bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study on Dynamic Mechanical Properties and Energy Dissipation of Rocks under Impact Loads
Authors: Yang Renshu , Li Weiyu , Yue Zhongwen
Published: October 2020

Geological conditions are often complex during rock engineering construction (such as blasting and drilling) and usually involve rocks of several or multiple lithologies. However, comparative studies on the dynamic mechanical response of rocks of different lithologies are relatively few. To study differences in dynamic mechanical properties and energy dissipation of rocks of different lithologies, three kinds of rock that are common in rock engineering and have large differences in wave impedance were selected: red sandstone, gray sandstone, and granite. Samples of these three rocks were subjected to impact compression tests at different impact speeds, and the rock fragments after impact compression were screened to quantify the degree of fragmentation. The characteristics of stress wave propagation, dynamic stress-strain relationships, degree of fragmentation, and energy dissipation laws of the three rock types were compared and studied. The results show the following: (1) affected by the wave impedance matching relationship, the reflected waves, strain rates, and reflected energy of the three kinds of rock showed significant differences under the same incident stress wave. (2) The dynamic mechanical characteristics and energy dissipation laws of the rocks all had obvious strain rate effects, but the dynamic uniaxial compressive strength and energy dissipation density of the three rock types had different sensitivities to the strain rate. (3) The change trend of the energy utilization efficiency of the gray sandstone with incident energy was different from that of the red sandstone and granite; there was no obvious extreme point in the incident energy range. The three kinds of rock required different incident energies to reach maximum energy utilization efficiency. (4) The equivalent average fragment size of the three rock types decreased as a function of power with increasing impact velocity and energy dissipation density. (5) Under the same incident wave, although the reflection energy, transmission energy, and degree of fragmentation of the three kinds of rock showed significant differences, the differences in dissipation energy were small.
Accelerometer-Based Automated Counting of Ten Exercises without Exercise-Specific Training or Tuning
Authors: Zelman Samuel , Dow Michael , Tabashum Thasina , Xiao Ting , Albert Mark V.
Published: October 2020

Measuring physical activity using wearable sensors is essential for quantifying adherence to exercise regiments in clinical research and motivating individuals to continue exercising. An important aspect of wearable activity tracking is counting particular movements. One limitation of many previous models is the need to design the counting for a specific exercise. However, during physical therapy, some movements are unique to the patient and also valuable to track. To address this, we create an automatic repetition counting system that is flexible enough to measure multiple distinct and repeating movements during physical therapy without being trained on the specific motion. Accelerometers, using smartphones, were attached to the body or held by participants to track repetitive motions during different exercises. 18 participants completed a series of 10 exercises for 30 seconds, including arm circles, bicep curls, bridges, sit-ups, elbow extensions, leg lifts, lunges, push-ups, squats, and upper trunk rotations. To count the repetitions of each exercise, we apply three analysis techniques: (a) threshold crossing, (b) threshold crossing with a low-pass filter, and (c) Fourier transform. The results demonstrate that arm circles and push-ups can be tracked well, while less periodic and irregular motions such as upper trunk rotations are more difficult. Overall, threshold crossing with low-pass filtering achieves the best performance among these methods. We conclude that the proposed automatic counting system is capable of tracking exercise repetition without prior training and development for that activity.
Three-Prey One-Predator Continuous Time Nonlinear System Model
Authors: Zhang Jingyuan , Yang Yan
Published: October 2020

In this paper, we propose a new multiple-prey one-predator continuous time nonlinear system model, in which the number of teams of preys is equal to 3; namely, a continuous time three-prey one-predator model is put forward and studied. The fourth-order differential equation is established, in which the prey teams help each other. The equilibrium points and stability are analyzed. When not considering preys help each other, we study the global stability and persistence of the model without help terms. The simulation results of system solutions with help terms corresponding to locally asymptotically stable equilibrium points and without help terms corresponding to globally asymptotically stable equilibrium points are given.
Vitamin D Deficiency as a Predictive Factor of Transient Hypocalcemia after Total Thyroidectomy
Authors: Bove A. , Dei Rocini C. , Di Renzo R. M. , Farrukh M. , Palone G. , Chiarini S. , Staniscia T.
Published: October 2020

Background. Total thyroidectomy (TT) is recommended in the treatment of malignant and benignant thyroid diseases, and, to date, transient hypocalcemia is the most frequent complication after the procedure. We prospectively evaluated the role of vitamin D deficiency as a predictor of postoperative hypocalcemia.Methods. This is a prospective cohort study which was conducted between January 2016 and April 2019. A total of 177 consecutive patients (141 (79.7%) women and 36 (20.3%) men) who underwent TT were included in the current study. Hypocalcemia occurred when serum calcium levels were below 8.0 mg/dL or 1.10 mmol/L. Patients were divided into two groups (Group 1, normocalcemic; Group 2, hypocalcemic) and were assessed taking into consideration preoperative serum 25-hydroxy vitamin D (25-OHD) levels, preoperative serum calcium levels, thyroid hormone levels, sex, body mass index (BMI), and smoking habits. Vitamin D deficiency was defined as 25-OHD levels <25 ng/mL.Results. The incidence of postoperative asymptomatic and symptomatic hypocalcemia in the two groups was 19.8% and 15.8%, respectively. Preoperative 25-OHD level was significantly different between Group 1 and Group 2 (31.5 ± 15.0 ng/mL vs 18.7 ± 9.8 ng/mL,p=0.017). Logistic regression analysis revealed that preoperative vitamin D deficiency was a significant predictive factor of postoperative hypocalcemia (p=0.012), and, specifically, the risk of hypocalcemia increased 15-fold in patients with a preoperative vitamin D level <25 ng/mL (odds ratio [OR], 14.8).Conclusions. Postoperative hypocalcemia is significantly associated with low preoperative levels of serum 25-OHD. Our studies demonstrate that vitamin D deficiency (<25 ng/mL) is an independent predictive factor of postoperative hypocalcemia.
Influence of Structural Shape on Earth Pressure for High‐Filled Cut‐and‐Cover Tunnel with and without Load Reduction Based on Discrete Element Method
Authors: Li Sheng , Zhao Liangliang , Ho I-Hsuan , Ning Guixia , Yu Bentian , Wang Changdan
Published: October 2020

In the construction of the Loess Plateau in China, high‐filled cut‐and‐cover tunnels (HFCCTs) had solved the problem of the shortage of land resources. However, this type of structure has a large amount of backfill soil, which leads to the problems of ultrahigh earth pressure and safety of the cut‐and‐cover tunnels (CCTs) lining structure. Previous studies have focused on the load reduction of various flexible materials, ignoring the influence produced by the shape of the CCT structure on the load reduction. Therefore, via a discrete element software, we investigated the changes of vertical earth pressure (VEP), vertical displacement, lateral earth pressure (LEP), and load transfer mechanisms around a HFCCT with consideration to two cases: (1) different shape of CCT structure; (2) the coupling of load reduction using expanded polystyrene (EPS) and the modified shape of the CCT lining structure. The results obtained by the discrete element method (DEM) revealed that an appropriate structural shape influenced the reduction of the VEP above the CCT and that the coupled effects of the load reduction using the EPS and shape modifications of the CCT lining structure could significantly reduce the VEP above the CCT, which enhanced the safety of the CCT. Meanwhile, the optimal values for the shapes of CCTs are derived.
Constitutive Model of Swelling Gypsum Rock
Authors: Xu Chongbang , Gao Xiaojing , Zhang Kaishun , Liu Zhiguo , Zhao Fan
Published: October 2020

Swelling of soft rock, such as gypsum rock, is one of the major threats in tunnel engineering, causing structure damages such as floor heave and inward movement of sidewalls during construction and operation. It is of practical significance to study the swelling mechanical behavior of such rocks by tests. Swelling strain tests and swelling stress tests were performed by swelling test apparatus to study the variation of swelling strain with time and the swelling stress‐strain relationship for gypsum rock samples, respectively. Three stages of the swelling strain on the time‐strain curve of gypsum rock samples were noticed, which are defined as rapid swelling stage, slow swelling stage, and steady stage. And it was further found that the swelling strain caused in the slow swelling stage is of 76% of the total swelling strain. A constitutive model is proposed to describe the stress‐strain relationship in swelling considering the swelling deformation and swelling pressure. The proposed model was verified using test data, which shows good agreements in describing the relationship between swelling strain and swelling stress, also in the conditions of maximum swelling strain and maximum swelling stress under lateral restraint situations.
Research on the Multiobjective Optimization of Microwave Wireless Power Receiving in an Unmanned Aerial Vehicle Network
Authors: Song Yuanming , Liu Yajie , Xu Wanli , Yang Xu , Wang Rui
Published: October 2020

With the wide application of various wireless energy transmission technologies and unmanned aerial vehicle clusters in both production and life, the use of microwave wireless energy transmission to provide a real-time energy supply for an unmanned aerial vehicle network in flight has become an effective way to extend its working time. This paper focuses on the optimization of the energy transmission efficiency and cost in the microwave wireless power receiving process of an unmanned aerial vehicle network. Considering the overall energy transmission efficiency from the power supply terminal to the power receiving network and the cost of the wireless power transmission equipment of the network, we have established a multiobjective wireless power receiving optimization model including a microwave energy emission source and an unmanned aerial vehicle network that receives energy. The model is optimized to select the best wireless power access point and the number of wireless power receiving modules in a network node. In the case study, the optimization model is solved using an evolutionary algorithm, and the solution results verify the effectiveness and correctness of the model.
A Rare Case of Colonic Sarcoidosis Presenting as a Mass
Authors: Sun Haozhe , Makker Jasbir , Patel Harish , Mantri Nikhitha , Hussain Ali N. , Abbas Naeem
Published: October 2020

Introduction. Sarcoidosis is a common multisystem chronic inflammatory disease of an unidentified inciting etiology. The most common initial manifestations of this disease involve the pulmonary system, and involvement of the gastrointestinal tract is rare. Sarcoidosis of the gastrointestinal tract occurs in an oral-anal gradient, with the esophagus and stomach being the most commonly involved sites, while colonic involvement remains extremely rare. Case Presentation. We present a case of a 24-year-old African American man who was evaluated for persistent abdominal pain, chronic diarrhea, and weight loss. Workup for infectious etiologies and celiac disease was unrevealing. An inflammatory mass in the hepatic flexure was found during colonoscopy, and a computed tomography (CT) scan of the abdomen was significant for circumferential thickening of the cecum and ascending colon, along with nodular thickening of the peritoneum without enhancement. Malignancy and inflammatory bowel disease were the initial differentials. A peritoneal biopsy was also performed. Pathology of the colon and peritoneal biopsy was significant for the presence of noncaseating granulomas and confluent granulomatous inflammation. The patient was diagnosed with colonic sarcoidosis, and treatment with corticosteroids was initiated. Symptoms resolved with treatment, and a follow-up colonoscopy five months later showed interval healing. Conclusion. Although rare, colonic sarcoidosis should be considered as one of the differential diagnoses when evaluating a patient with chronic diarrhea and a mass on colonoscopy. Histopathology is the key to diagnosis as it distinguishes malignancy from sarcoidosis. Corticosteroids remain as an option for treating colonic sarcoidosis.
Long-Term Infectious and Noninfectious Outcomes of Monthly Alemtuzumab as a Calcineurin Inhibitor- and Steroid-Free Regimen for Pancreas Transplant Recipients
Authors: Kaplan Adam , Young Jo-Anne H. , Kandaswamy Raja , Berglund Danielle , Knoll Bettina M. , Sieger Gretchen , Cavert Winston , Matas Arthur , Obeid Karam M.
Published: October 2020

Multiple doses of alemtuzumab for immunosuppressive therapy of patients with hematologic malignancies and hematopoietic stem cell transplant have been associated with a high rate of infection. In transplantation, limited alemtuzumab dosing has been successfully used as induction immunosuppression. The effect of multiple doses of alemtuzumab, used as maintenance therapy to minimize steroid and/or calcineurin inhibitor toxicity in solid organ transplant recipients, is unknown. We evaluated the infectious and noninfectious outcomes of 179 pancreas transplant recipients treated with alemtuzumab for induction and maintenance therapy (extended alemtuzumab exposure (EAE)) from 2/28/2003 through 8/31/2005, compared with 159 pancreas transplant recipients with standard induction and maintenance (SIM) therapy performed before (1/1/2002 until 12/31/2002) and after (1/1/2006 until 12/31/2006) the implementation of EAE. EAE was associated with higher risk of overall infections (hazard ratio (HR) 1.33 (1.06–1.66), P=0.01), bacterial infections (HR 1.33 (1.05–1.67), P=0.02), fungal infections (HR 1.86 (1.28–2.71), P<0.01), and cytomegalovirus infections (HR 2.29 (1.39–3.77), P<0.01). In addition, EAE was associated with higher risk of acute cellular rejection (HR 2.09 (1.46–2.99), P<0.01). In conclusion, while a limited alemtuzumab dosing is safe and effective for induction therapy in pancreas transplantation, EAE combined with steroid and calcineurin minimization is associated with a high risk of infectious complications and acute cellular rejection.
Severe SARS-CoV-2 Infection in a Pediatric Patient Requiring Extracorporeal Membrane Oxygenation
Authors: Flood Shannon M. , Osborne Christina M. , Martin Blake , Derderian S. Christopher , Stenson Erin , Grubenhoff Joseph A.
Published: October 2020

The overwhelming majority of pediatric cases of SARS-CoV-2 infection are mild or asymptomatic with only a handful of pediatric deaths reported. We present a case of severe COVID-19 infection in a pediatric patient with signs of hyperinflammation and consumptive coagulopathy requiring intubation and extracorporeal membrane oxygenation (ECMO) and eventual death due to ECMO complications.
Study on the Mechanical Properties of Coal Weakenedby Acidic and Alkaline Solutions
Authors: Xu Dong , Gao Mingshi , Zhao Yichao , He Yongliang , Yu Xin
Published: October 2020

A novel method for fracturing coal is presented in this paper. A chemical solution is injected into coal under high pressure, whereby the coal is fractured and subsequently weakened by chemical erosion over time to produce an anti‐impact soft structure. In this study, the mechanical properties of coal under chemical erosion were investigated, and the fracturing design parameters were optimized. The uniaxial compression test and the split Hopkinson pressure bar (SHPB) test were used to determine the dynamic and static mechanical properties of coal after 20 days of immersion in different chemical solutions. After chemical solution erosion, the dynamic and static compressive strengths and elastic modulus of the coal decreased according to an exponential power law in the damage variable. The chemical treatment increased the duration of the pore compaction stage and decreased that of the elastic deformation stage, while decreasing the brittleness and increasing the ductility of coal. The acoustic emission (AE) curve of the immersed coal samples consisted of four stages corresponding to those of the stress‐strain curve: pore compaction‐closure, a slowly rising linear elastic regime, steady‐state prepeak crack propagation, and unsteady crack propagation at the peak strain. The increase in the damage variable of the coal sample from chemical erosion led to a lower dissipated energy, a higher fractal dimension, and a more fragmented coal sample. The effect of the investigated chemical solutions on weakening the coal mechanical properties decreased in the following order: alkaline solution > acidic solution > NaCl solution > distilled water. The experimental results provide a reference for weakening fractured coal seams.
An Improved Numerical Simulation Approach for the Failure of Rock Bolts Subjected to Tensile Load in Deep Roadway
Authors: Wang Rui , Bai Jian-biao , Yan Shuai , Song Yuan-ba , Wang Guang-dong
Published: October 2020

Our goal was to develop an effective research tool for roadways with significant deformations supported by rock bolts. The improved numerical simulation approach is constructed through additional development of FLAC3D. The aim is to modify the shortcoming that the original model in FLAC3D regards the plastic tensile strain of any arbitrary rock bolt element node as the rupture discrimination criterion. The FISH programming language is adopted to conduct the secondary development and to embed the revised model into the main program of FLAC3D. Taking an actual mining roadway as the simulation object, two simulation schemes adopting the newly improved approach and the original method were conducted, respectively. The results show that (1) the PILE element that constitutes the rock bolt-free section with the maximum elongation rate ruptures after modification, while the rock bolt tendon elongation rate reaches beyond the predefined tensile rupture elongation rate; (2) the modified model in which the rock bolt is mainly subjected to tension realises the tensile rupture phenomenon at the end of the rock bolt-free section and the rock bolt at the junction between the free section and the anchoring section; and (3) only four rock bolts that are in the roadway sides showed rupture in the modified model, and all rock bolts showed rupture in the original model. The tensile failure of the rock bolt led that the modified model scheme is closer to the actual. Compared with the modified model, in the original model, deformation of the surrounding rock masses is severe. This is resulted by the rupture of all rock bolts in the original model. The analysis shows that the improved numerical simulation approach is much more reliable for large deformation roadway behavior with rock bolt support.
Severe COVID-19 in Third Trimester Pregnancy: Multidisciplinary Approach
Authors: Pelayo Jerald , Pugliese Gabriella , Salacup Grace , Quintero Eduardo , Khalifeh Adeeb , Jaspan David , Sharma Bhavna
Published: October 2020

The rapidly expanding cases of the coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have exposed vulnerable populations, including pregnant women to an unprecedented public health crisis. Recent data show that pregnancy in COVID-19 patients is associated with increased hospitalization, admission of the intensive care unit, and intubation. However, very few resources exist to guide the multidisciplinary team in managing critically ill pregnant women with COVID-19. We report our experience with managing a morbidly obese pregnant woman at 36 weeks’ gestation with history of asthma and malignancy who presented with persistent respiratory symptoms at an outside hospital after being tested positive for SARS-CoV-2 polymerase chain reaction (PCR). Early in the course of the hospitalization, patient received remdesivir, convalescent plasma, bronchodilator, systemic steroids, and IV heparin for COVID-19 and concomitant asthma exacerbation and pulmonary embolism. Due to increasing oxygen requirements, she was eventually intubated and transferred to our institution for higher level of care. Respiratory acidosis, severe hypoxemia, and vent asynchrony were managed with vent setting adjustment and paralytics. After 12 hours from spontaneous rupture of her membranes and with stabilization of maternal status, patient underwent a term cesarean delivery for nonreassuring fetal heart tracing. The neonate was discharged on the 2nd day of life, while the patient was extubated on the 6th postpartum day and was discharged to acute inpatient rehabilitation facility on the 19th hospital day. This report highlights the disease progression of COVID-19 in a pregnant woman, the clinical challenges in the critical care aspect of patient management, and the proposed multidisciplinary strategies utilizing an algorithmic approach to optimize maternal and neonatal outcomes.
Chronic Kidney Disease among Diabetes Patients in Ethiopia: A Systematic Review and Meta-Analysis
Authors: Shiferaw Wondimeneh Shibabaw , Akalu Tadesse Yirga , Aynalem Yared Asmare
Published: October 2020

Background. Though different primary studies have reported the burden of chronic kidney disease among diabetes patients, their results have demonstrated substantial variation regarding its prevalence in Ethiopia. Therefore, this study aimed to estimate the pooled prevalence of chronic kidney disease and its associated factors among diabetes patients in Ethiopia.Method. PubMed, African Journals Online, Google Scholar, Scopus, and Wiley Online Library were searched to identify relevant studies. TheI2statistic was used to check heterogeneity across the included studies. A random-effects model was applied to estimate the pooled effect size across studies. A funnel plot and Egger’s regression test were used to determine the presence of publication bias. All statistical analyses were performed using STATA™ version 14 software.Result. In this meta-analysis, a total of 12 studies with 4,075 study participants were included. The estimated prevalence of CKD among diabetes patients was found to be 35.52% (95% CI: 25.9–45.45,I2 = 96.3%) for CKD stages 1 to 5 and 14.5% (95% CI: 10.5–18.49,I2 = 91.1%) for CKD stages 3 to 5. Age greater than 60 years (OR = 2.99; 95% CI: 1.56–5.73), female sex (OR = 1.68; 95% CI: 1.04–2.69), duration of diabetes >10 years (OR = 2.76; 95% CI: 1.38–5.51), body mass index >30 kg/m2(OR = 2.06; 95% CI: 1.41–3.00), type 2 diabetes (OR = 2.54; 95% CI: 1.73–3.73), poor glycemic control (OR = 2.01; 95% CI: 1.34–3.02), fasting blood glucose >150 mg/dl (OR = 2.58; 95% CI: 1.79–3.72), high density lipoprotein >40 mg/dl (OR = 0.48; 95% CI: 0.30–0.85–25), systolic blood pressure>140 mmHg (OR = 3.26; 95% CI: 2.24–4.74), and diabetic retinopathy (OR = 4.54; CI: 1.08–25) were significantly associated with CKD.Conclusion. This study revealed that the prevalence of chronic kidney disease remains high among diabetes patients in Ethiopia. This study found that a long duration of diabetes, age>60 years, diabetic retinopathy, female sex, family history of kidney disease, poor glycemic control, systolic blood pressure, overweight, and high level of high-density lipoprotein were associated with chronic kidney disease among diabetic patients. Therefore, situation-based interventions and context-specific preventive strategies should be developed to reduce the prevalence and risk factors of chronic kidney disease among diabetes patients.
Aberrant Advanced Cognitive and Attention-Related Brain Networks in Parkinson’s Disease with Freezing of Gait
Authors: Li Yuting , Ruan Xiuhang , Li E. , Zhang Guoqin , Liu Yanjun , Du Yuchen , Wang Zhaoxiu , Yu Shaode , Yang Ruimeng , Li Mengyan , Wei Xinhua
Published: October 2020

Background. Freezing of gait (FOG) is a disabling gait disorder influencing patients with Parkinson’s disease (PD). Accumulating evidence suggests that FOG is related to the functional alterations within brain networks. We investigated the changes in brain resting-state functional connectivity (FC) in patients with PD with FOG (FOG+) and without FOG (FOG-). Methods. Resting-state functional magnetic resonance imaging (RS-fMRI) data were collected from 55 PD patients (25 FOG+ and 30 FOG-) and 26 matched healthy controls (HC). Differences in intranetwork connectivity between FOG+, FOG-, and HC individuals were explored using independent component analysis (ICA). Results. Seven resting-state networks (RSNs) with abnormalities, including motor, executive, and cognitive-related networks, were found in PD patients compared to HC. Compared to FOG- patients, FOG+ patients had increased FC in advanced cognitive and attention-related networks. In addition, the FC values of the auditory network and default mode network were positively correlated with the Gait and Falls Questionnaire (GFQ) and Freezing of Gait Questionnaire (FOGQ) scores in FOG+ patients. Conclusions. Our findings suggest that the neural basis of PD is associated with impairments of multiple functional networks. Notably, alterations of advanced cognitive and attention-related networks rather than motor networks may be related to the mechanism of FOG.
An Enhanced Percolation Method for Automatic Detection of Cracks in Concrete Bridges
Authors: Gao Qingfei , Wang Yu , Li Jun , Sheng Kejian , Liu Chenguang
Published: October 2020

As cracks on concrete bridges become severer and more frequent, methods of detecting cracks on concrete bridges have aroused great concern. Conventional methods, e.g., manual detection and equipment‐aided detection, suffer from subjectivity and inefficiency, which increases demands for an accurate and efficient method to detect bridge cracks. To this end, we modify the existing percolation method and propose an enhanced percolation method, which detects cracks of concrete bridges automatically. The modification includes three improvements, which are (1) employing photo expansion to eliminate boundary effects, (2) varying shape factors to increase the accuracy of percolating unclear cracks, and (3) decreasing the number of neighbouring pixels to form candidate sets. Combined with the above three improvements, three versions of enhanced percolation methods utilizing three different shape factors are put forward. The numerical experiment on detecting cracks in 200 images of the bridge surface demonstrates the outperformance of the enhanced percolation method in precision, recall, F‐1 score, and time compared with traditional detecting methods. The proposed method can be generalized on the application of detecting other types of bridge diseases, which is an advantage for designing, maintaining, and restoring infrastructures.
Prediction and Analysis of Abnormal Gas Emission Law in Low-Gas Tunnel Based on K-Line Diagram
Authors: Wang Haiyang , Zhao Shulei , Liu Jialiang , Zhou Yanmin , Chen Xiang , Wang Jie , Cheng Liang
Published: October 2020

The risk of gas disaster in the low-gas tunnel is easy to be ignored. By tracking and analyzing the gas monitoring data of the low-gas tunnel, it is found that the cyclic abnormal gas emission occurred many times during the construction period, leading to local gas accumulation, which greatly increases the risk of gas explosion accidents. To scientifically predict the abnormal gas emission in low-gas tunnels, the idea of K-line diagram-based prediction of abnormal gas emission in low-gas tunnels is put forward, and in combination with the field monitoring data of low-gas tunnel (Huangguashan Tunnel), the prediction results with different prediction indexes of K-line diagram are compared and analyzed. The results show that the K-line diagram can reflect the changing trend of gas concentration in real time accurately and show the change law of gas concentration during different construction processes; the moving average (MA) of the K-line diagram can accurately reflect the time of abnormal gas emission, the moving average convergence divergence (MACD) index can reflect the upward or downward power and trend of gas, and the Bollinger Band (BOLL) index can reflect the fluctuation range of gas concentration. The research results can provide a reference for the prediction and prevention of abnormal gas emission in low-gas tunnels.
NDM-1-Positive K. pneumoniae at a Teaching Hospital in Southwestern China: Clinical Characteristics, Antimicrobial Resistance, Molecular Characterization, Biofilm Assay, and Virulence
Authors: Yang Kai , Liu Shumin , Li Huanqin , Du Na , Yao Jing , He Qiuyue , Du Yan
Published: October 2020

Background. The emergence of the NDM-1-positive Klebsiella pneumoniae (K. pneumoniae) strains has led to limited therapeutic options for clinical treatment. Understanding the clinical characteristics, antimicrobial resistance, biofilm assay, and the virulence genes of these isolated strains is of great significance. Methods. The polymerase chain reaction (PCR) was used to screen isolated NDM-1-positive K. pneumoniae. The clinical information of the patients was collected from medical records. The NDM-1-positive K. pneumoniae isolates were subjected to antimicrobial susceptibility testing and multilocus sequence typing. Sixty strains of NDM-1-negative K. pneumoniae isolated during the same period were collected as the control group for the virulence analysis. The virulence phenotype of the strains was preliminarily evaluated by the string test and crystal violet semiquantitative biofilm formation experiment. PCR combined with gene sequencing was used to detect common high toxicity capsule genes (K1, K2, K5, K20, K54, and K57) and common virulence-related genes (entB, ybtS, ureA, ycf, WabG, FimH, uge, iutA, KfuB, aerobactin, rmpA, magA, Alls, IrnN, and VatD). Results. In the 30 nonduplicated NDM-1-positive K. pneumoniae isolates, 43.33% (13/30) of the patients had a history of a stay in the neonatal intensive care unit (NICU). All of the isolates exhibited multidrug resistance. Nine STs were identified, 77% (10/13) strains from the NICU were ST11. The NDM-1-positive K. pneumoniae string tests were all negative, and 35% (21/60) NDM-1-negative K. pneumoniae were positive. The ratios of NDM-1-positive K. pneumoniae isolates biofilm formation ability according to strong, medium, and weak classification were 67%, 23%, and 10%, respectively. NDM-1-negative K. pneumoniae isolates were 60%, 25%, and 15%, respectively. There was no statistical difference between the two groups (t = 0.61, P=0.2723). The virulence-associated genes with more than 80% of detection rates among the 30 NDM-1-positive K. pneumoniae isolates included entB (100%, 30/30), ybtS (93.33%, 28/30), ureA (90%, 27/30), ycf (83.33%, 25/30), and wabG (90%, 27/30). KfuB and iutA were detected at prevalence of 3.33% and 13.33%. vatD, allS, iroN, aerobactin, and rmpA were not detected. In the NDM-1-negative K. pneumoniae, all other 14 virulence genes except VatD were detected. After statistical analysis, FimH, WabG, ycf, iutA, kfuB, aerobactin, rmpA, and Alls virulence genes, P<0.005, there was a statistical difference. Conclusion. NDM-1-positive K. pneumoniae exhibited multidrug resistance, MLST typing is mainly ST11, there is small clonal dissemination in the NICU in the hospital, and the NDM-1-positive K. pneumoniae virulence genes carrier rate is lower than the NDM-1-negative K. pneumoniae virulence genes carrier rate.
Green Synthesis of Spherical Calcium Hydroxide Nanoparticles in the Presence of Tannic Acid
Authors: Chen Peiyuan , Wang Yonghui , He Shicheng , Wang Pengju , Xu Ying , Zhang Liheng
Published: October 2020

This study proposes a green, low‐cost, and robust method to synthesize spherical calcium hydroxide (CH) nanoparticles based on the co‐precipitation of Ca2+ and OH− in the presence of tannic acid (TA), an inexpensive plant‐derived polyphenol. It has been found that the morphology and crystalline phase of the produced CH nanoparticles can be controlled by TA. With the increasing dosage of TA, the crystallinity of the CH particles reduces, changing from well crystallization to amorphous phases. Experimental evidence suggests that complexion reaction took place between TA and Ca2+, which gave the Ca2+ a strong bond effect. As a result, the nucleation and growth of CH were significantly affected. CH nanoparticles with sizes of about 50 nm have been successfully synthesized by using 0.3% or more TA.
Effect of Microarc Oxidation Treatment with Different Concentrations of MgSiF6 on Titanium‐Porcelain Bonding Strength
Authors: Lv Jing , Yuan Mujie , Sun Pei , Wei Changlei , Zhang Shaojun , Wang Yaozhong , Liu Jie , Tan Fei
Published: October 2020

This study aims to evaluate the effects of different electrolyte concentrations on titanium‐porcelain bonding strength after microarc oxidation (MAO) treatment. Four MgSiF6 electrolyte concentrations (10 g/L, 20 g/L, 30 g/L, and 40 g/L) were chosen for the MAO bath solutions. According to ISO 9693, the bonding strengths of titanium‐porcelain restorations were detected by the three‐point bending test. Scanning electron microscopy (SEM) and energy‐dispersive spectroscopy (EDS) were applied to evaluate the morphologies and elemental compositions of the MAO coating, titanium‐porcelain fracture surfaces, titanium‐porcelain interfaces, and oxygen diffusion. The bonding strength of the 20 g/L MgSiF6 group was significantly higher than that of the control group. However, overly high MgSiF6 concentrations had a negative influence on the bonding strength between titanium and porcelain. The results demonstrate that MAO treatment with only appropriate electrolyte concentration can improve the titanium‐porcelain bonding strength.
Macroalgae Sargassum cristaefolium Extract Inhibits Proinflammatory Cytokine Expression in BALB/C Mice
Authors: Prasedya Eka Sunarwidhi , Martyasari Ni Wayan Riyani , Abidin Angga Susmana , Pebriani Sonia Ardilla , Ilhami Bq Tri Khairina , Frediansyah Andri , Sunarwidhi Anggit Listyacahyani , Widyastuti Sri , Sunarpi Haji
Published: October 2020

Ultraviolet radiation (UVR) which could induce skin damage and skin disease is a growing concern due to the increase in global warming. Brown macroalgae Sargassum cristaefolium has been recognized to exhibit UV protective activities. However, the mechanism of its photoprotective activity remains unclear. The purpose of this study is to investigate the potential mechanism of S. cristaefolium’s photoprotective activity against UV radiation. Phytochemical analyses revealed valuable bioactive compounds in SCE, such as fucoxanthin which is widely known as an anti-inflammatory carotenoid. Treatment with SCE before UV-A radiation show reduced levels of wrinkles and desquamation. Interestingly, SCE treatment induces the skin healing process after UV radiation. SCE effectively inhibited proinflammatory TNF-α and IL-6 expression while increasing IL-10 production in the BALB/c mice skin. Current results suggest that SCE potentially protects the skin by attenuation of inflammatory cytokines. In addition, SCE demonstrates promising antibacterial activity (MIC = 1.302 µg/mL) against Staphylococcus aureus. Overall, SCE could be a source of an effective anti-inflammatory agent protecting against UV irradiation-induced skin damages.
Distribution Route Optimization for Electric Vehicles in Urban Cold Chain Logistics for Fresh Products under Time-Varying Traffic Conditions
Authors: Zhao Zhixue , Li Xiamiao , Zhou Xiancheng
Published: October 2020

Electric vehicles (EVs) have been widely used in urban cold chain logistic distribution and transportation of fresh products. In this paper, an electric vehicle routing problem (EVRP) model under time-varying traffic conditions is designed for planning the itinerary for fresh products in the urban cold chain. The object of the EVRP model is to minimize the total cost of logistic distribution that includes economic cost and fresh value loss cost. To reflect the real situation, the EVRP model considers several influencing factors, including time-varying road network traffic, road type, client’s time-window requirement, freshness of fresh products, and en route queuing for charging. Furthermore, to address the EVRP, an improved adaptive ant colony algorithm is designed. Simulation test results show that the proposed method can allow EVs to effectively avoid traffic congestion during the distribution process, reduce the total distribution cost, and improve the performance of the cold chain logistic distribution process for fresh products.
Cerebral Hyperperfusion Syndrome and Related Conditions
Authors: Delgado Montserrat González , Bogousslavsky Julien
Published: October 2020

Cerebral vasoconstriction is a normal physiological response under determined conditions to preserve a normal cerebral blood flow. However, there are several syndromes, with impaired cerebral autoregulation and cerebral vasoconstriction, not related with infection or inflammation, which share the same radiological and clinical presentation. We review here the cerebral hyperperfusion syndrome and related conditions such as hypertensive encephalopathy, posterior reversible encephalopathy syndrome, and reversible cerebral vasoconstriction syndrome. These syndromes might share the same pathophysiological mechanism with endothelial damage, cerebral vasoconstriction, blood-brain barrier disturbance, cerebral edema, and, occasionally, intracerebral hemorrhage, with fatal cases described in all. Despite knowledge of these syndromes, they still remain unknown to us. Why these entities present in some patients and not in others goes further than the actual understanding of these diseases. We have to consider that a genetic susceptibility and molecular disturbances may be involved. Thus, more studies are needed in order to better characterize such syndromes.
A review of website evaluation using web diagnostic tools and data envelopment analysis
Authors: Najadat Hassan , Al-Badarneh Amer , Alodibat Sawsan
Published: October 2020

This paper presents a review of the most recently published works of the use of data envelopment analysis (DEA) in the evaluation of websites of different fields such as healthcare, e-business, e-commerce, and e-government. The evaluation of websites is performed using web diagnostic tools (WDTs). Some studies have evaluated e-government websites using WDTs only, while others integrate them with data envelopment analysis. We summarize each study including the country that was conducted in, the size of data set, inputs to DEA, outputs from DEA, the approach used, the tools used, and the results obtained. It also covers whether there is a use of combination between DEA and data mining or machine learning approaches to classify the efficiency of these websites.
Reconfiguration layers of convolutional neural network for fundus patches classification
Authors: Setiawan Wahyudi , Utoyo Moh. Imam , Rulaningtyas Riries
Published: October 2020

Convolutional neural network (CNN) is a method of supervised deep learning. The architectures including AlexNet, VGG16, VGG19, ResNet 50, ResNet101, GoogleNet, Inception-V3, Inception ResNet-V2, and Squeezenet that have 25 to 825 layers. This study aims to simplify layers of CNN architectures and increased accuracy for fundus patches classification. Fundus patches classify two categories: normal and neovascularization. Data used for classification is MESSIDOR and Retina Image Bank that have 2,080 patches. Results show the best accuracy of 93.17% for original data and 99,33% for augmentation data using CNN 31 layers. It consists input layer, 7 convolutional layers, 7 batch normalization, 7 rectified linear unit, 6 max-pooling, fully connected layer, softmax, and output layer.
Band pass filter comparison of Hairpin line and square open-loop resonator method for digital TV community
Authors: Prasetya Budi , Rohmah Yuyun Siti , Nurmantris Dwi Andi , Mulyawati Sarah , Dipayana Reza
Published: October 2020

The selection of the right filter design method is a very important first step for a radio frequency engineer. This paper presents the comparison of two methods of band pass filter design using hairpin-line and square open-loop resonator. Both methods were applied to obtain filter designs that can work for broadcasting system in digital television community. Band pass filter was simulated using design software and fabricated using epoxy FR-4 substrate. The results of simulation and measurement shown return loss value at 27.3 dB for hairpin line band pass filter and 25.901 for square open-loop resonator band pass filter. Voltage standing wave ratio parameter values were 1.09 and 1.1067 for hairpin line and square open-loop band pass filter respectively. The insertion loss values for the Hairpin line band pass filter and square open-loop band pass filter were 0.9692 and near 0 dB, respectively. Fractional bandwidth, for hairpin line band pass filter, was 6.7% while for square open-loop band pass filter was 4.8%. Regarding the size, the dimension of square open-loop resonator was approximately five times larger than hairpin-line band pass filter. Based on the advantages of the hairpin line method, we recommend that researchers choose the filter for digital TV broadcasting.
Discretization methods for Bayesian networks in the case of the earthquake
Authors: Sari Devni Prima , Rosadi Dedi , Effendie Adhitya Ronnie , Danardono Danardono
Published: October 2020

The Bayesian networks are a graphical probability model that represents interactions between variables. This model has been widely applied in various fields, including in the case of disaster. In applying field data, we often find a mixture of variable types, which is a combination of continuous variables and discrete variables. For data processing using hybrid and continuous Bayesian networks, all continuous variables must be normally distributed. If normal conditions unsatisfied, we offer a solution, is to discretize continuous variables. Next, we can continue the process with the discrete Bayesian networks. The discretization of a variable can be done in various ways, including equal-width, equal-frequency, and K-means. The combination of BN and k-means is a new contribution in this study called the k-means Bayesian networks (KMBN) model. In this study, we compared the three methods of discretization used a confusion matrix. Based on the earthquake damage data, the K-means clustering method produced the highest level of accuracy. This result indicates that K-means is the best method for discretizing the data that we use in this study.
Data falsification attacks in advanced metering infrastructure
Authors: Baskaran Hasventhran , Al-Ghaili Abbas M. , Ibrahim Zul- Azri , Rahim Fiza Abdul , Muthaiyah Saravanan , Kasim Hairoladenan
Published: October 2020

Smart grids are the cutting-edge electric power systems that make use of the latest digital communication technologies to supply end-user electricity, but with more effective control and can completely fill end user supply and demand. Advanced Metering Infrastructure (AMI), the backbone of smart grids, can be used to provide a range of power applications and services based on AMI data. The increased deployment of smart meters and AMI have attracted attackers to exploit smart grid vulnerabilities and try to take advantage of the AMI and smart meter’s weakness. One of the possible major attacks in the AMI environment is False Data Injection Attack (FDIA). FDIA will try to manipulate the user’s electric consumption by falsified the data supplied by the smart meter value in a smart grid system using additive and deductive attack methods to cause loss to both customers and utility providers. This paper will explore two possible attacks, the additive and deductive data falsification attack and illustrate the taxonomy of attack behaviors that results in additive and deductive attacks. This paper contributes to real smart meter datasets in order to come up with a financial impact to both energy provider and end-user.
A Review of anomaly detection techniques in advanced metering infrastructure
Authors: Al-Ghaili Abbas M. , Ibrahim Zul- Azri , Hairi Syazwani Arissa Shah , Rahim Fiza Abdul , Baskaran Hasventhran , Ariffin Noor Afiza Mohd , Kasim Hairoladenan
Published: October 2020

Advanced Metering Infrastructure (AMI) is a component of electrical networks that combines the energy and telecommunication infrastructure to collect, measure and analyze consumer energy consumptions. One of the main elements of AMI is a smart meter that used to manage electricity generation and distribution to end-user. The rapid implementation of AMI raises the need to deliver better maintenance performance and monitoring more efficiently while keeping consumers informed on their consumption habits. The convergence from analog to digital has made AMI tend to inherit the current vulnerabilities of digital devices that prone to cyber-attack, where attackers can manipulate the consumer energy consumption for their benefit. A huge amount of data generated in AMI allows attackers to manipulate the consumer energy consumption to their benefit once they manage to hack into the AMI environment. Anomalies detection is a technique can be used to identify any rare event such as data manipulation that happens in AMI based on the data collected from the smart meter. The purpose of this study is to review existing studies on anomalies techniques used to detect data manipulation in AMI and smart grid systems. Furthermore, several measurement methods and approaches used by existing studies will be addressed.
Requirements identification for distributed agile team communication using high level carotene
Authors: Abidin Nor Hidayah Zainal , Samat Pathiah Abdul
Published: October 2020

Communication plays an important role to deliver the correct information. However, the communication became challenging especially for agile software teams, which are in geographical distributed. The problem arise when there are exchanging information using unstructured communication platform, misunderstanding on the information communicated and lack of documentation. The aim of this study is to propose a text classification technique for requirements identification in text messages. In this study, we adopted the cascade and cluster classification concept of Carotene that relies on the hash tag function. It classifies the text messages into requirements types instead of job title. This technique called as high-level carotene (HLC) technique that embedded into the tool to identify the functional requirement and non-functional requirements. The result shows that most of criterias evaluated have achieved more than 85% of effectiveness in identifying both of requirement in text messaging by using this technique.