Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Comput Chem ; 44(31): 2391-2403, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37658482

RESUMO

Total and orbital electron densities of molecules are explored for the effect of the long-range correction (LC) for density functional theory (DFT) exchange functionals by comparing to the effect of the ab initio coupled cluster singles and doubles (CCSD) method. Calculating the LC effect on the total electron densities shows that the LC stabilizes the electrons around the long-range interaction regions of kinetic energy density, which are assumed to be electrons other than free electrons and self-interacting electrons, while the CCSD method stabilizes the electrons in the long-range interaction regions in the vertical molecular planes. As a more precise test, the LC effect on orbital densities are compared to the CCSD effect on Dyson orbital densities. Surprisingly, these effects are similar for the unoccupied orbitals, indicating that the LC covers the effects required to reproduce the CCSD Dyson unoccupied orbitals. For exploring the discrepancies between these effects on the occupied orbitals, the photoionization cross sections are calculated as a direct test for the shapes of the HOMOs to investigate the differences between these effects on the occupied orbitals. Consequently, the LC clearly produces the canonical HOMOs close to the CCSD Dyson and experimental ones, except for the HOMO of benzene molecule that mixes with the HOMO - 1 for the CCSD Dyson orbitals. This indicates that the orbital analyses using the photoionization cross sections are available as a direct test for the quality of DFT functionals.

2.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1004157

RESUMO

【Objective】 To provide reference for formulating relatively unified quality control strategies and meeting the requirements of homogenization construction of blood banks across Chongqing area by retrospectively analyzing sampling results of different blood components during the past two years in all levels of blood banks in Chongqing area. 【Methods】 The key quality data of blood components prepared by 6 blood banks in Chongqing were analyzed retrospectively. According to the issuing units to the clinical during the past two years, the research objects were selected as leukocyte-depleted suspended RBCs, cryoprecipitate, pathogen inactivated fresh frozen plasma(FFP) and apheresis platelets. The quality data of the above-mentioned blood components from January 2019 to June 2021 were collected and analyzed. 【Results】 For leukocyte-depleted suspended RBCs(1U)prepared by 5 blood banks, statistically significant differences in Hb, residual white blood cells and hemolysis rate at the end of storage, except for Hct, were noticed(P<0.05). For cryoprecipitate, the content of blood coagulation factor Ⅷ and fibrinogen were statistically different among 3 blood banks in 1U specification(P<0.05) and among 5 blood banks in 2U specification(P<0.05). For pathogen inactivated FFP, the content of blood coagulation factor Ⅷ, plasma proteins, and residual methylene blue were statistically different among 3 blood banks(P<0.05). For apheresis platelets, Plt, white/red blood cells contamination and pH at the end of storage were statistically different among 3 blood banks(P<0.05). 【Conclusion】 The quality data of blood components, prepared by different blood banks, meet the requirements of national standard, however, certain differences are existing among blood banks.Key points during the process of collection, preparation, storage and transportation need to be cleared and unified, so as to reduce the differences between each other, and determine the direction and basis for homogeneity construction in the next step.

3.
Biocontrol Sci ; 26(1): 43-47, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33716248

RESUMO

In these days, all agar media used for both pharmaceutical and industrial territories were required to meet performance criteria. There were recovery rates of assigned microorganisms as performance criteria in both pharmacopeia and ISO standards. However, in spreading plate method, there is no concrete spreading time even though it is shown only "as quickly as possible" in ISO standards. In this study, we verified the impact of spreading time in spreading plate method for the quality control of SCD (Soybean Casein Digest) agar plate. When 30s, 60s, and 120s of spreading time were compared using Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 6538, Candida albicans ATCC 10231, and Aspergillus brasiliensis ATCC 16404, respectively, there is no significant difference in recovery rates of all strains tested between 30s and 60s. However, recovery rates of E. coli and P. aeruginosa were decreased in 120s of spreading time. Our results demonstrated that spreading using plastic rod would be better to complete within 60s in spreading plate method since long spreading time had the impact to recovery rate of certain bacteria.


Assuntos
Escherichia coli , Preparações Farmacêuticas , Ágar , Aspergillus , Bacillus subtilis , Candida albicans , Testes de Sensibilidade Microbiana
4.
Pediatr Pulmonol ; 55(8): 1955-1962, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32460445

RESUMO

OBJECTIVE: Despite technical specifications of neonatal mechanical ventilators (MVs) guarantee clinically irrelevant discrepancies between the set and the delivered values of ventilation parameters, previous studies reported large deviations. Most studies characterized performances of a given model/brand by studying a single device, disregarding possible intramodel differences, and leaving the accuracy of the ventilation parameters effectively delivered in clinical settings unknown. The aim of this study was to evaluate the real-life accuracy of pressure and volume parameters delivered by neonatal ventilators ready to be used on patients in neonatal intensive care units (NICUs). STUDY DESIGN: In vitro study. SUBJECTS SELECTION: Neonatal ventilators (n = 33 of 8 different models) available in four European NICUs. METHODOLOGY: The MVs were connected to a test lung (resistance = 50 cmH2 O*s/L, compliance = 0.35 mL/cmH2 O) provided with pressure and flow sensors. MVs were tested over two different ventilation modes randomly: (a) pressure controlled (PC) with a peak inspiratory pressure (PIP) of 22 cmH2 O, and (b) PC with volume targeted ventilation (VTV) with a tidal volume (VT ) of 6 mL. In all tests, positive end-expiratory pressure (PEEP) was set to 6 cmH2 O, respiratory rate to 45 breaths/min, inspiratory time to 0.33 seconds, and oxygen fraction to 0.3. RESULTS: During PC the median (min-max) values delivered were: PEEP = 5.84(4.95-6.48) cmH2 O, PIP = 21.63(20.04-22.62) cmH2 O. During VTV, VT was 5.94(4.63-8.01) mL. VT was considerably variable, ranging from -22% to +33% of the set and displayed values. Differences in accuracy among devices of the same model were comparable to those found among different models. CONCLUSIONS: Our findings suggest that loss of accuracy in ventilation variables is likely related to daily use of the devices rather than weakness in the design or manufacturing process, urging the improvement of maintenance and quality control procedures to preserve the performances of neonatal MVs during their entire lifespan.


Assuntos
Ventiladores Mecânicos/normas , Humanos , Unidades de Terapia Intensiva Neonatal , Pulmão/fisiologia , Respiração com Pressão Positiva , Controle de Qualidade , Respiração , Volume de Ventilação Pulmonar
5.
Waste Manag ; 103: 240-250, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901617

RESUMO

Management of solid recovered fuel (SRF) in South Korea is unique from most other countries in that it is based on a single standard. All SRFs are distributed at the same price irrespective of their performance, resulting in utilization problems and a low degree of acceptance among consumers. Moreover, the difficulty of temperature maintenance during transportation, excessive ash content, and the use of inappropriate microwave acid digestion methods pose challenges to SRF reliability. To address these issues, we compared the relevant management statuses in South Korea with those of the international community and reviewed the effects of the transportation temperature, ash content, and microwave acid digestion technique. The moisture, ash, sulfur, and chlorine contents as well as the lower heating values (LHVs) of all the samples from South Korea were found to be below the standard [international] thresholds, and they were barely influenced by the transportation temperature. In addition, 5 g samples were found to be more appropriate for ash content analysis than the 20 g samples used in South Korea, with the former producing smaller standard deviations. The optimal microwave acid digestion conditions were also determined to be a reaction time with nitric acid of >10 min, temperature of 180 °C, and microwave power of 600 W. The results of this study highlight the need for revising the SRF test methods used in South Korea, to boost the market and enhance quality reliability.


Assuntos
Eliminação de Resíduos , Cloro , Calefação , Reprodutibilidade dos Testes , República da Coreia
6.
J Biophotonics ; 13(3): e201960112, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31793214

RESUMO

Spectral quality control is an important step in the analysis of infrared spectral data, however, often neglected in scientific literature. A frequently used quality test that was originally developed for infrared spectra of bacteria is provided by OPUS software from Bruker Optik GmbH. In this study, the OPUS quality test is applied to a large number of spectra of bacteria, yeasts and moulds and hyperspectral images of microorganisms. It is shown that the use of strict thresholds for parameters of the OPUS quality test leads to discarding too many spectra. A strategy for optimizing parameters thresholds of the OPUS quality test is provided and a novel approach for spectral quality testing based on extended multiplicative signal correction (EMSC) is suggested. For all the data sets considered in our study, the EMSC quality test is shown to be the best among different alternatives of OPUS quality test provided.


Assuntos
Algoritmos , Luz , Diagnóstico por Imagem , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Appl Spectrosc ; 73(1): 47-58, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30063385

RESUMO

Theoretical probability distributions are often fitted to the individual peaks of Raman spectra to decompose them and facilitate further analyses. Fitting has the additional advantage of eliminating noise. We have exploited this noise-eliminating attribute of fitting procedures in an automated algorithm to smooth Raman spectra. An initial smoothing was performed by fitting Voigt distributions to every channel in a spectrum. The Voigt distribution characters used were strongly Gaussian, the distribution widths equal to the spectral resolution, and their initial amplitudes equal to the spectral intensities at the channels where they were located. The smoothed spectrum was then subtracted from the original noisy spectrum to obtain a residual. For channels where the residual exceeded a limit-of-detection threshold, the distribution width was decreased. The fitting was then repeated until a secondary, lower limit distribution width was reached. The residual was then smoothed repeatedly in the same manner until the minimum distribution width was reached. After each repetition, the smoothed residual was added to the smoothed spectrum. The process was continued until a combined limit of detection and chi-squared stopping criterion was reached. Although slower in comparison to spline- and Savitzky-Golay-based methods, the smoothing quality was significantly better allowing the majority of smoothed spectra, in contrast to these methods, to pass a stringent smoothing quality test.

8.
J Photochem Photobiol B ; 187: 126-130, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30145462

RESUMO

The evaluation of optical properties of biological samples is gaining increasing interests both in scientific and commercial fields concerning agriculture and food processing. The optical techniques can indeed be able to provide information on quality assessment in a fast and non-destructive way. This feature makes them suitable for automatic management of control processes. In this paper, we propose to use the Delayed Luminescence, a ultra-weak and photo-induced emission of optical photons, as a tool for a rapid evaluation of germination performance, the principal index reflecting seed quality. Two lots of 'Mirella' F1 watermelon dried seeds, of 96 seeds each, were considered. The seeds were analyzed in the conditions as provided by seed/breeding company. Characteristics of Delayed Luminescence emission from each single seed were correlated to the different germination levels as assessed by International Seed Testing Procedures. Parametric differences in the two lots were determined, based on the relaxation kinetics of some spectral components. A control test, with the aim to construct a calibration model, was conceived and successfully tested. Time decays of Delayed Luminescence spectral components at central wavelengths 450 nm, 550 nm and 650 nm, corresponding to spectrum region where natural biomarkers as NADH, flavins and lipopigments, protoporphyrin and ROS respectively emit, have been evaluated. The results show that such time decays are strictly connected to the biological state of the system under analysis and allow also proposing Delayed Luminescence measurement as a quick, cheap and non-destructive test for seed viability analysis.


Assuntos
Citrullus/química , Medições Luminescentes , Citrullus/crescimento & desenvolvimento , Flavinas/química , Flavinas/metabolismo , Germinação/fisiologia , Lipídeos/química , NAD/química , NAD/metabolismo , Protoporfirinas/química , Protoporfirinas/metabolismo , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento
9.
Zhongguo Zhong Yao Za Zhi ; 41(11): 2044-2048, 2016 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-28901099

RESUMO

In order to provide a basis for establishing seed testing rules and seed quality standard of Bletilla striata, the seed quality of B.striata from different producing area was measured referring to the Rules for Agricultural Seed Testing(GB/T 3543-1995).The results showed that the seeds of B.striata passed through 20-mesh sieve for purity analysis.The weight of seeds was measured by 1000-seed method and the water content was measured at the higher temperature (133±2) ℃ for 3 hours.The seeds were cultured on the wet filter paper at 30 ℃ for 4-20 days in light for germination testing.The method of testing seed viability was that seeds were dipped into 1% TTC solution for 7 hours at temperature of 40 ℃.


Assuntos
Germinação , Orchidaceae , Controle de Qualidade , Sementes , Temperatura
10.
Zhongguo Zhong Yao Za Zhi ; 41(8): 1439-1445, 2016 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-28884536

RESUMO

Referring to the rules for agricultural seed testing (GB/T 3543-1995) issued by China, the test of sampling, purity, thousand seed weight, moisture, viability, relative conductivity and germination rate had been studied for seed quality test methods of Lonicera macranthoides. The seed quality from 38 different collection areas was measured to establish quality classification standard by K-means clustering. The results showed that at least 7.5 g seeds should be sampled, and passed 20-mesh sieve for purity analysis.The 500-seed method used to measure thousand seed weight. The moisture was determined by crushed seeds dried in high temperature (130±2) ℃ for 3 h.The viability determined by 25 ℃ 0.1% TTC stained 5h in dark. 1.0 g seeds soaked in 50 ml ultra pure water in 25 ℃ for 12 hours to determine the relative conductivity. The seed by 4 ℃stratification for 80 days were cultured on paper at 15 ℃. Quality of the seeds from different areas was divided into three grades. The primary seed quality classification standard was established.The I grade and II grade were recommend use in production.


Assuntos
Germinação , Lonicera , Controle de Qualidade , Sementes/crescimento & desenvolvimento , China
11.
Chinese Journal of Immunology ; (12): 1793-1796, 2016.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-506629

RESUMO

Objective:In order to look for a good method for preparation of hemorrhagin antiserum. Methods: Three kinds of hemorrhagins including AaH Ⅰ, AaH Ⅱ, and AaH Ⅳ were purified from Agkistrodon acutus venom according to predecessors's methods and crude AaH Ⅰ, AaH Ⅱ and AaH Ⅳ were obtained. Preparation electrophoresis was used to purify AaH Ⅰ,AaH Ⅱand AaH Ⅳ further. As for an hemorrhagin, six different dyeing methods were used to dye PAGE gel and the gel contained hemorrhagin was obtained respectively. The ground gel contained hemorrhagin was used to immune mice and its antiserum was obtained. Antiserums quality was tested through ELISA test and neutralization of the hemorrhagic activities of corresponding hemorrhagin. Results:Effective IgG concentration in different antiserum was different and effective IgG made through non toxic type protein fast stain reagent kit was higher than others. Conclusion:Non toxic type protein fast stain reagent kit is the best dyeing method among the six dyeing methods.

12.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-496842

RESUMO

Objective To study the quality testing of dose delivery system of the active spot scanning proton and heavy ion accelerator,in order to provide the reference for the quality control of related equipment.Methods In the four therapy rooms,both 0.6 cc chambers and Gafchromic EBT3 films were used,respectively,to test the accelerator for dose reproducibility,dose linearity,dose stability,depth dose distribution,beam scanning position deviation and radiation field uniformity in each therapy room.Results Dose reproducibility variation coefficients are all less than 1.5%,dose linearity's maximum deviations less than 2%,dose stability's deviations less than 2%,depth dose distribution stability within 2%,beam scanning position deviation less than 1 mm,consistency of irradiation field's deviation less than 2 mm,and flatness within ± 5%.Conclusions The indicators about quality testing for the active spot scanning proton and heavy ion accelerator are all in line with the requirements of IEC standards draft.

13.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-236072

RESUMO

In order to provide a basis for establishing seed testing rules and seed quality standard of Bletilla striata, the seed quality of B.striata from different producing area was measured referring to the Rules for Agricultural Seed Testing(GB/T 3543-1995).The results showed that the seeds of B.striata passed through 20-mesh sieve for purity analysis.The weight of seeds was measured by 1000-seed method and the water content was measured at the higher temperature (133±2) ℃ for 3 hours.The seeds were cultured on the wet filter paper at 30 ℃ for 4-20 days in light for germination testing.The method of testing seed viability was that seeds were dipped into 1% TTC solution for 7 hours at temperature of 40 ℃.

14.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-853138

RESUMO

Objective: To optimize the testing methods for seed quality of Marsdenia tenacissima, and provide basis for establishing seed quality standard of M. tenacissima. Methods: The seed quality of M. tenacissima from different producing areas was measured based on the International Seed Testing Protocol made up by ISTA and Rules for Agricultural Seed Testing issued by China. Results: The samples weight of M. tenacissima were at least 900 g for purity analysis and were at least 90 g for testing. The 1 000-seed weight was determined by 500-seed method, and the water content was carried out by higher temperature (133 ± 2)℃ for 6 h. After soaking in water for 24 h, M. tenacissima seeds were cultured in wet sand at 30℃ for 1-8 d under illumination for germination testing. Seed viability was tested by TTC method in 35℃ for 3 h. Conclusion: The seed testing methods for quality items of M. tenacissima have been initially established.

15.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-320840

RESUMO

Referring to the rules for agricultural seed testing (GB/T 3543-1995) issued by China, the test of sampling, purity, thousand seed weight, moisture, viability, relative conductivity and germination rate had been studied for seed quality test methods of Lonicera macranthoides. The seed quality from 38 different collection areas was measured to establish quality classification standard by K-means clustering. The results showed that at least 7.5 g seeds should be sampled, and passed 20-mesh sieve for purity analysis.The 500-seed method used to measure thousand seed weight. The moisture was determined by crushed seeds dried in high temperature (130±2) ℃ for 3 h.The viability determined by 25 ℃ 0.1% TTC stained 5h in dark. 1.0 g seeds soaked in 50 ml ultra pure water in 25 ℃ for 12 hours to determine the relative conductivity. The seed by 4 ℃stratification for 80 days were cultured on paper at 15 ℃. Quality of the seeds from different areas was divided into three grades. The primary seed quality classification standard was established.The I grade and II grade were recommend use in production.

16.
China Pharmacy ; (12): 995-997,998, 2016.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-605646

RESUMO

OBJECTIVE:To select the optimum conditions for germination test of Sophora alopecuroides seed,and to provide reference for formulating seed test rule and standardization of S. alopecuroides. METHODS:S. alopecuroides seeds were soaked in 98% H2SO4 for 30 min and 35 ℃ warm water for 29 h,and then treated under different temperature conditions (15 ℃,20 ℃, 25℃and 30℃),different germination beds(on paper,between paper,on sand,in sand)and different light conditions(2 000 lx lighting 16 h,dark). Optimal germination condition was screened by using germination rate,germinative potential and germinative index as indicators. S. alopecuroides seeds were cultured under this condition for 7 days,and then germination rate was determined. RESULTS:Different temperatures had no significant effect on germination rate,but influenced germinative potential and germina-tive index;those indicators reached maximal value at 20 ℃. Different germination beds affected each indicator,and under condi-tion of on sand,those indicators were the highest. Light treatment had no significant effect on germination indicators. Under suit-able condition,the seed sprouted since first day of germination bed treatment;germination rate was more than 90% on second day,and reached maximal value on fifth day and didn’t increase any longer. CONCLUSIONS:The suitable condition of seed ger-mination was soaking in 98% H2SO4 30 min+35 ℃ warm water for 29 h,on sand under light at 20 ℃. Initial count on second day of germination bed treatment and final count on forth day were analyzed statistically as well as germination rate. This method can be used as standard quality test of the seed of S. alopecuroides.

17.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-960665

RESUMO

@#ObjectiveTo study the method of testing abrasion resistance of axillary crutch tips. MethodsA test method based on pressure analysis in normal use of axillary crutches was suggested, which characterized: put 450 N on axis of the tip; the tip or text surface sway 60° for 500000 times in frequency of 40 /min; maximal abrasion thickness after test should be less than 3.3 mm. Experimental facilities were established to carry out fatigue test of wearability. ResultsThe test method suggested can reflect tips abrasion in real context. ConclusionThe text method can be used for tips abrasion and fatigue resistance adjustment.

18.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-593132

RESUMO

Quality control of medical equipment is very important to the diagnostic accuracy and the cure effect. The work of the quality control is the main technical basis of the hospital construction in promoting medical development, and it's also an important content of the modem medical management. The status, causes and countermeasures of medical equipment quality control in military hospital at the present time are analyzed and discussed.

19.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-537663

RESUMO

Objective To analyses the key specifications in test and evaluation regulations in accordance with the results of 68 cases CT quality tests.Methods Using CT performance phantom,dose phantom and X-ray dose survey meter to test all specifications of CT performance that were demanded by the state regulations.Results The application quality of CT scanner was promoted by tests.CT situation in Gansu province was good for 91.2% acceptance rate.Conclusion The way to promote CT performance is to strengthen quality control and to insist on acceptance test process.

20.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-583785

RESUMO

Objective To provide reference for CT performance/quality test. Methods Researches were made in Chinese documentations on CT performance/quality test issued from 1998-aug 2002.Results Approximately a quarter of CTs among the documents assembly released public were tested unqualified . Qualification rate of new CTs was higher Than second-handed ones. Part of items and data in the documentations were insufficient. Conclusion CT performance/quality test is a crucial part of system Engineering of QC(quality control),therefore it must be implemented seriously and relevant regulations should be optimized in order to benefit both patients and health-care communities.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...