m5U-GEPred: prediction of RNA 5-methyluridine sites based on sequence-derived and graph embedding features.

5-Methyluridine (m5U) is one of the most common post-transcriptional RNA modifications, which is involved in a variety of important biological processes and disease development. The precise identification of the m5U sites allows for a better understanding of the biological processes of RNA and contributes to the discovery of new RNA functional and therapeutic targets. Here, we present m5U-GEPred, a prediction framework, to combine sequence characteristics and graph embedding-based information for m5U identification. The graph embedding approach was introduced to extract the global information of training data that complemented the local information represented by conventional sequence features, thereby enhancing the prediction performance of m5U identification. m5U-GEPred outperformed the state-of-the-art m5U predictors built on two independent species, with an average AUROC of 0.984 and 0.985 tested on human and yeast transcriptomes, respectively. To further validate the performance of our newly proposed framework, the experimentally validated m5U sites identified from Oxford Nanopore Technology (ONT) were collected as independent testing data, and in this project, m5U-GEPred achieved reasonable prediction performance with ACC of 91.84%. We hope that m5U-GEPred should make a useful computational alternative for m5U identification.

3D Printed Gas Distributor for Enhanced Production of CaCO3 via Bubbling Carbonation.

Bubbling carbonation is the most widely used method for production of CaCO3. A structure-controllable preparation of calcium carbonate with homogeneous crystallinity and narrow particle size distribution is generally required. In this work, a gas distributor is designed and fabricated by light-curing three-dimensional (3D) printing technology to optimize the pore size and distribution of the distributor. The printed gas distributor is combined with a home-made glass vessel to form a simple carbonation reactor without the need for stirring. With the optimized gas flow rate and concentration of Ca(OH)2, this reactor produces small-sized bubbles continuously and uniformly. A homogeneous bubble flow regime can be thus easily formed with the printed distributor, which leads to an enhanced production of calcium carbonate at room temperature with a uniform morphology and narrow particle size distribution. The time required for carbonization is significantly reduced as well. The present study extends the 3D printing to the construction of bubbling reactors with broad applications beyond production of CaCO3.

Multireference configuration interaction study of the predissociation of C2 via its F1Πu state.

Photodissociation is one of the main destruction pathways for dicarbon (C2) in astronomical environments, such as diffuse interstellar clouds, yet the accuracy of modern astrochemical models is limited by a lack of accurate photodissociation cross sections in the vacuum ultraviolet range. C2 features a strong predissociative F1Πu-X1Σg + electronic transition near 130 nm originally measured in 1969; however, no experimental studies of this transition have been carried out since, and theoretical studies of the F1Πu state are limited. In this work, potential energy curves of excited electronic states of C2 are calculated with the aim of describing the predissociative nature of the F1Πu state and providing new ab initio photodissociation cross sections for astrochemical applications. Accurate electronic calculations of 56 singlet, triplet, and quintet states are carried out at the DW-SA-CASSCF/MRCI+Q level of theory with a CAS(8,12) active space and the aug-cc-pV5Z basis set augmented with additional diffuse functions. Photodissociation cross sections arising from the vibronic ground state to the F1Πu state are calculated by a coupled-channel model. The total integrated cross section through the F1Πu v = 0 and v = 1 bands is 1.198 × 10-13 cm2 cm-1, giving rise to a photodissociation rate of 5.02 × 10-10 s-1 under the standard interstellar radiation field, much larger than the rate in the Leiden photodissociation database. In addition, we report a new 21Σu + state that should be detectable via a strong 21Σu +-X1Σg + band around 116 nm.

Coupled Cluster Characterization of 1-, 2-, and 3-Pyrrolyl: Parameters for Vibrational and Rotational Spectroscopy.

Pyrrolyl (C4H4N) is a nitrogen-containing aromatic radical that is a derivative of pyrrole (C4H5N) and is an important intermediate in the combustion of biomass. It is also relevant for chemistry in Titan's atmosphere and may be present in the interstellar medium. The lowest-energy isomer, 1-pyrrolyl, has been involved in many experimental and theoretical studies of the N-H photodissociation of pyrrole, yet it has only been directly spectroscopically detected via electron paramagnetic resonance and through the photoelectron spectrum of the pyrrolide anion, yielding three vibrational frequencies. No direct measurements of 2- or 3-pyrrolyl have been made, and little information is known from theoretical calculations beyond their relative energies. Here, we present an ab initio quantum chemical characterization of the three pyrrolyl isomers at the CCSD(T) level of theory in their ground electronic states, with an emphasis on spectroscopic parameters relevant for vibrational and rotational spectroscopy. Equilibrium geometries were optimized at the CCSD(T)/cc-pwCVTZ level of theory, and the quadratic, cubic, and partial quartic force constants were evaluated at CCSD(T)/ANO0 for analysis using second-order vibrational perturbation theory to obtain harmonic and anharmonic vibrational frequencies. In addition, zero-point-corrected rotational constants, electronic spin-rotation tensors, and nuclear hyperfine tensors are calculated for rotational spectroscopy. Our computed structures and energies agree well with earlier density functional theory calculations, and spectroscopic parameters for 1-pyrrolyl are compared with the limited existing experimental data. Finally, we discuss strategies for detecting these radicals using rotational and vibrational spectroscopy on the basis of the calculated spectroscopic constants.

De Novo Design of Covalent Organic Framework Membranes toward Ultrafast Anion Transport.

The emergence of all-organic frameworks is of fundamental significance, and designing such structures for anion conduction holds great promise in energy conversion and storage applications. Herein, inspired by the efficient anion transport within organisms, a de novo design of covalent organic frameworks (COFs) toward ultrafast anion transport is demonstrated. A phase-transfer polymerization process is developed to acquire dense and ordered alignment of quaternary ammonium-functionalized side chains along the channels within the frameworks. The resultant self-standing COFs membranes exhibit one of the highest hydroxide conductivities (212 mS cm-1 at 80 °C) among the reported anion exchange membranes. Meanwhile, it is found that shorter, more hydrophilic side chains are favorable for anion conduction. The present work highlights the prospects of all-organic framework materials as the platform building blocks in designing ion exchange membranes and ion sieving membranes.

Automatic enumeration of gold nanomaterials at the single-particle level.

In this study, we developed a highly sensitive automatic counting method for gold nanomaterials at the single particle level, which can serve as a general sensing platform based on counting of gold nanomaterials. This method substantially improved the sensitivity and accuracy for AuNP counting by adopting the color image processing based on the distinctive localized plasmonic light-scattering of gold nanomaterials. The 60-nm AuNPs, with concentrations down to 4 fM, can be detected with our method. As a universal counting approach for gold nanomaterials, such as gold nanospheres, nanorods, and aggregates from particles under detectable size, this quantification method should be versatile to a breadth of applications.

[Epidemiological survey of HBsAg carriers in the Uighur and Han populations in the Khotan Area of Xinjiang autonomous region].

OBJECTIVE: To survey nonsymptomatic HBsAg carriers in the Uighur and Han populations in Khotan Area of Xinjiang Autonomous region. METHOD: HBsAg was detected using colloidal gold-labeled double antibody sandwich method. RESULTS: These investigations included 2 597 subjects consisting of 2 022 Uighur and 575 Han subjects. The total HBsAg carrier rate in the Uighur population was 1.48% (30/2 022), specifically 1.078% in male and 1.59% in female subjects. No significant differences were observed in the age between male and female HBsAg carriers, who had an average age of 35 years. In the Han population, the total HBsAg carrier rate was 6.09% (30/575), and was 5.6% in male and 4.4% in female subjects. The average age of the male carriers was 36.3 years and 27.6 years in the female carriers, which showed significant difference in respect to HBsAg carrier rate. The HBsAg carrier rate showed significant difference between Uighur and Han populations in Khotan Area (P<0.01). CONCLUSIONS: The HBsAg carrier rate in Uighur population in Khotan Area is consistent with that in areas with low HBV infection, whereas the Han population exhibit features similar to those in areas with moderately HBV prevalence in the inland regions. The low HBsAg carrier rate in Uighurs might be attributed to the their customs in diet, eating habit, local living environment and the difference in HLA gene distribution. The authors suppose that such antigens as HLA-Bw41 might be protective against HBV infection.