The uS10c-BPG2 module mediates ribosomal RNA processing in chloroplast nucleoids.

In plant chloroplasts, certain ribosomal proteins (RPs) and ribosome biogenesis factors (RBFs) are present in nucleoids, implying an association between nucleoids and ribosome biogenesis. In Arabidopsis, the YqeH-type GTPase Brassinazole-Insensitive Pale Green2 (BPG2) is a chloroplast nucleoid-associated RBF. Here, we investigated the relationship between nucleoids and BPG2-involved ribosome biogenesis steps by exploring how BPG2 targets ribosomes. Our findings demonstrate that BPG2 interacts with an essential plastid RP, uS10c, in chloroplast nucleoids in a ribosomal RNA (rRNA)-independent manner. We also discovered that uS10c is a haploinsufficient gene, as the heterozygous deletion of this gene leads to variegated shoots and chlorophyll aggregation. uS10c is integrated into 30S ribosomal particles when rRNA is relatively exposed and also exists in polysome fractions. In contrast, BPG2 exclusively associates with 30S ribosomal particles. Notably, the interaction between BPG2 and 30S particles is influenced by the absence of uS10c, resulting in BPG2 diffusing in chloroplasts instead of targeting nucleoids. Further, our results reveal that the loss of BPG2 function and the heterozygous deletion of uS10c impair the processing of 16S and 23S-4.5S rRNAs, reduce plastid protein accumulation, and trigger the plastid signaling response. Together, these findings indicate that the uS10c-BPG2 module mediates ribosome biogenesis in chloroplast nucleoids.

Comprehensive analysis of genomic complexity in the 5' end coding region of the DMD gene in patients of exons 1-2 duplications based on long-read sequencing.

BACKGROUND: Dystrophinopathies are the most common X-linked inherited muscle diseases, and the disease-causing gene is DMD. Exonic duplications are a common type of pathogenic variants in the DMD gene, however, 5' end exonic duplications containing exon 1 are less common. When assessing the pathogenicity of exonic duplications in the DMD gene, consideration must be given to their impact on the reading frame. Traditional molecular methods, such as multiplex ligation-dependent probe amplification (MLPA) and next-generation sequencing (NGS), are commonly used in clinics. However, they cannot discriminate the precise physical locations of breakpoints and structural features of genomic rearrangement. Long-read sequencing (LRS) can effectively overcome this limitation. RESULTS: We used LRS technology to perform whole genome sequencing on three families and analyze the structural variations of the DMD gene, which involves the duplications of exon 1 and/or exon 2. Two distinct variant types encompassing exon 1 in the DMD Dp427m isoform and/or Dp427c isoform are identified, which have been infrequently reported previously. In pedigree 1, the male individuals harboring duplication variant of consecutive exons 1-2 in the DMD canonical transcript (Dp427m) and exon 1 in the Dp427c transcript are normal, indicating the variant is likely benign. In pedigree 3, the patient carries complex SVs involving exon 1 of the DMD Dp427c transcript showing an obvious phenotype. The locations of the breakpoints and the characteristics of structural variants (SVs) are identified by LRS, enabling the classification of the variants' pathogenicity. CONCLUSIONS: Our research sheds light on the complexity of DMD variants encompassing Dp427c/Dp427m promoter regions and emphasizes the importance of cautious interpretation when assessing the pathogenicity of DMD 5' end exonic duplications, particularly in carrier screening scenarios without an affected proband.

[Intracytoplasmic sperm injection for patients with special types of teratozoospermia: Analysis of outcomes].

OBJECTIVE: To investigate the outcomes of intracytoplasmic sperm injection (ICSI) in the treatment of special types of teratozoospermia such as globozoospermia, acephalic spermatozoa syndrome (ASS) and multiple morphological abnormalities of sperm flagella (MMAF). METHODS: We retrospectively analyzed the clinical data on 7 cases of globozoospermia (group A), 6 cases of ASS (group B) and 21 cases of MMAF (group C) treated by ICSI from January 2011 to January 2021, all confirmed with pathogenic or likely pathogenic gene variations. We compared the age, body mass index (BMI), sperm parameters, number of mature oocytes, and rates of fertilization, high-quality embryos, clinical pregnancy, live birth and spontaneous abortion among the three groups of patients. RESULTS: There were no statistically significant differences in the age, BMI and number of metaphase Ⅱ (MⅡ) oocytes among the three groups (P > 0.05). Sperm concentration and motility were dramatically higher (P < 0.01) while the rates of fertilization, clinical pregnancy and live birth remarkably lower in group A than in B and C (P < 0.01). No statistically significant difference was observed in the spontaneous abortion rate among the three groups (P > 0.05). CONCLUSION: ICSI can achieve relatively satisfactory outcomes of clinical pregnancy in patients with ASS or MMAF, but only a low fertilization rate or no fertilization at all in those with globozoospermia even if treated by artificial oocyte activation.

RAB GTPASE HOMOLOG 8D is required for the maintenance of both the root stem cell niche and the meristem.

Previous studies have suggested that the plastid translation elongation factor, elongation factor thermo unstable (EF-Tu), encoded by RAB GTPASE HOMOLOG 8D (RAB8D) is essential for plant growth. Here, through analyzing the root phenotypes of two knock-down alleles of RAB8D (rab8d-1 and rab8d-2), we further revealed a vital role for RAB8D in primary root development through the maintenance of both the stem cell niche (SCN) and the meristem. Our results showed that RAB8D deficiency affects the root auxin response and SCN maintenance signaling. RAB8D interacts with GENOMES UNCOUPLED 1 (GUN1) in vivo. Further analysis revealed that GUN1 is over-accumulated and is required for both stem cell death and maintenance of root architecture in rab8d Arabidopsis mutants. The ATAXIA-TELANGIECTASIA-MUTATED (ATM)-SUPPRESSOR OF GAMMA RESPONSE 1 pathway is involved in the regulation of root meristem size through upregulating SIAMESE-RELATED 5 expression in the rab8d-2 allele. Moreover, ETHYLENE RESPONSE FACTOR 115 is highly expressed in rab8d-2, which plays a role in further quiescent center division. Our observations not only characterized the role of RAB8D in root development, but also uncovered functions of GUN1 and ATM in response to plastid EF-Tu deficiency.

[Analysis of three Chinese pedigrees affected with recurrent hydatidiform mole due to variants of NLRP7 gene].

OBJECTIVE: To explore the genetic etiology of recurrent hydatidiform mole (RHM) and provide accurate guidance for reproduction. METHODS: Peripheral venous blood samples of the probands with RHM and members from 5 unrelated pedigrees were collected. Genomic DNA was extracted by using routine method, and whole exome sequencing was carried out to detect variants of RHM-associated genes including NLRP7 and KHDC3L. Sanger sequencing and real-time quantitative PCR (RT-qPCR) were used to validate the candidate variants and delineate their parental origin. RESULTS: Homozygous or compound heterozygous variants of the NLRP7 gene were identified in four patients from three pedigrees, which included a homozygous deletion of exon 1 to 4 of NLRP7 in patient P1 and her elder sister, compound heterozygous variants of NLRP7 c.939delG (p.Q314Sfs*6) pat and c.1533delG (p.N512Tfs*4) mat in patient P2, and compound heterozygous variants of NLRP7 c.2389_2390delTC (p.A798Qfs*6) pat and c.2165A>G (p.D722G) mat in patient P4. All variants were interpreted as pathogenic or likely pathogenic according to the American College of Medical and Genomics (ACMG) guidelines. Among these, NLRP7 exons 1 to 4 deletion, c.939delG (p.Q314Sfs*6), c.1533delG (p.N512Tfs*4) and c.2389_2390delTC (p.A798Qfs*6) were unreported previously. CONCLUSION: Variants of the NLRP7 gene probably underlay autosomal recessive RHM in the three pedigrees, and definitive molecular diagnosis is beneficial for accurate genetic counseling. Above finding has also enriched the spectrum of the NLRP7 variants underlying RHM.

Novel bi-allelic variants in ACTL7A are associated with male infertility and total fertilization failure.

STUDY QUESTION: What are the genetic causes of total fertilization failure (TFF) in a proband suffering from male infertility? SUMMARY ANSWER: Novel compound heterozygous variants (c.[463C>T];[1084G>A], p.[(Arg155Ter)];[(Gly362Arg)]) in actin-like protein 7A (ACTL7A) were identified as a causative genetic factor for human TFF. WHAT IS KNOWN ALREADY: ACTL7A, an actin-related protein, is essential for spermatogenesis. ACTL7A variants have been reported to cause early embryonic arrest in humans but have not been studied in human TFF. STUDY DESIGN, SIZE, DURATION: We recruited a non-consanguineous family whose son was affected by infertility characterized by TFF after ICSI. Whole-exome sequencing was used to identify the potential pathogenic variants. Artificial oocyte activation (AOA) after ICSI was performed to overcome TFF and any resulting pregnancy was followed up. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sanger sequencing was performed to validate the variants. Pathogenicity of the identified variants was predicted by in silico tools. The ultrastructure of spermatozoa was studied by transmission electron microscopy (TEM). Immunofluorescence staining and western blotting were used to investigate the mechanism of the variants on the affected spermatozoa. MAIN RESULTS AND THE ROLE OF CHANCE: Novel compound heterozygous variants in ACTL7A (c.[463C>T];[1084G>A], p.[(Arg155Ter)];[(Gly362Arg)]) were identified in a family with TFF after ICSI. In silico analysis predicted that the variants lead to a disease-causing protein. TEM showed that the ACTL7A variants caused ultrastructural defects in the acrosome and perinuclear theca. Protein expression of ACTL7A and phospholipase C zeta, a key sperm-borne oocyte activation factor, was significantly reduced in the affected sperm compared to healthy controls, suggesting that the ACLT7A variants lead to an oocyte activation deficiency and TFF. AOA by calcium ionophore (A23187) after ICSI successfully rescued the TFF and achieved a live birth for the patient with ACTL7A variants. LIMITATIONS, REASONS FOR CAUTION: Given the rarity of sperm-associated TFF, only one family with an only child carrying the ACTL7A variants was found. In addition, the TFF phenotype was not assessed in two or more ICSI cycles, due to the intervention in ICSI with AOA after one failed ICSI cycle. Further studies should validate the ACTL7A variants and its effect on male infertility in larger independent cohorts. WIDER IMPLICATIONS OF THE FINDINGS: : Our findings revealed a critical role of ACTL7A in male fertility and identified bi-allelic variants in ACTL7A associated with human TFF, which expands the genetic spectrum of TFF and supports the genetic diagnosis of TFF patients. We also rescued TFF by AOA and obtained a healthy live birth, which provides a potentially effective intervention for patients with ACTL7A pathogenic variants. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Natural Science Foundation of China (81971374 and 81401267). No conflicts of interest were declared. TRIAL REGISTRATION NUMBER: N/A.

Coordination between MIDASIN 1-mediated ribosome biogenesis and auxin modulates plant development.

Ribosomes are required for plant growth and development, and ribosome biogenesis-deficient mutants generally display auxin-related phenotypes. Although the relationship between ribosome dysfunction and auxin is known, many aspects of this subject remain to be understood. We previously reported that MIDASIN 1 (MDN1) is an essential pre-60S ribosome biogenesis factor (RBF) in Arabidopsis. In this study, we further characterized the aberrant auxin-related phenotypes of mdn1-1, a weak mutant allele of MDN1. Auxin response is disturbed in both shoots and roots of mdn1-1, as indicated by the DR5:GUS reporter. By combining transcriptome profiling analysis and reporter gene detection, we found that expression of genes involved in auxin biosynthesis, transport, and signaling is changed in mdn1-1. Furthermore, MDN1 deficiency affects the post-transcriptional regulation and protein distribution of PIN-FORMED 2 (PIN2, an auxin efflux facilitator) in mdn1-1 roots. These results indicate that MDN1 is required for maintaining the auxin system. More interestingly, MDN1 is an auxin-responsive gene, and its promoter can be targeted by multiple AUXIN RESPONSE FACTORs (ARFs), including ARF7 and ARF19, in vitro. Indeed, in arf7 arf19, the auxin sensitivity of MDN1 expression is significantly reduced. Together, our results reveal a coordination mechanism between auxin and MDN1-dependent ribosome biogenesis for regulating plant development.

Genetic etiologic analysis in 74 Chinese Han women with idiopathic premature ovarian insufficiency by combined molecular genetic testing.

PURPOSE: To identify the disease-causing genes of Chinese Han women with idiopathic premature ovarian insufficiency (POI). METHODS: Seventy-four Chinese Han women with idiopathic POI were collected to analyze the genetic etiology. Triplet repeat-primed polymerase chain reaction (TP-PCR) was performed to screen the FMR1 (CGG)n premutation, and then 60 POI-related genes were sequenced by targeted next-generation sequencing (NGS) in POI patients with normal FMR1. RESULTS: A total of one patient (1/74) with FMR1 premutation was identified. Targeted NGS revealed that 15.07% (11/73) patients had pathogenic or likely pathogenic variants of Mendelian genes (FOXL2, EIF2B2, CYP17A1, CLPP, MCM9, GDF9, MSH5, ERCC6, POLG). Ten novel variants in six Mendelian genes were identified, such as CLPP c.355A>C (p.I119L) and c.688A>C (p.M230L), MCM9 c.1157C>T (p.T386M) and c.1291A>G (p.M431V), GDF9 c. 238C>T (p.Q80X), MSH5 c.604G>C (p.G202R) and c.2063T>C (p.I688T), ERCC6 c.C1769C>T (p.P590L), POLG c.2832G>C (p.E944D), and c.2821A>G (p.I941V). CONCLUSION: This study suggested targeted NGS was an efficient etiologic test for idiopathic POI patients without FMR1 premutation and enriched the variant spectrum of POI-related genes.

A novel homozygous nonsense mutation in zona pellucida 1 (ZP1) causes human female empty follicle syndrome.

PURPOSE: To identify a pathogenic gene mutation in a female infertility proband characterized by empty follicle syndrome (EFS) and explore the genetic cause of EFS. METHODS: Whole exome sequencing (WES) was performed to identify the candidate pathogenic mutation. Sanger sequencing was used to validate the mutation in family members. The pathogenicity of the identified variant and its possible effects on the protein were evaluated with in silico tools. Immunofluorescence staining was used to study the possible mechanism of the mutation on affected oocyte. RESULTS: We identified a family with a novel homozygous nonsense mutation in zona pellucida 1 (ZP1) (c.199G > T [p.Glu67Ter]). Based on bioinformatics analysis, the mutation was predicted to be pathogenic. This variant generates a premature stop codon in exon 2 at the 199th nucleotide, and was inferred to result in a truncated ZP1 protein of 67 amino acids at the ZP-N1 domain. An in vitro study showed that the oocyte of the EFS proband was degenerated and the zona pellucida was absent. Additionally, the mutant ZP1 proteins were localized in the cytoplasm of the degenerated oocyte but not at the surface. CONCLUSIONS: The novel mutation in ZP1 is a genetic cause of female infertility characterized by EFS. Our finding expands the genetic spectrum for EFS and will help justify the EFS diagnosis in patients.

Chirality Detection by Raman Spectroscopy: The Case of Enantioselective Interactions between Amino Acids and Polymer-Modified Chiral Silica.

In chirality research area, it is of interest to reveal the chiral feature of inorganic nanomaterials and their enantioselective interactions with biomolecules. Although common Raman spectroscopy is not regarded as a direct chirality analysis tool, it is in fact effective and sensitive to study the enantioselectivity phenomena, which is demonstrated by the enantio-discrimination of amino acid enantiomers using the polydopamine-modified intrinsically chiral SiO2 nanofibers in this work. The Raman scattering intensities of an enantiomer of cysteine are more than twice as high as those of the other enantiomer with opposite handedness. Similar results were also found in the cases of cystine, phenylalanine, and tryptophan enantiomers. In turn, these organic molecules could be used as chirality indicators for SiO2, which was clarified by the unique Raman spectra-derived mirror-image relationships. Thus, an indirect chirality detection method for inorganic nanomaterials was developed.

Chiral Plasmonic Nanoparticle Assisted Raman Enantioselective Recognition.

Au nanoparticles (NPs) labeled with the handedness tag of "d-" or "l-", which were detached from inorganic chiral silica, showed both intrinsic chirality and surface enhanced Raman scattering (SERS) activity. In the presence of these chiral Au substrates, it was found that the enantiomer of cystine with the same handedness tag of Au NPs would show stronger Raman scattering signal intensities than those of the enantiomer with the opposite tag, where the differences could be over three times. Consequently, this work afforded a novel enantioselective recognition method on ordinary Raman spectroscopy by using chiral plasmonic metallic nanomaterials.

Atomic-Level Fe-N-C Coupled with Fe3 C-Fe Nanocomposites in Carbon Matrixes as High-Efficiency Bifunctional Oxygen Catalysts.

Highly active and durable bifunctional oxygen electrocatalysts are of pivotal importance for clean and renewable energy conversion devices, but the lack of earth-abundant electrocatalysts to improve the intrinsic sluggish kinetic process of oxygen reduction/evolution reactions (ORR/OER) is still a challenge. Fe-N-C catalysts with abundant natural merits are considered as promising alternatives to noble-based catalysts, yet further improvements are urgently needed because of their poor stability and unclear catalytic mechanism. Here, an atomic-level Fe-N-C electrocatalyst coupled with low crystalline Fe3 C-Fe nanocomposite in 3D carbon matrix (Fe-SAs/Fe3 C-Fe@NC) is fabricated by a facile and scalable method. Versus atomically FeNx species and crystallized Fe3 C-Fe nanoparticles, Fe-SAs/Fe3 C-Fe@NC catalyst, abundant in vertical branched carbon nanotubes decorated on intertwined carbon nanofibers, exhibits high electrocatalytic activities and excellent stabilities both in ORR (E1/2 , 0.927 V) and OER (EJ=10 , 1.57 V). This performance benefits from the strong synergistic effects of multicomponents and the unique structural advantages. In-depth X-ray absorption fine structure analysis and density functional theory calculation further demonstrate that more extra charges derived from modified Fe clusters decisively promote the ORR/OER performance for atomically FeN4 configurations by enhanced oxygen adsorption energy. These insightful findings inspire new perspectives for the rational design and synthesis of economical-practical bifunctional oxygen electrocatalysts.

Homozygous missense mutation Arg207Cys in the WEE2 gene causes female infertility and fertilization failure.

PURPOSE: To investigate a novel mutation in the WEE2 gene in a female patient with primary infertility and fertilization failure. METHODS: Sanger sequencing was used to detect mutations in WEE2. The pathogenicity of the identified variant and its possible effects on the WEE2 protein were evaluated with in silico tools and molecular modeling. We used the calcium ionophore A23187 as a chemical activator of oocytes after intracytoplasmic sperm injection (ICSI). RESULTS: We identified a consanguineous family with a novel homozygous missense mutation in WEE2 (c.619C>T [p.R207C]). Based on preliminary bioinformatics analysis, we speculate that the novel homozygous missense mutation is pathogenic. ICSI combined with assisted oocyte activation (ICSI-AOA) did not overcome fertilization failure in this patient with WEE2 mutation. CONCLUSIONS: We identified a novel mutation in WEE2 (c.619C>T [p.R207C]) in a female patient with fertilization failure after ICSI, and we provide evidence that this novel homozygous missense mutation can cause fertilization failure.

Surface Acoustic Wave Gyroscopic Effect in an Interdigital Transducer.

The surface acoustic wave (SAW) gyroscopic effect in an interdigital transducer (IDT) deposited on a piezoelectric substrate is different from that in the piezoelectric substrate due to a reflection induced by IDT. In this work, an extended coupling-of-mode (COM) model including the gyroscopic effect and the reflection was developed to analyze the SAW gyroscopic effect. First, dispersion characteristics parameters of SAW were fitted according to the data derived using the finite element method (FEM). Then, variations of stop band edge frequency were calculated using the extended COM theory by integrating dispersion characteristics parameters into the COM model. We compared its results with those obtained via FEM analysis to confirm the proposed model's validity. We found that the variation in stop band edge frequency related to gyroscope effect reached the maximum value with a zero reflectivity value. For split IDT, the sensitivity of gyroscope effect is 0.036 Hz/rad/s with a lower than 1% normalized thickness. Conversely, the value of sensitivity was almost zero for bidirectional IDT and electrode width controlled single-phase unidirectional transducer (EWC/SPUDT).

[Differentiation of embryonic stem cells from the embryos of the couples with male asthenozoospermia and Robertsonian translocation into germ cells].

OBJECTIVE: To assess the risk of male infertility in the offspring conceived through assisted reproductive technology (ART) byin vitroinductionof the differentiation of embryonic stem cells (ESCs) derived from the embryos of the couples with male asthenozoospermia and Robertsonian translocation (RT) into germ cells. METHODS: We established a CCRM16ESC line with the karyotype of 46, XY, +14, rob(13; 14) (q10; q10) from the embryo donated by a patientwithasthenozoospermiaand RT and his wife by isolation of the inner cell mass of blastula, culturing, passaging, and amplification,followed by in vitro induction and differentiationof the ESCs into germ cells with ratinoic acid(RA) at 2 mol/L. Then, we analyzed the process of differentiation and the expressions of its related genes and compared them with those in the normal CCRM23ESCs. RESULTS: CCRM16 showed the typical characteristics of ESCs, expressing the pluripotency makers of NANOG, OCT4, TRA-1-181 and SSEA4, forming embryoid bodies, and differentiating into three germlayer tissues in vitro and in vivo. Intervention with 2 mol/LRAinduced direct differentiation of the ESCs into germ cells. The expressions of the primordial germ cell marker geneDAZLand the meiosis marker geneSCP3were markedly decreased in the CCRM16 as compared with those in the normal CCRM23 ESCs. CONCLUSIONS: The CCRM16ESC linewith the karyotype of46, XY, +14, rob(13; 14) (q10; q10) has thetypical characteristics of ESCs but an abnormal process of differentiation into germ cells in the early stage. In vitroinductionof the differentiation of ESCs into germ cells can be used for assessing the risk of male infertility in the offspring conceived through ART for asthenozoospermia patients.

[A retrospective analysis of 6 children with Duchenne muscular dystrophy].

OBJECTIVE: To analyze the clinical features of 6 children with Duchenne muscular dystrophy (DMD) and review related literature, and to provide a basis for early diagnosis and effective treatment of this disease. METHODS: A retrospective analysis was performed on the clinical data of 6 children with DMD who were admitted to the First Affiliated Hospital of Nanjing Medical University from January 2010 to October 2015. RESULTS: All the 6 cases were boys without a family history of DMD, and the age of diagnosis of DMD was 1.2-11.5 years. All patients had insidious onset and increases in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, α-hydroxybutyrate dehydrogenase, creatine kinase (CK), and creatine kinase-MB, particularly CK, which was 3.3-107.2 times the normal level. Their gene detection results all showed DMD gene mutation. The gene detection results of two children's mothers showed that they carried the same mutant gene. The muscle biopsy in one case showed that the pathological changes confirmed the diagnosis of DMD. The level of CK in one case declined by 77.0% 5 days after umbilical cord blood mesenchymal stem cell transplantation. CONCLUSIONS: For boys with abnormal serum enzyme levels and motor function, DMD should be highly suspected. It should be confirmed by CK and DMD gene detection as soon as possible. And the progression of the disease could be delayed by early intervention for protecting the remaining normal muscle fibers.

Sequestration of Antimonite by Zerovalent Iron: Using Weak Magnetic Field Effects to Enhance Performance and Characterize Reaction Mechanisms.

Many oxyanion-forming metals (As, Sb, Se, Tc, etc.) can be removed from water by adsorption and/or redox reactions involving iron oxides, including the oxides associated with zerovalent iron (ZVI). The rate of antimonite (Sb(III) hydrolysis species) removal by ZVI was determined in open, well-mixed batch reactors as a function of experimental factors, including aging of the ZVI, addition of Fe(II), Sb dose, mixing rate, pH, initial concentrations of Sb(III), etc. However, the largest effect observed was the roughly 6-8 fold increase in Sb(III) removal rate due to the application of a weak magnetic field (WMF) during the experiments. The WMF effect on Sb removal arises from stimulated corrosion and delayed passivation of the ZVI, as evidenced by time series correlation analysis of "geochemical" properties (DO, Fetot, Eh, and pH) measured synchronously in each experiment. The removal of Sb under the conditions of this study was mainly due to oxidation of Sb(III) to Sb(V) and adsorption and coprecipitation onto the iron oxides formed from accelerated corrosion of ZVI, as evidenced by Sb K-edge XANES, EXAFS, and XPS. The degree of the WMF enhancement for Sb(III) was found to be similar to the WMF effect reported previously for Sb(V), As(III), As(V), and Se(VI).

C and N Hybrid Coordination Derived Co-C-N Complex as a Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction.

Development of an efficient hydrogen evolution reaction (HER) catalyst composed of earth-abundant elements is scientifically and technologically important for the water splitting associated with the conversion and storage of renewable energy. Herein we report a new class of Co-C-N complex bonded carbon (only 0.22 at% Co) for HER with a self-supported and three-dimensional porous structure that shows an unexpected catalytic activity with low overpotential (212 mV at 100 mA cm(-2)) and long-term stability, better than that of most traditional-metal catalysts. Experimental observations in combination with density functional theory calculations reveal that C and N hybrid coordination optimizes the charge distribution and enhances the electron transfer, which synergistically promotes the proton adsorption and reduction kinetics.

Antibacterial Δ(1) -3-ketosteroids from the South China Sea gorgonian coral Subergorgia rubra.

Three new Δ(1) -3-ketosteroids characterized with a 9-OH, subergosterones A-C (1-3), together with five known analogs 4-8, were obtained from the gorgonian coral Subergorgia rubra collected from the South China Sea. The structures of 1-3, including their absolute configurations, were determined by comprehensive spectroscopic methods and electronic circular dichroism (ECD) experiments. Compounds 2 and 3 exhibited inhibitory antibacterial activities against Bacillus cereus with MIC values of 1.56 µM.

Stabilization of Palladium Nanoparticles on Nanodiamond-Graphene Core-Shell Supports for CO Oxidation.

Nanodiamond-graphene core-shell materials have several unique properties compared with purely sp(2) -bonded nanocarbons and perform remarkably well as metal-free catalysts. In this work, we report that palladium nanoparticles supported on nanodiamond-graphene core-shell materials (Pd/ND@G) exhibit superior catalytic activity in CO oxidation compared to Pd NPs supported on an sp(2) -bonded onion-like carbon (Pd/OLC) material. Characterization revealed that the Pd NPs in Pd/ND@G have a special morphology with reduced crystallinity and are more stable towards sintering at high temperature than the Pd NPs in Pd/OLC. The electronic structure of Pd is changed in Pd/ND@G, resulting in weak CO chemisorption on the Pd NPs. Our work indicates that strong metal-support interactions can be achieved on a non-reducible support, as exemplified for nanocarbon, by carefully tuning the surface structure of the support, thus providing a good example for designing a high-performance nanostructured catalyst.