615 research outputs found
Modeling drying kinetics of thyme (thymus vulgaris l.): theoretical and empirical models, and neural networks
[EN] The drying kinetics of thyme was analyzed by considering different conditions: air temperature of between
40 C and 70 C, and air velocity of 1 m/s. A theoretical diffusion model and eight different empirical models
were fitted to the experimental data. From the theoretical model application, the effective diffusivity per unit
area of the thyme was estimated (between 3.68 10 5 and 2.12 10 4 s 1). The temperature dependence
of the effective diffusivity was described by the Arrhenius relationship with activation energy of 49.42 kJ/mol.
Eight different empirical models were fitted to the experimental data. Additionally, the dependence of the
parameters of each model on the drying temperature was determined, obtaining equations that allow estimating
the evolution of the moisture content at any temperature in the established range. Furthermore,
artificial neural networks were developed and compared with the theoretical and empirical models using
the percentage of the relative errors and the explained variance. The artificial neural networks were found
to be more accurate predictors of moisture evolution with VAR 99.3% and ER 8.7%.The authors acknowledge the financial support from the 'Ministerio de Educacion y Ciencia' in Spain, CONSOLIDER INGENIO 2010 (CSD2007-00016).Rodríguez Cortina, J.; Clemente Polo, G.; Sanjuán Pellicer, MN.; Bon Corbín, J. (2014). Modeling drying kinetics of thyme (thymus vulgaris l.): theoretical and empirical models, and neural networks. Food Science and Technology International. 20(1):13-22. https://doi.org/10.1177/1082013212469614S132220
Thermal inactivation and conformational lock studies on glucose oxidase
In this study, the dissociative thermal inactivation
and conformational lock theories are applied for the
homodimeric enzyme glucose oxidase (GOD) in order to
analyze its structure. For this purpose, the rate of activity
reduction of glucose oxidase is studied at various temperatures
using b-D-glucose as the substrate by incubation of
enzyme at various temperatures in the wide range between
40 and 70 �C using UV–Vis spectrophotometry. It was
observed that in the two ranges of temperatures, the
enzyme has two different forms. In relatively low temperatures,
the enzyme is in its dimeric state and has normal
activity. In high temperatures, the activity almost disappears
and it aggregates. The above achievements are confirmed
by dynamic light scattering. The experimental
parameter ‘‘n’’ as the obvious number of conformational
locks at the dimer interface of glucose oxidase is obtained
by kinetic data, and the value is near to two. To confirm the
above results, the X-ray crystallography structure of the
enzyme, GOD (pdb, 1gal), was also studied. The secondary
and tertiary structures of the enzyme to track the thermal
inactivation were studied by circular dichroism and
fluorescence spectroscopy, respectively. We proposed a
mechanism model for thermal inactivation of GOD based
on the absence of the monomeric form of the enzyme by
circular dichroism and fluorescence spectroscopy
Sensory Measurements: Coordination and Standardization
Do sensory measurements deserve the label of “measurement”? We argue that they do. They fit with an epistemological view of measurement held in current philosophy of science, and they face the same kinds of epistemological challenges as physical measurements do: the problem of coordination and the problem of standardization. These problems are addressed through the process of “epistemic iteration,” for all measurements. We also argue for distinguishing the problem of standardization from the problem of coordination. To exemplify our claims, we draw on olfactory performance tests, especially studies linking olfactory decline to neurodegenerative disorders
Histoplasmosis infection in patients with rheumatoid arthritis, 1998-2009
<p>Abstract</p> <p>Background</p> <p>Patients with rheumatic diseases including rheumatoid arthritis (RA) are at increased risk for infections related to both the disease and its treatments. These include uncommonly reported infections due to histoplasmosis.</p> <p>Methods</p> <p>Medical record review of all patients with a diagnosis of RA who developed new histoplasmosis infection in an endemic region between Jan 1, 1998 and Jan 30, 2009 and who were seen at Mayo Clinic in Rochester, Minnesota was performed.</p> <p>Results</p> <p>Histoplasmosis was diagnosed in 26 patients. Most patients were on combination therapies; 15 were on anti-tumor necrosis factor (anti-TNF) agents, 15 on corticosteroids and 16 on methotrexate. Most received more than 6 months of itraconazole and/or amphotericin treatment. Two patients died of causes unrelated to histoplasmosis. Anti-TNF treatment was restarted in 4/15 patients, with recurrence of histoplasmosis in one.</p> <p>Conclusions</p> <p>In this largest single center series of patients with RA and histoplasmosis in the era of immunomodulatory therapy, we found that most patients had longstanding disease and were on multiple immunomodulatory agents. Most cases were pulmonary; typical signs and symptoms of disease were frequently lacking.</p
Improving the delivery and efficiency of fungus-impregnated cloths for control of adult Aedes aegypti using a synthetic attractive lure
Abstract Background Entomopathogenic fungi are highly promising agents for controlling Aedes aegypti mosquitoes. Deploying fungus-impregnated black cloths in PET traps efficiently reduced Ae. aegypti female survival rates under intra-domicile conditions. With the aim of further increasing the effectiveness of the traps, the addition of attractive lures to fungus-impregnated traps was evaluated. Methods Black cloths were suspended inside 2 l plastic bottles called “PET traps”. These traps were placed in rooms simulating human residences. The first experiments evaluated the attraction of mosquitoes to PET traps with black cloths covered in adhesive film with and without synthetic lures (AtrAedes™). Traps were left in the test rooms for either 24 or 48 h. The attractiveness of the lures over time was also evaluated. The efficiency of PET traps with fungus-impregnated black cloths associated with lures was compared to that of traps without lures. Results The highest percentage of captured mosquitoes (31 and 66%) were observed in PET traps with black cloths covered in adhesive film + attractive lure maintained in test rooms for 24 h and 48 h, respectively. Black cloths covered in adhesive film captured 17 or 36% of the mosquitoes at 24 h and 48 h, respectively. The attractiveness of the lures fell gradually over time, capturing 37% after 5 days on the bench and 22% of the mosquitoes after 30 days exposure to ambient conditions. Associating attractive synthetic lures with black cloths impregnated with M. anisopliae placed in test rooms for 120 h reduced mean survival to 32%, whilst black cloths impregnated with M. anisopliae without lures resulted in a 48% survival rate. Using Beauveria bassiana in the traps resulted in a 52% reduction in mosquito survival, whilst combining Beauveria and AtrAedes resulted in a 36% survival rate. PET traps impregnated with fungus + AtrAedes resulted in similar reductions in survival when left in the rooms for 24, 48, 72 or 120 h. Conclusions AtrAedes increased attractiveness of PET traps with black cloths under intra-domicile conditions and when associated with M. anisopliae or B. bassiana, significantly reduced Aedes survival. This strategy will reduce the number of PET traps necessary per household
The effects of thermal capsulorrhaphy of medial parapatellar capsule on patellar lateral displacement
<p>Abstract</p> <p>Background</p> <p>The effectiveness of thermal shrinkage on the medial parapatellar capsule for treating recurrent patellar dislocation is controversial. One of reasons why it is still controversial is that the effectiveness is still qualitatively measured. The purpose of this study was to quantitatively determine the immediate effectiveness of the medial parapatellar capsule shrinkage as in clinical setting.</p> <p>Methods</p> <p>Nine cadaveric knees were used to collect lateral displacement data before and after medial shrinkage or open surgery. The force and displacement were recorded while a physician pressed the patella from the medial side to mimic the physical exam used in clinic. Ten healthy subjects were used to test the feasibility of the technique on patients and establish normal range of lateral displacement of the patella under a medial force. The force applied, the resulting displacement and the ratio of force over displacement were compared among four data groups (normal knees, cadaveric knees before medial shrinkage, after shrinkage and after open surgery).</p> <p>Results</p> <p>Displacements of the cadaveric knees both before and after thermal modification were similar to normal subjects, and the applied forces were significantly higher. No significant differences were found between before and after thermal modification groups. After open surgery, displacements were reduced significantly while applied forces were significantly higher.</p> <p>Conclusion</p> <p>No immediate difference was found after thermal shrinkage of the medial parapatellar capsule. Open surgery immediately improved of the lateral stiffness of the knee capsule.</p
Information and Discriminability as Measures of Reliability of Sensory Coding
Response variability is a fundamental issue in neural coding because it limits all information processing. The reliability of neuronal coding is quantified by various approaches in different studies. In most cases it is largely unclear to what extent the conclusions depend on the applied reliability measure, making a comparison across studies almost impossible. We demonstrate that different reliability measures can lead to very different conclusions even if applied to the same set of data: in particular, we applied information theoretical measures (Shannon information capacity and Kullback-Leibler divergence) as well as a discrimination measure derived from signal-detection theory to the responses of blowfly photoreceptors which represent a well established model system for sensory information processing. We stimulated the photoreceptors with white noise modulated light intensity fluctuations of different contrasts. Surprisingly, the signal-detection approach leads to a safe discrimination of the photoreceptor response even when the response signal-to-noise ratio (SNR) is well below unity whereas Shannon information capacity and also Kullback-Leibler divergence indicate a very low performance. Applying different measures, can, therefore, lead to very different interpretations concerning the system's coding performance. As a consequence of the lower sensitivity compared to the signal-detection approach, the information theoretical measures overestimate internal noise sources and underestimate the importance of photon shot noise. We stress that none of the used measures and, most likely no other measure alone, allows for an unbiased estimation of a neuron's coding properties. Therefore the applied measure needs to be selected with respect to the scientific question and the analyzed neuron's functional context
Health status of adults with Short Stature: A comparison with the normal population and one well-known chronic disease (Rheumatoid Arthritis)
BACKGROUND: To examine the subjective health status of adults with short stature (ShSt) and compare with the general population (GP) and one well-known chronic disease, rheumatoid artritis (RA). In addition, to explore the association between age, gender, height, educational level and different aspects of health status of adults with short stature. METHODS: A questionnaire was mailed to 72 subjects with short stature registered in the database of a Norwegian resource centre for rare disorders, response rate 61% (n = 44, age 16–61). Health status was assessed with SF-36 version 2. Comparison was done with age and gender matched samples from the general population in Norway (n = 264) and from subjects with RA (n = 88). RESULTS: The ShSt sample reported statistically significant impaired health status in all SF-36 subscales compared with the GP sample, most in the physical functioning, Mean Difference (MD) 34 (95% Confidence Interval (CI) 25–44). The ShSt reported poorer health status in mental health, MD 11 (95% CI 4–18) and social functioning, MD 11 (95% CI 2–20) but better in role physical MD 13 (95% CI 1–25) than the RA sample. On the other subscales there were minor difference between the ShSt and the RA sample. Within the short stature group there was a significant association between age and all SF-36 physical subcales, height was significantly associated with physical functioning while level of education was significantly associated with mental health. CONCLUSION: People with short stature reported impaired health status in all SF-36 subscales indicating that they have health problems that influence their daily living. Health status seems to decline with increasing age, and earlier than in the general population
The unfolded protein response and its relevance to connective tissue diseases
The unfolded protein response (UPR) has evolved to counter the stresses that occur in the endoplasmic reticulum (ER) as a result of misfolded proteins. This sophisticated quality control system attempts to restore homeostasis through the action of a number of different pathways that are coordinated in the first instance by the ER stress-senor proteins IRE1, ATF6 and PERK. However, prolonged ER-stress-related UPR can have detrimental effects on cell function and, in the longer term, may induce apoptosis. Connective tissue cells such as fibroblasts, osteoblasts and chondrocytes synthesise and secrete large quantities of proteins and mutations in many of these gene products give rise to heritable disorders of connective tissues. Until recently, these mutant gene products were thought to exert their effect through the assembly of a defective extracellular matrix that ultimately disrupted tissue structure and function. However, it is now becoming clear that ER stress and UPR, because of the expression of a mutant gene product, is not only a feature of, but may be a key mediator in the initiation and progression of a whole range of different connective tissue diseases. This review focuses on ER stress and the UPR that characterises an increasing number of connective tissue diseases and highlights novel therapeutic opportunities that may arise
The DNA Repair Gene APE1 T1349G Polymorphism and Risk of Gastric Cancer in a Chinese Population
Background: Apurinic/apyrimidinic endonuclease 1 (APE1) has a central role in the repair of apurinic apyrimidic sites through both its endonuclease and its phosphodiesterase activities. A common APE1 polymorphism, T1349G (rs3136820), was previously shown to be associated with the risk of cancers. Objective: We hypothesized that the APE1 T1349G polymorphism is also associated with risk of gastric cancer. Methods: In a hospital-based case-control study of 338 case patients with newly diagnosed gastric cancer and 362 cancerfree controls frequency-matched by age and sex, we genotyped the T1349G polymorphism and assessed its associations with risk of gastric cancer. Results: Compared with the APE1 TT genotype, individuals with the variant TG/GG genotypes had a significantly increased risk of gastric cancer (odds ratio = 1.69, 95 % confidence interval = 1.19–2.40), which was more pronounced among subgroups of aged #60 years, male, ever smokers, and ever drinkers. Further analyses revealed that the variant genotypes were associated with an increased risk for diffuse-type, low depth of tumor infiltration (T1 and T2), and lymph node metastasis gastric cancer. Conclusions: The APE1 T1349G polymorphism may be a marker for the development of gastric cancer in the Chinese population. Larger studies are required to validate these findings in diverse populations
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