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BackgroundGlucosamine 6-phosphate N-acetyltransferase (GNPNAT1) is a crucial enzyme involving hexosamine biosynthesis pathway and is upregulated in breast cancer (BRCA). However, its biological function and mechanism on patients in BRCA have not been investigated.MethodsIn this study, the differential expression of GNPNAT1 was analyzed between BRCA tissues and normal breast tissues using the Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database, which was validated by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry. Then, the potential clinical value of GNPNAT1 in BRCA was investigated based on TCGA database. Functional enrichment analyses, including Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Gene Set Variation Analysis, were performed to explore the potential signaling pathways and biological functions involved in GNPNAT1 in BRCA. Tumor immune infiltration was analyzed using ESTIMATE, CIBERSORT and TISIDB database; and immune therapy response scores were assessed using TIDE. Finally, Western blot, Cell counting kit-8 and Transwell assay were used to determine the proliferation and invasion abilities of breast cancer cells with GNPNAT1 knockdown.ResultsGNPNAT1 was up-regulated in BRCA tissues compared with normal tissues which was subsequently verified in different cell lines and clinical tissue samples. Based on TCGA and GEO, the overexpression of GNPNAT1 in BRCA contributed to a significant decline in overall survive and disease specific survive. Functional enrichment analyses indicated that the enriched pathways in high GNPNAT1 expression group included citrate cycle, N-glycan biosynthesis, DNA repair, and basal transcription factors. Moreover, the overexpression of GNPNAT1 was negatively correlated with immunotherapy response and the levels of immune cell infiltration of CD8+ T cells, B cells, natural killer cells, dendritic cells and macrophages. Knockdown of GNPNAT1 impairs the proliferation and invasion abilities of breast cancer cells.ConclusionGNPNAT1 is a potential diagnostic, prognostic biomarker and novel target for intervention in BRCA.

Discrimination of semantic textual similarity refers to comparing the similarity between two or more entities (including words, short texts and documents) through certain strategies to obtain a specific quantitative similarity value. Traditional research put more experience into the similarity calculation of the original text content, using the matching degree or distance of characters or words as the yardstick to judge whether the text pairs are similar. However, there are still some problems to be solved in the following aspects: the key points of sentence meaning and word semantics, which play important role in the semantic expression of natural language, are not well integrated into the similarity discrimination, and the interactive features between texts are not fully utilized. To solve the above problems, this paper proposes a novel discrimination structure based on the Siamese Network model and the idea of text matching. In this structure, we introduce sentence meaning key information and word semantic information to realize the extraction of word interaction feature information, and then we realize the text vector representation by using Siamese BiLSTM. The experimental results showed that the accuracy of the proposed model is higher than that of the basic models. &nbsp

Dialogue systems have received increasing attention while automatically evaluating their performance remains challenging. User satisfaction estimation (USE) has been proposed as an alternative. It assumes that the performance of a dialogue system can be measured by user satisfaction and uses an estimator to simulate users. The effectiveness of USE depends heavily on the estimator. Existing estimators independently predict user satisfaction at each turn and ignore satisfaction dynamics across turns within a dialogue. In order to fully simulate users, it is crucial to take satisfaction dynamics into account. To fill this gap, we propose a new estimator ASAP (sAtisfaction eStimation via HAwkes Process) that treats user satisfaction across turns as an event sequence and employs a Hawkes process to effectively model the dynamics in this sequence. Experimental results on four benchmark dialogue datasets demonstrate that ASAP can substantially outperform state-of-the-art baseline estimators., Comment: To appear at ACL 2023

The task of empowering large language models (LLMs) to accurately express their confidence, referred to as confidence elicitation, is essential in ensuring reliable and trustworthy decision-making processes. Previous methods, which primarily rely on model logits, have become less suitable for LLMs and even infeasible with the rise of closed-source LLMs (e.g., commercialized LLM APIs). This leads to a growing need to explore the untapped area of \emph{non-logit-based} approaches to estimate the uncertainty of LLMs. Hence, in this study, we investigate approaches for confidence elicitation that do not require model fine-tuning or access to proprietary information. We introduce three categories of methods: verbalize-based, consistency-based, and their hybrid methods for benchmarking, and evaluate their performance across five types of datasets and four widely-used LLMs. Our analysis of these methods uncovers several key insights: 1) LLMs often exhibit a high degree of overconfidence when verbalizing their confidence; 2) Prompting strategies such as CoT, Top-K and Multi-step confidences improve calibration of verbalized confidence; 3) Consistency-based methods outperform the verbalized confidences in most cases, with particularly notable improvements on the arithmetic reasoning task; 4) Hybrid methods consistently deliver the best performance over their baselines, thereby emerging as a promising state-of-the-art approach; 5) Despite these advancements, all investigated methods continue to struggle with challenging tasks, such as those requiring professional knowledge, leaving significant scope for improvement of confidence elicitation., Comment: 11 Pages

Selective catalytic reduction (SCR) systems are important technical means of mitigating NOx emissions for diesel engines. The major challenge of this technique is to improve the low-temperature act...

Until now, only the complete mitochondrial genome (mtDNA) of Pelecanus occidentalis and Pelecanus crispus have been sequenced. In order to explore the characteristics of mtDNA of the two Pelecanidae species and analyze their phylogenetic relationship, the two mtDNA were compared with Ciconia ciconia as reference. The mtDNA of the P. occidentalis and P. crispus were determined with the size of 17, 286 bp and 16, 131 bp, respectively. Both sequences contain 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. Gene of P. occidentalis and P. crispus are in the same arrangement and show positive AT skew and negative GC skew. There are some differences in intervals and overlap regions between the two species. The phylogenetic analysis show that the P. occidentalis and P. crispus grouped one branch and the relationship of Pelecanidae birds, Ciconiiformes birds and Spheniscifomes birds is relative. The study provid more genetic information for P. occidentalis and P. crispus, which is beneficial to the protection of them.

Invasive alien plants not only decrease riparian vegetation diversity but also alter wetland ecosystem carbon processes, especially when they displace the original vegetation. Invasive Canada goldenrod (Solidago canadensis L.) has colonized large areas of disturbed and undisturbed land in southeastern China, yet little is known regarding how it affects soil carbon cycling. To explore the response patterns of soil respiration following S. canadensis invasion and their driving mechanisms, an observational field study and a greenhouse experiment simulating invasion were performed. In the field study, soil respiration was measured weekly from 21th July 2018 to 15th December 2018. In the greenhouse experiment, soil, autotrophic and heterotrophic respiration were measured every 1st and 15th of the month from 15th July 2019 to 15th December 2019. Soil, autotrophic and heterotrophic respiration were measured using a closed-chamber system with the deep gauze collar root exclusion method. Solidago canadensis invasion appeared to decrease the total soil CO2 emissions in both the field study and the greenhouse experiment. The suppressive effects on soil respiration may be attributed to S. canadensis invasion-induced alterations in the quality and quantity of available soil substrate, suggesting that S. canadensis invasion may impact soil carbon cycling via plant-released substrates and by competing for the soil available substrate with native plant and/or soil microbes. These results have substantial implications for estimations of the effects of invasive plants on belowground carbon dynamics and their contribution to the warming world.

Non-road machinery is very important, but non-road machinery has problems such as working under complex operating conditions. Agricultural machinery is an important type of non-road machinery, whic...

An insufficient amount of NH3 (ammonia) will reduce the conversion efficiency of NOx, which may lead to excess NOx emissions, resulting in NH3-SCR failure. In this article, SCR failure caused by a low NH3- NOx ratio is studied systematically by experiments. The main reasons for a low NH3-NOx ratio in SCR include insufficient urea injection, hydrothermal aging of catalysts and urea crystallization. It was found from an insufficient urea injection experiment that with the increase of NH3- NOx ratio, the NOx conversion efficiency of the SCR system increased, but the ammonia leakage also increased. The main influencing factors of NOx conversion efficiency are different under different NH3- NOx ratios. A flow reactor system was used in the catalyst hydrothermal aging experiment to investigate the effect of hydrothermal aging on catalyst activity. After a 24 h hydrothermal aging experiment at 800 °C, the NOx conversion efficiency of the copper-based zeolite catalysts decreased significantly at the boundary of medium and low temperature regions. And the NO2- NOx ratio in the mixture had a significant effect on the catalytic performance. Thermogravimetry coupled to Fourier transform infrared spectroscopy (TG-FTIR) was used to analyze the composition of urea deposits in a urea deposits analysis experiment. It was found that the main components of urea deposits were urea and isocyanic acid (HNCO). Preventing HNCO polymerization, especially the formation of CYA, can decrease the formation of urea deposits.

Rotors with active flap control have considerable potential in reducing vibration and noise and improving aerodynamic performance. However, due to the movement of the flap, there are unavoidable gaps between the components that will lead to significant changes in the aerodynamic characteristics. Moreover, considering the difficulties in motion modeling and the accuracy of the simulation of the flow field in such a narrow gap, carrying out related research is challenging; thus, there has been inadequate targeted research, and that which does exist requires supplementation. To carry out this challenging flow field simulation, the overset assembly algorithm proposed by the author in previous research is adopted in the present study. It is used to successfully assemble the narrow gap, and the accuracy of the simulation is fully verified by comparing the results with the actual experimental results and a grid study. Furthermore, to compensate for the lack of research and experiments on the gap effect, cases considering a complete range of gap widths from an absence of a gap to a width of 10% of the chord length are set up and carried out under the following three case groups: steady cases with a fixed trailing-edge deflection angle, unsteady cases in which only the trailing-edge flap is flapping, and full-motion cases characterized by the periodic flap of the main airfoil and the trailing-edge flap. The results show that the gap increases the drag of the trailing-edge flap and decreases aerodynamic efficiency, especially at low speeds and high angles of attack. Nevertheless, when the gap is unavoidable, there is a range of the gap width that makes unapparent the decrease of aerodynamic efficiency. Moreover, the decrease of aerodynamic efficiency can be reduced as much as possible by a well-designed gap region geometry to ensure that the airfoil and the trailing-edge flap fit together when moving.

Used cooking oil (UCO) biodiesel may be one of the most potential alternative fuels in China to lower the dependency on crude oil for transportation. An experimental study has been conducted to assess the interactions between biodiesel produced from UCO in Shanghai and elastomer materials on high-speed marine diesel engines by immersing elastomer materials into conventional fossil diesel, 5, 10, and 20%, of a volumetric blending ratio of UCO biodiesel and pure UCO biodiesel. The test duration is 168 h at different temperatures of 25, 50, and 70 °C. Meanwhile, the effects of the mixing ratio of UCO biodiesel and the immersion temperature on the compatibility of elastomer materials with UCO biodiesel were analyzed. The results revealed that elastomer materials such as nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), fluororubber (FKM), and silicone rubber (SR) exposed to biodiesel blends would reveal worse but acceptable changes than those exposed to petroleum diesel, including the slight increase of mass and volume and decline of tensile strength and hardness. FKM, NBR, and SR represented better compatibility with pure UCO biodiesel than diesel, and EPDM showed worse compatibility with UCO biodiesel as the blend ratio rises. In general, the recommended volumetric mixing ratio of UCO biodiesel should be no larger than 20%. The present study could be helpful for the investigation of UCO biodiesel blends as a potential fuel to satisfy the energy demand.

Selective catalytic reduction (SCR) is one of the main methods used to reduce NOx emissions from diesel engines. Vanadium-based catalysts are widely used in SCR because of their good sulfur resistances and low costs. In this paper, for improving the catalytic performance of aged SCR, experimental and simulation methods were used to study the effects of the aged SCR state, space velocity, and ammonia-to-nitrogen ratio on the NOx conversion efficiency. The experimental results showed that the catalytic performances of the aged SCR state in the low- and medium-temperature regions were not significantly different from that of the fresh SCR, and the degradation in the high-temperature region was significant. In the low- and high-temperature regions, space velocity was an important factor affecting the aged SCR. Increasing the ammonia-to-nitrogen ratio could compensate for the effect of the SCR aging in the low- and medium-temperature regions to some extent.

Supplemental material, sj-docx-1-pid-10.1177_09544070221121868 for Effect of idle-start-go on the economy and emissions of gasoline vehicles by Zhiyuan Hu, Zhuo Wang, Zhangying Lu, Jiaming Fu and Yifeng Quan in Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering

Blade-vortex interaction (BVI) noise is a significant source of rotor noise. In recent years, active flap control (AFC) has been used successfully to control BVI by adding a trailing edge f...

A unified power quality controller based on a magnetic flux control tunable reactor is proposed. The magnetic flux control tunable reactor is composed of a voltage source inverter (VSI) and a transformer with an air gap. The power quality controller is divided into two parts: the harmonic open circuit part is connected in series in the system, and the harmonic short circuit part is connected in parallel in the system. Among them, the series part detects the fundamental wave component of the primary side current of the transformer, generates a reference signal, and controls the VSI to generate a fundamental wave controllable current, after the filter is applied to the secondary side of the transformer, the primary side of the transformer will show variable impedance and open circuit to the fundamental wave and harmonic current respectively; The parallel part detects the fundamental wave component of the primary side current, generates a reference signal, and controls the VSI to generate a fundamental controllable voltage, After the filter is applied to the secondary side of the transformer, the primary side of the transformer presents controllable impedance and short circuit to the fundamental wave and harmonic current respectively.By building a MATLAB simulation model, the effectiveness of the proposed unified power quality controller is verified.

With the emergence of digital grid concept, the current metering system using PTP (Precise Time Protocol) clock synchronization technology cannot provide a unified device clock system across entire network, which affects two-way real-time control of new energy. And it is difficult to meet the clock for new business transactions synchronization accuracy requirements. Under the original metering clock system, a multi-source clock weighted fusion technology was proposed that used 5G communication modules as reference clocks, and used Kalman filtering to complete step-by-step clock correction at all levels of network nodes to achieve coordinated correction of different external reference clocks. The highest clock synchronization accuracy ensure the consistency of real-time data collection clock. Based on field test data collected by the Shenzhen Power Supply Bureau, the results showed that the electricity bill settlement after clock synchronization optimization processing is closer to field settlement.

A comparative experiment was conducted based on a non-road diesel engine to investigate the effects of two after-treatment devices on the engine's emission characteristics as well as their power and fuel consumption performances. The first after-treatment device is a combination of a diesel oxidation catalyst (DOC) and a catalytic diesel particulate filter (CDPF). The second device is a single CDPF-coated improved noble metal catalyst. Results showed that the two after-treatment devices had almost no effect on the power and fuel consumption performance. The gaseous and particulate emissions of the engine depended on the operation conditions including the speed and load. However, the dual DOC+CDPF system and the single CDPF reduced more than 81% of the carbon monoxide (CO) and 73% of the hydrocarbon (HC) emissions. Notably, the reduction efficiency by the single CDPF was higher than that of the DOC+CDPF system. In terms of the particulate emissions, both after-treatment devices achieved more than 96% reduction of the particle number (PN) and up to 88% reduction of the particulate mass (PM). Similarly, the single CDPF outperformed the dual DOC+CDPF system in reducing particle emissions. Although no changes occurred in the bimodal particle size distribution of the engine after the installation of the two after-treatment devices, they performed differently in reducing particles with different sizes. The particles reduction efficiency of the DOC+CDPF system was higher than that of the single CDPF for the particles smaller than 14.3 nm, and this trend converted for particles larger than 14.3 nm. Improving the noble metal catalyst load in the CDPF ensured a performance that rivaled the DOC+CDPF system. Apart from the NOx emissions, the installation of a single CDPF with an improved noble metal catalyst load can make the non-road diesel engine meet the limits of the China IV emission regulations.

The durability of V2O5-WO3/TiO2 selective catalytic reduction (SCR) catalysts for heavy-duty diesel engines was evaluated based on 500 h SCR durability tests conducted using B20 fuel (20% v/v biodiesel + 80% v/v petroleum diesel). The fresh and deteriorated SCR catalysts were characterized by X-ray fluorescence, X-ray diffraction, and Brunauer-Emmett-Teller surface area measurements to investigate the deterioration mechanism of the catalysts. The results show that the SCR de-NOx performance is degraded after SCR durability testing, particularly at high engine speeds. The NOx conversion efficiency of the deteriorated SCR catalysts decreases at temperatures above 400 °C but remains high at temperatures between 250 and 400 °C. The catalyst characterization results reveal that the deterioration in the de-NOx performance is not owing to anatase-to-rutile transformation of TiO2, but because of a decrease in the specific surface area and the loss of the catalyst components, which are greater in the front cross section of the SCR than in the rear cross section. For a given catalyst cross section, the decrease in the specific surface area exhibits a positive correlation with the flow rate of the exhaust gas.

Particle number is a key index for evaluating particulate emissions, and diesel oxidation catalysts (DOCs) are one of the most important technologies for controlling the particulate emissions of a diesel engine. In this paper, a novel phenomenological one-dimensional model was established to predict particle number and size distributions at a DOC outlet with the aim of investigating the effects of DOC on particle number emissions. The phenomenological model consisted of two submodels: submodel-1, a global kinetic model for calculating particle size in particle number and size distributions after particles had passed through the DOC, and submodel-2, an original global parametric model for calculating the particle number at the DOC outlet. The effects of the sampling process, fuel properties, and the engine operating condition were considered in submodel-2. An 8.8 L, direct-injection, heavy-duty diesel engine was tested. The particle number and size distributions at the DOC inlet and outlet were determined using an engine exhaust particle sizer. The test data, coupled with literature results, were used to calibrate and validate the phenomenological model. This model was then applied to investigate the influence of various factors on particle number and size distributions at the DOC outlet. It was found that dilution temperature, fuel sulfur content, exhaust gas temperature, and gas hourly space velocity (GHSV) played a key role in the particle number after DOC oxidation. The particle number concentration at the DOC outlet increased as fuel sulfur content and exhaust gas temperature increased and decreased as GHSV and dilution temperature increased. In general, results proved that this phenomenological model was accurate enough to predict particle number and size distributions at a DOC outlet under most operating conditions. It may serve as a useful tool for research and development focusing on PM reduction of diesel engines and air pollution control.

The primary purpose of this study is to evaluate effects of waste-cooking-oil biodiesel on the particle number (PN), size distribution and particulate-phase compositions including organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs), N-alkanes, fatty acids and inorganic ions from a diesel bus. Experiments were conducted based on chassis dynamometer with three biodiesel blends at 5%, 10% and 20% by volume, i.e., B5, B10 and B20; and a petroleum diesel D100 was used as a baseline. Results showed that the biodiesel resulted in a reduction in the PN emission, and this reduction increased linearly with the biodiesel ratio. For B20, the reduction in PN emission reached 42.2% in comparison with D100. The particle size distribution indicated that the utilization of the biodiesel increased the proportion of nucleation mode particles, and correspondingly diminished the proportion of accumulation mode particles. Compared with D100, 14.8%, 21.2% and 27.6% reduction in the OC emission was observed for B5, B10 and B20, whereas the EC emission increased slightly, consequently, the ratio OC/EC presented a declining trend. The PAHs, dominated by 3- and 4- rings ones, as well as their toxic equivalent were also reduced with the biodiesel. Additionally, using biodiesel led to lower N-alkanes and fatty acids emissions in the particles, and the reduction of emissions showed a decreased and increased trend with the biodiesel ratio, respectively. In terms of the inorganic ions in the particles, the Cl−, NO2−, NO3−, SO42−, as well as the Na+, NH4+, K+ and Ca2+ emissions were increased with the biodiesel. To sum up, the refining of biodiesel from waste cooking oil is a cleaner production, and as an alternative fuel to petroleum diesel, the biodiesel is also environment-friendly.

Herein, through the active-peptide-functionalization, we developed a nanoscale micelles system (named HEKM) which consists of tumor microenvironment-regulated shape-changing with specific recognition abilities for enhanced cellular targeting, internalization and therapy of heterogeneic tumors. As a result, HEKMs could recognize and bind the tumor heterogeneity marker EGFR-HER2 complex, which led to an enhanced tumor targeting effect. In particular, HEKMs could self-assemble into nanorods under normal physiological conditions while transform into nanospheres in the tumor extracellular microenvironment by a sensitive response to matrix metalloproteinase-2 (MMP-2). The nanorods could prolong the blood circulation time while the nanospheres could accelerate tissue penetration in tumors. In vivo dual-modal targeted imaging was realized by FRET-fluorophore conjugation and gadolinium loading in HEKMs. Tumor cell apoptosis was achieved by proapoptotic element integration. The in vitro and in vivo studies both demonstrated that these rationally designed, shape-changing and targeting micelles could achieve maximized drug efficacy and minimum side effects.

Additional file 2. Review history.

Additional file 1: Fig. S1-S7 and Table S1.

This study aims to investigate the effect of durability on the regulated and unregulated emissions, as well as the power and fuel economy performance of a biodiesel-powered engine equipped with a diesel oxidation catalyst (DOC) and a selective catalytic reduction (SCR) system based on a 500-h durability test. Furthermore, a BET (Brunauer-Emmett-Teller) test was employed to analyze the specific surface area changes of the DOC and SCR. Results show that after the durability, the power performance improved and the brake-specific fuel consumption (BSFC) reduced due to the running-in effect. Although the deterioration of the DOC and SCR after the durability resulted in an increase in the carbon monoxide (CO), total hydrocarbon (THC) and nitrogen oxide (NOX) emission factors of the biodiesel-powered engine based on European steady state cycle (ESC) by 41.3%, 36.1% and 39.2%, respectively, these emissions were still below China-Ⅴ limits. For unregulated emissions, the reduced BSFC caused by the durability led to a decrease in the carbon dioxide (CO2) and sulfur dioxide (SO2) emissions, but the durability resulted in higher aldehyde emission. The BET specific surface areas of the DOC and SCR decreased by 40.2% and 35.0%, respectively after the durability, which accounted for their catalytic performance deterioration.

Particulate emissions from an urban bus fueled with B20 (20% biodiesel from waste cooking oil and 80% diesel by volume) were investigated using portable emissions measurement system (PEMS), then the effect of a catalyzed continuously regeneration trap (CCRT) on the particulate emissions of the B20-fueled bus were ascertained. Results show that compared with a D100 (pure diesel), B20 reduced particulate number (PN) and particulate mass (PM) emission rates of the bus by 13.9% and 24.3% under cruise control. Under transient condition, B20 reduced the PN and PM emission rates by 18.4% and 16.3%. B20 decreased the total PN concentration by 6.6% whereas increased the proportion of nucleation particles from 89.0% to 92.0%. Correspondingly causing a decrease in the GMD (geometric mean diameter) from 43.02 nm to 41.25 nm under cruise condition, and from 41.26 nm to 39.57 nm under transient condition. Using a CCRT exhibited an excellent filtration effect on both PN and PM from the B20-fueled bus. Both under cruise and transient conditions, CCRT could reduce more than 93% of the PN and PM. In addition, CCRT had a better filtration effect on accumulation particles. The use of CCRT also changed the particle size bimodal distribution of the B20 by removing the accumulation mode peak.

Altitude has a significant effect on the combustion of diesel engines during cold start, especially during speed-up. In this study, combustion characteristics of speed-up period were investigated using an experimental test on a heavy-duty diesel engine with an intake and exhaust pressure controlled by the plateau simulation test system to simulate altitude conditions including 0 m, 3000 m and 4500 m. Further effects of altitude on ignition characteristics of diesel engine were accomplished through a zero-dimensional thermodynamic model coupled with a detailed kinetic model. Results indicated that as the altitude rose from 0 m to 3000 m, the pressure in the cylinder was reduced, the number of diesel engine speed-up cycles increased, and the rising speed ratio decreased during speed-up. There was a misfire after the fifth cycle at an altitude of 4500 m, and the rising speed ratio was significantly reduced. Through analysis of fuel injection, air intake and ignition phase, we confirmed that the misfire at the high 4500 m altitude was caused by the ignition delay, which was mainly controlled by chemical reaction during cold start. In the detailed kinetic study, the hot-flame and blue-flame reactions slowed down in the chemical reaction of the mixture as the altitude rose. The higher altitude enhanced the H-atom abstraction, but weakened the second O2 addition and the peroxyalkylhydroperoxide isomerization. The decomposition reaction was enhanced. As a result, the overall reaction rate and the heat release fraction deteriorated, extending significantly the negative temperature coefficient (NTC) duration of the ignition.

The increasingly stringent emission regulations will mandate the retrofit of after-treatment devices for in-use diesel vehicles, in order to reduce their substantial particulate matter and nitrogen oxides (NOX) emissions. In this paper, a combination of DOC (diesel oxidation catalyst), CDPF (catalytic diesel particulate filter) and SCR (selective catalytic reduction) retrofit for a heavy-duty diesel engine was employed to perform experiment on the engine test bench to evaluate the effects on the particulate matter emissions including particle number (PN), particle mass (PM), particle size distributions and nitrogenous compounds emissions including NOX, nitrogen dioxide (NO2)/NOX, nitrous oxide (N2O) and ammonia (NH3) slip. In addition, the urea injection was also of our concern. The results showed that the DOC+CDPF+SCR retrofit almost had no adverse effect on the engine power and fuel consumption. Under the test loads, the upstream DOC and CDPF reduced the PN and PM by an average of 91.6% and 90.9%, respectively. While the downstream SCR brought about an average decrease of 85% NOX. Both PM and NOX emission factors based on this retrofit were lower than China-Ⅳ limits (ESC), and even lower than China-Ⅴ limits (ESC) at medium and high loads. The DOC and CDPF changed the particle size distributions, leading to the increase in the proportion of accumulation mode particles and the decrease in the percentage of nuclear mode particles. This indicates that the effect of DOC and CDPF on nuclear mode particles was better than that of accumulation mode ones. The upstream DOC could increase the NO2/NOX ratio to 40%, higher NO2/NOX ratio improved the efficiency of CDPF and SCR. Besides, the N2O emission increased by an average of 2.58 times after the retrofit and NH3 slip occurred with the average of 26.7 ppm. The rate of urea injection was roughly equal to 8% of the fuel consumption rate. The DOC+CDPF+SCR retrofit was proved a feasible and effective measurement in terms of reducing particulate emissions and NOX simultaneously for in-use engine. However, it also resulted in higher N2O emission, NH3 slip as well as urea injecting strategy problem which should be of further concern.

The real-world gaseous and particulate emission characteristics of an agricultural tractor retrofitted with a catalysed diesel particulate filter (CDPF) with different catalyst loadings were investigated. The tests were carried out using a portable emission measurement system (PEMS) under idling, running and working conditions. The results showed that the emissions of the tractor strongly depended on the operating conditions. From idling to running then to working condition, the emission rates increased but emission factors based on fuel consumption decreased, and the proportion of nucleation particles and geometric mean diameter presented a slight downward trend. The reduction effect of CDPF on the CO and total hydrocarbon (THC) improved from idling to running then to working condition, and it was enhanced by increasing catalyst loading. The particle number (PN) and particle mass (PM) reduction performance of CDPF was less affected by operating condition but enhanced with the increase of the catalyst loading. After the tractor was equipped with the CDPF, the particle size distribution maintained a bimodal shape, but the decrease of nucleation particles was significantly higher than that of accumulation particles, causing a decrease in the nucleation particles proportion and a shift of the peak towards smaller particle size. With the increase of the CDPF catalyst loading, the proportion of the accumulation particles increased, and the geometric mean particle size also increased. The findings of this paper can provide scientific references to design and optimize CDPF for non-road mobile machinery to achieve clean emissions.

Anthropogenic nitrogen (N) inputs lead to the increase of phosphorus (P) demand for plants and plant species competition in a N enriched environment may hinge on its ability to utilize soil P sources. In soils, P mostly exists as insoluble phosphate compounds with three mineral elements: iron (Fe), aluminum (Al) or calcium (Ca), and it remains largely unknown whether invasive plant species are able to access such insoluble P sources and its interaction with N enrichment to gain competitive advantage. We determined the morphological traits, growth and nutrient status of an invasive plant Canada goldenrod (Solidago canadensis L.) cultured in soluble phosphate KH2PO4 (Ortho-P), and insoluble inorganic phosphate AlPO4 (Al–P), FePO4 (Fe–P), Ca5(OH)(PO4)3 (Ca–P) at three N supply levels. Results showed that S. canadensis was able to selectively utilize P from Al–P but not from Fe–P or Ca–P by increasing root number and length under N additions. The increasing growth in S. canadensis was closely correlated with the increasing foliar P. Ability to utilize insoluble P sources under enriched N environment serves as a competitive advantage for S. canadensis in Al rich soils. Effective control of S. canadensis invasion may need to consider soil P management in the context of atmospheric N deposition as well.

Exhaust particle emissions from a heavy duty diesel engine using B20 biodiesel (20% biodiesel blend with 80% diesel by volume) were investigated, and the engine was equipped with three kinds of exhaust aftertreatment devices: DOC (diesel oxidation catalyst), DOC + DPF (diesel particle filter), and DOC + CDPF (catalyzed diesel particle filter). Particle mass, particle number and size distribution, and PAHs (polycyclic aromatic hydrocarbons) and inorganic ions in the particle emissions from the engine were studied. Compared with the engine without exhaust aftertreatments, DOC decreased nucleation mode particle number by 19.83%, while accumulation mode particles exhibited slight changes. The DOC + DPF reduced the total particle number by 82.54%, while the DOC + CDPF reduced it by 91.71%. Compared with the engine without exhaust aftertreatments, the three aftertreatments were shown to reduce total PAH emissions. DOC + DPF and DOC + CDPF can decrease total TEQ (toxicity equivalent quantity) effectively with a sharp decrease in PAH mass. The DOC increased the TEQ of particles by 46.9%. The catalyst in the DOC increased some high molecular weight PAHs such as BaA, BbF + BkF, and BaP, which led to the increase in TEQ. The DOC increased the total inorganic ions by 2%, while the DOC + DPF and DOC + CDPF decreased inorganic ions by 89.5% and 82.9%, respectively. Catalysts in DOC and CDPF promotes the formation of SO 4 2− and NO 3 − , which leads to higher inorganic ion emissions with DOC than no aftertreatments and higher inorganic ion emissions with a DOC + CDPF than with a DOC + DPF.

Clonal integration facilitates the growth and reproduction of clonal plants by providing the ability to share resources among ramets in heterogeneous environments. The benefits of clonal integration for plant growth may depend on a contrast in resource availability and may encounter costs, especially when a young part of the clone is growing across a border between richer and poorer conditions than the old part. We studied a clonal amphibian plant growing across a border between an aquatic and a terrestrial ecosystem, which typically differ in the availability of resources. We asked whether the young part of the clone is supporting the old part with phosphorus and whether this support has costs. We performed an experiment with Alternanthera philoxeroides where plants grow from water to a terrestrial habitat. The terrestrial habitat had either a low or high phosphorus supply, and the connection between the old and young parts of the clone was either left intact or split. We determined that the young part of the clone growing in a terrestrial habitat supported the old part with phosphorus when growing on a substrate rich in phosphorus. We have found no cost of this resource translocation; on the contrary, whole clones increased not only their accumulation of phosphorus, but also of nitrogen. Our study shows how an amphibian plant may profit from heterogeneous habitats by resource sharing in a clonal network.

Modern Gasoline Direct Injection (GDI) vehicles offered higher power output, improved fuel economy and reduced CO2 emissions compared with port fuel injection (PFI) vehicles. However, the particle number emission of GDI is larger than that of PFI and also higher than diesel vehicles equipped with diesel particle filter (DPF). This research sampled particle matter (PM) emitted from a China VI vehicle over the Worldwide harmonized Light vehicles Test Cycle (WLTC). The results of particle size distribution showed that ultra-fine particles in diameter below 23 nm take up majority of particle emissions. While with the oxidation temperature rising, the peak diameter of emitted particles migrated to larger section. The effect of oxidation temperature including interlayer spacing, fractal dimension, fringe length and tortuosity have been analyzed by TEM. The value of nano structural parameters increases slightly with the temperature increasing. Besides, the impact of volatile components was considered into the micromorphology and microstructure parameters of primary particles. After eliminating volatile materials, there is no presence of hollow carbon particles and all the three parameters including interlayer spacing, fringe length and fringe tortuosity showed an overall decrease. Better understanding nano structural parameters of PM under different oxidation temperatures can provide information to explain the potential impacts of particle emissions on human health and environment and the regeneration process of gasoline particle filter (GPF).

In recent years, horticultural plants have frequently suffered significant heat damage due to excessive temperatures. In this study, a horticultural spray cooling system was designed, consisting mainly of a jet fan and spraying system. CFD simulation technology and response surface methodology were used to optimize the design of the jet fan, which improved the thrust of the fan. The length of the inlet section was 300 mm, the length of the outlet section was 300 mm, the length of the cone section was 450 mm, and the diameter of the outlet was 950 mm, where the thrust of the jet fan was 225.06 N. By establishing the CFD model of spray cooling in a tea field and designing a L9 (34) orthogonal experiment, the effect of the spray parameters on the maximum temperature drop and effective cooling distance was studied, and the best parameters were selected. The simulation results show that the optimum parameters are a spray flow rate of 4.5 kg/s, a droplet diameter of 15–45 μm, a droplet temperature of 298.15 K, and a nozzle double circle layout. Based on the simulation results of the optimized jet fan and spray parameters selected, a spray cooling test bench was established. Field test results show that when the initial ambient temperature was 310.05 K–310.95 K, the maximum temperature drop of the spray cooling fan was 9.1 K, and the cooling distance was approximately 36.0 m. The temperature drop decreased with increasing distance from the fan. This study is of great significance to protect horticultural plants from extremely high temperatures.

Nitrogen oxides (NOx) and particle emissions from a light-duty diesel car with B10 (10% biodiesel from cooking oil +90% diesel, v/v) and G10 (10% GTL fuel +90% diesel, v/v) were investigated under the New European Driving Cycle (NEDC). The car was equipped with a high-pressure common rail system, cooled exhaust gas recirculation (EGR), and diesel oxidation catalyst (DOC). Results show that G10 has the lowest fuel consumption and B10 has the highest fuel consumption among the three fuels. B10 can increase the NOx emissions, and the G10 NOx emission is lower than diesel. The number-weighted particle size distribution shows that B10 and G10 can decrease the particle number at almost a full size range. In the four urban driving cycles (UDC), the geometric mean diameter (GMD) of B10 and G10 are both smaller than diesel. For the extra urban driving cycle (EUDC), the particle number concentration and emission rate are far higher than UDC cycle. The acceleration phase has a higher particle number emission rate and nucleation particle number than deceleration for the three fuels. Particle number emission is reduced when using B10 and G10 regardless of acceleration or deceleration. Number-weighted particle size distribution in acceleration and deceleration shows that the nucleation particle number in deceleration is far higher than acceleration, whereas accumulation particle shows the opposite tendency.

Altitude has a significant effect on combustion of heavy-duty diesel engines, especially during cold start. An experimental study on a heavy-duty diesel engine operating at different altitudes was conducted. Tests were based on a direct injection (DI) turbocharged diesel engine with intake and exhaust pressure controlled by the plateau simulation test system to stimulate altitude conditions including 0 m, 1000 m, 2000 m, 3000 m and 4000 m. Results indicated that the compression and expansion resistance moment reduced and the speed increased during the cranking period. The peak pressure of several cycles was increased during the start-up period; however, the expansion pressure dropped more and the indicated mean effective pressure (IMEP) reduced as the altitude rose. While at an altitude of over 2000 m, the peak pressure fluctuated obviously during the start-up period. The higher the altitude was, the more the fluctuation amplitude and cycle number increased and combustion instability enhanced, which resulted the start-up period time increasing at high altitude. When the altitude rose, the cycle-to-cycle variation of the peak pressure and speed fluctuation increased during the idle, the ignition and CA50 were delayed and the combustion duration was shortened. The effect of altitude on combustion characteristics of the diesel engine was more significant during the start-up period than during its idle period.

One of the ways to meet future emission standards for cars and to limit the peak pressure of a heavy-duty, highly supercharged diesel engine is to reduce the compression ratio. Nevertheless, complications appear because stringent limitations to a reduction in the diesel compression ratio are the start-up requirements, in particular at high altitudes. An experimental study was conducted on the effect of the altitude on the combustion characteristics during the start-up process of a direct-injection midspeed intercooled turbocharged diesel engine with a compression ratio of 14.25:1. Specialized testing was conducted on the low-compression-ratio diesel engine, the intake pressure and the exhaust pressure of which were controlled by a plateau simulation test system to simulate the conditions at altitudes of 0 m, 1000 m, 2000 m, 3000 m, 3750 m and 4500 m. The results indicated that the pressure in the cylinder was lower during the cranking period as the altitude increased and that this caused the ignition operation to become difficult at altitudes above 3000 m. The combustion characteristics are significantly impacted by altitudes above 2000 m. At an altitude of 0–1000 m, the curve pattern of the cycle cylinder pressure had mainly a single peak during the start-up period. When the altitude increased to 2000 m, twin peaks and afterburn appeared in the cycles. Misfire appeared during the start-up period when the altitude increased to 3000 m, the combustion instability increased and the average indicated mean effective pressure decreased rapidly. When the altitude increases, the cycle-to-cycle variations in the peak pressure increased during idle, the ignition and the crank angle position at 50% of the cumulative heat release rate were delayed and the combustion duration was extended.

Plastin 3 (PLS3) overexpression may serve as a marker for predicting chemotherapeutic outcomes in drug-resistant cancer cells, but the mechanism is unclear. Herein, we show that the down-regulation of PLS3 by PLS3 gene silencing augments the sensitivity of MDA-MB-231 triple-negative breast cancer cells to paclitaxel. Interestingly, a low concentration of paclitaxel was able to induce strong apoptosis in the PLS3-silenced cells. Further study revealed that p38 MAPK signalling was responsible for the increased sensitivity to paclitaxel in these cells, as the p38 MAPK inhibitor SB203580 impaired the changes mediated by PLS3 down-regulation in response to paclitaxel. Therefore, our study identifies PLS3 as a potential target for enhancing the p38 MAPK-mediated apoptosis induced by paclitaxel. Unlike paclitaxel, Abraxane was unable to induce strong apoptosis in the PLS3-silenced cells. As PLS3 was found to be involved in the process of endocytosis in breast cancer cells, the reliance of cellular Abraxane uptake on this process may render it not as efficient as paclitaxel in PLS3-depleted tumour cells. The finding that PLS3 could be a critical regulator of paclitaxel sensitivity may have important implications for breast cancer chemotherapy.

The primary purpose of this study was to investigate the effect of a catalyzed continuously regenerating trap (CCRT) system composed of a diesel oxidation catalyst (DOC) and a catalyzed diesel particulate filter (CDPF) on the main gaseous and particulate emissions from an urban diesel bus, as well as the durability performance of the CCRT system. Experiments were conducted based on a heavy chassis dynamometer, and a laboratory activity test as well as X-ray photoelectron spectroscopy (XPS) test were applied to evaluate the changes of the aged CCRT catalyst. Results showed that the CCRT could reduce the CO by 71.5% and the total hydrocarbons (THC) by 88.9%, and meanwhile promote the oxidation of NO. However, the conversion rates for CO and THC dropped to 25.1% and 55.1%, respectively, after the CCRT was used for one year (~ 60,000 km), and the NO oxidation was also weakened. For particulate emissions, the CCRT could reduce 97.4% of the particle mass (PM) and almost 100% of the particle number (PN). The aging of the CCRT resulted in a reduced PM trapping efficiency but had no observable effect on the PN; however, it increased the proportion of nucleation mode particles. The activity test results indicated that the deterioration of the CCRT was directly relevant to the increase in the light-off temperatures of the catalyst for CO, C3H8 and NO2. In addition, the decreased concentrations of the active components Pt2+ and Pt4+ in the catalyst are also important factors in the CCRT deterioration.

Biodiesel is a promising alternative clean fuel for vehicles. In this paper, comprehensive particulate characteristics, including the particle number (PN), particle mass (PM), particle size distribution, particle micromorphology, chemical functional groups and particle oxidation activity from biodiesel blend B20 (20% biodiesel and 80% diesel by volume), were investigated based on a diesel bus using a heavy chassis dynamometer bench. Results showed that B20 could reduce the PN by 18.8% and the PM by 27.3%. The reduction efficiency of B20 on the accumulation mode particles was higher than that of the nucleation mode ones, which were 43.2 and 7.6%, respectively, thereby causing the proportion of the nucleation mode particles in B20 to increase from 54 to 66% in comparison with that of D100 (pure diesel). In terms of the particle micromorphology, the average fractal dimension of the particles from B20 was higher than that of D100, indicating that the particles from B20 were more compact. The proportion of typical core–shell structure particles in the basic carbon particles of B20 was higher than that of D100, and the coincidence degree between particles was also higher for B20; additionally, B20 preferred to produce basic carbon particles with a regular spherical shape. The graphitization degree of the particles increased with increasing oxidation temperature, but the lattice defect degree decreased. The Raman analysis reflected that the particles of B20 had a higher lattice defect degree but a lower graphitization degree compared with the particles of D100. The ratio of O/C, as well as the sp3/sp2 ratio of the B20 particles, were higher than those of the D100 particles, also indicating that more defects were present in the B20 particles. The particles from B20 exhibited higher oxidation activity in comparison with the particles from D100.

The rapid expansion of Canada goldenrod (Solidago canadensis L.) in China has drawn considerable attention as it may not only decrease vegetation diversity but also alter soil nutrient cycling in the affected ecosystems. Soil extracellular enzymes mediate nutrient cycling by catalyzing the organic matter decomposition, however, the mechanisms by which alien plant invasion may affect soil extracellular enzymes remain unclear. The objective of this study was to investigate the responses of soil extracellular enzyme activities and ecoenzymatic stoichiometry to S. canadensis invasion. Several extracellular enzymatic activities related to carbon, nitrogen, and phosphorus cycling were measured using a fluorometric method. Ecoenzymatic stoichiometry was used as a proxy of soil microbial metabolic limitations. S. canadensis invasion appeared to be associated with decreased activities of enzymes and with substantial conversions of microbial metabolic carbon and nitrogen limitations. The changes in the activities of extracellular enzymes and the limitations of microbial metabolism were correlated with the alterations in the nutrient availability and resource stoichiometry in the soil. These findings reveal that the alterations in soil available nutrients associated with S. canadensis invasion may regulate extracellular enzymatic activities and cause microbial metabolic limitations, suggesting that S. canadensis invasion considerably affects biogeochemical cycling processes.

This paper presents an investigation of emissions from gasoline direct injection (GDI) vehicles and analyzed the characteristics of emitted particulate matter (PM), the emission factors of particulate number (PN) and size distribution properties, including four test cycles: the new European driving cycle (NEDC), the worldwide harmonized light vehicle test cycle (WLTC), the USA federal test procedure-75 (FTP-75) and the China light-duty vehicle test cycle (CLTC). The results reveal that for China VI standard GDI vehicle, compared with CLTC, which is the newest test cycle according to realistic road conditions in China, the aforesaid evaluation indexes of FTP-75 and WLTC are basically higher due to their higher acceleration and deceleration ratio. Compared with hot start, a cold start followed by warming-up process has a significant impact on PN emissions over all test cycles and different test cycles show diverse sensitivity to the change of start-up conditions. The particles with a diameter of 5.6–23 nm (sub-23 nm) account for 43.1–57.7% of the total PN emission quantity for China V standard GDI vehicle, which is about 5–15% higher than that of theoretical assumptions. Different piecewise speed segments exhibited different impacts on PN characteristics when acceleration and deceleration reveal greater influence. Gasoline particulate filter (GPF) could effectively capture full-size particulates including fine particles as sub-23 nm particles, which is verified over FTP-75 and CLTC, while sub-23 nm PN emission is still at a high level over WLTC for its ultrahigh speed segment. There could have been an underestimation of the real particle number emitted from GDI vehicle while the emission of solid sub-23 nm particles was excluded under current emission regulations.