Designable Nanoadaptor for Enhanced Recognition of Natural Killer Cell to Tumor via Bio-orthogonal Click Reaction.

Highly efficient recognition of cancer cells by immune cells is important for successful therapeutic-cell-based cancer immunotherapy. Herein, we present a facile NIR-II nanoadaptor [hyaluronic acid (HA)/dibenzocyclooctyne (DBCO)-Au:Ag2Te quantum dots (QDs)] for enhancing the tumor recognition and binding ability of natural killer (NK) cells via a bio-orthogonal click reaction in vivo. The Nanoadaptor possesses superior tumor-targeting capacity, facilitating the accumulation of the chemical receptor DBCO at the tumor sites. Subsequently, the enrichment of DBCO on tumor cell surfaces provides multivalent recognition sites for capturing pretreated azide engineered NK92 cells (NK92-N3) through an efficient click reaction, thereby significantly enhancing the therapeutical efficiency. The dynamic process of nanoadaptor-mediated recognition of NK cells to tumor cells could be vividly observed using multiplexed NIR-II fluorescence imaging in a mouse model of lung cancer. Such a nanoadaptor strategy can be extended to other therapeutic cellular systems and holds promise for future clinical applications.

Programmed Remodeling of the Tumor Milieu to Enhance NK Cell Immunotherapy Combined with Chemotherapy for Pancreatic Cancer.

Natural killer (NK) cell-based adoptive immunotherapy has demonstrated encouraging therapeutic effects in clinical trials for hematological cancers. However, the effectiveness of treatment for solid tumors remains a challenge due to insufficient recruitment and infiltration of NK cells into tumor tissues. Herein, a programmed nanoremodeler (DAS@P/H/pp) is designed to remodel dense physical stromal barriers and for dysregulation of the chemokine of the tumor environment to enhance the recruitment and infiltration of NK cells in tumors. The DAS@P/H/pp is triggered by the acidic tumor environment, resulting in charge reversal and subsequent hyaluronidase (HAase) release. HAase effectively degrades the extracellular matrix, promoting the delivery of immunoregulatory molecules and chemotherapy drugs into deep tumor tissues. In mouse models of pancreatic cancer, this nanomediated strategy for the programmed remodeling of the tumor microenvironment significantly boosts the recruitment of NK92 cells and their tumor cell-killing capabilities under the supervision of multiplexed near-infrared-II fluorescence.

Theoretical Study of the Ternary Compound Monolayer CuP2Se for Photocatalytic Water Splitting with Efficient Optical Absorption.

Utilizing photocatalytic method to produce hydrogen by splitting water is an efficient strategy to solve the hotspot issues of energy crisis and environmental pollution. Herein, we systematically investigate the corresponding properties of the reported Cu-bearing ternary compound monolayer CuP2Se by using the first-principle calculations. The monolayer CuP2Se has quite small cleavage energy of 0.51 J/m2, indicating it can be easily produced by the mechanical exfoliation method experimentally. In addition, it is an indirect bandgap semiconductor material which has a moderate value of 1.91 eV. The conduction band minimum (CBM) and valence band maximum (VBM) can perfectly straddle the redox potentials of water when a biaxial strain of -4% to 4% is applied, unveiling the high photocatalytic thermodynamic stability of monolayer CuP2Se in response to the effect of solvent tension. Remarkably, the monolayer CuP2Se also demonstrates significant sunlight capturing ability in the visible region. The outstanding electronic and optical properties suggest that the monolayer CuP2Se is undoubtedly a viable material for photocatalytic water splitting.

High Curie temperature ferromagnetic monolayer T-CrSH and valley physics of T-CrSH/WS2 heterostructure.

Two-dimensional magnetic materials are attracting widespread attention not only for their excellent applications in spintronic devices but also for their potential to regulate valley splitting, which is crucial for valleytronics. Herein, we design a monolayer Janus ferromagnetic semiconductor T-CrSH by using first-principles calculations. We reveal that monolayer T-CrSH has a magnetic moment of 3µB per unit cell, which is primarily contributed by the 3d orbitals of the Cr atom. Monte Carlo simulations suggest that the Curie temperature of T-CrSH is 193 K, and it can rise to 402 K when a 5% tensile strain is applied. Furthermore, the valley degeneracy of WS2 can be lifted when monolayer T-CrSH is used as a substrate. The obtained valley splitting in the conduction band is 13.7 meV and that in the valence band is 157.5 meV. In addition, the large valley polarization of 12.8 meV in the conduction band makes it easy to achieve an electron-doped valley Hall current and spin Hall current when performing in an in-plane electric field.

Ultra-Wideband Ranging Error Mitigation with Novel Channel Impulse Response Feature Parameters and Two-Step Non-Line-of-Sight Identification.

The effective identification and mitigation of non-line-of-sight (NLOS) ranging errors are essential for achieving high-precision positioning and navigation with ultra-wideband (UWB) technology in harsh indoor environments. In this paper, an efficient UWB ranging-error mitigation strategy that uses novel channel impulse response parameters based on the results of a two-step NLOS identification, composed of a decision tree and feedforward neural network, is proposed to realize indoor locations. NLOS ranging errors are classified into three types, and corresponding mitigation strategies and recall mechanisms are developed, which are also extended to partial line-of-sight (LOS) errors. Extensive experiments involving three obstacles (humans, walls, and glass) and two sites show an average NLOS identification accuracy of 95.05%, with LOS/NLOS recall rates of 95.72%/94.15%. The mitigated LOS errors are reduced by 50.4%, while the average improvement in the accuracy of the three types of NLOS ranging errors is 61.8%, reaching up to 76.84%. Overall, this method achieves a reduction in LOS and NLOS ranging errors of 25.19% and 69.85%, respectively, resulting in a 54.46% enhancement in positioning accuracy. This performance surpasses that of state-of-the-art techniques, such as the convolutional neural network (CNN), long short-term memory-extended Kalman filter (LSTM-EKF), least-squares-support vector machine (LS-SVM), and k-nearest neighbor (K-NN) algorithms.

Tailoring Near-Infrared-IIb Fluorescence of Thulium(III) by Nanocrystal Structure Engineering.

Currently, mainstream lanthanide probes with fluorescence located in the second near-infrared subwindow of 1500-1700 nm (NIR-IIb) are predominantly Er(III)-based nanoparticles (NPs). Here we report a newly developed NIR-IIb fluorescent nanoprobe, α-Tm NP (cubic-phase NaYF4@NaYF4:Tm@NaYF4), with an emission at 1630 nm. We activate the 1630 nm emission of Tm(III) in α-Tm NP through the large spread of the Stark split sublevels induced by the crystal-field effect of the α-NaYF4 host. Further, we systematically investigated the effect of crystalline structure of the host NaYF4 NP (cubic phase (α) or hexagonal phase (ß)), the type and concentrations of dopants (Yb(III), Tm(III), and Ca(II) ions) in the α-phase host, and the thicknesses of the interlayer and inert shell on the NIR-IIb fluorescence of Tm(III). The ultimate nanostructure presents a significant enhancement factor of the NIR-IIb photoluminescence intensity of Tm(III) up to ∼315. With this bright NIR-IIb fluorescent nanoprobe, we demonstrate high-spatial-resolution time-coursing imaging of breast cancer bone metastasis.

Interface-Mediation-Enabled High-Performance Near-Infrared AgAuSe Quantum Dot Light-Emitting Diodes.

Near-infrared (NIR) quantum dot (QD) light-emitting diodes (LEDs) (NIR-QLEDs) for recognition and tracking applications underpin the future of night-vision technology. However, the performance of environmentally benign materials and devices has lagged far behind that of their Pb-containing counterparts. In this study, we demonstrate the superior performance of NIR-QLEDs based on efficient AgAuSe QDs with contact interface mediation. Consequently, we reveal that using cysteamine-treated QD film contact heterointerfaces can effectively eliminate contact defects in devices and preserve their excellent emissive properties. Additionally, the dipole moment orientation of the coordinated additives is inverse of the heterojunction potential difference, simultaneously blocking electrons and enhancing hole injection in operando, optimizing the LED charge injection balance. These devices exhibit a high external quantum efficiency (EQE) and a power conversion efficiency (PCE) of 15.8 and 12.7% at 1046 nm, respectively, a sub-band gap turn-on voltage of 0.9 V, and a low current density (over 10% of the EQE from 0.0017 to 0.31 mA cm-2). These are the highest EQE and PCE values ever reported for environmentally benign NIR-QLEDs. The results of this study can provide a general strategy for the practical application of QDs in electroluminescent devices.

The Effects of Pressure Gradient on Papilledema Improvement After Venous Sinus Stenting in Idiopathic Intracranial Hypertension.

PURPOSE: This study aimed to evaluate the impact of the pressure gradient on papilledema after stenting in patients with idiopathic intracranial hypertension (IIH) patients and venous sinus stenosis (VSS). MATERIALS AND METHODS: In this prospective cohort study, we examined 121 patients with IIH and VSS who underwent stenting. The papilledema Frisen grade at the 1-month follow-up was used as a grouping factor (favorable outcome: 0-1; unfavorable outcome: 2-5). We used multivariable logistic regression modeling to determine independent predictors of favorable outcome. The performance of the prediction model was evaluated using a receiver operating characteristic (ROC) analysis. RESULTS: A total of 96 patients had papilledema grades 0 to 1, and 25 patients had papilledema grades 2 to 5. Patients with the first group had significantly lower gradient pressures preoperatively (15.2 mmHg vs. 21.4 mmHg, p=0.001) and postoperatively (2 mmHg vs. 3.3 mmHg, p=0.002) relative to those in the second group. Multivariate analysis indicated that preoperative pressure gradient (odds ratio [OR] = 1.119; 95% confidence interval [CI] = 1.034-1.211]) and postoperative pressure gradient (OR = 1.498; 95% CI = 1.147-1.957) were independent predictors of favorable outcome. In the ROC analysis, the cut-off pressure gradient for the highest sensitivity (0.44) and specificity (0.874) was 22.75 mmHg, with a Youden's index of 0.314. Survival analysis demonstrated that patients with a preoperative pressure gradient <22.75 mmHg had more rapid improvement of papilledema than did those with a pressure gradient >22.75 mmHg (mean+SD: 2.639+0.382 [95% CI: 1.890-3.388] versus mean+SD: 3.882+0.884 [95% CI: 2.149-5.616]; p=0.004). CONCLUSION: A significant reduction in the pressure gradient appears to be strongly correlated with the success of VSS in patients with IIH. A higher preoperative pressure gradient may reduce stenting efficacy in patients with IIH. CLINICAL IMPACT: Venous sinus stenting has the potential to yield substantial clinical advantages in individuals diagnosed with idiopathic intracranial hypertension with venous sinus stenosis. Nevertheless, a heightened preoperative pressure gradient could lead to less favorable results. Thus, the early adoption of venous sinus stenting is advised to avert additional irreversible clinical deterioration among idiopathic intracranial hypertension patients with venous sinus stenosis.

Photocatalytic water splitting for hydrogen production with high efficiency monolayer In2Te5: a theoretical study.

Employing density functional theory (DFT) calculations, we explore the excellent performance of two-dimensional (2D) semiconductor In2Te5 in photocatalytic water splitting at the theoretical level. The calculated results illustrate that 2D In2Te5 is a direct band gap semiconductor with a moderate band gap value and an ultrahigh optical absorption coefficient in the visible light region. It was found that its conduction band edge is higher than the reduction potential of water (-4.44 eV), which proves that it can split water to produce hydrogen. Furthermore, its excellent hydrogen evolution activity can be tuned under an appropriate biaxial strain. In addition, 2D In2Te5 shows a remarkable photo-generated current, suggesting that electrons and holes can be separated efficiently. Our results offer a superior candidate material for realizing photocatalytic water splitting for hydrogen evolution.

Unveiling the energy transfer mechanism between aqueous colloidal NIR-II quantum dots and water.

Hydrophilic semiconductor quantum dots (QDs) with emission in the second near-infrared window (NIR-II) have been widely studied in bioimaging applications. In such cases, QDs are usually dispersed in water. As is known, water has strong absorbance in the NIR-II region. However, investigations on the interaction between NIR-II emitters and water molecules are ignored in previous studies. Herein, we synthesized a series of mercaptoundecanoic acid-coated silver sulfide (Ag2S/MUA) QDs with various emissions that partially or completely overlapped with the absorbance of water at 1200 nm. By constructing a hydrophobic interface of cetyltrimethylammonium bromide (CTAB) with MUA on the Ag2S QDs surface via forming an ionic bond, significant enhancement of Ag2S QDs photoluminescence (PL) intensity was observed, as well as a prolonged lifetime. These findings suggest that there is an energy transfer between Ag2S QDs and water in addition to the classical resonance absorption. Transient absorption and fluorescence spectra results revealed that the increased PL intensities and lifetime of Ag2S QDs originated from the suppressed energy transfer from Ag2S QDs to the water due to the CTAB bridged hydrophobic interfaces. This discovery is important for a deeper understanding of the photophysical mechanisms of QDs and their applications.

High Quantum Efficiency Rare-Earth-Doped Gd2O2S:Tb, F Scintillators for Cold Neutron Imaging.

High-resolution neutron radiography provides novel and stirring opportunities to investigate the structures of light elements encased by heavy elements. For this study, a series of Gd2O2S:Tb, F particles were prepared using a high-temperature solid phase method and then used as a scintillation screen. Upon reaching 293 nm excitation, a bright green emission originated from the Tb3+ luminescence center. The level of F doping affected the fluorescence intensity. When the F doping level was 8 mol%, the fluorescence intensity was at its highest. The absolute quantum yield of the synthesized particles reached as high as 77.21%. Gd2O2S:Tb, F particles were applied to the scintillation screen, showing a resolution on the neutron radiograph as high as 12 µm. These results suggest that the highly efficient Gd2O2S:Tb, F particles are promising scintillators for the purposes of cold neutron radiography.

Activatable Rare Earth Near-Infrared-II Fluorescence Ratiometric Nanoprobes.

Rational design of efficient lanthanide-doped down-shifting nanoparticles (DSNPs) has attracted tremendous attention. However, energy loss was inevitable in the multiple Ln3+ doping systems owing to complex energy migration processes. Here, an efficient NaErF4@NaYF4@NaYF4:10%Nd@NaYF4 DSNP was tactfully designed, in which a buffer layer of NaYF4 was modulated to restrict the interionic energy migration between Er3+ and Nd3+; meanwhile, the surface defects were passivated by an outermost layer of NaYF4. Therefore, the as-prepared DSNPs exhibited two intensive near-infrared-II fluorescence emissions of 1525 nm from Er3+ and 1060 nm from doped Nd3+ under 808 nm excitation. Further, a novel ratiometric nanoprobe NaErF4@NaYF4@NaYF4:10%Nd@NaYF4@A1094 was fabricated by coupling an organic dye of A1094 onto the DSNP surface to quench the 1060 nm emission by the efficient Förster resonance energy transfer, while emission at 1525 nm retained. Thereafter, these activatable ratiometric nanoprobes were used for rapid and sensitive detection of peroxynitrite (ONOO-) in vivo.

Colloidal Alloyed Quantum Dots with Enhanced Photoluminescence Quantum Yield in the NIR-II Window.

Semiconductor quantum dots (QDs) with photoluminescence (PL) emission at 900-1700 nm (denoted as the second near-infrared window, NIR-II) exhibit much-depressed photon absorption and scattering, which has stimulated extensive researches in biomedical imaging and NIR devices. However, it is very challenging to develop NIR-II QDs with a high photoluminescence quantum yield (PLQY) and excellent biocompatibility. Herein, we designed and synthesized an alloyed silver gold selenide (AgAuSe) QD with a bright emission from 820 to 1170 nm and achieved a record absolute PLQY of 65.3% at 978 nm emission among NIR-II QDs without a toxic element and a long lifetime of 4.58 µs. It is proved that the high PLQY and long lifetime are mainly attributed to the prevented nonradiative transition of excitons, probably resulted from suppressing cation vacancies and crystal defects from the high mobility of Ag ions by alloying Au atoms. These high-PLQY QDs with nontoxic heavy metal exhibit great application potential in bioimaging, light emitting diodes (LEDs), and photovoltaic devices.

Pb-Doped Ag2 Se Quantum Dots with Enhanced Photoluminescence in the NIR-II Window.

Ag2 Se quantum dots (QDs) as an effective biological probe in the second near-infrared window (NIR-II, 1000-1700 nm) have been widely applied in bioimaging with high tissue penetration depth and high spatiotemporal resolution. However, the ions deficiency and crystal defects caused by the high Ag+ mobility in Ag2 Se crystals are mainly responsible for the inefficient photoluminescence (PL) of Ag2 Se QDs. Herein, a tailored route is reported to achieve controllable doping of Ag2 Se QDs in which Ag is exchanged by Pb via cation exchange (CE), which is unattainable by direct synthetic methods. The Pb-doped Ag2 Se QDs (denoted as Pb:Ag2 Se QDs) present fire-new optical features with significantly enhanced PL intensity of 4.2 folds. Photoelectron spectroscopy confirms that Pb acts as an n-type dopant for Ag2 Se QDs and therefore the electronic impurities provide additional carriers to fill the traps. Moreover, the general validity of this method is demonstrated to convert different sized Ag2 Se into Pb:Ag2 Se QDs, so that a wide range of NIR-II PL with high intensity is obtained. The bright NIR-II emission of Pb:Ag2 Se QDs is further successfully performed in lymphatic system mapping.

Controlled Synthesis of Ag2 Te@Ag2 S Core-Shell Quantum Dots with Enhanced and Tunable Fluorescence in the Second Near-Infrared Window.

Fluorescence in the second near-infrared window (NIR-II, 900-1700 nm) has drawn great interest for bioimaging, owing to its high tissue penetration depth and high spatiotemporal resolution. NIR-II fluorophores with high photoluminescence quantum yield (PLQY) and stability along with high biocompatibility are urgently pursued. In this work, a Ag-rich Ag2 Te quantum dots (QDs) surface with sulfur source is successfully engineered to prepare a larger bandgap of Ag2 S shell to passivate the Ag2 Te core via a facile colloidal route, which greatly enhances the PLQY of Ag2 Te QDs and significantly improves the stability of Ag2 Te QDs. This strategy works well with different sized core Ag2 Te QDs so that the NIR-II PL can be tuned in a wide range. In vivo imaging using the as-prepared Ag2 Te@Ag2 S QDs presents much higher spatial resolution images of organs and vascular structures as compared with the same dose of Ag2 Te nanoprobes administrated, suggesting the success of the core-shell synthetic strategy and the potential biomedical applications of core-shell NIR-II nanoprobes.

Interfacially Bridging Covalent Network Yields Hyperstable and Ultralong Virus-Based Fibers for Engineering Functional Materials.

We present a strategy of interfacially bridging covalent network within tobacco mosaic virus (TMV) virus-like particles (VLPs). We arranged T103C cysteine to laterally conjugate adjacent subunits. In the axis direction, we set A74C mutation and systematically investigated candidate from E50C to P54C as the other thiol function site, for forming longitudinal disulfide bond chains. Significantly, the T103C-TMV-E50C-A74C shows the highest robustness in assembly capability and structural stability with the largest length, for TMV VLP to date. The fibers with lengths from several to a dozen of micrometers even survive under pH 13. The robust nature of this TMV VLP allows for reducer-free synthesis of excellent electrocatalysts for application in harshly alkaline hydrogen evolution.

Tumor Microenvironment-Activated NIR-II Nanotheranostic System for Precise Diagnosis and Treatment of Peritoneal Metastasis.

Activatable theranostic systems show potential for improved tumor diagnosis and therapy owing to high detection specificities, effective ablation, and minimal side-effects. Herein, a tumor microenvironment (TME)-activated NIR-II nanotheranostic system (FEAD1) for precise diagnosis and treatment of peritoneal metastases is presented. FEAD1 was fabricated by self-assembling the peptide Fmoc-His, mercaptopropionic-functionalized Ag2 S quantum dots (MPA-Ag2 S QDs), the chemodrug doxorubicin (DOX), and NIR absorber A1094 into nanoparticles. We show that in healthy tissue, FEAD1 exists in an NIR-II fluorescence "off" state, because of Ag2 S QDs-A1094 interactions, while DOX remains in stealth mode. Upon delivery of FEAD1 to the tumor, the acidic TME triggers its disassembly through breakage of the Fmoc-His metal coordination and DOX hydrophobic interactions. Release of A1094 switches on Ag2 S fluorescence, illuminating the tumor, accompanied by burst release of DOX within the tumor tissue, thereby achieving precise tumor theranostics. This TME-activated theranostic strategy holds great promise for future clinical applications.

NiFe Alloy Nanoparticles with hcp Crystal Structure Stimulate Superior Oxygen Evolution Reaction Electrocatalytic Activity.

Tuning the crystal phase of metal alloy nanomaterials has been proved a significant way to alter their catalytic properties based on crystal structure and electronic property. Herein, we successfully developed a simple strategy to controllably synthesize a rare crystal structure of hexagonal close-packed (hcp) NiFe nanoparticle (NP) encapsulated in a N-doped carbon (NC) shell (hcp-NiFe@NC). Then, we systemically investigated the oxygen evolution reaction (OER) performance of the samples under alkaline conditions, in which the hcp-NiFe@NC exhibits superior OER activity compared to the conventional face-centered cubic (fcc) NiFe encapsulated in a N-doped carbon shell (fcc-NiFe@NC). At the current densities of 10 and 100 mA cm-2 , the hcp-NiFe@NC with Fe/Ni ratio of ≈5.4 % only needs ultralow overpotentials of 226 mV and 263 mV versus reversible hydrogen electrode in 1.0 m KOH electrolyte, respectively, which were extremely lower than those of fcc-NiFe@NC and most of other reported NiFe-based electrocatalysts. We proposed that hcp-NiFe possesses favorable electronic property to expedite the reaction on the NC surface, resulting higher catalytic activity for OER. This research provides a new insight to design more efficient electrocatalysts by considering the crystal phase correlated electronic property.

Chemical Valence-Dependent Electrocatalytic Activity for Oxygen Evolution Reaction: A Case of Nickel Sulfides Hybridized with N and S Co-Doped Carbon Nanoparticles.

Exploration of the relationship between electrocatalytic activities and their chemical valence is very important in rational design of high-efficient electrocatalysts. A series of porous nickel sulfides hybridized with N and S co-doped carbon nanoparticles (Nix Sy -NSCs) with different chemical valences of Ni, Ni9 S8 -NSCs, Ni9 S8 -NiS1.03 -NSCs, and NiS1.03 -NSCs are successfully fabricated, and their electrocatalytic performances as oxygen evolution reaction electrocatalysts are systematically investigated. The Nix Sy -NSCs are obtained via a two-step reaction including a low-temperature synthesis of Ni-Cys precursor followed by thermal decomposing of the precursor in Ar atmosphere. By controlling the sulfidation process during the formation of Nix Sy -NSCs, Ni9 S8 -NSCs, Ni9 S8 -NiS1.03 -NSCs, and NiS1.03 -NSCs are obtained, respectively, giving rise to the increase of high-valence Ni component, and resulting in gradually enhanced oxygen evolution reaction electrocatalytic activities. In particular, the NiS1.03 -NSCs show an exceptional low overpotential of ≈270 mV versus reversible hydrogen electrode at a current density of 10 mA cm-2 and a small Tafel slope of 68.9 mV dec-1 with mass loading of 0.25 mg cm-2 in 1 m KOH and their catalytic activities remained for at least 10 h, which surpass the state-of-the-art IrO2 , RuO2 , and Ni-based electrocatalysts.

Revealing the Role of Electrocatalyst Crystal Structure on Oxygen Evolution Reaction with Nickel as an Example.

Establishing a correlation between the crystal structure and electrocatalytic activity is crucial to the rational design of high performance electrocatalysts. In this work, taking the widely investigated nickel (Ni) based nonprecious oxygen evolution reaction (OER) catalyst as an example, for the first time, it is reported that the crystal structure plays a critical role in determining the OER performance. Similar-sized nickel nanoparticles but in different hexagonal close-packed phase and face-centered cubic phase coated with N-doped carbon shells, noted as hcp-Ni@NC and fcc-Ni@NC, are successfully prepared, respectively, in which the N-coated carbon shell structures were also similar. Surprisingly, a dramatically enhanced OER performance of hcp-Ni@NC in comparison with fcc-Ni@NC is observed. The hcp-Ni@NC only requires 305 mV overpotential to achieve the current density of 10 mA cm-2 , which is 55 mV lower than that of fcc-Ni@NC, which can be ascribed to the influence of nickel crystal phase on the electron structure of N-doped carbon shell. This finding will bring new thinking toward the rational design of high performance non-noble metal electrocatalysts.