ERP detection based on smoothness priors

Objective: Detection of event-related potentials (ERPs) in electroencephalography (EEG) is of great interest in the study of brain responses to various stimuli. This is challenging due to the low signal-to-noise ratio of these deflections. To address this problem, a new scheme to detect the ERPs based on smoothness priors is proposed. Methods: The problem is considered as a binary hypothesis test and solved using a smooth version of the generalized likelihood ratio test (SGLRT). First, we estimate the parameters of probability density functions from the training data under the Gaussian assumption. Then, these parameters are treated as known values and the unknown ERPs are estimated under the smoothness constraint. The performance of the proposed SGLRT is assessed for ERP detection in post-stimuli EEG recordings of two oddball settings. We compared our method with several powerful methods regarding ERP detection. Results: The presented method performs better than the competing algorithms and improves the classification accuracy. Conclusion: SGLRT can be employed as a powerful means for different ERP detection schemes. Significance: The proposed scheme is opening a new direction in ERP identification which provides better classification results compared to several popular ERP detection methods

Frequency of Candiduria in patients Hospitalized in Intensive Care Units

Abstract: Background & Aims: Some Candida species especially Candida albicans are known as flora of human and animals body and coexist in skin, throat and gastrointestinal and urinary tracts. They can primarily be colonized in hospitalized patients and cause diseases. Resent studies have reported increasing rate of candidauria in intensive care unit (ICU) patients. The aim of this study was to determine the frequency of candiduria in ICU patients with urinary tract catheterization. Method: In a descriptive cross- sectional study, 110 hospitalized patients in ICU over 18 years old who had more than 7 days urinary tract catheter were studied. Urine sample was taken immediately after catheter replacement and sent to the laboratory in less than 1 hour and analyzed. Data collection was done by a questionnaire and check list. Results: A total of 110 patients including 65 men (59.1%) and 45women (40.9%) were studied of whom 29 ones (26.4%) had candiduria based on urine culture. Candida albicans was the most common species (34.3%). Risk factors of candiduria were age, duration of hospitalization and urinary tract catheterization, using more than two antibiotics, corticosteroid consumption, and diabetes mellitus. Conclusion: Due to the increasing rate of candida infection in hospitalized patients especially ICU patients, more attention for prevention of candiduria especially in those with candiduria risk factors is recommended. Keywords: Candidiasis, Urinary tract infection, Urinary catheterization, Intensive care uni

Improving the performance of P300-based BCIs by mitigating the effects of stimuli-related evoked potentials through regularized spatial filtering

Objective: the P300-based brain-computer interface (BCI) establishes a communication channel between the mind and a computer by translating brain signals into commands. These systems typically employ a visual oddball paradigm, where different objects (linked to specific commands) are randomly and frequently intensified. Upon observing the target object, users experience an elicitation of a P300 event-related potential in their electroencephalography (EEG). However, detecting the P300 signal can be challenging due to its very low signal-to-noise ratio (SNR), often compromised by the sequence of visual evoked potentials (VEPs) generated in the occipital regions of the brain in response to periodic visual stimuli. While various approaches have been explored to enhance the SNR of P300 signals, the impact of VEPs has been largely overlooked. The main objective of this study is to investigate how VEPs impact P300-based BCIs. Subsequently, the study aims to propose a method for EEG spatial filtering to alleviate the effect of VEPs and enhance the overall performance of these BCIs. Approach: Our approach entails analyzing recorded EEG signals from visual P300-based BCIs through temporal, spectral, and spatial analysis techniques to identify the impact of VEPs. Subsequently, we introduce a regularized version of the xDAWN algorithm, a well-established spatial filter known for enhancing single-trial P300s. This aims to simultaneously enhance P300 signals and suppress VEPs, contributing to an improved overall signal quality. Main results: analyzing EEG signals shows that VEPs can significantly contaminate P300 signals, resulting in a decrease in the overall performance of P300-based BCIs. However, our proposed method for simultaneous enhancement of P300 and suppression of VEPs demonstrates improved performance in P300-based BCIs. This improvement is verified through several experiments conducted with real P300 data. Significance: this study focuses on the effects of VEPs on the performance of P300-based BCIs, a problem that has not been adequately addressed in previous studies. It opens up a new path for investigating these BCIs. Moreover, the proposed spatial filtering technique has the potential to further enhance the performance of these systems

Comparison of Helicobacter pylori seroprevalance between acne rosacea and healthy group

Background and Objective: Acne rosacea is a chronic skin disease with unknown etiology. Some reports have suggested an increased prevalence of helicobacter (H) pylori infection in patients with acne rosacea but it is controversial. This study was designed to compare the prevalence of H pylori between the acne rosacea patients and the healthy control group. Materials and Methods: This case-control study was performed on 30 patients with acne rosacea and 60 healthy individuals as a control group. 5 mL blood was taken from each person and anti-H pylori IgG was measured by enzyme-linked immunosorbent assay. Results: Mean age was 45.8±14.05 years in acne rosacea patients and 41.4±12.3 years in control group. Seventeen (56.7) of patients and fifty two (86.2) of controls were infected by H pylori (P=0.002), but mean serum anti-H pylori IgG level was significantly higher in acne rosacea patients comparing to healthy control group (139.49±174.15 g/mL vs 38.87±23.50, P=0.005). Conclusion: Despite increased mean serum anti-H pylori IgG levels in acne rosacea patients, H pylori was more prevalent in healthy control group, in this study

Peripheral Blood Mononuclear Cell Mycobacterium tuberculosis PCR sensitivity in diagnosis of Tuberculosis

Background: Tuberculosis is still one of the most important causes of mortality and morbidity in many countries and is the second only to human immunodeficiency virus as a cause of death worldwide resulting from a single infectious agent. In 1993, the World Health Organization declared tuberculosis a global public health emergency. Conven-tional methods for the diagnosis of Mycobacterium tuberculosis (MTB) infections are time consuming, as MTB culture requires 3-8 weeks for growth. To determine the sensitivity of polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC), we have evaluated Mycobacterium tuberculosis DNA in peripheral blood samples with PCR technique in adults with new cases of pulmonary and extra-pulmonary tuberculosis. Setting: Department of Infectious disease of Imam Khomeini Hospital, 2004- 2005, Tehran, Iran.Methods: In this cross-sectional study, we evaluated MTB DNA extracted from 3ml citrated peripheral blood samples from 95 adults with new cases of pulmonary and extra-pulmonary tuberculosis. DNA extraction was performed using a commercial PCR kit with IS1081 primers. For prevention of cross contamination and reduction of false positives, all steps were performed under laminar hood.Results: The 95 patients, 59 of whom were male, had a mean age 44.44 years (SD±20.26); 69 cases had pulmonary and 26 had extra-pulmonary tuberculosis. PCR was positive in 32 (33.7%) patients and negative in 63 (66.3%) cases. The overall sensitivity and accuracy of the PCR assay was 44.1% for pulmonary, 19.2% for extra-pulmonary and 10% for disseminated tuberculosis, respectively.Conclusion: The low sensitivity of the IS1081 primer MTB-PCR assay on PBMC may pose problems for the rapid diagnosis of tuberculosis. However, further studies are needed to confirm this technique as an alternative test for the diagnosis of tuberculosis

Epidemiology of hepatitis B in pregnant Iranian women: a systematic review and meta-analysis

Perinatal transmission is one of the most common routes of hepatitis B virus (HBV) transmission. This study aims to identify the epidemiological features of HBV among pregnant Iranian women. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Two authors independently searched several online databases without time limit until May 2017. The databases include Magiran, Iranmedex, SID, Medlib, IranDoc, Scopus, PubMed, Science Direct, Cochrane, Web of Science and Google Scholar. The data were analyzed based on a random-effects model using Comprehensive Meta-Analysis software version 2. Thirty-seven studies were included in the meta-analysis. The prevalence of HBV among pregnant Iranian women was 1.18 (95 CI: 0.09-1.53). The prevalence of HBV among pregnant women living in urban and rural areas was 1.60 (95 CI: 0.06-4.30) and 1.70 (95 CI: 0.09-3.2), respectively. The prevalence of HBV among housewives and working pregnant women was 4.3 (95 CI: 1.4-12.5) and 1.2 (95 CI: 0.02-5.8), respectively. The risk of developing an HBV infection was significantly associated with illiteracy (p = 0.013), abortion (p = 0.001), blood transfusion (p < 0.001) and addicted spouse (p = 0.045). However, no significant relationship was observed between HBV infection and urbanization (p = 0.65), occupation (p = 0.37), history of surgery (p = 0.32) or tattooing (p = 0.69). Vaccination coverage (receiving at least a single dose) in pregnant women was 9.8 (95 CI: 5.3-17.5). The prevalence of HBV among pregnant women is lower than in the general population of Iran. HBV vaccination coverage was low among pregnant Iranian women. Therefore, health policy-makers are recommended to enforce immunization programs for HBV vaccination among high-risk pregnant women