Biomedical subjects

Xu Liu

Publications and source records attributed to Xu Liu.

At least 19 recordsLinked to original sources

PubMed2026

Temporal shifts in K-locus composition and expansion of dual-carbapenemase-producing ST11-KL62 Klebsiella pneumoniae: a retrospective genomic surveillance study.

OBJECTIVES: To characterize longitudinal changes in carbapenem-resistant Klebsiella pneumoniae (CRKP) and investigate the recent increase in dual-carbapenemase-producing ST11-KL62 isolates. METHODS: We retrospectively analysed 1,239 non-duplicate CRKP isolates recovered at a tertiary hospital in China during 2018-2025. Antimicrobial susceptibility testing, whole-genome sequencing, K-locus and resistance/virulence gene profiling, core-genome single-nucleotide polymorphism analysis, reference-guided plasmid comparison, conjugation and stability assays, and a murine lethality model were used. RESULTS: ST11 accounted for 936/1,239 isolates (75.5%). KL47 declined from 39/151 (25.8%) in 2018-2019 to 45/755 (6.0%) in 2024-2025, whereas KL62 increased from 3/151 (2.0%) to 147/755 (19.5%). Among 148 ST11-KL62 isolates, 13/148 (8.8%) co-harboured blaKPC-2 and blaNDM-1, of which 12/13 (92.3%) met the study's molecular definition of hypervirulent CRKP. Pairwise single-nucleotide polymorphism distances among local ST11-KL62 isolates ranged from 0 to 43 (median, 14), suggesting that clonal expansion may have contributed to their increase. Complete genome analysis of ZD872 located blaKPC-2, blaNDM-1, and major virulence-associated genes on distinct plasmids; related plasmid backbones were predicted in other isolates using short-read comparisons. ZD872 exhibited a hypervirulent phenotype in the murine model. CONCLUSIONS: The ST11 CRKP population underwent temporal shifts in K-locus composition, including expansion of a closely related ST11-KL62 subset carrying dual carbapenemases and hypervirulence-associated markers. These findings support integrating longitudinal genomic surveillance with local transmission analysis.

Carbapenem-resistant Klebsiella pneumoniae↗

PubMed2026

Serum Olink Proteomics Reveals Novel Biomarkers for Early Diagnosis of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a highly prevalent malignant tumor in China, and early diagnosis critically affects the prognosis. Current imaging and pathological biopsy techniques have limitations, including high invasiveness and limited accessibility, while the insufficient sensitivity of serum biomarkers (such as AFP) restricts their use in early screening. In this study, using the Olink proteomics platform based on the proximity extension assay (PEA), we screened for hepatocellular carcinoma-related differentially expressed proteins (DEPs) and constructed a multiprotein diagnostic model. In the discovery cohort, we included 15 patients with newly diagnosed HCCs and 16 healthy controls. DEPs were identified using Olink, and their diagnostic performance was analyzed to identify the candidate biomarkers. In an independent validation cohort, including 116 HCC patients (50 early stage, 66 late stage) and 83 healthy controls, we further validated the expression levels and diagnostic performance of identified proteins─C1QA and GFER. The C1QA and GFER expression levels were significantly higher in the serum of patients with early and late HCC stages compared to healthy controls. By constructing a multiprotein diagnostic model, we identified C1QA, GFER, and AFP as the optimal diagnostic combination, demonstrating a combined diagnostic AUC of 0.92 and 0.99 for early-stage and advanced-stage HCC, respectively.

Humans↗

PubMed2026

Causal relationship between asthma and hernia risk: A Mendelian randomization study.

Epidemiological associations between asthma and various hernia subtypes have been reported, but the causality and direction remain unclear. This study employs a two‑sample Mendelian randomization (MR) approach to systematically assess the causal associations between asthma and 6 hernia subtypes. Using publicly available summary data of genome-wide association studies, asthma was selected as the exposure, and diaphragmatic hernia, umbilical hernia, femoral hernia, hiatus hernia, inguinal hernia, and ventral hernia were selected as outcomes. Instrumental variables were strictly screened (F-statistic > 10). The inverse‑variance weighted method was used as the primary analytical approach, supplemented with MR Egger and weighted median methods. Sensitivity analyses included heterogeneity tests, horizontal pleiotropy tests, Steiger directionality tests, leave‑one‑out analyses, and Radial MR. Reverse MR was performed for validation. Forward MR analyses revealed a significant positive causal effect of asthma on diaphragmatic hernia (odds ratio [OR] = 1.19, 95% confidence interval [CI]: 1.08-1.31, P < .001) and a suggestive association with umbilical hernia (OR = 1.19, 95% CI: 1.05-1.34, P = .007). The umbilical hernia association was significant only by the inverse‑variance weighted method; weighted median (P = .102) and MR-Egger (P = .210) estimates were not statistically significant, and the estimate attenuated after outlier removal (confirmatory OR = 1.13, 95% CI: 1.01-1.26, P = .028). Sensitivity analyses showed no significant heterogeneity or pleiotropy. Reverse MR did not identify significant causal effects of hernias on asthma, although power limitations for certain hernia subtypes should be considered. No significant associations were observed between asthma and the other hernia subtypes, although the null findings for femoral and ventral hernias should be interpreted with caution due to limited statistical power. This study provides genetic evidence supporting asthma as a causal risk factor for diaphragmatic hernia, with a suggestive association for umbilical hernia. The diaphragmatic hernia finding was robust across multiple sensitivity analyses, whereas the umbilical hernia association was less consistent and requires further confirmation. These findings contribute to a deeper understanding of the mechanistic links between asthma and specific hernia subtypes.

Mendelian Randomization Analysis↗

PubMed2026

Distinct spatial immune microenvironment features of different EGFR mutation subtypes in early-stage lung adenocarcinoma.

Epidermal growth factor receptor (EGFR) mutations are common in lung adenocarcinoma (LUAD), yet their influence on the spatial tumor immune microenvironment (TIME) in early-stage disease remains unclear. We characterized the spatial TIME in 144 treatment-naïve, early-stage LUADs using integrated genomic sequencing and multiplex immunohistochemistry (mIHC). Although EGFR-mutant tumors overall displayed reduced CD8 + T-cell infiltration compared with EGFR-wild-type tumors, substantial heterogeneity was observed among EGFR subtypes. Specifically, L858R and rare-variant subtypes exhibited higher tumor mutational burden, greater CD8 + T-cell density, and enrichment of T-cell-dominant cellular neighborhoods relative to 19del subtype, consistent with a comparatively immune-infiltrated phenotype. In contrast, 19del tumors showed lower T-cell infiltration. TP53 co-mutation was also associated with enhanced CD8 + T-cell infiltration. These cross-sectional findings identify hypothesis-generating spatial immune phenotypes across EGFR-mutant LUAD subtypes; their potential relevance to perioperative treatment selection requires prospective validation in outcome-annotated treatment cohorts.

Humans↗

PubMed2025

O-GlcNAcylation of nuclear proteins in the mouse liver exhibit daily oscillations that are influenced by meal timing.

The liver circadian clock and hepatic transcriptome are highly responsive to metabolic signals generated from feeding-fasting rhythm. Previous studies have identified a number of nutrient-sensitive signaling pathways that could interpret metabolic input to regulate rhythmic hepatic biology. Here, we investigated the role of O-GlcNAcylation, a nutrient-sensitive post-translational modification (PTM) in mediating metabolic regulation of rhythmic biology in the liver. We observe daily oscillation of global nuclear protein O-GlcNAcylation in the liver of mice subjected to night-restricted feeding (NRF) using label-free global O-GlcNAc proteomics. Additional site-specific O-GlcNAc analysis by tandem mass tag mass spectrometry further supports temporal differences in O-GlcNAcylation by revealing day-night differences. Proteins involved in gene expression are enriched among rhythmically O-GlcNAcylated proteins, suggesting rhythmic O-GlcNAcylation may directly regulate the hepatic transcriptome. We show that rhythmic O-GlcNAcylation can also indirectly modulate nuclear proteins by interacting with phosphorylation. Several proteins harboring O-GlcNAcylation-phosphorylation interplay motif exhibit rhythmic O-GlcNAcylation and phosphorylation. Specifically, we show that O-GlcNAcylation occurs at a phospho-degron of a key circadian transcriptional activator, circadian locomotor output cycles kaput (CLOCK), thus regulating its stability and transcriptional output. Finally, we report that day-restricted feeding (DRF) in the nocturnal mouse significantly alters O-GlcNAcylation pattern. Whereas global O-GlcNAcylation analysis indicates dampening of global O-GlcNAcylation rhythm in mice fed under DRF, site-specific analysis reveals differential responses of O-GlcNAc sites when timing of food intake is altered. Notably, a substantial number of O-GlcNAcylation sites exhibit inverted day-night profiles when mice are subjected to DRF. This suggests the dysregulation of daily nuclear protein O-GlcNAcylation rhythm may contribute to the disruption in liver transcriptome previously observed in DRF condition. In summary, our results provide new mechanistic insights into metabolic regulation of hepatic transcriptional regulators via interplay between O-GlcNAcylation and phosphorylation and shed light on the deleterious effects of improper mealtimes.

Animals↗

PubMed2024

Metagenomic analysis demonstrates distinct changes in the gut microbiome of Kawasaki diseases children.

BACKGROUND: Kawasaki disease (KD) has been considered as the most common required pediatric cardiovascular diseases among the world. However, the molecular mechanisms of KD were not fully underlined, leading to a confused situation in disease management and providing precious prognosis prediction. The disorders of gut microbiome had been identified among several cardiovascular diseases and inflammation conditions. Therefore, it is urgent to elucidate the characteristics of gut microbiome in KD and demonstrate its potential role in regulating intravenous immunoglobulin (IVIG) resistance and coronary artery injuries. METHODS: A total of 96 KD children and 62 controls were enrolled in the study. One hundred forty fecal samples had been harvested from KD patients, including individuals before or after IVIG treatment, with or without early coronary artery lesions and IVIG resistance. Fecal samples had been collected before and after IVIG administration and stored at -80°C. Then, metagenomic analysis had been done using Illumina NovaSeq 6000 platform. After that, the different strains and functional differences among comparisons were identified. RESULTS: First, significant changes had been observed between KD and their controls. We found that the decrease of Akkermansia muciniphila, Faecalibacterium prausnitzii, Bacteroides uniformis, and Bacteroides ovatus and the increase of pathogenic bacteria Finegoldia magna, Abiotrophia defectiva, and Anaerococcus prevotii perhaps closely related to the incidence of KD. Then, metagenomic and responding functional analysis demonstrated that short-chain fatty acid pathways and related strains were associated with different outcomes of therapeutic efficacies. Among them, the reduction of Bacteroides thetaiotaomicron, the enrichment of Enterococcus faecalis and antibiotic resistance genes had been found to be involved in IVIG resistance of KD. Moreover, our data also revealed several potential pathogenetic microbiome of that KD patients with coronary artery lesions. CONCLUSION: These results strongly proved that distinct changes in the gut microbiome of KD and the dysfunction of gut microbiomes should be responsible for the pathogenesis of KD and significantly impact the prognosis of KD.

Humans↗

PubMed2020

Genetic variants in migraine: a field synopsis and systematic re-analysis of meta-analyses.

OBJECTIVE: Numerous genetic variants from meta-analyses of observational studies and GWAS were reported to be associated with migraine susceptibility. However, due to the random errors in meta-analyses, the noteworthiness of the results showing statistically significant remains doubtful. Thus, we performed this field synopsis and re-analysis study to evaluate the noteworthiness using a Bayesian approach in hope of finding true associations. METHODS: Relevant meta-analyses from observational studies and GWAS examining correlation between all genetic variants and migraine risk were included in our study by a PubMed search. Identification of noteworthy associations were analyzed by false-positive rate probability (FPRP) and Bayesian false discovery probability (BFDP). Using noteworthy variants, GO enrichment analysis were conducted through DAVID online tool. Then, the PPI network and hub genes were performed using STRING database and CytoHubba software. RESULTS: As for 8 significant genetic variants from observational studies, none of which showed noteworthy at prior probability of 0.001. Out of 47 significant genetic variants in GWAS, 36 were noteworthy at prior probability of 0.000001 via FPRP or BFDP. We further found the pathways "positive regulation of cytosolic calcium ion concentration" and "inositol phosphate-mediated signaling" and hub genes including MEF2D, TSPAN2, PHACTR1, TRPM8 and PRDM16 related to migraine susceptibility. CONCLUSION: Herein, we have identified several noteworthy variants for migraine susceptibility in this field synopsis. We hope these data would help identify novel genetic biomarkers and potential therapeutic target for migraine.

Bayes Theorem↗

PubMed2006

Insect olfactory memory in time and space.

Recent studies using functional optical imaging have revealed that cellular memory traces form in different areas of the insect brain after olfactory classical conditioning. These traces are revealed as increased calcium signals or synaptic release from defined neurons, and include a short-lived trace that forms immediately after conditioning in antennal lobe projection neurons, an early trace in dopaminergic neurons, and a medium-term trace in dorsal paired medial neurons. New molecular genetic tools have revealed that for normal behavioral memory performance, synaptic transmission from the mushroom body neurons is required only during retrieval, whereas synaptic transmission from dopaminergic neurons is required at the time of acquisition and synaptic transmission from dorsal paired medial neurons is required during the consolidation period. Such experimental results are helping to identify the types of neurons that participate in olfactory learning and when their participation is required. Olfactory learning often occurs alongside crossmodal interactions of sensory information from other modalities. Recent studies have revealed complex interactions between the olfactory and the visual senses that can occur during olfactory learning, including the facilitation of learning about subthreshold olfactory stimuli due to training with concurrent visual stimuli.

Animals↗

PubMed2006

[Clinical features of undifferentiated connective tissue diseases: analysis of 145 patients].

OBJECTIVE: To investigate the clinical features and prognosis of undifferentiated connective tissue disease. (UCTD) METHODS: 1105 connective tissue disease (CTD) patients, including 751 cases of systemic lupus erythrematosus (SLE), 63 cases of systemic sclerosis (SSc), 103 cases of polymyositis/dermatomyositis (PM/DM), 159 cases of primary Sjögren's syndrome (pSS), and 29 cases of overlap syndrome (29), were randomly selected. The clinical data of these patients were analyzed to identify those who displayed the manifestations of UCTD as the onset manifestations so as to summarize the clinical manifestation, immunological parameters, and long term development of UCTD. RESULTS: These 145 patients with UCTD developed SLE, SSc, SS, PM/DM, or overlap syndrome within two to five years. The patients with arthritis and arthralgia often developed into SLE. Raynaud's syndrome was often related to SSc. The patients with rash or face edema were more likely turned out to be PM/DM patients. The patients with dry eyes or dry mouth often developed into pSS patients. CONCLUSION: UCTD can develop into various autoimmune diseases, such as SLE, SSc, pSS or PM/DM. Some clinical features of onset are related with the outcome.

Adult↗

PubMed2006

[Pulmonary vein antrum isolation guided by 3-D mapping system in 100 patients with chronic atrial fibrillation].

OBJECTIVE: To investigate the efficacy and safety of circumferential pulmonary vein (PV) linear ablation (CPVA) guided by 3-D mapping system in patients with chronic atrial fibrillation (CAF). METHODS: From August 2004 to November 2005, 100 consecutive patients with CAF were admitted to undergo CPVA guided by CARTO system and EnSite NavX system, the main procedure end point is electrical isolation of PVs. Success was defined as atrial tachyarrhythmia free without any antiarrhythmia drugs for at least 3 months. Clinical and procedural variables were collected, ANOVA analysis was employed to identify the risk factors predicting recurrence, P < 0.05 was considered significant. RESULTS: After a mean of 9.7 +/- 5.7 months follow up, 70% (70/100) of patients freed from AF. ANOVA analysis identified isthmus ablation and poor left ventricular ejection fraction as the independent factors predicting success. Complications including pericardial tamponade (3 cases, 3%), stroke (1 case, 1%), asymptomatic pulmonary vein stenosis (2 cases, 2%). CONCLUSION: CPVA guided by 3-D mapping system can be performed in CAF patients with an acceptable efficacy, but safety need to be improved.

Adult↗

PubMed2006

Principal component-based radiative transfer model for hyperspectral sensors: theoretical concept.

Modern infrared satellite sensors such as the Atmospheric Infrared Sounder (AIRS), the Cross-Track Infrared Sounder (CrIS), the Tropospheric Emission Spectrometer (TES), the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS), and the Infrared Atmospheric Sounding Interferometer (IASI) are capable of providing high spatial and spectral resolution infrared spectra. To fully exploit the vast amount of spectral information from these instruments, superfast radiative transfer models are needed. We present a novel radiative transfer model based on principal component analysis. Instead of predicting channel radiance or transmittance spectra directly, the principal component-based radiative transfer model (PCRTM) predicts the principal component (PC) scores of these quantities. This prediction ability leads to significant savings in computational time. The parameterization of the PCRTM model is derived from the properties of PC scores and instrument line-shape functions. The PCRTM is accurate and flexible. Because of its high speed and compressed spectral information format, it has great potential for superfast one-dimensional physical retrieval and for numerical weather prediction large volume radiance data assimilation applications. The model has been successfully developed for the NAST-I and AIRS instruments. The PCRTM model performs monochromatic radiative transfer calculations and is able to include multiple scattering calculations to account for clouds and aerosols.

Journal Article↗

PubMed2006

Genetic diversity in Chinese modern wheat varieties revealed by microsatellite markers.

Genetic diversity of 1680 modern varieties in Chinese candidate core collections was analyzed at 78 SSR loci by fluorescence detection system. A total of 1336 alleles were detected, of which 1253 alleles could be annotated into 71 loci. For these 71 loci, the alleles ranged from 4 to 44 with an average of 17.6, and the PIC values changed from 0.19 to 0.89 with an average of 0.69. (1) In the three genomes of wheat, the average genetic richness was B>A>D, and the genetic diversity indexes were B>D>A. (2) Among the seven homoeologous groups, the average genetic richness was 2=7>3>4>6>5>1, and the genetic diversity indexes were 7>3>2>4>6>5>1. As a whole, group 7 possessed the highest genetic diversity, while groups 1 and 5 were the lowest. (3) In the 21 wheat chromosomes, 7A, 3B and 2D possessed much higher genetic diversity, while 2A, 1B, 4D, 5D and 1D were the lowest. (4) The highest average genetic diversity index existed in varieties bred in the 1950s, and then it declined continually. However, the change tendency of genetic diversity among decades was not greatly sharp. This was further illustrated by changes of the average genetic distance between varieties. In the 1950s it was the largest (0.731). Since the 1960s, it has decreased gradually (0.711, 0.706, 0.696, 0.695). The genetic base of modern varieties is becoming narrower and narrower. This should be given enough attention by breeders and policy makers.

Alleles↗

PubMed2006

Vaccinia virus intermediate and late promoter elements are targeted by the TATA-binding protein.

Vaccinia virus replicates in the cytoplasm of the host cell and encodes its own RNA polymerase and transcription factors. The proteins that target the poxvirus RNA polymerase to intermediate- and late-class promoters have not been identified. In this study, representatives of the intermediate and late promoters were characterized at the nucleotide level to identify essential motifs. Both intermediate and late viral promoters are shown to have an essential element suggestive of TATA boxes, which are potential targets for the TATA-binding protein (TBP). Several approaches were used to test for TBP requirement in vaccinia virus transcription, including overexpression of TBP, expression of a dominant negative mutant of TBP, RNA interference, and expression of adenovirus E1A protein, which inactivates TBP. In each case, the results support an essential role for TBP in vaccinia virus intermediate- and late-gene transcription. These findings indicate that poxviruses have integrated TBP as a central feature into an otherwise heterologous transcription system. A model for transcriptional switching, in which both intermediate and late promoter elements are targeted by TBP that recruits viral transcription factors to assemble a functional complex on their cognate promoters and a dysfunctional, repressed complex on the other class, is proposed.

Adenovirus E1A Proteins↗

PubMed2006

[The function of F-box protein in plant growth and development].

Ubiquitin-mediated proteolysis is involved in many biological processes in eukaryotes. SCF complex is a very important ubiquitin E3 ligase which has been exploited very well in plants. F-box protein characterized by an F-box motif is a subunit of SCF complex, which works as determinant in substrate recognition. Currently, many F-box proteins have been identified in plants which are involving in hormone (e.g., ethylene, auxin, gibberellin and jasmonate ) signal transduction and biological processes, such as self-incompatibility and floral development. F-box proteins may also participate stress response in plants. Recent study suggested that the Arabidopsis F-box protein TIR1 is an auxin receptor. Therefore, F-box protein mediated proteolysis may be an important gene expression mechanism in plants.

F-Box Proteins↗

PubMed2005

Concurrent expression of aryl hydrocarbon receptor and CYP1A1 but not CYP1A1 MspI polymorphism is correlated with gastric cancers raised in Dalian, China.

The frequency of cancer-associated m2m2- (C-) genotype of CYP1A1 and the factors contributing to the increased CYP1A1 expression in gastric cancers (GCs) are largely unknown. To address theses issues, PCR-restriction fragment length polymorphism (PCR-RFLP) was performed to elucidate the MspI polymorphism in 60 GC cases and 57 normal donor samples. The frequencies of m1m1-, m1m2- and m2m2-genotype were 43.3, 45 and 11.7% among GC patients and 45.6, 49.1 and 5.3% among the normal donors respectively, demonstrating no significant difference of them between cancer and control groups (chi(2)=0.343, P=0.558). The correlation of Aryl hydrocarbon receptor (AhR) with the frequent CYP1A1 expression in stepwise gastrocarcinogenesis was determined by RT-PCR, immunohistochemical staining (IHC) and Western blotting, using GC samples as well as their pre-malignant and non-cancerous counterparts. RT-PCR revealed that the AhR detection rates were 100, 94.12 and 85.17% in GC, pre-malignant and non-cancerous mucosa (P>0.05) respectively but the level of AhR expression in GCs was much higher than that of non-cancerous tissues. IHC showed that the frequencies of AhR detection were 94.87% (37/39) in GCs, 94.12% (16/17) in pre-malignant lesions and 50% (3/6) in non-cancerous mucosa, revealing significant difference in frequencies of AhR detection and levels of AhR expression between GC or pre-malignant group and non-cancerous one (P<0.05). The frequency of AhR nucleus translocation was significantly high in GCs (94.87%; 37/39) than that in pre-malignant (70.59%; 12/17) and especially in non-cancerous group (16.67%; 1/6). Co-existence of AhR nuclear translocation and CYP1A1 expressions were found in 82.70% (43/52) of GCs (r(s)=0.437, P<0.01). Our results suggest (1) that CYP1A1 MspI polymorphism may not contribute to the high gastric cancer risk in Dalian region and (2) that enhanced AhR expression and especially its nuclear translocation may be a favorable factor for GC formation presumably via up-regulating CYP1A1 expression.

Case-Control Studies↗

PubMed2005

Seasonal variations of phenolic compounds in Australia-grown tea (Camellia sinensis).

Seasonal variations of phenolic compounds in fresh tea shoots grown in Australia were studied using an HPLC method. Three principal tea flavanols [epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and epigallocatechin (EGC)] and four grouped phenolics [total catechins (Cs), total catechin gallates (CGs), total flavanols (Fla), and total polyphenols (PPs)] in fresh tea shoots were analyzed and compared during the commercial harvest seasons from April 2000 to May 2001. The levels of EGCG, ECG, and CGs in the fresh tea shoots were higher in the warm months of April 2000 (120.52, 34.50, and 163.75 mg/g, respectively) and May 2000 (128.63, 44.26, and 183.83 mg/g, respectively) and lower during the cool months of July 2000 (91.39, 35.16, and 132.30 mg/g, respectively), August 2000 (91.31, 31.56, and 128.64 mg/g, respectively), and September 2000 (96.12, 33.51, and 136.90 mg/g, respectively). Thereafter, the levels increased throughout the warmer months from October to December 2000 and remained high until May 2001. In the warmer months, the levels of EGCG, ECG, and CGs were in most cases significantly higher (P < 0.05) than those in the samples harvested in the cooler months. In contrast, the levels of EGC and Cs were high and consistent in the cooler months and low in the warmer months. The seasonal variations of the individual and grouped catechins were significant (P < 0.05) between the cooler and warmer months. This study revealed that EGCG and ECG could be used as quality descriptors for monitoring the seasonal variations of phenolics in Australia-grown tea leaves, and the ratio (EGCG + ECG)/EGC has been suggested as a quality index for measuring the differences in flavanol levels in fresh tea shoots across the growing seasons. Mechanisms that induce seasonal variations in tea shoots may include one or all three of the following environmental conditions: day length, sunlight, and/or temperature, which vary markedly across seasons. Therefore, further studies under controlled conditions such as in a greenhouse may be required to direct correlate flavonoid profiles of green tea leaves with their yields and also to with conditions such as rainfall and humidity.

Australia↗

PubMed2005

Electroanatomical systems to guided circumferential pulmonary veins ablation for atrial fibrillation: initial experience from comparison between the Ensite/NavX and CARTO system.

BACKGROUND: The circumferential pulmonary vein ablation (CPVA) has been proved effective for atrial fibrillation (AF) treatment and is becoming more widely accepted and practiced. This study aims to evaluate the characteristics of the CARTO and the Ensite/NavX system and draw a comparison between them on the aspects of procedural parameters and clinical effectiveness. METHODS: Seventy-five cases with paroxysmal or chronic symptomatic AF were randomly assigned to CPVA procedure guided by the Ensite/NavX system (group I, n = 40) and by the CARTO system (group II, n = 35). After successful transseptal procedure, the geometry of left atrium was created under the guidance of the two systems. Radiofrequency energy was applied to circumferentially ablate tissues out of pulmonary veins' (PVs') ostia. In cases with chronic AF, linear ablation was applied to modify the substrate of left atrium (LA). The endpoint of the procedure was complete PVs isolation. RESULTS: Seventy-five cases underwent the procedure successfully. The total procedure and fluoroscopic durations in group II were significantly shorter than in group I [(150 +/- 23) min and (18 +/- 17) min versus (170 +/- 34) min and (25 +/- 16) min, P = 0.03 and 0.04, respectively]. There was no significant difference in the fluoroscopic and procedure durations for geometry creation between group I and group II [(8 +/- 4) min and (16 +/- 11) min versus (5 +/- 4) min and (14 +/- 8) min, respectively]. The fluoroscopic durations for CPVA were (15 +/- 5) min in group I versus (10 +/- 6) min in group II (P = 0.05), and the CPVA procedural durations were significantly shorter in group II than in group I [(18 +/- 11) min versus (25 +/- 10) min, P = 0.04]. AF was terminated by radio frequency delivery in 14 cases (35%) in group I versus 5 cases (14%) in group II (P = 0.035). After CPVA complete PV isolation was attained in 26 cases (65%) in group I versus 11 cases (31%) in group II (P = 0.004). During a mean follow-up of 7 months, 32 (80%) cases in group I and 24 (69%) cases in group II were arrhythmia-free (P = 0.06). One case developed pericardium effusion and another one case was found to have intestinal artery thrombosis in group II. One case had moderate hemothorax in group I. All the complications were cured by proper treatment. No PV stenosis was observed. CONCLUSIONS: The CPVA procedure for atrial fibrillation is effective and safe. Although there is difference between the CARTO and the Ensite/NavX system, the CPVA procedure guided by either of them yields similar clinical results.

Adult↗

PubMed2005

Tropospheric CO observed with the NAST-I retrieval methodology, analyses, and first results.

High-resolution infrared spectra from aircraft and space-based observations contain information about tropospheric carbon monoxide (CO) as well as other trace species. A methodology for retrieving tropospheric CO from such remotely sensed spectral data has been developed for the National Polar-Orbiting Operational Environmental Satellite System's Airborne Sounder Testbed-Interferometer (NAST-I). CO profiles of the troposphere, together with its thermodynamic properties, are determined by use of a three-stage retrieval approach that combines the algorithms of physically based statistical eigenvector regression, simultaneous and iterative matrix inversion, and single-variable error-minimization CO profile matrix inverse retrieval. The NAST-I is collecting data while it is aboard high-altitude aircraft throughout many field campaigns. Detailed retrieval analyses based on the NAST-I instrument system along with retrieval results from several recent field campaigns are presented to demonstrate NAST-I CO retrieval capability.

Journal Article↗