Search

Abstract Background Selecting the optimal non-invasive diagnostic model for MASLD (Metabolic Dysfunction-Associated Steatosis Liver Disease) and steatosis progression is a critical issue given the variety of available models. We aimed to compare the performance of eight clinical prediction models for diagnosing and predicting the progression of hepatic steatosis using MRI-PDFF (Magnetic Resonance Imaging-Derived Proton Density Fat Fraction), and validate the findings with FibroScan and histopathological results. Methods In this study, 846 participants were initially enrolled, with 108 undergoing liver biopsy and 706 completing one-year follow-up, including 26 who underwent repeat biopsy. We calculated scores for eight clinical prediction models (FAST, KNAFLD, HSI, FLI, Liver Fat Score, Liver Fat Equation, BAAT, LAP) using collected clinical data and defined steatosis progression as a 30% relative increase in liver fat content (LFC) measured by MRI-PDFF. CAP(Controlled Attenuation Parameter) and LSM (Liver Stiffness Measurement) were obtained by Fibroscan. MRI-PDFF served as the reference standard for evaluating model accuracy, and sensitivity analyses were performed using liver biopsy and Fibroscan results. Results Among the eight clinical models, NAS (nonalcoholic fatty liver disease activity score) showed higher correlation with the FAST and KNAFLD models (r: 0.62 and 0.52, respectively). Among the whole cohort (N = 846), KNAFLD was the best model for predicting different degrees of hepatic steatosis (AUC = 0.84). When the KNAFLD score was above 2.935, LFC was significantly higher (4.4% vs. 19.7%, P -0.02, LFC increased (8.6–10.9%, P

IntroductionOur understanding of the regulatory mechanisms that govern the development of sexual characteristics in sturgeon, particularly the Chinese sturgeon (Acipenser sinensis), is limited. Foxl2, a member of the forkhead/HNF-3-related transcription factor family, is known for its role in precise gene regulation within specific tissues and its control over ovarian aromatase, a key enzyme in ovarian development and maturation. This study aimed to investigate the sexually dimorphic expression of foxl2 during the molecular and morphological sex differentiation stages in Chinese sturgeon.MethodsWe successfully isolated the full-length cDNAs of foxl2 in Chinese sturgeon. We then examined the expression profiles of this gene across various somatic tissues in both female and male specimens.ResultsFoxl2 was predominantly expressed in the ovulatory organs of two-year-old Chinese sturgeon, with significantly lower expression in other somatic tissues. We observed sexual dimorphism in foxl2 expression within gonads that had achieved morphological differentiation.DiscussionThe results suggest that foxl2 expression is intricately linked to the process of ovarian differentiation in Chinese sturgeon. Furthermore, we propose that the mRNA quantities of foxl2 could serve as an accurate biomarker for sex determination in sturgeon during their early growth stages.

Fatty acyl desaturases (Fads) are crucial enzymes that catalyze the rate-limiting step of the desaturation reactions by introducing a double bond into to pre-existing fatty acyl chains. As a group of key enzymes involved in the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFAs), Fads have been well investigated in teleost fishes but they are still rarely known in chondrichthyans. In this study, we first identified a fatty acyl desaturases gene (fads2) from the Chinese sturgeon (Acipenser sinensis), a critically endangered cartilaginous species in China, by combining with bioinformatic analyses and molecular cloning methods. Then, the spatio-temporal distribution patterns, functional characteristics and transcriptional changes of this gene in response to different nutritional conditions were investigated. The coding sequences of the fads2 gene was 1350 bp in length, encoding a protein of 449 amino acids. Multiple protein sequences alignment, genetic synteny and phylogenetic analyses further suggested that fads2 gene was evolutionary conserved. Functional characterization by heterologous expression in yeast showed that Fads2 exhibited Δ6 and Δ8 bifunctional desaturation activities, and possessed capacities to convert 18:2n-6, 18:3n-3, 20:2n-6 and 20:3n-3–18:3n-6, 18:4n-3, 20:3n-6 and 20:4n-3, respectively. In vivo experiment, diets full with C18 PUFA but not LC-PUFA significantly induced the expression levels of fads2 in Chinese sturgeon brain and liver tissues. Our findings suggest that fads2 is an evolutionary and functionally conserved desaturase in Chinese sturgeon, and which plays important roles in regulation of endogenous LC-PUFAs biosynthesis. In summary, these findings will provide a new insight into the evolutionary history of key enzymes of LC-PUFA biosynthesis in vertebrates.

The study focuses on the critically endangered Dabry’s sturgeon (Acipenser dabryanus), a species on the brink of extinction in the wild. This research investigates the role of the Forkhead box protein L2 (foxl2) in the gonadal development and differentiation of this species. The foxl2 gene, known for its role in various physiological processes, including sexual maturation, is hypothesized to play a significant role in the sex differentiation of Dabry’s sturgeon. This study cloned the full-length cds sequence of the foxl2 gene and analyzed its expression across various tissues, focusing on its response to estradiol treatment. Our findings indicate that foxl2 is predominantly expressed in ovaries and shows a dose-dependent response to estradiol, suggesting its potential role in ovarian differentiation. This research underscores the importance of foxl2 in understanding reproductive biology and offers a foundation for future conservation strategies.

Abstract Background Resolving the phylogeny of rapidly radiating lineages presents a challenge when building the Tree of Life. An Old World avian family Prunellidae (Accentors) comprises twelve species that rapidly diversified at the Pliocene–Pleistocene boundary. Results Here we investigate the phylogenetic relationships of all species of Prunellidae using a chromosome-level de novo assembly of Prunella strophiata and 36 high-coverage resequenced genomes. We use homologous alignments of thousands of exonic and intronic loci to build the coalescent and concatenated phylogenies and recover four different species trees. Topology tests show a large degree of gene tree-species tree discordance but only 40–54% of intronic gene trees and 36–75% of exonic genic trees can be explained by incomplete lineage sorting and gene tree estimation errors. Estimated branch lengths for three successive internal branches in the inferred species trees suggest the existence of an empirical anomaly zone. The most common topology recovered for species in this anomaly zone was not similar to any coalescent or concatenated inference phylogenies, suggesting presence of anomalous gene trees. However, this interpretation is complicated by the presence of gene flow because extensive introgression was detected among these species. When exploring tree topology distributions, introgression, and regional variation in recombination rate, we find that many autosomal regions contain signatures of introgression and thus may mislead phylogenetic inference. Conversely, the phylogenetic signal is concentrated to regions with low-recombination rate, such as the Z chromosome, which are also more resistant to interspecific introgression. Conclusions Collectively, our results suggest that phylogenomic inference should consider the underlying genomic architecture to maximize the consistency of phylogenomic signal.

El Niño is one of the most significant global climatic phenomena affecting the East Asian atmospheric circulation and climate. This study uses multi-source datasets, including observations and analyses, and statistical methods to investigate the variations and potential causes of boreal spring precipitation anomalies in eastern China under different El Niño sea surface temperature conditions, namely, the Eastern Pacific and Central Pacific (EP and CP) El Niño cases. The findings reveal that, particularly along the Yangtze–Huaihe valley, spring precipitation markedly increases in most regions of eastern China during the EP El Niño decaying stages. Conversely, during the CP El Niño decaying stages, precipitation anomalies are weak, with occurrences of weak negative anomalies in the same regions. Further analyses reveal that during the decaying spring of different El Niño cases, differences in the location and strength of the Northwest Pacific (NWP) abnormal anticyclone, which is associated with the central–eastern Pacific warm sea surface temperature anomaly (SSTA), result in distinct anomalous precipitation responses in eastern China. The SSTA center of the EP El Niño is more easterly and stronger. In the meantime, NWP abnormal anticyclones are more easterly and have a broader range, facilitating water vapor transport over eastern China. By contrast, the CP El Niño SSTA center is westward and relatively weaker, leading to a relatively weak, westward, and narrower anomalous NWP anticyclone that causes less significant water vapor transport anomalies in eastern China. This paper highlights the diverse impacts of El Niño diversity on regional atmospheric circulation and precipitation, providing valuable scientific references for studying regional climate change in East Asia.

Enhancing or protecting sperm motility has always been a pivotal approach to improving the ewe pregnancy rate. Sperm motility is highly susceptible to the immune status of the reproductive tract. Neutrophil extracellular traps (NETs) have been demonstrated to capture sperm and impair its motility in human, swine, and goat species. Quercetin is a flavonoid derived from Cuscuta Chinensis Lam., which can protect sperm from oxidative damage. In this study, we investigated whether inflammation decreases sperm motility and tried to clarify the potential protective mechanism of quercetin on goat sperm motility. Sperm-triggered NETs were analyzed by immunofluorescence analysis. Sperm acrosome integrity was detected by using giemsa staining. Quercetin exhibited no cytotoxicity towards sperm and PMNs within the concentration range of 20–80 μM. PMNs impaired both the survival rate and rapid linear motility of sperm, while quercetin significantly enhanced these parameters. PMNs captured sperm through NETs composed of DNA, citrullinated histone 3 (citH3), and neutrophil elastase (NE); however, quercetin effectively inhibited the release of sperm-stimulated NETs. The stimulation of PMNs with sperm resulted in a significant increase in levels of ROS and MDA, which decreased by quercetin. Moreover, PMNs caused integrity violation to both the plasma membrane and acrosome in sperm; this effect was significantly alleviated by quercetin. In conclusion, quercetin effectively ameliorated PMN-reduced sperm motility through the inhibition of NETs and oxidative stress, and preserving sperm plasma membrane and acrosome integrity, thereby providing preliminary insights into the underlying mechanisms and theoretical support for the development of potential sperm protectors.

ABSTRACT: Gliotoxin (GT) belongs to the epipolythiodioxopiperazine (ETP) family, which is considered a crucial virulence determinant among the secondary metabolites produced by Aspergillus fumigatus. The metabolites are commonly found in food and feed, contributing to the invasion and immune escape of Aspergillus fumigatus, thereby posing a significant threat to the health of livestock, poultry, and humans. Heterophil extracellular traps (HETs), a novel form of innate immune defense, have been documented in the chicken's innate immune systems for capturing and eliminating invading microbes. However, the effects and mechanisms of GT on the production of duck HETs in vitro remain unknown. In this study, we first confirmed the presence of HETs in duck innate immune systems and further investigated the molecular mechanism underlying GT-induced HETs release. Our results demonstrate that GT can trigger typical release of HETs in duck. The structures of GT-induced HETs structures were characterized by DNA decoration, citrullinated histones 3, and elastase. Furthermore, NADPH oxidase, glycolysis, ERK1/2 and p38 signaling pathway were found to regulate GT-induced HETs. In summary, our findings reveal that gliotoxin activates HETs release in the early innate immune system of duck while providing new insights into the immunotoxicity of GT towards ducks.

ABSTRACT: In the large poultry industry, where farmed chickens are fed at high density, the prevalence of pathogens and repeated vaccinations induce immune stress, which can significantly decrease the production performance and increase the mortality. This study was designed to shed light on the molecular mechanisms and metabolic pathways involved in immune stress through an in-depth analysis of transcriptomic and metabolomic changes in jejunum samples from the broilers. Two groups were established for the experiment: a control group and an LPS group. LPS group received an intraperitoneal injection of LPS solution at a dose of 250 μg per kg at 12, 14, 33, and 35 d of age, whereas the control group received a sterile saline injection. The severity of immune stress was assessed using the Disease Activity Index. A jejunal section was collected to measure the intestinal villus structure (villus length and crypt depth). RNA sequencing and metabolomics data analysis were conducted to reveal differentially expressed genes and metabolites. The results showed that the DAI index was increased and jejunal villus height/crypt depth was decreased in the LPS group. A total of 96 differentially expressed genes and 672 differentially accumulating metabolites were detected in the jejunum by LPS group compared to the control group. The comprehensive analysis of metabolomic and transcriptomic data showed that 23 pathways were enriched in the jejunum and that appetite, nutrient absorption, energy and substance metabolism disorders and ferroptosis play an important role in immune stress in broilers. Our findings provide a deeper understanding of the molecular and metabolic responses in broilers to LPS-induced immune stress, suggesting potential targets for therapeutic strategies to improve the production performance of broiler chickens.

Elongases of very-long-chain fatty acids (Elovls) are critical rate-limiting enzymes that are involved in LC-PUFA biosynthesis through catalyzing the two-carbon elongation of a pre-existing fatty acyl chain. Thus far, several Elovls have been extensively studied in teleost. However, the functional and physiological roles of Elovls in chondrichthyans have rarely been reported. In this study, we identified and characterized elovl2 from the endangered Chinese sturgeon (Acipenser sinensis) by whole genome scanning. The results show that the coding sequence of elovl2 was 894 bp in length, for a putative protein of 297 amnio acids. Comparative genomic analyses indicated that Chinese sturgeon elovl2 was evolutionarily conserved. Functional characterization in yeast demonstrated that the Chinese sturgeon Elovl2 could efficiently elongate C20 (ARA and EPA) and C22 (22:4n-6 and 22:5n-3) substrates, confirming its critical roles in LC-PUFA biosynthesis. Spatial and temporal expression analyses showed high elovl2 mRNA levels were detected in the liver and brain and showed an increase trend both in embryonic and post-hatching stages. Interestingly, diets with vegetable oils as lipid sources could significantly induce the high expression of elovl2 in Chinese sturgeon, implying that the endogenous LC-PUFA biosynthesis pathway was stimulated by lack of LC-PUFA in their diets. Our findings will enhance our understanding about the evolutionary and functional roles of elovl2 and provide novel insights into the LC-PUFA biosynthesis mechanism in vertebrates.

A secondary contact zone (SCZ) is an area where incipient species or divergent populations may meet, mate, and hybridize. Due to the diverse patterns of interspecific hybridization, SCZs function as field labs for illuminating the on-going evolutionary processes of speciation and the establishment of reproductive isolation. Interspecific hybridization is widely present in avian populations, making them an ideal system for SCZ studies. This review exhaustively summarizes the variations in unique traits within avian SCZs (vocalization, plumage, beak, and migratory traits) and the various movement patterns of SCZs observed in previous publications. It also highlights several potential future research directions in the genomic era, such as the relationship between phenotypic and genomic differentiation in SCZs, the genomic basis of trait differentiation, SCZs shared by multiple species, and accurate predictive models for forecasting future movements under climate change and human disturbances. This review aims to provide a more comprehensive understanding of speciation processes and offers a theoretical foundation for species conservation.

The precise evaluation of micro-crack sizes and locations is crucial for the safe operation of structures. Traditional detection techniques, however, suffer from low spatial resolution, making it difficult to accurately locate micrometer-scale cracks. A method and experimental study were proposed in this paper for identifying and locating micro-cracks using optical fiber strain sensing based on OFDR to address this issue. The feasibility of this method for micro-crack detection was verified by the combination of a polyimide-coated sensing optical fiber (PISOF) and tight sheath sensing optical fiber (TSSOF). A calculation method for micro-crack widths based on distributed optical fiber strain curves was established, and the test results of different optical fibers were compared. Through multiple verification experiments, it was found that the strain peak curves of both fiber types could accurately locate micro-cracks with a precision of 1 mm. Additionally, the crack widths could be obtained by processing the distributed strain curves using a computational model, enabling the accurate capture of micro-crack characteristics at the 10 μm level. A strong linear relationship was observed between the optical fiber stretching length and the crack width. Notably, the relative error in calculating the crack width from the strain curve of PI fiber was very small, while a linear relationship existed between the maximum strain value of the TSSOF and the crack width, allowing for the calculation of the crack width based on the maximum strain value. This further validated the feasibility of the method designed in this paper for the analysis of micro-crack characteristic parameters.

Defects occurring during the welding process of metal structural components directly affect their overall strength, which is crucial to the load-bearing capacity and durability of the components. This signifies the importance of accurate measurement and assessment of weld strength. However, traditional non-destructive testing methods such as ultrasonic and non-contact camera inspection have certain technical limitations. In response to these issues, this paper analyzes the detection principle of weld strength, revealing that weld defects reduce the effective area of the structural bearing section and cause stress concentration around them. Through repeated experimental data analysis of samples, strain distribution data along the one-dimensional direction caused by defects such as slag inclusion and porosity were obtained. Experimental results show that this method can identify defect types in welds, including slag inclusion, porosity, and unevenness, and accurately measure the location and size of defects with a precision of 0.64 mm, achieving qualitative analysis of weld defects. Additionally, by deploying distributed optical fiber sensors (DOFS) at different vertical distances along the weld direction, the propagation law of stress induced by different types of weld defects on samples was thoroughly analyzed. This further validates the advantages of this method in weld strength detection, including high spatial resolution, high sensitivity, and non-destructive measurement.

Objective To analyze the dermoscopic, reflectance confocal microscopic and histopathological features of 60 cases of atypical scabies. Methods Sixty cases of atypical scabies were analyzed in terms of demographic data, disease duration, and clinical, dermoscopic and reflectance confocal microscopic features. Skin histopathology was performed in 25 patients. Results A larger portion of the patients were aged 18-65 years (40.00%). Retirees, students and migrant workers accounted for 36.67% (22 cases), 20.00% (12 cases) and 18.33% (11 cases), respectively. The average disease duration was 38.12±22.56 days. Twenty-seven patients (45.00%) had a history of contact with patients with scabies. The commonly involved body sites were the palms (52 cases, 86.67%), abdomen (49 cases, 81.67%), wrists (44 cases, 73.33%) and vulva (38 cases, 63.33%). The most common skin rashes were papules (55 cases, 91.67%). Most patients had been misdiagnosed more than twice. The misdiagnoses included pruritus (17 cases, 28.33%), atopic dermatitis (16 cases, 26.67%) and eczema (14 cases, 23.33%). Over 60% of the misdiagnosed patients were treated with glucocorticoids (38 cases, 63.33%). Dermoscopic features included white burrows with triangular structures in brown or dark brown color at the end of burrows (48 cases) and gray-edge lines (42 cases). The typical mite body, burrows and feces were observed in 55 cases under a reflectance confocal microscope. Histopathologically, mites or eggs were seen in the stratum corneum in 17 out of 25 cases, and acute or subacute dermatitis with spongy edema were observed in 12 cases. Dermal infiltrates of eosinophils and lymphocytes were seen in 18 and 7 cases, respectively. Conclusions Atypical scabies displays divergent clinical features. Dermoscopy, reflectance confocal microscopy and histopathology are helpful in the diagnosis of atypical scabies.

The local deformation behavior and dynamic recrystallization of a shock compressed Mg-1Zn alloy was investigated through EBSD and TEM. Since dislocation slipping and twinning were locally suppressed during high strain-rate deformation, a more flexible kinking deformation was activated to adjusted local orientation and facilitate slipping and twinning within the kinks. Meanwhile, due to the slow heat dissipation that resulted in a local temperature elevating, the kink bands were evolved into deformation bands with recrystallized nano-grains. Such a finding provides a new perspective for kinking-facilitated nanocrystallization in Mg alloys and other anisotropic metallic materials.

With the continuous development of optical fiber access and other network infrastructure, cloud conference, online education, online office, cloud virtual-reality (VR) and other innovative services requiring high bandwidth are widely developed, which puts forward higher requirements on network bandwidth, delay, jitter and stability. Upgrading the legacy optical fiber network, building a gigabit optical broadband network, and promoting the further extension of optical fiber network to the enterprises help to improve the operation efficiency of information infrastructure and solve the problem of network coverage. High-quality business and enterprise broadband services can be realized, which stimulate potential consumer demand, and lay a solid foundation for the sustainable development of internet services. The business-enterprise full-optical network technology and the applications are studied, the related industrial chain and standardization progress are introduced, and the application mode and development trend are analyzed in this paper.

The unrelated parallel machine scheduling problem with sequence dependent setup times (UPMSP-SDST) addressed in this study refers to allocating jobs among a given number of machines and determining their processing sequence on each machine, to minimize the makespan (i.e., the maximum completion time). To deal with large-scale UPMSP-SDST with higher efficiency, this study presents an enhanced adaptive large neighborhood search (EALNS) algorithm with various destroy and repair operators and an efficiency-enhancement mechanism. The efficiency-enhancement mechanism is mainly composed of a simplified calculation method and a hierarchical comparison mechanism, which are applied to improve the implementation process of the greedy-based operators. The simplified calculation method obtains a new makespan by an incremental or decremental transformation, to avoid reluctant calculations. The hierarchical mechanism refines the comparison of different removal or insertion strategies of the operators, thereby arresting high-quality solutions with more metrics. The proposed algorithm is tested on 1640 instances, and numerical results demonstrate the superior performance of the EALNS over the existing methods, especially for large-scale problems. Notably, 834 instances’ best-known solutions are updated from this study. In addition, deep analysis of the impact of the distribution of setup time on the performance of the algorithm is provided, which further verifies the potential wide applicability of the proposed EALNS.

In large equivalent explosion tests, the method of calculating blast wave parameters by the plastic deformation angle of a cantilever beam can effectively avoid the problem of power supply, storage, communication, and low survival rate of conventional blast wave sensors. In this paper, by means of theoretical analysis and numerical simulation, the deformation response of a pure aluminum cantilever beam with different scaled distances is calculated, and the relationship between the plastic bending angle and blast wave parameters is obtained, which provides a novel and effective method for the measurement of blast wave parameters. The experimental results show that the deformation of the cantilever beam is mainly dominated by the impulse load and the error of this measurement method is within 15%. This method can provide a complementary approach to more precise but complex sensor measurement and can effectively evaluate the impulse in the explosion accident outside.

Cases of disseminated visceral Kaposi’s sarcoma (KS) after allogenic hematopoietic stem cell transplantation (HSCT) are very rare worldwide, and disseminated visceral KS is often rapidly progressive and life-threatening, especially in paediatric patients. Here, the case of a 6-year-old female patient with disseminated visceral KS after allogeneic HSCT for treating severe aplastic anaemia is presented. The authors encountered difficulties in making the diagnosis due to lack of experience, but the diagnosis was achieved relatively quickly and accurately using metagenomic next-generation sequencing. After tapering and withdrawal of immunosuppressant drugs, the patient's condition was controlled. In conclusion, although HSCT-related KS is very rare, it should be considered during differential diagnosis.

High-speed videogrammetric measurements are widely used on shaking tables. However, during progressive collapse experiments, the protective string used to ensure the safety of personnel and the shaking table, mandated by safety considerations, can partially occlude the structural model. To address the problem of inaccurate tracking of the ellipse targets in image sequences due to the partial occlusion, this paper proposes a novel mutually guided tracking method for the partial occlusion situations. Firstly, the strategy of loopback detection is proposed to eliminate the cumulative errors with the initial tracking model and to replace the initial results of the tracking with those from the loopback detection. Secondly, tiny offset compensation is used to solve the problem of deviations. The experimental results demonstrate that the proposed method can achieve single-point localization at the sub-millimeter level and interlayer localization at the millimeter level within partially occluded environments. It is important that the proposed method meets the requirements of experimental accuracy on shaking tables and ensures the safety of personnel and facilities.

With the rapid growth of 5G network traffic, the bearer requirement for 6-channel 25 Gbit/s fronthaul has become increasingly obvious.The main schemes and standardizations of fronthaul technology in the existing network were introduced.A novel bearer scheme based on CWDM and optical circulator to satisfy the requirements for 6-channel 25 Gbit/s fronthaul with low cost was proposed.The advantages and challenges of the scheme were analyzed.Tests in laboratory and pilots in actual network were introduced.

The effective distribution of relief to an emergency logistics system plays a crucial role during the disaster response phase. Considering stochastic characteristics of relief demand, this study investigates the robust optimization of a multi-objective multi-period location-routing problem for epidemic logistics, a special emergency logistics, with uncertain scenarios. A corresponding robust multi-objective multi-period optimization model is proposed, which aims to determine the optimal location of temporary relief distribution centres and route planning simultaneously. The optimization objectives include the total travel time, the total cost, and the disutility of relief service. To solve the above optimization model, a preference-inspired co-evolutionary algorithm with Tchebycheff decomposition (PICEA-g-td) is given. The performance of the proposed PICEA-g-td is evaluated by comparing it with NSGA-II, MOEA/D and PICEA-g. The experimental results show that the proposed algorithm performs better than the other three algorithms in terms of the solution quality. Finally, some useful management insights are obtained.

Gut microbial communities of animals play key roles in host evolution, while the relationship between gut microbiota and host evolution in Tibetan birds remains unknown. Herein, we sequenced the gut microbiota of 67 wild birds of seven species dwelling in the Tibetan wetlands. We found an obvious species-specific structure of gut microbiota among these plateau birds whose habitats were overlapped. Different from plateau mammals, there was no strict synergy between the hierarchical tree of gut microbial community and species phylogeny. In brown-headed gulls (Larus brunnicephalus) as an example, the structure of gut microbiota differed in different habitats, and the relative abundance of bacteria, such as Lactobacillus, Streptococcus, Paracoccus, Lachnospiraceae, and Vibrio, significantly correlated with altitude. Finally, we found various pathogenic bacteria in the birds of these plateau wetlands, and the interspecific differences were related to their diet and living environments.

In this paper, an L-band wideband quad-ridged waveguide orthomode transducer (OMT) for the Five hundred meter Aperture Spherical radio Telescope (FAST) is presented with a simple design principle. By designing two critical parts of the OMT separately and introducing matching rings into two orthogonal probes, an improved wideband performance has been realized successfully. The OMT is designed to operate across the 0.95GHz-1.9GHz band, and the simulation shows a return loss better than -20 dB for both polarizations, cross-polarized isolation levels over 45 dB and insertion loss lower than 0.15 dB over the entire bandwidth. The measured results are in good agreement with the simulations. [ABSTRACT FROM AUTHOR]

Abstract The Northern Wheatear (Oenanthe oenanthe, including the nominate and the two subspecies O. o. leucorhoa and O. o. libanotica) and the Seebohm’s Wheatear (Oenanthe seebohmi) are today regarded as two distinct species. Before, all four taxa were regarded as four subspecies of the Northern Wheatear. Their classification has exclusively been based on ecological and morphological traits, while their molecular characterization is still missing. With this study, we used next-generation sequencing to assemble 117 complete mitochondrial genomes covering O. o. oenanthe, O. o. leucorhoa and O. seebohmi. We compared the resolution power of each individual mitochondrial marker and concatenated marker sets to reconstruct the phylogeny and estimate speciation times of three taxa. Moreover, we tried to identify the origin of migratory wheatears caught on Helgoland (Germany) and on Crete (Greece). Mitogenome analysis revealed two different ancient lineages that separated around 400,000 years ago. Both lineages consisted of a mix of subspecies and species. The phylogenetic trees, as well as haplotype networks are incongruent with the present morphology-based classification. Mitogenome could not distinguish these presumed species. The genetic panmixia among present populations and taxa might be the consequence of mitochondrial introgression between ancient wheatear populations.

With the development of modern cities, metro are playing an increasingly important role in urban traffic. A biochemical terrorist attack in a metro station can cause many casualties. Therefore, more attention should be paid to metro emergency management. This paper presents a guidance scheme based on an improved empirical formula to optimize emergency evacuation. Additionally, the guidance evacuation model combined the social force model with pedestrian characteristics to study the influence of pedestrian behaviors on guidance evacuation. The experiment results show the following: (1) A guidance scheme based on an improved empirical formula can significantly reduce the casualties and improve the efficiency of evacuation; (2) The guidance evacuation model can be used to find the reasonable guidance locations and the combination of guides. (3) Pedestrian characteristics must be taken into account in the research of the guidance evacuation. Analyzing the behavioral characteristics of pedestrian can provide improvement measures for guidance evacuation. This paper focuses on the simulation experiments of emergency evacuation in metro station, which can provide practical references for developing an efficient and safe emergency evacuation scheme.

Genetic diversity is one of the three dimensions of biodiversity and fundamental to various life forms on the Earth. Understanding the distribution pattern of genetic diversity and its driving forces has been an important topic in ecology, biogeography and conservation biology since the last decade. We investigated the genetic diversity pattern of passerine birds in the Mountains of Southwest China, a global biodiversity hotspot with the highest species richness of birds in the entire Eurasia, and explored the influencing forces of environmental variables on genetic diversity. We compiled 1189 Cytochrome b sequences of 27 passerine species from 152 geographic sites, covering the range of Mountains of Southwest China and its adjoining areas. We generated genetic diversity distribution maps using a grid-cell method based on nucleotide diversity and haplotype diversity indices. We further analyzed the variation pattern of the two indices along latitudinal, longitudinal, and elevational gradients. The correlations between the two indices and environmental variables were also evaluated. The nucleotide diversity hotspots were mostly located in the southern Hengduan Mountains, while for haplotype diversity, three hotspots were detected: the southeast edge of the Qinghai-Tibetan Plateau, the southern Hengduan Mountains and the Qinling Mountains. There was no monotonic increasing or decreasing pattern in nucleotide diversity or haplotype diversity along latitudinal, longitudinal or elevational gradients except for altitudinal range. Correlation and model selection analyses detected multiple environmental variables in driving genetic diversity patterns, including temperature, precipitation, vegetation, human influence, longitude and altitude range. Similar to the pattern of species richness, the nucleotide diversity pattern of passerine birds in the Mountains of Southwest China presents a decreasing trend from southwest to northeast, while the haplotype diversity pattern is more likely decreased from west to east. Our results indicate that the distribution pattern of genetic diversity may be derived from the complex topography and diverse microclimates in the Mountains of Southwest China.

Background and Aim: To evaluate the clinical effect of ultrasound (US)-guided percutaneous thermal ablation of hepatic focal nodular hyperplasia (FNH).Methods: A retrospective analysis of the clinical data of patients undergoing US-guided percutaneous thermal ablation of FNH from November 2008 to August 2021 at five medical centers in China was conducted.Results: A total of 53 patients were included (26 males and 27 females). The mean age was 35.1 ± 10.8 years. Sixty-five lesions (46 solitary cases and 7 cases with multiple lesions) were included, 70.8% (46/65) of which were located in the right liver lobe. The mean tumor length was 2.9 ± 1.5 cm. All patients successfully completed the ablation treatment. Immediate postoperative imaging showed that the primary technical success rate was 94.3% (50/53). Two patients underwent ablation 3 and 6 months after the primary ablation, and the secondary technical success rate was 100% (2/2). The incidence of complications was 3.8% (2/53). Imaging follow-up was conducted regularly after ablation, and no residual lesion enlargement or tumor recurrence was observed during the follow-up period. The technique efficacy rate was 98.1% (52/53).Conclusion: US-guided percutaneous thermal ablation is a safe and effective treatment for FNH of the liver.

The research on the structural response of explosive vessel is an important basis for the design of explosive vessels. Double-layer cylinder structures are widely used in the design of various explosive vessels. This paper studied the deformation of a steel cylindrical shell under internal explosion and proposes a new method for measuring shell deformation by PDV (photonic Doppler velocimetry). We carried out many spherical explosive experiments and obtained useful results that show displacement of the double-layer cylinders and the explosion time. The above process is a simulated LS-DYNA with a finite element numerical simulation. The vibration period of the outer cylindrical shell and the time for reflection of the stress wave in the outer cylindrical shell were obtained by numerical simulation and PDV measurement, respectively. The results of both can be verified against each other. Through the above research, the structural response of the multilayer cylinders can be obtained, which can provide further help with research of the structural design of multilayer cylinders.

Summary Corynebacterium glutamicum is an important industrial microorganism, but the availability of tools for its genetic modification has lagged compared to other model microorganisms such as Escherichia coli. Despite great progress in CRISPR‐based technologies, the most feasible genome editing method in C. glutamicum is suicide plasmid‐mediated, the editing efficiency of which is low due to high false‐positive rates of sacB counter selection, and the requirement for tedious two‐round selection and verification of rare double‐cross‐over events. In this study, an rpsL mutant conferring streptomycin resistance was harnessed for counter selection, significantly increasing the positive selection rate. More importantly, with the aid of high selection efficiencies through the use of antibiotics, namely kanamycin and streptomycin, the two‐step verification strategy can be simplified to just one‐step verification of the final edited strain. As proof of concept, a 2.5‐kb DNA fragment comprising aroGfbrpheAfbr expressing cassettes was integrated into the genome of C. glutamicum, with an efficiency of 20% out of the theoretical 50%. The resulting strain produced 110 mg l−1 l‐tyrosine in shake‐flask fermentation. This updated suicide plasmid‐mediated genome editing system will greatly facilitate genetic manipulations including single nucleotide mutation, gene deletion and gene insertion in C. glutamicum and can be easily applied to other microbes.

Background: The supplementation of betaine, an osmoprotective compatible solute, in the cultivation media has been widely used to protect bacterial cells. To explore the effects of betaine addition on industrial fermentation, Escherichia coli THRD, an l-threonine producer, was used to examine the production of l-threonine with betaine supplementation and the underlying mechanism through which betaine functions was investigated. Results: Betaine supplementation in the medium of E. coli THRD significantly improved l-threonine fermentation parameters. The transcription of zwf and corresponding enzyme activity of glucose-6-phosphate dehydrogenase were significantly promoted by betaine addition, which contributed to an enhanced expression of zwf that provided more nicotinamide adenine dinucleotide phosphate (NADPH) for l-threonine synthesis. In addition, as a result of the betaine addition, the betaine-stimulated expression of enhanced green fluorescent protein (eGFP) under the zwf promoter within a plasmid-based cassette proved to be a transcription-level response of zwf. Finally, the promoter of the phosphoenolpyruvate carboxylase gene ppc in THRD was replaced with that of zwf, while l-threonine fermentation of the new strain was promoted by betaine addition. Conclusions: We reveal a novel mode of betaine that facilitates the microbial production of useful compounds. Betaine supplementation upregulates the expression of zwf and increases the NADPH synthesis, which may be beneficial for the cell growth and thereby promote the production of l-threonine. This finding might be useful for the production of NADPH-dependent amino acids and derivatives in E. coli THRD or other E. coli strains.How to cite: Li Y, Zhang D, Cai N, et al. Betaine supplementation improved l-threonine fermentation of Escherichia coli THRD by upregulating zwf (glucose-6-phosphate dehydrogenase) expression. Electron J Biotechnol 2019;39. https://doi.org/10.1016/j.ejbt.2019.03.004. Keywords: Betaine, Escherichia coli THRD, Escherichia coli, Industrial fermentation, l-Threonine producer, l-Threonine, NADPH, Osmoprotective compatible solute, Pentose phosphate pathway, zwf

In this paper, a single-vehicle static partial repositioning problem (SPRP) is investigated, which distinguishes the user dissatisfaction generated by different stations. The overall objective of the SPRP is to minimize the weighted sum of the total operational time and the total absolute deviation from the target number of bikes at all stations. An iterated local search is developed to solve this problem. A novel loading and unloading quantity adjustment operator is proposed to further improve the quality of the solution. Experiments are conducted on a set of instances from 30 to 300 stations to demonstrate the effectiveness of the proposed customized solution algorithm as well as the adjustment operator. Using a small example, this paper also reveals that the unit penalty cost has an effect on the repositioning strategies.

Abstract Background Dyschromatosis symmetrica hereditaria (DSH;OMIM: #127400) is a rare autosomal dominant skin disease of hyperpigmented and hypopigmented macules on the dorsal aspects of the feet and hands. The adenosine deaminase RNA‐Specific (ADAR;OMIM: *146920) gene was identified as causing DSH. Although more than 200 mutations are reported, no research has included the pedigrees of ethnic minorities in China. To investigate clinical features and genetic factors among multi‐ethnic families, seven multi‐ethnic pedigrees with DSH were collected for analysis of hereditary characteristics and ADAR mutations. Methods All 15 exons and exon–intron sequences of the ADAR gene were amplified and Sanger sequenced from 25 patients and 36 normal controls from seven multi‐ethnic DSH families with 100 healthy normal controls. Seven mutations were analyzed by Polyphen 2, SIFT and Provean. All mutations in ADAR with DSH were reviewed and genetic and clinical features were summarized for analysis. The ADEAMc domain may be a hot spot of ADAR mutations among patients with DSH. Results Seven novel mutations were identified in seven multi‐ethnic pedigrees: c.497delA(p.Arg105fs), c.3352C>T(p.Gln1058*) and c.3722delT(p.Ser1181fs) were found in three Uygur families with DSH; c.1330A>G(p.Val332Met) and c.2702A>T(p.His841Leu) were found in two Kazakh pedigrees and c.1176G>A(p.Lys326Glu) and c.2861G>A(p.Arg892His) in two Hui pedigrees. We summarized 203 different mutations of ADAR from people with DSH. Conclusions Seven novel mutations were identified in seven multi‐ethnic families with DSH. Our study expands the genetic spectrum of ADAR mutations in DSH.

This study investigates a multimodal green logistics network design problem of urban agglomeration with stochastic demand, in which different logistics authorities among the different cities jointly optimize the logistics node configurations and uniform carbon taxes over logistics transport modes to maximize the total social welfare of urban agglomeration and consider logistics users’ choice behaviors. The users’ choice behaviors are captured by a logit-based stochastic equilibrium model. To describe the game behaviors of logistics authorities in urban agglomeration, the problem is formulated as two nonlinear bilevel programming models, namely, independent and centralized decision models. Next, a quantum-behaved particle swarm optimization (QPSO) embedded with a Method of Successive Averages (MSA) is presented to solve the proposed models. Simulation results show that to achieve the overall optimization layout of the green logistics network in urban agglomeration the logistics authorities should adopt centralized decisions, construct a multimode logistics network, and make a reasonable carbon tax.

The Hopkinson pressure bar is widely used to measure the reflected pressure of blast waves over a short distance. However, dispersion effects will occur when the elastic stress waves propagate in the pressure bar due to lateral inertia, and there will be errors between the signals obtained from the sensors and the actual loading. For the free surface velocity measured in our system, we developed a local phase-amplitude joint correction method to convert the measured velocity into the average reflected pressure of a shock wave at the impact end of the bar, considering factors such as propagation modes of the elastic wave, the frequency components’ time of arrival, velocity variation over the bar axis, and the stress–velocity relationship. Firstly, the Pochhammer–Chree frequency equation is calculated numerically, and the first to fourth orders of phase velocity, group velocity, normalized frequency, and propagation time curves of elastic wave propagation in 35CrMnSiA steel are obtained. Secondly, the phase and amplitude correction formulas for calculating average reflected pressure from center velocity are derived based on the propagation mode of the axial elastic wave in the pressure bar by analyzing the time-frequency combined spectrum obtained by short-time Fourier transform. Thirdly, a local phase-amplitude joint correction algorithm based on propagation mode is proposed in detail. The experimental tests and data analyses are carried out for eight sets of pressure bar. The results show that this method can identify the propagation mode of elastic waves in the bar intuitively and clearly. The first three orders of propagation modes are stimulated in the bar 04, while only the first order of propagation is stimulated in the other eight bars. The local phase-amplitude joint correction algorithm can avoid correcting the component of the non-axial elastic wave. The rising edge of the average stress curve on the impact surface of bar 01 and bar 04 is corrected from 4.13 μs and 4.09 μs to 2.70 μs, respectively.

Polar motion (PM) has a close relation to the Earth’s structure and composition, seasonal changes of the atmosphere and oceans, storage of waters, etc. As one of the four major space geodetic techniques, doppler orbitography and radiopositioning integrated by satellite (DORIS) is a mature technique that can monitor PM through precise ground station positioning. There are few articles that have analyzed the PM series derived by the DORIS solution in detail. The aim of this research was to assess the PM time-series based on the DORIS solution, to better capture the time-series. In this paper, Fourier fast transform (FFT) and singular spectrum analysis (SSA) were applied to analyze the 25 years of PM time-series solved by DORIS observation from January 1993 to January 2018, then accurately separate the trend terms and periodic signals, and finally precisely reconstruct the main components. To evaluate the PM time-series derived from DORIS, they were compared with those obtained from EOP 14 C04 (IAU2000). The results showed that the RMSs of the differences in PM between them were 1.594 mas and 1.465 mas in the X and Y directions, respectively. Spectrum analysis using FFT showed that the period of annual wobble was 0.998 years and that of the Chandler wobble was 1.181 years. During the SSA process, after singular value decomposition (SVD), the time-series was reconstructed using the eigenvalues and corresponding eigenvectors, and the results indicated that the trend term, annual wobble, and Chandler wobble components were accurately decomposed and reconstructed, and the component reconstruction results had a precision of 3.858 and 2.387 mas in the X and Y directions, respectively. In addition, the tests also gave reasonable explanations of the phenomena of peaks of differences between the PM parameters derived from DORIS and EOP 14 C04, trend terms, the Chandler wobble, and other signals detected by the SSA and FFT. This research will help the assessment and explanation of PM time-series and will offer a good method for the prediction of pole shifts.

This paper proposes a model to address the design problem of a regional logistics network. In the proposed model, the decision variables include the location and size of logistics parks. The interaction between the logistics authority and logistics users as well as the effects of economies of scale and CO2 emission taxes on the logistics network design are explicitly considered. The proposed model is formulated as a bi-level formulation, in which the upper level aims to maximize total social welfare of the system by determining the optimal location and size of logistics parks with CO2 emission taxes consideration, whereas the lower level describes the logistics users’ choices for service routes. A heuristic solution algorithm is presented to solve the proposed model, and a numerical example is given to illustrate the applications of the proposed model and solution algorithm. The findings show that the optimal location and size of logistics parks depend on the realized logistics demand and the level of the economies of scale. The CO2 emission taxation can help to improve the total social welfare of the system and drive the logistics users to choose greener transportation modes. First published online 28 January 2015

Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO2 emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO2 emissions and the optimal departure time saves on fuel consumption and reduces CO2 emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions.

This study develops an optimization model to integrate facility location and inventory control for a three-level distribution network consisting of a supplier, multiple distribution centers (DCs), and multiple retailers. The integrated model addressed in this study simultaneously determines three types of decisions: (1) facility location (optimal number, location, and size of DCs); (2) allocation (assignment of suppliers to located DCs and retailers to located DCs, and corresponding optimal transport mode choices); and (3) inventory control decisions on order quantities, reorder points, and amount of safety stock at each retailer and opened DC. A mixed-integer programming model is presented, which considers the carbon emission taxes, multiple transport modes, stochastic demand, and replenishment lead time. The goal is to minimize the total cost, which covers the fixed costs of logistics facilities, inventory, transportation, and CO2 emission tax charges. The aforementioned optimal model was solved using commercial software LINGO 11. A numerical example is provided to illustrate the applications of the proposed model. The findings show that carbon emission taxes can significantly affect the supply chain structure, inventory level, and carbon emission reduction levels. The delay rate directly affects the replenishment decision of a retailer.

This study considers a design problem in the supply chain network of an assembly manufacturing enterprise with economies of scale and environmental concerns. The study aims to obtain a rational tradeoff between environmental influence and total cost. A mixed-integer nonlinear programming model is developed to determine the optimal location and size of regional distribution centers (RDCs) and the investment of environmental facilities considering the effects of economies of scale and CO2 emission taxes. Numerical examples are provided to illustrate the applications of the proposed model. Moreover, comparative analysis of the related key parameters is conducted (i.e., carbon emission tax, logistics demand of customers, and economies of scale of RDC), to explore the corresponding effects on the network design of a green supply chain. Moreover, the proposed model is applied in an actual case—network design of a supply chain of an electric meter company in China. Findings show that (i) the optimal location of RDCs is affected by the demand of customers and the level of economies of scale and that (ii) the introduction of CO2 emission taxes will change the structure of a supply chain network, which will decrease CO2 emissions per unit shipment.

The design of a multimodal logistics service network with customer service time windows and environmental costs is an important and challenging issue. Accordingly, this work established a model to minimize the total cost of multimodal logistics service network design with time windows and environmental concerns. The proposed model incorporates CO2 emission costs to determine the optimal transportation mode combinations and investment selections for transfer nodes, which consider transport cost, transport time, carbon emission, and logistics service time window constraints. Furthermore, genetic and heuristic algorithms are proposed to set up the abovementioned optimal model. A numerical example is provided to validate the model and the abovementioned two algorithms. Then, comparisons of the performance of the two algorithms are provided. Finally, this work investigates the effects of the logistics service time windows and CO2 emission taxes on the optimal solution. Several important management insights are obtained.

This paper uses a real options approach to address optimal timing and size of a logistics park investment with logistics demand volatility. Two important problems are examined: when should an investment be introduced, and what size should it be? A real option model is proposed to explicitly incorporate the effect of government subsidies on logistics park investment. Logistic demand that triggers the threshold for investment in a logistics park project is explored analytically. Comparative static analyses of logistics park investment are also carried out. Our analytical results show that (1) investors will select smaller sized logistics parks and prepone the investment if government subsidies are considered; (2) the real option will postpone the optimal investment timing of logistics parks compared with net present value approach; and (3) logistic demands can significantly affect the optimal investment size and timing of logistics park investment.

Climate change is an extremely serious international problem, which is concerned by all the communities in the world. As a major sector of energy consumption and the main source of carbon emissions, it is necessary for the Chinese transportation sector to take on a low carbon development path in order to alleviate the energy consumption and environment pollution and take a positive role in these fields. Under such environment, the supporting and evaluation systems of low carbon transport from four aspects, namely, the efficiency, industry, innovation, guide and society, of low carbon are established in this study. An empirical example from Changsha City, Hunan Province in China is provided as numerical example.

This article proposes a new model to address the design problem of a sustainable regional logistics network with uncertainty in future logistics demand. In the proposed model, the future logistics demand is assumed to be a random variable with a given probability distribution. A set of chance constraints with regard to logistics service capacity and environmental impacts is incorporated to consider the sustainability of logistics network design. The proposed model is formulated as a two-stage robust optimization problem. The first-stage problem before the realization of future logistics demand aims to minimize a risk-averse objective by determining the optimal location and size of logistics parks with CO 2 emission taxes consideration. The second stage after the uncertain logistics demand has been determined is a scenario-based stochastic logistics service route choices equilibrium problem. A heuristic solution algorithm, which is a combination of penalty function method, genetic algorithm, and Gauss–Seidel decomposition approach, is developed to solve the proposed model. An illustrative example is given to show the application of the proposed model and solution algorithm. The findings show that total social welfare of the logistics system depends very much on the level of uncertainty in future logistics demand, capital budget for logistics parks, and confidence levels of the chance constraints.

This paper proposes a new model of simultaneous optimization of three-level logistics decisions, for logistics authorities, logistics operators, and logistics users, for regional logistics network with environmental impact consideration. The proposed model addresses the interaction among the three logistics players in a complete competitive logistics service market with CO2 emission charges. We also explicitly incorporate the impacts of the scale economics of the logistics park and the logistics users’ demand elasticity into the model. The logistics authorities aim to maximize the total social welfare of the system, considering the demand of green logistics development by two different methods: optimal location of logistics nodes and charging a CO2 emission tax. Logistics operators are assumed to compete with logistics service fare and frequency, while logistics users minimize their own perceived logistics disutility given logistics operators’ service fare and frequency. A heuristic algorithm based on the multinomial logit model is presented for the three-level decision model, and a numerical example is given to illustrate the above optimal model and its algorithm. The proposed model provides a useful tool for modeling competitive logistics services and evaluating logistics policies at the strategic level.