Unraveling a Concerted Proton-Coupled Electron Transfer Pathway in Atomically Precise Gold Nanoclusters.

Metal nanoclusters (MNCs) represent a promising class of materials for catalytic carbon dioxide and proton reduction as well as dihydrogen oxidation. In such reactions, multiple proton-coupled electron transfer (PCET) processes are typically involved, and the current understanding of PCET mechanisms in MNCs has primarily focused on the sequential transfer mode. However, a concerted transfer pathway, i.e., concerted electron-proton transfer (CEPT), despite its potential for a higher catalytic rate and lower reaction barrier, still lacks comprehensive elucidation. Herein, we introduce an experimental paradigm to test the feasibility of the CEPT process in MNCs, by employing Au18(SR)14 (SR denotes thiolate ligand), Au22(SR)18, and Au25(SR)18- as model clusters. Detailed investigations indicate that the photoinduced PCET reactions in the designed system proceed via an CEPT pathway. Furthermore, the rate constants of gold nanoclusters (AuNCs) have been found to be correlated with both the size of the cluster and the flexibility of the Au-S framework. This newly identified PCET behavior in AuNCs is prominently different from that observed in semiconductor quantum dots and plasmonic metal nanoparticles. Our findings are of crucial importance for unveiling the catalytic mechanisms of quantum-confined metal nanomaterials and for the future rational design of more efficient catalysts.

Diabetes-induced male infertility: potential mechanisms and treatment options.

Male infertility is a physiological phenomenon in which a man is unable to impregnate a fertile woman during a 12-month period of continuous, unprotected sexual intercourse. A growing body of clinical and epidemiological evidence indicates that the increasing incidence of male reproductive problems, especially infertility, shows a very similar trend to the incidence of diabetes within the same age range. In addition, a large number of previous in vivo and in vitro experiments have also suggested that the complex pathophysiological changes caused by diabetes may induce male infertility in multiple aspects, including hypothalamic-pituitary-gonadal axis dysfunction, spermatogenesis and maturation disorders, testicular interstitial cell damage erectile dysfunction. Based on the above related mechanisms, a large number of studies have focused on the potential therapeutic association between diabetes progression and infertility in patients with diabetes and infertility, providing important clues for the treatment of this population. In this paper, we summarized the research results of the effects of diabetes on male reproductive function in recent 5 years, elaborated the potential pathophysiological mechanisms of male infertility induced by diabetes, and reviewed and prospected the therapeutic measures.

Cyclometalated gold(III)-hydride under oriented external electric fields: a new strategy to modulate its reactivity?

Selected gold complexes have been regarded as promising anti-cancer agents because they can bind with protein targets containing thiol or selenol moieties, but their clinical applications were hindered by the unbiased binding towards off-target thiol-proteins. Recently, a novel gold(III)-hydride complex (abbreviated as 1) with visible light-induced thiol reactivity has been reported as potent photo-activated anticancer agents (Angew. Chem. Int. Ed., 2020, 132, 11139). To explore new strategies to stimuli this potential antitumor drug, the effect of oriented external electric fields (OEEFs) on its geometric structure, electronic properties, and chemical reactivity was systematically investigated. Results reveal that imposing external electric fields along the Au-H bond of 1 can effectively activate this bond, which is conducive to its dissociation and the binding of Au site to potential targets. Hence, this study provides a new OEEF-strategy to activate this reported gold(III)-hydride, revealing its potential application in electrochemical therapy. We anticipate this work could promote the development of more electric field-activated anticancer agents. However, further experimental research should be conducted to verify the conclusions obtained in this work.

Suzuki-Miyaura Cross-Coupling Reaction Catalyzed by Al12M (M = Be, Al, C, and P) Superatoms with Different Numbers of Valence Electrons.

The exploration of low-cost, efficient, environmentally safe, and selective catalysts for the activation of carbon-halogen bonds has become an important and challenging topic in modern chemistry. With the help of density functional theory (DFT), it is found that phenyl bromide (PhBr) can be efficiently chemisorbed by the Al12M (M = Be, Al, C, and P) superatoms via forming highly polarized Al-Br covalent bonds, where the C-Br bonds of PhBr can be effectively activated through the electron transfer from Al12M. The different electronic structures of these four Al12M superatoms pose a substantial effect on their performances on the activation of PhBr and the catalytic mechanisms of the Suzuki-Miyaura (SM) reaction. Among them, the alkali-metal-like superatom Al12P exhibits the best performance for the activation of PhBr. In particular, Al13 and Al12P with open-shell electronic structures exhibit catalytic performances comparable to those of previously reported catalysts for this coupling reaction. Hence, it is highly expected that Al13 and Al12P could be used as novel superatom catalysts for C-C coupling reactions and, therefore, open up new possibilities to use nonprecious superatoms in catalyzing the activation and transformation of carbon-halogen bonds.

Design and Experiment of an Unoccupied Control System for a Tracked Grain Vehicle.

In order to enhance crop harvesting efficiency, an automatic-driving tracked grain vehicle system was designed. Based on the harvester chassis, we designed the mechanical structure of a tracked grain vehicle with a loading capacity of 4.5 m3 and a grain unloading hydraulic system. Using the BODAS hydraulic controller, we implemented the design of an electronic control system that combines the manual and automatic operation of the chassis walking mechanism and grain unloading mechanism. We utilized a hybrid A* algorithm to plan the traveling path of the tracked grain vehicle, and the path-tracking controller of the tracked grain vehicle was designed by combining fuzzy control and pure pursuit algorithms. Leveraging binocular vision technology and semantic segmentation technology, we designed an automatic grain unloading control system with functions of grain tank recognition and grain unloading regulation control. Finally, we conducted experiments on automatic grain unloading control and automatic navigation control in the field. The results showed that both the precision of the path-tracking control and the automatic unloading system meet the requirements for practical unoccupied operations of the tracked grain vehicle.

A General Synthesis of Nanostructured Conductive Metal-Organic Frameworks from Insulating MOF Precursors for Supercapacitors and Chemiresistive Sensors.

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) are emerging as a unique subclass of layer-stacked crystalline coordination polymers that simultaneously possess porous and conductive properties, and have broad application potential in energy and electronic devices. However, to make the best use of the intrinsic electronic properties and structural features of 2D c-MOFs, the controlled synthesis of hierarchically nanostructured 2D c-MOFs with high crystallinity and customized morphologies is essential, which remains a great challenge. Herein, we present a template strategy to synthesize a library of 2D c-MOFs with controlled morphologies and dimensions via insulating MOFs-to-c-MOFs transformations. The resultant hierarchically nanostructured 2D c-MOFs feature intrinsic electrical conductivity and higher surface areas than the reported bulk-type 2D c-MOFs, which are beneficial for improved access to active sites and enhanced mass transport. As proof-of-concept applications, the hierarchically nanostructured 2D c-MOFs exhibit a superior performance for electrical properties related applications (hollow Cu-BHT nanocubes-based supercapacitor and Cu-HHB nanoflowers-based chemiresistive gas sensor), achieving over 225 % and 250 % improvement in specific capacity and response intensity over the corresponding bulk type c-MOFs, respectively.

Energy Level Engineering in Gold Nanoclusters for Exceptionally Bright NIR Electrochemiluminescence at a Low Trigger Potential.

Electrochemiluminescence (ECL) is a widely used light output mechanism from electrochemical excitation. Understanding the intrinsic essence for ideal ECL generation remains a fundamental challenge. Here, based on the molecular orbital theory, we reported an energy level engineering strategy to regulate the ECL performance by using ligand-protected gold nanoclusters (AuNCs) as luminophores and N,N-diisopropylethylamine (DIPEA) as a coreactant. The energy level matching between the AuNCs and DIPEA effectively promoted their electron transfer reactions, thus improving the excitation efficiency and reducing the trigger potential. Simultaneously, the narrow band gap of the AuNCs further enabled enhanced emission efficiency. Using the energy level engineering theory developed here, a dual-enhanced strategy was proposed, and ß-CD-AuNCs were designed to further verify this mechanism. The ß-CD-AuNCs/DIPEA system resulted in highly stable near-infrared ECL with an unprecedented ECL efficiency (145-fold higher than that of the classic Ru(bpy)32+/tetra-n-butylammonium perchlorate system) and a low trigger potential of 0.48 V. A visual NIR-ECL based on this ECL system was successfully realized by an infrared camera. This work provides an original mechanistic understanding for designing efficient ECL systems, which promises to be a harbinger for broad applicability of this strategy for other ECL systems and ECL sensing platforms.

On the Catalytic Performance of (ZrO)n (n=1-4) Clusters for CO Oxidation: A DFT Study.

The unique characteristic of superatoms to show chemical properties like those of individual atoms opens a new avenue towards replacing noble metals as catalysts. Given the similar electronic structures of the ZrO superatom and the Pd atom, the CO oxidation mechanisms catalysed by (ZrO)n (n=1-4) clusters were investigated in detail to evaluate their catalytic performance. Our results reveal that a single ZrO superatom exhibits superior catalytic ability in CO oxidation than both larger (ZrO)n (n=2-4) clusters and a Pd atom, indicating the promising potential of ZrO as a "single-superatom catalyst". Moreover, the mechanism of CO oxidation catalysed by ZrO+/- suggests that depositing a ZrO superatom onto the electron-rich substrates is a better choice for practical catalysis application. Accordingly, a graphene nanosheet (coronene) was chosen as a representative substrate for ZrO and Pd to assess their catalytic performances in CO oxidation. Acting as an "electron sponge", this carbon substrate can both donate and accept charges in different reaction steps, enabling the supported ZrO to achieve enhanced catalytic performance in this process with a low energy barrier of 19.63 kcal/mol. This paper presents a new realization on the catalytic performance of Pd-like superatom in CO oxidation, which could increase the interests in exploring noble metal-like superatoms as efficient catalysts for various reactions.

Upconversion luminescence nanosensor for detection of Fe3+ and phosphate ion based on the inner-filter effect.

In this work, an upconversion luminescence (UCL) nanosensor for fast detection of ferric ion (Fe3+) and phosphate ion (Pi) is developed based on the inner-filter effect (IFE) between NaYF4:Yb/Er upconversion nanoparticles (UCNPs) and Fe3+-hypocrellin B (HB) complex. Fe3+-HB complex has strong absorption band (450-650 nm), which overlaps with the green emission peak of UCNPs at 545 nm. By adding Fe3+ and Pi, the UCNPs-HB system produces the red-shift change of absorption spectrum, which leads to the "on-off-on" process of IFE. So, with the specific recognition ability of HB for Fe3+ and the competitive complexation of Pi for Fe3+, the proposed nanosensor utilizes the UCL change to achieve the detection of the targets. For the detections of Fe3+, the linear range is 10-600 µM with a limit of detection (LOD) of 2.62 µM, and for Pi, the linear range is 5-100 µM with a LOD of 1.25 µM. The results for selectivity, precision, and recovery test are also satisfactory. Furthermore, the real sample detection shows that the proposed nanaosensor has a great potential in environmental and biological systems. An upconversion luminescence (UCL) nanosensor based on the inner-filter effect (IFE) between upconversion nanoparticles (UCNPs) and Fe3+-hypocrellin B (HB) complex for the detection of Fe3+ and phosphate ion has been proposed, which is promising to be a convenient and sensitive assay for monitoring Fe3+ and phosphate ion in different environments and biological systems.

Theoretical prediction of superatom WSi12-based catalysts for CO oxidation by N2O.

Catalytic conversion of N2O and CO into nonharmful gases is of great significance to reduce their adverse impact on the environment. The potential of the WSi12 superatom to serve as a new cluster catalyst for CO oxidation by N2O is examined for the first time. It is found that WSi12 prefers to adsorb the N2O molecule rather than the CO molecule, and the charge transfer from WSi12 to N2O results in the full activation of N2O into a physically absorbed N2 molecule and an activated oxygen atom that is attached to an edge of the hexagonal prism structure of WSi12. After the release of N2, the remaining oxygen atom can oxidize one CO molecule via overcoming a rate-limiting barrier of 28.19 kcal mol-1. By replacing the central W atom with Cr and Mo, the resulting MSi12 (M = Cr and Mo) superatoms exhibit catalytic performance for CO oxidation comparable to the parent WSi12. In particular, the catalytic ability of WSi12 for CO oxidation is well maintained when it is extended into tube-like WnSi6(n+1) (n = 2, 4, and 6) clusters with energy barriers of 25.63-29.50 kcal mol-1. Moreover, all these studied MSi12 (M = Cr, Mo, and W) and WnSi6(n+1) (n = 2, 4, and 6) species have high structural stability and can absorb sunlight to drive the catalytic process. This study not only opens a new door for the atomically precise design of new silicon-based nanoscale catalysts for various chemical reactions but also provides useful atomic-scale insights into the size effect of such catalysts in heterogeneous catalysis.

Metalloborospherenes with a Stabilized Classical Fullerene-like Borospherene B40 Act as Nonlinear Optical Switches, Electron Reservoirs, Molecular Capacitors, and Molecular Reactors.

Using a new method of η5-Li and η6-Mg atoms capping the faces of the classical fullerene-like borospherene Td B40, we theoretically predict an exohedral metalloborospherene Td Mg10Li12&B40 molecule. Remarkably, a newfangled endoexo cage isomerism is proposed. Further, embedding Mg atoms in the Td B40 cage forms endohedral derivatives. Due to the intramolecular pull-push electron transfer relay, these obtained molecules possess unequal multilayered and alternant spherical charge distribution. The outer is an excess electron layer, bringing a molecular nonlinear switch character and an electron reservoir behavior with strong electron-donating and -accepting abilities. The middle (Mg2+)10(Li+)12 and the outer layers together constitute an electric double layer, presenting the behavior of a molecular capacitor where the electronic charge-discharge process occurs in the outer excess electron layer. The inner part is an empty cage B4026- with a strong negative electric field. The valence electrons of the embedded Mg atoms are transformed into new excess electrons and added in the outer excess electron layer, also exhibiting the charging behavior of the molecular capacitor. Considering the chemical reaction in the inner cage, the embedded Mg atom is ionized, forming an Mg2+ cation and 2e under the strong negative electric field; meanwhile, 2e is powerfully pushed into the outer excess electron layer. This chemical process shows a generalized Coulomb explosion, and thus the exohedral metalloborospherene molecules with cage B4026- may act as molecular reactors. The new species mark the genesis of classical fullerene-like borospherene chemistry and stimulate their applications in molecular nonlinear optical and nanoelectronics.

Transcranial Direct Current Stimulation Improves Some Neurophysiological Parameters but not Clinical Outcomes after Severe Traumatic Brain Injury.

BACKGROUND: Disorders of consciousness (DOC) are one of the clinical hallmarks of severe traumatic brain injury (TBI). DOC impair patient life quality and increase the burden on their families and society. METHODS: A double-blind, randomized, controlled clinical trial was conducted to determine the efficacy of routine rehabilitation combined with transcranial direct current stimulation (tDCS) in DOC patients after TBI. A total of 78 DOC patients were randomly divided after TBI into two groups: participants in the treatment group received routine rehabilitation combined with an active tDCS protocol. In contrast, participants in the control group received routine rehabilitation combined with a sham tDCS protocol. An anode was placed over the left dorsolateral prefrontal cortex and a cathode was placed over the right supraorbital area. The stimulation intensity was 2 mA. Both tDCS protocols lasted for eight consecutive weeks (20 minutes per day, six days per week). Patients were followed up for a further eight weeks. Glasgow Outcome Scale (GOS), Glasgow Coma Scale (GCS), brainstem auditory evoked potentials, somatosensory evoked potentials and electroencephalogram were measured at weeks zero, two, four, six, eight and sixteen from the start of tDCS. RESULTS: Neither the GOS nor GCS scores differed significantly between the two groups, while brainstem auditory evoked potentials, somatosensory evoked potentials and electroencephalogram scores did. CONCLUSIONS: This study found that tDCS improves some neurophysiological parameters but not clinical outcomes of DOC patients after TBI. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800014808 (The version is V.1.0). Registered on February 7, 2018. http://www.chictr.org.cn/showproj.aspx?proj=25003.

Sensitive, Highly Stable, and Anti-Fouling Electrode with Hexanethiol and Poly-A Modification for Exosomal microRNA Detection.

It remains a huge challenge to integrate the sensitivity, stability, reproducibility, and anti-fouling ability of electrochemical biosensors for practical applications. Herein, we propose a self-assembled electrode combining hexanethiol (HT), poly-adenine (poly-A), and cholesteryl-modified DNA to meet this challenge. HT can tightly pack at the electrode interface to form a hydrophobic self-assembled monolayer (SAM), effectively improving the stability and signal-to-noise ratio (SNR) of electrochemical detection. Cholesteryl-modified DNA was immobilized at the electrode through the hydrophobic interaction with HT to avoid the competition between the SAM and the DNA probe on the gold site. Thus, the assembly efficiency and uniformity of the DNA probe as well as the detection reproducibility were increased remarkedly. Poly-A was added on the HT assembled electrode to occupy the unreacted sites of gold to further enhance the anti-fouling ability. The combination of HT and poly-A allows the electrode to ensure favorable anti-fouling ability without sacrificing the detection performance. On this basis, we proposed a dual-signal amplification electrochemical biosensor for the detection of exosomal microRNAs, which showed excellent sensitivity with a detection limit down to 1.46 aM. Importantly, this method has been successfully applied to detect exosomal microRNA-21 in cells and human serum samples, proving its potential utility in cancer diagnosis.

Adaptation of prelimbic cortex mediated by IL-6/STAT3/Acp5 pathway contributes to the comorbidity of neuropathic pain and depression in rats.

BACKGROUND: The adaption of brain region is fundamental to the development and maintenance of nervous system disorders. The prelimbic cortex (PrL) participates in the affective components of the pain sensation. However, whether and how the adaptation of PrL contributes to the comorbidity of neuropathic pain and depression are unknown. METHODS: Using resting-state functional magnetic resonance imaging (rs-fMRI), genetic knockdown or overexpression, we systematically investigated the activity of PrL region in the pathogenesis of neuropathic pain/depression comorbid using the combined approaches of immunohistochemistry, electrophysiology, and behavior. RESULTS: The activity of PrL and the excitability of pyramidal neurons were decreased, and the osteoclastic tartrate-resistant acid phosphatase 5 (Acp5) expression in PrL neurons was upregulated following the acquisition of spared nerve injury (SNI)-induced comorbidity. Genetic knockdown of Acp5 in pyramidal neurons, but not parvalbumin (PV) neurons or somatostatin (SST) neurons, attenuated the decrease of spike number, depression-like behavior and mechanical allodynia in comorbidity rats. Overexpression of Acp5 in PrL pyramidal neurons decreased the spike number and induced the comorbid-like behavior in naïve rats. Moreover, the expression of interleukin-6 (IL-6), phosphorylated STAT3 (p-STAT3) and acetylated histone H3 (Ac-H3) were significantly increased following the acquisition of comorbidity in rats. Increased binding of STAT3 to the Acp5 gene promoter and the interaction between STAT3 and p300 enhanced acetylation of histone H3 and facilitated the transcription of Acp5 in PrL in the modeled rodents. Inhibition of IL-6/STAT3 pathway prevented the Acp5 upregulation and attenuated the comorbid-like behaviors in rats. CONCLUSIONS: These data suggest that the adaptation of PrL mediated by IL-6/STAT3/Acp5 pathway contributed to the comorbidity of neuropathic pain/depression induced by SNI.

Effects of Transcranial Direct Current Stimulation on Poststroke Dysphagia: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: This review aimed to systematically evaluate the effect of transcranial direct current stimulation (tDCS) on poststroke dysphagia. DATA SOURCES: PubMed, Cochrane Library (CENTRAL), Web of Science, VIP, CNKI, and Wanfang databases were systematically searched up to June 2021. STUDY SELECTION: Randomized controlled trials (RCTs) on the effects of tDCS on poststroke dysphagia. DATA EXTRACTION: The extracted data included the author, country of publication, time of publication, key elements of bias risk assessment (such as RCTs and blind methods), sample size and basic information (age, course of disease, stroke location), intervention measures, treatment methods of tDCS (stimulation location, intensity, duration), relevant outcome indicators, and relevant data (SDs).The Cochrane Risk of Bias Assessment Tool and Physiotherapy Evidence Database Scale were used to assess the risk of bias. DATA SYNTHESIS: Sixteen RCTs were included in this meta-analysis. Overall, the results revealed a large and statistically significant pooled effect size (0.80; confidence interval [CI], 0.45-1.14; P<.001). The subgroup that explored the course of the disease yielded a large and significant effect size for the chronic phase group (0.80; CI, 0.43-1.16; P<.001). For the stimulation intensity, 1 mA and 1.6 mA showed a moderate and significant effect sizes (0.47; CI, 0.13-0.81; P=.006 vs 1.39; CI, 0.69-2.08; P<.001). In the subgroup analyses, the affected (0.87; CI, 0.26-1.48; P=.005) vs unaffected (0.61; CI, 0.23-0.99; P=.002) hemisphere showed a significant result, and stimulation of the affected hemisphere had a more obvious effect. Subgroup analysis of stroke location showed that tDCS was effective for dysphagia after unilateral hemispheric stroke, bulbar paralysis, and brainstem stroke but not for dysphagia after ataxic and basal ganglia stroke. However, the subgroup analysis of stroke location revealed a significant result (0.81; CI, 0.44-1.18; P<.001). CONCLUSIONS: This meta-analysis demonstrated the height and significant beneficial effect of tDCS on improving poststroke dysphagia.

The Evaluation Indexes Suitable for Nonhuman Primates can be Extracted from Clinical Consciousness Disorder Assessment Scales: A Hypothesis.

BACKGROUND: Currently, case studies or clinical trials in different patient populations remain the main resource underlying the understanding of disorder of consciousness (DoC). This provides a low efficacy for the derivation of data and the implementation of associated controlled experimental designs. Preclinical models provide precise controls, reduced variability, rich data output and limited ethical complexity. Nonhuman primates are suitable model animals for disorders of consciousness due to their brain structure being very similar to that of humans. Behavioral tests remain the primary standard for assessing the consciousness status of humans. However, there is currently no behavioral assessment scale available for evaluation of the state of consciousness disorder in nonhuman primates. This presents a significant challenge for the establishment of different models of consciousness disorder. Therefore, there is considerable motivation to focus on the development of a proper tool for assessment of the state of consciousness associated with nonhuman primate models that are based on clinically common consciousness assessment scales. METHODS: It is assumed that the Delphi and level analysis methods based on clinical consciousness disorder assessment scales may provide an effective way to select and include assessment indexes for levels of consciousness in nonhuman primates. RESULTS: 8 first-level indicators with 41 second-level indexes were selected preliminary as a pool of evaluation entries of state of consciousness of nonhuman primates. CONCLUSIONS: It may be practicable to extract appropriate indicators for non-human primates from the clinical consciousness disorder assessment scales. Besides, a combination of Delphi method, behavioral analysis, electroencephalography, neuroimaging (such as positron emission tomography-computed tomography) and functional magnetic resonance imaging is necessary to test the reliability and validity of the novel scale reported here.

First Report of Leaf Blight Caused by Alternaria tenuissima on Senna nomame in China.

Senna nomame (Makino) T. C. Chen is an annual plant in the Fabaceae. This plant can be used in a tonic, as a diuretic, and for the prevention of obesity due to the presence of anthraquinones, flavonoids, and lipase inhibitors isolated from the aerial parts and seeds (Hatano et al. 1997). In June to September 2019, a severe foliar blight was observed on the leaves of 1-year-old S. nomame landrace plants in Qinglong (40.41°N, 118.95°E) in Qinhuangdao City, Hebei Province, China. The incidence of leaf blight was as high as 67% in the fields (n≥3). Symptoms began with small, brown spots at the margins and tips of leaves, with gray or yellowish-brown spots in the center of leaves. The spots gradually expanded to irregular large yellowish-brown lesions, and the leaves gradually withered. The pathogen was isolated from 20 leaves with typical symptoms from 10 individual plants. Leaf pieces (2 to 4 mm2) were excised from the junction of diseased and healthy tissues, disinfected in 75% ethanol for 15 s, rinsed in sterile distilled water, and placed on potato dextrose agar (PDA) plates. Colonies of 69% of the isolated fungi had round margins, and the olive-green fluffy aerial mycelia began to sporulate after 3 days at 28°C. On potato carrot agar (PCA), pure cultures formed yellowish brown mycelium with a light-colored, taupe-white center. Conidiophores were brown, simple or branched, and produced numerous conidia in short chains of three to six conidia. The conidia (n=50) were inverted pear-shaped or orbicular-ovate, light brown to brown, with a cylindrical short beak at the tip, and 19.9 to 30.4 µm (mean 25.4±3.6 µm) × 10.4 to 17.1 µm (mean 13.4±1.9 µm), with two to four transverse septa and zero to three longitudinal septa. The fungal isolates U-2, U-2-1, and U-2-2 were further characterized by sequencing of the rDNA ITS (MN712241, MZ781312, MZ781313), actin (ACT) (MN752246, MZ593671, MZ593672), calmodulin (CAL) (ON811636 to ON811638), ATPase (ON872785 to ON872787), and Alt a 1 (ON792172 to ON792174) genes using ITS1/ITS4, ACT-512F/ACT-738R, CALDF1/CALDR1, ATPDF1/ATPDR1, and Alt-for/Alt-rev primers for PCR amplification, respectively (Yang et al. 2009; Elfar et al. 2018). The sequences of the amplicons showed 99% to 100% identity with Alternaria tenuissima isolates: ITS (569/570 bp; MK560480 ), ACT (243/243 bp; MK593135), Alt a 1 (509/512 bp; MK593137), CAL (717/721 bp; MG925128), ATPase (1196/1197 bp; MG740623). Therefore, based on morphological characteristics and DNA sequence data, the isolates were identified as A. tenuissima. For pathogenicity tests, leaves on 10 healthy 1-year-old potted S. nomame plants were inoculated by wounding with a sterile needle and sprayed with a conidial suspension (2×105 spores/mL). Sterile water was used as the control. Inoculated plants were incubated in a greenhouse at 28°C with a 12 h photoperiod (75% to 80% relative humidity). The pathogenicity test was repeated three times. Lesions were observed on inoculated plants seven to nine days after inoculation, but no lesions were observed on control plants. A. tenuissima was successfully re-isolated from the symptomatic leaves and identified by morphology and sequencing of PCR amplicons. A. tenuissima has caused brown leaf spot on kiwifruit (Li et al. 2019) in China and pigeonpea (Sharma et al. 2012) in India. To our knowledge, this is the first report of A. tenuissima causing leaf blight on S. nomame in China. This new finding is essential in the diagnosis and management in field production.

Highly Conductive Ligand-Free Cs2 PtBr6 Perovskite Nanocrystals with a Narrow Bandgap and Efficient Photoelectrochemical Performance.

Design of high-performance all-inorganic halide perovskites, especially lead-free perovskites, is key to the broadening of its application prospects. Herein, the authors report the synthesis of ligand-free cesium platinum (IV) bromide nanocrystals (Cs2 PtBr6 NCs), a new kind of vacancy-ordered lead-free perovskite nanomaterial, by a facile one-pot method. The Cs2 PtBr6 NCs exhibits a narrow band gap of 1.32 eV covering the entire visible range, which is supported by density functional theory calculations. Together with their high conductivity, matching energy levels with the work function of carbon electrodes, and excellent environmental stability, this NC displays a cathodic photocurrent density as high as 335 µA cm-2 , two orders of magnitude higher than other perovskites in aqueous solutions without the need of other electron acceptors. These combined properties suggest that the Cs2 PtBr6 NCs have great potentials in a wide range of photoelectronic and photoelectrochemical sensing applications.

On the Role of Alkali-Metal-Like Superatom Al12 P in Reduction and Conversion of Carbon Dioxide.

Developing efficient catalysts for the conversion of CO2 into fuels and value-added chemicals is of great significance to relieve the growing energy crisis and global warming. With the assistance of DFT calculations, it was found that, different from Al12 X (X=Be, Al, and C), the alkali-metal-like superatom Al12 P prefers to combine with CO2 via a bidentate double oxygen coordination, yielding a stable Al12 P(η2 -O2 C) complex containing an activated radical anion of CO2 (i.e., CO2 .- ). Thereby, this compound could not only participate in the subsequent cycloaddition reaction with propylene oxide but also initiate the radical reaction with hydrogen gas to form high-value chemicals, revealing that Al12 P can play an important role in catalyzing these conversion reactions. Considering that Al12 P has been produced in laboratory and is capable of absorbing visible light to drive the activation and transformation of CO2 , it is anticipated that this work could guide the discovery of additional superatom catalysts for CO2 transformation and open up a new research field of superatom catalysis.

On Close Parallels between the Zintl-Based Superatom Ge9Be and Chalcogen Elements.

Ever since the concept of superatoms was brought forward in the 1990s, various specific types of clusters have been proposed to mimic atomic properties and enrich the "three-dimensional periodic table". In this work, a Zintl cluster, namely, Ge9Be, has been certified eligible to join the superatom family, owing to its surprising similarity to chalcogen elements. Having 38 valence electrons, Ge9Be has an intrinsic desire to gain two additional electrons to achieve electronic shell closure, in which its quasi-chalcogen identity roots. Like oxygen-group elements, Ge9Be has the potential to form stable ionic compounds with lithium, beryllium, calcium, and superalkaline-earth atom FLi3. On the other hand, the combination of Ge9Be and the multiple valence superatom Al7- results in covalent compounds resembling carbon oxides. Close parallels have also been found between (Ge9Be)2-based compounds and common peroxides, further evidencing the superatom characteristics of Ge9Be. This finding puts forward an almost perfect superatom counterpart of group VIA elements and opens the door to characteristics-oriented design and synthesis of stable superatom motifs by utilizing solid Zintl clusters.