Frequent Component Research Articles

Mining Query Plans for Finding Candidate Queries and Sub-Queries for Materialized Views in BI Systems Without Cube Generation

Materialized views are important for optimizing Business Intelligence (BI) systems when they are designed without data cubes. Selecting candidate queries from large number of queries for materialized views is a challenging task. Most of the work done in the past involves finding out frequent queries from the past workload and creating materialized views from such queries by either manually analyzing workload or using approximate string matching algorithms using query text. Most of the existing methods suggest complete queries but ignore query components such as sub queries for creation of materialized views. This paper presents a novel method to determine on which queries and query components materialized views can be created to optimize aggregate and join queries by mining database of query execution plans which are in the form of binary trees. The proposed algorithm showed significant improvement in terms of more number of optimized queries because it is using the execution plan tree of the query as a basis of selection of query to be optimized using materialized views rather than choosing query text which is used by traditional methods. For selecting a correct set of queries to be optimized using materialized views, the paper proposes efficient specialized frequent tree component mining algorithm with novel heuristics to prune search space. These frequent components are used to determine the possible set of candidate queries for creation of materialized views. Experimentation on standard, real and synthetic data sets, and also the theoretical basis, proved that the proposed method is able to optimize a large number of queries with less number of materialized views and showed a significant improvement in performance compared to traditional methods.

Cancer-associated fibroblasts in epithelial ovarian carcinoma: relation to clinicopathologic characteristics and microvessel density

Background Epithelial ovarian carcinoma (EOC) is the leading cause of mortality among all gynecologic cancers. Recent studies have emphasized the role of the tumor microenvironment in tumor progression. Cancer-associated fibroblasts (CAFs) are the most frequent component in the tumor microenvironment, and α-smooth muscle actin (α-SMA) is the most commonly used marker to identify CAF. This study aimed to investigate the potential role of CAFs in the progression of EOC. Furthermore, we analyzed the relation between the presence of CAF in EOC and clinicopathologic characteristics and tumor microvessel density (MVD). Methods Immunohistochemical staining was performed on 75 cases of epithelial ovarian neoplasms using α-SMA (as a marker of CAFs) and CD34 (for assessment of MVD in EOC cases). Results The presence of CAFs, as assessed by α-SMA intensity and percentage of positive stained area, was significantly more prominent in malignant cases, as compared with borderline and benign cases. It was found that abundant CAFs were significantly associated with high-grade tumors, stage III tumors and tumors with vascular invasion and omental metastasis. A significant positive correlation was detected between the presence of CAFs and tumor MVD in EOC. Conclusion CAFs significantly increase from benign through borderline to malignant ovarian neoplasms. CAFs are significantly higher in high-grade tumors, advanced stage tumors and in tumors with vascular invasion or omental metastasis. CAFs are significantly correlated with tumor MVD in EOC. Thus, CAFs may serve as a poor prognostic indicator in patients with EOC.

Prevalence of Metabolic Syndrome and Its Components among Saudi Young Adults 18 - 30 Years of Age

Background: Metabolic syndrome (MS) is a cluster of established cardiovascular risk factors that collectively increase predisposition to major chronic diseases, including heart diseases and diabetes mellitus. Young adults can be affected by MS or any of its components which predispose them to its complications later in their life. Hence early detection of MS and its components can be of help in preventing or controlling its adverse consequences among young adults. Materials and Methods: A total of 1354 Saudis aged 18 - 30 was randomly selected from 20 regions in the Kingdom of Saudi Arabia (KSA). Anthropometrics were collected, and fasting blood samples were collected to ascertain fasting blood glucose and lipid profile. Components of full MS and its components according to the International Diabetes Federation (IDF) were used in this study. Results: Metabolic syndrome prevalence was 12% and was significantly higher among males, advancing age and government employees and unemployed subjects but not according to income or education levels MS was significantly higher among current smokers, subjects with low physical activity level, but not significant according to dietary habits in terms of combined fruits and vegetables consumption. Low levels of High Density Lipoprotein (HDL) were the most frequent component in both males and females. Both waist circumference (WC) and low levels of HDL were much higher among females. Significant predictors included male gender, advancing age, lower level of physical activity and current smoking. Conclusion: The prevalence of MS is 12% in young adults. Low HDL is the most prevalent component of MS in young adults and thus may also be the first detectable component of MS in many young adults. Early identification of MS components could lead to targeted interventions to prevent the development of the syndrome, and thus reduce cardiovascular disease risk in later life.

Десемантизация древнетюркских элементов xan,baj, beg, в cовременных казахских антропонимах

The lexemes khan, bai, bek of Old Turkic origin are frequent components in modern Kazakh masculine name compounds such as Abilkhan, Adilbek, Kumisbay, etc. During centuries of development with the aforementioned Old Turkic common words denoting a person’s high social, class and material status in Kazakh society, various semantic changes took place. Of particular interest to us are the processes that take place in their semantics when they function as part of the complex masculine name composites. The most important factor that has influenced the dynamics of semantic processes in these words is an extra-linguistic factor: a change in the socio-economic structure of Kazakh society that led to the loss of statuses, titles and ranks. As a result, the old Turkish nouns became historicisms, which lost their referential and thus also part of their denotative meaning. The second, purely linguistic factor was the semantic-grammatical nature of the first component of the compound name, which also significantly determined the processes in the semantics of the Old Turkic elements. Thus, in the complex two-part names with the first component – the name of a person according to a certain parameter – there is an additional desemanticisation of the Old Turkic elements due to the semantic redundancy (the repetition of the sem «person»), for example: Zholdaskhan, Dosbay. In combination with the animal names, these elements actualise the semes ‘man’, ‘baby’, ‘male’, having an identifying rather than a nominative function and therefore becoming a unit of the transitional type affixoid. In combination with the toponyms, numerals and adjectives, the old Turkic elements are desemanticised, undergo the process of affixoidisation and now function as signs for the name of a male person. The desemanticisation of the listed Old Turkic elements contributed to their preservation in the active fundus of the Kazakh language in a new, identifying function as part of complex anthroponyms.

Impact of components of metabolic syndrome on the prostatic volume and lower urinary tract symptoms in a sample of patient with benign prostatic hyperplasia in Iraq

Objective To evaluate the association between the components of metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) focusing at their effects on prostatic volume and on the severity of LUTS . Patients & Methods From October 2016 to January 2018, eighty patients presented with LUTS due to the BPH. LUTS were assessed using the international prostatic symptoms score (IPSS) and MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III guidelines. Patients were randomly collected into two categories: A (48 patients) had MetS and B (32 patients) without MetS. Results The mean age was 64.3 years, statistically significant variation was identified between the two categories regarding the moderate and severe IPSS, S.PSA, prostatic size and post voiding residue (PVR), the P value (<0.05). The most frequent MetS components were: hypertension in 65/80 patients (81.25%), high fasting glucose in 49/80 patients (61, 25%), and waist circumference elevation in 55/80 patients (68.75%). The association between MetS components, the prostatic volume and severity of LUTS had shown that all MetS components except HDL-cholesterol were significantly correlated with higher prostatic volume (P < 0.05). Also a positive statistically significant association was discovered between each component of MetS and higher IPSS, excepting HDL-cholesterol (P = 0.93) and triglyceride (P = 0.58). Conclusion The results of the present study confirmed that there is a significant relation between the components of metabolic syndrome, the increase in prostatic volume and the severity of LUTS/BPH.

Učestalost i značaj metaboličkog sindroma i njegovih komponenata u ambulantnih pacijenata

Introduction: Metabolic syndrome (MS) is a group of cardiovascular risk factors including hyperglycemia, elevated blood pressure, elevated triglycerides levels, central obesity, and low HDL cholesterol. Population studies results show MS to be useful in predicting cardiovascular morbidity and mortality. Objective: Examine the frequency and importance of metabolic syndrome and its components in outpatients. Methods: The study included 178 (71.26±8.93) outpatients, selected by random sample, 67 (71.24±9.5) men and 111 (71.28±11.29) women (p>0.05). Nutrition status was estimated based on anthropometric parameters (body height, body weight, waist circumference). Glycemia, HDL cholesterol, triglycerides, and blood pressure values were measured in all participants. The criteria of the American Heart Association (AHA/NHLBI) were used to diagnose MS. Results: MS was diagnosed in 42.7% of the patients, 31.6% of men and 68.4% of women. The incidence of MS was higher in women (47.7%) than men (35.8%) (p>0.05). In subjects with MS, three components were found in 51.3%, four components in 42.1% and five in 6.6%. Considering individual MS components, the increased waist circumference had the highest incidence of 92.1%. Among the patients with coronary heart disease (CHD), 10.2% had MS, and among those without MS only 1.96% (p<0.01). During the observation period, 10.5% of patients with MS died, compared to the group without MS, where 0.98% died (p<0.01). Conclusion: The incidence of the metabolic syndrome among the outpatients in our group was 42.7%, of whom 35.8% were men and 46.8% were women. Increased waist circumference was the most frequent individual MS component among the participants. Patients with metabolic syndrome have got a significantly higher incidence of coronary artery disease and mortality rates, compared to those without MS, which indicates MS is an important risk factor for the occurrence and development of the coronary heart disease. The patients with MS have got a worse medical prognosis and that's why they should have regular checkups, for the sake of primary and secondary prevention.

Application of Policy Analysis Models in Oral Health Issues: A Review.

Introduction:Oral health is a complex interaction that contains factors such as disease status and physiological and psychosocial properties. Because of complexity of the health system, policymakers should find some ways to simplify the relations to increase the chance of understanding the conditions, values, and ideas behind it. Policy learning could be built on the appropriate policy models application corn stone. The aim of this study was to answer this question that what policy models were applied in oral health policy studies and what oral health policy issues were analyzed by policy models.Materials and Methods:A systematic review was conducted across international electronic databases (PubMed, ISI Web of Knowledge, and Scopus) with no time limitation and using prearranged keywords. All publications such as articles and thesis were included. Searched terms were selected based on frequent health policy model components and an initial search. Search strategy based on each data base instruction was applied.Results:Eight models or frameworks were applied in total. Most of these models were focused on process stage of oral health policy making. Five main themes such as the role of stakeholders in oral health policy making, assessment of oral health system, oral health policy development, the process of oral health policy making, and oral health policy learning and capacity building were synthesized.Conclusion:Oral health policy issues could be analyzed more comprehensively, and researchers could be guided by applying policy models and frameworks to answer policy-learning questions. Application of models and frameworks should be based on the nature of problem and issue, and the level of problem screening is a critical point in applying appropriate model.

Психологические риски и окончание карьеры при получении травмы в спорте высших достижений: разбор случаев

The paper presents the psychological aspect of sports injury in high performance sport. The significance of injury manifests itself in the disruption of everyday life, pain, discomfort, and stress, as well as the accompanying existential experiences. On the one hand, injury appears to be a routine and frequent component of the sports profession; on the other hand, its importance is enormous, and an injured athlete can end his/her professional trajectory without being able to become successful and prosperous in life outside of sport. The work emphasized four cases from the authors’ practice. They demonstrate that a high level of perfectionism and internality in the experience of injury can manifest itself in self-blame and internal conflict; successful post-traumatic growth requires a supporting environment. We indicate the importance of an interdisciplinary approach to intervention when all the key specialists and the close ones are involved in the psychological recovery of an athlete.

Solitary ganglioneuroma of the oropharynx

Mucosal neuromas, or ganglioneuromas, attract attention as a frequent component of multiple endocrine neoplasia (MEN) syndrome type 2B. The paper describes a clinical and morphological case of solitary oropharyngeal ganglioneuroma in a 60-year-old man, whose observation has not revealed its apparent association with the MEN syndrome.

Is there an appropriate strategy for treating co-morbid irritable bowel syndrome and bladder pain syndrome?

ABSTRACTIntroduction: Two of the most frequent components of chronic pelvic pain syndrome (CPPS) are irritable bowel syndrome (IBS) and bladder pain syndrome (BPS), characterized by considerable overlapping symptoms and pathophysiology. Currently, its management is challenging meaning there is high the demand for novel efficient therapeutics to aid patient care and to tackle the socioeconomic burden of IBS and BPS. As there are presently no sufficient treatment strategies, identifying the mechanisms that result in their main symptoms is the opportunity for developing appropriate therapies.Areas covered: Herein, the authors explore the potential common treatment strategies for co-morbid IBS and BPS and highlight the absolute need for further research of these deliberating clinical entities.Expert opinion: In the future, the authors summise that the discovery of predictive molecular biomarkers combined with clinical phenotypic categorization will likely allow for more definitive differentiation of patients and thus for better treatment options. Furthermore, it has been suggested that effective IBS treatment strategies would be of great value to co-morbid IBS and BPS therapy.

Transport and Charge Carrier Chemistry in Lithium Sulfide

AbstractLithium sulfide is a functional material of great importance for battery research, since it is the discharge product in Li–S cathodes and a frequent component of anode passivation layers. In both cases, transport of charge carriers in Li2S is critical for performance. The exploration of charge carrier chemistry in such a simple binary compound is also of fundamental scientific interest. For that purpose, impedance spectroscopy and electromotive force measurements are performed over a broad range of temperatures and doping conditions. The results indicate predominant ion conduction and can be quantitatively explained by a defect chemical model based on Frenkel disorder and vacancy‐dopant association. Mobilities and migration barriers for both vacancy and interstitial defects are deduced. The thermodynamic and kinetic parameters derived for Li+ transport in antifluorite Li2S show remarkable agreement with the analogous parameters for F− transport in fluorite compounds such as BaF2, thereby improving the structural understanding of charge carrier chemistry in such compounds. An application of these results to passivation layers in solid state batteries is also discussed.

An Experimental Comparison of the Effect of Teacher Versus Self-Evaluation/Self-Reflection Feedback on College Students’ Behavioral Observation Skills

An experimental investigation of the effectiveness of two types of feedback on college students’ acquisition of behavioral observation skills was conducted. Special education and psychology students completed two training assignments involving behavioral observations of students engaging in problem behavior. Depending on the condition to which they were randomly assigned, participants experienced either teacher or self-evaluation/self-reflection feedback immediately after each assignment was completed. Participants in the teacher feedback condition scored higher on the post-training assignments and viewed it more positively than those in the self-evaluation/self-reflection condition. Additional research is needed to identify the relevant variables contributing to effective teacher feedback since it is a frequent component of instructional situations.

Cube Designs in Roman Baetica Mosaics

The cube and the prism are frequent components of geometrical compositions featured in Roman mosaics. They can be found as free elements belonging to the secondary decoration of many pavements, or as part of friezes or mosaic panels, sometimes mixed with other geometrical figures to shape various compositions and sometimes used as exclusive motifs and single theme, forming unitary and/or modular panels. This paper will focus on the latter.In our catalogue of Geometrical Designs, these modular compositions with three-dimensional cubes or “tumbl- ing blocks” and with elongated cubes or prisms define models E3 and E3A respectively. Even though these are present in a significant number of pavements in the Roman Baetica, we cannot assume their widespread use since they are so far absent from sit es with a well-established mosaic tradition, such as Italica, Hispalis or Carmo. In contrast, Astigi and Corduba are the cities where more pavements with these designs have been found.In this paper we will also analyse the process of development of both models, and how these compositions, dominant and solid by their own characteristics despite the sense of movement they transmit, can produce diverse effects and create different optical perceptions by simply changing the point of view from which they are observed or with a slight colour change. This last aspect is essential to allow the design its main feature, which relates to a three-dimensional effect.

Sensitivity of streamflow simulation in the Delaware River Basin to forecasted land‐cover change for 2030 and 2060

AbstractIn order to simulate the potential effect of forecasted land‐cover change on streamflow and water availability, there has to be confidence that the hydrologic model used is sensitive to small changes in land cover (&lt;10%) and that this land‐cover change exceeds the inherent uncertainty in forecasted conditions. To investigate this, a 26‐year streamflow record was simulated for 33 basins (54–928 km2) in the Delaware River Basin using three dates of land cover: the 2011 National Land‐Cover Dataset (Homer, Fry, &amp; Barnes, ), 2030 land‐cover conditions representing median values from 101 equally‐likely forecasts, and 2060 land‐cover conditions corresponding to the same iterations used to represent 2030. Streamflow was simulated using a process‐based hydrologic model that includes both pervious and impervious methods as parameterized by three land‐cover‐based hydrologic response units (HRUs)—forested, agricultural, and developed land. Small, but significant differences in streamflow magnitude, variability, and seasonality were seen among the three time periods—2011, 2030, and 2060. Temporal differences were discernible from the range of conditions simulated with 101 equally likely forecasts for 2030. Development was co‐located with the most frequent landscape components, as characterized by topographic wetness index, resulting in a change in hydrology for each HRU, highlighting that knowing the location of disturbance is key to understanding potential streamflow changes. These results show that streamflow simulation using regional calibration that incorporates land‐cover‐based HRUs can be sensitive to relatively small changes in land‐cover and that temporal trends resulting from land‐cover change can be isolated in order to evaluate other changes that might affect water resources.

Metabolic Syndrome in Female Patients with Acute Myocardial Infarction

Introduction and objectives: A large proportion of patients with coronary disease have metabolic syndrome. The purpose of this research was to assess the association between the metabolic syndrome (MetS) and acute myocardial infarction in female patients.Methods: This was a case control study. Patients with a first time cardiac event of acute myocardial infarction (AMI) arriving in coronary care unit of Rajshahi Medical College Hospital, Rajshahi, Bangladesh during the period June 2013 to July 2014 were included. Metabolic syndrome and its five components were defined according to criteria set by Adult Treatment Plan III (NCEP ATP III) criteria. Blood sugars, triglycerides, HDL-C were measured within 24hrs of cardiac insult. Hypertension was defined as blood pressure ≥ 130/≥85 mmHg. Abdominal obesity measured by waist circumference which is defined for Asia-Pacific region as ≥ 80 cm for women.Results: Total 103 female patients were evaluated. Mean age was 54.28 ±11.78 and acute myocardial infarction was more in age group 50-59 (34%). More than 60% patients suffering from acute myocardial infarction was age group 40-60 years. The metabolic syndrome was present in 74 (71.8%) female patients with acute myocardial infarction and was more frequent in women than in men (71.8% vs 37.9%, P&lt;.001). The most prevalent component was low HDL-C (n 76; 73.8%), followed by fasting plasma glucose level (n 73; 70.9%).Conclusions: The metabolic syndrome has a high prevalence in female patients with acute myocardial infarction. The most frequent components are low HDL-C levels and fasting plasma glucose level.TAJ 2013; 26: 74-78

Control of Carbapenem-resistant Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa in Healthcare Facilities: A Systematic Review and Reanalysis of Quasi-experimental Studies.

Carbapenem-resistant Enterobacteriaceae (CRE), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPsA) are a serious cause of healthcare-associated infections, although the evidence for their control remains uncertain. We conducted a systematic review and reanalysis to assess infection prevention and control (IPC) interventions on CRE-CRAB-CRPsA in inpatient healthcare facilities to inform World Health Organization guidelines. Six major databases and conference abstracts were searched. Before-and-after studies were reanalyzed as interrupted time series if possible. Effective practice and organization of care (EPOC) quality criteria were used. Seventy-six studies were identified, of which 17 (22%) were EPOC-compatible and interrupted time series analyses, assessing CRE (n = 11; 65%), CRAB (n = 5; 29%) and CRPsA (n = 3; 18%). IPC measures were often implemented using a multimodal approach (CRE: 10/11; CRAB: 4/5; CRPsA: 3/3). Among all CRE-CRAB-CRPsA EPOC studies, the most frequent intervention components included contact precautions (90%), active surveillance cultures (80%), monitoring, audit and feedback of measures (80%), patient isolation or cohorting (70%), hand hygiene (50%), and environmental cleaning (40%); nearly all studies with these interventions reported a significant reduction in slope and/or level. The quality of EPOC studies was very low to low.

Frequency of metabolic syndrome and associated factors in institutionalized elderly individuals.

IntroductionPopulation aging generally accompanies an increase in chronic noncommunicable diseases, such as metabolic syndrome (MS). Nursing homes have provided a solution for the decreased ability of elderly individuals for self-care and familial difficulties in meeting the health care needs of elderly individuals.PurposeThe aim of the present study was to determine the frequency of MS and its associated factors in elderly individuals living in nursing homes.Patients and methodsThis cross-sectional study was conducted with 202 institutionalized elderly individuals. MS was diagnosed according to the National Cholesterol Education Program – Adult Treatment Panel III criteria. Sociodemographic, clinical, and lifestyle factors were assessed to verify their association with MS by logistic regression.ResultsThe MS frequency was 29.2%. The most frequent MS components were low high-density lipoprotein cholesterol level (63.9%) and abdominal obesity (42.7%). Factors associated with MS were female sex (prevalence ratio [PR]=2.16; 95% CI, 1.04–4.49), age-adjusted institutionalization time >50% (PR=2.38, 95% CI, 1.46–3.88), and high concentrations of interleukin-6 (PR=2.01; 95% CI, 1.21–3.32) and tumor necrosis factor-α (PR=1.70; 95% CI, 1.05–2.77). Moreover, it was verified that the likelihood of having MS was 1.85-fold higher (95% CI, 1.11–3.10) in the group with a diet characterized by very high energy, very low fat, and high dietary fiber.ConclusionThe occurrence of MS in institutionalized elderly individuals was higher in females, and individuals with longer age-adjusted institutionalization time, higher concentrations of immunologic biomarkers, and a dietary intake consisting of higher energy and fiber and lower total fat. The results of the study are useful for guiding health care programs aimed at institutionalized elderly individuals.

Patterns of Cardiometabolic Health as Midlife Women Transition to Menopause: A Prospective Multiethnic Study.

Cardiometabolic conditions increase in midlife, but early customized prevention strategies are not established for such women. To characterize and identify factors longitudinally related to constellations of cardiometabolic risk components in multiracial/ethnic women in midlife. We conducted a prospective, longitudinal, multiethnic cohort study of 3003 midlife women undergoing menopausal transition (MT). Metabolic syndrome (MetS) was defined as having at least three of five components: high fasting triglyceride (hTG) level, low high-density lipoprotein cholesterol (lHDL-C) level, high fasting plasma glucose (hGluc) level, large waist circumference (abdominal obesity; Ob), and hypertension (HTN). We described the patterns of constellations and estimated hazard ratios (HRs) for constellations at (i) incident MetS and (ii) recovery from MetS, using multivariable-adjusted Cox regression. Seven US sites. In all, 1412 non-Hispanic white, 851 black, 272 Japanese, 237 Hispanic, and 231 Chinese women. Race/ethnicity, lifestyle factors, and MT stage. Cardiometabolic constellations, incident MetS, and MetS recovery. Central obesity was the most frequent component. Having no components was the most frequent (31%) baseline constellation. Physical activity (HR = 1.68; 95% CI: 1.06, 2.68) and lower caloric intake (HR = 0.96; 95% CI: 0.93, 0.99 per 100 cal/d) were associated with recovery from MetS. Ob/hTG/lHDL-C (18%), Ob/HTN/lHDL-C (16%), and Ob/HTN/hGluc (14%) were frequent incident constellations. Physically active women had 26% to 62% lower hazards of incident MetS than inactive women. Modifiable lifestyle behaviors were related to recovery from MetS and decreased risk of the most frequent MetS constellations in midlife women.

Prevalence of Metabolic Syndrome and Its Components in Workers of a High-Level Educational Institution, Cartagena-Colombia

To determine the prevalence of metabolic syndrome, components and their relationship in workers of a higher education institution of Cartagena-Colombia. An analytical cross-sectional study was carried out, with a probabilistic sample of 162 workers in a higher education institution. Sociodemographic data were recorded, physical examination including abdominal circumference, blood pressure, height, weight, as well as clinical tests of lipid laboratory (total cholesterol, HDL cholesterol and triglycerides) and fasting glycemia determined by colorimetric and enzymatic methods. The parameters established by the American Heart Association-AHA were used to identify metabolic syndrome. A prevalence of metabolic syndrome of 11.1% was estimated. The most frequent components among individuals with metabolic syndrome were: increase in abdominal circumference (83.3%), hypertriglyceridemia (66.7%) and low levels of HDL-c (50.0%). The elevation of the abdominal perimeter was the most frequent component. No statistical evidence of association between any of the components of the syndrome was found. These evidences suggest to improve the life habits of the workers evaluated, in terms of their nutrition and physical activity.

Metal Exposure from E-Cigarette Users in Maryland

BackgroundAs more is known about the components of electronic cigarettes (e-cigarettes), it is important to characterize metal exposure from use. Nickel (Ni) and chromium (Cr) are frequent components of e-cigarette heating coils and have been found in e-liquid and aerosol. We compared Ni and Cr biomarker concentrations among Maryland e-cigarette users to that of non-e-cigarette users/non-smokers, and also assessed the association of e-cigarette use patterns with metal biomarker concentrations.MethodsWe recruited 50 e-cigarette users and 50 non-e-cigarette users from March to October 2017. Data were collected on health status, e-cigarette use patterns, device characteristics, sociodemographic factors. Urine, saliva, and exhaled breath condensate (EBC) samples were collected. Metal concentrations were measured using ICP-MS.ResultsThe median Cr concentrations for non-users and e-cigarette users were 0.92 and 1.77 &amp;#956;g/l in urine, 0.62 and 0.73 &amp;#956;g/l in saliva, and both 0.14 &amp;#956;g/l in EBC, respectively; median Ni concentrations were 0.68 and 1.11 &amp;#956;g/l in urine, 0.27 and 0.55 &amp;#956;g/l in saliva, and both 0.13 &amp;#956;g/l in EBC. Compared to non-users, e-cigarette users had significantly higher levels of Ni concentration in urine (GMR 3.99, 95% CI: 1.95-8.19, p &amp;lt; 0.001). Increased urine Ni concentrations were observed among users who vaped at a higher voltage (3.65-4.20 volts) and used a higher nicotine concentration (12-24 mg/ml). Saliva Cr concentrations were increased with more e-liquid consumed per week (35 to 60 ml). Both Ni and Cr saliva concentrations were increased among users that changed their coils more frequently (&amp;gt;2/month).ConclusionE-cigarette users had significantly higher levels of Cr in urine than non-users. Ni in urine and Cr in saliva were positively associated with higher e-cigarette use and voltage. Increased metal concentrations in saliva associated with more frequent coil change provide an indication that instructions and best practice of using coils is warranted.