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1.
Zhonghua Yan Ke Za Zhi ; 60(2): 193-199, 2024 Feb 11.
Artigo em Chinês | MEDLINE | ID: mdl-38296326

RESUMO

Myopia is a global public health issue, particularly prevalent in China, with a rising trend in recent years. The increased use of computers, smartphones, and video display terminals has led to frequent dry eye symptoms, such as blinking, among myopic students. Studies have revealed a higher incidence of dry eye in myopic children compared to emmetropic children, significantly impacting their learning and quality of life. However, ophthalmologists have traditionally focused more on the prevention and control of myopia, often neglecting ocular surface health awareness in children. It is essential to understand the potential impact of myopia on dry eyes in children and whether there is a difference in dry eye prevalence. This article reviews the current state of research on childhood myopia-related dry eye, encompassing epidemiology, pathogenesis, and risk factors, aiming to provide clinical reference for intervention, prevention, and precise treatment of dry eyes in myopic children.


Assuntos
Síndromes do Olho Seco , Miopia , Criança , Humanos , Qualidade de Vida , Olho/patologia , Miopia/diagnóstico , Emetropia , Refração Ocular
2.
Zhonghua Wai Ke Za Zhi ; 61(10): 839-844, 2023 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-37653985

RESUMO

The incidence of pancreatic neuroendocrine neoplasm(pNEN) increased over the past two decades. Liver metastasis, the most common type of distal metastasis, is also one of the most important prognostic factors. Although several medical treatments, including biotherapy, chemotherapy, targeted therapy, peptide receptor radionuclide therapy and locoregional therapy, are available for pNEN with liver metastases, surgery is still the only possible treatment for cure. Currently, there are several controversies as regards surgical treatment for pNEN with liver metastases. These controversies include, but are not limited to, whether surgical resection is appropriate for pancreatic neuroendocrine tumor G3 with liver metastases, how to classify primary lesion and hepatic metastases comprehensively and accurately, what is the optimal surgical strategy for type Ⅱ liver metastases, who can benefit greatly from cytoreduction, and how to refine the Milan criteria for liver transplantation. This article aims to discuss those main controversies and provide prospects for future clinical trials.

4.
Artigo em Chinês | MEDLINE | ID: mdl-34344095

RESUMO

Objective: To investigate the frequency characteristics and the pathological characteristics of the horizontal crista ampullaris in patients with Meniere's disease,and to analyse its structural basis. Methods: Between March, 2019 and November, 2019, seventy-two patients diagnosed as Meniere's disease (27 males and 45 females, aged from 13 to 74 years, with a course of disease ranging from 4 months to 32 years)in Shandong Provincial ENT Hospital were included.Caloric test, sinusoidal harmonic acceleration test (SHA), video-head impulse test (v-HIT), Gadolinium-enhanced inner-ear 3D-FLAIR MRI and pure tone audiometry were conducted in the patients. The function of the horizontal semicircular canal in these patients were analysed as well as its relationship with the degree of endolymphatic hydrops,clinical stage and duration. Light microscopy and transmission electron microscopy were used to observe the ultrastructure of horizontal semicircular canal crista ampullaris from six patients with refractory Meniere's disease who underwent labyrinthectomy. The number of type Ⅰ and type Ⅱ vestibular hair cells, the common pathophysiological changes of horizontal semicircular canal crista ampullaris were investigated in these patients. Statistical analysis was performed using SPSS 19.0. Results: With the increase of detection frequency, the abnormal rate decreased gradually. The abnormal rate of caloric test was 69.4% (50/72), SHA 51.4% (37/72), V-HIT 36.1% (26/72), comparation of the positive rate among the three tests showed statistically significant differences(P<0.05).Neither caloric test nor SHA had correlation with the degree of hydrops(P>0.05), but v-HIT(r=0.434,P<0.01).There was correlation with clinical stage to SHA and v-HIT(r=0.338,0.462,P<0.01), except caloric test(P>0.05).No significant relation was found with caloric test, SHA, v-HIT and course of disease(P>0.05).Morphological observation found abnormal monolayer epithelialization of the horizontal semicircular canal crista ampullaris significantly decreased number of type Ⅱ hair cells compared with type Ⅰhair cells. Hair cells showed perinuclear vacuolization, cytoplasmic vacuoles, mitochondrial electron density increasement and loss of stereocilia. Conclusions: The horizontal semicircular canal damage in the patients with Meniere's disease has a frequency-dependent characteristic, mainly occurres in low frequency area. With progress of the disease, the high frequency area of ampulla will be impaired gradually, and it is related to the degree of endolymphatic hydrops and hearing level. Hair cell injury would be observed,the frequency characteristics may be more associated with the disorder of type Ⅱ hair cells.


Assuntos
Hidropisia Endolinfática , Doença de Meniere , Testes Calóricos , Feminino , Humanos , Masculino , Canais Semicirculares , Ductos Semicirculares
5.
Bioact Mater ; 5(3): 564-568, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32373762

RESUMO

In this paper, biomedical porous Ti-Nb-Ta-Zr with 40% porosity and 166 ± 21 µm macro-pore size was successfully fabricated by space holder method. The microstructure, Vickers hardness, compressive and electrochemistry behavior were studied. It results that a few second phases exist in ß matrix of the porous Ti-Nb-Ta-Zr. Its Young's modulus is 0.8 GPa, close to 0.01-3 GPa for trabecular bone. The total recovery strain ratio and pseudoelastic strain ratio are 8.8% and 2.7%, respectively. It fails mainly by brittle cleavage with the fan-shaped and smooth cleaved facets. Although, local ductile fracture by a few dimples and a small amount of transcrystalline fracture with the cleavage of similarly oriented laths in a colony are observed on the fracture surface. The impedance spectrum of porous Ti-Nb-Ta-Zr has the characteristics of half capacitive arc resistance, showing good corrosion resistance in SBF solution.

6.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 54(1): 10-16, 2019 Jan 09.
Artigo em Chinês | MEDLINE | ID: mdl-30630253

RESUMO

Objective: To investigate the incidence and proportion of salivary gland tumors in order to provide new thinking for clinical diagnosis and treatment. Methods: Collected 3 724 cases salivary gland tumors diagnosed by Pathology Department of Hospital of Stomatology, Jilin University from January 1961 to December 2016. The pathological diagnosis referred to the fourth edition of head and neck-salivary gland tumor histopathological classification standard of WHO. The database was established with Microsoft Excel and analyzed with SPSS 18.0. Made a retrospective analysis and comparison on the numbers of all cases in terms of types, site, gender and age and estimate the trend with the time interval of 8 years, and then make a judgement of the trend of salivary tumors. Results: The benign tumors were more common than the malignant among all periods, the proportion of all tumors was about 2.92∶1; The top three benign tumors were polymorphous adenoma [73.78% (2 046/2 773)], Warthin tumor [15.80% (438/2 773)] and base cell adenoma [8.37% (232/2 773)]. Polymorphous adenoma took up 54.94% (2 046/3 724) of all tumors. The top three malignant tumors were mucous epidermoid carcinoma [31.44% (299/951)], adenoid cystic carcinoma [26.92% (256/951)] and adenocarcinoma [11.88% (113/951)]. As for sex, male female ratio was 0.83∶1. As for site, the pathogenic site of tumors was mainly in parotid gland [63.75% (2 374/3 724)], followed by palatal gland [16.50% (615/3 724)], then submandibular gland [12.67% (472/3 724)]; As for age, the common age was between 51 and 60 years old [23.74% (884/3 724)], followed by 41 to 50 years old [21.56%(803/3 724)]. Conclusions: The incidence of benign and malignant salivary gland tumor increased in the 56 years. Females showed a higher incidence. The majority tumors occurred in parotid gland. The most common salivary gland tumor was pleomorphic adenoma and the most common malignant tumor was mucous epidermoid carcinoma. The most common age was in 51-60 years old period.


Assuntos
Adenoma Pleomorfo , Neoplasias das Glândulas Salivares , Adenolinfoma/diagnóstico , Adenolinfoma/patologia , Adenoma Pleomorfo/diagnóstico , Adenoma Pleomorfo/patologia , Adulto , Carcinoma Adenoide Cístico/diagnóstico , Carcinoma Adenoide Cístico/patologia , Carcinoma Mucoepidermoide/diagnóstico , Carcinoma Mucoepidermoide/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias das Glândulas Salivares/diagnóstico , Neoplasias das Glândulas Salivares/patologia
7.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 53(7): 480-483, 2018 Jul 09.
Artigo em Chinês | MEDLINE | ID: mdl-29996367

RESUMO

To investigate the incidence of malignant tumors in oral and maxillofacial region and the pathological features of various tumors, a total of 3 382 cases of malignant tumors in oral and maxillofacial region admitted to Jilin University from Januarary 2000 to December 2017. The characteristics of age, sex, location and pathological types of all kinds of tumors were analyzed. The median onset age is 57 years old, 51 to 70 years old is a high-risk age group, the ratio of male to female was 1.9∶1. The primary tumor location is tongue, gingiva and floor of mouth. Epithelial, lymphatic hematopoietic system, bone and soft tissue were the three major sources of tumor tissue, and squamous cell carcinoma was the most common pathological type (65.1%), followed by mucoepidermoid carcinoma and adenoid cystic carcinoma. In summary, oral and maxillofacial malignancies have a high incidence in elderly men, and tongue is the most common site of disease. Epithelial-origin and squamous cell carcinomas are the first of their origins and pathological types, respectively.


Assuntos
Carcinoma Adenoide Cístico/epidemiologia , Carcinoma Mucoepidermoide/epidemiologia , Carcinoma de Células Escamosas/epidemiologia , Neoplasias Bucais/epidemiologia , Adulto , Idoso , Neoplasias Faciais/epidemiologia , Feminino , Gengiva , Humanos , Incidência , Vasos Linfáticos , Masculino , Neoplasias Maxilares/epidemiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Língua/epidemiologia
8.
Nanotechnology ; 27(7): 075605, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26789593

RESUMO

Composite nanostructures consisting of porous NiO nanosheets on carbon nanotubes (CNTs) are fabricated using a facile and low-cost electroless plating method. The CNTs, modified by a polymer, are adopted as the template upon which porous Ni nanosheets are grown using electroless plating. This is followed by removal of the polymer layer and oxidation of the Ni by controlled thermal annealing. The effect of reductant concentration on the morphology of the NiO nanosheets is studied. The electrochemical characteristics of the nanostructures are measured using chronopotentiometry. Experimental measurements show that the NiO nanosheet covered CNT composite nanostructures exhibit a relatively high specific capacitance of 1177 F g(-1) at a discharge current density of 2 A g(-1), while retaining 89.2% of its initial capacitance at a current density of 2 A g(-1) after 1000 cycles.

9.
Phys Chem Chem Phys ; 17(8): 5543-6, 2015 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-25631580

RESUMO

Molecular dynamic simulations are performed for the dynamic spreading of a nanosized water droplet subject to a parallel electric field. The results show that the droplet spreads asymmetrically in a weak field but symmetrically in a strong field. The initial conditions affect the dynamic spreading behavior but not the final equilibrium shapes.

10.
Langmuir ; 30(9): 2394-400, 2014 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-24547747

RESUMO

Molecular dynamics simulations are applied to study the spreading behavior of a nanosized water droplet that contains freely moving Na(+)/Cl(-) ions subject to an imposed electric field parallel to a solid surface. Results show that the positive and negative ions move relatively freely in response to an applied electric field, whereas polar water molecules realign themselves. These localized behaviors of the ions and the polar molecules are affected by both the applied electric field strength and the ion concentration, which in turn determine the deformation and spreading of the droplet on a solid substrate. The presence of the freely moving ions causes the ion-containing droplet to spread differently from a droplet of pure water. In a weak electric field of 0.05 V/Å, a droplet of a lower ion concentration spreads asymmetrically and the spreading asymmetry is considerably smaller than that associated with a pure water droplet of the same size. In a stronger field of 0.1 V/Å, a droplet of a higher ion concentration spreads symmetrically and completely wets the solid surface whereas a less ionically conducting droplet undergoes an asymmetric-to-symmetric transition in spreading until it reaches equilibrium.

11.
Langmuir ; 29(13): 4266-74, 2013 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-23488748

RESUMO

Molecular dynamics (MD) simulations are performed for the spreading of a nanosized water droplet on a solid substrate subject to a parallel electric field. A combined electrostatic and Lennard-Jones potential is employed to represent the intermolecular interactions. Results show that in response to the applied field, polar water molecules realign themselves and this microscopic reorientation of molecular dipoles combines with the intermolecular forces to produce a macroscopic deformation of a free spherical water droplet into an ellipsoid. The applied field has a strong effect on the spreading of the water droplet on a solid substrate. For a weaker parallel field, the droplet spreading is asymmetric with the leading contact angle being greater than the trailing contact angle. With an increase in field strength, this asymmetry continues to increase, culminates, and then decreases until it disappears. The symmetric spreading remains with a further increase in the field strength until the saturation point is reached. This transition from the asymmetric to symmetric spreading is a manifestation of the interaction of the electric field with polar water molecules and the intermolecular forces within the droplet and between the water and solid; the interaction also leads to a change in hydrogen bonds along the droplet surface. The dynamics of the droplet spreading is entailed by the electrically induced motion of molecules along the liquid surface toward the solid substrate and is controlled by a competing mechanism among the electric, water-water, and water-solid intermolecular forces.


Assuntos
Simulação de Dinâmica Molecular , Nanoestruturas/química , Água/química , Campos Eletromagnéticos , Tamanho da Partícula , Propriedades de Superfície
12.
Plant Sci ; 188-189: 36-40, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22525242

RESUMO

The cytoplasmic male sterility (CMS) line FuCMS5A and its restorer line FuHui9 were crossed to produce a segregating F(2) population for pollen fertility assay and the genetic mapping of restorer-of-fertility (Rf) gene. Results showed that the individual F(2) plants were fertile or semi-fertile based on their pollen fertility characteristics. The average ratios of viable pollen were 96.90% and 50.00% for each class of individuals. The segregation of F(2) plants showed a good fit to a 1:1 ratio, which reflects a typical heredity pattern of gametophytic CMS with fertility restorer being controlled by a single dominant gene. Using bulk segregation analysis (BSA) and genetic mapping, the Rf gene was mapped on molecular linkage group J (chromosome 16), between the simple sequence repeat (SSR) makers BARCSOYSSR-16-1064 and BARCSOYSSR-16-1082 with the distances of 0.59 and 0.83 cM, respectively. Four SSR markers (BARCSOYSSR-16-1070, Sctt011, BARCSOYSSR-16-1076 and BARCSOYSSR-16-1077) were cosegregating with this Rf gene in the mapping population. These makers will greatly facilitate the maker assisted selection procedures in CMS breeding programs and it lays a foundation for further map-base cloning of the Rf gene.


Assuntos
Citoplasma/genética , Genes de Plantas/genética , Glycine max/genética , Infertilidade das Plantas/genética , Cruzamento , Mapeamento Cromossômico , Citoplasma/fisiologia , Flores/genética , Flores/fisiologia , Ligação Genética , Marcadores Genéticos/genética , Repetições de Microssatélites , Pólen/genética , Pólen/fisiologia , Glycine max/fisiologia
13.
Br J Radiol ; 84(997): 58-63, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20858665

RESUMO

OBJECTIVE: The preferential use of intensity-modulated radiotherapy (IMRT) over conventional radiotherapy (CRT) in the treatment of head and neck cancer has raised concerns regarding dose to non-target tissue. The purpose of this study was to compare dose-volume characteristics with the brachial plexus between treatment plans generated by IMRT and CRT using several common treatment scenarios. METHOD: The brachial plexus was delineated on radiation treatment planning CT scans from 10 patients undergoing IMRT for locally advanced head and neck cancer using a Radiation Therapy Oncology Group-endorsed atlas. No brachial plexus constraint was used. For each patient, a conventional three-field shrinking-field plan was generated and the dose-volume histogram (DVH) for the brachial plexus was compared with that of the IMRT plan. RESULTS: The mean irradiated volumes of the brachial plexus using the IMRT vs the CRT plan, respectively, were as follows: V50 (18±5 ml) vs (11±6 ml), p = 0.01; V60 (6±4 ml) vs (3±3 ml), p = 0.02; V66 (3±1 ml) vs (1±1 ml), p = 0.04, V70 (0±1 ml) vs (0±1 ml), p = 0.68. The maximum point dose to the brachial plexus was 68.9 Gy (range 62.3-78.7 Gy) and 66.1 Gy (range 60.2-75.6 Gy) for the IMRT and CRT plans, respectively (p = 0.01). CONCLUSION: Dose to the brachial plexus is significantly increased among patients undergoing IMRT compared with CRT for head and neck cancer. Preliminary studies on brachial plexus-sparing IMRT are in progress.


Assuntos
Plexo Braquial/efeitos da radiação , Neoplasias de Cabeça e Pescoço/radioterapia , Radioterapia de Intensidade Modulada/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Radioterapia Conformacional/métodos , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X
14.
Phys Rev Lett ; 102(20): 205504, 2009 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-19519041

RESUMO

Twinning in metals is normally a permanent plastic deformation mechanism. Here we report reversible twinning in high stacking fault energy (SFE) aluminum. Twinning and spontaneous detwinning at the crack tip have been captured in situ during tensile straining under a transmission electron microscope. Both the in situ observation and the molecular dynamics simulations reveal a two-stage detwinning process. The high propensity for detwinning is due to the high SFE and the low frictional forces against the detwinning partial dislocations in Al. This discovery of reversible twinning has implications for the deformation of other high SFE materials.

15.
Lett Appl Microbiol ; 44(4): 437-42, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17397484

RESUMO

AIMS: To improve viability and biocontrol efficacy of Cryptococcus laurentii after freeze drying and in subsequent storage. METHODS AND RESULTS: Viability of C. laurentii was improved after freeze drying and in subsequent storage at 4 or 25 degrees C by using skimmed milk (SM) and sugars (glucose, galactose, sucrose and trehalose) as protectants. Sugars and SM mixed together showed better protection than when they were used separately. Citric acid used as carbon source could induce accumulation of intracellular trehalose in the yeast. The yeast cells with high trehalose level (HT cells) had higher viability than those with low trehalose level (LT cells) after freeze drying and storage for 90 days. After storage for 90 days at 4 degrees C, the HT cells plus SM and sugars as protectant showed a similar biocontrol effect against blue mould rot in apple fruit caused by Penicillium expansum as fresh cells. CONCLUSIONS: Increasing intracellular trehalose content of C. laurentii and adding exogenous protectant (sugars + SM) could improve its viability and maintain its biocontrol efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: The results have a potential value for commercial application of C. laurentii.


Assuntos
Cryptococcus/fisiologia , Microbiologia de Alimentos , Malus/microbiologia , Penicillium/fisiologia , Controle Biológico de Vetores , Trealose/metabolismo , Liofilização , Galactose/farmacologia , Glucose/farmacologia , Viabilidade Microbiana , Sacarose/farmacologia , Trealose/farmacologia
16.
Ann N Y Acad Sci ; 1077: 1-32, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17124112

RESUMO

This article discusses the recirculating convection in free droplets levitated by either the electromagnetic forces or the electrostatic forces, and its effect on the measurement of thermophysical properties. In an electromagnetically levitated droplet, strong internal flow results from the vortical Lorentz forces induced by the surrounding coils. These forces are also responsible for free surface deformation. In an electrostatically levitated droplet, however, internal convection originates from the thermal gradient and the electrostatic forces are responsible for surface deformation only. Mathematical models for predicting the convection in these droplets and the surface deformations caused by either the electromagnetic or electrostatic forces are discussed. Results show that internal convection, when present, can have a significant effect on the measured data for the purpose of determining the thermophysical properties. The deformed surface assumes essentially the same oval shape in microgravity for both electromagnetically and electrostatically levitated drops. The deformation mechanism, however, is different. Future research directions in this area are also discussed.

17.
J Appl Microbiol ; 100(4): 854-61, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16553742

RESUMO

AIMS: To investigate the effects of internal trehalose on viability and biocontrol efficacy of antagonistic yeast Cryptococcus laurentii under stresses of low temperature (LT), controlled atmosphere (CA) and freeze drying. METHODS AND RESULTS: The content of trehalose in C. laurentii was increased by culturing the yeast in trehalose-containing medium. Compared with yeast cells with low trehalose level, the yeast cells with high level of internal trehalose not only obtained higher viability, but also showed higher population and better biocontrol efficacy against Penicillium expansum on apple fruit both at 1 degrees C and in CA condition (5% O(2), 5% CO(2), 1 degrees C). After freeze drying, survival of the yeast with high trehalose level was markedly increased when stored at 25 degrees C for 0, 15 and 30 days. Meanwhile, high integrity of plasma membrane was detected in the freeze-dried yeast with high trehalose level by propidium iodide staining. CONCLUSIONS: Induced accumulation of internal trehalose could improve viability and biocontrol efficacy of C. laurentii under stresses of LT and CA. Moreover, survival of the yeast was also increased as internal trehalose accumulation after freeze drying, and one of the reasons might be that trehalose gave an effective protection to plasma membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this experiment show a promising way to improve the biocontrol performance of antagonistic yeasts under the commercial conditions.


Assuntos
Cryptococcus/fisiologia , Ambiente Controlado , Controle Biológico de Vetores , Trealose/metabolismo , Atmosfera , Membrana Celular/fisiologia , Temperatura Baixa , Cryptococcus/crescimento & desenvolvimento , Meios de Cultura , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Liofilização , Malus/microbiologia , Penicillium/fisiologia
18.
J Appl Microbiol ; 100(3): 508-15, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16478490

RESUMO

AIMS: To evaluate beneficial effect of two food additives, ammonium molybdate (NH4-Mo) and sodium bicarbonate (NaBi), on antagonistic yeasts for control of brown rot caused by Monilinia fructicola in sweet cherry fruit under various storage conditions. The mechanisms of action by which food additives enhance the efficacy of antagonistic yeasts were also evaluated. METHODS AND RESULTS: Biocontrol activity of Pichia membranefaciens and Cryptococcus laurentii against brown rot in sweet cherry fruit was improved by addition of 5 mmol l(-1) NH4-Mo or 2% NaBi when stored in air at 20 and 0 degrees C, and in controlled atmosphere (CA) storage with 10% O2 + 10% CO2 at 0 degrees C. Population dynamics of P. membranefaciens in the wounds of fruit were inhibited by NH4-Mo at 20 degrees C after 1 day of incubation and growth of C. laurentii was inhibited by NH4-Mo at 0 degrees C in CA storage after 60 days. In contrast, NaBi did not significantly influence growth of the two yeasts in fruit wounds under various storage conditions except that the growth of P. membranefaciens was stimulated after storage for 45 days at 0 degrees C in CA storage. When used alone, the two additives showed effective control of brown rot in sweet cherry fruit and the efficacy was closely correlated with the concentrations used. The result of in vitro indicated that growth of M. fructicola was significantly inhibited by NH4-Mo and NaBi. CONCLUSION: Application of additives improved biocontrol of brown rot on sweet cherry fruit under various storage conditions. It is postulated that the enhancement of disease control is directly because of the inhibitory effects of additives on pathogen growth, and indirectly because of the relatively little influence of additives on the growth of antagonistic yeasts. SIGNIFICANCE AND IMPACT OF THE STUDY: The results obtained in this study suggest that an integration of NH4-Mo or NaBi with biocontrol agents has great potential in commercial management of postharvest diseases of fruit.


Assuntos
Ascomicetos/fisiologia , Aditivos Alimentares/farmacologia , Doenças das Plantas/microbiologia , Prunus/microbiologia , Leveduras/crescimento & desenvolvimento , Ascomicetos/efeitos dos fármacos , Cryptococcus/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Manipulação de Alimentos/métodos , Molibdênio/farmacologia , Controle Biológico de Vetores/métodos , Pichia/crescimento & desenvolvimento , Bicarbonato de Sódio/farmacologia , Temperatura
19.
Microsc Res Tech ; 64(5-6): 347-55, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15549702

RESUMO

We describe the new coherent nano-area electron diffraction (NED) and its application for structure determination of individual nanostructures. The study is motivated by the challenge and the general lack of analytical techniques for characterizing nanometer-sized, heterogeneous phases. We show that by focusing electrons on the focal plane of the pre-objective lens using a 3rd condenser lens and a small condense aperture, it is possible to achieve a nanometer-sized highly parallel illumination or probe. The high angular resolution of diffraction pattern from the parallel illumination allows over-sampling and consequently the solution of phase problem based on the recently developed ab initio phase retrieval technique. From this, a high-contrast and high-resolution image can be reconstructed at resolution beyond the performance limit of the image-forming objective lens. The significance of NED for nanostructure characterization will be exemplified by single-wall carbon nanotubes and small metallic clusters. Imaging from diffraction patterns, or diffractive imaging, will be demonstrated using double-wall carbon nanotubes.


Assuntos
Processamento de Imagem Assistida por Computador , Microscopia Eletrônica de Transmissão/métodos , Nanoestruturas/química , Nanotubos de Carbono/química , Transição de Fase , Simulação por Computador , Cristalografia
20.
J Microw Power Electromagn Energy ; 39(3-4): 153-65, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-16480158

RESUMO

This paper presents an integrated electromagnetic and thermal model for the microwave processing offood packages. The model is developed by combining the edge finite element formulation of the 3-D vector electromagnetic field in the frequency domain and the node finite element solution of the thermal conduction equation. Both mutual and one-way coupling solution algorithms are discussed. Mutual coupling entails the iterative solution of the electromagnetic field and the thermal field, because the physical properties are temperature-dependent. The one-way coupling is applicable when the properties are temperature independent or this dependence is weak. Mesh sensitivity and shape regularity for the edge element based formulation for computational electromagnetics are discussed in light of available analytical solutions for a simple wave guide. The integrated model has been used to study the electromagnetic and thermal phenomena in a pilot scale microwave applicator with and without the food package immersed in water. The calculated results are compared with the experimentally measured data for the thermal fields generated by the microwave heating occurring in a whey protein gel package, and reasonably good agreement between the two is obtained.


Assuntos
Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Alimentos/efeitos da radiação , Micro-Ondas , Modelos Teóricos , Radiometria/métodos , Esterilização/métodos , Simulação por Computador , Doses de Radiação
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