Giant nonreciprocal second-harmonic generation from antiferromagnetic bilayer CrI3.

Layered antiferromagnetism is the spatial arrangement of ferromagnetic layers with antiferromagnetic interlayer coupling. The van der Waals magnet chromium triiodide (CrI3) has been shown to be a layered antiferromagnetic insulator in its few-layer form1, opening up opportunities for various functionalities2-7 in electronic and optical devices. Here we report an emergent nonreciprocal second-order nonlinear optical effect in bilayer CrI3. The observed second-harmonic generation (SHG; a nonlinear optical process that converts two photons of the same frequency into one photon of twice the fundamental frequency) is several orders of magnitude larger than known magnetization-induced SHG8-11 and comparable to the SHG of the best (in terms of nonlinear susceptibility) two-dimensional nonlinear optical materials studied so far12,13 (for example, molybdenum disulfide). We show that although the parent lattice of bilayer CrI3 is centrosymmetric, and thus does not contribute to the SHG signal, the observed giant nonreciprocal SHG originates only from the layered antiferromagnetic order, which breaks both the spatial-inversion symmetry and the time-reversal symmetry. Furthermore, polarization-resolved measurements reveal underlying C2h crystallographic symmetry-and thus monoclinic stacking order-in bilayer CrI3, providing key structural information for the microscopic origin of layered antiferromagnetism14-18. Our results indicate that SHG is a highly sensitive probe of subtle magnetic orders and open up possibilities for the use of two-dimensional magnets in nonlinear and nonreciprocal optical devices.

Supramolecular cage-mediated cargo transport.

A steady stream of material transport based on carriers and channels in living systems plays an extremely important role in normal life activities. Inspired by nature, researchers have extensively applied supramolecular cages in cargo transport because of their unique three-dimensional structures and excellent physicochemical properties. In this review, we will focus on the development of supramolecular cages as carriers and channels for cargo transport in abiotic and biological systems over the past fifteen years. In addition, we will discuss future challenges and potential applications of supramolecular cages in substance transport.

Fluorogenic Peptide Sensor Array Derived from Angiotensin-Converting Enzyme 2 Classifies Severe Acute Respiratory Syndrome Coronavirus 2 Variants of Concern.

The devastating COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made society acutely aware of the urgency in developing effective techniques to timely monitor the outbreak of previously unknown viral species as well as their mutants, which could be even more lethal and/or contagious. Here, we report a fluorogenic sensor array consisting of peptides truncated from the binding domain of human angiotensin-converting enzyme 2 (hACE2) for SARS-CoV-2. A set of five fluorescently tagged peptides were used to construct the senor array in the presence of different low-dimensional quenching materials. When orthogonally incubated with the wild-type SARS-CoV-2 and its variants of concern (VOCs), the fluorescence of each peptide probe was specifically recovered, and the different recovery rates provide a "fingerprint" characteristic of each viral strain. This, in turn, allows them to be differentiated from each other using principal component analysis. Interestingly, the classification result from our sensor array agrees well with the evolutionary relationship similarity of the VOCs. This study offers insight into the development of effective sensing tools for highly contagious viruses and their mutants based on rationally truncating peptide ligands from human receptors.

Rhizosphere microbial community construction during the latitudinal spread of the invader Chromolaena odorata.

The colonization of alien plants in new habitats is typically facilitated by microorganisms present in the soil environment. However, the diversity and structure of the archaeal, bacterial, and fungal communities in the latitudinal spread of alien plants remain unclear. In this study, the rhizosphere and bulk soil of Chromolaena odorata were collected from five latitudes in Pu' er city, Yunnan Province, followed by amplicon sequencing of the soil archaeal, bacterial, and fungal communities. Alpha and beta diversity results revealed that the richness indices and the structures of the archaeal, bacterial, and fungal communities significantly differed along the latitudinal gradient. Additionally, significant differences were observed in the bacterial Shannon index, as well as in the structures of the bacterial and fungal communities between the rhizosphere and bulk soils. Due to the small spatial scale, trends of latitudinal variation in the archaeal, bacterial, and fungal communities were not pronounced. Total potassium, total phosphorus, available nitrogen, available potassium and total nitrogen were the important driving factors affecting the soil microbial community structure. Compared with those in bulk soil, co-occurrence networks in rhizosphere microbial networks presented lower complexity but greater modularity and positive connections. Among the main functional fungi, arbuscular mycorrhizae and soil saprotrophs were more abundant in the bulk soil. The significant differences in the soil microbes between rhizosphere and bulk soils further underscore the impact of C. odorata invasion on soil environments. The significant differences in the soil microbiota along latitudinal gradients, along with specific driving factors, demonstrate distinct nutrient preferences among archaea, bacteria, and fungi and indicate complex microbial responses to soil nutrient elements following the invasion of C. odorata.

Contrast-enhanced phase-resolved second harmonic generation microscopy.

The characterization of inverted structures (crystallographic, ferroelectric, or magnetic domains) is crucial in the development and application of novel multi-state devices. However, determining these inverted structures needs a sensitive probe capable of revealing their phase correlation. Here a contrast-enhanced phase-resolved second harmonic generation (SHG) microscopy is presented, which utilizes a phase-tunable Soleil-Babinet compensator and the interference between the SHG fields from the inverted structures and a homogeneous reference. By this means, such inverted structures are correlated through the π-phase difference of SHG, and the phase difference is ultimately converted into the intensity contrast. As a demonstration, we have applied this microscopy in two scenarios to determine the inverted crystallographic domains in two-dimensional van der Waals material MoS2. Our method is particularly suitable for applying in vacuum and cryogenic environments while providing optical diffraction-limited resolution and arbitrarily adjustable contrast. Without loss of generality, this contrast-enhanced phase-resolved SHG microscopy can also be used to resolve other non-centrosymmetric inverted structures, e.g. ferroelectric, magnetic, or multiferroic phases.

Phylogenomic and ecological analyses reveal the spatiotemporal evolution of global pines.

How coniferous forests evolved in the Northern Hemisphere remains largely unknown. Unlike most groups of organisms that generally follow a latitudinal diversity gradient, most conifer species in the Northern Hemisphere are distributed in mountainous areas at middle latitudes. It is of great interest to know whether the midlatitude region has been an evolutionary cradle or museum for conifers and how evolutionary and ecological factors have driven their spatiotemporal evolution. Here, we investigated the macroevolution of Pinus, the largest conifer genus and characteristic of northern temperate coniferous forests, based on nearly complete species sampling. Using 1,662 genes from transcriptome sequences, we reconstructed a robust species phylogeny and reestimated divergence times of global pines. We found that ∼90% of extant pine species originated in the Miocene in sharp contrast to the ancient origin of Pinus, indicating a Neogene rediversification. Surprisingly, species at middle latitudes are much older than those at other latitudes. This finding, coupled with net diversification rate analysis, indicates that the midlatitude region has provided an evolutionary museum for global pines. Analyses of 31 environmental variables, together with a comparison of evolutionary rates of niche and phenotypic traits with a net diversification rate, found that topography played a primary role in pine diversification, and the aridity index was decisive for the niche rate shift. Moreover, fire has forced diversification and adaptive evolution of Pinus Our study highlights the importance of integrating phylogenomic and ecological approaches to address evolution of biological groups at the global scale.

Lighting Up Bispyrene-Functionalized Chiral Molecular Muscles with Switchable Circularly Polarized Excimer Emissions.

Aiming at the further extension of the application scope of traditional molecular muscles, a novel bispyrene-functionalized chiral molecular [c2]daisy chain was designed and synthesized. Taking advantage of the unique dimeric interlocked structure of molecular [c2]daisy chain, the resultant chiral molecular muscle emits strong circularly polarized luminescence (CPL) attributed to the pyrene excimer with a high dissymmetry factor (glum) value of 0.010. More importantly, along with the solvent- or anion- induced motions of the chiral molecular muscle, the precise regulation of the pyrene stacking within its skeleton results in the switching towards either "inversed" state with sign inversion and larger glum values or "down" state with maintained handedness and smaller glum values, making it a novel multistate CPL switch. As the first example of chiral molecular muscle-based CPL switch, this proof-of-concept study not only successfully widens the application scopes of molecular muscles, but also provides a promising platform for the construction of novel smart chiral luminescent materials for practical applications.

Orthogonal sp3-Ge/B Bimetallic Modules: Enantioselective Construction and Enantiospecific Cross-Coupling.

In this study, a series of enantioenriched sp3-Ge/B bimetallic modules were successfully synthesized via an enantioselective copper-catalyzed hydroboration of carbagermatrane (Ge)-containing alkenes. Orthogonal cross-coupling selectivity under different Pd-catalyzed conditions was achieved in an enantiospecific manner. Notably, the chiral secondary Ge exhibited a remarkable transmetallation ability prior to primary or secondary Bpin. The effectiveness of this Ge/B bimetallic strategy was further demonstrated through the development of new functional small molecules with Aggregation-Induced Emission (AIE) and Circularly Polarized Luminescence (CPL) performance. This represents the first successful example of synthesis of enantioenriched alkylgermanium reagents that permit enantiospecific cross-coupling reactions.

Dual Stimuli-Responsive [2]Rotaxanes with Tunable Vibration-Induced Emission and Switchable Circularly Polarized Luminescence.

Aiming at the construction of novel stimuli-responsive fluorescent system with precisely tunable emissions, the typical 9,14-diphenyl-9,14-dihydrodibenzo[a, c]phenazine (DPAC) luminogen with attractive vibration-induced emission (VIE) behavior has been introduced into [2]rotaxane as a stopper. Taking advantage of their unique dual stimuli-responsiveness towards solvent and anion, the resultant [2]rotaxanes reveal both tunable VIE and switchable circularly polarized luminescence (CPL). Attributed to the formation of mechanical bonds, DPAC-functionalized [2]rotaxanes display interesting VIE behaviors including white-light emission upon the addition of viscous solvent, as evaluated in detail by femtosecond transient absorption (TA) spectra. In addition, ascribed to the regulation of chirality information transmission through anion-induced motions of chiral wheel, the resolved chiral [2]rotaxanes reveal unique switchable CPL upon the addition of anion, leading to significant increase in the dissymmetry factors (glum ) values with excellent reversibility. Interestingly, upon doping the chiral [2]rotaxanes in stretchable polymer, the blend films reveal remarkable emission change from white light to light blue with significant 6.5-fold increase in glum values up to -0.035 under external tensile stresses. This work provides not only a new design strategy for developing molecular systems with fluorescent tunability but also a novel platform for the construction of smart chiral luminescent materials for practical use.

Expanded Azahelicenes with Large Dissymmetry Factors.

Expanded azahelicenes, as heteroanalogues of helically chiral helicenes, hold significant potential for chiroptical materials. Nevertheless, their investigation and research have remained largely unexplored. Herein, we present the facile synthesis of a series of expanded azahelicenes NHn (n=1-5) consisting of 11, 19, 27, 35, and 43 fused rings, mainly by Suzuki coupling followed by Bi(OTf)3-mediated cyclization of vinyl ethers. The structures of NH2, NH3 and NH4 were confirmed through X-ray crystallography analysis, and their (P)- and (M)- enantiomers were also isolated with chiral high performance liquid chromatography. The enantiomers exhibit large absorption (abs) and luminescence (lum) dissymmetry factors, with |gabs|max=0.044; |glum|max=0.003 for NH2, |gabs|max=0.048; |glum|=0.014 for NH3, and |gabs|max=0.043; |glum|max=0.021 for NH4, which are superior to their respective all-carbon analogues.

Efficient Self-Sorting Behaviours of Metallacages with Subtle Structural Differences.

Investigating the self-sorting behaviour of assemblies with subtle structural differences is a captivating yet challenging endeavour. Herein, we elucidate the unusual self-sorting behaviour of metallacages with subtle structural differences in batch reactors and microdroplets. Narcissistic self-sorting of metallacages has been observed for two ligands with identical sizes, shapes, and symmetries, with only minor differences in the substituted groups. In particular, the self-sorting process in microdroplets occurs within 1 min at room temperature, in stark contrast to batch reactors, which require equilibration for 30 min. To reveal the mechanism of self-sorting and the role of microdroplets, we conducted a series of experiments and theoretical calculations, including competitive self-assembly, cage-to-cage transformation, control experiments involving model metallacages with larger cavities, noncovalent interaction analysis, and root mean square deviation (RMSD) analysis. This research demonstrates an unusual case of self-sorting of very similar assemblies and provides a new strategy for facilitating the self-sorting efficiency of supramolecular systems.

Catalytic Enantioselective Synthesis of Planar Chiral Pillar[5]arenes via Asymmetric Sonogashira Coupling.

As a novel type of macrocycles with attractive planar chirality, pillar[5]arenes have gained increasing research interest over the past decades, enabling their widespread applications in diverse fields such as porous materials, molecular machines, and chiral luminescence materials. However, the catalytic methodology towards the enantioselective synthesis of planar chiral pillar[5]arenes remains elusive. Here we report a novel method for the enantioselective synthesis of planar chiral pillar[5]arenes via asymmetric Sonogashira coupling, giving access to a wide range of highly functionalized planar chiral pillar[5]arenes, including both homo- and hetero-rimmed ones, with excellent enantioselectivities. Attractively, the resultant planar chiral pillar[5]arenes show great potential for widespread use in many areas such as chiral luminescent materials. This work not only enables the successful synthesis of planar chiral pillar[5]arenes with abundant structural and functional diversity as key building blocks for practical applications but also enriches the asymmetric cross-coupling methodologies in organic synthetic chemistry.

Photoresponsive Rotaxane-Branched Dendrimers: From Nanoscale Dimension Modulation to Macroscopic Soft Actuators.

Aiming at the construction of novel soft actuators through the amplified motions of molecular machines at the nanoscale, the design and synthesis of a new family of photoresponsive rotaxane-branched dendrimers through an efficient controllable divergent approach was successfully realized for the first time. In the third-generation rotaxane-branched dendrimers, up to 21 azobenzene-based rotaxane units located at each branch, thus making them the first successful synthesis of light-control integrated artificial molecular machines. Notably, upon alternative irradiation with UV and visible light, photoisomerization of the azobenzene stoppers leads to the collective and amplified motions of the precisely arranged rotaxane units, resulting in controllable and reversible dimension modulation of the integrating photoresponsive rotaxane-branched dendrimers in solution. Moreover, novel macroscopic soft actuators were further constructed based on these photoresponsive rotaxane-branched dendrimers, which revealed fast shape transformation behaviors with an actuating speed up to 21.2 ± 0.2° s-1 upon ultraviolet irradiation. More importantly, the resultant soft actuators could produce mechanical work upon light control that has been further successfully employed for weight-lifting and cargo transporting, thus laying the foundation toward the construction of novel smart materials that can perform programmed events.

Orthogonally Engineered Albumin with Attenuated Macrophage Phagocytosis for the Targeted Visualization and Phototherapy of Liver Cancer.

The five-year survival rate of hepatocellular carcinoma (HCC) remains unsatisfactory. This reflects, in part, the paucity of effective methods that allow the target-specific diagnosis and therapy of HCC. Here, we report a strategy based on engineered human serum albumin (HSA) that permits the HCC-targeted delivery of diagnostic and therapeutic agents. Covalent cysteine conjugation combined with the exploitation of host-guest chemistry was used to effect the orthogonal functionalization of HSA with two functionally independent peptides. One of these peptides targets glypican-3 (GPC-3), an HCC-specific biomarker, while the second reduces macrophage phagocytosis through immune-checkpoint stimulation. This orthogonally engineered HSA proved effective for the GPC-3-targeted delivery of near-infrared fluorescent and phototherapeutic agents, thus permitting target-specific optical visualization and photodynamic ablation of HCC in vivo. This study thus offers new insights into specificity-enhanced fluorescence-guided surgery and phototherapy of HCC through the orthogonal engineering of biocompatible proteins.

Exploration of immunotherapy in advanced pulmonary lymphoepithelioma-like carcinoma.

Pulmonary lymphoepithelioma-like carcinoma (PLELC) is a rare and histologically distinctive subtype of nonsmall cell lung cancer (NSCLC). High expression of programmed death ligand 1 (PD-L1) and scarcity of druggable driver mutations raise the potential of immunotherapy for advanced PELEC. However, evidence on the clinical impact of immune-checkpoint inhibitors (ICIs) remained limited and unconvincing. The present study retrospectively enrolled advanced PLELC patients who received ICIs either as up-front or salvage therapy in SYSUCC between March 15, 2017 and March 15, 2022. The comparative efficacy of chemoimmunotherapy vs chemotherapy in the first-line setting and chemoimmunotherapy vs ICIs monotherapy in the ≥2 line setting was investigated. A total of 96 patients were finally enrolled; 49 PLELC patients received immunotherapy plus platinum-based chemotherapy, while 45 patients received platinum-based chemotherapy as first-line treatment. Patients with chemoimmunotherapy significantly obtain more survival benefits than those receiving chemotherapy (median progression-free survival [PFS]: 15.6 vs 8.6 months, P = .0015). Additionally, patients with chemoimmunotherapy obtained more PFS benefits than those with ICIs monotherapy in the ≥2 line of therapy (median PFS: 21.7 months vs 7.8 months, P = .094). A significant correlation was observed between prognostic nutritional index (PNI) and favorable treatment outcomes in patients receiving first-line chemoimmunotherapy (median PFS: 17.8 months vs 7.6 months, P < .0001). Likewise, patients in the monocyte-to-lymphocyte ratio (MLR)-high group had significantly shorter PFS than the MLR-low group (median PFS: 11.2 months vs not reached, P = .0009). Our study elucidated the superior efficacy of ICIs therapy, especially chemoimmunotherapy in advanced PLELC, which may provide new insight into the role of immunotherapy in advanced PLELC.

Spatiotemporal Evolution of the Global Species Diversity of Rhododendron.

Evolutionary radiation is a widely recognized mode of species diversification, but its underlying mechanisms have not been unambiguously resolved for species-rich cosmopolitan plant genera. In particular, it remains largely unknown how biological and environmental factors have jointly driven its occurrence in specific regions. Here, we use Rhododendron, the largest genus of woody plants in the Northern Hemisphere, to investigate how geographic and climatic factors, as well as functional traits, worked together to trigger plant evolutionary radiations and shape the global patterns of species richness based on a solid species phylogeny. Using 3,437 orthologous nuclear genes, we reconstructed the first highly supported and dated backbone phylogeny of Rhododendron comprising 200 species that represent all subgenera, sections, and nearly all multispecies subsections, and found that most extant species originated by evolutionary radiations when the genus migrated southward from circumboreal areas to tropical/subtropical mountains, showing rapid increases of both net diversification rate and evolutionary rate of environmental factors in the Miocene. We also found that the geographically uneven diversification of Rhododendron led to a much higher diversity in Asia than in other continents, which was mainly driven by two environmental variables, that is, elevation range and annual precipitation, and were further strengthened by the adaptation of leaf functional traits. Our study provides a good example of integrating phylogenomic and ecological analyses in deciphering the mechanisms of plant evolutionary radiations, and sheds new light on how the intensification of the Asian monsoon has driven evolutionary radiations in large plant genera of the Himalaya-Hengduan Mountains.

Indirect spectrum measurement via random phase modulation and detection in temporal domain.

Spectroscopy continues to provide possibilities for a deeper understanding of fundamental physical phenomena. Traditional spectral measurement method, dispersive Fourier transformation, is always limited by its realization condition (detection in the temporal far-field). Inspired by Fourier ghost imaging, we put forward an indirect spectrum measurement to overcome the limitation. The spectrum information is reconstructed via random phase modulation and near-field detection in the time domain. Since all operations are realized in the near-field region, the required length of dispersion fiber and optical loss are greatly reduced. Considering the application in spectroscopy, the length of required dispersion fiber, the spectrum resolution, the range of spectrum measurement and the requirement on bandwidth of photodetector are investigated.

Role of antiangiogenic agents in first-line treatment for advanced NSCLC in the era of immunotherapy.

BACKGROUND & OBJECTIVE: "Anti-angiogenetic drugs plus chemotherapy" (anti-angio-chemo) and "immune checkpoint inhibitors plus chemotherapy" (ICI-chemo) are superior to traditional chemotherapy in the first-line treatment of patients with advanced non-small-cell lung cancer (NSCLC). However, in the absence of a direct comparison of ICI-chemo with anti-angio-chemo, the superior one between them has not been decided, and the benefit of adding anti-angiogenetic agents to ICI-chemo remains controversial. This study aimed to investigate the role of antiangiogenic agents for advanced NSCLC in the era of immunotherapy. METHODS: Eligible randomized controlled trials (RCTs) comparing chemotherapy versus therapeutic regimens involving ICIs or anti-angiogenetic drugs were included. Outcomes included progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and rate of grade 3-4 toxicity assessment. R-4.3.1 was utilized to perform the analysis. RESULTS: A total of 54 studies with a sample size of 25,046 were finally enrolled. "Atezolizumab + Bevacizumab + Chemotherapy" significantly improved the ORR compared with "Atezolizumab + Chemotherapy" (Odds ratio (OR) = 2.73, 95% confidence interval (CI): 1.27-5.87). The trend also favored "Atezolizumab + Bevacizumab + Chemotherapy" in PFS and OS (hazard ratio (HR) = 0.71, 95% CI: 0.39-1.31; HR = 0.94, 95% CI: 0.77-1.16, respectively). In addition, "Pembrolizumab + Chemotherapy" and "Camrelizumab + Chemotherapy" significantly prolonged the PFS compared to "Bevacizumab + Chemotherapy" (HR = 0.65, 95% CI: 0.46-0.92; HR = 0.63, 95% CI: 0.41-0.97; respectively). Meanwhile, "Pembrolizumab + Chemotherapy" and "Sintilimab + Chemotherapy" yielded more OS benefits than "Bevacizumab + Chemotherapy" (HR = 0.69, 95% CI: 0.56-0.83; HR = 0.64, 95%CI: 0.46-0.91; respectively). Scheme between "Atezolizumab + Bevacizumab + Chemotherapy" and "Atezolizumab + Chemotherapy" made no significant difference (OR = 1.18, 95%CI: 0.56-2.42) concerning the rate of grade 3-4 toxicity. It seemed that ICI-chemo yielded more improvement in quality-adjusted life-year (QALY) than "Bevacizumab + Chemotherapy" in cost-effectiveness analysis. CONCLUSION: Our results suggest that ICI-chemo is associated with potentially longer survival, better cost-effectiveness outcomes, and comparable safety profiles than anti-angio-chemo. Also, adding bevacizumab to ICI-chemo seemed to provide additional therapeutic benefits without adding treatment burden. Our findings would supplement the current standard of care and help the design of future clinical trials for the first-line treatment of patients with advanced NSCLC.

An Anti-Noise Convolutional Neural Network for Bearing Fault Diagnosis Based on Multi-Channel Data.

In real world industrial applications, the working environment of a bearing varies with time, and some unexpected vibration noises from other equipment are inevitable. In order to improve the anti-noise performance of neural networks, a new prediction model and a multi-channel sample generation method are proposed to address the above problem. First, we proposed a multi-channel sample representation method based on the envelope time-frequency spectrum of a different channel and subsequent three-dimensional filtering to extract the fault features of samples. Second, we proposed a multi-channel data fusion neural network (MCFNN) for bearing fault discrimination, where the dropout technique is used in the training process based on a dataset with a wide rotation speed and various loads. In a noise-free environment, our experimental results demonstrated that the proposed method can reach a higher fault classification of 99.00%. In a noisy environment, the experimental results show that for the signal-to-noise ratio (SNR) of 0 dB, the fault classification averaged 11.80% higher than other methods and 32.89% higher under a SNR of -4 dB.

Highly Efficient Self-Assembly of Metallacages and Their Supramolecular Catalysis Behaviors in Microdroplets.

Developing a new strategy to improve the self-assembly efficiency of functional assemblies in a confined space and construct hybrid functional materials is a significant and fascinating endeavor. Herein, we present a highly efficient strategy for achieving the supramolecular self-assembly of well-defined metallacages in microdroplets through continuous-flow microfluidic devices. The high efficiency and versatility of this approach are demonstrated by the generation of five representative metallacages in different solvents containing water, DMF, acetonitrile, and methanol in a few minutes with nearly quantitative yields, in contrast to the yields obtained with the hour-scale reaction time in a batch reactor. A ring-opening catalytic reaction of the metallacages was selected as a model reaction for exploring supramolecular catalysis in microdroplets, whereby the catalytic yield was enhanced by 2.22-fold compared to that of the same reaction in the batch reactor. This work illustrates a new promising approach for the self-assembly of supramolecular systems.