Comparative study of the direct black removal by Fe, Cu, and Fe/Cu nanoparticles

Abstract

In this study, direct black dye removal was investigated using iron nanoparticles (Fe NPs), copper (Cu NPs), and Fe/Cu (Fe/Cu NPs). NPs were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Using a dose of 0.25 g L⁻¹ of Fe, Cu, and Fe/Cu NPs, a degradation efficiency of 13, 26, and 43% respectively was obtained. For the 1.00 g L⁻¹ dose, the efficiency increased to 100, 43, and 100%, respectively. Studies in anoxic and oxic conditions presented degradation rates, respectively, of 100 and 30% for Fe NPs, 90 and 50% for Fe/Cu NPs, and 40% in both reactions for Cu NPs, indicating that the mechanism of dye degradation by NPs is predominantly reducing under the conditions studied. The addition of EDTA decreased the dye removal rate for Fe, Cu, and Fe/Cu NPs at 27, 10, and 35%, respectively. In addition to the degradation, the adsorption phenomena of the by-products formed during the reaction were confirmed by the Fourier transform infrared (FTIR) analysis and verified by the desorption tests. Fe and Fe/Cu NPs showed the highest efficiency in direct black dye reductive degradation and adsorption of by-products, removing 100% of the dye at a dose of 1 g L⁻¹ within 10 min of reaction.

Graphical abstracts

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Management of Lumbar Spondylolysis in Athletes: Role of Imaging

Abstract

Purpose of review

Spondylolysis is a broad term, with advances in imaging enabling more accurate diagnosis of the activity and severity of a lesion. This review discusses the role of different imaging modalities in the diagnosis and management of lumbar spondylolysis in athletes.

Recent Findings

Magnetic resonance imaging (MRI) has diagnostic and practical advantages over other imaging modalities and is particularly useful for detecting early stages of bone stress, including pre-symptomatic screening for active lumbar bone stress injuries. Whilst computed tomography remains the best imaging technique to visualise cortical breaches, specialised MRI sequences offer a viable alternative to detect active bone stress and chronic non-united defects.

Summary

Imaging provides important information for the clinical management of athletes with lumbar spondylolysis. Roles for imaging, in particular MRI, include: (a) proactive screening and early detection, (b) diagnosis of a symptomatic lesion and (c) monitor healing and readiness to return to sport.

Fate of febantel in the aquatic environment—the role of abiotic elimination processes

Abstract

Febantel is widely used anthelmintic drug active against a range of gastrointestinal parasites in animals. Despite the fact that it has been detected in the aquatic environment, there is no information on its environmental fate. Therefore, abiotic elimination processes of febantel in the aquatic environment have been studied. The results of direct and indirect photodegradation experiments showed that febantel was persistent against solar radiation. Kinetics of hydrolytic elimination was pH and temperature dependent with half-lives in the range from 210 min to 99 days. Febantel metabolites, fenbendazole and fenbendazole sulfone, were found as major degradation products using high-resolution mass spectrometry. The proposed hydrolytic degradation pathway consisted of the base catalyzed hydrolysis followed by consecutive oxidative cyclization to the five-membered ring of the benzo-imidazole derivative. Aquatic toxicity of febantel and its hydrolytic mixture were evaluated toward the luminescence bacteria Vibrio fischeri. Investigation of febantel sorption onto river sediments showed that the best agreement was obtained with the linear model (R² > 0.99), while the rate of sorption is the best described with the kinetic model of pseudo-second order. The organic carbon-normalized sorption coefficient, K_OC, ranged from 1490 to 3894 L kg⁻¹ for five sediment samples. The results of this research demonstrate that febantel persist in the natural waters and potentially could travel far from the source.

Nail apparatus melanoma: Experience of 10 years in a single institution

Background: Nail apparatus melanoma (NAM) is rare. The higher mortality reported in the literature, compared with melanoma on other sites is probably due to advanced disease associated with a delay in diagnosis and treatment.

Comparison of noninsulated microneedle and noninvasive fractional radiofrequency devices in an animal model of skin rejuvenation

Background: Radiofrequency (RF) devices based on various delivery systems are clinically effective in treating many dermatologic conditions. However, there are few histologic studies identifying the therapeutic mechanism and its effect.

Sodium thiosulfate injection dissolves calcium hydroxylapatite particles: An animal study

Background and objective: Treatment of certain dermal filler–related serious AEs (e.g., vascular occlusion, granulomatous reactions) may include removal of the injected material. Hyaluronidase can be used to degrade hyaluronic acid fillers; however, no agents have yet been shown to fully dissolve calcium hydroxylapatite (CaHA; Merz North America) filler after placement. Sodium thiosulfate (STS) has been shown to decrease calcium mineral deposits associated with calciphylaxis, calcific uremic arteriolopathy, and kidney stones.

Topical oxymetazoline hydrochloride 1.0% effectively reduces persistent facial erythema of rosacea on day 1

Introduction: Persistent facial erythema is a bothersome, therapeutically challenging feature of rosacea; therapies with clear efficacy at treatment onset are needed. In 2 identically designed, phase 3 pivotal, randomized, multicenter, double-blind, parallel-group, vehicle-controlled, 29-day REVEAL trials, topical oxymetazoline cream 1.0% significantly reduced moderate to severe persistent facial erythema of rosacea. A post hoc analysis of pooled data from both trials assessed erythema reduction on day 1.

Widespread skin necrosis secondary to gemcitabine

Cutaneous side-effects are relatively common in chemotherapy but vary in frequency and severity depending on the medication, dose, duration, pharmacokinetics, and pharmacodynamics. Gemcitabine, a pyrimidine nucleoside analogue, is an oncologic agent used in the treatment of cutaneous T-cell lymphoma (CTCL). Common dermatologic reactions associated with gemcitabine include alopecia, mild skin rash, and mucositis. Rare reports of other cutaneous reactions include lower extremity skin necrosis, lower extremity pseudocellulitis, and scleroderma-like changes.

The antiinflammatory properties of ivermectin and brimonidine in the treatment of papulopustular rosacea

Introduction: The pathophysiology of papulopustular rosacea (PPR) is not fully understood; however, there is increasing evidence that immune and inflammatory responses play an important role in the persistent and perilesional erythema of PPR. Multiple trials have demonstrated the efficacy of ivermectin 1% cream (IVM) and brimonidine 0.33% gel (BR) for treatment of the inflammatory lesions and erythema of PPR, respectively. Two recent studies suggest a promising synergy between IVM and BR in PPR.

Role of activated oligoadenylatesynthetase–ribonuclease L pathways as a novel therapeutic target in psoriasis

Psoriasis (Pso) is predominantly an immune-mediated disease characterized by aberrant epidermal differentiation, surface scale formation, and marked cutaneous inflammation. Immune pathways activated in Pso include amplification of background immune circuits or induction of certain proinflammatory signaling pathways, otherwise latent in normal human skin. These changes include selective induction of antiviral innate immune response genes, differential expression of pathogen associated molecular pattern (PAMP) receptors, cell signaling and cell growth control pathways.

Unveiling the hidden: The eclipsed effect of nondermatophyte infection and mixed-infection onychomycosis

Background: Mixed onychomycosis infections with dermatophytes (DMPs) and nondermatophytes (NDMs) have become more common. While the diagnosis of DMPs onychomycosis is based on mycologic laboratory, that of the NDMs onychomycosis still has several other criteria. Moreover, there had been a few studies about the relationship between fungal feet and nail infection.

Successful vismodegib debulking of a giant basal cell carcinoma of the umbilicus

Introduction: Basal cell carcinoma (BCC) of the umbilicus is an exceptional subtype of BCC with potential slowly progressing deeply invasive and wide growth pattern. Vismodegib is a hedgehog pathway inhibitor indicated for the treatment of large, nonoperable or metastatic BCC.

Secukinumab shows sustained efficacy in difficult-to-treat palmoplantar, nail, and scalp psoriasis: Long-term results from three phase III placebo-controlled randomized trials

Introduction: Psoriasis is a chronic, autoimmune inflammatory condition that can affect different parts of the body including scalp, nails, palms and soles. Psoriasis localized in these areas remains difficult-to-treat, and can result in significant physical and psychosocial disability. Secukinumab, a fully human monoclonal antibody that selectively neutralizes IL-17A, has been shown to have significant efficacy in the treatment of moderate to severe plaque psoriasis and psoriatic arthritis, demonstrating a rapid onset of action and sustained responses up to 5 years with a favorable safety profile.

Venous treatment of lipodermatosclerosis to improve ambulatory function

Introduction: The manifestations of chronic venous insufficiency (CVI), particularly lipodermatosclerosis (LDS) and venous ulcers, can be devastating to patients as it can adversely affect quality of life, and carry significant psychosocial burden.

Treatment patterns among psoriasis patients newly initiated on etanercept or apremilast in a dermatology specialty electronic medical record (EMR) database

Background: Plaque psoriasis (PSO) is a common inflammatory skin disorder that can require chronic treatment. Etanercept (ETN) is a self-injectable biologic indicated to treat moderate-to-severe PSO. Apremilast (APR) is a nonbiologic oral therapy recently approved to treat moderate-to-severe PSO. We sought to examine the real-world treatment patterns of these agents.

The use of silicone gel to enhance skin wound healing by secondary intention following tumor excision on the scalp and extremities: A descriptive study

Secondary intention (SI) healing is advantageous due to shorter surgical time and lower risk of damage to neighboring structures. It is therefore more tolerable in elderly patients with large wounds and is also indicated for lesions at high risk of recurrence as this facilitates closer surveillance. The main disadvantage however is the need for prolonged wound care. Although there is constant effort in adapting materials designed for chronic wounds as an adjunct to SI healing, a recent Cochrane review expounded on the lack of evidence to support any single method.

Systematic review of placebo responses in randomized clinical trials of systemic therapy for atopic dermatitis

Introduction: Atopic dermatitis (AD) is associated with a variable disease severity and symptom burden and intermittent periods of disease remittance, all of which may contribute to increased placebo responses in randomized clinical trials (RCT). However, little is known about the rates and predictors of placebo responses in RCT of systemic therapy in AD.

Stem cell–conditioned media as a potential antiaging technology in skin care

Stem cell conditioned media (SCCM) is gaining increasing interest and is a promising prospect in the field of regenerative medicine. The beneficial effects of stem cell therapy on damaged tissue have shown to be accredited to their ability to secrete trophic factors, rather than their capacity to differentiate into the needed cells. Various studies on stem cell–derived conditioned media from various cell lines, such as adipose-derived stem cells and bone marrow–derived mesenchymal stem cells, have demonstrated tissue repair in various conditions that involved tissue damage.

Silver nanoparticles induce Egr-1–dependent psoriasin expression via the ERK and p38 pathways

Background: Silver nanoparticles (Ag-NPs) have been known to prevent bacterial infection and improve a cutaneous wound healing due to their antimicrobial activity. However, the mechanism of Ag-NPs' antimicrobial activity is poorly understood.

Scabies mimicking pityriasis rosea: Scabies surrepticius

Background: Scabies is a mite infestation caused by Sarcoptes scabiei that is common worldwide. Scabies is diagnosed based on history and exam of the patient, family, and close contacts. Diagnosis is confirmed based on the demonstration of mites, eggs, or mite feces from scrapings of the lesions. The classic presentation of scabies is extreme pruritus and burrows where the mite penetrates the skin and lays eggs. The most common locations of the lesions include the finger webs, flexor surfaces of the wrists, elbows, axillae, buttocks, and genitalia.

Relationship between pruritus and quality of life in patients with atopic dermatitis treated with crisaborole

Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by eczematous lesions and pruritus. Pruritus can lead to exacerbation of disease and reduced quality of life (QoL). Crisaborole ointment is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate AD. Compared with vehicle, use of crisaborole significantly reduced global disease severity and pruritus in 2 large, identically designed phase 3 clinical studies (AD-301: NCT02118766; AD-302: NCT02118792).

White fibrous papulosus of the neck

Introduction: Whıte fibrous papulosus of the neck (WFPON) is a newly defined clinical diagnosis by Shimizu in 1985. It consists of smooth, linear, 2-3 mm papules, independent of the hair follicles on the neck and back. White fibrous papulosus of the neck (WFPON) and pseudoxanthoma elastic-like dermal elastosis (PXE-PDE) are thought to be clinical variants of the same disease. For this reason, some authors have described WFPON, PXE-PDE and other noninflammatory middermal elastosis cases as "fibroelastolytic variants of primary skin aging." These clinical pictures are clinically similar to each other in many ways, but histologically they can be separated by intact elastic fibers and increased amounts of collagen in the midreticulary dermis.

Using intralesional methotrexate to treat recalcitrant cutaneous Crohn’s disease

Introduction: Cutaneous Crohn's disease (CD) is a rare, and not entirely understood, manifestation of CD that has various clinical presentations. Treatment is difficult, as methods detailed in several case reports over the decades demonstrate mixed efficacy in treating cutaneous CD. Few reports have shown promise using intralesional methotrexate. This case report describes a case of recalcitrant cutaneous CD that resolved with intralesional methotrexate.

Removal of refractory organic pollutants in reverse-osmosis concentrated leachate by Microwave–Fenton process

Abstract

A microwave–Fenton technology was applied to dispose of the reverse-osmosis concentrated leachate. Influential factors on the treatment of concentrated leachate with the pure Fenton and microwave-Fenton method were investigated. For the conventional Fenton process, the removal efficiencies of chemical oxygen demand (COD_Cr), UV₂₅₄, and the color number (CN) reached 84%, 87%, and 96%, respectively, with the biodegradability (BOD₅/COD_Cr) increased from 0.13 to 0.51 at an initial pH of 5.0, Fe²⁺ of 0.04 mol/L, a n(H₂O₂)/n(Fe²⁺) ratio of 8 after a reaction time of 3 h. When incorporating the Fenton process with microwave irradiation, a comparative COD_Cr and UV₂₅₄, and the CN removal rate of 75%, 83%, and 95%, and a high BOD₅/COD_Cr of 0.62 were achieved under a microwave power of 390 W and an extremely shortened reaction time of only 8 min. Meanwhile, sludge quantity showed a reduction of 24.7%, decreased from 8.50 g/L to 6.40 g/L after the participation of microwave. In addition, molecular-weight fraction (MWF), UV-visible spectrum (UV-vis), and 3D-EEM spectrum tests demonstrated that the macromolecular and complex organic compounds in the wastewater were significantly decomposed into small molecular matters. Our results found that microwave–Fenton is a promising technology for concentrated leachate treatment, with much shorter reaction time, lower sludge production, and enhanced biodegradability, as well as comparative organic matter removal performance.

Strahlentherapie bei hepatozellulärem Karzinom

Zusammenfassung

Hintergrund

Das hepatozelluläre Karzinom (HCC) war für die Strahlentherapie lange keine typische Behandlungsindikation, da es erst in den letzten 2 Dekaden möglich wurde, nichttumoröses Lebergewebe ausreichend zu schonen. Daher ist eine radioonkologische Behandlung auf den einschlägigen Behandlungspfaden noch nicht abgebildet.

Fragestellung

Ziel dieser Arbeit ist es, die Möglichkeiten und Grenzen der Strahlentherapie für Patienten mit HCC darzustellen.

Material und Methode

Nach einer knappen Einführung in die Besonderheiten der Radiotherapie für intrahepatische Tumoren wird für die einzelnen Situationen dargestellt, welche Rolle eine perkutane oder interstitielle Radiotherapie bei der Behandlung des HCC spielen kann. Dazu wird eine Einordnung in den verbreiteten Behandlungsalgorithmus nach der Barcelona Clinic Liver Cancer(BCLC)-Klassifikation verwendet.

Ergebnisse

Die Radiotherapie wird bei HCC derzeit v. a. als Körperstereotaxie (SBRT [„stereotactic body radiotherapy"]) eingesetzt, darüber hinaus seltener auch als interstitielle Brachy- sowie als Protonentherapie. Nach der BCLC-Klassifikation kommt sie am häufigsten im Stadium C, gefolgt vom Stadium B zum Einsatz. Auch bei Patienten, bei denen eine Lebertransplantation angestrebt wird, stellt die Radiotherapie eine Möglichkeit für die Überbrückung der Wartezeit („bridging") dar. HCC-Tumoren sind als eher radiosensibel einzustufen, weshalb oft dauerhafte Lokalkontrollen erreicht werden können. Die wichtigste Nebenwirkung, die es durch korrekte Indikationsstellung und optimale Technik gezielt zu vermeiden gilt, ist eine strahleninduzierte Leberkrankheit. Kombinationen der Radiotherapie mit anderen lokalen Verfahren sind nach vorliegender Datenlage im Allgemeinen gut möglich.

Schlussfolgerungen

Die Radiotherapie ist noch nicht als Standardtherapie der ersten Wahl anzusehen, kann aber als wirksame Methode für die Behandlung des HCC angesehen werden. Erste prospektive Studien rechtfertigen diese Einschätzung.

Forecasting Dose from Unobserved Times: Case Study of Transient Workers at a Nuclear Power Plant

Abstract

Objectives

To evaluate the likelihood of exceeding the occupational exposure limit (OEL) for annual ionizing radiation doses among transient workers at the Hope Creek Nuclear Generating Station, and to propose a method for forecasting exposures among transient workers in general.

Methods

We obtained personal dosimeter data from the Hope Creek Nuclear Generating Station for the period of January–December 2014, comprising 1955 monthly dose measurements from 498 transient workers. The majority of the transient workers (96%) did not report 12 months of data. The missing months indicate that transient workers may receive ionizing radiation doses at other nuclear power plants throughout the year. We estimated the likelihood of a worker exceeding the Nuclear Regulatory Commission's annual OEL of 5000 mrem. To do so, we had to account both for left-censored data below the limit of detection (27% of all measurements) and make assumptions about doses received during months not employed at the facility. We used a maximum likelihood estimation method for non-detected measurements that accounted for repeated measurements on an individual. To account for missing months of measurements, we considered two extreme scenarios: the best case of workers who receive zero exposures outside of the Hope Creek, and the illustrative worst case of workers who receive multiple exposures at other nuclear power plants with similar exposure scenarios to Hope Creek. We employed a bootstrap procedure to forecast annual personal doses under both scenarios, while imputing non-detected measurements.

Results

None of the workers' reported measurements exceeded the OEL. Bootstrapped annual exposure doses revealed similar patterns, with a very small likelihood of exceeding the OEL, but great potential for variability. Some workers under the best-case scenario may reach Hope Creek's 2000 mrem internal action limit if exposed at the 98th percentile of their projected annual dose. This scenario becomes more likely when assuming that a worker received doses at other nuclear power plants besides Hope Creek throughout the year.

Conclusions

The Hope Creek Nuclear Generating Station appears to be typical of its industry peers in terms of annual ionizing radiation doses, which makes it a good test subject for predicting worker doses received elsewhere. Transient workers may receive doses at more than one nuclear power plant throughout the year, which makes them especially at risk for overexposure. The presence of internal plant monitoring systems and the use of tools such as bootstrapping to predict compliance are therefore important for health protection. An argument can also be made for better tracking of exposures in real time of transient workers across facilities. Our method applies to transient workers in any industry for whom exposure assessment is complicated by gaps in exposure histories and records.

Coastline Kriging: A Bayesian Approach

Abstract

Statistical interpolation of chemical concentrations at new locations is an important step in assessing a worker's exposure level. When measurements are available from coastlines, as is the case in coastal clean-up operations in oil spills, one may need a mechanism to carry out spatial interpolation at new locations along the coast. In this article, we present a simple model for analyzing spatial data that is observed over a coastline. We demonstrate four different models using two different representations of the coast using curves. The four models were demonstrated on simulated data and one of them was also demonstrated on a dataset from the GuLF STUDY (Gulf Long-term Follow-up Study). Our contribution here is to offer practicing hygienists and exposure assessors with a simple and easy method to implement Bayesian hierarchical models for analyzing and interpolating coastal chemical concentrations.

Safety and dose modification for patients receiving niraparib

Ann Oncol 2018; (doi:10.1093/annonc/mdy181)

Homologous overexpression of NpDps2 and NpDps5 increases the tolerance for oxidative stress in the multicellular cyanobacterium Nostoc punctiforme

Abstract

The filamentous cyanobacterium Nostoc punctiforme has several oxidative stress-managing systems, including Dps proteins. Dps proteins belong to the ferritin superfamily and are involved in abiotic stress management in prokaryotes. Previously, we found that one of the five Dps proteins in Nostoc punctiforme, NpDps2, was critical for H₂O₂ tolerance. Stress induced by high light intensities is aggravated in Nostoc punctiforme strains deficient of either NpDps2, or the bacterioferritin-like NpDps5. Here, we have investigated the capacity of NpDps2 and NpDps5 to enhance stress tolerance by homologous overexpression of these two proteins in Nostoc punctiforme. Both overexpression strains were found to tolerate twice as high concentrations of added H₂O₂ as the control strain, indicating that overexpression of either NpDps2 or NpDps5 will enhance the capacity for H₂O₂ tolerance. Under high light intensities the overexpression of the two NpDps did not enhance the tolerance against general light-induced stress. However, overexpression of the heterocyst-specific NpDps5 in all cells of the filament, led to a higher amount of chlorophyll-binding proteins per cell during diazotrophic growth. The OENpDps5 strain also showed an increased tolerance to ammonium-induced oxidative stress. Our results provide information of how Dps proteins may be utilized for engineering of cyanobacteria with enhanced stress tolerance.

Lpp, the Braun lipoprotein, turns 50 – Major achievements and remaining issues

Abstract

The discovery of Escherichia coli Lpp as the first protein with three acyl groups covalently attached to its N-terminal cysteine residue defined a new class of bacterial proteins, the lipoproteins. Lipoproteins are extracytoplasmic, globular proteins that are anchored to a membrane by a lipid moiety. Being anchored to the outer membrane, Lpp, which is also known as the Braun lipoprotein, is small (5.8 kDa) and folds into a trimeric helical structure. It is also the numerically most abundant protein in E. coli. A unique feature of Lpp is that its C-terminal lysine residue is covalently attached to the peptidoglycan, providing the only covalent connection between the outer membrane and the cell wall. Here, we review the knowledge gained on Lpp since its discovery in 1969 until the recent finding that Lpp functions as a major size determinant in the bacterial cell envelope. We also discuss the role played by Lpp in virulence and highlight the major questions that remain to be solved.

Knowledge Gaps and Barriers to Early Peanut Introduction Among Allergists, Pediatricians, and Family Physicians

Publication date: Available online 13 August 2018

Source: The Journal of Allergy and Clinical Immunology: In Practice

Author(s): Elissa M. Abrams, Alexander G. Singer, Lianne Soller, Edmond S. Chan

Patterns of Fish Reproduction at the Interface Between Air and Water

Synopsis

Although fishes by nature are aquatic, many species reproduce in such a way that their embryos are exposed to air either occasionally or constantly during incubation. We examine the ecological context and review specific examples of reproduction by fishes at the air-water interface, including fishes that do and do not breathe air. Four modes of reproduction at the air-water interface are described across 18 teleost Orders, from fresh water, estuaries and sea water. Mode 1, the most common type of reproduction by fishes at the air-water interface, includes 21 Families of mostly marine teleosts that spawn in water onto a substrate surface, on vegetation, or into hollow objects such as shells that will later be continuously or occasionally exposed to air. Although the eggs are emerged into air, many of these species do not emerge into air as adults, and only about half of them breathe air. Mode 2 involves six Families of freshwater fishes setting up and guarding a nest and guarding on the water surface, either with bubbles or in vegetation. Most of these species breathe air. In Mode 3, annual killifishes in at least two Families in seasonally dry habitats bury eggs in mud in temporary pools, then die before the next generation emerges. These species neither guard nests nor breathe air. Mudskippers (Gobiidae) breathe air and use Mode 4, excavating burrows in a soft substrate and then storing air in a subterranean chamber. In a variation of Mode 4, eggs are placed on bubbles within a nesting burrow by swamp eels (Synbranchidae). No fishes from basal taxa are known to place their embryos where they will be exposed to air, although most of these species breathe air as adults. The widespread but still rare, diverse forms of fish reproduction at the air-water interface across a broad taxonomic spectrum suggest repeated independent evolutionary events and strong selection pressure for adult fishes to protect their embryos from hypoxic waters, aquatic predators, pathogens, and UV radiation. Air-breathing by adult fishes appears to be de-coupled from air exposure of developing embryos or aerial emersion of adults during spawning.

Absorption, translocation, and detoxification of Cd in two different castor bean ( Ricinus communis L.) cultivars

Abstract

Cadmium (Cd) is considered to be the most phytotoxic heavy metal pollutant. The selection of castor bean cultivars with Cd tolerance and the exploration of the physiological mechanisms involved in Cd tolerance are critical steps for improving phytoremediation performance. In this study, a hydroponic experiment was used to investigate variations in Cd transportation, chelation, and subcellular distribution in two different castor bean cultivars, namely JX-22 and ZB-9. Both cultivars had high tolerance index scores, indicating that both cultivars were tolerant to Cd. The findings of the present study indicate that Cd is significantly more mobile in JX-22 than in ZB-9 during xylem and phloem transportation, resulting in the accumulation of Cd in the shoots of JX-22 was 7.67 times that in ZB-9. Subcellular distribution assessment verified that more Cd was bound to the biologically detoxified metal fractions than the metal sensitive fractions in JX-22. The contents of the non-protein thiol pool and glutathione in the leaves were higher in JX-22 than ZB-9 when exposed to Cd. These results indicate that JX-22 has a greater ability to accumulate Cd, and well-coordinated physiological changes in JX-22 afford greater Cd tolerance in comparison to ZB-9 under Cd exposure, indicating that JX-22 is suitable for use in the remediation of Cd-contaminated soils.

Understanding as compression

Abstract

What is understanding? My goal in this paper is to lay out a new approach to this question and clarify how that approach deals with certain issues. The claim is that understanding is a matter of compressing information about the understood so that it can be mentally useful. On this account, understanding amounts to having a representational kernel and the ability to use it to generate the information one needs regarding the target phenomenon. I argue that this ambitious new account can accommodate much of the data that has motivated theories of understanding in philosophy of science, and can also be generally applicable in epistemology and daily life as well.