scholarly journals Two-Stage Fermentation of Lipomyces starkeyi for Production of Microbial Lipids and Biodiesel

2021 ◽  
Vol 9 (8) ◽  
pp. 1724
Author(s):  
Le Zhang ◽  
Ee Yang Lim ◽  
Kai-Chee Loh ◽  
Yanjun Dai ◽  
Yen Wah Tong
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Operating Cost ◽  
Total Carbon ◽  
Yeast Cells ◽  
Microbial Lipids ◽  
Lipomyces Starkeyi ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference

The high operating cost is currently a limitation to industrialize microbial lipids production by the yeast Lipomyces starkeyi. To explore economic fermentation technology, the two-stage fermentation of Lipomyces starkeyi using yeast extract peptone dextrose (YPD) medium, orange peel (OP) hydrolysate medium, and their mixed medium were investigated for seven days by monitoring OD600 values, pH values, cell growth status, C/N ratios, total carbon concentration, total nitrogen concentration, residual sugar concentration, lipid content, lipid titer, and fatty acids profiles of lipids. The results showed that two-stage fermentation with YPD and 50% YPD + 50% OP medium contributed to lipid accumulation, leading to larger internal lipid droplets in the yeast cells. However, the cells in pure OP hydrolysate grew abnormally, showing skinny and angular shapes. Compared to the one-stage fermentation, the two-stage fermentation enhanced lipid contents by 18.5%, 27.1%, and 21.4% in the flasks with YPD medium, OP medium, and 50%YPD + 50%OP medium, and enhanced the lipid titer by 77.8%, 13.6%, and 63.0%, respectively. The microbial lipids obtained from both one-stage and two-stage fermentation showed no significant difference in fatty acid compositions, which were mainly dominated by palmitic acid (33.36–38.43%) and oleic acid (46.6–48.12%). Hence, a mixture of commercial medium and lignocellulosic biomass hydrolysate could be a promising option to balance the operating cost and lipid production.

scholarly journals Comparison of the Properties of Activated Carbons Produced in One-Stage and Two-Stage Processes

2018 ◽  
Vol 4 (3) ◽  
pp. 41 ◽  
Author(s):  
Davide Bergna ◽  
Toni Varila ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Carbon Content ◽  
Activated Carbons ◽  
Total Carbon ◽  
Activation Process ◽  
Two Stage ◽  
One Stage ◽  
Surface Areas ◽  
Significant Difference ◽  
Stage Process ◽  
The One

Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later activating the bio-chars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in one-stage and two-stage processes are considered. Activated carbons were produced by physical activation of two types of starting materials: bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes, and pore size distributions. The un-activated bio chars had varying surface areas, 190 and 140 m2 g−1 for birch and spruce, respectively, and pore volumes of 0.092 and 0.067 cm3 g−1, respectively. On the other hand, 530–617 and 647–679 m2 g−1 for activated bio chars from birch and spruce, respectively, and pore volumes 0.366–0.509 and 0.545–0.555 cm3 g−1, respectively, were obtained. According to the results obtained, two slightly different types of activated carbons are produced depending on whether a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas (SSA), according to the BET-model (Brunauer–Emmett–Teller), compared to the ones produced in a two-stage process (761–940 m2 g−1 vs. 540–650 m2 g−1, respectively). In addition, total pore volumes were higher in ACs from the one-stage process, but development of micro-pores was greater compared to those of the two-stage process. This indicates that the process can have an influence on the ACs’ porosity. There was no significant difference in total carbon content in general between the one-stage and two-stage processes for spruce and birch samples, but some differences were seen between the starting materials. Especially in the one-stage procedure with 2 and 4 h steam activation, there was nearly a 10% difference in carbon content between the spruce and birch samples.

scholarly journals Comparison of the Properties of Activated Carbons Produced in a One-stage And a Two-Stage Process

2018 ◽  
Author(s):  
Davide Bergna ◽  
Toni Varila ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Activated Carbons ◽  
Total Carbon ◽  
Physical Activation ◽  
Activation Process ◽  
Two Stage ◽  
Total Carbon Content ◽  
One Stage ◽  
Pore Size Distributions ◽  
Significant Difference ◽  
Stage Process

Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or first by carbonizing the biomass and later on activating the biochars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in a one-stage and a two-stage process are considered. Activated carbons were produced by physical activation of two types of starting materials, biochars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes and pore size distributions. The unactivated biochars had some degree of surface area and some porosity. According to the results obtained, two slightly different types of activated carbons are produced depending if a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas compared to the ones produced in a two-stage process. In addition, total pore volumes were higher in one-stage process but development of micropores is greater compared to two-stage process. There was no significant difference in total carbon content between one-stage and two-stage process.

scholarly journals Comparison of the Properties of Activated Carbons Produced in a One-Stage and a Two-Stage Process

2018 ◽  
Author(s):  
Davide Bergna ◽  
Toni Varila ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Activated Carbons ◽  
Total Carbon ◽  
Physical Activation ◽  
Activation Process ◽  
Two Stage ◽  
Total Carbon Content ◽  
One Stage ◽  
Pore Size Distributions ◽  
Significant Difference ◽  
Stage Process

Activated carbons can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later on activating the biochars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in a one-stage and a two-stage process are considered. Activated carbons were produced by physical activation of two types of starting materials, bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes and pore size distributions. The un-activated bio chars had some degree of surface area 190 and 140 m2g-1 for spruce and birch and pore volumes of 0.067 and 0.092 cm3g-1. According to the results obtained, two slightly different types of activated carbons are produced depending if a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas compared to the ones produced in a two-stage process (761-940 m2g-1 vs. 540-650 m2g-1) . In addition, total pore volumes were higher in one-stage process but development of micropores is greater compared to two-stage process. There was no significant difference in total carbon content between one-stage and two-stage process.

Repair of Asymmetric Bilateral Cleft lip: 1 Stage or 2 Stage

2021 ◽  
pp. 105566562110139
Author(s):  
Xinran Zhao ◽  
Yilai Wu ◽  
Guomin Wang ◽  
Yusheng Yang ◽  
Ming Cai
Keyword(s):  
Cleft Lip ◽  
Outcome Measure ◽  
Scar Tissue ◽  
Anatomical Reduction ◽  
Scoring Method ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference ◽  
Bilateral Cleft Lip ◽  
Surgery Outcomes

Objective: To verify the advantages and indications of 1-stage and 2-stage repair for asymmetric bilateral cleft lip (BCL). Design: Retrospective study. Setting: From January 2004 to December 2016 in our department. Patients: Patients with BCL. Main Outcome Measure(s): Over 6 months after the operation, the surgery outcomes were evaluated and graded by 2 experienced surgeons. Results: The result of surgery was evaluated using the scoring method of Mortier et al and Anastassov and Chipkov. Among 133 patients with asymmetric BCL, 61 (45.9%) had 1-stage repair and 72 (54.1%) had 2-stage repair. Sixty-eight (51.1%) patients had complete-incomplete cleft lip (CL), and those who underwent 1-stage repair showed a trend of better outcome ( P = .028). Fifty (37.6%) patients with incomplete-microform CL showed no significant difference between the outcomes of 2 surgery plans ( P = .253). In 15 (11.3%) patients with complete-microform CL, only one had 1-stage repair with a score of 8.5. The other 14 patients with 2-stage repair were scored 3.68 ± 1.28. Two-stage repair was preferable when the deformity degree was very different on 2 sides, as it could reduce unnecessary scar tissue and extend the nasal columella. One-stage repair could help to achieve the anatomical reduction of the orbicularis oris and a better contour of the vermilion tubercle. Conclusion: One-stage repair is recommended for patients with complete-incomplete CL and incomplete-microform CL. Two-stage repair for patients with complete-microform CL is preferred in our center, but more studies are required to support this conclusion.

Surgical Management of Simultaneous Anterior Cruciate Ligament and Patellar Tendon Ruptures: A Systematic Review

2017 ◽  
Vol 31 (09) ◽  
pp. 875-883 ◽  
Author(s):  
Carlos Meheux ◽  
Robert Jack ◽  
Patrick McCulloch ◽  
David Lintner ◽  
Joshua Harris
Keyword(s):  
Systematic Review ◽  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Activity Level ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference ◽  
Anterior Cruciate ◽  
The One

AbstractThis study performs a systematic review to determine (1) if a significant difference exists in return to preinjury activity level between one- and two-stage treatment of combined anterior cruciate ligament (ACL) and patellar tendon (PT) tears; and (2) if a significant difference exists in the number of postoperative complications between the two differing surgical treatment approaches. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and registered on PROSPERO. MEDLINE, Cochrane Central Register of Controlled Trials, SCOPUS, and Sport Discus were searched for English language level I–IV evidence studies on either one- (simultaneous) or two-stage (sequential) surgical treatment of simultaneously sustained ipsilateral ACL and PT tears. The approach to initial evaluation, diagnosis, treatment, and outcomes were qualitatively analyzed. Methodological quality assessment of all included studies was completed using the Methodological Index for Non-randomized Studies (MINORS). The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess quality of evidence and provide strength of recommendation. Statistical analyses were done using Fischer's exact test. Eleven articles (18 patients; 83% males; mean age, 31.1 ± 10.1 years; mean follow-up, 2.2 ± 1.7 years; and mean MINORS 7.8/16) were analyzed. Eight patients had a one-stage procedure (primary PT repair and ACL reconstruction), and 10 patients underwent a two-stage procedure (primary PT repair first followed by ACL reconstruction) with mean 28 ± 45.7 weeks (5 weeks–3 years) between surgeries. The rate for return to preinjury activity level after surgery was not significantly different between one- (88%) and two-stage (100%) (p = 0.444). There was a significantly higher complication rate (p = 0.023) in the one-stage (stiffness, instability, and patella baja) versus two-stage surgery (no complications). There was no significant difference in return to preinjury activity level between one- and two-stage PT repair and ACL reconstruction. However, the one-stage combined surgery had a significantly higher complication rate compared with two-stage surgery. The level of evidence is IV.

In Vivo Recovery of Factor VIII: A Comparison of One-Stage and Two-Stage Assay Methods

1979 ◽  
Vol 42 (04) ◽  
pp. 1230-1239 ◽  
Author(s):  
I M Nilsson ◽  
T B L Kirkwood ◽  
T W Barrowcliffe
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
In Vitro Assays ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference ◽  
Assay Methods ◽  
The One ◽  
Fraction I

SummaryThe recovery and half-life of VIII: C in the plasma of severely haemophilic patients was measured by one-stage and two-stage assays after injection of two Factor VIII concentrates (Hemofil, Hyland and Fraction I-O, Kabi). Plasma volumes were measured with an Evans� Blue technique, and both concentrates and post-infusion samples were measured against the same plasma standard.There was a highly significant difference in recoveries estimated by the two assay methods. The one-stage assays gave the most consistent results, in that the average recovery was 100%, whereas the two-stage assays gave only about 80% of the value expected from in vitro assays. There was no difference in recoveries between the two concentrates.The two-stage assays gave a slightly shorter half-life than the one-stage assays, and the half-life of Hemofil was also shorter than that of Fraction I-O.

scholarly journals Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Ladan Jamshidy ◽  
Hamid Reza Mozaffari ◽  
Payam Faraji ◽  
Roohollah Sharifi
Keyword(s):  
Standard Method ◽  
Mean Value ◽  
Marginal Gap ◽  
Two Stage ◽  
Finish Line ◽  
One Stage ◽  
Impression Technique ◽  
Significant Difference ◽  
The Mean ◽  
The One

Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

Speech and Hearing Outcomes of the Patients with Cleft Lip and Palate: Comparison between One-Stage Simultaneous and Two-Stage Surgical Repairs

2020 ◽  
Vol 103 (11) ◽  
pp. 1171-1177
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Common Belief ◽  
Two Stage ◽  
Treatment Protocols ◽  
Palatal Fistula ◽  
One Stage ◽  
Significant Difference ◽  
Cleft Lip Palate ◽  
Palate Repair

Background: Conventional treatment for cleft lip and palate patients is lip repair at three to four months and then palatal repair at nine to 12 months of age. However, for the patients who delay seeing a doctor especially in a developing area such as Northern Thailand, simultaneous lip and palate repair is performed at 12 to 18 months of age or later, depending on the age at the first visit. It is a common belief that patients with cleft lip and palate will be behind non-cleft patients in early development phonemes because of the open palate. This delay persists until the palate is repaired and on into the postoperative period. This proposition has not been proven with long-term clinical outcomes in one-stage repairs. Objective: To investigate the effects of one-stage repair on speech assessment, hearing, and incidence of palatal fistula. The results were compared with conventional two-stage surgical repairs. Materials and Methods: The present study was designed two groups. Group 1 consisted of 25 children (mean age 11.28±1.93 years) treated with a one-stage repair. Cleft lip, palate, and alveolus were repaired at a single surgical session in the first 18 months of life (mean age at the time of surgery 13.52±4.51 months). Group 2 consisted of 17 children (mean age 11.02±2.23 years) treated in two-stage surgical repairs. Lip repair was performed at a median age of 4.01 months (IQR 3.62 to 5.46), and palate repair was performed at a mean age of 13.54±4.14 months. Both groups underwent cleft lip and palate repairs at the Division of Plastic Surgery, Department of Surgery, Faculty of Medicine, Chiang Mai University between January 1, 2004 and December 31, 2010. Speech and hearing for all patients were evaluated by experienced ENT doctors. The palatal fistula was evaluated by the same plastic surgeons. Results: One-stage repair showed significant normal articulation and less articulation disorder when compared with two-stage surgical repairs. However, no significant difference was determined for other speech assessments, hearing, and incidence of palatal fistula. Conclusion: Because one-stage repair seems to have a more positive influence on articulation, and both surgical treatment protocols give similar results on speech assessments, hearing, and incidence of palatal fistula, regardless of the timing of the surgery, the one-stage repair is not inferior to conventional two-stage surgical repairs for patients in developing areas. This is due to several important advantages, such as less hospitalization, lower cost, and less chance of nosocomial infection. Keywords: One-stage repair, Speech, Hearing, Palatal fistula, Cleft lip, Palate

scholarly journals Clinical and radiographics results at 3 years of RCT with split-mouth design of submerged vs. nonsubmerged single laser-microgrooved implants in posterior areas

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Renzo Guarnieri ◽  
Dario Di Nardo ◽  
Gianni Di Giorgio ◽  
Gabriele Miccoli ◽  
Luca Testarelli
Keyword(s):  
Soft Tissue ◽  
Statistical Difference ◽  
Soft Tissues ◽  
Gingival Recession ◽  
Statistical Correlation ◽  
Two Stage ◽  
One Stage ◽  
Keratinized Tissue ◽  
Significant Difference

Abstract Aim To evaluate and compare radiographic crestal bone loss (CBL) and soft tissue parameters around submerged/two-stage and nonsubmerged/one-stage single implants with the same endosseous portion (body design and surface, thread design and distance) and identical intramucosal laser-microgrooved surface, after 3 years of loading. Materials and methods Twenty submerged/two-stage implants and 20 nonsubmerged/one-stage implants were placed randomly with a split-mouth design in the posterior areas of 20 partially edentulous patients. Radiographic and clinical examinations were carried out at the implant placement, at the delivery of prosthetic restorations, and at each year of the follow-up period. Plaque index (PI), probing depth (PD), bleeding on probing (BOP), and gingival recession (REC) were recorded. Radiographic crestal bone levels were assessed at the mesial and distal aspect of the implant sites. In addition, the influence of the vertical keratinized tissue thickness (KTT) on CBL was investigated. Results At the delivery of prosthetic restorations, a statistically significant difference (P = 0.013) was found in radiographic mean CBL between submerged and nonsubmerged implants (0.15 ± 0.05 mm vs. 0.11 ± 0.04 mm). At the end of the follow-up period, no statistical difference (P = 0.741) was found in the mean CBL between submerged and nonsubmerged implants (0.27 ± 04 mm vs. 0.26 ± 0.5 mm). The changes in the soft tissues including PI, PD, BOP, and REC had no significant differences in either group. Moreover, KTT did not show a statistical correlation with CBL. Conclusions After 3 years of loading, no statistical difference was noted in CBL and soft tissue conditions between single submerged two-stage and nonsubmerged one-stage laser-microgrooved implants. Trial registration http://clinicaltrials.gov/ct2/show/NCT03674762

scholarly journals 886. Impact of Type of Surgical Management on the Incidence of Recurrent Surgical Site Infections Following Hip and Knee replacements in Calgary, Alberta

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S478-S478
Author(s):  
Swati Chavda ◽  
Jenine Leal ◽  
Shannon Puloski ◽  
Elissa Rennert May
Keyword(s):  
Surgical Management ◽  
Early Recognition ◽  
Small Sample Size ◽  
Revision Arthroplasty ◽  
Surgical Site Infections ◽  
Small Sample ◽  
Recurrence Rates ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference

Abstract Background Recurrent surgical site infections (SSIs) are associated with decreased quality of life for patients and increased economic burden to healthcare systems. Positive cultures at reimplantation and patient co-morbidities have been shown to increase the risk of recurrent SSI in hip and knee surgical site infections. Two-stage exchange has been considered for the most appropriate surgical management for these SSI’s, however, it is unclear whether the type of revision arthroplasty and pathogen of the first SSI impacts recurrence rates. Methods A retrospective review of prospectively collected data on all complex SSIs following primary hip and knee arthroplasties between April 1 2012 and March 31, 2019, in Calgary, Alberta was performed. Patients were followed for two years post-index arthroplasty to determine initial management of first complex SSI (Debridement, antibiotics and implant retention (DAIR) vs DAIR+liner exchange vs one-stage vs two-stage), rate of recurrent complex SSI, and microbiological data for first and subsequent SSI’s. Results Of the 142 complex SSIs, 95 (66.9%) were managed with DAIR and liner exchange, 25 (17.6%) were managed with DAIR, 13 (9.1%) with one-stage and 8 (5.6%) with two-stage procedures. The recurrence rate was 19/95 (20%) for DAIR and liner, 8/25 (32%) for DAIR alone, 2/13 (15%) with one stage, and 3/8 (37.5%) with two-stage. There was no significant difference in recurrence rates of complex SSI when stratified by surgical management. Of the pathogens, Staphylococcus aureus (S.aureus) (including methicillin-resistant S. aureus (MRSA)) accounted for 35.2% of total first SSI and 50% of recurrences. A significantly higher proportion of S.aureus infections (including MRSA) ended up with a recurrent infection compared to all other pathogens (p=0.045). Of the 32 recurrences, 28.1% were due to the same pathogen as the initial SSI. Conclusion S.aureus was the most common pathogen causing initial and recurrent SSIs. This reinforces that S.aureus complex SSIs would likely benefit from early recognition and aggressive treatment. Recurrence of SSI was not impacted by type of revision arthroplasty. This study is limited by a small sample size. These findings contribute to the paucity of literature in this area and suggest a need for expansion to larger populations. Disclosures All Authors: No reported disclosures

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