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ABSTRACT: This study evaluated the microbial contamination status of cold dishes consumed by residents of Jilin Province and investigated to determine the incidence of four pathogenic bacteria in cold dishes. A total of 300 samples of cold dishes, including meat, vegetable, and mixed products, were collected from three purchasing places: supermarkets, farmers' markets, and mobile vendors. Viable bacteria were isolated using conventional culture methods. After separation, a quick and easy PCR was used to detect Listeria monocytogenes, Staphylococcus aureus, enterotoxigenic Escherichia coli, and Salmonella. The results showed that the total number of microbial colonies in the vegetable samples exceeded the standard rate of 8% and the total number of microbial colonies in the meat and mixed samples did not exceed the standard. The total microbial colony count exceeded the standard in all three procurement sites, with the highest exceedance of 7.4% in the mobile vendor sites. The detection rates of enterotoxigenic E. coli, S. aureus, L. monocytogenes, and Salmonella, among the four pathogenic bacteria detected in all samples, were 4.3, 3.3, 3.0, and 1.0%, respectively. This study can be used to qualitatively assess the microbiological quality associated with cold dishes. It provides data to support the detection of possible food safety problems.

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Here, we propose a novel imaging method, which is called image scanning difference microscopy (ISDM), for superresolution imaging. In ISDM, we implement a detector array composed of 19 avalanche photodiodes (APD) rather than single-point detector in standard confocal microscopy for reconstructing superresolved images with higher signal-to-noise ratio (SNR). Combining with our former proposed fluorescence emission difference (FED) method, we have achieved a lateral resolution of 111 nm (∼λ/6) without the damage of image quality, the highest FED resolution to the best of our knowledge. With its simple setup and remarkable performance, we believe that ISDM can become a versatile observation tool in biology and other fundamental studies. LAY DESCRIPTION: Fluorescence emission difference (FED) microscopy is a really simple and generalisable superresolved fluorescence microscopy method based on PSF engineering and difference algorithm recently. Compared to stimulated-emission-depletion fluorescence microscopy (STED), FED don't need complicated system or precise alignment and polarisation, available for wide variety of dyes and has low photobleaching and phototoxicity for living cells. However, the distortion caused by negative value is one of the biggest obstacles to the further development of FED. In light of this, we propose a novel superresolution imaging method based on the FED method with parallel detection system, which is called image scanning difference microscopy (ISDM). Our method has achieved a significant breakthrough in FED, increasing the resolution further while reducing artefacts generated by negative values, which cannot be accomplished through combining other methods. In addition, ISDM does not require complex setup and optical alignment, long time imaging and imposing no constraint on dyes. Importantly, we realised a transverse resolution of ∼λ/6 (triple diffraction limit) with single wavelength, single incident path and low light intensity, which has never been achieved in any other far-field superresolution microscopy.

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Little is known about the worm-eating snakes of the genus Trachischium in the East Himalaya due to their secretive nature. To date, only T. monticola and T. tenuiceps are recorded from China, and the former species was recorded based on historical literature without vouchered information. In addition, a questionable record of T. guentheri in Tibet, China exists in literature, but no one has yet confirmed this distribution record. Here we confirm the distribution of T. guentheri in southeastern Tibet, China based on a newly collected specimen, and provide the first detailed description of T. monticola, including the first description of its hemipenial morphology, based on newly collected Tibetan specimens. Lastly, we provide a diagnostic key to the three Chinese species, and discuss the general distribution patterns of the genus in the Trans-Himalayan Region.

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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.

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BACKGROUND: The accessory pathway (AP) connecting the right atrial appendage (RAA) and the right ventricle (RV) is rare. OBJECTIVE: We sought to investigate the feature of the AP connecting the RAA and the RV and the efficacy of radiofrequency catheter ablation via the endocardial access. METHODS: We retrospectively analyzed 14 consecutive patients with 14 APs connecting the RAA and the RV managed by 15 procedures between January 2003 and December 2014. RESULTS: Ten patients presented as preexcitation during sinus rhythm. All APs had retrograde conduction. None had either antegrade or retrograde decremental conduction property. Ablation targeting the sites at the tricuspid annulus failed in all patients. They were successfully managed by ablating the atrial insertion sites with a median of 10.5 (range 5-28) radiofrequency applications. Electrograms at the successful target showed high amplitude atrial electrogram and low amplitude or no ventricular electrogram. The atrial insertion sites were at the floor of the RAA in 10 patients and inside the lower lobe of the RAA in the remaining 4 patients. The shortest distance between the successful target and the tricuspid annulus in the right anterior oblique projection was 19.7 ± 4.0 mm. There were no complications or recurrences during a median follow-up period of 4.3 (range 0.2-11.8) years. CONCLUSION: The APs connecting the RAA and the RV had typical conduction properties. The atrial insertion site favored the floor and the lower lobe of the RAA. Ablation targeting the atrial insertion sites was effective and safe, albeit multiple radiofrequency applications were needed.

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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.

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