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1.
Sensors (Basel) ; 24(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38475120

RESUMO

Repetitive transcranial magnetic stimulation (rTMS) is a rapidly developing therapeutic modality for the safe and effective treatment of neuropsychiatric disorders. However, clinical rTMS driving systems and head coils are large, heavy, and expensive, so miniaturized, affordable rTMS devices may facilitate treatment access for patients at home, in underserved areas, in field and mobile hospitals, on ships and submarines, and in space. The central component of a portable rTMS system is a miniaturized, lightweight coil. Such a coil, when mated to lightweight driving circuits, must be able to induce B and E fields of sufficient intensity for medical use. This paper newly identifies and validates salient theoretical considerations specific to the dimensional scaling and miniaturization of coil geometries, particularly figure-8 coils, and delineates novel, key design criteria. In this context, the essential requirement of matching coil inductance with the characteristic resistance of the driver switches is highlighted. Computer simulations predicted E- and B-fields which were validated via benchtop experiments. Using a miniaturized coil with dimensions of 76 mm × 38 mm and weighing only 12.6 g, the peak E-field was 87 V/m at a distance of 1.5 cm. Practical considerations limited the maximum voltage and current to 350 V and 3.1 kA, respectively; nonetheless, this peak E-field value was well within the intensity range, 60-120 V/m, generally held to be therapeutically relevant. The presented parameters and results delineate coil and circuit guidelines for a future miniaturized, power-scalable rTMS system able to generate pulsed E-fields of sufficient amplitude for potential clinical use.


Assuntos
Projetos de Pesquisa , Estimulação Magnética Transcraniana , Humanos , Estimulação Magnética Transcraniana/métodos , Resultado do Tratamento , Simulação por Computador
2.
Can Assoc Radiol J ; 74(4): 629-634, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36718778

RESUMO

Purpose: Determine whether standardized template reporting for the preoperative assessment of potential living renal transplant donors improves the comprehensiveness of radiology reports to meet the needs of urologists performing renal transplants. Methods: Urologist and radiologist stakeholders from renal transplant centres in our province ratified a standardized reporting template for evaluation of potential renal donors. Three centres (A, B, and C) were designated "intervention" groups. Centre D was the control group, given employment of a site-specific standardized template prior to study commencement. Up to 100 consecutive CT scan reports per centre, pre- and post-implementation of standardized reporting, were evaluated for reporting specific outcome measures. Results: At baseline, all intervention groups demonstrated poor reporting of urologist-desired outcome measures. Centre A discussed 5/13 variables (38%), Centre B discussed 6/13 variables (46%), and Centre C only discussed 1/13 variables (8%) with ≥90% reliability. The control group exhibited consistent reporting, with 11/13 variables (85%) reported at ≥90% reliability. All institutions in the intervention group exhibited excellent compliance to structured reporting post-template implementation (Centres A = 95%, B = 100%, and C = 77%, respectively). Additionally, all intervention centres demonstrated a significant improvement in the comprehensiveness of reports post-template implementation, with statistically significant increases in the reporting of all variables under-reported at baseline (P > .01). Conclusion: Standardized templates across our province for CT scans of potential renal donors promote completeness of reports. Radiologists can reliably provide our surgical colleagues with needed preoperative anatomy and incidental findings, helping to determine suitable transplant donors and reduce potential complications associated with organ retrieval.


Assuntos
Transplante de Rim , Urologistas , Humanos , Imageamento por Ressonância Magnética , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
3.
Can Assoc Radiol J ; 73(3): 542-548, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34965171

RESUMO

PURPOSE: To determine if CT can improve the diagnostic confidence for the detection of sacroiliac joint (SIJ) erosions in patients with equivocal MRI findings. METHODS: A retrospective analysis of adult patients who had an SIJ MRI and a subsequent SIJ CT within 12 months was conducted. Using a 5-point Likert scale, two reviewers evaluated the de-identified MRI and CT images in randomized order and in separate sessions to answer the question: "Does the patient have SIJ erosions?". A Fisher's exact test was used to analyze the difference in diagnostic confidence, and intraclass correlation coefficient (ICC) was used to determine interrater reliability. RESULTS: 54 patients were included in the analysis (average age, 43.9 years). The average time interval between initial SIJ MRI and subsequent CT was 14.4 weeks (range, 5.6-50.3 weeks). CT resulted in significantly more cases with definitive diagnostic confidence than cases with probable or equivocal confidence compared to MRI (P < .001). Amongst cases with equivocal findings on MRI, 73.2% of cases had definitive diagnoses on CT. There was moderate interrater agreement for MRI, with an ICC of .490 [95% CI, .258-.669], and excellent agreement for CT, with an ICC of .832 [95% CI, .728-.899]. CONCLUSION: Overall, CT led to significantly increased diagnostic confidence and higher interrater reliability for the detection of SIJ erosions compared to MRI. Judicious use of CT may be useful in detecting SIJ erosions in patients with equivocal MRI findings.


Assuntos
Artropatias , Articulação Sacroilíaca , Tomografia Computadorizada por Raios X , Adulto , Humanos , Artropatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Reprodutibilidade dos Testes , Estudos Retrospectivos , Articulação Sacroilíaca/diagnóstico por imagem
4.
J Contemp Dent Pract ; 19(5): 599-604, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29807973

RESUMO

BACKGROUND: Amelogenesis imperfecta is a heterogeneous group of hereditary disorders that affect the enamel formation of the primary and permanent dentitions while the remaining tooth structure is normal. Appropriate patient care is necessary to prevent adverse effects on dental oral health, dental disfigurement, and psychological well-being. AIM: This clinical report presents a 27-year-old Chinese male with amelogenesis imperfecta (AI) and his restorative management. CASE REPORT: This clinical report presents a 27-year-old Chinese male with AI and his restorative management. Extraoral examination showed a skeletal class III profile and increased lower facial proportion. Intraorally, all the permanent dentition was hypoplastic with noticeable tooth surface loss and a yellow-brown appearance. This was complicated with a mild maloc-clusion and food packing on his posterior teeth. The patient wanted to improve his appearance and masticatory efficiency. Orthodontic treatment was performed to treat the mild malocclu-sion and create physiological interproximal spacing to minimize tooth preparation and facilitate oral hygiene. CONCLUSION: This report demonstrates how a multidisciplinary approach for the management of AI can achieve a predictable, functional, and esthetic outcome. Orthodontic treatment facilitated a conservative prosthodontic treatment outcome by selectively increasing interproximal space, minimizing tooth preparation, correcting posterior bilateral cross-bite, as well as an anterior reverse overjet and derotation of the canines. CLINICAL SIGNIFICANCE: This case report demonstrates the effective restoration of AI using a multidisciplinary approach to overcome crowding using a relatively conservative approach.


Assuntos
Amelogênese Imperfeita/reabilitação , Amelogênese Imperfeita/terapia , Ortodontia/métodos , Adulto , Amelogênese Imperfeita/diagnóstico por imagem , Cerâmica , Coroas , Materiais Dentários , Porcelana Dentária , Facetas Dentárias , Humanos , Comunicação Interdisciplinar , Masculino
5.
AJR Am J Roentgenol ; 209(2): 358-362, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28570128

RESUMO

OBJECTIVE: The purpose of this study was to investigate the effect of a biopsy center-a dedicated space with a dedicated ultrasound machine and technologist, staffed daily by a radiologist responsible for performing ultrasound-guided procedures only-on the rate of non-diagnostic or unsatisfactory thyroid fine-needle aspiration (FNA). MATERIALS AND METHODS: Three radiologists performed FNA on 1200 nodules in 998 patients between September 2010 and November 2015. We compared rates of nondiagnostic or unsatisfactory FNA before and after implementation of a biopsy center in September 2014 as part of a quality improvement initiative. Before the establishment of our biopsy center, ultrasound-guided procedures were scheduled between diagnostic studies in the main ultrasound department and were performed by a radiologist responsible for both. Multivariate logistic regression analysis was performed to assess the effect of the biopsy center on the odds of obtaining an adequate sample. RESULTS: Rates of nondiagnostic or unsatisfactory FNA decreased significantly from 15.1% to 8.5% (p < 0.001) after implementation of the biopsy center. The odds of obtaining an adequate sample were higher in the biopsy center (odds ratio, 2.07; 95% CI, 1.43-3.01), even after adjusting for patient age, nodule size, the radiologist performing the procedure, and time over the study period. CONCLUSION: The implementation of a biopsy center was associated with significantly lower rates of nondiagnostic or unsatisfactory thyroid FNA, suggesting target rates of 10% or lower are achievable with quality improvement measures.


Assuntos
Biópsia por Agulha Fina/métodos , Biópsia Guiada por Imagem/métodos , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Ultrassonografia de Intervenção , Adulto , Idoso , Idoso de 80 Anos ou mais , Competência Clínica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
6.
J Bacteriol ; 197(6): 1083-94, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25583974

RESUMO

The presence of multidrug-tolerant persister cells within microbial populations has been implicated in the resiliency of bacterial survival against antibiotic treatments and is a major contributing factor in chronic infections. The mechanisms by which these phenotypic variants are formed have been linked to stress response pathways in various bacterial species, but many of these mechanisms remain unclear. We have previously shown that in the cariogenic organism Streptococcus mutans, the quorum-sensing peptide CSP (competence-stimulating peptide) pheromone was a stress-inducible alarmone that triggered an increased formation of multidrug-tolerant persisters. In this study, we characterized SMU.2027, a CSP-inducible gene encoding a LexA ortholog. We showed that in addition to exogenous CSP exposure, stressors, including heat shock, oxidative stress, and ofloxacin antibiotic, were capable of triggering expression of lexA in an autoregulatory manner akin to that of LexA-like transcriptional regulators. We demonstrated the role of LexA and its importance in regulating tolerance toward DNA damage in a noncanonical SOS mechanism. We showed its involvement and regulatory role in the formation of persisters induced by the CSP-ComDE quorum-sensing regulatory system. We further identified key genes involved in sugar and amino acid metabolism, the clustered regularly interspaced short palindromic repeat (CRISPR) system, and autolysin from transcriptomic analyses that contribute to the formation of quorum-sensing-induced persister cells.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Percepção de Quorum/fisiologia , Serina Endopeptidases/metabolismo , Streptococcus mutans/efeitos dos fármacos , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Dados de Sequência Molecular , Serina Endopeptidases/genética , Streptococcus mutans/genética , Streptococcus mutans/metabolismo , Transcriptoma
8.
Radiol Med ; 120(1): 12-20, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25115294

RESUMO

Diaphragmatic injury is an uncommon traumatic condition. It can be easily missed due to a lack of awareness by both clinicians and radiologists. A high index of suspicion is required for the establishment of an early diagnosis and prevention of life-threatening complications. Multidetector computed tomography (MDCT) is the modality of choice for the detection of diaphragmatic injury. In this review article, we illustrate the MDCT appearance of blunt and penetrating diaphragmatic injuries and emphasize the role of the emergency radiologist in detecting these entities.


Assuntos
Diafragma/lesões , Tomografia Computadorizada Multidetectores/métodos , Traumatismos Torácicos/diagnóstico por imagem , Ferimentos não Penetrantes/diagnóstico por imagem , Meios de Contraste , Diagnóstico Diferencial , Diafragma/diagnóstico por imagem , Humanos , Interpretação de Imagem Radiográfica Assistida por Computador
9.
Can Assoc Radiol J ; 66(4): 310-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26100355

RESUMO

PURPOSE: Traumatic diaphragmatic rupture (TDR) is an uncommon injury that can be associated with significant morbidity if not detected and treated in a timely manner. The purpose of our study was to evaluate the diagnostic accuracy of 64-slice multidetector computed tomography (64-MDCT) for the detection of TDR in patients at our level 1 trauma centre. METHODS: We used our hospital's trauma registry to identify patients with a diagnosis of TDR from January 1, 2008, to December 31, 2012. Only patients with a 64-MDCT scan at presentation who subsequently underwent laparotomy/laparoscopy were included in the study cohort. Using surgical findings as the gold standard, the accuracy of the prospective radiology reports was analyzed. RESULTS: Of the 3225 trauma patients who presented to our institution, 38 (1.2%) had a TDR. Fourteen of the 38 were excluded as they did not have MDCT before surgery. The study cohort consisted of 20 males and 4 females with a median age of 34.5 years and a median Injury Severity Score (ISS90) of 26. Fifteen had blunt trauma while 9 had a penetrating injury. The overall sensitivity of the radiology reports was 66.7% (95% confidence interval [CI]: 46.7%-82.0%), specificity was 100% (95% CI: 94.1%-100%), positive predictive value was 100% (95% CI: 80.6%-100%), negative predictive value was 88.4% (95% CI: 78.8%-94.0%), and accuracy was 90.6% (95% CI: 82.5%-95.2%). However, only 3 of 9 patients with penetrating injury had a correct preoperative diagnosis. Two of the 6 missed penetrating trauma cases had only indirect signs of injury. CONCLUSIONS: The detection of TDR in trauma patients on 64-MDCT can be improved, especially in patients presenting with penetrating injury. A careful search for subtle diaphragmatic defects and indirect evidence of injury is important to avoid missing the diagnosis.


Assuntos
Hérnia Diafragmática Traumática/diagnóstico , Tomografia Computadorizada Multidetectores , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Hérnia Diafragmática Traumática/cirurgia , Humanos , Escala de Gravidade do Ferimento , Iohexol , Laparoscopia , Masculino , Pessoa de Meia-Idade , Ontário , Estudos Prospectivos , Sensibilidade e Especificidade , Centros de Traumatologia , Adulto Jovem
10.
Gastroenterology ; 145(1): 158-165.e2, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23583432

RESUMO

BACKGROUND & AIMS: Inflammatory bowel diseases (IBD) are becoming more common in Asia, but epidemiologic data are lacking. The Asia-Pacific Crohn's and Colitis Epidemiology Study aimed to determine the incidence and phenotype of IBD in 8 countries across Asia and in Australia. METHODS: We performed a prospective, population-based study of IBD incidence in predefined catchment areas, collecting data for 1 year, starting on April 1, 2011. New cases were ascertained from multiple overlapping sources and entered into a Web-based database. Cases were confirmed using standard criteria. Local endoscopy, pathology, and pharmacy records were searched to ensure completeness of case capture. RESULTS: We identified 419 new cases of IBD (232 of ulcerative colitis [UC], 166 of Crohn's disease [CD], and 21 IBD-undetermined). The crude annual overall incidence values per 100,000 individuals were 1.37 for IBD in Asia (95% confidence interval: 1.25-1.51; 0.76 for UC, 0.54 for CD, and 0.07 for IBD-undetermined) and 23.67 in Australia (95% confidence interval: 18.46-29.85; 7.33 for UC, 14.00 for CD, and 2.33 for IBD-undetermined). China had the highest incidence of IBD in Asia (3.44 per 100,000 individuals). The ratios of UC to CD were 2.0 in Asia and 0.5 in Australia. Median time from symptom onset to diagnosis was 5.5 months (interquartile range, 1.4-15 months). Complicated CD (stricturing, penetrating, or perianal disease) was more common in Asia than Australia (52% vs 24%; P = .001), and a family history of IBD was less common in Asia (3% vs 17%; P < .001). CONCLUSIONS: We performed a large-scale population-based study and found that although the incidence of IBD varies throughout Asia, it is still lower than in the West. IBD can be as severe or more severe in Asia than in the West. The emergence of IBD in Asia will result in the need for specific health care resources, and offers a unique opportunity to study etiologic factors in developing nations.


Assuntos
Doenças Inflamatórias Intestinais/epidemiologia , Adulto , Ásia/epidemiologia , Austrália/epidemiologia , Feminino , Humanos , Incidência , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Prospectivos
11.
Opt Lett ; 39(20): 5877-80, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25361108

RESUMO

A novel microfluidic flowmeter integrated with microfiber Bragg grating (µFBG) is presented. Two glass capillaries and a short length of high-light-absorption Co²âº-doped optical fiber were stacked inside a larger outer capillary tube. The stack was then drawn into a tapered device. Two microchannels with the diameter of ~50 µm were formed inside the capillaries for flowing of microfluidics. An FBG was inscribed in the tapered Co²âº-doped fiber with waist diameter of ~70 µm, and acts as a flow-rate sensor. A pump laser with wavelength of 1480 nm was utilized to locally heat the µFBG, rendering the µFBG as miniature "hot-wire" flowmeter. The flow rate of the liquid in the microchannels is determined by the induced wavelength shift of the µFBG. The experimental results achieve a minimum detectable change of ~16 nL/s in flow rate, which is very promising in the use as part of biochips.

13.
Analyst ; 139(21): 5422-9, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25142213

RESUMO

Photonic crystal fibres appear to be an ideal platform for the realisation of novel optofluidic devices and sensors due to their waveguide nature and microstructured architecture. In this paper, we present the fabrication and characterisation of an in-line photonic crystal fibre microfluidic refractometer enabled by a C-shaped fibre. The C-shaped fibre spliced in-between the photonic crystal fibre and the single-mode fibre allows simultaneous in-line optical signal delivery and analyte fluid feeding. Through an arc discharge pre-treatment technique, we successfully achieve selective exploitation of only the central two channels of the photonic crystal fibre for microfluidic sensing. After constructing a Sagnac interferometer, a highly sensitive refractometer with a sensitivity of 8699 nm per RIU was achieved experimentally; this agrees very well with the theoretical value of 8675 nm per RIU. As a demonstration for label-free optical sensing application, the refractometer was used to measure the concentration of NaCl solution with a sensitivity of 15.08 nm/(1 wt%) and a detection limit of 2.3 × 10(-3) wt% (23 ppm).


Assuntos
Microfluídica/métodos , Refratometria/instrumentação , Cristalização , Limite de Detecção , Microscopia Eletrônica de Varredura , Fótons
14.
Angew Chem Int Ed Engl ; 53(24): 6155-8, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24764260

RESUMO

A simple and inexpensive method is reported for the long-term stabilization of enzymes and other unstable reagents in premeasured quantities in water-soluble tablets (cast, not compressed) made with pullulan, a nonionic polysaccharide that forms an oxygen impermeable solid upon drying. The pullulan tablets dissolve in aqueous solutions in seconds, thereby facilitating the easy execution of bioassays at remote sites with no need for special reagent handling and liquid pipetting. This approach is modular in nature, thus allowing the creation of individual tablets for enzymes and their substrates. Proof-of-principle demonstrations include a Taq polymerase tablet for DNA amplification through PCR and a pesticide assay kit consisting of separate tablets for acetylcholinesterase and its chromogenic substrate, indoxyl acetate, both of which are highly unstable. The encapsulated reagents remain stable at room temperature for months, thus enabling the room-temperature shipping and storage of bioassay components.


Assuntos
Glucanos/química , Bioensaio , Carboidratos , Comprimidos
15.
Diagnostics (Basel) ; 14(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38472938

RESUMO

Multi-criteria optimization (MCO) function has been available on commercial radiotherapy (RT) treatment planning systems to improve plan quality; however, no study has compared Eclipse and RayStation MCO functions for prostate RT planning. The purpose of this study was to compare prostate RT MCO plan qualities in terms of discrepancies between Pareto optimal and final deliverable plans, and dosimetric impact of final deliverable plans. In total, 25 computed tomography datasets of prostate cancer patients were used for Eclipse (version 16.1) and RayStation (version 12A) MCO-based plannings with doses received by 98% of planning target volume having 76 Gy prescription (PTV76D98%) and 50% of rectum (rectum D50%) selected as trade-off criteria. Pareto optimal and final deliverable plan discrepancies were determined based on PTV76D98% and rectum D50% percentage differences. Their final deliverable plans were compared in terms of doses received by PTV76 and other structures including rectum, and PTV76 homogeneity index (HI) and conformity index (CI), using a t-test. Both systems showed discrepancies between Pareto optimal and final deliverable plans (Eclipse: -0.89% (PTV76D98%) and -2.49% (Rectum D50%); RayStation: 3.56% (PTV76D98%) and -1.96% (Rectum D50%)). Statistically significantly different average values of PTV76D98%,HI and CI, and mean dose received by rectum (Eclipse: 76.07 Gy, 0.06, 1.05 and 39.36 Gy; RayStation: 70.43 Gy, 0.11, 0.87 and 51.65 Gy) are noted, respectively (p < 0.001). Eclipse MCO-based prostate RT plan quality appears better than that of RayStation.

16.
Nat Electron ; 7(4): 313-324, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38737565

RESUMO

Networks of spatially distributed radiofrequency identification sensors could be used to collect data in wearable or implantable biomedical applications. However, the development of scalable networks remains challenging. Here we report a wireless radiofrequency network approach that can capture sparse event-driven data from large populations of spatially distributed autonomous microsensors. We use a spectrally efficient, low-error-rate asynchronous networking concept based on a code-division multiple-access method. We experimentally demonstrate the network performance of several dozen submillimetre-sized silicon microchips and complement this with large-scale in silico simulations. To test the notion that spike-based wireless communication can be matched with downstream sensor population analysis by neuromorphic computing techniques, we use a spiking neural network machine learning model to decode prerecorded open source data from eight thousand spiking neurons in the primate cortex for accurate prediction of hand movement in a cursor control task.

17.
Chem Asian J ; 19(4): e202300981, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38116878

RESUMO

We have developed a catalytic protocol for Diels-Alder reaction using trialkylphosphonium oxoborates as oxyanion hole catalysts. The reaction can be operated under ambient conditions. Dienes could easily polymerize under acidic condition. Nonetheless, these acid-sensitive substrates are compatible with the catalytic protocol and the reaction scope covers a wide range of substrates.

18.
Artigo em Inglês | MEDLINE | ID: mdl-38831996

RESUMO

Technological advances in radiation therapy impact on the role and scope of practice of the radiation therapist. The European Society of Radiotherapy and Oncology (ESTRO) recently held two workshops on this topic and this position paper reflects the outcome of this workshop, which included radiation therapists from all global regions. Workflows, quality assurance, research, IGRT and ART as well as clinical decision making are the areas of radiation therapist practice that will be highly influenced by advancing technology in the near future. This position paper captures the opportunities that this will bring to the radiation therapist profession, to the practice of radiation therapy and ultimately to patient care.

19.
Hum Mutat ; 34(9): 1289-97, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23757194

RESUMO

A CA-repeat microsatellite in insulin-like growth factor 1 (IGF1) promoter was associated with interindividual variation of circulating IGF1 level. Previously, we reported that such association was due to variation of haplotype unit in a linkage disequilibrium block composed of microsatellite and single-nucleotide polymorphisms (SNPs), suggesting the presence of an interaction between them. In this study, reporter assays were performed to investigate the regulatory effect and interaction of genetic variants on gene expression. We used an in vitro system to compare the transcriptional activities of haplotypes (rs35767:T>C, the CA-repeat microsatellite, rs5742612:T>C, and rs2288377:T>A) in evolutionarily conserved region of IGF1 promoter. In haplotype C-T-T, a longer microsatellite had a lower transcriptional activity (17.6 ± 2.4-fold for 17 repeats and 8.3 ± 1.1-fold for 21 repeats), whereas in haplotype T-C-A, such trend could not be observed, as the microsatellite with 21 repeats had the highest transcriptional activity (17.5 ± 2.3-fold). Because the microsatellite and SNPs affected the transcriptional activity of each other, there may be an interaction between them in the regulation of IGF1 expression. For the first time, we demonstrated that a noncoding microsatellite polymorphism could act as a functional unit and interact with SNPs in the regulation of transcription in human genome.


Assuntos
Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , Sequência de Bases , Regulação da Expressão Gênica , Variação Genética , Genoma Humano , Haplótipos , Humanos , Desequilíbrio de Ligação , Dados de Sequência Molecular , Regiões Promotoras Genéticas
20.
Opt Lett ; 38(9): 1385-7, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23632492

RESUMO

In this Letter, we reported on an ultrahigh birefringence photonic crystal fiber (PCF) with a germanium-doped elliptical core, which is fabricated in our lab using the stack-and-draw method. An ultrahigh birefringence of 1.1×10(-2) is obtained experimentally, which is close to the theoretical value of 1.4×10(-2) at the wavelength of 1550 nm. To our knowledge, this is the highest birefringence reported to date for fabricated index-guiding PCF. Fiber Bragg gratings (FBG) were written in the fiber to confirm its ultrahigh birefringence, and we demonstrated the capability to simultaneously measure the FBG's pressure and temperature experimentally. Because of the large separation of the two FBG peaks (>12 nm), such fiber is a promising candidate for a single polarization device.

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