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1.
Nature ; 557(7703): 71-75, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29618820

RESUMEN

In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3-7, including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 1015 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10-12-two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10-20 GeV.

2.
Nature ; 561(7722): 211-215, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30135588

RESUMEN

In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum1,2. The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-α line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-α forest'3 of absorption lines at different redshifts. Here we report the observation of the Lyman-α transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 ± 0.12 gigahertz (1σ uncertainty) and agrees with the prediction for hydrogen to a precision of 5 × 10-8. Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter and antimatter. Alongside the ground-state hyperfine4,5 and 1S-2S transitions6,7 recently observed in antihydrogen, the Lyman-α transition will permit laser cooling of antihydrogen8,9, thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements10. In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.

4.
Int J Behav Nutr Phys Act ; 20(1): 78, 2023 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-37403160

RESUMEN

BACKGROUND: Vigorous Intermittent Lifestyle Physical Activity (VILPA) refers to brief bouts of vigorous intensity physical activity performed as part of daily living. VILPA has been proposed as a novel concept to expand physical activity options among the least active. As a nascent area of research, factors which impede or encourage VILPA in physically inactive adults are yet to be explored. Such information is pertinent in the design of future interventions. We examined the barriers and enablers of VILPA among physically inactive adults using the Capability, Opportunity, Motivation, Behavior (COM-B) model as a conceptual framework. METHODS: We recruited a sample of self-identified physically inactive middle-aged and older adults (N = 78) based in Australia to take part in 19 online focus groups across three age groups: young-middle (age 35-44), middle (age 45-59) and old (age 60-76). We analyzed interviews using a critical realist approach to thematic analysis. Identified barriers and enablers were subsequently mapped onto the COM-B model components. RESULTS: The data generated 6 barriers and 10 enablers of VILPA that corresponded to COM-B concepts. Barriers included physical limitations (physical capability), perceptions of aging, need for knowledge (psychological capability), environmental constraints (physical opportunity), perceptions of effort and energy, and fear (automatic motivation). Enablers included convenience, reframing physical activity as purposeful movement, use of prompts and reminders (physical opportunity), normalization of taking the active option, gamification (social opportunity), sense of achievement, health improvements, personally salient rewards (reflective motivation), identity fit, and changing from effortful deliberation to habitual action (automatic motivation). CONCLUSION: The barriers and enablers of VILPA span capability, opportunity, and motivation beliefs. Promoting the time-efficient nature and simplicity of VILPA requiring no equipment or special gym sessions, the use of prompts and reminders at opportune times, and habit formation strategies could capitalize on the enablers. Addressing the suitability of the small bouts, the development of specific guidelines, addressing safety concerns, and explicating the potential benefits of, and opportunities to do, VILPA could ameliorate some of the barriers identified. Future VILPA interventions may require limited age customization, speaking to the potential for such interventions to be delivered at scale.


Asunto(s)
Ejercicio Físico , Motivación , Persona de Mediana Edad , Humanos , Anciano , Adulto , Grupos Focales , Ejercicio Físico/psicología , Conducta Sedentaria , Australia , Investigación Cualitativa
5.
Nature ; 548(7665): 66-69, 2017 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-28770838

RESUMEN

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 1013 are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 104. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

6.
Nature ; 541(7638): 506-510, 2017 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-28005057

RESUMEN

The spectrum of the hydrogen atom has played a central part in fundamental physics over the past 200 years. Historical examples of its importance include the wavelength measurements of absorption lines in the solar spectrum by Fraunhofer, the identification of transition lines by Balmer, Lyman and others, the empirical description of allowed wavelengths by Rydberg, the quantum model of Bohr, the capability of quantum electrodynamics to precisely predict transition frequencies, and modern measurements of the 1S-2S transition by Hänsch to a precision of a few parts in 1015. Recent technological advances have allowed us to focus on antihydrogen-the antimatter equivalent of hydrogen. The Standard Model predicts that there should have been equal amounts of matter and antimatter in the primordial Universe after the Big Bang, but today's Universe is observed to consist almost entirely of ordinary matter. This motivates the study of antimatter, to see if there is a small asymmetry in the laws of physics that govern the two types of matter. In particular, the CPT (charge conjugation, parity reversal and time reversal) theorem, a cornerstone of the Standard Model, requires that hydrogen and antihydrogen have the same spectrum. Here we report the observation of the 1S-2S transition in magnetically trapped atoms of antihydrogen. We determine that the frequency of the transition, which is driven by two photons from a laser at 243 nanometres, is consistent with that expected for hydrogen in the same environment. This laser excitation of a quantum state of an atom of antimatter represents the most precise measurement performed on an anti-atom. Our result is consistent with CPT invariance at a relative precision of about 2 × 10-10.

7.
Cost Eff Resour Alloc ; 20(1): 17, 2022 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-35366905

RESUMEN

BACKGROUND: Afghanistan, a low-income landlocked country, is continuously suffering from domestic war and conflicts; the country struggles to provide quality healthcare services, including affordable medicinal products in the required quantity. Moreover, the quality standards of domestic pharmaceutical companies have not been established yet. One of the internationally recognized guidelines for monitoring manufacturing processes in pharmaceutical companies is Good Manufacturing Practice (GMP), recommended by World Health Organization (WHO). Therefore, this study aimed to assess whether a pharmaceutical company in Kabul, Afghanistan adheres to the GMP standards established by WHO. METHOD: A descriptive cross-sectional study was conducted to assess the WHO-delineated GMP compliance of 25 pharmaceutical companies in Kabul, Afghanistan. The inspection checklist was developed by Afghanistan's National Medicine and Healthcare Products Regulatory Authority (NMHRA) using the WHO-delineated GMP guidelines. In addition, direct observation, interviews with respective delegates, and documentation reviews were conducted to collect research data. RESULT: Only 38.33% (1.14 ± 1.08) of GMP contents were complied. Personnel 66.67% (2 ± 1.15) and materials 58.67% (1.76 ± 1.11) were the most commonly complied components, whereas the product recall 12.98% (0.39 ± 0.85), quality assurance 16.44% (0.49 ± 0.81) and quality control laboratory 28.35% (0.85 ± 1.12) were the least complied ones. CONCLUSION: None of the GMP components was fully adhered to by the pharmaceutical companies in Kabul, Afghanistan. Quality control and assurance should be implemented immediately, including validation and qualification practices.

8.
Nature ; 529(7586): 373-6, 2016 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-26791725

RESUMEN

Antimatter continues to intrigue physicists because of its apparent absence in the observable Universe. Current theory requires that matter and antimatter appeared in equal quantities after the Big Bang, but the Standard Model of particle physics offers no quantitative explanation for the apparent disappearance of half the Universe. It has recently become possible to study trapped atoms of antihydrogen to search for possible, as yet unobserved, differences in the physical behaviour of matter and antimatter. Here we consider the charge neutrality of the antihydrogen atom. By applying stochastic acceleration to trapped antihydrogen atoms, we determine an experimental bound on the antihydrogen charge, Qe, of |Q| < 0.71 parts per billion (one standard deviation), in which e is the elementary charge. This bound is a factor of 20 less than that determined from the best previous measurement of the antihydrogen charge. The electrical charge of atoms and molecules of normal matter is known to be no greater than about 10(-21)e for a diverse range of species including H2, He and SF6. Charge-parity-time symmetry and quantum anomaly cancellation demand that the charge of antihydrogen be similarly small. Thus, our measurement constitutes an improved limit and a test of fundamental aspects of the Standard Model. If we assume charge superposition and use the best measured value of the antiproton charge, then we can place a new limit on the positron charge anomaly (the relative difference between the positron and elementary charge) of about one part per billion (one standard deviation), a 25-fold reduction compared to the current best measurement.

9.
Chaos Solitons Fractals ; 145: 110788, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33642704

RESUMEN

This paper is associated to investigate a stochastic SEIAQHR model for transmission of Coronavirus disease 2019 that is a recent great crisis in numerous societies. This stochastic pandemic model is established due to several safety protocols, for instance social-distancing, mask and quarantine. Three white noises are added to three of the main parameters of the system to represent the impact of randomness in the environment on the considered model. Also, the unique solvability of the presented stochastic model is proved. Moreover, a collocation approach based on the Legendre polynomials is presented to obtain the numerical solution of this system. Finally, some simulations are provided to survey the obtained results of this pandemic model and to identify the theoretical findings.

10.
Chaos Solitons Fractals ; 142: 110418, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33288973

RESUMEN

In this study, we propose a mathematical model about the spread of novel coronavirus. This model is a system of fractional order differential equations in Caputo's sense. The aim is to explain the virus transmission and to investigate the impact of quarantine on decreasing the prevalence rate of the virus in the environment. The unique solvability of the presented COVID-19 model is proved. Also, the equilibrium points and the reproduction number of the proposed model are discussed in two cases with and without considering the quarantine factor. Using the Adams-Bashforth-Moulton predictor-corrector method, some numerical simulations are implemented to survey the behavior of the considered model.

11.
J Intern Med ; 286(3): 268-289, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31282104

RESUMEN

The host evolves redundant mechanisms to preserve physiological processing and homeostasis. These functions range from sensing internal and external threats, creating a memory of the insult and generating reflexes, which aim to resolve inflammation. Impairment in such functioning leads to chronic inflammatory diseases. By interacting through a common language of ligands and receptors, the immune and sensory nervous systems work in concert to accomplish such protective functions. Whilst this bidirectional communication helps to protect from danger, it can contribute to disease pathophysiology. Thus, the somatosensory nervous system is anatomically positioned within primary and secondary lymphoid tissues and mucosa to modulate immunity directly. Upstream of this interplay, neurons detect danger, which prompts the release of neuropeptides initiating (i) defensive reflexes (ranging from withdrawal response to coughing) and (ii) chemotaxis, adhesion and local infiltration of immune cells. The resulting outcome of such neuro-immune interplay is still ill-defined, but consensual findings start to emerge and support neuropeptides not only as blockers of TH 1-mediated immunity but also as drivers of TH 2 immune responses. However, the modalities detected by nociceptors revealed broader than mechanical pressure and temperature sensing and include signals as various as cytokines and pathogens to immunoglobulins and even microRNAs. Along these lines, we aggregated various dorsal root ganglion sensory neuron expression profiling datasets supporting such wide-ranging sensing capabilities to help identifying new danger detection modalities of these cells. Thus, revealing unexpected aspects of nociceptor neuron biology might prompt the identification of novel drivers of immunity, means to resolve inflammation and strategies to safeguard homeostasis.


Asunto(s)
Nociceptores/fisiología , Sistema Nervioso Periférico/fisiología , Células Receptoras Sensoriales/fisiología , Citocinas/fisiología , Hipersensibilidad a las Drogas/inmunología , Exosomas/fisiología , Proteína HMGB1/fisiología , Humanos , Inmunidad Innata/fisiología , Inmunoglobulinas/fisiología , Infecciones/inmunología , Mediadores de Inflamación/fisiología , Neoplasias/fisiopatología , Neuroinmunomodulación/fisiología , Nervios Periféricos/fisiología , Tiempo de Reacción/fisiología , Estrés Mecánico , Termorreceptores/fisiología , Receptor Toll-Like 2/fisiología , Receptor Toll-Like 4/fisiología , Microambiente Tumoral/fisiología
12.
Neuropathol Appl Neurobiol ; 45(4): 380-397, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30252960

RESUMEN

AIMS: Alzheimer's disease (AD) is characterized by degeneration of cholinergic basal forebrain (CBF) neurons in the nucleus basalis of Meynert (nbM), which provides the major cholinergic input to the cortical mantle and is related to cognitive decline in patients with AD. Cortical histone deacetylase (HDAC) dysregulation has been associated with neuronal degeneration during AD progression. However, whether HDAC alterations play a role in CBF degeneration during AD onset is unknown. We investigated global HDAC protein levels and nuclear HDAC2 immunoreactivity in tissue containing the nbM, changes and their association with neurofibrillary tangles (NFTs) during the progression of AD. METHODS: We used semi-quantitative western blotting and immunohistochemistry to evaluate HDAC and sirtuin (SIRT) levels in individuals that died with a premortem clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), mild/moderate AD (mAD) or severe AD (sAD). Quantitative immunohistochemistry was used to identify HDAC2 protein levels in individual cholinergic nbM nuclei and their colocalization with the early phosphorylated tau marker AT8, the late-stage apoptotic tau marker TauC3 and Thioflavin-S, a marker of ß-pleated sheet structures in NFTs. RESULTS: In AD patients, HDAC2 protein levels were dysregulated in the basal forebrain region containing cholinergic neurons of the nbM. HDAC2 nuclear immunoreactivity was reduced in individual cholinergic nbM neurons across disease stages. HDAC2 nuclear reactivity correlated with multiple cognitive domains and with NFT formation. CONCLUSIONS: These findings suggest that HDAC2 dysregulation contributes to cholinergic nbM neuronal dysfunction, NFT pathology, and cognitive decline during clinical progression of AD.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Disfunción Cognitiva/metabolismo , Histona Desacetilasa 2/metabolismo , Ovillos Neurofibrilares/metabolismo , Enfermedad de Alzheimer/patología , Neuronas Colinérgicas/metabolismo , Disfunción Cognitiva/patología , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Ovillos Neurofibrilares/patología , Proteínas tau/metabolismo
13.
J Appl Microbiol ; 127(5): 1339-1348, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31386790

RESUMEN

AIMS: This study was conducted to evaluate the chemical composition and in vitro gas production (GP) and fermentation parameters of Quercus infectoria and Quercus libani leaves following treatment with the Klebsiella pneumoniae, a tannin-degrading bacterium. METHODS AND RESULTS: This isolate was isolated on medium containing tannic acid as the sole source of carbon and energy, and identified based on 16S rRNA sequencing analysis. In both oak leaf species (i.e. Q. infectoria and Q. libani), inoculation with Klebsiella pneumoniae significantly increased (P < 0·05) dry matter (DM) loss. For Q. libani, crude protein content was increased (P = 0·02) by bacterial treatment vs. control. In both oak leaves, total phenolic content and total tannins were decreased (P < 0·05) as a consequence of bacterial treatment. However, bacterial processing didn't changed (P > 0·05) organic matter (OM), neutral detergent fibre, acid detergent fibre or acid detergent lignin content of treated leaves. In both oak leaves the measuring parameters including GP volume, in vitro digestibility of DM and OM, estimated metabolizable energy, total volatile fatty acids, acetate, ammonia nitrogen concentration, total protozoal population and the subfamily Isotricha in treatments were higher (P < 0·05) than control. CONCLUSIONS: It can be concluded that biological treatment of Q. infectoria and Q. libani leaves with K. pneumoniae represents a useful approach to decrease their phenolic compound content and improve their nutritive value as ruminant feed. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated that biologically processing of tannin-containing by-products with K. pneumoniae could increase their nutritive value as ruminant feeds and increase animal productivity.


Asunto(s)
Alimentación Animal/microbiología , Klebsiella pneumoniae/metabolismo , Quercus/química , Quercus/microbiología , Rumiantes/fisiología , Taninos/metabolismo , Animales , Fermentación , Nutrientes/análisis , Nutrientes/metabolismo , Fenol/análisis , Fenol/metabolismo , Hojas de la Planta/química , Hojas de la Planta/microbiología , Rumiantes/microbiología , Rumiantes/parasitología , Taninos/análisis
14.
Water Sci Technol ; 79(6): 1206-1213, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31070600

RESUMEN

Combined sewer overflows (CSOs) pollute receiving waters and have a negative impact on ecosystem services. In urban areas rehabilitation of the sewer system to avoid CSOs is associated with high investment costs. Furthermore, not all CSOs can be closed due to the need for hydraulic reliability of the system. Local treatment of CSO with high rate filtration offers an alternative to rehabilitation of the sewer system that is flexible with respect to design and has lower investment cost than separating sewage and storm water runoff. Results from DESSIN, a 4-year EU demonstration project, are presented. The results showed on average 50% removal of particulate matter during CSO events, with higher removal (80%) in the initial first flush period. Other constituents, for example heavy metals, were removed through their association with particles. Potential impacts on ecosystem services in the catchment and the sustainability of the solution were assessed.


Asunto(s)
Eliminación de Residuos Líquidos/métodos , Aguas Residuales/estadística & datos numéricos , Metales Pesados/análisis , Reproducibilidad de los Resultados , Aguas del Alcantarillado , Contaminantes del Agua/análisis
15.
Phys Rev Lett ; 120(2): 025001, 2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29376718

RESUMEN

The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma's density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for stabilizing positron plasmas, as the procedures used to collect positrons from radioactive sources typically yield plasmas with variable densities and particle numbers; it also simplifies optimization studies that require plasma parameter scans. The reproducibility achieved by applying this technique to the positron and electron plasmas used by the ALPHA antihydrogen experiment at CERN, combined with other developments, contributed to a 10-fold increase in the antiatom trapping rate.

16.
Andrologia ; 2018 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-29292525

RESUMEN

The role of asymptomatic infections caused by Chlamydia trachomatis in male infertility and the efficacy of antibiotics in the treatment of this condition are not yet definitely determined. A total of 165 infertile males having abnormal semen parameters (study group) as well as 165 healthy fertile men (control group) were included. Semen samples were taken from all participants and after analysing for semen parameters, undergone real-time PCR, and reactive oxygen species (ROS) as well as total antioxidant capacity (TAC) assays. Infected individuals of study group were treated with antibiotic. One month after the treatment completion, second semen samples were taken and undergone all the tests mentioned. The frequency of C. trachomatis was significantly higher in the infertile men compared with the fertile ones (4.2% vs 0.6%). Most of the semen parameters were improved and reached their normal range, the level of TAC elevated and ROS level as well as ROS/TAC ratio reduced after antibiotic treatment. Moreover, wives of three infected infertile men (42.9%) became pregnant 4 months after the treatment completion. Our data suggest that asymptomatic infection caused by C. trachomatis is correlated with male infertility and antibiotic therapy can improve the semen quality and fairly treat the male infertility.

17.
Cell Mol Biol (Noisy-le-grand) ; 63(2): 14-19, 2017 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-28364780

RESUMEN

The position of genes along the genome is an important evolutionary factor for organizing gene regulation. Hence, transcriptional regulatory network have been studied much more extensively from gene distributions rather than other viewpoints. The systematics of intergenic distances, therefore, should be taken into account as an important source of information on the controls exerted on gene expression by various biological mechanisms. Here we study a collection of features including, intergenic and interoperonic distances, distances between isolated genes, distances between regulatory genes and distances between isolated and regulatory genes/operons in order to provide a more informative picture of gene distributions via firstly discovering the statistical model of these features. We find that all these features significantly follow the lognormal distribution. Then we test a few important biological hypotheses particularly in relation to controls exerted in the transcriptional regulatory network in a completely inferential approach using generalized p-value based on the discovered model. We find that mean distances of isolated genes significantly is less than that of regulatory genes.  These findings are consistent with the previous evidences that many biological variables, especially in relation to systems biology, follow lognormal distribution. furthermore, our results inferentially support the crucial hypothesis on the two distinct logical types of control, namely digital control (i.e. control mediated by specific transcription factors) and analog control (i.e. control mediated by distribution of supercoiling energy and based on gene neighborhood) previously proposed by studying expression patterns.


Asunto(s)
Algoritmos , Regulación de la Expresión Génica , Redes Reguladoras de Genes/genética , Modelos Genéticos , Transcripción Genética/genética , Animales , Biología Computacional/métodos , ADN Intergénico/genética , Escherichia coli/genética , Humanos , Operón/genética
18.
Herz ; 42(8): 746-751, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27928594

RESUMEN

BACKGROUND: In patients with mitral stenosis (MS), pulmonary hypertension (PH) is a significant contributor to the associated morbidity. We aimed to study factors associated with the presence of significant PH (sPH) and whether incorporating body surface area (BSA) in the mitral valve area (MVA) would improve the predictive value of the latter. METHODS: The medical records of 558 patients with severe MS undergoing percutaneous balloon mitral commissurotomy were evaluated over a period of 8 years. Factors associated with the presence of significant PH (sPH) defined as mPAP ≥ 40 mm Hg were examined. RESULTS: A total of 558 patients (423 women) were enrolled. Overall, 153 (27%) patients had sPH. Patients with sPH were similar to the rest of the subjects in terms of demographics, body habitus, blood group, and incidence of atrial fibrillation. Among echocardiographic findings, absolute MVA, indexed MVA, and mean transmitral valve gradient were associated with the presence of sPH. Transmitral valve gradient during right heart catheterization had the highest area under the curve for an association with sPH. CONCLUSION: Age, gender, heart rhythm, and blood group were not associated with the presence of sPH in severe MS. The predictive value of the indexed MVA for the presence of sPH was not higher than that of absolute MVA.


Asunto(s)
Valvuloplastia con Balón/métodos , Hipertensión Pulmonar/terapia , Estenosis de la Válvula Mitral/terapia , Cardiopatía Reumática/terapia , Adulto , Superficie Corporal , Ecocardiografía , Femenino , Hemodinámica/fisiología , Humanos , Hipertensión Pulmonar/diagnóstico , Hipertensión Pulmonar/fisiopatología , Masculino , Persona de Mediana Edad , Válvula Mitral/fisiopatología , Estenosis de la Válvula Mitral/diagnóstico , Estenosis de la Válvula Mitral/fisiopatología , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Cardiopatía Reumática/diagnóstico , Cardiopatía Reumática/fisiopatología
19.
Int Endod J ; 50(10): 951-966, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27870102

RESUMEN

This systematic review investigated the failure rate of conventional single-unit restorations in root filled posterior permanent teeth. Two reviewers independently applied eligibility criteria, extracted data and assessed the quality of the evidence of each included study according to the Cochrane Collaboration's procedures for randomized control trials (RCTs) and the STROBE criteria for observational studies. The MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Oral Health Group Trials Register and CENTRAL (via Cochrane Library) databases were searched electronically (January 1993 to week 1, February 2015). This was complemented by an additional hand search of selected journals and the references of relevant studies. Clinical studies published on root filled single-unit restorative treatments with a mean follow-up period of at least 3 years were selected. The outcome measured was clinical or radiological failure. Overall, the four RCTs and the single observational study included were of low and high quality, respectively. Therefore, a meta-analysis was not possible. The pooled mean failure rates were reported according to the type of treatment and remaining coronal tooth structure. The current evidence suggested that the failure rates of the treatments may depend on the amount of remaining tooth structure and type of treatment. Post-retained crowns were associated with the most favourable outcome in teeth with one to two remaining coronal tooth wall(s), whereas post-free crowns were superior when greater tooth structure was available. Restorations in teeth without ferrules had such a high rate of failure that other treatment options should be considered.


Asunto(s)
Fracaso de la Restauración Dental , Restauración Dental Permanente , Diente no Vital/terapia , Restauración Dental Permanente/métodos , Humanos
20.
East Mediterr Health J ; 22(11): 794-801, 2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-28177109

RESUMEN

The present descriptive-comparative study was conducted to give an overview of the messaging standards that are necessary for interoperable electronic health records (EHRs). We designed a preliminary model after data collection and compared the messaging standards of Health Level Seven (HL7) and the International Organization for Standardization (ISO). The data were assessed with the Delphi technique. A comprehensive model for the messaging standards of EHRs in the Islamic Republic of Iran was presented in three pivots: structural characteristics (standard for all EHRs, XML-based and object-oriented messages, and dual model); model specifications (reference model, archetypes and classes of reference model), and general features (distinct ontology, mapping with other standards, and using reference archetypes for exchanging documents). In conclusion, we gave an overview of messaging standards for the interoperability of EHRs and experts selected ISO13606 as a suitable standard for the Islamic Republic of Iran.


Asunto(s)
Comunicación , Registros Electrónicos de Salud/normas , Técnica Delphi , Estándar HL7 , Irán
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