We explore phase transitions of polariton wave packets, first, to a soliton and then to a standing wave polariton condensate in a multimode microwire system, mediated by nonlinear polariton ...interactions. At low excitation density, we observe ballistic propagation of the multimode polariton wave packets arising from the interference between different transverse modes. With increasing excitation density, the wave packets transform into single-mode bright solitons due to effects of both intermodal and intramodal polariton-polariton scattering. Further increase of the excitation density increases thermalization speed, leading to relaxation of the polariton density from a solitonic spectrum distribution in momentum space down to low momenta, with the resultant formation of a nonequilibrium condensate manifested by a standing wave pattern across the whole sample.
Exciton-polaritons in semiconductor microcavities form a highly nonlinear platform to study a variety of effects interfacing optical, condensed matter, quantum and statistical physics. We show that ...the complex polariton patterns generated by picosecond pulses in microcavity wire waveguides can be understood as the Cherenkov radiation emitted by bright polariton solitons, which is enabled by the unique microcavity polariton dispersion, which has momentum intervals with positive and negative group velocities. Unlike in optical fibres and semiconductor waveguides, we observe that the microcavity wire Cherenkov radiation is predominantly emitted with negative group velocity and therefore propagates backwards relative to the propagation direction of the emitting soliton. We have developed a theory of the microcavity wire polariton solitons and of their Cherenkov radiation and conducted a series of experiments, where we have measured polariton-soliton pulse compression, pulse breaking and emission of the backward Cherenkov radiation.
We report on the spin properties of bright polariton solitons supported by an external pump to compensate losses. We observe robust circularly polarized solitons when a circularly polarized pump is ...applied, a result attributed to phase synchronization between nondegenerate TE and TM polarized polariton modes at high momenta. For the case of a linearly polarized pump, either σ+ or σ- circularly polarized bright solitons can be switched on in a controlled way by a σ+ or σ- writing beam, respectively. This feature arises directly from the widely differing interaction strengths between co- and cross-circularly polarized polaritons. In the case of orthogonally linearly polarized pump and writing beams, the soliton emission on average is found to be unpolarized, suggesting strong spatial evolution of the soliton polarization. The observed results are in agreement with theory, which predicts stable circularly polarized solitons and unstable linearly polarized solitons.
We report propagating bound microcavity polariton soliton arrays consisting of multipeak structures either along (x) or perpendicular (y) to the direction of propagation. Soliton arrays of up to five ...solitons are observed, with the number of solitons controlled by the size and power of the triggering laser pulse. The breakup along the x direction occurs when the effective area of the trigger pulse exceeds the characteristic soliton size determined by polariton-polariton interactions. Narrowing of soliton emission in energy-momentum space indicates phase locking between adjacent solitons, consistent with numerical modeling which predicts stable multihump soliton solutions. In the y direction, the breakup originates from inhomogeneity across the wave front in the transverse direction which develops into a stable array only in the solitonic regime via phase-dependent interactions of propagating fronts.
Optical solitons are an ideal platform for the implementation of communication lines, since they can be packed extremely close one to another without risking partial loss of the encoded information ...due to their interaction. On the other hand, soliton-soliton interactions are needed to implement computations and achieve all-optical information processing. Here, we study how bright dissipative polariton solitons interact and exploit their interaction to implement and and OR gates with state of the art technology. Moreover, we show that the soliton-soliton interaction can be used to determine the sign of alpha2, the parameter describing the interaction between polaritons with opposite spin.
Painful experiences in neonates range from all newborns receiving routine vitamin K injections at birth to the critically ill preterm neonates who may experience up to 488 painful procedures during ...their stay in neonatal intensive care units. 4 5 The idea that neonates do not experience pain has long been refuted, and doctors are now more likely to administer routine pain relief. 6 The provision of adequate analgesia and sedation has been proved to maintain physiological stability and improve clinical outcomes in these patients. 7 Neonates undergoing surgery often need to be intubated and ventilated for prolonged periods after the operation. Before it can be used though, we need to know about the physiological and behavioural effects of methadone administration in the newborn and how it is eliminated, in both the term and preterm. ...this information is available, it should only be used in a research protocol.
Background
Recommendations for mastectomy by multidisciplinary teams (MDTs) may contribute to variation in mastectomy rates. The primary aim of this multicentre prospective observational study was to ...describe current practice in MDT decision‐making for recommending mastectomy. A secondary aim was to determine factors contributing to variation in mastectomy rates.
Methods
Consecutive patients undergoing mastectomy between 1 June 2015 and 29 February 2016 at participating units across the UK were recruited. Details of neoadjuvant systemic treatment (NST), operative and oncological data, and rationale for recommending mastectomy by MDTs were collected.
Results
Overall, 1776 women with breast cancer underwent 1823 mastectomies at 68 units. Mastectomy was advised by MDTs for 1402 (76·9 per cent) of these lesions. The most common reasons for advising mastectomy were large tumour to breast size ratio (530 women, 29·1 per cent) and multicentric disease (372, 20·4 per cent). In total, 202 postmenopausal women with oestrogen receptor‐positive (ER+) unifocal tumours were advised mastectomy and not offered NST, owing to large tumour to breast size ratio in 173 women (85·6 per cent). Seventy‐five women aged less than 70 years with human epidermal growth factor receptor 2‐positive (HER2+) tumours were advised mastectomy and not offered NST, owing to large tumour to breast size ratio in 45 women (60 per cent).
Conclusion
Most mastectomies are advised for large tumour to breast size ratio, but there is an inconsistency in the use of NST to downsize tumours in patients with large ER+ or HER2+ cancers. The application of standardized recommendations for NST could reduce the number of mastectomies advised by MDTs.
Antecedentes
Las recomendaciones para la mastectomía por equipos multidisciplinarios (multidisciplinary teams, MDTs) podrían contribuir a explicar la diferencia en las tasas de mastectomía. El objetivo primario de este estudio observacional prospectivo y multicéntrico fue describir la práctica actual en la toma de decisiones de los MDT para recomendar la mastectomía. El objetivo secundario fue determinar factores que contribuyen a la variación en las tasas de mastectomía.
Métodos
Se reclutaron pacientes consecutivas sometidas a mastectomía entre el 1 de junio de 2015 y el 29 de febrero de 2016 en las unidades participantes de todo el Reino Unido. Se recogieron datos del preoperatorio, tratamiento neoadyuvante sistémico (neoadjuvant systemic treatment, NST), quirúrgicos y oncológicos, así como la justificación de los MDT para recomendar la mastectomía.
Resultados
Un total de 1.776 pacientes fueron sometidas a 1.823 mastectomías en 68 unidades. La mastectomía fue recomendada por los MDTs en 1.402 (76,9%) de estas mujeres. Las razones más frecuentes para recomendar la mastectomía fueron la elevada proporción entre el tamaño del tumor y el de la mama (530; 29,1%) y la enfermedad multicéntrica (372; 20,4%). En total, a 202 mujeres postmenopáusicas con tumores unifocales positivos para receptores de estrógenos (ER+) se les recomendó la mastectomía y no se les ofreció NST; debido a una elevada proporción entre el tamaño del tumor y de la mama en 173 (86%) pacientes. A 75 mujeres de < 70 años con tumores positivos para el human epidermal growth factor receptor 2 (HER2+) se les recomendó la mastectomía y no se les ofreció NST; debido a una elevada proporción entre el tamaño del tumor y de la mama en 45 (60%) mujeres.
Conclusión
La mayoría de las mastectomías se recomendaron en casos con una elevada proporción entre el tamaño del tumor y el de la mama, pero existe una inconsistencia en la utilización de la NST para reducir el tamaño del tumor en pacientes con grandes cánceres ER+ o HER2+. La aplicación de recomendaciones estandarizadas para la NST podría reducir el número de mastectomía recomendadas por los MDT.
This study sought to evaluate recommendations for mastectomy by UK multidisciplinary teams (MDTs). Most mastectomies are performed for large tumour to breast size ratio. However, many potentially eligible patients are not offered neoadjuvant systemic therapy (NST) to downsize tumours and facilitate breast conservation. Application of standardized recommendations for NST, resulting in increased and appropriate use, could reduce the number of mastectomies advised by MDTs.
Mastecomies can be reduced
Pulmonary inflammation and bacterial colonization are central to the pathogenesis of chronic obstructive pulmonary disease (COPD). Defects in macrophage phagocytosis of both bacteria and apoptotic ...cells contribute to the COPD phenotype. Small molecule inhibitors with anti-inflammatory activity against p38 mitogen activated protein kinases (MAPKs), phosphatidyl-inositol-3 kinase (PI3K) and Rho kinase (ROCK) are being investigated as novel therapeutics in COPD. Concerns exist, however, about off-target effects. We investigated the effect of p38 MAPK inhibitors (VX745 and SCIO469), specific inhibitors of PI3K α (NVS-P13K-2), δ (NVS-P13K-3) or γ (NVS-P13K-5) and a ROCK inhibitor PF4950834 on macrophage phagocytosis, early intracellular killing of bacteria and efferocytosis of apoptotic neutrophils. Alveolar macrophages (AM) obtained from broncho-alveolar lavage (BAL) or monocyte-derived macrophages (MDM) from COPD patients (GOLD stage II/III) enrolled from a well characterized clinical cohort (MRC COPD-MAP consortium) or from healthy ex-smoker controls were studied. Both COPD AM and MDM exhibited lower levels of bacterial phagocytosis (using Streptococcus pneumoniae and non-typeable Haemophilus influenzae) and efferocytosis than healthy controls. None of the inhibitors altered bacterial internalization or early intracellular bacterial killing in AM or MDM. Conversely PF4950834, but not other inhibitors, enhanced efferocytosis in COPD AM and MDM. These results suggest none of these inhibitors are likely to exacerbate phagocytosis-related defects in COPD, while confirming ROCK inhibitors can enhance efferocytosis in COPD.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Lower airway bacterial colonisation (LABC) in COPD patients is associated with increased exacerbation frequency and faster lung function decline. Defective macrophage phagocytosis in COPD drives ...inflammation, but how defective macrophage function contributes to exacerbations is not clear. This study investigated the association between macrophage phagocytosis and exacerbation frequency, LABC and clinical parameters.
Monocyte-derived macrophages (MDM) were generated from 92 stable COPD patients, and at the onset of exacerbation in 39 patients. Macrophages were exposed to fluorescently labelled Haemophilus influenzae or Streptococcus pneumoniae for 4 h, then phagocytosis measured by fluorimetry and cytokine release by ELISA. Sputum bacterial colonisation was measured by PCR.
Phagocytosis of H. influenzae was negatively correlated with exacerbation frequency (r = 0.440, p < 0.01), and was significantly reduced in frequent vs. infrequent exacerbators (1.9 × 10
RFU vs. 2.5 × 10
RFU, p < 0.01). There was no correlation for S. pneumoniae. There was no association between phagocytosis of either bacteria with age, lung function, smoking history or treatment with inhaled corticosteroids, or long-acting bronchodilators. Phagocytosis was not altered during an exacerbation, or in the 2 weeks post-exacerbation. In response to phagocytosis, MDM from exacerbating patients showed increased release of CXCL-8 (p < 0.001) and TNFα (p < 0.01) compared to stable state.
Impaired COPD macrophage phagocytosis of H. influenzae, but not S. pneumoniae is associated with exacerbation frequency, resulting in pro-inflammatory macrophages that may contribute to disease progression. Targeting these frequent exacerbators with drugs that improve macrophage phagocytosis may prove beneficial.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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