Substitution Effect of a Single Nitrogen Atom on π-Electronic Systems of Linear Polycyclic Aromatic Hydrocarbons (PAHs): Theoretically Visualized Coexistence of Mono- and Polycyclic π-Electron Delocalization.

We theoretically investigated the nitrogen substitution effect on the molecular structure and π-electron delocalization in linear nitrogen-substituted polycyclic aromatic hydrocarbons (N-PAHs). Based on the optimized molecular structures and magnetic field-induced parameters of fused bi- and tricyclic linear N-PAHs, we found that the local π-electron delocalization of subcycles (e.g., mono- and bicyclic constituent moieties) in linear N-PAHs is preserved, despite deviation from ideal structures of parent monocycles. The introduction of a fused five-membered ring with a pyrrolic N atom (N-5MR) in linear N-PAHs significantly perturbs the π-electronic condition of the neighboring fused six-membered ring (6MR). Monocyclic pyrrole exhibits substantial bond length alternations, strongly influencing the π-electronic systems of both the fused N-5MR and 6MR in linear N-PAHs, depending on the location of shared covalent bonds. A fused six-membered ring with a graphitic N atom in an indolizine moiety cannot generate monocyclic π-electron delocalization but instead contributes to the formation of polycyclic π-electron delocalization. This is evidenced by bifurcated diatropic ring currents induced by an external magnetic field. In conclusion, the satisfaction of Hückel's 4n + 2 rule for both mono- and polycycles is crucial for understanding the overall π-electron delocalization. It is crucial to consider the unique characteristics of the three types of substituted N atoms and the spatial arrangement of 5MR and 6MR in N-PAHs.

Facile preparation of porphyrin@g-C3N4/Ag nanocomposite for improved photocatalytic degradation of organic dyes in aqueous solution.

In the quest of improving the photocatalytic efficiency of photocatalysts, the combination of two and more semiconductors recently has garnered significant attention among scientists in the field. The doping of conductive metals is also an effective pathway to improve photocatalytic performance by avoiding electron/hole pair recombination and enhancing photon energy absorption. This work presented a design and fabrication of porphyrin@g-C3N4/Ag nanocomposite using acid-base neutralization-induced self-assembly approach from monomeric porphyrin and g-C3N4/Ag material. g-C3N4/Ag material was synthesized by a green reductant of Cleistocalyx operculatus leaf extract. Electron scanning microscopy (SEM), X-ray diffraction (XRD), FT-IR spectroscopy, and UV-vis spectrometer were utilized to analyse the properties of the prepared materials. The prepared porphyrin@g-C3N4/Ag nanocomposite showed well integration of porphyrin nanostructures on the g-C3N4/Ag's surface, in which porphyrin nanofiber was of the diameter in nanoscales and the length of several micrometers, and Ag NPs had an average particle size of less than 20 nm. The photocatalytic behavior of the resultant nanocomposite was tested for the degradation of Rhodamine B dye, which exhibited a remarkable RhB photodegrading percentage. The possible mechanism for photocatalysis of the porphyrin@g-C3N4/Ag nanocomposite toward Rhodamine B dye was also proposed and discussed.

Interfacial Engineering of Nanoporous Architectures in Ga2O3 Film toward Self-Aligned Tubular Nanostructure with an Enhanced Photocatalytic Activity on Water Splitting.

The present work demonstrates the formation of self-aligned nanoporous architecture of gallium oxide by anodization of gallium metal film controlled at -15 °C in aqueous electrolyte consisting of phosphoric acid. SEM examination of the anodized film reveals that by adding ethylene glycol to the electrolyte and optimizing the ratio of phosphoric acid and water, chemical etching at the oxide/electrolyte interfaces can be controlled, leading to the formation of aligned nanotubular oxide structures with closed bottom. XPS analysis confirms the chemical composition of the oxide film as Ga2O3. Further, XRD and SAED examination reveals that the as-synthesized nanotubular structure is amorphous, and can be crystallized to ß-Ga2O3 phase by annealing the film at 600 °C. The nanotubular structured film, when used as photoanode for photoelectrochemical splitting of water, achieved a higher photocurrent of about two folds than that of the nanoporous film, demonstrating the rewarding effect of the nanotubular structure. In addition, the work also demonstrates the formation of highly organized nonporous Ga2O3 structure on a nonconducting glass substrate coated with thin film of Ga-metal, highlighting that the current approach can be extended for the formation of self-organized nanoporous Ga2O3 thin film even on nonconducting flexible substrates.

De novo copy number variations in candidate genomic regions in patients of severe autism spectrum disorder in Vietnam.

Autism spectrum disorder (ASD) is a developmental disorder with a prevalence of around 1% children worldwide and characterized by patient behaviour (communication, social interaction, and personal development). Data on the efficacy of diagnostic tests using copy number variations (CNVs) in candidate genes in ASD is currently around 10% but it is overrepresented by patients of Caucasian background. We report here that the diagnostic success of de novo candidate CNVs in Vietnamese ASD patients is around 6%. We recruited one hundred trios (both parents and a child) where the child was clinically diagnosed with ASD while the parents were not affected. We performed genetic screening to exclude RETT syndrome and Fragile X syndrome and performed genome-wide DNA microarray (aCGH) on all probands and their parents to analyse for de novo CNVs. We detected 1708 non-redundant CNVs in 100 patients and 118 (7%) of them were de novo. Using the filter for known CNVs from the Simons Foundation Autism Research Initiative (SFARI) database, we identified six CNVs (one gain and five loss CNVs) in six patients (3 males and 3 females). Notably, 3 of our patients had a deletion involving the SHANK3 gene-which is the highest compared to previous reports. This is the first report of candidate CNVs in ASD patients from Vietnam and provides the framework for building a CNV based test as the first tier screening for clinical management.

Escalating Catalytic Activity for Hydrogen Evolution Reaction on MoSe2@Graphene Functionalization.

Developing highly efficient and durable hydrogen evolution reaction (HER) electrocatalysts is crucial for addressing the energy and environmental challenges. Among the 2D-layered chalcogenides, MoSe2 possesses superior features for HER catalysis. The van der Waals attractions and high surface energy, however, stack the MoSe2 layers, resulting in a loss of edge active catalytic sites. In addition, MoSe2 suffers from low intrinsic conductivity and weak electrical contact with active sites. To overcome the issues, this work presents a novel approach, wherein the in situ incorporated diethylene glycol solvent into the interlayers of MoSe2 during synthesis when treated thermally in an inert atmosphere at 600 °C transformed into graphene (Gr). This widened the interlayer spacing of MoSe2, thereby exposing more HER active edge sites with high conductivity offered by the incorporated Gr. The resulting MoSe2-Gr composite exhibited a significantly enhanced HER catalytic activity compared to the pristine MoSe2 in an acidic medium and demonstrated a superior HER catalytic activity compared to the state-of-the-art Pt/C catalyst, particularly at a high current density beyond ca. 55 mA cm-2. Additionally, the MoSe2-Gr catalyst demonstrated long-term electrochemical stability during HER. This work, thus, presents a facile and novel approach for obtaining an efficient MoSe2 electrocatalyst applicable in green hydrogen production.

1-D arrays of porous Mn0.21Co2.79O4 nanoneedles with an enhanced electrocatalytic activity toward the oxygen evolution reaction.

Developing effective electrocatalysts for the oxygen evolution reaction (OER) that are highly efficient, abundantly available, inexpensive, and environmentally friendly is critical to improving the overall efficiency of water splitting and the large-scale development of water splitting technologies. We, herein, introduce a facile synthetic strategy for depositing the self-supported arrays of 1D-porous nanoneedles of a manganese cobalt oxide (Mn0.21Co2.79O4: MCO) thin film demonstrating an enhanced electrocatalytic activity for OER in an alkaline electrolyte. For this, an MCO film was synthesized via thermal treatment of a hydroxycarbonate film obtained from a hydrothermal route. The deposited films were characterized through scanning electron microscopy (SEM), X-ray diffractometry (XRD), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). In contrast to a similar 1D-array of a pristine Co3O4 (CO) nanoneedle film, the MCO film exhibits a remarkably enhanced electrocatalytic performance in the OER with an 85 mV lower overpotential for the benchmark current density of 10 mA cm-2. In addition, the MCO film also demonstrates long-term electrochemical stability for the OER in 1.0 M KOH aqueous electrolyte.

Self-standing SnS nanosheet array: a bifunctional binder-free thin film catalyst for electrochemical hydrogen generation and wastewater treatment.

Hydrogen generation during wastewater treatment has remained a long-standing challenge for the environment preservation welfare. In the present work, we have fabricated a promising bifunctional thin film-based catalyst for hydrogen generation with concurrent wastewater treatment. The prepared catalyst film is a vertically oriented thin SnS (tin monosulfide) nanosheet array on a Ni-foam (SnS/NF) obtained via a solution process, demonstrating a promising electrocatalytic activity towards the generation of green H2 fuel at the cathodic side and the decomposition of urea waste at the anodic side. Notably, while assembling two identical electrodes as cathode and anode together with a reference electrode (i.e., SnS/NF∥SnS/NF vs. RHE assembly) in 1 M KOH aqueous electrolyte containing 0.33 M urea, the electrolyzer electrolyzed urea at a lower cell potential of 1.37 and 1.43 V (vs. RHE) to deliver a current density of 10 mA cm-2 and 50 mA cm-2, respectively, for the decomposition of urea at the anodic SnS/NF electrode and green hydrogen fuel generation at the cathodic SnS/NF electrode. This activity on electrocatalytic urea decomposition lies within the best performance to those of the previously reported sulfide-based and other catalytic materials. The promising catalytic activities of the SnS catalyst film are attributed to its combined effect of self-standing nanosheet array morphology and high crystallinity, which provides abundant active sites and a facile charge transfer path between the nanosheet arrays and the electrolyte. Thus, the present work offers a green avenue to the waste-urea treatment in water and sustainable hydrogen energy production.

Outcomes of bone marrow mononuclear cell transplantation combined with interventional education for autism spectrum disorder.

The aim of this study was to evaluate the safety and efficacy of autologous bone marrow mononuclear cell transplantation combined with educational intervention for children with autism spectrum disorder. An open-label clinical trial was performed from July 2017 to August 2019 at Vinmec International Hospital, Hanoi, Vietnam. Thirty children who fulfilled the autism criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and had Childhood Autism Rating Scale (CARS) scores >37 were selected. Bone marrow was harvested by anterior iliac crest puncture under general anesthesia. The volume collected was as follows: 8 mL/kg for patients under 10 kg (80 mL + [body weight in kg - 10] × 7 mL) for patients above 10 kg. Mononuclear cells were isolated with a Ficoll gradient and then infused intrathecally. The same procedure was repeated 6 months later. After the first transplantation, all patients underwent 8 weeks of educational intervention based on the Early Start Denver Model. There were no severe adverse events associated with transplantation. The severity of autism spectrum disorder (ASD) was significantly reduced, with the median CARS score decreasing from 50 (range 40-55.5) to 46.5 (range 33.5-53.5) (P < .05). Adaptive capacity increased, with the median Vineland Adaptive Behavior Scales score rising from 53.5 to 60.5. Social communication, language, and daily skills improved markedly within 18 months after transplantation. Conversely, repetitive behaviors and hyperactivity decreased remarkably. Autologous bone marrow mononuclear cell transplantation in combination with behavioral intervention was safe and well tolerated in children with ASD (Trial registration: ClinicalTrials.gov identifier: NCT03225651).

Additional knowledge respecting taxonomy of the social wasp genus Ropalidia (Hymenoptera: Vespidae: Polistinae) from Vietnam, with new records of three species and an updated key to species.

Species composition of social wasps of the genus Ropalidia from Vietnam is reported, with 24 species having been recorded. Of those, three species are newly recorded for the Vietnamese fauna, namely Ropalidia binghami van der Vecht, 1941, R. parartifex Tan van Achterberg, 2014 and R. variegata (Smith, 1852). The presence of R. sumatrae (Weber, 1801) in Vietnam is confirmed. An updated key to all recorded species of the genus Ropalidia from Vietnam is also provided.

Genetic landscape of autism spectrum disorder in Vietnamese children.

Autism spectrum disorder (ASD) is a complex disorder with an unclear aetiology and an estimated global prevalence of 1%. However, studies of ASD in the Vietnamese population are limited. Here, we first conducted whole exome sequencing (WES) of 100 children with ASD and their unaffected parents. Our stringent analysis pipeline was able to detect 18 unique variants (8 de novo and 10 ×-linked, all validated), including 12 newly discovered variants. Interestingly, a notable number of X-linked variants were detected (56%), and all of them were found in affected males but not in affected females. We uncovered 17 genes from our ASD cohort in which CHD8, DYRK1A, GRIN2B, SCN2A, OFD1 and MDB5 have been previously identified as ASD risk genes, suggesting the universal aetiology of ASD for these genes. In addition, we identified six genes that have not been previously reported in any autism database: CHM, ENPP1, IGF1, LAS1L, SYP and TBX22. Gene ontology and phenotype-genotype analysis suggested that variants in IGF1, SYP and LAS1L could plausibly confer risk for ASD. Taken together, this study adds to the genetic heterogeneity of ASD and is the first report elucidating the genetic landscape of ASD in Vietnamese children.

Effect of Substituents on the Photophysical Properties and Bioimaging Application of BODIPY Derivatives with Triphenylamine Substituents.

We investigated the intramolecular charge transfer characteristics in the S1 state of boron-dipyrromethene (BODIPY) derivatives with triphenylamine (TPA) substituents, depending on the substituted position and the number of substituents. Based on the spectroscopic and theoretical results, the ß-substitution of TPA on BODIPY hybridizes locally excited and intramolecular charge transfer characteristics in the S1 state because of strong coupling between the highest occupied molecular orbitals of BODIPY and TPA moieties, and consequently, the BODIPY derivatives with ß-substituted TPAs exhibit strong red-color fluorescence around 640 nm in nonpolar and moderately polar solvents. The TPA substituent with propeller-like nonplanar geometry could prevent H-type aggregation between neighboring BODIPY derivative units and induce aggregation-induced emission enhancement (AIEE) characteristics of the BODIPY derivatives with TPA substituents, which are helpful to maintain their emission efficiencies under highly concentrated and condensed conditions. Since the red-color emission and AIEE property of the BODIPY derivatives with ß-substituted TPAs are promising characteristics for a bioimaging application, we applied these derivatives to L-929 fibroblast cells for cellular imaging. The BODIPY derivative with a single ß-substituted TPA (compound 2) was effectively loaded into porous silica nanoparticles (SNPs). Consequently, we achieved good cellular uptake of 2-SNPs and good cellular imaging, which further confirmed the bioimaging ability of 2-SNPs.

Transformation Chlorophyll a of Spirulina platensis to Chlorin e6 Derivatives and Several Applications.

BACKGROUND: Spirulina platensis contains a large amount of chlorophylls, chlorophyll a, that are starting materials to synthesize functionalized chlorins. Chlorin e6 (Ce6) as well as its derivatives are second generation sensitizers using in photodynamic therapy (PDT) of various cancers. In this study, we transfer chlorophyll a of S. platensis to Ce6 derivatives and determine their several applications. AIM: We aimed to evaluate the effects of Ce6 derivatives to treat cancer cells. METHODS: Ce6 trimethylester was created from methyl pheophorbide a2 in S. platensis provided by the Hidumi Company, Nghe An province, Viet Nam. Hela cells were incubated with Ce6 trimethylester and the irradiated with the diode laser dose of 1.2 J/cm2/min through the system of filters £ 650 nm. MTT assay and clonogenic assay were used to determine survival rate and cloning efficiency of cells. Antimicrobial effect of Ce6 trimethylester with halogen light were studied with Propionibacterium acnes VTCC 0218 and Staphylococcus aureus VTCC 0173. RESULTS: From dry biomass (700 g) of S. platensis, after extracting chlorophyll a and methanolysis, 4.2 g of methyl pheophorbide a was obtained. The reaction to give Ce6 trimethylester with 82% yield was performed with potassium hydroxide (KOH) in MeOH/THF/CHCl3. After irradiation with a 650 nm laser at 1.2 J, the cell viability in all samples decreased with Ce6 trimethylester treatment, the survival declining trend of Hela cells treated with Ce6 trimethylester were proportional when concentration of Ce6 trimethylester increased. The rate of colony formation was declined as the concentration of Ce6 trimethylester treated was increased. The growth of both S. aureus and P. acnes can be inactivated by Ce6 trimethylester PDT. The MIC99 value against P. acnes VTCC 0218 and S. aureus VTCC 0173 of Ce6 trimethylester with halogen light was 1.25 µg/ml. CONCLUSION: The Ce6 trimethylester from S. platensis cultivated in Viet Nam could be used as a potential photosentizer for photodynamic therapy for treatment of cancer and acne.

Anodically Grown Binder-Free Nickel Hexacyanoferrate Film: Toward Efficient Water Reduction and Hexacyanoferrate Film Based Full Device for Overall Water Splitting.

One of the challenges in obtaining hydrogen economically by electrochemical water splitting is to identify and substitute cost-effective earth-abundant materials for the traditionally used precious-metal-based water-splitting electrocatalysts. Herein, we report the electrochemical formation of a thin film of nickel-based Prussian blue analogue hexacyanoferrate (Ni-HCF) through the anodization of a nickel substrate in ferricyanide electrolyte. As compared to the traditionally used Nafion-binder-based bulk film, the anodically obtained binder-free Ni-HCF film demonstrates superior performance in the electrochemical hydrogen evolution reaction (HER), which is highly competitive with that shown by a Pt-plate electrode. The HER onset and the benchmark cathodic current density of 10 mA cm-2 were achieved at small overpotentials of 15 mV and 0.2 V (not iR-corrected), respectively, in 1 M KOH electrolyte, together with the long-term electrochemical durability of the film. Further, a metal-HCF-electrode-based full water-splitting device consisting of the binder-free Ni-HCF film on a Ni plate and a one-dimensional Co-HCF film on carbon paper as the electrodes for the HER and the oxygen evolution reaction (OER), respectively, was designed and was found to demonstrate very promising performance for overall water splitting.

Novel Solid-State Solar Cell Based on Hole-Conducting MOF-Sensitizer Demonstrating Power Conversion Efficiency of 2.1.

This work reports on designing of first successful MOF-sensitizer based solid-state photovoltaic device, perticularly with a meaningful output power conversion efficiency. In this study, an intrinsically conductive cobalt-based MOFs (Co-DAPV) formed by the coordination between Co (II) ions and a redox active di(3-diaminopropyl)-viologen (i.e., DAPV) ligand is investigated as sensitizer. Hall-effect measurement shows p-type conductivity of the Co-DAPV film with hole mobility of 0.017 cm2 V-1 s-1, suggesting its potential application as hole transporting sensitizer. Further, the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of Co-DAPV are well-matched to be suitably employed for sensitizing TiO2. Thus, by layer-by-layer deposition of hole conducting MOF-sensitizer onto mesoporous TiO2 film, a power conversion efficiency of as high as 2.1% is achieved, which exceeds the highest efficiency values of MOF-sensitized liquid-junction solar cells reported so far.

Interfacial Engineering for Enhanced Light Absorption and Charge Transfer of a Solution-Processed Bulk Heterojunction Based on Heptazole as a Small Molecule Type of Donor.

In the present study, a solution-processed organic semiconductor based on indolocarbazole derivative (heptazole) is introduced as a p-type donor material for a bulk-heterojunction photovoltaic device. The heptazole has an optical band gap of 2.97 eV, and its highest occupied molecular orbital-lowest unoccupied molecular orbital energy levels are compactable with the PC60BM to construct a donor-acceptor heterojuction for energy harvesting and transfer. When the bulk-heterojunction photovoltaic devices consisting of ITO/PEDOT:PSS/heptazole:PC60BM/Al with different blending ratio of heptazole:PC60BM were constructed, the cell with 1:1 blending ratio exhibited the best power conversion efficiency. Further, when an indoline organic dye (D149) was introduced as an interfacial modifier to the above donor/acceptor bulk heterojunction, the device demonstrated an enhanced overall power conversion efficiency from 1.26% to 2.51% hence demonstrating enhancement by the factor of 100%. The device was further characterized using electronic absorption spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy, and the photovoltage decay kinetics. These studies reveal that the enhanced power conversion efficiency of the device is due to the enhanced charge transfer with the complementary light absorption feature of the interfacial D149 dye molecules.