SEARCH · PubMed Health

Results for “Process optimization”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources

PubMed2005

Apoptosis in endometria of dysfuntional uterine bleeding women.

The study of apoptosis in endometrium of women with irregular uterine bleeding and its predictive value in endometrial malignancy. Analyze apoptotic and mitotic indices and their relevance in irregular uterine bleeding. To determine the expression of Bcl-2 oncoprotein in endometrial glands from patients with irregular uterine bleeding. Department of pathology in a Government Hospital serving a varied socio-economic population in Chennai. Random samples of endometrial currettings from dysfunctional uterine bleeding (DUB) patient who underwent endometrial curettage as therapeutic and diagnostic procedure during the year 2000. Of 50 cases of endometrial samples from patients diagnosed as cases of DUB, the apoptotic and mitotic indexing was carried out and histological categorization revealed 13 cases as Anovulatory. 14 as simple hyperplasia, 5 as early secretory endometrium, 4 as mid secretory and 4 as late secretory endometrium and 7 as endometrium showing features of hormonal imbalance. Three cases were not included, due to sub-optimal processing. A good correlation of the Bcl-2 expression and the apoptotic cell morphology/indices, in the different categories of the endometria of DUB cases is observed. This preliminary study gives an insight to the existence of a correlative pattern of apoptosis in DUB cases. A prospective study on a larger number of cases may substantiate the hypothesis that the Apoptotic and Mitotic indices are useful screening methods with predictive values on development of endometrial carcinoma. It is observed that an increased apoptotic index correlating with high Bcl-2 expression, reflecting the actual cell burden. This prolonged cell survival resisting cell deletion is associated with irregular uterine bleeding endometria.

Apoptosis↗

PubMed2005

Applying real-time control to enhance the performance of nitrogen removal in CAST system.

A bench-scale reactor(72 L) red with domestic sewage, was operated more than 3 months with three operation modes: traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operation mode on the system performance and to develop a feasible control strategy. Results obtained from fixed-time control study indicate that the variations of the pH and oxidation-reduction potential(ORP) profiles can represent dynamic characteristics of system and the cycle sequences can be controlled and optimized by the control points on the pH and ORP profiles. A control strategy was, therefore, developed and applied to real-time control mode. Compared with traditional mode, the total nitrogen(TN) removal can be increased by approximately 16% in modified mode and a mean TN removal of 92% was achieved in real-time control mode. Moreover, approximately 12.5% aeration energy was saved in real-time control mode. The result of this study shows that the performance of nitrogen removal was enhanced in modified operation mode. Moreover, the real-time control made it possible to optimize process operation and save aeration energy.

Bioreactors↗

PubMed2005

The implications of electronic health record for personalized medicine.

The emerging concept of an electronic health record (EHR) targeted at a patient centric, cross-institutional and longitudinal information entity (possibly spanning the individuals lifetime) has great promise for personalized medicine. In fact, it is probably the only vehicle through which we may truly realize the personalization of medicine beyond population-based genetic profiles that are expected to become part of medication and treatment indications in the near future. The new EHR standards include mechanisms that integrate clinical data with genomic testing results obtained through applying research-type procedures, such as full DNA sequencing, to an individual patient. Although the most optimal process for the utilization of integrated clinical-genomic data in the EHR framework is still unclear, the new Health Level Seven (HL7) Clinical Genomics Draft Standard for Trial Use suggests using the 'encapsulate & bubble-up' approach, which includes two main phases: the encapsulation of raw genomic data and bubbling-up the most clinically significant portions of that data, while associating it with clinical phenotypes residing in the individual's EHR.

Computational Biology↗

PubMed2006

[Noise image segmentation based on generalized fuzzy Gibbs random field].

In order to segment the blurred image with large noise, the authors propose a new Bayesian image segmentation method based on generalized fuzzy Gibbs random field. Based on the generalized fuzzy set, the new method introduces generalized fuzzy membership into Gibbs potential function and the potential function is redefined to obtain the new segmentation model. The optimal processing is executed through iterative conditional modes (ICM). The experiment results showed that the new approach could effectively segment the degenerated images.

Algorithms↗

PubMed1990

[Thermoanalytic techniques for the study of pharmaceutical products].

During the past years, there have been frequent demonstrations that thermoanalytical methods have found wide-spread use in pharmacy. Analysts have developed these techniques in pharmaceutical field in the estimation of impurities, in quality control procedures, in preformulation studies, in the active principle identification, in accelerated stability and in production process optimization. Wide-spread use of thermal methods is devoted to the identification of solid state of drugs (polymorphism, solvate, inclusion compound,...) due to its possible implication on bioavailability or on the stability of a final dosage form. Some examples of thermoanalytical applications are reported.

Chemistry, Pharmaceutical↗

PubMed1989

Effects of extracellular matrix on cytoskeletal and myofibrillar organization in vitro.

The distribution and three-dimensional relationship of myofibrillar and cytoskeletal components during myofibrillogenesis were examined in preparations of neonatal rat cardiac myocytes processed in parallel for scanning electron microscopy (SEM), intermediate voltage transmission electron microscopy (IVEM) and immunofluorescence (IF). Of the various methods used for processing, optimal results were achieved by pre-extraction with Triton X-100 in an actin-stabilizing buffer. This procedure effectively removed the surface membrane, as viewed by SEM images, while preserving myofibrillar and cytoskeletal structure, as evidenced by IF for actin, alpha-actinin and vinculin. Cytoskeletons in SEM images consisted of a cortex of anastomosing filaments through which ran parallel filament bundles oriented in the long axis of the cell and attached along their length to the substrate by numerous fine filaments. In IVEM images, myofibrils were laterally connected at the level of the Z bands. Myocytes grown on different extracellular matrices showed different patterns and distributions of both striated myofibrils and focal adhesions, as determined by IF for alpha-actinin and vinculin, respectively. Cells on collagen I and III contained striated myofibrils which extended to the cell perimeters where focal adhesions were predominately located. Cells on laminin and fibronectin matrices exhibited myofibrils and focal adhesions more centrally located. In addition, cells on laminin contained circumferential arcs of filaments near the cell periphery.

Animals↗

PubMed1987

Optimal background estimation in EELS.

In quantitative electron energy loss spectrometry, it is desirable to estimate the background law below core edge energy in a way that provides the maximum signal-to-noise ratio. Assuming an inverse power background model and independently Poisson distributed measurements, it is shown how to achieve this goal by using a maximum likelihood (ML) estimation technique which provides unbiased and minimum mean square error estimates of all parameters of interest. An efficient and computationally stable implementation of this procedure is proposed. Standard logarithmic least squares estimations are then compared with the ML approach and the gain in performance due to optimal processing is quantified.

Electrons↗

PubMed1986

Microscale synthesis of nitrogen-13-labeled cisplatin.

A microscale synthesis of [13N]cisplatin (cis-dichlorodiammineplatinum(II), cis-DDP) from cyclotron-produced [13N]ammonia is presented. Temperature, reaction time, ratios, and concentration of reactants have been optimized for each step of the synthesis. Purification is performed by ion exchange chromatography. Radiochemical purity and optimization processes are controlled by high performance liquid chromatography and high performance thin layer chromatography--22 mCi [13N]cisplatin in 10 ml of solution is produced. The entire procedure takes approximately 15 min and the specific activity is approximately 300 mCi/mumole at EOB.

Ammonia↗

PubMed1983

Induction of antigen-specific antibody response in human peripheral blood lymphocytes in vitro by a dog kidney cell vaccine against rabies virus (DKCV).

In the present report an in vitro method for obtaining a secondary human antibody response to a dog kidney cell vaccine against rabies virus (DKCV) is described. Cultures of peripheral blood mononuclear cells from normal rabies-immune and nonimmune donors were stimulated in vitro by DKCV. The production of virus-specific antibody in supernatant fluids was monitored by ELISA. Antibody was produced by lymphocytes from rabies-immune individuals, whereas those of nonimmune subjects consistently failed to produce anti-rabies antibodies after in vitro stimulation with DKCV. The generation of the anti-rabies virus antibody response of lymphocytes stimulated with DKCV was shown to be an antigen-dependent, as well as an antigen-specific process. Optimal antigen-specific responses were observed at relatively low concentrations of antigen (10(-1) to 10(-2) micrograms/culture). At increasing concentrations of antigen in culture (greater than 1 microgram/culture), the anti-rabies virus response was suppressed. Antibody produced upon stimulation was capable of neutralizing rabies virus. The response to rabies virus requires T cell help because lymphocytes depleted of SE rosetting cells did not respond to an antigenic stimulus. Studies in which the same individuals were followed over time showed a sequential development of circulating B cell subsets. The system may provide a model for the study of human B cell differentiation in vivo and in vitro and may be valuable for testing the potency of rabies vaccines in vitro.

Animals↗

PubMed1983

[Trypsin inhibitors in soy bean-based food: critical review of thermal destruction kinetics, and analytical methods].

The possible kinetic mechanisms for thermal destruction of trypsin inhibitors (TI) are analyzed in this work, based on literature data and on the authors'data. The authors suggest that first order kinetics describes the destruction mechanism. On the other hand, it is demonstrated that temperature effects on the reaction rate constant for thermal destruction of TI can be quantified in terms of Arrhenius' equation. The kinetic data are used for illustrating thermal process optimization, maximizing microorganisms and TI destruction, and minimizing the destruction of a nutrient. The analytical methods for TI activity determination are discussed, with special emphasis on the AACC Official Method. The authors show that the original method for calculating TI activity is neither correct nor appropriate. The same can be said about several recent modifications. In order to solve this situation, the authors developed a mechanistic model, to explain the reactions occurring in the reaction mixture, when analyzing TI activity. Furthermore, it is demonstrated in this paper that the model solves the uncertainties and calculation problems found in the AACC Official Method and in its modifications. Lastly, some practical suggestions for the application of the new calculation method are proposed.

Hot Temperature↗

PubMedDate not supplied

[Optimization of immobilization conditions for acid proteinase from Aspergillus awamori].

To optimize the immobilization conditions for acid proteinase from Aspergillus awamori by covalent binding through glutaraldehyde, experiments were carried out using the Box-Wilson method. The optimization process was assessed on the basis of absolute activity A, coefficient of activity retention gamma and their product A gamma. The following conditions can be recommended: glutaraldehyde concentration 50--60 mg/g, enzyme concentration not less than 40 mg/g, time of glutaraldehyde treatment 2--2.5 hrs, immobilization time 2 hrs, pH about 4.0, and temperature 35--40 degrees C. Under these conditions A=220--230 U/g, gamma = 23--24% Agamma = 5,000--6,000.

Aspergillus↗

PubMed1995

The macroheterogeneity of recombinant human interferon-gamma produced by Chinese-hamster ovary cells is affected by the protein and lipid content of the culture medium.

The culture environment exerts a major effect on the glycosylation pattern of recombinant human interferon-gamma (IFN-gamma) produced by Chinese-hamster ovary (CHO) cells. The recombinant IFN-gamma is heterogeneous and consists of a mixture of fully (2N), partially (1N) and non-glycosylated (0N) glycoforms, and throughout batch cultures there is a decline in the proportion of fully glycosylated IFN-gamma. Glucose and glutamine, nutrients that are depleted early in such cultures, were prima facie candidates for causing such a shift in glycoform profile. Batch feeding of these nutrients did not prevent the decline in 2N glycoform, but the glycosylation pattern of IFN-gamma was affected by the initial glutamine concentration in the culture. Under different serum-free environments the extent of IFN-gamma glycosylation was affected by (1) the concentration of BSA, (2) the quality of BSA, (3) the lipid composition of the culture medium and (4) the presence of surfactants. Moreover, the inclusion of serum in cultures caused changes in the molecular masses of the major glycoforms, that was indicative of cleavage of the core polypeptide. The results reported emphasize the necessity of considering the effects of culture media on product quality as well as on product quantity during process optimization.

Animals↗

PubMed1994

[Quantitative evaluation of myocardial perfusion with ultrafast magnetic resonance tomography].

With the advent of ultrafast Magnetic Resonance Imaging (MRI), it is now possible to produce images with high temporal resolution. This gives the opportunity to record the passage of the paramagnetic contrast material Gadolinium-DTPA through the tissue of the heart muscle, yielding information on regional myocardial perfusion. We assessed the accuracy of MRI to detect and quantify reductions in coronary flow secondary to stenosis in dogs and patients. Regional blood flow was measured in dogs by left atrial injection of microspheres labeled with different radioactive isotopes. Signal intensity (SI) curves were generated in regions of interest over the myocardium and the cavum of the left ventricle. A newly developed two-compartment model based on the indicator-dilution method was used for interpretation of the SI-curves. In an optimization process the free parameters of the model equation were fitted to the measured SI-curves. The following flow parameters were determined: model parameter Q*, time to peak intensity (T), maximum signal intensity (SImax) and mean transit time (MTT) as calculated from a gamma variate fit. Absolute blood flow values were calculated for the parameters MTT and Q* assuming that the intravascular volume represents 10% of the total myocardial tissue volume. Measurements were performed on a 1.5 T Magnetom SP (Siemens AG, Erlangen) using a Turbo Flash sequence (TR = 6.5 ms, TE = 3 ms, TI = 100 ms, Flip Winkel = 9 degrees). Endsystolic images (voxel size = 1.8, 2.7, 15 mm3) were taken with an 18-cm Helmholtz surface coil in the short-axis view. A Gd-DTPA bolus (0.05 mmol/kg) was injected into the left atrium of 3 anesthetized closed-chest dogs. From the myocardial SI-curves the different parameters of myocardial perfusion were compared with flow assessed by microsphere injection over a wide range of myocardial blood flows (from 0.04 ml/min/g to 7.6 ml/min/g). A third-order polynominal fit showed a good correlation for the parameter Q* and MTT, whereas T and SImax were found to have a poor correlation. The linear regression analysis for a limited range of < 2 ml/min/g showed a superior estimation of myocardial perfusion for the parameter Q* than MTT. Blood flow > 2 ml/min/g was significantly underestimated by the MRT-measurements, but the parameter Q* showed the smallest amount of the divergent changes.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMedDate not supplied

[Selection and mutation from the theoretical information point of view--limits of the preservation of genetic information].

There is no doubt that evolution can only operate in accordance with the laws of thermodynamics. To transform this simple perception into a statement that can be quantified it is necessary to examine how the entropy (or the information content) changes by means of the two main factors of evolution: selection and mutation. In the present paper this aim was reached by using the methods of information theory. That evolution becomes possible the change of information by mutation and selection must not be negative in the long run. Consequently an upper limit for the information content of the genome must be assumed. If the evolution as a self-optimizing process gains this upper limit it reaches a dynamic equilibrium at which the increase of entropy by mutation balances the decrease of entropy by selection. In particular it was examined under which circumstances of dynamic equilibrium master-genotypes (genotypes that can preserve their specific sequence over a long time) can exist.

Biological Evolution↗

PubMed1996

[Study on the test and evaluation of the toxicity of the strains preparation of the different subspecies of Bacillus thuringiensis and on the research into its standardization].

In this paper using the preparation of Bacillus thuringiensis of USA standard sample-subsp. kurstaki HD-1-S-1980 (H3a3b) the toxicity to different subspecies preparations such as subsp. dendrolimus U strain(H4a4b), subsp. galleriae C88 strain (H5a5b) is tested and evaluated. And product's standardization is also researched. Comparing their toxicity to various test-insects between the standard sample prepared from U strain and USA, standard sample, the boilogical determined results are as follows: the toxicity of U strain standard sample is respectively 18666.6 IU/mg(test-insects: Dendrolimus punctatus, 2nd larva), 22956.5 IU/mg(test-insects: Plutella kylostella, 2nd larva). The above-mentioned toxicity evaluations are higher than that of 16000 IU/mg of USA standard sample. The comparison in susceptibility shows as follows: suscepticibility of plutella kylostella is stronger than that of Dendrolimus punctatus. The products from U strain and C88 strain are trial-produced in medium-scale. The product's toxicity to test-insect Dendrolimus punctatus is determined using USA standard sample. The results are obtained as follows the toxicity evaluation of U strain products is 36444.4 IU/mg; that of C88 strain products is 28521.7 IU/mg. The both are obviously higher than that of USA standard sample. This proves that different subspecies strain's toxicity to the same test-insect is with defference and it is an important way to raise product's toxicity by improving and optimizing process in production. The whole experiment shows it is feasible to rectify the evaluation of the toxicity of our country's present products using USA standard sample, Dendrolimus punctatus and Plutella kylostella as test-insets. And it is simple and convienient as well as save time and save effort to make statistical analysis in computer with Basic program. To do statistical and operational analysis using our designed basic programming by micro-computer is more accurate and repid than by caculator.

Animals↗

PubMed1997

The role of nutrition in wound healing.

Many factors, such as smoking, diabetes, anemia, steroids, and 'malnutrition, often impede the wound healing process. Optimizing patient's overall health status, in particular promoting nutrition, is an extremely effective way to improve the status of a wound. In this article, the role nutritional status plays in wound repair will be discussed.

Education, Nursing, Continuing↗

PubMed1998

[Experience in scaling up the film coating process for theophylline sustained-release pellets in mass production].

The scale-up of the film coating process for the production of Bronchoretard pellets (theophylline, CAS 58-55-9) is an example for the successful setup of a modern production technology designed to meet the increasing GMP requirements while taking into consideration ecological and economical aspects. This technology provides a reduction in polymer losses on drying from approx. 20% to under 5% and a distinct improvement in the reproducibility of the in vitro dissolution profiles. Double batch sizes and higher spray rates allow for a substantially higher batch turnover. A production line installed exclusively for Bronchoretard pellets and specific process optimization measures resulted in considerably lower lag-times of the equipment.

Anti-Asthmatic Agents↗

PubMed2002

The role of optimism in the process of schema-focused cognitive therapy of personality problems.

The aim of this study was to examine the determinants and effects of optimism in the process of schema-focused cognitive therapy of personality problems. The sample consisted of 35 patients with panic disorder and/or agoraphobia and DSM-IV Cluster C personality traits who participated in an 11-week residential program with one symptom-focused and one personality-focused phase. This study examines the role played by optimism during the individual sessions of the second phase, using a time series approach. Decreased patient's belief in his/her primary Early Maladaptive Schema and increased patient-experienced empathy from the therapist in a session predicted increased patient-rated optimism before the subsequent session. Increased patient-rated optimism in turn predicted decreased schema belief and distress and increased insight, empathy, and therapist-rated optimism. The slope of optimism across sessions was related to change in most of the overall outcome measures. There appears to be a positive feedback in the process of schema-focused cognitive therapy between decreased schema belief and increased optimism. In addition, optimism appears to mediate the effects of schema belief and therapist empathy on overall improvement, and to serve as an antecedent to decreased distress and to increased empathy, insight, and therapist's optimism.

Adult↗