Rational Design of Nanocatalysts with Nonmetal Species Modification for Electrochemical CO2 Reduction

Converting CO₂ to valuable carbonaceous fuels and chemicals via electrochemical CO₂ reduction by using renewable energy sources is considered to be a scalable strategy with substantial environmental and economic benefits. One of the challenges in this field is to develop nanocatalysts with superior electrocatalytic activity and selectivity for targeted products. Nonmetal species modification of nanocatalysts is of great significance for the construction of distinctive active sites to overcome the kinetic limitations of CO₂ reduction. These types of modification enable the efficient control of the selectivity and significantly decrease the reaction overpotential. Herein, a comprehensive review of the recent progress of nonmetal species modification of nanocatalysts for electrochemical CO₂ reduction is presented. After discussing some fundamental parameters and the basic principles of CO₂ reduction, including possible reaction pathways in light of theoretical modeling and experiments, the identification of active sites and elucidation of reaction mechanisms are emphasized for unraveling the role of nonmetal species modification, such as heteroatom incorporation, organic molecule decoration, electrolyte engineering, and single‐atom engineering. In the final section, future challenges and constructive perspectives are provided, facilitating the accelerated advancement of mechanism research and practical applications of green carbon cycling.     

De novo genome assembly of Candida glabrata reveals cell wall protein complement and structure of dispersed tandem repeat arrays

Candida glabratais an opportunistic pathogen in humans, responsible for approximately 20% of disseminated candidiasis. Candida glabrata's ability to adhere to host tissue is mediated by GPI-anchored cell wall proteins (GPI-CWPs); the corresponding genes contain long tandem repeat regions. These repeat regions resulted in assembly errors in the reference genome. Here, we performed a de novo assembly of the C. glabrata type strain CBS138 using long single-molecule real-time reads, with short read sequences (Illumina) for refinement, and constructed telomere-to-telomere assemblies of all 13 chromosomes. Our assembly has excellent agreement overall with the current reference genome, but we made substantial corrections within tandem repeat regions. Specifically, we removed 62 genes of which 45 were scrambled due to misassembly in the reference. We annotated 31 novel ORFs of which 24 ORFs are GPI-CWPs. In addition, we corrected the tandem repeat structure of an additional 21 genes. Our corrections to the genome were substantial, with the length of new genes and tandem repeat corrections amounting to approximately 3.8% of the ORFeome length. As most corrections were within the coding regions of GPI-CWP genes, our genome assembly establishes a high-quality reference set of genes and repeat structures for the functional analysis of these cell surface proteins.     

3D Porous Pyramid Heterostructure Array Realizing Efficient Photo‐Electrochemical Performance

Direct photo‐electrochemical (PEC) water splitting is of great practical interest for developing a sustainable energy systems, but remains a big challenge owing to sluggish charge separation, low efficiency, and poor stability. Herein, a 3D porous In₂O₃/In₂S₃ pyramid heterostructure array on a fluorine‐doped tin oxide substrate is fabricated by an ion exchange–induced synthesis strategy. Based on the synergistic structural and electronic modulations from density functional theory calculations and experimental observations, 3D porous In₂O₃/In₂S₃ photoanode by the protective layer delivers a low onset potential of ≈0.02 V versus reversible hydrogen electrode (RHE), the highest photocurrent density of 8.2 mA cm^?2 at 1.23 V versus RHE among all the In₂S₃ photoanodes reported to date, an incident photon‐to‐current efficiency of 76% at 400 nm, and high stability over 20 h for PEC water splitting are reported. This work provides an alternative promising prototype for the design and construction of novel heterostructures in robust PEC water splitting applications.     

Electrochemical treatment of graphite to enhance electron transfer from bacteria to electrodes

In this paper, graphite felts were continuously electrochemically oxidized to increase the current generation in microbial fuel cells (MFCs). The treated and untreated graphite felts were utilized as anodes in MFCs and current production was compared. The current production on electrochemically treated graphite felt anodes was about 1.13 mA, 39.5% higher compared with that of MFCs containing untreated anodes. The results demonstrated that the electronic coupling between graphite felt electrodes and electrogenic bacteria could be enhanced by electrochemical oxidization of the electrodes. Further study showed that the newly generated carboxyl containing functional groups from electrochemical oxidization were responsible for the enhanced electron transfer, due to their strong hydrogen bonding with peptide bonds in bacterial cytochromes.     

HLA-A2 and B35 Restricted Hantaan Virus Nucleoprotein CD8+ T-Cell Epitope-Specific Immune Response Correlates with Milder Disease in Hemorrhagic Fever with Renal Syndrome

Background

Hantaan virus (HTNV) infection in humans is a serious public health concern in Asia. A potent T cell activation peptide vaccine from HTNV structure protein represents a promising immunotherapy for disease control. However, the T cell epitopes of the HTNV restricted by the HLA alleles and the role of epitope-specific T cell response after HTNV infection remain largely unexplored.

Methodology/Principal Findings

Five well-conserved novel CD8⁺ T-cell epitopes of the HTNV nucleoprotein restricted by the most popular HLA alleles in Chinese Han population were defined with interferon-γ enzyme-linked immunospot assay in 37 patients infected with HTNV during hospitalization. Two epitopes aa129–aa137 and aa131–aa139 restricted by HLA-A2 and B35, respectively, were selected to evaluate the epitope-specific CD8⁺ T-cell response. HLA-peptide pentamer complex staining showed that the frequency of single epitope-specific CD8⁺ T cell could be detected in patients (95% confidence interval for aa129–aa137: 0.080%–0.208%; for aa131–aa139: 0.030%–0.094%). The frequency of epitope-specific pentamer⁺ CD8⁺ T-cell response was much higher in mild/moderate patients than in severe/critical ones at the acute stage of the disease. Moreover, the frequency of epitope-specific CD8⁺ T cells at acute stage was inversely associated with the peak level of serum creatinine and was positively associated with the nadir platelet counts during the hospitalization. The intracellular cytokine staining and the proliferation assay showed that the effective epitope-specific CD8⁺ T cells were characterized with the production of interferon-γ, expression of CD69 and the strong capacity of proliferation.

Conclusion/Significance

The novel HLA class I restricted HTNV nucleoprotein epitopes-specific CD8⁺ T-cell responses would be closely related with the progression and the severity of the disease, which could provide the first step toward effective peptide vaccine development against HTNV infection in humans.     

Power production enhancement with a polyaniline modified anode in microbial fuel cells

In this paper, an approach of improving power generation of microbial fuel cells (MFCs) by using a HSO(4)(-) doped polyaniline modified carbon cloth anode was reported. The modification of carbon cloth anode was accomplished by electrochemical polymerization of aniline in 5% H(2)SO(4) solution. A dual-chamber MFC reactor with the modified anode achieved a maximum power density of 5.16 Wm(-3), an internal resistance of 90 Ω, and a start-up time of 4 days, which was respectively 2.66 times higher, 65.5% lower, and 33.3% shorter than the corresponding values of the MFC with unmodified anode. Evidence from X-ray photoelectron spectroscopy and scanning electron microscopy results proved that the formation of biofilm on the anode surface could prevent the HSO(4)(-) doped polyaniline to be de-doped, and the results from electrochemical tests confirmed that the electrochemical activity of the modified anode was enhanced significantly after inoculation. Charge transfer was facilitated by polyaniline modification. All the results indicated that the polyaniline modification on the anode was an efficient approach of improving the performance of MFCs.     

Anterior Insula GABA Levels Correlate with Emotional Aspects of Empathy: A Proton Magnetic Resonance Spectroscopy Study

Background:

Empathy is a multidimensional construct referring to the capacity to understand and share the emotional and affective states of another person. Cerebral γ-aminobutyric acid (GABA)-ergic levels are associated with a variety of neurological and psychiatric disorders. However, the role of the GABA system in different dimensions of empathy has not been investigated.

Materials and Methods:

Thirty-two right-handed healthy volunteers took part in this study. We used proton magnetic resonance spectroscopy to determine GABA concentrations in the anterior insula (AI) and the anterior cingulate cortex (ACC) and to examine the relationship between the GABA concentrations and the subcomponents of empathy evaluated by the Interpersonal Reactivity Index (IRI).

Result:

Pearson correlation analyses (two-tailed) showed that AI GABA was significantly associated with the empathy concern score (r = 0.584, p<0.05) and the personal distress score (r = 0.538, p<0.05) but not significantly associated with other empathy subscales. No significant correlation was found between ACC GABA and empathy subscores.

Conclusion:

Left AI GABA was positively correlated with the emotional aspects of empathy. These preliminary findings call into question whether AI GABA alterations might predict empathy dysfunction in major psychiatric disorders such as autism and schizophrenia, which have been described as deficits in emotional empathic abilities.     

Tailoring Active Sites in Mesoporous Defect‐Rich NC/Vo‐WON Heterostructure Array for Superior Electrocatalytic Hydrogen Evolution

Tailoring active sites in earth‐abundant non‐noble metal electrocatalysts are required toward widespread applications in sustainable energy fields. Herein, an integrated mesoporous heterostructure array is reported by a hydrogenation/nitridation‐induced in situ growth strategy. Highly conductive oxygen‐vacancies‐rich tungsten oxynitride (V_o‐WON) nanorod array acts as the backbone encapsulated by ultrathin nitrogen‐doped carbon (NC) nanolayers, forming high‐quality shell/core NC/V_o‐WON heterostructures. Density functional theory calculations reveal that defect‐rich heterostructure arrays not only enhance the conductivity and modulate electronic structure but also promote the adsorption and dissociation of reactants and offer substantial potential sites. As expected, porous NC/V_o‐WON array exhibits a small overpotential of 16 mV at the current density of 10 mA cm^?2 and a low Tafel slope of 33 mV per decade in alkaline media, accompanied by negligible loss upon a large current density over 100 h. Benefiting from outstanding electrocatalytic hydrogen evolution reaction performance and stability, this defective heterostructure could serve as a prominent alternative electrocatalyst for renewable energy applications.