Search

The polarization switching (PS) properties of mutually coupled vertical-cavity surface-emitting lasers (VCSELs) subject to variable-polarization optical feedback (VPOF) are investigated numerically. Two injection schemes, parallel-polarization optical injection (PPOI), and orthogonal-polarization optical injection (OPOI) are considered. The effects of VPOF on PS properties are focused on, and the roles of feedback strength, injection strength, and frequency detuning are also discussed. The outputs in the time domain and the polarization evolution through the representation on the Poincaré sphere are further presented to explain the dynamics during the PS process. For PPOI, both VCSELs exhibit similar PS properties, abrupt PS can be observed with the variation of polarizer angle, and are hardly affected by frequency detuning. For OPOI, both VCSELs exhibit mixed polarization for all polarizer angles when without frequency detuning. In particular, frequency detuning induced PS can also be observed for a given polarizer angle, and are affected by the leader-lagged relationship in terms of injection locking effect in mutually coupled VCSELs. These results provide an effective tool to obtain controllable PS in mutually coupled VCSELs, and give more insight into the polarization dynamics. [ABSTRACT FROM PUBLISHER]

The unpredictability properties of an optical microring resonator with modulation are investigated quantitatively, by adopting a recently introduced quantifier, the permutation entropy (PE). We can obtain rich nonlinear dynamics, such as period, bifurcation, and chaos by changing the modulation coefficients and the input power. The effect of the nonlinear refractive index is also considered. Moreover, we adopt the permutation entropy to quantify the unpredictability of the resonator's output. The results not only qualitatively agree with the dynamical changes, but also indicate the unpredictability of the chaotic regimes. The chaotic carrier with high PE values would contribute to the unpredictability-enhanced optical microring resonator-based chaotic communication. [ABSTRACT FROM AUTHOR]

Objective: To observe the effect of electroacupuncture (EA) at "Zusanli"(ST36) pretreatment on lung functions, inflammatory response, and levels of angiotensin-converting enzyme 2 (ACE2) and angiotensin (1-7) ［Ang (1-7)］ in rats with sepsis-induced acute lung injury (ALI), so as to explore its mechanisms underlying improvement of ALI., Methods: Thirty male SD rats were randomly divided into normal, model and EA groups ( n =10 in each group). The sepsis-related ALI model was established by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg). Rats of the EA group received EA (4 Hz/20 Hz, 1-3 mA) stimulation at bilateral ST36 for 30 min, once each day, for 7 days before modeling. The lung functions including forced vital capacity (FVC), forced expiratory volume at 0.1 second (FEV0.1) and FEV0.3 were detected using a respiratory function detector for small animals at 3 h after modeling. The bronchoalveolar lavage fluid (BALF) was collected for assaying the contents of Ang (1-7), tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β) using ELISA. The lung wet/dry weight (W/D) ratio, FEV0.1/FVC, and FEV0.3/FVC were calculated. The histopathological changes of lung tissues were displayed by hematoxylin-eosin (H.E.) staining. The expression of ACE2 and mitochondrial assembly receptor (MasR) mRNAs and proteins in the lung tissue was detected by fluorescence quantitative real-time PCR and Western blot, separately., Results: Following modeling, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and the expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly decreased ( P <0.01), while the level of W/D ratio and TNF-α and IL-1β contents in the BALF significantly increased ( P <0.01) in the model group relevant to the normal group. In comparison with the model group, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly increased ( P <0.05, P <0.01), whereas the level of W/D ratio, and TNF-α and IL-1β contents in the BALF were significantly decreased ( P <0.05, P <0.01) in the EA group. H.E. staining showed pulmonary interstitial edema and alveolar septum thickening with severe inflammatory cell infiltration in the model group, which was relatively milder in the EA group., Conclusion: EA preconditioning at ST36 can improve pulmonary function in sepsis-related ALI rats, which may be related to its effects in inhibiting inflammatory response and up-regulating ACE2 and MasR expression and Ang (1-7) content in the lung tissue.

Objective: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST36) and "Feishu" (BL13) on the activation and secretion of calcitonin gene-related peptide (CGRP) and 5-hydroxytryptamine (5-HT) of pulmonary neuroendocrine cells (PNECs) and inflammatory response in rats with chronic obstructive pulmonary disease (COPD), so as to explore its underlying mechanisms in treating COPD., Methods: Male SD rats were randomly divided into normal control, COPD model and EA groups, with 7 rats in each group. The COPD model was established by forced inhale of cigarette smoke for 1 h in a self-made box (1 m×1 m×1 m in volume), twice daily for 12 weeks. EA (4 Hz/20 Hz, 1-3 mA) was applied at bilateral ST36 and BL13 acupoints for 30 min, once a day for 14 consecutive days. The pulmonary function including the forced vital capacity (FVC), forced expiratory volume at 0.1 second (FEV0.1), FEV0.3, FEV0.1/FVC and FEV0.3/FVC was detected using a lung function analyzer for small animals. The lung tissue was sampled for observing histopathological changes by using H.E. staining, for observing expression and distribution of PNECs by Grimelius silver staining, and for detecting the immunoactivity (integrated optical density) of CGRP and 5-HT by using immunohistochemistry. The contents of CGRP, 5-HT, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) in the bronchoalveolar lavage fluid (BALF) and lung tissue were detected by ELISA, and the correlations between TNF-α and CGRP, IL-1β and CGRP, TNF-α and 5-HT, and IL-1β and 5-HT levels were analyzed. The mRNA and protein expression levels of nerve fiber markers of CGRP and purinergic receptor P2X ligand gated ion channel 3 (P2X3) which dominate PNECs in the lung tissue were detected by real-time fluorescence quantitative PCR and Western blot, respectively., Results: Compared with the normal control group, the levels of FVC, FEV0.1, FEV0.3, and the ratios of FEV0.1/FVC and FEV0.3/FVC were significantly decreased ( P <0.05, P <0.01), while the immunoactivity of PNECs, CGRP and 5-HT, the contents of CGRP, 5-HT, TNF-α, IL-1β and TGF-β1 in the BALF and lung tissue, and the expression levels of CGRP and P2X3 mRNAs and proteins in the lung tissue significantly increased in the COPD model group ( P <0.01, P <0.05). Following EA intervention, both the increased and decreased levels of all the indexes mentioned above were reversed ( P <0.05, P <0.01) except FEV0.3. H.E. staining showed severe deformed bronchial lumen with thickened wall and alveolar septum, and obvious inflammatory cell infiltration and reduced number of alveolar lumen fusion in the COPD model group, which was mild in the EA group. A positive correlation was found between TNF-α and CGRP, IL-1β and CGRP, TNF-α and 5-HT,IL-1β and 5-HT levels in both BALF and lung tissues ( P <0.01)., Conclusion: EA at ST36 and BL13 can improve lung function and reduce inflammatory response in COPD rats, which may be related to its function in inhibiting the activation of PNECs and release of neuroactive substances.

Objective: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST36) and "Feishu" (BL13) on the expression of autophagy related proteins in the lung tissue of rats with chronic obstructive pulmonary disease (COPD), so as to explore the mechanism of EA underlying improvement of COPD., Methods: Thirty male SD rats were randomly divided into normal, model and EA groups ( n =10 in each group). The COPD model was established by intratracheal infusion of Lipopolysaccharide (LPS, 1 mg/kg) and exposure in cigarette smoke. EA was applied to bilateral ST36 and BL13 for 30 min, once every other day for 2 weeks. The pulmonary function (forced vital capacity ［FVC］, forced expiratory volume in 0.1 s and 0.3 s ［FEV0.1, FEV0.3］, FEV0.1/FVC and FEV0.3/FVC) was detected by animal pulmonary function analysis system. Histopathological changes of the airway and lung were displayed by H.E. staining. Autophagosomes in the airway and lung tissues were observed by electron microscope. The expression of AMP activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), Unc-51 like autophagy activating kinase 1(ULK1), autophagy related protein ATG6(Beclin1)mRNAs in lung tissue were examined by quantitative real-time PCR. The expression of AMPK, mTOR, ULK1, Beclin1 and microtubule-associated protein 1 light chain 3 (LC3)proteins in lung tissue were examined by Western blot. The contents of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) in the broncho alveolar lavage fluid (BALF) were assayed by ELISA., Results: Following modeling, the FVC, FEV0.1, FEV0.3, FEV0.1/FVC and FEV0.3/FVC levels were significantly decreased ( P <0.01), the infiltration of inflammatory cells and the increase of autophagosomes were obvious in airway and lung tissue, the mRNA and protein expression of AMPK, ULK1, Beclin1 and the ratio of LC3Ⅱ/LC3Ⅰ were increased ( P <0.01), while the mRNA and protein expression of mTOR were decreased ( P <0.01), the contents of TNF-α and IL-6 in the BALF were increased in the model group compared with the normal group ( P <0.01). After EA intervention, all the indexes mentioned above were completely reversed in the EA group relevant to the model group ( P <0.01, P <0.05)., Conclusion: EA at ST36 and BL13 can improve the lung function of COPD rats, which may be related to its effects in inhibiting the autophagy level and reducing the inflammation response in the lung.

Objective: To observe the effect of electroacupuncture (EA) at "Zusanli"(ST36) on the expression of epidermal growth factor receptor (EGFR), tumor necrosis factor α(TNF-α) transfer growth factor α(TGF-α), interleukin-8(IL-8), p38 mitogen-activated protein kinases (p38MAPK), mucin-5AC (MUC5AC) and other related factors in chronic obstructive pulmonary disease (COPD) rats, so as to reveal its underlying mechanisms in improving COPD., Methods: A total of thirty male SD rats were randomly divided into normal control, model and EA groups, with 10 rats in each group. The COPD model was replicated using a combined method of tracheal infusion of lipopolysaccharide (LPS) and forced smoke-inhaling. EA (1-3 mA, 4 Hz/20 Hz) was applied to bilateral ST36 for 30 min, once daily for two consecutive weeks. The lung ventilation activities including the forced vital capacity (FVC) and forced expiratory volume (FEV) at 0.1 and 0.3 s (FEV0.1, FEV0.3) were detected. Histopathological changes of the middle lobe and bronchus of the right lung were observed after H.E. staining. The contents of TGF-α, TNF-α and IL-8 in the serum, bronchoalveolar lavage fluid (BALF) and superior lobe of the right lung were assayed by using ELISA, and the expression levels of EGFR, p38MAPK and MUC5AC proteins (inferior lobe of the left lung) and mRNAs (inferior lobe of the right lung) detected using Western blot, immunohistochemistry (strept avidin-biotin complex, SABC method) and real-time quantitative PCR, respectively., Results: Compared with the normal group, the FVC, FEV0.1, FEV0.3, FEV0.1/FVC and FEV0.3/FVC levels were significantly decreased ( P <0.01), while the contents of TNF-α, TGF-α and IL-8 in the serum, BALF and lung tissues, expression levels of EGFR, p38MAPK and MUC5AC mRNAs and proteins, and the immunoactivity of EGFR, p38MAPK and MUC5AC in the lung tissues were significantly increased in the model group ( P <0.01). After EA intervention, the decreased levels of the FVC, FEV0.1, FEV0.3, FEV0.1/FVC and FEV0.3/FVC, and the increased levels of the abovementioned genes and proteins were all reversed in the EA group ( P <0.01, P <0.05). After modeling, the bronchial walls were thickened, with enlarged alveolar cavities, fractured alveolar walls, obvious inflammatory cell infiltration, and rich mucus secretion in the lumen, which was relatively milder in the EA group., Conclusion: EA of ST36 can improve the ventilation function in COPD rats, which may be associated with its function in down-regulating the levels of TNF-α, TGF-α, IL-8, EGFR, p38MAPK and MUC5AC mRNAs and proteins in the lung tissues, inhibiting EGFR-p38MAPK signaling mediated expression of MUC5AC.

Objective: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST 36) and "Feishu" (BL 13) on pulmonary function, inflammatory reaction and expression of macrophage migration inhibitory factor (MIF) and its receptor complex CD 74-CD 44, etc. in rats with chronic obstructive pulmonary disease (COPD), so as to explore its mechanism underlying improvement of COPD., Methods: Thirty male SD rats were randomly divided into normal, model and EA groups ( n ＝10 in each group). The COPD model was established by intratracheal infusion of Lipopolysaccharide (LPS, 1 mg/mL) and forced smoke-inhaling. EA was applied to bilateral ST 36 and BL 13 for 30 min, once daily for 7 days. The rat's lung function (forced vital capacity [FVC], forced expiratory capacity ratio ([FEV 0.1/FVC] and [FEV 0.3/FVC]) was detected under anesthesia. Pathological changes of the lung tissue were detected by H．E. staining, and the contents of MIF, tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1 β) and IL-8 in serum, bronchoalveolar lavage fluid (BALF) and lung tissue were assayed by ELISA. The immunoactivity of CD 74 and CD 44 was detected by immunohistochemistry, and the expression levels of MIF, CD 74, CD 44 and p 38 MAPK mRNAs and proteins were examined by quantitative RT-PCR and Western blot, respectively., Results: Compared with the normal group, the FVC, FEV 0.1, FEV 0.3, FEV 0.1/FVC and FEV 0.3/FVC levels were significantly decreased in the model group ( P <0.01). After EA treatment, the FVC, FEV 0.1, FEV 0.3, FEV 0.1/FVC and FEV 0.3/FVC were significantly increased ( P <0.01, P <0.05), suggesting an improvement of the pulmonary function after EA. H．E. staining showed that the severity of modeling induced alveolar expansion and inflammatory cell infiltration in the lung tissue was relatively milder in the EA group relevant to the model group. The contents of MIF, TNF-α， IL-1 β and IL-8 in the serum, BALF and lung tissues were significantly higher in the model group than in the normal group ( P <0.01), and significantly down-regulated in the EA group relevant to the model group ( P <0.01). The expression levels of MIF, CD 74, CD 44 and p 38 MAPK mRNAs and proteins and the immunoactivity levels of CD 74, CD 44 in the lung tissue were obviously higher in the model group than those in the normal group ( P <0.01), and considerably lower in the EA group than those in the model group ( P <0.01). There was a positive correlation between p 38 MAPK and MIF in mRNA and protein expression levels ( P <0.01)., Conclusion: EA intervention can improve the pulmonary function in COPD rats, which may be related to its effects in inhibiting inflammatory reaction, and MIF/CD 74-CD 44/p 38 MAPK signaling pathway.

Objective: We have repeatedly demonstrated that electroacupuncture (EA) stimulation of "Shenmen" (HT 7)- "Tongli" (HT 5) segment of the Heart Meridian can improve acute myocardial ischemia (AMI). This study aimed at observing the effect of EA on contents of hippocampal norepinephrine (NE), and interleukin 6 (IL-6), IL-1 β and tumor necrosis factor- α (TNF-α) in AMI rats, so as to explore its underlying mechanism., Methods: SD rats were randomly divided into 3 groups: sham operation (sham), model and EA( n =6 rats in each). The anterior descending branch (ADB) of the left coronary artery was occluded to make an AMI model. For rats of the sham group, a surgical suture was simply threaded beneath the ADB without ligation. EA (2 Hz/15 Hz, 1 mA) was applied to bilateral "Shenmen" (HT 7)- "Tongli" (HT 5) and the middle-point between HT 7 and HT 5 for 30 min, once daily for 3 days. Electrocardiogram (ECG) of the neck-thoracic lead was recorded by using PowerLab 16. The contents of serum creatine kinase (CK), hippocampal IL-6, IL-1 β and TNF-α were assayed by ELISA. The concentration of NE in hippocampal CA 1 area was detected by microdialysis combined with electrochemical detector., Results: Compared with the sham group, the ECG-ST height, serum CK, hippocampal NE, IL-6, IL-1 β and TNF-α contents of the CA 1 region were significantly increased in the model group ( P <0.001). Whereas, after EA intervention, the serum CK, hippocampal NE, IL-6, IL-1 β and TNF-α contents were obviously down-regulated relevant to the model group ( P <0.05, P <0.001), and the IL-6, IL-1 β and TNF-α contents were positively correlated with the NE level ( P <0.001, P <0.01)., Conclusion: EA stimulation of the Heart Meridian may improve ischemic myocardial injury in AMI rats, probably by reducing the proinflammatory factors and hippocampal NE.