Intercorrelated Ferroelectricity and Bulk Photovoltaic Effect in Two-Dimensional Sn2P2S6 Semiconductor for Polarization-Sensitive Photodetection

A two-dimensional (2D) ferroelectric semiconductor, which is coupled with photosensitivity and room-temperature ferroelectricity, provides the possibility of coordinated conductance modulation by both electric field and light illumination and is promising for triggering the revolution of optoelectronics for monolithic multifunctional integration. Here, we report that semiconducting Sn2P2S6 crystals can be achieved in a 2D morphology using a chemical vapor transport approach with the assistant of space confinement and experimentally demonstrate the robust ferroelectricity in atomic-thin Sn2P2S6 nanosheet at room temperature. The intercorrelated programming of ferroelectric order along out-of-plane (OOP) and in-plane (IP) directions enables a tunable bulk photovoltaic (BPV) effect through multidirectional electrical control. By combining the capability of anisotropic in-plane optical absorption, a highly integrated Sn2P2S6 optoelectronic device vertically sandwiched with graphene electrodes yields the polarization-dependent open-circuit photovoltage with a dichroic ratio of 2.0 under 405 nm light illumination. The reintroduction of ferroelectric Sn2P2S6 to the 2D asymmetric semiconductor family provides possibilities to hardware implement of the self-powered polarization-sensitive photodetection and spotlights the promising applications for next-generation photovoltaic devices.

Formulating N-Doped Carbon Hollow Nanospheres with Highly Accessible Through-Pores to Isolate Fe Single-Atoms for Efficient Oxygen Reduction

It is challenging yet promising to design highly accessible N-doped carbon skeletons to fully expose the active sites inside single-atom catalysts. Herein, mesoporous N-doped carbon hollow spheres with regulatable through-pore size can be formulated by a simple sequential synthesis procedure, in which the condensed SiO2 is acted as removable dual-templates to produce both hollow interiors and through-pores, meanwhile, the co-condensed polydopamine shell is served as N-doped carbon precursor. After that, Fe─N─C hollow spheres (HSs) with highly accessible active sites can be obtained after rationally implanting Fe single-atoms. Microstructural analysis and X-ray absorption fine structure analysis reveal that high-density Fe─N4 active sites together with tiny Fe clusters are uniformly distributed on the mesoporous carbon skeleton with abundant through-pores. Benefitted from the highly accessible Fe─N4 active sites arising from the unique through-pore architecture, the Fe─N─C HSs demonstrate excellent oxygen reduction reaction (ORR) performance in alkaline media with a half-wave potential up to 0.90 V versus RHE and remarkable stability, both exceeding the commercial Pt/C. When employing Fe─N─C HSs as the air-cathode catalysts, the assembled Zn-air batteries deliver a high peak power density of 204 mW cm-2 and stable discharging voltage plateau over 140 h.

Low-Potential Iodide Oxidation Enables Dual-Atom CoFe─N─C Catalysts for Ultra-Stable and High-Energy-Efficiency Zn-Air Batteries

The low energy efficiency and limited cycling life of rechargeable Zn-air batteries (ZABs) arising from the sluggish oxygen reduction/evolution reactions (ORR/OERs) severely hinder their commercial deployment. Herein, a zeolitic imidazolate framework (ZIF)-derived strategy associated with subsequent thermal fixing treatment is proposed to fabricate dual-atom CoFe─N─C nanorods (Co1 Fe1 ─N─C NRs) containing atomically dispersed bimetallic Co/Fe sites, which can promote the energy efficiency and cyclability of ZABs simultaneously by introducing the low-potential oxidation redox reactions. Compared to the mono-metallic nanorods, Co1 Fe1 ─N─C NRs exhibit remarkable ORR performance including a positive half-wave potential of 0.933 V versus reversible hydrogen electrode (RHE) in alkaline electrolyte. Surprisingly, after introducing the potassium iodide (KI) additive, the oxidation overpotential of Co1 Fe1 ─N─C NRs to reach 10 mA cm-2 can be significantly reduced by 395 mV compared to the conventional destructive OER. Theoretical calculations show that the markedly decreased overpotential of iodide oxidation can be ascribed to the synergistic effects of neighboring Co─Fe diatomic sites as the unique adsorption sites. Overall, aqueous ZABs assembled with Co1 Fe1 ─N─C NRs and KI as the air-cathode catalyst and electrolyte additive, respectively, can deliver a low charging voltage of 1.76 V and ultralong cycling stability of over 230 h with a high energy efficiency of ≈68%.

Defect Emission and Its Dipole Orientation in Layered Ternary Znln2 S4 Semiconductor

Defect engineering is promising to tailor the physical properties of 2D semiconductors for function-oriented electronics and optoelectronics. Compared with the extensively studied 2D binary materials, the origin of defects and their influence on physical properties of 2D ternary semiconductors are not clarified. Here, the effect of defects on the electronic structure and optical properties of few-layer hexagonal Znln2 S4 is thoroughly studied via versatile spectroscopic tools in combination with theoretical calculations. It is demonstrated that the Zn-In antistructural defects induce the formation of a series of donor and acceptor energy levels and sulfur vacancies induce donor energy levels, leading to rich recombination paths for defect emission and extrinsic absorption. Impressively, the emission of donor-acceptor pair in Znln2 S4 can be significantly tailored by electrostatic gating due to efficient tunability of Fermi level (Ef ). Furthermore, the layer-dependent dipole orientation of defect emission in Znln2 S4 is directly revealed by back focal plane imagining, where it presents obviously in-plane dipole orientation within a dozen-layer thickness of Znln2 S4 . These unique features of defects in Znln2 S4 including extrinsic absorption, rich recombination paths, gate tunability, and in-plane dipole orientation are definitely a benefit to the advanced orientation-functional optoelectronic applications.

[A multi-dimensional analysis of pollen broadcasting concerns in Chinese population: a large-scale multi-center cross-sectional survey]

Objective: To investigate the concern about pollen broadcasting in Chinese population from multiple dimensions and to understand the information about allergic rhinitis (AR) in China by analyzing related factors. Methods: From March 1 to September 30, 2022, a large-scale multi-center cross-sectional survey was conducted based on the Questionnaire Star platform in 21 Chinese hospitals. A total of 7 056 subjects from 7 regions in China: Northeast, North, East, Central, South, Southwest, and Northwest China were included. Basic characteristics (including social demographic characteristics and disease characteristics of AR patients), concern about pollen broadcasting, the willingness of pollen-induced AR (PiAR) patients to receive pollen broadcasting, and the treatment satisfaction rate of AR patients were collected. The chi-square test, multivariate linear regression model, and Logistic regression analysis were used to analyze the concern about pollen broadcasting in the Chinese population and related factors from multiple dimensions. Results: Among 7 056 subjects, 23.02% were concerned about pollen broadcasting. Among 3 176 self-reported AR and 1 019 PiAR patients, 25.60% and 39.16% were concerned about pollen broadcasting, respectively, which was higher than that of non-AR or non-PiAR subjects (χ2 value was 21.74 and 175.11, respectively, both P<0.001). Among AR patients, the proportion of spring and autumn allergen-positive patients concerned about pollen broadcasting was higher than that in perennial allergen-positive patients (χ2 value was 20.90 and 19.51, respectively, both P<0.001). The proportion of AR patients with asthma, sinusitis, allergic conjunctivitis, and cardiovascular and cerebrovascular diseases was higher than those without complications (χ2 value was 50.83, 21.97, 56.78, 7.62, respectively, all P<0.05). The proportion of AR patients in North China who could find pollen broadcasting locally was 31.01%, significantly higher than those in other regions (all P<0.05). Multivariate linear regression model analysis showed that among PiAR patients, those with higher per capita household income and higher AR disease cognition levels had been concerned about pollen broadcasting in the past, and those complicated with allergic conjunctivitis had stronger intention to receive pollen broadcasting (B value was 0.24, 0.13, 0.66, 0.47, respectively, all P<0.05). The higher the disease cognition level of PiAR patients, the stronger their willingness to actively participate in treatment (R2=0.72, P<0.001). Only 18.89% of AR patients felt satisfied with the treatment effect. Logistic regression analysis showed that in AR patients, the treatment satisfaction rate was significantly higher among those concerned about pollen broadcasting compared to those who were not (OR=1.83, P<0.001). Conclusions: Currently, the dissemination of pollen broadcasting in China is hindered by various factors such as disease cognition level. The treatment satisfaction among AR patients remains unsatisfactory.

[Analysis of the efficacy of transnasal endoscopic annulus of zinn area decompression in the treatment of dysthyroid optic neuropathy]

Objective: To evaluate the early efficacy and safety of transnasal endoscopic decompression in the annulus of zinn (AZ) region for refractory dysthyroid optic neuropathy (DON) and to preliminarily analyze the correlated factors of postoperative visual function outcome. Methods: From July 2021 to January 2023, 35 patients (56 eyes) with DON who received AZ area decompression in Peking University Third Hospital were included retrospectively, including 9 males (13 eyes) and 26 females (43 eyes), aging (52.2±12.0) years. Among them, 35 eyes underwent two-wall (medial and inferior) orbital decompression using an endonasal endoscopic approach, while 21 eyes received three-wall (medial, lateral, and inferior) orbital decompression through a combined approach. Key parameters such as best corrected visual acuity (BCVA), visual field (MD value), eyeball prominence, intraocular pressure, and complications were recorded. Postoperative data were collected one month after surgery. The statistical analysis was performed using paired t-test and Spearman correlation analysis. Results: Significant outcomes were observed post surgery in BCVA, visual field, intraocular pressure and proptosis (t value was 8.37, 6.17, 4.50, and 9.20, respectively, all P<0.001). The reduction in proptosis was statistically significant between the 2-wall and 3-wall orbital decompression groups (t=-2.82, P=0.007). Changes in BCVA, visual field, and intraocular pressure before and after surgery was greater in the 3-wall orbital decompression group compared to 2-wall orbital decompression group, although the difference was not statistically significant (all P>0.05). Change in postoperative visual acuity and visual field was significantly positively correlated with preoperative visual acuity and preoperative visual field (all P<0.001). Similarly, change in intraocular pressure and proptosis was positively correlated with preoperative intraocular pressure and preoperative protrusion (all P<0.001). Preoperative diplopia was reported in seven patients (20.0%), and two new cases (5.7%) were noted post-operation, which resolved within 3 months after surgery. Conclusions: Endoscopic endonasal decompression of the AZ area is a safe and effective surgical treatment for DON, with notable improvements in BCVA. Furthermore, three-orbital wall decompression seems to yield better outcomes in terms of eye retraction.

Neuro-inspired optical sensor array for high-accuracy static image recognition and dynamic trace extraction

Neuro-inspired vision systems hold great promise to address the growing demands of mass data processing for edge computing, a distributed framework that brings computation and data storage closer to the sources of data. In addition to the capability of static image sensing and processing, the hardware implementation of a neuro-inspired vision system also requires the fulfilment of detecting and recognizing moving targets. Here, we demonstrated a neuro-inspired optical sensor based on two-dimensional NbS2/MoS2 hybrid films, which featured remarkable photo-induced conductance plasticity and low electrical energy consumption. A neuro-inspired optical sensor array with 10 × 10 NbS2/MoS2 phototransistors enabled highly integrated functions of sensing, memory, and contrast enhancement capabilities for static images, which benefits convolutional neural network (CNN) with a high image recognition accuracy. More importantly, in-sensor trajectory registration of moving light spots was experimentally implemented such that the post-processing could yield a high restoration accuracy. Our neuro-inspired optical sensor array could provide a fascinating platform for the implementation of high-performance artificial vision systems.

Revisiting the Hetero-Interface of Electrolyte/2D Materials in an Electric Double Layer Device

Electric double layer (EDL) devices based on 2D materials have made great achievements for versatile electronic and opto-electronic applications; however, the ion dynamics and electric field distribution of the EDL at the electrolyte/2D material interface and their influence on the physical properties of 2D materials have not been clearly clarified. In this work, by using Kelvin probe force microscope and steady/transient optical techniques, the character of the EDL and its influence on the optical properties of monolayer transition metal dichalcogenides (TMDs) are probed. The potential drop, unscreened EDL potential distribution, and accumulated carriers at the electrolyte/TMD interface are revealed, which can be explained by nonlinear Thomas-Fermi theory. By monitoring the potential distribution along the channel, the evolution of the electric field-induced lateral junction in the TMD EDL transistor is accessed, giving rise to the better exploration of EDL device physics. More importantly, EDL gate-dependent carrier recombination and exciton-exciton annihilation in monolayer TMDs on lithium-ion solid state electrolyte (Li2 Al2 SiP2 TiO13 ) are evaluated for the first time, benefiting from the understanding of the interaction between ions, carriers, and excitons. The work will deepen the understanding of the EDL for the exploitation of functional device applications.

[The rise and fall of the leprosy clinic in Ru Gao in the North of Jiangsu in the period of the Republic of China]

The North of Jiangsu was a traditional area for leprosy in Chinese history. In the period of the Republic of China, one of the largest leprosy clinics in China was established in Ru Gao (Jugao) with the help of Chinese and foreign charitable organizations, the Chinese central government and some squires. It was the only large clinic for leprosy in the North of Jiangsu. It was officially opened in 1924, attached to the Presbyterian Church hospital, and was closed in 1927 after the breakout of the civil war. It reopened in May 1933, hosted by a leprologist, Lee S. Huizenga. Ru Gao (Jugao) leprosy clinic treated around 1,000 lepers in the North of Jiangsu with medicines and language communication. The establishment of the leprosy clinic made a historical contribution in terms of preventing leprosy from spreading to Shanghai. It closed in the spring of 1938 because of the invasion of the Japanese military.

Synaptic plasticity realized by selective oxidation of TiS3 nanosheet for neuromorphic devices

Memristive devices operating analogous to biology synapses demonstrate great potential for neuromorphic applications. Here, we reported the space-confined vapor synthesis of ultrathin titanium trisulfide (TiS₃) nanosheets, and subsequent laser manufacturing of a TiS₃-TiO_x-TiS₃ in-plane heterojunction for memristor applications. Due to the flux-controlled migration and aggregation of oxygen vacancies, the two-terminal memristor demonstrates reliable "analog" switching behaviors, in which the channel conductance can be incrementally adjusted by tuning the duration and sequence of programming voltage. The device allows the emulation of basic synaptic functions, featuring excellent linearity and symmetry in conductance change during long-term potentiation/depression processes. The small asymmetric ratio of 0.15 enables it to be integrated into a neural network for the pattern recognition task with a high accuracy of 90%. The results demonstrate the great potential of TiS₃-based synaptic devices for neuromorphic applications.

Two-dimensional semiconducting SnP2Se6 with giant second-harmonic-generation for monolithic on-chip electronic-photonic integration

Two-dimensional (2D) layered semiconductors with nonlinear optical (NLO) properties hold great promise to address the growing demand of multifunction integration in electronic-photonic integrated circuits (EPICs). However, electronic-photonic co-design with 2D NLO semiconductors for on-chip telecommunication is limited by their essential shortcomings in terms of unsatisfactory optoelectronic properties, odd-even layer-dependent NLO activity and low NLO susceptibility in telecom band. Here we report the synthesis of 2D SnP₂Se₆, a van der Waals NLO semiconductor exhibiting strong odd-even layer-independent second harmonic generation (SHG) activity at 1550 nm and pronounced photosensitivity under visible light. The combination of 2D SnP₂Se₆ with a SiN photonic platform enables the chip-level multifunction integration for EPICs. The hybrid device not only features efficient on-chip SHG process for optical modulation, but also allows the telecom-band photodetection relying on the upconversion of wavelength from 1560 to 780 nm. Our finding offers alternative opportunities for the collaborative design of EPICs.

Self-Sacrificing Template Synthesis of Carbon Nanosheets Assembled Hollow Spheres with Abundant Active Fe-N4 O1 Moieties for Electrocatalytic Oxygen Reduction

Single-atom Fe-N-C (Fe₁ -N-C) materials represent the benchmarked electrocatalysts for oxygen reduction reaction (ORR). However, single Fe atoms in the carbon skeletons cannot be fully utilized due to the mass transfer limitation, severely restricting their intrinsic ORR properties. Herein, a self-sacrificing template strategy is developed to fabricate ultrathin nanosheets assembled Fe₁ -N-C hollow microspheres (denoted as Fe₁ /N-HCMs) by rational carbonization of Fe³⁺ chelating polydopamine coated melamine cyanuric acid complex. The shell of Fe₁ /N-HCMs is constructed by ultrathin nanosheets with thickness of only 2 nm, which is supposed to be an ideal platform to isolate and fully expose single metal atoms. Benefiting from unique hierarchical hollow architecture with highly open porous structure, 2 nm-thick ultrathin nanosheet subunits and abundant Fe-N₄ O₁ active sites revealed by X-ray absorption fine structure analysis, the Fe₁ /N-HCMs exhibit high ORR performance with a positive half-wave potential of 0.88 V versus the reversible hydrogen electrode and robust stability. When served as air-cathode catalysts with ultralow loading mass of 0.25 mg cm^-2 , Fe₁ /N-HCMs based Zn-air batteries present a maximum power density of 187 mW cm^-2 and discharge specific capacity of 806 mA h g_Zn ^-1 in primary Zn-air batteries, all exceeding those of commercial Pt/C.

[Correlation analysis between prenatal exposure of per-/polyfluoroalkyl compounds and neonatal outcome]

Objective: To investigate the correlation between the prenatal exposure of per-/polyfluoroalkyl substances (PFASs) and the neonatal outcome. Methods: A total of 506 maternal infant cohort samples were collected in Hangzhou, Zhejiang province from 2020 to 2021. The exposure levels of seven PFASs in maternal serum before delivery were detected by solid-phase extraction-ultra performance liquid chromatography tandem mass spectrometry. Multivariable linear regression model was used to analyze the influence of prenatal exposure of PFASs on birth weight, birth length and Apgar score. Results: The maternal age, prenatal body mass index and gestation age were (31.3±4.3) years old, (26.7±3.2) kg/m² and (265.0±28.3) days, respectively. The birth weight, birth length and scores of Apgar-1 and Apgar-5 were (3.1±0.8) kg, (49.3±2.9) cm, (9.88±0.47) points and (9.99±0.13) points, respectively. PFASs were widely distributed in maternal serum, with the highest concentration of (18.453±19.557) ng/ml, (6.756±9.379) ng/ml and (5.057±8.555) ng/ml for perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and 6∶2 chlorinated polyfluorinated ether sulfonate (Cl-PFESA), respectively. Maternal age, parity and delivery mode were associated with the exposure level of PFASs (P<0.05). Subgroup analysis showed that PFOS had negative effects on birth weight (β=-0.958), birth length (β=-0.073) and Apgar-5 score (β=-0.288) for neonates in the low birth weight (LBW) group. 6∶2 Cl-PFESA and 8∶2 Cl-PFESA inhibited the birth weight (β=-0.926; β=-0.552) and length (β=-0.074; β=-0.045) of newborn in the LBW group. In addition, 4∶2 fluorotelomer sulfonate (FTS) was associated with increased birth weight (β=0.111) and decreased Apgar-5 score (β=-0.030) in the normal weight group. Conclusion: Prenatal exposure to PFASs is associated with birth weight, birth length and Apgar-5 score. It is necessary to continue to pay attention to the impact of PFASs on fetal growth and development through maternal-fetal transmission.

A polarization-sensitive photothermoelectric photodetector based on mixed-dimensional SWCNT-MoS2 heterostructures

Mixed-dimensional van der Waals (vdW) integration has been demonstrated to be effective for the modulation of the physical properties of homogeneous materials. Herein, we reported the enhancement of photothermal conversion and decrease of thermal conductivity in metallic single-walled carbon nanotube (SWCNT) films with the integration of chemical vapor deposition-grown monolayer MoS₂ films. The induced temperature gradient in SWCNT-MoS₂ hybrid films drives carrier diffusion to generate photocurrent via the photothermoelectric (PTE) effect, and a self-powered photodetector working in the visible band range from 405 to 785 nm was demonstrated. The maximum responsivity of the device increases by 6 times compared to that of the SWCNT counterpart. More importantly, the mixed-dimensional device exhibits polarization-dependent photogeneration, showing a large anisotropy ratio of 1.55. This work paves a way for developing high-performance, polarization-sensitive photodetectors by mixed-dimensional integration.

Isolating Fe Atoms in N-Doped Carbon Hollow Nanorods through a ZIF-Phase-Transition Strategy for Efficient Oxygen Reduction

Transition metal-nitrogen-carbon (TM-N-C) catalysts have been intensely investigated to tackle the sluggish oxygen reduction reactions (ORRs), but insufficient accessibility of the active sites limits their performance. Here, by using solid ZIF-L nanorods as self-sacrifice templates, a ZIF-phase-transition strategy is developed to fabricate ZIF-8 hollow nanorods with open cavities, which can be subsequently converted to atomically dispersed Fe-N-C hollow nanorods (denoted as Fe₁ -N-C HNRs) through rational carbonization and following fixation of iron atoms. The microstructure observation and X-ray absorption fine structure analysis confirm abundant Fe-N₄ active sites are evenly distributed in the carbon skeleton. Thanks to the highly accessible Fe-N₄ active sites provided by the highly porous and open carbon hollow architecture, the Fe₁ -N-C HNRs exhibit superior ORR activity and stability in alkaline and acidic electrolytes with very positive half-wave potentials of 0.91 and 0.8 V versus RHE, respectively, both of which surpass those of commercial Pt/C. Remarkably, the dynamic current density (J_K ) of Fe₁ -N-C HNRs at 0.85 V versus RHE in alkaline media delivers a record value of 148 mA cm^-2 , 21 times higher than that of Pt/C. The assembled Zn-air battery using Fe₁ -N-C HNRs as cathode catalyst exhibits a high peak power density of 208 mW cm^-2 .

A medium-entropy transition metal oxide cathode for high-capacity lithium metal batteries

The limited capacity of the positive electrode active material in non-aqueous rechargeable lithium-based batteries acts as a stumbling block for developing high-energy storage devices. Although lithium transition metal oxides are high-capacity electrochemical active materials, the structural instability at high cell voltages (e.g., >4.3 V) detrimentally affects the battery performance. Here, to circumvent this issue, we propose a Li_1.46Ni_0.32Mn_1.2O_4-x (0 < x < 4) material capable of forming a medium-entropy state spinel phase with partial cation disordering after initial delithiation. Via physicochemical measurements and theoretical calculations, we demonstrate the structural disorder in delithiated Li_1.46Ni_0.32Mn_1.2O_4-x, the direct shuttling of Li ions from octahedral sites to the spinel structure and the charge-compensation Mn³⁺/Mn⁴⁺ cationic redox mechanism after the initial delithiation. When tested in a coin cell configuration in combination with a Li metal anode and a LiPF₆-based non-aqueous electrolyte, the Li_1.46Ni_0.32Mn_1.2O_4-x-based positive electrode enables a discharge capacity of 314.1 mA h g⁻¹ at 100 mA g⁻¹ with an average cell discharge voltage of about 3.2 V at 25 ± 5 °C, which results in a calculated initial specific energy of 999.3 Wh kg⁻¹ (based on mass of positive electrode’s active material).

Structural instability is a major drawback of high-capacity lithium-based battery cathodes. Here, the authors report a cathode active material with a medium-entropy state created by partial cation disordering capable of restraining the structural evolution in the high-capacity operated spinel phase.

[Relationship between onco-immunological and morphologic characteristics of lymphoepithelioma-like carcinoma and lymphocyte subtypes of peripheral blood]

Objective: To study the relationship between the onco-immunological and morphologic characteristics of lymphoepithelioma-like carcinoma (LELC) and peripheral blood lymphocyte subtypes and its clinical significance. Methods: The pathologic and clinical data of 117 LELC patients who were admitted to the Tumor Hospital of the University of Chinese Academy of Sciences from 2006 to 2018 were collected. The histological classification was based on previously reported morphological classification method. The onco-immunological and morphologic characteristics of the tumors such as lymphoid follicle formation and interstitial fibrous hyperplasia, patient's peripheral blood lymphocyte subtypes and prognosis data were collected. The relationship between various factors and their impact on prognosis were analyzed. Results: There were 117 patients, including 61 females and 56 males. The male to female ratio was 0.9∶1.0. The age of onset was 24-89 years (median 52 years). Primary sites included head and neck (68 cases), lungs (26 cases), stomach (15 cases), and others (eight cases). Morphologically, 54 cases were type Ⅰ, 62 cases were type Ⅱ, and one case could not be classified. The onco-immunological and morphologic features of the LELC tumors showed a continuous spectrum. Interstitial TILs were noted from focally to diffuse, and the interstitial fibrous tissues were from hardly visible to obvious sclerotic. Formation of lymphoid follicles was seen in 42 patients; obvious fibrosis was seen in 31 cases. Data of peripheral blood lymphocyte subtyping by flow cytometry were available in 73 cases. These data included CD3⁺total T cells, CD3⁺CD4⁺helper T cells, CD3⁺CD8⁺cytotoxic T cells, CD3^-CD56⁺natural killer (NK) cells, CD3^-CD19⁺B cells, CD4⁺CD45RA^-T helper induction subgroup, CD4⁺CD45RA⁺ T suppression induction subgroup, CD4⁺CD45RO⁺memory T cell subgroup, CD45RA⁺CD45RO⁺activated T cell subgroup, CD8⁺CD38⁺activated cytotoxic T cell, and CD25⁺lymphocytes and CD44⁺lymphocyte. The proportion of lymphocytes of each subtype was normal in most patients, but the proportion of CD44⁺lymphocytes in 61 cases (83.6%) was increased; the proportion of T cell suppression induced subgroups was decreased in 53 cases (72.6%). Correlation analysis found a significant correlation between clinical stage and NK cells (P=0.023); tumor histologic type and cytotoxic T cells were significantly positively correlated (P=0.012); while tumor cell morphologic differentiation was significantly related to total T cells (P=0.003) and NK cells (P=0.026); Formation of interstitial lymphoid follicles was positively correlated with memory T cell subsets (P=0.025); Tumor interstitial fibrosis was significantly positively correlated with T suppression-induced subpopulations (P=0.004), and was significantly negatively correlated with total T cells (P=0.023) and with the expression of CD44 adhesion molecules (P=0.003). Survival analysis found that lymphoid follicle formation was a favorable prognostic factor for LELC (P=0.001). Conclusions: The onco-immunological and morphologic features in LELC show a continuous spectrum; the tumor clinicopathological characteristics and onco-immunological morphology are closely related to peripheral blood T lymphocyte subtypes, and the formation of interstitial lymphoid follicles is a favorable prognostic factor for LELC.

[Surgical treatment of papillary thyroid carcinoma involving larynx and trachea]

Objective: To evaluate the efficacy of surgical treatment of papillary thyroid carcinoma (PTC) involving larynx and trachea. Methods: A total of 1 436 cases of thyroid malignant tumors were admitted to the Department of Otolaryngology, Qilu Hospital of Shandong University from 2004 to 2019, including 110 cases of PTC involving larynx and trachea, and of which 105 cases with complete follow-up data were retrospectively analyzed. There were 42 males and 63 females, with a male/female ratio of 1∶1.5, aged from 28 to 81 years. All lesions involved trachea, including 11 cases involving both trachea and larynx. Of those 83 cases underwent laryngeal and airway wall tumor excision, and 22 cases underwent radical tumor excision plus laryngeal and trachea repair. Extubation rate was analyzed and the postoperative survival curve of patients was analyzed by Kaplan-Meier method. Results: Among 105 cases, 16 cases underwent tracheotomy and 12 cases were successfully extubated. The overall 3- 5- and 10-year survival rates were 100.0%, 86.4% and 72.5%, and the disease-free survival rates were 93.1%, 81.6% and 57.7%, respectively. There was significant difference in survival curve between the two groups (χ²=4.21, P=0.040). The 5-year and 10-year survival rates were 94.6% and 77.3% in laryngeal and tracheal tumor exclusion group, and 85.7% and 51.4% in the radical tumor resection group. There was no significant difference in the survival curves between the two groups (χ²=3.50, P=0.061). Conclusion: PTC patients with laryngeal and tracheal involvement can achieve long survival and good quality of life through reasonable surgical treatment.

Transition Metal (Co, Ni, Fe, Cu) Single-Atom Catalysts Anchored on 3D Nitrogen-Doped Porous Carbon Nanosheets as Efficient Oxygen Reduction Electrocatalysts for Zn-Air Battery

Exploring highly active and cost-efficient single-atom catalysts (SACs) for oxygen reduction reaction (ORR) is critical for the large-scale application of Zn-air battery. Herein, density functional theory (DFT) calculations predict that the intrinsic ORR activity of the active metal of SACs follows the trend of Co > Fe > Ni ≈ Cu, in which Co SACs possess the best ORR activity due to its optimized spin density. Guided by DFT calculations, four kinds of transition metal single atoms embedded in 3D porous nitrogen-doped carbon nanosheets (MSAs@PNCN, M = Co, Ni, Fe, Cu) are synthesized via a facile NaCl-template assisted strategy. The resulting MSAs@PNCN displays ORR activity trend in lines with the theoretical predictions, and the Co SAs@PNCN exhibits the best ORR activity (E_1/2  = 0.851 V), being comparable to that of Pt/C under alkaline conditions. X-ray absorption fine structure (XAFS) spectra verify the atomically dispersed Co-N₄ sites are the catalytically active sites. The highly active CoN₄ sites and the unique 3D porous structure contribute to the outstanding ORR performance of Co SAs@PNCN. Furthermore, the Co SAs@PNCN catalyst is employed as cathode in Zn-air battery, which can deliver a large power density of 220 mW cm^-2 and maintain robust cycling stability over 530 cycles.

Bifunctional WC-Supported RuO2 Nanoparticles for Robust Water Splitting in Acidic Media

We report the strong catalyst-support interaction in WC-supported RuO₂ nanoparticles (RuO₂ -WC NPs) anchored on carbon nanosheets with low loading of Ru (4.11 wt.%), which significantly promotes the oxygen evolution reaction activity with a η₁₀ of 347 mV and a mass activity of 1430 A g_Ru ^-1 , eight-fold higher than that of commercial RuO₂ (176 A g_Ru ^-1 ). Theoretical calculations demonstrate that the strong catalyst-support interaction between RuO₂ and the WC support could optimize the surrounding electronic structure of Ru sites to reduce the reaction barrier. Considering the likewise excellent catalytic ability for hydrogen production, an acidic overall water splitting (OWS) electrolyzer with a good stability constructed by bifunctional RuO₂ -WC NPs only requires a cell voltage of 1.66 V to afford 10 mA cm^-2 . The unique 0D/2D nanoarchitectures rationally combining a WC support with precious metal oxides provides a promising strategy to tradeoff the high catalytic activity and low cost for acidic OWS applications.

[Pathological features related to onco-immunity and their clinical significance of pancreatic ductal adenocarcinoma]

Objective: To investigate the tumor immunity-related pathologic features and clinical significance in pancreatic ductal adenocarcinoma (PDAC). Methods: All pathologic materials and clinical information of 192 PDAC patients from the Cancer Hospital of the University of Chinese Academy of Sciences from January 2010 to December 2020 were collected. The onco-immune microenvironment associated morphologic features were evaluated, and MHC-Ⅰ, PD-L1, CD3, and CD8 expression were detected by immunohistochemistry (IHC). Then the correlation between the factors and their influence on prognosis was analyzed. Results: There were 163 cases of non-specific adenocarcinoma (163/192, 84.90%), 18 cases of adeno-squamous carcinoma (18/192, 9.37%), and 11 cases of other rare subtypes (11/192, 5.73%). Perineural invasion was observed in 110 cases (110/192, 57.29%) and vascular invasion in 86 cases (86/192, 44.79%). There were 84 cases (84/182, 46.15%) with severe chronic inflammation. Tumor infiltrating immune cell numbers (TII-N) were increased in 52 cases (52/192, 27.08%). Lymphocytes and plasma cells were the main infiltrating immune cells in 60 cases (60/192, 31.25%), whereas in 34 cases (34/192, 17.71%) the tumors were mainly infiltrated by granulocytes, and 98 cases (98/192, 51.04%) showed mixed infiltration. CD3+T cells were deficient in 124 cases (124/192, 66.31%). CD8+T cells were deficient in 152 cases (152/192, 79.58%). MHC-Ⅰ expression was down-regulated in 156 cases (156/192, 81.25%), and PD-L1 was positive (CPS≥1) in 46 cases (46/192, 23.96%). Statistical analysis showed that TII-N was negatively correlated with vascular invasion (P=0.035), perineural invasion (P=0.002), stage (P=0.004) and long-term alcohol consumption (P=0.039). The type of immune cells correlated positively with chronic pancreatic inflammation (P=0.002), and negatively with tumor differentiation (P=0.024). CD8+T cells were positively correlated with CD3+T cells (P=0.032), MHC-Ⅰ expression (P<0.001) and PD-L1 expression (P=0.001), and negatively correlated with long-term smoking (P=0.016). Univariate analysis showed that histological nonspecific type (P=0.013) and TII-N (P<0.001) were the factors for good prognosis. Vascular invasion (P=0.032), perineural invasion (P=0.001), high stage (P=0.003) and long-term alcohol consumption (P=0.004) were adverse prognostic factors. COX multivariate risk analysis found that TII-N was an independent favorable factor for PDAC, while perineural invasion was an independent adverse risk factor. Conclusions: TII-N is an independent superior prognostic factor for PDAC, and significantly correlated with many factors; chronic alcohol consumption and smoking may inhibit onco-immunity in PDAC patients.

2D Indium Phosphorus Sulfide (In2 P3 S9 ): An Emerging van der Waals High-k Dielectrics

2D van der Waals (vdW) semiconductors hold great potentials for more-than-Moore field-effect transistors (FETs), and the efficient utilization of their theoretical performance requires compatible high-k dielectrics to guarantee the high gate coupling efficiency. The deposition of traditional high-k dielectric oxide films on 2D materials usually generates interface concerns, thereby causing the carrier scattering and degeneration of device performance. Here, utilizing a space-confined epitaxy growth approach, the authors successfully obtained air-stable ultrathin indium phosphorus sulfide (In₂ P₃ S₉ ) nanosheets, the thickness of which can be scaled down to monolayer limit (≈0.69 nm) due to its layered structure. 2D In₂ P₃ S₉ exhibits excellent insulating properties, with a high dielectric constant (≈24) and large breakdown voltage (≈8.1 MV cm^-1 ) at room temperature. Serving as gate insulator, ultrathin In₂ P₃ S₉ nanosheet can be integrated into MoS₂ FETs with high-quality dielectric/semiconductor interface, thus providing a competitive electrical performance of device with subthreshold swings (SS) down to 88 mV dec^-1 and a high ON/OFF ratio of 10⁵ . This study proves an important strategy to prepare 2D vdW high-k dielectrics, and greatly facilitates the ongoing research of 2D materials for functional electronics.

Limonitum Ameliorates Castor Oil-Induced Diarrhoea in Mice by Modulating Gut Microbiota

Diarrhoea is a common clinical condition; its pathogenesis is strongly associated with gut microbiota dysbiosis. Limonitum is a well-known traditional Chinese medicine that exerts appreciable benefits regarding the amelioration of diarrhoea. However, the mechanism through which Limonitum ameliorates diarrhoea remains unclear. Here, the efficacy and underlying mechanism of Limonitum decoction (LD) regarding diarrhoea were explored from the aspect of gut microbiota. Castor oil (CO) was used to induce diarrhoea in mice, which were then used to evaluate the effects of LD regarding the timing of the first defecation, diarrhoea stool rate, degree of diarrhoea, diarrhoea score, intestinal propulsive rate, and weight of intestinal contents. The concentrations of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric and valeric acids, were analysed by gas chromatography-mass spectrometry (GC-MS). The 16S rRNA high-throughput sequencing technology was applied to evaluate changes in the gut microbiota under exposure to LD. LD was found to effectively ameliorate the symptoms of diarrhoea, and the diversity and relative abundance of gut microbiota were restored to normal levels following LD treatment. Additionally, LD significantly restored the observed reductions in SCFAs. These results provide strong evidence that LD can sufficiently ameliorate diarrhoea in mice by regulating their gut microbiota. The findings presented here highlight that Limonitum may constitute a prospective remedy for diarrhoea.

Multifunctional Chiral Three-Dimensional Phosphite Frameworks Showing Dielectric Anomaly and High Proton Conductivity

Chair 3D Co(II) phosphite frameworks have been prepared by the ionothermal method. It belongs to chiral space group P3₂21, and the whole framework can be topologically represented as a chiral 4-connected qtz net. It shows a multistep dielectric response arising from the reorientation of Me₂-DABCO in the chiral cavities. It can also serve as a pron conductor with high conductivity, 1.71 × 10^-3 S cm^-1, at room temperature, which is attributed to the formation of denser hydrogen-bonding networks providing efficient proton-transfer pathways.

Mechanical Anisotropy in Two-Dimensional Selenium Atomic Layers

Two-dimensional (2D) trigonal selenium (t-Se) has become a new member in 2D semiconducting nanomaterial families. It is composed of well-aligned one-dimensional Se atomic chains bonded via van der Waals (vdW) interaction. The contribution of this unique anisotropic nanostructure to its mechanical properties has not been explored. Here, for the first time, we combine experimental and theoretical analyses to study the anisotropic mechanical properties of individual 2D t-Se nanosheets. It was found that its fracture strength and Young's modulus parallel to the atomic chain direction are much higher than along the transverse direction, which was attributed to the weak vdW interaction between Se atomic chains as compared to the covalent bonding within individual chains. Additionally, two distinctive fracture modes along two orthogonal loading directions were identified. This work provides important insights into the understanding of anisotropic mechanical behaviors of 2D semiconducting t-Se and opens new possibilities for future applications.

2D-1D mixed-dimensional heterostructures: progress, device applications and perspectives

Two-dimensional (2D) materials have attracted broad interests and been extensively exploited for a variety of functional applications. Moreover, one-dimensional (1D) atomic crystals can also be integrated into 2D templates to create mixed-dimensional heterostructures, and the versatility of combinations provides 2D-1D heterostructures plenty of intriguing physical properties, making them promising candidate to construct novel electronic and optoelectronic nanodevices. In this review, we first briefly present an introduction of relevant fabrication methods and structural configurations for 2D-1D heterostructures integration. We then discuss the emerged intriguing physics, including high optical absorption, efficient carrier separation, fast charge transfer and plasmon-exciton interconversion. Their potential applications such as electronic/optoelectronic devices, photonic devices, spintronic devices and gas sensors, are also discussed. Finally, we provide a brief perspective for the future opportunities and challenges in this emerging field.

Topotactic Growth of Free-Standing Two-Dimensional Perovskite Niobates with Low Symmetry Phase

Here, we report a novel topotactic method to grow 2D free-standing perovskite using KNbO₃ (KN) as a model system. Perovskite KN with monoclinic phase, distorted by as large as ∼6 degrees compared with orthorhombic KN, is obtained from 2D KNbO₂ after oxygen-assisted annealing at relatively low temperature (530 °C). Piezoresponse force microscopy (PFM) measurements confirm that the 2D KN sheets show strong spontaneous polarization (P_s) along [101̅]_pc direction and a weak in-plane polarization, which is consistent with theoretical predictions. Thickness-dependent stripe domains, with increased surface displacement and PFM phase changes, are observed along the monoclinic tilt direction, indicating the preserved strain in KN induces the variation of nanoscale ferroelectric properties. 2D perovskite KN with low symmetry phase stable at room temperature will provide new opportunities in the exploration of nanoscale information storage devices and better understanding of ferroelectric/ferroelastic phenomena in 2D perovskite oxides.

Lowering the Contact Barriers of 2D Organic F16 CuPc Field-Effect Transistors by Introducing Van der Waals Contacts

2D organic crystals exhibit efficient charge transport and field-effect characteristics, making them promising candidates for high-performance nanoelectronics. However, the strong Fermi level pinning (FLP) effect and large Schottky barrier between organic semiconductors and metals largely limit device performance. Herein, by carrying out temperature-dependent transport and Kelvin probe force microscopy measurements, it is demonstrated that the introducing of 2D metallic 1T-TaSe₂ with matched band-alignment as electrodes for F₁₆ CuPc nanoflake filed-effect transistors leads to enhanced field-effect characteristics, especially lowered Schottky barrier height and contact resistance at the contact and highly efficient charge transport within the channel, which are attributed to the significantly suppressed FLP effect and appropriate band alignment at the nonbonding van der Waals (vdW) hetero-interface. Moreover, by taking advantage of the improved contact behavior with 1T-TaSe₂ contact, the optoelectronic performance of F₁₆ CuPc nanoflake-based phototransistor is drastically improved, with a maximum photoresponsivity of 387 A W^-1 and detectivity of 3.7 × 10¹⁴ Jones at quite a low V_ds of 1 V, which is more competitive than those of the reported organic photodetectors and phototransistors. The work provides an avenue to improve the electrical and optoelectronic properties of 2D organic devices by introducing 2D metals with appropriate work function for vdW contacts.

Electrochemical Intercalation in Atomically Thin van der Waals Materials for Structural Phase Transition and Device Applications

In van der Waals (vdWs) materials and heterostructures, the interlayers are bonded by weak vdWs interactions due to the lack of dangling bonds. The vdWs gap at the homo- or heterointerface provides great freedom to enrich the tunability of electronic structures by external intercalation of foreign ions or atoms at the interface, leading to the discovery of new physics and functionalities. Herein, the recent progress on electrochemical intercalation of foreign species into atomically thin vdWs materials for structural phase transition and device applications is reviewed and future opportunities are discussed. First, several kinds of electrochemical intercalation platforms to achieve the intercalation in vdWs materials and heterostructures are introduced. Next, the in situ characterization of electrochemical intercalation dynamics by state-of-the-art techniques is summarized, including optical techniques, scanning probe techniques, and electrical transport. Moreover, particular attention is paid on the experimentally reported phase transition and multifunctional applications of intercalated devices. Finally, future applications and challenges of intercalation in vdWs materials and heterostructures are proposed, including the intrinsic intercalation mechanism of solid ion conductors, exact identification of intercalated foreign species by near-field optical techniques, and the tunability of intercalation kinetics for ultrafast switching.

Tiny 2D silicon quantum sheets: a brain photonic nanoagent for orthotopic glioma theranostics

We report that atomically thin two-dimensional silicon quantum sheets (2D Si QSs), prepared by a scalable approach coupling chemical delithiation and cryo-assisted exfoliation, can serve as a high-performance brain photonic nanoagent for orthotopic glioma theranostics. With the lateral size of approximately 14.0 nm and thickness of about 1.6 nm, tiny Si QSs possess high mass extinction coefficient of 27.5 L g^-1 cm^-1 and photothermal conversion efficiency of 47.2% at 808 nm, respectively, concurrently contributing to the best photothermal performance among the reported 2D mono-elemental materials (Xenes). More importantly, Si QSs with low toxicity maintain the trade-off between stability and degradability, paving the way for practical clinical translation in consideration of both storage and action of nanoagents. In vitro Transwell filter experiment reveals that Si QSs could effectively go across the bEnd.3 cells monolayer. Upon the intravenous injection of Si QSs, orthotopic brain tumors are effectively inhibited under the precise guidance of photoacoustic imaging, and the survival lifetime of brain tumor-bearing mice is increased by two fold. Atomically thin Si QSs with strong light-harvesting capability are expected to provide an effective and robust 2D photonic nanoplatform for the management of brain diseases.

[Epidemiology, diagnosis, treatment and control measures of trichinellosis in China: an overview]

Trichinellosis is a worldwide zoonotic parasitic disease, which may infect humans and a wide range of animals, including carnivores, herbivores and even birds. Humans get infections through ingestion of raw or semi-cooked meat or meat products containing live Trichinella larvae. Currently, this zoonosis is predominantly prevalent in southwestern, northeastern and central parts of China, which poses a great threat to human health and socioeconomic development. In addition, the emergent public health hazards caused by trichinellosis outbreaks greatly threaten human health and social stability. This review describes the current status, diagnosis, treatment and control measures of trichinellosis in China, so as to provide insights into trichinellosis control in the country.

[The epidemic, prophylaxis and treatment of cholera in Su-Wan Liberated Area in 1946]

Rugao and Haian belonging to First Branch of Su-Wan Liberated Area found fulminant cholera in 1946. The fulminant cholera spread throughout the Su-Wan Liberated Area in a short period of time. Thus, local mass and military led by CPC actively launched the Movement of Epidemic Prevention. They took some actions to clear up the circumstance, eliminate the pathogen, prevent the food contamination and cut off the route of transmission. Vaccination was carried out on a large scale. As a result of these measure, the fulminant cholera was efficiently controlled.

Anisotropic Signal Processing with Trigonal Selenium Nanosheet Synaptic Transistors

Hardware implementation of an artificial neural network requires neuromorphic devices to process information with low energy consumption and high heterogeneity. Here we demonstrate an electrolyte-gated synaptic transistor (EGT) based on a trigonal selenium (t-Se) nanosheet. Due to the intrinsic low conductivity of the Se channel, the t-Se synaptic transistor exhibits ultralow energy consumption, less than 0.1 pJ per spike. More importantly, the intrinsic low symmetry of t-Se offers a strong anisotropy along its c- and a-axis in electrical conductance with a ratio of up to 8.6. The multiterminal EGT device exhibits an anisotropic response of filtering behavior to the same external stimulus, which enables it to mimic the heterogeneous signal transmission process of the axon-multisynapse biostructure in the human brain. The proof-of-concept device in this work represents an important step to develop neuromorphic electronics for processing complex signals.

Highly reversible oxygen redox in layered compounds enabled by surface polyanions

Oxygen-anion redox in lithium-rich layered oxides can boost the capacity of lithium-ion battery cathodes. However, the over-oxidation of oxygen at highly charged states aggravates irreversible structure changes and deteriorates cycle performance. Here, we investigate the mechanism of surface degradation caused by oxygen oxidation and the kinetics of surface reconstruction. Considering Li₂MnO₃, we show through density functional theory calculations that a high energy orbital (lO_2p') at under-coordinated surface oxygen prefers over-oxidation over bulk oxygen, and that surface oxygen release is then kinetically favored during charging. We use a simple strategy of turning under-coordinated surface oxygen into polyanionic (SO₄)^2-, and show that these groups stabilize the surface of Li₂MnO₃ by depressing gas release and side reactions with the electrolyte. Experimental validation on Li_1.2Ni_0.2Mn_0.6O₂ shows that sulfur deposition enhances stability of the cathode with 99.0% capacity remaining (194 mA h g^-1) after 100 cycles at 1 C. Our work reveals a promising surface treatment to address the instability of highly charged layered cathode materials.

Electrophoretically Deposited p-Phenylene Diamine Reduced Graphene Oxide Ultrathin Film on LiNi0.5Mn1.5O4 Cathode to Improve the Cycle Performance

Spinel LiNi_0.5Mn_1.5O₄ (LNMO) has been considered as one of the most promising candidate cathode materials for power lithium-ion batteries. However, its cycle performance suffers from the increasing impedance of the LNMO-cathode/electrolyte interface (LNMO-CEI) layer caused by parasitic reactions on the electrode surface at high operating potentials. To address the capacity degradation upon cycling, we present a feasible way to realize electrode modification by electrophoretically deposited graphene ultrathin films on the exterior surface of the LNMO cathodes without decreasing the electrode density. A p-phenylene diamine reduced graphene oxide (pPD-rGO) film with an area density of 20 μg/cm² not only increases the capacity retention rate of the 1000th cycle at 4.2-5.2 V from 71.7 to 81.7% but also boosts the specific capacity from 110.6 to 122.4 mAh/g. X-ray photoelectron spectroscopy (XPS) spectra reveal that the pPD-rGO film with Lewis-base nature increases the content of LiF and reduces the number of RCF_x groups in the cycled electrode, indicating the consumption of high-potential-generated F radicals by the pPD-rGO film. Such consumption favors the formation of a robust interphase between the pPD-rGO film and the electrolyte, which could hinder the sustained production of F radicals, consequently stabilize the LNMO-CEI layer, and improve the cycle performance. An electrophoretically deposited Lewis-acid GO film of 20 μg/cm² reduces the specific capacity and fails to work as the pPD-rGO film. The chemical process for the formation of interphase on the GO film is similar to that on the bare LNMO electrode.

PEGylated Tantalum Nanoparticles: A Metallic Photoacoustic Contrast Agent for Multiwavelength Imaging of Tumors

Elemental tantalum is a well-known biomedical metal in clinics due to its extremely high biocompatibility, which is superior to that of other biomedical metallic materials. Hence, it is of significance to expand the scope of biomedical applications of tantalum. Herein, it is reported that tantalum nanoparticles (Ta NPs), upon surface modification with polyethylene glycol (PEG) molecules via a silane-coupling approach, are employed as a metallic photoacoustic (PA) contrast agent for multiwavelength imaging of tumors. By virtue of the broad optical absorbance from the visible to near-infrared region and high photothermal conversion efficiency (27.9%), PEGylated Ta NPs depict high multiwavelength contrast capability for enhancing PA imaging to satisfy the various demands (penetration depth, background noise, etc.) of clinical diagnosis as needed. Particularly, the PA intensity of the tumor region postinjection is greatly increased by 4.87, 7.47, and 6.87-fold than that of preinjection under 680, 808, and 970 nm laser irradiation, respectively. In addition, Ta NPs with negligible cytotoxicity are capable of eliminating undesirable reactive oxygen species, ensuring the safety for biomedical applications. This work introduces a silane-coupling strategy for the surface engineering of Ta NPs, and highlights the potential of Ta NPs as a biocompatible metallic contrast agent for multiwavelength photoacoustic image.

Two-Dimensional van der Waals Materials with Aligned In-Plane Polarization and Large Piezoelectric Effect for Self-Powered Piezoelectric Sensors

Piezoelectric two-dimensional (2D) van der Waals (vdWs) materials are highly desirable for applications in miniaturized and flexible/wearable devices. However, the reverse-polarization between adjacent layers in current 2D layered materials results in decreasing their in-plane piezoelectric coefficients with layer number, which limits their practical applications. Here, we report a class of 2D layered materials with an identical orientation of in-plane polarization. Their piezoelectric coefficients (e₂₂) increase with layer number, thereby allowing for the fabrication of flexible piezotronic devices with large piezoelectric responsivity and excellent mechanical durability. The piezoelectric outputs can reach up to 0.363 V for a 7-layer α-In₂Se₃ device, with a current responsivity of 598.1 pA for 1% strain, which is 1 order of magnitude higher than the values of the reported 2D piezoelectrics. The self-powered piezoelectric sensors made of these newly developed 2D layered materials have been successfully used for real-time health monitoring, proving their suitability for the fabrication of flexible piezotronic devices due to their large piezoelectric responses and excellent mechanical durability.

PEGylated rhenium nanoclusters: a degradable metal photothermal nanoagent for cancer therapy

A common issue of functional nanoagents for potential clinical translation is whether they are biodegradable or renal clearable. Previous studies have widely explored noble metal nanoparticles (Au and Pd) as the first generation of photothermal nanoagents for cancer therapy, but all of the reported noble metal nanoparticles are non-degradable. On the other hand, rhenium (Re), one of the noble and precious metals with a high atomic number (Z = 75), has been mainly utilized as a jet superalloy or chemical catalyst, but the biological characteristics and activity of Re nanoparticles have never been evaluated until now. To address these issues, here we report a simple and scalable liquid-reduction strategy to synthesize PEGylated Re nanoclusters, which exhibit intrinsically high photothermal conversion efficacy (33.0%) and high X-ray attenuation (21.2 HU mL mg-1), resulting in excellent photothermal ablation (100% tumor elimination) and higher CT enhancement (15.9 HU mL mg-1 for commercial iopromide in clinics). Impressively, biocompatible Re nanoclusters can degrade into renal clearable ReO4 - ions after exposure to H2O2, and thus achieve much higher renal clearance efficiency than conventional gold nanoparticles. This work reveals the potential of theranostic application of metallic Re nanoclusters with both biodegradation and renal clearance properties and provides insights into the design of degradable metallic platforms with high clinical prospects.

[Association between Lipoprotein(a) and the characteristics of left main coronary artery plaque in patients with stable angina pectoris]

Objective: To investigate the relationship between Lipoprotein (LP) (a) level and the characteristics of tissue components of left main coronary artery (LMCA) plaque. Methods: A total of 102 patients with stable angina pectoris who underwent percutaneous coronary intervention (PCI) in the People's Hospital of Henan Province from June 2010 to October 2016 were included. We performed intravascular ultrasound-virtual histology (IVUS-VH) to their LMCAs and evaluated the tissue characteristics, and the blood level of total cholesterol (TC), triacylglycerol (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), ApoB, ApoA1, LP(a) were measured. According to the value of their LP(a) level they were divided into 2 groups (high LP(a) group (>300 mg/L) (n=35) and low LP(a) group (≤300 mg/L) (n=67)), then the relationship between the above lipid values and the tissue characteristics of the LMCA plaque in the patients were evaluated. Results: Patients with a high LP(a) had a larger percentage of fibrolipid volume and a smaller percentage fibrous volume compared to patients with a normal LP(a) (25%±5% vs 13%±6%, P<0.01 and 50%±8% vs 61%±9%, P<0.01). Using multivariate linear regression analysis after adjustment for the above-mentioned confounding factors, LP(a) had a significantly positive correlation with fibrolipid volume percentage (r=0.645, β=0.29, P<0.01), and had a negative correlation with fibrous volume percentage (r=-0.467, β=-0.32,P<0.01), suggesting that the LP(a) was associated with the vulnerability of the LMCA plaque. Conclusion: For the patients with stable angina pectoris, the LP(a) has a significantly positive correlation with the percentage of fibrolipid volume and a negative correlation with the percentage of fibrous volume, suggesting that the LP(a) could predict the vulnerability of the LMCA plaque.

Yb- and Mn-Doped Lead-Free Double Perovskite Cs2AgBiX6 (X = Cl-, Br-) Nanocrystals

Lead-free double perovskite nanocrystals (NCs) have emerged as a new category of materials that hold the potential for overcoming the instability and toxicity issues of lead-based counterparts. Doping chemistry represents a unique avenue toward tuning and optimizing the intrinsic optical and electronic properties of semiconductor materials. In this study, we report the first example of doping Yb³⁺ ions into lead-free double perovskite Cs₂AgBiX₆ (X = Cl^-, Br^-) NCs via a hot injection method. The doping of Yb³⁺ endows the double perovskite NCs with a newly emerged near-infrared emission band (sensitized from the NC hosts) in addition to their intrinsic trap-related visible photoluminescence. By controlling the Yb-doping concentration, the dual emission profiles and photon relaxation dynamics of the double perovskite NCs can be systematically tuned. Furthermore, we have successfully inserted divalent Mn²⁺ ions in Cs₂AgBiCl₆ NCs and observed emergence of dopant emission. Our work illustrates an effective and facile route toward modifying and optimizing optical properties of double perovskite Cs₂AgBiX₆ (X = Cl^-, Br^-) NCs with an indirect bandgap nature, which can broaden a range of their potential applications in optoelectronic devices.

[Review of survey method for human time-activity pattern and its application in the exposure assessment of air pollutants]

Time activity pattern refers to the time and behavior of people at different locations. The knowledge of time-activity pattern is essential for air pollution exposure assessment when direct personal exposure monitoring can't not be conducted, because air pollutant concentrations may vary significantly by location and activity. This review is focused on the survey method for human time-activity pattern and its application in the exposure assessment of air pollutants. After comparing the diary-reported trips and Global Positioning System (GPS) recording method, we believed that diary-reported trips were more reliable in describing comprehensive and detail records of the behavior and environmental circumstances while GPS-recorded trend to maintain sound information of time, location and transportations. Meanwhile, according to different subjects, the air pollution exposure model could be divided for population and individuals. There were great difference between two types of model in many areas, including the required information about time, activity and microenvironment.

Ultrathin Co9S8 nanosheets vertically aligned on N,S/rGO for low voltage electrolytic water in alkaline media

Development of hydrogen as clean and efficient energy carrier for future is imperative. Water electrolysis, is considered as one of the most promising ways to realize large-scaled hydrogen production. However, a big obstacle of it is to reduce the electric energy consumption for water oxidation in the anode. Engineering of hierarchical architectures on the electrocatalysts could provide abundant active sites and thus boost the sluggish reaction kinetics of water oxidation. Herein, a sequential synthesis method is developed for in-situ growth of ultrathin Co₉S₈ nanosheets vertically aligned on N and S co-doped reduced graphene oxide (Co₉S₈/N,S-rGO) as novel and efficient electrocatalysts for water splitting. This architecture with vertically aligned ultrathin Co₉S₈ nanosheets on N,S/rGO is adopted to facilitate the electron transport and exposure of active sites. Benefiting from the synergetic catalysis between Co₉S₈ nanosheets and N,S/rGO, Co₉S₈/N,S-rGO presents remarkable electrocatalytic activity towards oxygen evolution with a low overpotential (266 mV to achieve current density of 10 mA cm⁻²), small Tafel slope of 75.5 mV dec⁻¹, and good durability in alkaline medium. This remarkable OER electrocatalytic activity is outperforms most of the known noble-metal-free electrocatalysts.