Solving the overlapped absorbance profile in gas detection by Lorentz distribution solution based on direct absorption spectroscopy method.

A novel method of Lorentz distribution solution (LDS) from overlapped absorbance profile in time domain (incomplete absorbance profile in frequency domain) based on the direct absorption spectroscopy method (DAS) was experimentally demonstrated. It utilized the ratio of the integral in a certain interval on the lower horizontal axis of the Lorentzian profile to the integral in the entire interval on the horizontal axis has a certain relationship and can be expressed by a formula. This method effectively solves the difficulties of extracting gas concentration from incomplete absorbance profile. Formulation and detection procedure were presented, experiments were carried out to prove the method on the extraction of gas concentration from different overlapped absorbance profile and different concentration. Compared with the conventional DAS (C-DAS), the maximum relative errors on the concentration extraction are minimized from 25.55% to 2.64% at different concentration and absorbance profile. Meanwhile, the experimental results show that the obtained gas concentration by LDS presents a good linear relationship while those measured by C-DAS are significantly different.

Transverse mode locking of different frequency-degenerate families based on annular beam pumping.

Optical vortex arrays have been achieved in an end-pumped Nd:YVO4 laser pumped by an annular beam. Spontaneous transverse mode locking of Laguerre-Gaussian modes in different frequency-degenerate families has been obtained by merely adjusting the pump power. A maximum output power of 0.88 W and optical conversion efficiency of 13.6% are achieved for optical vortex arrays. Optical vortex arrays formed in different frequency-degenerate families of Laguerre-Gaussian modes can be actively controlled by the position of the axicon. This work provides a way to research transverse mode locking of Laguerre-Gaussian modes in different frequency-degenerate families based on annular beam pumping.

The predictive value of a concise classification of left atrial appendage morphology to thrombosis in non-valvular atrial fibrillation patients.

BACKGROUND: The complexity of left atrial appendage (LAA) in patients with nonvalvular atrial fibrillation (NVAF) is closely related to LAA thrombosis and stroke incidence. But the classification of LAA morphology is not uniform and controversial. HYPOTHESIS: This study divided the LAA into two categories according to the LAA morphology to investigate the risk of thrombosis related to the LAA structural complexity in NVAF patients. METHODS: A total of 336 NVAF patients were enrolled continuously in this study. The patients were divided into thrombosis group and non-thrombosis group according to whether the thrombus presence in LAA. Through computer LAA three-dimensional reconstruction, LAA morphology was divided into the complex type and simple type according to with or without the clearly lobulated structure judged by imaging experts. The relationship between LAA thrombosis and various potential risk factors was analyzed. RESULTS: A total of 19 potential risk factors for LAA thrombosis in NVAF patients were enrolled into statistical analysis. The coincidence rate of LAA morphology classification was 96.4% (324/336) between two imaging experts. Multivariate logistic regression analysis showed that complex LAA morphology (OR 4.168, 95% CI 1.871-9.288, P < .001) was associated with the presence of LAA thrombus, independently of other enrolled risks. CONCLUSIONS: It is a concise and reliable method to divide the LAA morphology into complex type and simple type according to whether with the clearly lobulated structure. The complex LAA is an independent risk factor for LAA thrombosis in NVAF patients.

Regulation of inward rectifier potassium current ionic channel remodeling by AT1 -Calcineurin-NFAT signaling pathway in stretch-induced hypertrophic atrial myocytes.

Previous studies have shown that the activation of angiotensin II receptor type I (AT1 ) is attributed to cardiac remodeling stimulated by increased heart load, and that it is followed by the activation of the calcineurin-nuclear factor of activated T-cells (NFAT) signaling pathway. Additionally, AT1 has been found to be a regulator of cardiocyte ionic channel remodeling, and calcineurin-NFAT signals participate in the regulation of cardiocyte ionic channel expression. A hypothesis therefore follows that stretch stimulation may regulate cardiocyte ionic channel remodeling by activating the AT1 -calcineurin-NFAT pathway. Here, we investigated the role of the AT1 -calcineurin-NFAT pathway in the remodeling of inward rectifier potassium (Ik1 ) channel, in addition to its role in changing action potential, in stretch-induced hypertrophic atrial myocytes of neonatal rats. Our results showed that increased stretch significantly led to atrial myocytes hypertrophy; it also increased the activity of calcineurin enzymatic activity, which was subsequently attenuated by telmisartan or cyclosporine-A. The level of NFAT3 protein in nuclear extracts, the mRNA and protein expression of Kir2.1 in whole cell extracts, and the density of Ik1 were noticeably increased in stretched samples. Stretch stimulation significantly shortened the action potential duration (APD) of repolarization at the 50% and 90% level. Telmisartan, cyclosporine-A, and 11R-VIVIT attenuated stretch-induced alterations in the levels of NFAT3 , mRNA and protein expression of Kir2.1, the density of Ik1 , and the APD. Our findings suggest that the AT1 -calcineurin-NFAT signaling pathway played an important role in regulating Ik1 channel remodeling and APD change in stretch-induced hypertrophic atrial myocytes of neonatal rats.