Search

A centered $$L^2$$ -norm based test statistic is used for testing if a high-dimensional mean vector equals zero where the data dimension may be much larger than the sample size. Inspired by the fact that under some regularity conditions the asymptotic null distributions of the proposed test are the same as the limiting distributions of a chi-square-mixture, a three-cumulant matched chi-square-approximation is suggested to approximate this null distribution. The asymptotic power of the proposed test under a local alternative is established and the effect of data non-normality is discussed. A simulation study under various settings demonstrates that in terms of size control, the proposed test performs significantly better than some existing competitors. Several real data examples are presented to illustrate the wide applicability of the proposed test to a variety of high-dimensional data analysis problems, including the one-sample problem, paired two-sample problem, and MANOVA for correlated samples or independent samples.

High-dimensional data are frequently encountered with the development of modern data collection techniques. Testing the equality of the mean vectors of two high-dimensional samples with possibly different covariance matrices is usually referred to as a high-dimensional two-sample Behrens–Fisher (BF) problem. In the high-dimensional setting, the classical BF solutions are expected to perform poorly or become inapplicable due to the singularity of the sample covariance matrices. Several approaches have been proposed in the literature to address this challenging issue but they all require strong regularity conditions on the underlying covariance matrices to guarantee that their test statistics are asymptotically normally distributed. To overcome this difficulty, an L 2 -norm-based test is proposed and studied in this article. It is shown that under some regularity conditions and the null hypothesis, the test statistic and a chi-square-type mixture have the same normal or non-normal limiting distribution. It is then natural to approximate the null distribution of the proposed test using that of the chi-square-type mixture, which is actually obtained from the proposed test statistic when the two high-dimensional samples are normally distributed. The resulting test is then referred to as a normal reference test. The distribution of the chi-square-type mixture can then be well approximated by the Welch–Satterthwaite χ 2 -approximation with the approximation parameters consistently estimated from the data. The asymptotic power of the proposed test is established. Good performance of the proposed test against several existing competitors is demonstrated via several simulation studies and illustrated by a real data example.

BackgroundThis study describes the electrophysiologic characteristics of the para-hisian accessory pathway (AP), the outcome of different ablation approaches, and ablation safety at different sites.MethodA total of 120 patients diagnosed as para-hisian AP were included in this study. The electrophysiologic characteristics and outcomes at different ablation sites were analyzed.ResultsIn total, 107 APs and 13 APs were diagnosed as right anteroseptal (RAS) and right midseptal (RMS), respectively. The significant ECG difference between RAS and RMS was lead III, which mainly manifested as positive and negative delta waves, respectively. Catheter trauma to AP was recorded in 21 of 120 (17.5%) patients. The recurrence rate of direct ablation at the “bumped” sites was higher than the conventional ablation method (37.5 vs. 14.1 %, p = 0.036). For RAS APs, there was no significant difference in the success rate between the inferior vena cava (IVC) and superior vena cava (SVC) approaches (76.6 vs. 73.3%, p = 0.63). The RAS was separated into three regions: (1) Site 1: superior part above the real “His” recorded site with far-field “His” potential; (2) Site 2 (true para-hisian): the site with near-field “His” potential; and (3) Site 3: inferior part below the biggest real “His” with far-field “His” potential. Mid-septal was defined as an area that is bounded anteriorly by His recording location and posteriorly by the roof of coronary sinus (CS) ostium. The incidence of atrioventricular (AV) conduction injury at different sites was as follows: 3 of 6 (50%) at Site 2, 4 of 13 (30.8%) at RMS, 7 of 34 (20.6%) at Site 3, and 3 of 46 (6.5%) at Site 1. Even if ablation was performed at the atrial side of the para-hisian region, the right bundle branch block (RBBB) was caused in 6 patients (5%).ConclusionAblation via IVC or SVC was comparative for para-hisian APs, but not for the noncoronary cusp (NCC) approach. The AV conduction injury risk ranks as follows: Site 2 > RMS > Site 3 > Site 1. RBBB could be caused while ablating at the atrial side, which could further demonstrate the His bundle longitudinal dissociation theory.

The seasonal dynamics and diagenesis of trace metals at two contrasting coastal sites were studied to determine the mechanism that drove the diffusive release of trace metals from sediments in the Changjiang Estuary. Porewater trace metal concentrations were 53.4–4829 nM for Zn, 11.0–344 nM for Cu, 7.75–221 nM for Cr, 2.71–61.1 nM for Co, 0.822–42.7 nM for Pb and 0.037–4.22 nM for Cd. The concentrations and profiles of trace metals in the porewater and solid phase displayed obvious regional and seasonal variations. This variation was mainly reflected in the surface layer and the depth of the suboxic and anoxic layers. Regionally, surface porewater trace metal concentrations in the seasonal hypoxic region were higher than those in the aerobic region due to changes in the redox conditions being beneficial to the release of trace metals. Seasonally, surface porewater trace metal concentrations decreased in summer compared to spring due to their removal by forming metal sulfides in summer. Solid profiles of the trace metals supported their dynamic variations in the porewater. The partition coefficient suggested that the formation of Fe/Mn (hydr)oxides was effective for the removal of trace metal in oxidizing condition, while the formation of sulfides was conducive to the removal of trace metals in reducing condition. The combination of porewater with solid phase data suggested that the dynamics of Cu, Zn, Cr and Co were mainly controlled by Fe and Mn diagenesis, the dynamics of Cd were affected by S cycling, and the dynamics of Pb were disturbed by anthropogenic inputs and benthic organism activities. Estimation of benthic fluxes indicated that sediments were an important source of trace metals in the water column. The contributions of trace metals by sediments to the water column of the Changjiang Estuary were only one order of magnitude lower than those by riverine fluxes.

Amino sugars (AS) were investigated to study the source, reactivity and bacterial contribution of organic matters (OM) in surface sediments of the East China Sea (ECS) both in summer and autumn in 2016, within and after the algae bloom, respectively. The content of AS was 0.48-7.23 mu mol/(g dw) with a higher concentration in nearshore than that in offshore area and lower concentration in summer than that in autumn, which on average made up 3.65 +/- 1.66% of TOC and 4.49 +/- 1.98% of TN in the ECS surface sediments. The low average ratio of glucosamine/galactosaminc (GlcN/GalN) (1.16 +/- 0.15) indicated a major bacterial source of AS pool of the investigated area. Higher GlcN/GaIN (1.30 +/- 0.15 in summer and 1.21 +/- 0.09 in autumn) and muramic acid (Mur) (8.8 +/- 3.8 nmol/(mg C) in summer and 20.5 +/- 10.3 nmol/(mg C) in autumn) and together with lower GIcN/Mur (29 +/- 8 in summer and 16 +/- 4 in autumn) content in nearshore than those in offshore area (GIcN/ Ga1N: 1.11 +/- 0.14 in summer and 1.09 +/- 0.13 in autumn; Mur: 5.2 +/- 1.7 nmol/(mg C) in summer and 10.4 +/- 5 nmol/(mg C) in autumn; GIcN/Mur: 36 +/- 9 in summer and 34 +/- 11 in autumn) indicated more plankton detritus and a more labile nature of OM, and also relatively higher fresh bacteria contribution to OM in nearshore area, which was consistent with the higher concentrations of Chl-a in corresponding surface water. The transformation of plankton to bacteria source of OM from summer to autumn was revealed by the increased total hydrolysable amino sugars (THAS) and Mur concentration, C- and N-normalized yield of THAS, and also the decreased ratios of GIcN/GalN and GlcN/Mur in sediments in autumn. The correlation between Mur in sediments and Chl-a in surface water suggested that the real-time settling plankton detritus was one of the major food sources for benthic bacteria in summer but contributed little in autumn. Based on Mur, the relatively fresh bacteria OM contribution to TOC were 13.1% in summer and 28.5% in autumn. In summary, the composition of AS in the ECS surface sediments showed a major bacteria origin of OM and the bioavailability decreased from nearshore to offshore and also from summer to autumn. As the algae bloom decline, the flux of plankton detritus decreased and the OM source transformed from plankton to bacteria.

Background While the left sinus of Valsalva (LSV) is a frequent origin of ventricular arrhythmias (VAs). Uncommonly, VAs with right bundle branch block (RBBB) morphology may be successfully terminated from the LSV. Objective We aimed to investigate the electrocardiographic and electrophysiologic characteristics of VAs with RBBB which were successfully eliminated from the LSV. Methods We identified patients with VAs successfully ablated from the LSV from January 2014 to December 2017 and compared electrophysiologic characteristics and ablation sites of those VAs with RBBB versus a control group of patients with left bundle branch block morphology. Results We identified 18 patients with RBBB and predominant "R" waves in the precordial leads. In 12 (66.7%) patients, a small "s" wave in lead V2 and positive "R" in the remaining pericardial leads could be seen. Overall, a single "V" potential was seen in 72.2% of patients in the study group, while discrete potentials were recorded in 80% of the patients in the control group. The majority (88.9%) of the VAs could only be terminated at the nadir of the LSV in the study group. After mean follow-up of 33 ± 14 months, 93.8% and 92% were free of VAs after initial ablation in study and control group, respectively (P = 0.99). Conclusion Some VAs with predominant monophasic "R" wave in precordial leads could be terminated from LSV, especially a small "s" wave in lead V2 was recorded. The nadir of LSV is highly successful for RBBB VAs and single electrogram was recorded at the target for most of the cases.

BACKGROUND Dextrocardia with situs inversus is a rare cardiac positional anomaly. Catheter ablation procedures performed in this set of patients have not been sufficiently reported. METHODS A total of 10 patients with dextrocardia and situs inversus who received catheter ablation for supraventricular tachycardia (SVT) were included from a cohort of over 20 000 cases of catheter ablation for SVT in three centers from 2005 to 2016. All patients underwent electrophysiologic study and catheter ablation of SVT. Ablation targets were selected based on different tachycardia mechanisms with the primary endpoint of noninduction of tachycardia. RESULTS The average age was 32.4 ± 5.6 years. Congenitally corrected transposition of great arteries (TGA) with situs inversus and D-looping of the ventricles and aorta (congenitally corrected TGA {I,D,D}) was found in four patients, while the other six patients exhibited mirror-image dextrocardia {I,L,L}. The mechanisms of SVT were atrioventricular nodal reentrant tachycardia in four patients, atrioventricular reentrant tachycardia in three, typical atrial flutter in one, intra-atrial reentrant tachycardia in one, and focal atrial tachycardia in one. Immediate procedural success was achieved in 9 out of 10 patients with no procedural complications. During a follow-up period of 6.3 ± 3.5 years on average, all patients remained free from recurrent tachycardia. CONCLUSIONS For patients with dextrocardia and situs inversus, catheter ablation of SVT is safe and feasible. Differences in catheter maneuver and fluroscopy projection, along with difficulties in distorted anatomy are major obstacles for successful ablation.

For the multi-sample equal covariance function (ECF) testing problem, Zhang (Analysis of variance for functional data, CRC Press, Boca Raton, 2013) proposed an $$L^{2}$$-norm-based test. However, its asymptotic power and finite sample performance have not been studied. In this paper, its asymptotic power is investigated under some mild conditions. It is shown that the $$L^2$$-norm-based test is root-n consistent. In addition, intensive simulation studies are conducted to evaluate its finite sample performance against several existing competitors. In particular, they demonstrate that in terms of size control and power, the $$L^{2}$$-norm-based test outperforms the dimension-reduction-based tests proposed by Panaretos et al. (J Am Stat Assoc 105(490):670–682, 2010) and Fremdt et al. (Scand J Stat 40(1):138–152, 2013), respectively, when functional data are less correlated or when the covariance function differences of functional data contain mainly high-frequency signals. Two real data applications are presented to illustrate the $$L^2$$-norm-based test.

In this article, we propose two new tests for the equality of the covariance functions of several functional populations, namely, a quasi-GPF test and a quasi-Fmax test whose test statistics are o...

Introduction: To assess the predictors of hemoptysis using second-generation cryoballoon (CB). Methods: Thirty patients with hemoptysis after second-generation CB ablation and 60 age-, gender-, and body mass index-matched controls were recruited. Anatomic parameters were obtained from preprocedural cardiac computed tomography (CT). Pulmonary vein isolation was performed with 28-mm balloon using single 3-minute freeze technique. Results: Clinical and procedural characteristics were similar between the groups. A shorter distance between left superior PV (LSPV) and left main bronchus (LMB) was associated with hemoptysis (7.8 +/- 4.3mmvs. 12.5 +/- 3.5 mm, P l 0.001), whereas no significant difference in the distance between right superior PV (RSPV) and right main bronchus (RMB) was found between groups (11.9 +/- 3.5 mm vs. 12.9 +/- 4.6 mm, P = 0.089). Additionally, the mean thickness of the connective tissue interposed between RSPV and RMB was significantly thicker than that between LSPV and LMB in both groups (both P l 0.001). A stepwise logistic multivariate analysis identified only the LMB-LSPV distance as an independent predictor of hemoptysis (odd ratio [OR] 2.676; 95% CI 1.121-4.843, P l 0.001). A cutoff value l= 9.5 mm predicted hemoptysis after CB ablation with 93.8% sensitivity and 75.0% specificity. Conclusion: Hemoptysis is a relatively rare event following second-generation CB ablation. The bronchi location obtained from CT aids in identifying high-risk population for the complication.

Microbial processes during the degradation and transformation of marine organic matter (OM) are thought to play an important role in controlling the strength and efficiency of carbon export and preservation in the ocean. However, the detailed relationship between the diagenetic states of OM and microbial activity and community structures remains poorly understood. In this study, particulate amino acids (PAAs), stable carbon and nitrogen isotopic signatures, heterotrophic bacterial abundance (HBA), bacterial community structure and extracellular hydrolytic enzyme activity (EEA) in particulate OM (POM) were investigated in Jiaozhou Bay (JZB), China, with the aim of investigating bacterial degradation and adaption in response to different sources and reactivity of POM in the coastal environment. The results showed that POM from different sources had distinct PAA compositions, diagenetic states, and bacterial features, such as particle attached HBA, EEA and community structure. High PAA concentrations but low contribution of bacterial carbon to particulate organic carbon (POC) and diagenetic alteration of POM were observed in regions with high in situ marine production, where high Chl-a and autochthonous δ13C and δ15N signatures were observed. In addition, high HBA and D-amino acid (D-AA) concentrations in POM were also found in the same regions, which indicated that fresh POM also induced rapid bacterial growth and reproduction. However, the lowest D-AA proportion to PAA (mol% D-AA) in those regions still indicated a more obvious supply of AAs from marine sources, which was consistent with the low bacterial carbon contribution to POC and fresh states of POM. In contrast, POM in low primary production regions was highly degraded by bacteria, as reflected by an enrichment in D-AAs and high bacterial contribution. However, high EEA probably driven by the priming effect occurred in regions where fresh planktonic POM was mixed with terrigenous POM. High relative abundances of Flavobacteriia, Alphaproteobacteria and Gammaproteobacteria were observed in fresh planktonic, terrestrial and planktonic mixture and highly degraded POM, respectively, indicating a possible bacterial adaptation strategy to their available OM. Our study has important implications for bacteria–POM interactions and provides insight into the role of bacteria in the degradation and transformation of POM of different sources in coastal systems.

ObjectiveThe study sought to evaluate the procedural and biophysical factors related to acute pulmonary vein isolation (PVI) guided by real-time pulmonary vein (PV) potential recordings. MethodsA total of 180 consecutive patients with drug-resistant atrial fibrillation (AF) undergoing CB2 (second-generation version of cryoballoon) ablation were enrolled. Real-time monitoring of PV potentials was obtained using an inner lumen spiral mapping catheter. ResultsAcute isolation was achieved in all PVs without touch-up ablation. Real-time assessment of PV disconnection was possible in 611 of 711 (85.9%) PVs. A total of 617 (86.8%) PVs were isolated during the initial freeze. Longer time cycle integration (TCI) (TTI * freeze cycle, TCI) (254.6112.8 seconds vs 74.1 +/- 59.7 seconds, Pl0.001), time to isolation (TTI) (94.3 +/- 34.0 seconds vs 46.3 +/- 26.2 seconds, Pl0.001), higher nadir temperature (-45.5 +/- 5.3 degrees C vs -50.4 +/- 5.5 degrees C, Pl0.001), longer time to -40 degrees C (77.3 +/- 22.7 seconds vs 55.7 +/- 23.2 seconds, Pl0.001), faster interval rewarming time at 0 degrees C (9.4 +/- 4.3 seconds vs 12.4 +/- 4.9 seconds, P=0.008), and total balloon rewarming time (38.1 +/- 11.6 seconds vs 47.7 +/- 14.0 seconds, P=0.003) were observed in PVs with acute reconduction. TTI 65 seconds predicted absence of acute reconnection with 84.2% sensitivity and 75.7% specificity, whereas TCI 119 seconds presented 94.7% sensitivity and 80.2% specificity. At a mean follow-up of 4.7 +/- 1.4 months, 82.2% of patients were free of AF. None of those with PV reconnections suffered from AF recurrences. ConclusionsThe ablation using CB2 is effective in achieving acute PVI. Real-time assessment of PVI could be achieved during CB application in 86% of PVs. The incidence of spontaneous PV reconnection is very low, observed in just 3% of isolated PVs. TTI 65 seconds and TCI 119 seconds predicted absence of acute PV reconnection. Although they may identify effective cryoapplications in the acute phase, their performance still needs to be verified in the long term.

Aims We aimed to examine the electrocardiographic and electrophysiologic characteristics of anterograde-conducting decremental accessory pathways (DAP) and to identify surrogate criteria to distinguish short atrioventricular (SAV) DAP from atriofascicular (AF) AP and long atrioventricular (LAV) DAP. Methods and results We identified all patients with DAPs and analysed electrocardiographic and electrophysiologic characteristics. Distal insertion sites were examined using existing criteria, including V-H interval, ventricular activation at the right ventricular apex, and around tricuspid annulus during antidromic atrioventricular re-entrant tachycardia (A-AVRT) or complete pre-excitation and evaluated the AV node-like properties according to the response to adenosine and radiofrequency ablation. Out of 45 patients with DAPs, 28 (62.2%) had SAV-DAP (13 with definite AF-AP, 2 with definite LAV-DAP, 2 indeterminate). In all, 50% of SAV-DAPs and 53.3% of AF-AP/LAV-DAPs had 'rS' pattern in lead III. Longer QRS duration (159.9 ± 17.4 ms vs. 139.2 ± 14.3 ms, P

This paper gives simple and intuitive derivations of three equivalent forms of a distribution-free and unbiased estimator of the squared covariance matrix Σ 2 . Particularly, computationally efficient forms of the unbiased estimators of Σ 2 and its trace are derived from the computationally intensive U-statistic forms.

In recent years, high-dimensional data has become increasingly prevalent with rapid development of data collecting technologies. Much work has been done for hypothesis testing on mean vectors, especially for high-dimensional two-sample problems. Rather than considering a specific problem, we are interested in a general linear hypothesis testing problem on mean vectors of several populations, which includes many existing hypotheses about mean vectors as its special cases. We propose a test statistic based on a linear combination of U-statistics which can be quickly calculated without using computationally intensive U-statistics. Asymptotic normality and power of our test are derived under mild conditions without requiring an explicit relation between the data dimension and the sample size. Our test is applicable to non-normal multi-sample high-dimensional data without assuming a common covariance matrix among different samples. It also works well even when different samples follow different distributions, provided that some moment conditions are satisfied. A simple, computationally-efficient, and ratio-consistent estimator of the unknown variance of our test statistic is also provided which is not based on U-statistic calculations. Simulation studies and a real data example are presented to demonstrate the good performance of our test.

Aims We sought to investigate the clinical, electrocardiographic, and electrophysiological characteristics of left upper septal fascicular ventricular tachycardia (LUS-VT). Methods and results Eleven consecutive patients with LUS-VT were identified among 196 patients with left fascicular ventricular tachycardia (VT). Clinical VTs presented as paroxysmal in 8 patients and incessant in 3 patients. Six patients had previous left posterior fascicular VT ablation history. All VTs had narrow QRS complexes with QRS duration of 101.1 ± 9.2 ms. The frontal QRS axis was normal or right deviation. Precordial morphology was either right bundle branch block type or similar to that of sinus rhythm. A retrograde His with H-V interval of 21.9 ± 7.2 ms was recorded during VT. The earliest Purkinje potential (PP) to QRS interval during VT averaged 35.7 ± 4.5 ms. Clear diastolic potentials (DPs) with high frequency and low amplitude were found in only one patient. Ten patients were managed successfully by 11 ablation sessions, and 1 patient declined ablation. Successful targets at the left upper septum were sites with the earliest PP (9 cases) or with DP (1 case) during VT. After ablation, 2 cases (10%) developed new left anterior hemiblock or incomplete left bundle branch block. No VT recurred during a median follow-up period of 3.2 (range 1.0-12.7) years. Conclusion LUS-VT presented as narrow QRS complex tachycardia. Some LUS-VTs occurred after ablation targeting left posterior fascicular VT. The VTs can be managed successfully by focal ablation at the left upper septum with a mild risk of fascicular injury.

The logging evaluations of tuffaceous sandstone reservoirs are always difficult problems. The existence of tuff results in the great variations in reservoir pore structures, and the associated physical properties, which greatly influence the formation parameters. Therefore, the effects of tuff on saturation models cannot be ignored. This study took the tuffaceous sandstone reservoirs in the X depression of the Hailar-Tamtsag Basin as an example. Based on the differences of the response characteristics between the tuff and shale, the component content was calculated using a method which combined a bacterial foraging algorithm and a particle swarm optimization algorithm. The experimental data of the cation exchange capacity (CEC) proved that the tuff had conductivity. Then, the resistivity of the tuff was obtained using the relationship between the CEC and the resistivity, which was then used to calculate the saturation. Finally, a new method was proposed to calculate the saturation of a tuffaceous sandstone reservoir, and was referred to as a CEC ratio method. The calculation results of this method were found to have a good application effect.

Testing the equality of two means is a fundamental inference problem. For high-dimensional data, the Hotelling’s T2-test either performs poorly or becomes inapplicable. Several modifications have been proposed to address this issue. However, most of them are based on asymptotic normality of the null distributions of their test statistics which inevitably requires strong assumptions on the covariance. We study this problem thoroughly and propose an L2-norm based test that works under mild conditions and even when there are fewer observations than the dimension. Specially, to cope with general nonnormality of the null distribution we employ the Welch–Satterthwaite χ2-approximation. We derive a sharp upper bound on the approximation error and use it to justify that χ2-approximation is preferred to normal approximation. Simple ratio-consistent estimators for the parameters in the χ2-approximation are given. Importantly, our test can cope with singularity or near singularity of the covariance which is commonly seen in high dimensions and is the main cause of nonnormality. The power of the proposed test is also investigated. Extensive simulation studies and an application show that our test is at least comparable to and often outperforms several competitors in terms of size control, and the powers are comparable when their sizes are. Supplementary materials for this article are available online.

The particulate amino sugars (PAS), organic carbon (POC) and nitrogen (PN), the chlorophyll a (Chl-a), and the heterotrophic bacterial cell count (HBC) in the Yangtze River Estuary (YRE) were determined to study the biological source, bioavailability and bacterial contribution of particulate organic matter (POM) under the influence of algal bloom during the spring and autumn of 2017. The contents of PAS were 2.6–69.6 nmol/(mg dw) and made up 5.29 ± 2.55% of POC and 5.39 ± 2.77% of PN. The strong positive correlations between Chl-a and POC, PN and PAS and their similar distributions indicated that phytoplankton was a major source of POM and PAS in the YRE. When algal blooms occurred, the high ratios of glucosamine to galactosamine (GlcN/GalN) (~10.9) and the high carbon and nitrogen normalized yields of PAS (%PAS-POC and %PAS-PN, respectively) clearly indicated the planktonic (especially zooplankton) source of POM, although the high muramic acid (Mur) contents implying high contents of fresh bacterial organic matter (OM) were also found. Additionally, the high proportion of fresh plankton- and bacterial-derived OM indicated that the POM was more labile when algal bloom occurred. In contrast, when the primary production was low, the lower %PAS-POC and GlcN/GalN ratios (

As important components of marine organic matters especially of organic nitrogen, amino acids play an important role in organic matter cycles owing to their lability. The concentration, composition, and distribution of amino acids have been widely used to indicate the degradation state of organic matters in particulates and sediments of marine. Here, the distribution, influencing factors of amino acids and their role in indicating degradation of organic matters were systematically summarized. Gly, Glu, Ala, and Asp were the major components of amino acids in marine particulates and sediments. The contents of amino acids in the particles and sediments showed a decreasing tendency from the coastal waters to the open sea, and adecreased with the water depth. The lower value of %AA-C/TOC, %AA-N/TN and degradation index (DI) based on changes in the composition of amino acids indicated the higher degradation degrees of organic matters. The reactivity index (RI) and ratios of D-AA and L-AA (D/L) based on non-protein amino acids and D-AA were used to indicate the degradation of organic matter according to the bacterial transformation of amino acids, in which RI value closer to 0, higher D/L, and lower ratios of protein amino acids to non-protein amino acids (Asp/β-Ala and Glu/γ-Aba) indicated the higher degree of degradation in organic matters. The migration and transformation of amino acid were mainly affected by dissolved oxygen, nutrient concentrations, sources of organic matter, depositional environments and microbial activities. Further studies should focus on the synergistic effects of particles and sediments, and also the effects and the specific regulatory roles of microorganisms on amino acids.氨基酸是海洋有机质尤其是有机氮的重要组分,其地球化学行为活跃,在海洋有机质生物地球化学循环过程中起着重要作用.氨基酸的含量、组成和分布等信息可有效指示有机质的降解状态.本研究系统总结了海洋颗粒物/沉积物中氨基酸的分布特征及影响因素,以及氨基酸对有机质降解程度的指示作用.海洋颗粒物/沉积物氨基酸的主要成分为甘氨酸 (Gly)、谷氨酸(Glu)、丙氨酸(Ala)和天冬氨酸(Asp),其含量从近岸到大洋逐渐降低,并随深度增加呈下降趋势.氨基酸的碳、氮归一化产率(%AA-C/TOC,%AA-N/TN)以及基于氨基酸组成的降解因子(DI)越低,表明有机质的降解程度越高.基于非蛋白质氨基酸以及D型氨基酸含量与组成的活性因子(RI)和D型氨基酸与L型氨基酸比值(D/L)等指标可以根据细菌对氨基酸的转化作用来指示有机质的降解程度,其中RI值越接近于0,D/L值越高,蛋白质与非蛋白质氨基酸的比值Asp/β-Ala和Glu/γ-Aba(氨基丁酸)越小,均表明有机质受到微生物的降解和转化程度越高.颗粒物/沉积物中氨基酸的迁移转化过程主要受到溶解氧、营养盐水平、有机质来源、沉积环境以及微生物转化等因素的影响.今后应加强颗粒物和沉积物之间的协同效应以及微生物对氨基酸的影响与具体调控机理研究.

We aimed to investigate the characteristics of focal atrial tachycardias (ATs) arising from the pulmonary veins (PVs), as well as the safety and long-term efficacy of cryoballoon (CB) versus radiofrequency (RF) ablation in this population. Eighty-three patients with ATs arising from PVs from a consecutive series of 487 patients who underwent CB and RF ablation were retrospectively reviewed. Patients who had a prior history of atrial fibrillation (AF) were excluded. The AT origin was confirmed during the conventional electrophysiological study and activation mapping. The ablation approach was at the discretion of the operators. Thirty-five patients were managed with focal ablation, 25 were ablated with unilateral PV isolation (PVI), and the remaining 23 were performed with CB ablation. All procedures were successfully ablated. There was no significant difference in procedure time between CB group and RF focal group (43.7 ± 11.8 min vs. 45.8 ± 11.2 min, P = 0.121), whereas the fluoroscopy time in CB group was longer than in RF PVI group (10.1 ± 2.5 min vs. 8.4 ± 2.8 min, P

INTRODUCTION The procedural findings and clinical outcome of second-generation cryoballoon (CB2) ablation in patients with variant pulmonary vein (PV) anatomy have not been fully investigated. METHODS A total of 424 consecutive patients who underwent PV isolation with CB2 were included. Computed tomographic (CT) scan was performed in all patients before the procedure. The study population was divided into common PV, accessory PV, and nonvariant PV groups according to the CT scan. Procedural findings and clinical outcome between the three groups were compared. RESULTS Variant PV anatomy was observed in 118 of 424 (27.8%) patients. PV isolation was successfully achieved in all patients in three groups with low rates of need for touch-up ablation (P = 0.974). Total procedure time was longer in the accessory PV group compared with nonvariant PV group (53.7 ± 12.9 vs 49.5 ± 8.8 minutes; P

Background Catheter ablation of ventricular arrhythmias (VAs) originating from the para-Hisian region could be challenging because of a potential damage to atrioventricular conduction system. Objective The purpose of this study was to evaluate the safety and efficacy of catheter ablation of VAs originating from the para-Hisian region via a systematic direct approach from aortic sinus cusps (ASCs). Methods Twenty-one consecutive patients with VAs with para-Hisian origin were included. Electrophysiological mapping of the entire right ventricle was initially performed, and then retrograde ASC mapping was performed when the earliest ventricular activation was recorded in the His bundle region. Ablation was preferentially performed within ASCs in all patients. Results Radiofrequency energy delivery resulted in the elimination of VAs in 17 of 21 patients (81%). In the remaining 4 patients, radiofrequency application was initiated at the target site of the right ventricular septum around the His bundle region and clinical VAs were finally successfully eliminated without junctional rhythm in 2 of 4 patients. During a mean follow-up of 34.8 ± 11.3 months, 1 of the 19 acute successful patients had VA recurrence. No procedure-related complications occurred during ablation or follow-up. Conclusion Catheter ablation of VAs originating from the para-Hisian region via a direct approach from ASCs may be safe and effective in most unselected patients.

Background Multiple intercostal recordings were supposed to get a more comprehensive view of the depolarization vector of the outflow tract ventricular arrhythmia (OT-VA), which may help to identify the OT-VA more accurately. This study was undertaken to develop a more accurate electrocardiogram (ECG) criterion for differentiating between left and right OT-VA origins. Methods We studied OT-VA with a left bundle branch block pattern and inferior axis QRS morphology in 47 patients with successful catheter ablation in the right ventricular OT (RVOT; n = 37) or aortic coronary cusp (ACC; n = 10). Superior and inferior precordial leads were taken together with the routine 12-lead ECG. The ECG during the OT-VA and during sinus beats were analyzed. Transition ratio, transition zone (TZ) index, R/S amplitude ratio, and R-wave duration ratio were measured in the regular, superior, and inferior precordial leads. Results The combined TZ index, TZ index inferior was significantly smaller, while the V2 inferior transition ratio was significantly larger for ACC origins than RVOT origins (P < 0.05). The area under the curve for the combined TZ index by a receiver operating characteristic analysis was 0.974, which was significantly larger than other parameters. A cutoff value ≤0.25 predicted an ACC origin with 94% sensitivity and 100% specificity. This advantage of the parameter over others also held true for a subanalysis of OT-VAs with a lead V3 precordial transition or TZ index = 0. Conclusions The combined TZ index outperformed other ECG criteria to differentiate left from right OT-VA origins.

Background Cryoballoon ablation is an alternative for the treatment of atrial fibrillation (AF). We assess the relationship among pulmonary vein (PV) electrophysiology, balloon temperature, and persistent PV isolation (PVI), and report procedural properties, safety, and efficacy of this technique in a Chinese center for the first time. Methods A total of 70 patients with paroxysmal (n = 57) and persistent (n = 13) AF were consecutively enrolled. PVI was performed with cryoballoon catheter. Real-time recording of dissociation of PV potentials was attempted using a circumferential mapping catheter. Results Successful PVI was achieved in 274 of 282 (97.2%) PVs. Procedural duration was 115.2 ± 24.8 minutes and fluoroscopy time was 29.6 ± 8.9 minutes. Real-time PV potential recording was achieved in 232 (84.3%) PVs. Regarding time to isolation, a cut-off value of less than 60 seconds was predictive of persistent PVI with a sensitivity of 0.76 and specificity of 0.82 (area under curve = 0.835; P < 0.0001). The nadir balloon temperature was significantly lower in PVs without early reconduction (–46.3 ± 0.5°C vs –40.2 ± 1.3°C, P < 0.0001). However, there was an insignificant trend that the balloon temperature at isolation was higher in PVs without reconduction (–33.9 ± 0.7°C vs –36.4 ± 2.0°C, P = 0.14). The overall complication rate was 5.7%. After a median follow-up of 6.5 (range 3.2–14.9) months, 76% of patients were free of AF recurrence with a blanking period of 3 months. Conclusions Real-time PV potentials can be recorded in most PVs. The time to isolation is predictive of the persistency of PVI. The nadir balloon temperature, not the balloon temperature at isolation, is significantly lower in PVs without reconduction.

INTRODUCTION The "Crosstalk" technique: if pulmonary vein isolation (PVI) of the superior one is not achieved due to a gap in the inferior part, it could be done during inferior vein cryoablation. This maneuver minimizes the total energy delivery time and number of lesions. We aimed to correlate the likelihood of crosstalk phenomenon with certain anatomic characteristics. METHODS A total of 676 patients undergoing a first ablation procedure for paroxysmal or persistent atrial fibrillation (470 first-generation cryoballoon [CB] and 206 second-generation CB) between June 2014 and December 2016 were included. RESULTS "Crosstalk" phenomenon occurred in 32 patients (18 first-generation CB, 14 second-generation CB). Compared to 54 control patients without crosstalk, the angle between left superior pulmonary vein (LSPV) and left atrial (LA) roof-plane, left pulmonary common ostia were significant parameters associated with crosstalk (odds ratio [OR] = 1.20, ±95% confidence interval [CI]: 1.11-1.31, P

Accessory Pathway Target in Ebstein's Anomaly Introduction Knowledge about local electrogram and atrial/ventricular electrogram amplitude ratio (A/V ratio) at the true atrioventricular ring for successful ablation of accessory pathways (APs) in patients with Ebstein's anomaly is limited. Methods Twenty-two adults with Ebstein's anomaly and APs were managed by 24 sessions of radiofrequency catheter ablation (RFCA). A right atrial/ventricular angiogram with or without 3-dimensional electroanatomic mapping was performed to delineate the true atrioventricular ring and atrialized right ventricle (ARV). Electrograms of successful targets were analyzed. For each right-sided AP target, 2 AP targets matched by location and conduction property from normal hearts were selected as controls, and their A/V ratios were compared. Results In 32 right-sided APs of all 22 patients, local ventricular activation at successful site presented as normal electrogram in 14, fractionated ventricular electrogram (FVE) in 16, and double ventricular potentials in 2. The bipolar voltage of ARV was markedly lower than in normal hearts. The A/V ratio at the successful target was significantly higher in APs with FVE than in control (1.64 ± 1.34 vs. 0.47 ± 0.19, P < 0.01), and was similar in APs with normal ventricular electrogram and in the control (0.38 ± 0.15 vs. 0.46 ± 0.15, P = 0.1726). The A/V ratio at the successful target with double ventricular potentials (after surgical correction) was 0.30 ± 0.20. All APs were successfully ablated without complications. Conclusions In patients with Ebstein's anomaly, FVE was found in 50% of the successful targets of APs. High A/V ratio at successful sites with FVE and normal A/V ratio at targets with normal ventricular electrogram can facilitate target recognition and ablation.

We study nonlinear regression models when the response and predictors are unobservable and distorted in a multiplicative fashion by additive models of some observed confounding variables. After approximating the additive nonparametric components via polynomial splines and calibrating the error-prone response and predictors, we develop a semi-parametric profile nonlinear least squares procedure to estimate the parameters of interest. We show that the resulting estimators are asymptotically normal. We further suggest an empirical likelihood-based statistic for statistical inference to improve the accuracy of the associated normal approximation with the aim to avoid estimating the asymptotic covariance matrix that involves infinite-dimensional nuisance of additive distorting functions. We also show that the empirical likelihood statistic is asymptotically chi-squared. Moreover, a test procedure is proposed to check whether the parametric model is adequate or not under this distorted measurement error setting. A wild bootstrap procedure is suggested to compute p -values. Simulation studies are conducted to examine the performance of the proposed procedures. The methods are applied to analyze real data from a low birth infants weight for an illustration.

Focal atrial tachycardias (ATs) from the parahisian region can be successfully ablated from the right atrial septum (RAS), noncoronary cusp (NCC), and right middle septum (RMS). The optimal mapping and ablation strategy for ATs from these sites remains unclear.The purpose of this study was to investigate the electrophysiologic characteristics and optimal ablation sites of parahisian ATs from the RAS, RMS, and NCC.A total of 362 patients with ATs undergoing radiofrequency catheter ablation of ATs were included. A detailed examination including ECG analysis and electrophysiologic study was performed.Overall, 91 patients had a parahisian site of AT origin, and ablation was successful in 86 (94.5%). ATs were successfully eliminated from the RAS in 23, RMS in 19, and NCC in 44. The earliest "A" potential was recorded at the distal His catheter in 69.4% of NCC ATs vs the proximal His catheter in 83.3% of RAS ATs and 86.7% of RMS ATs. Mean timing of the "A" potential of RMS ATs recorded at the His-bundle catheter was -18.25 ± 7.20 ms, which was later than ATs from the RAS (-24.59 ± 8.73 ms) or NCC (-27.08 ± 5.63 ms). For ATs originating from the RAS and RMS, an A/V ratio1.22 predicted safe and successful ablation (sensitivity 88.4%, specificity 91.7%).For parahisian ATs, activation sequence and timing of the "A" on the His catheter can provide clues for the origin of ATs. When ablating at the RAS and RMS, an A/V ratio1.22 identified safe and effective ablation sites.

Objective The present study aimed to retrospectively investigate long-term clinical outcomes of patients undergoing catheter ablation of left posterior fascicular ventricular tachycardia (LPF-VT) with the development of left posterior fascicular block (LPF block) and characteristics of repeat procedures. Methods and results A total of 195 patients (mean age 29.76±1.03years, 16.4% females) who underwent catheter ablation for LPF-VT were consecutively enrolled. The earliest ventricular potential with a single fused Purkinje potential (PP) during VT and the PP located in the inferior-apical or mid-apical septum during SR were targeted for linear ablation. The endpoint of the procedure was noninducible VT and development of new-onset LPF block. Follow-up with clinic visits or telephonic interviews, electrocardiogram (ECG), or Holter monitoring was performed after the procedure. With a median follow-up of 85 (18,181) months, 20 patients were censored and 152 of 175 (86.86%) patients had long-term freedom from VT after a single procedure. No statistical difference in the outcome of catheter ablation of LPF-VT was found between inducible and non-inducible groups ( P =0.89). Twenty-three patients exhibited recurrent LPF-VT. Seven of 23 patients developed new-onset left upper septal ventricular tachycardia that was successfully ablated. All the patients undergoing repeat procedures had freedom from VT. No procedural complications occurred. Conclusions Ablation of LPF-VT using the development of LPF block as the endpoint is associated with a high procedural success rate. No difference in freedom from LPF-VT was found between inducible and non-inducible patients. New-onset LPF block recovery and non-early PP-QRS interval can be the predictors of LPF-VT repeat procedure.

Gas-bearing volcanic reservoirs have been found in the deep Songliao Basin, China. Choosing proper interpretation parameters for log evaluation is difficult due to complicated mineral compositions and variable mineral contents. Based on the QAPF classification scheme given by IUGS, we propose a method to determine the mineral contents of volcanic rocks using log data and a genetic algorithm. According to the QAPF scheme, minerals in volcanic rocks are divided into five groups: Q(quartz), A (Alkaline feldspar), P (plagioclase), M (mafic) and F (feldspathoid). We propose a model called QAPM including porosity for the volumetric analysis of reservoirs. The log response equations for density, apparent neutron porosity, transit time, gamma ray and volume photoelectrical cross section index were first established with the mineral parameters obtained from the Schlumberger handbook of log mineral parameters. Then the volumes of the four minerals in the matrix were calculated using the genetic algorithm (GA). The calculated porosity, based on the interpretation parameters, can be compared with core porosity, and the rock names given in the paper based on QAPF classification according to the four mineral contents are compatible with those from the chemical analysis of the core samples.

Multiple intercostal recordings were supposed to get a more comprehensive view of the depolarization vector of the outflow tract ventricular arrhythmia (OT-VA), which may help to identify the OT-VA more accurately. This study was undertaken to develop a more accurate electrocardiogram (ECG) criterion for differentiating between left and right OT-VA origins.We studied OT-VA with a left bundle branch block pattern and inferior axis QRS morphology in 47 patients with successful catheter ablation in the right ventricular OT (RVOT; n = 37) or aortic coronary cusp (ACC; n = 10). Superior and inferior precordial leads were taken together with the routine 12-lead ECG. The ECG during the OT-VA and during sinus beats were analyzed. Transition ratio, transition zone (TZ) index, R/S amplitude ratio, and R-wave duration ratio were measured in the regular, superior, and inferior precordial leads.The combined TZ index, TZ index inferior was significantly smaller, while the V2 inferior transition ratio was significantly larger for ACC origins than RVOT origins (P0.05). The area under the curve for the combined TZ index by a receiver operating characteristic analysis was 0.974, which was significantly larger than other parameters. A cutoff value ≤0.25 predicted an ACC origin with 94% sensitivity and 100% specificity. This advantage of the parameter over others also held true for a subanalysis of OT-VAs with a lead V3 precordial transition or TZ index = 0.The combined TZ index outperformed other ECG criteria to differentiate left from right OT-VA origins.