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Online reviews have increasingly become a very important resource before making a purchasing decisions. Unfortunately, malicious sellers try to game the system by hiring a person or team (which is called spammers) to fabricate fake reviews to improve their reputation. Existing methods mainly take the problem as a general binary classification or focus on some heuristic rules. However, supervised learning methods relies heavily on a large number of labeled examples of deceptive and truthful opinions by domain experts, and most of features mentioned in the heuristic strategy ignore the characteristic of the group organization among spammers. In this paper, an effective method of identifying opinion spammers is proposed. Firstly, suspected spammers are detected by means of unsupervised learning based on reviewer's reputation. We believe that the reviewer's reputation has a direct relation with the quality of reviews. Generally, review written by user with lower reputation, shows lower quality and higher possibility to be fake. Therefore, the model assigns reputation score to each reviewer wherein the content based factors and activeness of reviewers are employed efficiently. On basis of all suspected spammers, k-center clustering algorithm is performed to further spot the spammers based on the observation of burst of review release time. Experimental results on Amazon's dataset are encouraging and indicate that our approach poses high accuracy and recall, and good performance is achieved. Keywords: opinion spammer, fake review, reviewer reputation, clustering analysis. [ABSTRACT FROM AUTHOR]

Introduction. With the introduction of iodized salt, more and more people are exposed to iodine sufficiency in some regions. The purpose of this study was to investigate the prevalence of nontoxic nodular goiter (NTNG) in the littoral region with high iodine supply after a nearly twodecade universal salt iodization. Subjects and Methods. Eight hundred and thirtyfive participants (from 25~65 years; males 421 and females 414) were invited for the study from Huan-cui District of Weihai City, Shandong Province from January 2013 to September 2014. All participants were inspected and diagnosed by endocrinologists according to the thyroid function tests and the thyroid gland imaging. After the normal diet of three days, the urine samples of the participants were collected between 8:00AM and 9:00AM and the urinary iodine (UI) concentrations were analyzed using Urinary Iodide Test Kit. Results. The overall prevalence of NTNG in the region was 40.1%, and different prevalence occurred in the different age ranges (p<0.01). The prevalence of NTNG was 32.51%, 37.44%, 49.70%, 58.57 and 74.77% in the age group of ≤ 30, 31-40, 41-50, 51-60 and >60 years, respectively. Meanwhile, the prevalence of NTNG in women (42.08%) was higher than that in men (34.29%, p<0.05). The median of UI concentrations were 139.4µg/L and 101.5µg/L for the group with NTNG and without NTNG, respectively (p<0.01). However, there was no significant difference in UI concentrations among the groups with different age ranges (p>0.05), and statistical difference was not observed for UI concentrations between women and men (p>0.05). Intriguingly, higher UI concentrations were found in the group with larger thyroid size (p<0.01). Conclusion. The iodine excess can lead to the high occurrence of nodular goiter in the littoral region, and individual UI concentration detection is recommended for the iodine nutritional status analysis among normal people when Universal Salt Iodization (USI) continues to be implemented in the region. [ABSTRACT FROM AUTHOR]

This study determined the level of PITX2 methylation in prostate cancer and benign tissues and its relationship with the postoperative survival rate. Forty-four patients with prostate cancer who underwent radical prostatectomy and 43 patients with benign prostatic hyperplasia were selected. DNA was extracted from the tissues and PITX2 methylation status was quantitatively analyzed by using the EpiTect MethyLight method. The median follow-up time of the patients was 63 months and was used to analyze the relationship between PITX2 methylation status with tumor stage and survival rates. Median PITX2 gene expression in benign tissues was 1.46, which was higher than that of tumor tissues with a median of 0.01 (P < 0.001). The median methylation in the controls was less than 0.001%, while the median methylation in the test group was 23.3% (P = 0.000). The number of patients with low methylation level in T2 stage was 15, which was more than that in T3 and T4 stages (8 patients); while the number of patients with high methylation levels in T2 stage was 6, which was less than that in T3 and T4 stages (15 patients) (P = 0.035). The PITX2 gene expression level in prostate cancer tissues was lower than that in benign tissues. A higher degree of PITX2 DNA methylation was associated with higher tumor stage and lower survival rates. PITX2 DNA methylation presents a good predictive value for prostate cancer survival.

With the advancement of ultrasonic technology in recent years, sonography has become a common medical diagnostic tool, as it has elevated output sonic intensity and elongated exposure time. This study investigates the effect of ultrasound on human chorionic villus cell apoptosis during early pregnancy. Transvaginal ultrasound was performed for a total of 60 women who had undergone induced abortion at our hospital. They were randomly divided into the control, short ultrasound (10 min), and long ultrasound (20 min) groups (N = 20 each). Twenty-four hours after ultrasonic exposure, chorionic villus tissues were extracted during induced abortion, and were tested for cell apoptosis using flow cytometry. Bax and B cell lymphoma-2 (Bcl-2) protein levels were also quantified by immunohistochemistry. We found that the long ultrasound group had significantly higher cell apoptosis rates compared to the short ultrasound group, which in turn had higher rates compared to the control group (P < 0.05 in both cases). Bax protein levels were elevated in both the long and short ultrasound groups (P < 0.05). Bcl-2 proteins in two ultrasound groups, however, were downregulated as compared to those in the control group (P < 0.05). It is therefore possible that transvaginal sonography can potentiate the apoptosis of human chorionic villus cells by increasing the Bax/Bcl-2 protein ratio.