Simulation and optimisation of magnetic and experimental study of magnetic field coupling constructed wetland.

This study developed a novel constructed wetland (CW) coupled with a magnetic field for treating domestic wastewater, and the magnetic field distribution was solved and optimised by the finite element method. Herein, we investigated the effects of optimising magnetic field optimisation and studied its impact on CW treatment performance and the responses of a microbial community. The optimisation results showed that the average magnetic field strength of the CW unit increases from 3 to 8 mT, and the proportion of areas with magnetic field strength greater than 5 mT also increases from 30% to 74%. The water quality analysis results showed that the removal of chemical oxygen demand (COD) and NH4+-N (p < 0.01) was significantly increased by the magnetic field (average 3 mT), increasing by 12.2% and 8.49%, respectively. Moreover, the removal of COD and NH4+-N (p < 0.01) was more significantly increased by M-VFCW(O) (average 8 mT), increasing by 15.58% and 49.1%, respectively. The magnetic field application shifted significantly the abundance of dominant bacteria in CWs. Relative abundance of dominant bacteria such as Proteobacteria (63.3%), Firmicutes (4.72%) and Actinobacteria (2.11%) that played an important role in organics removal and nitrification and denitrification-related bacteria such as Nitrospirae (1.48%) and Planctomycetes (9.58%) significantly promoted in M-VFCW(O). These results suggest that introducing a magnetic field into CWs may improve organics and nitrogen removal via the biological process, and the optimisation of the magnetic field was significant in enhancing the performance of VFCWs.

The Response of Rocky Desertification to the Development of Road Networks in Karst Ecologically Fragile Areas.

Frequent cross-regional communication makes road networks increasingly dense and has generated prominent human interference, thus resulting in the destruction of the landscape's integrity and leading to changes in the functional processes of the habitat. In order to discuss the impacts of intense human activity brought by the road networks on the rocky desertification landscape and habitat quality in karst ecologically fragile areas, taking the road networks as the humans activity intensity factor, a quantitative analysis was conducted to analyze the impacts of road networks on the spatial evolution of the rocky desertification landscape and changes in regional habitat quality characteristics under different development modes in the study area based on a landscape pattern gradient method, spatial analysis, and INVEST model. The results showed that: (1) in the study area, due to the destruction of landscape integrity caused by the development of the road networks over the past 17 years, the landscape pattern of rocky desertification tended to be fragmented and complex, first showing an inclination for rapid fragmentation and then gradual recovery later. (2) The land-use intensity and degree of rocky desertification in the industrial areas and in the tourist areas of the study area have increased to varying degrees over the past 17 years, as is seen mainly via the expansion of construction land, cultivated land enclaves in the urban expansion areas, and new development areas. (3) Unders different regional models, the fragmentation of the rocky desertification landscape in the industrial areas was higher than that in the tourist areas, resulting in a significantly lower habitat quality and obvious degrees of degradation. The research findings provide the basis for further deepening our understanding how human activity intensity affects the evolution of the regional landscape, including the development of rocky desertification, the supply of services, and supporting habitat conservation in karst ecologically fragile areas.

Residual Life Prediction of XLPE Distribution Cables Based on Time-Temperature Superposition Principle by Non-Destructive BIS Measuring on Site.

Crosslinked polyethylene (XLPE) distribution cables are prone to segmented thermal aging after long-term operation owing to the large spatial spans and complex operating environments, and accurate residual life prediction of each aging cable segment could provide a theoretical basis and reference for performance monitoring, maintenance and the replacement of cables. Existing studies mainly focus on the residual life prediction methods for uniform aging cables, which are not suitable for segmented-aging cables. In this paper, a residual life prediction method for segmented-aging XLPE distribution cables based on the time-temperature superposition principle (TTSP) by non-destructive BIS measuring on site was proposed. Firstly, the applicability of the TTSP in the transformation of the changing process of elongation at break (EAB) of XLPE at different thermal aging temperatures was verified based on the Arrhenius equation. Secondly, to better simulate the thermal aging process under working conditions, XLPE cables were subjected to accelerated external stress aging at 140 °C for different aging times, and the corresponding changing process of EAB along with aging time was further measured. The relationship between the EAB of XLPE cables and aging time was well fitted by an equation, which could be used as a reference curve to predict the thermal aging trends and residual life of service-aged XLPE cables. After that, a calculation method for the transformation of the changing process of EAB of XLPE at different thermal aging temperatures was proposed, in which the corresponding multiplicative shift factor could be obtained based on the TTSP instead of the Arrhenius equation extrapolation. Moreover, the availability of the above calculation method was further proved by accelerated thermal aging experiments at 154 °C; the results show that the prediction error for the cable's EAB is no more than 3.15% and the prediction error for residual life is within 10% in this case. Finally, the realization of non-destructive residual life prediction combined with BIS measuring on site was explained briefly.

Ecological Quality Evolution and Its Driving Factors in Yunnan Karst Rocky Desertification Areas.

Rocky desertification is a key element affecting regional ecological quality. Rocky desertification in Southwest China directly affects the ecological security of the Yangtze River and Pearl River basins and also restricts regional economic and social development. In order to clarify the evolution laws and key influencing factors of ecological quality in Yunnan karst rocky desertification areas, a quantitative analysis based on the remote sensing-based ecological index (RSEI) model was conducted to explore the overall evolution characteristics and change laws of ecological quality in Yunnan karst rocky desertification areas in the past 30 years. The correlation between RSEI, rock outcrop rate (Fr), and driving factors was determined by redundancy analysis. The results showed the following: (1) RSEI in Yunnan karst rocky desertification areas generally showed a decreasing trend, with a fluctuation in the mid-term, followed by a tendency to recover. It fell into three stages: decline, trough, and recovery, with fitting coefficients of -0.121, -0.057, and 0.157, respectively. In contrast, Fr showed an opposite tendency, illustrating the inverse relationship between RSEI and Fr, and the rate of sequential succession was much faster than that of the reverse succession under human measures of intervention. (2) The mean value of RSEI of Yunnan karst rocky desertification areas was generally lower than that of the total Yunnan Province land areas and Yunnan non-karst rocky desertification areas, but the mean value of Fr was generally more than that of both the above-mentioned areas. In addition, the RSEI and Fr of Yunnan karst rocky desertification areas both showed lower stability values than those of both the above-mentioned areas. This generally suggested a low ecological quality and a high degree of desertification under a low stability in Yunnan karst rocky desertification areas. (3) The correlation of RSEI and Fr with driving factors followed the order of topographic factors, soil factors > water factors > anthropogenic factors. Anthropogenic factors were the driving force changing the state of rocky desertification, geological factors such as topography and soil to a larger extent determined the original macroscopic ecological relationship of rocky desertification, and water factors lay between the above two. The findings of this research will provide theoretical support and a basis for the improvement of ecological quality and comprehensive control of karst rocky desertification in Yunnan Province.

High-Voltage FDS of Thermally Aged XLPE Cable and Its Correlation with Physicochemical Properties.

This paper aims to investigate the influence of thermal aging on a crosslinked polyethylene (XLPE) cable, and the relationships between the macroscopical high-voltage dielectric and the microscopical physicochemical properties are also elucidated. To better simulate thermal aging under working condition, the medium-voltage-level cable is subjected to accelerated inner thermal aging for different aging times. Then, high-voltage frequency domain spectroscopy (FDS) (cable sample) and analyses of microscopic physical and chemical properties (sampling from the cable), including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and elongation at the break (EAB), are conducted at different cable aging stages. The dielectric test results show that after a certain aging time, the high-voltage FDS curves of the cable have layered characteristics, and this phenomenon is more obvious as the aging degree increases. Moreover, the slope and the integral of the high-voltage FDS curves rise with aging time. The mechanism is deduced by the physicochemical results that thermo-oxidative aging results in increasing polar groups and dislocation defects in the crystal region, which leads to the above phenomenon. On the one hand, the appearance of polar groups increases the density of the dipole. On the other hand, the destruction of the crystal region increases the probability and amplitude of dipole reversal. In addition, the breaking of molecular bonds and the increase in the amorphous phase also reduce the rigidity of the XLPE molecular main chain. The above factors lead to obvious delamination and larger dielectric parameters of the thermally aged cable. Finally, according to the experimental results, an on-site diagnosis method of cable insulation thermal aging based on high-voltage FDS is discussed.

Airport noise disturbs foraging behavior of Japanese pipistrelle bats.

The expansion of anthropogenic noise poses an emerging threat to the survival and reproductive success of various organisms. Previous investigations have focused on the detrimental effects of anthropogenic noise on the foraging behavior in some terrestrial and aquatic animals. Nevertheless, the role of airport noise in impairing foraging activities of most wild animals has been neglected. Here, we aimed to assess whether foraging behavior in free-living Japanese pipistrelle bats (Pipistrellus abramus) can be disturbed by airport noise. We used audio recording to monitor foraging activities of bats at 11 sites around the runway of a municipal airport. We quantified noise level and spectra, aircraft activity, habitat type, nightly temperature, wind speed, and moon phase for each site. The analysis revealed that noise level and aircraft activity were significant negative predictors for the number of bat passes and feeding buzzes around the runway, even after controlling for the effects of other environmental factors. There was no marked spectral overlap between bat echolocation pulses and airport noise in the presence and absence of low-flying aircraft. The spectro-temporal parameters of echolocation vocalizations emitted by bats were dependent on noise level, aircraft activity, and habitat type. These results provide correlative evidence that airport noise can reduce foraging activities of wild pipistrelle bats. Our findings add to the current knowledge of adverse impacts of airport noise on foraging bats in artificial ecosystems and provide a basis for further research on the mechanisms behind noise pollution near airports.

[Reflections on and Preliminary Practice of Pharmaceutical Curriculum Structure Reform under the Guidance of Coordinated Development Concept].

The structure of pharmaceutical higher education in China needs to be adjusted under the guidance of Xi Jinping's new development philosophy, especially the concept of coordinated development, in order to meet the demands of the campaign to construct new medical education and to develop in coordination with the pharmaceutical industry. Based on the concept of coordinated development, we summarized herein the relationship between pharmaceutical higher education, pharmaceutical research and the pharmaceutical industry, analyzed the adaptability of pharmaceutical higher education and the pharmaceutical industry, and put forward suggestions for and implemented initially the reform of the pharmaceutical curriculum structure under the guidance of the concept of coordinated development. We hope this paper will, under the new circumstances, provide useful reference for the ongoing education reform of the curricular structure of pharmaceutical higher education and pharmaceutical research coordinated along with the development of the pharmaceutical industry.

Function of miR-24 and miR-27 in Pediatric Patients With Idiopathic Nephrotic Syndrome.

Purpose: We investigated the pathogenesis of idiopathic nephrotic syndrome (INS) by measuring the effects two specific miRNAs on Th2 cells in children with this disease. Methods: After informed consent, we enrolled 20 children with active INS before steroid initiation, 20 children with INS in remission after steroid therapy, and 20 age-matched healthy controls. Flow cytometry was used to measure the levels of Th2 cells and a cytometric bead array was used to measure the levels of IgE, interleukin (IL)-4, and IL-13. RT-PCR was used to measure the levels of miR-24 and miR-27 in CD4+TCD25- cells. PBMCs were isolated using Ficoll density gradient centrifugation, and transfected with different mimic or inhibitor miRNAs. RT-PCR was used to measure the expression of different RNAs, and flow cytometry was used to determine the percentage of Th2 cells. Results: Relative to healthy controls, children with active INS had higher percentages of Th2 cells (P < 0.05), but there was no significant difference in controls and children in remission. The plasma levels of IgE, IL-4, and IL-13 were significantly increased in children with active INS (P < 0.05). There were lower levels of miR-24 and miR-27 in children with active non-atopic INS (P < 0.05). Transfection experiments indicated that upregulation of each miRNA decreased the percentage of Th2 cells and the level of IL-4 (P < 0.05), and down-regulation of each miRNA had the opposite effects (P < 0.05). Conclusion: Children with active INS, with or without atopy, had higher levels of IgE, possibly related to their higher levels of IL-13 and IL-4 due to a drift toward Th2 cells. miR-24 and miR-27 suppressed the expression of Th2 cells and have a critical function regulating Th2 cell expression in INS.

Phenomic Analysis of Chronic Granulomatous Disease Reveals More Severe Integumentary Infections in X-Linked Compared With Autosomal Recessive Chronic Granulomatous Disease.

Background: Chronic granulomatous disease (CGD) is an inborn error of immunity (IEI), characterised by recurrent bacterial and fungal infections. It is inherited either in an X-linked (XL) or autosomal recessive (AR) mode. Phenome refers to the entire set of phenotypes expressed, and its study allows us to generate new knowledge of the disease. The objective of the study is to reveal the phenomic differences between XL and AR-CGD by using Human Phenotype Ontology (HPO) terms. Methods: We collected data on 117 patients with genetically diagnosed CGD from Asia and Africa referred to the Asian Primary Immunodeficiency Network (APID network). Only 90 patients with sufficient clinical information were included for phenomic analysis. We used HPO terms to describe all phenotypes manifested in the patients. Results: XL-CGD patients had a lower age of onset, referral, clinical diagnosis, and genetic diagnosis compared with AR-CGD patients. The integument and central nervous system were more frequently affected in XL-CGD patients. Regarding HPO terms, perianal abscess, cutaneous abscess, and elevated hepatic transaminase were correlated with XL-CGD. A higher percentage of XL-CGD patients presented with BCGitis/BCGosis as their first manifestation. Among our CGD patients, lung was the most frequently infected organ, with gastrointestinal system and skin ranking second and third, respectively. Aspergillus species, Mycobacterium bovis, and Mycobacteirum tuberculosis were the most frequent pathogens to be found. Conclusion: Phenomic analysis confirmed that XL-CGD patients have more recurrent and aggressive infections compared with AR-CGD patients. Various phenotypic differences listed out can be used as clinical handles to distinguish XL or AR-CGD based on clinical features.

Up-regulation of miR-27a promotes monocyte-mediated inflammatory responses in Kawasaki disease by inhibiting function of B10 cells.

Kawasaki disease (KD) is an acute systemic vasculitis and activation of monocytes plays a central role in the pathogenesis of it. B10 cells, a B cell subset with negative regulatory properties, are functionally identified by their ability to express cytoplasmic IL-10 after ex vivo stimulation. Here, we aimed to explore the functional role of B10 cells during monocyte-mediated inflammatory responses in KD, as well as elucidate the underlying microRNA (miRNA)-mediated regulatory mechanisms. Expression of IL-10 by each group of B cells (total B cells, transitional B cells, naïve B cells, and memory B cells) and inhibition of monocyte-derived TNF-α by activated B cells were measured by flow cytometry. Expression of miRNAs (miR-21-3p, miR-98-5p/3p, miR-27a-3p, let7b-5p, and miR-1423p/5p) that affect IL-10 levels in B cells was quantitated by real-time PCR. The relationship between IL-10 and these miRNAs was examined by multivariate analysis. MiR-mediated RNA interference in B cells was performed to investigate the role of miR-27a on expression of IL-10. The results showed expression of cytoplasmic IL-10 in B cell subsets from patients with KD was down-regulated. The inhibitory effect of B10 cells on production of TNF-α by monocytes from patients with KD was also compromised. The miR-27a-3p expression was markedly up-regulated during the acute phrase of KD, and it promoted monocyte-mediated TNF-α release by negatively regulating expression of cytoplasmic IL-10 within B cells in vitro. The data suggest up-regulated miR-27a in B cells from patients with KD may promote monocyte-mediated inflammatory responses by inhibiting the regulatory function of B10 cells.

Research on Creeping Flashover Characteristics of Nanofluid-Impregnated Pressboard Modified Based on Fe3O4 Nanoparticles under Lightning Impulse Voltages.

Creeping flashover of mineral-oil-impregnated pressboard under impulse stress is a common insulating failure in oil-immersed transformers, arousing increasing attention. Recent studies have shown that the breakdown strength of transformer oil under positive lightning impulse voltage can be significantly improved through nanoparticles-based modification, and Fe3O4 has shown the best improvement in breakdown strength compared to other nanoparticles that have been used. This paper presents the creeping flashover characteristics of pure oil-impregnated pressboard (OIP) and nanofluid-impregnated pressboard (NIP) based on Fe3O4 nanoparticles under positive and negative lightning impulse voltages, respectively. It was found that NIP possessed higher resistance to creeping flashover than OIP. The relative permittivities of oil and oil-impregnated pressboard before and after nanoparticles-based modification were measured, and the results revealed that the addition of nanoparticles led to a better match in relative permittivity between oil and oil-impregnated pressboard, and a more uniform electric field distribution. Furthermore, the shallow trap density in NIP was obviously increased compared to that of OIP through the thermally stimulated depolarization current (TSDC), which promoted the dissipation of surface charges and weakened the distortion of the electric field. Therefore, the creeping flashover characteristics of oil-impregnated pressboard were greatly improved with Fe3O4 nanoparticles.

Polarization and Trap Characteristics Modification of Oil-Impregnated Paper Insulation by TiO2 Nanoparticles.

Polarization and traps determine the electrical property of oil-paper insulation, but most attention has been paid to the modification of insulating oil with nanoparticles, so there are is little research about oil-impregnated paper, and the origin for performance variation is not understood yet. In this paper, spherical nanoscale titanium dioxide was prepared by the hydrolysis method and nanofluid-impregnated paper (NP) was fabricated through oil-impregnation. The frequency domain spectrum was measured for polarization analysis, and both thermally stimulated depolarization current (TSDC) and isothermal surface potential decay (ISPD) methods were used to reveal trap parameters. Results show that NP's low frequency permittivity is much larger, and another peak appears in the spectrum even though the content of nanoparticles is very low. With the addition of TiO2 nanoparticles, TSDC's amplitude and peak temperature increase, and the trap energy becomes shallower. TiO2 nanoparticles' strong polarization and high activation energy contribute to NP's larger interface polarization intensity and activation energy. Furthermore, because of oxygen vacancies, TiO2 nanoparticles offer a transfer site for holes and electrons to escape from deep traps; thus, the trap energy is greatly reduced.

Targeted next-generation sequencing for genetic diagnosis of 160 patients with primary immunodeficiency in south China.

BACKGROUND: Primary immunodeficiency disorders (PID) is a group of heterogeneous diseases mainly characterized by severe and recurrent infections and an increased susceptibility to lymphoproliferative, atopic, and autoimmune conditions. The clinical diagnosis should preferably be complemented by a genetic diagnosis. To date, PID-related reports from China seldom attempt to make a genetic test for their patients. METHODS: Our study aimed to evaluate demographic data, clinical manifestations, and molecular diagnosis of PID patients from southern China. Moreover, by comparison with previous reports, we provide a picture of the current status of PID in mainland China. A total number of 160 pediatric PID patients (106 males and 54 females) were enrolled, and targeted next-generation sequencing was conducted using 269 PID-related genes and subsequently confirmed by Sanger sequencing and familial segregation analysis. RESULT: The autoinflammatory disease group was the most common subcategory of PID (20%), followed by immune dysregulation (17.5%) and combined immunodeficiencies (16.2%). Antibody deficiency disorders were identified in only 11.9% of the cohort. The putative causative gene was identified in 70 patients (43.8%), and an X-linked pattern was found in 45.7% of the genetically diagnosed patients. CONCLUSION: The current study provides the first collective study of PID phenotypes and genotypes in south China and provides a strong argument for the diagnostic application of targeted next-generation sequencing panels in patients with suspected PID.

Identification of a novel de novo gain-of-function mutation of PIK3CD in a patient with activated phosphoinositide 3-kinase δ syndrome.

Activated phosphoinositide 3-kinase δ (PI3Kδ) syndrome is a newly defined and relatively common primary immunodeficiency, which is caused by heterozygous gain-of-function (GOF) mutations in PIK3CD or PIK3R1. Here, we report a novel de novo GOF mutation (c.1570 T > A, p.Y524N) in PIK3CD in a 6-year-old Chinese girl. The patient suffered recurrent sinopulmonary infection, bronchiectasis, lymphoproliferation, herpesvirus infection, and distinctive nodular lymphoid hyperplasia of mucosal surfaces. Immunological analysis revealed increased CD4+ T cell senescence and B cell immaturity. Further analysis revealed an increase in almost all CD4+ T cell subsets to varying degrees, including effector T cells and Treg cells. Increased levels of plasma T cell-related cytokines corroborated these results. Hyperactivation of the PI3Kδ-Akt-mTOR signaling pathway was also confirmed. Treatment with rapamycin ameliorated the lymphoproliferative immunodeficiency caused by hyperactivation of mTOR. These results expand genetic spectrum of APDS and will facilitate further study of the genotype-phenotype correlation in those with PIK3CD mutations.

Effect of Nanoparticle Morphology on Pre-Breakdown and Breakdown Properties of Insulating Oil-Based Nanofluids.

Nanoparticles currently in use are challenged in further improving the dielectric strength of insulating oil. There is a great need for a new type of nanoparticle to promote the application of insulating oil-based nanofluids in electric industries. This paper experimentally investigates the effect of nanoparticle morphology on pre-breakdown and breakdown properties of insulating oil-based nanofluids. The positive impulse breakdown voltage of insulating oil can be significantly increased by up to 55.5% by the presence of TiO2 nanorods, up to 1.23 times that of TiO2 nanospheres. Pre-breakdown streamer propagation characteristics reveal that streamer discharge channels turn into a bush-like shape with much denser and shorter branches in the nanofluid with TiO2 nanorods. Moreover, the propagation velocity of streamers is dramatically decreased to 34.7% of that in the insulating oil. The greater improvement of nanorods on the breakdown property can be attributed to the lower distortion of the electric field. Thus, when compared with nanospheres, pre-breakdown streamer propagation of nanofluid is much more suppressed with the addition of nanorods, resulting in a greater breakdown voltage.

[Clinical features and mutational analysis of a case with Sensenbrenner syndrome].

OBJECTIVE: To explore the clinical characteristics of a patient with Sensenbrenner syndrome (also called cranioectodermal dysplasia type 3) caused by mutation of intraflagellar transport (IFT) 43 gene. METHODS: The clinical data of the patient was retrospectively analyzed. The target genes was the patient were captured and subjected to next generation sequencing. Suspected mutations were verified through Sanger sequencing. RESULTS: The patient, a-13 year-and-5-month-old girl, was admitted for anemia and renal dysfunction for 8 months. Clinically, she has featured short stature, short limbs, brachydactylia, tooth agenesis, and retinal dystrophy, high-degree myopia, and chronic renal failure. Gene sequencing showed that she has carried a homozygous c.1A>G (p.M1V) mutation of the IFT43 gene, for which both of her parents were heterozygous carriers. CONCLUSION: c.1A>G (p.M1V) mutation of the C14ORF179/IFT43 gene is the cause for praecox chronic renal failure in children. Genetic testing can facilitate the diagnosis of this rare disorder. For affected families, prenatal diagnosis should be provided.

A Fiber Bragg Grating-Based Dynamic Tension Detection System for Overhead Transmission Line Galloping.

Galloping of overhead transmission lines (OHTLs) may induce conductor breakage and tower collapse, and there is no effective method for long distance distribution on-line galloping monitoring. To overcome the drawbacks of the conventional galloping monitoring systems, such as sensitivity to electromagnetic interference, the need for onsite power, and short lifetimes, a novel optical remote passive measuring system is proposed in the paper. Firstly, to solve the hysteresis and eccentric load problem in tension sensing, and to extent the dynamic response range, an 'S' type elastic element structure with flanges was proposed. Then, a tension experiment was carried out to demonstrate the dynamic response characteristics. Moreover, the designed tension sensor was stretched continuously for 30 min to observe its long time stability. Last but not the least, the sensor was mounted on a 70 m conductor model, and the conductor was oscillated at different frequencies to investigate the dynamic performance of the sensor. The experimental results demonstrate the sensor is suitable for the OHTL galloping detection. Compared with the conventional sensors for OHTL monitoring, the system has many advantages, such as easy installation, no flashover risk, distribution monitoring, better bandwidth, improved accuracy and higher reliability.

A new diterpenoid from the leaves of Platycladus orientalis.

A new diterpenoid, 17-methyl-8, 13-labdadien-15, 16-olid-19-oic acid methyl ester (1), along with two known compounds 2 and 3, were isolated from the leaves of Platycladus orientalis (L.) Franco. The structures were confirmed based on the analysis of HR-MS, 1D-NMR, and 2D-NMR spectra and the configuration of 1 was confirmed by the single-crystal X-ray diffraction.

Tracing Acetylene Dissolved in Transformer Oil by Tunable Diode Laser Absorption Spectrum.

Dissolved gas analysis (DGA) is widely used in monitoring and diagnosing of power transformer, since the insulation material in the power transformer decomposes gases under abnormal operation condition. Among the gases, acetylene, as a symbol of low energy spark discharge and high energy electrical faults (arc discharge) of power transformer, is an important monitoring parameter. The current gas detection method used by the online DGA equipment suffers from problems such as cross sensitivity, electromagnetic compatibility and reliability. In this paper, an optical gas detection system based on TDLAS technology is proposed to detect acetylene dissolved in transformer oil. We selected a 1530.370 nm laser in the near infrared wavelength range to correspond to the absorption peak of acetylene, while using the wavelength modulation strategy and Herriott cell to improve the detection precision. Results show that the limit of detection reaches 0.49 ppm. The detection system responds quickly to changes of gas concentration and is easily to maintenance while has no electromagnetic interference, cross-sensitivity, or carrier gas. In addition, a complete detection process of the system takes only 8 minutes, implying a practical prospect of online monitoring technology.

[Application of lung ultrasound examination in severe high altitude pulmonary edema].

OBJECTIVE: To investigate the application value of lung ultrasonic on severe high altitude pulmonary edema. METHODS: A prospective, single-blind, case-control study was conducted. Sixty patients with severe high altitude pulmonary edema admitted to Qinghai University Affiliated Hospital from February 2015 to May 2017 were enrolled. The patients were divided into 2 500-3 000 m group, 3 000-3 500 m group and 3 500-4 200 m group according to different altitudes,with 20 patients in each group. The acute physiology and chronic health evaluation II (APACHE II) score was recorded before and 12 hours and 24 hours after treatment. The arterial partial pressure of oxygen (PaO2) was determined by blood gas analysis, and the oxygenation index (PaO2/FiO2) was calculated. Bedside ultrasound scanning was used to determine B line number and pulmonary artery pressure (PAP), and B line score was calculated to reflect lung water content. The correlation between B line score and PaO2/FiO2, PAP and APACHE II scores at each time point was analyzed by Pearson correlation analysis. RESULTS: None of 60 patients died or exited, all of them were enrolled in the final analysis. There was no significant difference in PaO2/FiO2, PAP, APACHE II score or B line score among different altitudes groups (all P > 0.05). Repeated measurement variance analysis showed that the effects of different altitudes on PaO2/FiO2, PAP, APACHE II score and B line score were not statistically significant (F value was 0.312, 0.014, 1.098, 0.236, and P value was 0.340, 0.791, 0.733, and 0.986, respectively). The PaO2/FiO2, PAP, APACHE II score and B line score in all groups were improved obviously from 12 hours after treatment, and the improvements at 24 hours were more than those at 12 hours (all P < 0.05). Repeated measurement variance analysis showed that the effect at different time points on PaO2/FiO2, PAP, APACHE II score and B line score was statistically significant (F value was 1 844.270, 121.690, 1 173.175, 19 426.968, all P < 0.001). The interaction effects of different altitudes and different time points on PaO2/FiO2, PAP, APACHE II score and B line score were not statistically significant (F value was 0.304, 0.404, 1.172, 1.403, and P value was 0.875, 0.805, 0.327, and 0.591, respectively). Pearson correlation analysis showed that there was a significant negative correlation between B line score and PaO2/FiO2 before and after treatment (r value was -0.579, -0.522, and -0.386, all P < 0.01), indicating that the more the B line, the more severe the pulmonary edema, and the worse the oxygenation; with the decrease in B line after treatment, the pulmonary edema was gradually alleviated, and oxygenation was gradually improved. There was a significant positive correlation between B line score and APACHE II score before and 24 hours after treatment (r value was 0.484 and 0.536, both P < 0.01), indicating that the more the B line, the more severe the patient; with the decrease in B line after treatment, the patient's condition improved after treatment. There was only a weak correlation between B line score and PAP at 24 hours after treatment (r = 0.317, P = 0.014), indicating that PAP was not a sensitive indicator in the degree of pulmonary edema in patients. CONCLUSIONS: The more the B line in patients with severe high altitude pulmonary edema, the more severe of the pulmonary edema, and the more severe of the patient. There was no significant correlation between the B line score and PAP. Pulmonary ultrasonography can still be used not only in the plain and low elevation areas, but in the high altitude areas, as a reliable method to evaluate the severity of pulmonary edema.