BACKGROUND: In response to growing concerns about the health effects of quasi-millimeter waves (qMMW) used in 5th-generation wireless systems, conservative whole-body exposure thresholds based on indirect evidence have been proposed. The guidelines define a whole-body average specific absorption rate (WBA-SAR) of 4 W/kg which causes a 1 °C increase in core temperature, as the operational threshold for adverse health effects. To address the lack of direct evidence, we recently reported that a 30-minute exposure to qMMW at 4.6 W/kg resulted in a 1 °C increase in rat core temperature. Here, we further analyzed the near-threshold stress response for the first time, using biological samples from the aforementioned and additional experiments. METHODS: A total of 59 young Sprague-Dawley rats (240-322 g) were exposed to 28 GHz for 40 minutes at WBA-SARs of 0, 3.7, and 7.2 W/kg, under normal (22.5 °C, 45-55% humidity), and heat (32 °C, 70% humidity) conditions. Rats were restrained in acrylic holders for dose control. We repeatedly measured serum and urinary biomarkers of stress response, aggregated the data, and analyzed them using a single statistical mixed model to subtract the effects of sham exposure and between-subject variation. RESULTS: Sham exposure induced stress responses, suggesting an effect of restraint. After the subtraction of the sham exposure effect, 28 GHz appeared to induce stress responses as evidenced by elevated serum-free corticosterone 1 or 3 days after the exposure, which was more evident in animals with a change in rectal temperature exceeding 1 °C. Urinary-free catecholamines demonstrated an inhibitory property of 28 GHz frequency exposure on the stress response as evidenced by noradrenaline on the day of exposure. Heat exposure enhanced this effect, suggesting a possible role of noradrenaline in heat dissipation by promoting cutaneous blood flow, a notion supported by the correlation between noradrenaline levels and tail surface temperature, a critical organ for heat dissipation. CONCLUSIONS This study is the first to demonstrate that qMMW whole-body exposure can alter the stress response as indicated by corticosterone and noradrenaline at near-threshold levels. Our findings may provide insight into the biological basis of the whole-body exposure thresholds in the international guidelines.
Animals ; Rats ; Rats, Sprague-Dawley ; Male ; Restraint, Physical ; Stress, Physiological/radiation effects* ; Corticosterone/blood* ; Biomarkers/blood* ; Microwaves/adverse effects*

OBJECTIVETo study the influences of enhanced UV-B radiation and drought stress on the biomass accumulation and allocation of Fagopyrum dibotrys, and so as to provide a theoretical basis for the cultivation, the protection and use of F. dibotrys.

METHODBy experiment of potted plant, the biomass accumulation and allocation of F. dibotrys were measured under different drought stresses and UV-B radiations.

RESULTIn conditions of adequate water, enhanced UV-B radiation significantly reduced biomass accumulation to root, biomass accumulation to leaves, total biomass accumulation and biomass allocation to root in F. dibotrys, while it could increase biomass allocation to stem. In conditions of moderate drought stress, enhanced UV-B radiation increased biomass accumulation to root, biomass accumulation to stem and biomass accumulation to root. In the conditions of severe drought stress, enhanced UV-B radiation increased biomass accumulation to root, it also could lead in a certain increase to biomass accumulation to stem. Biomass allocation to root, stem and leaves was not sensitive to enhanced UV-B radiation.

CONCLUSIONThe influences of enhanced UV-B radiation in simulation and drought stress on the biomass accumulation and allocation of F. dibotrys were determined by water conditions and different apparatus. Overall, we verified that enhanced UV-B radiation would reduce the influences of biomass accumulation of F. dibotrys by drought.

Biomass ; Droughts ; Fagopyrum ; metabolism ; radiation effects ; Plant Leaves ; metabolism ; radiation effects ; Plant Roots ; metabolism ; radiation effects ; Stress, Physiological ; Time Factors ; Ultraviolet Rays

The present paper is aimed to study the processes of stress reaction and their judgment bases in rat induced by 35 GHz millimeter wave quantitatively. The relative change in the average energy of each EEG frequency band decomposed by wavelet analysis was calculated for extracting the stress indicator for the purpose. The rat would experience quiet period, guarding period, deadlock period and prostrating period in sequence. The judgment bases of different stress periods in rat induced by millimeter wave were obtained by analyzing the skin temperature, skin injury and changes of blood biochemical indexes during each stress period. The stress period changed from quiet period to guarding period when the skin temperature of irradiated area reached the thermal pain threshold. It was from guarding period to deadlock period when the skin had gotten serious injury. Then the rat reaction sensitivity decreased, and injury of its visceral organs occurred. The rat got to prostrating period when the sustained irradiation caused the rat's visceral organs to get more serious injury. The further sustained irradiation finally induced death of the rat.
Animals ; Dose-Response Relationship, Radiation ; Electroencephalography ; radiation effects ; Electromagnetic Radiation ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Skin ; radiation effects ; Skin Temperature ; radiation effects ; Stress, Physiological ; radiation effects

One pair of primers were designed and synthesized based on the cDNA sequence encoding Homo sapiens poly (ADP-ribose) polymerase family, member 10 (PARP10) reported on the GenBank. The cDNA sequence encoding PARP10 was cloned from 293FT cell by RT-PCR. Then the RT-PCR product was cloned into pCMV-Myc and pEGFP-C1 plasmids. The interaction between PARP10 and beta-actin was identified through immuno-precipitation and laser confocal microscopy. Extensive expression of PARP10 in mouse tissues was confirmed by RT-PCR. Besides, Western blotting analysis indicated that cell injury caused by UV treatment could promote the expression of PARP10. The results in this paper would benefit further study of PARP10.
Actins ; metabolism ; Animals ; Humans ; Mice ; Poly(ADP-ribose) Polymerases ; metabolism ; radiation effects ; Protein Interaction Domains and Motifs ; Proto-Oncogene Proteins ; metabolism ; radiation effects ; Stress, Physiological ; radiation effects ; Tissue Distribution ; Ultraviolet Rays