Far-infrared Radiation Research Articles

Near-ultraviolet radiation toward molecular cloud N4 in W 50/SS 433: Evidence for direct interaction of the jet with molecular cloud

Abstract We compared the molecular clouds in the western part of SS 433 with near-ultraviolet radiation data obtained from GALEX. Near-ultraviolet radiation is prominently confirmed toward only N4, while no near-ultraviolet radiation is detected toward N1, N2, or N3. The radiative region of near-ultraviolet radiation is nearly the same as the CO-emitting region in N4, and does not extend beyond the jet seen in X-ray radiation. Near-ultraviolet radiation cannot be explained solely by broad-band continuous radiation and may originate from line emissions. The intensity of near-ultraviolet radiation exhibits an anti-correlation with that of 13CO(J = 3–2) emission. This anti-correlation, along with strong far-infrared radiation in the region with weaker near-ultraviolet radiation intensity compared to its surroundings, suggests that near-ultraviolet radiation originates from behind the molecular cloud, heating up the interstellar dust in N4. Subsequently, the dust in N4 reradiates in the far-infrared band. In the same region, a high peak TMB ratio of 12CO(J = 3–2)$/$12CO(J = 1–0) of ∼0.9, and a high kinetic temperature of Tk ∼ 56 K in the molecular cloud, indicate that CO molecules are highly excited, and the molecular cloud is heated through photoelectric heating. This heating results from electrons released due to the photoelectric effect caused by the phenomenon where interstellar dust absorbs near-ultraviolet radiation. In terms of the timescale of near-ultraviolet radiation originating from line emissions, near-ultraviolet radiation towards N4 cannot be explained by the shock of the blast wave from a supernova that created W 50. These findings also suggest that N4 directly interacts with the jet from SS 433. As a result of this direct interaction, near-ultraviolet radiation is emitted from an interacting layer between the jet and N4.

Far-infrared stimulation of Neiguan acupoints improves heart rate variability and ameliorate fatigue in hemodialysis patients: A randomized trial.

In 2018, 84 615 patients in Taiwan received hemodialysis, of which about 62% to 97% suffered from fatigue. Fatigue caused by hemodialysis may be mental or physical. However, the detailed mechanism remains unclear. This study aimed to evaluate whether far-infrared stimulation of the Neiguan acupoint (P6) could effectively reduce fatigue and improve heart rate variability (HRV) in hemodialysis patients. We conducted a two-arm, randomized trial in a hemodialysis center between March 2015 and March 2016. A total of 73 hemodialysis patients were included and were randomly assigned to an experimental group (n = 37) and a control group (n = 36). The experimental group received far-infrared radiation on Neiguan acupoint during hemodialysis for 12 weeks. The outcomes were fatigue level and HRV. All patients showed moderate fatigue ( M = 26.00 ± 13.01, range = 0-78) at baseline. Far-infrared stimulation on Neiguan acupoint significantly reduced overall fatigue ( β = 24, p < 0.001) and improved HRV ( β = 74.36, p < 0.001). Compared to the control group, the experiment group had significantly reduced fatigue levels in all aspects such as reduced energy and motivation ( β = -2.97, p < 0.001), reduced physical strength ( β = -1.28, p < 0.01), reduced mental capability ( β = -2.38, p < 0.001), reduction in daily activities ( β = -1.48, p < 0.01), depressed mood and loss of control ( β = -1.21, p < 0.05) as well as increased autonomous nervous system activity ( β = 14.71, p < 0.01) in the third month of stimulation. Far-infrared stimulation of the Neiguan acupoints effectively reduces fatigue and increases autonomic nervous system activity in hemodialysis patients.

Hyperspectral Remote Sensing Technology of Far-Infrared Radiation and Its Application in Ice Cloud Retrievals (Invited)

Hyperspectral Remote Sensing Technology of Far-Infrared Radiation and Its Application in Ice Cloud Retrievals (Invited)

Quantitative analysis of wavelength dependence of thermal perception

In recent years, significant progress has been made in the development of materials that selectively reflect or absorb radiation in specific wavelength ranges. Previous studies have shown that the same intensity of radiation can produce different degrees of thermal perception depending on its wavelength. This difference is thought to be the optical properties of the skin. However, these findings have not been quantitatively verified yet. The purpose of this study is to quantitatively analyze the effects of radiation of different wavelength ranges on thermal sensation. We conducted a human subject experiment and discovered that far-infrared radiation causes a warmer and more uncomfortable sensation than near-infrared radiation. To interpret these results, we developed a new mathematical model that predicts thermal perception caused by radiation of different wavelengths. The model is based on a heat diffusion equation within the skin and considers the optical properties of the skin to simulate thermoreceptor activities in response to given spectral irradiances. Our model explained the observed phenomenon in our and previous experiments, where the same intensity of radiation but at different wavelengths can produce different degrees of thermal perception, in terms of physiological mechanisms. Additionally, the model revealed a hierarchy in thermal sensation, with far-infrared radiation being perceived as the warmest, followed by mid-infrared, visible, and near-infrared radiation. These findings are crucial for designing materials that selectively reflect or absorb radiation in specific wavelength ranges, and for developing heaters that provide efficient heating with low energy consumption.

SUNRISE: The rich molecular inventory of high-redshift dusty galaxies revealed by broadband spectral line surveys

Understanding the nature of high-redshift dusty galaxies requires a comprehensive view of their interstellar medium (ISM) and molecular complexity. However, the molecular ISM at high redshifts is commonly studied using only a few species beyond 12C16O, limiting our understanding. In this paper, we present the results of deep 3 mm spectral line surveys using the NOrthern Extended Millimeter Array (NOEMA) targeting two strongly lensed dusty galaxies observed when the Universe was less than 1.8 Gyr old: APM 08279+5255, a quasar at redshift z = 3.911, and NCv1.143 (H-ATLAS J125632.7+233625), a z = 3.565 starburst galaxy. The spectral line surveys cover rest-frame frequencies from about 330 to 550 GHz for both galaxies. We report the detection of 38 and 25 emission lines in APM 08279+5255 and NCv1.143, respectively. These lines originate from 17 species, namely CO, 13CO, C18O, CN, CCH, HCN, HCO+, HNC, CS, C34S, H2O, H3O+, NO, N2H+, CH, c-C3H2, and the vibrationally excited HCN and neutral carbon. The spectra reveal the chemical richness and the complexity of the physical properties of the ISM. By comparing the spectra of the two sources and combining the analysis of the molecular gas excitation, we find that the physical properties and the chemical imprints of the ISM are different: the molecular gas is more excited in APM 08279+5255, which exhibits higher molecular gas temperatures and densities compared to NCv1.143; the molecular abundances in APM 08279+5255 are akin to the values of local active galactic nuclei (AGN), showing boosted relative abundances of the dense gas tracers that might be related to high-temperature chemistry and/or the X-ray-dominated regions, while NCv1.143 more closely resembles local starburst galaxies. The most significant differences between the two sources are found in H2O: the 448 GHz ortho-H2O(423 − 330) line is significantly brighter in APM 08279+5255, which is likely linked to the intense far-infrared radiation from the dust powered by AGN. Our astrochemical model suggests that, at such high column densities, far-ultraviolet radiation is less important in regulating the ISM, while cosmic rays (and/or X-rays and shocks) are the key players in shaping the molecular abundances and the initial conditions of star formation. Both our observed CO isotopologs line ratios and the derived extreme ISM conditions (high gas temperatures, densities, and cosmic-ray ionization rates) suggest the presence of a top-heavy stellar initial mass function. From the ∼330–550 GHz continuum, we also find evidence of nonthermal millimeter flux excess in APM 08279+5255 that might be related to the central supermassive black hole. Such deep spectral line surveys open a new window into the physics and chemistry of the ISM and the radiation field of galaxies in the early Universe.

Preparation and Characterization of High-Performance Composite Coatings Compatible with Near-Infrared Low Reflectivity and Low Infrared Emissivity

Polyurethane (PU)/Al-graphene composite coating with low infrared emissivity, a low near-infrared reflectivity of 1.06 μm, and satisfactory mechanical properties was prepared by using Al powder and graphene as composite pigments and PU as a binder, respectively. The study investigated the impact of the mass ratio of graphene to Al powder, as well as the total addition of functional fillers (Al powder and graphene), on infrared emissivity and near-infrared reflectivity, and the mechanical properties of the coating were studied. The results show that a large number of conjugated systems in the molecular structure of graphene can produce strong absorption of near-infrared radiation, allowing for the coating to exhibit low reflectivity at 1.06 μm in near-infrared radiation. The flake Al powder, with good electrical conductivity, can create a strong reflection in the 8–14 μm far-infrared radiation range, resulting in low emissivity and providing the coating with good infrared and laser-compatible stealth performance. By adjusting the mass ratio of graphene to Al powder, the infrared emissivity at 8–14 μm can be tuned from 0.371 to 0.644, and the reflectivity at 1.06 μm can be adjusted from 22.9% to 61.6%. Additionally, the coatings demonstrate satisfactory mechanical properties, with adhesion strength, flexibility, and impact strength reaching grade 1, 2 mm, and 50 kg · cm, respectively, for coatings with different mass ratios of graphene to Al powder. The PU/Al-graphene composite coating can be regarded as a new type of infrared and laser compatible stealth coating with good functional and mechanical properties.

Effect of ultrasonic power on moisture migration and microstructure of contact ultrasound enhanced far-infrared radiation drying on taro slices

Effect of ultrasonic power on moisture migration and microstructure of contact ultrasound enhanced far-infrared radiation drying on taro slices

Effects of stabilization combined with fermentation treatments on the volatile composition and flavor profile of cooked black rice

Superheated steam (SS) or far infrared radiation (FIR) stabilization combined with solid-state fermentation were applied to improve the flavor profile of cooked black rice. E-nose data showed that different cooked black rice samples had similar flavor profiles, and fermentation increased volatiles contents. Besides, a total of 84 volatiles were identified by HS-SPME-GC-MS, and cooked rice of single fermented black rice (FBR) showed the highest total content of volatiles, while cooked rice of fermented FIR stabilized black rice (FSBR-FIR) had the richest varieties of volatiles. Furthermore, 21 out of 84 volatiles were screened as key volatiles by odor activity value (OAV) analysis. Afterwards, naphthalene, nonanal, indole, (E, E)-2, 4-decadienal, eugenol, 2-pentylfuran, (E)-citral, (2E)-2-decenal were screened as differential key volatiles via combination of OAV analysis and partial least squares-discriminant analysis (PLS-DA). It was worth noting that the contents of unpleasant volatiles (indole and eugenol) were the poorest in the cooked rice of FSBR-FIR, while the contents of pleasant volatiles (nonanal, (E, E)-2, 4-decadienal, 2-pentylfuran, and (2E)-2-decenal) were the richest in the cooked rice of FSBR-FIR. The above results suggested that FIR stabilization combined with solid-state fermentation was the most valued to improve the flavor profile of cooked black rice.

Influence of Processing Conditions on the Generation of Surface Defects in a Heat-and-Cool Hybrid Injection Molding Technique for Carbon Fiber-Reinforced Thermoplastic Sheets and Development of a Suitable Mold Heated by Far-Infrared Radiation.

Recently, hybrid injection molding-a type of overmolding technology in which a short carbon fiber-reinforced thermoplastic is injection molded over a compression-molded carbon fiber-reinforced thermoplastic (CFRTP) sheet-has been introduced. A heat-and-cool hybrid injection molding technique has also been introduced for practical use. The technique yields high-quality molded products. This is achieved through the heating of the mold cavity surface to a temperature higher than the melting point of the base polymer impregnated into the carbon fiber fabric. However, few experimental analyses of the molding phenomena in heat-and-cool hybrid injection molding have been reported. In particular, the effect of the processing conditions on the transfer of the mold cavity surface shape to the CFRTP sheet has not been clarified in detail. Therefore, it has been impossible to take extensive measures when defects are generated in molded products. In this study, a mold is designed and fabricated for use with far-infrared radiation heating, a variotherm technology that is suitable for the experimental analysis of the heat-and-cool hybrid injection molding phenomenon. In particular, a mold is designed and fabricated to continuously perform the following three processes using only an injection molding machine: (1) the radiation heating of both the CFRTP sheet and the mold cavity surface using a far-infrared radiation heater, (2) the compression molding of the CFRTP sheet, and (3) the injection molding of the melt. The effects of the heating conditions of the mold and the injection molding process conditions on the appearance characteristics of the molded products are clarified using this mold and a far-infrared radiation heater.

Improving tomato yield, quality and antioxidant capacity in greenhouse by far-infrared radiation

Far-infrared radiation is known as the "light of life". To investigate if it has positive effects on tomatoes and the proper location and time period of the far-infrared treatment. This study adopted tomato 'Taiji No.1′ as the plant material with 8 μm-14 μm far-infrared treatments. The results found that far-infrared radiation can significantly increase antioxidant capacity of senescent leaves. The proper location of the far-infrared lines was placed at the root and growth layer of the plant, which enhanced the net photosynthetic rate of plants by 44.01 % compared with the CK (no far-infrared treatment). It also promoted fruit ripening and increased the yield by 20.25 % compared with the CK. For the time period, far-infrared treatment during the periods of 6:00–9:00 am (gradual increase in photosynthesis) and 15:00–18:00 pm (gradual decrease in photosynthesis) (DT6) showed the optimum effect, which even surpassed 24 h and 16 h far-infrared treatments. The net photosynthetic rate of DT6 increased by 31.05 % compared with the CK (no far-infrared treatment). Among all the treatments, DT6 had the highest soluble sugar, fructose, and glucose contents. Among the common aroma compounds of tomato, sweet-related compounds were higher in the far-infrared treatment group than in the CK. DT6 treatment also had the highest yield and profit margin.

Effects of far-infrared radiation on the gelatinized rice starch granules

A prototype far-infrared (FIR) dryer was developed to study the effects of far-infrared radiation on physicochemical properties changes of rice flour and energy consumption for gelatinization. A thin layer of rice flour was exposed to different FIR intensities (11.2, 8.5, and 7.8 kW m−2) and different time intervals (2–16 s). The degree of gelatinization, viscosity changes, color changes, acidity changes during storage, and energy consumption for gelatinization were measured. The degree of gelatinization, color changes, and viscosity increased with FIR intensity and exposure time. Gelatinized rice flour showed significantly (p < 0.05) lower acidity development compared to non-gelatinized flour during storage. The drying rate increased, and specific energy consumption decreased with increasing FIR intensity. It was found that optimum gelatinization can be achieved at 11.2 kW m−2 FIR intensity for 16 s. All these results confirm that FIR is an effective source of rice flour roasting.

A stable all-day interfacial evaporation multistage distillation driven by solar photothermal and solar electrothermal

Solar-powered interface vapor generation offers a promising approach to sustainable desalination. However, the diurnal nature of solar energy leaves evaporators idles for nearly half their lifetime. Existing evaporators that set electricity as an auxiliary energy source for nighttime evaporators have a series of electrochemical problems, such as short circuits, corrosion, and water electrolysis, making it difficult to achieve continuous and stable freshwater production. Here, we designed solar absorbers by modifying carbon black (CB) on the far-infrared radiation paper (FIRP) surface for simultaneous photothermal conversion and joule heating. The absorber is further set in a multistage distillation (MSD) device for interfacial evaporation and latent heat recovery. The MSD device is designed with mutually insulated circuitry and water transfer paths to avoid electrochemical reactions within the device fundamentally. As a result, the MSD device achieved evaporation rates of 2.2 and 2.5 kg m-2h−1 at 1 kW m−2 solar-driven and electric-driven inputs, respectively. In particular, the MSD device achieved a continuous and stable operation of 240 h under alternating solar and electric drive. This method provides a new idea for the long-term continuous operation of interfacial evaporators.

Effect of far-infrared radiation therapy on von Willebrand factor in patients with chronic kidney disease.

Hemostatic abnormality has contributed to vascular access thrombosis in patients with chronic kidney disease (CKD). Previous studies have demonstrated that far-infrared radiation (FIR) therapy can maintain the patency and maturity of arteriovenous fistulas of patients undergoing hemodialysis (HD). However, prolonged access bleeding is observed once FIR is conducted at the end of dialysis. FIR can block the binding of platelet and von Willebrand factor (vWF), a predictor of hemostatic abnormality and vascular access thrombosis. However, clinical studies exploring FIR and vWF are sparse. We recruited 20 HD patients, 21 CKD patients, and 20 controls to examine the alteration of vWF and a disintegrin and metalloproteinase with thrombospondin type 1 repeats 13 (ADAMTS13) following a single 40-min session of FIR therapy. In addition, the alteration of these factors in the HD group was examined following a 40-min FIR session thrice a week for 3 months. A decreasing trend in the vWF activity-antigen ratio of participants in all groups following a single FIR session was observed. In addition, the ratio in the HD group was significantly lower following 3 months of FIR therapy. The subgroup analysis revealed a consistent trend and multiple regression analysis showed that participants not taking hydroxymethylglutaryl-coenzyme A reductase inhibitor, diabetes mellitus, and higher hemoglobin levels were the significant factors. The alteration of the vWF activity-antigen ratio correlated moderately to that of ADAMTS13 antigen and activity. FIR may alter the ratio of ultra-large vWF multimers through ADAMTS13, contributing to inhibiting platelet-endothelium interactions of CKD patients.

Effect of combined convective hot air and far-infrared radiation on physic-chemical aspects of black raspberry powder produced by foam mat method

In recent years the use of hybrid drying methods has been noticed because of the improvement of the dried products quality. The effect of infrared (IR) power (0, 400, 600, and 800 W) in combination with convective hot air (60 °C, 3 m/s) on the quality properties of black raspberry pulp during foam mat drying was investigated in this study. According to the findings, increasing the IR power, (IR-CHA) had no effect on the moisture content, moisture ratio, or drying rate of the product; however, the effective moisture diffusion coefficient (Deff) was significantly increased. The effect of IR power on the physicochemical properties of black raspberry powder revealed that combining infrared with convective hot air (IR-CHA) improved the powder's flowability and total polyphenol content while decreasing its moisture content (p < 0.05). Furthermore, FESEM images revealed that the increase in IR power resulted in particles with smooth surfaces.

Systematic Review and Meta-Analysis of Non-Invasive Acupoint Therapy as an Approach to Urinary Itching Control in Dialysis Patients

Uremic pruritus, one of the most painful symptoms experienced by patients receiving dialysis, seriously affects patient quality of life and health, causes physical and mental damage, and increases hospitalization and mortality rates. Multi-modal therapies with evidence-based healthcare are needed to provide patients receiving dialysis with more convenient and feasible medical resources. Relevant domestic and international research on the effectiveness and methods of non-invasive acupoint therapy in improving uremic pruritus in dialysis patients was reviewed. Discussing related knowledge can facilitate the evidence-based use of non-invasive acupoint therapy in clinical practice by clinical medical personnel. Based on the PRISMA (preferred reporting items for systematic reviews and meta-analyses) systematic literature review and integrated analysis method, a keyword search of related articles published before September 2023 was conducted in the following databases: PubMed, Cochrane Library, Embase, Web of Science, Airiti Library, Taiwan Master and Doctoral Dissertation System, Chinese Journal Full-text Database and Wanfang Data Knowledge Service Platform. In 2019, the second version of the Risk of Bias Tool for Randomized Controlled Trials was used to evaluate research quality, after which RevMan 5.4 and Stata 14.0 suite software were used for meta-analysis. Nine of the 112 articles selected, including 10 sets of data and 597 participants, were included in the meta-analysis. The results indicate non-invasive acupoint therapy significantly reduces the degree of uremic pruritus (synthetic effect size = -1.30, 95% confidence interval [-1.67, -0.93], p < .00001). Because the heterogeneity test I² = 76%, showed a high degree of heterogeneity, a subgroup analysis was performed, showing that acupoint massage combined with traditional Chinese medicine fumigation and washing, a general simple itching assessment scale, and the Chinese region achieved better effect sizes. Non-invasive acupoint therapy is easy to implement, inexpensive, non-invasive, and associated with few side effects. The authors hope these findings may increase the awareness and understanding of patients with dialysis regarding the practical operation techniques of itching acupoints. According to the results of this systematic review and meta-analysis, massage of the lung and endocrine acupoints at ST-6, SP-10, and LI-11 as well as the relevant points on the ear may be most effective in achieving urinary itching relief. Also, acupoint massage combined with traditional Chinese medicine fumigation, ST-6 far-infrared irradiation, or LI11 transcutaneous acupoint electrical stimulation can further relieve uremic pruritus in this patient population. Based on the results, acupoint massage combined with traditional Chinese medicine fumigation and washing is a complementary method of treatment for uremic pruritus that may be recommended to patients in the future.

Revealing the intrinsic nature of Eu-doped lead phosphate: A study using density functional theory

Eu3+-doped oxide glasses have received significant research interest due to their luminescent, photoluminescent, and radiation shielding properties, resulting in their application in the nuclear industry. In this work, the structural, electronic, optical, and vibrational properties of two new materials, lead phosphate doped with europium (PbxP8O26:Eu) with x=5 and 6, were investigated using density functional theory with a short-range order description similar to that of crystalline solids. The bandgap energies calculated for the structures with Eu3+ as substitution (x=5) or interstitial (x=6) point defects were 3.5 eV and 1.5 eV, respectively. The structural arrangement and the density of states revealed atomic disorder in both structures, that is, evidence of amorphization. The bandgap energies obtained from the state density calculations agree with those of the ultraviolet–visible (UV–Vis) absorption between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The UV–Vis spectral signature indicated that the structures are sensitive to UV-C and far-infrared radiation. The vibrational spectra showed a correspondence between the respective bands and the modes of the systems, corroborating the results reported in other works that investigated Eu3+-doped oxide glasses. Both materials showed amorphous features. Our results suggest that both investigated structures can be used as photodetectors, as well as shielding devices for materials exposed to UV-C radiation.

The OH Megamaser emission in Arp 220: the rest of the story

ABSTRACT The OH Megamaser emission in the merging galaxy Arp 220 has been re-observed with the Multi-Element Radio Linked Interferometer Network (MERLIN) and the European VLBI Network (EVN). Imaging results of the OH line emission at the two nuclei are found to be consistent with earlier observations and confirm additional extended emission structures surrounding the nuclei. Detailed information about the distributed emission components around the two nuclei has been obtained using a concatenated MERLIN and EVN database with intermediate (40 mas) spatial resolution. Continuum imaging shows a relatively compact West nucleus and a more extended East nucleus in addition to an extended continuum ridge stretching below and beyond the two nuclei. Spectral line imaging show extended emission regions at both nuclei together with compact components and additional weaker components north and south of the West nucleus. Spectral line analysis indicates that the dominant OH line emission originates in foreground molecular material that is part of a large-scale molecular structure that engulfs the whole nuclear region. Compact OH components are representative of star formation regions within the two nearly edge-on nuclei and define the systemic velocities of East and West as 5425 and 5360 km s−1. The foreground material at East and West has a 100 km s−1 lower velocity at 5314 and 5254 km s−1. These emission results confirm a maser amplification scenario where the background continuum and the line emission of the star formation regions are amplified by foreground masering material that is excited by the far-infrared radiation field originating in the two nuclear regions.

Effect of ultrasonic power on moisture migration and microstructure of contact ultrasound enhanced far-infrared radiation drying on taro slices

To clarify the moisture migration and microstructure of taro in contact ultrasound enhanced far-infrared radiation drying (CUFRD), low-field nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), paraffin sectioning and microscopic observation techniques were applied to explore the changes of the drying curves, water status, microstructure, porosity, microscopic images and distribution curves of cell microstructure parameters of taro under different ultrasound powers of 0, 40, and 80 W. The results showed that applying contact ultrasound (CU) during drying was beneficial to accelerating the dehydration process and improving the porosity of taro slice. With the augment of CU power, the drying times of taro reduced by 16.67% to 25.00%, and the effective water diffusion coefficient was improved by 14.72% to 31.38%. In addition, the application of CU resulted in an increase firstly and then decrease in the cross-sectional area and perimeter distribution curves of taro cells and a widening of the peak shape of the distribution curve of taro cell roundness. In conclusion, CU application could cause faster internal moisture migration, and higher CU power had more obvious effect on microstructure and cell morphological parameters of taro during CUFRD.

Preparation and characteristics of pumpkin polysaccharides and their effects on abnormal glucose metabolism in diabetes mice

Oxidative stress is frequently implicated in the pathogenesis of various diseases, including diabetes mellitus resulting from uncontrolled glucose metabolism. Pumpkin polysaccharides have been shown to have a hypoglycemic effect, but their impact on abnormal glucose metabolism under oxidative stress is still unclear. We dried pumpkin flesh by far-infrared radiation, extracted and separated pumpkin polysaccharides from the dried flesh, and found that they were heteropolysaccharides primarily composed of galacturonic acid, glucose, galactose, and arabinose, with a molar ratio of 31.68:31.81:20.18:9.752. The number average (Mn) and weight average molecular weight (Mw) of pumpkin polysaccharides were 33.72 kDa and 70.88 kDa, respectively. The hemiacetal hydroxyl group forming the glycosidic bond in polysaccharides was mainly β-configuration. Additionally, we utilized streptozotocin (STZ) to induce oxidative stress and replicate an acute diabetic mouse model to study the effects of pumpkin polysaccharides on abnormal glucose metabolism. Our findings demonstrated pumpkin polysaccharides significantly reduced the levels of blood glucose, triglycerides (TG), and total cholesterol (TC) in diabetic mice (p < 0.05). Additionally, pumpkin polysaccharides significantly increased the activities of superoxide dismutase (SOD), catalase (CAT) and the level of the antioxidant glutathione (GSH) (p < 0.05), and decreased the content of the lipid peroxide malondialdehyde (MDA) in the liver (p < 0.05). Pumpkin polysaccharides also increased the activity of pyruvate kinase (PK) and decreased the activity of phosphoenolpyruvate carboxykinase (PEPCK) in the liver (p < 0.05). In conclusion, our study demonstrated pumpkin polysaccharides alleviate hyperglycemic symptoms in mice by mitigating oxidative stress damage and improving glucose metabolism disorders.

FAR-INFRARED IRRADIATION INHIBITS CELL PROLIFERATION IN BASAL AND PDGF-STIMULATED RAT VASCULAR SMOOTH MUSCLE CELLS THROUGH REGULATION AMPK/MTOR/P70S6K SIGNALING AXIS

Objective: Far-infrared (FIR) rays are invisible electromagnetic radiation with a wavelength of 3-1000 um, which elicits molecular vibrations in water and other organic molecules in cells and tissues, thereby FIR rays may have various biological effects. Aberrant proliferation of vascular smooth muscle cells (VSMCs) is associated with the development of diverse vascular diseases including atherosclerosis. Although FIR irradiation is reported to inhibit cell proliferation in various types of cells, effect of FIR irradiation on VSMC proliferation and the underlying mechanism remain elusive. Here, we investigated the molecular mechanism by which FIR irradiation inhibited VSMC proliferation. Design and method: We performed cell proliferation and viability assay, inhibitor studies, transfection of dominant negative (dn)-AMP-activated protein kinase (AMPK) alpha 1 gene, and western blot analyses. We also conducted confocal microscopic image analyses and ex vivo studies using isolated rat aortas. Results: FIR irradiation for 30 min decreased VSMC proliferation with no alteration in cell viability, which was accompanied by decreased phosphorylation of mammalian target of rapamycin (mTOR) at Ser2448 (p-mTOR-Ser2448) and p70 S6 kinase (p70S6K) at Thr389 (p-p70S6K-Thr389). Furthermore, FIR irradiation increased phosphorylation of AMP-activated protein kinase (AMPK) at Thr172 (p-AMPK-Thr172). Pre-treatment with compound C, a specific AMPK inhibitor, or ectopic expression of dn-AMPK alpha 1 gene, significantly reversed FIR irradiation-decreased VSMC proliferation, p-mTOR-Ser2448, and p-p70S6K-Thr389. However, hyperthermal stimulus (39 degrees) did not change VSMC proliferation and AMPK/mTOR/p70S6K phosphorylation. Similar to in vitro results, FIR irradiation increased p-AMPK-Thr172, and decreased p-mTOR-Ser2448 and p-p70S6K-Thr389 in isolated rat aortas. Finally, FIR irradiation attenuated platelet-derived growth factor (PDGF)-stimulated VSMC proliferation by increasing p-AMPK-Thr172, and decreasing p-mTOR-Ser2448 and p-p70S6K-Thr389 in PDGF-induced in vitro atherosclerosis model. Conclusions: We demonstrate that FIR irradiation decreases VSMC proliferation, at least in part, by regulating AMPK/mTOR/p70S6K signaling axis. These observations suggest that FIR ray therapy can be used to treat arterial narrowing diseases including atherosclerosis and in-stent restenosis.