The Effect of Light Therapy on Electroencephalographic Sleep in Sleep and Circadian Rhythm Disorders: A Scoping Review.

Light therapy is used to treat sleep and circadian rhythm disorders, yet there are limited studies on whether light therapy impacts electroencephalographic (EEG) activity during sleep. Therefore, we aimed to provide an overview of research studies that examined the effects of light therapy on sleep macro- and micro-architecture in populations with sleep and circadian rhythm disorders. We searched for randomized controlled trials that used light therapy and included EEG sleep measures using MEDLINE, PubMed, CINAHL, PsycINFO and Cochrane Central Register of Controlled Trials databases. Five articles met the inclusion criteria of patients with either insomnia or delayed sleep−wake phase disorder (DSWPD). These trials reported sleep macro-architecture outcomes using EEG or polysomnography. Three insomnia trials showed no effect of the timing or intensity of light therapy on total sleep time, wake after sleep onset, sleep efficiency and sleep stage duration compared to controls. Only one insomnia trial reported significantly higher sleep efficiency after evening light therapy (>4000 lx between 21:00−23:00 h) compared with afternoon light therapy (>4000 lx between 15:00−17:00 h). In the only DSWPD trial, six multiple sleep latency tests were conducted across the day (09:00 and 19:00 h) and bright light (2500 lx) significantly lengthened sleep latency in the morning (09:00 and 11:00 h) compared to control light (300 lx). None of the five trials reported any sleep micro-architecture measures. Overall, there was limited research about the effect of light therapy on EEG sleep measures, and studies were confined to patients with insomnia and DSWPD only. More research is needed to better understand whether lighting interventions in clinical populations affect sleep macro- and micro-architecture and objective sleep timing and quality.

High-throughput assay of tyrosine phenol-lyase activity using a cascade of enzymatic reactions.

Tyrosine phenol-lyase (TPL) exhibits great potential in industrial biosynthesis of l-tyrosine and its derivates. To uncover and screen TPLs with excellent catalytic properties, there is unmet demand for development of facile and reliable screening system for TPL. Here we presented a novel assay format for the detection of TPL activity based on catechol 2,3-dioxygenase (C23O)-catalyzed reaction. Catechol released from TPL-catalyzed cleavage of 3,4-dihydroxy-l-phenylalanine (l-DOPA) was further oxidized by C23O to form 2-hydroxymuconate semialdehyde, which could be readily detected by spectrophotometric measurements at 375 nm. The assay achieved a unique balance between the ease of operation and superiority of analytical performances including linearity, sensitivity and accuracy. In addition, this assay enabled real-time monitoring of TPL activity with high efficiency and reliability. As C23O is highly specific towards catechol, a non-natural product of microorganism, the assay was therefore accessible to both crude cell extracts and the whole-cell system without elaborate purification steps of enzymes, which could greatly expedite discovery and engineering of TPLs. This study provided fundamental principle for high-throughput screening of other enzymes consuming or producing catechol derivatives.

The relationships between screen time and mental health problems among Chinese adults.

BACKGROUND: This study aimed to examine the specific relationships between screen time and various mental health problems among community-dwelling adults in China. METHODS: Self-reports of weekday and weekend screen time (TV, computer use and cell phone/tablet use), symptoms of PTSD, depression, and ADHD, and psychotic-like experiences (PLEs) were completed by 7121 Chinese adults. Logistic regression was used to examine specific relationships between screen time and mental health problems with demographics, physical activity, drinking, smoking, and sleep duration as covariates. RESULTS: On weekdays, the participants spending at least 3 h on watching TV, computer use and cell phone/tablet use respectively accounted for 6.8%, 15.9% and 45.9%. On weekends, the proportions were 15.5%, 12.1% and 50.0%. Computer use on weekends was associated with higher risk of PTSD (OR = 1.81); cell phone/tablet use on weekdays and weekends was related to increased depression (OR = 1.38, OR = 1.28, respectively), while only computer use on weekends was related to depression (OR = 1.33); cell phone/tablet use both on weekdays and weekends was also connected to ADHD (OR = 1.56, OR = 1.48, respectively); on weekdays and weekends, more time TV viewing (OR = 1.76-1.79, OR = 1.46-1.71, respectively) and less cell phone/tablet use (OR = 0.66, OR = 0.65, respectively) were associated with higher numbers of PLEs. CONCLUSIONS: The relationships between different types of screen time and mental health problems are variant. Future longitudinal studies should subdivide screen time on the basis of content and explore the specific causal relationship between screen time and mental health problems.

Efficient strategies to enhance plasmid stability for fermentation of recombinant Escherichia coli harboring tyrosine phenol lyase.

OBJECTIVE: To solve the bottleneck of plasmid instability during microbial fermentation of L-DOPA with recombinant Escherichia coli expressing heterologous tyrosine phenol lyase. RESULTS: The tyrosine phenol lyase from Fusobacterium nucleatum was constitutively expressed in E. coli and a fed-batch fermentation process with temperature down-shift cultivation was performed. Efficient strategies including replacing the original ampicillin resistance gene, as well as inserting cer site that is active for resolving plasmid multimers were applied. As a result, the plasmid stability was increased. The co-use of cer site on plasmid and kanamycin in culture medium resulted in proportion of plasmid containing cells maintained at 100% after fermentation for 35 h. The specific activity of tyrosine phenol lyase reached 1493 U/g dcw, while the volumetric activity increased from 2943 to 14,408 U/L for L-DOPA biosynthesis. CONCLUSIONS: The established strategies for plasmid stability is not only promoted the applicability of the recombinant cells for L-DOPA production, but also provides important guidance for industrial fermentation with improved microbial productivity.

Development and evaluation of colour control interfaces for LED lighting.

To capitalise on the colour tuning capabilities of LED lighting, a model for converting device-specific control signals to chromaticity coordinates was used in a psychophysical experiment evaluating the usability of three colour control interfaces based on RGB (red, green, blue), HSB (hue, saturation, brightness) and opponent colour mixing systems. Although common and well accepted, the RGB interface had lowest usability based on both psychophysical results and subjective ratings. The usability of HSB and opponent colour interfaces was not significantly different. These findings can guide the development of useful and efficient colour control interfaces for tunable LED lighting systems.

Dimming curve based on the detectability and acceptability of illuminance differences.

In a psychophysical forced-choice experiment, observers' ability to detect illuminance differences was found to be 7.4% of the initial illuminance. When matching the illuminance of one space with another, observers' acceptance of illuminance differences was 17.8% to 19.1%. Lighting control systems with resolutions between 14.8% and 17.7% were found to have greater usability than others. A new approach to step-dimming leverages knowledge of the detectability and acceptability of illuminance differences, as well as usability, to reduce lighting energy consumption. This method can reduce lighting energy consumption more than continuous dimming.