Empowering pro-environmental behavior in tourists through digital media: the influence of eco-guilt and empathy with nature.

In the digital economy era, leveraging digital media to foster tourists' pro-environmental behavioral intention (TPEBI) has become crucial in the field of sustainable tourism. While existing studies have mainly focused on the driving mechanism of TPEBI within physical tourism contexts, the correlation between digital media information sharing and TPEBI remains unclear. Our study employs the cognitive-affective-conative framework to construct a theoretical model, considering eco-guilt and empathy with nature as mediating variables. It aims to explore the influencing mechanism of destination environmental information sharing through digital media on TPEBI from a presence perspective. Thereby, two scenario experiments were designed: Study 1 examined the impact of different formats of destination environmental threat information presentation on digital media on the sense of presence, while Study 2 explored the influencing mechanism of presence on TPEBI based on the conclusions of Study 1. Results indicate that (1) vivid and visible presentation formats of destination environmental threat information on digital media enhance individuals' sense of presence; (2) sense of presence positively influences TPEBI; and (3) eco-guilt and empathy with nature mediate between presence and TPEBI. These findings not only contribute to theoretical and empirical research on digital media information sharing in sustainable tourism but also offer guidance for governments and tourism destinations to effectively stimulate TPEBI through digital media, achieve the sustainable development of destinations.

Developing an AI-assisted digital auscultation tool for automatic assessment of the severity of mitral regurgitation: protocol for a cross-sectional, non-interventional study.

INTRODUCTION: Mitral regurgitation (MR) is the most common valvular heart disorder, with a morbidity rate of 2.5%. While echocardiography is commonly used in assessing MR, it has many limitations, especially for large-scale MR screening. Cardiac auscultation with electronic stethoscope and artificial intelligence (AI) can be a fast and economical modality for assessing MR severity. Our objectives are (1) to establish a deep neural network (DNN)-based cardiac auscultation method for assessing the severity of MR; and (2) to quantitatively measure the performance of the developed AI-based MR assessment method by virtual clinical trial. METHODS AND ANALYSIS: In a cross-sectional design, phonocardiogram will be recorded at the mitral valve auscultation area of outpatients. The enrolled patients will be checked by echocardiography to confirm the diagnosis of MR or no MR. Echocardiographic parameters will be used as gold standard to assess the severity of MR, classified into four levels: none, mild, moderate and severe. The study consists of two stages. First, an MR-related cardiac sound database will be created on which a DNN-based MR severity classifier will be trained. The automatic MR severity classifier will be integrated with the Smartho-D2 electronic stethoscope. Second, the performance of the developed smart device will be assessed in an independent clinical validation data set. Sensitivity, specificity, precision, accuracy and F1 score of the developed smart MR assessment device will be evaluated. Agreement on the performance of the smart device between cardiologist users and patient users will be inspected. The interpretability of the developed model will also be studied with statistical comparisons of occlusion map-guided variables among the four severity groups. ETHICS AND DISSEMINATION: The study protocol was approved by the Medical Ethics Committee of Huzhou Central Hospital, China (registration number: 202302009-01). Informed consent is required from all participants. Dissemination will be through conference presentations and peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2300069496.

Rationale and design of a comparison of angiography-derived fractional flow reserve-guided and intravascular ultrasound-guided intervention strategy for clinical outcomes in patients with coronary artery disease: a randomised controlled trial (FLAVOUR II).

INTRODUCTION: Percutaneous coronary intervention (PCI) guided by coronary angiography-derived fractional flow reserve (FFR) or intravascular ultrasound (IVUS) has shown improved clinical outcomes compared with angiography-only-guided PCI. In patients with intermediate stenoses, FFR resulted in fewer coronary interventions and was non-inferior to IVUS with respect to clinical outcomes. However, whether this finding can be applied to angiography-derived FFR in significant coronary artery disease (CAD) remains unclear. METHOD AND ANALYSIS: The comparison of angiography-derived FFR-guided and IVUS-guided intervention strategies for clinical outcomes in patients with coronary artery disease (FLAVOUR II) trial is a multicentre, prospective, randomised controlled trial. A total of 1872 patients with angiographically significant CAD (stenoses of at least 50% as estimated visually through angiography) in a major epicardial coronary artery will be randomised 1:1 to receive either angiography-derived FFR-guided or IVUS-guided PCI. Patients will be treated with second-generation drug-eluting stent according to the predefined criteria for revascularisation: angiography-derived FFR≤0.8 and minimal lumen area (MLA)≤3 mm2 or 3 mm270%. The primary endpoint is a composite of all-cause death, myocardial infarction and revascularisation at 12 months after randomisation. We will test the non-inferiority of the angiography-derived FFR-guided strategy compared with the IVUS-guided decision for PCI and the stent optimisation strategy.The FLAVOUR II trial will provide new insights into optimal evaluation and treatment strategies for patients with CAD. ETHICS AND DISSEMINATION: FLAVOUR II was approved by the institutional review board at each participating site (The Second Affiliated Hospital of Zhejiang University School of Medicine Approval No: 2020LSYD410) and will be conducted in line with the Declaration of Helsinki. Informed consent would be obtained from each patient before their participation. The study results will be submitted to a scientific journal. TRIAL REGISTRATION NUMBER: NCT04397211.

Synthesis of Benzoselenophenes via TMSCN-Enabled Radical-Mediated Tandem Reaction Involving Enamides and Elemental Selenium.

This study presents a TMSCN-enabled tandem reaction involving enamides and elemental selenium to access a diverse array of benzoselenophenes. Notably, this methodology involves the direct 2-fold C(sp2)-H bond activation without the need for preinstalled halides or boronic acids as reaction handles. The protocol offers several noteworthy features, including the absence of transition metals and strong oxidants, high reaction efficiency, broad substrate scopes, and the use of stable elemental selenium as a selenium source.

Inactivation of SSIIIa enhances the RS content through altering starch structure and accumulating C18:2 in japonica rice.

SSIIIa was the key gene responsible for RS formation in rice endosperm. The higher RS content in ssIIIa mutant has been proposed to be majorly due to the increased amylose-lipid complexes (RS5). However, the formation of RS5 elicited by ssIIIa mutation and the importance of RS5 for total RS content in rice are still unclear. With japonica ssIIIa loss-of-function mutants created by CRISPR/Cas9 gene editing, the effects of SSIIIa mutation on RS5 were furtherly evaluated through investigating the transcriptome and metabolites. Inactivation of SSIIIa caused significant enhancement in amylose and RS content but without depletion in starch reserves. SSIIIa mutation modulated the genes involved in carbohydrate and lipid metabolisms and the redistribution of substances, led to accumulated protein, glucose, fructose, and C18:2. Besides the increased amylose content and altered amylopectin structure, the increased C18:2 contributed greatly to the enhancement in RS content in japonica ssIIIa mutants through complexing with amylose to form RS5, while the existence of lipid counted against the enhancement of RS content in indica rice. RS5 showed discrepant contributions for the total RS in rice with different genetic background. Inactivation of SSIIIa has great potential in improving RS5 content in japonica rice without great yield loss.

Effect of implantable cardioverter defibrillator on primary prevention of sudden cardiac death in high-risk patients.

OBJECTIVE: To investigate the effect of implantable cardioverter defibrillator (ICD) on primary prevention of sudden cardiac death (SCD) in patients with high risk. METHODS: This retrospective analysis included 70 patients who received primary prevention of SCD by ICD implantation in Huzhou Central Hospital from March 2016 to May 2019. Based on survival, 15 patients who died during follow-up were placed into the death group and the 55 patients who survived were set as the survival group. The two groups were compared in terms of sex, age, non-sustained ventricular tachycardia (VT), diastolic pressure, systolic pressure, left ventricular ejection fraction (LVEF), urea nitrogen, serum creatinine, history of diabetes, history of atrial fibrillation, history of myocardial ischemia, history of dilated cardiomyopathy, history of hypertrophic cardiomyopathy, type I Brugada wave and cardiac function classification. Further, we analyzed the proportion of discharge, the survival of patients (Kaplan Meier method), and the risk factors of patient death (Logistic regression). RESULTS: The analysis of baseline data showed that patients in the death group had older age and higher level of serum creatinine than the survival group (P<0.05), and the number of patients with non-sustained VT≥5 times/24 h in the survival group was higher than that in the death group (P<0.05). There was no obvious difference in other baseline indexes between the two groups (P>0.05). In addition, there was no difference in the proportion of patients receiving appropriate/inappropriate discharge (P>0.05) between the two groups. Follow-up data showed that 15 cases (21.43%) of spontaneous VT/ventricular fibrillation events were correctly diagnosed by pacemakers and properly treated by ICD (discharge or antitachycardia pacing (ATP)), while 55 cases (78.57%) received inappropriate ICD treatment. There were 15 patients (21.43%) who died during follow up, including 6 cases of cardiac insufficiency, 1 case of SCD, 2 cases of acute myocardial infarction, 1 case of respiratory failure, and 5 cases of unknown etiology; the survival time was (20.27±7.06) months. Logistic regression analysis showed that age and serum creatinine were the risk factors of patient death. CONCLUSION: Primary prevention with ICD implantation benefits SCD patients. Non persistent VT≥5 times/24 h is a predictive value for ICD implantation in patients receiving primary prevention of SCD. Age and serum creatinine are risk factors for death.

The impact of environment-friendly short videos on consumers' low-carbon tourism behavioral intention: A communicative ecology theory perspective.

As key participants in tourism activities, the tourists have an important role in the carbon emissions. Therefore, it is essential to identify the key elements that can arouse consumers' low-carbon tourism behavioral intention; this has become an important topic for the academic community. However, to the best of my knowledge, most studies have explored the process of formation of consumers' low-carbon tourism behavioral intention from the cognitive or emotional perspective, and have seldom paid attention to the communication perspective. As a result, the interpretation and prediction of consumers' low-carbon tourism behavioral intention is limited. Based on the framework of communicative ecology theory (CET) and stimulus-organism-response theory (SOR), our study constructs an integrated model of the relationship between environment-friendly short video experience and consumers' low-carbon tourism behavioral intention at the technological, content and social levels, introduces emotional elements such as empathy with nature and perceived environmental responsibility. Structural equation model and bootstrap method were employed for analyzing the data. Results revealed that the presence and perception of environmental education are the cognitive factors that impact consumers' low-carbon tourism behavioral intention; these can effectively stimulate consumers' low-carbon tourism behavioral intention. Empathy with nature and perceived environmental responsibility are the emotional factors that impact consumers' low-carbon tourism behavior; they play significant mediating roles between environment-friendly short video experience (presence, perception of environmental education, online interaction) and consumers' low-carbon tourism behavioral intention. On the one hand, the research conclusions enrich the perspective and content of the research on consumers' low-carbon tourism behavioral intention and its influencing mechanism; on the other hand, they acquaint with the practical significance of implementing environmental education via the emerging communication modes such as short videos, improve consumers' awareness of their environmental responsibility, and promote environmental governance and sustainable development of tourist destinations.

Transition-metal-free Synthesis of tetra-substituted Vinyl Iodides by Cascade Sequential Reaction of α-Keto Acids, 1-Iodoalkynes, and Alkyl Halides.

The cascade sequential reaction of α-keto acids, 1-iodoalkynes, and alkyl halides are reported herein to synthesize tetra-substituted vinyl iodides. It represents an efficient protocol to access a diverse range of tetra-substituted vinyl iodides starting from simple materials in a one-pot fashion, featuring mild reaction conditions, ease of operation, and broad substrate scope.

Recent Advances in the Electrochemical Functionalization of Isocyanides.

Isocyanides are well-known as efficient CO surrogates and C1 synthons in modern organic synthesis. Although tremendous efforts have been devoted to fully exploiting the reactivity of isocyanides, these transformations are primarily limited by their utilization of stoichiometric toxic chemical oxidants. With the recent resurgence of organic electrochemistry, which has considerably laid dormant over the past several decades, electrolysis has been identified as a green and powerful tool to enrich structural diversity by solely utilizing electric current as clean and inherently safe redox equivalents of stoichiometric chemical oxidants. In this regard, the unique reactivity of isocyanides has been studied in numerous electrochemical transformations. This review comprehensively highlights the most relevant progress in electrochemical strategies towards the functionalization of isocyanides up until June of 2022, with a focus on reaction outcomes and mechanisms.

High temperature boosts resistant starch content by altering starch structure and lipid content in rice ssIIIa mutants.

High temperature (HT) during grain filling had adverse influences on starch synthesis. In this study, the influences of HT on resistant starch (RS) formation in rice were investigated. Most genes in ssIIIa mutants especially in RS4 were upregulated under Normal Temperature (NT) while downregulated under HT when compared with those of wild parent R7954. ssIIIa mutants had higher RS content, more lipid accumulation, higher proportion of short chains of DP 9-15, and less long chains of DP ≥37. ssIIIa mutation exacerbated the influences of HT on starch metabolite and caused larger declines in the expression of BEI, BEIIa, BEIIb, and SSIVb when exposed to HT. HT reduced the contents of total starch and apparent amylose significantly in wild type but not in mutants. Meanwhile, lipids were enriched in all varieties, but the amounts of starch-lipid complexes and the RS content were only heightened in mutants under HT. HT led to greatest declines in the amount of DP 9-15 and increases in the proportion of fb3 (DP ≥37); the declines and increases were all larger in mutants, which resulted in varied starch crystallinity. The increased long-chain amylopectin and lipids may be the major contributor for the elevated RS content in mutants under HT through forming more starch-lipid complexes (RSV).

BF3·Et2O-Mediated annulation of α-keto acids with aliphatic ketones for the synthesis of γ-hydroxy-butenolides and γ-alkylidene-butenolides.

Annulation reaction of α-keto acids with cyclic or acyclic aliphatic ketones is reported herein to divergently access γ-hydroxy-butenolides and γ-alkylidene-butenolides depending on the amount of BF3·Et2O. This protocol features good functional tolerance and ease of operation, to open a route to access butenolides via an annulation and dehydration process.

Evaluation of Left Ventricular Systolic Function in Patients with Coronary Microvascular Dysfunction by Three-Dimensional Speckle-Tracking Imaging

Abstract Introduction: The objective of this study is to evaluate the left ventricular systolic function of patients with coronary microvascular dysfunction (CMD) using the three-dimensional speckle-tracking imaging (3D-STI) technique. Methods: From June 2018 to June 2019,72 subjects from Huzhou Central Hospital were enrolled, including 42 CMD in-patients with typical chest pain or chest tightness and positive treadmill exercise stress test, but without coronary stenosis on coronary angiography, (the CMD group) and another 30 healthy individuals who were undergoing physical examinations in an outpatient clinic (the control group). Using 3D-STI technique, the global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), global area strain (GAS), and left ventricle were measured. Results: Compared with the control group, GLS and GAS were significantly reduced in the CMD group (P<0.05), while GRS and GCS were similar in both groups (P>0.05). Univariate logistic regression analysis showed that GLS and GAS were the influencing factors of CMD. For the diagnosis of CMD, the area under the receiver operating characteristic (ROC) curve of GLS was 0.883, and the area under the ROC curve of GAS was 0.875. GAS of -29.3% (log-rank test chi-square=34.245, P<0.001) was a strong predictor of major adverse cardiac events. Conclusion: 3D-STI technique has obvious advantages in the evaluation of the left ventricular systolic function for CMD patients. Moreover, 3D-STI parameters, especially GLS and GAS, can detect the early abnormal changes in the ischaemic myocardium. Being timelier and more sensitive than echocardiography, 3D-STI should be recommended for clinical application.

Leaf Venation Architecture in Relation to Leaf Size Across Leaf Habits and Vein Types in Subtropical Woody Plants.

Leaves are enormously diverse in their size and venation architecture, both of which are core determinants of plant adaptation to environments. Leaf size is an important determinant of leaf function and ecological strategy, while leaf venation, the main structure for support and transport, determines the growth, development, and performance of a leaf. The scaling relationship between venation architecture and leaf size has been explored, but the relationship within a community and its potential variations among species with different vein types and leaf habits have not been investigated. Here, we measured vein traits and leaf size across 39 broad-leaved woody species within a subtropical forest community in China and analyzed the scaling relationship using ordinary least squares and standard major axis method. Then, we compared our results with the global dataset. The major vein density, and the ratio of major (1° and 2°) to minor (3° and higher) vein density both geometrically declined with leaf size across different vein types and leaf habits. Further, palmate-veined species have higher major vein density and a higher ratio of major to minor vein density at the given leaf size than pinnate-veined species, while evergreen and deciduous species showed no difference. These robust trends were confirmed by reanalyzing the global dataset using the same major vein classification as ours. We also found a tradeoff between the cell wall mass per vein length of the major vein and the major vein density. These vein scaling relationships have important implications on the optimization of leaf size, niche differentiation of coexisting species, plant drought tolerance, and species distribution.

Evaluation of Left Ventricular Systolic Function in Patients with Coronary Microvascular Dysfunction by Three-Dimensional Speckle-Tracking Imaging.

INTRODUCTION: The objective of this study is to evaluate the left ventricular systolic function of patients with coronary microvascular dysfunction (CMD) using the three-dimensional speckle-tracking imaging (3D-STI) technique. METHODS: From June 2018 to June 2019,72 subjects from Huzhou Central Hospital were enrolled, including 42 CMD in-patients with typical chest pain or chest tightness and positive treadmill exercise stress test, but without coronary stenosis on coronary angiography, (the CMD group) and another 30 healthy individuals who were undergoing physical examinations in an outpatient clinic (the control group). Using 3D-STI technique, the global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), global area strain (GAS), and left ventricle were measured. RESULTS: Compared with the control group, GLS and GAS were significantly reduced in the CMD group (P<0.05), while GRS and GCS were similar in both groups (P>0.05). Univariate logistic regression analysis showed that GLS and GAS were the influencing factors of CMD. For the diagnosis of CMD, the area under the receiver operating characteristic (ROC) curve of GLS was 0.883, and the area under the ROC curve of GAS was 0.875. GAS of -29.3% (log-rank test chi-square=34.245, P<0.001) was a strong predictor of major adverse cardiac events. CONCLUSION: 3D-STI technique has obvious advantages in the evaluation of the left ventricular systolic function for CMD patients. Moreover, 3D-STI parameters, especially GLS and GAS, can detect the early abnormal changes in the ischaemic myocardium. Being timelier and more sensitive than echocardiography, 3D-STI should be recommended for clinical application.

2D amorphous bi-metallic NiFe nitrides for a high-efficiency oxygen evolution reaction.

Two-dimensional bi-metallic NiFe nitrides (2D NiFe-N) are successfully synthesized in the designed ternary deep eutectic solvents under the guidance of DFT calculations. Taking advantage of the unique properties of large-size, ultrathin amorphous 2D structure and modulable electronic structure, the NiFe0.05-N exhibits extraordinary OER performance with relatively low overpotential of 238 mV at 10 mA cm-2 and durable stability.

The Effects of Partially or Completely Substituted Dietary Zinc Sulfate by Lower Levels of Zinc Methionine on Growth Performance, Apparent Total Tract Digestibility, Immune Function, and Visceral Indices in Weaned Piglets.

The study aimed to evaluate the effects of replacing zinc sulfate (ZnSO4) with a lower level of zinc methionine (ZnMet) on the growth performance, apparent total tract digestibility (ATTD) of nutrients, serum metabolites and immune functions of weaned piglets. Thirty-five weaned Duroc × Landrace × Large White male piglets (10.69 ± 0.26 kg) were randomly allotted to five diets. The control diet was supplemented with 100 mg/kg of Zn from ZnSO4, and experimental diets included 75 + 12.5, 50 + 25, 25 + 37.5, and 0 + 50 mg/kg of Zn from ZnSO4 and ZnMet, respectively. The results showed that no differences were observed in growth performance, ATTD of nutrients and serum metabolites among treatments, while serum white blood cell count, lymphocyte count, IgM contents and spleen index were higher (p < 0.01) in piglets fed with 50 + 25 mg/kg of Zn. Zinc digestibility (p < 0.05), IgA content (p < 0.001) and thymus index (p < 0.05) were increased when at least 50% of ZnSO4 was replaced by ZnMet. All the results indicated that using a lower level of ZnMet in weaned piglet's diet instead of ZnSO4 had no adverse impacts on ATTD of nutrients and serum metabolites; and a 50 + 25 mg/kg of Zn (from ZnSO4 and ZnMet, respectively) diet showed the best advantages for parameters relating to immune functions.

PTEN signaling inhibitor VO-OHpic improves cardiac myocyte survival by mediating apoptosis resistance in vitro.

BACKGROUND: Acute myocardial infarction (AMI) is a server disease effecting a large population worldwide. The pathophysiological process of ischemic/reperfusion (I/R) plays an important role for heart tissue damage. VO-OHpic, a PTEN inhibitor, has been demonstrated to be cardiac protective in sudden cardiac arrest models, but its role in AMI remains unclear. METHODS: An isolated AMI model was induced by dissecting the rat heart in a Langendorff system. Cardiac myocytes were extracted and induced ischemia in vitro. VO-OHpic was added into the above systems. The area of infarcted tissue in the heart was measured. Cardiac myocyte apoptosis was assessed by flow cytometry. Activation of Akt and GSK3ß was quantified by flow cytometry. IL-10 levels were determined by ELISA. RESULTS: VO-OHpic reduced infarcted areas in the isolated heart, and improved cultured cardiac myocyte survival. VO-OHpic induced apoptosis resistance in cardiac myocytes. Akt-GSK3ß signaling was activated by VO-OHpic administration. IL-10 levels in the medium were elevated by VO-OHpic. CONCLUSION: VO-OHpic protects heart tissue by apoptosis resistance via activating Akt-GSK3ß signaling and increasing IL-10 levels.

Shedding lights on the flexible-armed porphyrins: Human telomeric G4 DNA interaction and cell photocytotoxicity research.

DNA polymorphism exerts a fascination on a large scientific community. Without crystallographic structural data, clarification of the binding modes between G-quadruplex (G4) and ligand (complex) is a challenging job. In the present work, three porphyrin compounds with different flexible carbon chains (arms) were designed, synthesized and characterized. Their binding, folding and stabilizing abilities to human telomeric G4 DNA structures were comparatively researched. Positive charges at the end of the flexible carbon chains seem to be favorable for the DNA-porphyrin interactions, which were evidenced by the spectral results and further confirmed by the molecular docking calculations. Biological function analysis demonstrated that these porphyrins show no substantial inhibition to Hela, A549 and BEL 7402 cancer cell lines under dark while exhibit broad inhibition under visible light. This significantly enhanced photocytotoxicity relative to the dark control is an essential property of photochemotherapeutic agents. The feature of the flexible arms emerges as critical influencing factors in the cell photocytotoxicity. Moreover, an ROS-mediated mitochondrial dysfunction pathway was suggested for the cell apoptosis induced by these flexible-armed porphyrins. It is found that the porphyrins with positive charges located at the end of the flexible arms represent an exciting opportunity for photochemotherapeutic anti-cancer drug design.

[Association of T190C polymorphism of ß3 adrenergic receptor gene with response to carvedilol in patients with chronic heart failure].

OBJECTIVE: To assess the association of T190C polymorphism of ß3 adrenergic receptor gene (ß3-AR) with chronic heart failure (CHF), and to evaluate the effect of this polymorphism on clinical response to ß-AR blockade among patients with CHF. METHODS: Three hundred and thirty patients with stable CHF receiving basic therapy for heart failure were included. Before initiation and 5 months after the maximal tolerated dose of carvedilol was reached, all indices including heart rate (HR), blood pressure (BP), left atrial diameter (LAD), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), brain natriuretic peptide (BNP) level, 6 min walk distance were measured and compared with the indices of those with a T190C genotype. Distribution of the T190C polymorphisms in the control group and CHF group was compared. RESULTS: The frequencies of T190C genotypes of the ß3-AR gene have fit with the Hardy-Weinberg equilibrium. No significant difference was found between the frequencies of T190C alleles and genotypes between the two groups (P > 0.05). Compared with CC-homozygotes, TT-homozygous patients showed substantially greater improvement in LVEF and BNP (all P < 0.01). CONCLUSION: No difference has been detected in the prevalence of the three genotypes between healthy and CHF subjects. The T190C variation of the ß3-AR gene was not associated with increased risk for CHF. CHF patients with a T allele have greater response to carvedilol than those carrying a C allele in ethnic Han Chinese.

The single nucleotide polymorphisms of Kir3.4 gene and their correlation with lone paroxysmal atrial fibrillation in Chinese Han population.

BACKGROUND: Acetylcholine induced inwardly rectifying current (I(KACh)) is a heteromultimeric complex formed by Kir3.1 and Kir3.4 subunits and plays important roles in the development of atrial fibrillation (AF). AF is a common disorder among Chinese, the frequency of AF is about 0.61%, and in patients with strokes it is 12.1%. We hypothesise that lone paroxysmal AF genetic variation in Kir3.4 may predispose the atria to fibrillation in the Chinese population. METHODS: We recruited 186 patients with lone paroxysmal AF, and 210 matched controls by age (49.61+/-8.04 years), sex, smoking habit, and left atrial dimension in Zhejiang Province, China. Genotype of Kir3.4 was determined with polymerase chain reaction (PCR) and direct sequencing. The SPSS statistical software was used for chi(2) test. LD and haplotypes were calculated using SHESIS software package. RESULTS: Three synonymous known single nucleotide polymorphisms (SNPs) in Kir3.4 were genotyped, including C171T (rs6590357), G810T (rs7118824) and C834T (rs7118833). We found low levels of linkage disequilibrium (LD) between C171T and G810T (D'=0.272), complete LD between SNPs G810T and C834T (D'=1) in AF patients and controls. The case-control analysis revealed that the frequency of genotype and allele in three SNPs are significantly different between lone paroxysmal AF patients than in control subjects. The odds ratio (OR) for AF 171T and 810T alleles were 1.546 (95% CI 1.015-2.355) and 1.520 (95% CI 1.012-2.284), respectively, when compared with patients without Kir3.4T alleles in these two loci. The OR for AF in patients with C-T genotype were 13.364 (95% CI 5.710-31.278) and 37.135 (95% CI 9.050-152.381) when comparing patients with T-G genotype. CONCLUSIONS: Our findings suggest that C171T and G810T SNPs in Kir3.4 gene might be risk factors for lone paroxysmal AF in Chinese population.