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1.
Neurobiol Dis ; 127: 114-130, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30763678

RESUMO

Parkinson's disease (PD) is the second most frequent neurodegenerative disorder in the old population. Among its monogenic variants, a frequent cause is a mutation in the Parkin gene (Prkn). Deficient function of Parkin triggers ubiquitous mitochondrial dysfunction and inflammation in the brain, but it remains unclear how selective neural circuits become vulnerable and finally undergo atrophy. We attempted to go beyond previous work, mostly done in peripheral tumor cells, which identified protein targets of Parkin activity, an ubiquitin E3 ligase. Thus, we now used aged Parkin-knockout (KO) mouse brain for a global quantification of ubiquitylated peptides by mass spectrometry (MS). This approach confirmed the most abundant substrate to be VDAC3, a mitochondrial outer membrane porin that modulates calcium flux, while uncovering also >3-fold dysregulations for neuron-specific factors. Ubiquitylation decreases were prominent for Hippocalcin (HPCA), Calmodulin (CALM1/CALML3), Pyruvate Kinase (PKM2), sodium/potassium-transporting ATPases (ATP1A1/2/3/4), the Rab27A-GTPase activating protein alpha (TBC1D10A) and an ubiquitin ligase adapter (DDB1), while strong increases occurred for calcium transporter ATP2C1 and G-protein subunits G(i)/G(o)/G(Tr). Quantitative immunoblots validated elevated abundance for the electrogenic pump ATP1A2, for HPCA as neuron-specific calcium sensor, which stimulates guanylate cyclases and modifies axonal slow afterhyperpolarization (sAHP), and for the calcium-sensing G-protein GNA11. We assessed if compensatory molecular regulations become insufficient over time, leading to functional deficits. Patch clamp experiments in acute Parkin-KO brain slices indeed revealed alterations of the electrophysiological properties in aged noradrenergic locus coeruleus (LC) neurons. LC neurons of aged Parkin-KO brain showed an acceleration of the spontaneous pacemaker frequency, a reduction in sAHP and shortening of action potential duration, without modulation of KCNQ potassium currents. These findings indicate altered calcium-dependent excitability in a PARK2 model of PD, mediated by diminished turnover of potential Parkin targets such as ATP1A2 and HPCA. The data also identified further novel Parkin substrate candidates like SIRT2, OTUD7B and CUL5. Our elucidation of neuron-specific mechanisms of PD pathogenesis helps to explain the known exceptional susceptibility of noradrenergic and dopaminergic projections to alterations of calcium homeostasis and its mitochondrial buffering.


Assuntos
Neurônios Adrenérgicos/metabolismo , Encéfalo/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Hipocalcina/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Espectrometria de Massas , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Técnicas de Patch-Clamp , Ubiquitina-Proteína Ligases/genética , Canais de Ânion Dependentes de Voltagem/metabolismo
2.
Clin Transl Imaging ; 2(5): 427-437, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25379506

RESUMO

Malignancies of the lungs, both primary and metastatic, are the leading cause of death worldwide. Over 1.5 million new cases of primary lung cancer are diagnosed annually worldwide with a dismal five-year survival rate of approximately 15%, which remains unchanged despite major efforts and medical advances. As expected, survival for patients with lung metastases is even worse at about 5%. Early detection and staging are fundamental in improving survival rates and selecting the most effective treatment strategies. Recently, nanoparticles have been developed for imaging and treating various cancers, including pulmonary malignancies. In this work, three different examples of nanoparticle configurations for cancer theranosis are presented, namely conventional spherical polymeric nanoparticles with a diameter of ~ 150 nm; and discoidal mesoporous silicon nanoconstructs and discoidal polymeric nanoconstructs with a diameter of ~ 1,000 nm and a height of 400 and 500 nm, respectively. The spherical nanoparticles accumulate in tumors by means of the well-known enhanced permeation and retention effect, whereas sub-micrometer discoidal nanoconstructs are rationally designed to adhere firmly to the tortuous tumor vasculature. All three nanoparticles are characterized for their in vivo performance in terms of magnetic resonance, positron-emission tomography (PET), and optical imaging. Preliminary data on the in vivo and ex vivo PET/CT imaging of breast cancer metastasis in the lungs using discoidal nanoconstructs is presented. In conclusion, opportunities for nanoparticle-based theranosis in primary lung cancer and pulmonary metastasis are presented and discussed.

3.
J Craniofac Surg ; 24(1): 163-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23348277

RESUMO

OBJECTIVE: To compare the removal rates of 8-hole angle strut plate and Champy line plate in repairing mandibular angle fractures. METHODS: Retrospective chart review at a tertiary care academic center of adults who were at least 18 years old with at least 1 mandibular angle fracture of a traumatic origin who underwent open reduction and internal fixation by using single monocortical miniplate fixation in Champy line or by using 8-hole angle strut plate via transbuccal approach. The outcome measures were hardware removal rates and the reason for removal of the hardware. RESULTS: One hundred four patients with a total of 106 angle fractures met the inclusion criteria for this study. Seventy-three angle fractures were treated with the 8-hole strut, and 33 angle fractures were treated with the Champy line plates. There were 6 plates removed in both groups. This resulted in 8.2% of plates removed in the 8-hole strut plate group and 18.2% in the Champy line group (P = 0.133). Loose hardware was determined to be the cause of plate removal in 2 (2.7%) of the 8-hole strut plate group compared with all 6 (18.2%) of the Champy group (P = 0.005). CONCLUSIONS: Overall, removal rates between Champy line and 8-hole strut plates are not different in treating mandibular angle fractures, although the 8-hole strut plate has a lower rate of loose hardware-related plate removal compared with the Champy line plate.


Assuntos
Placas Ósseas , Remoção de Dispositivo , Fixação Interna de Fraturas/instrumentação , Fraturas Mandibulares/cirurgia , Adulto , Feminino , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento
4.
Arch Otolaryngol Head Neck Surg ; 138(4): 367-71, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22431859

RESUMO

OBJECTIVE: To determine the factors contributing to failure of interpolation flaps in nasal reconstruction. DESIGN: Retrospective medical chart review. SETTING: Tertiary care academic center. PATIENTS: A total of 107 patients with nasal defects needing reconstruction, performed at the University of Arkansas for Medical Sciences, Little Rock. INTERVENTION: Patients underwent nasal reconstruction with 2-stage paramedian forehead or nasolabial flaps (PMFF and NLF, respectively) from 2002 to 2011. Defect thickness, location, flap type, use of cartilage grafts, and comorbidities, including diabetes mellitus, peripheral vascular or coronary artery disease, and smoking habits, were recorded. MAIN OUTCOME MEASURES: Full success, partial failure, or full failure of the respective flap. RESULTS: Eighty-two of the patients (77%) underwent 2-stage PMFF repair and 25 (23%) underwent 2-stage NLF repair. Fifty-eight defects (54%) were full thickness, in which 46 repairs used PMFF and 12 used NLF for reconstruction. The overall failure rate was 6%. Five PMFF failed (6%); 3 of these were used for full-thickness repairs. There was only 1 NLF failure (4%), which was also performed for the repair of a full-thickness defect. Use of cartilage in the reconstruction did not affect failure rates of the different soft tissue flaps. No single comorbidity was noted to have a statistically significant effect on failure rates, although 83% of failures were observed in smokers. CONCLUSIONS: The overall success rate of interpolation flaps in nasal reconstruction was 94.4%. Defect thickness, use of a cartilage graft, type of flap used, and presence of comorbidities did not affect outcome. Although the comparison was not statistically significant (P  = .21), flap failures were more commonly observed in smokers.


Assuntos
Testa/cirurgia , Sobrevivência de Enxerto , Nariz/cirurgia , Rinoplastia/métodos , Retalhos Cirúrgicos , Idoso , Idoso de 80 Anos ou mais , Arkansas , Cartilagem/transplante , Distribuição de Qui-Quadrado , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Risco , Retalhos Cirúrgicos/irrigação sanguínea , Resultado do Tratamento
5.
Hum Reprod ; 24(8): 1999-2006, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19429909

RESUMO

BACKGROUND: It is plausible that a couple's ability to achieve the desired number of children is limited by biological fertility, especially if childbearing is postponed. Family size has declined and semen quality may have deteriorated in much of Europe, although studies have found an increase rather than a decrease in couple fertility. METHODS: Using four high-quality European datasets, we took the reported time to pregnancy (TTP) as the predictor variable; births reported as following contraceptive failure were an additional category. The outcome variable was final or near-final family size. Potential confounders were maternal age when unprotected sex began prior to the first birth, and maternal smoking. Desired family size was available in only one of the datasets. RESULTS: Couples with a TTP of at least 12 months tended to have smaller families, with odds ratios for the risk of not having a second child approximately 1.8, and for the risk of not having a third child approximately 1.6. Below 12 months no association was observed. Findings were generally consistent across datasets. There was also a more than 2-fold risk of not achieving the desired family size if TTP was 12 months or more for the first child. CONCLUSIONS: Within the limits of the available data quality, family size appears to be predicted by biological fertility, even after adjustment for maternal age, if the woman was at least 20 years old when the couple's first attempt at conception started. The contribution of behavioural factors to this result also needs to be investigated.


Assuntos
Características da Família , Fertilidade/fisiologia , Comportamento Contraceptivo , Feminino , Humanos , Masculino , Idade Materna , Modelos Estatísticos , Gravidez , Fumar/efeitos adversos
6.
Otolaryngol Head Neck Surg ; 140(6): 845-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19467401

RESUMO

OBJECTIVE: To determine whether the presence of a tooth in the line of mandibular angle fracture increases the incidence of complications and whether removing these teeth has an effect on complication rates. DESIGN: Case series with chart review. SUBJECTS AND METHODS: The analysis was performed on 83 patients who underwent open reduction and internal fixation for mandibular angle fractures. Lower molar teeth involved in the fracture line were extracted if they were loose, fractured, or grossly infected or prevented satisfactory reduction. Data regarding demographics, involvement of a molar tooth, management of the involved tooth, and postoperative outcome were analyzed. Statistical analysis was performed by using likelihood ratio chi(2) and logistic regression. RESULTS: The revision surgery in fractures with molar tooth involvement was 28.9 percent, compared to 12.9 percent when no tooth was involved (P = 0.084). When a tooth was involved in the fracture, the revision surgery rate was 25 percent when it was removed and 30% when it was preserved (P = 0.734). CONCLUSION: Postoperative complications, especially the revision surgery rates, may not increase by involvement of lower molar teeth in the fracture line and selective removal of these teeth by using commonly accepted guidelines may not decrease complication rates in angle fractures.


Assuntos
Fixação Interna de Fraturas/métodos , Fraturas Mandibulares/cirurgia , Dente Molar , Adolescente , Adulto , Distribuição de Qui-Quadrado , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Dente Molar/cirurgia , Complicações Pós-Operatórias , Reoperação , Estudos Retrospectivos , Extração Dentária , Resultado do Tratamento
7.
Otolaryngol Head Neck Surg ; 138(4): 528-30, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18359367

RESUMO

OBJECTIVE: To report the occlusal outcomes of manually provided temporary intraoperative maxillomandibular fixation (MMMF) for the open repair of selected mandibular fractures. STUDY DESIGN/SUBJECTS AND METHODS: A retrospective chart review of the patients who underwent open reduction and internal fixation of mandibular fractures with MMMF was performed. RESULTS: Twenty-six patients underwent open reduction and internal fixation with MMMF. Postoperative data were available for only 16 patients who kept their follow-up appointments. With the exception of one patient who experienced minimal cross-bite in the right molar region, all of the patients had their original normocclusion. CONCLUSION: Preliminary results of MMMF suggest that satisfactory postoperative occlusal outcomes may be obtained without the use of wire-based maxillomandibular fixation methods in selected mandibular fractures.


Assuntos
Fixação Interna de Fraturas/métodos , Fraturas Mandibulares/cirurgia , Adolescente , Adulto , Fios Ortopédicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Science ; 310(5748): 657-60, 2005 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-16179434

RESUMO

A major challenge in predicting Earth's future climate state is to understand feedbacks that alter greenhouse-gas forcing. Here we synthesize field data from arctic Alaska, showing that terrestrial changes in summer albedo contribute substantially to recent high-latitude warming trends. Pronounced terrestrial summer warming in arctic Alaska correlates with a lengthening of the snow-free season that has increased atmospheric heating locally by about 3 watts per square meter per decade (similar in magnitude to the regional heating expected over multiple decades from a doubling of atmospheric CO2). The continuation of current trends in shrub and tree expansion could further amplify this atmospheric heating by two to seven times.


Assuntos
Efeito Estufa , Alaska , Regiões Árticas , Picea , Estações do Ano , Árvores
11.
Hereditas ; 141(2): 166-79, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15660977

RESUMO

The resistance of barley (Hordeum vulgare L.) to Rhynchosporium secalis (scald) has been investigated in two crosses between the susceptible cv. 'Ingrid' and two resistant Ethiopian landraces, 'Steudelli' and 'Jet'. Doubled haploids were inoculated in replicated tests using two isolates of R. secalis, '4004' and 'WRS1872'. Expression of resistance differed widely between replicated tests. AFLP, SSR and RFLP markers were used to develop chromosome maps. Results have been analysed using partial least squares regression (PLSR) and interval mapping. In PLSR the major covariance structures or 'latent variables' between X (markers) and Y (isolates, tests) are modelled as principal components and their optimal number determined by cross-validation. In 'Steudelli' two QTL were detected, one on each of chromosomes 3H and 7H, in 4 out of 5 tests, while in 'Jet' only one (different) allele at the 3H locus was found. The validated R(2) varied between 11.0% and 64.9% in the replicated tests with '4004'.With isolate 'WRS1872' the 7H locus and another 3H locus were detected. By interval mapping the QTL detected were less stable and generally gave lower R(2) values than PLSR. PLSR does not depend on maps, but interval mapping based on values predicted by PLSR had R(2) around 90%. It is suggested that PLSR may be a useful tool in QTL analysis.


Assuntos
Fungos/fisiologia , Hordeum/microbiologia , Hordeum/fisiologia , Imunidade Inata/fisiologia , Mapeamento Cromossômico , Interpretação Estatística de Dados , Análise dos Mínimos Quadrados , Locos de Características Quantitativas , Análise de Regressão , Software
12.
Neurology ; 61(6): 775-82, 2003 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-14504320

RESUMO

BACKGROUND: In the setting of severe immunosuppression, the polyomavirus JC (JCV) can cause a lytic infection of oligodendrocytes. This demyelinating disease of the CNS white matter (WM) is called progressive multifocal leukoencephalopathy (PML). JCV has a very narrow host-cell range and productive infection of neurons has never been demonstrated. Patient, methods, and results: An HIV-1-infected patient presented with signs of pyramidal tract and cerebellar dysfunction. Brain MRI revealed T2 hyperintensities in the WM of both frontal lobes and cerebellar atrophy. His disease progressed despite therapy and he died 6 months later. In addition to classic PML findings in the frontal lobe WM, autopsy revealed scattered foci of tissue destruction in the internal granule cell layer (IGCL) of the cerebellum. In these foci, enlarged granule cell neurons identified by the neuronal markers MAP-2 and NeuN reacted with antibodies specific for the polyomavirus VP1 capsid protein. Electron microscopy showed 40 nm viral particles, consistent with polyomaviruses, in these granule cell neurons. In addition, JCV DNA was detected by PCR after laser capture microdissection of cells from the areas of focal cell loss. Finally, in situ hybridization studies demonstrated that many granule cell neurons were infected with JCV but did not contain viral proteins. Sequence analysis of the JCV regulatory region from cerebellar virions showed a tandem repeat pattern also found in PML lesions of the frontal lobe WM. CONCLUSION: JCV can productively infect granule cell neurons of the IGCL of the cerebellum. This suggests a role for JCV infection of neurons in cerebellar atrophy occurring in HIV-infected individuals.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Cerebelo/virologia , Vírus JC/isolamento & purificação , Leucoencefalopatia Multifocal Progressiva/virologia , Neurônios/virologia , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Adulto , Fármacos Anti-HIV/uso terapêutico , Antivirais/uso terapêutico , Astrócitos/virologia , Capsídeo/ultraestrutura , DNA Viral/análise , Progressão da Doença , Evolução Fatal , HIV-1 , Humanos , Hibridização In Situ , Corpos de Inclusão Viral , Vírus JC/fisiologia , Leucoencefalopatia Multifocal Progressiva/complicações , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico , Masculino , Microscopia Eletrônica , Oligodendroglia/virologia , Especificidade de Órgãos , Ativação Viral , Replicação Viral
13.
Oncologist ; 6(6): 496-505, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11743212

RESUMO

Within the last 5 years there has been a large outgrowth of smoking cessation research, largely encouraged by the release of the 1996 Clinical Practice Guidelines for Treating Tobacco Use and Dependence. These federal guidelines published by the Agency for Healthcare Policy and Research offered comprehensive empirical evidence that tobacco cessation interventions are effective and encouraged routine implementation within medical settings. Since that time, numerous studies in tobacco cessation have augmented the state of knowledge regarding successful smoking intervention modalities. Unfortunately, approximately one-third of cancer-related deaths continue to be attributed to smoking behaviors. It is imperative that health care providers encourage and participate in the smoking cessation efforts of their patients and family members. This article provides a review of the current literature in smoking cessation and describes first-line therapies with proven effectiveness in tobacco cessation. Clinicians are encouraged to consistently screen for tobacco use and provide brief interventions utilizing behavioral counseling and pharmacotherapies to treat their patients' tobacco dependence.


Assuntos
Neoplasias Pulmonares/prevenção & controle , Oncologia , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar , Guias como Assunto/normas , Humanos , Oncologia/tendências
14.
Plant Mol Biol ; 47(3): 367-78, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11587508

RESUMO

A new member of the GT-2 family of transcription factors, GmGT-2, was isolated from soybean while screening a cDNA library with a protein binding site (D1) in the promoter of Aux28, a member of the Aux/IAA family of auxin-responsive genes. GmGT-2 possesses various primary amino acid sequence characteristics common to all GT-2 factors thus far isolated, including sequence identity in the twin trihelix DNA-binding domains. Recombinant GmGT-2 expressed in Escherichia coli binds oligotetramers of both D1 and various GT-boxes. However, unlike other known members of the GT-2 family, GmGT-2 message levels are down-regulated by light in a phytochrome-dependent manner. Evidence is presented that the expression levels of Aux28 mRNA are also down-regulated by phytochrome. These results and other referenced data implicate the possible convergence of phytochrome and auxin signaling pathways.


Assuntos
Glycine max/genética , Luz , Fitocromo/fisiologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , DNA Complementar/química , DNA Complementar/genética , DNA Complementar/isolamento & purificação , DNA de Plantas/química , DNA de Plantas/genética , DNA de Plantas/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Ácidos Indolacéticos/farmacologia , Dados de Sequência Molecular , Proteínas de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Glycine max/crescimento & desenvolvimento , Transcrição Gênica
15.
Otolaryngol Clin North Am ; 34(4): 739-51, vi, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11511473

RESUMO

Complications are part of every surgical procedure and their occurrences are inevitable if the surgeon performs enough operations during his/her lifetime. Learning how to prevent complications and how to manage them when they occur are as important as learning how to perform any given surgical procedure. This is especially true in facial reconstruction with local flaps, as complications threaten not only the functional restoration of the integrity, but also the cosmetic appearance of the patient. This article describes common complications and their underlying mechanisms seen in facial reconstruction with local flaps as well as their treatment or prevention, when possible.


Assuntos
Face/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Complicações Pós-Operatórias , Terapia de Salvação/métodos , Retalhos Cirúrgicos , Cicatriz/cirurgia , Face/irrigação sanguínea , Humanos , Isquemia , Necrose
16.
J Adolesc Health ; 28(3): 167-9, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11226838

RESUMO

The Second Chance Club, a high school-based intervention for pregnant and parenting adolescents, was evaluated to determine the repeat birth rate among participants. A retrospective case-controlled cohort study was conducted (participants, n = 50; control subjects, n = 255) over 3 years after enrollment in the intervention. Repeat births occurred in 3/50 (6%) of participants and 95/255 (37%) of controls (p <.05).


Assuntos
Serviços de Saúde do Adolescente , Gravidez na Adolescência/prevenção & controle , Serviços de Saúde Escolar , Adolescente , Adulto , Coeficiente de Natalidade , Feminino , Humanos , Gravidez , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Fatores de Risco , South Carolina/epidemiologia
17.
Otolaryngol Head Neck Surg ; 123(5): 543-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11077337

RESUMO

OBJECTIVE: Preservation of the supratrochlear vascular pedicle (SVP) during use of the paramedian forehead flap can be accomplished by the aid of Doppler imaging; however, a reliable surface landmark may be invaluable in cases where Doppler examination fails. Our observations showed that the most prominent glabellar frown lines (GFLs) are very close to the SVP; however, the actual relationship of these structures remains unclear. STUDY DESIGN: The relationship between GFLs and the SVP was investigated in 19 volunteers by the aid of Doppler imaging and in 8 cadaver heads by dissection. The distance between the GFLs and the SVP was measured. SETTING: The study took place at an academic tertiary-care facility. RESULTS: The SVP was located just at the GFLs in almost 50% of the cases and an average of 3.2 mm lateral to GFLs in the remaining cases. CONCLUSION: GFLs may serve as reliable surface landmarks in the use of the paramedian forehead flap where Doppler imaging was not helpful.


Assuntos
Testa/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias/anatomia & histologia , Humanos , Pessoa de Meia-Idade
18.
J Synchrotron Radiat ; 7(Pt 4): 236-44, 2000 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16609201

RESUMO

Wavelength normalization is an essential part of processing of Laue X-ray diffraction data and is critically important for deriving accurate structure-factor amplitudes. The results of wavelength normalization for Laue data obtained in nanosecond time-resolved experiments at the ID09 beamline at the European Synchrotron Radiation Facility, Grenoble, France, are presented. Several wiggler and undulator insertion devices with complex spectra were used. The results show that even in the most challenging cases, such as wiggler/undulator tandems or single-line undulators, accurate wavelength normalization does not require unusually redundant Laue data and can be accomplished using typical Laue data sets. Single-line undulator spectra derived from Laue data compare well with the measured incident X-ray spectra. Successful wavelength normalization of the undulator data was also confirmed by the observed signal in nanosecond time-resolved experiments. Single-line undulators, which are attractive for time-resolved experiments due to their high peak intensity and low polychromatic background, are compared with wigglers, based on data obtained on the same crystal.

20.
CLAO J ; 25(4): 218-21, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10555737

RESUMO

PURPOSE: We conducted a 15-month prospective clinical studyto evaluate the performance of the Acuvue Bifocal contact lens and to determine the objective and subjective factors that influence patient success rates in a general presbyopic population presenting to a contact lens specialist's office. METHODS: The first 100 patients who were initially fit and dispensed the Acuvue Bifocal contact lens are included in this study data. At each follow-up visit, visual acuity, slit lamp evaluation of lens/cornea relationship, and any change in ocular surface characteristics were noted. The study population was a general population with an interest in wearing disposable multifocal contact lenses. Success was defined as the patient actually purchasing the lens for continual wear. RESULTS: The overall success rate with the lens in this diverse study group was 53%. The majority of the successful patients achieved 20/25 or better distance and near acuity with the Acuvue Bifocal. None of the study participants had any adverse effect of lens wear or changes in keratometry or ocular surface characteristics. Of the successful patients, 57% wore the lens in a binocular fashion, while the remainder used some form of monovision. Virtually all patients rated lens comfort as excellent or very good, with the major factor in success or failure being visual performance. CONCLUSIONS: This prospective study in an average group of presbyopic contact lens or spectacle wearers yielded valuable insights into the performance of a disposable multifocal contact lens in a general contact lens practice. The Acuvue Bifocal should prove to be a valuable addition to the contact lens fitter's practice.


Assuntos
Lentes de Contato Hidrofílicas , Presbiopia/terapia , Adulto , Idoso , Estudos de Avaliação como Assunto , Feminino , Humanos , Hiperopia/complicações , Hiperopia/fisiopatologia , Hiperopia/terapia , Masculino , Pessoa de Meia-Idade , Miopia/complicações , Miopia/fisiopatologia , Miopia/terapia , Presbiopia/complicações , Presbiopia/fisiopatologia , Estudos Prospectivos , Resultado do Tratamento , Acuidade Visual
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