212 research outputs found
Kinetic Parameters Determination Of Glucoamylase On Hydrolysis Reaction Of Sagoo Starch (Metroxylon sp)
Sagoo plant (Metroxylon sp.) numerous in eastern Indonesia, such as Maluku and Papua. Sagoo starch containing amylose and amylopectin. Sagoo starch hydrolysis can be carried out by enzymes, such as glucoamylase or often called amiloglukosidase or α-1 ,4-glukanoglukohidrolase, an extracellular enzyme capable hydrolyzes α-1, 4 on amylose and α-1, 6 in amylopectin. The enzymatic hydrolysis of starch can be reviewed in the kinetics of the Michaelis-Menten equation and Lineweaver-Burk equation. The aims of this study to determine the kinetic parameters (Vmax and Km) of glucoamylase on hydrolysis of sagoo starch. Glucoamylase has an optimum temperature of 50 oC and pH optimum 6.5. At optimum conditions, based on Michaelis-Menten equation, the value of Vmax is 1.09 U / mL / min and Km value is 0.82. Based on Lineweaver-Burk equation, the value of Vmax was 1.03 U / mL / min and Km value was 0.84%
Kinetic Parameters Determination Of Glucoamylase On Hydrolysis Reaction Of Sagoo Starch (Metroxylon sp)
Sagoo plant (Metroxylon sp.) numerous in eastern Indonesia, such as Maluku and Papua. Sagoo starch containing amylose and amylopectin. Sagoo starch hydrolysis can be carried out by enzymes, such as glucoamylase or often called amiloglukosidase or α-1 ,4-glukanoglukohidrolase, an extracellular enzyme capable hydrolyzes α-1, 4 on amylose and α-1, 6 in amylopectin. The enzymatic hydrolysis of starch can be reviewed in the kinetics of the Michaelis-Menten equation and Lineweaver-Burk equation. The aims of this study to determine the kinetic parameters (Vmax and Km) of glucoamylase on hydrolysis of sagoo starch. Glucoamylase has an optimum temperature of 50 oC and pH optimum 6.5. At optimum conditions, based on Michaelis-Menten equation, the value of Vmax is 1.09 U / mL / min and Km value is 0.82. Based on Lineweaver-Burk equation, the value of Vmax was 1.03 U / mL / min and Km value was 0.84%
Kinetic Parameters Determination Of Glucoamylase On Hydrolysis Reaction Of Sagoo Starch (Metroxylon sp)
Sagoo plant (Metroxylon sp.) numerous in eastern Indonesia, such as Maluku and Papua. Sagoo starch containing amylose and amylopectin. Sagoo starch hydrolysis can be carried out by enzymes, such as glucoamylase or often called amiloglukosidase or α-1 ,4-glukanoglukohidrolase, an extracellular enzyme capable hydrolyzes α-1, 4 on amylose and α-1, 6 in amylopectin. The enzymatic hydrolysis of starch can be reviewed in the kinetics of the Michaelis-Menten equation and Lineweaver-Burk equation. The aims of this study to determine the kinetic parameters (Vmax and Km) of glucoamylase on hydrolysis of sagoo starch. Glucoamylase has an optimum temperature of 50 oC and pH optimum 6.5. At optimum conditions, based on Michaelis-Menten equation, the value of Vmax is 1.09 U / mL / min and Km value is 0.82. Based on Lineweaver-Burk equation, the value of Vmax was 1.03 U / mL / min and Km value was 0.84%
Kinetic Parameters Determination Of Glucoamylase On Hydrolysis Reaction Of Sagoo Starch (Metroxylon sp)
Sagoo plant (Metroxylon sp.) numerous in eastern Indonesia, such as Maluku and Papua. Sagoo starch containing amylose and amylopectin. Sagoo starch hydrolysis can be carried out by enzymes, such as glucoamylase or often called amiloglukosidase or α-1 ,4-glukanoglukohidrolase, an extracellular enzyme capable hydrolyzes α-1, 4 on amylose and α-1, 6 in amylopectin. The enzymatic hydrolysis of starch can be reviewed in the kinetics of the Michaelis-Menten equation and Lineweaver-Burk equation. The aims of this study to determine the kinetic parameters (Vmax and Km) of glucoamylase on hydrolysis of sagoo starch. Glucoamylase has an optimum temperature of 50 oC and pH optimum 6.5. At optimum conditions, based on Michaelis-Menten equation, the value of Vmax is 1.09 U / mL / min and Km value is 0.82. Based on Lineweaver-Burk equation, the value of Vmax was 1.03 U / mL / min and Km value was 0.84%
Real-Gas Effects and Phase Separation in Underexpanded Jets at Engine-Relevant Conditions
A numerical framework implemented in the open-source tool OpenFOAM is
presented in this work combining a hybrid, pressure-based solver with a
vapor-liquid equilibrium model based on the cubic equation of state. This
framework is used in the present work to investigate underexpanded jets at
engine-relevant conditions where real-gas effects and mixture induced phase
separation are probable to occur. A thorough validation and discussion of the
applied vapor-liquid equilibrium model is conducted by means of general
thermodynamic relations and measurement data available in the literature.
Engine-relevant simulation cases for two different fuels were defined. Analyses
of the flow field show that the used fuel has a first order effect on the
occurrence of phase separation. In the case of phase separation two different
effects could be revealed causing the single-phase instability, namely the
strong expansion and the mixing of the fuel with the chamber gas. A comparison
of single-phase and two-phase jets disclosed that the phase separation leads to
a completely different penetration depth in contrast to single-phase injection
and therefore commonly used analytical approaches fail to predict the
penetration depth.Comment: Preprint submitted to AIAA Scitech 2018, Kissimmee, Florid
Corneal collagen cross-linking as treatment for infectious and non-infectious corneal melting in cats and dogs: results of a prospective, non-randomized, controlled trial
OBJECTIVE. UV-A/Riboflavin crosslinking of corneal collagen fibers (CXL) is a highly promising therapy for corneal melting in humans. A prospective interventional, non-randomized, controlled study was conducted to compare the stabilizing effect of CXL treatment on melting keratitis in dogs and cats and the complication rate of CXL to those of standardized intensive medical treatment.
PROCEDURES. Forty-nine eyes with melting keratitis were included in the study between October 2009 and October 2012. All eyes were treated according to the same medical treatment protocol. Nineteen eyes were CXL-treated and 30 eyes were not. Follow-up included slit-lamp examination, fluorescein staining, ulcer size measurement, stromal stability evaluation, photographic documentation and documentation of complications.
RESULTS. Five of 19 eyes in the CXL group and 9/30 eyes in the control group required rescue stabilization due to continued melting. Seven of the 9 control group corneas stabilized after rescue CXL treatment. At initial presentation, the ulcers in the canine CXL group were significantly deeper and larger than in the control group. Ulcer deepening during follow-up was more pronounced in the canine control group than in the canine CXL group. CXL treatment related complications were not observed.
CONCLUSIONS. Based on the similar failure rates in the control and CXL treatment groups despite the poorer initial situation in the CXL group, the tendency for the ulcers in the control group to deepen and the stabilization of all corneas receiving CXL rescue treatment, we believe that CXL has its place as an adjunctive therapy for melting keratitis in veterinary ophthalmology
Primary right atrium angiosarcoma mimicking pericarditis
<p>Abstract</p> <p>Background</p> <p>Primary cardiac neoplasms occur rarely and most of them are benign. Malignant tumors including angiosarcoma are extremely rare and have a non specific clinical presentation and a poor prognosis.</p> <p>Case presentation</p> <p>We present a case of a young male who was transferred to our hospital because of shock and multiple organ failure after a complicated pericardial biopsy. During the previous seven months he presented with recurrent episodes of pericardial effusions and tamponade. Chest computed tomography revealed a mass in the right atrium, infiltrating the myocardium and pericardium. During emergency surgery that followed, the patient died because of uncontrolled hemorrhage. Autopsy revealed the mass of the right atrium, which was identified on histological examination as primary cardiac angiosarcoma.</p> <p>Conclusion</p> <p>This case highlights the difficulties both in early diagnosis and in the management of patients with cardiac angiosarcoma.</p
Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine
In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown
Unravelling enzymatic discoloration in potato through a combined approach of candidate genes, QTL, and expression analysis
Enzymatic discoloration (ED) of potato tubers was investigated in an attempt to unravel the underlying genetic factors. Both enzyme and substrate concentration have been reported to influence the degree of discoloration and as such this trait can be regarded as polygenic. The diploid mapping population C × E, consisting of 249 individuals, was assayed for the degree of ED and levels of chlorogenic acid and tyrosine. Using this data, Quantitative Trait Locus (QTL) analysis was performed. Three QTLs for ED have been found on parental chromosomes C3, C8, E1, and E8. For chlorogenic acid a QTL has been identified on C2 and for tyrosine levels, a QTL has been detected on C8. None of the QTLs overlap, indicating the absence of genetic correlations between these components underlying ED, in contrast to earlier reports in literature. An obvious candidate gene for the QTL for ED on Chromosome 8 is polyphenol oxidase (PPO), which was previously mapped on chromosome 8. With gene-specific primers for PPO gene POT32 a CAPS marker was developed. Three different alleles (POT32-1, -2, and -3) could be discriminated. The segregating POT32 alleles were used to map the POT32 CAPS marker and QTL analysis was redone, showing that POT32 coincides with the QTL peak. A clear correlation between allele combinations and degree of discoloration was observed. In addition, analysis of POT32 gene expression in a subset of genotypes indicated a correlation between the level of gene expression and allele composition. On average, genotypes having two copies of allele 1 had both the highest degree of discoloration as well as the highest level of POT32 gene expression
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Multiphase phenomena in Diesel fuel injection systems
Fuel Injection Equipment (FIE) are an integral component of modern Internal Combustion Engines (ICE), since they play a crucial role in the fuel atomization process and in the formation of a fuel/air combustible mixture, consequently affecting efficiency and pollutant formation. Advancements and improvements of FIE systems are determined by the complexity of the physical mechanisms taking place; the spatial scales are in the order of millimetres, flow may become locally highly supersonic, leading to very small temporal scales of microseconds or less. The operation of these devices is highly unsteady, involving moving geometries such as needle valves. Additionally, extreme pressure changes imply that many assumptions of traditional fluid mechanics, such as incompressibility, are no longer valid. Furthermore, the description of the fuel properties becomes an issue, since fuel databases are scarce or limited to pure components, whereas actual fuels are commonly hydrocarbon mixtures. Last but not least, complicated phenomena such as phase change or transition from subcritical to transcritical/supercritical state of matter further pose complications in the understanding of the operation of these devices
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