Non-soluble antibacterial polyurethane based on cation mechanism and functionalized by chitosan and heparin azide.

Nowadays, medical polyurethanes with favorable and durable antibacterial properties received more attention, because of avoiding repeated replacement of interventional materials and reducing patients' pain. In this thesis, non-soluble antibacterial polyurethane (NAPU) based on cation antibacterial mechanism was prepared by photo-grafting chitosan azide and heparin azide into polyurethane (PU). -NH3+of chitosan azide absorbed bacteria, inhibiting and breaking their mobility and structures. Heparin azide prevented cations from penetrating bacteria's membranes and inhibited their growth. The results showed that chitosan azide and heparin azide were successfully grafted into PU. The highest antibacterial rate was 92.07%, cytotoxicity grade ranging from 0-1 (RGR standard) and water contact angle exhibiting 60°, attributing to cation antibacterial effect and -OH existing. Tensile strength was up to 23.91 MPa and was suitable for using as medical materials. NAPU with long-lasting coating both possessed antibacterial properties and persistence, which can solve the problem of medical catheters' long-term using.

Regulating the electronic structure by P-doping cobalt-based catalyst for atomic hydrogen mediated electrocatalytic dechlorination.

Electrocatalytic dechlorination by atomic hydrogen (H*) is efficient, but limited by the low efficiency of H* production. Herein, a phosphorus-doped cobalt nitrogen carbon catalyst (Co-NP/C) was prepared, which had high catalytic activity in a wide pH range (3-11). The turnover frequency of Co-NP/C (3.54 min-1) was 1.21-59000 times superior to that of current Pd-based and non-noble metal catalysts (0.00006-2.92 min-1). Co-NP/C significantly enhanced H* generation, which was 1.52, 2.44, and 3.77 times stronger than that of Co-N/C, NP/C, and N/C, respectively, since the introduction of phosphorus was found enhanced the electron density of cobalt and regulated the electron transfer. Co-NP/C showed outstanding catalytic performance after ten cycles and could achieve nearly complete chloramphenicol removal. This regulation method was verified to be effective for other non-noble metal (Fe, Mn, Cu, Ni) phosphorus doped catalysts, proposing a general class for efficient electrochemical dechlorination, which would be of great significance for the elimination of chlorinated organic pollutants.

Generation of rat forebrain tissues in mice.

Interspecies blastocyst complementation (IBC) provides a unique platform to study development and holds the potential to overcome worldwide organ shortages. Despite recent successes, brain tissue has not been achieved through IBC. Here, we developed an optimized IBC strategy based on C-CRISPR, which facilitated rapid screening of candidate genes and identified that Hesx1 deficiency supported the generation of rat forebrain tissue in mice via IBC. Xenogeneic rat forebrain tissues in adult mice were structurally and functionally intact. Cross-species comparative analyses revealed that rat forebrain tissues developed at the same pace as the mouse host but maintained rat-like transcriptome profiles. The chimeric rate of rat cells gradually decreased as development progressed, suggesting xenogeneic barriers during mid-to-late pre-natal development. Interspecies forebrain complementation opens the door for studying evolutionarily conserved and divergent mechanisms underlying brain development and cognitive function. The C-CRISPR-based IBC strategy holds great potential to broaden the study and application of interspecies organogenesis.

Reliability and validity assessment of the Chinese version of the Intrahospital Transport Safety Scale (IHTSS) in intensive care units.

BACKGROUND: Intrahospital transport of critically ill patients is a common practice in intensive care units (ICUs), where patients' safety is constantly challenged in high-intensity and dynamic environments. While Intrahospital Transport Safety Scale (IHTSS) is widely used internationally to evaluate the intrahospital transport safety, it has not been introduced in China. OBJECTIVES: This study aimed to assess the reliability and validity of the Chinese version of the IHTSS scale among critical care nurses in China. METHODS: A cross-sectional study was conducted using a cluster sampling method. A total of 544 critical care nurses from 25 ICUs in 10 tertiary hospitals were recruited. We employed exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to examine the questionnaire's underlying factor structure, ensuring construct validity. Additionally, internal consistency was assessed using Cronbach's alpha coefficient, test-retest reliability, and corrected item-total correlation. RESULTS: The Chinese version of the scale displayed robust psychometric properties, with a Cronbach's α coefficient of 0.976, a split-half reliability of 0.906, and a test-retest reliability of 0.856. EFA revealed a robust four-factor model that accounted for 75.970% of the variance, with the factor loadings of the items ranging from 0.433 to 0.951. CFA indicated a strong model fit, with a chi-square to degrees of freedom ratio (CMIN/DF) of 2.765, comparative fit index (CFI) of 0.943, incremental fit index (IFI) of 0.943, and goodness-of-fit index (GFI) of 0.845, supporting the efficacy of the four-factor model in assessing intrahospital transport safety for critically ill patients. CONCLUSION: The Chinese version of the IHTSS demonstrated favourable reliability and validity among critical care nurses in China, making it a suitable tool for measuring the level of intrahospital transport safety for critically ill patients.

Dearomatization of 3-Aminophenols for Synthesis of Spiro[chromane-3,1'-cyclohexane]-2',4'-dien-6'-ones via Hydride Transfer Strategy-Enabled [5+1] Annulations.

The Sc(OTf)3-catalyzed dearomative [5+1] annulations between readily available 3-aminophenols and O-alkyl ortho-oxybenzaldehydes were developed for synthesis of spiro[chromane-3,1'-cyclohexane]-2',4'-dien-6'-ones. The "two-birds-with-one-stone" strategy was disclosed by the dearomatization of phenols and direct α-C(sp3)-H bond functionalization of oxygen through cascade condensation/[1,5]-hydride transfer/dearomative-cyclization process. In addition, the antifungal activity assay and derivatizations of products were conducted to further enrich the utility of the structure.

Diversity-oriented synthesis of indole-fused scaffolds and bis(indolyl)methane from tosyl-protected tryptamine.

An efficient, diversity-oriented synthesis of indole-1,2-fused 1,4-benzodiazepines, tetrahydro-ß-carbolines, and 2,2'-bis(indolyl)methanes was established starting from tosyl-protected tryptamine. These diverse privileged skeletons were controllably constructed by adjusting different hydride donors and Brønsted acids. A variety of indole-1,2-fused 1,4-benzodiazepines were facilely accessed using benzaldehydes bearing cyclic amines as hydride donors via a cascade N-alkylation/dehydration/[1,5]-hydride transfer/Friedel-Crafts alkylation sequence. The reaction site could be switched when benzaldehydes bearing an alkoxy moiety as hydride donors were used for the generation of tetrahydro-ß-carbolines. On the other hand, the switchable synthesis of 2,2'-bis(indolyl)methanes could be achieved as well by applying p-TsOH·H2O as a catalyst. The reactions feature mild conditions, simple and practical operation, excellent efficiency and the use of EtOH as a green solvent. Using the concept of diversity-oriented, reagent-based synthesis, the inexpensive feedstock tryptamine was efficiently converted to three different types of privileged scaffolds, which facilitates rapid compound library synthesis for accelerating drug discovery.

Preparation and characterizations of antibacterial iodine-containing coatings on pure Ti.

Iodine-containing coatings were prepared on pure Ti surfaces via electrochemical deposition to enhance their antibacterial properties. The factors influencing iodine content were analyzed using an orthogonal experiment. The electrochemically deposited samples were characterized using scanning electron microscopy with energy dispersive spectroscopy and X-ray photoelectron spectroscopy, and their antibacterial properties and cytotoxicity were evaluated. The results showed that changing the deposition time is an effective way to control the iodine content. The iodine content, coating thickness, and adhesion of the samples increased with deposition time. Iodine in the coatings mainly exists in three forms, which are I2, I3-, and pentavalent iodine. For samples with iodine-containing coatings, the antibacterial ratios against E. coli and S. aureus were greater than 90% and increased with increasing iodine content. Although the samples with iodine-containing coatings showed some inhibition of the proliferation of MC3T3-E1 cells, the cell viabilities were all higher than 80%, suggesting that iodine-containing coatings are biosafe.

Controllable Synthesis of N-Heterocycles via Hydride Transfer Strategy-Enabled Formal [5 + 1] and [5 + 2] Cyclizations.

The Brønsted acid-controlled switchable synthesis of indoline-fused tetrahydroquinolines and indole-fused benzazepines was developed through hydride transfer-enabled formal [5 + 1] and [5 + 2] cyclization reactions from indoles and N-alkyl o-aminobenzoketones. Indoline, furanone, and tetrahydroquinoline hybridized pentacyclic products were unprecedentedly accessed via a cascade condensation/hydride transfer/dearomatization-cyclization/deethylation/nucleophilic addition process. In addition, the undeveloped hydride transfer-involved [5 + 2] cyclizations were also realized for direct construction of indole-fused benzazepines.

Controllable Synthesis of N- and O-Containing Heterocycles via Formal [3 + 2] and [5 + 2] Cyclizations.

The controllable synthesis of spirooxindole-dihydrofurans and spirooxindole-benzazepines was developed through formal [3 + 2] and [5 + 2] cyclization reactions from 2-(2-oxoindolin-3-yl)malononitriles and ortho-aminobenzaldehydes, respectively. A variety of spirooxindole-benzazepines were facilely constructed via a furan ring-open-involved hydride transfer/cyclization process. It is noteworthy that the application of the hydride-transfer-involved [5 + 2] cyclization strategy for construction of spirobenzazepines was unprecedented. In addition, the spiro N- and O-containing heterocycles were highly functionalized by amino, amide, and cyano groups, which were conducive to late-stage functionalization.

Underwater Structured Light Stripe Center Extraction with Normalized Grayscale Gravity Method.

The non-uniform reflectance characteristics of object surfaces and underwater environment disturbances during underwater laser measurements can have a great impact on laser stripe center extraction. Therefore, we propose a normalized grayscale gravity method to address this problem. First, we build an underwater structured light dataset for different illuminations, turbidity levels, and reflective surfaces of the underwater object and compare several state-of-the-art semantic segmentation models, including Deeplabv3, Deeplabv3plus, MobilenetV3, Pspnet, and FCNnet. Based on our comparison, we recommend PSPnet for the specific task of underwater structured light stripe segmentation. Second, in order to accurately extract the centerline of the extracted light stripe, the gray level values are normalized to eliminate the influence of noise and light stripe edge information on the centroids, and the weights of the cross-sectional extremes are increased to increase the function convergence for better robustness. Finally, the subpixel-structured light center points of the image are obtained by bilinear interpolation to improve the image resolution and extraction accuracy. The experimental results show that the proposed method can effectively eliminate noise interference while exhibiting good robustness and self-adaptability.

CRH neurons in the lateral hypothalamic area regulate feeding behavior of mice.

Food cues serve as pivotal triggers for eliciting physiological responses that subsequently influence food consumption. The magnitude of response induced by these cues stands as a critical determinant in the context of obesity risk. Nonetheless, the underlying neural mechanism that underpins how cues associated with edible food potentiate feeding behaviors remains uncertain. In this study, we revealed that corticotropin-releasing hormone (CRH)-expressing neurons in the lateral hypothalamic area played a crucial role in promoting consummatory behaviors in mice, shedding light on this intricate process. By employing an array of diverse assays, we initially established the activation of these neurons during feeding. Manipulations using optogenetic and chemogenetic assays revealed that their activation amplified appetite and promoted feeding behaviors, whereas inhibition decreased them. Additionally, our investigation identified downstream targets, including the ventral tegmental area, and underscored the pivotal involvement of the CRH neuropeptide itself in orchestrating this regulatory network. This research casts a clarifying light on the neural mechanism underlying the augmentation of appetite and the facilitation of feeding behaviors in response to food cues. VIDEO ABSTRACT.

Trimetallic MOF-derived CoFeNi/Z-P NC nanocomposites as efficient catalysts for oxygen evolution reaction.

We used sodium hydroxide-mediated approach and tannic acid etching to prepare hollow structured trimetallic MOF-derived CoFeNi/Z-P NC nanocomposites. Remarkably, the resulting CoFeNi/Z-P NC nanocomposites have large specific surface area and mesoporous structure, making their active sites more accessible and mass transfer more effective. More complex trimetallic components provide greater possibilities for further improving electrocatalytic performance. The CoFeNi/Z-P NC nanocomposites demonstrate notable enhancements for the OER, and 10 mA cm-2 current density is achieved at a low overpotential of 244 mV, with a low Tafel slope of 66.2 mV dec-1 and have good stability in alkaline solutions. In addition, as a cathode material for overall alkaline water splitting, CoFeNi/Z-P NC is better than RuO2 with longer cycling stability.

Insights into Electrochemical Dehalogenation by Non-Noble Metal Single-Atom Cobalt with High Efficiency and Low Energy Consumption.

It is critical to discover a non-noble metal catalyst with high catalytic activity capable of replacing palladium in electrochemical reduction. In this work, a highly efficient single-atom Co-N/C catalyst was synthesized with metal-organic frameworks (MOFs) as a precursor for electrochemical dehalogenation. X-ray absorption spectroscopy (XAS) revealed that Co-N/C exhibited a Co-N4 configuration, which had more active sites and a faster charge-transfer rate and thus enabled the efficient removal of florfenicol (FLO) at a wide pH, achieving a rate constant 3.5 and 2.1 times that of N/C and commercial Pd/C, respectively. The defluorination and dechlorination efficiencies were 67.6 and 95.6%, respectively, with extremely low Co leaching (6 µg L-1), low energy consumption (22.7 kWh kg-1), and high turnover frequency (TOF) (0.0350 min-1), demonstrating excellent dehalogenation performance. Spiking experiments and density functional theory (DFT) verified that Co-N4 was the active site and had the lowest energy barrier for forming atomic hydrogen (H*) (ΔGH*). Capture experiments, electron paramagnetic resonance (EPR), electrochemical tests, and in situ Fourier transform infrared (FTIR) proved that H* and direct electron transfer were responsible for dehalogenation. Toxicity assessment indicated that FLO toxicity decreased significantly after dehalogenation. This work develops a non-noble metal catalyst with broad application prospects in electrocatalytic dehalogenation.

Effects of chloride, sulfate, and bicarbonate stress on mortality rate, gill tissue morphology, and gene expression in mandarin fish (Siniperca chuatsi).

The mandarin fish Siniperca chuatsi is a freshwater fish that is endemic to East Asia. To study the different damages and molecular mechanisms caused by different salt (NaCl, Na2SO4, and NaHCO3) on Siniperca chuatsi, the fish were subjected to NaCl, Na2SO4, and NaHCO3 stresses with different concentration for 96 h for mortality assessment, moreover, the fish were exposed to these salt stresses with equal sodium ion concentration (Na+ = 210 mmol/L), then gill morphological changes were observed and gene expression was analyzed by high-throughput transcriptome sequencing and real-time quantitative PCR (qRT-PCR). The results showed that mandarin fish tolerated NaCl and Na2SO4 better than NaHCO3. NaHCO3 stress caused more damage to gill than NaCl and Na2SO4 stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated that differentially expressed genes were enriched in damage and apoptosis upon NaHCO3 stress, whereas they were enriched in energy and immune-related pathways upon NaCl and Na2SO4 stress. Hub genes were different under all three stresses. MAPK pathway genes showed a trend in up-regulated expression under all salt stresses, but the expression patterns varied with time during salt exposure and freshwater recovery stage. Taken together, this study demonstrated the variation in the effects of NaCl, Na2SO4, and NaHCO3 stress on mandarin fish. The MAPK signaling pathway is important for regulating the response to salt stress.

Combination of direct boiling and glass beads increases the purity and accuracy of bacterial DNA extraction.

Extraction of DNA is a key step in molecular biology experiments and important for counting tiny microbial individuals. Direct boiling and mechanical cell lysis like glass beads are two independent physical extraction methods, thus crossing the barriers of thresholds of magnitude in popular reagent kits or traditional spread plate method when non-equilibrium phenomenon is ongoing. The two approaches above were combined to generate a new one. In three typical microbial species, direct boiling with glass beads significantly increased the purity of DNA solution compared with some other methods (p < 0.05). The qPCR results of them were closer to direct microscopy counting than some other methods. Therefore, it provides a new choice in extracting bacterial DNA for specific circumstances.

Chemoselective and diastereoselective construction of 4-alkylidene-tetrahydroquinoline via a redox-neutral vinylogous cascade [1,7]-hydride transfer/6-endo-trig cyclization strategy.

Herein, we disclose a chemoselective and diastereoselective synthesis of the medicinally significant 4-alkylidene-tetrahydroquinoline via a redox-neutral vinylogous cascade condensation/[1,7]-hydride transfer/6-endo-trig cyclization strategy, which features a novel product skeleton, high chemoselectivity and diastereoselectivity, facile introduction of 4-alkylidenyl motifs, employment of α,ß,γ,δ-unsaturated dicyanoalkenes as novel hydride acceptors, and green and metal-free conditions with water as the only by-product. Additionally, the versatility of α,α-dicyanoalkenes has been fully exploited as hydride acceptors and γ-exclusive nucleophiles consecutively for accessing novel heterocyclic skeletons.

Kinetic model derivation for design, building and operation of solid waste treatment unit based on system dynamics and computer simulation.

Solid waste disposal is significantly important to maintaining normal operation of both natural and artificial ecosystems. In this study, a kinetic model of solid waste treatment unit (SWTU) was upfront developed based on microbial ecology, system dynamics, cybernetics and digital simulation, which accurately described the relationships and interactions between solid waste decomposition (SWD) processes and biotic/abiotic factors. Then a specific SWTU prototype was designed and built from this kinetic model. A 370-day experiment demonstrated that SWTU maintained normal operation with robust stability and desired dynamic behaviors, and effectively disposed the solid waste. Therefore, this kinetic model was highly valid due to its high structural and behavioral similarity with the prototype. This research could lay a strong theoretical foundation for further closed-loop control as well as optimization of SWTU, and provide scientific guidance to environmental management as well as sustainable development.

A machine learning-based model for predicting the risk of early-stage inguinal lymph node metastases in patients with squamous cell carcinoma of the penis.

Objective: Inguinal lymph node metastasis (ILNM) is significantly associated with poor prognosis in patients with squamous cell carcinoma of the penis (SCCP). Patient prognosis could be improved if the probability of ILNM incidence could be accurately predicted at an early stage. We developed a predictive model based on machine learning combined with big data to achieve this. Methods: Data of patients diagnosed with SCCP were obtained from the Surveillance, Epidemiology, and End Results Program Research Data. By combing variables that represented the patients' clinical characteristics, we applied five machine learning algorithms to create predictive models based on logistic regression, eXtreme Gradient Boosting, Random Forest, Support Vector Machine, and k-Nearest Neighbor. Model performance was evaluated by ten-fold cross-validation receiver operating characteristic curves, which were used to calculate the area under the curve of the five models for predictive accuracy. Decision curve analysis was conducted to estimate the clinical utility of the models. An external validation cohort of 74 SCCP patients was selected from the Affiliated Hospital of Xuzhou Medical University (February 2008 to March 2021). Results: A total of 1,056 patients with SCCP from the SEER database were enrolled as the training cohort, of which 164 (15.5%) developed early-stage ILNM. In the external validation cohort, 16.2% of patients developed early-stage ILNM. Multivariate logistic regression showed that tumor grade, inguinal lymph node dissection, radiotherapy, and chemotherapy were independent predictors of early-stage ILNM risk. The model based on the eXtreme Gradient Boosting algorithm showed stable and efficient prediction performance in both the training and external validation groups. Conclusion: The ML model based on the XGB algorithm has high predictive effectiveness and may be used to predict early-stage ILNM risk in SCCP patients. Therefore, it may show promise in clinical decision-making.

The Particle Breakage Effect on Abrasive Wear Process of Rubber/Steel Seal Pairs under High/Low Pressure.

Pressure has a significant effect on rubber seal performance in the abrasive environments of drilling. The micro-clastic rocks intruding into the seal interface are prone to fracture, which will change the wear process and mechanism, but this process is not yet known at present. To explore this issue, abrasive wear tests were carried out to compare the failure characteristics of the particles and the variation wear process under high/low pressures. The results show that non-round particles are prone to fracture under different pressures, resulting in different damage patterns and wear loss on the rubber surface. A single particle force model was established at the soft rubber-hard metal interface. Three typical breakage types of particles were analyzed, including ground, partially fractured, and crushed. At high load, more particles were crushed, while at low load, shear failure was more likely to occur at the edges of particles. These different particle fracture characteristics not only change the particle size, but also the state of motion and thus the subsequent friction and wear processes. Therefore, the tribological behavior and wear mechanism of abrasive wear are different at high pressure and low pressure. Higher pressure reduces the invasion of the abrasive particles, but also intensifies the tearing and wear of the rubber. However, no significant differences in damage were found for steel counterpart throughout the wear process under high/low load tests. These results are critical to understanding the abrasive wear of rubber seals in drilling engineering.

Alkyl amines and ethers as traceless hydride donors in [1,5]-hydride transfer cascade reactions.

The use of alkyl amines and ethers as traceless hydride donors in [1,5]-hydride transfer cascade reactions represents a promising strategy that greatly enriches redox-neutral hydride transfer chemistry. This review summarizes the remarkable progress made in this field, and focuses on (1) alkyl amines as traceless hydride donors in cascade [1,5]-hydride transfer/elimination reactions and (2) alkyl ethers as traceless hydride donors in [1,5]-hydride transfer cascade reactions. The reaction mechanisms, features, scope, limitations, and synthetic applications are included, where appropriate. Importantly, its powerful ability in allene synthesis and the combination with [Re]-vinylidene and carbocation chemistries render this strategy attractive enough to inspire chemists to develop colorful reactions for building molecular complexity.