Differential expression of neuropeptide F in the digestive organs of female freshwater prawn, Macrobrachium rosenbergii, during the ovarian cycle

Neuropeptide F is a key hormone that controls feeding in invertebrates, including decapod crustaceans. We investigated the differential expression of Macrobrachium rosenbergii neuropeptide F (MrNPF) in the digestive organs of female prawns, M. rosenbergii, during the ovarian cycle. By using RT-qPCR, the expression of MrNPF mRNA in the esophagus (ESO), cardia (CD), and pylorus (PY) of the foregut (FG) gradually increased from stage II and peaked at stage III. In the midgut (MG), hindgut (HG), and hepatopancreas (HP), MrNPF mRNA increased from stage I, reaching a maximal level at stage II, and declined by about half at stages III and IV (P < 0.05). In the ESO, CD, and PY, strong MrNPF-immunoreactivities were seen in the epithelium, muscle, and lamina propria. Intense MrNPF-ir was found in the MG cells and the muscular layer. In the HG, MrNPF-ir was detected in the epithelium of the villi and gland regions, while MrNPF-ir was also more intense in the F-, R-, and B-cells in the HP. However, we found little colocalization between the MrNPF and PGP9.5/ChAT in digestive tissues, implying that most of the positive cells might not be neurons but could be digestive tract-associated endocrine cells that produce and secrete MrNPF to control digestive organ functions in feeding and utilizing feed. Taken together, our first findings indicated that MrNPF was differentially expressed in digestive organs in correlation with the ovarian cycle, suggesting an important link between MrNPF, the physiology of various digestive organs in feeding, and possibly ovarian maturation in female M. rosenbergii.

Enantioselective recognition, synthesis, and separation of pharmaceutical compounds at chiral metallic surfaces

The development of new pharmaceutical compounds is challenging because most of them are based on enantiopure chiral molecules, which exhibit unique properties for therapy. However, the synthesis of pharmaceutical compounds in the absence of a chiral environment naturally leads to a racemic mixture. Thus, to control their synthesis, an asymmetric environment is required, and chiral homogeneous catalysts are typically used to synthesize enantiopure pharmaceutical compounds (EPC). Nevertheless, homogeneous catalysts are difficult to recover after the reaction, generating additional problems and costs in practical processes. Thus, the development of chiral heterogeneous catalysts is a timely topic. In a more general context, such chiral materials cannot only be used for synthesis, but also to recognize and separate enantiomers. In the frame of these different challenges, we give in this review a short introduction to strategies to extrinsically and intrinsically modify heterogeneous metal matrixes for the enantioselective synthesis, recognition, and separation of chiral pharmaceutical compounds.

Electrocatalytic Hydrogen Evolution of Immobilized Copper Complex on Carbonaceous Materials: From Neutral Water to Seawater

Electrochemical hydrogen evolution reaction (HER) is an appealing strategy to utilize renewable electricity to produce green H2 . Moreover, use of neutral-pH electrolyte such as water and seawater for the HER has long been desired for eco-friendly energy production that aligns with net zero emission goal. Herein, new heterogeneous catalysts were developed by dispersing an HER-active copper complex containing N4 -Schiff base macrocycle (CuL) on carbonaceous materials, i. e. multi-walled carbon nanotube (CNT) and graphene oxide (GO), via non-covalent interaction and investigated their HER performance. It was found that CuL/GO exhibited higher HER activity than CuL/CNT, possibly due to its significantly larger amount of CuL immobilized onto GO. In addition, CuL/GO showed satisfactory HER performance in a neutral (pH 7) NaCl electrolyte solution. Notably, the performances of CuL/GO were boosted up when performed in natural seawater sample with the faradaic efficiency of 70 % and 3 times higher amount of H2 at -0.6 V vs reversible hydrogen electrode (RHE), in comparison to the HER in a NaCl electrolyte. Furthermore, it possessed a low overpotential of 139 mV at -10 mA/cm2 . This demonstrated the potential use of CuL/GO as an effective HER catalyst in seawater for further sustainable development.

Kazachstania pintolopesii in Blood and Intestinal Wall of Macrophage-Depleted Mice with Cecal Ligation and Puncture, the Control of Fungi by Macrophages during Sepsis

Although macrophage depletion is a possible emerging therapeutic strategy for osteoporosis and melanoma, the lack of macrophage functions can lead to inappropriate microbial control, especially the regulation of intestinal microbiota. Cecal ligation and puncture (CLP) sepsis was performed in regular mice and in mice with clodronate-induced macrophage depletion. Macrophage depletion significantly increased the mortality and severity of sepsis-CLP mice, partly through the increased fecal Ascomycota, especially Kazachstania pintolopesii, with polymicrobialbacteremia (Klebsiella pneumoniae, Enterococcus faecalis, and Acinetobacter radioresistens). Indeed, macrophage depletion with sepsis facilitated gut dysbiosis that directly affected gut permeability as yeast cells were located and hidden in the colon crypts. To determine the interactions of fungal molecules on bacterial abundance, the heat-kill lysate of fungi (K. pintolopesii and C. albicans) and purified (1→3)-β-d-glucan (BG; a major component of the fungal cell wall) were incubated with bacteria that were isolated from the blood of macrophage-depleted mice. There was enhanced cytokine production of enterocytes (Caco-2) after the incubation of the lysate of K. pintolopesii (isolated from sepsis mice), the lysate of C. albicans (extracted from sepsis patients), and BG, together with bacterial lysate. These data support a possible influence of fungi in worsening sepsis severity. In conclusion, macrophage depletion enhanced K. pintolopesii in feces, causing the overgrowth of fecal pathogenic bacteria and inducing a gut permeability defect that additively worsened sepsis severity. Hence, the fecal fungus could be spontaneously elevated and altered in response to macrophage-depleted therapy, which might be associated with sepsis severity.

Highly Enantioselective Synthesis of Pharmaceuticals at Chiral-Encoded Metal Surfaces

Enantioselective catalysis is of crucial importance in modern chemistry and pharmaceutical science. Although various concepts have been used for the development of enantioselective catalysts to obtain highly pure chiral compounds, most of them are based on homogeneous catalytic systems. Recently, we successfully developed nanostructured metal layers imprinted with chiral information, which were applied as electrocatalysts for the enantioselective synthesis of chiral model compounds. However, so far such materials have not been employed as heterogeneous catalysts for the enantioselective synthesis of real pharmaceutical products. In this contribution, we report the asymmetric synthesis of chiral pharmaceuticals (CPs) with chiral imprinted Pt-Ir surfaces as a simple hydrogenation catalyst. By fine-tuning the experimental parameters, a very high enantioselectivity (up to 95 % enantiomeric excess) with good catalyst stability can be achieved. The designed materials were also successfully used as catalytically active stationary phases for the continuous asymmetric flow synthesis of pharmaceutical compounds. This illustrates the possibility of producing real chiral pharmaceuticals at such nanostructured metal surfaces for the first time.

Enhanced Electrocatalytic CO2 Reduction Reactivity of S- and N-Doped Fe-Embedded Graphene

In this work, we studied the reaction mechanisms for CO2 reduction reaction (CRR) on the iron-doped graphene and its coordinating sulfur (S) and nitrogen (N) variants, FeNn S4-n (n=1-4), using density functional theory calculations. Our results revealed that the electronic property and catalytic reactivity of the surfaces can be tuned by varying the N and S atoms ratio. The CRR activities of the mixed surfaces, FeN3 S1 , FeN2 S2 , and FeN1 S3 , were better than FeN4 and FeS4 , where the absolute value of the limiting potential of the mixed surface decreased by 0.3 V. Considering the stability, we suggest FeN3 S surface to be favorable for CRR. For the bare surfaces, we found a positive linear correlation between the magnetic moment and the charge of Fe metal. For these surfaces, the reduction of CO (*CO+(H+ +e- )→*CHO) was important in deciding the limiting potential. We found that the adsorption energy of CO displayed a volcano relationship with the magnetic moment of the Fe atom. The study showed that the change of local coordinating structure around the Fe atom could modify the electronic and magnetic properties of the active Fe center and improve the CRR activity performance.

Development of peptide nucleic acid-based bead array technology for Bacillus cereus detection

Numerous novel methods to detect foodborne pathogens have been extensively developed to ensure food safety. Among the important foodborne bacteria, Bacillus cereus was identified as a pathogen of concern that causes various food illnesses, leading to interest in developing effective detection methods for this pathogen. Although a standard method based on culturing and biochemical confirmative test is available, it is time- and labor-intensive. Alternative PCR-based methods have been developed but lack high-throughput capacity and ease of use. This study, therefore, attempts to develop a robust method for B. cereus detection by leveraging the highly specific pyrrolidinyl peptide nucleic acids (PNAs) as probes for a bead array method with multiplex and high-throughput capacity. In this study, PNAs bearing prolyl-2-aminocyclopentanecarboxylic acid (ACPC) backbone with groEL, motB, and 16S rRNA sequences were covalently coupled with three sets of fluorescently barcoded beads to detect the three B. cereus genes. The developed acpcPNA-based bead array exhibited good selectivity where only signals were detectable in the presence of B. cereus, but not for other species. The sensitivity of this acpcPNA-based bead assay in detecting genomic DNA was found to be 0.038, 0.183 and 0.179 ng for groEL, motB and 16S rRNA, respectively. This performance was clearly superior to its DNA counterpart, hence confirming much stronger binding strength of acpcPNA over DNA. The robustness of the developed method was further demonstrated by testing artificially spiked milk and pickled mustard greens with minimal interference from food metrices. Hence, this proof-of-concept acpcPNA-based bead array method has been proven to serve as an effective alternative nucleic acid-based method for foodborne pathogens.

All green sulfolane-based solvent enhanced electrical conductivity and rigidity of perovskite crystalline layer

Industrial commercialization of perovskite solar cells not only depends on sufficient device performance, but also requires complete elimination of hazardous solvents in the fabrication process to enable sustainable development of the technology. This work reports a new solvent system based on sulfolane, [Formula: see text]-butyrolactone (GBL), and acetic acid (AcOH) as a significantly greener alternative to common but more hazardous solvents. Interestingly, this solvent system not only resulted in densely-packed perovskite layer of bigger crystal size and better crystallinity, the grain boundaries were found to be more rigid and highly conductive to electrical current. The physical changes at the grain boundaries were due to the sulfolane-infused crystal interfaces, which were expected to facilitate better charge transfer and provide stronger barrier to moisture within the perovskite layer, yielding higher current density and longer performance of the device as a result. In fact, by using a mixed solvent system consisting of sulfolane, GBL, and AcOH in the volume ratio of 70.0:27.5:2.5, the device stability was better and the photovoltaic performance was statistically comparable with those prepared using DMSO-based solvent. Our report reflects unprecedented findings of enhanced electrical conductivity and rigidity of the perovskite layer simply by using an appropriate choice of the all-green solvent.

Computational and experimental investigations of the giant dielectric property of Na1/2Y1/2Cu3Ti4O12 ceramics

A modified sol-gel method was used to successfully produce Na_1/2Y_1/2Cu₃Ti₄O₁₂ ceramics with high dielectric permittivity. The dielectric permittivity of Na_1/2Y_1/2Cu₃Ti₄O₁₂ ceramics reaches values larger than 10⁴ at room temperature and 1 kHz. Moreover, these ceramics exhibit two distinct thermally induced dielectric relaxations over a broad temperature range. The loss tangent is indeed small, ~0.032-0.035. At low temperatures, dielectric relaxation was attributed to the oxygen vacancy effect, while at high temperatures, it was attributed to grain boundary and sample-electrode contact effects. Our calculations revealed that Y and Na ions are likely to occupy Ca and Cu sites, respectively. As a result, other Cu related phases, especially CuO, were observed at the grain boundaries. Based on our analysis, there is a charge compensation between Na and Y ions in Na_1/2Y_1/2Cu₃Ti₄O₁₂. Additionally, the Cu⁺ and Ti³⁺ states observed in our XPS study originate from the presence of an oxygen vacancy in the lattice. Last, the primary cause of the enormous dielectric permittivity of Na_1/2Y_1/2Cu₃Ti₄O₁₂ ceramics primarily comes from the internal barrier layer capacitor effect.