The light environment regulates animal physiology and behaviour. As widely used supplementary heat sources in creep areas, the effect of visible light radiated by infrared heat lamps on pigs is worth investigating. To investigate the effects of light from heat lamps on the behaviour of sows and piglets and possible endocrine mechanisms, 24 primiparous sows were randomly assigned to three supplementary heat source treatments: (1) 250 W non-luminous ceramic heat lamps (CE, n = 8), (2) 175 W red heat lamps (RL, n = 8), and (3) 175 W transparent heat lamps (TL, n = 8). All heat lamps were turned off on Day 15 postpartum. Piglets were weighed on days 3 and 21 postpartum. The number and duration of suckling within 24 h were analysed via video recordings on days 4, 8, and 16 postpartum. Sow posture changes during the day and night were detected using the YOLOv4 target detection network model. One marked piglet from six litters randomly selected from each treatment was used for saliva collection. Saliva samples were collected at 0800, 1400, 2000, and 0200 (+1 d) on days 10 and 20 postpartum. The results showed that the mean postural change frequency of TL sows was higher than that of CE sows (P < 0.05), while that of RL sows was not different from that of CE and TL sows. However, the duration of the sows being in each posture was not affected by the treatment. The total suckling duration of TL piglets was significantly longer than that of CE piglets, but there was no significant difference in the performance of the piglets. The melatonin concentrations in the saliva of piglets at 10 and 20 days of age in the three treatments showed different diurnal rhythms, but there was no significant difference in the levels of melatonin in TL piglets between night and day. Differences in salivary cortisol levels only appeared between the CE and RL groups at 20 days of age. Based on the present results, the illuminance and spectrum of the transparent heat lamps were sufficient to stimulate sow activity and inhibit melatonin levels in piglets. However, the stimulating effect on suckling was not sufficient to significantly improve the performance of piglets. Exposure to red heat lamps, rather than ceramic lamps, resulted in the strongest circadian rhythm of salivary melatonin in piglets. 相似文献
Magnolol and its isomer honokiol are polyphenols with anti-oxidative and anti-inflammatory activities. We evaluated the effects of magnolol and honokiol supplementation alone or in combination with hen diets during the late laying cycle. A total of 540 Jingfen pink-shell laying hens (50 weeks old) were randomly assigned to six treatments: a control diet and diets supplemented with 300 mg/kg magnolol (M300), honokiol (H300), or 300 mg/kg total phenols with a magnolol/honokiol ratio of 2:1 (M200H100), 1:2 (M100H200), and 1:1 (M150H150). Compared with that of the control, all supplementation groups had higher laying rates and the M300, M100H200, and M150H150 groups showed comparatively lower feed conversion ratios. Magnolol and honokiol supplementation increased the Haugh units of fresh eggs at week 62 and alleviated the decline of the Haugh units of eggs stored for 14 days. Compared with that of the control group, the serum total antioxidant capacity of the M100H200 and M150H150 groups significantly increased, and all supplementation groups had higher total antioxidant capacity and lower malondialdehyde content in the liver. With respect to lipid metabolism, the M200H100 and M150H150 groups had lower total and relative liver weights compared with those of the control and H300 groups. The mRNA expression levels of CCAAT enhancer binding protein alpha, sterol regulatory element binding protein-1, fatty acid synthase and stearyl coenzyme A desaturase 1 involved in lipogenesis; microsomal triglyceride transfer protein and apolipoprotein B involved in fatty acid transport; and the proinflammatory cytokine interleukin-1 beta were lower in all supplementation groups compared with those in the control. With respect to gut health, the heights of the jejunum and ileum villi significantly increased in all supplementation groups compared with those of the control, and the jejunum villus heights of the M300 and M150H150 groups were higher than those of the H300 and M100H200 groups. The H300 and M150H150 groups had higher mRNA expression levels of zonula occludens-1 in the ileum compared with those in the control and M300 groups, whereas all supplementation groups had higher mRNA levels of claudin-1 than that of the control group. In conclusion, magnolol and honokiol improved hen performance and the albumen quality of fresh and stored eggs by improving the antioxidant capacity, liver lipid metabolism, and intestinal health of laying hens. The combination of magnolol and honokiol at a 1:1 ratio may be an optimal choice for hen diet supplementation. 相似文献
Ultrasound is widely used in biomedical engineering and has applications in conventional diagnosis and drug delivery. Recent advances in ultrasound-induced drug delivery have been summarized previously in several reviews that have primarily focused on the fabrication of drug delivery carriers. This review discusses the mechanisms underlying ultrasound-induced drug delivery and factors affecting delivery efficiency, including the characteristics of drug delivery carriers and ultrasound parameters. Firstly, biophysical effects induced by ultrasound, namely thermal effects, cavitation effects, and acoustic radiation forces, are illustrated. Secondly, the use of these biophysical effects to enhance drug delivery by affecting drug carriers and corresponding tissues is clarified in detail. Thirdly, recent advances in ultrasound-triggered drug delivery are detailed. Safety issues and optimization strategies to improve therapeutic outcomes and reduce side effects are summarized. Finally, current progress and future directions are discussed.
Heavy metals, that is Cu(II), are harmful to the environment. There is an increasing demand to develop inexpensive detection methods for heavy metals. Here, we developed a yeast biosensor with reduced-noise and improved signal output for potential on-site copper ion detection. The copper-sensing circuit was achieved by employing a secondary genetic layer to control the galactose-inducible (GAL) system in Saccharomyces cerevisiae. The reciprocal control of the Gal4 activator and Gal80 repressor under copper-responsive promoters resulted in a low-noise and sensitive yeast biosensor for copper ion detection. Furthermore, we developed a betaxanthin-based colorimetric assay, as well as 2-phenylethanol and styrene-based olfactory outputs for the copper ion detection. Notably, our engineered yeast sensor confers a narrow range switch-like behaviour, which can give a ‘yes/no’ response when coupled with a betaxanthin-based visual phenotype. Taken together, we envision that the design principle established here might be applicable to develop other sensing systems for various chemical detections. 相似文献
Accumulating research has revealed that erythrocytes play unique roles in the innate immune system. Once thought of as immunologically inert cells, erythrocytes are functional cells that exert diverse immunological effects. Although mature mammal erythrocytes lack internal organelles, they express various receptors, which provide an extraordinary ability for erythrocytes to clear or sequester circulating molecules that affect immune functions. In this review, we elucidate some crucial immunological molecules associated with erythrocytes, such as CR1, CD47, TLR9, and cytokines. CR1 acts as a bridge in clearing off immune complexes and an entrance gate for some pathogens. CD47, once bound to SIRPα, generates an inhibitory signal in macrophage phagocytosis. Reciprocally, erythrocyte CD47 undergoes a conformational change during oxidative stress-induced cellular senescence, subsequently activating phagocytic signals through binding to TSP-1. TLR9 recognizes unmethylated CpG-DNA present in viruses and bacteria. Erythrocyte TLR9 also binds to and eliminates mitochondrial DNA. Erythrocytes can recruit chemokines and modulate plasma chemokine levels through the Duffy antigen receptor for chemokines (DARC). Moreover, erythrocytes may exert immune functions by releasing danger-associated molecular patterns (DAMPs), i.e., heme, IL-33, ATP, and Hsp70. Heme bound with toll-like receptor 4 (TLR4) has the potential to trigger an inflammatory response. Similarly, IL-33, ATP, and Hsp70 from damaged erythrocytes may be involved in the innate immune response via diverse signaling mechanisms. This review provides novel insight into the immunological functions of erythrocytes, which play an irreplaceable role in innate immune responses. We argue that erythrocyte-involved immune function is a widespread area warranting intensive investigation. 相似文献
We have successfully developed a protease assay using fluorescence resonance energy transfer based peptide libraries, which allows not only general detection of enzymatic activities, but more importantly substrate fingerprinting of proteases from different classes. The method allows the generation of substrate fingerprints of a protease from both the nonprime and prime sites. Therefore, it is well suited for profiling of major metalloproteases such as thermolysin and MMPs. We envisage that this method will provide a useful tool in the emerging field of Catalomics for high-throughput studies of proteases. 相似文献