• Acute Effects of Assisted Cycling Therapy on Post-Stroke Motor Function: A Pilot Study

      Holzapfel, Simon D.; Bosch, Pamela R.; Lee, Chong D.; Pohl, Patricia S.; Szeto, Monica; Heyer, Brittany; Ringenbach, Shannon D.; Univ Arizona, Coll Med Phoenix (HINDAWI LTD, 2019)
      Background. Stroke is the most common cause of long-term disability in the United States (US). Assisted Cycling Therapy (ACT) at cadences of about 80 rpm has been associated with improvements in motor and clinical function in other clinical populations. The acute effects of ACT on motor function of persons with stroke have not been investigated. Objectives. The primary purpose of this cross-over trial was to compare the effects of ACT, voluntary cycling (VC), and no cycling (NC) on upper (Box and Blocks Test) and lower extremity motor function (Lower Extremity Motor Coordination Test) in adults with chronic stroke (age: 60 +/- 16 years; months since stroke: 96 +/- 85). The secondary purpose was to examine average cycling cadence and ratings of perceived exertion as predictors of change in motor function following the exercise session. Methods. Twenty-two participants (female = 6, male = 16) completed one 20-min session each of ACT (mean cadence = 79.5 rpm, VC (mean cadence = 51.5 rpm), and NC on separate days in quasi-counterbalanced fashion). Results. Main effects of intervention did not differ between ACT and VC. Within-intervention analyses revealed significant (p < 0.05) pre- to posttest changes in all outcome measures for ACT but only in the Lower Extremity Motor Coordination Test on the non-paretic side for VC. Trend analyses revealed a positive relationship between average ACT cadences and improvements in upper and lower extremity motor function (p < 0.05). A positive relationship between average VC cadences and lower extremity function was also revealed (p < 0.05). Conclusion. ACT and VC produced similar acute improvements in paretic and non-paretic lower extremity motor function whereas changes in upper extremity motor function were more limited. Faster cycling cadences seem to be associated with greater acute effects.
    • Atrial Septal Defect with Eisenmenger Syndrome: A Rare Presentation

      Forlemu, Arnold Nongmoh; Ajmal, Muhammad; Saririan, Mehrdad; Univ Arizona, Coll Med Tucson, Sarver Heart Ctr, Dept Cardiol (HINDAWI LTD, 2020-03-09)
      Atrial septal defects (ASDs) are common congenital heart defects (CHD). The clinical course in patients without closure of the ASD is associated with significant morbidity and mortality in advanced age. A small percentage of patients may develop pulmonary arterial hypertension (PAH) due to left to right shunting that impacts morbidity and mortality. Advances in prenatal screening and fetal echocardiography have allowed timely interventions. Nonetheless, some patients still may be diagnosed with ASD in adulthood as an incidental finding or presenting with clinical symptoms such as shortness of breath from right heart failure. We report a case of an adult female presenting with shortness of breath due to ASD causing PAH with Eisenmenger physiology.
    • Attenuated Late-Phase Arc Transcription in the Dentate Gyrus of Mice Lacking Egr3

      Maple, Amanda; Lackie, Rachel E.; Elizalde, Diana I.; Grella, Stephanie L.; Damphousse, Chelsey C.; Xa, Collin; Gallitano, Amelia L.; Marrone, Diano F.; Univ Arizona, Dept Basic Med Sci; Univ Arizona, McKnight Brain Inst; et al. (HINDAWI LTD, 2017)
      The dentate gyrus (DG) engages in sustained Arc transcription for at least 8 hours following behavioral induction, and this time course may be functionally coupled to the unique role of the DG in hippocampus-dependent learning and memory. The factors that regulate long-term DG Arc expression, however, remain poorly understood. Animals lacking Egr(3) show less Arc expression following convulsive stimulation, but the effect of Egr3 ablation on behaviorally induced Arc remains unknown. To address this, Egr3(-/-) and wild-type (WT) mice explored novel spatial environments and were sacrificed either immediately or after 5, 60, 240, or 480 minutes, and Arc expression was quantified by fluorescence in situ hybridization. Although short-term (i.e., within 60 min) Arc expression was equivalent across genotypes, DG Arc expression was selectively reduced at 240 and 480 minutes in mice lacking Egr3. These data demonstrate the involvement of Egr3 in regulating the late protein-dependent phase of Arc expression in the DG.
    • A Case of Myeloid Sarcoma following Allogeneic HSCT Presenting as Localized Hip Pain

      Zhang, Shannon; Charlton, Casey; Amaraneni, Akshay; Maher, Keri; Univ Arizona, Tucson Coll Med (HINDAWI LTD, 2019-10-02)
      Myeloid sarcoma is a rare variant of acute myeloid leukemia (AML) which presents as an extramedullary soft tissue mass. Due to the rarity of this disease, along with nonspecific presenting symptoms, diagnosis can be delayed or missed without a high index of suspicion. In this case, we discuss a patient diagnosed with AML relapse in the form of myeloid sarcoma two years after allogeneic hematopoietic stem cell transplant (alloHSCT) for myelodysplastic syndrome (MDS) with the initial presentation for back pain misdiagnosed as spinal stenosis. This case report aims to help healthcare providers in recognizing the early signs and symptoms of this disorder as well as provide information in regards to treatment options and risk assessment.
    • Clinicopathological and Molecular Characteristics of Pleomorphic Invasive Lobular Carcinoma

      Segar, Jennifer M; Pandey, Ritu; Farr, Kiah J; Nagle, Raymond; LeBeau, Lauren; Gonzalez, Victor J; Chalasani, Pavani; Univ Arizona, Ctr Canc; Univ Arizona, Dept Med; Univ Arizona, Coll Med; et al. (HINDAWI LTD, 2020-11-23)
      Pleomorphic invasive lobular carcinoma (PILC) is a distinct morphological and biologically aggressive variant of invasive lobular carcinoma (ILC). We hypothesized that was due to de novo activation of PI3K/Akt/mTOR pathway in PILC resulting in higher proliferation rate and markers of cell cycle activation. We identified PILC and ILC tumors and tested for PI3K/Akt/mTOR pathway activation by immunohistochemistry (PTEN and pS6K1) and gene expression analysis (by Nanostring nCounter system). Proliferation index (Ki67) was elevated in 85% of PILCs compared to 20% of ILCs (p < 0.007). PTEN expression was high in all while pS6K1 was high in 8/9 PILCs compared to 3/9 ILCs (p < 0.007). Gene expression analysis shows that PILCs have overexpression of genes involved in cell cycle proliferation, cellular proliferation, DNA damage, and repair genes but no difference in PI3K/Akt/mTOR pathway genes. PILCs are a biologically distinct group of ILC, and clinicopathological characteristics suggest they would have a more clinically aggressive behavior. In addition, our results indicate that PI3k/Akt/mTOR pathway and cell cycle proliferation are activated in majority of these tumors. Further studies are needed to investigate these mechanisms as there are approved therapies available that may benefit PILCs.
    • Comparative Study of Nonlinear Static and Time-History Analyses of Typical Korean STS Container Cranes

      Tran, Quang Huy; Huh, Jungwon; Nguyen, Van Bac; Haldar, Achintya; Kang, Choonghyun; Hwang, Kyeong Min; Univ Arizona, Dept Civil Engn & Engn Mech (HINDAWI LTD, 2018)
      Ship-to-shore (STS) container gantry cranes, used at terminals for loading and unloading containers from a ship, are an important part of harbor structures. The size and weight of modern STS container cranes are increasing to satisfy the demand for bigger ships. This is expected to result in more lateral load when excited by seismic motions. The existing Korean STS container cranes did not behave properly during several recent moderate earthquakes in South Korea. Typical Korean STS container cranes must be checked for the earthquake-resistant capacity. In this research, two nonlinear static analyses procedures, also known as pushover analyses, commonly used for seismic design of buildings, namely, capacity spectrum method and equivalent linearization method, are comprehensively studied to check their suitability for studying seismic behavior of STS cranes. Results obtained by these two nonlinear static analysis methods are then compared with the results obtained by nonlinear time-history analyses of the STS cranes by exciting them with nine recorded earthquake time histories around worldwide. The behaviors of the cranes are analyzed in terms of the total base shear, drift, and base uplift. The comparisons indicate that the nonlinear static methods can be appropriate for estimating the total base shear and drift of the portal frame of a container crane. The pushover analyses also provide information on performance levels as defined in ASCE/SEI 41-13, of a typical Korean STS container crane. Furthermore, it is observed that the uplift response of the crane is strongly influenced by the duration of an earthquake.
    • Comparing and Correlating Outcomes between Open and Percutaneous Access in Endovascular Aneurysm Repair in Aortic Aneurysms Using a Retrospective Cohort Study Design

      DeVito, Peter; Kimyaghalam, Ali; Shoukry, Sameh; DeVito, Robert; Williams, John; Kumar, Eashaa; Vitvitsky, Eugene; Univ Arizona (HINDAWI LTD, 2020-11-29)
      Objective. This retrospective cohort study is aimed at determining the safety and efficacy between Femoral Open-Cutdown access and Percutaneous access with Endovascular Aneurysm Repair (EVAR) by contrasting perioperative complication rates. We hypothesized that the percutaneous approach is a better alternative for aortic aneurysm patients as it is minimally invasive and has been demonstrated to decrease the length of hospital stay. Methods. We retrospectively reviewed data for patients undergoing EVAR between the years of 2005 and 2013. We then compared overall mortality, hematoma or seroma formation, graft infection, arterio-venous injury, distal embolization, limb loss, myocardial infarction or arrhythmia, and renal dysfunction. Results were demonstrated using a retrospective cohort study design to confirm the hematoma rate associated with EVAR open compared to percutaneous access. Results. Our series involves 73 patients who underwent percutaneous access for EVAR (n=49) or traditional open cutdown (n=24). Percutaneous access resulted in significantly less hematoma formation when compared to the traditional open cutdown (4% vs. 12.5%; p<0.059). Our analysis suggests decreased mortality rates associated with EVAR as compared to the Open-Cutdown method using Northside Medical Center's Study and the OVER Veterans Affairs Cooperative Study (p=0.0053). Conclusion. Percutaneous access for EVAR is safe and effective when compared to Open-Cutdown access for aortic aneurysm patients. Percutaneous access was associated with decreased rates of in-hospital mortality, hematoma formation, graft infection, and respiratory failure.
    • Cutaneous Metastasis in the Setting of Both Colon and Breast Primary Malignancies

      Junak, Mary; Jecius, Hunter; Erdrich, Jennifer; Univ Arizona, Dept Surg (HINDAWI LTD, 2020-09-29)
      Colorectal cancer (CRC) is the third most diagnosed cancer in the United States, and many patients unfortunately have metastases at the time of their diagnosis. Cutaneous metastases of CRC have been reported in few journals and primarily as case reports due to their rarity. Here, we present the case of an 83-year-old woman with recently resected colon cancer, T4aN1bMx stage IIIB. She presented to our clinic for evaluation of a right midback mass, and a punch biopsy revealed dermal involvement by invasive, poorly differentiated carcinoma with epidermoid features. The mass was excised, and we ordered a PET scan in search of the primary tumor, which at that time was suspected to be of skin cancer origin. Surprisingly, this revealed a second malignancy triple-negative invasive ductal carcinoma of the left breast. The back mass stained positive for CK20, which was compatible with a metastasis from a colonic primary. After initially declining adjuvant therapy, the patient completed one cycle of capecitabine and oxaliplatin, which she tolerated poorly. She continued to further decline, developed widespread cutaneous metastases, and went home on hospice. Cutaneous lesions are an exceedingly rare site of metastasis for colon adenocarcinoma, and their clinical presentation can vary widely. It is important for providers to investigate any new skin lesion in a patient with a recent or remote history of malignancy, even if there were no sites of distant metastasis at initial diagnosis.
    • Depression Treatment among Adults with Multiple Sclerosis and Depression in Ambulatory Care Settings in the United States

      Bhattacharjee, Sandipan; Goldstone, Lisa; Ip, Queeny; Warholak, Terri; Univ Arizona, Coll Pharm, Dept Pharm Practice & Sci; Department of Pharmacy Practice and Science, College of Pharmacy, The University of Arizona, Tucson, AZ, USA; Department of Pharmacy Practice and Science, College of Pharmacy, The University of Arizona, Tucson, AZ, USA; Department of Pharmacy Practice and Science, College of Pharmacy, The University of Arizona, Tucson, AZ, USA; Department of Pharmacy Practice and Science, College of Pharmacy, The University of Arizona, Tucson, AZ, USA (HINDAWI LTD, 2017)
      Background. There is little information regarding depression treatment patterns among adults with MS and depression in ambulatory settings at national level in the United States (US). Objectives. The objectives of this study were to identify patterns and predictors of depression treatment in ambulatory settings in US among adults with MS and depression. Methods. A cross-sectional study was conducted by pooling multiple years (2005-2011) of National Ambulatory Medical Care Survey and the outpatient department of the National Hospital Ambulatory Medical Care Survey data. The final study sample was comprised of ambulatory visits among adults with MS and depression. Dependent variable of this study was pharmacological treatment for depression with or without psychotherapy. Predictors of depression treatment were determined by conducting multivariable logistic regression. Results. Out of all ambulatory visits involving MS diagnosis, 20.59% also involved a depression diagnosis. Depression treatment was observed in 57.25% of the study population. Fluoxetine was the most prescribed individual antidepressant. Age and total number of chronic diseases were significant predictors of depression treatment. Conclusion. Approximately six out of ten ambulatory visits involving MS and depression recorded some form of depression treatment. Future longitudinal studies should examine health outcomes associated with depression treatment in this population.
    • Development and Validation of a Decision-Making Stratification Algorithm to Optimize the Use of Rapid Diagnostic Testing for Patients with Staphylococcus Bacteremia

      Almangour, Thamer A.; Alhifany, Abdullah A.; Tabb, Deanne E.; Univ Arizona, Coll Pharm, Dept Pharm Practice & Sci; Department of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, Chapel Hill, NC, USA; Department of Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson, AZ, USA; Columbus Regional Health, Midtown Medical Center, Columbus, GA, USA (HINDAWI LTD, 2017)
      Purpose. To evaluate whether introducing rapid diagnostic testing in conjunction with implementing a stratification algorithm for testing eligibilitywould be an appropriate clinical and cost saving approach. Method. An internal concurrent 4-month observational study was performed. Positive blood cultures continued to be worked up in accordance with standard of care. An additional call to the infectious disease (ID) pharmacy service occurred for all positive blood cultures with Gram-positive cocci in clusters (GPCC). The ID pharmacy service investigated each case using a prespecified stratification algorithm to minimize unnecessary use of rapid identification testing. Results. 43 patients with GPCC were screened. Only nine patients met inclusion criteria for QuickFISH (TM) testing. The average expected time avoided to optimize antibiotic therapy is 35 perpendicular to 16 hours. If the QuickFISH test had been indiscriminately implemented for all cases, the cost for performing this test would have been $5,590. However, using the prespecified algorithm, only 9 patients were tested for a projected cost of $1,170. Conclusion. Introducing rapid diagnostic testing in conjunction with implementing patient stratification algorithm for rapid identification of GPCC from blood cultures in addition to the ID pharmacy intervention will provide a positive impact on the clinical and economic outcomes in our health care setting.
    • Dilated Blood and Lymphatic Microvessels, Angiogenesis, Increased Macrophages, and Adipocyte Hypertrophy in Lipedema Thigh Skin and Fat Tissue

      AL-Ghadban, Sara; Cromer, Walter; Allen, Marisol; Ussery, Christopher; Badowski, Michael; Harris, David; Herbst, Karen L.; Univ Arizona, Coll Med, Dept Med; Univ Arizona, Coll Med, TREAT Program; Univ Arizona, Coll Med, Dept Immunobiol & Biorepository (HINDAWI LTD, 2019)
      Background and Aim. Lipedema is a common painful SAT disorder characterized by enlargement of fat primarily in the legs of women. Case reports of lipedema tissue samples demonstrate fluid and fibrosis in the interstitial matrix, increased macrophages, and adipocyte hypertrophy. The aims of this project are to investigate blood vasculature, immune cells, and structure of lipedema tissue in a cohort of women. Methods. Forty-nine participants, 19 controls and 30 with lipedema, were divided into groups based on body mass index (BMI): Non-Obese (BMI 20 to <30kg/m(2)) and Obese (BMI 30 to <40kg/m(2)). Histological sections from thigh skin and fat were stained with H&E. Adipocyte area and blood vessel size and number were quantified using ImageJ software. Markers for macrophages (CD68), mast cells (CD117), T cells (CD3), endothelial cells (CD31), blood (SMA), and lymphatic (D2-40 and Lyve-1) vessels were investigated by IHC and IF. Results. Non-Obese Lipedema adipocyte area was larger than Non-Obese Controls (p=0.005) and similar to Obese Lipedema and Obese Controls. Macrophage numbers were significantly increased in Non-Obese (p<0.005) and Obese (p<0.05) Lipedema skin and fat compared to Control groups. No differences in T lymphocytes or mast cells were observed when comparing Lipedema to Control in both groups. SMA staining revealed increased dermal vessels in Non-Obese Lipedema patients (p<0.001) compared to Non-Obese Controls. Lyve-1 and D2-40 staining showed a significant increase in lymphatic vessel area but not in number or perimeter in Obese Lipedema participants (p<0.05) compared to Controls (Obese and Non-Obese). Areas of angiogenesis were found in the fat in 30% of lipedema participants but not controls. Conclusion. Hypertrophic adipocytes, increased numbers of macrophages and blood vessels, and dilation of capillaries in thigh tissue of non-obese women with lipedema suggest inflammation, and angiogenesis occurs independent of obesity and demonstrates a role of altered vasculature in the manifestation of the disease.
    • Dorsoventral and Proximodistal Hippocampal Processing Account for the Influences of Sleep and Context on Memory (Re)consolidation: A Connectionist Model

      Lines, Justin; Nation, Kelsey; Fellous, Jean-Marc; Univ Arizona, Dept Psychol; Univ Arizona, Neurosci Grad Interdisciplinary Program; Univ Arizona, Program Appl Math; Department of Psychology, University of Arizona, Tucson, AZ 85721, USA; Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ 85721, USA; Department of Psychology, University of Arizona, Tucson, AZ 85721, USA (HINDAWI LTD, 2017)
      The context in which learning occurs is sufficient to reconsolidate stored memories and neuronal reactivation may be crucial to memory consolidation during sleep. The mechanisms of context-dependent and sleep-dependent memory (re)consolidation are unknown but involve the hippocampus. We simulated memory (re)consolidation using a connectionist model of the hippocampus that explicitly accounted for its dorsoventral organization and for CA1 proximodistal processing. Replicating human and rodent (re)consolidation studies yielded the following results. (1) Semantic overlap between memory items and extraneous learning was necessary to explain experimental data and depended crucially on the recurrent networks of dorsal but not ventral CA3. (2) Stimulus-free, sleep-induced internal reactivations of memory patterns produced heterogeneous recruitment of memory items and protected memories from subsequent interference. These simulations further suggested that the decrease in memory resilience when subjects were not allowed to sleep following learning was primarily due to extraneous learning. (3) Partial exposure to the learning context during simulated sleep (i.e., targeted memory reactivation) uniformly increased memory item reactivation and enhanced subsequent recall. Altogether, these results show that the dorsoventral and proximodistal organization of the hippocampus may be important components of the neural mechanisms for context-based and sleep-based memory (re)consolidations.
    • Effect of Real-Time Surveys on Patient Satisfaction Scores in the Emergency Department

      Sobel, Julia; Bates, Jessica; Ng, Vivienne; Berkman, Matthew; Nuño, Tomas; Denninghoff, Kurt; Stoneking, Lisa; Univ Arizona, Coll Med; Univ Arizona, Dept Emergency Med (HINDAWI LTD, 2019)
      Background. Patient satisfaction surveys have become increasingly important as their results help to determine Centers for Medicare and Medicaid Services (CMS) reimbursement. However, these questionnaires have known sources of bias (self-selection, responder, attribution, and nonresponse). Objective. We developed a real-time (RT) survey delivered in the hospital ED to evaluate the effect of implementing RT patient satisfaction surveys on physician behavior and hypothesized that the timing of patient satisfaction survey delivery would significantly impact the results. Method. Data from real-time patient satisfaction surveys were collected in phases from 12/2015 to 5/2017. Hospital-sponsored (HS) surveys were administered after discharge from 12/2015 to 12/2016. Results. For RT surveys, resident physicians were significantly more likely to write their names on the whiteboard (p = 0.02) and sit down (p = 0.01) with patients. Behavior modifications by attending physicians were not significant. Patient satisfaction measures did not improve significantly between periods for RT or HS surveys; however, RT survey responders were significantly more likely to recommend the ED to others. Conclusion. The timing of survey administration did significantly alter resident physician's behavior; however, it had no effect on patient satisfaction scores. RT responders were significantly more likely to recommend the emergency department to others.
    • Effects of Metamorphic Degree of Coal on Coal Dust Wettability and Dust-Suppression Efficiency via Spraying

      Wang, Pengfei; Han, Han; Liu, Ronghua; Li, Yongjun; Tan, Xuanhao; Univ Arizona, Dept Civil & Architectural Engn & Mech (HINDAWI LTD, 2020-03-30)
      Currently, spraying is a main means for dust prevention and control in underground coal mines. The dust-suppression efficiency via spraying is highly correlated with the wettability of coal dusts. There are many factors affecting the wettability of coal dust, among which coal's metamorphic degree has great influence. In order to gain in-depth knowledge of the effects of coal metamorphic degree on coal dust wettability and the dust-suppression efficiency via spraying, 6 coal dust samples with different metamorphic degrees were collected and used in the study. In the experiments, the microproperties, wetting performance, and dust-suppression efficiency via spraying were measured. According to the experimental results of coal's microproperties, with the improvement of metamorphic degree, the content of hydrophilic oxygen-containing functional groups on the surface, the surface roughness, the specific surface area, and the interpore diameter all decreased. In addition, as coal's metamorphic degree was enhanced from lignite to meager-lean coal, the wettability of the coal dust dropped. On the other hand, as the metamorphic degree of coal quality continued to be improved to anthracite, the wettability of the coal dust increased instead. The measured results revealed that the dust-suppression efficiency via spraying was highly correlated with the wettability of coal dust. The coal dust with better wettability exhibited higher dust-suppression efficiency via spraying. With the increase of water-supply pressure, the effect of coal dust wettability on the dust-suppression efficiency via spraying was weakened, and the difference of dust-suppression efficiency among different coal dust samples was narrowed.
    • Effects of Tobacco Smoke on Aeroallergen Sensitization and Clinical Severity among University Students and Staff with Allergic Rhinitis

      Songnuy, Theerapan; Scholand, Stephen J; Panprayoon, Sarawut; Univ Arizona, Dept Med (HINDAWI LTD, 2020-10-08)
      Allergic diseases, affecting a variety of organs, have continuously increased both in developed and developing countries. Tobacco smoke exposure increases prevalence of allergic rhinitis (AR) and may affect allergic sensitization. This study was designed to compare indoor-aeroallergen sensitization between those not exposed and exposed to tobacco smoke in university students and staff with allergic rhinitis. A cross-sectional descriptive study among university students and staff with allergic rhinitis was performed from February 1, 2018, to March 31, 2019. Questionnaires regarding demography, clinical symptoms, and tobacco smoke exposure were implemented. A current smoker was defined as using, at least, 1 cigarette per day for, at least, 1 month. A secondhand smoker was defined as the one who never smoked, but lived with a current smoker, at least, for 1 month. A skin prick test for eight common indoor aeroallergens, Dermatophagoides pteronyssinus, Dermatophagoides farinae, Periplaneta americana, cat dander, dog dander, para grass, careless weed, and Cladosporium spp., was performed. Sensitization was defined as positivity to, at least, 1 aeroallergen. One hundred and twenty-eight adult patients were eligible participants for the study, and 68 cases (53.10%) were classified as having tobacco smoke exposure. Among these, most of them were secondhand smokers (50 cases, 73.50%). There was no statistically significant difference between exposure and nonexposure to tobacco smoke and indoor aeroallergen sensitization, except for the Periplaneta americana antigen (p=0.013). Most of those in the nonexposure group (34 cases, 56.70%) were classified as having intermittent allergic rhinitis, whereas the tobacco exposure group had significantly more prevalence of severe clinical symptoms. In conclusion, tobacco smoke exposure did not appear to have much influence on aeroallergen sensitization for 7 of the 8 antigens examined. However, for the Periplaneta americana antigen, there was a highly significant correlation with patients experiencing worsened allergic rhinitis symptoms. Overall, it was observed that allergic rhinitis patients exposed to tobacco smoke had more severe clinical symptoms. Future studies should look for other potential antigens of interest, such as mould. Implementation of public health practices reducing exposure to tobacco smoke could have benefits in allergic rhinitis patients.
    • Experimental and Analytical Study on Seismic Behavior of Strengthened Existing Single Frame Structures with Exterior Cantilevers

      Hu, Bo; Wei, Xinyu; Lv, Henglin; Kundu, Tribikram; Li, Ning; Univ Arizona, Dept Civil Engn & Engn Mech, Dept Aerosp & Mech Engn (HINDAWI LTD, 2019)
      Three single reinforcement concrete (RC) frames, including 1 reference specimen and 2 specimens strengthened with shear walls, were fabricated and subjected to low cyclic loadings, in order to evaluate seismic performances of strengthened single frame structures with exterior cantilevers. Through comparison and analysis of failure mode, hysteretic behavior, skeleton curve, energy dissipation, strength, and stiffness degradation of the tested frames, the validity of the shear wall-based reinforcement method for single frames was verified. Test results indicate that the stiffness and load-bearing capacities of strengthened frames increased considerably in comparison with the reference frame. A strong column-weak beam failure pattern was observed on the cantilever side, and the failure of the shear wall was always prior to the column, which can increase the structural redundancy and improve the failure mechanism and seismic performance of an existing single frame.
    • Experimental Investigation on Failure Modes and Mechanical Properties of Rock-Like Specimens with a Grout-Infilled Flaw under Triaxial Compression

      Le, Huilin; Sun, Shaorui; Zhu, Feng; Fan, Haotian; Univ Arizona, Rock Mass Modeling & Computat Rock Mech Labs (HINDAWI LTD, 2019)
      Flaws existing in rock mass are one of the main factors resulting in the instability of rock mass. Epoxy resin is often used to reinforce fractured rock mass. However, few researches focused on mechanical properties of the specimens with a resin-infilled flaw under triaxial compression. Therefore, in this research, epoxy resin was selected as the grouting material, and triaxial compression tests were conducted on the rock-like specimens with a grout-infilled flaw having different geometries. This study draws some new conclusions. The high confining pressure suppresses the generation of tensile cracks, and the failure mode changes from tensile-shear failure to shear failure as the confining pressure increases. Grouting with epoxy resin leads to the improvement of peak strengths of the specimens under triaxial compression. The reinforcement effect of epoxy resin is better for the specimens having a large flaw length and those under a relatively low confining pressure. Grouting with epoxy resin reduces the internal friction angle of the samples but improves their cohesion. This research may provide some useful insights for understanding the mechanical behaviors of grouted rock masses.
    • Experimental Investigation on Fracture Evolution in Sandstone Containing an Intersecting Hole under Compression Using DIC Technique

      Wu, Hao; Zhao, Guoyan; Liang, Weizhang; Wang, Enjie; Ma, Shaowei; Univ Arizona, Dept Min & Geol Engn (HINDAWI LTD, 2019-04-07)
      Failure of underground structures, especially intersections, becomes more severe as the depth increases, which poses a new challenge for the safe construction and operation of deep rock engineering. To investigate the mechanical properties and fracture behavior of rock with an intersecting hole under compressive loads, a series of uniaxial compression tests was carried out on cuboid red sandstone specimens containing an intersecting hole with three types of shapes by digital image correlation (DIC) technique. The results showed that the existing hole inside specimens leads to almost a 50% reduction of mechanical parameters from that of intact ones, and this weakening effect is associated with the shapes of holes. Failure of specimens is a progressive process in which cracks, i.e., primary tensile cracks, secondary tensile cracks, and shear cracks, initiate from stress concentration zones, propagate along certain direction, and coalesce with each other into macrofractures. Both the real-time principal strain fields and horizontal displacement fields of specimens under compression could be visually displayed by DIC system, and they were in good consistency in characterizing the fracture behavior. Moreover, the propagation characteristics of primary tensile cracks were studied further by quantitatively analyzing the strain variation during the loading process, and the propagation mechanism of open-close-reopen of primary tensile cracks was explained in detail.
    • Experimental Study on the Mud-Water Inrush Characteristics through Rock Fractures

      Zhao, YanLin; Zhang, Lianyang; Univ Arizona, Dept Civil Engn & Engn Mech (HINDAWI LTD, 2018)
      Fractured rock masses, which are widely distributed in the south of China, have an impartible relationship with mud-water inrush. In order to study the change laws of mud viscosity under different moisture content, flow property, and mechanism of mud-water inrush in fractured rock masses, a NDJ-8S rotary viscometer and a simulation model are used to carry out a series of experimental studies. Tests of mud viscosity show that mud viscosity depends on moisture content, and the relationship between viscosity and moisture content was proposed. Based on mud viscosity results, physical model tests' results indicated that the process of mud-water rush can be divided into four stages: that is, the preparation stage of mud-water mixture burst, the seepage period of mudwater mixture inrush, the nonstable period of mud-water mixture outburst, and the stable period of mud-water mixture outburst. The excavation disturbance, high water pressure, and effect of erosion and corrosion of water were identified as key factors which lead to mud-water inrush in fractured rock masses.
    • An Experimental Study on Wetting of Coal Dust by Surfactant Solution

      Jiang, Yidan; Wang, Pengfei; Liu, Ronghua; Pei, Ye; Wu, Gaogao; Univ Arizona, Dept Civil & Architectural Engn & Mech (HINDAWI LTD, 2020-03-31)
      Surfactants can improve the wetting performance of the dust-reduction spraying water, thus improving the dust-reduction effect by spray. In this study, the performance of surfactant solution in wetting coal dust was investigated through experiments. In addition, the effects of surfactant type, mass fraction, metamorphic degree of coal, particle size, and additives were investigated. According to the results of surface tension experiments, the surface tension of the solution decreased with the increase of the concentration of surfactant. However, after reaching CMC, the surface tension did not have significantly decrease. SDBS and OP-10 had higher efficiency in decreasing the surface tension than the other two types of surfactants. The addition of sodium sulfate additives can further reduce the surface tension of the surfactant solution by a limited range. The coal dust wetting experiment showed that with the increase in the concentration of the surfactant, the contact angle of the droplets on the coal dust tablet was continuously reduced, and the wettability of the solution was continuously improved. The wettability of the OP-10 solution was optimal. At the same concentration, the minimum contact angle can be obtained in the OP-10 solution. As the contact angle of the coal dust increased, the growth rate in the coal dust reverse osmosis moisture absorption of the surfactant solution relative to the pure water increased. After the addition of sodium sulfate, the reverse osmosis moisture absorption of coal dust increased to varying degrees. In addition, as the concentration of additives increased, the moisture absorption of coal dust increased.