Search

Rapid development of railway industry makes safety increasingly important. Wear, contact-impact, fatigue and corrosion are important factors initiating rail track degradation from the beginning, while corrosion attracts far less attention than other issues. Direct corrosion cost due to railway corrosion in China was 18.88 billion RMB, so corrosion definitely deserves more attention. This work has reviewed studies focussing exclusively on rail corrosion, including corrosion forms, protection and detection technologies. General corrosion on large rail surface is not limiting, while crevice corrosion between rail and liner, resulting in thinning of rail foot, is regarded significant but overlooked. Moreover, reciprocating micro-motion between rail foot and liner mechanically assists the ongoing of crevice corrosion. However, it was mentioned in very few reports and not investigated extensively. Coating and surface modification may be applied for mitigation of rail track corrosion. The weakness of coating is poor mechanical properties, while surface modification, including thermal spraying and laser cladding, may be a better way. Development of novel steel is another effective method, but loss of mechanical properties becomes obstacles for practical applications. Ultrasonic and infrared have been applied for detection, while more advanced technologies are promising. Suggestions are made on specific research topics in this field. [ABSTRACT FROM AUTHOR]

Fine roots of plants play an important role in terrestrial ecosystems. There is a close association between the anatomical characteristics and physiological and ecological functions of plants, but we still have a very limited knowledge of anatomical traits. For example, (1) we do not know if herbs and grasses have anatomical patterns similar to those of woody plants, and (2) the variation among different woody plants in the same ecosystem is unclear. In the present study, we analysed the anatomical structures of the fine root systems of various groups of vascular plants (ferns, eudicot herbs, monocots and woody plants) from the same ecosystem (a natural secondary forest on Mao'er Mountain, Heilongjiang, China) to answer the following questions: (1) How does the anatomy of the fine roots change with root order in various plant groups in the same ecosystem? (2) What is the pattern of variation within group? The results show that anatomical traits can be divided into 3 categories: traits that indicate the root capacity to transport resource along the root (stele diameter, xylem cell diameter and xylem cell area); traits that indicate absorptive capacity cortical thickness, (the number of cortical cell layers and the diameter of cortical cells); and traits that are integrated indicators (diameter and the stele to root diameter ratio). The traits indicate the root capacity to transport resource along the root order is generally similar among groups, but absorptive capacity is very different. The shift in function is the main factor influencing the fine root anatomy. Some traits show large variation within groups, but the variations in other traits are small. The traits indicate that the lower-order roots (absorbing roots) in distinct groups are of the first one or two root order in ferns, the first two or three orders in eudicot herbs, the first (only two root orders) or first two orders (more than three root orders) in monocots and the first four or five root orders in woody plants and the other roots are higher-order roots (transport roots). The result will helpful to understand the similarities and differences among groups and the physiological and ecological functions of plant roots. [ABSTRACT FROM AUTHOR]

Aims: The variability patterns of fern root characteristics have seldom been studied. Here we explored variability in root morphology, histology and chemistry among fern species of temperate forest, and compared the observed patterns with those of seed plants. Methods: We sampled nine herbaceous fern species from temperate forest in northeastern China, and measured root morphological, histological and chemical characteristics across branch orders for each species. Results: All nine fern species had 3 or 4 root orders. With increasing root order, diameter, tissue density, cortical thickness and vascular cylinder diameter increased, while specific root length (SRL) and tissue nitrogen concentration decreased. These were similar to the variability patterns that have been reported for seed plants, except for cortex. Like seed plants, nine fern species showed close relationships among root morphological, histological and chemical characteristics in first-order roots, such as diameter and cortex, tissue density and nitrogen concentration, suggesting that the general linkage between root structure and function exists in all vascular plants. Conclusions: The observed variation within fern root systems is comparable to the reported variation in seed plants, indicating that the same functional constraints control the evolution and development of root systems in vascular plants belonging either to the fern or seed plant lineages. [ABSTRACT FROM AUTHOR]

Schematic model of corrosion causes and failure mechanisms on the inner wall of the product oil pipeline. • The inner corrosion behavior of high strength product oil pipelines was studied, and some new ideas were put forward. • The three pipeline steels have the same corrosion mechanism. • X80 pipeline steel has better adaptability under the condition of corrosion in the product oil pipeline. • It is more practical to accelerate the development of X80 pipeline steel to make it more applicable to the construction of the product oil pipelines. Pipeline transportation is one of the five major modes of transportation. Inner corrosion problems in product oil pipelines are widespread but have not received attention, and high strength product oil pipelines are rarely used in China. In this paper, morphology and composition analysis and electrochemical methods were used to study the corrosion behaviors and characteristics of API 5L X65, X70 and X80 steel product oil pipelines. The feasibility of using high strength product oil pipelines in the transportation environment of product oil under the condition of inner corrosion is discussed, and the support for the safe operation of product oil pipelines is provided. The research results show that X80 pipeline steel has advantages over X65 and X70 pipeline steel. In the simulated liquid system of sediments in product oil pipeline, as the immersion time increases, the corrosion rate of X65, X70 and X80 pipeline steels shows a trend from high to low. Morphological analysis and electrochemical analysis showed that X80 pipeline steel showed better performance and adaptability to the environment, and its aerobic corrosion reaction was slower than that of X65 and X70 pipeline steel. X-ray photoelectron spectroscopy (XPS) results show that the three pipeline steels have the same corrosion mechanism, and all of them form Fe 2 O 3 , FeOOH, FeCO 3 , and FeS. The corrosion process is similar but the speed is different. This is attributed to the more corrosion-resistant trace elements in the X80 pipeline steel composition and the structure more compact. The application of high strength API 5L X80 steel in the product oil pipeline is still in its infancy, and it will be more practical to accelerate the development of API 5L X80 steel to make it more applicable to the construction of product oil pipelines. [ABSTRACT FROM AUTHOR]

Background: Sperm quality, including semen volume, sperm count, concentration, and total and progressive motility (collectively, "semen parameters"), has declined in the recent decades. Computer-assisted sperm analysis (CASA) provides sperm kinematic parameters, and the temporal trends of which remain unclear. Our objective is to examine the temporal trend of both semen parameters and kinematic parameters in Shanghai, China, in the recent years., Methods: This retrospective study analyzed semen parameters and kinematic parameters of 49,819 men attending our reproductive center by using CASA during 2015-2021. The total sample was divided into two groups: samples that surpassed the WHO guideline (2010) low reference limits ("above reference limit" group, ARL; n = 24,575) and samples that did not ("below reference limit" group, BRL; n = 24,614). One-way analysis of variance, Kruskal-Wallis test, independent samples t -test, and covariance analysis were used to assess the differences among groups. Year, age, and abstinence time were included in the multiple linear regression model of the ARL group to adjust the confounders and depict the trends in sperm quality., Results: Among all the total sample and the ARL and BRL groups, the age of subjects increased in recent years. Semen volume and sperm count showed declined tendency with years in the total sample, the ARL and BRL groups, and the subgroup of age or abstinence time, whereas sperm velocities showed increased tendency with years on the contrary. The multiple linear regression model of the ARL group, adjusting for age and abstinence time, confirmed these trends. Semen volume (β1= -0.162; CI: -0.172, -0.152), sperm count (β1= -9.97; CI: -10.813, -9.128), sperm concentration (β1 = -0.535; CI: -0.772, -0.299), motility (β1 = -1.751; CI: -1.830, -1.672), and progressive motility (β1 = -1.12; CI: -0.201, -0.145) decreased with year, whereas curvilinear line velocity (VCL) (β1 = 3.058; CI: 2.912, 3.203), straight line velocity (VSL) (β1 = 2.075; CI: 1.990, 2.161), and average path velocity (VAP) (β1 = 2.305; CI: 2.224, 2.386) increased over time (all p < 0.001). In addition, VCL, VSL, and VAP significantly declined with age and abstinence time., Conclusion: The semen parameters declined, whereas the kinematic parameters increased over the recent years. We propose that, although sperm count and motility declined over time, sperm motion velocity increased, suggesting a possible compensatory mechanism of male fertility., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Lu, Wu, Wang, Yu, Wang, Tang and Zhou.)

Corrosion had aroused extensive concern and attention because it was an unavoidable problem for marine equipment and facilities in service. However, the current status and development trend of marine environment corrosion research had seldom been systematically studied. Therefore, it was encouraged to use bibliometrics and information visualization analysis methods to conduct bibliometric analysis of related publications in the field of marine environment corrosion based on HistCite, CiteSpace, and VOSviewer software programs. Compared with the traditional comments of researchers in this field, this research provided a direction for the development of quantitative analysis and visualization of marine environment corrosion on a large scale. The results showed that the overall focus of research in the field of marine environment corrosion continued to increase from 1900 to 2019. China had the highest publication productivity, the USA had the highest h-index value and the second highest average citations per item value, Materials Science was the most popular subject category, Corrosion Science was the main journal and Melchers RE was the author with the most output contributions. This research also exhibited four hot spots in this field. In addition, this work could help new researchers to find research directions and identify research trends and frontiers in the field of marine environment corrosion by tracing the research hotspots of topic categories, countries, institutions, journals, authors, and publications in recent years., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The aim of this study was to explore the effects of an enteral nutrition (EN) feeding protocol in critically ill patients., Methods: This was a prospective multi-center before-after study. We compared energy related and prognostic indicators between the control group (pre-implementation stage) and intervention group (post-implementation stage). The primary endpoint was the percentage of patients receiving EN within 7 days after ICU admission., Results: 209 patients in the control group and 230 patients in the intervention group were enrolled. The implementation of the EN protocol increased the percentage of target energy reached from day 3 to day 7, and the difference between two groups reached statistical significance in day 6 (P = .01) and day 7 (P = .002). But it had no effects on proportion of patient receiving EN (P = .65) and start time of EN (P = .90). The protocol application might be associated with better hospital survival (89.1% vs 82.8%, P = .055) and reduce the incidence of EN related adverse (P = .004). There was no difference in ICU length of stay, duration of mechanical ventilation and ICU cost., Conclusion: The implementation of the enteral feeding protocol is associated with improved energy intake and a decreased incidence of enteral nutrition related adverse events for critically ill patients, but it had no statistically beneficial effects on reducing the hospital mortality rate. Trial registration ClinicalTrials.gov, NCT02976155. Registered November 29, 2016- Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02976155., Competing Interests: Declaration of Competing Interest No conflict of interest., (Copyright © 2019 Elsevier Inc. All rights reserved.)