A review of methods for assessment of cognitive function in high-altitude hypoxic environments.

Hypoxic environments like those present at high altitudes may negatively affect brain function. Varying levels of hypoxia, whether acute or chronic, are previously shown to impair cognitive function in humans. Assessment and prevention of such cognitive impairment require detection of cognitive changes and impairment using specific cognitive function assessment tools. This paper summarizes the findings of previous research, outlines the methods for cognitive function assessment used at a high altitude, elaborates the need to develop standardized and systematic cognitive function assessment tools for high-altitude hypoxia environments.

Assessment of seawater bacterial infection in rabbit tibia by Illumina MiSeq sequencing and bacterial culture.

OBJECTIVES: We aimed to explore the bacterial community composition following ocean bacterial infection using an animal model. METHODS: This animal-based experiment was conducted from September 2019 to November 2019. Eighteen seawater filter membranes were collected from Changle City, Fujiian Province, China, on September 8, 2019. Ten filter membranes were used for implantation. Eight filter membranes that were used in the bacterial culture for the exploration of seawater bacteria were assigned to the seawater group (SG). Fourteen healthy adult New Zealand rabbits were randomly divided into the experimental group (EG) and control group (CG). Seawater filter membranes and asepsis membranes were implanted into the tibia in the EG and CG, respectively. One week after surgery, tibial bone pathology tissues were collected and assessed using light microscopy and scanning electron microscopy (SEM). Medullary cavity tissues were collected for the performance of Illumina MiSeq sequencing and bacterial culture. The differences between EG and CG were assessed by pathological observation under light microscopy and SEM, high-throughput bacterial sequencing, and bacterial culture. RESULTS: Compared with the CG, the infection rate was 100%, and the mortality value was 20% after the implantation of the filter membranes in the EG. Both light microscopy and SEM showed that a large number of bacteria were distributed in the bone marrow cavity after ocean bacterial infection. No bacterial growth was found in the CG. Illumina MiSeq sequencing found that Firmicutes, Proteobacteria, Thermotogae, Fusobacteria, Bacteroidetes, and Actinobacteria were the dominant bacteria at the phylum level and Clostridium_sensu_stricto_7, Haloimpatiens, Clostridium_sensu_stricto_15, Clostridiaceae_1, Clostridium_sensu_stricto_18, and Oceanotoga were the dominant bacteria in genus level among the EG. In the bacterial culture of the medullary cavity tissues, Klebsiella pneumoniae, Shewanella algae, Staphylococcus aureus, Escherichia coli, Enterobacter cloacae, and Vibrio vulnificus were the predominant infective species. Moreover, compared with the SG, the EG showed a higher detection rate of E. coli and S. aureus (P = 0.008 and P = 0.001, respectively). The detection rates of V. alginolyticus, V. parahaemolyticus, and V. fluvialis were higher in the SG than the EG (P = 0.007, P = 0.03, and P = 0.03, respectively). CONCLUSIONS: Our model, which was comprehensively evaluated using four techniques: histopathology and SEM observation, gene detection, and bacteria culture, provides a scientific basis for the clinical diagnosis and treatment of patients in such settings.

Rapid and sensitive double-label based immunochromatographic assay for zearalenone detection in cereals.

A double-label immunochromatographic based assay (DL-ICA) was developed to monitor zearalenone (ZEN) levels in cereals, based on Eu3+ nanoparticles (EuNP). The DL-ICA exhibited excellent sensitivity, reliability and selectivity in real samples. It showed low limits of detection (0.21-0.25 µg/kg) and broad analytical ranges (up to 120 µg/kg). The total analytical time, including sample preparation and DL-ICA execution, was reduced by 15 min compared with HPLC. The recovery rates ranged from 95.0-118.4%, with relative standard deviations (RSD) <11.6%. Inter- and intra-day validations were assessed, recovery rates of 89.3-106.9% and RSD of 2.3-9.7% were obtained, suggesting considerable stability and reliability for the assay. An excellent correlation was observed between DL-ICA and a reference HPLC method (R2 = 0.9899). Compared to current immunoassays, the current DL-ICA is inexpensive, highly sensitive, and rapid. Therefore, DL-ICA constitutes a novel tool for monitoring mycotoxins in food and feed to ensure safety.

Abnormal baseline brain activity in patients with pulsatile tinnitus: a resting-state FMRI study.

Numerous investigations studying the brain functional activity of the tinnitus patients have indicated that neurological changes are important findings of this kind of disease. However, the pulsatile tinnitus (PT) patients were excluded in previous studies because of the totally different mechanisms of the two subtype tinnitus. The aim of this study is to investigate whether altered baseline brain activity presents in patients with PT using resting-state functional magnetic resonance imaging (rs-fMRI) technique. The present study used unilateral PT patients (n = 42) and age-, sex-, and education-matched normal control subjects (n = 42) to investigate the changes in structural and amplitude of low-frequency (ALFF) of the brain. Also, we analyzed the relationships between these changes with clinical data of the PT patients. Compared with normal controls, PT patients did not show any structural changes. PT patients showed significant increased ALFF in the bilateral precuneus, and bilateral inferior frontal gyrus (IFG) and decreased ALFF in multiple occipital areas. Moreover, the increased THI score and PT duration was correlated with increased ALFF in precuneus and bilateral IFG. The abnormalities of spontaneous brain activity reflected by ALFF measurements in the absence of structural changes may provide insights into the neural reorganization in PT patients.

[Relationship between surface electromyographic signal (sEMG) changes and subjective assessment of muscle fatigue during isometric contractions].

OBJECTIVE: To investigate the numerical relationship between the changes of surface electromyographic (sEMG) signal indexes and subjective assessment of muscle fatigue during isometric contractions. METHOD: Eleven healthy subjects participated in the experiment. The sEMG signals of biceps were recorded during their sustained isometric contractions at 50% maximum voluntary contraction (MVC). Fatigue was subjectively rated using a Borg CR-10 scale. Correlations between Borg ratings and a series of fatigue-related indexes such as MPF, MF and Lempel-ziv complexity were analyzed, and curve estimation was also explored. RESULT: A strong positive correlation was found between Borg ratings and endurance time, and negative correlations at different degrees were found between Borg ratings and each of sEMG signal indexes. Curve estimation (Logarithmic curve and Power curve) was also significant. CONCLUSION: The significant correlation between the Borg scale, sEMG signal indexes and endurance time indicates a close relationship between subjective and objective assessment of muscle fatigue. The numerical relationship between them accord with the power law of Stevens in psychophysics relatively.