Moribund shrimp affected by acute hepatopancreatic necrosis disease (AHPND) from farms in northwestern Mexico were sampled for bacteriological and histological analysis. Bacterial isolates were ...molecularly identified as Vibrio parahaemolyticus by the presence of the tlh gene. The tdh-negative, trh-negative, and tlh-positive V. parahaemolyticus strains were further characterized by repetitive extragenic palindromic element-PCR (rep-PCR), and primers AP1, AP2, AP3, and AP and an ems2 IQ2000 detection kit (GeneReach, Taiwan) were used in the diagnostic tests for AHPND. The V. parahaemolyticus strains were used in immersion challenges with shrimp, and farmed and challenged shrimp presented the same clinical and pathological symptoms: lethargy, empty gut, pale and aqueous hepatopancreas, and expanded chromatophores. Using histological analysis and bacterial density count, three stages of AHNPD (initial, acute, and terminal) were identified in the affected shrimp. The pathognomonic lesions indicating severe desquamation of tubular epithelial cells of the hepatopancreas were observed in both challenged and pond-infected shrimp. The results showed that different V. parahaemolyticus strains have different virulences; some of the less virulent strains do not induce 100% mortality, and mortality rates also rise more slowly than they do for the more virulent strains. The virulence of V. parahaemolyticus strains was dose dependent, where the threshold infective density was 10(4) CFU ml(-1); below that density, no mortality was observed. The AP3 primer set had the best sensitivity and specificity. Field and experimental results showed that the V. parahaemolyticus strain that causes AHPND acts as a primary pathogen for shrimp in Mexico compared with the V. parahaemolyticus strains reported to date.
An endocrine-disrupting chemical (EDC) is an exogenous chemical, or mixture of chemicals, that can interfere with any aspect of hormone action. The potential for deleterious effects of EDC must be ...considered relative to the regulation of hormone synthesis, secretion, and actions and the variability in regulation of these events across the life cycle. The developmental age at which EDC exposures occur is a critical consideration in understanding their effects. Because endocrine systems exhibit tissue-, cell-, and receptor-specific actions during the life cycle, EDC can produce complex, mosaic effects. This complexity causes difficulty when a static approach to toxicity through endocrine mechanisms driven by rigid guidelines is used to identify EDC and manage risk to human and wildlife populations. We propose that principles taken from fundamental endocrinology be employed to identify EDC and manage their risk to exposed populations. We emphasize the importance of developmental stage and, in particular, the realization that exposure to a presumptive “safe” dose of chemical may impact a life stage when there is normally no endogenous hormone exposure, thereby underscoring the potential for very low-dose EDC exposures to have potent and irreversible effects. Finally, with regard to the current program designed to detect putative EDC, namely, the Endocrine Disruptor Screening Program, we offer recommendations for strengthening this program through the incorporation of basic endocrine principles to promote further understanding of complex EDC effects, especially due to developmental exposures.
Battery technology is advancing rapidly with new materials and new chemistries; however, materials stability determining battery lifetime and safety issues constitutes the main bottleneck. ...Electrolyte degradation processes triggered by electron transfer reactions taking place at electrode surfaces of rechargeable batteries result in multicomponent solid-electrolyte interphase (SEI) layers, recognized as the most crucial yet less well-understood phenomena impacting battery technology. Electrons flow via tunneling from the bare surface of negative electrodes during initial battery charge causing electrolyte reduction reactions that lead to SEI nucleation, but the mechanisms for further growth beyond tunneling-allowed distances are not known. Our first-principles computational studies demonstrate that radical species are responsible for the electron transfer that allows SEI layer growth once its thickness has evolved beyond the electron tunneling regime. In addition, the composition, structure, and properties of the SEI layer depend on the electrolyte, especially on the extent to which they are able to polymerize after reduction. Here we present a detailed study of polymerization mechanisms and propose mechanistic differences for electrolytes yielding a fast and a slow SEI growth. This new understanding leads to firm guidelines for rational electrolyte design.
The first interim analysis of the phase III, randomized, double-blind, placebo-controlled, multinational TITAN study demonstrated improved overall survival (OS) and radiographic progression-free ...survival (rPFS) with apalutamide added to ongoing androgen deprivation therapy (ADT) in patients with metastatic castration-sensitive prostate cancer. The final analysis confirmed improvement in OS and other long-term outcomes. We evaluated prostate-specific antigen (PSA) kinetics and the association between PSA decline and outcomes in patients with metastatic castration-sensitive prostate cancer from TITAN.
Patients received apalutamide (240 mg/day) or placebo plus ADT (1 : 1). This post hoc exploratory analysis evaluated PSA kinetics and decline in relation to rPFS (22.7 months’ follow-up) and OS, time to PSA progression, and time to castration resistance (44.0 months’ follow-up) in patients with or without confirmed PSA decline using a landmark analysis, the Kaplan–Meier method, and Cox proportional hazards model.
One thousand and fifty-two patients (apalutamide, 525; placebo, 527) were enrolled. Best confirmed PSA declines (≥50% or ≥90% from baseline or to ≤0.2 ng/ml) were achieved at any time during the study in 90%, 73%, and 68% of apalutamide-treated versus 55%, 29%, and 32% of placebo-treated patients, respectively. By 3 months of apalutamide treatment, best deep PSA decline of ≥90% or to ≤0.2 ng/ml occurred in 59% and 51% of apalutamide- and in 13% and 18% of placebo-treated patients, respectively. Achievement of deep PSA decline at landmark 3 months of apalutamide treatment was associated with longer OS hazard ratio (HR) 0.35; 95% confidence interval (CI) 0.25-0.48), rPFS (HR 0.44; 95% CI 0.30-0.65), time to PSA progression (HR 0.31; 95% CI 0.22-0.44), and time to castration resistance (HR 0.38; 95% CI 0.27-0.52) compared with no decline (P < 0.0001 for all). Similar results were observed at landmark 6 and 12 months of apalutamide treatment.
Apalutamide plus ADT demonstrated a robust (rapid, deep, and durable) PSA decline that was associated with improved clinical outcomes, including long-term survival.
•Apalutamide + androgen deprivation therapy (ADT) resulted in a robust prostate-specific antigen (PSA) decline in TITAN.•Rapid, deep, and durable PSA decline with apalutamide + ADT was associated with improved long-term outcomes.•Results confirm the prognostic impact of PSA decline in patients with metastatic castration-sensitive prostate cancer.
Previous research suggests that learning to categorize faces along a new dimension changes the perceptual representation of that dimension, but little is known about how the representation of ...specific face identities changes after such category learning. Here, we trained participants to categorize faces that varied along two morphing dimensions. One dimension was relevant to the categorization task and the other was irrelevant. We used reverse correlation to estimate the internal templates used to identify the two faces at the extremes of the relevant dimension, both before and after training, and at two different levels of the irrelevant dimension. Categorization training changed the internal templates used for face identification, even though identification and categorization tasks impose different demands on the observers. After categorization training, the internal templates became more invariant across changes in the irrelevant dimension. These results suggest that the representation of face identity can be modified by categorization experience.
A nonperturbative Schwinger-Dyson analysis of mass generation is presented for a non-Hermitian PT -symmetric field theory in four dimensions of an axion coupled to a Dirac fermion. The model is ...motivated by phenomenological considerations. The axion has a quartic self-coupling λ and a Yukawa coupling g to the fermion. The Schwinger-Dyson equations are derived for the model with generic couplings. In the non-Hermitian case there is an additional nonperturbative contribution to the scalar mass. In a simplified rainbow analysis the solutions for the SD equations, are given for different regimes of the couplings g and λ.
Abstract
Distributed optical fibre sensors deliver a map of a physical quantity along an optical fibre, providing a unique solution for health monitoring of targeted structures. Considerable ...developments over recent years have pushed conventional distributed sensors towards their ultimate performance, while any significant improvement demands a substantial hardware overhead. Here, a technique is proposed, encoding the interrogating light signal by a single-sequence aperiodic code and spatially resolving the fibre information through a fast post-processing. The code sequence is once forever computed by a specifically developed genetic algorithm, enabling a performance enhancement using an unmodified conventional configuration for the sensor. The proposed approach is experimentally demonstrated in Brillouin and Raman based sensors, both outperforming the state-of-the-art. This methodological breakthrough can be readily implemented in existing instruments by only modifying the software, offering a simple and cost-effective upgrade towards higher performance for distributed fibre sensing.
Solid‐electrolyte interphase (SEI) films with controllable properties are highly desirable for improving battery performance. In this paper, a combined experimental and theoretical approach is used ...to study SEI films formed on hard carbon in Li‐ and Na‐ion batteries. It is shown that a stable SEI layer can be designed by precycling an electrode in a desired Li‐ or Na‐based electrolyte, and that ionic transport can be kinetically controlled. Selective Li‐ and Na‐based SEI membranes are produced using Li‐ or Na‐based electrolytes, respectively. The Na‐based SEI allows easy transport of Li ions, while the Li‐based SEI shuts off Na‐ion transport. Na‐ion storage can be manipulated by tuning the SEI layer with film‐forming electrolyte additives, or by preforming an SEI layer on the electrode surface. The Na specific capacity can be controlled to < 25 mAh g−1; ≈ 1/10 of the normal capacity (250 mAh g−1). Unusual selective/preferential transport of Li ions is demonstrated by preforming an SEI layer on the electrode surface and corroborated with a mixed electrolyte. This work may provide new guidance for preparing good ion‐selective conductors using electrochemical approaches.
Selective Li‐ and Na‐based solid‐electrolyte interphase (SEI) membranes can be designed by precycling an electrode in a desired Li‐ or Na‐based electrolyte. Na‐based SEI membranes allow easy transport of Li ions, while Li‐based SEI membranes shut off Na‐ion transport. Therefore, Na‐ion storage in hard carbon can be controlled by tuning the SEI layer, while Li‐ion intercalation is not affected.
Platinum(II) complexes display versatile chromic behavior as a consequence of their square planar geometry, which enables intra‐ and intermolecular Pt⋅⋅⋅Pt interactions via open axial coordination ...sites. These metallophilic interactions are known to generate metal‐metal‐to‐ligand‐charge transfer (MMLCT) transitions, in addition to the ligand‐to‐ligand charge transfer (LLCT) and metal‐to‐ligand‐charge‐transfer (MLCT) transitions that are already present. The electronic properties of such complexes, and consequently the magnitude and intensity of these transitions, can be modulated by various functional groups as well as environmental factors, affording control over the color and luminescence. The responsive behavior of these complexes makes them attractive candidates for chromic devices with applications in memory, encryption, sensors, and optoelectronics. This Minireview summarizes the mechanisms and reversibility of optical chromism in platinum(II) complexes, with a focus on the recent developments in the literature.
Chromic phenomena offer an expeditious way to gain visual information about changes in a medium upon the application of a stimulus. In this minireview, we survey recent efforts that report chromic platinum complexes using multidentate ligands. In particular, we discuss the effect of solvents (solvatochromism and vapochromism), temperature, mechanical force, pH, electric potential, light, and ions. The most common mechanisms that make chromism feasible are also covered.
Responsive materials prepared using shape‐memory photonic crystals have potential applications in rewritable photonic devices, security features, and optical coatings. By embedding chiral nematic ...cellulose nanocrystals (CNCs) in a polyacrylate matrix, a shape‐memory photonic crystal thermoplastic (CNC‐SMP) allows reversible capture of different colored states is reported. In this system, the temperature is used to program the shape‐memory response, while pressure is used to compress the helical pitch of the CNC chiral nematic organization. By increasing the force applied (≈140–230 N), the structural color can be tuned from red to blue. Then, on‐demand, the CNC‐SMP can recover to its original state by heating it above the glass transition temperature. This cycle can be performed over 15 times without any loss of the shape‐memory behavior or mechanical degradation of the sample. In addition, multicolor readouts can be programmed into the chiral nematic CNC‐SMP by using a patterned substrate to press the sample, while the glass transition temperature of the CNC‐SMP can be tuned over a 90 °C range by altering the monomer composition used to prepare the polyacrylate matrix.
Temperature‐responsive shape‐memory polymers can reversibly capture the different colored states of chiral nematic cellulose nanocrystals. By controlling the pressure applied to the composite, the color can be tuned, while the temperature response can be manipulated by changing the polymer composition. Hot‐pressing the composite on an embossed surface gives patterned photonic films that can be reset on demand.
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