A Rare Benzothiazole Glucoside as a Derivative of 'Albedo Bluing' Substance in Citrus Fruit and Its Antioxidant Activity.

'Albedo bluing' of fruits occurs in many varieties of citrus, resulting in a significant reduction in their commercial value. We first presented a breakthrough method for successfully extracting and purifying the 'albedo bluing' substance (ABS) from citrus fruits, resulting in the attainment of highly purified ABS. Then, HPLC and UPLC-QTOF-MS were used to prove that ABS in the fruits of three citrus varieties (Citrus reticulate Blanco cv. 'Gonggan', 'Orah', and 'Mashuiju') are identical. However, the chemical structure of ABS remains elusive for many reasons. Fortunately, a more stable derivative of ABS (ABS-D) was successfully obtained. Through various analytical techniques such as HRESIMS, 1D and 2D NMR, and chemical shift calculation, ABS-D was identified as 2,4-dihydroxy-6-(ß-D-glucopyranosyloxy)phenyl(5,6-dihydroxy-7-(ß-D-glucopyranosyloxy)benzo[d]thiazol-2-yl)methanone, indicating that both ABS and its derivative belong to a rare category of benzothiazole glucosides. Furthermore, both ABS and ABS-D demonstrated potent antioxidant abilities. These findings lay the groundwork for further elucidating the chemical structure of ABS and the causative mechanism of the 'albedo bluing' phenomenon in citrus fruits.

Light-Assisted CO2 Hydrogenation over Pd3 Cu@UiO-66 Promoted by Active Sites in Close Proximity.

CO2 hydrogenation to methanol has attracted great interest while suffering from low conversion and high energy input. Herein, tiny Pd3 Cu nanoparticles are confined into a metal-organic framework (MOF), UiO-66, to afford Pd3 Cu@UiO-66 for CO2 hydrogenation. Remarkably, it achieves a methanol production rate of 340 µmol g-1 h-1 at 200 °C and 1.25 MPa under light irradiation, far surpassing that in the dark. The photo-generated electron transfer from the MOF to antibonding orbitals of CO2 * promotes CO2 activation and HCOO* formation. In addition, the Pd3 Cu microenvironment plays a critical role in CO2 hydrogenation. In contrast to the MOF-supported Pd3 Cu (Pd3 Cu/UiO-66), the Pd3 Cu@UiO-66 exhibits a much higher methanol production rate due to the close proximity between CO2 and H2 activation sites, which greatly facilitates their interaction and conversion. This work provides a new avenue to the integration of solar and thermal energy for efficient CO2 hydrogenation under moderate conditions.

Comprehensive Analysis of Autophagy-Related Genes in Sweet Orange (Citrus sinensis) Highlights Their Roles in Response to Abiotic Stresses.

Autophagy is a highly conserved intracellular degradation pathway that breaks down damaged macromolecules and/or organelles. It is involved in plant development and senescence, as well as in biotic and abiotic stresses. However, the autophagy process and related genes are largely unknown in citrus. In this study, we identified 35 autophagy-related genes (CsATGs-autophagy-related genes (ATGs) of Citrus sinensis, Cs) in a genome-wide manner from sweet orange (Citrus sinensis). Bioinformatic analysis showed that these CsATGs were highly similar to Arabidopsis ATGs in both sequence and phylogeny. All the CsATGs were randomly distributed on nine known (28 genes) and one unknown (7 genes) chromosomes. Ten CsATGs were predicted to be segmental duplications. Expression patterns suggested that most of the CsATG were significantly up- or down-regulated in response to drought; cold; heat; salt; mannitol; and excess manganese, copper, and cadmium stresses. In addition, two ATG18 members, CsATG18a and CsATG18b, were cloned from sweet orange and ectopically expressed in Arabidopsis. The CsATG18a and CsATG18b transgenic plants showed enhanced tolerance to osmotic stress, salt, as well as drought (CsATG18a) or cold (CsATG18b), compared to wild-type plants. These results highlight the essential roles of CsATG genes in abiotic stresses.

Whole-transcriptome RNA sequencing reveals the global molecular responses and ceRNA regulatory network of mRNAs, lncRNAs, miRNAs and circRNAs in response to copper toxicity in Ziyang Xiangcheng (Citrus junos Sieb. Ex Tanaka).

BACKGROUND: Copper (Cu) toxicity has become a potential threat for citrus production, but little is known about related mechanisms. This study aims to uncover the global landscape of mRNAs, long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) in response to Cu toxicity so as to construct a regulatory network of competing endogenous RNAs (ceRNAs) and to provide valuable knowledge pertinent to Cu response in citrus. RESULTS: Tolerance of four commonly used rootstocks to Cu toxicity was evaluated, and 'Ziyang Xiangcheng' (Citrus junos) was found to be the most tolerant genotype. Then the roots and leaves sampled from 'Ziyang Xiangcheng' with or without Cu treatment were used for whole-transcriptome sequencing. In total, 5734 and 222 mRNAs, 164 and 5 lncRNAs, 45 and 17 circRNAs, and 147 and 130 miRNAs were identified to be differentially expressed (DE) in Cu-treated roots and leaves, respectively, in comparison with the control. Gene ontology enrichment analysis showed that most of the DEmRNAs and targets of DElncRNAs and DEmiRNAs were annotated to the categories of 'oxidation-reduction', 'phosphorylation', 'membrane', and 'ion binding'. The ceRNA network was then constructed with the predicted pairs of DEmRNAs-DEmiRNAs and DElncRNAs-DEmiRNAs, which further revealed regulatory roles of these DERNAs in Cu toxicity. CONCLUSIONS: A large number of mRNAs, lncRNAs, circRNAs, and miRNAs in 'Ziyang Xiangcheng' were altered in response to Cu toxicity, which may play crucial roles in mitigation of Cu toxicity through the ceRNA regulatory network in this Cu-tolerant rootstock.

Enhanced Photocatalytic Degradation Performance by Fluid-Induced Piezoelectric Field.

The introduction of a piezoelectric field has been proven a promising method to enhance photocatalytic activity by preventing photoelectron-hole recombination. However, the formation of a piezoelectric field requires additional mechanical force or high-frequency ultrasonic baths, which limits its potential application on industrial scale. Therefore, it is of great practical significance to design the catalyst that can harvest the discrete energy such as the fluid mechanical energy to form the electric field. Herein, PZT/TiO2 catalyst with a core-shell configuration was prepared by a simple coating method. By collecting the mechanical energy of water, an internal piezoelectric field was induced. Under 800 rpm stirring, transient photocurrent measured on PZT/TiO2 electrode is about 1.7 times higher than that of 400 rpm. Correspondingly, the photocatalytic degradation rate and mineralization efficiency of RhB, BPA, phenol, p-chlorophenol much improved, showing the promoting effect of piezoelectric field generated directly from harvesting the discrete fluid mechanical energy.

Magnesium Oxide Embedded Nitrogen Self-Doped Biochar Composites: Fast and High-Efficiency Adsorption of Heavy Metals in an Aqueous Solution.

Lead (Pb) pollution in natural water bodies is an environmental concern due to toxic effects on aquatic ecosystems and human health, while adsorption is an effective approach to remove Pb from the water. Surface interactions between adsorbents and adsorbates play a dominant role in the adsorption process, and properly engineering a material's surface property is critical to the improvement of adsorption performance. In this study, the magnesium oxide (MgO) nanoparticles stabilized on the N-doped biochar (MgO@N-biochar) were synthesized by one-pot fast pyrolysis of an MgCl2-loaded N-enriched hydrophyte biomass as a way to increase the exchangeable ions and N-containing functional groups and facilitate the adsorption of Pb2+. The as-synthesized MgO@N-biochar has a high performance with Pb in an aqueous solution with a large adsorption capacity (893 mg/g), a very short equilibrium time (<10 min), and a large throughput (∼4450 BV). Results show that this excellent adsorption performance can be maintained with various environmentally relevant interferences including pH, natural organic matter, and other metal ions, suggesting that the material may be suitable for the treatment of wastewater, natural bodies of water, and even drinking water. In addition, MgO@N-biochar quickly and efficiently removed Cd2+ and tetracycline. Multiple characterizations and comparative tests have been performed to demonstrate the surface adsorption and ion exchange contributed to partial Pb adsorption, and it can be inferred from these results that the high performance of MgO@N-biochar is mainly due to the surface coordination of Pb2+ and C═O or O═C-O, pyridinic, pyridonic, and pyrrolic N. This work suggests that engineering surface functional groups of biochar may be crucial for the development of high performance heavy metal adsorbents.

Exogenous spermine pretreatment confers tolerance to combined high-temperature and drought stress in vitro in trifoliate orange seedlings via modulation of antioxidative capacity and expression of stress-related genes.

Spermine (Spm) is thought to play an important role in drought or high-temperature (HT) tolerance. However, it is not clear whether Spm confers similar resistance in the presence of both drought and HT, which often occur simultaneously. In the present study, the trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings were pretreated with 1 mmol L-1 Spm to evaluate their tolerance to combined drought and HT (45 ºC) stress. Spm-pretreated seedlings showed less leaf wilting, less water loss and less electrolyte leakage than control leaves not treated with Spm within 180 min of treatment. Histochemical staining with diaminobenzidine and nitro blue tetrazolium showed that Spm-pretreated seedlings accumulated less hydrogen peroxide and superoxide than those of control plants 60, 120 and 180 min after treatment when exposed to both drought and HT (45 ºC). However, superoxide dismutase, peroxidase and catalase were significantly more active in Spm-pretreated seedlings than in control seedlings. In addition, Spm-pretreated seedlings showed significantly higher expression of heat shock proteins, abscisic acid (ABA)-responsive element binding factor and 9-cis-epoxycarotenoid dioxygenase 3 than controls either before (0 min) or after (60, 120 and 180 min) combined drought and HT treatment. All of these data suggest that exogenous Spm pretreatment confers tolerance to simultaneously occurring drought and HT stresses. Spm may influence this by activating antioxidant enzymes, increasing the effectiveness of scavenging of reactive oxygen species. It may also increase the expression levels of stress-related genes that protect trifoliate orange seedlings from stress damage.

Promoted hydrogenation of CO2 to methanol over single-atom Cu sites with Na+-decorated microenvironment.

Although single-atom Cu sites exhibit high efficiency in CO2 hydrogenation to methanol, they are prone to forming Cu nanoparticles due to reduction and aggregation under reaction conditions, especially at high temperatures. Herein, single-atom Cu sites stabilized by adjacent Na+ ions have been successfully constructed within a metal-organic framework (MOF)-based catalyst, namely MOF-808-NaCu. It is found that the electrostatic interaction between the Na+ and Hδ- species plays a pivotal role in upholding the atomic dispersion of Cu in MOF-808-NaCu during CO2 hydrogenation, even at temperatures of up to 275°C. This exceptional stabilization effect endows the catalyst with excellent activity (306 g·kgcat-1·h-1), high selectivity to methanol (93%) and long-term stability at elevated reaction temperatures, far surpassing the counterpart in the absence of Na+ (denoted as MOF-808-Cu). This work develops an effective strategy for the fabrication of stable single-atom sites for advanced catalysis by creating an alkali-decorated microenvironment in close proximity.

[Identification of CjSPL gene family in Ziyang Xiangcheng rootstock and expression pattern analysis].

Squamosa promoter binding protein-like (SPL) family is a group of important transcription factors involved in the regulation of plant growth and development and the response to environmental stress, but there are few studies in perennial fruit trees such as citrus. In this study, Ziyang Xiangcheng (Citrus junos Sib.ex Tanaka), an important rootstock of Citrus, was used as the material for analysis. Based on plantTFDB transcription factor database and sweet orange genome database, 15 SPL family members were genome-widely identified and cloned from Ziyang Xiangcheng, and named CjSPL1-CjSPL15. Sequence analysis showed that the open reading frame (ORF) length of CjSPLs ranged from 393 bp to 2 865 bp, encoding 130-954 amino acids. Phylogenetic tree divided 15 CjSPLs into 9 subfamilies. Gene structure and conserved domain analysis predicted 20 different conserved motifs and SBP basic domains. Analysis of cis-acting promoter elements predicted 20 different promoter elements, including those related to plant growth and development, abiotic stress and secondary metabolites. The expression patterns of CjSPLs under drought, salt and low temperature stresses were analyzed by real-time fluorescence quantitative PCR (qRT-PCR), and many CjSPLs were significantly up-regulated after stress treatment. This study provides a reference for further study on the function of SPL family transcription factors in citrus and other fruit trees.

Potassium-Assisted Fabrication of Intrinsic Defects in Porous Carbons for Electrocatalytic CO2 Reduction.

The fabrication of intrinsic carbon defects is usually tangled with doping effects, and the identification of their unique roles in catalysis remains a tough task. Herein, a K+ -assisted synthetic strategy is developed to afford porous carbon (K-defect-C) with abundant intrinsic defects and complete elimination of heteroatom via direct pyrolysis of K+ -confined metal-organic frameworks (MOFs). Positron-annihilation lifetime spectroscopy, X-ray absorption fine structure measurement, and scanning transmission electron microscopy jointly illustrate the existence of abundant 12-vacancy-type carbon defects (V12 ) in K-defect-C. Remarkably, the K-defect-C achieves ultrahigh CO Faradaic efficiency (99%) at -0.45 V in CO2 electroreduction, far surpassing MOF-derived carbon without K+ etching. Theoretical calculations reveal that the V12 defects in K-defect-C favor CO2 adsorption and significantly accelerate the formation of the rate-determining COOH* intermediate, thereby promoting CO2 reduction. This work develops a novel strategy to generate intrinsic carbon defects and provides new insights into their critical role in catalysis.

Effect of the Rare Earth Element Lanthanum (La) on the Growth and Development of Citrus Rootstock Seedlings.

Rare earth elements (REEs) can affect the growth and development of plants. However, few studies have been carried out on the effects of REEs on citrus seedlings. In this study, the growth parameters, toxicity symptoms, chlorophyll content, and La content of three citrus rootstocks are analyzed under different concentrations of La, a representative REE. The results show that the growth of citrus rootstock seedlings was stimulated at La ≤ 0.5 mmol·L-1 and inhibited at concentrations above 1 mmol·L-1. The chlorophyll and carotenoid contents of trifoliate orange (Poncirus trifoliata L. Raf.) and Ziyang Xiangcheng (C. junos Sieb. ex Tanaka) leaves of plants grown at low concentrations of La (≤1.5 mmol·L-1) were similar to those of the control but were significantly reduced at 4 mmol·L-1 La. Toxic symptoms gradually appeared with increasing La concentrations, with yellowed leaves and burst veins appearing at 4 mmol·L-1 La. The symptoms of toxicity were most severe in trifoliate orange, followed by Shatian Pomelo (Citrus grandis var. shatinyu Hort) and then Ziyang Xiangcheng. Moreover, in leaves, the Ca content was significantly negatively correlated with La content (p < 0.01). These results indicate that La has a hormesis effect on the growth of citrus rootstocks. Of the studied citrus seedlings, Ziyang Xiangcheng is the most resistant to La.

Hydrogenation of Furfural to Cyclopentanone under Mild Conditions by a Structure-Optimized Ni-NiO/TiO2 Heterojunction Catalyst.

The catalytic conversion of biomass-derived furfural (FFA) into cyclopentanone (CPO) in aqueous solution is an important pathway to obtain sustainable resources. However, the conversion and selectivity under mild conditions are still unsatisfactory. In this study, a catalyst consisting of Ni-NiO heterojunction supported on TiO2 with optimized composition of anatase and rutile (Ni-NiO/TiO2 -Re450) is prepared by pyrolysis at 450 °C. With Ni-NiO/TiO2 -Re450, as catalyst, complete conversion of FFA and 87.4 % yield of CPO are achieved under mild reaction conditions (1 MPa, 140 °C, 6 h). 95.4 % FFA conversion is retained up to the fifth run, indicating the high stability of the catalyst. Multiple characterizations, control experiments, and theoretical calculations demonstrate that the good catalytic performance of Ni-NiO/TiO2 -Re450 can be attributed to a synergistic effect of the Ni-NiO heterojunction and the TiO2 support. This low-cost catalyst may expedite the catalytic upgrading and practical application of biomass-derived chemicals.

Self-Powered Electrostatic Filter with Enhanced Photocatalytic Degradation of Formaldehyde Based on Built-in Triboelectric Nanogenerators.

Recently, atmospheric pollution caused by particulate matter or volatile organic compounds (VOCs) has become a serious issue to threaten human health. Consequently, it is highly desirable to develop an efficient purifying technique with simple structure and low cost. In this study, by combining a triboelectric nanogenerator (TENG) and a photocatalysis technique, we demonstrated a concept of a self-powered filtering method for removing pollutants from indoor atmosphere. The photocatalyst P25 or Pt/P25 was embedded on the surface of polymer-coated stainless steel wires, and such steel wires were woven into a filtering network. A strong electric field can be induced on this filtering network by TENG, while both electrostatic adsorption effect and TENG-enhanced photocatalytic effect can be achieved. Rhodamine B (RhB) steam was selected as the pollutant for demonstration. The absorbed RhB on the filter network with TENG in 1 min was almost the same amount of absorption achieved in 15 min without using TENG. Meanwhile, the degradation of RhB was increased over 50% under the drive of TENG. Furthermore, such a device was applied for the degradation of formaldehyde, where degradation efficiency was doubled under the drive of TENG. This work extended the application for the TENG in self-powered electrochemistry, design and concept of which can be possibly applied in the field of haze governance, indoor air cleaning, and photocatalytic pollution removal for environmental protection.

Improving "color rendering" of LED lighting for the growth of lettuce.

Light plays a vital role on the growth and development of plant. On the base of white light with high color rendering to the benefit of human survival and life, we proposed to improve "color rendering" of LED lighting for accelerating the growth of lettuce. Seven spectral LED lights were adopted to irradiate the lettuces under 150 µmol·m-2·s-1 for a 16 hd-1 photoperiod. The leaf area and number profiles, plant biomass, and photosynthetic rate under the as-prepared LED light treatments were investigated. We let the absorption spectrum of fresh leaf be the emission spectrum of ideal light and then evaluate the "color rendering" of as-prepared LED lights by the Pearson product-moment correlation coefficient and CIE chromaticity coordinates. Under the irradiation of red-yellow-blue light with high correlation coefficient of 0.587, the dry weights and leaf growth rate are 2-3 times as high as the sharp red-blue light. The optimized LED light for lettuce growth can be presumed to be limited to the angle (about 75°) between the vectors passed through the ideal light in the CIE chromaticity coordinates. These findings open up a new idea to assess and find the optimized LED light for plant growth.

Genome-Wide Identification, Cloning and Functional Analysis of the Zinc/Iron-Regulated Transporter-Like Protein (ZIP) Gene Family in Trifoliate Orange (Poncirus trifoliata L. Raf.).

Zinc (Zn) and iron (Fe) deficiency are widespread among citrus plants, but the molecular mechanisms regarding uptake and transport of these two essential metal ions in citrus are still unclear. In the present study, 12 members of the Zn/Fe-regulated transporter (ZRT/IRT)-related protein (ZIP) gene family were identified and isolated from a widely used citrus rootstock, trifoliate orange (Poncirus trifoliata L. Raf.), and the genes were correspondingly named as PtZIPs according to the sequence and functional similarity to Arabidopsis thaliana ZIPs. The 12 PtZIP genes were predicted to encode proteins of 334-419 amino acids, harboring 6-9 putative transmembrane (TM) domains. All of the PtZIP proteins contained the highly conserved ZIP signature sequences in TM-IV, and nine of them showed a variable region rich in histidine residues between TM-III and TM-IV. Phylogenetic analysis subdivided the PtZIPs into four groups, similar as found for the ZIP family of A. thaliana, with clustered PtZIPs sharing a similar gene structure. Expression analysis showed that the PtZIP genes were very differently induced in roots and leaves under conditions of Zn, Fe and Mn deficiency. Yeast complementation tests indicated that PtIRT1, PtZIP1, PtZIP2, PtZIP3, and PtZIP12 were able to complement the zrt1zrt2 mutant, which was deficient in Zn uptake; PtIRT1 and PtZIP7 were able to complement the fet3fet4 mutant, which was deficient in Fe uptake, and PtIRT1 was able to complement the smf1 mutant, which was deficient in Mn uptake, suggesting their respective functions in Zn, Fe, and Mn transport. The present study broadens our understanding of metal ion uptake and transport and functional divergence of the various PtZIP genes in citrus plants.

Efficacy and safety of Xinglouchengqi decoction for acute ischemic stroke with constipation: study protocol for a randomized controlled trial.

OBJECTIVE: To investigate the efficacy and safety of Xinglouchengqi (XLCQ) decoction in treatment of acute ischemic stroke with constipation. METHODS: In this prospective, multicenter, assessor-blinded, randomized controlled trial, 360 eligible participants will be randomized to the XLCQ group or the control group. Participants in the XLCQ group will receive XLCQ decoction, while those in the control group will undergo clysis therapy using glycerin enemas or oral administration of lactulose solution. Both groups will undergo a treatment period of (5 ± 2) d and a 1-month follow-up. The primary outcome measure will be the Constipation Scale score. The secondary outcome measures will include scores on the National Institutes of Health Stroke Scale, the Traditional Chinese Medicine (TCM) Stroke Scale, the Diagnostic Scale for TCM Syndromes of Ischemic Stroke and TCM Scale for Syndrome of Phlegm-heat and Fu-organ Excess. Therapeutic mechanism outcomes and safety outcomes will also be assessed. Assessments will be conducted at baseline, at the end of the treatment period, and at the follow-up. Moreover, daily visits will be scheduled to grade the status of constipation during the treatment period. DISCUSSION: The results of this study will provide scientific and objective data with which to assess the efficacy and safety of XLCQ decoction for patients with acute ischemic stroke and constipation.

Genome-wide identification of sweet orange (Citrus sinensis) metal tolerance proteins and analysis of their expression patterns under zinc, manganese, copper, and cadmium toxicity.

Plant metal tolerance proteins (MTPs) play important roles in heavy metal homeostasis; however, related information in citrus plants is limited. Citrus genome sequencing and assembly have enabled us to perform a systematic analysis of the MTP gene family. We identified 12 MTP genes in sweet orange, which we have named as CitMTP1 and CitMTP3 to CitMTP12 based on their sequence similarity to Arabidopsis thaliana MTPs. The CitMTPs were predicted to encode proteins of 864 to 2556 amino acids in length that included 4 to 6 putative transmembrane domains (TMDs). Furthermore, all the CitMTPs contained a highly conserved signature sequence encompassing the TMD-II and the start of the TMD-III. Phylogenetic analysis further classified the CitMTPs into Fe/Zn-MTP, Mn-MTP, and Zn-MTP subgroups, which coincided with the MTPs of A. thaliana and rice. The closely clustered CitMTPs shared a similar gene structure. Expression analysis indicated that most CitMTP transcripts were upregulated to various extents under heavy metal stress. Among these, CitMTP5 in the roots and CitMTP11 in the leaves during Zn stress, CitMTP8 in the roots and CitMTP8.1 in the leaves during Mn stress, CitMTP12 in the roots and CitMTP1 in the leaves during Cu stress, and CitMTP11 in the roots and CitMTP1 in the leaves during Cd stress showed the highest extent of upregulation. These findings are suggestive of their individual roles in heavy metal detoxification.

[Citrus boron nutrient level and its impact factors in the Three Gorges Reservoir region of Chongqing, China].

To investigate the level of boron nutrient in citrus and its impact factors, a total of 954 citrus leaf samples and 302 soil samples were collected from representative orchards in the 12 main citrus production counties in the Three Gorges Reservoir region of Chongqing to determine the boron content in citrus leaves, as well as the relationships between leaf boron content with soil available boron content, soil pH value, cultivar, rootstock and the age of tree. Results indicated that the leaf samples from 41.6% orchards (< 35 mg x kg(-1)) and the soil samples from 89.4% orchards (< 0.5 mg x kg(-1)) were boron insufficient. The correlation of leaf boron content and soil available boron content was not significant. The soil pH, cultivar, rootstock and the age of tree did affect the leaf boron content. The leaves from the orchards with soil pH of 4.5-6.4 demonstrated significantly higher boron contents than with the soil pH of 6.5-8.5. The leaf boron contents in the different cultivars was ranged as Satsuma mandarin > pomelo > valencia orange > sweet orange > tangor > navel orange. The citrus on trifoliate orange and sour pomelo rootstocks had significantly higher leaf boron contents than on Carrizo citrange and red tangerine rootstocks. Compared with the adult citrus trees (above 8 year-old), 6.6% more of leaf samples of younger trees (3 to 8 year-old) contained boron contents in the optimum range (35-100 mg x kg(-1)).

[Prevalence and risk factors of prehypertensive status in people from the rural area of Lanxi county, Heilongjiang province].

OBJECTIVE: To access the prevalence of prehypertensive stage and its associated risk factors in rural inhabitants from Lanxi county in Heilongjiang province. METHODS: Through cluster multistage and random sampling methods, local people aged > or = 15 years old in Lanxi county were selected. A survey on blood pressure and associated risk factors was carried out. Overnight fasting blood specimen of people aged > or = 35 years old was collected. Chi-square test, t-test and logistic regression analyses were then performed. RESULTS: 5272 residents were surveyed including 2539 male and 2733 female subjects. The overall prevalence of prehypertension was 36.34%. The prevalence of prehypertension appeared to be higher in males (39.50%) than in females (33.41%) (chi2 = 58.9887, P < 0.0001). The prevalence of prehypertension decreased with increasing age in men > or = 25 years old (chi2 = 96.0698, P < 0.0001), and in women > or = 35 years old (chi2 = 11.5784, P = 0.0208). Data from multivariable logistic regression showed that being male, aged (> or = 55 years old), with waist circumference as > or = 85 cm for men and > or = 80 cm for women, BMI > or = 25.0 kg/m2 and fasting plasma glucose > or = 7.0 mmol/L were risk factors of prehypertension while high-density lipoprotein cholesterol < 0.9 mmol/L was shown as a protective factor (OR = 0.740, P = 0.0036). Dose-response relationships were seen between prehypertension and age, BMI and FPG. CONCLUSION: Prehypertension was popular in the rural area, with high prevalence seen in teenagers. Programs on prehypertension prevention should start from teenagers. Risk factors of prehypertension increased when people became age 55 or older. There was a need to monitor BP more often and to control BP through non-drug methods.