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Purpose: We aim to investigate the associations between lumbar paraspinal muscles and sagittal malalignment in patients undergoing lumbar three-column osteotomy. Methods: Patients undergoing three-column osteotomy between 2016 and 2021 with preoperative lumbar magnetic resonance imaging (MRI) and whole spine radiographs in the standing position were included. Muscle measurements were obtained using a validated custom software for segmentation and muscle evaluation to calculate the functional cross-sectional area (fCSA) and percent fat infiltration (FI) of the m. psoas major (PM) as well as the m. erector spinae (ES) and m. multifidus (MM). Spinopelvic measurements included pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L1–S1 lordosis (LL), T4–12 thoracic kyphosis (TK), spino-sacral angle (SSA), C7–S1 sagittal vertical axis (SVA), T1 pelvic angle (TPA) and PI–LL mismatch (PI − LL). Statistics were performed using multivariable linear regressions adjusted for age, sex, and body mass index (BMI). Results: A total of 77 patients (n= 40 female, median age 64 years, median BMI 27.9 kg/m2) were analyzed. After adjusting for age, sex and BMI, regression analyses demonstrated that a greater fCSA of the ES was significantly associated with greater SS and SSA. Moreover, our results showed a significant correlation between a greater FI of the ES and a greater kyphosis of TK. Conclusion: This study included a large patient cohort with sagittal alignment undergoing three-column osteotomy and is the first to demonstrate significant associations between the lumbar paraspinal muscle parameters and global sagittal alignment. Our findings emphasize the importance of the lumbar paraspinal muscles in sagittal malalignment.

In this study, (diamond + TiC) reinforced Ti6Al4V titanium matrix composites (DT-TMCs) were fabricated using the directed energy deposition (DED) technique to enhance multiple properties of the Ti6Al4V alloy. The phase composition, microstructure, microhardness, wear resistance, and thermal conductivity of the composites were investigated. The findings demonstrate that the DT-TMCs consist of diamond, in-situ formed TiC (including eutectic TiC and primary TiC), α-Ti and β-Ti. The formation of in-situ TiC is attributed to the partial dissolution of the diamond into the Ti6Al4V matrix during the DED process. The superior hardness of in-situ TiC, compared to that of Ti6Al4V alloy, plays a pivotal role in enhancing the overall hardness of the DT-TMCs. Owing to the high hardness and excellent thermal conductivity of diamond, the wear resistance and thermal conductivity of the DT-TMCs are superior to those of the unmodified Ti6Al4V alloy. With the diamond volume fraction increasing from 0% to 15%, the microhardness of the DT-TMCs raises from 333.99 HV0.2to 438.15 HV0.2, the wear rate decreases from 207.514 × 10−5 mm³·N−1·m−1to 2.256 × 10−5 mm³·N−1·m−1, and the thermal conductivity increases from 6.686 W·m−1·K−1to 13.613 W·m−1·K−1. Additionally, the in-situ TiC exhibits superior thermal conductivity compared to the Ti6Al4V alloy, which also contributes to the improved thermal conductivity of the DT-TMCs.

Spectrometer miniaturization is desired for handheld and portable applications, yet nearly no miniaturized spectrometer is reported operating within terahertz (THz) waveband. Computational strategy, which can acquire incident spectral information through encoding and decoding it using optical devices and reconstruction algorithms, respectively, is widely employed in spectrometer miniaturization as artificial intelligence emerges. We demonstrate a computational miniaturized THz spectrometer, where a plasmonic filter array tailors the spectral response of a blocked-impurity-band detector. Besides, an adaptive deep-learning algorithm is proposed for spectral reconstructions with curbing the negative impact from the optical property of the filter array. Our spectrometer achieves modest spectral resolution (2.3 cm−1) compared with visible and infrared miniaturized spectrometers, outstanding sensitivity (e.g., signal-to-noise ratio, 6.4E6: 1) superior to common benchtop THz spectrometers. The combination of THz optical devices and reconstruction algorithms provides a route toward THz spectrometer miniaturization, and further extends the applicable sphere of the THz spectroscopy technique.

Continuously increasing applications of robot technologies in unstructured environments put higher requirements on the robotic grippers’ performance, such as interaction capability, output force range, and controllability. However, currently, it is hard for either rigid or soft grippers to meet these requirements, as single soft or rigid structures alone are difficult to effectively overcome/alleviate their inherent defects, e.g., low compliance of rigid structures and low output force of soft structures. To deal with these difficulties, soft-rigid coupling grippers, or hybrid grippers are proposed. Technically, the soft-rigid coupling is a promising design that combines soft and rigid structures, in order to exploit their respective advantages, such as the strength of rigid structures and compliance of soft structures, in the same set of the gripper system. For the first time, herein, this paper systematically discusses the collaboration strategies of the existing hybrid robotic grippers, by classifying them as Rigid-active-soft-passive, Rigid-passive-soft-active, and Rigid-active-soft-active. At the same time, we introduce the integrated fabrication methods of hybrid grippers, through which the soft and rigid structures with great stiffness and property differences can be coupled together to construct a stable system. Also, possible performance improvements on soft-rigid coupling design for gripper systems are discussed.

Additive Manufacturing (AM), commonly referred to as 3D printing, has ushered in a transformative era in the realm of material fabrication. Due to its innovative layer-adhesive methodology, Binder Jetting (BJ) is anticipated to ascend as the method of choice for synthesizing a vast array of materials. Presently, the defects inherent in BJ technique have precipitated considerable detriments to the quality of resultant components. In response, this exhaustive review delineates the foundational principles of the BJ methodology firstly and endeavors to compile a comprehensive inventory of potential defects encountered during printing. Based on formation mechanism, for the first time, the defects associated with BJ are methodically categorized into quintuple classifications, including slicing defect, powder spreading defect, single-layer printing defect, multi-layer accumulation defect and depowdering defect. Particular heed is devoted to the anomalies precipitated by the binder's interaction with the powder bed, which fundamentally sets BJ apart from conventional AM methodologies. An amalgamation of numerical algorithms and physical paradigms is introduced in each corresponding classification to arm researchers with a profound comprehension of the mechanism behind these defects. Moreover, a variety of mitigation strategies for these corresponding defects, encompassing binder selection, procedural parameter refinement, post-processual interventions and the integration of hybridized techniques are further explored and summarized. Finally, it concludes by pinpointing existing lacunae within the domain of BJ research and projects their future directions. This manuscript, by offering a comprehensive review of defects, aspires to serve as a scholarly compendium for the impending scientific and technological advancements in BJ technology.

The use of a planar detection geometry in photoacoustic tomography results in the so- called limited-view problem due to the finite extent of the acoustic detection aperture. When images are reconstructed using one-step reconstruction algorithms, image quality is compromised by the presence of streaking artefacts, reduced contrast, image distortion and reduced signal-to-noise ratio. To mitigate this, model-based iterative reconstruction approaches based on least squares minimisation with and without total variation regularization were evaluated using in-silico, experimental phantom, ex vivo and in vivo data. Compared to one-step reconstruction methods, it has been shown that iterative methods provide better image quality in terms of enhanced signal-to-artefact ratio, signal-to-noise ratio, amplitude accuracy and spatial fidelity. For the total variation approaches, the impact of the regularization parameter on image feature scale and amplitude distribution was evaluated. In addition, the extent to which the use of Bregman iterations can compensate for the systematic amplitude bias introduced by total variation was studied. This investigation is expected to inform the practical application of model-based iterative image reconstruction approaches for improving photoacoustic image quality when using finite aperture planar detection geometries.

AbstractThe filling characteristic of rockfill is a non-ignorable engineering problem for high dams, and a reasonable control of compaction quality is the key to promoting the development of high dams. In this article, numerical and field tests were implemented to study the main problems affecting the compaction characteristics of large-size coarse-grained soil, namely determinations of the reasonable H0/dmax(the ratio of the compaction layer thickness to the maximum particle size) and the main influencing factors of minimum porosity. The macroscopic manifestations of the compaction characteristics were analyzed from the perspectives of energy, force chain, and particle breakage. The interaction between particles was explained by the ‘filling effect’ of fine particles, the ‘wedging effect’, and the ‘wall effect’ of coarse particles. It was found that the minimum porosity was not an inherent characteristic of rockfill, since the porosity and the corresponding degree of breakage were influenced by the compaction conditions. The value of H0/dmaxmeeting engineering practice was proposed, which can create favorable compaction conditions for obtaining the minimum porosity. Meantime, some suggestions were provided for obtaining the minimum porosity of large-size coarse-grained soil. The research results have an application reference value for the filling design and evaluation of high dams.

In this communication, a novel folded transmitarray antenna (FTA) based on the principle of the Risley-Prisms antenna is proposed, which can achieve circular polarized (CP) beam scanning in both azimuth and elevation planes with low scanning loss. The antenna consists of a CP patch feed source, a metal ground plate, and two rotatable circular polarization selective metasurfaces (CPSMs). The CPSM can fully reflect the CP incident waves in one mode (left-hand CP (LHCP) mode or right-hand CP (RHCP) mode) and transmit the CP incident waves in the other mode. By mechanically rotating two CPSMs above the feed source, the beam’s scan range covers 0°–52° in the elevation plane and 0°–360° in the azimuth plane. The measured maximum gain is 22.9 dBic at 16 GHz, with a total efficiency of 30.1%. Moreover, since the wave’s propagation path is folded, the overall profile of the proposed antenna is only $1.92 \lambda _{0}$ including the feed source. The proposed antenna has the advantages of low profile, compact structure, low loss, low cost, high gain, and easy fabrication. It has potential in applications that have limited space and weight, such as satellite communication and vehicle communication systems.

All-inorganic lead-free double perovskite offers a potential material platform for electronic or optoelectronic memory devices owing to its ionic migration-based electrical transport, high photosensitivity, low toxicity, and environmental stability. However, the commonly used polycrystalline perovskite films severely restrict device performance. Herein, we demonstrate a high-performance memristor based on single-crystal double perovskite Cs2AgBiBr6with an ultralow switching electric field of 6.67 × 104V m−1and a high current on/off ratio of 107. Remarkably, the resistive switching of Cs2AgBiBr6is found to be thickness-dependent, which evolves from volatile threshold to nonvolatile resistance switching with the crystal thickness from 100 to 800 nm. Elemental analysis reveals that the formation of conductive channels in Cs2AgBiBr6is associated with the migration of Br vacancies with low activation energy. In addition, the formed conductive channels can be annihilated by light illumination with controlled wavelength and intensity, which leads to the realization of optoelectronic memories with separate electrical-writing and optical-erasing processes. Our findings provide deep insights into the ionic migration in single-crystal perovskite and pave the way for its future application in electronic and optoelectronic memory devices.

Transcription factors are among the most attractive therapeutic targets but are considered largely ‘undruggable’ in part due to the intrinsically disordered nature of their activation domains. Here we show that the aromatic character of the activation domain of the androgen receptor, a therapeutic target for castration-resistant prostate cancer, is key for its activity as transcription factor, allowing it to translocate to the nucleus and partition into transcriptional condensates upon activation by androgens. On the basis of our understanding of the interactions stabilizing such condensates and of the structure that the domain adopts upon condensation, we optimized the structure of a small-molecule inhibitor previously identified by phenotypic screening. The optimized compounds had more affinity for their target, inhibited androgen-receptor-dependent transcriptional programs, and had an antitumorigenic effect in models of castration-resistant prostate cancer in cells and in vivo. These results suggest that it is possible to rationally optimize, and potentially even to design, small molecules that target the activation domains of oncogenic transcription factors.

AbstractAs one of the representatives of carbon-based semiconductors, diamond is called the “Mount Everest” of electronic materials. To maximize its properties and realize its industrial applications, the fabrication of wafer-scale high-quality diamonds is critical. To date, heteroepitaxy is considered as a promising method for the growth of diamond wafers with considerable development. In this review, fundamentals of diamond heteroepitaxy is firstly introduced from several perspectives including nucleation thermodynamics and kinetic, nucleation process at the atomic level, as well as the interplay between the epitaxial film and substrate. Second, the bias enhanced nucleation (BEN) method is reviewed, including BEN setup, BEN process window, nucleation phenomenology (mainly on Iridium), nucleation mechanism by ion bombardment, and large-scale nucleation realization. Third, the following textured growth process is presented, as well as grain boundary annihilation, and dislocation and stress reduction technologies. Fourth, the applications of diamonds in electronic devices are studied, showing its excellent performances in the future power and electronic devices. Finally, prospects in this field are proposed from several aspects.

Bandgap engineering of two-dimensional (2D) materials is essential for the design of photoelectrochemical (PEC) devices. Gallium(II) sulfide (GaS), a layered semiconductor material with a direct bandgap of approximately 3.05 eV, has recently gained extensive attention owing to its unique photoresponse property. However, its bandgap tunability relative to the number of layers has not been experimentally confirmed; thus, the effect of bandgap on the photoresponse has not been explored yet. Herein, few-layered GaS nanosheets (Ns) are prepared using a simple liquid-phase exfoliation (LPE) approach. After centrifuging at different speeds, GaS Ns with defined layers are obtained, which enable verification of the tunable bandgap from 2.02 to 3.15 eV. When applied as a PEC-type photodetector, the responsivity of the photodetector is 4.77 mA W−1and 33.7 μA W−1under bias voltages of 0.6 and 0 V, respectively. Theoretical models of the electronic structure suggest that a reduction in the number of layers, leading to a decrease of the effective mass at the valence band maximum (VBM), can enhance the carrier mobility of GaS Ns. This results in high photocurrents and indicates that 2D GaS Ns are ideal materials for future high-performance optoelectronic systems.

Broad output force and speed ranges are highly desired for actuators to endow soft robots with high performance, thereby increasing the range of tasks they can accomplish. However, limited by their low structural stiffness and single actuation method, most of the existed soft actuators are still difficult to achieve a broad force and speed range with a relatively compact body structure. Here, we propose a pneumatic and tendon actuation coupled soft actuator (PTCSA) with multiple actuation modes, mainly composing of a multi-joint thermoplastic polyurethanes (TPU)-made skeleton sealed in a film sleeve. The TPU skeleton with certain structural stiffness combined with soft joints allows PTCSA to output small force and respond rapidly under pneumatic actuation, as well as output high force and flexibly regulate response speed under tendon actuation, therefore achieving a broad force and speed range with a compact structure. The multiple modes constructed from the two actuation methods with different force and speed properties can cover diverse application scenarios. To demonstrate its performance, PTCSA is further used to construct a soft robotic arm (with a maximum lifting speed of 198°/s and can easily lift a load of 200 g), an inchworm-inspired wheel-footed soft robot (moves at a high speed of 2.13 cm/s when unload or pulls a load of 300 g forward), and a soft gripper (can grasp diverse objects, from 0.1 g potato chips to an 850 g roll of Sn-0.7Cu wire, from a high-speed moving tennis ball to an upright pen). This work indicates the potential of combining multiple complementary actuation methods to improve the force and speed range of soft actuators, and may provide inspiration for related research.

Evaluating the overall quality of care involves considering patient-reported outcomes. While in theory, postoperative functional improvement, as indicated by the Oswestry disability index (ODI), should result in postoperative patient satisfaction, the exact correlation has not been consistently evidenced in the literature. This study seeks to demonstrate the extent of ODI improvement required for achieving patient satisfaction two years post elective lumbar surgery.

The facet joints in the lumbar region, together with the intervertebral disc, regional ligaments and paraspinal muscles, provide stability to the disco-vertebral motion segments in different spinal position. The development of degenerative spondylolisthesis begins with dehydration of the intervertebral disc that leads to altered spinal load-bearing dynamics and an increased load on the facet joints. Failure of the biomechanical function of the facet joints leads to osteoarthritic changes in it and is implicated in spinal disorders such as degenerative spondylolisthesis. The presence of vacuum phenomenon in the facet joints is a sign of advanced arthropathy.

Degenerative lumbar spondylolisthesis (DLS) is a prevalent spinal condition that can result in significant disability. DLS is thought to result from a combination of disc and facet joint degeneration, as well as various biological, biomechanical, and behavioral factors. One hypothesis suggests that the progressive degeneration of segmental stabilizers, notably the paraspinal muscles, could contribute to a vicious cycle of increasing slippage.

Loss of mobility and musculoskeletal pain due to degenerative conditions is a major cause of reduced quality of life, especially in aging populations. Therefore, incidences of arthroplasty of hip and knee joint and spinal surgeries are rising. The simultaneous presence of spinal conditions and hip or knee osteoarthritis poses challenges in therapeutic decision-making and may lead to persistent complaints following operative treatments. While some studies have addressed the effects of preexisting spinal conditions and former spinal fusion surgery in arthroplasty outcomes, only few have investigated the effects of arthroplasty on lumbar spinal surgery outcomes.

Collagen is the primary structural protein of connective tissues. Disrupting the maintenance and turnover of connective tissues can lead to age-related changes and conditions, potentially influencing surgical outcomes negatively. The identification of reliable predictor biomarkers for revision spinal surgery is crucial. However, literature is scarce in exploring the role of imaging parameters. The intersection of skin ultrasound (US) parameters and their connection to connective tissues and advanced glycation end-products (AGEs), formed through the glycation of proteins like collagen contributing to age-related decline in tissue elastic properties, remains an area of ongoing investigation.

The recommended timing for returning to common activities after cervical spine surgery varies widely among physicians based on training background and personal opinion, without clear guidelines or consensus. The purpose of this study was to analyze spine surgeons’ responses about the recommended timing for returning to common activities after different cervical spine procedures.

Covalent organic frameworks (COFs) are promising cathode candidates with high structural stability. However, they contain redox inactive linkages and experience low redox potential. Herein, a full anti-aromatic microporous COF cathode material of TAQ-BQ is designed for aqueous zinc batteries. The anti-aromatic conjugation effectively lowers the energy level of the lowest unoccupied molecular orbital as revealed by theoretical calculations, which corresponds to an elevated redox potential. Besides, the structure contains imino active sites at the linkages, in addition to carbonyl at the active parts. As a result, the TAQ-BQ cathode exhibits a voltage of 1.53 V/1.54 V and between 1.35 and 0.45 V in zinc cells. It delivers 208 mAh g–1capacity at 0.1 A g–1and maintains 136 mAh g–1at 2 A g–1. Stable cycling is realized for 1000 cycles with 87% capacity retention. The co-de/insertion of Zn2+and protons is identified for energy storage. Our work reveals the promises of COF cathode materials for aqueous zinc batteries.

AbstractLarge size single crystal diamond (SCD) wafer has been strongly desired for various of advanced applications, while two major potential approaches, including mosaic growth and heteroepitaxy based on chemical vapor deposition method, are both stuck with respective technical barriers. This paper reveals and summarizes the essential commonality of the two schemes, and denominates the concept of “coessential-connection” (CC) growth. Such generalized concept involved the nature of the single crystal and polycrystalline diamond film deposition with similar mechanism and processes. The principle of CC growth process with detailed classification was elaborated, and influence of nucleus size and orientation mismatch was clarified, which is regarded as the core problem of large area SCD film growth viacoessential-connection process.

Heteroepitaxy is a better method of enlarging SCD wafer size than homoepitaxy. In this work, several aspects of the bias process for heteroepitaxial diamond nucleation are studied experimentally. First, with increasing bias time, the diamond-nucleation pathway is found to transform from “isolated-crystal nucleation” to “typical domain-nucleation” and back to “isolated-crystal nucleation.” An interdependent relationship between bias voltage and bias time is proposed: the higher the bias voltage, the shorter the bias time. Second, a correlation exists between the threshold bias voltage and reactor-chamber pressure: a higher reactor chamber pressure usually requires a higher threshold bias voltage to realize “typical domain nucleation.” Third, diamond bias-enhanced nucleation and growth is observed at a high CH4content, where the dynamic equilibrium between amorphous-carbon-layer deposition and atomic-hydrogen etching is broken. Finally, epitaxial nucleation is obtained on a substrate with ∅30 mm in a home-made MPCVD setup.

As a strong nucleophilic substance, hydrazine is widely used in the fields of agriculture, industry, and medicine. Hydrazine compounds usually exist as intermediates of some drugs. Many drugs, such as isoniazid and carbidopa, produce hydrazine metabolites. Hydrazine is a genotoxic substance, which can cause DNA lesions and cancer vialong-term exposure. Therefore, it is very important to monitor the level of hydrazine in the human body with high selectivity and sensitivity. Here, we synthesized a near-infrared (NIR) fluorescent probe Cy-HZ based on the hemicyanine skeleton to visualize the metabolism of the drug isoniazid in vivo. The ester group of the probe reacts with hydrazine to generate Cy-H, causing a change in fluorescence. Here, we studied its absorption and fluorescence spectra, the recognition response to hydrazine, the imaging of exogenous hydrazine in cells and the imaging in mice and further applied the probe to monitor the distribution and metabolism of isoniazid.

To release developers from time-consuming software development, many approaches have been proposed to generate source code automatically according to software requirements. With significant advances in deep learning and natural language processing, deep learning-based approaches are proposed to generate source code from natural language descriptions. The key insight is that given a large corpus of software requirements and their corresponding implementations, advanced deep learning techniques may learn how to translate software requirements into source code that fulfill such requirements. Although such approaches are reported to be highly accurate, they are evaluated on datasets that are rather small, lack of diversity, and significantly different from real-world software requirements. To this end, we build a large scale dataset that is composed of longer requirements as well as validated implementations. We evaluate the state-of-the-art approaches on this new dataset, and the results suggest that their performance on our dataset is significantly lower than that on existing datasets concerning the common metrics, i.e., BLEU. Evaluation results also suggest that the generated programs often contain syntactic and semantical errors, and none of them can pass even a single predefined test case. Further analysis reveals that the state-of-the-art approaches learn little from software requirements, and most of the successfully generated statements are popular statements in the training programs. Based on this finding, we propose a popularity-based approach that always generates the most popular statements in training programs regardless of the input (software requirements). Evaluation results suggest that none of the state-of-the-art approaches can outperform this simple statistics-based approach. As a conclusion, deep learning-based program generation requires significant improvement in the future, and our dataset may serve as a basis for future research in this direction.

The majority of adolescents and young adults (AYA) who use cannabis also use alcohol. Although cannabis use is increasing in the United States (US), it is not known whether the increase contributes to either increased co‐use of alcohol and cannabis (e.g., complementarity) or replacement of alcohol with cannabis (e.g., substitution). The current study estimated the prevalence of alcohol use by cannabis use status among US AYA ages 12 to 25 in 2018 and trends in alcohol use by cannabis use status from 2002 to 2018. Data were drawn from the 2002 to 2018 National Survey on Drug Use and Health public use data files. The analytic sample included AYA ages 12 to 25 (2018 sample, n= 26,924; total combined sample 2002 to 2018, n= 576,053). Linear and logistic regression models were used to estimate past‐month alcohol use, daily alcohol use, and average quantity of alcohol consumed among AYA with and without past‐month cannabis use from 2002 to 2018. In 2018, any alcohol use and daily alcohol use were significantly more common among AYA who used cannabis use than those who did not use cannabis. Overall, any alcohol use, daily alcohol use, and average drinks per day declined from 2002 to 2018 among AYA irrespective of recent cannabis use. However, the decline in any alcohol use, daily alcohol use, and average alcohol drinks per day was more rapid among AYA who used cannabis (daily and nondaily) than those who did not use cannabis. The rate of decline in average alcohol drinks per day was also higher among AYA with daily compared to nondaily cannabis use. Even with declines in alcohol use over time, drinking is much more common among AYA who report cannabis than those without recent cannabis use, which is consistent with complementarity. Yet, because the decline in alcohol use has been more rapid among AYA who use cannabis, there is also evidence of substitution. Thus, the current data on alcohol and cannabis use are consistent with both complementarity and substitution. However, these relationships may change as cannabis legalization expands over time. Alcohol use appears to be declining overall among US young persons, but the prevalence remains significantly higher among US young persons with current cannabis use. As such, a substantial proportion of young persons who use cannabis are vulnerable to the combined negative harms of cannabis and alcohol. The co‐use of alcohol and cannabis among young people should be considered by clinical and public health professionals working to reduce the harms of cannabis and alcohol use, especially as cannabis legalization expands.

The infusion of coronavirus disease 2019 (COVID-19) patients with mesenchymal stem cells (MSCs) potentially improves clinical symptoms, but the underlying mechanism remains unclear. We conducted a randomized, single-blind, placebo-controlled (29 patients/group) phase II clinical trial to validate previous findings and explore the potential mechanisms. Patients treated with umbilical cord-derived MSCs exhibited a shorter hospital stay (P= 0.0198) and less time required for symptoms remission (P= 0.0194) than those who received placebo. Based on chest images, both severe and critical patients treated with MSCs showed improvement by day 7 (P= 0.0099) and day 21 (P= 0.0084). MSC-treated patients had fewer adverse events. MSC infusion reduced the levels of C-reactive protein, proinflammatory cytokines, and neutrophil extracellular traps (NETs) and promoted the maintenance of SARS-CoV-2-specific antibodies. To explore how MSCs modulate the immune system, we employed single-cell RNA sequencing analysis on peripheral blood. Our analysis identified a novel subpopulation of VNN2+hematopoietic stem/progenitor-like (HSPC-like) cells expressing CSF3R and PTPRE that were mobilized following MSC infusion. Genes encoding chemotaxis factors — CX3CR1 and L-selectin — were upregulated in various immune cells. MSC treatment also regulated B cell subsets and increased the expression of costimulatory CD28 in T cells in vivo and in vitro. In addition, an in vivo mouse study confirmed that MSCs suppressed NET release and reduced venous thrombosis by upregulating kindlin-3 signaling. Together, our results underscore the role of MSCs in improving COVID-19 patient outcomes via maintenance of immune homeostasis.

High-performance tactile sensors are urgently demanded in various intensive interactive scenarios, e.g., texture detection, robotic interaction with fragile objects, and motion direction recognition, where dynamic conditions are involved with complex tangential forces or vibrations. Although many microstructured/porous sensors can perceive tangential forces, their isotropic structures that lack programmability lead them to be incapable of sensing the direction of forces and restrain their tunability for complex situations, e.g., a wide sensing range for large forces and high sensitivity for gentle forces. Here, by tuning the programmable microstructures (microcolumns and microfilms) of an elastomeric active layer, we propose a simple principle to flexibly tune the shear sensitivity of an anisotropic porous sensor and bring a 10-fold distinction of anisotropy with a wide range of shear sensitivity (from 0.07 to 0.7 N–1). The fabricated tactile sensors can be used in various robotic manipulations resiliently, for instance, morphology and topology identification of curved surfaces, delicate interactive manipulations, and recognizing the relative motion of two contacting objects. Our work introduces a simple and effective strategy for tailoring flexible shear-sensitive sensors for diverse dexterous robotic manipulations during complex interactions.

Two-dimensional (2D) organic–inorganic perovskites have shown interesting optical properties due to the natural quantum-well structures. The repetition of soft organic and hard inorganic intercalations also renders 2D perovskites rich phonon dynamics. Here, we investigated the coherent acoustic phonons in (PEA)2PbI4perovskite films by time-resolved Brillouin spectroscopy. The coherent acoustic phonons were launched indirectly in perovskite films by exciting Au nanoplates which were used as optoacoustic transducers. A longitudinal sound velocity ν= 1937 ± 31 m/s, and an elastic modulus E= 9.84 GPa along the cross-plane direction of perovskites were obtained from analysis of the Brillouin oscillation frequency. Following a bead-spring model, we calculated a spring constant k≈ 1.709 N m−1for PEA cations which is comparably small for perovskites. We also demonstrated that coherent acoustic phonons are sensitive to differentiate structural heterogeneity and monitor dynamic phase evolution in perovskite films. Domains of PbI2-rich and PbI2-poor phases were identified. Under light stimulus, PbI2-poor phases were gradually disappearing and PbI2-rich phases became crystallized. The observations of structural and elastic heterogeneity and dynamic phase evolution using coherent acoustic phonons provide a toolbox for submicroscale elastic characterization of perovskites.

We introduce a method for the (Z)-selective aminoallylation of a range of ketones to prepare allylic 1,2-amino tertiary alcohols with excellent diastereo- and enantioselectivity. Copper-catalyzed reductive couplings of 2-azatrienes with aryl/alkyl and dialkyl ketones proceed with Ph-BPE as the supporting ligand, generating anti-amino alcohols with >98% (Z)-selectivity under mild conditions. The utility of the products is highlighted through several transformations, including those that leverage the (Z)-allylic amine moiety for diastereoselective reactions of the alkene. Calculations illustrate Curtin–Hammett control in the product formation over other possible isomers and the origin of (Z)-selectivity.

Electrospun polymer-liquid crystal (PLC) fibers have potential applications such as wearable sensors and adaptive textiles because of their rapid response and high flexibility. However, existing PLC fibers only have a narrow responsive range and poor resistance to heat and chemicals. Herein, a new type of PLC fiber is prepared by using a coaxial electrospinning process. The core solution is 4′-pentyl-4-biphenylcarbonitrile (5CB), and the sheath solution is a mixture containing 13 wt % PVP and 10 wt % reactive mesogen (RM). After UV exposure of the fibers, 5CB in the core and RM diffusing from the core are cross-linked into an LC polymer. The fibers have a highly uniform morphology with an average diameter of 3.2 ± 0.5 μm, and mesogens inside the fibers align unidirectionally with the long axis of the fibers. The fibers show a broad phase-transition temperature range between 13.5 and 155.5 °C and have a response time of less than 10 s. The temperature range can also be controlled by adjusting components in the electrospun fibers and UV exposure time. The core-sheath fibers prepared in such a manner exhibit excellent heat and chemical resistance with reversible optical responses. Moreover, when the fibers are exposed to volatile organic compounds (VOCs) such as toluene, the fibers show a rapid optical response to toluene vapor within 25 s. This study demonstrates that the fibers are potentially useful for preparing flexible temperature and chemical sensors.

AbstractThe nitrogen vacancy (NV) color centers are a solid-state quantum system with the ability to maintain long coherence times at room temperatures. NV centers have potential applications in quantum detection, which necessitates their positioning at minimal distances from surfaces. However, the existing methods for fabricating NV centers are cumbersome, expensive, and difficult to control. This study investigates the etching mechanism of transition metals on diamond under plasma conditions and develops a method for producing shallow NV centers on the surface of high pressure and high temperature diamond. Our proposed method enables the production of shallow NV centers below the surface in the longitudinal direction, while simultaneously allowing precise control over the lateral distribution. Moreover, the operating costs associated with our technique are significantly lower than those of ion implantation and electron irradiation. This research contributes to the advancement of iron-etching diamond processing technology, and the proposed method facilitates the more portable preparation of shallow color centers in specific regions, enabling the realization of locally controllable and scalable coupled quantum systems.

Mid-infrared (MIR) detection systems are pursuing element detectors with a high operating temperature, fast response speed, and high sensitivity to satisfy the increasing performance requirements that conventional detectors are unlikely to achieve. In this paper, we report a lateral photovoltaic MIR detector (LPVMIRD) based on a two-dimensional electron gas (2DEG) at the polar zincblende/rocksalt interface of CdTe/PbTe (111) heterojunctions (HJs). The LPVMIRDs possess identical asymmetric structures and operate without external biased voltage. Following the working principle of the LPVMIRDs, an analytical model is established where device performances are predicted theoretically. The proposed model is also applicable to other HJ systems based on a 2DEG. Furthermore, the LPVMIRDs are developed experimentally, and through infrared photoresponse characterizations, their response is revealed to originate from the intrinsic transition of PbTe caused by the unique energy-band alignment of the HJs. At a wavelength of 3 µm, the highest detectivity of the fabricated LPVMIRDs reaches 1.5×10^10 Jones. Moreover, the infrared impulse responses demonstrate an extremely fast response speed. The impressive performance characteristics of the LPVMIRDs are promising for applications in uncooled MIR detection.

Indium selenide (InSe) has become a research hotspot because of its favorable carrier mobility and thickness-tunable band gap, showing great application potential in high-performance optoelectronic devices. The trend of miniaturization in optoelectronics has forced the feature sizes of the electronic components to shrink accordingly. Therefore, atomically thin InSe crystals may play an important role in future optoelectronics. Given the instability and ultralow photoluminescent (PL) emission of mechanically exfoliated ultrathin InSe, synthesis of highly stable mono- and few-layer InSe nanosheets with high PL efficiency has become crucial. Herein, ultrathin InSe nanosheets were prepared viathermal annealing of electrochemically intercalated products from bulk InSe. The size and yield of the as-prepared nanosheets were up to ∼160 μm and ∼70%, respectively, and ∼80% of the nanosheets were less than five layer. Impressively, the as-prepared nanosheets showed greatly enhanced stability and PL emission because of surface modification by carbon species. Efficient photoresponsivity of 2 A/W was achieved in the as-prepared nanosheet-based devices. These nanosheets were further assembled into large-area thin films with photoresponsivity of 16 A/W and an average Hall mobility of about 5 cm2V–1s–1. Finally, one-dimensional (1D) InSe nanoscrolls with a length up to 90 μm were constructed by solvent-assisted self-assembly of the exfoliated nanosheets.

Boron doped diamond (BDD) electrode is a promising electrochemical material for detecting dopamine level in the human's body. In this work, we developed a new doping source - graphite and solid boron oxide powders to synthesize BDD film with microwave plasma chemical vapor deposition, so as to avoid using toxic or corrosive dopants, such as boroethane and trimethylborate. The synthesized BDD film is pinhole free and with high doping density of 8.44 × 1020 cm−3 calculated from the Raman spectroscopy. Subsequently, Au nanospheres were decorated on the surface of BDD film to improve electrochemical performance of the BDD film. The Au nanoparticles modified BDD electrode demonstrates an excellent electrochemical response, a high sensitivity (in the range of 5 μM-1 mM), and a low detection limit (∼ 0.8 μM) for detecting dopamine. [ABSTRACT FROM AUTHOR]

Germanium selenide (GeSe) nanosheets are stable and inexpensive and considered to have a great potential for photovoltaic applications, however we have demonstrated that GeSe nanosheets are also promising for sensing technology, in this paper. By spin-coating the GeSe nanosheets on the surface of noble metal (Au), we have obtained a surface plasmon resonance (SPR) sensor with significantly enhanced sensitivity, and the performance of the sensor is closely related to the thickness of the GeSe film. By detecting different refractive index solutions, we have obtained the optimized sensitivity with 3581.2 nm/RIU (which is nearly 80% improvement compared to traditional SPR sensors) and figure of merit with 14.37 RIU−1. Moreover, the proposed SPR sensor was vastly superior in sensing Pb2+heavy metal ions after coating it with chitosan and GeSe composite. A maximum sensitivity of 30.38 nm/μg/l has been verified, which is nearly six times better than that of conventional SPR sensor. Our results demonstrated that GeSe nanosheets overlayer with modified SPR sensor has its great potential in heavy metal detection and chemical-specific molecular identification.

We fabricate germanium-based blocked-impurity-band (BIB) terahertz detectors with the same planar structure but different structural parameters. The photoresponse waveband range is about 40–130 μm. The best detectivity of these detectors reaches as high as 1.3 × 1013 Jones at 2.6 V and 4 K. The impact of the structural parameters, including the length of the absorbing layer and blocking layer (BL) on the performance of detectors, is investigated. It is concluded that there is an optimum BL length, enabling the fabricated BIB detectors to achieve the highest sensitivity. This work highlights the importance of the optimized structural parameters and their influence on the performance of the detectors.