High-density generation of spatial transcriptomics with STAGE.

Spatial transcriptome technologies have enabled the measurement of gene expression while maintaining spatial location information for deciphering the spatial heterogeneity of biological tissues. However, they were heavily limited by the sparse spatial resolution and low data quality. To this end, we develop a spatial location-supervised auto-encoder generator STAGE for generating high-density spatial transcriptomics (ST). STAGE takes advantage of the customized supervised auto-encoder to learn continuous patterns of gene expression in space and generate high-resolution expressions for given spatial coordinates. STAGE can improve the low quality of spatial transcriptome data and smooth the generated manifold of gene expression through the de-noising function on the latent codes of the auto-encoder. Applications to four ST datasets, STAGE has shown better recovery performance for down-sampled data than existing methods, revealed significant tissue structure specificity, and enabled robust identification of spatially informative genes and patterns. In addition, STAGE can be extended to three-dimensional (3D) stacked ST data for generating gene expression at any position between consecutive sections for shaping high-density 3D ST configuration.

Identification of unexpected unlabeled N,N-dimethylamide formation in the synthesis of deuterated fragment of ribociclib by a HATU-mediated coupling reaction.

Starting from N,N-dimethylamine and D2 O, deuterated fragment of ribociclib was synthesized for use as a mass spectroscopy internal standard. Furthermore, systematic studies on D0 (unlabeled material) formation during the amidation reaction were performed, leading to the identification of a coupling reagent, HATU (O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate), as main cause. Finally, an alternative route was designed using EDCI/HOBT as coupling reagents to produce the desired deuterated compound without D0 residue.

Synthesis of obeticholic acid, a farnesoid X receptor agonist, and its major metabolites labeled with deuterium.

Simple and facile methods for the synthesis of deuterium-labeled obeticholic acid and its 2 metabolites, glycine and taurine conjugates of obeticholic acid, are described herein. The 3 deuterated compounds were applicable for use as internal standards in drug development.

Palladium-catalyzed oxidative cross-coupling of azole-4-carboxylates with indoles: an approach to the synthesis of pimprinine.

An efficient and straightforward method for the production of 5-(3-indolyl)azoles incorporating the privileged structures indoles and azoles via palladium-catalyzed double C-H bond cleavage under mild conditions was disclosed. As expected, this protocol provided an easy method for the synthesis of indole alkaloids pimprinine and WS-30581 A in moderate yields.

Tessellating the Latent Space for Non-Adversarial Generative Auto-Encoders.

Non-adversarial generative models are relatively easy to train and have less mode collapse than adversarial models. However, they are not very accurate in approximating the target distribution in latent space because they don't have a discriminator. To this end, we develop a novel divide-and-conquer model called Tessellated Wasserstein Auto-Encoders (TWAE) which has less statistical error in approximating the target distribution. TWAE tessellates the support of the target distribution into a given number of regions using the centroidal Voronoi tessellation (CVT) technique and designs data batches according to the tessellation instead of random shuffling for accurate computation of discrepancy. Theoretically, we demonstrate that the error in estimating the discrepancy decreases as the number of samples n and the regions m of the tessellation increase at rates of [Formula: see text] and [Formula: see text], respectively. TWAE is very flexible to different non-adversarial metrics and can significantly enhance their generative performance in terms of Fréchet inception distance (FID) compared to existing ones. Furthermore, numerical results demonstrate that TWAE is competitive to the adversarial model and shows powerful generative ability.

Robust and self-lubricating polyvinyl alcohol tubes with a mucosa-like hierarchical architecture for endotracheal intubation.

Mechanical mismatch between interventional intubation tubes and human tissues often triggers inevitable friction and causes secondary injury to patients during interventional therapy. Herein, we propose a fabrication strategy of a self-lubricating polyvinyl alcohol (PVA) tube by industrial extrusion technology followed by simple infiltration with water. First, biocompatible glycerin was introduced to weaken the intrinsic hydrogen interaction of PVA by new molecular complexation, broadening the gap between the melting and decomposition temperatures and enabling the stable extrusion of the PVA tube. Subsequently, the as-prepared PVA tube was infiltrated with an aqueous solution to construct a strong hydrogen bonding network between PVA and water molecules, forming a soft hydration layer similar to the upper epithelium layer of mucosa. Benefiting from the solid and liquid properties of the hydration layer as well as the small proportion relative to the whole, the infiltrated PVA tube exhibited excellent hydration lubrication behavior and robust mechanical property. The friction coefficient, tensile strength and elongation at break were measured to be 0.05, 26.2 MPa and 654%, respectively, surpassing the values of 0.5, 16.4 MPa and 240% observed in a commercial polyvinyl chloride tube. In vitro, the PVA intubation tube demonstrated significant biocompatibility, and short-term exposure exhibited minimal impacts on the morphology and proliferation of L929 cells. Ultimately, the potential of the infiltrated PVA tube for interventional intubation was demonstrated successfully using an in vivo rabbit model, providing a new idea for the follow-up development of interventional intubation tubes.

Generating bioactive and antiseptic interfaces with nano-silver hydroxyapatite-based coatings by pulsed electrochemical deposition for long-term efficient cervical soft tissue sealing.

Infections related to osseointegrated implants have sparked the interest in studying titanium modification for long-term effective soft tissue sealing. Constructing a silver (Ag)-hydroxyapatite (HA) coating is regarded as an effective strategy for integrating antibiosis with osteanagenesis; however, the outcome for long-term cervical soft tissue sealing in vivo is compromised. It is challenging to construct an Ag-HA coating for long-term efficient soft tissue integration that instills a maximum antibacterial effect while retaining favorable bioactivity to normal gingival mesenchymal cells in vivo. In this study, we employed gradient concentrations of Ag/CaP by pulsed electrochemical deposition to fabricate optimal Ag-HA nanocoatings. By physicochemical analyses, these uniform coatings were mainly formed with spherical metallic and hydroxyapatite nanoparticles, which facilitated good hydrophilicity, moderate rough surfaces and corrosion protection. Furthermore, the nanocoating of the 1.5Ag/CaP group exhibited superior performances in dental follicle cells' proliferation, osteogenic differentiation and antibacterial properties mainly through direct contact inhibition and partially through sustained silver ion release, which resulted in functional cervical soft tissue sealing in beagles lasting for one year. Our investigations provide a feasible strategy to balance the long-term antibacterial demand and bioactive induction around osseointegrated implants for long-term efficient cervical soft tissue sealing.

Biomimetic Peridontium Patches for Functional Periodontal Regeneration.

The unique structure of the periodontium, including the alveolar bone, cementum, and periodontal ligament (PDL), presents difficulties for the regeneration of its intricate organization. Irreversible structural breakdown of the periodontium increases the risk of tooth loosening and loss. Although the current therapies can restore the periodontal hard tissues to a certain extent, the PDL with its high directionality of multiple groups with different orientations and functions cannot be reconstructed. Here, biomimetic peridontium patches (BPPs) for functional periodontal regeneration using a microscale continuous digital light projection bioprinting method is reported. Orthotopic transplantation in the mandibles shows effective periodontal reconstruction. The resulting bioengineered tissues closely resembles natural periodontium in terms of the "sandwich structures," especially the correctly oriented fibers, showing different and specific orientation in different regions of the tooth root, which has never been found in previous studies. Furthermore, after the assessment of clinically functional properties it is found that the regenerative periodontium can achieve stable tooth movement under orthodontic migration force with no adverse consequences. Overall, the BPPs promote reconstruction of the functional periodontium and the complex microstructure of the periodontal tissue, providing a proof of principle for the clinical functional treatment of periodontal defects.

Activation of the CARD8 Inflammasome Requires a Disordered Region.

Several cytosolic pattern-recognition receptors (PRRs) form multiprotein complexes called canonical inflammasomes in response to intracellular danger signals. Canonical inflammasomes recruit and activate caspase-1 (CASP1), which in turn cleaves and activates inflammatory cytokines and gasdermin D (GSDMD), inducing pyroptotic cell death. Inhibitors of the dipeptidyl peptidases DPP8 and DPP9 (DPP8/9) activate both the human NLRP1 and CARD8 inflammasomes. NLRP1 and CARD8 have different N-terminal regions but have similar C-terminal regions that undergo autoproteolysis to generate two non-covalently associated fragments. Here, we show that DPP8/9 inhibition activates a proteasomal degradation pathway that targets disordered and misfolded proteins for destruction. CARD8's N terminus contains a disordered region of ∼160 amino acids that is recognized and destroyed by this degradation pathway, thereby freeing its C-terminal fragment to activate CASP1 and induce pyroptosis. Thus, CARD8 serves as an alarm to signal the activation of a degradation pathway for disordered and misfolded proteins.

Discovery of a Silicon-Containing Pan-Genotype Hepatitis C Virus NS5A Inhibitor.

We describe a study leading to the discovery of compound 11, a pan-genotypic hepatitis C virus (HCV) nonstructural protein 5A (NS5A) inhibitor with excellent potency, metabolic stability, and pharmacokinetics (PK). Compound 11 incorporating a 4-silapiperidine group was discovered by further optimizing our previous lead with a triethylsilyl moiety. It displayed great potency against genotype 1 subtype a (GT1a), -1b, -2a, -3a, -4a, -5a, and -6a with an EC50 range of 0.33-17 pM and improved potency against the resistance-associated variant GT1a_M28T. Pharmacokinetics (PK) study indicated that compound 11 has reasonable PK exposures with a high liver distribution in preclinical animal species (mouse, rat, and dog). The results of a 14 day repeat-dose toxicity study identified the safety of compound 11.

Comparison of Failure and Complication Risks of Porcelain Laminate and Indirect Resin Veneer Restorations: A Meta-Analysis.

PURPOSE: To evaluate and compare the failure and complication risks of porcelain laminate and indirect resin veneer restorations (VRs) by means of a meta-analysis. METHODS: An electronic database search was performed in MEDLINE (PubMed), EMBASE (Ovid), and the Cochrane Central Register of Controlled Trials (CENTRAL) databases, and a gray literature search was performed on OpenGrey. All database searches were completed by March 2018. Two authors individually screened the literature according to the inclusion and exclusion criteria. The quality and risk of bias of the included studies were evaluated using the Newcastle-Ottawa scale (NOS) and the Cochrane Handbook for Systematic Reviews of Interventions (CHSRI). The Mantel-Haenszel method was used to synthesize the data of the included studies. All statistical analyses were performed using the software Stata 14.0, and the results were expressed as risk ratio (RR) with 95% confidence interval (CI). RESULTS: Five studies-two randomized controlled trials (RCTs) and three clinical controlled trials (CCTs)-were included in this review. Of the three CCTs, two were assessed to be low quality, and the third was considered high quality. The two RCTs were rated as unclear risk of bias. The meta-analysis results showed the risk of failure for indirect resin VRs was higher than for porcelain laminate VRs (RR: 0.15, 95% CI: 0.06-0.40; P = .000). Fracture and debonding were the main complications leading to failure. For risk of fracture, an RR of 0.18 (95% CI: 0.04-0.71) and a statistically significant difference (P = .015) were found in favor of porcelain laminate VRs. For risk of debonding, there was no statistically significant difference (P = .108) found between the two types of VRs. The results of the sensitivity analysis (RR: 0.09, 95% CI: 0.02-0.45; P = .004) suggested that this conclusion was reliable. CONCLUSION: The survival rate of porcelain laminate VRs was higher than indirect resin VRs, and the latter had a higher risk of fracture. However, there was no statistically significant difference in the risk of debonding between the two types of VRs. Porcelain laminate VRs have a better prognosis compared to indirect resin VRs, which provides an evidence-based reference for the selection of VRs in clinical practice.

DPP8/9 inhibitors are universal activators of functional NLRP1 alleles.

Intracellular pathogenic structures or activities stimulate the formation of inflammasomes, which recruit and activate caspase-1 and trigger an inflammatory form of cell death called pyroptosis. The well-characterized mammalian inflammasome sensor proteins all detect one specific type of signal, for example double-stranded DNA or bacterial flagellin. Remarkably, NLRP1 was the first protein discovered to form an inflammasome, but the pathogenic signal that NLRP1 detects has not yet been identified. NLRP1 is highly polymorphic, even among inbred rodent strains, and it has been suggested that these diverse NLRP1 alleles may have evolved to detect entirely different stimuli. Intriguingly, inhibitors of the serine proteases DPP8 and DPP9 (DPP8/9) were recently shown to activate human NLRP1, its homolog CARD8, and several mouse NLRP1 alleles. Here, we show now that DPP8/9 inhibitors activate all functional rodent NLRP1 alleles, indicating that DPP8/9 inhibition induces a signal detected by all NLRP1 proteins. Moreover, we discovered that the NLRP1 allele sensitivities to DPP8/9 inhibitor-induced and Toxoplasma gondii-induced pyroptosis are strikingly similar, suggesting that DPP8/9 inhibition phenocopies a key activity of T. gondii. Overall, this work indicates that the highly polymorphic NLRP1 inflammasome indeed senses a specific signal like the other mammalian inflammasomes.

N-terminal degradation activates the NLRP1B inflammasome.

Intracellular pathogens and danger signals trigger the formation of inflammasomes, which activate inflammatory caspases and induce pyroptosis. The anthrax lethal factor metalloprotease and small-molecule DPP8/9 inhibitors both activate the NLRP1B inflammasome, but the molecular mechanism of NLRP1B activation is unknown. In this study, we used genome-wide CRISPR-Cas9 knockout screens to identify genes required for NLRP1B-mediated pyroptosis. We discovered that lethal factor induces cell death via the N-end rule proteasomal degradation pathway. Lethal factor directly cleaves NLRP1B, inducing the N-end rule-mediated degradation of the NLRP1B N terminus and freeing the NLRP1B C terminus to activate caspase-1. DPP8/9 inhibitors also induce proteasomal degradation of the NLRP1B N terminus but not via the N-end rule pathway. Thus, N-terminal degradation is the common activation mechanism of this innate immune sensor.

Design, synthesis and identification of silicon-containing HCV NS5A inhibitors with pan-genotype activity.

Modification of a HCV NS5A inhibitor, ombitasvir, led to the identification of 10d with improved pan-genotype NS5A inhibition and better pharmacokinetic properties. The key structural changes to ombitasvir include bioisosteric replacement of carbon with silicon atom. Compared with ombitasvir, the activity of anti-HCV genotypes (GT 1 to 6) of 10d is increased to some extent, especially the inhibitory activity against genotype 3a and 6a is increased by more than seven times, and the dog's in vivo pharmacokinetics properties were also superior to ombitasvir. Further drug evaluation showed that 10d was similar to ombitasvir on plasma protein binding and liver distribution profiles, with no cytotoxicity and no inhibitory effect on both CYP 450 and hERG ligand binding. However, permeability assay results indicated that 10d was not the substrate of P-gp or BCRP transporter, which is different from that of ombitasvir. The results of a 14-day repeat-dose toxicity study identified no toxicity with 10d. Our findings in preclinical tests suggest that the silicon-containing compound 10d could be worthy of continued study as a potential drug candidate.

Tandem 1,6-addition/cyclization/vinylcyclopropane rearrangement at low temperature under metal-free conditions: an approach to spiro[4.5]cyclohexadienones.

A tandem 1,6-addition/cyclization/vinylcyclopropane rearrangement reaction (VCPR) of vinylogous para-quinone methides at low temperature under metal-free conditions has been disclosed for the first time. This method provides an efficient strategy for the construction of a range of spiro[4.5]cyclohexadienones in good yield, exhibiting good functional group tolerance as well as gram-scale capacity.

Computational investigation of cicada aerodynamics in forward flight.

Free forward flight of cicadas is investigated through high-speed photogrammetry, three-dimensional surface reconstruction and computational fluid dynamics simulations. We report two new vortices generated by the cicada's wide body. One is the thorax-generated vortex, which helps the downwash flow, indicating a new phenomenon of lift enhancement. Another is the cicada posterior body vortex, which entangles with the vortex ring composed of wing tip, trailing edge and wing root vortices. Some other vortex features include: independently developed left- and right-hand side leading edge vortex (LEV), dual-core LEV structure at the mid-wing region and near-wake two-vortex-ring structure. In the cicada forward flight, approximately 79% of the total lift is generated during the downstroke. Cicada wings experience drag in the downstroke, and generate thrust during the upstroke. Energetics study shows that the cicada in free forward flight consumes much more power in the downstroke than in the upstroke, to provide enough lift to support the weight and to overcome drag to move forward.

Synthesis of spiro[2.5]octa-4,7-dien-6-one with consecutive quaternary centers via 1,6-conjugate addition induced dearomatization of para-quinone methides.

An efficient one-pot approach for the synthesis of spiro[2.5]octa-4,7-dien-6-ones by employing para-quinone methides has been developed. The reaction proceeded smoothly in high yields under mild conditions without the use of metals. Moreover, all products obtained herein contained two or three consecutive quaternary centers.

Anti-diabetes constituents in leaves of Smallanthus sonchifolius.

The inhibitory effect of smallanthaditerpenic acids A, B, C and D previously isolated from leaves of Smallanthus sonchifolius (yacon) on alpha-glucosidase were examined and their IC50 were determined to be 0.48 mg/mL, 0.59 mg/mL, 1.00 mg/mL, and 1.17 mg/mL respectively. In addition, a rapid, reliable RP-HPLC method for the analysis of chlorogenic acid, caffeic acid, and smallanthaditerpenic acids A and C in yacon leaves was established, and the variation in their contents in leaves from plants cultivated in different places and collected at different times of the year were compared. The established analytical method for determining smallanthaditerpenic acids A and C, chlorogenic acid and caffeic acid presented good results and could be used as a method for the quality control of S. sonchifolius leaves.