bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and simulation analysis of spectroscopic system for synchronous atmospheric three-phase water detection based on Raman lidar
Authors: Wang Yu-Feng  , Zhang Jing  , Tang Liu  , Wang Qing  , Gao Tian-Le  , Song Yue-Hui  , Di Hui-Ge  , Li Bo  , Hua Deng-Xin  ,   School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an 710048, China
Published: December 2020

Water is the only atmospheric parameter with three-phase states. The study on distribution and variation in three-phase water is of great scientific significance for understanding cloud microphysics, cloud precipitation physics, and water circulation, especially in the fields of artificial weather process. In the Raman lidar detection technology of three-phase water, it is necessary to solve the problem of high-spectral spectroscopic technique to ensure fine extraction of the echo signal and the detection with high signal-to-noise ratio (SNR). Considering the Raman spectrum characteristics of three-phase water, the influences of filter parameters in the Raman channels on the overlapping characteristics are theoretical simulated and discussed in detail, and the SNR is investigated as well. Regarding the fact that optimal solution can be obtained for neither overlapping nor SNR at the same time, an evaluation function method based on the multi-objective programming problem is proposed to analyze the optimal filter parameters. The results show that the minimum overlapping value and the higher system SNR can be obtained when the central wavelength and bandwidth of the filters are determined to be 397.9 nm and 3.1 nm, 403 nm and 5 nm, 407.6 nm and 0.6 nm in solid water, liquid water and water vapor channel, respectively, and thus the optimal design can be realized for synchronous detection Raman spectroscopic system for three-phase water. Further simulation results show that effective detection can reach above 3.6 km in the daytime and over 4 km on sunny days under a system factor of 1800 J·mm·min for three-phase water Raman measurement in the daytime. Furthermore, the obtained overlapping values are applied to accurate retrieval theory for three-phase water profiles. The simulated profiles of atmospheric water vapor, liquid water and ice water indicate that the water vapor, liquid water and solid water content can be increased synchronously in the cloud layer, and their content, distribution characteristics and the corresponding error are also discussed. The above results validate the feasibility of highspectral spectroscopic technique for detecting the synchronous atmospheric three-phase water, and will provide technical and theoretical support for synchronous retrieval of three-phase water by Raman lidar.
Identifying multiple influential nodes based on region density curve in complex networks
Authors: Kang Ling  , Xiang Bing-Bing  , Zhai Su-Lan  , Bao Zhong-Kui  , Zhang Hai-Feng  ,   School of Mathematical Science, Anhui University, Hefei 230601, China
Published: December 2020

Complex networks are ubiquitous in natural science and social science, ranging from social and information networks to technological and biological networks. The roles of nodes in networks are often distinct, the most influential nodes often play an important role in understanding the spreading process and developing strategies to control epidemic spreading or accelerating the information diffusion. Therefore, identifying the influential nodes in complex networks has great theoretical and practical significance. Some centrality indices have been proposed to identify the influential nodes in recent years, but most of the existing algorithms are only appropriate to the identifying of single influential node. Many times, spreading process is initiated by simultaneously choosing multiple nodes as the spreading sources, such as rumors, opinions, advertisements, etc. Therefore, it is necessary to develop efficient methods of identifying the multiple influential nodes in complex networks. In this paper, a method based on region density curve of networks (RDC) is proposed to identify the multiple influential nodes in complex networks. Firstly, we rearrange all nodes of network in a new sequence, and then plot the region density curve for network. Finally, we identify the multiple influential nodes based on the valley points of region density curve. Using two kinds of spreading models, we compare RDC index with other indices in different real networks, such as degree, degree discount, k-shell, betweenness and their corresponding coloring methods. The results show that the influential nodes chosen according to our method are not only dispersively distributed, but also are relatively important nodes in networks. In addition, the time complexity of our method is low because it only depends on the local information of networks.
First-principles study on Jahn-Teller effect in Cr monolayer film
Authors: Zhang Wei  , Chen Kai-Bin  , Chen Zhen-Dong  ,   1. Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China;,   2. Fujian Provincial Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen 361005, China
Published: December 2020

Computational physics has been used in many scientific research fields, in which first-principles calculation based on density functional theory has made brilliant achievements. Unlike three-dimensional materials, low-dimensional materials present fantastic physical effect, due to the reduction of material dimensions. With the rapid development of two-dimensional materials, people have a more in-depth understanding of them. Requirements for high performance of two-dimensional materials are raised for potential applications, so the exploration of some effects affecting the stability of two-dimensional materials becomes more and more important. Based on the pioneers' work, Jahn-Teller effect is found to have a certain influence on the stabilities of two-dimensional structure of some elements. In the present paper, we explain the stable structure of Cr monolayer film through theoretical calculation, providing a guidance for experimental synthesis. Using first-principles calculation, we study a series of two-dimensional structures (rectangular, square, hexagonal, oblique and centered rectangular) of Cr monolayer film, focusing on the structural stability and electronic properties. Firstly, the equilibrium lattice constant and cohesive energy of each structure are calculated. Then, the bond angle and lattice constant dependence of the total energy are analyzed in detail. Finally, we investigate the energy band structures, total electronic densities of states, charge densities and electron occupation numbers of orbitals. The results show that low-symmetry oblique and centered rectangular lattice are stable in the two-dimensional system of Cr, while high-symmetry square and hexagonal lattices are not stable and the adhesive energy of the rectangular lattices is very small. Two stable structures of Cr monolayer sheet are formed due to hexagonal structure distortion. The hexagonal structure can shape into a centered rectangular structure with the increase of bond angle, while it changes into an oblique structure with the decrease of bond angle. Because of Jahn-Teller effect, the degenerate energy level spontaneously splits. Then the structure deforms into two reduced-symmetry structures, resulting in a stable system. Therefore, we can infer that the Jahn-Teller effect plays a crucial role in the structural stability of monolayer sheet.
Phase field crystal simulation of the effect of temperature on low-angle symmetric tilt grain boundary dislocation motion
Authors: Qi Ke-Wu , Zhao Yu-Hong , Guo Hui-Jun , Tian Xiao-Lin , Hou Hua ,   Material Science and Engineering Institute, North University of China, Taiyuan 030051, China
Published: December 2020

For crystal materials, the grain boundary structure is complex, which is usually the place in which stress concentration and impurity accumulate. Grain boundary structure and movement have a great influence on the macroscopic properties of crystal materials, therefore, it is of great significance to study the microstructure of grain boundary. With the phase filed crystal approach, the structure of low-angle symmetric tilt grain boundary and dislocation motion at nanoscale are studied. The low-angle symmetric tilt grain boundary structure can be described by a dislocation model, in which the grain boundary can be regarded as consisting of a series of edge dislocations at a certain distance. For a relaxation process and applied stress process, the position change of dislocation motion at grain boundaries and the change of free energy density of the system are observed. Furthermore, we also analyze the influence of temperature on the grain boundary structure and the dislocation motion. In the relaxation process, the free energy of the crystal system is higher under high temperature conditions. The results show that the motion of dislocation pairs in the grains can consume the internal energy and release the distortion energy stored at the grain boundary, and thus making the system more stable and the energy reach the lowest value earlier. Simulation results show that the lower the temperature of the system, the faster the free energy density decreases, the faster the regular arrangement rate of atoms increases, the shorter the time required for the free energy density to reach a stable state becomes. And when the grain boundary reaches a steady state, the arrangement of the dislocations becomes more and more regular and arranges in a straight line. For an applied stress process, with the decrease of temperature, the time required for the first encounter of dislocation pairs and the time required for the formation of single crystal become longer, and it takes more time for the first encounter of dislocation pairs in crystals to disappear completely. Further studies also show that with the decrease of temperature, the free energy density exhibits a multi-stage ascending and descending process. The rising process of energy curve corresponds to the stage of dislocation climbing along the grain boundary, and the decline process corresponds to the stage of dislocation decomposition and encounter annihilation. At the same time, the dislocation pairs’ reaction becomes more complex. Finally, the dislocations annihilate with each other.
Photonic microwave waveform generation based on dual-wavelength time domain synthesis technology
Authors: Ma Yan-Na , Wang Wen-Rui , Song Kai-Chen , Yu Jin-Long , Ma Chuang , Zhang Hua-Fang ,   College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China,   College of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China,   School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China
Published: December 2020

Microwave waveforms, such as square waveforms, sawtooth waveforms and triangle waveforms are widely used in radar communication, electronic measurement and medical imaging and so on. Using photonic microwave technology to generate arbitrary microwave waveforms has been a research hotspot.

In this paper, a photonic microwave waveform generation scheme based on dual-wavelength time domain synthesis is proposed and experimentally demonstrated. Used in this scheme mainly are two lasers, two single-drive Mach-Zehnder modulators, a wavelength division multiplexer and a tunable optical delay line. The two Mach-Zehnder modulators are respectively biased at different operating points. When two beams with different wavelengths are superimposed in the time domain, different microwave waveform outputs can be generated. Therefore, by adjusting the bias voltage and modulation depth of the modulator, the phase and amplitude of the modulated optical signal can be controlled, and finally the photonic microwave waveform is generated.

At first, the generation mechanism of square waveform, sawtooth waveform and triangle waveform are analyzed, and the comparisons among ideal square waveform, sawtooth waveform, triangle waveform and their third-order waveforms are made through the simulation analysis. It is verified that third-order waveforms become close to the ideal waveforms. Since the proposed scheme produces higher-order components, and the waveforms of the first three orders are the same as the ideal waveforms, so the scheme has good waveform generation capability. And then square waveform, sawtooth waveform and triangle waveform with a repetition rate of 2.5 GHz are successfully generated experimentally. Thus, experimental results are well consistent with the theoretical analyses. In addition, the system also has good tunable characteristics. By changing the modulation frequency of the modulator, the frequency tuning of the output photonic microwave waveforms can be realized, and square waveform, sawtooth waveform and triangular waveform with a repetition rate of 5 GHz are also experimentally achieved. The repetition rate of the generated microwave waveform is mainly limited by the bandwidth of modulator and electrophotonic detector, so the devices with higher bandwidth can be used to generate arbitrary waveform with a higher repetition rate. Therefore, the scheme has good application prospects.
First-principles study of electronic structure and optical properties of nickel-doped multilayer graphene
Authors: Wang Xiao , Huang Sheng-Xiang , Luo Heng , Deng Lian-Wen , Wu Hao , Xu Yun-Chao , He Jun , He Long-Hui ,   School of Physics and Electronics, Central South University, Changsha 410083, China,   School of Physics and Electronics, Hunan Normal University, Changsha 410006, China
Published: December 2020

Graphene is an ideal two-dimensional crystal with the advantages of high conductivity, unique physical and chemical properties, and high specific surface area. Especially, because of its super excellent electronic properties, graphene may substitute the traditional semiconductor silicon material and carbon nanotube, thus creating a new nanoscale electronic device. In addition, multilayer graphene with ultra-wide spectral absorption characteristics and unique photoelectric properties is an ideal material for photovoltaic devices. However, the zero band gap and semi-metality of graphene both limit its application in space detectors such as the microelectronic industries and satellites. Opening and regulating the graphene band gap by physical methods has become one of the key means to further expand its applications. Research work has shown that the doping of elements can significantly change the electronic structure of graphene, thereby regulating the optical properties of graphene. In order to provide an insight into electronic properties of graphene and tune its electronic band structure and optical properties effectively, electronic and optical properties of Ni-doped multi-layer graphene are studied and a number of interesting results are obtained. The calculation are carried out by the CASTEP tool in Materials Studio software based on the first-principles of ultrasoft pseudopotential of density functional theory. The models of three typical doping positions relative to carbon atoms are constructed. After structural optimization, it is obtained that " above the center of two carbon atoms” is the most stable doping structure. By using the method of local density approximation, the band structure, density of states, dielectric constant, reflectivity and refractive index of the models are calculated. The results show that an enhanced energy band gap can be achieved after nickel-doping, and reach up to 0.604 eV. Besides, peaked phenomenon of density of states at Femi level can be observed, which is accomplished by enhancing the plasma energy. Furthermore, the calculations show that the imaginary part of permittivity and refractive index increase after nickel-doping, suggesting that the optical absorbing performance is improved. All these results provide theoretical guidance for further exploring the optical properties of graphene.
Antireflection coatings based on subwavelength artificial engineering microstructures
Authors: Yao Yao , Shen Yue , Hao Jia-Ming , Dai Ning ,   School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China,   State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Published: December 2020

When light passes through an interface between two media with different refractive indices, part of light energy is reflected and thus causes an inevitable optical reflection. Optical anti-reflection is of great importance for applications in a wide range such as solar cells, optical lenses, infrared sensors, and photo-detectors, which has long been a research topic in the fields of optical systems and optoelectronic devices. In this article, the recent research progress of the optical anti-reflection based on subwavelength artificial engineering materials is reviewed. Having made a brief review of conventional anti-reflection methods, we focus on the overview of the newly developed techniques for optical anti-reflection, such as eliminating reflection by exciting the localized surface plasmons, the enhancement of transmission induced by the excitation of propagating surface plasmons, making metals transparent by the help of metamaterials, and the reduction of anti-reflection in long wavelength infrared and terahertz spectral ranges by using metasurfaces. Compared with the conventional anti-reflection methods, the new technique usually does not suffer the limitation of material, and it benefits from enhanced light absorption and wide incidence angle response. The new technique also enables the design of anti-reflection over wide or a multiple wavelength band. Finally, the future opportunities and challenges for further developing the subwavelength artificial engineering microstructures in optical anti-reflection are also predicted.
Modeling and simulation of following behaviors of pedestrians under limited visibility
Authors: Yang Can , Chen Qun , Chen Lu ,   Traffic and Transportation Engineering, Central South University, Changsha 410075, China
Published: December 2020

In order to investigate the following behaviors of pedestrians under limited visibility, pedestrian evacuation is simulated by an improved cellular automata model. Considering the familiarity of pedestrians with the environment, pedestrians are divided into two types: Informed type and uninformed type. For the informed pedestrians, an extended cost potential field cellular automata model is proposed. For the uninformed pedestrians, some following behavior strategies are suggested to study their evacuation behaviors. These following behaviors include following a pedestrian in the visibility (S1), following the most people’s position in the visibility (S2), following the most movement direction in the visibility (S3), and walking along the wall (S4). To investigate the evacuation efficiency of these different following strategies, we compare the performances of different densities of informed pedestrians, different visibility and different pedestrian proportions. As demonstrated by the simulation results, evacuation efficiency and the effectiveness of the following strategies are related to the visibility and density of informed pedestrians. The simulation results show that when the density of informed pedestrians is constant, S4 is more efficient at very poor visibility (R = 1), strategy S3 and S4 are more efficient at poor visibility (1 < R < 7), and the four strategies are equally efficient at good visibility (R > 6). In addition, when the visibility is constant, the density of informed pedestrians is less than 0.5, strategy S3 is the most efficient strategy. When the visibility is constant, the density of informed pedestrians is more than 0.5, the four strategies have a better performance. Moreover, it is noted that the same regular changes also exist in a single strategy environment. These findings can provide some insights into the emergency evacuation of large public places such as supermarkets and stadiums, and help develop effective guidance strategies under limited visibility.
High sensitivity terahertz refractive index sensor based on sunflower-shaped circular photonic crystal
Authors: Yan De-Xian , Li Jiu-Sheng , Wang Yi ,   Centre for THz Research, China Jiliang University, Hangzhou 310018, China,   Key Laboratory of Electromagnetic Wave Information Technology and Metrology of Zhejiang Province, College of Information Engineering, China Jiliang University, Hangzhou 310018, China
Published: December 2020

Refractive index sensing is attracting extensive attention in biochemical sensing using terahertz technology. Various structures with strong confinements have been used to design sensors for improving the interaction between the terahertz wave field and the analytes, such as photonic crystals, nanowires, plasmonic structures, and metamaterials. Terahertz wave sensors based on two-dimensional photonic crystal have been used in various areas ranging from disease diagnostics to environmental pollution detection. For improving the performance of terahertz sensor, a sensing scheme based on high-density polyethylene sunflower-typecircular photonic crystal structure is proposed. The designed sensor contains two symmetrical sample cells surrounding a cavity in a circular photonic crystal. The transmission properties of the terahertz wave sensor are analyzed based on COMSOL Multiphysics when the central sample cells are filled with analyte with different refractive indices. The sensor characteristics depending on the structure parameters are analyzed. The choice of these parameters is discussed. Finally, a sensitivity of 10.4 μm/RIU, Q-factor of 62.21, and figure-of-merit of 1.46 are realized. The results in this work are expected to be able to extend the circular photonic crystal-based sensor to terahertz wave region.
Digital holographic microscopy for red blood cell imaging
Authors: Zhang Yi-Yi , Wu Jia-Chen , Hao Ran , Jin Shang-Zhong , Cao Liang-Cai ,   College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018, China,   Key Laboratory of Zhejiang Province on Modern Measurement Technology and Instruments, Hangzhou 310018, China,   State Key Laboratory of Precision Measurement Technology and Instruments, Tsinghua University, Beijing 100084, China
Published: December 2020

Digital holographic microscopy (DHM) can obtain biological parameters and morphological information of cells by reconstructing holograms, which is different from traditional optical microscopy. The DHM is a three-dimensional imaging technology which is effective, non-contact and non-destructive. With the developments of the image sensor and the computing technology, it has made significant progress in the field of living cells detection, especially for red blood cell. Compared with the technologies which are widely used in the field of cell imaging such as con-focal laser scanning microscopy, scanning near-field optical microscopy and optical coherence tomography, the DHM has the advantages including wide FOV and high-resolution to achieve higher imaging and quality. This paper introduces the principle of recording and reconstruction of digital holography, and then analyzes the performance of three reconstruction algorithms using the Fresnel method, the convolution method and the angular spectrum method. The Fresnel method is suitable for the sample size larger than the image sensor. Both the convolution method and the angular spectrum method have an optimal reconstruction distance. When the reconstruction distance is different from the optimal distance, the resolution of the reconstructed image will decrease, and the angular spectrum method is better than the convolution method in overall performance. The DHM system for RBC measurements mainly adopts the convolution algorithm or the angular spectrum algorithm to implement numerical reconstruction. The systems of the in-line DHM, the off-axis DHM and the optical tweezers combining with off-axis DHM are introduced. These techniques use algorithms including Rayleigh-Sommerfeld back-propagation, the sharpness quantification, the watershed segmentation, the numerical refocusing and the thermal fluctuation to determine the focal plane position and obtain the best reconstruction distance of the RBCs, and further detect the shape change of the RBCs and extract the information of high-resolution blood vessel shape and blood flow velocity. These techniques can even achieve the dynamic tracking and measure three-dimensional volume of RBCs in real-time which is helpful for pathological studies such as diabetes, cardiovascular disease and Parkinson's disease. With its unique non-contact and non-destructive characteristics, the DHM realizes real-time and quantitative detection that is difficult to achieve with traditional three-dimensional microscopic imaging technologies.
Non-abelian statistics of Majorana modes and the applications to topological quantum computation
Authors: He Ying-Ping , Hong Jian-Song , Liu Xiong-Jun ,   International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China,   Collaborative Innovation Center of Quantum Matter, Beijing 100871, China,   Beijing Academy of Quantum Information Science, Beijing 100193, China,   CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
Published: December 2020

Since their prediction as fundamental particles in 1937, Majorana fermions have drawn lots of interests in particle physics and dark matter. Their counterparts in condensed matter physics, Majorana zero-Modes (MZMs), have attracted remarkable attention in condensed matter for their potential in building a fault-tolerant quantum computer. Due to the relentless effort, lots of important progress has been made in Majorana physics in the past two decades, as introduced in several excellent review articles. This review focuses on the non-Abelian statistics of MZMs and their application to quantum computation. In the first section of this work, the theoretical progress in searching for MZM is briefly reviewed and the latest experimental progresses are summarized. We next introduce the basic concepts of non-Abelian statistics of MZMs and explain how they can be applied to quantum computation. We then discuss two key experiments to implementing quantum computers in the MZM platform: MZM braiding and MZM qubit readout. In this part, several representative proposals for the Majorana braiding and MZM qubit readout are elaborated. Finally, we introduce a latest concept, the symmetry-protected non-Abelian braiding of Majorana Kramers pairs in time-reversal invariant topological superconductors.
Triboelectric nanogenerator based wearable energy harvesting devices
Authors: Ding Ya-Fei , Chen Xiang-Yu ,   CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China,   School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

With the miniaturization and functionalization of electronic devices, wearable electronics has drawn generally attention, but the energy supply for wearable electronics becomes one of the most burning questions. The triboelectric nanogenerator based on the coupling effects of electrostatic induction and triboelectrification, which has low cost and wide material selection attributes, proves to be a powerful technology for converting low-frequency mechanical energy into electricity. In this review, the four fundamental modes of triboelectric nanogenerator and the physical mechanism of contact-electrification are presented first. Then, we introduce the research progress of wearable from the direct and indirect aspects. Directly wearable triboelectric nanogenerator can be integrated into a skin while indirectly wearable device is only allowed to assemble into user’s clothing or its appendages. In addition, the power management circuits for driving electronic devices and energy storage are summarized. Finally, we discuss the current bottlenecks and present our perspectives on future directions in this field.
Cortical encoding of acoustic and linguistic rhythms in spoken narratives
Authors: Luo Cheng , Ding Nai
Published: December 2020

Speech contains rich acoustic and linguistic information. Using highly controlled speech materials, previous studies have demonstrated that cortical activity is synchronous to the rhythms of perceived linguistic units, for example, words and phrases, on top of basic acoustic features, for example, the speech envelope. When listening to natural speech, it remains unclear, however, how cortical activity jointly encodes acoustic and linguistic information. Here we investigate the neural encoding of words using electroencephalography and observe neural activity synchronous to multi-syllabic words when participants naturally listen to narratives. An amplitude modulation (AM) cue for word rhythm enhances the word-level response, but the effect is only observed during passive listening. Furthermore, words and the AM cue are encoded by spatially separable neural responses that are differentially modulated by attention. These results suggest that bottom-up acoustic cues and top-down linguistic knowledge separately contribute to cortical encoding of linguistic units in spoken narratives.
SlitC-PlexinA1 mediates iterative inhibition for orderly passage of spinal commissural axons through the floor plate
Authors: Ducuing Hugo , Gardette Thibault , Pignata Aurora , Kindbeiter Karine , Bozon Muriel , Thoumine Olivier , Delloye-Bourgeois Céline , Tauszig-Delamasure Servane , Castellani Valerie
Published: December 2020

Spinal commissural axon navigation across the midline in the floor plate requires repulsive forces from local Slit repellents. The long-held view is that Slits push growth cones forward and prevent them from turning back once they became sensitized to these cues after midline crossing. We analyzed with fluorescent reporters Slits distribution and FP glia morphology. We observed clusters of Slit-N and Slit-C fragments decorating a complex architecture of glial basal process ramifications. We found that PC2 proprotein convertase activity contributes to this pattern of ligands. Next, we studied Slit-C acting via PlexinA1 receptor shared with another FP repellent, the Semaphorin3B, through generation of a mouse model baring PlexinA1Y1815Fmutation abrogating SlitC but not Sema3B responsiveness, manipulations in the chicken embryo, and ex vivo live imaging. This revealed a guidance mechanism by which SlitC constantly limits growth cone exploration, imposing ordered and forward-directed progression through aligned corridors formed by FP basal ramifications.
Full-length genome characterization and phylogenetic analysis of SARS-CoV-2 virus strains from Yogyakarta and Central Java, Indonesia
Authors: Gunadi  , Wibawa Hendra , Marcellus  , Hakim Mohamad Saifudin , Daniwijaya Edwin Widyanto , Rizki Ludhang Pradipta , Supriyati Endah , Nugrahaningsih Dwi Aris Agung , Afiahayati  , Siswanto  , Iskandar Kristy , Anggorowati Nungki , Kalim Alvin Santoso , Puspitarani Dyah Ayu , Athollah Kemala , Arguni Eggi , Nuryastuti Titik , Wibawa Tri
Published: December 2020

Background

Recently, SARS-CoV-2 virus with the D614G mutation has become a public concern due to rapid dissemination of this variant across many countries. Our study aims were (1) to report full-length genome sequences of SARS-CoV-2 collected from four COVID-19 patients in the Special Region of Yogyakarta and Central Java provinces, Indonesia; (2) to compare the clade distribution of full-length genome sequences from Indonesia (n = 60) from March to September 2020 and (3) to perform phylogenetic analysis of SARS-CoV-2 complete genomes from different countries, including Indonesia.

Methods

Whole genome sequencing (WGS) was performed using next-generation sequencing (NGS) applied in the Illumina MiSeq instrument. Full-length virus genomes were annotated using the reference genome of hCoV-19/Wuhan/Hu-1/2019 (NC_045512.2) and then visualized in UGENE v. 1.30. For phylogenetic analysis, a dataset of 88 available SARS-CoV-2 complete genomes from different countries, including Indonesia, was retrieved from GISAID.

Results

All patients were hospitalized with various severities of COVID-19. Phylogenetic analysis revealed that one and three virus samples belong to clade L and GH. These three clade GH virus samples (EPI_ISL_525492, EPI_ISL_516800 and EPI_ISL_516829) were not only located in a cluster with SARS-CoV-2 genomes from Asia but also those from Europe, whereas the clade L virus sample (EPI_ISL_516806) was located amongst SARS-CoV-2 genomes from Asia. Using full-length sequences available in the GISAID EpiCoV Database, 39 of 60 SARS-CoV-2 (65%) from Indonesia harbor the D614G mutation.

Conclusion

These findings indicate that SARS-CoV-2 with the D614G mutation appears to become the major circulating virus in Indonesia, concurrent with the COVID-19 situation worldwide.
An In-vitro Assessment of Effect of Interaction Between Local Anaesthetic Solution with Sodium Hypochlorite on the Sealing Ability of Root Canal Obturation
Authors: Chauhan Urmila Banshbahadur , Mangala Tipturmanjunath , Mahaparale Rushikesh , Saraf Adish , Mali Sneha , Pawar Sagar , Dsouza Vincia , Mandhane Shubham
Published: December 2020

Introduction: Endodontic treatment failures are caused by persistent or secondary infection due to inefficient cleaning or re-infection of the obturated root canal system because of coronal or apical leakage. Intrapulpal Injection (IPI) technique is the most commonly employed supplemental anaesthetic procedure and NaOCl is considered as gold standard irrigating solution. Therefore, this study was designed to explore the action of precipitate form by interaction between LA and Sodium Hypochlorite (NaOCL) on sealing of root canal obturating material. Aim: To evaluate the effect of precipitate formed by interaction of local anaesthetic solution and NaOCl on the sealing ability of root canal obturation, using a push-out bond strength test. Materials and Methods: This was an in-vitro study from October 2019 to January 2020. In this study, forty single rooted premolars were selected and were randomly distributed equally into 4 groups with 10 specimens in each group, based on the test solutions employed. All the teeth were decoronated and the root length was standardised. Group I - irrigated with saline only, Group II- treated with 2% lidocaine hydrochloride with adrenaline 1:100,000 (2% LA) followed by 3% NaOCl, Group III - 2% LA followed by saline and 3% NaOCl, Group IV- 3% NaOCl followed by saline. All root canals were than instrumented using ProTaper Universal rotary system upto F3 and obturation was done using AH plus sealer and GuttaPercha. Sealing ability was evaluated using a micro push-out bond strength, with the help of a universal testing machine and data were analysed statistically. Results: One-way analysis of variance (ANOVA) showed that there is highly significant difference among the various groups (p <0.0001). Within the experimental groups, Group II showed minimum mean push out bond strength (16.39±2.40) as compared to Group III (21.83±1.25) and Group IV (22.50±2.12). Conclusion: Interaction of LA with NaOCl forms precipitate which blocks the dentinal tubules and reduces the mean push out bond strength. It is recommended to irrigate thoroughly with saline after intrapulpal injection (2%LA) before irrigating with NaOCl.
Intermittent Subcutaneous Morphine for Postoperative Analgesia Following Coronary Artery Bypass Grafting
Authors: Namitha CN , Kamath Manjunath R , Bangera Ananda , Krishnan M Gopala , Kiran B Amith
Published: December 2020

Introduction: An effective postoperative pain management is of utmost importance following cardiac surgery. Various agents, routes and modes are available for the treatment of postoperative pain. Subcutaneous route of administration is an easy and effective method of postoperative analgesia with improved patient satisfaction and lesser side effects compared to intravenous route. Aim: To evaluate the efficacy of Subcutaneous Morphine (SCM) as postoperative analgesia following Coronary Artery Bypass Grafting (CABG). Materials and Methods: This study was designed as a retrospective analytical survey from June 2015 to June 2017. Medical records of all patients over 18 years of age who underwent coronary artery bypass grafting were reviewed. Patients belonging to ASA PS I, II and III, patients above 18 years of age and those posted for coronary artery bypass grafting were included in the study. Patients were divided into two groups: SCM group and Paracetamol (PCT) group, depending on the primary analgesia they received. The two groups were compared using Student’s t-test for normally distributed continuous data or non-parametric tests if the data were not normally distributed. Categorical data were compared by Fisher’s-exact test. The p-values <0.05 were considered statistically significant. Results: A total of 102 records were reviewed, out of which 49 patients received SCM and 53 patients had received PCT as their primary postoperative analgesia. It was observed that PCT group required more additional analgesia (intravenous fentanyl/ tramadol) than SCM group which was statistically significant with p-value of <0.001 and the duration of Cardiac Intensive Care Unit (CICU) stay was more in PCT group with p-value of 0.001. Postoperative side effects were significantly more in PCT group. Conclusion: SCM can be effectively administered intermittently for postoperative analgesia following CABG with similar haemodynamic stability and minimal side effects as compared to intermittent intravenous PCT.
Endodontic Management of a Tooth with Severe External Root Resorption using Injected Non-setting Calcium Hydroxide Paste: A Case Report
Authors: Guedes Orlando Aguirre , Henrique Tiago Luan , Zayek Pollyana Sousa Lôbo El , Aranha Andreza Maria Fábio , Oliveira Helder Fernandes De
Published: December 2020

External Root Resorption (ERR) is a pathological condition that can lead to tooth loss if not diagnosed and treated correctly. Calcium Hydroxide Ca(OH)2 is an intracanal medicament, which is used in cases of teeth with pulp necrosis, peri-radicular lesions and ERR. This paper describes the endodontic management of a tooth with severe ERR using injected non-setting Ca(OH)2 paste. A 28-year-old patient was referred for endodontic evaluation of tooth 47, which presented an extensive composite resin restoration and was negative to cold test. Panoramic and periapical radiographs revealed the presence of a filled pulp chamber, calcified root canals, ERR on the mesial and distal roots, and apical periodontitis in the mesial and distal roots. The diagnosis of asymptomatic apical periodontitis and severe ERR was established, and conventional root canal treatment combined with non-setting Ca(OH)2dressing was chosen. After five months, no more discharge from the root canal was observed, and a decrease in the size of the periapical lesion and arrest of ERR was detected. The root canal was filled, and the patient was referred for restoration. At the 6-months follow-up, radiographic examination evidenced periapical repair and containment of the ERR process. Chemomechanical root preparation in association with a non-setting Ca(OH)2 dressing protocol allows positive outcomes during the management of severe ERR associated with pulp necrosis and periapical inflammation.
Study of Glycation of Transferrin and its Effect on Biomarkers of Iron Status in Uncontrolled Diabetes Mellitus Patients
Authors: Sabitha Dunna , Dawson E Manasvi , Tiwari Shashank Nand Krishna , Swetha P , Naushad Shaik Mohammad , Baba KSS Sai , Mohan Iyyapu Krishna , Rani Ganni Usha
Published: December 2020

Introduction: Diabetes Mellitus (DM) is a metabolic condition linked by the inability to produce enough insulin and/or to respond to insulin. This can lead to a number of acute and chronic health problems. In erythrocytes, transferrin is the main source of iron. Alterations in transferrin glycation affect transferrin saturation because the affinity of transferrin for Fe3+ is extremely high but it decreases progressively with increasing glycation. Aim: To investigate the influence of uncontrolled diabetes on transferrin glycation and iron metabolism. Materials and Methods: A total of 136 samples from 3 groups of HbA1c levels (<6.0% non-diabetic, 6.4-8% diabetic, >8.0%-uncontrolled DM) were studied for the correlation pattern of iron with other variables. Chi square test and student’s t-test were performed to reveal the association between serum free iron levels and other variables with DM. Results: Serum iron has shown to be depleted significantly (p=0.02) along with percentage saturation (p=0.0006) with increase in diabetic severity. No significant differences were observed in serum ferritin in controlled DM and uncontrolled samples. Total Iron Binding Capacity (TIBC) was found to be significantly increased in uncontrolled DM samples (p=0.01). Abnormal transferrin was observed uncontrolled diabetes with subsequent depletion in transferrin, which in turn results in low serum iron, lower percentage saturation and high TIBC. Conclusion: Uncontrolled diabetes affects the glycation of transferrin also thus perturbating iron metabolism. The present study emphasises the need to monitor transferrin glycation status and iron deficiency anaemia in subjects with uncontrolled diabetes.
Straw, Seed Yield and Quality of Three Linum usitatissimum L. Cultivars in Relation to Nitrogen Fertilizer Rate and Plant Density
Authors: Gedwy El-Saeed M. M. El- , Hammam Gaber Y. M. , Allam Salah A. H. , Mostafa Saber H. A. , Shimy Khaled S. S. El-
Published: December 2020

Methodology: Two field experiments were conducted on the Experimental Farm at El-Gemmeiza Research Station, Gharbia Governorate, Agricultural Research Center, Egypt, during two successive winter seasons of 2018-19 and 2019-20.

Aims: To investigate the effect of three nitrogen fertilizer rates, i.e. 30, 50 and 70 kg N feddan-1 [one feddan (fed) = 4200 m2] and three plant densities, i.e. 1500, 2000 and 2500 seeds m-2 on flax (Linum usitatissimum L.) yield and its quality of three cultivars of flax, i.e. Sakha 3, Giza 11 and Giza 12.

Results: Results in combined analysis of the two seasons showed that Sakha 3 cultivar significantly produced the maximum total plant height, technical stem length, upper branching zone length, No. of seeds capsule-1, total fiber percentage, fiber yield plant-1, fiber yield fed-1, fiber length and fiber fineness. Meanwhile, the highest No. of basal branches plant-1, straw yield plant-1, straw yield fed-1 and seed oil content were recorded with Giza 12 cultivar. While, Giza 11 cultivar gave the maximum stem diameter, No. of upper branches plant-1, No. of capsules plant-1, No. of seeds plant-1, seed index, seed yield plant-1, seed yield fed-1, harvest index, oil yield plant-1 and oil yield fed-1. Increasing nitrogen fertilizer rates from 30 up to 70 kg N fed-1 caused significant increases in almost straw, fiber, seed and oil yields and its related traits of flax, on the other hand, fiber fineness which significantly decreased with increasing nitrogen rates. Flax plants growing at 1500 seeds m-2 markedly gave the greatest No. of basal branches plant-1, stem diameter, straw yield plant-1, upper branching zone length, No. of upper branches plant-1, No. of capsules plant-1, No. of seeds plant-1, seed yield plant-1, harvest index, oil yield plant-1 and fiber yield plant-1. Meanwhile, the maximum total plant height, technical stem length, straw yield fed-1, seed yield fed-1, oil yield fed-1, total fiber percentage, fiber yield fed-1, fiber length and fiber fineness were obtained from flax planting at 2500 seeds m-2. The maximum fiber yield were recorded from the interactions among treatments Sakha 3 X 70 kg N fed-1, Sakha 3 X 2500 seeds m-2, 70 kg N fed-1 X 2500 seeds m-2 and Sakha 3 X 70 kg N fed-1 X 2500 seeds m-2. Meanwhile, the maximum seed and oil yields fed-1 were recorded from the interactions between treatments Giza 11 X 70 kg N fed-1, Giza 11 X 2500 seeds m-2, 70 kg N fed-1 X 2500 seeds m-2 and Giza 11 X 70 kg N fed-1 X 2500 seeds m-2.

Generally, it could be concluded that Sakha 3 cultivar under soil fertilized by 70 kg N fed-1 with plant density of 2500 seeds m-2 to maximizing fiber yield fed-1, while Giza 11 cultivar with the same rates of nitrogen and plant density to maximizing seed and oil yields fed-1.
Production and Optimization of Biosurfactants from Citrullus lanatus Seeds and Activity Determination with Pseudomonas aeruginosa Isolate
Authors: Ukwueze T. O. , Ozougwu V. E. O. , Njoku O. U. , Haruna G. S.
Published: December 2020

Aims: To produce and optimize biosurfactants from Citrullus lanatus seeds.

Study Design: Randomized design.

Place and Duration of Study: Department of Biochemistry Lab. and Department of Microbiology lab. University of Nigeria, Nsukka, between April and August, 2017.

Methodology: Biosurfactants were produced in two fermentation media consisting of basal mineral medium+ watermelon (C. lanatus) seed (BMM+WMS), and Nutrient broth (NB). Optimization of production process was carried out with respect to time/duration of fermentation and pH of production which indicated 7 days fermentation period at pH 8.0. The Pseudomonas aeruginosa used was isolated from soil. The biosurfactants stability under some environmental conditions were studied using; Thermostability test at 30°C, 60°C, and 100°C; Halostability test with %w/v concentration of NaCl in; 2%NaCl, 5%NaCl, 7%NaCl, and 10%NaCl; pH stability test was conducted with pH 2.0, pH 4.0, pH 6.0, pH 8.0, pH 10.0, and pH 12.0.

Results: Proximate analysis(%) showed; protein (0.317­ ± 0.02), lipid (17.66 ± 0.17), carbohydrate (62.77 ± 0.21), ash (2.33 ± 0.24), fibre (4.84 ± 0.79), and moisture (12.06 ± 0.17).The Emulsification index (E24) for the crude biosurfactant solutions (supernatants) that resulted from the two production media, and sodium dodecyl sulfate 1% SDS in distilled water (control) using palm oil (PO), olive oil (OO), engine oil (EO), kerosene (KR), and petrol (PT) for BMM+WMS biosurfactant gave  PO (79.66±1.52%), OO (64.66±7.23%), EO (15.33±4.93%), KR (12.66±6.50%), and PT (0.00±0.00%). Also, the NB biosurfactant resulted in; PO (71.00±2.00), OO (54.33±3.78), EO (42.66±6.42), KR (22.66±7.57), and PT (0.00 ± 0.00) E24 values. There were significant decreases (p<0.05) in biosurfactants activities in all vegetable oils and hydrocarbons when compared to the SDS surfactant. However, there was no significant decrease (p>0.05) in WMS biosurfactant activity in palm oil compared to SDS surfactant activity in palm oil.

Conclusion: The biosurfactants were shown to have high thermostablity as their E24 values increased with rise in temperature.