Multi-Stream Fusion Network for Skeleton-Based Construction Worker Action Recognition.

The global concern regarding the monitoring of construction workers' activities necessitates an efficient means of continuous monitoring for timely action recognition at construction sites. This paper introduces a novel approach-the multi-scale graph strategy-to enhance feature extraction in complex networks. At the core of this strategy lies the multi-feature fusion network (MF-Net), which employs multiple scale graphs in distinct network streams to capture both local and global features of crucial joints. This approach extends beyond local relationships to encompass broader connections, including those between the head and foot, as well as interactions like those involving the head and neck. By integrating diverse scale graphs into distinct network streams, we effectively incorporate physically unrelated information, aiding in the extraction of vital local joint contour features. Furthermore, we introduce velocity and acceleration as temporal features, fusing them with spatial features to enhance informational efficacy and the model's performance. Finally, efficiency-enhancing measures, such as a bottleneck structure and a branch-wise attention block, are implemented to optimize computational resources while enhancing feature discriminability. The significance of this paper lies in improving the management model of the construction industry, ultimately aiming to enhance the health and work efficiency of workers.

Homogenization of an acoustic coating with a steel backing subject to an obliquely incident sound.

An effective homogenization model for the acoustic coating of underwater structures is important for reducing the complexity of acoustic scattering computation, which arises from the huge difference in scale between the integral structure and the inhomogeneous microstructure of the coating. The main difficulty of this homogenization arises from the oblique-incidence effect of external sound waves and the interface effect between the coating and backing. In this work, a hybrid method, combining the Bloch wave analysis and retrieval technique, is proposed to characterize the acoustic behavior of the voided coating backed with a steel plate under the action of external sound waves with an arbitrary incident angle. The effectiveness of this method is validated by numerical simulations and comparison with the Bloch wave method and the traditional retrieval method. The influence of the shear-wave effect under obliquely incident sound waves and the coupling effect between the coating and the backing on the homogenization model is investigated in detail, providing a comprehensive understanding of the effective acoustic behavior of the coating.

Structural basis of kindlin-mediated integrin recognition and activation.

Kindlins and talins are integrin-binding proteins that are critically involved in integrin activation, an essential process for many fundamental cellular activities including cell-matrix adhesion, migration, and proliferation. As FERM-domain-containing proteins, talins and kindlins, respectively, bind different regions of ß-integrin cytoplasmic tails. However, compared with the extensively studied talin, little is known about how kindlins specifically interact with integrins and synergistically enhance their activation by talins. Here, we determined crystal structures of kindlin2 in the apo-form and the ß1- and ß3-integrin bound forms. The apo-structure shows an overall architecture distinct from talins. The complex structures reveal a unique integrin recognition mode of kindlins, which combines two binding motifs to provide specificity that is essential for integrin activation and signaling. Strikingly, our structures uncover an unexpected dimer formation of kindlins. Interrupting dimer formation impairs kindlin-mediated integrin activation. Collectively, the structural, biochemical, and cellular results provide mechanistic explanations that account for the effects of kindlins on integrin activation as well as for how kindlin mutations found in patients with Kindler syndrome and leukocyte-adhesion deficiency may impact integrin-mediated processes.

Divergent Iron-Catalyzed Coupling of O-Acyloximes with Silyl Enol Ethers.

An iron-catalyzed coupling reaction of O-acyloximes and O-benzoyl amidoximes with silyl enol ethers is reported. The protocol provides access to functionalized pyrroles, 1,6-ketonitriles, pyrrolines and imidazolines via carbon-centered radicals generated from an initially formed iminyl radical. The intramolecular cyclization and ring-opening processes of the iminyl radical take place preferentially over reactions that proceed through a 1,3-hydrogen transfer, providing insights into iron-catalyzed reactions with oxime derivatives. The cheap and environmentally friendly iron catalyst, the broad substrate scope and the functional group compatibility make this protocol useful for synthesis of valuable nitrogen-containing products.

A redox-economical synthesis of trifluoromethylated enamides with the Langlois reagent.

A redox-economical strategy for the synthesis of trifluoromethylated enamides using copper catalysis is reported. The reaction employs the inexpensive Langlois reagent (CF3SO2Na) and takes place without the need of an external oxidant. The trifluoromethylated enamide products can easily be converted into the corresponding ketone, saturated amide or oxazole.

Unprecedented Oxycyanation of Methylenecyclopropanes for the Facile Synthesis of Benzoxazine Compounds Containing a Cyano Group.

A novel intramolecular oxycyanation of methylenecyclopropanes is reported that proceeds through oxidative cleavage of the N-CN bond and subsequent palladium transfer from N to O of the amide group. A range of substituted benzo[d][1,3]oxazines with a cyano group are readily furnished by this newly developed oxycyanation reaction. Tris(4-trifluoromethylphenyl)phosphine as a ligand has been found to be crucial to effectively promote the transformation with high chemo- and regioselectivity. Moreover, the reaction outcome can be significantly affected by the electronic effect of the acyl group attached to the nitrogen atom of methylenecyclopropanes. When R(3) is a chloromethyl group, the pyrrolo[2,3-b]quinoline derivative is obtained by thermal-induced [3+2] cycloaddition of methylenecyclopropane to the methanediimine intermediate.

Rh(II)-catalyzed [3+2] cycloaddition of 2 H-azirines with N-sulfonyl-1,2,3-triazoles.

Rh(II)-catalyzed intermolecular [3+2] cycloaddition of 2 H-azirines with N-sulfonyl-1,2,3-triazoles is disclosed, in which a series of fully functionalized pyrroles is produced via rhodium azavinyl carbene intermediates. A distinct feature of this reaction is that the azavinyl carbene serves as a [2 C] equivalent, instead of as [1 C] or aza-[3 C] synthons, which have been reported previously in cyclopropanations and [3+n] cycloadditions. Moreover, this methodology has also been successfully applied in the total synthesis of URB447 as well as the formal synthesis of Atorvastatin (Lipitor).

Effect of sintering temperature on the luminescence properties of Ca0.8Ba0.2TiO3:Pr(3+) red-emitting phosphor.

Nanoparticles with the nominal composition Ca0.8Ba0.2Ti03:Pr(3+) were prepared using the sol-gel process. Barium nitrate, 4-hydrated calcium nitrate and praseodymium oxide were used as raw materials. The structural evolution and decomposition processes of the precursors were investigated by powder X-ray diffraction, differential thermal analysis and thermogravimetric analysis. Crystalline Ca0.8Ba0.2Ti03:Pr(3+) could be obtained at 700°C. The photoluminescence properties of the samples were investigated using excitation and emission spectra. Ca0.8Ba0.2Ti03:Pr(3+) nanoparticles showed strong red emission, which could be assigned to the typical (1) D2 →(3) H4 transition of Pr(3+). Furthermore, the study found that sintering temperature and the introduction of Ba(2+) influence the decay time of persistent luminescence.

(DHQ)2AQN-catalyzed asymmetric substitution of isatin-derived hydrazones with O-Boc-protected Morita-Baylis-Hillman adducts: A strategy for synthesizing enantioenriched azo compounds incorporating an oxindole scaffold.

The first example for the preparation of enantioenriched azo compounds from hydrazones and Morita-Baylis-Hillman adducts has been developed, affording azo compounds incorporating an oxindole scaffold in up to 91% yield along with a 93% ee value under the catalysis of (DHQ)2AQN.

The emerging role of SARS-CoV-2 nonstructural protein 1 (nsp1) in epigenetic regulation of host gene expression.

Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes widespread changes in epigenetic modifications and chromatin architecture in the host cell. Recent evidence suggests that SARS-CoV-2 nonstructural protein 1 (nsp1) plays an important role in driving these changes. Previously thought to be primarily involved in host translation shutoff and cellular mRNA degradation, nsp1 has now been shown to be a truly multifunctional protein that affects host gene expression at multiple levels. The functions of nsp1 are surprisingly diverse and include not only the downregulation of cellular mRNA translation and stability, but also the inhibition of mRNA export from the nucleus, the suppression of host immune signaling, and, most recently, the epigenetic regulation of host gene expression. In this review, we first summarize the current knowledge on SARS-CoV-2-induced changes in epigenetic modifications and chromatin structure. We then focus on the role of nsp1 in epigenetic reprogramming, with a particular emphasis on the silencing of immune-related genes. Finally, we discuss potential molecular mechanisms underlying the epigenetic functions of nsp1 based on evidence from SARS-CoV-2 interactome studies.

Modulator-assisted solvent-free synthesis of amorphous zirconium terephthalate catalyst for efficient oxidative desulfurization.

Oxidative desulfurization (ODS) emerges as a critical player in enhancing efficient fuel desulfurization and promoting sustainable clean energy. Metal-organic frameworks (MOFs) show great potential as ODS catalysts because of their exceptional porosity and versatility. This study explores the use of amorphous metal-organic frameworks (aMOFs), which combine MOFs' structural advantages with unique properties of amorphous materials, to enhance catalytic efficiency in ODS. Traditional methods for synthesizing MOFs rely on solvent-thermal or solvent-free methods, each with limitations in environmental impact or scalability. To address this, we introduce a novel strategy utilizing a small quantity of benzoic acid (BA) modifier to facilitate the solvent-free, one-pot, mechanical synthesis of amorphous zirconium terephthalate (GU-2BA-3h). The resulting GU-2BA-3h demonstrates exceptional ODS performance, efficiently removing 1000 ppm of dibenzothiophene (DBT) in just 6 min at 60 °C. Amorphous GU-2BA-3h features an expanded external surface area, increased acidic sites, and exceptional stability, resulting in a high turnover frequency (19.6 h-1) and outstanding catalytic activity (53.2 mmol g-1 h-1), establishing it as a highly efficient ODS catalyst. This remarkable performance arises from the formation of dangling carboxyl groups and active metal sites due to the competitive coordination of benzoic acid with the linker. Experimental evidence confirms that these carboxyl groups and exposed Zr-OH sites interact with oxidants, generating hydroxyl radicals that effectively eliminate sulfur-containing compounds. Furthermore, the methodology exhibits universality in constructing amorphous Zr-based MOFs, and provides an eco-friendly, cost-effective route for efficient ODS catalyst production.

Sequential co-reduction of nitrate and carbon dioxide enables selective urea electrosynthesis.

Despite the recent achievements in urea electrosynthesis from co-reduction of nitrogen wastes (such as NO3-) and CO2, the product selectivity remains fairly mediocre due to the competing nature of the two parallel reduction reactions. Here we report a catalyst design that affords high selectivity to urea by sequentially reducing NO3- and CO2 at a dynamic catalytic centre, which not only alleviates the competition issue but also facilitates C-N coupling. We exemplify this strategy on a nitrogen-doped carbon catalyst, where a spontaneous switch between NO3- and CO2 reduction paths is enabled by reversible hydrogenation on the nitrogen functional groups. A high urea yield rate of 596.1 µg mg-1 h-1 with a promising Faradaic efficiency of 62% is obtained. These findings, rationalized by in situ spectroscopic techniques and theoretical calculations, are rooted in the proton-involved dynamic catalyst evolution that mitigates overwhelming reduction of reactants and thereby minimizes the formation of side products.

Improved dye sensitized solar cell performance in larger cell size by using TiO2 nanotubes.

Typical dye sensitized solar cells (DSSCs) exhibit a severe reduction of power conversion efficiency when the cell size is increased. In order to cope with this issue, we have investigated the use of anodized TiO(2) nanotubes on Ti foil in combination with the standard TiO(2) nanoparticle paste coated anode structure. The presence of nanotubes in the anode structure enabled a significant mitigation of the size-dependent deterioration of the DSSC performance, with a trend of much milder decrease of the efficiency as a function of the cell dimension up to 9 cm(2). The observed improvement is partly attributed to the elimination of fluorine-doped tin oxide glass in the anode structure, as well as the enhanced charge collection via the nanotube coated Ti substrate, resulting from enhanced mechanical and electrical connections and possibly improved light trapping. The introduction of TiO(2) nanotubes on the Ti foil substrate led to a substantial improvement of the J(sc) current density.

Construction of C(CO)-C(CO) Bond via NHC-Catalyzed Radical Cross-Coupling Reaction.

A C(sp2)-C(sp2) bond can be constructed via a photoredox/N-heterocyclic carbene (NHC)-cocatalyzed radical cross-coupling reaction, which provides a complementary strategy to classic electron pair processes. The present protocol represents the first example of an NHC-catalyzed two-component radical cross-coupling reaction involving C(sp2)-centered radical species. The decarboxylative acylation of oxamic acid with acyl fluoride was conducted under mild conditions and allowed the preparation of a variety of useful α-keto amides, including sterically congested ones.

The substrate selectivity of papain-like proteases from human-infecting coronaviruses correlates with innate immune suppression.

Coronaviruses that can infect humans can cause either common colds (HCoV-NL63, HCoV-229E, HCoV-HKU1, and HCoV-OC43) or severe respiratory symptoms (SARS-CoV-2, SARS-CoV, and MERS-CoV). The papain-like proteases (PLPs) of SARS-CoV, SARS-CoV-2, MERS-CoV, and HCoV-NL63 function in viral innate immune evasion and have deubiquitinating (DUB) and deISGylating activities. We identified the PLPs of HCoV-229E, HCoV-HKU1, and HCoV-OC43 and found that their enzymatic properties correlated with their ability to suppress innate immune responses. A conserved noncatalytic aspartic acid residue was critical for both DUB and deISGylating activities, but the PLPs had differing ubiquitin (Ub) chain cleavage selectivities and binding affinities for Ub, K48-linked diUb, and interferon-stimulated gene 15 (ISG15) substrates. The crystal structure of HKU1-PLP2 in complex with Ub revealed binding interfaces that accounted for the unusually high binding affinity between this PLP and Ub. In cellular assays, the PLPs from the severe disease-causing coronaviruses strongly suppressed innate immune IFN-I and NF-κB signaling and stimulated autophagy, whereas the PLPs from the mild disease-causing coronaviruses generally showed weaker effects on immune suppression and autophagy induction. In addition, a PLP from a SARS-CoV-2 variant of concern showed increased suppression of innate immune signaling pathways. Overall, these results demonstrated that the DUB and deISGylating activities and substrate selectivities of these PLPs differentially contribute to viral innate immune evasion and may affect viral pathogenicity.

Yb(NTf2)3-catalyzed [3 + 3] cycloaddition between isatin ketonitrones and cyclopropanes to construct novel spiro[tetrahydro-1,2-oxazine]oxindoles.

Yb(NTf(2))(3)-catalyzed [3 + 3] cycloaddition between isatin ketonitrones and cyclopropanes is described. A variety of spiro[tetrahydro-1,2-oxazine]oxindoles were obtained in moderate to good yields along with good regioselectivities. This is the first example of the intermolecular [3 + 3] cycloaddition between ketone-derived nitrones and cyclopropanes.

[Measurement of purines and uric acid simultaneous in meat with high performance liquid chromatographys].

OBJECTIVE: To determinate adenine, guanine, hypoxanthine, xanthine and uric acid simultaneously in meat, a reversed-phase high performance liquid chromatography (HPLC) was developed. METHODS: The meat were hydrolyzed with perchloric acid 10% (v/v) in boiling water for 60 mm. After the hydrolysate was adjusted to pH 4, centrifuge , and filtrated with a 0.45 mirom membrane, the supernatants were separated on an Agilent ZORBAX Eclipse XDB-C18 column (250 mm x 4.6 mm i.d., 5 microm) at 25 degrees C with a mobile phase of 7 x 10(-3) mol/L KH2PO4-H3P04(pH 4.0) ,a flow rate of 1.0 ml/ mm, and UV detection at 254 nm. RESULTS: Each component in the corresponding concentration range showed a good linear relation with its peak area, correlation coefficient r > 0.9999, recovery was 90.0%-107. 5%, RSD was 1.7%-13.3%. In addition to containing four kinds of purines, there was quite amount of uric acid (about 133.7 -86.2 pug/g) in the mentioned meat. The ratio of uric acid to total purine and uric acid was about 7%. The content of total purine in chicken was (1759.3 +/- 64.6) microg/g higher than in rabbit, mutton, pork and beef (1440-1000 microg/g). CONCLUSION: The validated method is simple, rapid, accurate and reliable to the determination of purines and uric acid in meat.

Comparison of perioperative indicators, treatment efficacy, and postoperative complications between tonsillotomy and tonsillectomy for children with obstructive sleep apnea hypopnea syndrome.

OBJECTIVE: This study aimed to compare the perioperative indicators, treatment efficacy, and postoperative complications between tonsillotomy and tonsillectomy for children with obstructive sleep apnea hypopnea syndrome. METHODS: A total of 134 children with obstructive sleep apnea hypopnea syndrome were divided into tonsillotomy group (n=66) and tonsillectomy group (n=68). The tonsillotomy group received tonsillotomy treatment with a power cutter, while the tonsillectomy group received tonsillectomy treatment. The perioperative indicators, treatment efficacy, and postoperative complications were compared between the two groups. RESULTS: There was no significant difference in operative time between the two groups (p>0.05), with significant difference in amount of blood loss, postoperative Visual Analogue Scale score, food intake amount, and general diet-taking starting time between the two groups (p<0.05). The total effective rate of treatment had no significant difference between the two groups (p>0.05). There was significant difference in postoperative bleeding, upper respiratory tract infection, and pharyngeal scar grade between the two groups (p<0.05). CONCLUSIONS: Compared with tonsillectomy treatment for children with obstructive sleep apnea hypopnea syndrome, tonsillotomy treatment is more beneficial to optimize the perioperative indicators, relieve the postoperative pain, facilitate the postoperative recovery, and reduce the postoperative complications, which is worthy of clinical promotion.

Highly efficient catalytic reduction of 4-nitrophenol and organic dyes by ultrafine palladium nanoparticles anchored on CeO2 nanorods.

Uniformly dispersed Pd nanoparticles on certain supports exhibit exceptional catalytic performance toward various environmental applications. In this work, ultrafine Pd nanoparticles anchored on CeO2 nanorods were synthesized via an absorption-in situ reduction method. The activity of the CeO2/Pd nanocomposites was systematically investigated toward reduction of 4-nitrophenol (4-NP) and organic dyes including methyl blue, rhodamine B, methyl orange, and Congo red. The results indicated that the CeO2/Pd nanocomposites with different weight ratios of Pd nanoparticles (10.23 wt%, 11.01 wt%, and 14.27 wt%) can almost completely reduce 4-NP with a rate constant of 3.31×10-1, 3.22×10-1, and 2.23×10-1 min-1. Besides, the 10.23 wt% CeO2/Pd nanocomposites exhibit remarkable enhanced catalytic activity toward reduction of organic dyes. The catalysts display ideal stability after being used for three times for the reduction of 4-NP. We believe that our strategy demonstrated here offers insights into the design and fabrication of novel Pd-based nanocomposites for various heterogeneous catalysis applications.

Interaction between DLC-1 and SAO-1 facilitates CED-4 translocation during apoptosis in the Caenorhabditis elegans germline.

Apoptosis is one of the major forms of programmed cell death, and it serves vital biological functions in multicellular animal and plant cells. The core mechanism of apoptosis is highly conserved in metazoans, where the translocation of CED-4/Apaf-1 from mitochondria to the nuclear membrane is required to initiate and execute apoptosis. However, the underlying molecular mechanisms of this translocation are poorly understood. In this study, we showed that SAO-1 binds DLC-1 and prevents its degradation to promote apoptosis in C. elegans germ cells. We demonstrated that SAO-1 and DLC-1 regulate CED-4/Apaf-1 nuclear membrane accumulation during apoptosis. Isothermal titration calorimetry-based assay and high-resolution crystal structure analysis further revealed that SAO-1 interacted with DLC-1 to form a 2:4 complex: each of the two ß-sheets in the SAO-1 peptide interacted with two DLC-1 dimers. Point mutations at the SAO-1-DLC-1 binding interface significantly inhibited apoptotic corpse formation and CED-4 nuclear membrane accumulation within C. elegans germ cells. In conclusion, our study provides a new perspective on the regulation of CED-4-mediated apoptosis.