Community ecological response to polycyclic aromatic hydrocarbons in Baiyangdian Lake based on an ecological model.

The dynamic response of a single population to chemicals can be represented by a Weibull function. However, it is unclear whether the overall response can still be represented in this manner when scaled up to the community level. In this study, we investigated the responses of biological communities to polycyclic aromatic hydrocarbons by using an ecological model of Baiyangdian Lake in northern China. The community dynamics process was divided into the following three stages. In the first stage, toxicity, played a dominant role and strong, medium, and weak species responses were observed according to the toxicity sensitivity. In the second stage, the dynamic process was dominated by the interaction strength with three alternative dynamic pathways comprising of direct response, no response, or inverse response. In the third stage, the toxicity was again dominant, and the biomasses of all species decreased to extinction. The toxicological dynamics were far more complex at the community level than those at the single species level and they were also influenced by the interaction strength as well as toxicity. The toxicological dynamic process in the community was constantly driven by the competing effects of these two forces. In addition to the total biomass, the interaction strength was identified as a suitable community-level signal because it exhibited good indicator properties regarding ecosystem steady-state transitions. However, we found that food web stability indicators were not suitable for use as community-level signals because they were not sensitive to changes in the ecosystem state. Some ecological management suggestions have been proposed, including medium to long-term monitoring, and reduction of external pollution loads and bioindicators. The results obtained in this study increase our understanding of how chemicals interfere with community dynamics, and the interaction strength and total biomass were identified as useful holistic indicators.

A retrospective study of 12,538 internal conical connection implants focused on the long-term integrity of implant-abutment complexes.

OBJECTIVE: To evaluate the long-term integrity of implant-abutment complexes in implant systems with two internal conical angles. MATERIAL AND METHODS: 12,538 bone-level implants of two systems placed between January 2012 and December 2018 were retrospectively analyzed. Cumulative abutment/implant fracture rates in systems with larger (LA, 7.5°) and smaller (SA, 5.7°) internal conical angles were estimated using the Kaplan-Meier analysis and compared between groups. The association between implant systems and jammed abutment retrievability was evaluated by multivariable generalized estimating equation logistic regression modeling. RESULTS: For LA, the 8-year cumulative incident rate was 0.10% (95% confidence interval (CI): 0-0.24%) for implant fracture and 0.26% (95% CI: 0.11%-0.41%) for abutment fracture, demonstrating a significant difference in gender (p = .03), implant diameter (p = .01), jaw (p = .006), and antagonist tooth (p < .001). For SA, the 8-year cumulative incident rate was 0.38% (95% CI: 0-0.79%) for implant fracture and 2.62% (95% CI: 0.05%-5.13%) for abutment fracture, which was influenced by implant diameter (p < .001) and site (p = .03). The cumulative implant/abutment fracture rate was lower for LA implants, particularly for LA implant-supported single crowns (SCs) (p < .05). The abutment-retrieval success rate was 92.9% for LA and 57.1% for SA (p = .055). CONCLUSION: LA implants exhibited a lower incidence of fracture in abutment-implant complexes and a relatively higher retrievability success rate for jammed abutments.

Indirect effects of carbon taxes on water conservation: A water footprint analysis for China.

Water scarcity is a severe problem for regional environmental protection and socioeconomic development, and water footprints are effective tools for evaluating the magnitude of the water scarcity. However, water is closely intertwined with energy. Carbon taxes are an essential policy tool for managing energy use, and could therefore indirectly change the water footprint. Previous research on water footprints has revealed the historical characteristics of water footprints, but has not predicted how these characteristics would change under a carbon tax. Identifying the indirect impacts of carbon taxes on water footprints could therefore offer important information to support more effective energy and water policies. In the present study, we explored the impacts of carbon taxes on water footprints. We established a computable general equilibrium model to predict the effects of carbon taxes on the socioeconomic system, and adopted an input-output model to account for changes in the water footprint. We then used China as a case study. We found that a carbon tax could reduce the total water footprint, even though the water footprint for primary industries increased. In addition, the tax could decrease the virtual water content, and the reduction of virtual water content is the greatest for the secondary industries.

Oxidative Coupling of Diazo and NH4I: A Route to Primary Oxamates and α-Ketoamides.

A simple and efficient method has been developed for the preparation of primary oxamates and α-ketoamides through the oxidative coupling of diazo compounds and NH4I. Under the optimized reaction conditions, a range of diazoesters and α-diazoketones was explored, and the corresponding products were obtained in moderate to good yields. This protocol is metal-free, is performed under mild conditions, has a wide substrate scope, and offers operational simplicity.

Ecological risk assessment of petroleum hydrocarbons on aquatic organisms based on multisource data.

From the perspective of ecological risk, this study uses a multisource data method to search for global data, uses the acute and chronic ratio method to process the data, uses the species-sensitive distribution method to evaluate the ecological risk that petroleum hydrocarbons pose to aquatic organisms, and evaluates the ecological risk of the water environment in five Chinese water bodies. The results are as follows. First, in an aquatic ecosystem, the toxicological effects of petroleum hydrocarbons were found to be more obvious on consumers, and the sensitivity of fish was found to be higher than that of crustaceans. Second, the acutely lethal effects of petroleum hydrocarbons, fluorene, and benzo [a] pyrene on aquatic ecosystems were fitted by using the documentary method of multisource data collection and a Log-logistic curve. Third, in the case study evaluation of five Chinese water bodies, the ecological risks of polycyclic aromatic hydrocarbons were ranked (from low to high) as fluorene < benzo [a] pyrene. The ecological risk values of benzo [a] pyrene were all greater than 1. These risks should not be underestimated, and prevention and control work should be performed.

Chlorhexidine gluconate transparent dressing does not decrease central line-associated bloodstream infection in critically ill patients: A randomized controlled trial.

BACKGROUND: Central line-associated blood stream infections are accompanied by increased mortality and health care costs. The application of different types of dressings in infection control has not been fully investigated to date. AIM: To assess the effects of two different dressing types on central line-associated bloodstream infections. METHODS: A randomized, nonblinded, controlled trial was conducted. Central lines were randomly allocated to intervention (chlorhexidine gluconate transparent dressing, n = 259) and control groups (standard dressing, n = 215). The central line-associated bloodstream infection rate was assessed. RESULTS: A statistically nonsignificant difference was noted in the overall central line-associated bloodstream infection rates between the two groups. The frequency of dressing changes in the patients with the chlorhexidine gluconate transparent dressing was significantly lower than that in the patients with a standard dressing. The predominant type of infectious microorganisms isolated from the central line-associated bloodstream infection episodes was Gram-negative bacteria (57.2%). Gram-positive bacteria and fungi were noted at lower percentages (28.5% and 14.3%, respectively). CONCLUSION: The use of a chlorhexidine gluconate transparent dressing does not decrease the central line-associated bloodstream infection rate, although it decreases the frequency of dressing changes so may save nursing time.

Reliability and validity of the Chinese version of the Breathlessness Beliefs Questionnaire.

The aim of this article is to evaluate the reliability and validity of the Chinese version of the Breathlessness Beliefs Questionnaire (BBQ) for use among patients with respiratory diseases in China. The BBQ is an instrument for assessing specific dyspnoea-related fears and may have predictive value for chronic obstructive pulmonary disease outcomes beyond general anxiety measures. This instrument has not previously been translated into Chinese or tested in mainland China. This was a cross-sectional validation study with a 1-week test of reproducibility. A total of 252 Chinese patients with respiratory diseases recruited from pulmonary outpatient and inpatient departments completed the BBQ. Demographic characteristics, pulmonary function and degree of dyspnoea were also measured. Cronbach's α was 0.82 for the total BBQ score; 0.72 for the somatic focus subscale and 0.73 for the activity avoidance subscale. Test-retest reliability was satisfactory, with intraclass correlation coefficient scores for the BBQ overall and for each subscale ranging from 0.96 to 0.98 ( p < 0.001). After exploratory factor analyses, the Chinese version of the BBQ was found to be similar to the original Dutch version. The Chinese version of the BBQ is a reliable tool to assess dyspnoea-related fear in patients with respiratory diseases in mainland China.

In Situ Generation of Quinolinium Ylides from Diazo Compounds: Copper-Catalyzed Synthesis of Indolizine.

The Cu-catalyzed three-component reaction between quinolines, diazo compounds, and alkenes has been established for direct construction of indolizine derivatives via quinolinium ylides. This methodology is distinguished by the use of a commercially inexpensive catalyst and readily available starting materials, wide substrate scope, and operational simplicity.

Comparison of intraoperative neurophysiologic monitoring outcomes between cervical and thoracic spine surgery.

PURPOSE: The objective is to compare the intraoperative monitoring (IOM) outcomes between degenerative cervical and thoracic spine decompression surgery. METHOD: A total of 97 patients with cervical compression myelopathy (CCM) and 75 patients with thoracic compression myelopathy (TCM) were prospectively collected between December 2012 and June 2015 in our spine center. Somatosensory-evoked potentials (SSEP) and motor-evoked potentials (MEP) were used for IOM. The postoperative neurologic status of each patient was assessed immediately after surgery. And the IOM and neurological outcomes were mainly analyzed in this study. RESULTS: Under the same alarm criteria, the IOM changes present significant difference between the cervical and thoracic surgery. During the patients with monitoring alerts, the MEPs usually manifest as sudden loss in TCM whereas the gradual loss in CCM. And there were three permanent neurologic injuries in the thoracic cases, but none in cervical cases. CONCLUSION: The IOM loss between CCM and TCM patients present obvious difference and the sudden MEPs loss associated with spinal decompression need to be taken seriously especially in TCM.

[3 + 2] cycloaddition and subsequent oxidative dehydrogenation between alkenes and diazo compounds: a simple and direct approach to pyrazoles using TBAI/TBHP.

A novel Bu4NI-catalyzed pyrazole formation reaction is well described via sequential [3 + 2] cycloaddition and oxidative dehydrogenation reactions using TBHP as the primary oxidant. In comparison with previous cases toward pyrazoles from alkenes and diazo compounds, alkenes without a pre-organized leaving group were applied in this transformation. In addition, this methodology was distinguished by its broad substrate scope, commercially available inexpensive starting materials, high atom economy and operational simplicity.

A Cu-catalyzed four-component cascade reaction to construct ß-ester-γ-amino ketones.

Herein, a novel Cu-catalyzed four-component cascade reaction, which encompasses styrenes, diazo compounds, amines, and tert-butyl hydroperoxide (TBHP), was developed for the synthesis of ß-ester-γ-amino ketones. Mechanistically, this transformation was initiated by the interception of an electrophilic Cu-based carbene with nucleophilic α-aminoalkyl radicals, followed by a radical cascade process and an ionic Kornblum-DeLaMare reaction. The methodology was also distinguished by its wide substrate scope, easily available starting materials, and operational simplicity.

Emotion generation method in online physical education teaching based on data mining of teacher-student interactions.

Different from conventional educational paradigms, online education lacks the direct interplay between instructors and learners, particularly in the sphere of virtual physical education. Regrettably, extant research seldom directs its focus toward the intricacies of emotional arousal within the teacher-student course dynamic. The formulation of an emotion generation model exhibits constraints necessitating refinement tailored to distinct educational cohorts, disciplines, and instructional contexts. This study proffers an emotion generation model rooted in data mining of teacher-student course interactions to refine emotional discourse and enhance learning outcomes in the realm of online physical education. This model includes techniques for data preprocessing and augmentation, a multimodal dialogue text emotion recognition model, and a topic-expanding emotional dialogue generation model based on joint decoding. The encoder assimilates the input sentence into a fixed-length vector, culminating in the final state, wherein the vector produced by the context recurrent neural network is conjoined with the preceding word's vector and employed as the decoder's input. Leveraging the long-short-term memory neural network facilitates the modeling of emotional fluctuations across multiple rounds of dialogue, thus fulfilling the mandate of emotion prediction. The evaluation of the model against the DailyDialog dataset demonstrates its superiority over the conventional end-to-end model in terms of loss and confusion values. Achieving an accuracy rate of 84.4%, the model substantiates that embedding emotional cues within dialogues augments response generation. The proposed emotion generation model augments emotional discourse and learning efficacy within online physical education, offering fresh avenues for refining and advancing emotion generation models.

DON6D: a decoupled one-stage network for 6D pose estimation.

The six-dimensional (6D) pose object estimation is a key task in robotic manipulation and grasping scenes. Many existing two-stage solutions with a slow inference speed require extra refinement to handle the challenges of variations in lighting, sensor noise, object occlusion, and truncation. To address these challenges, this work proposes a decoupled one-stage network (DON6D) model for 6D pose estimation that improves inference speed on the premise of maintaining accuracy. Particularly, since the RGB images are aligned with the RGB-D images, the proposed DON6D first uses a two-dimensional detection network to locate the interested objects in RGB-D images. Then, a module of feature extraction and fusion is used to extract color and geometric features fully. Further, dual data augmentation is performed to enhance the generalization ability of the proposed model. Finally, the features are fused, and an attention residual encoder-decoder, which can improve the pose estimation performance to obtain an accurate 6D pose, is introduced. The proposed DON6D model is evaluated on the LINEMOD and YCB-Video datasets. The results demonstrate that the proposed DON6D is superior to several state-of-the-art methods regarding the ADD(-S) and ADD(-S) AUC metrics.

Ecological threshold of phosphorus load in Baiyangdian Lake based on a PCLake model and ecological network analysis.

Ecological thresholds are a useful indicator for implementing ecological management. Many studies determine the thresholds for nutrient loads in lakes based on the maximum allowable concentration of chlorophyll a (Chla), although this neglects the overall performance of the ecosystem. A PCLake model of Baiyangdian (BYD) Lake in northern China was constructed with six ecological network analysis (ENA) indicators that characterized the ecosystem function, system maturity, and food web structure to quantify the overall status of the BYD ecosystem. To my knowledge, this is the first study on the system level responses of the BYD Lake to phosphorus load interference. Different phosphorus load scenarios were designed to simulate the ecological responses of BYD Lake. The simulated results were employed to calculate the ENA indicators. Ecological thresholds were determined through the driving response relationship between the phosphorus load gradient and the ENA indicators. The results show a non-linear transition response of ENA indicator under phosphorus load gradient. As phosphorus load increases, D/H, SOI, and FCI decreases while A/DC, TPP/TR, and TPP/TB increases. This indicates that the overall structure and function of the ecosystem will deteriorate if phosphorus load increases. The phosphorus load thresholds for the overall performance of BYD Lake were 0.50-1.32 mg m-2 d-1, slightly wider than that of Chla (0.53-1.26 mg m-2 d-1). The model results clearly indicate that there is a time-lag phenomenon at the switch points in the response of ENA indicators compared to that of single functional group. In addition, the A/DC, TPP/TR, SOI, and FCI present more time-lag than that of other ENA indicators. These time-lag effects provide a particular opportunity for biodiversity conservation. Therefore, a possible management strategy is proposed to combine system-level and function group-level thresholds, with the ENA-based threshold as the bottom line and the phytoplankton's threshold as the early-warning indicator. This design is expected to be more precise and efficient, by exploiting the advantages of two thresholds, and may benefit for ecological management practices.

Self-sustained and Insulated Radiative/Evaporative Cooler for Daytime Subambient Passive Cooling.

Passive cooling technologies are one of the promising solutions to the global energy crisis due to no consumption of fossil fuels during operation. However, the existing radiative and evaporative coolers still have problems achieving daytime subambient cooling while maintaining evaporation over the long term. Here, we propose a self-sustained and insulated radiative/evaporative cooler (SIREC), which consists of a porous polyethylene film (P-PE) at the top, an air layer in the middle, and poly(vinyl alcohol) hydrogel with lithium bromide (PLH) at the bottom. In particular, the P-PE shows high solar reflectance (R̅solar = 0.91) and long-wave infrared transmittance (τ̅LWIR = 0.92), which reflects sunlight while enhancing the direct radiative heat transfer between outer space and PLH (ε̅LWIR = 0.96) for sky radiative cooling. In addition, the desirable vapor permeability (579 s m-1) of the P-PE also results in good compatibility with PLH for evaporative cooling (EC). Moreover, the PLH's ability to harvest atmospheric water at night provides self-sustainment for daytime EC. The air layer between P-PE and PLH further enhances the subambient cooling performance of the SIREC. These findings indicate promising prospects for the integration of passive cooling technologies.

Efficient roxarsone degradation by low-dose peroxymonosulfate with the activation of recycling iron-base composite material: Critical role of electron transfer.

Pollutant degradation via electron transfer based on advanced oxidation processes (AOPs) provides an economical and energy-efficient method for pollution control. In this study, an iron-rich waste, heating pad waste (HPW), was recycled as a raw material, and a strong magnetic catalyst (Fe-HPW) was synthesized at high temperature (900 °C). Results showed that in the constructed Fe-HPW/PMS system, effective roxarsone (ROX) degradation and TOC removal (72.54%) were achieved at a low-dose of oxidant (PMS, 0.05 mM) and catalyst (Fe-HPW, 0.05 g L-1), the ratio of PMS to ROX was only 2.5:1. In addition, the released inorganic arsenic was effectively removed from the solution. The analysis of the experimental results showed that ROX was effectively degraded by forming PMS/catalyst surface complexes (Fe-HPW-PMS*) to mediate electron transfer in the Fe-HPW/PMS system. Besides, this system performed effective ROX degradation over a wide pH range (pH=3-9) and showed high resistance to different water parameters. Overall, this study not only provides a new direction for the recycling application of HPW but also re-emphasizes the neglected nonradical pathway in advanced oxidation processes.

Structure and function of type IV IRES in picornaviruses: a systematic review.

The Picornaviridae is a family of icosahedral viruses with single-stranded, highly diverse positive-sense RNA genomes. Virions consist of a capsid, without envelope, surrounding a core of RNA genome. A typical genome of picornavirus harbors a well-conserved and highly structured RNA element known as the internal ribosome entry site (IRES), functionally essential for viral replication and protein translation. Based on differences in their structures and mechanisms of action, picornaviral IRESs have been categorized into five types: type I, II, III, IV, and V. Compared with the type IV IRES, the others not only are structurally complicated, but also involve multiple initiation factors for triggering protein translation. The type IV IRES, often referred to as hepatitis C virus (HCV)-like IRES due to its structural resemblance to the HCV IRES, exhibits a simpler and more compact structure than those of the other four. The increasing identification of picornaviruses with the type IV IRES suggests that this IRES type seems to reveal strong retention and adaptation in terms of viral evolution. Here, we systematically reviewed structural features and biological functions of the type IV IRES in picornaviruses. A comprehensive understanding of the roles of type IV IRESs will contribute to elucidating the replication mechanism and pathogenesis of picornaviruses.

A chirality indicator for the surfaces of the silica nanotubes.

The chirality of the silicas attracted much attention, due to their potential applications in asymmetric catalysis and enantioseparation. However, their chirality has not been well understood. Herein, a chirality indicator for the surfaces of the silica nanotubes was developed. The helical silica nanotubes were prepared through a sol-gel transcription approach. The handedness was controlled by that of the self-assemblies of the low-molecular-weight amphiphiles. 4-Triethoxysilyl-1,1'-biphenyl (TSB) was modified on the surfaces of silica nanotubes through covalent bonds. The circular dichroism (CD) spectra of the TSB-modified silica nanotubes indicated that the chirality of silica surfaces could be transferred to the twist of the biphenyl rings. The origin of these CD signals was characterized using time-dependent density functional theory.

A clustering-based competitive particle swarm optimization with grid ranking for multi-objective optimization problems.

The goal of the multi-objective optimization algorithm is to quickly and accurately find a set of trade-off solutions. This paper develops a clustering-based competitive multi-objective particle swarm optimizer using the enhanced grid for solving multi-objective optimization problems, named EGC-CMOPSO. The enhanced grid mechanism involved in EGC-CMOPSO is designed to locate superior Pareto optimal solutions. Subsequently, a hierarchical-based clustering is established on the grid for improving the accuracy rate of the grid selection. Due to the adaptive division of clustering centers, EGC-CMOPSO is applicable for solving MOPs with various Pareto front (PF) shapes. Particularly, the inferior solutions are discarded and the leading particles are identified by the comprehensive ranking of particles in each cluster. Finally, the selected leading particles compete against each other, and the winner guides the update of the current particle. The proposed EGC-CMOPSO and the eight latest multi-objective optimization algorithms are performed on 21 test problems. The experimental results validate that the proposed EGC-CMOPSO is capable of handling multi-objective optimization problems (MOPs) and obtaining superior performance on both convergence and diversity.

Unraveling the rate-limiting step in microorganisms' mediation of denitrification and phosphorus absorption/transport processes in a highly regulated river-lake system.

River-lake ecosystems are indispensable hubs for water transfers and flow regulation engineering, which have frequent and complex artificial hydrological regulation processes, and the water quality is often unstable. Microorganisms usually affect these systems by driving the nutrient cycling process. Thus, understanding the key biochemical rate-limiting steps under highly regulated conditions was critical for the water quality stability of river-lake ecosystems. This study investigated how the key microorganisms and genes involving nitrogen and phosphorus cycling contributed to the stability of water by combining 16S rRNA and metagenomic sequencing using the Dongping river-lake system as the case study. The results showed that nitrogen and phosphorus concentrations were significantly lower in lake zones than in river inflow and outflow zones (p < 0.05). Pseudomonas, Acinetobacter, and Microbacterium were the key microorganisms associated with nitrate and phosphate removal. These microorganisms contributed to key genes that promote denitrification (nirB/narG/narH/nasA) and phosphorus absorption and transport (pstA/pstB/pstC/pstS). Partial least squares path modeling (PLS-PM) revealed that environmental factors (especially flow velocity and COD concentration) have a significant negative effect on the key microbial abundance (p < 0.001). Our study provides theoretical support for the effective management and protection of water transfer and the regulation function of the river-lake system.