Phenotypic Variation Analysis and Excellent Clone Selection of Alnus cremastogyne from Different Provenances.

Alnus cremastogyne is a rapidly growing broad-leaved tree species that is widely distributed in southwest China. It has a significant economic and ecological value. However, with the expansion of the planting area, the influence of phenotypic variation and differentiation on Alnus cremastogyne has increased, resulting in a continuous decline in its genetic quality. Therefore, it is crucial to investigate the phenotypic variation of Alnus cremastogyne and select excellent breeding materials for genetic improvement. Herein, four growth-related phenotypic traits (diameter at breast height, the height of trees, volume, height under the branches) and twelve reproductive-related phenotypic traits (fresh weight of single cone, dry weight of single cone, seed weight per plant, thousand kernel weight, cone length, cone width, cone length × cone width, fruit shape index, seed rate, germination rate, germination potential, germination index) of 40 clones from four provenances were measured and analyzed. The phenotypic variation was comprehensively evaluated by correlation analysis, principal component analysis and cluster analysis, and excellent clones were selected as breeding materials. The results revealed that there were abundant phenotypic traits variations among and within provenances. Most of the phenotypic traits were highly significant differences (p < 0.01) among provenances. The phenotypic variation among provenances (26.36%) was greater than that of within provenances clones (24.80%). The average phenotypic differentiation coefficient was accounted for 52.61% among provenances, indicating that the phenotypic variation mainly came from among provenances. The coefficient of variation ranged from 9.41% (fruit shape index) to 97.19% (seed weight per plant), and the repeatability ranged from 0.36 (volume) to 0.77 (cone width). Correlation analysis revealed a significantly positive correlation among most phenotypic traits. In principal component analysis, the cumulative contribution rate of the first three principal components was 79.18%, representing the main information on the measured phenotypic traits. The cluster analysis revealed four groups for the 40 clones. Group I and group II exhibited better performance phenotypic traits as compared with group III and group IV. In addition, the four groups are not clearly clustered following the distance from the provenance. Employing the multi-trait comprehensive evaluation method, 12 excellent clones were selected, and the average genetic gain for each phenotypic trait ranged from 4.78% (diameter at breast height) to 32.05% (dry weight of single cone). These selected excellent clones can serve as candidate materials for the improvement and transformation of Alnus cremastogyne seed orchards. In addition, this study can also provide a theoretical foundation for the genetic improvement, breeding, and clone selection of Alnus cremastogyne.

[Size Distribution and Source Appointment of Road Particles During Winter in Tianjin].

The significant role of traffic emissions mixed from various sources in urban air pollution has been widely recognized. However, the corresponding contributions to the roadside particle distribution are poorly understood due to the mixed impacts of various sources. Particle number concentrations of different sizes at the roadside in Nankai District of Tianjin were continuously monitored using a portable aerosol particle spectrometer during the morning rush hour (07:30-09:20) from Nov. 9, 2018 to Jan. 6, 2019. Characteristic and influencing factors of particle size distributions were discussed combined with temperature and relative humidity data, while potential sources of particles at the roadside were identified based on size distribution analysis. The results showed that the average total particle number concentrations were 502 cm-3, and the concentrations of the accumulation mode and coarse mode were 500 cm-3 and 2 cm-3, respectively. The distribution of number concentrations at the roadside was unimodal and primarily concentrated at 0.25-0.50 µm, with peak sizes at 0.28-0.30 µm. The same distribution trend of particle number concentration and difference in the concentration in the same segment size were observed at different periods. Vehicle activity level was the main influencing factor of road particulate matter concentration on different weekdays; the probability of the high value of road particulate matter concentration was reduced by a reasonable combination of the vehicle tail numbers. Temperature and relative humidity were both found to be positively correlated with the number concentration of particles. With the increase in temperature and relative humidity, the total and peak particle number concentration showed an overall upward trend. In addition, the peak particle size increased from 0.28-0.30 µm to 0.35-0.40 µm when relative humidity was higher than 80%. Three sources, including road dust, brake and tire wear, and the aging particles from vehicle exhaust, were identified using positive matrix factorization in this study. Road dust contributed 8.6% of the total number concentration, which mainly consisted of particles with sizes above 5.00 µm. Brake and tire wear contributed 2.8% of the total number concentration of particles with a size range of 0.80-4.00 µm. The aging particles from vehicle exhaust contributed the most (88.5%), with a peak at 0.25-0.65 µm. The sources of roadside particles were mainly related to vehicle activity, whereas temperature and relative humidity also affected the particle number size distribution.

An Enhanced Positional Error Compensation Method for Rock Drilling Robots Based on LightGBM and RBFN.

Rock drilling robots are able to greatly reduce labor intensity and improve efficiency and quality in tunnel construction. However, due to the characteristics of the heavy load, large span, and multi-joints of the robot manipulator, the errors are diverse and non-linear, which pose challenges to the intelligent and high-precision control of the robot manipulator. In order to enhance the control accuracy, a hybrid positional error compensation method based on Radial Basis Function Network (RBFN) and Light Gradient Boosting Decision Tree (LightGBM) is proposed for the rock drilling robot. Firstly, the kinematics model of the robotic manipulator is established by applying MDH. Then a parallel difference algorithm is designed to modify the kinematics parameters to compensate for the geometric error. Afterward, non-geometric errors are analyzed and compensated by applying RBFN and lightGBM including features and kinematics model. Finally, the experiments of the error compensation by combing combining the geometric and non-geometric errors verify the performance of the proposed method.

Characteristics of PM2.5 in an Industrial City of Northern China: Mass Concentrations, Chemical Composition, Source Apportionment, and Health Risk Assessment.

Urban and suburban PM2.5 samples were collected simultaneously during selected periods representing each season in 2019 in Zibo, China. Samples were analysed for water-soluble inorganic ions, carbon components, and elements. A chemical mass balance model and health risk assessment model were used to investigate the source contributions to PM2.5 and the human health risks posed by various pollution sources via the inhalation pathway. Almost 50% of the PM2.5 samples exceeded the secondary standard of China's air quality concentration limit (75 µg/m3, 24 h). Water-soluble inorganic ions were the main component of PM2.5 in Zibo, accounting for 50 ± 8% and 56 ± 11% of PM2.5 at the urban and suburban sites, respectively. OC and OC/EC decreased significantly in the past few years due to enhanced energy restructuring. Pearson correlation analysis showed that traffic emissions were the main source of heavy metals. The Cr(VI) concentrations were 1.53 and 1.92 ng/m3 for urban and suburban sites, respectively, exceeding the national ambient air quality standards limit of 0.025 ng/m3. Secondary inorganic aerosols, traffic emissions, and secondary organic aerosols were the dominant contributors to PM2.5 in Zibo, with the total contributions from these three sources accounting for approximately 80% of PM2.5 and the remaining 20% attributed to traffic emissions. The non-carcinogenic risks from crustal dust for children were 2.23 and 1.15 in urban and suburban areas, respectively, exceeding the safe limit of 1.0 in both locations, as was the case for adults in urban areas. Meanwhile, the carcinogenic risks were all below the safe limit, with the non-carcinogenic and carcinogenic risks from traffic emissions being just below the limits. Strict control of precursor emissions, such as SO2, NOx, and VOCs, is a good way to reduce PM2.5 pollution resulting from secondary aerosols. Traffic control, limiting or preventing outdoor activities, and wearing masks during haze episodes may be also helpful in reducing PM2.5 pollution and its non-carcinogenic and carcinogenic health impacts in Zibo.

Vimentin Protein In Situ Expression Predicts Less Tumor Metastasis and Overall Better Survival of Endometrial Carcinoma.

Background: Vimentin, a cytoplasmic intermediate filament protein, has been recently identified to be a prognostic biomarker in some cancers. However, the function of vimentin in endometrial carcinoma (EC) remains unclear. Our study aimed at evaluating vimentin expression in EC and preliminarily exploring the role of vimentin in EC progression. Methods: In total, 341 EC patients who underwent surgical follow-up were enrolled in the retrospective study. Vimentin expression levels in EC tissues were analyzed using immunohistochemistry. Furthermore, the vimentin (VIM) gene expression levels in 547 samples in The Cancer Genome Atlas (TCGA) were analyzed. To examine the prognostic value of vimentin in EC, Kaplan-Meier survival analysis was performed, and a Cox model was established. Gene set enrichment analysis (GSEA) was also conducted using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database to explore the role of vimentin in EC progression. Results: Negative vimentin expression in EC correlated significantly with lymph node metastasis, deep myometrium invasion (MI), lymph vascular space invasion (LVSI), advanced Federation International of Gynecology and Obstetrics Association (FIGO) stages (III and IV), and high tumor grade. Vimentin negativity was more common in type 2 EC than that in type 1 EC, and vimentin-negative patients had poorer overall survival compared with vimentin-positive patients. The results of GSEA suggested that vimentin may interact with classical pathways in EC. Conclusions: Negative vimentin expression correlates with tumor metastasis and worse overall survival in EC, suggesting that it may be an excellent prognostic biomarker for this disease. The mechanism by which vimentin contributes to EC progression needs to be explored in the future.

[Source and Health Risk Assessment of PM2.5-Bound Metallic Elements in Road Dust in Zibo City].

To study the pollution characteristics, sources, and ecological and health risk of PM2.5-bound metallic elements in road dust in Zibo City, a total of 97 dust samples were collected in eight districts between October 2016 and May 2017, and particles smaller than 2.5 µm were suspended filtered using a resuspension system. Inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES) were used to investigate 18 metal elements within the dust samples. The results showed that the mass fraction of Ca[ω(Ca)] was highest with an average of 120307.7 mg·kg-1, which was 7.2 times higher than the soil background values for Shandong Province. The mean values of ω(Zn), ω(Cu), ω(Sb), and ω(Cd) were 13.9, 11.7, 13.3, and 29.6 times higher than the background values, respectively. The geo-accumulation index (Igeo) indicated high levels of Cd, Zn, Cu, and Sb pollution, especially in winter. Enrichment factors (EFs) also indicated high concentrations of Cd, Zn, Sb, and Cu in the road dust, which were notably affected by human activities. Principal component analysis (PCA) showed that biomass combustion, coal burning, vehicle emissions, iron and steel smelting, and soil dust are the five main sources of metal elements in road dust in Zibo City. The potential ecological risk of Cd and the total potential risk were extremely high during three seasons and was highest in winter. Health risk assessment showed that As and Pb had a non-carcinogenic risk for children, while Cr presents a carcinogenic risk. In conclusion, pollution from PM2.5-bound metallic elements in road dust in Zibo City is derived from anthropogenic sources and is most severe during winter. Importantly, the levels of pollution detected represent potential ecological risk as well as some non-carcinogenic and carcinogenic risks for children. Therefore, the source control of road dust requires particular attention.

Study on performance degradation and damage modes of thin-film photovoltaic cell subjected to particle impact.

It has been a key issue for photovoltaic (PV) cells to survive under mechanical impacts by tiny dust. In this paper, the performance degradation and the damage behavior of PV cells subjected to massive dust impact are investigated using laser-shock driven particle impact experiments and mechanical modeling. The results show that the light-electricity conversion efficiency of the PV cells decreases with increasing the impact velocity and the particles' number density. It drops from 26.7 to 3.9% with increasing the impact velocity from 40 to 185 m/s and the particles' number densities from 35 to 150/mm2, showing a reduction up to 85.7% when being compared with the intact ones with the light-electricity conversion efficiency of 27.2%. A damage-induced conversion efficiency degradation (DCED) model is developed and validated by experiments, providing an effective method in predicting the performance degradation of PV cells under various dust impact conditions. Moreover, three damage modes, including damaged conducting grid lines, fractured PV cell surfaces, and the bending effects after impact are observed, and the corresponding strength of each mode is quantified by different mechanical theories.

Heterodyned photoacoustic effect generated by irradiation of single particles by two laser beams modulated at different frequencies.

When a modulated light beam is absorbed by an incompressible particle, the photoacoustic effect can take place through heat diffusion into the surrounding fluid followed by thermal expansion and the generation of sound. When two laser beams modulated at different frequencies irradiate a particle in aqueous solution, the effect of one laser is to modulate the thermal expansion coefficient of the solution in the proximity of the particle at its modulation frequency. Heat diffusion into the same region of fluid from absorption of radiation from the second laser takes place in fluid where the thermal expansion coefficient is modulated so that the photoacoustic effect is produced at the sum and difference frequencies of the two lasers. Here, a theory for the photoacoustic effect at the heterodyne frequency for a single particle and the corresponding experiments with carbon particles of different sizes are reported.

Differential Infrared Pyrometry for Determination of Microkelvin Temperature Variations.

Precise measurement of temperature is important in studies of chemical and biological systems as reaction kinetics are almost universally sensitive to temperature. However, the use of conventional temperature probes can introduce an exogenous temperature disturbance resulting in measurement artifacts. Infrared pyrometry is a noninvasive technique for temperature measurement, however, the challenge for current infrared pyrometry is low sensitivity to small temperature variations, which in many cases precludes determination of key diagnostic information. Here, we report a sensitive differential infrared pyrometer based on spatial modulation using a resonant oscillating mirror, which enables a sensitivity to temperature variations on the microkelvin scale. The instrument is employed to monitor minuscule heat evolution in an acid-base reaction and the decomposition of H2O2 by bovine liver catalase. The instrument holds great promise for monitoring the dynamics of heat evolution in a range of chemical and biological systems in a completely noninvasive manner.

[Source Apportionment and Pollution Characteristics of PM2.5 During the Two Heavy Pollution Episodes in the Winter of 2016 in a Typical Logistics City].

To characterize the chemical composition of PM2.5 and the formation of pollution during a heavy pollution episode in the winter in a typical logistics city, PM2.5 samples were collected from December 2016 to January 2017 at six sampling sites, and the water-soluble ions, elements, and carbon components were determined. The results showed that the average concentration of PM2.5 was (145.2±87.8) µg·m-3 during the whole sampling period, of which 82% of daily average concentrations were above class Ⅱ of the national standards. The average concentrations of PM2.5 during the two heavy pollution episodes were (187.3±79.8) and (205.3±92.0) µg·m-3, which were 5.4 and 5.9 times, respectively, as high as class Ⅱ of the national standard. The results of the chemical composition of the PM2.5 showed that secondary water-soluble inorganic ions (SO42-, NO3-, and NH4+) were the main components of PM2.5 in winter (51.2% of PM2.5 mass concentration), followed by organic matter (OM, 23.8%), and mineral dust (12.7%). Combined with the change trend and accumulation rate of chemical components during the pollution episode, we discovered that the increasing of SNA and OM led to PM2.5 pollution in the first episode, while the growth of SNA caused the second pollution episode. This was further verified by the synchronous change of SOR, NOR, and the OC/EC ratio. PMF analysis indicated that mixed sources of secondary particulate matter and biomass combustion (50.0%), coal combustion (16.8%), vehicles (12.9%), fugitive dust (10.0%), industry (5.3%) and soil dust (5.0%), were the main sources of PM2.5 of Linyi city in the winter. Compared with the average concentration over the whole sampling period, the contribution of secondary particles during the two pollution episodes was significantly increased. This indicates that the formation and accumulation of secondary particulate matter under static and humid meteorological conditions were the main influencing factors during the heavy pollution episodes.

Photoacoustic trace detection of gases at the parts-per-quadrillion level with a moving optical grating.

The amplitude of the photoacoustic effect for an optical source moving at the sound speed in a one-dimensional geometry increases linearly in time without bound in the linear acoustic regime. Here, use of this principle is described for trace detection of gases, using two frequency-shifted beams from a CO2 laser directed at an angle to each other to give optical fringes that move at the sound speed in a cavity with a longitudinal resonance. The photoacoustic signal is detected with a high-[Formula: see text], piezoelectric crystal with a resonance on the order of [Formula: see text] kHz. The photoacoustic cell has a design analogous to a hemispherical laser resonator and can be adjusted to have a longitudinal resonance to match that of the detector crystal. The grating frequency, the length of the resonator, and the crystal must all have matched frequencies; thus, three resonances are used to advantage to produce sensitivity that extends to the parts-per-quadrillion level.

Photoacoustic effect generated by moving optical sources: Motion in three dimensions.

Although the photoacoustic effect is commonly produced through use of pulsed or amplitude-modulated radiation, it can also be generated by a steady source moving in space. Here, the properties of the photoacoustic effect generated by moving sources in three dimensions are investigated. The mathematics for the moving photoacoustic point source are shown to be closely related to that for derivation of the Lienard-Wiéchert potential for a moving point charge. The cases of rectilinear motion with the speeds lower than, equal to, and greater than the sound speed, as well as a point source oscillating in space are reported. Of note is that a bounded amplification effect is found for a Gaussian source moving at the sound speed, which is in contrast to the unbounded amplification seen in a one-dimensional geometry.

Evaluation of emergency pediatric tracheal intubation by pediatric anesthesiologists on inpatient units and the emergency department.

BACKGROUND AND OBJECTIVES: There are limited data on pediatric emergency tracheal intubation on inpatient units and in the emergency department by anesthesiologists. This retrospective cohort study was designed to describe the frequency of difficult intubation and adverse events associated with emergency tracheal intubation performed by pediatric anesthesiologists in a large children's hospital. METHODS: All emergency tracheal intubation on inpatient units and the emergency department performed by pediatric anesthesiologists over a 7-year period in children <18 years were identified by querying our perioperative clinical information system. Medical records were comprehensively reviewed to describe the emergency intubation process and outcomes. RESULTS: One hundred and thirty-two intubations from 120 children (median age 3.3 years) were eligible. The majority of emergency tracheal intubations were successful with 1-2 laryngoscopy attempts, while 14 (10.6%) were difficult. Despite grade 3 view in 3/14 cases, the airway was secured after multiple direct laryngoscopy attempts. Eleven required use of an alternative airway device to secure the airway. A preexisting airway abnormality or craniofacial abnormality was present in 57% of cases with difficult intubation including half with micrognathia or retrognathia. Major intubation-related adverse events such as aspiration, occurred in 5 (3.8%) emergency tracheal intubations. Mild-to-moderate intubation-related adverse events occurred in 23 (17.4%) emergency tracheal intubations including mainstem bronchus intubation (13.6%). CONCLUSION: A significant rate of difficult intubation and mild-to-moderate intubation-related adverse events were found in emergency tracheal intubations on inpatient units and the emergency department in children performed by a pediatric anesthesiology emergency airway team. Difficult intubation was observed frequently in children with preexisting airway and craniofacial abnormalities and often required the use of an alternative airway device to successfully secure the airway.

Flexible and stretchable lithium-ion batteries and supercapacitors based on electrically conducting carbon nanotube fiber springs.

The construction of lightweight, flexible and stretchable power systems for modern electronic devices without using elastic polymer substrates is critical but remains challenging. We have developed a new and general strategy to produce both freestanding, stretchable, and flexible supercapacitors and lithium-ion batteries with remarkable electrochemical properties by designing novel carbon nanotube fiber springs as electrodes. These springlike electrodes can be stretched by over 300 %. In addition, the supercapacitors and lithium-ion batteries have a flexible fiber shape that enables promising applications in electronic textiles.

Elastic and wearable wire-shaped lithium-ion battery with high electrochemical performance.

A stretchable wire-shaped lithium-ion battery is produced from two aligned multi-walled carbon nanotube/lithium oxide composite yarns as the anode and cathode without extra current collectors and binders. The two composite yarns can be well paired to obtain a safe battery with superior electrochemical properties, such as energy densities of 27 Wh kg(-1) or 17.7 mWh cm(-3) and power densities of 880 W kg(-1) or 0.56 W cm(-3), which are an order of magnitude higher than the densities reported for lithium thin-film batteries. These wire-shaped batteries are flexible and light, and 97 % of their capacity was maintained after 1000 bending cycles. They are also very elastic as they are based on a modified spring structure, and 84 % of the capacity was maintained after stretching for 200 cycles at a strain of 100 %. Furthermore, these novel wire-shaped batteries have been woven into lightweight, flexible, and stretchable battery textiles, which reveals possible large-scale applications.

Integrated polymer solar cell and electrochemical supercapacitor in a flexible and stable fiber format.

An all-solid-state, coaxial and self-powered "energy fiber" is demonstrated that simultaneously converts solar energy to electric energy and further stores it. The "energy fiber" is flexible and can be scaled up for the practical application by the well-developed textile technology, and may open a new avenue to future photoelectronics and electronics.

Flexible and weaveable capacitor wire based on a carbon nanocomposite fiber.

A flexible and weaveable electric double-layer capacitor wire is developed by twisting two aligned carbon nanotube/ordered mesoporous carbon composite fibers with remarkable mechanical and electronic properties as electrodes. This capacitor wire exhibits high specific capacitance and long life stability. Compared with the conventional planar structure, the capacitor wire is also lightweight and can be integrated into various textile structures that are particularly promising for portable and wearable electronic devices.

Hemodynamic changes in children with Down syndrome during and following inhalation induction of anesthesia with sevoflurane.

STUDY OBJECTIVE: To evaluate whether children with Down Syndrome are at increased risk of bradycardia and hypotension during and following sevoflurane induction. DESIGN: Retrospective study. SETTING: University-affiliated children's hospital. MEASUREMENTS: The records of children with Down syndrome and a sample matched by age, congenital heart defect, and ASA physical status, were searched. Demographics, history of Down syndrome or congenital heart anomaly, heart rate (HR), mean arterial pressure (MAP), and end-tidal concentration of sevoflurane (EtSevo) at baseline and following induction were recorded. MAIN RESULTS: 96 children with Down syndrome were identified from 11,201 pediatric anesthetics (< 1%). Demographics were similar in the matched sample. The Down syndrome group was more likely to experience bradycardia and had greater decreases in HR from baseline. These findings were similar for children with or without congenital heart defects. There were no differences between groups in the number who were treated with a pharmacologic agent. CONCLUSION: A significantly higher prevalence and degree of bradycardia occurred in children with Down syndrome during and following sevoflurane induction, which was corrected by decreasing the concentration of sevoflurane and airway manipulation.