumulation in the tall fescue seedling that aggravated damage of reactive oxygen species (ROS). When the AOD slag fertilization was at a low rate (≤1%), ROS scavenging was attributed to the synergistic effects of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) defense systems, while at a high rate (≥2%) of AOD slag fertilization, scavenging of excessive ROS could be mainly due to the CAT defense system.

We intend to evaluate the differences of the clinical characteristics, cytokine profiles and immunological features in patients with different severity of COVID-19, and to develop novel nomograms based on inflammatory cytokines or lymphocyte subsets for the differential diagnostics for severe or critical and non-severe COVID-19 patients. We retrospectively studied 254 COVID-19 patients, 90 of whom were severe or critical patients and 164 were non-severe patients. Severe or critical patients had significantly higher levels of inflammatory cytokines than non-severe patients as well as lower levels of lymphocyte subsets. Significantly positive correlations between cytokine profiles were observed, while they were all significantly negatively correlated with lymphocyte subsets. Two effective nomograms were developed according to two multivariable logistic regression cox models based on inflammatory cytokine profiles and lymphocyte subsets separately. The areas under the receiver operating characteristics of two nomograms were 0.834 (95% CI: 0.779-0.888) and 0.841 (95% CI: 0.756-0.925). The bootstrapped-concordance indexes of two nomograms were 0.834 and 0.841 in training set, and 0.860 and 0.852 in validation set. Calibration curves and decision curve analyses demonstrated that the nomograms were well calibrated and had significantly more clinical net benefits. Our novel nomograms can accurately predict disease severity of COVID-19, which may facilitate the identification of severe or critical patients and assist physicians in making optimized treatment suggestions.

Objective. To compare the difference of inflammatory cytokines and lymphocyte subsets between deceased patients and survivors with COVID-19. Methods. This retrospective study included 254 confirmed patients from 10 January to 11 March, 2020, at Tongji Hospital of Wuhan, China. Laboratory and immunologic features were collected and analyzed, and the main outcomes focused on inflammatory cytokines and lymphocyte subsets. Results. A trend of markedly higher levels of inflammatory cytokines as well as lower lymphocyte subset levels in deceased patients was observed compared with survivors. ROC curve analyses indicated that inflammatory cytokines and the decrease levels of T cell, Th (helper T cells) cell, Ts (suppressor T cells) cell, B cell, and NK cell along with Th/Ts ratio increase could be used to predict the death of COVID-19. Multivariate analyses showed that higher levels of IL-6, IL-8, and IL-10 remained significantly correlated with shorter survival time and that the amount of Ts cells was negatively associated with the possibility of death in COVID-19 patients. In conclusion, SARS-CoV-2 would cause lymphopenia and result in decreased lymphocyte subset cells, particularly in Ts cell counts, which further induces hyperinflammatory response and cytokine storm. IL-6, IL-8, IL-10, and Ts cell might be independent predictors for the poor outcome of COVID-19.

Hot electron photodetection (HEPD) excited by surface plasmon can circumvent bandgap limitations, opening pathways for additional energy harvesting. However, the costly and time-consuming lithography has long been a barrier for large-area and mass production of HEPD. In this paper, we proposed a planar and electron beam lithography-free hot electron photodetector based on the Fabry-Pérot (F-P) resonance composed of Au/MoS

An ultrathin near-perfect MoSe

A chiral metamaterial perfect absorber is theoretically studied and presented for plasmon-induced polarization-sensitive photochemistry involving hot electrons. The g-factor of RateHE reaches to 1.52, close to the theoretical upper limit of 2.

Argon oxygen decarburization (AOD) slag is the by-product of the stainless steel refining process, which has caused considerable environmental stress. In this work, the utilization of AOD slag as mineral fertilizer for alfalfa (Medicago sativa L.) and perennial ryegrass (Lolium perenne L.) planting were investigated by pot experiments. The morpho-physiological parameters of biomass, plant height, root morphology and the biochemical parameters of malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase (POD) activity, and chlorophyll were measured. The accumulation of chromium in plants was also determined for an environmental safety perspective. It was found that low rates (≤0.5 wt.% for alfalfa and ≤2 wt.% for perennial ryegrass) of AOD slag fertilization are beneficial to the growth of these two plants. However, the soil enrichment with higher AOD slag amounts resulted in the reduction of biomass, plant height, and root growth. Compared with the alfalfa, the perennial ryegrass showed higher tolerance for AOD slag fertilization. The toxicity of the utilization of AOD slag as mineral fertilizer for perennial ryegrass planting is slight. Health risks induced by the consumption of the alfalfa grown on the soil with high AOD slag rates (≥8 wt.%) were detected.

The ability to dynamically tune the self-assembled structures of nanoparticles is of significant interest in the fields of chemistry and material studies. However, it continues to be challenging to dynamically tune the chiral superstructures of nanoparticles and actively switch the chiral optical properties thereof. Here, we dynamically controlled a gold nanorod 3D chiral plasmonic superstructure (a stair helix with a pinwheel end view) templated by a DNA origami supramolecular polymer, using DNA-toehold-mediated conformational change in the DNA template. The gold nanorod chiral plasmonic helix was controllably reconfigured between a tightly folded state (with a small inter-rod angle) and an extended state (with a wide inter-rod angle) of the same handedness, or between two mirror-image-like structures of opposite handedness. As a result, the chiral plasmonic properties of the gold nanorod helix superstructures, in terms of the circular dichroism amplitude, peak response frequency, and signature of chirality, were actively switched upon the DNA-guided structural reconfiguration. We envision that the strategy demonstrated here will boost the advancement of reconfigurable chiral materials with increased complexity for active light control applications through rational molecular design and predictable self-assembly procedures.

Nanoparticles have been widely tested as drug delivery carriers or imaging agents, largely due to their ability to selectively accumulate in tumors through the enhanced permeability and retention (EPR) effect. However, studies show that many tumors afford less efficient EPR effect and that many nanoparticles are trapped in the peri-vascular region after extravasation and barely migrate into tumor centers. This is to a large degree attributed to the dense tumor extracellular matrix (ECM), which functions as a physical barrier to prevent efficient nanoparticle extravasation and diffusion. In this study, we report a photodynamic therapy (PDT) approach to enhance tumor uptake of nanoparticles. Briefly, we encapsulate ZnF(16)Pc, a photosensitizer, into ferritin nanocages, and then conjugate to the surface of the ferritin a single chain viable fragment (scFv) sequence specific to fibroblast activation protein (FAP). FAP is a plasma surface protein widely upregulated in cancer-associated fibroblast (CAF), which is a major source of the ECM fiber components. We found that the scFv conjugated and ZnF(16)Pc loaded ferritin nanoparticles (scFv-Z@FRT) can mediate efficient and selective PDT, leading to eradication of CAFs in tumors. When tested in bilateral 4T1 tumor models, we found that the tumor accumulation of serum albumin (BSA), 10 nm quantum dots (QDs), and 50 nm QDs, was increased by 2, 3.5, and 18 folds, after scFv-Z@FRT mediated PDT. Our studies suggest a novel and safe method to enhance the delivery of nanoparticles to tumors.

BACKGROUND Diabetes is one of the most commonly reported comorbidities among patients infected with SARS-CoV-2. This retrospective study of patients with SARS-CoV-2 infection was conducted to evaluate the association between blood glucose levels and the severity of COVID-19 pneumonia and patient mortality. MATERIAL AND METHODS A total of 268 patients with confirmed SARS-CoV-2 infection were included in this retrospective study. We obtained demographic characteristics, clinical symptoms, laboratory data, and survival information from patients' electronic medical records. Blood glucose was measured on admission to the hospital. Comorbidities, including hypertension, diabetes, chronic kidney disease, chronic liver disease, chronic obstructive pulmonary disease, and cardiovascular disease, were collected by self-reported medical history. RESULTS Significantly higher risks of severe COVID-19 were found in patients with blood glucose levels ranging from 5.53 to 7.27 mmol/L (odds ratio [OR], 3.98; 95% confidence interval [CI], 1.81-8.75) and in patients with blood glucose ≥7.27 mmol/L (OR, 12.10; 95% CI, 5.53-26.48) than in those with blood glucose

The generation of energetic electrons is an effect occurring in any plasmonic nanostructure. However, the number of electrons with high energies generated optically in a plasmonic nanostructure can be relatively small. This is an intrinsic property of the collective plasmon excitations in a Fermi gas of electrons. But the choices of material and geometry have a great impact on the generation rate, and are therefore crucial for designing a nanostructure with a large rate of generation of energetic (hot) electrons. Here we test different plasmonic materials from the point of view of the generation of hot electrons (HEs). Our choice of materials includes both strongly-plasmonic materials (Au, Ag, Cu and Al) and crystals with strongly broadened plasmonic resonances (Pt, TiN and ZrN). Regarding the choice of geometry, we consider two types of nanostructures, single nanocrystals deposited over a dielectric substrate and metastructure absorbers, observing interesting opto-electronic properties. For single nanocrystals, the rate of HE generation is strongly material-dependent since the HE generation rate strongly depends on several physical parameters such as plasmonic enhancement, plasmonic resonance wavelength, Fermi energy, etc. Interestingly, the plasmonic meta-absorbers exhibit a different behaviour. The strongly-plasmonic metals, such as Au, Ag, Cu or Al, show very similar performances, while the materials with damped plasmon resonances demonstrate diverse and reduced rates of HE generation. The physical reason for these different behaviours lies in the dielectric functions of these materials. In the metastructures, plasmonic resonances are in the infrared region and the strongly-plasmonic materials behave as an almost ideal metal, whereas the second group of materials exhibits strong dissipation. This makes the responses from the metastructures made of crystals with damped plasmons strongly dependent on the choice of material. The physical principles described in our study can be useful for designing metastructures and nanodevices based on HEs, which can be used in photo-chemistry and opto-electronics.

The development of theranostic nanomaterials with limited side effects and increased therapeutic efficacy is a promising approach for cancer imaging and therapy. In the present study, the development of a multifunctional metal–organic hybrid nanoparticle (NP) with enhanced photoacoustic (PA) imaging performance able to be actively uptaken by cancer cells for synergistic chemo-photothermal cancer therapy was reported. The theranostic NP was composed through the coordination effect between an ultrasmall gold nanorod (AuNR), a thick coating layer of the organic near-infrared dye IR780, and the anticancer drug doxorubicin (DOX), named AuNR@IR780/DOX-RGD-PEG. In addition, the theranostic NP surface was conjugated with targeting ligand RGD and a protective PEG shell, where the PEG played a role in concealing or exposing the RGD for specific targeting of the NPs to the cancer cells. The theranostic NP demonstrated a greatly enhanced PA imaging signal compared to AuNR or IR780, due to the fact that the electromagnetic field of the AuNR increased the light absorption efficiency of the IR780 coating based on the theoretical simulation results. Furthermore, the “Trojan-horse” active targeting strategy not only increased the uptake of NPs by tumor cells, but also decreased the non-specific uptake by healthy cells, thus limiting the side effects. This study developed a smart theranostic NP for enhanced cancer PA imaging and specific cancer therapy.

The use of biomaterials, with techniques such as DNA-directed assembly or biodirected synthesis, can surpass top-down fabrication techniques in creating plasmonic superstructures in terms of spatial resolution, range of functionality, and fabrication speed. In particular, by enabling a very precise placement of nanoparticles in a bioassembled complex or through the controlled biodirected shaping of single nanoparticles, plasmonic nanocrystals can show remarkably strong circular dichroism (CD) signals. We show that chiral bioplasmonic assemblies and single nanocrystals can enable polarization-sensitive photochemistry based on the generation of energetic (hot) electrons. It is now established that hot plasmonic electrons can induce surface photochemistry or even reshape plasmonic nanocrystals. We show that merging chiral plasmonic nanocrystal systems and the hot-election generation effect offers unique possibilities in photochemistry, such as polarization-sensitive photochemistry promoting nonchiral molecular reactions, chiral photoinduced growth of a colloid at the atomic level, and chiral photochemical destruction of chiral nanocrystals. In contrast, for chiral molecular systems, the equivalent of the described effects is challenging to observe because molecular species typically exhibit very small CD signals. Moreover, we compare our findings with traditional chiral photochemistry at the molecular level, identifying new, different regimes for chiral photochemistry with possibilities that are unique for plasmonic colloidal systems. In this study, we bring together the concept of hot-electron generation and the field of chiral colloidal plasmonics. Using chiral plasmonic nanorod complexes as a model system, we demonstrate remarkably strong CD in both optical extinction and generation rates of hot electrons. Studying the regime of steady-state excitation, we discuss the influence of geometrical and material parameters on the chiral effects involved in the generation of hot electrons. Optical chirality and the chiral hot-electron response in the nanorod dimers result from complex interparticle interactions, which can appear in the weak coupling regime or in the form of Rabi splitting. Regarding practical applications, our study suggests interesting opportunities in polarization-sensitive photochemistry, in chiral recognition or separation, and in promoting chiral crystal growth at the nanoscale.

Hot electron photodetection (HEPD) excited by surface plasmon can circumvent bandgap limitations, opening pathways for additional energy harvesting. However, the costly and time-consuming lithography has long been a barrier for large-area and mass production of HEPD. In this paper, we proposed a planar and electron beam lithography-free hot electron photodetector based on the Fabry-Perot (F-P) resonance composed of Au/MoS2/Au cavity. The hot electron photodetector has a nanoscale thickness, high spectral tunability, and multicolour photoresponse in the near-infrared region due to the increased round-trip phase shift by using high refractive index MoS2. We predict that the photoresponsivity can achieve up to 23.6 mA W-1 when double cavities are integrated with the F-P cavity. The proposed hot electron photodetector that has a nanoscale thickness and planar stacking is a perfect candidate for large-area and mass production of HEPD.

An ultrathin near-perfect MoSe2 absorber working in the visible regime is demonstrated theoretically and experimentally, and it consists of a MoSe2/Au bi-layer film. The polymer-assisted deposition method is used to synthesize MoSe2 films, which can reduce the roughness and thus improve the film absorption. Simulation results show that the absorption of the absorber with 22 nm MoSe2 reaches to larger than 90% between 628.5 nm and 718 nm with a peak value up to 99.5% at 686 nm. Moreover, the measured absorption also shows near-perfect absorption of this simple absorber. Finally, an ultrathin photodetector is fabricated based on this perfect absorber and shows on/off reproducibility and remarkable photocurrent, which is three orders of magnitude higher than the dark current.

In this paper, an isolated MHz resonant dc-dc converter with regulating capability is proposed. This proposed dc-dc converter works at fixed switching frequency and can be regulated by an auxiliary non-isolated PWM dc-dc converter. In the proposed converter, only a portion of power is transferred through two-stage, namely the DC transformer (DCX) stage and the auxiliary PWM dc-dc stage; and most of the input power is delivered to load directly through the DCX stage, which makes the total efficiency of the dc-dc converter higher than that of conventional two-stage converter. Finally, two 4SV/I2V-25A prototypes are built to verify the theoretical analysis. The peak efficiency of them at 55V input voltage are 96.7% and 97.4%, respectively. The power density of them reaches 370W/in3.

Input-parallel output-parallel (IPOP)-connected converter systems allow the use of low-power converter modules for high-power applications. An IPOP converter topology with half-wave, daisy chain-connected rectifiers is presented which consists of multiple half-bridge (HB) dc–dc converter modules. By utilizing a common-duty-ratio control scheme, without a dedicated current-sharing controller, automatic sharing of input current and load current in the IPOP converter is achieved even in the presence of differences of more than 10% in various module parameters. The steady-state and dynamic-state current-sharing performance of the proposed IPOP converter is analyzed by using a steady-state dc model and a small-signal model of the system, respectively. It is concluded that steady-state current sharing among modules can be realized by applying a common-duty-ratio control scheme and by reducing the difference in transformer turn ratios, while dynamic-state current sharing is only slightly affected by substantial module parameter mismatches. The stability and current-sharing performance are verified by Saber simulation and an 800-W prototype consisting of two HB modules. The IPOP converter topology under the common-duty-ratio scheme can be extended to any system of three or more converter modules, including full-bridge dc–dc converters.

The delivery of therapeutic cancer agents via nanomaterials has attracted great attention recently. Although encouraging, tumor treatment response remains unsatisfactory. To address this concern, we constructed a new micellar nanocomplex by conjugating hyaluronic acid (HA) with iron oxide nanoparticle (IONP). When an external magnetic field is applied to the tumor area, HA-IONP will specifically accumulate in the tumor due to the strong IONP magnetism. In addition, HA can bind to CD44 that is overexpressed on tumor cells. With combined magnetic, CD44, and EPR targeting, the efficient delivery of HA-IONP into the tumor is expected to enhance cancer treatment efficiency. After encapsulation of the chemotherapy drug, homocamptothecin (HCPT), the theranostic potency of HA-IONP/HCPT (HIH), was investigated. The improved tumor homing behavior of HIH was observed by magnetic resonance imaging (MRI) when an external magnetic field is utilized. Moreover, HIH showed remarkable tumor ablation efficiency with magnetic targeting after 3 mg/kg intravenous administration (equivalent dose of free HCPT), and the tumors almost disappeared after treatment. No obvious systemic toxicity was detected. This excellent biocompatibility and tumor targetability suggests that HIH is a promising theranostic nanocomplex with great translational potency. The application of HA-IONP platform can also be extended to delivery of the other hydrophobic chemotherapy drugs or phototherapy agents.

The realization of ultrabroadband absorption is a fundamental part of a thermal emitter, especially in the application of radiative cooling. This study involved proposing and systematically analyzing a novel structure termed as an embedded metal-dielectric-metal (EMDM) structure. The results in the case of an individual resonator indicated that the EMDM resonator displayed a broader full width at half maximum (FWHM) that was 1.9 times that of the metal-dielectric-metal (MDM) resonator due to mode matching at the terminated end and enhanced scattering intensity. With respect to the case of periodic resonators, single-sized periodic EMDM resonators are employed to achieve a broader FWHM that is 3.8 times that of the MDM resonators. In addition, a strong coupling effect is confirmed between localized MDM and hybrid modes. An application of lossy-dielectric based periodic three-dimensional EMDM resonators indicated that an average absorptivity of 0.85 in the entire atmospheric window (8–13 μm). The results revealed the potential of EMDM structures for radiative cooling devices and other ultrabroadband absorbers.