Distinguishing the Charge Trapping Centers in CaF2-Based 2D Material MOSFETs.

Crystalline calcium fluoride (CaF2) is drawing significant attention due to its great potential of being the gate dielectric of two-dimensional (2D) material MOSFETs. It is deemed to be superior to boron nitride and traditional silicon dioxide (SiO2) because of its larger dielectric constant, wider band gap, and lower defect density. Nevertheless, the CaF2-based MOSFETs fabricated in the experiment still present notable reliability issues, and the underlying reason remains unclear. Here, we studied the various intrinsic defects and adsorbates in CaF2/molybdenum disulfide (MoS2) and CaF2/molybdenum disilicon tetranitride (MoSi2N4) interface systems to reveal the most active charge-trapping centers in CaF2-based 2D material MOSFETs. An elaborate Table comparing the importance of different defects in both n-type and p-type devices is provided. Most impressively, the oxygen molecules (O2) adsorbed at the interface or surface, which are inevitable in experiments, are as active as the intrinsic defects in channel materials, and they can even change the MoSi2N4 to p-type spontaneously. These results mean that it is necessary to develop a high-vacuum packaging process, as well as prepare high-quality 2D materials for better device performance.

Spectrum-Dependent Image Convolutional Processing via a Two-Dimensional Polarization-Sensitive Photodetector.

Currently, the improvement in the processing capacity of traditional processors considerably lags behind the demands of real-time image processing caused by the advancement of photodetectors and the widespread deployment of high-definition image sensors. Therefore, achieving real-time image processing at the sensor level has become a prominent research domain in the field of photodetector technology. This goal underscores the need for photodetectors with enhanced multifunctional integration capabilities than can perform real-time computations using optical or electrical signals. In this study, we employ an innovative p-type semiconductor GaTe0.5Se0.5 to construct a polarization-sensitive wide-spectral photodetector. Leveraging the wide-spectral photoresponse, we realize three-band imaging within a wavelength range of 390-810 nm. Furthermore, real-time image convolutional processing is enabled by configuring appropriate convolution kernels based on the polarization-sensitive photocurrents. The innovative design of the polarization-sensitive wide-spectral GaTe0.5Se0.5-based photodetector represents a notable contribution to the domain of real-time image perception and processing.

Spectrometer-Less Remote Sensing Image Classification Based on Gate-Tunable van der Waals Heterostructures.

Remote sensing technology, which conventionally employs spectrometers to capture hyperspectral images, allowing for the classification and unmixing based on the reflectance spectrum, has been extensively applied in diverse fields, including environmental monitoring, land resource management, and agriculture. However, miniaturization of remote sensing systems remains a challenge due to the complicated and dispersive optical components of spectrometers. Here, m-phase GaTe0.5Se0.5 with wide-spectral photoresponses (250-1064 nm) and stack it with WSe2 are utilizes to construct a two-dimensional van der Waals heterojunction (2D-vdWH), enabling the design of a gate-tunable wide-spectral photodetector. By utilizing the multi-photoresponses under varying gate voltages, high accuracy recognition can be achieved aided by deep learning algorithms without the original hyperspectral reflectance data. The proof-of-concept device, featuring dozens of tunable gate voltages, achieves an average classification accuracy of 87.00% on 6 prevalent hyperspectral datasets, which is competitive with the accuracy of 250-1000 nm hyperspectral data (88.72%) and far superior to the accuracy of non-tunable photoresponse (71.17%). Artificially designed gate-tunable wide-spectral 2D-vdWHs GaTe0.5Se0.5/WSe2-based photodetector present a promising pathway for the development of miniaturized and cost-effective remote sensing classification technology.

Macrocycles and Acyclic Cucurbit[n]urils as Pseudo[2]catenane Partners for Long-Acting Neuromuscular Blocks and Rapid Reversal In Vivo.

Long-acting neuromuscular blocks followed by rapid reversal may provide prolonged surgeries with improved conditions by omitting repetitive or continuous administration of the neuromuscular blocking agent (NMBA), eliminating residual neuromuscular block and minimizing postoperative recovery, which, however, is not clinically available. Here, we demonstrate that imidazolium-based macrocycles (IMCs) and acyclic cucurbit[n]urils (ACBs) can form such partners by functioning as long-acting NMBAs and rapid reversal agents through a pseudo[2]catenation mechanism based on stable complexation with Ka values of over 109 M-1. In vivo experiments with rats reveal that, at the dose of 2- and 3-fold ED90, one IMC attains a duration of action corresponding to 158 or 442 min for human adults, covering most of prolonged surgeries. The block can be reversed by one ACB with recovery time significantly shorter than that achieved by sugammadex for reversing the block of rocuronium, the clinically most widely used intermediate-acting NMBA.

Polarization Reversal of Group IV-VI Semiconductors with Pucker-Like Structure: Mechanism Dissecting and Function Demonstration.

Polarization imaging presents advantages in capturing spatial, spectral, and polarization information across various spectral bands. It can improve the perceptual ability of image sensors and has garnered more applications. Despite its potential, challenges persist in identifying band information and implementing image enhancement using polarization imaging. These challenges often necessitate integrating spectrometers or other components, resulting in increased complexities within image processing systems and hindering device miniaturization trends. Here, the characteristics of anisotropic absorption reversal are systematically elucidated in pucker-like group IV-VI semiconductors MX (M = Ge, Sn; X = S, Se) through theoretical predictions and experimental validations. Additionally, the fundamental mechanisms behind anisotropy reversal in different bands are also explored. The photodetector is constructed by utilizing MX as a light-absorbing layer, harnessing polarization-sensitive photoresponse for virtual imaging. The results indicate that the utilization of polarization reversal photodetectors holds advantages in achieving further multifunctional integration within the device structure while simplifying its configuration, including band information identification and image enhancement. This study provides a comprehensive analysis of polarization reversal mechanisms and presents a promising and reliable approach for achieving dual-band image band identification and image enhancement without additional auxiliary components.

Low symmetric sub-wavelength array enhanced lensless polarization-sensitivity photodetector of germanium selenium.

Polarization-sensitive photodetectors, with the ability of identifying the texture-, stress-, and roughness-induced light polarization state variation, displace unique advantages in the fields of national security, medical diagnosis, and aerospace. The utilization of in-plane anisotropic two-dimensional (2D) materials has led the polarization photodetector into a polarizer-free regime, and facilitated the miniaturization of optoelectronic device integration. However, the insufficient polarization ratio (usually less than 10) restricts the detection resolution of polarized signals. Here, we designed a sub-wavelength array (SWA) structure of 2D germanium selenium (GeSe) to further improve its anisotropic sensitivity, which boosts the polarized photocurrent ratio from 1.6 to 18. This enhancement comes from the combination of nano-scale arrays with atomic-scale lattice arrangement at the low-symmetric direction, while the polarization-sensitive photoresponse along the high-symmetric direction is strongly suppressed due to the SWA-caused depolarization effect. Our mechanism study revealed that the SWA can improve the asymmetry of charge distribution, attenuate the matrix element in zigzag direction, and the localized surface plasma, which elevates the photo absorption and photoelectric transition probability along the armchair direction, therefore accounts for the enhanced polarization sensitivity. In addition, the photodetector based on GeSe SWA exhibited a broad power range of 40 dB at a near-infrared wavelength of 808 nm and the ability of weak-light detection under 0.1 LUX of white light (two orders of magnitude smaller than pristine 2D GeSe). This work provides a feasible guideline to improve the polarization sensitivity of 2D materials, and will greatly benefit the development of polarized imaging sensors.

A Gate Programmable van der Waals Metal-Ferroelectric-Semiconductor Vertical Heterojunction Memory.

Ferroelectricity, one of the keys to realize non-volatile memories owing to the remanent electric polarization, is an emerging phenomenon in the 2D limit. Yet the demonstrations of van der Waals (vdW) memories using 2D ferroelectric materials as an ingredient are very limited. Especially, gate-tunable ferroelectric vdW memristive device, which holds promises in future multi-bit data storage applications, remains challenging. Here, a gate-programmable multi-state memory is shown by vertically assembling graphite, CuInP2 S6 , and MoS2 layers into a metal(M)-ferroelectric(FE)-semiconductor(S) architecture. The resulted devices seamlessly integrate the functionality of both FE-memristor (with ON-OFF ratios exceeding 105 and long-term retention) and metal-oxide-semiconductor field effect transistor (MOS-FET). Thus, it yields a prototype of gate tunable giant electroresistance with multi-levelled ON-states in the FE-memristor in the vertical vdW assembly. First-principles calculations further reveal that such behaviors originate from the specific band alignment between the FE-S interface. Our findings pave the way for the engineering of ferroelectricity-mediated memories in future implementations of 2D nanoelectronics.

A consensus on the management of allergy in kindergartens and primary schools / 中国学校卫生

Abstract@#Allergic diseases can occur in all systems of the body, covering the whole life cycle, from children to adults and to old age, can be lifelong onset and even fatal in severe cases. Children account for the largest proportion of the victims of allergic disease, Children s allergies start from scratch, ranging from mild to severe, from less to more, from single to multiple systems and systemic performance, so the prevention and treatment of allergic diseases in children is of great importance, which can not only prevent high risk allergic conditions from developing into allergic diseases, but also further block the process of allergy. At present, there is no consensus on the management system of allergic children in kindergartens and primary schools. The "Consensus on Allergy Management and Prevention in Kindergartens and Primary Schools", which includes the organizational structure, system construction and management of allergic children, provides evidence informed recommendations for the long term comprehensive management of allergic children in kindergartens and primary schools, and provides a basis for the establishment of the prevention system for allergic children.

Highly Water-Soluble Cucurbit[8]uril Derivative as a Broad-Spectrum Neuromuscular Block Reversal Agent.

Broad-spectrum agents for the reversal of residual curarization induced by neuromuscular blocking agents are of great significance. Here, we report a highly water-soluble cucurbit[8]uril (CB[8]) derivative as a broad-spectrum neuromuscular block reversal agent induced by both benzylisquinolinium and aminosteroid neuromuscular block agents by the supramolecular sequestration strategy. The UV/Vis competition titration assays suggest the high binding affinity of the CB[8] derivative toward both benzylisquinolinium-type cisatracurium besylate and aminosteroid-type rocuronium, vecuronium, and pancuronium, at the level of 107 M-1. In vivo studies demonstrate that the administration of the CB[8] derivative could significantly accelerate the recovery time compared to the placebo or neostigmine groups. The reversal activity of the CB[8] derivative is comparable to or higher than that of clinically approved sugammadex. Acute toxicity evaluations reveal that the CB[8]-derivative displays outstanding biocompatibility, with the maximum tolerance dose as high as 960 mg kg-1.

Supramolecular Organic Frameworks as Adsorbents for Efficient Removal of Excess Bilirubin in Hemoperfusion.

Excess bilirubin accumulates in the bodies of patients suffering from acute liver failure (ALF) to cause much irreversible damage and bring about serious clinical symptoms such as kernicterus, hepatic coma, or even death. Hemoperfusion is a widely used method for removing bilirubin from the blood, but clinically used adsorbents have unsatisfactory adsorption capacity and kinetics. In this study, we prepared four supramolecular organic framework microcrystals SOF-1-4 via slow evaporation of their aqueous solutions under infrared light. SOF-1-4 possess good regularity and excellent stability. We demonstrate that all the four SOFs could serve as adsorbents for bilirubin with fast adsorption kinetics within 20 min and ultrahigh adsorption capacity of 609.1 mg g-1, driven by electrostatic interaction and hydrophobicity. The superior adsorption performance of the SOFs outperformed most of the reported bilirubin adsorbents. Remarkably, SOF-3 could remove about 90% of bilirubin in the presence of 40 g L-1 BSA with a minimal loss of albumin and was thus further processed to a bead-shaped composite with a diameter of 2 mm with poly(ether sulfone) (PES). This PES-loaded SOF could efficiently adsorb bilirubin to the normal level from human plasma with an adsorption equilibrium concentration of 7.8 mg L-1 in 6 h through a dynamic hemoperfusion process. This work provides a new vitality for the development of novel bilirubin adsorbents for hemoperfusion therapy.

Doping Engineering in the MoS2 /SnSe2 Heterostructure toward High-Rejection-Ratio Solar-Blind UV Photodetection.

The intentionally designed band alignment of heterostructures and doping engineering are keys to implement device structure design and device performance optimization. According to the theoretical prediction of several typical materials among the transition metal dichalcogenides (TMDs) and group-IV metal chalcogenides, MoS2 and SnSe2 present the largest staggered band offset. The large band offset is conducive to the separation of photogenerated carriers, thus MoS2 /SnSe2 is a theoretically ideal candidate for fabricating photodetector, which is also verified in the experiment. Furthermore, in order to extend the photoresponse spectrum to solar-blind ultraviolet (SBUV), doping engineering is adopted to form an additional electron state, which provides an extra carrier transition channel. In this work, pure MoS2 /SnSe2 and doped MoS2 /SnSe2 heterostructures are both fabricated. In terms of the photoelectric performance evaluation, the rejection ratio R254 /R532 of the photodetector based on doped MoS2 /SnSe2 is five orders of magnitude higher than that of pure MoS2 /SnSe2 , while the response time is obviously optimized by 3 orders. The results demonstrate that the combination of band alignment and doping engineering provides a new pathway for constructing SBUV photodetectors.

Flexible organic frameworks sequester neuromuscular blocking agents in vitro and reverse neuromuscular block in vivo.

Supramolecular sequestration and reversal of neuromuscular block (NMB) have great clinical applications. Water-soluble flexible organic frameworks (FOFs) cross-linked by disulfide bonds are designed and prepared. Different linker lengths are introduced to FOFs to give them varied pore sizes. FOFs are anionic nanoscale polymers and capable of encapsulating cationic neuromuscular blocking agents (NMBAs), including rocuronium (Roc), vecuronium (Vec), pancuronium (Panc) and cisatracurium (Cis). A host-guest study confirms that FOFs bind NMBAs in water. The multivalency interaction between FOFs and NMBAs is able to sequester NMBAs, and prevent them from escaping. These FOFs are non-toxic and biocompatible. Animal studies show that FOFs are effective for the reversal of NMB induced by Roc, Vec and Cis, which shorten the time to a train-of-four ratio of 0.9 by 2.6, 3.8 and 5.7-fold compared to a placebo, respectively.

Conjugating aldoxorubicin to supramolecular organic frameworks: polymeric prodrugs with enhanced therapeutic efficacy and safety.

Phase I-III clinical studies show that aldoxorubicin (AlDox), a prodrug of doxorubicin (Dox), displays reduced cardiotoxicity compared to Dox, but does not demonstrate an overall survival benefit in patients. Here we report that three-dimensional supramolecular organic frameworks (SOFs) can conjugate AlDox through quantitative thiol-maleimide addition to afford two polymeric prodrugs of Dox. The previously established ability of SOFs in overcoming the multidrug resistance of tumor cells is utilized to achieve efficient intracellular delivery of the conjugated AlDox, which releases Dox as an active agent through acid-responsive hydrolysis of the hydrazone bond of AlDox within tumor cells. In vitro and in vivo experiments show that conjugation to SOF significantly improves the antitumor efficacy of AlDox as compared with free AlDox of the identical dose. Moreover, the SOF prodrugs do not show cardiotoxicity, the major superiority of AlDox over Dox. Since free AlDox is conjugated to endogenous albumin in the blood through thiol-maleimide addition to achieve enhanced intracellular delivery and Dox release through acid-responsive hydrazone hydrolysis, SOF conjugation provides a surrogate strategy for prodrug design to gain improved efficacy.

Porous Polymers as Universal Reversal Agents for Heparin Anticoagulants through an Inclusion-Sequestration Mechanism.

Heparins are widely used anticoagulants for surgical procedures and extracorporeal therapies. However, all of them have bleeding risks. Protamine sulfate, the only clinically approved antidote for unfractionated heparin (UFH), has adverse effects. Moreover, protamine can only partially neutralize low-molecular-weight heparins (LMWHs) and is not effective for fondaparinux. Here, an inclusion-sequestration strategy for efficient neutralization of heparin anticoagulants by cationic porous supramolecular organic frameworks (SOFs) and porous organic polymers (POPs) is reported. Isothermal titration calorimetric and fluorescence experiments show strong binding affinities of these porous polymers toward heparins, whereas dynamic light scattering and zeta potential analysis confirm that the heparin sequences are adsorbed into the interior of the porous hosts. Activated partial thromboplastin time, anti-FXa, and thromboelastography assays indicate that their neutralization efficacies are higher than or as high as that of protamine for UFH and generally superior to protamine for LMWHs and fondaparinux, which is further confirmed by tail-transection model in mice and ex vivo aPTT or anti-FXa analysis in rats. Acute toxicity evaluations reveal that one of the SOFs displays outstanding biocompatibility. This work suggests that porous polymers can supply safe and rapid reversal of clinically used heparins, as protamine surrogates, providing an improved approach for their neutralization.

Self-assembled nanoparticles based on supramolecular-organic frameworks and temoporfin for an enhanced photodynamic therapy in vitro and in vivo.

Water-soluble three-dimensional supramolecular-organic frameworks (SOFs) and temoporfin (mTHPC) are discovered to form uniform self-assembled nanoparticles. These nanoparticles demonstrate an improved 1O2 generation efficiency due to the reduced aggregation-caused quenching effect. SOFs and self-assembled nanoparticles are biocompatible. Self-assembled nanoparticles display an improved photo cytotoxicity toward four types of human cancer cells. The tumor model in mice shows that self-assembled nanoparticles could efficiently suppress tumor growth in vivo.

Polarimetric Image Sensor and Fermi Level Shifting Induced Multichannel Transition Based on 2D PdPS.

2D materials have been attracting high interest in recent years due to their low structural symmetry, excellent photoresponse, and high air stability. However, most 2D materials can only respond to specific light, which limits the development of wide-spectrum photodetectors. Proper bandgap and the regulation of Fermi level are the foundations for realizing electronic multichannel transition, which is an effective method to achieve a wide spectral response. Herein, a noble 2D material, palladium phosphide sulfide (PdPS), is designed and synthesized. The bandgap of PdPS is around 2.1 eV and the formation of S vacancies, interstitial Pd and P atoms promote the Fermi level very close to the conduction band. Therefore, the PdPS-based photodetector shows impressive wide spectral response from solar-blind ultraviolet to near-infrared based on the multichannel transition. It also exhibits superior optoelectrical properties with photoresponsivity (R) of 1 × 103 A W-1 and detectivity (D*) of 4 × 1011 Jones at 532 nm. Moreover, PdPS exhibits good performance of polarization detection with dichroic ratio of ≈3.7 at 808 nm. Significantly, it achieves polarimetric imaging and hidden-target detection in complex environments through active detection.

Defects Induced Charge Trapping/Detrapping and Hysteresis Phenomenon in MoS2 Field-Effect Transistors: Mechanism Revealed by Anharmonic Marcus Charge Transfer Theory.

One critical problem inhibiting the application of MoS2 field-effect transistors (FETs) is the hysteresis in their transfer characteristics, which is typically associated with charge trapping (CT) and charge detrapping (CDT) induced by atomic defects at the MoS2-dielectric interface. Here, we propose a novel atomistic framework to simulate electronic processes across the MoS2-SiO2 interface, demonstrating the distinct CT/CDT behavior of different types of atomic defects and further revealing the defect type(s) that most likely cause hysteresis. An anharmonic approximation of the classical Marcus theory is developed and combined with state-of-the-art density functional theory to calculate the gate bias-dependent CT/CDT rates. All the key electronic quantities are calculated with Heyd-Scuseria-Ernzerhof hybrid functionals. The results show that single Si-dangling bond defects are active electron trapping centers. Single O-dangling bond defects are active hole trapping centers, which are more likely to be responsible for the hysteresis phenomenon due to their significant CT rate and apparent threshold voltage shift. In contrast, double Si-dangling bond defects are not active trap centers. These findings provide fundamental physical insights for understanding the hysteresis behavior of MoS2 FETs and provide vital support for understanding and solving the reliability of nanoscale devices.

Wide-spectrum polarization-sensitive and fast-response photodetector based on 2D group IV-VI semiconductor tin selenide.

Tin selenide (SnSe) has attracted considerable interest recently on account of its low-symmetry lattice structure, great compatibility with key semiconductor technology, and remarkable electrical and optical performance. SnSe-based polarization-sensitive photodetectors show promising application prospects because of their fast response and excellent photoelectric performance. Here, an in-plane anisotropic SnSe nanosheet was synthesized and reported in detail by applying angle-resolved polarized Raman spectroscopy (ARPRS), polarization-resolved optical microscopy(PROM), angle-resolved optical absorption spectroscopy (AROAS), and other crystal structure characterization methods. Moreover, SnSe crystals exhibit superior polarization detection performance with a high anisotropic photocurrent ratio (2.31 at 1064 nm) due to the structure formed by the Van der Waals superposition of covalently bonded atomic layers. Furthermore, SnSe-based photodetectors have high responsivity (9.27 A/W), high detectivity (4.08 × 1010 Jones), and fast response (in the order of nanoseconds). These results suggest a new method for fabricating 2D fast-response polarization-sensitive photodetectors in the future.

Birefringence and Dichroism in Quasi-1D Transition Metal Trichalcogenides: Direct Experimental Investigation.

Birefringence and dichroism are very important properties in optical anisotropy. Understanding the intrinsic birefringence and dichroism of a material can provide great help to utilize its optical anisotropy. But the direct experimental investigation of birefringence in nanoscale materials is rarely reported. As typical anisotropic transition metals trichalcogenides (TMTCs) materials with quasi-1D structure, TiS3 and ZrS3 have attracted extensive attention due to their special crystal structure and optical anisotropy characteristics. Here, the optical anisotropy properties such as birefringence and dichroism of two kinds of quasi-1D TMTCs, TiS3 and ZrS3 , are theoretically and experimentally studied. In experimental results, the anisotropic refraction and anisotropic reflection of TiS3 and ZrS3 are studied by polarization-resolved optical microscopy and azimuth-dependent reflectance difference microscopy, respectively. In addition, the birefringence and dichroism of ZrS3 nanoribbon in experiment are directly measured by spectrometric ellipsometry measurements, and a reasonable result is obtained. This work provides the basic optical anisotropy information of TiS3 and ZrS3 . It lays a foundation for the further study of the optical anisotropy of these two materials and provides a feasible method for the study of birefringence and dichroism of other nanomaterials in the future.