Constrained K-means and Genetic Algorithm-based Approaches for Optimal Placement of Wireless Structural Health Monitoring Sensors

Optimal placement of wireless structural health monitoring (SHM) sensors has to consider modal identification accuracy and power efficiency. In this study, two-tier wireless sensor network (WSN)-based SHM systems with clusters of sensors are investigated to overcome this difficulty. Each cluster contains a number of sensor nodes and a cluster head (CH). The lower tier is composed of sensors communicating with their associated CHs, and the upper tier is composed of the network of CHs. The first step is the optimal placement of sensors in the lower tier via the effective independence method by considering the modal identification accuracy. The second step is the optimal placement of CHs in the upper tier by considering power efficiency. The sensors in the lower tier are partitioned into clusters before determining the optimal locations of CHs in the upper tier. Two approaches, a constrained K-means clustering approach and a genetic algorithm (GA)-based clustering approach, are proposed in this study to cluster sensors in the lower tier by considering two constraints: (1) the maximum data transmission distance of each sensor; (2) the maximum number of sensors in each cluster. Given that each CH can only manage a limited number of sensors, these constraints should be considered in practice to avoid overload of CHs. The CHs in the upper tier are located at the centers of the clusters determined after clustering sensors in the lower tier. The two proposed approaches aim to construct a balanced size of clusters by minimizing the number of clusters (or CHs) and the total sum of the squared distance between each sensor and its associated CH under the two constraints. Accordingly, the energy consumption in each cluster is decreased and balanced, and the network lifetime is extended. A numerical example is studied to demonstrate the feasibility of using the two proposed clustering approaches for sensor clustering in WSN-based SHM systems. In this example, the performances of the two proposed clustering approaches and the K-means clustering method are also compared. The two proposed clustering approaches outperform the K-means clustering method in terms of constructing balanced size of clusters for a small number of clusters. Doi: 10.28991/CEJ-2022-08-12-01 Full Text: PD

Effect of Auricular Acupressure on Peri- and Early Postmenopausal Women with Anxiety: A Double-Blinded, Randomized, and Controlled Pilot Study

We tested effects of auricular acupressure on peri- and early postmenopausal women with anxiety (PPWA). Fifty PPWA were randomly assigned to the auricular acupressure group (AG) or the sham group (SG). After 3 meals and before sleep every day for 4 weeks, the AG received auricular acupressure on the bilateral ear shenmen and subcortex points for 3 min per point on alternating ears. The SG received sham auricular acupressure. The Alprazolam was reduced from 0.5 mg/day at baseline to 0.3 mg/day 4 weeks after auricular acupressure (4 W) in the AG (P < .05) whereas maintained at 0.5 mg/day in the SG (P > .05). The Zolpidem was reduced from 3.0 mg/day at baseline to 1.5 mg/day at 4 W (P < .05) whereas was reduced from 2.4 mg/day to 1.9 mg/day at 4 W in the SG (P > .05), thus, significant tapering medication, suggesting auricular acupressure is helpful to PPWA

Well-differentiated gall bladder hepatoid carcinoma producing alpha-fetoprotein: a case report

<p>Abstract</p> <p>Introduction</p> <p>Gall bladder carcinoma is rare, and metastatic gall bladder carcinoma from hepatocellular carcinoma has been reported in only a few patients.</p> <p>Case presentation</p> <p>We present a 73-year-old man with a history of hepatitis B virus-related liver cirrhosis and hepatocellular carcinoma. He received transcatheter arterial chemoembolization, and was diagnosed to have an alpha-fetoprotein producing gall bladder tumor with intraluminal growth. Open cholecystectomy was performed. Pathologic examination of the lesion revealed a well-differentiated hepatoid carcinoma. The lesion was thought most likely to be a metastatic lesion from previous hepatocellular carcinoma. His alpha-fetoprotein level dropped to normal levels five months after the surgery.</p> <p>Conclusion</p> <p>This unusual intraluminal growing tumor proved to be a well-differentiated hepatoid carcinoma, most likely a metastatic lesion from previous hepatocellular carcinoma. This case reminds clinicians that in looking for likely hepatocellular carcinoma recurrence, when no detectable hepatic lesion can account for an elevated alpha-fetoprotein level, the gall bladder should be included in the search for the site of metastasis.</p

Associations between Body Mass Index and serum levels of C-Reactive Protein

Background: Obesity imposes increased risks of cardiovascular disease and glucose intolerance, a phenomenon of chronic inflammation. This study was performed to determine whether higher body mass index (BMI) and central obesity are associated with low-grade inflammation. Methods: 8453 adults aged 20 years and older, were analyzed. Every subject completed a household interview, BMI measurement, serum C-reactive protein (CRP) measurement, and a questionnaire regarding personal health. BMI was divided into quintiles, using multiple linear regression to estimate the relationship between CRP level and BMI quintiles. An extended-model approach was used for covariate adjustment. The association of central obesity and CRP level was examined with this method as well. Results: After controlling for demographics, chronic diseases, health behaviors, and levels of folate and vitamin B12, the β coefficient, representing the change of natural-log-transformed levels of CRP for each 1 kg/m2 increased in BMI, was 0.078(

Association between estradiol levels in early pregnancy and risk of preeclampsia after frozen embryo transfer

IntroductionThe failure of remodeling the spiral arteries is associated with the pathogenesis of preeclampsia. Estradiol (E2) plays a crucial role in placentation and may be involved in the development of preeclampsia. However, there is a lack of data in this area. This study aims to assess the association between serum estradiol levels in early pregnancy and the risk of preeclampsia.MethodsWe conducted a retrospective cohort study on patients who conceived after frozen embryo transfer (FET) using data from a database at a university-affiliated in vitro fertilization center. The study period spanned from January 1, 2010, to December 31, 2020. Multivariable logistic regression analyses were performed to determine the adjusted effect of E2 levels on the risk of preeclampsia. We compared the odds ratios of preeclampsia across quartiles of E2 levels and assessed their significance.ResultsSerum E2 levels at the fifth gestational week were significantly different between women with and without preeclampsia after FET programmed cycles (607.5 ± 245.4 vs. 545.6 ± 294.4 pg/ml, p=0.009). A multivariable logistic regression model demonstrated that E2 levels in early pregnancy were independent risk factors for preeclampsia. We observed an increased odds ratio of preeclampsia with increasing quartiles of estradiol levels after adjusting for potential confounders in FET programmed cycles. When comparing quartiles 3 and 4 (E2 &gt; 493 pg/ml at the fifth gestational week) to quartiles 1 and 2, the odds ratios of preeclampsia were significantly higher.ConclusionWe found that serum E2 levels in early pregnancy may impact the risk of preeclampsia, particularly following FET programmed cycles. The association between E2 levels in early pregnancy and preeclampsia deserves further investigation

The clinical application of electrical impedance technology in the detection of malignant neoplasms: a systematic review

Background: Electrical impedance technology has been well established for the last 20 years. Recently research has begun to emerge into its potential uses in the detection and diagnosis of pre-malignant and malignant conditions. The aim of this study was to systematically review the clinical application of electrical impedance technology in the detection of malignant neoplasms. Methods: A search of Embase Classic, Embase and Medline databases was conducted from 1980 to 22/02/2018 to identify studies reporting on the use of bioimpedance technology in the detection of pre-malignant and malignant conditions. The ability to distinguish between tissue types was defined as the primary endpoint, and other points of interest were also reported. Results: 731 articles were identified, of which 51 reported sufficient data for analysis. These studies covered 16 different cancer subtypes in a total of 7035 patients. As the studies took various formats, a qualitative analysis of each cancer subtype’s data was undertaken. All the studies were able to show differences in electrical impedance and/or related metrics between malignant and normal tissue. Conclusions: Electrical impedance technology provides a novel method for the detection of malignant tissue, with large studies of cervical, prostate, skin and breast cancers showing encouraging results. Whilst these studies provide promising insights into the potential of this technology as an adjunct in screening, diagnosis and intra-operative margin assessment, customised development as well as multi-centre clinical trials need to be conducted before it can be reliably employed in the clinical detection of malignant tissue

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Two Strategies to Improve the Differential Evolution Algorithm for Optimizing Design of Truss Structures

The performance of differential evolution (DE) mostly depends on mutation operator. Inappropriate configurations of mutation strategies and control parameters can cause stagnation due to over exploration or premature convergence due to over exploitation. Balancing exploration and exploitation is crucial for an effective DE algorithm. This work presents an enhanced DE (EDE) for truss design that utilizes two new strategies, namely, integrated mutation and adaptive mutation factor strategies, to obtain a good balance between the exploration and exploitation of DE. Three mutation strategies (DE/rand/1, DE/best/2, and DE/rand-to-best/1) are combined in the integrated mutation strategy to increase the diversity of random search and avoid premature convergence to a local minimum. The adaptive mutation factor strategy systematically adapts the mutation factor from a large value to a small value to avoid premature convergence in the early searching period and to increase convergence to the global optimum solution in the later searching period. The outstanding performance of the proposed EDE is demonstrated through optimization of five truss structures

A Comparative Study of the Least Squares Method and the Genetic Algorithm in Deducing Peak Ground Acceleration Attenuation Relationships

In engineering applications, the development of attenuation relationships in a seismic hazard analysis is a useful way to plan for earthquake hazard mitigation. However, finding an optimal solution is difficult using traditional mathematical methods because of the nonlinearity of many relationships. Furthermore, using unweighted regression analysis in which each recording carries an equal weight is often problematic because of the non-uniform distribution of the data with respect to distance