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1.
Int J Gynecol Cancer ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514101

RESUMO

BACKGROUND: Ovarian cancer with extensive metastatic disease involving pelvic structures often requires rectosigmoid resection for complete gross resection; however, it is associated with increased surgical morbidity. There are limited data, and none in ovarian cancer, on near-infrared assessment of perfusion in rectosigmoid resections with anastomosis. PRIMARY OBJECTIVE: To compare the rate of pelvic complications (pelvic abscesses, anastomotic leaks, and infections) within 30 days of surgery with and without near-infrared assessment of perfusion at time of rectosigmoid resection and re-anastomosis in patients undergoing cytoreductive surgery for ovarian cancer. STUDY HYPOTHESIS: We hypothesize the use of near-infrared technology (intravenous indocyanine green and endoscopic near-infrared fluorescence imaging), compared with standard intra-operative assessment, to evaluate anastomotic perfusion at time of rectosigmoid resection and re-anastomosis will result in lower rates of post-operative pelvic complications. TRIAL DESIGN: This is a planned multicenter randomized controlled trial. Patients who undergo rectosigmoid resection as part of their ovarian cytoreductive surgery will be randomized 1:1 to standard assessment of anastomosis with the surgeon's usual technique (control arm) or assessment with near-infrared angiography using indocyanine green and endoscopic fluorescence imaging (experimental arm). Randomization will occur after rectosigmoid resection has been completed and the surgeon declares their plan to create a diverting ostomy. Randomization will be stratified by plan for diverting ostomy. MAJOR INCLUSION/EXCLUSION CRITERIA: Main inclusion criteria include patients with primary or recurrent ovarian, fallopian tube, or primary peritoneal cancer who are scheduled for cytoreductive surgery with suspected need for low-anterior rectosigmoid resection. PRIMARY ENDPOINT: Rate of 30-day post-operative pelvic complications. SAMPLE SIZE: 310 (155 per arm) ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Q2 2027 and Q4 2027, respectively. TRIAL REGISTRATION: NCT04878094.

2.
Sci Adv ; 9(42): eadj0360, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37862408

RESUMO

We extend the t-z mapping of time-dependent paraxial optics by engineering a synthetic magnetic vector potential, leading to a nontrivial band topology. We consider an inhomogeneous 1D array of coupled optical waveguides and show that the wave equation describing paraxial propagation of optical pulses can be recast as a Schrödinger equation, including a synthetic magnetic field whose strength can be controlled via the spatial gradient of the waveguide properties across the array. We use an experimentally motivated model of a laser-written array to demonstrate that this synthetic magnetic field can be engineered in realistic setups and can produce interesting physics such as cyclotron motion, a controllable Hall drift of the pulse in space or time, and propagation in chiral edge states. These results substantially extend the physics that can be explored within propagating geometries and pave the way for higher-dimensional topological physics and strongly correlated fluids of light.

3.
World Neurosurg ; 178: e819-e827, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37574192

RESUMO

PURPOSE: We aimed to catalog past and present clinical trials on immunotherapy treatments for glioblastoma (GBM) and discover relevant trends in this field. METHODS: Former and ongoing clinical trials involving the use of immunotherapy to treat GBM were queried in July 2022 within the clinicaltrials.gov registry (https://clinicaltrials.gov/). Pertinent trials were categorized by variables including immunotherapy classification, tumor type (newly diagnosed versus recurrent), country of origin, start date, clinical phase, study completion status, estimated subject enrollment, design, publication status, and funding source. RESULTS: A list of 173 trials was identified in total. The number of immunotherapy clinical trials to treat GBM has increased over time. The largest proportion of trials were gene therapies (97 studies; 56.1%) and viral therapies (37 studies; 21.4%). Studies were designated as a biologic (45.1%), drug (43.9%), genetic (2.3%), or procedure (1.2%). Trials spanned 19 countries; China, the second largest contributor (5.8%) after the United States (70.0%), has increased clinical trial development in the past years. The average time to completion was 52.3 months. Trials were primarily funded by academic centers; however, one-fourth of the trials were funded by industry and 2 were funded by foundations. One-t of the trials were active and over one-third were linked to publications. CONCLUSIONS: Our findings provide a comprehensive summary of the state of immunotherapy clinical trials for GBM, highlighting the evolving nature and growing scope of this field.


Assuntos
Glioblastoma , Humanos , Estados Unidos , Glioblastoma/terapia , Imunoterapia , Projetos de Pesquisa , Sistema de Registros , China
4.
Phys Rev E ; 107(6-1): 064211, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37464675

RESUMO

Non-Hermitian two-site dimers serve as minimal models in which to explore the interplay of gain and loss in dynamical systems. In this paper, we experimentally and theoretically investigate the dynamics of non-Hermitian dimer models with nonreciprocal hoppings between the two sites. We investigate two types of non-Hermitian couplings; one is when asymmetric hoppings are externally introduced, and the other is when the nonreciprocal hoppings depend on the population imbalance between the two sites, thus introducing the non-Hermiticity in a dynamical manner. We engineer the models in our synthetic mechanical setup comprised of two classical harmonic oscillators coupled by measurement-based feedback. For fixed nonreciprocal hoppings, we observe that, when the strength of these hoppings is increased, there is an expected transition from a PT-symmetric regime, where oscillations in the population are stable and bounded, to a PT-broken regime, where the oscillations are unstable and the population grows/decays exponentially. However, when the non-Hermiticity is dynamically introduced, we also find a third intermediate regime in which these two behaviors coexist, meaning that we can tune from stable to unstable population dynamics by simply changing the initial phase difference between the two sites. As we explain, this behavior can be understood by theoretically exploring the emergent fixed points of a related dimer model in which the nonreciprocal hoppings depend on the normalized population imbalance. Our study opens the way for the future exploration of non-Hermitian dynamics and exotic lattice models in synthetic mechanical networks.

5.
Cureus ; 15(5): e38798, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37303341

RESUMO

Isolated limb weakness (monoparesis) has many possible etiologies. Although often assumed to be of a peripheral cause, it can be of central origin. This article describes a case from the Emergency Department of left lower limb weakness in a walk-in male patient on no medications, who had a 50-pack-year smoking history, type II diabetes, and asymptomatic atrial fibrillation. The patient had no history of previous episodes or trauma. His vitals were normal, and his speech and facial function were intact. The patient had full function of his upper limbs, no sensory deficits, and equal reflexes bilaterally. The singular clinical finding was decreased strength in the left leg compared to the right. Imaging revealed a right frontal intraparenchymal hemorrhage, which remained stable throughout his hospital admission. His muscle weakness was significantly improved upon discharge. In general, strokes can present with a variety of symptoms, which increase the risk of misdiagnosis. Monoparesis can be the singular sign of a stroke, and it is more common in the upper than the lower limbs.

6.
Int J Surg Case Rep ; 100: 107741, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36265425

RESUMO

INTRODUCTION AND IMPORTANCE: Diagnosis of a smooth muscle tumor of uncertain malignant potential (STUMP) during pregnancy is rare. Furthermore; the investigation of an intra-abdominal mass during pregnancy is clinically challenging due to anatomical changes and additional considerations of the developing fetus and radiation exposure. The unusual nature and diagnostic dilemma of such a case warrants a case report to serve as an educational prompt to clinicians who may encounter pregnant patients with undifferentiated intra-abdominal masses and/or suspecting of STUMP. CASE PRESENTATION: We report a rare case of a parasitic STUMP diagnosed during pregnancy. The patient presented with a new umbilical hernia and deranged liver function tests (LFT's) during her third trimester. MRI reported a large mass in the left mid flank with intra-abdominal varices extending into the umbilical hernia. She went on to develop an acute abdomen requiring laparotomy where a parasitic fibroid adherent to the omentum was excised and a preterm infant was delivered via caesarean section. Histology was difficult due to pregnancy related changes but ultimately confirmed a diagnosis of STUMP. CLINICAL DISCUSSION: STUMP in pregnancy is rare and diagnosis is further complicated by histological challenges due to pregnancy related changes. Postoperative diagnosis is challenging due to lack of universally accepted diagnostic criteria and Uncertainty regarding prognostic factors makes management and follow-up of patients with STUMP challenging. Studies have shown that younger patients are more likely to demonstrate recurrence. CONCLUSION: Investigation and management of intra-abdominal masses in pregnancy is challenging. It requires timely multi-disciplinary team (MDT) input. Additional complications and considerations relate to the preterm fetus. Knowledge and understanding of these difficulties will better equip clinicians working with such patients to formulate a structured and well informed approach to the pregnant patient with a new intra-abdominal mass. Diagnosis of STUMP during pregnancy may be challenging for the pathologist and require further exert opinion.

7.
J Anim Sci ; 100(8)2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35727741

RESUMO

Pork hot carcass weights (HCW) have been increasing 0.6 kg per year, and if they continue to increase at this rate, they are projected to reach an average weight of 118 kg by the year 2050. This projection in weight is a concern for pork packers and processors given the challenges in product quality from heavier carcasses of broiler chickens. However, previous work demonstrated that pork chops from heavier carcasses were more tender than those from lighter carcasses. Therefore, the objective was to determine the effects of pork hot carcass weights, ranging from 90 to 145 kg with an average of 119 kg, on slice shear force and sensory traits of Longissimus dorsi chops when cooked to 63 or 71 °C, and to assess if differences in chilling rate can explain differences in sensory traits. Carcasses were categorized retrospectively into fast, medium, or slow chilling-rates based on their chilling rate during the first 17 h postmortem. Loin chops cut from 95 boneless loins were cooked to either 63 or 71 °C and evaluated for slice shear force and trained sensory panel traits (tenderness, juiciness, and flavor) using two different research laboratories. Slopes of regression lines and coefficients of determination between HCW and sensory traits were calculated using the REG procedure in SAS and considered different from 0 at P ≤ 0.05. As hot carcass weight increased, chops became more tender as evidenced by a decrease in SSF (63 °C ß = -0.0412, P = 0.01; 71 °C ß = -0.1005, P < 0.001). Furthermore, HCW explained 25% (R2 = 0.2536) of the variation in chilling rate during the first 5 h of chilling and 32% (R2 = 0.3205) of the variation in chilling rate from 5 to 13 h postmortem. Slow- and medium-rate chilling carcasses were approximately 12 kg heavier (P < 0.05) than fast chilling carcasses. Slice shear force of chops cooked to 63 and 71 °C was reduced in slow and medium chilling compared with fast chilling carcasses. Carcass temperature at 5 h postmortem explained the greatest portion of variation (R2 = 0.071) in slice shear force of chops cooked to 63 °C. These results suggest that carcasses tend to chill slower as weight increases, which resulted in slight improvements in sensory traits of boneless pork chops regardless of final degree of doneness cooking temperature.


Pork carcass weights have increased year over year for at least the past 25 yr. The poultry industry has experienced similar increases in carcass weights in the recent past. The increases in broiler carcass weights have resulted in detrimental impacts on quality. Contrary to the poultry industry, increases in pork carcass weights have resulted in a general improvement in pork quality, including tenderness. The underlying cause of these improvements has not been explained. In the present study, chilling rate was associated with carcass weights, particularly during the first 5 h postmortem. In fact, carcass temperature measured in the Longissimus dorsi muscle at 5 h postmortem was the most predictive of instrumental tenderness values when boneless pork chops were cooked according to UDSA guidelines for whole-muscle pork products. The metabolic conversion of muscle to meat is most active during this initial chilling period. Therefore, chilling rate, which is associated with carcass weight, may be influencing the conversion of muscle to meat and provide some explanation as to why heavy carcasses result in more tender pork chops.


Assuntos
Carne de Porco , Carne Vermelha , Animais , Galinhas , Culinária/métodos , Carne , Carne Vermelha/análise , Estudos Retrospectivos , Suínos
8.
Phys Rev Lett ; 127(16): 163901, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34723580

RESUMO

Hydrodynamic phenomena can be observed with light thanks to the analogy between quantum gases and nonlinear optics. In this Letter, we report an experimental study of the superfluid-like properties of light in a (1+1)-dimensional nonlinear optical mesh lattice, where the arrival time of optical pulses plays the role of a synthetic spatial dimension. A spatially narrow defect at rest is used to excite sound waves in the fluid of light and measure the sound speed. The critical velocity for superfluidity is probed by looking at the threshold in the deposited energy by a moving defect, above which the apparent superfluid behavior breaks down. Our observations establish optical mesh lattices as a promising platform to study fluids of light in novel regimes of interdisciplinary interest, including non-Hermitian and/or topological physics.

10.
Foods ; 11(1)2021 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-35010231

RESUMO

The objective was to determine the effects of sous-vide cooking and degree of doneness on consumer eating experience of pork chops when cooked color was expected to differ. The hypothesis was consumers would prefer a cooked brown color and would rate grilled chops more acceptable than sous-vide chops. Chops were cooked to 63 °C or 71 °C using either an open-hearth grill or a sous-vide device. Participants evaluated four samples for tenderness, juiciness, flavor, and overall acceptability. Participants rated a greater percentage of chops cooked sous-vide at 63 °C as tender (82.82%), juicy (55.83%) and acceptable (60.34%) compared with all other cooking method and degree of doneness combinations. Participants rated a greater percentage of sous-vide chops as tender and acceptable compared to grilled chops. Participants rated a greater percentage of chops cooked to 63 °C as tender, juicy, flavorful, and acceptable when compared to 71 °C. Even when participants could visualize cooked color, they preferred chops cooked to 63 °C compared with chops cooked to 71 °C. Overall, participants preferred chops cooked to 63 °C compared to 71 °C regardless of the cooking method and preferred chops cooked to 63 °C using the sous-vide cooking method the most among all treatments.

11.
BMC Health Serv Res ; 20(1): 1131, 2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33292194

RESUMO

BACKGROUND: Medicines are one of the most common healthcare interventions, yet evidence shows patients often do not receive the information they want about their medicines. This affects their adherence and healthcare engagement. There is limited research exploring what information patients want about their medicines, from whom and in what format. The aim of this study was to determine the medicines information needs of patients admitted to the general medical service of a large New Zealand (NZ) hospital, and identify the barriers and enablers to meeting these needs. METHODS: A descriptive exploratory approach using semi-structured interviews was used to understand the needs and preferences of patients for information about their regular medicines and the barriers and facilitators to obtaining this information. Patients admitted to a general medical ward at a large NZ hospital, aged 18 years and over, prescribed one or more regular medicines, and self-managing their own medicines prior to hospitalisation were included. Semi-structured interviews were conducted with each participant (n = 30) and transcribed, then analysed using a general inductive thematic analysis approach. RESULTS: Five overarching themes captured the medicines information needs of patients: (1) autonomy; (2) fostering relationships; (3) access; (4) communication; and (5) minimal information needs. Patients desired information to facilitate their decision-making and self-management of their health. Support people, written information, and having good relationships with health providers enabled this. Having access to information at the right time, communicated in a clear and consistent way with opportunities for follow-up, was important. A significant portion of participants were satisfied with receiving minimal information and had no expectations of needing more medicines information. CONCLUSIONS: Although patients' medicines information needs varied between individuals, the importance of receiving information in an accessible, timely manner, and having good relationships with health providers, were common to most. Considering these needs is important to optimise information delivery in general medical patients.


Assuntos
Pacientes Internados , Preparações Farmacêuticas , Adolescente , Adulto , Comunicação , Hospitais , Humanos , Nova Zelândia
12.
Transl Anim Sci ; 4(2): txaa065, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32705060

RESUMO

A total of 976 pigs (PIC 327 × Camborough; PIC, Hendersonville, TN; initially 22.0 ± 1.53 kg body weight [BW]) were used in a 160-d growth study to evaluate the effects of increasing space allowance and varying marketing strategies on growth performance of pigs raised to market weights of ~165 kg. Pens of pigs were blocked by location within the barn and allotted to one of six treatments. Pen served as the experimental unit, and there were eight replicate pens per treatment. The first four treatments consisted of increased initial stocking density and did not utilize topping strategies: (1) 14 pigs/pen (1.17 m2/pig), (2) 17 pigs/pen (0.97 m2/pig), (3) 20 pigs/pen (0.82 m2/pig), and (4) 23 pigs/pen (0.71 m2/pig). The fifth treatment began with 25 pigs/pen (0.66 m2/pig) and had four marketing events with the heaviest 3 pigs/pen removed on day 93, and additional pigs removed to a common inventory of 20 pigs/pen on day 122 and 17 pigs/pen on day 147 with final marketing on day 160. The final treatment began the experiment with 23 pigs/pen (0.71 m2/pig) with three marketing events to achieve a common inventory of 20 pigs/pen on day 108 and 17 pigs/pen on day 147. Pens of pigs were weighed and feed disappearance measured on days 0, 55, 93, 108, 122, 135, 147, and 160. As space allowance decreased from 1.17 to 0.71 m2/pig via increased initial pen inventory (treatments 1 to 4), overall average daily gain (ADG) and average daily feed intake (ADFI) decreased (linear, P < 0.001), while gain:feed ratio (G:F) did not differ (P > 0.05). The treatments with multiple marketing events were compared with each other and with the treatment that began with 0.71 m2/pig and only marketed once at the end of the study. Overall ADG and ADFI were not different (P > 0.05) among these three treatments. Marketing pigs three or four times improved (P < 0.05) G:F compared with the treatment that began the study with 0.71 m2/pig and marketed only once. Reducing floor space allowance for heavy weight pigs decreased intake, which resulted in lower growth rate and final BW, with these reductions occurring before the critical k-value was reached. Total weight gain per pen was maximized with the lowest space allowance and the multiple marketing treatments. Thus, strategic use of pig removals prior to final marketing may allow producers to maximize both number of pigs and total weight marketed through a barn when feeding to heavy weights.

13.
Nat Commun ; 11(1): 2356, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398727

RESUMO

The classification of topological insulators predicts the existence of high-dimensional topological phases that cannot occur in real materials, as these are limited to three or fewer spatial dimensions. We use electric circuits to experimentally implement a four-dimensional (4D) topological lattice. The lattice dimensionality is established by circuit connections, and not by mapping to a lower-dimensional system. On the lattice's three-dimensional surface, we observe topological surface states that are associated with a nonzero second Chern number but vanishing first Chern numbers. The 4D lattice belongs to symmetry class AI, which refers to time-reversal-invariant and spinless systems with no special spatial symmetry. Class AI is topologically trivial in one to three spatial dimensions, so 4D is the lowest possible dimension for achieving a topological insulator in this class. This work paves the way to the use of electric circuits for exploring high-dimensional topological models.

14.
J Atten Disord ; 24(7): 1002-1010, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-28800715

RESUMO

Objective: We examined differences between those with and without ADHD symptoms on resting state electroencephalography (EEG) indices and unique relations with sluggish cognitive tempo (SCT) symptoms. Method: Children with ADHD symptoms (n = 21) and healthy controls (n = 20) were assessed using rating scales, a neuropsychological task measuring sustained attention and inhibitory control, and EEG activity during a resting state period. Between-group, correlational, and regression analyses were conducted. Results: Large differences (particularly for theta/beta ratio in frontal and frontocentral regions) were found on EEG measures between those with and without ADHD symptoms. While ADHD and SCT symptoms both related to sustained attention on a computerized task, only ADHD symptoms were related to frontal and frontocentral theta/beta ratio. Conclusion: Results support the conclusion that ADHD symptoms are strongly associated with theta/beta ratio in frontal and frontocentral regions. Future studies should explore unique neurophysiological correlates of SCT.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtornos Cognitivos , Atenção , Criança , Cognição , Eletroencefalografia , Humanos
15.
Eur J Obstet Gynecol Reprod Biol ; 240: 62-67, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31229725

RESUMO

OBJECTIVE: To evaluate the value of fetal scalp blood sampling (FBS) as an adjunct test to cardiotocography, to predict adverse neonatal outcomes. STUDY DESIGN: A multicentre service evaluation observational study in forty-four maternity units in the UK. We collected data retrospectively on pregnant women with singleton pregnancy who received FBS in labour using a standardised data collection tool. The primary outcome was prediction of neonatal acidaemia diagnosed as umbilical cord arterial pH < 7.05, the secondary outcomes were the prediction of Apgar scores<7 at 1st and 5th minutes and admission to the neonatal intensive care unit (NICU). We evaluated the correlation between the last FBS blood gas before birth and the umbilical cord blood and adjusted for time intervals. We constructed 2 × 2 tables to calculate the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) and generated receiver operating curves to report on the Area Under the Curve (AUC). RESULTS: In total, 1422 samples were included in the analysis; pH values showed no correlation (r = 0.001, p = 0.9) in samples obtained within an hour (n = 314), or within half an hour from birth (n = 115) (r=-0.003, p = 0.9). A suboptimal FBS pH value (<7.25) had a poor sensitivity (22%) and PPV (4.9%) to predict neonatal acidaemia with high specificity (87.3%) and NPV (97.4%). Similar performance was noted to predict Apgar scores <7 at 1st (sensitivity 14.5%, specificity 87.5%, PPV 23.4%, NPV 79.6%) and 5th minute (sensitivity 20.3%, specificity 87.4%, PPV 7.6%, NPV 95.6%), and admission to NICU (sensitivity 20.3%, specificity 87.5%, PPV 13.3%, NPV 92.1%). The AUC for FBS pH to predict neonatal acidaemia was 0.59 (95%CI 0.59-0.68, p = 0.3) with similar performance to predict Apgar scores<7 at 1st minute (AUC 0.55, 95%CI 0.51-0.59, p = 0.004), 5th minute (AUC 0.55, 95%CI 0.48-0.62, p = 0.13), and admission to NICU (AUC 0.58, 95%CI 0.52-0.64, p = 0.002). Forty-one neonates had acidaemia (2.8%, 41/1422) at birth. There was no significant correlation in pH values between the FBS and the umbilical cord blood in this subgroup adjusted for sampling time intervals (r = 0.03, p = 0.83). CONCLUSIONS: As an adjunct tool to cardiotocography, FBS offered limited value to predict neonatal acidaemia, low Apgar Scores and admission to NICU.


Assuntos
Acidose/diagnóstico , Sofrimento Fetal/diagnóstico , Resultado da Gravidez , Acidose/sangue , Gasometria , Feminino , Sangue Fetal , Sofrimento Fetal/sangue , Humanos , Concentração de Íons de Hidrogênio , Recém-Nascido , Trabalho de Parto , Masculino , Gravidez , Estudos Retrospectivos , Couro Cabeludo , Reino Unido
16.
Nature ; 553(7686): 55-58, 2018 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-29300006

RESUMO

The discovery of topological states of matter has greatly improved our understanding of phase transitions in physical systems. Instead of being described by local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example is the two-dimensional (2D) integer quantum Hall effect: it is characterized by the first Chern number, which manifests in the quantized Hall response that is induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional (4D) systems leads to the appearance of an additional quantized Hall response, but one that is nonlinear and described by a 4D topological invariant-the second Chern number. Here we report the observation of a bulk response with intrinsic 4D topology and demonstrate its quantization by measuring the associated second Chern number. By implementing a 2D topological charge pump using ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small cloud of atoms as a local probe, we fully characterize the nonlinear response of the system via in situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probing higher-dimensional quantum Hall systems, in which additional strongly correlated topological phases, exotic collective excitations and boundary phenomena such as isolated Weyl fermions are predicted.

17.
Mater Sci Eng C Mater Biol Appl ; 69: 1036-42, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27612800

RESUMO

Light Curing Units (LCUs) are used daily in almost every dental office to photocure resins, but because the light is so bright, the user is unable to tell visually if there are any differences between different LCUs. This study evaluated the light output from six dental LCUs: Elipar Deep Cure-S (3M ESPE), Bluephase G2 (Ivoclar Vivadent), Translux 2Wave (Heraeus Kulzer), Optilight Prime (Gnatus), Slim Blast (First Medica) and Led.B (Guilin Woodpecker) with a fully charged battery, after 50, and again after 100, 20second light exposures. For each situation, the radiant power was measured 10 times with a laboratory-grade power meter. Then, the emission spectrum was measured using a fiber-optic spectrometer followed by an analysis of the light beam profile. It was found there were significant differences in the LCU power and the irradiance values between the LCUs (p<0.01). The Optilight Prime and Slim Blast LCUs showed a significant reduction in light output after a 50 and 100 exposures, while Bluephase G2 exhibited a significant reduction only after 100 exposures (p<0.01). The Bluephase G2 and Translux 2Wave delivered an emission spectrum that had two distinct wavelength emission peaks. Only the Elipar Deep Cure-S and Bluephase G2 LCUs displayed homogeneous light beam profiles, the other LCUs exhibited highly non-homogeneous light beam profiles. It was concluded that contemporary LCUs could have very different light output characteristics. Both manufacturers and researchers should provide more information about the light output from LCUs.


Assuntos
Lâmpadas de Polimerização Dentária , Fontes de Energia Elétrica , Luz , Espectrometria de Fluorescência , Estatística como Assunto
18.
Phys Chem Chem Phys ; 18(28): 19207-16, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27364512

RESUMO

The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes-Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle.

19.
Int J Lang Commun Disord ; 51(6): 703-714, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27150499

RESUMO

BACKGROUND: Phonological memory (PM) plays a significant role in language development but is impaired in individuals with Down syndrome (DS). Without formal recommendations on how to address PM limitations in clients with DS, it is possible speech-language pathologists (SLPs) find ways to do so in their practices. AIMS: This study asked if and how SLPs address PM in language therapy with clients who have DS. It also asked about SLPs' opinions of the importance, practicality and difficulty of addressing PM in clients with DS. METHODS & PROCEDURES: SLPs participated in an online survey that asked if they address PM in clients with DS and, if so, how often and with which techniques. The survey also asked SLPs to rate their opinions of addressing PM in clients with DS with Likert scales. To contrast clients with DS, SLPs were asked about their practices and opinions with clients who have specific language impairment (SLI) and autism spectrum disorders (ASD). SLPs were recruited through e-mails sent from state organizations and researchers. To compare SLPs' practices and opinions across client types, frequency analyses and analyses of variance (ANOVAs) were run. OUTCOMES & RESULTS: In all, 290 SLPs from 28 states completed the survey. Nearly all SLPs were currently practising at the time data were collected, and all worked with at least one of the three client types. Findings indicated SLPs less often addressed PM and used less variety when addressing PM with clients who have DS compared with clients who have SLI or ASD. Further, SLPs considered it less important, less practical and more difficult to address PM in clients who have DS when compared with clients who have SLI, whereas a similar pattern was found with clients who have ASD. CONCLUSIONS & IMPLICATIONS: SLPs' opinions could be one reason they under-address PM with clients who have DS. Other reasons include there are no evidence-based practice (EBP) guidelines on this topic, and there is not enough familiarity with the DS phenotype among SLPs. Future research on ways to address PM in clients with DS successfully are essential so that EBP guidelines can be established and language therapy can be made more effective.


Assuntos
Síndrome de Down/reabilitação , Terapia da Linguagem , Fala , Humanos , Patologistas , Patologia da Fala e Linguagem
20.
Chem Sci ; 6(8): 4876-4883, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28717493

RESUMO

Secondary organic material (SOM) constitutes a large mass fraction of atmospheric aerosol particles. Understanding its impact on climate and air quality relies on accurate models of interactions with water vapour. Recent research shows that SOM can be highly viscous and can even behave mechanically like a solid, leading to suggestions that particles exist out of equilibrium with water vapour in the atmosphere. In order to quantify any kinetic limitation we need to know water diffusion coefficients for SOM, but this quantity has, until now, only been estimated and has not yet been measured. We have directly measured water diffusion coefficients in the water soluble fraction of α-pinene SOM between 240 and 280 K. Here we show that, although this material can behave mechanically like a solid, at 280 K water diffusion is not kinetically limited on timescales of 1 s for atmospheric-sized particles. However, diffusion slows as temperature decreases. We use our measured data to constrain a Vignes-type parameterisation, which we extend to lower temperatures to show that SOM can take hours to equilibrate with water vapour under very cold conditions. Our modelling for 100 nm particles predicts that under mid- to upper-tropospheric conditions radial inhomogeneities in water content produce a low viscosity surface region and more solid interior, with implications for heterogeneous chemistry and ice nucleation.

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