Publications by authors named "Shuo Chang"

13 Publications

  • Page 1 of 1

Generation of coherent multicolor noise-like pulse complex in Yb-doped fiber laser mode-locked by GIMF-SA.

Opt Express 2021 May;29(10):14336-14344

We have demonstrated the generation of multicolor noise-like pulse complex in a passively Yb-doped mode-locked fiber laser based on a single mode-graded index multimode-single mode fiber (SMF-GIMF-SMF) device as the saturable absorber (SA). The stimulated Raman scattering (SRS) effect leads to the cascaded generation of the main noise-like pulse (NLP) at 1028.8 nm together with the noise like Raman pulse (RP) at 1076.1 nm. The generated dual wavelength pulses demonstrate the unique properties of mutually synchronization and coherence. The autocorrelation traces show that each of the synchronously mode-locked pulses exhibits a double-scale structure with a narrow peak which consists of a train of quasi-periodic beat pulses with a 35.7 fs pulse width and a pulse separation of about 77.2 fs. The total output power reaches 102.5 mW with 34% of it belonging to the RP. And furthermore, by separating the two pulses with spectral filters, the modulation fringes cannot be observed anymore. These results indicate that the Raman component participates in the mode-locking operation as a 'signal' instead of 'noise'. Such a coherent Raman pulse source provides a novel platform for numerous applications, such as frequency comb spectroscopy and so on.
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http://dx.doi.org/10.1364/OE.425326DOI Listing
May 2021

High-power synchronous multi-wavelength solitons from a multimode mode-locked fiber laser system.

Opt Lett 2021 Jan;46(1):118-121

In this Letter, we implement a multimode fiber (MMF) laser system mode-locked by a nonlinear polarization rotation technique for controllable synchronous multi-wavelength soliton generation. The synchronization of the repetition rates for different wavelengths is realized by the special mode transmission in MMF. For dual-wavelength mode-locking at 1566.7 nm and 1617.2 nm, each of the synchronously mode-locked solitons consists of a train of quasi-periodic beat pulses with a pulse width of 84 fs and period of 162 fs. The total output power reaches 532 mW with optimally balanced two-color intensities. Furthermore, switchable dual- and tri-wavelength synchronized femtosecond pulses are also obtained. In contrast to previous reports, this synchronously mode-locked multi-wavelength is output directly from a laser oscillator, which provides a simpler candidate to achieve pulse synchronization.
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http://dx.doi.org/10.1364/OL.412739DOI Listing
January 2021

CaMK4 promotes abortion-related Th17 cell imbalance by activating AKT/mTOR signaling pathway.

Am J Reprod Immunol 2020 12 15;84(6):e13315. Epub 2020 Aug 15.

Reproductive Medical Center, Renmin Hospital of Wuhan University and Hubei Clinic Research Center for Assisted Reproductive Technology and Embryonic Development, Wuhan, China.

Problem: The balance of the immune microenvironment along the maternal-fetal interface is closely related to pregnancy outcomes, with excessive inflammatory reactions leading to the occurrence of pathological pregnancy outcomes such as abortion. CaMK4 has been reported to play a significant role in autoimmune diseases through the regulation of Th17 cells. However, whether CaMK4 is associated with spontaneous abortion or the immune microenvironment along the maternal-fetal interface remains unclear.

Methods Of Study: In this study, we constructed normal pregnancy and LPS-induced abortion models in mice, and a CaMK4 inhibitor called KN-93 was administered to investigate the changes in and mechanisms of the immune response. The expression of CaMK4 was evaluated in the uteroplacental complex and spleen. Furthermore, the infiltration and function of Th17 cells were estimated in peripheral tissues and the uteroplacental complex.

Results: The expression of CaMK4 in the uteroplacental complex and spleen was significantly higher in the LPS-treated group than in the normal pregnancy group. KN-93, the CaMK4 inhibitor, reversed fetal resorption and excessive inflammation. In detail, KN-93 led to reduced infiltration of Th17 cells into peripheral tissues and the uteroplacental complex, and the functions of Th17 cells were inhibited. In addition, CaMK4 promoted the AKT/mTOR signaling pathway, which is one of the mechanisms that regulate the immune microenvironment.

Conclusion: CaMK4 is a critical regulator that promotes the expansion of Th17 cells and enhances their functions through the AKT/mTOR signaling pathway. The inhibition of CaMK4 can reverse the immune imbalance along the maternal-fetal interface and improve pregnancy outcomes.
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http://dx.doi.org/10.1111/aji.13315DOI Listing
December 2020

Insights into the effects of acetate on the community structure of Candidatus Accumulibacter in biological phosphorus removal system using DNA stable-isotope probing (DNA-SIP).

Enzyme Microb Technol 2020 Sep 27;139:109567. Epub 2020 Apr 27.

National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, Beijing, 100124, China.

Sodium acetate has been most commonly used as the external carbon source to achieve successful performance of full-scale enhanced biological phosphorus removal (EBPR) processes, but its microbial mechanism for the improvement of phosphorus removal performance was still unclear. DNA based stable-isotope probing (DNA-SIP) is able to discriminate the metabolic activity of different microbes for specific substrates, thus it was applied to explore the different effects of sodium acetate on the community structure of Candidatus Accumulibacter (hereafter called Accumulibacter) and Candidatus Competibacter (hereafter called Competibacter) in a modified University of Cape Town (MUCT) process treating the real domestic sewage. Results showed that acetate addition significantly improved the abundance of Accumulibacter and Competibacter in MUCT. Accumulibacter clade IID exhibited the highest proportion in all clades before and after acetate supplementation but the proportion decreased from 95.4 % on day 23-66.3% on day 95. Contrarily, the proportion of clade IIF increased from 0.9% to 24%. DNA-SIP incubation found that the ratio of Accumulibacter in the heavy fractions to the total quantities increased faster than that of Competibacter, which successfully revealed the acetate assimilating precedence of Accumulibacter over Competibacter. Besides, the ratios of Accumulibacter clade IIF in heavy fraction increased by 22.3 %, exhibited a higher metabolic activity than other clades. Adequate acetate accomplied with high temperature possibly promoted the preferential proliferation of clade ⅡF, which provided a way to enrich clade IIF. This is the first study that successfully applied DNA-SIP to discriminate the acetate metabolic activity of Accumulibacter and Competibacter, and Accumulibacter clades.
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http://dx.doi.org/10.1016/j.enzmictec.2020.109567DOI Listing
September 2020

Spatial Attention Fusion for Obstacle Detection Using MmWave Radar and Vision Sensor.

Sensors (Basel) 2020 Feb 11;20(4). Epub 2020 Feb 11.

School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China.

For autonomous driving, it is important to detect obstacles in all scales accurately for safety consideration. In this paper, we propose a new spatial attention fusion (SAF) method for obstacle detection using mmWave radar and vision sensor, where the sparsity of radar points are considered in the proposed SAF. The proposed fusion method can be embedded in the feature-extraction stage, which leverages the features of mmWave radar and vision sensor effectively. Based on the SAF, an attention weight matrix is generated to fuse the vision features, which is different from the concatenation fusion and element-wise add fusion. Moreover, the proposed SAF can be trained by an end-to-end manner incorporated with the recent deep learning object detection framework. In addition, we build a generation model, which converts radar points to radar images for neural network training. Numerical results suggest that the newly developed fusion method achieves superior performance in public benchmarking. In addition, the source code will be released in the GitHub.
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http://dx.doi.org/10.3390/s20040956DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7070402PMC
February 2020

Analysis of microbial community in a continuous flow process at gene and transcription level to enhance biological nutrients removal from municipal wastewater.

Bioresour Technol 2019 Aug 23;286:121374. Epub 2019 Apr 23.

National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.

In biological municipal wastewater treatment, gene level analysis of community structure could not determine functional genes that actually played a role and expression of viable microorganism. In this study, reverse transcriptional PCR (RT-PCR), cDNA high throughput sequencing and transcriptional activity analysis were conducted to investigate active microbial community with nitrogen and phosphorus removal from municipal wastewater. RT-PCR and correlation heatmap analysis suggested that transcriptional activities of bacteria had strong correlation with performance of nitrogen and phosphorus removal, they might be therefore regarded as an indicator for wastewater treatment monitoring. When DO concentration were raised from 0.6 mg/L to 2 mg/L and C/N ratio from 3-4 to 5, the increase of population abundance and transcriptional activities of denitrifying genes improved the removal efficiencies of COD and TN. The species with relatively high abundance at gene level were not really active species at transcription level, and vice versa.
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http://dx.doi.org/10.1016/j.biortech.2019.121374DOI Listing
August 2019

Online Siamese Network for Visual Object Tracking.

Sensors (Basel) 2019 Apr 18;19(8). Epub 2019 Apr 18.

School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China.

Offline-trained Siamese networks are not robust to the environmental complication in visual object tracking. Without online learning, the Siamese network cannot learn from instance domain knowledge and adapt to appearance changes of targets. In this paper, a new lightweight Siamese network is proposed for feature extraction. To cope with the dynamics of targets and backgrounds, the weight in the proposed Siamese network is updated in an online manner during the tracking process. In order to enhance the discrimination capability, the cross-entropy loss is integrated into the contrastive loss. Inspired by the face verification algorithm DeepID2, the Bayesian verification model is applied for candidate selection. In general, visual object tracking can benefit from face verification algorithms. Numerical results suggest that the newly developed algorithm achieves comparable performance in public benchmarks.
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http://dx.doi.org/10.3390/s19081858DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514741PMC
April 2019

Acetyl-L-carnitine: An effective antioxidant against cryo-damage on human spermatozoa with asthenospermia.

J Huazhong Univ Sci Technolog Med Sci 2017 Dec 21;37(6):915-921. Epub 2017 Dec 21.

Reproductive Medicine Center, Renmin Hospital of Wuhan University, Wuhan, 430060, China.

A variety of natural and artificial cryoprotectant extenders have been explored to enhance sperm recovery following cryopreservation-thawing process. The current investigation is aimed at evaluating the effect of acetyl-L-carnitine on human spermatozoa and reactive species oxygen (ROS) level after freezing-thawing process. The spermatozoa were collected from 35 male patients diagnosed as having asthenospermia. The cryopreservation of human spermatozoa treated with acetyl-L-carnitine at different concentrations (group B: 2.5 mmol/L, group C: 7.5 mmol/L, group D: 15 mmol/L) was compared with control (group A: no acetyl-L-carnitine given). For the frozen-thawed spermatozoa, the viability, motility and DNA integrity were measured by comet assay, acrosome integrity by FITC-PNA staining and ROS level was determined in each group. The results showed that there were no significant differences in motility and viability between group A and group B, while the motility and viability of spermatozoa in group C and group D were significantly increased as compared with those in group A. As compared with group A, the values for DNA integrity parameters including comet rate (CR), tail DNA percentage (TD), tail length (TL) and Oliver tail moment (OTM) were significantly reduced in group C and group D. Group C and group D also displayed a higher proportion of intact acrosome than group A. No significant difference in ROS level was found between group A and group B, while with the increase in acetyl-L-carnitine concentration, the ROS level in groups C and D was significantly reduced as compared with that in group A. In conclusion, acetyl-L-carnitine at a concentration of 7.5 mmol/L is an effective antioxidant against cryo-damage on post-thawed human spermatozoa.
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http://dx.doi.org/10.1007/s11596-017-1827-4DOI Listing
December 2017

Probing polarity of flame retardants and correlating with interaction between flame retardants and PET fiber.

J Colloid Interface Sci 2017 Jul 11;498:343-350. Epub 2017 Mar 11.

College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China. Electronic address:

The empirical polarity parameter E(30) was determined for polyethylene terephthalate (PET) fiber and five phosphorus flame retardants by UV-Vis absorption spectrum of solvatochromic probe. To investigate the interaction between flame retardant and PET fiber during the finishing process, the partition coefficients K of these flame retardants between water and PET fiber were determined and an interesting linear relationship between lnK and E(30) of the flame retardants was obtained, suggesting E(30) is definitely an excellent estimation of the interaction of flame retardants with PET. Additionally, the thermodynamic criterion of this finishing process, standard Gibbs free energy of transfer of the flame retardants from water to PET fiber, ΔG(FR,HO→PET), was found to linearly correlate with E(30) of the flame retardants as well, ΔG(FR,HO→PET)=0.3664∗E(30)(FR) -18.60 (R=0.9168), demonstrating polarity of flame retardant is an important and determining factor for its fixation on PET fiber. This work may provide theoretical guidance for choosing flame retardant finishing agent more compatible with PET fabric.
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http://dx.doi.org/10.1016/j.jcis.2017.03.047DOI Listing
July 2017

High fructose causes cardiac hypertrophy via mitochondrial signaling pathway.

Am J Transl Res 2016 15;8(11):4869-4880. Epub 2016 Nov 15.

Research Center of Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100037, People's Republic of China.

High fructose diet can cause cardiac hypertrophy and oxidative stress is a key mediator for myocardial hypertrophy. Disruption of cystic fibrosis transmembrane conductance regulator (CFTR) leads to oxidative stress. This study aims to reveal mitochondrial oxidative stress-related signaling pathway in high fructose-induced cardiac hypertrophy. Mice were fed high fructose to develop cardiac hypertrophy. Fructose and HO were used to induce cardiomyocyte hypertrophy in vitro. Mitochondria-targeted antioxidant SkQ1 was applied to investigate the possible role of mitochondrial reactive oxygen species (ROS). CFTR silence was performed to detect the role of CFTR in high fructose-induced myocardial hypertrophy. ROS, glutathione (GSH), mitochondrial function and hypertrophic markers were measured. We confirmed that long-term high fructose diet caused cardiac hypertrophy and diastolic dysfunction and elevated mitochondrial ROS. However, SkQ1 administration prevented heart hypertrophy and mitochondrial oxidative stress. Cadiomyocytes incubated with fructose or HO exhibited significantly increased cell areas but SkQ1 treatment ameliorated cardiomyocyte hypertrophy induced by high fructose or HO in vitro. Those results revealed that the underlying mechanism for high fructose-induced heart hypertrophy was attributed to mitochondrial oxidative stress. Moreover, CFTR expression was decreased by high fructose intervention and CFTR silence resulted in an increase in mitochondrial ROS, which suggested high fructose diet affected mitochondrial oxidative stress by regulating CFTR expression. Electron transport chain impairment might be related to mitochondrial oxidative damage. In conclusion, our findings indicated that mitochondrial oxidative stress plays a central role in pathogenesis of high fructose-induced cardiac hypertrophy. High fructose decreases CFTR expression to regulate mitochondrial oxidative stress.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5126329PMC
November 2016

Prognostic value of serum galactomannan index in critically ill patients with chronic obstructive pulmonary disease at risk of invasive pulmonary aspergillosis.

Chin Med J (Engl) 2014 ;127(1):23-8

Department of Respiratory and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China; Department of Critical Care Medicine, China-Japan Friendship Hospital, Beijing 100029, China. Email:

Background: Critically ill chronic obstructive pulmonary disease (COPD) patients admitted to an intensive care unit (ICU) due to respiratory failure are at particularly high risk of Aspergillus infection. The serum galactomannan index (GMI) has proven to be one of the prognostic criteria for invasive pulmonary aspergillosis (IPA) in classical immunocompromised patients. However, the prognostic value of serum GMI in critically ill COPD patients needs evaluation. The purpose of this study is to investigate the prognostic value of serum GMI in patients with severe COPD.

Methods: In this single-center prospective cohort study, serum samples for GMI assay were collected twice a week from the first day of ICU admission to the day of the patients' discharge or death. Patients were divided into two groups according to their clinical outcome on the 28th day of their ICU admission. Univariate analysis and survival analysis were tested in these two groups.

Results: One hundred and fifty-three critically ill COPD patients were included and were divided into survival group (106 cases) and non-survival group (47 cases) according to their outcome. Univariate analysis showed that the highest GMI level during the first week after admission (GMI-high 1st week) was statistically different between the two groups. Independent prognostic factors for poor outcome in severe COPD patients were: GMI-high 1st week >0.5 (RR: 4.04, 95% CI: 2.17-7.51) combined with accumulative dosage of corticosteroids >216 mg before the RICU admission (RR: 2.25, 95% CI: 1.11-4.56) and clearance of creatinine (Ccr) ≤ 64.31 ml/min (RR: 2.48, 95% CI: 1.22 ± 5.07).

Conclusions: The positive GMI-high 1st week (>0.5) combined with an accumulative dosage of corticosteroids >216 mg before the ICU admission and a low Ccr may predicate a poor outcome of critically ill COPD patients.
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June 2014

Significance of Aspergillus spp. isolation from lower respiratory tract samples for the diagnosis and prognosis of invasive pulmonary aspergillosis in chronic obstructive pulmonary disease.

Chin Med J (Engl) 2012 Sep;125(17):2973-8

Department of Respiratory and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China.

Background: Chronic obstructive pulmonary diseases (COPD) is an emerging population at risk for invasive infection of Aspergillus. Isolation of Aspergillus from lower respiratory tract (LRT) samples is important for the diagnosis of invasive pulmonary aspergillosis (IPA). The purpose of this study was to investigate the value of Aspergillus isolation from LRT samples for the diagnosis and prognosis of IPA in COPD population.

Methods: Clinical record with Aspergillus spp. isolation in COPD and immunocompromised patients was reviewed in a retrospective study. Patients were categorized and compared according to their severity of illness (admitted to general ward or ICU) and immunological function (COPD or immunocompromised).

Results: Multivariate statistical analysis showed that, combined with Aspergillus spp. isolation, APACHE II scores > 18, high cumulative doses of corticosteroids (> 350 mg prednisone or equivalent dose) and more than four kinds of broad-spectrum antibiotics received in hospital may be predictors of IPA in COPD (OR = 9.076, P = 0.001; OR = 4.073, P = 0.026; OR = 4.448, P = 0.021, respectively). The incidence of IPA, overall mortality, mortality of patients with IPA and mortality of patients with Aspergillus spp. colonization were higher in COPD patients in ICU than in general ward, but were similar between COPD and immunocompromised patients.

Conclusions: Aspergillus spp. isolation from LRT in COPD may be of similar importance as in immunocompromised patients, and may indicate an increased diagnosis possibility of IPA and worse prognosis when these patients received corticosteroids, antibiotics, and need to admit to ICU. Aspergillus spp. isolation from LRT samples combined with certain risk factors may be useful in differentiating colonization from IPA and evaluating the prognosis of IPA in COPD patients.
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September 2012

Value of consecutive galactomannan determinations for the diagnosis and prognosis of invasive pulmonary aspergillosis in critically ill chronic obstructive pulmonary disease.

Med Mycol 2011 May 11;49(4):345-51. Epub 2010 Oct 11.

Department of Respiratory and Critical Care Medicine, Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.

Critically ill chronic obstructive pulmonary disease (COPD) patients who are admitted to intensive care units (ICU) are at particular risk for invasive pulmonary aspergillosis (IPA). The objective of this investigation was to assess the value of consecutive galactomannan (GM) tests in determining the diagnosis and prognosis of IPA in this patient population. We studied 90 critically ill COPD patients admitted to our ICU between February 2007 and November 2009. Two consecutive serum GM tests were done on the first and fourth days of their ICU admissions. Patients were classified as proven IPA (n = 1), probable IPA (n = 18), or non-IPA (n = 71). The sensitivities, specificities, and positive and negative predictive values of GM test results for (i) the first test, (ii) the second test, (iii) at least one positive of two consecutive tests and (iv) two positive consecutive GM tests were, respectively, 57.9%/64.7%/70.6%/47.1%; 87.3%/84.6%/80.8%/94.2%; 55.0%/57.9%/54.5%/72.7%; and 88.6%/88.0%/89.4%/84.5%. The mortality values of IPA patients with (i) a positive first GM test, (ii) at least one of two tests positive, and (iii) both tests positive were (a) 81.8% (9/11), (b) 83.3% (10/12), and (c) 72.7% (8/11), respectively. These results indicate that at least one positive result of two consecutive GM tests appears to be useful in the diagnosis of IPA in critically ill COPD patients in an ICU. In addition, positive serum GM results combined with the isolation of Aspergillus from respiratory samples may be a potential marker of high mortality.
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http://dx.doi.org/10.3109/13693786.2010.521523DOI Listing
May 2011