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The methyl transfer pathway is the most favorable pathway in the polyMB cycle and the polyMB cycle is more competitive than the alkene cycle. The addition of the phosphorus atom in the FAU could improve the productivity of propene in the MTP process.

Retinitis pigmentosa (RP) constitutes a class of common inherited retinal dystrophies. Patients with RP and comorbid primary angle-closure glaucoma (PACG) have been described, but the relationship between the diseases remains unclear. This study investigated the clinical and genetic characteristics of Chinese patients with RP and comorbid PACG.Of 1356 patients with RP, we analyzed the genetic features of 39 RP patients with PACG using next-generation sequencing and reviewed their clinical characteristics.In total, 18 patients with acute PACG and 21 patients with chronic PACG were included in this study; their age at examination was 50.54 ± 12.99 years (range, 25.0-71.0 years), and their age at PACG onset was 46.04 ± 14.50 years (range, 24.9-68.0 years). Additionally, the mean lens thickness (LT) was 4.49 ± 0.44 μm, and the mean axial length (AL) was 22.63 ± 1.17 mm. Notably, the prevalence of PACG in patients with RP was 2.88%; this was higher than the prevalence in the general population. This could be explained by nanophthalmos, thickened lentis, ectopia lentis, or zonular insufficiency. Furthermore, patients with a shorter AL, a greater LT, iridociliary cysts, or nanophthalmos exhibited earlier development of PACG. Overall, 30 disease-causing variants spanning 17 genes were identified in 56.41% of the patients, andOur findings revealed that there is a strong association between RP and PACG. Furthermore, intraocular pressure (IOP) should be measured in patients with RP to protect them from the aggravated damage of an elevated IOP.

We have theoretically investigated the hydrodesulphurisation (HDS) mechanism of hydrogenated thiophene over Cu–Mo-modified FAU zeolite using a two-layer ONIOM (our Own N-layered Integrated molecular Orbital and molecular Mechanics) study. The thiophene is hydrogenated to 2,3-dihydrothiophene (2,3-DHT), 2,5-dihydrothiophene (2,5-DHT) and tetrahydrothiophene (THT) due to moderate free energy barriers. Hydrogenolysis desulphurisation (HYD) and concerted direct desulphurisation (DDS) are discussed. Ring-opening, hydrogen transfer and C−S bond cleavage steps of thiophene derivatives are involved in the HYD process. The rate-determining steps are the hydrogen transfer step for 2,5-DHT and C−S bond cracking step for 2,3-DHT and THT. The concerted DDS pathway is probably more favourable than the HYD pathway in the desulphurisation of 2,5-DHT. The difference charge density (DCD) analysis reveals that for the ring-opening process, the electrons are migrated from the organic chain to the Cu–Mo catalytic centre. The reduced density gradient (RDG) plots indicate that both steric hindrance and a weak van der Waals (VDW) interaction exist between organic fragment and catalytic centre for all transition states (TSs). The localised orbital locator (LOL) maps suggest that there are strong covalent interactions and weak VDW interactions between the atoms in the forming chemical bonds.

The complex conformations of the cyclic moieties impact the physical and chemical properties of the molecules. In this work, we chose 22 molecules of four-, five-, and six-membered rings and performed a thorough conformational sampling using Cremer-Pople coordinates. We sampled hundreds or thousand of conformational structures including all well-known and many less well-known conformers for each molecule. We tried to represent the potential energy surfaces (PESs) by fitting the data to common analytical force field functional forms. Although the general features of PESs can be described by the essential force field functional forms, the accuracy of representation can be improved remarkably by including the torsion-bond and torsion-angle coupling terms. The best fit yields R-squared (R2) values close to 1.0 and mean absolute errors (MAEs) in energy less than 0.3 kcal/mol.

Retinal ganglion cell apoptotic death is the main pathological characteristic of glaucoma, which is the leading cause of irreversible blindness. Disruption of Ca

AIM: To study the changes of the red blood cell volume distribution width(RDW)level and the correlation between them in patients with primary angle-closure glaucoma(PACG).METHODS: Retrospective case-control study was conducted. A total of 306 PACG patients in Eye & ENT Hospital of Fudan University from February 2019 to October 2020 were selected as the case group and 126 healthy patients who received physical examination at the hospital during the same period were selected as the control group. The PACG patients were divided into three subgroups according to the mean defect of visual field(MD): mild(MD≤6dB), moderate(612dB). The detailed eye and physical examinations information of the two groups were collected from the medical data platform of Eye & ENT Hospital of Fudan University. The blood sample parameters were detected by automated hematology and biochemistry analyzers. Independent sample t-test, Chi-square test, one-way ANOVA test, Pearson correlation analyses and multiple linear regression analyses were performed in this research. RESULTS: There was no significant difference between the PACG group and the control group in age, gender, body mass index and blood pressure(P>0.05). Based on the laboratory results, the mean RDW level was significantly higher(t=2.132, P=0.034)in the PACG group(12.64%±0.96%)than that in the control group(12.45%±0.49%). Moreover, the mean RDW level and the mean hemoglobin(HG)level was significantly lower(P

With the rapid development of molecular biology technologies such as whole-genome testing in the past decade, non-coding RNA has been deeply explored. Circular RNA(circRNA)gradually becomes a hot topic in recent years, which plays an important role in the occurrence and development of a variety of diseases, and relevant studies have been carried out in ophthalmological diseases. This article will review the mechanism, basic research, and clinical findings of circRNA in various ophthalmic diseases, and briefly discuss the potential clinical significance of circRNA in ophthalmic diseases.

We have parametrized an AMBER force field in a TEAMFF database to accurately represent intra- and intermolecular interactions of cellulose. Parameters are obtained by fitting quantum mechanics (QM) energetic data on a training set of 12 simple and substituted heterocycles, alcohols, ethers, and saccharides. The temperature-dependent Lennard–Jones parameters were optimized by fitting experimental data of 23 molecular liquids at different temperatures using molecular dynamics (MD) simulations. Validation on cellobiose, the monomer of cellulose, exhibits excellent agreement between the data obtained by molecular mechanics calculations using the present force field and QM calculations in terms of conformational energies, structures, and vibrational frequencies. The MD simulation results of cellulose Iβ crystal agree well with the experimental data, showing a 0.1% deviation in density and less than 1% deviations in all the cell parameters.

We have theoretically studied the hydrodesulphurisation (HDS) mechanism of thiophene and its hydrogenated derivatives over sulphided Co–Mo catalysts supported by four zeolites (ZSM-5, FAU, Beta, MCM-22) by a two-layer ONIOM (our Own N-layered Integrated molecular Orbital and molecular Mechanics) method. Due to low energy barriers, the thiophene can be hydrogenated to 2,3-dihydrothiophene (2,3-DHT), 2,5-dihydrothiophene (2,5-DHT) and tetrahydrothiophene (THT). Direct desulphurisation (DDS) and hydrogenolysis desulphurisation (HYD) pathways were investigated in detail. The calculated results show that in DDS mechanism of thiophene, the rate-determining step is the C–S bond cleavage. In HYD mechanisms of 2,5-DHT, 2,3-DHT and THT, the rate-determining step is hydrogen transfer on ZSM-5, FAU and Beta zeolites except MCM-22 zeolite. The HYD of 2,3-DHT and THT should occur by the stepwise pathway. But for the 2,5-DHT, the concerted pathway is probably more favourable than the stepwise pathway. The reduced density gradient (RDG), differential charge density (DCD), and local orbital locator (LOL) maps show that for all transition states (TSs), there are complicated van der Waals (VDW) and electrostatic interactions between the organic fragment and the catalytic centre.

This work proposes a state-of-the-art hybrid kernel to calculate molecular similarity. Combined with Gaussian process models, the performance of the hybrid kernel in predicting molecular properties is comparable to that of the directed message-passing neural network (D-MPNN). The hybrid kernel consists of a marginalized graph kernel (MGK) and a radial basis function (RBF) kernel that operate on molecular graphs and global molecular features, respectively. Bayesian optimization was used to obtain the optimal hyperparameters for both models. The comparisons are performed on 11 publicly available data sets. Our results show that their performances are similar, their prediction errors are correlated, and the ensemble predictions of the two models perform better than either of them. Through principal component analysis, we found that the molecular embeddings of the hybrid kernel and the D-MPNN are also similar. The advantage of D-MPNN lies in the computational efficiency and scalability of large-scale data, while the advantage of the graph kernel models lies in the accurate uncertainty quantification.

The rubber tree, Hevea brasiliensis, produces natural rubber that serves as an essential industrial raw material. Here, we present a high-quality reference genome for a rubber tree cultivar GT1 using single-molecule real-time sequencing (SMRT) and Hi-C technologies to anchor the ∼1.47-Gb genome assembly into 18 pseudochromosomes. The chromosome-based genome analysis enabled us to establish a model of spurge chromosome evolution, since the common paleopolyploid event occurred before the split of Hevea and Manihot. We show recent and rapid bursts of the three Hevea-specific LTR-retrotransposon families during the last 10 million years, leading to the massive expansion by ∼65.88% (∼970 Mbp) of the whole rubber tree genome since the divergence from Manihot. We identify large-scale expansion of genes associated with whole rubber biosynthesis processes, such as basal metabolic processes, ethylene biosynthesis, and the activation of polysaccharide and glycoprotein lectin, which are important properties for latex production. A map of genomic variation between the cultivated and wild rubber trees was obtained, which contains ∼15.7 million high-quality single-nucleotide polymorphisms. We identified hundreds of candidate domestication genes with drastically lowered genomic diversity in the cultivated but not wild rubber trees despite a relatively short domestication history of rubber tree, some of which are involved in rubber biosynthesis. This genome assembly represents key resources for future rubber tree research and breeding, providing novel targets for improving plant biotic and abiotic tolerance and rubber production.

The pressure-dependent viscosity of 2,2,4-trimethylhexane is predicted using all-atom TEAM force field and the non-equilibrium periodic perturbation (PP) method. The viscosities predicted using the PP method do not show Newtonian plateau in the precision range of prediction for high-viscosity fluids. Using four alkane molecules as test cases, we found that our previously published force field, developed for ambient pressure conditions, is inaccurate for predicting viscosities under elevated pressures. Two approaches were attempted to enhance the pressure transferability of the force field: one involves moving the non-bond interaction site of hydrogen closer to that of attached carbon, which smooths the van der Waals (vdW) surface of molecule, and the other involves replacing the LJ-12-6 function by LJ-9-6, making the repulsion softer. Both approaches enhanced the pressure transferability; however, the former works well below 500 MPa, while the latter is valid under pressures up to 1 GPa.

The TEAM force-field database is extended to cover room-temperature ionic liquids (IL). The training set for parametrization includes 11 cations in five classes, imidazolium, pyridinium, pyrrolidin...

It has long remained elusive whether ${\mathrm{CuCo}}_{2}{\mathrm{S}}_{4}$ thiospinel shows bulk superconductivity (SC). Here we clarify the issue by studying the samples of sulfur-deficient ${\mathrm{CuCo}}_{2}{\mathrm{S}}_{3.7}$ and sulfurized ${\mathrm{CuCo}}_{2}{\mathrm{S}}_{4}$. The sample ${\mathrm{CuCo}}_{2}{\mathrm{S}}_{3.7}$ has a smaller lattice constant of $a=9.454$ \AA{}, and it is not superconducting down to 1.8 K. After a full sulfurization, the $a$ axis of the thiospinel phase increases to 9.475 \AA{}, and the thiospinel becomes nearly stoichiometric ${\mathrm{CuCo}}_{2}{\mathrm{S}}_{4}$, although a secondary phase of slightly Cu-doped ${\mathrm{CoS}}_{2}$ forms. Bulk SC at 4.2 K and Pauli paramagnetism have been demonstrated for the sulfurized ${\mathrm{CuCo}}_{2}{\mathrm{S}}_{4}$ by the measurements of electrical resistivity, magnetic susceptibility, and specific heat.

This work presents a Gaussian process regression (GPR) model on top of a novel graph representation of chemical molecules that predicts thermodynamic properties of pure substances in single, double, and triple phases. A transferable molecular graph representation is proposed as the input for a marginalized graph kernel, which is the major component of the covariance function in our GPR models. Radial basis function kernels of temperature and pressure are also incorporated into the covariance function when necessary. We predicted three types of representative properties of pure substances in single, double, and triple phases, i.e., critical temperature, vapor-liquid equilibrium (VLE) density, and pressure-temperature density. The data is collected from Knovel Data Analysis Beta: NIST ThermoDynamics Pure Compounds. The accuracy of the models is nearly identical to the precision of the experimental measurements. Moreover, the reliability of our predictions can be quantified on a per-sample basis using the posterior uncertainty of the GPR model. We compare our model against Morgan fingerprints and a graph neural network to further demonstrate the advantage of the proposed method. The marginalized graph kernel is computed using GraphDot package at https://github.com/yhtang/GraphDot. All codes used in this work can be found at https://github.com/Xiangyan93/Chem-Graph-Kernel-Machine.

The coarse-grained force field (CGFF) bridges the gap between atomistic and mesoscopic simulations. We take a scale-up approach to build CGFF from all-atom force field (AAFF). Since AAFF is developed using the quantum mechanics data, this approach essentially makes CGFF on first principles. Using small molecules, alkanes, electrolyte solutions and polymers as examples, we discuss three factors that impact the development of CGFFs from AAFFs in this article: (1) The mapping rules balancing the computational efficiency and fidelity of representation are proposed to define bead types. (2) The analytic functions used in AAFFs with the atom types as interaction sites are used for CGFFs with the bead types as interaction sites. The analytic functional forms include temperature-dependent van der Waals (VDW) parameters and modified Lorentz-Berthelot combination rules. (3) A hybrid parametrization strategy combining bottom-up and top-down methods, which has been used for developing AAFFs from QMD, is used for developing CGFFs from AAFFs.

This paper briefly introduces the generation of IPV9 and its characteristics. The two transition technologies of tunnel and double protocol stack are described. Both IPv4 to IPV9 and IPV9 to IPv4 are based on mature network conversion services and need to consider protocol compatibility. The paper introduces two routing algorithms, the shortest path algorithm and the distance vector algorithm which are common in static routing algorithms. The film transmission system of Beijing University of Posts and Telecommunications USES IPV9 and 5G technology, which is a relatively advanced transmission application of IPV9. Finally, the paper summarizes the convenience and security brought by the new network address, and provides new ideas for network development.

To explore the appropriate procedures for preparing extracellular microvesicles (MV) derived from human mesenchymal stem cells (MSC).Human MSCs from umbilical cords were cultured in a serum-free medium and maintained in a basal medium for 72 hours after the cell confluence reached to 80%. The supernatants of cultured cells were collected and MVs were enriched. MVs were identified by flow cytometry and electron microscopy. The total protein amount in MVs was used as a parameter for the content of MVs. The supernatants were adjusted to different pH values, and the output of MVs was detected. The supernatants were also collected for enriching the MV and detecting the protein content of MV after the cells were maintained in the basic medium for different time.Flow cytometric analysis showed that the MVs expressed CD9, CD63 and CD81, morphologically presented round under an electron microscope and the diameter of MV was around 100 nm. After enrichment of MV, the protein content of MVs in the supernatants was 416.8±128.1, 255.4±77.9 and 142.8±46.4 μg per 10MVs can be readily collected after MSCs were starved for 96 hours, and the pH of the supernatants is adjusted at 3.0.制备人间充质干细胞源细胞外微囊条件探索.探讨制备人间充质干细胞（mesenchymal stem cell, MSC）来源的细胞外微囊（extracellular microvesicle, MV）的适宜条件.无血清条件下培养人脐带来源MSC，细胞融合达80%时,用基础培养液培养72 h后，收集培养细胞的上清，使用浓缩试剂浓缩细胞外微囊，经流式细胞术及电子显微镜鉴定，以蛋白总量为微囊含量指标。调整上清不同pH值，探测MV收获量。去营养后，收集不同培养时间的培养上清，富集微囊并测定蛋白含量，确定不同培养时间微囊产量.富集的细胞外微囊表达CD9、CD63和CD81，电子显微镜下微囊呈圆形，直径在100 nm左右。使用微囊富集试剂盒收集、培养上清pH值分别为3,7和9时，每10去营养培养96 h后收集MSC培养上清，调整pH值至3.0，可获得较多的细胞微囊.

We developed a transferable coarse-grained (CG) force field to cover polyethers and polyether blends in this work. On the basis of the perturbation theory of liquids and high-temperature expansion, we examined the theoretical foundation of using a temperature-dependent function to represent the nonbonded interactions. Using a mapping rule that balances molecular representation with the degree of coarse-graining, we defined seven CG beads that represent common polyethers. A hybrid parametrization workflow combining bottom-up and top-down approaches was applied to derive the force field parameters. The large ratio between the number of training data and the number of adjustable parameters enables the resulting force field to accurately predict many polymer properties, including cohesive energies, structural parameters, glass-transition temperatures, and surface tensions. In addition, the force field is capable of simulating polyether blends using modified Lorentz–Berthelot combination rules. As a preliminar...

Single-crystalline sponge-like MFI mesoporous zeolites (SSMZs) have been synthesized by using bolaform surfactants with an axial chiral binaphthyl core in the hydrophobic tail and triquaternary ammonium head groups, as bifunctional organic structure-directing agents (OSDAs). By changing the length of alkyl chain between a triquaternary ammonium head group and a binaphthyl group from 4 to 10 carbons, SSMZs with high specific surface area (382-434 m2 g-1 ), abundant micropore-mesopore connectivity, and uniform mesopore diameter (4-10 nm) were obtained. OSDAs with an alkyl chain length of 11 and 12 carbons led to the formation of nanorod-constructed mesoporous MFI zeolites. A geometrical matching between the cylindrical arrangement of the binaphthyl groups and the zeolitic framework is speculated to be the key factor for the formation of mesoporous zeolites. The SSMZ zeolites, with abundant mesopores beneficial for the diffusion of reactants, exhibited significantly higher catalytic efficiencies than those of the conventional ZSM-5 with a microcrystal morphology (≈1.5 μm).