Browsing by Author "Lin, Chih-Sheng"

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3D Real-Time Image-Guided Navigation Spine Corpectomy with Ultrasonic Bone Cutter: Technical Note
(2020-03-01)
Lin, Chung-Wei
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Chang, Chien-Chun
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Chen, Hsien-Te
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Chen, Yen-Jen
;
Lin, Chih-Sheng
BACKGROUND: Surgical interventions for congenital scoliosis are challenging for spine surgeons. The coordination of 3-dimensional (3D), real-time, image-guided navigation with an ultrasonic bone cutter allows surgeons to localize the affected area of the spine accurately and remove the lesion without damaging soft tissue structures. The goal of this technical paper is to report a previously undescribed method of hemivertebrectomy that combines 3D, real-time, image-guided navigation and an ultrasonic bone cutter. We highlight the feasibility and safety of this method in spinal surgery. METHODS: Three patients with congenital scoliosis were treated with this technique. We present three illustrative cases comprising hemivertebrectomies for congenital scoliosis. Intraoperative photos demonstrating the technique are also provided. RESULTS: All surgeries were completed without complications. The hemivertebrae were completely removed, and marked correction of congenital scoliosis was noted. CONCLUSIONS: We believe that the combination of 3D, real-time image navigation and an ultrasonic bone cutter improves hemivertebrectomy by increasing accuracy and avoiding dura laceration, major organ damage, or potential vessel damage.
A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus
(2009-05-27)
Chen, Sz-Hau
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Chuang, Yao-Chen
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Lu, Yi-Chen
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Lin, Hsiu-Chao
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Yang, Yun-Liang
Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change (Delta F) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml(-1) and a linear correlation (R(2) = 0.987) of Delta F versus virus titration from 2 x 10(0) to 2 x 10(6) PFU ml(-1) was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.
A mutant strain of microalga Chlorella sp for the carbon dioxide capture from biogas
(2012-01-01)
Kao, Chien-Ya
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Chiu, Sheng-Yi
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Huang, Tzu-Ting
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Dai, Le
;
Wang, Guan-Hua
To upgrade biogas produced from the anaerobic digestion of swine wastewater, an outdoor photobioreactor was established in this study. A mutant strain of microalga Chlorella sp. MM-2 was firstly isolated by ethyl methane sulfonate-induced random mutagenesis. The Chlorella sp. MM-2 grew in the presence of gas containing H2S < 100 ppm, and the growth capacity of the microalgal culture aerated with 80% CH, was similar to 70% that of the control culture (0% CH4). In the field study, CO2 capture efficiency of the Chlorella cultures, at a biomass concentration of 1.2 g L-1, from the desulfurized biogas (-20% CO2, 70% CH4 and H2S < 100 ppm) was approximate 70% on cloudy days and 80% on sunny days. CH4 concentration in the effluent biogas from the Chlorella cultures was increased to approximate 84% on cloudy days and 87% on sunny days from its original 70%. The established outdoor photobioreactor system using a gas cycle-switching operation could be used as a CO2 capture model for biogas upgrading. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
A piezoelectric immunosensor for specific capture and enrichment of viable pathogens by quartz crystal microbalance sensor, followed by detection with antibody-functionalized gold nanoparticles
(2012-10-01)
Guo, Xiao
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Lin, Chih-Sheng
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Chen, Sz-Hau
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Ye, Rebecca
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Wu, Vivian C. H.
A sensitive bacteria enrichment and detection system for viable Escherichia coil O157:H7 was developed using a piezoelectric biosensor-quartz crystal microbalance (QCM) with antibody-functionalized gold nanoparticles (AuNPs) used as detection verifiers and amplifiers. In the circulating-flow QCM system, capture antibodies for E. coil 0157:H7 were first immobilized onto the QCM chip. The sample containing E. coli 0157:H7 was circulated through the system in the presence of 10 ml of brain heart infusion (BHI) broth for 18 h. The cells of E. coli 0157:H7 specifically captured and enriched on the chip surface of the QCM were identified by QCM frequency changes. Listeria monocytogenes and Salmonella Typhimurium were used as negative controls. After bacterial enrichment, detection antibody-functionalized AuNPs were added to enhance the changes in detection signal. The use of BHI enrichment further enhanced the sensitivity of the developed system, achieving a detection limit of 0-1 log CFU/ml or g. The real-time monitoring method for viable E. coli 0157:H7 developed in this study can be used to enrich and detect viable cells simultaneously within 24 h. The unique advantages of the system developed offer great potential in the microbial analysis of food samples in routine settings. (C) 2012 Elsevier B.V. All rights reserved.
A Tiling-Scheme Viterbi Decoder in Software Defined Radio for GPUs
(2011)
Lin, Chih-Sheng
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Liu, Wei-Lun
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Yeh, Wei-Ting
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Chang, Li-Wen
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Hwu, Wen-Mei W.
In this paper, we propose a parallel design of Viterbi decoder for Software-Defined Radio (SDR). Our method implements a divide-and-conquer approach by tiling decoding sequences, performing independent speculated Viterbi decoding, and merging partial candidate paths into the final path. For each independent Viterbi decoding, the best path is selected by calculating Hamming distances trellis-by-trellis in parallel. Our method shows up to 14.6x speedup on an NVIDIA 8800 GTX over a sequential C implementation on a 2.4GHz Intel Core 2 CPU. Also, compared with existing GPU-based implementation in [3], our method outperforms up to 2.5x.
Ability of a mutant strain of the microalga Chlorella sp to capture carbon dioxide for biogas upgrading
(2012-05-01)
Kao, Chien-Ya
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Chiu, Sheng-Yi
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Huang, Tzu-Ting
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Dai, Le
;
Hsu, Ling-Kang
In this study, a culture system with outdoor microalgae-incorporating photobioreactors was utilized to upgrade biogas produced from the anaerobic digestion of swine wastewater. Using ethyl methane sulfonate (EMS) random mutagenesis, we isolated a mutant strain of microalga, Chlorella sp. MB-9, which was tolerant to high CH4 and CO2. In the field study of outdoor operation, the maximum growth rates of Chlorella sp. MB-9 aerated with desulfurized biogas at 0.05, 0.1, 0.2 and 0.3 vvm were 0.32, 0.311, 0.275 and 0.251 g L-1 d(-1). In addition. similar to 70% of the CO2 in desulfurized biogas (similar to 20% CO2. similar to 70% CH4, and H2S < 50 ppm) could be captured by the Chlorella sp. MB-9 cultures. The CH4 concentration in the effluent biogas from the Chlorella cultures increased from its original 70% up to 85-90%. The established outdoor microalgae-incorporating culture system with a gas cycle-switching operation could be efficiently used as a CO2 capture model for biogas upgrading. (C) 2012 Elsevier Ltd. All rights reserved.
Ability of an alkali-tolerant mutant strain of the microalga Chlorella sp AT1 to capture carbon dioxide for increasing carbon dioxide utilization efficiency
(2017-11-01)
Kuo, Chiu-Mei
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Lin, Tsung-Hsien
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Yang, Yi-Chun
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Zhang, Wen-Xin
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Lai, Jinn-Tsyy
An alkali-tolerant Chlorella sp. AT1 mutant strain was screened by NTG mutagenesis. The strain grew well in pH 6-11 media, and the optimal pH for growth was 10. The CO2 utilization efficiencies of Chlorella sp. AT1 cultured with intermittent 10% CO2 aeration for 10, 20 and 30 min at 3-h intervals were approximately 80, 42 and 30%, respectively. In alkaline medium (pH = 11) with intermittent 10% CO2 aeration for 30 min at 3-, 6- and 12-h intervals, the medium pH gradually changed to 10, and the biomass productivities of Chlorella sp. AT1 were 0.987, 0.848 and 0.710 g L-1 d(-1), respectively. When Chlorella sp. AT1 was aerated with 10% CO2 intermittently for 30 min at 3-h intervals in semi-continuous cultivation for 21 days, the biomass concentration and biomass productivity were 4.35 g L-1 and 0.726 g L-1 d(-1), respectively. Our results show that CO2 utilization efficiency can be markedly increased by intermittent CO2 aeration and alkaline media as a CO2-capturing strategy for alkali-tolerant microalga cultivation.
ACE/ACE2 Ratio and MMP-9 Activity as Potential Biomarkers in Tuberculous Pleural Effusions
(2012)
Hsieh, Wen-Yeh
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Kuan, Tang-Ching
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Cheng, Kun-Shan
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Liao, Yan-Chiou
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Chen, Mu-Yuan
Objective: Pleural effusion is common problem, but the rapid and reliable diagnosis for specific pathogenic effusions are lacking. This study aimed to identify the diagnosis based on clinical variables to differentiate pleural tuberculous exudates from other pleural effusions. We also investigated the role of renin-angiotensin system (RAS) and matrix metalloproteinase (MMPs) in the pathogenesis of pleural exudates. Experimental design: The major components in RAS and extracellular matrix metabolism, including angiotensin converting enzyme (ACE), ACE2, MMP-2 and MMP-9 activities, were measured and compared in the patients with transudative (n = 45) and exudative (n = 80) effusions. The exudative effusions were come from the patients with tuberculosis (n = 20), pneumonia (n = 32), and adenocarcinoma (n = 28). Results: Increased ACE and equivalent ACE2 activities, resulting in a significantly increased ACE/ACE2 ratio in exudates, were detected compared to these values in transudates. MMP-9 activity in exudates was significantly higher than that in transudates. The significant correlation between ACE and ACE2 activity that was found in transudates was not found in exudates. Advanced analyses showed significantly increased ACE and MMP-9 activities, and decreased ACE2 activity in tuberculous pleural effusions compared with those in pneumonia and adenocarcinoma effusions. The results indicate that increased ACE and MMP-9 activities found in the exudates were mainly contributed from a higher level of both enzyme activities in the tuberculous pleural effusions. Conclusion: Interplay between ACE and ACE2, essential functions in the RAS, and abnormal regulation of MMP-9 probably play a pivotal role in the development of exudative effusions. Moreover, the ACE/ACE2 ratio combined with MMP-9 activity in pleural fluid may be potential biomarkers for diagnosing tuberculous pleurisy.
Altered expression of FHL1, CARP, TSC-22 and P311 provide insights into complex transcriptional regulation in pacing-induced atrial fibrillation
(2007-03-01)
Chen, Chien-Lung
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Lin, Jiunn-Lee
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Lai, Ling-Ping
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Pan, Chun-Hsu
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Huang, Shoei K. Stephen
Atrial fibrillation (AF) is the most common progressive disease in patients with cardiac arrhythmia. AF is accompanied by complex atrial remodeling and changes in gene expression, but only a limited number of transcriptional regulators have been identified. Using a low-density cDNA array, we identified 31 genes involved in transcriptional regulation, signal transduction or structural components, which were either significantly upregulated or downregulated in porcine atria with fibrillation (induced by rapid atrial pacing at a rate of 400-600 bpm for 4 weeks that was then maintained without pacing for 2 weeks). The genes for four and a half LIM domains protein-1 (FHL1), transforming growth factor-beta (TGF-beta)-stimulated clone 22 (TSC-22), and cardiac ankyrin repeat protein (CARP) were significantly upregulated, and chromosome 5 open reading frame gene 13 (P311) was downregulated in the fibrillating atria. FHL1 and CARP play important regulatory roles in cardiac remodeling by transcriptional regulation and myofilament assembly. Induced mRNA expression of both FHL1 and CARP was also observed when cardiac H9c2 cells were treated with an adrenergic agonist. Increasing TSC-22 and marked P311 deficiency could enhance the activity of TGF-beta signaling and the upregulated TGF-beta 1 and -beta 2 expressions were identified in the fibrillating atria. These results implicate that observed alterations of underlying molecular events were involved in the rapid-pacing induced AF, possibly via activation of the beta-adrenergic and TGF-beta signaling. (c) 2006 Elsevier B.V. All rights reserved.
Alternative Roles of STAT3 and MAPK Signaling Pathways in the MMPs Activation and Progression of Lung Injury Induced by Cigarette Smoke Exposure in ACE2 Knockout Mice
(2016-01-01)
Hung, Yi-Han
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Hsieh, Wen-Yeh
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Hsieh, Jih-Sheng
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Liu, Fon-Chang
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Tsai, Chin-Hung
Inflammation-mediated abnormalities in the renin-angiotensin system (RAS) and expression of matrix metalloproteinases (MMPs) are implicated in the pathogenesis of lung injury. Angiotensin converting enzyme II (ACE2), an angiotensin converting enzyme (ACE) homologue that displays antagonist effects on ACE/angiotensin II (Ang II) axis, could also play a protective role against lung diseases. However, the relationship between ACE2 and MMPs activation in lung injury is still largely unclear. The purpose of this study is to investigate whether MMPs activity could be affected by ACE2 and which ACE2 derived signaling pathways could be also involved via using a mouse model with lung injury induced by cigarette smoke (CS) exposure for 1 to 3 weeks. Wild-type (WT; C57BL/6) and ACE2 KO mice (ACE2(-/-)) were utilized to study CS-induced lung injury. Increases in the resting respiratory rate (RRR), pulmonary immunokines, leukocyte infiltration and bronchial hyperplasia were observed in the CS-exposed mice. Compared to WT mice, more serious physiopathological changes were found in ACE2(-/-) mice in the first week of CS exposure. CS exposure increased pulmonary ACE and ACE2 activities in WT mice, and significantly increased ACE in ACE2(-/-) mice. Furthermore, the activity of pulmonary MMPs was decreased in CS-exposed WT mice, whereas this activity was increased in ACE2(-/-) mice. CS exposure increased the pulmonary p-p38, p-JNK and p-ERK1/2 level in all mice. In ACE2(-/-) mice, a significant increase p-STAT3 signaling was detected; however, no effect was observed on the p-STAT3 level in WT mice. Our results support the hypothesis that ACE2 deficiency influences MMPs activation and STAT3 phosphorylation signaling to promote more pulmonary inflammation in the development of lung injury.
An efficient Photobioreactors/Raceway circulating system combined with alkaline-CO2 capturing medium for microalgal cultivation
(2018-10-01)
Kuo, Chiu-Mei
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Jian, Jhong-Fu
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Sun, Yu-Ling
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Lin, Tsung-Hsien
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Yang, Yi-Chun
High efficiency of microalgal growth and CO2 fixation in a Photobioreactors (PBRs)/Raceway circulating (PsRC) system combined with alkaline-CO2 capturing medium and operation was established and investigated. Compared with a pH 6 medium, the average biomass productivity of Chlorella sp. AT1 cultured in a pH 11 medium at 2L min(-1) circulation rate for 7 days increased by about 2-fold to 0.346g L-1 d(-1). The maximum amount of CO2 fixation and CO2 utilization efficiency of Chlorella sp. AT1 could be obtained at a PBRs to Raceway ratio of 1:10 in an indoor-simulated PsRC system. A similar result was also shown in an outdoor PsRC system with a 10-ton scale for microalgal cultivation. Under the appropriate circulation rate, the stable growth performance of Chlorella sp. AT1 cultured by long-term semi-continuous operation in the 10-ton outdoor PsRC system was observed, and the total amount of CO2 fixation was approximately 1.2kg d(-1) with 50% CO2 utilization efficiency.
An optical biosensing platform for proteinase activity using gold nanoparticles
(2010-08-01)
Chuang, Yao-Chen
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Li, Jung-Chun
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Chen, Sz-Hau
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Liu, Ting-Yu
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Kuo, Ching-Han
The surface plasmon resonance (SPR) wavelength of colloidal gold nanoparticles (AuNPs) can vary when the AuNPs aggregate, have different sizes or shapes, or are modified with chemical molecules. In this study, an optical biosensing platform for a proteinase activity assay was established based on the SPR property of AuNPs. The 13-nm AuNPs were modified with gelatin (AuNPs-gelatin) as a proteinase substrate and subsequently modified with 6-mercaptohexan-1-ol (MCH) (AuNPs/MCH-gelatin). After proteinase (trypsin or gelatinase) digestion, the AuNPs lose shelter, and MCH increases the attractive force between the modified AuNPs. Therefore, the AuNPs gradually move closer to each other, resulting in AuNPs aggregation. The AuNPs aggregation can be monitored by the red shift of surface plasmon absorption and a visible color change of the AuNPs is from red to blue. Such a color change can be observed with the naked eye. For detection, the absorption ratio, A(625)/A(525), of the reacted AuNPs solution can be used to estimate quantitatively the proteinase activity. A linear correlation has been established with trypsin activity at concentrations from 1.25 x 10(-1) to 1.25 x 10(2) U and matrix metalloproteinase-2 activity at concentrations from 50 ng/mL to 600 ng/mL. (C) 2010 Elsevier Ltd. All rights reserved.
Angiotensin II downregulates ACE2-mediated enhancement of MMP-2 activity in human cardiofibroblasts
(2013-12-01)
Kuan, Tang-Ching
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Chen, Mu-Yuan
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Liao, Yan-Chiou
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Ko, Li
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Hong, Yi-Han
Angiotensin converting enzyme II (ACE2) is a component of the renin-angiotensin system (RAS) that negatively regulates angiotensin II (Ang II). Ang II, in turn, affects the expression of matrix metalloproteinases (MMPs) to induce heart remodeling. The specific mechanisms by which ACE2 regulates MMP-2, however, remain unclear. The aim of this study was to investigate the regulatory relationships between Ang II, ACE2, and MMP-2. ACE2 expression was upregulated and downregulated in human cardiofibroblasts (HCFs) by lentiviral infection. Effects on MMP-2 activity, shed ACE2 activity, extracellular signal-regulated kinase (ERK) signaling pathway, and ADAM metallopeptidase domain 17 (ADAM17) expression were assessed. ACE2 increased MMP-2 activity, and Ang II inhibited this effect through the Ang II type-1 receptor (AT1R) and ERK1/2 signaling pathway. Ang II also reduced the effect of ACE2 on ERK1/2 levels, the activity of shed ACE2, and adam17 expression in HCFs. Additionally, these Ang II-mediated reductions could be attenuated by AT1R antagonist valsartan. In conclusion, these data help to clarify how ACE2 and Ang II interact to regulate MMP-2 and control tissue remodeling in heart disease.
Application of cranberry concentrate (Vaccinium macrocarpon) to control Escherichia coli O157:H7 in ground beef and its antimicrobial mechanism related to the downregulated slp, hdeA and cfa
(2009-02-01)
Wu, Vivian C. H.
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Qiu, Xujian
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de los Reyes, Benildo G.
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Lin, Chih-Sheng
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Pan, Yingjie
The possible use of cranberry concentrate (CC) as a natural food preservative was studied by examining its antimicrobial effect on the growth of Escherichia coli O157:H7 inoculated in ground beef, its organoleptical effect oil beef patties, and its antimicrobial mechanism on the gene regulation level. Inoculated ground beef was added with CC and stored at 4 degrees C for 5 days. Bacteria were detected on day 0, 1, 3, and 5. Cranberry concentrate (2.5%, 5%, and 7.5% w/w) reduced total aerobic bacteria 1.5 log, 2.1 log, and 2.7 log CFU/g and E coli O157:H7 0.4 log, 0.7 log, and 2.4 log CFU/g, respectively, when compared to the control on day 5. Fifty panelists evaluated the burgers supplemented with CC. No differences in appearance, flavor, and taste were found among burgers with 0%, 2.5%, and 5% CC. The expression of E coli O157:H7 cyclopropane fatty acyl phospholipid synthase (cfa), hypothetical protein (hdeA), outer membrane porin protein C (ompC), hyperosmotically inducible periplasmic protein (osmY), and outer membrane protein induced after carbon starvation (sip) genes with or without CC (2.5% v/v) treatment was investigated by quantitative real-time PCR. Compared to the control, sip, hdeA, and cfa were markedly downregulated, ompC was slightly downregulated, while osmY was slightly affected. (C) 2008 Elsevier Ltd. All rights reserved.
Aqueous zymography screening of matrix metalloproteinase activity and inhibition based on colorimetric gold nanoparticles
(2012-02-15)
Chuang, Yao-Chen
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Huang, Wei-Ting
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Chiang, Pin-Hsuan
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Tang, Meng-Che
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Lin, Chih-Sheng
An optical gold nanoparticles (AuNPs)-based method was fabricated for the rapid detection of matrix metalloproteinase (MMP) activity and screening potential MMP inhibitors without sophisticated instruments. The diagnosis platform was composed of AuNPs, particular MMP substrates and 6-mercapto-1-hexanol (MCH). The functionalized AuNPs were subjected to specific MMP digestion, and the MMP found the substrate on AuNPs, such that the AuNPs lost shelter and MCH increased the attraction force between AuNPs. Consequently, AuNPs aggregation and a color change from red to purple with increasing MMP concentration were observed. The surface plasmon resonance (SPR) of the formed AuNPs allowed for the quantitative detection of MMP activity. A sensitive linear correlation existed between the absorbance and the activity of the MMPs, which ranged from 10 ng/mL to 700 ng/mL in NTTC buffer and plasma samples. The proposed colorimetric method could be accomplished in a homogeneous solution with one-step operation in 30 min and has been successfully applied to the determination of particular MMP activity in plasma samples, in which the results are consistent with substrate zymography. This technology may become a simple platform for parallel screening a number of inhibitors and offer an alternative method to studying the efficiency of inhibitors for suppressing MMP activity. The absorbance ratio at 625 nm and 525 nm (A(625)/A(525)) confirmed the efficiency of the inhibitors as observed in substrate zymography. The IC50 of ONO-4817 and galardin for MMP-1, MMP-2 and MMP-7 determined by the proposed colorimetric method was similar to the results of substrate zymography. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Bioethanol production from acid pretreated microalgal hydrolysate using microwave-assisted heating wet torrefaction
(2020-11-01)
Yu, Kai Ling
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Chen, Wei-Hsin
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Sheen, Herng-Kuang
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Chang, Jo-Shu
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Lin, Chih-Sheng
This study focused on the bioethanol production from the co-production of solid biochar and liquid hydrolysate under microwave-assisted heating wet torrefaction towards a sustainable green technology. The two indigenous microalgal biomass undergone dilute acid pretreatment using wet torrefaction to produce microalgal hydrolysates and biochar at operating conditions of 160-170 degrees C with holding times of 5-10 min. The hydrolysates were utilized for fermentation with the yeast Saccharomyces cerevisiae at 29 degrees C in a dark condition at a non-agitation state for 120 h. The concentrations of total reducing sugar, reducing sugar by-product, and bioethanol in the hydrolysates were determined. The carbohydrate-rich microalga C. vulgaris ESP-31 showed a good performance in bioethanol production. Microalgal hydrolysate obtained after the pretreatment consisted of a total reducing sugar with the highest concentration of 98.11 g/L. The formation of by-product 5-hydroxymethyl-2-furaldehyde (5 HMF), which might act as the fermentation inhibitor that led to the low ethanol yield, was also analyzed. The highest ethanol yield achieved was 7.61% with a maximum experimental conversion probability of 95.22%. This study has demonstrated the feasible bioethanol production from microalgal hydrolysate through microwave-assisted heating wet torrefaction using dilute acids and the optimization of bioethanol production can be carried out for better performance in the future study.
Characterization of a heat-tolerant Chlorella sp GD mutant with enhanced photosynthetic CO2 fixation efficiency and its implication as lactic acid
(2017-09-12)
Lee, Tse-Min
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Tseng, Yu-Fei
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Cheng, Chieh-Lun
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Chen, Yi-Chuan
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Lin, Chih-Sheng
Background: Fermentative production of lactic acid from algae-based carbohydrates devoid of lignin has attracted great attention for its potential as a suitable alternative substrate compared to lignocellulosic biomass. Results: A Chlorella sp. GD mutant with enhanced thermo-tolerance was obtained by mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine to overcome outdoor high-temperature inhibition and it was used as a feedstock for fermentative lactic acid production. The indoor experiments showed that biomass, reducing sugar content, photosynthetic O-2 evolution rate, photosystem II activity (F-v/F-m and F-v'/F-m'), and chlorophyll content increased as temperature, light intensity, and CO2 concentration increased. The mutant showed similar DIC affinity and initial slope of photosynthetic light response curve (a) as that of the wild type but had higher dissolved inorganic carbon (DIC) utilization capacity and maximum photosynthesis rate (P-max). Moreover, the PSII activity (F-v'/F-m') in the mutant remained normal without acclimation process after being transferred to photobioreactor. This suggests that efficient utilization of incident high light and enhanced carbon fixation with its subsequent flux to carbohydrates accumulation in the mutant contributes to higher sugar and biomass productivity under enriched CO2 condition. The mutant was cultured outdoors in a photobioreactor with 6% CO2 aeration in hot summer season in southern Taiwan. The harvested biomass was subjected to separate hydrolysis and fermentation (SHF) for lactic acid production with carbohydrate concentration equivalent to 20 g/L glucose using the lactic acid-producing bacterium Lactobacillus plantarum 23. The conversion rate and yield of lactic acid were 80% and 0.43 g/g Chlorella biomass, respectively. Conclusions: These results demonstrated that the thermo-tolerant Chlorella mutant with high photosynthetic efficiency and biomass productivity under hot outdoor condition is an efficient fermentative feedstock for large-scale lactic acid production.
Characterization of the thermal-tolerant mutants of Chlorella sp with high growth rate and application in outdoor photobioreactor cultivation
(2010-04-01)
Ong, Seow-Chin
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Kao, Chien-Ya
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Chiu, Sheng-Yi
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Tsai, Ming-Ta
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Lin, Chih-Sheng
In this study, two thermal-tolerant mutants of Chlorella sp. MT-7 and MT-15, were isolated. In indoor cultivation, specific growth rate (mu, d(-1)) of the mutants were 1.4 to 1.8-fold at 25 degrees C and 3.3 to 6.7-fold at 40 C higher than those of wild type. The carbon dioxide fixation rate of both microalgal mutants was also significantly higher than that of wild type. In outdoor closed cultivation, where the temperature of culture broth was 41 +/- 1 degrees C, the mu of mutant strain MT-15 was 0.238 d(-1) during an 8-day cultivation. Whereas, the growth of wild type was inhibited in the outdoor cultivation. Our results show that the isolated microalgal strains are adaptable to be applied in outdoor cultivation in subtropical zones. (C) 2009 Elsevier Ltd. All rights reserved.
Circulating Matrix Metalloproteinase-2 and-9 Enzyme Activities in the Children with Ventricular Septal Defect
(2013)
Cheng, Kun-Shan
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Liao, Yan-Chiou
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Chen, Mu-Yuan
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Kuan, Tang-Ching
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Hong, Yi-Han
Ventricular septal defect (VSD) is the most common form of congenital heart diseases. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases involved in causal cardiac tissue remodeling. We studied the changes of circulating MMP-2 and MMP-9 activities in the patients with VSD severity and closure. There were 96 children with perimembranous VSD enrolled in this study. We assigned the patients into three groups according to the ratio of VSD diameter/diameter of aortic root (Ao). They were classified as below: Trivial (VSD/Ao ratio <= 0.2), Small (0.2 < VSD/Ao <= 0.3) and Median (0.3 < VSD/Ao) group. Plasma MMP-2 and MMP-9 activities were assayed by gelatin zymography. There was a significant higher MMP-2 activity in the VSD (Trivial, Small and Median) groups compared with that in Control group. The plasma MMP-9 activity showed a similar trend as the findings in MMP-2 activity. After one year follow-up, a significant difference in the MMP-9 activity was found between VSD spontaneous closure and non-closure groups. In conclusion, a positive trend between the severity of VSD and activities of MMP-2 and MMP-9 was found. Our data imply that MMP-2 and MMP-9 activities may play a role in the pathogenesis of VSD.
Composite Modified Electrode Strip
(2009-01-08)
Chen, Sz-Hau
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Lin, Chih-Sheng
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Chen, Guan-Tin
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Lin, Yueh-Hui
;
Shen, Thomas Y.S.
The present invention provides a surface-modified electrode strip for measuring an electrochemical signal that is synergistically amplified by means of a nano-scaled gold particle layer and a lipid-soluble electron mediator layer. A biosensor comprising the electrode strip is also provided.