Tumor-Derived Retinoic Acid Regulates Intratumoral Monocyte Differentiation to Promote Immune Suppression.

The immunosuppressive tumor microenvironment (TME) is a major barrier to immunotherapy. Within solid tumors, why monocytes preferentially differentiate into immunosuppressive tumor-associated macrophages (TAMs) rather than immunostimulatory dendritic cells (DCs) remains unclear. Using multiple murine sarcoma models, we find that the TME induces tumor cells to produce retinoic acid (RA), which polarizes intratumoral monocyte differentiation toward TAMs and away from DCs via suppression of DC-promoting transcription factor Irf4. Genetic inhibition of RA production in tumor cells or pharmacologic inhibition of RA signaling within TME increases stimulatory monocyte-derived cells, enhances T cell-dependent anti-tumor immunity, and synergizes with immune checkpoint blockade. Furthermore, an RA-responsive gene signature in human monocytes correlates with an immunosuppressive TME in multiple human tumors. RA has been considered as an anti-cancer agent, whereas our work demonstrates its tumorigenic capability via myeloid-mediated immune suppression and provides proof of concept for targeting this pathway for tumor immunotherapy.

Phase-dependent growth of Pt on MoS2 for highly efficient H2 evolution.

Crystal phase is a key factor determining the properties, and hence functions, of two-dimensional transition-metal dichalcogenides (TMDs)1,2. The TMD materials, explored for diverse applications3-8, commonly serve as templates for constructing nanomaterials3,9 and supported metal catalysts4,6-8. However, how the TMD crystal phase affects the growth of the secondary material is poorly understood, although relevant, particularly for catalyst development. In the case of Pt nanoparticles on two-dimensional MoS2 nanosheets used as electrocatalysts for the hydrogen evolution reaction7, only about two thirds of Pt nanoparticles were epitaxially grown on the MoS2 template composed of the metallic/semimetallic 1T/1T' phase but with thermodynamically stable and poorly conducting 2H phase mixed in. Here we report the production of MoS2 nanosheets with high phase purity and show that the 2H-phase templates facilitate the epitaxial growth of Pt nanoparticles, whereas the 1T' phase supports single-atomically dispersed Pt (s-Pt) atoms with Pt loading up to 10 wt%. We find that the Pt atoms in this s-Pt/1T'-MoS2 system occupy three distinct sites, with density functional theory calculations indicating for Pt atoms located atop of Mo atoms a hydrogen adsorption free energy of close to zero. This probably contributes to efficient electrocatalytic H2 evolution in acidic media, where we measure for s-Pt/1T'-MoS2 a mass activity of 85 ± 23 A [Formula: see text] at the overpotential of -50 mV and a mass-normalized exchange current density of 127 A [Formula: see text] and we see stable performance in an H-type cell and prototype proton exchange membrane electrolyser operated at room temperature. Although phase stability limitations prevent operation at high temperatures, we anticipate that 1T'-TMDs will also be effective supports for other catalysts targeting other important reactions.

Phase Engineering of Nanomaterials: Transition Metal Dichalcogenides.

Crystal phase, a critical structural characteristic beyond the morphology, size, dimension, facet, etc., determines the physicochemical properties of nanomaterials. As a group of layered nanomaterials with polymorphs, transition metal dichalcogenides (TMDs) have attracted intensive research attention due to their phase-dependent properties. Therefore, great efforts have been devoted to the phase engineering of TMDs to synthesize TMDs with controlled phases, especially unconventional/metastable phases, for various applications in electronics, optoelectronics, catalysis, biomedicine, energy storage and conversion, and ferroelectrics. Considering the significant progress in the synthesis and applications of TMDs, we believe that a comprehensive review on the phase engineering of TMDs is critical to promote their fundamental studies and practical applications. This Review aims to provide a comprehensive introduction and discussion on the crystal structures, synthetic strategies, and phase-dependent properties and applications of TMDs. Finally, our perspectives on the challenges and opportunities in phase engineering of TMDs will also be discussed.

1T'-transition metal dichalcogenide monolayers stabilized on 4H-Au nanowires for ultrasensitive SERS detection.

Unconventional 1T'-phase transition metal dichalcogenides (TMDs) have aroused tremendous research interest due to their unique phase-dependent physicochemical properties and applications. However, due to the metastable nature of 1T'-TMDs, the controlled synthesis of 1T'-TMD monolayers (MLs) with high phase purity and stability still remains a challenge. Here we report that 4H-Au nanowires (NWs), when used as templates, can induce the quasi-epitaxial growth of high-phase-purity and stable 1T'-TMD MLs, including WS2, WSe2, MoS2 and MoSe2, via a facile and rapid wet-chemical method. The as-synthesized 4H-Au@1T'-TMD core-shell NWs can be used for ultrasensitive surface-enhanced Raman scattering (SERS) detection. For instance, the 4H-Au@1T'-WS2 NWs have achieved attomole-level SERS detections of Rhodamine 6G and a variety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins. This work provides insights into the preparation of high-phase-purity and stable 1T'-TMD MLs on metal substrates or templates, showing great potential in various promising applications.

Recent Progress on Phase Engineering of Nanomaterials.

As a key structural parameter, phase depicts the arrangement of atoms in materials. Normally, a nanomaterial exists in its thermodynamically stable crystal phase. With the development of nanotechnology, nanomaterials with unconventional crystal phases, which rarely exist in their bulk counterparts, or amorphous phase have been prepared using carefully controlled reaction conditions. Together these methods are beginning to enable phase engineering of nanomaterials (PEN), i.e., the synthesis of nanomaterials with unconventional phases and the transformation between different phases, to obtain desired properties and functions. This Review summarizes the research progress in the field of PEN. First, we present representative strategies for the direct synthesis of unconventional phases and modulation of phase transformation in diverse kinds of nanomaterials. We cover the synthesis of nanomaterials ranging from metal nanostructures such as Au, Ag, Cu, Pd, and Ru, and their alloys; metal oxides, borides, and carbides; to transition metal dichalcogenides (TMDs) and 2D layered materials. We review synthesis and growth methods ranging from wet-chemical reduction and seed-mediated epitaxial growth to chemical vapor deposition (CVD), high pressure phase transformation, and electron and ion-beam irradiation. After that, we summarize the significant influence of phase on the various properties of unconventional-phase nanomaterials. We also discuss the potential applications of the developed unconventional-phase nanomaterials in different areas including catalysis, electrochemical energy storage (batteries and supercapacitors), solar cells, optoelectronics, and sensing. Finally, we discuss existing challenges and future research directions in PEN.

Boosting the reaction kinetics in aprotic lithium-carbon dioxide batteries with unconventional phase metal nanomaterials.

Given the high energy density and eco-friendly characteristics, lithium-carbon dioxide (Li-CO2) batteries have been considered to be a next-generation energy technology to promote carbon neutral and space exploration. However, Li-CO2 batteries suffer from sluggish reaction kinetics, causing large overpotential and poor energy efficiency. Here, we observe enhanced reaction kinetics in aprotic Li-CO2 batteries with unconventional phase 4H/face-centered cubic (fcc) iridium (Ir) nanostructures grown on gold template. Significantly, 4H/fcc Ir exhibits superior electrochemical performance over fcc Ir in facilitating the round-trip reaction kinetics of Li+-mediated CO2 reduction and evolution, achieving a low charge plateau below 3.61 V and high energy efficiency of 83.8%. Ex situ/in situ studies and theoretical calculations reveal that the boosted reaction kinetics arises from the highly reversible generation of amorphous/low-crystalline discharge products on 4H/fcc Ir via the Ir-O coupling. The demonstration of flexible Li-CO2 pouch cells with 4H/fcc Ir suggests the feasibility of using unconventional phase nanomaterials in practical scenarios.

A WRI1-dependent module is essential for the accumulation of auxin and lipid in somatic embryogenesis of Arabidopsis thaliana.

The potential for totipotency exists in all plant cells; however, the underlying mechanisms remain largely unknown. Earlier findings have revealed that the overexpression of LEAFY COTYLEDON 2 (LEC2) can directly trigger the formation of somatic embryos on the cotyledons of Arabidopsis. Furthermore, cotyledon cells that overexpress LEC2 accumulate significant lipid reserves typically found in seeds. The precise mechanisms and functions governing lipid accumulation in this process remain unexplored. In this study, we demonstrate that WRINKLED1 (WRI1), the key regulator of lipid biosynthesis, is essential for somatic embryo formation, suggesting that WRI1-mediated lipid biosynthesis plays a crucial role in the transition from vegetative to embryonic development. Our findings indicate a direct interaction between WRI1 and LEC2, which enhances the enrichment of LEC2 at downstream target genes and stimulates their induction. Besides, our data suggest that WRI1 forms a complex with LEC1, LEC2, and FUSCA3 (FUS3) to facilitate the accumulation of auxin and lipid for the somatic embryo induction, through strengthening the activation of YUCCA4 (YUC4) and OLEOSIN3 (OLE3) genes. Our results uncover a regulatory module controlled by WRI1, crucial for somatic embryogenesis. These findings provide valuable insights into our understanding of plant cell totipotency.

Nickel-Catalyzed Reductive Amidation of Aryl Fluorosulfates with Isocyanates: Synthesis of Amides via C-O Bond Cleavage.

With the assistance of nickel as catalyst, 2,2'-bipyridine (bpy) as ligand, and manganese as reducing metal, the reductive amidation of isocyanates with readily accessible aryl fluorosulfates could be successfully accomplished. The reactions proceeded effectively via C-O bond activation in DMF at room temperature, enabling the facile synthesis of a range of structurally diverse amides in moderate to high yields with broad functionality compatibility. In addition, the synthetic usefulness of the method was further demonstrated by applying the reaction in scale-up synthesis and the late-stage functionalization of complex molecules with biological activities.

Atomically Dispersed Vanadium-Induced Ru-V Dual Active Sites Enable Exceptional Performance for Acidic Water Oxidation.

Regulating the catalytic reaction pathway to essentially break the activity/stability trade-off that limits RuO2 and thus achieves exceptional stability and activity for the acidic oxygen evolution reaction (OER) is important yet challenging. Herein, we propose a novel strategy of incorporating atomically dispersed V species, including O-bridged V dimers and V single atoms, into RuO2 lattices to trigger direct O-O radical coupling to release O2 without the generation of *OOH intermediates. Vn-RuO2 showed high activity with a low overpotential of 227 mV at 10 mA cm-2 and outstanding stability during a 1050 h test in acidic electrolyte. Operando spectroscopic studies and theoretical calculations revealed that compared with the V single atom-doping case, the introduction of the V dimer into RuO2 further decreases the Ru-V atomic distance and weakens the adsorption strength of the *O intermediate to the active V site, which supports the more energetically favorable oxygen radical coupling mechanism (OCM). Furthermore, the highly asymmetric Ru-O-V local structure stabilizes the surface Ru active center by lowering the valence state and increasing the resistance against overoxidation, which result in outstanding stability. This study provides insight into ways of increasing the intrinsic catalytic activity and stability of RuO2 by atomically dispersed species modification.

Reversible Semimetal-Semiconductor Transition of Unconventional-Phase WS2 Nanosheets.

Phase transition with band gap modulation of materials has gained intensive research attention due to its various applications, including memories, neuromorphic computing, and transistors. As a powerful strategy to tune the crystal phase of transition-metal dichalcogenides (TMDs), the phase transition of TMDs provides opportunities to prepare new phases of TMDs for exploring their phase-dependent property, function, and application. However, the previously reported phase transition of TMDs is mainly irreversible. Here, we report a reversible phase transition in the semimetallic 1T'-WS2 driven by proton intercalation and deintercalation, resulting in a newly discovered semiconducting WS2 with a novel unconventional phase, denoted as the 1T'd phase. Impressively, an on/off ratio of >106 has been achieved during the phase transition of WS2 from the semimetallic 1T' phase to the semiconducting 1T'd phase. Our work not only provides a unique insight into the phase transition of TMDs via proton intercalation but also opens up possibilities to tune their physicochemical properties for various applications.

Mineralization of Few-Layer Graphene Made It Bioavailable in Chlamydomonas reinhardtii.

Numerous studies have emphasized the toxicity of graphene-based nanomaterials to algae, however, the fundamental behavior and processes of graphene in biological hosts, including its transportation, metabolization, and bioavailability, are still not well understood. As photosynthetic organisms, algae are key contributors to carbon fixation and may play an important role in the fate of graphene. This study investigated the biological fate of 14C-labeled few-layer graphene (14C-FLG) in Chlamydomonas reinhardtii (C. reinhardtii). The results showed that 14C-FLG was taken up by C. reinhardtii and then translocated into its chloroplast. Metabolomic analysis revealed that 14C-FLG altered the metabolic profiles (including sugar metabolism, fatty acid, and tricarboxylic acid cycle) of C. reinhardtii, which promoted the photosynthesis of C. reinhardtii and then enhanced their growth. More importantly, the internalized 14C-FLG was metabolized into 14CO2, which was then used to participate in the metabolic processes required for life. Approximately 61.63%, 25.31%, and 13.06% of the total radioactivity (from 14CO2) was detected in carbohydrates, lipids, and proteins of algae, respectively. Overall, these results reveal the role of algae in the fate of graphene and highlight the potential of available graphene in bringing biological effects to algae, which helps to better assess the environmental risks of graphene.

Right atrial wall inflammation detected by 18F-FDG PET/CT may be significantly associated with persistent atrial fibrillation: a prospective case-control study.

AIM: Atrial fibrillation (AF) is a progressive disease from paroxysmal to persistent, and persistent AF (PerAF) had worse prognosis. AF has potential link with inflammation, but it is not clear whether PerAF or paroxysmal AF (ParAF) is more closely related to inflammation. On the basis of inhibiting myocardial physiological uptake, 18F-fluorodeoxyglucosepositron emission tomography/computed tomography (18F-FDG PET/CT) is an established imaging modality to detect cardiac inflammation. We aimed to decipher the association between AF and atrial inflammatory activity by 18F-FDG PET/CT. METHODS: Thirty-five PerAF patients were compared to age and sex matched ParAF group with baseline 18F-FDG PET/CT scans prior to radiofrequency catheter ablation (RFCA) in the prospective case-control study. High-fat and low-carbohydrate diet and prolonged fast (HFLC+Fast) was applied to all AF patients before PET/CT. Then 22 AF patients with positive right atrial (RA) wall FDG uptake (HFLC+Fast) were randomly selected and underwent HFLC+Fast+heparin the next day. The CHA2DS2-VASc score was calculated to evaluate the risk of stroke. Clinical data, ECG, echocardiography, and atrial 18F-FDG uptake were compared. RESULTS: PerAF patients had significantly higher probability of RA wall positive FDG uptake and higher SUVmax than ParAF group [91.4% VS. 28.6%, P < 0.001; SUVmax: 4.10(3.20-4.90) VS. 2.60(2.40-3.10), P < 0.001]. Multivariate logistic regression analyses demonstrated that RA wall SUVmax was the independent influencing factor of PerAF (OR = 1.80, 95%CI 1.02-3.18, P = 0.04). In 22 AF patients with RA wall positive FDG uptake (HFLC+Fast), the "HFLC+Fast+Heparin" method did not significantly change RA wall FDG uptake evaluated by either quantitative analysis or visual analysis. High CHA2DS2-VASc score group had higher RA wall 18F-FDG uptake [3.35 (2.70, 4.50) vs, 2.8 (2.4, 3.1) P = 0.01]. CONCLUSIONS: RA wall FDG positive uptake was present mainly in PerAF. A higher RA wall 18F-FDG uptake was an independent influencing factor of PerAF. RA wall FDG uptake based on 18F-FDG PET/CT may indicate pathological inflammation. TRIAL REGISTRATION: http://www.chictr.org.cn , ChiCTR2000038288.

Identification of lncRNAs associated with uterine corpus endometrial cancer prognosis based on the competing endogenous RNA network.

Uterine Corpus Endometrial Carcinoma (UCEC) is one of the major malignant tumors of the female reproductive system. However, there are limitations in the currently available diagnostic approaches for UCEC. Long non-coding RNAs (lncRNAs) play important roles in regulating biological processes as competitive endogenous RNA (ceRNA) in tumors. To study the potential of lncRNAs as non-invasive diagnostic tumor markers, RNA-sequencing dataset of UCEC patients from The Cancer Genome Atlas was used to identify differentially expressed genes. A lncRNA-miRNA-mRNA ceRNA network was constructed by differentially expressed lncRNAs, miRNAs and miRNAs. Pathway enrichment and functional analysis for the mRNAs in the constructed ceRNA network provide the direction of future research for UCEC by demonstrating the most affected processes and pathways. Seven potential lncRNA biomarkers (C20orf56, LOC100144604, LOC100190940, LOC151534, LOC727677, FLJ35390, LOC158572) were validated in UCEC patients by quantitative real-time PCR. Notably, LOC100190940 and LOC158572 were identified as novel RNA molecules with unknown functions. Receiver operating characteristic (ROC) curve analysis demonstrated that the combined 7 lncRNAs had a high diagnostic value for UCEC patients with area under curve (AUC) of 0.941 (95% CI: 0.875-0.947). Our study highlights the potential of the validated 7 lncRNAs panel as diagnostic biomarkers in UCEC, providing new insights into the UCEC pathogenesis.

Preparation of Au@Pd Core-Shell Nanorods with fcc-2H-fcc Heterophase for Highly Efficient Electrocatalytic Alcohol Oxidation.

Controlled construction of bimetallic nanostructures with a well-defined heterophase is of great significance for developing highly efficient nanocatalysts and investigating the structure-dependent catalytic performance. Here, a wet-chemical synthesis method is used to prepare Au@Pd core-shell nanorods with a unique fcc-2H-fcc heterophase (fcc: face-centered cubic; 2H: hexagonal close-packed with a stacking sequence of "AB"). The obtained fcc-2H-fcc heterophase Au@Pd core-shell nanorods exhibit superior electrocatalytic ethanol oxidation performance with a mass activity as high as 6.82 A mgPd-1, which is 2.44, 6.96, and 6.43 times those of 2H-Pd nanoparticles, fcc-Pd nanoparticles, and commercial Pd/C, respectively. The operando infrared reflection absorption spectroscopy reveals a C2 pathway with fast reaction kinetics for the ethanol oxidation on the prepared heterophase Au@Pd nanorods. Our experimental results together with density functional theory calculations indicate that the enhanced performance of heterophase Au@Pd nanorods can be attributed to the unconventional 2H phase, the 2H/fcc phase boundary, and the lattice expansion of the Pd shell. Moreover, the heterophase Au@Pd nanorods can also serve as an efficient catalyst for the electrochemical oxidation of methanol, ethylene glycol, and glycerol. Our work in the area of phase engineering of nanomaterials (PENs) opens the way for developing high-performance electrocatalysts toward future practical applications.

Surface Molecular Functionalization of Unusual Phase Metal Nanomaterials for Highly Efficient Electrochemical Carbon Dioxide Reduction under Industry-Relevant Current Density.

The electrochemical carbon dioxide reduction reaction (CO2 RR) provides a sustainable strategy to relieve global warming and achieve carbon neutrality. However, the practical application of CO2 RR is still limited by the poor selectivity and low current density. Here, the surface molecular functionalization of unusual phase metal nanomaterials for high-performance CO2 RR under industry-relevant current density is reported. It is observed that 5-mercapto-1-methyltetrazole (MMT)-modified 4H/face-centered cubic (fcc) gold (Au) nanorods demonstrate greatly enhanced CO2 RR performance than original oleylamine (OAm)-capped 4H/fcc Au nanorods in both an H-type cell and flow cell. Significantly, MMT-modified 4H/fcc Au nanorods deliver an excellent carbon monoxide selectivity of 95.6% under the industry-relevant current density of 200 mA cm-2 . Density functional theory calculations reveal distinct electronic modulations by surface ligands, in which MMT improves while OAm suppresses the surface electroactivity of 4H/fcc Au nanorods. Furthermore, this method can be extended to various MMT derivatives and conventional fcc Au nanostructures in boosting CO2 RR performance.

A Bridge to Alkaloid Synthesis.

The construction of a structurally rigid architecture with chiral complexity, necessary to enhance the interaction with binding sites of drug targets, has been adapted as an intriguing approach in drug development. In the past few years, we have been interested in the synthesis of biologically significant and bridged alkaloids via novel synthetic methods and strategies based on recognition of the privileged pattern. Therefore, nitroso-ene and aza-Wacker cyclizations were elevated for the first time to construct bridged alkaloids, such as hosieine A, kopsone, melinonine-E and strychnoxanthine. Mechanistic investigations, including computational calculations for nitroso-ene reaction and deuterated experiments for aza-Wacker reaction, enable us to gain more insights into the chemical reactivity and selectivity of specific functional groups in developing viable synthetic methods.

Chronic neutrophilic leukemia complicated with monoclonal gammopathy of undetermined significance: A case report and literature review.

BACKGROUND: Study of the molecular biological characteristics of chronic neutrophilic leukemia complicated with plasma cell disorder (CNL-PCD) and lymphocytic proliferative disease (CNL-LPD). METHODS: The clinical data of a patient with chronic neutrophilic leukemia complicated with monoclonal gammopathy of undetermined significance (CNL-MGUS) in our hospital were reviewed, and the Chinese and/or English literature about CNL-PCD and CNL-LPD in PubMed and the Chinese database CNKI in the past 10 years was searched to analyze the molecular biological characteristics of this disease. RESULTS: A 73-year-old male had persistent leukocytosis for 18 months. The white blood cell count was 46.77 × 109/L and primarily composed of mature neutrophils; hemoglobin: 77 g/L; platelet count: 189 × 109/L. Serum immunofixation electrophoresis showed IgG-λ monoclonal M protein. A CT scan showed splenomegaly. Next-generation sequencing (NGS) showed that CSF3R T618I, ASXL1 and RUNX1 mutations were positive. It was diagnosed as CNL-MGUS. We summarized 10 cases of CNL-PCD and 1 case of CNL-LPD who underwent genetic mutation detection reported in the literature. The CSF3R mutational frequency (7/11, 63.6%) was lower than that of isolated CNL. The ASXL1 mutations were all positive (3/3), which may represent a poor prognostic factor. The SETBP1 mutation may promote the progression of CNL-PCD. We also found JAK2, RUNX1, NRAS, etc. in CNL-PCD. CONCLUSIONS: Chronic neutrophilic leukemia may be more inclined to coexist with plasma cell disorder. The CSF3R mutation in CNL-PCD is still the most common mutated gene compared with isolated CNL. Mutations in SETBP1 and ASXL1 may be poor prognostic factors for CNL-PCD.

Construction and validation of a three-microRNA signature as prognostic biomarker in patients with hepatocellular carcinoma.

Hepatocellular carcinoma (HCC), a common type of primary liver cancer, is one of the most aggressive malignant tumors worldwide. Although overall survival (OS) rates for HCC has significantly improved in recent years, however, the exact predictive value of microRNA (miRNA) for the prognosis of HCC has not yet been recognized. Here, we aimed to identify potential prognostic miRNAs involved in HCC by bioinformatics analysis and validated expression levels through quantitative polymerase chain reaction (qPCR) and GEO database. The RNA expression profiles and corresponding clinical information of HCC were available from The Cancer Genome Atlas (TCGA) datasets. Differentially expression and standardization analysis of miRNAs, Kaplan-Meier curve and time dependent ROC curve were performed by using R tools. Differentially expressed miRNAs (DEmiRNAs) and clinical parameters involved in the OS of HCC were confirmed by Cox regression models. And functional enrichment analysis was used to establish functions of the targeted genes of DEmiRNAs. A total of 300 DEmiRNAs were significantly related with HCC, of which 40 were down-regulated and 260 were up-regulated. A total of 344 patients with DEmiRNAs, status, overall survival (OS) time were randomized into training group (172) and test group (172). Multivariate Cox regression analyses revealed that 3 miRNA (hsa-miR-139-3p, hsa-miR-760, hsa-miR-7-5p) had independent prognostic significance for the OS of HCC in both training and test group. Moreover, according to Kaplan Meier analysis, the OS of HCC patients with high-risk score was shorter in validation and entire series. The time dependent ROC curve demonstrated high accuracy of the signature for OS. Besides, target genes of three miRNAs were analyzed by functional enrichment analysis and 20 genes associated with OS were verified by using Kaplan-Meier method. Compared with normal and benign group, the relative expression level of hsa-miR-139-3p was significantly decreased, while hsa-miR-7-5p and hsa-miR-760 were distinctly increased in the plasma of HCC patients. The same results were observed in the independent cohort. Collectively, our research suggested that three-miRNA signature could serve as an independent prognostic indicator for HCC patients.

Rational Synthesis of 1D Hyperbranched Heterostructures with Enhanced Optoelectronic Performance.

One-dimensional (1D) hyperbranched heterostructures (HBHSs) with abundant interfaces are rendered with various interfacial phenomena and functionalities. However, the rational synthesis of 1D HBHSs with desired spatial architecture and specific interface remains a great challenge. Here, we report a seeded growth method for controlled synthesis of two extraordinary types of HBHSs, in which high-intensity of CdS branches selectively grow on 1D nanowire (NW) trunks with different growth behaviors. The composition of the HBHSs can be further tuned by combining with cation exchange method, which enriches the variety of the HBHSs. The optoelectronic devices based on a single HBHS were fabricated and exhibit a better photoresponse performance compared with that of a single NW trunk. This advance provides a strategy for the controlled synthesis HBHSs with complex morphology and offers a platform for exploring their applications for photo harvesting and conversion.

The BIG gene controls size of shoot apical meristems in Arabidopsis thaliana.

KEY MESSAGE: BIG regulates the shoot stem cell population. The shoot apical meristem (SAM) contains a population of self-renewing cells, and provides daughter cells for initiation and development of aerial parts of plants. However, the underlying mechanisms of SAM size regulation remain largely unclear. Here, we identified a mutant that displayed a large SAM, designated big-shoot meristem (big-m), in Arabidopsis thaliana. The phenotype of big-m is caused by a new T-DNA insertion allele of BIG, causing a loss of function. The big-m mutant had more stem cells in the SAM than in the wild type. Expression of WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM) was promoted in big-m compared with the wild type, showing that BIG functions upstream of WUS and STM. Therefore, BIG is an important regulator of the stem cell population in the SAM. Furthermore, genetic analysis indicated that BIG acts synergistically with PIN-FORMED1 (PIN1) in controlling SAM size. Our results suggest that BIG plays an important role in controlling Arabidopsis thaliana SAM growth via PIN1-mediated auxin homeostasis.