Mitigating cadmium accumulation in dicotyledonous vegetables by iron fertilizer through inhibiting Fe transporter IRT1-mediated Cd uptake.

The solubility of cadmium (Cd) in soil and its transfer to plants are influenced by soil pH. While increasing soil pH reduces Cd solubility and accumulation in rice plants grown in acidic soils, its effect on Cd accumulation in vegetables remains inconclusive. Here, we investigated the impact of soil pH on Cd accumulation in dicotyledonous vegetables and elucidated the underlying molecular mechanisms. Soils collected from various locations were supplemented with varying quantities of lime to achieve soil pH values of around 5.0, 6.0, 7.0, and 8.0. Raising soil pH from around 5.0 to 8.0 markedly decreased extractable Cd. However, increasing soil pH tended to promote shoot Cd accumulation in dicotyledonous vegetable species including lettuce, pakchoi, and Chinese cabbage, and the model dicotyledonous plant Arabidopsis thaliana. Conversely, soil pH increase resulted in a monotonic decrease in rice Cd accumulation. In our hydroponic experiments, we discovered that iron (Fe) deficiency substantially increased Cd uptake and accumulation in dicotyledonous plants but not in rice. Increasing soil pH reduced soil Fe availability and induced the Fe transporter gene IRT1 expression in dicotyledonous vegetables roots, which led to an increase in IRT1-mediated Cd uptake and subsequently increased Cd accumulation as soil pH increases. A comprehensive model incorporating extractable Cd and root IRT1 expression better explained Cd accumulation in vegetable shoots. The application of 50 mg/kg of Fe fertilizer in neutral or alkaline soils resulted in a significant reduction in Cd accumulation by 34-58% in dicotyledonous vegetables. These findings reveal that increasing soil pH has two opposite effects, decreasing soil Cd availability while promoting Cd uptake through IRT1 upregulation, reconciling the inconsistency in its effect on Cd accumulation in dicotyledonous plants. Our findings provide important insights for understanding the factors affecting Cd uptake in plants and offer a practical solution to mitigate Cd contamination in vegetables.

Recent Advances in Tailored Fabrication and Properties of Biobased Self-Healing Polyurethane.

With the emergence of challenges in the environmental degradation and resource scarcity fields, the research of biobased self-healing polyurethane (BSPU) has become a prevailing trend in the technology of the polyurethane industry and a promising direction for developing biomass resources. Here, the production of BSPU from lignocellulose, vegetable oil, chitosan, collagen, and coumarin is classified, and the principles of designing polyurethane based on compelling examples using the latest methods and current research are summarized. Moreover, the impact of biomass materials on self-healing and mechanical properties, as well as the tailored performance method, are presented in detail. Finally, the applications of BSPU in biomedicine, sensors, coatings, etc. are also summarized, and the possible challenges and development prospects are explored to helpfully make progress in the development of BSPU. These findings demonstrate valuable references and practical significance for future BSPU research.

Photopolymerizable, immunomodulatory hydrogels of gelatin methacryloyl and carboxymethyl chitosan as all-in-one strategic dressing for wound healing.

Microenvironment regeneration in wound tissue is crucial for wound healing. However, achieving desirable wound microenvironment regeneration involves multiple stages, including hemostasis, inflammation, proliferation, and remodeling. Traditional wound dressings face challenges in fully manipulating all these stages to achieve quick and complete wound healing. Herein, we present a VEGF-loaded, versatile wound dressing hydrogel based on gelatin methacryloyl (GelMA) and carboxymethyl chitosan (CMCS), which could be easily fabricated using UV irradiation. The newly designed GelMA-CMCS@VEGF hydrogel not only exhibited strong tissue adhesion capacity due to the interactions between CMCS active groups and biological tissues, but also possessed desirable extensible properties for frequently moving skins and joints. Furthermore, the hydrogel demonstrates exceptional abilities in blood cell coagulation, hemostasis and cell recruitment, leading to the promotion of endothelial cells proliferation, adhesion, migration and angiogenesis. Additionally, in vivo studies demonstrated that the hydrogel drastically shortened hemostatic time, and achieved satisfactory therapeutic efficacy by suppressing inflammation, modulating M1/M2 polarization of macrophages, significantly promoting collagen deposition, stimulating angiogenesis, epithelialization and tissue remodeling. This work contributes to the design of versatile hydrogel dressings for rapid and complete wound healing therapy.

Application of Oxygen-Group-Based Amorphous Nanomaterials in Electrocatalytic Water Splitting.

Environmentally friendly energy sources (e.g., hydrogen) require an urgent development targeting to address the problem of energy scarcity. Electrocatalytic water splitting is being explored as a convenient catalytic reaction in this context, and promising amorphous nanomaterials (ANMs) are receiving increasing attention due to their excellent catalytic properties.Oxygen group-based amorphous nanomaterials (O-ANMs) are an important component of the broad family of ANMs due to their unique amorphous structure, large number of defects, and abundant randomly oriented bonds, O-ANMs induce the generation of a larger number of active sites, which favors a better catalytic activity. Meanwhile, amorphous materials can disrupt the inherent features of conventional crystalline materials regarding electron transfer paths, resulting in higher flexibility. O-ANMs mainly include VIA elements such as oxygen, sulfur, selenium, tellurium, and other transition metals, most of which are reported to be free of noble metals and have comparable performance to commercial catalysts Pt/C or IrO2 and RuO2 in electrocatalysis. This review covers the features and reaction mechanism of O-ANMs, the synthesis strategies to prepare O-ANMs, as well as the application of O-ANMs in electrocatalytic water splitting. Last, the challenges and prospective remarks for future development in O-ANMs for electrocatalytic water splitting are concluded.

Correction: Recent advances in self-healing polyurethane based on dynamic covalent bonds combined with other self-healing methods.

Correction for 'Recent advances in self-healing polyurethane based on dynamic covalent bonds combined with other self-healing methods' by Ze-Wei An et al., Nanoscale, 2023, 15, 6505-6520, https://doi.org/10.1039/D2NR07110J.

Recent advances in self-healing polyurethane based on dynamic covalent bonds combined with other self-healing methods.

To meet more application requirements, improving mechanical properties and self-healing efficiency has become the focus of current research on self-healing PU. The competitive relationship between self-healing ability and mechanical properties cannot be avoided by a single self-healing method. To address this problem, a growing number of studies have combined dynamic covalent bonding with other self-healing methods to construct the PU structure. This review summarizes recent studies on PU materials that combine typical dynamic covalent bonds with other self-healing methods. It mainly includes four parts: hydrogen bonding, metal coordination bonding, nanofillers combined with dynamic covalent bonding and multiple dynamic covalent bond bonding. The advantages and disadvantages of different self-healing methods and their significant role in improving self-healing ability and mechanical properties in PU networks are analyzed. At the same time, the possible challenges and research directions of self-healing PU materials in the future are discussed.

Inner filter effect-based red-shift and fluorescence dual-sensor platforms with sulfur quantum dots for detection and bioimaging of alkaline phosphatase.

Alkaline phosphatase (ALP), one of the vital biomarkers in several diseases, plays a role in indicating disease presence or severity in early diagnosis. Here, a simple H2O2 assisted top-down method was used to synthesize sulfur quantum dots (SQDs) with excitation and emission at 355 nm and 440 nm. Adding ALP into p-nitrophenyl phosphate (p-NPP) and SQDs was found to exhibit a red shift in the emission wavelength and fluorescence intensity quenching of SQDs, respectively, allowing us to propose dual-sensor platforms of red shift of emission wavelength (RSEW) and fluorescence quenching of SQDs. These dual-sensor platforms were highly sensitive and selective in ALP detection, with a linear response to ALP in the concentration range of 0.25 to 100 U L-1 and detection limits of 0.08 and 0.10 U L-1, respectively. The absorption of p-NP at 400 nm showed a good overlap with the excitation and emission of SQDs, leading to inner filter effect-based RSEW and fluorescence quenching of SQDs. This sensor platform was successfully applied in ALP sensing of serum samples as well as monitoring of ALP in cells. More importantly, this platform can serve as an example of using RSEW to detect ALP.

Validity and reproducibility of a FFQ for assessing dietary intake among residents of northeast China: northeast cohort study of China.

The study was to evaluate the reproducibility and validity of the FFQ for residents of northeast China. A total of 131 participants completed two FFQ (FFQ1 and FFQ2) within a 3-month period, 125 participants completed 8-d weighed diet records (WDR) and 112 participants completed blood biomarker testing. Reproducibility was measured by comparing nutrient and food intake between FFQ1 and FFQ2. The validity of the FFQ was assessed by WDR and the triad method. The Spearman correlation coefficients (SCC) and intraclass correlation coefficients (ICC) for reproducibility ranged from 0·41 to 0·69 (median = 0·53) and from 0·18 to 0·68 (median = 0·53) for energy and nutrients and from 0·37 to 0·73 (median = 0·59) and from 0·33 to 0·86 (median = 0·60) for food groups, respectively. The classifications of same or adjacent quartiles ranged from 73·64 to 93·80 % for both FFQ. The crude SCC between the FFQ and WDR ranged from 0·27 to 0·55 (median = 0·46) for the energy and nutrients and from 0·26 to 0·70 (median = 0·52) for food groups, and classifications of the same or adjacent quartiles ranged from 65·32 to 86·29 %. The triad method indicated that validation coefficients for the FFQ were above 0·3 for most nutrients, which indicated a moderate or high level of validity. The FFQ that was developed for residents of northeast China for the Northeast Cohort Study of China is reliable and valid for assessing the intake of most foods and nutrients.

Research Update of Emergent Sulfur Quantum Dots in Synthesis and Sensing/Bioimaging Applications.

Due to their unique optical property, low toxicity, high hydrophilicity, and low cost, sulfur quantum dots (SQDs), an emerging luminescent nanomaterial, have shown great potential in various application fields, such as sensing, bioimaging, light emitting diode, catalysis, and anti-bacteria. This minireview updates the synthetic methods and sensing/bioimaging applications of SQDs in the last few years, followed by discussion of the potential challenges and prospects in their synthesis and sensing/bioimaging applications, with the purpose to provide some useful information for researchers in this field.

A new species of Notacanthella Jacobus & McCafferty, 2008 (Ephemeroptera, Ephemerellidae) from Yunnan, China.

Notacanthellajinwu Li & Jacobus, sp. nov. is described based on egg, nymph, and winged stages from Dali Bai Autonomous Prefecture, Yunnan Province, China. The nymph of the new species is closely related to N.commodema (Allen, 1971), whose nymphs share a similar tuberculation of head, pronotum, and mesonotum. However, the nymph of our new species can be distinguished based on the structures of male sternum IX and abdominal tergal tubercles. In addition, the new species is distributed in subtropical high-altitude areas. The description of the male imago of the new species is the first certain one for the genus Notacanthella. Data associated with our new species allow for expanded discussion and diagnosis of Notacanthella and closely related genera. An identification key for nymphs of these groups is provided.

Synthesis of a series of validoxylamine A esters and their biological activities.

BACKGROUND: The worldwide reduction in food production due to pests and diseases is still an important challenge facing today. Validoxylamine A (VAA) is a natural polyhydroxyl compound derived from validamycin, acting as an efficient trehalase inhibitor with insecticidal and antifungal activities. To extend the application and discover green pesticide, a series of ester derivatives were prepared based on VAA as a lead compound. Their biological activities were investigated against three typically agricultural disease, Rhizoctonia solani, Sclerotinia sclerotiorum and Aphis craccivora. RESULTS: This study involved 30 novel validoxylamine A fatty acid esters (VAFAEs) synthesized by Novozym 435 and they were characterized with high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and proton nuclear magnetic resonance (1 H-NMR). Of these 30 derivatives, most compounds showed improved antifungal activity, and 12 novel compounds showed improved insecticidal activity. When reacted with pentadecanoic acid, compound 14 showed the highest inhibitory activity against R. solani [median effective concentration (EC50 ) 0.01 µmol L-1 ], while the EC50 value of VAA was 34.99 µmol L-1 . Furthermore, 21 novel VAFAEs showed higher inhibitory activity against S. sclerotiorum. Validoxylamine A oleic acid ester, compound 21, exhibited the highest insecticidal activity against A. craccivora [median lethal concentration (LC50 ) 39.63 µmol L-1 ], while the LC50 value of Pymetrozine was 50.45 µmol L-1 , a commercialized pesticide against A. craccivora. CONCLUSION: Combining our results, esterification of VAA by introducing different acyl donors was beneficial for the development of new eco-friendly drugs in the field of pesticides.

Invisible Gateway by Superscattering Effect of Metamaterials.

Illusion devices, such as superscatterer and invisible gateway, have been theoretically studied under the theory of transformation optics and folded geometry transformations. The realization of these devices needs building blocks of metamaterials with negative permittivities and permeabilities. However, superscattering effects, such as stopping wave propagation in an air channel, have not been verified from illusion devices physically because of the challenge of metamaterial design, fabrication, and material loss. In this Letter, we implement a big metamaterial superscatterer, and experimentally demonstrate its superscattering effect at microwave frequencies by field-mapping technology. We confirm that superscattering is originated from the excitation of surface plasmons. Integrated with superscatterer, we experimentally display that an invisible gateway could stop electromagnetic waves in an air channel with a width much larger than the cutoff width of the corresponding rectangular waveguide. Our results provide a first direct observation of superscattering effect of double negative metamaterials and invisible gateway for electromagnetic waves. It builds up an ideal platform for future designs of other illusion devices.

[Application of sucrose phosphorylase in glycosylation].

Water solubility, stability, and bioavailability, can be substantially improved after glycosylation. Glycosylation of bioactive compounds catalyzed by glycoside hydrolases (GHs) and glycosyltransferases (GTs) has become a research hotspot. Thanks to their rich sources and use of cheap glycosyl donors, GHs are advantageous in terms of scaled catalysis compared to GTs. Among GHs, sucrose phosphorylase has attracted extensive attentions in chemical engineering due to its prominent glycosylation activity as well as its acceptor promiscuity. This paper reviews the structure, catalytic characteristics, and directional redesign of sucrose phosphorylase. Meanwhile, glycosylation of diverse chemicals with sucrose phosphorylase and its coupling applications with other biocatalysts are summarized. Future research directions were also discussed based on the current research progress combined with our working experience.

Tussilagone inhibits allergic responses in OVA-induced allergic rhinitis guinea pigs and IgE-stimulated RBL-2H3 cells.

Farfarae Flos is the dried flower buds of Tussilago farfara L. which is widely used to treat allergic and inflammatory diseases in Chinese folk. Tussilagone (TSL), a sesquiterpene compound purified from Farfarae Flos, has been confirmed the main active component in the plant. However, its anti-allergic activity hasn't been reported yet. The purpose of this study is to investigate the anti-allergic effect of TSL in ovalbumin (OVA)-induced allergic rhinitis (AR) guinea pigs and immunoglobulin E (IgE)-stimulated RBL-2H3 cells. The AR symptoms such as nasal scratching, sneezing and runny nose were scored and the histological changes of nasal mucosa were observed by H&E staining. The levels of histamine, OVA-specific IgE, IL-6 and TNF-α in the serum were measured by ELISA. In IgE-stimulated RBL-2H3 cells, the phosphoryration of Lyn, Syk, Akt, NF-κB p65, ERK and p38 MAPK were investigated by western blot analysis. The results showed that intraperitoneal injection of TSL at doses of 25 and 50 mg/kg significantly alleviated the allergic symptoms and the histological changes of nasal mucosa in OVA-induced allergic rhinitis guinea pigs. Moreover, the levels of histamine, IgE and IL-6 in the serum decreased significantly (p < .05). In vitro, TSL suppressed the phosphorylation of Lyn, Syk, Akt, NF-κB p65, ERK and p38 MAPK in IgE-stimulated RBL-2H3 cells. These results indicate TSL has therapeutic effect on allergic rhinitis in guinea pigs. The anti-allergic mechanism may be through the inhibition of allergic and inflammatory related pathways in mast cells.

Coupling of bio-PRB and enclosed in-well aeration system for remediation of nitrobenzene and aniline in groundwater.

A laboratory-scale bio-permeable reactive barrier (bio-PRB) was constructed and combined with enclosed in-well aeration system to treat nitrobenzene (NB) and aniline (AN) in groundwater. Batch-style experiments were first conducted to evaluate the effectiveness of NB and AN degradation, using suspension (free cells) of degrading consortium and immobilized consortium by a mixture of perlite and peat. The NB and AN were completely degraded in <3 days using immobilized consortium, while 3-5 days were required using free cells. The O2 supply efficiency of an enclosed in-well aeration system was assessed in a box filled with perlite and peat. Dissolved O2 (DO) concentrations increased to 8-12 mg L(-1) in 12 h for sampling ports within 12 cm of the aeration well. A diffusion coefficient as 33.5 cm(2) s(-1) was obtained. The DO concentration was >4 mg L(-1) when the aeration system was applied into the bio-PRB system. The NB and AN were effectively removed when the aeration system was functional in the bio-PRB. The removal efficiency decreased when the aeration system malfunctioned for 20 days, thus indicating that DO was an important factor for the degradation of NB and AN. The regain of NB and AN removal after the malfunction indicates the robustness of degradation consortium. No original organics and new formed by-products were observed in the effluent. The results indicate that NB and AN in groundwater can be completely mineralized in a bio-PRB equipped with enclosed in-well aeration system and filled with perlite and peat attached with degrading consortium.

Effects of extremely low frequency magnetic field on anxiety level and spatial memory of adult rats.

BACKGROUND: As the widespread use of electric devices in modern life, human are exposed to extremely low frequency magnetic fields (ELF MF) much more frequently than ever. Over the past decades, a substantial number of epidemiological and experimental studies have demonstrated that ELF MF (50 Hz) exposure is associated with increased risk of various health effects. The present study examined the effects of chronic exposure to ELF MF on anxiety level and spatial memory of adult rats. METHODS: The 50-Hz ELF MF was used during the whole experimental procedures and the value of magnetic field (MF) was set to 2 mT. Adult rats were divided randomly to control, MF 1 hour and MF 4 hours group. Anxiety-related behaviors were examined in the open field test and the elevated plus maze; changes in spatial learning and memory were determined in Morris water maze after 4 weeks of daily exposure. RESULTS: Rats in MF 4 hours group had increased anxiety-like behaviors with unaltered locomotor activity. In the Morris water maze test, rats had reduced latency to find the hidden platform and improved long-term memory of former location of platform without changes in short-term memory and locomotor activity. CONCLUSION: Chronic ELF MF exposure has anxiogenic effect on rats, and the promoting effects on spatial learning and long-term retention of spatial memory.

[A field study on the work load and muscle fatigue at neck-shoulder in female sewing machine operators by using surface electromyography].

OBJECTIVE: To study neck and shoulder work-related muscle fatigue of female sewing machine operators. METHODS: 18 health female sewing machine operators without musculoskeletal disorders work in Beijing garment industry factory as volunteers in participate of this study. The maximal voluntary contraction (MVC) and 20% MVC of bilateral upper trapezium and cervical erectors spinae was tested before sewing operations, then the whole 20 time windows (1 time window = 10 min) sewing machine operations was monitored and the surface electromyography (sEMG) signals simultaneously was recorded after monitoring the 20%MVC was tested. Use amplitude analysis method to reduction recorded EMG signals. RESULTS: During work, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezium (LUT) and right upper trapezium (RUT) respectively was 6.78 ± 1.05, 6.94 ± 1.12, 5.68 ± 2.56 and 6.47 ± 3.22, work load of right is higher than the left; static load analysis indicated the value of RMS(20%MVC) before work was higher than that value after work, the increase of right CES and UT RMS(20%MVC) was more; the largest 20%MVE of bilateral CES occurred at 20th time window, and that of bilateral UT happened at 16th. CONCLUSIONS: The work load of female sewing machine operators is sustained "static" load, and work load of right neck-shoulder is higher than left, right neck-shoulder muscle is more fatigable and much serious once fatigued.

Quantify work load and muscle functional activation patterns in neck-shoulder muscles of female sewing machine operators using surface electromyogram.

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) have high prevalence in sewing machine operators employed in the garment industry. Long work duration, sustained low level work and precise hand work are the main risk factors of neck-shoulder disorders for sewing machine operators. Surface electromyogram (sEMG) offers a valuable tool to determine muscle activity (internal exposure) and quantify muscular load (external exposure). During sustained and/or repetitive muscle contractions, typical changes of muscle fatigue in sEMG, as an increase in amplitude or a decrease as a shift in spectrum towards lower frequencies, can be observed. In this paper, we measured and quantified the muscle load and muscular activity patterns of neck-shoulder muscles in female sewing machine operators during sustained sewing machine operating tasks using sEMG. METHODS: A total of 18 healthy women sewing machine operators volunteered to participate in this study. Before their daily sewing machine operating task, we measured the maximal voluntary contractions (MVC) and 20%MVC of bilateral cervical erector spinae (CES) and upper trapezius (UT) respectively, then the sEMG signals of bilateral UT and CES were monitored and recorded continuously during 200 minutes of sustained sewing machine operating simultaneously which equals to 20 time windows with 10 minutes as one time window. After 200 minutes' work, we retest 20%MVC of four neck-shoulder muscles and recorded the sEMG signals. Linear analysis, including amplitude probability distribution frequency (APDF), amplitude analysis parameters such as roof mean square (RMS) and spectrum analysis parameter as median frequency (MF), were used to calculate and indicate muscle load and muscular activity of bilateral CES and UT. RESULTS: During 200 minutes of sewing machine operating, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezius (LUT) and right upper trapezius (RUT) were 6.78%MVE, 6.94%MVE, 6.47%MVE and 5.68%MVE, respectively. Work load of right muscles are significantly higher than that of the left muscles (P < 0.05); sEMG signal analysis of isometric contractions indicated that the amplitude value before operating was significantly higher than that of after work (P < 0.01), and the spectrum value of bilateral CES and UT were significantly lower than those of after work (P < 0.01); according to the sEMG signal data of 20 time windows, with operating time pass by, the muscle activity patterns of bilateral CES and UT showed dynamic changes, the maximal amplitude of LCES, RCES, LUT occurred at the 20th time window, RUT at 16th time window, spectrum analysis showed that the lower value happened at 7th, 16th, 20th time windows. CONCLUSIONS: Female sewing machine operators were exposed to high sustained static load on bilateral neck-shoulder muscles; left neck and shoulder muscles were held in more static positions; the 7th, 16th, and 20th time windows were muscle fatigue period that ergonomics intervention can protocol at these periods.

[Effects of chronic exposure of power frequency magnetic field on neurobehavior in rats].

OBJECTIVE: To observe the effect of chronic exposure to extremely low frequency magnetic field on neurobehavioral of adult rats. METHODS: Fifty Hz sinusoidal extremely low frequency magnetic field (ELF-MF) was used in this experimental procedure and the strength of magnetic field was fixed at 2 mT. Thirty male adult rats were divided randomly into 3 groups: (1) no ELF MF exposure (control group, n=10); (2) exposure to ELF MF 1 h/day (MF1h group, n=10); (3) exposure to ELF MF 4 h/day (MF4h group, n=10). The neurobehavioral changes of rats were detected by the open field test, elevated plus maze test and light/dark box test. RESULTS: Compared with controls, no significant difference was found in rats of MF1h group in any test. Rats in MF4h group showed increased thigmotaxis, more grooming in the open field test; less time spent in open arms, central part and more time spent in closed arms. However, no significant difference was observed in the light/dark test in MF1h or MF4h group. CONCLUSION: Chronic ELF MF exposure has an anxiogenic effect on rats, which is dependent on the daily exposure duration.

[Changes of nitric oxide and nitric-oxide synthase in the development of cold-induced hypertension].

OBJECTIVE: To study the changes of nitric oxide(NO) and nitric-oxide synthase(NOS) in the development of cold-induced hypertension (CIH). METHODS: Sixty male Sprague-Dawley adult rats were used. Thirty were exposed to cold (4 +/- 1) degrees C as cold-treated group while the other 30 were at (25 +/- 1) degrees C as controls, 4 hours a day for 6 weeks for both groups. Systolic blood pressure (SBP) and heart rate were measured twice every week. Each group was further subdivided into three groups, 10 rats each. A subgroup of the cold-treated and control rats were sacrificed at 2, 4 and 6 week. Plasma was saved to measure superoxide dismutase (SOD) and malondiadehycle (MDA), while heart was homogenated to measure NO, NOS. RESULTS: 1 SBP increased during 6 weeks of exposure to cold. From the second week, SBP of cold-treated group [(94.16 +/- 3.81) mm Hg] was significantly greater than that of control group [(88.77 +/- 4.45 mm Hg), P<0.01]. The highest SBP level was achieved at the sixth week [(116.78 +/- 3.79)mm Hg, P<0.01]. 2 Compared to the control group, SOD in cold-treated group decreased significantly from the second week, and maintained throughout the time of exposure to cold (P<0.05). MDA levels did not differ significantly between cold-treated and control groups though it increased mildly during 6 weeks of cold exposure (P>0.05). Heart NOS in cold-treated group decreased significantly from the fourth week to the sixth week. And a mild decrease was observed in heart NO of cold-treated group during 6 weeks of exposure (P>0.05). CONCLUSION: Cold-induced hypertension is induced in rats after repeated exposure to cold. The levels of NOS, NO decrease accordingly to the rise of blood pressure. This indicates that the dysfunction of NO and NOS is involved in the development of CIH.