26
|
Skoch J, Tahir R, Abruzzo T, Taylor JM, Zuccarello M, Vadivelu S. Predicting symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage with an artificial neural network in a pediatric population. Childs Nerv Syst 2017; 33:2153-2157. [PMID: 28852853 DOI: 10.1007/s00381-017-3573-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 08/09/2017] [Indexed: 01/23/2023]
Abstract
PURPOSE Artificial neural networks (ANN) are increasingly applied to complex medical problem solving algorithms because their outcome prediction performance is superior to existing multiple regression models. ANN can successfully identify symptomatic cerebral vasospasm (SCV) in adults presenting after aneurysmal subarachnoid hemorrhage (aSAH). Although SCV is unusual in children with aSAH, the clinical consequences are severe. Consequently, reliable tools to predict patients at greatest risk for SCV may have significant value. We applied ANN modeling to a consecutive cohort of pediatric aSAH cases to assess its ability to predict SCV. METHODS A retrospective chart review was conducted to identify patients < 21 years of age who presented with spontaneously ruptured, non-traumatic, non-mycotic, non-flow-related intracranial arterial aneurysms to our institution between January 2002 and January 2015. Demographics, clinical, radiographic, and outcome data were analyzed using an adapted ANN model using learned value nodes from the adult aneurysmal SAH dataset previously reported. The strength of the ANN prediction was measured between - 1 and 1 with - 1 representing no likelihood of SCV and 1 representing high likelihood of SCV. RESULTS Sixteen patients met study inclusion criteria. The median age for aSAH patients was 15 years. Ten underwent surgical clipping and 6 underwent endovascular coiling for definitive treatment. One patient experienced SCV and 15 did not. The ANN applied here was able to accurately predict all 16 outcomes. The mean strength of prediction for those who did not exhibit SCV was - 0.86. The strength for the one patient who did exhibit SCV was 0.93. CONCLUSIONS Adult-derived aneurysmal SAH value nodes can be applied to a simple AAN model to accurately predict SCV in children presenting with aSAH. Further work is needed to determine if ANN models can prospectively predict SCV in the pediatric aSAH population in toto; adapted to include mycotic, traumatic, and flow-related origins as well.
Collapse
|
27
|
Liu YY, Stehlik J, Eichler C, Mi X, Hartke TR, Gullans MJ, Taylor JM, Petta JR. Threshold Dynamics of a Semiconductor Single Atom Maser. PHYSICAL REVIEW LETTERS 2017; 119:097702. [PMID: 28949587 DOI: 10.1103/physrevlett.119.097702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate a single atom maser consisting of a semiconductor double quantum dot (DQD) that is embedded in a high-quality-factor microwave cavity. A finite bias drives the DQD out of equilibrium, resulting in sequential single electron tunneling and masing. We develop a dynamic tuning protocol that allows us to controllably increase the time-averaged repumping rate of the DQD at a fixed level detuning, and quantitatively study the transition through the masing threshold. We further examine the crossover from incoherent to coherent emission by measuring the photon statistics across the masing transition. The observed threshold behavior is in agreement with an existing single atom maser theory when small corrections from lead emission are taken into account.
Collapse
|
28
|
Buckley C, Carvalho MT, Young LK, Rider SA, McFadden C, Berlage C, Verdon RF, Taylor JM, Girkin JM, Mullins JJ. Precise spatio-temporal control of rapid optogenetic cell ablation with mem-KillerRed in Zebrafish. Sci Rep 2017; 7:5096. [PMID: 28698677 PMCID: PMC5506062 DOI: 10.1038/s41598-017-05028-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/23/2017] [Indexed: 11/09/2022] Open
Abstract
The ability to kill individual or groups of cells in vivo is important for studying cellular processes and their physiological function. Cell-specific genetically encoded photosensitizing proteins, such as KillerRed, permit spatiotemporal optogenetic ablation with low-power laser light. We report dramatically improved resolution and speed of cell targeting in the zebrafish kidney through the use of a selective plane illumination microscope (SPIM). Furthermore, through the novel incorporation of a Bessel beam into the SPIM imaging arm, we were able to improve on targeting speed and precision. The low diffraction of the Bessel beam coupled with the ability to tightly focus it through a high NA lens allowed precise, rapid targeting of subsets of cells at anatomical depth in live, developing zebrafish kidneys. We demonstrate that these specific targeting strategies significantly increase the speed of optoablation as well as fish survival.
Collapse
|
29
|
Xu H, Kemiktarak U, Fan J, Ragole S, Lawall J, Taylor JM. Observation of optomechanical buckling transitions. Nat Commun 2017; 8:14481. [PMID: 28248293 PMCID: PMC5337942 DOI: 10.1038/ncomms14481] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/04/2017] [Indexed: 11/10/2022] Open
Abstract
Correlated phases of matter provide long-term stability for systems as diverse as solids, magnets and potential exotic quantum materials. Mechanical systems, such as buckling transition spring switches, can have engineered, stable configurations whose dependence on a control variable is reminiscent of non-equilibrium phase transitions. In hybrid optomechanical systems, light and matter are strongly coupled, allowing engineering of rapid changes in the force landscape, storing and processing information, and ultimately probing and controlling behaviour at the quantum level. Here we report the observation of first- and second-order buckling transitions between stable mechanical states in an optomechanical system, in which full control of the nature of the transition is obtained by means of the laser power and detuning. The underlying multiwell confining potential we create is highly tunable, with a sub-nanometre distance between potential wells. Our results enable new applications in photonics and information technology, and may enable explorations of quantum phase transitions and macroscopic quantum tunnelling in mechanical systems. Optomechanical systems could form logic gates, but key requirements are two stable static states and the ability to switch between them. Here, the authors observe radiation-pressure induced buckling transitions in an optomechanical system, and control this transition by varying laser power and detuning.
Collapse
|
30
|
Gillespie JL, Anyah A, Taylor JM, Marlin JW, Taylor TA. A Versatile Method for Immunofluorescent Staining of Cells Cultured on Permeable Membrane Inserts. Med Sci Monit Basic Res 2016; 22:91-4. [PMID: 27616137 PMCID: PMC5029199 DOI: 10.12659/msmbr.900656] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 08/16/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Obtaining high-quality images of cellular structures via immunofluorescence staining is critical for cellular localization studies. Often, these studies cannot be performed in parallel with certain oncology, virology, pharmacokinetic, and drug absorption studies due to model system technicalities requiring the cells to be cultured on porous membranes rather than glass or plastic. MATERIAL AND METHODS Here, we report a method of immunofluorescent staining of cells cultured on permeable membranes. RESULTS As proof of principle, HeLa cells grown on Transwell® membrane supports were stained with fluorescently labeled antibodies using this modified immunofluorescence staining method and visualized by fluorescent microscopy. CONCLUSIONS This protocol is a convenient alternative to staining cells on glass coverslips, thereby expanding the scope and applications of this important research tool.
Collapse
|
31
|
Gullans MJ, Stehlik J, Liu YY, Eichler C, Petta JR, Taylor JM. Sisyphus Thermalization of Photons in a Cavity-Coupled Double Quantum Dot. PHYSICAL REVIEW LETTERS 2016; 117:056801. [PMID: 27517784 PMCID: PMC5245799 DOI: 10.1103/physrevlett.117.056801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Indexed: 06/06/2023]
Abstract
We investigate the nonclassical states of light that emerge in a microwave resonator coupled to a periodically driven electron in a nanowire double quantum dot (DQD). Under certain drive configurations, we find that the resonator approaches a thermal state at the temperature of the surrounding substrate with a chemical potential given by a harmonic of the drive frequency. Away from these thermal regions we find regions of gain and loss, where the system can lase, or regions where the DQD acts as a single-photon source. These effects are observable in current devices and have broad utility for quantum optics with microwave photons.
Collapse
|
32
|
Trück J, Kelly DF, Taylor JM, Kienzler AK, Lester T, Seller A, Pollard AJ, Patel SY. Variable phenotype and discrete alterations of immune phenotypes in CTP synthase 1 deficiency: Report of 2 siblings. J Allergy Clin Immunol 2016; 138:1722-1725.e6. [PMID: 27543071 DOI: 10.1016/j.jaci.2016.04.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/31/2016] [Accepted: 04/13/2016] [Indexed: 12/24/2022]
|
33
|
Taylor JM, Horn P, Yeramaneni S, Sucharew H, Khoury J. Abstract WP408: Temporal Trends in Pediatric Stroke Hospitalization From 2000 - 2009: Analysis of the KID Inpatient Database. Stroke 2016. [DOI: 10.1161/str.47.suppl_1.wp408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background/Hypothesis:
Stroke in children ≤18 years is an important public health problem. The incidence of stroke in adults has been falling over several decades, likely attributable to better management of vascular risk factors. Children have different risk factors for cerebrovascular disease, however we wanted to see if similar trends were observed in pediatric stroke. We examined pediatric hospital discharges for stroke over the last decade.
Methods:
We used the Kids’ Inpatient Database (KID) for 2000, 2003, 2006, and 2009 using the published weighting guidelines to estimate the number of overall discharges and number of discharges due to stroke. To identify stroke we queried primary position discharge ICD-9 stroke codes 430, 431, 432.9, 434.X1, 434.9, and 435.9; previously identified to have high PPV for detection of stroke in children in a physician-verified epidemiology stroke study. We calculated incidence for stroke among hospitalized children as number of stroke discharges / total number of discharges, and expressed the ratio per 100,000 discharges. We compared trends in stroke type, age, race and sex over the decade.
Results:
Stroke incidence in 2000 was 26.4 (95% CI 23.2-29.6). In the 2009 sample, incidence was 30.9 (27.7-34.1) showing a non-significant increasing trend over time. Ischemic stroke was increasingly diagnosed over the same interval with a statistically significantly higher incidence in 2006 and 2009 compared to 2000 (Figure 1). Groups with highest stroke incidence in hospitalized children were 10-14 year olds, males, and children identifying with the racial group “black.”
Conclusion:
In the KID database, we identified a rising incidence of ischemic stroke diagnosis over the past decade, however the overall rate of pediatric stroke has not increased significantly. The increasing rate of an ischemic stroke discharge diagnosis may be the result of increased awareness of childhood stroke.
Collapse
|
34
|
Gullans MJ, Taylor JM. Optical Control of Donor Spin Qubits in Silicon. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS 2015; 92:195411. [PMID: 28127227 PMCID: PMC5259753 DOI: 10.1103/physrevb.92.195411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We show how to achieve optical, spin-selective transitions from the ground state to excited orbital states of group-V donors (P, As, Sb, Bi) in silicon. We consider two approaches based on either resonant, far-infrared (IR) transitions of the neutral donor or resonant, near-IR excitonic transitions. For far-IR light, we calculate the dipole matrix elements between the valley-orbit and spin-orbit split states for all the goup-V donors using effective mass theory. We then calculate the maximum rate and amount of electron-nuclear spin-polarization achievable through optical pumping with circularly polarized light. We find this approach is most promising for Bi donors due to their large spin-orbit and valley-orbit interactions. Using near-IR light, spin-selective excitation is possible for all the donors by driving a two-photon Λ-transition from the ground state to higher orbitals with even parity. We show that externally applied electric fields or strain allow similar, spin-selective Λ-transition to odd-parity excited states. We anticipate these results will be useful for future spectroscopic investigations of donors, quantum control and state preparation of donor spin qubits, and for developing a coherent interface between donor spin qubits and single photons.
Collapse
|
35
|
Abstract
This work reviews specific related aspects of hepatitis delta virus (HDV) reproduction, including virion structure, the RNA genome, the mode of genome replication, the delta antigens, and the assembly of HDV using the envelope proteins of its helper virus, hepatitis B virus (HBV). These topics are considered with perspectives ranging from a history of discovery through to still-unsolved problems. HDV evolution, virus entry, and associated pathogenic potential and treatment of infections are considered in other articles in this collection.
Collapse
|
36
|
Liu YY, Stehlik J, Gullans MJ, Taylor JM, Petta JR. Injection Locking of a Semiconductor Double Quantum Dot Micromaser. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2015; 92:053802. [PMID: 28127226 PMCID: PMC5259738 DOI: 10.1103/physreva.92.053802] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Emission linewidth is an important figure of merit for masers and lasers. We recently demonstrated a semiconductor double quantum dot (DQD) micromaser where photons are generated through single electron tunneling events. Charge noise directly couples to the DQD energy levels, resulting in a maser linewidth that is more than 100 times larger than the Schawlow-Townes prediction. Here we demonstrate a linewidth narrowing of more than a factor 10 by locking the DQD emission to a coherent tone that is injected to the input port of the cavity. We measure the injection locking range as a function of cavity input power and show that it is in agreement with the Adler equation. The position and amplitude of distortion sidebands that appear outside of the injection locking range are quantitatively examined. Our results show that this unconventional maser, which is impacted by strong charge noise and electron-phonon coupling, is well described by standard laser models.
Collapse
|
37
|
Thomas AE, Guyver PM, Taylor JM, Czipri M, Talbot NJ, Sharpe IT. Tibiotalocalcaneal arthrodesis with a compressive retrograde nail: A retrospective study of 59 nails. Foot Ankle Surg 2015; 21:202-5. [PMID: 26235861 DOI: 10.1016/j.fas.2015.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 01/01/2015] [Accepted: 01/02/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND Tibiotalocalcaneal arthrodesis is an important salvage method for patients with complex hindfoot problems. This study reports the elective results of combined subtalar and ankle arthrodesis using one design of retrograde intramedullary compression nail. METHODS Retrospective review identified 58 patients undergoing 59 tibiotalocalcaneal arthrodesis procedures. Mean follow up was 9.15 (3-36) months with average age 60.7 (22-89) years. A function and subjective patient satisfaction questionnaire was achieved in 89%. RESULTS 53 patients (93%) achieved union at a mean time of 4.17 months. Four patients (8%) subjectively thought the procedure was of no benefit while 42 (84%) had an excellent or good result. The mean visual analogue scale (VAS) score for preoperative functional pain was 7.46 compared to 1.98 post-operatively (p<0.001). CONCLUSIONS This device and technique offers an effective treatment of hindfoot pathology giving reliable compression and subsequent fusion with excellent patient satisfaction and pain relief. LEVEL OF EVIDENCE IV case series.
Collapse
|
38
|
Gullans MJ, Liu YY, Stehlik J, Petta JR, Taylor JM. Phonon-assisted gain in a semiconductor double quantum dot maser. PHYSICAL REVIEW LETTERS 2015; 114:196802. [PMID: 26024190 DOI: 10.1103/physrevlett.114.196802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Indexed: 06/04/2023]
Abstract
We develop a microscopic model for the recently demonstrated double-quantum-dot maser. In characterizing the gain of this device we find that, in addition to the direct stimulated emission of photons, there is a large contribution from the simultaneous emission of a photon and a phonon, i.e., the phonon sideband. We show that this phonon-assisted gain typically dominates the overall gain, which leads to masing. Recent experimental data are well fit with our model.
Collapse
|
39
|
Withers HR, Maciejewski B, Taylor JM, Hliniak A. Accelerated repopulation in head and neck cancer. FRONTIERS OF RADIATION THERAPY AND ONCOLOGY 2015; 22:105-10. [PMID: 3350350 DOI: 10.1159/000415101] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
40
|
Bishop JM, Deng CT, Faras AJ, Goodman HM, Guntaka RR, Levinson WE, Cordell-Stewart B, Taylor JM, Varmus HE. Transcription of the Rous sarcoma virus genome in vitro and in vivo. BIBLIOTHECA HAEMATOLOGICA 2015:517-23. [PMID: 51635 DOI: 10.1159/000397569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
RNA-directed DNA synthesis by detergent-disrupted virions of Rous sarcoma virus (RSV) initiates by the covalent attachment of pdA to the 3'-terminal rA of a 4S RNA hydrogen-bonded to the 70S RNA template. This 4S "primer" has structural features of tRNA and can be aminoacylated with methionine. Synthesis and integration of provirus DNA can be monitored in both permissive (duck) and nonpermissive (mouse) cells acutely infected with RSV. The results of these studies, as well as data obtained with RSV-infected mammalian cells which have reverted from a transformed to a pheno-typically normal state, indicate that integration of viral genes into the host chromosome is not sufficient cause for transformation. Pertinent features of virus-specific RNA-directed DNA synthesis in vitro and in vivo are reviewed and compared.
Collapse
|
41
|
Gamarel KE, Neilands TB, Dilworth SE, Taylor JM, Johnson MO. Smoking, internalized heterosexism, and HIV disease management among male couples. AIDS Care 2014; 27:649-54. [PMID: 25506724 DOI: 10.1080/09540121.2014.991269] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
High rates of cigarette smoking have been observed among HIV-positive individuals. Smoking has been linked to HIV-related medical complications and non-AIDS defining cancers and negatively impacts on immune function and virologic control. Although internalized heterosexism has been related to smoking behaviors, little is known about associations between partners' reports of smoking, internalized heterosexism, and HIV medication management in male couples with HIV. A sample of 266 male couples completed baseline assessments for a cohort study examining relationship factors and HIV treatment. A computer-based survey assessed self-reported smoking behaviors, alcohol use, internalized heterosexism, and antiretroviral therapy (ART) adherence. HIV-positive men also provided blood samples to assess viral load. Approximately 30% of the sample reported that they are currently smoking cigarettes. After adjusting for demographic characteristics, men in a primary relationship with a partner who reported currently smoking had more than five-fold greater odds of reporting smoking. Higher levels of internalized heterosexism and financial hardship were each independently associated with greater odds of reporting smoking. Among HIV-positive men on ART (n = 371), having a partner who reported smoking was associated with almost three-fold greater odds of having a detectable viral load. Our findings add new support to the evidence of romantic partners influencing each other's health behaviors, and demonstrate an association between smoking and disease management within male couples. Future research should explore the interpersonal and social contexts of smoking in order to develop interventions that meet the unique needs of male couples.
Collapse
|
42
|
Abstract
Although the 10-item Perceived Stress Scale (PSS-10) is a popular measure, a review of the literature reveals 3 significant gaps: (a) There is some debate as to whether a 1- or a 2-factor model best describes the relationships among the PSS-10 items, (b) little information is available on the performance of the items on the scale, and (c) it is unclear whether PSS-10 scores are subject to gender bias. These gaps were addressed in this study using a sample of 1,236 adults from the National Survey of Midlife Development in the United States II. Based on self-identification, participants were 56.31% female, 77% White, 17.31% Black and/or African American, and the average age was 54.48 years (SD = 11.69). Findings from an ordinal confirmatory factor analysis suggested the relationships among the items are best described by an oblique 2-factor model. Item analysis using the graded response model provided no evidence of item misfit and indicated both subscales have a wide estimation range. Although t tests revealed a significant difference between the means of males and females on the Perceived Helplessness Subscale (t = 4.001, df = 1234, p < .001), measurement invariance tests suggest that PSS-10 scores may not be substantially affected by gender bias. Overall, the findings suggest that inferences made using PSS-10 scores are valid. However, this study calls into question inferences where the multidimensionality of the PSS-10 is ignored.
Collapse
|
43
|
Mittal S, Fan J, Faez S, Migdall A, Taylor JM, Hafezi M. Topologically robust transport of photons in a synthetic gauge field. PHYSICAL REVIEW LETTERS 2014; 113:087403. [PMID: 25192126 DOI: 10.1103/physrevlett.113.087403] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Indexed: 06/03/2023]
Abstract
Electronic transport is localized in low-dimensional disordered media. The addition of gauge fields to disordered media leads to fundamental changes in the transport properties. We implement a synthetic gauge field for photons using silicon-on-insulator technology. By determining the distribution of transport properties, we confirm that waves are localized in the bulk and localization is suppressed in edge states. Our system provides a new platform for investigating the transport properties of photons in the presence of synthetic gauge fields.
Collapse
|
44
|
Liu YY, Petersson KD, Stehlik J, Taylor JM, Petta JR. Photon emission from a cavity-coupled double quantum dot. PHYSICAL REVIEW LETTERS 2014; 113:036801. [PMID: 25083659 DOI: 10.1103/physrevlett.113.036801] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Indexed: 06/03/2023]
Abstract
We study a voltage biased InAs double quantum dot (DQD) that is coupled to a superconducting transmission line resonator. Inelastic tunneling in the DQD is mediated by electron phonon coupling and coupling to the cavity mode. We show that electronic transport through the DQD leads to photon emission from the cavity at a rate of 10 MHz. With a small cavity drive field, we observe a gain of up to 15 in the cavity transmission. Our results are analyzed in the context of existing theoretical models and suggest that it may be necessary to account for inelastic tunneling processes that proceed via simultaneous emission of a phonon and a photon.
Collapse
|
45
|
Taylor JM. Host RNA circles and the origin of hepatitis delta virus. World J Gastroenterol 2014; 20:2971-2978. [PMID: 24659888 PMCID: PMC3961984 DOI: 10.3748/wjg.v20.i11.2971] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 12/20/2013] [Accepted: 02/20/2014] [Indexed: 02/06/2023] Open
Abstract
Recent reports show that many cellular RNAs are processed to form circular species that are relatively abundant and resistant to host nucleases. In some cases, such circles actually bind host microRNAs. Such depletion of available microRNAs appears to have biological roles; for instance, in homeostasis and disease. These findings regarding host RNA circles support a speculative reappraisal of the origin and mode of replication of hepatitis delta virus, hepatitis delta virus (HDV), an agent with a small circular RNA genome; specifically, it is proposed that in hepatocytes infected with hepatitis B virus (HBV), some viral RNA species are processed to circular forms, which by a series of chance events lead to an RNA that can be both replicated by host enzymes and assembled, using HBV envelope proteins, to form particles some of which are infectious. Such a model also may provide some new insights into the potential pathogenic potential of HDV infections. In return, new insights into HDV might provide information leading to a better understanding of the roles of the host RNA circles.
Collapse
|
46
|
Xu H, Hafezi M, Fan J, Taylor JM, Strouse GF, Ahmed Z. Ultra-sensitive chip-based photonic temperature sensor using ring resonator structures. OPTICS EXPRESS 2014; 22:3098-3104. [PMID: 24663600 DOI: 10.1364/oe.22.003098] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Resistance thermometry provides a time-tested method for taking temperature measurements. However, fundamental limits to resistance-based approaches has produced considerable interest in developing photonic temperature sensors to leverage advances in frequency metrology and to achieve greater mechanical and environmental stability. Here we show that silicon-based optical ring resonator devices can resolve temperature differences of 1 mK using the traditional wavelength scanning methodology. An even lower noise floor of 80 μK for measuring temperature difference is achieved in the side-of-fringe, constant power mode measurement.
Collapse
|
47
|
Gamarel KE, Starks TJ, Dilworth SE, Neilands TB, Taylor JM, Johnson MO. Personal or relational? Examining sexual health in the context of HIV serodiscordant same-sex male couples. AIDS Behav 2014. [PMID: 23636681 DOI: 10.1007/s10461-013-0490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Couples' ability to adopt a "we" orientation has been associated with optimal health outcomes. This study examined how personal and relational motivations are uniquely associated with unprotected anal intercourse (UAI), protected anal intercourse (PAI), and the absence of sexual activity within HIV-serodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (N = 116 couples, 232 men) completed questionnaires and HIV-positive men had blood drawn for viral load. Results of a multinomial logistic regression illustrated that sexual satisfaction was positively associated with PAI among HIV-negative partners and negatively associated with PAI among HIV-positive partners. Endorsing a "we" orientation was positively associated with PAI among HIV-positive partners. Findings suggest that HIV-positive partners who espouse a "we" orientation may be willing to forgo their personal interests to protect their HIV-negative partners from HIV transmission. Couples-based interventions are warranted to help strengthen relationship dynamics to enhance the sexual health of serodiscordant couples.
Collapse
|
48
|
Gamarel KE, Starks TJ, Dilworth SE, Neilands TB, Taylor JM, Johnson MO. Personal or relational? Examining sexual health in the context of HIV serodiscordant same-sex male couples. AIDS Behav 2014; 18:171-9. [PMID: 23636681 PMCID: PMC3982720 DOI: 10.1007/s10461-013-0490-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Couples' ability to adopt a "we" orientation has been associated with optimal health outcomes. This study examined how personal and relational motivations are uniquely associated with unprotected anal intercourse (UAI), protected anal intercourse (PAI), and the absence of sexual activity within HIV-serodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (N = 116 couples, 232 men) completed questionnaires and HIV-positive men had blood drawn for viral load. Results of a multinomial logistic regression illustrated that sexual satisfaction was positively associated with PAI among HIV-negative partners and negatively associated with PAI among HIV-positive partners. Endorsing a "we" orientation was positively associated with PAI among HIV-positive partners. Findings suggest that HIV-positive partners who espouse a "we" orientation may be willing to forgo their personal interests to protect their HIV-negative partners from HIV transmission. Couples-based interventions are warranted to help strengthen relationship dynamics to enhance the sexual health of serodiscordant couples.
Collapse
|
49
|
Taylor JM. Virus entry mediated by hepatitis B virus envelope proteins. World J Gastroenterol 2013; 19:6730-6734. [PMID: 24187448 PMCID: PMC3812472 DOI: 10.3748/wjg.v19.i40.6730] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 09/17/2013] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV), a major cause of human liver disease worldwide, encodes three envelope proteins needed for the attachment and entry of the virus into susceptible host cells. A second virus, hepatitis delta virus, which is known to enhance liver disease in HBV infected patients, diverts the same HBV envelope proteins to achieve its own assembly and infection. In the lab, lentiviral vectors based on human immunodeficiency virus type 1 can be assembled using the HBV envelope proteins, and will similarly infect susceptible cells. This article provides a partial review and some personal reflections of how these three viruses infect and of how recipient cells become susceptible, along with some consideration of questions that remain to be answered.
Collapse
|
50
|
Taylor JM, Telford RJ, Kinsella DC, Watkinson AF, Thompson JF. Long-term clinical and functional outcome following treatment for Paget–Schroetter syndrome. Br J Surg 2013; 100:1459-64. [DOI: 10.1002/bjs.9279] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2013] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Effort-related thrombosis of the axillosubclavian vein (Paget–Schroetter syndrome, PSS) is uncommon. It tends to affect young, active individuals and yet consensus on management is lacking. The aim here was to analyse late outcomes in a series of patients treated for PSS using a standard protocol.
Methods
The medical records of patients treated for PSS over 16 years were analysed. Patients were divided into four groups according to their management. Clinical and functional outcomes were analysed regarding residual venous defects after treatment, and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire scores, respectively.
Results
Some 117 patients (52 men and 65 women, mean age 32 years) were included. Catheter-directed thrombolysis was successful in 42 of 56 treated patients. Thoracic outlet decompression surgery was performed in 95 patients. DASH scores improved significantly in patients treated surgically (P < 0.001 to P = 0·009); early surgery had a better outcome than delayed surgery (P = 0·040). Patients who were managed conservatively showed no improvement (P = 0·116). Where venoplasty was necessary, it was successful in 18 of 25 patients. A short duration of lysis (less than 24 h) increased the risk of rethrombosis (P = 0·020). The method of postoperative anticoagulation had no influence on the rate of rethrombosis.
Conclusion
Patients treated surgically for PSS had better functional outcomes than those managed conservatively. Prompt thrombolysis and surgery was superior to delayed management with respect to rethrombosis and functional outcome.
Collapse
|