A new species of Cincticostella Allen, 1971 (Ephemeroptera, Ephemerellidae) from Yunnan, China and establishment of a new species complex.

Cincticostellajianchuan sp. nov. from Dali Bai Autonomous Prefecture, Yunnan Province, China, is described based on chorionic structure, nymph, and winged stages. The new species is closely related to C.fusca (Kang & Yang, 1995), but it can be distinguished in the male imago stage by its mesonotum and penes morphology, coloration, and the forking point of the stem of MA+Rs on the forewing; in the nymph stage, it can be distinguished by the length of the posterolateral projections of abdominal segment IX and the setation of the abdominal terga. Compared to other congeners, nymphs and male imagoes of the new species and C.fusca share several morphological characteristics, such as a larger body, mesothorax with medially notched anterolateral projections, forefemur without a subapical band of transverse spines of the nymphs, the area between C, Sc and R1 of the forewings distinctly pigmented, and an apical sclerite on the ventral face of the penes of the male imagoes, supporting the proposition of a new species complex, the jianchuan complex. The systematics of Cincticostella and related genera are discussed briefly.

Resolution enhancement for interrogating fiber Bragg grating sensor network using dilated U-Net.

In the fiber Bragg grating (FBG) sensor network, the signal resolution of the reflected spectrum is correlated with the network's sensing accuracy. The interrogator determines the signal resolution limits, and a coarser resolution results in an enormous uncertainty in sensing measurement. In addition, the multi-peak signals from the FBG sensor network are often overlapped; this increases the complexity of the resolution enhancement task, especially when the signals have a low signal-to-noise ratio (SNR). Here, we show that deep learning with U-Net architecture can enhance the signal resolution for interrogating the FBG sensor network without hardware modifications. The signal resolution is effectively enhanced by 100 times with an average root mean square error (RMSE) < 2.25 pm. The proposed model, therefore, allows the existing low-resolution interrogator in the FBG setup to function as though it contains a much higher-resolution interrogator.

Dilated convolutional neural networks for fiber Bragg grating signal demodulation.

In quasi-distributed fiber Bragg grating (FBG) sensor networks, challenges are known to arise when signals are highly overlapped and thus hard to separate, giving rise to substantial error in signal demodulation. We propose a multi-peak detection deep learning model based on a dilated convolutional neural network (CNN) that overcomes this problem, achieving extremely low error in signal demodulation even for highly overlapped signals. We show that our FBG demodulation scheme enhances the network multiplexing capability, detection accuracy and detection time of the FBG sensor network, achieving a root-mean-square (RMS) error in peak wavelength determination of < 0.05 pm, with a demodulation time of 15 ms for two signals. Our demodulation scheme is also robust against noise, achieving an RMS error of < 0.47 pm even with a signal-to-noise ratio as low as 15 dB. A comparison on our high-performance computer with existing signal demodulation methods shows the superiority in RMS error of our dilated CNN implementation. Our findings pave the way to faster and more accurate signal demodulation methods, and testify to the substantial promise of neural network algorithms in signal demodulation problems.

O-GlcNAc regulates gene expression by controlling detained intron splicing.

Intron detention in precursor RNAs serves to regulate expression of a substantial fraction of genes in eukaryotic genomes. How detained intron (DI) splicing is controlled is poorly understood. Here, we show that a ubiquitous post-translational modification called O-GlcNAc, which is thought to integrate signaling pathways as nutrient conditions fluctuate, controls detained intron splicing. Using specific inhibitors of the enzyme that installs O-GlcNAc (O-GlcNAc transferase, or OGT) and the enzyme that removes O-GlcNAc (O-GlcNAcase, or OGA), we first show that O-GlcNAc regulates splicing of the highly conserved detained introns in OGT and OGA to control mRNA abundance in order to buffer O-GlcNAc changes. We show that OGT and OGA represent two distinct paradigms for how DI splicing can control gene expression. We also show that when DI splicing of the O-GlcNAc-cycling genes fails to restore O-GlcNAc homeostasis, there is a global change in detained intron levels. Strikingly, almost all detained introns are spliced more efficiently when O-GlcNAc levels are low, yet other alternative splicing pathways change minimally. Our results demonstrate that O-GlcNAc controls detained intron splicing to tune system-wide gene expression, providing a means to couple nutrient conditions to the cell's transcriptional regime.

Structure-Based Evolution of Low Nanomolar O-GlcNAc Transferase Inhibitors.

Reversible glycosylation of nuclear and cytoplasmic proteins is an important regulatory mechanism across metazoans. One enzyme, O-linked N-acetylglucosamine transferase (OGT), is responsible for all nucleocytoplasmic glycosylation and there is a well-known need for potent, cell-permeable inhibitors to interrogate OGT function. Here we report the structure-based evolution of OGT inhibitors culminating in compounds with low nanomolar inhibitory potency and on-target cellular activity. In addition to disclosing useful OGT inhibitors, the structures we report provide insight into how to inhibit glycosyltransferases, a family of enzymes that has been notoriously refractory to inhibitor development.

Phosphorus-containing polymers from THPS. IV: Synthesis and properties of phosphorus-containing polybenzoxazines as a green route for recycling toxic phosphine (PH3) tail gas.

A convenient route to convert the highly toxic phosphine (PH3) tail gas into high-performance polybenzoxazines was first described in this paper. Two aliphatic polyamines, namely tris(aminomethyl)phosphine oxide and bis(aminomethyl)phenylphosphine oxide, were synthesized from tetrakis(hydroxymethyl)phosphonium sulfate (THPS), a green derivative of PH3 tail gas. And then two novel phosphorus-containing benzoxazine monomers, tris(3,4-dihydro-2H-1,3-benzoxazin-3-yl-methyl)phosphine oxide (TBOz) and benzylbis(3,4-dihydro-2H-1,3-benzoxazin-3-yl-methyl) phosphine oxide (BBOz) were prepared by three-steps procedure. FT-IR and DSC technologies were adopted to study the thermal-initiated polymerization behaviors of two benzoxazine monomers. Thermal properties of these crosslinked polymers were studied by TGA and DMA. The results display that the polybenzoxazines (PTBOz and PBBOz) exhibite good thermal stabilities and high glass transition temperatures. The char yield of polybanzoxazine is high as 47% and indiactes that phosphorus-containing polybenzoxazines show high fire-retardancy. The surface free energies of the PTBOz and PBBOz are 37.1 and 40.4mJm-2 by Owens two-liquid method. The dielectric properties of the PTBOz and PBBOz remaine near constant in the experimental frequency range.

A small molecule that inhibits OGT activity in cells.

O-GlcNAc transferase (OGT) is an essential mammalian enzyme that regulates numerous cellular processes through the attachment of O-linked N-acetylglucosamine (O-GlcNAc) residues to nuclear and cytoplasmic proteins. Its targets include kinases, phosphatases, transcription factors, histones, and many other intracellular proteins. The biology of O-GlcNAc modification is still not well understood, and cell-permeable inhibitors of OGT are needed both as research tools and for validating OGT as a therapeutic target. Here, we report a small molecule OGT inhibitor, OSMI-1, developed from a high-throughput screening hit. It is cell-permeable and inhibits protein O-GlcNAcylation in several mammalian cell lines without qualitatively altering cell surface N- or O-linked glycans. The development of this molecule validates high-throughput screening approaches for the discovery of glycosyltransferase inhibitors, and further optimization of this scaffold may lead to yet more potent OGT inhibitors useful for studying OGT in animal models.

Mechanism of formation of sulphur aroma compounds from l-ascorbic acid and l-cysteine during the Maillard reaction.

The sulphur aroma compounds produced from a phosphate-buffered solution (pH 8) of l-cysteine and l-, l-[1-13C] or l-[4-13C] ascorbic acid, heated at 140±2°C for 2h, were examined by headspace SPME in combination with GC-MS. MS data indicated that C-1 of l-ascorbic acid was not involved in the formation of sulphur aroma compounds. The sulphur aroma compounds formed by reaction of l-ascorbic acid with l-cysteine mainly contained thiophenes, thiazoles and sulphur-containing alicyclic compounds. Among these compounds, 1-butanethiol, diethyl disulphide, 5-ethyl-2-methylthiazole, cis and trans-3,5-dimethyl-1,2,4-trithiolane, thieno[2,3-b]thiophene, thieno[3,2-b]thiophene, cis and trans-3,5-diethyl-1,2,4-trithiolane, 1,2,5,6-tetrathiocane, 2-ethylthieno[2,3-b]thiophene, 2,4,6-trimethyl-1,3,5-trithiane and cyclic octaatomic sulphur (S8) were formed solely by l-cysteine degradation, and the rest by reaction of l-ascorbic acid degradation products, such as hydroxybutanedione, butanedione, acetaldehyde, acetol, pyruvaldehyde and formaldehyde with l-cysteine or its degradation products, such as H2S and NH3. A new reaction pathway from l-ascorbic acid via its degradation products was proposed.

[Analysis of the chemical constituents of volatile oil from Asarum insigne by GC-MS].

OBJECTIVE: To analyse the chemical constituents of volatile oil from Asarum insigne. METHODS: The volatile oil from Asarum insigne was isolated with steam distillation and identified by capillary GC/MS method. RESULTS: 68 Volatile components were identified and determined, accounting for 92.18% of the total peak area. The main volatile compounds and their relative contents are camphene (13.48%), alpha-pinene (12.44%), beta-pinene (11.07%), borneol (8.12%), trans-beta-farnesene (5.91%), elemicin (5.38%), 1,3-benzodioxole-5-(2-propenyl) (3.06%), myristicin (2.95%), ledene (2.47%), eucalyptol (2.33%), patchouli alcohol (2.25%), alpha-bisabolene (2.04%) and bornyl acetate (1.36%) etc. CONCLUSION: The study provided solid and scientific proof for the exploitation and utilization of Asarum insigne.

1-(4-Methyl-benzo-yl)-3-[5-(4-pyrid-yl)-1,3,4-thia-diazol-2-yl]urea.

In the title compound, C(16)H(13)N(5)O(2)S, the five non-H atoms of the urea linkage adopt a planar configuration owing to the presence of an intra-molecular N-H⋯O hydrogen bond. The maximum deviation from planarity is 0.022 (2) Å. The thia-diazole and pyridine heterocyclic rings are close to being coplanar, with a dihedral angle of 6.7 (2)° between their mean planes. Inter-molecular N-H⋯O hydrogen bonds link two neighbouring mol-ecules into centrosymmetric R(2) (2)(8) dimers. Four C atoms and the attached H atoms of the benzene ring are disordered over two positions of equal occupancy.