bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-channel Feature Extraction and Super-Resolution Reconstruction of Remote Sensing Images
Authors: Zhang Zheng , Zhang Jiabin , Liu Chang’an
Published: August 2021

Super-resolution reconstruction is an imaging method to improve image resolution. It refers to reconstruct a clear high-resolution image from a low-resolution image. High-resolution remote sensing images can provide more detailed information and higher density, but in the field of remote sensing, because of the limitation of the hardware and vast distances, the remote sensing images are fuzzy sometimes. To facilitate subsequent tasks, this paper proposes a multi-channel feature extraction generative adversarial remote sensing image reconstruction method. According to the characteristics of remote sensing image, a generator is designed, which adds Laplace operator to enhance the edge information of the image, and uses multi-channel feature extraction, which not only enhances the ability of feature extraction but also reduces the number of parameters. In this paper, the super-resolution reconstruction task is carried out based on the 2X magnification factor, and the experimental results are evaluated on SET5/14 and NWPU-RESISC45 dataset. The experimental results show that the images generated by this method have a higher detailed texture and better super-resolution reconstruction effect of remote sensing images.
Research on Feature Enhancement for Small Object Detection
Authors: Tang Yuyao , Gu Bingxue , Jiang Bo
Published: August 2021

Small object detection is a challenging research direction in the field of computer vision, due to the low resolution and restricted information of small objects. At present, the general detectors only use appearance features to classify and locate objects, but they are prone to failure under the interference of background noise. On the other hand, the detector based on deep neural network has excellent performance on large scale, but it is difficult to extract enough information of small objects. This paper proposes a feature enhancement network (FENet), which contains two modules. The Residual feature enhancement (RFE) module combines residual learning and sub-pixel convolution to improve the resolution of input small objects and remove image noise. The Attention Feature Pyramid (AFP) module integrates the feature pyramid and attention mechanism, which can extract context information and filter redundant context information. At the same time, considering the imbalance of the contribution of large and small objects to the loss function during the training process, a feedback-driven function is introduced to solve the problem of uneven loss under multiple scales. Experimental results show that compared with the existing small object detection methods, our method has better performance.
Wind characteristic in the complex underlying terrain as studied with CALMET system
Authors: Liao Rongwei , Fang Xiaoyi , Liu Huaiyu , Zhou Rongwei , Zhang Lei , Zhu Yuzhou , Zhang Dongbin , Meng Fanchao
Published: August 2021

In the present study, the wind data during two synoptic processes observed by the surface wind tower in the Tibetan Plateau and the high spatial resolution model data simulated by CALMET were be evaluated, the horizontal and vertical distribution characteristic of the model wind data around the region of the wind tower point and the reference point were be analysed. Results showed that the wind observation data during the two processes in the nearsurface boundary were a well consistency. The horizontal distribution of the wind fields were consistent at the moment of the maximum wind speed during the two processes. The trend of the ten minute mean wind speed were upward with time variations. The air was flowed from the mountain ridge to the mountain valley over the complex region. The vertical distribution of the wind speed had more relevant that the correlation coefficient were 0.6811(α = 0.05) in the observation tower point and 0.8304 (α = 0.05) in the reference point between 16:00 pm Jan 30th and 16:00 pm Jan 31st. The advantages of using the advanced numerical models will be reflected over the extremely complex underlying terrain where the lack of observation stations.
Strategy for Enhancing Fairing Air Conditioning Security Capacity in the On-Time Launch of Chinese Mars-1 Exploration
Authors: Junxin Zhang , Wenan Zhong , Zhongye Wu , Laping Xu , Gang Li , Chuang Zhang , Xiaojie Zhang , Yuchao Wang
Published: August 2021

For the launch of Chinese Mars-1 exploration in a coastal spaceport at noon, summer, there are issues such as big fairing size, complex fairing layout and uncertain flow field of fairing. The author conducted analysis of fairing air conditioning security by thermodynamic modeling calculation and CFD simulation and proposed specific improvement measures to secure on-time launch according to the calculation analysis conclusions. Special test verification was conducted after the carrier rocket transfer. The improvement measures were proven to be effective. During mission launch, the fairing environment security is good. After fairing air conditioning decoupling, the fairing inside temperature rise is within the required scope, ensuring on-time launch of Mars exploration.
TODA Passive location for UAV based on chicken swarm algorithm
Authors: Dong Zhiyuan , Wang Pei , Guo Ying , Liang Qinqin , Dong Yue , Chen Lve , Lu Weitao
Published: August 2021

Accurate positioning of drones is one of the key technologies for drone management and security. Aiming at the characteristics of the active emission of electronic radiation signals during the operation of UAVs, the passive positioning method based on multi-station time difference of arrival (TDOA) is studied, and the problem of solving the nonlinear equation of time difference of arrival passive location is transformed into an optimization problem of seeking the extreme value of the time difference likelihood function. The chicken swarm algorithm is used to search for the best positioning coordinates. The simulation results show that the chicken swarm algorithm can quickly and stably converge to the target position in time difference of arrival passive location system.
Study on appearance and electrical properties of reused solar modules
Authors: Wang Xiaojing , Huang Xiaoli
Published: August 2021

A test platform for reused solar modules was established in Wuhan in order to study the appearance changes, aging problems and degradation rate in electrical properties of the reused modules. The photovoltaic modules were mono-Si modules produced by Siemens in 1996. It was found that there was moisture at the edge of the modules. The aging of tin-coated copper strip was obvious, and there was blackening phenomenon. There were many white spots on the solar cells around the tin-coated strip, and the solar cells turned blue locally. The average annual power attenuation rate of different modules varied greatly, but it was mainly related to the increase of series resistance of modules. The integrated average annual power attenuation of PV modules was about 3.59% during 4 years.
Classification of geotextiles and analysis on tests for their tensile properties
Authors: Xu WEili , Huang Wentao , Cai Yundong , Tao Junru
Published: August 2021

Geotextiles are classified into various types which are Synthetic staple fibers needle-punched nonwoven geotextiles, Synthetic filament spunbond and needle-punched nonwoven geotextiles, Synthetic filament woven geotextiles, Slit and splitfilm yarn woven geotextiles, Plastic woven film yarn geotextile based on different weaving methods and property parameters. The applicability of wide-width strip method and narrow strip method for testing the tensile properties is compared and analyzed.
Factors affecting the formation of heterocyclic amines in sauced pork
Authors: Jiayun Kang , Haibin Li , Yu Hao , Siyu Shi , Ting Li , Wenhui Liang , Meixia Pang , Jinghua Qi , Fang Wang
Published: August 2021

To assess the factors affecting the formation of heterocyclic amines (HAs) in sauced pork, an orthogonal experiment about fat content, braising time and the number of braising times was designed, and the effects of common seasonings and seven Chinese spices on HAs formation were conducted. It was found that higher fat content, increasing braising time and the number of braising times would promote the formation of HAs. Sugar, salt and spices exhibited a reduction in HAs formation in sauced pork. 0.01% of clove could inhibit the formation of HAs by 36.21%. Notably, the inhibitory effect on HAs was significantly correlated with the concentration of spices.
Preparation of Selective Adsorption Materials Based on AI203 and their Adsorption Properties for Sr2+
Authors: Long-xian LI , Zhi-hui Du , Yan-jun Wang , Hong-jun Cao , Yang Yang
Published: August 2021

Aiming at the selective adsorption treatment of 90Sr in radioactive waste liquid, we need to synthesize MnO2 and other inorganic ion exchanger with high selectivity for Sr2+ in the waste water, find the best material ratio, and prepare the raw material liquid. The feed liquid is blown into the hot dimethylsilicone oil by the self-made spherical particle preparation device and loaded on the Al2O3 matrix. The composite adsorbent with appearance and size similar to ion exchange resin was prepared. The physicochemical properties of the composite adsorbent were characterized by SEM,FT-IR and XRD.Different concentrations of strontium ion solution were prepared to study the change of adsorption capacity of Sr2+ at different time. The effects of pH on the adsorption properties of the adsorption properties under the influence of different initial concentrations and different coexisting ions were studied. According to the experimental data, the pseudo first order and quasi second order kinetic first order and quasi second order kinetic equations were used to fit the adsorption process. Two typical adsorption isotherm models, Langmuir and Freundlich models, were used to describe the adsorption process of Sr2+ by composite adsorbents.
Progress of proton exchange membrane fuel cell
Authors: Xu Zhaohe
Published: August 2021

The rapid development of the economy of China leads to the significant growth of energy production and consumption demand. At present, the total amount of greenhouse gas emissions has ranked second in the world. To meet the challenges caused by global climate change and environmental pollution as well as realize the sustainable development of our country’s economy, carbon neutrality should be achieved. As a new type of low-temperature fuel cell, proton exchange membrane fuel cell (PEMFC) attracts a lot of attention due to its safe and environmentally friendly characteristics. However, the operating efficiency of the current commercial PEMFC is rather low (about 50%), which means that about half of the energy will be released as thermal energy. The stable and reliable heat dissipation of the fuel cell has a decisive impact on its performance and life, i.e., thermal management issues are particularly important for the efficiency and stability of the PEMFC stack. This article reviews the thermal management of PEMFC and analyzes the specific applicable conditions of cooling methods as well as the latest developments in thermal management methods. Specifically, it focuses on the thermal characteristics of PEMFC and its effects on performance and life. Besides, the PEMFC thermal management schemes and control strategies under different cooling methods are also summarized.
Cost comparison and difference analysis of prefabricated concrete shear wall structure housing
Authors: Liurui  , Tongliang Xiao
Published: August 2021

This paper makes a deep comparison and research on the cost of prefabricated concrete structure which is popularized vigorously by our country. By comparing the cost of three high-rise concrete residential projects with different prefabrication rates, this paper makes a detailed comparison of the total above-ground cost, civil construction and installation, and the cost of prefabricated components. On this basis analyzes the influence of adjusting prefabricated components on the prefabrication rate and the influence of prefabrication rate on the change of cost. Finally, it is discussed that the cost of prefabricated housing project is higher than that of traditional cast-in-place concrete housing mainly because of the increase of steel and concrete content of prefabricated components, transportation cost, main material consumption and comprehensive unit price. In this paper, the cost comparison and difference of prefabricated housing provides reference and reference for the future cost analysis of prefabricated housing.
The material comparison design of penstock pipe for a hydroelectric pumped storage station
Authors: Zhuqiao Ma , Yang Lu , Fan Hu , Yijie Huang , Jianping Zhao
Published: August 2021

Penstock pipe belongs to special pressure equipment, which has the risk of explosion. Therefore, it is necessary to strengthen the analysis of common accident damage forms and causes of penstock pipe, and do a good job in quality inspection to ensure the safe operation of penstock pipe. This paper mainly studies the penstock pipe of hydraulic storage power station. In the two kinds of steel, the more suitable steel structure is selected by semi elliptical crack analysis and FAD evaluation. According to the experimental data, steel B is more suitable for this structure. Because the failure time of the material, we make thickness correction with MATLAB. Finally, according to the analysis results, it is more appropriate to select steel B as the material of the penstock.
Effect of pruning on endogenetic hormone content associated with differentiation of blueberry flower buds
Authors: Liu Jundou , Ye Xiaoshuang , Yu Gengyan , Kang Xiaoru , Wang Xun
Published: August 2021

In this study, the relationship between pruning methods and endogenous hormone contents related to flower bud differentiation of Brigitta blueberries cultivated in Southwest China was studied. We performed the top pruning in June. The contents of endogenous hormones related to flower bud differentiation of blueberry were measured and analyzed. After top pruning, there was no significant change in the content of ethylene among the five endogenous hormones, but top pruning had a significant effect on the content of the other four hormones, which indicated that top pruning could affect flower bud differentiation by regulating the content of endogenous hormones.
Kinetic study on silicon-activation reaction of sodium carbonate roasting electrolytic manganese residue
Authors: Lv Ying , Peng Qiuju , Li Jia , Liu Xingyu , Chen Bowei , Zhang Mingjiang
Published: August 2021

In order to explore the economic and comprehensive utilization of electrolytic manganese residue (EMR), the reaction kinetics of sodium carbonate roasting EMR were studied by using the model of flake structure minerals. The results showed that the initial roasting reaction was controlled by chemical reaction, while the middle and late reaction is controlled by diffusion. From the content of available silicon and the change node of the control type, the roasting reaction was basically completed in the initial stage. Therefore, chemical reaction control was the determining factor affecting the available silicon content in the process of sodium carbonate roasting EMR.
Study on rapid formation of aerobic granular sludge promoted by addition of Fe2+
Authors: Wang Ke , Zhang Xiaolei , Song Wei , Song Tao , Li Ji
Published: August 2021

The aerobic granular sludge (AGS) process has been regarded as a promising sewage treatment technology. Compared with the activated sludge process, AGS process has the advantages of high efficiency and saving space. However, AGS process has several limitations in its application such as long cultivation cycle and easy disintegration. In this study, Fe2+ was added to the wastewater to cultivate AGS. The improvement on the cultivation of AGS with the addition of Fe2+ was investigated by analyzing the characteristics of AGS and the removal efficiency of pollutants. The results showed that adding Fe2+ (3~5 mg/L) to the reactor could effectively promote the formation of AGS. The sludge particles could be granulated within 7 days with the average particle size of more than 0.35 mm. In addition, the SEM showed that the dominant microorganisms were coryneform bacteria inside of the AGS. The XRD results indicates that the Fe2+ was converted into Fe2O3 presenting in AGS. The mixed liquid suspended solids (MLSS) and the sludge volume index at 30 min (SVI30) was 3.1 g/L and 40 mL/g, respectively, at the 40th day. The COD and NH4
+-N were effectively removed by AGS. This study could provide an effective approach for rapid formation of AGS.
Effect of surfactants on anti-Escherichia coli ability of MgO nanoparticles
Authors: Li Xiaoyi , Zhao Jiao , Zhu Yimin
Published: August 2021

MgO nanoparticles (MgO NPs) were obtained by a simple hydrothermal-calcination method. The influence of three different surfactants on the surface morphology, particle size and antibacterial performance of MgO NPs was investigated. The SEM results indicated that compared with using benzoic acid and citric acid, the MgO sample has more regular flake morphology and well dispersion, moreover, its particle size has more small and uniform when EDTA-2Na was used as the surfactant. The colony-forming unit count and optical density (OD) measurement results suggested that MgO NPs prepared using EDTA-2Na had the best antibacterial activity against Escherichia coli (E. coli), which might be originated from the small particle size and low aggregation. Our study demonstrated that using proper surfactant was a key way during the synthesis process to control the size and morphology of MgO NPs and enhance its antibacterial efficiency, and this way was expected to be applied to other inorganic antibacterial agents.
Effect of different organic salts on ammonia volatilization in ammonium nitrate
Authors: Wang Wei , Pang Shu-Feng
Published: August 2021

The ammonium salts and organic salts are the important components of atmospheric aerosols. The reaction between the two salts will cause the release of NH3, hence, affecting the budget of NH3in the atmosphere. Furthermore, the equilibrium partitioning of NH3in the gas and particle phases plays a key role in the evolution of chemical composition and size of fine atmospheric particles. In this work, the chemical composition evolution processes of mixed particles consisting of four different organic acid salts (sodium oxalate (SO), sodium malonate (SM), sodium succinate (SS), sodium pyruvate (SP)) with ammonium nitrate (AN) were measured by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The release of NH3were gained by monitoring the changes in the absorbance of NH4+in mixed organic acid salts/AN particles under 70% relative humidity (RH). After 127 minutes, the remaining ammonium content in the four mixed aerosols was 84.2%, 71.6%, 57.1%, and 28.7% for SO, SM, SS, and SP mixed with AN, respectively, which is lower than that in pure AN aerosol (97%). This study may help to further understand the conversion process between organic salts and AN in the atmosphere, as well as the NH3cycles in the atmosphere.
Application research of internal electrolysis as pre-treatment for berberine wastewater biodegradation
Authors: Xingfu Xue
Published: August 2021

The composition of the berberine wastewater is complicated with high concentration of chemical oxygen demand (COD). Because it is hard to be degraded by traditional biochemical treatment and causes serious environmental pollution. The applicability of internal electrolysis to improve the biodegradability of berberine wastewater to be treated biologically was investigated. The wastewater was originated from a factory producing berberine. Treatability studies were conducted under laboratory conditions in order to determine the operational conditions to enhance the biodegradation of the wastewater.The major operational conditions, such as the initial pH, the second stage pH, the volume ratio of iron-carbon microelectrolysis filler to waste water and aeration time were investigated in the paper. The result of the experiment shows that the initial pH 2.0-2.5, second stage pH 9, the best volume ratio of iron-carbon micro-electrolysis packing and wastewater is 1:1 and the the residence time control in 120 minutes are the best operating parameters on the berberine wastewater treatment.
Case study on the application of low-temperature plasma integration technology for the treatment mercury-containing waste gas from the crushing process of waste fluorescent lamps
Authors: Qinzhong Feng , Yang Chen , Liyuan Liu , Shihao Wei , Junfeng Wang , Yue Li , Ying Shen , Xu Feng
Published: August 2021

Because mercury has the characteristics of volatility, toxicity and global migration, mercury pollution has become a hot, difficult and focus issue of global concern. Based on China’s environmental technology verification method, the case study for low-temperature plasma integrated technology for the treatment mercury-containing exhaust gas in the treatment process of waste fluorescent lamps was carried out. The total gaseous mercury in the exhaust gas after treatment was less than 0.01mg/m3, which met the emission limit requirements in the Emission Standard (GB16297-1996). The pulse voltage of the plasma power supply is 10-35kV, the pulse current is 8-160A, and the pulse frequency is100-1000Hz. Case study showed that low temperature plasma integrated treatment technology is the available technology for advanced treatment of mercury-containing waste gas.
Research Status of Low-Temperature Electrolyte Additives for Lithium-ion Batteries
Authors: Han Fujuan , Chang Zenghua , Liu Xingge , Li Alin , Wang Jing , Ding Haiyang , Lu Shigang
Published: August 2021

Lithium-ion batteries have been the most promising energy storage technology in the field of new energy due to their advantages such as high specific energy. With the further expansion of the application range, higher requirements are placed on the low-temperature performance of the battery. The development of suitable electrolyte additives to improve the interface structure of the electrode and the electrolyte is an effective and economically feasible method to improve the low-temperature performance of the battery. This article reviews the research progress of low-temperature electrolyte additives for lithium-ion batteries in recent years. It summarizes the action mechanism of low-temperature electrolyte additives from three aspects: organic solvent additives, lithium salt additives, and new additives. The development of low-temperature electrolyte additives in the next step was prospected.
Study on a new composite gel system
Authors: Yi Sun , Wei Gao , Ding-Xue Zhang
Published: August 2021

A composite gel system was developed to solve the problems of low gel forming viscosity, gel forming and high salinity resistance in pH range of 6~8. The viscosity of the gel was determined by rotary viscometer, and the performance of the composite gel was analyzed. The pH of the composite gel, the gelation property of the mineralized degree and the plugging test of the sand filling pipe and the oil displacement experiment were carried out. The results showed that the gel performance of the composite gel was better than that of the conventional gel system at 60 degrees Celsius. The viscosity of the composite gel reached 10000 mPa S, at 0.1% polyacrylamide concentration, the gel forming range of pH was 6~12, and the viscosity of 20000 mg/L NaCl solution reached 15000 mPa/s, which had better salt resistance. The plugging test of sand filling pipe showed that the plugging rate of the gel to permeation layer was close to 90%, and the plugging ability was better. After 18% 0.2pv injection, the recovery rate increased by about 18%, which can meet the requirements of profile control in most oilfields.
Comparative Study on the Determination of heavy metals in Soil by XRF and ICP-MS
Authors: Li Wenyu , Niu Ning , Guo Ning , Zhou Hao , Bu Jiangping , Ding Aifang
Published: August 2021

The contents of Cr, Ni, Cu, Zn, As, Pb and Cd in standard soil for composition (GBW07403) and two soil samples were determined by XRF and ICP-MS, respectively. The results showed that XRF had higher precision than ICP-MS in the determination of seven metals in standard soil, but the relative errors of Ni, As and Cd were larger, up to -33%~22.7%. XRF and ICP-MS were used to determine contents of seven kinds of heavy metals in 2 soil samples, respectively. Both methods had high precision. F test showed that there was no significant difference in precision between the two methods except for Cd in No.2 soil. The t test showed that there were significant differences by the two methods for the determination of other heavy metals except for Cd and Cu (P ≤0.05). Although the method of XRF was fast and simple, its accuracy and comparison with other experimental methods need to be further studied due to the sample matrix effect.
Design and application of a fluorescent probe for rapid detection of H2S
Authors: Su Sa
Published: August 2021

H2S is an endogenous gaseous signal molecule with cell protective function, which plays a critical part in many physiological and pathological processes. On the one hand, abnormal fluctuations of the concentration of hydrogen sulfide in the human body are closely related to diseases such as Down's syndrome, Alzheimer's, diabetes and cirrhosis of the liver. On the other hand, acts as an antioxidant in the body, hydrogen sulfide can protect cells from damage caused by reactive oxygen species. Therefore, it is indispensible to detect hydrogen sulfide in living organisms. A fluorescent probe—NX-H2S, was constructed using azide group as the recognition group and naphthalimide as the framework. The spectroscopic properties of the probe were explored comprehensively. The experiment results show that NX-H2S exhibits not only a fast response (5 min) but also excellent sensitivity and selectivity toward H2S. In addition to the rapid detection of H2S in vitro, NX-H2S can also be successfully applied to the fluorescence imaging analysis of endogenous and exogenous H2S in living cells.
Technical research on heat storage and function expansion of thermos cup
Authors: Yong Jiang , Sisheng Wei , Xinru Han , Wenwen Ma , Yuting Zhao , Shuhao Feng , Shanjie Han
Published: August 2021

The new multi-functional heat preservation cup can not only achieve long-term heat preservation, but also keep the water temperature at a more suitable temperature for drinking in a short time. It uses paraffin phase change heat storage material as the filler of the inner liner sandwich, which can absorb the heat in the water temperature and achieve rapid cooling; solar panels are used above the cup cover to supply power for electronic devices, which can save energy and protect the environment and avoid the trouble of charging back and forth; At the same time, a variety of electronic devices are added to the cup cover to enrich the customer's experience.
Finite Element Analysis and Theoretical Verification of Natural Vibration of Novel Simply-supported Beams
Authors: Zhong Rongqiang , Zhao Yi , Yao Lirong , Liu Jining , Li Zhiming , Guo jing
Published: August 2021

In order to investigate the dynamic characteristics of I-shaped novel simply-supported beams with the upper flange of rectangular high-strength concrete filled steel tube (RHCFST), the modal analysis of 16 simply-supported beams is conducted by ANSYS finite element software. The first order frequencies of the specimen beams are obtained in the Y direction. Based on the concentrated mass method, the frequencies of the specimens are theoretically calculated. By comparison the maximum error of the first-order frequency is 3.80%, which is in good agreement and can meet the precise requirements of practical engineering. The result shows that the first three order vibration modes of the specimen are consistent with the theoretical vibration modes. For the first-order vibration mode, the proportion of the effective mass to the total mass of the specimen is 79.2 % in the Y direction. Therefore, the first-order vibration mode in Y direction should be mainly taken into consideration for this type of beams during the structural design.
Fabrication and characterization of large-area suspended MoSe2 crystals down to the monolayer
Authors: Varghese Sebin , Saleta Reig David , Dudley Mehew Jake , Block Alexander , El Sachat Alexandros , Chávez-Ángel Emigdio , Sledzinska Marianna , Ballesteros Belén , Sotomayor Torres Clivia M , Tielrooij Klaas-Jan
Published: August 2021

Many layered materials, such as graphene and transition metal dichalcogenides, can be exfoliated down to atomic or molecular monolayers. These materials exhibit exciting material properties that can be exploited for several promising device concepts. Thinner materials lead to an increased surface-to-volume ratio, with mono- and bi-layers being basically pure surfaces. Thin crystals containing more than two layers also often behave as an all-surface material, depending on the physical property of interest. As a result, flakes of layered materials are typically highly sensitive to their environment, which is undesirable for a broad range of studies and potential devices. Material systems based on suspended flakes overcome this issue, yet often require complex fabrication procedures. Here, we demonstrate the relatively straightforward fabrication of exfoliated MoSe2 flakes down to the monolayer, suspended over unprecedentedly large holes with a diameter of 15 µm. We describe our fabrication methods in detail, present characterization measurements of the fabricated structures, and, finally, exploit these suspended flakes for accurate optical absorption measurements.
Enzymatic determination of d-alanine with l-alanine dehydrogenase and alanine racemase
Authors: Ashida Hiroyuki , Sawa Yoshihiro , Yoshimura Tohru
Published: August 2021

An enzymatic assay system of d-Ala, which is reported to affect the taste, was constructed using alanine racemase and l-alanine dehydrogenase. d-Ala is converted to l-Ala by alanine racemase and then deaminated by l-alanine dehydrogenase with the reduction of NAD+ to NADH, which is determined with water-soluble tetrazolium. Using the assay system, the d-Ala contents of 7 crustaceans were determined.
Neutrophils Contribute to Severity of Tuberculosis Pathology and Recovery From Lung Damage Pre- and Posttreatment
Authors: Nwongbouwoh Muefong Caleb , Owolabi Olumuyiwa , Donkor Simon , Charalambous Salome , Bakuli Abhishek , Rachow Andrea , Geldmacher Christof , Sutherland Jayne S
Published: August 2021

Background

Despite microbiological cure, about 50% of tuberculosis (TB) patients have poor lung recovery. Neutrophils are associated with lung pathology; however, CD16/CD62L-defined subsets have not been studied in TB. Using flow cytometry, we monitored frequencies, phenotype, and function of neutrophils following stimulation with Mycobacterium tuberculosis (Mtb) whole cell lysate (WCL) and ESAT-6/CFP-10 fusion protein (EC) in relation to lung pathology.

Methods

Fresh blood from 42 adult, human immunodeficiency virus (HIV)–negative TB patients were analyzed pre- and post-therapy, with disease severity determined using chest radiography and bacterial load. Flow cytometry was used to monitor frequencies, phenotype, and function (generation of reactive oxygen species [ROS], together with CD11b, tumor necrosis factor, and interleukin 10 [IL-10] expression) of neutrophils following 2-hour stimulation with Mtb-specific antigens.

Results

Total neutrophils decreased by post-treatment compared to baseline (P = .0059); however, CD16brCD62Lbr (segmented) neutrophils increased (P = .0031) and CD16dimCD62Lbr (banded) neutrophils decreased (P = .038). Banded neutrophils were lower in patients with severe lung damage at baseline (P = .035). Following WCL stimulation, ROS from segmented neutrophils was higher in patients with low Mtb loads even after adjusting for sex (P = .038), whereas IL-10–expressing CD16dimCD62Llo cells were higher in patients with mild damage (P = .0397) at baseline.

Conclusions

High ROS generation, low levels of banded neutrophils, and high levels of IL-10–expressing CD16dimCD62Llo neutrophils are associated with reduced lung pathology at diagnosis. Hence, neutrophils are potential early indicators of TB severity and promising targets for TB host-directed therapy.
Archaeal pseudomurein and bacterial murein cell wall biosynthesis share a common evolutionary ancestry
Authors: Subedi Bishwa P , Martin William F , Carbone Vincenzo , Duin Eduardus C , Cronin Bryan , Sauter Julia , Schofield Linley R , Sutherland-Smith Andrew J , Ronimus Ron S
Published: August 2021

Bacteria near-universally contain a cell wall sacculus of murein (peptidoglycan), the synthesis of which has been intensively studied for over 50 years. In striking contrast, archaeal species possess a variety of other cell wall types, none of them closely resembling murein. Interestingly though, one type of archaeal cell wall termed pseudomurein found in the methanogen orders Methanobacteriales and Methanopyrales is a structural analogue of murein in that it contains a glycan backbone that is cross-linked by a L-amino acid peptide. Here, we present taxonomic distribution, gene cluster and phylogenetic analyses that confirm orthologues of 13 bacterial murein biosynthesis enzymes in pseudomurein-containing methanogens, most of which are distantly related to their bacterial counterparts. We also present the first structure of an archaeal pseudomurein peptide ligase from Methanothermus fervidus DSM1088 (Mfer336) to a resolution of 2.5 Å and show that it possesses a similar overall tertiary three domain structure to bacterial MurC and MurD type murein peptide ligases. Taken together the data strongly indicate that murein and pseudomurein biosynthetic pathways share a common evolutionary history.
LD-CNV: rapid and simple discovery of chromosomal translocations using linkage disequilibrium between copy number variable loci
Authors: Comai Luca , Amundson Kirk R , Ordoñez Benny , Zhao Xin , Braz Guilherme Tomaz , Jiang Jiming , Henry Isabelle M
Published: August 2021

Large-scale structural variations, such as chromosomal translocations, can have profound effects on fitness and phenotype, but are difficult to identify and characterize. Here, we describe a simple and effective method aimed at identifying translocations using only the dosage of sequence reads mapped on the reference genome. We binned reads on genomic segments sized according to sequencing coverage and identified instances when copy number segregated in populations. For each dosage-polymorphic 1 Mb bin, we tested independence, effectively an apparent linkage disequilibrium (LD), with other variable bins. In nine potato (Solanum tuberosum) dihaploid families translocations affecting pericentromeric regions were common and in two cases were due to genomic misassembly. In two populations, we found evidence for translocation affecting euchromatic arms. In cv. PI 310467, a nonreciprocal translocation between chromosomes (chr.) 7 and 8 resulted in a 5–3 copy number change affecting several Mb at the respective chromosome tips. In cv. “Alca Tarma,” the terminal arm of chr. 4 translocated to the tip of chr. 1. Using oligonucleotide-based fluorescent in situ hybridization painting probes (oligo-FISH), we tested and confirmed the predicted arrangement in PI 310467. In 192 natural accessions of Arabidopsis thaliana, dosage haplotypes tended to vary continuously and resulted in higher noise, while apparent LD between pericentromeric regions suggested the effect of repeats. This method, LD-CNV, should be useful in species where translocations are suspected because it tests linkage without the need for genotyping.
Association of Circulating Fibrocytes With Fibrostenotic Small Bowel Crohn’s Disease
Authors: Ueno Aito , Jijon Humberto B , Peng Richard , Sparksman Steven , Mainoli Barbara , Filyk Alexis , Li Yan , Wilson Stephanie , Novak Kerri , Panaccione Remo , Hirota Simon , Dufour Antoine , Lu Cathy , Beck Paul L
Published: August 2021

Background

Fibrocytes are hematopoietic cells with features of mesenchymal cells found in the circulation and inflammatory sites implicated in promoting fibrosis in many fibroinflammatory diseases. However, their role(s) in the development of intestinal fibrosis is poorly understood. Here, we investigated a potential role of fibrocytes in the development of fibrosis in Crohn’s disease (CD) and sought factors that may impact their development and function.

Methods

Plasma and mononuclear cells were collected from patients with and without fibrostenotic CD. Fibrocytes defined as CD11b+, CD34+, and Collagen 1+ were correlated with clinical assessments of fibrosis, including evaluation using intestinal ultrasound. We measured the levels of relevant circulating molecules via Luminex and studied the effect of patient plasma proteins on fibrocyte differentiation.

Results

Fibrocyte numbers were increased in CD patients with stricturing Crohn’s disease compared with patients with an inflammatory phenotype (P = .0013), with strong correlation between fibrocyte numbers and acoustic radiation force impulse (ARFI), a measure of bowel elasticity on intestinal ultrasound (R = .8383, P = .0127). Fibrostenotic plasma was a more potent inducer of fibrocyte differentiation in both primary human monocytes and cell line and contained increased levels of cytokines implicated in fibrocyte differentiation compared with plasma from inflammatory patients. Interestingly, increased fibrocyte numbers at time of ultrasound were associated with escalation of medical therapy and endoscopic/surgical management of small bowel strictures at 30 months follow-up.

Conclusions

Circulating fibrocytes strongly correlate with fibrostenotic disease in CD, and they may serve as predictors for escalation of medical +/- surgical therapy.
Antitumor Necrosis Factor-like Ligand 1A Therapy Targets Tissue Inflammation and Fibrosis Pathways and Reduces Gut Pathobionts in Ulcerative Colitis
Authors: Hassan-Zahraee Mina , Ye Zhan , Xi Li , Baniecki Mary Lynn , Li Xingpeng , Hyde Craig L , Zhang Jenny , Raha Nancy , Karlsson Fridrik , Quan Jie , Ziemek Daniel , Neelakantan Srividya , Lepsy Christopher , Allegretti Jessica R , Romatowski Jacek , Scherl Ellen J , Klopocka Maria , Danese Silvio , Chandra Deepa E , Schoenbeck Uwe , Vincent Michael S , Longman Randy , Hung Kenneth E
Published: August 2021

Background

The first-in-class treatment PF-06480605 targets the tumor necrosis factor-like ligand 1A (TL1A) molecule in humans. Results from the phase 2a TUSCANY trial highlighted the safety and efficacy of PF-06480605 in ulcerative colitis. Preclinical and in vitro models have identified a role for TL1A in both innate and adaptive immune responses, but the mechanisms underlying the efficacy of anti-TL1A treatment in inflammatory bowel disease (IBD) are not known.

Methods

Here, we provide analysis of tissue transcriptomic, peripheral blood proteomic, and fecal metagenomic data from the recently completed phase 2a TUSCANY trial and demonstrate endoscopic improvement post-treatment with PF-06480605 in participants with ulcerative colitis.

Results

Our results revealed robust TL1A target engagement in colonic tissue and a distinct colonic transcriptional response reflecting a reduction in inflammatory T helper 17 cell, macrophage, and fibrosis pathways in patients with endoscopic improvement. Proteomic analysis of peripheral blood revealed a corresponding decrease in inflammatory T-cell cytokines. Finally, microbiome analysis showed significant changes in IBD-associated pathobionts, Streptococcus salivarius, S. parasanguinis, and Haemophilus parainfluenzae post-therapy.

Conclusions

The ability of PF-06480605 to engage and inhibit colonic TL1A, targeting inflammatory T cell and fibrosis pathways, provides the first-in-human mechanistic data to guide anti-TL1A therapy for the treatment of IBD.
Risk Factors for Postpartum Disease Activity in Women With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis
Authors: Malhi Gurpreet , Tandon Parul , Perlmutter Jonah Wiseman , Nguyen Geoffrey , Huang Vivian
Published: August 2021

Background

Women with inflammatory bowel disease (IBD) have an increased risk of postpartum disease activity. We aimed to systematically determine the effect of various risk factors on postpartum IBD disease activity.

Methods

Electronic databases were searched through January 2021 for studies that reported risk of postpartum disease activity in women with IBD. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for the impact of IBD phenotype, disease activity, therapy de-escalation, mode of delivery, and breastfeeding on postpartum disease activity. Study bias was determined using the Quality in Prognostic Studies tool.

Results

Twenty-seven observational studies (3825 patients) were included, 15 of which had a high risk of confounding bias. The pooled incidence of women with postpartum active IBD was 31.9% (95% CI, 25.6–38.1). Similar results were seen with ulcerative colitis and Crohn’s disease (CD; OR, 0.96; 95% CI, 0.58–1.59). Those with stricturing (OR, 3.64; 95% CI, 1.31–10.08) and penetrating (OR, 4.25; 95% CI, 1.11–16.26) CD had higher odds of postpartum active IBD. Active disease at conception (OR, 10.59; 95% CI, 1.48–76.02) and during pregnancy (OR, 4.91; 95% CI, 1.82–13.23) increased the odds of postpartum disease activity. Similarly, biologic discontinuation in the third trimester (OR, 1.77; 95% CI, 1.01–3.10) and therapy de-escalation after delivery (OR, 7.36; 95% CI, 3.38–16.0) was associated with postpartum disease activity.

Conclusions

Complicated Crohn’s disease, disease activity at conception and during pregnancy, and de-escalation of biologics during pregnancy or after delivery are associated with postpartum disease activity in women with IBD.
Smooth Fano Intrinsic Grassmannians of Type 2,n with Picard Number Two
Authors: Qureshi Muhammad Imran , Wrobel Milena
Published: August 2021

We introduce the notion of intrinsic Grassmannians that generalizes the well-known weighted Grassmannians. An intrinsic Grassmannian is a normal projective variety whose Cox ring is defined by the Plucker ideal $I_{d,n}$ of the Grassmannian $\textrm{Gr}(d,n)$. We give a complete classification of all smooth Fano intrinsic Grassmannians of type $(2,n)$ with Picard number two and prove an explicit formula to compute the total number of such varieties for an arbitrary $n$. We study their geometry and show that they satisfy Fujita’s freeness conjecture.
Autologous Fat Grafting to the Breast: An Educational Review
Authors: Winkler Nicole S , Tran Alexander , Kwok Alvin C , Freer Phoebe E , Fajardo Laurie L
Published: August 2021

Autologous fat grafting (AFG) is a technique that is increasingly utilized in breast cosmetic and reconstructive surgery. In this procedure, fat is aspirated by liposuction from one area of the body and injected into the breast. The procedure and process of AFG has evolved over the last few decades, leading to more widespread use, though there is no standard method. Autologous fat grafting is generally considered a safe procedure but may result in higher utilization of diagnostic imaging due to development of palpable lumps related to fat necrosis. Imaging findings depend on surgical technique but typically include bilateral, symmetric, retromammary oil cysts and scattered dystrophic and/or coarse calcifications when AFG is used for primary breast augmentation. More focal findings occur when AFG is used to improve specific areas of cosmetic deformity, scarring, or pain following breast cancer surgery. As with any cause of fat necrosis, imaging features tend to appear more benign over time, with development of rim calcifications associated with oil cysts and a shift in echogenicity of oil cyst contents on ultrasound towards anechoic in some cases. This article reviews the AFG procedure, uses, complications, and imaging findings.
Tomato SlPP2C5 Is Involved in the Regulation of Fruit Development and Ripening
Authors: Wang Juan , Xu Yandan , Zhang Wenbo , Zheng Yu , Yuan Bing , Li Qian , Leng Ping
Published: August 2021

Abscisic acid (ABA) regulates plant development mainly through its signaling, in which ABA binds to receptors to inhibit type 2C protein phosphatases (PP2Cs). The exact roles of PP2Cs in fruit development are still unclear. In this work, we verify that tomato SlPP2C5 works as a negative regulator in ABA signaling during fruit development. SlPP2C5 was inhibited by both monomeric and dimeric ABA receptors SlPYLs through ABA dose–dependent way, and it interacted physically with SlPYLs and SlSnRK2s. SlPP2C5 was highly expressed in fruits induced by exogenous ABA. Plants with overexpressed SlPP2C5 had lower sensitivity to ABA, which showed faster seed germination and primary root growth compared to Wild type (WT), while SlPP2C5-suppressed plants were more sensitive to ABA. SlPP2C5-over-expression (OE) delayed fruit ripening onset, while SlPP2C5-RNAi advanced fruit ripening. Alteration of SlPP2C5 expression impacts fruit quality parameters as well, including pericarp thickness, fruit shape index, seed number and weight and the soluble solid content. RNA-seq analysis revealed that there were significant expression differences of genes related to ethylene release and lycopene synthesis between WT and both SlPP2C5-OE and SlPP2C5-RNAi lines with an inversed variation. Taken together, our findings demonstrate that SlPP2C5 plays an important role in the regulation of fruit development, ripening and quality.
Redescription and SSU rRNA gene-based phylogeny of an anaerobic ciliate, Plagiopyla ovata Kahl, 1931 (Ciliophora, Plagiopylea)
Authors: Li Ran , Zhuang Wenbao , Wang Congcong , El-Serehy Hamed , Al-Farraj Saleh A. , Warren Alan , Hu Xiaozhong
Published: August 2021

The morphology and molecular phylogeny of Plagiopyla ovata Kahl, 1931, a poorly known anaerobic ciliate, were investigated based on a population isolated from sand samples collected from the Yellow Sea coast at Qingdao, PR China. Details of the oral ciliature are documented for the first time to our knowledge and an improved species diagnosis is given. The small subunit ribosomal RNA (SSU rRNA) gene was newly sequenced and phylogenetic analyses revealed that P. ovata clusters within the monophyletic family Plagiopylidae. However, evolutionary relationships within both the family Plagiopylidae and the genus Plagiopyla remain obscure owing to undersampling, the lack of sequence data from known species and low nodal support or unstable topologies in gene trees. A key to the identification of the species of the genus Plagiopyla with validly published names is also supplied.
Lentzea tibetensis sp. nov., a novel Actinobacterium with antimicrobial activity isolated from soil of the Qinghai–Tibet Plateau
Authors: Huang Jiao , Huang Ying
Published: August 2021

A novel filamentous Actinobacterium, designated strain FXJ1.1311T, was isolated from soil collected in Ngari (Ali) Prefecture, Qinghai-Tibet Plateau, western PR China. The strain showed antimicrobial activity against Gram-positive bacteria and Fusarium oxysporum. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FXJ1.1311T belonged to the genus

Lentzea

and showed the highest sequence similarity to

Lentzea guizhouensis

DHS C013T (98.04%). Morphological and chemotaxonomic characteristics supported its assignment to the genus

Lentzea

. The genome-wide average nucleotide identity between strain FXJ1.1311T and

L. guizhouensis

DHS C013T as well as other

Lentzea

type strains was <82.2 %. Strain FXJ1.1311T also formed a monophyletic line distinct from the known

Lentzea

species in the phylogenomic tree. In addition, physiological and chemotaxonomic characteristics allowed phenotypic differentiation of the novel strain from

L. guizhouensis

. Based on the evidence presented here, strain FXJ1.1311T represents a novel species of the genus

Lentzea

, for which the name Lentzea tibetensis sp. nov. is proposed. The type strain is FXJ1.1311T (=CGMCC 4.7383T=DSM 104975T).