Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
J Obstet Gynaecol Can ; 40(3): 317-327, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29054509

RESUMO

OBJECTIVE: Ovarian cancer is the most lethal gynaecologic cancer. Disease prevention may be the only method to reduce the incidence of ovarian cancer. The Society of Gynecologic Oncology advised that salpingectomies may be an appropriate and feasible strategy for ovarian cancer risk reduction. This study conducted an economic evaluation from a societal perspective of bilateral salpingectomies versus conventional sterilization techniques in the prevention of ovarian cancer. STUDY DESIGN: We performed a micro-cost analysis comparing laparoscopic tubal coagulation, tubal clips and bilateral salpingectomies at the Michael Garron Hospital, formerly the Toronto East General Hospital, from 2015 to 2016. A Markov model was used in the cost-effectiveness and cost-utility analyses on these surgical procedures in ovarian cancer prevention. Costs were derived for the number ovarian cancer cases observed per sterilization method, cancer treatment, and associated procedural costs over each cancer patient's lifetime. The number of bilateral salpingectomies required to prevent an additional ovarian cancer case with the recommended treatment was also estimated. RESULTS: Bilateral salpingectomies performed at the Michael Garron Hospital generated savings of $7823 per life-year gained (95% CI $3248-$10 190; incremental cost [ΔC] -$907, incremental effect [ΔE] 0.11 life-years gained) compared with tubal clips and savings of $6315 per life-year gained (95% CI -$6360 to $9342; ΔC -$755, ΔE 0.11 life-years gained) compared with tubal coagulation. Most importantly, for every 150 bilateral salpingectomies performed, one case of ovarian cancer may be prevented. CONCLUSION: Laparoscopic bilateral salpingectomy is the dominant, cost-effective surgical strategy when compared to tubal clips and tubal coagulation to prevent ovarian cancer. Laparoscopic bilateral salpingectomies reduce costs and enhance quality-adjusted life-years relative to the two alternative treatments.


Assuntos
Serviços de Planejamento Familiar/normas , Neoplasias Ovarianas/prevenção & controle , Procedimentos Cirúrgicos Profiláticos/economia , Salpingectomia/economia , Esterilização Tubária/economia , Análise Custo-Benefício , Feminino , Humanos , Modelos Econômicos , Neoplasias Ovarianas/economia , Gravidez , Gravidez Ectópica/economia , Gravidez Ectópica/etiologia , Esterilização Tubária/efeitos adversos , Esterilização Tubária/métodos
2.
Sci Rep ; 7(1): 6133, 2017 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-28733663

RESUMO

Topological materials with exotic quantum properties are promising candidates for quantum spin electronics. Different classes of topological materials, including Weyl semimetal, topological superconductor, topological insulator and Axion insulator, etc., can be connected to each other via quantum phase transition. For example, it is believed that a trivial band insulator can be twisted into topological phase by increasing spin-orbital coupling or changing the parameters of crystal lattice. With the results of LDA calculation and measurement by angle-resolved photoemission spectroscopy (ARPES), we demonstrate in this work that the electronic structure of SrSn2As2 single crystal has the texture of band inversion near the critical point. The results indicate the possibility of realizing topological quantum phase transition in SrSn2As2 single crystal and obtaining different exotic quantum states.

3.
Nanotechnology ; 28(8): 085203, 2017 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-28054513

RESUMO

We develop reflective color filters with randomly distributed nanodisks and nanoholes fabricated with hydrogen silsesquioxane and Ag films on silicon substrate. They exhibit high resolution, angle-independence and easily up-scalable fabrication, which are the most important factors for color filters for industrial applications. We uncover the underlying mechanism after systematically analyzing the localized surface plasmon polariton coupling in the electric-field distribution. The agreement of the experimental results with those from the simulation indicates that tunable colors across the visible spectrum can be obtained by simply varying the diameter of the nanodisks, promoting their applications.

4.
Appl Opt ; 55(1): 148-52, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26835634

RESUMO

We demonstrate a TE/TM polarization-independent plasmonic subtractive color filtering scheme employing ultrathin two-dimensional Ag nanodisks. These TE/TM polarization-independent subtractive color filters exhibit small feature sizes (below 200 nm) and high transmission up to 70% in the visible spectral region, superior to previously reported plasmonic color filters. Simulated optical transmission spectra and colors are in good agreement with experimental results. The color-filtering behaviors strongly depend on thickness and period of nanodisks. Underlying mechanisms are also discussed in detail.

5.
Aust N Z J Psychiatry ; 50(6): 566-76, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26494850

RESUMO

OBJECTIVE: Previous research suggests that New Zealand Maori may have an elevated rate of schizophrenia. However, there is limited evidence on important clinical features of the illness in this population. This study examined cognitive neuropsychological functioning in 54 adult Maori diagnosed with schizophrenia and 56 Maori controls. This study also examined associations between cognition, medication and symptoms of psychosis in the schizophrenia group. METHOD: The groups were matched on socio-demographic variables, handedness and premorbid cognitive ability. Participants were assessed on neuropsychological tests of attention, executive ability, motor, premorbid ability, verbal/non-verbal memory and verbal fluency (English/Maori versions). The Positive and Negative Syndrome Scale was used to assess psychotic symptoms. Information on cultural identity, duration of illness, duration of untreated psychosis, medication and substance abuse was collected. RESULTS: The performance of the schizophrenia group was significantly lower than the control group on all the neuropsychological tests, except the test of attention. The effect sizes were moderate to large: 0.78 for motor function; 1.3 for executive ability, verbal fluency and visual memory; 1.6 for verbal learning and 1.8 for verbal memory. These differences remained after adjustment for multiple comparisons and covariates. A higher dose of antipsychotic medication and a higher anticholinergic load were associated with greater verbal memory impairment (r = -0.38 and r = -0.38, respectively). A longer duration of illness was associated with greater impairment of verbal memory (rho = -0.48), verbal learning (rho = -0.41) and visual memory (rho = -0.44). CONCLUSION: The findings for the schizophrenia group show a profile of generalised cognitive impairment with greater impairment of verbal memory. The cognitive impairment in this group was independent of psychotic symptoms, but was associated with a higher antipsychotic dose, higher anticholinergic load and longer duration of illness. These findings have implications for clinical prescribing practices and rehabilitation for New Zealand Maori diagnosed with schizophrenia.


Assuntos
Atenção , Transtornos Cognitivos/diagnóstico , Cognição , Esquizofrenia/etnologia , Esquizofrenia/reabilitação , Aprendizagem Verbal , Adulto , Antipsicóticos/efeitos adversos , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Nova Zelândia , Escalas de Graduação Psiquiátrica , Psicologia do Esquizofrênico , Adulto Jovem
6.
J Nutr Health Aging ; 19(10): 986-93, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26624209

RESUMO

OBJECTIVES: Fluid imbalance due to sodium retention and malnutrition can be characterized by the ratio of extracellular water (ECW) to intracellular water (ICW). We investigated whether the ECW/ICW ratio is a risk factor for adverse outcomes. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: 149 patients with chronic kidney disease from 2005 to 2009, who were followed until August 2013. MEASUREMENTS: Body fluid composition was measured by bioelectrical impedance analysis. Patients were categorized according to the ECW/ICW ratio tertile. Daily nutrient intake was estimated from 24-h dietary recall and analyzed using standard food composition tables. The main outcomes were adverse renal outcomes, as defined by a decline of 50% or more from the baseline glomerular filtration rate or initiation of renal replacement therapy, cardiovascular events, and all-cause mortality. RESULTS: The ECW/ICW ratio increased with downward ICW slope with age and renal dysfunction besides ECW excess with massive proteinuria. Sodium intake, protein intake, and calorie intake were negatively correlated with the ECW/ICW ratios due to the steeper decreasing ICW content with the decreased dietary intake than the decreasing ECW content. During a median 4.9-year follow up, patients in the highest tertile had the worst adverse renal outcomes (15.9 vs. 5.1 per 100 patient-years, P < 0.001), cardiovascular events (4.1 vs. 0.3 per 100 patient-years, P = 0.002), and mortality (11.2 vs. 1.3 per 100 patient-years, P < 0.001). The adjusted hazard ratio (95% confidence intervals) for adverse renal outcomes, cardiovascular events, and mortality were 1.15 (1.03 - 1.26), 1.12 (0.93 - 1.31), and 1.29 (1.11 - 1.50), respectively. CONCLUSIONS: Fluid imbalance between ICW and ECW occurring in malnourished and elderly patients with chronic kidney disease may explain the reserve capacity for volume overload and is associated with adverse renal outcomes and all-cause mortality.


Assuntos
Envelhecimento/fisiologia , Composição Corporal , Água Corporal/metabolismo , Desnutrição/complicações , Insuficiência Renal Crônica/complicações , Desequilíbrio Hidroeletrolítico/etiologia , Água/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/etiologia , Estudos de Coortes , Dieta , Impedância Elétrica , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Desnutrição/metabolismo , Desnutrição/mortalidade , Pessoa de Meia-Idade , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/mortalidade , Insuficiência Renal Crônica/fisiopatologia , Estudos Retrospectivos , Sódio/metabolismo , Desequilíbrio Hidroeletrolítico/metabolismo
7.
Nanoscale ; 7(37): 15487-94, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26274048

RESUMO

Here we present an in-depth and comprehensive study of the effect of the geometry and morphology of nanoarray (NA) substrates on their surface-enhanced Raman scattering (SERS) performance. The high-quality SERS-active NA substrates of various unit shapes and pitches are assembled through electron beam lithography and fabricated by electron beam physical vapor deposition. Good agreement is found on comparing the Raman scattering results with the integrals of the fourth power of local electric fields from the three-dimensional numerical simulations. A novel type of hybrid NA substrate composed of disordered nanoparticles and a periodic NA is fabricated and characterized. The morphology of NAs has little influence on the SERS performance of hybrid NA substrates and they perform better than both their counterparts pure NA and disordered nanoparticle substrates.

8.
Nanotechnology ; 26(30): 305204, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-26160906

RESUMO

Plasmonic subtractive color filters through patterning periodic nanostructures on ultrathin Ag films deposited on a glass substrate, exhibiting good durability, simple fabrication, and flexible color tunability, have attracted considerable attention due to their tremendous potential applications. While previous studies have mainly focused on their extraordinary physical mechanisms, color purity, which is another key parameter for high quality imaging applications, has been much less investigated. In this work, we demonstrate that the relative position of nanoholes patterned on ultrathin Ag films can largely affect the color purity of plasmonic subtractive color filters. The calculated results agree reasonably well with the experimental data, revealing that the purity of subtractive colors can be improved by changing the nanohole arrays from square lattice to triangular lattice without reducing transmission at visible frequencies. In addition, underlying mechanisms are clarified by systematically analyzing the dominant valley in transmission spectra.

9.
Br J Radiol ; 88(1052): 20140861, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25989696

RESUMO

OBJECTIVE: To determine if there is a difference in post-transplant lymphoproliferative disorder (PTLD) in adults after solid organ transplantation (SOT) and haematologic stem cell transplantation (HST). METHODS: In this institutional review board-approved Health Insurance Portability and Accountability Act-compliant study, we reviewed clinical data and imaging at the time of diagnosis in 41 patients (26 SOT and 15 HST) (31 males and 10 females; mean age 51 years) with histopathology-confirmed PTLD seen at our institution from 2004 through 2013. Statistical analysis was performed to assess difference in distribution and survival between SOT and HST cohorts. RESULTS: SOT: 17 lung/cardiac, 8 renal and 1 liver transplant recipients. HST: 13 leukaemia/lymphoma and 2 patients with aplastic anaemia. Median time to diagnosis: SOT 3.0 years; HST 6 months (Fisher's exact test; p = 0.0011). There was no statistically significant difference in distribution of PTLD after SOT and HST with nodes (15/26; 8/15), lung (10/26; 5/15) and bowel (6/26; 4/15) being the most common sites. Hepatic (3/26) and neurologic (2/26) involvement occurred in only SOT cohort while splenic PTLD (5/15) occurred more often in HST cohort. Death occurred earlier in HST (9/15; 2 weeks) than SOT cohort (12/26; 11 months) (Wilcoxon test; p = 0.0188). CONCLUSION: PTLD did not differ significantly in distribution between SOT and HST cohorts. PTLD after HST occurred early and had shorter survival. ADVANCES IN KNOWLEDGE: The most common sites of PTLD were the nodes, lung and bowel. Distribution of PTLD does not differ significantly between patients with SOT and HST. PTLD after HST occurs early and has poor survival compared with PTLD after SOT.


Assuntos
Doenças Hematológicas/cirurgia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transtornos Linfoproliferativos/etiologia , Transplante de Órgãos/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Citomegalovirus/diagnóstico , Infecções por Vírus Epstein-Barr/diagnóstico , Feminino , Doenças Hematológicas/patologia , Humanos , Transtornos Linfoproliferativos/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
10.
Laryngoscope ; 125(2): 389-95, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25093527

RESUMO

OBJECTIVES/HYPOTHESIS: The aim of this study was to quantitatively investigate spatiotemporal movement abnormalities during the pharyngeal phase of swallowing in individuals with Parkinson's disease (PD) and to investigate relationships between disease and dysphagia severities. STUDY DESIGN: Retrospective study. METHODS: We performed two-dimensional motion analysis of the hyoid bone, epiglottis, and vocal folds using videofluoroscopic images from 33 PD patients and 33 age-matched, healthy controls. The outcome measures were spatial and temporal movement variables during swallowing. Additionally, three subgroups of patients were compared based on the Hoehn and Yahr scale to identify the relationship between disease and dysphagia severities. RESULTS: Individuals with PD showed a reduced anterior hyoid bone displacement after normalization for each individual. The maximal angle of the epiglottic rotation was smaller in PD patients. The time to maximal displacement of the hyoid bone, epiglottis, and vocal folds were significantly delayed in PD patients (P = 0.001, 0.002, and < 0.001, respectively); the mean velocities of the hyoid bone and epiglottic movements were also reduced in PD patients (P < 0.001 and < 0.001, respectively). The velocity curves of the hyoid bone revealed more peaks in individuals with PD, representing incoordination during swallowing. Clinical disease severity was related to level of diet and supervision but not with dysphagia severity. CONCLUSION: This study shows that oropharyngeal bradykinesia, incoordination, reduced anterior hyoid bone movement, and decreased epiglottic rotation angle during swallowing are the most noticeable findings in individuals with PD. LEVEL OF EVIDENCE: N/A.


Assuntos
Transtornos de Deglutição/fisiopatologia , Doença de Parkinson/fisiopatologia , Idoso , Epiglote/fisiopatologia , Feminino , Humanos , Osso Hioide/fisiopatologia , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Prega Vocal/fisiopatologia
11.
J Synchrotron Radiat ; 21(Pt 1): 273-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24365949

RESUMO

A new ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline has been designed and is under construction at the Shanghai Synchrotron Radiation Facility. The beamline has two branches: one dedicated to angle-resolved photoemission spectroscopy (ARPES) and the other to photoelectron emission microscopy (PEEM). The two branches share the same plane-grating monochromator, which is equipped with four variable-line-spacing gratings and covers the 20-2000 eV energy range. Two elliptically polarized undulators are employed to provide photons with variable polarization, linear in every inclination and circular. The expected energy resolution is approximately 10 meV at 1000 eV with a flux of more than 3 × 10(10) photons s(-1) at the ARPES sample positions. The refocusing of both branches is based on Kirkpatrick-Baez pairs. The expected spot sizes when using a 10 µm exit slit are 15 µm × 5 µm (horizontal × vertical FWHM) at the ARPES station and 10 µm × 5 µm (horizontal × vertical FWHM) at the PEEM station. The use of plane optical elements upstream of the exit slit, a variable-line-spacing grating and a pre-mirror in the monochromator that allows the influence of the thermal deformation to be eliminated are essential for achieving the ultrahigh-energy resolution.

12.
Int J STD AIDS ; 22(1): 30-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21364064

RESUMO

This research aimed to determine HIV prevalence, risk behaviour and knowledge of transmission methods among men who have sex with men (MSM) in Kuala Lumpur, Malaysia. Venue-day-time sampling (VDTS) was applied to identify venues where men congregate to solicit sex from other men. Participants recruited from clubs, massage parlours, saunas and one park self-completed a computerized behavioural questionnaire, were administered an oral rapid HIV test and given the opportunity to return later to receive full counselling and learn their HIV status. A total of 517 men were enrolled into the study. The majority were Malays (47.0%) and Chinese (43.7%). Twenty tested HIV positive (3.9%). Significant predictors of HIV infection included having unprotected anal sex with a casual partner (44.9% of participants, odds ratio [OR] = 2.99; 95% confidence interval [CI] 1.13-7.90; P = 0.027), having unprotected receptive anal sex (27.9%, OR = 2.71; 95% CI 1.10-6.54; P = 0.030) and having group sex (33.3%, OR = 3.95; 95% CI 1.55-10.09; P = 0.004). One in five participants (20.1% and 19.5%) did not believe that HIV could be transmitted through insertive or receptive anal sex, respectively. Risk behaviour is high and knowledge of HIV transmission methods was low among MSM in Kuala Lumpur. Future prevention efforts should focus on providing risk reduction education to this community.


Assuntos
Infecções por HIV/epidemiologia , Homossexualidade Masculina , Assunção de Riscos , Adolescente , Adulto , Etnicidade , Infecções por HIV/diagnóstico , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Inquéritos e Questionários , Adulto Jovem
13.
J Synchrotron Radiat ; 17(6): 804-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20975228

RESUMO

The detection of chemical mapping with a spatial resolution of 30 nm has been achieved with a scanning transmission X-ray microscope at the Shanghai Synchrotron Radiation Facility. For each specimen, two absorption images were scanned separately with energies E(1) and E(2): E(1) was focused on the absorption edge of the chosen element and E(2) was focused below the edge. A K-edge division method is proposed and applied to obtain the element mapping. Compared with the frequently used K-edge subtraction method, this ratio-contrast method is shown to be more accurate and sensitive in identifying the elements of interest, where the definition of the contrast threshold is simple and clear in physics. Several examples are presented to illustrate the effectiveness of the method.


Assuntos
Microscopia Eletrônica de Transmissão e Varredura/métodos , Feminino , Humanos , Síncrotrons , Neoplasias do Colo do Útero/ultraestrutura , Raios X
14.
Phys Rev Lett ; 103(19): 197401, 2009 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-20365953

RESUMO

We have developed a new method to investigate the relaxation time of the dipole moment in polarization clusters in BaTiO3. Time correlation of speckle intensities was measured by the use of a double pulsed soft x-ray laser. The evolution of the relaxation time of the dipole moment near the Curie temperature (T(C)) was investigated. The maximum relaxation time (approximately 90 ps) is shown to appear at a temperature of 4.5 K above the T(C), being coincident with the one where the maximum polarization takes place. This method is widely applicable to any other critical decay processes at phase transitions.

15.
Aust N Z J Psychiatry ; 42(11): 941-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18941958

RESUMO

OBJECTIVE: The aim of the present study was to estimate the 12 month prevalence of schizophrenia in the Maori population of New Zealand. METHOD: Mental health data from two national sources were obtained for the period 2000-2003. A simple count of unique individuals with schizophrenia was used to estimate contact prevalence and a four-list capture-recapture procedure to estimate population prevalence. RESULTS: Contact prevalence was significantly lower than the estimated population prevalence for both groups. The estimated 12 month prevalence of schizophrenia for Maori (0.97%) was significantly higher than for non-Maori (0.32%), even after adjustment for age, case under-ascertainment, and socioeconomic deprivation. CONCLUSIONS: The prevalence of schizophrenia among Maori appears to be elevated, although limitations in diagnostic reliability and recording of ethnicity must be considered. This adds further evidence of worldwide variation in the prevalence of schizophrenia. Capture-recapture provides a reliable cost-effective alternative to epidemiological surveys for estimating the prevalence of low-prevalence disorders such as schizophrenia.


Assuntos
Etnicidade/psicologia , Etnicidade/estatística & dados numéricos , Esquizofrenia/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Viés , Estudos Transversais , Bases de Dados Factuais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Alta do Paciente/estatística & dados numéricos , Carência Psicossocial , Esquizofrenia/diagnóstico , Fatores Sexuais , Adulto Jovem
16.
Biosystems ; 77(1-3): 195-212, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15527957

RESUMO

Previous studies of antibody binding domains have established many crucial features that include important structural positions, canonical formations, and the geometric correlations with the binding site nature and topography. In this work, position-specific frequency and hierarchical clustering analysis are used to explore the statistical pattern of the residues in the complementarity determining regions of human antibodies. In addition, Shannon's information entropy is computed for the entire heavy and light chains and compared with germline patterns to seek variability due to antibody clonal selection. Results are compared with reported analyses based on structural data and ligand-protein contact point computations based on Protein Data Bank records. Observations derived from the present sequence analysis are consistent with previous structural based methods. In the absence of structural data, methods used in this work can be effective and efficient computational tools used for identifying residues that are important for antigen targeting and predicting the probable amino acid distribution expected at these positions. The results in turn can be applied to help design or plan mutagenesis experiments to improve the binding properties of antibodies.


Assuntos
Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/imunologia , Imunoglobulinas/química , Imunoglobulinas/imunologia , Modelos Químicos , Modelos Imunológicos , Análise de Sequência de Proteína/métodos , Sequência de Aminoácidos , Complexo Antígeno-Anticorpo/análise , Complexo Antígeno-Anticorpo/química , Análise por Conglomerados , Biologia Computacional/métodos , Entropia , Dados de Sequência Molecular , Mapeamento de Interação de Proteínas/métodos , Relação Estrutura-Atividade
17.
Phys Rev Lett ; 93(8): 087601, 2004 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-15447225

RESUMO

The polarization clusters existing in both the ferroelectric and the paraelectric phase of BaTiO3 are directly observed and characterized for the first time by a picosecond soft x-ray laser speckle technique. These dynamic clusters appear continuously across the Curie temperature T(c). The clusters' distance increases approximately linearly with temperature, while their mean size does not change significantly. The polarization exhibits a maximum at a temperature about 5 degrees C above T(c). The clusters' short-range correlation strength diverges as (T-T(c))(-0.41+/-0.02) as temperature decreases toward T(c).

18.
Phys Rev Lett ; 89(25): 257602, 2002 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-12484921

RESUMO

A picosecond x-ray laser speckle has been conducted to study the dynamics of a disordered surface domain structure (BaTiO3 with 90 degrees c/a domains) as a function of temperature for the first time. The transient surface structures induced by ferroelectric domains decrease as temperature increases towards the Curie temperature T(c) and completely disappear above T(c). The dramatic change of the spatial configuration of the c/a domains was observed to occur from a temperature 2 degrees C below T(c), near which the average correlated domain size at equilibrium decreases as (T(c)-T)(0.37+/-0.02).

19.
J Dairy Sci ; 85(6): 1398-405, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12146470

RESUMO

Conception in dairy cows during autumn remains low even after summer temperatures decline. This is possibly a residual effect of heat stress on oocyte quality. Lactating Holsteins previously heat-stressed during summer were used in two experiments (n = 8 and 16 cows) in autumn to examine hormonal strategies for improving quality of oocytes. Follicles (3 to 8 mm in diameter) were aspirated by the ovum pick-up procedure on d 4 of two consecutive estrous cycles of treated and control cows. Oocytes were classified morphologically, matured in vitro, chemically activated, and cultured for 8 d. In Experiment 1, FSH (2 x 200 mg, at a 12-h interval) was injected on d 5 and 12 of cycle 1 (treated cycle). Before FSH, the percentage of good quality oocytes (grade I) and the cleavage rate averaged 52 and 24%, respectively, in both groups. During the FSH-treated cycle, more 6- to 9-mm follicles were observed. In the subsequent cycle, rates of grade I oocytes and cleavage were significantly higher in FSH-treated than in control cows (89 vs. 51% and 85 vs. 31%, respectively). In Experiment 2, recombinant bovine somatotropin (bST, 500 mg) was injected on d 4 and 18 of the treated cycle. The bST treatment increased the number of 3- to 5-mm follicles. Before bST, grade I (39%) and cleaved oocytes (40%), were similar across treatment groups. In the subsequent cycle, the percentage of grade I oocytes was significantly higher in treated than in control cows (72 vs. 26%), but cleavage rates were similar. Neither FSH or bST improved blastocyst formation, and regardless of treatment, few blastocysts were formed. Treatment with bST improved oocyte morphology, whereas FSH improved both oocyte morphology and cleavage rates during autumn following summer heat stress.


Assuntos
Bovinos/fisiologia , Fertilidade/fisiologia , Hormônio Foliculoestimulante/farmacologia , Hormônio do Crescimento/farmacologia , Temperatura Alta/efeitos adversos , Oócitos/fisiologia , Animais , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/fisiopatologia , Desenvolvimento Embrionário e Fetal , Feminino , Fertilidade/efeitos dos fármacos , Hormônio Foliculoestimulante/sangue , Transtornos de Estresse por Calor/tratamento farmacológico , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/veterinária , Oócitos/efeitos dos fármacos , Folículo Ovariano/citologia , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/fisiologia , Distribuição Aleatória , Estações do Ano , Sucção , Fatores de Tempo
20.
Ann Fr Anesth Reanim ; 18(7): 783-6, 1999 Aug.
Artigo em Francês | MEDLINE | ID: mdl-10486632

RESUMO

Following a normal delivery, a 22-year-old primigravida experienced fever resistant to antibiotic therapy. On the tenth post partum day, thoracic pain and chest X-ray were in favour of acute pneumonitis of left inferior lobe. Considering the extension to the right lung and a normal bronchic fibrescopy, a computed tomography (CT) was performed which showed a right ovarian vein thrombophlebitis, right minor subpleural opacities and left pneumopathy. The final diagnosis was post partum ovarian vein suppurated thrombophlebitis with pulmonary septic metastases from haematogenic diffusion. Post partum thrombophlebitis is a rare event with an incidence of 1 per 2,000 deliveries. Pulmonary inaugurating symptoms result rather from pulmonary embolism than from septic metastases. Post partum persisting and unexplained fever should be explored with abdominal CT-scan.


Assuntos
Pneumopatias/etiologia , Ovário/irrigação sanguínea , Doenças Pleurais/etiologia , Período Pós-Parto , Tromboflebite/etiologia , Adulto , Feminino , Humanos , Pneumopatias/diagnóstico , Pneumopatias/diagnóstico por imagem , Doenças Pleurais/diagnóstico , Doenças Pleurais/diagnóstico por imagem , Fluxo Sanguíneo Regional/fisiologia , Tromboflebite/diagnóstico , Tromboflebite/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Veias/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA