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Effect of Light Intensity and pH on Cell Density Assessed by Spectrophotometry for the Unicellular Algae Chlorella vulgaris
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作者 Nishat Tasnim Debabrata Karmakar +4 位作者 Rakibul Hasan Rashadul Islam Saddam Hossain Aftab Ali Shaikh Rezaul Karim 《American Journal of Plant Sciences》 CAS 2023年第4期472-481,共10页
In this study, an effective environment for Chlorella vulgaris growth is sought after. As a substitute source of food and feed, increasing the cell density of Chlorella culture is one of the keys to ensuring sustainab... In this study, an effective environment for Chlorella vulgaris growth is sought after. As a substitute source of food and feed, increasing the cell density of Chlorella culture is one of the keys to ensuring sustainability. It can be showed from different studies that optimum light intensity and pH could increase cell density. In this study, the effects of light and pH on the growth rate of C. vulgaris were observed in photobioreactor. A specific wavelength (682 nm) was determined by UV-Vis Spectrophotometry to carry out the further analysis. The light intensities were set at 7409, 9261 and 11,113 lux;pH values were set at 7, 8 and 9 respectively. The experimental results depicted the light intensity of 9261 lux as the best due to the higher number of cells (48.56 × 10<sup>6</sup> cells/mL) obtained using this intensity. In terms of pH, without pH control, cell numbers were found to be highest under the light intensity of 9261 lux. When pH was controlled, it was found that under the optimum light intensity, pH control between 7.0 and 7.5 was the optimum range for the growth of C. vulgaris. Moreover, this method of study may possibly be a promising source of low cost culture for Chlorella vulgaris. 展开更多
关键词 Chlorella vulgaris Light Intensity PH cell density
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Corneal endothelial cell density and morphology in low and moderate myopic Chinese eyes 被引量:5
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作者 Samaneh Delshad Jane Mei Chun 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2013年第4期467-470,共4页
AIM:To describe and compare the corneal endothelial cell density and morphology in young,low and moderate myopic Chinese adults in Malaysian Chinese population.·METHODS:Non-contact specular microscopy(Topcon SP30... AIM:To describe and compare the corneal endothelial cell density and morphology in young,low and moderate myopic Chinese adults in Malaysian Chinese population.·METHODS:Non-contact specular microscopy(Topcon SP3000P,Tokyo,Japan) was performed in low(n =78;21.22±1.51 years) and moderate(n =78;21.82±1.40 years)myopic subjects.The mean of three consecutive measurements of endothelial cell density(MCD),coefficient of variation(CV) in the cell size,and hexagonal appearance of the cell were obtained.·RESULTS:In low myopic eyes the MCD was 3 063.0±176.2/mm2,the mean CV was 33.4 ±4.0% and the mean hexagonal appearance of the cell was 57.9 ±2.7%.In moderate myopic eyes the MCD was 2961.6 ±159.0/mm2,the mean CV was 33.9 ±3.6% and mean hexagonal appearance of the cell was 56.2 ±4.7%.There were statistically significant differences in MCD(P 【0.000) and hexagonal appearance of the cell(P 【0.005) between low and moderate myopic eyes.·CONCLUSION:The corneal endothelial cell layer in more myopic eyes tends to have less MCD and cell hexagonality compared to lower myopic eyes.Nevertheless,there is no significant difference in CV between low and moderate myopic eyes. 展开更多
关键词 CORNEA myopic eyes specular microscopy endothelial cell density MORPHOLOGY
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Visual acuity and endothelial cell density with respect to the graft thickness in Descemet's stripping automated endothelial keratoplasty: one year results 被引量:3
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作者 Banu Torun Acar Mehmet Orcun Akdemir Suphi Acar 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2014年第6期974-979,共6页
AIM: To evaluate the visual acuity and endothelial cell density according to the thickness in Descemet’s stripping automated endothelial keratoplasty(DSAEK)one year after surgery.METHODS: DSAEK patients’ data were r... AIM: To evaluate the visual acuity and endothelial cell density according to the thickness in Descemet’s stripping automated endothelial keratoplasty(DSAEK)one year after surgery.METHODS: DSAEK patients’ data were reviewed. Thirty seven eyes of 37 patients who underwent DSAEK for pseudophakic bullous keratopathy(PBK) were included in this study. Graft thickness was measured with optical coherence tomography(OCT) 12 mo after DSAEK. Eyes were divided into 3 groups based on the graft thickness:thick(】200 μm), medium-thick(150-200 μm) and thin(【150 μm). Best corrected visual acuity(BCVA),endothelial cells density(ECD) and complications were assessed and comparisons were done between groups.RESULTS: Median thickness of postoperative grafts was 188(range 73-317 μm). There was no significant difference in age, sex, preoperative BCVA, or follow-up period between DSAEK groups. At postoperative 12 mo,mean BCVA was 0.28±0.10 in thick graft group, 0.52±0.08 in medium-thick graft group, and 0.72 ±0.06 in thin graft group. Thin grafts showed better postoperative BCVA as compared with the medium-thick and thick grafts(P =0.001). Thick graft group had 1637.44 ±88.19-mm2,medium thick graft had 1764.50±34.28-mm2 and thin graft group had 1845.30 ±65.62-mm2. Thin graft group had better ECD at 12 mo after surgery(P =0.001).CONCLUSION: Thin grafts after DSAEK ensure better visual rehabilitation. Eyes with thin grafts had significantly lesser loss of ECD compared to eyes withmedium-thick and thick grafts one year after surgery. 展开更多
关键词 Corneal endothelial cell density Descemet's stripping endothelial keratoplasty graft thickness visual acuity
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Corneal endothelial cell density and morphology in Chinese patients with pseudoexfoliation syndrome 被引量:3
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作者 Meng Wang, Xiao-Guang Dong 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第2期186-189,共4页
AIM: To evaluate the corneal endothelial cell density and morphology in Chinese patients with pseudoexfoliation syndrome (PEX). METHODS: Medical records of 16 patients (20 eyes) with PEX who presented to our instituti... AIM: To evaluate the corneal endothelial cell density and morphology in Chinese patients with pseudoexfoliation syndrome (PEX). METHODS: Medical records of 16 patients (20 eyes) with PEX who presented to our institution between July 2008 and June 2010 were retrospectively reviewed. Thirteen eyes had combined glaucoma. The information of five apparently normal fellow eyes in these patients was also recorded. Left eyes of 20 patients with bilateral senile cataracts but no other eye disease were included as controls. Specular microscopy was performed in all eyes to analyze for corneal endothelial cell density and morphology. Cell density, coefficient of variation in cell size, and percentage of hexagonal cells in corneal endothelium were evaluated. RESULTS: The mean corneal endothelial cell density in the PEX eyes was 2298+/- 239 cells/mm(2), significantly lower than that in the cataract eyes (2652+/- 18 cells/mm(2), P=0.026), but there were no significant differences in coefficient of variation of cell size and frequency of hexagonality between these two groups. No significant differences in the three parameters were found between the apparently normal fellow eyes and the PEX eyes or the cataract eyes, or between the PEX eyes with and without glaucoma. CONCLUSION: Corneal endothelial cell density may decrease in Chinese patients with PEX. The development of glaucoma in PEX eyes does not seem to be related with the change in corneal endothelial cell density or morphology. 展开更多
关键词 corneal endothelial cell density pseudoexfoliation syndrome corneal morphology
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Corneal endothelial cell density and morphology and central corneal thickness in Guangxi Maonan and Han adolescent students of China 被引量:2
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作者 Hao Liang Hui-Yi Zuo +6 位作者 Jin-Mao Chen Jie Cai Yu-Zhua Qin Yu-Ping Huang Ying-Ying Chen Dong-Yong Tang Shao-Jian Tan 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第3期608-611,共4页
AIM: To investigate the corneal endothelial cell density and morphology and central corneal thickness in the Guangxi Maonan and Han adolescent students of China.METHODS: Noncontact specular microscope(Topcon SP3000 P,... AIM: To investigate the corneal endothelial cell density and morphology and central corneal thickness in the Guangxi Maonan and Han adolescent students of China.METHODS: Noncontact specular microscope(Topcon SP3000 P, Tokyo, Japan) was performed in 133 adolescent students of Maonan ethnic group(M:F 54:79)and 105 adolescent students of Han ethnic group(M:F 50:55),5 to 20 y of age, who were randomly selected from 3schools in Huanjiang Maonan Autonomous County of Guangxi Zhuang Autonomous Region of China.Parameters studied included endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness. RESULTS: Endothelial cell density, mean cell area,coefficient of variation in cell size, percentage hexagonality and central corneal thickness in the study population were(2969.50 ±253.93) cells/mm2,(339.23 ±29.44) μm2,(29.96 ±4.07) %,(64.58 ±9.41) % and(523.71 ±32.82) μm in Maonan and(2998.26 ±262.65) cells/mm2,(336.11±30.07) μm2,(29.89±5.03) %,(64.91±11.64) % and(524.39 ±33.15) μm in Han, respectively. No significant differences were observed in endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness between Maonan and Han(P =0.615, 0.659, 0.528, 0.551,0.999). In Maonan and Han, we found age was negatively correlated with endothelial cell density and percentagehexagonality and positively correlated with mean cell area and coefficient of variation in cell size. Negative correlation was also found between central corneal thickness and age in Han, whereas no correlation was found in Maonan. CONCLUSION: There were no differences between Maonan and Han in corneal endothelial cell density and morphology and central corneal thickness. In these two ethnic groups, there were statistically significant decrease in endothelial cell density and percentage hexagonality with increasing age and statistically significant increase in cell area and coefficient of variation in cell size with increasing age. Central corneal thinned with increasing age in Han, whereas difference did not attain statistical significance in Maonan. 展开更多
关键词 endothelial cell density MORPHOLOGY central corneal thickness Maonan
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Changes in endothelial cell density following penetrating keratoplasty and deep anterior lamellar keratoplasty 被引量:1
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作者 Banu Torun Acar Ece Turan Vural Suphi Acar 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2011年第6期644-647,共4页
· AIM: To compare the corneal endothelial cell density (ECD) of clear grafts after penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). · METHODS: The study included 44 and 54 patien... · AIM: To compare the corneal endothelial cell density (ECD) of clear grafts after penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). · METHODS: The study included 44 and 54 patients treated with PK and DALK, respectively, between March 2006 and April 2010. Corneal ECD was examined using specular microscopy at postoperative 1, 3, 6, 12, and 18 months, and the values were compared. · RESULTS: Corneal ECD reduction in the PK group was 7.4%, 15.2%, 23.5%, and 28.9% at 3, 6, 12 and 18 months respectively after surgery, compared with 4.2 % in the first month (P <0.01). These figures were 3.0%, 6.7%, 7.2%, and 7.7% at 3, 6, 12 and 18 months respectively, compared with 2.2 % in the first month in the DALK group (P >0.05). · CONCLUSION: Compared with DALK,PK significantly reduced ECD of the clear grafts. These results suggest that survival of endothelial cells in grafts is better after DALK than after PK. · 展开更多
关键词 lamellar keratoplasty penetrating keratoplasty endothelial cell density specular microscopy
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Consideration of transmembrane water exchange in pharmacokinetic model significantly improves the accuracy of DCE-MRI in estimating cellular density:A pilot study in glioblastoma multiforme
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作者 Zhenfeng Pang Zejun Wang +5 位作者 Bao Wang Kaiyue Guo Cheng Meng Yingchao Liu Xueqian Kong Ruiliang Bai 《Magnetic Resonance Letters》 2022年第4期243-254,共12页
Transmembrane water exchange(TWE)including transcytolemmal water exchange and transvascular water exchange is involved in many in vivo measurements and makes different contributions to the measuring results.In this st... Transmembrane water exchange(TWE)including transcytolemmal water exchange and transvascular water exchange is involved in many in vivo measurements and makes different contributions to the measuring results.In this study,we focus on the potential influence of TWE on the cell density parameter,intracellular water mole fraction pi,derived by dynamic contrast enhanced-magnetic resonance imaging(DCE-MRI)which has been reported as a technique to characterize perfusion and vascularization of tissues,but its accuracy in measuring cell density(or interstitial space)has been questioned.Sixteen patients with glioblastoma multiforme(GBM)were enrolled since GBM shows strong intratumor heterogeneity in both cell density and TWE.All the subjects were collected with DCE-MRI and apparent diffusion coefficient(ADC)map.The latter was considered as a valid surrogate of cell density.Extended Tofts(eTofts)model considering TWE as infinitely large variables and shutter-speed model(SSM)considering TWE as finite ones were used to fit DCE-MRI data.Monte Carlo(MC)and finite difference(FD)methods were used to simulate the influence of TWE on DCE-MRI-derived pi and ADC,respectively.The eTofts model shows a significant overestimation of pi in comparison with SSM in GBM(P<0.001),which is in accordance with MC simulations,and this overestimation shows dependence on the intra-to-extracellular water exchange rate constant(kio).Significant negative correlations between ADC and SSM-derived pi were found in both voxel-wise analyses(t-test P<0.001,average r=-0.74)and inter-subject comparisons(r=-0.63,P=0.009).But no consistent voxel-wise correlations(P>0.05)and a weaker inter-subject negative correlation(r=-0.56,P=0.02)were found between ADC and eTofts-derived pi.Further experimental and FD results revealed that kio made a limited contribution to ADC values in the physiological kio range in GBM,supporting ADC as a valid biomarker of cell density.These results suggest that the DCE-MRI pharmacokinetic shutter-speed model could significantly improve its accuracy in cell density estimation because of the considering transmembrane water exchange. 展开更多
关键词 DCE-MRI cell density Transcytolemmal water exchange Finite difference simulation Glioblastoma multiforme
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Destructive effects on endothelial cells of grafts in cytomegalovirus DNA-positive patients after keratoplasty
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作者 Yun-Xiao Zang Rong-Mei Peng +6 位作者 Han-Zhi Ben Jing-Hao Qu Ge-Ge Xiao Li-Xue Shuai Pei Zhang Li-Na Feng Jing Hong 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第1期53-59,共7页
AIM:To investigate corneal graft survival rate and endothelial cell density(ECD)loss after keratoplasty in cytomegalovirus(CMV)positive patients.METHODS:This was a retrospective cohort study.We analyzed the clinical d... AIM:To investigate corneal graft survival rate and endothelial cell density(ECD)loss after keratoplasty in cytomegalovirus(CMV)positive patients.METHODS:This was a retrospective cohort study.We analyzed the clinical data of patients who underwent viral DNA detection in aqueous humor/corneal tissue collected during keratoplasty from March 2015 to December 2018 at the Peking University Third Hospital,Beijing,China.To further evaluate the effect of CMV on graft survival rate and ECD loss,patients were divided into three groups:1)CMV DNA positive(CMV+)group;2)viral DNA negative(virus-)group,comprising virus-group eyes pairwise matched to eyes in the CMV+group according to ocular comorbidities;3)control group,comprising virus-group eyes without ocular comorbidities.The follow-up indicators including graft survival rate,ECD,ECD loss,and central corneal thickness(CCT),were analyzed by Tukey honestly significant difference(HSD)test.RESULTS:Each group included 29 cases.The graft survival rate in CMV+group were lowest among the three groups(P=0.000).No significant difference in donor graft ECD was found among three groups(P=0.54).ECD in the CMV+group was lower than the virus-group at 12(P=0.009),and 24mo(P=0.002)after keratoplasties.Furthermore,ECD loss was higher in the CMV+group than in the virus-group in the middle stage(6-12mo)postkeratoplasty(P=0.017),and significantly higher in the early stage(0-6mo)in the virus-group than in the control group(P=0.000).CONCLUSION:CMV reduces the graft survival rate and exerts persistent detrimental effects on the ECD after keratoplasty.The graft ECD loss associate with CMV infection mainly occurrs in the middle stage(6-12mo postoperatively),while ocular comorbidities mainly affects ECD in the early stage(0-6mo postoperatively). 展开更多
关键词 KERATOPLASTY CYTOMEGALOVIRUS ocular comorbidities endothelial cell density central corneal thickness
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Expression of Maspin in Non-small Cell Lung Cancer and Its Relationship to Vasculogenic Mimicry 被引量:18
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作者 武世伍 俞岚 +3 位作者 承泽农 宋文庆 周蕾 陶仪声 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2012年第3期346-352,共7页
Maspin belongs to the serine protease inhibitor (serpin) family and has been proven to be a suppressor of tumor growth and metastasis in many types of tumors. The purpose of this study was to investigate the express... Maspin belongs to the serine protease inhibitor (serpin) family and has been proven to be a suppressor of tumor growth and metastasis in many types of tumors. The purpose of this study was to investigate the expression of maspin in non-small cell lung cancer (NSCLC) and its relationship to vasculogenic mimicry (VM). A total of 160 specimens of NSCLC were involved in this study and 20 specimens of normal lung tissue served as controls. VM, microvessel density (MVD) and the expression of maspin were detected by using immunohistochemical staining. The results showed that the positive rates of maspin and VM in the NSCLC group were 48.1% (77/160) and 36.9% (59/160), respectively, which were significantly different from those in the control group with the positive rates of maspin and VM being 100% and 0% respectively (P〈0.05). VM, MVD and the expression level of maspin were significantly related to tumor differentiation, lymph node metastasis, clinical stages and postoperative survival time (all P〈0.05). The maspin expression in patients with squamous cell carcinoma was significantly higher than that in those with adenocarcinoma (P〈0.05). The maspin expression was negatively correlated with VM and MVD, and there was a positive correlation between VM and MVD. Maspin-negative expression, VM and high MVD score were negatively related to the 5-year-survival rate. PTNM stages, VM, MVD and maspin expression were independent prognostic factors for NSCLC (P〈0.05). It was suggested that the loss of expression of maspin may participate in the invasion and metastasis of NSCLC and it has a positive relationship to VM in NSCLC. Combined detection of maspin, VM and MVD may help predict the progression and prognosis of NSCLC. 展开更多
关键词 non-small cell lung cancer maspin vasculogenic mimicry microvessel density prognosis
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Effect of torsional mode phacoemulsification on cornea in eyes with/without pseudoexfoliation 被引量:3
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作者 Süleyman Demircan Mustafa Atas Yusufcan Yurtsever 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第2期281-287,共7页
AIM: To evaluate the effect of torsional mode phacoemulsification on central corneal thickness, corneal endothelial cell density, and morphology in eyes with/without pseudoexfoliation(PEX) syndrome.METHODS: Fourty-two... AIM: To evaluate the effect of torsional mode phacoemulsification on central corneal thickness, corneal endothelial cell density, and morphology in eyes with/without pseudoexfoliation(PEX) syndrome.METHODS: Fourty-two consecutive patients with and42 patients without PEX as a control group scheduled for cataract surgery was studied. Phacoemulsification, using OZi L IP system, was performed with quick chop technique. Using noncontact specular microscopy, the central endothelial cell density(ECD), coefficient of variation, percentage of hexagonal cells, and the central corneal thickness(CCT) were evaluated preoperatively and postoperatively at 1, 7 and 30 d.RESULTS: The ECD in PEX syndrome was statistically significantly lower than that in the control group preoperatively and postoperatively(P ≤0.001).Percentage change in ECD was statistically significantly higher in PEX than that in control group after surgery follow up(P ≤0.04).There was no statistically significant difference between both groups comparing percentage of hexagonal cells and coefficient of variation in the cell size before and after the surgery. At 1 and 7d after surgery, percentage change in CCT was statistically significantly higher in PEX group than that in the control group(P ≤0.041).CONCLUSION: Although torsional mode phacoemulsification and intraocular lens(IOL) implantation provided a safe and favorable surgical outcome in patients with/without PEX, torsional phacoemulsification led to significantly higher ECD loss in the PEX group than that in the control group during the whole follow up period.In addition, more corneal swelling in the PEX group than that in the control group during the early postoperative period has indicated that the corneal endothelium, in presence of PEX endotheliopathy, seems to be more susceptible to the effects of phacoemulsification surgeryin eyes with PEX. The increased risk of anterior chamber manipulations in patients with PEX should be taken into account for an increased risk of bullous keratopathy. 展开更多
关键词 pseudoexfoliation syndrome endothelial cell density endothelial morphology torsional mode phacoemulsification corneal endothelium
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Effects of Various Light-Emitting Diode(LED)Wavelengths on the Growth of Scenedesmus Obliquus Fachb-12 and Accumulation of Astaxanthin 被引量:1
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作者 Huabing Xu Xiaojuan Liu +3 位作者 Zhiping Mei Jinchun Lin Stephan Aaron Hong Du 《Phyton-International Journal of Experimental Botany》 SCIE 2019年第3期335-348,共14页
Given the central role of light in the algal photosynthesis,respiration,cell division,growth and the accumulation of value products,the effects of light-emitting diodes(LEDs)light wavelengths(blue,white,red and green)... Given the central role of light in the algal photosynthesis,respiration,cell division,growth and the accumulation of value products,the effects of light-emitting diodes(LEDs)light wavelengths(blue,white,red and green)were studied in Scenedesmus obliquus.Biomass,residual nutrient amount,soluble protein,astaxanthin and reactive oxygen species,superoxide dismutase(SOD),catalase(CAT)and peroxidase(POD)activity were analyzed to determine the effects of different monochromatic light wavelengths via biochemical methods.The results showed that blue light wavelength is the optimal light wavelength for phosphorus removal efficiency and the accumulation of biomass and astaxanthin in S.obliquus.Meanwhile,high reactive oxygen species content under the blue light might induce the accumulation of astaxanthin.The high activity of SOD,CAT and POD might participate in clearing the reactive oxygen species to facilitate the growth of microalgae.Furthermore,we found mixed blue/green lights treatment is the most appropriate mixture for the nitrogen removal.Under the blue light treatment,high light intensity and 18L:6D light cycle is the best condition for biomass and astaxanthin accumulation.Optimal nitrogen/phosphorus removal efficiency was observed under a 24L:0D light cycle.These results might provide a foundational data for the optimizing the productivity of high-value metabolites and treatment of wastewater. 展开更多
关键词 Light-emitting diodes WAVELENGTH cell density nutrient removal efficiency ASTAXANTHIN
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Temporal and Spatial Distribution of Nutrients and HABs at Coastal Water of Kota Belud, Sabah 被引量:2
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作者 Sujjat Al Azad Sitti Raehanah Muhamad Shaleh Tan Kar Soon 《Advances in Bioscience and Biotechnology》 2016年第5期233-242,共10页
A study was carried out to determine the temporal and spatial distribution of nutrients and Harmful Algal Blooming species (HABs) to establish the relationship between nutrient concentrations and HABs density in the c... A study was carried out to determine the temporal and spatial distribution of nutrients and Harmful Algal Blooming species (HABs) to establish the relationship between nutrient concentrations and HABs density in the coastal water of Kota Belud, Sabah, Malaysia. Eight stations were set up in four transects (each transect had two stations;one 500 meters seawards from shoreline, and another five kilometers seawards from shoreline) along the Kota Belud coastal area. Phytoplankton samples, water samples and in situ environmental parameters were collected during dry and wet seasons. Altogether nine HABs species were identified from the study area, where six species (Pyrodinium bahamense, Prorocentum micans, Neoceratium furca, Prorocentum sigmoides, Dinophysis caudate, and Neoceratium fursus) belonged to Dinophyceae and three species (Thalassionema nitzchoioides, Chatoceros affinis, Rhizosolenia sp.) belonged to Bacillariophyceae. Among nine species, Chatoceros affinis was the most abundance composed of 80.6% of total species recorded from all stations during study period. Among the toxic producing Dinoflagellate, Pyrodinium bahamense bloom (>10<sup>3</sup> cells/l) was observed during study period. Trong linear relationship (r<sup>2</sup> = 0.80) was observed between the cell density and concentration of nitrate nitrogen. Relationship between cell density and phosphate phosphorus was poor (r<sup>2</sup> = 0.51). The study showed that increasing in nutrient concentrations resulted in the increasing of HABs density. Nitrate was seen to be more important than phosphate in Kota Belud water as limiting factor of the growth of HABs. 展开更多
关键词 HABs cell density NITRATE PHOSPHATE Kota Belud’s Coastal Water Nutrients Concentration PHYTOPLANKTON
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A survey of corneal changes caused by daily wear silicone hydrogel contact lenses
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作者 Beata Kettesy Julianna Vardai +2 位作者 Andras Berta Laszlo Modis Jr. Adam Kemeny-Beke 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2015年第6期92-100,共9页
The examination of the effects of second generation lotra filcon B silicone hydrogel(SiH)lenses on the cornea when worn for three years of daily wear.Material and Methods:55 healthy patients were divided into two grou... The examination of the effects of second generation lotra filcon B silicone hydrogel(SiH)lenses on the cornea when worn for three years of daily wear.Material and Methods:55 healthy patients were divided into two groups:current hydrogel contact lens wearers refitted with lotrafilcon B lenses(Group 1;28 patients)and neophyte contact lens wearers(Group 2;27 patients).Each patient's subjective eye comfort was measured with a self-administered questionnaire.The corneas were analyzed using contact specular microscope to measure corneal thickness and the endothelium before the SiH lenses werefitted after four weeks,one month,six months,one year,two years,and three years of lens wear.Results:Subjective complaints of patients in Group 1 were reduced;however patients in Group 2 experienced discomfort during the first two to four weeks of use.In Group 1,objective examinations identified a decrease in endothelial cell density.In Group 2,the endothelial cell density increased slightly in the first two years but decreased after three years.The results indicate that lotra filcon B slows down the deleterious effects of contact lenses.The coe±cient of variation significantly decreased after six months in Group 1(0.47 vs 0.44;p?0:049),whereas,in Group 2,the hexagonal cells improved significantly after one month(27.78 vs 28.25;p=0.025).Conclusion:Based on the subjects involved and the period of time under examination,it can be concluded that high-Dk SiH lenses support the physiological metabolism and functions of the cornea by improving oxygen provision. 展开更多
关键词 Contact lens corneal endothelium silicone hydrogels specular microscopy cell density
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Recent theoretical progress in the development of perovskite photovoltaic materials 被引量:1
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作者 Xin Zhou Joanna Jankowska +1 位作者 Hao Dong Oleg V.Prezhdo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2018年第3期637-649,共13页
Since the seminal work by Kojima et al. in 2009, solar cells based on hybrid organic-inorganic perovskites have attracted considerable attention and experienced an exponential growth, with photovoltaic efficiencies as... Since the seminal work by Kojima et al. in 2009, solar cells based on hybrid organic-inorganic perovskites have attracted considerable attention and experienced an exponential growth, with photovoltaic efficiencies as of today reaching above 22%. Despite such an impressive development, some key scientific issues of these materials, including the presence of toxic lead, the poor long-term device stability under heat and humidity conditions, and the anomalous hysteresis of the current-voltage curves shown by various solar cell devices, still remain unsolved and constitute an important focus of experimental and theoretical researchers throughout the world. Density functional theory calculations have been successfully applied to exploring structural and electronic properties of semiconductors, complementing the experimental results in search and discovery of novel functional materials. In this review, we summarize the current progress in perovskite photovoltaic materials from a theoretical perspective. We discuss design of lead-free perovskite materials, humidity-induced degradation mechanisms and possible origins for the observed solar cell hysteresis, and assess future research directions for advanced perovskite solar cells based on computational materials design and theoretical understanding of intrinsic properties. 展开更多
关键词 Solar cells Perovskite materials density functional theory
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Influence of band gap of p-type hydrogenated nanocrystalline silicon layer on the short-circuit current density in thin-film silicon solar cells 被引量:1
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作者 Shuwei Zhang Xiangbo Zeng 《Journal of Semiconductors》 EI CAS CSCD 2017年第11期76-80,共5页
The impact of the optical band gap(Eg) of a p-type hydrogenated nanocrystalline silicon layer on the short-circuit current density(Jsc) of a thin-film silicon solar cell is assessed. We have found that the Jsc rea... The impact of the optical band gap(Eg) of a p-type hydrogenated nanocrystalline silicon layer on the short-circuit current density(Jsc) of a thin-film silicon solar cell is assessed. We have found that the Jsc reaches maximum when the Eg reaches optimum. The reason for the Jsc on Eg needs to be clarified. Our results exhibit that maximum Jsc is the balance between dark current and photocurrent. We show here that this dark current results from the density of defects in the p-layer and the barrier at the interface between p-and i-layers. An optimum cell can be designed by optimizing the p-layer via reducing the density of defects in the p-layer and the barrier at the p/i interface. Finally, a 6.6% increase in Jsc was obtained at optimum Eg for n-i-p solar cells. 展开更多
关键词 nanocrystalline silicon band gap p-layer short-circuit current density solar cells
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METABOLISM -OF LOW DENSITY LIPOPROTEIN-DEPENDENT UNSATURATED FATTY ACID IN CULTURED CELLS
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作者 Yizhun Zhu. Shanhong Huang and Zhao Bin1. Research Laboratory of Internal Medicine, Department of Medicine. University Heidelberg, 69115 Heidelberg 2. Institute of Anatomy, Platelet Research Unit, University Munster, 48149 Munster. Germany 《Chinese Medical Journal》 SCIE CAS CSCD 1995年第3期81-82,共2页
The traditional view of the regulation of eicosanoid formation holds that agonists have to activate receptor-coupled phospholipases before eicosanoid syntheiss can be initiated. Action of phospholipases results in an ... The traditional view of the regulation of eicosanoid formation holds that agonists have to activate receptor-coupled phospholipases before eicosanoid syntheiss can be initiated. Action of phospholipases results in an increase in the intracellular concentration of unesterified arachidonic acid (AA). Once unesterified AA is present in sufficient amounts it can be metabolized by a variety of enzymes that catalyze 展开更多
关键词 METABOLISM OF LOW density LIPOPROTEIN-DEPENDENT UNSATURATED FATTY ACID IN CULTURED cellS ACID
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Influence and mechanism of N-(3-oxooxtanoyl)-L-homoserine lactone(C_8-oxo-HSL) on biofilm behaviors at early stage 被引量:4
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作者 Siqing Xia Lijie Zhou +1 位作者 Zhiqiang Zhang Jixiang Li 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第12期2035-2040,共6页
N-acyl-homoserines quenching, enzymatic quenching of bacterial quorum sensing, has recently applied to mitigate biofilm in membrane bioreactor. However, the effect of AHLs on the behavior of biofilm formation is still... N-acyl-homoserines quenching, enzymatic quenching of bacterial quorum sensing, has recently applied to mitigate biofilm in membrane bioreactor. However, the effect of AHLs on the behavior of biofilm formation is still sparse. In this study, Pseudomonas aeruginosa biofilm was formed on ultra-filtration membrane under a series of N-(3-0xooxtanoyl)-L-homoserine lactone (C8-0xo-HSL) concentrations. Diffusing Cs-oxo-HSL increased the growth rate of cells on biofilm where the concentration of Cs-oxo-HSL was over 10-7 g/L. The C8-0xo-HSL gradient had no observable influence on cell density and extracellular polymeric substances of biofilm with over 10-7 g/L Cs-oxo-HSL. Surprisingly, 10-11-10-8 g/L of Cs-Oxo-HSL had no effect on cell growth in liquid culture. The cell analysis demonstrated that the quorum sensing system might enhance the growth of neighboring cells in contact with surfaces into biofilm and may influence the structure and organization of biofilm. 展开更多
关键词 quorum sensing C8-oxo-HSL biofilm formation ultra-filtration membrane cell density extracellular polymericsubstances
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Optimizing a nitrogen-supplemented, condensed corn soluble medium for growth of the Polyhydroxyalkanoate producer Pseudomonas putida KT217 被引量:1
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作者 Jeremy Javers William Gibbons Chinnadurai Karunanithy 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2012年第4期62-67,共6页
Pseudomonas putida KT217 produces medium-chain-length polyhydroxyalkanoate(mcl-PHA)that is of commercial interest as a biodegradable plastic.To reduce PHA production costs,a less expensive medium to grow P.putida KT21... Pseudomonas putida KT217 produces medium-chain-length polyhydroxyalkanoate(mcl-PHA)that is of commercial interest as a biodegradable plastic.To reduce PHA production costs,a less expensive medium to grow P.putida KT217 to a high cell dry weight(CDW)was developed.P.putida KT217 was grown in aerated shake flasks on a condensed corn solubles(CCS)based medium that provided several organic acids and carbohydrates that were utilized for growth.The medium was prepared by adding various amounts of fresh CCS(100-600 g/L,or 34.9-209.4 g/L dry basis)to water and then centrifuging and filtering.The CCS permeate media contained dry matter levels of 28.8-164.9 g/L.The CCS permeate medium containing 108.4 g/L solids produced approximately 6 g CDW/L,at a growth rate of 1.03 per hour,and maximum cell population of 4×109 CFU/mL.Because CCS is low in nitrogen,ammonium hydroxide was added at a level of 1.73 g/L,and this significantly increased the CDW(>20 g/L)produced in an aerated bioreactor.Therefore,a nitrogen supplemented CCS medium could provide a cheap source of nutrients for production of P.putida KT217 and PHA. 展开更多
关键词 cell density cell dry weight(CDW) biodegradable plastic biocreator pH nitrogen supplement growth rate
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A non-aqueous Li/organosulfur semi-solid flow battery 被引量:2
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作者 Chenhui Wang Qinzhi Lai +2 位作者 Pengcheng Xu Xianfeng Li Huamin Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2018年第5期716-718,共3页
Non-aqueous flow batteries have attracted extensive attention due to the advantages of wide voltagewindow, high energy density and wide operating temperature and so on. Herein, tetramethylthiuramdisulfide (TMTD) wit... Non-aqueous flow batteries have attracted extensive attention due to the advantages of wide voltagewindow, high energy density and wide operating temperature and so on. Herein, tetramethylthiuramdisulfide (TMTD) with high intrinsic capacity (223 mAh/g) and high solubility (-1 mol/L in chloroform) isinvestigated as the positive active material of the non-aqueous LiJdisulfide semi-solid flow battery. Theelectrochemical activity and reversibility are investigated by cyclic voltammetry and linear scanvoltammetry. This Li/TMTD battery with a high cell voltage of 3.36 V achieves coulombic efficiency of 99%,voltage efficiency of 73% and energy efficiency of 72% at the current density of 5 mA/cm2 with activematerial concentration of 0.1 mol/L. Moreover, the LiJTMTD battery can operate for 100 cycles withoutobvious efficiency decay, indicating good stability. 展开更多
关键词 Energy storage Batteries Organosulfur High energy density High cell voltage
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