Russian Formalism, one of the twentieth century's most important movements in literary criticism, has received far less attention than most of its rivals. Examining Formalism in light of more recent ...developments in literary theory, Peter Steiner here offers the most comprehensive critique of Formalism to date. Steiner studies the work of the Formalists in terms of the major tropes that characterized their thought. He first considers those theorists who viewed a literary work as a mechanism, an organism, or a system. He then turns to those who sought to reduce literature to its most basic element—language—and who consequently replaced poetics with linguistics. Throughout, Steiner elucidates the basic principles of the Formalists and explores their contributions to the study of poetics, literary history, the theory of literary genre, and prosody. Russian Formalism is an authoritative introduction to the movement that was a major precursor of contemporary critical thought.
Disappointment entails the recognition that one did not get the value expected. In contrast, regret entails recognition that an alternative (counterfactual) action would have produced a more valued ...outcome. In humans, the orbitofrontal cortex is active during expressions of regret, and humans with damage to the orbitofrontal cortex do not express regret. In rats and nonhuman primates, both the orbitofrontal cortex and the ventral striatum have been implicated in reward computations. We recorded neural ensembles from orbitofrontal cortex and ventral striatum in rats encountering wait or skip choices for delayed delivery of different flavors using an economic framework. Economically, encountering a high-cost choice after skipping a low-cost choice should induce regret. In these situations, rats looked backwards toward the lost option, cells within orbitofrontal cortex and ventral striatum represented the missed action, rats were more likely to wait for the long delay, and rats rushed through eating the food after that delay.
Nature's highly efficient light-harvesting antennae, such as those found in green sulfur bacteria, consist of supramolecular building blocks that self-assemble into a hierarchy of close-packed ...structures. In an effort to mimic the fundamental processes that govern nature’s efficient systems, it is important to elucidate the role of each level of hierarchy: from molecule, to supramolecular building block, to close-packed building blocks. Here, we study the impact of hierarchical structure. We present a model system that mirrors nature’s complexity: cylinders self-assembled from cyanine-dye molecules. Our work reveals that even though close-packing may alter the cylinders’ soft mesoscopic structure, robust delocalized excitons are retained: Internal order and strong excitation-transfer interactions—prerequisites for efficient energy transport—are both maintained. Our results suggest that the cylindrical geometry strongly favors robust excitons; it presents a rational design that is potentially key to nature’s high efficiency, allowing construction of efficient light-harvesting devices even from soft, supramolecular materials.
The effect of atmospheric environments on the intergranular stress corrosion cracking (IG-SCC) behavior of AA5083-H131 and AA5456-H116 was investigated using fracture mechanics-based testing, ...high-fidelity monitoring of crack growth kinetics, and electrochemical potential measurements. The IG-SCC susceptibility was found to decrease in atmospheric environments as compared to full immersion at −0.8 VSCE. Critically, the decrease in IG-SCC susceptibility was most prevalent for higher levels of sensitization and the more susceptible AA5083-H131 alloy. These results are analyzed in the context of a coupled anodic dissolution and H-embrittlement mechanism, wherein the reduction in IG-SCC susceptibility in the atmospheric environments results from cathodic limitation of the governing IG-SCC mechanism, leading to a decrease in the dissolution at the crack tip, a less aggressive crack chemistry development, and thus lower levels of H production. A close correlation between the open circuit potential of the bulk surface and the crack growth kinetics was observed for environments without a set potential, and correlates well with known potential-dependent IG-SCC observations.
Purpose
Optimal surgical management of perforated diverticulitis of the sigmoid colon has yet to be clearly defined. The purpose of this study was to evaluate efficacy of a “Damage Control Strategy” ...(DCS).
Materials and methods
Patients with perforated diverticulitis of the sigmoid colon complicated by generalized peritonitis (Hinchey III and IV) surgically treated according to a damage control strategy between May 2011 and February 2017 were enrolled in the present multicenter retrospective cohort study. Data were collected at three surgical centers. DCS comprises a two-stage concept:
1
limited resection of the perforated colon segment with oral and aboral blind closure during the emergency procedure and
2
definitive reconstruction at scheduled second laparotomy (anastomosis ∓ loop ileostomy or a Hartmann’s procedure) after 24–48 h.
Results
Fifty-eight patients were included into the analysis W:M 28:30, median age 70.1 years (30–92). Eleven patients (19%) initially presented with fecal peritonitis (Hinchey IV) and 47 patients with purulent peritonitis (Hinchey III). An anastomosis could be created during the second procedure in 48 patients (83%), 14 of those received an additional loop ileostomy. In the remaining ten patients (
n
= 17%), an end colostomy was created at second laparotomy. A fecal diversion was performed in five patients to treat anastomotic complications. Thus, altogether, 29 patients (50%) had stoma at the end of the hospital stay. The postoperative mortality was 9% (
n
= 5), and median postoperative hospital stay was 18.5 days (3–66). At the end of the follow-up, 44 of 53 surviving patients were stoma free (83%).
Conclusion
The use of the
Damage Control
strategy leads to a comparatively low stoma rate in patients suffering from perforated diverticulitis with generalized peritonitis.
This guideline provides evidence-based recommendations on managing benign paroxysmal positional vertigo (BPPV), which is the most common vestibular disorder in adults, with a lifetime prevalence of ...2.4 percent. The guideline targets patients aged 18 years or older with a potential diagnosis of BPPV, evaluated in any setting in which an adult with BPPV would be identified, monitored, or managed. This guideline is intended for all clinicians who are likely to diagnose and manage adults with BPPV.
The primary purposes of this guideline are to improve quality of care and outcomes for BPPV by improving the accurate and efficient diagnosis of BPPV, reducing the inappropriate use of vestibular suppressant medications, decreasing the inappropriate use of ancillary tests such as radiographic imaging and vestibular testing, and to promote the use of effective repositioning maneuvers for treatment. In creating this guideline, the American Academy of Otolaryngology-Head and Neck Surgery Foundation selected a panel representing the fields of audiology, chiropractic medicine, emergency medicine, family medicine, geriatric medicine, internal medicine, neurology, nursing, otolaryngology-head and neck surgery, physical therapy, and physical medicine and rehabilitation.
The panel made strong recommendations that 1) clinicians should diagnose posterior semicircular canal BPPV when vertigo associated with nystagmus is provoked by the Dix-Hallpike maneuver. The panel made recommendations against 1) radiographic imaging, vestibular testing, or both in patients diagnosed with BPPV, unless the diagnosis is uncertain or there are additional symptoms or signs unrelated to BPPV that warrant testing; and 2) routinely treating BPPV with vestibular suppressant medications such as antihistamines or benzodiazepines. The panel made recommendations that 1) if the patient has a history compatible with BPPV and the Dix-Hallpike test is negative, clinicians should perform a supine roll test to assess for lateral semicircular canal BPPV; 2) clinicians should differentiate BPPV from other causes of imbalance, dizziness, and vertigo; 3) clinicians should question patients with BPPV for factors that modify management including impaired mobility or balance, CNS disorders, lack of home support, and increased risk for falling; 4) clinicians should treat patients with posterior canal BPPV with a particle repositioning maneuver (PRM); 5) clinicians should reassess patients within 1 month after an initial period of observation or treatment to confirm symptom resolution; 6) clinicians should evaluate patients with BPPV who are initial treatment failures for persistent BPPV or underlying peripheral vestibular or CNS disorders; and 7) clinicians should counsel patients regarding the impact of BPPV on their safety, the potential for disease recurrence, and the importance of follow-up. The panel offered as options that 1) clinicians may offer vestibular rehabilitation, either self-administered or with a clinician, for the initial treatment of BPPV and 2) clinicians may offer observation as initial management for patients with BPPV and with assurance of follow-up. The panel made no recommendation concerning audiometric testing in patients diagnosed with BPPV.
This clinical practice guideline is not intended as a sole source of guidance in managing benign paroxysmal positional vertigo. Rather, it is designed to assist clinicians by providing an evidence-based framework for decision-making strategies. The guideline is not intended to replace clinical judgement or establish a protocol for all individuals with this condition, and may not provide the only appropriate approach to diagnosing and managing this problem.
The cause of neurodegeneration in progressive forms of multiple sclerosis is unknown. We investigated the impact of specific neuroinflammatory markers on human neurons to identify potential ...therapeutic targets for neuroprotection against chronic inflammation.
Surface immunocytochemistry directly visualized protease-activated receptor-1 (PAR1) and interleukin-1 (IL-1) receptors on neurons in human postmortem cortex in patients with and without neuroinflammatory lesions. Viability of cultured neurons was determined after exposure to cerebrospinal fluid from patients with progressive multiple sclerosis or purified granzyme B and IL-1β. Inhibitors of PAR1 activation and of PAR1-associated second messenger signaling were used to elucidate a mechanism of neurotoxicity.
Immunohistochemistry of human post-mortem brain tissue demonstrated cells expressing higher amounts of PAR1 near and within subcortical lesions in patients with multiple sclerosis compared to control tissue. Human cerebrospinal fluid samples containing granzyme B and IL-1β were toxic to human neuronal cultures. Granzyme B was neurotoxic through activation of PAR1 and subsequently the phospholipase Cβ-IP3 second messenger system. Inhibition of PAR1 or IP3 prevented granzyme B toxicity. IL-1β enhanced granzyme B-mediated neurotoxicity by increasing PAR1 expression.
Neurons within the inflamed central nervous system are imperiled because they express more PAR1 and are exposed to a neurotoxic combination of both granzyme B and IL-1β. The effects of these inflammatory mediators may be a contributing factor in the progressive brain atrophy associated with neuroinflammatory diseases. Knowledge of how exposure to IL-1β and granzyme B act synergistically to cause neuronal death yields potential novel neuroprotective treatments for neuroinflammatory diseases.
Currently, there is no effective treatment for neurological complications of infection with the human immunodeficiency virus that persists despite the use of combination antiretroviral therapy. A ...medium throughput assay was developed for screening neuroprotective compounds using primary mixed neuronal cells and mitochondrial toxin 3-nitropropionic acid. Using this assay, a library of 2,000 compounds was screened. Out of 256 compounds that showed variable degrees of neuroprotection, nine were related to epicatechin, a monomeric flavonoid found in cocoa and green tea leaves that readily crosses the blood–brain barrier. Hence, catechin, epicatechin, and the related compound, epigallocatechin gallate (EGCG) were further screened for their neuroprotective properties against HIV proteins Tat and gp120, and compared to those of resveratrol. Epicatechin and EGCG targets the brain-derived neurotrophic factor (BDNF) and its precursor proBDNF signaling pathways, normalizing both Tat-mediated increases in proapoptotic proBDNF and concomitant Tat-mediated decreases in the mature BDNF protein in hippocampal neurons. Epicatechin and epigallocatechin gallate were more potent than catechin or resveratrol as neuroprotectants. Due to its simpler structure and more efficient blood–brain barrier penetration properties, epicatechin might be the best therapeutic candidate for neurodegenerative diseases including HIV-associated neurocognitive disorders where oxidative stress is an important pathophysiological mechanism.
Multi-level magnetic recording is a new concept for increasing the data storage capacity of hard disk drives. However, its implementation has been limited by a lack of suitable media capable of ...storing information at multiple levels. Herein, we overcome this problem by developing dual FePt-C nanogranular films separated by a Ru-C breaking layer with a cubic crystal structure. The FePt grains in the bottom and top layers of the developed media exhibited different effective magnetocrystalline anisotropies and Curie temperatures. The former is realized by different degrees of ordering in the L10-FePt grains, whereas the latter was attributed to the diffusion of Ru, thereby enabling separate magnetic recording on each layer under different magnetic fields and temperatures. Furthermore, magnetic measurements and heat-assisted magnetic recording simulations showed that these media enabled 3-level recording and could potentially be extended to 4-level recording, as the ↑↓ and ↓↑ states exhibited non-zero magnetization.
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