bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying discrete seismic responses to mining
Authors: Brown L.G.
Published: September 2020

Applying analysis techniques developed for naturally occurring earthquakes to mine seismicity is common practice; however, these methodologies rarely consider the influence of blasting on the dynamic rock mass failure processes observed in mines. Due to the complex nature of bulk orebody extraction at depth, quantifying discrete seismic responses to mining can be challenging. This paper identifies seismic responses to mining by pairing single-link clustering with finite temporal windows bound by mine blasting practices. A methodology is presented to quantify the space−time characteristics of these responses using four seismic response parameters (SRPs): distance to blast, distance to centroid, time after blast, and time between events. Using SRPs, seismic responses to mining can be quantitatively classified as induced, complex, or triggered (with respect to discrete mine blasting). Because these response parameters do not require an extensive and (or) triaxial dense sensor array, they are applicable to a variety of underground mining operations. In this work, SRPs are applied to 189 discrete seismic responses occurring over 2 months of active mining, and a 2 week shutdown period, at Agnico Eagle’s LaRonde Mine.
The dynamics of spatially confined oscillations
Authors: Stadtler Till , Kroupa Pavel , Schmid Manfred
Published: September 2020

The possible relation of the wave nature of particles to gravitation as an emergent phenomenon is addressed. Hypothetical particles are considered as spatially confined oscillations (SCOs) and are constructed through the superposition of plane waves. The effect of a continuously changing refractive index (speed of propagation field) on SCOs is calculated and the continuous Ibn–Sahl–Snell law of refraction is derived. Refracted plane wave constituents of SCOs in an inhomogeneous medium cause the oscillation as a whole to accelerate as an entity. This acceleration is described by a geodesic equation, in much the same way as in general relativity. The proper time of an SCO can be defined via its oscillation frequency. The proper time and its change along the trajectory are equivalent to a particle in general relativity as described by the 0th component of its geodesic equation. An SCO in an inhomogeneous refractive index field exhibits general relativistic properties based on basic wave mechanics. Properties derived from direct calculations are length contraction, gravitational red- and blueshift, and Thomas precession. The presented theory is an approximation for oscillations which are small compared to changes in the refractive index field. SCOs in an inhomogeneous medium may thus yield a naturally emerging particle-field interaction with general relativistic properties and may allow a useful vantage point on the nature of gravitation using classical wave experiments.
The counting of Nambu–Goldstone bosons in a non-Hermitian field theory
Authors: Arraut Ivan
Published: September 2020

We demonstrate that the number of Nambu–Goldstone bosons is always equal to the number of conserved currents inside the scenario of non-Hermitian field theories with spontaneous symmetry breaking. This eliminates the redundancies which normally appears in Hermitian field theories, specifically when the Lagrangian under analysis violates explicitly the Lorentz symmetry.
Latest results of the LUX dark matter experiment
Authors: Woodward David
Published: September 2020

LUX (Large Underground Xenon) was a dark matter experiment, which was housed at the Sanford Underground Research Facility (SURF) in South Dakota until late 2016, and previously set world-leading limits on Weakly Interacting Massive Particles (WIMPs), axions and axion-like particles (ALPs). This proceeding presents an overview of the LUX experiment and discusses the most recent analysis efforts, which are probing various dark matter models and detection techniques. In particular, studies of signals from inelastic scattering processes and of single scintillation photon events have improved the sensitivity of the experiment to low mass WIMPs. Additionally, a model-independent search for modulations in the LUX electron recoil rate is presented, demonstrating the most sensitive annual modulation search to date.
New solid-state organic scintillators for fast and thermal neutron detection
Authors: Zaitseva N. , Glenn A. , Mabe A. , Carman L. , Payne S.
Published: September 2020

Detection of special nuclear materials (SNM) requires instruments that can detect and characterize uranium and plutonium isotopes, having at the same time the ability to discriminate among different types of radiation. For many decades, neutron detection has been based on 3He proportional counters sensitive primarily to thermal neutrons. The most common methods for detection of fast neutrons have been based on liquid scintillators with pulse shape discrimination (PSD). The shortage of 3He and handling issues with liquid scintillators stimulated a search for efficient solid-state PSD materials. Recent studies conducted at LLNL led to development of new materials, among which are organic crystals with excellent PSD and first PSD plastics for fast neutron detection. More advantages are introduced by plastics doped with neutron capture agents, such as 10B and 6Li, that can be used without moderation for combined detection of both thermal and fast neutrons, offering, in addition, a unique “triple” PSD for signal separation between fast neutrons, thermal neutrons, and gamma-rays. More recent studies have been focused on development of deuterated scintillators that can be used for neutron spectroscopy without time-of-flight (ToF). Among commercially produced materials are large-scale (>10 cm) stilbene crystals grown by the inexpensive solution technique, and different types of PSD plastics that, due to the deployment advantages and ease of fabrication, create a basis for the widespread use of solid-state scintillators as large-volume and low-cost neutron detectors.
Nuclear fission investigation with twin ionization chamber
Authors: Zeinalov Sh. , Sedyshev P. , Sidorova O. , Shvetsov V.
Published: September 2020

In this paper, we report recent results obtained in the development of digital pulse processing mathematics for prompt fission neutron (PFN) investigations using a twin ionization chamber (TIC) along with a fast neutron time-of-flight detector (ND). Due to some ambiguities in the literature concerning a pulse induction on TIC electrodes by fission fragment (FF) ionization, we first presented a detailed mathematical analysis of FF signal formation on the TIC anode. The analysis was done using the Shockley–Ramo theorem, which gives the relation between charged particle motion between TIC electrodes and the so-called weighting potential. The weighting potential was calculated by direct numerical solution of the Laplace equation (neglecting space charge) for the TIC geometry and ionization caused by FFs. Formulae for GI correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and used in experiments for PFN investigations of two reactions, [Formula: see text]U(n[Formula: see text],f) and [Formula: see text]Cf(sf). Results of the measurements were compared to literature data to demonstrate the feasibility of the new developed techniques. These results were necessary for the development of a new PFN investigation facility consisting of a position sensitive fission fragment detector combined with 32 liquid scintillation neutron detectors.
Neutron transmission studies for concrete used in the nuclear industry
Authors: Buffler A , Hutton T. , Leadbeater T. , Alexander M. , Dlamini S.
Published: September 2020

Progress in the establishment of a fast neutron beam reference facility for the non-destructive testing of concrete and other materials used in the nuclear industry is described. An additional area of interest is the development of methods for the independent verification of the alignment to regulatory codes of the constituent materials used in concrete mixes for nuclear facilities, both existing and planned. The project is based on the principle of analyzing the distributions in energy of the neutrons transmitted through the sample. Modern methods of spectrum unfolding allow such analyses to be undertaken without the need for the neutron beam to be ns-pulsed in order to measure neutron energies by time-of-flight. First measurements and analyses of mortar (concrete without large aggregate) using continuous beams of fast neutrons are presented.
A Numerical Approach for Calculation of Characteristics of Edge Waves in Three-Dimensional Plates
Authors: Duan Wenbo , Kirby Ray
Published: September 2020

Surface waves have been extensively studied in earthquake seismology. Surface waves are trapped near an infinitely large surface. The displacements decay exponentially with depth. These waves are also named Rayleigh and Love waves. Surface waves are also used for nondestructive testing of surface defects. Similar waves exist in finite width three-dimensional plates. In this case, displacements are no longer constant in the direction perpendicular to the wave propagation plane. Wave energy could still be trapped near the edge of the three-dimensional plate, and hence the term edge waves. These waves are thus different to the two-dimensional Rayleigh and Love waves. This paper presents a numerical model to study dispersion properties of edge waves in plates. A two-dimensional semi-analytical finite element method is developed, and the problem is closed by a perfectly matched layer adjacent to the edge. The numerical model is validated by comparing with available analytical and numerical solutions in the literature. On this basis, higher order edge waves and mode shapes are presented for a three-dimensional plate. The characteristics of the presented edge wave modes could be used in nondestructive testing applications.
Natural and Anthropogenic Drivers of Acidification in Large Estuaries
Authors: Cai Wei-Jun , Feely Richard A. , Testa Jeremy M. , Li Ming , Evans Wiley , Alin Simone R. , Xu Yuan-Yuan , Pelletier Greg , Ahmed Anise , Greeley Dana J. , Newton Jan A. , Bednaršek Nina
Published: September 2020

Oceanic uptake of anthropogenic carbon dioxide (CO2) from the atmosphere has changed ocean biogeochemistry and threatened the health of organisms through a process known as ocean acidification (OA). Such large-scale changes affect ecosystem functions and can have impacts on societal uses, fisheries resources, and economies. In many large estuaries, anthropogenic CO2-induced acidification is enhanced by strong stratification, long water residence times, eutrophication, and a weak acid–base buffer capacity. In this article, we review how a variety of processes influence aquatic acid–base properties in estuarine waters, including coastal upwelling, river–ocean mixing, air–water gas exchange, biological production and subsequent aerobic and anaerobic respiration, calcium carbonate (CaCO3) dissolution, and benthic inputs. We emphasize the spatial and temporal dynamics of partial pressure of CO2 ( pCO2), pH, and calcium carbonate mineral saturation states. Examples from three large estuaries—Chesapeake Bay, the Salish Sea, and Prince William Sound—are used to illustrate how natural and anthropogenic processes and climate change may manifest differently across estuaries, as well as the biological implications of OA on coastal calcifiers.
PhysioArt: a teaching tool to motivate students to learn physiology
Authors: Flôr Atalia Ferreira Lima , Fernandes Costa Francineide , Lima Garcia João Marcos , Braga Valdir A. , Cruz Josiane Campos
Published: September 2020

Learning physiology is challenging for students. The nature of the discipline, which includes many complex mechanisms, makes the subject complicated. Furthermore, the length of the textbooks and the usual multiple-choice tests, which prioritize memorizing instead of understanding, tend to discourage the students. Therefore, different pedagogical strategies have been adopted to motivate and facilitate the learning of physiology. In this sense, many pedagogical strategies have been using art as a tool to motivate and induce students to self-learn. Besides, art as a pedagogical tool has also been shown to be important in developing self-assurance, self-pride, as well as the development of critical-thinking skills in the students. Here, we incorporate a new practice of self-directed teaching and learning, which involves artwork interpretation in a physiological context. This extra-classroom activity integrating art and physiology (The PhysioArt Project) improved students’engagement, increasing their interest in the discipline by providing a more creative, pleasurable, and enthusiastic atmosphere for enjoying and learning physiology, which also has contributed to the development of creativity, critical thinking, and students’ self-assurance. Interestingly, the benefits elicited by The PhysioArt Project activities have also helped us to enhance the student-professor relationship, inducing a more humanized education.
Visualizing and quantifying cutaneous microvascular reactivity in humans by use of optical coherence tomography: impaired dilator function in diabetes
Authors: Argarini Raden , McLaughlin Robert A. , Joseph Simon Z. , Naylor Louise H. , Carter Howard H. , Haynes Andrew , Marsh Channa E. , Yeap Bu B. , Jansen Shirley J. , Green Daniel J.
Published: September 2020

The pathophysiology and time course of impairment in cutaneous microcirculatory function and structure remain poorly understood in people with diabetes, partly due to the lack of investigational tools capable of directly imaging and quantifying the microvasculature in vivo. We applied a new optical coherence tomography (OCT) technique, at rest and during reactive hyperemia (RH), to assess the skin microvasculature in people with diabetes with foot ulcers (DFU, n = 13), those with diabetes without ulcers (DNU, n = 9), and matched healthy controls (CON, n = 13). OCT images were obtained from the dorsal part of the foot at rest and following 5 min of local ischemia induced by inflating a cuff around the thigh at suprasystolic level (220 mmHg). One-way ANOVA was used to compare the OCT-derived parameters (diameter, speed, flow rate, and density) at rest and in response to RH, with repeated-measures two-way ANOVA performed to analyze main and interaction effects between groups. Data are means ± SD. At rest, microvascular diameter in the DFU (84.89 ± 14.84 µm) group was higher than CON (71.25 ± 7.6 µm, P = 0.012) and DNU (71.33 ± 12.04 µm, P = 0.019) group. Speed in DFU (65.56 ± 4.80 µm/s, P = 0.002) and DNU (63.22 ± 4.35 µm/s, P = 0.050) were higher than CON (59.58 ± 3.02 µm/s). Microvascular density in DFU (22.23 ± 13.8%) was higher than in CON (9.83 ± 2.94%, P = 0.008), but not than in the DNU group (14.8 ± 10.98%, P = 0.119). All OCT-derived parameters were significantly increased in response to RH in the CON group (all P < 0.01) and DNU group (all P < 0.05). Significant increase in the DFU group was observed in speed ( P = 0.031) and density ( P = 0.018). The change in density was lowest in the DFU group (44 ± 34.1%) compared with CON (199.2 ± 117.5%, P = 0.005) and DNU (148.1 ± 98.4, P = 0.054). This study proves that noninvasive OCT microvascular imaging is feasible in people with diabetes, provides powerful new physiological insights, and can distinguish between healthy individuals and patients with diabetes with distinct disease severity.
METTL3 contributes to renal ischemia-reperfusion injury by regulating Foxd1 methylation
Authors: Meng Fanhang , Liu Yongguang , Chen Qiuyuan , Ma Qing , Gu Shijie , Cui Ruiwen , Cao Ronghua , Zhao Ming
Published: September 2020

To investigate the mechanism of renal ischemia-reperfusion injury (IRI) via regulation of N6-methyl-adenosine (m6A) and relevant genes, IRI was induced in Sprague-Dawley rats, and urine and serum creatinine levels and tissue structure changes were observed. m6A and methyltransferase-like 3 (METTL3) protein levels were assessed via dot-blot and Western blot analyses, respectively. The hypoxia/reoxygenation (H/R) cell model was constructed using NRK-52E cells, and METTL3 protein levels were assessed. METTL3 was inhibited to observe its impact on NRK-52E cell apoptosis and m6A expression in H/R processes. Methylated RNA immunoprecipitation (MeRIP) sequencing was conducted followed by MeRIP-quantitative RT-PCR and quantitative RT-PCR validation. Our results indicated that urine and serum creatinine levels increased and that renal injury and cell apoptosis were both observed in the IRI model. In additon, m6A expression increased in the IRI model, and METTL3 protein levels significantly increased in the IRI and H/R models. When METTL3 was inhibited, m6A levels were accordingly decreased and cell apoptosis was suppressed in the H/R in vitro model. Based on MeRIP sequencing, transcription factor activating enhancer binding protein 2α ( tfap2a), cytochrome P-450 1B1 ( cyp1b1), and forkhead box D1 ( foxd1) were significantly differentially expressed, as was m6A, which is involved in the negative regulation of cell proliferation and kidney development. We confirmed that foxd1 mRNA and its methylation levels contributed to IRI and H/R.
Identification of key proteins involved in stickleback environmental adaptation with system-level analysis
Authors: Hall Martina , Kültz Dietmar , Almaas Eivind
Published: September 2020

Using abundance measurements of 1,490 proteins from four separate populations of three-spined sticklebacks, we implemented a system-level approach to correlate proteome dynamics with environmental salinity and temperature and the fish's population and morphotype. We identified robust and accurate fingerprints that classify environmental salinity, temperature, morphotype, and the population sample origin, observing that proteins with specific functions are enriched in these fingerprints. Highly apparent functions represented in all fingerprints include ion transport, proteostasis, growth, and immunity, suggesting that these functions are most diversified in populations inhabiting different environments. Applying a differential network approach, we analyzed the network of protein interactions that differs between populations. Looking at specific population combinations of differential interaction, we identify sets of connected proteins. We find that these sets and their corresponding enriched functions reflect key processes that have diverged between the four populations. Moreover, the extent of divergence, i.e., the number of enriched functions that differ between populations, is highest when all three environmental parameters are different between two populations. Key nodes in the differential interaction network signify functions that are also inherent in the fingerprints, most prominently proteostasis-related functions. However, the differential interaction network also reveals additional functions that have diverged between populations, notably cytoskeletal organization and morphogenesis. The strength of these analyses is that the results are purely data driven. With such an unbiased approach applied on a large proteomic data set, we find the strongest signals given by the data, making it possible to develop more discriminatory and complex biomarkers for specific contexts of interest.
The Bonding Mechanism and Experimental Verification of Pilger Hot Rolling Clad Tube
Authors: He Zonglin , Chu Zhibing , Shuang Yuanhua , Gou Yujun
Published: September 2020

In this paper, we focus on the bonding mechanism of bimetallic clad tube because of its low cost and comprehensive properties. The numerical simulation and the experiment are carried out from the diffusion behavior of carbon atoms in the metallurgical bonding process. Based on the dislocation density model of Kocks, the tube billets are rolled by pilger hot rolling; the outer tube is 06Cr19Ni10 stainless steel, the inner tube is Q235 carbon steel, and the wall thickness ratio is 1 : 1. The research shows that the diffusion ability of carbon atoms mainly depends on the degree of the plastic strain in the stainless steel hot rolling process; there is positive correlation between the thickness of bonding carburized layer and the dislocation density produced by plastic deformation of stainless steel. The thickness difference of circumferential carburized layer in the deformation zone is larger than that near the finishing zone. Furthermore, a lot of contaminants cannot be completely metallurgically bonded between 20% and 30% reduction ratios; the contaminants near the bonding layer are refined and completely bonded metallurgically between 30% and 60% reduction ratios; the contaminants are further refined above 60% to 70% reduction ratio.
Oxidative and Antioxidative Stress Linked Biomarkers in Ankylosing Spondylitis: A Systematic Review and Meta-analysis
Authors: Li Jiaxiao , Liu Suling , Cui Yang , Ray Sid D.
Published: September 2020

Objective. Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects the axial skeleton, leading to joint disability. Our study aims at investigating the change of oxidative and antioxidative stress linked biomarkers in AS. Methods. This systematic review and meta-analysis was performed following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, and Cochrane Library databases till May 2020 were searched. Only articles published in English were included. Two reviewers screened relevant studies, extracted data, and assessed the quality of included studies using the Newcastle-Ottawa scale independently. Either random or fixed effect model was adopted base on the heterogeneity testing by

I

2

statistic. Standardized mean difference (SMD) and 95% confidence intervals (CI) of oxidative and antioxidative markers were calculated.

p

value <0.05 was considered statistically significant. Results. A total of 22 studies including 931 AS patients and 917 healthy controls met the selection criteria. Significantly increased levels of all oxidative stress markers except myeloperoxidase, and significantly decreased levels of total antioxidant status (

SMD
=
−
1.19

, 95% CI -2.35 to -0.03,

p
=
0.044

) and paraoxonase 1(

SMD
=
−
1.01

, 95% CI -1.78 to -0.24,

p
=
0.010

) in serum were observed in AS patients when compared with healthy controls. However, there were no significant differences of all oxidative and anti-oxidative stress biomarkers in erythrocytes. Additionally, the levels of malondialdehyde (

SMD
=
0.51

, 95% CI 0.21 to 0.81,

p
=
0.001

) and advanced oxidation protein products (

SMD
=
0.95

, 95% CI 0.58 to 1.31,

p
<
0.001

) in serum were significantly higher in active patients when compared with inactive AS patients. Conclusion. This meta-analysis demonstrated an overall increase of oxidative markers and decrease of antioxidative markers in AS, suggesting that oxidative stress may play an important role in the pathogenesis of AS.
Profiling the Resident and Infiltrating Monocyte/Macrophages during Rejection following Kidney Transplantation
Authors: Wang Jie , Luo Peiling , Zhao Jingjie , Tan Junhua , Huang Feifan , Ma Ruiying , Huang Peng , Huang Meiying , Huang Yuming , Wei Qiuju , Wei Liuzhi , Wang Zechen , Meng Lingzhang
Published: September 2020

Immune tolerance research is essential for kidney transplantation. Other than antibody and T cell-mediated immune rejection, macrophage-mediated innate immunity plays an important role in the onset phase of transplantation rejection. However, due to the complexity of the kidney environment as well as its diversity and low abundance, studies pertaining to monocyte/macrophages in kidney transplantation require further elucidation. In this study, kidney samples taken from healthy human adults and biopsy specimens from patients undergoing rejection following kidney transplantation were analysed and studied. By conducting a single-cell RNA analysis, the type and status of monocyte/macrophages in kidney transplantation were described, in which monocyte/macrophages were observed to form two different subpopulations: resident and infiltrating monocyte/macrophages. Furthermore, previously defined genes were mapped to all monocyte/macrophage types in the kidney and enriched the differential genes of the two main subpopulations using gene expression databases. Considering that various cases of rejection may be of the monocyte/macrophage type, the present data may serve as a reference for studies regarding immune tolerance following kidney transplantation.
Subclinical Left Ventricular Systolic Dysfunction in Patients with Septic Shock Based on Sepsis-3 Definition: A Speckle-Tracking Echocardiography Study
Authors: Hai Pham Dang , Phuong Le Lan , Dung Nguyen Manh , Hoa Le Thi Viet , Quyen Do Van , Chinh Nguyen Xuan , Minh Vu Duy , Nguyen Son Pham
Published: September 2020

Introduction. Left ventricular dysfunction is quite common in septic shock. Speckle-tracking echocardiography (STE) is a novel, highly sensitive method for assessing left ventricular function, capable of detecting subclinical myocardial dysfunction, which is not identified with conventional echocardiography. We sought to evaluate subclinical left ventricular systolic function in patients with septic shock using speckle-tracking echocardiography. Methods. From May 2017 to December 2018, patients aged ≥18 years admitted to the intensive care unit with the diagnosis of sepsis and septic shock based on the sepsis-3 definition were included. Patients with other causes of cardiac dysfunction were excluded. Transthoracic echocardiography was performed for all the patients within 24 hours of diagnosis. Left ventricular systolic function was assessed using conventional echocardiography and speckle-tracking echocardiography. Results. Patients with septic shock (n = 90) (study group) and 37 matched patients with sepsis but no septic shock (control group) were included. Left ventricular ejection fraction (LVEF) by conventional echocardiography showed no significant difference between two groups (58.2 ± 9.9 vs. 58.6 ± 8.3, p=0.804). The global longitudinal strain (GLS) by STE was significantly reduced in patients with septic shock compared with that in the control (−14.6 ± 3.3 vs. −17.1 ± 3.3, p<0.001). Based on the cutoff value of GLS ≥ −15% for the definition of subclinical left ventricular systolic dysfunction, this dysfunction was detected in 50 patients with septic shock (55.6%) and in 6 patients in the control group (16.2%) (p<0.05). Conclusions. Speckle-tracking echocardiography can detect early subclinical left ventricular systolic dysfunction via the left ventricular global longitudinal strain compared with conventional echocardiographic parameters in patients with septic shock.
Application and Effect of the Gymnastic Exercise Mode during Chemotherapy for Breast Cancer Patients
Authors: Xie Feifei
Published: September 2020

Breast cancer is one of the most common malignant tumors in women, which seriously threatens the health of women. With the improvement of living standards, the incidence rate of breast cancer is also rising. In the past ten years, the incidence rate of breast cancer in China’s major cities has increased by 37%, far higher than that in Europe and America. At present, chemotherapy and radiotherapy are the main treatment methods for breast cancer, but many patients will have cancer-related fatigue after surgery. Some studies believe that appropriate sports can improve cancer-related fatigue, but there is no specific research in this area. In view of this problem, this paper puts forward a rehabilitation training method based on gymnastics for breast cancer surgery. This paper is divided into three parts. The first part is the basic theory and core concept of breast cancer and cancer-related fatigue. Through the in-depth study of the theory, this paper believes that breast cancer patients paying attention to rehabilitation training can effectively improve cancer-related fatigue and affect the final therapeutic effect. The second part is the rehabilitation training program based on the way of gymnastics. The corresponding experimental model is established by using real cases as samples. In order to ensure the quality of the experiment, this paper gives the treatment plan in detail and establishes a unified evaluation system. In the third part of this paper, the relevant experiments and results analysis are given, and through data analysis, this paper believes that gymnastics can effectively help breast cancer patients with postoperative rehabilitation and continuous recovery of the upper limb function and improve cancer-related fatigue and other issues.
Multifractal Analysis of Pore Structure and Evaluation of Deep-Buried Cambrian Dolomite Reservoir with Image Processing: A Case from Tarim Basin, NW China
Authors: Zhang Xiaojun , Han Haodong , Peng Jun , Gou Yingchun
Published: September 2020

Reservoir pore space assessment is of great significance for petroleum exploration and production. However, it is difficult to describe the pore characteristics of deep-buried dolomite reservoirs with the traditional linear method because these rocks have undergone strong modification by tectonic activity and diagenesis and show significant pore space heterogeneity. In this study, 38 dolostone samples from 4 Cambrian formations of Tarim Basin in NW China were collected and 135 thin section images were analyzed. Multifractal theory was used for evaluation of pore space heterogeneity in deep-buried dolostone based on thin section image analysis. The physical parameters, pore structure parameters, and multifractal characteristic parameters were obtained from the digital images. Then, the relationships between lithology and these parameters were discussed. In addition, the pore structure was classified into four categories using K-means clustering analysis based on multifractal parameters. The results show that the multifractal phenomenon generally exists in the pore space of deep-buried dolomite and that multifractal analysis can be used to characterize the heterogeneity of pore space in deep-buried dolomite. For these samples, multifractal parameters, such as αmin, αmax, ΔαL, ΔαR, Δf, and AI, correlate strongly with porosity but only slightly with permeability. However, the parameter Δα, which is usually used to reveal heterogeneity, does not show an obvious link with petrophysical properties. Of dolomites with different fabrics, fine crystalline dolomite and medium crystalline dolomite show the best petrophysical properties and show significant differences in multifractal parameters compared to other dolomites. More accurate porosity estimations were obtained with the multifractal generalized fractal dimension, which provides a new method for porosity prediction. The various categories derived from the K-means clustering analysis of multifractal parameters show distinct differences in petrophysical properties. This proves that reservoir evaluation and pore structure classification can be accurately performed with the K-means clustering analysis method based on multifractal parameters of pore space in deep-buried dolomite reservoirs.
Development and Validation of a Hypoglycemia Risk Model for Intensive Insulin Therapy in Patients with Type 2 Diabetes
Authors: Hu Xiling , Xu Weiran , Lin Shuo , Zhang Cang , Ling Cong , Chen Miaoxia
Published: September 2020

Aims. To develop a simple hypoglycemic prediction model to evaluate the risk of hypoglycemia during hospitalization in patients with type 2 diabetes treated with intensive insulin therapy. Methods. We performed a cross-sectional chart review study utilizing the electronic database of the Third Affiliated Hospital of Sun Yat-sen University, and included 257 patients with type 2 diabetes undergoing intensive insulin therapy in the Department of Endocrinology and Metabolism. Logistic regression analysis was used to derive the clinical prediction rule with hypoglycemia (blood glucose≤3.9 mmol/L) as the main result, and internal verification was performed. Results. In the derivation cohort, the incidence of hypoglycemia was 51%. The final model selected included three variables: fasting insulin, fasting blood glucose, and total treatment time. The area under the curve (AUC) of this model was 0.666 (95% CI: 0.594–0.738, P<0.001). Conclusions. The model’s hypoglycemia prediction and the actual occurrence are in good agreement. The variable data was easy to obtain and the evaluation method was simple, which could provide a reference for the prevention and treatment of hypoglycemia and screen patients with a high risk of hypoglycemia.
The Status of the Quality Control in Neuroimaging Studies of Acupuncture Analgesia
Authors: Gao Zhen , Liu Gaofeng , Zhang Jing , Ji Laixi
Published: September 2020

Neuroimaging technology is an important technology used to explore the neural mechanisms of acupuncture analgesia. In this study, we extracted original studies published in Chinese and English focusing on the use of neuroimaging technology to explore the mechanisms of acupuncture analgesia from PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, Web of Science, and CNKI databases from January 1999 to August 2020. The extracted data were statistically analyzed in terms of year of publication, country, experimental design, and quality control approaches used, sample size, characteristics of participants, acupuncture operation, and other information. Analysis of the literature revealed that international cooperation promotes scientific research. Flexible experimental design can better explain the mechanism of acupuncture analgesia. Reasonable sample size, strict participant inclusion criteria, and standard acupuncture practices are essential for repeatability of conclusions. These findings show that attention should be paid to quality control in future research to improve the reliability of research on acupuncture analgesia.
Analysis of Cumulative Damage for Shared Rock in a Neighborhood Tunnel under Cyclic Blasting Loading Using the Ultrasonic Test
Authors: Cao Feng , Zhang Sheng , Ling Tonghua
Published: September 2020

In blasting excavation of neighborhood tunnels, damage accumulation process in surrounding rock is inevitable. To explore the influence of damage accumulation of rock mass under multiple blasting loads, we analyzed the vibration damage accumulation process of ultrasonic wave velocity of rock mass in shared rock of Liuyuetian neighborhood tunnel through ultrasonic test. Moreover, the effects of cyclic blasting loads on damage to the shared rock in the neighborhood tunnel were discussed and reported. The results demonstrate that the damage accumulation to the shared rock in the neighborhood tunnel is generated after multicycle progressive blasting operations. Influenced by cyclic blasting loads during the posterior excavating tunnel, the damage range of shared rock at the anterior excavating tunnel is 1.2 to 1.4 m, and the damage range of shared rock at the posterior excavating tunnel is 2.2 to 2.4 m. The damage range of shared rock in the posterior excavating tunnel is about 1.71 to 1.83 times that in the anterior excavating tunnel. Under blasting load, the stress concentration zone of shared rock is close to the blasting excavating face and is mainly within 2 m along the longitudinal axis of the tunnel. With continuous advancement of the blasting excavating face, the stress concentration zone moves forward continuously, and a striped stress concentration zone, which is approximately 2 m deep, is formed gradually. Thus, a method was proposed to determine the damage range of shared rock in the neighborhood tunnel during blasting excavation, as well as the variation law of damage. The experiences and conclusions presented can be used as references in the design and construction of similar engineering projects in the future.
Computational Evaluation of the Inhibition Efficacies of HIV Antivirals on SARS-CoV-2 (COVID-19) Protease and Identification of 3D Pharmacophore and Hit Compounds
Authors: Raphael Vinod P. , Shanmughan Shaju K.
Published: September 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the novel coronavirus behind the fast-spreading coronavirus disease 2019 (COVID-19). Pharmaceutical researchers are currently researching medications or preventive vaccines that may be used to treat and combat the spread of COVID-19. Health practitioners all over the world are treating patients with currently available antiviral drugs, primarily the protease inhibitors used for HIV treatment. The present study mainly aims to evaluate the potencies of eight anti-HIV drugs to inhibit coronavirus protease usingin silicomethods. Derivation of pharmacophore, identification of hit molecules, and checking their virtual inhibition efficacies on the COVID-19 protease were also carried out in the present investigation. Classification of eight drug molecules (atazanavir, darunavir, fosamprenavir (amprenavir—metabolised product), saquinavir, lopinavir, ritonavir, nelfinavir, and indinavir) based on their molecular structures was completed and reported. The X-ray crystallographic structure of the main protease of coronavirus (SARS-CoV-2 protease) was obtained from the Protein Data Bank and prepared for computational studies using Edu PyMOL software. Docking studies were performed with AutoDock Vina software, and the results were evaluated with Discovery Studio software. The binding scores of the drugs on protease followed the order saquinavir > nelfinavir > lopinavir = indinavir > darunavir > amprenavir > ritonavir > atazanavir. Web servers such as PharmaGist and ZINCPharmer were employed to derive the 3D pharmacophore and to identify potential hit compounds, respectively. The identified hit molecules were docked with the SARS-CoV-2 protease and analysed. A detailed account of the type of interaction between the protease and the molecules is discussed. The majority of hit compounds displayed appreciable binding affinities on coronavirus protease. Three hit compounds possess structures similar to that of natural products, viz., flavonoids, and nucleoside. These molecules were hydrophilic and slightly deviated from Lipinski parameters. All other derived molecules obeyed the Lipinski rule.In vitro,in vivo,and toxicological studies of these compounds have to be performed before checking the actual druggability of these compounds.
Investigation of Multistage Hydraulic Fracture Optimization Design Methods in Horizontal Shale Oil Wells in the Ordos Basin
Authors: Fu Suotang , Yu Jian , Zhang Kuangsheng , Liu Hanbin , Ma Bing , Su Yuliang
Published: September 2020

Based on the analysis of the typical Ordos well groups, this study began with the accurate characterization of the fracture geometry by adopting advanced laboratory experiment methods and monitoring techniques. Then, with the integration of fracture geometry characterization and in situ stress distributions, fracture optimizations of the target wells were performed through numerical simulations methods. Finally, this study established a sweet spot prediction and identification method for long horizontal shale oil wells and constructed a set of optimization design methods for multistage hydraulic fracturing. This investigation revealed that the hydraulic fractures in Chang-7 terrestrial shale oil reservoirs exhibited the belt pattern, and the primary fractures generated the secondary fractures, which activated the natural fractures and induced shear failure. Macroscopic fractures were found to be perpendicular to the direction of the minimum principal stress. Secondary fractures and activated natural fractures were distributed around the primary fracture in the form of fracture types I and II. Multicluster perforation optimization techniques, which were based on shale reservoir classification and evaluation, and aimed at activating multiclusters and determining fracture sweet spots, were developed. These were successfully applied to the field operation and achieved production enhancement performance.
A Urine Metabonomics Study of Rat Bladder Cancer by Combining Gas Chromatography-Mass Spectrometry with Random Forest Algorithm
Authors: Fang Mengchan , Liu Fan , Huang Lingling , Wu Liqing , Guo Lan , Wan Yiqun
Published: September 2020

A urine metabolomics study based on gas chromatography-mass spectrometry (GC-MS) and multivariate statistical analysis was applied to distinguish rat bladder cancer. Urine samples with different stages were collected from animal models, i.e., the early stage, medium stage, and advanced stage of the bladder cancer model group and healthy group. After resolving urea with urease, the urine samples were extracted with methanol and, then, derived with N, O-Bis(trimethylsilyl) trifluoroacetamide and trimethylchlorosilane (BSTFA + TMCS, 99 : 1, v/v), before analyzed by GC-MS. Three classification models, i.e., healthy control vs. early- and middle-stage groups, healthy control vs. advanced-stage group, and early- and middle-stage groups vs. advanced-stage group, were established to analyze these experimental data by using Random Forests (RF) algorithm, respectively. The classification results showed that combining random forest algorithm with metabolites characters, the differences caused by the progress of disease could be effectively exhibited. Our results showed that glyceric acid, 2, 3-dihydroxybutanoic acid, N-(oxohexyl)-glycine, and D-turanose had higher contributions in classification of different groups. The pathway analysis results showed that these metabolites had relationships with starch and sucrose, glycine, serine, threonine, and galactose metabolism. Our study results suggested that urine metabolomics was an effective approach for disease diagnosis.
Xiaoyao Pills Attenuate Inflammation and Nerve Injury Induced by Lipopolysaccharide in Hippocampal Neurons In Vitro
Authors: Fang Yang , Shi Boyu , Liu Xiaobo , Luo Jie , Rao Zhili , Liu Rong , Zeng Nan
Published: September 2020

Lipopolysaccharides (LPS) are proinflammation mediators that can induce the inflammatory model of the hippocampal neuron, and neuroinflammation participates in the pathophysiology of depression. Xiaoyao Pill is a classical Chinese medicine formula that has been used for the treatment of mental disorders such as depression in China since the Song dynasty. We established a hippocampal neuronal cell inflammation model by LPS and investigate the intervention effect and mechanism of Xiaoyao Pills. The expression levels of IL-6, TNF-α, IDO, 5-HT, brain-derived neurotrophic factor, and β-nerve growth factor were detected by enzyme-linked immunosorbent assay. mRNA levels of IL-6, TNF-α, 5-HT1A, IDO-1, brain-derived neurotrophic factor, nerve growth factor, tropomyosin receptor kinase B, tropomyosin receptor kinase A, and cAMP response element-binding protein were detected by reverse transcription-polymerase chain reaction. To further validate, protein expression was determined by western blot and immunofluorescence. Lipopolysaccharide-induced neuroinflammatory state resulted in the release of IL-6, TNF-α, and IDO and a decrease of BDNF, NGF, TrkB, TrkA, CREB, p-CREB, p-CREB/CREB, and SYP and inhibited hippocampal neurogenesis in the hippocampal neuron. Xiaoyao Pills significantly decreased the levels of IL-6, TNF-α, and IDO in cell supernatant and increased the expression of BDNF, NGF, TrkB, TrkA, CREB, p-CREB, p-CREB/CREB, and SYP as well as the average optical density of BrdU/NeuN double-labelled positive cells. Our study shows that lipopolysaccharides induce inflammation and nerve damage in hippocampal neurons, which are closely related to the pathological mechanism of depression. Xiaoyao Pills (XYW) play an important neuroprotective effect, which is related to its inhibition of neuronal inflammation and promoting the recovery of nerve injury. These results provide a pharmacologic basis for the treatment of depression of XYW in clinical application.
Surgical Design Optimization of Proximal Junctional Kyphosis
Authors: Peng Li , Zhang Guangming , Zuo Heng , Lan Lan , Zhou Xiaobo
Published: September 2020

Purpose. The objective of this study was to construct a procedural planning tool to optimize the proximal junction angle (PJA) to prevent postoperative proximal junctional kyphosis (PJK) for each scoliosis patient. Methods. Twelve patients (9 patients without PJK and 3 patients with PJK) who have been followed up for at least 2 years after surgery were included. After calculating the loading force on the cephalad intervertebral disc of upper instrumented vertebra of each patient, the finite-element method (FEM) was performed to calculate the stress of each element. The stress information was summarized into the difference value before and after operation in different regions of interest. A two-layer fully connected neural network method was applied to model the relationship between the stress information and the risk of PJK. Leave-one-out cross-validation and sensitivity analysis were implemented to assess the accuracy and stability of the trained model. The optimal PJA was predicted based on the learned model by optimization algorithm. Results. The mean prediction accuracy was 83.3% for all these cases, and the area under the curve (AUC) of prediction was 0.889. And the output variance of this model was less than 5% when the important factor values were perturbed in a range of 5%. Conclusion. Our approach integrated biomechanics and machine learning to support the surgical decision. For a new individual, the risk of PJK and optimal PJA can be simultaneously predicted based on the learned model.
Automatic Jamming Modulation Classification Exploiting Convolutional Neural Network for Cognitive Radar
Authors: Wang Feng , Huang Shanshan , Liang Chao
Published: September 2020

Sensing the external complex electromagnetic environment is an important function for cognitive radar, and the concept of cognition has attracted wide attention in the field of radar since it was proposed. In this paper, a novel method based on an idea of multidimensional feature map and convolutional neural network (CNN) is proposed to realize the automatic modulation classification of jamming entering the cognitive radar system. The multidimensional feature map consists of two envelope maps before and after the pulse compression processing and a time-frequency map of the receiving beam signal. Drawing the one-dimensional envelope in a 2-dimensional plane and quantizing the time-frequency data to a 2-dimensional plane, we treat the combination of the three planes (multidimensional feature map) as one picture. A CNN-based algorithm with linear kernel sensing the three planes simultaneously is selected to accomplish jamming classification. The classification of jamming, such as noise frequency modulation jamming, noise amplitude modulation jamming, slice jamming, and dense repeat jamming, is validated by computer simulation. A performance comparison study on convolutional kernels in different size demonstrates the advantage of selecting the linear kernel.