[Risk assessment for thyroid (131)I exposure among nuclear medical staff].

Objective: To explore the main risk factors and to assess the risk of thyroid (131)I exposure among nuclear medical workers. Methods: From March to October in 2019, cluster sampling was adopted to collect the number of (131)I automatic packer and patients treated for thyroid cancer, hyperthyroidism and liven cancer used (131)I, the practicing categories, job rotation and (131)I operation condition of nuclear medical staff were also investegated in the 21 nuclear medicine hospitals in Fujian Province that carried out (131)I nuclide diagnosis and treatment in 2018. (131)I aerosol and personnel thyroid (131)I were measured in 20 hospitals using (131)I for thyroid cancer or hyperthyroidism. The main risk factors leading to thyroid (131)I exposure of nuclear medical staff were found and aninternal exposure risk assessment model was established. Results: The detection rate of (131)I aerosol and personnel thyroid (131)I were 80.0% (16/20) and 25.5% (62/243) in 20 hospitals. The situation of packaging and administration about (131)I in the nearly 10 effective half-life, the concentration of (131)I aerosol in the nuclear medicine workplace, the number of patients treated with (131)I for thyroid cancer or hyperthyroidism were the main risk factors leading to thyroid (131)I internal exposure (OR=5.857, 6.808, 1.983, 1.150, P<0.05) . Conclusion: (131)I exposure is common among nuclear medical workers, attention should be paid to the protection of internal radiation, strengthen the control of main risk factors, so as to reduce the risk of internal radiation.

Programmable and robust static topological solitons in mechanical metamaterials.

Solitary, persistent wave packets called solitons hold potential to transfer information and energy across a wide range of spatial and temporal scales in physical, chemical, and biological systems. Mechanical solitons characteristically emerge either as a single wave packet or uncorrelated propagating topological entities through space and/or time, but these are notoriously difficult to control. Here, we report a theoretical framework for programming static periodic topological solitons into a metamaterial, and demonstrate its implementation in real metamaterials computationally and experimentally. The solitons are excited by deformation localizations under quasi-static compression, and arise from buckling-induced kink-antikink bands that provide domain separation barriers. The soliton number and wavelength demonstrate a previously unreported size-dependence, due to intrinsic length scales. We identify that these unanticipated solitons stem from displacive phase transitions with periodic topological excitations captured by the well-known [Formula: see text] theory. Results reveal pathways for robust regularizations of stochastic responses of metamaterials.

[Analysis of influencing factors of ureteral anastomotic stenosis following urinary diversion after laparoscopic radical cystectomy].

Objective: To investigate the influencing factors of ureteroenteric strictures (UES) in patients undergoing laparoscopic radical cystectomy plus urinary diversion (UD). Method: A total of 412 patients who underwent UD after radical prostatectomy from January 2008 to December 2016 were retrospectively included in this study. Age, gender, body mass index (BMI), diversion type, time to diagnosis of UES, duration of ureteral stent, postoperative complications, including urinary tract infections, ureteroenteric leakage and UES were collected. Kaplan-Meier curves were used to describe time to developing UES. Prognostic factors of UES were analyzed using COX proportional hazard regression model. Result: Median follow-up time was 37 (IQR 17-120) months. A total of 59 patients (70 sides) developed UES, including 34 cases on the left side, 14 cases on the right side and 11 cases on both sides, following UD after radical cystectomy. The median time to diagnosis of UES was 7 (IQR 4-11) months. The total incidence of UES was 14.3%. The incidence of UES was 10.9%, 13.3% and 14.1% at 1, 3 and 5 years after UD, respectively. Cox proportional hazard regression model analysis demonstrated that BMI≥25kg·m(-2) (P=0.008), ureteroenteric leakage (P=0.001) and urinary tract infections (P=0.037) were the independent risk factors associated with UES following UD after radical cystectomy. Conclusion: The incidence rate of UES following UD after radical cystectomy was relatively high, which occurs more common on the left side. Obese patients, combined with ureteroenteric leakage, urinary tract infection after UD, are more likely to develop into UES.

Immune efficacy of a porcine circovirus type 2 vaccine purified using Gram-positive enhancer matrix surface display technology.

AIMS: Purification of porcine circovirus type 2 (PCV2) using Gram-positive enhancer matrix (GEM) surface display technology and immunogenicity evaluation of the purified antigen. METHODS AND RESULTS: A recombinant bifunctional protein containing a protein anchor domain and a 'virus anchor' domain was designed as a protein linker (PL) between PCV2 and GEM particles. By incubating with PL and GEM particles sequentially, PCV2 could be purified and enriched through a simple centrifugation process with GEM surface display technology. Our data showed that one unit (2·5 × 109 particles) of GEM particles with 80 µg PL could purify 100 ml of PCV2-containing culture supernatant (viral titre: 106·5 TCID50 per ml-1 ) with a recovery rate up to 99·6%. The impurity removal efficiency of this method, calculated according to decreased total protein content during purification, was approximately 98%. Furthermore, in vivo experimentation showed that piglets immunized with purified PCV2 could elicit strong immune responses to prevent against PCV2 infection. CONCLUSION: Porcine circovirus type 2 could be efficiently purified and enriched with GEM display technology via a crucial PL, and the purified PCV2 could elicit effective immune responses against PCV2 infection. SIGNIFICANCE AND IMPACT OF THE STUDY: The GEM-based purification method established here is cost-efficient and high-throughput, and may represent a promising large-scale purification method for PCV2 vaccine production.

[Impact of diverse shapes of prostatic apex on positive apical margin rate and biochemical recurrence following laparoscopic radical prostatectomy].

Objective: To explore the effects of various forms of prostatic apex on positive apical margin rate (PAM) and biochemical recurrence (BCR) after laparoscopic radical prostatectomy. Methods: A retrospective analysis of 309 patients (aging (65±6) years) who were experienced laparoscopic radical prostatectomy from January 2010 to December 2016 at the Department of Urology, First Affiliated Hospital of Fujian Medical University. According to the relationship between prostate apex and membrane urethra at the mid-sagittal plane of preoperative MRI, all patients were classified into 4 categories. There were 31 patients for type 1, apex covering both anterior and posterior aspects of membranous urethra, 139 patients for type 2, apex covering anterior side of membranous urethra, 63 patients for type 3, apex covering posterior aspect of membranous urethra, 76 patients for type 4, apex not covering membranous urethra. PAM and BCR after operation were compared between this four groups respectively. The χ(2) test was used to compare PAM among the 4 types. Logistic regression analysis were undertaken to analyze the factors affecting PAM. Cox's proportional hazards regression model was undertaken to identify the variables influencing BCR. Results: There was no significant difference in the 4 groups concerning age, body mass index, prostate volume, preoperative prostate-specific antigen (PSA) value, postoperative Gleason score and pathological stage (P>0.05).The median follow-up time was 32 months (ranged from 12 to 60 months).The data showed that the apical type 3 patients has the highest PAM. There was statistical difference among the 4 groups in PAM (χ(2)=15.592, P=0.001). Preoperative level of PSA (OR=20.356, 95% CI: 2.440 to 169.810, P=0.005), postoperative Gleason score (OR=4.113, 95% CI: 1.911 to 8.849, P=0.001), pathological stage (OR=3.422, 95% CI: 1.600 to 7.319, P=0.002) and apical type 3 (OR=6.134, 95% CI: 2.196 to 17.132, P=0.001) were independent relactive factors of PAM. Preoperative level of PSA (HR=1.362, 95% CI: 1.006 to 1.843, P=0.045), postoperative Gleason score (HR=1.920, 95% CI: 1.384 to 2.665, P=0.001), pathological stage (HR=1.476, 95% CI: 1.098 to 1.983, P=0.010), PAM (HR=3.497, 95% CI: 2.407 to 5.081, P=0.001)and apical type 3 (HR=1.828, 95% CI: 1.266 to 2.639, P=0.001) were independent prognosis factors of BCR. Conclusion: Prostate apical type 3 could be a significant independent predictor of PAM, and an independent prognosis factor for BCR.

[Effects of urethral fibrosis on urinary control after laparoscopic radical prostatectomy].

Objective: To determine the influence of urethral fibrosis on the recovery of urinary continence after laparoscopic radical prostatectomy. Method: A retrospective study of 203 patients from January 2010 to January 2014 who were underwent laparoscopic radical prostatectomy for prostate cancer in the First Affiliated Hospital of Fujian Medical University. The patients were divided into 2 groups according to preoperative T2-weighted magnetic resonance imaging of fibrosis status of the urethral wall and periurethral tissue. One hundred and forty-four(≤2 grade) and 59 (≥3 grade) were classified into the no/mild and severe urethral fibrosis groups respectively. Urinary continence at 1, 3, 6, 12 months after operation were compared between this two groups respectively. Result: There was no significant difference in the two groups with respect to age, body mass index (BMI), Charlson comorbidity index (CCI), international prostate symptom score (IPSS), prostate volume, preoperative prostate-specific antigen value, nerve-sparing procedure, postoperative Gleason score and pathological stage. The operation was completed successfully in all cases. With a median follow-up time of 15 months (ranged from 12 to 24 months), there was no statistical difference between the two groups in urinary continence at 1 month after operation (P>0.05). The incidences of continence in patients with no/mild fibrosis were significantly higher at 3, 6, 12 months after operation than those with severe fibrosis. (In the no/mild fibrosis group and severe fibrosis group, the continue rate at 3 mouths was 50.0% vs 28.8% P=0.005; at 6 mouths was 91.0% vs 59.3% P<0.001; at 12 mouths was 98.6% vs 88.1% P=0.003). Conclusion: Preoperative urethral fibrosis could be a significant predictor of recovery of the long-term urinary continence status after laparoscopic radical prostatectomy. Compared with no/mild fibrosis, severe fibrosis had worse long-term continence status.

In silico identification and analysis of phytoene synthase genes in plants.

In this study, we examined phytoene synthetase (PSY), the first key limiting enzyme in the synthesis of carotenoids and catalyzing the formation of geranylgeranyl pyrophosphate in terpenoid biosynthesis. We used known amino acid sequences of the PSY gene in tomato plants to conduct a genome-wide search and identify putative candidates in 34 sequenced plants. A total of 101 homologous genes were identified. Phylogenetic analysis revealed that PSY evolved independently in algae as well as monocotyledonous and dicotyledonous plants. Our results showed that the amino acid structures exhibited 5 motifs (motifs 1 to 5) in algae and those in higher plants were highly conserved. The PSY gene structures showed that the number of intron in algae varied widely, while the number of introns in higher plants was 4 to 5. Identification of PSY genes in plants and the analysis of the gene structure may provide a theoretical basis for studying evolutionary relationships in future analyses.

Micropolar continuum modelling of bi-dimensional tetrachiral lattices.

The in-plane behaviour of tetrachiral lattices should be characterized by bi-dimensional orthotropic material owing to the existence of two orthogonal axes of rotational symmetry. Moreover, the constitutive model must also represent the chirality inherent in the lattices. To this end, a bi-dimensional orthotropic chiral micropolar model is developed based on the theory of irreducible orthogonal tensor decomposition. The obtained constitutive tensors display a hierarchy structure depending on the symmetry of the underlying microstructure. Eight additional material constants, in addition to five for the hemitropic case, are introduced to characterize the anisotropy under Z2 invariance. The developed continuum model is then applied to a tetrachiral lattice, and the material constants of the continuum model are analytically derived by a homogenization process. By comparing with numerical simulations for the discrete lattice, it is found that the proposed continuum model can correctly characterize the static and wave properties of the tetrachiral lattice.

Genetic polymorphisms of VKORC1, CYP2C9, CYP4F2 in Bai, Tibetan Chinese.

BACKGROUND: VKORC1, CYP2C9 and CYP4F2 are three critical genes associated with inter-individual variation of warfarin dose. Many dosing algorithms containing these gene polymorphisms and demographic characteristics have been set up for better use of warfarin. However, with distinct gene mutation frequencies among different ethnics, dosing algorithms differ greatly. For Chinese, related research just concentrate on Han Chinese, ignoring other Chinese ethnicities. This study aims to detect the popular polymorphisms in these three critical genes in Bai, Tibetan Chinese, to start the exploration of better use of warfarin in Chinese minorities. METHODS: PCR-based methods were used to analyze VKORC1 3673G > A, CYP2C9*3, CYP4F2 rs2108622 C > T in Han, Bai and Tibetan Chinese. RESULTS: The differences among the mutation frequencies of the studied genes in three ethnicities were not statistically significant. The frequency of A-allele of VKORC1 3673G > A was 92.8%, 90.2%, 90.8% in Bai, Tibetan, Han Chinese, respectively. The frequency of *3-allele in CYP2C9*3 was low in Bai (4.5%), Tibetan (2.8%) and Han Chinese (4.6%). Approximately one fourth of each ethnic had the mutant T-allele of CYP4F2 rs108622. However, Bai Chinese got statistically higher A-allele frequency of VKORC1 3673G > A than previously studied Han Chinese did. CONCLUSIONS: Bai Chinese got significant higher A-allele frequency of VKORC1 3673G > A.

Pharmacokinetics and its relation to toxicity of pegylated-liposomal doxorubicin in Chinese patients with breast tumours.

OBJECTIVES: Pegylated liposomal doxorubicin (PLD) is a formulation of doxorubicin encapsulated with polyethylene glycol-coated liposomes, which has prolonged circulation time and unique toxicity profile. This study deals with the pharmacokinetics and its relation to toxicity in Chinese patients with breast tumours. METHODS: Twenty-two Chinese female patients with breast tumours were received two PLD products in single dose of 50 mg/m2 with a randomized, two-period and cross-over design. Blood was sampled immediately before and at 15, 30, 60 min, 1·17, 2, 5, 13, 25, 49, 73, 97, 121, 145 and 241 h after the PLD infusion. The plasma level of doxorubicin was determined with LC-MS. RESULTS: The pharmacokinetics of PLD was best described by a one-compartment linear structural model with a long elimination T(1/2) (64 h), a slow clearance (0·025 L/h/m2) and a small volume of distribution (2·310 L/m2). The main toxicities were neutropenia (22/44), nausea (22/44), vomiting (8/44) and pigmentation (4/44). The nausea and neutropenia were positively correlated with AUC while negatively correlated with Cl (P<0·05). CONCLUSIONS: The study confirms the different pharmacokinetic and toxicity profiles of PLD compared with non-liposomal doxorubicin. The pharmacokinetic profiles in Chinese patients with breast tumours is different from those reported for European patients with metastatic breast cancer. The correlation between toxicities, neutropenia grade and nausea and two of the pharmacokinetic parameters, AUC and Cl, may be useful for guiding the dosing of the agent.

Trans-phonon effects in ultra-fast nanodevices.

We report a novel phenomenon in carbon nanotube based ultra-fast mechanical devices, the trans-phonon effect, which resembles the transonic effects in aerodynamics. It is caused by dissipative resonance of nanotube phonons similar to the radial breathing mode, and subsequent drastic surge of the dragging force on the sliding tube, and multiple phonon barriers are encountered as the intertube sliding velocity reaches critical values. It is found that the trans-phonon effects can be tuned by applying geometric constraints or varying chirality combinations of the nanotubes.

Meniscus-climbing behavior and its minimum free-energy mechanism.

Some insects can climb up the top of the meniscus surface generated by a hydrophilic wall by fixing their posture without moving their appendages [Baudoin, R. Bull. Biol. Fr. Belg. 1955, 89, 16. Hu, D. L.; Bush, J. W. M. Nature 2005, 437, 733]. To better understand this interesting phenomenon, we did meniscus-climbing experiments of bent copper sheets. It was found that the sheets do not always climb up the top of the meniscus surface but may stop and stably stay at various positions on the meniscus surface, depending upon their curvatures and masses, and that bent copper sheets can self-assemble into an oriented array (or an anisotropic form) through self-rotating on the water surface. The minimum energy mechanism of meniscus-climbing and self-rotating was then numerically studied. It was further shown that the meniscus-climbing and the rotating behavior is not only a general phenomenon for floating objects with hydrophilic surfaces, even those with fairly large sizes and weights (e.g., a metal bottle cap), but is also conditionally realizable for floating objects with hydrophobic surfaces.

Effects of hydraulic pressure on the stability and transition of wetting modes of superhydrophobic surfaces.

The underlying mechanisms of stability, metastability, or instability of the Cassie-Baxter and Wenzel wetting modes and their transitions on superhydrophobic surfaces decorated with periodic micropillars are quantitatively studied in this article. Hydraulic pressure, which may be generated by the water-air interfacial tension of water droplets or external factors such as raining impact, is shown to be a key to understanding these mechanisms. A detailed transition process driven by increasing hydraulic pressure is numerically simulated. The maximum sustainable or critical pressure of the Cassie-Baxter wetting state on a pillarlike microstructural surface is formulated for the first time in a simple, unified, and precise form. This analytic result reveals the fact that reducing the microstructural scales (e.g., the pillars' diameters and spacing) is probably the most efficient measure needed to enlarge the critical pressure significantly. We also introduce a dimensionless parameter, the pillar slenderness ratio, to characterize the stability of either the Cassie-Baxter or the Wenzel wetting state and show that the energy barrier for transitioning from the Cassie-Baxter to the Wenzel wetting mode is proportional to both the slenderness ratio and the area fraction. Thus, the Cassie-Baxter wetting mode may collapse under a hydraulic pressure lower than the critical one if the slenderness ratio is improperly small. This quantitative study explains fairly well some experimental observations of contact angles that can be modeled by neither Wenzel nor Cassie-Baxter contact angles and eventually leads to our proposals for a mixed (or coexisting) wetting mode.

Effects of ascorbic acid and sodium selenite on growth and redifferentiation in human hepatoma cells and its mechanisms.

After being treated with ascorbic acid (AA) 3 mM + sodium selenite (SS) 1.5 microM, the growth rate and mitotic index of human hepatoma cells BEL-7402 decreased remarkably. The indexes related to cell malignancy were improved, such as cell surface charge obviously decreased, the electrophoresis rate fell from 1.76 microns.s-1.V-1.cm-1 to 0.93, the average of alpha-fetoprotein (alpha-FP) content decreased from 341 micrograms.g-1 protein to 92, and gamma-glutamyl-transpeptidase (gamma-GT) activity from 0.76 U.g-1 protein to 0.19. The indexes related to cell differentiation were affected favourably, such as the level of tyrosine-alpha-ketoglutarate transaminase (TAT) activity increased from 14.2 mumol.g-1 protein to 49.0, and the colonogenic potential decreased 95.3%. These results indicated that hepatoma cells had been successfully induced to redifferentiation by AA + SS. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were significantly higher, while the activity of catalase (CAT) was slower in the treated group than in the control group. The malondialdehyde (MDA) content decreased slightly, reduced glutathione (GSH) decreased sharply, and H2O2 content increased dramatically. In conclusion, these results indicate that the combination of ascorbic acid and sodium selenite may induce the redifferentiation of hepatoma cells and inhibit cell growth by virtue of enhancing the activities of antioxidative enzymes and reducing the formation of H2O2, and altering the cell redox status. The combination of ascorbic acid and sodium selenite may be a potent anticancer treatment option for human hepatoma cells.

Ascorbic acid induces redifferentiation and growth inhibition in human hepatoma cells by increasing endogenous hydrogen peroxide.

The mechanisms of redifferentiation and growth inhibition induced in human hepatoma cells by ascorbic acid (AA) were studied. After treatment with AA, the content of hydrogen peroxide (H2O2) and the activity of superoxide dismutase (SOD) increased in a concentration- and time-dependent manner, while the activity of catalase (CAT) decreased in a concentration- and time-dependent manner. Using 6 mM AA as a positive control, after treatment by 50 microM hydrogen peroxide, the malignant characteristics of human hepatoma cells were alleviated; for example as cell surface charge markedly decreased, the electrophoresis rate dropped from 1.68 microns.s-1.V-1.cm-1 to 0.97, the average of alpha-fetoprotein content decreased from 327 micrograms.g-1 protein to 193, and gamma-glutamyl-transpeptidase activity fell from 0.84 U.g-1 protein to 0.30. The indexes related to cell differentiation were promoted, such as tyrosine-alpha-ketoglutarate transaminase activity increased from 17.1 mumol.g-1 protein to 33.1, and the colonogenic potential decreased by 79.3%. SOD and 3-amino-1,2,4-triazole (AT) exhibited some effects, but there were statistically significant differences between the SOD, AT and H2O2 or AA groups. AA induced growth inhibition and redifferentiation of human hepatoma cells through the production of hydrogen peroxide, since addition of SOD (200 units/ml), an enzyme that dismutates superoxide and generates hydrogen peroxide, and AT (1.5 mM), a CAT inhibitor that inhibits the activity of CAT and leads to an increase in H2O2 content, showed some inducing changes emphasizing the involvement of reactive oxygen species (ROS) in redifferentiation of hepatoma cells. AA can cause the content of H2O2 to increase, and the factor H2O2 showed a similar effect to AA on growth and redifferentiation suggests that H2O2 is involved in hepatoma cell redifferentiation. In conclusion, these results suggest that AA inhibits tumor growth and induces tumor redifferentiation by virtue of producing H2O2.

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.

Analysis of drug interactions in combined drug therapy by reflection method.

AIM: To set up a new method to analyze multidrug interaction in combined drug therapy. METHODS: Based on a dose-effect curve of the combined drugs and the equieffective test, a new mathematical model was set as Q = (Eo - Et)/L (-1 < Q < 1 addition, Q < or = 1 antagonism, Q > or = 1 synergism) where Eo = an observed value (or its fitted value) of combined effect, Et = an expected value of combined effect, and L = an equieffective cutoff between Eo and Et, decided by the equieffective criterion of a special field, the number of data points, and the experimental error. The different types of experimental data were analyzed by the new model. RESULTS: This reflection method could deal with data in combined drug therapy, unnecessary to distinguish between independent and similar action, or exclusive and non-exclusive case among drugs. The number of drugs for combination did not need to be limited. But the experimental data should be enough to fit a dose-effect curve of drugs in combination. If every dose-effect curve of drugs for combination was made, a series of Q values was obtained from all levels of dose-effect for a systematic analysis. To large animal or human experiment, the points of dose-effect of each drug used alone could be reduced to even 1 point. The results of analysis took the criterion of a special field and laboratory error into account in this method. CONCLUSION: The reflection method is an effective method for analysis of multidrug interaction in combined drug therapy.

The unvalidity of Kohlrausch' regulating function for Svensson's isoelectric focusing and stationary electrolysis at steady state.

Kohlrausch' regulating function is of important significance in the field of electrophoresis. In this paper, the relative regulating function is defined from Kohlrausch' regulating function. The relative values, including the limited values, of the regulating function for the stationary electrolysis of salt, on which the classic isoelectric focusing (IEF) is based, are computed and compared with the computer program of the QBASIC written by us. The results directly demonstrate that, (1) in a few cases the regulating function is valid for the stationary electrolysis and IEF, whereas (2) the function is, in most of cases, not valid for the stationary electrolysis and IEF at steady-state. Those findings may be useful for the studies on the relationships between Kohlrausch' regulating function and IEF and for the classification of numerous electrophoretic techniques.

Quantitative design of drug compatibility by weighted modification method.

AIM: To set up a new method for designing and quantitatively analyzing drug compatibility. METHODS: Drugs for compatibility were divided into 6 dose levels which were evenly distributed to 6 compound groups according to a fixed design. A new mathematical model was set up to fit the dose-effect data of 6 groups. The coefficients, obtained from the model, reflected the dose-effect relationship and the important degree of every drug in combination. According to the coefficients, the drugs in compatibility could be distinguished into principal drug, synergist, inferior, antagonist, and assistant. Because compatibility in the maximal effect group was nearly (or was) an optimal one in 6 groups, the doses in the group were taken as a base for further modification which considered interaction among drugs. The results of the modification were demonstrated by further experiment. This method was applied to design and to quantitatively analyze the compatibility of allantoin, metronidazole, and dexamethasone sodium phosphate by 2 effect indices in mice. RESULTS: This new method was able to effectively determine important degree of drugs in combination, and to optimize their doses for designing compatibility. CONCLUSION: This weighted modification method is a highly efficient, accurate, and practical means for designing and quantitatively analyzing drug compatibility.

Analysis of multidrug effects by parameter method.

AIM: To set up a new analytic method for multidrug effects. METHODS: Based on the principles of the target site kinetics and the equieffective test, a new mathematical model was set as Q = (Eo-Ee)/magnitude of Ee x W-sx x T (-1 < Q < 1 addition, Q < or = -1 antagonism, Q > or = 1 synergism) where Eo = a fitted value of the observed effect of a combination, Ee = an expected value of combined effect, W = an equieffective criterion decided by a special field, sx = a common standard error of Eo and Ee, and T = a value of one-sided t0.05. All the calculations were completed with computer. Dose-effect data from different types of experiments were fitted by the new model and the results were compared with those of other methods. RESULTS: This parameter method dealt with different types of data well fitted with the Hill equation, and was not limited to analyze receptor interaction of drugs, or the number of combined drugs. A series of Q values was obtained from all levels of dose-effect for a systematic analysis. The analysis took the criterion of a special field and laboratory error into account. CONCLUSION: This parameter method can effectively analyze the multidrug effects.