All photobiological events depend on the wavelength of the incident radiation. In real-life situations and in the vast majority of laboratory experiments, exposure always involves sources with various emission spectra spreading over a wide wavelength range. Action spectra are often used to describe the efficiency of a process at different wavelengths and to predict the effects of a given light source by summation of the individual effects at each wavelength. However, a full understanding of the biological effects of complex sources requires more than considering these concomitant events at each specific wavelength. Indeed, photons of different energies may not have additive but synergistic or inhibitory effects on photochemical processes and cellular responses. The evolution of a photobiological response with post-irradiation time must also be considered. These two aspects may represent some limitations to the use of action spectra. The present review, focused on mammalian cells, illustrates the concept of action spectrum and discusses its drawbacks using theoretical considerations and examples taken from the literature. Emphasis is placed on genotoxicity for which wavelength effects have been extensively studied. Other effects of UV exposure are also mentioned.Near-infrared (NIR) probes are applicable for tumor imaging due to deep tissue penetration and low background signal. And cyanine dyes with long emission wavelength are excellent fluorophores to develop NIR probes. However, the aggregation of cyanine dyes in aqueous solution reduces the utilization of light. To solve this problem, polyethylene glycol (PEG) was introduced into the probes to reduce their aggregation. In our work, two new NIR probes G1 and G2 were designed and prepared by conjugating the cyanine dye G0 with Biotin-PEG5-Azide. The conjugated biotin could enhance the target specificity of probes. And the photophysical and photochemical parameters demonstrated that G1 and G2 had a reduced aggregation tendency. In vitro fluorescence imaging proved that these two probes could be specifically taken up by HeLa cells, and in vivo imaging demonstrated that these two probes could specifically target tumors with large tumor-to-muscle (T/M) ratios. All these results indicated that G1 and G2 are promising NIR fluorescent contrast agents for tumor-specific imaging.Ultraviolet (UV) disinfection efficiency by low-pressure (LP) mercury lamp depends on the UV fluence (dose) the product of incident irradiance (fluence rate) and exposure time, with correction factors. Time-dose reciprocity may not always apply, as higher UV-LP inactivation of E. coli was obtained at a higher irradiance over shorter exposure time, for the same UV fluence. Disinfection by UV LEDs is limited by low radiant flux compared to mercury LP lamps. Our goal was to determine the UV-LED time-dose reciprocity of E. coli for four different central LED wavelengths (265, 275, 285 and 295 nm) under different fluence rates. Inactivation kinetics determined at UV-LED265 was not affected by the fluence rate or exposure time for a given UV fluence. In contrast, UV-LED275, UV-LED285, and UV-LED295 led to higher inactivation at low fluence rate coupled to high exposure time, for the same UV fluence. The intracellular damage mechanisms for each LED central wavelength were determined by using the bioreporters RecA as an indicator of bacterial DNA damage and SoxS as an indicator of oxidative stress. For 265 nm, higher DNA damage was observed, whereas for 285 and 295 nm, higher oxidative stress (possibly due to reactive oxygen species [ROS] damage) was observed.  https://www.selleckchem.com/products/VX-770.html  ROS inactivation of E. coli was predicted to be more effective when keeping the ROS concentration low but allowing longer exposure, for a given UV fluence.Reminiscent to the microbiota-gut-brain axis described in animals, recent advances indicate that plants can take advantage of belowground microbial commensals to orchestrate aboveground stress responses. Integration of plant responses to microbial cues belowground and environmental cues aboveground emerges as a mechanism that promotes stress tolerance in plants. Using recent examples obtained from reductionist and community-level approaches, we discuss the extent to which perception of aboveground biotic and abiotic stresses can cascade along the shoot-root axis to sculpt root microbiota assembly and modulate the growth of root commensals that bolster aboveground stress tolerance. We propose that host modulation of microbiota-root-shoot circuits contributes to phenotypic plasticity and decision-making in plants, thereby promoting adaptation to rapidly changing environmental conditions.
  Spontaneous intracerebral haemorrhage (ICH) is associated with high mortality and high morbidity, including seizures. Seizure prophylaxis is "not recommended" by the American Stroke Association, but practice variation still exists due to inconclusive data. We performed a meta-analysis to assess the current relevant literature to determine the efficacy of seizure prophylaxis following ICH.
 
  We performed searches of PubMed, Scopus, and Embase up to September 15, 2020. We included observational and randomized controlled studies reporting seizure prophylaxis and occurrence in adults with ICH. Outcomes were seizures, as defined by the authors, within 14 days of ICH and at the longest point of follow-up. We used random-effects models to estimate the odds ratios (ORs) for seizure prophylaxis and outcomes. The PROSPERO registration was CRD42019140493.
 
  We included 8 studies (2852 patients) in our analysis. The mean (± standard deviation) age of the pooled patients was 65 (±4) years; 39 % (± 5%) were female. Seizure prophylaxis did not prevent seizures at the longest follow-up time (OR 0.708, 95 % CI 0.438-1.143, p = 0.158, I2 = 34 %). This result was confirmed in subgroup analyses using categorical variables and in meta-regressions using continuous variables. Additionally, seizure prophylaxis was not associated with preventing early seizures, defined as < 14 days of ICH (OR 0.66, 95 % CI 0.21-2.08, p = 0.48, I2 = 35 %).
 
  Seizure prophylaxis following ICH was not associated with seizure prevention in adults. Most included studies were observational. Further randomized controlled trials examining the efficacy of seizure prophylaxis in high-risk patients and different types of antiepileptic drugs are needed.
 Seizure prophylaxis following ICH was not associated with seizure prevention in adults. Most included studies were observational. Further randomized controlled trials examining the efficacy of seizure prophylaxis in high-risk patients and different types of antiepileptic drugs are needed.