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Article in Chinese | WPRIM | ID: wpr-888322


OBJECTIVE@#To investigate the application value of liquid crystal digital display goniometer in total hip arthroplasty.@*METHODS@#From January 2018 to December 2019, 83 patients underwent primary total hip arthroplasty, including 28 males and 55 females, aged 42 to 81 (70.4±7.9) years. There were 63 cases of femoral neck fracture and 20 cases of avascular necrosis of femoral head. All patients used liquid crystal digital goniometer to control the anteversion of acetabular cup prosthesis during operation, and CT scanning was used to measure the anteversion of acetabular cup after operation. The two methods were compared to understand the accuracy of using liquid crystal digital goniometer.@*RESULTS@#Postoperative CT measurement showed that the acetabular anteversion of all patients was in the safe area advocated by Lewinnek. The anteversion angle of acetabular cup measured by liquid crystal digital goniometer was 14.20(12.80 to 15.40)°, and the anteversion angle of acetabular cup measured by postoperative CT scan was 14.20 (13.40 to 15.50)°. There was no significant difference between the two (@*CONCLUSION@#It is an accurate and reliable method to control the anteversion of acetabular cup with liquid crystal digital display angle instrument, which has a good auxiliary reference value.

Acetabulum/surgery , Arthroplasty, Replacement, Hip , Female , Hip Prosthesis , Humans , Liquid Crystals , Male , Retrospective Studies
Article in Korean | WPRIM | ID: wpr-811325


PURPOSE: We developed a novel method for measurement of hyperacuity and verified the utility thereof.METHODS: We developed a three-dimensional (3D) hyperacuity test using a 3D liquid crystal flat screen, a left- and right-image polarized display, and liquid crystal shutter glasses. We tested the technique in three groups: normal (n = 48), with cataracts (n = 14), and with macular disease (n = 35). We used a chart consisting of five dots and a reference line. Of the five dots, one was variably shifted from the other dots. A chart was presented to one eye and the reference line or blank image to the other eye; a subject scored positive when the dot in the unusual position was recognized.RESULTS: Hyperacuity was measured in terms of the reference line seen by the reference eye (RR), a blank image seen by the reference eye (RB), the reference line seen by the contralateral eye (CR), and a blank image seen by the contralateral eye (CB). All test scores were significantly lower when the reference line was seen than not (RR vs. RB and CR vs. CB; p < 0.01, respectively). For the RR and CR tests, no significant difference was apparent between the normal and cataracts group (p = 0.553, p = 0.494) but such differences were evident between the normal and macular disease groups (p = 0.028, p = 0.002). Also, visualization of the reference line by the reference and contralateral eyes did not differ (p > 0.05).CONCLUSIONS: Measurement of hyperacuity using our new method was not affected by media opacity but was significantly affected by macular disease. Presentation of a reference line facilitated hyperacuity assessment.

Cataract , Eyeglasses , Glass , Liquid Crystals , Methods
Article in English | WPRIM | ID: wpr-766140


OBJECTIVES: The Samsung Ombudsperson Commission was launched as an independent third-party institution following an agreement among Samsung Electronics, Supporters for Health and Right of People in Semiconductor Industry (Banolim in Korean, an independent NGO), and the Family Compensation Committee, in accordance with the industry accident prevention measure required by the settlement committee to address the issues related to employees who allegedly died from leukemia and other diseases as a result of working at Samsung's semiconductor production facilities. METHODS: The Commission has carried out a comprehensive range of activities to review and evaluate the status of the company's occupational accidents management system, as well as occupational safety and health risk management within its facilities. RESULTS: Based on the results of this review, termed a comprehensive diagnosis, the Commission presented action plans for improvement to strengthen the company's existing safety and health management system and to effectively address uncertain risks in this area going forward. CONCLUSIONS: The Commission will monitor the execution of the suggested tasks and provide advice and guidance to ensure that Samsung's semiconductor and liquid crystal display production lines are safer.

Accident Prevention , Accidents, Occupational , Compensation and Redress , Diagnosis , Humans , Korea , Leukemia , Liquid Crystals , Occupational Diseases , Occupational Health , Risk Management , Semiconductors
Rev. cuba. med. trop ; 69(3): 1-15, set.-dic. 2017.
Article in Spanish | LILACS, CUMED | ID: biblio-901256


El dengue es una enfermedad viral transmitida por mosquitos que puede ser causa de gravedad y muerte. No existe droga antiviral reconocida como eficaz. Sin embargo, las regularidades de esta enfermedad han permitido la identificación de signos de alarma que anuncian extravasación de plasma e inminencia del choque. El inicio precoz del tratamiento de los pacientes mediante la reposición de líquidos cristaloides por vía intravenosa ha demostrado ser una medida efectiva y salvadora. Se necesita capacitación sistemática y acciones de reorganización de la atención médica en función de la epidemia. Se expone la contribución de los profesionales del Instituto de Medicina Tropical Pedro Kourí y otras instituciones cubanas a ese empeño(AU)

Dengue is a viral disease transmitted by mosquitoes which may be severe and cause death. No antiviral drug has been recognized as effective. However, the regularities of this condition have made it possible to identify warning signs announcing plasma leakage and the imminence of shock. Early start of treatment with intravenous crystalloid fluid replacement has proven to be an effective, life-saving measure. Systematic training actions and reorganization of medical care are required during an epidemic. The paper describes the contribution of professionals from Pedro Kouri Tropical Medicine Institute and other Cuban institutions to this effort(AU)

Humans , Male , Female , Severe Dengue/prevention & control , Dengue/mortality , Dengue/therapy , Cuba , Dengue/diagnosis , Liquid Crystals/standards
Braz. J. Pharm. Sci. (Online) ; 53(3): e00051, 2017. tab, graf, ilus
Article in English | LILACS | ID: biblio-889400


ABSTRACT This study was to develop, characterize, and evaluate the physical-chemical stability, in vitro antioxidant activity and in vitro safety profile of liquid crystalline systems (LCS) and microemulsions (MEs) with and without organic cocoa (OC) extract. LCS stabilized by surfactant polyoxyethylene 20 cetyl ether, containing water and oleic acid were studied. LCS and MEs were characterized using polarized light microscopy, small angle X-ray scattering, rheology and in vitro bioadhesion, and were evaluated for a period of 30 days by visual aspects, centrifuge test, pH value and relative density. PLM and SAXS assays showed the presence of domains of MEs, cubic and hexagonal mesophasephases, varying the proportions of the components of the formulations; where in the addition of the extract did not change rheological behavior of the formulations. All of the formulations were stable in the period analyzed and presented higher bioadhesive strength. In vitro antioxidant activity suggests that LCS and MEs presented a high capacity to maintain the antioxidant activity of OC extract. The results showed that the incorporation of OC in LCS improved the safety profile, according to cytotoxicity assays of systems may be a promising platform to OC extract for topical application for the potential treatment of skin disorders.

Surface-Active Agents , Liquid Crystals/analysis , Skin , Cacao/adverse effects , Drug Delivery Systems , Microscopy, Polarization/methods
Braz. j. pharm. sci ; 52(3): 383-390, July-Sept. 2016. tab, graf
Article in English | LILACS | ID: biblio-828272


ABSTRACT Liquid crystal systems (LCSs) have interesting cosmetic applications because of their ability to increase the therapeutic efficiency and solubility of active ingredients. The aim of the present research was to develop green tea glycolic extract-loaded LCSs, to characterize and to perform microbiological control. The ternary phase diagram was constructed using polysorbate 20, silicone glycol copolymer (SGC) - DC 193(r), and distilled water with 1.5% glycolic green tea extract. The systems were characterized by polarized light microscopy. Formulations selected were characterized as transparent viscous systems and transparent liquid system indicated mesophases lamellar structure. The results of the microbiological analysis of mesophilic aerobic microorganisms (bacteria and fungi) revealed that the above formulation showed a biologic load <10 CFU/mL in all samples. In conclusion, liquid crystalline systems that have presented formation of a lamellar mesophases were developed. Furthermore, the formulation and products tested presented the adequate microbiological quality in accordance with official recommendations.

Camellia sinensis/classification , Liquid Crystals/microbiology , Liquid Crystals/statistics & numerical data , Microbiological Techniques/analysis , Cosmetic Microbiology , Cosmetics/analysis
Braz. j. pharm. sci ; 52(1): 211-220, Jan.-Mar. 2016. tab, graf
Article in English | LILACS | ID: lil-789074


ABSTRACT Liquid-Crystalline Systems represent active compounds delivery systems that may be able to overcome the physical barrier of the skin, especially represented by the stratum corneum. To obtain these systems, aqueous and oily components are used with surfactants. Of the different association structures in such systems, the liquid-crystalline offer numerous advantages to a topical product. This manuscript presents the development of liquid-crystalline systems consisting, in which the oil component is olive oil, its rheological characterizations, and the location of liquid crystals in its phase map. Cytotoxic effects were evaluated using J-774 mouse macrophages as the cellular model. A phase diagram to mix three components with different proportions was constructed. Two liquid crystalline areas were found with olive oil in different regions in the ternary diagram with two nonionic surfactants, called SLC1 (S1) and SLC2 (S2). These systems showed lamellar liquid crystals that remained stable during the entire analysis time. The systems were also characterized rheologically with pseudoplastic behavior without thixotropy. The texture and bioadhesion assays showed that formulations were similar statistically (p < 0.05), indicating that the increased amount of water in S2 did not interfere with the bioadhesive properties of the systems. In vitro cytotoxic assays showed that formulations did not present cytotoxicity. Olive oil-based systems may be a promising platform for skin delivery of drugs.

RESUMO Os cristais líquidos representam um sistema de liberação de substâncias ativas capazes de vencer a barreira cutânea, representada especialmente pelo estrato córneo. Água, óleo e tensoativos são misturados para se obter esses sistemas. Diferentes estruturas podem ser formadas nesses sistemas, as quais oferecem muitas vantagens para os produtos de uso tópico. Esse trabalho visou ao desenvolvimento de sistemas líquido-cristalinos preparados com óleo de oliva, sua caracterização reológica e a identificação das fases cristalinas no diagrama ternário. Efeitos citotóxicos foram avaliados usando células de rato como modelo celular. Construiu-se um diagrama de fases que mistura três componentes em diferentes proporções. Duas áreas de cristal líquido, denominadas SLC1 (S1) e SLC2 (S2), foram encontradas com óleo de oliva em diferentes regiões no diagrama ternário preparado com dois diferentes tensoativos não-iônicos. Esses sistemas mostraram fase cristalina lamelar, que permaneceu estável durante o tempo estudado. Os sistemas foram também caracterizados reologicamente e apresentaram comportamento pseudoplástico com tixotropia. Os ensaios de textura e bioadesão mostraram que as formulações foram similares (p < 0.05), indicando que o aumento da quantidade de água em S2 não interferiu nas propriedades bioadesivas dos sistemas. Os ensaios de citotoxicidade mostraram que as formulações não foram citotóxicas. Sistemas à base de óleo de oliva são interessantes para a liberação de fármacos na pele.

Nanotechnology/methods , Olive Oil/therapeutic use , Drug Liberation , Liquid Crystals/analysis , Rheology/classification
Acta Pharmaceutica Sinica ; (12): 132-139, 2016.
Article in Chinese | WPRIM | ID: wpr-320004


Phytantriol (PT), ethanol (ET) and water were used to prepare in situ cubic liquid crystal (ISV2). The pseudo-ternary phase diagram of PT-ET-water was constructed and isotropic solution formulations were chosen for further optimization. The physicochemical properties of isotropic solution formulations were evaluated to optimize the composition of ISV2. In situ hexagonal liquid crystals (ISH2) were prepared based on the composition of ISV2 with the addition of vitamin E acetate (VitEA) and the amount of VitEA was optimized by in vitro release behavior. The phase structures of liquid crystalline gels formed by ISV2 and ISH2 in excess water were confirmed by crossed polarized light microscopy and small angle X-ray scattering, respectively. Rheological properties of ISV2 and ISH2 were studied by a DHR-2 rheometer. In vitro drug release studies were conducted by using a dialysis membrane diffusion method. Pharmacokinetics was investigated by determination of sinomenine hydrochloride (SMH) concentration in synovial membrane after intra-articular injection of SMH-loaded ISH2 in adjuvant-induced arthritis rats. The optimal ISV2 (PT/ET/water, 64 : 16 : 20, w/w/w) loaded with 6 mg x g(-1) of SMH showed a suitable pH, injectable and formed a cubic liquid crystalline gel in situ with minimum water absorption in the shortest time. The optimal ISV2 was able to sustain the drug release for 144 h. The optimal ISH2 system was prepared by addition of 5% VitEA into PT in the optimal ISV2 system. This ISH2 (PT/VitEA/ET/water, 60.8 : 3.2 : 16 : 20, w/w/w/w) was an injectable isotropic solution with suitable pH. The new ISH2 was able to sustain the drug release for more than 240 h. Local pharmacokinetics study indicated that the retention time and AUC(0-∞) of ISH2 group were increased significantly compared with that of SMH solution group and the AUC(0-∞) of ISH2 group was 6.01 times higher than that of SMH solution group. The developed ISH2 was suitable for intra-articular injection that may apply to patients in the treatment of rheumatoid arthritis.

Animals , Chemistry, Pharmaceutical , Diffusion , Ethanol , Fatty Alcohols , Gels , Injections, Intra-Articular , Liquid Crystals , Morphinans , Chemistry , Rats , Rheology , Water , alpha-Tocopherol
Article in English | WPRIM | ID: wpr-145527


PURPOSE: In elderly and patients with underlying diseases, mortality rate is increased when compared to rib fractures which occurred in other patients. Because there is a shortage of emergency physicians or real-time consultation with radiologists in many countries, it is necessary to receive a formal image reading remotely from an expert. We suggested the use of iPad in X-ray reading and compared the diagnostic validity of iPad, which was highly portable, with that of liquid crystal display (LCD) monitor. METHODS: Fifty four X-ray cases of rib fracture and 54 cases without rib fracture were randomized and reviewed by 10 emergency physicians. A total of 108 cases were divided 1st to 54th and 55th to 108th. Two sessions were separated with a four-week interval. If the reviewer interpreted the 1st to 54th with iPad, they did 55th to 108th with LCD monitor. Reviewers reported the presence of rib fracture, the number of fractured ribs, and diagnostic confidence of 5-scale. RESULTS: The interobserver agreement among reviewers in LCD and iPad was 0.551, 0.524 in Fleiss-kappa value. The intraobserver agreement between tools for each reviewer was 0.410-0.859 (Mean=0.628+/-0.150). Reviewers showed sensitivity over 0.810 regardless of the tool; 0.810- 0.966 (Mean=0.879+/- 0.054) in LCD, 0.828-1.000 (Mean=0.898+/-0.052) in iPad. The specificity was 0.520- 0.860 (Mean=0.750+/-0.117) in LCD and 0.560-0.880 (Mean=0.708+/-0.111) in iPad. Therefore, remote consultation of X-ray by iPad with a specialist was possible with minimized temporal and spatial limits in the emergency room. CONCLUSION: In our study, there was no statistical difference in the diagnosis of rib fracture by X-ray via iPad or LCD. Therefore, remote consultation of X-ray by iPad with a specialist in the emergency room was possible, with temporal and spatial limits by iPad.

Aged , Diagnosis , Emergencies , Emergency Service, Hospital , Humans , Liquid Crystals , Mortality , Remote Consultation , Rib Fractures , Ribs , Sensitivity and Specificity , Specialization , Teleradiology
Article in Chinese | WPRIM | ID: wpr-350535


<p><b>OBJECTIVE</b>To understand the exposed positions and levels of indium and its compounds in manufacture of liquid crystal displays, and to evaluate the degree of occupational hazard from indium and its compounds.</p><p><b>METHODS</b>On-site investigation of occupational health, occupational hazard monitoring, and occupational health examination were used to evaluate the degree of occupational hazard from indium and its compounds in three manufacturers of liquid crystal display panel in Shenzhen, Guangdong, China.</p><p><b>RESULTS</b>The time-weighted average (TWA) and short-term exposure limit (STEL) concentrations of indium and its compounds to which sputtering machine operating positions were exposed were less than 0.002~0.004 mg/m³ and 0.006~0.007 mg/m³, respectively, both of which complied with the National Hygienic Standard (PC-TWA = 0.1 mg/m³; PC-STEL = 0.3 mg/m³); the TWA and STEL concentrations of indium and its compounds to which grinding positions were exposed were 0.114~2.98 mg/m³ and 0.31~10.02 mg/m³, respectively, both of which exceeded the National Hygienic Standard with the highest concentration 33-fold higher than the standard. No significant health damages were found in exposed workers according to the results of occupational health examination.</p><p><b>CONCLUSION</b>The grinding positions are the key to the control of occupational hazard from indium and its compounds in manufacture of liquid crystal display panel. The workers should be equipped with the anti-particulate full-face respirator, which is an effective way to prevent occupational hazard from indium and its compounds.</p>

Air Pollutants, Occupational , Toxicity , China , Data Display , Humans , Indium , Toxicity , Liquid Crystals , Occupational Exposure , Occupational Health , Risk Assessment , Threshold Limit Values
Braz. j. pharm. sci ; 50(2): 381-389, Apr-Jun/2014. tab, graf
Article in English | LILACS | ID: lil-722182


In recent decades, there has been a significant increase in the incidence of fungal diseases. Certain fungal diseases cause cutaneous lesions and in the usual treatment, generally administred orally, the drug reaches the site of action with difficulty and its concentration is too low. An approach much explored in recent years is the development of nanotechnology-based drug delivery systems, and microemulsions (ME) and liquid crystals (LC) are promising. ME and LC were developed with oleic acid or copaiba oil as the oil phase, propoxyl (5OP) ethoxyl (20 OE) cetyl alcohol as surfactant and water. An analytical method to assess the incorporation of fluconazole (FLU) in the systems under study was validated according to guidelines of the International Conference on Harmonization (ICH) guidelines and the Brazilian Food, Drug and Sanitation Agency (ANVISA). The method was conducted on a C18-RP column (250 × 4.6 mm i.d.), maintained at room temperature. The mobile phase consisted of acetonitrile and water (50:50, v/v), run at a flow rate of 1.0mL/min and using ultraviolet detection at 210nm. The chromatographic separation was obtained with a retention time of 6.3min, and was linear in the range of 20-400 µg/mL (r2=0.9999). The specificity showed no interference of the excipients. The accuracy was 100.76%. The limits of detection and quantitation were 0.057 and 0.172 µg.mL-1, respectively. Moreover, method validation demonstrated satisfactory results for precision and robustness. The proposed method was applied for the analysis of the incorporation of FLU in ME and LC, contributing to improve the quality control and to assure the therapeutic efficacy.

Nas últimas décadas, houve aumento significativo na incidência de doenças fúngicas. Certas doenças fúngicas provocam lesões cutâneas, sendo que no tratamento usual, geralmente administrado por via oral, o medicamento chega ao local de ação com dificuldade, em concentração muito baixa. Uma abordagem muito explorada nos últimos anos é o desenvolvimento de sistemas de administração de fármacos baseados em nanotecnologia, como as microemulsões (ME) e cristais líquidos (LC). ME e LC foram desenvolvidos com o ácido oleico ou óleo de copaíba como fase oleosa, álcool cetílico propoxilado (5 OP) e etoxilado (20 OE) como tensoativo e água. Método analítico para avaliar a incorporação de fluconazol (FLU) nos sistemas em estudo foi validado de acordo com as diretrizes da Conferência Internacional de Harmonização (ICH) e Agência Nacional de Vigilância Sanitária (ANVISA). O método foi desenvolvido empregando coluna C18-RP (250 x 4,6 mm id), mantida à temperatura ambiente. A fase móvel consistiu de acetonitrila e água (50:50, v/v), executado a uma taxa de fluxo de 1,0 mL/min e com detecção ultravioleta a 210 nm. A separação cromatográfica foi obtida com o tempo de retenção de 6,3min, e mostrou-se linear no intervalo de 20-400 µg/mL (r2=0,9999). Pelo estudo de especificidade, observou-se não interferência dos excipientes. A precisão foi 100,76%. Os limites de detecção e de quantificação foram 0,057 e 0,172 µg.mL-1, respectivamente. Além disso, a validação do método demonstrou resultados satisfatórios para a precisão e robustez. O método proposto foi aplicado para a análise da incorporação do FLU em ME e cristais líquidos, contribuindo para aumentar o controle de qualidade e garantir a eficácia terapêutica.

Chromatography, Liquid/classification , Fluconazole/analysis , Liquid Crystals/classification , Validation Studies as Topic , Nanotechnology/classification
Acta Pharmaceutica Sinica ; (12): 1069-1075, 2014.
Article in Chinese | WPRIM | ID: wpr-299165


The purpose of this study is to investigate the preparation of hydroxycamptothecine (HCPT)-loaded cubic crystal liquid embolic precursor solution, and evaluate its in vitro embolic efficiency. Phytantriol was used as cubic crystal liquid embolic material, and the optimal formulation was selected according to ternary phase diagram. Polarized light microscopy, differential scanning calorimetry, and small angle X-ray scattering (SAXS) were used to characterize the cubic crystal structure. High performance liquid chromatography and X-ray diffraction analysis were used to investigate the lactone ring of HCPT. In vitro dissolution was preliminary evaluated, and the simulation embolic model was constructed to evaluate the embolic efficiency of precursor solution. Meanwhile, the gelation time and adhesion force were investigated. The results showed that HCPT-loaded precursor solution for embolization had been successfully prepared with low viscosity which was injectable. The precursor solution could transform into Pn3m structure liquid crystal phase gel rapidly when contracting with excess water. The formed HPCT gel remained its lactone form as the same in precursor solution, and expressed the good ability to block the saline flow, and HCPT could keep sustained releasing drug over 30 days. The prepared drug-loaded embolic precursor solution showed a promising potential for vascular embolization and application in clinical treatment of tumor.

Antineoplastic Agents, Phytogenic , Chemistry , Calorimetry, Differential Scanning , Camptothecin , Chemistry , Delayed-Action Preparations , Chemistry , Fatty Alcohols , Chemistry , Liquid Crystals , Scattering, Small Angle , Water , X-Ray Diffraction
Article in Chinese | WPRIM | ID: wpr-234471


Pulse waves contain rich physiological and pathological information of the human vascular system. The pulse wave diagnosis systems are very helpful for the clinical diagnosis and treatment of cardiovascular diseases. Accurate pulse waveform is necessary to evaluate the performances of the pulse wave equipment. However, it is difficult to obtain accurate pulse waveform due to several kinds of physiological and pathological conditions for testing and maintaining the pulse wave acquisition devices. A pulse wave generator was designed and implemented in the present study for this application. The blood flow in the vessel was simulated by modeling the cardiovascular system with windkessel model. Pulse waves can be generated based on the vascular systems with four kinds of resistance. Some functional models such as setting up noise types and signal noise ratio (SNR) values were also added in the designed generator. With the need of portability, high speed dynamic response, scalability and low power consumption for the system, field programmable gate array (FPGA) was chosen as hardware platform, and almost all the works, such as developing an algorithm for pulse waveform and interfacing with memory and liquid crystal display (LCD), were implemented under the flow of system on a programmable chip (SOPC) development. When users input in the key parameters through LCD and touch screen, the corresponding pulse wave will be displayed on the LCD and the desired pulse waveform can be accessed from the analog output channel as well. The structure of the designed pulse wave generator is simple and it can provide accurate solutions for studying and teaching pulse waves and the detection of the equipments for acquisition and diagnosis of pulse wave.

Algorithms , Equipment Design , Heart Rate , Humans , Liquid Crystals , Models, Cardiovascular , Pulse Wave Analysis , Regional Blood Flow
Article in Portuguese | LILACS | ID: lil-705083


A monoleína é um lipídeo polar capaz de absorver água e formar sistemas líquido-cristalinos, os quais são utilizados como sistemas de liberação para administração de vários fármacos. Neste estudo foi avaliado o potencial de sistemas de fase lamelar constituídos por monoleína e água para veicular polihexametilenobiguanida (PHMB). A formação dos sistemas líquido-cristalinos foi caracterizada por microscopia de luz polarizada. Estudos de intumescimento foram realizados gravimetricamente em várias condições avaliando-se os efeitos de parâmetros como pH, força iônica e temperatura do meio de imersão. O processo de intumescimento foi caracterizado através da obtenção dos perfis de intumescimento e análise de sua cinética, além da determinação da capacidade máxima de intumescimento dos sistemas. Os sistemas de fase lamelar foram obtidos em presença de PHMB, os quais absorveram água rapidamente de acordo com cinética de segunda ordem e sofreram transição de fase, formando a fase cúbica. O intumescimento dos sistemas não foi influenciado pela presença do fármaco nos vários meios de imersão estudados, exceto pela imersão em meio ácido, no qual a presença do PHMB aumentou a captação de água. O intumescimento dos sistemas contendo PHMB não foi afetado pela força iônica do meio de imersão, porém foi diminuído com o aumento da temperatura. Desta maneira, sistemas líquido-cristalinos de monoleína e água foram obtidos e o processo de intumescimento foi caracterizado. Os sistemas apresentaram potencial para serem propostos como sistemas de liberação para administração de PHMB e estudos de liberação de fármacos serão realizados futuramente.

Monoolein is a polar lipid that absorbs water and forms liquid crystalline systems that are used as drug delivery systems for different medications. The aim of the present study was to investigate lamellar phases formed by monoolein and water as potential vehicles for the administration of polyhexamethylene biguanide (PHMB). Lamellar phase systems formed by monoolein and water containing PHMB were characterized by polarizing microscopy. Swelling studies were performed gravimetrically under different conditions for the evaluation of the effects of pH, ionic strength and temperature. Analyses of swelling profiles, swelling kinetics and maximum swelling capacity were performed. The lamellar phase systems of monoolein and water obtained in the presence of PHMB absorbed water very quickly following second-order swelling kinetics and formed a cubic phase. The swelling of the systems was not influenced by the presence of the drug in the immersion media studied, except under acidic conditions, in which the drug exhibited increased water uptake. The swelling of systems containing PHMB was not affected by the ionic strength of the immersion media, but was reduced with an increase in temperature. Liquid crystalline systems of monoolein and water were obtained and swelling behavior was investigated. The systems exhibited the potential for use as a drug delivery system for PHMB administration. However, further drug-release studies should be performed.

Liquid Crystals , Lipids/biosynthesis , Pharmaceutical Preparations/analysis , Chemistry, Pharmaceutical/methods , Rheology/methods
Article in Portuguese | LILACS | ID: lil-705096


Os frutos de cacau (Theobroma cacao) são conhecidos mundialmente pela sua riqueza em ácidos graxos e compostos fenólicos com poder antioxidante, sendo que em sua constituição é possível relatar mais de 50% em ácidos graxos de cadeia média que o torna matéria-prima passível de ser explorada pela indústria alimentícia, farmacêutica e cosmética. Este trabalho teve como objetivo estudar o poder antioxidante do extrato seco de cacau orgânico, obter formulações cosméticas acrescidas deste extrato, promovendo os estudos de estabilidade, ensaios reológicos e a investigação de cristais-líquidos, bem como realizar o teste de aceitação das mesmas. O extrato vegetal foi avaliado quanto seu poder antioxidante pelo método de sequestro radicalar DPPH. Formulações cosméticas foram obtidas e amostras foram submetidas a ensaios físico-químicos de estabilidade (caracterização organoléptica, teste de centrífuga e determinação dos valores de pH), caracterização reológica, assim como análises em microscopia de luz polarizada. As preparações estáveis também foram avaliadas quanto a sua aceitabilidade por provadores. A partir dos resultados apresentados pôde-se constatar a atividade antioxidante do extrato seco de cacau orgânico e obter preparações cosméticas, constituídas deste ativo a 5%, com comportamento pseudoplástico associado à tixotropia e providas de cristais líquidos lamelares. Verificou-se também que a concentração de cera autoemulsionante interferiu na aceitação do produto cosmético.

The cocoa fruit (Theobroma cacao) is known worldwide for its richness in fatty acids and phenolic compounds, with antioxidant power, and it is known to be composed of more than 50% medium-chain fatty acids, making it a raw material that could be exploited by the food, pharmaceutical and cosmetics industries. the aim of this study was to assess the antioxidant power of organic cocoa dried extract, to develop cosmetic formulations from this extract and to determine their stability and carry out rheological tests, liquid-crystal research and acceptance testing on them. the plant extract was assayed for its antioxidant power by the DPPH radical scavenging method. Cosmetic formulations were produced and samples were subjected to physicochemical stability tests (organoleptic assessment, centrifugal testing and determination of pH), rheological characterization and polarized light microscopy analysis. the stable preparations were also evaluated for their acceptability by consumers. From the results presented, it was possible to characterize the antioxidant activity of dried organic cocoa extract and to prepare cosmetic preparations containing 5% of this active compound. these showed pseudoplastic behavior associated with thixotropy and lamellar liquid crystals were presentat all storage times and temperatures. It was also found that the higher self-emulsifying wax contents interfered with consumer acceptance of the cosmetic product.

Humans , Cacao , Cosmetics , Liquid Crystals , Plant Extracts , Rheology
Article in Chinese | WPRIM | ID: wpr-234629


A stable, uniform, easily implemented, LC-based chemical and biological sensor substrate for orientations of liquid crystals (LCs) for a long-term is urgently needed for medical applications of the sensors. We proposed a use of spin-coating of copper perchlorate (Cu(ClO4)2), with five different concentrations(0-100mmol/L), directly on glass slides for fabricating a layer of chemically-sensitive copper ions. Observing the transmitted light with a polarized microscope, we found the luminosity of the light propagated through sensors deposited with copper ions started to weaken gradually after a certain time. The higher was the concentration of copper ions covered on the glass substrates of the sensors, the faster the weakening occurred, and the less time was needed for transmitted light to turn completely dark. But there was no change in luminosity of the transmitted light for the sensors without Cu(ClO4)2 spin-coating even after stored at room temperature (25 degrees C) for a whole day. When the Cu(ClO4)2 deposited sensors were stored within a drying oven at room temperature (25 degrees C) for 2 months, it was found that there vas almost no change in luminosity of the transmitted lights. The results showed that all the thin films of LC on glass slides functionalized with Cu(ClO4)2 could keep homeotropic and stable orientation for a long time; the concentration of Cu (ClO4)2I has an influence on the orientation response speed of LC from planar to perpendicular orientation.

Biosensing Techniques , Copper , Chemistry , Glass , Chemistry , Liquid Crystals , Chemistry
Article in English | WPRIM | ID: wpr-77641


OBJECTIVES: In this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device. METHODS: The metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2*-weighted gradient echo sequences, respectively. RESULTS: In the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system. CONCLUSION: The novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging.

Artifacts , Auditory Perception , Brain , Chimera , Cochlear Implantation , Cochlear Implants , Electrons , Hand , Head , Liquid Crystals , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Magnetics , Magnets , Polymers
Article in Chinese | WPRIM | ID: wpr-342916


Based on LCD Module and Visual C++ development environment, this paper proposes a new method which can quickly develop the human-machine interface .We define a LCD module programming interface by designing Serial Communication Class(SCS). On this basis,we achieve the transplantation on an Embedded ARM Platform to fulfil the requirements of Medical Diagnostic Instruments (MDI). Experimental results show that this method has advantages of short development cycle and high level transplantation which has broad application prospects in the field of Medical Diagnosis Instrument.

Diagnosis, Computer-Assisted , Equipment Design , Liquid Crystals , Robotics , Methods , Software , User-Computer Interface
Rev. imagem ; 33(1/2): 1-6, jan.-jun. 2011. ilus, tab, graf
Article in Portuguese | LILACS | ID: lil-644367


OBJETIVO: O objetivo deste trabalho foi avaliar o desempenho de 24 monitores LCD utilizados nos laudos médicos, segundo testes recomendados pelo AAPM Report 03, de 2005. MATERIAL E MÉ-TODO: Os testes foram realizados de acordo com o AAPM Report 03 de 2005, em parâmetros como: distorção geométrica, reflexão, uniformidade e resposta de luminância, contraste, resolução, ruído e velamento por reflexão interna, com auxílio de fotômetro ou visualmente. RESULTADOS: Apresentaram-se problemas de: ruído (38% das estações de trabalho), resposta de luminância econtraste (33%) e uniformidade da luminância (4%). CONCLUSÃO: Em razão de o modelo MDNC4130 estar configurado para maximizar a vida útil, sua luminância é baixa, fazendo com que ruídos causados por sujeira comprometam a imagem. Em retestes, mostrou-se que a limpeza periódica dosmonitores resolve este problema. Já no caso das não conformidades em luminância e contraste, percebeu-se que a calibração automática com o software do monitor nem sempre corrige as distorções apresentadas.

OBJECTIVE: The purpose of this paper was to investigate the imagequality of 24 display devices and to compare the results of performance. MATERIAL AND METHOD: Tests were executed following AAPM Report 03 on 24 display devices installed in the Instituto de Radiologia do Hospital das Clínicas, São Paulo, SP, Brazil.The evaluation of test pattern considered these parameters:geometric distortions, luminance uniformity and response, contrast,reflections, resolution, and noise. RESULTS: The problems found were: noise (38% of workstations), luminance and contrast (33%) and luminance uniformity (4%). CONCLUSION: The model MDNC4130 was setting to preserve the life of display device, then the luminance is low, making the noise caused by dirt compromising image. The new test showed that regular cleaning of displaydevices solves this problem. In the case of non compliance of luminance and constrast realized that the automatic calibration of the display devices is not always correct the distortions.

Liquid Crystals , Monitoring Stations , Quality Control , Radiographic Image Enhancement , Radiology
Sudan Medical Monitor. 2011; 6 (3): 229-236
in English | IMEMR | ID: emr-118307


We have synthesized some of glycolipids which can be used as a model for studying the behavior of the cell membrane. We used monosaccharide and disaccharide sugars as the carbohydrate moieties while the lipid moieties derived from Guerbet alcohols. These alcohols are branched at position 2. Liquid crystals studies on these synthetic glycolipids have been carried out using optical polarizing microscopy, differential scanning calorimetry and small angle X-ray scattering. Interesting phase behaviour has been observed for these branched chain glycolipids to compared to those of straight counterparts

Cell Membrane/physiology , Cell Membrane/chemistry , Glycolipids/chemistry , Liquid Crystals , Calorimetry, Differential Scanning