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This article reviews exposure information available for trichloroethylene (TCE) and assesses the magnitude of human exposure. The primary sources releasing TCE into the environment are metal cleaning and degreasing operations. Releases occur into all media but mostly into the air due to its volatility. It is also moderately soluble in water and can leach from soils into groundwater. TCE has commonly been found in ambient air, surface water, and groundwaters. The 1998 air levels in pg/M3 across 115 monitors can be summarized as follows: range = 0.01-3.9, mean = 0.88. A California survey of large water utilities in 1984 found a median concentration of 3.0 pg/L. General population exposure to TCE occurs primarily by inhalation and water ingestion. Typical average daily intakes have been estimated as 11-33 pg/day for inhalation and 2-20 pg/day for ingestion. A small portion of the population is expected to have elevated exposures as a result of one or more of these pathways: inhalation exposures to workers involved in degreasing operations, ingestion and inhalation exposures occurring in homes with private wells located near disposal/contamination sites, and inhalation exposures to consumers using TCE products in areas of poor ventilation. More current and more extensive data on TCE levels in indoor air, water, and soil are needed to better characterize the distribution of background exposures in the general population and elevated exposures in special subpopulations.

IONSince late 1999, DDoS (Distributed Denial of Service) [1,2,3] attack has drawn many attentions from both research and industry communities. Many potential solutions (e.g., ingress filtering [6,7], packet marking [5,8,9,10,11] or tracing [4], and aggregate-based congestion control or rate limiting) have been proposed to handle this network bandwidth consumption attack. Among them, "ICMP traceback (iTrace)" is currently being considered as an industry standard by IETF (Internet Engineering Task Force). While the idea of iTrace is very clever, efficient, reasonably secure and practical, it suffers a serious statistic problem such that the chance for "useful" and "valuable" iTrace messages can be extremely small against various types of DDoS attacks. This implies that most of the network resources spent on generating and utilizing iTrace messages will be wasted. Therefore, we propose a simple enhancement called "Intention-Driven" iTrace, which conceptually introduces an extra bit in the routing and forwarding process. With the new "intention-bit", it is shown that, through our simulation study, the performance of iTrace improves dramatically. This work has been proposed to IETF's ICMP Trace-Back working group.

Background and Aims: The impact of statin on dementia risk reduction has been a subject of debate over the last decade, but the evidence remains inconclusive. Therefore, we performed a meta-analysis of relevant observational studies to quantify the magnitude of the association between statin therapy and the risk of dementia. Methods: We systematically searched for relevant studies published from January 2000 to March 2018 using EMBASE, Google, Google Scholar, PubMed, Scopus, and Web of Science. Two authors performed study selection, data abstraction, and risk of bias assessment. We then extracted data from the selected studies and performed meta-analysis of observational studies using a random-effects model. Subgroup and sensitivity analyses were also conducted. Results: A total of 30 observational studies, including 9,162,509 participants (84,101 dementia patients), met the eligibility criteria. Patients with statin had a lower all-caused dementia risk than those without statin (risk ratio [RR] 0.83, 95% CI 0.79-0.87, I 2 = 57.73%). The over-all pooled reduction of Alzheimer disease in patients with statin use was RR 0.69 (95% CI 0.60-0.80, p < 0.0001), and the overall pooled RR of statin use and vascular dementia risk was RR 0.93 (95% CI 0.74-1.16, p = 0.54). Conclusion: This study suggests that the use of statin is significantly associated with a decreased risk of dementia. Future studies measuring such outcomes would provide useful information to patients, clinicians, and policymakers. Until further evidence is established, clinicians need to make sure that statin use should remain restricted to the treatment of cardiovascular disease.

Antidepressants are the most commonly and widely used medication for its effectiveness in the treatment of anxiety and depression. A few epidemiological studies have documented that antidepressant is associated with increased risk of dementia so far. Here, our aim is to assess the association between antidepressant use and risk of dementia in elderly patients. We searched articles through MEDLINE, EMBASE, Google, and Google Scholar from inception to December 1, 2017, that reported on the association between antidepressant use and dementia risk. Data were collected from each study independently, and study duplication was checked by at least three senior researchers based on a standardized protocol. Summary relative risk (RR) with 95% CI was calculated by using a random-effects model. We selected 9 out of 754 unique abstracts for full-text review using our predetermined selection criteria, and 5 out of these 9 studies, comprising 53,955 participants, met all of our inclusion criteria. The overall pooled RR of dementia was 1.75 (95% CI: 1.033–2.964) for SSRIs whereas the overall pooled RR of dementia was 2.131 (95% CI: 1.427–3.184) for tricyclic use. Also, MAOIs showed a high rate of increase with significant heterogeneity. Our findings indicate that antidepressant use is significantly associated with an increased risk of developing dementia. Therefore, we suggest physicians to carefully prescribe antidepressants, especially in elder patients. Additionally, treatment should be stopped if any symptoms related to dementia are to be noticed.

Background: A potential evidence from previous epidemiological studies remains conflicting findings regarding the association between atrial fibrillation (AF) and dementia risk. We, therefore, carried out a meta-analysis of relevant studies to investigate the magnitude of the association between AF and dementia risk.Methods: We performed a systematic literature search of PubMed, EMBASE, and Google Scholar for potential studies between January 1, 1990, and December 31, 2018, with no restriction on the publication language. All potential studies were independently assessed by two reviewers. We only included observational studies that calculated the odds ratio (OR)/hazards ratio (HR) for dementia associated with atrial fibrillation. We first assessed the heterogeneity among study-specific HRs using the Q statistic and I2 statistic. We then used the random-effects model to obtain the overall HR and its 95% CI for all studies. We also tested and corrected for publication bias by funnel plot–based methods. The quality of each study was assessed with the Newcastle Ottawa Scale.Results: A total of 16 studies with 2,415,356 individuals, and approximately 200,653 cases of incidence dementia were included in this study. Patients with AF had a greater risk of incidence dementia than those without AF (random-effect hazard ratio HR: 1.36, 95% CI: 1.23–1.51, p < 0.0001; I2 = 83.58). Funnel plot and Egger test did not reveal significant publication bias. However, limitations of the study included high heterogeneity and varying degrees of confounder adjustment across individual studies.Conclusion: This study serves as added evidence supporting the hypothesis that AF is associated with an increased risk of dementia. More studies are needed to establish whether optimal treatment of AF can reduce or mitigate the risk of dementia.

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