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PubMed1991

Optimization of a trileaflet valve design.

This study investigates the fundamental principles that should govern the basic design of an optimal trileaflet valve. The geometry of the leaflets is described in terms of radius of the base (Rb), radius of the commissures (Rc), height of the valve (H), height of the commissures (Hs), and angle of the open leaflet to vertical (beta). Using computer-aided design software and these design parameters, a computer model of the valve was constructed. Choosing the parameters empirically did not produce an optimal valve. The four criteria for optimal performance were defined as: (1) a certain minimum coaptation height, (2) no folds in the leaflet, (3) minimum valve height, and (4) minimum leaflet flexion. Mathematical relationships were established between the design parameters and the performance parameters. These relationships indicated that the parameters Rc, Hs, and beta could be used to minimize valve height; however, a reduction in valve height must be balanced against the accompanying increase in leaflet flexion. For an optimal valve, the design parameters were Rb = 10 mm, then Rc = 8 to 10 mm, H = 11.5 mm, Hs = 2.4 to 2.6 mm, and beta = 4 degrees to 11 degrees . The optimal valve of any radius can be designed by scaling Rc, H, and Hs with respect to Rb. These design parameters were similar to those of the natural aortic valve. Trileaflet bioprosthetic valves designed on these principles are expected to have enhanced efficiency and longevity.

Bioprosthesis↗

PubMedDate not supplied

[Optimization of artificial respiration parameters in patients with acute pulmonary parenchymal damage syndrome].

The relationship between the mean pressure in the trachea, generated in mechanical ventilation of the lungs (Ptr.m), and normal arterial oxygenation is linear in ventilated patients with severe bilateral acute parenchymatous damage to the lungs. Under conditions of mechanical ventilation of the lungs (MVL) with regulated volume, constant end-expiratory pressure (PEEP) and inspiratory pause (eIP) are effective methods for regulating Ptr.m. However, the efficacy of regulating Ptr.m by PEEP and IF for each clinical case is different. The algorithm of using PEEP and IF for optimizing the respiratory pattern in this category of patients is not clear, too. The results indicate that optimization of MVL with controlled volume should be started with selecting the optimal level of PEEP for each patient. The level of Ptr.m should not be increased immediately at by of prolonging eIP, because the probability of compromising the hemodynamics is higher in such a case than the probability of improving blood oxygenation. Only after selecting the optimal PEEP is it permissible to try to improve arterial oxygenation by prolonging xx, because under such conditions the efficacy of prolonged inspiration is notably increased. Our data indicate that eIP no higher than 30% of the respiratory cycle (inspiration/expiration = 1.5/1) is the optimal. A further increase of eIP gives rise to a tendency towards decrease of arterial oxygenation and oxygen transport to tissues.

Acute Disease↗

PubMed1999

Optimal strategies for measuring diffusion in anisotropic systems by magnetic resonance imaging.

The optimization of acquisition parameters for precise measurement of diffusion in anisotropic systems is described. First, an algorithm is presented that minimizes the bias inherent in making measurements with a fixed set of gradient vector directions by spreading out measurements in 3-dimensional gradient vector space. Next, it is shown how the set of b-matrices and echo time can be optimized for estimating the diffusion tensor and its scalar invariants. The standard deviation in the estimate of the tensor trace in a water phantom was reduced by more than 40% and the artefactual anisotropy was reduced by more than 60% when using the optimized scheme compared with a more conventional scheme for the same scan time, and marked improvements are demonstrated in the human brain with the optimized sequences. Use of these optimal schemes results in reduced scan times, increased precision, or improved resolution in diffusion tensor images. Magn Reson Med 42:515-525, 1999.

Adult↗

PubMed2000

[Predictive value of preoperative abdominopelvic CT for optimal cytoreduction surgery in ovarian carcinoma].

Some patients underwent laparoscopy without optimal debulking surgery as initial treatment for advanced ovarian carcinoma. The amount of residual tumor following primary surgery was an important prognosis factor. Neoadjuvant chemotherapy is a new therapeutic approach. Secondary, optimal surgery could be done in better conditions. The purpose was to access the ability of preoperative abdominopelvic CT to predict success of debulking surgery for ovarian carcinoma: less than 1 cm of residual tumor size after initial surgery. We reviewed 39 patients (2 stages Ic, 1 stage IIc, 22 stages III and 14 stages IV) operated on for ovarian carcinoma between January 1992 and December 1997. Surgical criteria of inability to perform optimal surgical cytoreduction were compared with abdominopelvic CT done the month before. CT scans were prospectively assessed by radiologist A and retrospectively (3 months to 6 years delay) rewiewed separately by radiologists A and B without surgical data. Nineteen patients underwent optimal debulking surgery: 13 no residual tumor and 6 with residual lesions under 1 cm. The interreader (0.73) and intrareader (0.9) agreement, worked out by Kappa coefficient, was juged good to very good. The sensitivity of CT was 91% with a specificity of 95%. These results allowed us to determine wich CT criteria were accurate and reproducible to be a helpfull for therapeutic choice and to avoid laparotomy without optimal surgery.

Aged↗

PubMed2000

Optimal design of connectivity in neural network training.

Many authors consider neural network (NN) supervised training as an optimization process during which the weights are iteratively adjusted in order to minimise an error (cost) function, which represents the difference between the obtained and the aimed output. The error function surface is usually nonconvex, can be highly convoluted, with many plateaux and long narrow troughs, and can encounter many saddle and local minima (LM) points. Because backpropagation (BP), which is widely used method for supervised learning, uses local methods for optimization, it can get stuck in LM. This can make learning very difficult and sometimes its convergence to optimal solution--not possible. In this paper we propose a stochastic method for global optimization (GO), which make use of a uniformly distributed LP tau sequence of points. The developed technique is tested with common benchmark problems and used for neural network supervised learning. The conducted tests show that the proposed method can be successfully used for an optimal supervised training of small size NN.

Neural Networks, Computer↗

PubMed2000

[Is there a correlation between optimism and quality of life in upper aerodigestive tract cancer Patients? Preliminary results].

UNLABELLED: The aim of this study was to test the hypothesis that optimism is a predictor of quality of life (QOL) in a sample of upper aerodigestive tract (UADT) cancer patients. MATERIALS AND METHODS: Consenting patients with squamous cell carcinoma of the UADT were included during the week following disclosure of the diagnosis of their illness, and before the start of treatment. QOL and optimism were evaluated by questionnaires presented to the patients before the start of treatment, after the treatment, and 6 and 12 months after the end of the treatment. PRELIMINARY RESULTS: 92 patients were included. The average age was 58.7+/-11.4 years. Their QOL scores were significantly correlated, first with age (r =- 0.23, p =0.03) and second with degree of optimism (r =0.32, p =0.002). No correlation was found between QOL scores, degree of optimism, and sociodemographic and clinical data. Optimism was the sole variable significantly associated with QOL before treatment (F =4.1, p =0.002, r(2) =0.19). The difference between QOL scores before and after treatment was not significant. CONCLUSION: Continuation of the study and analysis of survival of the patients may help pinpoint new prognostic factors, both objective and subjective, that will facilitate an overall approach to patient care by allowing for their preferences.

Adult↗

PubMed2000

Optimizing breeding decisions for Finnish dairy herds.

The purpose of this study was to determine the effect of reproductive performance on profitability and optimal breeding decisions for Finnish dairy herds. We used a dynamic programming model to optimize dairy cow insemination and replacement decisions. This optimization model maximizes the expected net revenues from a given cow and her replacements over a decision horizon. Input values and prices reflecting the situation in 1998 in Finland were used in the study. Reproductive performance was reflected in the model by overall pregnancy rate, which was a function of heat detection and conception rate. Seasonality was included in conception rate. The base run had a pregnancy rate of 0.49 (both heat detection and conception rate of 0.7). Different scenarios were modeled by changing levels of conception rate, heat detection, and seasonality in fertility. Reproductive performance had a considerable impact on profitability of a herd; good heat detection and conception rates provided an opportunity for management control. When heat detection rate decreased from 0.7 to 0.5, and everything else was held constant, net revenues decreased approximately 2.6%. If the conception rate also decreased to 0.5 (resulting in a pregnancy rate of 0.25), net revenues were approximately 5% lower than with a pregnancy rate of 0.49. With lower fertility, replacement percentage was higher and the financial losses were mainly from higher replacement costs. Under Finnish conditions, it is not optimal to start breeding cows calving in spring and early summer immediately after the voluntary waiting period. Instead, it is preferable to allow the calving interval to lengthen for these cows so that their next calving is in the fall. However, cows calving in the fall should be bred immediately after the voluntary waiting period. Across all scenarios, optimal solutions predicted most calvings should occur in fall and the most profitable time to bring a replacement heifer into a herd was in the fall. It was economically justifiable to keep breeding high producing cows longer than low producing cows.

Animal Husbandry↗

PubMedDate not supplied

Intraoperative conformal optimization for transperineal prostate implantation using magnetic resonance spectroscopic imaging.

PURPOSE: Recent studies have demonstrated that magnetic resonance spectroscopic imaging (MRSI) of the prostate may effectively distinguish between regions of cancer and normal prostatic epithelium. This diagnostic imaging tool takes advantage of the increased choline and creatine versus citrate ratio found in malignant, compared with normal, prostate tissue. The purpose of this report is to present our initial experience integrating MRSI data into an intraoperative computer-based optimization planning system for prostate cancer patients who underwent permanent interstitial I 125 implantation. The goal of this approach was to achieve dose escalation to intraprostatic tumor deposits on the basis of MRSI findings without exceeding the tolerance of adjacent normal tissue structures. MATERIALS AND METHODS: MRSI was obtained before surgery for four consecutive patients with clinically localized prostate cancer. The ratios of choline and citrate for the prostate were analyzed, and regions in which malignant cells were suspected to be present were identified. These ratios were calculated on a spatial grid overlying the axial MRSI of the prostate. MRSI coordinates containing these suspicious regions were registered to the intraoperative ultrasound images. A computer-based treatment planning system, which relied on a genetic algorithm, was used to determine the optimal seed distribution necessary to achieve maximal target volume coverage with the prescription dose and to maintain urethra and rectal doses within tolerance ranges. The treatment planning system was specifically designed to escalate the dose to MRS-positive voxels while at the same time achieving preferential sparing of surrounding normal tissues. Patients underwent transperineal interstitial implantation with I 125 by use of this intraoperatively generated plan. Postimplant computed tomographic scans were performed on the same day of the procedure in all cases, and dosimetric guidelines of the American Brachytherapy Society were used to assess implant quality. RESULTS: Based on the postimplant computed tomographic evaluation, the intraoperative optimization treatment planning program was able to achieve a minimum dose of 139% to 192% of the 144-Gy prescription dose to the MRS-positive voxels. The percentage of the prostate volume receiving 100% of the prescription dose ranged from 92% to 97%, and the dose delivered to 90% of the target for the target volume ranged from 96% to 124%. Despite the dose escalation achieved for the positive voxels, the urethral and rectal doses were maintained within tolerance ranges. The average and maximal rectal doses ranged from 28% to 43% and 69% to 115% of the prescription dose, respectively. The average and maximal urethral doses ranged from 66% to 144% and 118% to 166% of the prescription dose, respectively. CONCLUSIONS: Using this brachytherapy optimization system, we could demonstrate the feasibility of MRS-optimized dose distributions for I 125 permanent prostate implants. This approach may have an impact on the ability to select regions within the prostate to safely employ dose escalation for patients treated with permanent interstitial implantation and to improve outcome for patients with organ-confined prostatic cancers.

Aged↗

PubMed2000

[Predictive value of abdominopelvic scan for optimal surgery of ovarian carcinoma].

BACKGROUND: Some patients undergo laparoscopy without optimal debulking surgery as initial treatment for advanced ovarian carcinoma. The amount of residual tumor following primary surgery is an important prognosis factor. Neoadjuvant chemotherapy is a new therapeutic approach. Secondary, optimal surgery could be done in better conditions. PURPOSE: To access the ability of preoperative abdominopelvic CT to predict success of debulking surgery for ovarian carcinoma: less than 1cm of residual tumor size after initial surgery. MATERIALS AND METHODS: We reviewed 39 patients (two stage Ic, 1 stage IIc, 22 stage III and 14 stage IV) operated on for ovarian carcinoma between January 1992 and December 1997. Surgical criteria of inability to perform optimal surgical cytoreduction were compared with abdominopelvic CT done the month before. CT scans were prospectively assessed by radiologist A and retrospectively (3 months to 6 years delay) reviewed separately by radiologists A and B without surgical data. RESULTS: Nineteen patients underwent optimal debulking surgery: 13 no residual tumor and 6 with residual lesions under 1cm. The interreader (0.73) and intrareader (0.9) agreement, worked out by Kappa coefficient, was judged good to very good. The sensitivity of CT was 91% with a specificity of 95%. CONCLUSION: These results allowed us to determine which CT criteria were accurate and reproducible to be a helpful for therapeutic choice and to avoid laparotomy without optimal surgery.

Adenocarcinoma↗

PubMed2001

Influence of vitamin-optimized plasma homocysteine cutoff values on the prevalence of hyperhomocysteinemia in healthy adults.

BACKGROUND: Hyperhomocysteinemia is a cardiovascular disease (CVD) risk factor. We determined plasma homocysteine (Hcy) reference values at optimized vitamin status and investigated their influence on the prevalence of hyperhomocysteinemia in healthy adults. Results were compared with those obtained using European Concerted Action Project (ECAP) cutoff values. METHODS: Healthy adults (n = 101) received folic acid (5 mg/day) and vitamin B(12) (1 mg/day) for 2 weeks and the same dosages of folic acid and vitamin B(12) plus vitamin B(6) (1 mg. kg(-1). day(-1)) during the following 2 weeks. Hcy concentrations, both fasting and 6-h post-methionine load, were determined at baseline and after 4 weeks. RESULTS: Baseline (4 weeks) fasting and 6-h postload Hcy reference values were 4.7-14.6 (4.1-9.3) and 18.8-49.7 (12.9-35.1) micromol/L, respectively. Mean fasting and 6-h postload Hcy decreased after 4 weeks of vitamin supplementation by 3.5 micromol/L (33.5%) and 8.5 micromol/L (26.3%), respectively. The percentages of subjects exhibiting significant decreases in fasting Hcy following vitamin supplementation were 88% (all subjects), 92% (non-vitamin users), and 72% (vitamin users). The prevalences of hyperhomocysteinemia with use of ECAP cutoff values were 29% for all groups, 29% for men, 27% for premenopausal women, and 53% for postmenopausal women. With vitamin-optimized cutoff values, prevalences were 58%, 58%, 76%, and 89%, respectively. Use of vitamin-optimized cutoff values increased the diagnostic value of fasting Hcy and decreased that of a 6-h postload Hcy compared with use of ECAP cutoff values. CONCLUSIONS: Use of vitamin-optimized cutoff values gives rise to high hyperhomocysteinemia pretest probabilities in the general population and, therefore, precludes any meaningful role for Hcy testing. Future demonstration of a beneficial effect of decreasing Hcy on CVD risk would justify use of vitamin-optimized cutoff values for assessment of CVD risk.

Adolescent↗

PubMedDate not supplied

[Evolution of life cycle: models based on optimization of energy allocation].

A brief history of optimization approach in modern evolutionary ecology is given and author's own results concerning life history evolution are considered in more details. The problem of evolutionary optimization is formulated in terms of mathematical theory of optimal control as a problem of optimal sharing of organism's resources between growth, reproduction, repair, and maintenance. The Malthusian parameter is used as optimality criterion. This approach allows, in particular, to give evolutionary ecological explanations for some well known empirical facts such as attenuation of growth with age (law of Bertalanffi), acceleration of ageing with age (law of Gompertz), human sexual dimorphism in mean lifespan, age and size of maturity.

Aging↗

PubMed2001

[The reliability of vaginal cytology in determining the optimal mating time in the bitch].

The reliability of vaginal cytology for determining the optimal mating period is controversial. The importance of the site for obtaining the smear (the vestibule or the vagina) and the best staining method are also unclear. Therefore, we investigated the reliability of vaginal cytology as compared to plasma progesterone concentrations for determining the optimal mating period. Additionally, the influence of different locations for obtaining the smears and of the staining methods, i.e. May-Grünwald-Giemsa or Papanicolaou, a method that stains keratin in superficial cells, was examined. In total, the vaginal cytology of 35 bitches during the follicular phase was examined three times a week, until the optimal time for mating was established, based on plasma progesterone concentrations measured with a 125Iodine radio-immunoassay. The results indicate that vaginal cytology is not useful for determining the optimal mating period in bitches, since mating according to cytological findings would have resulted in only 28% of the bitches being mated at the proper time. The site for obtaining the smear and the staining method did not affect accuracy. It is therefore concluded that cytology is not useful in breeding management to determine the optimal mating period. It can be used, however, to determine the stage of the cycle in general, e.g. the early part of the follicular phase or the metoestrus and the detection of disorders in the follicular phase. For this purpose, a smear from the vestibule, stained with a morphological staining method, provides sufficient information.

Animals↗

PubMed2001

Quantitative design of optimal analgesic combination of acetaminophen, caffeine, and butalbital.

AIM: To quantitatively seek an optimal analgesic combination of acetaminophen (Ace), butalbital (Bul), and caffeine (Caf), and to characterize the pharmacodynamics of interaction among the three drugs. METHODS: The models of acute inflammatory pain in carrageenin-injected rats were applied to measure the vocalization threshold to paw pressure. Six groups with different ratios and doses were set to seek an optimal combination of Ace, Caf, and Bul, analyzed by the weighted modification method. Based on the ratio and doses in the optimal combination, four continuous doses were set to analyze the interactions of therapeutic effects by the reflection method. The interaction of the acute toxicity was evaluated by the parameter method. RESULTS: According to the degree of importance to the combined analgesic effect, Ace > Caf > Bul; Ace showed a significant dose-response relationship, whereas in Caf and Bul, this relationship was not apparent. A new combination was obtained by the theoretical analysis and confirmed further by experimentation. Namely, at a ratio of 8.6:1:1.5 Ace + Caf + Bul (240 + 28 + 42 mg/kg, ig) was an optimal combination. Both Caf and Bul had a synergism to Ace, but Caf was a stronger synergist in contrast to Bul. Such synergism increased the therapeutic effects in the range of Ace 153.6 - 300 mg/kg combined with Caf 17.9 - 35 mg/kg and Bul 26.8 -5 2.5 mg/kg (8.6:1:1.5). However, the dose of Ace + Caf + Bul at 300 + 35 + 52.5 mg/kg resulted in sedation in rats. The peak latency was approximately 1 h for all four continuous doses, but the peak amplitude was dose-related, and the duration of the therapeutic effect was less than 2 h. The acute toxicity of the three drugs in combination remained the same. CONCLUSION: Ace + Caf + Bul at a dose of (240 + 28 + 42) mg/kg (ig) results in an optimal combination. The therapeutic window of the combination is located in the range of Ace (153.6 - 240 mg/kg)+Caf (17.9 - 28 mg/kg)+Bul (26.8 - 42 mg/kg) (8.6:1:1.5). Caf has a stronger synergism with Ace than Bul.

Acetaminophen↗

PubMed2000

[Optimal models on sustainable management of oases ecosystem in southern margin of Taklamakan Desert].

On the basis of analyzing the distribution feature of water resource and the canal water utilization coefficient of oases in southern margin of Taklamakan Desert, observing the wind prevention efficiency of shelterbelt through a simulation experiment in wind tunnel, and 15 years researching the comprehensive control of desertified land in Cele Oasis, a series of optimal models on sustainable management of oases ecosystem is southern margin of Taklamakan Desert were proposed i.e., the optimal model on "moderated osais", the optimal model on structure of wind-breaks, the optimal model on comprehensive control of desertified land, and the optimal model on planting structure of corps.

Agriculture↗

PubMed2001

[A general approach to the structural shape optimization using genetic algorithms and geometric design elements].

Structural optimization is an engineering field which deal with the improvement of existing solutions or even more find new solutions that are better than the previous ones under some selected criterion. Shape optimization is a research area in this field and it is involved in developing new methodologies to find better structural design based on the shape as resistant element, as for example solutions with the less stress concentration zones and made with the minimum amount of material. The goal of this doctoral dissertation is to present and discuss a general structural shape optimization methodology able to optimize several structural systems or mechanical devices. The approach presented herein is based on global search optimization tools such as Genetic Algorithms and geometric design elements by means of beta-splines curves and surfaces representation. Finally the great versatility of the developed tool is presented and discussed with an application example.

Algorithms↗

PubMed2002

Numerical modeling of ferrous-ion oxidation rate in Acidithiobacillus ferrooxidans ATCC 23270: optimization of culture conditions through statistically designed experiments.

Statistically designed experimental strategy has been performed in order to evaluate and optimize nutritional and environmental parameters that affect ferrous ion oxidation rate in Acidithiobacillus ferrooxidans ATCC 23270. Plackett-Burman design was carried out to evaluate efficiently the biological significance of 10 culture conditions influencing ferrous-ion oxidation rate of A. ferrooxidans grown for 5 days in shake-flask batch mode on the newly modified 9-K media. Among ten fermentation factors examined, the most significant variables influencing ferrous-ion oxidation rate were statistically elucidated to be pH and calcium nitrate as positive contributors, whereas trace metals solution and potassium chloride were the most significant negative contributors. The optimal levels of the most significant three nutritional factors were further predicted from a polynomial model created from the data obtained from three level factorial design, a Box-Behnken design. Predicted optimal ferrous-ion oxidation rate Q(Fe2+) was recorded to be 0.148 (g Fe2+/l/hr). On verifying the predicted value, an experiment was performed under optimal predicted conditions and showed an actual experimental Q(Fe2+) of 0.152 g/l/hr, which was 2.7% over the predicted value. Our optimized medium formula gave overall five folds increase in ferrous-ion oxidation rates over the previously published data of standard 9-K medium on batch culture of A. ferrooxidans ATCC 23270 with higher mu(max) (hr(-1)) of 0.177 which was achieved within 75 h incubation in shake-flask culture.

Calcium Compounds↗

PubMed2003

Body mass index--specific weight gains associated with optimal birth weights in twin pregnancies.

OBJECTIVE: To formulate maternal weight gain guidelines, by maternal pregravid body mass index (BMI) status, associated with optimal fetal growth and birth weight in twins. STUDY DESIGN: This historical cohort study was based on 2,324 pregnancies with nonanomalous, liveborn twins (4,684 infants) from Ann Arbor, Charleston, Baltimore and Miami. Rates of maternal weight gain and fetal growth were modeled using multiple regression for 0-20 weeks, 20-28 weeks and 28-38 weeks (projected as necessary), controlling for potentially confounding factors. Optimal rates of fetal growth were defined as growth between the singleton and twin 50th percentiles, and optimal birth weights were defined as between the singleton 50th percentile and twin 90th percentile at > or = 36 weeks (2,850-2,950 g). RESULTS: Optimal rates of fetal growth and birth weights were associated with rates of maternal weight gain for underweight women of 1.25-1.75 lb/wk (0.57-0.79 kg/wk) to 20 weeks, 1.50-1.75 lb/wk (0.68-0.79 kg/wk) between 20 and 28 weeks and 1.25 lb/wk (0.57 kg/wk) from 28 weeks to delivery; for normal-weight women, 1-1.5 lb/wk (0.45-0.68 kg/wk) to 20 weeks, 1.25-1.75 lb/wk (0.57-0.79 kg/wk) between 20 and 28 weeks and 1.0 lb/wk (0.45 kg/wk) from 28 weeks to delivery; for overweight women, 1-1.25 lb/wk (0.45-0.57 kg/wk) to 20 weeks, 1-1.5 lb/wk (0.45-0.68 kg/wk) between 20 and 28 weeks and 1 lb/wk (0.45 kg/wk) from 28 weeks to delivery; for obese women, 0.75-1 lb/wk (0.34-0.45 kg/wk) to 20 weeks, 0.75-1.25 lb/wk (0.34-0.57 kg/wk) between 20 and 28 weeks and 0.75 lb/wk (0.34 kg/wk) from 28 weeks to delivery. CONCLUSION: Optimal rates of fetal growth and birth weights in twins are achieved at rates of maternal weight gain that vary by period of gestation and maternal pregravid BMI status.

Adult↗

PubMed2003

[Optimizing cultural conditions of measles vaccine working seed lot with orthogonal experiments].

OBJECTIVE: To improve the quality of measles vaccine and find out good combination of cultural factors of measles vaccine virus seeds. METHODS: Orthogonal experiments were made to confirm optimized cultural factors. 5 lots of optimized measles vaccine working seed lot were prepared. RESULTS: The titers of the optimized vaccine seed improved significantly (> or = 0.69 +/- 0.35 LgCCID50/1.0 ml, P < 0.05), compared with 5 lots of traditional working seed lot. With these seeds we trial-prepared 5 lots of lyophilized vaccines respectively, the titer and stability met the Chinese Requirements of Biological Products. CONCLUSION: The orthogonal experiment is a kind of good method for optimizing cultural conditions of measles vaccine working seed lot. The yield and quality of measles vaccine can be improved in the optimized working seed lot with high titer and good stability.

Culture Media↗