不同类型导管用于大鼠改良Yaksh法鞘内置管的比较

目的比较国内常用的不同类型导管用于大鼠Yaksh法鞘内置管的差异,探讨理想的鞘内置管材料。方法80只SD雄性大鼠,随机分为A、B、C、D四组,测热痛缩腿反应潜伏期（TWL）基础值后分别按改良Yaksh法置入Microspinal、PE-0402,PE-0503和改良硬膜外导管。术后第1、2、3天评估运动功能,记录置管并发症情况。术后第3天取运动正常大鼠测TWL,行利多卡因试验验证导管是否在鞘内。显微镜下解剖所有大鼠观察脊髓。结果（1）A、B组脊髓损伤及并发症较C、D组少（P〈0.05）A与B、C与D组间差异不显著（P〉0.05）。四组动物利多卡因试验结果差异不显著（P〉0.05）。（2）运动协调能力A、B组恢复较C、D组理想（P〈0.05）,A与B、C与D之间差异不显著（P〉0.05）（3）四组动物TWL变化差异不显著（P〉0.05）。结论导管的外径、材料和形状可能对改良Yaksh法鞘内置管结果产生影响。Microspinal管及PE-0402管置管成功率高、并发症少,是大鼠鞘内置管较理想的材料。     

不同场强下IRE的肿瘤消融作用及对抗肿瘤免疫的影响

目的:探讨不同电场强度的不可逆电穿孔(IRE)对于肿瘤的消融效果以及其所引起的肿瘤免疫反应。方法:将B16黑色素瘤细胞接种于C57小鼠,制作黑色素瘤小鼠模型,应用不可逆电穿孔仪对肿瘤进行消融,通过测量肿瘤生长大小研究不同场强下的消融效果。通过CD4、CD8a免疫组化染色初步了解不同场强激发的免疫反应的强弱,从而选择最佳消融参数。结果:随着电场强度增加,肿瘤消融效果逐渐趋于理想,然而平板电极夹之间过高电场引发的热效应则不利于后续抗肿瘤免疫反应的激活。选择合适的电场,通过增加电击组数可以达到良好的治疗效果。结论:IRE对肿瘤的消融优势在于它能够很好的激活机体的抗肿瘤免疫反应,因此,选择合适的电场增加电击组数可以起到很好的抗肿瘤作用,具有很好的应用前景。     

Elemental variability in the coralline alga Lithophyllum yemenense as an archive of past climate in the Gulf of Aden (NW Indian Ocean)

This study presents the first algal thallus (skeleton) archive of Asian monsoon strength and Red Sea influence in the Gulf of Aden. Mg/Ca, Li/Ca, and Ba/Ca were measured in Lithophyllum yemenense from Balhaf (Gulf of Aden) using laser ablation inductively coupled plasma mass spectrometry, and Mg/Ca ratio oscillation was used to reconstruct the chronology (34 y). Oscillations of element rates corresponding to the algal growth between 1974 and 2008 were compared with recorded climate and oceanographic variability. During this period, sea surface temperatures (SST) in Balhaf recorded a warming trend of 0.55°C, corresponding to an increase in Mg and Li content in the algal thallus of 2.1 mol‐% and 1.87 μmol‐%, respectively. Lithophyllum yemenense recorded decadal SST variability by Li/Ca, and the influence of the Pacific El‐Niño Southern Oscillation on the NW Indian Ocean climate system by Ba/Ca. Additionally, algal Mg/Ca, Li/Ca, and Ba/Ca showed strong and significant correlations with All Indian Rainfall in the decadal range indicating that these proxies can be useful for tracking variability in the Indian monsoon system, possibly due to changes of the surface wind system, with deep water upwelling in summer, and a distinct seasonality.     

Anomalous growth of Staphylococcus epidermidis in the presence of Silastic and glycopeptide antibiotics

Abstract In the presence of supra-inhibitory concentrations of the glycopeptide antibiotics vancomycin and teicoplanin, biofilms of Staphylococcus epidermidis on a Silastic surface produce anomalous growwth. This takes the form of macroscopic, cohesive aggregates of cocci bound together with slime. This phenomenon was intermittent, independent of antibiotic concentrations between 20 and 50 μg ml⁻¹, occured more often with teicoplanin, and was found both with slime-negative strains.     

Acute and long-term outcomes of VT radiofrequency catheter ablation in patients with versus without an intramural septal substrate

IntroductionAim of this study was to evaluate efficacy and safety of ventricular tachycardia (VT) catheter ablation in patients with structural heart disease (SHD) in relation to the presence of an intramural septal substrate.MethodsConsecutive patients undergoing VT ablation between January 2019 and October 2020 were included. All patients were stratified based on the presence of relevant septal substrate and freedom from VT recurrences were analyzed.ResultsIn total, 199 consecutive patients (64.2 ± 13.0 years; 89% male; 55% ischemic cardiomyopathy (ICM)) undergoing VT ablation were included. 129/199 patients (65%) showed significant septal substrate (55/90 patients (61%) with non-ischemic cardiomyopathy (NICM) compared to 74/109 patients (68%) with ICM; p = 0.37). Acute procedural success with elimination of all inducible VTs was achieved in 66/70 patients (94%) without and in 103/129 patients (80%) with a septal substrate (p = 0.007). In the cohort including patients with a clinical FU, 15/60 patients (25%) without a septal substrate and 48/123 patients (39%) with a septal substrate experienced VT recurrence during a FU of 8.1 ± 5.9 months (p = 0.069).ConclusionPresence of septal VT substrate in patients with a structural heart disease or coronary artery disease is common. Acute success of VT catheter ablation was significantly higher and mid-term success tended to be higher in patients without a septal substrate.     

Unipolar and bipolar electrogram characteristics of recurrent cases of idiopathic ventricular arrhythmias undergoing repeat catheter ablation

IntroductionActivation mapping guided catheter ablation (CA) of ventricular arrhythmias (VAs) is limited in some cases when it is only relied on bipolar electrogram (EGM). We hypothesized that activation mapping with use of combined bipolar and unipolar EGM facilitates to identify the focal origin of VAs and results in reduction of recurrence rate of CA of VAs.MethodsWe analyzed the data of patients undergoing repeat ablations for idiopathic out-flow tract VAs. The EGM of the 1 st and 2 nd ablations were compared for earliest local activation time (LAT), presence of discrete potentials, and polarity reversal, unipolar potential morphology (QS or non-QS), potential amplitude and activation slope.ResultsThirty-seven patients were included. The Local activation time was significantly earlier in the 2nd ablation as compared to the 1st procedure (36.90 msec vs 31.85 msec, P < 0.01). The incidence of discrete potentials and polarity reversal were similar in both procedures (51% vs 57%, P = 0.8 and 62% in both the occasions, respectively). The unipolar voltage was similar in both occasions (6.94 mV vs 7.22 mV in repeat ablations, P = 0.7). The recurrence rate (5.7%) was significantly lower with routine use of combined unipolar and bipolar EGMs, as compared to the use of bipolar EGM alone (16.7%)ConclusionsUse of both bipolar and unipolar electrograms helps in better delineation of the sites of earliest activation for effective ablation of VAs. Use of unipolar electrograms in addition to bipolar electrograms is associated with lower long term recurrence rate.     

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO,C2, CN,and TiO Spectra Following Laser-induced Optical Breakdown

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement is used. Here we operate a Nd:YAG laser at a frequency of 10 Hz at the fundamental wavelength of 1,064 nm. The 14 nsec pulses with anenergy of 190 mJ/pulse are focused to a 50 µm spot size to generate a plasma from optical breakdown or laser ablation in air. The microplasma is imaged onto the entrance slit of a 0.6 m spectrometer, and spectra are recorded using an 1,800 grooves/mm grating an intensified linear diode array and optical multichannel analyzer (OMA) or an ICCD. Of interest are Stark-broadened atomic lines of the hydrogen Balmer series to infer electron density. We also elaborate on temperature measurements from diatomic emission spectra of aluminum monoxide (AlO), carbon (C₂), cyanogen (CN), and titanium monoxide (TiO).The experimental procedures include wavelength and sensitivity calibrations. Analysis of the recorded molecular spectra is accomplished by the fitting of data with tabulated line strengths. Furthermore, Monte-Carlo type simulations are performed to estimate the error margins. Time-resolved measurements are essential for the transient plasma commonly encountered in LIBS.