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Abstract Fe-doped ZnO nanoneedles (NDs) were fabricated by an Ar+ ion sputtering technique operated at room temperature. The as-grown samples show both ferromagnetic and lasing properties. The saturated magnetization moment was measured from 0.307 to 0.659 emu cm−3 at the field of 10 kOe with various Fe concentrations. Intense ultraviolet random lasing emission was observed from Zn1 − x Fe x O NDs at room temperature. The X-ray photoelectron spectroscopy result reveals that the doped Fe atoms occupy the Zn sites and lead to a decrease in oxygen deficiency.

2D heterostructures have garnered significant interest in the scientific community owing to their exceptional carrier transport properties and tunable band alignment. The fabrication of these heterostructures on a wafer scale is crucial for advancing industrial applications but remains particularly challenging for metals with low sulfidation activity, such as Hf. Herein, the one-pot method is developed for fabricating wafer-scale HfSe 2 /WSe 2 interlayer heterostructures with vertically aligned van der Waals layers via interface-enhanced selenization and self-guided growth. By depositing a W layer (high sulfidation activity) over a Hf layer, followed by a one-pot selenization process, the chemical combination between Hf and Se atoms is enhanced through interfacial Se diffusion and confined lattice reaction. Moreover, the WSe 2 layers grow perpendicular to the substrate and further guide the crystallization of the bottom HfSe 2 layers. The resulting heterostructures, characterized by covalent bonds, demonstrate significant charge transfer, enhanced piezoelectricity, notable rectification effects, and Si-compatible transistor integration. This interface-enhanced selenization and self-guided growth pathway may provide valuable insights into the fabrication of covalently connected interlayer heterostructures involving metals with low sulfidation activity, as well as the development of high-density integrated circuits., (© 2025 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Hybrid heterostructures are pivotal in the advanced broadband detection technology. The emergence of 2D semimetals has expanded the range of materials in heterostructures beyond conventional narrow-gap materials for room-temperature broadband detection applications due to their extraordinary optical and electrical properties. This review outlines the cutting-edge and latest advancements in broadband photodetectors (PDs) engineered from heterostructures that synergistically combine 2D semimetals with several different dimensional materials. It begins with a fundamental investigation, offering an in-depth explanation of the essential material properties and a summary of synthesis methodologies. Then, the discussion advances to provide an analytical overview of the categorization, underlying photodetection mechanism, and figures-of-merit of these advanced PDs. Subsequently, the narrative shifts to a comprehensive analysis of heterogeneous integrated devices. The review further highlights the diverse optoelectronic applications of broadband PDs, spanning image sensing, optical communication, position-sensitive detection, integrated sensing and computing, spintronics, and computational spectroscopy are thoroughly highlighted. Finally, the review concludes by addressing the challenges and opportunities in advancing 2D semimetal materials for photodetection., (© 2025 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Hardware implementation of reconfigurable and nonvolatile photoresponsivity is essential for advancing in-sensor computing for machine vision applications. However, existing reconfigurable photoresponsivity essentially depends on the photovoltaic effect of p-n junctions, which photoelectric efficiency is constrained by Shockley-Queisser limit and hinders the achievement of high-performance nonvolatile photoresponsivity. Here, we employ bulk photovoltaic effect of rhombohedral (3R) stacked/interlayer sliding tungsten disulfide (WS 2 ) to surpass this limit and realize highly reconfigurable, nonvolatile photoresponsivity with a retinomorphic photovoltaic device. The device is composed of graphene/3R-WS 2 /graphene all van der Waals layered structure, demonstrating a wide range of nonvolatile reconfigurable photoresponsivity from positive to negative ( ± 0.92 A W -1 ) modulated by the polarization of 3R-WS 2 . Further, we integrate this system with a convolutional neural network to achieve high-accuracy (100%) color image recognition at σ = 0.3 noise level within six epochs. Our findings highlight the transformative potential of bulk photovoltaic effect-based devices for efficient machine vision systems., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Lithium-sulfur batteries (LSBs) afford great promises as the next-generation rechargeable batteries due to the high energy density and low cost of sulfur cathodes. Lean-electrolyte condition constitutes the prerequisite for high-energy LSBs, but the insulating sulfur particles hinder capacity utilization, especially at low temperatures. Here, the electrochemical generation of liquid sulfur droplets in the LSB system are studied and elucidate the polysulfide oxidation reaction (SOR) kinetics under different electrolyte/sulfur (E/S) ratios and low-temperature conditions. The real-time observations under in situ optical and Raman microscopies indicate that the formation of liquid sulfur during SOR is independent of the E/S ratio and can be preserved over a wide range of operating temperatures. Quantification of the polysulfide reactant concentrations and the amounts of the liquid sulfur product under different charging conditions reveal pseudo-zero-order kinetics and E/S ratio-dependent reaction constants for the SOR process. In addition, under extreme conditions of -20 °C and E/S ratio of 5 µL mg -1 , liquid sulfur can still be preserved by following the rapid SOR kinetics. These findings provide new insights into the liquid sulfur generation dynamics in Li─S chemistry, which enables a deeper understanding of the effects of the E/S ratio and working temperature on the oxidation kinetics in LSBs., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

We report the observation of an electric field in twisted-bilayer molybdenum disulfide (MoS 2 ) and elucidate its correlation with local polar domains using four-dimensional scanning transmission electron microscopy (4D-STEM) and first-principles calculations. We reveal the emergence of in-plane topological vortices within the periodic moiré patterns for both commensurate structures at small twist angles and the incommensurate quasicrystal structure that occurs at a 30° twist. The large-angle twist leads to mosaic chiral vortex patterns with tunable characteristics. A twisted quasicrystal bilayer, characterized by its 12-fold rotational symmetry, hosts complex vortex patterns and can be manipulated by picometer-scale interlayer displacement. Our findings highlight that twisting 2D bilayers is a versatile strategy for tailoring local electric polar vortices.

Intragrain impurities can impart detrimental effects on the efficiency and stability of perovskite solar cells, but they are indiscernible to conventional characterizations and thus remain unexplored. Using in situ scanning transmission electron microscopy, we reveal that intragrain impurity nano-clusters inherited from either the solution synthesis or post-synthesis storage can revert to perovskites upon irradiation stimuli, leading to the counterintuitive amendment of crystalline grains. In conjunction with computational modelling, we atomically resolve crystallographic transformation modes for the annihilation of intragrain impurity nano-clusters and probe their impacts on optoelectronic properties. Such critical fundamental findings are translated for the device advancement. Adopting a scanning laser stimulus proven to heal intragrain impurity nano-clusters, we simultaneously boost the efficiency and stability of formamidinium-cesium perovskite solar cells, by virtual of improved optoelectronic properties and relaxed intra-crystal strain, respectively. This device engineering, inspired and guided by atomic-scale in situ microscopic imaging, presents a new prototype for solar cell advancement., (© 2024. The Author(s).)

The quest for electronic devices that offer flexibility, wearability, durability and high performance has spotlighted two-dimensional (2D) van der Waals materials as potential next-generation semiconductors. Especially noteworthy is indium selenide, which has demonstrated surprising ultra-high plasticity. To deepen our understanding of this unusual plasticity in 2D van der Waals materials and to explore inorganic plastic semiconductors, we have conducted in-depth experimental and theoretical investigations on metal monochalcogenides (MX) and transition metal dichalcogenides (MX 2 ). We have discovered a general plastic deformation mode in MX, which is facilitated by the synergetic effect of phase transitions, interlayer gliding and micro-cracks. This is in contrast to crystals with strong atomic bonding, such as metals and ceramics, where plasticity is primarily driven by dislocations, twinning or grain boundaries. The enhancement of gliding barriers prevents macroscopic fractures through a pinning effect after changes in stacking order. The discovery of ultra-high plasticity and the phase transition mechanism in 2D MX materials holds significant potential for the design and development of high-performance inorganic plastic semiconductors., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Designing high-performance thermal catalysts with stable catalytic sites is an important challenge. Conventional wisdom holds that strong metal-support interactions can benefit the catalyst performance, but there is a knowledge gap in generalizing this effect across different metals. Here, we have successfully developed a generalizable strong metal-support interaction strategy guided by Tammann temperatures of materials, enabling functional oxide encapsulation of transition metal nanocatalysts. As an illustrative example, Co@BaAl 2 O 4 core@shell is synthesized and tracked in real-time through in-situ microscopy and spectroscopy, revealing an unconventional strong metal-support interaction encapsulation mechanism. Notably, Co@BaAl 2 O 4 exhibits exceptional activity relative to previously reported core@shell catalysts, displaying excellent long-term stability during high-temperature chemical reactions and overcoming the durability and reusability limitations of conventional supported catalysts. This pioneering design and widely applicable approach has been validated to guide the encapsulation of various transition metal nanoparticles for environmental tolerance functionalities, offering great potential to advance energy, catalysis, and environmental fields., (© 2024. The Author(s).)

Engineering piezo/ferroelectricity in two-dimensional materials holds significant implications for advancing the manufacture of state-of-the-art multifunctional materials. The inborn nonstoichiometric propensity of two-dimensional transition metal dichalcogenides provides a spiffy ready-available solution for breaking inversion centrosymmetry, thereby conducing to circumvent size effect challenges in conventional perovskite oxide ferroelectrics. Here, we show the extendable and ubiquitous piezo/ferroelectricity within nonstoichiometric two-dimensional transition metal dichalcogenides that are predominantly centrosymmetric during standard stoichiometric cases. The emerged piezo/ferroelectric traits are aroused from the sliding of van der Waals layers and displacement of interlayer metal atoms triggered by the Frankel defects of heterogeneous interlayer native metal atom intercalation. We demonstrate two-dimensional chromium selenides nanogenerator and iron tellurides ferroelectric multilevel memristors as two representative applications. This innovative approach to engineering piezo/ferroelectricity in ultrathin transition metal dichalcogenides may provide a potential avenue to consolidate piezo/ferroelectricity with featured two-dimensional materials to fabricate multifunctional materials and distinguished multiferroic., (© 2023. The Author(s).)

A recent study of liquid sulfur produced in an electrochemical cell has prompted further investigation into regulating Li-S oxidation chemistry. In this research, we examined the liquid-to-solid sulfur transition dynamics by visually observing the electrochemical generation of sulfur on a graphene-based substrate. We investigated the charging of polysulfides at various current densities and discovered a quantitative correlation between the size and number density of liquid sulfur droplets and the applied current. However, the areal capacities exhibited less sensitivity. This observation offers valuable insights for designing fast-charging sulfur cathodes. By incorporating liquid sulfur into Li-S batteries with a high sulfur loading of 4.2 mg cm -2 , the capacity retention can reach ∼100%, even when increasing the rate from 0.1 to 3 C. This study contributes to a better understanding of the kinetics involved in the liquid-solid sulfur growth in Li-S chemistry and presents viable strategies for optimizing fast-charging operations.

Next-generation mid-infrared (MIR) imaging chips demand free-cooling capability and high-level integration. The rising two-dimensional (2D) semimetals with excellent infrared (IR) photoresponses are compliant with these requirements. However, challenges remain in scalable growth and substrate-dependence for on-chip integration. Here, we demonstrate the inch-level 2D palladium ditelluride (PdTe 2 ) Dirac semimetal using a low-temperature self-stitched epitaxy (SSE) approach. The low formation energy between two precursors facilitates low-temperature multiple-point nucleation (∼300 °C), growing up, and merging, resulting in self-stitching of PdTe 2 domains into a continuous film, which is highly compatible with back-end-of-line (BEOL) technology. The uncooled on-chip PdTe 2 /Si Schottky junction-based photodetector exhibits an ultrabroadband photoresponse of up to 10.6 μm with a large specific detectivity. Furthermore, the highly integrated device array demonstrates high-resolution room-temperature imaging capability, and the device can serve as an optical data receiver for IR optical communication. This study paves the way toward low-temperature growth of 2D semimetals for uncooled MIR sensing.

Memory transistors based on two-dimensional (2D) ferroelectric semiconductors are intriguing for next-generation in-memory computing. To date, several 2D ferroelectric materials have been unveiled, among which 2D In 2 Se 3 is the most promising, as all the paraelectric (β), ferroelectric (α) and antiferroelectric (β') phases are found in 2D quintuple layers. However, the large-scale synthesis of 2D In 2 Se 3 films with the desired phase is still absent, and the stability for each phase remains obscure. Here we show the successful growth of centimetre-scale 2D β-In 2 Se 3 film by chemical vapour deposition including distinct centimetre-scale 2D β'-In 2 Se 3 film by an InSe precursor. We also demonstrate that as-grown 2D β'-In 2 Se 3 films on mica substrates can be delaminated or transferred onto flexible or uneven substrates, yielding α-In 2 Se 3 films through a complete phase transition. Thus, a full spectrum of paraelectric, ferroelectric and antiferroelectric 2D films can be readily obtained by means of the correlated polymorphism in 2D In 2 Se 3 , enabling 2D memory transistors with high electron mobility, and polarizable β'-α In 2 Se 3 heterophase junctions with improved non-volatile memory performance., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Patients with locally advanced pancreatic cancer (LAPC) are treated with chemotherapy. In selected cases, stereotactic body radiotherapy (SBRT) can be added to the regimen. We hypothesized that adding an adjuvant containing a heat-killed mycobacterium (IMM-101) to SBRT may lead to beneficial immuno-modulatory effects, thereby improving survival. This study aims to investigate the safety of adding IMM-101 to SBRT and to investigate the immuno-modulatory effects of the combination treatment in the peripheral blood of LAPC patients., Methods: LAPC patients were treated with SBRT (40 Gy) and six intradermal vaccinations of one milligram IMM-101. The primary endpoint was an observed toxicity rate of grade 4 or higher. Targeted gene-expression profiling and multicolor flow cytometry were performed for longitudinal immune-monitoring of the peripheral blood., Results: Twenty patients received study treatment. No treatment-related adverse events of grade 4 or higher occurred. SBRT/IMM-101 treatment induced a transient decrease in different lymphocyte subsets and an increase in CD14+CD16-CD11b+HLA-DR low myeloid-derived suppressor cells. Importantly, treatment significantly increased activated ICOS+, HLA-DR+ and Ki67+PD1+ T and NK cell frequencies. This was not accompanied by increased levels of most inhibitory markers, such as TIM-3 and LAG-3., Conclusions: Combination therapy with SBRT and a heat-killed mycobacterium vaccine was safe and had an immune-stimulatory effect.

Phase transitions in two-dimensional (2D) materials promise reversible modulation of material physical and chemical properties in a wide range of applications. 2D van der Waals layered In 2 Se 3 with bistable out-of-plane ferroelectric (FE) α phase and antiferroelectric (AFE) β' phase is particularly attractive for its electronic applications. However, reversible phase transition in 2D In 2 Se 3 remains challenging. Here, we introduce two factors, dimension (thickness) and strain, which can effectively modulate the phases of 2D In 2 Se 3 . We achieve reversible AFE and out-of-plane FE phase transition in 2D In 2 Se 3 by delicate strain control inside a transmission electron microscope. In addition, the polarizations in 2D FE In 2 Se 3 can also be manipulated in situ at the nanometer-sized contacts, rendering remarkable memristive behavior. Our in situ transmission electron microscopy (TEM) work paves a previously unidentified way for manipulating the correlated FE phases and highlights the great potentials of 2D ferroelectrics for nanoelectromechanical and memory device applications.

The electrochemical formation of liquid sulfur at room temperature on the basal plane of MoS 2 has attracted much attention due to the high areal capacity and rapid kinetics of lithium-liquid sulfur chemistry. However, the liquid sulfur is converted to the solid phase once it contacts the solid sulfur crystals generated from the edge of MoS 2 . Thus, stable liquid sulfur cannot be formed on the entire MoS 2 surface. Herein, we report entire liquid sulfur generation on hydrogen-annealed MoS 2 (H 2 -MoS 2 ), even under harsh conditions of large overpotentials and low working temperatures. The origins of the solely liquid sulfur formation are revealed to be the weakened interactions between H 2 -MoS 2 and sulfur molecules and the decreased electrical polarization on the edges of the H 2 -MoS 2 . Progressive nucleation and droplet-merging growth behaviors are observed during the sulfur formation on H 2 -MoS 2 , signifying high areal capacities by releasing active H 2 -MoS 2 surfaces. To demonstrate the universality of this strategy, other transition-metal dichalcogenides (TMDs) annealed in hydrogen also exhibit similar sulfur growth behaviors. Furthermore, the H 2 annealing treatment can induce sulfur vacancies on the basal plane and partial oxidation on the edge of TMDs, which facilitates liquid sulfur formation. Finally, liquid sulfur can be generated on H 2 -MoS 2 flakes at an ultralow temperature of -50 °C, which provides a possible development of low-temperature lithium-sulfur batteries. This work demonstrates the potential of a pure liquid sulfur-lithium electrochemical system using functionalized two-dimensional materials.

Phase patterning in polymorphic two-dimensional (2D) materials offers diverse properties that extend beyond what their pristine structures can achieve. If precisely controllable, phase transitions can bring exciting new applications for nanometer-scale devices and ultra-large-scale integrations. Here, the focused electron beam is capable of triggering the phase transition from the semiconducting T'' phase to metallic T' and T phases in 2D rhenium disulfide (ReS 2 ) and rhenium diselenide (ReSe 2 ) monolayers, rendering ultra-precise phase patterning technique even in sub-nanometer scale is found. Based on knock-on effects and strain analysis, the phase transition mechanism on the created atomic vacancies and the introduced substantial in-plane compressive strain in 2D layers are clarified. This in situ high-resolution scanning transmission electron microscopy (STEM) and in situ electrical characterizations agree well with the density functional theory (DFT) calculation results for the atomic structures, electronic properties, and phase transition mechanisms. Grain boundary engineering and electrical contact engineering in 2D are thus developed based on this patterning technique. The patterning method exhibits great potential in ultra-precise electron beam lithography as a scalable top-down manufacturing method for future atomic-scale devices., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

The data described was acquired as part of a clinical study with the aim to investigate the potential of tumor-reactive T-cell response as response to vaccination of pancreatic cancer patients with an allogenic tumor cell lysate vaccine (Lau et al., 2022). Proteomics analysis was carried out to identify tumor antigens that are shared between the allogeneic tumor cell lysate used for the vaccine and pancreatic ductal adenocarcinoma (PDAC) tissue samples. To this objective, cell lysates of the vaccine and of nine tissue samples were enzymatically digested and isotopically labeled with tandem mass tags (TMT) in a so-called six-plex manner (Thermo Fisher Scientific). Three pools were prepared by mixing the samples according to their TMT-labels. Subsequently, the three sample pools were fractionated into 24 fractions with high-pH reversed phase chromatography. These fractions were first analyzed on a nano-liquid chromatography (LC) system online coupled to a high-resolution Eclipse Orbitrap mass spectrometer (MS) equipped with a high-field asymmetric-waveform ion-mobility spectrometry (FAIMS) source using a data-dependent MS2 shotgun method. Overall, 126,618 unique peptide sequences, on basis of 768,638 peptide spectra matches and corresponding to 7,597 protein groups, were identified in the total sample set including 61 tumor antigens (Supplement Table S2 in Lau et al. 2022) that were prioritized by Cheever and co-workers as vaccine target antigens on basis of a series of objective criteria (Cheever et al., 2009). In the second phase of the experiment, this set of tumor antigens was targeted using a serial precursor selection (SPS) MS3 method. From this data, ion trap MS2 and Orbitrap MS3 fragment spectra were extracted for peptide identification (protein sequence database-dependent search) and relative quantification using the TMT labels, respectively. The dataset ultimately allowed the identification and quantification of 51 proteins and 163 related peptide precursors with the TMT labels (see Fig. 2B and Supplemental Fig. 8, Lau et al. 2022)., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Please declare any financial interests/personal relationships which may be considered as potential competing interests here: J.G.A: Stock or other Ownership: Amphera. Consulting or Advisory Role: Eli-Lilly, MSD Oncology, Bristol-Myers Squibb, Roche, AstraZeneca. Rest of the authors have no relationship to disclose in relation to the submitted work., (© 2022 Published by Elsevier Inc.)

Background: Pancreatic ductal adenocarcinoma (PDAC) is notorious for its poor prognosis even after curative resection. Responses to immunotherapy are rare and related to inadequate T-cell priming. We previously demonstrated the potency of allogeneic lysate-dendritic cell (DC) vaccination in a preclinical model. Here we translate this concept to patients., Methods: In this phase I study, patients with resected PDAC were included when they demonstrated no radiologic signs of recurrence after standard-of-care treatment. Allogeneic tumour lysate-loaded autologous monocyte-derived DCs were injected at weeks 0, 2, 4 and at months 3 and 6. Objectives are feasibility, safety and immunogenicity of allogeneic tumour-DCs. The presence of tumour antigens shared between the vaccine and patient tumours was investigated. Immunological analyses were performed on peripheral blood, skin and tumour., Results: Ten patients were included. DC production and administration were successful. All patients experienced a grade 1 injection-site and infusion-related reaction. Two patients experienced a grade 2 fever and 1 patient experienced a grade 3 dyspnoea. No vaccine-related serious adverse events were observed. Shared tumour antigens were found between the vaccine and patient tumours. All evaluated patients displayed a vaccine-induced response indicated by increased frequencies of Ki67+ and activated PD-1+ circulating T-cells. In addition, treatment-induced T-cell reactivity to autologous tumour of study patients was detected. Seven out of ten patients have not experienced disease recurrence or progression at a median follow-up of 25 months (15-32 months)., Conclusion: Allogeneic tumour lysate-DC treatment is feasible, safe and induces immune reactivity to PDAC expressed antigens., Competing Interests: Conflict of interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: J.G.A: Stock or other Ownership: Amphera. Consulting or Advisory Role: Eli-Lilly, MSD Oncology, Bristol-Myers Squibb, Roche, AstraZeneca. Rest of the authors have no relationship to disclose in relation to the submitted work., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: The prognosis of patients with advanced pancreatic ductal adenocarcinoma (PDAC) is dismal and conventional chemotherapy treatment delivers limited survival improvement. Immunotherapy may complement our current treatment strategies. We previously demonstrated that the combination of an allogeneic tumour-lysate dendritic cell (DC) vaccine with an anti-CD40 agonistic antibody resulted in robust antitumour responses with survival benefit in a murine PDAC model. In the Rotterdam PancrEAtic Cancer Vaccination-2 trial, we aim to translate our findings into patients. This study will determine the safety of DC/anti-CD40 agonistic antibody combination treatment, and treatment-induced tumour-specific immunological responses., Methods and Analysis: In this open-label, single-centre (Erasmus Univsersity Medical Center, Rotterdam, Netherlands), single-arm, phase I dose finding study, adult patients with metastatic pancreatic cancer with progressive disease after FOLFIRINOX chemotherapy will receive monocyte-derived DCs loaded with an allogeneic tumour lysate in conjunction with a CD40 agonistic antibody. This combination-immunotherapy regimen will be administered three times every 2 weeks, and booster treatments will be given after 3 and 6 months following the third injection. A minimum of 12 and a maximum of 18 patients will be included. The primary endpoint is safety and tolerability of the combination immunotherapy. To determine the maximum tolerated dose, DCs will be given at a fixed dosage and anti-CD40 agonist in a traditional 3+3 dose-escalation design. Secondary endpoints include radiographic response according to the RECIST (V.1.1) and iRECIST criteria, and the detection of antitumour specific immune responses., Ethics and Dissemination: The Central Committee on Research Involving Human Subjects (CCMO; NL76592.000.21) and the Medical Ethics Committee (METC; MEC-2021-0566) of the Erasmus M.C. University Medical Center Rotterdam approved the conduct of the trial. Written informed consent will be required for all participants. The results of the trial will be submitted for publication in a peer-reviewed scientific journal., Trial Registration Number: NL9723., Competing Interests: Competing interests: MPL: Grants to Institute: JnJ, Astellas, MSD, Sanofi. Consulting or Advisory Role: Roche, Bayer, Amgen, JnJ, Sanofi, Servier, Pfizer, Incyte, Novartis, Pan-Cancer T. J.G.J.V.A: Stock or other Ownership: Amphera. Consulting or Advisory Role: Eli-Lilly, MSD Oncology, Bristol-Myers Squibb, Roche, AstraZeneca. Rest of the authors have no relationship to disclose in relation to the submitted work., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Modern electronics demand transistors with extremely high performance and energy efficiency. Charge-based transistors with conventional semiconductors experience substantial heat dissipation because of carrier scattering. Here, we demonstrate low-loss topological phase change transistors (TPCTs) based on tellurium, a Weyl semiconductor. By modulating the energy separation between the Fermi level and the Weyl point of tellurium through electrostatic gate modulation, the device exhibits topological phase change between Weyl (Chern number ≠ 0) and conventional (Chern number = 0) semiconductors. In the Weyl ON state, the device has low-loss transport characteristics due to the global topology of gauge fields against external perturbations; the OFF state exhibits trivial charge transport in the conventional phase by moving the Fermi level into the bandgap. The TPCTs show a high ON/OFF ratio (10 8 ) at low operation voltage (≤2 volts) and high ON-state conductance (39 mS/μm). Our studies provide alternative strategies for realizing ultralow power electronics.

Two-dimensional materials with out-of-plane (OOP) ferroelectric and piezoelectric properties are highly desirable for the realization of ultrathin ferro- and piezoelectronic devices. We demonstrate unexpected OOP ferroelectricity and piezoelectricity in untwisted, commensurate, and epitaxial MoS 2 /WS 2 heterobilayers synthesized by scalable one-step chemical vapor deposition. We show d 33 piezoelectric constants of 1.95 to 2.09 picometers per volt that are larger than the natural OOP piezoelectric constant of monolayer In 2 Se 3 by a factor of ~6. We demonstrate the modulation of tunneling current by about three orders of magnitude in ferroelectric tunnel junction devices by changing the polarization state of MoS 2 /WS 2 heterobilayers. Our results are consistent with density functional theory, which shows that both symmetry breaking and interlayer sliding give rise to the unexpected properties without the need for invoking twist angles or moiré domains.

Work function strongly impacts the surficial charge distribution, especially for metal-support electrocatalysts when a built-in electric field (BEF) is constructed. Therefore, studying the correlation between work function and BEF is crucial for understanding the intrinsic reaction mechanism. Herein, we present a Pt@CoO x electrocatalyst with a large work function difference (ΔΦ) and strong BEF, which shows outstanding hydrogen evolution activity in a neutral medium with a 4.5-fold mass activity higher than 20 % Pt/C. Both experimental and theoretical results confirm the interfacial charge redistribution induced by the strong BEF, thus subtly optimizing hydrogen and hydroxide adsorption energy. This work not only provides fresh insights into the neutral hydrogen evolution mechanism but also proposes new design principles toward efficient electrocatalysts for hydrogen production in a neutral medium., (© 2022 Wiley-VCH GmbH.)

Deciphering the atomic and electronic structures of interfaces is key to developing state-of-the-art perovskite semiconductors. However, conventional characterization techniques have limited previous studies mainly to grain-boundary interfaces, whereas the intragrain-interface microstructures and their electronic properties have been much less revealed. Herein using scanning transmission electron microscopy, we resolved the atomic-scale structural information on three prototypical intragrain interfaces, unraveling intriguing features clearly different from those from previous observations based on standalone films or nanomaterial samples. These intragrain interfaces include composition boundaries formed by heterogeneous ion distribution, stacking faults resulted from wrongly stacked crystal planes, and symmetrical twinning boundaries. The atomic-scale imaging of these intragrain interfaces enables us to build unequivocal models for the ab initio calculation of electronic properties. Our results suggest that these structure interfaces are generally electronically benign, whereas their dynamic interaction with point defects can still evoke detrimental effects. This work paves the way toward a more complete fundamental understanding of the microscopic structure-property-performance relationship in metal halide perovskites.

Molecularly soft organic-inorganic hybrid perovskites are susceptible to dynamic instabilities of the lattice called octahedral tilt, which directly impacts their carrier transport and exciton-phonon coupling. Although the structural phase transitions associated with octahedral tilt has been extensively studied in 3D hybrid halide perovskites, its impact in hybrid 2D perovskites is not well understood. Here, we used scanning tunneling microscopy (STM) to directly visualize surface octahedral tilt in freshly exfoliated 2D Ruddlesden-Popper perovskites (RPPs) across the homologous series, whereby the steric hindrance imposed by long organic cations is unlocked by exfoliation. The experimentally determined octahedral tilts from n = 1 to n = 4 RPPs from STM images are found to agree very well with out-of-plane surface octahedral tilts predicted by density functional theory calculations. The surface-enhanced octahedral tilt is correlated to excitonic redshift observed in photoluminescence (PL), and it enhances inversion asymmetry normal to the direction of quantum well and promotes Rashba spin splitting for n > 1., (© 2022. The Author(s).)

Here, a new strategy that combines accessible active sites and multiphase synergy in a simple process is developed for constructing bifunctional electrocatalysts toward overall water splitting. By using metal-organic framework (MOF) nanosheets hydrothermally grown on pre-oxidized nickel foam (denoted by Co 2 (OH) 2 (BDC)/NiO/NF) as a precursor, two novel heterogeneous nanosheet arrays including a cobalt phosphide nanoparticle embedded carbon nanotube nanosheet array supported by phosphorized nickel foam (denoted by CoP-CNT/Ni 2 P/NF) and a cobalt phosphide nanorod decorated carbon nanosheet array supported by oxidized nickel foam (denoted by CoP-C/NiO/NF) are prepared. Both were confirmed to be highly efficient for hydrogen and oxygen evolution reactions. In particular, CoP-C/NiO/NF exhibits higher catalytic activity toward the hydrogen evolution reaction ( η 100 = -131 mV), promoted by the synergy of oxidized nickel foam. CoP-CNT/Ni 2 P/NF performs better in the oxygen evolution reaction ( η 50 = 301 mV), benefiting mainly from its improved electrochemically active surface area. The two catalysts match well in overall water splitting with satisfactory activity ( η 10 = 1.57 V) and stability when directly applied in a two-electrode cell. This method will bring new inspiration to maximize the electrocatalytic efficiency of MOF-derived catalysts for energy conversion applications in the future.

Lieb lattice, a two-dimensional edge-centered square lattice, has attracted considerable interest due to its exotic electronic and topological properties. Although various optical and photonic Lieb lattices have been experimentally demonstrated, it remains challenging for an electronic Lieb lattice to be realized in real material systems. Here, based on first-principles calculations and tight-binding modeling, a silver sulfide (Ag 2 S) monolayer is reported as a long-sought-after inorganic electronic Lieb lattice. This Lieb-lattice Ag 2 S is further found to be ultrasoft, which enables its electronic properties and topological states near the Fermi level to be finely tuned, as evidenced by the strain-induced topologically non-trivial edge states near the valence band edge. These results not only provide an ideal platform to further explore and harvest interesting quantum properties but also pave a way to pursue other inorganic electronic Lieb lattices in a broader material domain.

Two-dimensional materials provide opportunities for developing semiconductor applications at atomistic thickness to break the limits of silicon technology. Black phosphorus (BP), as a layered semiconductor with controllable bandgap and high carrier mobility, is one of the most promising candidates for transistor devices at atomistic thickness 1-4 . However, the lack of large-scale growth greatly hinders its development in devices. Here, we report the growth of ultrathin BP on the centimetre scale through pulsed laser deposition. The unique plasma-activated region induced by laser ablation provides highly desirable conditions for BP cluster formation and transportation 5,6 , facilitating growth. Furthermore, we fabricated large-scale field-effect transistor arrays on BP films, yielding appealing hole mobility of up to 213 and 617 cm 2  V -1  s -1 at 295 and 250 K, respectively. Our results pave the way for further developing BP-based wafer-scale devices with potential applications in the information industry., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

In humans receiving intestinal transplantation (ITx), long-term multilineage blood chimerism often develops. Donor T cell macrochimerism (≥4%) frequently occurs without graft-versus-host disease (GVHD) and is associated with reduced rejection. Here we demonstrate that patients with macrochimerism had high graft-versus-host (GvH) to host-versus-graft (HvG) T cell clonal ratios in their allografts. These GvH clones entered the circulation, where their peak levels were associated with declines in HvG clones early after transplant, suggesting that GvH reactions may contribute to chimerism and control HvG responses without causing GVHD. Consistently, donor-derived T cells, including GvH clones, and CD34+ hematopoietic stem and progenitor cells (HSPCs) were simultaneously detected in the recipients' BM more than 100 days after transplant. Individual GvH clones appeared in ileal mucosa or PBMCs before detection in recipient BM, consistent with an intestinal mucosal origin, where donor GvH-reactive T cells expanded early upon entry of recipient APCs into the graft. These results, combined with cytotoxic single-cell transcriptional profiles of donor T cells in recipient BM, suggest that tissue-resident GvH-reactive donor T cells migrated into the recipient circulation and BM, where they destroyed recipient hematopoietic cells through cytolytic effector functions and promoted engraftment of graft-derived HSPCs that maintain chimerism. These mechanisms suggest an approach to achieving intestinal allograft tolerance.

The formation, propagation, and structure of nanoscale cracks determine the failure mechanics of engineered materials. Herein, we have captured, with atomic resolution and in real time, unit cell-by-unit cell lattice-trapped cracking in two-dimensional (2D) rhenium disulfide (ReS_{2}) using in situ aberration corrected scanning transmission electron microscopy (STEM). Our real time observations of atomic configurations and corresponding strain fields in propagating cracks directly reveal the atomistic fracture mechanisms. The entirely brittle fracture with non-blunted crack tips as well as perfect healing of cracks have been observed. The mode I fracture toughness of 2D ReS_{2} is measured. Our experiments have bridged the linear elastic deformation zone and the ultimate nm-sized nonlinear deformation zone inside the crack tip. The dynamics of fracture has been explained by the atomic lattice trapping model. The direct visualization on the strain field in the ongoing crack tips and the gained insights of discrete bond breaking or healing in cracks will facilitate deeper insights into how atoms are able to withstand exceptionally large strains at the crack tips.

Mid-infrared (MIR) photodetection, covering diverse molecular vibrational regions and atmospheric transmission windows, is vital to civil and military purposes. Versatile use of MIR photodetectors is commonly dominated by HgCdTe alloys, InSb, and quantum superlattices, which are limited by strict operation demands, high-cost, and environmental toxicity. Despite the rapid advances of black phosphorus (BP)-based MIR photodetectors, these are subject to poor stability and large-area integration difficulty. Here, the van der Waals (vdW) epitaxial growth of a wafer-scale 2D platinum ditelluride (PtTe 2 ) layer is reported via a simple tellurium-vapor transformation approach. The 2D PtTe 2 layer possesses a unique mosaic-like crystal structure consisting of single-crystal domains with highly preferential [001] orientation along the normal direction, reducing the influence of interface defects and ensuring efficient out-of-plane carrier transportation. This characteristic, combined with the wide absorption of PtTe 2 and well-designed vertical device architecture, makes the PtTe 2 /Si Schottky junction photodetector capable of sensing ultra-broadband light of up to 10.6 µm with a high specific detectivity. Also, the photodetector exhibits an excellent room-temperature infrared-imaging capability. This approach provides a new design concept for high-performance, room-temperature MIR photodetection based on 2D layered materials., (© 2020 Wiley-VCH GmbH.)

Low-dimensional materials usually exhibit mechanical properties from those of their bulk counterparts. Here, we show in two-dimensional (2D) rhenium disulfide (ReS 2 ) that the fracture processes are dominated by a variety of previously unidentified phenomena, which are not present in bulk materials. Through direct transmission electron microscopy observations at the atomic scale, the structures close to the brittle crack tip zones are clearly revealed. Notably, the lattice reconstructions initiated at the postcrack edges can impose additional strain on the crack tips, modifying the fracture toughness of this material. Moreover, the monatomic thickness allows the restacking of postcrack edges in the shear strain-dominated cracks, which is potentially useful for the rational design of 2D stacking contacts in atomic width. Our studies provide critical insights into the atomistic processes of fracture and unveil the origin of the brittleness in the 2D materials., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

PD-1/PD-L1-checkpoint blockade therapy is generally thought to relieve tumor cell-mediated suppression in the tumor microenvironment but PD-L1 is also expressed on non-tumor macrophages and conventional dendritic cells (cDCs). Here we show in mouse tumor models that tumor-draining lymph nodes (TDLNs) are enriched for tumor-specific PD-1 + T cells which closely associate with PD-L1 + cDCs. TDLN-targeted PD-L1-blockade induces enhanced anti-tumor T cell immunity by seeding the tumor site with progenitor-exhausted T cells, resulting in improved tumor control. Moreover, we show that abundant PD-1/PD-L1-interactions in TDLNs of nonmetastatic melanoma patients, but not those in corresponding tumors, associate with early distant disease recurrence. These findings point at a critical role for PD-L1 expression in TDLNs in governing systemic anti-tumor immunity, identifying high-risk patient groups amendable to adjuvant PD-1/PD-L1-blockade therapy., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

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.

Background: Pancreatic ductal adenocarcinoma (PDAC) is notoriously resistant to treatment including checkpoint-blockade immunotherapy. We hypothesized that a bimodal treatment approach consisting of dendritic cell (DC) vaccination to prime tumor-specific T cells, and a strategy to reprogram the desmoplastic tumor microenvironment (TME) would be needed to break tolerance to these pancreatic cancers. As a proof-of-concept, we investigated the efficacy of combined DC vaccination with CD40-agonistic antibodies in a poorly immunogenic murine model of PDAC. Based on the rationale that mesothelioma and pancreatic cancer share a number of tumor associated antigens, the DCs were loaded with either pancreatic or mesothelioma tumor lysates., Methods: Immune-competent mice with subcutaneously or orthotopically growing KrasG12D/+;Trp53R172H/+;Pdx-1-Cre (KPC) PDAC tumors were vaccinated with syngeneic bone marrow-derived DCs loaded with either pancreatic cancer (KPC) or mesothelioma (AE17) lysate and consequently treated with FGK45 (CD40 agonist). Tumor progression was monitored and immune responses in TME and lymphoid organs were analyzed using multicolor flow cytometry and NanoString analyzes., Results: Mesothelioma-lysate loaded DCs generated cross-reactive tumor-antigen-specific T-cell responses to pancreatic cancer and induced delayed tumor outgrowth when provided as prophylactic vaccine. In established disease, combination with stimulating CD40 antibody was necessary to improve survival, while anti-CD40 alone was ineffective. Extensive analysis of the TME showed that anti-CD40 monotherapy did improve CD8 +T cell infiltration, but these essential effector cells displayed hallmarks of exhaustion, including PD-1, TIM-3 and NKG2A. Combination therapy induced a strong change in tumor transcriptome and mitigated the expression of inhibitory markers on CD8 +T cells., Conclusion: These results demonstrate the potency of DC therapy in combination with CD40-stimulation for the treatment of pancreatic cancer and provide directions for near future clinical trials., Competing Interests: Competing interests: JA: Stock or other Ownership: Amphera. Consulting or Advisory Role: Eli-Lilly, MSD Oncology, Bristol-Myers Squibb, Roche Speakers Bureau: AstraZeneca, Takeda, Boehringer Ingelheim., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

GeTe is an important narrow bandgap semiconductor material and has found application in the fields of phase change storage as well as spintronics devices. However, it has not been studied for application in the field of infrared photovoltaic detectors working at room temperature. Herein, GeTe nanofilms were grown by magnetron sputtering technique and characterized to investigate its physical, electrical, and optical properties. A high-performance infrared photovoltaic detector based on GeTe/Si heterojunction with the detectivity of 8 × 10 11 Jones at 850 nm light irradiation at room temperature was demonstrated.

Topological Dirac semimetals made of two-dimensional transition-metal dichalcogenides (TMDCs) have attracted enormous interest for use in electronic and optoelectronic devices because of their electron transport properties. As van der Waals materials with a strong interlayer interaction, these semimetals are expected to support layer-dependent plasmonic polaritons yet to be revealed experimentally. Here, we demonstrate the apparent retardation and attenuation of mid-infrared (MIR) plasmonic waves in type-II Dirac semimetal platinum tellurium (PtTe 2 ) nanoribbons and nanoflakes by near-field nanoimaging. The attenuated dispersion relations for the plasmonic modes in the PtTe 2 nanoribbons (15-25 nm thick) extracted from the near-field standing-wave patterns are applied for the fitting of PtTe 2 permittivity in the MIR regime, indicating that both free carriers and Dirac fermions are involved in MIR light-matter interaction in PtTe 2 . The annihilation of plasmonic modes in the ultrathin (<10 nm) PtTe 2 is observed and analyzed, which manifests no near-field resonant pattern due to the intrinsic layer-dependent optoelectronic properties of PtTe 2 . These results could pave a potential wave for MIR photodetection and modulation with TMDC semimetals.

Two-dimensional (2D) metallic transition metal dichalcogenides (TMDs) exhibit fascinating quantum effects, such as charge-density-wave (CDW) and weak antilocalization (WAL) effect. Herein, low temperature synthesis of 1T phase VSe 2 single crystals with thickness ranging from 3 to 41 nm by chemical vapor deposition (CVD) is reported. The VSe 2 shows a decreasing phase transition temperature of the CDW when the thickness is decreased. Moreover, low-temperature magnetotransport measurements demonstrate a linear positive and non-saturating magnetoresistance (MR) of 35% from a 35 nm thick VSe 2 at 15 T and 2 K due to CDW induce mobility fluctuations. Surprisingly, Kohler's rule analysis of the MR reveals the non-applicability of Kohler's rule for temperature above 50 K indicating that the MR behavior cannot be described in terms of semiclassical transport on a single Fermi surface with a single scattering time. Furthermore, WAL effect is observed in the 4.2 nm thick VSe 2 at low magnetic fields at 2 K, revealing the contribution of the quantum interference effect at the 2D limit. The phase coherence length [Formula: see text] and spin-orbit scattering length [Formula: see text] were determined to be 73 nm and 18 nm at 2 K, respectively. Our work opens new avenues to study the fundamental quantum phenomena in CVD-deposited TMDs.

Ultraviolet (UV) photodetector has attracted extensive interests due to its wide-ranging applications from defense technology to optical communications. The use of wide bandgap metal oxide semiconductor materials is of great interest in the development of UV photodetector due to their unique electronic and optical properties. In this work, deep UV photodetector based on NiO/β-Ga 2 O 3 heterojunction was developed and investigated. The β-Ga 2 O 3 layer was prepared by magnetron sputtering and exhibited selective orientation along the family of ([Formula: see text] 01) crystal plane after annealing. The photodetector demonstrated good performance with a high responsivity (R) of 27.43 AW -1 under a 245-nm illumination (27 μWcm -2 ) and the maximum detectivity (D*) of 3.14 × 10 12  cmHz 1/2  W -1 , which was attributed to the p-NiO/n-β-Ga 2 O 3 heterojunction.

Tantalum disulfide (TaS 2 ) two-dimensional film material has attracted wide attention due to its unique optical and electrical properties. In this work, we report the preparation of 1 T-TaS 2 quantum dots (1 T-TaS 2 QDs) by top-down method. Herein, we prepared the TaS 2 QDs having a monodisperse grain size of around 3 nm by an effective ultrasonic liquid phase exfoliation method. Optical studies using UV-Vis, PL, and PLE techniques on the as-prepared TaS 2 QDs exhibited ultraviolet absorption at 283 nm. Furthermore, we found that dimension reduction of TaS 2 has led to a modification of the band gap, namely a transition from indirect to direct band gap, which is explained using first-principle calculations. By using quinine as reference, the fluorescence quantum yield is 45.6%. Therefore, our results suggest TaS 2 QDs have unique and extraordinary optical properties. Moreover, the low-cost, facile method of producing high quality TaS 2 QDs in this work is ideal for mass production to ensure commercial viability of devices based on this material. TaS 2 quantum dots having a monodisperse grain size of around 3 nm have been prepared by an ultrasonic liquid phase exfoliation method, it has been found that the dimension reduction of TaS 2 has led to a transition from indirect to direct band gap that results in the unique and extraordinary optical properties (PL QY: 45.6%).

Discrete-scale invariance (DSI) is a phenomenon featuring intriguing log-periodicity that can be rarely observed in quantum systems. Here, we report the log-periodic quantum oscillations in the longitudinal magnetoresistivity ( ρ xx ) and the Hall traces ( ρ yx ) of HfTe 5 crystals, which reveal the DSI in the transport-coefficients matrix. The oscillations in ρ xx and ρ yx show the consistent log B -periodicity with a phase shift. The finding of the log B oscillations in the Hall resistance supports the physical mechanism as a general quantum effect originating from the resonant scattering. Combined with theoretical simulations, we further clarify the origin of the log-periodic oscillations and the DSI in the topological materials. This work evidences the universality of the DSI in the Dirac materials and provides indispensable information for a full understanding of this novel phenomenon., (© The Author(s) 2019. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.)

Ferroelectric domain walls exhibit a number of new functionalities that are not present in their host material. One of these functional characteristics is electrical conductivity that may lead to future device applications. Although progress has been made, the intrinsic conductivity of BiFeO 3 domain walls is still elusive. Here, the intrinsic conductivity of 71° and 109° domain walls is reported by probing the local conductance over a cross section of the BiFeO 3 /TbScO 3 (001) heterostructure. Through a combination of conductive atomic force microscopy, high-resolution electron energy loss spectroscopy, and phase-field simulations, it is found that the 71° domain wall has an inherently charged nature, while the 109° domain wall is close to neutral. Hence, the intrinsic conductivity of the 71° domain walls is an order of magnitude larger than that of the 109° domain walls associated with bound-charge-induced bandgap lowering. Furthermore, the interaction of adjacent 71° domain walls and domain wall curvature leads to a variation of the charge distribution inside the walls, and causes a discontinuity of potential in the [110] p direction, which results in an alternative conductivity of the neighboring 71° domain walls, and a low conductivity of the 71° domain walls when measurement is taken from the film top surface., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Group-10 transition metal dichalcogenides (TMDs) with distinct optical and tunable electrical properties have exhibited great potential for various optoelectronic applications. Herein, a self-powered photodetector is developed with broadband response ranging from deep ultraviolet to near-infrared by combining FA 1- x Cs x PbI 3 perovskite with PdSe 2 layer, a newly discovered TMDs material. Optoelectronic characterization reveals that the as-assembled PdSe 2 /perovskite Schottky junction is sensitive to light illumination ranging from 200 to 1550 nm, with the highest sensitivity centered at ≈800 nm. The device also shows a large on/off ratio of ≈10 4 , a high responsivity ( R ) of 313 mA W -1 , a decent specific detectivity ( D *) of ≈10 13 Jones, and a rapid response speed of 3.5/4 µs. These figures of merit are comparable with or much better than most of the previously reported perovskite detectors. In addition, the PdSe 2 /perovskite device exhibits obvious sensitivity to polarized light, with a polarization sensitivity of 6.04. Finally, the PdSe 2 /perovskite detector can readily record five "P," "O," "L," "Y," and "U" images sequentially produced by 808 nm. These results suggest that the present PdSe 2 /perovskite Schottky junction photodetectors may be useful for assembly of optoelectronic system applications in near future., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

ZrTe 2 is a candidate topological material from the layered two-dimensional transition-metal dichalcogenide family, and thus the material may show exotic electrical transport properties and may be promising for quantum device applications. In this work, we report the successful growth of layered ZrTe 2 thin film by pulsed-laser deposition and the experimental results of its magnetotransport properties. In the presence of a perpendicular magnetic field, the 60 nm thick ZrTe 2 film shows a large magnetoresistance of 3000% at 2 K and 9 T. A robust linear magnetoresistance is observed under an in-plane magnetic field, and negative magnetoresistance appears in the film when the magnetic field is parallel to the current direction. Furthermore, the Hall results reveal that the ZrTe 2 thin film has a high electron mobility of about 1.8 × 10 4 cm 2 V -1 s -1 at 2 K. These findings provide insights into further investigations and potential applications of this layered topological material system.

Low-dimensional semiconductors exhibit remarkable performances in many device applications because of their unique physical, electrical, and optical properties. In this paper, we report a novel and facile method to synthesize In 2 S 3 quantum dots (QDs) at atmospheric pressure and room temperature conditions. This involves the reaction of sodium sulfide with indium chloride and using sodium dodecyl sulfate (SDS) as a surfactant to produce In 2 S 3 QDs with excellent crystal quality. The properties of the as-prepared In 2 S 3 QDs were investigated and photodetectors based on the QDs were also fabricated to study the use of the material in optoelectronic applications. The results show that the detectivity of the device stabilizes at ~ 10 13 Jones at room temperature under 365 nm ultraviolet light irradiation at reverse bias voltage.

Human intestinal transplantation often results in long-term mixed chimerism of donor and recipient blood in transplant patients. We followed the phenotypes of chimeric peripheral blood cells in 21 patients receiving intestinal allografts over 5 years. Donor lymphocyte phenotypes suggested a contribution of hematopoietic stem and progenitor cells (HSPCs) from the graft. Surprisingly, we detected donor-derived HSPCs in intestinal mucosa, Peyer's patches, mesenteric lymph nodes, and liver. Human gut HSPCs are phenotypically similar to bone marrow HSPCs and have multilineage differentiation potential in vitro and in vivo. Analysis of circulating post-transplant donor T cells suggests that they undergo selection in recipient lymphoid organs to acquire immune tolerance. Our longitudinal study of human HSPCs carried in intestinal allografts demonstrates their turnover kinetics and gradual replacement of donor-derived HSPCs from a circulating pool. Thus, we have demonstrated the existence of functioning HSPCs in human intestines with implications for promoting tolerance in transplant recipients., (Copyright © 2018 Elsevier Inc. All rights reserved.)