Information display utilizing plasmonic color generation has recently emerged as an alternative paradigm to traditional printing and display technologies. However, many implementations so far have ...either presented static pixels with a single display state or rely on relatively slow switching mechanisms such as chemical transformations or liquid crystal transitions. Here, we demonstrate spatial, spectral, and temporal control of light using dynamic plasmonic pixels that function through the electric-field-induced alignment of plasmonic nanorods in organic suspensions. By tailoring the geometry and composition (Au and Au@Ag) of the nanorods, we illustrate light modulation across a significant portion of the visible and infrared spectrum (600–2400 nm). The fast (∼30 μs), reversible nanorod alignment is manifested as distinct color changes, characterized by shifts of observed chromaticity and luminance. Integration into larger device architectures is showcased by the fabrication of a seven-segment numerical indicator. The control of light on demand achieved in these dynamic plasmonic pixels establishes a favorable platform for engineering high-performance optical devices.
Explosive blast has been extensively used as a tactical weapon in Operation Iraqi Freedom (OIF) and more recently in Operation Enduring Freedom(OEF). The polytraumatic nature of blast injuries is ...evidence of their effectiveness,and brain injury is a frequent and debilitating form of this trauma. In-theater clinical observations of brain-injured casualties have shown that edema, intracranial hemorrhage, and vasospasm are the most salient pathophysiological characteristics of blast injury to the brain. Unfortunately, little is known about exactly how an explosion produces these sequelae as well as others that are less well documented. Consequently, the principal objective of the current report is to present a swine model of explosive blast injury to the brain. This model was developed during Phase I of the DARPA (Defense Advanced Research Projects Agency) PREVENT (Preventing Violent Explosive Neurotrauma) blast research program. A second objective is to present data that illustrate the capabilities of this model to study the proximal biomechanical causes and the resulting pathophysiological, biochemical,neuropathological, and neurological consequences of explosive blast injury to the swine brain. In the concluding section of this article, the advantages and limitations of the model are considered, explosive and air-overpressure models are compared, and the physical properties of an explosion are identified that potentially contributed to the in-theater closed head injuries resulting from explosions of improvised explosive devices (IEDs).
Blast injury to the brain is the predominant cause of neurotrauma in current military conflicts, and its etiology is largely undefined. Using a compression-driven shock tube to simulate blast ...effects, we assessed the physiological, neuropathological, and neurobehavioral consequences of airblast exposure, and also evaluated the effect of a Kevlar protective vest on acute mortality in rats and on the occurrence of traumatic brain injury (TBI) in those that survived. This approach provides survivable blast conditions under which TBI can be studied. Striking neuropathological changes were caused by both 126- and 147-kPa airblast exposures. The Kevlar vest, which encased the thorax and part of the abdomen, greatly reduced airblast mortality, and also ameliorated the widespread fiber degeneration that was prominent in brains of rats not protected by a vest during exposure to a 126-kPa airblast. This finding points to a significant contribution of the systemic effects of airblast to its brain injury pathophysiology. Airblast of this intensity also disrupted neurologic and neurobehavioral performance (e.g., beam walking and spatial navigation acquisition in the Morris water maze). When immediately followed by hemorrhagic hypotension, with MAP maintained at 30 mm Hg, airblast disrupted cardiocompensatory resilience, as reflected by reduced peak shed blood volume, time to peak shed blood volume, and time to death. These findings demonstrate that shock tube-generated airblast can cause TBI in rats, in part through systemic mediation, and that the resulting brain injury significantly impacts acute cardiovascular homeostatic mechanisms as well as neurobehavioral function.
Liquid crystalline elastomers (LCEs) are stimuli‐responsive materials that transduce an input energy into a mechanical response. LCE composites prepared with photothermal agents, such as ...nanoinclusions, are a means to realize wireless, remote, and local control of deformation with light. Amongst photothermal agents, gold nanorods (AuNRs) are highly efficient converters when the irradiation wavelength matches the longitudinal surface plasmon resonance (LSPR) of the AuNRs. However, AuNR aggregation broadens the LSPR which also reduces photothermal efficiency. Here, the surface chemistry of AuNRs is engineered via a well‐controlled two‐step ligand exchange with a monofunctional poly(ethylene glycol) (PEG) thiol that greatly improves the dispersion of AuNRs in LCEs. Accordingly, LCE‐AuNR nanocomposites with very low PEG‐AuNR content (0.01 wt%) prepared by 3D printing are shown to be highly efficient photothermal actuators with rapid response (>60% strain s−1) upon irradiation with near‐infrared (NIR; 808 nm) light. Because of the excellent dispersion of PEG‐AuNR within the LCE, unabsorbed NIR light transmits through the nanocomposites and can actuate a series of samples. Further, the dispersion also allows for the optical deformation of millimeter‐thick 3D printed structures without sacrificing actuation speed. The realization of well‐dispersed nanoinclusions to maximize the stimulus‐response of LCEs can benefit functional implementation in soft robotics or medical devices.
A two‐step process to functionalize gold nanorods (AuNRs) with poly(ethylene glycol) (PEG) thiol results in improved AuNR dispersion in liquid crystalline elastomers (LCEs). Improved dispersion and low PEG‐AuNR loadings in 3D‐printed LCE‐AuNR enable efficient photothermal heating, rapid actuation with contractile strain rates exceeding 60% s−1, and complex photothermal deformation of 1 mm thick 3D‐printed structures.
Blast-induced traumatic brain injury (TBI) is the signature insult in combat casualty care. Survival with neurological damage from otherwise lethal blast exposures has become possible with body armor ...use. We characterized the neuropathologic alterations produced by a single blast exposure in rats using a helium-driven shock tube to generate a nominal exposure of 35 pounds per square inch (PSI) (positive phase duration ∼ 4 msec). Using an IACUC-approved protocol, isoflurane-anesthetized rats were placed in a steel wedge (to shield the body) 7 feet inside the end of the tube. The left side faced the blast wave (with head-only exposure); the wedge apex focused a Mach stem onto the rat's head. The insult produced ∼ 25% mortality (due to impact apnea). Surviving and sham rats were perfusion-fixed at 24 h, 72 h, or 2 weeks post-blast. Neuropathologic evaluations were performed utilizing hematoxylin and eosin, amino cupric silver, and a variety of immunohistochemical stains for amyloid precursor protein (APP), glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba1), ED1, and rat IgG. Multifocal axonal degeneration, as evidenced by staining with amino cupric silver, was present in all blast-exposed rats at all time points. Deep cerebellar and brainstem white matter tracts were most heavily stained with amino cupric silver, with the morphologic staining patterns suggesting a process of diffuse axonal injury. Silver-stained sections revealed mild multifocal neuronal death at 24 h and 72 h. GFAP, ED1, and Iba1 staining were not prominently increased, although small numbers of reactive microglia were seen within areas of neuronal death. Increased blood-brain barrier permeability (as measured by IgG staining) was seen at 24 h and primarily affected the contralateral cortex. Axonal injury was the most prominent feature during the initial 2 weeks following blast exposure, although degeneration of other neuronal processes was also present. Strikingly, silver staining revealed otherwise undetected abnormalities, and therefore represents a recommended outcome measure in future studies of blast TBI.
Whether the prevalence rates of common mental disorders can be compared across countries depends on the cultural validity of the diagnostic measures used.
To investigate the prevalence of Western and ...indigenously defined mental disorders among Vietnamese living in Vietnam and in Australia, comparing the data with an Australian-born sample.
Comparative analysis of three multistage population surveys, including samples drawn from a community living in the Mekong Delta region of Vietnam (n=3039), Vietnamese immigrants residing in New South Wales, Australia (n=1161), and an Australian-born population (n=7961). Western-defined mental disorders were assessed by the Composite International Diagnostic Interview (CIDI) 2.0 and included DSM-IV anxiety, mood and substance use disorders as well as the ICD-10 category of neurasthenia. The Vietnamese surveys also applied the indigenously based Phan Vietnamese Psychiatric Scale (PVPS). Functional impairment and service use were assessed.
The prevalence of CIDI mental disorders for Mekong Delta Vietnamese was 1.8% compared with 6.1% for Australian Vietnamese and 16.7% for Australians. Inclusion of PVPS mental disorders increased the prevalence rates to 8.8% for Mekong Delta Vietnamese and 11.7% for Australian Vietnamese. Concordance was moderate to good between the CIDI and the PVPS for Australian Vietnamese (area under the curve (AUC)=0.77) but low for Mekong Vietnamese (AUC=0.59). PVPS- and CIDI-defined mental disorders were associated with similar levels of functional impairment.
Cultural factors in the expression of mental distress may influence the prevalence rates of mental disorders reported across countries. The findings have implications for assessing mental health needs at an international level.
The concept of human rights has a long history. Its practical origins, as distinct from its theoretical antecedents, are said to be comparatively recent, going back no further than the American and ...French Bills of Rights of the eighteenth century. Even those landmarks are seen as little more than the precursors of the twentieth century starting-point - the Universal Declaration of Human Rights which was adopted by the General Assembly of the United Nations in 1948. In this unique and stimulating book, Richard Bauman investigates the concept of human rights in the Roman world. He argues that on the theoretical side, ideas were developed by thinkers such as Cicero and Seneca and on the pragmatic side, practical applications were rewarded mainly through the law. He presents a comprehensive analysis of human rights in ancient Rome and offers enlightening comparisons between the Roman and twentieth century understanding of human rights.
'It is a study at once exciting and very learned' – Spokesman 'The author of Human Rights in Ancient Rome lays considerable claims to originality. The systematic organization of a "patchwork" picture is the outstanding merit of this study.' – Greece and Rome
After parturition, dairy cows suffer from an intense energy deficit caused by the onset of copious milk secretion and an inadequate increase in voluntary food intake. We previously showed that this ...energy deficit contributes to a decline in plasma leptin. This decline mirrors that of plasma insulin but is reciprocal to the profile of plasma growth hormone (GH), suggesting that both hormones may regulate plasma leptin in periparturient dairy cows. To study the role of insulin, hyperinsulinemic-euglycemic clamps were performed on six dairy cows in late pregnancy (LP, 31 days prepartum) and early lactation (EL, 7 days postpartum). Infusion of insulin (1 microg.kg body wt-1.h-1) caused a progressive rise in the plasma concentration of leptin that reached maximum levels at 24 h during both physiological states. At steady states, the absolute increase in plasma leptin was greater in LP than in EL cows (2.4 vs. 0.4 ng/ml). Insulin infusion increased leptin mRNA in adipose tissue during LP but not during EL. During lactation, mammary epithelial cells expressed leptin mRNA but insulin did not increase milk leptin output. In contrast, a 3-day period of GH administration had no effect on plasma leptin during LP or EL. Therefore, insulin increases plasma leptin in LP by stimulating adipose tissue synthesis but has only marginal effects in EL, when cows are in negative energy balance. Other factors, such as increased response of adipose tissue to beta-adrenergic signals, probably contribute to the reduction of plasma leptin in early lactating dairy cows.
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